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
199 #define BUG_CHOKES_ON_WINADJ 1024
202 * Codes for terminal modes.
203 * Most of these are the same in SSH-1 and SSH-2.
204 * This list is derived from RFC 4254 and
207 static const struct {
208 const char* const mode;
210 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
212 /* "V" prefix discarded for special characters relative to SSH specs */
213 { "INTR", 1, TTY_OP_CHAR },
214 { "QUIT", 2, TTY_OP_CHAR },
215 { "ERASE", 3, TTY_OP_CHAR },
216 { "KILL", 4, TTY_OP_CHAR },
217 { "EOF", 5, TTY_OP_CHAR },
218 { "EOL", 6, TTY_OP_CHAR },
219 { "EOL2", 7, TTY_OP_CHAR },
220 { "START", 8, TTY_OP_CHAR },
221 { "STOP", 9, TTY_OP_CHAR },
222 { "SUSP", 10, TTY_OP_CHAR },
223 { "DSUSP", 11, TTY_OP_CHAR },
224 { "REPRINT", 12, TTY_OP_CHAR },
225 { "WERASE", 13, TTY_OP_CHAR },
226 { "LNEXT", 14, TTY_OP_CHAR },
227 { "FLUSH", 15, TTY_OP_CHAR },
228 { "SWTCH", 16, TTY_OP_CHAR },
229 { "STATUS", 17, TTY_OP_CHAR },
230 { "DISCARD", 18, TTY_OP_CHAR },
231 { "IGNPAR", 30, TTY_OP_BOOL },
232 { "PARMRK", 31, TTY_OP_BOOL },
233 { "INPCK", 32, TTY_OP_BOOL },
234 { "ISTRIP", 33, TTY_OP_BOOL },
235 { "INLCR", 34, TTY_OP_BOOL },
236 { "IGNCR", 35, TTY_OP_BOOL },
237 { "ICRNL", 36, TTY_OP_BOOL },
238 { "IUCLC", 37, TTY_OP_BOOL },
239 { "IXON", 38, TTY_OP_BOOL },
240 { "IXANY", 39, TTY_OP_BOOL },
241 { "IXOFF", 40, TTY_OP_BOOL },
242 { "IMAXBEL", 41, TTY_OP_BOOL },
243 { "ISIG", 50, TTY_OP_BOOL },
244 { "ICANON", 51, TTY_OP_BOOL },
245 { "XCASE", 52, TTY_OP_BOOL },
246 { "ECHO", 53, TTY_OP_BOOL },
247 { "ECHOE", 54, TTY_OP_BOOL },
248 { "ECHOK", 55, TTY_OP_BOOL },
249 { "ECHONL", 56, TTY_OP_BOOL },
250 { "NOFLSH", 57, TTY_OP_BOOL },
251 { "TOSTOP", 58, TTY_OP_BOOL },
252 { "IEXTEN", 59, TTY_OP_BOOL },
253 { "ECHOCTL", 60, TTY_OP_BOOL },
254 { "ECHOKE", 61, TTY_OP_BOOL },
255 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
256 { "OPOST", 70, TTY_OP_BOOL },
257 { "OLCUC", 71, TTY_OP_BOOL },
258 { "ONLCR", 72, TTY_OP_BOOL },
259 { "OCRNL", 73, TTY_OP_BOOL },
260 { "ONOCR", 74, TTY_OP_BOOL },
261 { "ONLRET", 75, TTY_OP_BOOL },
262 { "CS7", 90, TTY_OP_BOOL },
263 { "CS8", 91, TTY_OP_BOOL },
264 { "PARENB", 92, TTY_OP_BOOL },
265 { "PARODD", 93, TTY_OP_BOOL }
268 /* Miscellaneous other tty-related constants. */
269 #define SSH_TTY_OP_END 0
270 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
271 #define SSH1_TTY_OP_ISPEED 192
272 #define SSH1_TTY_OP_OSPEED 193
273 #define SSH2_TTY_OP_ISPEED 128
274 #define SSH2_TTY_OP_OSPEED 129
276 /* Helper functions for parsing tty-related config. */
277 static unsigned int ssh_tty_parse_specchar(char *s)
282 ret = ctrlparse(s, &next);
283 if (!next) ret = s[0];
285 ret = 255; /* special value meaning "don't set" */
289 static unsigned int ssh_tty_parse_boolean(char *s)
291 if (stricmp(s, "yes") == 0 ||
292 stricmp(s, "on") == 0 ||
293 stricmp(s, "true") == 0 ||
294 stricmp(s, "+") == 0)
296 else if (stricmp(s, "no") == 0 ||
297 stricmp(s, "off") == 0 ||
298 stricmp(s, "false") == 0 ||
299 stricmp(s, "-") == 0)
300 return 0; /* false */
302 return (atoi(s) != 0);
305 #define translate(x) if (type == x) return #x
306 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
307 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
308 static char *ssh1_pkt_type(int type)
310 translate(SSH1_MSG_DISCONNECT);
311 translate(SSH1_SMSG_PUBLIC_KEY);
312 translate(SSH1_CMSG_SESSION_KEY);
313 translate(SSH1_CMSG_USER);
314 translate(SSH1_CMSG_AUTH_RSA);
315 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
316 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
317 translate(SSH1_CMSG_AUTH_PASSWORD);
318 translate(SSH1_CMSG_REQUEST_PTY);
319 translate(SSH1_CMSG_WINDOW_SIZE);
320 translate(SSH1_CMSG_EXEC_SHELL);
321 translate(SSH1_CMSG_EXEC_CMD);
322 translate(SSH1_SMSG_SUCCESS);
323 translate(SSH1_SMSG_FAILURE);
324 translate(SSH1_CMSG_STDIN_DATA);
325 translate(SSH1_SMSG_STDOUT_DATA);
326 translate(SSH1_SMSG_STDERR_DATA);
327 translate(SSH1_CMSG_EOF);
328 translate(SSH1_SMSG_EXIT_STATUS);
329 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
330 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
331 translate(SSH1_MSG_CHANNEL_DATA);
332 translate(SSH1_MSG_CHANNEL_CLOSE);
333 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
334 translate(SSH1_SMSG_X11_OPEN);
335 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
336 translate(SSH1_MSG_PORT_OPEN);
337 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
338 translate(SSH1_SMSG_AGENT_OPEN);
339 translate(SSH1_MSG_IGNORE);
340 translate(SSH1_CMSG_EXIT_CONFIRMATION);
341 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
342 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
343 translate(SSH1_MSG_DEBUG);
344 translate(SSH1_CMSG_REQUEST_COMPRESSION);
345 translate(SSH1_CMSG_AUTH_TIS);
346 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
347 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
348 translate(SSH1_CMSG_AUTH_CCARD);
349 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
350 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
353 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
355 translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI);
356 translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI);
357 translatea(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,SSH2_PKTCTX_GSSAPI);
358 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERROR,SSH2_PKTCTX_GSSAPI);
359 translatea(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK,SSH2_PKTCTX_GSSAPI);
360 translatea(SSH2_MSG_USERAUTH_GSSAPI_MIC, SSH2_PKTCTX_GSSAPI);
361 translate(SSH2_MSG_DISCONNECT);
362 translate(SSH2_MSG_IGNORE);
363 translate(SSH2_MSG_UNIMPLEMENTED);
364 translate(SSH2_MSG_DEBUG);
365 translate(SSH2_MSG_SERVICE_REQUEST);
366 translate(SSH2_MSG_SERVICE_ACCEPT);
367 translate(SSH2_MSG_KEXINIT);
368 translate(SSH2_MSG_NEWKEYS);
369 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
370 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
371 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
372 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
373 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
374 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
375 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
376 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
377 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
378 translate(SSH2_MSG_USERAUTH_REQUEST);
379 translate(SSH2_MSG_USERAUTH_FAILURE);
380 translate(SSH2_MSG_USERAUTH_SUCCESS);
381 translate(SSH2_MSG_USERAUTH_BANNER);
382 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
383 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
384 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
385 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
386 translate(SSH2_MSG_GLOBAL_REQUEST);
387 translate(SSH2_MSG_REQUEST_SUCCESS);
388 translate(SSH2_MSG_REQUEST_FAILURE);
389 translate(SSH2_MSG_CHANNEL_OPEN);
390 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
391 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
392 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
393 translate(SSH2_MSG_CHANNEL_DATA);
394 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
395 translate(SSH2_MSG_CHANNEL_EOF);
396 translate(SSH2_MSG_CHANNEL_CLOSE);
397 translate(SSH2_MSG_CHANNEL_REQUEST);
398 translate(SSH2_MSG_CHANNEL_SUCCESS);
399 translate(SSH2_MSG_CHANNEL_FAILURE);
405 /* Enumeration values for fields in SSH-1 packets */
407 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
408 /* These values are for communicating relevant semantics of
409 * fields to the packet logging code. */
410 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
414 * Coroutine mechanics for the sillier bits of the code. If these
415 * macros look impenetrable to you, you might find it helpful to
418 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
420 * which explains the theory behind these macros.
422 * In particular, if you are getting `case expression not constant'
423 * errors when building with MS Visual Studio, this is because MS's
424 * Edit and Continue debugging feature causes their compiler to
425 * violate ANSI C. To disable Edit and Continue debugging:
427 * - right-click ssh.c in the FileView
429 * - select the C/C++ tab and the General category
430 * - under `Debug info:', select anything _other_ than `Program
431 * Database for Edit and Continue'.
433 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
434 #define crBeginState crBegin(s->crLine)
435 #define crStateP(t, v) \
437 if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
439 #define crState(t) crStateP(t, ssh->t)
440 #define crFinish(z) } *crLine = 0; return (z); }
441 #define crFinishV } *crLine = 0; return; }
442 #define crFinishFree(z) } sfree(s); return (z); }
443 #define crFinishFreeV } sfree(s); return; }
444 #define crReturn(z) \
446 *crLine =__LINE__; return (z); case __LINE__:;\
450 *crLine=__LINE__; return; case __LINE__:;\
452 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
453 #define crStopV do{ *crLine = 0; return; }while(0)
454 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
455 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
457 typedef struct ssh_tag *Ssh;
460 static struct Packet *ssh1_pkt_init(int pkt_type);
461 static struct Packet *ssh2_pkt_init(int pkt_type);
462 static void ssh_pkt_ensure(struct Packet *, int length);
463 static void ssh_pkt_adddata(struct Packet *, const void *data, int len);
464 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
465 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
466 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
467 static void ssh_pkt_addstring_start(struct Packet *);
468 static void ssh_pkt_addstring_str(struct Packet *, const char *data);
469 static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len);
470 static void ssh_pkt_addstring(struct Packet *, const char *data);
471 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
472 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
473 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
474 static int ssh2_pkt_construct(Ssh, struct Packet *);
475 static void ssh2_pkt_send(Ssh, struct Packet *);
476 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
477 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
478 struct Packet *pktin);
479 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
480 struct Packet *pktin);
481 static void ssh2_channel_check_close(struct ssh_channel *c);
482 static void ssh_channel_destroy(struct ssh_channel *c);
485 * Buffer management constants. There are several of these for
486 * various different purposes:
488 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
489 * on a local data stream before we throttle the whole SSH
490 * connection (in SSH-1 only). Throttling the whole connection is
491 * pretty drastic so we set this high in the hope it won't
494 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
495 * on the SSH connection itself before we defensively throttle
496 * _all_ local data streams. This is pretty drastic too (though
497 * thankfully unlikely in SSH-2 since the window mechanism should
498 * ensure that the server never has any need to throttle its end
499 * of the connection), so we set this high as well.
501 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
504 * - OUR_V2_BIGWIN is the window size we advertise for the only
505 * channel in a simple connection. It must be <= INT_MAX.
507 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
508 * to the remote side. This actually has nothing to do with the
509 * size of the _packet_, but is instead a limit on the amount
510 * of data we're willing to receive in a single SSH2 channel
513 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
514 * _packet_ we're prepared to cope with. It must be a multiple
515 * of the cipher block size, and must be at least 35000.
518 #define SSH1_BUFFER_LIMIT 32768
519 #define SSH_MAX_BACKLOG 32768
520 #define OUR_V2_WINSIZE 16384
521 #define OUR_V2_BIGWIN 0x7fffffff
522 #define OUR_V2_MAXPKT 0x4000UL
523 #define OUR_V2_PACKETLIMIT 0x9000UL
525 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
527 const static struct ssh_mac *macs[] = {
528 &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
530 const static struct ssh_mac *buggymacs[] = {
531 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
534 static void *ssh_comp_none_init(void)
538 static void ssh_comp_none_cleanup(void *handle)
541 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
542 unsigned char **outblock, int *outlen)
546 static int ssh_comp_none_disable(void *handle)
550 const static struct ssh_compress ssh_comp_none = {
552 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
553 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
554 ssh_comp_none_disable, NULL
556 extern const struct ssh_compress ssh_zlib;
557 const static struct ssh_compress *compressions[] = {
558 &ssh_zlib, &ssh_comp_none
561 enum { /* channel types */
566 CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */
568 * CHAN_ZOMBIE is used to indicate a channel for which we've
569 * already destroyed the local data source: for instance, if a
570 * forwarded port experiences a socket error on the local side, we
571 * immediately destroy its local socket and turn the SSH channel
577 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
578 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
579 typedef void (*cchandler_fn_t)(struct ssh_channel *, struct Packet *, void *);
582 * Each channel has a queue of outstanding CHANNEL_REQUESTS and their
585 struct outstanding_channel_request {
586 cchandler_fn_t handler;
588 struct outstanding_channel_request *next;
592 * 2-3-4 tree storing channels.
595 Ssh ssh; /* pointer back to main context */
596 unsigned remoteid, localid;
598 /* True if we opened this channel but server hasn't confirmed. */
601 * In SSH-1, this value contains four bits:
603 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
604 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
605 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
606 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
608 * A channel is completely finished with when all four bits are set.
610 * In SSH-2, the four bits mean:
612 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
613 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
614 * 4 We have received SSH2_MSG_CHANNEL_EOF.
615 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
617 * A channel is completely finished with when we have both sent
618 * and received CLOSE.
620 * The symbolic constants below use the SSH-2 terminology, which
621 * is a bit confusing in SSH-1, but we have to use _something_.
623 #define CLOSES_SENT_EOF 1
624 #define CLOSES_SENT_CLOSE 2
625 #define CLOSES_RCVD_EOF 4
626 #define CLOSES_RCVD_CLOSE 8
630 * This flag indicates that an EOF is pending on the outgoing side
631 * of the channel: that is, wherever we're getting the data for
632 * this channel has sent us some data followed by EOF. We can't
633 * actually send the EOF until we've finished sending the data, so
634 * we set this flag instead to remind us to do so once our buffer
640 * True if this channel is causing the underlying connection to be
645 struct ssh2_data_channel {
647 unsigned remwindow, remmaxpkt;
648 /* locwindow is signed so we can cope with excess data. */
649 int locwindow, locmaxwin;
651 * remlocwin is the amount of local window that we think
652 * the remote end had available to it after it sent the
653 * last data packet or window adjust ack.
657 * These store the list of channel requests that haven't
660 struct outstanding_channel_request *chanreq_head, *chanreq_tail;
661 enum { THROTTLED, UNTHROTTLING, UNTHROTTLED } throttle_state;
665 struct ssh_agent_channel {
666 unsigned char *message;
667 unsigned char msglen[4];
668 unsigned lensofar, totallen;
669 int outstanding_requests;
671 struct ssh_x11_channel {
674 struct ssh_pfd_channel {
681 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
682 * use this structure in different ways, reflecting SSH-2's
683 * altogether saner approach to port forwarding.
685 * In SSH-1, you arrange a remote forwarding by sending the server
686 * the remote port number, and the local destination host:port.
687 * When a connection comes in, the server sends you back that
688 * host:port pair, and you connect to it. This is a ready-made
689 * security hole if you're not on the ball: a malicious server
690 * could send you back _any_ host:port pair, so if you trustingly
691 * connect to the address it gives you then you've just opened the
692 * entire inside of your corporate network just by connecting
693 * through it to a dodgy SSH server. Hence, we must store a list of
694 * host:port pairs we _are_ trying to forward to, and reject a
695 * connection request from the server if it's not in the list.
697 * In SSH-2, each side of the connection minds its own business and
698 * doesn't send unnecessary information to the other. You arrange a
699 * remote forwarding by sending the server just the remote port
700 * number. When a connection comes in, the server tells you which
701 * of its ports was connected to; and _you_ have to remember what
702 * local host:port pair went with that port number.
704 * Hence, in SSH-1 this structure is indexed by destination
705 * host:port pair, whereas in SSH-2 it is indexed by source port.
707 struct ssh_portfwd; /* forward declaration */
709 struct ssh_rportfwd {
710 unsigned sport, dport;
713 struct ssh_portfwd *pfrec;
716 static void free_rportfwd(struct ssh_rportfwd *pf)
719 sfree(pf->sportdesc);
727 * Separately to the rportfwd tree (which is for looking up port
728 * open requests from the server), a tree of _these_ structures is
729 * used to keep track of all the currently open port forwardings,
730 * so that we can reconfigure in mid-session if the user requests
734 enum { DESTROY, KEEP, CREATE } status;
736 unsigned sport, dport;
739 struct ssh_rportfwd *remote;
743 #define free_portfwd(pf) ( \
744 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
745 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
748 long length; /* length of `data' actually used */
749 long forcepad; /* SSH-2: force padding to at least this length */
750 int type; /* only used for incoming packets */
751 unsigned long sequence; /* SSH-2 incoming sequence number */
752 unsigned char *data; /* allocated storage */
753 unsigned char *body; /* offset of payload within `data' */
754 long savedpos; /* temporary index into `data' (for strings) */
755 long maxlen; /* amount of storage allocated for `data' */
756 long encrypted_len; /* for SSH-2 total-size counting */
759 * State associated with packet logging
763 struct logblank_t *blanks;
766 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
767 struct Packet *pktin);
768 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
769 struct Packet *pktin);
770 static void ssh1_protocol_setup(Ssh ssh);
771 static void ssh2_protocol_setup(Ssh ssh);
772 static void ssh_size(void *handle, int width, int height);
773 static void ssh_special(void *handle, Telnet_Special);
774 static int ssh2_try_send(struct ssh_channel *c);
775 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
776 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
777 static void ssh2_set_window(struct ssh_channel *c, int newwin);
778 static int ssh_sendbuffer(void *handle);
779 static int ssh_do_close(Ssh ssh, int notify_exit);
780 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
781 static int ssh2_pkt_getbool(struct Packet *pkt);
782 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
783 static void ssh2_timer(void *ctx, unsigned long now);
784 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
785 struct Packet *pktin);
786 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
788 struct rdpkt1_state_tag {
789 long len, pad, biglen, to_read;
790 unsigned long realcrc, gotcrc;
794 struct Packet *pktin;
797 struct rdpkt2_state_tag {
798 long len, pad, payload, packetlen, maclen;
801 unsigned long incoming_sequence;
802 struct Packet *pktin;
805 struct queued_handler;
806 struct queued_handler {
808 chandler_fn_t handler;
810 struct queued_handler *next;
814 const struct plug_function_table *fn;
815 /* the above field _must_ be first in the structure */
825 unsigned char session_key[32];
827 int v1_remote_protoflags;
828 int v1_local_protoflags;
829 int agentfwd_enabled;
832 const struct ssh_cipher *cipher;
835 const struct ssh2_cipher *cscipher, *sccipher;
836 void *cs_cipher_ctx, *sc_cipher_ctx;
837 const struct ssh_mac *csmac, *scmac;
838 void *cs_mac_ctx, *sc_mac_ctx;
839 const struct ssh_compress *cscomp, *sccomp;
840 void *cs_comp_ctx, *sc_comp_ctx;
841 const struct ssh_kex *kex;
842 const struct ssh_signkey *hostkey;
843 char *hostkey_str; /* string representation, for easy checking in rekeys */
844 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
845 int v2_session_id_len;
851 int echoing, editing;
855 int ospeed, ispeed; /* temporaries */
856 int term_width, term_height;
858 tree234 *channels; /* indexed by local id */
859 struct ssh_channel *mainchan; /* primary session channel */
860 int ncmode; /* is primary channel direct-tcpip? */
865 tree234 *rportfwds, *portfwds;
869 SSH_STATE_BEFORE_SIZE,
875 int size_needed, eof_needed;
876 int sent_console_eof;
877 int got_pty; /* affects EOF behaviour on main channel */
879 struct Packet **queue;
880 int queuelen, queuesize;
882 unsigned char *deferred_send_data;
883 int deferred_len, deferred_size;
886 * Gross hack: pscp will try to start SFTP but fall back to
887 * scp1 if that fails. This variable is the means by which
888 * scp.c can reach into the SSH code and find out which one it
893 bufchain banner; /* accumulates banners during do_ssh2_authconn */
898 struct X11Display *x11disp;
901 int conn_throttle_count;
904 int v1_stdout_throttling;
905 unsigned long v2_outgoing_sequence;
907 int ssh1_rdpkt_crstate;
908 int ssh2_rdpkt_crstate;
909 int ssh_gotdata_crstate;
910 int do_ssh1_connection_crstate;
912 void *do_ssh_init_state;
913 void *do_ssh1_login_state;
914 void *do_ssh2_transport_state;
915 void *do_ssh2_authconn_state;
917 struct rdpkt1_state_tag rdpkt1_state;
918 struct rdpkt2_state_tag rdpkt2_state;
920 /* SSH-1 and SSH-2 use this for different things, but both use it */
921 int protocol_initial_phase_done;
923 void (*protocol) (Ssh ssh, void *vin, int inlen,
925 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
928 * We maintain our own copy of a Conf structure here. That way,
929 * when we're passed a new one for reconfiguration, we can check
930 * the differences and potentially reconfigure port forwardings
931 * etc in mid-session.
936 * Values cached out of conf so as to avoid the tree234 lookup
937 * cost every time they're used.
942 * Dynamically allocated username string created during SSH
943 * login. Stored in here rather than in the coroutine state so
944 * that it'll be reliably freed if we shut down the SSH session
945 * at some unexpected moment.
950 * Used to transfer data back from async callbacks.
952 void *agent_response;
953 int agent_response_len;
957 * The SSH connection can be set as `frozen', meaning we are
958 * not currently accepting incoming data from the network. This
959 * is slightly more serious than setting the _socket_ as
960 * frozen, because we may already have had data passed to us
961 * from the network which we need to delay processing until
962 * after the freeze is lifted, so we also need a bufchain to
966 bufchain queued_incoming_data;
969 * Dispatch table for packet types that we may have to deal
972 handler_fn_t packet_dispatch[256];
975 * Queues of one-off handler functions for success/failure
976 * indications from a request.
978 struct queued_handler *qhead, *qtail;
979 handler_fn_t q_saved_handler1, q_saved_handler2;
982 * This module deals with sending keepalives.
987 * Track incoming and outgoing data sizes and time, for
990 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
991 unsigned long max_data_size;
993 unsigned long next_rekey, last_rekey;
994 char *deferred_rekey_reason; /* points to STATIC string; don't free */
997 * Fully qualified host name, which we need if doing GSSAPI.
1003 * GSSAPI libraries for this session.
1005 struct ssh_gss_liblist *gsslibs;
1009 #define logevent(s) logevent(ssh->frontend, s)
1011 /* logevent, only printf-formatted. */
1012 static void logeventf(Ssh ssh, const char *fmt, ...)
1018 buf = dupvprintf(fmt, ap);
1024 static void bomb_out(Ssh ssh, char *text)
1026 ssh_do_close(ssh, FALSE);
1028 connection_fatal(ssh->frontend, "%s", text);
1032 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1034 /* Functions to leave bits out of the SSH packet log file. */
1036 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
1038 if (conf_get_int(ssh->conf, CONF_logomitpass))
1039 pkt->logmode = blanktype;
1042 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
1044 if (ssh->logomitdata)
1045 pkt->logmode = blanktype;
1048 static void end_log_omission(Ssh ssh, struct Packet *pkt)
1050 pkt->logmode = PKTLOG_EMIT;
1053 /* Helper function for common bits of parsing ttymodes. */
1054 static void parse_ttymodes(Ssh ssh,
1055 void (*do_mode)(void *data, char *mode, char *val),
1060 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1062 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1064 * val[0] is either 'V', indicating that an explicit value
1065 * follows it, or 'A' indicating that we should pass the
1066 * value through from the local environment via get_ttymode.
1068 if (val[0] == 'A') {
1069 val = get_ttymode(ssh->frontend, key);
1071 do_mode(data, key, val);
1075 do_mode(data, key, val + 1); /* skip the 'V' */
1079 static int ssh_channelcmp(void *av, void *bv)
1081 struct ssh_channel *a = (struct ssh_channel *) av;
1082 struct ssh_channel *b = (struct ssh_channel *) bv;
1083 if (a->localid < b->localid)
1085 if (a->localid > b->localid)
1089 static int ssh_channelfind(void *av, void *bv)
1091 unsigned *a = (unsigned *) av;
1092 struct ssh_channel *b = (struct ssh_channel *) bv;
1093 if (*a < b->localid)
1095 if (*a > b->localid)
1100 static int ssh_rportcmp_ssh1(void *av, void *bv)
1102 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1103 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1105 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1106 return i < 0 ? -1 : +1;
1107 if (a->dport > b->dport)
1109 if (a->dport < b->dport)
1114 static int ssh_rportcmp_ssh2(void *av, void *bv)
1116 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1117 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1119 if ( (i = strcmp(a->shost, b->shost)) != 0)
1120 return i < 0 ? -1 : +1;
1121 if (a->sport > b->sport)
1123 if (a->sport < b->sport)
1129 * Special form of strcmp which can cope with NULL inputs. NULL is
1130 * defined to sort before even the empty string.
1132 static int nullstrcmp(const char *a, const char *b)
1134 if (a == NULL && b == NULL)
1140 return strcmp(a, b);
1143 static int ssh_portcmp(void *av, void *bv)
1145 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1146 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1148 if (a->type > b->type)
1150 if (a->type < b->type)
1152 if (a->addressfamily > b->addressfamily)
1154 if (a->addressfamily < b->addressfamily)
1156 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1157 return i < 0 ? -1 : +1;
1158 if (a->sport > b->sport)
1160 if (a->sport < b->sport)
1162 if (a->type != 'D') {
1163 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1164 return i < 0 ? -1 : +1;
1165 if (a->dport > b->dport)
1167 if (a->dport < b->dport)
1173 static int alloc_channel_id(Ssh ssh)
1175 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1176 unsigned low, high, mid;
1178 struct ssh_channel *c;
1181 * First-fit allocation of channel numbers: always pick the
1182 * lowest unused one. To do this, binary-search using the
1183 * counted B-tree to find the largest channel ID which is in a
1184 * contiguous sequence from the beginning. (Precisely
1185 * everything in that sequence must have ID equal to its tree
1186 * index plus CHANNEL_NUMBER_OFFSET.)
1188 tsize = count234(ssh->channels);
1192 while (high - low > 1) {
1193 mid = (high + low) / 2;
1194 c = index234(ssh->channels, mid);
1195 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1196 low = mid; /* this one is fine */
1198 high = mid; /* this one is past it */
1201 * Now low points to either -1, or the tree index of the
1202 * largest ID in the initial sequence.
1205 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1206 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1208 return low + 1 + CHANNEL_NUMBER_OFFSET;
1211 static void c_write_stderr(int trusted, const char *buf, int len)
1214 for (i = 0; i < len; i++)
1215 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1216 fputc(buf[i], stderr);
1219 static void c_write(Ssh ssh, const char *buf, int len)
1221 if (flags & FLAG_STDERR)
1222 c_write_stderr(1, buf, len);
1224 from_backend(ssh->frontend, 1, buf, len);
1227 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1229 if (flags & FLAG_STDERR)
1230 c_write_stderr(0, buf, len);
1232 from_backend_untrusted(ssh->frontend, buf, len);
1235 static void c_write_str(Ssh ssh, const char *buf)
1237 c_write(ssh, buf, strlen(buf));
1240 static void ssh_free_packet(struct Packet *pkt)
1245 static struct Packet *ssh_new_packet(void)
1247 struct Packet *pkt = snew(struct Packet);
1249 pkt->body = pkt->data = NULL;
1251 pkt->logmode = PKTLOG_EMIT;
1259 * Collect incoming data in the incoming packet buffer.
1260 * Decipher and verify the packet when it is completely read.
1261 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1262 * Update the *data and *datalen variables.
1263 * Return a Packet structure when a packet is completed.
1265 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1267 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1269 crBegin(ssh->ssh1_rdpkt_crstate);
1271 st->pktin = ssh_new_packet();
1273 st->pktin->type = 0;
1274 st->pktin->length = 0;
1276 for (st->i = st->len = 0; st->i < 4; st->i++) {
1277 while ((*datalen) == 0)
1279 st->len = (st->len << 8) + **data;
1280 (*data)++, (*datalen)--;
1283 st->pad = 8 - (st->len % 8);
1284 st->biglen = st->len + st->pad;
1285 st->pktin->length = st->len - 5;
1287 if (st->biglen < 0) {
1288 bombout(("Extremely large packet length from server suggests"
1289 " data stream corruption"));
1290 ssh_free_packet(st->pktin);
1294 st->pktin->maxlen = st->biglen;
1295 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1297 st->to_read = st->biglen;
1298 st->p = st->pktin->data;
1299 while (st->to_read > 0) {
1300 st->chunk = st->to_read;
1301 while ((*datalen) == 0)
1303 if (st->chunk > (*datalen))
1304 st->chunk = (*datalen);
1305 memcpy(st->p, *data, st->chunk);
1307 *datalen -= st->chunk;
1309 st->to_read -= st->chunk;
1312 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1313 st->biglen, NULL)) {
1314 bombout(("Network attack (CRC compensation) detected!"));
1315 ssh_free_packet(st->pktin);
1320 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1322 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1323 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1324 if (st->gotcrc != st->realcrc) {
1325 bombout(("Incorrect CRC received on packet"));
1326 ssh_free_packet(st->pktin);
1330 st->pktin->body = st->pktin->data + st->pad + 1;
1331 st->pktin->savedpos = 0;
1333 if (ssh->v1_compressing) {
1334 unsigned char *decompblk;
1336 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1337 st->pktin->body - 1, st->pktin->length + 1,
1338 &decompblk, &decomplen)) {
1339 bombout(("Zlib decompression encountered invalid data"));
1340 ssh_free_packet(st->pktin);
1344 if (st->pktin->maxlen < st->pad + decomplen) {
1345 st->pktin->maxlen = st->pad + decomplen;
1346 st->pktin->data = sresize(st->pktin->data,
1347 st->pktin->maxlen + APIEXTRA,
1349 st->pktin->body = st->pktin->data + st->pad + 1;
1352 memcpy(st->pktin->body - 1, decompblk, decomplen);
1354 st->pktin->length = decomplen - 1;
1357 st->pktin->type = st->pktin->body[-1];
1360 * Log incoming packet, possibly omitting sensitive fields.
1364 struct logblank_t blank;
1365 if (ssh->logomitdata) {
1366 int do_blank = FALSE, blank_prefix = 0;
1367 /* "Session data" packets - omit the data field */
1368 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1369 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1370 do_blank = TRUE; blank_prefix = 4;
1371 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1372 do_blank = TRUE; blank_prefix = 8;
1375 blank.offset = blank_prefix;
1376 blank.len = st->pktin->length;
1377 blank.type = PKTLOG_OMIT;
1381 log_packet(ssh->logctx,
1382 PKT_INCOMING, st->pktin->type,
1383 ssh1_pkt_type(st->pktin->type),
1384 st->pktin->body, st->pktin->length,
1385 nblanks, &blank, NULL);
1388 crFinish(st->pktin);
1391 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1393 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1395 crBegin(ssh->ssh2_rdpkt_crstate);
1397 st->pktin = ssh_new_packet();
1399 st->pktin->type = 0;
1400 st->pktin->length = 0;
1402 st->cipherblk = ssh->sccipher->blksize;
1405 if (st->cipherblk < 8)
1407 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1409 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1412 * When dealing with a CBC-mode cipher, we want to avoid the
1413 * possibility of an attacker's tweaking the ciphertext stream
1414 * so as to cause us to feed the same block to the block
1415 * cipher more than once and thus leak information
1416 * (VU#958563). The way we do this is not to take any
1417 * decisions on the basis of anything we've decrypted until
1418 * we've verified it with a MAC. That includes the packet
1419 * length, so we just read data and check the MAC repeatedly,
1420 * and when the MAC passes, see if the length we've got is
1424 /* May as well allocate the whole lot now. */
1425 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1428 /* Read an amount corresponding to the MAC. */
1429 for (st->i = 0; st->i < st->maclen; st->i++) {
1430 while ((*datalen) == 0)
1432 st->pktin->data[st->i] = *(*data)++;
1438 unsigned char seq[4];
1439 ssh->scmac->start(ssh->sc_mac_ctx);
1440 PUT_32BIT(seq, st->incoming_sequence);
1441 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1444 for (;;) { /* Once around this loop per cipher block. */
1445 /* Read another cipher-block's worth, and tack it onto the end. */
1446 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1447 while ((*datalen) == 0)
1449 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1452 /* Decrypt one more block (a little further back in the stream). */
1453 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1454 st->pktin->data + st->packetlen,
1456 /* Feed that block to the MAC. */
1457 ssh->scmac->bytes(ssh->sc_mac_ctx,
1458 st->pktin->data + st->packetlen, st->cipherblk);
1459 st->packetlen += st->cipherblk;
1460 /* See if that gives us a valid packet. */
1461 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1462 st->pktin->data + st->packetlen) &&
1463 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1466 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1467 bombout(("No valid incoming packet found"));
1468 ssh_free_packet(st->pktin);
1472 st->pktin->maxlen = st->packetlen + st->maclen;
1473 st->pktin->data = sresize(st->pktin->data,
1474 st->pktin->maxlen + APIEXTRA,
1477 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1480 * Acquire and decrypt the first block of the packet. This will
1481 * contain the length and padding details.
1483 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1484 while ((*datalen) == 0)
1486 st->pktin->data[st->i] = *(*data)++;
1491 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1492 st->pktin->data, st->cipherblk);
1495 * Now get the length figure.
1497 st->len = toint(GET_32BIT(st->pktin->data));
1500 * _Completely_ silly lengths should be stomped on before they
1501 * do us any more damage.
1503 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1504 (st->len + 4) % st->cipherblk != 0) {
1505 bombout(("Incoming packet was garbled on decryption"));
1506 ssh_free_packet(st->pktin);
1511 * So now we can work out the total packet length.
1513 st->packetlen = st->len + 4;
1516 * Allocate memory for the rest of the packet.
1518 st->pktin->maxlen = st->packetlen + st->maclen;
1519 st->pktin->data = sresize(st->pktin->data,
1520 st->pktin->maxlen + APIEXTRA,
1524 * Read and decrypt the remainder of the packet.
1526 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1528 while ((*datalen) == 0)
1530 st->pktin->data[st->i] = *(*data)++;
1533 /* Decrypt everything _except_ the MAC. */
1535 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1536 st->pktin->data + st->cipherblk,
1537 st->packetlen - st->cipherblk);
1543 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1544 st->len + 4, st->incoming_sequence)) {
1545 bombout(("Incorrect MAC received on packet"));
1546 ssh_free_packet(st->pktin);
1550 /* Get and sanity-check the amount of random padding. */
1551 st->pad = st->pktin->data[4];
1552 if (st->pad < 4 || st->len - st->pad < 1) {
1553 bombout(("Invalid padding length on received packet"));
1554 ssh_free_packet(st->pktin);
1558 * This enables us to deduce the payload length.
1560 st->payload = st->len - st->pad - 1;
1562 st->pktin->length = st->payload + 5;
1563 st->pktin->encrypted_len = st->packetlen;
1565 st->pktin->sequence = st->incoming_sequence++;
1568 * Decompress packet payload.
1571 unsigned char *newpayload;
1574 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1575 st->pktin->data + 5, st->pktin->length - 5,
1576 &newpayload, &newlen)) {
1577 if (st->pktin->maxlen < newlen + 5) {
1578 st->pktin->maxlen = newlen + 5;
1579 st->pktin->data = sresize(st->pktin->data,
1580 st->pktin->maxlen + APIEXTRA,
1583 st->pktin->length = 5 + newlen;
1584 memcpy(st->pktin->data + 5, newpayload, newlen);
1589 st->pktin->savedpos = 6;
1590 st->pktin->body = st->pktin->data;
1591 st->pktin->type = st->pktin->data[5];
1594 * Log incoming packet, possibly omitting sensitive fields.
1598 struct logblank_t blank;
1599 if (ssh->logomitdata) {
1600 int do_blank = FALSE, blank_prefix = 0;
1601 /* "Session data" packets - omit the data field */
1602 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1603 do_blank = TRUE; blank_prefix = 8;
1604 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1605 do_blank = TRUE; blank_prefix = 12;
1608 blank.offset = blank_prefix;
1609 blank.len = (st->pktin->length-6) - blank_prefix;
1610 blank.type = PKTLOG_OMIT;
1614 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1615 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1617 st->pktin->data+6, st->pktin->length-6,
1618 nblanks, &blank, &st->pktin->sequence);
1621 crFinish(st->pktin);
1624 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1626 int pad, biglen, i, pktoffs;
1630 * XXX various versions of SC (including 8.8.4) screw up the
1631 * register allocation in this function and use the same register
1632 * (D6) for len and as a temporary, with predictable results. The
1633 * following sledgehammer prevents this.
1640 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1641 ssh1_pkt_type(pkt->data[12]),
1642 pkt->body, pkt->length - (pkt->body - pkt->data),
1643 pkt->nblanks, pkt->blanks, NULL);
1644 sfree(pkt->blanks); pkt->blanks = NULL;
1647 if (ssh->v1_compressing) {
1648 unsigned char *compblk;
1650 zlib_compress_block(ssh->cs_comp_ctx,
1651 pkt->data + 12, pkt->length - 12,
1652 &compblk, &complen);
1653 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1654 memcpy(pkt->data + 12, compblk, complen);
1656 pkt->length = complen + 12;
1659 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1661 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1662 pad = 8 - (len % 8);
1664 biglen = len + pad; /* len(padding+type+data+CRC) */
1666 for (i = pktoffs; i < 4+8; i++)
1667 pkt->data[i] = random_byte();
1668 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1669 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1670 PUT_32BIT(pkt->data + pktoffs, len);
1673 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1674 pkt->data + pktoffs + 4, biglen);
1676 if (offset_p) *offset_p = pktoffs;
1677 return biglen + 4; /* len(length+padding+type+data+CRC) */
1680 static int s_write(Ssh ssh, void *data, int len)
1683 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1685 return sk_write(ssh->s, (char *)data, len);
1688 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1690 int len, backlog, offset;
1691 len = s_wrpkt_prepare(ssh, pkt, &offset);
1692 backlog = s_write(ssh, pkt->data + offset, len);
1693 if (backlog > SSH_MAX_BACKLOG)
1694 ssh_throttle_all(ssh, 1, backlog);
1695 ssh_free_packet(pkt);
1698 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1701 len = s_wrpkt_prepare(ssh, pkt, &offset);
1702 if (ssh->deferred_len + len > ssh->deferred_size) {
1703 ssh->deferred_size = ssh->deferred_len + len + 128;
1704 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1708 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1709 pkt->data + offset, len);
1710 ssh->deferred_len += len;
1711 ssh_free_packet(pkt);
1715 * Construct a SSH-1 packet with the specified contents.
1716 * (This all-at-once interface used to be the only one, but now SSH-1
1717 * packets can also be constructed incrementally.)
1719 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1725 pkt = ssh1_pkt_init(pkttype);
1727 while ((argtype = va_arg(ap, int)) != PKT_END) {
1728 unsigned char *argp, argchar;
1730 unsigned long argint;
1733 /* Actual fields in the packet */
1735 argint = va_arg(ap, int);
1736 ssh_pkt_adduint32(pkt, argint);
1739 argchar = (unsigned char) va_arg(ap, int);
1740 ssh_pkt_addbyte(pkt, argchar);
1743 argp = va_arg(ap, unsigned char *);
1744 arglen = va_arg(ap, int);
1745 ssh_pkt_adddata(pkt, argp, arglen);
1748 sargp = va_arg(ap, char *);
1749 ssh_pkt_addstring(pkt, sargp);
1752 bn = va_arg(ap, Bignum);
1753 ssh1_pkt_addmp(pkt, bn);
1755 /* Tokens for modifications to packet logging */
1757 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1760 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1763 end_log_omission(ssh, pkt);
1771 static void send_packet(Ssh ssh, int pkttype, ...)
1775 va_start(ap, pkttype);
1776 pkt = construct_packet(ssh, pkttype, ap);
1781 static void defer_packet(Ssh ssh, int pkttype, ...)
1785 va_start(ap, pkttype);
1786 pkt = construct_packet(ssh, pkttype, ap);
1788 s_wrpkt_defer(ssh, pkt);
1791 static int ssh_versioncmp(char *a, char *b)
1794 unsigned long av, bv;
1796 av = strtoul(a, &ae, 10);
1797 bv = strtoul(b, &be, 10);
1799 return (av < bv ? -1 : +1);
1804 av = strtoul(ae, &ae, 10);
1805 bv = strtoul(be, &be, 10);
1807 return (av < bv ? -1 : +1);
1812 * Utility routines for putting an SSH-protocol `string' and
1813 * `uint32' into a hash state.
1815 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1817 unsigned char lenblk[4];
1818 PUT_32BIT(lenblk, len);
1819 h->bytes(s, lenblk, 4);
1820 h->bytes(s, str, len);
1823 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1825 unsigned char intblk[4];
1826 PUT_32BIT(intblk, i);
1827 h->bytes(s, intblk, 4);
1831 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1833 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1835 if (pkt->maxlen < length) {
1836 unsigned char *body = pkt->body;
1837 int offset = body ? body - pkt->data : 0;
1838 pkt->maxlen = length + 256;
1839 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1840 if (body) pkt->body = pkt->data + offset;
1843 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
1845 if (pkt->logmode != PKTLOG_EMIT) {
1847 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1849 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1850 (pkt->body - pkt->data);
1851 pkt->blanks[pkt->nblanks-1].len = len;
1852 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1855 ssh_pkt_ensure(pkt, pkt->length);
1856 memcpy(pkt->data + pkt->length - len, data, len);
1858 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1860 ssh_pkt_adddata(pkt, &byte, 1);
1862 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1864 ssh_pkt_adddata(pkt, &value, 1);
1866 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1869 PUT_32BIT(x, value);
1870 ssh_pkt_adddata(pkt, x, 4);
1872 static void ssh_pkt_addstring_start(struct Packet *pkt)
1874 ssh_pkt_adduint32(pkt, 0);
1875 pkt->savedpos = pkt->length;
1877 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
1879 ssh_pkt_adddata(pkt, data, strlen(data));
1880 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1882 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
1885 ssh_pkt_adddata(pkt, data, len);
1886 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1888 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
1890 ssh_pkt_addstring_start(pkt);
1891 ssh_pkt_addstring_str(pkt, data);
1893 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1895 int len = ssh1_bignum_length(b);
1896 unsigned char *data = snewn(len, unsigned char);
1897 (void) ssh1_write_bignum(data, b);
1898 ssh_pkt_adddata(pkt, data, len);
1901 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1904 int i, n = (bignum_bitcount(b) + 7) / 8;
1905 p = snewn(n + 1, unsigned char);
1907 for (i = 1; i <= n; i++)
1908 p[i] = bignum_byte(b, n - i);
1910 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1912 memmove(p, p + i, n + 1 - i);
1916 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1920 p = ssh2_mpint_fmt(b, &len);
1921 ssh_pkt_addstring_start(pkt);
1922 ssh_pkt_addstring_data(pkt, (char *)p, len);
1926 static struct Packet *ssh1_pkt_init(int pkt_type)
1928 struct Packet *pkt = ssh_new_packet();
1929 pkt->length = 4 + 8; /* space for length + max padding */
1930 ssh_pkt_addbyte(pkt, pkt_type);
1931 pkt->body = pkt->data + pkt->length;
1935 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1936 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1937 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1938 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1939 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1940 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1941 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1942 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1943 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1945 static struct Packet *ssh2_pkt_init(int pkt_type)
1947 struct Packet *pkt = ssh_new_packet();
1948 pkt->length = 5; /* space for packet length + padding length */
1950 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1951 pkt->body = pkt->data + pkt->length; /* after packet type */
1956 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1957 * put the MAC on it. Final packet, ready to be sent, is stored in
1958 * pkt->data. Total length is returned.
1960 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1962 int cipherblk, maclen, padding, i;
1965 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1966 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1967 pkt->body, pkt->length - (pkt->body - pkt->data),
1968 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
1969 sfree(pkt->blanks); pkt->blanks = NULL;
1973 * Compress packet payload.
1976 unsigned char *newpayload;
1979 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1981 &newpayload, &newlen)) {
1983 ssh2_pkt_adddata(pkt, newpayload, newlen);
1989 * Add padding. At least four bytes, and must also bring total
1990 * length (minus MAC) up to a multiple of the block size.
1991 * If pkt->forcepad is set, make sure the packet is at least that size
1994 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1995 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1997 if (pkt->length + padding < pkt->forcepad)
1998 padding = pkt->forcepad - pkt->length;
2000 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
2001 assert(padding <= 255);
2002 maclen = ssh->csmac ? ssh->csmac->len : 0;
2003 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
2004 pkt->data[4] = padding;
2005 for (i = 0; i < padding; i++)
2006 pkt->data[pkt->length + i] = random_byte();
2007 PUT_32BIT(pkt->data, pkt->length + padding - 4);
2009 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2010 pkt->length + padding,
2011 ssh->v2_outgoing_sequence);
2012 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2015 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2016 pkt->data, pkt->length + padding);
2018 pkt->encrypted_len = pkt->length + padding;
2020 /* Ready-to-send packet starts at pkt->data. We return length. */
2021 return pkt->length + padding + maclen;
2025 * Routines called from the main SSH code to send packets. There
2026 * are quite a few of these, because we have two separate
2027 * mechanisms for delaying the sending of packets:
2029 * - In order to send an IGNORE message and a password message in
2030 * a single fixed-length blob, we require the ability to
2031 * concatenate the encrypted forms of those two packets _into_ a
2032 * single blob and then pass it to our <network.h> transport
2033 * layer in one go. Hence, there's a deferment mechanism which
2034 * works after packet encryption.
2036 * - In order to avoid sending any connection-layer messages
2037 * during repeat key exchange, we have to queue up any such
2038 * outgoing messages _before_ they are encrypted (and in
2039 * particular before they're allocated sequence numbers), and
2040 * then send them once we've finished.
2042 * I call these mechanisms `defer' and `queue' respectively, so as
2043 * to distinguish them reasonably easily.
2045 * The functions send_noqueue() and defer_noqueue() free the packet
2046 * structure they are passed. Every outgoing packet goes through
2047 * precisely one of these functions in its life; packets passed to
2048 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2049 * these or get queued, and then when the queue is later emptied
2050 * the packets are all passed to defer_noqueue().
2052 * When using a CBC-mode cipher, it's necessary to ensure that an
2053 * attacker can't provide data to be encrypted using an IV that they
2054 * know. We ensure this by prefixing each packet that might contain
2055 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2056 * mechanism, so in this case send_noqueue() ends up redirecting to
2057 * defer_noqueue(). If you don't like this inefficiency, don't use
2061 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2062 static void ssh_pkt_defersend(Ssh);
2065 * Send an SSH-2 packet immediately, without queuing or deferring.
2067 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2071 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2072 /* We need to send two packets, so use the deferral mechanism. */
2073 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2074 ssh_pkt_defersend(ssh);
2077 len = ssh2_pkt_construct(ssh, pkt);
2078 backlog = s_write(ssh, pkt->data, len);
2079 if (backlog > SSH_MAX_BACKLOG)
2080 ssh_throttle_all(ssh, 1, backlog);
2082 ssh->outgoing_data_size += pkt->encrypted_len;
2083 if (!ssh->kex_in_progress &&
2084 ssh->max_data_size != 0 &&
2085 ssh->outgoing_data_size > ssh->max_data_size)
2086 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2088 ssh_free_packet(pkt);
2092 * Defer an SSH-2 packet.
2094 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2097 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2098 ssh->deferred_len == 0 && !noignore &&
2099 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2101 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2102 * get encrypted with a known IV.
2104 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2105 ssh2_pkt_addstring_start(ipkt);
2106 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2108 len = ssh2_pkt_construct(ssh, pkt);
2109 if (ssh->deferred_len + len > ssh->deferred_size) {
2110 ssh->deferred_size = ssh->deferred_len + len + 128;
2111 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2115 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
2116 ssh->deferred_len += len;
2117 ssh->deferred_data_size += pkt->encrypted_len;
2118 ssh_free_packet(pkt);
2122 * Queue an SSH-2 packet.
2124 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2126 assert(ssh->queueing);
2128 if (ssh->queuelen >= ssh->queuesize) {
2129 ssh->queuesize = ssh->queuelen + 32;
2130 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2133 ssh->queue[ssh->queuelen++] = pkt;
2137 * Either queue or send a packet, depending on whether queueing is
2140 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2143 ssh2_pkt_queue(ssh, pkt);
2145 ssh2_pkt_send_noqueue(ssh, pkt);
2149 * Either queue or defer a packet, depending on whether queueing is
2152 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2155 ssh2_pkt_queue(ssh, pkt);
2157 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2161 * Send the whole deferred data block constructed by
2162 * ssh2_pkt_defer() or SSH-1's defer_packet().
2164 * The expected use of the defer mechanism is that you call
2165 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2166 * not currently queueing, this simply sets up deferred_send_data
2167 * and then sends it. If we _are_ currently queueing, the calls to
2168 * ssh2_pkt_defer() put the deferred packets on to the queue
2169 * instead, and therefore ssh_pkt_defersend() has no deferred data
2170 * to send. Hence, there's no need to make it conditional on
2173 static void ssh_pkt_defersend(Ssh ssh)
2176 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2177 ssh->deferred_len = ssh->deferred_size = 0;
2178 sfree(ssh->deferred_send_data);
2179 ssh->deferred_send_data = NULL;
2180 if (backlog > SSH_MAX_BACKLOG)
2181 ssh_throttle_all(ssh, 1, backlog);
2183 ssh->outgoing_data_size += ssh->deferred_data_size;
2184 if (!ssh->kex_in_progress &&
2185 ssh->max_data_size != 0 &&
2186 ssh->outgoing_data_size > ssh->max_data_size)
2187 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2188 ssh->deferred_data_size = 0;
2192 * Send a packet whose length needs to be disguised (typically
2193 * passwords or keyboard-interactive responses).
2195 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2201 * The simplest way to do this is to adjust the
2202 * variable-length padding field in the outgoing packet.
2204 * Currently compiled out, because some Cisco SSH servers
2205 * don't like excessively padded packets (bah, why's it
2208 pkt->forcepad = padsize;
2209 ssh2_pkt_send(ssh, pkt);
2214 * If we can't do that, however, an alternative approach is
2215 * to use the pkt_defer mechanism to bundle the packet
2216 * tightly together with an SSH_MSG_IGNORE such that their
2217 * combined length is a constant. So first we construct the
2218 * final form of this packet and defer its sending.
2220 ssh2_pkt_defer(ssh, pkt);
2223 * Now construct an SSH_MSG_IGNORE which includes a string
2224 * that's an exact multiple of the cipher block size. (If
2225 * the cipher is NULL so that the block size is
2226 * unavailable, we don't do this trick at all, because we
2227 * gain nothing by it.)
2229 if (ssh->cscipher &&
2230 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2233 stringlen = (256 - ssh->deferred_len);
2234 stringlen += ssh->cscipher->blksize - 1;
2235 stringlen -= (stringlen % ssh->cscipher->blksize);
2238 * Temporarily disable actual compression, so we
2239 * can guarantee to get this string exactly the
2240 * length we want it. The compression-disabling
2241 * routine should return an integer indicating how
2242 * many bytes we should adjust our string length
2246 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2248 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2249 ssh2_pkt_addstring_start(pkt);
2250 for (i = 0; i < stringlen; i++) {
2251 char c = (char) random_byte();
2252 ssh2_pkt_addstring_data(pkt, &c, 1);
2254 ssh2_pkt_defer(ssh, pkt);
2256 ssh_pkt_defersend(ssh);
2261 * Send all queued SSH-2 packets. We send them by means of
2262 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2263 * packets that needed to be lumped together.
2265 static void ssh2_pkt_queuesend(Ssh ssh)
2269 assert(!ssh->queueing);
2271 for (i = 0; i < ssh->queuelen; i++)
2272 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2275 ssh_pkt_defersend(ssh);
2279 void bndebug(char *string, Bignum b)
2283 p = ssh2_mpint_fmt(b, &len);
2284 debug(("%s", string));
2285 for (i = 0; i < len; i++)
2286 debug((" %02x", p[i]));
2292 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2296 p = ssh2_mpint_fmt(b, &len);
2297 hash_string(h, s, p, len);
2302 * Packet decode functions for both SSH-1 and SSH-2.
2304 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2306 unsigned long value;
2307 if (pkt->length - pkt->savedpos < 4)
2308 return 0; /* arrgh, no way to decline (FIXME?) */
2309 value = GET_32BIT(pkt->body + pkt->savedpos);
2313 static int ssh2_pkt_getbool(struct Packet *pkt)
2315 unsigned long value;
2316 if (pkt->length - pkt->savedpos < 1)
2317 return 0; /* arrgh, no way to decline (FIXME?) */
2318 value = pkt->body[pkt->savedpos] != 0;
2322 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2327 if (pkt->length - pkt->savedpos < 4)
2329 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2334 if (pkt->length - pkt->savedpos < *length)
2336 *p = (char *)(pkt->body + pkt->savedpos);
2337 pkt->savedpos += *length;
2339 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2341 if (pkt->length - pkt->savedpos < length)
2343 pkt->savedpos += length;
2344 return pkt->body + (pkt->savedpos - length);
2346 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2347 unsigned char **keystr)
2351 j = makekey(pkt->body + pkt->savedpos,
2352 pkt->length - pkt->savedpos,
2359 assert(pkt->savedpos < pkt->length);
2363 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2368 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2369 pkt->length - pkt->savedpos, &b);
2377 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2383 ssh_pkt_getstring(pkt, &p, &length);
2388 b = bignum_from_bytes((unsigned char *)p, length);
2393 * Helper function to add an SSH-2 signature blob to a packet.
2394 * Expects to be shown the public key blob as well as the signature
2395 * blob. Normally works just like ssh2_pkt_addstring, but will
2396 * fiddle with the signature packet if necessary for
2397 * BUG_SSH2_RSA_PADDING.
2399 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2400 void *pkblob_v, int pkblob_len,
2401 void *sigblob_v, int sigblob_len)
2403 unsigned char *pkblob = (unsigned char *)pkblob_v;
2404 unsigned char *sigblob = (unsigned char *)sigblob_v;
2406 /* dmemdump(pkblob, pkblob_len); */
2407 /* dmemdump(sigblob, sigblob_len); */
2410 * See if this is in fact an ssh-rsa signature and a buggy
2411 * server; otherwise we can just do this the easy way.
2413 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2414 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2415 int pos, len, siglen;
2418 * Find the byte length of the modulus.
2421 pos = 4+7; /* skip over "ssh-rsa" */
2422 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2423 if (len < 0 || len > pkblob_len - pos - 4)
2425 pos += 4 + len; /* skip over exponent */
2426 if (pkblob_len - pos < 4)
2428 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2429 if (len < 0 || len > pkblob_len - pos - 4)
2431 pos += 4; /* find modulus itself */
2432 while (len > 0 && pkblob[pos] == 0)
2434 /* debug(("modulus length is %d\n", len)); */
2437 * Now find the signature integer.
2439 pos = 4+7; /* skip over "ssh-rsa" */
2440 if (sigblob_len < pos+4)
2442 siglen = toint(GET_32BIT(sigblob+pos));
2443 if (siglen != sigblob_len - pos - 4)
2445 /* debug(("signature length is %d\n", siglen)); */
2447 if (len != siglen) {
2448 unsigned char newlen[4];
2449 ssh2_pkt_addstring_start(pkt);
2450 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2451 /* dmemdump(sigblob, pos); */
2452 pos += 4; /* point to start of actual sig */
2453 PUT_32BIT(newlen, len);
2454 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2455 /* dmemdump(newlen, 4); */
2457 while (len-- > siglen) {
2458 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2459 /* dmemdump(newlen, 1); */
2461 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2462 /* dmemdump(sigblob+pos, siglen); */
2466 /* Otherwise fall through and do it the easy way. We also come
2467 * here as a fallback if we discover above that the key blob
2468 * is misformatted in some way. */
2472 ssh2_pkt_addstring_start(pkt);
2473 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2477 * Examine the remote side's version string and compare it against
2478 * a list of known buggy implementations.
2480 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2482 char *imp; /* pointer to implementation part */
2484 imp += strcspn(imp, "-");
2486 imp += strcspn(imp, "-");
2489 ssh->remote_bugs = 0;
2492 * General notes on server version strings:
2493 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2494 * here -- in particular, we've heard of one that's perfectly happy
2495 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2496 * so we can't distinguish them.
2498 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2499 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2500 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2501 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2502 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2503 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2505 * These versions don't support SSH1_MSG_IGNORE, so we have
2506 * to use a different defence against password length
2509 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2510 logevent("We believe remote version has SSH-1 ignore bug");
2513 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2514 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2515 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2517 * These versions need a plain password sent; they can't
2518 * handle having a null and a random length of data after
2521 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2522 logevent("We believe remote version needs a plain SSH-1 password");
2525 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2526 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2527 (!strcmp(imp, "Cisco-1.25")))) {
2529 * These versions apparently have no clue whatever about
2530 * RSA authentication and will panic and die if they see
2531 * an AUTH_RSA message.
2533 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2534 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2537 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2538 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2539 !wc_match("* VShell", imp) &&
2540 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2541 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2542 wc_match("2.1 *", imp)))) {
2544 * These versions have the HMAC bug.
2546 ssh->remote_bugs |= BUG_SSH2_HMAC;
2547 logevent("We believe remote version has SSH-2 HMAC bug");
2550 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2551 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2552 !wc_match("* VShell", imp) &&
2553 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2555 * These versions have the key-derivation bug (failing to
2556 * include the literal shared secret in the hashes that
2557 * generate the keys).
2559 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2560 logevent("We believe remote version has SSH-2 key-derivation bug");
2563 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2564 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2565 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2566 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2568 * These versions have the SSH-2 RSA padding bug.
2570 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2571 logevent("We believe remote version has SSH-2 RSA padding bug");
2574 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2575 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2576 wc_match("OpenSSH_2.[0-2]*", imp))) {
2578 * These versions have the SSH-2 session-ID bug in
2579 * public-key authentication.
2581 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2582 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2585 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2586 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2587 (wc_match("DigiSSH_2.0", imp) ||
2588 wc_match("OpenSSH_2.[0-4]*", imp) ||
2589 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2590 wc_match("Sun_SSH_1.0", imp) ||
2591 wc_match("Sun_SSH_1.0.1", imp) ||
2592 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2593 wc_match("WeOnlyDo-*", imp)))) {
2595 * These versions have the SSH-2 rekey bug.
2597 ssh->remote_bugs |= BUG_SSH2_REKEY;
2598 logevent("We believe remote version has SSH-2 rekey bug");
2601 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2602 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2603 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2604 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2606 * This version ignores our makpkt and needs to be throttled.
2608 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2609 logevent("We believe remote version ignores SSH-2 maximum packet size");
2612 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2614 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2615 * none detected automatically.
2617 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2618 logevent("We believe remote version has SSH-2 ignore bug");
2621 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2623 * Servers that don't support our winadj request for one
2624 * reason or another. Currently, none detected automatically.
2626 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2627 logevent("We believe remote version has winadj bug");
2632 * The `software version' part of an SSH version string is required
2633 * to contain no spaces or minus signs.
2635 static void ssh_fix_verstring(char *str)
2637 /* Eat "SSH-<protoversion>-". */
2638 assert(*str == 'S'); str++;
2639 assert(*str == 'S'); str++;
2640 assert(*str == 'H'); str++;
2641 assert(*str == '-'); str++;
2642 while (*str && *str != '-') str++;
2643 assert(*str == '-'); str++;
2645 /* Convert minus signs and spaces in the remaining string into
2648 if (*str == '-' || *str == ' ')
2655 * Send an appropriate SSH version string.
2657 static void ssh_send_verstring(Ssh ssh, char *svers)
2661 if (ssh->version == 2) {
2663 * Construct a v2 version string.
2665 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2668 * Construct a v1 version string.
2670 verstring = dupprintf("SSH-%s-%s\012",
2671 (ssh_versioncmp(svers, "1.5") <= 0 ?
2676 ssh_fix_verstring(verstring);
2678 if (ssh->version == 2) {
2681 * Record our version string.
2683 len = strcspn(verstring, "\015\012");
2684 ssh->v_c = snewn(len + 1, char);
2685 memcpy(ssh->v_c, verstring, len);
2689 logeventf(ssh, "We claim version: %.*s",
2690 strcspn(verstring, "\015\012"), verstring);
2691 s_write(ssh, verstring, strlen(verstring));
2695 static int do_ssh_init(Ssh ssh, unsigned char c)
2697 struct do_ssh_init_state {
2706 crState(do_ssh_init_state);
2710 /* Search for a line beginning with the string "SSH-" in the input. */
2712 if (c != 'S') goto no;
2714 if (c != 'S') goto no;
2716 if (c != 'H') goto no;
2718 if (c != '-') goto no;
2727 s->vstring = snewn(s->vstrsize, char);
2728 strcpy(s->vstring, "SSH-");
2732 crReturn(1); /* get another char */
2733 if (s->vslen >= s->vstrsize - 1) {
2735 s->vstring = sresize(s->vstring, s->vstrsize, char);
2737 s->vstring[s->vslen++] = c;
2740 s->version[s->i] = '\0';
2742 } else if (s->i < sizeof(s->version) - 1)
2743 s->version[s->i++] = c;
2744 } else if (c == '\012')
2748 ssh->agentfwd_enabled = FALSE;
2749 ssh->rdpkt2_state.incoming_sequence = 0;
2751 s->vstring[s->vslen] = 0;
2752 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2753 logeventf(ssh, "Server version: %s", s->vstring);
2754 ssh_detect_bugs(ssh, s->vstring);
2757 * Decide which SSH protocol version to support.
2760 /* Anything strictly below "2.0" means protocol 1 is supported. */
2761 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2762 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2763 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2765 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2766 bombout(("SSH protocol version 1 required by user but not provided by server"));
2769 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2770 bombout(("SSH protocol version 2 required by user but not provided by server"));
2774 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2779 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2781 /* Send the version string, if we haven't already */
2782 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2783 ssh_send_verstring(ssh, s->version);
2785 if (ssh->version == 2) {
2788 * Record their version string.
2790 len = strcspn(s->vstring, "\015\012");
2791 ssh->v_s = snewn(len + 1, char);
2792 memcpy(ssh->v_s, s->vstring, len);
2796 * Initialise SSH-2 protocol.
2798 ssh->protocol = ssh2_protocol;
2799 ssh2_protocol_setup(ssh);
2800 ssh->s_rdpkt = ssh2_rdpkt;
2803 * Initialise SSH-1 protocol.
2805 ssh->protocol = ssh1_protocol;
2806 ssh1_protocol_setup(ssh);
2807 ssh->s_rdpkt = ssh1_rdpkt;
2809 if (ssh->version == 2)
2810 do_ssh2_transport(ssh, NULL, -1, NULL);
2812 update_specials_menu(ssh->frontend);
2813 ssh->state = SSH_STATE_BEFORE_SIZE;
2814 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
2821 static void ssh_process_incoming_data(Ssh ssh,
2822 unsigned char **data, int *datalen)
2824 struct Packet *pktin;
2826 pktin = ssh->s_rdpkt(ssh, data, datalen);
2828 ssh->protocol(ssh, NULL, 0, pktin);
2829 ssh_free_packet(pktin);
2833 static void ssh_queue_incoming_data(Ssh ssh,
2834 unsigned char **data, int *datalen)
2836 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2841 static void ssh_process_queued_incoming_data(Ssh ssh)
2844 unsigned char *data;
2847 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2848 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2852 while (!ssh->frozen && len > 0)
2853 ssh_process_incoming_data(ssh, &data, &len);
2856 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2860 static void ssh_set_frozen(Ssh ssh, int frozen)
2863 sk_set_frozen(ssh->s, frozen);
2864 ssh->frozen = frozen;
2867 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2869 /* Log raw data, if we're in that mode. */
2871 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2874 crBegin(ssh->ssh_gotdata_crstate);
2877 * To begin with, feed the characters one by one to the
2878 * protocol initialisation / selection function do_ssh_init().
2879 * When that returns 0, we're done with the initial greeting
2880 * exchange and can move on to packet discipline.
2883 int ret; /* need not be kept across crReturn */
2885 crReturnV; /* more data please */
2886 ret = do_ssh_init(ssh, *data);
2894 * We emerge from that loop when the initial negotiation is
2895 * over and we have selected an s_rdpkt function. Now pass
2896 * everything to s_rdpkt, and then pass the resulting packets
2897 * to the proper protocol handler.
2901 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2903 ssh_queue_incoming_data(ssh, &data, &datalen);
2904 /* This uses up all data and cannot cause anything interesting
2905 * to happen; indeed, for anything to happen at all, we must
2906 * return, so break out. */
2908 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2909 /* This uses up some or all data, and may freeze the
2911 ssh_process_queued_incoming_data(ssh);
2913 /* This uses up some or all data, and may freeze the
2915 ssh_process_incoming_data(ssh, &data, &datalen);
2917 /* FIXME this is probably EBW. */
2918 if (ssh->state == SSH_STATE_CLOSED)
2921 /* We're out of data. Go and get some more. */
2927 static int ssh_do_close(Ssh ssh, int notify_exit)
2930 struct ssh_channel *c;
2932 ssh->state = SSH_STATE_CLOSED;
2933 expire_timer_context(ssh);
2938 notify_remote_exit(ssh->frontend);
2943 * Now we must shut down any port- and X-forwarded channels going
2944 * through this connection.
2946 if (ssh->channels) {
2947 while (NULL != (c = index234(ssh->channels, 0))) {
2950 x11_close(c->u.x11.s);
2953 case CHAN_SOCKDATA_DORMANT:
2954 pfd_close(c->u.pfd.s);
2957 del234(ssh->channels, c); /* moving next one to index 0 */
2958 if (ssh->version == 2)
2959 bufchain_clear(&c->v.v2.outbuffer);
2964 * Go through port-forwardings, and close any associated
2965 * listening sockets.
2967 if (ssh->portfwds) {
2968 struct ssh_portfwd *pf;
2969 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2970 /* Dispose of any listening socket. */
2972 pfd_terminate(pf->local);
2973 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2976 freetree234(ssh->portfwds);
2977 ssh->portfwds = NULL;
2983 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2984 const char *error_msg, int error_code)
2986 Ssh ssh = (Ssh) plug;
2987 char addrbuf[256], *msg;
2989 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2992 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2994 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
3000 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
3003 Ssh ssh = (Ssh) plug;
3004 int need_notify = ssh_do_close(ssh, FALSE);
3007 if (!ssh->close_expected)
3008 error_msg = "Server unexpectedly closed network connection";
3010 error_msg = "Server closed network connection";
3013 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3017 notify_remote_exit(ssh->frontend);
3020 logevent(error_msg);
3021 if (!ssh->close_expected || !ssh->clean_exit)
3022 connection_fatal(ssh->frontend, "%s", error_msg);
3026 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3028 Ssh ssh = (Ssh) plug;
3029 ssh_gotdata(ssh, (unsigned char *)data, len);
3030 if (ssh->state == SSH_STATE_CLOSED) {
3031 ssh_do_close(ssh, TRUE);
3037 static void ssh_sent(Plug plug, int bufsize)
3039 Ssh ssh = (Ssh) plug;
3041 * If the send backlog on the SSH socket itself clears, we
3042 * should unthrottle the whole world if it was throttled.
3044 if (bufsize < SSH_MAX_BACKLOG)
3045 ssh_throttle_all(ssh, 0, bufsize);
3049 * Connect to specified host and port.
3050 * Returns an error message, or NULL on success.
3051 * Also places the canonical host name into `realhost'. It must be
3052 * freed by the caller.
3054 static const char *connect_to_host(Ssh ssh, char *host, int port,
3055 char **realhost, int nodelay, int keepalive)
3057 static const struct plug_function_table fn_table = {
3068 int addressfamily, sshprot;
3070 loghost = conf_get_str(ssh->conf, CONF_loghost);
3074 ssh->savedhost = dupstr(loghost);
3075 ssh->savedport = 22; /* default ssh port */
3078 * A colon suffix on savedhost also lets us affect
3081 * (FIXME: do something about IPv6 address literals here.)
3083 colon = strrchr(ssh->savedhost, ':');
3087 ssh->savedport = atoi(colon);
3090 ssh->savedhost = dupstr(host);
3092 port = 22; /* default ssh port */
3093 ssh->savedport = port;
3099 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3100 logeventf(ssh, "Looking up host \"%s\"%s", host,
3101 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3102 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3103 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3104 if ((err = sk_addr_error(addr)) != NULL) {
3108 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3113 ssh->fn = &fn_table;
3114 ssh->s = new_connection(addr, *realhost, port,
3115 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
3116 if ((err = sk_socket_error(ssh->s)) != NULL) {
3118 notify_remote_exit(ssh->frontend);
3123 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3124 * send the version string too.
3126 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3131 ssh_send_verstring(ssh, NULL);
3135 * loghost, if configured, overrides realhost.
3139 *realhost = dupstr(loghost);
3146 * Throttle or unthrottle the SSH connection.
3148 static void ssh_throttle_conn(Ssh ssh, int adjust)
3150 int old_count = ssh->conn_throttle_count;
3151 ssh->conn_throttle_count += adjust;
3152 assert(ssh->conn_throttle_count >= 0);
3153 if (ssh->conn_throttle_count && !old_count) {
3154 ssh_set_frozen(ssh, 1);
3155 } else if (!ssh->conn_throttle_count && old_count) {
3156 ssh_set_frozen(ssh, 0);
3161 * Throttle or unthrottle _all_ local data streams (for when sends
3162 * on the SSH connection itself back up).
3164 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3167 struct ssh_channel *c;
3169 if (enable == ssh->throttled_all)
3171 ssh->throttled_all = enable;
3172 ssh->overall_bufsize = bufsize;
3175 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3177 case CHAN_MAINSESSION:
3179 * This is treated separately, outside the switch.
3183 x11_override_throttle(c->u.x11.s, enable);
3186 /* Agent channels require no buffer management. */
3189 pfd_override_throttle(c->u.pfd.s, enable);
3195 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3197 Ssh ssh = (Ssh) sshv;
3199 ssh->agent_response = reply;
3200 ssh->agent_response_len = replylen;
3202 if (ssh->version == 1)
3203 do_ssh1_login(ssh, NULL, -1, NULL);
3205 do_ssh2_authconn(ssh, NULL, -1, NULL);
3208 static void ssh_dialog_callback(void *sshv, int ret)
3210 Ssh ssh = (Ssh) sshv;
3212 ssh->user_response = ret;
3214 if (ssh->version == 1)
3215 do_ssh1_login(ssh, NULL, -1, NULL);
3217 do_ssh2_transport(ssh, NULL, -1, NULL);
3220 * This may have unfrozen the SSH connection, so do a
3223 ssh_process_queued_incoming_data(ssh);
3226 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3228 struct ssh_channel *c = (struct ssh_channel *)cv;
3230 void *sentreply = reply;
3232 c->u.a.outstanding_requests--;
3234 /* Fake SSH_AGENT_FAILURE. */
3235 sentreply = "\0\0\0\1\5";
3238 if (ssh->version == 2) {
3239 ssh2_add_channel_data(c, sentreply, replylen);
3242 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3243 PKT_INT, c->remoteid,
3246 PKT_DATA, sentreply, replylen,
3253 * If we've already seen an incoming EOF but haven't sent an
3254 * outgoing one, this may be the moment to send it.
3256 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3257 sshfwd_write_eof(c);
3261 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3262 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3263 * => log `wire_reason'.
3265 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3266 int code, int clean_exit)
3270 client_reason = wire_reason;
3272 error = dupprintf("Disconnected: %s", client_reason);
3274 error = dupstr("Disconnected");
3276 if (ssh->version == 1) {
3277 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3279 } else if (ssh->version == 2) {
3280 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3281 ssh2_pkt_adduint32(pktout, code);
3282 ssh2_pkt_addstring(pktout, wire_reason);
3283 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3284 ssh2_pkt_send_noqueue(ssh, pktout);
3287 ssh->close_expected = TRUE;
3288 ssh->clean_exit = clean_exit;
3289 ssh_closing((Plug)ssh, error, 0, 0);
3294 * Handle the key exchange and user authentication phases.
3296 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3297 struct Packet *pktin)
3300 unsigned char cookie[8], *ptr;
3301 struct MD5Context md5c;
3302 struct do_ssh1_login_state {
3305 unsigned char *rsabuf, *keystr1, *keystr2;
3306 unsigned long supported_ciphers_mask, supported_auths_mask;
3307 int tried_publickey, tried_agent;
3308 int tis_auth_refused, ccard_auth_refused;
3309 unsigned char session_id[16];
3311 void *publickey_blob;
3312 int publickey_bloblen;
3313 char *publickey_comment;
3314 int publickey_encrypted;
3315 prompts_t *cur_prompt;
3318 unsigned char request[5], *response, *p;
3328 struct RSAKey servkey, hostkey;
3330 crState(do_ssh1_login_state);
3337 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3338 bombout(("Public key packet not received"));
3342 logevent("Received public keys");
3344 ptr = ssh_pkt_getdata(pktin, 8);
3346 bombout(("SSH-1 public key packet stopped before random cookie"));
3349 memcpy(cookie, ptr, 8);
3351 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3352 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3353 bombout(("Failed to read SSH-1 public keys from public key packet"));
3358 * Log the host key fingerprint.
3362 logevent("Host key fingerprint is:");
3363 strcpy(logmsg, " ");
3364 s->hostkey.comment = NULL;
3365 rsa_fingerprint(logmsg + strlen(logmsg),
3366 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3370 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3371 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3372 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3373 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3374 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3376 ssh->v1_local_protoflags =
3377 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3378 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3381 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3382 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3383 MD5Update(&md5c, cookie, 8);
3384 MD5Final(s->session_id, &md5c);
3386 for (i = 0; i < 32; i++)
3387 ssh->session_key[i] = random_byte();
3390 * Verify that the `bits' and `bytes' parameters match.
3392 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3393 s->servkey.bits > s->servkey.bytes * 8) {
3394 bombout(("SSH-1 public keys were badly formatted"));
3398 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3399 s->hostkey.bytes : s->servkey.bytes);
3401 s->rsabuf = snewn(s->len, unsigned char);
3404 * Verify the host key.
3408 * First format the key into a string.
3410 int len = rsastr_len(&s->hostkey);
3411 char fingerprint[100];
3412 char *keystr = snewn(len, char);
3413 rsastr_fmt(keystr, &s->hostkey);
3414 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3416 ssh_set_frozen(ssh, 1);
3417 s->dlgret = verify_ssh_host_key(ssh->frontend,
3418 ssh->savedhost, ssh->savedport,
3419 "rsa", keystr, fingerprint,
3420 ssh_dialog_callback, ssh);
3422 if (s->dlgret < 0) {
3426 bombout(("Unexpected data from server while waiting"
3427 " for user host key response"));
3430 } while (pktin || inlen > 0);
3431 s->dlgret = ssh->user_response;
3433 ssh_set_frozen(ssh, 0);
3435 if (s->dlgret == 0) {
3436 ssh_disconnect(ssh, "User aborted at host key verification",
3442 for (i = 0; i < 32; i++) {
3443 s->rsabuf[i] = ssh->session_key[i];
3445 s->rsabuf[i] ^= s->session_id[i];
3448 if (s->hostkey.bytes > s->servkey.bytes) {
3449 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3451 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3453 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3455 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3458 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3462 logevent("Encrypted session key");
3465 int cipher_chosen = 0, warn = 0;
3466 char *cipher_string = NULL;
3468 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3469 int next_cipher = conf_get_int_int(ssh->conf,
3470 CONF_ssh_cipherlist, i);
3471 if (next_cipher == CIPHER_WARN) {
3472 /* If/when we choose a cipher, warn about it */
3474 } else if (next_cipher == CIPHER_AES) {
3475 /* XXX Probably don't need to mention this. */
3476 logevent("AES not supported in SSH-1, skipping");
3478 switch (next_cipher) {
3479 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3480 cipher_string = "3DES"; break;
3481 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3482 cipher_string = "Blowfish"; break;
3483 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3484 cipher_string = "single-DES"; break;
3486 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3490 if (!cipher_chosen) {
3491 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3492 bombout(("Server violates SSH-1 protocol by not "
3493 "supporting 3DES encryption"));
3495 /* shouldn't happen */
3496 bombout(("No supported ciphers found"));
3500 /* Warn about chosen cipher if necessary. */
3502 ssh_set_frozen(ssh, 1);
3503 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3504 ssh_dialog_callback, ssh);
3505 if (s->dlgret < 0) {
3509 bombout(("Unexpected data from server while waiting"
3510 " for user response"));
3513 } while (pktin || inlen > 0);
3514 s->dlgret = ssh->user_response;
3516 ssh_set_frozen(ssh, 0);
3517 if (s->dlgret == 0) {
3518 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3525 switch (s->cipher_type) {
3526 case SSH_CIPHER_3DES:
3527 logevent("Using 3DES encryption");
3529 case SSH_CIPHER_DES:
3530 logevent("Using single-DES encryption");
3532 case SSH_CIPHER_BLOWFISH:
3533 logevent("Using Blowfish encryption");
3537 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3538 PKT_CHAR, s->cipher_type,
3539 PKT_DATA, cookie, 8,
3540 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3541 PKT_DATA, s->rsabuf, s->len,
3542 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3544 logevent("Trying to enable encryption...");
3548 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3549 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3551 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3552 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3553 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3555 ssh->crcda_ctx = crcda_make_context();
3556 logevent("Installing CRC compensation attack detector");
3558 if (s->servkey.modulus) {
3559 sfree(s->servkey.modulus);
3560 s->servkey.modulus = NULL;
3562 if (s->servkey.exponent) {
3563 sfree(s->servkey.exponent);
3564 s->servkey.exponent = NULL;
3566 if (s->hostkey.modulus) {
3567 sfree(s->hostkey.modulus);
3568 s->hostkey.modulus = NULL;
3570 if (s->hostkey.exponent) {
3571 sfree(s->hostkey.exponent);
3572 s->hostkey.exponent = NULL;
3576 if (pktin->type != SSH1_SMSG_SUCCESS) {
3577 bombout(("Encryption not successfully enabled"));
3581 logevent("Successfully started encryption");
3583 fflush(stdout); /* FIXME eh? */
3585 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3586 int ret; /* need not be kept over crReturn */
3587 s->cur_prompt = new_prompts(ssh->frontend);
3588 s->cur_prompt->to_server = TRUE;
3589 s->cur_prompt->name = dupstr("SSH login name");
3590 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3591 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3594 crWaitUntil(!pktin);
3595 ret = get_userpass_input(s->cur_prompt, in, inlen);
3600 * Failed to get a username. Terminate.
3602 free_prompts(s->cur_prompt);
3603 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3606 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3607 free_prompts(s->cur_prompt);
3610 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3612 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3614 if (flags & FLAG_INTERACTIVE &&
3615 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3616 c_write_str(ssh, userlog);
3617 c_write_str(ssh, "\r\n");
3625 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3626 /* We must not attempt PK auth. Pretend we've already tried it. */
3627 s->tried_publickey = s->tried_agent = 1;
3629 s->tried_publickey = s->tried_agent = 0;
3631 s->tis_auth_refused = s->ccard_auth_refused = 0;
3633 * Load the public half of any configured keyfile for later use.
3635 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3636 if (!filename_is_null(s->keyfile)) {
3638 logeventf(ssh, "Reading private key file \"%.150s\"",
3639 filename_to_str(s->keyfile));
3640 keytype = key_type(s->keyfile);
3641 if (keytype == SSH_KEYTYPE_SSH1) {
3643 if (rsakey_pubblob(s->keyfile,
3644 &s->publickey_blob, &s->publickey_bloblen,
3645 &s->publickey_comment, &error)) {
3646 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
3650 logeventf(ssh, "Unable to load private key (%s)", error);
3651 msgbuf = dupprintf("Unable to load private key file "
3652 "\"%.150s\" (%s)\r\n",
3653 filename_to_str(s->keyfile),
3655 c_write_str(ssh, msgbuf);
3657 s->publickey_blob = NULL;
3661 logeventf(ssh, "Unable to use this key file (%s)",
3662 key_type_to_str(keytype));
3663 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3665 filename_to_str(s->keyfile),
3666 key_type_to_str(keytype));
3667 c_write_str(ssh, msgbuf);
3669 s->publickey_blob = NULL;
3672 s->publickey_blob = NULL;
3674 while (pktin->type == SSH1_SMSG_FAILURE) {
3675 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3677 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
3679 * Attempt RSA authentication using Pageant.
3685 logevent("Pageant is running. Requesting keys.");
3687 /* Request the keys held by the agent. */
3688 PUT_32BIT(s->request, 1);
3689 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3690 if (!agent_query(s->request, 5, &r, &s->responselen,
3691 ssh_agent_callback, ssh)) {
3695 bombout(("Unexpected data from server while waiting"
3696 " for agent response"));
3699 } while (pktin || inlen > 0);
3700 r = ssh->agent_response;
3701 s->responselen = ssh->agent_response_len;
3703 s->response = (unsigned char *) r;
3704 if (s->response && s->responselen >= 5 &&
3705 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3706 s->p = s->response + 5;
3707 s->nkeys = toint(GET_32BIT(s->p));
3709 logeventf(ssh, "Pageant reported negative key count %d",
3714 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3715 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3716 unsigned char *pkblob = s->p;
3720 do { /* do while (0) to make breaking easy */
3721 n = ssh1_read_bignum
3722 (s->p, toint(s->responselen-(s->p-s->response)),
3727 n = ssh1_read_bignum
3728 (s->p, toint(s->responselen-(s->p-s->response)),
3733 if (s->responselen - (s->p-s->response) < 4)
3735 s->commentlen = toint(GET_32BIT(s->p));
3737 if (s->commentlen < 0 ||
3738 toint(s->responselen - (s->p-s->response)) <
3741 s->commentp = (char *)s->p;
3742 s->p += s->commentlen;
3746 logevent("Pageant key list packet was truncated");
3750 if (s->publickey_blob) {
3751 if (!memcmp(pkblob, s->publickey_blob,
3752 s->publickey_bloblen)) {
3753 logeventf(ssh, "Pageant key #%d matches "
3754 "configured key file", s->keyi);
3755 s->tried_publickey = 1;
3757 /* Skip non-configured key */
3760 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3761 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3762 PKT_BIGNUM, s->key.modulus, PKT_END);
3764 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3765 logevent("Key refused");
3768 logevent("Received RSA challenge");
3769 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3770 bombout(("Server's RSA challenge was badly formatted"));
3775 char *agentreq, *q, *ret;
3778 len = 1 + 4; /* message type, bit count */
3779 len += ssh1_bignum_length(s->key.exponent);
3780 len += ssh1_bignum_length(s->key.modulus);
3781 len += ssh1_bignum_length(s->challenge);
3782 len += 16; /* session id */
3783 len += 4; /* response format */
3784 agentreq = snewn(4 + len, char);
3785 PUT_32BIT(agentreq, len);
3787 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3788 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3790 q += ssh1_write_bignum(q, s->key.exponent);
3791 q += ssh1_write_bignum(q, s->key.modulus);
3792 q += ssh1_write_bignum(q, s->challenge);
3793 memcpy(q, s->session_id, 16);
3795 PUT_32BIT(q, 1); /* response format */
3796 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3797 ssh_agent_callback, ssh)) {
3802 bombout(("Unexpected data from server"
3803 " while waiting for agent"
3807 } while (pktin || inlen > 0);
3808 vret = ssh->agent_response;
3809 retlen = ssh->agent_response_len;
3814 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3815 logevent("Sending Pageant's response");
3816 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3817 PKT_DATA, ret + 5, 16,
3821 if (pktin->type == SSH1_SMSG_SUCCESS) {
3823 ("Pageant's response accepted");
3824 if (flags & FLAG_VERBOSE) {
3825 c_write_str(ssh, "Authenticated using"
3827 c_write(ssh, s->commentp,
3829 c_write_str(ssh, "\" from agent\r\n");
3834 ("Pageant's response not accepted");
3837 ("Pageant failed to answer challenge");
3841 logevent("No reply received from Pageant");
3844 freebn(s->key.exponent);
3845 freebn(s->key.modulus);
3846 freebn(s->challenge);
3851 if (s->publickey_blob && !s->tried_publickey)
3852 logevent("Configured key file not in Pageant");
3854 logevent("Failed to get reply from Pageant");
3859 if (s->publickey_blob && !s->tried_publickey) {
3861 * Try public key authentication with the specified
3864 int got_passphrase; /* need not be kept over crReturn */
3865 if (flags & FLAG_VERBOSE)
3866 c_write_str(ssh, "Trying public key authentication.\r\n");
3867 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3868 logeventf(ssh, "Trying public key \"%s\"",
3869 filename_to_str(s->keyfile));
3870 s->tried_publickey = 1;
3871 got_passphrase = FALSE;
3872 while (!got_passphrase) {
3874 * Get a passphrase, if necessary.
3876 char *passphrase = NULL; /* only written after crReturn */
3878 if (!s->publickey_encrypted) {
3879 if (flags & FLAG_VERBOSE)
3880 c_write_str(ssh, "No passphrase required.\r\n");
3883 int ret; /* need not be kept over crReturn */
3884 s->cur_prompt = new_prompts(ssh->frontend);
3885 s->cur_prompt->to_server = FALSE;
3886 s->cur_prompt->name = dupstr("SSH key passphrase");
3887 add_prompt(s->cur_prompt,
3888 dupprintf("Passphrase for key \"%.100s\": ",
3889 s->publickey_comment), FALSE);
3890 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3893 crWaitUntil(!pktin);
3894 ret = get_userpass_input(s->cur_prompt, in, inlen);
3898 /* Failed to get a passphrase. Terminate. */
3899 free_prompts(s->cur_prompt);
3900 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3904 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3905 free_prompts(s->cur_prompt);
3908 * Try decrypting key with passphrase.
3910 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3911 ret = loadrsakey(s->keyfile, &s->key, passphrase,
3914 smemclr(passphrase, strlen(passphrase));
3918 /* Correct passphrase. */
3919 got_passphrase = TRUE;
3920 } else if (ret == 0) {
3921 c_write_str(ssh, "Couldn't load private key from ");
3922 c_write_str(ssh, filename_to_str(s->keyfile));
3923 c_write_str(ssh, " (");
3924 c_write_str(ssh, error);
3925 c_write_str(ssh, ").\r\n");
3926 got_passphrase = FALSE;
3927 break; /* go and try something else */
3928 } else if (ret == -1) {
3929 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3930 got_passphrase = FALSE;
3933 assert(0 && "unexpected return from loadrsakey()");
3934 got_passphrase = FALSE; /* placate optimisers */
3938 if (got_passphrase) {
3941 * Send a public key attempt.
3943 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3944 PKT_BIGNUM, s->key.modulus, PKT_END);
3947 if (pktin->type == SSH1_SMSG_FAILURE) {
3948 c_write_str(ssh, "Server refused our public key.\r\n");
3949 continue; /* go and try something else */
3951 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3952 bombout(("Bizarre response to offer of public key"));
3958 unsigned char buffer[32];
3959 Bignum challenge, response;
3961 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3962 bombout(("Server's RSA challenge was badly formatted"));
3965 response = rsadecrypt(challenge, &s->key);
3966 freebn(s->key.private_exponent);/* burn the evidence */
3968 for (i = 0; i < 32; i++) {
3969 buffer[i] = bignum_byte(response, 31 - i);
3973 MD5Update(&md5c, buffer, 32);
3974 MD5Update(&md5c, s->session_id, 16);
3975 MD5Final(buffer, &md5c);
3977 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3978 PKT_DATA, buffer, 16, PKT_END);
3985 if (pktin->type == SSH1_SMSG_FAILURE) {
3986 if (flags & FLAG_VERBOSE)
3987 c_write_str(ssh, "Failed to authenticate with"
3988 " our public key.\r\n");
3989 continue; /* go and try something else */
3990 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3991 bombout(("Bizarre response to RSA authentication response"));
3995 break; /* we're through! */
4001 * Otherwise, try various forms of password-like authentication.
4003 s->cur_prompt = new_prompts(ssh->frontend);
4005 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4006 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
4007 !s->tis_auth_refused) {
4008 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
4009 logevent("Requested TIS authentication");
4010 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4012 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4013 logevent("TIS authentication declined");
4014 if (flags & FLAG_INTERACTIVE)
4015 c_write_str(ssh, "TIS authentication refused.\r\n");
4016 s->tis_auth_refused = 1;
4021 char *instr_suf, *prompt;
4023 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4025 bombout(("TIS challenge packet was badly formed"));
4028 logevent("Received TIS challenge");
4029 s->cur_prompt->to_server = TRUE;
4030 s->cur_prompt->name = dupstr("SSH TIS authentication");
4031 /* Prompt heuristic comes from OpenSSH */
4032 if (memchr(challenge, '\n', challengelen)) {
4033 instr_suf = dupstr("");
4034 prompt = dupprintf("%.*s", challengelen, challenge);
4036 instr_suf = dupprintf("%.*s", challengelen, challenge);
4037 prompt = dupstr("Response: ");
4039 s->cur_prompt->instruction =
4040 dupprintf("Using TIS authentication.%s%s",
4041 (*instr_suf) ? "\n" : "",
4043 s->cur_prompt->instr_reqd = TRUE;
4044 add_prompt(s->cur_prompt, prompt, FALSE);
4048 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4049 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4050 !s->ccard_auth_refused) {
4051 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4052 logevent("Requested CryptoCard authentication");
4053 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4055 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4056 logevent("CryptoCard authentication declined");
4057 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4058 s->ccard_auth_refused = 1;
4063 char *instr_suf, *prompt;
4065 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4067 bombout(("CryptoCard challenge packet was badly formed"));
4070 logevent("Received CryptoCard challenge");
4071 s->cur_prompt->to_server = TRUE;
4072 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4073 s->cur_prompt->name_reqd = FALSE;
4074 /* Prompt heuristic comes from OpenSSH */
4075 if (memchr(challenge, '\n', challengelen)) {
4076 instr_suf = dupstr("");
4077 prompt = dupprintf("%.*s", challengelen, challenge);
4079 instr_suf = dupprintf("%.*s", challengelen, challenge);
4080 prompt = dupstr("Response: ");
4082 s->cur_prompt->instruction =
4083 dupprintf("Using CryptoCard authentication.%s%s",
4084 (*instr_suf) ? "\n" : "",
4086 s->cur_prompt->instr_reqd = TRUE;
4087 add_prompt(s->cur_prompt, prompt, FALSE);
4091 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4092 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4093 bombout(("No supported authentication methods available"));
4096 s->cur_prompt->to_server = TRUE;
4097 s->cur_prompt->name = dupstr("SSH password");
4098 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4099 ssh->username, ssh->savedhost),
4104 * Show password prompt, having first obtained it via a TIS
4105 * or CryptoCard exchange if we're doing TIS or CryptoCard
4109 int ret; /* need not be kept over crReturn */
4110 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4113 crWaitUntil(!pktin);
4114 ret = get_userpass_input(s->cur_prompt, in, inlen);
4119 * Failed to get a password (for example
4120 * because one was supplied on the command line
4121 * which has already failed to work). Terminate.
4123 free_prompts(s->cur_prompt);
4124 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4129 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4131 * Defence against traffic analysis: we send a
4132 * whole bunch of packets containing strings of
4133 * different lengths. One of these strings is the
4134 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4135 * The others are all random data in
4136 * SSH1_MSG_IGNORE packets. This way a passive
4137 * listener can't tell which is the password, and
4138 * hence can't deduce the password length.
4140 * Anybody with a password length greater than 16
4141 * bytes is going to have enough entropy in their
4142 * password that a listener won't find it _that_
4143 * much help to know how long it is. So what we'll
4146 * - if password length < 16, we send 15 packets
4147 * containing string lengths 1 through 15
4149 * - otherwise, we let N be the nearest multiple
4150 * of 8 below the password length, and send 8
4151 * packets containing string lengths N through
4152 * N+7. This won't obscure the order of
4153 * magnitude of the password length, but it will
4154 * introduce a bit of extra uncertainty.
4156 * A few servers can't deal with SSH1_MSG_IGNORE, at
4157 * least in this context. For these servers, we need
4158 * an alternative defence. We make use of the fact
4159 * that the password is interpreted as a C string:
4160 * so we can append a NUL, then some random data.
4162 * A few servers can deal with neither SSH1_MSG_IGNORE
4163 * here _nor_ a padded password string.
4164 * For these servers we are left with no defences
4165 * against password length sniffing.
4167 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4168 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4170 * The server can deal with SSH1_MSG_IGNORE, so
4171 * we can use the primary defence.
4173 int bottom, top, pwlen, i;
4176 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4178 bottom = 0; /* zero length passwords are OK! :-) */
4181 bottom = pwlen & ~7;
4185 assert(pwlen >= bottom && pwlen <= top);
4187 randomstr = snewn(top + 1, char);
4189 for (i = bottom; i <= top; i++) {
4191 defer_packet(ssh, s->pwpkt_type,
4192 PKTT_PASSWORD, PKT_STR,
4193 s->cur_prompt->prompts[0]->result,
4194 PKTT_OTHER, PKT_END);
4196 for (j = 0; j < i; j++) {
4198 randomstr[j] = random_byte();
4199 } while (randomstr[j] == '\0');
4201 randomstr[i] = '\0';
4202 defer_packet(ssh, SSH1_MSG_IGNORE,
4203 PKT_STR, randomstr, PKT_END);
4206 logevent("Sending password with camouflage packets");
4207 ssh_pkt_defersend(ssh);
4210 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4212 * The server can't deal with SSH1_MSG_IGNORE
4213 * but can deal with padded passwords, so we
4214 * can use the secondary defence.
4220 len = strlen(s->cur_prompt->prompts[0]->result);
4221 if (len < sizeof(string)) {
4223 strcpy(string, s->cur_prompt->prompts[0]->result);
4224 len++; /* cover the zero byte */
4225 while (len < sizeof(string)) {
4226 string[len++] = (char) random_byte();
4229 ss = s->cur_prompt->prompts[0]->result;
4231 logevent("Sending length-padded password");
4232 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4233 PKT_INT, len, PKT_DATA, ss, len,
4234 PKTT_OTHER, PKT_END);
4237 * The server is believed unable to cope with
4238 * any of our password camouflage methods.
4241 len = strlen(s->cur_prompt->prompts[0]->result);
4242 logevent("Sending unpadded password");
4243 send_packet(ssh, s->pwpkt_type,
4244 PKTT_PASSWORD, PKT_INT, len,
4245 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4246 PKTT_OTHER, PKT_END);
4249 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4250 PKT_STR, s->cur_prompt->prompts[0]->result,
4251 PKTT_OTHER, PKT_END);
4253 logevent("Sent password");
4254 free_prompts(s->cur_prompt);
4256 if (pktin->type == SSH1_SMSG_FAILURE) {
4257 if (flags & FLAG_VERBOSE)
4258 c_write_str(ssh, "Access denied\r\n");
4259 logevent("Authentication refused");
4260 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4261 bombout(("Strange packet received, type %d", pktin->type));
4267 if (s->publickey_blob) {
4268 sfree(s->publickey_blob);
4269 sfree(s->publickey_comment);
4272 logevent("Authentication successful");
4277 static void ssh_channel_try_eof(struct ssh_channel *c)
4280 assert(c->pending_eof); /* precondition for calling us */
4282 return; /* can't close: not even opened yet */
4283 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4284 return; /* can't send EOF: pending outgoing data */
4286 c->pending_eof = FALSE; /* we're about to send it */
4287 if (ssh->version == 1) {
4288 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4290 c->closes |= CLOSES_SENT_EOF;
4292 struct Packet *pktout;
4293 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4294 ssh2_pkt_adduint32(pktout, c->remoteid);
4295 ssh2_pkt_send(ssh, pktout);
4296 c->closes |= CLOSES_SENT_EOF;
4297 ssh2_channel_check_close(c);
4301 void sshfwd_write_eof(struct ssh_channel *c)
4305 if (ssh->state == SSH_STATE_CLOSED)
4308 if (c->closes & CLOSES_SENT_EOF)
4311 c->pending_eof = TRUE;
4312 ssh_channel_try_eof(c);
4315 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4319 if (ssh->state == SSH_STATE_CLOSED)
4324 x11_close(c->u.x11.s);
4325 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4329 case CHAN_SOCKDATA_DORMANT:
4330 pfd_close(c->u.pfd.s);
4331 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4334 c->type = CHAN_ZOMBIE;
4335 c->pending_eof = FALSE; /* this will confuse a zombie channel */
4337 ssh2_channel_check_close(c);
4340 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4344 if (ssh->state == SSH_STATE_CLOSED)
4347 if (ssh->version == 1) {
4348 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4349 PKT_INT, c->remoteid,
4350 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
4351 PKTT_OTHER, PKT_END);
4353 * In SSH-1 we can return 0 here - implying that forwarded
4354 * connections are never individually throttled - because
4355 * the only circumstance that can cause throttling will be
4356 * the whole SSH connection backing up, in which case
4357 * _everything_ will be throttled as a whole.
4361 ssh2_add_channel_data(c, buf, len);
4362 return ssh2_try_send(c);
4366 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4371 if (ssh->state == SSH_STATE_CLOSED)
4374 if (ssh->version == 1) {
4375 buflimit = SSH1_BUFFER_LIMIT;
4377 buflimit = c->v.v2.locmaxwin;
4378 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4380 if (c->throttling_conn && bufsize <= buflimit) {
4381 c->throttling_conn = 0;
4382 ssh_throttle_conn(ssh, -1);
4386 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4388 struct queued_handler *qh = ssh->qhead;
4392 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4395 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4396 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4399 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4400 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4404 ssh->qhead = qh->next;
4406 if (ssh->qhead->msg1 > 0) {
4407 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4408 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4410 if (ssh->qhead->msg2 > 0) {
4411 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4412 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4415 ssh->qhead = ssh->qtail = NULL;
4418 qh->handler(ssh, pktin, qh->ctx);
4423 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4424 chandler_fn_t handler, void *ctx)
4426 struct queued_handler *qh;
4428 qh = snew(struct queued_handler);
4431 qh->handler = handler;
4435 if (ssh->qtail == NULL) {
4439 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4440 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4443 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4444 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4447 ssh->qtail->next = qh;
4452 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4454 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4456 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4457 SSH2_MSG_REQUEST_SUCCESS)) {
4458 logeventf(ssh, "Remote port forwarding from %s enabled",
4461 logeventf(ssh, "Remote port forwarding from %s refused",
4464 rpf = del234(ssh->rportfwds, pf);
4466 pf->pfrec->remote = NULL;
4471 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4473 struct ssh_portfwd *epf;
4477 if (!ssh->portfwds) {
4478 ssh->portfwds = newtree234(ssh_portcmp);
4481 * Go through the existing port forwardings and tag them
4482 * with status==DESTROY. Any that we want to keep will be
4483 * re-enabled (status==KEEP) as we go through the
4484 * configuration and find out which bits are the same as
4487 struct ssh_portfwd *epf;
4489 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4490 epf->status = DESTROY;
4493 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4495 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4496 char *kp, *kp2, *vp, *vp2;
4497 char address_family, type;
4498 int sport,dport,sserv,dserv;
4499 char *sports, *dports, *saddr, *host;
4503 address_family = 'A';
4505 if (*kp == 'A' || *kp == '4' || *kp == '6')
4506 address_family = *kp++;
4507 if (*kp == 'L' || *kp == 'R')
4510 if ((kp2 = strchr(kp, ':')) != NULL) {
4512 * There's a colon in the middle of the source port
4513 * string, which means that the part before it is
4514 * actually a source address.
4516 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4522 sport = atoi(sports);
4526 sport = net_service_lookup(sports);
4528 logeventf(ssh, "Service lookup failed for source"
4529 " port \"%s\"", sports);
4533 if (type == 'L' && !strcmp(val, "D")) {
4534 /* dynamic forwarding */
4541 /* ordinary forwarding */
4543 vp2 = vp + strcspn(vp, ":");
4544 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4548 dport = atoi(dports);
4552 dport = net_service_lookup(dports);
4554 logeventf(ssh, "Service lookup failed for destination"
4555 " port \"%s\"", dports);
4560 if (sport && dport) {
4561 /* Set up a description of the source port. */
4562 struct ssh_portfwd *pfrec, *epfrec;
4564 pfrec = snew(struct ssh_portfwd);
4566 pfrec->saddr = saddr;
4567 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4568 pfrec->sport = sport;
4569 pfrec->daddr = host;
4570 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4571 pfrec->dport = dport;
4572 pfrec->local = NULL;
4573 pfrec->remote = NULL;
4574 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4575 address_family == '6' ? ADDRTYPE_IPV6 :
4578 epfrec = add234(ssh->portfwds, pfrec);
4579 if (epfrec != pfrec) {
4580 if (epfrec->status == DESTROY) {
4582 * We already have a port forwarding up and running
4583 * with precisely these parameters. Hence, no need
4584 * to do anything; simply re-tag the existing one
4587 epfrec->status = KEEP;
4590 * Anything else indicates that there was a duplicate
4591 * in our input, which we'll silently ignore.
4593 free_portfwd(pfrec);
4595 pfrec->status = CREATE;
4604 * Now go through and destroy any port forwardings which were
4607 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4608 if (epf->status == DESTROY) {
4611 message = dupprintf("%s port forwarding from %s%s%d",
4612 epf->type == 'L' ? "local" :
4613 epf->type == 'R' ? "remote" : "dynamic",
4614 epf->saddr ? epf->saddr : "",
4615 epf->saddr ? ":" : "",
4618 if (epf->type != 'D') {
4619 char *msg2 = dupprintf("%s to %s:%d", message,
4620 epf->daddr, epf->dport);
4625 logeventf(ssh, "Cancelling %s", message);
4628 /* epf->remote or epf->local may be NULL if setting up a
4629 * forwarding failed. */
4631 struct ssh_rportfwd *rpf = epf->remote;
4632 struct Packet *pktout;
4635 * Cancel the port forwarding at the server
4638 if (ssh->version == 1) {
4640 * We cannot cancel listening ports on the
4641 * server side in SSH-1! There's no message
4642 * to support it. Instead, we simply remove
4643 * the rportfwd record from the local end
4644 * so that any connections the server tries
4645 * to make on it are rejected.
4648 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4649 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4650 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4652 ssh2_pkt_addstring(pktout, epf->saddr);
4653 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4654 /* XXX: rport_acceptall may not represent
4655 * what was used to open the original connection,
4656 * since it's reconfigurable. */
4657 ssh2_pkt_addstring(pktout, "");
4659 ssh2_pkt_addstring(pktout, "localhost");
4661 ssh2_pkt_adduint32(pktout, epf->sport);
4662 ssh2_pkt_send(ssh, pktout);
4665 del234(ssh->rportfwds, rpf);
4667 } else if (epf->local) {
4668 pfd_terminate(epf->local);
4671 delpos234(ssh->portfwds, i);
4673 i--; /* so we don't skip one in the list */
4677 * And finally, set up any new port forwardings (status==CREATE).
4679 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4680 if (epf->status == CREATE) {
4681 char *sportdesc, *dportdesc;
4682 sportdesc = dupprintf("%s%s%s%s%d%s",
4683 epf->saddr ? epf->saddr : "",
4684 epf->saddr ? ":" : "",
4685 epf->sserv ? epf->sserv : "",
4686 epf->sserv ? "(" : "",
4688 epf->sserv ? ")" : "");
4689 if (epf->type == 'D') {
4692 dportdesc = dupprintf("%s:%s%s%d%s",
4694 epf->dserv ? epf->dserv : "",
4695 epf->dserv ? "(" : "",
4697 epf->dserv ? ")" : "");
4700 if (epf->type == 'L') {
4701 const char *err = pfd_addforward(epf->daddr, epf->dport,
4702 epf->saddr, epf->sport,
4705 epf->addressfamily);
4707 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4708 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4709 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4710 sportdesc, dportdesc,
4711 err ? " failed: " : "", err ? err : "");
4712 } else if (epf->type == 'D') {
4713 const char *err = pfd_addforward(NULL, -1,
4714 epf->saddr, epf->sport,
4717 epf->addressfamily);
4719 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4720 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4721 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4723 err ? " failed: " : "", err ? err : "");
4725 struct ssh_rportfwd *pf;
4728 * Ensure the remote port forwardings tree exists.
4730 if (!ssh->rportfwds) {
4731 if (ssh->version == 1)
4732 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4734 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4737 pf = snew(struct ssh_rportfwd);
4738 pf->dhost = dupstr(epf->daddr);
4739 pf->dport = epf->dport;
4741 pf->shost = dupstr(epf->saddr);
4742 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4743 pf->shost = dupstr("");
4745 pf->shost = dupstr("localhost");
4747 pf->sport = epf->sport;
4748 if (add234(ssh->rportfwds, pf) != pf) {
4749 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4750 epf->daddr, epf->dport);
4753 logeventf(ssh, "Requesting remote port %s"
4754 " forward to %s", sportdesc, dportdesc);
4756 pf->sportdesc = sportdesc;
4761 if (ssh->version == 1) {
4762 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4763 PKT_INT, epf->sport,
4764 PKT_STR, epf->daddr,
4765 PKT_INT, epf->dport,
4767 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4769 ssh_rportfwd_succfail, pf);
4771 struct Packet *pktout;
4772 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4773 ssh2_pkt_addstring(pktout, "tcpip-forward");
4774 ssh2_pkt_addbool(pktout, 1);/* want reply */
4775 ssh2_pkt_addstring(pktout, pf->shost);
4776 ssh2_pkt_adduint32(pktout, pf->sport);
4777 ssh2_pkt_send(ssh, pktout);
4779 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4780 SSH2_MSG_REQUEST_FAILURE,
4781 ssh_rportfwd_succfail, pf);
4790 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4793 int stringlen, bufsize;
4795 ssh_pkt_getstring(pktin, &string, &stringlen);
4796 if (string == NULL) {
4797 bombout(("Incoming terminal data packet was badly formed"));
4801 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4803 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4804 ssh->v1_stdout_throttling = 1;
4805 ssh_throttle_conn(ssh, +1);
4809 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4811 /* Remote side is trying to open a channel to talk to our
4812 * X-Server. Give them back a local channel number. */
4813 struct ssh_channel *c;
4814 int remoteid = ssh_pkt_getuint32(pktin);
4816 logevent("Received X11 connect request");
4817 /* Refuse if X11 forwarding is disabled. */
4818 if (!ssh->X11_fwd_enabled) {
4819 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4820 PKT_INT, remoteid, PKT_END);
4821 logevent("Rejected X11 connect request");
4823 c = snew(struct ssh_channel);
4826 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4827 NULL, -1, ssh->conf) != NULL) {
4828 logevent("Opening X11 forward connection failed");
4830 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4831 PKT_INT, remoteid, PKT_END);
4834 ("Opening X11 forward connection succeeded");
4835 c->remoteid = remoteid;
4836 c->halfopen = FALSE;
4837 c->localid = alloc_channel_id(ssh);
4839 c->pending_eof = FALSE;
4840 c->throttling_conn = 0;
4841 c->type = CHAN_X11; /* identify channel type */
4842 add234(ssh->channels, c);
4843 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4844 PKT_INT, c->remoteid, PKT_INT,
4845 c->localid, PKT_END);
4846 logevent("Opened X11 forward channel");
4851 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4853 /* Remote side is trying to open a channel to talk to our
4854 * agent. Give them back a local channel number. */
4855 struct ssh_channel *c;
4856 int remoteid = ssh_pkt_getuint32(pktin);
4858 /* Refuse if agent forwarding is disabled. */
4859 if (!ssh->agentfwd_enabled) {
4860 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4861 PKT_INT, remoteid, PKT_END);
4863 c = snew(struct ssh_channel);
4865 c->remoteid = remoteid;
4866 c->halfopen = FALSE;
4867 c->localid = alloc_channel_id(ssh);
4869 c->pending_eof = FALSE;
4870 c->throttling_conn = 0;
4871 c->type = CHAN_AGENT; /* identify channel type */
4872 c->u.a.lensofar = 0;
4873 c->u.a.message = NULL;
4874 c->u.a.outstanding_requests = 0;
4875 add234(ssh->channels, c);
4876 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4877 PKT_INT, c->remoteid, PKT_INT, c->localid,
4882 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4884 /* Remote side is trying to open a channel to talk to a
4885 * forwarded port. Give them back a local channel number. */
4886 struct ssh_rportfwd pf, *pfp;
4892 remoteid = ssh_pkt_getuint32(pktin);
4893 ssh_pkt_getstring(pktin, &host, &hostsize);
4894 port = ssh_pkt_getuint32(pktin);
4896 pf.dhost = dupprintf(".*s", hostsize, host);
4898 pfp = find234(ssh->rportfwds, &pf, NULL);
4901 logeventf(ssh, "Rejected remote port open request for %s:%d",
4903 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4904 PKT_INT, remoteid, PKT_END);
4906 struct ssh_channel *c = snew(struct ssh_channel);
4909 logeventf(ssh, "Received remote port open request for %s:%d",
4911 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4912 c, ssh->conf, pfp->pfrec->addressfamily);
4914 logeventf(ssh, "Port open failed: %s", e);
4916 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4917 PKT_INT, remoteid, PKT_END);
4919 c->remoteid = remoteid;
4920 c->halfopen = FALSE;
4921 c->localid = alloc_channel_id(ssh);
4923 c->pending_eof = FALSE;
4924 c->throttling_conn = 0;
4925 c->type = CHAN_SOCKDATA; /* identify channel type */
4926 add234(ssh->channels, c);
4927 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4928 PKT_INT, c->remoteid, PKT_INT,
4929 c->localid, PKT_END);
4930 logevent("Forwarded port opened successfully");
4937 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4939 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4940 unsigned int localid = ssh_pkt_getuint32(pktin);
4941 struct ssh_channel *c;
4943 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4944 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4945 c->remoteid = localid;
4946 c->halfopen = FALSE;
4947 c->type = CHAN_SOCKDATA;
4948 c->throttling_conn = 0;
4949 pfd_confirm(c->u.pfd.s);
4952 if (c && c->pending_eof) {
4954 * We have a pending close on this channel,
4955 * which we decided on before the server acked
4956 * the channel open. So now we know the
4957 * remoteid, we can close it again.
4959 ssh_channel_try_eof(c);
4963 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4965 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4966 struct ssh_channel *c;
4968 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4969 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4970 logevent("Forwarded connection refused by server");
4971 pfd_close(c->u.pfd.s);
4972 del234(ssh->channels, c);
4977 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4979 /* Remote side closes a channel. */
4980 unsigned i = ssh_pkt_getuint32(pktin);
4981 struct ssh_channel *c;
4982 c = find234(ssh->channels, &i, ssh_channelfind);
4983 if (c && !c->halfopen) {
4985 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
4986 !(c->closes & CLOSES_RCVD_EOF)) {
4988 * Received CHANNEL_CLOSE, which we translate into
4991 int send_close = FALSE;
4993 c->closes |= CLOSES_RCVD_EOF;
4998 x11_send_eof(c->u.x11.s);
5004 pfd_send_eof(c->u.pfd.s);
5013 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5014 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5016 c->closes |= CLOSES_SENT_EOF;
5020 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5021 !(c->closes & CLOSES_RCVD_CLOSE)) {
5023 if (!(c->closes & CLOSES_SENT_EOF)) {
5024 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5025 " for which we never sent CHANNEL_CLOSE\n", i));
5028 c->closes |= CLOSES_RCVD_CLOSE;
5031 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5032 !(c->closes & CLOSES_SENT_CLOSE)) {
5033 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5034 PKT_INT, c->remoteid, PKT_END);
5035 c->closes |= CLOSES_SENT_CLOSE;
5038 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5039 ssh_channel_destroy(c);
5041 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5042 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5043 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5048 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5050 /* Data sent down one of our channels. */
5051 int i = ssh_pkt_getuint32(pktin);
5054 struct ssh_channel *c;
5056 ssh_pkt_getstring(pktin, &p, &len);
5058 c = find234(ssh->channels, &i, ssh_channelfind);
5063 bufsize = x11_send(c->u.x11.s, p, len);
5066 bufsize = pfd_send(c->u.pfd.s, p, len);
5069 /* Data for an agent message. Buffer it. */
5071 if (c->u.a.lensofar < 4) {
5072 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5073 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5077 c->u.a.lensofar += l;
5079 if (c->u.a.lensofar == 4) {
5081 4 + GET_32BIT(c->u.a.msglen);
5082 c->u.a.message = snewn(c->u.a.totallen,
5084 memcpy(c->u.a.message, c->u.a.msglen, 4);
5086 if (c->u.a.lensofar >= 4 && len > 0) {
5088 min(c->u.a.totallen - c->u.a.lensofar,
5090 memcpy(c->u.a.message + c->u.a.lensofar, p,
5094 c->u.a.lensofar += l;
5096 if (c->u.a.lensofar == c->u.a.totallen) {
5099 c->u.a.outstanding_requests++;
5100 if (agent_query(c->u.a.message,
5103 ssh_agentf_callback, c))
5104 ssh_agentf_callback(c, reply, replylen);
5105 sfree(c->u.a.message);
5106 c->u.a.lensofar = 0;
5109 bufsize = 0; /* agent channels never back up */
5112 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5113 c->throttling_conn = 1;
5114 ssh_throttle_conn(ssh, +1);
5119 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5121 ssh->exitcode = ssh_pkt_getuint32(pktin);
5122 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5123 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5125 * In case `helpful' firewalls or proxies tack
5126 * extra human-readable text on the end of the
5127 * session which we might mistake for another
5128 * encrypted packet, we close the session once
5129 * we've sent EXIT_CONFIRMATION.
5131 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5134 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5135 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5137 struct Packet *pktout = (struct Packet *)data;
5139 unsigned int arg = 0;
5140 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5141 if (i == lenof(ssh_ttymodes)) return;
5142 switch (ssh_ttymodes[i].type) {
5144 arg = ssh_tty_parse_specchar(val);
5147 arg = ssh_tty_parse_boolean(val);
5150 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5151 ssh2_pkt_addbyte(pktout, arg);
5155 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5156 struct Packet *pktin)
5158 crBegin(ssh->do_ssh1_connection_crstate);
5160 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5161 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5162 ssh1_smsg_stdout_stderr_data;
5164 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5165 ssh1_msg_channel_open_confirmation;
5166 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5167 ssh1_msg_channel_open_failure;
5168 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5169 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5170 ssh1_msg_channel_close;
5171 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5172 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5174 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
5175 logevent("Requesting agent forwarding");
5176 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5180 if (pktin->type != SSH1_SMSG_SUCCESS
5181 && pktin->type != SSH1_SMSG_FAILURE) {
5182 bombout(("Protocol confusion"));
5184 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5185 logevent("Agent forwarding refused");
5187 logevent("Agent forwarding enabled");
5188 ssh->agentfwd_enabled = TRUE;
5189 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5193 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5194 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5195 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
5196 logevent("Requesting X11 forwarding");
5198 * Note that while we blank the X authentication data here, we don't
5199 * take any special action to blank the start of an X11 channel,
5200 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5201 * without having session blanking enabled is likely to leak your
5202 * cookie into the log.
5204 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5205 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5206 PKT_STR, ssh->x11disp->remoteauthprotoname,
5208 PKT_STR, ssh->x11disp->remoteauthdatastring,
5210 PKT_INT, ssh->x11disp->screennum,
5213 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5214 PKT_STR, ssh->x11disp->remoteauthprotoname,
5216 PKT_STR, ssh->x11disp->remoteauthdatastring,
5223 if (pktin->type != SSH1_SMSG_SUCCESS
5224 && pktin->type != SSH1_SMSG_FAILURE) {
5225 bombout(("Protocol confusion"));
5227 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5228 logevent("X11 forwarding refused");
5230 logevent("X11 forwarding enabled");
5231 ssh->X11_fwd_enabled = TRUE;
5232 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5236 ssh_setup_portfwd(ssh, ssh->conf);
5237 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5239 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5241 /* Unpick the terminal-speed string. */
5242 /* XXX perhaps we should allow no speeds to be sent. */
5243 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5244 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5245 /* Send the pty request. */
5246 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5247 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5248 ssh_pkt_adduint32(pkt, ssh->term_height);
5249 ssh_pkt_adduint32(pkt, ssh->term_width);
5250 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5251 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5252 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5253 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5254 ssh_pkt_adduint32(pkt, ssh->ispeed);
5255 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5256 ssh_pkt_adduint32(pkt, ssh->ospeed);
5257 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5259 ssh->state = SSH_STATE_INTERMED;
5263 if (pktin->type != SSH1_SMSG_SUCCESS
5264 && pktin->type != SSH1_SMSG_FAILURE) {
5265 bombout(("Protocol confusion"));
5267 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5268 c_write_str(ssh, "Server refused to allocate pty\r\n");
5269 ssh->editing = ssh->echoing = 1;
5271 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5272 ssh->ospeed, ssh->ispeed);
5273 ssh->got_pty = TRUE;
5276 ssh->editing = ssh->echoing = 1;
5279 if (conf_get_int(ssh->conf, CONF_compression)) {
5280 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5284 if (pktin->type != SSH1_SMSG_SUCCESS
5285 && pktin->type != SSH1_SMSG_FAILURE) {
5286 bombout(("Protocol confusion"));
5288 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5289 c_write_str(ssh, "Server refused to compress\r\n");
5291 logevent("Started compression");
5292 ssh->v1_compressing = TRUE;
5293 ssh->cs_comp_ctx = zlib_compress_init();
5294 logevent("Initialised zlib (RFC1950) compression");
5295 ssh->sc_comp_ctx = zlib_decompress_init();
5296 logevent("Initialised zlib (RFC1950) decompression");
5300 * Start the shell or command.
5302 * Special case: if the first-choice command is an SSH-2
5303 * subsystem (hence not usable here) and the second choice
5304 * exists, we fall straight back to that.
5307 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5309 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5310 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5311 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5312 ssh->fallback_cmd = TRUE;
5315 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5317 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5318 logevent("Started session");
5321 ssh->state = SSH_STATE_SESSION;
5322 if (ssh->size_needed)
5323 ssh_size(ssh, ssh->term_width, ssh->term_height);
5324 if (ssh->eof_needed)
5325 ssh_special(ssh, TS_EOF);
5328 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5330 ssh->channels = newtree234(ssh_channelcmp);
5334 * By this point, most incoming packets are already being
5335 * handled by the dispatch table, and we need only pay
5336 * attention to the unusual ones.
5341 if (pktin->type == SSH1_SMSG_SUCCESS) {
5342 /* may be from EXEC_SHELL on some servers */
5343 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5344 /* may be from EXEC_SHELL on some servers
5345 * if no pty is available or in other odd cases. Ignore */
5347 bombout(("Strange packet received: type %d", pktin->type));
5352 int len = min(inlen, 512);
5353 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5354 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
5355 PKTT_OTHER, PKT_END);
5366 * Handle the top-level SSH-2 protocol.
5368 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5373 ssh_pkt_getstring(pktin, &msg, &msglen);
5374 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5377 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5379 /* log reason code in disconnect message */
5383 ssh_pkt_getstring(pktin, &msg, &msglen);
5384 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5387 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5389 /* Do nothing, because we're ignoring it! Duhh. */
5392 static void ssh1_protocol_setup(Ssh ssh)
5397 * Most messages are handled by the coroutines.
5399 for (i = 0; i < 256; i++)
5400 ssh->packet_dispatch[i] = NULL;
5403 * These special message types we install handlers for.
5405 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5406 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5407 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5410 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5411 struct Packet *pktin)
5413 unsigned char *in=(unsigned char*)vin;
5414 if (ssh->state == SSH_STATE_CLOSED)
5417 if (pktin && ssh->packet_dispatch[pktin->type]) {
5418 ssh->packet_dispatch[pktin->type](ssh, pktin);
5422 if (!ssh->protocol_initial_phase_done) {
5423 if (do_ssh1_login(ssh, in, inlen, pktin))
5424 ssh->protocol_initial_phase_done = TRUE;
5429 do_ssh1_connection(ssh, in, inlen, pktin);
5433 * Utility routine for decoding comma-separated strings in KEXINIT.
5435 static int in_commasep_string(char *needle, char *haystack, int haylen)
5438 if (!needle || !haystack) /* protect against null pointers */
5440 needlen = strlen(needle);
5443 * Is it at the start of the string?
5445 if (haylen >= needlen && /* haystack is long enough */
5446 !memcmp(needle, haystack, needlen) && /* initial match */
5447 (haylen == needlen || haystack[needlen] == ',')
5448 /* either , or EOS follows */
5452 * If not, search for the next comma and resume after that.
5453 * If no comma found, terminate.
5455 while (haylen > 0 && *haystack != ',')
5456 haylen--, haystack++;
5459 haylen--, haystack++; /* skip over comma itself */
5464 * Similar routine for checking whether we have the first string in a list.
5466 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5469 if (!needle || !haystack) /* protect against null pointers */
5471 needlen = strlen(needle);
5473 * Is it at the start of the string?
5475 if (haylen >= needlen && /* haystack is long enough */
5476 !memcmp(needle, haystack, needlen) && /* initial match */
5477 (haylen == needlen || haystack[needlen] == ',')
5478 /* either , or EOS follows */
5486 * SSH-2 key creation method.
5487 * (Currently assumes 2 lots of any hash are sufficient to generate
5488 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5490 #define SSH2_MKKEY_ITERS (2)
5491 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5492 unsigned char *keyspace)
5494 const struct ssh_hash *h = ssh->kex->hash;
5496 /* First hlen bytes. */
5498 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5499 hash_mpint(h, s, K);
5500 h->bytes(s, H, h->hlen);
5501 h->bytes(s, &chr, 1);
5502 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5503 h->final(s, keyspace);
5504 /* Next hlen bytes. */
5506 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5507 hash_mpint(h, s, K);
5508 h->bytes(s, H, h->hlen);
5509 h->bytes(s, keyspace, h->hlen);
5510 h->final(s, keyspace + h->hlen);
5514 * Handle the SSH-2 transport layer.
5516 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5517 struct Packet *pktin)
5519 unsigned char *in = (unsigned char *)vin;
5520 struct do_ssh2_transport_state {
5522 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5523 Bignum p, g, e, f, K;
5526 int kex_init_value, kex_reply_value;
5527 const struct ssh_mac **maclist;
5529 const struct ssh2_cipher *cscipher_tobe;
5530 const struct ssh2_cipher *sccipher_tobe;
5531 const struct ssh_mac *csmac_tobe;
5532 const struct ssh_mac *scmac_tobe;
5533 const struct ssh_compress *cscomp_tobe;
5534 const struct ssh_compress *sccomp_tobe;
5535 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5536 int hostkeylen, siglen, rsakeylen;
5537 void *hkey; /* actual host key */
5538 void *rsakey; /* for RSA kex */
5539 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5540 int n_preferred_kex;
5541 const struct ssh_kexes *preferred_kex[KEX_MAX];
5542 int n_preferred_ciphers;
5543 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5544 const struct ssh_compress *preferred_comp;
5545 int userauth_succeeded; /* for delayed compression */
5546 int pending_compression;
5547 int got_session_id, activated_authconn;
5548 struct Packet *pktout;
5553 crState(do_ssh2_transport_state);
5557 s->cscipher_tobe = s->sccipher_tobe = NULL;
5558 s->csmac_tobe = s->scmac_tobe = NULL;
5559 s->cscomp_tobe = s->sccomp_tobe = NULL;
5561 s->got_session_id = s->activated_authconn = FALSE;
5562 s->userauth_succeeded = FALSE;
5563 s->pending_compression = FALSE;
5566 * Be prepared to work around the buggy MAC problem.
5568 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5569 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5571 s->maclist = macs, s->nmacs = lenof(macs);
5574 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5576 int i, j, k, commalist_started;
5579 * Set up the preferred key exchange. (NULL => warn below here)
5581 s->n_preferred_kex = 0;
5582 for (i = 0; i < KEX_MAX; i++) {
5583 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5585 s->preferred_kex[s->n_preferred_kex++] =
5586 &ssh_diffiehellman_gex;
5589 s->preferred_kex[s->n_preferred_kex++] =
5590 &ssh_diffiehellman_group14;
5593 s->preferred_kex[s->n_preferred_kex++] =
5594 &ssh_diffiehellman_group1;
5597 s->preferred_kex[s->n_preferred_kex++] =
5601 /* Flag for later. Don't bother if it's the last in
5603 if (i < KEX_MAX - 1) {
5604 s->preferred_kex[s->n_preferred_kex++] = NULL;
5611 * Set up the preferred ciphers. (NULL => warn below here)
5613 s->n_preferred_ciphers = 0;
5614 for (i = 0; i < CIPHER_MAX; i++) {
5615 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
5616 case CIPHER_BLOWFISH:
5617 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5620 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
5621 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5625 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5628 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5630 case CIPHER_ARCFOUR:
5631 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5634 /* Flag for later. Don't bother if it's the last in
5636 if (i < CIPHER_MAX - 1) {
5637 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5644 * Set up preferred compression.
5646 if (conf_get_int(ssh->conf, CONF_compression))
5647 s->preferred_comp = &ssh_zlib;
5649 s->preferred_comp = &ssh_comp_none;
5652 * Enable queueing of outgoing auth- or connection-layer
5653 * packets while we are in the middle of a key exchange.
5655 ssh->queueing = TRUE;
5658 * Flag that KEX is in progress.
5660 ssh->kex_in_progress = TRUE;
5663 * Construct and send our key exchange packet.
5665 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5666 for (i = 0; i < 16; i++)
5667 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5668 /* List key exchange algorithms. */
5669 ssh2_pkt_addstring_start(s->pktout);
5670 commalist_started = 0;
5671 for (i = 0; i < s->n_preferred_kex; i++) {
5672 const struct ssh_kexes *k = s->preferred_kex[i];
5673 if (!k) continue; /* warning flag */
5674 for (j = 0; j < k->nkexes; j++) {
5675 if (commalist_started)
5676 ssh2_pkt_addstring_str(s->pktout, ",");
5677 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5678 commalist_started = 1;
5681 /* List server host key algorithms. */
5682 if (!s->got_session_id) {
5684 * In the first key exchange, we list all the algorithms
5685 * we're prepared to cope with.
5687 ssh2_pkt_addstring_start(s->pktout);
5688 for (i = 0; i < lenof(hostkey_algs); i++) {
5689 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5690 if (i < lenof(hostkey_algs) - 1)
5691 ssh2_pkt_addstring_str(s->pktout, ",");
5695 * In subsequent key exchanges, we list only the kex
5696 * algorithm that was selected in the first key exchange,
5697 * so that we keep getting the same host key and hence
5698 * don't have to interrupt the user's session to ask for
5702 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
5704 /* List encryption algorithms (client->server then server->client). */
5705 for (k = 0; k < 2; k++) {
5706 ssh2_pkt_addstring_start(s->pktout);
5707 commalist_started = 0;
5708 for (i = 0; i < s->n_preferred_ciphers; i++) {
5709 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5710 if (!c) continue; /* warning flag */
5711 for (j = 0; j < c->nciphers; j++) {
5712 if (commalist_started)
5713 ssh2_pkt_addstring_str(s->pktout, ",");
5714 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5715 commalist_started = 1;
5719 /* List MAC algorithms (client->server then server->client). */
5720 for (j = 0; j < 2; j++) {
5721 ssh2_pkt_addstring_start(s->pktout);
5722 for (i = 0; i < s->nmacs; i++) {
5723 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5724 if (i < s->nmacs - 1)
5725 ssh2_pkt_addstring_str(s->pktout, ",");
5728 /* List client->server compression algorithms,
5729 * then server->client compression algorithms. (We use the
5730 * same set twice.) */
5731 for (j = 0; j < 2; j++) {
5732 ssh2_pkt_addstring_start(s->pktout);
5733 assert(lenof(compressions) > 1);
5734 /* Prefer non-delayed versions */
5735 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5736 /* We don't even list delayed versions of algorithms until
5737 * they're allowed to be used, to avoid a race. See the end of
5739 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
5740 ssh2_pkt_addstring_str(s->pktout, ",");
5741 ssh2_pkt_addstring_str(s->pktout,
5742 s->preferred_comp->delayed_name);
5744 for (i = 0; i < lenof(compressions); i++) {
5745 const struct ssh_compress *c = compressions[i];
5746 if (c != s->preferred_comp) {
5747 ssh2_pkt_addstring_str(s->pktout, ",");
5748 ssh2_pkt_addstring_str(s->pktout, c->name);
5749 if (s->userauth_succeeded && c->delayed_name) {
5750 ssh2_pkt_addstring_str(s->pktout, ",");
5751 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5756 /* List client->server languages. Empty list. */
5757 ssh2_pkt_addstring_start(s->pktout);
5758 /* List server->client languages. Empty list. */
5759 ssh2_pkt_addstring_start(s->pktout);
5760 /* First KEX packet does _not_ follow, because we're not that brave. */
5761 ssh2_pkt_addbool(s->pktout, FALSE);
5763 ssh2_pkt_adduint32(s->pktout, 0);
5766 s->our_kexinitlen = s->pktout->length - 5;
5767 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5768 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5770 ssh2_pkt_send_noqueue(ssh, s->pktout);
5773 crWaitUntilV(pktin);
5776 * Now examine the other side's KEXINIT to see what we're up
5780 char *str, *preferred;
5783 if (pktin->type != SSH2_MSG_KEXINIT) {
5784 bombout(("expected key exchange packet from server"));
5788 ssh->hostkey = NULL;
5789 s->cscipher_tobe = NULL;
5790 s->sccipher_tobe = NULL;
5791 s->csmac_tobe = NULL;
5792 s->scmac_tobe = NULL;
5793 s->cscomp_tobe = NULL;
5794 s->sccomp_tobe = NULL;
5795 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5797 pktin->savedpos += 16; /* skip garbage cookie */
5798 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5801 for (i = 0; i < s->n_preferred_kex; i++) {
5802 const struct ssh_kexes *k = s->preferred_kex[i];
5806 for (j = 0; j < k->nkexes; j++) {
5807 if (!preferred) preferred = k->list[j]->name;
5808 if (in_commasep_string(k->list[j]->name, str, len)) {
5809 ssh->kex = k->list[j];
5818 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5819 str ? str : "(null)"));
5823 * Note that the server's guess is considered wrong if it doesn't match
5824 * the first algorithm in our list, even if it's still the algorithm
5827 s->guessok = first_in_commasep_string(preferred, str, len);
5828 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5829 for (i = 0; i < lenof(hostkey_algs); i++) {
5830 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5831 ssh->hostkey = hostkey_algs[i];
5835 if (!ssh->hostkey) {
5836 bombout(("Couldn't agree a host key algorithm (available: %s)",
5837 str ? str : "(null)"));
5841 s->guessok = s->guessok &&
5842 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5843 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5844 for (i = 0; i < s->n_preferred_ciphers; i++) {
5845 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5847 s->warn_cscipher = TRUE;
5849 for (j = 0; j < c->nciphers; j++) {
5850 if (in_commasep_string(c->list[j]->name, str, len)) {
5851 s->cscipher_tobe = c->list[j];
5856 if (s->cscipher_tobe)
5859 if (!s->cscipher_tobe) {
5860 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5861 str ? str : "(null)"));
5865 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5866 for (i = 0; i < s->n_preferred_ciphers; i++) {
5867 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5869 s->warn_sccipher = TRUE;
5871 for (j = 0; j < c->nciphers; j++) {
5872 if (in_commasep_string(c->list[j]->name, str, len)) {
5873 s->sccipher_tobe = c->list[j];
5878 if (s->sccipher_tobe)
5881 if (!s->sccipher_tobe) {
5882 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5883 str ? str : "(null)"));
5887 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5888 for (i = 0; i < s->nmacs; i++) {
5889 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5890 s->csmac_tobe = s->maclist[i];
5894 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5895 for (i = 0; i < s->nmacs; i++) {
5896 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5897 s->scmac_tobe = s->maclist[i];
5901 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5902 for (i = 0; i < lenof(compressions) + 1; i++) {
5903 const struct ssh_compress *c =
5904 i == 0 ? s->preferred_comp : compressions[i - 1];
5905 if (in_commasep_string(c->name, str, len)) {
5908 } else if (in_commasep_string(c->delayed_name, str, len)) {
5909 if (s->userauth_succeeded) {
5913 s->pending_compression = TRUE; /* try this later */
5917 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5918 for (i = 0; i < lenof(compressions) + 1; i++) {
5919 const struct ssh_compress *c =
5920 i == 0 ? s->preferred_comp : compressions[i - 1];
5921 if (in_commasep_string(c->name, str, len)) {
5924 } else if (in_commasep_string(c->delayed_name, str, len)) {
5925 if (s->userauth_succeeded) {
5929 s->pending_compression = TRUE; /* try this later */
5933 if (s->pending_compression) {
5934 logevent("Server supports delayed compression; "
5935 "will try this later");
5937 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5938 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5939 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5941 ssh->exhash = ssh->kex->hash->init();
5942 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5943 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5944 hash_string(ssh->kex->hash, ssh->exhash,
5945 s->our_kexinit, s->our_kexinitlen);
5946 sfree(s->our_kexinit);
5947 if (pktin->length > 5)
5948 hash_string(ssh->kex->hash, ssh->exhash,
5949 pktin->data + 5, pktin->length - 5);
5952 ssh_set_frozen(ssh, 1);
5953 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5955 ssh_dialog_callback, ssh);
5956 if (s->dlgret < 0) {
5960 bombout(("Unexpected data from server while"
5961 " waiting for user response"));
5964 } while (pktin || inlen > 0);
5965 s->dlgret = ssh->user_response;
5967 ssh_set_frozen(ssh, 0);
5968 if (s->dlgret == 0) {
5969 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5975 if (s->warn_cscipher) {
5976 ssh_set_frozen(ssh, 1);
5977 s->dlgret = askalg(ssh->frontend,
5978 "client-to-server cipher",
5979 s->cscipher_tobe->name,
5980 ssh_dialog_callback, ssh);
5981 if (s->dlgret < 0) {
5985 bombout(("Unexpected data from server while"
5986 " waiting for user response"));
5989 } while (pktin || inlen > 0);
5990 s->dlgret = ssh->user_response;
5992 ssh_set_frozen(ssh, 0);
5993 if (s->dlgret == 0) {
5994 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6000 if (s->warn_sccipher) {
6001 ssh_set_frozen(ssh, 1);
6002 s->dlgret = askalg(ssh->frontend,
6003 "server-to-client cipher",
6004 s->sccipher_tobe->name,
6005 ssh_dialog_callback, ssh);
6006 if (s->dlgret < 0) {
6010 bombout(("Unexpected data from server while"
6011 " waiting for user response"));
6014 } while (pktin || inlen > 0);
6015 s->dlgret = ssh->user_response;
6017 ssh_set_frozen(ssh, 0);
6018 if (s->dlgret == 0) {
6019 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6025 if (s->ignorepkt) /* first_kex_packet_follows */
6026 crWaitUntilV(pktin); /* Ignore packet */
6029 if (ssh->kex->main_type == KEXTYPE_DH) {
6031 * Work out the number of bits of key we will need from the
6032 * key exchange. We start with the maximum key length of
6038 csbits = s->cscipher_tobe->keylen;
6039 scbits = s->sccipher_tobe->keylen;
6040 s->nbits = (csbits > scbits ? csbits : scbits);
6042 /* The keys only have hlen-bit entropy, since they're based on
6043 * a hash. So cap the key size at hlen bits. */
6044 if (s->nbits > ssh->kex->hash->hlen * 8)
6045 s->nbits = ssh->kex->hash->hlen * 8;
6048 * If we're doing Diffie-Hellman group exchange, start by
6049 * requesting a group.
6051 if (!ssh->kex->pdata) {
6052 logevent("Doing Diffie-Hellman group exchange");
6053 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6055 * Work out how big a DH group we will need to allow that
6058 s->pbits = 512 << ((s->nbits - 1) / 64);
6059 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6060 ssh2_pkt_adduint32(s->pktout, s->pbits);
6061 ssh2_pkt_send_noqueue(ssh, s->pktout);
6063 crWaitUntilV(pktin);
6064 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6065 bombout(("expected key exchange group packet from server"));
6068 s->p = ssh2_pkt_getmp(pktin);
6069 s->g = ssh2_pkt_getmp(pktin);
6070 if (!s->p || !s->g) {
6071 bombout(("unable to read mp-ints from incoming group packet"));
6074 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6075 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6076 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6078 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6079 ssh->kex_ctx = dh_setup_group(ssh->kex);
6080 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6081 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6082 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6083 ssh->kex->groupname);
6086 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6087 ssh->kex->hash->text_name);
6089 * Now generate and send e for Diffie-Hellman.
6091 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6092 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6093 s->pktout = ssh2_pkt_init(s->kex_init_value);
6094 ssh2_pkt_addmp(s->pktout, s->e);
6095 ssh2_pkt_send_noqueue(ssh, s->pktout);
6097 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6098 crWaitUntilV(pktin);
6099 if (pktin->type != s->kex_reply_value) {
6100 bombout(("expected key exchange reply packet from server"));
6103 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6104 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6105 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6106 s->f = ssh2_pkt_getmp(pktin);
6108 bombout(("unable to parse key exchange reply packet"));
6111 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6113 s->K = dh_find_K(ssh->kex_ctx, s->f);
6115 /* We assume everything from now on will be quick, and it might
6116 * involve user interaction. */
6117 set_busy_status(ssh->frontend, BUSY_NOT);
6119 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6120 if (!ssh->kex->pdata) {
6121 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6122 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6123 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6125 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6126 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6128 dh_cleanup(ssh->kex_ctx);
6130 if (!ssh->kex->pdata) {
6135 logeventf(ssh, "Doing RSA key exchange with hash %s",
6136 ssh->kex->hash->text_name);
6137 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6139 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6142 crWaitUntilV(pktin);
6143 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6144 bombout(("expected RSA public key packet from server"));
6148 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6149 hash_string(ssh->kex->hash, ssh->exhash,
6150 s->hostkeydata, s->hostkeylen);
6151 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6155 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6156 s->rsakeydata = snewn(s->rsakeylen, char);
6157 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6160 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6162 sfree(s->rsakeydata);
6163 bombout(("unable to parse RSA public key from server"));
6167 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6170 * Next, set up a shared secret K, of precisely KLEN -
6171 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6172 * RSA key modulus and HLEN is the bit length of the hash
6176 int klen = ssh_rsakex_klen(s->rsakey);
6177 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6179 unsigned char *kstr1, *kstr2, *outstr;
6180 int kstr1len, kstr2len, outstrlen;
6182 s->K = bn_power_2(nbits - 1);
6184 for (i = 0; i < nbits; i++) {
6186 byte = random_byte();
6188 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6192 * Encode this as an mpint.
6194 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6195 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6196 PUT_32BIT(kstr2, kstr1len);
6197 memcpy(kstr2 + 4, kstr1, kstr1len);
6200 * Encrypt it with the given RSA key.
6202 outstrlen = (klen + 7) / 8;
6203 outstr = snewn(outstrlen, unsigned char);
6204 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6205 outstr, outstrlen, s->rsakey);
6208 * And send it off in a return packet.
6210 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6211 ssh2_pkt_addstring_start(s->pktout);
6212 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6213 ssh2_pkt_send_noqueue(ssh, s->pktout);
6215 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6222 ssh_rsakex_freekey(s->rsakey);
6224 crWaitUntilV(pktin);
6225 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6226 sfree(s->rsakeydata);
6227 bombout(("expected signature packet from server"));
6231 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6233 sfree(s->rsakeydata);
6236 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6237 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6238 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6240 ssh->kex_ctx = NULL;
6243 debug(("Exchange hash is:\n"));
6244 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6248 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6249 (char *)s->exchange_hash,
6250 ssh->kex->hash->hlen)) {
6251 bombout(("Server's host key did not match the signature supplied"));
6255 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6256 if (!s->got_session_id) {
6258 * Authenticate remote host: verify host key. (We've already
6259 * checked the signature of the exchange hash.)
6261 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6262 ssh_set_frozen(ssh, 1);
6263 s->dlgret = verify_ssh_host_key(ssh->frontend,
6264 ssh->savedhost, ssh->savedport,
6265 ssh->hostkey->keytype, s->keystr,
6267 ssh_dialog_callback, ssh);
6268 if (s->dlgret < 0) {
6272 bombout(("Unexpected data from server while waiting"
6273 " for user host key response"));
6276 } while (pktin || inlen > 0);
6277 s->dlgret = ssh->user_response;
6279 ssh_set_frozen(ssh, 0);
6280 if (s->dlgret == 0) {
6281 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6285 logevent("Host key fingerprint is:");
6286 logevent(s->fingerprint);
6287 sfree(s->fingerprint);
6289 * Save this host key, to check against the one presented in
6290 * subsequent rekeys.
6292 ssh->hostkey_str = s->keystr;
6295 * In a rekey, we never present an interactive host key
6296 * verification request to the user. Instead, we simply
6297 * enforce that the key we're seeing this time is identical to
6298 * the one we saw before.
6300 if (strcmp(ssh->hostkey_str, s->keystr)) {
6301 bombout(("Host key was different in repeat key exchange"));
6306 ssh->hostkey->freekey(s->hkey);
6309 * The exchange hash from the very first key exchange is also
6310 * the session id, used in session key construction and
6313 if (!s->got_session_id) {
6314 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6315 memcpy(ssh->v2_session_id, s->exchange_hash,
6316 sizeof(s->exchange_hash));
6317 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6318 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6319 s->got_session_id = TRUE;
6323 * Send SSH2_MSG_NEWKEYS.
6325 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6326 ssh2_pkt_send_noqueue(ssh, s->pktout);
6327 ssh->outgoing_data_size = 0; /* start counting from here */
6330 * We've sent client NEWKEYS, so create and initialise
6331 * client-to-server session keys.
6333 if (ssh->cs_cipher_ctx)
6334 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6335 ssh->cscipher = s->cscipher_tobe;
6336 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6338 if (ssh->cs_mac_ctx)
6339 ssh->csmac->free_context(ssh->cs_mac_ctx);
6340 ssh->csmac = s->csmac_tobe;
6341 ssh->cs_mac_ctx = ssh->csmac->make_context();
6343 if (ssh->cs_comp_ctx)
6344 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6345 ssh->cscomp = s->cscomp_tobe;
6346 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6349 * Set IVs on client-to-server keys. Here we use the exchange
6350 * hash from the _first_ key exchange.
6353 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6354 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6355 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6356 assert((ssh->cscipher->keylen+7) / 8 <=
6357 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6358 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6359 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6360 assert(ssh->cscipher->blksize <=
6361 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6362 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6363 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6364 assert(ssh->csmac->len <=
6365 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6366 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6367 smemclr(keyspace, sizeof(keyspace));
6370 logeventf(ssh, "Initialised %.200s client->server encryption",
6371 ssh->cscipher->text_name);
6372 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6373 ssh->csmac->text_name);
6374 if (ssh->cscomp->text_name)
6375 logeventf(ssh, "Initialised %s compression",
6376 ssh->cscomp->text_name);
6379 * Now our end of the key exchange is complete, we can send all
6380 * our queued higher-layer packets.
6382 ssh->queueing = FALSE;
6383 ssh2_pkt_queuesend(ssh);
6386 * Expect SSH2_MSG_NEWKEYS from server.
6388 crWaitUntilV(pktin);
6389 if (pktin->type != SSH2_MSG_NEWKEYS) {
6390 bombout(("expected new-keys packet from server"));
6393 ssh->incoming_data_size = 0; /* start counting from here */
6396 * We've seen server NEWKEYS, so create and initialise
6397 * server-to-client session keys.
6399 if (ssh->sc_cipher_ctx)
6400 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6401 ssh->sccipher = s->sccipher_tobe;
6402 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6404 if (ssh->sc_mac_ctx)
6405 ssh->scmac->free_context(ssh->sc_mac_ctx);
6406 ssh->scmac = s->scmac_tobe;
6407 ssh->sc_mac_ctx = ssh->scmac->make_context();
6409 if (ssh->sc_comp_ctx)
6410 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6411 ssh->sccomp = s->sccomp_tobe;
6412 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6415 * Set IVs on server-to-client keys. Here we use the exchange
6416 * hash from the _first_ key exchange.
6419 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6420 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6421 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6422 assert((ssh->sccipher->keylen+7) / 8 <=
6423 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6424 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6425 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6426 assert(ssh->sccipher->blksize <=
6427 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6428 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6429 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6430 assert(ssh->scmac->len <=
6431 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6432 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6433 smemclr(keyspace, sizeof(keyspace));
6435 logeventf(ssh, "Initialised %.200s server->client encryption",
6436 ssh->sccipher->text_name);
6437 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6438 ssh->scmac->text_name);
6439 if (ssh->sccomp->text_name)
6440 logeventf(ssh, "Initialised %s decompression",
6441 ssh->sccomp->text_name);
6444 * Free shared secret.
6449 * Key exchange is over. Loop straight back round if we have a
6450 * deferred rekey reason.
6452 if (ssh->deferred_rekey_reason) {
6453 logevent(ssh->deferred_rekey_reason);
6455 ssh->deferred_rekey_reason = NULL;
6456 goto begin_key_exchange;
6460 * Otherwise, schedule a timer for our next rekey.
6462 ssh->kex_in_progress = FALSE;
6463 ssh->last_rekey = GETTICKCOUNT();
6464 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6465 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6469 * Now we're encrypting. Begin returning 1 to the protocol main
6470 * function so that other things can run on top of the
6471 * transport. If we ever see a KEXINIT, we must go back to the
6474 * We _also_ go back to the start if we see pktin==NULL and
6475 * inlen negative, because this is a special signal meaning
6476 * `initiate client-driven rekey', and `in' contains a message
6477 * giving the reason for the rekey.
6479 * inlen==-1 means always initiate a rekey;
6480 * inlen==-2 means that userauth has completed successfully and
6481 * we should consider rekeying (for delayed compression).
6483 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6484 (!pktin && inlen < 0))) {
6486 if (!ssh->protocol_initial_phase_done) {
6487 ssh->protocol_initial_phase_done = TRUE;
6489 * Allow authconn to initialise itself.
6491 do_ssh2_authconn(ssh, NULL, 0, NULL);
6496 logevent("Server initiated key re-exchange");
6500 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6501 * delayed compression, if it's available.
6503 * draft-miller-secsh-compression-delayed-00 says that you
6504 * negotiate delayed compression in the first key exchange, and
6505 * both sides start compressing when the server has sent
6506 * USERAUTH_SUCCESS. This has a race condition -- the server
6507 * can't know when the client has seen it, and thus which incoming
6508 * packets it should treat as compressed.
6510 * Instead, we do the initial key exchange without offering the
6511 * delayed methods, but note if the server offers them; when we
6512 * get here, if a delayed method was available that was higher
6513 * on our list than what we got, we initiate a rekey in which we
6514 * _do_ list the delayed methods (and hopefully get it as a
6515 * result). Subsequent rekeys will do the same.
6517 assert(!s->userauth_succeeded); /* should only happen once */
6518 s->userauth_succeeded = TRUE;
6519 if (!s->pending_compression)
6520 /* Can't see any point rekeying. */
6521 goto wait_for_rekey; /* this is utterly horrid */
6522 /* else fall through to rekey... */
6523 s->pending_compression = FALSE;
6526 * Now we've decided to rekey.
6528 * Special case: if the server bug is set that doesn't
6529 * allow rekeying, we give a different log message and
6530 * continue waiting. (If such a server _initiates_ a rekey,
6531 * we process it anyway!)
6533 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6534 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6536 /* Reset the counters, so that at least this message doesn't
6537 * hit the event log _too_ often. */
6538 ssh->outgoing_data_size = 0;
6539 ssh->incoming_data_size = 0;
6540 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6542 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6545 goto wait_for_rekey; /* this is still utterly horrid */
6547 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6550 goto begin_key_exchange;
6556 * Add data to an SSH-2 channel output buffer.
6558 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6561 bufchain_add(&c->v.v2.outbuffer, buf, len);
6565 * Attempt to send data on an SSH-2 channel.
6567 static int ssh2_try_send(struct ssh_channel *c)
6570 struct Packet *pktout;
6573 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6576 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6577 if ((unsigned)len > c->v.v2.remwindow)
6578 len = c->v.v2.remwindow;
6579 if ((unsigned)len > c->v.v2.remmaxpkt)
6580 len = c->v.v2.remmaxpkt;
6581 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6582 ssh2_pkt_adduint32(pktout, c->remoteid);
6583 ssh2_pkt_addstring_start(pktout);
6584 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6585 ssh2_pkt_addstring_data(pktout, data, len);
6586 end_log_omission(ssh, pktout);
6587 ssh2_pkt_send(ssh, pktout);
6588 bufchain_consume(&c->v.v2.outbuffer, len);
6589 c->v.v2.remwindow -= len;
6593 * After having sent as much data as we can, return the amount
6596 ret = bufchain_size(&c->v.v2.outbuffer);
6599 * And if there's no data pending but we need to send an EOF, send
6602 if (!ret && c->pending_eof)
6603 ssh_channel_try_eof(c);
6608 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6611 if (c->closes & CLOSES_SENT_EOF)
6612 return; /* don't send on channels we've EOFed */
6613 bufsize = ssh2_try_send(c);
6616 case CHAN_MAINSESSION:
6617 /* stdin need not receive an unthrottle
6618 * notification since it will be polled */
6621 x11_unthrottle(c->u.x11.s);
6624 /* agent sockets are request/response and need no
6625 * buffer management */
6628 pfd_unthrottle(c->u.pfd.s);
6635 * Set up most of a new ssh_channel for SSH-2.
6637 static void ssh2_channel_init(struct ssh_channel *c)
6640 c->localid = alloc_channel_id(ssh);
6642 c->pending_eof = FALSE;
6643 c->throttling_conn = FALSE;
6644 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6645 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6646 c->v.v2.chanreq_head = NULL;
6647 c->v.v2.throttle_state = UNTHROTTLED;
6648 bufchain_init(&c->v.v2.outbuffer);
6652 * Construct the common parts of a CHANNEL_OPEN.
6654 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
6656 struct Packet *pktout;
6658 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6659 ssh2_pkt_addstring(pktout, type);
6660 ssh2_pkt_adduint32(pktout, c->localid);
6661 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
6662 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6667 * CHANNEL_FAILURE doesn't come with any indication of what message
6668 * caused it, so we have to keep track of the outstanding
6669 * CHANNEL_REQUESTs ourselves.
6671 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
6672 cchandler_fn_t handler, void *ctx)
6674 struct outstanding_channel_request *ocr =
6675 snew(struct outstanding_channel_request);
6677 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6678 ocr->handler = handler;
6681 if (!c->v.v2.chanreq_head)
6682 c->v.v2.chanreq_head = ocr;
6684 c->v.v2.chanreq_tail->next = ocr;
6685 c->v.v2.chanreq_tail = ocr;
6689 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6690 * NULL then a reply will be requested and the handler will be called
6691 * when it arrives. The returned packet is ready to have any
6692 * request-specific data added and be sent. Note that if a handler is
6693 * provided, it's essential that the request actually be sent.
6695 * The handler will usually be passed the response packet in pktin.
6696 * If pktin is NULL, this means that no reply will ever be forthcoming
6697 * (e.g. because the entire connection is being destroyed) and the
6698 * handler should free any storage it's holding.
6700 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
6701 cchandler_fn_t handler, void *ctx)
6703 struct Packet *pktout;
6705 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6706 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6707 ssh2_pkt_adduint32(pktout, c->remoteid);
6708 ssh2_pkt_addstring(pktout, type);
6709 ssh2_pkt_addbool(pktout, handler != NULL);
6710 if (handler != NULL)
6711 ssh2_queue_chanreq_handler(c, handler, ctx);
6716 * Potentially enlarge the window on an SSH-2 channel.
6718 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
6720 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6725 * Never send WINDOW_ADJUST for a channel that the remote side has
6726 * already sent EOF on; there's no point, since it won't be
6727 * sending any more data anyway. Ditto if _we've_ already sent
6730 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6734 * If the remote end has a habit of ignoring maxpkt, limit the
6735 * window so that it has no choice (assuming it doesn't ignore the
6738 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6739 newwin = OUR_V2_MAXPKT;
6742 * Only send a WINDOW_ADJUST if there's significantly more window
6743 * available than the other end thinks there is. This saves us
6744 * sending a WINDOW_ADJUST for every character in a shell session.
6746 * "Significant" is arbitrarily defined as half the window size.
6748 if (newwin / 2 >= c->v.v2.locwindow) {
6749 struct Packet *pktout;
6753 * In order to keep track of how much window the client
6754 * actually has available, we'd like it to acknowledge each
6755 * WINDOW_ADJUST. We can't do that directly, so we accompany
6756 * it with a CHANNEL_REQUEST that has to be acknowledged.
6758 * This is only necessary if we're opening the window wide.
6759 * If we're not, then throughput is being constrained by
6760 * something other than the maximum window size anyway.
6762 if (newwin == c->v.v2.locmaxwin &&
6763 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
6764 up = snew(unsigned);
6765 *up = newwin - c->v.v2.locwindow;
6766 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
6767 ssh2_handle_winadj_response, up);
6768 ssh2_pkt_send(ssh, pktout);
6770 if (c->v.v2.throttle_state != UNTHROTTLED)
6771 c->v.v2.throttle_state = UNTHROTTLING;
6773 /* Pretend the WINDOW_ADJUST was acked immediately. */
6774 c->v.v2.remlocwin = newwin;
6775 c->v.v2.throttle_state = THROTTLED;
6777 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6778 ssh2_pkt_adduint32(pktout, c->remoteid);
6779 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6780 ssh2_pkt_send(ssh, pktout);
6781 c->v.v2.locwindow = newwin;
6786 * Find the channel associated with a message. If there's no channel,
6787 * or it's not properly open, make a noise about it and return NULL.
6789 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6791 unsigned localid = ssh_pkt_getuint32(pktin);
6792 struct ssh_channel *c;
6794 c = find234(ssh->channels, &localid, ssh_channelfind);
6796 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6797 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6798 char *buf = dupprintf("Received %s for %s channel %u",
6799 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6801 c ? "half-open" : "nonexistent", localid);
6802 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6809 static void ssh2_handle_winadj_response(struct ssh_channel *c,
6810 struct Packet *pktin, void *ctx)
6812 unsigned *sizep = ctx;
6815 * Winadj responses should always be failures. However, at least
6816 * one server ("boks_sshd") is known to return SUCCESS for channel
6817 * requests it's never heard of, such as "winadj@putty". Raised
6818 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6819 * life, we don't worry about what kind of response we got.
6822 c->v.v2.remlocwin += *sizep;
6825 * winadj messages are only sent when the window is fully open, so
6826 * if we get an ack of one, we know any pending unthrottle is
6829 if (c->v.v2.throttle_state == UNTHROTTLING)
6830 c->v.v2.throttle_state = UNTHROTTLED;
6833 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
6835 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
6836 struct outstanding_channel_request *ocr;
6839 ocr = c->v.v2.chanreq_head;
6841 ssh2_msg_unexpected(ssh, pktin);
6844 ocr->handler(c, pktin, ocr->ctx);
6845 c->v.v2.chanreq_head = ocr->next;
6848 * We may now initiate channel-closing procedures, if that
6849 * CHANNEL_REQUEST was the last thing outstanding before we send
6852 ssh2_channel_check_close(c);
6855 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6857 struct ssh_channel *c;
6858 c = ssh2_channel_msg(ssh, pktin);
6861 if (!(c->closes & CLOSES_SENT_EOF)) {
6862 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6863 ssh2_try_send_and_unthrottle(ssh, c);
6867 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6871 struct ssh_channel *c;
6872 c = ssh2_channel_msg(ssh, pktin);
6875 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6876 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6877 return; /* extended but not stderr */
6878 ssh_pkt_getstring(pktin, &data, &length);
6881 c->v.v2.locwindow -= length;
6882 c->v.v2.remlocwin -= length;
6884 case CHAN_MAINSESSION:
6886 from_backend(ssh->frontend, pktin->type ==
6887 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6891 bufsize = x11_send(c->u.x11.s, data, length);
6894 bufsize = pfd_send(c->u.pfd.s, data, length);
6897 while (length > 0) {
6898 if (c->u.a.lensofar < 4) {
6899 unsigned int l = min(4 - c->u.a.lensofar,
6901 memcpy(c->u.a.msglen + c->u.a.lensofar,
6905 c->u.a.lensofar += l;
6907 if (c->u.a.lensofar == 4) {
6909 4 + GET_32BIT(c->u.a.msglen);
6910 c->u.a.message = snewn(c->u.a.totallen,
6912 memcpy(c->u.a.message, c->u.a.msglen, 4);
6914 if (c->u.a.lensofar >= 4 && length > 0) {
6916 min(c->u.a.totallen - c->u.a.lensofar,
6918 memcpy(c->u.a.message + c->u.a.lensofar,
6922 c->u.a.lensofar += l;
6924 if (c->u.a.lensofar == c->u.a.totallen) {
6927 c->u.a.outstanding_requests++;
6928 if (agent_query(c->u.a.message,
6931 ssh_agentf_callback, c))
6932 ssh_agentf_callback(c, reply, replylen);
6933 sfree(c->u.a.message);
6934 c->u.a.message = NULL;
6935 c->u.a.lensofar = 0;
6942 * If it looks like the remote end hit the end of its window,
6943 * and we didn't want it to do that, think about using a
6946 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6947 c->v.v2.locmaxwin < 0x40000000)
6948 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6950 * If we are not buffering too much data,
6951 * enlarge the window again at the remote side.
6952 * If we are buffering too much, we may still
6953 * need to adjust the window if the server's
6956 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6957 c->v.v2.locmaxwin - bufsize : 0);
6959 * If we're either buffering way too much data, or if we're
6960 * buffering anything at all and we're in "simple" mode,
6961 * throttle the whole channel.
6963 if ((bufsize > c->v.v2.locmaxwin ||
6964 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
6965 !c->throttling_conn) {
6966 c->throttling_conn = 1;
6967 ssh_throttle_conn(ssh, +1);
6972 static void ssh_channel_destroy(struct ssh_channel *c)
6977 case CHAN_MAINSESSION:
6978 ssh->mainchan = NULL;
6979 update_specials_menu(ssh->frontend);
6982 if (c->u.x11.s != NULL)
6983 x11_close(c->u.x11.s);
6984 logevent("Forwarded X11 connection terminated");
6987 sfree(c->u.a.message);
6990 if (c->u.pfd.s != NULL)
6991 pfd_close(c->u.pfd.s);
6992 logevent("Forwarded port closed");
6996 del234(ssh->channels, c);
6997 if (ssh->version == 2) {
6998 bufchain_clear(&c->v.v2.outbuffer);
6999 assert(c->v.v2.chanreq_head == NULL);
7004 * See if that was the last channel left open.
7005 * (This is only our termination condition if we're
7006 * not running in -N mode.)
7008 if (ssh->version == 2 &&
7009 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7010 count234(ssh->channels) == 0) {
7012 * We used to send SSH_MSG_DISCONNECT here,
7013 * because I'd believed that _every_ conforming
7014 * SSH-2 connection had to end with a disconnect
7015 * being sent by at least one side; apparently
7016 * I was wrong and it's perfectly OK to
7017 * unceremoniously slam the connection shut
7018 * when you're done, and indeed OpenSSH feels
7019 * this is more polite than sending a
7020 * DISCONNECT. So now we don't.
7022 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7026 static void ssh2_channel_check_close(struct ssh_channel *c)
7029 struct Packet *pktout;
7033 * If we've sent out our own CHANNEL_OPEN but not yet seen
7034 * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
7035 * it's too early to be sending close messages of any kind.
7040 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7041 c->type == CHAN_ZOMBIE) &&
7042 !c->v.v2.chanreq_head &&
7043 !(c->closes & CLOSES_SENT_CLOSE)) {
7045 * We have both sent and received EOF (or the channel is a
7046 * zombie), and we have no outstanding channel requests, which
7047 * means the channel is in final wind-up. But we haven't sent
7048 * CLOSE, so let's do so now.
7050 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7051 ssh2_pkt_adduint32(pktout, c->remoteid);
7052 ssh2_pkt_send(ssh, pktout);
7053 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7056 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7057 assert(c->v.v2.chanreq_head == NULL);
7059 * We have both sent and received CLOSE, which means we're
7060 * completely done with the channel.
7062 ssh_channel_destroy(c);
7066 static void ssh2_channel_got_eof(struct ssh_channel *c)
7068 if (c->closes & CLOSES_RCVD_EOF)
7069 return; /* already seen EOF */
7070 c->closes |= CLOSES_RCVD_EOF;
7072 if (c->type == CHAN_X11) {
7073 x11_send_eof(c->u.x11.s);
7074 } else if (c->type == CHAN_AGENT) {
7075 if (c->u.a.outstanding_requests == 0) {
7076 /* Manufacture an outgoing EOF in response to the incoming one. */
7077 sshfwd_write_eof(c);
7079 } else if (c->type == CHAN_SOCKDATA) {
7080 pfd_send_eof(c->u.pfd.s);
7081 } else if (c->type == CHAN_MAINSESSION) {
7084 if (!ssh->sent_console_eof &&
7085 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7087 * Either from_backend_eof told us that the front end
7088 * wants us to close the outgoing side of the connection
7089 * as soon as we see EOF from the far end, or else we've
7090 * unilaterally decided to do that because we've allocated
7091 * a remote pty and hence EOF isn't a particularly
7092 * meaningful concept.
7094 sshfwd_write_eof(c);
7096 ssh->sent_console_eof = TRUE;
7099 ssh2_channel_check_close(c);
7102 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7104 struct ssh_channel *c;
7106 c = ssh2_channel_msg(ssh, pktin);
7109 ssh2_channel_got_eof(c);
7112 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7114 struct ssh_channel *c;
7116 c = ssh2_channel_msg(ssh, pktin);
7121 * When we receive CLOSE on a channel, we assume it comes with an
7122 * implied EOF if we haven't seen EOF yet.
7124 ssh2_channel_got_eof(c);
7127 * And we also send an outgoing EOF, if we haven't already, on the
7128 * assumption that CLOSE is a pretty forceful announcement that
7129 * the remote side is doing away with the entire channel. (If it
7130 * had wanted to send us EOF and continue receiving data from us,
7131 * it would have just sent CHANNEL_EOF.)
7133 if (!(c->closes & CLOSES_SENT_EOF)) {
7135 * Make sure we don't read any more from whatever our local
7136 * data source is for this channel.
7139 case CHAN_MAINSESSION:
7140 ssh->send_ok = 0; /* stop trying to read from stdin */
7143 x11_override_throttle(c->u.x11.s, 1);
7146 pfd_override_throttle(c->u.pfd.s, 1);
7151 * Abandon any buffered data we still wanted to send to this
7152 * channel. Receiving a CHANNEL_CLOSE is an indication that
7153 * the server really wants to get on and _destroy_ this
7154 * channel, and it isn't going to send us any further
7155 * WINDOW_ADJUSTs to permit us to send pending stuff.
7157 bufchain_clear(&c->v.v2.outbuffer);
7160 * Send outgoing EOF.
7162 sshfwd_write_eof(c);
7166 * Now process the actual close.
7168 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7169 c->closes |= CLOSES_RCVD_CLOSE;
7170 ssh2_channel_check_close(c);
7174 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7176 struct ssh_channel *c;
7178 c = ssh2_channel_msg(ssh, pktin);
7181 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7182 c->remoteid = ssh_pkt_getuint32(pktin);
7183 c->halfopen = FALSE;
7184 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7185 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7187 if (c->type == CHAN_SOCKDATA_DORMANT) {
7188 c->type = CHAN_SOCKDATA;
7190 pfd_confirm(c->u.pfd.s);
7191 } else if (c->type == CHAN_ZOMBIE) {
7193 * This case can occur if a local socket error occurred
7194 * between us sending out CHANNEL_OPEN and receiving
7195 * OPEN_CONFIRMATION. In this case, all we can do is
7196 * immediately initiate close proceedings now that we know the
7197 * server's id to put in the close message.
7199 ssh2_channel_check_close(c);
7202 * We never expect to receive OPEN_CONFIRMATION for any
7203 * *other* channel type (since only local-to-remote port
7204 * forwardings cause us to send CHANNEL_OPEN after the main
7205 * channel is live - all other auxiliary channel types are
7206 * initiated from the server end). It's safe to enforce this
7207 * by assertion rather than by ssh_disconnect, because the
7208 * real point is that we never constructed a half-open channel
7209 * structure in the first place with any type other than the
7212 assert(!"Funny channel type in ssh2_msg_channel_open_confirmation");
7216 ssh_channel_try_eof(c); /* in case we had a pending EOF */
7219 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7221 static const char *const reasons[] = {
7222 "<unknown reason code>",
7223 "Administratively prohibited",
7225 "Unknown channel type",
7226 "Resource shortage",
7228 unsigned reason_code;
7229 char *reason_string;
7231 struct ssh_channel *c;
7233 c = ssh2_channel_msg(ssh, pktin);
7236 assert(c->halfopen); /* ssh2_channel_msg will have enforced this */
7238 if (c->type == CHAN_SOCKDATA_DORMANT) {
7239 reason_code = ssh_pkt_getuint32(pktin);
7240 if (reason_code >= lenof(reasons))
7241 reason_code = 0; /* ensure reasons[reason_code] in range */
7242 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7243 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7244 reasons[reason_code], reason_length, reason_string);
7246 pfd_close(c->u.pfd.s);
7247 } else if (c->type == CHAN_ZOMBIE) {
7249 * This case can occur if a local socket error occurred
7250 * between us sending out CHANNEL_OPEN and receiving
7251 * OPEN_FAILURE. In this case, we need do nothing except allow
7252 * the code below to throw the half-open channel away.
7256 * We never expect to receive OPEN_FAILURE for any *other*
7257 * channel type (since only local-to-remote port forwardings
7258 * cause us to send CHANNEL_OPEN after the main channel is
7259 * live - all other auxiliary channel types are initiated from
7260 * the server end). It's safe to enforce this by assertion
7261 * rather than by ssh_disconnect, because the real point is
7262 * that we never constructed a half-open channel structure in
7263 * the first place with any type other than the above.
7265 assert(!"Funny channel type in ssh2_msg_channel_open_failure");
7268 del234(ssh->channels, c);
7272 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7275 int typelen, want_reply;
7276 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7277 struct ssh_channel *c;
7278 struct Packet *pktout;
7280 c = ssh2_channel_msg(ssh, pktin);
7283 ssh_pkt_getstring(pktin, &type, &typelen);
7284 want_reply = ssh2_pkt_getbool(pktin);
7287 * Having got the channel number, we now look at
7288 * the request type string to see if it's something
7291 if (c == ssh->mainchan) {
7293 * We recognise "exit-status" and "exit-signal" on
7294 * the primary channel.
7296 if (typelen == 11 &&
7297 !memcmp(type, "exit-status", 11)) {
7299 ssh->exitcode = ssh_pkt_getuint32(pktin);
7300 logeventf(ssh, "Server sent command exit status %d",
7302 reply = SSH2_MSG_CHANNEL_SUCCESS;
7304 } else if (typelen == 11 &&
7305 !memcmp(type, "exit-signal", 11)) {
7307 int is_plausible = TRUE, is_int = FALSE;
7308 char *fmt_sig = "", *fmt_msg = "";
7310 int msglen = 0, core = FALSE;
7311 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7312 * provide an `int' for the signal, despite its
7313 * having been a `string' in the drafts of RFC 4254 since at
7314 * least 2001. (Fixed in session.c 1.147.) Try to
7315 * infer which we can safely parse it as. */
7317 unsigned char *p = pktin->body +
7319 long len = pktin->length - pktin->savedpos;
7320 unsigned long num = GET_32BIT(p); /* what is it? */
7321 /* If it's 0, it hardly matters; assume string */
7325 int maybe_int = FALSE, maybe_str = FALSE;
7326 #define CHECK_HYPOTHESIS(offset, result) \
7329 int q = toint(offset); \
7330 if (q >= 0 && q+4 <= len) { \
7331 q = toint(q + 4 + GET_32BIT(p+q)); \
7332 if (q >= 0 && q+4 <= len && \
7333 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7338 CHECK_HYPOTHESIS(4+1, maybe_int);
7339 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7340 #undef CHECK_HYPOTHESIS
7341 if (maybe_int && !maybe_str)
7343 else if (!maybe_int && maybe_str)
7346 /* Crikey. Either or neither. Panic. */
7347 is_plausible = FALSE;
7350 ssh->exitcode = 128; /* means `unknown signal' */
7353 /* Old non-standard OpenSSH. */
7354 int signum = ssh_pkt_getuint32(pktin);
7355 fmt_sig = dupprintf(" %d", signum);
7356 ssh->exitcode = 128 + signum;
7358 /* As per RFC 4254. */
7361 ssh_pkt_getstring(pktin, &sig, &siglen);
7362 /* Signal name isn't supposed to be blank, but
7363 * let's cope gracefully if it is. */
7365 fmt_sig = dupprintf(" \"%.*s\"",
7370 * Really hideous method of translating the
7371 * signal description back into a locally
7372 * meaningful number.
7377 #define TRANSLATE_SIGNAL(s) \
7378 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7379 ssh->exitcode = 128 + SIG ## s
7381 TRANSLATE_SIGNAL(ABRT);
7384 TRANSLATE_SIGNAL(ALRM);
7387 TRANSLATE_SIGNAL(FPE);
7390 TRANSLATE_SIGNAL(HUP);
7393 TRANSLATE_SIGNAL(ILL);
7396 TRANSLATE_SIGNAL(INT);
7399 TRANSLATE_SIGNAL(KILL);
7402 TRANSLATE_SIGNAL(PIPE);
7405 TRANSLATE_SIGNAL(QUIT);
7408 TRANSLATE_SIGNAL(SEGV);
7411 TRANSLATE_SIGNAL(TERM);
7414 TRANSLATE_SIGNAL(USR1);
7417 TRANSLATE_SIGNAL(USR2);
7419 #undef TRANSLATE_SIGNAL
7421 ssh->exitcode = 128;
7423 core = ssh2_pkt_getbool(pktin);
7424 ssh_pkt_getstring(pktin, &msg, &msglen);
7426 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7428 /* ignore lang tag */
7429 } /* else don't attempt to parse */
7430 logeventf(ssh, "Server exited on signal%s%s%s",
7431 fmt_sig, core ? " (core dumped)" : "",
7433 if (*fmt_sig) sfree(fmt_sig);
7434 if (*fmt_msg) sfree(fmt_msg);
7435 reply = SSH2_MSG_CHANNEL_SUCCESS;
7440 * This is a channel request we don't know
7441 * about, so we now either ignore the request
7442 * or respond with CHANNEL_FAILURE, depending
7445 reply = SSH2_MSG_CHANNEL_FAILURE;
7448 pktout = ssh2_pkt_init(reply);
7449 ssh2_pkt_adduint32(pktout, c->remoteid);
7450 ssh2_pkt_send(ssh, pktout);
7454 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7457 int typelen, want_reply;
7458 struct Packet *pktout;
7460 ssh_pkt_getstring(pktin, &type, &typelen);
7461 want_reply = ssh2_pkt_getbool(pktin);
7464 * We currently don't support any global requests
7465 * at all, so we either ignore the request or
7466 * respond with REQUEST_FAILURE, depending on
7470 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7471 ssh2_pkt_send(ssh, pktout);
7475 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7483 struct ssh_channel *c;
7484 unsigned remid, winsize, pktsize;
7485 struct Packet *pktout;
7487 ssh_pkt_getstring(pktin, &type, &typelen);
7488 c = snew(struct ssh_channel);
7491 remid = ssh_pkt_getuint32(pktin);
7492 winsize = ssh_pkt_getuint32(pktin);
7493 pktsize = ssh_pkt_getuint32(pktin);
7495 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7499 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7500 addrstr = snewn(peeraddrlen+1, char);
7501 memcpy(addrstr, peeraddr, peeraddrlen);
7502 addrstr[peeraddrlen] = '\0';
7503 peerport = ssh_pkt_getuint32(pktin);
7505 logeventf(ssh, "Received X11 connect request from %s:%d",
7508 if (!ssh->X11_fwd_enabled)
7509 error = "X11 forwarding is not enabled";
7510 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
7511 addrstr, peerport, ssh->conf)) != NULL) {
7512 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7513 error = "Unable to open an X11 connection";
7515 logevent("Opening X11 forward connection succeeded");
7520 } else if (typelen == 15 &&
7521 !memcmp(type, "forwarded-tcpip", 15)) {
7522 struct ssh_rportfwd pf, *realpf;
7525 ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */
7526 pf.shost = dupprintf("%.*s", shostlen, shost);
7527 pf.sport = ssh_pkt_getuint32(pktin);
7528 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7529 peerport = ssh_pkt_getuint32(pktin);
7530 realpf = find234(ssh->rportfwds, &pf, NULL);
7531 logeventf(ssh, "Received remote port %s:%d open request "
7532 "from %s:%d", pf.shost, pf.sport, peeraddr, peerport);
7535 if (realpf == NULL) {
7536 error = "Remote port is not recognised";
7538 const char *e = pfd_newconnect(&c->u.pfd.s,
7542 realpf->pfrec->addressfamily);
7543 logeventf(ssh, "Attempting to forward remote port to "
7544 "%s:%d", realpf->dhost, realpf->dport);
7546 logeventf(ssh, "Port open failed: %s", e);
7547 error = "Port open failed";
7549 logevent("Forwarded port opened successfully");
7550 c->type = CHAN_SOCKDATA;
7553 } else if (typelen == 22 &&
7554 !memcmp(type, "auth-agent@openssh.com", 22)) {
7555 if (!ssh->agentfwd_enabled)
7556 error = "Agent forwarding is not enabled";
7558 c->type = CHAN_AGENT; /* identify channel type */
7559 c->u.a.lensofar = 0;
7560 c->u.a.message = NULL;
7561 c->u.a.outstanding_requests = 0;
7564 error = "Unsupported channel type requested";
7567 c->remoteid = remid;
7568 c->halfopen = FALSE;
7570 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7571 ssh2_pkt_adduint32(pktout, c->remoteid);
7572 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7573 ssh2_pkt_addstring(pktout, error);
7574 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7575 ssh2_pkt_send(ssh, pktout);
7576 logeventf(ssh, "Rejected channel open: %s", error);
7579 ssh2_channel_init(c);
7580 c->v.v2.remwindow = winsize;
7581 c->v.v2.remmaxpkt = pktsize;
7582 add234(ssh->channels, c);
7583 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7584 ssh2_pkt_adduint32(pktout, c->remoteid);
7585 ssh2_pkt_adduint32(pktout, c->localid);
7586 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7587 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7588 ssh2_pkt_send(ssh, pktout);
7593 * Buffer banner messages for later display at some convenient point,
7594 * if we're going to display them.
7596 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7598 /* Arbitrary limit to prevent unbounded inflation of buffer */
7599 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
7600 bufchain_size(&ssh->banner) <= 131072) {
7601 char *banner = NULL;
7603 ssh_pkt_getstring(pktin, &banner, &size);
7605 bufchain_add(&ssh->banner, banner, size);
7609 /* Helper function to deal with sending tty modes for "pty-req" */
7610 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7612 struct Packet *pktout = (struct Packet *)data;
7614 unsigned int arg = 0;
7615 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7616 if (i == lenof(ssh_ttymodes)) return;
7617 switch (ssh_ttymodes[i].type) {
7619 arg = ssh_tty_parse_specchar(val);
7622 arg = ssh_tty_parse_boolean(val);
7625 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7626 ssh2_pkt_adduint32(pktout, arg);
7629 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
7632 struct ssh2_setup_x11_state {
7636 struct Packet *pktout;
7637 crStateP(ssh2_setup_x11_state, ctx);
7641 logevent("Requesting X11 forwarding");
7642 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
7644 ssh2_pkt_addbool(pktout, 0); /* many connections */
7645 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname);
7647 * Note that while we blank the X authentication data here, we don't
7648 * take any special action to blank the start of an X11 channel,
7649 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7650 * without having session blanking enabled is likely to leak your
7651 * cookie into the log.
7653 dont_log_password(ssh, pktout, PKTLOG_BLANK);
7654 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring);
7655 end_log_omission(ssh, pktout);
7656 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
7657 ssh2_pkt_send(ssh, pktout);
7659 /* Wait to be called back with either a response packet, or NULL
7660 * meaning clean up and free our data */
7664 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7665 logevent("X11 forwarding enabled");
7666 ssh->X11_fwd_enabled = TRUE;
7668 logevent("X11 forwarding refused");
7674 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
7677 struct ssh2_setup_agent_state {
7681 struct Packet *pktout;
7682 crStateP(ssh2_setup_agent_state, ctx);
7686 logevent("Requesting OpenSSH-style agent forwarding");
7687 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
7688 ssh2_setup_agent, s);
7689 ssh2_pkt_send(ssh, pktout);
7691 /* Wait to be called back with either a response packet, or NULL
7692 * meaning clean up and free our data */
7696 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7697 logevent("Agent forwarding enabled");
7698 ssh->agentfwd_enabled = TRUE;
7700 logevent("Agent forwarding refused");
7706 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
7709 struct ssh2_setup_pty_state {
7713 struct Packet *pktout;
7714 crStateP(ssh2_setup_pty_state, ctx);
7718 /* Unpick the terminal-speed string. */
7719 /* XXX perhaps we should allow no speeds to be sent. */
7720 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7721 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
7722 /* Build the pty request. */
7723 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
7725 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
7726 ssh2_pkt_adduint32(pktout, ssh->term_width);
7727 ssh2_pkt_adduint32(pktout, ssh->term_height);
7728 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
7729 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
7730 ssh2_pkt_addstring_start(pktout);
7731 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
7732 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
7733 ssh2_pkt_adduint32(pktout, ssh->ispeed);
7734 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
7735 ssh2_pkt_adduint32(pktout, ssh->ospeed);
7736 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
7737 ssh2_pkt_send(ssh, pktout);
7738 ssh->state = SSH_STATE_INTERMED;
7740 /* Wait to be called back with either a response packet, or NULL
7741 * meaning clean up and free our data */
7745 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7746 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7747 ssh->ospeed, ssh->ispeed);
7748 ssh->got_pty = TRUE;
7750 c_write_str(ssh, "Server refused to allocate pty\r\n");
7751 ssh->editing = ssh->echoing = 1;
7758 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
7761 struct ssh2_setup_env_state {
7763 int num_env, env_left, env_ok;
7766 struct Packet *pktout;
7767 crStateP(ssh2_setup_env_state, ctx);
7772 * Send environment variables.
7774 * Simplest thing here is to send all the requests at once, and
7775 * then wait for a whole bunch of successes or failures.
7781 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
7783 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
7784 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
7785 ssh2_pkt_addstring(pktout, key);
7786 ssh2_pkt_addstring(pktout, val);
7787 ssh2_pkt_send(ssh, pktout);
7792 logeventf(ssh, "Sent %d environment variables", s->num_env);
7797 s->env_left = s->num_env;
7799 while (s->env_left > 0) {
7800 /* Wait to be called back with either a response packet,
7801 * or NULL meaning clean up and free our data */
7803 if (!pktin) goto out;
7804 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
7809 if (s->env_ok == s->num_env) {
7810 logevent("All environment variables successfully set");
7811 } else if (s->env_ok == 0) {
7812 logevent("All environment variables refused");
7813 c_write_str(ssh, "Server refused to set environment variables\r\n");
7815 logeventf(ssh, "%d environment variables refused",
7816 s->num_env - s->env_ok);
7817 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7825 * Handle the SSH-2 userauth and connection layers.
7827 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
7829 do_ssh2_authconn(ssh, NULL, 0, pktin);
7832 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
7835 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
7838 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7839 struct Packet *pktin)
7841 struct do_ssh2_authconn_state {
7845 AUTH_TYPE_PUBLICKEY,
7846 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7847 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7849 AUTH_TYPE_GSSAPI, /* always QUIET */
7850 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7851 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7853 int done_service_req;
7854 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7855 int tried_pubkey_config, done_agent;
7860 int kbd_inter_refused;
7861 int we_are_in, userauth_success;
7862 prompts_t *cur_prompt;
7867 void *publickey_blob;
7868 int publickey_bloblen;
7869 int publickey_encrypted;
7870 char *publickey_algorithm;
7871 char *publickey_comment;
7872 unsigned char agent_request[5], *agent_response, *agentp;
7873 int agent_responselen;
7874 unsigned char *pkblob_in_agent;
7876 char *pkblob, *alg, *commentp;
7877 int pklen, alglen, commentlen;
7878 int siglen, retlen, len;
7879 char *q, *agentreq, *ret;
7881 struct Packet *pktout;
7884 struct ssh_gss_library *gsslib;
7885 Ssh_gss_ctx gss_ctx;
7886 Ssh_gss_buf gss_buf;
7887 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7888 Ssh_gss_name gss_srv_name;
7889 Ssh_gss_stat gss_stat;
7892 crState(do_ssh2_authconn_state);
7896 /* Register as a handler for all the messages this coroutine handles. */
7897 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
7898 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
7899 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
7900 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
7901 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
7902 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
7903 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7904 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7905 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
7906 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
7907 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
7908 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
7909 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
7910 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
7911 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
7912 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
7913 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
7914 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
7915 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
7916 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
7918 s->done_service_req = FALSE;
7919 s->we_are_in = s->userauth_success = FALSE;
7921 s->tried_gssapi = FALSE;
7924 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
7926 * Request userauth protocol, and await a response to it.
7928 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7929 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7930 ssh2_pkt_send(ssh, s->pktout);
7931 crWaitUntilV(pktin);
7932 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7933 s->done_service_req = TRUE;
7935 if (!s->done_service_req) {
7937 * Request connection protocol directly, without authentication.
7939 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7940 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7941 ssh2_pkt_send(ssh, s->pktout);
7942 crWaitUntilV(pktin);
7943 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7944 s->we_are_in = TRUE; /* no auth required */
7946 bombout(("Server refused service request"));
7951 /* Arrange to be able to deal with any BANNERs that come in.
7952 * (We do this now as packets may come in during the next bit.) */
7953 bufchain_init(&ssh->banner);
7954 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7955 ssh2_msg_userauth_banner;
7958 * Misc one-time setup for authentication.
7960 s->publickey_blob = NULL;
7961 if (!s->we_are_in) {
7964 * Load the public half of any configured public key file
7967 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
7968 if (!filename_is_null(s->keyfile)) {
7970 logeventf(ssh, "Reading private key file \"%.150s\"",
7971 filename_to_str(s->keyfile));
7972 keytype = key_type(s->keyfile);
7973 if (keytype == SSH_KEYTYPE_SSH2) {
7976 ssh2_userkey_loadpub(s->keyfile,
7977 &s->publickey_algorithm,
7978 &s->publickey_bloblen,
7979 &s->publickey_comment, &error);
7980 if (s->publickey_blob) {
7981 s->publickey_encrypted =
7982 ssh2_userkey_encrypted(s->keyfile, NULL);
7985 logeventf(ssh, "Unable to load private key (%s)",
7987 msgbuf = dupprintf("Unable to load private key file "
7988 "\"%.150s\" (%s)\r\n",
7989 filename_to_str(s->keyfile),
7991 c_write_str(ssh, msgbuf);
7996 logeventf(ssh, "Unable to use this key file (%s)",
7997 key_type_to_str(keytype));
7998 msgbuf = dupprintf("Unable to use key file \"%.150s\""
8000 filename_to_str(s->keyfile),
8001 key_type_to_str(keytype));
8002 c_write_str(ssh, msgbuf);
8004 s->publickey_blob = NULL;
8009 * Find out about any keys Pageant has (but if there's a
8010 * public key configured, filter out all others).
8013 s->agent_response = NULL;
8014 s->pkblob_in_agent = NULL;
8015 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
8019 logevent("Pageant is running. Requesting keys.");
8021 /* Request the keys held by the agent. */
8022 PUT_32BIT(s->agent_request, 1);
8023 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
8024 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
8025 ssh_agent_callback, ssh)) {
8029 bombout(("Unexpected data from server while"
8030 " waiting for agent response"));
8033 } while (pktin || inlen > 0);
8034 r = ssh->agent_response;
8035 s->agent_responselen = ssh->agent_response_len;
8037 s->agent_response = (unsigned char *) r;
8038 if (s->agent_response && s->agent_responselen >= 5 &&
8039 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
8042 p = s->agent_response + 5;
8043 s->nkeys = toint(GET_32BIT(p));
8046 * Vet the Pageant response to ensure that the key
8047 * count and blob lengths make sense.
8050 logeventf(ssh, "Pageant response contained a negative"
8051 " key count %d", s->nkeys);
8053 goto done_agent_query;
8055 unsigned char *q = p + 4;
8056 int lenleft = s->agent_responselen - 5 - 4;
8058 for (keyi = 0; keyi < s->nkeys; keyi++) {
8059 int bloblen, commentlen;
8061 logeventf(ssh, "Pageant response was truncated");
8063 goto done_agent_query;
8065 bloblen = toint(GET_32BIT(q));
8066 if (bloblen < 0 || bloblen > lenleft) {
8067 logeventf(ssh, "Pageant response was truncated");
8069 goto done_agent_query;
8071 lenleft -= 4 + bloblen;
8073 commentlen = toint(GET_32BIT(q));
8074 if (commentlen < 0 || commentlen > lenleft) {
8075 logeventf(ssh, "Pageant response was truncated");
8077 goto done_agent_query;
8079 lenleft -= 4 + commentlen;
8080 q += 4 + commentlen;
8085 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8086 if (s->publickey_blob) {
8087 /* See if configured key is in agent. */
8088 for (keyi = 0; keyi < s->nkeys; keyi++) {
8089 s->pklen = toint(GET_32BIT(p));
8090 if (s->pklen == s->publickey_bloblen &&
8091 !memcmp(p+4, s->publickey_blob,
8092 s->publickey_bloblen)) {
8093 logeventf(ssh, "Pageant key #%d matches "
8094 "configured key file", keyi);
8096 s->pkblob_in_agent = p;
8100 p += toint(GET_32BIT(p)) + 4; /* comment */
8102 if (!s->pkblob_in_agent) {
8103 logevent("Configured key file not in Pageant");
8108 logevent("Failed to get reply from Pageant");
8116 * We repeat this whole loop, including the username prompt,
8117 * until we manage a successful authentication. If the user
8118 * types the wrong _password_, they can be sent back to the
8119 * beginning to try another username, if this is configured on.
8120 * (If they specify a username in the config, they are never
8121 * asked, even if they do give a wrong password.)
8123 * I think this best serves the needs of
8125 * - the people who have no configuration, no keys, and just
8126 * want to try repeated (username,password) pairs until they
8127 * type both correctly
8129 * - people who have keys and configuration but occasionally
8130 * need to fall back to passwords
8132 * - people with a key held in Pageant, who might not have
8133 * logged in to a particular machine before; so they want to
8134 * type a username, and then _either_ their key will be
8135 * accepted, _or_ they will type a password. If they mistype
8136 * the username they will want to be able to get back and
8139 s->got_username = FALSE;
8140 while (!s->we_are_in) {
8144 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8146 * We got a username last time round this loop, and
8147 * with change_username turned off we don't try to get
8150 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8151 int ret; /* need not be kept over crReturn */
8152 s->cur_prompt = new_prompts(ssh->frontend);
8153 s->cur_prompt->to_server = TRUE;
8154 s->cur_prompt->name = dupstr("SSH login name");
8155 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8156 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8159 crWaitUntilV(!pktin);
8160 ret = get_userpass_input(s->cur_prompt, in, inlen);
8165 * get_userpass_input() failed to get a username.
8168 free_prompts(s->cur_prompt);
8169 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8172 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8173 free_prompts(s->cur_prompt);
8176 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8177 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8178 c_write_str(ssh, stuff);
8182 s->got_username = TRUE;
8185 * Send an authentication request using method "none": (a)
8186 * just in case it succeeds, and (b) so that we know what
8187 * authentication methods we can usefully try next.
8189 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8191 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8192 ssh2_pkt_addstring(s->pktout, ssh->username);
8193 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8194 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8195 ssh2_pkt_send(ssh, s->pktout);
8196 s->type = AUTH_TYPE_NONE;
8198 s->we_are_in = FALSE;
8200 s->tried_pubkey_config = FALSE;
8201 s->kbd_inter_refused = FALSE;
8203 /* Reset agent request state. */
8204 s->done_agent = FALSE;
8205 if (s->agent_response) {
8206 if (s->pkblob_in_agent) {
8207 s->agentp = s->pkblob_in_agent;
8209 s->agentp = s->agent_response + 5 + 4;
8215 char *methods = NULL;
8219 * Wait for the result of the last authentication request.
8222 crWaitUntilV(pktin);
8224 * Now is a convenient point to spew any banner material
8225 * that we've accumulated. (This should ensure that when
8226 * we exit the auth loop, we haven't any left to deal
8230 int size = bufchain_size(&ssh->banner);
8232 * Don't show the banner if we're operating in
8233 * non-verbose non-interactive mode. (It's probably
8234 * a script, which means nobody will read the
8235 * banner _anyway_, and moreover the printing of
8236 * the banner will screw up processing on the
8237 * output of (say) plink.)
8239 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8240 char *banner = snewn(size, char);
8241 bufchain_fetch(&ssh->banner, banner, size);
8242 c_write_untrusted(ssh, banner, size);
8245 bufchain_clear(&ssh->banner);
8247 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8248 logevent("Access granted");
8249 s->we_are_in = s->userauth_success = TRUE;
8253 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8254 bombout(("Strange packet received during authentication: "
8255 "type %d", pktin->type));
8262 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8263 * we can look at the string in it and know what we can
8264 * helpfully try next.
8266 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8267 ssh_pkt_getstring(pktin, &methods, &methlen);
8268 if (!ssh2_pkt_getbool(pktin)) {
8270 * We have received an unequivocal Access
8271 * Denied. This can translate to a variety of
8272 * messages, or no message at all.
8274 * For forms of authentication which are attempted
8275 * implicitly, by which I mean without printing
8276 * anything in the window indicating that we're
8277 * trying them, we should never print 'Access
8280 * If we do print a message saying that we're
8281 * attempting some kind of authentication, it's OK
8282 * to print a followup message saying it failed -
8283 * but the message may sometimes be more specific
8284 * than simply 'Access denied'.
8286 * Additionally, if we'd just tried password
8287 * authentication, we should break out of this
8288 * whole loop so as to go back to the username
8289 * prompt (iff we're configured to allow
8290 * username change attempts).
8292 if (s->type == AUTH_TYPE_NONE) {
8294 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8295 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8296 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8297 c_write_str(ssh, "Server refused our key\r\n");
8298 logevent("Server refused our key");
8299 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8300 /* This _shouldn't_ happen except by a
8301 * protocol bug causing client and server to
8302 * disagree on what is a correct signature. */
8303 c_write_str(ssh, "Server refused public-key signature"
8304 " despite accepting key!\r\n");
8305 logevent("Server refused public-key signature"
8306 " despite accepting key!");
8307 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8308 /* quiet, so no c_write */
8309 logevent("Server refused keyboard-interactive authentication");
8310 } else if (s->type==AUTH_TYPE_GSSAPI) {
8311 /* always quiet, so no c_write */
8312 /* also, the code down in the GSSAPI block has
8313 * already logged this in the Event Log */
8314 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8315 logevent("Keyboard-interactive authentication failed");
8316 c_write_str(ssh, "Access denied\r\n");
8318 assert(s->type == AUTH_TYPE_PASSWORD);
8319 logevent("Password authentication failed");
8320 c_write_str(ssh, "Access denied\r\n");
8322 if (conf_get_int(ssh->conf, CONF_change_username)) {
8323 /* XXX perhaps we should allow
8324 * keyboard-interactive to do this too? */
8325 s->we_are_in = FALSE;
8330 c_write_str(ssh, "Further authentication required\r\n");
8331 logevent("Further authentication required");
8335 in_commasep_string("publickey", methods, methlen);
8337 in_commasep_string("password", methods, methlen);
8338 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8339 in_commasep_string("keyboard-interactive", methods, methlen);
8342 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8343 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8344 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8345 ssh->gsslibs->nlibraries > 0;
8349 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8351 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8354 * Attempt public-key authentication using a key from Pageant.
8357 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8359 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8361 /* Unpack key from agent response */
8362 s->pklen = toint(GET_32BIT(s->agentp));
8364 s->pkblob = (char *)s->agentp;
8365 s->agentp += s->pklen;
8366 s->alglen = toint(GET_32BIT(s->pkblob));
8367 s->alg = s->pkblob + 4;
8368 s->commentlen = toint(GET_32BIT(s->agentp));
8370 s->commentp = (char *)s->agentp;
8371 s->agentp += s->commentlen;
8372 /* s->agentp now points at next key, if any */
8374 /* See if server will accept it */
8375 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8376 ssh2_pkt_addstring(s->pktout, ssh->username);
8377 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8378 /* service requested */
8379 ssh2_pkt_addstring(s->pktout, "publickey");
8381 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8382 ssh2_pkt_addstring_start(s->pktout);
8383 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8384 ssh2_pkt_addstring_start(s->pktout);
8385 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8386 ssh2_pkt_send(ssh, s->pktout);
8387 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8389 crWaitUntilV(pktin);
8390 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8392 /* Offer of key refused. */
8399 if (flags & FLAG_VERBOSE) {
8400 c_write_str(ssh, "Authenticating with "
8402 c_write(ssh, s->commentp, s->commentlen);
8403 c_write_str(ssh, "\" from agent\r\n");
8407 * Server is willing to accept the key.
8408 * Construct a SIGN_REQUEST.
8410 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8411 ssh2_pkt_addstring(s->pktout, ssh->username);
8412 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8413 /* service requested */
8414 ssh2_pkt_addstring(s->pktout, "publickey");
8416 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8417 ssh2_pkt_addstring_start(s->pktout);
8418 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8419 ssh2_pkt_addstring_start(s->pktout);
8420 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8422 /* Ask agent for signature. */
8423 s->siglen = s->pktout->length - 5 + 4 +
8424 ssh->v2_session_id_len;
8425 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8427 s->len = 1; /* message type */
8428 s->len += 4 + s->pklen; /* key blob */
8429 s->len += 4 + s->siglen; /* data to sign */
8430 s->len += 4; /* flags */
8431 s->agentreq = snewn(4 + s->len, char);
8432 PUT_32BIT(s->agentreq, s->len);
8433 s->q = s->agentreq + 4;
8434 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8435 PUT_32BIT(s->q, s->pklen);
8437 memcpy(s->q, s->pkblob, s->pklen);
8439 PUT_32BIT(s->q, s->siglen);
8441 /* Now the data to be signed... */
8442 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8443 PUT_32BIT(s->q, ssh->v2_session_id_len);
8446 memcpy(s->q, ssh->v2_session_id,
8447 ssh->v2_session_id_len);
8448 s->q += ssh->v2_session_id_len;
8449 memcpy(s->q, s->pktout->data + 5,
8450 s->pktout->length - 5);
8451 s->q += s->pktout->length - 5;
8452 /* And finally the (zero) flags word. */
8454 if (!agent_query(s->agentreq, s->len + 4,
8456 ssh_agent_callback, ssh)) {
8460 bombout(("Unexpected data from server"
8461 " while waiting for agent"
8465 } while (pktin || inlen > 0);
8466 vret = ssh->agent_response;
8467 s->retlen = ssh->agent_response_len;
8472 if (s->retlen >= 9 &&
8473 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
8474 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
8475 logevent("Sending Pageant's response");
8476 ssh2_add_sigblob(ssh, s->pktout,
8477 s->pkblob, s->pklen,
8479 GET_32BIT(s->ret + 5));
8480 ssh2_pkt_send(ssh, s->pktout);
8481 s->type = AUTH_TYPE_PUBLICKEY;
8483 /* FIXME: less drastic response */
8484 bombout(("Pageant failed to answer challenge"));
8490 /* Do we have any keys left to try? */
8491 if (s->pkblob_in_agent) {
8492 s->done_agent = TRUE;
8493 s->tried_pubkey_config = TRUE;
8496 if (s->keyi >= s->nkeys)
8497 s->done_agent = TRUE;
8500 } else if (s->can_pubkey && s->publickey_blob &&
8501 !s->tried_pubkey_config) {
8503 struct ssh2_userkey *key; /* not live over crReturn */
8504 char *passphrase; /* not live over crReturn */
8506 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8508 s->tried_pubkey_config = TRUE;
8511 * Try the public key supplied in the configuration.
8513 * First, offer the public blob to see if the server is
8514 * willing to accept it.
8516 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8517 ssh2_pkt_addstring(s->pktout, ssh->username);
8518 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8519 /* service requested */
8520 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8521 ssh2_pkt_addbool(s->pktout, FALSE);
8522 /* no signature included */
8523 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8524 ssh2_pkt_addstring_start(s->pktout);
8525 ssh2_pkt_addstring_data(s->pktout,
8526 (char *)s->publickey_blob,
8527 s->publickey_bloblen);
8528 ssh2_pkt_send(ssh, s->pktout);
8529 logevent("Offered public key");
8531 crWaitUntilV(pktin);
8532 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8533 /* Key refused. Give up. */
8534 s->gotit = TRUE; /* reconsider message next loop */
8535 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8536 continue; /* process this new message */
8538 logevent("Offer of public key accepted");
8541 * Actually attempt a serious authentication using
8544 if (flags & FLAG_VERBOSE) {
8545 c_write_str(ssh, "Authenticating with public key \"");
8546 c_write_str(ssh, s->publickey_comment);
8547 c_write_str(ssh, "\"\r\n");
8551 const char *error; /* not live over crReturn */
8552 if (s->publickey_encrypted) {
8554 * Get a passphrase from the user.
8556 int ret; /* need not be kept over crReturn */
8557 s->cur_prompt = new_prompts(ssh->frontend);
8558 s->cur_prompt->to_server = FALSE;
8559 s->cur_prompt->name = dupstr("SSH key passphrase");
8560 add_prompt(s->cur_prompt,
8561 dupprintf("Passphrase for key \"%.100s\": ",
8562 s->publickey_comment),
8564 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8567 crWaitUntilV(!pktin);
8568 ret = get_userpass_input(s->cur_prompt,
8573 /* Failed to get a passphrase. Terminate. */
8574 free_prompts(s->cur_prompt);
8575 ssh_disconnect(ssh, NULL,
8576 "Unable to authenticate",
8577 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8582 dupstr(s->cur_prompt->prompts[0]->result);
8583 free_prompts(s->cur_prompt);
8585 passphrase = NULL; /* no passphrase needed */
8589 * Try decrypting the key.
8591 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8592 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
8594 /* burn the evidence */
8595 smemclr(passphrase, strlen(passphrase));
8598 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8600 (key == SSH2_WRONG_PASSPHRASE)) {
8601 c_write_str(ssh, "Wrong passphrase\r\n");
8603 /* and loop again */
8605 c_write_str(ssh, "Unable to load private key (");
8606 c_write_str(ssh, error);
8607 c_write_str(ssh, ")\r\n");
8609 break; /* try something else */
8615 unsigned char *pkblob, *sigblob, *sigdata;
8616 int pkblob_len, sigblob_len, sigdata_len;
8620 * We have loaded the private key and the server
8621 * has announced that it's willing to accept it.
8622 * Hallelujah. Generate a signature and send it.
8624 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8625 ssh2_pkt_addstring(s->pktout, ssh->username);
8626 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8627 /* service requested */
8628 ssh2_pkt_addstring(s->pktout, "publickey");
8630 ssh2_pkt_addbool(s->pktout, TRUE);
8631 /* signature follows */
8632 ssh2_pkt_addstring(s->pktout, key->alg->name);
8633 pkblob = key->alg->public_blob(key->data,
8635 ssh2_pkt_addstring_start(s->pktout);
8636 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8640 * The data to be signed is:
8644 * followed by everything so far placed in the
8647 sigdata_len = s->pktout->length - 5 + 4 +
8648 ssh->v2_session_id_len;
8649 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8651 sigdata = snewn(sigdata_len, unsigned char);
8653 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8654 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8657 memcpy(sigdata+p, ssh->v2_session_id,
8658 ssh->v2_session_id_len);
8659 p += ssh->v2_session_id_len;
8660 memcpy(sigdata+p, s->pktout->data + 5,
8661 s->pktout->length - 5);
8662 p += s->pktout->length - 5;
8663 assert(p == sigdata_len);
8664 sigblob = key->alg->sign(key->data, (char *)sigdata,
8665 sigdata_len, &sigblob_len);
8666 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
8667 sigblob, sigblob_len);
8672 ssh2_pkt_send(ssh, s->pktout);
8673 logevent("Sent public key signature");
8674 s->type = AUTH_TYPE_PUBLICKEY;
8675 key->alg->freekey(key->data);
8679 } else if (s->can_gssapi && !s->tried_gssapi) {
8681 /* GSSAPI Authentication */
8686 s->type = AUTH_TYPE_GSSAPI;
8687 s->tried_gssapi = TRUE;
8689 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8692 * Pick the highest GSS library on the preference
8698 for (i = 0; i < ngsslibs; i++) {
8699 int want_id = conf_get_int_int(ssh->conf,
8700 CONF_ssh_gsslist, i);
8701 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8702 if (ssh->gsslibs->libraries[j].id == want_id) {
8703 s->gsslib = &ssh->gsslibs->libraries[j];
8704 goto got_gsslib; /* double break */
8709 * We always expect to have found something in
8710 * the above loop: we only came here if there
8711 * was at least one viable GSS library, and the
8712 * preference list should always mention
8713 * everything and only change the order.
8718 if (s->gsslib->gsslogmsg)
8719 logevent(s->gsslib->gsslogmsg);
8721 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8722 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8723 ssh2_pkt_addstring(s->pktout, ssh->username);
8724 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8725 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8726 logevent("Attempting GSSAPI authentication");
8728 /* add mechanism info */
8729 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8731 /* number of GSSAPI mechanisms */
8732 ssh2_pkt_adduint32(s->pktout,1);
8734 /* length of OID + 2 */
8735 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8736 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8739 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8741 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8743 ssh2_pkt_send(ssh, s->pktout);
8744 crWaitUntilV(pktin);
8745 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8746 logevent("GSSAPI authentication request refused");
8750 /* check returned packet ... */
8752 ssh_pkt_getstring(pktin, &data, &len);
8753 s->gss_rcvtok.value = data;
8754 s->gss_rcvtok.length = len;
8755 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8756 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8757 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8758 memcmp((char *)s->gss_rcvtok.value + 2,
8759 s->gss_buf.value,s->gss_buf.length) ) {
8760 logevent("GSSAPI authentication - wrong response from server");
8764 /* now start running */
8765 s->gss_stat = s->gsslib->import_name(s->gsslib,
8768 if (s->gss_stat != SSH_GSS_OK) {
8769 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8770 logevent("GSSAPI import name failed - Bad service name");
8772 logevent("GSSAPI import name failed");
8776 /* fetch TGT into GSS engine */
8777 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8779 if (s->gss_stat != SSH_GSS_OK) {
8780 logevent("GSSAPI authentication failed to get credentials");
8781 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8785 /* initial tokens are empty */
8786 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8787 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8789 /* now enter the loop */
8791 s->gss_stat = s->gsslib->init_sec_context
8795 conf_get_int(ssh->conf, CONF_gssapifwd),
8799 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8800 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8801 logevent("GSSAPI authentication initialisation failed");
8803 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8804 &s->gss_buf) == SSH_GSS_OK) {
8805 logevent(s->gss_buf.value);
8806 sfree(s->gss_buf.value);
8811 logevent("GSSAPI authentication initialised");
8813 /* Client and server now exchange tokens until GSSAPI
8814 * no longer says CONTINUE_NEEDED */
8816 if (s->gss_sndtok.length != 0) {
8817 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8818 ssh_pkt_addstring_start(s->pktout);
8819 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8820 ssh2_pkt_send(ssh, s->pktout);
8821 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8824 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8825 crWaitUntilV(pktin);
8826 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8827 logevent("GSSAPI authentication - bad server response");
8828 s->gss_stat = SSH_GSS_FAILURE;
8831 ssh_pkt_getstring(pktin, &data, &len);
8832 s->gss_rcvtok.value = data;
8833 s->gss_rcvtok.length = len;
8835 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8837 if (s->gss_stat != SSH_GSS_OK) {
8838 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8839 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8842 logevent("GSSAPI authentication loop finished OK");
8844 /* Now send the MIC */
8846 s->pktout = ssh2_pkt_init(0);
8847 micoffset = s->pktout->length;
8848 ssh_pkt_addstring_start(s->pktout);
8849 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8850 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8851 ssh_pkt_addstring(s->pktout, ssh->username);
8852 ssh_pkt_addstring(s->pktout, "ssh-connection");
8853 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8855 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8856 s->gss_buf.length = s->pktout->length - micoffset;
8858 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8859 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8860 ssh_pkt_addstring_start(s->pktout);
8861 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8862 ssh2_pkt_send(ssh, s->pktout);
8863 s->gsslib->free_mic(s->gsslib, &mic);
8867 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8868 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8871 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8874 * Keyboard-interactive authentication.
8877 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8879 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8881 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8882 ssh2_pkt_addstring(s->pktout, ssh->username);
8883 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8884 /* service requested */
8885 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8887 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8888 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8889 ssh2_pkt_send(ssh, s->pktout);
8891 logevent("Attempting keyboard-interactive authentication");
8893 crWaitUntilV(pktin);
8894 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8895 /* Server is not willing to do keyboard-interactive
8896 * at all (or, bizarrely but legally, accepts the
8897 * user without actually issuing any prompts).
8898 * Give up on it entirely. */
8900 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8901 s->kbd_inter_refused = TRUE; /* don't try it again */
8906 * Loop while the server continues to send INFO_REQUESTs.
8908 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8910 char *name, *inst, *lang;
8911 int name_len, inst_len, lang_len;
8915 * We've got a fresh USERAUTH_INFO_REQUEST.
8916 * Get the preamble and start building a prompt.
8918 ssh_pkt_getstring(pktin, &name, &name_len);
8919 ssh_pkt_getstring(pktin, &inst, &inst_len);
8920 ssh_pkt_getstring(pktin, &lang, &lang_len);
8921 s->cur_prompt = new_prompts(ssh->frontend);
8922 s->cur_prompt->to_server = TRUE;
8925 * Get any prompt(s) from the packet.
8927 s->num_prompts = ssh_pkt_getuint32(pktin);
8928 for (i = 0; i < s->num_prompts; i++) {
8932 static char noprompt[] =
8933 "<server failed to send prompt>: ";
8935 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8936 echo = ssh2_pkt_getbool(pktin);
8939 prompt_len = lenof(noprompt)-1;
8941 add_prompt(s->cur_prompt,
8942 dupprintf("%.*s", prompt_len, prompt),
8947 /* FIXME: better prefix to distinguish from
8949 s->cur_prompt->name =
8950 dupprintf("SSH server: %.*s", name_len, name);
8951 s->cur_prompt->name_reqd = TRUE;
8953 s->cur_prompt->name =
8954 dupstr("SSH server authentication");
8955 s->cur_prompt->name_reqd = FALSE;
8957 /* We add a prefix to try to make it clear that a prompt
8958 * has come from the server.
8959 * FIXME: ugly to print "Using..." in prompt _every_
8960 * time round. Can this be done more subtly? */
8961 /* Special case: for reasons best known to themselves,
8962 * some servers send k-i requests with no prompts and
8963 * nothing to display. Keep quiet in this case. */
8964 if (s->num_prompts || name_len || inst_len) {
8965 s->cur_prompt->instruction =
8966 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8967 inst_len ? "\n" : "", inst_len, inst);
8968 s->cur_prompt->instr_reqd = TRUE;
8970 s->cur_prompt->instr_reqd = FALSE;
8974 * Display any instructions, and get the user's
8978 int ret; /* not live over crReturn */
8979 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8982 crWaitUntilV(!pktin);
8983 ret = get_userpass_input(s->cur_prompt, in, inlen);
8988 * Failed to get responses. Terminate.
8990 free_prompts(s->cur_prompt);
8991 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8992 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8999 * Send the response(s) to the server.
9001 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
9002 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
9003 for (i=0; i < s->num_prompts; i++) {
9004 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9005 ssh2_pkt_addstring(s->pktout,
9006 s->cur_prompt->prompts[i]->result);
9007 end_log_omission(ssh, s->pktout);
9009 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9012 * Free the prompts structure from this iteration.
9013 * If there's another, a new one will be allocated
9014 * when we return to the top of this while loop.
9016 free_prompts(s->cur_prompt);
9019 * Get the next packet in case it's another
9022 crWaitUntilV(pktin);
9027 * We should have SUCCESS or FAILURE now.
9031 } else if (s->can_passwd) {
9034 * Plain old password authentication.
9036 int ret; /* not live over crReturn */
9037 int changereq_first_time; /* not live over crReturn */
9039 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
9041 s->cur_prompt = new_prompts(ssh->frontend);
9042 s->cur_prompt->to_server = TRUE;
9043 s->cur_prompt->name = dupstr("SSH password");
9044 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
9049 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9052 crWaitUntilV(!pktin);
9053 ret = get_userpass_input(s->cur_prompt, in, inlen);
9058 * Failed to get responses. Terminate.
9060 free_prompts(s->cur_prompt);
9061 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9062 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9067 * Squirrel away the password. (We may need it later if
9068 * asked to change it.)
9070 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9071 free_prompts(s->cur_prompt);
9074 * Send the password packet.
9076 * We pad out the password packet to 256 bytes to make
9077 * it harder for an attacker to find the length of the
9080 * Anyone using a password longer than 256 bytes
9081 * probably doesn't have much to worry about from
9082 * people who find out how long their password is!
9084 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9085 ssh2_pkt_addstring(s->pktout, ssh->username);
9086 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9087 /* service requested */
9088 ssh2_pkt_addstring(s->pktout, "password");
9089 ssh2_pkt_addbool(s->pktout, FALSE);
9090 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9091 ssh2_pkt_addstring(s->pktout, s->password);
9092 end_log_omission(ssh, s->pktout);
9093 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9094 logevent("Sent password");
9095 s->type = AUTH_TYPE_PASSWORD;
9098 * Wait for next packet, in case it's a password change
9101 crWaitUntilV(pktin);
9102 changereq_first_time = TRUE;
9104 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9107 * We're being asked for a new password
9108 * (perhaps not for the first time).
9109 * Loop until the server accepts it.
9112 int got_new = FALSE; /* not live over crReturn */
9113 char *prompt; /* not live over crReturn */
9114 int prompt_len; /* not live over crReturn */
9118 if (changereq_first_time)
9119 msg = "Server requested password change";
9121 msg = "Server rejected new password";
9123 c_write_str(ssh, msg);
9124 c_write_str(ssh, "\r\n");
9127 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9129 s->cur_prompt = new_prompts(ssh->frontend);
9130 s->cur_prompt->to_server = TRUE;
9131 s->cur_prompt->name = dupstr("New SSH password");
9132 s->cur_prompt->instruction =
9133 dupprintf("%.*s", prompt_len, prompt);
9134 s->cur_prompt->instr_reqd = TRUE;
9136 * There's no explicit requirement in the protocol
9137 * for the "old" passwords in the original and
9138 * password-change messages to be the same, and
9139 * apparently some Cisco kit supports password change
9140 * by the user entering a blank password originally
9141 * and the real password subsequently, so,
9142 * reluctantly, we prompt for the old password again.
9144 * (On the other hand, some servers don't even bother
9145 * to check this field.)
9147 add_prompt(s->cur_prompt,
9148 dupstr("Current password (blank for previously entered password): "),
9150 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9152 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9156 * Loop until the user manages to enter the same
9161 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9164 crWaitUntilV(!pktin);
9165 ret = get_userpass_input(s->cur_prompt, in, inlen);
9170 * Failed to get responses. Terminate.
9172 /* burn the evidence */
9173 free_prompts(s->cur_prompt);
9174 smemclr(s->password, strlen(s->password));
9176 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9177 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9183 * If the user specified a new original password
9184 * (IYSWIM), overwrite any previously specified
9186 * (A side effect is that the user doesn't have to
9187 * re-enter it if they louse up the new password.)
9189 if (s->cur_prompt->prompts[0]->result[0]) {
9190 smemclr(s->password, strlen(s->password));
9191 /* burn the evidence */
9194 dupstr(s->cur_prompt->prompts[0]->result);
9198 * Check the two new passwords match.
9200 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9201 s->cur_prompt->prompts[2]->result)
9204 /* They don't. Silly user. */
9205 c_write_str(ssh, "Passwords do not match\r\n");
9210 * Send the new password (along with the old one).
9211 * (see above for padding rationale)
9213 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9214 ssh2_pkt_addstring(s->pktout, ssh->username);
9215 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9216 /* service requested */
9217 ssh2_pkt_addstring(s->pktout, "password");
9218 ssh2_pkt_addbool(s->pktout, TRUE);
9219 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9220 ssh2_pkt_addstring(s->pktout, s->password);
9221 ssh2_pkt_addstring(s->pktout,
9222 s->cur_prompt->prompts[1]->result);
9223 free_prompts(s->cur_prompt);
9224 end_log_omission(ssh, s->pktout);
9225 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9226 logevent("Sent new password");
9229 * Now see what the server has to say about it.
9230 * (If it's CHANGEREQ again, it's not happy with the
9233 crWaitUntilV(pktin);
9234 changereq_first_time = FALSE;
9239 * We need to reexamine the current pktin at the top
9240 * of the loop. Either:
9241 * - we weren't asked to change password at all, in
9242 * which case it's a SUCCESS or FAILURE with the
9244 * - we sent a new password, and the server was
9245 * either OK with it (SUCCESS or FAILURE w/partial
9246 * success) or unhappy with the _old_ password
9247 * (FAILURE w/o partial success)
9248 * In any of these cases, we go back to the top of
9249 * the loop and start again.
9254 * We don't need the old password any more, in any
9255 * case. Burn the evidence.
9257 smemclr(s->password, strlen(s->password));
9261 char *str = dupprintf("No supported authentication methods available"
9262 " (server sent: %.*s)",
9265 ssh_disconnect(ssh, str,
9266 "No supported authentication methods available",
9267 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9277 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9279 /* Clear up various bits and pieces from authentication. */
9280 if (s->publickey_blob) {
9281 sfree(s->publickey_blob);
9282 sfree(s->publickey_comment);
9284 if (s->agent_response)
9285 sfree(s->agent_response);
9287 if (s->userauth_success) {
9289 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9290 * packets since. Signal the transport layer to consider enacting
9291 * delayed compression.
9293 * (Relying on we_are_in is not sufficient, as
9294 * draft-miller-secsh-compression-delayed is quite clear that it
9295 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9296 * become set for other reasons.)
9298 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9302 * Now the connection protocol has started, one way or another.
9305 ssh->channels = newtree234(ssh_channelcmp);
9308 * Set up handlers for some connection protocol messages, so we
9309 * don't have to handle them repeatedly in this coroutine.
9311 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9312 ssh2_msg_channel_window_adjust;
9313 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9314 ssh2_msg_global_request;
9317 * Create the main session channel.
9319 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9320 ssh->mainchan = NULL;
9322 ssh->mainchan = snew(struct ssh_channel);
9323 ssh->mainchan->ssh = ssh;
9324 ssh2_channel_init(ssh->mainchan);
9326 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9328 * Just start a direct-tcpip channel and use it as the main
9331 ssh_send_port_open(ssh->mainchan,
9332 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9333 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9337 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9338 logevent("Opening session as main channel");
9339 ssh2_pkt_send(ssh, s->pktout);
9340 ssh->ncmode = FALSE;
9342 crWaitUntilV(pktin);
9343 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9344 bombout(("Server refused to open channel"));
9346 /* FIXME: error data comes back in FAILURE packet */
9348 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9349 bombout(("Server's channel confirmation cited wrong channel"));
9352 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9353 ssh->mainchan->halfopen = FALSE;
9354 ssh->mainchan->type = CHAN_MAINSESSION;
9355 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9356 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9357 add234(ssh->channels, ssh->mainchan);
9358 update_specials_menu(ssh->frontend);
9359 logevent("Opened main channel");
9363 * Now we have a channel, make dispatch table entries for
9364 * general channel-based messages.
9366 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9367 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9368 ssh2_msg_channel_data;
9369 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9370 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9371 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9372 ssh2_msg_channel_open_confirmation;
9373 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9374 ssh2_msg_channel_open_failure;
9375 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9376 ssh2_msg_channel_request;
9377 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9378 ssh2_msg_channel_open;
9379 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9380 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9383 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
9385 * This message indicates to the server that we promise
9386 * not to try to run any other channel in parallel with
9387 * this one, so it's safe for it to advertise a very large
9388 * window and leave the flow control to TCP.
9390 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9391 "simple@putty.projects.tartarus.org",
9393 ssh2_pkt_send(ssh, s->pktout);
9397 * Enable port forwardings.
9399 ssh_setup_portfwd(ssh, ssh->conf);
9401 if (ssh->mainchan && !ssh->ncmode) {
9403 * Send the CHANNEL_REQUESTS for the main session channel.
9404 * Each one is handled by its own little asynchronous
9408 /* Potentially enable X11 forwarding. */
9409 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
9411 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9412 conf_get_int(ssh->conf, CONF_x11_auth),
9414 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
9416 /* Potentially enable agent forwarding. */
9417 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists())
9418 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
9420 /* Now allocate a pty for the session. */
9421 if (!conf_get_int(ssh->conf, CONF_nopty))
9422 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
9424 /* Send environment variables. */
9425 ssh2_setup_env(ssh->mainchan, NULL, NULL);
9428 * Start a shell or a remote command. We may have to attempt
9429 * this twice if the config data has provided a second choice
9436 if (ssh->fallback_cmd) {
9437 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9438 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
9440 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9441 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
9445 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
9446 ssh2_response_authconn, NULL);
9447 ssh2_pkt_addstring(s->pktout, cmd);
9449 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
9450 ssh2_response_authconn, NULL);
9451 ssh2_pkt_addstring(s->pktout, cmd);
9453 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
9454 ssh2_response_authconn, NULL);
9456 ssh2_pkt_send(ssh, s->pktout);
9458 crWaitUntilV(pktin);
9460 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9461 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9462 bombout(("Unexpected response to shell/command request:"
9463 " packet type %d", pktin->type));
9467 * We failed to start the command. If this is the
9468 * fallback command, we really are finished; if it's
9469 * not, and if the fallback command exists, try falling
9470 * back to it before complaining.
9472 if (!ssh->fallback_cmd &&
9473 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
9474 logevent("Primary command failed; attempting fallback");
9475 ssh->fallback_cmd = TRUE;
9478 bombout(("Server refused to start a shell/command"));
9481 logevent("Started a shell/command");
9486 ssh->editing = ssh->echoing = TRUE;
9489 ssh->state = SSH_STATE_SESSION;
9490 if (ssh->size_needed)
9491 ssh_size(ssh, ssh->term_width, ssh->term_height);
9492 if (ssh->eof_needed)
9493 ssh_special(ssh, TS_EOF);
9499 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
9504 s->try_send = FALSE;
9508 * _All_ the connection-layer packets we expect to
9509 * receive are now handled by the dispatch table.
9510 * Anything that reaches here must be bogus.
9513 bombout(("Strange packet received: type %d", pktin->type));
9515 } else if (ssh->mainchan) {
9517 * We have spare data. Add it to the channel buffer.
9519 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9524 struct ssh_channel *c;
9526 * Try to send data on all channels if we can.
9528 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9529 ssh2_try_send_and_unthrottle(ssh, c);
9537 * Handlers for SSH-2 messages that might arrive at any moment.
9539 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9541 /* log reason code in disconnect message */
9545 reason = ssh_pkt_getuint32(pktin);
9546 ssh_pkt_getstring(pktin, &msg, &msglen);
9548 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9549 buf = dupprintf("Received disconnect message (%s)",
9550 ssh2_disconnect_reasons[reason]);
9552 buf = dupprintf("Received disconnect message (unknown"
9553 " type %d)", reason);
9557 buf = dupprintf("Disconnection message text: %.*s",
9560 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9562 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9563 ssh2_disconnect_reasons[reason] : "unknown",
9568 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9570 /* log the debug message */
9574 /* XXX maybe we should actually take notice of the return value */
9575 ssh2_pkt_getbool(pktin);
9576 ssh_pkt_getstring(pktin, &msg, &msglen);
9578 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9581 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
9583 do_ssh2_transport(ssh, NULL, 0, pktin);
9587 * Called if we receive a packet that isn't allowed by the protocol.
9588 * This only applies to packets whose meaning PuTTY understands.
9589 * Entirely unknown packets are handled below.
9591 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
9593 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
9594 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
9596 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
9600 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9602 struct Packet *pktout;
9603 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9604 ssh2_pkt_adduint32(pktout, pktin->sequence);
9606 * UNIMPLEMENTED messages MUST appear in the same order as the
9607 * messages they respond to. Hence, never queue them.
9609 ssh2_pkt_send_noqueue(ssh, pktout);
9613 * Handle the top-level SSH-2 protocol.
9615 static void ssh2_protocol_setup(Ssh ssh)
9620 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9622 for (i = 0; i < 256; i++)
9623 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9626 * Initially, we only accept transport messages (and a few generic
9627 * ones). do_ssh2_authconn will add more when it starts.
9628 * Messages that are understood but not currently acceptable go to
9629 * ssh2_msg_unexpected.
9631 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
9632 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
9633 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
9634 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
9635 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
9636 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
9637 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
9638 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9639 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9640 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
9641 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
9642 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
9643 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
9644 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
9645 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
9646 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
9647 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9648 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9649 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
9650 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
9651 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
9652 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
9653 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
9654 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
9655 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
9656 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
9657 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
9658 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
9659 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
9660 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
9661 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
9662 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
9663 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
9666 * These messages have a special handler from the start.
9668 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9669 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9670 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9673 static void ssh2_timer(void *ctx, unsigned long now)
9677 if (ssh->state == SSH_STATE_CLOSED)
9680 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9681 now == ssh->next_rekey) {
9682 do_ssh2_transport(ssh, "timeout", -1, NULL);
9686 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9687 struct Packet *pktin)
9689 unsigned char *in = (unsigned char *)vin;
9690 if (ssh->state == SSH_STATE_CLOSED)
9694 ssh->incoming_data_size += pktin->encrypted_len;
9695 if (!ssh->kex_in_progress &&
9696 ssh->max_data_size != 0 &&
9697 ssh->incoming_data_size > ssh->max_data_size)
9698 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9702 ssh->packet_dispatch[pktin->type](ssh, pktin);
9703 else if (!ssh->protocol_initial_phase_done)
9704 do_ssh2_transport(ssh, in, inlen, pktin);
9706 do_ssh2_authconn(ssh, in, inlen, pktin);
9709 static void ssh_cache_conf_values(Ssh ssh)
9711 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9715 * Called to set up the connection.
9717 * Returns an error message, or NULL on success.
9719 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9720 Conf *conf, char *host, int port, char **realhost,
9721 int nodelay, int keepalive)
9726 ssh = snew(struct ssh_tag);
9727 ssh->conf = conf_copy(conf);
9728 ssh_cache_conf_values(ssh);
9729 ssh->version = 0; /* when not ready yet */
9732 ssh->v1_cipher_ctx = NULL;
9733 ssh->crcda_ctx = NULL;
9734 ssh->cscipher = NULL;
9735 ssh->cs_cipher_ctx = NULL;
9736 ssh->sccipher = NULL;
9737 ssh->sc_cipher_ctx = NULL;
9739 ssh->cs_mac_ctx = NULL;
9741 ssh->sc_mac_ctx = NULL;
9743 ssh->cs_comp_ctx = NULL;
9745 ssh->sc_comp_ctx = NULL;
9747 ssh->kex_ctx = NULL;
9748 ssh->hostkey = NULL;
9749 ssh->hostkey_str = NULL;
9751 ssh->close_expected = FALSE;
9752 ssh->clean_exit = FALSE;
9753 ssh->state = SSH_STATE_PREPACKET;
9754 ssh->size_needed = FALSE;
9755 ssh->eof_needed = FALSE;
9758 ssh->deferred_send_data = NULL;
9759 ssh->deferred_len = 0;
9760 ssh->deferred_size = 0;
9761 ssh->fallback_cmd = 0;
9762 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9763 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9764 ssh->x11disp = NULL;
9765 ssh->v1_compressing = FALSE;
9766 ssh->v2_outgoing_sequence = 0;
9767 ssh->ssh1_rdpkt_crstate = 0;
9768 ssh->ssh2_rdpkt_crstate = 0;
9769 ssh->ssh_gotdata_crstate = 0;
9770 ssh->do_ssh1_connection_crstate = 0;
9771 ssh->do_ssh_init_state = NULL;
9772 ssh->do_ssh1_login_state = NULL;
9773 ssh->do_ssh2_transport_state = NULL;
9774 ssh->do_ssh2_authconn_state = NULL;
9777 ssh->mainchan = NULL;
9778 ssh->throttled_all = 0;
9779 ssh->v1_stdout_throttling = 0;
9781 ssh->queuelen = ssh->queuesize = 0;
9782 ssh->queueing = FALSE;
9783 ssh->qhead = ssh->qtail = NULL;
9784 ssh->deferred_rekey_reason = NULL;
9785 bufchain_init(&ssh->queued_incoming_data);
9786 ssh->frozen = FALSE;
9787 ssh->username = NULL;
9788 ssh->sent_console_eof = FALSE;
9789 ssh->got_pty = FALSE;
9791 *backend_handle = ssh;
9794 if (crypto_startup() == 0)
9795 return "Microsoft high encryption pack not installed!";
9798 ssh->frontend = frontend_handle;
9799 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9800 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
9802 ssh->channels = NULL;
9803 ssh->rportfwds = NULL;
9804 ssh->portfwds = NULL;
9809 ssh->conn_throttle_count = 0;
9810 ssh->overall_bufsize = 0;
9811 ssh->fallback_cmd = 0;
9813 ssh->protocol = NULL;
9815 ssh->protocol_initial_phase_done = FALSE;
9819 ssh->incoming_data_size = ssh->outgoing_data_size =
9820 ssh->deferred_data_size = 0L;
9821 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9822 CONF_ssh_rekey_data));
9823 ssh->kex_in_progress = FALSE;
9826 ssh->gsslibs = NULL;
9829 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9838 static void ssh_free(void *handle)
9840 Ssh ssh = (Ssh) handle;
9841 struct ssh_channel *c;
9842 struct ssh_rportfwd *pf;
9844 if (ssh->v1_cipher_ctx)
9845 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9846 if (ssh->cs_cipher_ctx)
9847 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9848 if (ssh->sc_cipher_ctx)
9849 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9850 if (ssh->cs_mac_ctx)
9851 ssh->csmac->free_context(ssh->cs_mac_ctx);
9852 if (ssh->sc_mac_ctx)
9853 ssh->scmac->free_context(ssh->sc_mac_ctx);
9854 if (ssh->cs_comp_ctx) {
9856 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9858 zlib_compress_cleanup(ssh->cs_comp_ctx);
9860 if (ssh->sc_comp_ctx) {
9862 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9864 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9867 dh_cleanup(ssh->kex_ctx);
9868 sfree(ssh->savedhost);
9870 while (ssh->queuelen-- > 0)
9871 ssh_free_packet(ssh->queue[ssh->queuelen]);
9874 while (ssh->qhead) {
9875 struct queued_handler *qh = ssh->qhead;
9876 ssh->qhead = qh->next;
9879 ssh->qhead = ssh->qtail = NULL;
9881 if (ssh->channels) {
9882 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9885 if (c->u.x11.s != NULL)
9886 x11_close(c->u.x11.s);
9889 case CHAN_SOCKDATA_DORMANT:
9890 if (c->u.pfd.s != NULL)
9891 pfd_close(c->u.pfd.s);
9894 if (ssh->version == 2) {
9895 struct outstanding_channel_request *ocr, *nocr;
9896 ocr = c->v.v2.chanreq_head;
9898 ocr->handler(c, NULL, ocr->ctx);
9903 bufchain_clear(&c->v.v2.outbuffer);
9907 freetree234(ssh->channels);
9908 ssh->channels = NULL;
9911 if (ssh->rportfwds) {
9912 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9914 freetree234(ssh->rportfwds);
9915 ssh->rportfwds = NULL;
9917 sfree(ssh->deferred_send_data);
9919 x11_free_display(ssh->x11disp);
9920 sfree(ssh->do_ssh_init_state);
9921 sfree(ssh->do_ssh1_login_state);
9922 sfree(ssh->do_ssh2_transport_state);
9923 sfree(ssh->do_ssh2_authconn_state);
9926 sfree(ssh->fullhostname);
9927 sfree(ssh->hostkey_str);
9928 if (ssh->crcda_ctx) {
9929 crcda_free_context(ssh->crcda_ctx);
9930 ssh->crcda_ctx = NULL;
9933 ssh_do_close(ssh, TRUE);
9934 expire_timer_context(ssh);
9936 pinger_free(ssh->pinger);
9937 bufchain_clear(&ssh->queued_incoming_data);
9938 sfree(ssh->username);
9939 conf_free(ssh->conf);
9942 ssh_gss_cleanup(ssh->gsslibs);
9950 * Reconfigure the SSH backend.
9952 static void ssh_reconfig(void *handle, Conf *conf)
9954 Ssh ssh = (Ssh) handle;
9955 char *rekeying = NULL, rekey_mandatory = FALSE;
9956 unsigned long old_max_data_size;
9959 pinger_reconfig(ssh->pinger, ssh->conf, conf);
9961 ssh_setup_portfwd(ssh, conf);
9963 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9964 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9966 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
9967 unsigned long now = GETTICKCOUNT();
9969 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
9970 rekeying = "timeout shortened";
9972 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9976 old_max_data_size = ssh->max_data_size;
9977 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9978 CONF_ssh_rekey_data));
9979 if (old_max_data_size != ssh->max_data_size &&
9980 ssh->max_data_size != 0) {
9981 if (ssh->outgoing_data_size > ssh->max_data_size ||
9982 ssh->incoming_data_size > ssh->max_data_size)
9983 rekeying = "data limit lowered";
9986 if (conf_get_int(ssh->conf, CONF_compression) !=
9987 conf_get_int(conf, CONF_compression)) {
9988 rekeying = "compression setting changed";
9989 rekey_mandatory = TRUE;
9992 for (i = 0; i < CIPHER_MAX; i++)
9993 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
9994 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
9995 rekeying = "cipher settings changed";
9996 rekey_mandatory = TRUE;
9998 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
9999 conf_get_int(conf, CONF_ssh2_des_cbc)) {
10000 rekeying = "cipher settings changed";
10001 rekey_mandatory = TRUE;
10004 conf_free(ssh->conf);
10005 ssh->conf = conf_copy(conf);
10006 ssh_cache_conf_values(ssh);
10009 if (!ssh->kex_in_progress) {
10010 do_ssh2_transport(ssh, rekeying, -1, NULL);
10011 } else if (rekey_mandatory) {
10012 ssh->deferred_rekey_reason = rekeying;
10018 * Called to send data down the SSH connection.
10020 static int ssh_send(void *handle, char *buf, int len)
10022 Ssh ssh = (Ssh) handle;
10024 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10027 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
10029 return ssh_sendbuffer(ssh);
10033 * Called to query the current amount of buffered stdin data.
10035 static int ssh_sendbuffer(void *handle)
10037 Ssh ssh = (Ssh) handle;
10038 int override_value;
10040 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
10044 * If the SSH socket itself has backed up, add the total backup
10045 * size on that to any individual buffer on the stdin channel.
10047 override_value = 0;
10048 if (ssh->throttled_all)
10049 override_value = ssh->overall_bufsize;
10051 if (ssh->version == 1) {
10052 return override_value;
10053 } else if (ssh->version == 2) {
10054 if (!ssh->mainchan)
10055 return override_value;
10057 return (override_value +
10058 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
10065 * Called to set the size of the window from SSH's POV.
10067 static void ssh_size(void *handle, int width, int height)
10069 Ssh ssh = (Ssh) handle;
10070 struct Packet *pktout;
10072 ssh->term_width = width;
10073 ssh->term_height = height;
10075 switch (ssh->state) {
10076 case SSH_STATE_BEFORE_SIZE:
10077 case SSH_STATE_PREPACKET:
10078 case SSH_STATE_CLOSED:
10079 break; /* do nothing */
10080 case SSH_STATE_INTERMED:
10081 ssh->size_needed = TRUE; /* buffer for later */
10083 case SSH_STATE_SESSION:
10084 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10085 if (ssh->version == 1) {
10086 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10087 PKT_INT, ssh->term_height,
10088 PKT_INT, ssh->term_width,
10089 PKT_INT, 0, PKT_INT, 0, PKT_END);
10090 } else if (ssh->mainchan) {
10091 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10093 ssh2_pkt_adduint32(pktout, ssh->term_width);
10094 ssh2_pkt_adduint32(pktout, ssh->term_height);
10095 ssh2_pkt_adduint32(pktout, 0);
10096 ssh2_pkt_adduint32(pktout, 0);
10097 ssh2_pkt_send(ssh, pktout);
10105 * Return a list of the special codes that make sense in this
10108 static const struct telnet_special *ssh_get_specials(void *handle)
10110 static const struct telnet_special ssh1_ignore_special[] = {
10111 {"IGNORE message", TS_NOP}
10113 static const struct telnet_special ssh2_ignore_special[] = {
10114 {"IGNORE message", TS_NOP},
10116 static const struct telnet_special ssh2_rekey_special[] = {
10117 {"Repeat key exchange", TS_REKEY},
10119 static const struct telnet_special ssh2_session_specials[] = {
10122 /* These are the signal names defined by RFC 4254.
10123 * They include all the ISO C signals, but are a subset of the POSIX
10124 * required signals. */
10125 {"SIGINT (Interrupt)", TS_SIGINT},
10126 {"SIGTERM (Terminate)", TS_SIGTERM},
10127 {"SIGKILL (Kill)", TS_SIGKILL},
10128 {"SIGQUIT (Quit)", TS_SIGQUIT},
10129 {"SIGHUP (Hangup)", TS_SIGHUP},
10130 {"More signals", TS_SUBMENU},
10131 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10132 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10133 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10134 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10135 {NULL, TS_EXITMENU}
10137 static const struct telnet_special specials_end[] = {
10138 {NULL, TS_EXITMENU}
10140 /* XXX review this length for any changes: */
10141 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10142 lenof(ssh2_rekey_special) +
10143 lenof(ssh2_session_specials) +
10144 lenof(specials_end)];
10145 Ssh ssh = (Ssh) handle;
10147 #define ADD_SPECIALS(name) \
10149 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10150 memcpy(&ssh_specials[i], name, sizeof name); \
10151 i += lenof(name); \
10154 if (ssh->version == 1) {
10155 /* Don't bother offering IGNORE if we've decided the remote
10156 * won't cope with it, since we wouldn't bother sending it if
10158 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10159 ADD_SPECIALS(ssh1_ignore_special);
10160 } else if (ssh->version == 2) {
10161 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10162 ADD_SPECIALS(ssh2_ignore_special);
10163 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
10164 ADD_SPECIALS(ssh2_rekey_special);
10166 ADD_SPECIALS(ssh2_session_specials);
10167 } /* else we're not ready yet */
10170 ADD_SPECIALS(specials_end);
10171 return ssh_specials;
10175 #undef ADD_SPECIALS
10179 * Send special codes. TS_EOF is useful for `plink', so you
10180 * can send an EOF and collect resulting output (e.g. `plink
10183 static void ssh_special(void *handle, Telnet_Special code)
10185 Ssh ssh = (Ssh) handle;
10186 struct Packet *pktout;
10188 if (code == TS_EOF) {
10189 if (ssh->state != SSH_STATE_SESSION) {
10191 * Buffer the EOF in case we are pre-SESSION, so we can
10192 * send it as soon as we reach SESSION.
10194 if (code == TS_EOF)
10195 ssh->eof_needed = TRUE;
10198 if (ssh->version == 1) {
10199 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10200 } else if (ssh->mainchan) {
10201 sshfwd_write_eof(ssh->mainchan);
10202 ssh->send_ok = 0; /* now stop trying to read from stdin */
10204 logevent("Sent EOF message");
10205 } else if (code == TS_PING || code == TS_NOP) {
10206 if (ssh->state == SSH_STATE_CLOSED
10207 || ssh->state == SSH_STATE_PREPACKET) return;
10208 if (ssh->version == 1) {
10209 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10210 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10212 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10213 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10214 ssh2_pkt_addstring_start(pktout);
10215 ssh2_pkt_send_noqueue(ssh, pktout);
10218 } else if (code == TS_REKEY) {
10219 if (!ssh->kex_in_progress && ssh->version == 2) {
10220 do_ssh2_transport(ssh, "at user request", -1, NULL);
10222 } else if (code == TS_BRK) {
10223 if (ssh->state == SSH_STATE_CLOSED
10224 || ssh->state == SSH_STATE_PREPACKET) return;
10225 if (ssh->version == 1) {
10226 logevent("Unable to send BREAK signal in SSH-1");
10227 } else if (ssh->mainchan) {
10228 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10229 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10230 ssh2_pkt_send(ssh, pktout);
10233 /* Is is a POSIX signal? */
10234 char *signame = NULL;
10235 if (code == TS_SIGABRT) signame = "ABRT";
10236 if (code == TS_SIGALRM) signame = "ALRM";
10237 if (code == TS_SIGFPE) signame = "FPE";
10238 if (code == TS_SIGHUP) signame = "HUP";
10239 if (code == TS_SIGILL) signame = "ILL";
10240 if (code == TS_SIGINT) signame = "INT";
10241 if (code == TS_SIGKILL) signame = "KILL";
10242 if (code == TS_SIGPIPE) signame = "PIPE";
10243 if (code == TS_SIGQUIT) signame = "QUIT";
10244 if (code == TS_SIGSEGV) signame = "SEGV";
10245 if (code == TS_SIGTERM) signame = "TERM";
10246 if (code == TS_SIGUSR1) signame = "USR1";
10247 if (code == TS_SIGUSR2) signame = "USR2";
10248 /* The SSH-2 protocol does in principle support arbitrary named
10249 * signals, including signame@domain, but we don't support those. */
10251 /* It's a signal. */
10252 if (ssh->version == 2 && ssh->mainchan) {
10253 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10254 ssh2_pkt_addstring(pktout, signame);
10255 ssh2_pkt_send(ssh, pktout);
10256 logeventf(ssh, "Sent signal SIG%s", signame);
10259 /* Never heard of it. Do nothing */
10264 void *new_sock_channel(void *handle, Socket s)
10266 Ssh ssh = (Ssh) handle;
10267 struct ssh_channel *c;
10268 c = snew(struct ssh_channel);
10271 ssh2_channel_init(c);
10272 c->halfopen = TRUE;
10273 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10275 add234(ssh->channels, c);
10280 * This is called when stdout/stderr (the entity to which
10281 * from_backend sends data) manages to clear some backlog.
10283 static void ssh_unthrottle(void *handle, int bufsize)
10285 Ssh ssh = (Ssh) handle;
10288 if (ssh->version == 1) {
10289 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10290 ssh->v1_stdout_throttling = 0;
10291 ssh_throttle_conn(ssh, -1);
10294 if (ssh->mainchan) {
10295 ssh2_set_window(ssh->mainchan,
10296 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10297 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10298 if (conf_get_int(ssh->conf, CONF_ssh_simple))
10301 buflimit = ssh->mainchan->v.v2.locmaxwin;
10302 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10303 ssh->mainchan->throttling_conn = 0;
10304 ssh_throttle_conn(ssh, -1);
10310 * Now process any SSH connection data that was stashed in our
10311 * queue while we were frozen.
10313 ssh_process_queued_incoming_data(ssh);
10316 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
10318 struct ssh_channel *c = (struct ssh_channel *)channel;
10320 struct Packet *pktout;
10322 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
10324 if (ssh->version == 1) {
10325 send_packet(ssh, SSH1_MSG_PORT_OPEN,
10326 PKT_INT, c->localid,
10329 /* PKT_STR, <org:orgport>, */
10332 pktout = ssh2_chanopen_init(c, "direct-tcpip");
10333 ssh2_pkt_addstring(pktout, hostname);
10334 ssh2_pkt_adduint32(pktout, port);
10336 * We make up values for the originator data; partly it's
10337 * too much hassle to keep track, and partly I'm not
10338 * convinced the server should be told details like that
10339 * about my local network configuration.
10340 * The "originator IP address" is syntactically a numeric
10341 * IP address, and some servers (e.g., Tectia) get upset
10342 * if it doesn't match this syntax.
10344 ssh2_pkt_addstring(pktout, "0.0.0.0");
10345 ssh2_pkt_adduint32(pktout, 0);
10346 ssh2_pkt_send(ssh, pktout);
10350 static int ssh_connected(void *handle)
10352 Ssh ssh = (Ssh) handle;
10353 return ssh->s != NULL;
10356 static int ssh_sendok(void *handle)
10358 Ssh ssh = (Ssh) handle;
10359 return ssh->send_ok;
10362 static int ssh_ldisc(void *handle, int option)
10364 Ssh ssh = (Ssh) handle;
10365 if (option == LD_ECHO)
10366 return ssh->echoing;
10367 if (option == LD_EDIT)
10368 return ssh->editing;
10372 static void ssh_provide_ldisc(void *handle, void *ldisc)
10374 Ssh ssh = (Ssh) handle;
10375 ssh->ldisc = ldisc;
10378 static void ssh_provide_logctx(void *handle, void *logctx)
10380 Ssh ssh = (Ssh) handle;
10381 ssh->logctx = logctx;
10384 static int ssh_return_exitcode(void *handle)
10386 Ssh ssh = (Ssh) handle;
10387 if (ssh->s != NULL)
10390 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
10394 * cfg_info for SSH is the currently running version of the
10395 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10397 static int ssh_cfg_info(void *handle)
10399 Ssh ssh = (Ssh) handle;
10400 return ssh->version;
10404 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10405 * that fails. This variable is the means by which scp.c can reach
10406 * into the SSH code and find out which one it got.
10408 extern int ssh_fallback_cmd(void *handle)
10410 Ssh ssh = (Ssh) handle;
10411 return ssh->fallback_cmd;
10414 Backend ssh_backend = {
10424 ssh_return_exitcode,
10428 ssh_provide_logctx,