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Log the hash used for DH kex (now there's a choice).
[u/mdw/putty] / ssh.c
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374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
374330e2 5
6#include "putty.h"
dacbd0e8 7#include "tree234.h"
fb09bf1c 8#include "ssh.h"
374330e2 9
10#ifndef FALSE
11#define FALSE 0
12#endif
13#ifndef TRUE
14#define TRUE 1
15#endif
16
32874aea 17#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20#define SSH1_CMSG_USER 4 /* 0x4 */
21#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29#define SSH1_SMSG_SUCCESS 14 /* 0xe */
30#define SSH1_SMSG_FAILURE 15 /* 0xf */
31#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34#define SSH1_CMSG_EOF 19 /* 0x13 */
35#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46#define SSH1_MSG_IGNORE 32 /* 0x20 */
47#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50#define SSH1_MSG_DEBUG 36 /* 0x24 */
51#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
58
59#define SSH1_AUTH_TIS 5 /* 0x5 */
60#define SSH1_AUTH_CCARD 16 /* 0x10 */
61
62#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
b96dc54c 63/* Mask for protoflags we will echo back to server if seen */
32874aea 64#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
65
66#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67#define SSH2_MSG_IGNORE 2 /* 0x2 */
68#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69#define SSH2_MSG_DEBUG 4 /* 0x4 */
70#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72#define SSH2_MSG_KEXINIT 20 /* 0x14 */
73#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
761187b6 86#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
32874aea 88#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
102
00db133f 103/*
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
106 */
d1aaf71d 107#define SSH2_PKTCTX_DHGROUP 0x0001
00db133f 108#define SSH2_PKTCTX_DHGEX 0x0002
149d2abc 109#define SSH2_PKTCTX_KEX_MASK 0x000F
00db133f 110#define SSH2_PKTCTX_PUBLICKEY 0x0010
111#define SSH2_PKTCTX_PASSWORD 0x0020
112#define SSH2_PKTCTX_KBDINTER 0x0040
113#define SSH2_PKTCTX_AUTH_MASK 0x00F0
114
32874aea 115#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
38c4a8da 130
131static const char *const ssh2_disconnect_reasons[] = {
132 NULL,
afb4d0dc 133 "host not allowed to connect",
134 "protocol error",
135 "key exchange failed",
136 "host authentication failed",
1da38d29 137 "MAC error",
afb4d0dc 138 "compression error",
139 "service not available",
140 "protocol version not supported",
141 "host key not verifiable",
142 "connection lost",
143 "by application",
144 "too many connections",
145 "auth cancelled by user",
146 "no more auth methods available",
147 "illegal user name",
38c4a8da 148};
9005f3ba 149
32874aea 150#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
d211621f 154
32874aea 155#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 156
7d503c31 157/*
158 * Various remote-bug flags.
159 */
160#define BUG_CHOKES_ON_SSH1_IGNORE 1
161#define BUG_SSH2_HMAC 2
bd358db1 162#define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
0df73905 163#define BUG_CHOKES_ON_RSA 8
1dd353b5 164#define BUG_SSH2_RSA_PADDING 16
088bde77 165#define BUG_SSH2_DERIVEKEY 32
f382c87d 166#define BUG_SSH2_REKEY 64
dda87a28 167#define BUG_SSH2_PK_SESSIONID 128
bd358db1 168
c6ccd5c2 169/*
170 * Codes for terminal modes.
171 * Most of these are the same in SSH-1 and SSH-2.
172 * This list is derived from draft-ietf-secsh-connect-25 and
173 * SSH-1 RFC-1.2.31.
174 */
175static const struct {
176 const char* const mode;
177 int opcode;
178 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
179} ssh_ttymodes[] = {
180 /* "V" prefix discarded for special characters relative to SSH specs */
181 { "INTR", 1, TTY_OP_CHAR },
182 { "QUIT", 2, TTY_OP_CHAR },
183 { "ERASE", 3, TTY_OP_CHAR },
184 { "KILL", 4, TTY_OP_CHAR },
185 { "EOF", 5, TTY_OP_CHAR },
186 { "EOL", 6, TTY_OP_CHAR },
187 { "EOL2", 7, TTY_OP_CHAR },
188 { "START", 8, TTY_OP_CHAR },
189 { "STOP", 9, TTY_OP_CHAR },
190 { "SUSP", 10, TTY_OP_CHAR },
191 { "DSUSP", 11, TTY_OP_CHAR },
192 { "REPRINT", 12, TTY_OP_CHAR },
193 { "WERASE", 13, TTY_OP_CHAR },
194 { "LNEXT", 14, TTY_OP_CHAR },
195 { "FLUSH", 15, TTY_OP_CHAR },
196 { "SWTCH", 16, TTY_OP_CHAR },
197 { "STATUS", 17, TTY_OP_CHAR },
198 { "DISCARD", 18, TTY_OP_CHAR },
199 { "IGNPAR", 30, TTY_OP_BOOL },
200 { "PARMRK", 31, TTY_OP_BOOL },
201 { "INPCK", 32, TTY_OP_BOOL },
202 { "ISTRIP", 33, TTY_OP_BOOL },
203 { "INLCR", 34, TTY_OP_BOOL },
204 { "IGNCR", 35, TTY_OP_BOOL },
205 { "ICRNL", 36, TTY_OP_BOOL },
206 { "IUCLC", 37, TTY_OP_BOOL },
207 { "IXON", 38, TTY_OP_BOOL },
208 { "IXANY", 39, TTY_OP_BOOL },
209 { "IXOFF", 40, TTY_OP_BOOL },
210 { "IMAXBEL", 41, TTY_OP_BOOL },
211 { "ISIG", 50, TTY_OP_BOOL },
212 { "ICANON", 51, TTY_OP_BOOL },
213 { "XCASE", 52, TTY_OP_BOOL },
214 { "ECHO", 53, TTY_OP_BOOL },
215 { "ECHOE", 54, TTY_OP_BOOL },
216 { "ECHOK", 55, TTY_OP_BOOL },
217 { "ECHONL", 56, TTY_OP_BOOL },
218 { "NOFLSH", 57, TTY_OP_BOOL },
219 { "TOSTOP", 58, TTY_OP_BOOL },
220 { "IEXTEN", 59, TTY_OP_BOOL },
221 { "ECHOCTL", 60, TTY_OP_BOOL },
222 { "ECHOKE", 61, TTY_OP_BOOL },
223 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
224 { "OPOST", 70, TTY_OP_BOOL },
225 { "OLCUC", 71, TTY_OP_BOOL },
226 { "ONLCR", 72, TTY_OP_BOOL },
227 { "OCRNL", 73, TTY_OP_BOOL },
228 { "ONOCR", 74, TTY_OP_BOOL },
229 { "ONLRET", 75, TTY_OP_BOOL },
230 { "CS7", 90, TTY_OP_BOOL },
231 { "CS8", 91, TTY_OP_BOOL },
232 { "PARENB", 92, TTY_OP_BOOL },
233 { "PARODD", 93, TTY_OP_BOOL }
234};
235
236/* Miscellaneous other tty-related constants. */
237#define SSH_TTY_OP_END 0
238/* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
239#define SSH1_TTY_OP_ISPEED 192
240#define SSH1_TTY_OP_OSPEED 193
241#define SSH2_TTY_OP_ISPEED 128
242#define SSH2_TTY_OP_OSPEED 129
243
244/* Helper functions for parsing tty-related config. */
245static unsigned int ssh_tty_parse_specchar(char *s)
246{
247 unsigned int ret;
248 if (*s) {
249 char *next = NULL;
250 ret = ctrlparse(s, &next);
251 if (!next) ret = s[0];
252 } else {
253 ret = 255; /* special value meaning "don't set" */
254 }
255 return ret;
256}
257static unsigned int ssh_tty_parse_boolean(char *s)
258{
259 if (stricmp(s, "yes") == 0 ||
260 stricmp(s, "on") == 0 ||
261 stricmp(s, "true") == 0 ||
262 stricmp(s, "+") == 0)
263 return 1; /* true */
264 else if (stricmp(s, "no") == 0 ||
265 stricmp(s, "off") == 0 ||
266 stricmp(s, "false") == 0 ||
267 stricmp(s, "-") == 0)
268 return 0; /* false */
269 else
270 return (atoi(s) != 0);
271}
272
00db133f 273#define translate(x) if (type == x) return #x
51470298 274#define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
ae9ae89f 275static char *ssh1_pkt_type(int type)
00db133f 276{
277 translate(SSH1_MSG_DISCONNECT);
278 translate(SSH1_SMSG_PUBLIC_KEY);
279 translate(SSH1_CMSG_SESSION_KEY);
280 translate(SSH1_CMSG_USER);
281 translate(SSH1_CMSG_AUTH_RSA);
282 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
283 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
284 translate(SSH1_CMSG_AUTH_PASSWORD);
285 translate(SSH1_CMSG_REQUEST_PTY);
286 translate(SSH1_CMSG_WINDOW_SIZE);
287 translate(SSH1_CMSG_EXEC_SHELL);
288 translate(SSH1_CMSG_EXEC_CMD);
289 translate(SSH1_SMSG_SUCCESS);
290 translate(SSH1_SMSG_FAILURE);
291 translate(SSH1_CMSG_STDIN_DATA);
292 translate(SSH1_SMSG_STDOUT_DATA);
293 translate(SSH1_SMSG_STDERR_DATA);
294 translate(SSH1_CMSG_EOF);
295 translate(SSH1_SMSG_EXIT_STATUS);
296 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
297 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
298 translate(SSH1_MSG_CHANNEL_DATA);
299 translate(SSH1_MSG_CHANNEL_CLOSE);
300 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
301 translate(SSH1_SMSG_X11_OPEN);
302 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
303 translate(SSH1_MSG_PORT_OPEN);
304 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
305 translate(SSH1_SMSG_AGENT_OPEN);
306 translate(SSH1_MSG_IGNORE);
307 translate(SSH1_CMSG_EXIT_CONFIRMATION);
308 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
309 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
310 translate(SSH1_MSG_DEBUG);
311 translate(SSH1_CMSG_REQUEST_COMPRESSION);
312 translate(SSH1_CMSG_AUTH_TIS);
313 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
314 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
315 translate(SSH1_CMSG_AUTH_CCARD);
316 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
317 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
318 return "unknown";
319}
ae9ae89f 320static char *ssh2_pkt_type(int pkt_ctx, int type)
00db133f 321{
322 translate(SSH2_MSG_DISCONNECT);
323 translate(SSH2_MSG_IGNORE);
324 translate(SSH2_MSG_UNIMPLEMENTED);
325 translate(SSH2_MSG_DEBUG);
326 translate(SSH2_MSG_SERVICE_REQUEST);
327 translate(SSH2_MSG_SERVICE_ACCEPT);
328 translate(SSH2_MSG_KEXINIT);
329 translate(SSH2_MSG_NEWKEYS);
d1aaf71d 330 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
331 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
00db133f 332 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
333 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
334 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
335 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
336 translate(SSH2_MSG_USERAUTH_REQUEST);
337 translate(SSH2_MSG_USERAUTH_FAILURE);
338 translate(SSH2_MSG_USERAUTH_SUCCESS);
339 translate(SSH2_MSG_USERAUTH_BANNER);
340 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
341 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
342 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
343 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
344 translate(SSH2_MSG_GLOBAL_REQUEST);
345 translate(SSH2_MSG_REQUEST_SUCCESS);
346 translate(SSH2_MSG_REQUEST_FAILURE);
347 translate(SSH2_MSG_CHANNEL_OPEN);
348 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
349 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
350 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
351 translate(SSH2_MSG_CHANNEL_DATA);
352 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
353 translate(SSH2_MSG_CHANNEL_EOF);
354 translate(SSH2_MSG_CHANNEL_CLOSE);
355 translate(SSH2_MSG_CHANNEL_REQUEST);
356 translate(SSH2_MSG_CHANNEL_SUCCESS);
357 translate(SSH2_MSG_CHANNEL_FAILURE);
358 return "unknown";
359}
360#undef translate
361#undef translatec
7d503c31 362
9a10ecf4 363/* Enumeration values for fields in SSH-1 packets */
364enum {
365 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
366 /* These values are for communicating relevant semantics of
367 * fields to the packet logging code. */
368 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
369};
972a41c8 370
acddebd9 371/*
372 * Coroutine mechanics for the sillier bits of the code. If these
373 * macros look impenetrable to you, you might find it helpful to
374 * read
375 *
376 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
377 *
378 * which explains the theory behind these macros.
b624d1e6 379 *
380 * In particular, if you are getting `case expression not constant'
381 * errors when building with MS Visual Studio, this is because MS's
382 * Edit and Continue debugging feature causes their compiler to
383 * violate ANSI C. To disable Edit and Continue debugging:
384 *
385 * - right-click ssh.c in the FileView
386 * - click Settings
387 * - select the C/C++ tab and the General category
388 * - under `Debug info:', select anything _other_ than `Program
389 * Database for Edit and Continue'.
acddebd9 390 */
51470298 391#define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
392#define crState(t) \
393 struct t *s; \
3d88e64d 394 if (!ssh->t) ssh->t = snew(struct t); \
51470298 395 s = ssh->t;
396#define crFinish(z) } *crLine = 0; return (z); }
397#define crFinishV } *crLine = 0; return; }
374330e2 398#define crReturn(z) \
399 do {\
51470298 400 *crLine =__LINE__; return (z); case __LINE__:;\
374330e2 401 } while (0)
402#define crReturnV \
403 do {\
51470298 404 *crLine=__LINE__; return; case __LINE__:;\
374330e2 405 } while (0)
51470298 406#define crStop(z) do{ *crLine = 0; return (z); }while(0)
407#define crStopV do{ *crLine = 0; return; }while(0)
fb09bf1c 408#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 409#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 410
51470298 411typedef struct ssh_tag *Ssh;
ff3187f6 412struct Packet;
413
dacd8872 414static struct Packet *ssh1_pkt_init(int pkt_type);
ff3187f6 415static struct Packet *ssh2_pkt_init(int pkt_type);
dacd8872 416static void ssh_pkt_ensure(struct Packet *, int length);
417static void ssh_pkt_adddata(struct Packet *, void *data, int len);
418static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
ff3187f6 419static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
dacd8872 420static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
421static void ssh_pkt_addstring_start(struct Packet *);
422static void ssh_pkt_addstring_str(struct Packet *, char *data);
423static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
424static void ssh_pkt_addstring(struct Packet *, char *data);
d8baa528 425static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
dacd8872 426static void ssh1_pkt_addmp(struct Packet *, Bignum b);
ff3187f6 427static void ssh2_pkt_addmp(struct Packet *, Bignum b);
428static int ssh2_pkt_construct(Ssh, struct Packet *);
429static void ssh2_pkt_send(Ssh, struct Packet *);
590f6a5f 430static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
ff3187f6 431static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
432 struct Packet *pktin);
433static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
434 struct Packet *pktin);
3d63ca2e 435
5471d09a 436/*
437 * Buffer management constants. There are several of these for
438 * various different purposes:
439 *
440 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
441 * on a local data stream before we throttle the whole SSH
2e85c969 442 * connection (in SSH-1 only). Throttling the whole connection is
5471d09a 443 * pretty drastic so we set this high in the hope it won't
444 * happen very often.
445 *
446 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
447 * on the SSH connection itself before we defensively throttle
448 * _all_ local data streams. This is pretty drastic too (though
2e85c969 449 * thankfully unlikely in SSH-2 since the window mechanism should
5471d09a 450 * ensure that the server never has any need to throttle its end
451 * of the connection), so we set this high as well.
452 *
2e85c969 453 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
5471d09a 454 * channels.
455 */
456
457#define SSH1_BUFFER_LIMIT 32768
458#define SSH_MAX_BACKLOG 32768
459#define OUR_V2_WINSIZE 16384
954d5c5a 460#define OUR_V2_MAXPKT 0x4000UL
d74d141c 461
edd0cb8a 462/* Maximum length of passwords/passphrases (arbitrary) */
463#define SSH_MAX_PASSWORD_LEN 100
464
85cc02bb 465const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
e5574168 466
8b2715b2 467const static struct ssh_mac *macs[] = {
6668a75e 468 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
32874aea 469};
8b2715b2 470const static struct ssh_mac *buggymacs[] = {
6668a75e 471 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
32874aea 472};
e5574168 473
5366aed8 474static void *ssh_comp_none_init(void)
475{
476 return NULL;
477}
478static void ssh_comp_none_cleanup(void *handle)
32874aea 479{
480}
5366aed8 481static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
32874aea 482 unsigned char **outblock, int *outlen)
483{
484 return 0;
485}
5366aed8 486static int ssh_comp_none_disable(void *handle)
32874aea 487{
4ba9b64b 488 return 0;
489}
57476f6b 490const static struct ssh_compress ssh_comp_none = {
4ba9b64b 491 "none",
5366aed8 492 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
493 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
494 ssh_comp_none_disable, NULL
e5574168 495};
4ba9b64b 496extern const struct ssh_compress ssh_zlib;
497const static struct ssh_compress *compressions[] = {
32874aea 498 &ssh_zlib, &ssh_comp_none
499};
374330e2 500
32874aea 501enum { /* channel types */
783415f8 502 CHAN_MAINSESSION,
503 CHAN_X11,
504 CHAN_AGENT,
bc240b21 505 CHAN_SOCKDATA,
506 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
783415f8 507};
508
dacbd0e8 509/*
510 * 2-3-4 tree storing channels.
511 */
512struct ssh_channel {
51470298 513 Ssh ssh; /* pointer back to main context */
d211621f 514 unsigned remoteid, localid;
dacbd0e8 515 int type;
64d6ff88 516 /* True if we opened this channel but server hasn't confirmed. */
517 int halfopen;
0357890f 518 /*
2e85c969 519 * In SSH-1, this value contains four bits:
0357890f 520 *
521 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
522 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
523 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
524 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
525 *
526 * A channel is completely finished with when all four bits are set.
527 */
dacbd0e8 528 int closes;
5471d09a 529 union {
530 struct ssh1_data_channel {
531 int throttling;
532 } v1;
533 struct ssh2_data_channel {
534 bufchain outbuffer;
535 unsigned remwindow, remmaxpkt;
536 unsigned locwindow;
537 } v2;
538 } v;
dacbd0e8 539 union {
32874aea 540 struct ssh_agent_channel {
541 unsigned char *message;
542 unsigned char msglen[4];
a03c9f9c 543 unsigned lensofar, totallen;
32874aea 544 } a;
545 struct ssh_x11_channel {
546 Socket s;
547 } x11;
d74d141c 548 struct ssh_pfd_channel {
549 Socket s;
550 } pfd;
dacbd0e8 551 } u;
552};
57476f6b 553
d74d141c 554/*
2e85c969 555 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
556 * use this structure in different ways, reflecting SSH-2's
bc240b21 557 * altogether saner approach to port forwarding.
558 *
2e85c969 559 * In SSH-1, you arrange a remote forwarding by sending the server
bc240b21 560 * the remote port number, and the local destination host:port.
561 * When a connection comes in, the server sends you back that
562 * host:port pair, and you connect to it. This is a ready-made
563 * security hole if you're not on the ball: a malicious server
564 * could send you back _any_ host:port pair, so if you trustingly
565 * connect to the address it gives you then you've just opened the
566 * entire inside of your corporate network just by connecting
567 * through it to a dodgy SSH server. Hence, we must store a list of
568 * host:port pairs we _are_ trying to forward to, and reject a
569 * connection request from the server if it's not in the list.
570 *
2e85c969 571 * In SSH-2, each side of the connection minds its own business and
bc240b21 572 * doesn't send unnecessary information to the other. You arrange a
573 * remote forwarding by sending the server just the remote port
574 * number. When a connection comes in, the server tells you which
575 * of its ports was connected to; and _you_ have to remember what
576 * local host:port pair went with that port number.
577 *
2e85c969 578 * Hence, in SSH-1 this structure is indexed by destination
579 * host:port pair, whereas in SSH-2 it is indexed by source port.
d74d141c 580 */
fda2feb1 581struct ssh_portfwd; /* forward declaration */
582
d74d141c 583struct ssh_rportfwd {
bc240b21 584 unsigned sport, dport;
585 char dhost[256];
06fadff5 586 char *sportdesc;
fda2feb1 587 struct ssh_portfwd *pfrec;
d74d141c 588};
fda2feb1 589#define free_rportfwd(pf) ( \
590 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
591
592/*
593 * Separately to the rportfwd tree (which is for looking up port
594 * open requests from the server), a tree of _these_ structures is
595 * used to keep track of all the currently open port forwardings,
596 * so that we can reconfigure in mid-session if the user requests
597 * it.
598 */
599struct ssh_portfwd {
84328ddb 600 enum { DESTROY, KEEP, CREATE } status;
fda2feb1 601 int type;
602 unsigned sport, dport;
603 char *saddr, *daddr;
3fe92132 604 char *sserv, *dserv;
fda2feb1 605 struct ssh_rportfwd *remote;
05581745 606 int addressfamily;
fda2feb1 607 void *local;
608};
609#define free_portfwd(pf) ( \
3fe92132 610 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
611 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
d74d141c 612
57476f6b 613struct Packet {
dacd8872 614 long length; /* length of `data' actually used */
615 long forcepad; /* SSH-2: force padding to at least this length */
616 int type; /* only used for incoming packets */
617 unsigned long sequence; /* SSH-2 incoming sequence number */
618 unsigned char *data; /* allocated storage */
619 unsigned char *body; /* offset of payload within `data' */
620 long savedpos; /* temporary index into `data' (for strings) */
621 long maxlen; /* amount of storage allocated for `data' */
622 long encrypted_len; /* for SSH-2 total-size counting */
ff3187f6 623
624 /*
625 * State associated with packet logging
626 */
627 int logmode;
628 int nblanks;
629 struct logblank_t *blanks;
57476f6b 630};
631
1c1a7262 632static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 633 struct Packet *pktin);
1c1a7262 634static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 635 struct Packet *pktin);
b09eaa88 636static void ssh1_protocol_setup(Ssh ssh);
637static void ssh2_protocol_setup(Ssh ssh);
51470298 638static void ssh_size(void *handle, int width, int height);
639static void ssh_special(void *handle, Telnet_Special);
5471d09a 640static int ssh2_try_send(struct ssh_channel *c);
51470298 641static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
642static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
5471d09a 643static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
51470298 644static int ssh_sendbuffer(void *handle);
ac934965 645static int ssh_do_close(Ssh ssh, int notify_exit);
ff3187f6 646static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
647static int ssh2_pkt_getbool(struct Packet *pkt);
648static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
9442dd57 649static void ssh2_timer(void *ctx, long now);
1c1a7262 650static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
9442dd57 651 struct Packet *pktin);
57476f6b 652
51470298 653struct rdpkt1_state_tag {
57476f6b 654 long len, pad, biglen, to_read;
655 unsigned long realcrc, gotcrc;
656 unsigned char *p;
657 int i;
658 int chunk;
ff3187f6 659 struct Packet *pktin;
51470298 660};
57476f6b 661
51470298 662struct rdpkt2_state_tag {
960e736a 663 long len, pad, payload, packetlen, maclen;
664 int i;
665 int cipherblk;
666 unsigned long incoming_sequence;
ff3187f6 667 struct Packet *pktin;
51470298 668};
669
b09eaa88 670typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
06fadff5 671typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
672
673struct queued_handler;
674struct queued_handler {
675 int msg1, msg2;
676 chandler_fn_t handler;
677 void *ctx;
678 struct queued_handler *next;
679};
b09eaa88 680
51470298 681struct ssh_tag {
682 const struct plug_function_table *fn;
683 /* the above field _must_ be first in the structure */
684
4320baf7 685 char *v_c, *v_s;
b672f405 686 void *exhash;
51470298 687
688 Socket s;
689
b9d7bcad 690 void *ldisc;
a8327734 691 void *logctx;
b9d7bcad 692
51470298 693 unsigned char session_key[32];
694 int v1_compressing;
695 int v1_remote_protoflags;
696 int v1_local_protoflags;
697 int agentfwd_enabled;
698 int X11_fwd_enabled;
699 int remote_bugs;
700 const struct ssh_cipher *cipher;
371e569c 701 void *v1_cipher_ctx;
0183b242 702 void *crcda_ctx;
51470298 703 const struct ssh2_cipher *cscipher, *sccipher;
371e569c 704 void *cs_cipher_ctx, *sc_cipher_ctx;
51470298 705 const struct ssh_mac *csmac, *scmac;
e0e1a00d 706 void *cs_mac_ctx, *sc_mac_ctx;
51470298 707 const struct ssh_compress *cscomp, *sccomp;
5366aed8 708 void *cs_comp_ctx, *sc_comp_ctx;
51470298 709 const struct ssh_kex *kex;
710 const struct ssh_signkey *hostkey;
2ccb2fc8 711 unsigned char v2_session_id[32];
b672f405 712 int v2_session_id_len;
27cd7fc2 713 void *kex_ctx;
51470298 714
715 char *savedhost;
716 int savedport;
717 int send_ok;
718 int echoing, editing;
719
720 void *frontend;
721
db219738 722 int ospeed, ispeed; /* temporaries */
51470298 723 int term_width, term_height;
724
725 tree234 *channels; /* indexed by local id */
726 struct ssh_channel *mainchan; /* primary session channel */
727 int exitcode;
ac934965 728 int close_expected;
9e296bfa 729 int clean_exit;
51470298 730
fda2feb1 731 tree234 *rportfwds, *portfwds;
51470298 732
733 enum {
734 SSH_STATE_PREPACKET,
735 SSH_STATE_BEFORE_SIZE,
736 SSH_STATE_INTERMED,
737 SSH_STATE_SESSION,
738 SSH_STATE_CLOSED
739 } state;
740
741 int size_needed, eof_needed;
742
590f6a5f 743 struct Packet **queue;
744 int queuelen, queuesize;
745 int queueing;
51470298 746 unsigned char *deferred_send_data;
747 int deferred_len, deferred_size;
748
749 /*
750 * Gross hack: pscp will try to start SFTP but fall back to
751 * scp1 if that fails. This variable is the means by which
752 * scp.c can reach into the SSH code and find out which one it
753 * got.
754 */
755 int fallback_cmd;
756
6bbce591 757 bufchain banner; /* accumulates banners during do_ssh2_authconn */
51470298 758
51470298 759 int pkt_ctx;
760
302121de 761 void *x11auth;
762
51470298 763 int version;
764 int v1_throttle_count;
765 int overall_bufsize;
766 int throttled_all;
767 int v1_stdout_throttling;
a8756193 768 unsigned long v2_outgoing_sequence;
51470298 769
770 int ssh1_rdpkt_crstate;
771 int ssh2_rdpkt_crstate;
772 int do_ssh_init_crstate;
773 int ssh_gotdata_crstate;
51470298 774 int do_ssh1_login_crstate;
b09eaa88 775 int do_ssh1_connection_crstate;
51470298 776 int do_ssh2_transport_crstate;
777 int do_ssh2_authconn_crstate;
778
779 void *do_ssh_init_state;
780 void *do_ssh1_login_state;
781 void *do_ssh2_transport_state;
782 void *do_ssh2_authconn_state;
783
784 struct rdpkt1_state_tag rdpkt1_state;
785 struct rdpkt2_state_tag rdpkt2_state;
786
2e85c969 787 /* SSH-1 and SSH-2 use this for different things, but both use it */
b09eaa88 788 int protocol_initial_phase_done;
789
1c1a7262 790 void (*protocol) (Ssh ssh, void *vin, int inlen,
ff3187f6 791 struct Packet *pkt);
792 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
86916870 793
794 /*
795 * We maintain a full _copy_ of a Config structure here, not
796 * merely a pointer to it. That way, when we're passed a new
797 * one for reconfiguration, we can check the differences and
798 * potentially reconfigure port forwardings etc in mid-session.
799 */
800 Config cfg;
839f10db 801
802 /*
3d9449a1 803 * Used to transfer data back from async callbacks.
839f10db 804 */
805 void *agent_response;
806 int agent_response_len;
3d9449a1 807 int user_response;
808
809 /*
810 * The SSH connection can be set as `frozen', meaning we are
811 * not currently accepting incoming data from the network. This
812 * is slightly more serious than setting the _socket_ as
813 * frozen, because we may already have had data passed to us
814 * from the network which we need to delay processing until
815 * after the freeze is lifted, so we also need a bufchain to
816 * store that data.
817 */
818 int frozen;
819 bufchain queued_incoming_data;
b09eaa88 820
821 /*
822 * Dispatch table for packet types that we may have to deal
823 * with at any time.
824 */
825 handler_fn_t packet_dispatch[256];
39934deb 826
827 /*
06fadff5 828 * Queues of one-off handler functions for success/failure
829 * indications from a request.
830 */
831 struct queued_handler *qhead, *qtail;
832
833 /*
39934deb 834 * This module deals with sending keepalives.
835 */
836 Pinger pinger;
9442dd57 837
838 /*
839 * Track incoming and outgoing data sizes and time, for
840 * size-based rekeys.
841 */
842 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
d57f70af 843 unsigned long max_data_size;
9442dd57 844 int kex_in_progress;
e6c1536e 845 long next_rekey, last_rekey;
e13bba36 846 char *deferred_rekey_reason; /* points to STATIC string; don't free */
51470298 847};
960e736a 848
382908ad 849#define logevent(s) logevent(ssh->frontend, s)
a8327734 850
851/* logevent, only printf-formatted. */
cbe2d68f 852static void logeventf(Ssh ssh, const char *fmt, ...)
a8327734 853{
854 va_list ap;
57356d63 855 char *buf;
a8327734 856
857 va_start(ap, fmt);
57356d63 858 buf = dupvprintf(fmt, ap);
a8327734 859 va_end(ap);
57356d63 860 logevent(buf);
57356d63 861 sfree(buf);
a8327734 862}
863
6b5cf8b4 864#define bombout(msg) \
865 do { \
866 char *text = dupprintf msg; \
ac934965 867 ssh_do_close(ssh, FALSE); \
6b5cf8b4 868 logevent(text); \
869 connection_fatal(ssh->frontend, "%s", text); \
870 sfree(text); \
871 } while (0)
a8327734 872
9a10ecf4 873/* Functions to leave bits out of the SSH packet log file. */
874
ff3187f6 875static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 876{
877 if (ssh->cfg.logomitpass)
ff3187f6 878 pkt->logmode = blanktype;
9a10ecf4 879}
880
ff3187f6 881static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
9a10ecf4 882{
883 if (ssh->cfg.logomitdata)
ff3187f6 884 pkt->logmode = blanktype;
9a10ecf4 885}
886
ff3187f6 887static void end_log_omission(Ssh ssh, struct Packet *pkt)
9a10ecf4 888{
ff3187f6 889 pkt->logmode = PKTLOG_EMIT;
9a10ecf4 890}
891
c6ccd5c2 892/* Helper function for common bits of parsing cfg.ttymodes. */
893static void parse_ttymodes(Ssh ssh, char *modes,
894 void (*do_mode)(void *data, char *mode, char *val),
895 void *data)
896{
897 while (*modes) {
898 char *t = strchr(modes, '\t');
899 char *m = snewn(t-modes+1, char);
900 char *val;
901 strncpy(m, modes, t-modes);
902 m[t-modes] = '\0';
903 if (*(t+1) == 'A')
904 val = get_ttymode(ssh->frontend, m);
905 else
906 val = dupstr(t+2);
907 if (val)
908 do_mode(data, m, val);
909 sfree(m);
910 sfree(val);
911 modes += strlen(modes) + 1;
912 }
913}
914
32874aea 915static int ssh_channelcmp(void *av, void *bv)
916{
917 struct ssh_channel *a = (struct ssh_channel *) av;
918 struct ssh_channel *b = (struct ssh_channel *) bv;
919 if (a->localid < b->localid)
920 return -1;
921 if (a->localid > b->localid)
922 return +1;
dacbd0e8 923 return 0;
924}
32874aea 925static int ssh_channelfind(void *av, void *bv)
926{
927 unsigned *a = (unsigned *) av;
928 struct ssh_channel *b = (struct ssh_channel *) bv;
929 if (*a < b->localid)
930 return -1;
931 if (*a > b->localid)
932 return +1;
dacbd0e8 933 return 0;
934}
935
bc240b21 936static int ssh_rportcmp_ssh1(void *av, void *bv)
d74d141c 937{
938 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
939 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
940 int i;
bc240b21 941 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
d74d141c 942 return i < 0 ? -1 : +1;
bc240b21 943 if (a->dport > b->dport)
944 return +1;
945 if (a->dport < b->dport)
946 return -1;
947 return 0;
948}
949
950static int ssh_rportcmp_ssh2(void *av, void *bv)
951{
952 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
953 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
cdcbdf3b 954
bc240b21 955 if (a->sport > b->sport)
d74d141c 956 return +1;
bc240b21 957 if (a->sport < b->sport)
958 return -1;
d74d141c 959 return 0;
960}
961
fda2feb1 962/*
963 * Special form of strcmp which can cope with NULL inputs. NULL is
964 * defined to sort before even the empty string.
965 */
966static int nullstrcmp(const char *a, const char *b)
967{
968 if (a == NULL && b == NULL)
969 return 0;
970 if (a == NULL)
971 return -1;
972 if (b == NULL)
973 return +1;
974 return strcmp(a, b);
975}
976
977static int ssh_portcmp(void *av, void *bv)
978{
979 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
980 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
981 int i;
982 if (a->type > b->type)
983 return +1;
984 if (a->type < b->type)
985 return -1;
84328ddb 986 if (a->addressfamily > b->addressfamily)
987 return +1;
988 if (a->addressfamily < b->addressfamily)
989 return -1;
fda2feb1 990 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
991 return i < 0 ? -1 : +1;
992 if (a->sport > b->sport)
993 return +1;
994 if (a->sport < b->sport)
995 return -1;
996 if (a->type != 'D') {
997 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
998 return i < 0 ? -1 : +1;
999 if (a->dport > b->dport)
1000 return +1;
1001 if (a->dport < b->dport)
1002 return -1;
1003 }
1004 return 0;
1005}
1006
51470298 1007static int alloc_channel_id(Ssh ssh)
32874aea 1008{
260f3dec 1009 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1010 unsigned low, high, mid;
d2371c81 1011 int tsize;
1012 struct ssh_channel *c;
1013
1014 /*
1015 * First-fit allocation of channel numbers: always pick the
1016 * lowest unused one. To do this, binary-search using the
1017 * counted B-tree to find the largest channel ID which is in a
1018 * contiguous sequence from the beginning. (Precisely
1019 * everything in that sequence must have ID equal to its tree
1020 * index plus CHANNEL_NUMBER_OFFSET.)
1021 */
51470298 1022 tsize = count234(ssh->channels);
d2371c81 1023
32874aea 1024 low = -1;
1025 high = tsize;
d2371c81 1026 while (high - low > 1) {
1027 mid = (high + low) / 2;
51470298 1028 c = index234(ssh->channels, mid);
d2371c81 1029 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1030 low = mid; /* this one is fine */
1031 else
1032 high = mid; /* this one is past it */
1033 }
1034 /*
1035 * Now low points to either -1, or the tree index of the
1036 * largest ID in the initial sequence.
1037 */
1038 {
1039 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
51470298 1040 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
d2371c81 1041 }
1042 return low + 1 + CHANNEL_NUMBER_OFFSET;
1043}
1044
edd0cb8a 1045static void c_write_stderr(int trusted, const char *buf, int len)
1046{
1047 int i;
1048 for (i = 0; i < len; i++)
1049 if (buf[i] != '\r' && (trusted || buf[i] & 0x60))
1050 fputc(buf[i], stderr);
1051}
1052
9fab77dc 1053static void c_write(Ssh ssh, const char *buf, int len)
32874aea 1054{
edd0cb8a 1055 if (flags & FLAG_STDERR)
1056 c_write_stderr(1, buf, len);
1057 else
1058 from_backend(ssh->frontend, 1, buf, len);
3bdaf79d 1059}
1060
9fab77dc 1061static void c_write_untrusted(Ssh ssh, const char *buf, int len)
32874aea 1062{
edd0cb8a 1063 if (flags & FLAG_STDERR)
1064 c_write_stderr(0, buf, len);
1065 else
1066 from_backend_untrusted(ssh->frontend, buf, len);
a209e957 1067}
1068
9fab77dc 1069static void c_write_str(Ssh ssh, const char *buf)
32874aea 1070{
51470298 1071 c_write(ssh, buf, strlen(buf));
1408a877 1072}
1073
ff3187f6 1074static void ssh_free_packet(struct Packet *pkt)
1075{
1076 sfree(pkt->data);
1077 sfree(pkt);
1078}
1079static struct Packet *ssh_new_packet(void)
1080{
1081 struct Packet *pkt = snew(struct Packet);
1082
dacd8872 1083 pkt->body = pkt->data = NULL;
ff3187f6 1084 pkt->maxlen = 0;
1085 pkt->logmode = PKTLOG_EMIT;
1086 pkt->nblanks = 0;
1087 pkt->blanks = NULL;
1088
1089 return pkt;
1090}
1091
fb09bf1c 1092/*
1093 * Collect incoming data in the incoming packet buffer.
e5574168 1094 * Decipher and verify the packet when it is completely read.
1095 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 1096 * Update the *data and *datalen variables.
ff3187f6 1097 * Return a Packet structure when a packet is completed.
fb09bf1c 1098 */
ff3187f6 1099static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
fb09bf1c 1100{
51470298 1101 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
374330e2 1102
51470298 1103 crBegin(ssh->ssh1_rdpkt_crstate);
374330e2 1104
ff3187f6 1105 st->pktin = ssh_new_packet();
1106
1107 st->pktin->type = 0;
1108 st->pktin->length = 0;
374330e2 1109
57476f6b 1110 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 1111 while ((*datalen) == 0)
ff3187f6 1112 crReturn(NULL);
57476f6b 1113 st->len = (st->len << 8) + **data;
fb09bf1c 1114 (*data)++, (*datalen)--;
1115 }
374330e2 1116
57476f6b 1117 st->pad = 8 - (st->len % 8);
1118 st->biglen = st->len + st->pad;
ff3187f6 1119 st->pktin->length = st->len - 5;
fb09bf1c 1120
ae0500e5 1121 if (st->biglen < 0) {
1122 bombout(("Extremely large packet length from server suggests"
1123 " data stream corruption"));
ff3187f6 1124 ssh_free_packet(st->pktin);
1125 crStop(NULL);
ae0500e5 1126 }
1127
ff3187f6 1128 st->pktin->maxlen = st->biglen;
1129 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
374330e2 1130
57476f6b 1131 st->to_read = st->biglen;
ff3187f6 1132 st->p = st->pktin->data;
57476f6b 1133 while (st->to_read > 0) {
32874aea 1134 st->chunk = st->to_read;
fb09bf1c 1135 while ((*datalen) == 0)
ff3187f6 1136 crReturn(NULL);
57476f6b 1137 if (st->chunk > (*datalen))
1138 st->chunk = (*datalen);
1139 memcpy(st->p, *data, st->chunk);
1140 *data += st->chunk;
1141 *datalen -= st->chunk;
1142 st->p += st->chunk;
1143 st->to_read -= st->chunk;
fb09bf1c 1144 }
374330e2 1145
ff3187f6 1146 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
0183b242 1147 st->biglen, NULL)) {
6b5cf8b4 1148 bombout(("Network attack (CRC compensation) detected!"));
ff3187f6 1149 ssh_free_packet(st->pktin);
1150 crStop(NULL);
9a3a93a5 1151 }
1152
51470298 1153 if (ssh->cipher)
ff3187f6 1154 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
374330e2 1155
ff3187f6 1156 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1157 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
57476f6b 1158 if (st->gotcrc != st->realcrc) {
6b5cf8b4 1159 bombout(("Incorrect CRC received on packet"));
ff3187f6 1160 ssh_free_packet(st->pktin);
1161 crStop(NULL);
fb09bf1c 1162 }
572f871e 1163
ff3187f6 1164 st->pktin->body = st->pktin->data + st->pad + 1;
1165 st->pktin->savedpos = 0;
4ba9b64b 1166
51470298 1167 if (ssh->v1_compressing) {
4ba9b64b 1168 unsigned char *decompblk;
1169 int decomplen;
36b8d9bb 1170 if (!zlib_decompress_block(ssh->sc_comp_ctx,
ff3187f6 1171 st->pktin->body - 1, st->pktin->length + 1,
36b8d9bb 1172 &decompblk, &decomplen)) {
1173 bombout(("Zlib decompression encountered invalid data"));
ff3187f6 1174 ssh_free_packet(st->pktin);
1175 crStop(NULL);
36b8d9bb 1176 }
4ba9b64b 1177
ff3187f6 1178 if (st->pktin->maxlen < st->pad + decomplen) {
1179 st->pktin->maxlen = st->pad + decomplen;
1180 st->pktin->data = sresize(st->pktin->data,
1181 st->pktin->maxlen + APIEXTRA,
3d88e64d 1182 unsigned char);
ff3187f6 1183 st->pktin->body = st->pktin->data + st->pad + 1;
4ba9b64b 1184 }
1185
ff3187f6 1186 memcpy(st->pktin->body - 1, decompblk, decomplen);
dcbde236 1187 sfree(decompblk);
ff3187f6 1188 st->pktin->length = decomplen - 1;
4ba9b64b 1189 }
1190
ff3187f6 1191 st->pktin->type = st->pktin->body[-1];
00db133f 1192
9a10ecf4 1193 /*
1194 * Log incoming packet, possibly omitting sensitive fields.
1195 */
1196 if (ssh->logctx) {
1197 int nblanks = 0;
1198 struct logblank_t blank;
1199 if (ssh->cfg.logomitdata) {
1200 int do_blank = FALSE, blank_prefix = 0;
1201 /* "Session data" packets - omit the data field */
ff3187f6 1202 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1203 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
9a10ecf4 1204 do_blank = TRUE; blank_prefix = 0;
ff3187f6 1205 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
9a10ecf4 1206 do_blank = TRUE; blank_prefix = 4;
1207 }
1208 if (do_blank) {
1209 blank.offset = blank_prefix;
ff3187f6 1210 blank.len = st->pktin->length;
9a10ecf4 1211 blank.type = PKTLOG_OMIT;
1212 nblanks = 1;
1213 }
1214 }
a8327734 1215 log_packet(ssh->logctx,
ff3187f6 1216 PKT_INCOMING, st->pktin->type,
1217 ssh1_pkt_type(st->pktin->type),
1218 st->pktin->body, st->pktin->length,
9a10ecf4 1219 nblanks, &blank);
1220 }
00db133f 1221
ff3187f6 1222 crFinish(st->pktin);
fb09bf1c 1223}
1224
ff3187f6 1225static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
e5574168 1226{
51470298 1227 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
e5574168 1228
51470298 1229 crBegin(ssh->ssh2_rdpkt_crstate);
e5574168 1230
ff3187f6 1231 st->pktin = ssh_new_packet();
1232
1233 st->pktin->type = 0;
1234 st->pktin->length = 0;
51470298 1235 if (ssh->sccipher)
1236 st->cipherblk = ssh->sccipher->blksize;
e5574168 1237 else
32874aea 1238 st->cipherblk = 8;
960e736a 1239 if (st->cipherblk < 8)
32874aea 1240 st->cipherblk = 8;
960e736a 1241
ff3187f6 1242 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
e5574168 1243
1244 /*
1245 * Acquire and decrypt the first block of the packet. This will
1246 * contain the length and padding details.
1247 */
32874aea 1248 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 1249 while ((*datalen) == 0)
ff3187f6 1250 crReturn(NULL);
1251 st->pktin->data[st->i] = *(*data)++;
32874aea 1252 (*datalen)--;
e5574168 1253 }
4252c9cc 1254
51470298 1255 if (ssh->sccipher)
371e569c 1256 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1257 st->pktin->data, st->cipherblk);
e5574168 1258
1259 /*
1260 * Now get the length and padding figures.
1261 */
ff3187f6 1262 st->len = GET_32BIT(st->pktin->data);
1263 st->pad = st->pktin->data[4];
e5574168 1264
1265 /*
717dc483 1266 * _Completely_ silly lengths should be stomped on before they
1267 * do us any more damage.
1268 */
cba1e4b5 1269 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1270 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
6b5cf8b4 1271 bombout(("Incoming packet was garbled on decryption"));
ff3187f6 1272 ssh_free_packet(st->pktin);
1273 crStop(NULL);
717dc483 1274 }
1275
1276 /*
e5574168 1277 * This enables us to deduce the payload length.
1278 */
960e736a 1279 st->payload = st->len - st->pad - 1;
e5574168 1280
ff3187f6 1281 st->pktin->length = st->payload + 5;
e5574168 1282
1283 /*
1284 * So now we can work out the total packet length.
1285 */
960e736a 1286 st->packetlen = st->len + 4;
51470298 1287 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
e5574168 1288
1289 /*
ff3187f6 1290 * Allocate memory for the rest of the packet.
e5574168 1291 */
ff3187f6 1292 st->pktin->maxlen = st->packetlen + st->maclen;
1293 st->pktin->data = sresize(st->pktin->data,
1294 st->pktin->maxlen + APIEXTRA,
1295 unsigned char);
e5574168 1296
1297 /*
1298 * Read and decrypt the remainder of the packet.
1299 */
32874aea 1300 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1301 st->i++) {
e5574168 1302 while ((*datalen) == 0)
ff3187f6 1303 crReturn(NULL);
1304 st->pktin->data[st->i] = *(*data)++;
32874aea 1305 (*datalen)--;
e5574168 1306 }
1307 /* Decrypt everything _except_ the MAC. */
51470298 1308 if (ssh->sccipher)
371e569c 1309 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
ff3187f6 1310 st->pktin->data + st->cipherblk,
51470298 1311 st->packetlen - st->cipherblk);
e5574168 1312
9442dd57 1313 st->pktin->encrypted_len = st->packetlen;
1314
e5574168 1315 /*
1316 * Check the MAC.
1317 */
51470298 1318 if (ssh->scmac
ff3187f6 1319 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
51470298 1320 st->incoming_sequence)) {
6b5cf8b4 1321 bombout(("Incorrect MAC received on packet"));
ff3187f6 1322 ssh_free_packet(st->pktin);
1323 crStop(NULL);
8d5de777 1324 }
b09eaa88 1325
1326 st->pktin->sequence = st->incoming_sequence++;
e5574168 1327
4ba9b64b 1328 /*
1329 * Decompress packet payload.
1330 */
1331 {
1332 unsigned char *newpayload;
1333 int newlen;
51470298 1334 if (ssh->sccomp &&
5366aed8 1335 ssh->sccomp->decompress(ssh->sc_comp_ctx,
ff3187f6 1336 st->pktin->data + 5, st->pktin->length - 5,
51470298 1337 &newpayload, &newlen)) {
ff3187f6 1338 if (st->pktin->maxlen < newlen + 5) {
1339 st->pktin->maxlen = newlen + 5;
1340 st->pktin->data = sresize(st->pktin->data,
1341 st->pktin->maxlen + APIEXTRA,
3d88e64d 1342 unsigned char);
4ba9b64b 1343 }
ff3187f6 1344 st->pktin->length = 5 + newlen;
1345 memcpy(st->pktin->data + 5, newpayload, newlen);
dcbde236 1346 sfree(newpayload);
4ba9b64b 1347 }
1348 }
1349
ff3187f6 1350 st->pktin->savedpos = 6;
1351 st->pktin->body = st->pktin->data;
1352 st->pktin->type = st->pktin->data[5];
e5574168 1353
9a10ecf4 1354 /*
1355 * Log incoming packet, possibly omitting sensitive fields.
1356 */
1357 if (ssh->logctx) {
1358 int nblanks = 0;
1359 struct logblank_t blank;
1360 if (ssh->cfg.logomitdata) {
1361 int do_blank = FALSE, blank_prefix = 0;
1362 /* "Session data" packets - omit the data field */
ff3187f6 1363 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
9a10ecf4 1364 do_blank = TRUE; blank_prefix = 4;
ff3187f6 1365 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
9a10ecf4 1366 do_blank = TRUE; blank_prefix = 8;
1367 }
1368 if (do_blank) {
1369 blank.offset = blank_prefix;
ff3187f6 1370 blank.len = (st->pktin->length-6) - blank_prefix;
9a10ecf4 1371 blank.type = PKTLOG_OMIT;
1372 nblanks = 1;
1373 }
1374 }
ff3187f6 1375 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1376 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1377 st->pktin->data+6, st->pktin->length-6,
9a10ecf4 1378 nblanks, &blank);
1379 }
00db133f 1380
ff3187f6 1381 crFinish(st->pktin);
e5574168 1382}
1383
dacd8872 1384static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
32874aea 1385{
dacd8872 1386 int pad, biglen, i, pktoffs;
374330e2 1387 unsigned long crc;
fd7a4aad 1388#ifdef __SC__
1389 /*
1390 * XXX various versions of SC (including 8.8.4) screw up the
1391 * register allocation in this function and use the same register
1392 * (D6) for len and as a temporary, with predictable results. The
1393 * following sledgehammer prevents this.
1394 */
1395 volatile
1396#endif
1397 int len;
374330e2 1398
a8327734 1399 if (ssh->logctx)
dacd8872 1400 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1401 ssh1_pkt_type(pkt->data[12]),
1402 pkt->body, pkt->length - (pkt->body - pkt->data),
ff3187f6 1403 pkt->nblanks, pkt->blanks);
1404 sfree(pkt->blanks); pkt->blanks = NULL;
1405 pkt->nblanks = 0;
00db133f 1406
51470298 1407 if (ssh->v1_compressing) {
4ba9b64b 1408 unsigned char *compblk;
1409 int complen;
5366aed8 1410 zlib_compress_block(ssh->cs_comp_ctx,
dacd8872 1411 pkt->data + 12, pkt->length - 12,
4ba9b64b 1412 &compblk, &complen);
dacd8872 1413 memcpy(pkt->data + 12, compblk, complen);
dcbde236 1414 sfree(compblk);
dacd8872 1415 pkt->length = complen + 12;
4ba9b64b 1416 }
1417
dacd8872 1418 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1419 pkt->length += 4;
1420 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
32874aea 1421 pad = 8 - (len % 8);
dacd8872 1422 pktoffs = 8 - pad;
1423 biglen = len + pad; /* len(padding+type+data+CRC) */
374330e2 1424
dacd8872 1425 for (i = pktoffs; i < 4+8; i++)
1426 pkt->data[i] = random_byte();
1427 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1428 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1429 PUT_32BIT(pkt->data + pktoffs, len);
374330e2 1430
51470298 1431 if (ssh->cipher)
dacd8872 1432 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1433 pkt->data + pktoffs + 4, biglen);
374330e2 1434
dacd8872 1435 if (offset_p) *offset_p = pktoffs;
1436 return biglen + 4; /* len(length+padding+type+data+CRC) */
39065bed 1437}
1438
ff3187f6 1439static void s_wrpkt(Ssh ssh, struct Packet *pkt)
32874aea 1440{
dacd8872 1441 int len, backlog, offset;
1442 len = s_wrpkt_prepare(ssh, pkt, &offset);
1443 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
5471d09a 1444 if (backlog > SSH_MAX_BACKLOG)
51470298 1445 ssh_throttle_all(ssh, 1, backlog);
dacd8872 1446 ssh_free_packet(pkt);
39065bed 1447}
1448
ff3187f6 1449static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
32874aea 1450{
dacd8872 1451 int len, offset;
1452 len = s_wrpkt_prepare(ssh, pkt, &offset);
51470298 1453 if (ssh->deferred_len + len > ssh->deferred_size) {
1454 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1455 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1456 ssh->deferred_size,
1457 unsigned char);
39065bed 1458 }
dacd8872 1459 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1460 pkt->data + offset, len);
51470298 1461 ssh->deferred_len += len;
dacd8872 1462 ssh_free_packet(pkt);
374330e2 1463}
1464
fb09bf1c 1465/*
dacd8872 1466 * Construct a SSH-1 packet with the specified contents.
1467 * (This all-at-once interface used to be the only one, but now SSH-1
1468 * packets can also be constructed incrementally.)
fb09bf1c 1469 */
dacd8872 1470static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
fb09bf1c 1471{
dacd8872 1472 int argtype;
7cca0d81 1473 Bignum bn;
ff3187f6 1474 struct Packet *pkt;
fb09bf1c 1475
dacd8872 1476 pkt = ssh1_pkt_init(pkttype);
fb09bf1c 1477
dacd8872 1478 while ((argtype = va_arg(ap, int)) != PKT_END) {
1479 unsigned char *argp, argchar;
1480 unsigned long argint;
1481 int arglen;
fb09bf1c 1482 switch (argtype) {
9a10ecf4 1483 /* Actual fields in the packet */
fb09bf1c 1484 case PKT_INT:
dacd8872 1485 argint = va_arg(ap, int);
1486 ssh_pkt_adduint32(pkt, argint);
fb09bf1c 1487 break;
1488 case PKT_CHAR:
dacd8872 1489 argchar = (unsigned char) va_arg(ap, int);
1490 ssh_pkt_addbyte(pkt, argchar);
fb09bf1c 1491 break;
1492 case PKT_DATA:
dacd8872 1493 argp = va_arg(ap, unsigned char *);
1494 arglen = va_arg(ap, int);
1495 ssh_pkt_adddata(pkt, argp, arglen);
fb09bf1c 1496 break;
1497 case PKT_STR:
dacd8872 1498 argp = va_arg(ap, unsigned char *);
1499 ssh_pkt_addstring(pkt, argp);
fb09bf1c 1500 break;
7cca0d81 1501 case PKT_BIGNUM:
dacd8872 1502 bn = va_arg(ap, Bignum);
1503 ssh1_pkt_addmp(pkt, bn);
9a10ecf4 1504 break;
1505 /* Tokens for modifications to packet logging */
1506 case PKTT_PASSWORD:
ff3187f6 1507 dont_log_password(ssh, pkt, PKTLOG_BLANK);
9a10ecf4 1508 break;
1509 case PKTT_DATA:
ff3187f6 1510 dont_log_data(ssh, pkt, PKTLOG_OMIT);
7cca0d81 1511 break;
9a10ecf4 1512 case PKTT_OTHER:
ff3187f6 1513 end_log_omission(ssh, pkt);
9a10ecf4 1514 break;
1515 }
fb09bf1c 1516 }
ff3187f6 1517
1518 return pkt;
39065bed 1519}
fb09bf1c 1520
51470298 1521static void send_packet(Ssh ssh, int pkttype, ...)
32874aea 1522{
ff3187f6 1523 struct Packet *pkt;
dacd8872 1524 va_list ap;
1525 va_start(ap, pkttype);
1526 pkt = construct_packet(ssh, pkttype, ap);
1527 va_end(ap);
ff3187f6 1528 s_wrpkt(ssh, pkt);
fb09bf1c 1529}
1530
51470298 1531static void defer_packet(Ssh ssh, int pkttype, ...)
32874aea 1532{
ff3187f6 1533 struct Packet *pkt;
dacd8872 1534 va_list ap;
1535 va_start(ap, pkttype);
1536 pkt = construct_packet(ssh, pkttype, ap);
1537 va_end(ap);
ff3187f6 1538 s_wrpkt_defer(ssh, pkt);
39065bed 1539}
1540
32874aea 1541static int ssh_versioncmp(char *a, char *b)
1542{
9697bfd2 1543 char *ae, *be;
1544 unsigned long av, bv;
1545
43aa02a7 1546 av = strtoul(a, &ae, 10);
1547 bv = strtoul(b, &be, 10);
32874aea 1548 if (av != bv)
1549 return (av < bv ? -1 : +1);
1550 if (*ae == '.')
1551 ae++;
1552 if (*be == '.')
1553 be++;
43aa02a7 1554 av = strtoul(ae, &ae, 10);
1555 bv = strtoul(be, &be, 10);
32874aea 1556 if (av != bv)
1557 return (av < bv ? -1 : +1);
9697bfd2 1558 return 0;
1559}
1560
e5574168 1561/*
a92dd380 1562 * Utility routines for putting an SSH-protocol `string' and
b672f405 1563 * `uint32' into a hash state.
e5574168 1564 */
b672f405 1565static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
32874aea 1566{
e5574168 1567 unsigned char lenblk[4];
e5574168 1568 PUT_32BIT(lenblk, len);
b672f405 1569 h->bytes(s, lenblk, 4);
1570 h->bytes(s, str, len);
e5574168 1571}
1572
b672f405 1573static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
32874aea 1574{
a92dd380 1575 unsigned char intblk[4];
1576 PUT_32BIT(intblk, i);
b672f405 1577 h->bytes(s, intblk, 4);
a92dd380 1578}
1579
7cca0d81 1580/*
dacd8872 1581 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
7cca0d81 1582 */
dacd8872 1583static void ssh_pkt_ensure(struct Packet *pkt, int length)
32874aea 1584{
ff3187f6 1585 if (pkt->maxlen < length) {
dacd8872 1586 unsigned char *body = pkt->body;
3d71de0b 1587 int offset = body ? body - pkt->data : 0;
ff3187f6 1588 pkt->maxlen = length + 256;
1589 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
dacd8872 1590 if (body) pkt->body = pkt->data + offset;
7cca0d81 1591 }
783415f8 1592}
dacd8872 1593static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
32874aea 1594{
ff3187f6 1595 if (pkt->logmode != PKTLOG_EMIT) {
1596 pkt->nblanks++;
1597 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
dacd8872 1598 assert(pkt->body);
1599 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1600 (pkt->body - pkt->data);
ff3187f6 1601 pkt->blanks[pkt->nblanks-1].len = len;
1602 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1603 }
1604 pkt->length += len;
dacd8872 1605 ssh_pkt_ensure(pkt, pkt->length);
ff3187f6 1606 memcpy(pkt->data + pkt->length - len, data, len);
7cca0d81 1607}
dacd8872 1608static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
32874aea 1609{
dacd8872 1610 ssh_pkt_adddata(pkt, &byte, 1);
7cca0d81 1611}
ff3187f6 1612static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
32874aea 1613{
dacd8872 1614 ssh_pkt_adddata(pkt, &value, 1);
7cca0d81 1615}
dacd8872 1616static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
32874aea 1617{
7cca0d81 1618 unsigned char x[4];
1619 PUT_32BIT(x, value);
dacd8872 1620 ssh_pkt_adddata(pkt, x, 4);
7cca0d81 1621}
dacd8872 1622static void ssh_pkt_addstring_start(struct Packet *pkt)
32874aea 1623{
dacd8872 1624 ssh_pkt_adduint32(pkt, 0);
ff3187f6 1625 pkt->savedpos = pkt->length;
7cca0d81 1626}
dacd8872 1627static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
32874aea 1628{
dacd8872 1629 ssh_pkt_adddata(pkt, data, strlen(data));
ff3187f6 1630 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1631}
dacd8872 1632static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
32874aea 1633{
dacd8872 1634 ssh_pkt_adddata(pkt, data, len);
ff3187f6 1635 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
7cca0d81 1636}
dacd8872 1637static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1638{
1639 ssh_pkt_addstring_start(pkt);
1640 ssh_pkt_addstring_str(pkt, data);
1641}
1642static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1643{
dacd8872 1644 int len = ssh1_bignum_length(b);
1645 unsigned char *data = snewn(len, char);
1646 (void) ssh1_write_bignum(data, b);
1647 ssh_pkt_adddata(pkt, data, len);
1648 sfree(data);
7cca0d81 1649}
d8baa528 1650static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
32874aea 1651{
7cca0d81 1652 unsigned char *p;
32874aea 1653 int i, n = (bignum_bitcount(b) + 7) / 8;
3d88e64d 1654 p = snewn(n + 1, unsigned char);
7cca0d81 1655 p[0] = 0;
3709bfe9 1656 for (i = 1; i <= n; i++)
32874aea 1657 p[i] = bignum_byte(b, n - i);
7cca0d81 1658 i = 0;
32874aea 1659 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1660 i++;
1661 memmove(p, p + i, n + 1 - i);
1662 *len = n + 1 - i;
7cca0d81 1663 return p;
1664}
ff3187f6 1665static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
32874aea 1666{
7cca0d81 1667 unsigned char *p;
1668 int len;
1669 p = ssh2_mpint_fmt(b, &len);
dacd8872 1670 ssh_pkt_addstring_start(pkt);
1671 ssh_pkt_addstring_data(pkt, (char *)p, len);
dcbde236 1672 sfree(p);
7cca0d81 1673}
b185170a 1674
dacd8872 1675static struct Packet *ssh1_pkt_init(int pkt_type)
1676{
1677 struct Packet *pkt = ssh_new_packet();
1678 pkt->length = 4 + 8; /* space for length + max padding */
1679 ssh_pkt_addbyte(pkt, pkt_type);
1680 pkt->body = pkt->data + pkt->length;
1681 return pkt;
1682}
1683
1684/* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1685#define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1686#define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1687#define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1688#define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1689#define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1690#define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1691#define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1692#define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1693
1694static struct Packet *ssh2_pkt_init(int pkt_type)
1695{
1696 struct Packet *pkt = ssh_new_packet();
3d71de0b 1697 pkt->length = 5; /* space for packet length + padding length */
dacd8872 1698 pkt->forcepad = 0;
1699 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
3d71de0b 1700 pkt->body = pkt->data + pkt->length; /* after packet type */
dacd8872 1701 return pkt;
1702}
1703
b185170a 1704/*
2e85c969 1705 * Construct an SSH-2 final-form packet: compress it, encrypt it,
b185170a 1706 * put the MAC on it. Final packet, ready to be sent, is stored in
ff3187f6 1707 * pkt->data. Total length is returned.
b185170a 1708 */
ff3187f6 1709static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
32874aea 1710{
7cca0d81 1711 int cipherblk, maclen, padding, i;
7cca0d81 1712
a8327734 1713 if (ssh->logctx)
ff3187f6 1714 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1715 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
dacd8872 1716 pkt->body, pkt->length - (pkt->body - pkt->data),
ff3187f6 1717 pkt->nblanks, pkt->blanks);
1718 sfree(pkt->blanks); pkt->blanks = NULL;
1719 pkt->nblanks = 0;
00db133f 1720
7cca0d81 1721 /*
4ba9b64b 1722 * Compress packet payload.
1723 */
4ba9b64b 1724 {
1725 unsigned char *newpayload;
1726 int newlen;
51470298 1727 if (ssh->cscomp &&
ff3187f6 1728 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1729 pkt->length - 5,
51470298 1730 &newpayload, &newlen)) {
ff3187f6 1731 pkt->length = 5;
1732 ssh2_pkt_adddata(pkt, newpayload, newlen);
dcbde236 1733 sfree(newpayload);
4ba9b64b 1734 }
1735 }
1736
1737 /*
7cca0d81 1738 * Add padding. At least four bytes, and must also bring total
1739 * length (minus MAC) up to a multiple of the block size.
95d2d262 1740 * If pkt->forcepad is set, make sure the packet is at least that size
1741 * after padding.
7cca0d81 1742 */
51470298 1743 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
32874aea 1744 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
7cca0d81 1745 padding = 4;
95d2d262 1746 if (pkt->length + padding < pkt->forcepad)
1747 padding = pkt->forcepad - pkt->length;
32874aea 1748 padding +=
ff3187f6 1749 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
95d2d262 1750 assert(padding <= 255);
51470298 1751 maclen = ssh->csmac ? ssh->csmac->len : 0;
ff3187f6 1752 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1753 pkt->data[4] = padding;
7cca0d81 1754 for (i = 0; i < padding; i++)
ff3187f6 1755 pkt->data[pkt->length + i] = random_byte();
1756 PUT_32BIT(pkt->data, pkt->length + padding - 4);
51470298 1757 if (ssh->csmac)
ff3187f6 1758 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1759 pkt->length + padding,
51470298 1760 ssh->v2_outgoing_sequence);
1761 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1762
1763 if (ssh->cscipher)
371e569c 1764 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
ff3187f6 1765 pkt->data, pkt->length + padding);
51470298 1766
9442dd57 1767 pkt->encrypted_len = pkt->length + padding;
1768
ff3187f6 1769 /* Ready-to-send packet starts at pkt->data. We return length. */
1770 return pkt->length + padding + maclen;
b185170a 1771}
1772
1773/*
590f6a5f 1774 * Routines called from the main SSH code to send packets. There
1775 * are quite a few of these, because we have two separate
1776 * mechanisms for delaying the sending of packets:
1777 *
1778 * - In order to send an IGNORE message and a password message in
1779 * a single fixed-length blob, we require the ability to
1780 * concatenate the encrypted forms of those two packets _into_ a
1781 * single blob and then pass it to our <network.h> transport
1782 * layer in one go. Hence, there's a deferment mechanism which
1783 * works after packet encryption.
1784 *
1785 * - In order to avoid sending any connection-layer messages
1786 * during repeat key exchange, we have to queue up any such
1787 * outgoing messages _before_ they are encrypted (and in
1788 * particular before they're allocated sequence numbers), and
1789 * then send them once we've finished.
1790 *
1791 * I call these mechanisms `defer' and `queue' respectively, so as
1792 * to distinguish them reasonably easily.
1793 *
1794 * The functions send_noqueue() and defer_noqueue() free the packet
1795 * structure they are passed. Every outgoing packet goes through
1796 * precisely one of these functions in its life; packets passed to
1797 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1798 * these or get queued, and then when the queue is later emptied
1799 * the packets are all passed to defer_noqueue().
97ab28d7 1800 *
1801 * When using a CBC-mode cipher, it's necessary to ensure that an
1802 * attacker can't provide data to be encrypted using an IV that they
1803 * know. We ensure this by prefixing each packet that might contain
1804 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1805 * mechanism, so in this case send_noqueue() ends up redirecting to
1806 * defer_noqueue(). If you don't like this inefficiency, don't use
1807 * CBC.
b185170a 1808 */
590f6a5f 1809
97ab28d7 1810static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1811static void ssh_pkt_defersend(Ssh);
1812
590f6a5f 1813/*
2e85c969 1814 * Send an SSH-2 packet immediately, without queuing or deferring.
590f6a5f 1815 */
1816static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
32874aea 1817{
5471d09a 1818 int len;
1819 int backlog;
97ab28d7 1820 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1821 /* We need to send two packets, so use the deferral mechanism. */
1822 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1823 ssh_pkt_defersend(ssh);
1824 return;
1825 }
ff3187f6 1826 len = ssh2_pkt_construct(ssh, pkt);
1827 backlog = sk_write(ssh->s, (char *)pkt->data, len);
5471d09a 1828 if (backlog > SSH_MAX_BACKLOG)
51470298 1829 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1830
1831 ssh->outgoing_data_size += pkt->encrypted_len;
1832 if (!ssh->kex_in_progress &&
d57f70af 1833 ssh->max_data_size != 0 &&
1834 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1835 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1836
ff3187f6 1837 ssh_free_packet(pkt);
b185170a 1838}
1839
1840/*
2e85c969 1841 * Defer an SSH-2 packet.
b185170a 1842 */
97ab28d7 1843static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
32874aea 1844{
97ab28d7 1845 int len;
1846 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1847 ssh->deferred_len == 0 && !noignore) {
1848 /*
1849 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1850 * get encrypted with a known IV.
1851 */
1852 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1853 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1854 }
1855 len = ssh2_pkt_construct(ssh, pkt);
51470298 1856 if (ssh->deferred_len + len > ssh->deferred_size) {
1857 ssh->deferred_size = ssh->deferred_len + len + 128;
3d88e64d 1858 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1859 ssh->deferred_size,
1860 unsigned char);
b185170a 1861 }
ff3187f6 1862 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
51470298 1863 ssh->deferred_len += len;
9442dd57 1864 ssh->deferred_data_size += pkt->encrypted_len;
ff3187f6 1865 ssh_free_packet(pkt);
b185170a 1866}
1867
1868/*
2e85c969 1869 * Queue an SSH-2 packet.
590f6a5f 1870 */
1871static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1872{
1873 assert(ssh->queueing);
1874
1875 if (ssh->queuelen >= ssh->queuesize) {
1876 ssh->queuesize = ssh->queuelen + 32;
1877 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1878 }
1879
1880 ssh->queue[ssh->queuelen++] = pkt;
1881}
1882
1883/*
1884 * Either queue or send a packet, depending on whether queueing is
1885 * set.
1886 */
1887static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1888{
1889 if (ssh->queueing)
1890 ssh2_pkt_queue(ssh, pkt);
1891 else
1892 ssh2_pkt_send_noqueue(ssh, pkt);
1893}
1894
95d2d262 1895#if 0 /* disused */
590f6a5f 1896/*
1897 * Either queue or defer a packet, depending on whether queueing is
1898 * set.
1899 */
1900static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1901{
1902 if (ssh->queueing)
1903 ssh2_pkt_queue(ssh, pkt);
1904 else
97ab28d7 1905 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
590f6a5f 1906}
95d2d262 1907#endif
590f6a5f 1908
1909/*
b185170a 1910 * Send the whole deferred data block constructed by
2e85c969 1911 * ssh2_pkt_defer() or SSH-1's defer_packet().
590f6a5f 1912 *
1913 * The expected use of the defer mechanism is that you call
1914 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1915 * not currently queueing, this simply sets up deferred_send_data
1916 * and then sends it. If we _are_ currently queueing, the calls to
1917 * ssh2_pkt_defer() put the deferred packets on to the queue
1918 * instead, and therefore ssh_pkt_defersend() has no deferred data
1919 * to send. Hence, there's no need to make it conditional on
1920 * ssh->queueing.
b185170a 1921 */
51470298 1922static void ssh_pkt_defersend(Ssh ssh)
32874aea 1923{
5471d09a 1924 int backlog;
d8baa528 1925 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1926 ssh->deferred_len);
51470298 1927 ssh->deferred_len = ssh->deferred_size = 0;
1928 sfree(ssh->deferred_send_data);
1929 ssh->deferred_send_data = NULL;
5471d09a 1930 if (backlog > SSH_MAX_BACKLOG)
51470298 1931 ssh_throttle_all(ssh, 1, backlog);
9442dd57 1932
1933 ssh->outgoing_data_size += ssh->deferred_data_size;
1934 if (!ssh->kex_in_progress &&
d57f70af 1935 ssh->max_data_size != 0 &&
1936 ssh->outgoing_data_size > ssh->max_data_size)
f382c87d 1937 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
9442dd57 1938 ssh->deferred_data_size = 0;
7cca0d81 1939}
1940
590f6a5f 1941/*
2e85c969 1942 * Send all queued SSH-2 packets. We send them by means of
590f6a5f 1943 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1944 * packets that needed to be lumped together.
1945 */
1946static void ssh2_pkt_queuesend(Ssh ssh)
1947{
1948 int i;
1949
1950 assert(!ssh->queueing);
1951
1952 for (i = 0; i < ssh->queuelen; i++)
97ab28d7 1953 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
590f6a5f 1954 ssh->queuelen = 0;
1955
1956 ssh_pkt_defersend(ssh);
1957}
1958
7cca0d81 1959#if 0
32874aea 1960void bndebug(char *string, Bignum b)
1961{
7cca0d81 1962 unsigned char *p;
1963 int i, len;
1964 p = ssh2_mpint_fmt(b, &len);
1965 debug(("%s", string));
1966 for (i = 0; i < len; i++)
32874aea 1967 debug((" %02x", p[i]));
765c4200 1968 debug(("\n"));
dcbde236 1969 sfree(p);
7cca0d81 1970}
1971#endif
1972
b672f405 1973static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
32874aea 1974{
7cca0d81 1975 unsigned char *p;
1976 int len;
1977 p = ssh2_mpint_fmt(b, &len);
b672f405 1978 hash_string(h, s, p, len);
dcbde236 1979 sfree(p);
7cca0d81 1980}
1981
1982/*
2e85c969 1983 * Packet decode functions for both SSH-1 and SSH-2.
7cca0d81 1984 */
ff3187f6 1985static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
32874aea 1986{
7cca0d81 1987 unsigned long value;
ff3187f6 1988 if (pkt->length - pkt->savedpos < 4)
32874aea 1989 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1990 value = GET_32BIT(pkt->body + pkt->savedpos);
1991 pkt->savedpos += 4;
7cca0d81 1992 return value;
1993}
ff3187f6 1994static int ssh2_pkt_getbool(struct Packet *pkt)
32874aea 1995{
65a22376 1996 unsigned long value;
ff3187f6 1997 if (pkt->length - pkt->savedpos < 1)
32874aea 1998 return 0; /* arrgh, no way to decline (FIXME?) */
ff3187f6 1999 value = pkt->body[pkt->savedpos] != 0;
2000 pkt->savedpos++;
65a22376 2001 return value;
2002}
ff3187f6 2003static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
32874aea 2004{
57356d63 2005 int len;
7cca0d81 2006 *p = NULL;
45068b27 2007 *length = 0;
ff3187f6 2008 if (pkt->length - pkt->savedpos < 4)
32874aea 2009 return;
ff3187f6 2010 len = GET_32BIT(pkt->body + pkt->savedpos);
57356d63 2011 if (len < 0)
2012 return;
2013 *length = len;
ff3187f6 2014 pkt->savedpos += 4;
2015 if (pkt->length - pkt->savedpos < *length)
32874aea 2016 return;
ff3187f6 2017 *p = (char *)(pkt->body + pkt->savedpos);
2018 pkt->savedpos += *length;
7cca0d81 2019}
ff3187f6 2020static void *ssh_pkt_getdata(struct Packet *pkt, int length)
0016d70b 2021{
ff3187f6 2022 if (pkt->length - pkt->savedpos < length)
0016d70b 2023 return NULL;
ff3187f6 2024 pkt->savedpos += length;
2025 return pkt->body + (pkt->savedpos - length);
0016d70b 2026}
ff3187f6 2027static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
0016d70b 2028 unsigned char **keystr)
2029{
2030 int j;
2031
ff3187f6 2032 j = makekey(pkt->body + pkt->savedpos,
2033 pkt->length - pkt->savedpos,
0016d70b 2034 key, keystr, 0);
2035
2036 if (j < 0)
2037 return FALSE;
2038
ff3187f6 2039 pkt->savedpos += j;
2040 assert(pkt->savedpos < pkt->length);
0016d70b 2041
2042 return TRUE;
2043}
ff3187f6 2044static Bignum ssh1_pkt_getmp(struct Packet *pkt)
0016d70b 2045{
2046 int j;
2047 Bignum b;
2048
ff3187f6 2049 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2050 pkt->length - pkt->savedpos, &b);
0016d70b 2051
2052 if (j < 0)
2053 return NULL;
2054
ff3187f6 2055 pkt->savedpos += j;
0016d70b 2056 return b;
2057}
ff3187f6 2058static Bignum ssh2_pkt_getmp(struct Packet *pkt)
32874aea 2059{
7cca0d81 2060 char *p;
3709bfe9 2061 int length;
7cca0d81 2062 Bignum b;
2063
ff3187f6 2064 ssh_pkt_getstring(pkt, &p, &length);
7cca0d81 2065 if (!p)
32874aea 2066 return NULL;
ff3187f6 2067 if (p[0] & 0x80)
32874aea 2068 return NULL;
d8baa528 2069 b = bignum_from_bytes((unsigned char *)p, length);
7cca0d81 2070 return b;
2071}
2072
7d503c31 2073/*
2e85c969 2074 * Helper function to add an SSH-2 signature blob to a packet.
1dd353b5 2075 * Expects to be shown the public key blob as well as the signature
2076 * blob. Normally works just like ssh2_pkt_addstring, but will
2077 * fiddle with the signature packet if necessary for
2078 * BUG_SSH2_RSA_PADDING.
2079 */
ff3187f6 2080static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2081 void *pkblob_v, int pkblob_len,
1dd353b5 2082 void *sigblob_v, int sigblob_len)
2083{
2084 unsigned char *pkblob = (unsigned char *)pkblob_v;
2085 unsigned char *sigblob = (unsigned char *)sigblob_v;
2086
2087 /* dmemdump(pkblob, pkblob_len); */
2088 /* dmemdump(sigblob, sigblob_len); */
2089
2090 /*
2091 * See if this is in fact an ssh-rsa signature and a buggy
2092 * server; otherwise we can just do this the easy way.
2093 */
51470298 2094 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1dd353b5 2095 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2096 int pos, len, siglen;
2097
2098 /*
2099 * Find the byte length of the modulus.
2100 */
2101
2102 pos = 4+7; /* skip over "ssh-rsa" */
2103 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2104 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2105 pos += 4; /* find modulus itself */
2106 while (len > 0 && pkblob[pos] == 0)
2107 len--, pos++;
2108 /* debug(("modulus length is %d\n", len)); */
2109
2110 /*
2111 * Now find the signature integer.
2112 */
2113 pos = 4+7; /* skip over "ssh-rsa" */
2114 siglen = GET_32BIT(sigblob+pos);
2115 /* debug(("signature length is %d\n", siglen)); */
2116
2117 if (len != siglen) {
2118 unsigned char newlen[4];
ff3187f6 2119 ssh2_pkt_addstring_start(pkt);
2120 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
1dd353b5 2121 /* dmemdump(sigblob, pos); */
2122 pos += 4; /* point to start of actual sig */
2123 PUT_32BIT(newlen, len);
ff3187f6 2124 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
1dd353b5 2125 /* dmemdump(newlen, 4); */
2126 newlen[0] = 0;
2127 while (len-- > siglen) {
ff3187f6 2128 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
1dd353b5 2129 /* dmemdump(newlen, 1); */
2130 }
ff3187f6 2131 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
1dd353b5 2132 /* dmemdump(sigblob+pos, siglen); */
2133 return;
2134 }
2135
2136 /* Otherwise fall through and do it the easy way. */
2137 }
2138
ff3187f6 2139 ssh2_pkt_addstring_start(pkt);
2140 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
1dd353b5 2141}
2142
2143/*
7d503c31 2144 * Examine the remote side's version string and compare it against
2145 * a list of known buggy implementations.
2146 */
51470298 2147static void ssh_detect_bugs(Ssh ssh, char *vstring)
32874aea 2148{
2149 char *imp; /* pointer to implementation part */
7d503c31 2150 imp = vstring;
2151 imp += strcspn(imp, "-");
bd358db1 2152 if (*imp) imp++;
7d503c31 2153 imp += strcspn(imp, "-");
bd358db1 2154 if (*imp) imp++;
7d503c31 2155
51470298 2156 ssh->remote_bugs = 0;
7d503c31 2157
5ecd7ad0 2158 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2159 (ssh->cfg.sshbug_ignore1 == AUTO &&
2c9c6388 2160 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2161 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
46ac09aa 2162 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
bd0b4caf 2163 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
32874aea 2164 /*
2165 * These versions don't support SSH1_MSG_IGNORE, so we have
2166 * to use a different defence against password length
2167 * sniffing.
2168 */
51470298 2169 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2e85c969 2170 logevent("We believe remote version has SSH-1 ignore bug");
7d503c31 2171 }
2172
5ecd7ad0 2173 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2174 (ssh->cfg.sshbug_plainpw1 == AUTO &&
46ac09aa 2175 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
bd358db1 2176 /*
2177 * These versions need a plain password sent; they can't
2178 * handle having a null and a random length of data after
2179 * the password.
2180 */
51470298 2181 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2e85c969 2182 logevent("We believe remote version needs a plain SSH-1 password");
bd358db1 2183 }
2184
5ecd7ad0 2185 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2186 (ssh->cfg.sshbug_rsa1 == AUTO &&
2c9c6388 2187 (!strcmp(imp, "Cisco-1.25")))) {
0df73905 2188 /*
2189 * These versions apparently have no clue whatever about
2190 * RSA authentication and will panic and die if they see
2191 * an AUTH_RSA message.
2192 */
51470298 2193 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
19f47a7d 2194 logevent("We believe remote version can't handle SSH-1 RSA authentication");
0df73905 2195 }
2196
5ecd7ad0 2197 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2198 (ssh->cfg.sshbug_hmac2 == AUTO &&
b9f387af 2199 !wc_match("* VShell", imp) &&
831301f6 2200 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2201 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2202 wc_match("2.1 *", imp)))) {
32874aea 2203 /*
2204 * These versions have the HMAC bug.
2205 */
51470298 2206 ssh->remote_bugs |= BUG_SSH2_HMAC;
2e85c969 2207 logevent("We believe remote version has SSH-2 HMAC bug");
7d503c31 2208 }
1dd353b5 2209
5ecd7ad0 2210 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2211 (ssh->cfg.sshbug_derivekey2 == AUTO &&
b9f387af 2212 !wc_match("* VShell", imp) &&
2856a1b9 2213 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
088bde77 2214 /*
2215 * These versions have the key-derivation bug (failing to
2216 * include the literal shared secret in the hashes that
2217 * generate the keys).
2218 */
51470298 2219 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2e85c969 2220 logevent("We believe remote version has SSH-2 key-derivation bug");
088bde77 2221 }
2222
5ecd7ad0 2223 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2224 (ssh->cfg.sshbug_rsapad2 == AUTO &&
831301f6 2225 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2226 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1dd353b5 2227 /*
2e85c969 2228 * These versions have the SSH-2 RSA padding bug.
1dd353b5 2229 */
51470298 2230 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2e85c969 2231 logevent("We believe remote version has SSH-2 RSA padding bug");
1dd353b5 2232 }
8e975795 2233
dda87a28 2234 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2235 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2236 wc_match("OpenSSH_2.[0-2]*", imp))) {
2237 /*
2e85c969 2238 * These versions have the SSH-2 session-ID bug in
dda87a28 2239 * public-key authentication.
2240 */
2241 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2e85c969 2242 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
dda87a28 2243 }
f382c87d 2244
2245 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2246 (ssh->cfg.sshbug_rekey2 == AUTO &&
39b8712f 2247 (wc_match("DigiSSH_2.0", imp) ||
2248 wc_match("OpenSSH_2.[0-4]*", imp) ||
e12d95a5 2249 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2250 wc_match("Sun_SSH_1.0", imp) ||
f4275b53 2251 wc_match("Sun_SSH_1.0.1", imp) ||
96bd26de 2252 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2253 wc_match("WeOnlyDo-*", imp)))) {
f382c87d 2254 /*
2e85c969 2255 * These versions have the SSH-2 rekey bug.
f382c87d 2256 */
2257 ssh->remote_bugs |= BUG_SSH2_REKEY;
2e85c969 2258 logevent("We believe remote version has SSH-2 rekey bug");
f382c87d 2259 }
7d503c31 2260}
2261
d38d6a1f 2262/*
2263 * The `software version' part of an SSH version string is required
2264 * to contain no spaces or minus signs.
2265 */
2266static void ssh_fix_verstring(char *str)
2267{
2268 /* Eat "SSH-<protoversion>-". */
2269 assert(*str == 'S'); str++;
2270 assert(*str == 'S'); str++;
2271 assert(*str == 'H'); str++;
2272 assert(*str == '-'); str++;
2273 while (*str && *str != '-') str++;
2274 assert(*str == '-'); str++;
2275
2276 /* Convert minus signs and spaces in the remaining string into
2277 * underscores. */
2278 while (*str) {
2279 if (*str == '-' || *str == ' ')
2280 *str = '_';
2281 str++;
2282 }
2283}
2284
51470298 2285static int do_ssh_init(Ssh ssh, unsigned char c)
32874aea 2286{
51470298 2287 struct do_ssh_init_state {
2288 int vslen;
2289 char version[10];
2290 char *vstring;
2291 int vstrsize;
2292 int i;
2293 int proto1, proto2;
2294 };
2295 crState(do_ssh_init_state);
374330e2 2296
51470298 2297 crBegin(ssh->do_ssh_init_crstate);
8df7a775 2298
8c1835c0 2299 /* Search for a line beginning with the string "SSH-" in the input. */
2300 for (;;) {
2301 if (c != 'S') goto no;
2302 crReturn(1);
2303 if (c != 'S') goto no;
2304 crReturn(1);
2305 if (c != 'H') goto no;
2306 crReturn(1);
2307 if (c != '-') goto no;
2308 break;
2309 no:
2310 while (c != '\012')
2311 crReturn(1);
2312 crReturn(1);
374330e2 2313 }
8df7a775 2314
51470298 2315 s->vstrsize = 16;
3d88e64d 2316 s->vstring = snewn(s->vstrsize, char);
51470298 2317 strcpy(s->vstring, "SSH-");
2318 s->vslen = 4;
2319 s->i = 0;
374330e2 2320 while (1) {
8df7a775 2321 crReturn(1); /* get another char */
51470298 2322 if (s->vslen >= s->vstrsize - 1) {
2323 s->vstrsize += 16;
3d88e64d 2324 s->vstring = sresize(s->vstring, s->vstrsize, char);
32874aea 2325 }
51470298 2326 s->vstring[s->vslen++] = c;
2327 if (s->i >= 0) {
374330e2 2328 if (c == '-') {
51470298 2329 s->version[s->i] = '\0';
2330 s->i = -1;
2331 } else if (s->i < sizeof(s->version) - 1)
2332 s->version[s->i++] = c;
c4ffc4d0 2333 } else if (c == '\012')
374330e2 2334 break;
2335 }
2336
51470298 2337 ssh->agentfwd_enabled = FALSE;
2338 ssh->rdpkt2_state.incoming_sequence = 0;
960e736a 2339
51470298 2340 s->vstring[s->vslen] = 0;
a7d4653a 2341 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
fb983202 2342 logeventf(ssh, "Server version: %s", s->vstring);
51470298 2343 ssh_detect_bugs(ssh, s->vstring);
c5e9c988 2344
adf799dd 2345 /*
38d228a2 2346 * Decide which SSH protocol version to support.
adf799dd 2347 */
38d228a2 2348
2349 /* Anything strictly below "2.0" means protocol 1 is supported. */
51470298 2350 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
38d228a2 2351 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
51470298 2352 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
38d228a2 2353
86916870 2354 if (ssh->cfg.sshprot == 0 && !s->proto1) {
6b5cf8b4 2355 bombout(("SSH protocol version 1 required by user but not provided by server"));
7ffdbc1a 2356 crStop(0);
38d228a2 2357 }
86916870 2358 if (ssh->cfg.sshprot == 3 && !s->proto2) {
6b5cf8b4 2359 bombout(("SSH protocol version 2 required by user but not provided by server"));
7ffdbc1a 2360 crStop(0);
38d228a2 2361 }
2362
d38d6a1f 2363 {
2364 char *verstring;
2365
2366 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2367 /*
2368 * Construct a v2 version string.
2369 */
a7d4653a 2370 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
d38d6a1f 2371 ssh->version = 2;
2372 } else {
2373 /*
2374 * Construct a v1 version string.
2375 */
a7d4653a 2376 verstring = dupprintf("SSH-%s-%s\012",
d38d6a1f 2377 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2378 s->version : "1.5"),
2379 sshver);
2380 ssh->version = 1;
2381 }
2382
2383 ssh_fix_verstring(verstring);
2384
2385 if (ssh->version == 2) {
4320baf7 2386 size_t len;
d38d6a1f 2387 /*
2388 * Hash our version string and their version string.
2389 */
4320baf7 2390 len = strcspn(verstring, "\015\012");
2391 ssh->v_c = snewn(len + 1, char);
2392 memcpy(ssh->v_c, verstring, len);
2393 ssh->v_c[len] = 0;
2394 len = strcspn(s->vstring, "\015\012");
2395 ssh->v_s = snewn(len + 1, char);
2396 memcpy(ssh->v_s, s->vstring, len);
2397 ssh->v_s[len] = 0;
2398
d38d6a1f 2399 /*
2e85c969 2400 * Initialise SSH-2 protocol.
d38d6a1f 2401 */
2402 ssh->protocol = ssh2_protocol;
2403 ssh2_protocol_setup(ssh);
2404 ssh->s_rdpkt = ssh2_rdpkt;
2405 } else {
2406 /*
2e85c969 2407 * Initialise SSH-1 protocol.
d38d6a1f 2408 */
2409 ssh->protocol = ssh1_protocol;
2410 ssh1_protocol_setup(ssh);
2411 ssh->s_rdpkt = ssh1_rdpkt;
2412 }
2413 logeventf(ssh, "We claim version: %.*s",
a7d4653a 2414 strcspn(verstring, "\015\012"), verstring);
51470298 2415 sk_write(ssh->s, verstring, strlen(verstring));
d38d6a1f 2416 sfree(verstring);
f475e40a 2417 if (ssh->version == 2)
6a755251 2418 do_ssh2_transport(ssh, NULL, -1, NULL);
e5574168 2419 }
d38d6a1f 2420
2421 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2422
125105d1 2423 update_specials_menu(ssh->frontend);
51470298 2424 ssh->state = SSH_STATE_BEFORE_SIZE;
39934deb 2425 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
8df7a775 2426
51470298 2427 sfree(s->vstring);
50526e47 2428
8df7a775 2429 crFinish(0);
2430}
2431
3d9449a1 2432static void ssh_process_incoming_data(Ssh ssh,
2433 unsigned char **data, int *datalen)
2434{
2435 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2436 if (pktin) {
2437 ssh->protocol(ssh, NULL, 0, pktin);
2438 ssh_free_packet(pktin);
2439 }
2440}
2441
2442static void ssh_queue_incoming_data(Ssh ssh,
2443 unsigned char **data, int *datalen)
2444{
2445 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2446 *data += *datalen;
2447 *datalen = 0;
2448}
2449
2450static void ssh_process_queued_incoming_data(Ssh ssh)
2451{
2452 void *vdata;
2453 unsigned char *data;
2454 int len, origlen;
2455
2456 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2457 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2458 data = vdata;
2459 origlen = len;
2460
2461 while (!ssh->frozen && len > 0)
2462 ssh_process_incoming_data(ssh, &data, &len);
2463
2464 if (origlen > len)
2465 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2466 }
2467}
2468
2469static void ssh_set_frozen(Ssh ssh, int frozen)
2470{
a5a6f839 2471 if (ssh->s)
2472 sk_set_frozen(ssh->s, frozen);
3d9449a1 2473 ssh->frozen = frozen;
2474}
2475
51470298 2476static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
8df7a775 2477{
51470298 2478 crBegin(ssh->ssh_gotdata_crstate);
8df7a775 2479
2480 /*
2481 * To begin with, feed the characters one by one to the
2482 * protocol initialisation / selection function do_ssh_init().
2483 * When that returns 0, we're done with the initial greeting
2484 * exchange and can move on to packet discipline.
2485 */
2486 while (1) {
51470298 2487 int ret; /* need not be kept across crReturn */
8df7a775 2488 if (datalen == 0)
2489 crReturnV; /* more data please */
51470298 2490 ret = do_ssh_init(ssh, *data);
32874aea 2491 data++;
2492 datalen--;
8df7a775 2493 if (ret == 0)
2494 break;
2495 }
2496
2497 /*
2498 * We emerge from that loop when the initial negotiation is
2499 * over and we have selected an s_rdpkt function. Now pass
2500 * everything to s_rdpkt, and then pass the resulting packets
2501 * to the proper protocol handler.
2502 */
3d9449a1 2503
8df7a775 2504 while (1) {
e375106c 2505 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2506 if (ssh->frozen) {
3d9449a1 2507 ssh_queue_incoming_data(ssh, &data, &datalen);
e375106c 2508 /* This uses up all data and cannot cause anything interesting
2509 * to happen; indeed, for anything to happen at all, we must
2510 * return, so break out. */
2511 break;
2512 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2513 /* This uses up some or all data, and may freeze the
2514 * session. */
2515 ssh_process_queued_incoming_data(ssh);
2516 } else {
2517 /* This uses up some or all data, and may freeze the
2518 * session. */
2519 ssh_process_incoming_data(ssh, &data, &datalen);
2520 }
2521 /* FIXME this is probably EBW. */
ff3187f6 2522 if (ssh->state == SSH_STATE_CLOSED)
2523 return;
8df7a775 2524 }
e375106c 2525 /* We're out of data. Go and get some more. */
8df7a775 2526 crReturnV;
2527 }
2528 crFinishV;
2529}
2530
ac934965 2531static int ssh_do_close(Ssh ssh, int notify_exit)
32874aea 2532{
80ffa58b 2533 int ret = 0;
36f94d1f 2534 struct ssh_channel *c;
2535
51470298 2536 ssh->state = SSH_STATE_CLOSED;
ecbb0000 2537 expire_timer_context(ssh);
51470298 2538 if (ssh->s) {
2539 sk_close(ssh->s);
2540 ssh->s = NULL;
ac934965 2541 if (notify_exit)
2542 notify_remote_exit(ssh->frontend);
2543 else
2544 ret = 1;
f3ab576e 2545 }
36f94d1f 2546 /*
80ffa58b 2547 * Now we must shut down any port- and X-forwarded channels going
36f94d1f 2548 * through this connection.
2549 */
74a98066 2550 if (ssh->channels) {
80ffa58b 2551 while (NULL != (c = index234(ssh->channels, 0))) {
74a98066 2552 switch (c->type) {
2553 case CHAN_X11:
2554 x11_close(c->u.x11.s);
2555 break;
2556 case CHAN_SOCKDATA:
2557 pfd_close(c->u.pfd.s);
2558 break;
2559 }
80ffa58b 2560 del234(ssh->channels, c); /* moving next one to index 0 */
74a98066 2561 if (ssh->version == 2)
2562 bufchain_clear(&c->v.v2.outbuffer);
2563 sfree(c);
36f94d1f 2564 }
36f94d1f 2565 }
f8c9f9df 2566 /*
2567 * Go through port-forwardings, and close any associated
2568 * listening sockets.
2569 */
2570 if (ssh->portfwds) {
2571 struct ssh_portfwd *pf;
2572 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2573 /* Dispose of any listening socket. */
2574 if (pf->local)
2575 pfd_terminate(pf->local);
2576 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2577 free_portfwd(pf);
2578 }
2579 }
ac934965 2580
2581 return ret;
36f94d1f 2582}
2583
7555d6a5 2584static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2585 const char *error_msg, int error_code)
2586{
2587 Ssh ssh = (Ssh) plug;
2588 char addrbuf[256], *msg;
2589
2590 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2591
2592 if (type == 0)
2593 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2594 else
2595 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2596
2597 logevent(msg);
fb983202 2598 sfree(msg);
7555d6a5 2599}
2600
cbe2d68f 2601static int ssh_closing(Plug plug, const char *error_msg, int error_code,
36f94d1f 2602 int calling_back)
2603{
2604 Ssh ssh = (Ssh) plug;
ac934965 2605 int need_notify = ssh_do_close(ssh, FALSE);
2606
9e296bfa 2607 if (!error_msg) {
2608 if (!ssh->close_expected)
2609 error_msg = "Server unexpectedly closed network connection";
2610 else
2611 error_msg = "Server closed network connection";
ac934965 2612 }
2613
2425184b 2614 if (need_notify)
2615 notify_remote_exit(ssh->frontend);
2616
9e296bfa 2617 if (error_msg)
247308b5 2618 logevent(error_msg);
9e296bfa 2619 if (!ssh->close_expected || !ssh->clean_exit)
971bcc0a 2620 connection_fatal(ssh->frontend, "%s", error_msg);
7e78000d 2621 return 0;
2622}
2623
32874aea 2624static int ssh_receive(Plug plug, int urgent, char *data, int len)
2625{
51470298 2626 Ssh ssh = (Ssh) plug;
d8baa528 2627 ssh_gotdata(ssh, (unsigned char *)data, len);
51470298 2628 if (ssh->state == SSH_STATE_CLOSED) {
ac934965 2629 ssh_do_close(ssh, TRUE);
32874aea 2630 return 0;
3257deae 2631 }
fef97f43 2632 return 1;
374330e2 2633}
2634
5471d09a 2635static void ssh_sent(Plug plug, int bufsize)
2636{
51470298 2637 Ssh ssh = (Ssh) plug;
5471d09a 2638 /*
2639 * If the send backlog on the SSH socket itself clears, we
2640 * should unthrottle the whole world if it was throttled.
2641 */
2642 if (bufsize < SSH_MAX_BACKLOG)
51470298 2643 ssh_throttle_all(ssh, 0, bufsize);
5471d09a 2644}
2645
fb09bf1c 2646/*
8df7a775 2647 * Connect to specified host and port.
2648 * Returns an error message, or NULL on success.
6e1ebb76 2649 * Also places the canonical host name into `realhost'. It must be
2650 * freed by the caller.
8df7a775 2651 */
cbe2d68f 2652static const char *connect_to_host(Ssh ssh, char *host, int port,
79bf227b 2653 char **realhost, int nodelay, int keepalive)
8df7a775 2654{
51470298 2655 static const struct plug_function_table fn_table = {
7555d6a5 2656 ssh_log,
7e78000d 2657 ssh_closing,
5471d09a 2658 ssh_receive,
2659 ssh_sent,
2660 NULL
51470298 2661 };
7e78000d 2662
8df7a775 2663 SockAddr addr;
cbe2d68f 2664 const char *err;
8df7a775 2665
3d88e64d 2666 ssh->savedhost = snewn(1 + strlen(host), char);
51470298 2667 strcpy(ssh->savedhost, host);
8df7a775 2668
2669 if (port < 0)
2670 port = 22; /* default ssh port */
51470298 2671 ssh->savedport = port;
8df7a775 2672
2673 /*
2674 * Try to find host.
2675 */
05581745 2676 logeventf(ssh, "Looking up host \"%s\"%s", host,
2677 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2678 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2679 addr = name_lookup(host, port, realhost, &ssh->cfg,
2680 ssh->cfg.addressfamily);
170c1e6e 2681 if ((err = sk_addr_error(addr)) != NULL) {
2682 sk_addr_free(addr);
8df7a775 2683 return err;
170c1e6e 2684 }
8df7a775 2685
8df7a775 2686 /*
2687 * Open socket.
2688 */
51470298 2689 ssh->fn = &fn_table;
e8fa8f62 2690 ssh->s = new_connection(addr, *realhost, port,
79bf227b 2691 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
70e5d0fd 2692 if ((err = sk_socket_error(ssh->s)) != NULL) {
51470298 2693 ssh->s = NULL;
39934deb 2694 notify_remote_exit(ssh->frontend);
8df7a775 2695 return err;
67c4ba2e 2696 }
8df7a775 2697
8df7a775 2698 return NULL;
2699}
2700
2701/*
5471d09a 2702 * Throttle or unthrottle the SSH connection.
2703 */
51470298 2704static void ssh1_throttle(Ssh ssh, int adjust)
5471d09a 2705{
51470298 2706 int old_count = ssh->v1_throttle_count;
2707 ssh->v1_throttle_count += adjust;
2708 assert(ssh->v1_throttle_count >= 0);
2709 if (ssh->v1_throttle_count && !old_count) {
3d9449a1 2710 ssh_set_frozen(ssh, 1);
51470298 2711 } else if (!ssh->v1_throttle_count && old_count) {
3d9449a1 2712 ssh_set_frozen(ssh, 0);
5471d09a 2713 }
2714}
2715
2716/*
2717 * Throttle or unthrottle _all_ local data streams (for when sends
2718 * on the SSH connection itself back up).
2719 */
51470298 2720static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
5471d09a 2721{
2722 int i;
2723 struct ssh_channel *c;
2724
51470298 2725 if (enable == ssh->throttled_all)
5471d09a 2726 return;
51470298 2727 ssh->throttled_all = enable;
2728 ssh->overall_bufsize = bufsize;
2729 if (!ssh->channels)
5471d09a 2730 return;
51470298 2731 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5471d09a 2732 switch (c->type) {
2733 case CHAN_MAINSESSION:
2734 /*
2735 * This is treated separately, outside the switch.
2736 */
2737 break;
2738 case CHAN_X11:
2739 x11_override_throttle(c->u.x11.s, enable);
2740 break;
2741 case CHAN_AGENT:
2742 /* Agent channels require no buffer management. */
2743 break;
2744 case CHAN_SOCKDATA:
36f94d1f 2745 pfd_override_throttle(c->u.pfd.s, enable);
5471d09a 2746 break;
2747 }
2748 }
2749}
2750
f11d78f2 2751static void ssh_agent_callback(void *sshv, void *reply, int replylen)
839f10db 2752{
2753 Ssh ssh = (Ssh) sshv;
2754
2755 ssh->agent_response = reply;
2756 ssh->agent_response_len = replylen;
2757
2758 if (ssh->version == 1)
ff3187f6 2759 do_ssh1_login(ssh, NULL, -1, NULL);
839f10db 2760 else
ff3187f6 2761 do_ssh2_authconn(ssh, NULL, -1, NULL);
839f10db 2762}
2763
3d9449a1 2764static void ssh_dialog_callback(void *sshv, int ret)
2765{
2766 Ssh ssh = (Ssh) sshv;
2767
2768 ssh->user_response = ret;
2769
2770 if (ssh->version == 1)
2771 do_ssh1_login(ssh, NULL, -1, NULL);
2772 else
2773 do_ssh2_transport(ssh, NULL, -1, NULL);
2774
2775 /*
2776 * This may have unfrozen the SSH connection, so do a
2777 * queued-data run.
2778 */
2779 ssh_process_queued_incoming_data(ssh);
2780}
2781
f11d78f2 2782static void ssh_agentf_callback(void *cv, void *reply, int replylen)
839f10db 2783{
2784 struct ssh_channel *c = (struct ssh_channel *)cv;
2785 Ssh ssh = c->ssh;
2786 void *sentreply = reply;
2787
2788 if (!sentreply) {
2789 /* Fake SSH_AGENT_FAILURE. */
2790 sentreply = "\0\0\0\1\5";
2791 replylen = 5;
2792 }
2793 if (ssh->version == 2) {
2794 ssh2_add_channel_data(c, sentreply, replylen);
2795 ssh2_try_send(c);
2796 } else {
2797 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2798 PKT_INT, c->remoteid,
9a10ecf4 2799 PKTT_DATA,
839f10db 2800 PKT_INT, replylen,
2801 PKT_DATA, sentreply, replylen,
9a10ecf4 2802 PKTT_OTHER,
839f10db 2803 PKT_END);
2804 }
2805 if (reply)
2806 sfree(reply);
2807}
2808
0405e71f 2809/*
9e296bfa 2810 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2811 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2812 * => log `wire_reason'.
2813 */
2814static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2815 int code, int clean_exit)
2816{
2817 char *error;
2818 if (!client_reason)
2819 client_reason = wire_reason;
2820 if (client_reason)
2821 error = dupprintf("Disconnected: %s", client_reason);
2822 else
2823 error = dupstr("Disconnected");
2824 if (wire_reason) {
2825 if (ssh->version == 1) {
2826 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2827 PKT_END);
2828 } else if (ssh->version == 2) {
2829 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2830 ssh2_pkt_adduint32(pktout, code);
2831 ssh2_pkt_addstring(pktout, wire_reason);
2832 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2833 ssh2_pkt_send_noqueue(ssh, pktout);
2834 }
2835 }
2836 ssh->close_expected = TRUE;
2837 ssh->clean_exit = clean_exit;
2838 ssh_closing((Plug)ssh, error, 0, 0);
2839 sfree(error);
2840}
2841
2842/*
fb09bf1c 2843 * Handle the key exchange and user authentication phases.
2844 */
ff3187f6 2845static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2846 struct Packet *pktin)
fb09bf1c 2847{
0016d70b 2848 int i, j, ret;
2849 unsigned char cookie[8], *ptr;
374330e2 2850 struct RSAKey servkey, hostkey;
2851 struct MD5Context md5c;
51470298 2852 struct do_ssh1_login_state {
2853 int len;
2854 unsigned char *rsabuf, *keystr1, *keystr2;
2855 unsigned long supported_ciphers_mask, supported_auths_mask;
2856 int tried_publickey, tried_agent;
2857 int tis_auth_refused, ccard_auth_refused;
2858 unsigned char session_id[16];
2859 int cipher_type;
2860 char username[100];
2861 void *publickey_blob;
2862 int publickey_bloblen;
edd0cb8a 2863 char *publickey_comment;
2864 int publickey_encrypted;
2865 prompts_t *cur_prompt;
51470298 2866 char c;
2867 int pwpkt_type;
2868 unsigned char request[5], *response, *p;
2869 int responselen;
2870 int keyi, nkeys;
2871 int authed;
2872 struct RSAKey key;
2873 Bignum challenge;
2874 char *commentp;
2875 int commentlen;
3d9449a1 2876 int dlgret;
51470298 2877 };
2878 crState(do_ssh1_login_state);
2879
2880 crBegin(ssh->do_ssh1_login_crstate);
374330e2 2881
ff3187f6 2882 if (!pktin)
2883 crWaitUntil(pktin);
374330e2 2884
ff3187f6 2885 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
6b5cf8b4 2886 bombout(("Public key packet not received"));
7ffdbc1a 2887 crStop(0);
8d5de777 2888 }
374330e2 2889
c5e9c988 2890 logevent("Received public keys");
374330e2 2891
ff3187f6 2892 ptr = ssh_pkt_getdata(pktin, 8);
0016d70b 2893 if (!ptr) {
2e85c969 2894 bombout(("SSH-1 public key packet stopped before random cookie"));
0016d70b 2895 crStop(0);
2896 }
2897 memcpy(cookie, ptr, 8);
374330e2 2898
ff3187f6 2899 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2900 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2e85c969 2901 bombout(("Failed to read SSH-1 public keys from public key packet"));
0016d70b 2902 crStop(0);
2903 }
374330e2 2904
c5e9c988 2905 /*
1c2a93c4 2906 * Log the host key fingerprint.
c5e9c988 2907 */
c5e9c988 2908 {
2909 char logmsg[80];
1c2a93c4 2910 logevent("Host key fingerprint is:");
c5e9c988 2911 strcpy(logmsg, " ");
32874aea 2912 hostkey.comment = NULL;
2913 rsa_fingerprint(logmsg + strlen(logmsg),
2914 sizeof(logmsg) - strlen(logmsg), &hostkey);
c5e9c988 2915 logevent(logmsg);
2916 }
2917
ff3187f6 2918 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2919 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2920 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
bea1ef5f 2921
51470298 2922 ssh->v1_local_protoflags =
2923 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2924 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
b96dc54c 2925
c5e9c988 2926 MD5Init(&md5c);
51470298 2927 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2928 MD5Update(&md5c, s->keystr1, servkey.bytes);
0016d70b 2929 MD5Update(&md5c, cookie, 8);
51470298 2930 MD5Final(s->session_id, &md5c);
374330e2 2931
32874aea 2932 for (i = 0; i < 32; i++)
51470298 2933 ssh->session_key[i] = random_byte();
374330e2 2934
0016d70b 2935 /*
2936 * Verify that the `bits' and `bytes' parameters match.
2937 */
2938 if (hostkey.bits > hostkey.bytes * 8 ||
2939 servkey.bits > servkey.bytes * 8) {
2e85c969 2940 bombout(("SSH-1 public keys were badly formatted"));
0016d70b 2941 crStop(0);
2942 }
2943
51470298 2944 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
374330e2 2945
3d88e64d 2946 s->rsabuf = snewn(s->len, unsigned char);
374330e2 2947
89ee5268 2948 /*
2949 * Verify the host key.
2950 */
2951 {
32874aea 2952 /*
2953 * First format the key into a string.
2954 */
2955 int len = rsastr_len(&hostkey);
2956 char fingerprint[100];
3d88e64d 2957 char *keystr = snewn(len, char);
32874aea 2958 rsastr_fmt(keystr, &hostkey);
2959 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3d9449a1 2960
2961 ssh_set_frozen(ssh, 1);
2962 s->dlgret = verify_ssh_host_key(ssh->frontend,
2963 ssh->savedhost, ssh->savedport,
2964 "rsa", keystr, fingerprint,
2965 ssh_dialog_callback, ssh);
32874aea 2966 sfree(keystr);
3d9449a1 2967 if (s->dlgret < 0) {
2968 do {
2969 crReturn(0);
2970 if (pktin) {
2971 bombout(("Unexpected data from server while waiting"
2972 " for user host key response"));
2973 crStop(0);
2974 }
2975 } while (pktin || inlen > 0);
2976 s->dlgret = ssh->user_response;
2977 }
2978 ssh_set_frozen(ssh, 0);
2979
2980 if (s->dlgret == 0) {
9e296bfa 2981 ssh_disconnect(ssh, "User aborted at host key verification",
2982 NULL, 0, TRUE);
2b3f6c19 2983 crStop(0);
3d9449a1 2984 }
32874aea 2985 }
2986
2987 for (i = 0; i < 32; i++) {
51470298 2988 s->rsabuf[i] = ssh->session_key[i];
374330e2 2989 if (i < 16)
51470298 2990 s->rsabuf[i] ^= s->session_id[i];
374330e2 2991 }
2992
2993 if (hostkey.bytes > servkey.bytes) {
0016d70b 2994 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2995 if (ret)
2996 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
374330e2 2997 } else {
0016d70b 2998 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2999 if (ret)
3000 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3001 }
3002 if (!ret) {
2e85c969 3003 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
0016d70b 3004 crStop(0);
374330e2 3005 }
3006
c5e9c988 3007 logevent("Encrypted session key");
3008
ca20bfcf 3009 {
3010 int cipher_chosen = 0, warn = 0;
3011 char *cipher_string = NULL;
51470298 3012 int i;
ca20bfcf 3013 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
86916870 3014 int next_cipher = ssh->cfg.ssh_cipherlist[i];
ca20bfcf 3015 if (next_cipher == CIPHER_WARN) {
3016 /* If/when we choose a cipher, warn about it */
3017 warn = 1;
3018 } else if (next_cipher == CIPHER_AES) {
3019 /* XXX Probably don't need to mention this. */
2e85c969 3020 logevent("AES not supported in SSH-1, skipping");
ca20bfcf 3021 } else {
3022 switch (next_cipher) {
51470298 3023 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
ca20bfcf 3024 cipher_string = "3DES"; break;
51470298 3025 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
ca20bfcf 3026 cipher_string = "Blowfish"; break;
51470298 3027 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
ca20bfcf 3028 cipher_string = "single-DES"; break;
3029 }
51470298 3030 if (s->supported_ciphers_mask & (1 << s->cipher_type))
ca20bfcf 3031 cipher_chosen = 1;
3032 }
3033 }
3034 if (!cipher_chosen) {
51470298 3035 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2e85c969 3036 bombout(("Server violates SSH-1 protocol by not "
ca20bfcf 3037 "supporting 3DES encryption"));
3038 else
3039 /* shouldn't happen */
6b5cf8b4 3040 bombout(("No supported ciphers found"));
7ffdbc1a 3041 crStop(0);
a99a05c0 3042 }
ca20bfcf 3043
3044 /* Warn about chosen cipher if necessary. */
bb348ab1 3045 if (warn) {
3d9449a1 3046 ssh_set_frozen(ssh, 1);
3047 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3048 ssh_dialog_callback, ssh);
3049 if (s->dlgret < 0) {
3050 do {
3051 crReturn(0);
3052 if (pktin) {
3053 bombout(("Unexpected data from server while waiting"
3054 " for user response"));
3055 crStop(0);
3056 }
3057 } while (pktin || inlen > 0);
3058 s->dlgret = ssh->user_response;
3059 }
3060 ssh_set_frozen(ssh, 0);
3061 if (s->dlgret == 0) {
9e296bfa 3062 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3063 0, TRUE);
96ccde8b 3064 crStop(0);
3d9449a1 3065 }
bb348ab1 3066 }
bea1ef5f 3067 }
ca20bfcf 3068
51470298 3069 switch (s->cipher_type) {
32874aea 3070 case SSH_CIPHER_3DES:
3071 logevent("Using 3DES encryption");
3072 break;
3073 case SSH_CIPHER_DES:
3074 logevent("Using single-DES encryption");
3075 break;
3076 case SSH_CIPHER_BLOWFISH:
3077 logevent("Using Blowfish encryption");
3078 break;
c5e9c988 3079 }
bea1ef5f 3080
51470298 3081 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3082 PKT_CHAR, s->cipher_type,
32874aea 3083 PKT_DATA, cookie, 8,
51470298 3084 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3085 PKT_DATA, s->rsabuf, s->len,
3086 PKT_INT, ssh->v1_local_protoflags, PKT_END);
fb09bf1c 3087
c5e9c988 3088 logevent("Trying to enable encryption...");
374330e2 3089
51470298 3090 sfree(s->rsabuf);
374330e2 3091
51470298 3092 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3093 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3094 &ssh_3des);
371e569c 3095 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3096 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
57356d63 3097 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
374330e2 3098
0183b242 3099 ssh->crcda_ctx = crcda_make_context();
3100 logevent("Installing CRC compensation attack detector");
3101
679539d7 3102 if (servkey.modulus) {
3103 sfree(servkey.modulus);
3104 servkey.modulus = NULL;
3105 }
3106 if (servkey.exponent) {
3107 sfree(servkey.exponent);
3108 servkey.exponent = NULL;
3109 }
3110 if (hostkey.modulus) {
3111 sfree(hostkey.modulus);
3112 hostkey.modulus = NULL;
3113 }
3114 if (hostkey.exponent) {
3115 sfree(hostkey.exponent);
3116 hostkey.exponent = NULL;
3117 }
ff3187f6 3118 crWaitUntil(pktin);
374330e2 3119
ff3187f6 3120 if (pktin->type != SSH1_SMSG_SUCCESS) {
6b5cf8b4 3121 bombout(("Encryption not successfully enabled"));
7ffdbc1a 3122 crStop(0);
8d5de777 3123 }
374330e2 3124
c5e9c988 3125 logevent("Successfully started encryption");
3126
edd0cb8a 3127 fflush(stdout); /* FIXME eh? */
374330e2 3128 {
aa09f7d0 3129 if (!*ssh->cfg.username) {
edd0cb8a 3130 int ret; /* need not be kept over crReturn */
3131 s->cur_prompt = new_prompts(ssh->frontend);
3132 s->cur_prompt->to_server = TRUE;
3133 s->cur_prompt->name = dupstr("SSH login name");
3134 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3135 lenof(s->username));
3136 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3137 while (ret < 0) {
51470298 3138 ssh->send_ok = 1;
edd0cb8a 3139 crWaitUntil(!pktin);
3140 ret = get_userpass_input(s->cur_prompt, in, inlen);
3141 ssh->send_ok = 0;
3142 }
3143 if (!ret) {
3144 /*
3145 * Failed to get a username. Terminate.
3146 */
3147 free_prompts(s->cur_prompt);
3148 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3149 crStop(0);
32874aea 3150 }
edd0cb8a 3151 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3152 lenof(s->username));
3153 free_prompts(s->cur_prompt);
32874aea 3154 } else {
86916870 3155 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 3156 s->username[sizeof(s->username)-1] = '\0';
374330e2 3157 }
fb09bf1c 3158
51470298 3159 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
c5e9c988 3160 {
edd0cb8a 3161 char *userlog = dupprintf("Sent username \"%s\"", s->username);
c5e9c988 3162 logevent(userlog);
32874aea 3163 if (flags & FLAG_INTERACTIVE &&
3164 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
51470298 3165 c_write_str(ssh, userlog);
edd0cb8a 3166 c_write_str(ssh, "\r\n");
3c8e959b 3167 }
edd0cb8a 3168 sfree(userlog);
c5e9c988 3169 }
374330e2 3170 }
3171
ff3187f6 3172 crWaitUntil(pktin);
374330e2 3173
51470298 3174 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
0df73905 3175 /* We must not attempt PK auth. Pretend we've already tried it. */
51470298 3176 s->tried_publickey = s->tried_agent = 1;
0df73905 3177 } else {
51470298 3178 s->tried_publickey = s->tried_agent = 0;
0df73905 3179 }
51470298 3180 s->tis_auth_refused = s->ccard_auth_refused = 0;
edd0cb8a 3181 /*
3182 * Load the public half of any configured keyfile for later use.
3183 */
9a30e26b 3184 if (!filename_is_null(ssh->cfg.keyfile)) {
edd0cb8a 3185 int keytype;
3186 logeventf(ssh, "Reading private key file \"%.150s\"",
3187 filename_to_str(&ssh->cfg.keyfile));
3188 keytype = key_type(&ssh->cfg.keyfile);
3189 if (keytype == SSH_KEYTYPE_SSH1) {
3190 const char *error;
3191 if (rsakey_pubblob(&ssh->cfg.keyfile,
3192 &s->publickey_blob, &s->publickey_bloblen,
3193 &s->publickey_comment, &error)) {
3194 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3195 NULL);
3196 } else {
3197 char *msgbuf;
3198 logeventf(ssh, "Unable to load private key (%s)", error);
3199 msgbuf = dupprintf("Unable to load private key file "
3200 "\"%.150s\" (%s)\r\n",
3201 filename_to_str(&ssh->cfg.keyfile),
3202 error);
3203 c_write_str(ssh, msgbuf);
3204 sfree(msgbuf);
3205 s->publickey_blob = NULL;
3206 }
3207 } else {
3208 char *msgbuf;
3209 logeventf(ssh, "Unable to use this key file (%s)",
3210 key_type_to_str(keytype));
3211 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3212 " (%s)\r\n",
3213 filename_to_str(&ssh->cfg.keyfile),
3214 key_type_to_str(keytype));
3215 c_write_str(ssh, msgbuf);
3216 sfree(msgbuf);
51470298 3217 s->publickey_blob = NULL;
edd0cb8a 3218 }
396778f1 3219 } else
51470298 3220 s->publickey_blob = NULL;
7cca0d81 3221
ff3187f6 3222 while (pktin->type == SSH1_SMSG_FAILURE) {
51470298 3223 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
614a20a0 3224
973612f5 3225 if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
32874aea 3226 /*
3227 * Attempt RSA authentication using Pageant.
3228 */
32874aea 3229 void *r;
3230
51470298 3231 s->authed = FALSE;
3232 s->tried_agent = 1;
32874aea 3233 logevent("Pageant is running. Requesting keys.");
3234
3235 /* Request the keys held by the agent. */
51470298 3236 PUT_32BIT(s->request, 1);
3237 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
839f10db 3238 if (!agent_query(s->request, 5, &r, &s->responselen,
3239 ssh_agent_callback, ssh)) {
3240 do {
3241 crReturn(0);
ff3187f6 3242 if (pktin) {
839f10db 3243 bombout(("Unexpected data from server while waiting"
3244 " for agent response"));
3245 crStop(0);
3246 }
ff3187f6 3247 } while (pktin || inlen > 0);
839f10db 3248 r = ssh->agent_response;
3249 s->responselen = ssh->agent_response_len;
3250 }
51470298 3251 s->response = (unsigned char *) r;
3252 if (s->response && s->responselen >= 5 &&
3253 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3254 s->p = s->response + 5;
3255 s->nkeys = GET_32BIT(s->p);
3256 s->p += 4;
2e85c969 3257 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
51470298 3258 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
94cd7c3a 3259 unsigned char *pkblob = s->p;
51470298 3260 s->p += 4;
0016d70b 3261 {
3262 int n, ok = FALSE;
3263 do { /* do while (0) to make breaking easy */
3264 n = ssh1_read_bignum
3265 (s->p, s->responselen-(s->p-s->response),
3266 &s->key.exponent);
3267 if (n < 0)
3268 break;
3269 s->p += n;
3270 n = ssh1_read_bignum
3271 (s->p, s->responselen-(s->p-s->response),
3272 &s->key.modulus);
3273 if (n < 0)
3274 break;
3275 s->p += n;
3276 if (s->responselen - (s->p-s->response) < 4)
3277 break;
3278 s->commentlen = GET_32BIT(s->p);
3279 s->p += 4;
3280 if (s->responselen - (s->p-s->response) <
3281 s->commentlen)
3282 break;
3283 s->commentp = (char *)s->p;
3284 s->p += s->commentlen;
3285 ok = TRUE;
3286 } while (0);
3287 if (!ok) {
3288 logevent("Pageant key list packet was truncated");
3289 break;
3290 }
3291 }
94cd7c3a 3292 if (s->publickey_blob) {
3293 if (!memcmp(pkblob, s->publickey_blob,
3294 s->publickey_bloblen)) {
3295 logeventf(ssh, "Pageant key #%d matches "
3296 "configured key file", s->keyi);
3297 s->tried_publickey = 1;
3298 } else
3299 /* Skip non-configured key */
3300 continue;
3301 }
3302 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
51470298 3303 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3304 PKT_BIGNUM, s->key.modulus, PKT_END);
ff3187f6 3305 crWaitUntil(pktin);
3306 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
32874aea 3307 logevent("Key refused");
3308 continue;
3309 }
3310 logevent("Received RSA challenge");
ff3187f6 3311 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
0016d70b 3312 bombout(("Server's RSA challenge was badly formatted"));
3313 crStop(0);
3314 }
3315
32874aea 3316 {
3317 char *agentreq, *q, *ret;
2d466ffd 3318 void *vret;
32874aea 3319 int len, retlen;
3320 len = 1 + 4; /* message type, bit count */
51470298 3321 len += ssh1_bignum_length(s->key.exponent);
3322 len += ssh1_bignum_length(s->key.modulus);
3323 len += ssh1_bignum_length(s->challenge);
32874aea 3324 len += 16; /* session id */
3325 len += 4; /* response format */
3d88e64d 3326 agentreq = snewn(4 + len, char);
32874aea 3327 PUT_32BIT(agentreq, len);
3328 q = agentreq + 4;
3329 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
51470298 3330 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
32874aea 3331 q += 4;
51470298 3332 q += ssh1_write_bignum(q, s->key.exponent);
3333 q += ssh1_write_bignum(q, s->key.modulus);
3334 q += ssh1_write_bignum(q, s->challenge);
3335 memcpy(q, s->session_id, 16);
32874aea 3336 q += 16;
3337 PUT_32BIT(q, 1); /* response format */
839f10db 3338 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3339 ssh_agent_callback, ssh)) {
3340 sfree(agentreq);
3341 do {
3342 crReturn(0);
ff3187f6 3343 if (pktin) {
839f10db 3344 bombout(("Unexpected data from server"
3345 " while waiting for agent"
3346 " response"));
3347 crStop(0);
3348 }
ff3187f6 3349 } while (pktin || inlen > 0);
839f10db 3350 vret = ssh->agent_response;
3351 retlen = ssh->agent_response_len;
3352 } else
3353 sfree(agentreq);
2d466ffd 3354 ret = vret;
32874aea 3355 if (ret) {
3356 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3357 logevent("Sending Pageant's response");
51470298 3358 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
32874aea 3359 PKT_DATA, ret + 5, 16,
3360 PKT_END);
3361 sfree(ret);
ff3187f6 3362 crWaitUntil(pktin);
3363 if (pktin->type == SSH1_SMSG_SUCCESS) {
32874aea 3364 logevent
3365 ("Pageant's response accepted");
3366 if (flags & FLAG_VERBOSE) {
51470298 3367 c_write_str(ssh, "Authenticated using"
3368 " RSA key \"");
3369 c_write(ssh, s->commentp,
3370 s->commentlen);
3371 c_write_str(ssh, "\" from agent\r\n");
32874aea 3372 }
51470298 3373 s->authed = TRUE;
32874aea 3374 } else
3375 logevent
3376 ("Pageant's response not accepted");
3377 } else {
3378 logevent
3379 ("Pageant failed to answer challenge");
3380 sfree(ret);
3381 }
3382 } else {
3383 logevent("No reply received from Pageant");
3384 }
3385 }
51470298 3386 freebn(s->key.exponent);
3387 freebn(s->key.modulus);
3388 freebn(s->challenge);
3389 if (s->authed)
32874aea 3390 break;
3391 }
29b1d0b3 3392 sfree(s->response);
94cd7c3a 3393 if (s->publickey_blob && !s->tried_publickey)
3394 logevent("Configured key file not in Pageant");
32874aea 3395 }
51470298 3396 if (s->authed)
32874aea 3397 break;
3398 }
edd0cb8a 3399 if (s->publickey_blob && !s->tried_publickey) {
3400 /*
3401 * Try public key authentication with the specified
3402 * key file.
3403 */
3404 int got_passphrase; /* need not be kept over crReturn */
3405 if (flags & FLAG_VERBOSE)
3406 c_write_str(ssh, "Trying public key authentication.\r\n");
3407 logeventf(ssh, "Trying public key \"%s\"",
3408 filename_to_str(&ssh->cfg.keyfile));
3409 s->tried_publickey = 1;
3410 got_passphrase = FALSE;
3411 while (!got_passphrase) {
3412 /*
3413 * Get a passphrase, if necessary.
3414 */
3415 char *passphrase = NULL; /* only written after crReturn */
3416 const char *error;
3417 if (!s->publickey_encrypted) {
3418 if (flags & FLAG_VERBOSE)
3419 c_write_str(ssh, "No passphrase required.\r\n");
3420 passphrase = NULL;
3421 } else {
3422 int ret; /* need not be kept over crReturn */
3423 s->cur_prompt = new_prompts(ssh->frontend);
3424 s->cur_prompt->to_server = FALSE;
3425 s->cur_prompt->name = dupstr("SSH key passphrase");
3426 add_prompt(s->cur_prompt,
3427 dupprintf("Passphrase for key \"%.100s\": ",
3428 s->publickey_comment),
3429 FALSE, SSH_MAX_PASSWORD_LEN);
3430 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3431 while (ret < 0) {
3432 ssh->send_ok = 1;
3433 crWaitUntil(!pktin);
3434 ret = get_userpass_input(s->cur_prompt, in, inlen);
3435 ssh->send_ok = 0;
3436 }
3437 if (!ret) {
3438 /* Failed to get a passphrase. Terminate. */
3439 free_prompts(s->cur_prompt);
3440 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3441 0, TRUE);
3442 crStop(0);
3443 }
3444 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3445 free_prompts(s->cur_prompt);
3446 }
3447 /*
3448 * Try decrypting key with passphrase.
3449 */
3450 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3451 &error);
3452 if (passphrase) {
3453 memset(passphrase, 0, strlen(passphrase));
3454 sfree(passphrase);
3455 }
3456 if (ret == 1) {
3457 /* Correct passphrase. */
3458 got_passphrase = TRUE;
3459 } else if (ret == 0) {
3460 c_write_str(ssh, "Couldn't load private key from ");
3461 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3462 c_write_str(ssh, " (");
3463 c_write_str(ssh, error);
3464 c_write_str(ssh, ").\r\n");
3465 got_passphrase = FALSE;
3466 break; /* go and try something else */
3467 } else if (ret == -1) {
3468 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
edd0cb8a 3469 got_passphrase = FALSE;
3470 /* and try again */
43536490 3471 } else {
3472 assert(0 && "unexpected return from loadrsakey()");
edd0cb8a 3473 }
3474 }
3475
3476 if (got_passphrase) {
3477
3478 /*
3479 * Send a public key attempt.
3480 */
3481 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3482 PKT_BIGNUM, s->key.modulus, PKT_END);
3483
3484 crWaitUntil(pktin);
3485 if (pktin->type == SSH1_SMSG_FAILURE) {
3486 c_write_str(ssh, "Server refused our public key.\r\n");
7b575324 3487 continue; /* go and try something else */
edd0cb8a 3488 }
3489 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3490 bombout(("Bizarre response to offer of public key"));
3491 crStop(0);
3492 }
3493
3494 {
3495 int i;
3496 unsigned char buffer[32];
3497 Bignum challenge, response;
3498
3499 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3500 bombout(("Server's RSA challenge was badly formatted"));
3501 crStop(0);
3502 }
3503 response = rsadecrypt(challenge, &s->key);
3504 freebn(s->key.private_exponent);/* burn the evidence */
3505
3506 for (i = 0; i < 32; i++) {
3507 buffer[i] = bignum_byte(response, 31 - i);
3508 }
3509
3510 MD5Init(&md5c);
3511 MD5Update(&md5c, buffer, 32);
3512 MD5Update(&md5c, s->session_id, 16);
3513 MD5Final(buffer, &md5c);
3514
3515 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3516 PKT_DATA, buffer, 16, PKT_END);
3517
3518 freebn(challenge);
3519 freebn(response);
3520 }
3521
3522 crWaitUntil(pktin);
3523 if (pktin->type == SSH1_SMSG_FAILURE) {
3524 if (flags & FLAG_VERBOSE)
3525 c_write_str(ssh, "Failed to authenticate with"
3526 " our public key.\r\n");
7b575324 3527 continue; /* go and try something else */
edd0cb8a 3528 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3529 bombout(("Bizarre response to RSA authentication response"));
3530 crStop(0);
3531 }
3532
3533 break; /* we're through! */
3534 }
3535
3536 }
3537
3538 /*
3539 * Otherwise, try various forms of password-like authentication.
3540 */
3541 s->cur_prompt = new_prompts(ssh->frontend);
32874aea 3542
86916870 3543 if (ssh->cfg.try_tis_auth &&
51470298 3544 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3545 !s->tis_auth_refused) {
3546 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
32874aea 3547 logevent("Requested TIS authentication");
51470298 3548 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
ff3187f6 3549 crWaitUntil(pktin);
3550 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
32874aea 3551 logevent("TIS authentication declined");
3552 if (flags & FLAG_INTERACTIVE)
51470298 3553 c_write_str(ssh, "TIS authentication refused.\r\n");
3554 s->tis_auth_refused = 1;
614a20a0 3555 continue;
32874aea 3556 } else {
0016d70b 3557 char *challenge;
3558 int challengelen;
edd0cb8a 3559 char *instr_suf, *prompt;
0016d70b 3560
ff3187f6 3561 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3562 if (!challenge) {
3563 bombout(("TIS challenge packet was badly formed"));
3564 crStop(0);
3565 }
32874aea 3566 logevent("Received TIS challenge");
edd0cb8a 3567 s->cur_prompt->to_server = TRUE;
3568 s->cur_prompt->name = dupstr("SSH TIS authentication");
614a20a0 3569 /* Prompt heuristic comes from OpenSSH */
edd0cb8a 3570 if (memchr(challenge, '\n', challengelen)) {
3571 instr_suf = dupstr("");
3572 prompt = dupprintf("%.*s", challengelen, challenge);
3573 } else {
3574 instr_suf = dupprintf("%.*s", challengelen, challenge);
3575 prompt = dupstr("Response: ");
3576 }
3577 s->cur_prompt->instruction =
3578 dupprintf("Using TIS authentication.%s%s",
3579 (*instr_suf) ? "\n" : "",
3580 instr_suf);
3581 s->cur_prompt->instr_reqd = TRUE;
3582 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3583 sfree(instr_suf);
32874aea 3584 }
3585 }
86916870 3586 if (ssh->cfg.try_tis_auth &&
51470298 3587 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3588 !s->ccard_auth_refused) {
3589 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
32874aea 3590 logevent("Requested CryptoCard authentication");
51470298 3591 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
ff3187f6 3592 crWaitUntil(pktin);
3593 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
32874aea 3594 logevent("CryptoCard authentication declined");
51470298 3595 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3596 s->ccard_auth_refused = 1;
614a20a0 3597 continue;
32874aea 3598 } else {
0016d70b 3599 char *challenge;
3600 int challengelen;
edd0cb8a 3601 char *instr_suf, *prompt;
0016d70b 3602
ff3187f6 3603 ssh_pkt_getstring(pktin, &challenge, &challengelen);
0016d70b 3604 if (!challenge) {
3605 bombout(("CryptoCard challenge packet was badly formed"));
3606 crStop(0);
3607 }
32874aea 3608 logevent("Received CryptoCard challenge");
edd0cb8a 3609 s->cur_prompt->to_server = TRUE;
3610 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3611 s->cur_prompt->name_reqd = FALSE;
3612 /* Prompt heuristic comes from OpenSSH */
3613 if (memchr(challenge, '\n', challengelen)) {
3614 instr_suf = dupstr("");
3615 prompt = dupprintf("%.*s", challengelen, challenge);
3616 } else {
3617 instr_suf = dupprintf("%.*s", challengelen, challenge);
3618 prompt = dupstr("Response: ");
3619 }
3620 s->cur_prompt->instruction =
3621 dupprintf("Using CryptoCard authentication.%s%s",
3622 (*instr_suf) ? "\n" : "",
3623 instr_suf);
3624 s->cur_prompt->instr_reqd = TRUE;
3625 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3626 sfree(instr_suf);
32874aea 3627 }
3628 }
51470298 3629 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
edd0cb8a 3630 s->cur_prompt->to_server = TRUE;
3631 s->cur_prompt->name = dupstr("SSH password");
3632 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3633 s->username, ssh->savedhost),
3634 FALSE, SSH_MAX_PASSWORD_LEN);
32874aea 3635 }
a52f067e 3636
614a20a0 3637 /*
3638 * Show password prompt, having first obtained it via a TIS
3639 * or CryptoCard exchange if we're doing TIS or CryptoCard
3640 * authentication.
3641 */
edd0cb8a 3642 {
3643 int ret; /* need not be kept over crReturn */
3644 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3645 while (ret < 0) {
3646 ssh->send_ok = 1;
3647 crWaitUntil(!pktin);
3648 ret = get_userpass_input(s->cur_prompt, in, inlen);
3649 ssh->send_ok = 0;
3650 }
3651 if (!ret) {
32874aea 3652 /*
edd0cb8a 3653 * Failed to get a password (for example
32874aea 3654 * because one was supplied on the command line
3655 * which has already failed to work). Terminate.
3656 */
edd0cb8a 3657 free_prompts(s->cur_prompt);
3658 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
3659 crStop(0);
32874aea 3660 }
32874aea 3661 }
3662
edd0cb8a 3663 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
32874aea 3664 /*
edd0cb8a 3665 * Defence against traffic analysis: we send a
3666 * whole bunch of packets containing strings of
3667 * different lengths. One of these strings is the
3668 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3669 * The others are all random data in
3670 * SSH1_MSG_IGNORE packets. This way a passive
3671 * listener can't tell which is the password, and
3672 * hence can't deduce the password length.
3673 *
3674 * Anybody with a password length greater than 16
3675 * bytes is going to have enough entropy in their
3676 * password that a listener won't find it _that_
3677 * much help to know how long it is. So what we'll
3678 * do is:
3679 *
3680 * - if password length < 16, we send 15 packets
3681 * containing string lengths 1 through 15
3682 *
3683 * - otherwise, we let N be the nearest multiple
3684 * of 8 below the password length, and send 8
3685 * packets containing string lengths N through
3686 * N+7. This won't obscure the order of
3687 * magnitude of the password length, but it will
3688 * introduce a bit of extra uncertainty.
3689 *
3690 * A few servers (the old 1.2.18 through 1.2.22)
3691 * can't deal with SSH1_MSG_IGNORE. For these
3692 * servers, we need an alternative defence. We make
3693 * use of the fact that the password is interpreted
3694 * as a C string: so we can append a NUL, then some
3695 * random data.
3696 *
3697 * One server (a Cisco one) can deal with neither
3698 * SSH1_MSG_IGNORE _nor_ a padded password string.
3699 * For this server we are left with no defences
3700 * against password length sniffing.
32874aea 3701 */
edd0cb8a 3702 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
32874aea 3703 /*
edd0cb8a 3704 * The server can deal with SSH1_MSG_IGNORE, so
3705 * we can use the primary defence.
32874aea 3706 */
edd0cb8a 3707 int bottom, top, pwlen, i;
3708 char *randomstr;
32874aea 3709
edd0cb8a 3710 pwlen = strlen(s->cur_prompt->prompts[0]->result);
3711 if (pwlen < 16) {
3712 bottom = 0; /* zero length passwords are OK! :-) */
3713 top = 15;
3714 } else {
3715 bottom = pwlen & ~7;
3716 top = bottom + 7;
3717 }
32874aea 3718
edd0cb8a 3719 assert(pwlen >= bottom && pwlen <= top);
32874aea 3720
edd0cb8a 3721 randomstr = snewn(top + 1, char);
32874aea 3722
edd0cb8a 3723 for (i = bottom; i <= top; i++) {
3724 if (i == pwlen) {
3725 defer_packet(ssh, s->pwpkt_type,
3726 PKTT_PASSWORD, PKT_STR,
3727 s->cur_prompt->prompts[0]->result,
3728 PKTT_OTHER, PKT_END);
3729 } else {
3730 for (j = 0; j < i; j++) {
3731 do {
3732 randomstr[j] = random_byte();
3733 } while (randomstr[j] == '\0');
32874aea 3734 }
edd0cb8a 3735 randomstr[i] = '\0';
3736 defer_packet(ssh, SSH1_MSG_IGNORE,
3737 PKT_STR, randomstr, PKT_END);
32874aea 3738 }
edd0cb8a 3739 }
3740 logevent("Sending password with camouflage packets");
3741 ssh_pkt_defersend(ssh);
3742 sfree(randomstr);
3743 }
3744 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3745 /*
3746 * The server can't deal with SSH1_MSG_IGNORE
3747 * but can deal with padded passwords, so we
3748 * can use the secondary defence.
3749 */
3750 char string[64];
3751 char *ss;
3752 int len;
3753
3754 len = strlen(s->cur_prompt->prompts[0]->result);
3755 if (len < sizeof(string)) {
3756 ss = string;
3757 strcpy(string, s->cur_prompt->prompts[0]->result);
3758 len++; /* cover the zero byte */
3759 while (len < sizeof(string)) {
3760 string[len++] = (char) random_byte();
bd358db1 3761 }
bd358db1 3762 } else {
edd0cb8a 3763 ss = s->cur_prompt->prompts[0]->result;
32874aea 3764 }
edd0cb8a 3765 logevent("Sending length-padded password");
9a10ecf4 3766 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
edd0cb8a 3767 PKT_INT, len, PKT_DATA, ss, len,
3768 PKTT_OTHER, PKT_END);
3769 } else {
3770 /*
3771 * The server has _both_
3772 * BUG_CHOKES_ON_SSH1_IGNORE and
3773 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3774 * therefore nothing we can do.
3775 */
3776 int len;
3777 len = strlen(s->cur_prompt->prompts[0]->result);
3778 logevent("Sending unpadded password");
3779 send_packet(ssh, s->pwpkt_type,
3780 PKTT_PASSWORD, PKT_INT, len,
3781 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
3782 PKTT_OTHER, PKT_END);
32874aea 3783 }
edd0cb8a 3784 } else {
3785 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3786 PKT_STR, s->cur_prompt->prompts[0]->result,
3787 PKTT_OTHER, PKT_END);
32874aea 3788 }
c5e9c988 3789 logevent("Sent password");
edd0cb8a 3790 free_prompts(s->cur_prompt);
ff3187f6 3791 crWaitUntil(pktin);
3792 if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 3793 if (flags & FLAG_VERBOSE)
51470298 3794 c_write_str(ssh, "Access denied\r\n");
c5e9c988 3795 logevent("Authentication refused");
ff3187f6 3796 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3797 bombout(("Strange packet received, type %d", pktin->type));
7ffdbc1a 3798 crStop(0);
374330e2 3799 }
3800 }
3801
edd0cb8a 3802 /* Clear up */
3803 if (s->publickey_blob) {
3804 sfree(s->publickey_blob);
3805 sfree(s->publickey_comment);
3806 }
3807
c5e9c988 3808 logevent("Authentication successful");
3809
fb09bf1c 3810 crFinish(1);
3811}
3812
32874aea 3813void sshfwd_close(struct ssh_channel *c)
3814{
51470298 3815 Ssh ssh = c->ssh;
3816
1ef619ae 3817 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 3818 return;
36f94d1f 3819
80e48603 3820 if (c && !c->closes) {
4ed34d25 3821 /*
64d6ff88 3822 * If halfopen is true, we have sent
4ed34d25 3823 * CHANNEL_OPEN for this channel, but it hasn't even been
3824 * acknowledged by the server. So we must set a close flag
3825 * on it now, and then when the server acks the channel
3826 * open, we can close it then.
3827 */
64d6ff88 3828 if (!c->halfopen) {
51470298 3829 if (ssh->version == 1) {
3830 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4ed34d25 3831 PKT_END);
3832 } else {
ff3187f6 3833 struct Packet *pktout;
3834 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3835 ssh2_pkt_adduint32(pktout, c->remoteid);
3836 ssh2_pkt_send(ssh, pktout);
4ed34d25 3837 }
32874aea 3838 }
0357890f 3839 c->closes = 1; /* sent MSG_CLOSE */
32874aea 3840 if (c->type == CHAN_X11) {
3841 c->u.x11.s = NULL;
d74d141c 3842 logevent("Forwarded X11 connection terminated");
4ed34d25 3843 } else if (c->type == CHAN_SOCKDATA ||
3844 c->type == CHAN_SOCKDATA_DORMANT) {
d74d141c 3845 c->u.pfd.s = NULL;
3846 logevent("Forwarded port closed");
32874aea 3847 }
3848 }
3849}
3850
5471d09a 3851int sshfwd_write(struct ssh_channel *c, char *buf, int len)
32874aea 3852{
51470298 3853 Ssh ssh = c->ssh;
3854
1ef619ae 3855 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 3856 return 0;
36f94d1f 3857
51470298 3858 if (ssh->version == 1) {
3859 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
32874aea 3860 PKT_INT, c->remoteid,
9a10ecf4 3861 PKTT_DATA,
3862 PKT_INT, len, PKT_DATA, buf, len,
3863 PKTT_OTHER, PKT_END);
5471d09a 3864 /*
2e85c969 3865 * In SSH-1 we can return 0 here - implying that forwarded
5471d09a 3866 * connections are never individually throttled - because
3867 * the only circumstance that can cause throttling will be
3868 * the whole SSH connection backing up, in which case
3869 * _everything_ will be throttled as a whole.
3870 */
3871 return 0;
783415f8 3872 } else {
32874aea 3873 ssh2_add_channel_data(c, buf, len);
5471d09a 3874 return ssh2_try_send(c);
3875 }
3876}
3877
3878void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3879{
51470298 3880 Ssh ssh = c->ssh;
3881
1ef619ae 3882 if (ssh->state == SSH_STATE_CLOSED)
36f94d1f 3883 return;
36f94d1f 3884
51470298 3885 if (ssh->version == 1) {
5471d09a 3886 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3887 c->v.v1.throttling = 0;
51470298 3888 ssh1_throttle(ssh, -1);
5471d09a 3889 }
3890 } else {
3891 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
783415f8 3892 }
9c964e85 3893}
3894
06fadff5 3895static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3896{
3897 struct queued_handler *qh = ssh->qhead;
3898
3899 assert(qh != NULL);
3900
3901 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3902
3903 if (qh->msg1 > 0) {
3904 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3905 ssh->packet_dispatch[qh->msg1] = NULL;
3906 }
3907 if (qh->msg2 > 0) {
3908 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3909 ssh->packet_dispatch[qh->msg2] = NULL;
3910 }
3911
3912 if (qh->next) {
3913 ssh->qhead = qh->next;
3914
3915 if (ssh->qhead->msg1 > 0) {
3916 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3917 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3918 }
3919 if (ssh->qhead->msg2 > 0) {
3920 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3921 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3922 }
3923 } else {
3924 ssh->qhead = ssh->qtail = NULL;
3925 ssh->packet_dispatch[pktin->type] = NULL;
3926 }
3927
3928 qh->handler(ssh, pktin, qh->ctx);
3929
3930 sfree(qh);
3931}
3932
3933static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3934 chandler_fn_t handler, void *ctx)
3935{
3936 struct queued_handler *qh;
3937
3938 qh = snew(struct queued_handler);
3939 qh->msg1 = msg1;
3940 qh->msg2 = msg2;
3941 qh->handler = handler;
3942 qh->ctx = ctx;
3943 qh->next = NULL;
3944
3945 if (ssh->qtail == NULL) {
3946 ssh->qhead = qh;
3947
3948 if (qh->msg1 > 0) {
3949 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3950 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3951 }
3952 if (qh->msg2 > 0) {
3953 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3954 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3955 }
3956 } else {
3957 ssh->qtail->next = qh;
3958 }
3959 ssh->qtail = qh;
3960}
3961
3962static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3963{
3964 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3965
3966 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3967 SSH2_MSG_REQUEST_SUCCESS)) {
3968 logeventf(ssh, "Remote port forwarding from %s enabled",
3969 pf->sportdesc);
3970 } else {
3971 logeventf(ssh, "Remote port forwarding from %s refused",
3972 pf->sportdesc);
3973
3974 rpf = del234(ssh->rportfwds, pf);
3975 assert(rpf == pf);
fda2feb1 3976 free_rportfwd(pf);
06fadff5 3977 }
3978}
3979
3980static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3981{
84328ddb 3982 const char *portfwd_strptr = cfg->portfwd;
3983 struct ssh_portfwd *epf;
3984 int i;
06fadff5 3985
fda2feb1 3986 if (!ssh->portfwds) {
3987 ssh->portfwds = newtree234(ssh_portcmp);
3988 } else {
3989 /*
3990 * Go through the existing port forwardings and tag them
84328ddb 3991 * with status==DESTROY. Any that we want to keep will be
3992 * re-enabled (status==KEEP) as we go through the
3993 * configuration and find out which bits are the same as
3994 * they were before.
fda2feb1 3995 */
3996 struct ssh_portfwd *epf;
3997 int i;
3998 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
84328ddb 3999 epf->status = DESTROY;
fda2feb1 4000 }
4001
06fadff5 4002 while (*portfwd_strptr) {
84328ddb 4003 char address_family, type;
4004 int sport,dport,sserv,dserv;
4005 char sports[256], dports[256], saddr[256], host[256];
4006 int n;
4007
05581745 4008 address_family = 'A';
4009 type = 'L';
84328ddb 4010 if (*portfwd_strptr == 'A' ||
4011 *portfwd_strptr == '4' ||
4012 *portfwd_strptr == '6')
4013 address_family = *portfwd_strptr++;
4014 if (*portfwd_strptr == 'L' ||
4015 *portfwd_strptr == 'R' ||
4016 *portfwd_strptr == 'D')
4017 type = *portfwd_strptr++;
05581745 4018
06fadff5 4019 saddr[0] = '\0';
05581745 4020
06fadff5 4021 n = 0;
4022 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4023 if (*portfwd_strptr == ':') {
4024 /*
4025 * We've seen a colon in the middle of the
4026 * source port number. This means that
4027 * everything we've seen until now is the
4028 * source _address_, so we'll move it into
4029 * saddr and start sports from the beginning
4030 * again.
4031 */
4032 portfwd_strptr++;
4033 sports[n] = '\0';
4034 if (ssh->version == 1 && type == 'R') {
2e85c969 4035 logeventf(ssh, "SSH-1 cannot handle remote source address "
06fadff5 4036 "spec \"%s\"; ignoring", sports);
4037 } else
4038 strcpy(saddr, sports);
4039 n = 0;
4040 }
019164b0 4041 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
06fadff5 4042 }
4043 sports[n] = 0;
4044 if (type != 'D') {
4045 if (*portfwd_strptr == '\t')
4046 portfwd_strptr++;
4047 n = 0;
4048 while (*portfwd_strptr && *portfwd_strptr != ':') {
019164b0 4049 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
06fadff5 4050 }
4051 host[n] = 0;
4052 if (*portfwd_strptr == ':')
4053 portfwd_strptr++;
4054 n = 0;
4055 while (*portfwd_strptr) {
019164b0 4056 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
06fadff5 4057 }
4058 dports[n] = 0;
4059 portfwd_strptr++;
4060 dport = atoi(dports);
4061 dserv = 0;
4062 if (dport == 0) {
4063 dserv = 1;
4064 dport = net_service_lookup(dports);
4065 if (!dport) {
4066 logeventf(ssh, "Service lookup failed for destination"
4067 " port \"%s\"", dports);
4068 }
4069 }
4070 } else {
4071 while (*portfwd_strptr) portfwd_strptr++;
a9e72926 4072 host[0] = 0;
4073 dports[0] = 0;
06fadff5 4074 dport = dserv = -1;
4075 portfwd_strptr++; /* eat the NUL and move to next one */
4076 }
4077 sport = atoi(sports);
4078 sserv = 0;
4079 if (sport == 0) {
4080 sserv = 1;
4081 sport = net_service_lookup(sports);
4082 if (!sport) {
4083 logeventf(ssh, "Service lookup failed for source"
4084 " port \"%s\"", sports);
4085 }
4086 }
4087 if (sport && dport) {
4088 /* Set up a description of the source port. */
fda2feb1 4089 struct ssh_portfwd *pfrec, *epfrec;
fda2feb1 4090
4091 pfrec = snew(struct ssh_portfwd);
4092 pfrec->type = type;
4093 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3fe92132 4094 pfrec->sserv = sserv ? dupstr(sports) : NULL;
fda2feb1 4095 pfrec->sport = sport;
84328ddb 4096 pfrec->daddr = *host ? dupstr(host) : NULL;
3fe92132 4097 pfrec->dserv = dserv ? dupstr(dports) : NULL;
fda2feb1 4098 pfrec->dport = dport;
4099 pfrec->local = NULL;
4100 pfrec->remote = NULL;
05581745 4101 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4102 address_family == '6' ? ADDRTYPE_IPV6 :
4103 ADDRTYPE_UNSPEC);
fda2feb1 4104
4105 epfrec = add234(ssh->portfwds, pfrec);
4106 if (epfrec != pfrec) {
4107 /*
4108 * We already have a port forwarding with precisely
4109 * these parameters. Hence, no need to do anything;
84328ddb 4110 * simply tag the existing one as KEEP.
fda2feb1 4111 */
84328ddb 4112 epfrec->status = KEEP;
fda2feb1 4113 free_portfwd(pfrec);
84328ddb 4114 } else {
4115 pfrec->status = CREATE;
4116 }
4117 }
4118 }
4119
4120 /*
4121 * Now go through and destroy any port forwardings which were
4122 * not re-enabled.
4123 */
4124 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4125 if (epf->status == DESTROY) {
4126 char *message;
4127
4128 message = dupprintf("%s port forwarding from %s%s%d",
4129 epf->type == 'L' ? "local" :
4130 epf->type == 'R' ? "remote" : "dynamic",
4131 epf->saddr ? epf->saddr : "",
4132 epf->saddr ? ":" : "",
4133 epf->sport);
4134
4135 if (epf->type != 'D') {
4136 char *msg2 = dupprintf("%s to %s:%d", message,
4137 epf->daddr, epf->dport);
4138 sfree(message);
4139 message = msg2;
4140 }
4141
4142 logeventf(ssh, "Cancelling %s", message);
4143 sfree(message);
4144
4145 if (epf->remote) {
4146 struct ssh_rportfwd *rpf = epf->remote;
4147 struct Packet *pktout;
4148
4149 /*
4150 * Cancel the port forwarding at the server
4151 * end.
4152 */
4153 if (ssh->version == 1) {
4154 /*
4155 * We cannot cancel listening ports on the
2e85c969 4156 * server side in SSH-1! There's no message
84328ddb 4157 * to support it. Instead, we simply remove
4158 * the rportfwd record from the local end
4159 * so that any connections the server tries
4160 * to make on it are rejected.
4161 */
4162 } else {
4163 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4164 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4165 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4166 if (epf->saddr) {
4167 ssh2_pkt_addstring(pktout, epf->saddr);
4168 } else if (ssh->cfg.rport_acceptall) {
5188540b 4169 /* XXX: ssh->cfg.rport_acceptall may not represent
4170 * what was used to open the original connection,
4171 * since it's reconfigurable. */
84328ddb 4172 ssh2_pkt_addstring(pktout, "0.0.0.0");
4173 } else {
4174 ssh2_pkt_addstring(pktout, "127.0.0.1");
4175 }
4176 ssh2_pkt_adduint32(pktout, epf->sport);
4177 ssh2_pkt_send(ssh, pktout);
4178 }
4179
4180 del234(ssh->rportfwds, rpf);
4181 free_rportfwd(rpf);
4182 } else if (epf->local) {
4183 pfd_terminate(epf->local);
4184 }
4185
4186 delpos234(ssh->portfwds, i);
4187 free_portfwd(epf);
4188 i--; /* so we don't skip one in the list */
4189 }
4190
4191 /*
4192 * And finally, set up any new port forwardings (status==CREATE).
4193 */
4194 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4195 if (epf->status == CREATE) {
4196 char *sportdesc, *dportdesc;
3fe92132 4197 sportdesc = dupprintf("%s%s%s%s%d%s",
84328ddb 4198 epf->saddr ? epf->saddr : "",
4199 epf->saddr ? ":" : "",
3fe92132 4200 epf->sserv ? epf->sserv : "",
4201 epf->sserv ? "(" : "",
4202 epf->sport,
4203 epf->sserv ? ")" : "");
84328ddb 4204 if (epf->type == 'D') {
4205 dportdesc = NULL;
4206 } else {
3fe92132 4207 dportdesc = dupprintf("%s:%s%s%d%s",
4208 epf->daddr,
4209 epf->dserv ? epf->dserv : "",
4210 epf->dserv ? "(" : "",
4211 epf->dport,
4212 epf->dserv ? ")" : "");
84328ddb 4213 }
05581745 4214
84328ddb 4215 if (epf->type == 'L') {
4216 const char *err = pfd_addforward(epf->daddr, epf->dport,
4217 epf->saddr, epf->sport,
5188540b 4218 ssh, cfg,
84328ddb 4219 &epf->local,
4220 epf->addressfamily);
4221
4222 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4223 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4224 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4225 sportdesc, dportdesc,
4226 err ? " failed: " : "", err ? err : "");
4227 } else if (epf->type == 'D') {
06fadff5 4228 const char *err = pfd_addforward(NULL, -1,
84328ddb 4229 epf->saddr, epf->sport,
5188540b 4230 ssh, cfg,
84328ddb 4231 &epf->local,
4232 epf->addressfamily);
4233
4234 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4235 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4236 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4237 sportdesc,
4238 err ? " failed: " : "", err ? err : "");
06fadff5 4239 } else {
4240 struct ssh_rportfwd *pf;
4241
4242 /*
4243 * Ensure the remote port forwardings tree exists.
4244 */
4245 if (!ssh->rportfwds) {
4246 if (ssh->version == 1)
4247 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4248 else
4249 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4250 }
4251
4252 pf = snew(struct ssh_rportfwd);
84328ddb 4253 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4254 pf->dhost[lenof(pf->dhost)-1] = '\0';
4255 pf->dport = epf->dport;
4256 pf->sport = epf->sport;
06fadff5 4257 if (add234(ssh->rportfwds, pf) != pf) {
4258 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
84328ddb 4259 epf->daddr, epf->dport);
06fadff5 4260 sfree(pf);
4261 } else {
4262 logeventf(ssh, "Requesting remote port %s"
84328ddb 4263 " forward to %s", sportdesc, dportdesc);
06fadff5 4264
4265 pf->sportdesc = sportdesc;
4266 sportdesc = NULL;
84328ddb 4267 epf->remote = pf;
4268 pf->pfrec = epf;
06fadff5 4269
4270 if (ssh->version == 1) {
4271 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
84328ddb 4272 PKT_INT, epf->sport,
4273 PKT_STR, epf->daddr,
4274 PKT_INT, epf->dport,
06fadff5 4275 PKT_END);
4276 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4277 SSH1_SMSG_FAILURE,
4278 ssh_rportfwd_succfail, pf);
4279 } else {
4280 struct Packet *pktout;
4281 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4282 ssh2_pkt_addstring(pktout, "tcpip-forward");
4283 ssh2_pkt_addbool(pktout, 1);/* want reply */
84328ddb 4284 if (epf->saddr) {
4285 ssh2_pkt_addstring(pktout, epf->saddr);
5188540b 4286 } else if (cfg->rport_acceptall) {
06fadff5 4287 ssh2_pkt_addstring(pktout, "0.0.0.0");
4288 } else {
4289 ssh2_pkt_addstring(pktout, "127.0.0.1");
4290 }
84328ddb 4291 ssh2_pkt_adduint32(pktout, epf->sport);
06fadff5 4292 ssh2_pkt_send(ssh, pktout);
4293
4294 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4295 SSH2_MSG_REQUEST_FAILURE,
4296 ssh_rportfwd_succfail, pf);
4297 }
4298 }
4299 }
4300 sfree(sportdesc);
84328ddb 4301 sfree(dportdesc);
06fadff5 4302 }
06fadff5 4303}
4304
51df0ab5 4305static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4306{
4307 char *string;
4308 int stringlen, bufsize;
4309
4310 ssh_pkt_getstring(pktin, &string, &stringlen);
4311 if (string == NULL) {
4312 bombout(("Incoming terminal data packet was badly formed"));
4313 return;
4314 }
4315
4316 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4317 string, stringlen);
4318 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4319 ssh->v1_stdout_throttling = 1;
4320 ssh1_throttle(ssh, +1);
4321 }
4322}
4323
4324static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4325{
4326 /* Remote side is trying to open a channel to talk to our
4327 * X-Server. Give them back a local channel number. */
4328 struct ssh_channel *c;
4329 int remoteid = ssh_pkt_getuint32(pktin);
4330
4331 logevent("Received X11 connect request");
4332 /* Refuse if X11 forwarding is disabled. */
4333 if (!ssh->X11_fwd_enabled) {
4334 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4335 PKT_INT, remoteid, PKT_END);
4336 logevent("Rejected X11 connect request");
4337 } else {
4338 c = snew(struct ssh_channel);
4339 c->ssh = ssh;
4340
4341 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4342 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4343 logevent("Opening X11 forward connection failed");
4344 sfree(c);
4345 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4346 PKT_INT, remoteid, PKT_END);
4347 } else {
4348 logevent
4349 ("Opening X11 forward connection succeeded");
4350 c->remoteid = remoteid;
64d6ff88 4351 c->halfopen = FALSE;
51df0ab5 4352 c->localid = alloc_channel_id(ssh);
4353 c->closes = 0;
4354 c->v.v1.throttling = 0;
4355 c->type = CHAN_X11; /* identify channel type */
4356 add234(ssh->channels, c);
4357 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4358 PKT_INT, c->remoteid, PKT_INT,
4359 c->localid, PKT_END);
4360 logevent("Opened X11 forward channel");
4361 }
4362 }
4363}
4364
4365static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4366{
4367 /* Remote side is trying to open a channel to talk to our
4368 * agent. Give them back a local channel number. */
4369 struct ssh_channel *c;
4370 int remoteid = ssh_pkt_getuint32(pktin);
4371
4372 /* Refuse if agent forwarding is disabled. */
4373 if (!ssh->agentfwd_enabled) {
4374 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4375 PKT_INT, remoteid, PKT_END);
4376 } else {
4377 c = snew(struct ssh_channel);
4378 c->ssh = ssh;
4379 c->remoteid = remoteid;
64d6ff88 4380 c->halfopen = FALSE;
51df0ab5 4381 c->localid = alloc_channel_id(ssh);
4382 c->closes = 0;
4383 c->v.v1.throttling = 0;
4384 c->type = CHAN_AGENT; /* identify channel type */
4385 c->u.a.lensofar = 0;
4386 add234(ssh->channels, c);
4387 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4388 PKT_INT, c->remoteid, PKT_INT, c->localid,
4389 PKT_END);
4390 }
4391}
4392
4393static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4394{
4395 /* Remote side is trying to open a channel to talk to a
4396 * forwarded port. Give them back a local channel number. */
4397 struct ssh_channel *c;
05581745 4398 struct ssh_rportfwd pf, *pfp;
51df0ab5 4399 int remoteid;
4400 int hostsize, port;
fb983202 4401 char *host;
51df0ab5 4402 const char *e;
4403 c = snew(struct ssh_channel);
4404 c->ssh = ssh;
4405
4406 remoteid = ssh_pkt_getuint32(pktin);
4407 ssh_pkt_getstring(pktin, &host, &hostsize);
4408 port = ssh_pkt_getuint32(pktin);
4409
4410 if (hostsize >= lenof(pf.dhost))
4411 hostsize = lenof(pf.dhost)-1;
4412 memcpy(pf.dhost, host, hostsize);
4413 pf.dhost[hostsize] = '\0';
4414 pf.dport = port;
05581745 4415 pfp = find234(ssh->rportfwds, &pf, NULL);
51df0ab5 4416
05581745 4417 if (pfp == NULL) {
fb983202 4418 logeventf(ssh, "Rejected remote port open request for %s:%d",
4419 pf.dhost, port);
51df0ab5 4420 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4421 PKT_INT, remoteid, PKT_END);
4422 } else {
fb983202 4423 logeventf(ssh, "Received remote port open request for %s:%d",
4424 pf.dhost, port);
51df0ab5 4425 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
05581745 4426 c, &ssh->cfg, pfp->pfrec->addressfamily);
51df0ab5 4427 if (e != NULL) {
fb983202 4428 logeventf(ssh, "Port open failed: %s", e);
51df0ab5 4429 sfree(c);
4430 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4431 PKT_INT, remoteid, PKT_END);
4432 } else {
4433 c->remoteid = remoteid;
64d6ff88 4434 c->halfopen = FALSE;
51df0ab5 4435 c->localid = alloc_channel_id(ssh);
4436 c->closes = 0;
4437 c->v.v1.throttling = 0;
4438 c->type = CHAN_SOCKDATA; /* identify channel type */
4439 add234(ssh->channels, c);
4440 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4441 PKT_INT, c->remoteid, PKT_INT,
4442 c->localid, PKT_END);
4443 logevent("Forwarded port opened successfully");
4444 }
4445 }
4446}
4447
4448static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4449{
4450 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4451 unsigned int localid = ssh_pkt_getuint32(pktin);
4452 struct ssh_channel *c;
4453
4454 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4455 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4456 c->remoteid = localid;
64d6ff88 4457 c->halfopen = FALSE;
51df0ab5 4458 c->type = CHAN_SOCKDATA;
4459 c->v.v1.throttling = 0;
4460 pfd_confirm(c->u.pfd.s);
4461 }
4462
4463 if (c && c->closes) {
4464 /*
4465 * We have a pending close on this channel,
4466 * which we decided on before the server acked
4467 * the channel open. So now we know the
4468 * remoteid, we can close it again.
4469 */
4470 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4471 PKT_INT, c->remoteid, PKT_END);
4472 }
4473}
4474
4475static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4476{
4477 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4478 struct ssh_channel *c;
4479
4480 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4481 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4482 logevent("Forwarded connection refused by server");
4483 pfd_close(c->u.pfd.s);
4484 del234(ssh->channels, c);
4485 sfree(c);
4486 }
4487}
4488
4489static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4490{
4491 /* Remote side closes a channel. */
4492 unsigned i = ssh_pkt_getuint32(pktin);
4493 struct ssh_channel *c;
4494 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 4495 if (c && !c->halfopen) {
51df0ab5 4496 int closetype;
4497 closetype =
4498 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4499
4500 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4501 logevent("Forwarded X11 connection terminated");
4502 assert(c->u.x11.s != NULL);
4503 x11_close(c->u.x11.s);
4504 c->u.x11.s = NULL;
4505 }
4506 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4507 logevent("Forwarded port closed");
4508 assert(c->u.pfd.s != NULL);
4509 pfd_close(c->u.pfd.s);
4510 c->u.pfd.s = NULL;
4511 }
4512
4513 c->closes |= (closetype << 2); /* seen this message */
4514 if (!(c->closes & closetype)) {
4515 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4516 PKT_END);
4517 c->closes |= closetype; /* sent it too */
4518 }
4519
4520 if (c->closes == 15) {
4521 del234(ssh->channels, c);
4522 sfree(c);
4523 }
4524 } else {
4525 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4526 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4527 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4528 i));
4529 }
4530}
4531
4532static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4533{
4534 /* Data sent down one of our channels. */
4535 int i = ssh_pkt_getuint32(pktin);
4536 char *p;
6d44acc9 4537 int len;
51df0ab5 4538 struct ssh_channel *c;
4539
4540 ssh_pkt_getstring(pktin, &p, &len);
4541
4542 c = find234(ssh->channels, &i, ssh_channelfind);
4543 if (c) {
4544 int bufsize = 0;
4545 switch (c->type) {
4546 case CHAN_X11:
4547 bufsize = x11_send(c->u.x11.s, p, len);
4548 break;
4549 case CHAN_SOCKDATA:
4550 bufsize = pfd_send(c->u.pfd.s, p, len);
4551 break;
4552 case CHAN_AGENT:
4553 /* Data for an agent message. Buffer it. */
4554 while (len > 0) {
4555 if (c->u.a.lensofar < 4) {
aa63ab7e 4556 unsigned int l = min(4 - c->u.a.lensofar, len);
51df0ab5 4557 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4558 l);
4559 p += l;
4560 len -= l;
4561 c->u.a.lensofar += l;
4562 }
4563 if (c->u.a.lensofar == 4) {
4564 c->u.a.totallen =
4565 4 + GET_32BIT(c->u.a.msglen);
4566 c->u.a.message = snewn(c->u.a.totallen,
4567 unsigned char);
4568 memcpy(c->u.a.message, c->u.a.msglen, 4);
4569 }
4570 if (c->u.a.lensofar >= 4 && len > 0) {
aa63ab7e 4571 unsigned int l =
51df0ab5 4572 min(c->u.a.totallen - c->u.a.lensofar,
4573 len);
4574 memcpy(c->u.a.message + c->u.a.lensofar, p,
4575 l);
4576 p += l;
4577 len -= l;
4578 c->u.a.lensofar += l;
4579 }
4580 if (c->u.a.lensofar == c->u.a.totallen) {
4581 void *reply;
4582 int replylen;
4583 if (agent_query(c->u.a.message,
4584 c->u.a.totallen,
4585 &reply, &replylen,
4586 ssh_agentf_callback, c))
4587 ssh_agentf_callback(c, reply, replylen);
4588 sfree(c->u.a.message);
4589 c->u.a.lensofar = 0;
4590 }
4591 }
4592 bufsize = 0; /* agent channels never back up */
4593 break;
4594 }
4595 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4596 c->v.v1.throttling = 1;
4597 ssh1_throttle(ssh, +1);
4598 }
4599 }
4600}
4601
4602static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4603{
51df0ab5 4604 ssh->exitcode = ssh_pkt_getuint32(pktin);
fb983202 4605 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
51df0ab5 4606 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4607 /*
4608 * In case `helpful' firewalls or proxies tack
4609 * extra human-readable text on the end of the
4610 * session which we might mistake for another
4611 * encrypted packet, we close the session once
4612 * we've sent EXIT_CONFIRMATION.
4613 */
9e296bfa 4614 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
51df0ab5 4615}
4616
c6ccd5c2 4617/* Helper function to deal with sending tty modes for REQUEST_PTY */
4618static void ssh1_send_ttymode(void *data, char *mode, char *val)
4619{
4620 struct Packet *pktout = (struct Packet *)data;
4621 int i = 0;
4622 unsigned int arg = 0;
4623 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4624 if (i == lenof(ssh_ttymodes)) return;
4625 switch (ssh_ttymodes[i].type) {
4626 case TTY_OP_CHAR:
4627 arg = ssh_tty_parse_specchar(val);
4628 break;
4629 case TTY_OP_BOOL:
4630 arg = ssh_tty_parse_boolean(val);
4631 break;
4632 }
4633 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4634 ssh2_pkt_addbyte(pktout, arg);
4635}
4636
4637
b09eaa88 4638static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4639 struct Packet *pktin)
32874aea 4640{
b09eaa88 4641 crBegin(ssh->do_ssh1_connection_crstate);
fb09bf1c 4642
51df0ab5 4643 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4644 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4645 ssh1_smsg_stdout_stderr_data;
4646
4647 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4648 ssh1_msg_channel_open_confirmation;
4649 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4650 ssh1_msg_channel_open_failure;
4651 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4652 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4653 ssh1_msg_channel_close;
4654 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4655 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4656
86916870 4657 if (ssh->cfg.agentfwd && agent_exists()) {
32874aea 4658 logevent("Requesting agent forwarding");
51470298 4659 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
32874aea 4660 do {
4661 crReturnV;
ff3187f6 4662 } while (!pktin);
4663 if (pktin->type != SSH1_SMSG_SUCCESS
4664 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4665 bombout(("Protocol confusion"));
7ffdbc1a 4666 crStopV;
ff3187f6 4667 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4668 logevent("Agent forwarding refused");
4669 } else {
4670 logevent("Agent forwarding enabled");
51470298 4671 ssh->agentfwd_enabled = TRUE;
51df0ab5 4672 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
db7d555c 4673 }
dacbd0e8 4674 }
4675
86916870 4676 if (ssh->cfg.x11_forward) {
32874aea 4677 char proto[20], data[64];
4678 logevent("Requesting X11 forwarding");
302121de 4679 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 4680 data, sizeof(data), ssh->cfg.x11_auth);
4681 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
f68353be 4682 /*
4683 * Note that while we blank the X authentication data here, we don't
4684 * take any special action to blank the start of an X11 channel,
4685 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4686 * without having session blanking enabled is likely to leak your
4687 * cookie into the log.
4688 */
51470298 4689 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4690 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
f68353be 4691 PKT_STR, proto,
4692 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
86916870 4693 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
421d6835 4694 PKT_END);
32874aea 4695 } else {
51470298 4696 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
f68353be 4697 PKT_STR, proto,
4698 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
32874aea 4699 }
4700 do {
4701 crReturnV;
ff3187f6 4702 } while (!pktin);
4703 if (pktin->type != SSH1_SMSG_SUCCESS
4704 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4705 bombout(("Protocol confusion"));
7ffdbc1a 4706 crStopV;
ff3187f6 4707 } else if (pktin->type == SSH1_SMSG_FAILURE) {
32874aea 4708 logevent("X11 forwarding refused");
4709 } else {
4710 logevent("X11 forwarding enabled");
51470298 4711 ssh->X11_fwd_enabled = TRUE;
51df0ab5 4712 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
9c964e85 4713 }
4714 }
4715
06fadff5 4716 ssh_setup_portfwd(ssh, &ssh->cfg);
4717 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
d74d141c 4718
86916870 4719 if (!ssh->cfg.nopty) {
c6ccd5c2 4720 struct Packet *pkt;
a5dd8467 4721 /* Unpick the terminal-speed string. */
4722 /* XXX perhaps we should allow no speeds to be sent. */
db219738 4723 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4724 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 4725 /* Send the pty request. */
c6ccd5c2 4726 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4727 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4728 ssh_pkt_adduint32(pkt, ssh->term_height);
4729 ssh_pkt_adduint32(pkt, ssh->term_width);
4730 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4731 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4732 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4733 ssh1_send_ttymode, (void *)pkt);
4734 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4735 ssh_pkt_adduint32(pkt, ssh->ispeed);
4736 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4737 ssh_pkt_adduint32(pkt, ssh->ospeed);
4738 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4739 s_wrpkt(ssh, pkt);
51470298 4740 ssh->state = SSH_STATE_INTERMED;
32874aea 4741 do {
4742 crReturnV;
ff3187f6 4743 } while (!pktin);
4744 if (pktin->type != SSH1_SMSG_SUCCESS
4745 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4746 bombout(("Protocol confusion"));
7ffdbc1a 4747 crStopV;
ff3187f6 4748 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4749 c_write_str(ssh, "Server refused to allocate pty\r\n");
4750 ssh->editing = ssh->echoing = 1;
32874aea 4751 }
a5dd8467 4752 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 4753 ssh->ospeed, ssh->ispeed);
0965bee0 4754 } else {
51470298 4755 ssh->editing = ssh->echoing = 1;
374330e2 4756 }
4757
86916870 4758 if (ssh->cfg.compression) {
51470298 4759 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
32874aea 4760 do {
4761 crReturnV;
ff3187f6 4762 } while (!pktin);
4763 if (pktin->type != SSH1_SMSG_SUCCESS
4764 && pktin->type != SSH1_SMSG_FAILURE) {
6b5cf8b4 4765 bombout(("Protocol confusion"));
7ffdbc1a 4766 crStopV;
ff3187f6 4767 } else if (pktin->type == SSH1_SMSG_FAILURE) {
51470298 4768 c_write_str(ssh, "Server refused to compress\r\n");
32874aea 4769 }
4ba9b64b 4770 logevent("Started compression");
51470298 4771 ssh->v1_compressing = TRUE;
5366aed8 4772 ssh->cs_comp_ctx = zlib_compress_init();
4773 logevent("Initialised zlib (RFC1950) compression");
4774 ssh->sc_comp_ctx = zlib_decompress_init();
4775 logevent("Initialised zlib (RFC1950) decompression");
4ba9b64b 4776 }
4777
fd5e5847 4778 /*
4779 * Start the shell or command.
4780 *
2e85c969 4781 * Special case: if the first-choice command is an SSH-2
fd5e5847 4782 * subsystem (hence not usable here) and the second choice
4783 * exists, we fall straight back to that.
4784 */
4785 {
86916870 4786 char *cmd = ssh->cfg.remote_cmd_ptr;
04c52f10 4787
4788 if (!cmd) cmd = ssh->cfg.remote_cmd;
fd5e5847 4789
86916870 4790 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4791 cmd = ssh->cfg.remote_cmd_ptr2;
51470298 4792 ssh->fallback_cmd = TRUE;
fd5e5847 4793 }
4794 if (*cmd)
51470298 4795 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
fd5e5847 4796 else
51470298 4797 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
fd5e5847 4798 logevent("Started session");
4799 }
374330e2 4800
51470298 4801 ssh->state = SSH_STATE_SESSION;
4802 if (ssh->size_needed)
4803 ssh_size(ssh, ssh->term_width, ssh->term_height);
4804 if (ssh->eof_needed)
4805 ssh_special(ssh, TS_EOF);
374330e2 4806
b9d7bcad 4807 if (ssh->ldisc)
4808 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
51470298 4809 ssh->send_ok = 1;
4810 ssh->channels = newtree234(ssh_channelcmp);
374330e2 4811 while (1) {
d74d141c 4812
51df0ab5 4813 /*
4814 * By this point, most incoming packets are already being
4815 * handled by the dispatch table, and we need only pay
4816 * attention to the unusual ones.
4817 */
0357890f 4818
51df0ab5 4819 crReturnV;
4820 if (pktin) {
4821 if (pktin->type == SSH1_SMSG_SUCCESS) {
972a41c8 4822 /* may be from EXEC_SHELL on some servers */
ff3187f6 4823 } else if (pktin->type == SSH1_SMSG_FAILURE) {
972a41c8 4824 /* may be from EXEC_SHELL on some servers
374330e2 4825 * if no pty is available or in other odd cases. Ignore */
374330e2 4826 } else {
ff3187f6 4827 bombout(("Strange packet received: type %d", pktin->type));
7ffdbc1a 4828 crStopV;
374330e2 4829 }
4830 } else {
8df7a775 4831 while (inlen > 0) {
4832 int len = min(inlen, 512);
9a10ecf4 4833 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4834 PKT_INT, len, PKT_DATA, in, len,
4835 PKTT_OTHER, PKT_END);
8df7a775 4836 in += len;
4837 inlen -= len;
4838 }
374330e2 4839 }
4840 }
4841
4842 crFinishV;
4843}
4844
4845/*
2e85c969 4846 * Handle the top-level SSH-2 protocol.
b09eaa88 4847 */
4848static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4849{
fb983202 4850 char *msg;
b09eaa88 4851 int msglen;
4852
4853 ssh_pkt_getstring(pktin, &msg, &msglen);
fb983202 4854 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 4855}
4856
4857static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4858{
4859 /* log reason code in disconnect message */
4860 char *msg;
4861 int msglen;
4862
4863 ssh_pkt_getstring(pktin, &msg, &msglen);
4864 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4865}
4866
409bfa77 4867static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
b09eaa88 4868{
4869 /* Do nothing, because we're ignoring it! Duhh. */
4870}
4871
4872static void ssh1_protocol_setup(Ssh ssh)
4873{
4874 int i;
4875
4876 /*
4877 * Most messages are handled by the coroutines.
4878 */
4879 for (i = 0; i < 256; i++)
4880 ssh->packet_dispatch[i] = NULL;
4881
4882 /*
4883 * These special message types we install handlers for.
4884 */
4885 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4886 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4887 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4888}
4889
1c1a7262 4890static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
b09eaa88 4891 struct Packet *pktin)
4892{
1c1a7262 4893 unsigned char *in=(unsigned char*)vin;
b09eaa88 4894 if (ssh->state == SSH_STATE_CLOSED)
4895 return;
4896
4897 if (pktin && ssh->packet_dispatch[pktin->type]) {
4898 ssh->packet_dispatch[pktin->type](ssh, pktin);
4899 return;
4900 }
4901
4902 if (!ssh->protocol_initial_phase_done) {
4903 if (do_ssh1_login(ssh, in, inlen, pktin))
4904 ssh->protocol_initial_phase_done = TRUE;
4905 else
4906 return;
4907 }
4908
4909 do_ssh1_connection(ssh, in, inlen, pktin);
4910}
4911
4912/*
e5574168 4913 * Utility routine for decoding comma-separated strings in KEXINIT.
4914 */
32874aea 4915static int in_commasep_string(char *needle, char *haystack, int haylen)
4916{
57356d63 4917 int needlen;
4918 if (!needle || !haystack) /* protect against null pointers */
4919 return 0;
4920 needlen = strlen(needle);
e5574168 4921 while (1) {
32874aea 4922 /*
4923 * Is it at the start of the string?
4924 */
4925 if (haylen >= needlen && /* haystack is long enough */
4926 !memcmp(needle, haystack, needlen) && /* initial match */
4927 (haylen == needlen || haystack[needlen] == ',')
4928 /* either , or EOS follows */
4929 )
4930 return 1;
4931 /*
4932 * If not, search for the next comma and resume after that.
4933 * If no comma found, terminate.
4934 */
4935 while (haylen > 0 && *haystack != ',')
4936 haylen--, haystack++;
4937 if (haylen == 0)
4938 return 0;
4939 haylen--, haystack++; /* skip over comma itself */
e5574168 4940 }
4941}
4942
4943/*
b59743d5 4944 * Similar routine for checking whether we have the first string in a list.
4945 */
4946static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4947{
4948 int needlen;
4949 if (!needle || !haystack) /* protect against null pointers */
4950 return 0;
4951 needlen = strlen(needle);
4952 /*
4953 * Is it at the start of the string?
4954 */
4955 if (haylen >= needlen && /* haystack is long enough */
4956 !memcmp(needle, haystack, needlen) && /* initial match */
4957 (haylen == needlen || haystack[needlen] == ',')
4958 /* either , or EOS follows */
4959 )
4960 return 1;
4961 return 0;
4962}
4963
4964
4965/*
2e85c969 4966 * SSH-2 key creation method.
d39f364a 4967 */
b672f405 4968static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
d8baa528 4969 unsigned char *keyspace)
32874aea 4970{
b672f405 4971 const struct ssh_hash *h = ssh->kex->hash;
4972 void *s;
4973 /* First hlen bytes. */
4974 s = h->init();
51470298 4975 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 4976 hash_mpint(h, s, K);
4977 h->bytes(s, H, h->hlen);
4978 h->bytes(s, &chr, 1);
4979 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
4980 h->final(s, keyspace);
4981 /* Next hlen bytes. */
4982 s = h->init();
51470298 4983 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
b672f405 4984 hash_mpint(h, s, K);
4985 h->bytes(s, H, h->hlen);
4986 h->bytes(s, keyspace, h->hlen);
4987 h->final(s, keyspace + h->hlen);
d39f364a 4988}
4989
4990/*
2e85c969 4991 * Handle the SSH-2 transport layer.
e5574168 4992 */
1c1a7262 4993static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
ff3187f6 4994 struct Packet *pktin)
e5574168 4995{
1c1a7262 4996 unsigned char *in = (unsigned char *)vin;
51470298 4997 struct do_ssh2_transport_state {
4763c1c2 4998 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
51470298 4999 Bignum p, g, e, f, K;
3dc9a6a7 5000 void *our_kexinit;
5001 int our_kexinitlen;
51470298 5002 int kex_init_value, kex_reply_value;
5003 const struct ssh_mac **maclist;
5004 int nmacs;
5005 const struct ssh2_cipher *cscipher_tobe;
5006 const struct ssh2_cipher *sccipher_tobe;
5007 const struct ssh_mac *csmac_tobe;
5008 const struct ssh_mac *scmac_tobe;
5009 const struct ssh_compress *cscomp_tobe;
5010 const struct ssh_compress *sccomp_tobe;
5011 char *hostkeydata, *sigdata, *keystr, *fingerprint;
5012 int hostkeylen, siglen;
5013 void *hkey; /* actual host key */
2ccb2fc8 5014 unsigned char exchange_hash[32];
83e7d008 5015 int n_preferred_kex;
34557659 5016 const struct ssh_kexes *preferred_kex[KEX_MAX];
51470298 5017 int n_preferred_ciphers;
5018 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5019 const struct ssh_compress *preferred_comp;
e13bba36 5020 int got_session_id, activated_authconn;
ff3187f6 5021 struct Packet *pktout;
3d9449a1 5022 int dlgret;
5023 int guessok;
4763c1c2 5024 int ignorepkt;
51470298 5025 };
5026 crState(do_ssh2_transport_state);
5027
5028 crBegin(ssh->do_ssh2_transport_crstate);
5029
5030 s->cscipher_tobe = s->sccipher_tobe = NULL;
5031 s->csmac_tobe = s->scmac_tobe = NULL;
5032 s->cscomp_tobe = s->sccomp_tobe = NULL;
5033
e13bba36 5034 s->got_session_id = s->activated_authconn = FALSE;
e5574168 5035
e13bba36 5036 /*
5037 * Be prepared to work around the buggy MAC problem.
5038 */
5039 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5040 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5041 else
5042 s->maclist = macs, s->nmacs = lenof(macs);
5043
5044 begin_key_exchange:
149d2abc 5045 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
51470298 5046 {
e13bba36 5047 int i, j, commalist_started;
5048
51470298 5049 /*
83e7d008 5050 * Set up the preferred key exchange. (NULL => warn below here)
5051 */
5052 s->n_preferred_kex = 0;
5053 for (i = 0; i < KEX_MAX; i++) {
5054 switch (ssh->cfg.ssh_kexlist[i]) {
5055 case KEX_DHGEX:
5056 s->preferred_kex[s->n_preferred_kex++] =
5057 &ssh_diffiehellman_gex;
5058 break;
5059 case KEX_DHGROUP14:
5060 s->preferred_kex[s->n_preferred_kex++] =
5061 &ssh_diffiehellman_group14;
5062 break;
5063 case KEX_DHGROUP1:
5064 s->preferred_kex[s->n_preferred_kex++] =
5065 &ssh_diffiehellman_group1;
5066 break;
5067 case CIPHER_WARN:
5068 /* Flag for later. Don't bother if it's the last in
5069 * the list. */
5070 if (i < KEX_MAX - 1) {
5071 s->preferred_kex[s->n_preferred_kex++] = NULL;
5072 }
5073 break;
5074 }
5075 }
83e7d008 5076
83e7d008 5077 /*
51470298 5078 * Set up the preferred ciphers. (NULL => warn below here)
5079 */
5080 s->n_preferred_ciphers = 0;
5081 for (i = 0; i < CIPHER_MAX; i++) {
86916870 5082 switch (ssh->cfg.ssh_cipherlist[i]) {
51470298 5083 case CIPHER_BLOWFISH:
5084 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5085 break;
5086 case CIPHER_DES:
86916870 5087 if (ssh->cfg.ssh2_des_cbc) {
51470298 5088 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5089 }
5090 break;
5091 case CIPHER_3DES:
5092 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5093 break;
5094 case CIPHER_AES:
5095 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5096 break;
a2add208 5097 case CIPHER_ARCFOUR:
5098 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5099 break;
51470298 5100 case CIPHER_WARN:
5101 /* Flag for later. Don't bother if it's the last in
5102 * the list. */
5103 if (i < CIPHER_MAX - 1) {
5104 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5105 }
5106 break;
ca20bfcf 5107 }
ca20bfcf 5108 }
7591b9ff 5109
e13bba36 5110 /*
5111 * Set up preferred compression.
5112 */
5113 if (ssh->cfg.compression)
5114 s->preferred_comp = &ssh_zlib;
5115 else
5116 s->preferred_comp = &ssh_comp_none;
51470298 5117
5118 /*
590f6a5f 5119 * Enable queueing of outgoing auth- or connection-layer
5120 * packets while we are in the middle of a key exchange.
5121 */
5122 ssh->queueing = TRUE;
5123
5124 /*
9442dd57 5125 * Flag that KEX is in progress.
5126 */
5127 ssh->kex_in_progress = TRUE;
5128
5129 /*
51470298 5130 * Construct and send our key exchange packet.
5131 */
ff3187f6 5132 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
51470298 5133 for (i = 0; i < 16; i++)
ff3187f6 5134 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
51470298 5135 /* List key exchange algorithms. */
ff3187f6 5136 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5137 commalist_started = 0;
5138 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5139 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5140 if (!k) continue; /* warning flag */
34557659 5141 for (j = 0; j < k->nkexes; j++) {
5142 if (commalist_started)
5143 ssh2_pkt_addstring_str(s->pktout, ",");
5144 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5145 commalist_started = 1;
5146 }
32874aea 5147 }
51470298 5148 /* List server host key algorithms. */
ff3187f6 5149 ssh2_pkt_addstring_start(s->pktout);
51470298 5150 for (i = 0; i < lenof(hostkey_algs); i++) {
ff3187f6 5151 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
51470298 5152 if (i < lenof(hostkey_algs) - 1)
ff3187f6 5153 ssh2_pkt_addstring_str(s->pktout, ",");
32874aea 5154 }
51470298 5155 /* List client->server encryption algorithms. */
ff3187f6 5156 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5157 commalist_started = 0;
51470298 5158 for (i = 0; i < s->n_preferred_ciphers; i++) {
5159 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5160 if (!c) continue; /* warning flag */
5161 for (j = 0; j < c->nciphers; j++) {
83e7d008 5162 if (commalist_started)
ff3187f6 5163 ssh2_pkt_addstring_str(s->pktout, ",");
5164 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5165 commalist_started = 1;
51470298 5166 }
5167 }
5168 /* List server->client encryption algorithms. */
ff3187f6 5169 ssh2_pkt_addstring_start(s->pktout);
83e7d008 5170 commalist_started = 0;
51470298 5171 for (i = 0; i < s->n_preferred_ciphers; i++) {
5172 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5173 if (!c) continue; /* warning flag */
5174 for (j = 0; j < c->nciphers; j++) {
83e7d008 5175 if (commalist_started)
ff3187f6 5176 ssh2_pkt_addstring_str(s->pktout, ",");
5177 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
83e7d008 5178 commalist_started = 1;
51470298 5179 }
5180 }
5181 /* List client->server MAC algorithms. */
ff3187f6 5182 ssh2_pkt_addstring_start(s->pktout);
51470298 5183 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5184 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5185 if (i < s->nmacs - 1)
ff3187f6 5186 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5187 }
5188 /* List server->client MAC algorithms. */
ff3187f6 5189 ssh2_pkt_addstring_start(s->pktout);
51470298 5190 for (i = 0; i < s->nmacs; i++) {
ff3187f6 5191 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
51470298 5192 if (i < s->nmacs - 1)
ff3187f6 5193 ssh2_pkt_addstring_str(s->pktout, ",");
51470298 5194 }
5195 /* List client->server compression algorithms. */
ff3187f6 5196 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5197 assert(lenof(compressions) > 1);
ff3187f6 5198 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5199 for (i = 0; i < lenof(compressions); i++) {
5200 const struct ssh_compress *c = compressions[i];
5201 if (c != s->preferred_comp) {
ff3187f6 5202 ssh2_pkt_addstring_str(s->pktout, ",");
5203 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5204 }
51470298 5205 }
5206 /* List server->client compression algorithms. */
ff3187f6 5207 ssh2_pkt_addstring_start(s->pktout);
f6e0abe2 5208 assert(lenof(compressions) > 1);
ff3187f6 5209 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
f6e0abe2 5210 for (i = 0; i < lenof(compressions); i++) {
5211 const struct ssh_compress *c = compressions[i];
5212 if (c != s->preferred_comp) {
ff3187f6 5213 ssh2_pkt_addstring_str(s->pktout, ",");
5214 ssh2_pkt_addstring_str(s->pktout, c->name);
f6e0abe2 5215 }
51470298 5216 }
5217 /* List client->server languages. Empty list. */
ff3187f6 5218 ssh2_pkt_addstring_start(s->pktout);
51470298 5219 /* List server->client languages. Empty list. */
ff3187f6 5220 ssh2_pkt_addstring_start(s->pktout);
51470298 5221 /* First KEX packet does _not_ follow, because we're not that brave. */
ff3187f6 5222 ssh2_pkt_addbool(s->pktout, FALSE);
51470298 5223 /* Reserved. */
ff3187f6 5224 ssh2_pkt_adduint32(s->pktout, 0);
e5574168 5225 }
0db56f73 5226
3dc9a6a7 5227 s->our_kexinitlen = s->pktout->length - 5;
5228 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5229 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
0db56f73 5230
590f6a5f 5231 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5232
ff3187f6 5233 if (!pktin)
5234 crWaitUntil(pktin);
e5574168 5235
5236 /*
5237 * Now examine the other side's KEXINIT to see what we're up
5238 * to.
5239 */
51470298 5240 {
4763c1c2 5241 char *str, *preferred;
3d9449a1 5242 int i, j, len;
51470298 5243
ff3187f6 5244 if (pktin->type != SSH2_MSG_KEXINIT) {
6b5cf8b4 5245 bombout(("expected key exchange packet from server"));
7ffdbc1a 5246 crStop(0);
32874aea 5247 }
51470298 5248 ssh->kex = NULL;
5249 ssh->hostkey = NULL;
5250 s->cscipher_tobe = NULL;
5251 s->sccipher_tobe = NULL;
5252 s->csmac_tobe = NULL;
5253 s->scmac_tobe = NULL;
5254 s->cscomp_tobe = NULL;
5255 s->sccomp_tobe = NULL;
4763c1c2 5256 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5257
ff3187f6 5258 pktin->savedpos += 16; /* skip garbage cookie */
5259 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4763c1c2 5260
5261 preferred = NULL;
83e7d008 5262 for (i = 0; i < s->n_preferred_kex; i++) {
34557659 5263 const struct ssh_kexes *k = s->preferred_kex[i];
83e7d008 5264 if (!k) {
4763c1c2 5265 s->warn_kex = TRUE;
5266 } else {
34557659 5267 for (j = 0; j < k->nkexes; j++) {
5268 if (!preferred) preferred = k->list[j]->name;
5269 if (in_commasep_string(k->list[j]->name, str, len)) {
5270 ssh->kex = k->list[j];
5271 break;
5272 }
5273 }
83e7d008 5274 }
4763c1c2 5275 if (ssh->kex)
51470298 5276 break;
32874aea 5277 }
83e7d008 5278 if (!ssh->kex) {
5279 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5280 str ? str : "(null)"));
5281 crStop(0);
5282 }
b59743d5 5283 /*
5284 * Note that the server's guess is considered wrong if it doesn't match
5285 * the first algorithm in our list, even if it's still the algorithm
5286 * we end up using.
5287 */
4763c1c2 5288 s->guessok = first_in_commasep_string(preferred, str, len);
ff3187f6 5289 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
51470298 5290 for (i = 0; i < lenof(hostkey_algs); i++) {
5291 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5292 ssh->hostkey = hostkey_algs[i];
5293 break;
5294 }
5295 }
3d9449a1 5296 s->guessok = s->guessok &&
b59743d5 5297 first_in_commasep_string(hostkey_algs[0]->name, str, len);
ff3187f6 5298 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
51470298 5299 for (i = 0; i < s->n_preferred_ciphers; i++) {
5300 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5301 if (!c) {
4763c1c2 5302 s->warn_cscipher = TRUE;
51470298 5303 } else {
5304 for (j = 0; j < c->nciphers; j++) {
5305 if (in_commasep_string(c->list[j]->name, str, len)) {
5306 s->cscipher_tobe = c->list[j];
5307 break;
5308 }
ca20bfcf 5309 }
32874aea 5310 }
4763c1c2 5311 if (s->cscipher_tobe)
51470298 5312 break;
32874aea 5313 }
51470298 5314 if (!s->cscipher_tobe) {
6b5cf8b4 5315 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
57356d63 5316 str ? str : "(null)"));
7ffdbc1a 5317 crStop(0);
ca20bfcf 5318 }
0ef8f407 5319
ff3187f6 5320 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
51470298 5321 for (i = 0; i < s->n_preferred_ciphers; i++) {
5322 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5323 if (!c) {
4763c1c2 5324 s->warn_sccipher = TRUE;
51470298 5325 } else {
5326 for (j = 0; j < c->nciphers; j++) {
5327 if (in_commasep_string(c->list[j]->name, str, len)) {
5328 s->sccipher_tobe = c->list[j];
5329 break;
5330 }
ca20bfcf 5331 }
32874aea 5332 }
4763c1c2 5333 if (s->sccipher_tobe)
51470298 5334 break;
32874aea 5335 }
51470298 5336 if (!s->sccipher_tobe) {
6b5cf8b4 5337 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
57356d63 5338 str ? str : "(null)"));
7ffdbc1a 5339 crStop(0);
ca20bfcf 5340 }
0ef8f407 5341
ff3187f6 5342 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
51470298 5343 for (i = 0; i < s->nmacs; i++) {
5344 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5345 s->csmac_tobe = s->maclist[i];
5346 break;
5347 }
32874aea 5348 }
ff3187f6 5349 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
51470298 5350 for (i = 0; i < s->nmacs; i++) {
5351 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5352 s->scmac_tobe = s->maclist[i];
5353 break;
5354 }
32874aea 5355 }
ff3187f6 5356 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
51470298 5357 for (i = 0; i < lenof(compressions) + 1; i++) {
5358 const struct ssh_compress *c =
5359 i == 0 ? s->preferred_comp : compressions[i - 1];
5360 if (in_commasep_string(c->name, str, len)) {
5361 s->cscomp_tobe = c;
5362 break;
5363 }
32874aea 5364 }
ff3187f6 5365 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
51470298 5366 for (i = 0; i < lenof(compressions) + 1; i++) {
5367 const struct ssh_compress *c =
5368 i == 0 ? s->preferred_comp : compressions[i - 1];
5369 if (in_commasep_string(c->name, str, len)) {
5370 s->sccomp_tobe = c;
5371 break;
5372 }
32874aea 5373 }
b59743d5 5374 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5375 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
4763c1c2 5376 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5377
5378 if (s->warn_kex) {
5379 ssh_set_frozen(ssh, 1);
5380 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5381 ssh->kex->name,
5382 ssh_dialog_callback, ssh);
5383 if (s->dlgret < 0) {
5384 do {
5385 crReturn(0);
5386 if (pktin) {
5387 bombout(("Unexpected data from server while"
5388 " waiting for user response"));
5389 crStop(0);
5390 }
5391 } while (pktin || inlen > 0);
5392 s->dlgret = ssh->user_response;
5393 }
5394 ssh_set_frozen(ssh, 0);
5395 if (s->dlgret == 0) {
9e296bfa 5396 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5397 0, TRUE);
a5a6f839 5398 crStop(0);
4763c1c2 5399 }
5400 }
5401
5402 if (s->warn_cscipher) {
5403 ssh_set_frozen(ssh, 1);
5404 s->dlgret = askalg(ssh->frontend,
5405 "client-to-server cipher",
5406 s->cscipher_tobe->name,
5407 ssh_dialog_callback, ssh);
5408 if (s->dlgret < 0) {
5409 do {
5410 crReturn(0);
5411 if (pktin) {
5412 bombout(("Unexpected data from server while"
5413 " waiting for user response"));
5414 crStop(0);
5415 }
5416 } while (pktin || inlen > 0);
5417 s->dlgret = ssh->user_response;
5418 }
5419 ssh_set_frozen(ssh, 0);
5420 if (s->dlgret == 0) {
9e296bfa 5421 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5422 0, TRUE);
a5a6f839 5423 crStop(0);
4763c1c2 5424 }
5425 }
5426
5427 if (s->warn_sccipher) {
5428 ssh_set_frozen(ssh, 1);
5429 s->dlgret = askalg(ssh->frontend,
5430 "server-to-client cipher",
5431 s->sccipher_tobe->name,
5432 ssh_dialog_callback, ssh);
5433 if (s->dlgret < 0) {
5434 do {
5435 crReturn(0);
5436 if (pktin) {
5437 bombout(("Unexpected data from server while"
5438 " waiting for user response"));
5439 crStop(0);
5440 }
5441 } while (pktin || inlen > 0);
5442 s->dlgret = ssh->user_response;
5443 }
5444 ssh_set_frozen(ssh, 0);
5445 if (s->dlgret == 0) {
9e296bfa 5446 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5447 0, TRUE);
a5a6f839 5448 crStop(0);
4763c1c2 5449 }
5450 }
5451
b672f405 5452 ssh->exhash = ssh->kex->hash->init();
5453 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5454 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5455 hash_string(ssh->kex->hash, ssh->exhash,
5456 s->our_kexinit, s->our_kexinitlen);
3dc9a6a7 5457 sfree(s->our_kexinit);
5458 if (pktin->length > 5)
b672f405 5459 hash_string(ssh->kex->hash, ssh->exhash,
5460 pktin->data + 5, pktin->length - 5);
3dc9a6a7 5461
4763c1c2 5462 if (s->ignorepkt) /* first_kex_packet_follows */
b59743d5 5463 crWaitUntil(pktin); /* Ignore packet */
e5574168 5464 }
e5574168 5465
5466 /*
7bd5a860 5467 * Work out the number of bits of key we will need from the key
5468 * exchange. We start with the maximum key length of either
5469 * cipher...
5470 */
5471 {
32874aea 5472 int csbits, scbits;
7bd5a860 5473
51470298 5474 csbits = s->cscipher_tobe->keylen;
5475 scbits = s->sccipher_tobe->keylen;
5476 s->nbits = (csbits > scbits ? csbits : scbits);
7bd5a860 5477 }
b672f405 5478 /* The keys only have hlen-bit entropy, since they're based on
5479 * a hash. So cap the key size at hlen bits. */
5480 if (s->nbits > ssh->kex->hash->hlen * 8)
5481 s->nbits = ssh->kex->hash->hlen * 8;
7bd5a860 5482
5483 /*
a92dd380 5484 * If we're doing Diffie-Hellman group exchange, start by
5485 * requesting a group.
e5574168 5486 */
d1aaf71d 5487 if (!ssh->kex->pdata) {
32874aea 5488 logevent("Doing Diffie-Hellman group exchange");
51470298 5489 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
32874aea 5490 /*
5491 * Work out how big a DH group we will need to allow that
5492 * much data.
7bd5a860 5493 */
51470298 5494 s->pbits = 512 << ((s->nbits - 1) / 64);
ff3187f6 5495 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5496 ssh2_pkt_adduint32(s->pktout, s->pbits);
590f6a5f 5497 ssh2_pkt_send_noqueue(ssh, s->pktout);
32874aea 5498
ff3187f6 5499 crWaitUntil(pktin);
5500 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6b5cf8b4 5501 bombout(("expected key exchange group packet from server"));
7ffdbc1a 5502 crStop(0);
32874aea 5503 }
ff3187f6 5504 s->p = ssh2_pkt_getmp(pktin);
5505 s->g = ssh2_pkt_getmp(pktin);
5506 if (!s->p || !s->g) {
5507 bombout(("unable to read mp-ints from incoming group packet"));
5508 crStop(0);
5509 }
d1aaf71d 5510 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
51470298 5511 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5512 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
a92dd380 5513 } else {
d1aaf71d 5514 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5515 ssh->kex_ctx = dh_setup_group(ssh->kex);
51470298 5516 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5517 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
d1aaf71d 5518 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5519 ssh->kex->groupname);
8d5de777 5520 }
e5574168 5521
c6daaa1a 5522 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5523 ssh->kex->hash->text_name);
e5574168 5524 /*
a92dd380 5525 * Now generate and send e for Diffie-Hellman.
e5574168 5526 */
755e0524 5527 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
27cd7fc2 5528 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
ff3187f6 5529 s->pktout = ssh2_pkt_init(s->kex_init_value);
5530 ssh2_pkt_addmp(s->pktout, s->e);
590f6a5f 5531 ssh2_pkt_send_noqueue(ssh, s->pktout);
e5574168 5532
755e0524 5533 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
ff3187f6 5534 crWaitUntil(pktin);
5535 if (pktin->type != s->kex_reply_value) {
6b5cf8b4 5536 bombout(("expected key exchange reply packet from server"));
7ffdbc1a 5537 crStop(0);
7cca0d81 5538 }
755e0524 5539 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
ff3187f6 5540 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5541 s->f = ssh2_pkt_getmp(pktin);
5542 if (!s->f) {
5543 bombout(("unable to parse key exchange reply packet"));
5544 crStop(0);
5545 }
5546 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
e5574168 5547
27cd7fc2 5548 s->K = dh_find_K(ssh->kex_ctx, s->f);
e5574168 5549
755e0524 5550 /* We assume everything from now on will be quick, and it might
5551 * involve user interaction. */
5552 set_busy_status(ssh->frontend, BUSY_NOT);
5553
b672f405 5554 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
34557659 5555 if (!ssh->kex->pdata) {
b672f405 5556 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5557 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5558 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
a92dd380 5559 }
b672f405 5560 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5561 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5562 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
5563 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
5564 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
e5574168 5565
27cd7fc2 5566 dh_cleanup(ssh->kex_ctx);
fabd1805 5567 ssh->kex_ctx = NULL;
3709bfe9 5568
7cca0d81 5569#if 0
765c4200 5570 debug(("Exchange hash is:\n"));
b672f405 5571 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
7cca0d81 5572#endif
5573
51470298 5574 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5575 if (!s->hkey ||
5576 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
b672f405 5577 (char *)s->exchange_hash,
5578 ssh->kex->hash->hlen)) {
6b5cf8b4 5579 bombout(("Server's host key did not match the signature supplied"));
7ffdbc1a 5580 crStop(0);
8d5de777 5581 }
e5574168 5582
5583 /*
7cca0d81 5584 * Authenticate remote host: verify host key. (We've already
5585 * checked the signature of the exchange hash.)
e5574168 5586 */
51470298 5587 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5588 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3d9449a1 5589 ssh_set_frozen(ssh, 1);
5590 s->dlgret = verify_ssh_host_key(ssh->frontend,
5591 ssh->savedhost, ssh->savedport,
5592 ssh->hostkey->keytype, s->keystr,
5593 s->fingerprint,
5594 ssh_dialog_callback, ssh);
5595 if (s->dlgret < 0) {
5596 do {
5597 crReturn(0);
5598 if (pktin) {
5599 bombout(("Unexpected data from server while waiting"
5600 " for user host key response"));
5601 crStop(0);
5602 }
5603 } while (pktin || inlen > 0);
5604 s->dlgret = ssh->user_response;
5605 }
5606 ssh_set_frozen(ssh, 0);
5607 if (s->dlgret == 0) {
9e296bfa 5608 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5609 0, TRUE);
3d9449a1 5610 crStop(0);
5611 }
e13bba36 5612 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5e0d7cb8 5613 logevent("Host key fingerprint is:");
51470298 5614 logevent(s->fingerprint);
5e0d7cb8 5615 }
51470298 5616 sfree(s->fingerprint);
5617 sfree(s->keystr);
5618 ssh->hostkey->freekey(s->hkey);
d39f364a 5619
5620 /*
9442dd57 5621 * The exchange hash from the very first key exchange is also
5622 * the session id, used in session key construction and
5623 * authentication.
5624 */
e13bba36 5625 if (!s->got_session_id) {
b672f405 5626 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
9442dd57 5627 memcpy(ssh->v2_session_id, s->exchange_hash,
5628 sizeof(s->exchange_hash));
b672f405 5629 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6052bb76 5630 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
e13bba36 5631 s->got_session_id = TRUE;
5632 }
9442dd57 5633
5634 /*
7cca0d81 5635 * Send SSH2_MSG_NEWKEYS.
d39f364a 5636 */
ff3187f6 5637 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
590f6a5f 5638 ssh2_pkt_send_noqueue(ssh, s->pktout);
9442dd57 5639 ssh->outgoing_data_size = 0; /* start counting from here */
5640
5641 /*
5642 * We've sent client NEWKEYS, so create and initialise
c64fe7d4 5643 * client-to-server session keys.
9442dd57 5644 */
5645 if (ssh->cs_cipher_ctx)
5646 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5647 ssh->cscipher = s->cscipher_tobe;
5648 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5649
5650 if (ssh->cs_mac_ctx)
5651 ssh->csmac->free_context(ssh->cs_mac_ctx);
5652 ssh->csmac = s->csmac_tobe;
5653 ssh->cs_mac_ctx = ssh->csmac->make_context();
5654
5655 if (ssh->cs_comp_ctx)
5656 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5657 ssh->cscomp = s->cscomp_tobe;
5658 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5659
5660 /*
5661 * Set IVs on client-to-server keys. Here we use the exchange
5662 * hash from the _first_ key exchange.
5663 */
5664 {
5665 unsigned char keyspace[40];
b672f405 5666 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
9442dd57 5667 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
b672f405 5668 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
9442dd57 5669 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
b672f405 5670 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
9442dd57 5671 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5672 }
5673
5674 logeventf(ssh, "Initialised %.200s client->server encryption",
5675 ssh->cscipher->text_name);
5676 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5677 ssh->csmac->text_name);
5678 if (ssh->cscomp->text_name)
5679 logeventf(ssh, "Initialised %s compression",
5680 ssh->cscomp->text_name);
590f6a5f 5681
5682 /*
5683 * Now our end of the key exchange is complete, we can send all
5684 * our queued higher-layer packets.
5685 */
5686 ssh->queueing = FALSE;
5687 ssh2_pkt_queuesend(ssh);
d39f364a 5688
5689 /*
8406eaf9 5690 * Expect SSH2_MSG_NEWKEYS from server.
5691 */
ff3187f6 5692 crWaitUntil(pktin);
5693 if (pktin->type != SSH2_MSG_NEWKEYS) {
6b5cf8b4 5694 bombout(("expected new-keys packet from server"));
7ffdbc1a 5695 crStop(0);
8406eaf9 5696 }
9442dd57 5697 ssh->incoming_data_size = 0; /* start counting from here */
8406eaf9 5698
5699 /*
9442dd57 5700 * We've seen server NEWKEYS, so create and initialise
5701 * server-to-client session keys.
d39f364a 5702 */
371e569c 5703 if (ssh->sc_cipher_ctx)
5704 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
51470298 5705 ssh->sccipher = s->sccipher_tobe;
371e569c 5706 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
e0e1a00d 5707
e0e1a00d 5708 if (ssh->sc_mac_ctx)
5709 ssh->scmac->free_context(ssh->sc_mac_ctx);
51470298 5710 ssh->scmac = s->scmac_tobe;
e0e1a00d 5711 ssh->sc_mac_ctx = ssh->scmac->make_context();
5712
5366aed8 5713 if (ssh->sc_comp_ctx)
5714 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
51470298 5715 ssh->sccomp = s->sccomp_tobe;
5366aed8 5716 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5717
d39f364a 5718 /*
9442dd57 5719 * Set IVs on server-to-client keys. Here we use the exchange
5720 * hash from the _first_ key exchange.
d39f364a 5721 */
51470298 5722 {
5723 unsigned char keyspace[40];
b672f405 5724 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
371e569c 5725 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
b672f405 5726 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
371e569c 5727 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
b672f405 5728 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
e0e1a00d 5729 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
51470298 5730 }
57356d63 5731 logeventf(ssh, "Initialised %.200s server->client encryption",
5732 ssh->sccipher->text_name);
6c135243 5733 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5734 ssh->scmac->text_name);
57356d63 5735 if (ssh->sccomp->text_name)
5736 logeventf(ssh, "Initialised %s decompression",
5737 ssh->sccomp->text_name);
9442dd57 5738
5739 /*
5740 * Free key exchange data.
5741 */
679539d7 5742 freebn(s->f);
679539d7 5743 freebn(s->K);
34557659 5744 if (!ssh->kex->pdata) {
b3949e7e 5745 freebn(s->g);
5746 freebn(s->p);
5747 }
d39f364a 5748
033b4cef 5749 /*
e13bba36 5750 * Key exchange is over. Loop straight back round if we have a
5751 * deferred rekey reason.
5752 */
5753 if (ssh->deferred_rekey_reason) {
5754 logevent(ssh->deferred_rekey_reason);
5755 pktin = NULL;
5756 ssh->deferred_rekey_reason = NULL;
5757 goto begin_key_exchange;
5758 }
5759
5760 /*
5761 * Otherwise, schedule a timer for our next rekey.
9442dd57 5762 */
5763 ssh->kex_in_progress = FALSE;
e6c1536e 5764 ssh->last_rekey = GETTICKCOUNT();
d57f70af 5765 if (ssh->cfg.ssh_rekey_time != 0)
5766 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5767 ssh2_timer, ssh);
e13bba36 5768
9442dd57 5769 /*
0db56f73 5770 * If this is the first key exchange phase, we must pass the
5771 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5772 * wants to see it but because it will need time to initialise
5773 * itself before it sees an actual packet. In subsequent key
5774 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5775 * it would only confuse the layer above.
5776 */
e13bba36 5777 if (s->activated_authconn) {
0e3607ed 5778 crReturn(0);
0db56f73 5779 }
e13bba36 5780 s->activated_authconn = TRUE;
0db56f73 5781
5782 /*
7cca0d81 5783 * Now we're encrypting. Begin returning 1 to the protocol main
5784 * function so that other things can run on top of the
5785 * transport. If we ever see a KEXINIT, we must go back to the
5786 * start.
9442dd57 5787 *
5788 * We _also_ go back to the start if we see pktin==NULL and
5789 * inlen==-1, because this is a special signal meaning
5790 * `initiate client-driven rekey', and `in' contains a message
5791 * giving the reason for the rekey.
033b4cef 5792 */
9442dd57 5793 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5794 (!pktin && inlen == -1))) {
f382c87d 5795 wait_for_rekey:
32874aea 5796 crReturn(1);
e96adf72 5797 }
9442dd57 5798 if (pktin) {
5799 logevent("Server initiated key re-exchange");
5800 } else {
f382c87d 5801 /*
5802 * Special case: if the server bug is set that doesn't
5803 * allow rekeying, we give a different log message and
5804 * continue waiting. (If such a server _initiates_ a rekey,
5805 * we process it anyway!)
5806 */
5807 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5808 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5809 (char *)in);
5810 /* Reset the counters, so that at least this message doesn't
5811 * hit the event log _too_ often. */
5812 ssh->outgoing_data_size = 0;
5813 ssh->incoming_data_size = 0;
5814 if (ssh->cfg.ssh_rekey_time != 0) {
5815 ssh->next_rekey =
5816 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5817 ssh2_timer, ssh);
5818 }
5819 goto wait_for_rekey; /* this is utterly horrid */
5820 } else {
5821 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
f382c87d 5822 }
9442dd57 5823 }
7cca0d81 5824 goto begin_key_exchange;
e5574168 5825
5826 crFinish(1);
5827}
5828
7cca0d81 5829/*
2e85c969 5830 * Add data to an SSH-2 channel output buffer.
783415f8 5831 */
32874aea 5832static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5833 int len)
5834{
5471d09a 5835 bufchain_add(&c->v.v2.outbuffer, buf, len);
783415f8 5836}
5837
5838/*
2e85c969 5839 * Attempt to send data on an SSH-2 channel.
783415f8 5840 */
5471d09a 5841static int ssh2_try_send(struct ssh_channel *c)
32874aea 5842{
51470298 5843 Ssh ssh = c->ssh;
ff3187f6 5844 struct Packet *pktout;
51470298 5845
5471d09a 5846 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5847 int len;
5848 void *data;
5849 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5850 if ((unsigned)len > c->v.v2.remwindow)
5851 len = c->v.v2.remwindow;
5852 if ((unsigned)len > c->v.v2.remmaxpkt)
5853 len = c->v.v2.remmaxpkt;
ff3187f6 5854 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5855 ssh2_pkt_adduint32(pktout, c->remoteid);
5856 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5857 ssh2_pkt_addstring_start(pktout);
5858 ssh2_pkt_addstring_data(pktout, data, len);
5859 end_log_omission(ssh, pktout);
5860 ssh2_pkt_send(ssh, pktout);
5471d09a 5861 bufchain_consume(&c->v.v2.outbuffer, len);
5862 c->v.v2.remwindow -= len;
5863 }
5864
5865 /*
5866 * After having sent as much data as we can, return the amount
5867 * still buffered.
5868 */
5869 return bufchain_size(&c->v.v2.outbuffer);
5870}
5871
1bfc7e93 5872static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5873{
5874 int bufsize;
5875 if (c->closes)
5876 return; /* don't send on closing channels */
5877 bufsize = ssh2_try_send(c);
5878 if (bufsize == 0) {
5879 switch (c->type) {
5880 case CHAN_MAINSESSION:
5881 /* stdin need not receive an unthrottle
5882 * notification since it will be polled */
5883 break;
5884 case CHAN_X11:
5885 x11_unthrottle(c->u.x11.s);
5886 break;
5887 case CHAN_AGENT:
5888 /* agent sockets are request/response and need no
5889 * buffer management */
5890 break;
5891 case CHAN_SOCKDATA:
5892 pfd_unthrottle(c->u.pfd.s);
5893 break;
5894 }
5895 }
5896}
5897
5471d09a 5898/*
2e85c969 5899 * Potentially enlarge the window on an SSH-2 channel.
5471d09a 5900 */
5901static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5902{
51470298 5903 Ssh ssh = c->ssh;
5904
6b69f42e 5905 /*
5906 * Never send WINDOW_ADJUST for a channel that the remote side
5907 * already thinks it's closed; there's no point, since it won't
5908 * be sending any more data anyway.
5909 */
5910 if (c->closes != 0)
5911 return;
5912
d252310a 5913 /*
5914 * Only send a WINDOW_ADJUST if there's significantly more window
5915 * available than the other end thinks there is. This saves us
5916 * sending a WINDOW_ADJUST for every character in a shell session.
5917 *
5918 * "Significant" is arbitrarily defined as half the window size.
5919 */
5920 if (newwin > c->v.v2.locwindow * 2) {
ff3187f6 5921 struct Packet *pktout;
5922
5923 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5924 ssh2_pkt_adduint32(pktout, c->remoteid);
5925 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5926 ssh2_pkt_send(ssh, pktout);
5471d09a 5927 c->v.v2.locwindow = newwin;
783415f8 5928 }
5929}
5930
51df0ab5 5931static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
b09eaa88 5932{
5933 unsigned i = ssh_pkt_getuint32(pktin);
5934 struct ssh_channel *c;
5935 c = find234(ssh->channels, &i, ssh_channelfind);
1bfc7e93 5936 if (c && !c->closes) {
b09eaa88 5937 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
1bfc7e93 5938 ssh2_try_send_and_unthrottle(c);
5939 }
b09eaa88 5940}
5941
51df0ab5 5942static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5943{
5944 char *data;
6d44acc9 5945 int length;
51df0ab5 5946 unsigned i = ssh_pkt_getuint32(pktin);
5947 struct ssh_channel *c;
5948 c = find234(ssh->channels, &i, ssh_channelfind);
5949 if (!c)
5950 return; /* nonexistent channel */
5951 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5952 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5953 return; /* extended but not stderr */
5954 ssh_pkt_getstring(pktin, &data, &length);
5955 if (data) {
5956 int bufsize = 0;
5957 c->v.v2.locwindow -= length;
5958 switch (c->type) {
5959 case CHAN_MAINSESSION:
5960 bufsize =
5961 from_backend(ssh->frontend, pktin->type ==
5962 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5963 data, length);
5964 break;
5965 case CHAN_X11:
5966 bufsize = x11_send(c->u.x11.s, data, length);
5967 break;
5968 case CHAN_SOCKDATA:
5969 bufsize = pfd_send(c->u.pfd.s, data, length);
5970 break;
5971 case CHAN_AGENT:
5972 while (length > 0) {
5973 if (c->u.a.lensofar < 4) {
aa63ab7e 5974 unsigned int l = min(4 - c->u.a.lensofar, length);
51df0ab5 5975 memcpy(c->u.a.msglen + c->u.a.lensofar,
5976 data, l);
5977 data += l;
5978 length -= l;
5979 c->u.a.lensofar += l;
5980 }
5981 if (c->u.a.lensofar == 4) {
5982 c->u.a.totallen =
5983 4 + GET_32BIT(c->u.a.msglen);
5984 c->u.a.message = snewn(c->u.a.totallen,
5985 unsigned char);
5986 memcpy(c->u.a.message, c->u.a.msglen, 4);
5987 }
5988 if (c->u.a.lensofar >= 4 && length > 0) {
aa63ab7e 5989 unsigned int l =
51df0ab5 5990 min(c->u.a.totallen - c->u.a.lensofar,
5991 length);
5992 memcpy(c->u.a.message + c->u.a.lensofar,
5993 data, l);
5994 data += l;
5995 length -= l;
5996 c->u.a.lensofar += l;
5997 }
5998 if (c->u.a.lensofar == c->u.a.totallen) {
5999 void *reply;
6000 int replylen;
6001 if (agent_query(c->u.a.message,
6002 c->u.a.totallen,
6003 &reply, &replylen,
6004 ssh_agentf_callback, c))
6005 ssh_agentf_callback(c, reply, replylen);
6006 sfree(c->u.a.message);
6007 c->u.a.lensofar = 0;
6008 }
6009 }
6010 bufsize = 0;
6011 break;
6012 }
6013 /*
6014 * If we are not buffering too much data,
6015 * enlarge the window again at the remote side.
6016 */
6017 if (bufsize < OUR_V2_WINSIZE)
6018 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
6019 }
6020}
6021
6022static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6023{
6024 unsigned i = ssh_pkt_getuint32(pktin);
6025 struct ssh_channel *c;
6026
6027 c = find234(ssh->channels, &i, ssh_channelfind);
6028 if (!c)
6029 return; /* nonexistent channel */
6030
6031 if (c->type == CHAN_X11) {
6032 /*
6033 * Remote EOF on an X11 channel means we should
6034 * wrap up and close the channel ourselves.
6035 */
6036 x11_close(c->u.x11.s);
6037 sshfwd_close(c);
6038 } else if (c->type == CHAN_AGENT) {
6039 sshfwd_close(c);
6040 } else if (c->type == CHAN_SOCKDATA) {
6041 pfd_close(c->u.pfd.s);
6042 sshfwd_close(c);
6043 }
6044}
6045
6046static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6047{
6048 unsigned i = ssh_pkt_getuint32(pktin);
6049 struct ssh_channel *c;
6050 struct Packet *pktout;
6051
6052 c = find234(ssh->channels, &i, ssh_channelfind);
64d6ff88 6053 if (!c || c->halfopen) {
51df0ab5 6054 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6055 c ? "half-open" : "nonexistent", i));
6056 return;
6057 }
6058 /* Do pre-close processing on the channel. */
6059 switch (c->type) {
6060 case CHAN_MAINSESSION:
6061 ssh->mainchan = NULL;
6062 update_specials_menu(ssh->frontend);
6063 break;
6064 case CHAN_X11:
6065 if (c->u.x11.s != NULL)
6066 x11_close(c->u.x11.s);
6067 sshfwd_close(c);
6068 break;
6069 case CHAN_AGENT:
6070 sshfwd_close(c);
6071 break;
6072 case CHAN_SOCKDATA:
6073 if (c->u.pfd.s != NULL)
6074 pfd_close(c->u.pfd.s);
6075 sshfwd_close(c);
6076 break;
6077 }
6078 if (c->closes == 0) {
6079 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6080 ssh2_pkt_adduint32(pktout, c->remoteid);
6081 ssh2_pkt_send(ssh, pktout);
6082 }
6083 del234(ssh->channels, c);
6084 bufchain_clear(&c->v.v2.outbuffer);
6085 sfree(c);
6086
6087 /*
6088 * See if that was the last channel left open.
6089 * (This is only our termination condition if we're
6090 * not running in -N mode.)
6091 */
6092 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
51df0ab5 6093 /*
6094 * We used to send SSH_MSG_DISCONNECT here,
6095 * because I'd believed that _every_ conforming
2e85c969 6096 * SSH-2 connection had to end with a disconnect
51df0ab5 6097 * being sent by at least one side; apparently
6098 * I was wrong and it's perfectly OK to
6099 * unceremoniously slam the connection shut
6100 * when you're done, and indeed OpenSSH feels
6101 * this is more polite than sending a
6102 * DISCONNECT. So now we don't.
6103 */
9e296bfa 6104 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
51df0ab5 6105 }
6106}
6107
6108static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6109{
6110 unsigned i = ssh_pkt_getuint32(pktin);
6111 struct ssh_channel *c;
6112 struct Packet *pktout;
6113
6114 c = find234(ssh->channels, &i, ssh_channelfind);
6115 if (!c)
6116 return; /* nonexistent channel */
6117 if (c->type != CHAN_SOCKDATA_DORMANT)
6118 return; /* dunno why they're confirming this */
6119 c->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 6120 c->halfopen = FALSE;
51df0ab5 6121 c->type = CHAN_SOCKDATA;
6122 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6123 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6124 if (c->u.pfd.s)
6125 pfd_confirm(c->u.pfd.s);
6126 if (c->closes) {
6127 /*
6128 * We have a pending close on this channel,
6129 * which we decided on before the server acked
6130 * the channel open. So now we know the
6131 * remoteid, we can close it again.
6132 */
6133 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6134 ssh2_pkt_adduint32(pktout, c->remoteid);
6135 ssh2_pkt_send(ssh, pktout);
6136 }
6137}
6138
6139static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6140{
6141 static const char *const reasons[] = {
6142 "<unknown reason code>",
6143 "Administratively prohibited",
6144 "Connect failed",
6145 "Unknown channel type",
6146 "Resource shortage",
6147 };
6148 unsigned i = ssh_pkt_getuint32(pktin);
6149 unsigned reason_code;
6150 char *reason_string;
6151 int reason_length;
51df0ab5 6152 struct ssh_channel *c;
6153 c = find234(ssh->channels, &i, ssh_channelfind);
6154 if (!c)
6155 return; /* nonexistent channel */
6156 if (c->type != CHAN_SOCKDATA_DORMANT)
6157 return; /* dunno why they're failing this */
6158
6159 reason_code = ssh_pkt_getuint32(pktin);
6160 if (reason_code >= lenof(reasons))
6161 reason_code = 0; /* ensure reasons[reason_code] in range */
6162 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
fb983202 6163 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6164 reasons[reason_code], reason_length, reason_string);
51df0ab5 6165
6166 pfd_close(c->u.pfd.s);
6167
6168 del234(ssh->channels, c);
6169 sfree(c);
6170}
6171
6172static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6173{
6174 unsigned localid;
6175 char *type;
6176 int typelen, want_reply;
6177 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6178 struct ssh_channel *c;
6179 struct Packet *pktout;
6180
6181 localid = ssh_pkt_getuint32(pktin);
6182 ssh_pkt_getstring(pktin, &type, &typelen);
6183 want_reply = ssh2_pkt_getbool(pktin);
6184
6185 /*
6186 * First, check that the channel exists. Otherwise,
6187 * we can instantly disconnect with a rude message.
6188 */
6189 c = find234(ssh->channels, &localid, ssh_channelfind);
6190 if (!c) {
9e296bfa 6191 char *buf = dupprintf("Received channel request for nonexistent"
6192 " channel %d", localid);
6193 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6194 sfree(buf);
51df0ab5 6195 return;
6196 }
6197
6198 /*
6199 * Having got the channel number, we now look at
6200 * the request type string to see if it's something
6201 * we recognise.
6202 */
6203 if (c == ssh->mainchan) {
6204 /*
6205 * We recognise "exit-status" and "exit-signal" on
6206 * the primary channel.
6207 */
6208 if (typelen == 11 &&
6209 !memcmp(type, "exit-status", 11)) {
6210
6211 ssh->exitcode = ssh_pkt_getuint32(pktin);
6212 logeventf(ssh, "Server sent command exit status %d",
6213 ssh->exitcode);
6214 reply = SSH2_MSG_CHANNEL_SUCCESS;
6215
6216 } else if (typelen == 11 &&
6217 !memcmp(type, "exit-signal", 11)) {
6218
6219 int is_plausible = TRUE, is_int = FALSE;
6220 char *fmt_sig = "", *fmt_msg = "";
6221 char *msg;
6222 int msglen = 0, core = FALSE;
6223 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6224 * provide an `int' for the signal, despite its
6225 * having been a `string' in the drafts since at
6226 * least 2001. (Fixed in session.c 1.147.) Try to
6227 * infer which we can safely parse it as. */
6228 {
6229 unsigned char *p = pktin->body +
6230 pktin->savedpos;
6231 long len = pktin->length - pktin->savedpos;
6232 unsigned long num = GET_32BIT(p); /* what is it? */
6233 /* If it's 0, it hardly matters; assume string */
6234 if (num == 0) {
6235 is_int = FALSE;
6236 } else {
6237 int maybe_int = FALSE, maybe_str = FALSE;
6238#define CHECK_HYPOTHESIS(offset, result) \
6239 do { \
6240 long q = offset; \
6241 if (q >= 0 && q+4 <= len) { \
6242 q = q + 4 + GET_32BIT(p+q); \
6243 if (q >= 0 && q+4 <= len && \
c849ff23 6244 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
51df0ab5 6245 result = TRUE; \
6246 } \
6247 } while(0)
6248 CHECK_HYPOTHESIS(4+1, maybe_int);
6249 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6250#undef CHECK_HYPOTHESIS
6251 if (maybe_int && !maybe_str)
6252 is_int = TRUE;
6253 else if (!maybe_int && maybe_str)
6254 is_int = FALSE;
6255 else
6256 /* Crikey. Either or neither. Panic. */
6257 is_plausible = FALSE;
6258 }
6259 }
6260 if (is_plausible) {
6261 if (is_int) {
6262 /* Old non-standard OpenSSH. */
6263 int signum = ssh_pkt_getuint32(pktin);
6264 fmt_sig = dupprintf(" %d", signum);
6265 } else {
6266 /* As per the drafts. */
6267 char *sig;
6268 int siglen;
6269 ssh_pkt_getstring(pktin, &sig, &siglen);
6270 /* Signal name isn't supposed to be blank, but
6271 * let's cope gracefully if it is. */
6272 if (siglen) {
6273 fmt_sig = dupprintf(" \"%.*s\"",
6274 siglen, sig);
6275 }
6276 }
6277 core = ssh2_pkt_getbool(pktin);
6278 ssh_pkt_getstring(pktin, &msg, &msglen);
6279 if (msglen) {
6280 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6281 }
6282 /* ignore lang tag */
6283 } /* else don't attempt to parse */
6284 logeventf(ssh, "Server exited on signal%s%s%s",
6285 fmt_sig, core ? " (core dumped)" : "",
6286 fmt_msg);
6287 if (*fmt_sig) sfree(fmt_sig);
6288 if (*fmt_msg) sfree(fmt_msg);
6289 reply = SSH2_MSG_CHANNEL_SUCCESS;
6290
6291 }
6292 } else {
6293 /*
6294 * This is a channel request we don't know
6295 * about, so we now either ignore the request
6296 * or respond with CHANNEL_FAILURE, depending
6297 * on want_reply.
6298 */
6299 reply = SSH2_MSG_CHANNEL_FAILURE;
6300 }
6301 if (want_reply) {
6302 pktout = ssh2_pkt_init(reply);
6303 ssh2_pkt_adduint32(pktout, c->remoteid);
6304 ssh2_pkt_send(ssh, pktout);
6305 }
6306}
6307
6308static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6309{
6310 char *type;
6311 int typelen, want_reply;
6312 struct Packet *pktout;
6313
6314 ssh_pkt_getstring(pktin, &type, &typelen);
6315 want_reply = ssh2_pkt_getbool(pktin);
6316
6317 /*
6318 * We currently don't support any global requests
6319 * at all, so we either ignore the request or
6320 * respond with REQUEST_FAILURE, depending on
6321 * want_reply.
6322 */
6323 if (want_reply) {
6324 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6325 ssh2_pkt_send(ssh, pktout);
6326 }
6327}
6328
6329static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6330{
6331 char *type;
6332 int typelen;
6333 char *peeraddr;
6334 int peeraddrlen;
6335 int peerport;
6336 char *error = NULL;
6337 struct ssh_channel *c;
6338 unsigned remid, winsize, pktsize;
6339 struct Packet *pktout;
6340
6341 ssh_pkt_getstring(pktin, &type, &typelen);
6342 c = snew(struct ssh_channel);
6343 c->ssh = ssh;
6344
6345 remid = ssh_pkt_getuint32(pktin);
6346 winsize = ssh_pkt_getuint32(pktin);
6347 pktsize = ssh_pkt_getuint32(pktin);
6348
6349 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6350 char *addrstr;
6351
6352 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6353 addrstr = snewn(peeraddrlen+1, char);
6354 memcpy(addrstr, peeraddr, peeraddrlen);
6355 addrstr[peeraddrlen] = '\0';
6356 peerport = ssh_pkt_getuint32(pktin);
6357
6358 logeventf(ssh, "Received X11 connect request from %s:%d",
6359 addrstr, peerport);
6360
6361 if (!ssh->X11_fwd_enabled)
6362 error = "X11 forwarding is not enabled";
6363 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6364 ssh->x11auth, addrstr, peerport,
6365 &ssh->cfg) != NULL) {
6366 error = "Unable to open an X11 connection";
6367 } else {
6368 logevent("Opening X11 forward connection succeeded");
6369 c->type = CHAN_X11;
6370 }
6371
6372 sfree(addrstr);
6373 } else if (typelen == 15 &&
6374 !memcmp(type, "forwarded-tcpip", 15)) {
6375 struct ssh_rportfwd pf, *realpf;
6376 char *dummy;
6377 int dummylen;
6378 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6379 pf.sport = ssh_pkt_getuint32(pktin);
6380 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6381 peerport = ssh_pkt_getuint32(pktin);
6382 realpf = find234(ssh->rportfwds, &pf, NULL);
6383 logeventf(ssh, "Received remote port %d open request "
6384 "from %s:%d", pf.sport, peeraddr, peerport);
6385 if (realpf == NULL) {
6386 error = "Remote port is not recognised";
6387 } else {
6388 const char *e = pfd_newconnect(&c->u.pfd.s,
6389 realpf->dhost,
6390 realpf->dport, c,
05581745 6391 &ssh->cfg,
6392 realpf->pfrec->addressfamily);
51df0ab5 6393 logeventf(ssh, "Attempting to forward remote port to "
6394 "%s:%d", realpf->dhost, realpf->dport);
6395 if (e != NULL) {
6396 logeventf(ssh, "Port open failed: %s", e);
6397 error = "Port open failed";
6398 } else {
6399 logevent("Forwarded port opened successfully");
6400 c->type = CHAN_SOCKDATA;
6401 }
6402 }
6403 } else if (typelen == 22 &&
c49cf994 6404 !memcmp(type, "auth-agent@openssh.com", 22)) {
51df0ab5 6405 if (!ssh->agentfwd_enabled)
6406 error = "Agent forwarding is not enabled";
6407 else {
6408 c->type = CHAN_AGENT; /* identify channel type */
6409 c->u.a.lensofar = 0;
6410 }
6411 } else {
6412 error = "Unsupported channel type requested";
6413 }
6414
6415 c->remoteid = remid;
64d6ff88 6416 c->halfopen = FALSE;
51df0ab5 6417 if (error) {
6418 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6419 ssh2_pkt_adduint32(pktout, c->remoteid);
6420 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6421 ssh2_pkt_addstring(pktout, error);
6422 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6423 ssh2_pkt_send(ssh, pktout);
6424 logeventf(ssh, "Rejected channel open: %s", error);
6425 sfree(c);
6426 } else {
6427 c->localid = alloc_channel_id(ssh);
6428 c->closes = 0;
6429 c->v.v2.locwindow = OUR_V2_WINSIZE;
6430 c->v.v2.remwindow = winsize;
6431 c->v.v2.remmaxpkt = pktsize;
6432 bufchain_init(&c->v.v2.outbuffer);
6433 add234(ssh->channels, c);
6434 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6435 ssh2_pkt_adduint32(pktout, c->remoteid);
6436 ssh2_pkt_adduint32(pktout, c->localid);
6437 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
954d5c5a 6438 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
51df0ab5 6439 ssh2_pkt_send(ssh, pktout);
6440 }
6441}
6442
6bbce591 6443/*
6444 * Buffer banner messages for later display at some convenient point.
6445 */
6446static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6447{
6448 /* Arbitrary limit to prevent unbounded inflation of buffer */
6449 if (bufchain_size(&ssh->banner) <= 131072) {
6450 char *banner = NULL;
6451 int size = 0;
6452 ssh_pkt_getstring(pktin, &banner, &size);
6453 if (banner)
6454 bufchain_add(&ssh->banner, banner, size);
6455 }
6456}
6457
c6ccd5c2 6458/* Helper function to deal with sending tty modes for "pty-req" */
6459static void ssh2_send_ttymode(void *data, char *mode, char *val)
6460{
6461 struct Packet *pktout = (struct Packet *)data;
6462 int i = 0;
6463 unsigned int arg = 0;
6464 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6465 if (i == lenof(ssh_ttymodes)) return;
6466 switch (ssh_ttymodes[i].type) {
6467 case TTY_OP_CHAR:
6468 arg = ssh_tty_parse_specchar(val);
6469 break;
6470 case TTY_OP_BOOL:
6471 arg = ssh_tty_parse_boolean(val);
6472 break;
6473 }
6474 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6475 ssh2_pkt_adduint32(pktout, arg);
6476}
6477
783415f8 6478/*
2e85c969 6479 * Handle the SSH-2 userauth and connection layers.
7cca0d81 6480 */
ff3187f6 6481static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6482 struct Packet *pktin)
7cca0d81 6483{
51470298 6484 struct do_ssh2_authconn_state {
6485 enum {
51470298 6486 AUTH_TYPE_NONE,
6487 AUTH_TYPE_PUBLICKEY,
6488 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6489 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6490 AUTH_TYPE_PASSWORD,
6491 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6492 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6493 } type;
a1a1fae4 6494 int done_service_req;
51470298 6495 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
94cd7c3a 6496 int tried_pubkey_config, done_agent;
edd0cb8a 6497 int kbd_inter_refused;
51470298 6498 int we_are_in;
edd0cb8a 6499 prompts_t *cur_prompt;
6500 int num_prompts;
51470298 6501 char username[100];
e955d348 6502 char *password;
51470298 6503 int got_username;
51470298 6504 void *publickey_blob;
6505 int publickey_bloblen;
edd0cb8a 6506 int publickey_encrypted;
6507 char *publickey_algorithm;
6508 char *publickey_comment;
94cd7c3a 6509 unsigned char agent_request[5], *agent_response, *agentp;
6510 int agent_responselen;
6511 unsigned char *pkblob_in_agent;
51470298 6512 int keyi, nkeys;
51470298 6513 char *pkblob, *alg, *commentp;
6514 int pklen, alglen, commentlen;
6515 int siglen, retlen, len;
6516 char *q, *agentreq, *ret;
6517 int try_send;
73feed4f 6518 int num_env, env_left, env_ok;
ff3187f6 6519 struct Packet *pktout;
51470298 6520 };
6521 crState(do_ssh2_authconn_state);
6522
6523 crBegin(ssh->do_ssh2_authconn_crstate);
e5574168 6524
a1a1fae4 6525 s->done_service_req = FALSE;
6526 s->we_are_in = FALSE;
6527 if (!ssh->cfg.ssh_no_userauth) {
6528 /*
6529 * Request userauth protocol, and await a response to it.
6530 */
6531 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6532 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6533 ssh2_pkt_send(ssh, s->pktout);
6534 crWaitUntilV(pktin);
6535 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6536 s->done_service_req = TRUE;
6537 }
6538 if (!s->done_service_req) {
6539 /*
6540 * Request connection protocol directly, without authentication.
6541 */
6542 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6543 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6544 ssh2_pkt_send(ssh, s->pktout);
6545 crWaitUntilV(pktin);
6546 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6547 s->we_are_in = TRUE; /* no auth required */
6548 } else {
6549 bombout(("Server refused service request"));
6550 crStopV;
6551 }
8d5de777 6552 }
7cca0d81 6553
94cd7c3a 6554 /* Arrange to be able to deal with any BANNERs that come in.
6555 * (We do this now as packets may come in during the next bit.) */
6556 bufchain_init(&ssh->banner);
6557 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6558 ssh2_msg_userauth_banner;
6559
7cca0d81 6560 /*
edd0cb8a 6561 * Misc one-time setup for authentication.
6562 */
6563 s->publickey_blob = NULL;
6564 if (!s->we_are_in) {
6565
6566 /*
6567 * Load the public half of any configured public key file
6568 * for later use.
6569 */
6570 if (!filename_is_null(ssh->cfg.keyfile)) {
6571 int keytype;
6572 logeventf(ssh, "Reading private key file \"%.150s\"",
6573 filename_to_str(&ssh->cfg.keyfile));
6574 keytype = key_type(&ssh->cfg.keyfile);
6575 if (keytype == SSH_KEYTYPE_SSH2) {
6576 const char *error;
6577 s->publickey_blob =
6578 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6579 &s->publickey_algorithm,
6580 &s->publickey_bloblen,
6581 &s->publickey_comment, &error);
6582 if (s->publickey_blob) {
6583 s->publickey_encrypted =
6584 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
6585 } else {
6586 char *msgbuf;
6587 logeventf(ssh, "Unable to load private key (%s)",
6588 error);
6589 msgbuf = dupprintf("Unable to load private key file "
6590 "\"%.150s\" (%s)\r\n",
6591 filename_to_str(&ssh->cfg.keyfile),
6592 error);
6593 c_write_str(ssh, msgbuf);
6594 sfree(msgbuf);
6595 }
6596 } else {
6597 char *msgbuf;
6598 logeventf(ssh, "Unable to use this key file (%s)",
6599 key_type_to_str(keytype));
6600 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6601 " (%s)\r\n",
6602 filename_to_str(&ssh->cfg.keyfile),
6603 key_type_to_str(keytype));
6604 c_write_str(ssh, msgbuf);
6605 sfree(msgbuf);
6606 s->publickey_blob = NULL;
6607 }
6608 }
6609
94cd7c3a 6610 /*
6611 * Find out about any keys Pageant has (but if there's a
6612 * public key configured, filter out all others).
6613 */
6614 s->nkeys = 0;
6615 s->agent_response = NULL;
6616 s->pkblob_in_agent = NULL;
116f229d 6617 if (ssh->cfg.tryagent && agent_exists()) {
94cd7c3a 6618
6619 void *r;
6620
6621 logevent("Pageant is running. Requesting keys.");
6622
6623 /* Request the keys held by the agent. */
6624 PUT_32BIT(s->agent_request, 1);
6625 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6626 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
6627 ssh_agent_callback, ssh)) {
6628 do {
6629 crReturnV;
6630 if (pktin) {
6631 bombout(("Unexpected data from server while"
6632 " waiting for agent response"));
6633 crStopV;
6634 }
6635 } while (pktin || inlen > 0);
6636 r = ssh->agent_response;
6637 s->agent_responselen = ssh->agent_response_len;
6638 }
6639 s->agent_response = (unsigned char *) r;
6640 if (s->agent_response && s->agent_responselen >= 5 &&
6641 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6642 int keyi;
6643 unsigned char *p;
6644 p = s->agent_response + 5;
6645 s->nkeys = GET_32BIT(p);
6646 p += 4;
6647 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6648 if (s->publickey_blob) {
6649 /* See if configured key is in agent. */
6650 for (keyi = 0; keyi < s->nkeys; keyi++) {
6651 s->pklen = GET_32BIT(p);
6652 if (s->pklen == s->publickey_bloblen &&
6653 !memcmp(p+4, s->publickey_blob,
6654 s->publickey_bloblen)) {
6655 logeventf(ssh, "Pageant key #%d matches "
6656 "configured key file", keyi);
6657 s->keyi = keyi;
6658 s->pkblob_in_agent = p;
6659 break;
6660 }
6661 p += 4 + s->pklen;
6662 p += GET_32BIT(p) + 4; /* comment */
6663 }
6664 if (!s->pkblob_in_agent) {
6665 logevent("Configured key file not in Pageant");
6666 s->nkeys = 0;
6667 }
6668 }
6669 }
6670 }
6671
edd0cb8a 6672 }
6673
6674 /*
1408a877 6675 * We repeat this whole loop, including the username prompt,
6676 * until we manage a successful authentication. If the user
51470298 6677 * types the wrong _password_, they can be sent back to the
6678 * beginning to try another username, if this is configured on.
6679 * (If they specify a username in the config, they are never
6680 * asked, even if they do give a wrong password.)
1408a877 6681 *
6682 * I think this best serves the needs of
6683 *
6684 * - the people who have no configuration, no keys, and just
6685 * want to try repeated (username,password) pairs until they
6686 * type both correctly
6687 *
6688 * - people who have keys and configuration but occasionally
6689 * need to fall back to passwords
6690 *
6691 * - people with a key held in Pageant, who might not have
6692 * logged in to a particular machine before; so they want to
6693 * type a username, and then _either_ their key will be
6694 * accepted, _or_ they will type a password. If they mistype
6695 * the username they will want to be able to get back and
6696 * retype it!
7cca0d81 6697 */
51470298 6698 s->username[0] = '\0';
6699 s->got_username = FALSE;
a1a1fae4 6700 while (!s->we_are_in) {
1408a877 6701 /*
6702 * Get a username.
6703 */
86916870 6704 if (s->got_username && !ssh->cfg.change_username) {
5bb641e1 6705 /*
6706 * We got a username last time round this loop, and
6707 * with change_username turned off we don't try to get
6708 * it again.
6709 */
aa09f7d0 6710 } else if (!*ssh->cfg.username) {
edd0cb8a 6711 int ret; /* need not be kept over crReturn */
6712 s->cur_prompt = new_prompts(ssh->frontend);
6713 s->cur_prompt->to_server = TRUE;
6714 s->cur_prompt->name = dupstr("SSH login name");
6715 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
6716 lenof(s->username));
6717 ret = get_userpass_input(s->cur_prompt, NULL, 0);
6718 while (ret < 0) {
51470298 6719 ssh->send_ok = 1;
edd0cb8a 6720 crWaitUntilV(!pktin);
6721 ret = get_userpass_input(s->cur_prompt, in, inlen);
6722 ssh->send_ok = 0;
32874aea 6723 }
edd0cb8a 6724 if (!ret) {
6725 /*
6726 * get_userpass_input() failed to get a username.
6727 * Terminate.
6728 */
6729 free_prompts(s->cur_prompt);
6730 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
6731 crStopV;
6732 }
6733 memcpy(s->username, s->cur_prompt->prompts[0]->result,
6734 lenof(s->username));
6735 free_prompts(s->cur_prompt);
7cca0d81 6736 } else {
57356d63 6737 char *stuff;
86916870 6738 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
51470298 6739 s->username[sizeof(s->username)-1] = '\0';
65a22376 6740 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
57356d63 6741 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
51470298 6742 c_write_str(ssh, stuff);
57356d63 6743 sfree(stuff);
7cca0d81 6744 }
6745 }
51470298 6746 s->got_username = TRUE;
7cca0d81 6747
65a22376 6748 /*
1408a877 6749 * Send an authentication request using method "none": (a)
6750 * just in case it succeeds, and (b) so that we know what
6751 * authentication methods we can usefully try next.
65a22376 6752 */
51470298 6753 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6754
ff3187f6 6755 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6756 ssh2_pkt_addstring(s->pktout, s->username);
6757 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6758 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6759 ssh2_pkt_send(ssh, s->pktout);
51470298 6760 s->type = AUTH_TYPE_NONE;
6761 s->gotit = FALSE;
6762 s->we_are_in = FALSE;
6763
6764 s->tried_pubkey_config = FALSE;
6ac3a551 6765 s->kbd_inter_refused = FALSE;
65a22376 6766
94cd7c3a 6767 /* Reset agent request state. */
6768 s->done_agent = FALSE;
6769 if (s->agent_response) {
6770 if (s->pkblob_in_agent) {
6771 s->agentp = s->pkblob_in_agent;
6772 } else {
6773 s->agentp = s->agent_response + 5 + 4;
6774 s->keyi = 0;
6775 }
6776 }
6777
1408a877 6778 while (1) {
6779 /*
6780 * Wait for the result of the last authentication request.
6781 */
51470298 6782 if (!s->gotit)
ff3187f6 6783 crWaitUntilV(pktin);
6bbce591 6784 /*
6785 * Now is a convenient point to spew any banner material
6786 * that we've accumulated. (This should ensure that when
6787 * we exit the auth loop, we haven't any left to deal
6788 * with.)
6789 */
6790 {
6791 int size = bufchain_size(&ssh->banner);
32874aea 6792 /*
6793 * Don't show the banner if we're operating in
6794 * non-verbose non-interactive mode. (It's probably
6795 * a script, which means nobody will read the
6796 * banner _anyway_, and moreover the printing of
6797 * the banner will screw up processing on the
6798 * output of (say) plink.)
6799 */
6bbce591 6800 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
6801 char *banner = snewn(size, char);
6802 bufchain_fetch(&ssh->banner, banner, size);
6803 c_write_untrusted(ssh, banner, size);
6804 sfree(banner);
32874aea 6805 }
6bbce591 6806 bufchain_clear(&ssh->banner);
1408a877 6807 }
ff3187f6 6808 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
1408a877 6809 logevent("Access granted");
51470298 6810 s->we_are_in = TRUE;
1408a877 6811 break;
6812 }
65a22376 6813
e955d348 6814 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6815 bombout(("Strange packet received during authentication: "
6816 "type %d", pktin->type));
7ffdbc1a 6817 crStopV;
65a22376 6818 }
6819
51470298 6820 s->gotit = FALSE;
65a22376 6821
1408a877 6822 /*
6823 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6824 * we can look at the string in it and know what we can
6825 * helpfully try next.
6826 */
ff3187f6 6827 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
1408a877 6828 char *methods;
6829 int methlen;
ff3187f6 6830 ssh_pkt_getstring(pktin, &methods, &methlen);
ff3187f6 6831 if (!ssh2_pkt_getbool(pktin)) {
1408a877 6832 /*
6833 * We have received an unequivocal Access
6834 * Denied. This can translate to a variety of
6835 * messages:
6836 *
6837 * - if we'd just tried "none" authentication,
6838 * it's not worth printing anything at all
6839 *
6840 * - if we'd just tried a public key _offer_,
6841 * the message should be "Server refused our
6842 * key" (or no message at all if the key
6843 * came from Pageant)
6844 *
6845 * - if we'd just tried anything else, the
6846 * message really should be "Access denied".
6847 *
6848 * Additionally, if we'd just tried password
6849 * authentication, we should break out of this
6850 * whole loop so as to go back to the username
91f57d1f 6851 * prompt (iff we're configured to allow
6852 * username change attempts).
1408a877 6853 */
51470298 6854 if (s->type == AUTH_TYPE_NONE) {
1408a877 6855 /* do nothing */
51470298 6856 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6857 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6858 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6859 c_write_str(ssh, "Server refused our key\r\n");
1408a877 6860 logevent("Server refused public key");
51470298 6861 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4bdf7c46 6862 /* server declined keyboard-interactive; ignore */
1408a877 6863 } else {
51470298 6864 c_write_str(ssh, "Access denied\r\n");
1408a877 6865 logevent("Access denied");
91f57d1f 6866 if (s->type == AUTH_TYPE_PASSWORD &&
6867 ssh->cfg.change_username) {
6c9dce7c 6868 /* XXX perhaps we should allow
6869 * keyboard-interactive to do this too? */
51470298 6870 s->we_are_in = FALSE;
1408a877 6871 break;
6872 }
6873 }
6874 } else {
51470298 6875 c_write_str(ssh, "Further authentication required\r\n");
1408a877 6876 logevent("Further authentication required");
6877 }
65a22376 6878
51470298 6879 s->can_pubkey =
32874aea 6880 in_commasep_string("publickey", methods, methlen);
51470298 6881 s->can_passwd =
32874aea 6882 in_commasep_string("password", methods, methlen);
86916870 6883 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
761187b6 6884 in_commasep_string("keyboard-interactive", methods, methlen);
1408a877 6885 }
65a22376 6886
51470298 6887 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
65a22376 6888
94cd7c3a 6889 if (s->can_pubkey && !s->done_agent && s->nkeys) {
0405e71f 6890
1983e559 6891 /*
94cd7c3a 6892 * Attempt public-key authentication using a key from Pageant.
1983e559 6893 */
1983e559 6894
51470298 6895 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6896 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 6897
94cd7c3a 6898 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6899
6900 /* Unpack key from agent response */
6901 s->pklen = GET_32BIT(s->agentp);
6902 s->agentp += 4;
6903 s->pkblob = (char *)s->agentp;
6904 s->agentp += s->pklen;
6905 s->alglen = GET_32BIT(s->pkblob);
6906 s->alg = s->pkblob + 4;
6907 s->commentlen = GET_32BIT(s->agentp);
6908 s->agentp += 4;
6909 s->commentp = (char *)s->agentp;
6910 s->agentp += s->commentlen;
6911 /* s->agentp now points at next key, if any */
6912
6913 /* See if server will accept it */
6914 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6915 ssh2_pkt_addstring(s->pktout, s->username);
6916 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6917 /* service requested */
6918 ssh2_pkt_addstring(s->pktout, "publickey");
6919 /* method */
6920 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6921 ssh2_pkt_addstring_start(s->pktout);
6922 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6923 ssh2_pkt_addstring_start(s->pktout);
6924 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6925 ssh2_pkt_send(ssh, s->pktout);
6926 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
1983e559 6927
94cd7c3a 6928 crWaitUntilV(pktin);
6929 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
1983e559 6930
94cd7c3a 6931 /* Offer of key refused. */
6932 s->gotit = TRUE;
1983e559 6933
94cd7c3a 6934 } else {
6935
6936 void *vret;
1983e559 6937
94cd7c3a 6938 if (flags & FLAG_VERBOSE) {
6939 c_write_str(ssh, "Authenticating with "
6940 "public key \"");
6941 c_write(ssh, s->commentp, s->commentlen);
6942 c_write_str(ssh, "\" from agent\r\n");
6943 }
1983e559 6944
94cd7c3a 6945 /*
6946 * Server is willing to accept the key.
6947 * Construct a SIGN_REQUEST.
6948 */
6949 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6950 ssh2_pkt_addstring(s->pktout, s->username);
6951 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6952 /* service requested */
6953 ssh2_pkt_addstring(s->pktout, "publickey");
6954 /* method */
6955 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
6956 ssh2_pkt_addstring_start(s->pktout);
6957 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6958 ssh2_pkt_addstring_start(s->pktout);
6959 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6960
6961 /* Ask agent for signature. */
6962 s->siglen = s->pktout->length - 5 + 4 +
6963 ssh->v2_session_id_len;
6964 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6965 s->siglen -= 4;
6966 s->len = 1; /* message type */
6967 s->len += 4 + s->pklen; /* key blob */
6968 s->len += 4 + s->siglen; /* data to sign */
6969 s->len += 4; /* flags */
6970 s->agentreq = snewn(4 + s->len, char);
6971 PUT_32BIT(s->agentreq, s->len);
6972 s->q = s->agentreq + 4;
6973 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6974 PUT_32BIT(s->q, s->pklen);
6975 s->q += 4;
6976 memcpy(s->q, s->pkblob, s->pklen);
6977 s->q += s->pklen;
6978 PUT_32BIT(s->q, s->siglen);
6979 s->q += 4;
6980 /* Now the data to be signed... */
6981 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6982 PUT_32BIT(s->q, ssh->v2_session_id_len);
51470298 6983 s->q += 4;
94cd7c3a 6984 }
6985 memcpy(s->q, ssh->v2_session_id,
6986 ssh->v2_session_id_len);
6987 s->q += ssh->v2_session_id_len;
6988 memcpy(s->q, s->pktout->data + 5,
6989 s->pktout->length - 5);
6990 s->q += s->pktout->length - 5;
6991 /* And finally the (zero) flags word. */
6992 PUT_32BIT(s->q, 0);
6993 if (!agent_query(s->agentreq, s->len + 4,
6994 &vret, &s->retlen,
6995 ssh_agent_callback, ssh)) {
6996 do {
6997 crReturnV;
6998 if (pktin) {
6999 bombout(("Unexpected data from server"
7000 " while waiting for agent"
7001 " response"));
7002 crStopV;
1983e559 7003 }
94cd7c3a 7004 } while (pktin || inlen > 0);
7005 vret = ssh->agent_response;
7006 s->retlen = ssh->agent_response_len;
7007 }
7008 s->ret = vret;
7009 sfree(s->agentreq);
7010 if (s->ret) {
7011 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7012 logevent("Sending Pageant's response");
7013 ssh2_add_sigblob(ssh, s->pktout,
7014 s->pkblob, s->pklen,
7015 s->ret + 9,
7016 GET_32BIT(s->ret + 5));
7017 ssh2_pkt_send(ssh, s->pktout);
7018 s->type = AUTH_TYPE_PUBLICKEY;
7019 } else {
7020 /* FIXME: less drastic response */
7021 bombout(("Pageant failed to answer challenge"));
7022 crStopV;
1983e559 7023 }
7024 }
1983e559 7025 }
94cd7c3a 7026
7027 /* Do we have any keys left to try? */
7028 if (s->pkblob_in_agent) {
7029 s->done_agent = TRUE;
7030 s->tried_pubkey_config = TRUE;
7031 } else {
7032 s->keyi++;
7033 if (s->keyi >= s->nkeys)
7034 s->done_agent = TRUE;
7035 }
1983e559 7036
edd0cb8a 7037 } else if (s->can_pubkey && s->publickey_blob &&
7038 !s->tried_pubkey_config) {
65a22376 7039
edd0cb8a 7040 struct ssh2_userkey *key; /* not live over crReturn */
7041 char *passphrase; /* not live over crReturn */
65a22376 7042
51470298 7043 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7044 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
00db133f 7045
edd0cb8a 7046 s->tried_pubkey_config = TRUE;
7047
65a22376 7048 /*
1408a877 7049 * Try the public key supplied in the configuration.
7050 *
7051 * First, offer the public blob to see if the server is
7052 * willing to accept it.
65a22376 7053 */
ff3187f6 7054 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7055 ssh2_pkt_addstring(s->pktout, s->username);
edd0cb8a 7056 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7057 /* service requested */
7058 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7059 ssh2_pkt_addbool(s->pktout, FALSE);
7060 /* no signature included */
7061 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7062 ssh2_pkt_addstring_start(s->pktout);
7063 ssh2_pkt_addstring_data(s->pktout,
7064 (char *)s->publickey_blob,
7065 s->publickey_bloblen);
ff3187f6 7066 ssh2_pkt_send(ssh, s->pktout);
edd0cb8a 7067 logevent("Offered public key");
ff3187f6 7068
7069 crWaitUntilV(pktin);
edd0cb8a 7070 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7071 /* Key refused. Give up. */
7072 s->gotit = TRUE; /* reconsider message next loop */
7073 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7074 continue; /* process this new message */
45068b27 7075 }
edd0cb8a 7076 logevent("Offer of public key accepted");
af659722 7077
45068b27 7078 /*
edd0cb8a 7079 * Actually attempt a serious authentication using
7080 * the key.
45068b27 7081 */
edd0cb8a 7082 if (flags & FLAG_VERBOSE) {
7083 c_write_str(ssh, "Authenticating with public key \"");
7084 c_write_str(ssh, s->publickey_comment);
7085 c_write_str(ssh, "\"\r\n");
7086 }
7087 key = NULL;
7088 while (!key) {
7089 const char *error; /* not live over crReturn */
7090 if (s->publickey_encrypted) {
7091 /*
7092 * Get a passphrase from the user.
7093 */
7094 int ret; /* need not be kept over crReturn */
7095 s->cur_prompt = new_prompts(ssh->frontend);
7096 s->cur_prompt->to_server = FALSE;
7097 s->cur_prompt->name = dupstr("SSH key passphrase");
7098 add_prompt(s->cur_prompt,
7099 dupprintf("Passphrase for key \"%.100s\": ",
7100 s->publickey_comment),
7101 FALSE, SSH_MAX_PASSWORD_LEN);
7102 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7103 while (ret < 0) {
7104 ssh->send_ok = 1;
7105 crWaitUntilV(!pktin);
7106 ret = get_userpass_input(s->cur_prompt,
7107 in, inlen);
7108 ssh->send_ok = 0;
7109 }
7110 if (!ret) {
7111 /* Failed to get a passphrase. Terminate. */
7112 free_prompts(s->cur_prompt);
7113 ssh_disconnect(ssh, NULL,
7114 "Unable to authenticate",
7115 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7116 TRUE);
7117 crStopV;
85fdbe25 7118 }
edd0cb8a 7119 passphrase =
7120 dupstr(s->cur_prompt->prompts[0]->result);
7121 free_prompts(s->cur_prompt);
45068b27 7122 } else {
edd0cb8a 7123 passphrase = NULL; /* no passphrase needed */
45068b27 7124 }
1408a877 7125
edd0cb8a 7126 /*
7127 * Try decrypting the key.
7128 */
7129 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7130 &error);
7131 if (passphrase) {
7132 /* burn the evidence */
7133 memset(passphrase, 0, strlen(passphrase));
7134 sfree(passphrase);
7135 }
7136 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7137 if (passphrase &&
7138 (key == SSH2_WRONG_PASSPHRASE)) {
7139 c_write_str(ssh, "Wrong passphrase\r\n");
7140 key = NULL;
7141 /* and loop again */
7142 } else {
7143 c_write_str(ssh, "Unable to load private key (");
7144 c_write_str(ssh, error);
7145 c_write_str(ssh, ")\r\n");
7146 key = NULL;
7147 break; /* try something else */
7148 }
1408a877 7149 }
65a22376 7150 }
65a22376 7151
edd0cb8a 7152 if (key) {
1dd353b5 7153 unsigned char *pkblob, *sigblob, *sigdata;
7154 int pkblob_len, sigblob_len, sigdata_len;
edd0cb8a 7155 int p;
65a22376 7156
1408a877 7157 /*
7158 * We have loaded the private key and the server
7159 * has announced that it's willing to accept it.
7160 * Hallelujah. Generate a signature and send it.
7161 */
ff3187f6 7162 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7163 ssh2_pkt_addstring(s->pktout, s->username);
edd0cb8a 7164 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7165 /* service requested */
7166 ssh2_pkt_addstring(s->pktout, "publickey");
7167 /* method */
ff3187f6 7168 ssh2_pkt_addbool(s->pktout, TRUE);
edd0cb8a 7169 /* signature follows */
ff3187f6 7170 ssh2_pkt_addstring(s->pktout, key->alg->name);
edd0cb8a 7171 pkblob = key->alg->public_blob(key->data,
7172 &pkblob_len);
ff3187f6 7173 ssh2_pkt_addstring_start(s->pktout);
edd0cb8a 7174 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7175 pkblob_len);
1408a877 7176
7177 /*
7178 * The data to be signed is:
7179 *
7180 * string session-id
7181 *
7182 * followed by everything so far placed in the
7183 * outgoing packet.
7184 */
b672f405 7185 sigdata_len = s->pktout->length - 5 + 4 +
7186 ssh->v2_session_id_len;
edd0cb8a 7187 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7188 sigdata_len -= 4;
92d60585 7189 sigdata = snewn(sigdata_len, unsigned char);
edd0cb8a 7190 p = 0;
7191 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7192 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7193 p += 4;
7194 }
b672f405 7195 memcpy(sigdata+p, ssh->v2_session_id,
7196 ssh->v2_session_id_len);
7197 p += ssh->v2_session_id_len;
ff3187f6 7198 memcpy(sigdata+p, s->pktout->data + 5,
7199 s->pktout->length - 5);
edd0cb8a 7200 p += s->pktout->length - 5;
7201 assert(p == sigdata_len);
d8baa528 7202 sigblob = key->alg->sign(key->data, (char *)sigdata,
1dd353b5 7203 sigdata_len, &sigblob_len);
ff3187f6 7204 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
1dd353b5 7205 sigblob, sigblob_len);
7206 sfree(pkblob);
7207 sfree(sigblob);
1408a877 7208 sfree(sigdata);
7209
ff3187f6 7210 ssh2_pkt_send(ssh, s->pktout);
51470298 7211 s->type = AUTH_TYPE_PUBLICKEY;
75374b2f 7212 key->alg->freekey(key->data);
1408a877 7213 }
edd0cb8a 7214
7215 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
7216
7217 /*
7218 * Keyboard-interactive authentication.
7219 */
edd0cb8a 7220
edd0cb8a 7221 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7222
7223 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7224 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7225
7226 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7227 ssh2_pkt_addstring(s->pktout, s->username);
7228 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7229 /* service requested */
7230 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
7231 /* method */
7232 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7233 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
7234 ssh2_pkt_send(ssh, s->pktout);
7235
7236 crWaitUntilV(pktin);
7237 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7238 /* Server is not willing to do keyboard-interactive
b8e3173d 7239 * at all (or, bizarrely but legally, accepts the
7240 * user without actually issuing any prompts).
7241 * Give up on it entirely. */
edd0cb8a 7242 s->gotit = TRUE;
7243 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7244 logevent("Keyboard-interactive authentication refused");
7245 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7246 s->kbd_inter_refused = TRUE; /* don't try it again */
7247 continue;
7248 }
7249
7250 /*
b8e3173d 7251 * Loop while the server continues to send INFO_REQUESTs.
edd0cb8a 7252 */
b8e3173d 7253 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
edd0cb8a 7254
b8e3173d 7255 char *name, *inst, *lang;
7256 int name_len, inst_len, lang_len;
7257 int i;
7258
7259 /*
7260 * We've got a fresh USERAUTH_INFO_REQUEST.
7261 * Get the preamble and start building a prompt.
7262 */
7263 ssh_pkt_getstring(pktin, &name, &name_len);
7264 ssh_pkt_getstring(pktin, &inst, &inst_len);
7265 ssh_pkt_getstring(pktin, &lang, &lang_len);
7266 s->cur_prompt = new_prompts(ssh->frontend);
7267 s->cur_prompt->to_server = TRUE;
7268 if (name_len) {
7269 /* FIXME: better prefix to distinguish from
7270 * local prompts? */
7271 s->cur_prompt->name =
7272 dupprintf("SSH server: %.*s", name_len, name);
7273 s->cur_prompt->name_reqd = TRUE;
7274 } else {
7275 s->cur_prompt->name =
7276 dupstr("SSH server authentication");
7277 s->cur_prompt->name_reqd = FALSE;
edd0cb8a 7278 }
b8e3173d 7279 /* FIXME: ugly to print "Using..." in prompt _every_
7280 * time round. Can this be done more subtly? */
7281 s->cur_prompt->instruction =
7282 dupprintf("Using keyboard-interactive authentication.%s%.*s",
7283 inst_len ? "\n" : "", inst_len, inst);
7284 s->cur_prompt->instr_reqd = TRUE;
edd0cb8a 7285
b8e3173d 7286 /*
7287 * Get the prompts from the packet.
7288 */
7289 s->num_prompts = ssh_pkt_getuint32(pktin);
7290 for (i = 0; i < s->num_prompts; i++) {
7291 char *prompt;
7292 int prompt_len;
7293 int echo;
7294 static char noprompt[] =
7295 "<server failed to send prompt>: ";
7296
7297 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7298 echo = ssh2_pkt_getbool(pktin);
7299 if (!prompt_len) {
7300 prompt = noprompt;
7301 prompt_len = lenof(noprompt)-1;
7302 }
7303 add_prompt(s->cur_prompt,
7304 dupprintf("%.*s", prompt_len, prompt),
7305 echo, SSH_MAX_PASSWORD_LEN);
edd0cb8a 7306 }
b8e3173d 7307
7308 /*
7309 * Get the user's responses.
7310 */
7311 if (s->num_prompts) {
7312 int ret; /* not live over crReturn */
7313 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7314 while (ret < 0) {
7315 ssh->send_ok = 1;
7316 crWaitUntilV(!pktin);
7317 ret = get_userpass_input(s->cur_prompt, in, inlen);
7318 ssh->send_ok = 0;
7319 }
7320 if (!ret) {
7321 /*
7322 * Failed to get responses. Terminate.
7323 */
7324 free_prompts(s->cur_prompt);
7325 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7326 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7327 TRUE);
7328 crStopV;
7329 }
edd0cb8a 7330 }
b8e3173d 7331
7332 /*
7333 * Send the responses to the server.
7334 */
7335 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7336 s->pktout->forcepad = 256;
7337 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7338 for (i=0; i < s->num_prompts; i++) {
7339 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7340 ssh2_pkt_addstring(s->pktout,
7341 s->cur_prompt->prompts[i]->result);
7342 end_log_omission(ssh, s->pktout);
7343 }
7344 ssh2_pkt_send(ssh, s->pktout);
7345
7346 /*
7347 * Get the next packet in case it's another
7348 * INFO_REQUEST.
7349 */
7350 crWaitUntilV(pktin);
7351
edd0cb8a 7352 }
7353
7354 /*
b8e3173d 7355 * We should have SUCCESS or FAILURE now.
edd0cb8a 7356 */
b8e3173d 7357 s->gotit = TRUE;
edd0cb8a 7358
7359 } else if (s->can_passwd) {
7360
7361 /*
7362 * Plain old password authentication.
7363 */
7364 int ret; /* not live over crReturn */
e955d348 7365 int changereq_first_time; /* not live over crReturn */
edd0cb8a 7366
edd0cb8a 7367 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7368 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7369
7370 s->cur_prompt = new_prompts(ssh->frontend);
7371 s->cur_prompt->to_server = TRUE;
7372 s->cur_prompt->name = dupstr("SSH password");
7373 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
7374 s->username,
7375 ssh->savedhost),
7376 FALSE, SSH_MAX_PASSWORD_LEN);
7377
7378 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7379 while (ret < 0) {
7380 ssh->send_ok = 1;
7381 crWaitUntilV(!pktin);
7382 ret = get_userpass_input(s->cur_prompt, in, inlen);
7383 ssh->send_ok = 0;
7384 }
7385 if (!ret) {
7386 /*
7387 * Failed to get responses. Terminate.
7388 */
7389 free_prompts(s->cur_prompt);
7390 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7391 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7392 TRUE);
7393 crStopV;
7394 }
e955d348 7395 /*
7396 * Squirrel away the password. (We may need it later if
7397 * asked to change it.)
7398 */
7399 s->password = dupstr(s->cur_prompt->prompts[0]->result);
7400 free_prompts(s->cur_prompt);
edd0cb8a 7401
7402 /*
7403 * Send the password packet.
7404 *
95d2d262 7405 * We pad out the password packet to 256 bytes to make
7406 * it harder for an attacker to find the length of the
7407 * user's password.
1408a877 7408 *
95d2d262 7409 * Anyone using a password longer than 256 bytes
7410 * probably doesn't have much to worry about from
1408a877 7411 * people who find out how long their password is!
65a22376 7412 */
ff3187f6 7413 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
95d2d262 7414 s->pktout->forcepad = 256;
ff3187f6 7415 ssh2_pkt_addstring(s->pktout, s->username);
edd0cb8a 7416 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7417 /* service requested */
ff3187f6 7418 ssh2_pkt_addstring(s->pktout, "password");
7419 ssh2_pkt_addbool(s->pktout, FALSE);
7420 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
e955d348 7421 ssh2_pkt_addstring(s->pktout, s->password);
ff3187f6 7422 end_log_omission(ssh, s->pktout);
95d2d262 7423 ssh2_pkt_send(ssh, s->pktout);
0d43337a 7424 logevent("Sent password");
28f4d4f0 7425 s->type = AUTH_TYPE_PASSWORD;
edd0cb8a 7426
e955d348 7427 /*
7428 * Wait for next packet, in case it's a password change
7429 * request.
7430 */
7431 crWaitUntilV(pktin);
7432 changereq_first_time = TRUE;
7433
7434 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
7435
7436 /*
7437 * We're being asked for a new password
7438 * (perhaps not for the first time).
7439 * Loop until the server accepts it.
7440 */
7441
7442 int got_new = FALSE; /* not live over crReturn */
7443 char *prompt; /* not live over crReturn */
7444 int prompt_len; /* not live over crReturn */
7445
7446 {
7447 char *msg;
7448 if (changereq_first_time)
7449 msg = "Server requested password change";
7450 else
7451 msg = "Server rejected new password";
7452 logevent(msg);
7453 c_write_str(ssh, msg);
7454 c_write_str(ssh, "\r\n");
7455 }
7456
7457 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7458
7459 s->cur_prompt = new_prompts(ssh->frontend);
7460 s->cur_prompt->to_server = TRUE;
7461 s->cur_prompt->name = dupstr("New SSH password");
7462 s->cur_prompt->instruction =
7463 dupprintf("%.*s", prompt_len, prompt);
7464 s->cur_prompt->instr_reqd = TRUE;
7465 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
7466 FALSE, SSH_MAX_PASSWORD_LEN);
7467 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
7468 FALSE, SSH_MAX_PASSWORD_LEN);
7469
7470 /*
7471 * Loop until the user manages to enter the same
7472 * password twice.
7473 */
7474 while (!got_new) {
7475
7476 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7477 while (ret < 0) {
7478 ssh->send_ok = 1;
7479 crWaitUntilV(!pktin);
7480 ret = get_userpass_input(s->cur_prompt, in, inlen);
7481 ssh->send_ok = 0;
7482 }
7483 if (!ret) {
7484 /*
7485 * Failed to get responses. Terminate.
7486 */
7487 /* burn the evidence */
7488 free_prompts(s->cur_prompt);
7489 memset(s->password, 0, strlen(s->password));
7490 sfree(s->password);
7491 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7492 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7493 TRUE);
7494 crStopV;
7495 }
7496
7497 /*
7498 * Check the two passwords match.
7499 */
7500 got_new = (strcmp(s->cur_prompt->prompts[0]->result,
7501 s->cur_prompt->prompts[1]->result)
7502 == 0);
7503 if (!got_new)
7504 /* They don't. Silly user. */
7505 c_write_str(ssh, "Passwords do not match\r\n");
7506
7507 }
7508
7509 /*
7510 * Send the new password (along with the old one).
7511 * (see above for padding rationale)
7512 */
7513 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7514 s->pktout->forcepad = 256;
7515 ssh2_pkt_addstring(s->pktout, s->username);
7516 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7517 /* service requested */
7518 ssh2_pkt_addstring(s->pktout, "password");
7519 ssh2_pkt_addbool(s->pktout, TRUE);
7520 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7521 ssh2_pkt_addstring(s->pktout, s->password);
7522 ssh2_pkt_addstring(s->pktout,
7523 s->cur_prompt->prompts[0]->result);
7524 free_prompts(s->cur_prompt);
7525 end_log_omission(ssh, s->pktout);
7526 ssh2_pkt_send(ssh, s->pktout);
7527 logevent("Sent new password");
7528
7529 /*
7530 * Now see what the server has to say about it.
7531 * (If it's CHANGEREQ again, it's not happy with the
7532 * new password.)
7533 */
7534 crWaitUntilV(pktin);
7535 changereq_first_time = FALSE;
7536
7537 }
7538
7539 /*
7540 * We need to reexamine the current pktin at the top
7541 * of the loop. Either:
7542 * - we weren't asked to change password at all, in
7543 * which case it's a SUCCESS or FAILURE with the
7544 * usual meaning
7545 * - we sent a new password, and the server was
7546 * either OK with it (SUCCESS or FAILURE w/partial
7547 * success) or unhappy with the _old_ password
7548 * (FAILURE w/o partial success)
7549 * In any of these cases, we go back to the top of
7550 * the loop and start again.
7551 */
7552 s->gotit = TRUE;
7553
7554 /*
7555 * We don't need the old password any more, in any
7556 * case. Burn the evidence.
7557 */
7558 memset(s->password, 0, strlen(s->password));
7559 sfree(s->password);
7560
1408a877 7561 } else {
edd0cb8a 7562
9e296bfa 7563 ssh_disconnect(ssh, NULL,
7564 "No supported authentication methods available",
7565 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7566 FALSE);
7ffdbc1a 7567 crStopV;
edd0cb8a 7568
65a22376 7569 }
edd0cb8a 7570
65a22376 7571 }
a1a1fae4 7572 }
6bbce591 7573 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7cca0d81 7574
edd0cb8a 7575 /* Clear up various bits and pieces from authentication. */
7576 if (s->publickey_blob) {
7577 sfree(s->publickey_blob);
7578 sfree(s->publickey_comment);
7579 }
94cd7c3a 7580 if (s->agent_response)
7581 sfree(s->agent_response);
edd0cb8a 7582
7cca0d81 7583 /*
a1a1fae4 7584 * Now the connection protocol has started, one way or another.
7cca0d81 7585 */
7586
0ed48730 7587 ssh->channels = newtree234(ssh_channelcmp);
7588
7cca0d81 7589 /*
b09eaa88 7590 * Set up handlers for some connection protocol messages, so we
7591 * don't have to handle them repeatedly in this coroutine.
7592 */
7593 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7594 ssh2_msg_channel_window_adjust;
51df0ab5 7595 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7596 ssh2_msg_global_request;
b09eaa88 7597
7598 /*
0ed48730 7599 * Create the main session channel.
7cca0d81 7600 */
0ed48730 7601 if (!ssh->cfg.ssh_no_shell) {
7602 ssh->mainchan = snew(struct ssh_channel);
7603 ssh->mainchan->ssh = ssh;
7604 ssh->mainchan->localid = alloc_channel_id(ssh);
ff3187f6 7605 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7606 ssh2_pkt_addstring(s->pktout, "session");
7607 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
0ed48730 7608 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 7609 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
954d5c5a 7610 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 7611 ssh2_pkt_send(ssh, s->pktout);
7612 crWaitUntilV(pktin);
7613 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
0ed48730 7614 bombout(("Server refused to open a session"));
7615 crStopV;
7616 /* FIXME: error data comes back in FAILURE packet */
7617 }
ff3187f6 7618 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
0ed48730 7619 bombout(("Server's channel confirmation cited wrong channel"));
7620 crStopV;
7621 }
ff3187f6 7622 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
64d6ff88 7623 ssh->mainchan->halfopen = FALSE;
0ed48730 7624 ssh->mainchan->type = CHAN_MAINSESSION;
7625 ssh->mainchan->closes = 0;
ff3187f6 7626 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7627 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
0ed48730 7628 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7629 add234(ssh->channels, ssh->mainchan);
62638676 7630 update_specials_menu(ssh->frontend);
0ed48730 7631 logevent("Opened channel for session");
7632 } else
7633 ssh->mainchan = NULL;
7cca0d81 7634
7635 /*
51df0ab5 7636 * Now we have a channel, make dispatch table entries for
7637 * general channel-based messages.
7638 */
7639 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7640 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7641 ssh2_msg_channel_data;
7642 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7643 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7644 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7645 ssh2_msg_channel_open_confirmation;
7646 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7647 ssh2_msg_channel_open_failure;
7648 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7649 ssh2_msg_channel_request;
7650 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7651 ssh2_msg_channel_open;
7652
7653 /*
783415f8 7654 * Potentially enable X11 forwarding.
7655 */
0ed48730 7656 if (ssh->mainchan && ssh->cfg.x11_forward) {
32874aea 7657 char proto[20], data[64];
7658 logevent("Requesting X11 forwarding");
302121de 7659 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
86916870 7660 data, sizeof(data), ssh->cfg.x11_auth);
7661 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
ff3187f6 7662 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7663 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7664 ssh2_pkt_addstring(s->pktout, "x11-req");
7665 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7666 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7667 ssh2_pkt_addstring(s->pktout, proto);
f68353be 7668 /*
7669 * Note that while we blank the X authentication data here, we don't
7670 * take any special action to blank the start of an X11 channel,
7671 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7672 * without having session blanking enabled is likely to leak your
7673 * cookie into the log.
7674 */
178c3872 7675 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
ff3187f6 7676 ssh2_pkt_addstring(s->pktout, data);
178c3872 7677 end_log_omission(ssh, s->pktout);
ff3187f6 7678 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7679 ssh2_pkt_send(ssh, s->pktout);
32874aea 7680
b09eaa88 7681 crWaitUntilV(pktin);
32874aea 7682
ff3187f6 7683 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7684 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7685 bombout(("Unexpected response to X11 forwarding request:"
ff3187f6 7686 " packet type %d", pktin->type));
7ffdbc1a 7687 crStopV;
32874aea 7688 }
7689 logevent("X11 forwarding refused");
7690 } else {
7691 logevent("X11 forwarding enabled");
51470298 7692 ssh->X11_fwd_enabled = TRUE;
32874aea 7693 }
783415f8 7694 }
7695
7696 /*
bc240b21 7697 * Enable port forwardings.
7698 */
06fadff5 7699 ssh_setup_portfwd(ssh, &ssh->cfg);
bc240b21 7700
7701 /*
36c2a3e9 7702 * Potentially enable agent forwarding.
7703 */
0ed48730 7704 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
32874aea 7705 logevent("Requesting OpenSSH-style agent forwarding");
ff3187f6 7706 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7707 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7708 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7709 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7710 ssh2_pkt_send(ssh, s->pktout);
32874aea 7711
b09eaa88 7712 crWaitUntilV(pktin);
32874aea 7713
ff3187f6 7714 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7715 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7716 bombout(("Unexpected response to agent forwarding request:"
ff3187f6 7717 " packet type %d", pktin->type));
7ffdbc1a 7718 crStopV;
32874aea 7719 }
7720 logevent("Agent forwarding refused");
7721 } else {
7722 logevent("Agent forwarding enabled");
51470298 7723 ssh->agentfwd_enabled = TRUE;
32874aea 7724 }
36c2a3e9 7725 }
7726
7727 /*
7cca0d81 7728 * Now allocate a pty for the session.
7729 */
0ed48730 7730 if (ssh->mainchan && !ssh->cfg.nopty) {
a5dd8467 7731 /* Unpick the terminal-speed string. */
7732 /* XXX perhaps we should allow no speeds to be sent. */
db219738 7733 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7734 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
a5dd8467 7735 /* Build the pty request. */
ff3187f6 7736 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7737 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7738 ssh2_pkt_addstring(s->pktout, "pty-req");
7739 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7740 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7741 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7742 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7743 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7744 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7745 ssh2_pkt_addstring_start(s->pktout);
c6ccd5c2 7746 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7747 ssh2_send_ttymode, (void *)s->pktout);
7748 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
ff3187f6 7749 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
c6ccd5c2 7750 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
ff3187f6 7751 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7752 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7753 ssh2_pkt_send(ssh, s->pktout);
51470298 7754 ssh->state = SSH_STATE_INTERMED;
32874aea 7755
b09eaa88 7756 crWaitUntilV(pktin);
32874aea 7757
ff3187f6 7758 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7759 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7760 bombout(("Unexpected response to pty request:"
ff3187f6 7761 " packet type %d", pktin->type));
7ffdbc1a 7762 crStopV;
32874aea 7763 }
51470298 7764 c_write_str(ssh, "Server refused to allocate pty\r\n");
7765 ssh->editing = ssh->echoing = 1;
32874aea 7766 } else {
a5dd8467 7767 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
db219738 7768 ssh->ospeed, ssh->ispeed);
32874aea 7769 }
0965bee0 7770 } else {
51470298 7771 ssh->editing = ssh->echoing = 1;
7cca0d81 7772 }
7773
7774 /*
73feed4f 7775 * Send environment variables.
7776 *
7777 * Simplest thing here is to send all the requests at once, and
7778 * then wait for a whole bunch of successes or failures.
7779 */
7780 if (ssh->mainchan && *ssh->cfg.environmt) {
7781 char *e = ssh->cfg.environmt;
7782 char *var, *varend, *val;
7783
7784 s->num_env = 0;
7785
7786 while (*e) {
7787 var = e;
7788 while (*e && *e != '\t') e++;
7789 varend = e;
7790 if (*e == '\t') e++;
7791 val = e;
7792 while (*e) e++;
7793 e++;
7794
ff3187f6 7795 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7796 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7797 ssh2_pkt_addstring(s->pktout, "env");
7798 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7799 ssh2_pkt_addstring_start(s->pktout);
7800 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7801 ssh2_pkt_addstring(s->pktout, val);
7802 ssh2_pkt_send(ssh, s->pktout);
73feed4f 7803
7804 s->num_env++;
7805 }
7806
7807 logeventf(ssh, "Sent %d environment variables", s->num_env);
7808
7809 s->env_ok = 0;
7810 s->env_left = s->num_env;
7811
7812 while (s->env_left > 0) {
b09eaa88 7813 crWaitUntilV(pktin);
73feed4f 7814
ff3187f6 7815 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7816 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
73feed4f 7817 bombout(("Unexpected response to environment request:"
ff3187f6 7818 " packet type %d", pktin->type));
73feed4f 7819 crStopV;
7820 }
7821 } else {
7822 s->env_ok++;
7823 }
7824
7825 s->env_left--;
7826 }
7827
7828 if (s->env_ok == s->num_env) {
7829 logevent("All environment variables successfully set");
7830 } else if (s->env_ok == 0) {
7831 logevent("All environment variables refused");
7832 c_write_str(ssh, "Server refused to set environment variables\r\n");
7833 } else {
7834 logeventf(ssh, "%d environment variables refused",
7835 s->num_env - s->env_ok);
7836 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7837 }
7838 }
7839
7840 /*
fd5e5847 7841 * Start a shell or a remote command. We may have to attempt
7842 * this twice if the config data has provided a second choice
7843 * of command.
7cca0d81 7844 */
0ed48730 7845 if (ssh->mainchan) while (1) {
fd5e5847 7846 int subsys;
7847 char *cmd;
7848
51470298 7849 if (ssh->fallback_cmd) {
86916870 7850 subsys = ssh->cfg.ssh_subsys2;
7851 cmd = ssh->cfg.remote_cmd_ptr2;
fd5e5847 7852 } else {
86916870 7853 subsys = ssh->cfg.ssh_subsys;
7854 cmd = ssh->cfg.remote_cmd_ptr;
04c52f10 7855 if (!cmd) cmd = ssh->cfg.remote_cmd;
fd5e5847 7856 }
7857
ff3187f6 7858 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7859 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
fd5e5847 7860 if (subsys) {
ff3187f6 7861 ssh2_pkt_addstring(s->pktout, "subsystem");
7862 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7863 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7864 } else if (*cmd) {
ff3187f6 7865 ssh2_pkt_addstring(s->pktout, "exec");
7866 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7867 ssh2_pkt_addstring(s->pktout, cmd);
fd5e5847 7868 } else {
ff3187f6 7869 ssh2_pkt_addstring(s->pktout, "shell");
7870 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
32874aea 7871 }
ff3187f6 7872 ssh2_pkt_send(ssh, s->pktout);
b09eaa88 7873
7874 crWaitUntilV(pktin);
7875
ff3187f6 7876 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7877 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6b5cf8b4 7878 bombout(("Unexpected response to shell/command request:"
ff3187f6 7879 " packet type %d", pktin->type));
7ffdbc1a 7880 crStopV;
fd5e5847 7881 }
7882 /*
7883 * We failed to start the command. If this is the
7884 * fallback command, we really are finished; if it's
7885 * not, and if the fallback command exists, try falling
7886 * back to it before complaining.
7887 */
86916870 7888 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
fd5e5847 7889 logevent("Primary command failed; attempting fallback");
51470298 7890 ssh->fallback_cmd = TRUE;
fd5e5847 7891 continue;
7892 }
6b5cf8b4 7893 bombout(("Server refused to start a shell/command"));
7ffdbc1a 7894 crStopV;
fd5e5847 7895 } else {
7896 logevent("Started a shell/command");
32874aea 7897 }
fd5e5847 7898 break;
7cca0d81 7899 }
7900
51470298 7901 ssh->state = SSH_STATE_SESSION;
7902 if (ssh->size_needed)
7903 ssh_size(ssh, ssh->term_width, ssh->term_height);
7904 if (ssh->eof_needed)
7905 ssh_special(ssh, TS_EOF);
6e48c3fe 7906
7cca0d81 7907 /*
7908 * Transfer data!
7909 */
b9d7bcad 7910 if (ssh->ldisc)
7911 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
0ed48730 7912 if (ssh->mainchan)
7913 ssh->send_ok = 1;
7cca0d81 7914 while (1) {
e5574168 7915 crReturnV;
51470298 7916 s->try_send = FALSE;
ff3187f6 7917 if (pktin) {
2b7540a7 7918
51df0ab5 7919 /*
7920 * _All_ the connection-layer packets we expect to
7921 * receive are now handled by the dispatch table.
7922 * Anything that reaches here must be bogus.
7923 */
32874aea 7924
51df0ab5 7925 bombout(("Strange packet received: type %d", pktin->type));
7926 crStopV;
0ed48730 7927 } else if (ssh->mainchan) {
32874aea 7928 /*
7929 * We have spare data. Add it to the channel buffer.
7930 */
d8baa528 7931 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
51470298 7932 s->try_send = TRUE;
32874aea 7933 }
51470298 7934 if (s->try_send) {
32874aea 7935 int i;
7936 struct ssh_channel *c;
7937 /*
7938 * Try to send data on all channels if we can.
7939 */
1bfc7e93 7940 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7941 ssh2_try_send_and_unthrottle(c);
7cca0d81 7942 }
e5574168 7943 }
7944
7945 crFinishV;
7946}
7947
7948/*
2e85c969 7949 * Handlers for SSH-2 messages that might arrive at any moment.
b09eaa88 7950 */
409bfa77 7951static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
b09eaa88 7952{
7953 /* log reason code in disconnect message */
7954 char *buf, *msg;
7955 int nowlen, reason, msglen;
7956
7957 reason = ssh_pkt_getuint32(pktin);
7958 ssh_pkt_getstring(pktin, &msg, &msglen);
7959
7960 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7961 buf = dupprintf("Received disconnect message (%s)",
7962 ssh2_disconnect_reasons[reason]);
7963 } else {
7964 buf = dupprintf("Received disconnect message (unknown"
7965 " type %d)", reason);
7966 }
7967 logevent(buf);
7968 sfree(buf);
7969 buf = dupprintf("Disconnection message text: %n%.*s",
7970 &nowlen, msglen, msg);
7971 logevent(buf);
7972 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7973 reason,
7974 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7975 ssh2_disconnect_reasons[reason] : "unknown",
7976 buf+nowlen));
7977 sfree(buf);
7978}
7979
409bfa77 7980static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
b09eaa88 7981{
7982 /* log the debug message */
fb983202 7983 char *msg;
b09eaa88 7984 int msglen;
7985 int always_display;
7986
7987 /* XXX maybe we should actually take notice of this */
7988 always_display = ssh2_pkt_getbool(pktin);
7989 ssh_pkt_getstring(pktin, &msg, &msglen);
7990
fb983202 7991 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
b09eaa88 7992}
7993
409bfa77 7994static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
b09eaa88 7995{
7996 struct Packet *pktout;
7997 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7998 ssh2_pkt_adduint32(pktout, pktin->sequence);
7999 /*
8000 * UNIMPLEMENTED messages MUST appear in the same order as the
8001 * messages they respond to. Hence, never queue them.
8002 */
8003 ssh2_pkt_send_noqueue(ssh, pktout);
8004}
8005
8006/*
2e85c969 8007 * Handle the top-level SSH-2 protocol.
7cca0d81 8008 */
b09eaa88 8009static void ssh2_protocol_setup(Ssh ssh)
8010{
8011 int i;
8012
8013 /*
8014 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
8015 */
8016 for (i = 0; i < 256; i++)
8017 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
8018
8019 /*
8020 * Any message we actually understand, we set to NULL so that
8021 * the coroutines will get it.
8022 */
8023 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
8024 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
8025 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
8026 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
8027 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
8028 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
8029 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
8030 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
8031 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
8032 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
8033 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
8034 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
8035 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
8036 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
8037 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8038 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
8039 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
8040 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
8041 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
8042 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
8043 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
8044 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
8045 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
8046 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
8047 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
8048 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
8049 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
8050 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
8051 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
8052 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
8053 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
8054 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
8055 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
8056
8057 /*
8058 * These special message types we install handlers for.
8059 */
8060 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
2e85c969 8061 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
b09eaa88 8062 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
8063}
8064
9442dd57 8065static void ssh2_timer(void *ctx, long now)
8066{
8067 Ssh ssh = (Ssh)ctx;
8068
ecbb0000 8069 if (ssh->state == SSH_STATE_CLOSED)
8070 return;
8071
e6c1536e 8072 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9442dd57 8073 now - ssh->next_rekey >= 0) {
f382c87d 8074 do_ssh2_transport(ssh, "timeout", -1, NULL);
9442dd57 8075 }
8076}
8077
1c1a7262 8078static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
ff3187f6 8079 struct Packet *pktin)
7cca0d81 8080{
1c1a7262 8081 unsigned char *in = (unsigned char *)vin;
b09eaa88 8082 if (ssh->state == SSH_STATE_CLOSED)
8083 return;
8084
9442dd57 8085 if (pktin) {
8086 ssh->incoming_data_size += pktin->encrypted_len;
8087 if (!ssh->kex_in_progress &&
d57f70af 8088 ssh->max_data_size != 0 &&
8089 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 8090 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9442dd57 8091 }
8092
b09eaa88 8093 if (pktin && ssh->packet_dispatch[pktin->type]) {
8094 ssh->packet_dispatch[pktin->type](ssh, pktin);
32874aea 8095 return;
b09eaa88 8096 }
8097
8098 if (!ssh->protocol_initial_phase_done ||
8099 (pktin && pktin->type >= 20 && pktin->type < 50)) {
8100 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
8101 !ssh->protocol_initial_phase_done) {
8102 ssh->protocol_initial_phase_done = TRUE;
8103 /*
8104 * Allow authconn to initialise itself.
8105 */
8106 do_ssh2_authconn(ssh, NULL, 0, NULL);
8107 }
8108 } else {
8109 do_ssh2_authconn(ssh, in, inlen, pktin);
8110 }
7cca0d81 8111}
8112
8113/*
8df7a775 8114 * Called to set up the connection.
374330e2 8115 *
8116 * Returns an error message, or NULL on success.
374330e2 8117 */
cbe2d68f 8118static const char *ssh_init(void *frontend_handle, void **backend_handle,
8119 Config *cfg,
79bf227b 8120 char *host, int port, char **realhost, int nodelay,
8121 int keepalive)
32874aea 8122{
cbe2d68f 8123 const char *p;
51470298 8124 Ssh ssh;
8125
3d88e64d 8126 ssh = snew(struct ssh_tag);
86916870 8127 ssh->cfg = *cfg; /* STRUCTURE COPY */
125105d1 8128 ssh->version = 0; /* when not ready yet */
51470298 8129 ssh->s = NULL;
8130 ssh->cipher = NULL;
371e569c 8131 ssh->v1_cipher_ctx = NULL;
0183b242 8132 ssh->crcda_ctx = NULL;
51470298 8133 ssh->cscipher = NULL;
371e569c 8134 ssh->cs_cipher_ctx = NULL;
51470298 8135 ssh->sccipher = NULL;
371e569c 8136 ssh->sc_cipher_ctx = NULL;
51470298 8137 ssh->csmac = NULL;
a8327734 8138 ssh->cs_mac_ctx = NULL;
51470298 8139 ssh->scmac = NULL;
e0e1a00d 8140 ssh->sc_mac_ctx = NULL;
51470298 8141 ssh->cscomp = NULL;
5366aed8 8142 ssh->cs_comp_ctx = NULL;
51470298 8143 ssh->sccomp = NULL;
5366aed8 8144 ssh->sc_comp_ctx = NULL;
51470298 8145 ssh->kex = NULL;
389aa499 8146 ssh->kex_ctx = NULL;
51470298 8147 ssh->hostkey = NULL;
8148 ssh->exitcode = -1;
ac934965 8149 ssh->close_expected = FALSE;
9e296bfa 8150 ssh->clean_exit = FALSE;
51470298 8151 ssh->state = SSH_STATE_PREPACKET;
8152 ssh->size_needed = FALSE;
8153 ssh->eof_needed = FALSE;
b9d7bcad 8154 ssh->ldisc = NULL;
a8327734 8155 ssh->logctx = NULL;
51470298 8156 ssh->deferred_send_data = NULL;
8157 ssh->deferred_len = 0;
8158 ssh->deferred_size = 0;
8159 ssh->fallback_cmd = 0;
8160 ssh->pkt_ctx = 0;
302121de 8161 ssh->x11auth = NULL;
be738459 8162 ssh->v1_compressing = FALSE;
51470298 8163 ssh->v2_outgoing_sequence = 0;
8164 ssh->ssh1_rdpkt_crstate = 0;
8165 ssh->ssh2_rdpkt_crstate = 0;
8166 ssh->do_ssh_init_crstate = 0;
8167 ssh->ssh_gotdata_crstate = 0;
b09eaa88 8168 ssh->do_ssh1_connection_crstate = 0;
51470298 8169 ssh->do_ssh1_login_crstate = 0;
8170 ssh->do_ssh2_transport_crstate = 0;
8171 ssh->do_ssh2_authconn_crstate = 0;
8172 ssh->do_ssh_init_state = NULL;
8173 ssh->do_ssh1_login_state = NULL;
8174 ssh->do_ssh2_transport_state = NULL;
8175 ssh->do_ssh2_authconn_state = NULL;
4320baf7 8176 ssh->v_c = NULL;
8177 ssh->v_s = NULL;
6571dbfd 8178 ssh->mainchan = NULL;
968d2d92 8179 ssh->throttled_all = 0;
8180 ssh->v1_stdout_throttling = 0;
590f6a5f 8181 ssh->queue = NULL;
8182 ssh->queuelen = ssh->queuesize = 0;
8183 ssh->queueing = FALSE;
06fadff5 8184 ssh->qhead = ssh->qtail = NULL;
e13bba36 8185 ssh->deferred_rekey_reason = NULL;
3d9449a1 8186 bufchain_init(&ssh->queued_incoming_data);
8187 ssh->frozen = FALSE;
51470298 8188
8189 *backend_handle = ssh;
32874aea 8190
8f203108 8191#ifdef MSCRYPTOAPI
32874aea 8192 if (crypto_startup() == 0)
8f203108 8193 return "Microsoft high encryption pack not installed!";
8194#endif
374330e2 8195
51470298 8196 ssh->frontend = frontend_handle;
86916870 8197 ssh->term_width = ssh->cfg.width;
8198 ssh->term_height = ssh->cfg.height;
887035a5 8199
fabd1805 8200 ssh->channels = NULL;
8201 ssh->rportfwds = NULL;
f47a5ffb 8202 ssh->portfwds = NULL;
fabd1805 8203
51470298 8204 ssh->send_ok = 0;
8205 ssh->editing = 0;
8206 ssh->echoing = 0;
8207 ssh->v1_throttle_count = 0;
8208 ssh->overall_bufsize = 0;
8209 ssh->fallback_cmd = 0;
8df7a775 8210
3648d4c5 8211 ssh->protocol = NULL;
8212
b09eaa88 8213 ssh->protocol_initial_phase_done = FALSE;
8214
39934deb 8215 ssh->pinger = NULL;
8216
9442dd57 8217 ssh->incoming_data_size = ssh->outgoing_data_size =
8218 ssh->deferred_data_size = 0L;
d57f70af 8219 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9442dd57 8220 ssh->kex_in_progress = FALSE;
8221
79bf227b 8222 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
fb09bf1c 8223 if (p != NULL)
8224 return p;
374330e2 8225
5d17ccfc 8226 random_ref();
8227
374330e2 8228 return NULL;
8229}
8230
fabd1805 8231static void ssh_free(void *handle)
8232{
8233 Ssh ssh = (Ssh) handle;
8234 struct ssh_channel *c;
8235 struct ssh_rportfwd *pf;
8236
8237 if (ssh->v1_cipher_ctx)
8238 ssh->cipher->free_context(ssh->v1_cipher_ctx);
8239 if (ssh->cs_cipher_ctx)
8240 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
8241 if (ssh->sc_cipher_ctx)
8242 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
8243 if (ssh->cs_mac_ctx)
8244 ssh->csmac->free_context(ssh->cs_mac_ctx);
8245 if (ssh->sc_mac_ctx)
8246 ssh->scmac->free_context(ssh->sc_mac_ctx);
29b1d0b3 8247 if (ssh->cs_comp_ctx) {
8248 if (ssh->cscomp)
8249 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
8250 else
8251 zlib_compress_cleanup(ssh->cs_comp_ctx);
8252 }
8253 if (ssh->sc_comp_ctx) {
8254 if (ssh->sccomp)
8255 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
8256 else
8257 zlib_decompress_cleanup(ssh->sc_comp_ctx);
8258 }
fabd1805 8259 if (ssh->kex_ctx)
8260 dh_cleanup(ssh->kex_ctx);
8261 sfree(ssh->savedhost);
8262
590f6a5f 8263 while (ssh->queuelen-- > 0)
8264 ssh_free_packet(ssh->queue[ssh->queuelen]);
8265 sfree(ssh->queue);
8266
06fadff5 8267 while (ssh->qhead) {
8268 struct queued_handler *qh = ssh->qhead;
8269 ssh->qhead = qh->next;
8270 sfree(ssh->qhead);
8271 }
8272 ssh->qhead = ssh->qtail = NULL;
8273
fabd1805 8274 if (ssh->channels) {
8275 while ((c = delpos234(ssh->channels, 0)) != NULL) {
8276 switch (c->type) {
8277 case CHAN_X11:
8278 if (c->u.x11.s != NULL)
8279 x11_close(c->u.x11.s);
8280 break;
8281 case CHAN_SOCKDATA:
8282 if (c->u.pfd.s != NULL)
8283 pfd_close(c->u.pfd.s);
8284 break;
8285 }
8286 sfree(c);
8287 }
8288 freetree234(ssh->channels);
cdb52705 8289 ssh->channels = NULL;
fabd1805 8290 }
8291
8292 if (ssh->rportfwds) {
8293 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8294 sfree(pf);
8295 freetree234(ssh->rportfwds);
cdb52705 8296 ssh->rportfwds = NULL;
fabd1805 8297 }
8298 sfree(ssh->deferred_send_data);
8299 if (ssh->x11auth)
8300 x11_free_auth(ssh->x11auth);
8301 sfree(ssh->do_ssh_init_state);
8302 sfree(ssh->do_ssh1_login_state);
8303 sfree(ssh->do_ssh2_transport_state);
8304 sfree(ssh->do_ssh2_authconn_state);
4320baf7 8305 sfree(ssh->v_c);
8306 sfree(ssh->v_s);
679539d7 8307 if (ssh->crcda_ctx) {
8308 crcda_free_context(ssh->crcda_ctx);
8309 ssh->crcda_ctx = NULL;
8310 }
fabd1805 8311 if (ssh->s)
ac934965 8312 ssh_do_close(ssh, TRUE);
9442dd57 8313 expire_timer_context(ssh);
39934deb 8314 if (ssh->pinger)
8315 pinger_free(ssh->pinger);
3d9449a1 8316 bufchain_clear(&ssh->queued_incoming_data);
ee50e8b6 8317 sfree(ssh);
5d17ccfc 8318
8319 random_unref();
fabd1805 8320}
8321
374330e2 8322/*
86916870 8323 * Reconfigure the SSH backend.
86916870 8324 */
8325static void ssh_reconfig(void *handle, Config *cfg)
8326{
8327 Ssh ssh = (Ssh) handle;
e13bba36 8328 char *rekeying = NULL, rekey_mandatory = FALSE;
e6c1536e 8329 unsigned long old_max_data_size;
8330
39934deb 8331 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
3b6606c7 8332 if (ssh->portfwds)
8333 ssh_setup_portfwd(ssh, cfg);
e6c1536e 8334
8335 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8336 cfg->ssh_rekey_time != 0) {
8337 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8338 long now = GETTICKCOUNT();
8339
8340 if (new_next - now < 0) {
f382c87d 8341 rekeying = "timeout shortened";
e6c1536e 8342 } else {
8343 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8344 }
8345 }
8346
8347 old_max_data_size = ssh->max_data_size;
8348 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8349 if (old_max_data_size != ssh->max_data_size &&
8350 ssh->max_data_size != 0) {
8351 if (ssh->outgoing_data_size > ssh->max_data_size ||
8352 ssh->incoming_data_size > ssh->max_data_size)
f382c87d 8353 rekeying = "data limit lowered";
e6c1536e 8354 }
8355
e13bba36 8356 if (ssh->cfg.compression != cfg->compression) {
f382c87d 8357 rekeying = "compression setting changed";
e13bba36 8358 rekey_mandatory = TRUE;
8359 }
8360
8361 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8362 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8363 sizeof(ssh->cfg.ssh_cipherlist))) {
f382c87d 8364 rekeying = "cipher settings changed";
e13bba36 8365 rekey_mandatory = TRUE;
e6c1536e 8366 }
8367
86916870 8368 ssh->cfg = *cfg; /* STRUCTURE COPY */
e13bba36 8369
8370 if (rekeying) {
8371 if (!ssh->kex_in_progress) {
8372 do_ssh2_transport(ssh, rekeying, -1, NULL);
8373 } else if (rekey_mandatory) {
8374 ssh->deferred_rekey_reason = rekeying;
8375 }
8376 }
86916870 8377}
8378
8379/*
86dc445a 8380 * Called to send data down the SSH connection.
374330e2 8381 */
51470298 8382static int ssh_send(void *handle, char *buf, int len)
32874aea 8383{
51470298 8384 Ssh ssh = (Ssh) handle;
8385
8386 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 8387 return 0;
374330e2 8388
d8baa528 8389 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5471d09a 8390
51470298 8391 return ssh_sendbuffer(ssh);
5471d09a 8392}
8393
8394/*
8395 * Called to query the current amount of buffered stdin data.
8396 */
51470298 8397static int ssh_sendbuffer(void *handle)
5471d09a 8398{
51470298 8399 Ssh ssh = (Ssh) handle;
5471d09a 8400 int override_value;
8401
51470298 8402 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5471d09a 8403 return 0;
8404
8405 /*
8406 * If the SSH socket itself has backed up, add the total backup
8407 * size on that to any individual buffer on the stdin channel.
8408 */
8409 override_value = 0;
51470298 8410 if (ssh->throttled_all)
8411 override_value = ssh->overall_bufsize;
5471d09a 8412
51470298 8413 if (ssh->version == 1) {
5471d09a 8414 return override_value;
51470298 8415 } else if (ssh->version == 2) {
8416 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5471d09a 8417 return override_value;
8418 else
51470298 8419 return (override_value +
8420 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5471d09a 8421 }
8422
8423 return 0;
374330e2 8424}
8425
8426/*
6e48c3fe 8427 * Called to set the size of the window from SSH's POV.
374330e2 8428 */
51470298 8429static void ssh_size(void *handle, int width, int height)
32874aea 8430{
51470298 8431 Ssh ssh = (Ssh) handle;
ff3187f6 8432 struct Packet *pktout;
51470298 8433
8434 ssh->term_width = width;
8435 ssh->term_height = height;
f278d6f8 8436
51470298 8437 switch (ssh->state) {
374330e2 8438 case SSH_STATE_BEFORE_SIZE:
3687d221 8439 case SSH_STATE_PREPACKET:
21248260 8440 case SSH_STATE_CLOSED:
374330e2 8441 break; /* do nothing */
8442 case SSH_STATE_INTERMED:
51470298 8443 ssh->size_needed = TRUE; /* buffer for later */
374330e2 8444 break;
8445 case SSH_STATE_SESSION:
86916870 8446 if (!ssh->cfg.nopty) {
51470298 8447 if (ssh->version == 1) {
8448 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8449 PKT_INT, ssh->term_height,
8450 PKT_INT, ssh->term_width,
32874aea 8451 PKT_INT, 0, PKT_INT, 0, PKT_END);
0ed48730 8452 } else if (ssh->mainchan) {
ff3187f6 8453 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8454 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8455 ssh2_pkt_addstring(pktout, "window-change");
8456 ssh2_pkt_addbool(pktout, 0);
8457 ssh2_pkt_adduint32(pktout, ssh->term_width);
8458 ssh2_pkt_adduint32(pktout, ssh->term_height);
8459 ssh2_pkt_adduint32(pktout, 0);
8460 ssh2_pkt_adduint32(pktout, 0);
8461 ssh2_pkt_send(ssh, pktout);
32874aea 8462 }
8463 }
8464 break;
374330e2 8465 }
8466}
8467
8468/*
125105d1 8469 * Return a list of the special codes that make sense in this
8470 * protocol.
8471 */
8472static const struct telnet_special *ssh_get_specials(void *handle)
8473{
786ba75e 8474 static const struct telnet_special ssh1_ignore_special[] = {
8475 {"IGNORE message", TS_NOP}
8476 };
8477 static const struct telnet_special ssh2_transport_specials[] = {
62638676 8478 {"IGNORE message", TS_NOP},
9442dd57 8479 {"Repeat key exchange", TS_REKEY},
62638676 8480 };
8481 static const struct telnet_special ssh2_session_specials[] = {
6f2d0cde 8482 {NULL, TS_SEP},
8483 {"Break", TS_BRK},
786ba75e 8484 /* These are the signal names defined by draft-ietf-secsh-connect-23.
6f2d0cde 8485 * They include all the ISO C signals, but are a subset of the POSIX
8486 * required signals. */
8487 {"SIGINT (Interrupt)", TS_SIGINT},
8488 {"SIGTERM (Terminate)", TS_SIGTERM},
8489 {"SIGKILL (Kill)", TS_SIGKILL},
8490 {"SIGQUIT (Quit)", TS_SIGQUIT},
8491 {"SIGHUP (Hangup)", TS_SIGHUP},
8492 {"More signals", TS_SUBMENU},
8493 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8494 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8495 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8496 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8497 {NULL, TS_EXITMENU}
62638676 8498 };
8499 static const struct telnet_special specials_end[] = {
6f2d0cde 8500 {NULL, TS_EXITMENU}
62638676 8501 };
786ba75e 8502 /* XXX review this length for any changes: */
8503 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
62638676 8504 lenof(ssh2_session_specials) +
8505 lenof(specials_end)];
125105d1 8506 Ssh ssh = (Ssh) handle;
62638676 8507 int i = 0;
8508#define ADD_SPECIALS(name) \
8509 do { \
8510 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8511 memcpy(&ssh_specials[i], name, sizeof name); \
8512 i += lenof(name); \
8513 } while(0)
125105d1 8514
8515 if (ssh->version == 1) {
62638676 8516 /* Don't bother offering IGNORE if we've decided the remote
8517 * won't cope with it, since we wouldn't bother sending it if
8518 * asked anyway. */
8519 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
786ba75e 8520 ADD_SPECIALS(ssh1_ignore_special);
125105d1 8521 } else if (ssh->version == 2) {
786ba75e 8522 ADD_SPECIALS(ssh2_transport_specials);
62638676 8523 if (ssh->mainchan)
8524 ADD_SPECIALS(ssh2_session_specials);
8525 } /* else we're not ready yet */
8526
8527 if (i) {
8528 ADD_SPECIALS(specials_end);
8529 return ssh_specials;
8530 } else {
125105d1 8531 return NULL;
62638676 8532 }
8533#undef ADD_SPECIALS
125105d1 8534}
8535
8536/*
86dc445a 8537 * Send special codes. TS_EOF is useful for `plink', so you
6abbf9e3 8538 * can send an EOF and collect resulting output (e.g. `plink
8539 * hostname sort').
374330e2 8540 */
51470298 8541static void ssh_special(void *handle, Telnet_Special code)
32874aea 8542{
51470298 8543 Ssh ssh = (Ssh) handle;
ff3187f6 8544 struct Packet *pktout;
51470298 8545
6abbf9e3 8546 if (code == TS_EOF) {
51470298 8547 if (ssh->state != SSH_STATE_SESSION) {
32874aea 8548 /*
8549 * Buffer the EOF in case we are pre-SESSION, so we can
8550 * send it as soon as we reach SESSION.
8551 */
8552 if (code == TS_EOF)
51470298 8553 ssh->eof_needed = TRUE;
32874aea 8554 return;
8555 }
51470298 8556 if (ssh->version == 1) {
8557 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
0ed48730 8558 } else if (ssh->mainchan) {
ff3187f6 8559 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8560 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8561 ssh2_pkt_send(ssh, pktout);
00a0b113 8562 ssh->send_ok = 0; /* now stop trying to read from stdin */
32874aea 8563 }
8564 logevent("Sent EOF message");
125105d1 8565 } else if (code == TS_PING || code == TS_NOP) {
51470298 8566 if (ssh->state == SSH_STATE_CLOSED
8567 || ssh->state == SSH_STATE_PREPACKET) return;
8568 if (ssh->version == 1) {
8569 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8570 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
32874aea 8571 } else {
ff3187f6 8572 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8573 ssh2_pkt_addstring_start(pktout);
590f6a5f 8574 ssh2_pkt_send_noqueue(ssh, pktout);
32874aea 8575 }
9442dd57 8576 } else if (code == TS_REKEY) {
8577 if (!ssh->kex_in_progress && ssh->version == 2) {
f382c87d 8578 do_ssh2_transport(ssh, "at user request", -1, NULL);
9442dd57 8579 }
125105d1 8580 } else if (code == TS_BRK) {
8581 if (ssh->state == SSH_STATE_CLOSED
8582 || ssh->state == SSH_STATE_PREPACKET) return;
8583 if (ssh->version == 1) {
2e85c969 8584 logevent("Unable to send BREAK signal in SSH-1");
0ed48730 8585 } else if (ssh->mainchan) {
ff3187f6 8586 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8587 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8588 ssh2_pkt_addstring(pktout, "break");
8589 ssh2_pkt_addbool(pktout, 0);
8590 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8591 ssh2_pkt_send(ssh, pktout);
125105d1 8592 }
6abbf9e3 8593 } else {
6f2d0cde 8594 /* Is is a POSIX signal? */
8595 char *signame = NULL;
8596 if (code == TS_SIGABRT) signame = "ABRT";
8597 if (code == TS_SIGALRM) signame = "ALRM";
8598 if (code == TS_SIGFPE) signame = "FPE";
8599 if (code == TS_SIGHUP) signame = "HUP";
8600 if (code == TS_SIGILL) signame = "ILL";
8601 if (code == TS_SIGINT) signame = "INT";
8602 if (code == TS_SIGKILL) signame = "KILL";
8603 if (code == TS_SIGPIPE) signame = "PIPE";
8604 if (code == TS_SIGQUIT) signame = "QUIT";
8605 if (code == TS_SIGSEGV) signame = "SEGV";
8606 if (code == TS_SIGTERM) signame = "TERM";
8607 if (code == TS_SIGUSR1) signame = "USR1";
8608 if (code == TS_SIGUSR2) signame = "USR2";
8609 /* The SSH-2 protocol does in principle support arbitrary named
8610 * signals, including signame@domain, but we don't support those. */
8611 if (signame) {
8612 /* It's a signal. */
8613 if (ssh->version == 2 && ssh->mainchan) {
ff3187f6 8614 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8615 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8616 ssh2_pkt_addstring(pktout, "signal");
8617 ssh2_pkt_addbool(pktout, 0);
8618 ssh2_pkt_addstring(pktout, signame);
8619 ssh2_pkt_send(ssh, pktout);
6f2d0cde 8620 logeventf(ssh, "Sent signal SIG%s", signame);
8621 }
8622 } else {
8623 /* Never heard of it. Do nothing */
8624 }
6abbf9e3 8625 }
374330e2 8626}
8627
51470298 8628void *new_sock_channel(void *handle, Socket s)
d74d141c 8629{
51470298 8630 Ssh ssh = (Ssh) handle;
d74d141c 8631 struct ssh_channel *c;
3d88e64d 8632 c = snew(struct ssh_channel);
51470298 8633 c->ssh = ssh;
d74d141c 8634
8635 if (c) {
64d6ff88 8636 c->halfopen = TRUE;
51470298 8637 c->localid = alloc_channel_id(ssh);
d74d141c 8638 c->closes = 0;
bc240b21 8639 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
d74d141c 8640 c->u.pfd.s = s;
013dd8c0 8641 bufchain_init(&c->v.v2.outbuffer);
51470298 8642 add234(ssh->channels, c);
d74d141c 8643 }
8644 return c;
8645}
8646
5471d09a 8647/*
8648 * This is called when stdout/stderr (the entity to which
8649 * from_backend sends data) manages to clear some backlog.
8650 */
ae9ae89f 8651static void ssh_unthrottle(void *handle, int bufsize)
5471d09a 8652{
51470298 8653 Ssh ssh = (Ssh) handle;
8654 if (ssh->version == 1) {
8655 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8656 ssh->v1_stdout_throttling = 0;
8657 ssh1_throttle(ssh, -1);
5471d09a 8658 }
8659 } else {
51470298 8660 if (ssh->mainchan && ssh->mainchan->closes == 0)
8661 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5471d09a 8662 }
8663}
8664
6b78788a 8665void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
d74d141c 8666{
8667 struct ssh_channel *c = (struct ssh_channel *)channel;
6b78788a 8668 Ssh ssh = c->ssh;
ff3187f6 8669 struct Packet *pktout;
d74d141c 8670
57356d63 8671 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
d74d141c 8672
51470298 8673 if (ssh->version == 1) {
8674 send_packet(ssh, SSH1_MSG_PORT_OPEN,
bc240b21 8675 PKT_INT, c->localid,
8676 PKT_STR, hostname,
8677 PKT_INT, port,
31fb1866 8678 /* PKT_STR, <org:orgport>, */
bc240b21 8679 PKT_END);
8680 } else {
ff3187f6 8681 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8682 ssh2_pkt_addstring(pktout, "direct-tcpip");
8683 ssh2_pkt_adduint32(pktout, c->localid);
5471d09a 8684 c->v.v2.locwindow = OUR_V2_WINSIZE;
ff3187f6 8685 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
954d5c5a 8686 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
ff3187f6 8687 ssh2_pkt_addstring(pktout, hostname);
8688 ssh2_pkt_adduint32(pktout, port);
bc240b21 8689 /*
8690 * We make up values for the originator data; partly it's
8691 * too much hassle to keep track, and partly I'm not
8692 * convinced the server should be told details like that
8693 * about my local network configuration.
1f182589 8694 * The "originator IP address" is syntactically a numeric
8695 * IP address, and some servers (e.g., Tectia) get upset
8696 * if it doesn't match this syntax.
bc240b21 8697 */
1f182589 8698 ssh2_pkt_addstring(pktout, "0.0.0.0");
ff3187f6 8699 ssh2_pkt_adduint32(pktout, 0);
8700 ssh2_pkt_send(ssh, pktout);
bc240b21 8701 }
d74d141c 8702}
8703
51470298 8704static Socket ssh_socket(void *handle)
32874aea 8705{
51470298 8706 Ssh ssh = (Ssh) handle;
8707 return ssh->s;
32874aea 8708}
8ccc75b0 8709
51470298 8710static int ssh_sendok(void *handle)
32874aea 8711{
51470298 8712 Ssh ssh = (Ssh) handle;
8713 return ssh->send_ok;
32874aea 8714}
fb09bf1c 8715
51470298 8716static int ssh_ldisc(void *handle, int option)
32874aea 8717{
51470298 8718 Ssh ssh = (Ssh) handle;
32874aea 8719 if (option == LD_ECHO)
51470298 8720 return ssh->echoing;
32874aea 8721 if (option == LD_EDIT)
51470298 8722 return ssh->editing;
0965bee0 8723 return FALSE;
8724}
8725
b9d7bcad 8726static void ssh_provide_ldisc(void *handle, void *ldisc)
8727{
8728 Ssh ssh = (Ssh) handle;
8729 ssh->ldisc = ldisc;
8730}
8731
a8327734 8732static void ssh_provide_logctx(void *handle, void *logctx)
8733{
8734 Ssh ssh = (Ssh) handle;
8735 ssh->logctx = logctx;
8736}
8737
51470298 8738static int ssh_return_exitcode(void *handle)
8739{
8740 Ssh ssh = (Ssh) handle;
3bb2f322 8741 if (ssh->s != NULL)
8742 return -1;
8743 else
8744 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
51470298 8745}
8746
8747/*
f89c3294 8748 * cfg_info for SSH is the currently running version of the
8749 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8750 */
8751static int ssh_cfg_info(void *handle)
8752{
8753 Ssh ssh = (Ssh) handle;
8754 return ssh->version;
8755}
8756
8757/*
51470298 8758 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8759 * that fails. This variable is the means by which scp.c can reach
8760 * into the SSH code and find out which one it got.
8761 */
8762extern int ssh_fallback_cmd(void *handle)
d8d6c7e5 8763{
51470298 8764 Ssh ssh = (Ssh) handle;
8765 return ssh->fallback_cmd;
d8d6c7e5 8766}
8767
374330e2 8768Backend ssh_backend = {
8769 ssh_init,
fabd1805 8770 ssh_free,
86916870 8771 ssh_reconfig,
374330e2 8772 ssh_send,
5471d09a 8773 ssh_sendbuffer,
374330e2 8774 ssh_size,
4017be6d 8775 ssh_special,
125105d1 8776 ssh_get_specials,
8ccc75b0 8777 ssh_socket,
d8d6c7e5 8778 ssh_return_exitcode,
97db3be4 8779 ssh_sendok,
0965bee0 8780 ssh_ldisc,
b9d7bcad 8781 ssh_provide_ldisc,
a8327734 8782 ssh_provide_logctx,
5471d09a 8783 ssh_unthrottle,
f89c3294 8784 ssh_cfg_info,
97db3be4 8785 22
bc240b21 8786};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator