27 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
28 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
29 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
30 #define SSH1_CMSG_USER 4 /* 0x4 */
31 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
32 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
33 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
34 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
35 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
36 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
37 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
38 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
39 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
40 #define SSH1_SMSG_FAILURE 15 /* 0xf */
41 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
42 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
43 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
44 #define SSH1_CMSG_EOF 19 /* 0x13 */
45 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
46 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
47 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
48 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
49 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
50 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
51 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
52 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
53 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
54 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
55 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
56 #define SSH1_MSG_IGNORE 32 /* 0x20 */
57 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
58 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
59 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
60 #define SSH1_MSG_DEBUG 36 /* 0x24 */
61 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
62 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
63 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
64 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
65 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
66 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
67 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
69 #define SSH1_AUTH_RHOSTS 1 /* 0x1 */
70 #define SSH1_AUTH_RSA 2 /* 0x2 */
71 #define SSH1_AUTH_PASSWORD 3 /* 0x3 */
72 #define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */
73 #define SSH1_AUTH_TIS 5 /* 0x5 */
74 #define SSH1_AUTH_CCARD 16 /* 0x10 */
76 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
77 /* Mask for protoflags we will echo back to server if seen */
78 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
80 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
81 #define SSH2_MSG_IGNORE 2 /* 0x2 */
82 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
83 #define SSH2_MSG_DEBUG 4 /* 0x4 */
84 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
85 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
86 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
87 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
88 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
89 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
90 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
91 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
92 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
93 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
94 #define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
95 #define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
96 #define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
97 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
98 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
99 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
100 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
101 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
102 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
103 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
104 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
105 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
106 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
107 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
108 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
109 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
110 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
111 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
112 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
113 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
114 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
115 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
116 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
117 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
118 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
119 #define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60
120 #define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61
121 #define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63
122 #define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64
123 #define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65
124 #define SSH2_MSG_USERAUTH_GSSAPI_MIC 66
127 * Packet type contexts, so that ssh2_pkt_type can correctly decode
128 * the ambiguous type numbers back into the correct type strings.
138 SSH2_PKTCTX_PUBLICKEY,
139 SSH2_PKTCTX_PASSWORD,
144 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
145 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
146 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
147 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
148 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
149 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
150 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
151 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
152 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
153 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
154 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
155 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
156 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
157 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
158 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
160 static const char *const ssh2_disconnect_reasons[] = {
162 "host not allowed to connect",
164 "key exchange failed",
165 "host authentication failed",
168 "service not available",
169 "protocol version not supported",
170 "host key not verifiable",
173 "too many connections",
174 "auth cancelled by user",
175 "no more auth methods available",
179 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
180 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
181 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
182 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
184 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
187 * Various remote-bug flags.
189 #define BUG_CHOKES_ON_SSH1_IGNORE 1
190 #define BUG_SSH2_HMAC 2
191 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
192 #define BUG_CHOKES_ON_RSA 8
193 #define BUG_SSH2_RSA_PADDING 16
194 #define BUG_SSH2_DERIVEKEY 32
195 #define BUG_SSH2_REKEY 64
196 #define BUG_SSH2_PK_SESSIONID 128
197 #define BUG_SSH2_MAXPKT 256
198 #define BUG_CHOKES_ON_SSH2_IGNORE 512
201 * Codes for terminal modes.
202 * Most of these are the same in SSH-1 and SSH-2.
203 * This list is derived from RFC 4254 and
206 static const struct {
207 const char* const mode;
209 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
211 /* "V" prefix discarded for special characters relative to SSH specs */
212 { "INTR", 1, TTY_OP_CHAR },
213 { "QUIT", 2, TTY_OP_CHAR },
214 { "ERASE", 3, TTY_OP_CHAR },
215 { "KILL", 4, TTY_OP_CHAR },
216 { "EOF", 5, TTY_OP_CHAR },
217 { "EOL", 6, TTY_OP_CHAR },
218 { "EOL2", 7, TTY_OP_CHAR },
219 { "START", 8, TTY_OP_CHAR },
220 { "STOP", 9, TTY_OP_CHAR },
221 { "SUSP", 10, TTY_OP_CHAR },
222 { "DSUSP", 11, TTY_OP_CHAR },
223 { "REPRINT", 12, TTY_OP_CHAR },
224 { "WERASE", 13, TTY_OP_CHAR },
225 { "LNEXT", 14, TTY_OP_CHAR },
226 { "FLUSH", 15, TTY_OP_CHAR },
227 { "SWTCH", 16, TTY_OP_CHAR },
228 { "STATUS", 17, TTY_OP_CHAR },
229 { "DISCARD", 18, TTY_OP_CHAR },
230 { "IGNPAR", 30, TTY_OP_BOOL },
231 { "PARMRK", 31, TTY_OP_BOOL },
232 { "INPCK", 32, TTY_OP_BOOL },
233 { "ISTRIP", 33, TTY_OP_BOOL },
234 { "INLCR", 34, TTY_OP_BOOL },
235 { "IGNCR", 35, TTY_OP_BOOL },
236 { "ICRNL", 36, TTY_OP_BOOL },
237 { "IUCLC", 37, TTY_OP_BOOL },
238 { "IXON", 38, TTY_OP_BOOL },
239 { "IXANY", 39, TTY_OP_BOOL },
240 { "IXOFF", 40, TTY_OP_BOOL },
241 { "IMAXBEL", 41, TTY_OP_BOOL },
242 { "ISIG", 50, TTY_OP_BOOL },
243 { "ICANON", 51, TTY_OP_BOOL },
244 { "XCASE", 52, TTY_OP_BOOL },
245 { "ECHO", 53, TTY_OP_BOOL },
246 { "ECHOE", 54, TTY_OP_BOOL },
247 { "ECHOK", 55, TTY_OP_BOOL },
248 { "ECHONL", 56, TTY_OP_BOOL },
249 { "NOFLSH", 57, TTY_OP_BOOL },
250 { "TOSTOP", 58, TTY_OP_BOOL },
251 { "IEXTEN", 59, TTY_OP_BOOL },
252 { "ECHOCTL", 60, TTY_OP_BOOL },
253 { "ECHOKE", 61, TTY_OP_BOOL },
254 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
255 { "OPOST", 70, TTY_OP_BOOL },
256 { "OLCUC", 71, TTY_OP_BOOL },
257 { "ONLCR", 72, TTY_OP_BOOL },
258 { "OCRNL", 73, TTY_OP_BOOL },
259 { "ONOCR", 74, TTY_OP_BOOL },
260 { "ONLRET", 75, TTY_OP_BOOL },
261 { "CS7", 90, TTY_OP_BOOL },
262 { "CS8", 91, TTY_OP_BOOL },
263 { "PARENB", 92, TTY_OP_BOOL },
264 { "PARODD", 93, TTY_OP_BOOL }
267 /* Miscellaneous other tty-related constants. */
268 #define SSH_TTY_OP_END 0
269 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
270 #define SSH1_TTY_OP_ISPEED 192
271 #define SSH1_TTY_OP_OSPEED 193
272 #define SSH2_TTY_OP_ISPEED 128
273 #define SSH2_TTY_OP_OSPEED 129
275 /* Helper functions for parsing tty-related config. */
276 static unsigned int ssh_tty_parse_specchar(char *s)
281 ret = ctrlparse(s, &next);
282 if (!next) ret = s[0];
284 ret = 255; /* special value meaning "don't set" */
288 static unsigned int ssh_tty_parse_boolean(char *s)
290 if (stricmp(s, "yes") == 0 ||
291 stricmp(s, "on") == 0 ||
292 stricmp(s, "true") == 0 ||
293 stricmp(s, "+") == 0)
295 else if (stricmp(s, "no") == 0 ||
296 stricmp(s, "off") == 0 ||
297 stricmp(s, "false") == 0 ||
298 stricmp(s, "-") == 0)
299 return 0; /* false */
301 return (atoi(s) != 0);
304 #define translate(x) if (type == x) return #x
305 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
306 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
307 static char *ssh1_pkt_type(int type)
309 translate(SSH1_MSG_DISCONNECT);
310 translate(SSH1_SMSG_PUBLIC_KEY);
311 translate(SSH1_CMSG_SESSION_KEY);
312 translate(SSH1_CMSG_USER);
313 translate(SSH1_CMSG_AUTH_RSA);
314 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
315 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
316 translate(SSH1_CMSG_AUTH_PASSWORD);
317 translate(SSH1_CMSG_REQUEST_PTY);
318 translate(SSH1_CMSG_WINDOW_SIZE);
319 translate(SSH1_CMSG_EXEC_SHELL);
320 translate(SSH1_CMSG_EXEC_CMD);
321 translate(SSH1_SMSG_SUCCESS);
322 translate(SSH1_SMSG_FAILURE);
323 translate(SSH1_CMSG_STDIN_DATA);
324 translate(SSH1_SMSG_STDOUT_DATA);
325 translate(SSH1_SMSG_STDERR_DATA);
326 translate(SSH1_CMSG_EOF);
327 translate(SSH1_SMSG_EXIT_STATUS);
328 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
329 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
330 translate(SSH1_MSG_CHANNEL_DATA);
331 translate(SSH1_MSG_CHANNEL_CLOSE);
332 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
333 translate(SSH1_SMSG_X11_OPEN);
334 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
335 translate(SSH1_MSG_PORT_OPEN);
336 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
337 translate(SSH1_SMSG_AGENT_OPEN);
338 translate(SSH1_MSG_IGNORE);
339 translate(SSH1_CMSG_EXIT_CONFIRMATION);
340 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
341 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
342 translate(SSH1_MSG_DEBUG);
343 translate(SSH1_CMSG_REQUEST_COMPRESSION);
344 translate(SSH1_CMSG_AUTH_TIS);
345 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
346 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
347 translate(SSH1_CMSG_AUTH_CCARD);
348 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
349 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
352 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
354 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
355 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
356 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
357 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
358 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
359 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
360 translate(SSH2_MSG_DISCONNECT);
361 translate(SSH2_MSG_IGNORE);
362 translate(SSH2_MSG_UNIMPLEMENTED);
363 translate(SSH2_MSG_DEBUG);
364 translate(SSH2_MSG_SERVICE_REQUEST);
365 translate(SSH2_MSG_SERVICE_ACCEPT);
366 translate(SSH2_MSG_KEXINIT);
367 translate(SSH2_MSG_NEWKEYS);
368 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
369 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
370 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
371 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
372 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
373 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
374 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
375 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
376 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
377 translate(SSH2_MSG_USERAUTH_REQUEST);
378 translate(SSH2_MSG_USERAUTH_FAILURE);
379 translate(SSH2_MSG_USERAUTH_SUCCESS);
380 translate(SSH2_MSG_USERAUTH_BANNER);
381 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
382 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
383 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
384 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
385 translate(SSH2_MSG_GLOBAL_REQUEST);
386 translate(SSH2_MSG_REQUEST_SUCCESS);
387 translate(SSH2_MSG_REQUEST_FAILURE);
388 translate(SSH2_MSG_CHANNEL_OPEN);
389 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
390 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
391 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
392 translate(SSH2_MSG_CHANNEL_DATA);
393 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
394 translate(SSH2_MSG_CHANNEL_EOF);
395 translate(SSH2_MSG_CHANNEL_CLOSE);
396 translate(SSH2_MSG_CHANNEL_REQUEST);
397 translate(SSH2_MSG_CHANNEL_SUCCESS);
398 translate(SSH2_MSG_CHANNEL_FAILURE);
404 /* Enumeration values for fields in SSH-1 packets */
406 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
407 /* These values are for communicating relevant semantics of
408 * fields to the packet logging code. */
409 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
413 * Coroutine mechanics for the sillier bits of the code. If these
414 * macros look impenetrable to you, you might find it helpful to
417 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
419 * which explains the theory behind these macros.
421 * In particular, if you are getting `case expression not constant'
422 * errors when building with MS Visual Studio, this is because MS's
423 * Edit and Continue debugging feature causes their compiler to
424 * violate ANSI C. To disable Edit and Continue debugging:
426 * - right-click ssh.c in the FileView
428 * - select the C/C++ tab and the General category
429 * - under `Debug info:', select anything _other_ than `Program
430 * Database for Edit and Continue'.
432 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
435 if (!ssh->t) ssh->t = snew(struct t); \
437 #define crFinish(z) } *crLine = 0; return (z); }
438 #define crFinishV } *crLine = 0; return; }
439 #define crReturn(z) \
441 *crLine =__LINE__; return (z); case __LINE__:;\
445 *crLine=__LINE__; return; case __LINE__:;\
447 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
448 #define crStopV do{ *crLine = 0; return; }while(0)
449 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
450 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
452 typedef struct ssh_tag *Ssh;
455 static struct Packet *ssh1_pkt_init(int pkt_type);
456 static struct Packet *ssh2_pkt_init(int pkt_type);
457 static void ssh_pkt_ensure(struct Packet *, int length);
458 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
459 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
460 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
461 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
462 static void ssh_pkt_addstring_start(struct Packet *);
463 static void ssh_pkt_addstring_str(struct Packet *, char *data);
464 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
465 static void ssh_pkt_addstring(struct Packet *, char *data);
466 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
467 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
468 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
469 static int ssh2_pkt_construct(Ssh, struct Packet *);
470 static void ssh2_pkt_send(Ssh, struct Packet *);
471 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
472 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
473 struct Packet *pktin);
474 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
475 struct Packet *pktin);
478 * Buffer management constants. There are several of these for
479 * various different purposes:
481 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
482 * on a local data stream before we throttle the whole SSH
483 * connection (in SSH-1 only). Throttling the whole connection is
484 * pretty drastic so we set this high in the hope it won't
487 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
488 * on the SSH connection itself before we defensively throttle
489 * _all_ local data streams. This is pretty drastic too (though
490 * thankfully unlikely in SSH-2 since the window mechanism should
491 * ensure that the server never has any need to throttle its end
492 * of the connection), so we set this high as well.
494 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
497 * - OUR_V2_BIGWIN is the window size we advertise for the only
498 * channel in a simple connection. It must be <= INT_MAX.
500 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
501 * to the remote side. This actually has nothing to do with the
502 * size of the _packet_, but is instead a limit on the amount
503 * of data we're willing to receive in a single SSH2 channel
506 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
507 * _packet_ we're prepared to cope with. It must be a multiple
508 * of the cipher block size, and must be at least 35000.
511 #define SSH1_BUFFER_LIMIT 32768
512 #define SSH_MAX_BACKLOG 32768
513 #define OUR_V2_WINSIZE 16384
514 #define OUR_V2_BIGWIN 0x7fffffff
515 #define OUR_V2_MAXPKT 0x4000UL
516 #define OUR_V2_PACKETLIMIT 0x9000UL
518 /* Maximum length of passwords/passphrases (arbitrary) */
519 #define SSH_MAX_PASSWORD_LEN 100
521 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
523 const static struct ssh_mac *macs[] = {
524 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
526 const static struct ssh_mac *buggymacs[] = {
527 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
530 static void *ssh_comp_none_init(void)
534 static void ssh_comp_none_cleanup(void *handle)
537 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
538 unsigned char **outblock, int *outlen)
542 static int ssh_comp_none_disable(void *handle)
546 const static struct ssh_compress ssh_comp_none = {
548 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
549 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
550 ssh_comp_none_disable, NULL
552 extern const struct ssh_compress ssh_zlib;
553 const static struct ssh_compress *compressions[] = {
554 &ssh_zlib, &ssh_comp_none
557 enum { /* channel types */
562 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
566 * little structure to keep track of outstanding WINDOW_ADJUSTs
574 * 2-3-4 tree storing channels.
577 Ssh ssh; /* pointer back to main context */
578 unsigned remoteid, localid;
580 /* True if we opened this channel but server hasn't confirmed. */
583 * In SSH-1, this value contains four bits:
585 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
586 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
587 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
588 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
590 * A channel is completely finished with when all four bits are set.
595 * This flag indicates that a close is pending on the outgoing
596 * side of the channel: that is, wherever we're getting the data
597 * for this channel has sent us some data followed by EOF. We
598 * can't actually close the channel until we've finished sending
599 * the data, so we set this flag instead to remind us to
600 * initiate the closing process once our buffer is clear.
605 * True if this channel is causing the underlying connection to be
610 struct ssh2_data_channel {
612 unsigned remwindow, remmaxpkt;
613 /* locwindow is signed so we can cope with excess data. */
614 int locwindow, locmaxwin;
616 * remlocwin is the amount of local window that we think
617 * the remote end had available to it after it sent the
618 * last data packet or window adjust ack.
622 * These store the list of window adjusts that haven't
625 struct winadj *winadj_head, *winadj_tail;
626 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
630 struct ssh_agent_channel {
631 unsigned char *message;
632 unsigned char msglen[4];
633 unsigned lensofar, totallen;
635 struct ssh_x11_channel {
638 struct ssh_pfd_channel {
645 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
646 * use this structure in different ways, reflecting SSH-2's
647 * altogether saner approach to port forwarding.
649 * In SSH-1, you arrange a remote forwarding by sending the server
650 * the remote port number, and the local destination host:port.
651 * When a connection comes in, the server sends you back that
652 * host:port pair, and you connect to it. This is a ready-made
653 * security hole if you're not on the ball: a malicious server
654 * could send you back _any_ host:port pair, so if you trustingly
655 * connect to the address it gives you then you've just opened the
656 * entire inside of your corporate network just by connecting
657 * through it to a dodgy SSH server. Hence, we must store a list of
658 * host:port pairs we _are_ trying to forward to, and reject a
659 * connection request from the server if it's not in the list.
661 * In SSH-2, each side of the connection minds its own business and
662 * doesn't send unnecessary information to the other. You arrange a
663 * remote forwarding by sending the server just the remote port
664 * number. When a connection comes in, the server tells you which
665 * of its ports was connected to; and _you_ have to remember what
666 * local host:port pair went with that port number.
668 * Hence, in SSH-1 this structure is indexed by destination
669 * host:port pair, whereas in SSH-2 it is indexed by source port.
671 struct ssh_portfwd; /* forward declaration */
673 struct ssh_rportfwd {
674 unsigned sport, dport;
677 struct ssh_portfwd *pfrec;
679 #define free_rportfwd(pf) ( \
680 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
683 * Separately to the rportfwd tree (which is for looking up port
684 * open requests from the server), a tree of _these_ structures is
685 * used to keep track of all the currently open port forwardings,
686 * so that we can reconfigure in mid-session if the user requests
690 enum { DESTROY, KEEP, CREATE } status;
692 unsigned sport, dport;
695 struct ssh_rportfwd *remote;
699 #define free_portfwd(pf) ( \
700 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
701 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
704 long length; /* length of `data' actually used */
705 long forcepad; /* SSH-2: force padding to at least this length */
706 int type; /* only used for incoming packets */
707 unsigned long sequence; /* SSH-2 incoming sequence number */
708 unsigned char *data; /* allocated storage */
709 unsigned char *body; /* offset of payload within `data' */
710 long savedpos; /* temporary index into `data' (for strings) */
711 long maxlen; /* amount of storage allocated for `data' */
712 long encrypted_len; /* for SSH-2 total-size counting */
715 * State associated with packet logging
719 struct logblank_t *blanks;
722 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
723 struct Packet *pktin);
724 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
725 struct Packet *pktin);
726 static void ssh1_protocol_setup(Ssh ssh);
727 static void ssh2_protocol_setup(Ssh ssh);
728 static void ssh_size(void *handle, int width, int height);
729 static void ssh_special(void *handle, Telnet_Special);
730 static int ssh2_try_send(struct ssh_channel *c);
731 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
732 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
733 static void ssh2_set_window(struct ssh_channel *c, int newwin);
734 static int ssh_sendbuffer(void *handle);
735 static int ssh_do_close(Ssh ssh, int notify_exit);
736 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
737 static int ssh2_pkt_getbool(struct Packet *pkt);
738 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
739 static void ssh2_timer(void *ctx, long now);
740 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
741 struct Packet *pktin);
743 struct rdpkt1_state_tag {
744 long len, pad, biglen, to_read;
745 unsigned long realcrc, gotcrc;
749 struct Packet *pktin;
752 struct rdpkt2_state_tag {
753 long len, pad, payload, packetlen, maclen;
756 unsigned long incoming_sequence;
757 struct Packet *pktin;
760 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
761 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
763 struct queued_handler;
764 struct queued_handler {
766 chandler_fn_t handler;
768 struct queued_handler *next;
772 const struct plug_function_table *fn;
773 /* the above field _must_ be first in the structure */
783 unsigned char session_key[32];
785 int v1_remote_protoflags;
786 int v1_local_protoflags;
787 int agentfwd_enabled;
790 const struct ssh_cipher *cipher;
793 const struct ssh2_cipher *cscipher, *sccipher;
794 void *cs_cipher_ctx, *sc_cipher_ctx;
795 const struct ssh_mac *csmac, *scmac;
796 void *cs_mac_ctx, *sc_mac_ctx;
797 const struct ssh_compress *cscomp, *sccomp;
798 void *cs_comp_ctx, *sc_comp_ctx;
799 const struct ssh_kex *kex;
800 const struct ssh_signkey *hostkey;
801 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
802 int v2_session_id_len;
808 int echoing, editing;
812 int ospeed, ispeed; /* temporaries */
813 int term_width, term_height;
815 tree234 *channels; /* indexed by local id */
816 struct ssh_channel *mainchan; /* primary session channel */
817 int ncmode; /* is primary channel direct-tcpip? */
822 tree234 *rportfwds, *portfwds;
826 SSH_STATE_BEFORE_SIZE,
832 int size_needed, eof_needed;
834 struct Packet **queue;
835 int queuelen, queuesize;
837 unsigned char *deferred_send_data;
838 int deferred_len, deferred_size;
841 * Gross hack: pscp will try to start SFTP but fall back to
842 * scp1 if that fails. This variable is the means by which
843 * scp.c can reach into the SSH code and find out which one it
848 bufchain banner; /* accumulates banners during do_ssh2_authconn */
853 struct X11Display *x11disp;
856 int conn_throttle_count;
859 int v1_stdout_throttling;
860 unsigned long v2_outgoing_sequence;
862 int ssh1_rdpkt_crstate;
863 int ssh2_rdpkt_crstate;
864 int do_ssh_init_crstate;
865 int ssh_gotdata_crstate;
866 int do_ssh1_login_crstate;
867 int do_ssh1_connection_crstate;
868 int do_ssh2_transport_crstate;
869 int do_ssh2_authconn_crstate;
871 void *do_ssh_init_state;
872 void *do_ssh1_login_state;
873 void *do_ssh2_transport_state;
874 void *do_ssh2_authconn_state;
876 struct rdpkt1_state_tag rdpkt1_state;
877 struct rdpkt2_state_tag rdpkt2_state;
879 /* SSH-1 and SSH-2 use this for different things, but both use it */
880 int protocol_initial_phase_done;
882 void (*protocol) (Ssh ssh, void *vin, int inlen,
884 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
887 * We maintain a full _copy_ of a Config structure here, not
888 * merely a pointer to it. That way, when we're passed a new
889 * one for reconfiguration, we can check the differences and
890 * potentially reconfigure port forwardings etc in mid-session.
895 * Used to transfer data back from async callbacks.
897 void *agent_response;
898 int agent_response_len;
902 * The SSH connection can be set as `frozen', meaning we are
903 * not currently accepting incoming data from the network. This
904 * is slightly more serious than setting the _socket_ as
905 * frozen, because we may already have had data passed to us
906 * from the network which we need to delay processing until
907 * after the freeze is lifted, so we also need a bufchain to
911 bufchain queued_incoming_data;
914 * Dispatch table for packet types that we may have to deal
917 handler_fn_t packet_dispatch[256];
920 * Queues of one-off handler functions for success/failure
921 * indications from a request.
923 struct queued_handler *qhead, *qtail;
926 * This module deals with sending keepalives.
931 * Track incoming and outgoing data sizes and time, for
934 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
935 unsigned long max_data_size;
937 long next_rekey, last_rekey;
938 char *deferred_rekey_reason; /* points to STATIC string; don't free */
941 * Fully qualified host name, which we need if doing GSSAPI.
947 * GSSAPI libraries for this session.
949 struct ssh_gss_liblist *gsslibs;
953 #define logevent(s) logevent(ssh->frontend, s)
955 /* logevent, only printf-formatted. */
956 static void logeventf(Ssh ssh, const char *fmt, ...)
962 buf = dupvprintf(fmt, ap);
968 #define bombout(msg) \
970 char *text = dupprintf msg; \
971 ssh_do_close(ssh, FALSE); \
973 connection_fatal(ssh->frontend, "%s", text); \
977 /* Functions to leave bits out of the SSH packet log file. */
979 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
981 if (ssh->cfg.logomitpass)
982 pkt->logmode = blanktype;
985 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
987 if (ssh->cfg.logomitdata)
988 pkt->logmode = blanktype;
991 static void end_log_omission(Ssh ssh, struct Packet *pkt)
993 pkt->logmode = PKTLOG_EMIT;
996 /* Helper function for common bits of parsing cfg.ttymodes. */
997 static void parse_ttymodes(Ssh ssh, char *modes,
998 void (*do_mode)(void *data, char *mode, char *val),
1002 char *t = strchr(modes, '\t');
1003 char *m = snewn(t-modes+1, char);
1005 strncpy(m, modes, t-modes);
1008 val = get_ttymode(ssh->frontend, m);
1012 do_mode(data, m, val);
1015 modes += strlen(modes) + 1;
1019 static int ssh_channelcmp(void *av, void *bv)
1021 struct ssh_channel *a = (struct ssh_channel *) av;
1022 struct ssh_channel *b = (struct ssh_channel *) bv;
1023 if (a->localid < b->localid)
1025 if (a->localid > b->localid)
1029 static int ssh_channelfind(void *av, void *bv)
1031 unsigned *a = (unsigned *) av;
1032 struct ssh_channel *b = (struct ssh_channel *) bv;
1033 if (*a < b->localid)
1035 if (*a > b->localid)
1040 static int ssh_rportcmp_ssh1(void *av, void *bv)
1042 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1043 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1045 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1046 return i < 0 ? -1 : +1;
1047 if (a->dport > b->dport)
1049 if (a->dport < b->dport)
1054 static int ssh_rportcmp_ssh2(void *av, void *bv)
1056 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1057 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1059 if (a->sport > b->sport)
1061 if (a->sport < b->sport)
1067 * Special form of strcmp which can cope with NULL inputs. NULL is
1068 * defined to sort before even the empty string.
1070 static int nullstrcmp(const char *a, const char *b)
1072 if (a == NULL && b == NULL)
1078 return strcmp(a, b);
1081 static int ssh_portcmp(void *av, void *bv)
1083 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1084 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1086 if (a->type > b->type)
1088 if (a->type < b->type)
1090 if (a->addressfamily > b->addressfamily)
1092 if (a->addressfamily < b->addressfamily)
1094 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1095 return i < 0 ? -1 : +1;
1096 if (a->sport > b->sport)
1098 if (a->sport < b->sport)
1100 if (a->type != 'D') {
1101 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1102 return i < 0 ? -1 : +1;
1103 if (a->dport > b->dport)
1105 if (a->dport < b->dport)
1111 static int alloc_channel_id(Ssh ssh)
1113 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1114 unsigned low, high, mid;
1116 struct ssh_channel *c;
1119 * First-fit allocation of channel numbers: always pick the
1120 * lowest unused one. To do this, binary-search using the
1121 * counted B-tree to find the largest channel ID which is in a
1122 * contiguous sequence from the beginning. (Precisely
1123 * everything in that sequence must have ID equal to its tree
1124 * index plus CHANNEL_NUMBER_OFFSET.)
1126 tsize = count234(ssh->channels);
1130 while (high - low > 1) {
1131 mid = (high + low) / 2;
1132 c = index234(ssh->channels, mid);
1133 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1134 low = mid; /* this one is fine */
1136 high = mid; /* this one is past it */
1139 * Now low points to either -1, or the tree index of the
1140 * largest ID in the initial sequence.
1143 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1144 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1146 return low + 1 + CHANNEL_NUMBER_OFFSET;
1149 static void c_write_stderr(int trusted, const char *buf, int len)
1152 for (i = 0; i < len; i++)
1153 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1154 fputc(buf[i], stderr);
1157 static void c_write(Ssh ssh, const char *buf, int len)
1159 if (flags & FLAG_STDERR)
1160 c_write_stderr(1, buf, len);
1162 from_backend(ssh->frontend, 1, buf, len);
1165 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1167 if (flags & FLAG_STDERR)
1168 c_write_stderr(0, buf, len);
1170 from_backend_untrusted(ssh->frontend, buf, len);
1173 static void c_write_str(Ssh ssh, const char *buf)
1175 c_write(ssh, buf, strlen(buf));
1178 static void ssh_free_packet(struct Packet *pkt)
1183 static struct Packet *ssh_new_packet(void)
1185 struct Packet *pkt = snew(struct Packet);
1187 pkt->body = pkt->data = NULL;
1189 pkt->logmode = PKTLOG_EMIT;
1197 * Collect incoming data in the incoming packet buffer.
1198 * Decipher and verify the packet when it is completely read.
1199 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1200 * Update the *data and *datalen variables.
1201 * Return a Packet structure when a packet is completed.
1203 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1205 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1207 crBegin(ssh->ssh1_rdpkt_crstate);
1209 st->pktin = ssh_new_packet();
1211 st->pktin->type = 0;
1212 st->pktin->length = 0;
1214 for (st->i = st->len = 0; st->i < 4; st->i++) {
1215 while ((*datalen) == 0)
1217 st->len = (st->len << 8) + **data;
1218 (*data)++, (*datalen)--;
1221 st->pad = 8 - (st->len % 8);
1222 st->biglen = st->len + st->pad;
1223 st->pktin->length = st->len - 5;
1225 if (st->biglen < 0) {
1226 bombout(("Extremely large packet length from server suggests"
1227 " data stream corruption"));
1228 ssh_free_packet(st->pktin);
1232 st->pktin->maxlen = st->biglen;
1233 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1235 st->to_read = st->biglen;
1236 st->p = st->pktin->data;
1237 while (st->to_read > 0) {
1238 st->chunk = st->to_read;
1239 while ((*datalen) == 0)
1241 if (st->chunk > (*datalen))
1242 st->chunk = (*datalen);
1243 memcpy(st->p, *data, st->chunk);
1245 *datalen -= st->chunk;
1247 st->to_read -= st->chunk;
1250 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1251 st->biglen, NULL)) {
1252 bombout(("Network attack (CRC compensation) detected!"));
1253 ssh_free_packet(st->pktin);
1258 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1260 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1261 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1262 if (st->gotcrc != st->realcrc) {
1263 bombout(("Incorrect CRC received on packet"));
1264 ssh_free_packet(st->pktin);
1268 st->pktin->body = st->pktin->data + st->pad + 1;
1269 st->pktin->savedpos = 0;
1271 if (ssh->v1_compressing) {
1272 unsigned char *decompblk;
1274 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1275 st->pktin->body - 1, st->pktin->length + 1,
1276 &decompblk, &decomplen)) {
1277 bombout(("Zlib decompression encountered invalid data"));
1278 ssh_free_packet(st->pktin);
1282 if (st->pktin->maxlen < st->pad + decomplen) {
1283 st->pktin->maxlen = st->pad + decomplen;
1284 st->pktin->data = sresize(st->pktin->data,
1285 st->pktin->maxlen + APIEXTRA,
1287 st->pktin->body = st->pktin->data + st->pad + 1;
1290 memcpy(st->pktin->body - 1, decompblk, decomplen);
1292 st->pktin->length = decomplen - 1;
1295 st->pktin->type = st->pktin->body[-1];
1298 * Log incoming packet, possibly omitting sensitive fields.
1302 struct logblank_t blank;
1303 if (ssh->cfg.logomitdata) {
1304 int do_blank = FALSE, blank_prefix = 0;
1305 /* "Session data" packets - omit the data field */
1306 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1307 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1308 do_blank = TRUE; blank_prefix = 4;
1309 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1310 do_blank = TRUE; blank_prefix = 8;
1313 blank.offset = blank_prefix;
1314 blank.len = st->pktin->length;
1315 blank.type = PKTLOG_OMIT;
1319 log_packet(ssh->logctx,
1320 PKT_INCOMING, st->pktin->type,
1321 ssh1_pkt_type(st->pktin->type),
1322 st->pktin->body, st->pktin->length,
1323 nblanks, &blank, NULL);
1326 crFinish(st->pktin);
1329 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1331 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1333 crBegin(ssh->ssh2_rdpkt_crstate);
1335 st->pktin = ssh_new_packet();
1337 st->pktin->type = 0;
1338 st->pktin->length = 0;
1340 st->cipherblk = ssh->sccipher->blksize;
1343 if (st->cipherblk < 8)
1345 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1347 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1350 * When dealing with a CBC-mode cipher, we want to avoid the
1351 * possibility of an attacker's tweaking the ciphertext stream
1352 * so as to cause us to feed the same block to the block
1353 * cipher more than once and thus leak information
1354 * (VU#958563). The way we do this is not to take any
1355 * decisions on the basis of anything we've decrypted until
1356 * we've verified it with a MAC. That includes the packet
1357 * length, so we just read data and check the MAC repeatedly,
1358 * and when the MAC passes, see if the length we've got is
1362 /* May as well allocate the whole lot now. */
1363 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1366 /* Read an amount corresponding to the MAC. */
1367 for (st->i = 0; st->i < st->maclen; st->i++) {
1368 while ((*datalen) == 0)
1370 st->pktin->data[st->i] = *(*data)++;
1376 unsigned char seq[4];
1377 ssh->scmac->start(ssh->sc_mac_ctx);
1378 PUT_32BIT(seq, st->incoming_sequence);
1379 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1382 for (;;) { /* Once around this loop per cipher block. */
1383 /* Read another cipher-block's worth, and tack it onto the end. */
1384 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1385 while ((*datalen) == 0)
1387 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1390 /* Decrypt one more block (a little further back in the stream). */
1391 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1392 st->pktin->data + st->packetlen,
1394 /* Feed that block to the MAC. */
1395 ssh->scmac->bytes(ssh->sc_mac_ctx,
1396 st->pktin->data + st->packetlen, st->cipherblk);
1397 st->packetlen += st->cipherblk;
1398 /* See if that gives us a valid packet. */
1399 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1400 st->pktin->data + st->packetlen) &&
1401 (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen)
1403 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1404 bombout(("No valid incoming packet found"));
1405 ssh_free_packet(st->pktin);
1409 st->pktin->maxlen = st->packetlen + st->maclen;
1410 st->pktin->data = sresize(st->pktin->data,
1411 st->pktin->maxlen + APIEXTRA,
1414 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1417 * Acquire and decrypt the first block of the packet. This will
1418 * contain the length and padding details.
1420 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1421 while ((*datalen) == 0)
1423 st->pktin->data[st->i] = *(*data)++;
1428 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1429 st->pktin->data, st->cipherblk);
1432 * Now get the length figure.
1434 st->len = GET_32BIT(st->pktin->data);
1437 * _Completely_ silly lengths should be stomped on before they
1438 * do us any more damage.
1440 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1441 (st->len + 4) % st->cipherblk != 0) {
1442 bombout(("Incoming packet was garbled on decryption"));
1443 ssh_free_packet(st->pktin);
1448 * So now we can work out the total packet length.
1450 st->packetlen = st->len + 4;
1453 * Allocate memory for the rest of the packet.
1455 st->pktin->maxlen = st->packetlen + st->maclen;
1456 st->pktin->data = sresize(st->pktin->data,
1457 st->pktin->maxlen + APIEXTRA,
1461 * Read and decrypt the remainder of the packet.
1463 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1465 while ((*datalen) == 0)
1467 st->pktin->data[st->i] = *(*data)++;
1470 /* Decrypt everything _except_ the MAC. */
1472 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1473 st->pktin->data + st->cipherblk,
1474 st->packetlen - st->cipherblk);
1480 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1481 st->len + 4, st->incoming_sequence)) {
1482 bombout(("Incorrect MAC received on packet"));
1483 ssh_free_packet(st->pktin);
1487 /* Get and sanity-check the amount of random padding. */
1488 st->pad = st->pktin->data[4];
1489 if (st->pad < 4 || st->len - st->pad < 1) {
1490 bombout(("Invalid padding length on received packet"));
1491 ssh_free_packet(st->pktin);
1495 * This enables us to deduce the payload length.
1497 st->payload = st->len - st->pad - 1;
1499 st->pktin->length = st->payload + 5;
1500 st->pktin->encrypted_len = st->packetlen;
1502 st->pktin->sequence = st->incoming_sequence++;
1505 * Decompress packet payload.
1508 unsigned char *newpayload;
1511 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1512 st->pktin->data + 5, st->pktin->length - 5,
1513 &newpayload, &newlen)) {
1514 if (st->pktin->maxlen < newlen + 5) {
1515 st->pktin->maxlen = newlen + 5;
1516 st->pktin->data = sresize(st->pktin->data,
1517 st->pktin->maxlen + APIEXTRA,
1520 st->pktin->length = 5 + newlen;
1521 memcpy(st->pktin->data + 5, newpayload, newlen);
1526 st->pktin->savedpos = 6;
1527 st->pktin->body = st->pktin->data;
1528 st->pktin->type = st->pktin->data[5];
1531 * Log incoming packet, possibly omitting sensitive fields.
1535 struct logblank_t blank;
1536 if (ssh->cfg.logomitdata) {
1537 int do_blank = FALSE, blank_prefix = 0;
1538 /* "Session data" packets - omit the data field */
1539 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1540 do_blank = TRUE; blank_prefix = 8;
1541 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1542 do_blank = TRUE; blank_prefix = 12;
1545 blank.offset = blank_prefix;
1546 blank.len = (st->pktin->length-6) - blank_prefix;
1547 blank.type = PKTLOG_OMIT;
1551 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1552 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1554 st->pktin->data+6, st->pktin->length-6,
1555 nblanks, &blank, &st->pktin->sequence);
1558 crFinish(st->pktin);
1561 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1563 int pad, biglen, i, pktoffs;
1567 * XXX various versions of SC (including 8.8.4) screw up the
1568 * register allocation in this function and use the same register
1569 * (D6) for len and as a temporary, with predictable results. The
1570 * following sledgehammer prevents this.
1577 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1578 ssh1_pkt_type(pkt->data[12]),
1579 pkt->body, pkt->length - (pkt->body - pkt->data),
1580 pkt->nblanks, pkt->blanks, NULL);
1581 sfree(pkt->blanks); pkt->blanks = NULL;
1584 if (ssh->v1_compressing) {
1585 unsigned char *compblk;
1587 zlib_compress_block(ssh->cs_comp_ctx,
1588 pkt->data + 12, pkt->length - 12,
1589 &compblk, &complen);
1590 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1591 memcpy(pkt->data + 12, compblk, complen);
1593 pkt->length = complen + 12;
1596 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1598 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1599 pad = 8 - (len % 8);
1601 biglen = len + pad; /* len(padding+type+data+CRC) */
1603 for (i = pktoffs; i < 4+8; i++)
1604 pkt->data[i] = random_byte();
1605 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1606 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1607 PUT_32BIT(pkt->data + pktoffs, len);
1610 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1611 pkt->data + pktoffs + 4, biglen);
1613 if (offset_p) *offset_p = pktoffs;
1614 return biglen + 4; /* len(length+padding+type+data+CRC) */
1617 static int s_write(Ssh ssh, void *data, int len)
1620 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1622 return sk_write(ssh->s, (char *)data, len);
1625 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1627 int len, backlog, offset;
1628 len = s_wrpkt_prepare(ssh, pkt, &offset);
1629 backlog = s_write(ssh, pkt->data + offset, len);
1630 if (backlog > SSH_MAX_BACKLOG)
1631 ssh_throttle_all(ssh, 1, backlog);
1632 ssh_free_packet(pkt);
1635 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1638 len = s_wrpkt_prepare(ssh, pkt, &offset);
1639 if (ssh->deferred_len + len > ssh->deferred_size) {
1640 ssh->deferred_size = ssh->deferred_len + len + 128;
1641 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1645 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1646 pkt->data + offset, len);
1647 ssh->deferred_len += len;
1648 ssh_free_packet(pkt);
1652 * Construct a SSH-1 packet with the specified contents.
1653 * (This all-at-once interface used to be the only one, but now SSH-1
1654 * packets can also be constructed incrementally.)
1656 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1662 pkt = ssh1_pkt_init(pkttype);
1664 while ((argtype = va_arg(ap, int)) != PKT_END) {
1665 unsigned char *argp, argchar;
1667 unsigned long argint;
1670 /* Actual fields in the packet */
1672 argint = va_arg(ap, int);
1673 ssh_pkt_adduint32(pkt, argint);
1676 argchar = (unsigned char) va_arg(ap, int);
1677 ssh_pkt_addbyte(pkt, argchar);
1680 argp = va_arg(ap, unsigned char *);
1681 arglen = va_arg(ap, int);
1682 ssh_pkt_adddata(pkt, argp, arglen);
1685 sargp = va_arg(ap, char *);
1686 ssh_pkt_addstring(pkt, sargp);
1689 bn = va_arg(ap, Bignum);
1690 ssh1_pkt_addmp(pkt, bn);
1692 /* Tokens for modifications to packet logging */
1694 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1697 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1700 end_log_omission(ssh, pkt);
1708 static void send_packet(Ssh ssh, int pkttype, ...)
1712 va_start(ap, pkttype);
1713 pkt = construct_packet(ssh, pkttype, ap);
1718 static void defer_packet(Ssh ssh, int pkttype, ...)
1722 va_start(ap, pkttype);
1723 pkt = construct_packet(ssh, pkttype, ap);
1725 s_wrpkt_defer(ssh, pkt);
1728 static int ssh_versioncmp(char *a, char *b)
1731 unsigned long av, bv;
1733 av = strtoul(a, &ae, 10);
1734 bv = strtoul(b, &be, 10);
1736 return (av < bv ? -1 : +1);
1741 av = strtoul(ae, &ae, 10);
1742 bv = strtoul(be, &be, 10);
1744 return (av < bv ? -1 : +1);
1749 * Utility routines for putting an SSH-protocol `string' and
1750 * `uint32' into a hash state.
1752 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1754 unsigned char lenblk[4];
1755 PUT_32BIT(lenblk, len);
1756 h->bytes(s, lenblk, 4);
1757 h->bytes(s, str, len);
1760 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1762 unsigned char intblk[4];
1763 PUT_32BIT(intblk, i);
1764 h->bytes(s, intblk, 4);
1768 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1770 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1772 if (pkt->maxlen < length) {
1773 unsigned char *body = pkt->body;
1774 int offset = body ? body - pkt->data : 0;
1775 pkt->maxlen = length + 256;
1776 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1777 if (body) pkt->body = pkt->data + offset;
1780 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1782 if (pkt->logmode != PKTLOG_EMIT) {
1784 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1786 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1787 (pkt->body - pkt->data);
1788 pkt->blanks[pkt->nblanks-1].len = len;
1789 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1792 ssh_pkt_ensure(pkt, pkt->length);
1793 memcpy(pkt->data + pkt->length - len, data, len);
1795 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1797 ssh_pkt_adddata(pkt, &byte, 1);
1799 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1801 ssh_pkt_adddata(pkt, &value, 1);
1803 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1806 PUT_32BIT(x, value);
1807 ssh_pkt_adddata(pkt, x, 4);
1809 static void ssh_pkt_addstring_start(struct Packet *pkt)
1811 ssh_pkt_adduint32(pkt, 0);
1812 pkt->savedpos = pkt->length;
1814 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1816 ssh_pkt_adddata(pkt, data, strlen(data));
1817 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1819 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1821 ssh_pkt_adddata(pkt, data, len);
1822 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1824 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1826 ssh_pkt_addstring_start(pkt);
1827 ssh_pkt_addstring_str(pkt, data);
1829 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1831 int len = ssh1_bignum_length(b);
1832 unsigned char *data = snewn(len, unsigned char);
1833 (void) ssh1_write_bignum(data, b);
1834 ssh_pkt_adddata(pkt, data, len);
1837 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1840 int i, n = (bignum_bitcount(b) + 7) / 8;
1841 p = snewn(n + 1, unsigned char);
1843 for (i = 1; i <= n; i++)
1844 p[i] = bignum_byte(b, n - i);
1846 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1848 memmove(p, p + i, n + 1 - i);
1852 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1856 p = ssh2_mpint_fmt(b, &len);
1857 ssh_pkt_addstring_start(pkt);
1858 ssh_pkt_addstring_data(pkt, (char *)p, len);
1862 static struct Packet *ssh1_pkt_init(int pkt_type)
1864 struct Packet *pkt = ssh_new_packet();
1865 pkt->length = 4 + 8; /* space for length + max padding */
1866 ssh_pkt_addbyte(pkt, pkt_type);
1867 pkt->body = pkt->data + pkt->length;
1871 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1872 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1873 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1874 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1875 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1876 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1877 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1878 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1879 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1881 static struct Packet *ssh2_pkt_init(int pkt_type)
1883 struct Packet *pkt = ssh_new_packet();
1884 pkt->length = 5; /* space for packet length + padding length */
1886 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1887 pkt->body = pkt->data + pkt->length; /* after packet type */
1892 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1893 * put the MAC on it. Final packet, ready to be sent, is stored in
1894 * pkt->data. Total length is returned.
1896 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1898 int cipherblk, maclen, padding, i;
1901 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1902 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1903 pkt->body, pkt->length - (pkt->body - pkt->data),
1904 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
1905 sfree(pkt->blanks); pkt->blanks = NULL;
1909 * Compress packet payload.
1912 unsigned char *newpayload;
1915 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1917 &newpayload, &newlen)) {
1919 ssh2_pkt_adddata(pkt, newpayload, newlen);
1925 * Add padding. At least four bytes, and must also bring total
1926 * length (minus MAC) up to a multiple of the block size.
1927 * If pkt->forcepad is set, make sure the packet is at least that size
1930 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1931 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1933 if (pkt->length + padding < pkt->forcepad)
1934 padding = pkt->forcepad - pkt->length;
1936 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1937 assert(padding <= 255);
1938 maclen = ssh->csmac ? ssh->csmac->len : 0;
1939 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1940 pkt->data[4] = padding;
1941 for (i = 0; i < padding; i++)
1942 pkt->data[pkt->length + i] = random_byte();
1943 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1945 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1946 pkt->length + padding,
1947 ssh->v2_outgoing_sequence);
1948 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1951 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1952 pkt->data, pkt->length + padding);
1954 pkt->encrypted_len = pkt->length + padding;
1956 /* Ready-to-send packet starts at pkt->data. We return length. */
1957 return pkt->length + padding + maclen;
1961 * Routines called from the main SSH code to send packets. There
1962 * are quite a few of these, because we have two separate
1963 * mechanisms for delaying the sending of packets:
1965 * - In order to send an IGNORE message and a password message in
1966 * a single fixed-length blob, we require the ability to
1967 * concatenate the encrypted forms of those two packets _into_ a
1968 * single blob and then pass it to our <network.h> transport
1969 * layer in one go. Hence, there's a deferment mechanism which
1970 * works after packet encryption.
1972 * - In order to avoid sending any connection-layer messages
1973 * during repeat key exchange, we have to queue up any such
1974 * outgoing messages _before_ they are encrypted (and in
1975 * particular before they're allocated sequence numbers), and
1976 * then send them once we've finished.
1978 * I call these mechanisms `defer' and `queue' respectively, so as
1979 * to distinguish them reasonably easily.
1981 * The functions send_noqueue() and defer_noqueue() free the packet
1982 * structure they are passed. Every outgoing packet goes through
1983 * precisely one of these functions in its life; packets passed to
1984 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1985 * these or get queued, and then when the queue is later emptied
1986 * the packets are all passed to defer_noqueue().
1988 * When using a CBC-mode cipher, it's necessary to ensure that an
1989 * attacker can't provide data to be encrypted using an IV that they
1990 * know. We ensure this by prefixing each packet that might contain
1991 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1992 * mechanism, so in this case send_noqueue() ends up redirecting to
1993 * defer_noqueue(). If you don't like this inefficiency, don't use
1997 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1998 static void ssh_pkt_defersend(Ssh);
2001 * Send an SSH-2 packet immediately, without queuing or deferring.
2003 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2007 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2008 /* We need to send two packets, so use the deferral mechanism. */
2009 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2010 ssh_pkt_defersend(ssh);
2013 len = ssh2_pkt_construct(ssh, pkt);
2014 backlog = s_write(ssh, pkt->data, len);
2015 if (backlog > SSH_MAX_BACKLOG)
2016 ssh_throttle_all(ssh, 1, backlog);
2018 ssh->outgoing_data_size += pkt->encrypted_len;
2019 if (!ssh->kex_in_progress &&
2020 ssh->max_data_size != 0 &&
2021 ssh->outgoing_data_size > ssh->max_data_size)
2022 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2024 ssh_free_packet(pkt);
2028 * Defer an SSH-2 packet.
2030 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2033 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2034 ssh->deferred_len == 0 && !noignore &&
2035 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2037 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2038 * get encrypted with a known IV.
2040 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2041 ssh2_pkt_addstring_start(ipkt);
2042 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2044 len = ssh2_pkt_construct(ssh, pkt);
2045 if (ssh->deferred_len + len > ssh->deferred_size) {
2046 ssh->deferred_size = ssh->deferred_len + len + 128;
2047 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2051 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
2052 ssh->deferred_len += len;
2053 ssh->deferred_data_size += pkt->encrypted_len;
2054 ssh_free_packet(pkt);
2058 * Queue an SSH-2 packet.
2060 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2062 assert(ssh->queueing);
2064 if (ssh->queuelen >= ssh->queuesize) {
2065 ssh->queuesize = ssh->queuelen + 32;
2066 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2069 ssh->queue[ssh->queuelen++] = pkt;
2073 * Either queue or send a packet, depending on whether queueing is
2076 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2079 ssh2_pkt_queue(ssh, pkt);
2081 ssh2_pkt_send_noqueue(ssh, pkt);
2085 * Either queue or defer a packet, depending on whether queueing is
2088 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2091 ssh2_pkt_queue(ssh, pkt);
2093 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2097 * Send the whole deferred data block constructed by
2098 * ssh2_pkt_defer() or SSH-1's defer_packet().
2100 * The expected use of the defer mechanism is that you call
2101 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2102 * not currently queueing, this simply sets up deferred_send_data
2103 * and then sends it. If we _are_ currently queueing, the calls to
2104 * ssh2_pkt_defer() put the deferred packets on to the queue
2105 * instead, and therefore ssh_pkt_defersend() has no deferred data
2106 * to send. Hence, there's no need to make it conditional on
2109 static void ssh_pkt_defersend(Ssh ssh)
2112 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2113 ssh->deferred_len = ssh->deferred_size = 0;
2114 sfree(ssh->deferred_send_data);
2115 ssh->deferred_send_data = NULL;
2116 if (backlog > SSH_MAX_BACKLOG)
2117 ssh_throttle_all(ssh, 1, backlog);
2119 ssh->outgoing_data_size += ssh->deferred_data_size;
2120 if (!ssh->kex_in_progress &&
2121 ssh->max_data_size != 0 &&
2122 ssh->outgoing_data_size > ssh->max_data_size)
2123 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2124 ssh->deferred_data_size = 0;
2128 * Send a packet whose length needs to be disguised (typically
2129 * passwords or keyboard-interactive responses).
2131 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2137 * The simplest way to do this is to adjust the
2138 * variable-length padding field in the outgoing packet.
2140 * Currently compiled out, because some Cisco SSH servers
2141 * don't like excessively padded packets (bah, why's it
2144 pkt->forcepad = padsize;
2145 ssh2_pkt_send(ssh, pkt);
2150 * If we can't do that, however, an alternative approach is
2151 * to use the pkt_defer mechanism to bundle the packet
2152 * tightly together with an SSH_MSG_IGNORE such that their
2153 * combined length is a constant. So first we construct the
2154 * final form of this packet and defer its sending.
2156 ssh2_pkt_defer(ssh, pkt);
2159 * Now construct an SSH_MSG_IGNORE which includes a string
2160 * that's an exact multiple of the cipher block size. (If
2161 * the cipher is NULL so that the block size is
2162 * unavailable, we don't do this trick at all, because we
2163 * gain nothing by it.)
2165 if (ssh->cscipher &&
2166 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2169 stringlen = (256 - ssh->deferred_len);
2170 stringlen += ssh->cscipher->blksize - 1;
2171 stringlen -= (stringlen % ssh->cscipher->blksize);
2174 * Temporarily disable actual compression, so we
2175 * can guarantee to get this string exactly the
2176 * length we want it. The compression-disabling
2177 * routine should return an integer indicating how
2178 * many bytes we should adjust our string length
2182 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2184 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2185 ssh2_pkt_addstring_start(pkt);
2186 for (i = 0; i < stringlen; i++) {
2187 char c = (char) random_byte();
2188 ssh2_pkt_addstring_data(pkt, &c, 1);
2190 ssh2_pkt_defer(ssh, pkt);
2192 ssh_pkt_defersend(ssh);
2197 * Send all queued SSH-2 packets. We send them by means of
2198 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2199 * packets that needed to be lumped together.
2201 static void ssh2_pkt_queuesend(Ssh ssh)
2205 assert(!ssh->queueing);
2207 for (i = 0; i < ssh->queuelen; i++)
2208 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2211 ssh_pkt_defersend(ssh);
2215 void bndebug(char *string, Bignum b)
2219 p = ssh2_mpint_fmt(b, &len);
2220 debug(("%s", string));
2221 for (i = 0; i < len; i++)
2222 debug((" %02x", p[i]));
2228 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2232 p = ssh2_mpint_fmt(b, &len);
2233 hash_string(h, s, p, len);
2238 * Packet decode functions for both SSH-1 and SSH-2.
2240 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2242 unsigned long value;
2243 if (pkt->length - pkt->savedpos < 4)
2244 return 0; /* arrgh, no way to decline (FIXME?) */
2245 value = GET_32BIT(pkt->body + pkt->savedpos);
2249 static int ssh2_pkt_getbool(struct Packet *pkt)
2251 unsigned long value;
2252 if (pkt->length - pkt->savedpos < 1)
2253 return 0; /* arrgh, no way to decline (FIXME?) */
2254 value = pkt->body[pkt->savedpos] != 0;
2258 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2263 if (pkt->length - pkt->savedpos < 4)
2265 len = GET_32BIT(pkt->body + pkt->savedpos);
2270 if (pkt->length - pkt->savedpos < *length)
2272 *p = (char *)(pkt->body + pkt->savedpos);
2273 pkt->savedpos += *length;
2275 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2277 if (pkt->length - pkt->savedpos < length)
2279 pkt->savedpos += length;
2280 return pkt->body + (pkt->savedpos - length);
2282 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2283 unsigned char **keystr)
2287 j = makekey(pkt->body + pkt->savedpos,
2288 pkt->length - pkt->savedpos,
2295 assert(pkt->savedpos < pkt->length);
2299 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2304 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2305 pkt->length - pkt->savedpos, &b);
2313 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2319 ssh_pkt_getstring(pkt, &p, &length);
2324 b = bignum_from_bytes((unsigned char *)p, length);
2329 * Helper function to add an SSH-2 signature blob to a packet.
2330 * Expects to be shown the public key blob as well as the signature
2331 * blob. Normally works just like ssh2_pkt_addstring, but will
2332 * fiddle with the signature packet if necessary for
2333 * BUG_SSH2_RSA_PADDING.
2335 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2336 void *pkblob_v, int pkblob_len,
2337 void *sigblob_v, int sigblob_len)
2339 unsigned char *pkblob = (unsigned char *)pkblob_v;
2340 unsigned char *sigblob = (unsigned char *)sigblob_v;
2342 /* dmemdump(pkblob, pkblob_len); */
2343 /* dmemdump(sigblob, sigblob_len); */
2346 * See if this is in fact an ssh-rsa signature and a buggy
2347 * server; otherwise we can just do this the easy way.
2349 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2350 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2351 int pos, len, siglen;
2354 * Find the byte length of the modulus.
2357 pos = 4+7; /* skip over "ssh-rsa" */
2358 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2359 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2360 pos += 4; /* find modulus itself */
2361 while (len > 0 && pkblob[pos] == 0)
2363 /* debug(("modulus length is %d\n", len)); */
2366 * Now find the signature integer.
2368 pos = 4+7; /* skip over "ssh-rsa" */
2369 siglen = GET_32BIT(sigblob+pos);
2370 /* debug(("signature length is %d\n", siglen)); */
2372 if (len != siglen) {
2373 unsigned char newlen[4];
2374 ssh2_pkt_addstring_start(pkt);
2375 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2376 /* dmemdump(sigblob, pos); */
2377 pos += 4; /* point to start of actual sig */
2378 PUT_32BIT(newlen, len);
2379 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2380 /* dmemdump(newlen, 4); */
2382 while (len-- > siglen) {
2383 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2384 /* dmemdump(newlen, 1); */
2386 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2387 /* dmemdump(sigblob+pos, siglen); */
2391 /* Otherwise fall through and do it the easy way. */
2394 ssh2_pkt_addstring_start(pkt);
2395 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2399 * Examine the remote side's version string and compare it against
2400 * a list of known buggy implementations.
2402 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2404 char *imp; /* pointer to implementation part */
2406 imp += strcspn(imp, "-");
2408 imp += strcspn(imp, "-");
2411 ssh->remote_bugs = 0;
2414 * General notes on server version strings:
2415 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2416 * here -- in particular, we've heard of one that's perfectly happy
2417 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2418 * so we can't distinguish them.
2420 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2421 (ssh->cfg.sshbug_ignore1 == AUTO &&
2422 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2423 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2424 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2425 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2427 * These versions don't support SSH1_MSG_IGNORE, so we have
2428 * to use a different defence against password length
2431 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2432 logevent("We believe remote version has SSH-1 ignore bug");
2435 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2436 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2437 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2439 * These versions need a plain password sent; they can't
2440 * handle having a null and a random length of data after
2443 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2444 logevent("We believe remote version needs a plain SSH-1 password");
2447 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2448 (ssh->cfg.sshbug_rsa1 == AUTO &&
2449 (!strcmp(imp, "Cisco-1.25")))) {
2451 * These versions apparently have no clue whatever about
2452 * RSA authentication and will panic and die if they see
2453 * an AUTH_RSA message.
2455 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2456 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2459 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2460 (ssh->cfg.sshbug_hmac2 == AUTO &&
2461 !wc_match("* VShell", imp) &&
2462 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2463 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2464 wc_match("2.1 *", imp)))) {
2466 * These versions have the HMAC bug.
2468 ssh->remote_bugs |= BUG_SSH2_HMAC;
2469 logevent("We believe remote version has SSH-2 HMAC bug");
2472 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2473 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2474 !wc_match("* VShell", imp) &&
2475 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2477 * These versions have the key-derivation bug (failing to
2478 * include the literal shared secret in the hashes that
2479 * generate the keys).
2481 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2482 logevent("We believe remote version has SSH-2 key-derivation bug");
2485 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2486 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2487 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2488 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2490 * These versions have the SSH-2 RSA padding bug.
2492 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2493 logevent("We believe remote version has SSH-2 RSA padding bug");
2496 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2497 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2498 wc_match("OpenSSH_2.[0-2]*", imp))) {
2500 * These versions have the SSH-2 session-ID bug in
2501 * public-key authentication.
2503 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2504 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2507 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2508 (ssh->cfg.sshbug_rekey2 == AUTO &&
2509 (wc_match("DigiSSH_2.0", imp) ||
2510 wc_match("OpenSSH_2.[0-4]*", imp) ||
2511 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2512 wc_match("Sun_SSH_1.0", imp) ||
2513 wc_match("Sun_SSH_1.0.1", imp) ||
2514 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2515 wc_match("WeOnlyDo-*", imp)))) {
2517 * These versions have the SSH-2 rekey bug.
2519 ssh->remote_bugs |= BUG_SSH2_REKEY;
2520 logevent("We believe remote version has SSH-2 rekey bug");
2523 if (ssh->cfg.sshbug_maxpkt2 == FORCE_ON ||
2524 (ssh->cfg.sshbug_maxpkt2 == AUTO &&
2525 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2526 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2528 * This version ignores our makpkt and needs to be throttled.
2530 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2531 logevent("We believe remote version ignores SSH-2 maximum packet size");
2534 if (ssh->cfg.sshbug_ignore2 == FORCE_ON) {
2536 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2537 * none detected automatically.
2539 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2540 logevent("We believe remote version has SSH-2 ignore bug");
2545 * The `software version' part of an SSH version string is required
2546 * to contain no spaces or minus signs.
2548 static void ssh_fix_verstring(char *str)
2550 /* Eat "SSH-<protoversion>-". */
2551 assert(*str == 'S'); str++;
2552 assert(*str == 'S'); str++;
2553 assert(*str == 'H'); str++;
2554 assert(*str == '-'); str++;
2555 while (*str && *str != '-') str++;
2556 assert(*str == '-'); str++;
2558 /* Convert minus signs and spaces in the remaining string into
2561 if (*str == '-' || *str == ' ')
2568 * Send an appropriate SSH version string.
2570 static void ssh_send_verstring(Ssh ssh, char *svers)
2574 if (ssh->version == 2) {
2576 * Construct a v2 version string.
2578 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2581 * Construct a v1 version string.
2583 verstring = dupprintf("SSH-%s-%s\012",
2584 (ssh_versioncmp(svers, "1.5") <= 0 ?
2589 ssh_fix_verstring(verstring);
2591 if (ssh->version == 2) {
2594 * Record our version string.
2596 len = strcspn(verstring, "\015\012");
2597 ssh->v_c = snewn(len + 1, char);
2598 memcpy(ssh->v_c, verstring, len);
2602 logeventf(ssh, "We claim version: %.*s",
2603 strcspn(verstring, "\015\012"), verstring);
2604 s_write(ssh, verstring, strlen(verstring));
2608 static int do_ssh_init(Ssh ssh, unsigned char c)
2610 struct do_ssh_init_state {
2618 crState(do_ssh_init_state);
2620 crBegin(ssh->do_ssh_init_crstate);
2622 /* Search for a line beginning with the string "SSH-" in the input. */
2624 if (c != 'S') goto no;
2626 if (c != 'S') goto no;
2628 if (c != 'H') goto no;
2630 if (c != '-') goto no;
2639 s->vstring = snewn(s->vstrsize, char);
2640 strcpy(s->vstring, "SSH-");
2644 crReturn(1); /* get another char */
2645 if (s->vslen >= s->vstrsize - 1) {
2647 s->vstring = sresize(s->vstring, s->vstrsize, char);
2649 s->vstring[s->vslen++] = c;
2652 s->version[s->i] = '\0';
2654 } else if (s->i < sizeof(s->version) - 1)
2655 s->version[s->i++] = c;
2656 } else if (c == '\012')
2660 ssh->agentfwd_enabled = FALSE;
2661 ssh->rdpkt2_state.incoming_sequence = 0;
2663 s->vstring[s->vslen] = 0;
2664 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2665 logeventf(ssh, "Server version: %s", s->vstring);
2666 ssh_detect_bugs(ssh, s->vstring);
2669 * Decide which SSH protocol version to support.
2672 /* Anything strictly below "2.0" means protocol 1 is supported. */
2673 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2674 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2675 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2677 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2678 bombout(("SSH protocol version 1 required by user but not provided by server"));
2681 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2682 bombout(("SSH protocol version 2 required by user but not provided by server"));
2686 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1))
2691 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2693 /* Send the version string, if we haven't already */
2694 if (ssh->cfg.sshprot != 3)
2695 ssh_send_verstring(ssh, s->version);
2697 if (ssh->version == 2) {
2700 * Record their version string.
2702 len = strcspn(s->vstring, "\015\012");
2703 ssh->v_s = snewn(len + 1, char);
2704 memcpy(ssh->v_s, s->vstring, len);
2708 * Initialise SSH-2 protocol.
2710 ssh->protocol = ssh2_protocol;
2711 ssh2_protocol_setup(ssh);
2712 ssh->s_rdpkt = ssh2_rdpkt;
2715 * Initialise SSH-1 protocol.
2717 ssh->protocol = ssh1_protocol;
2718 ssh1_protocol_setup(ssh);
2719 ssh->s_rdpkt = ssh1_rdpkt;
2721 if (ssh->version == 2)
2722 do_ssh2_transport(ssh, NULL, -1, NULL);
2724 update_specials_menu(ssh->frontend);
2725 ssh->state = SSH_STATE_BEFORE_SIZE;
2726 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2733 static void ssh_process_incoming_data(Ssh ssh,
2734 unsigned char **data, int *datalen)
2736 struct Packet *pktin;
2738 pktin = ssh->s_rdpkt(ssh, data, datalen);
2740 ssh->protocol(ssh, NULL, 0, pktin);
2741 ssh_free_packet(pktin);
2745 static void ssh_queue_incoming_data(Ssh ssh,
2746 unsigned char **data, int *datalen)
2748 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2753 static void ssh_process_queued_incoming_data(Ssh ssh)
2756 unsigned char *data;
2759 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2760 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2764 while (!ssh->frozen && len > 0)
2765 ssh_process_incoming_data(ssh, &data, &len);
2768 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2772 static void ssh_set_frozen(Ssh ssh, int frozen)
2775 sk_set_frozen(ssh->s, frozen);
2776 ssh->frozen = frozen;
2779 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2781 /* Log raw data, if we're in that mode. */
2783 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2786 crBegin(ssh->ssh_gotdata_crstate);
2789 * To begin with, feed the characters one by one to the
2790 * protocol initialisation / selection function do_ssh_init().
2791 * When that returns 0, we're done with the initial greeting
2792 * exchange and can move on to packet discipline.
2795 int ret; /* need not be kept across crReturn */
2797 crReturnV; /* more data please */
2798 ret = do_ssh_init(ssh, *data);
2806 * We emerge from that loop when the initial negotiation is
2807 * over and we have selected an s_rdpkt function. Now pass
2808 * everything to s_rdpkt, and then pass the resulting packets
2809 * to the proper protocol handler.
2813 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2815 ssh_queue_incoming_data(ssh, &data, &datalen);
2816 /* This uses up all data and cannot cause anything interesting
2817 * to happen; indeed, for anything to happen at all, we must
2818 * return, so break out. */
2820 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2821 /* This uses up some or all data, and may freeze the
2823 ssh_process_queued_incoming_data(ssh);
2825 /* This uses up some or all data, and may freeze the
2827 ssh_process_incoming_data(ssh, &data, &datalen);
2829 /* FIXME this is probably EBW. */
2830 if (ssh->state == SSH_STATE_CLOSED)
2833 /* We're out of data. Go and get some more. */
2839 static int ssh_do_close(Ssh ssh, int notify_exit)
2842 struct ssh_channel *c;
2844 ssh->state = SSH_STATE_CLOSED;
2845 expire_timer_context(ssh);
2850 notify_remote_exit(ssh->frontend);
2855 * Now we must shut down any port- and X-forwarded channels going
2856 * through this connection.
2858 if (ssh->channels) {
2859 while (NULL != (c = index234(ssh->channels, 0))) {
2862 x11_close(c->u.x11.s);
2865 case CHAN_SOCKDATA_DORMANT:
2866 pfd_close(c->u.pfd.s);
2869 del234(ssh->channels, c); /* moving next one to index 0 */
2870 if (ssh->version == 2)
2871 bufchain_clear(&c->v.v2.outbuffer);
2876 * Go through port-forwardings, and close any associated
2877 * listening sockets.
2879 if (ssh->portfwds) {
2880 struct ssh_portfwd *pf;
2881 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2882 /* Dispose of any listening socket. */
2884 pfd_terminate(pf->local);
2885 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2888 freetree234(ssh->portfwds);
2889 ssh->portfwds = NULL;
2895 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2896 const char *error_msg, int error_code)
2898 Ssh ssh = (Ssh) plug;
2899 char addrbuf[256], *msg;
2901 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2904 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2906 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2912 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2915 Ssh ssh = (Ssh) plug;
2916 int need_notify = ssh_do_close(ssh, FALSE);
2919 if (!ssh->close_expected)
2920 error_msg = "Server unexpectedly closed network connection";
2922 error_msg = "Server closed network connection";
2925 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2929 notify_remote_exit(ssh->frontend);
2932 logevent(error_msg);
2933 if (!ssh->close_expected || !ssh->clean_exit)
2934 connection_fatal(ssh->frontend, "%s", error_msg);
2938 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2940 Ssh ssh = (Ssh) plug;
2941 ssh_gotdata(ssh, (unsigned char *)data, len);
2942 if (ssh->state == SSH_STATE_CLOSED) {
2943 ssh_do_close(ssh, TRUE);
2949 static void ssh_sent(Plug plug, int bufsize)
2951 Ssh ssh = (Ssh) plug;
2953 * If the send backlog on the SSH socket itself clears, we
2954 * should unthrottle the whole world if it was throttled.
2956 if (bufsize < SSH_MAX_BACKLOG)
2957 ssh_throttle_all(ssh, 0, bufsize);
2961 * Connect to specified host and port.
2962 * Returns an error message, or NULL on success.
2963 * Also places the canonical host name into `realhost'. It must be
2964 * freed by the caller.
2966 static const char *connect_to_host(Ssh ssh, char *host, int port,
2967 char **realhost, int nodelay, int keepalive)
2969 static const struct plug_function_table fn_table = {
2980 if (*ssh->cfg.loghost) {
2983 ssh->savedhost = dupstr(ssh->cfg.loghost);
2984 ssh->savedport = 22; /* default ssh port */
2987 * A colon suffix on savedhost also lets us affect
2990 * (FIXME: do something about IPv6 address literals here.)
2992 colon = strrchr(ssh->savedhost, ':');
2996 ssh->savedport = atoi(colon);
2999 ssh->savedhost = dupstr(host);
3001 port = 22; /* default ssh port */
3002 ssh->savedport = port;
3008 logeventf(ssh, "Looking up host \"%s\"%s", host,
3009 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3010 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3011 addr = name_lookup(host, port, realhost, &ssh->cfg,
3012 ssh->cfg.addressfamily);
3013 if ((err = sk_addr_error(addr)) != NULL) {
3017 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3022 ssh->fn = &fn_table;
3023 ssh->s = new_connection(addr, *realhost, port,
3024 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
3025 if ((err = sk_socket_error(ssh->s)) != NULL) {
3027 notify_remote_exit(ssh->frontend);
3032 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3033 * send the version string too.
3035 if (ssh->cfg.sshprot == 0)
3037 if (ssh->cfg.sshprot == 3) {
3039 ssh_send_verstring(ssh, NULL);
3043 * loghost, if configured, overrides realhost.
3045 if (*ssh->cfg.loghost) {
3047 *realhost = dupstr(ssh->cfg.loghost);
3054 * Throttle or unthrottle the SSH connection.
3056 static void ssh_throttle_conn(Ssh ssh, int adjust)
3058 int old_count = ssh->conn_throttle_count;
3059 ssh->conn_throttle_count += adjust;
3060 assert(ssh->conn_throttle_count >= 0);
3061 if (ssh->conn_throttle_count && !old_count) {
3062 ssh_set_frozen(ssh, 1);
3063 } else if (!ssh->conn_throttle_count && old_count) {
3064 ssh_set_frozen(ssh, 0);
3069 * Throttle or unthrottle _all_ local data streams (for when sends
3070 * on the SSH connection itself back up).
3072 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3075 struct ssh_channel *c;
3077 if (enable == ssh->throttled_all)
3079 ssh->throttled_all = enable;
3080 ssh->overall_bufsize = bufsize;
3083 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3085 case CHAN_MAINSESSION:
3087 * This is treated separately, outside the switch.
3091 x11_override_throttle(c->u.x11.s, enable);
3094 /* Agent channels require no buffer management. */
3097 pfd_override_throttle(c->u.pfd.s, enable);
3103 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3105 Ssh ssh = (Ssh) sshv;
3107 ssh->agent_response = reply;
3108 ssh->agent_response_len = replylen;
3110 if (ssh->version == 1)
3111 do_ssh1_login(ssh, NULL, -1, NULL);
3113 do_ssh2_authconn(ssh, NULL, -1, NULL);
3116 static void ssh_dialog_callback(void *sshv, int ret)
3118 Ssh ssh = (Ssh) sshv;
3120 ssh->user_response = ret;
3122 if (ssh->version == 1)
3123 do_ssh1_login(ssh, NULL, -1, NULL);
3125 do_ssh2_transport(ssh, NULL, -1, NULL);
3128 * This may have unfrozen the SSH connection, so do a
3131 ssh_process_queued_incoming_data(ssh);
3134 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3136 struct ssh_channel *c = (struct ssh_channel *)cv;
3138 void *sentreply = reply;
3141 /* Fake SSH_AGENT_FAILURE. */
3142 sentreply = "\0\0\0\1\5";
3145 if (ssh->version == 2) {
3146 ssh2_add_channel_data(c, sentreply, replylen);
3149 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3150 PKT_INT, c->remoteid,
3153 PKT_DATA, sentreply, replylen,
3162 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3163 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3164 * => log `wire_reason'.
3166 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3167 int code, int clean_exit)
3171 client_reason = wire_reason;
3173 error = dupprintf("Disconnected: %s", client_reason);
3175 error = dupstr("Disconnected");
3177 if (ssh->version == 1) {
3178 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3180 } else if (ssh->version == 2) {
3181 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3182 ssh2_pkt_adduint32(pktout, code);
3183 ssh2_pkt_addstring(pktout, wire_reason);
3184 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3185 ssh2_pkt_send_noqueue(ssh, pktout);
3188 ssh->close_expected = TRUE;
3189 ssh->clean_exit = clean_exit;
3190 ssh_closing((Plug)ssh, error, 0, 0);
3195 * Handle the key exchange and user authentication phases.
3197 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3198 struct Packet *pktin)
3201 unsigned char cookie[8], *ptr;
3202 struct RSAKey servkey, hostkey;
3203 struct MD5Context md5c;
3204 struct do_ssh1_login_state {
3206 unsigned char *rsabuf, *keystr1, *keystr2;
3207 unsigned long supported_ciphers_mask, supported_auths_mask;
3208 int tried_publickey, tried_agent;
3209 int tis_auth_refused, ccard_auth_refused;
3210 unsigned char session_id[16];
3213 void *publickey_blob;
3214 int publickey_bloblen;
3215 char *publickey_comment;
3216 int publickey_encrypted;
3217 prompts_t *cur_prompt;
3220 unsigned char request[5], *response, *p;
3230 crState(do_ssh1_login_state);
3232 crBegin(ssh->do_ssh1_login_crstate);
3237 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3238 bombout(("Public key packet not received"));
3242 logevent("Received public keys");
3244 ptr = ssh_pkt_getdata(pktin, 8);
3246 bombout(("SSH-1 public key packet stopped before random cookie"));
3249 memcpy(cookie, ptr, 8);
3251 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3252 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
3253 bombout(("Failed to read SSH-1 public keys from public key packet"));
3258 * Log the host key fingerprint.
3262 logevent("Host key fingerprint is:");
3263 strcpy(logmsg, " ");
3264 hostkey.comment = NULL;
3265 rsa_fingerprint(logmsg + strlen(logmsg),
3266 sizeof(logmsg) - strlen(logmsg), &hostkey);
3270 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3271 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3272 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3273 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3274 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3276 ssh->v1_local_protoflags =
3277 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3278 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3281 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3282 MD5Update(&md5c, s->keystr1, servkey.bytes);
3283 MD5Update(&md5c, cookie, 8);
3284 MD5Final(s->session_id, &md5c);
3286 for (i = 0; i < 32; i++)
3287 ssh->session_key[i] = random_byte();
3290 * Verify that the `bits' and `bytes' parameters match.
3292 if (hostkey.bits > hostkey.bytes * 8 ||
3293 servkey.bits > servkey.bytes * 8) {
3294 bombout(("SSH-1 public keys were badly formatted"));
3298 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3300 s->rsabuf = snewn(s->len, unsigned char);
3303 * Verify the host key.
3307 * First format the key into a string.
3309 int len = rsastr_len(&hostkey);
3310 char fingerprint[100];
3311 char *keystr = snewn(len, char);
3312 rsastr_fmt(keystr, &hostkey);
3313 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3315 ssh_set_frozen(ssh, 1);
3316 s->dlgret = verify_ssh_host_key(ssh->frontend,
3317 ssh->savedhost, ssh->savedport,
3318 "rsa", keystr, fingerprint,
3319 ssh_dialog_callback, ssh);
3321 if (s->dlgret < 0) {
3325 bombout(("Unexpected data from server while waiting"
3326 " for user host key response"));
3329 } while (pktin || inlen > 0);
3330 s->dlgret = ssh->user_response;
3332 ssh_set_frozen(ssh, 0);
3334 if (s->dlgret == 0) {
3335 ssh_disconnect(ssh, "User aborted at host key verification",
3341 for (i = 0; i < 32; i++) {
3342 s->rsabuf[i] = ssh->session_key[i];
3344 s->rsabuf[i] ^= s->session_id[i];
3347 if (hostkey.bytes > servkey.bytes) {
3348 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3350 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3352 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3354 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3357 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3361 logevent("Encrypted session key");
3364 int cipher_chosen = 0, warn = 0;
3365 char *cipher_string = NULL;
3367 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3368 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3369 if (next_cipher == CIPHER_WARN) {
3370 /* If/when we choose a cipher, warn about it */
3372 } else if (next_cipher == CIPHER_AES) {
3373 /* XXX Probably don't need to mention this. */
3374 logevent("AES not supported in SSH-1, skipping");
3376 switch (next_cipher) {
3377 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3378 cipher_string = "3DES"; break;
3379 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3380 cipher_string = "Blowfish"; break;
3381 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3382 cipher_string = "single-DES"; break;
3384 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3388 if (!cipher_chosen) {
3389 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3390 bombout(("Server violates SSH-1 protocol by not "
3391 "supporting 3DES encryption"));
3393 /* shouldn't happen */
3394 bombout(("No supported ciphers found"));
3398 /* Warn about chosen cipher if necessary. */
3400 ssh_set_frozen(ssh, 1);
3401 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3402 ssh_dialog_callback, ssh);
3403 if (s->dlgret < 0) {
3407 bombout(("Unexpected data from server while waiting"
3408 " for user response"));
3411 } while (pktin || inlen > 0);
3412 s->dlgret = ssh->user_response;
3414 ssh_set_frozen(ssh, 0);
3415 if (s->dlgret == 0) {
3416 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3423 switch (s->cipher_type) {
3424 case SSH_CIPHER_3DES:
3425 logevent("Using 3DES encryption");
3427 case SSH_CIPHER_DES:
3428 logevent("Using single-DES encryption");
3430 case SSH_CIPHER_BLOWFISH:
3431 logevent("Using Blowfish encryption");
3435 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3436 PKT_CHAR, s->cipher_type,
3437 PKT_DATA, cookie, 8,
3438 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3439 PKT_DATA, s->rsabuf, s->len,
3440 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3442 logevent("Trying to enable encryption...");
3446 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3447 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3449 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3450 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3451 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3453 ssh->crcda_ctx = crcda_make_context();
3454 logevent("Installing CRC compensation attack detector");
3456 if (servkey.modulus) {
3457 sfree(servkey.modulus);
3458 servkey.modulus = NULL;
3460 if (servkey.exponent) {
3461 sfree(servkey.exponent);
3462 servkey.exponent = NULL;
3464 if (hostkey.modulus) {
3465 sfree(hostkey.modulus);
3466 hostkey.modulus = NULL;
3468 if (hostkey.exponent) {
3469 sfree(hostkey.exponent);
3470 hostkey.exponent = NULL;
3474 if (pktin->type != SSH1_SMSG_SUCCESS) {
3475 bombout(("Encryption not successfully enabled"));
3479 logevent("Successfully started encryption");
3481 fflush(stdout); /* FIXME eh? */
3483 if (!get_remote_username(&ssh->cfg, s->username,
3484 sizeof(s->username))) {
3485 int ret; /* need not be kept over crReturn */
3486 s->cur_prompt = new_prompts(ssh->frontend);
3487 s->cur_prompt->to_server = TRUE;
3488 s->cur_prompt->name = dupstr("SSH login name");
3489 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3490 lenof(s->username));
3491 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3494 crWaitUntil(!pktin);
3495 ret = get_userpass_input(s->cur_prompt, in, inlen);
3500 * Failed to get a username. Terminate.
3502 free_prompts(s->cur_prompt);
3503 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3506 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3507 lenof(s->username));
3508 free_prompts(s->cur_prompt);
3511 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3513 char *userlog = dupprintf("Sent username \"%s\"", s->username);
3515 if (flags & FLAG_INTERACTIVE &&
3516 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3517 c_write_str(ssh, userlog);
3518 c_write_str(ssh, "\r\n");
3526 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3527 /* We must not attempt PK auth. Pretend we've already tried it. */
3528 s->tried_publickey = s->tried_agent = 1;
3530 s->tried_publickey = s->tried_agent = 0;
3532 s->tis_auth_refused = s->ccard_auth_refused = 0;
3534 * Load the public half of any configured keyfile for later use.
3536 if (!filename_is_null(ssh->cfg.keyfile)) {
3538 logeventf(ssh, "Reading private key file \"%.150s\"",
3539 filename_to_str(&ssh->cfg.keyfile));
3540 keytype = key_type(&ssh->cfg.keyfile);
3541 if (keytype == SSH_KEYTYPE_SSH1) {
3543 if (rsakey_pubblob(&ssh->cfg.keyfile,
3544 &s->publickey_blob, &s->publickey_bloblen,
3545 &s->publickey_comment, &error)) {
3546 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3550 logeventf(ssh, "Unable to load private key (%s)", error);
3551 msgbuf = dupprintf("Unable to load private key file "
3552 "\"%.150s\" (%s)\r\n",
3553 filename_to_str(&ssh->cfg.keyfile),
3555 c_write_str(ssh, msgbuf);
3557 s->publickey_blob = NULL;
3561 logeventf(ssh, "Unable to use this key file (%s)",
3562 key_type_to_str(keytype));
3563 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3565 filename_to_str(&ssh->cfg.keyfile),
3566 key_type_to_str(keytype));
3567 c_write_str(ssh, msgbuf);
3569 s->publickey_blob = NULL;
3572 s->publickey_blob = NULL;
3574 while (pktin->type == SSH1_SMSG_FAILURE) {
3575 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3577 if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
3579 * Attempt RSA authentication using Pageant.
3585 logevent("Pageant is running. Requesting keys.");
3587 /* Request the keys held by the agent. */
3588 PUT_32BIT(s->request, 1);
3589 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3590 if (!agent_query(s->request, 5, &r, &s->responselen,
3591 ssh_agent_callback, ssh)) {
3595 bombout(("Unexpected data from server while waiting"
3596 " for agent response"));
3599 } while (pktin || inlen > 0);
3600 r = ssh->agent_response;
3601 s->responselen = ssh->agent_response_len;
3603 s->response = (unsigned char *) r;
3604 if (s->response && s->responselen >= 5 &&
3605 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3606 s->p = s->response + 5;
3607 s->nkeys = GET_32BIT(s->p);
3609 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3610 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3611 unsigned char *pkblob = s->p;
3615 do { /* do while (0) to make breaking easy */
3616 n = ssh1_read_bignum
3617 (s->p, s->responselen-(s->p-s->response),
3622 n = ssh1_read_bignum
3623 (s->p, s->responselen-(s->p-s->response),
3628 if (s->responselen - (s->p-s->response) < 4)
3630 s->commentlen = GET_32BIT(s->p);
3632 if (s->responselen - (s->p-s->response) <
3635 s->commentp = (char *)s->p;
3636 s->p += s->commentlen;
3640 logevent("Pageant key list packet was truncated");
3644 if (s->publickey_blob) {
3645 if (!memcmp(pkblob, s->publickey_blob,
3646 s->publickey_bloblen)) {
3647 logeventf(ssh, "Pageant key #%d matches "
3648 "configured key file", s->keyi);
3649 s->tried_publickey = 1;
3651 /* Skip non-configured key */
3654 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3655 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3656 PKT_BIGNUM, s->key.modulus, PKT_END);
3658 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3659 logevent("Key refused");
3662 logevent("Received RSA challenge");
3663 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3664 bombout(("Server's RSA challenge was badly formatted"));
3669 char *agentreq, *q, *ret;
3672 len = 1 + 4; /* message type, bit count */
3673 len += ssh1_bignum_length(s->key.exponent);
3674 len += ssh1_bignum_length(s->key.modulus);
3675 len += ssh1_bignum_length(s->challenge);
3676 len += 16; /* session id */
3677 len += 4; /* response format */
3678 agentreq = snewn(4 + len, char);
3679 PUT_32BIT(agentreq, len);
3681 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3682 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3684 q += ssh1_write_bignum(q, s->key.exponent);
3685 q += ssh1_write_bignum(q, s->key.modulus);
3686 q += ssh1_write_bignum(q, s->challenge);
3687 memcpy(q, s->session_id, 16);
3689 PUT_32BIT(q, 1); /* response format */
3690 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3691 ssh_agent_callback, ssh)) {
3696 bombout(("Unexpected data from server"
3697 " while waiting for agent"
3701 } while (pktin || inlen > 0);
3702 vret = ssh->agent_response;
3703 retlen = ssh->agent_response_len;
3708 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3709 logevent("Sending Pageant's response");
3710 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3711 PKT_DATA, ret + 5, 16,
3715 if (pktin->type == SSH1_SMSG_SUCCESS) {
3717 ("Pageant's response accepted");
3718 if (flags & FLAG_VERBOSE) {
3719 c_write_str(ssh, "Authenticated using"
3721 c_write(ssh, s->commentp,
3723 c_write_str(ssh, "\" from agent\r\n");
3728 ("Pageant's response not accepted");
3731 ("Pageant failed to answer challenge");
3735 logevent("No reply received from Pageant");
3738 freebn(s->key.exponent);
3739 freebn(s->key.modulus);
3740 freebn(s->challenge);
3745 if (s->publickey_blob && !s->tried_publickey)
3746 logevent("Configured key file not in Pageant");
3751 if (s->publickey_blob && !s->tried_publickey) {
3753 * Try public key authentication with the specified
3756 int got_passphrase; /* need not be kept over crReturn */
3757 if (flags & FLAG_VERBOSE)
3758 c_write_str(ssh, "Trying public key authentication.\r\n");
3759 logeventf(ssh, "Trying public key \"%s\"",
3760 filename_to_str(&ssh->cfg.keyfile));
3761 s->tried_publickey = 1;
3762 got_passphrase = FALSE;
3763 while (!got_passphrase) {
3765 * Get a passphrase, if necessary.
3767 char *passphrase = NULL; /* only written after crReturn */
3769 if (!s->publickey_encrypted) {
3770 if (flags & FLAG_VERBOSE)
3771 c_write_str(ssh, "No passphrase required.\r\n");
3774 int ret; /* need not be kept over crReturn */
3775 s->cur_prompt = new_prompts(ssh->frontend);
3776 s->cur_prompt->to_server = FALSE;
3777 s->cur_prompt->name = dupstr("SSH key passphrase");
3778 add_prompt(s->cur_prompt,
3779 dupprintf("Passphrase for key \"%.100s\": ",
3780 s->publickey_comment),
3781 FALSE, SSH_MAX_PASSWORD_LEN);
3782 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3785 crWaitUntil(!pktin);
3786 ret = get_userpass_input(s->cur_prompt, in, inlen);
3790 /* Failed to get a passphrase. Terminate. */
3791 free_prompts(s->cur_prompt);
3792 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3796 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3797 free_prompts(s->cur_prompt);
3800 * Try decrypting key with passphrase.
3802 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3805 memset(passphrase, 0, strlen(passphrase));
3809 /* Correct passphrase. */
3810 got_passphrase = TRUE;
3811 } else if (ret == 0) {
3812 c_write_str(ssh, "Couldn't load private key from ");
3813 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3814 c_write_str(ssh, " (");
3815 c_write_str(ssh, error);
3816 c_write_str(ssh, ").\r\n");
3817 got_passphrase = FALSE;
3818 break; /* go and try something else */
3819 } else if (ret == -1) {
3820 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3821 got_passphrase = FALSE;
3824 assert(0 && "unexpected return from loadrsakey()");
3825 got_passphrase = FALSE; /* placate optimisers */
3829 if (got_passphrase) {
3832 * Send a public key attempt.
3834 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3835 PKT_BIGNUM, s->key.modulus, PKT_END);
3838 if (pktin->type == SSH1_SMSG_FAILURE) {
3839 c_write_str(ssh, "Server refused our public key.\r\n");
3840 continue; /* go and try something else */
3842 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3843 bombout(("Bizarre response to offer of public key"));
3849 unsigned char buffer[32];
3850 Bignum challenge, response;
3852 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3853 bombout(("Server's RSA challenge was badly formatted"));
3856 response = rsadecrypt(challenge, &s->key);
3857 freebn(s->key.private_exponent);/* burn the evidence */
3859 for (i = 0; i < 32; i++) {
3860 buffer[i] = bignum_byte(response, 31 - i);
3864 MD5Update(&md5c, buffer, 32);
3865 MD5Update(&md5c, s->session_id, 16);
3866 MD5Final(buffer, &md5c);
3868 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3869 PKT_DATA, buffer, 16, PKT_END);
3876 if (pktin->type == SSH1_SMSG_FAILURE) {
3877 if (flags & FLAG_VERBOSE)
3878 c_write_str(ssh, "Failed to authenticate with"
3879 " our public key.\r\n");
3880 continue; /* go and try something else */
3881 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3882 bombout(("Bizarre response to RSA authentication response"));
3886 break; /* we're through! */
3892 * Otherwise, try various forms of password-like authentication.
3894 s->cur_prompt = new_prompts(ssh->frontend);
3896 if (ssh->cfg.try_tis_auth &&
3897 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3898 !s->tis_auth_refused) {
3899 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3900 logevent("Requested TIS authentication");
3901 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3903 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3904 logevent("TIS authentication declined");
3905 if (flags & FLAG_INTERACTIVE)
3906 c_write_str(ssh, "TIS authentication refused.\r\n");
3907 s->tis_auth_refused = 1;
3912 char *instr_suf, *prompt;
3914 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3916 bombout(("TIS challenge packet was badly formed"));
3919 logevent("Received TIS challenge");
3920 s->cur_prompt->to_server = TRUE;
3921 s->cur_prompt->name = dupstr("SSH TIS authentication");
3922 /* Prompt heuristic comes from OpenSSH */
3923 if (memchr(challenge, '\n', challengelen)) {
3924 instr_suf = dupstr("");
3925 prompt = dupprintf("%.*s", challengelen, challenge);
3927 instr_suf = dupprintf("%.*s", challengelen, challenge);
3928 prompt = dupstr("Response: ");
3930 s->cur_prompt->instruction =
3931 dupprintf("Using TIS authentication.%s%s",
3932 (*instr_suf) ? "\n" : "",
3934 s->cur_prompt->instr_reqd = TRUE;
3935 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3939 if (ssh->cfg.try_tis_auth &&
3940 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3941 !s->ccard_auth_refused) {
3942 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3943 logevent("Requested CryptoCard authentication");
3944 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3946 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3947 logevent("CryptoCard authentication declined");
3948 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3949 s->ccard_auth_refused = 1;
3954 char *instr_suf, *prompt;
3956 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3958 bombout(("CryptoCard challenge packet was badly formed"));
3961 logevent("Received CryptoCard challenge");
3962 s->cur_prompt->to_server = TRUE;
3963 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3964 s->cur_prompt->name_reqd = FALSE;
3965 /* Prompt heuristic comes from OpenSSH */
3966 if (memchr(challenge, '\n', challengelen)) {
3967 instr_suf = dupstr("");
3968 prompt = dupprintf("%.*s", challengelen, challenge);
3970 instr_suf = dupprintf("%.*s", challengelen, challenge);
3971 prompt = dupstr("Response: ");
3973 s->cur_prompt->instruction =
3974 dupprintf("Using CryptoCard authentication.%s%s",
3975 (*instr_suf) ? "\n" : "",
3977 s->cur_prompt->instr_reqd = TRUE;
3978 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3982 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3983 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
3984 bombout(("No supported authentication methods available"));
3987 s->cur_prompt->to_server = TRUE;
3988 s->cur_prompt->name = dupstr("SSH password");
3989 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3990 s->username, ssh->savedhost),
3991 FALSE, SSH_MAX_PASSWORD_LEN);
3995 * Show password prompt, having first obtained it via a TIS
3996 * or CryptoCard exchange if we're doing TIS or CryptoCard
4000 int ret; /* need not be kept over crReturn */
4001 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4004 crWaitUntil(!pktin);
4005 ret = get_userpass_input(s->cur_prompt, in, inlen);
4010 * Failed to get a password (for example
4011 * because one was supplied on the command line
4012 * which has already failed to work). Terminate.
4014 free_prompts(s->cur_prompt);
4015 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4020 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4022 * Defence against traffic analysis: we send a
4023 * whole bunch of packets containing strings of
4024 * different lengths. One of these strings is the
4025 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4026 * The others are all random data in
4027 * SSH1_MSG_IGNORE packets. This way a passive
4028 * listener can't tell which is the password, and
4029 * hence can't deduce the password length.
4031 * Anybody with a password length greater than 16
4032 * bytes is going to have enough entropy in their
4033 * password that a listener won't find it _that_
4034 * much help to know how long it is. So what we'll
4037 * - if password length < 16, we send 15 packets
4038 * containing string lengths 1 through 15
4040 * - otherwise, we let N be the nearest multiple
4041 * of 8 below the password length, and send 8
4042 * packets containing string lengths N through
4043 * N+7. This won't obscure the order of
4044 * magnitude of the password length, but it will
4045 * introduce a bit of extra uncertainty.
4047 * A few servers can't deal with SSH1_MSG_IGNORE, at
4048 * least in this context. For these servers, we need
4049 * an alternative defence. We make use of the fact
4050 * that the password is interpreted as a C string:
4051 * so we can append a NUL, then some random data.
4053 * A few servers can deal with neither SSH1_MSG_IGNORE
4054 * here _nor_ a padded password string.
4055 * For these servers we are left with no defences
4056 * against password length sniffing.
4058 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4059 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4061 * The server can deal with SSH1_MSG_IGNORE, so
4062 * we can use the primary defence.
4064 int bottom, top, pwlen, i;
4067 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4069 bottom = 0; /* zero length passwords are OK! :-) */
4072 bottom = pwlen & ~7;
4076 assert(pwlen >= bottom && pwlen <= top);
4078 randomstr = snewn(top + 1, char);
4080 for (i = bottom; i <= top; i++) {
4082 defer_packet(ssh, s->pwpkt_type,
4083 PKTT_PASSWORD, PKT_STR,
4084 s->cur_prompt->prompts[0]->result,
4085 PKTT_OTHER, PKT_END);
4087 for (j = 0; j < i; j++) {
4089 randomstr[j] = random_byte();
4090 } while (randomstr[j] == '\0');
4092 randomstr[i] = '\0';
4093 defer_packet(ssh, SSH1_MSG_IGNORE,
4094 PKT_STR, randomstr, PKT_END);
4097 logevent("Sending password with camouflage packets");
4098 ssh_pkt_defersend(ssh);
4101 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4103 * The server can't deal with SSH1_MSG_IGNORE
4104 * but can deal with padded passwords, so we
4105 * can use the secondary defence.
4111 len = strlen(s->cur_prompt->prompts[0]->result);
4112 if (len < sizeof(string)) {
4114 strcpy(string, s->cur_prompt->prompts[0]->result);
4115 len++; /* cover the zero byte */
4116 while (len < sizeof(string)) {
4117 string[len++] = (char) random_byte();
4120 ss = s->cur_prompt->prompts[0]->result;
4122 logevent("Sending length-padded password");
4123 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4124 PKT_INT, len, PKT_DATA, ss, len,
4125 PKTT_OTHER, PKT_END);
4128 * The server is believed unable to cope with
4129 * any of our password camouflage methods.
4132 len = strlen(s->cur_prompt->prompts[0]->result);
4133 logevent("Sending unpadded password");
4134 send_packet(ssh, s->pwpkt_type,
4135 PKTT_PASSWORD, PKT_INT, len,
4136 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4137 PKTT_OTHER, PKT_END);
4140 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4141 PKT_STR, s->cur_prompt->prompts[0]->result,
4142 PKTT_OTHER, PKT_END);
4144 logevent("Sent password");
4145 free_prompts(s->cur_prompt);
4147 if (pktin->type == SSH1_SMSG_FAILURE) {
4148 if (flags & FLAG_VERBOSE)
4149 c_write_str(ssh, "Access denied\r\n");
4150 logevent("Authentication refused");
4151 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4152 bombout(("Strange packet received, type %d", pktin->type));
4158 if (s->publickey_blob) {
4159 sfree(s->publickey_blob);
4160 sfree(s->publickey_comment);
4163 logevent("Authentication successful");
4168 void sshfwd_close(struct ssh_channel *c)
4172 if (ssh->state == SSH_STATE_CLOSED)
4177 * If halfopen is true, we have sent
4178 * CHANNEL_OPEN for this channel, but it hasn't even been
4179 * acknowledged by the server. So we must set a close flag
4180 * on it now, and then when the server acks the channel
4181 * open, we can close it then.
4184 if (ssh->version == 1) {
4185 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4187 c->closes = 1; /* sent MSG_CLOSE */
4189 int bytes_to_send = bufchain_size(&c->v.v2.outbuffer);
4190 if (bytes_to_send > 0) {
4192 * If we still have unsent data in our outgoing
4193 * buffer for this channel, we can't actually
4194 * initiate a close operation yet or that data
4195 * will be lost. Instead, set the pending_close
4196 * flag so that when we do clear the buffer
4197 * we'll start closing the channel.
4199 char logmsg[160] = {'\0'};
4202 "Forwarded port pending to be closed : "
4203 "%d bytes remaining",
4207 c->pending_close = TRUE;
4210 * No locally buffered data, so we can send the
4211 * close message immediately.
4213 struct Packet *pktout;
4214 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4215 ssh2_pkt_adduint32(pktout, c->remoteid);
4216 ssh2_pkt_send(ssh, pktout);
4217 c->closes = 1; /* sent MSG_CLOSE */
4218 logevent("Nothing left to send, closing channel");
4223 if (c->type == CHAN_X11) {
4225 logevent("Forwarded X11 connection terminated");
4226 } else if (c->type == CHAN_SOCKDATA ||
4227 c->type == CHAN_SOCKDATA_DORMANT) {
4229 logevent("Forwarded port closed");
4234 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4238 if (ssh->state == SSH_STATE_CLOSED)
4241 if (ssh->version == 1) {
4242 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4243 PKT_INT, c->remoteid,
4244 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
4245 PKTT_OTHER, PKT_END);
4247 * In SSH-1 we can return 0 here - implying that forwarded
4248 * connections are never individually throttled - because
4249 * the only circumstance that can cause throttling will be
4250 * the whole SSH connection backing up, in which case
4251 * _everything_ will be throttled as a whole.
4255 ssh2_add_channel_data(c, buf, len);
4256 return ssh2_try_send(c);
4260 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4265 if (ssh->state == SSH_STATE_CLOSED)
4268 if (ssh->version == 1) {
4269 buflimit = SSH1_BUFFER_LIMIT;
4271 buflimit = c->v.v2.locmaxwin;
4272 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4274 if (c->throttling_conn && bufsize <= buflimit) {
4275 c->throttling_conn = 0;
4276 ssh_throttle_conn(ssh, -1);
4280 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4282 struct queued_handler *qh = ssh->qhead;
4286 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4289 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4290 ssh->packet_dispatch[qh->msg1] = NULL;
4293 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4294 ssh->packet_dispatch[qh->msg2] = NULL;
4298 ssh->qhead = qh->next;
4300 if (ssh->qhead->msg1 > 0) {
4301 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4302 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4304 if (ssh->qhead->msg2 > 0) {
4305 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4306 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4309 ssh->qhead = ssh->qtail = NULL;
4310 ssh->packet_dispatch[pktin->type] = NULL;
4313 qh->handler(ssh, pktin, qh->ctx);
4318 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4319 chandler_fn_t handler, void *ctx)
4321 struct queued_handler *qh;
4323 qh = snew(struct queued_handler);
4326 qh->handler = handler;
4330 if (ssh->qtail == NULL) {
4334 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4335 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4338 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4339 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4342 ssh->qtail->next = qh;
4347 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4349 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4351 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4352 SSH2_MSG_REQUEST_SUCCESS)) {
4353 logeventf(ssh, "Remote port forwarding from %s enabled",
4356 logeventf(ssh, "Remote port forwarding from %s refused",
4359 rpf = del234(ssh->rportfwds, pf);
4361 pf->pfrec->remote = NULL;
4366 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
4368 const char *portfwd_strptr = cfg->portfwd;
4369 struct ssh_portfwd *epf;
4372 if (!ssh->portfwds) {
4373 ssh->portfwds = newtree234(ssh_portcmp);
4376 * Go through the existing port forwardings and tag them
4377 * with status==DESTROY. Any that we want to keep will be
4378 * re-enabled (status==KEEP) as we go through the
4379 * configuration and find out which bits are the same as
4382 struct ssh_portfwd *epf;
4384 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4385 epf->status = DESTROY;
4388 while (*portfwd_strptr) {
4389 char address_family, type;
4390 int sport,dport,sserv,dserv;
4391 char sports[256], dports[256], saddr[256], host[256];
4394 address_family = 'A';
4396 if (*portfwd_strptr == 'A' ||
4397 *portfwd_strptr == '4' ||
4398 *portfwd_strptr == '6')
4399 address_family = *portfwd_strptr++;
4400 if (*portfwd_strptr == 'L' ||
4401 *portfwd_strptr == 'R' ||
4402 *portfwd_strptr == 'D')
4403 type = *portfwd_strptr++;
4408 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4409 if (*portfwd_strptr == ':') {
4411 * We've seen a colon in the middle of the
4412 * source port number. This means that
4413 * everything we've seen until now is the
4414 * source _address_, so we'll move it into
4415 * saddr and start sports from the beginning
4420 if (ssh->version == 1 && type == 'R') {
4421 logeventf(ssh, "SSH-1 cannot handle remote source address "
4422 "spec \"%s\"; ignoring", sports);
4424 strcpy(saddr, sports);
4427 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4431 if (*portfwd_strptr == '\t')
4434 while (*portfwd_strptr && *portfwd_strptr != ':') {
4435 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4438 if (*portfwd_strptr == ':')
4441 while (*portfwd_strptr) {
4442 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4446 dport = atoi(dports);
4450 dport = net_service_lookup(dports);
4452 logeventf(ssh, "Service lookup failed for destination"
4453 " port \"%s\"", dports);
4457 while (*portfwd_strptr) portfwd_strptr++;
4461 portfwd_strptr++; /* eat the NUL and move to next one */
4463 sport = atoi(sports);
4467 sport = net_service_lookup(sports);
4469 logeventf(ssh, "Service lookup failed for source"
4470 " port \"%s\"", sports);
4473 if (sport && dport) {
4474 /* Set up a description of the source port. */
4475 struct ssh_portfwd *pfrec, *epfrec;
4477 pfrec = snew(struct ssh_portfwd);
4479 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4480 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4481 pfrec->sport = sport;
4482 pfrec->daddr = *host ? dupstr(host) : NULL;
4483 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4484 pfrec->dport = dport;
4485 pfrec->local = NULL;
4486 pfrec->remote = NULL;
4487 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4488 address_family == '6' ? ADDRTYPE_IPV6 :
4491 epfrec = add234(ssh->portfwds, pfrec);
4492 if (epfrec != pfrec) {
4493 if (epfrec->status == DESTROY) {
4495 * We already have a port forwarding up and running
4496 * with precisely these parameters. Hence, no need
4497 * to do anything; simply re-tag the existing one
4500 epfrec->status = KEEP;
4503 * Anything else indicates that there was a duplicate
4504 * in our input, which we'll silently ignore.
4506 free_portfwd(pfrec);
4508 pfrec->status = CREATE;
4514 * Now go through and destroy any port forwardings which were
4517 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4518 if (epf->status == DESTROY) {
4521 message = dupprintf("%s port forwarding from %s%s%d",
4522 epf->type == 'L' ? "local" :
4523 epf->type == 'R' ? "remote" : "dynamic",
4524 epf->saddr ? epf->saddr : "",
4525 epf->saddr ? ":" : "",
4528 if (epf->type != 'D') {
4529 char *msg2 = dupprintf("%s to %s:%d", message,
4530 epf->daddr, epf->dport);
4535 logeventf(ssh, "Cancelling %s", message);
4538 /* epf->remote or epf->local may be NULL if setting up a
4539 * forwarding failed. */
4541 struct ssh_rportfwd *rpf = epf->remote;
4542 struct Packet *pktout;
4545 * Cancel the port forwarding at the server
4548 if (ssh->version == 1) {
4550 * We cannot cancel listening ports on the
4551 * server side in SSH-1! There's no message
4552 * to support it. Instead, we simply remove
4553 * the rportfwd record from the local end
4554 * so that any connections the server tries
4555 * to make on it are rejected.
4558 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4559 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4560 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4562 ssh2_pkt_addstring(pktout, epf->saddr);
4563 } else if (ssh->cfg.rport_acceptall) {
4564 /* XXX: ssh->cfg.rport_acceptall may not represent
4565 * what was used to open the original connection,
4566 * since it's reconfigurable. */
4567 ssh2_pkt_addstring(pktout, "0.0.0.0");
4569 ssh2_pkt_addstring(pktout, "127.0.0.1");
4571 ssh2_pkt_adduint32(pktout, epf->sport);
4572 ssh2_pkt_send(ssh, pktout);
4575 del234(ssh->rportfwds, rpf);
4577 } else if (epf->local) {
4578 pfd_terminate(epf->local);
4581 delpos234(ssh->portfwds, i);
4583 i--; /* so we don't skip one in the list */
4587 * And finally, set up any new port forwardings (status==CREATE).
4589 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4590 if (epf->status == CREATE) {
4591 char *sportdesc, *dportdesc;
4592 sportdesc = dupprintf("%s%s%s%s%d%s",
4593 epf->saddr ? epf->saddr : "",
4594 epf->saddr ? ":" : "",
4595 epf->sserv ? epf->sserv : "",
4596 epf->sserv ? "(" : "",
4598 epf->sserv ? ")" : "");
4599 if (epf->type == 'D') {
4602 dportdesc = dupprintf("%s:%s%s%d%s",
4604 epf->dserv ? epf->dserv : "",
4605 epf->dserv ? "(" : "",
4607 epf->dserv ? ")" : "");
4610 if (epf->type == 'L') {
4611 const char *err = pfd_addforward(epf->daddr, epf->dport,
4612 epf->saddr, epf->sport,
4615 epf->addressfamily);
4617 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4618 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4619 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4620 sportdesc, dportdesc,
4621 err ? " failed: " : "", err ? err : "");
4622 } else if (epf->type == 'D') {
4623 const char *err = pfd_addforward(NULL, -1,
4624 epf->saddr, epf->sport,
4627 epf->addressfamily);
4629 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4630 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4631 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4633 err ? " failed: " : "", err ? err : "");
4635 struct ssh_rportfwd *pf;
4638 * Ensure the remote port forwardings tree exists.
4640 if (!ssh->rportfwds) {
4641 if (ssh->version == 1)
4642 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4644 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4647 pf = snew(struct ssh_rportfwd);
4648 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4649 pf->dhost[lenof(pf->dhost)-1] = '\0';
4650 pf->dport = epf->dport;
4651 pf->sport = epf->sport;
4652 if (add234(ssh->rportfwds, pf) != pf) {
4653 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4654 epf->daddr, epf->dport);
4657 logeventf(ssh, "Requesting remote port %s"
4658 " forward to %s", sportdesc, dportdesc);
4660 pf->sportdesc = sportdesc;
4665 if (ssh->version == 1) {
4666 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4667 PKT_INT, epf->sport,
4668 PKT_STR, epf->daddr,
4669 PKT_INT, epf->dport,
4671 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4673 ssh_rportfwd_succfail, pf);
4675 struct Packet *pktout;
4676 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4677 ssh2_pkt_addstring(pktout, "tcpip-forward");
4678 ssh2_pkt_addbool(pktout, 1);/* want reply */
4680 ssh2_pkt_addstring(pktout, epf->saddr);
4681 } else if (cfg->rport_acceptall) {
4682 ssh2_pkt_addstring(pktout, "0.0.0.0");
4684 ssh2_pkt_addstring(pktout, "127.0.0.1");
4686 ssh2_pkt_adduint32(pktout, epf->sport);
4687 ssh2_pkt_send(ssh, pktout);
4689 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4690 SSH2_MSG_REQUEST_FAILURE,
4691 ssh_rportfwd_succfail, pf);
4700 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4703 int stringlen, bufsize;
4705 ssh_pkt_getstring(pktin, &string, &stringlen);
4706 if (string == NULL) {
4707 bombout(("Incoming terminal data packet was badly formed"));
4711 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4713 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4714 ssh->v1_stdout_throttling = 1;
4715 ssh_throttle_conn(ssh, +1);
4719 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4721 /* Remote side is trying to open a channel to talk to our
4722 * X-Server. Give them back a local channel number. */
4723 struct ssh_channel *c;
4724 int remoteid = ssh_pkt_getuint32(pktin);
4726 logevent("Received X11 connect request");
4727 /* Refuse if X11 forwarding is disabled. */
4728 if (!ssh->X11_fwd_enabled) {
4729 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4730 PKT_INT, remoteid, PKT_END);
4731 logevent("Rejected X11 connect request");
4733 c = snew(struct ssh_channel);
4736 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4737 NULL, -1, &ssh->cfg) != NULL) {
4738 logevent("Opening X11 forward connection failed");
4740 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4741 PKT_INT, remoteid, PKT_END);
4744 ("Opening X11 forward connection succeeded");
4745 c->remoteid = remoteid;
4746 c->halfopen = FALSE;
4747 c->localid = alloc_channel_id(ssh);
4749 c->pending_close = FALSE;
4750 c->throttling_conn = 0;
4751 c->type = CHAN_X11; /* identify channel type */
4752 add234(ssh->channels, c);
4753 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4754 PKT_INT, c->remoteid, PKT_INT,
4755 c->localid, PKT_END);
4756 logevent("Opened X11 forward channel");
4761 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4763 /* Remote side is trying to open a channel to talk to our
4764 * agent. Give them back a local channel number. */
4765 struct ssh_channel *c;
4766 int remoteid = ssh_pkt_getuint32(pktin);
4768 /* Refuse if agent forwarding is disabled. */
4769 if (!ssh->agentfwd_enabled) {
4770 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4771 PKT_INT, remoteid, PKT_END);
4773 c = snew(struct ssh_channel);
4775 c->remoteid = remoteid;
4776 c->halfopen = FALSE;
4777 c->localid = alloc_channel_id(ssh);
4779 c->pending_close = FALSE;
4780 c->throttling_conn = 0;
4781 c->type = CHAN_AGENT; /* identify channel type */
4782 c->u.a.lensofar = 0;
4783 add234(ssh->channels, c);
4784 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4785 PKT_INT, c->remoteid, PKT_INT, c->localid,
4790 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4792 /* Remote side is trying to open a channel to talk to a
4793 * forwarded port. Give them back a local channel number. */
4794 struct ssh_channel *c;
4795 struct ssh_rportfwd pf, *pfp;
4800 c = snew(struct ssh_channel);
4803 remoteid = ssh_pkt_getuint32(pktin);
4804 ssh_pkt_getstring(pktin, &host, &hostsize);
4805 port = ssh_pkt_getuint32(pktin);
4807 if (hostsize >= lenof(pf.dhost))
4808 hostsize = lenof(pf.dhost)-1;
4809 memcpy(pf.dhost, host, hostsize);
4810 pf.dhost[hostsize] = '\0';
4812 pfp = find234(ssh->rportfwds, &pf, NULL);
4815 logeventf(ssh, "Rejected remote port open request for %s:%d",
4817 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4818 PKT_INT, remoteid, PKT_END);
4820 logeventf(ssh, "Received remote port open request for %s:%d",
4822 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4823 c, &ssh->cfg, pfp->pfrec->addressfamily);
4825 logeventf(ssh, "Port open failed: %s", e);
4827 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4828 PKT_INT, remoteid, PKT_END);
4830 c->remoteid = remoteid;
4831 c->halfopen = FALSE;
4832 c->localid = alloc_channel_id(ssh);
4834 c->pending_close = FALSE;
4835 c->throttling_conn = 0;
4836 c->type = CHAN_SOCKDATA; /* identify channel type */
4837 add234(ssh->channels, c);
4838 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4839 PKT_INT, c->remoteid, PKT_INT,
4840 c->localid, PKT_END);
4841 logevent("Forwarded port opened successfully");
4846 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4848 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4849 unsigned int localid = ssh_pkt_getuint32(pktin);
4850 struct ssh_channel *c;
4852 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4853 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4854 c->remoteid = localid;
4855 c->halfopen = FALSE;
4856 c->type = CHAN_SOCKDATA;
4857 c->throttling_conn = 0;
4858 pfd_confirm(c->u.pfd.s);
4861 if (c && c->closes) {
4863 * We have a pending close on this channel,
4864 * which we decided on before the server acked
4865 * the channel open. So now we know the
4866 * remoteid, we can close it again.
4868 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4869 PKT_INT, c->remoteid, PKT_END);
4873 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4875 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4876 struct ssh_channel *c;
4878 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4879 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4880 logevent("Forwarded connection refused by server");
4881 pfd_close(c->u.pfd.s);
4882 del234(ssh->channels, c);
4887 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4889 /* Remote side closes a channel. */
4890 unsigned i = ssh_pkt_getuint32(pktin);
4891 struct ssh_channel *c;
4892 c = find234(ssh->channels, &i, ssh_channelfind);
4893 if (c && !c->halfopen) {
4896 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4898 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4899 logevent("Forwarded X11 connection terminated");
4900 assert(c->u.x11.s != NULL);
4901 x11_close(c->u.x11.s);
4904 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4905 logevent("Forwarded port closed");
4906 assert(c->u.pfd.s != NULL);
4907 pfd_close(c->u.pfd.s);
4911 c->closes |= (closetype << 2); /* seen this message */
4912 if (!(c->closes & closetype)) {
4913 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4915 c->closes |= closetype; /* sent it too */
4918 if (c->closes == 15) {
4919 del234(ssh->channels, c);
4923 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4924 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4925 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4930 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4932 /* Data sent down one of our channels. */
4933 int i = ssh_pkt_getuint32(pktin);
4936 struct ssh_channel *c;
4938 ssh_pkt_getstring(pktin, &p, &len);
4940 c = find234(ssh->channels, &i, ssh_channelfind);
4945 bufsize = x11_send(c->u.x11.s, p, len);
4948 bufsize = pfd_send(c->u.pfd.s, p, len);
4951 /* Data for an agent message. Buffer it. */
4953 if (c->u.a.lensofar < 4) {
4954 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
4955 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4959 c->u.a.lensofar += l;
4961 if (c->u.a.lensofar == 4) {
4963 4 + GET_32BIT(c->u.a.msglen);
4964 c->u.a.message = snewn(c->u.a.totallen,
4966 memcpy(c->u.a.message, c->u.a.msglen, 4);
4968 if (c->u.a.lensofar >= 4 && len > 0) {
4970 min(c->u.a.totallen - c->u.a.lensofar,
4972 memcpy(c->u.a.message + c->u.a.lensofar, p,
4976 c->u.a.lensofar += l;
4978 if (c->u.a.lensofar == c->u.a.totallen) {
4981 if (agent_query(c->u.a.message,
4984 ssh_agentf_callback, c))
4985 ssh_agentf_callback(c, reply, replylen);
4986 sfree(c->u.a.message);
4987 c->u.a.lensofar = 0;
4990 bufsize = 0; /* agent channels never back up */
4993 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
4994 c->throttling_conn = 1;
4995 ssh_throttle_conn(ssh, +1);
5000 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5002 ssh->exitcode = ssh_pkt_getuint32(pktin);
5003 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5004 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5006 * In case `helpful' firewalls or proxies tack
5007 * extra human-readable text on the end of the
5008 * session which we might mistake for another
5009 * encrypted packet, we close the session once
5010 * we've sent EXIT_CONFIRMATION.
5012 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5015 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5016 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5018 struct Packet *pktout = (struct Packet *)data;
5020 unsigned int arg = 0;
5021 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5022 if (i == lenof(ssh_ttymodes)) return;
5023 switch (ssh_ttymodes[i].type) {
5025 arg = ssh_tty_parse_specchar(val);
5028 arg = ssh_tty_parse_boolean(val);
5031 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5032 ssh2_pkt_addbyte(pktout, arg);
5036 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5037 struct Packet *pktin)
5039 crBegin(ssh->do_ssh1_connection_crstate);
5041 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5042 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5043 ssh1_smsg_stdout_stderr_data;
5045 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5046 ssh1_msg_channel_open_confirmation;
5047 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5048 ssh1_msg_channel_open_failure;
5049 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5050 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5051 ssh1_msg_channel_close;
5052 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5053 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5055 if (ssh->cfg.agentfwd && agent_exists()) {
5056 logevent("Requesting agent forwarding");
5057 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5061 if (pktin->type != SSH1_SMSG_SUCCESS
5062 && pktin->type != SSH1_SMSG_FAILURE) {
5063 bombout(("Protocol confusion"));
5065 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5066 logevent("Agent forwarding refused");
5068 logevent("Agent forwarding enabled");
5069 ssh->agentfwd_enabled = TRUE;
5070 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5074 if (ssh->cfg.x11_forward &&
5075 (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
5076 ssh->cfg.x11_auth, &ssh->cfg))) {
5077 logevent("Requesting X11 forwarding");
5079 * Note that while we blank the X authentication data here, we don't
5080 * take any special action to blank the start of an X11 channel,
5081 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5082 * without having session blanking enabled is likely to leak your
5083 * cookie into the log.
5085 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5086 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5087 PKT_STR, ssh->x11disp->remoteauthprotoname,
5089 PKT_STR, ssh->x11disp->remoteauthdatastring,
5091 PKT_INT, ssh->x11disp->screennum,
5094 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5095 PKT_STR, ssh->x11disp->remoteauthprotoname,
5097 PKT_STR, ssh->x11disp->remoteauthdatastring,
5104 if (pktin->type != SSH1_SMSG_SUCCESS
5105 && pktin->type != SSH1_SMSG_FAILURE) {
5106 bombout(("Protocol confusion"));
5108 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5109 logevent("X11 forwarding refused");
5111 logevent("X11 forwarding enabled");
5112 ssh->X11_fwd_enabled = TRUE;
5113 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5117 ssh_setup_portfwd(ssh, &ssh->cfg);
5118 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5120 if (!ssh->cfg.nopty) {
5122 /* Unpick the terminal-speed string. */
5123 /* XXX perhaps we should allow no speeds to be sent. */
5124 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5125 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
5126 /* Send the pty request. */
5127 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5128 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
5129 ssh_pkt_adduint32(pkt, ssh->term_height);
5130 ssh_pkt_adduint32(pkt, ssh->term_width);
5131 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5132 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5133 parse_ttymodes(ssh, ssh->cfg.ttymodes,
5134 ssh1_send_ttymode, (void *)pkt);
5135 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5136 ssh_pkt_adduint32(pkt, ssh->ispeed);
5137 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5138 ssh_pkt_adduint32(pkt, ssh->ospeed);
5139 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5141 ssh->state = SSH_STATE_INTERMED;
5145 if (pktin->type != SSH1_SMSG_SUCCESS
5146 && pktin->type != SSH1_SMSG_FAILURE) {
5147 bombout(("Protocol confusion"));
5149 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5150 c_write_str(ssh, "Server refused to allocate pty\r\n");
5151 ssh->editing = ssh->echoing = 1;
5153 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5154 ssh->ospeed, ssh->ispeed);
5156 ssh->editing = ssh->echoing = 1;
5159 if (ssh->cfg.compression) {
5160 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5164 if (pktin->type != SSH1_SMSG_SUCCESS
5165 && pktin->type != SSH1_SMSG_FAILURE) {
5166 bombout(("Protocol confusion"));
5168 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5169 c_write_str(ssh, "Server refused to compress\r\n");
5171 logevent("Started compression");
5172 ssh->v1_compressing = TRUE;
5173 ssh->cs_comp_ctx = zlib_compress_init();
5174 logevent("Initialised zlib (RFC1950) compression");
5175 ssh->sc_comp_ctx = zlib_decompress_init();
5176 logevent("Initialised zlib (RFC1950) decompression");
5180 * Start the shell or command.
5182 * Special case: if the first-choice command is an SSH-2
5183 * subsystem (hence not usable here) and the second choice
5184 * exists, we fall straight back to that.
5187 char *cmd = ssh->cfg.remote_cmd_ptr;
5189 if (!cmd) cmd = ssh->cfg.remote_cmd;
5191 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
5192 cmd = ssh->cfg.remote_cmd_ptr2;
5193 ssh->fallback_cmd = TRUE;
5196 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5198 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5199 logevent("Started session");
5202 ssh->state = SSH_STATE_SESSION;
5203 if (ssh->size_needed)
5204 ssh_size(ssh, ssh->term_width, ssh->term_height);
5205 if (ssh->eof_needed)
5206 ssh_special(ssh, TS_EOF);
5209 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5211 ssh->channels = newtree234(ssh_channelcmp);
5215 * By this point, most incoming packets are already being
5216 * handled by the dispatch table, and we need only pay
5217 * attention to the unusual ones.
5222 if (pktin->type == SSH1_SMSG_SUCCESS) {
5223 /* may be from EXEC_SHELL on some servers */
5224 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5225 /* may be from EXEC_SHELL on some servers
5226 * if no pty is available or in other odd cases. Ignore */
5228 bombout(("Strange packet received: type %d", pktin->type));
5233 int len = min(inlen, 512);
5234 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5235 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
5236 PKTT_OTHER, PKT_END);
5247 * Handle the top-level SSH-2 protocol.
5249 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5254 ssh_pkt_getstring(pktin, &msg, &msglen);
5255 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5258 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5260 /* log reason code in disconnect message */
5264 ssh_pkt_getstring(pktin, &msg, &msglen);
5265 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5268 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5270 /* Do nothing, because we're ignoring it! Duhh. */
5273 static void ssh1_protocol_setup(Ssh ssh)
5278 * Most messages are handled by the coroutines.
5280 for (i = 0; i < 256; i++)
5281 ssh->packet_dispatch[i] = NULL;
5284 * These special message types we install handlers for.
5286 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5287 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5288 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5291 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5292 struct Packet *pktin)
5294 unsigned char *in=(unsigned char*)vin;
5295 if (ssh->state == SSH_STATE_CLOSED)
5298 if (pktin && ssh->packet_dispatch[pktin->type]) {
5299 ssh->packet_dispatch[pktin->type](ssh, pktin);
5303 if (!ssh->protocol_initial_phase_done) {
5304 if (do_ssh1_login(ssh, in, inlen, pktin))
5305 ssh->protocol_initial_phase_done = TRUE;
5310 do_ssh1_connection(ssh, in, inlen, pktin);
5314 * Utility routine for decoding comma-separated strings in KEXINIT.
5316 static int in_commasep_string(char *needle, char *haystack, int haylen)
5319 if (!needle || !haystack) /* protect against null pointers */
5321 needlen = strlen(needle);
5324 * Is it at the start of the string?
5326 if (haylen >= needlen && /* haystack is long enough */
5327 !memcmp(needle, haystack, needlen) && /* initial match */
5328 (haylen == needlen || haystack[needlen] == ',')
5329 /* either , or EOS follows */
5333 * If not, search for the next comma and resume after that.
5334 * If no comma found, terminate.
5336 while (haylen > 0 && *haystack != ',')
5337 haylen--, haystack++;
5340 haylen--, haystack++; /* skip over comma itself */
5345 * Similar routine for checking whether we have the first string in a list.
5347 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5350 if (!needle || !haystack) /* protect against null pointers */
5352 needlen = strlen(needle);
5354 * Is it at the start of the string?
5356 if (haylen >= needlen && /* haystack is long enough */
5357 !memcmp(needle, haystack, needlen) && /* initial match */
5358 (haylen == needlen || haystack[needlen] == ',')
5359 /* either , or EOS follows */
5367 * SSH-2 key creation method.
5368 * (Currently assumes 2 lots of any hash are sufficient to generate
5369 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5371 #define SSH2_MKKEY_ITERS (2)
5372 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5373 unsigned char *keyspace)
5375 const struct ssh_hash *h = ssh->kex->hash;
5377 /* First hlen bytes. */
5379 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5380 hash_mpint(h, s, K);
5381 h->bytes(s, H, h->hlen);
5382 h->bytes(s, &chr, 1);
5383 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5384 h->final(s, keyspace);
5385 /* Next hlen bytes. */
5387 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5388 hash_mpint(h, s, K);
5389 h->bytes(s, H, h->hlen);
5390 h->bytes(s, keyspace, h->hlen);
5391 h->final(s, keyspace + h->hlen);
5395 * Handle the SSH-2 transport layer.
5397 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5398 struct Packet *pktin)
5400 unsigned char *in = (unsigned char *)vin;
5401 struct do_ssh2_transport_state {
5402 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5403 Bignum p, g, e, f, K;
5406 int kex_init_value, kex_reply_value;
5407 const struct ssh_mac **maclist;
5409 const struct ssh2_cipher *cscipher_tobe;
5410 const struct ssh2_cipher *sccipher_tobe;
5411 const struct ssh_mac *csmac_tobe;
5412 const struct ssh_mac *scmac_tobe;
5413 const struct ssh_compress *cscomp_tobe;
5414 const struct ssh_compress *sccomp_tobe;
5415 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5416 int hostkeylen, siglen, rsakeylen;
5417 void *hkey; /* actual host key */
5418 void *rsakey; /* for RSA kex */
5419 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5420 int n_preferred_kex;
5421 const struct ssh_kexes *preferred_kex[KEX_MAX];
5422 int n_preferred_ciphers;
5423 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5424 const struct ssh_compress *preferred_comp;
5425 int userauth_succeeded; /* for delayed compression */
5426 int pending_compression;
5427 int got_session_id, activated_authconn;
5428 struct Packet *pktout;
5433 crState(do_ssh2_transport_state);
5435 crBegin(ssh->do_ssh2_transport_crstate);
5437 s->cscipher_tobe = s->sccipher_tobe = NULL;
5438 s->csmac_tobe = s->scmac_tobe = NULL;
5439 s->cscomp_tobe = s->sccomp_tobe = NULL;
5441 s->got_session_id = s->activated_authconn = FALSE;
5442 s->userauth_succeeded = FALSE;
5443 s->pending_compression = FALSE;
5446 * Be prepared to work around the buggy MAC problem.
5448 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5449 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5451 s->maclist = macs, s->nmacs = lenof(macs);
5454 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5456 int i, j, commalist_started;
5459 * Set up the preferred key exchange. (NULL => warn below here)
5461 s->n_preferred_kex = 0;
5462 for (i = 0; i < KEX_MAX; i++) {
5463 switch (ssh->cfg.ssh_kexlist[i]) {
5465 s->preferred_kex[s->n_preferred_kex++] =
5466 &ssh_diffiehellman_gex;
5469 s->preferred_kex[s->n_preferred_kex++] =
5470 &ssh_diffiehellman_group14;
5473 s->preferred_kex[s->n_preferred_kex++] =
5474 &ssh_diffiehellman_group1;
5477 s->preferred_kex[s->n_preferred_kex++] =
5481 /* Flag for later. Don't bother if it's the last in
5483 if (i < KEX_MAX - 1) {
5484 s->preferred_kex[s->n_preferred_kex++] = NULL;
5491 * Set up the preferred ciphers. (NULL => warn below here)
5493 s->n_preferred_ciphers = 0;
5494 for (i = 0; i < CIPHER_MAX; i++) {
5495 switch (ssh->cfg.ssh_cipherlist[i]) {
5496 case CIPHER_BLOWFISH:
5497 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5500 if (ssh->cfg.ssh2_des_cbc) {
5501 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5505 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5508 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5510 case CIPHER_ARCFOUR:
5511 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5514 /* Flag for later. Don't bother if it's the last in
5516 if (i < CIPHER_MAX - 1) {
5517 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5524 * Set up preferred compression.
5526 if (ssh->cfg.compression)
5527 s->preferred_comp = &ssh_zlib;
5529 s->preferred_comp = &ssh_comp_none;
5532 * Enable queueing of outgoing auth- or connection-layer
5533 * packets while we are in the middle of a key exchange.
5535 ssh->queueing = TRUE;
5538 * Flag that KEX is in progress.
5540 ssh->kex_in_progress = TRUE;
5543 * Construct and send our key exchange packet.
5545 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5546 for (i = 0; i < 16; i++)
5547 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5548 /* List key exchange algorithms. */
5549 ssh2_pkt_addstring_start(s->pktout);
5550 commalist_started = 0;
5551 for (i = 0; i < s->n_preferred_kex; i++) {
5552 const struct ssh_kexes *k = s->preferred_kex[i];
5553 if (!k) continue; /* warning flag */
5554 for (j = 0; j < k->nkexes; j++) {
5555 if (commalist_started)
5556 ssh2_pkt_addstring_str(s->pktout, ",");
5557 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5558 commalist_started = 1;
5561 /* List server host key algorithms. */
5562 ssh2_pkt_addstring_start(s->pktout);
5563 for (i = 0; i < lenof(hostkey_algs); i++) {
5564 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5565 if (i < lenof(hostkey_algs) - 1)
5566 ssh2_pkt_addstring_str(s->pktout, ",");
5568 /* List client->server encryption algorithms. */
5569 ssh2_pkt_addstring_start(s->pktout);
5570 commalist_started = 0;
5571 for (i = 0; i < s->n_preferred_ciphers; i++) {
5572 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5573 if (!c) continue; /* warning flag */
5574 for (j = 0; j < c->nciphers; j++) {
5575 if (commalist_started)
5576 ssh2_pkt_addstring_str(s->pktout, ",");
5577 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5578 commalist_started = 1;
5581 /* List server->client encryption algorithms. */
5582 ssh2_pkt_addstring_start(s->pktout);
5583 commalist_started = 0;
5584 for (i = 0; i < s->n_preferred_ciphers; i++) {
5585 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5586 if (!c) continue; /* warning flag */
5587 for (j = 0; j < c->nciphers; j++) {
5588 if (commalist_started)
5589 ssh2_pkt_addstring_str(s->pktout, ",");
5590 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5591 commalist_started = 1;
5594 /* List client->server MAC algorithms. */
5595 ssh2_pkt_addstring_start(s->pktout);
5596 for (i = 0; i < s->nmacs; i++) {
5597 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5598 if (i < s->nmacs - 1)
5599 ssh2_pkt_addstring_str(s->pktout, ",");
5601 /* List server->client MAC algorithms. */
5602 ssh2_pkt_addstring_start(s->pktout);
5603 for (i = 0; i < s->nmacs; i++) {
5604 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5605 if (i < s->nmacs - 1)
5606 ssh2_pkt_addstring_str(s->pktout, ",");
5608 /* List client->server compression algorithms,
5609 * then server->client compression algorithms. (We use the
5610 * same set twice.) */
5611 for (j = 0; j < 2; j++) {
5612 ssh2_pkt_addstring_start(s->pktout);
5613 assert(lenof(compressions) > 1);
5614 /* Prefer non-delayed versions */
5615 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5616 /* We don't even list delayed versions of algorithms until
5617 * they're allowed to be used, to avoid a race. See the end of
5619 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
5620 ssh2_pkt_addstring_str(s->pktout, ",");
5621 ssh2_pkt_addstring_str(s->pktout,
5622 s->preferred_comp->delayed_name);
5624 for (i = 0; i < lenof(compressions); i++) {
5625 const struct ssh_compress *c = compressions[i];
5626 if (c != s->preferred_comp) {
5627 ssh2_pkt_addstring_str(s->pktout, ",");
5628 ssh2_pkt_addstring_str(s->pktout, c->name);
5629 if (s->userauth_succeeded && c->delayed_name) {
5630 ssh2_pkt_addstring_str(s->pktout, ",");
5631 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5636 /* List client->server languages. Empty list. */
5637 ssh2_pkt_addstring_start(s->pktout);
5638 /* List server->client languages. Empty list. */
5639 ssh2_pkt_addstring_start(s->pktout);
5640 /* First KEX packet does _not_ follow, because we're not that brave. */
5641 ssh2_pkt_addbool(s->pktout, FALSE);
5643 ssh2_pkt_adduint32(s->pktout, 0);
5646 s->our_kexinitlen = s->pktout->length - 5;
5647 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5648 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5650 ssh2_pkt_send_noqueue(ssh, s->pktout);
5656 * Now examine the other side's KEXINIT to see what we're up
5660 char *str, *preferred;
5663 if (pktin->type != SSH2_MSG_KEXINIT) {
5664 bombout(("expected key exchange packet from server"));
5668 ssh->hostkey = NULL;
5669 s->cscipher_tobe = NULL;
5670 s->sccipher_tobe = NULL;
5671 s->csmac_tobe = NULL;
5672 s->scmac_tobe = NULL;
5673 s->cscomp_tobe = NULL;
5674 s->sccomp_tobe = NULL;
5675 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5677 pktin->savedpos += 16; /* skip garbage cookie */
5678 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5681 for (i = 0; i < s->n_preferred_kex; i++) {
5682 const struct ssh_kexes *k = s->preferred_kex[i];
5686 for (j = 0; j < k->nkexes; j++) {
5687 if (!preferred) preferred = k->list[j]->name;
5688 if (in_commasep_string(k->list[j]->name, str, len)) {
5689 ssh->kex = k->list[j];
5698 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5699 str ? str : "(null)"));
5703 * Note that the server's guess is considered wrong if it doesn't match
5704 * the first algorithm in our list, even if it's still the algorithm
5707 s->guessok = first_in_commasep_string(preferred, str, len);
5708 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5709 for (i = 0; i < lenof(hostkey_algs); i++) {
5710 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5711 ssh->hostkey = hostkey_algs[i];
5715 s->guessok = s->guessok &&
5716 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5717 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5718 for (i = 0; i < s->n_preferred_ciphers; i++) {
5719 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5721 s->warn_cscipher = TRUE;
5723 for (j = 0; j < c->nciphers; j++) {
5724 if (in_commasep_string(c->list[j]->name, str, len)) {
5725 s->cscipher_tobe = c->list[j];
5730 if (s->cscipher_tobe)
5733 if (!s->cscipher_tobe) {
5734 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5735 str ? str : "(null)"));
5739 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5740 for (i = 0; i < s->n_preferred_ciphers; i++) {
5741 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5743 s->warn_sccipher = TRUE;
5745 for (j = 0; j < c->nciphers; j++) {
5746 if (in_commasep_string(c->list[j]->name, str, len)) {
5747 s->sccipher_tobe = c->list[j];
5752 if (s->sccipher_tobe)
5755 if (!s->sccipher_tobe) {
5756 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5757 str ? str : "(null)"));
5761 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5762 for (i = 0; i < s->nmacs; i++) {
5763 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5764 s->csmac_tobe = s->maclist[i];
5768 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5769 for (i = 0; i < s->nmacs; i++) {
5770 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5771 s->scmac_tobe = s->maclist[i];
5775 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5776 for (i = 0; i < lenof(compressions) + 1; i++) {
5777 const struct ssh_compress *c =
5778 i == 0 ? s->preferred_comp : compressions[i - 1];
5779 if (in_commasep_string(c->name, str, len)) {
5782 } else if (in_commasep_string(c->delayed_name, str, len)) {
5783 if (s->userauth_succeeded) {
5787 s->pending_compression = TRUE; /* try this later */
5791 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5792 for (i = 0; i < lenof(compressions) + 1; i++) {
5793 const struct ssh_compress *c =
5794 i == 0 ? s->preferred_comp : compressions[i - 1];
5795 if (in_commasep_string(c->name, str, len)) {
5798 } else if (in_commasep_string(c->delayed_name, str, len)) {
5799 if (s->userauth_succeeded) {
5803 s->pending_compression = TRUE; /* try this later */
5807 if (s->pending_compression) {
5808 logevent("Server supports delayed compression; "
5809 "will try this later");
5811 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5812 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5813 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5816 ssh_set_frozen(ssh, 1);
5817 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5819 ssh_dialog_callback, ssh);
5820 if (s->dlgret < 0) {
5824 bombout(("Unexpected data from server while"
5825 " waiting for user response"));
5828 } while (pktin || inlen > 0);
5829 s->dlgret = ssh->user_response;
5831 ssh_set_frozen(ssh, 0);
5832 if (s->dlgret == 0) {
5833 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5839 if (s->warn_cscipher) {
5840 ssh_set_frozen(ssh, 1);
5841 s->dlgret = askalg(ssh->frontend,
5842 "client-to-server cipher",
5843 s->cscipher_tobe->name,
5844 ssh_dialog_callback, ssh);
5845 if (s->dlgret < 0) {
5849 bombout(("Unexpected data from server while"
5850 " waiting for user response"));
5853 } while (pktin || inlen > 0);
5854 s->dlgret = ssh->user_response;
5856 ssh_set_frozen(ssh, 0);
5857 if (s->dlgret == 0) {
5858 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5864 if (s->warn_sccipher) {
5865 ssh_set_frozen(ssh, 1);
5866 s->dlgret = askalg(ssh->frontend,
5867 "server-to-client cipher",
5868 s->sccipher_tobe->name,
5869 ssh_dialog_callback, ssh);
5870 if (s->dlgret < 0) {
5874 bombout(("Unexpected data from server while"
5875 " waiting for user response"));
5878 } while (pktin || inlen > 0);
5879 s->dlgret = ssh->user_response;
5881 ssh_set_frozen(ssh, 0);
5882 if (s->dlgret == 0) {
5883 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5889 ssh->exhash = ssh->kex->hash->init();
5890 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5891 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5892 hash_string(ssh->kex->hash, ssh->exhash,
5893 s->our_kexinit, s->our_kexinitlen);
5894 sfree(s->our_kexinit);
5895 if (pktin->length > 5)
5896 hash_string(ssh->kex->hash, ssh->exhash,
5897 pktin->data + 5, pktin->length - 5);
5899 if (s->ignorepkt) /* first_kex_packet_follows */
5900 crWaitUntil(pktin); /* Ignore packet */
5903 if (ssh->kex->main_type == KEXTYPE_DH) {
5905 * Work out the number of bits of key we will need from the
5906 * key exchange. We start with the maximum key length of
5912 csbits = s->cscipher_tobe->keylen;
5913 scbits = s->sccipher_tobe->keylen;
5914 s->nbits = (csbits > scbits ? csbits : scbits);
5916 /* The keys only have hlen-bit entropy, since they're based on
5917 * a hash. So cap the key size at hlen bits. */
5918 if (s->nbits > ssh->kex->hash->hlen * 8)
5919 s->nbits = ssh->kex->hash->hlen * 8;
5922 * If we're doing Diffie-Hellman group exchange, start by
5923 * requesting a group.
5925 if (!ssh->kex->pdata) {
5926 logevent("Doing Diffie-Hellman group exchange");
5927 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
5929 * Work out how big a DH group we will need to allow that
5932 s->pbits = 512 << ((s->nbits - 1) / 64);
5933 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5934 ssh2_pkt_adduint32(s->pktout, s->pbits);
5935 ssh2_pkt_send_noqueue(ssh, s->pktout);
5938 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5939 bombout(("expected key exchange group packet from server"));
5942 s->p = ssh2_pkt_getmp(pktin);
5943 s->g = ssh2_pkt_getmp(pktin);
5944 if (!s->p || !s->g) {
5945 bombout(("unable to read mp-ints from incoming group packet"));
5948 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5949 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5950 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5952 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
5953 ssh->kex_ctx = dh_setup_group(ssh->kex);
5954 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5955 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5956 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5957 ssh->kex->groupname);
5960 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5961 ssh->kex->hash->text_name);
5963 * Now generate and send e for Diffie-Hellman.
5965 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5966 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5967 s->pktout = ssh2_pkt_init(s->kex_init_value);
5968 ssh2_pkt_addmp(s->pktout, s->e);
5969 ssh2_pkt_send_noqueue(ssh, s->pktout);
5971 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5973 if (pktin->type != s->kex_reply_value) {
5974 bombout(("expected key exchange reply packet from server"));
5977 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5978 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5979 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5980 s->f = ssh2_pkt_getmp(pktin);
5982 bombout(("unable to parse key exchange reply packet"));
5985 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5987 s->K = dh_find_K(ssh->kex_ctx, s->f);
5989 /* We assume everything from now on will be quick, and it might
5990 * involve user interaction. */
5991 set_busy_status(ssh->frontend, BUSY_NOT);
5993 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5994 if (!ssh->kex->pdata) {
5995 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5996 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5997 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5999 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6000 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6002 dh_cleanup(ssh->kex_ctx);
6004 if (!ssh->kex->pdata) {
6009 logeventf(ssh, "Doing RSA key exchange with hash %s",
6010 ssh->kex->hash->text_name);
6011 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6013 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6017 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6018 bombout(("expected RSA public key packet from server"));
6022 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6023 hash_string(ssh->kex->hash, ssh->exhash,
6024 s->hostkeydata, s->hostkeylen);
6025 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6029 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6030 s->rsakeydata = snewn(s->rsakeylen, char);
6031 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6034 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6036 sfree(s->rsakeydata);
6037 bombout(("unable to parse RSA public key from server"));
6041 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6044 * Next, set up a shared secret K, of precisely KLEN -
6045 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6046 * RSA key modulus and HLEN is the bit length of the hash
6050 int klen = ssh_rsakex_klen(s->rsakey);
6051 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6053 unsigned char *kstr1, *kstr2, *outstr;
6054 int kstr1len, kstr2len, outstrlen;
6056 s->K = bn_power_2(nbits - 1);
6058 for (i = 0; i < nbits; i++) {
6060 byte = random_byte();
6062 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6066 * Encode this as an mpint.
6068 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6069 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6070 PUT_32BIT(kstr2, kstr1len);
6071 memcpy(kstr2 + 4, kstr1, kstr1len);
6074 * Encrypt it with the given RSA key.
6076 outstrlen = (klen + 7) / 8;
6077 outstr = snewn(outstrlen, unsigned char);
6078 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6079 outstr, outstrlen, s->rsakey);
6082 * And send it off in a return packet.
6084 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6085 ssh2_pkt_addstring_start(s->pktout);
6086 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6087 ssh2_pkt_send_noqueue(ssh, s->pktout);
6089 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6096 ssh_rsakex_freekey(s->rsakey);
6099 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6100 sfree(s->rsakeydata);
6101 bombout(("expected signature packet from server"));
6105 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6107 sfree(s->rsakeydata);
6110 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6111 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6112 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6114 ssh->kex_ctx = NULL;
6117 debug(("Exchange hash is:\n"));
6118 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6122 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6123 (char *)s->exchange_hash,
6124 ssh->kex->hash->hlen)) {
6125 bombout(("Server's host key did not match the signature supplied"));
6130 * Authenticate remote host: verify host key. (We've already
6131 * checked the signature of the exchange hash.)
6133 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6134 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6135 ssh_set_frozen(ssh, 1);
6136 s->dlgret = verify_ssh_host_key(ssh->frontend,
6137 ssh->savedhost, ssh->savedport,
6138 ssh->hostkey->keytype, s->keystr,
6140 ssh_dialog_callback, ssh);
6141 if (s->dlgret < 0) {
6145 bombout(("Unexpected data from server while waiting"
6146 " for user host key response"));
6149 } while (pktin || inlen > 0);
6150 s->dlgret = ssh->user_response;
6152 ssh_set_frozen(ssh, 0);
6153 if (s->dlgret == 0) {
6154 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6158 if (!s->got_session_id) { /* don't bother logging this in rekeys */
6159 logevent("Host key fingerprint is:");
6160 logevent(s->fingerprint);
6162 sfree(s->fingerprint);
6164 ssh->hostkey->freekey(s->hkey);
6167 * The exchange hash from the very first key exchange is also
6168 * the session id, used in session key construction and
6171 if (!s->got_session_id) {
6172 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6173 memcpy(ssh->v2_session_id, s->exchange_hash,
6174 sizeof(s->exchange_hash));
6175 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6176 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6177 s->got_session_id = TRUE;
6181 * Send SSH2_MSG_NEWKEYS.
6183 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6184 ssh2_pkt_send_noqueue(ssh, s->pktout);
6185 ssh->outgoing_data_size = 0; /* start counting from here */
6188 * We've sent client NEWKEYS, so create and initialise
6189 * client-to-server session keys.
6191 if (ssh->cs_cipher_ctx)
6192 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6193 ssh->cscipher = s->cscipher_tobe;
6194 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6196 if (ssh->cs_mac_ctx)
6197 ssh->csmac->free_context(ssh->cs_mac_ctx);
6198 ssh->csmac = s->csmac_tobe;
6199 ssh->cs_mac_ctx = ssh->csmac->make_context();
6201 if (ssh->cs_comp_ctx)
6202 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6203 ssh->cscomp = s->cscomp_tobe;
6204 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6207 * Set IVs on client-to-server keys. Here we use the exchange
6208 * hash from the _first_ key exchange.
6211 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6212 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6213 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6214 assert((ssh->cscipher->keylen+7) / 8 <=
6215 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6216 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6217 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6218 assert(ssh->cscipher->blksize <=
6219 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6220 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6221 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6222 assert(ssh->csmac->len <=
6223 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6224 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6225 memset(keyspace, 0, sizeof(keyspace));
6228 logeventf(ssh, "Initialised %.200s client->server encryption",
6229 ssh->cscipher->text_name);
6230 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6231 ssh->csmac->text_name);
6232 if (ssh->cscomp->text_name)
6233 logeventf(ssh, "Initialised %s compression",
6234 ssh->cscomp->text_name);
6237 * Now our end of the key exchange is complete, we can send all
6238 * our queued higher-layer packets.
6240 ssh->queueing = FALSE;
6241 ssh2_pkt_queuesend(ssh);
6244 * Expect SSH2_MSG_NEWKEYS from server.
6247 if (pktin->type != SSH2_MSG_NEWKEYS) {
6248 bombout(("expected new-keys packet from server"));
6251 ssh->incoming_data_size = 0; /* start counting from here */
6254 * We've seen server NEWKEYS, so create and initialise
6255 * server-to-client session keys.
6257 if (ssh->sc_cipher_ctx)
6258 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6259 ssh->sccipher = s->sccipher_tobe;
6260 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6262 if (ssh->sc_mac_ctx)
6263 ssh->scmac->free_context(ssh->sc_mac_ctx);
6264 ssh->scmac = s->scmac_tobe;
6265 ssh->sc_mac_ctx = ssh->scmac->make_context();
6267 if (ssh->sc_comp_ctx)
6268 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6269 ssh->sccomp = s->sccomp_tobe;
6270 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6273 * Set IVs on server-to-client keys. Here we use the exchange
6274 * hash from the _first_ key exchange.
6277 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6278 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6279 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6280 assert((ssh->sccipher->keylen+7) / 8 <=
6281 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6282 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6283 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6284 assert(ssh->sccipher->blksize <=
6285 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6286 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6287 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6288 assert(ssh->scmac->len <=
6289 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6290 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6291 memset(keyspace, 0, sizeof(keyspace));
6293 logeventf(ssh, "Initialised %.200s server->client encryption",
6294 ssh->sccipher->text_name);
6295 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6296 ssh->scmac->text_name);
6297 if (ssh->sccomp->text_name)
6298 logeventf(ssh, "Initialised %s decompression",
6299 ssh->sccomp->text_name);
6302 * Free shared secret.
6307 * Key exchange is over. Loop straight back round if we have a
6308 * deferred rekey reason.
6310 if (ssh->deferred_rekey_reason) {
6311 logevent(ssh->deferred_rekey_reason);
6313 ssh->deferred_rekey_reason = NULL;
6314 goto begin_key_exchange;
6318 * Otherwise, schedule a timer for our next rekey.
6320 ssh->kex_in_progress = FALSE;
6321 ssh->last_rekey = GETTICKCOUNT();
6322 if (ssh->cfg.ssh_rekey_time != 0)
6323 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6327 * If this is the first key exchange phase, we must pass the
6328 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6329 * wants to see it but because it will need time to initialise
6330 * itself before it sees an actual packet. In subsequent key
6331 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6332 * it would only confuse the layer above.
6334 if (s->activated_authconn) {
6337 s->activated_authconn = TRUE;
6340 * Now we're encrypting. Begin returning 1 to the protocol main
6341 * function so that other things can run on top of the
6342 * transport. If we ever see a KEXINIT, we must go back to the
6345 * We _also_ go back to the start if we see pktin==NULL and
6346 * inlen negative, because this is a special signal meaning
6347 * `initiate client-driven rekey', and `in' contains a message
6348 * giving the reason for the rekey.
6350 * inlen==-1 means always initiate a rekey;
6351 * inlen==-2 means that userauth has completed successfully and
6352 * we should consider rekeying (for delayed compression).
6354 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6355 (!pktin && inlen < 0))) {
6360 logevent("Server initiated key re-exchange");
6364 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6365 * delayed compression, if it's available.
6367 * draft-miller-secsh-compression-delayed-00 says that you
6368 * negotiate delayed compression in the first key exchange, and
6369 * both sides start compressing when the server has sent
6370 * USERAUTH_SUCCESS. This has a race condition -- the server
6371 * can't know when the client has seen it, and thus which incoming
6372 * packets it should treat as compressed.
6374 * Instead, we do the initial key exchange without offering the
6375 * delayed methods, but note if the server offers them; when we
6376 * get here, if a delayed method was available that was higher
6377 * on our list than what we got, we initiate a rekey in which we
6378 * _do_ list the delayed methods (and hopefully get it as a
6379 * result). Subsequent rekeys will do the same.
6381 assert(!s->userauth_succeeded); /* should only happen once */
6382 s->userauth_succeeded = TRUE;
6383 if (!s->pending_compression)
6384 /* Can't see any point rekeying. */
6385 goto wait_for_rekey; /* this is utterly horrid */
6386 /* else fall through to rekey... */
6387 s->pending_compression = FALSE;
6390 * Now we've decided to rekey.
6392 * Special case: if the server bug is set that doesn't
6393 * allow rekeying, we give a different log message and
6394 * continue waiting. (If such a server _initiates_ a rekey,
6395 * we process it anyway!)
6397 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6398 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6400 /* Reset the counters, so that at least this message doesn't
6401 * hit the event log _too_ often. */
6402 ssh->outgoing_data_size = 0;
6403 ssh->incoming_data_size = 0;
6404 if (ssh->cfg.ssh_rekey_time != 0) {
6406 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6409 goto wait_for_rekey; /* this is still utterly horrid */
6411 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6414 goto begin_key_exchange;
6420 * Add data to an SSH-2 channel output buffer.
6422 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6425 bufchain_add(&c->v.v2.outbuffer, buf, len);
6429 * Attempt to send data on an SSH-2 channel.
6431 static int ssh2_try_send(struct ssh_channel *c)
6434 struct Packet *pktout;
6436 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6439 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6440 if ((unsigned)len > c->v.v2.remwindow)
6441 len = c->v.v2.remwindow;
6442 if ((unsigned)len > c->v.v2.remmaxpkt)
6443 len = c->v.v2.remmaxpkt;
6444 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6445 ssh2_pkt_adduint32(pktout, c->remoteid);
6446 ssh2_pkt_addstring_start(pktout);
6447 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6448 ssh2_pkt_addstring_data(pktout, data, len);
6449 end_log_omission(ssh, pktout);
6450 ssh2_pkt_send(ssh, pktout);
6451 bufchain_consume(&c->v.v2.outbuffer, len);
6452 c->v.v2.remwindow -= len;
6456 * After having sent as much data as we can, return the amount
6459 return bufchain_size(&c->v.v2.outbuffer);
6462 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6466 return; /* don't send on closing channels */
6467 bufsize = ssh2_try_send(c);
6470 case CHAN_MAINSESSION:
6471 /* stdin need not receive an unthrottle
6472 * notification since it will be polled */
6475 x11_unthrottle(c->u.x11.s);
6478 /* agent sockets are request/response and need no
6479 * buffer management */
6482 pfd_unthrottle(c->u.pfd.s);
6488 * If we've emptied the channel's output buffer and there's a
6489 * pending close event, start the channel-closing procedure.
6491 if (c->pending_close && bufchain_size(&c->v.v2.outbuffer) == 0) {
6492 struct Packet *pktout;
6493 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6494 ssh2_pkt_adduint32(pktout, c->remoteid);
6495 ssh2_pkt_send(ssh, pktout);
6497 c->pending_close = FALSE;
6502 * Set up most of a new ssh_channel for SSH-2.
6504 static void ssh2_channel_init(struct ssh_channel *c)
6507 c->localid = alloc_channel_id(ssh);
6509 c->pending_close = FALSE;
6510 c->throttling_conn = FALSE;
6511 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6512 ssh->cfg.ssh_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6513 c->v.v2.winadj_head = c->v.v2.winadj_tail = NULL;
6514 c->v.v2.throttle_state = UNTHROTTLED;
6515 bufchain_init(&c->v.v2.outbuffer);
6519 * Potentially enlarge the window on an SSH-2 channel.
6521 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6526 * Never send WINDOW_ADJUST for a channel that the remote side
6527 * already thinks it's closed; there's no point, since it won't
6528 * be sending any more data anyway.
6534 * If the remote end has a habit of ignoring maxpkt, limit the
6535 * window so that it has no choice (assuming it doesn't ignore the
6538 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6539 newwin = OUR_V2_MAXPKT;
6543 * Only send a WINDOW_ADJUST if there's significantly more window
6544 * available than the other end thinks there is. This saves us
6545 * sending a WINDOW_ADJUST for every character in a shell session.
6547 * "Significant" is arbitrarily defined as half the window size.
6549 if (newwin / 2 >= c->v.v2.locwindow) {
6550 struct Packet *pktout;
6554 * In order to keep track of how much window the client
6555 * actually has available, we'd like it to acknowledge each
6556 * WINDOW_ADJUST. We can't do that directly, so we accompany
6557 * it with a CHANNEL_REQUEST that has to be acknowledged.
6559 * This is only necessary if we're opening the window wide.
6560 * If we're not, then throughput is being constrained by
6561 * something other than the maximum window size anyway.
6563 * We also only send this if the main channel has finished its
6564 * initial CHANNEL_REQUESTs and installed the default
6565 * CHANNEL_FAILURE handler, so as not to risk giving it
6566 * unexpected CHANNEL_FAILUREs.
6568 if (newwin == c->v.v2.locmaxwin &&
6569 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE]) {
6570 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6571 ssh2_pkt_adduint32(pktout, c->remoteid);
6572 ssh2_pkt_addstring(pktout, "winadj@putty.projects.tartarus.org");
6573 ssh2_pkt_addbool(pktout, TRUE);
6574 ssh2_pkt_send(ssh, pktout);
6577 * CHANNEL_FAILURE doesn't come with any indication of
6578 * what message caused it, so we have to keep track of the
6579 * outstanding CHANNEL_REQUESTs ourselves.
6581 wa = snew(struct winadj);
6582 wa->size = newwin - c->v.v2.locwindow;
6584 if (!c->v.v2.winadj_head)
6585 c->v.v2.winadj_head = wa;
6587 c->v.v2.winadj_tail->next = wa;
6588 c->v.v2.winadj_tail = wa;
6589 if (c->v.v2.throttle_state != UNTHROTTLED)
6590 c->v.v2.throttle_state = UNTHROTTLING;
6592 /* Pretend the WINDOW_ADJUST was acked immediately. */
6593 c->v.v2.remlocwin = newwin;
6594 c->v.v2.throttle_state = THROTTLED;
6596 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6597 ssh2_pkt_adduint32(pktout, c->remoteid);
6598 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6599 ssh2_pkt_send(ssh, pktout);
6600 c->v.v2.locwindow = newwin;
6605 * Find the channel associated with a message. If there's no channel,
6606 * or it's not properly open, make a noise about it and return NULL.
6608 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6610 unsigned localid = ssh_pkt_getuint32(pktin);
6611 struct ssh_channel *c;
6613 c = find234(ssh->channels, &localid, ssh_channelfind);
6615 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6616 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6617 char *buf = dupprintf("Received %s for %s channel %u",
6618 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6620 c ? "half-open" : "nonexistent", localid);
6621 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6628 static void ssh2_msg_channel_success(Ssh ssh, struct Packet *pktin)
6631 * This should never get called. All channel requests are either
6632 * sent with want_reply false or are sent before this handler gets
6635 struct ssh_channel *c;
6638 c = ssh2_channel_msg(ssh, pktin);
6641 wa = c->v.v2.winadj_head;
6643 ssh_disconnect(ssh, NULL, "Received SSH_MSG_CHANNEL_SUCCESS for "
6644 "\"winadj@putty.projects.tartarus.org\"",
6645 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6647 ssh_disconnect(ssh, NULL,
6648 "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
6649 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6652 static void ssh2_msg_channel_failure(Ssh ssh, struct Packet *pktin)
6655 * The only time this should get called is for "winadj@putty"
6656 * messages sent above. All other channel requests are either
6657 * sent with want_reply false or are sent before this handler gets
6660 struct ssh_channel *c;
6663 c = ssh2_channel_msg(ssh, pktin);
6666 wa = c->v.v2.winadj_head;
6668 ssh_disconnect(ssh, NULL,
6669 "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
6670 SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6673 c->v.v2.winadj_head = wa->next;
6674 c->v.v2.remlocwin += wa->size;
6677 * winadj messages are only sent when the window is fully open, so
6678 * if we get an ack of one, we know any pending unthrottle is
6681 if (c->v.v2.throttle_state == UNTHROTTLING)
6682 c->v.v2.throttle_state = UNTHROTTLED;
6685 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6687 struct ssh_channel *c;
6688 c = ssh2_channel_msg(ssh, pktin);
6692 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6693 ssh2_try_send_and_unthrottle(ssh, c);
6697 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6701 struct ssh_channel *c;
6702 c = ssh2_channel_msg(ssh, pktin);
6705 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6706 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6707 return; /* extended but not stderr */
6708 ssh_pkt_getstring(pktin, &data, &length);
6711 c->v.v2.locwindow -= length;
6712 c->v.v2.remlocwin -= length;
6714 case CHAN_MAINSESSION:
6716 from_backend(ssh->frontend, pktin->type ==
6717 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6721 bufsize = x11_send(c->u.x11.s, data, length);
6724 bufsize = pfd_send(c->u.pfd.s, data, length);
6727 while (length > 0) {
6728 if (c->u.a.lensofar < 4) {
6729 unsigned int l = min(4 - c->u.a.lensofar,
6731 memcpy(c->u.a.msglen + c->u.a.lensofar,
6735 c->u.a.lensofar += l;
6737 if (c->u.a.lensofar == 4) {
6739 4 + GET_32BIT(c->u.a.msglen);
6740 c->u.a.message = snewn(c->u.a.totallen,
6742 memcpy(c->u.a.message, c->u.a.msglen, 4);
6744 if (c->u.a.lensofar >= 4 && length > 0) {
6746 min(c->u.a.totallen - c->u.a.lensofar,
6748 memcpy(c->u.a.message + c->u.a.lensofar,
6752 c->u.a.lensofar += l;
6754 if (c->u.a.lensofar == c->u.a.totallen) {
6757 if (agent_query(c->u.a.message,
6760 ssh_agentf_callback, c))
6761 ssh_agentf_callback(c, reply, replylen);
6762 sfree(c->u.a.message);
6763 c->u.a.lensofar = 0;
6770 * If it looks like the remote end hit the end of its window,
6771 * and we didn't want it to do that, think about using a
6774 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6775 c->v.v2.locmaxwin < 0x40000000)
6776 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6778 * If we are not buffering too much data,
6779 * enlarge the window again at the remote side.
6780 * If we are buffering too much, we may still
6781 * need to adjust the window if the server's
6784 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6785 c->v.v2.locmaxwin - bufsize : 0);
6787 * If we're either buffering way too much data, or if we're
6788 * buffering anything at all and we're in "simple" mode,
6789 * throttle the whole channel.
6791 if ((bufsize > c->v.v2.locmaxwin ||
6792 (ssh->cfg.ssh_simple && bufsize > 0)) &&
6793 !c->throttling_conn) {
6794 c->throttling_conn = 1;
6795 ssh_throttle_conn(ssh, +1);
6800 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6802 struct ssh_channel *c;
6804 c = ssh2_channel_msg(ssh, pktin);
6808 if (c->type == CHAN_X11) {
6810 * Remote EOF on an X11 channel means we should
6811 * wrap up and close the channel ourselves.
6813 x11_close(c->u.x11.s);
6816 } else if (c->type == CHAN_AGENT) {
6818 } else if (c->type == CHAN_SOCKDATA) {
6819 pfd_close(c->u.pfd.s);
6825 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6827 struct ssh_channel *c;
6828 struct Packet *pktout;
6830 c = ssh2_channel_msg(ssh, pktin);
6833 /* Do pre-close processing on the channel. */
6835 case CHAN_MAINSESSION:
6836 ssh->mainchan = NULL;
6837 update_specials_menu(ssh->frontend);
6840 if (c->u.x11.s != NULL)
6841 x11_close(c->u.x11.s);
6848 if (c->u.pfd.s != NULL)
6849 pfd_close(c->u.pfd.s);
6853 if (c->closes == 0) {
6854 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6855 ssh2_pkt_adduint32(pktout, c->remoteid);
6856 ssh2_pkt_send(ssh, pktout);
6858 del234(ssh->channels, c);
6859 bufchain_clear(&c->v.v2.outbuffer);
6863 * See if that was the last channel left open.
6864 * (This is only our termination condition if we're
6865 * not running in -N mode.)
6867 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6869 * We used to send SSH_MSG_DISCONNECT here,
6870 * because I'd believed that _every_ conforming
6871 * SSH-2 connection had to end with a disconnect
6872 * being sent by at least one side; apparently
6873 * I was wrong and it's perfectly OK to
6874 * unceremoniously slam the connection shut
6875 * when you're done, and indeed OpenSSH feels
6876 * this is more polite than sending a
6877 * DISCONNECT. So now we don't.
6879 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6883 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6885 struct ssh_channel *c;
6886 struct Packet *pktout;
6888 c = ssh2_channel_msg(ssh, pktin);
6891 if (c->type != CHAN_SOCKDATA_DORMANT)
6892 return; /* dunno why they're confirming this */
6893 c->remoteid = ssh_pkt_getuint32(pktin);
6894 c->halfopen = FALSE;
6895 c->type = CHAN_SOCKDATA;
6896 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6897 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6899 pfd_confirm(c->u.pfd.s);
6902 * We have a pending close on this channel,
6903 * which we decided on before the server acked
6904 * the channel open. So now we know the
6905 * remoteid, we can close it again.
6907 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6908 ssh2_pkt_adduint32(pktout, c->remoteid);
6909 ssh2_pkt_send(ssh, pktout);
6913 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6915 static const char *const reasons[] = {
6916 "<unknown reason code>",
6917 "Administratively prohibited",
6919 "Unknown channel type",
6920 "Resource shortage",
6922 unsigned reason_code;
6923 char *reason_string;
6925 struct ssh_channel *c;
6926 c = ssh2_channel_msg(ssh, pktin);
6929 if (c->type != CHAN_SOCKDATA_DORMANT)
6930 return; /* dunno why they're failing this */
6932 reason_code = ssh_pkt_getuint32(pktin);
6933 if (reason_code >= lenof(reasons))
6934 reason_code = 0; /* ensure reasons[reason_code] in range */
6935 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6936 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6937 reasons[reason_code], reason_length, reason_string);
6939 pfd_close(c->u.pfd.s);
6941 del234(ssh->channels, c);
6945 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6948 int typelen, want_reply;
6949 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6950 struct ssh_channel *c;
6951 struct Packet *pktout;
6953 c = ssh2_channel_msg(ssh, pktin);
6956 ssh_pkt_getstring(pktin, &type, &typelen);
6957 want_reply = ssh2_pkt_getbool(pktin);
6960 * Having got the channel number, we now look at
6961 * the request type string to see if it's something
6964 if (c == ssh->mainchan) {
6966 * We recognise "exit-status" and "exit-signal" on
6967 * the primary channel.
6969 if (typelen == 11 &&
6970 !memcmp(type, "exit-status", 11)) {
6972 ssh->exitcode = ssh_pkt_getuint32(pktin);
6973 logeventf(ssh, "Server sent command exit status %d",
6975 reply = SSH2_MSG_CHANNEL_SUCCESS;
6977 } else if (typelen == 11 &&
6978 !memcmp(type, "exit-signal", 11)) {
6980 int is_plausible = TRUE, is_int = FALSE;
6981 char *fmt_sig = "", *fmt_msg = "";
6983 int msglen = 0, core = FALSE;
6984 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6985 * provide an `int' for the signal, despite its
6986 * having been a `string' in the drafts of RFC 4254 since at
6987 * least 2001. (Fixed in session.c 1.147.) Try to
6988 * infer which we can safely parse it as. */
6990 unsigned char *p = pktin->body +
6992 long len = pktin->length - pktin->savedpos;
6993 unsigned long num = GET_32BIT(p); /* what is it? */
6994 /* If it's 0, it hardly matters; assume string */
6998 int maybe_int = FALSE, maybe_str = FALSE;
6999 #define CHECK_HYPOTHESIS(offset, result) \
7002 if (q >= 0 && q+4 <= len) { \
7003 q = q + 4 + GET_32BIT(p+q); \
7004 if (q >= 0 && q+4 <= len && \
7005 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
7009 CHECK_HYPOTHESIS(4+1, maybe_int);
7010 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7011 #undef CHECK_HYPOTHESIS
7012 if (maybe_int && !maybe_str)
7014 else if (!maybe_int && maybe_str)
7017 /* Crikey. Either or neither. Panic. */
7018 is_plausible = FALSE;
7021 ssh->exitcode = 128; /* means `unknown signal' */
7024 /* Old non-standard OpenSSH. */
7025 int signum = ssh_pkt_getuint32(pktin);
7026 fmt_sig = dupprintf(" %d", signum);
7027 ssh->exitcode = 128 + signum;
7029 /* As per RFC 4254. */
7032 ssh_pkt_getstring(pktin, &sig, &siglen);
7033 /* Signal name isn't supposed to be blank, but
7034 * let's cope gracefully if it is. */
7036 fmt_sig = dupprintf(" \"%.*s\"",
7041 * Really hideous method of translating the
7042 * signal description back into a locally
7043 * meaningful number.
7048 #define TRANSLATE_SIGNAL(s) \
7049 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7050 ssh->exitcode = 128 + SIG ## s
7052 TRANSLATE_SIGNAL(ABRT);
7055 TRANSLATE_SIGNAL(ALRM);
7058 TRANSLATE_SIGNAL(FPE);
7061 TRANSLATE_SIGNAL(HUP);
7064 TRANSLATE_SIGNAL(ILL);
7067 TRANSLATE_SIGNAL(INT);
7070 TRANSLATE_SIGNAL(KILL);
7073 TRANSLATE_SIGNAL(PIPE);
7076 TRANSLATE_SIGNAL(QUIT);
7079 TRANSLATE_SIGNAL(SEGV);
7082 TRANSLATE_SIGNAL(TERM);
7085 TRANSLATE_SIGNAL(USR1);
7088 TRANSLATE_SIGNAL(USR2);
7090 #undef TRANSLATE_SIGNAL
7092 ssh->exitcode = 128;
7094 core = ssh2_pkt_getbool(pktin);
7095 ssh_pkt_getstring(pktin, &msg, &msglen);
7097 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7099 /* ignore lang tag */
7100 } /* else don't attempt to parse */
7101 logeventf(ssh, "Server exited on signal%s%s%s",
7102 fmt_sig, core ? " (core dumped)" : "",
7104 if (*fmt_sig) sfree(fmt_sig);
7105 if (*fmt_msg) sfree(fmt_msg);
7106 reply = SSH2_MSG_CHANNEL_SUCCESS;
7111 * This is a channel request we don't know
7112 * about, so we now either ignore the request
7113 * or respond with CHANNEL_FAILURE, depending
7116 reply = SSH2_MSG_CHANNEL_FAILURE;
7119 pktout = ssh2_pkt_init(reply);
7120 ssh2_pkt_adduint32(pktout, c->remoteid);
7121 ssh2_pkt_send(ssh, pktout);
7125 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7128 int typelen, want_reply;
7129 struct Packet *pktout;
7131 ssh_pkt_getstring(pktin, &type, &typelen);
7132 want_reply = ssh2_pkt_getbool(pktin);
7135 * We currently don't support any global requests
7136 * at all, so we either ignore the request or
7137 * respond with REQUEST_FAILURE, depending on
7141 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7142 ssh2_pkt_send(ssh, pktout);
7146 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7154 struct ssh_channel *c;
7155 unsigned remid, winsize, pktsize;
7156 struct Packet *pktout;
7158 ssh_pkt_getstring(pktin, &type, &typelen);
7159 c = snew(struct ssh_channel);
7162 remid = ssh_pkt_getuint32(pktin);
7163 winsize = ssh_pkt_getuint32(pktin);
7164 pktsize = ssh_pkt_getuint32(pktin);
7166 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7170 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7171 addrstr = snewn(peeraddrlen+1, char);
7172 memcpy(addrstr, peeraddr, peeraddrlen);
7173 addrstr[peeraddrlen] = '\0';
7174 peerport = ssh_pkt_getuint32(pktin);
7176 logeventf(ssh, "Received X11 connect request from %s:%d",
7179 if (!ssh->X11_fwd_enabled)
7180 error = "X11 forwarding is not enabled";
7181 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
7182 addrstr, peerport, &ssh->cfg)) != NULL) {
7183 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7184 error = "Unable to open an X11 connection";
7186 logevent("Opening X11 forward connection succeeded");
7191 } else if (typelen == 15 &&
7192 !memcmp(type, "forwarded-tcpip", 15)) {
7193 struct ssh_rportfwd pf, *realpf;
7196 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7197 pf.sport = ssh_pkt_getuint32(pktin);
7198 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7199 peerport = ssh_pkt_getuint32(pktin);
7200 realpf = find234(ssh->rportfwds, &pf, NULL);
7201 logeventf(ssh, "Received remote port %d open request "
7202 "from %s:%d", pf.sport, peeraddr, peerport);
7203 if (realpf == NULL) {
7204 error = "Remote port is not recognised";
7206 const char *e = pfd_newconnect(&c->u.pfd.s,
7210 realpf->pfrec->addressfamily);
7211 logeventf(ssh, "Attempting to forward remote port to "
7212 "%s:%d", realpf->dhost, realpf->dport);
7214 logeventf(ssh, "Port open failed: %s", e);
7215 error = "Port open failed";
7217 logevent("Forwarded port opened successfully");
7218 c->type = CHAN_SOCKDATA;
7221 } else if (typelen == 22 &&
7222 !memcmp(type, "auth-agent@openssh.com", 22)) {
7223 if (!ssh->agentfwd_enabled)
7224 error = "Agent forwarding is not enabled";
7226 c->type = CHAN_AGENT; /* identify channel type */
7227 c->u.a.lensofar = 0;
7230 error = "Unsupported channel type requested";
7233 c->remoteid = remid;
7234 c->halfopen = FALSE;
7236 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7237 ssh2_pkt_adduint32(pktout, c->remoteid);
7238 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7239 ssh2_pkt_addstring(pktout, error);
7240 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7241 ssh2_pkt_send(ssh, pktout);
7242 logeventf(ssh, "Rejected channel open: %s", error);
7245 ssh2_channel_init(c);
7246 c->v.v2.remwindow = winsize;
7247 c->v.v2.remmaxpkt = pktsize;
7248 add234(ssh->channels, c);
7249 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7250 ssh2_pkt_adduint32(pktout, c->remoteid);
7251 ssh2_pkt_adduint32(pktout, c->localid);
7252 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7253 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7254 ssh2_pkt_send(ssh, pktout);
7259 * Buffer banner messages for later display at some convenient point,
7260 * if we're going to display them.
7262 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7264 /* Arbitrary limit to prevent unbounded inflation of buffer */
7265 if (ssh->cfg.ssh_show_banner &&
7266 bufchain_size(&ssh->banner) <= 131072) {
7267 char *banner = NULL;
7269 ssh_pkt_getstring(pktin, &banner, &size);
7271 bufchain_add(&ssh->banner, banner, size);
7275 /* Helper function to deal with sending tty modes for "pty-req" */
7276 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7278 struct Packet *pktout = (struct Packet *)data;
7280 unsigned int arg = 0;
7281 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7282 if (i == lenof(ssh_ttymodes)) return;
7283 switch (ssh_ttymodes[i].type) {
7285 arg = ssh_tty_parse_specchar(val);
7288 arg = ssh_tty_parse_boolean(val);
7291 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7292 ssh2_pkt_adduint32(pktout, arg);
7296 * Handle the SSH-2 userauth and connection layers.
7298 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7299 struct Packet *pktin)
7301 struct do_ssh2_authconn_state {
7304 AUTH_TYPE_PUBLICKEY,
7305 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7306 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7309 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7310 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7312 int done_service_req;
7313 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7314 int tried_pubkey_config, done_agent;
7319 int kbd_inter_refused;
7320 int we_are_in, userauth_success;
7321 prompts_t *cur_prompt;
7326 void *publickey_blob;
7327 int publickey_bloblen;
7328 int publickey_encrypted;
7329 char *publickey_algorithm;
7330 char *publickey_comment;
7331 unsigned char agent_request[5], *agent_response, *agentp;
7332 int agent_responselen;
7333 unsigned char *pkblob_in_agent;
7335 char *pkblob, *alg, *commentp;
7336 int pklen, alglen, commentlen;
7337 int siglen, retlen, len;
7338 char *q, *agentreq, *ret;
7340 int num_env, env_left, env_ok;
7341 struct Packet *pktout;
7343 struct ssh_gss_library *gsslib;
7344 Ssh_gss_ctx gss_ctx;
7345 Ssh_gss_buf gss_buf;
7346 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7347 Ssh_gss_name gss_srv_name;
7348 Ssh_gss_stat gss_stat;
7351 crState(do_ssh2_authconn_state);
7353 crBegin(ssh->do_ssh2_authconn_crstate);
7355 s->done_service_req = FALSE;
7356 s->we_are_in = s->userauth_success = FALSE;
7358 s->tried_gssapi = FALSE;
7361 if (!ssh->cfg.ssh_no_userauth) {
7363 * Request userauth protocol, and await a response to it.
7365 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7366 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7367 ssh2_pkt_send(ssh, s->pktout);
7368 crWaitUntilV(pktin);
7369 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7370 s->done_service_req = TRUE;
7372 if (!s->done_service_req) {
7374 * Request connection protocol directly, without authentication.
7376 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7377 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7378 ssh2_pkt_send(ssh, s->pktout);
7379 crWaitUntilV(pktin);
7380 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7381 s->we_are_in = TRUE; /* no auth required */
7383 bombout(("Server refused service request"));
7388 /* Arrange to be able to deal with any BANNERs that come in.
7389 * (We do this now as packets may come in during the next bit.) */
7390 bufchain_init(&ssh->banner);
7391 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7392 ssh2_msg_userauth_banner;
7395 * Misc one-time setup for authentication.
7397 s->publickey_blob = NULL;
7398 if (!s->we_are_in) {
7401 * Load the public half of any configured public key file
7404 if (!filename_is_null(ssh->cfg.keyfile)) {
7406 logeventf(ssh, "Reading private key file \"%.150s\"",
7407 filename_to_str(&ssh->cfg.keyfile));
7408 keytype = key_type(&ssh->cfg.keyfile);
7409 if (keytype == SSH_KEYTYPE_SSH2) {
7412 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
7413 &s->publickey_algorithm,
7414 &s->publickey_bloblen,
7415 &s->publickey_comment, &error);
7416 if (s->publickey_blob) {
7417 s->publickey_encrypted =
7418 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
7421 logeventf(ssh, "Unable to load private key (%s)",
7423 msgbuf = dupprintf("Unable to load private key file "
7424 "\"%.150s\" (%s)\r\n",
7425 filename_to_str(&ssh->cfg.keyfile),
7427 c_write_str(ssh, msgbuf);
7432 logeventf(ssh, "Unable to use this key file (%s)",
7433 key_type_to_str(keytype));
7434 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7436 filename_to_str(&ssh->cfg.keyfile),
7437 key_type_to_str(keytype));
7438 c_write_str(ssh, msgbuf);
7440 s->publickey_blob = NULL;
7445 * Find out about any keys Pageant has (but if there's a
7446 * public key configured, filter out all others).
7449 s->agent_response = NULL;
7450 s->pkblob_in_agent = NULL;
7451 if (ssh->cfg.tryagent && agent_exists()) {
7455 logevent("Pageant is running. Requesting keys.");
7457 /* Request the keys held by the agent. */
7458 PUT_32BIT(s->agent_request, 1);
7459 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7460 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7461 ssh_agent_callback, ssh)) {
7465 bombout(("Unexpected data from server while"
7466 " waiting for agent response"));
7469 } while (pktin || inlen > 0);
7470 r = ssh->agent_response;
7471 s->agent_responselen = ssh->agent_response_len;
7473 s->agent_response = (unsigned char *) r;
7474 if (s->agent_response && s->agent_responselen >= 5 &&
7475 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7478 p = s->agent_response + 5;
7479 s->nkeys = GET_32BIT(p);
7481 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
7482 if (s->publickey_blob) {
7483 /* See if configured key is in agent. */
7484 for (keyi = 0; keyi < s->nkeys; keyi++) {
7485 s->pklen = GET_32BIT(p);
7486 if (s->pklen == s->publickey_bloblen &&
7487 !memcmp(p+4, s->publickey_blob,
7488 s->publickey_bloblen)) {
7489 logeventf(ssh, "Pageant key #%d matches "
7490 "configured key file", keyi);
7492 s->pkblob_in_agent = p;
7496 p += GET_32BIT(p) + 4; /* comment */
7498 if (!s->pkblob_in_agent) {
7499 logevent("Configured key file not in Pageant");
7509 * We repeat this whole loop, including the username prompt,
7510 * until we manage a successful authentication. If the user
7511 * types the wrong _password_, they can be sent back to the
7512 * beginning to try another username, if this is configured on.
7513 * (If they specify a username in the config, they are never
7514 * asked, even if they do give a wrong password.)
7516 * I think this best serves the needs of
7518 * - the people who have no configuration, no keys, and just
7519 * want to try repeated (username,password) pairs until they
7520 * type both correctly
7522 * - people who have keys and configuration but occasionally
7523 * need to fall back to passwords
7525 * - people with a key held in Pageant, who might not have
7526 * logged in to a particular machine before; so they want to
7527 * type a username, and then _either_ their key will be
7528 * accepted, _or_ they will type a password. If they mistype
7529 * the username they will want to be able to get back and
7532 s->username[0] = '\0';
7533 s->got_username = FALSE;
7534 while (!s->we_are_in) {
7538 if (s->got_username && !ssh->cfg.change_username) {
7540 * We got a username last time round this loop, and
7541 * with change_username turned off we don't try to get
7544 } else if (!get_remote_username(&ssh->cfg, s->username,
7545 sizeof(s->username))) {
7546 int ret; /* need not be kept over crReturn */
7547 s->cur_prompt = new_prompts(ssh->frontend);
7548 s->cur_prompt->to_server = TRUE;
7549 s->cur_prompt->name = dupstr("SSH login name");
7550 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
7551 lenof(s->username));
7552 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7555 crWaitUntilV(!pktin);
7556 ret = get_userpass_input(s->cur_prompt, in, inlen);
7561 * get_userpass_input() failed to get a username.
7564 free_prompts(s->cur_prompt);
7565 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7568 memcpy(s->username, s->cur_prompt->prompts[0]->result,
7569 lenof(s->username));
7570 free_prompts(s->cur_prompt);
7573 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7574 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
7575 c_write_str(ssh, stuff);
7579 s->got_username = TRUE;
7582 * Send an authentication request using method "none": (a)
7583 * just in case it succeeds, and (b) so that we know what
7584 * authentication methods we can usefully try next.
7586 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7588 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7589 ssh2_pkt_addstring(s->pktout, s->username);
7590 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7591 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7592 ssh2_pkt_send(ssh, s->pktout);
7593 s->type = AUTH_TYPE_NONE;
7595 s->we_are_in = FALSE;
7597 s->tried_pubkey_config = FALSE;
7598 s->kbd_inter_refused = FALSE;
7600 /* Reset agent request state. */
7601 s->done_agent = FALSE;
7602 if (s->agent_response) {
7603 if (s->pkblob_in_agent) {
7604 s->agentp = s->pkblob_in_agent;
7606 s->agentp = s->agent_response + 5 + 4;
7612 char *methods = NULL;
7616 * Wait for the result of the last authentication request.
7619 crWaitUntilV(pktin);
7621 * Now is a convenient point to spew any banner material
7622 * that we've accumulated. (This should ensure that when
7623 * we exit the auth loop, we haven't any left to deal
7627 int size = bufchain_size(&ssh->banner);
7629 * Don't show the banner if we're operating in
7630 * non-verbose non-interactive mode. (It's probably
7631 * a script, which means nobody will read the
7632 * banner _anyway_, and moreover the printing of
7633 * the banner will screw up processing on the
7634 * output of (say) plink.)
7636 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7637 char *banner = snewn(size, char);
7638 bufchain_fetch(&ssh->banner, banner, size);
7639 c_write_untrusted(ssh, banner, size);
7642 bufchain_clear(&ssh->banner);
7644 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
7645 logevent("Access granted");
7646 s->we_are_in = s->userauth_success = TRUE;
7650 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
7651 bombout(("Strange packet received during authentication: "
7652 "type %d", pktin->type));
7659 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7660 * we can look at the string in it and know what we can
7661 * helpfully try next.
7663 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
7664 ssh_pkt_getstring(pktin, &methods, &methlen);
7665 if (!ssh2_pkt_getbool(pktin)) {
7667 * We have received an unequivocal Access
7668 * Denied. This can translate to a variety of
7671 * - if we'd just tried "none" authentication,
7672 * it's not worth printing anything at all
7674 * - if we'd just tried a public key _offer_,
7675 * the message should be "Server refused our
7676 * key" (or no message at all if the key
7677 * came from Pageant)
7679 * - if we'd just tried anything else, the
7680 * message really should be "Access denied".
7682 * Additionally, if we'd just tried password
7683 * authentication, we should break out of this
7684 * whole loop so as to go back to the username
7685 * prompt (iff we're configured to allow
7686 * username change attempts).
7688 if (s->type == AUTH_TYPE_NONE) {
7690 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7691 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7692 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7693 c_write_str(ssh, "Server refused our key\r\n");
7694 logevent("Server refused public key");
7695 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
7696 /* server declined keyboard-interactive; ignore */
7698 c_write_str(ssh, "Access denied\r\n");
7699 logevent("Access denied");
7700 if (s->type == AUTH_TYPE_PASSWORD &&
7701 ssh->cfg.change_username) {
7702 /* XXX perhaps we should allow
7703 * keyboard-interactive to do this too? */
7704 s->we_are_in = FALSE;
7709 c_write_str(ssh, "Further authentication required\r\n");
7710 logevent("Further authentication required");
7714 in_commasep_string("publickey", methods, methlen);
7716 in_commasep_string("password", methods, methlen);
7717 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
7718 in_commasep_string("keyboard-interactive", methods, methlen);
7721 ssh->gsslibs = ssh_gss_setup(&ssh->cfg);
7722 s->can_gssapi = ssh->cfg.try_gssapi_auth &&
7723 in_commasep_string("gssapi-with-mic", methods, methlen) &&
7724 ssh->gsslibs->nlibraries > 0;
7728 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7730 if (s->can_pubkey && !s->done_agent && s->nkeys) {
7733 * Attempt public-key authentication using a key from Pageant.
7736 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7738 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7740 /* Unpack key from agent response */
7741 s->pklen = GET_32BIT(s->agentp);
7743 s->pkblob = (char *)s->agentp;
7744 s->agentp += s->pklen;
7745 s->alglen = GET_32BIT(s->pkblob);
7746 s->alg = s->pkblob + 4;
7747 s->commentlen = GET_32BIT(s->agentp);
7749 s->commentp = (char *)s->agentp;
7750 s->agentp += s->commentlen;
7751 /* s->agentp now points at next key, if any */
7753 /* See if server will accept it */
7754 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7755 ssh2_pkt_addstring(s->pktout, s->username);
7756 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7757 /* service requested */
7758 ssh2_pkt_addstring(s->pktout, "publickey");
7760 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7761 ssh2_pkt_addstring_start(s->pktout);
7762 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7763 ssh2_pkt_addstring_start(s->pktout);
7764 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7765 ssh2_pkt_send(ssh, s->pktout);
7766 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
7768 crWaitUntilV(pktin);
7769 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7771 /* Offer of key refused. */
7778 if (flags & FLAG_VERBOSE) {
7779 c_write_str(ssh, "Authenticating with "
7781 c_write(ssh, s->commentp, s->commentlen);
7782 c_write_str(ssh, "\" from agent\r\n");
7786 * Server is willing to accept the key.
7787 * Construct a SIGN_REQUEST.
7789 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7790 ssh2_pkt_addstring(s->pktout, s->username);
7791 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7792 /* service requested */
7793 ssh2_pkt_addstring(s->pktout, "publickey");
7795 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7796 ssh2_pkt_addstring_start(s->pktout);
7797 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7798 ssh2_pkt_addstring_start(s->pktout);
7799 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7801 /* Ask agent for signature. */
7802 s->siglen = s->pktout->length - 5 + 4 +
7803 ssh->v2_session_id_len;
7804 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7806 s->len = 1; /* message type */
7807 s->len += 4 + s->pklen; /* key blob */
7808 s->len += 4 + s->siglen; /* data to sign */
7809 s->len += 4; /* flags */
7810 s->agentreq = snewn(4 + s->len, char);
7811 PUT_32BIT(s->agentreq, s->len);
7812 s->q = s->agentreq + 4;
7813 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
7814 PUT_32BIT(s->q, s->pklen);
7816 memcpy(s->q, s->pkblob, s->pklen);
7818 PUT_32BIT(s->q, s->siglen);
7820 /* Now the data to be signed... */
7821 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7822 PUT_32BIT(s->q, ssh->v2_session_id_len);
7825 memcpy(s->q, ssh->v2_session_id,
7826 ssh->v2_session_id_len);
7827 s->q += ssh->v2_session_id_len;
7828 memcpy(s->q, s->pktout->data + 5,
7829 s->pktout->length - 5);
7830 s->q += s->pktout->length - 5;
7831 /* And finally the (zero) flags word. */
7833 if (!agent_query(s->agentreq, s->len + 4,
7835 ssh_agent_callback, ssh)) {
7839 bombout(("Unexpected data from server"
7840 " while waiting for agent"
7844 } while (pktin || inlen > 0);
7845 vret = ssh->agent_response;
7846 s->retlen = ssh->agent_response_len;
7851 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7852 logevent("Sending Pageant's response");
7853 ssh2_add_sigblob(ssh, s->pktout,
7854 s->pkblob, s->pklen,
7856 GET_32BIT(s->ret + 5));
7857 ssh2_pkt_send(ssh, s->pktout);
7858 s->type = AUTH_TYPE_PUBLICKEY;
7860 /* FIXME: less drastic response */
7861 bombout(("Pageant failed to answer challenge"));
7867 /* Do we have any keys left to try? */
7868 if (s->pkblob_in_agent) {
7869 s->done_agent = TRUE;
7870 s->tried_pubkey_config = TRUE;
7873 if (s->keyi >= s->nkeys)
7874 s->done_agent = TRUE;
7877 } else if (s->can_pubkey && s->publickey_blob &&
7878 !s->tried_pubkey_config) {
7880 struct ssh2_userkey *key; /* not live over crReturn */
7881 char *passphrase; /* not live over crReturn */
7883 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7885 s->tried_pubkey_config = TRUE;
7888 * Try the public key supplied in the configuration.
7890 * First, offer the public blob to see if the server is
7891 * willing to accept it.
7893 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7894 ssh2_pkt_addstring(s->pktout, s->username);
7895 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7896 /* service requested */
7897 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7898 ssh2_pkt_addbool(s->pktout, FALSE);
7899 /* no signature included */
7900 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7901 ssh2_pkt_addstring_start(s->pktout);
7902 ssh2_pkt_addstring_data(s->pktout,
7903 (char *)s->publickey_blob,
7904 s->publickey_bloblen);
7905 ssh2_pkt_send(ssh, s->pktout);
7906 logevent("Offered public key");
7908 crWaitUntilV(pktin);
7909 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7910 /* Key refused. Give up. */
7911 s->gotit = TRUE; /* reconsider message next loop */
7912 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7913 continue; /* process this new message */
7915 logevent("Offer of public key accepted");
7918 * Actually attempt a serious authentication using
7921 if (flags & FLAG_VERBOSE) {
7922 c_write_str(ssh, "Authenticating with public key \"");
7923 c_write_str(ssh, s->publickey_comment);
7924 c_write_str(ssh, "\"\r\n");
7928 const char *error; /* not live over crReturn */
7929 if (s->publickey_encrypted) {
7931 * Get a passphrase from the user.
7933 int ret; /* need not be kept over crReturn */
7934 s->cur_prompt = new_prompts(ssh->frontend);
7935 s->cur_prompt->to_server = FALSE;
7936 s->cur_prompt->name = dupstr("SSH key passphrase");
7937 add_prompt(s->cur_prompt,
7938 dupprintf("Passphrase for key \"%.100s\": ",
7939 s->publickey_comment),
7940 FALSE, SSH_MAX_PASSWORD_LEN);
7941 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7944 crWaitUntilV(!pktin);
7945 ret = get_userpass_input(s->cur_prompt,
7950 /* Failed to get a passphrase. Terminate. */
7951 free_prompts(s->cur_prompt);
7952 ssh_disconnect(ssh, NULL,
7953 "Unable to authenticate",
7954 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7959 dupstr(s->cur_prompt->prompts[0]->result);
7960 free_prompts(s->cur_prompt);
7962 passphrase = NULL; /* no passphrase needed */
7966 * Try decrypting the key.
7968 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7971 /* burn the evidence */
7972 memset(passphrase, 0, strlen(passphrase));
7975 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7977 (key == SSH2_WRONG_PASSPHRASE)) {
7978 c_write_str(ssh, "Wrong passphrase\r\n");
7980 /* and loop again */
7982 c_write_str(ssh, "Unable to load private key (");
7983 c_write_str(ssh, error);
7984 c_write_str(ssh, ")\r\n");
7986 break; /* try something else */
7992 unsigned char *pkblob, *sigblob, *sigdata;
7993 int pkblob_len, sigblob_len, sigdata_len;
7997 * We have loaded the private key and the server
7998 * has announced that it's willing to accept it.
7999 * Hallelujah. Generate a signature and send it.
8001 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8002 ssh2_pkt_addstring(s->pktout, s->username);
8003 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8004 /* service requested */
8005 ssh2_pkt_addstring(s->pktout, "publickey");
8007 ssh2_pkt_addbool(s->pktout, TRUE);
8008 /* signature follows */
8009 ssh2_pkt_addstring(s->pktout, key->alg->name);
8010 pkblob = key->alg->public_blob(key->data,
8012 ssh2_pkt_addstring_start(s->pktout);
8013 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8017 * The data to be signed is:
8021 * followed by everything so far placed in the
8024 sigdata_len = s->pktout->length - 5 + 4 +
8025 ssh->v2_session_id_len;
8026 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8028 sigdata = snewn(sigdata_len, unsigned char);
8030 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8031 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8034 memcpy(sigdata+p, ssh->v2_session_id,
8035 ssh->v2_session_id_len);
8036 p += ssh->v2_session_id_len;
8037 memcpy(sigdata+p, s->pktout->data + 5,
8038 s->pktout->length - 5);
8039 p += s->pktout->length - 5;
8040 assert(p == sigdata_len);
8041 sigblob = key->alg->sign(key->data, (char *)sigdata,
8042 sigdata_len, &sigblob_len);
8043 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
8044 sigblob, sigblob_len);
8049 ssh2_pkt_send(ssh, s->pktout);
8050 s->type = AUTH_TYPE_PUBLICKEY;
8051 key->alg->freekey(key->data);
8055 } else if (s->can_gssapi && !s->tried_gssapi) {
8057 /* GSSAPI Authentication */
8062 s->type = AUTH_TYPE_GSSAPI;
8063 s->tried_gssapi = TRUE;
8065 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8068 * Pick the highest GSS library on the preference
8074 for (i = 0; i < ngsslibs; i++) {
8075 int want_id = ssh->cfg.ssh_gsslist[i];
8076 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8077 if (ssh->gsslibs->libraries[j].id == want_id) {
8078 s->gsslib = &ssh->gsslibs->libraries[j];
8079 goto got_gsslib; /* double break */
8084 * We always expect to have found something in
8085 * the above loop: we only came here if there
8086 * was at least one viable GSS library, and the
8087 * preference list should always mention
8088 * everything and only change the order.
8093 if (s->gsslib->gsslogmsg)
8094 logevent(s->gsslib->gsslogmsg);
8096 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8097 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8098 ssh2_pkt_addstring(s->pktout, s->username);
8099 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8100 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8102 /* add mechanism info */
8103 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8105 /* number of GSSAPI mechanisms */
8106 ssh2_pkt_adduint32(s->pktout,1);
8108 /* length of OID + 2 */
8109 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8110 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8113 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8115 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8117 ssh2_pkt_send(ssh, s->pktout);
8118 crWaitUntilV(pktin);
8119 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8120 logevent("GSSAPI authentication request refused");
8124 /* check returned packet ... */
8126 ssh_pkt_getstring(pktin, &data, &len);
8127 s->gss_rcvtok.value = data;
8128 s->gss_rcvtok.length = len;
8129 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8130 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8131 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8132 memcmp((char *)s->gss_rcvtok.value + 2,
8133 s->gss_buf.value,s->gss_buf.length) ) {
8134 logevent("GSSAPI authentication - wrong response from server");
8138 /* now start running */
8139 s->gss_stat = s->gsslib->import_name(s->gsslib,
8142 if (s->gss_stat != SSH_GSS_OK) {
8143 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8144 logevent("GSSAPI import name failed - Bad service name");
8146 logevent("GSSAPI import name failed");
8150 /* fetch TGT into GSS engine */
8151 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8153 if (s->gss_stat != SSH_GSS_OK) {
8154 logevent("GSSAPI authentication failed to get credentials");
8155 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8159 /* initial tokens are empty */
8160 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8161 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8163 /* now enter the loop */
8165 s->gss_stat = s->gsslib->init_sec_context
8173 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8174 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8175 logevent("GSSAPI authentication initialisation failed");
8177 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8178 &s->gss_buf) == SSH_GSS_OK) {
8179 logevent(s->gss_buf.value);
8180 sfree(s->gss_buf.value);
8185 logevent("GSSAPI authentication initialised");
8187 /* Client and server now exchange tokens until GSSAPI
8188 * no longer says CONTINUE_NEEDED */
8190 if (s->gss_sndtok.length != 0) {
8191 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8192 ssh_pkt_addstring_start(s->pktout);
8193 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8194 ssh2_pkt_send(ssh, s->pktout);
8195 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8198 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8199 crWaitUntilV(pktin);
8200 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8201 logevent("GSSAPI authentication - bad server response");
8202 s->gss_stat = SSH_GSS_FAILURE;
8205 ssh_pkt_getstring(pktin, &data, &len);
8206 s->gss_rcvtok.value = data;
8207 s->gss_rcvtok.length = len;
8209 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8211 if (s->gss_stat != SSH_GSS_OK) {
8212 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8213 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8216 logevent("GSSAPI authentication loop finished OK");
8218 /* Now send the MIC */
8220 s->pktout = ssh2_pkt_init(0);
8221 micoffset = s->pktout->length;
8222 ssh_pkt_addstring_start(s->pktout);
8223 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8224 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8225 ssh_pkt_addstring(s->pktout, s->username);
8226 ssh_pkt_addstring(s->pktout, "ssh-connection");
8227 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8229 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8230 s->gss_buf.length = s->pktout->length - micoffset;
8232 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8233 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8234 ssh_pkt_addstring_start(s->pktout);
8235 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8236 ssh2_pkt_send(ssh, s->pktout);
8237 s->gsslib->free_mic(s->gsslib, &mic);
8241 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8242 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8245 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8248 * Keyboard-interactive authentication.
8251 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8253 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8255 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8256 ssh2_pkt_addstring(s->pktout, s->username);
8257 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8258 /* service requested */
8259 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8261 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8262 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8263 ssh2_pkt_send(ssh, s->pktout);
8265 crWaitUntilV(pktin);
8266 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8267 /* Server is not willing to do keyboard-interactive
8268 * at all (or, bizarrely but legally, accepts the
8269 * user without actually issuing any prompts).
8270 * Give up on it entirely. */
8272 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
8273 logevent("Keyboard-interactive authentication refused");
8274 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8275 s->kbd_inter_refused = TRUE; /* don't try it again */
8280 * Loop while the server continues to send INFO_REQUESTs.
8282 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8284 char *name, *inst, *lang;
8285 int name_len, inst_len, lang_len;
8289 * We've got a fresh USERAUTH_INFO_REQUEST.
8290 * Get the preamble and start building a prompt.
8292 ssh_pkt_getstring(pktin, &name, &name_len);
8293 ssh_pkt_getstring(pktin, &inst, &inst_len);
8294 ssh_pkt_getstring(pktin, &lang, &lang_len);
8295 s->cur_prompt = new_prompts(ssh->frontend);
8296 s->cur_prompt->to_server = TRUE;
8299 * Get any prompt(s) from the packet.
8301 s->num_prompts = ssh_pkt_getuint32(pktin);
8302 for (i = 0; i < s->num_prompts; i++) {
8306 static char noprompt[] =
8307 "<server failed to send prompt>: ";
8309 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8310 echo = ssh2_pkt_getbool(pktin);
8313 prompt_len = lenof(noprompt)-1;
8315 add_prompt(s->cur_prompt,
8316 dupprintf("%.*s", prompt_len, prompt),
8317 echo, SSH_MAX_PASSWORD_LEN);
8321 /* FIXME: better prefix to distinguish from
8323 s->cur_prompt->name =
8324 dupprintf("SSH server: %.*s", name_len, name);
8325 s->cur_prompt->name_reqd = TRUE;
8327 s->cur_prompt->name =
8328 dupstr("SSH server authentication");
8329 s->cur_prompt->name_reqd = FALSE;
8331 /* We add a prefix to try to make it clear that a prompt
8332 * has come from the server.
8333 * FIXME: ugly to print "Using..." in prompt _every_
8334 * time round. Can this be done more subtly? */
8335 /* Special case: for reasons best known to themselves,
8336 * some servers send k-i requests with no prompts and
8337 * nothing to display. Keep quiet in this case. */
8338 if (s->num_prompts || name_len || inst_len) {
8339 s->cur_prompt->instruction =
8340 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8341 inst_len ? "\n" : "", inst_len, inst);
8342 s->cur_prompt->instr_reqd = TRUE;
8344 s->cur_prompt->instr_reqd = FALSE;
8348 * Display any instructions, and get the user's
8352 int ret; /* not live over crReturn */
8353 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8356 crWaitUntilV(!pktin);
8357 ret = get_userpass_input(s->cur_prompt, in, inlen);
8362 * Failed to get responses. Terminate.
8364 free_prompts(s->cur_prompt);
8365 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8366 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8373 * Send the response(s) to the server.
8375 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
8376 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8377 for (i=0; i < s->num_prompts; i++) {
8378 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8379 ssh2_pkt_addstring(s->pktout,
8380 s->cur_prompt->prompts[i]->result);
8381 end_log_omission(ssh, s->pktout);
8383 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8386 * Get the next packet in case it's another
8389 crWaitUntilV(pktin);
8394 * We should have SUCCESS or FAILURE now.
8398 } else if (s->can_passwd) {
8401 * Plain old password authentication.
8403 int ret; /* not live over crReturn */
8404 int changereq_first_time; /* not live over crReturn */
8406 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
8408 s->cur_prompt = new_prompts(ssh->frontend);
8409 s->cur_prompt->to_server = TRUE;
8410 s->cur_prompt->name = dupstr("SSH password");
8411 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
8414 FALSE, SSH_MAX_PASSWORD_LEN);
8416 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8419 crWaitUntilV(!pktin);
8420 ret = get_userpass_input(s->cur_prompt, in, inlen);
8425 * Failed to get responses. Terminate.
8427 free_prompts(s->cur_prompt);
8428 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8429 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8434 * Squirrel away the password. (We may need it later if
8435 * asked to change it.)
8437 s->password = dupstr(s->cur_prompt->prompts[0]->result);
8438 free_prompts(s->cur_prompt);
8441 * Send the password packet.
8443 * We pad out the password packet to 256 bytes to make
8444 * it harder for an attacker to find the length of the
8447 * Anyone using a password longer than 256 bytes
8448 * probably doesn't have much to worry about from
8449 * people who find out how long their password is!
8451 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8452 ssh2_pkt_addstring(s->pktout, s->username);
8453 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8454 /* service requested */
8455 ssh2_pkt_addstring(s->pktout, "password");
8456 ssh2_pkt_addbool(s->pktout, FALSE);
8457 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8458 ssh2_pkt_addstring(s->pktout, s->password);
8459 end_log_omission(ssh, s->pktout);
8460 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8461 logevent("Sent password");
8462 s->type = AUTH_TYPE_PASSWORD;
8465 * Wait for next packet, in case it's a password change
8468 crWaitUntilV(pktin);
8469 changereq_first_time = TRUE;
8471 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
8474 * We're being asked for a new password
8475 * (perhaps not for the first time).
8476 * Loop until the server accepts it.
8479 int got_new = FALSE; /* not live over crReturn */
8480 char *prompt; /* not live over crReturn */
8481 int prompt_len; /* not live over crReturn */
8485 if (changereq_first_time)
8486 msg = "Server requested password change";
8488 msg = "Server rejected new password";
8490 c_write_str(ssh, msg);
8491 c_write_str(ssh, "\r\n");
8494 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8496 s->cur_prompt = new_prompts(ssh->frontend);
8497 s->cur_prompt->to_server = TRUE;
8498 s->cur_prompt->name = dupstr("New SSH password");
8499 s->cur_prompt->instruction =
8500 dupprintf("%.*s", prompt_len, prompt);
8501 s->cur_prompt->instr_reqd = TRUE;
8503 * There's no explicit requirement in the protocol
8504 * for the "old" passwords in the original and
8505 * password-change messages to be the same, and
8506 * apparently some Cisco kit supports password change
8507 * by the user entering a blank password originally
8508 * and the real password subsequently, so,
8509 * reluctantly, we prompt for the old password again.
8511 * (On the other hand, some servers don't even bother
8512 * to check this field.)
8514 add_prompt(s->cur_prompt,
8515 dupstr("Current password (blank for previously entered password): "),
8516 FALSE, SSH_MAX_PASSWORD_LEN);
8517 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
8518 FALSE, SSH_MAX_PASSWORD_LEN);
8519 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
8520 FALSE, SSH_MAX_PASSWORD_LEN);
8523 * Loop until the user manages to enter the same
8528 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8531 crWaitUntilV(!pktin);
8532 ret = get_userpass_input(s->cur_prompt, in, inlen);
8537 * Failed to get responses. Terminate.
8539 /* burn the evidence */
8540 free_prompts(s->cur_prompt);
8541 memset(s->password, 0, strlen(s->password));
8543 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8544 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8550 * If the user specified a new original password
8551 * (IYSWIM), overwrite any previously specified
8553 * (A side effect is that the user doesn't have to
8554 * re-enter it if they louse up the new password.)
8556 if (s->cur_prompt->prompts[0]->result[0]) {
8557 memset(s->password, 0, strlen(s->password));
8558 /* burn the evidence */
8561 dupstr(s->cur_prompt->prompts[0]->result);
8565 * Check the two new passwords match.
8567 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
8568 s->cur_prompt->prompts[2]->result)
8571 /* They don't. Silly user. */
8572 c_write_str(ssh, "Passwords do not match\r\n");
8577 * Send the new password (along with the old one).
8578 * (see above for padding rationale)
8580 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8581 ssh2_pkt_addstring(s->pktout, s->username);
8582 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8583 /* service requested */
8584 ssh2_pkt_addstring(s->pktout, "password");
8585 ssh2_pkt_addbool(s->pktout, TRUE);
8586 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8587 ssh2_pkt_addstring(s->pktout, s->password);
8588 ssh2_pkt_addstring(s->pktout,
8589 s->cur_prompt->prompts[1]->result);
8590 free_prompts(s->cur_prompt);
8591 end_log_omission(ssh, s->pktout);
8592 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8593 logevent("Sent new password");
8596 * Now see what the server has to say about it.
8597 * (If it's CHANGEREQ again, it's not happy with the
8600 crWaitUntilV(pktin);
8601 changereq_first_time = FALSE;
8606 * We need to reexamine the current pktin at the top
8607 * of the loop. Either:
8608 * - we weren't asked to change password at all, in
8609 * which case it's a SUCCESS or FAILURE with the
8611 * - we sent a new password, and the server was
8612 * either OK with it (SUCCESS or FAILURE w/partial
8613 * success) or unhappy with the _old_ password
8614 * (FAILURE w/o partial success)
8615 * In any of these cases, we go back to the top of
8616 * the loop and start again.
8621 * We don't need the old password any more, in any
8622 * case. Burn the evidence.
8624 memset(s->password, 0, strlen(s->password));
8628 char *str = dupprintf("No supported authentication methods available"
8629 " (server sent: %.*s)",
8632 ssh_disconnect(ssh, str,
8633 "No supported authentication methods available",
8634 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
8644 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8646 /* Clear up various bits and pieces from authentication. */
8647 if (s->publickey_blob) {
8648 sfree(s->publickey_blob);
8649 sfree(s->publickey_comment);
8651 if (s->agent_response)
8652 sfree(s->agent_response);
8654 if (s->userauth_success) {
8656 * We've just received USERAUTH_SUCCESS, and we haven't sent any
8657 * packets since. Signal the transport layer to consider enacting
8658 * delayed compression.
8660 * (Relying on we_are_in is not sufficient, as
8661 * draft-miller-secsh-compression-delayed is quite clear that it
8662 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
8663 * become set for other reasons.)
8665 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
8669 * Now the connection protocol has started, one way or another.
8672 ssh->channels = newtree234(ssh_channelcmp);
8675 * Set up handlers for some connection protocol messages, so we
8676 * don't have to handle them repeatedly in this coroutine.
8678 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
8679 ssh2_msg_channel_window_adjust;
8680 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
8681 ssh2_msg_global_request;
8684 * Create the main session channel.
8686 if (ssh->cfg.ssh_no_shell) {
8687 ssh->mainchan = NULL;
8688 } else if (*ssh->cfg.ssh_nc_host) {
8690 * Just start a direct-tcpip channel and use it as the main
8693 ssh->mainchan = snew(struct ssh_channel);
8694 ssh->mainchan->ssh = ssh;
8695 ssh2_channel_init(ssh->mainchan);
8697 "Opening direct-tcpip channel to %s:%d in place of session",
8698 ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
8699 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8700 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
8701 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8702 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8703 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8704 ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
8705 ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
8707 * There's nothing meaningful to put in the originator
8708 * fields, but some servers insist on syntactically correct
8711 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
8712 ssh2_pkt_adduint32(s->pktout, 0);
8713 ssh2_pkt_send(ssh, s->pktout);
8715 crWaitUntilV(pktin);
8716 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8717 bombout(("Server refused to open a direct-tcpip channel"));
8719 /* FIXME: error data comes back in FAILURE packet */
8721 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8722 bombout(("Server's channel confirmation cited wrong channel"));
8725 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8726 ssh->mainchan->halfopen = FALSE;
8727 ssh->mainchan->type = CHAN_MAINSESSION;
8728 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8729 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8730 add234(ssh->channels, ssh->mainchan);
8731 update_specials_menu(ssh->frontend);
8732 logevent("Opened direct-tcpip channel");
8735 ssh->mainchan = snew(struct ssh_channel);
8736 ssh->mainchan->ssh = ssh;
8737 ssh2_channel_init(ssh->mainchan);
8738 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8739 ssh2_pkt_addstring(s->pktout, "session");
8740 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8741 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8742 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8743 ssh2_pkt_send(ssh, s->pktout);
8744 crWaitUntilV(pktin);
8745 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8746 bombout(("Server refused to open a session"));
8748 /* FIXME: error data comes back in FAILURE packet */
8750 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8751 bombout(("Server's channel confirmation cited wrong channel"));
8754 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8755 ssh->mainchan->halfopen = FALSE;
8756 ssh->mainchan->type = CHAN_MAINSESSION;
8757 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8758 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8759 add234(ssh->channels, ssh->mainchan);
8760 update_specials_menu(ssh->frontend);
8761 logevent("Opened channel for session");
8762 ssh->ncmode = FALSE;
8766 * Now we have a channel, make dispatch table entries for
8767 * general channel-based messages.
8769 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8770 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8771 ssh2_msg_channel_data;
8772 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8773 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8774 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8775 ssh2_msg_channel_open_confirmation;
8776 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8777 ssh2_msg_channel_open_failure;
8778 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8779 ssh2_msg_channel_request;
8780 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8781 ssh2_msg_channel_open;
8783 if (ssh->mainchan && ssh->cfg.ssh_simple) {
8785 * This message indicates to the server that we promise
8786 * not to try to run any other channel in parallel with
8787 * this one, so it's safe for it to advertise a very large
8788 * window and leave the flow control to TCP.
8790 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8791 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8792 ssh2_pkt_addstring(s->pktout, "simple@putty.projects.tartarus.org");
8793 ssh2_pkt_addbool(s->pktout, 0); /* no reply */
8794 ssh2_pkt_send(ssh, s->pktout);
8798 * Potentially enable X11 forwarding.
8800 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward &&
8801 (ssh->x11disp = x11_setup_display(ssh->cfg.x11_display,
8802 ssh->cfg.x11_auth, &ssh->cfg))) {
8803 logevent("Requesting X11 forwarding");
8804 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8805 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8806 ssh2_pkt_addstring(s->pktout, "x11-req");
8807 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8808 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8809 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthprotoname);
8811 * Note that while we blank the X authentication data here, we don't
8812 * take any special action to blank the start of an X11 channel,
8813 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
8814 * without having session blanking enabled is likely to leak your
8815 * cookie into the log.
8817 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8818 ssh2_pkt_addstring(s->pktout, ssh->x11disp->remoteauthdatastring);
8819 end_log_omission(ssh, s->pktout);
8820 ssh2_pkt_adduint32(s->pktout, ssh->x11disp->screennum);
8821 ssh2_pkt_send(ssh, s->pktout);
8823 crWaitUntilV(pktin);
8825 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8826 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8827 bombout(("Unexpected response to X11 forwarding request:"
8828 " packet type %d", pktin->type));
8831 logevent("X11 forwarding refused");
8833 logevent("X11 forwarding enabled");
8834 ssh->X11_fwd_enabled = TRUE;
8839 * Enable port forwardings.
8841 ssh_setup_portfwd(ssh, &ssh->cfg);
8844 * Potentially enable agent forwarding.
8846 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
8847 logevent("Requesting OpenSSH-style agent forwarding");
8848 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8849 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8850 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
8851 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8852 ssh2_pkt_send(ssh, s->pktout);
8854 crWaitUntilV(pktin);
8856 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8857 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8858 bombout(("Unexpected response to agent forwarding request:"
8859 " packet type %d", pktin->type));
8862 logevent("Agent forwarding refused");
8864 logevent("Agent forwarding enabled");
8865 ssh->agentfwd_enabled = TRUE;
8870 * Now allocate a pty for the session.
8872 if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
8873 /* Unpick the terminal-speed string. */
8874 /* XXX perhaps we should allow no speeds to be sent. */
8875 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8876 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
8877 /* Build the pty request. */
8878 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8879 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8880 ssh2_pkt_addstring(s->pktout, "pty-req");
8881 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8882 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
8883 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
8884 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
8885 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
8886 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
8887 ssh2_pkt_addstring_start(s->pktout);
8888 parse_ttymodes(ssh, ssh->cfg.ttymodes,
8889 ssh2_send_ttymode, (void *)s->pktout);
8890 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
8891 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
8892 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
8893 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
8894 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
8895 ssh2_pkt_send(ssh, s->pktout);
8896 ssh->state = SSH_STATE_INTERMED;
8898 crWaitUntilV(pktin);
8900 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8901 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8902 bombout(("Unexpected response to pty request:"
8903 " packet type %d", pktin->type));
8906 c_write_str(ssh, "Server refused to allocate pty\r\n");
8907 ssh->editing = ssh->echoing = 1;
8909 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8910 ssh->ospeed, ssh->ispeed);
8913 ssh->editing = ssh->echoing = 1;
8917 * Send environment variables.
8919 * Simplest thing here is to send all the requests at once, and
8920 * then wait for a whole bunch of successes or failures.
8922 if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
8923 char *e = ssh->cfg.environmt;
8924 char *var, *varend, *val;
8930 while (*e && *e != '\t') e++;
8932 if (*e == '\t') e++;
8937 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8938 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8939 ssh2_pkt_addstring(s->pktout, "env");
8940 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8941 ssh2_pkt_addstring_start(s->pktout);
8942 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
8943 ssh2_pkt_addstring(s->pktout, val);
8944 ssh2_pkt_send(ssh, s->pktout);
8949 logeventf(ssh, "Sent %d environment variables", s->num_env);
8952 s->env_left = s->num_env;
8954 while (s->env_left > 0) {
8955 crWaitUntilV(pktin);
8957 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8958 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8959 bombout(("Unexpected response to environment request:"
8960 " packet type %d", pktin->type));
8970 if (s->env_ok == s->num_env) {
8971 logevent("All environment variables successfully set");
8972 } else if (s->env_ok == 0) {
8973 logevent("All environment variables refused");
8974 c_write_str(ssh, "Server refused to set environment variables\r\n");
8976 logeventf(ssh, "%d environment variables refused",
8977 s->num_env - s->env_ok);
8978 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8983 * Start a shell or a remote command. We may have to attempt
8984 * this twice if the config data has provided a second choice
8987 if (ssh->mainchan && !ssh->ncmode) while (1) {
8991 if (ssh->fallback_cmd) {
8992 subsys = ssh->cfg.ssh_subsys2;
8993 cmd = ssh->cfg.remote_cmd_ptr2;
8995 subsys = ssh->cfg.ssh_subsys;
8996 cmd = ssh->cfg.remote_cmd_ptr;
8997 if (!cmd) cmd = ssh->cfg.remote_cmd;
9000 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9001 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
9003 ssh2_pkt_addstring(s->pktout, "subsystem");
9004 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9005 ssh2_pkt_addstring(s->pktout, cmd);
9007 ssh2_pkt_addstring(s->pktout, "exec");
9008 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9009 ssh2_pkt_addstring(s->pktout, cmd);
9011 ssh2_pkt_addstring(s->pktout, "shell");
9012 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
9014 ssh2_pkt_send(ssh, s->pktout);
9016 crWaitUntilV(pktin);
9018 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9019 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9020 bombout(("Unexpected response to shell/command request:"
9021 " packet type %d", pktin->type));
9025 * We failed to start the command. If this is the
9026 * fallback command, we really are finished; if it's
9027 * not, and if the fallback command exists, try falling
9028 * back to it before complaining.
9030 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
9031 logevent("Primary command failed; attempting fallback");
9032 ssh->fallback_cmd = TRUE;
9035 bombout(("Server refused to start a shell/command"));
9038 logevent("Started a shell/command");
9043 ssh->state = SSH_STATE_SESSION;
9044 if (ssh->size_needed)
9045 ssh_size(ssh, ssh->term_width, ssh->term_height);
9046 if (ssh->eof_needed)
9047 ssh_special(ssh, TS_EOF);
9050 * All the initial channel requests are done, so install the default
9053 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_success;
9054 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_failure;
9060 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
9065 s->try_send = FALSE;
9069 * _All_ the connection-layer packets we expect to
9070 * receive are now handled by the dispatch table.
9071 * Anything that reaches here must be bogus.
9074 bombout(("Strange packet received: type %d", pktin->type));
9076 } else if (ssh->mainchan) {
9078 * We have spare data. Add it to the channel buffer.
9080 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9085 struct ssh_channel *c;
9087 * Try to send data on all channels if we can.
9089 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9090 ssh2_try_send_and_unthrottle(ssh, c);
9098 * Handlers for SSH-2 messages that might arrive at any moment.
9100 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9102 /* log reason code in disconnect message */
9106 reason = ssh_pkt_getuint32(pktin);
9107 ssh_pkt_getstring(pktin, &msg, &msglen);
9109 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9110 buf = dupprintf("Received disconnect message (%s)",
9111 ssh2_disconnect_reasons[reason]);
9113 buf = dupprintf("Received disconnect message (unknown"
9114 " type %d)", reason);
9118 buf = dupprintf("Disconnection message text: %.*s",
9121 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9123 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9124 ssh2_disconnect_reasons[reason] : "unknown",
9129 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9131 /* log the debug message */
9135 /* XXX maybe we should actually take notice of the return value */
9136 ssh2_pkt_getbool(pktin);
9137 ssh_pkt_getstring(pktin, &msg, &msglen);
9139 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9142 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9144 struct Packet *pktout;
9145 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9146 ssh2_pkt_adduint32(pktout, pktin->sequence);
9148 * UNIMPLEMENTED messages MUST appear in the same order as the
9149 * messages they respond to. Hence, never queue them.
9151 ssh2_pkt_send_noqueue(ssh, pktout);
9155 * Handle the top-level SSH-2 protocol.
9157 static void ssh2_protocol_setup(Ssh ssh)
9162 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9164 for (i = 0; i < 256; i++)
9165 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9168 * Any message we actually understand, we set to NULL so that
9169 * the coroutines will get it.
9171 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
9172 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
9173 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
9174 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
9175 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
9176 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
9177 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
9178 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
9179 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
9180 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
9181 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
9182 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
9183 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
9184 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
9185 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9186 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
9187 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
9188 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
9189 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
9190 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
9191 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
9192 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
9193 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
9194 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
9195 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
9196 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
9197 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
9198 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
9199 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
9200 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
9201 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
9202 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
9203 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
9206 * These special message types we install handlers for.
9208 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9209 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9210 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9213 static void ssh2_timer(void *ctx, long now)
9217 if (ssh->state == SSH_STATE_CLOSED)
9220 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
9221 now - ssh->next_rekey >= 0) {
9222 do_ssh2_transport(ssh, "timeout", -1, NULL);
9226 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9227 struct Packet *pktin)
9229 unsigned char *in = (unsigned char *)vin;
9230 if (ssh->state == SSH_STATE_CLOSED)
9234 ssh->incoming_data_size += pktin->encrypted_len;
9235 if (!ssh->kex_in_progress &&
9236 ssh->max_data_size != 0 &&
9237 ssh->incoming_data_size > ssh->max_data_size)
9238 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9241 if (pktin && ssh->packet_dispatch[pktin->type]) {
9242 ssh->packet_dispatch[pktin->type](ssh, pktin);
9246 if (!ssh->protocol_initial_phase_done ||
9247 (pktin && pktin->type >= 20 && pktin->type < 50)) {
9248 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
9249 !ssh->protocol_initial_phase_done) {
9250 ssh->protocol_initial_phase_done = TRUE;
9252 * Allow authconn to initialise itself.
9254 do_ssh2_authconn(ssh, NULL, 0, NULL);
9257 do_ssh2_authconn(ssh, in, inlen, pktin);
9262 * Called to set up the connection.
9264 * Returns an error message, or NULL on success.
9266 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9268 char *host, int port, char **realhost, int nodelay,
9274 ssh = snew(struct ssh_tag);
9275 ssh->cfg = *cfg; /* STRUCTURE COPY */
9276 ssh->version = 0; /* when not ready yet */
9279 ssh->v1_cipher_ctx = NULL;
9280 ssh->crcda_ctx = NULL;
9281 ssh->cscipher = NULL;
9282 ssh->cs_cipher_ctx = NULL;
9283 ssh->sccipher = NULL;
9284 ssh->sc_cipher_ctx = NULL;
9286 ssh->cs_mac_ctx = NULL;
9288 ssh->sc_mac_ctx = NULL;
9290 ssh->cs_comp_ctx = NULL;
9292 ssh->sc_comp_ctx = NULL;
9294 ssh->kex_ctx = NULL;
9295 ssh->hostkey = NULL;
9297 ssh->close_expected = FALSE;
9298 ssh->clean_exit = FALSE;
9299 ssh->state = SSH_STATE_PREPACKET;
9300 ssh->size_needed = FALSE;
9301 ssh->eof_needed = FALSE;
9304 ssh->deferred_send_data = NULL;
9305 ssh->deferred_len = 0;
9306 ssh->deferred_size = 0;
9307 ssh->fallback_cmd = 0;
9308 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9309 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9310 ssh->x11disp = NULL;
9311 ssh->v1_compressing = FALSE;
9312 ssh->v2_outgoing_sequence = 0;
9313 ssh->ssh1_rdpkt_crstate = 0;
9314 ssh->ssh2_rdpkt_crstate = 0;
9315 ssh->do_ssh_init_crstate = 0;
9316 ssh->ssh_gotdata_crstate = 0;
9317 ssh->do_ssh1_connection_crstate = 0;
9318 ssh->do_ssh1_login_crstate = 0;
9319 ssh->do_ssh2_transport_crstate = 0;
9320 ssh->do_ssh2_authconn_crstate = 0;
9321 ssh->do_ssh_init_state = NULL;
9322 ssh->do_ssh1_login_state = NULL;
9323 ssh->do_ssh2_transport_state = NULL;
9324 ssh->do_ssh2_authconn_state = NULL;
9327 ssh->mainchan = NULL;
9328 ssh->throttled_all = 0;
9329 ssh->v1_stdout_throttling = 0;
9331 ssh->queuelen = ssh->queuesize = 0;
9332 ssh->queueing = FALSE;
9333 ssh->qhead = ssh->qtail = NULL;
9334 ssh->deferred_rekey_reason = NULL;
9335 bufchain_init(&ssh->queued_incoming_data);
9336 ssh->frozen = FALSE;
9338 *backend_handle = ssh;
9341 if (crypto_startup() == 0)
9342 return "Microsoft high encryption pack not installed!";
9345 ssh->frontend = frontend_handle;
9346 ssh->term_width = ssh->cfg.width;
9347 ssh->term_height = ssh->cfg.height;
9349 ssh->channels = NULL;
9350 ssh->rportfwds = NULL;
9351 ssh->portfwds = NULL;
9356 ssh->conn_throttle_count = 0;
9357 ssh->overall_bufsize = 0;
9358 ssh->fallback_cmd = 0;
9360 ssh->protocol = NULL;
9362 ssh->protocol_initial_phase_done = FALSE;
9366 ssh->incoming_data_size = ssh->outgoing_data_size =
9367 ssh->deferred_data_size = 0L;
9368 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
9369 ssh->kex_in_progress = FALSE;
9372 ssh->gsslibs = NULL;
9375 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9384 static void ssh_free(void *handle)
9386 Ssh ssh = (Ssh) handle;
9387 struct ssh_channel *c;
9388 struct ssh_rportfwd *pf;
9390 if (ssh->v1_cipher_ctx)
9391 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9392 if (ssh->cs_cipher_ctx)
9393 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9394 if (ssh->sc_cipher_ctx)
9395 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9396 if (ssh->cs_mac_ctx)
9397 ssh->csmac->free_context(ssh->cs_mac_ctx);
9398 if (ssh->sc_mac_ctx)
9399 ssh->scmac->free_context(ssh->sc_mac_ctx);
9400 if (ssh->cs_comp_ctx) {
9402 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9404 zlib_compress_cleanup(ssh->cs_comp_ctx);
9406 if (ssh->sc_comp_ctx) {
9408 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9410 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9413 dh_cleanup(ssh->kex_ctx);
9414 sfree(ssh->savedhost);
9416 while (ssh->queuelen-- > 0)
9417 ssh_free_packet(ssh->queue[ssh->queuelen]);
9420 while (ssh->qhead) {
9421 struct queued_handler *qh = ssh->qhead;
9422 ssh->qhead = qh->next;
9425 ssh->qhead = ssh->qtail = NULL;
9427 if (ssh->channels) {
9428 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9431 if (c->u.x11.s != NULL)
9432 x11_close(c->u.x11.s);
9435 case CHAN_SOCKDATA_DORMANT:
9436 if (c->u.pfd.s != NULL)
9437 pfd_close(c->u.pfd.s);
9442 freetree234(ssh->channels);
9443 ssh->channels = NULL;
9446 if (ssh->rportfwds) {
9447 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9449 freetree234(ssh->rportfwds);
9450 ssh->rportfwds = NULL;
9452 sfree(ssh->deferred_send_data);
9454 x11_free_display(ssh->x11disp);
9455 sfree(ssh->do_ssh_init_state);
9456 sfree(ssh->do_ssh1_login_state);
9457 sfree(ssh->do_ssh2_transport_state);
9458 sfree(ssh->do_ssh2_authconn_state);
9461 sfree(ssh->fullhostname);
9462 if (ssh->crcda_ctx) {
9463 crcda_free_context(ssh->crcda_ctx);
9464 ssh->crcda_ctx = NULL;
9467 ssh_do_close(ssh, TRUE);
9468 expire_timer_context(ssh);
9470 pinger_free(ssh->pinger);
9471 bufchain_clear(&ssh->queued_incoming_data);
9474 ssh_gss_cleanup(ssh->gsslibs);
9482 * Reconfigure the SSH backend.
9484 static void ssh_reconfig(void *handle, Config *cfg)
9486 Ssh ssh = (Ssh) handle;
9487 char *rekeying = NULL, rekey_mandatory = FALSE;
9488 unsigned long old_max_data_size;
9490 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
9492 ssh_setup_portfwd(ssh, cfg);
9494 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
9495 cfg->ssh_rekey_time != 0) {
9496 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
9497 long now = GETTICKCOUNT();
9499 if (new_next - now < 0) {
9500 rekeying = "timeout shortened";
9502 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9506 old_max_data_size = ssh->max_data_size;
9507 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
9508 if (old_max_data_size != ssh->max_data_size &&
9509 ssh->max_data_size != 0) {
9510 if (ssh->outgoing_data_size > ssh->max_data_size ||
9511 ssh->incoming_data_size > ssh->max_data_size)
9512 rekeying = "data limit lowered";
9515 if (ssh->cfg.compression != cfg->compression) {
9516 rekeying = "compression setting changed";
9517 rekey_mandatory = TRUE;
9520 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
9521 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
9522 sizeof(ssh->cfg.ssh_cipherlist))) {
9523 rekeying = "cipher settings changed";
9524 rekey_mandatory = TRUE;
9527 ssh->cfg = *cfg; /* STRUCTURE COPY */
9530 if (!ssh->kex_in_progress) {
9531 do_ssh2_transport(ssh, rekeying, -1, NULL);
9532 } else if (rekey_mandatory) {
9533 ssh->deferred_rekey_reason = rekeying;
9539 * Called to send data down the SSH connection.
9541 static int ssh_send(void *handle, char *buf, int len)
9543 Ssh ssh = (Ssh) handle;
9545 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
9548 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
9550 return ssh_sendbuffer(ssh);
9554 * Called to query the current amount of buffered stdin data.
9556 static int ssh_sendbuffer(void *handle)
9558 Ssh ssh = (Ssh) handle;
9561 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
9565 * If the SSH socket itself has backed up, add the total backup
9566 * size on that to any individual buffer on the stdin channel.
9569 if (ssh->throttled_all)
9570 override_value = ssh->overall_bufsize;
9572 if (ssh->version == 1) {
9573 return override_value;
9574 } else if (ssh->version == 2) {
9575 if (!ssh->mainchan || ssh->mainchan->closes > 0)
9576 return override_value;
9578 return (override_value +
9579 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
9586 * Called to set the size of the window from SSH's POV.
9588 static void ssh_size(void *handle, int width, int height)
9590 Ssh ssh = (Ssh) handle;
9591 struct Packet *pktout;
9593 ssh->term_width = width;
9594 ssh->term_height = height;
9596 switch (ssh->state) {
9597 case SSH_STATE_BEFORE_SIZE:
9598 case SSH_STATE_PREPACKET:
9599 case SSH_STATE_CLOSED:
9600 break; /* do nothing */
9601 case SSH_STATE_INTERMED:
9602 ssh->size_needed = TRUE; /* buffer for later */
9604 case SSH_STATE_SESSION:
9605 if (!ssh->cfg.nopty) {
9606 if (ssh->version == 1) {
9607 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
9608 PKT_INT, ssh->term_height,
9609 PKT_INT, ssh->term_width,
9610 PKT_INT, 0, PKT_INT, 0, PKT_END);
9611 } else if (ssh->mainchan) {
9612 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9613 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9614 ssh2_pkt_addstring(pktout, "window-change");
9615 ssh2_pkt_addbool(pktout, 0);
9616 ssh2_pkt_adduint32(pktout, ssh->term_width);
9617 ssh2_pkt_adduint32(pktout, ssh->term_height);
9618 ssh2_pkt_adduint32(pktout, 0);
9619 ssh2_pkt_adduint32(pktout, 0);
9620 ssh2_pkt_send(ssh, pktout);
9628 * Return a list of the special codes that make sense in this
9631 static const struct telnet_special *ssh_get_specials(void *handle)
9633 static const struct telnet_special ssh1_ignore_special[] = {
9634 {"IGNORE message", TS_NOP}
9636 static const struct telnet_special ssh2_ignore_special[] = {
9637 {"IGNORE message", TS_NOP},
9639 static const struct telnet_special ssh2_rekey_special[] = {
9640 {"Repeat key exchange", TS_REKEY},
9642 static const struct telnet_special ssh2_session_specials[] = {
9645 /* These are the signal names defined by RFC 4254.
9646 * They include all the ISO C signals, but are a subset of the POSIX
9647 * required signals. */
9648 {"SIGINT (Interrupt)", TS_SIGINT},
9649 {"SIGTERM (Terminate)", TS_SIGTERM},
9650 {"SIGKILL (Kill)", TS_SIGKILL},
9651 {"SIGQUIT (Quit)", TS_SIGQUIT},
9652 {"SIGHUP (Hangup)", TS_SIGHUP},
9653 {"More signals", TS_SUBMENU},
9654 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
9655 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
9656 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
9657 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
9660 static const struct telnet_special specials_end[] = {
9663 /* XXX review this length for any changes: */
9664 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
9665 lenof(ssh2_rekey_special) +
9666 lenof(ssh2_session_specials) +
9667 lenof(specials_end)];
9668 Ssh ssh = (Ssh) handle;
9670 #define ADD_SPECIALS(name) \
9672 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9673 memcpy(&ssh_specials[i], name, sizeof name); \
9677 if (ssh->version == 1) {
9678 /* Don't bother offering IGNORE if we've decided the remote
9679 * won't cope with it, since we wouldn't bother sending it if
9681 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9682 ADD_SPECIALS(ssh1_ignore_special);
9683 } else if (ssh->version == 2) {
9684 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
9685 ADD_SPECIALS(ssh2_ignore_special);
9686 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
9687 ADD_SPECIALS(ssh2_rekey_special);
9689 ADD_SPECIALS(ssh2_session_specials);
9690 } /* else we're not ready yet */
9693 ADD_SPECIALS(specials_end);
9694 return ssh_specials;
9702 * Send special codes. TS_EOF is useful for `plink', so you
9703 * can send an EOF and collect resulting output (e.g. `plink
9706 static void ssh_special(void *handle, Telnet_Special code)
9708 Ssh ssh = (Ssh) handle;
9709 struct Packet *pktout;
9711 if (code == TS_EOF) {
9712 if (ssh->state != SSH_STATE_SESSION) {
9714 * Buffer the EOF in case we are pre-SESSION, so we can
9715 * send it as soon as we reach SESSION.
9718 ssh->eof_needed = TRUE;
9721 if (ssh->version == 1) {
9722 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
9723 } else if (ssh->mainchan) {
9724 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
9725 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9726 ssh2_pkt_send(ssh, pktout);
9727 ssh->send_ok = 0; /* now stop trying to read from stdin */
9729 logevent("Sent EOF message");
9730 } else if (code == TS_PING || code == TS_NOP) {
9731 if (ssh->state == SSH_STATE_CLOSED
9732 || ssh->state == SSH_STATE_PREPACKET) return;
9733 if (ssh->version == 1) {
9734 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
9735 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
9737 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
9738 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
9739 ssh2_pkt_addstring_start(pktout);
9740 ssh2_pkt_send_noqueue(ssh, pktout);
9743 } else if (code == TS_REKEY) {
9744 if (!ssh->kex_in_progress && ssh->version == 2) {
9745 do_ssh2_transport(ssh, "at user request", -1, NULL);
9747 } else if (code == TS_BRK) {
9748 if (ssh->state == SSH_STATE_CLOSED
9749 || ssh->state == SSH_STATE_PREPACKET) return;
9750 if (ssh->version == 1) {
9751 logevent("Unable to send BREAK signal in SSH-1");
9752 } else if (ssh->mainchan) {
9753 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9754 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9755 ssh2_pkt_addstring(pktout, "break");
9756 ssh2_pkt_addbool(pktout, 0);
9757 ssh2_pkt_adduint32(pktout, 0); /* default break length */
9758 ssh2_pkt_send(ssh, pktout);
9761 /* Is is a POSIX signal? */
9762 char *signame = NULL;
9763 if (code == TS_SIGABRT) signame = "ABRT";
9764 if (code == TS_SIGALRM) signame = "ALRM";
9765 if (code == TS_SIGFPE) signame = "FPE";
9766 if (code == TS_SIGHUP) signame = "HUP";
9767 if (code == TS_SIGILL) signame = "ILL";
9768 if (code == TS_SIGINT) signame = "INT";
9769 if (code == TS_SIGKILL) signame = "KILL";
9770 if (code == TS_SIGPIPE) signame = "PIPE";
9771 if (code == TS_SIGQUIT) signame = "QUIT";
9772 if (code == TS_SIGSEGV) signame = "SEGV";
9773 if (code == TS_SIGTERM) signame = "TERM";
9774 if (code == TS_SIGUSR1) signame = "USR1";
9775 if (code == TS_SIGUSR2) signame = "USR2";
9776 /* The SSH-2 protocol does in principle support arbitrary named
9777 * signals, including signame@domain, but we don't support those. */
9779 /* It's a signal. */
9780 if (ssh->version == 2 && ssh->mainchan) {
9781 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9782 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9783 ssh2_pkt_addstring(pktout, "signal");
9784 ssh2_pkt_addbool(pktout, 0);
9785 ssh2_pkt_addstring(pktout, signame);
9786 ssh2_pkt_send(ssh, pktout);
9787 logeventf(ssh, "Sent signal SIG%s", signame);
9790 /* Never heard of it. Do nothing */
9795 void *new_sock_channel(void *handle, Socket s)
9797 Ssh ssh = (Ssh) handle;
9798 struct ssh_channel *c;
9799 c = snew(struct ssh_channel);
9802 ssh2_channel_init(c);
9804 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
9806 add234(ssh->channels, c);
9811 * This is called when stdout/stderr (the entity to which
9812 * from_backend sends data) manages to clear some backlog.
9814 static void ssh_unthrottle(void *handle, int bufsize)
9816 Ssh ssh = (Ssh) handle;
9819 if (ssh->version == 1) {
9820 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
9821 ssh->v1_stdout_throttling = 0;
9822 ssh_throttle_conn(ssh, -1);
9825 if (ssh->mainchan) {
9826 ssh2_set_window(ssh->mainchan,
9827 bufsize < ssh->mainchan->v.v2.locmaxwin ?
9828 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
9829 if (ssh->cfg.ssh_simple)
9832 buflimit = ssh->mainchan->v.v2.locmaxwin;
9833 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
9834 ssh->mainchan->throttling_conn = 0;
9835 ssh_throttle_conn(ssh, -1);
9841 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
9843 struct ssh_channel *c = (struct ssh_channel *)channel;
9845 struct Packet *pktout;
9847 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
9849 if (ssh->version == 1) {
9850 send_packet(ssh, SSH1_MSG_PORT_OPEN,
9851 PKT_INT, c->localid,
9854 /* PKT_STR, <org:orgport>, */
9857 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9858 ssh2_pkt_addstring(pktout, "direct-tcpip");
9859 ssh2_pkt_adduint32(pktout, c->localid);
9860 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
9861 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
9862 ssh2_pkt_addstring(pktout, hostname);
9863 ssh2_pkt_adduint32(pktout, port);
9865 * We make up values for the originator data; partly it's
9866 * too much hassle to keep track, and partly I'm not
9867 * convinced the server should be told details like that
9868 * about my local network configuration.
9869 * The "originator IP address" is syntactically a numeric
9870 * IP address, and some servers (e.g., Tectia) get upset
9871 * if it doesn't match this syntax.
9873 ssh2_pkt_addstring(pktout, "0.0.0.0");
9874 ssh2_pkt_adduint32(pktout, 0);
9875 ssh2_pkt_send(ssh, pktout);
9879 static int ssh_connected(void *handle)
9881 Ssh ssh = (Ssh) handle;
9882 return ssh->s != NULL;
9885 static int ssh_sendok(void *handle)
9887 Ssh ssh = (Ssh) handle;
9888 return ssh->send_ok;
9891 static int ssh_ldisc(void *handle, int option)
9893 Ssh ssh = (Ssh) handle;
9894 if (option == LD_ECHO)
9895 return ssh->echoing;
9896 if (option == LD_EDIT)
9897 return ssh->editing;
9901 static void ssh_provide_ldisc(void *handle, void *ldisc)
9903 Ssh ssh = (Ssh) handle;
9907 static void ssh_provide_logctx(void *handle, void *logctx)
9909 Ssh ssh = (Ssh) handle;
9910 ssh->logctx = logctx;
9913 static int ssh_return_exitcode(void *handle)
9915 Ssh ssh = (Ssh) handle;
9919 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
9923 * cfg_info for SSH is the currently running version of the
9924 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
9926 static int ssh_cfg_info(void *handle)
9928 Ssh ssh = (Ssh) handle;
9929 return ssh->version;
9933 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
9934 * that fails. This variable is the means by which scp.c can reach
9935 * into the SSH code and find out which one it got.
9937 extern int ssh_fallback_cmd(void *handle)
9939 Ssh ssh = (Ssh) handle;
9940 return ssh->fallback_cmd;
9943 Backend ssh_backend = {
9953 ssh_return_exitcode,