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 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
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 */
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 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
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
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 */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "host not allowed to connect",
135 "key exchange failed",
136 "host authentication failed",
139 "service not available",
140 "protocol version not supported",
141 "host key not verifiable",
144 "too many connections",
145 "auth cancelled by user",
146 "no more auth methods available",
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 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
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
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
175 static const struct {
176 const char* const mode;
178 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
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 }
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
244 /* Helper functions for parsing tty-related config. */
245 static unsigned int ssh_tty_parse_specchar(char *s)
250 ret = ctrlparse(s, &next);
251 if (!next) ret = s[0];
253 ret = 255; /* special value meaning "don't set" */
257 static unsigned int ssh_tty_parse_boolean(char *s)
259 if (stricmp(s, "yes") == 0 ||
260 stricmp(s, "on") == 0 ||
261 stricmp(s, "true") == 0 ||
262 stricmp(s, "+") == 0)
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 */
270 return (atoi(s) != 0);
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)
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);
320 static char *ssh2_pkt_type(int pkt_ctx, int type)
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);
363 /* Enumeration values for fields in SSH-1 packets */
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
372 * Coroutine mechanics for the sillier bits of the code. If these
373 * macros look impenetrable to you, you might find it helpful to
376 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
378 * which explains the theory behind these macros.
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:
385 * - right-click ssh.c in the FileView
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'.
391 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
394 if (!ssh->t) ssh->t = snew(struct t); \
396 #define crFinish(z) } *crLine = 0; return (z); }
397 #define crFinishV } *crLine = 0; return; }
398 #define crReturn(z) \
400 *crLine =__LINE__; return (z); case __LINE__:;\
404 *crLine=__LINE__; return; case __LINE__:;\
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))
411 typedef struct ssh_tag *Ssh;
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);
437 * Buffer management constants. There are several of these for
438 * various different purposes:
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
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.
453 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
457 #define SSH1_BUFFER_LIMIT 32768
458 #define SSH_MAX_BACKLOG 32768
459 #define OUR_V2_WINSIZE 16384
460 #define OUR_V2_MAXPKT 0x4000UL
462 /* Maximum length of passwords/passphrases (arbitrary) */
463 #define SSH_MAX_PASSWORD_LEN 100
465 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
467 const static struct ssh_mac *macs[] = {
468 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
470 const static struct ssh_mac *buggymacs[] = {
471 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
474 static void *ssh_comp_none_init(void)
478 static void ssh_comp_none_cleanup(void *handle)
481 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
482 unsigned char **outblock, int *outlen)
486 static int ssh_comp_none_disable(void *handle)
490 const static struct ssh_compress ssh_comp_none = {
492 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
493 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
494 ssh_comp_none_disable, NULL
496 extern const struct ssh_compress ssh_zlib;
497 const static struct ssh_compress *compressions[] = {
498 &ssh_zlib, &ssh_comp_none
501 enum { /* channel types */
506 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
510 * 2-3-4 tree storing channels.
513 Ssh ssh; /* pointer back to main context */
514 unsigned remoteid, localid;
516 /* True if we opened this channel but server hasn't confirmed. */
519 * In SSH-1, this value contains four bits:
521 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
522 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
523 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
524 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
526 * A channel is completely finished with when all four bits are set.
530 struct ssh1_data_channel {
533 struct ssh2_data_channel {
535 unsigned remwindow, remmaxpkt;
540 struct ssh_agent_channel {
541 unsigned char *message;
542 unsigned char msglen[4];
543 unsigned lensofar, totallen;
545 struct ssh_x11_channel {
548 struct ssh_pfd_channel {
555 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
556 * use this structure in different ways, reflecting SSH-2's
557 * altogether saner approach to port forwarding.
559 * In SSH-1, you arrange a remote forwarding by sending the server
560 * the remote port number, and the local destination host:port.
561 * When a connection comes in, the server sends you back that
562 * host:port pair, and you connect to it. This is a ready-made
563 * security hole if you're not on the ball: a malicious server
564 * could send you back _any_ host:port pair, so if you trustingly
565 * connect to the address it gives you then you've just opened the
566 * entire inside of your corporate network just by connecting
567 * through it to a dodgy SSH server. Hence, we must store a list of
568 * host:port pairs we _are_ trying to forward to, and reject a
569 * connection request from the server if it's not in the list.
571 * In SSH-2, each side of the connection minds its own business and
572 * doesn't send unnecessary information to the other. You arrange a
573 * remote forwarding by sending the server just the remote port
574 * number. When a connection comes in, the server tells you which
575 * of its ports was connected to; and _you_ have to remember what
576 * local host:port pair went with that port number.
578 * Hence, in SSH-1 this structure is indexed by destination
579 * host:port pair, whereas in SSH-2 it is indexed by source port.
581 struct ssh_portfwd; /* forward declaration */
583 struct ssh_rportfwd {
584 unsigned sport, dport;
587 struct ssh_portfwd *pfrec;
589 #define free_rportfwd(pf) ( \
590 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
593 * Separately to the rportfwd tree (which is for looking up port
594 * open requests from the server), a tree of _these_ structures is
595 * used to keep track of all the currently open port forwardings,
596 * so that we can reconfigure in mid-session if the user requests
600 enum { DESTROY, KEEP, CREATE } status;
602 unsigned sport, dport;
605 struct ssh_rportfwd *remote;
609 #define free_portfwd(pf) ( \
610 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
611 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
614 long length; /* length of `data' actually used */
615 long forcepad; /* SSH-2: force padding to at least this length */
616 int type; /* only used for incoming packets */
617 unsigned long sequence; /* SSH-2 incoming sequence number */
618 unsigned char *data; /* allocated storage */
619 unsigned char *body; /* offset of payload within `data' */
620 long savedpos; /* temporary index into `data' (for strings) */
621 long maxlen; /* amount of storage allocated for `data' */
622 long encrypted_len; /* for SSH-2 total-size counting */
625 * State associated with packet logging
629 struct logblank_t *blanks;
632 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
633 struct Packet *pktin);
634 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
635 struct Packet *pktin);
636 static void ssh1_protocol_setup(Ssh ssh);
637 static void ssh2_protocol_setup(Ssh ssh);
638 static void ssh_size(void *handle, int width, int height);
639 static void ssh_special(void *handle, Telnet_Special);
640 static int ssh2_try_send(struct ssh_channel *c);
641 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
642 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
643 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
644 static int ssh_sendbuffer(void *handle);
645 static int ssh_do_close(Ssh ssh, int notify_exit);
646 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
647 static int ssh2_pkt_getbool(struct Packet *pkt);
648 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
649 static void ssh2_timer(void *ctx, long now);
650 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
651 struct Packet *pktin);
653 struct rdpkt1_state_tag {
654 long len, pad, biglen, to_read;
655 unsigned long realcrc, gotcrc;
659 struct Packet *pktin;
662 struct rdpkt2_state_tag {
663 long len, pad, payload, packetlen, maclen;
666 unsigned long incoming_sequence;
667 struct Packet *pktin;
670 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
671 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
673 struct queued_handler;
674 struct queued_handler {
676 chandler_fn_t handler;
678 struct queued_handler *next;
682 const struct plug_function_table *fn;
683 /* the above field _must_ be first in the structure */
693 unsigned char session_key[32];
695 int v1_remote_protoflags;
696 int v1_local_protoflags;
697 int agentfwd_enabled;
700 const struct ssh_cipher *cipher;
703 const struct ssh2_cipher *cscipher, *sccipher;
704 void *cs_cipher_ctx, *sc_cipher_ctx;
705 const struct ssh_mac *csmac, *scmac;
706 void *cs_mac_ctx, *sc_mac_ctx;
707 const struct ssh_compress *cscomp, *sccomp;
708 void *cs_comp_ctx, *sc_comp_ctx;
709 const struct ssh_kex *kex;
710 const struct ssh_signkey *hostkey;
711 unsigned char v2_session_id[32];
712 int v2_session_id_len;
718 int echoing, editing;
722 int ospeed, ispeed; /* temporaries */
723 int term_width, term_height;
725 tree234 *channels; /* indexed by local id */
726 struct ssh_channel *mainchan; /* primary session channel */
731 tree234 *rportfwds, *portfwds;
735 SSH_STATE_BEFORE_SIZE,
741 int size_needed, eof_needed;
743 struct Packet **queue;
744 int queuelen, queuesize;
746 unsigned char *deferred_send_data;
747 int deferred_len, deferred_size;
750 * Gross hack: pscp will try to start SFTP but fall back to
751 * scp1 if that fails. This variable is the means by which
752 * scp.c can reach into the SSH code and find out which one it
757 bufchain banner; /* accumulates banners during do_ssh2_authconn */
764 int v1_throttle_count;
767 int v1_stdout_throttling;
768 unsigned long v2_outgoing_sequence;
770 int ssh1_rdpkt_crstate;
771 int ssh2_rdpkt_crstate;
772 int do_ssh_init_crstate;
773 int ssh_gotdata_crstate;
774 int do_ssh1_login_crstate;
775 int do_ssh1_connection_crstate;
776 int do_ssh2_transport_crstate;
777 int do_ssh2_authconn_crstate;
779 void *do_ssh_init_state;
780 void *do_ssh1_login_state;
781 void *do_ssh2_transport_state;
782 void *do_ssh2_authconn_state;
784 struct rdpkt1_state_tag rdpkt1_state;
785 struct rdpkt2_state_tag rdpkt2_state;
787 /* SSH-1 and SSH-2 use this for different things, but both use it */
788 int protocol_initial_phase_done;
790 void (*protocol) (Ssh ssh, void *vin, int inlen,
792 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
795 * We maintain a full _copy_ of a Config structure here, not
796 * merely a pointer to it. That way, when we're passed a new
797 * one for reconfiguration, we can check the differences and
798 * potentially reconfigure port forwardings etc in mid-session.
803 * Used to transfer data back from async callbacks.
805 void *agent_response;
806 int agent_response_len;
810 * The SSH connection can be set as `frozen', meaning we are
811 * not currently accepting incoming data from the network. This
812 * is slightly more serious than setting the _socket_ as
813 * frozen, because we may already have had data passed to us
814 * from the network which we need to delay processing until
815 * after the freeze is lifted, so we also need a bufchain to
819 bufchain queued_incoming_data;
822 * Dispatch table for packet types that we may have to deal
825 handler_fn_t packet_dispatch[256];
828 * Queues of one-off handler functions for success/failure
829 * indications from a request.
831 struct queued_handler *qhead, *qtail;
834 * This module deals with sending keepalives.
839 * Track incoming and outgoing data sizes and time, for
842 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
843 unsigned long max_data_size;
845 long next_rekey, last_rekey;
846 char *deferred_rekey_reason; /* points to STATIC string; don't free */
849 #define logevent(s) logevent(ssh->frontend, s)
851 /* logevent, only printf-formatted. */
852 static void logeventf(Ssh ssh, const char *fmt, ...)
858 buf = dupvprintf(fmt, ap);
864 #define bombout(msg) \
866 char *text = dupprintf msg; \
867 ssh_do_close(ssh, FALSE); \
869 connection_fatal(ssh->frontend, "%s", text); \
873 /* Functions to leave bits out of the SSH packet log file. */
875 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
877 if (ssh->cfg.logomitpass)
878 pkt->logmode = blanktype;
881 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
883 if (ssh->cfg.logomitdata)
884 pkt->logmode = blanktype;
887 static void end_log_omission(Ssh ssh, struct Packet *pkt)
889 pkt->logmode = PKTLOG_EMIT;
892 /* Helper function for common bits of parsing cfg.ttymodes. */
893 static void parse_ttymodes(Ssh ssh, char *modes,
894 void (*do_mode)(void *data, char *mode, char *val),
898 char *t = strchr(modes, '\t');
899 char *m = snewn(t-modes+1, char);
901 strncpy(m, modes, t-modes);
904 val = get_ttymode(ssh->frontend, m);
908 do_mode(data, m, val);
911 modes += strlen(modes) + 1;
915 static int ssh_channelcmp(void *av, void *bv)
917 struct ssh_channel *a = (struct ssh_channel *) av;
918 struct ssh_channel *b = (struct ssh_channel *) bv;
919 if (a->localid < b->localid)
921 if (a->localid > b->localid)
925 static int ssh_channelfind(void *av, void *bv)
927 unsigned *a = (unsigned *) av;
928 struct ssh_channel *b = (struct ssh_channel *) bv;
936 static int ssh_rportcmp_ssh1(void *av, void *bv)
938 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
939 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
941 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
942 return i < 0 ? -1 : +1;
943 if (a->dport > b->dport)
945 if (a->dport < b->dport)
950 static int ssh_rportcmp_ssh2(void *av, void *bv)
952 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
953 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
955 if (a->sport > b->sport)
957 if (a->sport < b->sport)
963 * Special form of strcmp which can cope with NULL inputs. NULL is
964 * defined to sort before even the empty string.
966 static int nullstrcmp(const char *a, const char *b)
968 if (a == NULL && b == NULL)
977 static int ssh_portcmp(void *av, void *bv)
979 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
980 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
982 if (a->type > b->type)
984 if (a->type < b->type)
986 if (a->addressfamily > b->addressfamily)
988 if (a->addressfamily < b->addressfamily)
990 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
991 return i < 0 ? -1 : +1;
992 if (a->sport > b->sport)
994 if (a->sport < b->sport)
996 if (a->type != 'D') {
997 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
998 return i < 0 ? -1 : +1;
999 if (a->dport > b->dport)
1001 if (a->dport < b->dport)
1007 static int alloc_channel_id(Ssh ssh)
1009 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1010 unsigned low, high, mid;
1012 struct ssh_channel *c;
1015 * First-fit allocation of channel numbers: always pick the
1016 * lowest unused one. To do this, binary-search using the
1017 * counted B-tree to find the largest channel ID which is in a
1018 * contiguous sequence from the beginning. (Precisely
1019 * everything in that sequence must have ID equal to its tree
1020 * index plus CHANNEL_NUMBER_OFFSET.)
1022 tsize = count234(ssh->channels);
1026 while (high - low > 1) {
1027 mid = (high + low) / 2;
1028 c = index234(ssh->channels, mid);
1029 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1030 low = mid; /* this one is fine */
1032 high = mid; /* this one is past it */
1035 * Now low points to either -1, or the tree index of the
1036 * largest ID in the initial sequence.
1039 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1040 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1042 return low + 1 + CHANNEL_NUMBER_OFFSET;
1045 static void c_write_stderr(int trusted, const char *buf, int len)
1048 for (i = 0; i < len; i++)
1049 if (buf[i] != '\r' && (trusted || buf[i] & 0x60))
1050 fputc(buf[i], stderr);
1053 static void c_write(Ssh ssh, const char *buf, int len)
1055 if (flags & FLAG_STDERR)
1056 c_write_stderr(1, buf, len);
1058 from_backend(ssh->frontend, 1, buf, len);
1061 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1063 if (flags & FLAG_STDERR)
1064 c_write_stderr(0, buf, len);
1066 from_backend_untrusted(ssh->frontend, buf, len);
1069 static void c_write_str(Ssh ssh, const char *buf)
1071 c_write(ssh, buf, strlen(buf));
1074 static void ssh_free_packet(struct Packet *pkt)
1079 static struct Packet *ssh_new_packet(void)
1081 struct Packet *pkt = snew(struct Packet);
1083 pkt->body = pkt->data = NULL;
1085 pkt->logmode = PKTLOG_EMIT;
1093 * Collect incoming data in the incoming packet buffer.
1094 * Decipher and verify the packet when it is completely read.
1095 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1096 * Update the *data and *datalen variables.
1097 * Return a Packet structure when a packet is completed.
1099 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1101 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1103 crBegin(ssh->ssh1_rdpkt_crstate);
1105 st->pktin = ssh_new_packet();
1107 st->pktin->type = 0;
1108 st->pktin->length = 0;
1110 for (st->i = st->len = 0; st->i < 4; st->i++) {
1111 while ((*datalen) == 0)
1113 st->len = (st->len << 8) + **data;
1114 (*data)++, (*datalen)--;
1117 st->pad = 8 - (st->len % 8);
1118 st->biglen = st->len + st->pad;
1119 st->pktin->length = st->len - 5;
1121 if (st->biglen < 0) {
1122 bombout(("Extremely large packet length from server suggests"
1123 " data stream corruption"));
1124 ssh_free_packet(st->pktin);
1128 st->pktin->maxlen = st->biglen;
1129 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1131 st->to_read = st->biglen;
1132 st->p = st->pktin->data;
1133 while (st->to_read > 0) {
1134 st->chunk = st->to_read;
1135 while ((*datalen) == 0)
1137 if (st->chunk > (*datalen))
1138 st->chunk = (*datalen);
1139 memcpy(st->p, *data, st->chunk);
1141 *datalen -= st->chunk;
1143 st->to_read -= st->chunk;
1146 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1147 st->biglen, NULL)) {
1148 bombout(("Network attack (CRC compensation) detected!"));
1149 ssh_free_packet(st->pktin);
1154 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1156 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1157 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1158 if (st->gotcrc != st->realcrc) {
1159 bombout(("Incorrect CRC received on packet"));
1160 ssh_free_packet(st->pktin);
1164 st->pktin->body = st->pktin->data + st->pad + 1;
1165 st->pktin->savedpos = 0;
1167 if (ssh->v1_compressing) {
1168 unsigned char *decompblk;
1170 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1171 st->pktin->body - 1, st->pktin->length + 1,
1172 &decompblk, &decomplen)) {
1173 bombout(("Zlib decompression encountered invalid data"));
1174 ssh_free_packet(st->pktin);
1178 if (st->pktin->maxlen < st->pad + decomplen) {
1179 st->pktin->maxlen = st->pad + decomplen;
1180 st->pktin->data = sresize(st->pktin->data,
1181 st->pktin->maxlen + APIEXTRA,
1183 st->pktin->body = st->pktin->data + st->pad + 1;
1186 memcpy(st->pktin->body - 1, decompblk, decomplen);
1188 st->pktin->length = decomplen - 1;
1191 st->pktin->type = st->pktin->body[-1];
1194 * Log incoming packet, possibly omitting sensitive fields.
1198 struct logblank_t blank;
1199 if (ssh->cfg.logomitdata) {
1200 int do_blank = FALSE, blank_prefix = 0;
1201 /* "Session data" packets - omit the data field */
1202 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1203 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1204 do_blank = TRUE; blank_prefix = 0;
1205 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1206 do_blank = TRUE; blank_prefix = 4;
1209 blank.offset = blank_prefix;
1210 blank.len = st->pktin->length;
1211 blank.type = PKTLOG_OMIT;
1215 log_packet(ssh->logctx,
1216 PKT_INCOMING, st->pktin->type,
1217 ssh1_pkt_type(st->pktin->type),
1218 st->pktin->body, st->pktin->length,
1222 crFinish(st->pktin);
1225 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1227 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1229 crBegin(ssh->ssh2_rdpkt_crstate);
1231 st->pktin = ssh_new_packet();
1233 st->pktin->type = 0;
1234 st->pktin->length = 0;
1236 st->cipherblk = ssh->sccipher->blksize;
1239 if (st->cipherblk < 8)
1242 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1245 * Acquire and decrypt the first block of the packet. This will
1246 * contain the length and padding details.
1248 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1249 while ((*datalen) == 0)
1251 st->pktin->data[st->i] = *(*data)++;
1256 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1257 st->pktin->data, st->cipherblk);
1260 * Now get the length and padding figures.
1262 st->len = GET_32BIT(st->pktin->data);
1263 st->pad = st->pktin->data[4];
1266 * _Completely_ silly lengths should be stomped on before they
1267 * do us any more damage.
1269 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1270 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
1271 bombout(("Incoming packet was garbled on decryption"));
1272 ssh_free_packet(st->pktin);
1277 * This enables us to deduce the payload length.
1279 st->payload = st->len - st->pad - 1;
1281 st->pktin->length = st->payload + 5;
1284 * So now we can work out the total packet length.
1286 st->packetlen = st->len + 4;
1287 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1290 * Allocate memory for the rest of the packet.
1292 st->pktin->maxlen = st->packetlen + st->maclen;
1293 st->pktin->data = sresize(st->pktin->data,
1294 st->pktin->maxlen + APIEXTRA,
1298 * Read and decrypt the remainder of the packet.
1300 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1302 while ((*datalen) == 0)
1304 st->pktin->data[st->i] = *(*data)++;
1307 /* Decrypt everything _except_ the MAC. */
1309 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1310 st->pktin->data + st->cipherblk,
1311 st->packetlen - st->cipherblk);
1313 st->pktin->encrypted_len = st->packetlen;
1319 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1320 st->incoming_sequence)) {
1321 bombout(("Incorrect MAC received on packet"));
1322 ssh_free_packet(st->pktin);
1326 st->pktin->sequence = st->incoming_sequence++;
1329 * Decompress packet payload.
1332 unsigned char *newpayload;
1335 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1336 st->pktin->data + 5, st->pktin->length - 5,
1337 &newpayload, &newlen)) {
1338 if (st->pktin->maxlen < newlen + 5) {
1339 st->pktin->maxlen = newlen + 5;
1340 st->pktin->data = sresize(st->pktin->data,
1341 st->pktin->maxlen + APIEXTRA,
1344 st->pktin->length = 5 + newlen;
1345 memcpy(st->pktin->data + 5, newpayload, newlen);
1350 st->pktin->savedpos = 6;
1351 st->pktin->body = st->pktin->data;
1352 st->pktin->type = st->pktin->data[5];
1355 * Log incoming packet, possibly omitting sensitive fields.
1359 struct logblank_t blank;
1360 if (ssh->cfg.logomitdata) {
1361 int do_blank = FALSE, blank_prefix = 0;
1362 /* "Session data" packets - omit the data field */
1363 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1364 do_blank = TRUE; blank_prefix = 4;
1365 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1366 do_blank = TRUE; blank_prefix = 8;
1369 blank.offset = blank_prefix;
1370 blank.len = (st->pktin->length-6) - blank_prefix;
1371 blank.type = PKTLOG_OMIT;
1375 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1376 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1377 st->pktin->data+6, st->pktin->length-6,
1381 crFinish(st->pktin);
1384 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1386 int pad, biglen, i, pktoffs;
1390 * XXX various versions of SC (including 8.8.4) screw up the
1391 * register allocation in this function and use the same register
1392 * (D6) for len and as a temporary, with predictable results. The
1393 * following sledgehammer prevents this.
1400 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1401 ssh1_pkt_type(pkt->data[12]),
1402 pkt->body, pkt->length - (pkt->body - pkt->data),
1403 pkt->nblanks, pkt->blanks);
1404 sfree(pkt->blanks); pkt->blanks = NULL;
1407 if (ssh->v1_compressing) {
1408 unsigned char *compblk;
1410 zlib_compress_block(ssh->cs_comp_ctx,
1411 pkt->data + 12, pkt->length - 12,
1412 &compblk, &complen);
1413 memcpy(pkt->data + 12, compblk, complen);
1415 pkt->length = complen + 12;
1418 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1420 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1421 pad = 8 - (len % 8);
1423 biglen = len + pad; /* len(padding+type+data+CRC) */
1425 for (i = pktoffs; i < 4+8; i++)
1426 pkt->data[i] = random_byte();
1427 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1428 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1429 PUT_32BIT(pkt->data + pktoffs, len);
1432 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1433 pkt->data + pktoffs + 4, biglen);
1435 if (offset_p) *offset_p = pktoffs;
1436 return biglen + 4; /* len(length+padding+type+data+CRC) */
1439 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1441 int len, backlog, offset;
1442 len = s_wrpkt_prepare(ssh, pkt, &offset);
1443 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1444 if (backlog > SSH_MAX_BACKLOG)
1445 ssh_throttle_all(ssh, 1, backlog);
1446 ssh_free_packet(pkt);
1449 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1452 len = s_wrpkt_prepare(ssh, pkt, &offset);
1453 if (ssh->deferred_len + len > ssh->deferred_size) {
1454 ssh->deferred_size = ssh->deferred_len + len + 128;
1455 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1459 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1460 pkt->data + offset, len);
1461 ssh->deferred_len += len;
1462 ssh_free_packet(pkt);
1466 * Construct a SSH-1 packet with the specified contents.
1467 * (This all-at-once interface used to be the only one, but now SSH-1
1468 * packets can also be constructed incrementally.)
1470 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1476 pkt = ssh1_pkt_init(pkttype);
1478 while ((argtype = va_arg(ap, int)) != PKT_END) {
1479 unsigned char *argp, argchar;
1480 unsigned long argint;
1483 /* Actual fields in the packet */
1485 argint = va_arg(ap, int);
1486 ssh_pkt_adduint32(pkt, argint);
1489 argchar = (unsigned char) va_arg(ap, int);
1490 ssh_pkt_addbyte(pkt, argchar);
1493 argp = va_arg(ap, unsigned char *);
1494 arglen = va_arg(ap, int);
1495 ssh_pkt_adddata(pkt, argp, arglen);
1498 argp = va_arg(ap, unsigned char *);
1499 ssh_pkt_addstring(pkt, argp);
1502 bn = va_arg(ap, Bignum);
1503 ssh1_pkt_addmp(pkt, bn);
1505 /* Tokens for modifications to packet logging */
1507 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1510 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1513 end_log_omission(ssh, pkt);
1521 static void send_packet(Ssh ssh, int pkttype, ...)
1525 va_start(ap, pkttype);
1526 pkt = construct_packet(ssh, pkttype, ap);
1531 static void defer_packet(Ssh ssh, int pkttype, ...)
1535 va_start(ap, pkttype);
1536 pkt = construct_packet(ssh, pkttype, ap);
1538 s_wrpkt_defer(ssh, pkt);
1541 static int ssh_versioncmp(char *a, char *b)
1544 unsigned long av, bv;
1546 av = strtoul(a, &ae, 10);
1547 bv = strtoul(b, &be, 10);
1549 return (av < bv ? -1 : +1);
1554 av = strtoul(ae, &ae, 10);
1555 bv = strtoul(be, &be, 10);
1557 return (av < bv ? -1 : +1);
1562 * Utility routines for putting an SSH-protocol `string' and
1563 * `uint32' into a hash state.
1565 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1567 unsigned char lenblk[4];
1568 PUT_32BIT(lenblk, len);
1569 h->bytes(s, lenblk, 4);
1570 h->bytes(s, str, len);
1573 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1575 unsigned char intblk[4];
1576 PUT_32BIT(intblk, i);
1577 h->bytes(s, intblk, 4);
1581 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1583 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1585 if (pkt->maxlen < length) {
1586 unsigned char *body = pkt->body;
1587 int offset = body ? body - pkt->data : 0;
1588 pkt->maxlen = length + 256;
1589 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1590 if (body) pkt->body = pkt->data + offset;
1593 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1595 if (pkt->logmode != PKTLOG_EMIT) {
1597 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1599 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1600 (pkt->body - pkt->data);
1601 pkt->blanks[pkt->nblanks-1].len = len;
1602 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1605 ssh_pkt_ensure(pkt, pkt->length);
1606 memcpy(pkt->data + pkt->length - len, data, len);
1608 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1610 ssh_pkt_adddata(pkt, &byte, 1);
1612 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1614 ssh_pkt_adddata(pkt, &value, 1);
1616 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1619 PUT_32BIT(x, value);
1620 ssh_pkt_adddata(pkt, x, 4);
1622 static void ssh_pkt_addstring_start(struct Packet *pkt)
1624 ssh_pkt_adduint32(pkt, 0);
1625 pkt->savedpos = pkt->length;
1627 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1629 ssh_pkt_adddata(pkt, data, strlen(data));
1630 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1632 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1634 ssh_pkt_adddata(pkt, data, len);
1635 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1637 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1639 ssh_pkt_addstring_start(pkt);
1640 ssh_pkt_addstring_str(pkt, data);
1642 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1644 int len = ssh1_bignum_length(b);
1645 unsigned char *data = snewn(len, char);
1646 (void) ssh1_write_bignum(data, b);
1647 ssh_pkt_adddata(pkt, data, len);
1650 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1653 int i, n = (bignum_bitcount(b) + 7) / 8;
1654 p = snewn(n + 1, unsigned char);
1656 for (i = 1; i <= n; i++)
1657 p[i] = bignum_byte(b, n - i);
1659 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1661 memmove(p, p + i, n + 1 - i);
1665 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1669 p = ssh2_mpint_fmt(b, &len);
1670 ssh_pkt_addstring_start(pkt);
1671 ssh_pkt_addstring_data(pkt, (char *)p, len);
1675 static struct Packet *ssh1_pkt_init(int pkt_type)
1677 struct Packet *pkt = ssh_new_packet();
1678 pkt->length = 4 + 8; /* space for length + max padding */
1679 ssh_pkt_addbyte(pkt, pkt_type);
1680 pkt->body = pkt->data + pkt->length;
1684 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1685 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1686 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1687 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1688 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1689 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1690 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1691 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1692 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1694 static struct Packet *ssh2_pkt_init(int pkt_type)
1696 struct Packet *pkt = ssh_new_packet();
1697 pkt->length = 5; /* space for packet length + padding length */
1699 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1700 pkt->body = pkt->data + pkt->length; /* after packet type */
1705 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1706 * put the MAC on it. Final packet, ready to be sent, is stored in
1707 * pkt->data. Total length is returned.
1709 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1711 int cipherblk, maclen, padding, i;
1714 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1715 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1716 pkt->body, pkt->length - (pkt->body - pkt->data),
1717 pkt->nblanks, pkt->blanks);
1718 sfree(pkt->blanks); pkt->blanks = NULL;
1722 * Compress packet payload.
1725 unsigned char *newpayload;
1728 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1730 &newpayload, &newlen)) {
1732 ssh2_pkt_adddata(pkt, newpayload, newlen);
1738 * Add padding. At least four bytes, and must also bring total
1739 * length (minus MAC) up to a multiple of the block size.
1740 * If pkt->forcepad is set, make sure the packet is at least that size
1743 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1744 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1746 if (pkt->length + padding < pkt->forcepad)
1747 padding = pkt->forcepad - pkt->length;
1749 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1750 assert(padding <= 255);
1751 maclen = ssh->csmac ? ssh->csmac->len : 0;
1752 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1753 pkt->data[4] = padding;
1754 for (i = 0; i < padding; i++)
1755 pkt->data[pkt->length + i] = random_byte();
1756 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1758 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1759 pkt->length + padding,
1760 ssh->v2_outgoing_sequence);
1761 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1764 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1765 pkt->data, pkt->length + padding);
1767 pkt->encrypted_len = pkt->length + padding;
1769 /* Ready-to-send packet starts at pkt->data. We return length. */
1770 return pkt->length + padding + maclen;
1774 * Routines called from the main SSH code to send packets. There
1775 * are quite a few of these, because we have two separate
1776 * mechanisms for delaying the sending of packets:
1778 * - In order to send an IGNORE message and a password message in
1779 * a single fixed-length blob, we require the ability to
1780 * concatenate the encrypted forms of those two packets _into_ a
1781 * single blob and then pass it to our <network.h> transport
1782 * layer in one go. Hence, there's a deferment mechanism which
1783 * works after packet encryption.
1785 * - In order to avoid sending any connection-layer messages
1786 * during repeat key exchange, we have to queue up any such
1787 * outgoing messages _before_ they are encrypted (and in
1788 * particular before they're allocated sequence numbers), and
1789 * then send them once we've finished.
1791 * I call these mechanisms `defer' and `queue' respectively, so as
1792 * to distinguish them reasonably easily.
1794 * The functions send_noqueue() and defer_noqueue() free the packet
1795 * structure they are passed. Every outgoing packet goes through
1796 * precisely one of these functions in its life; packets passed to
1797 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1798 * these or get queued, and then when the queue is later emptied
1799 * the packets are all passed to defer_noqueue().
1801 * When using a CBC-mode cipher, it's necessary to ensure that an
1802 * attacker can't provide data to be encrypted using an IV that they
1803 * know. We ensure this by prefixing each packet that might contain
1804 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1805 * mechanism, so in this case send_noqueue() ends up redirecting to
1806 * defer_noqueue(). If you don't like this inefficiency, don't use
1810 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1811 static void ssh_pkt_defersend(Ssh);
1814 * Send an SSH-2 packet immediately, without queuing or deferring.
1816 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1820 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1821 /* We need to send two packets, so use the deferral mechanism. */
1822 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1823 ssh_pkt_defersend(ssh);
1826 len = ssh2_pkt_construct(ssh, pkt);
1827 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1828 if (backlog > SSH_MAX_BACKLOG)
1829 ssh_throttle_all(ssh, 1, backlog);
1831 ssh->outgoing_data_size += pkt->encrypted_len;
1832 if (!ssh->kex_in_progress &&
1833 ssh->max_data_size != 0 &&
1834 ssh->outgoing_data_size > ssh->max_data_size)
1835 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1837 ssh_free_packet(pkt);
1841 * Defer an SSH-2 packet.
1843 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1846 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1847 ssh->deferred_len == 0 && !noignore) {
1849 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1850 * get encrypted with a known IV.
1852 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1853 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1855 len = ssh2_pkt_construct(ssh, pkt);
1856 if (ssh->deferred_len + len > ssh->deferred_size) {
1857 ssh->deferred_size = ssh->deferred_len + len + 128;
1858 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1862 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1863 ssh->deferred_len += len;
1864 ssh->deferred_data_size += pkt->encrypted_len;
1865 ssh_free_packet(pkt);
1869 * Queue an SSH-2 packet.
1871 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1873 assert(ssh->queueing);
1875 if (ssh->queuelen >= ssh->queuesize) {
1876 ssh->queuesize = ssh->queuelen + 32;
1877 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1880 ssh->queue[ssh->queuelen++] = pkt;
1884 * Either queue or send a packet, depending on whether queueing is
1887 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1890 ssh2_pkt_queue(ssh, pkt);
1892 ssh2_pkt_send_noqueue(ssh, pkt);
1897 * Either queue or defer a packet, depending on whether queueing is
1900 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1903 ssh2_pkt_queue(ssh, pkt);
1905 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1910 * Send the whole deferred data block constructed by
1911 * ssh2_pkt_defer() or SSH-1's defer_packet().
1913 * The expected use of the defer mechanism is that you call
1914 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1915 * not currently queueing, this simply sets up deferred_send_data
1916 * and then sends it. If we _are_ currently queueing, the calls to
1917 * ssh2_pkt_defer() put the deferred packets on to the queue
1918 * instead, and therefore ssh_pkt_defersend() has no deferred data
1919 * to send. Hence, there's no need to make it conditional on
1922 static void ssh_pkt_defersend(Ssh ssh)
1925 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1927 ssh->deferred_len = ssh->deferred_size = 0;
1928 sfree(ssh->deferred_send_data);
1929 ssh->deferred_send_data = NULL;
1930 if (backlog > SSH_MAX_BACKLOG)
1931 ssh_throttle_all(ssh, 1, backlog);
1933 ssh->outgoing_data_size += ssh->deferred_data_size;
1934 if (!ssh->kex_in_progress &&
1935 ssh->max_data_size != 0 &&
1936 ssh->outgoing_data_size > ssh->max_data_size)
1937 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1938 ssh->deferred_data_size = 0;
1942 * Send all queued SSH-2 packets. We send them by means of
1943 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1944 * packets that needed to be lumped together.
1946 static void ssh2_pkt_queuesend(Ssh ssh)
1950 assert(!ssh->queueing);
1952 for (i = 0; i < ssh->queuelen; i++)
1953 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
1956 ssh_pkt_defersend(ssh);
1960 void bndebug(char *string, Bignum b)
1964 p = ssh2_mpint_fmt(b, &len);
1965 debug(("%s", string));
1966 for (i = 0; i < len; i++)
1967 debug((" %02x", p[i]));
1973 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
1977 p = ssh2_mpint_fmt(b, &len);
1978 hash_string(h, s, p, len);
1983 * Packet decode functions for both SSH-1 and SSH-2.
1985 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1987 unsigned long value;
1988 if (pkt->length - pkt->savedpos < 4)
1989 return 0; /* arrgh, no way to decline (FIXME?) */
1990 value = GET_32BIT(pkt->body + pkt->savedpos);
1994 static int ssh2_pkt_getbool(struct Packet *pkt)
1996 unsigned long value;
1997 if (pkt->length - pkt->savedpos < 1)
1998 return 0; /* arrgh, no way to decline (FIXME?) */
1999 value = pkt->body[pkt->savedpos] != 0;
2003 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2008 if (pkt->length - pkt->savedpos < 4)
2010 len = GET_32BIT(pkt->body + pkt->savedpos);
2015 if (pkt->length - pkt->savedpos < *length)
2017 *p = (char *)(pkt->body + pkt->savedpos);
2018 pkt->savedpos += *length;
2020 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2022 if (pkt->length - pkt->savedpos < length)
2024 pkt->savedpos += length;
2025 return pkt->body + (pkt->savedpos - length);
2027 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2028 unsigned char **keystr)
2032 j = makekey(pkt->body + pkt->savedpos,
2033 pkt->length - pkt->savedpos,
2040 assert(pkt->savedpos < pkt->length);
2044 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2049 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2050 pkt->length - pkt->savedpos, &b);
2058 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2064 ssh_pkt_getstring(pkt, &p, &length);
2069 b = bignum_from_bytes((unsigned char *)p, length);
2074 * Helper function to add an SSH-2 signature blob to a packet.
2075 * Expects to be shown the public key blob as well as the signature
2076 * blob. Normally works just like ssh2_pkt_addstring, but will
2077 * fiddle with the signature packet if necessary for
2078 * BUG_SSH2_RSA_PADDING.
2080 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2081 void *pkblob_v, int pkblob_len,
2082 void *sigblob_v, int sigblob_len)
2084 unsigned char *pkblob = (unsigned char *)pkblob_v;
2085 unsigned char *sigblob = (unsigned char *)sigblob_v;
2087 /* dmemdump(pkblob, pkblob_len); */
2088 /* dmemdump(sigblob, sigblob_len); */
2091 * See if this is in fact an ssh-rsa signature and a buggy
2092 * server; otherwise we can just do this the easy way.
2094 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2095 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2096 int pos, len, siglen;
2099 * Find the byte length of the modulus.
2102 pos = 4+7; /* skip over "ssh-rsa" */
2103 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2104 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2105 pos += 4; /* find modulus itself */
2106 while (len > 0 && pkblob[pos] == 0)
2108 /* debug(("modulus length is %d\n", len)); */
2111 * Now find the signature integer.
2113 pos = 4+7; /* skip over "ssh-rsa" */
2114 siglen = GET_32BIT(sigblob+pos);
2115 /* debug(("signature length is %d\n", siglen)); */
2117 if (len != siglen) {
2118 unsigned char newlen[4];
2119 ssh2_pkt_addstring_start(pkt);
2120 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2121 /* dmemdump(sigblob, pos); */
2122 pos += 4; /* point to start of actual sig */
2123 PUT_32BIT(newlen, len);
2124 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2125 /* dmemdump(newlen, 4); */
2127 while (len-- > siglen) {
2128 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2129 /* dmemdump(newlen, 1); */
2131 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2132 /* dmemdump(sigblob+pos, siglen); */
2136 /* Otherwise fall through and do it the easy way. */
2139 ssh2_pkt_addstring_start(pkt);
2140 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2144 * Examine the remote side's version string and compare it against
2145 * a list of known buggy implementations.
2147 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2149 char *imp; /* pointer to implementation part */
2151 imp += strcspn(imp, "-");
2153 imp += strcspn(imp, "-");
2156 ssh->remote_bugs = 0;
2158 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2159 (ssh->cfg.sshbug_ignore1 == AUTO &&
2160 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2161 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2162 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2163 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2165 * These versions don't support SSH1_MSG_IGNORE, so we have
2166 * to use a different defence against password length
2169 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2170 logevent("We believe remote version has SSH-1 ignore bug");
2173 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2174 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2175 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2177 * These versions need a plain password sent; they can't
2178 * handle having a null and a random length of data after
2181 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2182 logevent("We believe remote version needs a plain SSH-1 password");
2185 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2186 (ssh->cfg.sshbug_rsa1 == AUTO &&
2187 (!strcmp(imp, "Cisco-1.25")))) {
2189 * These versions apparently have no clue whatever about
2190 * RSA authentication and will panic and die if they see
2191 * an AUTH_RSA message.
2193 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2194 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2197 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2198 (ssh->cfg.sshbug_hmac2 == AUTO &&
2199 !wc_match("* VShell", imp) &&
2200 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2201 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2202 wc_match("2.1 *", imp)))) {
2204 * These versions have the HMAC bug.
2206 ssh->remote_bugs |= BUG_SSH2_HMAC;
2207 logevent("We believe remote version has SSH-2 HMAC bug");
2210 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2211 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2212 !wc_match("* VShell", imp) &&
2213 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2215 * These versions have the key-derivation bug (failing to
2216 * include the literal shared secret in the hashes that
2217 * generate the keys).
2219 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2220 logevent("We believe remote version has SSH-2 key-derivation bug");
2223 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2224 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2225 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2226 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2228 * These versions have the SSH-2 RSA padding bug.
2230 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2231 logevent("We believe remote version has SSH-2 RSA padding bug");
2234 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2235 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2236 wc_match("OpenSSH_2.[0-2]*", imp))) {
2238 * These versions have the SSH-2 session-ID bug in
2239 * public-key authentication.
2241 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2242 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2245 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2246 (ssh->cfg.sshbug_rekey2 == AUTO &&
2247 (wc_match("DigiSSH_2.0", imp) ||
2248 wc_match("OpenSSH_2.[0-4]*", imp) ||
2249 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2250 wc_match("Sun_SSH_1.0", imp) ||
2251 wc_match("Sun_SSH_1.0.1", imp) ||
2252 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2253 wc_match("WeOnlyDo-*", imp)))) {
2255 * These versions have the SSH-2 rekey bug.
2257 ssh->remote_bugs |= BUG_SSH2_REKEY;
2258 logevent("We believe remote version has SSH-2 rekey bug");
2263 * The `software version' part of an SSH version string is required
2264 * to contain no spaces or minus signs.
2266 static void ssh_fix_verstring(char *str)
2268 /* Eat "SSH-<protoversion>-". */
2269 assert(*str == 'S'); str++;
2270 assert(*str == 'S'); str++;
2271 assert(*str == 'H'); str++;
2272 assert(*str == '-'); str++;
2273 while (*str && *str != '-') str++;
2274 assert(*str == '-'); str++;
2276 /* Convert minus signs and spaces in the remaining string into
2279 if (*str == '-' || *str == ' ')
2285 static int do_ssh_init(Ssh ssh, unsigned char c)
2287 struct do_ssh_init_state {
2295 crState(do_ssh_init_state);
2297 crBegin(ssh->do_ssh_init_crstate);
2299 /* Search for a line beginning with the string "SSH-" in the input. */
2301 if (c != 'S') goto no;
2303 if (c != 'S') goto no;
2305 if (c != 'H') goto no;
2307 if (c != '-') goto no;
2316 s->vstring = snewn(s->vstrsize, char);
2317 strcpy(s->vstring, "SSH-");
2321 crReturn(1); /* get another char */
2322 if (s->vslen >= s->vstrsize - 1) {
2324 s->vstring = sresize(s->vstring, s->vstrsize, char);
2326 s->vstring[s->vslen++] = c;
2329 s->version[s->i] = '\0';
2331 } else if (s->i < sizeof(s->version) - 1)
2332 s->version[s->i++] = c;
2333 } else if (c == '\012')
2337 ssh->agentfwd_enabled = FALSE;
2338 ssh->rdpkt2_state.incoming_sequence = 0;
2340 s->vstring[s->vslen] = 0;
2341 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2342 logeventf(ssh, "Server version: %s", s->vstring);
2343 ssh_detect_bugs(ssh, s->vstring);
2346 * Decide which SSH protocol version to support.
2349 /* Anything strictly below "2.0" means protocol 1 is supported. */
2350 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2351 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2352 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2354 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2355 bombout(("SSH protocol version 1 required by user but not provided by server"));
2358 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2359 bombout(("SSH protocol version 2 required by user but not provided by server"));
2366 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2368 * Construct a v2 version string.
2370 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2374 * Construct a v1 version string.
2376 verstring = dupprintf("SSH-%s-%s\012",
2377 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2378 s->version : "1.5"),
2383 ssh_fix_verstring(verstring);
2385 if (ssh->version == 2) {
2388 * Hash our version string and their version string.
2390 len = strcspn(verstring, "\015\012");
2391 ssh->v_c = snewn(len + 1, char);
2392 memcpy(ssh->v_c, verstring, len);
2394 len = strcspn(s->vstring, "\015\012");
2395 ssh->v_s = snewn(len + 1, char);
2396 memcpy(ssh->v_s, s->vstring, len);
2400 * Initialise SSH-2 protocol.
2402 ssh->protocol = ssh2_protocol;
2403 ssh2_protocol_setup(ssh);
2404 ssh->s_rdpkt = ssh2_rdpkt;
2407 * Initialise SSH-1 protocol.
2409 ssh->protocol = ssh1_protocol;
2410 ssh1_protocol_setup(ssh);
2411 ssh->s_rdpkt = ssh1_rdpkt;
2413 logeventf(ssh, "We claim version: %.*s",
2414 strcspn(verstring, "\015\012"), verstring);
2415 sk_write(ssh->s, verstring, strlen(verstring));
2417 if (ssh->version == 2)
2418 do_ssh2_transport(ssh, NULL, -1, NULL);
2421 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2423 update_specials_menu(ssh->frontend);
2424 ssh->state = SSH_STATE_BEFORE_SIZE;
2425 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2432 static void ssh_process_incoming_data(Ssh ssh,
2433 unsigned char **data, int *datalen)
2435 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2437 ssh->protocol(ssh, NULL, 0, pktin);
2438 ssh_free_packet(pktin);
2442 static void ssh_queue_incoming_data(Ssh ssh,
2443 unsigned char **data, int *datalen)
2445 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2450 static void ssh_process_queued_incoming_data(Ssh ssh)
2453 unsigned char *data;
2456 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2457 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2461 while (!ssh->frozen && len > 0)
2462 ssh_process_incoming_data(ssh, &data, &len);
2465 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2469 static void ssh_set_frozen(Ssh ssh, int frozen)
2472 sk_set_frozen(ssh->s, frozen);
2473 ssh->frozen = frozen;
2476 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2478 crBegin(ssh->ssh_gotdata_crstate);
2481 * To begin with, feed the characters one by one to the
2482 * protocol initialisation / selection function do_ssh_init().
2483 * When that returns 0, we're done with the initial greeting
2484 * exchange and can move on to packet discipline.
2487 int ret; /* need not be kept across crReturn */
2489 crReturnV; /* more data please */
2490 ret = do_ssh_init(ssh, *data);
2498 * We emerge from that loop when the initial negotiation is
2499 * over and we have selected an s_rdpkt function. Now pass
2500 * everything to s_rdpkt, and then pass the resulting packets
2501 * to the proper protocol handler.
2505 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2507 ssh_queue_incoming_data(ssh, &data, &datalen);
2508 /* This uses up all data and cannot cause anything interesting
2509 * to happen; indeed, for anything to happen at all, we must
2510 * return, so break out. */
2512 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2513 /* This uses up some or all data, and may freeze the
2515 ssh_process_queued_incoming_data(ssh);
2517 /* This uses up some or all data, and may freeze the
2519 ssh_process_incoming_data(ssh, &data, &datalen);
2521 /* FIXME this is probably EBW. */
2522 if (ssh->state == SSH_STATE_CLOSED)
2525 /* We're out of data. Go and get some more. */
2531 static int ssh_do_close(Ssh ssh, int notify_exit)
2534 struct ssh_channel *c;
2536 ssh->state = SSH_STATE_CLOSED;
2537 expire_timer_context(ssh);
2542 notify_remote_exit(ssh->frontend);
2547 * Now we must shut down any port- and X-forwarded channels going
2548 * through this connection.
2550 if (ssh->channels) {
2551 while (NULL != (c = index234(ssh->channels, 0))) {
2554 x11_close(c->u.x11.s);
2557 pfd_close(c->u.pfd.s);
2560 del234(ssh->channels, c); /* moving next one to index 0 */
2561 if (ssh->version == 2)
2562 bufchain_clear(&c->v.v2.outbuffer);
2567 * Go through port-forwardings, and close any associated
2568 * listening sockets.
2570 if (ssh->portfwds) {
2571 struct ssh_portfwd *pf;
2572 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2573 /* Dispose of any listening socket. */
2575 pfd_terminate(pf->local);
2576 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2584 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2585 const char *error_msg, int error_code)
2587 Ssh ssh = (Ssh) plug;
2588 char addrbuf[256], *msg;
2590 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2593 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2595 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2601 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2604 Ssh ssh = (Ssh) plug;
2605 int need_notify = ssh_do_close(ssh, FALSE);
2608 if (!ssh->close_expected)
2609 error_msg = "Server unexpectedly closed network connection";
2611 error_msg = "Server closed network connection";
2615 notify_remote_exit(ssh->frontend);
2618 logevent(error_msg);
2619 if (!ssh->close_expected || !ssh->clean_exit)
2620 connection_fatal(ssh->frontend, "%s", error_msg);
2624 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2626 Ssh ssh = (Ssh) plug;
2627 ssh_gotdata(ssh, (unsigned char *)data, len);
2628 if (ssh->state == SSH_STATE_CLOSED) {
2629 ssh_do_close(ssh, TRUE);
2635 static void ssh_sent(Plug plug, int bufsize)
2637 Ssh ssh = (Ssh) plug;
2639 * If the send backlog on the SSH socket itself clears, we
2640 * should unthrottle the whole world if it was throttled.
2642 if (bufsize < SSH_MAX_BACKLOG)
2643 ssh_throttle_all(ssh, 0, bufsize);
2647 * Connect to specified host and port.
2648 * Returns an error message, or NULL on success.
2649 * Also places the canonical host name into `realhost'. It must be
2650 * freed by the caller.
2652 static const char *connect_to_host(Ssh ssh, char *host, int port,
2653 char **realhost, int nodelay, int keepalive)
2655 static const struct plug_function_table fn_table = {
2666 ssh->savedhost = snewn(1 + strlen(host), char);
2667 strcpy(ssh->savedhost, host);
2670 port = 22; /* default ssh port */
2671 ssh->savedport = port;
2676 logeventf(ssh, "Looking up host \"%s\"%s", host,
2677 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2678 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2679 addr = name_lookup(host, port, realhost, &ssh->cfg,
2680 ssh->cfg.addressfamily);
2681 if ((err = sk_addr_error(addr)) != NULL) {
2689 ssh->fn = &fn_table;
2690 ssh->s = new_connection(addr, *realhost, port,
2691 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2692 if ((err = sk_socket_error(ssh->s)) != NULL) {
2694 notify_remote_exit(ssh->frontend);
2702 * Throttle or unthrottle the SSH connection.
2704 static void ssh1_throttle(Ssh ssh, int adjust)
2706 int old_count = ssh->v1_throttle_count;
2707 ssh->v1_throttle_count += adjust;
2708 assert(ssh->v1_throttle_count >= 0);
2709 if (ssh->v1_throttle_count && !old_count) {
2710 ssh_set_frozen(ssh, 1);
2711 } else if (!ssh->v1_throttle_count && old_count) {
2712 ssh_set_frozen(ssh, 0);
2717 * Throttle or unthrottle _all_ local data streams (for when sends
2718 * on the SSH connection itself back up).
2720 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2723 struct ssh_channel *c;
2725 if (enable == ssh->throttled_all)
2727 ssh->throttled_all = enable;
2728 ssh->overall_bufsize = bufsize;
2731 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2733 case CHAN_MAINSESSION:
2735 * This is treated separately, outside the switch.
2739 x11_override_throttle(c->u.x11.s, enable);
2742 /* Agent channels require no buffer management. */
2745 pfd_override_throttle(c->u.pfd.s, enable);
2751 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2753 Ssh ssh = (Ssh) sshv;
2755 ssh->agent_response = reply;
2756 ssh->agent_response_len = replylen;
2758 if (ssh->version == 1)
2759 do_ssh1_login(ssh, NULL, -1, NULL);
2761 do_ssh2_authconn(ssh, NULL, -1, NULL);
2764 static void ssh_dialog_callback(void *sshv, int ret)
2766 Ssh ssh = (Ssh) sshv;
2768 ssh->user_response = ret;
2770 if (ssh->version == 1)
2771 do_ssh1_login(ssh, NULL, -1, NULL);
2773 do_ssh2_transport(ssh, NULL, -1, NULL);
2776 * This may have unfrozen the SSH connection, so do a
2779 ssh_process_queued_incoming_data(ssh);
2782 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2784 struct ssh_channel *c = (struct ssh_channel *)cv;
2786 void *sentreply = reply;
2789 /* Fake SSH_AGENT_FAILURE. */
2790 sentreply = "\0\0\0\1\5";
2793 if (ssh->version == 2) {
2794 ssh2_add_channel_data(c, sentreply, replylen);
2797 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2798 PKT_INT, c->remoteid,
2801 PKT_DATA, sentreply, replylen,
2810 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2811 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2812 * => log `wire_reason'.
2814 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2815 int code, int clean_exit)
2819 client_reason = wire_reason;
2821 error = dupprintf("Disconnected: %s", client_reason);
2823 error = dupstr("Disconnected");
2825 if (ssh->version == 1) {
2826 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2828 } else if (ssh->version == 2) {
2829 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2830 ssh2_pkt_adduint32(pktout, code);
2831 ssh2_pkt_addstring(pktout, wire_reason);
2832 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2833 ssh2_pkt_send_noqueue(ssh, pktout);
2836 ssh->close_expected = TRUE;
2837 ssh->clean_exit = clean_exit;
2838 ssh_closing((Plug)ssh, error, 0, 0);
2843 * Handle the key exchange and user authentication phases.
2845 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2846 struct Packet *pktin)
2849 unsigned char cookie[8], *ptr;
2850 struct RSAKey servkey, hostkey;
2851 struct MD5Context md5c;
2852 struct do_ssh1_login_state {
2854 unsigned char *rsabuf, *keystr1, *keystr2;
2855 unsigned long supported_ciphers_mask, supported_auths_mask;
2856 int tried_publickey, tried_agent;
2857 int tis_auth_refused, ccard_auth_refused;
2858 unsigned char session_id[16];
2861 void *publickey_blob;
2862 int publickey_bloblen;
2863 char *publickey_comment;
2864 int publickey_encrypted;
2865 prompts_t *cur_prompt;
2868 unsigned char request[5], *response, *p;
2878 crState(do_ssh1_login_state);
2880 crBegin(ssh->do_ssh1_login_crstate);
2885 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2886 bombout(("Public key packet not received"));
2890 logevent("Received public keys");
2892 ptr = ssh_pkt_getdata(pktin, 8);
2894 bombout(("SSH-1 public key packet stopped before random cookie"));
2897 memcpy(cookie, ptr, 8);
2899 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2900 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2901 bombout(("Failed to read SSH-1 public keys from public key packet"));
2906 * Log the host key fingerprint.
2910 logevent("Host key fingerprint is:");
2911 strcpy(logmsg, " ");
2912 hostkey.comment = NULL;
2913 rsa_fingerprint(logmsg + strlen(logmsg),
2914 sizeof(logmsg) - strlen(logmsg), &hostkey);
2918 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2919 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2920 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2922 ssh->v1_local_protoflags =
2923 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2924 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2927 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2928 MD5Update(&md5c, s->keystr1, servkey.bytes);
2929 MD5Update(&md5c, cookie, 8);
2930 MD5Final(s->session_id, &md5c);
2932 for (i = 0; i < 32; i++)
2933 ssh->session_key[i] = random_byte();
2936 * Verify that the `bits' and `bytes' parameters match.
2938 if (hostkey.bits > hostkey.bytes * 8 ||
2939 servkey.bits > servkey.bytes * 8) {
2940 bombout(("SSH-1 public keys were badly formatted"));
2944 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2946 s->rsabuf = snewn(s->len, unsigned char);
2949 * Verify the host key.
2953 * First format the key into a string.
2955 int len = rsastr_len(&hostkey);
2956 char fingerprint[100];
2957 char *keystr = snewn(len, char);
2958 rsastr_fmt(keystr, &hostkey);
2959 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2961 ssh_set_frozen(ssh, 1);
2962 s->dlgret = verify_ssh_host_key(ssh->frontend,
2963 ssh->savedhost, ssh->savedport,
2964 "rsa", keystr, fingerprint,
2965 ssh_dialog_callback, ssh);
2967 if (s->dlgret < 0) {
2971 bombout(("Unexpected data from server while waiting"
2972 " for user host key response"));
2975 } while (pktin || inlen > 0);
2976 s->dlgret = ssh->user_response;
2978 ssh_set_frozen(ssh, 0);
2980 if (s->dlgret == 0) {
2981 ssh_disconnect(ssh, "User aborted at host key verification",
2987 for (i = 0; i < 32; i++) {
2988 s->rsabuf[i] = ssh->session_key[i];
2990 s->rsabuf[i] ^= s->session_id[i];
2993 if (hostkey.bytes > servkey.bytes) {
2994 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2996 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2998 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3000 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3003 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3007 logevent("Encrypted session key");
3010 int cipher_chosen = 0, warn = 0;
3011 char *cipher_string = NULL;
3013 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3014 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3015 if (next_cipher == CIPHER_WARN) {
3016 /* If/when we choose a cipher, warn about it */
3018 } else if (next_cipher == CIPHER_AES) {
3019 /* XXX Probably don't need to mention this. */
3020 logevent("AES not supported in SSH-1, skipping");
3022 switch (next_cipher) {
3023 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3024 cipher_string = "3DES"; break;
3025 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3026 cipher_string = "Blowfish"; break;
3027 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3028 cipher_string = "single-DES"; break;
3030 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3034 if (!cipher_chosen) {
3035 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3036 bombout(("Server violates SSH-1 protocol by not "
3037 "supporting 3DES encryption"));
3039 /* shouldn't happen */
3040 bombout(("No supported ciphers found"));
3044 /* Warn about chosen cipher if necessary. */
3046 ssh_set_frozen(ssh, 1);
3047 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3048 ssh_dialog_callback, ssh);
3049 if (s->dlgret < 0) {
3053 bombout(("Unexpected data from server while waiting"
3054 " for user response"));
3057 } while (pktin || inlen > 0);
3058 s->dlgret = ssh->user_response;
3060 ssh_set_frozen(ssh, 0);
3061 if (s->dlgret == 0) {
3062 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3069 switch (s->cipher_type) {
3070 case SSH_CIPHER_3DES:
3071 logevent("Using 3DES encryption");
3073 case SSH_CIPHER_DES:
3074 logevent("Using single-DES encryption");
3076 case SSH_CIPHER_BLOWFISH:
3077 logevent("Using Blowfish encryption");
3081 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3082 PKT_CHAR, s->cipher_type,
3083 PKT_DATA, cookie, 8,
3084 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3085 PKT_DATA, s->rsabuf, s->len,
3086 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3088 logevent("Trying to enable encryption...");
3092 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3093 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3095 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3096 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3097 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3099 ssh->crcda_ctx = crcda_make_context();
3100 logevent("Installing CRC compensation attack detector");
3102 if (servkey.modulus) {
3103 sfree(servkey.modulus);
3104 servkey.modulus = NULL;
3106 if (servkey.exponent) {
3107 sfree(servkey.exponent);
3108 servkey.exponent = NULL;
3110 if (hostkey.modulus) {
3111 sfree(hostkey.modulus);
3112 hostkey.modulus = NULL;
3114 if (hostkey.exponent) {
3115 sfree(hostkey.exponent);
3116 hostkey.exponent = NULL;
3120 if (pktin->type != SSH1_SMSG_SUCCESS) {
3121 bombout(("Encryption not successfully enabled"));
3125 logevent("Successfully started encryption");
3127 fflush(stdout); /* FIXME eh? */
3129 if (!*ssh->cfg.username) {
3130 int ret; /* need not be kept over crReturn */
3131 s->cur_prompt = new_prompts(ssh->frontend);
3132 s->cur_prompt->to_server = TRUE;
3133 s->cur_prompt->name = dupstr("SSH login name");
3134 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3135 lenof(s->username));
3136 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3139 crWaitUntil(!pktin);
3140 ret = get_userpass_input(s->cur_prompt, in, inlen);
3145 * Failed to get a username. Terminate.
3147 free_prompts(s->cur_prompt);
3148 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3151 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3152 lenof(s->username));
3153 free_prompts(s->cur_prompt);
3155 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3156 s->username[sizeof(s->username)-1] = '\0';
3159 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3161 char *userlog = dupprintf("Sent username \"%s\"", s->username);
3163 if (flags & FLAG_INTERACTIVE &&
3164 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3165 c_write_str(ssh, userlog);
3166 c_write_str(ssh, "\r\n");
3174 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3175 /* We must not attempt PK auth. Pretend we've already tried it. */
3176 s->tried_publickey = s->tried_agent = 1;
3178 s->tried_publickey = s->tried_agent = 0;
3180 s->tis_auth_refused = s->ccard_auth_refused = 0;
3182 * Load the public half of any configured keyfile for later use.
3184 if (!filename_is_null(ssh->cfg.keyfile)) {
3186 logeventf(ssh, "Reading private key file \"%.150s\"",
3187 filename_to_str(&ssh->cfg.keyfile));
3188 keytype = key_type(&ssh->cfg.keyfile);
3189 if (keytype == SSH_KEYTYPE_SSH1) {
3191 if (rsakey_pubblob(&ssh->cfg.keyfile,
3192 &s->publickey_blob, &s->publickey_bloblen,
3193 &s->publickey_comment, &error)) {
3194 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3198 logeventf(ssh, "Unable to load private key (%s)", error);
3199 msgbuf = dupprintf("Unable to load private key file "
3200 "\"%.150s\" (%s)\r\n",
3201 filename_to_str(&ssh->cfg.keyfile),
3203 c_write_str(ssh, msgbuf);
3205 s->publickey_blob = NULL;
3209 logeventf(ssh, "Unable to use this key file (%s)",
3210 key_type_to_str(keytype));
3211 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3213 filename_to_str(&ssh->cfg.keyfile),
3214 key_type_to_str(keytype));
3215 c_write_str(ssh, msgbuf);
3217 s->publickey_blob = NULL;
3220 s->publickey_blob = NULL;
3222 while (pktin->type == SSH1_SMSG_FAILURE) {
3223 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3225 if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
3227 * Attempt RSA authentication using Pageant.
3233 logevent("Pageant is running. Requesting keys.");
3235 /* Request the keys held by the agent. */
3236 PUT_32BIT(s->request, 1);
3237 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3238 if (!agent_query(s->request, 5, &r, &s->responselen,
3239 ssh_agent_callback, ssh)) {
3243 bombout(("Unexpected data from server while waiting"
3244 " for agent response"));
3247 } while (pktin || inlen > 0);
3248 r = ssh->agent_response;
3249 s->responselen = ssh->agent_response_len;
3251 s->response = (unsigned char *) r;
3252 if (s->response && s->responselen >= 5 &&
3253 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3254 s->p = s->response + 5;
3255 s->nkeys = GET_32BIT(s->p);
3257 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3258 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3259 unsigned char *pkblob = s->p;
3263 do { /* do while (0) to make breaking easy */
3264 n = ssh1_read_bignum
3265 (s->p, s->responselen-(s->p-s->response),
3270 n = ssh1_read_bignum
3271 (s->p, s->responselen-(s->p-s->response),
3276 if (s->responselen - (s->p-s->response) < 4)
3278 s->commentlen = GET_32BIT(s->p);
3280 if (s->responselen - (s->p-s->response) <
3283 s->commentp = (char *)s->p;
3284 s->p += s->commentlen;
3288 logevent("Pageant key list packet was truncated");
3292 if (s->publickey_blob) {
3293 if (!memcmp(pkblob, s->publickey_blob,
3294 s->publickey_bloblen)) {
3295 logeventf(ssh, "Pageant key #%d matches "
3296 "configured key file", s->keyi);
3297 s->tried_publickey = 1;
3299 /* Skip non-configured key */
3302 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3303 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3304 PKT_BIGNUM, s->key.modulus, PKT_END);
3306 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3307 logevent("Key refused");
3310 logevent("Received RSA challenge");
3311 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3312 bombout(("Server's RSA challenge was badly formatted"));
3317 char *agentreq, *q, *ret;
3320 len = 1 + 4; /* message type, bit count */
3321 len += ssh1_bignum_length(s->key.exponent);
3322 len += ssh1_bignum_length(s->key.modulus);
3323 len += ssh1_bignum_length(s->challenge);
3324 len += 16; /* session id */
3325 len += 4; /* response format */
3326 agentreq = snewn(4 + len, char);
3327 PUT_32BIT(agentreq, len);
3329 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3330 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3332 q += ssh1_write_bignum(q, s->key.exponent);
3333 q += ssh1_write_bignum(q, s->key.modulus);
3334 q += ssh1_write_bignum(q, s->challenge);
3335 memcpy(q, s->session_id, 16);
3337 PUT_32BIT(q, 1); /* response format */
3338 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3339 ssh_agent_callback, ssh)) {
3344 bombout(("Unexpected data from server"
3345 " while waiting for agent"
3349 } while (pktin || inlen > 0);
3350 vret = ssh->agent_response;
3351 retlen = ssh->agent_response_len;
3356 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3357 logevent("Sending Pageant's response");
3358 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3359 PKT_DATA, ret + 5, 16,
3363 if (pktin->type == SSH1_SMSG_SUCCESS) {
3365 ("Pageant's response accepted");
3366 if (flags & FLAG_VERBOSE) {
3367 c_write_str(ssh, "Authenticated using"
3369 c_write(ssh, s->commentp,
3371 c_write_str(ssh, "\" from agent\r\n");
3376 ("Pageant's response not accepted");
3379 ("Pageant failed to answer challenge");
3383 logevent("No reply received from Pageant");
3386 freebn(s->key.exponent);
3387 freebn(s->key.modulus);
3388 freebn(s->challenge);
3393 if (s->publickey_blob && !s->tried_publickey)
3394 logevent("Configured key file not in Pageant");
3399 if (s->publickey_blob && !s->tried_publickey) {
3401 * Try public key authentication with the specified
3404 int got_passphrase; /* need not be kept over crReturn */
3405 if (flags & FLAG_VERBOSE)
3406 c_write_str(ssh, "Trying public key authentication.\r\n");
3407 logeventf(ssh, "Trying public key \"%s\"",
3408 filename_to_str(&ssh->cfg.keyfile));
3409 s->tried_publickey = 1;
3410 got_passphrase = FALSE;
3411 while (!got_passphrase) {
3413 * Get a passphrase, if necessary.
3415 char *passphrase = NULL; /* only written after crReturn */
3417 if (!s->publickey_encrypted) {
3418 if (flags & FLAG_VERBOSE)
3419 c_write_str(ssh, "No passphrase required.\r\n");
3422 int ret; /* need not be kept over crReturn */
3423 s->cur_prompt = new_prompts(ssh->frontend);
3424 s->cur_prompt->to_server = FALSE;
3425 s->cur_prompt->name = dupstr("SSH key passphrase");
3426 add_prompt(s->cur_prompt,
3427 dupprintf("Passphrase for key \"%.100s\": ",
3428 s->publickey_comment),
3429 FALSE, SSH_MAX_PASSWORD_LEN);
3430 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3433 crWaitUntil(!pktin);
3434 ret = get_userpass_input(s->cur_prompt, in, inlen);
3438 /* Failed to get a passphrase. Terminate. */
3439 free_prompts(s->cur_prompt);
3440 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3444 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3445 free_prompts(s->cur_prompt);
3448 * Try decrypting key with passphrase.
3450 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3453 memset(passphrase, 0, strlen(passphrase));
3457 /* Correct passphrase. */
3458 got_passphrase = TRUE;
3459 } else if (ret == 0) {
3460 c_write_str(ssh, "Couldn't load private key from ");
3461 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3462 c_write_str(ssh, " (");
3463 c_write_str(ssh, error);
3464 c_write_str(ssh, ").\r\n");
3465 got_passphrase = FALSE;
3466 break; /* go and try something else */
3467 } else if (ret == -1) {
3468 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3469 got_passphrase = FALSE;
3472 assert(0 && "unexpected return from loadrsakey()");
3476 if (got_passphrase) {
3479 * Send a public key attempt.
3481 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3482 PKT_BIGNUM, s->key.modulus, PKT_END);
3485 if (pktin->type == SSH1_SMSG_FAILURE) {
3486 c_write_str(ssh, "Server refused our public key.\r\n");
3487 continue; /* go and try something else */
3489 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3490 bombout(("Bizarre response to offer of public key"));
3496 unsigned char buffer[32];
3497 Bignum challenge, response;
3499 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3500 bombout(("Server's RSA challenge was badly formatted"));
3503 response = rsadecrypt(challenge, &s->key);
3504 freebn(s->key.private_exponent);/* burn the evidence */
3506 for (i = 0; i < 32; i++) {
3507 buffer[i] = bignum_byte(response, 31 - i);
3511 MD5Update(&md5c, buffer, 32);
3512 MD5Update(&md5c, s->session_id, 16);
3513 MD5Final(buffer, &md5c);
3515 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3516 PKT_DATA, buffer, 16, PKT_END);
3523 if (pktin->type == SSH1_SMSG_FAILURE) {
3524 if (flags & FLAG_VERBOSE)
3525 c_write_str(ssh, "Failed to authenticate with"
3526 " our public key.\r\n");
3527 continue; /* go and try something else */
3528 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3529 bombout(("Bizarre response to RSA authentication response"));
3533 break; /* we're through! */
3539 * Otherwise, try various forms of password-like authentication.
3541 s->cur_prompt = new_prompts(ssh->frontend);
3543 if (ssh->cfg.try_tis_auth &&
3544 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3545 !s->tis_auth_refused) {
3546 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3547 logevent("Requested TIS authentication");
3548 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3550 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3551 logevent("TIS authentication declined");
3552 if (flags & FLAG_INTERACTIVE)
3553 c_write_str(ssh, "TIS authentication refused.\r\n");
3554 s->tis_auth_refused = 1;
3559 char *instr_suf, *prompt;
3561 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3563 bombout(("TIS challenge packet was badly formed"));
3566 logevent("Received TIS challenge");
3567 s->cur_prompt->to_server = TRUE;
3568 s->cur_prompt->name = dupstr("SSH TIS authentication");
3569 /* Prompt heuristic comes from OpenSSH */
3570 if (memchr(challenge, '\n', challengelen)) {
3571 instr_suf = dupstr("");
3572 prompt = dupprintf("%.*s", challengelen, challenge);
3574 instr_suf = dupprintf("%.*s", challengelen, challenge);
3575 prompt = dupstr("Response: ");
3577 s->cur_prompt->instruction =
3578 dupprintf("Using TIS authentication.%s%s",
3579 (*instr_suf) ? "\n" : "",
3581 s->cur_prompt->instr_reqd = TRUE;
3582 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3586 if (ssh->cfg.try_tis_auth &&
3587 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3588 !s->ccard_auth_refused) {
3589 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3590 logevent("Requested CryptoCard authentication");
3591 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3593 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3594 logevent("CryptoCard authentication declined");
3595 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3596 s->ccard_auth_refused = 1;
3601 char *instr_suf, *prompt;
3603 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3605 bombout(("CryptoCard challenge packet was badly formed"));
3608 logevent("Received CryptoCard challenge");
3609 s->cur_prompt->to_server = TRUE;
3610 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3611 s->cur_prompt->name_reqd = FALSE;
3612 /* Prompt heuristic comes from OpenSSH */
3613 if (memchr(challenge, '\n', challengelen)) {
3614 instr_suf = dupstr("");
3615 prompt = dupprintf("%.*s", challengelen, challenge);
3617 instr_suf = dupprintf("%.*s", challengelen, challenge);
3618 prompt = dupstr("Response: ");
3620 s->cur_prompt->instruction =
3621 dupprintf("Using CryptoCard authentication.%s%s",
3622 (*instr_suf) ? "\n" : "",
3624 s->cur_prompt->instr_reqd = TRUE;
3625 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3629 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3630 s->cur_prompt->to_server = TRUE;
3631 s->cur_prompt->name = dupstr("SSH password");
3632 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3633 s->username, ssh->savedhost),
3634 FALSE, SSH_MAX_PASSWORD_LEN);
3638 * Show password prompt, having first obtained it via a TIS
3639 * or CryptoCard exchange if we're doing TIS or CryptoCard
3643 int ret; /* need not be kept over crReturn */
3644 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3647 crWaitUntil(!pktin);
3648 ret = get_userpass_input(s->cur_prompt, in, inlen);
3653 * Failed to get a password (for example
3654 * because one was supplied on the command line
3655 * which has already failed to work). Terminate.
3657 free_prompts(s->cur_prompt);
3658 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
3663 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3665 * Defence against traffic analysis: we send a
3666 * whole bunch of packets containing strings of
3667 * different lengths. One of these strings is the
3668 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3669 * The others are all random data in
3670 * SSH1_MSG_IGNORE packets. This way a passive
3671 * listener can't tell which is the password, and
3672 * hence can't deduce the password length.
3674 * Anybody with a password length greater than 16
3675 * bytes is going to have enough entropy in their
3676 * password that a listener won't find it _that_
3677 * much help to know how long it is. So what we'll
3680 * - if password length < 16, we send 15 packets
3681 * containing string lengths 1 through 15
3683 * - otherwise, we let N be the nearest multiple
3684 * of 8 below the password length, and send 8
3685 * packets containing string lengths N through
3686 * N+7. This won't obscure the order of
3687 * magnitude of the password length, but it will
3688 * introduce a bit of extra uncertainty.
3690 * A few servers (the old 1.2.18 through 1.2.22)
3691 * can't deal with SSH1_MSG_IGNORE. For these
3692 * servers, we need an alternative defence. We make
3693 * use of the fact that the password is interpreted
3694 * as a C string: so we can append a NUL, then some
3697 * One server (a Cisco one) can deal with neither
3698 * SSH1_MSG_IGNORE _nor_ a padded password string.
3699 * For this server we are left with no defences
3700 * against password length sniffing.
3702 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3704 * The server can deal with SSH1_MSG_IGNORE, so
3705 * we can use the primary defence.
3707 int bottom, top, pwlen, i;
3710 pwlen = strlen(s->cur_prompt->prompts[0]->result);
3712 bottom = 0; /* zero length passwords are OK! :-) */
3715 bottom = pwlen & ~7;
3719 assert(pwlen >= bottom && pwlen <= top);
3721 randomstr = snewn(top + 1, char);
3723 for (i = bottom; i <= top; i++) {
3725 defer_packet(ssh, s->pwpkt_type,
3726 PKTT_PASSWORD, PKT_STR,
3727 s->cur_prompt->prompts[0]->result,
3728 PKTT_OTHER, PKT_END);
3730 for (j = 0; j < i; j++) {
3732 randomstr[j] = random_byte();
3733 } while (randomstr[j] == '\0');
3735 randomstr[i] = '\0';
3736 defer_packet(ssh, SSH1_MSG_IGNORE,
3737 PKT_STR, randomstr, PKT_END);
3740 logevent("Sending password with camouflage packets");
3741 ssh_pkt_defersend(ssh);
3744 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3746 * The server can't deal with SSH1_MSG_IGNORE
3747 * but can deal with padded passwords, so we
3748 * can use the secondary defence.
3754 len = strlen(s->cur_prompt->prompts[0]->result);
3755 if (len < sizeof(string)) {
3757 strcpy(string, s->cur_prompt->prompts[0]->result);
3758 len++; /* cover the zero byte */
3759 while (len < sizeof(string)) {
3760 string[len++] = (char) random_byte();
3763 ss = s->cur_prompt->prompts[0]->result;
3765 logevent("Sending length-padded password");
3766 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3767 PKT_INT, len, PKT_DATA, ss, len,
3768 PKTT_OTHER, PKT_END);
3771 * The server has _both_
3772 * BUG_CHOKES_ON_SSH1_IGNORE and
3773 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3774 * therefore nothing we can do.
3777 len = strlen(s->cur_prompt->prompts[0]->result);
3778 logevent("Sending unpadded password");
3779 send_packet(ssh, s->pwpkt_type,
3780 PKTT_PASSWORD, PKT_INT, len,
3781 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
3782 PKTT_OTHER, PKT_END);
3785 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3786 PKT_STR, s->cur_prompt->prompts[0]->result,
3787 PKTT_OTHER, PKT_END);
3789 logevent("Sent password");
3790 free_prompts(s->cur_prompt);
3792 if (pktin->type == SSH1_SMSG_FAILURE) {
3793 if (flags & FLAG_VERBOSE)
3794 c_write_str(ssh, "Access denied\r\n");
3795 logevent("Authentication refused");
3796 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3797 bombout(("Strange packet received, type %d", pktin->type));
3803 if (s->publickey_blob) {
3804 sfree(s->publickey_blob);
3805 sfree(s->publickey_comment);
3808 logevent("Authentication successful");
3813 void sshfwd_close(struct ssh_channel *c)
3817 if (ssh->state == SSH_STATE_CLOSED)
3820 if (c && !c->closes) {
3822 * If halfopen is true, we have sent
3823 * CHANNEL_OPEN for this channel, but it hasn't even been
3824 * acknowledged by the server. So we must set a close flag
3825 * on it now, and then when the server acks the channel
3826 * open, we can close it then.
3829 if (ssh->version == 1) {
3830 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3833 struct Packet *pktout;
3834 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3835 ssh2_pkt_adduint32(pktout, c->remoteid);
3836 ssh2_pkt_send(ssh, pktout);
3839 c->closes = 1; /* sent MSG_CLOSE */
3840 if (c->type == CHAN_X11) {
3842 logevent("Forwarded X11 connection terminated");
3843 } else if (c->type == CHAN_SOCKDATA ||
3844 c->type == CHAN_SOCKDATA_DORMANT) {
3846 logevent("Forwarded port closed");
3851 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3855 if (ssh->state == SSH_STATE_CLOSED)
3858 if (ssh->version == 1) {
3859 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3860 PKT_INT, c->remoteid,
3862 PKT_INT, len, PKT_DATA, buf, len,
3863 PKTT_OTHER, PKT_END);
3865 * In SSH-1 we can return 0 here - implying that forwarded
3866 * connections are never individually throttled - because
3867 * the only circumstance that can cause throttling will be
3868 * the whole SSH connection backing up, in which case
3869 * _everything_ will be throttled as a whole.
3873 ssh2_add_channel_data(c, buf, len);
3874 return ssh2_try_send(c);
3878 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3882 if (ssh->state == SSH_STATE_CLOSED)
3885 if (ssh->version == 1) {
3886 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3887 c->v.v1.throttling = 0;
3888 ssh1_throttle(ssh, -1);
3891 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3895 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3897 struct queued_handler *qh = ssh->qhead;
3901 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3904 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3905 ssh->packet_dispatch[qh->msg1] = NULL;
3908 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3909 ssh->packet_dispatch[qh->msg2] = NULL;
3913 ssh->qhead = qh->next;
3915 if (ssh->qhead->msg1 > 0) {
3916 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3917 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3919 if (ssh->qhead->msg2 > 0) {
3920 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3921 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3924 ssh->qhead = ssh->qtail = NULL;
3925 ssh->packet_dispatch[pktin->type] = NULL;
3928 qh->handler(ssh, pktin, qh->ctx);
3933 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3934 chandler_fn_t handler, void *ctx)
3936 struct queued_handler *qh;
3938 qh = snew(struct queued_handler);
3941 qh->handler = handler;
3945 if (ssh->qtail == NULL) {
3949 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3950 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3953 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3954 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3957 ssh->qtail->next = qh;
3962 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3964 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3966 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3967 SSH2_MSG_REQUEST_SUCCESS)) {
3968 logeventf(ssh, "Remote port forwarding from %s enabled",
3971 logeventf(ssh, "Remote port forwarding from %s refused",
3974 rpf = del234(ssh->rportfwds, pf);
3980 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3982 const char *portfwd_strptr = cfg->portfwd;
3983 struct ssh_portfwd *epf;
3986 if (!ssh->portfwds) {
3987 ssh->portfwds = newtree234(ssh_portcmp);
3990 * Go through the existing port forwardings and tag them
3991 * with status==DESTROY. Any that we want to keep will be
3992 * re-enabled (status==KEEP) as we go through the
3993 * configuration and find out which bits are the same as
3996 struct ssh_portfwd *epf;
3998 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3999 epf->status = DESTROY;
4002 while (*portfwd_strptr) {
4003 char address_family, type;
4004 int sport,dport,sserv,dserv;
4005 char sports[256], dports[256], saddr[256], host[256];
4008 address_family = 'A';
4010 if (*portfwd_strptr == 'A' ||
4011 *portfwd_strptr == '4' ||
4012 *portfwd_strptr == '6')
4013 address_family = *portfwd_strptr++;
4014 if (*portfwd_strptr == 'L' ||
4015 *portfwd_strptr == 'R' ||
4016 *portfwd_strptr == 'D')
4017 type = *portfwd_strptr++;
4022 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4023 if (*portfwd_strptr == ':') {
4025 * We've seen a colon in the middle of the
4026 * source port number. This means that
4027 * everything we've seen until now is the
4028 * source _address_, so we'll move it into
4029 * saddr and start sports from the beginning
4034 if (ssh->version == 1 && type == 'R') {
4035 logeventf(ssh, "SSH-1 cannot handle remote source address "
4036 "spec \"%s\"; ignoring", sports);
4038 strcpy(saddr, sports);
4041 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4045 if (*portfwd_strptr == '\t')
4048 while (*portfwd_strptr && *portfwd_strptr != ':') {
4049 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4052 if (*portfwd_strptr == ':')
4055 while (*portfwd_strptr) {
4056 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4060 dport = atoi(dports);
4064 dport = net_service_lookup(dports);
4066 logeventf(ssh, "Service lookup failed for destination"
4067 " port \"%s\"", dports);
4071 while (*portfwd_strptr) portfwd_strptr++;
4075 portfwd_strptr++; /* eat the NUL and move to next one */
4077 sport = atoi(sports);
4081 sport = net_service_lookup(sports);
4083 logeventf(ssh, "Service lookup failed for source"
4084 " port \"%s\"", sports);
4087 if (sport && dport) {
4088 /* Set up a description of the source port. */
4089 struct ssh_portfwd *pfrec, *epfrec;
4091 pfrec = snew(struct ssh_portfwd);
4093 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4094 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4095 pfrec->sport = sport;
4096 pfrec->daddr = *host ? dupstr(host) : NULL;
4097 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4098 pfrec->dport = dport;
4099 pfrec->local = NULL;
4100 pfrec->remote = NULL;
4101 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4102 address_family == '6' ? ADDRTYPE_IPV6 :
4105 epfrec = add234(ssh->portfwds, pfrec);
4106 if (epfrec != pfrec) {
4108 * We already have a port forwarding with precisely
4109 * these parameters. Hence, no need to do anything;
4110 * simply tag the existing one as KEEP.
4112 epfrec->status = KEEP;
4113 free_portfwd(pfrec);
4115 pfrec->status = CREATE;
4121 * Now go through and destroy any port forwardings which were
4124 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4125 if (epf->status == DESTROY) {
4128 message = dupprintf("%s port forwarding from %s%s%d",
4129 epf->type == 'L' ? "local" :
4130 epf->type == 'R' ? "remote" : "dynamic",
4131 epf->saddr ? epf->saddr : "",
4132 epf->saddr ? ":" : "",
4135 if (epf->type != 'D') {
4136 char *msg2 = dupprintf("%s to %s:%d", message,
4137 epf->daddr, epf->dport);
4142 logeventf(ssh, "Cancelling %s", message);
4146 struct ssh_rportfwd *rpf = epf->remote;
4147 struct Packet *pktout;
4150 * Cancel the port forwarding at the server
4153 if (ssh->version == 1) {
4155 * We cannot cancel listening ports on the
4156 * server side in SSH-1! There's no message
4157 * to support it. Instead, we simply remove
4158 * the rportfwd record from the local end
4159 * so that any connections the server tries
4160 * to make on it are rejected.
4163 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4164 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4165 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4167 ssh2_pkt_addstring(pktout, epf->saddr);
4168 } else if (ssh->cfg.rport_acceptall) {
4169 /* XXX: ssh->cfg.rport_acceptall may not represent
4170 * what was used to open the original connection,
4171 * since it's reconfigurable. */
4172 ssh2_pkt_addstring(pktout, "0.0.0.0");
4174 ssh2_pkt_addstring(pktout, "127.0.0.1");
4176 ssh2_pkt_adduint32(pktout, epf->sport);
4177 ssh2_pkt_send(ssh, pktout);
4180 del234(ssh->rportfwds, rpf);
4182 } else if (epf->local) {
4183 pfd_terminate(epf->local);
4186 delpos234(ssh->portfwds, i);
4188 i--; /* so we don't skip one in the list */
4192 * And finally, set up any new port forwardings (status==CREATE).
4194 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4195 if (epf->status == CREATE) {
4196 char *sportdesc, *dportdesc;
4197 sportdesc = dupprintf("%s%s%s%s%d%s",
4198 epf->saddr ? epf->saddr : "",
4199 epf->saddr ? ":" : "",
4200 epf->sserv ? epf->sserv : "",
4201 epf->sserv ? "(" : "",
4203 epf->sserv ? ")" : "");
4204 if (epf->type == 'D') {
4207 dportdesc = dupprintf("%s:%s%s%d%s",
4209 epf->dserv ? epf->dserv : "",
4210 epf->dserv ? "(" : "",
4212 epf->dserv ? ")" : "");
4215 if (epf->type == 'L') {
4216 const char *err = pfd_addforward(epf->daddr, epf->dport,
4217 epf->saddr, epf->sport,
4220 epf->addressfamily);
4222 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4223 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4224 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4225 sportdesc, dportdesc,
4226 err ? " failed: " : "", err ? err : "");
4227 } else if (epf->type == 'D') {
4228 const char *err = pfd_addforward(NULL, -1,
4229 epf->saddr, epf->sport,
4232 epf->addressfamily);
4234 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4235 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4236 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4238 err ? " failed: " : "", err ? err : "");
4240 struct ssh_rportfwd *pf;
4243 * Ensure the remote port forwardings tree exists.
4245 if (!ssh->rportfwds) {
4246 if (ssh->version == 1)
4247 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4249 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4252 pf = snew(struct ssh_rportfwd);
4253 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4254 pf->dhost[lenof(pf->dhost)-1] = '\0';
4255 pf->dport = epf->dport;
4256 pf->sport = epf->sport;
4257 if (add234(ssh->rportfwds, pf) != pf) {
4258 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4259 epf->daddr, epf->dport);
4262 logeventf(ssh, "Requesting remote port %s"
4263 " forward to %s", sportdesc, dportdesc);
4265 pf->sportdesc = sportdesc;
4270 if (ssh->version == 1) {
4271 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4272 PKT_INT, epf->sport,
4273 PKT_STR, epf->daddr,
4274 PKT_INT, epf->dport,
4276 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4278 ssh_rportfwd_succfail, pf);
4280 struct Packet *pktout;
4281 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4282 ssh2_pkt_addstring(pktout, "tcpip-forward");
4283 ssh2_pkt_addbool(pktout, 1);/* want reply */
4285 ssh2_pkt_addstring(pktout, epf->saddr);
4286 } else if (cfg->rport_acceptall) {
4287 ssh2_pkt_addstring(pktout, "0.0.0.0");
4289 ssh2_pkt_addstring(pktout, "127.0.0.1");
4291 ssh2_pkt_adduint32(pktout, epf->sport);
4292 ssh2_pkt_send(ssh, pktout);
4294 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4295 SSH2_MSG_REQUEST_FAILURE,
4296 ssh_rportfwd_succfail, pf);
4305 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4308 int stringlen, bufsize;
4310 ssh_pkt_getstring(pktin, &string, &stringlen);
4311 if (string == NULL) {
4312 bombout(("Incoming terminal data packet was badly formed"));
4316 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4318 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4319 ssh->v1_stdout_throttling = 1;
4320 ssh1_throttle(ssh, +1);
4324 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4326 /* Remote side is trying to open a channel to talk to our
4327 * X-Server. Give them back a local channel number. */
4328 struct ssh_channel *c;
4329 int remoteid = ssh_pkt_getuint32(pktin);
4331 logevent("Received X11 connect request");
4332 /* Refuse if X11 forwarding is disabled. */
4333 if (!ssh->X11_fwd_enabled) {
4334 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4335 PKT_INT, remoteid, PKT_END);
4336 logevent("Rejected X11 connect request");
4338 c = snew(struct ssh_channel);
4341 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4342 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4343 logevent("Opening X11 forward connection failed");
4345 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4346 PKT_INT, remoteid, PKT_END);
4349 ("Opening X11 forward connection succeeded");
4350 c->remoteid = remoteid;
4351 c->halfopen = FALSE;
4352 c->localid = alloc_channel_id(ssh);
4354 c->v.v1.throttling = 0;
4355 c->type = CHAN_X11; /* identify channel type */
4356 add234(ssh->channels, c);
4357 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4358 PKT_INT, c->remoteid, PKT_INT,
4359 c->localid, PKT_END);
4360 logevent("Opened X11 forward channel");
4365 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4367 /* Remote side is trying to open a channel to talk to our
4368 * agent. Give them back a local channel number. */
4369 struct ssh_channel *c;
4370 int remoteid = ssh_pkt_getuint32(pktin);
4372 /* Refuse if agent forwarding is disabled. */
4373 if (!ssh->agentfwd_enabled) {
4374 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4375 PKT_INT, remoteid, PKT_END);
4377 c = snew(struct ssh_channel);
4379 c->remoteid = remoteid;
4380 c->halfopen = FALSE;
4381 c->localid = alloc_channel_id(ssh);
4383 c->v.v1.throttling = 0;
4384 c->type = CHAN_AGENT; /* identify channel type */
4385 c->u.a.lensofar = 0;
4386 add234(ssh->channels, c);
4387 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4388 PKT_INT, c->remoteid, PKT_INT, c->localid,
4393 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4395 /* Remote side is trying to open a channel to talk to a
4396 * forwarded port. Give them back a local channel number. */
4397 struct ssh_channel *c;
4398 struct ssh_rportfwd pf, *pfp;
4403 c = snew(struct ssh_channel);
4406 remoteid = ssh_pkt_getuint32(pktin);
4407 ssh_pkt_getstring(pktin, &host, &hostsize);
4408 port = ssh_pkt_getuint32(pktin);
4410 if (hostsize >= lenof(pf.dhost))
4411 hostsize = lenof(pf.dhost)-1;
4412 memcpy(pf.dhost, host, hostsize);
4413 pf.dhost[hostsize] = '\0';
4415 pfp = find234(ssh->rportfwds, &pf, NULL);
4418 logeventf(ssh, "Rejected remote port open request for %s:%d",
4420 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4421 PKT_INT, remoteid, PKT_END);
4423 logeventf(ssh, "Received remote port open request for %s:%d",
4425 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4426 c, &ssh->cfg, pfp->pfrec->addressfamily);
4428 logeventf(ssh, "Port open failed: %s", e);
4430 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4431 PKT_INT, remoteid, PKT_END);
4433 c->remoteid = remoteid;
4434 c->halfopen = FALSE;
4435 c->localid = alloc_channel_id(ssh);
4437 c->v.v1.throttling = 0;
4438 c->type = CHAN_SOCKDATA; /* identify channel type */
4439 add234(ssh->channels, c);
4440 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4441 PKT_INT, c->remoteid, PKT_INT,
4442 c->localid, PKT_END);
4443 logevent("Forwarded port opened successfully");
4448 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4450 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4451 unsigned int localid = ssh_pkt_getuint32(pktin);
4452 struct ssh_channel *c;
4454 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4455 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4456 c->remoteid = localid;
4457 c->halfopen = FALSE;
4458 c->type = CHAN_SOCKDATA;
4459 c->v.v1.throttling = 0;
4460 pfd_confirm(c->u.pfd.s);
4463 if (c && c->closes) {
4465 * We have a pending close on this channel,
4466 * which we decided on before the server acked
4467 * the channel open. So now we know the
4468 * remoteid, we can close it again.
4470 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4471 PKT_INT, c->remoteid, PKT_END);
4475 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4477 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4478 struct ssh_channel *c;
4480 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4481 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4482 logevent("Forwarded connection refused by server");
4483 pfd_close(c->u.pfd.s);
4484 del234(ssh->channels, c);
4489 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4491 /* Remote side closes a channel. */
4492 unsigned i = ssh_pkt_getuint32(pktin);
4493 struct ssh_channel *c;
4494 c = find234(ssh->channels, &i, ssh_channelfind);
4495 if (c && !c->halfopen) {
4498 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4500 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4501 logevent("Forwarded X11 connection terminated");
4502 assert(c->u.x11.s != NULL);
4503 x11_close(c->u.x11.s);
4506 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4507 logevent("Forwarded port closed");
4508 assert(c->u.pfd.s != NULL);
4509 pfd_close(c->u.pfd.s);
4513 c->closes |= (closetype << 2); /* seen this message */
4514 if (!(c->closes & closetype)) {
4515 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4517 c->closes |= closetype; /* sent it too */
4520 if (c->closes == 15) {
4521 del234(ssh->channels, c);
4525 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4526 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4527 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4532 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4534 /* Data sent down one of our channels. */
4535 int i = ssh_pkt_getuint32(pktin);
4538 struct ssh_channel *c;
4540 ssh_pkt_getstring(pktin, &p, &len);
4542 c = find234(ssh->channels, &i, ssh_channelfind);
4547 bufsize = x11_send(c->u.x11.s, p, len);
4550 bufsize = pfd_send(c->u.pfd.s, p, len);
4553 /* Data for an agent message. Buffer it. */
4555 if (c->u.a.lensofar < 4) {
4556 unsigned int l = min(4 - c->u.a.lensofar, len);
4557 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4561 c->u.a.lensofar += l;
4563 if (c->u.a.lensofar == 4) {
4565 4 + GET_32BIT(c->u.a.msglen);
4566 c->u.a.message = snewn(c->u.a.totallen,
4568 memcpy(c->u.a.message, c->u.a.msglen, 4);
4570 if (c->u.a.lensofar >= 4 && len > 0) {
4572 min(c->u.a.totallen - c->u.a.lensofar,
4574 memcpy(c->u.a.message + c->u.a.lensofar, p,
4578 c->u.a.lensofar += l;
4580 if (c->u.a.lensofar == c->u.a.totallen) {
4583 if (agent_query(c->u.a.message,
4586 ssh_agentf_callback, c))
4587 ssh_agentf_callback(c, reply, replylen);
4588 sfree(c->u.a.message);
4589 c->u.a.lensofar = 0;
4592 bufsize = 0; /* agent channels never back up */
4595 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4596 c->v.v1.throttling = 1;
4597 ssh1_throttle(ssh, +1);
4602 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4604 ssh->exitcode = ssh_pkt_getuint32(pktin);
4605 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4606 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4608 * In case `helpful' firewalls or proxies tack
4609 * extra human-readable text on the end of the
4610 * session which we might mistake for another
4611 * encrypted packet, we close the session once
4612 * we've sent EXIT_CONFIRMATION.
4614 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4617 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4618 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4620 struct Packet *pktout = (struct Packet *)data;
4622 unsigned int arg = 0;
4623 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4624 if (i == lenof(ssh_ttymodes)) return;
4625 switch (ssh_ttymodes[i].type) {
4627 arg = ssh_tty_parse_specchar(val);
4630 arg = ssh_tty_parse_boolean(val);
4633 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4634 ssh2_pkt_addbyte(pktout, arg);
4638 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4639 struct Packet *pktin)
4641 crBegin(ssh->do_ssh1_connection_crstate);
4643 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4644 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4645 ssh1_smsg_stdout_stderr_data;
4647 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4648 ssh1_msg_channel_open_confirmation;
4649 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4650 ssh1_msg_channel_open_failure;
4651 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4652 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4653 ssh1_msg_channel_close;
4654 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4655 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4657 if (ssh->cfg.agentfwd && agent_exists()) {
4658 logevent("Requesting agent forwarding");
4659 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4663 if (pktin->type != SSH1_SMSG_SUCCESS
4664 && pktin->type != SSH1_SMSG_FAILURE) {
4665 bombout(("Protocol confusion"));
4667 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4668 logevent("Agent forwarding refused");
4670 logevent("Agent forwarding enabled");
4671 ssh->agentfwd_enabled = TRUE;
4672 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4676 if (ssh->cfg.x11_forward) {
4677 char proto[20], data[64];
4678 logevent("Requesting X11 forwarding");
4679 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4680 data, sizeof(data), ssh->cfg.x11_auth);
4681 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4683 * Note that while we blank the X authentication data here, we don't
4684 * take any special action to blank the start of an X11 channel,
4685 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4686 * without having session blanking enabled is likely to leak your
4687 * cookie into the log.
4689 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4690 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4692 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4693 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4696 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4698 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4703 if (pktin->type != SSH1_SMSG_SUCCESS
4704 && pktin->type != SSH1_SMSG_FAILURE) {
4705 bombout(("Protocol confusion"));
4707 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4708 logevent("X11 forwarding refused");
4710 logevent("X11 forwarding enabled");
4711 ssh->X11_fwd_enabled = TRUE;
4712 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4716 ssh_setup_portfwd(ssh, &ssh->cfg);
4717 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4719 if (!ssh->cfg.nopty) {
4721 /* Unpick the terminal-speed string. */
4722 /* XXX perhaps we should allow no speeds to be sent. */
4723 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4724 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4725 /* Send the pty request. */
4726 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4727 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4728 ssh_pkt_adduint32(pkt, ssh->term_height);
4729 ssh_pkt_adduint32(pkt, ssh->term_width);
4730 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4731 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4732 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4733 ssh1_send_ttymode, (void *)pkt);
4734 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4735 ssh_pkt_adduint32(pkt, ssh->ispeed);
4736 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4737 ssh_pkt_adduint32(pkt, ssh->ospeed);
4738 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4740 ssh->state = SSH_STATE_INTERMED;
4744 if (pktin->type != SSH1_SMSG_SUCCESS
4745 && pktin->type != SSH1_SMSG_FAILURE) {
4746 bombout(("Protocol confusion"));
4748 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4749 c_write_str(ssh, "Server refused to allocate pty\r\n");
4750 ssh->editing = ssh->echoing = 1;
4752 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4753 ssh->ospeed, ssh->ispeed);
4755 ssh->editing = ssh->echoing = 1;
4758 if (ssh->cfg.compression) {
4759 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4763 if (pktin->type != SSH1_SMSG_SUCCESS
4764 && pktin->type != SSH1_SMSG_FAILURE) {
4765 bombout(("Protocol confusion"));
4767 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4768 c_write_str(ssh, "Server refused to compress\r\n");
4770 logevent("Started compression");
4771 ssh->v1_compressing = TRUE;
4772 ssh->cs_comp_ctx = zlib_compress_init();
4773 logevent("Initialised zlib (RFC1950) compression");
4774 ssh->sc_comp_ctx = zlib_decompress_init();
4775 logevent("Initialised zlib (RFC1950) decompression");
4779 * Start the shell or command.
4781 * Special case: if the first-choice command is an SSH-2
4782 * subsystem (hence not usable here) and the second choice
4783 * exists, we fall straight back to that.
4786 char *cmd = ssh->cfg.remote_cmd_ptr;
4788 if (!cmd) cmd = ssh->cfg.remote_cmd;
4790 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4791 cmd = ssh->cfg.remote_cmd_ptr2;
4792 ssh->fallback_cmd = TRUE;
4795 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4797 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4798 logevent("Started session");
4801 ssh->state = SSH_STATE_SESSION;
4802 if (ssh->size_needed)
4803 ssh_size(ssh, ssh->term_width, ssh->term_height);
4804 if (ssh->eof_needed)
4805 ssh_special(ssh, TS_EOF);
4808 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4810 ssh->channels = newtree234(ssh_channelcmp);
4814 * By this point, most incoming packets are already being
4815 * handled by the dispatch table, and we need only pay
4816 * attention to the unusual ones.
4821 if (pktin->type == SSH1_SMSG_SUCCESS) {
4822 /* may be from EXEC_SHELL on some servers */
4823 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4824 /* may be from EXEC_SHELL on some servers
4825 * if no pty is available or in other odd cases. Ignore */
4827 bombout(("Strange packet received: type %d", pktin->type));
4832 int len = min(inlen, 512);
4833 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4834 PKT_INT, len, PKT_DATA, in, len,
4835 PKTT_OTHER, PKT_END);
4846 * Handle the top-level SSH-2 protocol.
4848 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4853 ssh_pkt_getstring(pktin, &msg, &msglen);
4854 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4857 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4859 /* log reason code in disconnect message */
4863 ssh_pkt_getstring(pktin, &msg, &msglen);
4864 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4867 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4869 /* Do nothing, because we're ignoring it! Duhh. */
4872 static void ssh1_protocol_setup(Ssh ssh)
4877 * Most messages are handled by the coroutines.
4879 for (i = 0; i < 256; i++)
4880 ssh->packet_dispatch[i] = NULL;
4883 * These special message types we install handlers for.
4885 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4886 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4887 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4890 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4891 struct Packet *pktin)
4893 unsigned char *in=(unsigned char*)vin;
4894 if (ssh->state == SSH_STATE_CLOSED)
4897 if (pktin && ssh->packet_dispatch[pktin->type]) {
4898 ssh->packet_dispatch[pktin->type](ssh, pktin);
4902 if (!ssh->protocol_initial_phase_done) {
4903 if (do_ssh1_login(ssh, in, inlen, pktin))
4904 ssh->protocol_initial_phase_done = TRUE;
4909 do_ssh1_connection(ssh, in, inlen, pktin);
4913 * Utility routine for decoding comma-separated strings in KEXINIT.
4915 static int in_commasep_string(char *needle, char *haystack, int haylen)
4918 if (!needle || !haystack) /* protect against null pointers */
4920 needlen = strlen(needle);
4923 * Is it at the start of the string?
4925 if (haylen >= needlen && /* haystack is long enough */
4926 !memcmp(needle, haystack, needlen) && /* initial match */
4927 (haylen == needlen || haystack[needlen] == ',')
4928 /* either , or EOS follows */
4932 * If not, search for the next comma and resume after that.
4933 * If no comma found, terminate.
4935 while (haylen > 0 && *haystack != ',')
4936 haylen--, haystack++;
4939 haylen--, haystack++; /* skip over comma itself */
4944 * Similar routine for checking whether we have the first string in a list.
4946 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4949 if (!needle || !haystack) /* protect against null pointers */
4951 needlen = strlen(needle);
4953 * Is it at the start of the string?
4955 if (haylen >= needlen && /* haystack is long enough */
4956 !memcmp(needle, haystack, needlen) && /* initial match */
4957 (haylen == needlen || haystack[needlen] == ',')
4958 /* either , or EOS follows */
4966 * SSH-2 key creation method.
4968 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
4969 unsigned char *keyspace)
4971 const struct ssh_hash *h = ssh->kex->hash;
4973 /* First hlen bytes. */
4975 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4976 hash_mpint(h, s, K);
4977 h->bytes(s, H, h->hlen);
4978 h->bytes(s, &chr, 1);
4979 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
4980 h->final(s, keyspace);
4981 /* Next hlen bytes. */
4983 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4984 hash_mpint(h, s, K);
4985 h->bytes(s, H, h->hlen);
4986 h->bytes(s, keyspace, h->hlen);
4987 h->final(s, keyspace + h->hlen);
4991 * Handle the SSH-2 transport layer.
4993 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4994 struct Packet *pktin)
4996 unsigned char *in = (unsigned char *)vin;
4997 struct do_ssh2_transport_state {
4998 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4999 Bignum p, g, e, f, K;
5002 int kex_init_value, kex_reply_value;
5003 const struct ssh_mac **maclist;
5005 const struct ssh2_cipher *cscipher_tobe;
5006 const struct ssh2_cipher *sccipher_tobe;
5007 const struct ssh_mac *csmac_tobe;
5008 const struct ssh_mac *scmac_tobe;
5009 const struct ssh_compress *cscomp_tobe;
5010 const struct ssh_compress *sccomp_tobe;
5011 char *hostkeydata, *sigdata, *keystr, *fingerprint;
5012 int hostkeylen, siglen;
5013 void *hkey; /* actual host key */
5014 unsigned char exchange_hash[32];
5015 int n_preferred_kex;
5016 const struct ssh_kexes *preferred_kex[KEX_MAX];
5017 int n_preferred_ciphers;
5018 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5019 const struct ssh_compress *preferred_comp;
5020 int got_session_id, activated_authconn;
5021 struct Packet *pktout;
5026 crState(do_ssh2_transport_state);
5028 crBegin(ssh->do_ssh2_transport_crstate);
5030 s->cscipher_tobe = s->sccipher_tobe = NULL;
5031 s->csmac_tobe = s->scmac_tobe = NULL;
5032 s->cscomp_tobe = s->sccomp_tobe = NULL;
5034 s->got_session_id = s->activated_authconn = FALSE;
5037 * Be prepared to work around the buggy MAC problem.
5039 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5040 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5042 s->maclist = macs, s->nmacs = lenof(macs);
5045 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
5047 int i, j, commalist_started;
5050 * Set up the preferred key exchange. (NULL => warn below here)
5052 s->n_preferred_kex = 0;
5053 for (i = 0; i < KEX_MAX; i++) {
5054 switch (ssh->cfg.ssh_kexlist[i]) {
5056 s->preferred_kex[s->n_preferred_kex++] =
5057 &ssh_diffiehellman_gex;
5060 s->preferred_kex[s->n_preferred_kex++] =
5061 &ssh_diffiehellman_group14;
5064 s->preferred_kex[s->n_preferred_kex++] =
5065 &ssh_diffiehellman_group1;
5068 /* Flag for later. Don't bother if it's the last in
5070 if (i < KEX_MAX - 1) {
5071 s->preferred_kex[s->n_preferred_kex++] = NULL;
5078 * Set up the preferred ciphers. (NULL => warn below here)
5080 s->n_preferred_ciphers = 0;
5081 for (i = 0; i < CIPHER_MAX; i++) {
5082 switch (ssh->cfg.ssh_cipherlist[i]) {
5083 case CIPHER_BLOWFISH:
5084 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5087 if (ssh->cfg.ssh2_des_cbc) {
5088 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5092 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5095 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5097 case CIPHER_ARCFOUR:
5098 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5101 /* Flag for later. Don't bother if it's the last in
5103 if (i < CIPHER_MAX - 1) {
5104 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5111 * Set up preferred compression.
5113 if (ssh->cfg.compression)
5114 s->preferred_comp = &ssh_zlib;
5116 s->preferred_comp = &ssh_comp_none;
5119 * Enable queueing of outgoing auth- or connection-layer
5120 * packets while we are in the middle of a key exchange.
5122 ssh->queueing = TRUE;
5125 * Flag that KEX is in progress.
5127 ssh->kex_in_progress = TRUE;
5130 * Construct and send our key exchange packet.
5132 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5133 for (i = 0; i < 16; i++)
5134 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5135 /* List key exchange algorithms. */
5136 ssh2_pkt_addstring_start(s->pktout);
5137 commalist_started = 0;
5138 for (i = 0; i < s->n_preferred_kex; i++) {
5139 const struct ssh_kexes *k = s->preferred_kex[i];
5140 if (!k) continue; /* warning flag */
5141 for (j = 0; j < k->nkexes; j++) {
5142 if (commalist_started)
5143 ssh2_pkt_addstring_str(s->pktout, ",");
5144 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5145 commalist_started = 1;
5148 /* List server host key algorithms. */
5149 ssh2_pkt_addstring_start(s->pktout);
5150 for (i = 0; i < lenof(hostkey_algs); i++) {
5151 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5152 if (i < lenof(hostkey_algs) - 1)
5153 ssh2_pkt_addstring_str(s->pktout, ",");
5155 /* List client->server encryption algorithms. */
5156 ssh2_pkt_addstring_start(s->pktout);
5157 commalist_started = 0;
5158 for (i = 0; i < s->n_preferred_ciphers; i++) {
5159 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5160 if (!c) continue; /* warning flag */
5161 for (j = 0; j < c->nciphers; j++) {
5162 if (commalist_started)
5163 ssh2_pkt_addstring_str(s->pktout, ",");
5164 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5165 commalist_started = 1;
5168 /* List server->client encryption algorithms. */
5169 ssh2_pkt_addstring_start(s->pktout);
5170 commalist_started = 0;
5171 for (i = 0; i < s->n_preferred_ciphers; i++) {
5172 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5173 if (!c) continue; /* warning flag */
5174 for (j = 0; j < c->nciphers; j++) {
5175 if (commalist_started)
5176 ssh2_pkt_addstring_str(s->pktout, ",");
5177 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5178 commalist_started = 1;
5181 /* List client->server MAC algorithms. */
5182 ssh2_pkt_addstring_start(s->pktout);
5183 for (i = 0; i < s->nmacs; i++) {
5184 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5185 if (i < s->nmacs - 1)
5186 ssh2_pkt_addstring_str(s->pktout, ",");
5188 /* List server->client MAC algorithms. */
5189 ssh2_pkt_addstring_start(s->pktout);
5190 for (i = 0; i < s->nmacs; i++) {
5191 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5192 if (i < s->nmacs - 1)
5193 ssh2_pkt_addstring_str(s->pktout, ",");
5195 /* List client->server compression algorithms. */
5196 ssh2_pkt_addstring_start(s->pktout);
5197 assert(lenof(compressions) > 1);
5198 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5199 for (i = 0; i < lenof(compressions); i++) {
5200 const struct ssh_compress *c = compressions[i];
5201 if (c != s->preferred_comp) {
5202 ssh2_pkt_addstring_str(s->pktout, ",");
5203 ssh2_pkt_addstring_str(s->pktout, c->name);
5206 /* List server->client compression algorithms. */
5207 ssh2_pkt_addstring_start(s->pktout);
5208 assert(lenof(compressions) > 1);
5209 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5210 for (i = 0; i < lenof(compressions); i++) {
5211 const struct ssh_compress *c = compressions[i];
5212 if (c != s->preferred_comp) {
5213 ssh2_pkt_addstring_str(s->pktout, ",");
5214 ssh2_pkt_addstring_str(s->pktout, c->name);
5217 /* List client->server languages. Empty list. */
5218 ssh2_pkt_addstring_start(s->pktout);
5219 /* List server->client languages. Empty list. */
5220 ssh2_pkt_addstring_start(s->pktout);
5221 /* First KEX packet does _not_ follow, because we're not that brave. */
5222 ssh2_pkt_addbool(s->pktout, FALSE);
5224 ssh2_pkt_adduint32(s->pktout, 0);
5227 s->our_kexinitlen = s->pktout->length - 5;
5228 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5229 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5231 ssh2_pkt_send_noqueue(ssh, s->pktout);
5237 * Now examine the other side's KEXINIT to see what we're up
5241 char *str, *preferred;
5244 if (pktin->type != SSH2_MSG_KEXINIT) {
5245 bombout(("expected key exchange packet from server"));
5249 ssh->hostkey = NULL;
5250 s->cscipher_tobe = NULL;
5251 s->sccipher_tobe = NULL;
5252 s->csmac_tobe = NULL;
5253 s->scmac_tobe = NULL;
5254 s->cscomp_tobe = NULL;
5255 s->sccomp_tobe = NULL;
5256 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5258 pktin->savedpos += 16; /* skip garbage cookie */
5259 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5262 for (i = 0; i < s->n_preferred_kex; i++) {
5263 const struct ssh_kexes *k = s->preferred_kex[i];
5267 for (j = 0; j < k->nkexes; j++) {
5268 if (!preferred) preferred = k->list[j]->name;
5269 if (in_commasep_string(k->list[j]->name, str, len)) {
5270 ssh->kex = k->list[j];
5279 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5280 str ? str : "(null)"));
5284 * Note that the server's guess is considered wrong if it doesn't match
5285 * the first algorithm in our list, even if it's still the algorithm
5288 s->guessok = first_in_commasep_string(preferred, str, len);
5289 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5290 for (i = 0; i < lenof(hostkey_algs); i++) {
5291 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5292 ssh->hostkey = hostkey_algs[i];
5296 s->guessok = s->guessok &&
5297 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5298 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5299 for (i = 0; i < s->n_preferred_ciphers; i++) {
5300 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5302 s->warn_cscipher = TRUE;
5304 for (j = 0; j < c->nciphers; j++) {
5305 if (in_commasep_string(c->list[j]->name, str, len)) {
5306 s->cscipher_tobe = c->list[j];
5311 if (s->cscipher_tobe)
5314 if (!s->cscipher_tobe) {
5315 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5316 str ? str : "(null)"));
5320 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5321 for (i = 0; i < s->n_preferred_ciphers; i++) {
5322 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5324 s->warn_sccipher = TRUE;
5326 for (j = 0; j < c->nciphers; j++) {
5327 if (in_commasep_string(c->list[j]->name, str, len)) {
5328 s->sccipher_tobe = c->list[j];
5333 if (s->sccipher_tobe)
5336 if (!s->sccipher_tobe) {
5337 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5338 str ? str : "(null)"));
5342 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5343 for (i = 0; i < s->nmacs; i++) {
5344 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5345 s->csmac_tobe = s->maclist[i];
5349 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5350 for (i = 0; i < s->nmacs; i++) {
5351 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5352 s->scmac_tobe = s->maclist[i];
5356 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5357 for (i = 0; i < lenof(compressions) + 1; i++) {
5358 const struct ssh_compress *c =
5359 i == 0 ? s->preferred_comp : compressions[i - 1];
5360 if (in_commasep_string(c->name, str, len)) {
5365 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5366 for (i = 0; i < lenof(compressions) + 1; i++) {
5367 const struct ssh_compress *c =
5368 i == 0 ? s->preferred_comp : compressions[i - 1];
5369 if (in_commasep_string(c->name, str, len)) {
5374 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5375 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5376 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5379 ssh_set_frozen(ssh, 1);
5380 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5382 ssh_dialog_callback, ssh);
5383 if (s->dlgret < 0) {
5387 bombout(("Unexpected data from server while"
5388 " waiting for user response"));
5391 } while (pktin || inlen > 0);
5392 s->dlgret = ssh->user_response;
5394 ssh_set_frozen(ssh, 0);
5395 if (s->dlgret == 0) {
5396 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5402 if (s->warn_cscipher) {
5403 ssh_set_frozen(ssh, 1);
5404 s->dlgret = askalg(ssh->frontend,
5405 "client-to-server cipher",
5406 s->cscipher_tobe->name,
5407 ssh_dialog_callback, ssh);
5408 if (s->dlgret < 0) {
5412 bombout(("Unexpected data from server while"
5413 " waiting for user response"));
5416 } while (pktin || inlen > 0);
5417 s->dlgret = ssh->user_response;
5419 ssh_set_frozen(ssh, 0);
5420 if (s->dlgret == 0) {
5421 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5427 if (s->warn_sccipher) {
5428 ssh_set_frozen(ssh, 1);
5429 s->dlgret = askalg(ssh->frontend,
5430 "server-to-client cipher",
5431 s->sccipher_tobe->name,
5432 ssh_dialog_callback, ssh);
5433 if (s->dlgret < 0) {
5437 bombout(("Unexpected data from server while"
5438 " waiting for user response"));
5441 } while (pktin || inlen > 0);
5442 s->dlgret = ssh->user_response;
5444 ssh_set_frozen(ssh, 0);
5445 if (s->dlgret == 0) {
5446 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5452 ssh->exhash = ssh->kex->hash->init();
5453 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5454 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5455 hash_string(ssh->kex->hash, ssh->exhash,
5456 s->our_kexinit, s->our_kexinitlen);
5457 sfree(s->our_kexinit);
5458 if (pktin->length > 5)
5459 hash_string(ssh->kex->hash, ssh->exhash,
5460 pktin->data + 5, pktin->length - 5);
5462 if (s->ignorepkt) /* first_kex_packet_follows */
5463 crWaitUntil(pktin); /* Ignore packet */
5467 * Work out the number of bits of key we will need from the key
5468 * exchange. We start with the maximum key length of either
5474 csbits = s->cscipher_tobe->keylen;
5475 scbits = s->sccipher_tobe->keylen;
5476 s->nbits = (csbits > scbits ? csbits : scbits);
5478 /* The keys only have hlen-bit entropy, since they're based on
5479 * a hash. So cap the key size at hlen bits. */
5480 if (s->nbits > ssh->kex->hash->hlen * 8)
5481 s->nbits = ssh->kex->hash->hlen * 8;
5484 * If we're doing Diffie-Hellman group exchange, start by
5485 * requesting a group.
5487 if (!ssh->kex->pdata) {
5488 logevent("Doing Diffie-Hellman group exchange");
5489 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5491 * Work out how big a DH group we will need to allow that
5494 s->pbits = 512 << ((s->nbits - 1) / 64);
5495 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5496 ssh2_pkt_adduint32(s->pktout, s->pbits);
5497 ssh2_pkt_send_noqueue(ssh, s->pktout);
5500 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5501 bombout(("expected key exchange group packet from server"));
5504 s->p = ssh2_pkt_getmp(pktin);
5505 s->g = ssh2_pkt_getmp(pktin);
5506 if (!s->p || !s->g) {
5507 bombout(("unable to read mp-ints from incoming group packet"));
5510 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5511 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5512 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5514 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5515 ssh->kex_ctx = dh_setup_group(ssh->kex);
5516 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5517 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5518 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5519 ssh->kex->groupname);
5522 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5523 ssh->kex->hash->text_name);
5525 * Now generate and send e for Diffie-Hellman.
5527 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5528 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5529 s->pktout = ssh2_pkt_init(s->kex_init_value);
5530 ssh2_pkt_addmp(s->pktout, s->e);
5531 ssh2_pkt_send_noqueue(ssh, s->pktout);
5533 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5535 if (pktin->type != s->kex_reply_value) {
5536 bombout(("expected key exchange reply packet from server"));
5539 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5540 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5541 s->f = ssh2_pkt_getmp(pktin);
5543 bombout(("unable to parse key exchange reply packet"));
5546 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5548 s->K = dh_find_K(ssh->kex_ctx, s->f);
5550 /* We assume everything from now on will be quick, and it might
5551 * involve user interaction. */
5552 set_busy_status(ssh->frontend, BUSY_NOT);
5554 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5555 if (!ssh->kex->pdata) {
5556 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5557 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5558 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5560 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5561 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5562 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
5563 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
5564 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
5566 dh_cleanup(ssh->kex_ctx);
5567 ssh->kex_ctx = NULL;
5570 debug(("Exchange hash is:\n"));
5571 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
5574 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5576 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5577 (char *)s->exchange_hash,
5578 ssh->kex->hash->hlen)) {
5579 bombout(("Server's host key did not match the signature supplied"));
5584 * Authenticate remote host: verify host key. (We've already
5585 * checked the signature of the exchange hash.)
5587 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5588 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5589 ssh_set_frozen(ssh, 1);
5590 s->dlgret = verify_ssh_host_key(ssh->frontend,
5591 ssh->savedhost, ssh->savedport,
5592 ssh->hostkey->keytype, s->keystr,
5594 ssh_dialog_callback, ssh);
5595 if (s->dlgret < 0) {
5599 bombout(("Unexpected data from server while waiting"
5600 " for user host key response"));
5603 } while (pktin || inlen > 0);
5604 s->dlgret = ssh->user_response;
5606 ssh_set_frozen(ssh, 0);
5607 if (s->dlgret == 0) {
5608 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5612 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5613 logevent("Host key fingerprint is:");
5614 logevent(s->fingerprint);
5616 sfree(s->fingerprint);
5618 ssh->hostkey->freekey(s->hkey);
5621 * The exchange hash from the very first key exchange is also
5622 * the session id, used in session key construction and
5625 if (!s->got_session_id) {
5626 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
5627 memcpy(ssh->v2_session_id, s->exchange_hash,
5628 sizeof(s->exchange_hash));
5629 ssh->v2_session_id_len = ssh->kex->hash->hlen;
5630 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
5631 s->got_session_id = TRUE;
5635 * Send SSH2_MSG_NEWKEYS.
5637 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5638 ssh2_pkt_send_noqueue(ssh, s->pktout);
5639 ssh->outgoing_data_size = 0; /* start counting from here */
5642 * We've sent client NEWKEYS, so create and initialise
5643 * client-to-server session keys.
5645 if (ssh->cs_cipher_ctx)
5646 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5647 ssh->cscipher = s->cscipher_tobe;
5648 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5650 if (ssh->cs_mac_ctx)
5651 ssh->csmac->free_context(ssh->cs_mac_ctx);
5652 ssh->csmac = s->csmac_tobe;
5653 ssh->cs_mac_ctx = ssh->csmac->make_context();
5655 if (ssh->cs_comp_ctx)
5656 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5657 ssh->cscomp = s->cscomp_tobe;
5658 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5661 * Set IVs on client-to-server keys. Here we use the exchange
5662 * hash from the _first_ key exchange.
5665 unsigned char keyspace[40];
5666 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
5667 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5668 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
5669 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5670 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
5671 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5674 logeventf(ssh, "Initialised %.200s client->server encryption",
5675 ssh->cscipher->text_name);
5676 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5677 ssh->csmac->text_name);
5678 if (ssh->cscomp->text_name)
5679 logeventf(ssh, "Initialised %s compression",
5680 ssh->cscomp->text_name);
5683 * Now our end of the key exchange is complete, we can send all
5684 * our queued higher-layer packets.
5686 ssh->queueing = FALSE;
5687 ssh2_pkt_queuesend(ssh);
5690 * Expect SSH2_MSG_NEWKEYS from server.
5693 if (pktin->type != SSH2_MSG_NEWKEYS) {
5694 bombout(("expected new-keys packet from server"));
5697 ssh->incoming_data_size = 0; /* start counting from here */
5700 * We've seen server NEWKEYS, so create and initialise
5701 * server-to-client session keys.
5703 if (ssh->sc_cipher_ctx)
5704 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5705 ssh->sccipher = s->sccipher_tobe;
5706 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5708 if (ssh->sc_mac_ctx)
5709 ssh->scmac->free_context(ssh->sc_mac_ctx);
5710 ssh->scmac = s->scmac_tobe;
5711 ssh->sc_mac_ctx = ssh->scmac->make_context();
5713 if (ssh->sc_comp_ctx)
5714 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5715 ssh->sccomp = s->sccomp_tobe;
5716 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5719 * Set IVs on server-to-client keys. Here we use the exchange
5720 * hash from the _first_ key exchange.
5723 unsigned char keyspace[40];
5724 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
5725 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5726 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
5727 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5728 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
5729 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5731 logeventf(ssh, "Initialised %.200s server->client encryption",
5732 ssh->sccipher->text_name);
5733 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5734 ssh->scmac->text_name);
5735 if (ssh->sccomp->text_name)
5736 logeventf(ssh, "Initialised %s decompression",
5737 ssh->sccomp->text_name);
5740 * Free key exchange data.
5744 if (!ssh->kex->pdata) {
5750 * Key exchange is over. Loop straight back round if we have a
5751 * deferred rekey reason.
5753 if (ssh->deferred_rekey_reason) {
5754 logevent(ssh->deferred_rekey_reason);
5756 ssh->deferred_rekey_reason = NULL;
5757 goto begin_key_exchange;
5761 * Otherwise, schedule a timer for our next rekey.
5763 ssh->kex_in_progress = FALSE;
5764 ssh->last_rekey = GETTICKCOUNT();
5765 if (ssh->cfg.ssh_rekey_time != 0)
5766 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5770 * If this is the first key exchange phase, we must pass the
5771 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5772 * wants to see it but because it will need time to initialise
5773 * itself before it sees an actual packet. In subsequent key
5774 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5775 * it would only confuse the layer above.
5777 if (s->activated_authconn) {
5780 s->activated_authconn = TRUE;
5783 * Now we're encrypting. Begin returning 1 to the protocol main
5784 * function so that other things can run on top of the
5785 * transport. If we ever see a KEXINIT, we must go back to the
5788 * We _also_ go back to the start if we see pktin==NULL and
5789 * inlen==-1, because this is a special signal meaning
5790 * `initiate client-driven rekey', and `in' contains a message
5791 * giving the reason for the rekey.
5793 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5794 (!pktin && inlen == -1))) {
5799 logevent("Server initiated key re-exchange");
5802 * Special case: if the server bug is set that doesn't
5803 * allow rekeying, we give a different log message and
5804 * continue waiting. (If such a server _initiates_ a rekey,
5805 * we process it anyway!)
5807 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5808 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5810 /* Reset the counters, so that at least this message doesn't
5811 * hit the event log _too_ often. */
5812 ssh->outgoing_data_size = 0;
5813 ssh->incoming_data_size = 0;
5814 if (ssh->cfg.ssh_rekey_time != 0) {
5816 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5819 goto wait_for_rekey; /* this is utterly horrid */
5821 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5824 goto begin_key_exchange;
5830 * Add data to an SSH-2 channel output buffer.
5832 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5835 bufchain_add(&c->v.v2.outbuffer, buf, len);
5839 * Attempt to send data on an SSH-2 channel.
5841 static int ssh2_try_send(struct ssh_channel *c)
5844 struct Packet *pktout;
5846 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5849 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5850 if ((unsigned)len > c->v.v2.remwindow)
5851 len = c->v.v2.remwindow;
5852 if ((unsigned)len > c->v.v2.remmaxpkt)
5853 len = c->v.v2.remmaxpkt;
5854 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5855 ssh2_pkt_adduint32(pktout, c->remoteid);
5856 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5857 ssh2_pkt_addstring_start(pktout);
5858 ssh2_pkt_addstring_data(pktout, data, len);
5859 end_log_omission(ssh, pktout);
5860 ssh2_pkt_send(ssh, pktout);
5861 bufchain_consume(&c->v.v2.outbuffer, len);
5862 c->v.v2.remwindow -= len;
5866 * After having sent as much data as we can, return the amount
5869 return bufchain_size(&c->v.v2.outbuffer);
5872 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5876 return; /* don't send on closing channels */
5877 bufsize = ssh2_try_send(c);
5880 case CHAN_MAINSESSION:
5881 /* stdin need not receive an unthrottle
5882 * notification since it will be polled */
5885 x11_unthrottle(c->u.x11.s);
5888 /* agent sockets are request/response and need no
5889 * buffer management */
5892 pfd_unthrottle(c->u.pfd.s);
5899 * Potentially enlarge the window on an SSH-2 channel.
5901 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5906 * Never send WINDOW_ADJUST for a channel that the remote side
5907 * already thinks it's closed; there's no point, since it won't
5908 * be sending any more data anyway.
5914 * Only send a WINDOW_ADJUST if there's significantly more window
5915 * available than the other end thinks there is. This saves us
5916 * sending a WINDOW_ADJUST for every character in a shell session.
5918 * "Significant" is arbitrarily defined as half the window size.
5920 if (newwin > c->v.v2.locwindow * 2) {
5921 struct Packet *pktout;
5923 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5924 ssh2_pkt_adduint32(pktout, c->remoteid);
5925 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5926 ssh2_pkt_send(ssh, pktout);
5927 c->v.v2.locwindow = newwin;
5931 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5933 unsigned i = ssh_pkt_getuint32(pktin);
5934 struct ssh_channel *c;
5935 c = find234(ssh->channels, &i, ssh_channelfind);
5936 if (c && !c->closes) {
5937 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5938 ssh2_try_send_and_unthrottle(c);
5942 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5946 unsigned i = ssh_pkt_getuint32(pktin);
5947 struct ssh_channel *c;
5948 c = find234(ssh->channels, &i, ssh_channelfind);
5950 return; /* nonexistent channel */
5951 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5952 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5953 return; /* extended but not stderr */
5954 ssh_pkt_getstring(pktin, &data, &length);
5957 c->v.v2.locwindow -= length;
5959 case CHAN_MAINSESSION:
5961 from_backend(ssh->frontend, pktin->type ==
5962 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5966 bufsize = x11_send(c->u.x11.s, data, length);
5969 bufsize = pfd_send(c->u.pfd.s, data, length);
5972 while (length > 0) {
5973 if (c->u.a.lensofar < 4) {
5974 unsigned int l = min(4 - c->u.a.lensofar, length);
5975 memcpy(c->u.a.msglen + c->u.a.lensofar,
5979 c->u.a.lensofar += l;
5981 if (c->u.a.lensofar == 4) {
5983 4 + GET_32BIT(c->u.a.msglen);
5984 c->u.a.message = snewn(c->u.a.totallen,
5986 memcpy(c->u.a.message, c->u.a.msglen, 4);
5988 if (c->u.a.lensofar >= 4 && length > 0) {
5990 min(c->u.a.totallen - c->u.a.lensofar,
5992 memcpy(c->u.a.message + c->u.a.lensofar,
5996 c->u.a.lensofar += l;
5998 if (c->u.a.lensofar == c->u.a.totallen) {
6001 if (agent_query(c->u.a.message,
6004 ssh_agentf_callback, c))
6005 ssh_agentf_callback(c, reply, replylen);
6006 sfree(c->u.a.message);
6007 c->u.a.lensofar = 0;
6014 * If we are not buffering too much data,
6015 * enlarge the window again at the remote side.
6017 if (bufsize < OUR_V2_WINSIZE)
6018 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
6022 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6024 unsigned i = ssh_pkt_getuint32(pktin);
6025 struct ssh_channel *c;
6027 c = find234(ssh->channels, &i, ssh_channelfind);
6029 return; /* nonexistent channel */
6031 if (c->type == CHAN_X11) {
6033 * Remote EOF on an X11 channel means we should
6034 * wrap up and close the channel ourselves.
6036 x11_close(c->u.x11.s);
6038 } else if (c->type == CHAN_AGENT) {
6040 } else if (c->type == CHAN_SOCKDATA) {
6041 pfd_close(c->u.pfd.s);
6046 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6048 unsigned i = ssh_pkt_getuint32(pktin);
6049 struct ssh_channel *c;
6050 struct Packet *pktout;
6052 c = find234(ssh->channels, &i, ssh_channelfind);
6053 if (!c || c->halfopen) {
6054 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6055 c ? "half-open" : "nonexistent", i));
6058 /* Do pre-close processing on the channel. */
6060 case CHAN_MAINSESSION:
6061 ssh->mainchan = NULL;
6062 update_specials_menu(ssh->frontend);
6065 if (c->u.x11.s != NULL)
6066 x11_close(c->u.x11.s);
6073 if (c->u.pfd.s != NULL)
6074 pfd_close(c->u.pfd.s);
6078 if (c->closes == 0) {
6079 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6080 ssh2_pkt_adduint32(pktout, c->remoteid);
6081 ssh2_pkt_send(ssh, pktout);
6083 del234(ssh->channels, c);
6084 bufchain_clear(&c->v.v2.outbuffer);
6088 * See if that was the last channel left open.
6089 * (This is only our termination condition if we're
6090 * not running in -N mode.)
6092 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6094 * We used to send SSH_MSG_DISCONNECT here,
6095 * because I'd believed that _every_ conforming
6096 * SSH-2 connection had to end with a disconnect
6097 * being sent by at least one side; apparently
6098 * I was wrong and it's perfectly OK to
6099 * unceremoniously slam the connection shut
6100 * when you're done, and indeed OpenSSH feels
6101 * this is more polite than sending a
6102 * DISCONNECT. So now we don't.
6104 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6108 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6110 unsigned i = ssh_pkt_getuint32(pktin);
6111 struct ssh_channel *c;
6112 struct Packet *pktout;
6114 c = find234(ssh->channels, &i, ssh_channelfind);
6116 return; /* nonexistent channel */
6117 if (c->type != CHAN_SOCKDATA_DORMANT)
6118 return; /* dunno why they're confirming this */
6119 c->remoteid = ssh_pkt_getuint32(pktin);
6120 c->halfopen = FALSE;
6121 c->type = CHAN_SOCKDATA;
6122 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6123 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6125 pfd_confirm(c->u.pfd.s);
6128 * We have a pending close on this channel,
6129 * which we decided on before the server acked
6130 * the channel open. So now we know the
6131 * remoteid, we can close it again.
6133 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6134 ssh2_pkt_adduint32(pktout, c->remoteid);
6135 ssh2_pkt_send(ssh, pktout);
6139 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6141 static const char *const reasons[] = {
6142 "<unknown reason code>",
6143 "Administratively prohibited",
6145 "Unknown channel type",
6146 "Resource shortage",
6148 unsigned i = ssh_pkt_getuint32(pktin);
6149 unsigned reason_code;
6150 char *reason_string;
6152 struct ssh_channel *c;
6153 c = find234(ssh->channels, &i, ssh_channelfind);
6155 return; /* nonexistent channel */
6156 if (c->type != CHAN_SOCKDATA_DORMANT)
6157 return; /* dunno why they're failing this */
6159 reason_code = ssh_pkt_getuint32(pktin);
6160 if (reason_code >= lenof(reasons))
6161 reason_code = 0; /* ensure reasons[reason_code] in range */
6162 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6163 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6164 reasons[reason_code], reason_length, reason_string);
6166 pfd_close(c->u.pfd.s);
6168 del234(ssh->channels, c);
6172 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6176 int typelen, want_reply;
6177 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6178 struct ssh_channel *c;
6179 struct Packet *pktout;
6181 localid = ssh_pkt_getuint32(pktin);
6182 ssh_pkt_getstring(pktin, &type, &typelen);
6183 want_reply = ssh2_pkt_getbool(pktin);
6186 * First, check that the channel exists. Otherwise,
6187 * we can instantly disconnect with a rude message.
6189 c = find234(ssh->channels, &localid, ssh_channelfind);
6191 char *buf = dupprintf("Received channel request for nonexistent"
6192 " channel %d", localid);
6193 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6199 * Having got the channel number, we now look at
6200 * the request type string to see if it's something
6203 if (c == ssh->mainchan) {
6205 * We recognise "exit-status" and "exit-signal" on
6206 * the primary channel.
6208 if (typelen == 11 &&
6209 !memcmp(type, "exit-status", 11)) {
6211 ssh->exitcode = ssh_pkt_getuint32(pktin);
6212 logeventf(ssh, "Server sent command exit status %d",
6214 reply = SSH2_MSG_CHANNEL_SUCCESS;
6216 } else if (typelen == 11 &&
6217 !memcmp(type, "exit-signal", 11)) {
6219 int is_plausible = TRUE, is_int = FALSE;
6220 char *fmt_sig = "", *fmt_msg = "";
6222 int msglen = 0, core = FALSE;
6223 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6224 * provide an `int' for the signal, despite its
6225 * having been a `string' in the drafts since at
6226 * least 2001. (Fixed in session.c 1.147.) Try to
6227 * infer which we can safely parse it as. */
6229 unsigned char *p = pktin->body +
6231 long len = pktin->length - pktin->savedpos;
6232 unsigned long num = GET_32BIT(p); /* what is it? */
6233 /* If it's 0, it hardly matters; assume string */
6237 int maybe_int = FALSE, maybe_str = FALSE;
6238 #define CHECK_HYPOTHESIS(offset, result) \
6241 if (q >= 0 && q+4 <= len) { \
6242 q = q + 4 + GET_32BIT(p+q); \
6243 if (q >= 0 && q+4 <= len && \
6244 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6248 CHECK_HYPOTHESIS(4+1, maybe_int);
6249 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6250 #undef CHECK_HYPOTHESIS
6251 if (maybe_int && !maybe_str)
6253 else if (!maybe_int && maybe_str)
6256 /* Crikey. Either or neither. Panic. */
6257 is_plausible = FALSE;
6262 /* Old non-standard OpenSSH. */
6263 int signum = ssh_pkt_getuint32(pktin);
6264 fmt_sig = dupprintf(" %d", signum);
6266 /* As per the drafts. */
6269 ssh_pkt_getstring(pktin, &sig, &siglen);
6270 /* Signal name isn't supposed to be blank, but
6271 * let's cope gracefully if it is. */
6273 fmt_sig = dupprintf(" \"%.*s\"",
6277 core = ssh2_pkt_getbool(pktin);
6278 ssh_pkt_getstring(pktin, &msg, &msglen);
6280 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6282 /* ignore lang tag */
6283 } /* else don't attempt to parse */
6284 logeventf(ssh, "Server exited on signal%s%s%s",
6285 fmt_sig, core ? " (core dumped)" : "",
6287 if (*fmt_sig) sfree(fmt_sig);
6288 if (*fmt_msg) sfree(fmt_msg);
6289 reply = SSH2_MSG_CHANNEL_SUCCESS;
6294 * This is a channel request we don't know
6295 * about, so we now either ignore the request
6296 * or respond with CHANNEL_FAILURE, depending
6299 reply = SSH2_MSG_CHANNEL_FAILURE;
6302 pktout = ssh2_pkt_init(reply);
6303 ssh2_pkt_adduint32(pktout, c->remoteid);
6304 ssh2_pkt_send(ssh, pktout);
6308 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6311 int typelen, want_reply;
6312 struct Packet *pktout;
6314 ssh_pkt_getstring(pktin, &type, &typelen);
6315 want_reply = ssh2_pkt_getbool(pktin);
6318 * We currently don't support any global requests
6319 * at all, so we either ignore the request or
6320 * respond with REQUEST_FAILURE, depending on
6324 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6325 ssh2_pkt_send(ssh, pktout);
6329 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6337 struct ssh_channel *c;
6338 unsigned remid, winsize, pktsize;
6339 struct Packet *pktout;
6341 ssh_pkt_getstring(pktin, &type, &typelen);
6342 c = snew(struct ssh_channel);
6345 remid = ssh_pkt_getuint32(pktin);
6346 winsize = ssh_pkt_getuint32(pktin);
6347 pktsize = ssh_pkt_getuint32(pktin);
6349 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6352 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6353 addrstr = snewn(peeraddrlen+1, char);
6354 memcpy(addrstr, peeraddr, peeraddrlen);
6355 addrstr[peeraddrlen] = '\0';
6356 peerport = ssh_pkt_getuint32(pktin);
6358 logeventf(ssh, "Received X11 connect request from %s:%d",
6361 if (!ssh->X11_fwd_enabled)
6362 error = "X11 forwarding is not enabled";
6363 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6364 ssh->x11auth, addrstr, peerport,
6365 &ssh->cfg) != NULL) {
6366 error = "Unable to open an X11 connection";
6368 logevent("Opening X11 forward connection succeeded");
6373 } else if (typelen == 15 &&
6374 !memcmp(type, "forwarded-tcpip", 15)) {
6375 struct ssh_rportfwd pf, *realpf;
6378 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6379 pf.sport = ssh_pkt_getuint32(pktin);
6380 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6381 peerport = ssh_pkt_getuint32(pktin);
6382 realpf = find234(ssh->rportfwds, &pf, NULL);
6383 logeventf(ssh, "Received remote port %d open request "
6384 "from %s:%d", pf.sport, peeraddr, peerport);
6385 if (realpf == NULL) {
6386 error = "Remote port is not recognised";
6388 const char *e = pfd_newconnect(&c->u.pfd.s,
6392 realpf->pfrec->addressfamily);
6393 logeventf(ssh, "Attempting to forward remote port to "
6394 "%s:%d", realpf->dhost, realpf->dport);
6396 logeventf(ssh, "Port open failed: %s", e);
6397 error = "Port open failed";
6399 logevent("Forwarded port opened successfully");
6400 c->type = CHAN_SOCKDATA;
6403 } else if (typelen == 22 &&
6404 !memcmp(type, "auth-agent@openssh.com", 22)) {
6405 if (!ssh->agentfwd_enabled)
6406 error = "Agent forwarding is not enabled";
6408 c->type = CHAN_AGENT; /* identify channel type */
6409 c->u.a.lensofar = 0;
6412 error = "Unsupported channel type requested";
6415 c->remoteid = remid;
6416 c->halfopen = FALSE;
6418 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6419 ssh2_pkt_adduint32(pktout, c->remoteid);
6420 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6421 ssh2_pkt_addstring(pktout, error);
6422 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6423 ssh2_pkt_send(ssh, pktout);
6424 logeventf(ssh, "Rejected channel open: %s", error);
6427 c->localid = alloc_channel_id(ssh);
6429 c->v.v2.locwindow = OUR_V2_WINSIZE;
6430 c->v.v2.remwindow = winsize;
6431 c->v.v2.remmaxpkt = pktsize;
6432 bufchain_init(&c->v.v2.outbuffer);
6433 add234(ssh->channels, c);
6434 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6435 ssh2_pkt_adduint32(pktout, c->remoteid);
6436 ssh2_pkt_adduint32(pktout, c->localid);
6437 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6438 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6439 ssh2_pkt_send(ssh, pktout);
6444 * Buffer banner messages for later display at some convenient point.
6446 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6448 /* Arbitrary limit to prevent unbounded inflation of buffer */
6449 if (bufchain_size(&ssh->banner) <= 131072) {
6450 char *banner = NULL;
6452 ssh_pkt_getstring(pktin, &banner, &size);
6454 bufchain_add(&ssh->banner, banner, size);
6458 /* Helper function to deal with sending tty modes for "pty-req" */
6459 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6461 struct Packet *pktout = (struct Packet *)data;
6463 unsigned int arg = 0;
6464 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6465 if (i == lenof(ssh_ttymodes)) return;
6466 switch (ssh_ttymodes[i].type) {
6468 arg = ssh_tty_parse_specchar(val);
6471 arg = ssh_tty_parse_boolean(val);
6474 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6475 ssh2_pkt_adduint32(pktout, arg);
6479 * Handle the SSH-2 userauth and connection layers.
6481 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6482 struct Packet *pktin)
6484 struct do_ssh2_authconn_state {
6487 AUTH_TYPE_PUBLICKEY,
6488 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6489 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6491 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6492 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6494 int done_service_req;
6495 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6496 int tried_pubkey_config, done_agent;
6497 int kbd_inter_refused;
6499 prompts_t *cur_prompt;
6504 void *publickey_blob;
6505 int publickey_bloblen;
6506 int publickey_encrypted;
6507 char *publickey_algorithm;
6508 char *publickey_comment;
6509 unsigned char agent_request[5], *agent_response, *agentp;
6510 int agent_responselen;
6511 unsigned char *pkblob_in_agent;
6513 char *pkblob, *alg, *commentp;
6514 int pklen, alglen, commentlen;
6515 int siglen, retlen, len;
6516 char *q, *agentreq, *ret;
6518 int num_env, env_left, env_ok;
6519 struct Packet *pktout;
6521 crState(do_ssh2_authconn_state);
6523 crBegin(ssh->do_ssh2_authconn_crstate);
6525 s->done_service_req = FALSE;
6526 s->we_are_in = FALSE;
6527 if (!ssh->cfg.ssh_no_userauth) {
6529 * Request userauth protocol, and await a response to it.
6531 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6532 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6533 ssh2_pkt_send(ssh, s->pktout);
6534 crWaitUntilV(pktin);
6535 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6536 s->done_service_req = TRUE;
6538 if (!s->done_service_req) {
6540 * Request connection protocol directly, without authentication.
6542 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6543 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6544 ssh2_pkt_send(ssh, s->pktout);
6545 crWaitUntilV(pktin);
6546 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6547 s->we_are_in = TRUE; /* no auth required */
6549 bombout(("Server refused service request"));
6554 /* Arrange to be able to deal with any BANNERs that come in.
6555 * (We do this now as packets may come in during the next bit.) */
6556 bufchain_init(&ssh->banner);
6557 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6558 ssh2_msg_userauth_banner;
6561 * Misc one-time setup for authentication.
6563 s->publickey_blob = NULL;
6564 if (!s->we_are_in) {
6567 * Load the public half of any configured public key file
6570 if (!filename_is_null(ssh->cfg.keyfile)) {
6572 logeventf(ssh, "Reading private key file \"%.150s\"",
6573 filename_to_str(&ssh->cfg.keyfile));
6574 keytype = key_type(&ssh->cfg.keyfile);
6575 if (keytype == SSH_KEYTYPE_SSH2) {
6578 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6579 &s->publickey_algorithm,
6580 &s->publickey_bloblen,
6581 &s->publickey_comment, &error);
6582 if (s->publickey_blob) {
6583 s->publickey_encrypted =
6584 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
6587 logeventf(ssh, "Unable to load private key (%s)",
6589 msgbuf = dupprintf("Unable to load private key file "
6590 "\"%.150s\" (%s)\r\n",
6591 filename_to_str(&ssh->cfg.keyfile),
6593 c_write_str(ssh, msgbuf);
6598 logeventf(ssh, "Unable to use this key file (%s)",
6599 key_type_to_str(keytype));
6600 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6602 filename_to_str(&ssh->cfg.keyfile),
6603 key_type_to_str(keytype));
6604 c_write_str(ssh, msgbuf);
6606 s->publickey_blob = NULL;
6611 * Find out about any keys Pageant has (but if there's a
6612 * public key configured, filter out all others).
6615 s->agent_response = NULL;
6616 s->pkblob_in_agent = NULL;
6617 if (ssh->cfg.tryagent && agent_exists()) {
6621 logevent("Pageant is running. Requesting keys.");
6623 /* Request the keys held by the agent. */
6624 PUT_32BIT(s->agent_request, 1);
6625 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6626 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
6627 ssh_agent_callback, ssh)) {
6631 bombout(("Unexpected data from server while"
6632 " waiting for agent response"));
6635 } while (pktin || inlen > 0);
6636 r = ssh->agent_response;
6637 s->agent_responselen = ssh->agent_response_len;
6639 s->agent_response = (unsigned char *) r;
6640 if (s->agent_response && s->agent_responselen >= 5 &&
6641 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6644 p = s->agent_response + 5;
6645 s->nkeys = GET_32BIT(p);
6647 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6648 if (s->publickey_blob) {
6649 /* See if configured key is in agent. */
6650 for (keyi = 0; keyi < s->nkeys; keyi++) {
6651 s->pklen = GET_32BIT(p);
6652 if (s->pklen == s->publickey_bloblen &&
6653 !memcmp(p+4, s->publickey_blob,
6654 s->publickey_bloblen)) {
6655 logeventf(ssh, "Pageant key #%d matches "
6656 "configured key file", keyi);
6658 s->pkblob_in_agent = p;
6662 p += GET_32BIT(p) + 4; /* comment */
6664 if (!s->pkblob_in_agent) {
6665 logevent("Configured key file not in Pageant");
6675 * We repeat this whole loop, including the username prompt,
6676 * until we manage a successful authentication. If the user
6677 * types the wrong _password_, they can be sent back to the
6678 * beginning to try another username, if this is configured on.
6679 * (If they specify a username in the config, they are never
6680 * asked, even if they do give a wrong password.)
6682 * I think this best serves the needs of
6684 * - the people who have no configuration, no keys, and just
6685 * want to try repeated (username,password) pairs until they
6686 * type both correctly
6688 * - people who have keys and configuration but occasionally
6689 * need to fall back to passwords
6691 * - people with a key held in Pageant, who might not have
6692 * logged in to a particular machine before; so they want to
6693 * type a username, and then _either_ their key will be
6694 * accepted, _or_ they will type a password. If they mistype
6695 * the username they will want to be able to get back and
6698 s->username[0] = '\0';
6699 s->got_username = FALSE;
6700 while (!s->we_are_in) {
6704 if (s->got_username && !ssh->cfg.change_username) {
6706 * We got a username last time round this loop, and
6707 * with change_username turned off we don't try to get
6710 } else if (!*ssh->cfg.username) {
6711 int ret; /* need not be kept over crReturn */
6712 s->cur_prompt = new_prompts(ssh->frontend);
6713 s->cur_prompt->to_server = TRUE;
6714 s->cur_prompt->name = dupstr("SSH login name");
6715 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
6716 lenof(s->username));
6717 ret = get_userpass_input(s->cur_prompt, NULL, 0);
6720 crWaitUntilV(!pktin);
6721 ret = get_userpass_input(s->cur_prompt, in, inlen);
6726 * get_userpass_input() failed to get a username.
6729 free_prompts(s->cur_prompt);
6730 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
6733 memcpy(s->username, s->cur_prompt->prompts[0]->result,
6734 lenof(s->username));
6735 free_prompts(s->cur_prompt);
6738 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6739 s->username[sizeof(s->username)-1] = '\0';
6740 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6741 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6742 c_write_str(ssh, stuff);
6746 s->got_username = TRUE;
6749 * Send an authentication request using method "none": (a)
6750 * just in case it succeeds, and (b) so that we know what
6751 * authentication methods we can usefully try next.
6753 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6755 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6756 ssh2_pkt_addstring(s->pktout, s->username);
6757 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6758 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6759 ssh2_pkt_send(ssh, s->pktout);
6760 s->type = AUTH_TYPE_NONE;
6762 s->we_are_in = FALSE;
6764 s->tried_pubkey_config = FALSE;
6765 s->kbd_inter_refused = FALSE;
6767 /* Reset agent request state. */
6768 s->done_agent = FALSE;
6769 if (s->agent_response) {
6770 if (s->pkblob_in_agent) {
6771 s->agentp = s->pkblob_in_agent;
6773 s->agentp = s->agent_response + 5 + 4;
6780 * Wait for the result of the last authentication request.
6783 crWaitUntilV(pktin);
6785 * Now is a convenient point to spew any banner material
6786 * that we've accumulated. (This should ensure that when
6787 * we exit the auth loop, we haven't any left to deal
6791 int size = bufchain_size(&ssh->banner);
6793 * Don't show the banner if we're operating in
6794 * non-verbose non-interactive mode. (It's probably
6795 * a script, which means nobody will read the
6796 * banner _anyway_, and moreover the printing of
6797 * the banner will screw up processing on the
6798 * output of (say) plink.)
6800 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
6801 char *banner = snewn(size, char);
6802 bufchain_fetch(&ssh->banner, banner, size);
6803 c_write_untrusted(ssh, banner, size);
6806 bufchain_clear(&ssh->banner);
6808 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6809 logevent("Access granted");
6810 s->we_are_in = TRUE;
6814 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6815 bombout(("Strange packet received during authentication: "
6816 "type %d", pktin->type));
6823 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6824 * we can look at the string in it and know what we can
6825 * helpfully try next.
6827 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6830 ssh_pkt_getstring(pktin, &methods, &methlen);
6831 if (!ssh2_pkt_getbool(pktin)) {
6833 * We have received an unequivocal Access
6834 * Denied. This can translate to a variety of
6837 * - if we'd just tried "none" authentication,
6838 * it's not worth printing anything at all
6840 * - if we'd just tried a public key _offer_,
6841 * the message should be "Server refused our
6842 * key" (or no message at all if the key
6843 * came from Pageant)
6845 * - if we'd just tried anything else, the
6846 * message really should be "Access denied".
6848 * Additionally, if we'd just tried password
6849 * authentication, we should break out of this
6850 * whole loop so as to go back to the username
6851 * prompt (iff we're configured to allow
6852 * username change attempts).
6854 if (s->type == AUTH_TYPE_NONE) {
6856 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6857 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6858 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6859 c_write_str(ssh, "Server refused our key\r\n");
6860 logevent("Server refused public key");
6861 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6862 /* server declined keyboard-interactive; ignore */
6864 c_write_str(ssh, "Access denied\r\n");
6865 logevent("Access denied");
6866 if (s->type == AUTH_TYPE_PASSWORD &&
6867 ssh->cfg.change_username) {
6868 /* XXX perhaps we should allow
6869 * keyboard-interactive to do this too? */
6870 s->we_are_in = FALSE;
6875 c_write_str(ssh, "Further authentication required\r\n");
6876 logevent("Further authentication required");
6880 in_commasep_string("publickey", methods, methlen);
6882 in_commasep_string("password", methods, methlen);
6883 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6884 in_commasep_string("keyboard-interactive", methods, methlen);
6887 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6889 if (s->can_pubkey && !s->done_agent && s->nkeys) {
6892 * Attempt public-key authentication using a key from Pageant.
6895 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6896 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6898 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6900 /* Unpack key from agent response */
6901 s->pklen = GET_32BIT(s->agentp);
6903 s->pkblob = (char *)s->agentp;
6904 s->agentp += s->pklen;
6905 s->alglen = GET_32BIT(s->pkblob);
6906 s->alg = s->pkblob + 4;
6907 s->commentlen = GET_32BIT(s->agentp);
6909 s->commentp = (char *)s->agentp;
6910 s->agentp += s->commentlen;
6911 /* s->agentp now points at next key, if any */
6913 /* See if server will accept it */
6914 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6915 ssh2_pkt_addstring(s->pktout, s->username);
6916 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6917 /* service requested */
6918 ssh2_pkt_addstring(s->pktout, "publickey");
6920 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6921 ssh2_pkt_addstring_start(s->pktout);
6922 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6923 ssh2_pkt_addstring_start(s->pktout);
6924 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6925 ssh2_pkt_send(ssh, s->pktout);
6926 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
6928 crWaitUntilV(pktin);
6929 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6931 /* Offer of key refused. */
6938 if (flags & FLAG_VERBOSE) {
6939 c_write_str(ssh, "Authenticating with "
6941 c_write(ssh, s->commentp, s->commentlen);
6942 c_write_str(ssh, "\" from agent\r\n");
6946 * Server is willing to accept the key.
6947 * Construct a SIGN_REQUEST.
6949 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6950 ssh2_pkt_addstring(s->pktout, s->username);
6951 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6952 /* service requested */
6953 ssh2_pkt_addstring(s->pktout, "publickey");
6955 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
6956 ssh2_pkt_addstring_start(s->pktout);
6957 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6958 ssh2_pkt_addstring_start(s->pktout);
6959 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6961 /* Ask agent for signature. */
6962 s->siglen = s->pktout->length - 5 + 4 +
6963 ssh->v2_session_id_len;
6964 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6966 s->len = 1; /* message type */
6967 s->len += 4 + s->pklen; /* key blob */
6968 s->len += 4 + s->siglen; /* data to sign */
6969 s->len += 4; /* flags */
6970 s->agentreq = snewn(4 + s->len, char);
6971 PUT_32BIT(s->agentreq, s->len);
6972 s->q = s->agentreq + 4;
6973 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6974 PUT_32BIT(s->q, s->pklen);
6976 memcpy(s->q, s->pkblob, s->pklen);
6978 PUT_32BIT(s->q, s->siglen);
6980 /* Now the data to be signed... */
6981 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6982 PUT_32BIT(s->q, ssh->v2_session_id_len);
6985 memcpy(s->q, ssh->v2_session_id,
6986 ssh->v2_session_id_len);
6987 s->q += ssh->v2_session_id_len;
6988 memcpy(s->q, s->pktout->data + 5,
6989 s->pktout->length - 5);
6990 s->q += s->pktout->length - 5;
6991 /* And finally the (zero) flags word. */
6993 if (!agent_query(s->agentreq, s->len + 4,
6995 ssh_agent_callback, ssh)) {
6999 bombout(("Unexpected data from server"
7000 " while waiting for agent"
7004 } while (pktin || inlen > 0);
7005 vret = ssh->agent_response;
7006 s->retlen = ssh->agent_response_len;
7011 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7012 logevent("Sending Pageant's response");
7013 ssh2_add_sigblob(ssh, s->pktout,
7014 s->pkblob, s->pklen,
7016 GET_32BIT(s->ret + 5));
7017 ssh2_pkt_send(ssh, s->pktout);
7018 s->type = AUTH_TYPE_PUBLICKEY;
7020 /* FIXME: less drastic response */
7021 bombout(("Pageant failed to answer challenge"));
7027 /* Do we have any keys left to try? */
7028 if (s->pkblob_in_agent) {
7029 s->done_agent = TRUE;
7030 s->tried_pubkey_config = TRUE;
7033 if (s->keyi >= s->nkeys)
7034 s->done_agent = TRUE;
7037 } else if (s->can_pubkey && s->publickey_blob &&
7038 !s->tried_pubkey_config) {
7040 struct ssh2_userkey *key; /* not live over crReturn */
7041 char *passphrase; /* not live over crReturn */
7043 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7044 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
7046 s->tried_pubkey_config = TRUE;
7049 * Try the public key supplied in the configuration.
7051 * First, offer the public blob to see if the server is
7052 * willing to accept it.
7054 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7055 ssh2_pkt_addstring(s->pktout, s->username);
7056 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7057 /* service requested */
7058 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7059 ssh2_pkt_addbool(s->pktout, FALSE);
7060 /* no signature included */
7061 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7062 ssh2_pkt_addstring_start(s->pktout);
7063 ssh2_pkt_addstring_data(s->pktout,
7064 (char *)s->publickey_blob,
7065 s->publickey_bloblen);
7066 ssh2_pkt_send(ssh, s->pktout);
7067 logevent("Offered public key");
7069 crWaitUntilV(pktin);
7070 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7071 /* Key refused. Give up. */
7072 s->gotit = TRUE; /* reconsider message next loop */
7073 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7074 continue; /* process this new message */
7076 logevent("Offer of public key accepted");
7079 * Actually attempt a serious authentication using
7082 if (flags & FLAG_VERBOSE) {
7083 c_write_str(ssh, "Authenticating with public key \"");
7084 c_write_str(ssh, s->publickey_comment);
7085 c_write_str(ssh, "\"\r\n");
7089 const char *error; /* not live over crReturn */
7090 if (s->publickey_encrypted) {
7092 * Get a passphrase from the user.
7094 int ret; /* need not be kept over crReturn */
7095 s->cur_prompt = new_prompts(ssh->frontend);
7096 s->cur_prompt->to_server = FALSE;
7097 s->cur_prompt->name = dupstr("SSH key passphrase");
7098 add_prompt(s->cur_prompt,
7099 dupprintf("Passphrase for key \"%.100s\": ",
7100 s->publickey_comment),
7101 FALSE, SSH_MAX_PASSWORD_LEN);
7102 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7105 crWaitUntilV(!pktin);
7106 ret = get_userpass_input(s->cur_prompt,
7111 /* Failed to get a passphrase. Terminate. */
7112 free_prompts(s->cur_prompt);
7113 ssh_disconnect(ssh, NULL,
7114 "Unable to authenticate",
7115 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7120 dupstr(s->cur_prompt->prompts[0]->result);
7121 free_prompts(s->cur_prompt);
7123 passphrase = NULL; /* no passphrase needed */
7127 * Try decrypting the key.
7129 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7132 /* burn the evidence */
7133 memset(passphrase, 0, strlen(passphrase));
7136 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7138 (key == SSH2_WRONG_PASSPHRASE)) {
7139 c_write_str(ssh, "Wrong passphrase\r\n");
7141 /* and loop again */
7143 c_write_str(ssh, "Unable to load private key (");
7144 c_write_str(ssh, error);
7145 c_write_str(ssh, ")\r\n");
7147 break; /* try something else */
7153 unsigned char *pkblob, *sigblob, *sigdata;
7154 int pkblob_len, sigblob_len, sigdata_len;
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.
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");
7165 /* service requested */
7166 ssh2_pkt_addstring(s->pktout, "publickey");
7168 ssh2_pkt_addbool(s->pktout, TRUE);
7169 /* signature follows */
7170 ssh2_pkt_addstring(s->pktout, key->alg->name);
7171 pkblob = key->alg->public_blob(key->data,
7173 ssh2_pkt_addstring_start(s->pktout);
7174 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7178 * The data to be signed is:
7182 * followed by everything so far placed in the
7185 sigdata_len = s->pktout->length - 5 + 4 +
7186 ssh->v2_session_id_len;
7187 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7189 sigdata = snewn(sigdata_len, unsigned char);
7191 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7192 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7195 memcpy(sigdata+p, ssh->v2_session_id,
7196 ssh->v2_session_id_len);
7197 p += ssh->v2_session_id_len;
7198 memcpy(sigdata+p, s->pktout->data + 5,
7199 s->pktout->length - 5);
7200 p += s->pktout->length - 5;
7201 assert(p == sigdata_len);
7202 sigblob = key->alg->sign(key->data, (char *)sigdata,
7203 sigdata_len, &sigblob_len);
7204 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7205 sigblob, sigblob_len);
7210 ssh2_pkt_send(ssh, s->pktout);
7211 s->type = AUTH_TYPE_PUBLICKEY;
7212 key->alg->freekey(key->data);
7215 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
7218 * Keyboard-interactive authentication.
7221 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7223 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7224 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7226 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7227 ssh2_pkt_addstring(s->pktout, s->username);
7228 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7229 /* service requested */
7230 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
7232 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7233 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
7234 ssh2_pkt_send(ssh, s->pktout);
7236 crWaitUntilV(pktin);
7237 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7238 /* Server is not willing to do keyboard-interactive
7239 * at all (or, bizarrely but legally, accepts the
7240 * user without actually issuing any prompts).
7241 * Give up on it entirely. */
7243 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7244 logevent("Keyboard-interactive authentication refused");
7245 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7246 s->kbd_inter_refused = TRUE; /* don't try it again */
7251 * Loop while the server continues to send INFO_REQUESTs.
7253 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
7255 char *name, *inst, *lang;
7256 int name_len, inst_len, lang_len;
7260 * We've got a fresh USERAUTH_INFO_REQUEST.
7261 * Get the preamble and start building a prompt.
7263 ssh_pkt_getstring(pktin, &name, &name_len);
7264 ssh_pkt_getstring(pktin, &inst, &inst_len);
7265 ssh_pkt_getstring(pktin, &lang, &lang_len);
7266 s->cur_prompt = new_prompts(ssh->frontend);
7267 s->cur_prompt->to_server = TRUE;
7269 /* FIXME: better prefix to distinguish from
7271 s->cur_prompt->name =
7272 dupprintf("SSH server: %.*s", name_len, name);
7273 s->cur_prompt->name_reqd = TRUE;
7275 s->cur_prompt->name =
7276 dupstr("SSH server authentication");
7277 s->cur_prompt->name_reqd = FALSE;
7279 /* FIXME: ugly to print "Using..." in prompt _every_
7280 * time round. Can this be done more subtly? */
7281 s->cur_prompt->instruction =
7282 dupprintf("Using keyboard-interactive authentication.%s%.*s",
7283 inst_len ? "\n" : "", inst_len, inst);
7284 s->cur_prompt->instr_reqd = TRUE;
7287 * Get the prompts from the packet.
7289 s->num_prompts = ssh_pkt_getuint32(pktin);
7290 for (i = 0; i < s->num_prompts; i++) {
7294 static char noprompt[] =
7295 "<server failed to send prompt>: ";
7297 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7298 echo = ssh2_pkt_getbool(pktin);
7301 prompt_len = lenof(noprompt)-1;
7303 add_prompt(s->cur_prompt,
7304 dupprintf("%.*s", prompt_len, prompt),
7305 echo, SSH_MAX_PASSWORD_LEN);
7309 * Get the user's responses.
7311 if (s->num_prompts) {
7312 int ret; /* not live over crReturn */
7313 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7316 crWaitUntilV(!pktin);
7317 ret = get_userpass_input(s->cur_prompt, in, inlen);
7322 * Failed to get responses. Terminate.
7324 free_prompts(s->cur_prompt);
7325 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7326 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7333 * Send the responses to the server.
7335 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7336 s->pktout->forcepad = 256;
7337 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7338 for (i=0; i < s->num_prompts; i++) {
7339 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7340 ssh2_pkt_addstring(s->pktout,
7341 s->cur_prompt->prompts[i]->result);
7342 end_log_omission(ssh, s->pktout);
7344 ssh2_pkt_send(ssh, s->pktout);
7347 * Get the next packet in case it's another
7350 crWaitUntilV(pktin);
7355 * We should have SUCCESS or FAILURE now.
7359 } else if (s->can_passwd) {
7362 * Plain old password authentication.
7364 int ret; /* not live over crReturn */
7365 int changereq_first_time; /* not live over crReturn */
7367 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7368 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7370 s->cur_prompt = new_prompts(ssh->frontend);
7371 s->cur_prompt->to_server = TRUE;
7372 s->cur_prompt->name = dupstr("SSH password");
7373 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
7376 FALSE, SSH_MAX_PASSWORD_LEN);
7378 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7381 crWaitUntilV(!pktin);
7382 ret = get_userpass_input(s->cur_prompt, in, inlen);
7387 * Failed to get responses. Terminate.
7389 free_prompts(s->cur_prompt);
7390 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7391 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7396 * Squirrel away the password. (We may need it later if
7397 * asked to change it.)
7399 s->password = dupstr(s->cur_prompt->prompts[0]->result);
7400 free_prompts(s->cur_prompt);
7403 * Send the password packet.
7405 * We pad out the password packet to 256 bytes to make
7406 * it harder for an attacker to find the length of the
7409 * Anyone using a password longer than 256 bytes
7410 * probably doesn't have much to worry about from
7411 * people who find out how long their password is!
7413 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7414 s->pktout->forcepad = 256;
7415 ssh2_pkt_addstring(s->pktout, s->username);
7416 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7417 /* service requested */
7418 ssh2_pkt_addstring(s->pktout, "password");
7419 ssh2_pkt_addbool(s->pktout, FALSE);
7420 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7421 ssh2_pkt_addstring(s->pktout, s->password);
7422 end_log_omission(ssh, s->pktout);
7423 ssh2_pkt_send(ssh, s->pktout);
7424 logevent("Sent password");
7425 s->type = AUTH_TYPE_PASSWORD;
7428 * Wait for next packet, in case it's a password change
7431 crWaitUntilV(pktin);
7432 changereq_first_time = TRUE;
7434 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
7437 * We're being asked for a new password
7438 * (perhaps not for the first time).
7439 * Loop until the server accepts it.
7442 int got_new = FALSE; /* not live over crReturn */
7443 char *prompt; /* not live over crReturn */
7444 int prompt_len; /* not live over crReturn */
7448 if (changereq_first_time)
7449 msg = "Server requested password change";
7451 msg = "Server rejected new password";
7453 c_write_str(ssh, msg);
7454 c_write_str(ssh, "\r\n");
7457 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7459 s->cur_prompt = new_prompts(ssh->frontend);
7460 s->cur_prompt->to_server = TRUE;
7461 s->cur_prompt->name = dupstr("New SSH password");
7462 s->cur_prompt->instruction =
7463 dupprintf("%.*s", prompt_len, prompt);
7464 s->cur_prompt->instr_reqd = TRUE;
7465 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
7466 FALSE, SSH_MAX_PASSWORD_LEN);
7467 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
7468 FALSE, SSH_MAX_PASSWORD_LEN);
7471 * Loop until the user manages to enter the same
7476 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7479 crWaitUntilV(!pktin);
7480 ret = get_userpass_input(s->cur_prompt, in, inlen);
7485 * Failed to get responses. Terminate.
7487 /* burn the evidence */
7488 free_prompts(s->cur_prompt);
7489 memset(s->password, 0, strlen(s->password));
7491 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7492 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7498 * Check the two passwords match.
7500 got_new = (strcmp(s->cur_prompt->prompts[0]->result,
7501 s->cur_prompt->prompts[1]->result)
7504 /* They don't. Silly user. */
7505 c_write_str(ssh, "Passwords do not match\r\n");
7510 * Send the new password (along with the old one).
7511 * (see above for padding rationale)
7513 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7514 s->pktout->forcepad = 256;
7515 ssh2_pkt_addstring(s->pktout, s->username);
7516 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7517 /* service requested */
7518 ssh2_pkt_addstring(s->pktout, "password");
7519 ssh2_pkt_addbool(s->pktout, TRUE);
7520 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7521 ssh2_pkt_addstring(s->pktout, s->password);
7522 ssh2_pkt_addstring(s->pktout,
7523 s->cur_prompt->prompts[0]->result);
7524 free_prompts(s->cur_prompt);
7525 end_log_omission(ssh, s->pktout);
7526 ssh2_pkt_send(ssh, s->pktout);
7527 logevent("Sent new password");
7530 * Now see what the server has to say about it.
7531 * (If it's CHANGEREQ again, it's not happy with the
7534 crWaitUntilV(pktin);
7535 changereq_first_time = FALSE;
7540 * We need to reexamine the current pktin at the top
7541 * of the loop. Either:
7542 * - we weren't asked to change password at all, in
7543 * which case it's a SUCCESS or FAILURE with the
7545 * - we sent a new password, and the server was
7546 * either OK with it (SUCCESS or FAILURE w/partial
7547 * success) or unhappy with the _old_ password
7548 * (FAILURE w/o partial success)
7549 * In any of these cases, we go back to the top of
7550 * the loop and start again.
7555 * We don't need the old password any more, in any
7556 * case. Burn the evidence.
7558 memset(s->password, 0, strlen(s->password));
7563 ssh_disconnect(ssh, NULL,
7564 "No supported authentication methods available",
7565 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7573 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7575 /* Clear up various bits and pieces from authentication. */
7576 if (s->publickey_blob) {
7577 sfree(s->publickey_blob);
7578 sfree(s->publickey_comment);
7580 if (s->agent_response)
7581 sfree(s->agent_response);
7584 * Now the connection protocol has started, one way or another.
7587 ssh->channels = newtree234(ssh_channelcmp);
7590 * Set up handlers for some connection protocol messages, so we
7591 * don't have to handle them repeatedly in this coroutine.
7593 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7594 ssh2_msg_channel_window_adjust;
7595 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7596 ssh2_msg_global_request;
7599 * Create the main session channel.
7601 if (!ssh->cfg.ssh_no_shell) {
7602 ssh->mainchan = snew(struct ssh_channel);
7603 ssh->mainchan->ssh = ssh;
7604 ssh->mainchan->localid = alloc_channel_id(ssh);
7605 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7606 ssh2_pkt_addstring(s->pktout, "session");
7607 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7608 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7609 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7610 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7611 ssh2_pkt_send(ssh, s->pktout);
7612 crWaitUntilV(pktin);
7613 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7614 bombout(("Server refused to open a session"));
7616 /* FIXME: error data comes back in FAILURE packet */
7618 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7619 bombout(("Server's channel confirmation cited wrong channel"));
7622 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7623 ssh->mainchan->halfopen = FALSE;
7624 ssh->mainchan->type = CHAN_MAINSESSION;
7625 ssh->mainchan->closes = 0;
7626 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7627 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7628 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7629 add234(ssh->channels, ssh->mainchan);
7630 update_specials_menu(ssh->frontend);
7631 logevent("Opened channel for session");
7633 ssh->mainchan = NULL;
7636 * Now we have a channel, make dispatch table entries for
7637 * general channel-based messages.
7639 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7640 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7641 ssh2_msg_channel_data;
7642 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7643 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7644 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7645 ssh2_msg_channel_open_confirmation;
7646 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7647 ssh2_msg_channel_open_failure;
7648 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7649 ssh2_msg_channel_request;
7650 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7651 ssh2_msg_channel_open;
7654 * Potentially enable X11 forwarding.
7656 if (ssh->mainchan && ssh->cfg.x11_forward) {
7657 char proto[20], data[64];
7658 logevent("Requesting X11 forwarding");
7659 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7660 data, sizeof(data), ssh->cfg.x11_auth);
7661 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7662 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7663 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7664 ssh2_pkt_addstring(s->pktout, "x11-req");
7665 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7666 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7667 ssh2_pkt_addstring(s->pktout, proto);
7669 * Note that while we blank the X authentication data here, we don't
7670 * take any special action to blank the start of an X11 channel,
7671 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7672 * without having session blanking enabled is likely to leak your
7673 * cookie into the log.
7675 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7676 ssh2_pkt_addstring(s->pktout, data);
7677 end_log_omission(ssh, s->pktout);
7678 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7679 ssh2_pkt_send(ssh, s->pktout);
7681 crWaitUntilV(pktin);
7683 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7684 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7685 bombout(("Unexpected response to X11 forwarding request:"
7686 " packet type %d", pktin->type));
7689 logevent("X11 forwarding refused");
7691 logevent("X11 forwarding enabled");
7692 ssh->X11_fwd_enabled = TRUE;
7697 * Enable port forwardings.
7699 ssh_setup_portfwd(ssh, &ssh->cfg);
7702 * Potentially enable agent forwarding.
7704 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7705 logevent("Requesting OpenSSH-style agent forwarding");
7706 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7707 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7708 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7709 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7710 ssh2_pkt_send(ssh, s->pktout);
7712 crWaitUntilV(pktin);
7714 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7715 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7716 bombout(("Unexpected response to agent forwarding request:"
7717 " packet type %d", pktin->type));
7720 logevent("Agent forwarding refused");
7722 logevent("Agent forwarding enabled");
7723 ssh->agentfwd_enabled = TRUE;
7728 * Now allocate a pty for the session.
7730 if (ssh->mainchan && !ssh->cfg.nopty) {
7731 /* Unpick the terminal-speed string. */
7732 /* XXX perhaps we should allow no speeds to be sent. */
7733 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7734 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7735 /* Build the pty request. */
7736 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7737 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7738 ssh2_pkt_addstring(s->pktout, "pty-req");
7739 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7740 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7741 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7742 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7743 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7744 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7745 ssh2_pkt_addstring_start(s->pktout);
7746 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7747 ssh2_send_ttymode, (void *)s->pktout);
7748 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
7749 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7750 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
7751 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7752 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7753 ssh2_pkt_send(ssh, s->pktout);
7754 ssh->state = SSH_STATE_INTERMED;
7756 crWaitUntilV(pktin);
7758 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7759 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7760 bombout(("Unexpected response to pty request:"
7761 " packet type %d", pktin->type));
7764 c_write_str(ssh, "Server refused to allocate pty\r\n");
7765 ssh->editing = ssh->echoing = 1;
7767 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7768 ssh->ospeed, ssh->ispeed);
7771 ssh->editing = ssh->echoing = 1;
7775 * Send environment variables.
7777 * Simplest thing here is to send all the requests at once, and
7778 * then wait for a whole bunch of successes or failures.
7780 if (ssh->mainchan && *ssh->cfg.environmt) {
7781 char *e = ssh->cfg.environmt;
7782 char *var, *varend, *val;
7788 while (*e && *e != '\t') e++;
7790 if (*e == '\t') e++;
7795 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7796 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7797 ssh2_pkt_addstring(s->pktout, "env");
7798 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7799 ssh2_pkt_addstring_start(s->pktout);
7800 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7801 ssh2_pkt_addstring(s->pktout, val);
7802 ssh2_pkt_send(ssh, s->pktout);
7807 logeventf(ssh, "Sent %d environment variables", s->num_env);
7810 s->env_left = s->num_env;
7812 while (s->env_left > 0) {
7813 crWaitUntilV(pktin);
7815 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7816 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7817 bombout(("Unexpected response to environment request:"
7818 " packet type %d", pktin->type));
7828 if (s->env_ok == s->num_env) {
7829 logevent("All environment variables successfully set");
7830 } else if (s->env_ok == 0) {
7831 logevent("All environment variables refused");
7832 c_write_str(ssh, "Server refused to set environment variables\r\n");
7834 logeventf(ssh, "%d environment variables refused",
7835 s->num_env - s->env_ok);
7836 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7841 * Start a shell or a remote command. We may have to attempt
7842 * this twice if the config data has provided a second choice
7845 if (ssh->mainchan) while (1) {
7849 if (ssh->fallback_cmd) {
7850 subsys = ssh->cfg.ssh_subsys2;
7851 cmd = ssh->cfg.remote_cmd_ptr2;
7853 subsys = ssh->cfg.ssh_subsys;
7854 cmd = ssh->cfg.remote_cmd_ptr;
7855 if (!cmd) cmd = ssh->cfg.remote_cmd;
7858 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7859 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7861 ssh2_pkt_addstring(s->pktout, "subsystem");
7862 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7863 ssh2_pkt_addstring(s->pktout, cmd);
7865 ssh2_pkt_addstring(s->pktout, "exec");
7866 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7867 ssh2_pkt_addstring(s->pktout, cmd);
7869 ssh2_pkt_addstring(s->pktout, "shell");
7870 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7872 ssh2_pkt_send(ssh, s->pktout);
7874 crWaitUntilV(pktin);
7876 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7877 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7878 bombout(("Unexpected response to shell/command request:"
7879 " packet type %d", pktin->type));
7883 * We failed to start the command. If this is the
7884 * fallback command, we really are finished; if it's
7885 * not, and if the fallback command exists, try falling
7886 * back to it before complaining.
7888 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7889 logevent("Primary command failed; attempting fallback");
7890 ssh->fallback_cmd = TRUE;
7893 bombout(("Server refused to start a shell/command"));
7896 logevent("Started a shell/command");
7901 ssh->state = SSH_STATE_SESSION;
7902 if (ssh->size_needed)
7903 ssh_size(ssh, ssh->term_width, ssh->term_height);
7904 if (ssh->eof_needed)
7905 ssh_special(ssh, TS_EOF);
7911 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7916 s->try_send = FALSE;
7920 * _All_ the connection-layer packets we expect to
7921 * receive are now handled by the dispatch table.
7922 * Anything that reaches here must be bogus.
7925 bombout(("Strange packet received: type %d", pktin->type));
7927 } else if (ssh->mainchan) {
7929 * We have spare data. Add it to the channel buffer.
7931 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7936 struct ssh_channel *c;
7938 * Try to send data on all channels if we can.
7940 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7941 ssh2_try_send_and_unthrottle(c);
7949 * Handlers for SSH-2 messages that might arrive at any moment.
7951 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7953 /* log reason code in disconnect message */
7955 int nowlen, reason, msglen;
7957 reason = ssh_pkt_getuint32(pktin);
7958 ssh_pkt_getstring(pktin, &msg, &msglen);
7960 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7961 buf = dupprintf("Received disconnect message (%s)",
7962 ssh2_disconnect_reasons[reason]);
7964 buf = dupprintf("Received disconnect message (unknown"
7965 " type %d)", reason);
7969 buf = dupprintf("Disconnection message text: %n%.*s",
7970 &nowlen, msglen, msg);
7972 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7974 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7975 ssh2_disconnect_reasons[reason] : "unknown",
7980 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7982 /* log the debug message */
7987 /* XXX maybe we should actually take notice of this */
7988 always_display = ssh2_pkt_getbool(pktin);
7989 ssh_pkt_getstring(pktin, &msg, &msglen);
7991 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7994 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7996 struct Packet *pktout;
7997 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7998 ssh2_pkt_adduint32(pktout, pktin->sequence);
8000 * UNIMPLEMENTED messages MUST appear in the same order as the
8001 * messages they respond to. Hence, never queue them.
8003 ssh2_pkt_send_noqueue(ssh, pktout);
8007 * Handle the top-level SSH-2 protocol.
8009 static void ssh2_protocol_setup(Ssh ssh)
8014 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
8016 for (i = 0; i < 256; i++)
8017 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
8020 * Any message we actually understand, we set to NULL so that
8021 * the coroutines will get it.
8023 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
8024 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
8025 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
8026 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
8027 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
8028 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
8029 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
8030 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
8031 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
8032 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
8033 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
8034 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
8035 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
8036 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
8037 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8038 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
8039 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
8040 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
8041 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
8042 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
8043 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
8044 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
8045 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
8046 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
8047 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
8048 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
8049 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
8050 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
8051 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
8052 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
8053 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
8054 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
8055 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
8058 * These special message types we install handlers for.
8060 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
8061 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
8062 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
8065 static void ssh2_timer(void *ctx, long now)
8069 if (ssh->state == SSH_STATE_CLOSED)
8072 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
8073 now - ssh->next_rekey >= 0) {
8074 do_ssh2_transport(ssh, "timeout", -1, NULL);
8078 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
8079 struct Packet *pktin)
8081 unsigned char *in = (unsigned char *)vin;
8082 if (ssh->state == SSH_STATE_CLOSED)
8086 ssh->incoming_data_size += pktin->encrypted_len;
8087 if (!ssh->kex_in_progress &&
8088 ssh->max_data_size != 0 &&
8089 ssh->incoming_data_size > ssh->max_data_size)
8090 do_ssh2_transport(ssh, "too much data received", -1, NULL);
8093 if (pktin && ssh->packet_dispatch[pktin->type]) {
8094 ssh->packet_dispatch[pktin->type](ssh, pktin);
8098 if (!ssh->protocol_initial_phase_done ||
8099 (pktin && pktin->type >= 20 && pktin->type < 50)) {
8100 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
8101 !ssh->protocol_initial_phase_done) {
8102 ssh->protocol_initial_phase_done = TRUE;
8104 * Allow authconn to initialise itself.
8106 do_ssh2_authconn(ssh, NULL, 0, NULL);
8109 do_ssh2_authconn(ssh, in, inlen, pktin);
8114 * Called to set up the connection.
8116 * Returns an error message, or NULL on success.
8118 static const char *ssh_init(void *frontend_handle, void **backend_handle,
8120 char *host, int port, char **realhost, int nodelay,
8126 ssh = snew(struct ssh_tag);
8127 ssh->cfg = *cfg; /* STRUCTURE COPY */
8128 ssh->version = 0; /* when not ready yet */
8131 ssh->v1_cipher_ctx = NULL;
8132 ssh->crcda_ctx = NULL;
8133 ssh->cscipher = NULL;
8134 ssh->cs_cipher_ctx = NULL;
8135 ssh->sccipher = NULL;
8136 ssh->sc_cipher_ctx = NULL;
8138 ssh->cs_mac_ctx = NULL;
8140 ssh->sc_mac_ctx = NULL;
8142 ssh->cs_comp_ctx = NULL;
8144 ssh->sc_comp_ctx = NULL;
8146 ssh->kex_ctx = NULL;
8147 ssh->hostkey = NULL;
8149 ssh->close_expected = FALSE;
8150 ssh->clean_exit = FALSE;
8151 ssh->state = SSH_STATE_PREPACKET;
8152 ssh->size_needed = FALSE;
8153 ssh->eof_needed = FALSE;
8156 ssh->deferred_send_data = NULL;
8157 ssh->deferred_len = 0;
8158 ssh->deferred_size = 0;
8159 ssh->fallback_cmd = 0;
8161 ssh->x11auth = NULL;
8162 ssh->v1_compressing = FALSE;
8163 ssh->v2_outgoing_sequence = 0;
8164 ssh->ssh1_rdpkt_crstate = 0;
8165 ssh->ssh2_rdpkt_crstate = 0;
8166 ssh->do_ssh_init_crstate = 0;
8167 ssh->ssh_gotdata_crstate = 0;
8168 ssh->do_ssh1_connection_crstate = 0;
8169 ssh->do_ssh1_login_crstate = 0;
8170 ssh->do_ssh2_transport_crstate = 0;
8171 ssh->do_ssh2_authconn_crstate = 0;
8172 ssh->do_ssh_init_state = NULL;
8173 ssh->do_ssh1_login_state = NULL;
8174 ssh->do_ssh2_transport_state = NULL;
8175 ssh->do_ssh2_authconn_state = NULL;
8178 ssh->mainchan = NULL;
8179 ssh->throttled_all = 0;
8180 ssh->v1_stdout_throttling = 0;
8182 ssh->queuelen = ssh->queuesize = 0;
8183 ssh->queueing = FALSE;
8184 ssh->qhead = ssh->qtail = NULL;
8185 ssh->deferred_rekey_reason = NULL;
8186 bufchain_init(&ssh->queued_incoming_data);
8187 ssh->frozen = FALSE;
8189 *backend_handle = ssh;
8192 if (crypto_startup() == 0)
8193 return "Microsoft high encryption pack not installed!";
8196 ssh->frontend = frontend_handle;
8197 ssh->term_width = ssh->cfg.width;
8198 ssh->term_height = ssh->cfg.height;
8200 ssh->channels = NULL;
8201 ssh->rportfwds = NULL;
8202 ssh->portfwds = NULL;
8207 ssh->v1_throttle_count = 0;
8208 ssh->overall_bufsize = 0;
8209 ssh->fallback_cmd = 0;
8211 ssh->protocol = NULL;
8213 ssh->protocol_initial_phase_done = FALSE;
8217 ssh->incoming_data_size = ssh->outgoing_data_size =
8218 ssh->deferred_data_size = 0L;
8219 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
8220 ssh->kex_in_progress = FALSE;
8222 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
8231 static void ssh_free(void *handle)
8233 Ssh ssh = (Ssh) handle;
8234 struct ssh_channel *c;
8235 struct ssh_rportfwd *pf;
8237 if (ssh->v1_cipher_ctx)
8238 ssh->cipher->free_context(ssh->v1_cipher_ctx);
8239 if (ssh->cs_cipher_ctx)
8240 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
8241 if (ssh->sc_cipher_ctx)
8242 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
8243 if (ssh->cs_mac_ctx)
8244 ssh->csmac->free_context(ssh->cs_mac_ctx);
8245 if (ssh->sc_mac_ctx)
8246 ssh->scmac->free_context(ssh->sc_mac_ctx);
8247 if (ssh->cs_comp_ctx) {
8249 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
8251 zlib_compress_cleanup(ssh->cs_comp_ctx);
8253 if (ssh->sc_comp_ctx) {
8255 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
8257 zlib_decompress_cleanup(ssh->sc_comp_ctx);
8260 dh_cleanup(ssh->kex_ctx);
8261 sfree(ssh->savedhost);
8263 while (ssh->queuelen-- > 0)
8264 ssh_free_packet(ssh->queue[ssh->queuelen]);
8267 while (ssh->qhead) {
8268 struct queued_handler *qh = ssh->qhead;
8269 ssh->qhead = qh->next;
8272 ssh->qhead = ssh->qtail = NULL;
8274 if (ssh->channels) {
8275 while ((c = delpos234(ssh->channels, 0)) != NULL) {
8278 if (c->u.x11.s != NULL)
8279 x11_close(c->u.x11.s);
8282 if (c->u.pfd.s != NULL)
8283 pfd_close(c->u.pfd.s);
8288 freetree234(ssh->channels);
8289 ssh->channels = NULL;
8292 if (ssh->rportfwds) {
8293 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8295 freetree234(ssh->rportfwds);
8296 ssh->rportfwds = NULL;
8298 sfree(ssh->deferred_send_data);
8300 x11_free_auth(ssh->x11auth);
8301 sfree(ssh->do_ssh_init_state);
8302 sfree(ssh->do_ssh1_login_state);
8303 sfree(ssh->do_ssh2_transport_state);
8304 sfree(ssh->do_ssh2_authconn_state);
8307 if (ssh->crcda_ctx) {
8308 crcda_free_context(ssh->crcda_ctx);
8309 ssh->crcda_ctx = NULL;
8312 ssh_do_close(ssh, TRUE);
8313 expire_timer_context(ssh);
8315 pinger_free(ssh->pinger);
8316 bufchain_clear(&ssh->queued_incoming_data);
8323 * Reconfigure the SSH backend.
8325 static void ssh_reconfig(void *handle, Config *cfg)
8327 Ssh ssh = (Ssh) handle;
8328 char *rekeying = NULL, rekey_mandatory = FALSE;
8329 unsigned long old_max_data_size;
8331 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8333 ssh_setup_portfwd(ssh, cfg);
8335 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8336 cfg->ssh_rekey_time != 0) {
8337 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8338 long now = GETTICKCOUNT();
8340 if (new_next - now < 0) {
8341 rekeying = "timeout shortened";
8343 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8347 old_max_data_size = ssh->max_data_size;
8348 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8349 if (old_max_data_size != ssh->max_data_size &&
8350 ssh->max_data_size != 0) {
8351 if (ssh->outgoing_data_size > ssh->max_data_size ||
8352 ssh->incoming_data_size > ssh->max_data_size)
8353 rekeying = "data limit lowered";
8356 if (ssh->cfg.compression != cfg->compression) {
8357 rekeying = "compression setting changed";
8358 rekey_mandatory = TRUE;
8361 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8362 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8363 sizeof(ssh->cfg.ssh_cipherlist))) {
8364 rekeying = "cipher settings changed";
8365 rekey_mandatory = TRUE;
8368 ssh->cfg = *cfg; /* STRUCTURE COPY */
8371 if (!ssh->kex_in_progress) {
8372 do_ssh2_transport(ssh, rekeying, -1, NULL);
8373 } else if (rekey_mandatory) {
8374 ssh->deferred_rekey_reason = rekeying;
8380 * Called to send data down the SSH connection.
8382 static int ssh_send(void *handle, char *buf, int len)
8384 Ssh ssh = (Ssh) handle;
8386 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8389 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8391 return ssh_sendbuffer(ssh);
8395 * Called to query the current amount of buffered stdin data.
8397 static int ssh_sendbuffer(void *handle)
8399 Ssh ssh = (Ssh) handle;
8402 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8406 * If the SSH socket itself has backed up, add the total backup
8407 * size on that to any individual buffer on the stdin channel.
8410 if (ssh->throttled_all)
8411 override_value = ssh->overall_bufsize;
8413 if (ssh->version == 1) {
8414 return override_value;
8415 } else if (ssh->version == 2) {
8416 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8417 return override_value;
8419 return (override_value +
8420 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8427 * Called to set the size of the window from SSH's POV.
8429 static void ssh_size(void *handle, int width, int height)
8431 Ssh ssh = (Ssh) handle;
8432 struct Packet *pktout;
8434 ssh->term_width = width;
8435 ssh->term_height = height;
8437 switch (ssh->state) {
8438 case SSH_STATE_BEFORE_SIZE:
8439 case SSH_STATE_PREPACKET:
8440 case SSH_STATE_CLOSED:
8441 break; /* do nothing */
8442 case SSH_STATE_INTERMED:
8443 ssh->size_needed = TRUE; /* buffer for later */
8445 case SSH_STATE_SESSION:
8446 if (!ssh->cfg.nopty) {
8447 if (ssh->version == 1) {
8448 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8449 PKT_INT, ssh->term_height,
8450 PKT_INT, ssh->term_width,
8451 PKT_INT, 0, PKT_INT, 0, PKT_END);
8452 } else if (ssh->mainchan) {
8453 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8454 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8455 ssh2_pkt_addstring(pktout, "window-change");
8456 ssh2_pkt_addbool(pktout, 0);
8457 ssh2_pkt_adduint32(pktout, ssh->term_width);
8458 ssh2_pkt_adduint32(pktout, ssh->term_height);
8459 ssh2_pkt_adduint32(pktout, 0);
8460 ssh2_pkt_adduint32(pktout, 0);
8461 ssh2_pkt_send(ssh, pktout);
8469 * Return a list of the special codes that make sense in this
8472 static const struct telnet_special *ssh_get_specials(void *handle)
8474 static const struct telnet_special ssh1_ignore_special[] = {
8475 {"IGNORE message", TS_NOP}
8477 static const struct telnet_special ssh2_transport_specials[] = {
8478 {"IGNORE message", TS_NOP},
8479 {"Repeat key exchange", TS_REKEY},
8481 static const struct telnet_special ssh2_session_specials[] = {
8484 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8485 * They include all the ISO C signals, but are a subset of the POSIX
8486 * required signals. */
8487 {"SIGINT (Interrupt)", TS_SIGINT},
8488 {"SIGTERM (Terminate)", TS_SIGTERM},
8489 {"SIGKILL (Kill)", TS_SIGKILL},
8490 {"SIGQUIT (Quit)", TS_SIGQUIT},
8491 {"SIGHUP (Hangup)", TS_SIGHUP},
8492 {"More signals", TS_SUBMENU},
8493 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8494 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8495 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8496 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8499 static const struct telnet_special specials_end[] = {
8502 /* XXX review this length for any changes: */
8503 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8504 lenof(ssh2_session_specials) +
8505 lenof(specials_end)];
8506 Ssh ssh = (Ssh) handle;
8508 #define ADD_SPECIALS(name) \
8510 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8511 memcpy(&ssh_specials[i], name, sizeof name); \
8515 if (ssh->version == 1) {
8516 /* Don't bother offering IGNORE if we've decided the remote
8517 * won't cope with it, since we wouldn't bother sending it if
8519 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8520 ADD_SPECIALS(ssh1_ignore_special);
8521 } else if (ssh->version == 2) {
8522 ADD_SPECIALS(ssh2_transport_specials);
8524 ADD_SPECIALS(ssh2_session_specials);
8525 } /* else we're not ready yet */
8528 ADD_SPECIALS(specials_end);
8529 return ssh_specials;
8537 * Send special codes. TS_EOF is useful for `plink', so you
8538 * can send an EOF and collect resulting output (e.g. `plink
8541 static void ssh_special(void *handle, Telnet_Special code)
8543 Ssh ssh = (Ssh) handle;
8544 struct Packet *pktout;
8546 if (code == TS_EOF) {
8547 if (ssh->state != SSH_STATE_SESSION) {
8549 * Buffer the EOF in case we are pre-SESSION, so we can
8550 * send it as soon as we reach SESSION.
8553 ssh->eof_needed = TRUE;
8556 if (ssh->version == 1) {
8557 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8558 } else if (ssh->mainchan) {
8559 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8560 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8561 ssh2_pkt_send(ssh, pktout);
8562 ssh->send_ok = 0; /* now stop trying to read from stdin */
8564 logevent("Sent EOF message");
8565 } else if (code == TS_PING || code == TS_NOP) {
8566 if (ssh->state == SSH_STATE_CLOSED
8567 || ssh->state == SSH_STATE_PREPACKET) return;
8568 if (ssh->version == 1) {
8569 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8570 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8572 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8573 ssh2_pkt_addstring_start(pktout);
8574 ssh2_pkt_send_noqueue(ssh, pktout);
8576 } else if (code == TS_REKEY) {
8577 if (!ssh->kex_in_progress && ssh->version == 2) {
8578 do_ssh2_transport(ssh, "at user request", -1, NULL);
8580 } else if (code == TS_BRK) {
8581 if (ssh->state == SSH_STATE_CLOSED
8582 || ssh->state == SSH_STATE_PREPACKET) return;
8583 if (ssh->version == 1) {
8584 logevent("Unable to send BREAK signal in SSH-1");
8585 } else if (ssh->mainchan) {
8586 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8587 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8588 ssh2_pkt_addstring(pktout, "break");
8589 ssh2_pkt_addbool(pktout, 0);
8590 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8591 ssh2_pkt_send(ssh, pktout);
8594 /* Is is a POSIX signal? */
8595 char *signame = NULL;
8596 if (code == TS_SIGABRT) signame = "ABRT";
8597 if (code == TS_SIGALRM) signame = "ALRM";
8598 if (code == TS_SIGFPE) signame = "FPE";
8599 if (code == TS_SIGHUP) signame = "HUP";
8600 if (code == TS_SIGILL) signame = "ILL";
8601 if (code == TS_SIGINT) signame = "INT";
8602 if (code == TS_SIGKILL) signame = "KILL";
8603 if (code == TS_SIGPIPE) signame = "PIPE";
8604 if (code == TS_SIGQUIT) signame = "QUIT";
8605 if (code == TS_SIGSEGV) signame = "SEGV";
8606 if (code == TS_SIGTERM) signame = "TERM";
8607 if (code == TS_SIGUSR1) signame = "USR1";
8608 if (code == TS_SIGUSR2) signame = "USR2";
8609 /* The SSH-2 protocol does in principle support arbitrary named
8610 * signals, including signame@domain, but we don't support those. */
8612 /* It's a signal. */
8613 if (ssh->version == 2 && ssh->mainchan) {
8614 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8615 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8616 ssh2_pkt_addstring(pktout, "signal");
8617 ssh2_pkt_addbool(pktout, 0);
8618 ssh2_pkt_addstring(pktout, signame);
8619 ssh2_pkt_send(ssh, pktout);
8620 logeventf(ssh, "Sent signal SIG%s", signame);
8623 /* Never heard of it. Do nothing */
8628 void *new_sock_channel(void *handle, Socket s)
8630 Ssh ssh = (Ssh) handle;
8631 struct ssh_channel *c;
8632 c = snew(struct ssh_channel);
8637 c->localid = alloc_channel_id(ssh);
8639 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8641 bufchain_init(&c->v.v2.outbuffer);
8642 add234(ssh->channels, c);
8648 * This is called when stdout/stderr (the entity to which
8649 * from_backend sends data) manages to clear some backlog.
8651 static void ssh_unthrottle(void *handle, int bufsize)
8653 Ssh ssh = (Ssh) handle;
8654 if (ssh->version == 1) {
8655 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8656 ssh->v1_stdout_throttling = 0;
8657 ssh1_throttle(ssh, -1);
8660 if (ssh->mainchan && ssh->mainchan->closes == 0)
8661 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8665 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8667 struct ssh_channel *c = (struct ssh_channel *)channel;
8669 struct Packet *pktout;
8671 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8673 if (ssh->version == 1) {
8674 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8675 PKT_INT, c->localid,
8678 /* PKT_STR, <org:orgport>, */
8681 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8682 ssh2_pkt_addstring(pktout, "direct-tcpip");
8683 ssh2_pkt_adduint32(pktout, c->localid);
8684 c->v.v2.locwindow = OUR_V2_WINSIZE;
8685 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8686 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8687 ssh2_pkt_addstring(pktout, hostname);
8688 ssh2_pkt_adduint32(pktout, port);
8690 * We make up values for the originator data; partly it's
8691 * too much hassle to keep track, and partly I'm not
8692 * convinced the server should be told details like that
8693 * about my local network configuration.
8694 * The "originator IP address" is syntactically a numeric
8695 * IP address, and some servers (e.g., Tectia) get upset
8696 * if it doesn't match this syntax.
8698 ssh2_pkt_addstring(pktout, "0.0.0.0");
8699 ssh2_pkt_adduint32(pktout, 0);
8700 ssh2_pkt_send(ssh, pktout);
8704 static Socket ssh_socket(void *handle)
8706 Ssh ssh = (Ssh) handle;
8710 static int ssh_sendok(void *handle)
8712 Ssh ssh = (Ssh) handle;
8713 return ssh->send_ok;
8716 static int ssh_ldisc(void *handle, int option)
8718 Ssh ssh = (Ssh) handle;
8719 if (option == LD_ECHO)
8720 return ssh->echoing;
8721 if (option == LD_EDIT)
8722 return ssh->editing;
8726 static void ssh_provide_ldisc(void *handle, void *ldisc)
8728 Ssh ssh = (Ssh) handle;
8732 static void ssh_provide_logctx(void *handle, void *logctx)
8734 Ssh ssh = (Ssh) handle;
8735 ssh->logctx = logctx;
8738 static int ssh_return_exitcode(void *handle)
8740 Ssh ssh = (Ssh) handle;
8744 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8748 * cfg_info for SSH is the currently running version of the
8749 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8751 static int ssh_cfg_info(void *handle)
8753 Ssh ssh = (Ssh) handle;
8754 return ssh->version;
8758 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8759 * that fails. This variable is the means by which scp.c can reach
8760 * into the SSH code and find out which one it got.
8762 extern int ssh_fallback_cmd(void *handle)
8764 Ssh ssh = (Ssh) handle;
8765 return ssh->fallback_cmd;
8768 Backend ssh_backend = {
8778 ssh_return_exitcode,