Missing argument in MALLOC_LOG version of snrealloc() macro.
[u/mdw/putty] / ssh.c
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <stdarg.h>
4 #include <assert.h>
5
6 #include "putty.h"
7 #include "tree234.h"
8 #include "ssh.h"
9
10 #ifndef FALSE
11 #define FALSE 0
12 #endif
13 #ifndef TRUE
14 #define TRUE 1
15 #endif
16
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 */
63 /* Mask for protoflags we will echo back to server if seen */
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 */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
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
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 */
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_KEX_MASK 0x000F
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
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 */
130
131 static const char *const ssh2_disconnect_reasons[] = {
132 NULL,
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
148 };
149
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 */
154
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
156
157 /*
158 * Various remote-bug flags.
159 */
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_REKEY 64
167 #define BUG_SSH2_PK_SESSIONID 128
168
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 */
175 static 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. */
245 static 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 }
257 static 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
273 #define translate(x) if (type == x) return #x
274 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
275 static char *ssh1_pkt_type(int type)
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 }
320 static char *ssh2_pkt_type(int pkt_ctx, int type)
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);
330 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
331 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
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
362
363 /* Enumeration values for fields in SSH-1 packets */
364 enum {
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 };
370
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.
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'.
390 */
391 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
392 #define crState(t) \
393 struct t *s; \
394 if (!ssh->t) ssh->t = snew(struct t); \
395 s = ssh->t;
396 #define crFinish(z) } *crLine = 0; return (z); }
397 #define crFinishV } *crLine = 0; return; }
398 #define crReturn(z) \
399 do {\
400 *crLine =__LINE__; return (z); case __LINE__:;\
401 } while (0)
402 #define crReturnV \
403 do {\
404 *crLine=__LINE__; return; case __LINE__:;\
405 } while (0)
406 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
407 #define crStopV do{ *crLine = 0; return; }while(0)
408 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
409 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
410
411 typedef struct ssh_tag *Ssh;
412 struct Packet;
413
414 static struct Packet *ssh1_pkt_init(int pkt_type);
415 static struct Packet *ssh2_pkt_init(int pkt_type);
416 static void ssh_pkt_ensure(struct Packet *, int length);
417 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
418 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
419 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
420 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
421 static void ssh_pkt_addstring_start(struct Packet *);
422 static void ssh_pkt_addstring_str(struct Packet *, char *data);
423 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
424 static void ssh_pkt_addstring(struct Packet *, char *data);
425 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
426 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
427 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
428 static int ssh2_pkt_construct(Ssh, struct Packet *);
429 static void ssh2_pkt_send(Ssh, struct Packet *);
430 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
431 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
432 struct Packet *pktin);
433 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
434 struct Packet *pktin);
435
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
442 * connection (in SSH-1 only). Throttling the whole connection is
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
449 * thankfully unlikely in SSH-2 since the window mechanism should
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 *
453 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
454 * channels.
455 */
456
457 #define SSH1_BUFFER_LIMIT 32768
458 #define SSH_MAX_BACKLOG 32768
459 #define OUR_V2_WINSIZE 16384
460 #define OUR_V2_MAXPKT 0x4000UL
461
462 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
463
464 const static struct ssh_mac *macs[] = {
465 &ssh_sha1, &ssh_md5
466 };
467 const static struct ssh_mac *buggymacs[] = {
468 &ssh_sha1_buggy, &ssh_md5
469 };
470
471 static void *ssh_comp_none_init(void)
472 {
473 return NULL;
474 }
475 static void ssh_comp_none_cleanup(void *handle)
476 {
477 }
478 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
479 unsigned char **outblock, int *outlen)
480 {
481 return 0;
482 }
483 static int ssh_comp_none_disable(void *handle)
484 {
485 return 0;
486 }
487 const static struct ssh_compress ssh_comp_none = {
488 "none",
489 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
490 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
491 ssh_comp_none_disable, NULL
492 };
493 extern const struct ssh_compress ssh_zlib;
494 const static struct ssh_compress *compressions[] = {
495 &ssh_zlib, &ssh_comp_none
496 };
497
498 enum { /* channel types */
499 CHAN_MAINSESSION,
500 CHAN_X11,
501 CHAN_AGENT,
502 CHAN_SOCKDATA,
503 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
504 };
505
506 /*
507 * 2-3-4 tree storing channels.
508 */
509 struct ssh_channel {
510 Ssh ssh; /* pointer back to main context */
511 unsigned remoteid, localid;
512 int type;
513 /* True if we opened this channel but server hasn't confirmed. */
514 int halfopen;
515 /*
516 * In SSH-1, this value contains four bits:
517 *
518 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
519 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
520 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
521 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
522 *
523 * A channel is completely finished with when all four bits are set.
524 */
525 int closes;
526 union {
527 struct ssh1_data_channel {
528 int throttling;
529 } v1;
530 struct ssh2_data_channel {
531 bufchain outbuffer;
532 unsigned remwindow, remmaxpkt;
533 unsigned locwindow;
534 } v2;
535 } v;
536 union {
537 struct ssh_agent_channel {
538 unsigned char *message;
539 unsigned char msglen[4];
540 unsigned lensofar, totallen;
541 } a;
542 struct ssh_x11_channel {
543 Socket s;
544 } x11;
545 struct ssh_pfd_channel {
546 Socket s;
547 } pfd;
548 } u;
549 };
550
551 /*
552 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
553 * use this structure in different ways, reflecting SSH-2's
554 * altogether saner approach to port forwarding.
555 *
556 * In SSH-1, you arrange a remote forwarding by sending the server
557 * the remote port number, and the local destination host:port.
558 * When a connection comes in, the server sends you back that
559 * host:port pair, and you connect to it. This is a ready-made
560 * security hole if you're not on the ball: a malicious server
561 * could send you back _any_ host:port pair, so if you trustingly
562 * connect to the address it gives you then you've just opened the
563 * entire inside of your corporate network just by connecting
564 * through it to a dodgy SSH server. Hence, we must store a list of
565 * host:port pairs we _are_ trying to forward to, and reject a
566 * connection request from the server if it's not in the list.
567 *
568 * In SSH-2, each side of the connection minds its own business and
569 * doesn't send unnecessary information to the other. You arrange a
570 * remote forwarding by sending the server just the remote port
571 * number. When a connection comes in, the server tells you which
572 * of its ports was connected to; and _you_ have to remember what
573 * local host:port pair went with that port number.
574 *
575 * Hence, in SSH-1 this structure is indexed by destination
576 * host:port pair, whereas in SSH-2 it is indexed by source port.
577 */
578 struct ssh_portfwd; /* forward declaration */
579
580 struct ssh_rportfwd {
581 unsigned sport, dport;
582 char dhost[256];
583 char *sportdesc;
584 struct ssh_portfwd *pfrec;
585 };
586 #define free_rportfwd(pf) ( \
587 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
588
589 /*
590 * Separately to the rportfwd tree (which is for looking up port
591 * open requests from the server), a tree of _these_ structures is
592 * used to keep track of all the currently open port forwardings,
593 * so that we can reconfigure in mid-session if the user requests
594 * it.
595 */
596 struct ssh_portfwd {
597 enum { DESTROY, KEEP, CREATE } status;
598 int type;
599 unsigned sport, dport;
600 char *saddr, *daddr;
601 char *sserv, *dserv;
602 struct ssh_rportfwd *remote;
603 int addressfamily;
604 void *local;
605 };
606 #define free_portfwd(pf) ( \
607 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
608 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
609
610 struct Packet {
611 long length; /* length of `data' actually used */
612 long forcepad; /* SSH-2: force padding to at least this length */
613 int type; /* only used for incoming packets */
614 unsigned long sequence; /* SSH-2 incoming sequence number */
615 unsigned char *data; /* allocated storage */
616 unsigned char *body; /* offset of payload within `data' */
617 long savedpos; /* temporary index into `data' (for strings) */
618 long maxlen; /* amount of storage allocated for `data' */
619 long encrypted_len; /* for SSH-2 total-size counting */
620
621 /*
622 * State associated with packet logging
623 */
624 int logmode;
625 int nblanks;
626 struct logblank_t *blanks;
627 };
628
629 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
630 struct Packet *pktin);
631 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
632 struct Packet *pktin);
633 static void ssh1_protocol_setup(Ssh ssh);
634 static void ssh2_protocol_setup(Ssh ssh);
635 static void ssh_size(void *handle, int width, int height);
636 static void ssh_special(void *handle, Telnet_Special);
637 static int ssh2_try_send(struct ssh_channel *c);
638 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
639 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
640 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
641 static int ssh_sendbuffer(void *handle);
642 static int ssh_do_close(Ssh ssh, int notify_exit);
643 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
644 static int ssh2_pkt_getbool(struct Packet *pkt);
645 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
646 static void ssh2_timer(void *ctx, long now);
647 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
648 struct Packet *pktin);
649
650 struct rdpkt1_state_tag {
651 long len, pad, biglen, to_read;
652 unsigned long realcrc, gotcrc;
653 unsigned char *p;
654 int i;
655 int chunk;
656 struct Packet *pktin;
657 };
658
659 struct rdpkt2_state_tag {
660 long len, pad, payload, packetlen, maclen;
661 int i;
662 int cipherblk;
663 unsigned long incoming_sequence;
664 struct Packet *pktin;
665 };
666
667 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
668 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
669
670 struct queued_handler;
671 struct queued_handler {
672 int msg1, msg2;
673 chandler_fn_t handler;
674 void *ctx;
675 struct queued_handler *next;
676 };
677
678 struct ssh_tag {
679 const struct plug_function_table *fn;
680 /* the above field _must_ be first in the structure */
681
682 SHA_State exhash, exhashbase;
683
684 Socket s;
685
686 void *ldisc;
687 void *logctx;
688
689 unsigned char session_key[32];
690 int v1_compressing;
691 int v1_remote_protoflags;
692 int v1_local_protoflags;
693 int agentfwd_enabled;
694 int X11_fwd_enabled;
695 int remote_bugs;
696 const struct ssh_cipher *cipher;
697 void *v1_cipher_ctx;
698 void *crcda_ctx;
699 const struct ssh2_cipher *cscipher, *sccipher;
700 void *cs_cipher_ctx, *sc_cipher_ctx;
701 const struct ssh_mac *csmac, *scmac;
702 void *cs_mac_ctx, *sc_mac_ctx;
703 const struct ssh_compress *cscomp, *sccomp;
704 void *cs_comp_ctx, *sc_comp_ctx;
705 const struct ssh_kex *kex;
706 const struct ssh_signkey *hostkey;
707 unsigned char v2_session_id[20];
708 void *kex_ctx;
709
710 char *savedhost;
711 int savedport;
712 int send_ok;
713 int echoing, editing;
714
715 void *frontend;
716
717 int ospeed, ispeed; /* temporaries */
718 int term_width, term_height;
719
720 tree234 *channels; /* indexed by local id */
721 struct ssh_channel *mainchan; /* primary session channel */
722 int exitcode;
723 int close_expected;
724 int clean_exit;
725
726 tree234 *rportfwds, *portfwds;
727
728 enum {
729 SSH_STATE_PREPACKET,
730 SSH_STATE_BEFORE_SIZE,
731 SSH_STATE_INTERMED,
732 SSH_STATE_SESSION,
733 SSH_STATE_CLOSED
734 } state;
735
736 int size_needed, eof_needed;
737
738 struct Packet **queue;
739 int queuelen, queuesize;
740 int queueing;
741 unsigned char *deferred_send_data;
742 int deferred_len, deferred_size;
743
744 /*
745 * Gross hack: pscp will try to start SFTP but fall back to
746 * scp1 if that fails. This variable is the means by which
747 * scp.c can reach into the SSH code and find out which one it
748 * got.
749 */
750 int fallback_cmd;
751
752 bufchain banner; /* accumulates banners during do_ssh2_authconn */
753 /*
754 * Used for username and password input.
755 */
756 char *userpass_input_buffer;
757 int userpass_input_buflen;
758 int userpass_input_bufpos;
759 int userpass_input_echo;
760
761 int pkt_ctx;
762
763 void *x11auth;
764
765 int version;
766 int v1_throttle_count;
767 int overall_bufsize;
768 int throttled_all;
769 int v1_stdout_throttling;
770 unsigned long v2_outgoing_sequence;
771
772 int ssh1_rdpkt_crstate;
773 int ssh2_rdpkt_crstate;
774 int do_ssh_init_crstate;
775 int ssh_gotdata_crstate;
776 int do_ssh1_login_crstate;
777 int do_ssh1_connection_crstate;
778 int do_ssh2_transport_crstate;
779 int do_ssh2_authconn_crstate;
780
781 void *do_ssh_init_state;
782 void *do_ssh1_login_state;
783 void *do_ssh2_transport_state;
784 void *do_ssh2_authconn_state;
785
786 struct rdpkt1_state_tag rdpkt1_state;
787 struct rdpkt2_state_tag rdpkt2_state;
788
789 /* SSH-1 and SSH-2 use this for different things, but both use it */
790 int protocol_initial_phase_done;
791
792 void (*protocol) (Ssh ssh, void *vin, int inlen,
793 struct Packet *pkt);
794 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
795
796 /*
797 * We maintain a full _copy_ of a Config structure here, not
798 * merely a pointer to it. That way, when we're passed a new
799 * one for reconfiguration, we can check the differences and
800 * potentially reconfigure port forwardings etc in mid-session.
801 */
802 Config cfg;
803
804 /*
805 * Used to transfer data back from async callbacks.
806 */
807 void *agent_response;
808 int agent_response_len;
809 int user_response;
810
811 /*
812 * The SSH connection can be set as `frozen', meaning we are
813 * not currently accepting incoming data from the network. This
814 * is slightly more serious than setting the _socket_ as
815 * frozen, because we may already have had data passed to us
816 * from the network which we need to delay processing until
817 * after the freeze is lifted, so we also need a bufchain to
818 * store that data.
819 */
820 int frozen;
821 bufchain queued_incoming_data;
822
823 /*
824 * Dispatch table for packet types that we may have to deal
825 * with at any time.
826 */
827 handler_fn_t packet_dispatch[256];
828
829 /*
830 * Queues of one-off handler functions for success/failure
831 * indications from a request.
832 */
833 struct queued_handler *qhead, *qtail;
834
835 /*
836 * This module deals with sending keepalives.
837 */
838 Pinger pinger;
839
840 /*
841 * Track incoming and outgoing data sizes and time, for
842 * size-based rekeys.
843 */
844 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
845 unsigned long max_data_size;
846 int kex_in_progress;
847 long next_rekey, last_rekey;
848 char *deferred_rekey_reason; /* points to STATIC string; don't free */
849 };
850
851 #define logevent(s) logevent(ssh->frontend, s)
852
853 /* logevent, only printf-formatted. */
854 static void logeventf(Ssh ssh, const char *fmt, ...)
855 {
856 va_list ap;
857 char *buf;
858
859 va_start(ap, fmt);
860 buf = dupvprintf(fmt, ap);
861 va_end(ap);
862 logevent(buf);
863 sfree(buf);
864 }
865
866 #define bombout(msg) \
867 do { \
868 char *text = dupprintf msg; \
869 ssh_do_close(ssh, FALSE); \
870 logevent(text); \
871 connection_fatal(ssh->frontend, "%s", text); \
872 sfree(text); \
873 } while (0)
874
875 /* Functions to leave bits out of the SSH packet log file. */
876
877 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
878 {
879 if (ssh->cfg.logomitpass)
880 pkt->logmode = blanktype;
881 }
882
883 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
884 {
885 if (ssh->cfg.logomitdata)
886 pkt->logmode = blanktype;
887 }
888
889 static void end_log_omission(Ssh ssh, struct Packet *pkt)
890 {
891 pkt->logmode = PKTLOG_EMIT;
892 }
893
894 /* Helper function for common bits of parsing cfg.ttymodes. */
895 static void parse_ttymodes(Ssh ssh, char *modes,
896 void (*do_mode)(void *data, char *mode, char *val),
897 void *data)
898 {
899 while (*modes) {
900 char *t = strchr(modes, '\t');
901 char *m = snewn(t-modes+1, char);
902 char *val;
903 strncpy(m, modes, t-modes);
904 m[t-modes] = '\0';
905 if (*(t+1) == 'A')
906 val = get_ttymode(ssh->frontend, m);
907 else
908 val = dupstr(t+2);
909 if (val)
910 do_mode(data, m, val);
911 sfree(m);
912 sfree(val);
913 modes += strlen(modes) + 1;
914 }
915 }
916
917 static int ssh_channelcmp(void *av, void *bv)
918 {
919 struct ssh_channel *a = (struct ssh_channel *) av;
920 struct ssh_channel *b = (struct ssh_channel *) bv;
921 if (a->localid < b->localid)
922 return -1;
923 if (a->localid > b->localid)
924 return +1;
925 return 0;
926 }
927 static int ssh_channelfind(void *av, void *bv)
928 {
929 unsigned *a = (unsigned *) av;
930 struct ssh_channel *b = (struct ssh_channel *) bv;
931 if (*a < b->localid)
932 return -1;
933 if (*a > b->localid)
934 return +1;
935 return 0;
936 }
937
938 static int ssh_rportcmp_ssh1(void *av, void *bv)
939 {
940 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
941 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
942 int i;
943 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
944 return i < 0 ? -1 : +1;
945 if (a->dport > b->dport)
946 return +1;
947 if (a->dport < b->dport)
948 return -1;
949 return 0;
950 }
951
952 static int ssh_rportcmp_ssh2(void *av, void *bv)
953 {
954 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
955 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
956
957 if (a->sport > b->sport)
958 return +1;
959 if (a->sport < b->sport)
960 return -1;
961 return 0;
962 }
963
964 /*
965 * Special form of strcmp which can cope with NULL inputs. NULL is
966 * defined to sort before even the empty string.
967 */
968 static int nullstrcmp(const char *a, const char *b)
969 {
970 if (a == NULL && b == NULL)
971 return 0;
972 if (a == NULL)
973 return -1;
974 if (b == NULL)
975 return +1;
976 return strcmp(a, b);
977 }
978
979 static int ssh_portcmp(void *av, void *bv)
980 {
981 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
982 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
983 int i;
984 if (a->type > b->type)
985 return +1;
986 if (a->type < b->type)
987 return -1;
988 if (a->addressfamily > b->addressfamily)
989 return +1;
990 if (a->addressfamily < b->addressfamily)
991 return -1;
992 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
993 return i < 0 ? -1 : +1;
994 if (a->sport > b->sport)
995 return +1;
996 if (a->sport < b->sport)
997 return -1;
998 if (a->type != 'D') {
999 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1000 return i < 0 ? -1 : +1;
1001 if (a->dport > b->dport)
1002 return +1;
1003 if (a->dport < b->dport)
1004 return -1;
1005 }
1006 return 0;
1007 }
1008
1009 static int alloc_channel_id(Ssh ssh)
1010 {
1011 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1012 unsigned low, high, mid;
1013 int tsize;
1014 struct ssh_channel *c;
1015
1016 /*
1017 * First-fit allocation of channel numbers: always pick the
1018 * lowest unused one. To do this, binary-search using the
1019 * counted B-tree to find the largest channel ID which is in a
1020 * contiguous sequence from the beginning. (Precisely
1021 * everything in that sequence must have ID equal to its tree
1022 * index plus CHANNEL_NUMBER_OFFSET.)
1023 */
1024 tsize = count234(ssh->channels);
1025
1026 low = -1;
1027 high = tsize;
1028 while (high - low > 1) {
1029 mid = (high + low) / 2;
1030 c = index234(ssh->channels, mid);
1031 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1032 low = mid; /* this one is fine */
1033 else
1034 high = mid; /* this one is past it */
1035 }
1036 /*
1037 * Now low points to either -1, or the tree index of the
1038 * largest ID in the initial sequence.
1039 */
1040 {
1041 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1042 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1043 }
1044 return low + 1 + CHANNEL_NUMBER_OFFSET;
1045 }
1046
1047 static void c_write(Ssh ssh, const char *buf, int len)
1048 {
1049 if ((flags & FLAG_STDERR)) {
1050 int i;
1051 for (i = 0; i < len; i++)
1052 if (buf[i] != '\r')
1053 fputc(buf[i], stderr);
1054 return;
1055 }
1056 from_backend(ssh->frontend, 1, buf, len);
1057 }
1058
1059 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1060 {
1061 int i;
1062 for (i = 0; i < len; i++) {
1063 if (buf[i] == '\n')
1064 c_write(ssh, "\r\n", 2);
1065 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
1066 c_write(ssh, buf + i, 1);
1067 }
1068 }
1069
1070 static void c_write_str(Ssh ssh, const char *buf)
1071 {
1072 c_write(ssh, buf, strlen(buf));
1073 }
1074
1075 static void ssh_free_packet(struct Packet *pkt)
1076 {
1077 sfree(pkt->data);
1078 sfree(pkt);
1079 }
1080 static struct Packet *ssh_new_packet(void)
1081 {
1082 struct Packet *pkt = snew(struct Packet);
1083
1084 pkt->body = pkt->data = NULL;
1085 pkt->maxlen = 0;
1086 pkt->logmode = PKTLOG_EMIT;
1087 pkt->nblanks = 0;
1088 pkt->blanks = NULL;
1089
1090 return pkt;
1091 }
1092
1093 /*
1094 * Collect incoming data in the incoming packet buffer.
1095 * Decipher and verify the packet when it is completely read.
1096 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1097 * Update the *data and *datalen variables.
1098 * Return a Packet structure when a packet is completed.
1099 */
1100 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1101 {
1102 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1103
1104 crBegin(ssh->ssh1_rdpkt_crstate);
1105
1106 st->pktin = ssh_new_packet();
1107
1108 st->pktin->type = 0;
1109 st->pktin->length = 0;
1110
1111 for (st->i = st->len = 0; st->i < 4; st->i++) {
1112 while ((*datalen) == 0)
1113 crReturn(NULL);
1114 st->len = (st->len << 8) + **data;
1115 (*data)++, (*datalen)--;
1116 }
1117
1118 st->pad = 8 - (st->len % 8);
1119 st->biglen = st->len + st->pad;
1120 st->pktin->length = st->len - 5;
1121
1122 if (st->biglen < 0) {
1123 bombout(("Extremely large packet length from server suggests"
1124 " data stream corruption"));
1125 ssh_free_packet(st->pktin);
1126 crStop(NULL);
1127 }
1128
1129 st->pktin->maxlen = st->biglen;
1130 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1131
1132 st->to_read = st->biglen;
1133 st->p = st->pktin->data;
1134 while (st->to_read > 0) {
1135 st->chunk = st->to_read;
1136 while ((*datalen) == 0)
1137 crReturn(NULL);
1138 if (st->chunk > (*datalen))
1139 st->chunk = (*datalen);
1140 memcpy(st->p, *data, st->chunk);
1141 *data += st->chunk;
1142 *datalen -= st->chunk;
1143 st->p += st->chunk;
1144 st->to_read -= st->chunk;
1145 }
1146
1147 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1148 st->biglen, NULL)) {
1149 bombout(("Network attack (CRC compensation) detected!"));
1150 ssh_free_packet(st->pktin);
1151 crStop(NULL);
1152 }
1153
1154 if (ssh->cipher)
1155 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1156
1157 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1158 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1159 if (st->gotcrc != st->realcrc) {
1160 bombout(("Incorrect CRC received on packet"));
1161 ssh_free_packet(st->pktin);
1162 crStop(NULL);
1163 }
1164
1165 st->pktin->body = st->pktin->data + st->pad + 1;
1166 st->pktin->savedpos = 0;
1167
1168 if (ssh->v1_compressing) {
1169 unsigned char *decompblk;
1170 int decomplen;
1171 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1172 st->pktin->body - 1, st->pktin->length + 1,
1173 &decompblk, &decomplen)) {
1174 bombout(("Zlib decompression encountered invalid data"));
1175 ssh_free_packet(st->pktin);
1176 crStop(NULL);
1177 }
1178
1179 if (st->pktin->maxlen < st->pad + decomplen) {
1180 st->pktin->maxlen = st->pad + decomplen;
1181 st->pktin->data = sresize(st->pktin->data,
1182 st->pktin->maxlen + APIEXTRA,
1183 unsigned char);
1184 st->pktin->body = st->pktin->data + st->pad + 1;
1185 }
1186
1187 memcpy(st->pktin->body - 1, decompblk, decomplen);
1188 sfree(decompblk);
1189 st->pktin->length = decomplen - 1;
1190 }
1191
1192 st->pktin->type = st->pktin->body[-1];
1193
1194 /*
1195 * Log incoming packet, possibly omitting sensitive fields.
1196 */
1197 if (ssh->logctx) {
1198 int nblanks = 0;
1199 struct logblank_t blank;
1200 if (ssh->cfg.logomitdata) {
1201 int do_blank = FALSE, blank_prefix = 0;
1202 /* "Session data" packets - omit the data field */
1203 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1204 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1205 do_blank = TRUE; blank_prefix = 0;
1206 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1207 do_blank = TRUE; blank_prefix = 4;
1208 }
1209 if (do_blank) {
1210 blank.offset = blank_prefix;
1211 blank.len = st->pktin->length;
1212 blank.type = PKTLOG_OMIT;
1213 nblanks = 1;
1214 }
1215 }
1216 log_packet(ssh->logctx,
1217 PKT_INCOMING, st->pktin->type,
1218 ssh1_pkt_type(st->pktin->type),
1219 st->pktin->body, st->pktin->length,
1220 nblanks, &blank);
1221 }
1222
1223 crFinish(st->pktin);
1224 }
1225
1226 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1227 {
1228 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1229
1230 crBegin(ssh->ssh2_rdpkt_crstate);
1231
1232 st->pktin = ssh_new_packet();
1233
1234 st->pktin->type = 0;
1235 st->pktin->length = 0;
1236 if (ssh->sccipher)
1237 st->cipherblk = ssh->sccipher->blksize;
1238 else
1239 st->cipherblk = 8;
1240 if (st->cipherblk < 8)
1241 st->cipherblk = 8;
1242
1243 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1244
1245 /*
1246 * Acquire and decrypt the first block of the packet. This will
1247 * contain the length and padding details.
1248 */
1249 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1250 while ((*datalen) == 0)
1251 crReturn(NULL);
1252 st->pktin->data[st->i] = *(*data)++;
1253 (*datalen)--;
1254 }
1255
1256 if (ssh->sccipher)
1257 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1258 st->pktin->data, st->cipherblk);
1259
1260 /*
1261 * Now get the length and padding figures.
1262 */
1263 st->len = GET_32BIT(st->pktin->data);
1264 st->pad = st->pktin->data[4];
1265
1266 /*
1267 * _Completely_ silly lengths should be stomped on before they
1268 * do us any more damage.
1269 */
1270 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1271 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
1272 bombout(("Incoming packet was garbled on decryption"));
1273 ssh_free_packet(st->pktin);
1274 crStop(NULL);
1275 }
1276
1277 /*
1278 * This enables us to deduce the payload length.
1279 */
1280 st->payload = st->len - st->pad - 1;
1281
1282 st->pktin->length = st->payload + 5;
1283
1284 /*
1285 * So now we can work out the total packet length.
1286 */
1287 st->packetlen = st->len + 4;
1288 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1289
1290 /*
1291 * Allocate memory for the rest of the packet.
1292 */
1293 st->pktin->maxlen = st->packetlen + st->maclen;
1294 st->pktin->data = sresize(st->pktin->data,
1295 st->pktin->maxlen + APIEXTRA,
1296 unsigned char);
1297
1298 /*
1299 * Read and decrypt the remainder of the packet.
1300 */
1301 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1302 st->i++) {
1303 while ((*datalen) == 0)
1304 crReturn(NULL);
1305 st->pktin->data[st->i] = *(*data)++;
1306 (*datalen)--;
1307 }
1308 /* Decrypt everything _except_ the MAC. */
1309 if (ssh->sccipher)
1310 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1311 st->pktin->data + st->cipherblk,
1312 st->packetlen - st->cipherblk);
1313
1314 st->pktin->encrypted_len = st->packetlen;
1315
1316 /*
1317 * Check the MAC.
1318 */
1319 if (ssh->scmac
1320 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1321 st->incoming_sequence)) {
1322 bombout(("Incorrect MAC received on packet"));
1323 ssh_free_packet(st->pktin);
1324 crStop(NULL);
1325 }
1326
1327 st->pktin->sequence = st->incoming_sequence++;
1328
1329 /*
1330 * Decompress packet payload.
1331 */
1332 {
1333 unsigned char *newpayload;
1334 int newlen;
1335 if (ssh->sccomp &&
1336 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1337 st->pktin->data + 5, st->pktin->length - 5,
1338 &newpayload, &newlen)) {
1339 if (st->pktin->maxlen < newlen + 5) {
1340 st->pktin->maxlen = newlen + 5;
1341 st->pktin->data = sresize(st->pktin->data,
1342 st->pktin->maxlen + APIEXTRA,
1343 unsigned char);
1344 }
1345 st->pktin->length = 5 + newlen;
1346 memcpy(st->pktin->data + 5, newpayload, newlen);
1347 sfree(newpayload);
1348 }
1349 }
1350
1351 st->pktin->savedpos = 6;
1352 st->pktin->body = st->pktin->data;
1353 st->pktin->type = st->pktin->data[5];
1354
1355 /*
1356 * Log incoming packet, possibly omitting sensitive fields.
1357 */
1358 if (ssh->logctx) {
1359 int nblanks = 0;
1360 struct logblank_t blank;
1361 if (ssh->cfg.logomitdata) {
1362 int do_blank = FALSE, blank_prefix = 0;
1363 /* "Session data" packets - omit the data field */
1364 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1365 do_blank = TRUE; blank_prefix = 4;
1366 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1367 do_blank = TRUE; blank_prefix = 8;
1368 }
1369 if (do_blank) {
1370 blank.offset = blank_prefix;
1371 blank.len = (st->pktin->length-6) - blank_prefix;
1372 blank.type = PKTLOG_OMIT;
1373 nblanks = 1;
1374 }
1375 }
1376 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1377 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1378 st->pktin->data+6, st->pktin->length-6,
1379 nblanks, &blank);
1380 }
1381
1382 crFinish(st->pktin);
1383 }
1384
1385 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1386 {
1387 int pad, biglen, i, pktoffs;
1388 unsigned long crc;
1389 #ifdef __SC__
1390 /*
1391 * XXX various versions of SC (including 8.8.4) screw up the
1392 * register allocation in this function and use the same register
1393 * (D6) for len and as a temporary, with predictable results. The
1394 * following sledgehammer prevents this.
1395 */
1396 volatile
1397 #endif
1398 int len;
1399
1400 if (ssh->logctx)
1401 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1402 ssh1_pkt_type(pkt->data[12]),
1403 pkt->body, pkt->length - (pkt->body - pkt->data),
1404 pkt->nblanks, pkt->blanks);
1405 sfree(pkt->blanks); pkt->blanks = NULL;
1406 pkt->nblanks = 0;
1407
1408 if (ssh->v1_compressing) {
1409 unsigned char *compblk;
1410 int complen;
1411 zlib_compress_block(ssh->cs_comp_ctx,
1412 pkt->data + 12, pkt->length - 12,
1413 &compblk, &complen);
1414 memcpy(pkt->data + 12, compblk, complen);
1415 sfree(compblk);
1416 pkt->length = complen + 12;
1417 }
1418
1419 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1420 pkt->length += 4;
1421 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1422 pad = 8 - (len % 8);
1423 pktoffs = 8 - pad;
1424 biglen = len + pad; /* len(padding+type+data+CRC) */
1425
1426 for (i = pktoffs; i < 4+8; i++)
1427 pkt->data[i] = random_byte();
1428 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1429 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1430 PUT_32BIT(pkt->data + pktoffs, len);
1431
1432 if (ssh->cipher)
1433 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1434 pkt->data + pktoffs + 4, biglen);
1435
1436 if (offset_p) *offset_p = pktoffs;
1437 return biglen + 4; /* len(length+padding+type+data+CRC) */
1438 }
1439
1440 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1441 {
1442 int len, backlog, offset;
1443 len = s_wrpkt_prepare(ssh, pkt, &offset);
1444 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1445 if (backlog > SSH_MAX_BACKLOG)
1446 ssh_throttle_all(ssh, 1, backlog);
1447 ssh_free_packet(pkt);
1448 }
1449
1450 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1451 {
1452 int len, offset;
1453 len = s_wrpkt_prepare(ssh, pkt, &offset);
1454 if (ssh->deferred_len + len > ssh->deferred_size) {
1455 ssh->deferred_size = ssh->deferred_len + len + 128;
1456 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1457 ssh->deferred_size,
1458 unsigned char);
1459 }
1460 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1461 pkt->data + offset, len);
1462 ssh->deferred_len += len;
1463 ssh_free_packet(pkt);
1464 }
1465
1466 /*
1467 * Construct a SSH-1 packet with the specified contents.
1468 * (This all-at-once interface used to be the only one, but now SSH-1
1469 * packets can also be constructed incrementally.)
1470 */
1471 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1472 {
1473 int argtype;
1474 Bignum bn;
1475 struct Packet *pkt;
1476
1477 pkt = ssh1_pkt_init(pkttype);
1478
1479 while ((argtype = va_arg(ap, int)) != PKT_END) {
1480 unsigned char *argp, argchar;
1481 unsigned long argint;
1482 int arglen;
1483 switch (argtype) {
1484 /* Actual fields in the packet */
1485 case PKT_INT:
1486 argint = va_arg(ap, int);
1487 ssh_pkt_adduint32(pkt, argint);
1488 break;
1489 case PKT_CHAR:
1490 argchar = (unsigned char) va_arg(ap, int);
1491 ssh_pkt_addbyte(pkt, argchar);
1492 break;
1493 case PKT_DATA:
1494 argp = va_arg(ap, unsigned char *);
1495 arglen = va_arg(ap, int);
1496 ssh_pkt_adddata(pkt, argp, arglen);
1497 break;
1498 case PKT_STR:
1499 argp = va_arg(ap, unsigned char *);
1500 ssh_pkt_addstring(pkt, argp);
1501 break;
1502 case PKT_BIGNUM:
1503 bn = va_arg(ap, Bignum);
1504 ssh1_pkt_addmp(pkt, bn);
1505 break;
1506 /* Tokens for modifications to packet logging */
1507 case PKTT_PASSWORD:
1508 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1509 break;
1510 case PKTT_DATA:
1511 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1512 break;
1513 case PKTT_OTHER:
1514 end_log_omission(ssh, pkt);
1515 break;
1516 }
1517 }
1518
1519 return pkt;
1520 }
1521
1522 static void send_packet(Ssh ssh, int pkttype, ...)
1523 {
1524 struct Packet *pkt;
1525 va_list ap;
1526 va_start(ap, pkttype);
1527 pkt = construct_packet(ssh, pkttype, ap);
1528 va_end(ap);
1529 s_wrpkt(ssh, pkt);
1530 }
1531
1532 static void defer_packet(Ssh ssh, int pkttype, ...)
1533 {
1534 struct Packet *pkt;
1535 va_list ap;
1536 va_start(ap, pkttype);
1537 pkt = construct_packet(ssh, pkttype, ap);
1538 va_end(ap);
1539 s_wrpkt_defer(ssh, pkt);
1540 }
1541
1542 static int ssh_versioncmp(char *a, char *b)
1543 {
1544 char *ae, *be;
1545 unsigned long av, bv;
1546
1547 av = strtoul(a, &ae, 10);
1548 bv = strtoul(b, &be, 10);
1549 if (av != bv)
1550 return (av < bv ? -1 : +1);
1551 if (*ae == '.')
1552 ae++;
1553 if (*be == '.')
1554 be++;
1555 av = strtoul(ae, &ae, 10);
1556 bv = strtoul(be, &be, 10);
1557 if (av != bv)
1558 return (av < bv ? -1 : +1);
1559 return 0;
1560 }
1561
1562 /*
1563 * Utility routines for putting an SSH-protocol `string' and
1564 * `uint32' into a SHA state.
1565 */
1566 static void sha_string(SHA_State * s, void *str, int len)
1567 {
1568 unsigned char lenblk[4];
1569 PUT_32BIT(lenblk, len);
1570 SHA_Bytes(s, lenblk, 4);
1571 SHA_Bytes(s, str, len);
1572 }
1573
1574 static void sha_uint32(SHA_State * s, unsigned i)
1575 {
1576 unsigned char intblk[4];
1577 PUT_32BIT(intblk, i);
1578 SHA_Bytes(s, intblk, 4);
1579 }
1580
1581 /*
1582 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1583 */
1584 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1585 {
1586 if (pkt->maxlen < length) {
1587 unsigned char *body = pkt->body;
1588 int offset = body ? pkt->data - body : 0;
1589 pkt->maxlen = length + 256;
1590 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1591 if (body) pkt->body = pkt->data + offset;
1592 }
1593 }
1594 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1595 {
1596 if (pkt->logmode != PKTLOG_EMIT) {
1597 pkt->nblanks++;
1598 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1599 assert(pkt->body);
1600 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1601 (pkt->body - pkt->data);
1602 pkt->blanks[pkt->nblanks-1].len = len;
1603 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1604 }
1605 pkt->length += len;
1606 ssh_pkt_ensure(pkt, pkt->length);
1607 memcpy(pkt->data + pkt->length - len, data, len);
1608 }
1609 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1610 {
1611 ssh_pkt_adddata(pkt, &byte, 1);
1612 }
1613 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1614 {
1615 ssh_pkt_adddata(pkt, &value, 1);
1616 }
1617 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1618 {
1619 unsigned char x[4];
1620 PUT_32BIT(x, value);
1621 ssh_pkt_adddata(pkt, x, 4);
1622 }
1623 static void ssh_pkt_addstring_start(struct Packet *pkt)
1624 {
1625 ssh_pkt_adduint32(pkt, 0);
1626 pkt->savedpos = pkt->length;
1627 }
1628 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1629 {
1630 ssh_pkt_adddata(pkt, data, strlen(data));
1631 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1632 }
1633 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1634 {
1635 ssh_pkt_adddata(pkt, data, len);
1636 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1637 }
1638 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1639 {
1640 ssh_pkt_addstring_start(pkt);
1641 ssh_pkt_addstring_str(pkt, data);
1642 }
1643 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1644 {
1645 int len = ssh1_bignum_length(b);
1646 unsigned char *data = snewn(len, char);
1647 (void) ssh1_write_bignum(data, b);
1648 ssh_pkt_adddata(pkt, data, len);
1649 sfree(data);
1650 }
1651 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1652 {
1653 unsigned char *p;
1654 int i, n = (bignum_bitcount(b) + 7) / 8;
1655 p = snewn(n + 1, unsigned char);
1656 p[0] = 0;
1657 for (i = 1; i <= n; i++)
1658 p[i] = bignum_byte(b, n - i);
1659 i = 0;
1660 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1661 i++;
1662 memmove(p, p + i, n + 1 - i);
1663 *len = n + 1 - i;
1664 return p;
1665 }
1666 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1667 {
1668 unsigned char *p;
1669 int len;
1670 p = ssh2_mpint_fmt(b, &len);
1671 ssh_pkt_addstring_start(pkt);
1672 ssh_pkt_addstring_data(pkt, (char *)p, len);
1673 sfree(p);
1674 }
1675
1676 static struct Packet *ssh1_pkt_init(int pkt_type)
1677 {
1678 struct Packet *pkt = ssh_new_packet();
1679 pkt->length = 4 + 8; /* space for length + max padding */
1680 ssh_pkt_addbyte(pkt, pkt_type);
1681 pkt->body = pkt->data + pkt->length;
1682 return pkt;
1683 }
1684
1685 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1686 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1687 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1688 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1689 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1690 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1691 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1692 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1693 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1694
1695 static struct Packet *ssh2_pkt_init(int pkt_type)
1696 {
1697 struct Packet *pkt = ssh_new_packet();
1698 pkt->length = 5;
1699 pkt->forcepad = 0;
1700 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1701 pkt->body = pkt->data + pkt->length;
1702 return pkt;
1703 }
1704
1705 /*
1706 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1707 * put the MAC on it. Final packet, ready to be sent, is stored in
1708 * pkt->data. Total length is returned.
1709 */
1710 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1711 {
1712 int cipherblk, maclen, padding, i;
1713
1714 if (ssh->logctx)
1715 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1716 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1717 pkt->body, pkt->length - (pkt->body - pkt->data),
1718 pkt->nblanks, pkt->blanks);
1719 sfree(pkt->blanks); pkt->blanks = NULL;
1720 pkt->nblanks = 0;
1721
1722 /*
1723 * Compress packet payload.
1724 */
1725 {
1726 unsigned char *newpayload;
1727 int newlen;
1728 if (ssh->cscomp &&
1729 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1730 pkt->length - 5,
1731 &newpayload, &newlen)) {
1732 pkt->length = 5;
1733 ssh2_pkt_adddata(pkt, newpayload, newlen);
1734 sfree(newpayload);
1735 }
1736 }
1737
1738 /*
1739 * Add padding. At least four bytes, and must also bring total
1740 * length (minus MAC) up to a multiple of the block size.
1741 * If pkt->forcepad is set, make sure the packet is at least that size
1742 * after padding.
1743 */
1744 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1745 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1746 padding = 4;
1747 if (pkt->length + padding < pkt->forcepad)
1748 padding = pkt->forcepad - pkt->length;
1749 padding +=
1750 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1751 assert(padding <= 255);
1752 maclen = ssh->csmac ? ssh->csmac->len : 0;
1753 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1754 pkt->data[4] = padding;
1755 for (i = 0; i < padding; i++)
1756 pkt->data[pkt->length + i] = random_byte();
1757 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1758 if (ssh->csmac)
1759 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1760 pkt->length + padding,
1761 ssh->v2_outgoing_sequence);
1762 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1763
1764 if (ssh->cscipher)
1765 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1766 pkt->data, pkt->length + padding);
1767
1768 pkt->encrypted_len = pkt->length + padding;
1769
1770 /* Ready-to-send packet starts at pkt->data. We return length. */
1771 return pkt->length + padding + maclen;
1772 }
1773
1774 /*
1775 * Routines called from the main SSH code to send packets. There
1776 * are quite a few of these, because we have two separate
1777 * mechanisms for delaying the sending of packets:
1778 *
1779 * - In order to send an IGNORE message and a password message in
1780 * a single fixed-length blob, we require the ability to
1781 * concatenate the encrypted forms of those two packets _into_ a
1782 * single blob and then pass it to our <network.h> transport
1783 * layer in one go. Hence, there's a deferment mechanism which
1784 * works after packet encryption.
1785 *
1786 * - In order to avoid sending any connection-layer messages
1787 * during repeat key exchange, we have to queue up any such
1788 * outgoing messages _before_ they are encrypted (and in
1789 * particular before they're allocated sequence numbers), and
1790 * then send them once we've finished.
1791 *
1792 * I call these mechanisms `defer' and `queue' respectively, so as
1793 * to distinguish them reasonably easily.
1794 *
1795 * The functions send_noqueue() and defer_noqueue() free the packet
1796 * structure they are passed. Every outgoing packet goes through
1797 * precisely one of these functions in its life; packets passed to
1798 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1799 * these or get queued, and then when the queue is later emptied
1800 * the packets are all passed to defer_noqueue().
1801 *
1802 * When using a CBC-mode cipher, it's necessary to ensure that an
1803 * attacker can't provide data to be encrypted using an IV that they
1804 * know. We ensure this by prefixing each packet that might contain
1805 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1806 * mechanism, so in this case send_noqueue() ends up redirecting to
1807 * defer_noqueue(). If you don't like this inefficiency, don't use
1808 * CBC.
1809 */
1810
1811 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1812 static void ssh_pkt_defersend(Ssh);
1813
1814 /*
1815 * Send an SSH-2 packet immediately, without queuing or deferring.
1816 */
1817 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1818 {
1819 int len;
1820 int backlog;
1821 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1822 /* We need to send two packets, so use the deferral mechanism. */
1823 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1824 ssh_pkt_defersend(ssh);
1825 return;
1826 }
1827 len = ssh2_pkt_construct(ssh, pkt);
1828 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1829 if (backlog > SSH_MAX_BACKLOG)
1830 ssh_throttle_all(ssh, 1, backlog);
1831
1832 ssh->outgoing_data_size += pkt->encrypted_len;
1833 if (!ssh->kex_in_progress &&
1834 ssh->max_data_size != 0 &&
1835 ssh->outgoing_data_size > ssh->max_data_size)
1836 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1837
1838 ssh_free_packet(pkt);
1839 }
1840
1841 /*
1842 * Defer an SSH-2 packet.
1843 */
1844 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1845 {
1846 int len;
1847 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1848 ssh->deferred_len == 0 && !noignore) {
1849 /*
1850 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1851 * get encrypted with a known IV.
1852 */
1853 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1854 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1855 }
1856 len = ssh2_pkt_construct(ssh, pkt);
1857 if (ssh->deferred_len + len > ssh->deferred_size) {
1858 ssh->deferred_size = ssh->deferred_len + len + 128;
1859 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1860 ssh->deferred_size,
1861 unsigned char);
1862 }
1863 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1864 ssh->deferred_len += len;
1865 ssh->deferred_data_size += pkt->encrypted_len;
1866 ssh_free_packet(pkt);
1867 }
1868
1869 /*
1870 * Queue an SSH-2 packet.
1871 */
1872 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1873 {
1874 assert(ssh->queueing);
1875
1876 if (ssh->queuelen >= ssh->queuesize) {
1877 ssh->queuesize = ssh->queuelen + 32;
1878 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1879 }
1880
1881 ssh->queue[ssh->queuelen++] = pkt;
1882 }
1883
1884 /*
1885 * Either queue or send a packet, depending on whether queueing is
1886 * set.
1887 */
1888 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1889 {
1890 if (ssh->queueing)
1891 ssh2_pkt_queue(ssh, pkt);
1892 else
1893 ssh2_pkt_send_noqueue(ssh, pkt);
1894 }
1895
1896 #if 0 /* disused */
1897 /*
1898 * Either queue or defer a packet, depending on whether queueing is
1899 * set.
1900 */
1901 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1902 {
1903 if (ssh->queueing)
1904 ssh2_pkt_queue(ssh, pkt);
1905 else
1906 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1907 }
1908 #endif
1909
1910 /*
1911 * Send the whole deferred data block constructed by
1912 * ssh2_pkt_defer() or SSH-1's defer_packet().
1913 *
1914 * The expected use of the defer mechanism is that you call
1915 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1916 * not currently queueing, this simply sets up deferred_send_data
1917 * and then sends it. If we _are_ currently queueing, the calls to
1918 * ssh2_pkt_defer() put the deferred packets on to the queue
1919 * instead, and therefore ssh_pkt_defersend() has no deferred data
1920 * to send. Hence, there's no need to make it conditional on
1921 * ssh->queueing.
1922 */
1923 static void ssh_pkt_defersend(Ssh ssh)
1924 {
1925 int backlog;
1926 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1927 ssh->deferred_len);
1928 ssh->deferred_len = ssh->deferred_size = 0;
1929 sfree(ssh->deferred_send_data);
1930 ssh->deferred_send_data = NULL;
1931 if (backlog > SSH_MAX_BACKLOG)
1932 ssh_throttle_all(ssh, 1, backlog);
1933
1934 ssh->outgoing_data_size += ssh->deferred_data_size;
1935 if (!ssh->kex_in_progress &&
1936 ssh->max_data_size != 0 &&
1937 ssh->outgoing_data_size > ssh->max_data_size)
1938 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1939 ssh->deferred_data_size = 0;
1940 }
1941
1942 /*
1943 * Send all queued SSH-2 packets. We send them by means of
1944 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1945 * packets that needed to be lumped together.
1946 */
1947 static void ssh2_pkt_queuesend(Ssh ssh)
1948 {
1949 int i;
1950
1951 assert(!ssh->queueing);
1952
1953 for (i = 0; i < ssh->queuelen; i++)
1954 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
1955 ssh->queuelen = 0;
1956
1957 ssh_pkt_defersend(ssh);
1958 }
1959
1960 #if 0
1961 void bndebug(char *string, Bignum b)
1962 {
1963 unsigned char *p;
1964 int i, len;
1965 p = ssh2_mpint_fmt(b, &len);
1966 debug(("%s", string));
1967 for (i = 0; i < len; i++)
1968 debug((" %02x", p[i]));
1969 debug(("\n"));
1970 sfree(p);
1971 }
1972 #endif
1973
1974 static void sha_mpint(SHA_State * s, Bignum b)
1975 {
1976 unsigned char *p;
1977 int len;
1978 p = ssh2_mpint_fmt(b, &len);
1979 sha_string(s, p, len);
1980 sfree(p);
1981 }
1982
1983 /*
1984 * Packet decode functions for both SSH-1 and SSH-2.
1985 */
1986 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1987 {
1988 unsigned long value;
1989 if (pkt->length - pkt->savedpos < 4)
1990 return 0; /* arrgh, no way to decline (FIXME?) */
1991 value = GET_32BIT(pkt->body + pkt->savedpos);
1992 pkt->savedpos += 4;
1993 return value;
1994 }
1995 static int ssh2_pkt_getbool(struct Packet *pkt)
1996 {
1997 unsigned long value;
1998 if (pkt->length - pkt->savedpos < 1)
1999 return 0; /* arrgh, no way to decline (FIXME?) */
2000 value = pkt->body[pkt->savedpos] != 0;
2001 pkt->savedpos++;
2002 return value;
2003 }
2004 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2005 {
2006 int len;
2007 *p = NULL;
2008 *length = 0;
2009 if (pkt->length - pkt->savedpos < 4)
2010 return;
2011 len = GET_32BIT(pkt->body + pkt->savedpos);
2012 if (len < 0)
2013 return;
2014 *length = len;
2015 pkt->savedpos += 4;
2016 if (pkt->length - pkt->savedpos < *length)
2017 return;
2018 *p = (char *)(pkt->body + pkt->savedpos);
2019 pkt->savedpos += *length;
2020 }
2021 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2022 {
2023 if (pkt->length - pkt->savedpos < length)
2024 return NULL;
2025 pkt->savedpos += length;
2026 return pkt->body + (pkt->savedpos - length);
2027 }
2028 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2029 unsigned char **keystr)
2030 {
2031 int j;
2032
2033 j = makekey(pkt->body + pkt->savedpos,
2034 pkt->length - pkt->savedpos,
2035 key, keystr, 0);
2036
2037 if (j < 0)
2038 return FALSE;
2039
2040 pkt->savedpos += j;
2041 assert(pkt->savedpos < pkt->length);
2042
2043 return TRUE;
2044 }
2045 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2046 {
2047 int j;
2048 Bignum b;
2049
2050 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2051 pkt->length - pkt->savedpos, &b);
2052
2053 if (j < 0)
2054 return NULL;
2055
2056 pkt->savedpos += j;
2057 return b;
2058 }
2059 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2060 {
2061 char *p;
2062 int length;
2063 Bignum b;
2064
2065 ssh_pkt_getstring(pkt, &p, &length);
2066 if (!p)
2067 return NULL;
2068 if (p[0] & 0x80)
2069 return NULL;
2070 b = bignum_from_bytes((unsigned char *)p, length);
2071 return b;
2072 }
2073
2074 /*
2075 * Helper function to add an SSH-2 signature blob to a packet.
2076 * Expects to be shown the public key blob as well as the signature
2077 * blob. Normally works just like ssh2_pkt_addstring, but will
2078 * fiddle with the signature packet if necessary for
2079 * BUG_SSH2_RSA_PADDING.
2080 */
2081 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2082 void *pkblob_v, int pkblob_len,
2083 void *sigblob_v, int sigblob_len)
2084 {
2085 unsigned char *pkblob = (unsigned char *)pkblob_v;
2086 unsigned char *sigblob = (unsigned char *)sigblob_v;
2087
2088 /* dmemdump(pkblob, pkblob_len); */
2089 /* dmemdump(sigblob, sigblob_len); */
2090
2091 /*
2092 * See if this is in fact an ssh-rsa signature and a buggy
2093 * server; otherwise we can just do this the easy way.
2094 */
2095 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2096 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2097 int pos, len, siglen;
2098
2099 /*
2100 * Find the byte length of the modulus.
2101 */
2102
2103 pos = 4+7; /* skip over "ssh-rsa" */
2104 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2105 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2106 pos += 4; /* find modulus itself */
2107 while (len > 0 && pkblob[pos] == 0)
2108 len--, pos++;
2109 /* debug(("modulus length is %d\n", len)); */
2110
2111 /*
2112 * Now find the signature integer.
2113 */
2114 pos = 4+7; /* skip over "ssh-rsa" */
2115 siglen = GET_32BIT(sigblob+pos);
2116 /* debug(("signature length is %d\n", siglen)); */
2117
2118 if (len != siglen) {
2119 unsigned char newlen[4];
2120 ssh2_pkt_addstring_start(pkt);
2121 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2122 /* dmemdump(sigblob, pos); */
2123 pos += 4; /* point to start of actual sig */
2124 PUT_32BIT(newlen, len);
2125 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2126 /* dmemdump(newlen, 4); */
2127 newlen[0] = 0;
2128 while (len-- > siglen) {
2129 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2130 /* dmemdump(newlen, 1); */
2131 }
2132 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2133 /* dmemdump(sigblob+pos, siglen); */
2134 return;
2135 }
2136
2137 /* Otherwise fall through and do it the easy way. */
2138 }
2139
2140 ssh2_pkt_addstring_start(pkt);
2141 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2142 }
2143
2144 /*
2145 * Examine the remote side's version string and compare it against
2146 * a list of known buggy implementations.
2147 */
2148 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2149 {
2150 char *imp; /* pointer to implementation part */
2151 imp = vstring;
2152 imp += strcspn(imp, "-");
2153 if (*imp) imp++;
2154 imp += strcspn(imp, "-");
2155 if (*imp) imp++;
2156
2157 ssh->remote_bugs = 0;
2158
2159 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2160 (ssh->cfg.sshbug_ignore1 == AUTO &&
2161 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2162 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2163 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2164 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2165 /*
2166 * These versions don't support SSH1_MSG_IGNORE, so we have
2167 * to use a different defence against password length
2168 * sniffing.
2169 */
2170 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2171 logevent("We believe remote version has SSH-1 ignore bug");
2172 }
2173
2174 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2175 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2176 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2177 /*
2178 * These versions need a plain password sent; they can't
2179 * handle having a null and a random length of data after
2180 * the password.
2181 */
2182 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2183 logevent("We believe remote version needs a plain SSH-1 password");
2184 }
2185
2186 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2187 (ssh->cfg.sshbug_rsa1 == AUTO &&
2188 (!strcmp(imp, "Cisco-1.25")))) {
2189 /*
2190 * These versions apparently have no clue whatever about
2191 * RSA authentication and will panic and die if they see
2192 * an AUTH_RSA message.
2193 */
2194 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2195 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2196 }
2197
2198 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2199 (ssh->cfg.sshbug_hmac2 == AUTO &&
2200 !wc_match("* VShell", imp) &&
2201 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2202 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2203 wc_match("2.1 *", imp)))) {
2204 /*
2205 * These versions have the HMAC bug.
2206 */
2207 ssh->remote_bugs |= BUG_SSH2_HMAC;
2208 logevent("We believe remote version has SSH-2 HMAC bug");
2209 }
2210
2211 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2212 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2213 !wc_match("* VShell", imp) &&
2214 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2215 /*
2216 * These versions have the key-derivation bug (failing to
2217 * include the literal shared secret in the hashes that
2218 * generate the keys).
2219 */
2220 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2221 logevent("We believe remote version has SSH-2 key-derivation bug");
2222 }
2223
2224 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2225 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2226 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2227 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2228 /*
2229 * These versions have the SSH-2 RSA padding bug.
2230 */
2231 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2232 logevent("We believe remote version has SSH-2 RSA padding bug");
2233 }
2234
2235 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2236 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2237 wc_match("OpenSSH_2.[0-2]*", imp))) {
2238 /*
2239 * These versions have the SSH-2 session-ID bug in
2240 * public-key authentication.
2241 */
2242 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2243 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2244 }
2245
2246 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2247 (ssh->cfg.sshbug_rekey2 == AUTO &&
2248 (wc_match("DigiSSH_2.0", imp) ||
2249 wc_match("OpenSSH_2.[0-4]*", imp) ||
2250 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2251 wc_match("Sun_SSH_1.0", imp) ||
2252 wc_match("Sun_SSH_1.0.1", imp)))) {
2253 /*
2254 * These versions have the SSH-2 rekey bug.
2255 */
2256 ssh->remote_bugs |= BUG_SSH2_REKEY;
2257 logevent("We believe remote version has SSH-2 rekey bug");
2258 }
2259 }
2260
2261 /*
2262 * The `software version' part of an SSH version string is required
2263 * to contain no spaces or minus signs.
2264 */
2265 static void ssh_fix_verstring(char *str)
2266 {
2267 /* Eat "SSH-<protoversion>-". */
2268 assert(*str == 'S'); str++;
2269 assert(*str == 'S'); str++;
2270 assert(*str == 'H'); str++;
2271 assert(*str == '-'); str++;
2272 while (*str && *str != '-') str++;
2273 assert(*str == '-'); str++;
2274
2275 /* Convert minus signs and spaces in the remaining string into
2276 * underscores. */
2277 while (*str) {
2278 if (*str == '-' || *str == ' ')
2279 *str = '_';
2280 str++;
2281 }
2282 }
2283
2284 static int do_ssh_init(Ssh ssh, unsigned char c)
2285 {
2286 struct do_ssh_init_state {
2287 int vslen;
2288 char version[10];
2289 char *vstring;
2290 int vstrsize;
2291 int i;
2292 int proto1, proto2;
2293 };
2294 crState(do_ssh_init_state);
2295
2296 crBegin(ssh->do_ssh_init_crstate);
2297
2298 /* Search for the string "SSH-" in the input. */
2299 s->i = 0;
2300 while (1) {
2301 static const int transS[] = { 1, 2, 2, 1 };
2302 static const int transH[] = { 0, 0, 3, 0 };
2303 static const int transminus[] = { 0, 0, 0, -1 };
2304 if (c == 'S')
2305 s->i = transS[s->i];
2306 else if (c == 'H')
2307 s->i = transH[s->i];
2308 else if (c == '-')
2309 s->i = transminus[s->i];
2310 else
2311 s->i = 0;
2312 if (s->i < 0)
2313 break;
2314 crReturn(1); /* get another character */
2315 }
2316
2317 s->vstrsize = 16;
2318 s->vstring = snewn(s->vstrsize, char);
2319 strcpy(s->vstring, "SSH-");
2320 s->vslen = 4;
2321 s->i = 0;
2322 while (1) {
2323 crReturn(1); /* get another char */
2324 if (s->vslen >= s->vstrsize - 1) {
2325 s->vstrsize += 16;
2326 s->vstring = sresize(s->vstring, s->vstrsize, char);
2327 }
2328 s->vstring[s->vslen++] = c;
2329 if (s->i >= 0) {
2330 if (c == '-') {
2331 s->version[s->i] = '\0';
2332 s->i = -1;
2333 } else if (s->i < sizeof(s->version) - 1)
2334 s->version[s->i++] = c;
2335 } else if (c == '\012')
2336 break;
2337 }
2338
2339 ssh->agentfwd_enabled = FALSE;
2340 ssh->rdpkt2_state.incoming_sequence = 0;
2341
2342 s->vstring[s->vslen] = 0;
2343 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2344 logeventf(ssh, "Server version: %s", s->vstring);
2345 ssh_detect_bugs(ssh, s->vstring);
2346
2347 /*
2348 * Decide which SSH protocol version to support.
2349 */
2350
2351 /* Anything strictly below "2.0" means protocol 1 is supported. */
2352 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2353 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2354 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2355
2356 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2357 bombout(("SSH protocol version 1 required by user but not provided by server"));
2358 crStop(0);
2359 }
2360 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2361 bombout(("SSH protocol version 2 required by user but not provided by server"));
2362 crStop(0);
2363 }
2364
2365 {
2366 char *verstring;
2367
2368 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2369 /*
2370 * Construct a v2 version string.
2371 */
2372 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2373 ssh->version = 2;
2374 } else {
2375 /*
2376 * Construct a v1 version string.
2377 */
2378 verstring = dupprintf("SSH-%s-%s\012",
2379 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2380 s->version : "1.5"),
2381 sshver);
2382 ssh->version = 1;
2383 }
2384
2385 ssh_fix_verstring(verstring);
2386
2387 if (ssh->version == 2) {
2388 /*
2389 * Hash our version string and their version string.
2390 */
2391 SHA_Init(&ssh->exhashbase);
2392 sha_string(&ssh->exhashbase, verstring,
2393 strcspn(verstring, "\015\012"));
2394 sha_string(&ssh->exhashbase, s->vstring,
2395 strcspn(s->vstring, "\015\012"));
2396
2397 /*
2398 * Initialise SSH-2 protocol.
2399 */
2400 ssh->protocol = ssh2_protocol;
2401 ssh2_protocol_setup(ssh);
2402 ssh->s_rdpkt = ssh2_rdpkt;
2403 } else {
2404 /*
2405 * Initialise SSH-1 protocol.
2406 */
2407 ssh->protocol = ssh1_protocol;
2408 ssh1_protocol_setup(ssh);
2409 ssh->s_rdpkt = ssh1_rdpkt;
2410 }
2411 logeventf(ssh, "We claim version: %.*s",
2412 strcspn(verstring, "\015\012"), verstring);
2413 sk_write(ssh->s, verstring, strlen(verstring));
2414 sfree(verstring);
2415 if (ssh->version == 2)
2416 do_ssh2_transport(ssh, NULL, -1, NULL);
2417 }
2418
2419 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2420
2421 update_specials_menu(ssh->frontend);
2422 ssh->state = SSH_STATE_BEFORE_SIZE;
2423 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2424
2425 sfree(s->vstring);
2426
2427 crFinish(0);
2428 }
2429
2430 static void ssh_process_incoming_data(Ssh ssh,
2431 unsigned char **data, int *datalen)
2432 {
2433 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2434 if (pktin) {
2435 ssh->protocol(ssh, NULL, 0, pktin);
2436 ssh_free_packet(pktin);
2437 }
2438 }
2439
2440 static void ssh_queue_incoming_data(Ssh ssh,
2441 unsigned char **data, int *datalen)
2442 {
2443 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2444 *data += *datalen;
2445 *datalen = 0;
2446 }
2447
2448 static void ssh_process_queued_incoming_data(Ssh ssh)
2449 {
2450 void *vdata;
2451 unsigned char *data;
2452 int len, origlen;
2453
2454 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2455 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2456 data = vdata;
2457 origlen = len;
2458
2459 while (!ssh->frozen && len > 0)
2460 ssh_process_incoming_data(ssh, &data, &len);
2461
2462 if (origlen > len)
2463 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2464 }
2465 }
2466
2467 static void ssh_set_frozen(Ssh ssh, int frozen)
2468 {
2469 if (ssh->s)
2470 sk_set_frozen(ssh->s, frozen);
2471 ssh->frozen = frozen;
2472 }
2473
2474 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2475 {
2476 crBegin(ssh->ssh_gotdata_crstate);
2477
2478 /*
2479 * To begin with, feed the characters one by one to the
2480 * protocol initialisation / selection function do_ssh_init().
2481 * When that returns 0, we're done with the initial greeting
2482 * exchange and can move on to packet discipline.
2483 */
2484 while (1) {
2485 int ret; /* need not be kept across crReturn */
2486 if (datalen == 0)
2487 crReturnV; /* more data please */
2488 ret = do_ssh_init(ssh, *data);
2489 data++;
2490 datalen--;
2491 if (ret == 0)
2492 break;
2493 }
2494
2495 /*
2496 * We emerge from that loop when the initial negotiation is
2497 * over and we have selected an s_rdpkt function. Now pass
2498 * everything to s_rdpkt, and then pass the resulting packets
2499 * to the proper protocol handler.
2500 */
2501 if (datalen == 0)
2502 crReturnV;
2503
2504 /*
2505 * Process queued data if there is any.
2506 */
2507 ssh_process_queued_incoming_data(ssh);
2508
2509 while (1) {
2510 while (datalen > 0) {
2511 if (ssh->frozen)
2512 ssh_queue_incoming_data(ssh, &data, &datalen);
2513
2514 ssh_process_incoming_data(ssh, &data, &datalen);
2515
2516 if (ssh->state == SSH_STATE_CLOSED)
2517 return;
2518 }
2519 crReturnV;
2520 }
2521 crFinishV;
2522 }
2523
2524 static int ssh_do_close(Ssh ssh, int notify_exit)
2525 {
2526 int ret = 0;
2527 struct ssh_channel *c;
2528
2529 ssh->state = SSH_STATE_CLOSED;
2530 expire_timer_context(ssh);
2531 if (ssh->s) {
2532 sk_close(ssh->s);
2533 ssh->s = NULL;
2534 if (notify_exit)
2535 notify_remote_exit(ssh->frontend);
2536 else
2537 ret = 1;
2538 }
2539 /*
2540 * Now we must shut down any port- and X-forwarded channels going
2541 * through this connection.
2542 */
2543 if (ssh->channels) {
2544 while (NULL != (c = index234(ssh->channels, 0))) {
2545 switch (c->type) {
2546 case CHAN_X11:
2547 x11_close(c->u.x11.s);
2548 break;
2549 case CHAN_SOCKDATA:
2550 pfd_close(c->u.pfd.s);
2551 break;
2552 }
2553 del234(ssh->channels, c); /* moving next one to index 0 */
2554 if (ssh->version == 2)
2555 bufchain_clear(&c->v.v2.outbuffer);
2556 sfree(c);
2557 }
2558 }
2559 /*
2560 * Go through port-forwardings, and close any associated
2561 * listening sockets.
2562 */
2563 if (ssh->portfwds) {
2564 struct ssh_portfwd *pf;
2565 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2566 /* Dispose of any listening socket. */
2567 if (pf->local)
2568 pfd_terminate(pf->local);
2569 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2570 free_portfwd(pf);
2571 }
2572 }
2573
2574 return ret;
2575 }
2576
2577 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2578 const char *error_msg, int error_code)
2579 {
2580 Ssh ssh = (Ssh) plug;
2581 char addrbuf[256], *msg;
2582
2583 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2584
2585 if (type == 0)
2586 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2587 else
2588 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2589
2590 logevent(msg);
2591 sfree(msg);
2592 }
2593
2594 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2595 int calling_back)
2596 {
2597 Ssh ssh = (Ssh) plug;
2598 int need_notify = ssh_do_close(ssh, FALSE);
2599
2600 if (!error_msg) {
2601 if (!ssh->close_expected)
2602 error_msg = "Server unexpectedly closed network connection";
2603 else
2604 error_msg = "Server closed network connection";
2605 }
2606
2607 if (need_notify)
2608 notify_remote_exit(ssh->frontend);
2609
2610 if (error_msg)
2611 logevent(error_msg);
2612 if (!ssh->close_expected || !ssh->clean_exit)
2613 connection_fatal(ssh->frontend, "%s", error_msg);
2614 return 0;
2615 }
2616
2617 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2618 {
2619 Ssh ssh = (Ssh) plug;
2620 ssh_gotdata(ssh, (unsigned char *)data, len);
2621 if (ssh->state == SSH_STATE_CLOSED) {
2622 ssh_do_close(ssh, TRUE);
2623 return 0;
2624 }
2625 return 1;
2626 }
2627
2628 static void ssh_sent(Plug plug, int bufsize)
2629 {
2630 Ssh ssh = (Ssh) plug;
2631 /*
2632 * If the send backlog on the SSH socket itself clears, we
2633 * should unthrottle the whole world if it was throttled.
2634 */
2635 if (bufsize < SSH_MAX_BACKLOG)
2636 ssh_throttle_all(ssh, 0, bufsize);
2637 }
2638
2639 /*
2640 * Connect to specified host and port.
2641 * Returns an error message, or NULL on success.
2642 * Also places the canonical host name into `realhost'. It must be
2643 * freed by the caller.
2644 */
2645 static const char *connect_to_host(Ssh ssh, char *host, int port,
2646 char **realhost, int nodelay, int keepalive)
2647 {
2648 static const struct plug_function_table fn_table = {
2649 ssh_log,
2650 ssh_closing,
2651 ssh_receive,
2652 ssh_sent,
2653 NULL
2654 };
2655
2656 SockAddr addr;
2657 const char *err;
2658
2659 ssh->savedhost = snewn(1 + strlen(host), char);
2660 strcpy(ssh->savedhost, host);
2661
2662 if (port < 0)
2663 port = 22; /* default ssh port */
2664 ssh->savedport = port;
2665
2666 /*
2667 * Try to find host.
2668 */
2669 logeventf(ssh, "Looking up host \"%s\"%s", host,
2670 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2671 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2672 addr = name_lookup(host, port, realhost, &ssh->cfg,
2673 ssh->cfg.addressfamily);
2674 if ((err = sk_addr_error(addr)) != NULL) {
2675 sk_addr_free(addr);
2676 return err;
2677 }
2678
2679 /*
2680 * Open socket.
2681 */
2682 ssh->fn = &fn_table;
2683 ssh->s = new_connection(addr, *realhost, port,
2684 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2685 if ((err = sk_socket_error(ssh->s)) != NULL) {
2686 ssh->s = NULL;
2687 notify_remote_exit(ssh->frontend);
2688 return err;
2689 }
2690
2691 return NULL;
2692 }
2693
2694 /*
2695 * Throttle or unthrottle the SSH connection.
2696 */
2697 static void ssh1_throttle(Ssh ssh, int adjust)
2698 {
2699 int old_count = ssh->v1_throttle_count;
2700 ssh->v1_throttle_count += adjust;
2701 assert(ssh->v1_throttle_count >= 0);
2702 if (ssh->v1_throttle_count && !old_count) {
2703 ssh_set_frozen(ssh, 1);
2704 } else if (!ssh->v1_throttle_count && old_count) {
2705 ssh_set_frozen(ssh, 0);
2706 }
2707 }
2708
2709 /*
2710 * Throttle or unthrottle _all_ local data streams (for when sends
2711 * on the SSH connection itself back up).
2712 */
2713 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2714 {
2715 int i;
2716 struct ssh_channel *c;
2717
2718 if (enable == ssh->throttled_all)
2719 return;
2720 ssh->throttled_all = enable;
2721 ssh->overall_bufsize = bufsize;
2722 if (!ssh->channels)
2723 return;
2724 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2725 switch (c->type) {
2726 case CHAN_MAINSESSION:
2727 /*
2728 * This is treated separately, outside the switch.
2729 */
2730 break;
2731 case CHAN_X11:
2732 x11_override_throttle(c->u.x11.s, enable);
2733 break;
2734 case CHAN_AGENT:
2735 /* Agent channels require no buffer management. */
2736 break;
2737 case CHAN_SOCKDATA:
2738 pfd_override_throttle(c->u.pfd.s, enable);
2739 break;
2740 }
2741 }
2742 }
2743
2744 /*
2745 * Username and password input, abstracted off into routines
2746 * reusable in several places - even between SSH-1 and SSH-2.
2747 */
2748
2749 /* Set up a username or password input loop on a given buffer. */
2750 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2751 {
2752 ssh->userpass_input_buffer = buffer;
2753 ssh->userpass_input_buflen = buflen;
2754 ssh->userpass_input_bufpos = 0;
2755 ssh->userpass_input_echo = echo;
2756 }
2757
2758 /*
2759 * Process some terminal data in the course of username/password
2760 * input. Returns >0 for success (line of input returned in
2761 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2762 * for inconclusive (keep waiting for more input please).
2763 */
2764 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2765 {
2766 char c;
2767
2768 while (inlen--) {
2769 switch (c = *in++) {
2770 case 10:
2771 case 13:
2772 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2773 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2774 return +1;
2775 break;
2776 case 8:
2777 case 127:
2778 if (ssh->userpass_input_bufpos > 0) {
2779 if (ssh->userpass_input_echo)
2780 c_write_str(ssh, "\b \b");
2781 ssh->userpass_input_bufpos--;
2782 }
2783 break;
2784 case 21:
2785 case 27:
2786 while (ssh->userpass_input_bufpos > 0) {
2787 if (ssh->userpass_input_echo)
2788 c_write_str(ssh, "\b \b");
2789 ssh->userpass_input_bufpos--;
2790 }
2791 break;
2792 case 3:
2793 case 4:
2794 return -1;
2795 break;
2796 default:
2797 /*
2798 * This simplistic check for printability is disabled
2799 * when we're doing password input, because some people
2800 * have control characters in their passwords.o
2801 */
2802 if ((!ssh->userpass_input_echo ||
2803 (c >= ' ' && c <= '~') ||
2804 ((unsigned char) c >= 160))
2805 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2806 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2807 if (ssh->userpass_input_echo)
2808 c_write(ssh, &c, 1);
2809 }
2810 break;
2811 }
2812 }
2813 return 0;
2814 }
2815
2816 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2817 {
2818 Ssh ssh = (Ssh) sshv;
2819
2820 ssh->agent_response = reply;
2821 ssh->agent_response_len = replylen;
2822
2823 if (ssh->version == 1)
2824 do_ssh1_login(ssh, NULL, -1, NULL);
2825 else
2826 do_ssh2_authconn(ssh, NULL, -1, NULL);
2827 }
2828
2829 static void ssh_dialog_callback(void *sshv, int ret)
2830 {
2831 Ssh ssh = (Ssh) sshv;
2832
2833 ssh->user_response = ret;
2834
2835 if (ssh->version == 1)
2836 do_ssh1_login(ssh, NULL, -1, NULL);
2837 else
2838 do_ssh2_transport(ssh, NULL, -1, NULL);
2839
2840 /*
2841 * This may have unfrozen the SSH connection, so do a
2842 * queued-data run.
2843 */
2844 ssh_process_queued_incoming_data(ssh);
2845 }
2846
2847 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2848 {
2849 struct ssh_channel *c = (struct ssh_channel *)cv;
2850 Ssh ssh = c->ssh;
2851 void *sentreply = reply;
2852
2853 if (!sentreply) {
2854 /* Fake SSH_AGENT_FAILURE. */
2855 sentreply = "\0\0\0\1\5";
2856 replylen = 5;
2857 }
2858 if (ssh->version == 2) {
2859 ssh2_add_channel_data(c, sentreply, replylen);
2860 ssh2_try_send(c);
2861 } else {
2862 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2863 PKT_INT, c->remoteid,
2864 PKTT_DATA,
2865 PKT_INT, replylen,
2866 PKT_DATA, sentreply, replylen,
2867 PKTT_OTHER,
2868 PKT_END);
2869 }
2870 if (reply)
2871 sfree(reply);
2872 }
2873
2874 /*
2875 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2876 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2877 * => log `wire_reason'.
2878 */
2879 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2880 int code, int clean_exit)
2881 {
2882 char *error;
2883 if (!client_reason)
2884 client_reason = wire_reason;
2885 if (client_reason)
2886 error = dupprintf("Disconnected: %s", client_reason);
2887 else
2888 error = dupstr("Disconnected");
2889 if (wire_reason) {
2890 if (ssh->version == 1) {
2891 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2892 PKT_END);
2893 } else if (ssh->version == 2) {
2894 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2895 ssh2_pkt_adduint32(pktout, code);
2896 ssh2_pkt_addstring(pktout, wire_reason);
2897 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2898 ssh2_pkt_send_noqueue(ssh, pktout);
2899 }
2900 }
2901 ssh->close_expected = TRUE;
2902 ssh->clean_exit = clean_exit;
2903 ssh_closing((Plug)ssh, error, 0, 0);
2904 sfree(error);
2905 }
2906
2907 /*
2908 * Handle the key exchange and user authentication phases.
2909 */
2910 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2911 struct Packet *pktin)
2912 {
2913 int i, j, ret;
2914 unsigned char cookie[8], *ptr;
2915 struct RSAKey servkey, hostkey;
2916 struct MD5Context md5c;
2917 struct do_ssh1_login_state {
2918 int len;
2919 unsigned char *rsabuf, *keystr1, *keystr2;
2920 unsigned long supported_ciphers_mask, supported_auths_mask;
2921 int tried_publickey, tried_agent;
2922 int tis_auth_refused, ccard_auth_refused;
2923 unsigned char session_id[16];
2924 int cipher_type;
2925 char username[100];
2926 void *publickey_blob;
2927 int publickey_bloblen;
2928 char password[100];
2929 char prompt[200];
2930 int pos;
2931 char c;
2932 int pwpkt_type;
2933 unsigned char request[5], *response, *p;
2934 int responselen;
2935 int keyi, nkeys;
2936 int authed;
2937 struct RSAKey key;
2938 Bignum challenge;
2939 char *commentp;
2940 int commentlen;
2941 int dlgret;
2942 };
2943 crState(do_ssh1_login_state);
2944
2945 crBegin(ssh->do_ssh1_login_crstate);
2946
2947 if (!pktin)
2948 crWaitUntil(pktin);
2949
2950 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2951 bombout(("Public key packet not received"));
2952 crStop(0);
2953 }
2954
2955 logevent("Received public keys");
2956
2957 ptr = ssh_pkt_getdata(pktin, 8);
2958 if (!ptr) {
2959 bombout(("SSH-1 public key packet stopped before random cookie"));
2960 crStop(0);
2961 }
2962 memcpy(cookie, ptr, 8);
2963
2964 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2965 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2966 bombout(("Failed to read SSH-1 public keys from public key packet"));
2967 crStop(0);
2968 }
2969
2970 /*
2971 * Log the host key fingerprint.
2972 */
2973 {
2974 char logmsg[80];
2975 logevent("Host key fingerprint is:");
2976 strcpy(logmsg, " ");
2977 hostkey.comment = NULL;
2978 rsa_fingerprint(logmsg + strlen(logmsg),
2979 sizeof(logmsg) - strlen(logmsg), &hostkey);
2980 logevent(logmsg);
2981 }
2982
2983 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2984 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2985 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2986
2987 ssh->v1_local_protoflags =
2988 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2989 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2990
2991 MD5Init(&md5c);
2992 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2993 MD5Update(&md5c, s->keystr1, servkey.bytes);
2994 MD5Update(&md5c, cookie, 8);
2995 MD5Final(s->session_id, &md5c);
2996
2997 for (i = 0; i < 32; i++)
2998 ssh->session_key[i] = random_byte();
2999
3000 /*
3001 * Verify that the `bits' and `bytes' parameters match.
3002 */
3003 if (hostkey.bits > hostkey.bytes * 8 ||
3004 servkey.bits > servkey.bytes * 8) {
3005 bombout(("SSH-1 public keys were badly formatted"));
3006 crStop(0);
3007 }
3008
3009 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3010
3011 s->rsabuf = snewn(s->len, unsigned char);
3012
3013 /*
3014 * Verify the host key.
3015 */
3016 {
3017 /*
3018 * First format the key into a string.
3019 */
3020 int len = rsastr_len(&hostkey);
3021 char fingerprint[100];
3022 char *keystr = snewn(len, char);
3023 rsastr_fmt(keystr, &hostkey);
3024 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3025
3026 ssh_set_frozen(ssh, 1);
3027 s->dlgret = verify_ssh_host_key(ssh->frontend,
3028 ssh->savedhost, ssh->savedport,
3029 "rsa", keystr, fingerprint,
3030 ssh_dialog_callback, ssh);
3031 sfree(keystr);
3032 if (s->dlgret < 0) {
3033 do {
3034 crReturn(0);
3035 if (pktin) {
3036 bombout(("Unexpected data from server while waiting"
3037 " for user host key response"));
3038 crStop(0);
3039 }
3040 } while (pktin || inlen > 0);
3041 s->dlgret = ssh->user_response;
3042 }
3043 ssh_set_frozen(ssh, 0);
3044
3045 if (s->dlgret == 0) {
3046 ssh_disconnect(ssh, "User aborted at host key verification",
3047 NULL, 0, TRUE);
3048 crStop(0);
3049 }
3050 }
3051
3052 for (i = 0; i < 32; i++) {
3053 s->rsabuf[i] = ssh->session_key[i];
3054 if (i < 16)
3055 s->rsabuf[i] ^= s->session_id[i];
3056 }
3057
3058 if (hostkey.bytes > servkey.bytes) {
3059 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3060 if (ret)
3061 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3062 } else {
3063 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3064 if (ret)
3065 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3066 }
3067 if (!ret) {
3068 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3069 crStop(0);
3070 }
3071
3072 logevent("Encrypted session key");
3073
3074 {
3075 int cipher_chosen = 0, warn = 0;
3076 char *cipher_string = NULL;
3077 int i;
3078 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3079 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3080 if (next_cipher == CIPHER_WARN) {
3081 /* If/when we choose a cipher, warn about it */
3082 warn = 1;
3083 } else if (next_cipher == CIPHER_AES) {
3084 /* XXX Probably don't need to mention this. */
3085 logevent("AES not supported in SSH-1, skipping");
3086 } else {
3087 switch (next_cipher) {
3088 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3089 cipher_string = "3DES"; break;
3090 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3091 cipher_string = "Blowfish"; break;
3092 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3093 cipher_string = "single-DES"; break;
3094 }
3095 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3096 cipher_chosen = 1;
3097 }
3098 }
3099 if (!cipher_chosen) {
3100 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3101 bombout(("Server violates SSH-1 protocol by not "
3102 "supporting 3DES encryption"));
3103 else
3104 /* shouldn't happen */
3105 bombout(("No supported ciphers found"));
3106 crStop(0);
3107 }
3108
3109 /* Warn about chosen cipher if necessary. */
3110 if (warn) {
3111 ssh_set_frozen(ssh, 1);
3112 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3113 ssh_dialog_callback, ssh);
3114 if (s->dlgret < 0) {
3115 do {
3116 crReturn(0);
3117 if (pktin) {
3118 bombout(("Unexpected data from server while waiting"
3119 " for user response"));
3120 crStop(0);
3121 }
3122 } while (pktin || inlen > 0);
3123 s->dlgret = ssh->user_response;
3124 }
3125 ssh_set_frozen(ssh, 0);
3126 if (s->dlgret == 0) {
3127 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3128 0, TRUE);
3129 crStop(0);
3130 }
3131 }
3132 }
3133
3134 switch (s->cipher_type) {
3135 case SSH_CIPHER_3DES:
3136 logevent("Using 3DES encryption");
3137 break;
3138 case SSH_CIPHER_DES:
3139 logevent("Using single-DES encryption");
3140 break;
3141 case SSH_CIPHER_BLOWFISH:
3142 logevent("Using Blowfish encryption");
3143 break;
3144 }
3145
3146 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3147 PKT_CHAR, s->cipher_type,
3148 PKT_DATA, cookie, 8,
3149 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3150 PKT_DATA, s->rsabuf, s->len,
3151 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3152
3153 logevent("Trying to enable encryption...");
3154
3155 sfree(s->rsabuf);
3156
3157 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3158 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3159 &ssh_3des);
3160 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3161 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3162 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3163
3164 ssh->crcda_ctx = crcda_make_context();
3165 logevent("Installing CRC compensation attack detector");
3166
3167 if (servkey.modulus) {
3168 sfree(servkey.modulus);
3169 servkey.modulus = NULL;
3170 }
3171 if (servkey.exponent) {
3172 sfree(servkey.exponent);
3173 servkey.exponent = NULL;
3174 }
3175 if (hostkey.modulus) {
3176 sfree(hostkey.modulus);
3177 hostkey.modulus = NULL;
3178 }
3179 if (hostkey.exponent) {
3180 sfree(hostkey.exponent);
3181 hostkey.exponent = NULL;
3182 }
3183 crWaitUntil(pktin);
3184
3185 if (pktin->type != SSH1_SMSG_SUCCESS) {
3186 bombout(("Encryption not successfully enabled"));
3187 crStop(0);
3188 }
3189
3190 logevent("Successfully started encryption");
3191
3192 fflush(stdout);
3193 {
3194 if (!*ssh->cfg.username) {
3195 if (ssh_get_line && !ssh_getline_pw_only) {
3196 if (!ssh_get_line("login as: ",
3197 s->username, sizeof(s->username), FALSE)) {
3198 /*
3199 * get_line failed to get a username.
3200 * Terminate.
3201 */
3202 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3203 crStop(1);
3204 }
3205 } else {
3206 int ret; /* need not be kept over crReturn */
3207 c_write_str(ssh, "login as: ");
3208 ssh->send_ok = 1;
3209
3210 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3211 do {
3212 crWaitUntil(!pktin);
3213 ret = process_userpass_input(ssh, in, inlen);
3214 } while (ret == 0);
3215 if (ret < 0)
3216 cleanup_exit(0);
3217 c_write_str(ssh, "\r\n");
3218 }
3219 } else {
3220 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3221 s->username[sizeof(s->username)-1] = '\0';
3222 }
3223
3224 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3225 {
3226 char userlog[22 + sizeof(s->username)];
3227 sprintf(userlog, "Sent username \"%s\"", s->username);
3228 logevent(userlog);
3229 if (flags & FLAG_INTERACTIVE &&
3230 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3231 strcat(userlog, "\r\n");
3232 c_write_str(ssh, userlog);
3233 }
3234 }
3235 }
3236
3237 crWaitUntil(pktin);
3238
3239 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3240 /* We must not attempt PK auth. Pretend we've already tried it. */
3241 s->tried_publickey = s->tried_agent = 1;
3242 } else {
3243 s->tried_publickey = s->tried_agent = 0;
3244 }
3245 s->tis_auth_refused = s->ccard_auth_refused = 0;
3246 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3247 if (!filename_is_null(ssh->cfg.keyfile)) {
3248 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3249 &s->publickey_blob, &s->publickey_bloblen, NULL))
3250 s->publickey_blob = NULL;
3251 } else
3252 s->publickey_blob = NULL;
3253
3254 while (pktin->type == SSH1_SMSG_FAILURE) {
3255 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3256
3257 if (agent_exists() && !s->tried_agent) {
3258 /*
3259 * Attempt RSA authentication using Pageant.
3260 */
3261 void *r;
3262
3263 s->authed = FALSE;
3264 s->tried_agent = 1;
3265 logevent("Pageant is running. Requesting keys.");
3266
3267 /* Request the keys held by the agent. */
3268 PUT_32BIT(s->request, 1);
3269 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3270 if (!agent_query(s->request, 5, &r, &s->responselen,
3271 ssh_agent_callback, ssh)) {
3272 do {
3273 crReturn(0);
3274 if (pktin) {
3275 bombout(("Unexpected data from server while waiting"
3276 " for agent response"));
3277 crStop(0);
3278 }
3279 } while (pktin || inlen > 0);
3280 r = ssh->agent_response;
3281 s->responselen = ssh->agent_response_len;
3282 }
3283 s->response = (unsigned char *) r;
3284 if (s->response && s->responselen >= 5 &&
3285 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3286 s->p = s->response + 5;
3287 s->nkeys = GET_32BIT(s->p);
3288 s->p += 4;
3289 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3290 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3291 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3292 if (s->publickey_blob &&
3293 !memcmp(s->p, s->publickey_blob,
3294 s->publickey_bloblen)) {
3295 logevent("This key matches configured key file");
3296 s->tried_publickey = 1;
3297 }
3298 s->p += 4;
3299 {
3300 int n, ok = FALSE;
3301 do { /* do while (0) to make breaking easy */
3302 n = ssh1_read_bignum
3303 (s->p, s->responselen-(s->p-s->response),
3304 &s->key.exponent);
3305 if (n < 0)
3306 break;
3307 s->p += n;
3308 n = ssh1_read_bignum
3309 (s->p, s->responselen-(s->p-s->response),
3310 &s->key.modulus);
3311 if (n < 0)
3312 break;
3313 s->p += n;
3314 if (s->responselen - (s->p-s->response) < 4)
3315 break;
3316 s->commentlen = GET_32BIT(s->p);
3317 s->p += 4;
3318 if (s->responselen - (s->p-s->response) <
3319 s->commentlen)
3320 break;
3321 s->commentp = (char *)s->p;
3322 s->p += s->commentlen;
3323 ok = TRUE;
3324 } while (0);
3325 if (!ok) {
3326 logevent("Pageant key list packet was truncated");
3327 break;
3328 }
3329 }
3330 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3331 PKT_BIGNUM, s->key.modulus, PKT_END);
3332 crWaitUntil(pktin);
3333 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3334 logevent("Key refused");
3335 continue;
3336 }
3337 logevent("Received RSA challenge");
3338 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3339 bombout(("Server's RSA challenge was badly formatted"));
3340 crStop(0);
3341 }
3342
3343 {
3344 char *agentreq, *q, *ret;
3345 void *vret;
3346 int len, retlen;
3347 len = 1 + 4; /* message type, bit count */
3348 len += ssh1_bignum_length(s->key.exponent);
3349 len += ssh1_bignum_length(s->key.modulus);
3350 len += ssh1_bignum_length(s->challenge);
3351 len += 16; /* session id */
3352 len += 4; /* response format */
3353 agentreq = snewn(4 + len, char);
3354 PUT_32BIT(agentreq, len);
3355 q = agentreq + 4;
3356 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3357 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3358 q += 4;
3359 q += ssh1_write_bignum(q, s->key.exponent);
3360 q += ssh1_write_bignum(q, s->key.modulus);
3361 q += ssh1_write_bignum(q, s->challenge);
3362 memcpy(q, s->session_id, 16);
3363 q += 16;
3364 PUT_32BIT(q, 1); /* response format */
3365 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3366 ssh_agent_callback, ssh)) {
3367 sfree(agentreq);
3368 do {
3369 crReturn(0);
3370 if (pktin) {
3371 bombout(("Unexpected data from server"
3372 " while waiting for agent"
3373 " response"));
3374 crStop(0);
3375 }
3376 } while (pktin || inlen > 0);
3377 vret = ssh->agent_response;
3378 retlen = ssh->agent_response_len;
3379 } else
3380 sfree(agentreq);
3381 ret = vret;
3382 if (ret) {
3383 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3384 logevent("Sending Pageant's response");
3385 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3386 PKT_DATA, ret + 5, 16,
3387 PKT_END);
3388 sfree(ret);
3389 crWaitUntil(pktin);
3390 if (pktin->type == SSH1_SMSG_SUCCESS) {
3391 logevent
3392 ("Pageant's response accepted");
3393 if (flags & FLAG_VERBOSE) {
3394 c_write_str(ssh, "Authenticated using"
3395 " RSA key \"");
3396 c_write(ssh, s->commentp,
3397 s->commentlen);
3398 c_write_str(ssh, "\" from agent\r\n");
3399 }
3400 s->authed = TRUE;
3401 } else
3402 logevent
3403 ("Pageant's response not accepted");
3404 } else {
3405 logevent
3406 ("Pageant failed to answer challenge");
3407 sfree(ret);
3408 }
3409 } else {
3410 logevent("No reply received from Pageant");
3411 }
3412 }
3413 freebn(s->key.exponent);
3414 freebn(s->key.modulus);
3415 freebn(s->challenge);
3416 if (s->authed)
3417 break;
3418 }
3419 sfree(s->response);
3420 }
3421 if (s->authed)
3422 break;
3423 }
3424 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3425 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3426
3427 if (ssh->cfg.try_tis_auth &&
3428 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3429 !s->tis_auth_refused) {
3430 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3431 logevent("Requested TIS authentication");
3432 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3433 crWaitUntil(pktin);
3434 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3435 logevent("TIS authentication declined");
3436 if (flags & FLAG_INTERACTIVE)
3437 c_write_str(ssh, "TIS authentication refused.\r\n");
3438 s->tis_auth_refused = 1;
3439 continue;
3440 } else {
3441 char *challenge;
3442 int challengelen;
3443
3444 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3445 if (!challenge) {
3446 bombout(("TIS challenge packet was badly formed"));
3447 crStop(0);
3448 }
3449 c_write_str(ssh, "Using TIS authentication.\r\n");
3450 logevent("Received TIS challenge");
3451 if (challengelen > sizeof(s->prompt) - 1)
3452 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3453 memcpy(s->prompt, challenge, challengelen);
3454 /* Prompt heuristic comes from OpenSSH */
3455 strncpy(s->prompt + challengelen,
3456 memchr(s->prompt, '\n', challengelen) ?
3457 "": "\r\nResponse: ",
3458 (sizeof s->prompt) - challengelen);
3459 s->prompt[(sizeof s->prompt) - 1] = '\0';
3460 }
3461 }
3462 if (ssh->cfg.try_tis_auth &&
3463 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3464 !s->ccard_auth_refused) {
3465 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3466 logevent("Requested CryptoCard authentication");
3467 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3468 crWaitUntil(pktin);
3469 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3470 logevent("CryptoCard authentication declined");
3471 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3472 s->ccard_auth_refused = 1;
3473 continue;
3474 } else {
3475 char *challenge;
3476 int challengelen;
3477
3478 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3479 if (!challenge) {
3480 bombout(("CryptoCard challenge packet was badly formed"));
3481 crStop(0);
3482 }
3483 c_write_str(ssh, "Using CryptoCard authentication.\r\n");
3484 logevent("Received CryptoCard challenge");
3485 if (challengelen > sizeof(s->prompt) - 1)
3486 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3487 memcpy(s->prompt, challenge, challengelen);
3488 strncpy(s->prompt + challengelen,
3489 memchr(s->prompt, '\n', challengelen) ?
3490 "" : "\r\nResponse: ",
3491 sizeof(s->prompt) - challengelen);
3492 s->prompt[sizeof(s->prompt) - 1] = '\0';
3493 }
3494 }
3495 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3496 sprintf(s->prompt, "%.90s@%.90s's password: ",
3497 s->username, ssh->savedhost);
3498 }
3499 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3500 char *comment = NULL;
3501 int type;
3502 if (flags & FLAG_VERBOSE)
3503 c_write_str(ssh, "Trying public key authentication.\r\n");
3504 logeventf(ssh, "Trying public key \"%s\"",
3505 filename_to_str(&ssh->cfg.keyfile));
3506 type = key_type(&ssh->cfg.keyfile);
3507 if (type != SSH_KEYTYPE_SSH1) {
3508 char *msg = dupprintf("Key is of wrong type (%s)",
3509 key_type_to_str(type));
3510 logevent(msg);
3511 c_write_str(ssh, msg);
3512 c_write_str(ssh, "\r\n");
3513 sfree(msg);
3514 s->tried_publickey = 1;
3515 continue;
3516 }
3517 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3518 if (flags & FLAG_VERBOSE)
3519 c_write_str(ssh, "No passphrase required.\r\n");
3520 goto tryauth;
3521 }
3522 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3523 sfree(comment);
3524 }
3525
3526 /*
3527 * Show password prompt, having first obtained it via a TIS
3528 * or CryptoCard exchange if we're doing TIS or CryptoCard
3529 * authentication.
3530 */
3531 if (ssh_get_line) {
3532 if (!ssh_get_line(s->prompt, s->password,
3533 sizeof(s->password), TRUE)) {
3534 /*
3535 * get_line failed to get a password (for example
3536 * because one was supplied on the command line
3537 * which has already failed to work). Terminate.
3538 */
3539 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, FALSE);
3540 crStop(1);
3541 }
3542 } else {
3543 /* Prompt may have come from server. We've munged it a bit, so
3544 * we know it to be zero-terminated at least once. */
3545 int ret; /* need not be saved over crReturn */
3546 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3547 s->pos = 0;
3548
3549 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3550 do {
3551 crWaitUntil(!pktin);
3552 ret = process_userpass_input(ssh, in, inlen);
3553 } while (ret == 0);
3554 if (ret < 0)
3555 cleanup_exit(0);
3556 c_write_str(ssh, "\r\n");
3557 }
3558
3559 tryauth:
3560 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3561 /*
3562 * Try public key authentication with the specified
3563 * key file.
3564 */
3565 s->tried_publickey = 1;
3566
3567 {
3568 const char *error = NULL;
3569 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3570 &error);
3571 if (ret == 0) {
3572 c_write_str(ssh, "Couldn't load private key from ");
3573 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3574 c_write_str(ssh, " (");
3575 c_write_str(ssh, error);
3576 c_write_str(ssh, ").\r\n");
3577 continue; /* go and try password */
3578 }
3579 if (ret == -1) {
3580 c_write_str(ssh, "Wrong passphrase.\r\n");
3581 s->tried_publickey = 0;
3582 continue; /* try again */
3583 }
3584 }
3585
3586 /*
3587 * Send a public key attempt.
3588 */
3589 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3590 PKT_BIGNUM, s->key.modulus, PKT_END);
3591
3592 crWaitUntil(pktin);
3593 if (pktin->type == SSH1_SMSG_FAILURE) {
3594 c_write_str(ssh, "Server refused our public key.\r\n");
3595 continue; /* go and try password */
3596 }
3597 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3598 bombout(("Bizarre response to offer of public key"));
3599 crStop(0);
3600 }
3601
3602 {
3603 int i;
3604 unsigned char buffer[32];
3605 Bignum challenge, response;
3606
3607 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3608 bombout(("Server's RSA challenge was badly formatted"));
3609 crStop(0);
3610 }
3611 response = rsadecrypt(challenge, &s->key);
3612 freebn(s->key.private_exponent);/* burn the evidence */
3613
3614 for (i = 0; i < 32; i++) {
3615 buffer[i] = bignum_byte(response, 31 - i);
3616 }
3617
3618 MD5Init(&md5c);
3619 MD5Update(&md5c, buffer, 32);
3620 MD5Update(&md5c, s->session_id, 16);
3621 MD5Final(buffer, &md5c);
3622
3623 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3624 PKT_DATA, buffer, 16, PKT_END);
3625
3626 freebn(challenge);
3627 freebn(response);
3628 }
3629
3630 crWaitUntil(pktin);
3631 if (pktin->type == SSH1_SMSG_FAILURE) {
3632 if (flags & FLAG_VERBOSE)
3633 c_write_str(ssh, "Failed to authenticate with"
3634 " our public key.\r\n");
3635 continue; /* go and try password */
3636 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3637 bombout(("Bizarre response to RSA authentication response"));
3638 crStop(0);
3639 }
3640
3641 break; /* we're through! */
3642 } else {
3643 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3644 /*
3645 * Defence against traffic analysis: we send a
3646 * whole bunch of packets containing strings of
3647 * different lengths. One of these strings is the
3648 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3649 * The others are all random data in
3650 * SSH1_MSG_IGNORE packets. This way a passive
3651 * listener can't tell which is the password, and
3652 * hence can't deduce the password length.
3653 *
3654 * Anybody with a password length greater than 16
3655 * bytes is going to have enough entropy in their
3656 * password that a listener won't find it _that_
3657 * much help to know how long it is. So what we'll
3658 * do is:
3659 *
3660 * - if password length < 16, we send 15 packets
3661 * containing string lengths 1 through 15
3662 *
3663 * - otherwise, we let N be the nearest multiple
3664 * of 8 below the password length, and send 8
3665 * packets containing string lengths N through
3666 * N+7. This won't obscure the order of
3667 * magnitude of the password length, but it will
3668 * introduce a bit of extra uncertainty.
3669 *
3670 * A few servers (the old 1.2.18 through 1.2.22)
3671 * can't deal with SSH1_MSG_IGNORE. For these
3672 * servers, we need an alternative defence. We make
3673 * use of the fact that the password is interpreted
3674 * as a C string: so we can append a NUL, then some
3675 * random data.
3676 *
3677 * One server (a Cisco one) can deal with neither
3678 * SSH1_MSG_IGNORE _nor_ a padded password string.
3679 * For this server we are left with no defences
3680 * against password length sniffing.
3681 */
3682 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3683 /*
3684 * The server can deal with SSH1_MSG_IGNORE, so
3685 * we can use the primary defence.
3686 */
3687 int bottom, top, pwlen, i;
3688 char *randomstr;
3689
3690 pwlen = strlen(s->password);
3691 if (pwlen < 16) {
3692 bottom = 0; /* zero length passwords are OK! :-) */
3693 top = 15;
3694 } else {
3695 bottom = pwlen & ~7;
3696 top = bottom + 7;
3697 }
3698
3699 assert(pwlen >= bottom && pwlen <= top);
3700
3701 randomstr = snewn(top + 1, char);
3702
3703 for (i = bottom; i <= top; i++) {
3704 if (i == pwlen) {
3705 defer_packet(ssh, s->pwpkt_type,
3706 PKTT_PASSWORD, PKT_STR, s->password,
3707 PKTT_OTHER, PKT_END);
3708 } else {
3709 for (j = 0; j < i; j++) {
3710 do {
3711 randomstr[j] = random_byte();
3712 } while (randomstr[j] == '\0');
3713 }
3714 randomstr[i] = '\0';
3715 defer_packet(ssh, SSH1_MSG_IGNORE,
3716 PKT_STR, randomstr, PKT_END);
3717 }
3718 }
3719 logevent("Sending password with camouflage packets");
3720 ssh_pkt_defersend(ssh);
3721 sfree(randomstr);
3722 }
3723 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3724 /*
3725 * The server can't deal with SSH1_MSG_IGNORE
3726 * but can deal with padded passwords, so we
3727 * can use the secondary defence.
3728 */
3729 char string[64];
3730 char *ss;
3731 int len;
3732
3733 len = strlen(s->password);
3734 if (len < sizeof(string)) {
3735 ss = string;
3736 strcpy(string, s->password);
3737 len++; /* cover the zero byte */
3738 while (len < sizeof(string)) {
3739 string[len++] = (char) random_byte();
3740 }
3741 } else {
3742 ss = s->password;
3743 }
3744 logevent("Sending length-padded password");
3745 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3746 PKT_INT, len, PKT_DATA, ss, len,
3747 PKTT_OTHER, PKT_END);
3748 } else {
3749 /*
3750 * The server has _both_
3751 * BUG_CHOKES_ON_SSH1_IGNORE and
3752 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3753 * therefore nothing we can do.
3754 */
3755 int len;
3756 len = strlen(s->password);
3757 logevent("Sending unpadded password");
3758 send_packet(ssh, s->pwpkt_type,
3759 PKTT_PASSWORD, PKT_INT, len,
3760 PKT_DATA, s->password, len,
3761 PKTT_OTHER, PKT_END);
3762 }
3763 } else {
3764 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3765 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3766 }
3767 }
3768 logevent("Sent password");
3769 memset(s->password, 0, strlen(s->password));
3770 crWaitUntil(pktin);
3771 if (pktin->type == SSH1_SMSG_FAILURE) {
3772 if (flags & FLAG_VERBOSE)
3773 c_write_str(ssh, "Access denied\r\n");
3774 logevent("Authentication refused");
3775 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3776 bombout(("Strange packet received, type %d", pktin->type));
3777 crStop(0);
3778 }
3779 }
3780
3781 logevent("Authentication successful");
3782
3783 crFinish(1);
3784 }
3785
3786 void sshfwd_close(struct ssh_channel *c)
3787 {
3788 Ssh ssh = c->ssh;
3789
3790 if (ssh->state == SSH_STATE_CLOSED)
3791 return;
3792
3793 if (c && !c->closes) {
3794 /*
3795 * If halfopen is true, we have sent
3796 * CHANNEL_OPEN for this channel, but it hasn't even been
3797 * acknowledged by the server. So we must set a close flag
3798 * on it now, and then when the server acks the channel
3799 * open, we can close it then.
3800 */
3801 if (!c->halfopen) {
3802 if (ssh->version == 1) {
3803 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3804 PKT_END);
3805 } else {
3806 struct Packet *pktout;
3807 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3808 ssh2_pkt_adduint32(pktout, c->remoteid);
3809 ssh2_pkt_send(ssh, pktout);
3810 }
3811 }
3812 c->closes = 1; /* sent MSG_CLOSE */
3813 if (c->type == CHAN_X11) {
3814 c->u.x11.s = NULL;
3815 logevent("Forwarded X11 connection terminated");
3816 } else if (c->type == CHAN_SOCKDATA ||
3817 c->type == CHAN_SOCKDATA_DORMANT) {
3818 c->u.pfd.s = NULL;
3819 logevent("Forwarded port closed");
3820 }
3821 }
3822 }
3823
3824 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3825 {
3826 Ssh ssh = c->ssh;
3827
3828 if (ssh->state == SSH_STATE_CLOSED)
3829 return 0;
3830
3831 if (ssh->version == 1) {
3832 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3833 PKT_INT, c->remoteid,
3834 PKTT_DATA,
3835 PKT_INT, len, PKT_DATA, buf, len,
3836 PKTT_OTHER, PKT_END);
3837 /*
3838 * In SSH-1 we can return 0 here - implying that forwarded
3839 * connections are never individually throttled - because
3840 * the only circumstance that can cause throttling will be
3841 * the whole SSH connection backing up, in which case
3842 * _everything_ will be throttled as a whole.
3843 */
3844 return 0;
3845 } else {
3846 ssh2_add_channel_data(c, buf, len);
3847 return ssh2_try_send(c);
3848 }
3849 }
3850
3851 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3852 {
3853 Ssh ssh = c->ssh;
3854
3855 if (ssh->state == SSH_STATE_CLOSED)
3856 return;
3857
3858 if (ssh->version == 1) {
3859 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3860 c->v.v1.throttling = 0;
3861 ssh1_throttle(ssh, -1);
3862 }
3863 } else {
3864 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3865 }
3866 }
3867
3868 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3869 {
3870 struct queued_handler *qh = ssh->qhead;
3871
3872 assert(qh != NULL);
3873
3874 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3875
3876 if (qh->msg1 > 0) {
3877 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3878 ssh->packet_dispatch[qh->msg1] = NULL;
3879 }
3880 if (qh->msg2 > 0) {
3881 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3882 ssh->packet_dispatch[qh->msg2] = NULL;
3883 }
3884
3885 if (qh->next) {
3886 ssh->qhead = qh->next;
3887
3888 if (ssh->qhead->msg1 > 0) {
3889 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3890 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3891 }
3892 if (ssh->qhead->msg2 > 0) {
3893 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3894 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3895 }
3896 } else {
3897 ssh->qhead = ssh->qtail = NULL;
3898 ssh->packet_dispatch[pktin->type] = NULL;
3899 }
3900
3901 qh->handler(ssh, pktin, qh->ctx);
3902
3903 sfree(qh);
3904 }
3905
3906 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3907 chandler_fn_t handler, void *ctx)
3908 {
3909 struct queued_handler *qh;
3910
3911 qh = snew(struct queued_handler);
3912 qh->msg1 = msg1;
3913 qh->msg2 = msg2;
3914 qh->handler = handler;
3915 qh->ctx = ctx;
3916 qh->next = NULL;
3917
3918 if (ssh->qtail == NULL) {
3919 ssh->qhead = qh;
3920
3921 if (qh->msg1 > 0) {
3922 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3923 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3924 }
3925 if (qh->msg2 > 0) {
3926 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3927 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3928 }
3929 } else {
3930 ssh->qtail->next = qh;
3931 }
3932 ssh->qtail = qh;
3933 }
3934
3935 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3936 {
3937 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3938
3939 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3940 SSH2_MSG_REQUEST_SUCCESS)) {
3941 logeventf(ssh, "Remote port forwarding from %s enabled",
3942 pf->sportdesc);
3943 } else {
3944 logeventf(ssh, "Remote port forwarding from %s refused",
3945 pf->sportdesc);
3946
3947 rpf = del234(ssh->rportfwds, pf);
3948 assert(rpf == pf);
3949 free_rportfwd(pf);
3950 }
3951 }
3952
3953 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3954 {
3955 const char *portfwd_strptr = cfg->portfwd;
3956 struct ssh_portfwd *epf;
3957 int i;
3958
3959 if (!ssh->portfwds) {
3960 ssh->portfwds = newtree234(ssh_portcmp);
3961 } else {
3962 /*
3963 * Go through the existing port forwardings and tag them
3964 * with status==DESTROY. Any that we want to keep will be
3965 * re-enabled (status==KEEP) as we go through the
3966 * configuration and find out which bits are the same as
3967 * they were before.
3968 */
3969 struct ssh_portfwd *epf;
3970 int i;
3971 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3972 epf->status = DESTROY;
3973 }
3974
3975 while (*portfwd_strptr) {
3976 char address_family, type;
3977 int sport,dport,sserv,dserv;
3978 char sports[256], dports[256], saddr[256], host[256];
3979 int n;
3980
3981 address_family = 'A';
3982 type = 'L';
3983 if (*portfwd_strptr == 'A' ||
3984 *portfwd_strptr == '4' ||
3985 *portfwd_strptr == '6')
3986 address_family = *portfwd_strptr++;
3987 if (*portfwd_strptr == 'L' ||
3988 *portfwd_strptr == 'R' ||
3989 *portfwd_strptr == 'D')
3990 type = *portfwd_strptr++;
3991
3992 saddr[0] = '\0';
3993
3994 n = 0;
3995 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3996 if (*portfwd_strptr == ':') {
3997 /*
3998 * We've seen a colon in the middle of the
3999 * source port number. This means that
4000 * everything we've seen until now is the
4001 * source _address_, so we'll move it into
4002 * saddr and start sports from the beginning
4003 * again.
4004 */
4005 portfwd_strptr++;
4006 sports[n] = '\0';
4007 if (ssh->version == 1 && type == 'R') {
4008 logeventf(ssh, "SSH-1 cannot handle remote source address "
4009 "spec \"%s\"; ignoring", sports);
4010 } else
4011 strcpy(saddr, sports);
4012 n = 0;
4013 }
4014 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4015 }
4016 sports[n] = 0;
4017 if (type != 'D') {
4018 if (*portfwd_strptr == '\t')
4019 portfwd_strptr++;
4020 n = 0;
4021 while (*portfwd_strptr && *portfwd_strptr != ':') {
4022 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4023 }
4024 host[n] = 0;
4025 if (*portfwd_strptr == ':')
4026 portfwd_strptr++;
4027 n = 0;
4028 while (*portfwd_strptr) {
4029 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4030 }
4031 dports[n] = 0;
4032 portfwd_strptr++;
4033 dport = atoi(dports);
4034 dserv = 0;
4035 if (dport == 0) {
4036 dserv = 1;
4037 dport = net_service_lookup(dports);
4038 if (!dport) {
4039 logeventf(ssh, "Service lookup failed for destination"
4040 " port \"%s\"", dports);
4041 }
4042 }
4043 } else {
4044 while (*portfwd_strptr) portfwd_strptr++;
4045 host[0] = 0;
4046 dports[0] = 0;
4047 dport = dserv = -1;
4048 portfwd_strptr++; /* eat the NUL and move to next one */
4049 }
4050 sport = atoi(sports);
4051 sserv = 0;
4052 if (sport == 0) {
4053 sserv = 1;
4054 sport = net_service_lookup(sports);
4055 if (!sport) {
4056 logeventf(ssh, "Service lookup failed for source"
4057 " port \"%s\"", sports);
4058 }
4059 }
4060 if (sport && dport) {
4061 /* Set up a description of the source port. */
4062 struct ssh_portfwd *pfrec, *epfrec;
4063
4064 pfrec = snew(struct ssh_portfwd);
4065 pfrec->type = type;
4066 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4067 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4068 pfrec->sport = sport;
4069 pfrec->daddr = *host ? dupstr(host) : NULL;
4070 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4071 pfrec->dport = dport;
4072 pfrec->local = NULL;
4073 pfrec->remote = NULL;
4074 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4075 address_family == '6' ? ADDRTYPE_IPV6 :
4076 ADDRTYPE_UNSPEC);
4077
4078 epfrec = add234(ssh->portfwds, pfrec);
4079 if (epfrec != pfrec) {
4080 /*
4081 * We already have a port forwarding with precisely
4082 * these parameters. Hence, no need to do anything;
4083 * simply tag the existing one as KEEP.
4084 */
4085 epfrec->status = KEEP;
4086 free_portfwd(pfrec);
4087 } else {
4088 pfrec->status = CREATE;
4089 }
4090 }
4091 }
4092
4093 /*
4094 * Now go through and destroy any port forwardings which were
4095 * not re-enabled.
4096 */
4097 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4098 if (epf->status == DESTROY) {
4099 char *message;
4100
4101 message = dupprintf("%s port forwarding from %s%s%d",
4102 epf->type == 'L' ? "local" :
4103 epf->type == 'R' ? "remote" : "dynamic",
4104 epf->saddr ? epf->saddr : "",
4105 epf->saddr ? ":" : "",
4106 epf->sport);
4107
4108 if (epf->type != 'D') {
4109 char *msg2 = dupprintf("%s to %s:%d", message,
4110 epf->daddr, epf->dport);
4111 sfree(message);
4112 message = msg2;
4113 }
4114
4115 logeventf(ssh, "Cancelling %s", message);
4116 sfree(message);
4117
4118 if (epf->remote) {
4119 struct ssh_rportfwd *rpf = epf->remote;
4120 struct Packet *pktout;
4121
4122 /*
4123 * Cancel the port forwarding at the server
4124 * end.
4125 */
4126 if (ssh->version == 1) {
4127 /*
4128 * We cannot cancel listening ports on the
4129 * server side in SSH-1! There's no message
4130 * to support it. Instead, we simply remove
4131 * the rportfwd record from the local end
4132 * so that any connections the server tries
4133 * to make on it are rejected.
4134 */
4135 } else {
4136 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4137 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4138 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4139 if (epf->saddr) {
4140 ssh2_pkt_addstring(pktout, epf->saddr);
4141 } else if (ssh->cfg.rport_acceptall) {
4142 /* XXX: ssh->cfg.rport_acceptall may not represent
4143 * what was used to open the original connection,
4144 * since it's reconfigurable. */
4145 ssh2_pkt_addstring(pktout, "0.0.0.0");
4146 } else {
4147 ssh2_pkt_addstring(pktout, "127.0.0.1");
4148 }
4149 ssh2_pkt_adduint32(pktout, epf->sport);
4150 ssh2_pkt_send(ssh, pktout);
4151 }
4152
4153 del234(ssh->rportfwds, rpf);
4154 free_rportfwd(rpf);
4155 } else if (epf->local) {
4156 pfd_terminate(epf->local);
4157 }
4158
4159 delpos234(ssh->portfwds, i);
4160 free_portfwd(epf);
4161 i--; /* so we don't skip one in the list */
4162 }
4163
4164 /*
4165 * And finally, set up any new port forwardings (status==CREATE).
4166 */
4167 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4168 if (epf->status == CREATE) {
4169 char *sportdesc, *dportdesc;
4170 sportdesc = dupprintf("%s%s%s%s%d%s",
4171 epf->saddr ? epf->saddr : "",
4172 epf->saddr ? ":" : "",
4173 epf->sserv ? epf->sserv : "",
4174 epf->sserv ? "(" : "",
4175 epf->sport,
4176 epf->sserv ? ")" : "");
4177 if (epf->type == 'D') {
4178 dportdesc = NULL;
4179 } else {
4180 dportdesc = dupprintf("%s:%s%s%d%s",
4181 epf->daddr,
4182 epf->dserv ? epf->dserv : "",
4183 epf->dserv ? "(" : "",
4184 epf->dport,
4185 epf->dserv ? ")" : "");
4186 }
4187
4188 if (epf->type == 'L') {
4189 const char *err = pfd_addforward(epf->daddr, epf->dport,
4190 epf->saddr, epf->sport,
4191 ssh, cfg,
4192 &epf->local,
4193 epf->addressfamily);
4194
4195 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4196 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4197 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4198 sportdesc, dportdesc,
4199 err ? " failed: " : "", err ? err : "");
4200 } else if (epf->type == 'D') {
4201 const char *err = pfd_addforward(NULL, -1,
4202 epf->saddr, epf->sport,
4203 ssh, cfg,
4204 &epf->local,
4205 epf->addressfamily);
4206
4207 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4208 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4209 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4210 sportdesc,
4211 err ? " failed: " : "", err ? err : "");
4212 } else {
4213 struct ssh_rportfwd *pf;
4214
4215 /*
4216 * Ensure the remote port forwardings tree exists.
4217 */
4218 if (!ssh->rportfwds) {
4219 if (ssh->version == 1)
4220 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4221 else
4222 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4223 }
4224
4225 pf = snew(struct ssh_rportfwd);
4226 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4227 pf->dhost[lenof(pf->dhost)-1] = '\0';
4228 pf->dport = epf->dport;
4229 pf->sport = epf->sport;
4230 if (add234(ssh->rportfwds, pf) != pf) {
4231 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4232 epf->daddr, epf->dport);
4233 sfree(pf);
4234 } else {
4235 logeventf(ssh, "Requesting remote port %s"
4236 " forward to %s", sportdesc, dportdesc);
4237
4238 pf->sportdesc = sportdesc;
4239 sportdesc = NULL;
4240 epf->remote = pf;
4241 pf->pfrec = epf;
4242
4243 if (ssh->version == 1) {
4244 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4245 PKT_INT, epf->sport,
4246 PKT_STR, epf->daddr,
4247 PKT_INT, epf->dport,
4248 PKT_END);
4249 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4250 SSH1_SMSG_FAILURE,
4251 ssh_rportfwd_succfail, pf);
4252 } else {
4253 struct Packet *pktout;
4254 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4255 ssh2_pkt_addstring(pktout, "tcpip-forward");
4256 ssh2_pkt_addbool(pktout, 1);/* want reply */
4257 if (epf->saddr) {
4258 ssh2_pkt_addstring(pktout, epf->saddr);
4259 } else if (cfg->rport_acceptall) {
4260 ssh2_pkt_addstring(pktout, "0.0.0.0");
4261 } else {
4262 ssh2_pkt_addstring(pktout, "127.0.0.1");
4263 }
4264 ssh2_pkt_adduint32(pktout, epf->sport);
4265 ssh2_pkt_send(ssh, pktout);
4266
4267 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4268 SSH2_MSG_REQUEST_FAILURE,
4269 ssh_rportfwd_succfail, pf);
4270 }
4271 }
4272 }
4273 sfree(sportdesc);
4274 sfree(dportdesc);
4275 }
4276 }
4277
4278 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4279 {
4280 char *string;
4281 int stringlen, bufsize;
4282
4283 ssh_pkt_getstring(pktin, &string, &stringlen);
4284 if (string == NULL) {
4285 bombout(("Incoming terminal data packet was badly formed"));
4286 return;
4287 }
4288
4289 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4290 string, stringlen);
4291 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4292 ssh->v1_stdout_throttling = 1;
4293 ssh1_throttle(ssh, +1);
4294 }
4295 }
4296
4297 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4298 {
4299 /* Remote side is trying to open a channel to talk to our
4300 * X-Server. Give them back a local channel number. */
4301 struct ssh_channel *c;
4302 int remoteid = ssh_pkt_getuint32(pktin);
4303
4304 logevent("Received X11 connect request");
4305 /* Refuse if X11 forwarding is disabled. */
4306 if (!ssh->X11_fwd_enabled) {
4307 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4308 PKT_INT, remoteid, PKT_END);
4309 logevent("Rejected X11 connect request");
4310 } else {
4311 c = snew(struct ssh_channel);
4312 c->ssh = ssh;
4313
4314 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4315 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4316 logevent("Opening X11 forward connection failed");
4317 sfree(c);
4318 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4319 PKT_INT, remoteid, PKT_END);
4320 } else {
4321 logevent
4322 ("Opening X11 forward connection succeeded");
4323 c->remoteid = remoteid;
4324 c->halfopen = FALSE;
4325 c->localid = alloc_channel_id(ssh);
4326 c->closes = 0;
4327 c->v.v1.throttling = 0;
4328 c->type = CHAN_X11; /* identify channel type */
4329 add234(ssh->channels, c);
4330 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4331 PKT_INT, c->remoteid, PKT_INT,
4332 c->localid, PKT_END);
4333 logevent("Opened X11 forward channel");
4334 }
4335 }
4336 }
4337
4338 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4339 {
4340 /* Remote side is trying to open a channel to talk to our
4341 * agent. Give them back a local channel number. */
4342 struct ssh_channel *c;
4343 int remoteid = ssh_pkt_getuint32(pktin);
4344
4345 /* Refuse if agent forwarding is disabled. */
4346 if (!ssh->agentfwd_enabled) {
4347 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4348 PKT_INT, remoteid, PKT_END);
4349 } else {
4350 c = snew(struct ssh_channel);
4351 c->ssh = ssh;
4352 c->remoteid = remoteid;
4353 c->halfopen = FALSE;
4354 c->localid = alloc_channel_id(ssh);
4355 c->closes = 0;
4356 c->v.v1.throttling = 0;
4357 c->type = CHAN_AGENT; /* identify channel type */
4358 c->u.a.lensofar = 0;
4359 add234(ssh->channels, c);
4360 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4361 PKT_INT, c->remoteid, PKT_INT, c->localid,
4362 PKT_END);
4363 }
4364 }
4365
4366 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4367 {
4368 /* Remote side is trying to open a channel to talk to a
4369 * forwarded port. Give them back a local channel number. */
4370 struct ssh_channel *c;
4371 struct ssh_rportfwd pf, *pfp;
4372 int remoteid;
4373 int hostsize, port;
4374 char *host;
4375 const char *e;
4376 c = snew(struct ssh_channel);
4377 c->ssh = ssh;
4378
4379 remoteid = ssh_pkt_getuint32(pktin);
4380 ssh_pkt_getstring(pktin, &host, &hostsize);
4381 port = ssh_pkt_getuint32(pktin);
4382
4383 if (hostsize >= lenof(pf.dhost))
4384 hostsize = lenof(pf.dhost)-1;
4385 memcpy(pf.dhost, host, hostsize);
4386 pf.dhost[hostsize] = '\0';
4387 pf.dport = port;
4388 pfp = find234(ssh->rportfwds, &pf, NULL);
4389
4390 if (pfp == NULL) {
4391 logeventf(ssh, "Rejected remote port open request for %s:%d",
4392 pf.dhost, port);
4393 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4394 PKT_INT, remoteid, PKT_END);
4395 } else {
4396 logeventf(ssh, "Received remote port open request for %s:%d",
4397 pf.dhost, port);
4398 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4399 c, &ssh->cfg, pfp->pfrec->addressfamily);
4400 if (e != NULL) {
4401 logeventf(ssh, "Port open failed: %s", e);
4402 sfree(c);
4403 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4404 PKT_INT, remoteid, PKT_END);
4405 } else {
4406 c->remoteid = remoteid;
4407 c->halfopen = FALSE;
4408 c->localid = alloc_channel_id(ssh);
4409 c->closes = 0;
4410 c->v.v1.throttling = 0;
4411 c->type = CHAN_SOCKDATA; /* identify channel type */
4412 add234(ssh->channels, c);
4413 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4414 PKT_INT, c->remoteid, PKT_INT,
4415 c->localid, PKT_END);
4416 logevent("Forwarded port opened successfully");
4417 }
4418 }
4419 }
4420
4421 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4422 {
4423 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4424 unsigned int localid = ssh_pkt_getuint32(pktin);
4425 struct ssh_channel *c;
4426
4427 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4428 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4429 c->remoteid = localid;
4430 c->halfopen = FALSE;
4431 c->type = CHAN_SOCKDATA;
4432 c->v.v1.throttling = 0;
4433 pfd_confirm(c->u.pfd.s);
4434 }
4435
4436 if (c && c->closes) {
4437 /*
4438 * We have a pending close on this channel,
4439 * which we decided on before the server acked
4440 * the channel open. So now we know the
4441 * remoteid, we can close it again.
4442 */
4443 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4444 PKT_INT, c->remoteid, PKT_END);
4445 }
4446 }
4447
4448 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4449 {
4450 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4451 struct ssh_channel *c;
4452
4453 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4454 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4455 logevent("Forwarded connection refused by server");
4456 pfd_close(c->u.pfd.s);
4457 del234(ssh->channels, c);
4458 sfree(c);
4459 }
4460 }
4461
4462 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4463 {
4464 /* Remote side closes a channel. */
4465 unsigned i = ssh_pkt_getuint32(pktin);
4466 struct ssh_channel *c;
4467 c = find234(ssh->channels, &i, ssh_channelfind);
4468 if (c && !c->halfopen) {
4469 int closetype;
4470 closetype =
4471 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4472
4473 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4474 logevent("Forwarded X11 connection terminated");
4475 assert(c->u.x11.s != NULL);
4476 x11_close(c->u.x11.s);
4477 c->u.x11.s = NULL;
4478 }
4479 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4480 logevent("Forwarded port closed");
4481 assert(c->u.pfd.s != NULL);
4482 pfd_close(c->u.pfd.s);
4483 c->u.pfd.s = NULL;
4484 }
4485
4486 c->closes |= (closetype << 2); /* seen this message */
4487 if (!(c->closes & closetype)) {
4488 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4489 PKT_END);
4490 c->closes |= closetype; /* sent it too */
4491 }
4492
4493 if (c->closes == 15) {
4494 del234(ssh->channels, c);
4495 sfree(c);
4496 }
4497 } else {
4498 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4499 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4500 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4501 i));
4502 }
4503 }
4504
4505 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4506 {
4507 /* Data sent down one of our channels. */
4508 int i = ssh_pkt_getuint32(pktin);
4509 char *p;
4510 int len;
4511 struct ssh_channel *c;
4512
4513 ssh_pkt_getstring(pktin, &p, &len);
4514
4515 c = find234(ssh->channels, &i, ssh_channelfind);
4516 if (c) {
4517 int bufsize = 0;
4518 switch (c->type) {
4519 case CHAN_X11:
4520 bufsize = x11_send(c->u.x11.s, p, len);
4521 break;
4522 case CHAN_SOCKDATA:
4523 bufsize = pfd_send(c->u.pfd.s, p, len);
4524 break;
4525 case CHAN_AGENT:
4526 /* Data for an agent message. Buffer it. */
4527 while (len > 0) {
4528 if (c->u.a.lensofar < 4) {
4529 unsigned int l = min(4 - c->u.a.lensofar, len);
4530 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4531 l);
4532 p += l;
4533 len -= l;
4534 c->u.a.lensofar += l;
4535 }
4536 if (c->u.a.lensofar == 4) {
4537 c->u.a.totallen =
4538 4 + GET_32BIT(c->u.a.msglen);
4539 c->u.a.message = snewn(c->u.a.totallen,
4540 unsigned char);
4541 memcpy(c->u.a.message, c->u.a.msglen, 4);
4542 }
4543 if (c->u.a.lensofar >= 4 && len > 0) {
4544 unsigned int l =
4545 min(c->u.a.totallen - c->u.a.lensofar,
4546 len);
4547 memcpy(c->u.a.message + c->u.a.lensofar, p,
4548 l);
4549 p += l;
4550 len -= l;
4551 c->u.a.lensofar += l;
4552 }
4553 if (c->u.a.lensofar == c->u.a.totallen) {
4554 void *reply;
4555 int replylen;
4556 if (agent_query(c->u.a.message,
4557 c->u.a.totallen,
4558 &reply, &replylen,
4559 ssh_agentf_callback, c))
4560 ssh_agentf_callback(c, reply, replylen);
4561 sfree(c->u.a.message);
4562 c->u.a.lensofar = 0;
4563 }
4564 }
4565 bufsize = 0; /* agent channels never back up */
4566 break;
4567 }
4568 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4569 c->v.v1.throttling = 1;
4570 ssh1_throttle(ssh, +1);
4571 }
4572 }
4573 }
4574
4575 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4576 {
4577 ssh->exitcode = ssh_pkt_getuint32(pktin);
4578 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4579 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4580 /*
4581 * In case `helpful' firewalls or proxies tack
4582 * extra human-readable text on the end of the
4583 * session which we might mistake for another
4584 * encrypted packet, we close the session once
4585 * we've sent EXIT_CONFIRMATION.
4586 */
4587 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4588 }
4589
4590 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4591 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4592 {
4593 struct Packet *pktout = (struct Packet *)data;
4594 int i = 0;
4595 unsigned int arg = 0;
4596 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4597 if (i == lenof(ssh_ttymodes)) return;
4598 switch (ssh_ttymodes[i].type) {
4599 case TTY_OP_CHAR:
4600 arg = ssh_tty_parse_specchar(val);
4601 break;
4602 case TTY_OP_BOOL:
4603 arg = ssh_tty_parse_boolean(val);
4604 break;
4605 }
4606 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4607 ssh2_pkt_addbyte(pktout, arg);
4608 }
4609
4610
4611 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4612 struct Packet *pktin)
4613 {
4614 crBegin(ssh->do_ssh1_connection_crstate);
4615
4616 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4617 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4618 ssh1_smsg_stdout_stderr_data;
4619
4620 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4621 ssh1_msg_channel_open_confirmation;
4622 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4623 ssh1_msg_channel_open_failure;
4624 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4625 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4626 ssh1_msg_channel_close;
4627 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4628 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4629
4630 if (ssh->cfg.agentfwd && agent_exists()) {
4631 logevent("Requesting agent forwarding");
4632 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4633 do {
4634 crReturnV;
4635 } while (!pktin);
4636 if (pktin->type != SSH1_SMSG_SUCCESS
4637 && pktin->type != SSH1_SMSG_FAILURE) {
4638 bombout(("Protocol confusion"));
4639 crStopV;
4640 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4641 logevent("Agent forwarding refused");
4642 } else {
4643 logevent("Agent forwarding enabled");
4644 ssh->agentfwd_enabled = TRUE;
4645 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4646 }
4647 }
4648
4649 if (ssh->cfg.x11_forward) {
4650 char proto[20], data[64];
4651 logevent("Requesting X11 forwarding");
4652 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4653 data, sizeof(data), ssh->cfg.x11_auth);
4654 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4655 /*
4656 * Note that while we blank the X authentication data here, we don't
4657 * take any special action to blank the start of an X11 channel,
4658 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4659 * without having session blanking enabled is likely to leak your
4660 * cookie into the log.
4661 */
4662 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4663 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4664 PKT_STR, proto,
4665 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4666 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4667 PKT_END);
4668 } else {
4669 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4670 PKT_STR, proto,
4671 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4672 }
4673 do {
4674 crReturnV;
4675 } while (!pktin);
4676 if (pktin->type != SSH1_SMSG_SUCCESS
4677 && pktin->type != SSH1_SMSG_FAILURE) {
4678 bombout(("Protocol confusion"));
4679 crStopV;
4680 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4681 logevent("X11 forwarding refused");
4682 } else {
4683 logevent("X11 forwarding enabled");
4684 ssh->X11_fwd_enabled = TRUE;
4685 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4686 }
4687 }
4688
4689 ssh_setup_portfwd(ssh, &ssh->cfg);
4690 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4691
4692 if (!ssh->cfg.nopty) {
4693 struct Packet *pkt;
4694 /* Unpick the terminal-speed string. */
4695 /* XXX perhaps we should allow no speeds to be sent. */
4696 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4697 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4698 /* Send the pty request. */
4699 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4700 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4701 ssh_pkt_adduint32(pkt, ssh->term_height);
4702 ssh_pkt_adduint32(pkt, ssh->term_width);
4703 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4704 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4705 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4706 ssh1_send_ttymode, (void *)pkt);
4707 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4708 ssh_pkt_adduint32(pkt, ssh->ispeed);
4709 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4710 ssh_pkt_adduint32(pkt, ssh->ospeed);
4711 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4712 s_wrpkt(ssh, pkt);
4713 ssh->state = SSH_STATE_INTERMED;
4714 do {
4715 crReturnV;
4716 } while (!pktin);
4717 if (pktin->type != SSH1_SMSG_SUCCESS
4718 && pktin->type != SSH1_SMSG_FAILURE) {
4719 bombout(("Protocol confusion"));
4720 crStopV;
4721 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4722 c_write_str(ssh, "Server refused to allocate pty\r\n");
4723 ssh->editing = ssh->echoing = 1;
4724 }
4725 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4726 ssh->ospeed, ssh->ispeed);
4727 } else {
4728 ssh->editing = ssh->echoing = 1;
4729 }
4730
4731 if (ssh->cfg.compression) {
4732 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4733 do {
4734 crReturnV;
4735 } while (!pktin);
4736 if (pktin->type != SSH1_SMSG_SUCCESS
4737 && pktin->type != SSH1_SMSG_FAILURE) {
4738 bombout(("Protocol confusion"));
4739 crStopV;
4740 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4741 c_write_str(ssh, "Server refused to compress\r\n");
4742 }
4743 logevent("Started compression");
4744 ssh->v1_compressing = TRUE;
4745 ssh->cs_comp_ctx = zlib_compress_init();
4746 logevent("Initialised zlib (RFC1950) compression");
4747 ssh->sc_comp_ctx = zlib_decompress_init();
4748 logevent("Initialised zlib (RFC1950) decompression");
4749 }
4750
4751 /*
4752 * Start the shell or command.
4753 *
4754 * Special case: if the first-choice command is an SSH-2
4755 * subsystem (hence not usable here) and the second choice
4756 * exists, we fall straight back to that.
4757 */
4758 {
4759 char *cmd = ssh->cfg.remote_cmd_ptr;
4760
4761 if (!cmd) cmd = ssh->cfg.remote_cmd;
4762
4763 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4764 cmd = ssh->cfg.remote_cmd_ptr2;
4765 ssh->fallback_cmd = TRUE;
4766 }
4767 if (*cmd)
4768 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4769 else
4770 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4771 logevent("Started session");
4772 }
4773
4774 ssh->state = SSH_STATE_SESSION;
4775 if (ssh->size_needed)
4776 ssh_size(ssh, ssh->term_width, ssh->term_height);
4777 if (ssh->eof_needed)
4778 ssh_special(ssh, TS_EOF);
4779
4780 if (ssh->ldisc)
4781 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4782 ssh->send_ok = 1;
4783 ssh->channels = newtree234(ssh_channelcmp);
4784 while (1) {
4785
4786 /*
4787 * By this point, most incoming packets are already being
4788 * handled by the dispatch table, and we need only pay
4789 * attention to the unusual ones.
4790 */
4791
4792 crReturnV;
4793 if (pktin) {
4794 if (pktin->type == SSH1_SMSG_SUCCESS) {
4795 /* may be from EXEC_SHELL on some servers */
4796 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4797 /* may be from EXEC_SHELL on some servers
4798 * if no pty is available or in other odd cases. Ignore */
4799 } else {
4800 bombout(("Strange packet received: type %d", pktin->type));
4801 crStopV;
4802 }
4803 } else {
4804 while (inlen > 0) {
4805 int len = min(inlen, 512);
4806 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4807 PKT_INT, len, PKT_DATA, in, len,
4808 PKTT_OTHER, PKT_END);
4809 in += len;
4810 inlen -= len;
4811 }
4812 }
4813 }
4814
4815 crFinishV;
4816 }
4817
4818 /*
4819 * Handle the top-level SSH-2 protocol.
4820 */
4821 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4822 {
4823 char *msg;
4824 int msglen;
4825
4826 ssh_pkt_getstring(pktin, &msg, &msglen);
4827 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4828 }
4829
4830 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4831 {
4832 /* log reason code in disconnect message */
4833 char *msg;
4834 int msglen;
4835
4836 ssh_pkt_getstring(pktin, &msg, &msglen);
4837 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4838 }
4839
4840 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4841 {
4842 /* Do nothing, because we're ignoring it! Duhh. */
4843 }
4844
4845 static void ssh1_protocol_setup(Ssh ssh)
4846 {
4847 int i;
4848
4849 /*
4850 * Most messages are handled by the coroutines.
4851 */
4852 for (i = 0; i < 256; i++)
4853 ssh->packet_dispatch[i] = NULL;
4854
4855 /*
4856 * These special message types we install handlers for.
4857 */
4858 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4859 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4860 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4861 }
4862
4863 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4864 struct Packet *pktin)
4865 {
4866 unsigned char *in=(unsigned char*)vin;
4867 if (ssh->state == SSH_STATE_CLOSED)
4868 return;
4869
4870 if (pktin && ssh->packet_dispatch[pktin->type]) {
4871 ssh->packet_dispatch[pktin->type](ssh, pktin);
4872 return;
4873 }
4874
4875 if (!ssh->protocol_initial_phase_done) {
4876 if (do_ssh1_login(ssh, in, inlen, pktin))
4877 ssh->protocol_initial_phase_done = TRUE;
4878 else
4879 return;
4880 }
4881
4882 do_ssh1_connection(ssh, in, inlen, pktin);
4883 }
4884
4885 /*
4886 * Utility routine for decoding comma-separated strings in KEXINIT.
4887 */
4888 static int in_commasep_string(char *needle, char *haystack, int haylen)
4889 {
4890 int needlen;
4891 if (!needle || !haystack) /* protect against null pointers */
4892 return 0;
4893 needlen = strlen(needle);
4894 while (1) {
4895 /*
4896 * Is it at the start of the string?
4897 */
4898 if (haylen >= needlen && /* haystack is long enough */
4899 !memcmp(needle, haystack, needlen) && /* initial match */
4900 (haylen == needlen || haystack[needlen] == ',')
4901 /* either , or EOS follows */
4902 )
4903 return 1;
4904 /*
4905 * If not, search for the next comma and resume after that.
4906 * If no comma found, terminate.
4907 */
4908 while (haylen > 0 && *haystack != ',')
4909 haylen--, haystack++;
4910 if (haylen == 0)
4911 return 0;
4912 haylen--, haystack++; /* skip over comma itself */
4913 }
4914 }
4915
4916 /*
4917 * Similar routine for checking whether we have the first string in a list.
4918 */
4919 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4920 {
4921 int needlen;
4922 if (!needle || !haystack) /* protect against null pointers */
4923 return 0;
4924 needlen = strlen(needle);
4925 /*
4926 * Is it at the start of the string?
4927 */
4928 if (haylen >= needlen && /* haystack is long enough */
4929 !memcmp(needle, haystack, needlen) && /* initial match */
4930 (haylen == needlen || haystack[needlen] == ',')
4931 /* either , or EOS follows */
4932 )
4933 return 1;
4934 return 0;
4935 }
4936
4937
4938 /*
4939 * SSH-2 key creation method.
4940 */
4941 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4942 unsigned char *sessid, char chr,
4943 unsigned char *keyspace)
4944 {
4945 SHA_State s;
4946 /* First 20 bytes. */
4947 SHA_Init(&s);
4948 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4949 sha_mpint(&s, K);
4950 SHA_Bytes(&s, H, 20);
4951 SHA_Bytes(&s, &chr, 1);
4952 SHA_Bytes(&s, sessid, 20);
4953 SHA_Final(&s, keyspace);
4954 /* Next 20 bytes. */
4955 SHA_Init(&s);
4956 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4957 sha_mpint(&s, K);
4958 SHA_Bytes(&s, H, 20);
4959 SHA_Bytes(&s, keyspace, 20);
4960 SHA_Final(&s, keyspace + 20);
4961 }
4962
4963 /*
4964 * Handle the SSH-2 transport layer.
4965 */
4966 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4967 struct Packet *pktin)
4968 {
4969 unsigned char *in = (unsigned char *)vin;
4970 struct do_ssh2_transport_state {
4971 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4972 Bignum p, g, e, f, K;
4973 int kex_init_value, kex_reply_value;
4974 const struct ssh_mac **maclist;
4975 int nmacs;
4976 const struct ssh2_cipher *cscipher_tobe;
4977 const struct ssh2_cipher *sccipher_tobe;
4978 const struct ssh_mac *csmac_tobe;
4979 const struct ssh_mac *scmac_tobe;
4980 const struct ssh_compress *cscomp_tobe;
4981 const struct ssh_compress *sccomp_tobe;
4982 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4983 int hostkeylen, siglen;
4984 void *hkey; /* actual host key */
4985 unsigned char exchange_hash[20];
4986 int n_preferred_kex;
4987 const struct ssh_kex *preferred_kex[KEX_MAX];
4988 int n_preferred_ciphers;
4989 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4990 const struct ssh_compress *preferred_comp;
4991 int got_session_id, activated_authconn;
4992 struct Packet *pktout;
4993 int dlgret;
4994 int guessok;
4995 int ignorepkt;
4996 };
4997 crState(do_ssh2_transport_state);
4998
4999 crBegin(ssh->do_ssh2_transport_crstate);
5000
5001 s->cscipher_tobe = s->sccipher_tobe = NULL;
5002 s->csmac_tobe = s->scmac_tobe = NULL;
5003 s->cscomp_tobe = s->sccomp_tobe = NULL;
5004
5005 s->got_session_id = s->activated_authconn = FALSE;
5006
5007 /*
5008 * Be prepared to work around the buggy MAC problem.
5009 */
5010 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5011 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5012 else
5013 s->maclist = macs, s->nmacs = lenof(macs);
5014
5015 begin_key_exchange:
5016 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
5017 {
5018 int i, j, commalist_started;
5019
5020 /*
5021 * Set up the preferred key exchange. (NULL => warn below here)
5022 */
5023 s->n_preferred_kex = 0;
5024 for (i = 0; i < KEX_MAX; i++) {
5025 switch (ssh->cfg.ssh_kexlist[i]) {
5026 case KEX_DHGEX:
5027 s->preferred_kex[s->n_preferred_kex++] =
5028 &ssh_diffiehellman_gex;
5029 break;
5030 case KEX_DHGROUP14:
5031 s->preferred_kex[s->n_preferred_kex++] =
5032 &ssh_diffiehellman_group14;
5033 break;
5034 case KEX_DHGROUP1:
5035 s->preferred_kex[s->n_preferred_kex++] =
5036 &ssh_diffiehellman_group1;
5037 break;
5038 case CIPHER_WARN:
5039 /* Flag for later. Don't bother if it's the last in
5040 * the list. */
5041 if (i < KEX_MAX - 1) {
5042 s->preferred_kex[s->n_preferred_kex++] = NULL;
5043 }
5044 break;
5045 }
5046 }
5047
5048 /*
5049 * Set up the preferred ciphers. (NULL => warn below here)
5050 */
5051 s->n_preferred_ciphers = 0;
5052 for (i = 0; i < CIPHER_MAX; i++) {
5053 switch (ssh->cfg.ssh_cipherlist[i]) {
5054 case CIPHER_BLOWFISH:
5055 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5056 break;
5057 case CIPHER_DES:
5058 if (ssh->cfg.ssh2_des_cbc) {
5059 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5060 }
5061 break;
5062 case CIPHER_3DES:
5063 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5064 break;
5065 case CIPHER_AES:
5066 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5067 break;
5068 case CIPHER_ARCFOUR:
5069 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5070 break;
5071 case CIPHER_WARN:
5072 /* Flag for later. Don't bother if it's the last in
5073 * the list. */
5074 if (i < CIPHER_MAX - 1) {
5075 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5076 }
5077 break;
5078 }
5079 }
5080
5081 /*
5082 * Set up preferred compression.
5083 */
5084 if (ssh->cfg.compression)
5085 s->preferred_comp = &ssh_zlib;
5086 else
5087 s->preferred_comp = &ssh_comp_none;
5088
5089 /*
5090 * Enable queueing of outgoing auth- or connection-layer
5091 * packets while we are in the middle of a key exchange.
5092 */
5093 ssh->queueing = TRUE;
5094
5095 /*
5096 * Flag that KEX is in progress.
5097 */
5098 ssh->kex_in_progress = TRUE;
5099
5100 /*
5101 * Construct and send our key exchange packet.
5102 */
5103 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5104 for (i = 0; i < 16; i++)
5105 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5106 /* List key exchange algorithms. */
5107 ssh2_pkt_addstring_start(s->pktout);
5108 commalist_started = 0;
5109 for (i = 0; i < s->n_preferred_kex; i++) {
5110 const struct ssh_kex *k = s->preferred_kex[i];
5111 if (!k) continue; /* warning flag */
5112 if (commalist_started)
5113 ssh2_pkt_addstring_str(s->pktout, ",");
5114 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
5115 commalist_started = 1;
5116 }
5117 /* List server host key algorithms. */
5118 ssh2_pkt_addstring_start(s->pktout);
5119 for (i = 0; i < lenof(hostkey_algs); i++) {
5120 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5121 if (i < lenof(hostkey_algs) - 1)
5122 ssh2_pkt_addstring_str(s->pktout, ",");
5123 }
5124 /* List client->server encryption algorithms. */
5125 ssh2_pkt_addstring_start(s->pktout);
5126 commalist_started = 0;
5127 for (i = 0; i < s->n_preferred_ciphers; i++) {
5128 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5129 if (!c) continue; /* warning flag */
5130 for (j = 0; j < c->nciphers; j++) {
5131 if (commalist_started)
5132 ssh2_pkt_addstring_str(s->pktout, ",");
5133 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5134 commalist_started = 1;
5135 }
5136 }
5137 /* List server->client encryption algorithms. */
5138 ssh2_pkt_addstring_start(s->pktout);
5139 commalist_started = 0;
5140 for (i = 0; i < s->n_preferred_ciphers; i++) {
5141 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5142 if (!c) continue; /* warning flag */
5143 for (j = 0; j < c->nciphers; j++) {
5144 if (commalist_started)
5145 ssh2_pkt_addstring_str(s->pktout, ",");
5146 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5147 commalist_started = 1;
5148 }
5149 }
5150 /* List client->server MAC algorithms. */
5151 ssh2_pkt_addstring_start(s->pktout);
5152 for (i = 0; i < s->nmacs; i++) {
5153 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5154 if (i < s->nmacs - 1)
5155 ssh2_pkt_addstring_str(s->pktout, ",");
5156 }
5157 /* List server->client MAC algorithms. */
5158 ssh2_pkt_addstring_start(s->pktout);
5159 for (i = 0; i < s->nmacs; i++) {
5160 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5161 if (i < s->nmacs - 1)
5162 ssh2_pkt_addstring_str(s->pktout, ",");
5163 }
5164 /* List client->server compression algorithms. */
5165 ssh2_pkt_addstring_start(s->pktout);
5166 assert(lenof(compressions) > 1);
5167 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5168 for (i = 0; i < lenof(compressions); i++) {
5169 const struct ssh_compress *c = compressions[i];
5170 if (c != s->preferred_comp) {
5171 ssh2_pkt_addstring_str(s->pktout, ",");
5172 ssh2_pkt_addstring_str(s->pktout, c->name);
5173 }
5174 }
5175 /* List server->client compression algorithms. */
5176 ssh2_pkt_addstring_start(s->pktout);
5177 assert(lenof(compressions) > 1);
5178 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5179 for (i = 0; i < lenof(compressions); i++) {
5180 const struct ssh_compress *c = compressions[i];
5181 if (c != s->preferred_comp) {
5182 ssh2_pkt_addstring_str(s->pktout, ",");
5183 ssh2_pkt_addstring_str(s->pktout, c->name);
5184 }
5185 }
5186 /* List client->server languages. Empty list. */
5187 ssh2_pkt_addstring_start(s->pktout);
5188 /* List server->client languages. Empty list. */
5189 ssh2_pkt_addstring_start(s->pktout);
5190 /* First KEX packet does _not_ follow, because we're not that brave. */
5191 ssh2_pkt_addbool(s->pktout, FALSE);
5192 /* Reserved. */
5193 ssh2_pkt_adduint32(s->pktout, 0);
5194 }
5195
5196 ssh->exhash = ssh->exhashbase;
5197 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
5198
5199 ssh2_pkt_send_noqueue(ssh, s->pktout);
5200
5201 if (!pktin)
5202 crWaitUntil(pktin);
5203 if (pktin->length > 5)
5204 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
5205
5206 /*
5207 * Now examine the other side's KEXINIT to see what we're up
5208 * to.
5209 */
5210 {
5211 char *str, *preferred;
5212 int i, j, len;
5213
5214 if (pktin->type != SSH2_MSG_KEXINIT) {
5215 bombout(("expected key exchange packet from server"));
5216 crStop(0);
5217 }
5218 ssh->kex = NULL;
5219 ssh->hostkey = NULL;
5220 s->cscipher_tobe = NULL;
5221 s->sccipher_tobe = NULL;
5222 s->csmac_tobe = NULL;
5223 s->scmac_tobe = NULL;
5224 s->cscomp_tobe = NULL;
5225 s->sccomp_tobe = NULL;
5226 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5227
5228 pktin->savedpos += 16; /* skip garbage cookie */
5229 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5230
5231 preferred = NULL;
5232 for (i = 0; i < s->n_preferred_kex; i++) {
5233 const struct ssh_kex *k = s->preferred_kex[i];
5234 if (!k) {
5235 s->warn_kex = TRUE;
5236 } else {
5237 if (!preferred) preferred = k->name;
5238 if (in_commasep_string(k->name, str, len))
5239 ssh->kex = k;
5240 }
5241 if (ssh->kex)
5242 break;
5243 }
5244 if (!ssh->kex) {
5245 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5246 str ? str : "(null)"));
5247 crStop(0);
5248 }
5249 /*
5250 * Note that the server's guess is considered wrong if it doesn't match
5251 * the first algorithm in our list, even if it's still the algorithm
5252 * we end up using.
5253 */
5254 s->guessok = first_in_commasep_string(preferred, str, len);
5255 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5256 for (i = 0; i < lenof(hostkey_algs); i++) {
5257 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5258 ssh->hostkey = hostkey_algs[i];
5259 break;
5260 }
5261 }
5262 s->guessok = s->guessok &&
5263 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5264 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5265 for (i = 0; i < s->n_preferred_ciphers; i++) {
5266 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5267 if (!c) {
5268 s->warn_cscipher = TRUE;
5269 } else {
5270 for (j = 0; j < c->nciphers; j++) {
5271 if (in_commasep_string(c->list[j]->name, str, len)) {
5272 s->cscipher_tobe = c->list[j];
5273 break;
5274 }
5275 }
5276 }
5277 if (s->cscipher_tobe)
5278 break;
5279 }
5280 if (!s->cscipher_tobe) {
5281 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5282 str ? str : "(null)"));
5283 crStop(0);
5284 }
5285
5286 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5287 for (i = 0; i < s->n_preferred_ciphers; i++) {
5288 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5289 if (!c) {
5290 s->warn_sccipher = TRUE;
5291 } else {
5292 for (j = 0; j < c->nciphers; j++) {
5293 if (in_commasep_string(c->list[j]->name, str, len)) {
5294 s->sccipher_tobe = c->list[j];
5295 break;
5296 }
5297 }
5298 }
5299 if (s->sccipher_tobe)
5300 break;
5301 }
5302 if (!s->sccipher_tobe) {
5303 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5304 str ? str : "(null)"));
5305 crStop(0);
5306 }
5307
5308 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5309 for (i = 0; i < s->nmacs; i++) {
5310 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5311 s->csmac_tobe = s->maclist[i];
5312 break;
5313 }
5314 }
5315 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5316 for (i = 0; i < s->nmacs; i++) {
5317 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5318 s->scmac_tobe = s->maclist[i];
5319 break;
5320 }
5321 }
5322 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5323 for (i = 0; i < lenof(compressions) + 1; i++) {
5324 const struct ssh_compress *c =
5325 i == 0 ? s->preferred_comp : compressions[i - 1];
5326 if (in_commasep_string(c->name, str, len)) {
5327 s->cscomp_tobe = c;
5328 break;
5329 }
5330 }
5331 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5332 for (i = 0; i < lenof(compressions) + 1; i++) {
5333 const struct ssh_compress *c =
5334 i == 0 ? s->preferred_comp : compressions[i - 1];
5335 if (in_commasep_string(c->name, str, len)) {
5336 s->sccomp_tobe = c;
5337 break;
5338 }
5339 }
5340 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5341 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5342 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5343
5344 if (s->warn_kex) {
5345 ssh_set_frozen(ssh, 1);
5346 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5347 ssh->kex->name,
5348 ssh_dialog_callback, ssh);
5349 if (s->dlgret < 0) {
5350 do {
5351 crReturn(0);
5352 if (pktin) {
5353 bombout(("Unexpected data from server while"
5354 " waiting for user response"));
5355 crStop(0);
5356 }
5357 } while (pktin || inlen > 0);
5358 s->dlgret = ssh->user_response;
5359 }
5360 ssh_set_frozen(ssh, 0);
5361 if (s->dlgret == 0) {
5362 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5363 0, TRUE);
5364 crStop(0);
5365 }
5366 }
5367
5368 if (s->warn_cscipher) {
5369 ssh_set_frozen(ssh, 1);
5370 s->dlgret = askalg(ssh->frontend,
5371 "client-to-server cipher",
5372 s->cscipher_tobe->name,
5373 ssh_dialog_callback, ssh);
5374 if (s->dlgret < 0) {
5375 do {
5376 crReturn(0);
5377 if (pktin) {
5378 bombout(("Unexpected data from server while"
5379 " waiting for user response"));
5380 crStop(0);
5381 }
5382 } while (pktin || inlen > 0);
5383 s->dlgret = ssh->user_response;
5384 }
5385 ssh_set_frozen(ssh, 0);
5386 if (s->dlgret == 0) {
5387 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5388 0, TRUE);
5389 crStop(0);
5390 }
5391 }
5392
5393 if (s->warn_sccipher) {
5394 ssh_set_frozen(ssh, 1);
5395 s->dlgret = askalg(ssh->frontend,
5396 "server-to-client cipher",
5397 s->sccipher_tobe->name,
5398 ssh_dialog_callback, ssh);
5399 if (s->dlgret < 0) {
5400 do {
5401 crReturn(0);
5402 if (pktin) {
5403 bombout(("Unexpected data from server while"
5404 " waiting for user response"));
5405 crStop(0);
5406 }
5407 } while (pktin || inlen > 0);
5408 s->dlgret = ssh->user_response;
5409 }
5410 ssh_set_frozen(ssh, 0);
5411 if (s->dlgret == 0) {
5412 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5413 0, TRUE);
5414 crStop(0);
5415 }
5416 }
5417
5418 if (s->ignorepkt) /* first_kex_packet_follows */
5419 crWaitUntil(pktin); /* Ignore packet */
5420 }
5421
5422 /*
5423 * Work out the number of bits of key we will need from the key
5424 * exchange. We start with the maximum key length of either
5425 * cipher...
5426 */
5427 {
5428 int csbits, scbits;
5429
5430 csbits = s->cscipher_tobe->keylen;
5431 scbits = s->sccipher_tobe->keylen;
5432 s->nbits = (csbits > scbits ? csbits : scbits);
5433 }
5434 /* The keys only have 160-bit entropy, since they're based on
5435 * a SHA-1 hash. So cap the key size at 160 bits. */
5436 if (s->nbits > 160)
5437 s->nbits = 160;
5438
5439 /*
5440 * If we're doing Diffie-Hellman group exchange, start by
5441 * requesting a group.
5442 */
5443 if (!ssh->kex->pdata) {
5444 logevent("Doing Diffie-Hellman group exchange");
5445 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5446 /*
5447 * Work out how big a DH group we will need to allow that
5448 * much data.
5449 */
5450 s->pbits = 512 << ((s->nbits - 1) / 64);
5451 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5452 ssh2_pkt_adduint32(s->pktout, s->pbits);
5453 ssh2_pkt_send_noqueue(ssh, s->pktout);
5454
5455 crWaitUntil(pktin);
5456 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5457 bombout(("expected key exchange group packet from server"));
5458 crStop(0);
5459 }
5460 s->p = ssh2_pkt_getmp(pktin);
5461 s->g = ssh2_pkt_getmp(pktin);
5462 if (!s->p || !s->g) {
5463 bombout(("unable to read mp-ints from incoming group packet"));
5464 crStop(0);
5465 }
5466 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5467 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5468 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5469 } else {
5470 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5471 ssh->kex_ctx = dh_setup_group(ssh->kex);
5472 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5473 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5474 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5475 ssh->kex->groupname);
5476 }
5477
5478 logevent("Doing Diffie-Hellman key exchange");
5479 /*
5480 * Now generate and send e for Diffie-Hellman.
5481 */
5482 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5483 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5484 s->pktout = ssh2_pkt_init(s->kex_init_value);
5485 ssh2_pkt_addmp(s->pktout, s->e);
5486 ssh2_pkt_send_noqueue(ssh, s->pktout);
5487
5488 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5489 crWaitUntil(pktin);
5490 if (pktin->type != s->kex_reply_value) {
5491 bombout(("expected key exchange reply packet from server"));
5492 crStop(0);
5493 }
5494 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5495 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5496 s->f = ssh2_pkt_getmp(pktin);
5497 if (!s->f) {
5498 bombout(("unable to parse key exchange reply packet"));
5499 crStop(0);
5500 }
5501 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5502
5503 s->K = dh_find_K(ssh->kex_ctx, s->f);
5504
5505 /* We assume everything from now on will be quick, and it might
5506 * involve user interaction. */
5507 set_busy_status(ssh->frontend, BUSY_NOT);
5508
5509 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5510 if (ssh->kex == &ssh_diffiehellman_gex) {
5511 sha_uint32(&ssh->exhash, s->pbits);
5512 sha_mpint(&ssh->exhash, s->p);
5513 sha_mpint(&ssh->exhash, s->g);
5514 }
5515 sha_mpint(&ssh->exhash, s->e);
5516 sha_mpint(&ssh->exhash, s->f);
5517 sha_mpint(&ssh->exhash, s->K);
5518 SHA_Final(&ssh->exhash, s->exchange_hash);
5519
5520 dh_cleanup(ssh->kex_ctx);
5521 ssh->kex_ctx = NULL;
5522
5523 #if 0
5524 debug(("Exchange hash is:\n"));
5525 dmemdump(s->exchange_hash, 20);
5526 #endif
5527
5528 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5529 if (!s->hkey ||
5530 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5531 (char *)s->exchange_hash, 20)) {
5532 bombout(("Server's host key did not match the signature supplied"));
5533 crStop(0);
5534 }
5535
5536 /*
5537 * Authenticate remote host: verify host key. (We've already
5538 * checked the signature of the exchange hash.)
5539 */
5540 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5541 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5542 ssh_set_frozen(ssh, 1);
5543 s->dlgret = verify_ssh_host_key(ssh->frontend,
5544 ssh->savedhost, ssh->savedport,
5545 ssh->hostkey->keytype, s->keystr,
5546 s->fingerprint,
5547 ssh_dialog_callback, ssh);
5548 if (s->dlgret < 0) {
5549 do {
5550 crReturn(0);
5551 if (pktin) {
5552 bombout(("Unexpected data from server while waiting"
5553 " for user host key response"));
5554 crStop(0);
5555 }
5556 } while (pktin || inlen > 0);
5557 s->dlgret = ssh->user_response;
5558 }
5559 ssh_set_frozen(ssh, 0);
5560 if (s->dlgret == 0) {
5561 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5562 0, TRUE);
5563 crStop(0);
5564 }
5565 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5566 logevent("Host key fingerprint is:");
5567 logevent(s->fingerprint);
5568 }
5569 sfree(s->fingerprint);
5570 sfree(s->keystr);
5571 ssh->hostkey->freekey(s->hkey);
5572
5573 /*
5574 * The exchange hash from the very first key exchange is also
5575 * the session id, used in session key construction and
5576 * authentication.
5577 */
5578 if (!s->got_session_id) {
5579 memcpy(ssh->v2_session_id, s->exchange_hash,
5580 sizeof(s->exchange_hash));
5581 s->got_session_id = TRUE;
5582 }
5583
5584 /*
5585 * Send SSH2_MSG_NEWKEYS.
5586 */
5587 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5588 ssh2_pkt_send_noqueue(ssh, s->pktout);
5589 ssh->outgoing_data_size = 0; /* start counting from here */
5590
5591 /*
5592 * We've sent client NEWKEYS, so create and initialise
5593 * client-to-server session keys.
5594 */
5595 if (ssh->cs_cipher_ctx)
5596 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5597 ssh->cscipher = s->cscipher_tobe;
5598 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5599
5600 if (ssh->cs_mac_ctx)
5601 ssh->csmac->free_context(ssh->cs_mac_ctx);
5602 ssh->csmac = s->csmac_tobe;
5603 ssh->cs_mac_ctx = ssh->csmac->make_context();
5604
5605 if (ssh->cs_comp_ctx)
5606 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5607 ssh->cscomp = s->cscomp_tobe;
5608 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5609
5610 /*
5611 * Set IVs on client-to-server keys. Here we use the exchange
5612 * hash from the _first_ key exchange.
5613 */
5614 {
5615 unsigned char keyspace[40];
5616 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5617 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5618 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5619 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5620 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5621 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5622 }
5623
5624 logeventf(ssh, "Initialised %.200s client->server encryption",
5625 ssh->cscipher->text_name);
5626 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5627 ssh->csmac->text_name);
5628 if (ssh->cscomp->text_name)
5629 logeventf(ssh, "Initialised %s compression",
5630 ssh->cscomp->text_name);
5631
5632 /*
5633 * Now our end of the key exchange is complete, we can send all
5634 * our queued higher-layer packets.
5635 */
5636 ssh->queueing = FALSE;
5637 ssh2_pkt_queuesend(ssh);
5638
5639 /*
5640 * Expect SSH2_MSG_NEWKEYS from server.
5641 */
5642 crWaitUntil(pktin);
5643 if (pktin->type != SSH2_MSG_NEWKEYS) {
5644 bombout(("expected new-keys packet from server"));
5645 crStop(0);
5646 }
5647 ssh->incoming_data_size = 0; /* start counting from here */
5648
5649 /*
5650 * We've seen server NEWKEYS, so create and initialise
5651 * server-to-client session keys.
5652 */
5653 if (ssh->sc_cipher_ctx)
5654 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5655 ssh->sccipher = s->sccipher_tobe;
5656 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5657
5658 if (ssh->sc_mac_ctx)
5659 ssh->scmac->free_context(ssh->sc_mac_ctx);
5660 ssh->scmac = s->scmac_tobe;
5661 ssh->sc_mac_ctx = ssh->scmac->make_context();
5662
5663 if (ssh->sc_comp_ctx)
5664 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5665 ssh->sccomp = s->sccomp_tobe;
5666 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5667
5668 /*
5669 * Set IVs on server-to-client keys. Here we use the exchange
5670 * hash from the _first_ key exchange.
5671 */
5672 {
5673 unsigned char keyspace[40];
5674 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5675 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5676 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5677 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5678 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5679 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5680 }
5681 logeventf(ssh, "Initialised %.200s server->client encryption",
5682 ssh->sccipher->text_name);
5683 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5684 ssh->scmac->text_name);
5685 if (ssh->sccomp->text_name)
5686 logeventf(ssh, "Initialised %s decompression",
5687 ssh->sccomp->text_name);
5688
5689 /*
5690 * Free key exchange data.
5691 */
5692 freebn(s->f);
5693 freebn(s->K);
5694 if (ssh->kex == &ssh_diffiehellman_gex) {
5695 freebn(s->g);
5696 freebn(s->p);
5697 }
5698
5699 /*
5700 * Key exchange is over. Loop straight back round if we have a
5701 * deferred rekey reason.
5702 */
5703 if (ssh->deferred_rekey_reason) {
5704 logevent(ssh->deferred_rekey_reason);
5705 pktin = NULL;
5706 ssh->deferred_rekey_reason = NULL;
5707 goto begin_key_exchange;
5708 }
5709
5710 /*
5711 * Otherwise, schedule a timer for our next rekey.
5712 */
5713 ssh->kex_in_progress = FALSE;
5714 ssh->last_rekey = GETTICKCOUNT();
5715 if (ssh->cfg.ssh_rekey_time != 0)
5716 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5717 ssh2_timer, ssh);
5718
5719 /*
5720 * If this is the first key exchange phase, we must pass the
5721 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5722 * wants to see it but because it will need time to initialise
5723 * itself before it sees an actual packet. In subsequent key
5724 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5725 * it would only confuse the layer above.
5726 */
5727 if (s->activated_authconn) {
5728 crReturn(0);
5729 }
5730 s->activated_authconn = TRUE;
5731
5732 /*
5733 * Now we're encrypting. Begin returning 1 to the protocol main
5734 * function so that other things can run on top of the
5735 * transport. If we ever see a KEXINIT, we must go back to the
5736 * start.
5737 *
5738 * We _also_ go back to the start if we see pktin==NULL and
5739 * inlen==-1, because this is a special signal meaning
5740 * `initiate client-driven rekey', and `in' contains a message
5741 * giving the reason for the rekey.
5742 */
5743 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5744 (!pktin && inlen == -1))) {
5745 wait_for_rekey:
5746 crReturn(1);
5747 }
5748 if (pktin) {
5749 logevent("Server initiated key re-exchange");
5750 } else {
5751 /*
5752 * Special case: if the server bug is set that doesn't
5753 * allow rekeying, we give a different log message and
5754 * continue waiting. (If such a server _initiates_ a rekey,
5755 * we process it anyway!)
5756 */
5757 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5758 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5759 (char *)in);
5760 /* Reset the counters, so that at least this message doesn't
5761 * hit the event log _too_ often. */
5762 ssh->outgoing_data_size = 0;
5763 ssh->incoming_data_size = 0;
5764 if (ssh->cfg.ssh_rekey_time != 0) {
5765 ssh->next_rekey =
5766 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5767 ssh2_timer, ssh);
5768 }
5769 goto wait_for_rekey; /* this is utterly horrid */
5770 } else {
5771 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5772 }
5773 }
5774 goto begin_key_exchange;
5775
5776 crFinish(1);
5777 }
5778
5779 /*
5780 * Add data to an SSH-2 channel output buffer.
5781 */
5782 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5783 int len)
5784 {
5785 bufchain_add(&c->v.v2.outbuffer, buf, len);
5786 }
5787
5788 /*
5789 * Attempt to send data on an SSH-2 channel.
5790 */
5791 static int ssh2_try_send(struct ssh_channel *c)
5792 {
5793 Ssh ssh = c->ssh;
5794 struct Packet *pktout;
5795
5796 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5797 int len;
5798 void *data;
5799 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5800 if ((unsigned)len > c->v.v2.remwindow)
5801 len = c->v.v2.remwindow;
5802 if ((unsigned)len > c->v.v2.remmaxpkt)
5803 len = c->v.v2.remmaxpkt;
5804 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5805 ssh2_pkt_adduint32(pktout, c->remoteid);
5806 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5807 ssh2_pkt_addstring_start(pktout);
5808 ssh2_pkt_addstring_data(pktout, data, len);
5809 end_log_omission(ssh, pktout);
5810 ssh2_pkt_send(ssh, pktout);
5811 bufchain_consume(&c->v.v2.outbuffer, len);
5812 c->v.v2.remwindow -= len;
5813 }
5814
5815 /*
5816 * After having sent as much data as we can, return the amount
5817 * still buffered.
5818 */
5819 return bufchain_size(&c->v.v2.outbuffer);
5820 }
5821
5822 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5823 {
5824 int bufsize;
5825 if (c->closes)
5826 return; /* don't send on closing channels */
5827 bufsize = ssh2_try_send(c);
5828 if (bufsize == 0) {
5829 switch (c->type) {
5830 case CHAN_MAINSESSION:
5831 /* stdin need not receive an unthrottle
5832 * notification since it will be polled */
5833 break;
5834 case CHAN_X11:
5835 x11_unthrottle(c->u.x11.s);
5836 break;
5837 case CHAN_AGENT:
5838 /* agent sockets are request/response and need no
5839 * buffer management */
5840 break;
5841 case CHAN_SOCKDATA:
5842 pfd_unthrottle(c->u.pfd.s);
5843 break;
5844 }
5845 }
5846 }
5847
5848 /*
5849 * Potentially enlarge the window on an SSH-2 channel.
5850 */
5851 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5852 {
5853 Ssh ssh = c->ssh;
5854
5855 /*
5856 * Never send WINDOW_ADJUST for a channel that the remote side
5857 * already thinks it's closed; there's no point, since it won't
5858 * be sending any more data anyway.
5859 */
5860 if (c->closes != 0)
5861 return;
5862
5863 /*
5864 * Only send a WINDOW_ADJUST if there's significantly more window
5865 * available than the other end thinks there is. This saves us
5866 * sending a WINDOW_ADJUST for every character in a shell session.
5867 *
5868 * "Significant" is arbitrarily defined as half the window size.
5869 */
5870 if (newwin > c->v.v2.locwindow * 2) {
5871 struct Packet *pktout;
5872
5873 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5874 ssh2_pkt_adduint32(pktout, c->remoteid);
5875 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5876 ssh2_pkt_send(ssh, pktout);
5877 c->v.v2.locwindow = newwin;
5878 }
5879 }
5880
5881 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5882 {
5883 unsigned i = ssh_pkt_getuint32(pktin);
5884 struct ssh_channel *c;
5885 c = find234(ssh->channels, &i, ssh_channelfind);
5886 if (c && !c->closes) {
5887 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5888 ssh2_try_send_and_unthrottle(c);
5889 }
5890 }
5891
5892 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5893 {
5894 char *data;
5895 int length;
5896 unsigned i = ssh_pkt_getuint32(pktin);
5897 struct ssh_channel *c;
5898 c = find234(ssh->channels, &i, ssh_channelfind);
5899 if (!c)
5900 return; /* nonexistent channel */
5901 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5902 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5903 return; /* extended but not stderr */
5904 ssh_pkt_getstring(pktin, &data, &length);
5905 if (data) {
5906 int bufsize = 0;
5907 c->v.v2.locwindow -= length;
5908 switch (c->type) {
5909 case CHAN_MAINSESSION:
5910 bufsize =
5911 from_backend(ssh->frontend, pktin->type ==
5912 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5913 data, length);
5914 break;
5915 case CHAN_X11:
5916 bufsize = x11_send(c->u.x11.s, data, length);
5917 break;
5918 case CHAN_SOCKDATA:
5919 bufsize = pfd_send(c->u.pfd.s, data, length);
5920 break;
5921 case CHAN_AGENT:
5922 while (length > 0) {
5923 if (c->u.a.lensofar < 4) {
5924 unsigned int l = min(4 - c->u.a.lensofar, length);
5925 memcpy(c->u.a.msglen + c->u.a.lensofar,
5926 data, l);
5927 data += l;
5928 length -= l;
5929 c->u.a.lensofar += l;
5930 }
5931 if (c->u.a.lensofar == 4) {
5932 c->u.a.totallen =
5933 4 + GET_32BIT(c->u.a.msglen);
5934 c->u.a.message = snewn(c->u.a.totallen,
5935 unsigned char);
5936 memcpy(c->u.a.message, c->u.a.msglen, 4);
5937 }
5938 if (c->u.a.lensofar >= 4 && length > 0) {
5939 unsigned int l =
5940 min(c->u.a.totallen - c->u.a.lensofar,
5941 length);
5942 memcpy(c->u.a.message + c->u.a.lensofar,
5943 data, l);
5944 data += l;
5945 length -= l;
5946 c->u.a.lensofar += l;
5947 }
5948 if (c->u.a.lensofar == c->u.a.totallen) {
5949 void *reply;
5950 int replylen;
5951 if (agent_query(c->u.a.message,
5952 c->u.a.totallen,
5953 &reply, &replylen,
5954 ssh_agentf_callback, c))
5955 ssh_agentf_callback(c, reply, replylen);
5956 sfree(c->u.a.message);
5957 c->u.a.lensofar = 0;
5958 }
5959 }
5960 bufsize = 0;
5961 break;
5962 }
5963 /*
5964 * If we are not buffering too much data,
5965 * enlarge the window again at the remote side.
5966 */
5967 if (bufsize < OUR_V2_WINSIZE)
5968 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5969 }
5970 }
5971
5972 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5973 {
5974 unsigned i = ssh_pkt_getuint32(pktin);
5975 struct ssh_channel *c;
5976
5977 c = find234(ssh->channels, &i, ssh_channelfind);
5978 if (!c)
5979 return; /* nonexistent channel */
5980
5981 if (c->type == CHAN_X11) {
5982 /*
5983 * Remote EOF on an X11 channel means we should
5984 * wrap up and close the channel ourselves.
5985 */
5986 x11_close(c->u.x11.s);
5987 sshfwd_close(c);
5988 } else if (c->type == CHAN_AGENT) {
5989 sshfwd_close(c);
5990 } else if (c->type == CHAN_SOCKDATA) {
5991 pfd_close(c->u.pfd.s);
5992 sshfwd_close(c);
5993 }
5994 }
5995
5996 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5997 {
5998 unsigned i = ssh_pkt_getuint32(pktin);
5999 struct ssh_channel *c;
6000 struct Packet *pktout;
6001
6002 c = find234(ssh->channels, &i, ssh_channelfind);
6003 if (!c || c->halfopen) {
6004 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6005 c ? "half-open" : "nonexistent", i));
6006 return;
6007 }
6008 /* Do pre-close processing on the channel. */
6009 switch (c->type) {
6010 case CHAN_MAINSESSION:
6011 ssh->mainchan = NULL;
6012 update_specials_menu(ssh->frontend);
6013 break;
6014 case CHAN_X11:
6015 if (c->u.x11.s != NULL)
6016 x11_close(c->u.x11.s);
6017 sshfwd_close(c);
6018 break;
6019 case CHAN_AGENT:
6020 sshfwd_close(c);
6021 break;
6022 case CHAN_SOCKDATA:
6023 if (c->u.pfd.s != NULL)
6024 pfd_close(c->u.pfd.s);
6025 sshfwd_close(c);
6026 break;
6027 }
6028 if (c->closes == 0) {
6029 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6030 ssh2_pkt_adduint32(pktout, c->remoteid);
6031 ssh2_pkt_send(ssh, pktout);
6032 }
6033 del234(ssh->channels, c);
6034 bufchain_clear(&c->v.v2.outbuffer);
6035 sfree(c);
6036
6037 /*
6038 * See if that was the last channel left open.
6039 * (This is only our termination condition if we're
6040 * not running in -N mode.)
6041 */
6042 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6043 /*
6044 * We used to send SSH_MSG_DISCONNECT here,
6045 * because I'd believed that _every_ conforming
6046 * SSH-2 connection had to end with a disconnect
6047 * being sent by at least one side; apparently
6048 * I was wrong and it's perfectly OK to
6049 * unceremoniously slam the connection shut
6050 * when you're done, and indeed OpenSSH feels
6051 * this is more polite than sending a
6052 * DISCONNECT. So now we don't.
6053 */
6054 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6055 }
6056 }
6057
6058 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6059 {
6060 unsigned i = ssh_pkt_getuint32(pktin);
6061 struct ssh_channel *c;
6062 struct Packet *pktout;
6063
6064 c = find234(ssh->channels, &i, ssh_channelfind);
6065 if (!c)
6066 return; /* nonexistent channel */
6067 if (c->type != CHAN_SOCKDATA_DORMANT)
6068 return; /* dunno why they're confirming this */
6069 c->remoteid = ssh_pkt_getuint32(pktin);
6070 c->halfopen = FALSE;
6071 c->type = CHAN_SOCKDATA;
6072 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6073 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6074 if (c->u.pfd.s)
6075 pfd_confirm(c->u.pfd.s);
6076 if (c->closes) {
6077 /*
6078 * We have a pending close on this channel,
6079 * which we decided on before the server acked
6080 * the channel open. So now we know the
6081 * remoteid, we can close it again.
6082 */
6083 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6084 ssh2_pkt_adduint32(pktout, c->remoteid);
6085 ssh2_pkt_send(ssh, pktout);
6086 }
6087 }
6088
6089 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6090 {
6091 static const char *const reasons[] = {
6092 "<unknown reason code>",
6093 "Administratively prohibited",
6094 "Connect failed",
6095 "Unknown channel type",
6096 "Resource shortage",
6097 };
6098 unsigned i = ssh_pkt_getuint32(pktin);
6099 unsigned reason_code;
6100 char *reason_string;
6101 int reason_length;
6102 struct ssh_channel *c;
6103 c = find234(ssh->channels, &i, ssh_channelfind);
6104 if (!c)
6105 return; /* nonexistent channel */
6106 if (c->type != CHAN_SOCKDATA_DORMANT)
6107 return; /* dunno why they're failing this */
6108
6109 reason_code = ssh_pkt_getuint32(pktin);
6110 if (reason_code >= lenof(reasons))
6111 reason_code = 0; /* ensure reasons[reason_code] in range */
6112 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6113 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6114 reasons[reason_code], reason_length, reason_string);
6115
6116 pfd_close(c->u.pfd.s);
6117
6118 del234(ssh->channels, c);
6119 sfree(c);
6120 }
6121
6122 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6123 {
6124 unsigned localid;
6125 char *type;
6126 int typelen, want_reply;
6127 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6128 struct ssh_channel *c;
6129 struct Packet *pktout;
6130
6131 localid = ssh_pkt_getuint32(pktin);
6132 ssh_pkt_getstring(pktin, &type, &typelen);
6133 want_reply = ssh2_pkt_getbool(pktin);
6134
6135 /*
6136 * First, check that the channel exists. Otherwise,
6137 * we can instantly disconnect with a rude message.
6138 */
6139 c = find234(ssh->channels, &localid, ssh_channelfind);
6140 if (!c) {
6141 char *buf = dupprintf("Received channel request for nonexistent"
6142 " channel %d", localid);
6143 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6144 sfree(buf);
6145 return;
6146 }
6147
6148 /*
6149 * Having got the channel number, we now look at
6150 * the request type string to see if it's something
6151 * we recognise.
6152 */
6153 if (c == ssh->mainchan) {
6154 /*
6155 * We recognise "exit-status" and "exit-signal" on
6156 * the primary channel.
6157 */
6158 if (typelen == 11 &&
6159 !memcmp(type, "exit-status", 11)) {
6160
6161 ssh->exitcode = ssh_pkt_getuint32(pktin);
6162 logeventf(ssh, "Server sent command exit status %d",
6163 ssh->exitcode);
6164 reply = SSH2_MSG_CHANNEL_SUCCESS;
6165
6166 } else if (typelen == 11 &&
6167 !memcmp(type, "exit-signal", 11)) {
6168
6169 int is_plausible = TRUE, is_int = FALSE;
6170 char *fmt_sig = "", *fmt_msg = "";
6171 char *msg;
6172 int msglen = 0, core = FALSE;
6173 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6174 * provide an `int' for the signal, despite its
6175 * having been a `string' in the drafts since at
6176 * least 2001. (Fixed in session.c 1.147.) Try to
6177 * infer which we can safely parse it as. */
6178 {
6179 unsigned char *p = pktin->body +
6180 pktin->savedpos;
6181 long len = pktin->length - pktin->savedpos;
6182 unsigned long num = GET_32BIT(p); /* what is it? */
6183 /* If it's 0, it hardly matters; assume string */
6184 if (num == 0) {
6185 is_int = FALSE;
6186 } else {
6187 int maybe_int = FALSE, maybe_str = FALSE;
6188 #define CHECK_HYPOTHESIS(offset, result) \
6189 do { \
6190 long q = offset; \
6191 if (q >= 0 && q+4 <= len) { \
6192 q = q + 4 + GET_32BIT(p+q); \
6193 if (q >= 0 && q+4 <= len && \
6194 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6195 result = TRUE; \
6196 } \
6197 } while(0)
6198 CHECK_HYPOTHESIS(4+1, maybe_int);
6199 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6200 #undef CHECK_HYPOTHESIS
6201 if (maybe_int && !maybe_str)
6202 is_int = TRUE;
6203 else if (!maybe_int && maybe_str)
6204 is_int = FALSE;
6205 else
6206 /* Crikey. Either or neither. Panic. */
6207 is_plausible = FALSE;
6208 }
6209 }
6210 if (is_plausible) {
6211 if (is_int) {
6212 /* Old non-standard OpenSSH. */
6213 int signum = ssh_pkt_getuint32(pktin);
6214 fmt_sig = dupprintf(" %d", signum);
6215 } else {
6216 /* As per the drafts. */
6217 char *sig;
6218 int siglen;
6219 ssh_pkt_getstring(pktin, &sig, &siglen);
6220 /* Signal name isn't supposed to be blank, but
6221 * let's cope gracefully if it is. */
6222 if (siglen) {
6223 fmt_sig = dupprintf(" \"%.*s\"",
6224 siglen, sig);
6225 }
6226 }
6227 core = ssh2_pkt_getbool(pktin);
6228 ssh_pkt_getstring(pktin, &msg, &msglen);
6229 if (msglen) {
6230 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6231 }
6232 /* ignore lang tag */
6233 } /* else don't attempt to parse */
6234 logeventf(ssh, "Server exited on signal%s%s%s",
6235 fmt_sig, core ? " (core dumped)" : "",
6236 fmt_msg);
6237 if (*fmt_sig) sfree(fmt_sig);
6238 if (*fmt_msg) sfree(fmt_msg);
6239 reply = SSH2_MSG_CHANNEL_SUCCESS;
6240
6241 }
6242 } else {
6243 /*
6244 * This is a channel request we don't know
6245 * about, so we now either ignore the request
6246 * or respond with CHANNEL_FAILURE, depending
6247 * on want_reply.
6248 */
6249 reply = SSH2_MSG_CHANNEL_FAILURE;
6250 }
6251 if (want_reply) {
6252 pktout = ssh2_pkt_init(reply);
6253 ssh2_pkt_adduint32(pktout, c->remoteid);
6254 ssh2_pkt_send(ssh, pktout);
6255 }
6256 }
6257
6258 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6259 {
6260 char *type;
6261 int typelen, want_reply;
6262 struct Packet *pktout;
6263
6264 ssh_pkt_getstring(pktin, &type, &typelen);
6265 want_reply = ssh2_pkt_getbool(pktin);
6266
6267 /*
6268 * We currently don't support any global requests
6269 * at all, so we either ignore the request or
6270 * respond with REQUEST_FAILURE, depending on
6271 * want_reply.
6272 */
6273 if (want_reply) {
6274 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6275 ssh2_pkt_send(ssh, pktout);
6276 }
6277 }
6278
6279 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6280 {
6281 char *type;
6282 int typelen;
6283 char *peeraddr;
6284 int peeraddrlen;
6285 int peerport;
6286 char *error = NULL;
6287 struct ssh_channel *c;
6288 unsigned remid, winsize, pktsize;
6289 struct Packet *pktout;
6290
6291 ssh_pkt_getstring(pktin, &type, &typelen);
6292 c = snew(struct ssh_channel);
6293 c->ssh = ssh;
6294
6295 remid = ssh_pkt_getuint32(pktin);
6296 winsize = ssh_pkt_getuint32(pktin);
6297 pktsize = ssh_pkt_getuint32(pktin);
6298
6299 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6300 char *addrstr;
6301
6302 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6303 addrstr = snewn(peeraddrlen+1, char);
6304 memcpy(addrstr, peeraddr, peeraddrlen);
6305 addrstr[peeraddrlen] = '\0';
6306 peerport = ssh_pkt_getuint32(pktin);
6307
6308 logeventf(ssh, "Received X11 connect request from %s:%d",
6309 addrstr, peerport);
6310
6311 if (!ssh->X11_fwd_enabled)
6312 error = "X11 forwarding is not enabled";
6313 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6314 ssh->x11auth, addrstr, peerport,
6315 &ssh->cfg) != NULL) {
6316 error = "Unable to open an X11 connection";
6317 } else {
6318 logevent("Opening X11 forward connection succeeded");
6319 c->type = CHAN_X11;
6320 }
6321
6322 sfree(addrstr);
6323 } else if (typelen == 15 &&
6324 !memcmp(type, "forwarded-tcpip", 15)) {
6325 struct ssh_rportfwd pf, *realpf;
6326 char *dummy;
6327 int dummylen;
6328 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6329 pf.sport = ssh_pkt_getuint32(pktin);
6330 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6331 peerport = ssh_pkt_getuint32(pktin);
6332 realpf = find234(ssh->rportfwds, &pf, NULL);
6333 logeventf(ssh, "Received remote port %d open request "
6334 "from %s:%d", pf.sport, peeraddr, peerport);
6335 if (realpf == NULL) {
6336 error = "Remote port is not recognised";
6337 } else {
6338 const char *e = pfd_newconnect(&c->u.pfd.s,
6339 realpf->dhost,
6340 realpf->dport, c,
6341 &ssh->cfg,
6342 realpf->pfrec->addressfamily);
6343 logeventf(ssh, "Attempting to forward remote port to "
6344 "%s:%d", realpf->dhost, realpf->dport);
6345 if (e != NULL) {
6346 logeventf(ssh, "Port open failed: %s", e);
6347 error = "Port open failed";
6348 } else {
6349 logevent("Forwarded port opened successfully");
6350 c->type = CHAN_SOCKDATA;
6351 }
6352 }
6353 } else if (typelen == 22 &&
6354 !memcmp(type, "auth-agent@openssh.com", 22)) {
6355 if (!ssh->agentfwd_enabled)
6356 error = "Agent forwarding is not enabled";
6357 else {
6358 c->type = CHAN_AGENT; /* identify channel type */
6359 c->u.a.lensofar = 0;
6360 }
6361 } else {
6362 error = "Unsupported channel type requested";
6363 }
6364
6365 c->remoteid = remid;
6366 c->halfopen = FALSE;
6367 if (error) {
6368 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6369 ssh2_pkt_adduint32(pktout, c->remoteid);
6370 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6371 ssh2_pkt_addstring(pktout, error);
6372 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6373 ssh2_pkt_send(ssh, pktout);
6374 logeventf(ssh, "Rejected channel open: %s", error);
6375 sfree(c);
6376 } else {
6377 c->localid = alloc_channel_id(ssh);
6378 c->closes = 0;
6379 c->v.v2.locwindow = OUR_V2_WINSIZE;
6380 c->v.v2.remwindow = winsize;
6381 c->v.v2.remmaxpkt = pktsize;
6382 bufchain_init(&c->v.v2.outbuffer);
6383 add234(ssh->channels, c);
6384 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6385 ssh2_pkt_adduint32(pktout, c->remoteid);
6386 ssh2_pkt_adduint32(pktout, c->localid);
6387 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6388 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6389 ssh2_pkt_send(ssh, pktout);
6390 }
6391 }
6392
6393 /*
6394 * Buffer banner messages for later display at some convenient point.
6395 */
6396 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6397 {
6398 /* Arbitrary limit to prevent unbounded inflation of buffer */
6399 if (bufchain_size(&ssh->banner) <= 131072) {
6400 char *banner = NULL;
6401 int size = 0;
6402 ssh_pkt_getstring(pktin, &banner, &size);
6403 if (banner)
6404 bufchain_add(&ssh->banner, banner, size);
6405 }
6406 }
6407
6408 /* Helper function to deal with sending tty modes for "pty-req" */
6409 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6410 {
6411 struct Packet *pktout = (struct Packet *)data;
6412 int i = 0;
6413 unsigned int arg = 0;
6414 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6415 if (i == lenof(ssh_ttymodes)) return;
6416 switch (ssh_ttymodes[i].type) {
6417 case TTY_OP_CHAR:
6418 arg = ssh_tty_parse_specchar(val);
6419 break;
6420 case TTY_OP_BOOL:
6421 arg = ssh_tty_parse_boolean(val);
6422 break;
6423 }
6424 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6425 ssh2_pkt_adduint32(pktout, arg);
6426 }
6427
6428 /*
6429 * Handle the SSH-2 userauth and connection layers.
6430 */
6431 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6432 struct Packet *pktin)
6433 {
6434 struct do_ssh2_authconn_state {
6435 enum {
6436 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6437 AUTH_PASSWORD,
6438 AUTH_KEYBOARD_INTERACTIVE
6439 } method;
6440 enum {
6441 AUTH_TYPE_NONE,
6442 AUTH_TYPE_PUBLICKEY,
6443 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6444 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6445 AUTH_TYPE_PASSWORD,
6446 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6447 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6448 } type;
6449 int done_service_req;
6450 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6451 int tried_pubkey_config, tried_agent;
6452 int kbd_inter_running, kbd_inter_refused;
6453 int we_are_in;
6454 int num_prompts, curr_prompt, echo;
6455 char username[100];
6456 int got_username;
6457 char pwprompt[512];
6458 char password[100];
6459 void *publickey_blob;
6460 int publickey_bloblen;
6461 unsigned char request[5], *response, *p;
6462 int responselen;
6463 int keyi, nkeys;
6464 int authed;
6465 char *pkblob, *alg, *commentp;
6466 int pklen, alglen, commentlen;
6467 int siglen, retlen, len;
6468 char *q, *agentreq, *ret;
6469 int try_send;
6470 int num_env, env_left, env_ok;
6471 struct Packet *pktout;
6472 };
6473 crState(do_ssh2_authconn_state);
6474
6475 crBegin(ssh->do_ssh2_authconn_crstate);
6476
6477 s->done_service_req = FALSE;
6478 s->we_are_in = FALSE;
6479 if (!ssh->cfg.ssh_no_userauth) {
6480 /*
6481 * Request userauth protocol, and await a response to it.
6482 */
6483 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6484 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6485 ssh2_pkt_send(ssh, s->pktout);
6486 crWaitUntilV(pktin);
6487 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6488 s->done_service_req = TRUE;
6489 }
6490 if (!s->done_service_req) {
6491 /*
6492 * Request connection protocol directly, without authentication.
6493 */
6494 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6495 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6496 ssh2_pkt_send(ssh, s->pktout);
6497 crWaitUntilV(pktin);
6498 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6499 s->we_are_in = TRUE; /* no auth required */
6500 } else {
6501 bombout(("Server refused service request"));
6502 crStopV;
6503 }
6504 }
6505
6506 /*
6507 * We repeat this whole loop, including the username prompt,
6508 * until we manage a successful authentication. If the user
6509 * types the wrong _password_, they can be sent back to the
6510 * beginning to try another username, if this is configured on.
6511 * (If they specify a username in the config, they are never
6512 * asked, even if they do give a wrong password.)
6513 *
6514 * I think this best serves the needs of
6515 *
6516 * - the people who have no configuration, no keys, and just
6517 * want to try repeated (username,password) pairs until they
6518 * type both correctly
6519 *
6520 * - people who have keys and configuration but occasionally
6521 * need to fall back to passwords
6522 *
6523 * - people with a key held in Pageant, who might not have
6524 * logged in to a particular machine before; so they want to
6525 * type a username, and then _either_ their key will be
6526 * accepted, _or_ they will type a password. If they mistype
6527 * the username they will want to be able to get back and
6528 * retype it!
6529 */
6530 s->username[0] = '\0';
6531 s->got_username = FALSE;
6532 bufchain_init(&ssh->banner);
6533 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6534 ssh2_msg_userauth_banner;
6535 while (!s->we_are_in) {
6536 /*
6537 * Get a username.
6538 */
6539 if (s->got_username && !ssh->cfg.change_username) {
6540 /*
6541 * We got a username last time round this loop, and
6542 * with change_username turned off we don't try to get
6543 * it again.
6544 */
6545 } else if (!*ssh->cfg.username) {
6546 if (ssh_get_line && !ssh_getline_pw_only) {
6547 if (!ssh_get_line("login as: ",
6548 s->username, sizeof(s->username), FALSE)) {
6549 /*
6550 * get_line failed to get a username.
6551 * Terminate.
6552 */
6553 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
6554 crStopV;
6555 }
6556 } else {
6557 int ret; /* need not be saved across crReturn */
6558 c_write_str(ssh, "login as: ");
6559 ssh->send_ok = 1;
6560 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6561 do {
6562 crWaitUntilV(!pktin);
6563 ret = process_userpass_input(ssh, in, inlen);
6564 } while (ret == 0);
6565 if (ret < 0)
6566 cleanup_exit(0);
6567 c_write_str(ssh, "\r\n");
6568 }
6569 s->username[strcspn(s->username, "\n\r")] = '\0';
6570 } else {
6571 char *stuff;
6572 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6573 s->username[sizeof(s->username)-1] = '\0';
6574 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6575 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6576 c_write_str(ssh, stuff);
6577 sfree(stuff);
6578 }
6579 }
6580 s->got_username = TRUE;
6581
6582 /*
6583 * Send an authentication request using method "none": (a)
6584 * just in case it succeeds, and (b) so that we know what
6585 * authentication methods we can usefully try next.
6586 */
6587 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6588
6589 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6590 ssh2_pkt_addstring(s->pktout, s->username);
6591 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6592 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6593 ssh2_pkt_send(ssh, s->pktout);
6594 s->type = AUTH_TYPE_NONE;
6595 s->gotit = FALSE;
6596 s->we_are_in = FALSE;
6597
6598 s->tried_pubkey_config = FALSE;
6599 s->tried_agent = FALSE;
6600 s->kbd_inter_running = FALSE;
6601 s->kbd_inter_refused = FALSE;
6602 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6603 if (!filename_is_null(ssh->cfg.keyfile)) {
6604 int keytype;
6605 logeventf(ssh, "Reading private key file \"%.150s\"",
6606 filename_to_str(&ssh->cfg.keyfile));
6607 keytype = key_type(&ssh->cfg.keyfile);
6608 if (keytype == SSH_KEYTYPE_SSH2) {
6609 s->publickey_blob =
6610 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6611 &s->publickey_bloblen, NULL);
6612 } else {
6613 char *msgbuf;
6614 logeventf(ssh, "Unable to use this key file (%s)",
6615 key_type_to_str(keytype));
6616 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6617 " (%s)\r\n",
6618 filename_to_str(&ssh->cfg.keyfile),
6619 key_type_to_str(keytype));
6620 c_write_str(ssh, msgbuf);
6621 sfree(msgbuf);
6622 s->publickey_blob = NULL;
6623 }
6624 } else
6625 s->publickey_blob = NULL;
6626
6627 while (1) {
6628 /*
6629 * Wait for the result of the last authentication request.
6630 */
6631 if (!s->gotit)
6632 crWaitUntilV(pktin);
6633 /*
6634 * Now is a convenient point to spew any banner material
6635 * that we've accumulated. (This should ensure that when
6636 * we exit the auth loop, we haven't any left to deal
6637 * with.)
6638 */
6639 {
6640 int size = bufchain_size(&ssh->banner);
6641 /*
6642 * Don't show the banner if we're operating in
6643 * non-verbose non-interactive mode. (It's probably
6644 * a script, which means nobody will read the
6645 * banner _anyway_, and moreover the printing of
6646 * the banner will screw up processing on the
6647 * output of (say) plink.)
6648 */
6649 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
6650 char *banner = snewn(size, char);
6651 bufchain_fetch(&ssh->banner, banner, size);
6652 c_write_untrusted(ssh, banner, size);
6653 sfree(banner);
6654 }
6655 bufchain_clear(&ssh->banner);
6656 }
6657 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6658 logevent("Access granted");
6659 s->we_are_in = TRUE;
6660 break;
6661 }
6662
6663 if (s->kbd_inter_running &&
6664 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6665 /*
6666 * This is either a further set-of-prompts packet
6667 * in keyboard-interactive authentication, or it's
6668 * the same one and we came back here with `gotit'
6669 * set. In the former case, we must reset the
6670 * curr_prompt variable.
6671 */
6672 if (!s->gotit)
6673 s->curr_prompt = 0;
6674 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6675 /* FIXME: perhaps we should support this? */
6676 bombout(("PASSWD_CHANGEREQ not yet supported"));
6677 crStopV;
6678 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6679 bombout(("Strange packet received during authentication: type %d",
6680 pktin->type));
6681 crStopV;
6682 }
6683
6684 s->gotit = FALSE;
6685
6686 /*
6687 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6688 * we can look at the string in it and know what we can
6689 * helpfully try next.
6690 */
6691 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6692 char *methods;
6693 int methlen;
6694 ssh_pkt_getstring(pktin, &methods, &methlen);
6695 s->kbd_inter_running = FALSE;
6696 if (!ssh2_pkt_getbool(pktin)) {
6697 /*
6698 * We have received an unequivocal Access
6699 * Denied. This can translate to a variety of
6700 * messages:
6701 *
6702 * - if we'd just tried "none" authentication,
6703 * it's not worth printing anything at all
6704 *
6705 * - if we'd just tried a public key _offer_,
6706 * the message should be "Server refused our
6707 * key" (or no message at all if the key
6708 * came from Pageant)
6709 *
6710 * - if we'd just tried anything else, the
6711 * message really should be "Access denied".
6712 *
6713 * Additionally, if we'd just tried password
6714 * authentication, we should break out of this
6715 * whole loop so as to go back to the username
6716 * prompt (iff we're configured to allow
6717 * username change attempts).
6718 */
6719 if (s->type == AUTH_TYPE_NONE) {
6720 /* do nothing */
6721 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6722 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6723 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6724 c_write_str(ssh, "Server refused our key\r\n");
6725 logevent("Server refused public key");
6726 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6727 /* server declined keyboard-interactive; ignore */
6728 } else {
6729 c_write_str(ssh, "Access denied\r\n");
6730 logevent("Access denied");
6731 if (s->type == AUTH_TYPE_PASSWORD &&
6732 ssh->cfg.change_username) {
6733 /* XXX perhaps we should allow
6734 * keyboard-interactive to do this too? */
6735 s->we_are_in = FALSE;
6736 break;
6737 }
6738 }
6739 } else {
6740 c_write_str(ssh, "Further authentication required\r\n");
6741 logevent("Further authentication required");
6742 }
6743
6744 s->can_pubkey =
6745 in_commasep_string("publickey", methods, methlen);
6746 s->can_passwd =
6747 in_commasep_string("password", methods, methlen);
6748 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6749 in_commasep_string("keyboard-interactive", methods, methlen);
6750 }
6751
6752 s->method = 0;
6753 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6754 s->need_pw = FALSE;
6755
6756 /*
6757 * Most password/passphrase prompts will be
6758 * non-echoing, so we set this to 0 by default.
6759 * Exception is that some keyboard-interactive prompts
6760 * can be echoing, in which case we'll set this to 1.
6761 */
6762 s->echo = 0;
6763
6764 if (!s->method && s->can_pubkey &&
6765 agent_exists() && !s->tried_agent) {
6766 /*
6767 * Attempt public-key authentication using Pageant.
6768 */
6769 void *r;
6770 s->authed = FALSE;
6771
6772 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6773 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6774
6775 s->tried_agent = TRUE;
6776
6777 logevent("Pageant is running. Requesting keys.");
6778
6779 /* Request the keys held by the agent. */
6780 PUT_32BIT(s->request, 1);
6781 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6782 if (!agent_query(s->request, 5, &r, &s->responselen,
6783 ssh_agent_callback, ssh)) {
6784 do {
6785 crReturnV;
6786 if (pktin) {
6787 bombout(("Unexpected data from server while"
6788 " waiting for agent response"));
6789 crStopV;
6790 }
6791 } while (pktin || inlen > 0);
6792 r = ssh->agent_response;
6793 s->responselen = ssh->agent_response_len;
6794 }
6795 s->response = (unsigned char *) r;
6796 if (s->response && s->responselen >= 5 &&
6797 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6798 s->p = s->response + 5;
6799 s->nkeys = GET_32BIT(s->p);
6800 s->p += 4;
6801 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6802 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6803 void *vret;
6804
6805 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6806 s->pklen = GET_32BIT(s->p);
6807 s->p += 4;
6808 if (s->publickey_blob &&
6809 s->pklen == s->publickey_bloblen &&
6810 !memcmp(s->p, s->publickey_blob,
6811 s->publickey_bloblen)) {
6812 logevent("This key matches configured key file");
6813 s->tried_pubkey_config = 1;
6814 }
6815 s->pkblob = (char *)s->p;
6816 s->p += s->pklen;
6817 s->alglen = GET_32BIT(s->pkblob);
6818 s->alg = s->pkblob + 4;
6819 s->commentlen = GET_32BIT(s->p);
6820 s->p += 4;
6821 s->commentp = (char *)s->p;
6822 s->p += s->commentlen;
6823 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6824 ssh2_pkt_addstring(s->pktout, s->username);
6825 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6826 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6827 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6828 ssh2_pkt_addstring_start(s->pktout);
6829 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6830 ssh2_pkt_addstring_start(s->pktout);
6831 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6832 ssh2_pkt_send(ssh, s->pktout);
6833
6834 crWaitUntilV(pktin);
6835 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6836 logevent("Key refused");
6837 continue;
6838 }
6839
6840 if (flags & FLAG_VERBOSE) {
6841 c_write_str(ssh, "Authenticating with "
6842 "public key \"");
6843 c_write(ssh, s->commentp, s->commentlen);
6844 c_write_str(ssh, "\" from agent\r\n");
6845 }
6846
6847 /*
6848 * Server is willing to accept the key.
6849 * Construct a SIGN_REQUEST.
6850 */
6851 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6852 ssh2_pkt_addstring(s->pktout, s->username);
6853 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6854 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6855 ssh2_pkt_addbool(s->pktout, TRUE);
6856 ssh2_pkt_addstring_start(s->pktout);
6857 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6858 ssh2_pkt_addstring_start(s->pktout);
6859 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6860
6861 s->siglen = s->pktout->length - 5 + 4 + 20;
6862 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6863 s->siglen -= 4;
6864 s->len = 1; /* message type */
6865 s->len += 4 + s->pklen; /* key blob */
6866 s->len += 4 + s->siglen; /* data to sign */
6867 s->len += 4; /* flags */
6868 s->agentreq = snewn(4 + s->len, char);
6869 PUT_32BIT(s->agentreq, s->len);
6870 s->q = s->agentreq + 4;
6871 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6872 PUT_32BIT(s->q, s->pklen);
6873 s->q += 4;
6874 memcpy(s->q, s->pkblob, s->pklen);
6875 s->q += s->pklen;
6876 PUT_32BIT(s->q, s->siglen);
6877 s->q += 4;
6878 /* Now the data to be signed... */
6879 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6880 PUT_32BIT(s->q, 20);
6881 s->q += 4;
6882 }
6883 memcpy(s->q, ssh->v2_session_id, 20);
6884 s->q += 20;
6885 memcpy(s->q, s->pktout->data + 5,
6886 s->pktout->length - 5);
6887 s->q += s->pktout->length - 5;
6888 /* And finally the (zero) flags word. */
6889 PUT_32BIT(s->q, 0);
6890 if (!agent_query(s->agentreq, s->len + 4,
6891 &vret, &s->retlen,
6892 ssh_agent_callback, ssh)) {
6893 do {
6894 crReturnV;
6895 if (pktin) {
6896 bombout(("Unexpected data from server"
6897 " while waiting for agent"
6898 " response"));
6899 crStopV;
6900 }
6901 } while (pktin || inlen > 0);
6902 vret = ssh->agent_response;
6903 s->retlen = ssh->agent_response_len;
6904 }
6905 s->ret = vret;
6906 sfree(s->agentreq);
6907 if (s->ret) {
6908 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6909 logevent("Sending Pageant's response");
6910 ssh2_add_sigblob(ssh, s->pktout,
6911 s->pkblob, s->pklen,
6912 s->ret + 9,
6913 GET_32BIT(s->ret + 5));
6914 ssh2_pkt_send(ssh, s->pktout);
6915 s->authed = TRUE;
6916 break;
6917 } else {
6918 logevent
6919 ("Pageant failed to answer challenge");
6920 sfree(s->ret);
6921 }
6922 }
6923 }
6924 if (s->authed)
6925 continue;
6926 }
6927 sfree(s->response);
6928 }
6929
6930 if (!s->method && s->can_pubkey && s->publickey_blob
6931 && !s->tried_pubkey_config) {
6932 unsigned char *pub_blob;
6933 char *algorithm, *comment;
6934 int pub_blob_len;
6935
6936 s->tried_pubkey_config = TRUE;
6937
6938 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6939 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6940
6941 /*
6942 * Try the public key supplied in the configuration.
6943 *
6944 * First, offer the public blob to see if the server is
6945 * willing to accept it.
6946 */
6947 pub_blob =
6948 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6949 &algorithm,
6950 &pub_blob_len,
6951 NULL);
6952 if (pub_blob) {
6953 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6954 ssh2_pkt_addstring(s->pktout, s->username);
6955 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6956 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6957 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6958 ssh2_pkt_addstring(s->pktout, algorithm);
6959 ssh2_pkt_addstring_start(s->pktout);
6960 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6961 pub_blob_len);
6962 ssh2_pkt_send(ssh, s->pktout);
6963 logevent("Offered public key");
6964
6965 crWaitUntilV(pktin);
6966 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6967 s->gotit = TRUE;
6968 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6969 continue; /* key refused; give up on it */
6970 }
6971
6972 logevent("Offer of public key accepted");
6973 /*
6974 * Actually attempt a serious authentication using
6975 * the key.
6976 */
6977 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6978 sprintf(s->pwprompt,
6979 "Passphrase for key \"%.100s\": ",
6980 comment);
6981 s->need_pw = TRUE;
6982 } else {
6983 s->need_pw = FALSE;
6984 }
6985 if (flags & FLAG_VERBOSE) {
6986 c_write_str(ssh, "Authenticating with public key \"");
6987 c_write_str(ssh, comment);
6988 c_write_str(ssh, "\"\r\n");
6989 }
6990 s->method = AUTH_PUBLICKEY_FILE;
6991 }
6992 }
6993
6994 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6995 !s->kbd_inter_running) {
6996 s->method = AUTH_KEYBOARD_INTERACTIVE;
6997 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6998
6999 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7000 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7001
7002 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7003 ssh2_pkt_addstring(s->pktout, s->username);
7004 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7005 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
7006 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7007 ssh2_pkt_addstring(s->pktout, "");
7008 ssh2_pkt_send(ssh, s->pktout);
7009
7010 crWaitUntilV(pktin);
7011 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7012 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7013 s->gotit = TRUE;
7014 logevent("Keyboard-interactive authentication refused");
7015 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7016 s->kbd_inter_refused = TRUE; /* don't try it again */
7017 continue;
7018 }
7019
7020 c_write_str(ssh, "Using keyboard-interactive authentication.\r\n");
7021 s->kbd_inter_running = TRUE;
7022 s->curr_prompt = 0;
7023 }
7024
7025 if (s->kbd_inter_running) {
7026 s->method = AUTH_KEYBOARD_INTERACTIVE;
7027 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7028
7029 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7030 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7031
7032 if (s->curr_prompt == 0) {
7033 /*
7034 * We've got a fresh USERAUTH_INFO_REQUEST.
7035 * Display header data, and start going through
7036 * the prompts.
7037 */
7038 char *name, *inst, *lang;
7039 int name_len, inst_len, lang_len;
7040
7041 ssh_pkt_getstring(pktin, &name, &name_len);
7042 ssh_pkt_getstring(pktin, &inst, &inst_len);
7043 ssh_pkt_getstring(pktin, &lang, &lang_len);
7044 if (name_len > 0) {
7045 c_write_untrusted(ssh, name, name_len);
7046 c_write_str(ssh, "\r\n");
7047 }
7048 if (inst_len > 0) {
7049 c_write_untrusted(ssh, inst, inst_len);
7050 c_write_str(ssh, "\r\n");
7051 }
7052 s->num_prompts = ssh_pkt_getuint32(pktin);
7053 }
7054
7055 /*
7056 * If there are prompts remaining in the packet,
7057 * display one and get a response.
7058 */
7059 if (s->curr_prompt < s->num_prompts) {
7060 char *prompt;
7061 int prompt_len;
7062
7063 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7064 if (prompt_len > 0) {
7065 static const char trunc[] = "<prompt truncated>: ";
7066 static const int prlen = sizeof(s->pwprompt) -
7067 lenof(trunc);
7068 if (prompt_len > prlen) {
7069 memcpy(s->pwprompt, prompt, prlen);
7070 strcpy(s->pwprompt + prlen, trunc);
7071 } else {
7072 memcpy(s->pwprompt, prompt, prompt_len);
7073 s->pwprompt[prompt_len] = '\0';
7074 }
7075 } else {
7076 strcpy(s->pwprompt,
7077 "<server failed to send prompt>: ");
7078 }
7079 s->echo = ssh2_pkt_getbool(pktin);
7080 s->need_pw = TRUE;
7081 } else
7082 s->need_pw = FALSE;
7083 }
7084
7085 if (!s->method && s->can_passwd) {
7086 s->method = AUTH_PASSWORD;
7087 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7088 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7089 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
7090 ssh->savedhost);
7091 s->need_pw = TRUE;
7092 }
7093
7094 if (s->need_pw) {
7095 if (ssh_get_line) {
7096 if (!ssh_get_line(s->pwprompt, s->password,
7097 sizeof(s->password), TRUE)) {
7098 /*
7099 * get_line failed to get a password (for
7100 * example because one was supplied on the
7101 * command line which has already failed to
7102 * work). Terminate.
7103 */
7104 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7105 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7106 FALSE);
7107 crStopV;
7108 }
7109 } else {
7110 int ret; /* need not be saved across crReturn */
7111 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
7112 ssh->send_ok = 1;
7113
7114 setup_userpass_input(ssh, s->password,
7115 sizeof(s->password), s->echo);
7116 do {
7117 crWaitUntilV(!pktin);
7118 ret = process_userpass_input(ssh, in, inlen);
7119 } while (ret == 0);
7120 if (ret < 0)
7121 cleanup_exit(0);
7122 c_write_str(ssh, "\r\n");
7123 }
7124 }
7125
7126 if (s->method == AUTH_PUBLICKEY_FILE) {
7127 /*
7128 * We have our passphrase. Now try the actual authentication.
7129 */
7130 struct ssh2_userkey *key;
7131 const char *error = NULL;
7132
7133 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
7134 &error);
7135 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7136 if (key == SSH2_WRONG_PASSPHRASE) {
7137 c_write_str(ssh, "Wrong passphrase\r\n");
7138 s->tried_pubkey_config = FALSE;
7139 } else {
7140 c_write_str(ssh, "Unable to load private key (");
7141 c_write_str(ssh, error);
7142 c_write_str(ssh, ")\r\n");
7143 s->tried_pubkey_config = TRUE;
7144 }
7145 /* Send a spurious AUTH_NONE to return to the top. */
7146 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7147 ssh2_pkt_addstring(s->pktout, s->username);
7148 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7149 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7150 ssh2_pkt_send(ssh, s->pktout);
7151 s->type = AUTH_TYPE_NONE;
7152 } else {
7153 unsigned char *pkblob, *sigblob, *sigdata;
7154 int pkblob_len, sigblob_len, sigdata_len;
7155 int p;
7156
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 */
7162 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7163 ssh2_pkt_addstring(s->pktout, s->username);
7164 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7165 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7166 ssh2_pkt_addbool(s->pktout, TRUE);
7167 ssh2_pkt_addstring(s->pktout, key->alg->name);
7168 pkblob = key->alg->public_blob(key->data, &pkblob_len);
7169 ssh2_pkt_addstring_start(s->pktout);
7170 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
7171
7172 /*
7173 * The data to be signed is:
7174 *
7175 * string session-id
7176 *
7177 * followed by everything so far placed in the
7178 * outgoing packet.
7179 */
7180 sigdata_len = s->pktout->length - 5 + 4 + 20;
7181 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7182 sigdata_len -= 4;
7183 sigdata = snewn(sigdata_len, unsigned char);
7184 p = 0;
7185 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7186 PUT_32BIT(sigdata+p, 20);
7187 p += 4;
7188 }
7189 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
7190 memcpy(sigdata+p, s->pktout->data + 5,
7191 s->pktout->length - 5);
7192 p += s->pktout->length - 5;
7193 assert(p == sigdata_len);
7194 sigblob = key->alg->sign(key->data, (char *)sigdata,
7195 sigdata_len, &sigblob_len);
7196 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7197 sigblob, sigblob_len);
7198 sfree(pkblob);
7199 sfree(sigblob);
7200 sfree(sigdata);
7201
7202 ssh2_pkt_send(ssh, s->pktout);
7203 s->type = AUTH_TYPE_PUBLICKEY;
7204 key->alg->freekey(key->data);
7205 }
7206 } else if (s->method == AUTH_PASSWORD) {
7207 /*
7208 * We pad out the password packet to 256 bytes to make
7209 * it harder for an attacker to find the length of the
7210 * user's password.
7211 *
7212 * Anyone using a password longer than 256 bytes
7213 * probably doesn't have much to worry about from
7214 * people who find out how long their password is!
7215 */
7216 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7217 s->pktout->forcepad = 256;
7218 ssh2_pkt_addstring(s->pktout, s->username);
7219 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7220 ssh2_pkt_addstring(s->pktout, "password");
7221 ssh2_pkt_addbool(s->pktout, FALSE);
7222 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7223 ssh2_pkt_addstring(s->pktout, s->password);
7224 memset(s->password, 0, sizeof(s->password));
7225 end_log_omission(ssh, s->pktout);
7226 ssh2_pkt_send(ssh, s->pktout);
7227 logevent("Sent password");
7228 s->type = AUTH_TYPE_PASSWORD;
7229 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7230 if (s->curr_prompt == 0) {
7231 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7232 s->pktout->forcepad = 256;
7233 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7234 }
7235 if (s->need_pw) { /* only add pw if we just got one! */
7236 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7237 ssh2_pkt_addstring(s->pktout, s->password);
7238 memset(s->password, 0, sizeof(s->password));
7239 end_log_omission(ssh, s->pktout);
7240 s->curr_prompt++;
7241 }
7242 if (s->curr_prompt >= s->num_prompts) {
7243 ssh2_pkt_send(ssh, s->pktout);
7244 } else {
7245 /*
7246 * If there are prompts remaining, we set
7247 * `gotit' so that we won't attempt to get
7248 * another packet. Then we go back round the
7249 * loop and will end up retrieving another
7250 * prompt out of the existing packet. Funky or
7251 * what?
7252 */
7253 s->gotit = TRUE;
7254 }
7255 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7256 } else {
7257 ssh_disconnect(ssh, NULL,
7258 "No supported authentication methods available",
7259 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7260 FALSE);
7261 crStopV;
7262 }
7263 }
7264 }
7265 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7266
7267 /*
7268 * Now the connection protocol has started, one way or another.
7269 */
7270
7271 ssh->channels = newtree234(ssh_channelcmp);
7272
7273 /*
7274 * Set up handlers for some connection protocol messages, so we
7275 * don't have to handle them repeatedly in this coroutine.
7276 */
7277 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7278 ssh2_msg_channel_window_adjust;
7279 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7280 ssh2_msg_global_request;
7281
7282 /*
7283 * Create the main session channel.
7284 */
7285 if (!ssh->cfg.ssh_no_shell) {
7286 ssh->mainchan = snew(struct ssh_channel);
7287 ssh->mainchan->ssh = ssh;
7288 ssh->mainchan->localid = alloc_channel_id(ssh);
7289 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7290 ssh2_pkt_addstring(s->pktout, "session");
7291 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7292 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7293 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7294 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7295 ssh2_pkt_send(ssh, s->pktout);
7296 crWaitUntilV(pktin);
7297 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7298 bombout(("Server refused to open a session"));
7299 crStopV;
7300 /* FIXME: error data comes back in FAILURE packet */
7301 }
7302 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7303 bombout(("Server's channel confirmation cited wrong channel"));
7304 crStopV;
7305 }
7306 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7307 ssh->mainchan->halfopen = FALSE;
7308 ssh->mainchan->type = CHAN_MAINSESSION;
7309 ssh->mainchan->closes = 0;
7310 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7311 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7312 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7313 add234(ssh->channels, ssh->mainchan);
7314 update_specials_menu(ssh->frontend);
7315 logevent("Opened channel for session");
7316 } else
7317 ssh->mainchan = NULL;
7318
7319 /*
7320 * Now we have a channel, make dispatch table entries for
7321 * general channel-based messages.
7322 */
7323 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7324 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7325 ssh2_msg_channel_data;
7326 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7327 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7328 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7329 ssh2_msg_channel_open_confirmation;
7330 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7331 ssh2_msg_channel_open_failure;
7332 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7333 ssh2_msg_channel_request;
7334 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7335 ssh2_msg_channel_open;
7336
7337 /*
7338 * Potentially enable X11 forwarding.
7339 */
7340 if (ssh->mainchan && ssh->cfg.x11_forward) {
7341 char proto[20], data[64];
7342 logevent("Requesting X11 forwarding");
7343 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7344 data, sizeof(data), ssh->cfg.x11_auth);
7345 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7346 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7347 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7348 ssh2_pkt_addstring(s->pktout, "x11-req");
7349 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7350 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7351 ssh2_pkt_addstring(s->pktout, proto);
7352 /*
7353 * Note that while we blank the X authentication data here, we don't
7354 * take any special action to blank the start of an X11 channel,
7355 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7356 * without having session blanking enabled is likely to leak your
7357 * cookie into the log.
7358 */
7359 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7360 ssh2_pkt_addstring(s->pktout, data);
7361 end_log_omission(ssh, s->pktout);
7362 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7363 ssh2_pkt_send(ssh, s->pktout);
7364
7365 crWaitUntilV(pktin);
7366
7367 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7368 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7369 bombout(("Unexpected response to X11 forwarding request:"
7370 " packet type %d", pktin->type));
7371 crStopV;
7372 }
7373 logevent("X11 forwarding refused");
7374 } else {
7375 logevent("X11 forwarding enabled");
7376 ssh->X11_fwd_enabled = TRUE;
7377 }
7378 }
7379
7380 /*
7381 * Enable port forwardings.
7382 */
7383 ssh_setup_portfwd(ssh, &ssh->cfg);
7384
7385 /*
7386 * Potentially enable agent forwarding.
7387 */
7388 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7389 logevent("Requesting OpenSSH-style agent forwarding");
7390 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7391 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7392 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7393 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7394 ssh2_pkt_send(ssh, s->pktout);
7395
7396 crWaitUntilV(pktin);
7397
7398 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7399 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7400 bombout(("Unexpected response to agent forwarding request:"
7401 " packet type %d", pktin->type));
7402 crStopV;
7403 }
7404 logevent("Agent forwarding refused");
7405 } else {
7406 logevent("Agent forwarding enabled");
7407 ssh->agentfwd_enabled = TRUE;
7408 }
7409 }
7410
7411 /*
7412 * Now allocate a pty for the session.
7413 */
7414 if (ssh->mainchan && !ssh->cfg.nopty) {
7415 /* Unpick the terminal-speed string. */
7416 /* XXX perhaps we should allow no speeds to be sent. */
7417 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7418 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7419 /* Build the pty request. */
7420 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7421 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7422 ssh2_pkt_addstring(s->pktout, "pty-req");
7423 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7424 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7425 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7426 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7427 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7428 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7429 ssh2_pkt_addstring_start(s->pktout);
7430 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7431 ssh2_send_ttymode, (void *)s->pktout);
7432 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
7433 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7434 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
7435 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7436 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7437 ssh2_pkt_send(ssh, s->pktout);
7438 ssh->state = SSH_STATE_INTERMED;
7439
7440 crWaitUntilV(pktin);
7441
7442 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7443 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7444 bombout(("Unexpected response to pty request:"
7445 " packet type %d", pktin->type));
7446 crStopV;
7447 }
7448 c_write_str(ssh, "Server refused to allocate pty\r\n");
7449 ssh->editing = ssh->echoing = 1;
7450 } else {
7451 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7452 ssh->ospeed, ssh->ispeed);
7453 }
7454 } else {
7455 ssh->editing = ssh->echoing = 1;
7456 }
7457
7458 /*
7459 * Send environment variables.
7460 *
7461 * Simplest thing here is to send all the requests at once, and
7462 * then wait for a whole bunch of successes or failures.
7463 */
7464 if (ssh->mainchan && *ssh->cfg.environmt) {
7465 char *e = ssh->cfg.environmt;
7466 char *var, *varend, *val;
7467
7468 s->num_env = 0;
7469
7470 while (*e) {
7471 var = e;
7472 while (*e && *e != '\t') e++;
7473 varend = e;
7474 if (*e == '\t') e++;
7475 val = e;
7476 while (*e) e++;
7477 e++;
7478
7479 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7480 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7481 ssh2_pkt_addstring(s->pktout, "env");
7482 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7483 ssh2_pkt_addstring_start(s->pktout);
7484 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7485 ssh2_pkt_addstring(s->pktout, val);
7486 ssh2_pkt_send(ssh, s->pktout);
7487
7488 s->num_env++;
7489 }
7490
7491 logeventf(ssh, "Sent %d environment variables", s->num_env);
7492
7493 s->env_ok = 0;
7494 s->env_left = s->num_env;
7495
7496 while (s->env_left > 0) {
7497 crWaitUntilV(pktin);
7498
7499 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7500 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7501 bombout(("Unexpected response to environment request:"
7502 " packet type %d", pktin->type));
7503 crStopV;
7504 }
7505 } else {
7506 s->env_ok++;
7507 }
7508
7509 s->env_left--;
7510 }
7511
7512 if (s->env_ok == s->num_env) {
7513 logevent("All environment variables successfully set");
7514 } else if (s->env_ok == 0) {
7515 logevent("All environment variables refused");
7516 c_write_str(ssh, "Server refused to set environment variables\r\n");
7517 } else {
7518 logeventf(ssh, "%d environment variables refused",
7519 s->num_env - s->env_ok);
7520 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7521 }
7522 }
7523
7524 /*
7525 * Start a shell or a remote command. We may have to attempt
7526 * this twice if the config data has provided a second choice
7527 * of command.
7528 */
7529 if (ssh->mainchan) while (1) {
7530 int subsys;
7531 char *cmd;
7532
7533 if (ssh->fallback_cmd) {
7534 subsys = ssh->cfg.ssh_subsys2;
7535 cmd = ssh->cfg.remote_cmd_ptr2;
7536 } else {
7537 subsys = ssh->cfg.ssh_subsys;
7538 cmd = ssh->cfg.remote_cmd_ptr;
7539 if (!cmd) cmd = ssh->cfg.remote_cmd;
7540 }
7541
7542 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7543 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7544 if (subsys) {
7545 ssh2_pkt_addstring(s->pktout, "subsystem");
7546 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7547 ssh2_pkt_addstring(s->pktout, cmd);
7548 } else if (*cmd) {
7549 ssh2_pkt_addstring(s->pktout, "exec");
7550 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7551 ssh2_pkt_addstring(s->pktout, cmd);
7552 } else {
7553 ssh2_pkt_addstring(s->pktout, "shell");
7554 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7555 }
7556 ssh2_pkt_send(ssh, s->pktout);
7557
7558 crWaitUntilV(pktin);
7559
7560 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7561 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7562 bombout(("Unexpected response to shell/command request:"
7563 " packet type %d", pktin->type));
7564 crStopV;
7565 }
7566 /*
7567 * We failed to start the command. If this is the
7568 * fallback command, we really are finished; if it's
7569 * not, and if the fallback command exists, try falling
7570 * back to it before complaining.
7571 */
7572 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7573 logevent("Primary command failed; attempting fallback");
7574 ssh->fallback_cmd = TRUE;
7575 continue;
7576 }
7577 bombout(("Server refused to start a shell/command"));
7578 crStopV;
7579 } else {
7580 logevent("Started a shell/command");
7581 }
7582 break;
7583 }
7584
7585 ssh->state = SSH_STATE_SESSION;
7586 if (ssh->size_needed)
7587 ssh_size(ssh, ssh->term_width, ssh->term_height);
7588 if (ssh->eof_needed)
7589 ssh_special(ssh, TS_EOF);
7590
7591 /*
7592 * Transfer data!
7593 */
7594 if (ssh->ldisc)
7595 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7596 if (ssh->mainchan)
7597 ssh->send_ok = 1;
7598 while (1) {
7599 crReturnV;
7600 s->try_send = FALSE;
7601 if (pktin) {
7602
7603 /*
7604 * _All_ the connection-layer packets we expect to
7605 * receive are now handled by the dispatch table.
7606 * Anything that reaches here must be bogus.
7607 */
7608
7609 bombout(("Strange packet received: type %d", pktin->type));
7610 crStopV;
7611 } else if (ssh->mainchan) {
7612 /*
7613 * We have spare data. Add it to the channel buffer.
7614 */
7615 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7616 s->try_send = TRUE;
7617 }
7618 if (s->try_send) {
7619 int i;
7620 struct ssh_channel *c;
7621 /*
7622 * Try to send data on all channels if we can.
7623 */
7624 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7625 ssh2_try_send_and_unthrottle(c);
7626 }
7627 }
7628
7629 crFinishV;
7630 }
7631
7632 /*
7633 * Handlers for SSH-2 messages that might arrive at any moment.
7634 */
7635 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7636 {
7637 /* log reason code in disconnect message */
7638 char *buf, *msg;
7639 int nowlen, reason, msglen;
7640
7641 reason = ssh_pkt_getuint32(pktin);
7642 ssh_pkt_getstring(pktin, &msg, &msglen);
7643
7644 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7645 buf = dupprintf("Received disconnect message (%s)",
7646 ssh2_disconnect_reasons[reason]);
7647 } else {
7648 buf = dupprintf("Received disconnect message (unknown"
7649 " type %d)", reason);
7650 }
7651 logevent(buf);
7652 sfree(buf);
7653 buf = dupprintf("Disconnection message text: %n%.*s",
7654 &nowlen, msglen, msg);
7655 logevent(buf);
7656 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7657 reason,
7658 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7659 ssh2_disconnect_reasons[reason] : "unknown",
7660 buf+nowlen));
7661 sfree(buf);
7662 }
7663
7664 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7665 {
7666 /* log the debug message */
7667 char *msg;
7668 int msglen;
7669 int always_display;
7670
7671 /* XXX maybe we should actually take notice of this */
7672 always_display = ssh2_pkt_getbool(pktin);
7673 ssh_pkt_getstring(pktin, &msg, &msglen);
7674
7675 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7676 }
7677
7678 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7679 {
7680 struct Packet *pktout;
7681 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7682 ssh2_pkt_adduint32(pktout, pktin->sequence);
7683 /*
7684 * UNIMPLEMENTED messages MUST appear in the same order as the
7685 * messages they respond to. Hence, never queue them.
7686 */
7687 ssh2_pkt_send_noqueue(ssh, pktout);
7688 }
7689
7690 /*
7691 * Handle the top-level SSH-2 protocol.
7692 */
7693 static void ssh2_protocol_setup(Ssh ssh)
7694 {
7695 int i;
7696
7697 /*
7698 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7699 */
7700 for (i = 0; i < 256; i++)
7701 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7702
7703 /*
7704 * Any message we actually understand, we set to NULL so that
7705 * the coroutines will get it.
7706 */
7707 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7708 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7709 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7710 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7711 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7712 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7713 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7714 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7715 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7716 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7717 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7718 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7719 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7720 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7721 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7722 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7723 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7724 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7725 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7726 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7727 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7728 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7729 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7730 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7731 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7732 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7733 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7734 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7735 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7736 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7737 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7738 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7739 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7740
7741 /*
7742 * These special message types we install handlers for.
7743 */
7744 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7745 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
7746 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7747 }
7748
7749 static void ssh2_timer(void *ctx, long now)
7750 {
7751 Ssh ssh = (Ssh)ctx;
7752
7753 if (ssh->state == SSH_STATE_CLOSED)
7754 return;
7755
7756 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7757 now - ssh->next_rekey >= 0) {
7758 do_ssh2_transport(ssh, "timeout", -1, NULL);
7759 }
7760 }
7761
7762 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7763 struct Packet *pktin)
7764 {
7765 unsigned char *in = (unsigned char *)vin;
7766 if (ssh->state == SSH_STATE_CLOSED)
7767 return;
7768
7769 if (pktin) {
7770 ssh->incoming_data_size += pktin->encrypted_len;
7771 if (!ssh->kex_in_progress &&
7772 ssh->max_data_size != 0 &&
7773 ssh->incoming_data_size > ssh->max_data_size)
7774 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7775 }
7776
7777 if (pktin && ssh->packet_dispatch[pktin->type]) {
7778 ssh->packet_dispatch[pktin->type](ssh, pktin);
7779 return;
7780 }
7781
7782 if (!ssh->protocol_initial_phase_done ||
7783 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7784 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7785 !ssh->protocol_initial_phase_done) {
7786 ssh->protocol_initial_phase_done = TRUE;
7787 /*
7788 * Allow authconn to initialise itself.
7789 */
7790 do_ssh2_authconn(ssh, NULL, 0, NULL);
7791 }
7792 } else {
7793 do_ssh2_authconn(ssh, in, inlen, pktin);
7794 }
7795 }
7796
7797 /*
7798 * Called to set up the connection.
7799 *
7800 * Returns an error message, or NULL on success.
7801 */
7802 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7803 Config *cfg,
7804 char *host, int port, char **realhost, int nodelay,
7805 int keepalive)
7806 {
7807 const char *p;
7808 Ssh ssh;
7809
7810 ssh = snew(struct ssh_tag);
7811 ssh->cfg = *cfg; /* STRUCTURE COPY */
7812 ssh->version = 0; /* when not ready yet */
7813 ssh->s = NULL;
7814 ssh->cipher = NULL;
7815 ssh->v1_cipher_ctx = NULL;
7816 ssh->crcda_ctx = NULL;
7817 ssh->cscipher = NULL;
7818 ssh->cs_cipher_ctx = NULL;
7819 ssh->sccipher = NULL;
7820 ssh->sc_cipher_ctx = NULL;
7821 ssh->csmac = NULL;
7822 ssh->cs_mac_ctx = NULL;
7823 ssh->scmac = NULL;
7824 ssh->sc_mac_ctx = NULL;
7825 ssh->cscomp = NULL;
7826 ssh->cs_comp_ctx = NULL;
7827 ssh->sccomp = NULL;
7828 ssh->sc_comp_ctx = NULL;
7829 ssh->kex = NULL;
7830 ssh->kex_ctx = NULL;
7831 ssh->hostkey = NULL;
7832 ssh->exitcode = -1;
7833 ssh->close_expected = FALSE;
7834 ssh->clean_exit = FALSE;
7835 ssh->state = SSH_STATE_PREPACKET;
7836 ssh->size_needed = FALSE;
7837 ssh->eof_needed = FALSE;
7838 ssh->ldisc = NULL;
7839 ssh->logctx = NULL;
7840 ssh->deferred_send_data = NULL;
7841 ssh->deferred_len = 0;
7842 ssh->deferred_size = 0;
7843 ssh->fallback_cmd = 0;
7844 ssh->pkt_ctx = 0;
7845 ssh->x11auth = NULL;
7846 ssh->v1_compressing = FALSE;
7847 ssh->v2_outgoing_sequence = 0;
7848 ssh->ssh1_rdpkt_crstate = 0;
7849 ssh->ssh2_rdpkt_crstate = 0;
7850 ssh->do_ssh_init_crstate = 0;
7851 ssh->ssh_gotdata_crstate = 0;
7852 ssh->do_ssh1_connection_crstate = 0;
7853 ssh->do_ssh1_login_crstate = 0;
7854 ssh->do_ssh2_transport_crstate = 0;
7855 ssh->do_ssh2_authconn_crstate = 0;
7856 ssh->do_ssh_init_state = NULL;
7857 ssh->do_ssh1_login_state = NULL;
7858 ssh->do_ssh2_transport_state = NULL;
7859 ssh->do_ssh2_authconn_state = NULL;
7860 ssh->mainchan = NULL;
7861 ssh->throttled_all = 0;
7862 ssh->v1_stdout_throttling = 0;
7863 ssh->queue = NULL;
7864 ssh->queuelen = ssh->queuesize = 0;
7865 ssh->queueing = FALSE;
7866 ssh->qhead = ssh->qtail = NULL;
7867 ssh->deferred_rekey_reason = NULL;
7868 bufchain_init(&ssh->queued_incoming_data);
7869 ssh->frozen = FALSE;
7870
7871 *backend_handle = ssh;
7872
7873 #ifdef MSCRYPTOAPI
7874 if (crypto_startup() == 0)
7875 return "Microsoft high encryption pack not installed!";
7876 #endif
7877
7878 ssh->frontend = frontend_handle;
7879 ssh->term_width = ssh->cfg.width;
7880 ssh->term_height = ssh->cfg.height;
7881
7882 ssh->channels = NULL;
7883 ssh->rportfwds = NULL;
7884 ssh->portfwds = NULL;
7885
7886 ssh->send_ok = 0;
7887 ssh->editing = 0;
7888 ssh->echoing = 0;
7889 ssh->v1_throttle_count = 0;
7890 ssh->overall_bufsize = 0;
7891 ssh->fallback_cmd = 0;
7892
7893 ssh->protocol = NULL;
7894
7895 ssh->protocol_initial_phase_done = FALSE;
7896
7897 ssh->pinger = NULL;
7898
7899 ssh->incoming_data_size = ssh->outgoing_data_size =
7900 ssh->deferred_data_size = 0L;
7901 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7902 ssh->kex_in_progress = FALSE;
7903
7904 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7905 if (p != NULL)
7906 return p;
7907
7908 random_ref();
7909
7910 return NULL;
7911 }
7912
7913 static void ssh_free(void *handle)
7914 {
7915 Ssh ssh = (Ssh) handle;
7916 struct ssh_channel *c;
7917 struct ssh_rportfwd *pf;
7918
7919 if (ssh->v1_cipher_ctx)
7920 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7921 if (ssh->cs_cipher_ctx)
7922 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7923 if (ssh->sc_cipher_ctx)
7924 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7925 if (ssh->cs_mac_ctx)
7926 ssh->csmac->free_context(ssh->cs_mac_ctx);
7927 if (ssh->sc_mac_ctx)
7928 ssh->scmac->free_context(ssh->sc_mac_ctx);
7929 if (ssh->cs_comp_ctx) {
7930 if (ssh->cscomp)
7931 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7932 else
7933 zlib_compress_cleanup(ssh->cs_comp_ctx);
7934 }
7935 if (ssh->sc_comp_ctx) {
7936 if (ssh->sccomp)
7937 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7938 else
7939 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7940 }
7941 if (ssh->kex_ctx)
7942 dh_cleanup(ssh->kex_ctx);
7943 sfree(ssh->savedhost);
7944
7945 while (ssh->queuelen-- > 0)
7946 ssh_free_packet(ssh->queue[ssh->queuelen]);
7947 sfree(ssh->queue);
7948
7949 while (ssh->qhead) {
7950 struct queued_handler *qh = ssh->qhead;
7951 ssh->qhead = qh->next;
7952 sfree(ssh->qhead);
7953 }
7954 ssh->qhead = ssh->qtail = NULL;
7955
7956 if (ssh->channels) {
7957 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7958 switch (c->type) {
7959 case CHAN_X11:
7960 if (c->u.x11.s != NULL)
7961 x11_close(c->u.x11.s);
7962 break;
7963 case CHAN_SOCKDATA:
7964 if (c->u.pfd.s != NULL)
7965 pfd_close(c->u.pfd.s);
7966 break;
7967 }
7968 sfree(c);
7969 }
7970 freetree234(ssh->channels);
7971 ssh->channels = NULL;
7972 }
7973
7974 if (ssh->rportfwds) {
7975 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7976 sfree(pf);
7977 freetree234(ssh->rportfwds);
7978 ssh->rportfwds = NULL;
7979 }
7980 sfree(ssh->deferred_send_data);
7981 if (ssh->x11auth)
7982 x11_free_auth(ssh->x11auth);
7983 sfree(ssh->do_ssh_init_state);
7984 sfree(ssh->do_ssh1_login_state);
7985 sfree(ssh->do_ssh2_transport_state);
7986 sfree(ssh->do_ssh2_authconn_state);
7987 if (ssh->crcda_ctx) {
7988 crcda_free_context(ssh->crcda_ctx);
7989 ssh->crcda_ctx = NULL;
7990 }
7991 if (ssh->s)
7992 ssh_do_close(ssh, TRUE);
7993 expire_timer_context(ssh);
7994 if (ssh->pinger)
7995 pinger_free(ssh->pinger);
7996 bufchain_clear(&ssh->queued_incoming_data);
7997 sfree(ssh);
7998
7999 random_unref();
8000 }
8001
8002 /*
8003 * Reconfigure the SSH backend.
8004 */
8005 static void ssh_reconfig(void *handle, Config *cfg)
8006 {
8007 Ssh ssh = (Ssh) handle;
8008 char *rekeying = NULL, rekey_mandatory = FALSE;
8009 unsigned long old_max_data_size;
8010
8011 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8012 if (ssh->portfwds)
8013 ssh_setup_portfwd(ssh, cfg);
8014
8015 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8016 cfg->ssh_rekey_time != 0) {
8017 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8018 long now = GETTICKCOUNT();
8019
8020 if (new_next - now < 0) {
8021 rekeying = "timeout shortened";
8022 } else {
8023 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8024 }
8025 }
8026
8027 old_max_data_size = ssh->max_data_size;
8028 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8029 if (old_max_data_size != ssh->max_data_size &&
8030 ssh->max_data_size != 0) {
8031 if (ssh->outgoing_data_size > ssh->max_data_size ||
8032 ssh->incoming_data_size > ssh->max_data_size)
8033 rekeying = "data limit lowered";
8034 }
8035
8036 if (ssh->cfg.compression != cfg->compression) {
8037 rekeying = "compression setting changed";
8038 rekey_mandatory = TRUE;
8039 }
8040
8041 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8042 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8043 sizeof(ssh->cfg.ssh_cipherlist))) {
8044 rekeying = "cipher settings changed";
8045 rekey_mandatory = TRUE;
8046 }
8047
8048 ssh->cfg = *cfg; /* STRUCTURE COPY */
8049
8050 if (rekeying) {
8051 if (!ssh->kex_in_progress) {
8052 do_ssh2_transport(ssh, rekeying, -1, NULL);
8053 } else if (rekey_mandatory) {
8054 ssh->deferred_rekey_reason = rekeying;
8055 }
8056 }
8057 }
8058
8059 /*
8060 * Called to send data down the SSH connection.
8061 */
8062 static int ssh_send(void *handle, char *buf, int len)
8063 {
8064 Ssh ssh = (Ssh) handle;
8065
8066 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8067 return 0;
8068
8069 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8070
8071 return ssh_sendbuffer(ssh);
8072 }
8073
8074 /*
8075 * Called to query the current amount of buffered stdin data.
8076 */
8077 static int ssh_sendbuffer(void *handle)
8078 {
8079 Ssh ssh = (Ssh) handle;
8080 int override_value;
8081
8082 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8083 return 0;
8084
8085 /*
8086 * If the SSH socket itself has backed up, add the total backup
8087 * size on that to any individual buffer on the stdin channel.
8088 */
8089 override_value = 0;
8090 if (ssh->throttled_all)
8091 override_value = ssh->overall_bufsize;
8092
8093 if (ssh->version == 1) {
8094 return override_value;
8095 } else if (ssh->version == 2) {
8096 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8097 return override_value;
8098 else
8099 return (override_value +
8100 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8101 }
8102
8103 return 0;
8104 }
8105
8106 /*
8107 * Called to set the size of the window from SSH's POV.
8108 */
8109 static void ssh_size(void *handle, int width, int height)
8110 {
8111 Ssh ssh = (Ssh) handle;
8112 struct Packet *pktout;
8113
8114 ssh->term_width = width;
8115 ssh->term_height = height;
8116
8117 switch (ssh->state) {
8118 case SSH_STATE_BEFORE_SIZE:
8119 case SSH_STATE_PREPACKET:
8120 case SSH_STATE_CLOSED:
8121 break; /* do nothing */
8122 case SSH_STATE_INTERMED:
8123 ssh->size_needed = TRUE; /* buffer for later */
8124 break;
8125 case SSH_STATE_SESSION:
8126 if (!ssh->cfg.nopty) {
8127 if (ssh->version == 1) {
8128 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8129 PKT_INT, ssh->term_height,
8130 PKT_INT, ssh->term_width,
8131 PKT_INT, 0, PKT_INT, 0, PKT_END);
8132 } else if (ssh->mainchan) {
8133 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8134 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8135 ssh2_pkt_addstring(pktout, "window-change");
8136 ssh2_pkt_addbool(pktout, 0);
8137 ssh2_pkt_adduint32(pktout, ssh->term_width);
8138 ssh2_pkt_adduint32(pktout, ssh->term_height);
8139 ssh2_pkt_adduint32(pktout, 0);
8140 ssh2_pkt_adduint32(pktout, 0);
8141 ssh2_pkt_send(ssh, pktout);
8142 }
8143 }
8144 break;
8145 }
8146 }
8147
8148 /*
8149 * Return a list of the special codes that make sense in this
8150 * protocol.
8151 */
8152 static const struct telnet_special *ssh_get_specials(void *handle)
8153 {
8154 static const struct telnet_special ssh1_ignore_special[] = {
8155 {"IGNORE message", TS_NOP}
8156 };
8157 static const struct telnet_special ssh2_transport_specials[] = {
8158 {"IGNORE message", TS_NOP},
8159 {"Repeat key exchange", TS_REKEY},
8160 };
8161 static const struct telnet_special ssh2_session_specials[] = {
8162 {NULL, TS_SEP},
8163 {"Break", TS_BRK},
8164 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8165 * They include all the ISO C signals, but are a subset of the POSIX
8166 * required signals. */
8167 {"SIGINT (Interrupt)", TS_SIGINT},
8168 {"SIGTERM (Terminate)", TS_SIGTERM},
8169 {"SIGKILL (Kill)", TS_SIGKILL},
8170 {"SIGQUIT (Quit)", TS_SIGQUIT},
8171 {"SIGHUP (Hangup)", TS_SIGHUP},
8172 {"More signals", TS_SUBMENU},
8173 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8174 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8175 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8176 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8177 {NULL, TS_EXITMENU}
8178 };
8179 static const struct telnet_special specials_end[] = {
8180 {NULL, TS_EXITMENU}
8181 };
8182 /* XXX review this length for any changes: */
8183 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8184 lenof(ssh2_session_specials) +
8185 lenof(specials_end)];
8186 Ssh ssh = (Ssh) handle;
8187 int i = 0;
8188 #define ADD_SPECIALS(name) \
8189 do { \
8190 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8191 memcpy(&ssh_specials[i], name, sizeof name); \
8192 i += lenof(name); \
8193 } while(0)
8194
8195 if (ssh->version == 1) {
8196 /* Don't bother offering IGNORE if we've decided the remote
8197 * won't cope with it, since we wouldn't bother sending it if
8198 * asked anyway. */
8199 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8200 ADD_SPECIALS(ssh1_ignore_special);
8201 } else if (ssh->version == 2) {
8202 ADD_SPECIALS(ssh2_transport_specials);
8203 if (ssh->mainchan)
8204 ADD_SPECIALS(ssh2_session_specials);
8205 } /* else we're not ready yet */
8206
8207 if (i) {
8208 ADD_SPECIALS(specials_end);
8209 return ssh_specials;
8210 } else {
8211 return NULL;
8212 }
8213 #undef ADD_SPECIALS
8214 }
8215
8216 /*
8217 * Send special codes. TS_EOF is useful for `plink', so you
8218 * can send an EOF and collect resulting output (e.g. `plink
8219 * hostname sort').
8220 */
8221 static void ssh_special(void *handle, Telnet_Special code)
8222 {
8223 Ssh ssh = (Ssh) handle;
8224 struct Packet *pktout;
8225
8226 if (code == TS_EOF) {
8227 if (ssh->state != SSH_STATE_SESSION) {
8228 /*
8229 * Buffer the EOF in case we are pre-SESSION, so we can
8230 * send it as soon as we reach SESSION.
8231 */
8232 if (code == TS_EOF)
8233 ssh->eof_needed = TRUE;
8234 return;
8235 }
8236 if (ssh->version == 1) {
8237 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8238 } else if (ssh->mainchan) {
8239 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8240 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8241 ssh2_pkt_send(ssh, pktout);
8242 ssh->send_ok = 0; /* now stop trying to read from stdin */
8243 }
8244 logevent("Sent EOF message");
8245 } else if (code == TS_PING || code == TS_NOP) {
8246 if (ssh->state == SSH_STATE_CLOSED
8247 || ssh->state == SSH_STATE_PREPACKET) return;
8248 if (ssh->version == 1) {
8249 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8250 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8251 } else {
8252 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8253 ssh2_pkt_addstring_start(pktout);
8254 ssh2_pkt_send_noqueue(ssh, pktout);
8255 }
8256 } else if (code == TS_REKEY) {
8257 if (!ssh->kex_in_progress && ssh->version == 2) {
8258 do_ssh2_transport(ssh, "at user request", -1, NULL);
8259 }
8260 } else if (code == TS_BRK) {
8261 if (ssh->state == SSH_STATE_CLOSED
8262 || ssh->state == SSH_STATE_PREPACKET) return;
8263 if (ssh->version == 1) {
8264 logevent("Unable to send BREAK signal in SSH-1");
8265 } else if (ssh->mainchan) {
8266 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8267 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8268 ssh2_pkt_addstring(pktout, "break");
8269 ssh2_pkt_addbool(pktout, 0);
8270 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8271 ssh2_pkt_send(ssh, pktout);
8272 }
8273 } else {
8274 /* Is is a POSIX signal? */
8275 char *signame = NULL;
8276 if (code == TS_SIGABRT) signame = "ABRT";
8277 if (code == TS_SIGALRM) signame = "ALRM";
8278 if (code == TS_SIGFPE) signame = "FPE";
8279 if (code == TS_SIGHUP) signame = "HUP";
8280 if (code == TS_SIGILL) signame = "ILL";
8281 if (code == TS_SIGINT) signame = "INT";
8282 if (code == TS_SIGKILL) signame = "KILL";
8283 if (code == TS_SIGPIPE) signame = "PIPE";
8284 if (code == TS_SIGQUIT) signame = "QUIT";
8285 if (code == TS_SIGSEGV) signame = "SEGV";
8286 if (code == TS_SIGTERM) signame = "TERM";
8287 if (code == TS_SIGUSR1) signame = "USR1";
8288 if (code == TS_SIGUSR2) signame = "USR2";
8289 /* The SSH-2 protocol does in principle support arbitrary named
8290 * signals, including signame@domain, but we don't support those. */
8291 if (signame) {
8292 /* It's a signal. */
8293 if (ssh->version == 2 && ssh->mainchan) {
8294 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8295 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8296 ssh2_pkt_addstring(pktout, "signal");
8297 ssh2_pkt_addbool(pktout, 0);
8298 ssh2_pkt_addstring(pktout, signame);
8299 ssh2_pkt_send(ssh, pktout);
8300 logeventf(ssh, "Sent signal SIG%s", signame);
8301 }
8302 } else {
8303 /* Never heard of it. Do nothing */
8304 }
8305 }
8306 }
8307
8308 void *new_sock_channel(void *handle, Socket s)
8309 {
8310 Ssh ssh = (Ssh) handle;
8311 struct ssh_channel *c;
8312 c = snew(struct ssh_channel);
8313 c->ssh = ssh;
8314
8315 if (c) {
8316 c->halfopen = TRUE;
8317 c->localid = alloc_channel_id(ssh);
8318 c->closes = 0;
8319 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8320 c->u.pfd.s = s;
8321 bufchain_init(&c->v.v2.outbuffer);
8322 add234(ssh->channels, c);
8323 }
8324 return c;
8325 }
8326
8327 /*
8328 * This is called when stdout/stderr (the entity to which
8329 * from_backend sends data) manages to clear some backlog.
8330 */
8331 static void ssh_unthrottle(void *handle, int bufsize)
8332 {
8333 Ssh ssh = (Ssh) handle;
8334 if (ssh->version == 1) {
8335 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8336 ssh->v1_stdout_throttling = 0;
8337 ssh1_throttle(ssh, -1);
8338 }
8339 } else {
8340 if (ssh->mainchan && ssh->mainchan->closes == 0)
8341 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8342 }
8343 }
8344
8345 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8346 {
8347 struct ssh_channel *c = (struct ssh_channel *)channel;
8348 Ssh ssh = c->ssh;
8349 struct Packet *pktout;
8350
8351 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8352
8353 if (ssh->version == 1) {
8354 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8355 PKT_INT, c->localid,
8356 PKT_STR, hostname,
8357 PKT_INT, port,
8358 /* PKT_STR, <org:orgport>, */
8359 PKT_END);
8360 } else {
8361 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8362 ssh2_pkt_addstring(pktout, "direct-tcpip");
8363 ssh2_pkt_adduint32(pktout, c->localid);
8364 c->v.v2.locwindow = OUR_V2_WINSIZE;
8365 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8366 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8367 ssh2_pkt_addstring(pktout, hostname);
8368 ssh2_pkt_adduint32(pktout, port);
8369 /*
8370 * We make up values for the originator data; partly it's
8371 * too much hassle to keep track, and partly I'm not
8372 * convinced the server should be told details like that
8373 * about my local network configuration.
8374 */
8375 ssh2_pkt_addstring(pktout, "client-side-connection");
8376 ssh2_pkt_adduint32(pktout, 0);
8377 ssh2_pkt_send(ssh, pktout);
8378 }
8379 }
8380
8381 static Socket ssh_socket(void *handle)
8382 {
8383 Ssh ssh = (Ssh) handle;
8384 return ssh->s;
8385 }
8386
8387 static int ssh_sendok(void *handle)
8388 {
8389 Ssh ssh = (Ssh) handle;
8390 return ssh->send_ok;
8391 }
8392
8393 static int ssh_ldisc(void *handle, int option)
8394 {
8395 Ssh ssh = (Ssh) handle;
8396 if (option == LD_ECHO)
8397 return ssh->echoing;
8398 if (option == LD_EDIT)
8399 return ssh->editing;
8400 return FALSE;
8401 }
8402
8403 static void ssh_provide_ldisc(void *handle, void *ldisc)
8404 {
8405 Ssh ssh = (Ssh) handle;
8406 ssh->ldisc = ldisc;
8407 }
8408
8409 static void ssh_provide_logctx(void *handle, void *logctx)
8410 {
8411 Ssh ssh = (Ssh) handle;
8412 ssh->logctx = logctx;
8413 }
8414
8415 static int ssh_return_exitcode(void *handle)
8416 {
8417 Ssh ssh = (Ssh) handle;
8418 if (ssh->s != NULL)
8419 return -1;
8420 else
8421 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8422 }
8423
8424 /*
8425 * cfg_info for SSH is the currently running version of the
8426 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8427 */
8428 static int ssh_cfg_info(void *handle)
8429 {
8430 Ssh ssh = (Ssh) handle;
8431 return ssh->version;
8432 }
8433
8434 /*
8435 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8436 * that fails. This variable is the means by which scp.c can reach
8437 * into the SSH code and find out which one it got.
8438 */
8439 extern int ssh_fallback_cmd(void *handle)
8440 {
8441 Ssh ssh = (Ssh) handle;
8442 return ssh->fallback_cmd;
8443 }
8444
8445 Backend ssh_backend = {
8446 ssh_init,
8447 ssh_free,
8448 ssh_reconfig,
8449 ssh_send,
8450 ssh_sendbuffer,
8451 ssh_size,
8452 ssh_special,
8453 ssh_get_specials,
8454 ssh_socket,
8455 ssh_return_exitcode,
8456 ssh_sendok,
8457 ssh_ldisc,
8458 ssh_provide_ldisc,
8459 ssh_provide_logctx,
8460 ssh_unthrottle,
8461 ssh_cfg_info,
8462 22
8463 };