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;
715 #define free_rportfwd(pf) ( \
716 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
719 * Separately to the rportfwd tree (which is for looking up port
720 * open requests from the server), a tree of _these_ structures is
721 * used to keep track of all the currently open port forwardings,
722 * so that we can reconfigure in mid-session if the user requests
726 enum { DESTROY, KEEP, CREATE } status;
728 unsigned sport, dport;
731 struct ssh_rportfwd *remote;
735 #define free_portfwd(pf) ( \
736 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
737 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
740 long length; /* length of `data' actually used */
741 long forcepad; /* SSH-2: force padding to at least this length */
742 int type; /* only used for incoming packets */
743 unsigned long sequence; /* SSH-2 incoming sequence number */
744 unsigned char *data; /* allocated storage */
745 unsigned char *body; /* offset of payload within `data' */
746 long savedpos; /* temporary index into `data' (for strings) */
747 long maxlen; /* amount of storage allocated for `data' */
748 long encrypted_len; /* for SSH-2 total-size counting */
751 * State associated with packet logging
755 struct logblank_t *blanks;
758 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
759 struct Packet *pktin);
760 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
761 struct Packet *pktin);
762 static void ssh1_protocol_setup(Ssh ssh);
763 static void ssh2_protocol_setup(Ssh ssh);
764 static void ssh_size(void *handle, int width, int height);
765 static void ssh_special(void *handle, Telnet_Special);
766 static int ssh2_try_send(struct ssh_channel *c);
767 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
768 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
769 static void ssh2_set_window(struct ssh_channel *c, int newwin);
770 static int ssh_sendbuffer(void *handle);
771 static int ssh_do_close(Ssh ssh, int notify_exit);
772 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
773 static int ssh2_pkt_getbool(struct Packet *pkt);
774 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
775 static void ssh2_timer(void *ctx, unsigned long now);
776 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
777 struct Packet *pktin);
778 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin);
780 struct rdpkt1_state_tag {
781 long len, pad, biglen, to_read;
782 unsigned long realcrc, gotcrc;
786 struct Packet *pktin;
789 struct rdpkt2_state_tag {
790 long len, pad, payload, packetlen, maclen;
793 unsigned long incoming_sequence;
794 struct Packet *pktin;
797 struct queued_handler;
798 struct queued_handler {
800 chandler_fn_t handler;
802 struct queued_handler *next;
806 const struct plug_function_table *fn;
807 /* the above field _must_ be first in the structure */
817 unsigned char session_key[32];
819 int v1_remote_protoflags;
820 int v1_local_protoflags;
821 int agentfwd_enabled;
824 const struct ssh_cipher *cipher;
827 const struct ssh2_cipher *cscipher, *sccipher;
828 void *cs_cipher_ctx, *sc_cipher_ctx;
829 const struct ssh_mac *csmac, *scmac;
830 void *cs_mac_ctx, *sc_mac_ctx;
831 const struct ssh_compress *cscomp, *sccomp;
832 void *cs_comp_ctx, *sc_comp_ctx;
833 const struct ssh_kex *kex;
834 const struct ssh_signkey *hostkey;
835 char *hostkey_str; /* string representation, for easy checking in rekeys */
836 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
837 int v2_session_id_len;
843 int echoing, editing;
847 int ospeed, ispeed; /* temporaries */
848 int term_width, term_height;
850 tree234 *channels; /* indexed by local id */
851 struct ssh_channel *mainchan; /* primary session channel */
852 int ncmode; /* is primary channel direct-tcpip? */
857 tree234 *rportfwds, *portfwds;
861 SSH_STATE_BEFORE_SIZE,
867 int size_needed, eof_needed;
868 int sent_console_eof;
869 int got_pty; /* affects EOF behaviour on main channel */
871 struct Packet **queue;
872 int queuelen, queuesize;
874 unsigned char *deferred_send_data;
875 int deferred_len, deferred_size;
878 * Gross hack: pscp will try to start SFTP but fall back to
879 * scp1 if that fails. This variable is the means by which
880 * scp.c can reach into the SSH code and find out which one it
885 bufchain banner; /* accumulates banners during do_ssh2_authconn */
890 struct X11Display *x11disp;
893 int conn_throttle_count;
896 int v1_stdout_throttling;
897 unsigned long v2_outgoing_sequence;
899 int ssh1_rdpkt_crstate;
900 int ssh2_rdpkt_crstate;
901 int ssh_gotdata_crstate;
902 int do_ssh1_connection_crstate;
904 void *do_ssh_init_state;
905 void *do_ssh1_login_state;
906 void *do_ssh2_transport_state;
907 void *do_ssh2_authconn_state;
909 struct rdpkt1_state_tag rdpkt1_state;
910 struct rdpkt2_state_tag rdpkt2_state;
912 /* SSH-1 and SSH-2 use this for different things, but both use it */
913 int protocol_initial_phase_done;
915 void (*protocol) (Ssh ssh, void *vin, int inlen,
917 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
920 * We maintain our own copy of a Conf structure here. That way,
921 * when we're passed a new one for reconfiguration, we can check
922 * the differences and potentially reconfigure port forwardings
923 * etc in mid-session.
928 * Values cached out of conf so as to avoid the tree234 lookup
929 * cost every time they're used.
934 * Dynamically allocated username string created during SSH
935 * login. Stored in here rather than in the coroutine state so
936 * that it'll be reliably freed if we shut down the SSH session
937 * at some unexpected moment.
942 * Used to transfer data back from async callbacks.
944 void *agent_response;
945 int agent_response_len;
949 * The SSH connection can be set as `frozen', meaning we are
950 * not currently accepting incoming data from the network. This
951 * is slightly more serious than setting the _socket_ as
952 * frozen, because we may already have had data passed to us
953 * from the network which we need to delay processing until
954 * after the freeze is lifted, so we also need a bufchain to
958 bufchain queued_incoming_data;
961 * Dispatch table for packet types that we may have to deal
964 handler_fn_t packet_dispatch[256];
967 * Queues of one-off handler functions for success/failure
968 * indications from a request.
970 struct queued_handler *qhead, *qtail;
971 handler_fn_t q_saved_handler1, q_saved_handler2;
974 * This module deals with sending keepalives.
979 * Track incoming and outgoing data sizes and time, for
982 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
983 unsigned long max_data_size;
985 unsigned long next_rekey, last_rekey;
986 char *deferred_rekey_reason; /* points to STATIC string; don't free */
989 * Fully qualified host name, which we need if doing GSSAPI.
995 * GSSAPI libraries for this session.
997 struct ssh_gss_liblist *gsslibs;
1001 #define logevent(s) logevent(ssh->frontend, s)
1003 /* logevent, only printf-formatted. */
1004 static void logeventf(Ssh ssh, const char *fmt, ...)
1010 buf = dupvprintf(fmt, ap);
1016 static void bomb_out(Ssh ssh, char *text)
1018 ssh_do_close(ssh, FALSE);
1020 connection_fatal(ssh->frontend, "%s", text);
1024 #define bombout(msg) bomb_out(ssh, dupprintf msg)
1026 /* Functions to leave bits out of the SSH packet log file. */
1028 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
1030 if (conf_get_int(ssh->conf, CONF_logomitpass))
1031 pkt->logmode = blanktype;
1034 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
1036 if (ssh->logomitdata)
1037 pkt->logmode = blanktype;
1040 static void end_log_omission(Ssh ssh, struct Packet *pkt)
1042 pkt->logmode = PKTLOG_EMIT;
1045 /* Helper function for common bits of parsing ttymodes. */
1046 static void parse_ttymodes(Ssh ssh,
1047 void (*do_mode)(void *data, char *mode, char *val),
1052 for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key);
1054 val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) {
1056 * val[0] is either 'V', indicating that an explicit value
1057 * follows it, or 'A' indicating that we should pass the
1058 * value through from the local environment via get_ttymode.
1060 if (val[0] == 'A') {
1061 val = get_ttymode(ssh->frontend, key);
1063 do_mode(data, key, val);
1067 do_mode(data, key, val + 1); /* skip the 'V' */
1071 static int ssh_channelcmp(void *av, void *bv)
1073 struct ssh_channel *a = (struct ssh_channel *) av;
1074 struct ssh_channel *b = (struct ssh_channel *) bv;
1075 if (a->localid < b->localid)
1077 if (a->localid > b->localid)
1081 static int ssh_channelfind(void *av, void *bv)
1083 unsigned *a = (unsigned *) av;
1084 struct ssh_channel *b = (struct ssh_channel *) bv;
1085 if (*a < b->localid)
1087 if (*a > b->localid)
1092 static int ssh_rportcmp_ssh1(void *av, void *bv)
1094 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1095 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1097 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
1098 return i < 0 ? -1 : +1;
1099 if (a->dport > b->dport)
1101 if (a->dport < b->dport)
1106 static int ssh_rportcmp_ssh2(void *av, void *bv)
1108 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
1109 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
1111 if (a->sport > b->sport)
1113 if (a->sport < b->sport)
1119 * Special form of strcmp which can cope with NULL inputs. NULL is
1120 * defined to sort before even the empty string.
1122 static int nullstrcmp(const char *a, const char *b)
1124 if (a == NULL && b == NULL)
1130 return strcmp(a, b);
1133 static int ssh_portcmp(void *av, void *bv)
1135 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1136 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1138 if (a->type > b->type)
1140 if (a->type < b->type)
1142 if (a->addressfamily > b->addressfamily)
1144 if (a->addressfamily < b->addressfamily)
1146 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1147 return i < 0 ? -1 : +1;
1148 if (a->sport > b->sport)
1150 if (a->sport < b->sport)
1152 if (a->type != 'D') {
1153 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1154 return i < 0 ? -1 : +1;
1155 if (a->dport > b->dport)
1157 if (a->dport < b->dport)
1163 static int alloc_channel_id(Ssh ssh)
1165 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1166 unsigned low, high, mid;
1168 struct ssh_channel *c;
1171 * First-fit allocation of channel numbers: always pick the
1172 * lowest unused one. To do this, binary-search using the
1173 * counted B-tree to find the largest channel ID which is in a
1174 * contiguous sequence from the beginning. (Precisely
1175 * everything in that sequence must have ID equal to its tree
1176 * index plus CHANNEL_NUMBER_OFFSET.)
1178 tsize = count234(ssh->channels);
1182 while (high - low > 1) {
1183 mid = (high + low) / 2;
1184 c = index234(ssh->channels, mid);
1185 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1186 low = mid; /* this one is fine */
1188 high = mid; /* this one is past it */
1191 * Now low points to either -1, or the tree index of the
1192 * largest ID in the initial sequence.
1195 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1196 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1198 return low + 1 + CHANNEL_NUMBER_OFFSET;
1201 static void c_write_stderr(int trusted, const char *buf, int len)
1204 for (i = 0; i < len; i++)
1205 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1206 fputc(buf[i], stderr);
1209 static void c_write(Ssh ssh, const char *buf, int len)
1211 if (flags & FLAG_STDERR)
1212 c_write_stderr(1, buf, len);
1214 from_backend(ssh->frontend, 1, buf, len);
1217 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1219 if (flags & FLAG_STDERR)
1220 c_write_stderr(0, buf, len);
1222 from_backend_untrusted(ssh->frontend, buf, len);
1225 static void c_write_str(Ssh ssh, const char *buf)
1227 c_write(ssh, buf, strlen(buf));
1230 static void ssh_free_packet(struct Packet *pkt)
1235 static struct Packet *ssh_new_packet(void)
1237 struct Packet *pkt = snew(struct Packet);
1239 pkt->body = pkt->data = NULL;
1241 pkt->logmode = PKTLOG_EMIT;
1249 * Collect incoming data in the incoming packet buffer.
1250 * Decipher and verify the packet when it is completely read.
1251 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1252 * Update the *data and *datalen variables.
1253 * Return a Packet structure when a packet is completed.
1255 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1257 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1259 crBegin(ssh->ssh1_rdpkt_crstate);
1261 st->pktin = ssh_new_packet();
1263 st->pktin->type = 0;
1264 st->pktin->length = 0;
1266 for (st->i = st->len = 0; st->i < 4; st->i++) {
1267 while ((*datalen) == 0)
1269 st->len = (st->len << 8) + **data;
1270 (*data)++, (*datalen)--;
1273 st->pad = 8 - (st->len % 8);
1274 st->biglen = st->len + st->pad;
1275 st->pktin->length = st->len - 5;
1277 if (st->biglen < 0) {
1278 bombout(("Extremely large packet length from server suggests"
1279 " data stream corruption"));
1280 ssh_free_packet(st->pktin);
1284 st->pktin->maxlen = st->biglen;
1285 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1287 st->to_read = st->biglen;
1288 st->p = st->pktin->data;
1289 while (st->to_read > 0) {
1290 st->chunk = st->to_read;
1291 while ((*datalen) == 0)
1293 if (st->chunk > (*datalen))
1294 st->chunk = (*datalen);
1295 memcpy(st->p, *data, st->chunk);
1297 *datalen -= st->chunk;
1299 st->to_read -= st->chunk;
1302 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1303 st->biglen, NULL)) {
1304 bombout(("Network attack (CRC compensation) detected!"));
1305 ssh_free_packet(st->pktin);
1310 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1312 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1313 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1314 if (st->gotcrc != st->realcrc) {
1315 bombout(("Incorrect CRC received on packet"));
1316 ssh_free_packet(st->pktin);
1320 st->pktin->body = st->pktin->data + st->pad + 1;
1321 st->pktin->savedpos = 0;
1323 if (ssh->v1_compressing) {
1324 unsigned char *decompblk;
1326 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1327 st->pktin->body - 1, st->pktin->length + 1,
1328 &decompblk, &decomplen)) {
1329 bombout(("Zlib decompression encountered invalid data"));
1330 ssh_free_packet(st->pktin);
1334 if (st->pktin->maxlen < st->pad + decomplen) {
1335 st->pktin->maxlen = st->pad + decomplen;
1336 st->pktin->data = sresize(st->pktin->data,
1337 st->pktin->maxlen + APIEXTRA,
1339 st->pktin->body = st->pktin->data + st->pad + 1;
1342 memcpy(st->pktin->body - 1, decompblk, decomplen);
1344 st->pktin->length = decomplen - 1;
1347 st->pktin->type = st->pktin->body[-1];
1350 * Log incoming packet, possibly omitting sensitive fields.
1354 struct logblank_t blank;
1355 if (ssh->logomitdata) {
1356 int do_blank = FALSE, blank_prefix = 0;
1357 /* "Session data" packets - omit the data field */
1358 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1359 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1360 do_blank = TRUE; blank_prefix = 4;
1361 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1362 do_blank = TRUE; blank_prefix = 8;
1365 blank.offset = blank_prefix;
1366 blank.len = st->pktin->length;
1367 blank.type = PKTLOG_OMIT;
1371 log_packet(ssh->logctx,
1372 PKT_INCOMING, st->pktin->type,
1373 ssh1_pkt_type(st->pktin->type),
1374 st->pktin->body, st->pktin->length,
1375 nblanks, &blank, NULL);
1378 crFinish(st->pktin);
1381 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1383 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1385 crBegin(ssh->ssh2_rdpkt_crstate);
1387 st->pktin = ssh_new_packet();
1389 st->pktin->type = 0;
1390 st->pktin->length = 0;
1392 st->cipherblk = ssh->sccipher->blksize;
1395 if (st->cipherblk < 8)
1397 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1399 if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) &&
1402 * When dealing with a CBC-mode cipher, we want to avoid the
1403 * possibility of an attacker's tweaking the ciphertext stream
1404 * so as to cause us to feed the same block to the block
1405 * cipher more than once and thus leak information
1406 * (VU#958563). The way we do this is not to take any
1407 * decisions on the basis of anything we've decrypted until
1408 * we've verified it with a MAC. That includes the packet
1409 * length, so we just read data and check the MAC repeatedly,
1410 * and when the MAC passes, see if the length we've got is
1414 /* May as well allocate the whole lot now. */
1415 st->pktin->data = snewn(OUR_V2_PACKETLIMIT + st->maclen + APIEXTRA,
1418 /* Read an amount corresponding to the MAC. */
1419 for (st->i = 0; st->i < st->maclen; st->i++) {
1420 while ((*datalen) == 0)
1422 st->pktin->data[st->i] = *(*data)++;
1428 unsigned char seq[4];
1429 ssh->scmac->start(ssh->sc_mac_ctx);
1430 PUT_32BIT(seq, st->incoming_sequence);
1431 ssh->scmac->bytes(ssh->sc_mac_ctx, seq, 4);
1434 for (;;) { /* Once around this loop per cipher block. */
1435 /* Read another cipher-block's worth, and tack it onto the end. */
1436 for (st->i = 0; st->i < st->cipherblk; st->i++) {
1437 while ((*datalen) == 0)
1439 st->pktin->data[st->packetlen+st->maclen+st->i] = *(*data)++;
1442 /* Decrypt one more block (a little further back in the stream). */
1443 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1444 st->pktin->data + st->packetlen,
1446 /* Feed that block to the MAC. */
1447 ssh->scmac->bytes(ssh->sc_mac_ctx,
1448 st->pktin->data + st->packetlen, st->cipherblk);
1449 st->packetlen += st->cipherblk;
1450 /* See if that gives us a valid packet. */
1451 if (ssh->scmac->verresult(ssh->sc_mac_ctx,
1452 st->pktin->data + st->packetlen) &&
1453 ((st->len = toint(GET_32BIT(st->pktin->data))) ==
1456 if (st->packetlen >= OUR_V2_PACKETLIMIT) {
1457 bombout(("No valid incoming packet found"));
1458 ssh_free_packet(st->pktin);
1462 st->pktin->maxlen = st->packetlen + st->maclen;
1463 st->pktin->data = sresize(st->pktin->data,
1464 st->pktin->maxlen + APIEXTRA,
1467 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1470 * Acquire and decrypt the first block of the packet. This will
1471 * contain the length and padding details.
1473 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1474 while ((*datalen) == 0)
1476 st->pktin->data[st->i] = *(*data)++;
1481 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1482 st->pktin->data, st->cipherblk);
1485 * Now get the length figure.
1487 st->len = toint(GET_32BIT(st->pktin->data));
1490 * _Completely_ silly lengths should be stomped on before they
1491 * do us any more damage.
1493 if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT ||
1494 (st->len + 4) % st->cipherblk != 0) {
1495 bombout(("Incoming packet was garbled on decryption"));
1496 ssh_free_packet(st->pktin);
1501 * So now we can work out the total packet length.
1503 st->packetlen = st->len + 4;
1506 * Allocate memory for the rest of the packet.
1508 st->pktin->maxlen = st->packetlen + st->maclen;
1509 st->pktin->data = sresize(st->pktin->data,
1510 st->pktin->maxlen + APIEXTRA,
1514 * Read and decrypt the remainder of the packet.
1516 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1518 while ((*datalen) == 0)
1520 st->pktin->data[st->i] = *(*data)++;
1523 /* Decrypt everything _except_ the MAC. */
1525 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1526 st->pktin->data + st->cipherblk,
1527 st->packetlen - st->cipherblk);
1533 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data,
1534 st->len + 4, st->incoming_sequence)) {
1535 bombout(("Incorrect MAC received on packet"));
1536 ssh_free_packet(st->pktin);
1540 /* Get and sanity-check the amount of random padding. */
1541 st->pad = st->pktin->data[4];
1542 if (st->pad < 4 || st->len - st->pad < 1) {
1543 bombout(("Invalid padding length on received packet"));
1544 ssh_free_packet(st->pktin);
1548 * This enables us to deduce the payload length.
1550 st->payload = st->len - st->pad - 1;
1552 st->pktin->length = st->payload + 5;
1553 st->pktin->encrypted_len = st->packetlen;
1555 st->pktin->sequence = st->incoming_sequence++;
1558 * Decompress packet payload.
1561 unsigned char *newpayload;
1564 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1565 st->pktin->data + 5, st->pktin->length - 5,
1566 &newpayload, &newlen)) {
1567 if (st->pktin->maxlen < newlen + 5) {
1568 st->pktin->maxlen = newlen + 5;
1569 st->pktin->data = sresize(st->pktin->data,
1570 st->pktin->maxlen + APIEXTRA,
1573 st->pktin->length = 5 + newlen;
1574 memcpy(st->pktin->data + 5, newpayload, newlen);
1579 st->pktin->savedpos = 6;
1580 st->pktin->body = st->pktin->data;
1581 st->pktin->type = st->pktin->data[5];
1584 * Log incoming packet, possibly omitting sensitive fields.
1588 struct logblank_t blank;
1589 if (ssh->logomitdata) {
1590 int do_blank = FALSE, blank_prefix = 0;
1591 /* "Session data" packets - omit the data field */
1592 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1593 do_blank = TRUE; blank_prefix = 8;
1594 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1595 do_blank = TRUE; blank_prefix = 12;
1598 blank.offset = blank_prefix;
1599 blank.len = (st->pktin->length-6) - blank_prefix;
1600 blank.type = PKTLOG_OMIT;
1604 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1605 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1607 st->pktin->data+6, st->pktin->length-6,
1608 nblanks, &blank, &st->pktin->sequence);
1611 crFinish(st->pktin);
1614 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1616 int pad, biglen, i, pktoffs;
1620 * XXX various versions of SC (including 8.8.4) screw up the
1621 * register allocation in this function and use the same register
1622 * (D6) for len and as a temporary, with predictable results. The
1623 * following sledgehammer prevents this.
1630 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1631 ssh1_pkt_type(pkt->data[12]),
1632 pkt->body, pkt->length - (pkt->body - pkt->data),
1633 pkt->nblanks, pkt->blanks, NULL);
1634 sfree(pkt->blanks); pkt->blanks = NULL;
1637 if (ssh->v1_compressing) {
1638 unsigned char *compblk;
1640 zlib_compress_block(ssh->cs_comp_ctx,
1641 pkt->data + 12, pkt->length - 12,
1642 &compblk, &complen);
1643 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1644 memcpy(pkt->data + 12, compblk, complen);
1646 pkt->length = complen + 12;
1649 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1651 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1652 pad = 8 - (len % 8);
1654 biglen = len + pad; /* len(padding+type+data+CRC) */
1656 for (i = pktoffs; i < 4+8; i++)
1657 pkt->data[i] = random_byte();
1658 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1659 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1660 PUT_32BIT(pkt->data + pktoffs, len);
1663 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1664 pkt->data + pktoffs + 4, biglen);
1666 if (offset_p) *offset_p = pktoffs;
1667 return biglen + 4; /* len(length+padding+type+data+CRC) */
1670 static int s_write(Ssh ssh, void *data, int len)
1673 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len,
1675 return sk_write(ssh->s, (char *)data, len);
1678 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1680 int len, backlog, offset;
1681 len = s_wrpkt_prepare(ssh, pkt, &offset);
1682 backlog = s_write(ssh, pkt->data + offset, len);
1683 if (backlog > SSH_MAX_BACKLOG)
1684 ssh_throttle_all(ssh, 1, backlog);
1685 ssh_free_packet(pkt);
1688 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1691 len = s_wrpkt_prepare(ssh, pkt, &offset);
1692 if (ssh->deferred_len + len > ssh->deferred_size) {
1693 ssh->deferred_size = ssh->deferred_len + len + 128;
1694 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1698 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1699 pkt->data + offset, len);
1700 ssh->deferred_len += len;
1701 ssh_free_packet(pkt);
1705 * Construct a SSH-1 packet with the specified contents.
1706 * (This all-at-once interface used to be the only one, but now SSH-1
1707 * packets can also be constructed incrementally.)
1709 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1715 pkt = ssh1_pkt_init(pkttype);
1717 while ((argtype = va_arg(ap, int)) != PKT_END) {
1718 unsigned char *argp, argchar;
1720 unsigned long argint;
1723 /* Actual fields in the packet */
1725 argint = va_arg(ap, int);
1726 ssh_pkt_adduint32(pkt, argint);
1729 argchar = (unsigned char) va_arg(ap, int);
1730 ssh_pkt_addbyte(pkt, argchar);
1733 argp = va_arg(ap, unsigned char *);
1734 arglen = va_arg(ap, int);
1735 ssh_pkt_adddata(pkt, argp, arglen);
1738 sargp = va_arg(ap, char *);
1739 ssh_pkt_addstring(pkt, sargp);
1742 bn = va_arg(ap, Bignum);
1743 ssh1_pkt_addmp(pkt, bn);
1745 /* Tokens for modifications to packet logging */
1747 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1750 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1753 end_log_omission(ssh, pkt);
1761 static void send_packet(Ssh ssh, int pkttype, ...)
1765 va_start(ap, pkttype);
1766 pkt = construct_packet(ssh, pkttype, ap);
1771 static void defer_packet(Ssh ssh, int pkttype, ...)
1775 va_start(ap, pkttype);
1776 pkt = construct_packet(ssh, pkttype, ap);
1778 s_wrpkt_defer(ssh, pkt);
1781 static int ssh_versioncmp(char *a, char *b)
1784 unsigned long av, bv;
1786 av = strtoul(a, &ae, 10);
1787 bv = strtoul(b, &be, 10);
1789 return (av < bv ? -1 : +1);
1794 av = strtoul(ae, &ae, 10);
1795 bv = strtoul(be, &be, 10);
1797 return (av < bv ? -1 : +1);
1802 * Utility routines for putting an SSH-protocol `string' and
1803 * `uint32' into a hash state.
1805 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1807 unsigned char lenblk[4];
1808 PUT_32BIT(lenblk, len);
1809 h->bytes(s, lenblk, 4);
1810 h->bytes(s, str, len);
1813 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1815 unsigned char intblk[4];
1816 PUT_32BIT(intblk, i);
1817 h->bytes(s, intblk, 4);
1821 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1823 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1825 if (pkt->maxlen < length) {
1826 unsigned char *body = pkt->body;
1827 int offset = body ? body - pkt->data : 0;
1828 pkt->maxlen = length + 256;
1829 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1830 if (body) pkt->body = pkt->data + offset;
1833 static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len)
1835 if (pkt->logmode != PKTLOG_EMIT) {
1837 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1839 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1840 (pkt->body - pkt->data);
1841 pkt->blanks[pkt->nblanks-1].len = len;
1842 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1845 ssh_pkt_ensure(pkt, pkt->length);
1846 memcpy(pkt->data + pkt->length - len, data, len);
1848 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1850 ssh_pkt_adddata(pkt, &byte, 1);
1852 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1854 ssh_pkt_adddata(pkt, &value, 1);
1856 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1859 PUT_32BIT(x, value);
1860 ssh_pkt_adddata(pkt, x, 4);
1862 static void ssh_pkt_addstring_start(struct Packet *pkt)
1864 ssh_pkt_adduint32(pkt, 0);
1865 pkt->savedpos = pkt->length;
1867 static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data)
1869 ssh_pkt_adddata(pkt, data, strlen(data));
1870 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1872 static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data,
1875 ssh_pkt_adddata(pkt, data, len);
1876 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1878 static void ssh_pkt_addstring(struct Packet *pkt, const char *data)
1880 ssh_pkt_addstring_start(pkt);
1881 ssh_pkt_addstring_str(pkt, data);
1883 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1885 int len = ssh1_bignum_length(b);
1886 unsigned char *data = snewn(len, unsigned char);
1887 (void) ssh1_write_bignum(data, b);
1888 ssh_pkt_adddata(pkt, data, len);
1891 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1894 int i, n = (bignum_bitcount(b) + 7) / 8;
1895 p = snewn(n + 1, unsigned char);
1897 for (i = 1; i <= n; i++)
1898 p[i] = bignum_byte(b, n - i);
1900 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1902 memmove(p, p + i, n + 1 - i);
1906 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1910 p = ssh2_mpint_fmt(b, &len);
1911 ssh_pkt_addstring_start(pkt);
1912 ssh_pkt_addstring_data(pkt, (char *)p, len);
1916 static struct Packet *ssh1_pkt_init(int pkt_type)
1918 struct Packet *pkt = ssh_new_packet();
1919 pkt->length = 4 + 8; /* space for length + max padding */
1920 ssh_pkt_addbyte(pkt, pkt_type);
1921 pkt->body = pkt->data + pkt->length;
1925 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1926 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1927 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1928 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1929 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1930 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1931 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1932 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1933 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1935 static struct Packet *ssh2_pkt_init(int pkt_type)
1937 struct Packet *pkt = ssh_new_packet();
1938 pkt->length = 5; /* space for packet length + padding length */
1940 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1941 pkt->body = pkt->data + pkt->length; /* after packet type */
1946 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1947 * put the MAC on it. Final packet, ready to be sent, is stored in
1948 * pkt->data. Total length is returned.
1950 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1952 int cipherblk, maclen, padding, i;
1955 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1956 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1957 pkt->body, pkt->length - (pkt->body - pkt->data),
1958 pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence);
1959 sfree(pkt->blanks); pkt->blanks = NULL;
1963 * Compress packet payload.
1966 unsigned char *newpayload;
1969 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1971 &newpayload, &newlen)) {
1973 ssh2_pkt_adddata(pkt, newpayload, newlen);
1979 * Add padding. At least four bytes, and must also bring total
1980 * length (minus MAC) up to a multiple of the block size.
1981 * If pkt->forcepad is set, make sure the packet is at least that size
1984 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1985 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1987 if (pkt->length + padding < pkt->forcepad)
1988 padding = pkt->forcepad - pkt->length;
1990 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1991 assert(padding <= 255);
1992 maclen = ssh->csmac ? ssh->csmac->len : 0;
1993 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1994 pkt->data[4] = padding;
1995 for (i = 0; i < padding; i++)
1996 pkt->data[pkt->length + i] = random_byte();
1997 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1999 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
2000 pkt->length + padding,
2001 ssh->v2_outgoing_sequence);
2002 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
2005 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
2006 pkt->data, pkt->length + padding);
2008 pkt->encrypted_len = pkt->length + padding;
2010 /* Ready-to-send packet starts at pkt->data. We return length. */
2011 return pkt->length + padding + maclen;
2015 * Routines called from the main SSH code to send packets. There
2016 * are quite a few of these, because we have two separate
2017 * mechanisms for delaying the sending of packets:
2019 * - In order to send an IGNORE message and a password message in
2020 * a single fixed-length blob, we require the ability to
2021 * concatenate the encrypted forms of those two packets _into_ a
2022 * single blob and then pass it to our <network.h> transport
2023 * layer in one go. Hence, there's a deferment mechanism which
2024 * works after packet encryption.
2026 * - In order to avoid sending any connection-layer messages
2027 * during repeat key exchange, we have to queue up any such
2028 * outgoing messages _before_ they are encrypted (and in
2029 * particular before they're allocated sequence numbers), and
2030 * then send them once we've finished.
2032 * I call these mechanisms `defer' and `queue' respectively, so as
2033 * to distinguish them reasonably easily.
2035 * The functions send_noqueue() and defer_noqueue() free the packet
2036 * structure they are passed. Every outgoing packet goes through
2037 * precisely one of these functions in its life; packets passed to
2038 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2039 * these or get queued, and then when the queue is later emptied
2040 * the packets are all passed to defer_noqueue().
2042 * When using a CBC-mode cipher, it's necessary to ensure that an
2043 * attacker can't provide data to be encrypted using an IV that they
2044 * know. We ensure this by prefixing each packet that might contain
2045 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2046 * mechanism, so in this case send_noqueue() ends up redirecting to
2047 * defer_noqueue(). If you don't like this inefficiency, don't use
2051 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
2052 static void ssh_pkt_defersend(Ssh);
2055 * Send an SSH-2 packet immediately, without queuing or deferring.
2057 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
2061 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
2062 /* We need to send two packets, so use the deferral mechanism. */
2063 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2064 ssh_pkt_defersend(ssh);
2067 len = ssh2_pkt_construct(ssh, pkt);
2068 backlog = s_write(ssh, pkt->data, len);
2069 if (backlog > SSH_MAX_BACKLOG)
2070 ssh_throttle_all(ssh, 1, backlog);
2072 ssh->outgoing_data_size += pkt->encrypted_len;
2073 if (!ssh->kex_in_progress &&
2074 ssh->max_data_size != 0 &&
2075 ssh->outgoing_data_size > ssh->max_data_size)
2076 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2078 ssh_free_packet(pkt);
2082 * Defer an SSH-2 packet.
2084 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
2087 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
2088 ssh->deferred_len == 0 && !noignore &&
2089 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2091 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2092 * get encrypted with a known IV.
2094 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2095 ssh2_pkt_addstring_start(ipkt);
2096 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
2098 len = ssh2_pkt_construct(ssh, pkt);
2099 if (ssh->deferred_len + len > ssh->deferred_size) {
2100 ssh->deferred_size = ssh->deferred_len + len + 128;
2101 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
2105 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
2106 ssh->deferred_len += len;
2107 ssh->deferred_data_size += pkt->encrypted_len;
2108 ssh_free_packet(pkt);
2112 * Queue an SSH-2 packet.
2114 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
2116 assert(ssh->queueing);
2118 if (ssh->queuelen >= ssh->queuesize) {
2119 ssh->queuesize = ssh->queuelen + 32;
2120 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
2123 ssh->queue[ssh->queuelen++] = pkt;
2127 * Either queue or send a packet, depending on whether queueing is
2130 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
2133 ssh2_pkt_queue(ssh, pkt);
2135 ssh2_pkt_send_noqueue(ssh, pkt);
2139 * Either queue or defer a packet, depending on whether queueing is
2142 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
2145 ssh2_pkt_queue(ssh, pkt);
2147 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
2151 * Send the whole deferred data block constructed by
2152 * ssh2_pkt_defer() or SSH-1's defer_packet().
2154 * The expected use of the defer mechanism is that you call
2155 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2156 * not currently queueing, this simply sets up deferred_send_data
2157 * and then sends it. If we _are_ currently queueing, the calls to
2158 * ssh2_pkt_defer() put the deferred packets on to the queue
2159 * instead, and therefore ssh_pkt_defersend() has no deferred data
2160 * to send. Hence, there's no need to make it conditional on
2163 static void ssh_pkt_defersend(Ssh ssh)
2166 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
2167 ssh->deferred_len = ssh->deferred_size = 0;
2168 sfree(ssh->deferred_send_data);
2169 ssh->deferred_send_data = NULL;
2170 if (backlog > SSH_MAX_BACKLOG)
2171 ssh_throttle_all(ssh, 1, backlog);
2173 ssh->outgoing_data_size += ssh->deferred_data_size;
2174 if (!ssh->kex_in_progress &&
2175 ssh->max_data_size != 0 &&
2176 ssh->outgoing_data_size > ssh->max_data_size)
2177 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
2178 ssh->deferred_data_size = 0;
2182 * Send a packet whose length needs to be disguised (typically
2183 * passwords or keyboard-interactive responses).
2185 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
2191 * The simplest way to do this is to adjust the
2192 * variable-length padding field in the outgoing packet.
2194 * Currently compiled out, because some Cisco SSH servers
2195 * don't like excessively padded packets (bah, why's it
2198 pkt->forcepad = padsize;
2199 ssh2_pkt_send(ssh, pkt);
2204 * If we can't do that, however, an alternative approach is
2205 * to use the pkt_defer mechanism to bundle the packet
2206 * tightly together with an SSH_MSG_IGNORE such that their
2207 * combined length is a constant. So first we construct the
2208 * final form of this packet and defer its sending.
2210 ssh2_pkt_defer(ssh, pkt);
2213 * Now construct an SSH_MSG_IGNORE which includes a string
2214 * that's an exact multiple of the cipher block size. (If
2215 * the cipher is NULL so that the block size is
2216 * unavailable, we don't do this trick at all, because we
2217 * gain nothing by it.)
2219 if (ssh->cscipher &&
2220 !(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
2223 stringlen = (256 - ssh->deferred_len);
2224 stringlen += ssh->cscipher->blksize - 1;
2225 stringlen -= (stringlen % ssh->cscipher->blksize);
2228 * Temporarily disable actual compression, so we
2229 * can guarantee to get this string exactly the
2230 * length we want it. The compression-disabling
2231 * routine should return an integer indicating how
2232 * many bytes we should adjust our string length
2236 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2238 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2239 ssh2_pkt_addstring_start(pkt);
2240 for (i = 0; i < stringlen; i++) {
2241 char c = (char) random_byte();
2242 ssh2_pkt_addstring_data(pkt, &c, 1);
2244 ssh2_pkt_defer(ssh, pkt);
2246 ssh_pkt_defersend(ssh);
2251 * Send all queued SSH-2 packets. We send them by means of
2252 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2253 * packets that needed to be lumped together.
2255 static void ssh2_pkt_queuesend(Ssh ssh)
2259 assert(!ssh->queueing);
2261 for (i = 0; i < ssh->queuelen; i++)
2262 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2265 ssh_pkt_defersend(ssh);
2269 void bndebug(char *string, Bignum b)
2273 p = ssh2_mpint_fmt(b, &len);
2274 debug(("%s", string));
2275 for (i = 0; i < len; i++)
2276 debug((" %02x", p[i]));
2282 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2286 p = ssh2_mpint_fmt(b, &len);
2287 hash_string(h, s, p, len);
2292 * Packet decode functions for both SSH-1 and SSH-2.
2294 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2296 unsigned long value;
2297 if (pkt->length - pkt->savedpos < 4)
2298 return 0; /* arrgh, no way to decline (FIXME?) */
2299 value = GET_32BIT(pkt->body + pkt->savedpos);
2303 static int ssh2_pkt_getbool(struct Packet *pkt)
2305 unsigned long value;
2306 if (pkt->length - pkt->savedpos < 1)
2307 return 0; /* arrgh, no way to decline (FIXME?) */
2308 value = pkt->body[pkt->savedpos] != 0;
2312 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2317 if (pkt->length - pkt->savedpos < 4)
2319 len = toint(GET_32BIT(pkt->body + pkt->savedpos));
2324 if (pkt->length - pkt->savedpos < *length)
2326 *p = (char *)(pkt->body + pkt->savedpos);
2327 pkt->savedpos += *length;
2329 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2331 if (pkt->length - pkt->savedpos < length)
2333 pkt->savedpos += length;
2334 return pkt->body + (pkt->savedpos - length);
2336 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2337 unsigned char **keystr)
2341 j = makekey(pkt->body + pkt->savedpos,
2342 pkt->length - pkt->savedpos,
2349 assert(pkt->savedpos < pkt->length);
2353 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2358 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2359 pkt->length - pkt->savedpos, &b);
2367 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2373 ssh_pkt_getstring(pkt, &p, &length);
2378 b = bignum_from_bytes((unsigned char *)p, length);
2383 * Helper function to add an SSH-2 signature blob to a packet.
2384 * Expects to be shown the public key blob as well as the signature
2385 * blob. Normally works just like ssh2_pkt_addstring, but will
2386 * fiddle with the signature packet if necessary for
2387 * BUG_SSH2_RSA_PADDING.
2389 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2390 void *pkblob_v, int pkblob_len,
2391 void *sigblob_v, int sigblob_len)
2393 unsigned char *pkblob = (unsigned char *)pkblob_v;
2394 unsigned char *sigblob = (unsigned char *)sigblob_v;
2396 /* dmemdump(pkblob, pkblob_len); */
2397 /* dmemdump(sigblob, sigblob_len); */
2400 * See if this is in fact an ssh-rsa signature and a buggy
2401 * server; otherwise we can just do this the easy way.
2403 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 &&
2404 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2405 int pos, len, siglen;
2408 * Find the byte length of the modulus.
2411 pos = 4+7; /* skip over "ssh-rsa" */
2412 len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */
2413 if (len < 0 || len > pkblob_len - pos - 4)
2415 pos += 4 + len; /* skip over exponent */
2416 if (pkblob_len - pos < 4)
2418 len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */
2419 if (len < 0 || len > pkblob_len - pos - 4)
2421 pos += 4; /* find modulus itself */
2422 while (len > 0 && pkblob[pos] == 0)
2424 /* debug(("modulus length is %d\n", len)); */
2427 * Now find the signature integer.
2429 pos = 4+7; /* skip over "ssh-rsa" */
2430 if (sigblob_len < pos+4)
2432 siglen = toint(GET_32BIT(sigblob+pos));
2433 if (siglen != sigblob_len - pos - 4)
2435 /* debug(("signature length is %d\n", siglen)); */
2437 if (len != siglen) {
2438 unsigned char newlen[4];
2439 ssh2_pkt_addstring_start(pkt);
2440 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2441 /* dmemdump(sigblob, pos); */
2442 pos += 4; /* point to start of actual sig */
2443 PUT_32BIT(newlen, len);
2444 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2445 /* dmemdump(newlen, 4); */
2447 while (len-- > siglen) {
2448 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2449 /* dmemdump(newlen, 1); */
2451 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2452 /* dmemdump(sigblob+pos, siglen); */
2456 /* Otherwise fall through and do it the easy way. We also come
2457 * here as a fallback if we discover above that the key blob
2458 * is misformatted in some way. */
2462 ssh2_pkt_addstring_start(pkt);
2463 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2467 * Examine the remote side's version string and compare it against
2468 * a list of known buggy implementations.
2470 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2472 char *imp; /* pointer to implementation part */
2474 imp += strcspn(imp, "-");
2476 imp += strcspn(imp, "-");
2479 ssh->remote_bugs = 0;
2482 * General notes on server version strings:
2483 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2484 * here -- in particular, we've heard of one that's perfectly happy
2485 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2486 * so we can't distinguish them.
2488 if (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == FORCE_ON ||
2489 (conf_get_int(ssh->conf, CONF_sshbug_ignore1) == AUTO &&
2490 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2491 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2492 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2493 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2495 * These versions don't support SSH1_MSG_IGNORE, so we have
2496 * to use a different defence against password length
2499 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2500 logevent("We believe remote version has SSH-1 ignore bug");
2503 if (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == FORCE_ON ||
2504 (conf_get_int(ssh->conf, CONF_sshbug_plainpw1) == AUTO &&
2505 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2507 * These versions need a plain password sent; they can't
2508 * handle having a null and a random length of data after
2511 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2512 logevent("We believe remote version needs a plain SSH-1 password");
2515 if (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == FORCE_ON ||
2516 (conf_get_int(ssh->conf, CONF_sshbug_rsa1) == AUTO &&
2517 (!strcmp(imp, "Cisco-1.25")))) {
2519 * These versions apparently have no clue whatever about
2520 * RSA authentication and will panic and die if they see
2521 * an AUTH_RSA message.
2523 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2524 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2527 if (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == FORCE_ON ||
2528 (conf_get_int(ssh->conf, CONF_sshbug_hmac2) == AUTO &&
2529 !wc_match("* VShell", imp) &&
2530 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2531 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2532 wc_match("2.1 *", imp)))) {
2534 * These versions have the HMAC bug.
2536 ssh->remote_bugs |= BUG_SSH2_HMAC;
2537 logevent("We believe remote version has SSH-2 HMAC bug");
2540 if (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == FORCE_ON ||
2541 (conf_get_int(ssh->conf, CONF_sshbug_derivekey2) == AUTO &&
2542 !wc_match("* VShell", imp) &&
2543 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2545 * These versions have the key-derivation bug (failing to
2546 * include the literal shared secret in the hashes that
2547 * generate the keys).
2549 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2550 logevent("We believe remote version has SSH-2 key-derivation bug");
2553 if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON ||
2554 (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO &&
2555 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2556 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2558 * These versions have the SSH-2 RSA padding bug.
2560 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2561 logevent("We believe remote version has SSH-2 RSA padding bug");
2564 if (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == FORCE_ON ||
2565 (conf_get_int(ssh->conf, CONF_sshbug_pksessid2) == AUTO &&
2566 wc_match("OpenSSH_2.[0-2]*", imp))) {
2568 * These versions have the SSH-2 session-ID bug in
2569 * public-key authentication.
2571 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2572 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2575 if (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == FORCE_ON ||
2576 (conf_get_int(ssh->conf, CONF_sshbug_rekey2) == AUTO &&
2577 (wc_match("DigiSSH_2.0", imp) ||
2578 wc_match("OpenSSH_2.[0-4]*", imp) ||
2579 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2580 wc_match("Sun_SSH_1.0", imp) ||
2581 wc_match("Sun_SSH_1.0.1", imp) ||
2582 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2583 wc_match("WeOnlyDo-*", imp)))) {
2585 * These versions have the SSH-2 rekey bug.
2587 ssh->remote_bugs |= BUG_SSH2_REKEY;
2588 logevent("We believe remote version has SSH-2 rekey bug");
2591 if (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == FORCE_ON ||
2592 (conf_get_int(ssh->conf, CONF_sshbug_maxpkt2) == AUTO &&
2593 (wc_match("1.36_sshlib GlobalSCAPE", imp) ||
2594 wc_match("1.36 sshlib: GlobalScape", imp)))) {
2596 * This version ignores our makpkt and needs to be throttled.
2598 ssh->remote_bugs |= BUG_SSH2_MAXPKT;
2599 logevent("We believe remote version ignores SSH-2 maximum packet size");
2602 if (conf_get_int(ssh->conf, CONF_sshbug_ignore2) == FORCE_ON) {
2604 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2605 * none detected automatically.
2607 ssh->remote_bugs |= BUG_CHOKES_ON_SSH2_IGNORE;
2608 logevent("We believe remote version has SSH-2 ignore bug");
2611 if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) {
2613 * Servers that don't support our winadj request for one
2614 * reason or another. Currently, none detected automatically.
2616 ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ;
2617 logevent("We believe remote version has winadj bug");
2622 * The `software version' part of an SSH version string is required
2623 * to contain no spaces or minus signs.
2625 static void ssh_fix_verstring(char *str)
2627 /* Eat "SSH-<protoversion>-". */
2628 assert(*str == 'S'); str++;
2629 assert(*str == 'S'); str++;
2630 assert(*str == 'H'); str++;
2631 assert(*str == '-'); str++;
2632 while (*str && *str != '-') str++;
2633 assert(*str == '-'); str++;
2635 /* Convert minus signs and spaces in the remaining string into
2638 if (*str == '-' || *str == ' ')
2645 * Send an appropriate SSH version string.
2647 static void ssh_send_verstring(Ssh ssh, char *svers)
2651 if (ssh->version == 2) {
2653 * Construct a v2 version string.
2655 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2658 * Construct a v1 version string.
2660 verstring = dupprintf("SSH-%s-%s\012",
2661 (ssh_versioncmp(svers, "1.5") <= 0 ?
2666 ssh_fix_verstring(verstring);
2668 if (ssh->version == 2) {
2671 * Record our version string.
2673 len = strcspn(verstring, "\015\012");
2674 ssh->v_c = snewn(len + 1, char);
2675 memcpy(ssh->v_c, verstring, len);
2679 logeventf(ssh, "We claim version: %.*s",
2680 strcspn(verstring, "\015\012"), verstring);
2681 s_write(ssh, verstring, strlen(verstring));
2685 static int do_ssh_init(Ssh ssh, unsigned char c)
2687 struct do_ssh_init_state {
2696 crState(do_ssh_init_state);
2700 /* Search for a line beginning with the string "SSH-" in the input. */
2702 if (c != 'S') goto no;
2704 if (c != 'S') goto no;
2706 if (c != 'H') goto no;
2708 if (c != '-') goto no;
2717 s->vstring = snewn(s->vstrsize, char);
2718 strcpy(s->vstring, "SSH-");
2722 crReturn(1); /* get another char */
2723 if (s->vslen >= s->vstrsize - 1) {
2725 s->vstring = sresize(s->vstring, s->vstrsize, char);
2727 s->vstring[s->vslen++] = c;
2730 s->version[s->i] = '\0';
2732 } else if (s->i < sizeof(s->version) - 1)
2733 s->version[s->i++] = c;
2734 } else if (c == '\012')
2738 ssh->agentfwd_enabled = FALSE;
2739 ssh->rdpkt2_state.incoming_sequence = 0;
2741 s->vstring[s->vslen] = 0;
2742 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2743 logeventf(ssh, "Server version: %s", s->vstring);
2744 ssh_detect_bugs(ssh, s->vstring);
2747 * Decide which SSH protocol version to support.
2750 /* Anything strictly below "2.0" means protocol 1 is supported. */
2751 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2752 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2753 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2755 if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) {
2756 bombout(("SSH protocol version 1 required by user but not provided by server"));
2759 if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) {
2760 bombout(("SSH protocol version 2 required by user but not provided by server"));
2764 if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1))
2769 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2771 /* Send the version string, if we haven't already */
2772 if (conf_get_int(ssh->conf, CONF_sshprot) != 3)
2773 ssh_send_verstring(ssh, s->version);
2775 if (ssh->version == 2) {
2778 * Record their version string.
2780 len = strcspn(s->vstring, "\015\012");
2781 ssh->v_s = snewn(len + 1, char);
2782 memcpy(ssh->v_s, s->vstring, len);
2786 * Initialise SSH-2 protocol.
2788 ssh->protocol = ssh2_protocol;
2789 ssh2_protocol_setup(ssh);
2790 ssh->s_rdpkt = ssh2_rdpkt;
2793 * Initialise SSH-1 protocol.
2795 ssh->protocol = ssh1_protocol;
2796 ssh1_protocol_setup(ssh);
2797 ssh->s_rdpkt = ssh1_rdpkt;
2799 if (ssh->version == 2)
2800 do_ssh2_transport(ssh, NULL, -1, NULL);
2802 update_specials_menu(ssh->frontend);
2803 ssh->state = SSH_STATE_BEFORE_SIZE;
2804 ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh);
2811 static void ssh_process_incoming_data(Ssh ssh,
2812 unsigned char **data, int *datalen)
2814 struct Packet *pktin;
2816 pktin = ssh->s_rdpkt(ssh, data, datalen);
2818 ssh->protocol(ssh, NULL, 0, pktin);
2819 ssh_free_packet(pktin);
2823 static void ssh_queue_incoming_data(Ssh ssh,
2824 unsigned char **data, int *datalen)
2826 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2831 static void ssh_process_queued_incoming_data(Ssh ssh)
2834 unsigned char *data;
2837 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2838 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2842 while (!ssh->frozen && len > 0)
2843 ssh_process_incoming_data(ssh, &data, &len);
2846 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2850 static void ssh_set_frozen(Ssh ssh, int frozen)
2853 sk_set_frozen(ssh->s, frozen);
2854 ssh->frozen = frozen;
2857 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2859 /* Log raw data, if we're in that mode. */
2861 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2864 crBegin(ssh->ssh_gotdata_crstate);
2867 * To begin with, feed the characters one by one to the
2868 * protocol initialisation / selection function do_ssh_init().
2869 * When that returns 0, we're done with the initial greeting
2870 * exchange and can move on to packet discipline.
2873 int ret; /* need not be kept across crReturn */
2875 crReturnV; /* more data please */
2876 ret = do_ssh_init(ssh, *data);
2884 * We emerge from that loop when the initial negotiation is
2885 * over and we have selected an s_rdpkt function. Now pass
2886 * everything to s_rdpkt, and then pass the resulting packets
2887 * to the proper protocol handler.
2891 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2893 ssh_queue_incoming_data(ssh, &data, &datalen);
2894 /* This uses up all data and cannot cause anything interesting
2895 * to happen; indeed, for anything to happen at all, we must
2896 * return, so break out. */
2898 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2899 /* This uses up some or all data, and may freeze the
2901 ssh_process_queued_incoming_data(ssh);
2903 /* This uses up some or all data, and may freeze the
2905 ssh_process_incoming_data(ssh, &data, &datalen);
2907 /* FIXME this is probably EBW. */
2908 if (ssh->state == SSH_STATE_CLOSED)
2911 /* We're out of data. Go and get some more. */
2917 static int ssh_do_close(Ssh ssh, int notify_exit)
2920 struct ssh_channel *c;
2922 ssh->state = SSH_STATE_CLOSED;
2923 expire_timer_context(ssh);
2928 notify_remote_exit(ssh->frontend);
2933 * Now we must shut down any port- and X-forwarded channels going
2934 * through this connection.
2936 if (ssh->channels) {
2937 while (NULL != (c = index234(ssh->channels, 0))) {
2940 x11_close(c->u.x11.s);
2943 case CHAN_SOCKDATA_DORMANT:
2944 pfd_close(c->u.pfd.s);
2947 del234(ssh->channels, c); /* moving next one to index 0 */
2948 if (ssh->version == 2)
2949 bufchain_clear(&c->v.v2.outbuffer);
2954 * Go through port-forwardings, and close any associated
2955 * listening sockets.
2957 if (ssh->portfwds) {
2958 struct ssh_portfwd *pf;
2959 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2960 /* Dispose of any listening socket. */
2962 pfd_terminate(pf->local);
2963 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2966 freetree234(ssh->portfwds);
2967 ssh->portfwds = NULL;
2973 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2974 const char *error_msg, int error_code)
2976 Ssh ssh = (Ssh) plug;
2977 char addrbuf[256], *msg;
2979 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2982 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2984 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2990 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2993 Ssh ssh = (Ssh) plug;
2994 int need_notify = ssh_do_close(ssh, FALSE);
2997 if (!ssh->close_expected)
2998 error_msg = "Server unexpectedly closed network connection";
3000 error_msg = "Server closed network connection";
3003 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
3007 notify_remote_exit(ssh->frontend);
3010 logevent(error_msg);
3011 if (!ssh->close_expected || !ssh->clean_exit)
3012 connection_fatal(ssh->frontend, "%s", error_msg);
3016 static int ssh_receive(Plug plug, int urgent, char *data, int len)
3018 Ssh ssh = (Ssh) plug;
3019 ssh_gotdata(ssh, (unsigned char *)data, len);
3020 if (ssh->state == SSH_STATE_CLOSED) {
3021 ssh_do_close(ssh, TRUE);
3027 static void ssh_sent(Plug plug, int bufsize)
3029 Ssh ssh = (Ssh) plug;
3031 * If the send backlog on the SSH socket itself clears, we
3032 * should unthrottle the whole world if it was throttled.
3034 if (bufsize < SSH_MAX_BACKLOG)
3035 ssh_throttle_all(ssh, 0, bufsize);
3039 * Connect to specified host and port.
3040 * Returns an error message, or NULL on success.
3041 * Also places the canonical host name into `realhost'. It must be
3042 * freed by the caller.
3044 static const char *connect_to_host(Ssh ssh, char *host, int port,
3045 char **realhost, int nodelay, int keepalive)
3047 static const struct plug_function_table fn_table = {
3058 int addressfamily, sshprot;
3060 loghost = conf_get_str(ssh->conf, CONF_loghost);
3064 ssh->savedhost = dupstr(loghost);
3065 ssh->savedport = 22; /* default ssh port */
3068 * A colon suffix on savedhost also lets us affect
3071 * (FIXME: do something about IPv6 address literals here.)
3073 colon = strrchr(ssh->savedhost, ':');
3077 ssh->savedport = atoi(colon);
3080 ssh->savedhost = dupstr(host);
3082 port = 22; /* default ssh port */
3083 ssh->savedport = port;
3089 addressfamily = conf_get_int(ssh->conf, CONF_addressfamily);
3090 logeventf(ssh, "Looking up host \"%s\"%s", host,
3091 (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
3092 (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
3093 addr = name_lookup(host, port, realhost, ssh->conf, addressfamily);
3094 if ((err = sk_addr_error(addr)) != NULL) {
3098 ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */
3103 ssh->fn = &fn_table;
3104 ssh->s = new_connection(addr, *realhost, port,
3105 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf);
3106 if ((err = sk_socket_error(ssh->s)) != NULL) {
3108 notify_remote_exit(ssh->frontend);
3113 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3114 * send the version string too.
3116 sshprot = conf_get_int(ssh->conf, CONF_sshprot);
3121 ssh_send_verstring(ssh, NULL);
3125 * loghost, if configured, overrides realhost.
3129 *realhost = dupstr(loghost);
3136 * Throttle or unthrottle the SSH connection.
3138 static void ssh_throttle_conn(Ssh ssh, int adjust)
3140 int old_count = ssh->conn_throttle_count;
3141 ssh->conn_throttle_count += adjust;
3142 assert(ssh->conn_throttle_count >= 0);
3143 if (ssh->conn_throttle_count && !old_count) {
3144 ssh_set_frozen(ssh, 1);
3145 } else if (!ssh->conn_throttle_count && old_count) {
3146 ssh_set_frozen(ssh, 0);
3151 * Throttle or unthrottle _all_ local data streams (for when sends
3152 * on the SSH connection itself back up).
3154 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
3157 struct ssh_channel *c;
3159 if (enable == ssh->throttled_all)
3161 ssh->throttled_all = enable;
3162 ssh->overall_bufsize = bufsize;
3165 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
3167 case CHAN_MAINSESSION:
3169 * This is treated separately, outside the switch.
3173 x11_override_throttle(c->u.x11.s, enable);
3176 /* Agent channels require no buffer management. */
3179 pfd_override_throttle(c->u.pfd.s, enable);
3185 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
3187 Ssh ssh = (Ssh) sshv;
3189 ssh->agent_response = reply;
3190 ssh->agent_response_len = replylen;
3192 if (ssh->version == 1)
3193 do_ssh1_login(ssh, NULL, -1, NULL);
3195 do_ssh2_authconn(ssh, NULL, -1, NULL);
3198 static void ssh_dialog_callback(void *sshv, int ret)
3200 Ssh ssh = (Ssh) sshv;
3202 ssh->user_response = ret;
3204 if (ssh->version == 1)
3205 do_ssh1_login(ssh, NULL, -1, NULL);
3207 do_ssh2_transport(ssh, NULL, -1, NULL);
3210 * This may have unfrozen the SSH connection, so do a
3213 ssh_process_queued_incoming_data(ssh);
3216 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
3218 struct ssh_channel *c = (struct ssh_channel *)cv;
3220 void *sentreply = reply;
3222 c->u.a.outstanding_requests--;
3224 /* Fake SSH_AGENT_FAILURE. */
3225 sentreply = "\0\0\0\1\5";
3228 if (ssh->version == 2) {
3229 ssh2_add_channel_data(c, sentreply, replylen);
3232 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3233 PKT_INT, c->remoteid,
3236 PKT_DATA, sentreply, replylen,
3243 * If we've already seen an incoming EOF but haven't sent an
3244 * outgoing one, this may be the moment to send it.
3246 if (c->u.a.outstanding_requests == 0 && (c->closes & CLOSES_RCVD_EOF))
3247 sshfwd_write_eof(c);
3251 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3252 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3253 * => log `wire_reason'.
3255 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
3256 int code, int clean_exit)
3260 client_reason = wire_reason;
3262 error = dupprintf("Disconnected: %s", client_reason);
3264 error = dupstr("Disconnected");
3266 if (ssh->version == 1) {
3267 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
3269 } else if (ssh->version == 2) {
3270 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
3271 ssh2_pkt_adduint32(pktout, code);
3272 ssh2_pkt_addstring(pktout, wire_reason);
3273 ssh2_pkt_addstring(pktout, "en"); /* language tag */
3274 ssh2_pkt_send_noqueue(ssh, pktout);
3277 ssh->close_expected = TRUE;
3278 ssh->clean_exit = clean_exit;
3279 ssh_closing((Plug)ssh, error, 0, 0);
3284 * Handle the key exchange and user authentication phases.
3286 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
3287 struct Packet *pktin)
3290 unsigned char cookie[8], *ptr;
3291 struct MD5Context md5c;
3292 struct do_ssh1_login_state {
3295 unsigned char *rsabuf, *keystr1, *keystr2;
3296 unsigned long supported_ciphers_mask, supported_auths_mask;
3297 int tried_publickey, tried_agent;
3298 int tis_auth_refused, ccard_auth_refused;
3299 unsigned char session_id[16];
3301 void *publickey_blob;
3302 int publickey_bloblen;
3303 char *publickey_comment;
3304 int publickey_encrypted;
3305 prompts_t *cur_prompt;
3308 unsigned char request[5], *response, *p;
3318 struct RSAKey servkey, hostkey;
3320 crState(do_ssh1_login_state);
3327 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3328 bombout(("Public key packet not received"));
3332 logevent("Received public keys");
3334 ptr = ssh_pkt_getdata(pktin, 8);
3336 bombout(("SSH-1 public key packet stopped before random cookie"));
3339 memcpy(cookie, ptr, 8);
3341 if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) ||
3342 !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) {
3343 bombout(("Failed to read SSH-1 public keys from public key packet"));
3348 * Log the host key fingerprint.
3352 logevent("Host key fingerprint is:");
3353 strcpy(logmsg, " ");
3354 s->hostkey.comment = NULL;
3355 rsa_fingerprint(logmsg + strlen(logmsg),
3356 sizeof(logmsg) - strlen(logmsg), &s->hostkey);
3360 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3361 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3362 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3363 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA))
3364 s->supported_auths_mask &= ~(1 << SSH1_AUTH_RSA);
3366 ssh->v1_local_protoflags =
3367 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3368 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3371 MD5Update(&md5c, s->keystr2, s->hostkey.bytes);
3372 MD5Update(&md5c, s->keystr1, s->servkey.bytes);
3373 MD5Update(&md5c, cookie, 8);
3374 MD5Final(s->session_id, &md5c);
3376 for (i = 0; i < 32; i++)
3377 ssh->session_key[i] = random_byte();
3380 * Verify that the `bits' and `bytes' parameters match.
3382 if (s->hostkey.bits > s->hostkey.bytes * 8 ||
3383 s->servkey.bits > s->servkey.bytes * 8) {
3384 bombout(("SSH-1 public keys were badly formatted"));
3388 s->len = (s->hostkey.bytes > s->servkey.bytes ?
3389 s->hostkey.bytes : s->servkey.bytes);
3391 s->rsabuf = snewn(s->len, unsigned char);
3394 * Verify the host key.
3398 * First format the key into a string.
3400 int len = rsastr_len(&s->hostkey);
3401 char fingerprint[100];
3402 char *keystr = snewn(len, char);
3403 rsastr_fmt(keystr, &s->hostkey);
3404 rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey);
3406 ssh_set_frozen(ssh, 1);
3407 s->dlgret = verify_ssh_host_key(ssh->frontend,
3408 ssh->savedhost, ssh->savedport,
3409 "rsa", keystr, fingerprint,
3410 ssh_dialog_callback, ssh);
3412 if (s->dlgret < 0) {
3416 bombout(("Unexpected data from server while waiting"
3417 " for user host key response"));
3420 } while (pktin || inlen > 0);
3421 s->dlgret = ssh->user_response;
3423 ssh_set_frozen(ssh, 0);
3425 if (s->dlgret == 0) {
3426 ssh_disconnect(ssh, "User aborted at host key verification",
3432 for (i = 0; i < 32; i++) {
3433 s->rsabuf[i] = ssh->session_key[i];
3435 s->rsabuf[i] ^= s->session_id[i];
3438 if (s->hostkey.bytes > s->servkey.bytes) {
3439 ret = rsaencrypt(s->rsabuf, 32, &s->servkey);
3441 ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey);
3443 ret = rsaencrypt(s->rsabuf, 32, &s->hostkey);
3445 ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey);
3448 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3452 logevent("Encrypted session key");
3455 int cipher_chosen = 0, warn = 0;
3456 char *cipher_string = NULL;
3458 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3459 int next_cipher = conf_get_int_int(ssh->conf,
3460 CONF_ssh_cipherlist, i);
3461 if (next_cipher == CIPHER_WARN) {
3462 /* If/when we choose a cipher, warn about it */
3464 } else if (next_cipher == CIPHER_AES) {
3465 /* XXX Probably don't need to mention this. */
3466 logevent("AES not supported in SSH-1, skipping");
3468 switch (next_cipher) {
3469 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3470 cipher_string = "3DES"; break;
3471 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3472 cipher_string = "Blowfish"; break;
3473 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3474 cipher_string = "single-DES"; break;
3476 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3480 if (!cipher_chosen) {
3481 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3482 bombout(("Server violates SSH-1 protocol by not "
3483 "supporting 3DES encryption"));
3485 /* shouldn't happen */
3486 bombout(("No supported ciphers found"));
3490 /* Warn about chosen cipher if necessary. */
3492 ssh_set_frozen(ssh, 1);
3493 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3494 ssh_dialog_callback, ssh);
3495 if (s->dlgret < 0) {
3499 bombout(("Unexpected data from server while waiting"
3500 " for user response"));
3503 } while (pktin || inlen > 0);
3504 s->dlgret = ssh->user_response;
3506 ssh_set_frozen(ssh, 0);
3507 if (s->dlgret == 0) {
3508 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3515 switch (s->cipher_type) {
3516 case SSH_CIPHER_3DES:
3517 logevent("Using 3DES encryption");
3519 case SSH_CIPHER_DES:
3520 logevent("Using single-DES encryption");
3522 case SSH_CIPHER_BLOWFISH:
3523 logevent("Using Blowfish encryption");
3527 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3528 PKT_CHAR, s->cipher_type,
3529 PKT_DATA, cookie, 8,
3530 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3531 PKT_DATA, s->rsabuf, s->len,
3532 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3534 logevent("Trying to enable encryption...");
3538 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3539 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3541 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3542 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3543 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3545 ssh->crcda_ctx = crcda_make_context();
3546 logevent("Installing CRC compensation attack detector");
3548 if (s->servkey.modulus) {
3549 sfree(s->servkey.modulus);
3550 s->servkey.modulus = NULL;
3552 if (s->servkey.exponent) {
3553 sfree(s->servkey.exponent);
3554 s->servkey.exponent = NULL;
3556 if (s->hostkey.modulus) {
3557 sfree(s->hostkey.modulus);
3558 s->hostkey.modulus = NULL;
3560 if (s->hostkey.exponent) {
3561 sfree(s->hostkey.exponent);
3562 s->hostkey.exponent = NULL;
3566 if (pktin->type != SSH1_SMSG_SUCCESS) {
3567 bombout(("Encryption not successfully enabled"));
3571 logevent("Successfully started encryption");
3573 fflush(stdout); /* FIXME eh? */
3575 if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
3576 int ret; /* need not be kept over crReturn */
3577 s->cur_prompt = new_prompts(ssh->frontend);
3578 s->cur_prompt->to_server = TRUE;
3579 s->cur_prompt->name = dupstr("SSH login name");
3580 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
3581 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3584 crWaitUntil(!pktin);
3585 ret = get_userpass_input(s->cur_prompt, in, inlen);
3590 * Failed to get a username. Terminate.
3592 free_prompts(s->cur_prompt);
3593 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3596 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
3597 free_prompts(s->cur_prompt);
3600 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, ssh->username, PKT_END);
3602 char *userlog = dupprintf("Sent username \"%s\"", ssh->username);
3604 if (flags & FLAG_INTERACTIVE &&
3605 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3606 c_write_str(ssh, userlog);
3607 c_write_str(ssh, "\r\n");
3615 if ((s->supported_auths_mask & (1 << SSH1_AUTH_RSA)) == 0) {
3616 /* We must not attempt PK auth. Pretend we've already tried it. */
3617 s->tried_publickey = s->tried_agent = 1;
3619 s->tried_publickey = s->tried_agent = 0;
3621 s->tis_auth_refused = s->ccard_auth_refused = 0;
3623 * Load the public half of any configured keyfile for later use.
3625 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3626 if (!filename_is_null(s->keyfile)) {
3628 logeventf(ssh, "Reading private key file \"%.150s\"",
3629 filename_to_str(s->keyfile));
3630 keytype = key_type(s->keyfile);
3631 if (keytype == SSH_KEYTYPE_SSH1) {
3633 if (rsakey_pubblob(s->keyfile,
3634 &s->publickey_blob, &s->publickey_bloblen,
3635 &s->publickey_comment, &error)) {
3636 s->publickey_encrypted = rsakey_encrypted(s->keyfile,
3640 logeventf(ssh, "Unable to load private key (%s)", error);
3641 msgbuf = dupprintf("Unable to load private key file "
3642 "\"%.150s\" (%s)\r\n",
3643 filename_to_str(s->keyfile),
3645 c_write_str(ssh, msgbuf);
3647 s->publickey_blob = NULL;
3651 logeventf(ssh, "Unable to use this key file (%s)",
3652 key_type_to_str(keytype));
3653 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3655 filename_to_str(s->keyfile),
3656 key_type_to_str(keytype));
3657 c_write_str(ssh, msgbuf);
3659 s->publickey_blob = NULL;
3662 s->publickey_blob = NULL;
3664 while (pktin->type == SSH1_SMSG_FAILURE) {
3665 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3667 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists() && !s->tried_agent) {
3669 * Attempt RSA authentication using Pageant.
3675 logevent("Pageant is running. Requesting keys.");
3677 /* Request the keys held by the agent. */
3678 PUT_32BIT(s->request, 1);
3679 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3680 if (!agent_query(s->request, 5, &r, &s->responselen,
3681 ssh_agent_callback, ssh)) {
3685 bombout(("Unexpected data from server while waiting"
3686 " for agent response"));
3689 } while (pktin || inlen > 0);
3690 r = ssh->agent_response;
3691 s->responselen = ssh->agent_response_len;
3693 s->response = (unsigned char *) r;
3694 if (s->response && s->responselen >= 5 &&
3695 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3696 s->p = s->response + 5;
3697 s->nkeys = toint(GET_32BIT(s->p));
3699 logeventf(ssh, "Pageant reported negative key count %d",
3704 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3705 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3706 unsigned char *pkblob = s->p;
3710 do { /* do while (0) to make breaking easy */
3711 n = ssh1_read_bignum
3712 (s->p, toint(s->responselen-(s->p-s->response)),
3717 n = ssh1_read_bignum
3718 (s->p, toint(s->responselen-(s->p-s->response)),
3723 if (s->responselen - (s->p-s->response) < 4)
3725 s->commentlen = toint(GET_32BIT(s->p));
3727 if (s->commentlen < 0 ||
3728 toint(s->responselen - (s->p-s->response)) <
3731 s->commentp = (char *)s->p;
3732 s->p += s->commentlen;
3736 logevent("Pageant key list packet was truncated");
3740 if (s->publickey_blob) {
3741 if (!memcmp(pkblob, s->publickey_blob,
3742 s->publickey_bloblen)) {
3743 logeventf(ssh, "Pageant key #%d matches "
3744 "configured key file", s->keyi);
3745 s->tried_publickey = 1;
3747 /* Skip non-configured key */
3750 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3751 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3752 PKT_BIGNUM, s->key.modulus, PKT_END);
3754 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3755 logevent("Key refused");
3758 logevent("Received RSA challenge");
3759 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3760 bombout(("Server's RSA challenge was badly formatted"));
3765 char *agentreq, *q, *ret;
3768 len = 1 + 4; /* message type, bit count */
3769 len += ssh1_bignum_length(s->key.exponent);
3770 len += ssh1_bignum_length(s->key.modulus);
3771 len += ssh1_bignum_length(s->challenge);
3772 len += 16; /* session id */
3773 len += 4; /* response format */
3774 agentreq = snewn(4 + len, char);
3775 PUT_32BIT(agentreq, len);
3777 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3778 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3780 q += ssh1_write_bignum(q, s->key.exponent);
3781 q += ssh1_write_bignum(q, s->key.modulus);
3782 q += ssh1_write_bignum(q, s->challenge);
3783 memcpy(q, s->session_id, 16);
3785 PUT_32BIT(q, 1); /* response format */
3786 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3787 ssh_agent_callback, ssh)) {
3792 bombout(("Unexpected data from server"
3793 " while waiting for agent"
3797 } while (pktin || inlen > 0);
3798 vret = ssh->agent_response;
3799 retlen = ssh->agent_response_len;
3804 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3805 logevent("Sending Pageant's response");
3806 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3807 PKT_DATA, ret + 5, 16,
3811 if (pktin->type == SSH1_SMSG_SUCCESS) {
3813 ("Pageant's response accepted");
3814 if (flags & FLAG_VERBOSE) {
3815 c_write_str(ssh, "Authenticated using"
3817 c_write(ssh, s->commentp,
3819 c_write_str(ssh, "\" from agent\r\n");
3824 ("Pageant's response not accepted");
3827 ("Pageant failed to answer challenge");
3831 logevent("No reply received from Pageant");
3834 freebn(s->key.exponent);
3835 freebn(s->key.modulus);
3836 freebn(s->challenge);
3841 if (s->publickey_blob && !s->tried_publickey)
3842 logevent("Configured key file not in Pageant");
3844 logevent("Failed to get reply from Pageant");
3849 if (s->publickey_blob && !s->tried_publickey) {
3851 * Try public key authentication with the specified
3854 int got_passphrase; /* need not be kept over crReturn */
3855 if (flags & FLAG_VERBOSE)
3856 c_write_str(ssh, "Trying public key authentication.\r\n");
3857 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3858 logeventf(ssh, "Trying public key \"%s\"",
3859 filename_to_str(s->keyfile));
3860 s->tried_publickey = 1;
3861 got_passphrase = FALSE;
3862 while (!got_passphrase) {
3864 * Get a passphrase, if necessary.
3866 char *passphrase = NULL; /* only written after crReturn */
3868 if (!s->publickey_encrypted) {
3869 if (flags & FLAG_VERBOSE)
3870 c_write_str(ssh, "No passphrase required.\r\n");
3873 int ret; /* need not be kept over crReturn */
3874 s->cur_prompt = new_prompts(ssh->frontend);
3875 s->cur_prompt->to_server = FALSE;
3876 s->cur_prompt->name = dupstr("SSH key passphrase");
3877 add_prompt(s->cur_prompt,
3878 dupprintf("Passphrase for key \"%.100s\": ",
3879 s->publickey_comment), FALSE);
3880 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3883 crWaitUntil(!pktin);
3884 ret = get_userpass_input(s->cur_prompt, in, inlen);
3888 /* Failed to get a passphrase. Terminate. */
3889 free_prompts(s->cur_prompt);
3890 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3894 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3895 free_prompts(s->cur_prompt);
3898 * Try decrypting key with passphrase.
3900 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
3901 ret = loadrsakey(s->keyfile, &s->key, passphrase,
3904 smemclr(passphrase, strlen(passphrase));
3908 /* Correct passphrase. */
3909 got_passphrase = TRUE;
3910 } else if (ret == 0) {
3911 c_write_str(ssh, "Couldn't load private key from ");
3912 c_write_str(ssh, filename_to_str(s->keyfile));
3913 c_write_str(ssh, " (");
3914 c_write_str(ssh, error);
3915 c_write_str(ssh, ").\r\n");
3916 got_passphrase = FALSE;
3917 break; /* go and try something else */
3918 } else if (ret == -1) {
3919 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3920 got_passphrase = FALSE;
3923 assert(0 && "unexpected return from loadrsakey()");
3924 got_passphrase = FALSE; /* placate optimisers */
3928 if (got_passphrase) {
3931 * Send a public key attempt.
3933 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3934 PKT_BIGNUM, s->key.modulus, PKT_END);
3937 if (pktin->type == SSH1_SMSG_FAILURE) {
3938 c_write_str(ssh, "Server refused our public key.\r\n");
3939 continue; /* go and try something else */
3941 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3942 bombout(("Bizarre response to offer of public key"));
3948 unsigned char buffer[32];
3949 Bignum challenge, response;
3951 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3952 bombout(("Server's RSA challenge was badly formatted"));
3955 response = rsadecrypt(challenge, &s->key);
3956 freebn(s->key.private_exponent);/* burn the evidence */
3958 for (i = 0; i < 32; i++) {
3959 buffer[i] = bignum_byte(response, 31 - i);
3963 MD5Update(&md5c, buffer, 32);
3964 MD5Update(&md5c, s->session_id, 16);
3965 MD5Final(buffer, &md5c);
3967 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3968 PKT_DATA, buffer, 16, PKT_END);
3975 if (pktin->type == SSH1_SMSG_FAILURE) {
3976 if (flags & FLAG_VERBOSE)
3977 c_write_str(ssh, "Failed to authenticate with"
3978 " our public key.\r\n");
3979 continue; /* go and try something else */
3980 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3981 bombout(("Bizarre response to RSA authentication response"));
3985 break; /* we're through! */
3991 * Otherwise, try various forms of password-like authentication.
3993 s->cur_prompt = new_prompts(ssh->frontend);
3995 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
3996 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3997 !s->tis_auth_refused) {
3998 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3999 logevent("Requested TIS authentication");
4000 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
4002 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
4003 logevent("TIS authentication declined");
4004 if (flags & FLAG_INTERACTIVE)
4005 c_write_str(ssh, "TIS authentication refused.\r\n");
4006 s->tis_auth_refused = 1;
4011 char *instr_suf, *prompt;
4013 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4015 bombout(("TIS challenge packet was badly formed"));
4018 logevent("Received TIS challenge");
4019 s->cur_prompt->to_server = TRUE;
4020 s->cur_prompt->name = dupstr("SSH TIS authentication");
4021 /* Prompt heuristic comes from OpenSSH */
4022 if (memchr(challenge, '\n', challengelen)) {
4023 instr_suf = dupstr("");
4024 prompt = dupprintf("%.*s", challengelen, challenge);
4026 instr_suf = dupprintf("%.*s", challengelen, challenge);
4027 prompt = dupstr("Response: ");
4029 s->cur_prompt->instruction =
4030 dupprintf("Using TIS authentication.%s%s",
4031 (*instr_suf) ? "\n" : "",
4033 s->cur_prompt->instr_reqd = TRUE;
4034 add_prompt(s->cur_prompt, prompt, FALSE);
4038 if (conf_get_int(ssh->conf, CONF_try_tis_auth) &&
4039 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
4040 !s->ccard_auth_refused) {
4041 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
4042 logevent("Requested CryptoCard authentication");
4043 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
4045 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
4046 logevent("CryptoCard authentication declined");
4047 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
4048 s->ccard_auth_refused = 1;
4053 char *instr_suf, *prompt;
4055 ssh_pkt_getstring(pktin, &challenge, &challengelen);
4057 bombout(("CryptoCard challenge packet was badly formed"));
4060 logevent("Received CryptoCard challenge");
4061 s->cur_prompt->to_server = TRUE;
4062 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
4063 s->cur_prompt->name_reqd = FALSE;
4064 /* Prompt heuristic comes from OpenSSH */
4065 if (memchr(challenge, '\n', challengelen)) {
4066 instr_suf = dupstr("");
4067 prompt = dupprintf("%.*s", challengelen, challenge);
4069 instr_suf = dupprintf("%.*s", challengelen, challenge);
4070 prompt = dupstr("Response: ");
4072 s->cur_prompt->instruction =
4073 dupprintf("Using CryptoCard authentication.%s%s",
4074 (*instr_suf) ? "\n" : "",
4076 s->cur_prompt->instr_reqd = TRUE;
4077 add_prompt(s->cur_prompt, prompt, FALSE);
4081 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4082 if ((s->supported_auths_mask & (1 << SSH1_AUTH_PASSWORD)) == 0) {
4083 bombout(("No supported authentication methods available"));
4086 s->cur_prompt->to_server = TRUE;
4087 s->cur_prompt->name = dupstr("SSH password");
4088 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
4089 ssh->username, ssh->savedhost),
4094 * Show password prompt, having first obtained it via a TIS
4095 * or CryptoCard exchange if we're doing TIS or CryptoCard
4099 int ret; /* need not be kept over crReturn */
4100 ret = get_userpass_input(s->cur_prompt, NULL, 0);
4103 crWaitUntil(!pktin);
4104 ret = get_userpass_input(s->cur_prompt, in, inlen);
4109 * Failed to get a password (for example
4110 * because one was supplied on the command line
4111 * which has already failed to work). Terminate.
4113 free_prompts(s->cur_prompt);
4114 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
4119 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
4121 * Defence against traffic analysis: we send a
4122 * whole bunch of packets containing strings of
4123 * different lengths. One of these strings is the
4124 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4125 * The others are all random data in
4126 * SSH1_MSG_IGNORE packets. This way a passive
4127 * listener can't tell which is the password, and
4128 * hence can't deduce the password length.
4130 * Anybody with a password length greater than 16
4131 * bytes is going to have enough entropy in their
4132 * password that a listener won't find it _that_
4133 * much help to know how long it is. So what we'll
4136 * - if password length < 16, we send 15 packets
4137 * containing string lengths 1 through 15
4139 * - otherwise, we let N be the nearest multiple
4140 * of 8 below the password length, and send 8
4141 * packets containing string lengths N through
4142 * N+7. This won't obscure the order of
4143 * magnitude of the password length, but it will
4144 * introduce a bit of extra uncertainty.
4146 * A few servers can't deal with SSH1_MSG_IGNORE, at
4147 * least in this context. For these servers, we need
4148 * an alternative defence. We make use of the fact
4149 * that the password is interpreted as a C string:
4150 * so we can append a NUL, then some random data.
4152 * A few servers can deal with neither SSH1_MSG_IGNORE
4153 * here _nor_ a padded password string.
4154 * For these servers we are left with no defences
4155 * against password length sniffing.
4157 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
4158 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4160 * The server can deal with SSH1_MSG_IGNORE, so
4161 * we can use the primary defence.
4163 int bottom, top, pwlen, i;
4166 pwlen = strlen(s->cur_prompt->prompts[0]->result);
4168 bottom = 0; /* zero length passwords are OK! :-) */
4171 bottom = pwlen & ~7;
4175 assert(pwlen >= bottom && pwlen <= top);
4177 randomstr = snewn(top + 1, char);
4179 for (i = bottom; i <= top; i++) {
4181 defer_packet(ssh, s->pwpkt_type,
4182 PKTT_PASSWORD, PKT_STR,
4183 s->cur_prompt->prompts[0]->result,
4184 PKTT_OTHER, PKT_END);
4186 for (j = 0; j < i; j++) {
4188 randomstr[j] = random_byte();
4189 } while (randomstr[j] == '\0');
4191 randomstr[i] = '\0';
4192 defer_packet(ssh, SSH1_MSG_IGNORE,
4193 PKT_STR, randomstr, PKT_END);
4196 logevent("Sending password with camouflage packets");
4197 ssh_pkt_defersend(ssh);
4200 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
4202 * The server can't deal with SSH1_MSG_IGNORE
4203 * but can deal with padded passwords, so we
4204 * can use the secondary defence.
4210 len = strlen(s->cur_prompt->prompts[0]->result);
4211 if (len < sizeof(string)) {
4213 strcpy(string, s->cur_prompt->prompts[0]->result);
4214 len++; /* cover the zero byte */
4215 while (len < sizeof(string)) {
4216 string[len++] = (char) random_byte();
4219 ss = s->cur_prompt->prompts[0]->result;
4221 logevent("Sending length-padded password");
4222 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4223 PKT_INT, len, PKT_DATA, ss, len,
4224 PKTT_OTHER, PKT_END);
4227 * The server is believed unable to cope with
4228 * any of our password camouflage methods.
4231 len = strlen(s->cur_prompt->prompts[0]->result);
4232 logevent("Sending unpadded password");
4233 send_packet(ssh, s->pwpkt_type,
4234 PKTT_PASSWORD, PKT_INT, len,
4235 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
4236 PKTT_OTHER, PKT_END);
4239 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
4240 PKT_STR, s->cur_prompt->prompts[0]->result,
4241 PKTT_OTHER, PKT_END);
4243 logevent("Sent password");
4244 free_prompts(s->cur_prompt);
4246 if (pktin->type == SSH1_SMSG_FAILURE) {
4247 if (flags & FLAG_VERBOSE)
4248 c_write_str(ssh, "Access denied\r\n");
4249 logevent("Authentication refused");
4250 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
4251 bombout(("Strange packet received, type %d", pktin->type));
4257 if (s->publickey_blob) {
4258 sfree(s->publickey_blob);
4259 sfree(s->publickey_comment);
4262 logevent("Authentication successful");
4267 static void ssh_channel_try_eof(struct ssh_channel *c)
4270 assert(c->pending_eof); /* precondition for calling us */
4272 return; /* can't close: not even opened yet */
4273 if (ssh->version == 2 && bufchain_size(&c->v.v2.outbuffer) > 0)
4274 return; /* can't send EOF: pending outgoing data */
4276 c->pending_eof = FALSE; /* we're about to send it */
4277 if (ssh->version == 1) {
4278 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
4280 c->closes |= CLOSES_SENT_EOF;
4282 struct Packet *pktout;
4283 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
4284 ssh2_pkt_adduint32(pktout, c->remoteid);
4285 ssh2_pkt_send(ssh, pktout);
4286 c->closes |= CLOSES_SENT_EOF;
4287 ssh2_channel_check_close(c);
4291 void sshfwd_write_eof(struct ssh_channel *c)
4295 if (ssh->state == SSH_STATE_CLOSED)
4298 if (c->closes & CLOSES_SENT_EOF)
4301 c->pending_eof = TRUE;
4302 ssh_channel_try_eof(c);
4305 void sshfwd_unclean_close(struct ssh_channel *c, const char *err)
4309 if (ssh->state == SSH_STATE_CLOSED)
4314 x11_close(c->u.x11.s);
4315 logeventf(ssh, "Forwarded X11 connection terminated due to local "
4319 case CHAN_SOCKDATA_DORMANT:
4320 pfd_close(c->u.pfd.s);
4321 logeventf(ssh, "Forwarded port closed due to local error: %s", err);
4324 c->type = CHAN_ZOMBIE;
4326 ssh2_channel_check_close(c);
4329 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
4333 if (ssh->state == SSH_STATE_CLOSED)
4336 if (ssh->version == 1) {
4337 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4338 PKT_INT, c->remoteid,
4339 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
4340 PKTT_OTHER, PKT_END);
4342 * In SSH-1 we can return 0 here - implying that forwarded
4343 * connections are never individually throttled - because
4344 * the only circumstance that can cause throttling will be
4345 * the whole SSH connection backing up, in which case
4346 * _everything_ will be throttled as a whole.
4350 ssh2_add_channel_data(c, buf, len);
4351 return ssh2_try_send(c);
4355 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4360 if (ssh->state == SSH_STATE_CLOSED)
4363 if (ssh->version == 1) {
4364 buflimit = SSH1_BUFFER_LIMIT;
4366 buflimit = c->v.v2.locmaxwin;
4367 ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0);
4369 if (c->throttling_conn && bufsize <= buflimit) {
4370 c->throttling_conn = 0;
4371 ssh_throttle_conn(ssh, -1);
4375 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4377 struct queued_handler *qh = ssh->qhead;
4381 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4384 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4385 ssh->packet_dispatch[qh->msg1] = ssh->q_saved_handler1;
4388 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4389 ssh->packet_dispatch[qh->msg2] = ssh->q_saved_handler2;
4393 ssh->qhead = qh->next;
4395 if (ssh->qhead->msg1 > 0) {
4396 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4397 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4399 if (ssh->qhead->msg2 > 0) {
4400 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4401 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4404 ssh->qhead = ssh->qtail = NULL;
4407 qh->handler(ssh, pktin, qh->ctx);
4412 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4413 chandler_fn_t handler, void *ctx)
4415 struct queued_handler *qh;
4417 qh = snew(struct queued_handler);
4420 qh->handler = handler;
4424 if (ssh->qtail == NULL) {
4428 ssh->q_saved_handler1 = ssh->packet_dispatch[ssh->qhead->msg1];
4429 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4432 ssh->q_saved_handler2 = ssh->packet_dispatch[ssh->qhead->msg2];
4433 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4436 ssh->qtail->next = qh;
4441 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4443 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4445 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4446 SSH2_MSG_REQUEST_SUCCESS)) {
4447 logeventf(ssh, "Remote port forwarding from %s enabled",
4450 logeventf(ssh, "Remote port forwarding from %s refused",
4453 rpf = del234(ssh->rportfwds, pf);
4455 pf->pfrec->remote = NULL;
4460 static void ssh_setup_portfwd(Ssh ssh, Conf *conf)
4462 struct ssh_portfwd *epf;
4466 if (!ssh->portfwds) {
4467 ssh->portfwds = newtree234(ssh_portcmp);
4470 * Go through the existing port forwardings and tag them
4471 * with status==DESTROY. Any that we want to keep will be
4472 * re-enabled (status==KEEP) as we go through the
4473 * configuration and find out which bits are the same as
4476 struct ssh_portfwd *epf;
4478 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4479 epf->status = DESTROY;
4482 for (val = conf_get_str_strs(conf, CONF_portfwd, NULL, &key);
4484 val = conf_get_str_strs(conf, CONF_portfwd, key, &key)) {
4485 char *kp, *kp2, *vp, *vp2;
4486 char address_family, type;
4487 int sport,dport,sserv,dserv;
4488 char *sports, *dports, *saddr, *host;
4492 address_family = 'A';
4494 if (*kp == 'A' || *kp == '4' || *kp == '6')
4495 address_family = *kp++;
4496 if (*kp == 'L' || *kp == 'R')
4499 if ((kp2 = strchr(kp, ':')) != NULL) {
4501 * There's a colon in the middle of the source port
4502 * string, which means that the part before it is
4503 * actually a source address.
4505 saddr = dupprintf("%.*s", (int)(kp2 - kp), kp);
4511 sport = atoi(sports);
4515 sport = net_service_lookup(sports);
4517 logeventf(ssh, "Service lookup failed for source"
4518 " port \"%s\"", sports);
4522 if (type == 'L' && !strcmp(val, "D")) {
4523 /* dynamic forwarding */
4530 /* ordinary forwarding */
4532 vp2 = vp + strcspn(vp, ":");
4533 host = dupprintf("%.*s", (int)(vp2 - vp), vp);
4537 dport = atoi(dports);
4541 dport = net_service_lookup(dports);
4543 logeventf(ssh, "Service lookup failed for destination"
4544 " port \"%s\"", dports);
4549 if (sport && dport) {
4550 /* Set up a description of the source port. */
4551 struct ssh_portfwd *pfrec, *epfrec;
4553 pfrec = snew(struct ssh_portfwd);
4555 pfrec->saddr = saddr;
4556 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4557 pfrec->sport = sport;
4558 pfrec->daddr = host;
4559 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4560 pfrec->dport = dport;
4561 pfrec->local = NULL;
4562 pfrec->remote = NULL;
4563 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4564 address_family == '6' ? ADDRTYPE_IPV6 :
4567 epfrec = add234(ssh->portfwds, pfrec);
4568 if (epfrec != pfrec) {
4569 if (epfrec->status == DESTROY) {
4571 * We already have a port forwarding up and running
4572 * with precisely these parameters. Hence, no need
4573 * to do anything; simply re-tag the existing one
4576 epfrec->status = KEEP;
4579 * Anything else indicates that there was a duplicate
4580 * in our input, which we'll silently ignore.
4582 free_portfwd(pfrec);
4584 pfrec->status = CREATE;
4593 * Now go through and destroy any port forwardings which were
4596 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4597 if (epf->status == DESTROY) {
4600 message = dupprintf("%s port forwarding from %s%s%d",
4601 epf->type == 'L' ? "local" :
4602 epf->type == 'R' ? "remote" : "dynamic",
4603 epf->saddr ? epf->saddr : "",
4604 epf->saddr ? ":" : "",
4607 if (epf->type != 'D') {
4608 char *msg2 = dupprintf("%s to %s:%d", message,
4609 epf->daddr, epf->dport);
4614 logeventf(ssh, "Cancelling %s", message);
4617 /* epf->remote or epf->local may be NULL if setting up a
4618 * forwarding failed. */
4620 struct ssh_rportfwd *rpf = epf->remote;
4621 struct Packet *pktout;
4624 * Cancel the port forwarding at the server
4627 if (ssh->version == 1) {
4629 * We cannot cancel listening ports on the
4630 * server side in SSH-1! There's no message
4631 * to support it. Instead, we simply remove
4632 * the rportfwd record from the local end
4633 * so that any connections the server tries
4634 * to make on it are rejected.
4637 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4638 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4639 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4641 ssh2_pkt_addstring(pktout, epf->saddr);
4642 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4643 /* XXX: rport_acceptall may not represent
4644 * what was used to open the original connection,
4645 * since it's reconfigurable. */
4646 ssh2_pkt_addstring(pktout, "");
4648 ssh2_pkt_addstring(pktout, "localhost");
4650 ssh2_pkt_adduint32(pktout, epf->sport);
4651 ssh2_pkt_send(ssh, pktout);
4654 del234(ssh->rportfwds, rpf);
4656 } else if (epf->local) {
4657 pfd_terminate(epf->local);
4660 delpos234(ssh->portfwds, i);
4662 i--; /* so we don't skip one in the list */
4666 * And finally, set up any new port forwardings (status==CREATE).
4668 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4669 if (epf->status == CREATE) {
4670 char *sportdesc, *dportdesc;
4671 sportdesc = dupprintf("%s%s%s%s%d%s",
4672 epf->saddr ? epf->saddr : "",
4673 epf->saddr ? ":" : "",
4674 epf->sserv ? epf->sserv : "",
4675 epf->sserv ? "(" : "",
4677 epf->sserv ? ")" : "");
4678 if (epf->type == 'D') {
4681 dportdesc = dupprintf("%s:%s%s%d%s",
4683 epf->dserv ? epf->dserv : "",
4684 epf->dserv ? "(" : "",
4686 epf->dserv ? ")" : "");
4689 if (epf->type == 'L') {
4690 const char *err = pfd_addforward(epf->daddr, epf->dport,
4691 epf->saddr, epf->sport,
4694 epf->addressfamily);
4696 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4697 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4698 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4699 sportdesc, dportdesc,
4700 err ? " failed: " : "", err ? err : "");
4701 } else if (epf->type == 'D') {
4702 const char *err = pfd_addforward(NULL, -1,
4703 epf->saddr, epf->sport,
4706 epf->addressfamily);
4708 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4709 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4710 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4712 err ? " failed: " : "", err ? err : "");
4714 struct ssh_rportfwd *pf;
4717 * Ensure the remote port forwardings tree exists.
4719 if (!ssh->rportfwds) {
4720 if (ssh->version == 1)
4721 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4723 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4726 pf = snew(struct ssh_rportfwd);
4727 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4728 pf->dhost[lenof(pf->dhost)-1] = '\0';
4729 pf->dport = epf->dport;
4730 pf->sport = epf->sport;
4731 if (add234(ssh->rportfwds, pf) != pf) {
4732 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4733 epf->daddr, epf->dport);
4736 logeventf(ssh, "Requesting remote port %s"
4737 " forward to %s", sportdesc, dportdesc);
4739 pf->sportdesc = sportdesc;
4744 if (ssh->version == 1) {
4745 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4746 PKT_INT, epf->sport,
4747 PKT_STR, epf->daddr,
4748 PKT_INT, epf->dport,
4750 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4752 ssh_rportfwd_succfail, pf);
4754 struct Packet *pktout;
4755 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4756 ssh2_pkt_addstring(pktout, "tcpip-forward");
4757 ssh2_pkt_addbool(pktout, 1);/* want reply */
4759 ssh2_pkt_addstring(pktout, epf->saddr);
4760 } else if (conf_get_int(conf, CONF_rport_acceptall)) {
4761 ssh2_pkt_addstring(pktout, "");
4763 ssh2_pkt_addstring(pktout, "localhost");
4765 ssh2_pkt_adduint32(pktout, epf->sport);
4766 ssh2_pkt_send(ssh, pktout);
4768 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4769 SSH2_MSG_REQUEST_FAILURE,
4770 ssh_rportfwd_succfail, pf);
4779 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4782 int stringlen, bufsize;
4784 ssh_pkt_getstring(pktin, &string, &stringlen);
4785 if (string == NULL) {
4786 bombout(("Incoming terminal data packet was badly formed"));
4790 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4792 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4793 ssh->v1_stdout_throttling = 1;
4794 ssh_throttle_conn(ssh, +1);
4798 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4800 /* Remote side is trying to open a channel to talk to our
4801 * X-Server. Give them back a local channel number. */
4802 struct ssh_channel *c;
4803 int remoteid = ssh_pkt_getuint32(pktin);
4805 logevent("Received X11 connect request");
4806 /* Refuse if X11 forwarding is disabled. */
4807 if (!ssh->X11_fwd_enabled) {
4808 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4809 PKT_INT, remoteid, PKT_END);
4810 logevent("Rejected X11 connect request");
4812 c = snew(struct ssh_channel);
4815 if (x11_init(&c->u.x11.s, ssh->x11disp, c,
4816 NULL, -1, ssh->conf) != NULL) {
4817 logevent("Opening X11 forward connection failed");
4819 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4820 PKT_INT, remoteid, PKT_END);
4823 ("Opening X11 forward connection succeeded");
4824 c->remoteid = remoteid;
4825 c->halfopen = FALSE;
4826 c->localid = alloc_channel_id(ssh);
4828 c->pending_eof = FALSE;
4829 c->throttling_conn = 0;
4830 c->type = CHAN_X11; /* identify channel type */
4831 add234(ssh->channels, c);
4832 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4833 PKT_INT, c->remoteid, PKT_INT,
4834 c->localid, PKT_END);
4835 logevent("Opened X11 forward channel");
4840 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4842 /* Remote side is trying to open a channel to talk to our
4843 * agent. Give them back a local channel number. */
4844 struct ssh_channel *c;
4845 int remoteid = ssh_pkt_getuint32(pktin);
4847 /* Refuse if agent forwarding is disabled. */
4848 if (!ssh->agentfwd_enabled) {
4849 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4850 PKT_INT, remoteid, PKT_END);
4852 c = snew(struct ssh_channel);
4854 c->remoteid = remoteid;
4855 c->halfopen = FALSE;
4856 c->localid = alloc_channel_id(ssh);
4858 c->pending_eof = FALSE;
4859 c->throttling_conn = 0;
4860 c->type = CHAN_AGENT; /* identify channel type */
4861 c->u.a.lensofar = 0;
4862 c->u.a.message = NULL;
4863 c->u.a.outstanding_requests = 0;
4864 add234(ssh->channels, c);
4865 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4866 PKT_INT, c->remoteid, PKT_INT, c->localid,
4871 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4873 /* Remote side is trying to open a channel to talk to a
4874 * forwarded port. Give them back a local channel number. */
4875 struct ssh_rportfwd pf, *pfp;
4881 remoteid = ssh_pkt_getuint32(pktin);
4882 ssh_pkt_getstring(pktin, &host, &hostsize);
4883 port = ssh_pkt_getuint32(pktin);
4885 if (hostsize >= lenof(pf.dhost))
4886 hostsize = lenof(pf.dhost)-1;
4887 memcpy(pf.dhost, host, hostsize);
4888 pf.dhost[hostsize] = '\0';
4890 pfp = find234(ssh->rportfwds, &pf, NULL);
4893 logeventf(ssh, "Rejected remote port open request for %s:%d",
4895 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4896 PKT_INT, remoteid, PKT_END);
4898 struct ssh_channel *c = snew(struct ssh_channel);
4901 logeventf(ssh, "Received remote port open request for %s:%d",
4903 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4904 c, ssh->conf, pfp->pfrec->addressfamily);
4906 logeventf(ssh, "Port open failed: %s", e);
4908 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4909 PKT_INT, remoteid, PKT_END);
4911 c->remoteid = remoteid;
4912 c->halfopen = FALSE;
4913 c->localid = alloc_channel_id(ssh);
4915 c->pending_eof = FALSE;
4916 c->throttling_conn = 0;
4917 c->type = CHAN_SOCKDATA; /* identify channel type */
4918 add234(ssh->channels, c);
4919 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4920 PKT_INT, c->remoteid, PKT_INT,
4921 c->localid, PKT_END);
4922 logevent("Forwarded port opened successfully");
4927 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4929 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4930 unsigned int localid = ssh_pkt_getuint32(pktin);
4931 struct ssh_channel *c;
4933 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4934 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4935 c->remoteid = localid;
4936 c->halfopen = FALSE;
4937 c->type = CHAN_SOCKDATA;
4938 c->throttling_conn = 0;
4939 pfd_confirm(c->u.pfd.s);
4942 if (c && c->pending_eof) {
4944 * We have a pending close on this channel,
4945 * which we decided on before the server acked
4946 * the channel open. So now we know the
4947 * remoteid, we can close it again.
4949 ssh_channel_try_eof(c);
4953 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4955 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4956 struct ssh_channel *c;
4958 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4959 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4960 logevent("Forwarded connection refused by server");
4961 pfd_close(c->u.pfd.s);
4962 del234(ssh->channels, c);
4967 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4969 /* Remote side closes a channel. */
4970 unsigned i = ssh_pkt_getuint32(pktin);
4971 struct ssh_channel *c;
4972 c = find234(ssh->channels, &i, ssh_channelfind);
4973 if (c && !c->halfopen) {
4975 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE &&
4976 !(c->closes & CLOSES_RCVD_EOF)) {
4978 * Received CHANNEL_CLOSE, which we translate into
4981 int send_close = FALSE;
4983 c->closes |= CLOSES_RCVD_EOF;
4988 x11_send_eof(c->u.x11.s);
4994 pfd_send_eof(c->u.pfd.s);
5003 if (send_close && !(c->closes & CLOSES_SENT_EOF)) {
5004 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
5006 c->closes |= CLOSES_SENT_EOF;
5010 if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION &&
5011 !(c->closes & CLOSES_RCVD_CLOSE)) {
5013 if (!(c->closes & CLOSES_SENT_EOF)) {
5014 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
5015 " for which we never sent CHANNEL_CLOSE\n", i));
5018 c->closes |= CLOSES_RCVD_CLOSE;
5021 if (!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) &&
5022 !(c->closes & CLOSES_SENT_CLOSE)) {
5023 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION,
5024 PKT_INT, c->remoteid, PKT_END);
5025 c->closes |= CLOSES_SENT_CLOSE;
5028 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes))
5029 ssh_channel_destroy(c);
5031 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5032 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
5033 "_CONFIRMATION", c ? "half-open" : "nonexistent",
5038 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
5040 /* Data sent down one of our channels. */
5041 int i = ssh_pkt_getuint32(pktin);
5044 struct ssh_channel *c;
5046 ssh_pkt_getstring(pktin, &p, &len);
5048 c = find234(ssh->channels, &i, ssh_channelfind);
5053 bufsize = x11_send(c->u.x11.s, p, len);
5056 bufsize = pfd_send(c->u.pfd.s, p, len);
5059 /* Data for an agent message. Buffer it. */
5061 if (c->u.a.lensofar < 4) {
5062 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
5063 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
5067 c->u.a.lensofar += l;
5069 if (c->u.a.lensofar == 4) {
5071 4 + GET_32BIT(c->u.a.msglen);
5072 c->u.a.message = snewn(c->u.a.totallen,
5074 memcpy(c->u.a.message, c->u.a.msglen, 4);
5076 if (c->u.a.lensofar >= 4 && len > 0) {
5078 min(c->u.a.totallen - c->u.a.lensofar,
5080 memcpy(c->u.a.message + c->u.a.lensofar, p,
5084 c->u.a.lensofar += l;
5086 if (c->u.a.lensofar == c->u.a.totallen) {
5089 c->u.a.outstanding_requests++;
5090 if (agent_query(c->u.a.message,
5093 ssh_agentf_callback, c))
5094 ssh_agentf_callback(c, reply, replylen);
5095 sfree(c->u.a.message);
5096 c->u.a.lensofar = 0;
5099 bufsize = 0; /* agent channels never back up */
5102 if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) {
5103 c->throttling_conn = 1;
5104 ssh_throttle_conn(ssh, +1);
5109 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
5111 ssh->exitcode = ssh_pkt_getuint32(pktin);
5112 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
5113 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
5115 * In case `helpful' firewalls or proxies tack
5116 * extra human-readable text on the end of the
5117 * session which we might mistake for another
5118 * encrypted packet, we close the session once
5119 * we've sent EXIT_CONFIRMATION.
5121 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
5124 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5125 static void ssh1_send_ttymode(void *data, char *mode, char *val)
5127 struct Packet *pktout = (struct Packet *)data;
5129 unsigned int arg = 0;
5130 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
5131 if (i == lenof(ssh_ttymodes)) return;
5132 switch (ssh_ttymodes[i].type) {
5134 arg = ssh_tty_parse_specchar(val);
5137 arg = ssh_tty_parse_boolean(val);
5140 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
5141 ssh2_pkt_addbyte(pktout, arg);
5145 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
5146 struct Packet *pktin)
5148 crBegin(ssh->do_ssh1_connection_crstate);
5150 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
5151 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
5152 ssh1_smsg_stdout_stderr_data;
5154 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
5155 ssh1_msg_channel_open_confirmation;
5156 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
5157 ssh1_msg_channel_open_failure;
5158 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
5159 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
5160 ssh1_msg_channel_close;
5161 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
5162 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
5164 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) {
5165 logevent("Requesting agent forwarding");
5166 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
5170 if (pktin->type != SSH1_SMSG_SUCCESS
5171 && pktin->type != SSH1_SMSG_FAILURE) {
5172 bombout(("Protocol confusion"));
5174 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5175 logevent("Agent forwarding refused");
5177 logevent("Agent forwarding enabled");
5178 ssh->agentfwd_enabled = TRUE;
5179 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
5183 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
5184 (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
5185 conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) {
5186 logevent("Requesting X11 forwarding");
5188 * Note that while we blank the X authentication data here, we don't
5189 * take any special action to blank the start of an X11 channel,
5190 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5191 * without having session blanking enabled is likely to leak your
5192 * cookie into the log.
5194 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
5195 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5196 PKT_STR, ssh->x11disp->remoteauthprotoname,
5198 PKT_STR, ssh->x11disp->remoteauthdatastring,
5200 PKT_INT, ssh->x11disp->screennum,
5203 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
5204 PKT_STR, ssh->x11disp->remoteauthprotoname,
5206 PKT_STR, ssh->x11disp->remoteauthdatastring,
5213 if (pktin->type != SSH1_SMSG_SUCCESS
5214 && pktin->type != SSH1_SMSG_FAILURE) {
5215 bombout(("Protocol confusion"));
5217 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5218 logevent("X11 forwarding refused");
5220 logevent("X11 forwarding enabled");
5221 ssh->X11_fwd_enabled = TRUE;
5222 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
5226 ssh_setup_portfwd(ssh, ssh->conf);
5227 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
5229 if (!conf_get_int(ssh->conf, CONF_nopty)) {
5231 /* Unpick the terminal-speed string. */
5232 /* XXX perhaps we should allow no speeds to be sent. */
5233 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
5234 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
5235 /* Send the pty request. */
5236 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
5237 ssh_pkt_addstring(pkt, conf_get_str(ssh->conf, CONF_termtype));
5238 ssh_pkt_adduint32(pkt, ssh->term_height);
5239 ssh_pkt_adduint32(pkt, ssh->term_width);
5240 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
5241 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
5242 parse_ttymodes(ssh, ssh1_send_ttymode, (void *)pkt);
5243 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
5244 ssh_pkt_adduint32(pkt, ssh->ispeed);
5245 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
5246 ssh_pkt_adduint32(pkt, ssh->ospeed);
5247 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
5249 ssh->state = SSH_STATE_INTERMED;
5253 if (pktin->type != SSH1_SMSG_SUCCESS
5254 && pktin->type != SSH1_SMSG_FAILURE) {
5255 bombout(("Protocol confusion"));
5257 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5258 c_write_str(ssh, "Server refused to allocate pty\r\n");
5259 ssh->editing = ssh->echoing = 1;
5261 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5262 ssh->ospeed, ssh->ispeed);
5263 ssh->got_pty = TRUE;
5266 ssh->editing = ssh->echoing = 1;
5269 if (conf_get_int(ssh->conf, CONF_compression)) {
5270 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
5274 if (pktin->type != SSH1_SMSG_SUCCESS
5275 && pktin->type != SSH1_SMSG_FAILURE) {
5276 bombout(("Protocol confusion"));
5278 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5279 c_write_str(ssh, "Server refused to compress\r\n");
5281 logevent("Started compression");
5282 ssh->v1_compressing = TRUE;
5283 ssh->cs_comp_ctx = zlib_compress_init();
5284 logevent("Initialised zlib (RFC1950) compression");
5285 ssh->sc_comp_ctx = zlib_decompress_init();
5286 logevent("Initialised zlib (RFC1950) decompression");
5290 * Start the shell or command.
5292 * Special case: if the first-choice command is an SSH-2
5293 * subsystem (hence not usable here) and the second choice
5294 * exists, we fall straight back to that.
5297 char *cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
5299 if (conf_get_int(ssh->conf, CONF_ssh_subsys) &&
5300 conf_get_str(ssh->conf, CONF_remote_cmd2)) {
5301 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
5302 ssh->fallback_cmd = TRUE;
5305 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
5307 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
5308 logevent("Started session");
5311 ssh->state = SSH_STATE_SESSION;
5312 if (ssh->size_needed)
5313 ssh_size(ssh, ssh->term_width, ssh->term_height);
5314 if (ssh->eof_needed)
5315 ssh_special(ssh, TS_EOF);
5318 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5320 ssh->channels = newtree234(ssh_channelcmp);
5324 * By this point, most incoming packets are already being
5325 * handled by the dispatch table, and we need only pay
5326 * attention to the unusual ones.
5331 if (pktin->type == SSH1_SMSG_SUCCESS) {
5332 /* may be from EXEC_SHELL on some servers */
5333 } else if (pktin->type == SSH1_SMSG_FAILURE) {
5334 /* may be from EXEC_SHELL on some servers
5335 * if no pty is available or in other odd cases. Ignore */
5337 bombout(("Strange packet received: type %d", pktin->type));
5342 int len = min(inlen, 512);
5343 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
5344 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
5345 PKTT_OTHER, PKT_END);
5356 * Handle the top-level SSH-2 protocol.
5358 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
5363 ssh_pkt_getstring(pktin, &msg, &msglen);
5364 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5367 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5369 /* log reason code in disconnect message */
5373 ssh_pkt_getstring(pktin, &msg, &msglen);
5374 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5377 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5379 /* Do nothing, because we're ignoring it! Duhh. */
5382 static void ssh1_protocol_setup(Ssh ssh)
5387 * Most messages are handled by the coroutines.
5389 for (i = 0; i < 256; i++)
5390 ssh->packet_dispatch[i] = NULL;
5393 * These special message types we install handlers for.
5395 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5396 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5397 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5400 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5401 struct Packet *pktin)
5403 unsigned char *in=(unsigned char*)vin;
5404 if (ssh->state == SSH_STATE_CLOSED)
5407 if (pktin && ssh->packet_dispatch[pktin->type]) {
5408 ssh->packet_dispatch[pktin->type](ssh, pktin);
5412 if (!ssh->protocol_initial_phase_done) {
5413 if (do_ssh1_login(ssh, in, inlen, pktin))
5414 ssh->protocol_initial_phase_done = TRUE;
5419 do_ssh1_connection(ssh, in, inlen, pktin);
5423 * Utility routine for decoding comma-separated strings in KEXINIT.
5425 static int in_commasep_string(char *needle, char *haystack, int haylen)
5428 if (!needle || !haystack) /* protect against null pointers */
5430 needlen = strlen(needle);
5433 * Is it at the start of the string?
5435 if (haylen >= needlen && /* haystack is long enough */
5436 !memcmp(needle, haystack, needlen) && /* initial match */
5437 (haylen == needlen || haystack[needlen] == ',')
5438 /* either , or EOS follows */
5442 * If not, search for the next comma and resume after that.
5443 * If no comma found, terminate.
5445 while (haylen > 0 && *haystack != ',')
5446 haylen--, haystack++;
5449 haylen--, haystack++; /* skip over comma itself */
5454 * Similar routine for checking whether we have the first string in a list.
5456 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5459 if (!needle || !haystack) /* protect against null pointers */
5461 needlen = strlen(needle);
5463 * Is it at the start of the string?
5465 if (haylen >= needlen && /* haystack is long enough */
5466 !memcmp(needle, haystack, needlen) && /* initial match */
5467 (haylen == needlen || haystack[needlen] == ',')
5468 /* either , or EOS follows */
5476 * SSH-2 key creation method.
5477 * (Currently assumes 2 lots of any hash are sufficient to generate
5478 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5480 #define SSH2_MKKEY_ITERS (2)
5481 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5482 unsigned char *keyspace)
5484 const struct ssh_hash *h = ssh->kex->hash;
5486 /* First hlen bytes. */
5488 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5489 hash_mpint(h, s, K);
5490 h->bytes(s, H, h->hlen);
5491 h->bytes(s, &chr, 1);
5492 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5493 h->final(s, keyspace);
5494 /* Next hlen bytes. */
5496 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5497 hash_mpint(h, s, K);
5498 h->bytes(s, H, h->hlen);
5499 h->bytes(s, keyspace, h->hlen);
5500 h->final(s, keyspace + h->hlen);
5504 * Handle the SSH-2 transport layer.
5506 static void do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5507 struct Packet *pktin)
5509 unsigned char *in = (unsigned char *)vin;
5510 struct do_ssh2_transport_state {
5512 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5513 Bignum p, g, e, f, K;
5516 int kex_init_value, kex_reply_value;
5517 const struct ssh_mac **maclist;
5519 const struct ssh2_cipher *cscipher_tobe;
5520 const struct ssh2_cipher *sccipher_tobe;
5521 const struct ssh_mac *csmac_tobe;
5522 const struct ssh_mac *scmac_tobe;
5523 const struct ssh_compress *cscomp_tobe;
5524 const struct ssh_compress *sccomp_tobe;
5525 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5526 int hostkeylen, siglen, rsakeylen;
5527 void *hkey; /* actual host key */
5528 void *rsakey; /* for RSA kex */
5529 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5530 int n_preferred_kex;
5531 const struct ssh_kexes *preferred_kex[KEX_MAX];
5532 int n_preferred_ciphers;
5533 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5534 const struct ssh_compress *preferred_comp;
5535 int userauth_succeeded; /* for delayed compression */
5536 int pending_compression;
5537 int got_session_id, activated_authconn;
5538 struct Packet *pktout;
5543 crState(do_ssh2_transport_state);
5547 s->cscipher_tobe = s->sccipher_tobe = NULL;
5548 s->csmac_tobe = s->scmac_tobe = NULL;
5549 s->cscomp_tobe = s->sccomp_tobe = NULL;
5551 s->got_session_id = s->activated_authconn = FALSE;
5552 s->userauth_succeeded = FALSE;
5553 s->pending_compression = FALSE;
5556 * Be prepared to work around the buggy MAC problem.
5558 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5559 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5561 s->maclist = macs, s->nmacs = lenof(macs);
5564 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5566 int i, j, k, commalist_started;
5569 * Set up the preferred key exchange. (NULL => warn below here)
5571 s->n_preferred_kex = 0;
5572 for (i = 0; i < KEX_MAX; i++) {
5573 switch (conf_get_int_int(ssh->conf, CONF_ssh_kexlist, i)) {
5575 s->preferred_kex[s->n_preferred_kex++] =
5576 &ssh_diffiehellman_gex;
5579 s->preferred_kex[s->n_preferred_kex++] =
5580 &ssh_diffiehellman_group14;
5583 s->preferred_kex[s->n_preferred_kex++] =
5584 &ssh_diffiehellman_group1;
5587 s->preferred_kex[s->n_preferred_kex++] =
5591 /* Flag for later. Don't bother if it's the last in
5593 if (i < KEX_MAX - 1) {
5594 s->preferred_kex[s->n_preferred_kex++] = NULL;
5601 * Set up the preferred ciphers. (NULL => warn below here)
5603 s->n_preferred_ciphers = 0;
5604 for (i = 0; i < CIPHER_MAX; i++) {
5605 switch (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i)) {
5606 case CIPHER_BLOWFISH:
5607 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5610 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc)) {
5611 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5615 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5618 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5620 case CIPHER_ARCFOUR:
5621 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5624 /* Flag for later. Don't bother if it's the last in
5626 if (i < CIPHER_MAX - 1) {
5627 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5634 * Set up preferred compression.
5636 if (conf_get_int(ssh->conf, CONF_compression))
5637 s->preferred_comp = &ssh_zlib;
5639 s->preferred_comp = &ssh_comp_none;
5642 * Enable queueing of outgoing auth- or connection-layer
5643 * packets while we are in the middle of a key exchange.
5645 ssh->queueing = TRUE;
5648 * Flag that KEX is in progress.
5650 ssh->kex_in_progress = TRUE;
5653 * Construct and send our key exchange packet.
5655 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5656 for (i = 0; i < 16; i++)
5657 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5658 /* List key exchange algorithms. */
5659 ssh2_pkt_addstring_start(s->pktout);
5660 commalist_started = 0;
5661 for (i = 0; i < s->n_preferred_kex; i++) {
5662 const struct ssh_kexes *k = s->preferred_kex[i];
5663 if (!k) continue; /* warning flag */
5664 for (j = 0; j < k->nkexes; j++) {
5665 if (commalist_started)
5666 ssh2_pkt_addstring_str(s->pktout, ",");
5667 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5668 commalist_started = 1;
5671 /* List server host key algorithms. */
5672 if (!s->got_session_id) {
5674 * In the first key exchange, we list all the algorithms
5675 * we're prepared to cope with.
5677 ssh2_pkt_addstring_start(s->pktout);
5678 for (i = 0; i < lenof(hostkey_algs); i++) {
5679 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5680 if (i < lenof(hostkey_algs) - 1)
5681 ssh2_pkt_addstring_str(s->pktout, ",");
5685 * In subsequent key exchanges, we list only the kex
5686 * algorithm that was selected in the first key exchange,
5687 * so that we keep getting the same host key and hence
5688 * don't have to interrupt the user's session to ask for
5692 ssh2_pkt_addstring(s->pktout, ssh->hostkey->name);
5694 /* List encryption algorithms (client->server then server->client). */
5695 for (k = 0; k < 2; k++) {
5696 ssh2_pkt_addstring_start(s->pktout);
5697 commalist_started = 0;
5698 for (i = 0; i < s->n_preferred_ciphers; i++) {
5699 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5700 if (!c) continue; /* warning flag */
5701 for (j = 0; j < c->nciphers; j++) {
5702 if (commalist_started)
5703 ssh2_pkt_addstring_str(s->pktout, ",");
5704 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5705 commalist_started = 1;
5709 /* List MAC algorithms (client->server then server->client). */
5710 for (j = 0; j < 2; j++) {
5711 ssh2_pkt_addstring_start(s->pktout);
5712 for (i = 0; i < s->nmacs; i++) {
5713 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5714 if (i < s->nmacs - 1)
5715 ssh2_pkt_addstring_str(s->pktout, ",");
5718 /* List client->server compression algorithms,
5719 * then server->client compression algorithms. (We use the
5720 * same set twice.) */
5721 for (j = 0; j < 2; j++) {
5722 ssh2_pkt_addstring_start(s->pktout);
5723 assert(lenof(compressions) > 1);
5724 /* Prefer non-delayed versions */
5725 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5726 /* We don't even list delayed versions of algorithms until
5727 * they're allowed to be used, to avoid a race. See the end of
5729 if (s->userauth_succeeded && s->preferred_comp->delayed_name) {
5730 ssh2_pkt_addstring_str(s->pktout, ",");
5731 ssh2_pkt_addstring_str(s->pktout,
5732 s->preferred_comp->delayed_name);
5734 for (i = 0; i < lenof(compressions); i++) {
5735 const struct ssh_compress *c = compressions[i];
5736 if (c != s->preferred_comp) {
5737 ssh2_pkt_addstring_str(s->pktout, ",");
5738 ssh2_pkt_addstring_str(s->pktout, c->name);
5739 if (s->userauth_succeeded && c->delayed_name) {
5740 ssh2_pkt_addstring_str(s->pktout, ",");
5741 ssh2_pkt_addstring_str(s->pktout, c->delayed_name);
5746 /* List client->server languages. Empty list. */
5747 ssh2_pkt_addstring_start(s->pktout);
5748 /* List server->client languages. Empty list. */
5749 ssh2_pkt_addstring_start(s->pktout);
5750 /* First KEX packet does _not_ follow, because we're not that brave. */
5751 ssh2_pkt_addbool(s->pktout, FALSE);
5753 ssh2_pkt_adduint32(s->pktout, 0);
5756 s->our_kexinitlen = s->pktout->length - 5;
5757 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5758 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5760 ssh2_pkt_send_noqueue(ssh, s->pktout);
5763 crWaitUntilV(pktin);
5766 * Now examine the other side's KEXINIT to see what we're up
5770 char *str, *preferred;
5773 if (pktin->type != SSH2_MSG_KEXINIT) {
5774 bombout(("expected key exchange packet from server"));
5778 ssh->hostkey = NULL;
5779 s->cscipher_tobe = NULL;
5780 s->sccipher_tobe = NULL;
5781 s->csmac_tobe = NULL;
5782 s->scmac_tobe = NULL;
5783 s->cscomp_tobe = NULL;
5784 s->sccomp_tobe = NULL;
5785 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5787 pktin->savedpos += 16; /* skip garbage cookie */
5788 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5791 for (i = 0; i < s->n_preferred_kex; i++) {
5792 const struct ssh_kexes *k = s->preferred_kex[i];
5796 for (j = 0; j < k->nkexes; j++) {
5797 if (!preferred) preferred = k->list[j]->name;
5798 if (in_commasep_string(k->list[j]->name, str, len)) {
5799 ssh->kex = k->list[j];
5808 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5809 str ? str : "(null)"));
5813 * Note that the server's guess is considered wrong if it doesn't match
5814 * the first algorithm in our list, even if it's still the algorithm
5817 s->guessok = first_in_commasep_string(preferred, str, len);
5818 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5819 for (i = 0; i < lenof(hostkey_algs); i++) {
5820 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5821 ssh->hostkey = hostkey_algs[i];
5825 if (!ssh->hostkey) {
5826 bombout(("Couldn't agree a host key algorithm (available: %s)",
5827 str ? str : "(null)"));
5831 s->guessok = s->guessok &&
5832 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5833 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5834 for (i = 0; i < s->n_preferred_ciphers; i++) {
5835 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5837 s->warn_cscipher = TRUE;
5839 for (j = 0; j < c->nciphers; j++) {
5840 if (in_commasep_string(c->list[j]->name, str, len)) {
5841 s->cscipher_tobe = c->list[j];
5846 if (s->cscipher_tobe)
5849 if (!s->cscipher_tobe) {
5850 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5851 str ? str : "(null)"));
5855 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5856 for (i = 0; i < s->n_preferred_ciphers; i++) {
5857 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5859 s->warn_sccipher = TRUE;
5861 for (j = 0; j < c->nciphers; j++) {
5862 if (in_commasep_string(c->list[j]->name, str, len)) {
5863 s->sccipher_tobe = c->list[j];
5868 if (s->sccipher_tobe)
5871 if (!s->sccipher_tobe) {
5872 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5873 str ? str : "(null)"));
5877 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5878 for (i = 0; i < s->nmacs; i++) {
5879 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5880 s->csmac_tobe = s->maclist[i];
5884 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5885 for (i = 0; i < s->nmacs; i++) {
5886 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5887 s->scmac_tobe = s->maclist[i];
5891 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5892 for (i = 0; i < lenof(compressions) + 1; i++) {
5893 const struct ssh_compress *c =
5894 i == 0 ? s->preferred_comp : compressions[i - 1];
5895 if (in_commasep_string(c->name, str, len)) {
5898 } else if (in_commasep_string(c->delayed_name, str, len)) {
5899 if (s->userauth_succeeded) {
5903 s->pending_compression = TRUE; /* try this later */
5907 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5908 for (i = 0; i < lenof(compressions) + 1; i++) {
5909 const struct ssh_compress *c =
5910 i == 0 ? s->preferred_comp : compressions[i - 1];
5911 if (in_commasep_string(c->name, str, len)) {
5914 } else if (in_commasep_string(c->delayed_name, str, len)) {
5915 if (s->userauth_succeeded) {
5919 s->pending_compression = TRUE; /* try this later */
5923 if (s->pending_compression) {
5924 logevent("Server supports delayed compression; "
5925 "will try this later");
5927 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5928 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5929 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5931 ssh->exhash = ssh->kex->hash->init();
5932 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5933 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5934 hash_string(ssh->kex->hash, ssh->exhash,
5935 s->our_kexinit, s->our_kexinitlen);
5936 sfree(s->our_kexinit);
5937 if (pktin->length > 5)
5938 hash_string(ssh->kex->hash, ssh->exhash,
5939 pktin->data + 5, pktin->length - 5);
5942 ssh_set_frozen(ssh, 1);
5943 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5945 ssh_dialog_callback, ssh);
5946 if (s->dlgret < 0) {
5950 bombout(("Unexpected data from server while"
5951 " waiting for user response"));
5954 } while (pktin || inlen > 0);
5955 s->dlgret = ssh->user_response;
5957 ssh_set_frozen(ssh, 0);
5958 if (s->dlgret == 0) {
5959 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5965 if (s->warn_cscipher) {
5966 ssh_set_frozen(ssh, 1);
5967 s->dlgret = askalg(ssh->frontend,
5968 "client-to-server cipher",
5969 s->cscipher_tobe->name,
5970 ssh_dialog_callback, ssh);
5971 if (s->dlgret < 0) {
5975 bombout(("Unexpected data from server while"
5976 " waiting for user response"));
5979 } while (pktin || inlen > 0);
5980 s->dlgret = ssh->user_response;
5982 ssh_set_frozen(ssh, 0);
5983 if (s->dlgret == 0) {
5984 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5990 if (s->warn_sccipher) {
5991 ssh_set_frozen(ssh, 1);
5992 s->dlgret = askalg(ssh->frontend,
5993 "server-to-client cipher",
5994 s->sccipher_tobe->name,
5995 ssh_dialog_callback, ssh);
5996 if (s->dlgret < 0) {
6000 bombout(("Unexpected data from server while"
6001 " waiting for user response"));
6004 } while (pktin || inlen > 0);
6005 s->dlgret = ssh->user_response;
6007 ssh_set_frozen(ssh, 0);
6008 if (s->dlgret == 0) {
6009 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
6015 if (s->ignorepkt) /* first_kex_packet_follows */
6016 crWaitUntilV(pktin); /* Ignore packet */
6019 if (ssh->kex->main_type == KEXTYPE_DH) {
6021 * Work out the number of bits of key we will need from the
6022 * key exchange. We start with the maximum key length of
6028 csbits = s->cscipher_tobe->keylen;
6029 scbits = s->sccipher_tobe->keylen;
6030 s->nbits = (csbits > scbits ? csbits : scbits);
6032 /* The keys only have hlen-bit entropy, since they're based on
6033 * a hash. So cap the key size at hlen bits. */
6034 if (s->nbits > ssh->kex->hash->hlen * 8)
6035 s->nbits = ssh->kex->hash->hlen * 8;
6038 * If we're doing Diffie-Hellman group exchange, start by
6039 * requesting a group.
6041 if (!ssh->kex->pdata) {
6042 logevent("Doing Diffie-Hellman group exchange");
6043 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
6045 * Work out how big a DH group we will need to allow that
6048 s->pbits = 512 << ((s->nbits - 1) / 64);
6049 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
6050 ssh2_pkt_adduint32(s->pktout, s->pbits);
6051 ssh2_pkt_send_noqueue(ssh, s->pktout);
6053 crWaitUntilV(pktin);
6054 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
6055 bombout(("expected key exchange group packet from server"));
6058 s->p = ssh2_pkt_getmp(pktin);
6059 s->g = ssh2_pkt_getmp(pktin);
6060 if (!s->p || !s->g) {
6061 bombout(("unable to read mp-ints from incoming group packet"));
6064 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
6065 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
6066 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
6068 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
6069 ssh->kex_ctx = dh_setup_group(ssh->kex);
6070 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
6071 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
6072 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
6073 ssh->kex->groupname);
6076 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
6077 ssh->kex->hash->text_name);
6079 * Now generate and send e for Diffie-Hellman.
6081 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
6082 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
6083 s->pktout = ssh2_pkt_init(s->kex_init_value);
6084 ssh2_pkt_addmp(s->pktout, s->e);
6085 ssh2_pkt_send_noqueue(ssh, s->pktout);
6087 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
6088 crWaitUntilV(pktin);
6089 if (pktin->type != s->kex_reply_value) {
6090 bombout(("expected key exchange reply packet from server"));
6093 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
6094 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6095 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6096 s->f = ssh2_pkt_getmp(pktin);
6098 bombout(("unable to parse key exchange reply packet"));
6101 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6103 s->K = dh_find_K(ssh->kex_ctx, s->f);
6105 /* We assume everything from now on will be quick, and it might
6106 * involve user interaction. */
6107 set_busy_status(ssh->frontend, BUSY_NOT);
6109 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
6110 if (!ssh->kex->pdata) {
6111 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
6112 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
6113 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
6115 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
6116 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
6118 dh_cleanup(ssh->kex_ctx);
6120 if (!ssh->kex->pdata) {
6125 logeventf(ssh, "Doing RSA key exchange with hash %s",
6126 ssh->kex->hash->text_name);
6127 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
6129 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6132 crWaitUntilV(pktin);
6133 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
6134 bombout(("expected RSA public key packet from server"));
6138 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
6139 hash_string(ssh->kex->hash, ssh->exhash,
6140 s->hostkeydata, s->hostkeylen);
6141 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
6145 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
6146 s->rsakeydata = snewn(s->rsakeylen, char);
6147 memcpy(s->rsakeydata, keydata, s->rsakeylen);
6150 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
6152 sfree(s->rsakeydata);
6153 bombout(("unable to parse RSA public key from server"));
6157 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
6160 * Next, set up a shared secret K, of precisely KLEN -
6161 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6162 * RSA key modulus and HLEN is the bit length of the hash
6166 int klen = ssh_rsakex_klen(s->rsakey);
6167 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
6169 unsigned char *kstr1, *kstr2, *outstr;
6170 int kstr1len, kstr2len, outstrlen;
6172 s->K = bn_power_2(nbits - 1);
6174 for (i = 0; i < nbits; i++) {
6176 byte = random_byte();
6178 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
6182 * Encode this as an mpint.
6184 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
6185 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
6186 PUT_32BIT(kstr2, kstr1len);
6187 memcpy(kstr2 + 4, kstr1, kstr1len);
6190 * Encrypt it with the given RSA key.
6192 outstrlen = (klen + 7) / 8;
6193 outstr = snewn(outstrlen, unsigned char);
6194 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
6195 outstr, outstrlen, s->rsakey);
6198 * And send it off in a return packet.
6200 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
6201 ssh2_pkt_addstring_start(s->pktout);
6202 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
6203 ssh2_pkt_send_noqueue(ssh, s->pktout);
6205 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
6212 ssh_rsakex_freekey(s->rsakey);
6214 crWaitUntilV(pktin);
6215 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
6216 sfree(s->rsakeydata);
6217 bombout(("expected signature packet from server"));
6221 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
6223 sfree(s->rsakeydata);
6226 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
6227 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
6228 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
6230 ssh->kex_ctx = NULL;
6233 debug(("Exchange hash is:\n"));
6234 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
6238 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
6239 (char *)s->exchange_hash,
6240 ssh->kex->hash->hlen)) {
6241 bombout(("Server's host key did not match the signature supplied"));
6245 s->keystr = ssh->hostkey->fmtkey(s->hkey);
6246 if (!s->got_session_id) {
6248 * Authenticate remote host: verify host key. (We've already
6249 * checked the signature of the exchange hash.)
6251 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
6252 ssh_set_frozen(ssh, 1);
6253 s->dlgret = verify_ssh_host_key(ssh->frontend,
6254 ssh->savedhost, ssh->savedport,
6255 ssh->hostkey->keytype, s->keystr,
6257 ssh_dialog_callback, ssh);
6258 if (s->dlgret < 0) {
6262 bombout(("Unexpected data from server while waiting"
6263 " for user host key response"));
6266 } while (pktin || inlen > 0);
6267 s->dlgret = ssh->user_response;
6269 ssh_set_frozen(ssh, 0);
6270 if (s->dlgret == 0) {
6271 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
6275 logevent("Host key fingerprint is:");
6276 logevent(s->fingerprint);
6277 sfree(s->fingerprint);
6279 * Save this host key, to check against the one presented in
6280 * subsequent rekeys.
6282 ssh->hostkey_str = s->keystr;
6285 * In a rekey, we never present an interactive host key
6286 * verification request to the user. Instead, we simply
6287 * enforce that the key we're seeing this time is identical to
6288 * the one we saw before.
6290 if (strcmp(ssh->hostkey_str, s->keystr)) {
6291 bombout(("Host key was different in repeat key exchange"));
6296 ssh->hostkey->freekey(s->hkey);
6299 * The exchange hash from the very first key exchange is also
6300 * the session id, used in session key construction and
6303 if (!s->got_session_id) {
6304 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
6305 memcpy(ssh->v2_session_id, s->exchange_hash,
6306 sizeof(s->exchange_hash));
6307 ssh->v2_session_id_len = ssh->kex->hash->hlen;
6308 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
6309 s->got_session_id = TRUE;
6313 * Send SSH2_MSG_NEWKEYS.
6315 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
6316 ssh2_pkt_send_noqueue(ssh, s->pktout);
6317 ssh->outgoing_data_size = 0; /* start counting from here */
6320 * We've sent client NEWKEYS, so create and initialise
6321 * client-to-server session keys.
6323 if (ssh->cs_cipher_ctx)
6324 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
6325 ssh->cscipher = s->cscipher_tobe;
6326 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
6328 if (ssh->cs_mac_ctx)
6329 ssh->csmac->free_context(ssh->cs_mac_ctx);
6330 ssh->csmac = s->csmac_tobe;
6331 ssh->cs_mac_ctx = ssh->csmac->make_context();
6333 if (ssh->cs_comp_ctx)
6334 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
6335 ssh->cscomp = s->cscomp_tobe;
6336 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
6339 * Set IVs on client-to-server keys. Here we use the exchange
6340 * hash from the _first_ key exchange.
6343 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6344 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6345 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
6346 assert((ssh->cscipher->keylen+7) / 8 <=
6347 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6348 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
6349 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
6350 assert(ssh->cscipher->blksize <=
6351 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6352 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
6353 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
6354 assert(ssh->csmac->len <=
6355 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6356 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
6357 smemclr(keyspace, sizeof(keyspace));
6360 logeventf(ssh, "Initialised %.200s client->server encryption",
6361 ssh->cscipher->text_name);
6362 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
6363 ssh->csmac->text_name);
6364 if (ssh->cscomp->text_name)
6365 logeventf(ssh, "Initialised %s compression",
6366 ssh->cscomp->text_name);
6369 * Now our end of the key exchange is complete, we can send all
6370 * our queued higher-layer packets.
6372 ssh->queueing = FALSE;
6373 ssh2_pkt_queuesend(ssh);
6376 * Expect SSH2_MSG_NEWKEYS from server.
6378 crWaitUntilV(pktin);
6379 if (pktin->type != SSH2_MSG_NEWKEYS) {
6380 bombout(("expected new-keys packet from server"));
6383 ssh->incoming_data_size = 0; /* start counting from here */
6386 * We've seen server NEWKEYS, so create and initialise
6387 * server-to-client session keys.
6389 if (ssh->sc_cipher_ctx)
6390 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
6391 ssh->sccipher = s->sccipher_tobe;
6392 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
6394 if (ssh->sc_mac_ctx)
6395 ssh->scmac->free_context(ssh->sc_mac_ctx);
6396 ssh->scmac = s->scmac_tobe;
6397 ssh->sc_mac_ctx = ssh->scmac->make_context();
6399 if (ssh->sc_comp_ctx)
6400 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
6401 ssh->sccomp = s->sccomp_tobe;
6402 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
6405 * Set IVs on server-to-client keys. Here we use the exchange
6406 * hash from the _first_ key exchange.
6409 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
6410 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6411 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
6412 assert((ssh->sccipher->keylen+7) / 8 <=
6413 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6414 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
6415 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
6416 assert(ssh->sccipher->blksize <=
6417 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6418 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6419 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6420 assert(ssh->scmac->len <=
6421 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6422 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6423 smemclr(keyspace, sizeof(keyspace));
6425 logeventf(ssh, "Initialised %.200s server->client encryption",
6426 ssh->sccipher->text_name);
6427 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6428 ssh->scmac->text_name);
6429 if (ssh->sccomp->text_name)
6430 logeventf(ssh, "Initialised %s decompression",
6431 ssh->sccomp->text_name);
6434 * Free shared secret.
6439 * Key exchange is over. Loop straight back round if we have a
6440 * deferred rekey reason.
6442 if (ssh->deferred_rekey_reason) {
6443 logevent(ssh->deferred_rekey_reason);
6445 ssh->deferred_rekey_reason = NULL;
6446 goto begin_key_exchange;
6450 * Otherwise, schedule a timer for our next rekey.
6452 ssh->kex_in_progress = FALSE;
6453 ssh->last_rekey = GETTICKCOUNT();
6454 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0)
6455 ssh->next_rekey = schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6459 * Now we're encrypting. Begin returning 1 to the protocol main
6460 * function so that other things can run on top of the
6461 * transport. If we ever see a KEXINIT, we must go back to the
6464 * We _also_ go back to the start if we see pktin==NULL and
6465 * inlen negative, because this is a special signal meaning
6466 * `initiate client-driven rekey', and `in' contains a message
6467 * giving the reason for the rekey.
6469 * inlen==-1 means always initiate a rekey;
6470 * inlen==-2 means that userauth has completed successfully and
6471 * we should consider rekeying (for delayed compression).
6473 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6474 (!pktin && inlen < 0))) {
6476 if (!ssh->protocol_initial_phase_done) {
6477 ssh->protocol_initial_phase_done = TRUE;
6479 * Allow authconn to initialise itself.
6481 do_ssh2_authconn(ssh, NULL, 0, NULL);
6486 logevent("Server initiated key re-exchange");
6490 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6491 * delayed compression, if it's available.
6493 * draft-miller-secsh-compression-delayed-00 says that you
6494 * negotiate delayed compression in the first key exchange, and
6495 * both sides start compressing when the server has sent
6496 * USERAUTH_SUCCESS. This has a race condition -- the server
6497 * can't know when the client has seen it, and thus which incoming
6498 * packets it should treat as compressed.
6500 * Instead, we do the initial key exchange without offering the
6501 * delayed methods, but note if the server offers them; when we
6502 * get here, if a delayed method was available that was higher
6503 * on our list than what we got, we initiate a rekey in which we
6504 * _do_ list the delayed methods (and hopefully get it as a
6505 * result). Subsequent rekeys will do the same.
6507 assert(!s->userauth_succeeded); /* should only happen once */
6508 s->userauth_succeeded = TRUE;
6509 if (!s->pending_compression)
6510 /* Can't see any point rekeying. */
6511 goto wait_for_rekey; /* this is utterly horrid */
6512 /* else fall through to rekey... */
6513 s->pending_compression = FALSE;
6516 * Now we've decided to rekey.
6518 * Special case: if the server bug is set that doesn't
6519 * allow rekeying, we give a different log message and
6520 * continue waiting. (If such a server _initiates_ a rekey,
6521 * we process it anyway!)
6523 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6524 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6526 /* Reset the counters, so that at least this message doesn't
6527 * hit the event log _too_ often. */
6528 ssh->outgoing_data_size = 0;
6529 ssh->incoming_data_size = 0;
6530 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0) {
6532 schedule_timer(conf_get_int(ssh->conf, CONF_ssh_rekey_time)*60*TICKSPERSEC,
6535 goto wait_for_rekey; /* this is still utterly horrid */
6537 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6540 goto begin_key_exchange;
6546 * Add data to an SSH-2 channel output buffer.
6548 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6551 bufchain_add(&c->v.v2.outbuffer, buf, len);
6555 * Attempt to send data on an SSH-2 channel.
6557 static int ssh2_try_send(struct ssh_channel *c)
6560 struct Packet *pktout;
6563 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6566 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6567 if ((unsigned)len > c->v.v2.remwindow)
6568 len = c->v.v2.remwindow;
6569 if ((unsigned)len > c->v.v2.remmaxpkt)
6570 len = c->v.v2.remmaxpkt;
6571 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6572 ssh2_pkt_adduint32(pktout, c->remoteid);
6573 ssh2_pkt_addstring_start(pktout);
6574 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6575 ssh2_pkt_addstring_data(pktout, data, len);
6576 end_log_omission(ssh, pktout);
6577 ssh2_pkt_send(ssh, pktout);
6578 bufchain_consume(&c->v.v2.outbuffer, len);
6579 c->v.v2.remwindow -= len;
6583 * After having sent as much data as we can, return the amount
6586 ret = bufchain_size(&c->v.v2.outbuffer);
6589 * And if there's no data pending but we need to send an EOF, send
6592 if (!ret && c->pending_eof)
6593 ssh_channel_try_eof(c);
6598 static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c)
6601 if (c->closes & CLOSES_SENT_EOF)
6602 return; /* don't send on channels we've EOFed */
6603 bufsize = ssh2_try_send(c);
6606 case CHAN_MAINSESSION:
6607 /* stdin need not receive an unthrottle
6608 * notification since it will be polled */
6611 x11_unthrottle(c->u.x11.s);
6614 /* agent sockets are request/response and need no
6615 * buffer management */
6618 pfd_unthrottle(c->u.pfd.s);
6625 * Set up most of a new ssh_channel for SSH-2.
6627 static void ssh2_channel_init(struct ssh_channel *c)
6630 c->localid = alloc_channel_id(ssh);
6632 c->pending_eof = FALSE;
6633 c->throttling_conn = FALSE;
6634 c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin =
6635 conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
6636 c->v.v2.chanreq_head = NULL;
6637 c->v.v2.throttle_state = UNTHROTTLED;
6638 bufchain_init(&c->v.v2.outbuffer);
6642 * Construct the common parts of a CHANNEL_OPEN.
6644 static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, char *type)
6646 struct Packet *pktout;
6648 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6649 ssh2_pkt_addstring(pktout, type);
6650 ssh2_pkt_adduint32(pktout, c->localid);
6651 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
6652 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6657 * CHANNEL_FAILURE doesn't come with any indication of what message
6658 * caused it, so we have to keep track of the outstanding
6659 * CHANNEL_REQUESTs ourselves.
6661 static void ssh2_queue_chanreq_handler(struct ssh_channel *c,
6662 cchandler_fn_t handler, void *ctx)
6664 struct outstanding_channel_request *ocr =
6665 snew(struct outstanding_channel_request);
6667 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6668 ocr->handler = handler;
6671 if (!c->v.v2.chanreq_head)
6672 c->v.v2.chanreq_head = ocr;
6674 c->v.v2.chanreq_tail->next = ocr;
6675 c->v.v2.chanreq_tail = ocr;
6679 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6680 * NULL then a reply will be requested and the handler will be called
6681 * when it arrives. The returned packet is ready to have any
6682 * request-specific data added and be sent. Note that if a handler is
6683 * provided, it's essential that the request actually be sent.
6685 * The handler will usually be passed the response packet in pktin.
6686 * If pktin is NULL, this means that no reply will ever be forthcoming
6687 * (e.g. because the entire connection is being destroyed) and the
6688 * handler should free any storage it's holding.
6690 static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type,
6691 cchandler_fn_t handler, void *ctx)
6693 struct Packet *pktout;
6695 assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
6696 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6697 ssh2_pkt_adduint32(pktout, c->remoteid);
6698 ssh2_pkt_addstring(pktout, type);
6699 ssh2_pkt_addbool(pktout, handler != NULL);
6700 if (handler != NULL)
6701 ssh2_queue_chanreq_handler(c, handler, ctx);
6706 * Potentially enlarge the window on an SSH-2 channel.
6708 static void ssh2_handle_winadj_response(struct ssh_channel *, struct Packet *,
6710 static void ssh2_set_window(struct ssh_channel *c, int newwin)
6715 * Never send WINDOW_ADJUST for a channel that the remote side has
6716 * already sent EOF on; there's no point, since it won't be
6717 * sending any more data anyway. Ditto if _we've_ already sent
6720 if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
6724 * If the remote end has a habit of ignoring maxpkt, limit the
6725 * window so that it has no choice (assuming it doesn't ignore the
6728 if ((ssh->remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
6729 newwin = OUR_V2_MAXPKT;
6732 * Only send a WINDOW_ADJUST if there's significantly more window
6733 * available than the other end thinks there is. This saves us
6734 * sending a WINDOW_ADJUST for every character in a shell session.
6736 * "Significant" is arbitrarily defined as half the window size.
6738 if (newwin / 2 >= c->v.v2.locwindow) {
6739 struct Packet *pktout;
6743 * In order to keep track of how much window the client
6744 * actually has available, we'd like it to acknowledge each
6745 * WINDOW_ADJUST. We can't do that directly, so we accompany
6746 * it with a CHANNEL_REQUEST that has to be acknowledged.
6748 * This is only necessary if we're opening the window wide.
6749 * If we're not, then throughput is being constrained by
6750 * something other than the maximum window size anyway.
6752 if (newwin == c->v.v2.locmaxwin &&
6753 !(ssh->remote_bugs & BUG_CHOKES_ON_WINADJ)) {
6754 up = snew(unsigned);
6755 *up = newwin - c->v.v2.locwindow;
6756 pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
6757 ssh2_handle_winadj_response, up);
6758 ssh2_pkt_send(ssh, pktout);
6760 if (c->v.v2.throttle_state != UNTHROTTLED)
6761 c->v.v2.throttle_state = UNTHROTTLING;
6763 /* Pretend the WINDOW_ADJUST was acked immediately. */
6764 c->v.v2.remlocwin = newwin;
6765 c->v.v2.throttle_state = THROTTLED;
6767 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6768 ssh2_pkt_adduint32(pktout, c->remoteid);
6769 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6770 ssh2_pkt_send(ssh, pktout);
6771 c->v.v2.locwindow = newwin;
6776 * Find the channel associated with a message. If there's no channel,
6777 * or it's not properly open, make a noise about it and return NULL.
6779 static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin)
6781 unsigned localid = ssh_pkt_getuint32(pktin);
6782 struct ssh_channel *c;
6784 c = find234(ssh->channels, &localid, ssh_channelfind);
6786 (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION &&
6787 pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) {
6788 char *buf = dupprintf("Received %s for %s channel %u",
6789 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
6791 c ? "half-open" : "nonexistent", localid);
6792 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6799 static void ssh2_handle_winadj_response(struct ssh_channel *c,
6800 struct Packet *pktin, void *ctx)
6802 unsigned *sizep = ctx;
6805 * Winadj responses should always be failures. However, at least
6806 * one server ("boks_sshd") is known to return SUCCESS for channel
6807 * requests it's never heard of, such as "winadj@putty". Raised
6808 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6809 * life, we don't worry about what kind of response we got.
6812 c->v.v2.remlocwin += *sizep;
6815 * winadj messages are only sent when the window is fully open, so
6816 * if we get an ack of one, we know any pending unthrottle is
6819 if (c->v.v2.throttle_state == UNTHROTTLING)
6820 c->v.v2.throttle_state = UNTHROTTLED;
6823 static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin)
6825 struct ssh_channel *c = ssh2_channel_msg(ssh, pktin);
6826 struct outstanding_channel_request *ocr;
6829 ocr = c->v.v2.chanreq_head;
6831 ssh2_msg_unexpected(ssh, pktin);
6834 ocr->handler(c, pktin, ocr->ctx);
6835 c->v.v2.chanreq_head = ocr->next;
6838 * We may now initiate channel-closing procedures, if that
6839 * CHANNEL_REQUEST was the last thing outstanding before we send
6842 ssh2_channel_check_close(c);
6845 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6847 struct ssh_channel *c;
6848 c = ssh2_channel_msg(ssh, pktin);
6851 if (!(c->closes & CLOSES_SENT_EOF)) {
6852 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6853 ssh2_try_send_and_unthrottle(ssh, c);
6857 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6861 struct ssh_channel *c;
6862 c = ssh2_channel_msg(ssh, pktin);
6865 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6866 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6867 return; /* extended but not stderr */
6868 ssh_pkt_getstring(pktin, &data, &length);
6871 c->v.v2.locwindow -= length;
6872 c->v.v2.remlocwin -= length;
6874 case CHAN_MAINSESSION:
6876 from_backend(ssh->frontend, pktin->type ==
6877 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6881 bufsize = x11_send(c->u.x11.s, data, length);
6884 bufsize = pfd_send(c->u.pfd.s, data, length);
6887 while (length > 0) {
6888 if (c->u.a.lensofar < 4) {
6889 unsigned int l = min(4 - c->u.a.lensofar,
6891 memcpy(c->u.a.msglen + c->u.a.lensofar,
6895 c->u.a.lensofar += l;
6897 if (c->u.a.lensofar == 4) {
6899 4 + GET_32BIT(c->u.a.msglen);
6900 c->u.a.message = snewn(c->u.a.totallen,
6902 memcpy(c->u.a.message, c->u.a.msglen, 4);
6904 if (c->u.a.lensofar >= 4 && length > 0) {
6906 min(c->u.a.totallen - c->u.a.lensofar,
6908 memcpy(c->u.a.message + c->u.a.lensofar,
6912 c->u.a.lensofar += l;
6914 if (c->u.a.lensofar == c->u.a.totallen) {
6917 c->u.a.outstanding_requests++;
6918 if (agent_query(c->u.a.message,
6921 ssh_agentf_callback, c))
6922 ssh_agentf_callback(c, reply, replylen);
6923 sfree(c->u.a.message);
6924 c->u.a.message = NULL;
6925 c->u.a.lensofar = 0;
6932 * If it looks like the remote end hit the end of its window,
6933 * and we didn't want it to do that, think about using a
6936 if (c->v.v2.remlocwin <= 0 && c->v.v2.throttle_state == UNTHROTTLED &&
6937 c->v.v2.locmaxwin < 0x40000000)
6938 c->v.v2.locmaxwin += OUR_V2_WINSIZE;
6940 * If we are not buffering too much data,
6941 * enlarge the window again at the remote side.
6942 * If we are buffering too much, we may still
6943 * need to adjust the window if the server's
6946 ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ?
6947 c->v.v2.locmaxwin - bufsize : 0);
6949 * If we're either buffering way too much data, or if we're
6950 * buffering anything at all and we're in "simple" mode,
6951 * throttle the whole channel.
6953 if ((bufsize > c->v.v2.locmaxwin ||
6954 (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) &&
6955 !c->throttling_conn) {
6956 c->throttling_conn = 1;
6957 ssh_throttle_conn(ssh, +1);
6962 static void ssh_channel_destroy(struct ssh_channel *c)
6967 case CHAN_MAINSESSION:
6968 ssh->mainchan = NULL;
6969 update_specials_menu(ssh->frontend);
6972 if (c->u.x11.s != NULL)
6973 x11_close(c->u.x11.s);
6974 logevent("Forwarded X11 connection terminated");
6977 sfree(c->u.a.message);
6980 if (c->u.pfd.s != NULL)
6981 pfd_close(c->u.pfd.s);
6982 logevent("Forwarded port closed");
6986 del234(ssh->channels, c);
6987 if (ssh->version == 2) {
6988 bufchain_clear(&c->v.v2.outbuffer);
6989 assert(c->v.v2.chanreq_head == NULL);
6994 * See if that was the last channel left open.
6995 * (This is only our termination condition if we're
6996 * not running in -N mode.)
6998 if (ssh->version == 2 &&
6999 !conf_get_int(ssh->conf, CONF_ssh_no_shell) &&
7000 count234(ssh->channels) == 0) {
7002 * We used to send SSH_MSG_DISCONNECT here,
7003 * because I'd believed that _every_ conforming
7004 * SSH-2 connection had to end with a disconnect
7005 * being sent by at least one side; apparently
7006 * I was wrong and it's perfectly OK to
7007 * unceremoniously slam the connection shut
7008 * when you're done, and indeed OpenSSH feels
7009 * this is more polite than sending a
7010 * DISCONNECT. So now we don't.
7012 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
7016 static void ssh2_channel_check_close(struct ssh_channel *c)
7019 struct Packet *pktout;
7021 if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) ||
7022 c->type == CHAN_ZOMBIE) &&
7023 !c->v.v2.chanreq_head &&
7024 !(c->closes & CLOSES_SENT_CLOSE)) {
7026 * We have both sent and received EOF (or the channel is a
7027 * zombie), and we have no outstanding channel requests, which
7028 * means the channel is in final wind-up. But we haven't sent
7029 * CLOSE, so let's do so now.
7031 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
7032 ssh2_pkt_adduint32(pktout, c->remoteid);
7033 ssh2_pkt_send(ssh, pktout);
7034 c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
7037 if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
7038 assert(c->v.v2.chanreq_head == NULL);
7040 * We have both sent and received CLOSE, which means we're
7041 * completely done with the channel.
7043 ssh_channel_destroy(c);
7047 static void ssh2_channel_got_eof(struct ssh_channel *c)
7049 if (c->closes & CLOSES_RCVD_EOF)
7050 return; /* already seen EOF */
7051 c->closes |= CLOSES_RCVD_EOF;
7053 if (c->type == CHAN_X11) {
7054 x11_send_eof(c->u.x11.s);
7055 } else if (c->type == CHAN_AGENT) {
7056 if (c->u.a.outstanding_requests == 0) {
7057 /* Manufacture an outgoing EOF in response to the incoming one. */
7058 sshfwd_write_eof(c);
7060 } else if (c->type == CHAN_SOCKDATA) {
7061 pfd_send_eof(c->u.pfd.s);
7062 } else if (c->type == CHAN_MAINSESSION) {
7065 if (!ssh->sent_console_eof &&
7066 (from_backend_eof(ssh->frontend) || ssh->got_pty)) {
7068 * Either from_backend_eof told us that the front end
7069 * wants us to close the outgoing side of the connection
7070 * as soon as we see EOF from the far end, or else we've
7071 * unilaterally decided to do that because we've allocated
7072 * a remote pty and hence EOF isn't a particularly
7073 * meaningful concept.
7075 sshfwd_write_eof(c);
7077 ssh->sent_console_eof = TRUE;
7080 ssh2_channel_check_close(c);
7083 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
7085 struct ssh_channel *c;
7087 c = ssh2_channel_msg(ssh, pktin);
7090 ssh2_channel_got_eof(c);
7093 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
7095 struct ssh_channel *c;
7097 c = ssh2_channel_msg(ssh, pktin);
7102 * When we receive CLOSE on a channel, we assume it comes with an
7103 * implied EOF if we haven't seen EOF yet.
7105 ssh2_channel_got_eof(c);
7108 * And we also send an outgoing EOF, if we haven't already, on the
7109 * assumption that CLOSE is a pretty forceful announcement that
7110 * the remote side is doing away with the entire channel. (If it
7111 * had wanted to send us EOF and continue receiving data from us,
7112 * it would have just sent CHANNEL_EOF.)
7114 if (!(c->closes & CLOSES_SENT_EOF)) {
7116 * Make sure we don't read any more from whatever our local
7117 * data source is for this channel.
7120 case CHAN_MAINSESSION:
7121 ssh->send_ok = 0; /* stop trying to read from stdin */
7124 x11_override_throttle(c->u.x11.s, 1);
7127 pfd_override_throttle(c->u.pfd.s, 1);
7132 * Abandon any buffered data we still wanted to send to this
7133 * channel. Receiving a CHANNEL_CLOSE is an indication that
7134 * the server really wants to get on and _destroy_ this
7135 * channel, and it isn't going to send us any further
7136 * WINDOW_ADJUSTs to permit us to send pending stuff.
7138 bufchain_clear(&c->v.v2.outbuffer);
7141 * Send outgoing EOF.
7143 sshfwd_write_eof(c);
7147 * Now process the actual close.
7149 if (!(c->closes & CLOSES_RCVD_CLOSE)) {
7150 c->closes |= CLOSES_RCVD_CLOSE;
7151 ssh2_channel_check_close(c);
7155 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
7157 struct ssh_channel *c;
7159 c = ssh2_channel_msg(ssh, pktin);
7162 if (c->type != CHAN_SOCKDATA_DORMANT)
7163 return; /* dunno why they're confirming this */
7164 c->remoteid = ssh_pkt_getuint32(pktin);
7165 c->halfopen = FALSE;
7166 c->type = CHAN_SOCKDATA;
7167 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7168 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7170 pfd_confirm(c->u.pfd.s);
7172 ssh_channel_try_eof(c);
7175 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
7177 static const char *const reasons[] = {
7178 "<unknown reason code>",
7179 "Administratively prohibited",
7181 "Unknown channel type",
7182 "Resource shortage",
7184 unsigned reason_code;
7185 char *reason_string;
7187 struct ssh_channel *c;
7188 c = ssh2_channel_msg(ssh, pktin);
7191 if (c->type != CHAN_SOCKDATA_DORMANT)
7192 return; /* dunno why they're failing this */
7194 reason_code = ssh_pkt_getuint32(pktin);
7195 if (reason_code >= lenof(reasons))
7196 reason_code = 0; /* ensure reasons[reason_code] in range */
7197 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
7198 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
7199 reasons[reason_code], reason_length, reason_string);
7201 pfd_close(c->u.pfd.s);
7203 del234(ssh->channels, c);
7207 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
7210 int typelen, want_reply;
7211 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
7212 struct ssh_channel *c;
7213 struct Packet *pktout;
7215 c = ssh2_channel_msg(ssh, pktin);
7218 ssh_pkt_getstring(pktin, &type, &typelen);
7219 want_reply = ssh2_pkt_getbool(pktin);
7222 * Having got the channel number, we now look at
7223 * the request type string to see if it's something
7226 if (c == ssh->mainchan) {
7228 * We recognise "exit-status" and "exit-signal" on
7229 * the primary channel.
7231 if (typelen == 11 &&
7232 !memcmp(type, "exit-status", 11)) {
7234 ssh->exitcode = ssh_pkt_getuint32(pktin);
7235 logeventf(ssh, "Server sent command exit status %d",
7237 reply = SSH2_MSG_CHANNEL_SUCCESS;
7239 } else if (typelen == 11 &&
7240 !memcmp(type, "exit-signal", 11)) {
7242 int is_plausible = TRUE, is_int = FALSE;
7243 char *fmt_sig = "", *fmt_msg = "";
7245 int msglen = 0, core = FALSE;
7246 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7247 * provide an `int' for the signal, despite its
7248 * having been a `string' in the drafts of RFC 4254 since at
7249 * least 2001. (Fixed in session.c 1.147.) Try to
7250 * infer which we can safely parse it as. */
7252 unsigned char *p = pktin->body +
7254 long len = pktin->length - pktin->savedpos;
7255 unsigned long num = GET_32BIT(p); /* what is it? */
7256 /* If it's 0, it hardly matters; assume string */
7260 int maybe_int = FALSE, maybe_str = FALSE;
7261 #define CHECK_HYPOTHESIS(offset, result) \
7264 int q = toint(offset); \
7265 if (q >= 0 && q+4 <= len) { \
7266 q = toint(q + 4 + GET_32BIT(p+q)); \
7267 if (q >= 0 && q+4 <= len && \
7268 ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \
7273 CHECK_HYPOTHESIS(4+1, maybe_int);
7274 CHECK_HYPOTHESIS(4+num+1, maybe_str);
7275 #undef CHECK_HYPOTHESIS
7276 if (maybe_int && !maybe_str)
7278 else if (!maybe_int && maybe_str)
7281 /* Crikey. Either or neither. Panic. */
7282 is_plausible = FALSE;
7285 ssh->exitcode = 128; /* means `unknown signal' */
7288 /* Old non-standard OpenSSH. */
7289 int signum = ssh_pkt_getuint32(pktin);
7290 fmt_sig = dupprintf(" %d", signum);
7291 ssh->exitcode = 128 + signum;
7293 /* As per RFC 4254. */
7296 ssh_pkt_getstring(pktin, &sig, &siglen);
7297 /* Signal name isn't supposed to be blank, but
7298 * let's cope gracefully if it is. */
7300 fmt_sig = dupprintf(" \"%.*s\"",
7305 * Really hideous method of translating the
7306 * signal description back into a locally
7307 * meaningful number.
7312 #define TRANSLATE_SIGNAL(s) \
7313 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7314 ssh->exitcode = 128 + SIG ## s
7316 TRANSLATE_SIGNAL(ABRT);
7319 TRANSLATE_SIGNAL(ALRM);
7322 TRANSLATE_SIGNAL(FPE);
7325 TRANSLATE_SIGNAL(HUP);
7328 TRANSLATE_SIGNAL(ILL);
7331 TRANSLATE_SIGNAL(INT);
7334 TRANSLATE_SIGNAL(KILL);
7337 TRANSLATE_SIGNAL(PIPE);
7340 TRANSLATE_SIGNAL(QUIT);
7343 TRANSLATE_SIGNAL(SEGV);
7346 TRANSLATE_SIGNAL(TERM);
7349 TRANSLATE_SIGNAL(USR1);
7352 TRANSLATE_SIGNAL(USR2);
7354 #undef TRANSLATE_SIGNAL
7356 ssh->exitcode = 128;
7358 core = ssh2_pkt_getbool(pktin);
7359 ssh_pkt_getstring(pktin, &msg, &msglen);
7361 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
7363 /* ignore lang tag */
7364 } /* else don't attempt to parse */
7365 logeventf(ssh, "Server exited on signal%s%s%s",
7366 fmt_sig, core ? " (core dumped)" : "",
7368 if (*fmt_sig) sfree(fmt_sig);
7369 if (*fmt_msg) sfree(fmt_msg);
7370 reply = SSH2_MSG_CHANNEL_SUCCESS;
7375 * This is a channel request we don't know
7376 * about, so we now either ignore the request
7377 * or respond with CHANNEL_FAILURE, depending
7380 reply = SSH2_MSG_CHANNEL_FAILURE;
7383 pktout = ssh2_pkt_init(reply);
7384 ssh2_pkt_adduint32(pktout, c->remoteid);
7385 ssh2_pkt_send(ssh, pktout);
7389 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
7392 int typelen, want_reply;
7393 struct Packet *pktout;
7395 ssh_pkt_getstring(pktin, &type, &typelen);
7396 want_reply = ssh2_pkt_getbool(pktin);
7399 * We currently don't support any global requests
7400 * at all, so we either ignore the request or
7401 * respond with REQUEST_FAILURE, depending on
7405 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
7406 ssh2_pkt_send(ssh, pktout);
7410 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
7418 struct ssh_channel *c;
7419 unsigned remid, winsize, pktsize;
7420 struct Packet *pktout;
7422 ssh_pkt_getstring(pktin, &type, &typelen);
7423 c = snew(struct ssh_channel);
7426 remid = ssh_pkt_getuint32(pktin);
7427 winsize = ssh_pkt_getuint32(pktin);
7428 pktsize = ssh_pkt_getuint32(pktin);
7430 if (typelen == 3 && !memcmp(type, "x11", 3)) {
7434 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7435 addrstr = snewn(peeraddrlen+1, char);
7436 memcpy(addrstr, peeraddr, peeraddrlen);
7437 addrstr[peeraddrlen] = '\0';
7438 peerport = ssh_pkt_getuint32(pktin);
7440 logeventf(ssh, "Received X11 connect request from %s:%d",
7443 if (!ssh->X11_fwd_enabled)
7444 error = "X11 forwarding is not enabled";
7445 else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c,
7446 addrstr, peerport, ssh->conf)) != NULL) {
7447 logeventf(ssh, "Local X11 connection failed: %s", x11err);
7448 error = "Unable to open an X11 connection";
7450 logevent("Opening X11 forward connection succeeded");
7455 } else if (typelen == 15 &&
7456 !memcmp(type, "forwarded-tcpip", 15)) {
7457 struct ssh_rportfwd pf, *realpf;
7460 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
7461 pf.sport = ssh_pkt_getuint32(pktin);
7462 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
7463 peerport = ssh_pkt_getuint32(pktin);
7464 realpf = find234(ssh->rportfwds, &pf, NULL);
7465 logeventf(ssh, "Received remote port %d open request "
7466 "from %s:%d", pf.sport, peeraddr, peerport);
7467 if (realpf == NULL) {
7468 error = "Remote port is not recognised";
7470 const char *e = pfd_newconnect(&c->u.pfd.s,
7474 realpf->pfrec->addressfamily);
7475 logeventf(ssh, "Attempting to forward remote port to "
7476 "%s:%d", realpf->dhost, realpf->dport);
7478 logeventf(ssh, "Port open failed: %s", e);
7479 error = "Port open failed";
7481 logevent("Forwarded port opened successfully");
7482 c->type = CHAN_SOCKDATA;
7485 } else if (typelen == 22 &&
7486 !memcmp(type, "auth-agent@openssh.com", 22)) {
7487 if (!ssh->agentfwd_enabled)
7488 error = "Agent forwarding is not enabled";
7490 c->type = CHAN_AGENT; /* identify channel type */
7491 c->u.a.lensofar = 0;
7492 c->u.a.message = NULL;
7493 c->u.a.outstanding_requests = 0;
7496 error = "Unsupported channel type requested";
7499 c->remoteid = remid;
7500 c->halfopen = FALSE;
7502 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
7503 ssh2_pkt_adduint32(pktout, c->remoteid);
7504 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
7505 ssh2_pkt_addstring(pktout, error);
7506 ssh2_pkt_addstring(pktout, "en"); /* language tag */
7507 ssh2_pkt_send(ssh, pktout);
7508 logeventf(ssh, "Rejected channel open: %s", error);
7511 ssh2_channel_init(c);
7512 c->v.v2.remwindow = winsize;
7513 c->v.v2.remmaxpkt = pktsize;
7514 add234(ssh->channels, c);
7515 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
7516 ssh2_pkt_adduint32(pktout, c->remoteid);
7517 ssh2_pkt_adduint32(pktout, c->localid);
7518 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
7519 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
7520 ssh2_pkt_send(ssh, pktout);
7525 * Buffer banner messages for later display at some convenient point,
7526 * if we're going to display them.
7528 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
7530 /* Arbitrary limit to prevent unbounded inflation of buffer */
7531 if (conf_get_int(ssh->conf, CONF_ssh_show_banner) &&
7532 bufchain_size(&ssh->banner) <= 131072) {
7533 char *banner = NULL;
7535 ssh_pkt_getstring(pktin, &banner, &size);
7537 bufchain_add(&ssh->banner, banner, size);
7541 /* Helper function to deal with sending tty modes for "pty-req" */
7542 static void ssh2_send_ttymode(void *data, char *mode, char *val)
7544 struct Packet *pktout = (struct Packet *)data;
7546 unsigned int arg = 0;
7547 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
7548 if (i == lenof(ssh_ttymodes)) return;
7549 switch (ssh_ttymodes[i].type) {
7551 arg = ssh_tty_parse_specchar(val);
7554 arg = ssh_tty_parse_boolean(val);
7557 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
7558 ssh2_pkt_adduint32(pktout, arg);
7561 static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin,
7564 struct ssh2_setup_x11_state {
7568 struct Packet *pktout;
7569 crStateP(ssh2_setup_x11_state, ctx);
7573 logevent("Requesting X11 forwarding");
7574 pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req",
7576 ssh2_pkt_addbool(pktout, 0); /* many connections */
7577 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname);
7579 * Note that while we blank the X authentication data here, we don't
7580 * take any special action to blank the start of an X11 channel,
7581 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7582 * without having session blanking enabled is likely to leak your
7583 * cookie into the log.
7585 dont_log_password(ssh, pktout, PKTLOG_BLANK);
7586 ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring);
7587 end_log_omission(ssh, pktout);
7588 ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum);
7589 ssh2_pkt_send(ssh, pktout);
7591 /* Wait to be called back with either a response packet, or NULL
7592 * meaning clean up and free our data */
7596 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7597 logevent("X11 forwarding enabled");
7598 ssh->X11_fwd_enabled = TRUE;
7600 logevent("X11 forwarding refused");
7606 static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin,
7609 struct ssh2_setup_agent_state {
7613 struct Packet *pktout;
7614 crStateP(ssh2_setup_agent_state, ctx);
7618 logevent("Requesting OpenSSH-style agent forwarding");
7619 pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com",
7620 ssh2_setup_agent, s);
7621 ssh2_pkt_send(ssh, pktout);
7623 /* Wait to be called back with either a response packet, or NULL
7624 * meaning clean up and free our data */
7628 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7629 logevent("Agent forwarding enabled");
7630 ssh->agentfwd_enabled = TRUE;
7632 logevent("Agent forwarding refused");
7638 static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin,
7641 struct ssh2_setup_pty_state {
7645 struct Packet *pktout;
7646 crStateP(ssh2_setup_pty_state, ctx);
7650 /* Unpick the terminal-speed string. */
7651 /* XXX perhaps we should allow no speeds to be sent. */
7652 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7653 sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed);
7654 /* Build the pty request. */
7655 pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req",
7657 ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype));
7658 ssh2_pkt_adduint32(pktout, ssh->term_width);
7659 ssh2_pkt_adduint32(pktout, ssh->term_height);
7660 ssh2_pkt_adduint32(pktout, 0); /* pixel width */
7661 ssh2_pkt_adduint32(pktout, 0); /* pixel height */
7662 ssh2_pkt_addstring_start(pktout);
7663 parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout);
7664 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED);
7665 ssh2_pkt_adduint32(pktout, ssh->ispeed);
7666 ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED);
7667 ssh2_pkt_adduint32(pktout, ssh->ospeed);
7668 ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */
7669 ssh2_pkt_send(ssh, pktout);
7670 ssh->state = SSH_STATE_INTERMED;
7672 /* Wait to be called back with either a response packet, or NULL
7673 * meaning clean up and free our data */
7677 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) {
7678 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7679 ssh->ospeed, ssh->ispeed);
7680 ssh->got_pty = TRUE;
7682 c_write_str(ssh, "Server refused to allocate pty\r\n");
7683 ssh->editing = ssh->echoing = 1;
7690 static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin,
7693 struct ssh2_setup_env_state {
7695 int num_env, env_left, env_ok;
7698 struct Packet *pktout;
7699 crStateP(ssh2_setup_env_state, ctx);
7704 * Send environment variables.
7706 * Simplest thing here is to send all the requests at once, and
7707 * then wait for a whole bunch of successes or failures.
7713 for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key);
7715 val = conf_get_str_strs(ssh->conf, CONF_environmt, key, &key)) {
7716 pktout = ssh2_chanreq_init(ssh->mainchan, "env", ssh2_setup_env, s);
7717 ssh2_pkt_addstring(pktout, key);
7718 ssh2_pkt_addstring(pktout, val);
7719 ssh2_pkt_send(ssh, pktout);
7724 logeventf(ssh, "Sent %d environment variables", s->num_env);
7729 s->env_left = s->num_env;
7731 while (s->env_left > 0) {
7732 /* Wait to be called back with either a response packet,
7733 * or NULL meaning clean up and free our data */
7735 if (!pktin) goto out;
7736 if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS)
7741 if (s->env_ok == s->num_env) {
7742 logevent("All environment variables successfully set");
7743 } else if (s->env_ok == 0) {
7744 logevent("All environment variables refused");
7745 c_write_str(ssh, "Server refused to set environment variables\r\n");
7747 logeventf(ssh, "%d environment variables refused",
7748 s->num_env - s->env_ok);
7749 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7757 * Handle the SSH-2 userauth and connection layers.
7759 static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin)
7761 do_ssh2_authconn(ssh, NULL, 0, pktin);
7764 static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin,
7767 do_ssh2_authconn(c->ssh, NULL, 0, pktin);
7770 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
7771 struct Packet *pktin)
7773 struct do_ssh2_authconn_state {
7777 AUTH_TYPE_PUBLICKEY,
7778 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
7779 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
7781 AUTH_TYPE_GSSAPI, /* always QUIET */
7782 AUTH_TYPE_KEYBOARD_INTERACTIVE,
7783 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7785 int done_service_req;
7786 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
7787 int tried_pubkey_config, done_agent;
7792 int kbd_inter_refused;
7793 int we_are_in, userauth_success;
7794 prompts_t *cur_prompt;
7799 void *publickey_blob;
7800 int publickey_bloblen;
7801 int publickey_encrypted;
7802 char *publickey_algorithm;
7803 char *publickey_comment;
7804 unsigned char agent_request[5], *agent_response, *agentp;
7805 int agent_responselen;
7806 unsigned char *pkblob_in_agent;
7808 char *pkblob, *alg, *commentp;
7809 int pklen, alglen, commentlen;
7810 int siglen, retlen, len;
7811 char *q, *agentreq, *ret;
7813 struct Packet *pktout;
7816 struct ssh_gss_library *gsslib;
7817 Ssh_gss_ctx gss_ctx;
7818 Ssh_gss_buf gss_buf;
7819 Ssh_gss_buf gss_rcvtok, gss_sndtok;
7820 Ssh_gss_name gss_srv_name;
7821 Ssh_gss_stat gss_stat;
7824 crState(do_ssh2_authconn_state);
7828 /* Register as a handler for all the messages this coroutine handles. */
7829 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_authconn;
7830 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_authconn;
7831 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_authconn;
7832 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_authconn;
7833 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_authconn;
7834 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_authconn;
7835 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7836 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7837 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_authconn;
7838 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_authconn;
7839 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_authconn;
7840 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_authconn;
7841 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_authconn;
7842 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_authconn;
7843 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_authconn;
7844 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_authconn;
7845 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_authconn;
7846 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_authconn;
7847 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_authconn;
7848 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_authconn;
7850 s->done_service_req = FALSE;
7851 s->we_are_in = s->userauth_success = FALSE;
7853 s->tried_gssapi = FALSE;
7856 if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) {
7858 * Request userauth protocol, and await a response to it.
7860 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7861 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
7862 ssh2_pkt_send(ssh, s->pktout);
7863 crWaitUntilV(pktin);
7864 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
7865 s->done_service_req = TRUE;
7867 if (!s->done_service_req) {
7869 * Request connection protocol directly, without authentication.
7871 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
7872 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7873 ssh2_pkt_send(ssh, s->pktout);
7874 crWaitUntilV(pktin);
7875 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
7876 s->we_are_in = TRUE; /* no auth required */
7878 bombout(("Server refused service request"));
7883 /* Arrange to be able to deal with any BANNERs that come in.
7884 * (We do this now as packets may come in during the next bit.) */
7885 bufchain_init(&ssh->banner);
7886 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
7887 ssh2_msg_userauth_banner;
7890 * Misc one-time setup for authentication.
7892 s->publickey_blob = NULL;
7893 if (!s->we_are_in) {
7896 * Load the public half of any configured public key file
7899 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
7900 if (!filename_is_null(s->keyfile)) {
7902 logeventf(ssh, "Reading private key file \"%.150s\"",
7903 filename_to_str(s->keyfile));
7904 keytype = key_type(s->keyfile);
7905 if (keytype == SSH_KEYTYPE_SSH2) {
7908 ssh2_userkey_loadpub(s->keyfile,
7909 &s->publickey_algorithm,
7910 &s->publickey_bloblen,
7911 &s->publickey_comment, &error);
7912 if (s->publickey_blob) {
7913 s->publickey_encrypted =
7914 ssh2_userkey_encrypted(s->keyfile, NULL);
7917 logeventf(ssh, "Unable to load private key (%s)",
7919 msgbuf = dupprintf("Unable to load private key file "
7920 "\"%.150s\" (%s)\r\n",
7921 filename_to_str(s->keyfile),
7923 c_write_str(ssh, msgbuf);
7928 logeventf(ssh, "Unable to use this key file (%s)",
7929 key_type_to_str(keytype));
7930 msgbuf = dupprintf("Unable to use key file \"%.150s\""
7932 filename_to_str(s->keyfile),
7933 key_type_to_str(keytype));
7934 c_write_str(ssh, msgbuf);
7936 s->publickey_blob = NULL;
7941 * Find out about any keys Pageant has (but if there's a
7942 * public key configured, filter out all others).
7945 s->agent_response = NULL;
7946 s->pkblob_in_agent = NULL;
7947 if (conf_get_int(ssh->conf, CONF_tryagent) && agent_exists()) {
7951 logevent("Pageant is running. Requesting keys.");
7953 /* Request the keys held by the agent. */
7954 PUT_32BIT(s->agent_request, 1);
7955 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
7956 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
7957 ssh_agent_callback, ssh)) {
7961 bombout(("Unexpected data from server while"
7962 " waiting for agent response"));
7965 } while (pktin || inlen > 0);
7966 r = ssh->agent_response;
7967 s->agent_responselen = ssh->agent_response_len;
7969 s->agent_response = (unsigned char *) r;
7970 if (s->agent_response && s->agent_responselen >= 5 &&
7971 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
7974 p = s->agent_response + 5;
7975 s->nkeys = toint(GET_32BIT(p));
7978 * Vet the Pageant response to ensure that the key
7979 * count and blob lengths make sense.
7982 logeventf(ssh, "Pageant response contained a negative"
7983 " key count %d", s->nkeys);
7985 goto done_agent_query;
7987 unsigned char *q = p + 4;
7988 int lenleft = s->agent_responselen - 5 - 4;
7990 for (keyi = 0; keyi < s->nkeys; keyi++) {
7991 int bloblen, commentlen;
7993 logeventf(ssh, "Pageant response was truncated");
7995 goto done_agent_query;
7997 bloblen = toint(GET_32BIT(q));
7998 if (bloblen < 0 || bloblen > lenleft) {
7999 logeventf(ssh, "Pageant response was truncated");
8001 goto done_agent_query;
8003 lenleft -= 4 + bloblen;
8005 commentlen = toint(GET_32BIT(q));
8006 if (commentlen < 0 || commentlen > lenleft) {
8007 logeventf(ssh, "Pageant response was truncated");
8009 goto done_agent_query;
8011 lenleft -= 4 + commentlen;
8012 q += 4 + commentlen;
8017 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
8018 if (s->publickey_blob) {
8019 /* See if configured key is in agent. */
8020 for (keyi = 0; keyi < s->nkeys; keyi++) {
8021 s->pklen = toint(GET_32BIT(p));
8022 if (s->pklen == s->publickey_bloblen &&
8023 !memcmp(p+4, s->publickey_blob,
8024 s->publickey_bloblen)) {
8025 logeventf(ssh, "Pageant key #%d matches "
8026 "configured key file", keyi);
8028 s->pkblob_in_agent = p;
8032 p += toint(GET_32BIT(p)) + 4; /* comment */
8034 if (!s->pkblob_in_agent) {
8035 logevent("Configured key file not in Pageant");
8040 logevent("Failed to get reply from Pageant");
8048 * We repeat this whole loop, including the username prompt,
8049 * until we manage a successful authentication. If the user
8050 * types the wrong _password_, they can be sent back to the
8051 * beginning to try another username, if this is configured on.
8052 * (If they specify a username in the config, they are never
8053 * asked, even if they do give a wrong password.)
8055 * I think this best serves the needs of
8057 * - the people who have no configuration, no keys, and just
8058 * want to try repeated (username,password) pairs until they
8059 * type both correctly
8061 * - people who have keys and configuration but occasionally
8062 * need to fall back to passwords
8064 * - people with a key held in Pageant, who might not have
8065 * logged in to a particular machine before; so they want to
8066 * type a username, and then _either_ their key will be
8067 * accepted, _or_ they will type a password. If they mistype
8068 * the username they will want to be able to get back and
8071 s->got_username = FALSE;
8072 while (!s->we_are_in) {
8076 if (s->got_username && !conf_get_int(ssh->conf, CONF_change_username)) {
8078 * We got a username last time round this loop, and
8079 * with change_username turned off we don't try to get
8082 } else if ((ssh->username = get_remote_username(ssh->conf)) == NULL) {
8083 int ret; /* need not be kept over crReturn */
8084 s->cur_prompt = new_prompts(ssh->frontend);
8085 s->cur_prompt->to_server = TRUE;
8086 s->cur_prompt->name = dupstr("SSH login name");
8087 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE);
8088 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8091 crWaitUntilV(!pktin);
8092 ret = get_userpass_input(s->cur_prompt, in, inlen);
8097 * get_userpass_input() failed to get a username.
8100 free_prompts(s->cur_prompt);
8101 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
8104 ssh->username = dupstr(s->cur_prompt->prompts[0]->result);
8105 free_prompts(s->cur_prompt);
8108 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
8109 stuff = dupprintf("Using username \"%s\".\r\n", ssh->username);
8110 c_write_str(ssh, stuff);
8114 s->got_username = TRUE;
8117 * Send an authentication request using method "none": (a)
8118 * just in case it succeeds, and (b) so that we know what
8119 * authentication methods we can usefully try next.
8121 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8123 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8124 ssh2_pkt_addstring(s->pktout, ssh->username);
8125 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
8126 ssh2_pkt_addstring(s->pktout, "none"); /* method */
8127 ssh2_pkt_send(ssh, s->pktout);
8128 s->type = AUTH_TYPE_NONE;
8130 s->we_are_in = FALSE;
8132 s->tried_pubkey_config = FALSE;
8133 s->kbd_inter_refused = FALSE;
8135 /* Reset agent request state. */
8136 s->done_agent = FALSE;
8137 if (s->agent_response) {
8138 if (s->pkblob_in_agent) {
8139 s->agentp = s->pkblob_in_agent;
8141 s->agentp = s->agent_response + 5 + 4;
8147 char *methods = NULL;
8151 * Wait for the result of the last authentication request.
8154 crWaitUntilV(pktin);
8156 * Now is a convenient point to spew any banner material
8157 * that we've accumulated. (This should ensure that when
8158 * we exit the auth loop, we haven't any left to deal
8162 int size = bufchain_size(&ssh->banner);
8164 * Don't show the banner if we're operating in
8165 * non-verbose non-interactive mode. (It's probably
8166 * a script, which means nobody will read the
8167 * banner _anyway_, and moreover the printing of
8168 * the banner will screw up processing on the
8169 * output of (say) plink.)
8171 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
8172 char *banner = snewn(size, char);
8173 bufchain_fetch(&ssh->banner, banner, size);
8174 c_write_untrusted(ssh, banner, size);
8177 bufchain_clear(&ssh->banner);
8179 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
8180 logevent("Access granted");
8181 s->we_are_in = s->userauth_success = TRUE;
8185 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE && s->type != AUTH_TYPE_GSSAPI) {
8186 bombout(("Strange packet received during authentication: "
8187 "type %d", pktin->type));
8194 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8195 * we can look at the string in it and know what we can
8196 * helpfully try next.
8198 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
8199 ssh_pkt_getstring(pktin, &methods, &methlen);
8200 if (!ssh2_pkt_getbool(pktin)) {
8202 * We have received an unequivocal Access
8203 * Denied. This can translate to a variety of
8204 * messages, or no message at all.
8206 * For forms of authentication which are attempted
8207 * implicitly, by which I mean without printing
8208 * anything in the window indicating that we're
8209 * trying them, we should never print 'Access
8212 * If we do print a message saying that we're
8213 * attempting some kind of authentication, it's OK
8214 * to print a followup message saying it failed -
8215 * but the message may sometimes be more specific
8216 * than simply 'Access denied'.
8218 * Additionally, if we'd just tried password
8219 * authentication, we should break out of this
8220 * whole loop so as to go back to the username
8221 * prompt (iff we're configured to allow
8222 * username change attempts).
8224 if (s->type == AUTH_TYPE_NONE) {
8226 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
8227 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
8228 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
8229 c_write_str(ssh, "Server refused our key\r\n");
8230 logevent("Server refused our key");
8231 } else if (s->type == AUTH_TYPE_PUBLICKEY) {
8232 /* This _shouldn't_ happen except by a
8233 * protocol bug causing client and server to
8234 * disagree on what is a correct signature. */
8235 c_write_str(ssh, "Server refused public-key signature"
8236 " despite accepting key!\r\n");
8237 logevent("Server refused public-key signature"
8238 " despite accepting key!");
8239 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
8240 /* quiet, so no c_write */
8241 logevent("Server refused keyboard-interactive authentication");
8242 } else if (s->type==AUTH_TYPE_GSSAPI) {
8243 /* always quiet, so no c_write */
8244 /* also, the code down in the GSSAPI block has
8245 * already logged this in the Event Log */
8246 } else if (s->type == AUTH_TYPE_KEYBOARD_INTERACTIVE) {
8247 logevent("Keyboard-interactive authentication failed");
8248 c_write_str(ssh, "Access denied\r\n");
8250 assert(s->type == AUTH_TYPE_PASSWORD);
8251 logevent("Password authentication failed");
8252 c_write_str(ssh, "Access denied\r\n");
8254 if (conf_get_int(ssh->conf, CONF_change_username)) {
8255 /* XXX perhaps we should allow
8256 * keyboard-interactive to do this too? */
8257 s->we_are_in = FALSE;
8262 c_write_str(ssh, "Further authentication required\r\n");
8263 logevent("Further authentication required");
8267 in_commasep_string("publickey", methods, methlen);
8269 in_commasep_string("password", methods, methlen);
8270 s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) &&
8271 in_commasep_string("keyboard-interactive", methods, methlen);
8274 ssh->gsslibs = ssh_gss_setup(ssh->conf);
8275 s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) &&
8276 in_commasep_string("gssapi-with-mic", methods, methlen) &&
8277 ssh->gsslibs->nlibraries > 0;
8281 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8283 if (s->can_pubkey && !s->done_agent && s->nkeys) {
8286 * Attempt public-key authentication using a key from Pageant.
8289 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8291 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
8293 /* Unpack key from agent response */
8294 s->pklen = toint(GET_32BIT(s->agentp));
8296 s->pkblob = (char *)s->agentp;
8297 s->agentp += s->pklen;
8298 s->alglen = toint(GET_32BIT(s->pkblob));
8299 s->alg = s->pkblob + 4;
8300 s->commentlen = toint(GET_32BIT(s->agentp));
8302 s->commentp = (char *)s->agentp;
8303 s->agentp += s->commentlen;
8304 /* s->agentp now points at next key, if any */
8306 /* See if server will accept it */
8307 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8308 ssh2_pkt_addstring(s->pktout, ssh->username);
8309 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8310 /* service requested */
8311 ssh2_pkt_addstring(s->pktout, "publickey");
8313 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
8314 ssh2_pkt_addstring_start(s->pktout);
8315 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8316 ssh2_pkt_addstring_start(s->pktout);
8317 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8318 ssh2_pkt_send(ssh, s->pktout);
8319 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
8321 crWaitUntilV(pktin);
8322 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8324 /* Offer of key refused. */
8331 if (flags & FLAG_VERBOSE) {
8332 c_write_str(ssh, "Authenticating with "
8334 c_write(ssh, s->commentp, s->commentlen);
8335 c_write_str(ssh, "\" from agent\r\n");
8339 * Server is willing to accept the key.
8340 * Construct a SIGN_REQUEST.
8342 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8343 ssh2_pkt_addstring(s->pktout, ssh->username);
8344 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8345 /* service requested */
8346 ssh2_pkt_addstring(s->pktout, "publickey");
8348 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
8349 ssh2_pkt_addstring_start(s->pktout);
8350 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
8351 ssh2_pkt_addstring_start(s->pktout);
8352 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
8354 /* Ask agent for signature. */
8355 s->siglen = s->pktout->length - 5 + 4 +
8356 ssh->v2_session_id_len;
8357 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8359 s->len = 1; /* message type */
8360 s->len += 4 + s->pklen; /* key blob */
8361 s->len += 4 + s->siglen; /* data to sign */
8362 s->len += 4; /* flags */
8363 s->agentreq = snewn(4 + s->len, char);
8364 PUT_32BIT(s->agentreq, s->len);
8365 s->q = s->agentreq + 4;
8366 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
8367 PUT_32BIT(s->q, s->pklen);
8369 memcpy(s->q, s->pkblob, s->pklen);
8371 PUT_32BIT(s->q, s->siglen);
8373 /* Now the data to be signed... */
8374 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8375 PUT_32BIT(s->q, ssh->v2_session_id_len);
8378 memcpy(s->q, ssh->v2_session_id,
8379 ssh->v2_session_id_len);
8380 s->q += ssh->v2_session_id_len;
8381 memcpy(s->q, s->pktout->data + 5,
8382 s->pktout->length - 5);
8383 s->q += s->pktout->length - 5;
8384 /* And finally the (zero) flags word. */
8386 if (!agent_query(s->agentreq, s->len + 4,
8388 ssh_agent_callback, ssh)) {
8392 bombout(("Unexpected data from server"
8393 " while waiting for agent"
8397 } while (pktin || inlen > 0);
8398 vret = ssh->agent_response;
8399 s->retlen = ssh->agent_response_len;
8404 if (s->retlen >= 9 &&
8405 s->ret[4] == SSH2_AGENT_SIGN_RESPONSE &&
8406 GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) {
8407 logevent("Sending Pageant's response");
8408 ssh2_add_sigblob(ssh, s->pktout,
8409 s->pkblob, s->pklen,
8411 GET_32BIT(s->ret + 5));
8412 ssh2_pkt_send(ssh, s->pktout);
8413 s->type = AUTH_TYPE_PUBLICKEY;
8415 /* FIXME: less drastic response */
8416 bombout(("Pageant failed to answer challenge"));
8422 /* Do we have any keys left to try? */
8423 if (s->pkblob_in_agent) {
8424 s->done_agent = TRUE;
8425 s->tried_pubkey_config = TRUE;
8428 if (s->keyi >= s->nkeys)
8429 s->done_agent = TRUE;
8432 } else if (s->can_pubkey && s->publickey_blob &&
8433 !s->tried_pubkey_config) {
8435 struct ssh2_userkey *key; /* not live over crReturn */
8436 char *passphrase; /* not live over crReturn */
8438 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
8440 s->tried_pubkey_config = TRUE;
8443 * Try the public key supplied in the configuration.
8445 * First, offer the public blob to see if the server is
8446 * willing to accept it.
8448 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8449 ssh2_pkt_addstring(s->pktout, ssh->username);
8450 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8451 /* service requested */
8452 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
8453 ssh2_pkt_addbool(s->pktout, FALSE);
8454 /* no signature included */
8455 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
8456 ssh2_pkt_addstring_start(s->pktout);
8457 ssh2_pkt_addstring_data(s->pktout,
8458 (char *)s->publickey_blob,
8459 s->publickey_bloblen);
8460 ssh2_pkt_send(ssh, s->pktout);
8461 logevent("Offered public key");
8463 crWaitUntilV(pktin);
8464 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
8465 /* Key refused. Give up. */
8466 s->gotit = TRUE; /* reconsider message next loop */
8467 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
8468 continue; /* process this new message */
8470 logevent("Offer of public key accepted");
8473 * Actually attempt a serious authentication using
8476 if (flags & FLAG_VERBOSE) {
8477 c_write_str(ssh, "Authenticating with public key \"");
8478 c_write_str(ssh, s->publickey_comment);
8479 c_write_str(ssh, "\"\r\n");
8483 const char *error; /* not live over crReturn */
8484 if (s->publickey_encrypted) {
8486 * Get a passphrase from the user.
8488 int ret; /* need not be kept over crReturn */
8489 s->cur_prompt = new_prompts(ssh->frontend);
8490 s->cur_prompt->to_server = FALSE;
8491 s->cur_prompt->name = dupstr("SSH key passphrase");
8492 add_prompt(s->cur_prompt,
8493 dupprintf("Passphrase for key \"%.100s\": ",
8494 s->publickey_comment),
8496 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8499 crWaitUntilV(!pktin);
8500 ret = get_userpass_input(s->cur_prompt,
8505 /* Failed to get a passphrase. Terminate. */
8506 free_prompts(s->cur_prompt);
8507 ssh_disconnect(ssh, NULL,
8508 "Unable to authenticate",
8509 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8514 dupstr(s->cur_prompt->prompts[0]->result);
8515 free_prompts(s->cur_prompt);
8517 passphrase = NULL; /* no passphrase needed */
8521 * Try decrypting the key.
8523 s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile);
8524 key = ssh2_load_userkey(s->keyfile, passphrase, &error);
8526 /* burn the evidence */
8527 smemclr(passphrase, strlen(passphrase));
8530 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
8532 (key == SSH2_WRONG_PASSPHRASE)) {
8533 c_write_str(ssh, "Wrong passphrase\r\n");
8535 /* and loop again */
8537 c_write_str(ssh, "Unable to load private key (");
8538 c_write_str(ssh, error);
8539 c_write_str(ssh, ")\r\n");
8541 break; /* try something else */
8547 unsigned char *pkblob, *sigblob, *sigdata;
8548 int pkblob_len, sigblob_len, sigdata_len;
8552 * We have loaded the private key and the server
8553 * has announced that it's willing to accept it.
8554 * Hallelujah. Generate a signature and send it.
8556 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8557 ssh2_pkt_addstring(s->pktout, ssh->username);
8558 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8559 /* service requested */
8560 ssh2_pkt_addstring(s->pktout, "publickey");
8562 ssh2_pkt_addbool(s->pktout, TRUE);
8563 /* signature follows */
8564 ssh2_pkt_addstring(s->pktout, key->alg->name);
8565 pkblob = key->alg->public_blob(key->data,
8567 ssh2_pkt_addstring_start(s->pktout);
8568 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
8572 * The data to be signed is:
8576 * followed by everything so far placed in the
8579 sigdata_len = s->pktout->length - 5 + 4 +
8580 ssh->v2_session_id_len;
8581 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
8583 sigdata = snewn(sigdata_len, unsigned char);
8585 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
8586 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
8589 memcpy(sigdata+p, ssh->v2_session_id,
8590 ssh->v2_session_id_len);
8591 p += ssh->v2_session_id_len;
8592 memcpy(sigdata+p, s->pktout->data + 5,
8593 s->pktout->length - 5);
8594 p += s->pktout->length - 5;
8595 assert(p == sigdata_len);
8596 sigblob = key->alg->sign(key->data, (char *)sigdata,
8597 sigdata_len, &sigblob_len);
8598 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
8599 sigblob, sigblob_len);
8604 ssh2_pkt_send(ssh, s->pktout);
8605 logevent("Sent public key signature");
8606 s->type = AUTH_TYPE_PUBLICKEY;
8607 key->alg->freekey(key->data);
8611 } else if (s->can_gssapi && !s->tried_gssapi) {
8613 /* GSSAPI Authentication */
8618 s->type = AUTH_TYPE_GSSAPI;
8619 s->tried_gssapi = TRUE;
8621 ssh->pkt_actx = SSH2_PKTCTX_GSSAPI;
8624 * Pick the highest GSS library on the preference
8630 for (i = 0; i < ngsslibs; i++) {
8631 int want_id = conf_get_int_int(ssh->conf,
8632 CONF_ssh_gsslist, i);
8633 for (j = 0; j < ssh->gsslibs->nlibraries; j++)
8634 if (ssh->gsslibs->libraries[j].id == want_id) {
8635 s->gsslib = &ssh->gsslibs->libraries[j];
8636 goto got_gsslib; /* double break */
8641 * We always expect to have found something in
8642 * the above loop: we only came here if there
8643 * was at least one viable GSS library, and the
8644 * preference list should always mention
8645 * everything and only change the order.
8650 if (s->gsslib->gsslogmsg)
8651 logevent(s->gsslib->gsslogmsg);
8653 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8654 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8655 ssh2_pkt_addstring(s->pktout, ssh->username);
8656 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8657 ssh2_pkt_addstring(s->pktout, "gssapi-with-mic");
8658 logevent("Attempting GSSAPI authentication");
8660 /* add mechanism info */
8661 s->gsslib->indicate_mech(s->gsslib, &s->gss_buf);
8663 /* number of GSSAPI mechanisms */
8664 ssh2_pkt_adduint32(s->pktout,1);
8666 /* length of OID + 2 */
8667 ssh2_pkt_adduint32(s->pktout, s->gss_buf.length + 2);
8668 ssh2_pkt_addbyte(s->pktout, SSH2_GSS_OIDTYPE);
8671 ssh2_pkt_addbyte(s->pktout, (unsigned char) s->gss_buf.length);
8673 ssh_pkt_adddata(s->pktout, s->gss_buf.value,
8675 ssh2_pkt_send(ssh, s->pktout);
8676 crWaitUntilV(pktin);
8677 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_RESPONSE) {
8678 logevent("GSSAPI authentication request refused");
8682 /* check returned packet ... */
8684 ssh_pkt_getstring(pktin, &data, &len);
8685 s->gss_rcvtok.value = data;
8686 s->gss_rcvtok.length = len;
8687 if (s->gss_rcvtok.length != s->gss_buf.length + 2 ||
8688 ((char *)s->gss_rcvtok.value)[0] != SSH2_GSS_OIDTYPE ||
8689 ((char *)s->gss_rcvtok.value)[1] != s->gss_buf.length ||
8690 memcmp((char *)s->gss_rcvtok.value + 2,
8691 s->gss_buf.value,s->gss_buf.length) ) {
8692 logevent("GSSAPI authentication - wrong response from server");
8696 /* now start running */
8697 s->gss_stat = s->gsslib->import_name(s->gsslib,
8700 if (s->gss_stat != SSH_GSS_OK) {
8701 if (s->gss_stat == SSH_GSS_BAD_HOST_NAME)
8702 logevent("GSSAPI import name failed - Bad service name");
8704 logevent("GSSAPI import name failed");
8708 /* fetch TGT into GSS engine */
8709 s->gss_stat = s->gsslib->acquire_cred(s->gsslib, &s->gss_ctx);
8711 if (s->gss_stat != SSH_GSS_OK) {
8712 logevent("GSSAPI authentication failed to get credentials");
8713 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8717 /* initial tokens are empty */
8718 SSH_GSS_CLEAR_BUF(&s->gss_rcvtok);
8719 SSH_GSS_CLEAR_BUF(&s->gss_sndtok);
8721 /* now enter the loop */
8723 s->gss_stat = s->gsslib->init_sec_context
8727 conf_get_int(ssh->conf, CONF_gssapifwd),
8731 if (s->gss_stat!=SSH_GSS_S_COMPLETE &&
8732 s->gss_stat!=SSH_GSS_S_CONTINUE_NEEDED) {
8733 logevent("GSSAPI authentication initialisation failed");
8735 if (s->gsslib->display_status(s->gsslib, s->gss_ctx,
8736 &s->gss_buf) == SSH_GSS_OK) {
8737 logevent(s->gss_buf.value);
8738 sfree(s->gss_buf.value);
8743 logevent("GSSAPI authentication initialised");
8745 /* Client and server now exchange tokens until GSSAPI
8746 * no longer says CONTINUE_NEEDED */
8748 if (s->gss_sndtok.length != 0) {
8749 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
8750 ssh_pkt_addstring_start(s->pktout);
8751 ssh_pkt_addstring_data(s->pktout,s->gss_sndtok.value,s->gss_sndtok.length);
8752 ssh2_pkt_send(ssh, s->pktout);
8753 s->gsslib->free_tok(s->gsslib, &s->gss_sndtok);
8756 if (s->gss_stat == SSH_GSS_S_CONTINUE_NEEDED) {
8757 crWaitUntilV(pktin);
8758 if (pktin->type != SSH2_MSG_USERAUTH_GSSAPI_TOKEN) {
8759 logevent("GSSAPI authentication - bad server response");
8760 s->gss_stat = SSH_GSS_FAILURE;
8763 ssh_pkt_getstring(pktin, &data, &len);
8764 s->gss_rcvtok.value = data;
8765 s->gss_rcvtok.length = len;
8767 } while (s-> gss_stat == SSH_GSS_S_CONTINUE_NEEDED);
8769 if (s->gss_stat != SSH_GSS_OK) {
8770 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8771 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8774 logevent("GSSAPI authentication loop finished OK");
8776 /* Now send the MIC */
8778 s->pktout = ssh2_pkt_init(0);
8779 micoffset = s->pktout->length;
8780 ssh_pkt_addstring_start(s->pktout);
8781 ssh_pkt_addstring_data(s->pktout, (char *)ssh->v2_session_id, ssh->v2_session_id_len);
8782 ssh_pkt_addbyte(s->pktout, SSH2_MSG_USERAUTH_REQUEST);
8783 ssh_pkt_addstring(s->pktout, ssh->username);
8784 ssh_pkt_addstring(s->pktout, "ssh-connection");
8785 ssh_pkt_addstring(s->pktout, "gssapi-with-mic");
8787 s->gss_buf.value = (char *)s->pktout->data + micoffset;
8788 s->gss_buf.length = s->pktout->length - micoffset;
8790 s->gsslib->get_mic(s->gsslib, s->gss_ctx, &s->gss_buf, &mic);
8791 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC);
8792 ssh_pkt_addstring_start(s->pktout);
8793 ssh_pkt_addstring_data(s->pktout, mic.value, mic.length);
8794 ssh2_pkt_send(ssh, s->pktout);
8795 s->gsslib->free_mic(s->gsslib, &mic);
8799 s->gsslib->release_name(s->gsslib, &s->gss_srv_name);
8800 s->gsslib->release_cred(s->gsslib, &s->gss_ctx);
8803 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
8806 * Keyboard-interactive authentication.
8809 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
8811 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
8813 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
8814 ssh2_pkt_addstring(s->pktout, ssh->username);
8815 ssh2_pkt_addstring(s->pktout, "ssh-connection");
8816 /* service requested */
8817 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
8819 ssh2_pkt_addstring(s->pktout, ""); /* lang */
8820 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
8821 ssh2_pkt_send(ssh, s->pktout);
8823 logevent("Attempting keyboard-interactive authentication");
8825 crWaitUntilV(pktin);
8826 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
8827 /* Server is not willing to do keyboard-interactive
8828 * at all (or, bizarrely but legally, accepts the
8829 * user without actually issuing any prompts).
8830 * Give up on it entirely. */
8832 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
8833 s->kbd_inter_refused = TRUE; /* don't try it again */
8838 * Loop while the server continues to send INFO_REQUESTs.
8840 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
8842 char *name, *inst, *lang;
8843 int name_len, inst_len, lang_len;
8847 * We've got a fresh USERAUTH_INFO_REQUEST.
8848 * Get the preamble and start building a prompt.
8850 ssh_pkt_getstring(pktin, &name, &name_len);
8851 ssh_pkt_getstring(pktin, &inst, &inst_len);
8852 ssh_pkt_getstring(pktin, &lang, &lang_len);
8853 s->cur_prompt = new_prompts(ssh->frontend);
8854 s->cur_prompt->to_server = TRUE;
8857 * Get any prompt(s) from the packet.
8859 s->num_prompts = ssh_pkt_getuint32(pktin);
8860 for (i = 0; i < s->num_prompts; i++) {
8864 static char noprompt[] =
8865 "<server failed to send prompt>: ";
8867 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
8868 echo = ssh2_pkt_getbool(pktin);
8871 prompt_len = lenof(noprompt)-1;
8873 add_prompt(s->cur_prompt,
8874 dupprintf("%.*s", prompt_len, prompt),
8879 /* FIXME: better prefix to distinguish from
8881 s->cur_prompt->name =
8882 dupprintf("SSH server: %.*s", name_len, name);
8883 s->cur_prompt->name_reqd = TRUE;
8885 s->cur_prompt->name =
8886 dupstr("SSH server authentication");
8887 s->cur_prompt->name_reqd = FALSE;
8889 /* We add a prefix to try to make it clear that a prompt
8890 * has come from the server.
8891 * FIXME: ugly to print "Using..." in prompt _every_
8892 * time round. Can this be done more subtly? */
8893 /* Special case: for reasons best known to themselves,
8894 * some servers send k-i requests with no prompts and
8895 * nothing to display. Keep quiet in this case. */
8896 if (s->num_prompts || name_len || inst_len) {
8897 s->cur_prompt->instruction =
8898 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8899 inst_len ? "\n" : "", inst_len, inst);
8900 s->cur_prompt->instr_reqd = TRUE;
8902 s->cur_prompt->instr_reqd = FALSE;
8906 * Display any instructions, and get the user's
8910 int ret; /* not live over crReturn */
8911 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8914 crWaitUntilV(!pktin);
8915 ret = get_userpass_input(s->cur_prompt, in, inlen);
8920 * Failed to get responses. Terminate.
8922 free_prompts(s->cur_prompt);
8923 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8924 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8931 * Send the response(s) to the server.
8933 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
8934 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
8935 for (i=0; i < s->num_prompts; i++) {
8936 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8937 ssh2_pkt_addstring(s->pktout,
8938 s->cur_prompt->prompts[i]->result);
8939 end_log_omission(ssh, s->pktout);
8941 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
8944 * Free the prompts structure from this iteration.
8945 * If there's another, a new one will be allocated
8946 * when we return to the top of this while loop.
8948 free_prompts(s->cur_prompt);
8951 * Get the next packet in case it's another
8954 crWaitUntilV(pktin);
8959 * We should have SUCCESS or FAILURE now.
8963 } else if (s->can_passwd) {
8966 * Plain old password authentication.
8968 int ret; /* not live over crReturn */
8969 int changereq_first_time; /* not live over crReturn */
8971 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
8973 s->cur_prompt = new_prompts(ssh->frontend);
8974 s->cur_prompt->to_server = TRUE;
8975 s->cur_prompt->name = dupstr("SSH password");
8976 add_prompt(s->cur_prompt, dupprintf("%s@%s's password: ",
8981 ret = get_userpass_input(s->cur_prompt, NULL, 0);
8984 crWaitUntilV(!pktin);
8985 ret = get_userpass_input(s->cur_prompt, in, inlen);
8990 * Failed to get responses. Terminate.
8992 free_prompts(s->cur_prompt);
8993 ssh_disconnect(ssh, NULL, "Unable to authenticate",
8994 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
8999 * Squirrel away the password. (We may need it later if
9000 * asked to change it.)
9002 s->password = dupstr(s->cur_prompt->prompts[0]->result);
9003 free_prompts(s->cur_prompt);
9006 * Send the password packet.
9008 * We pad out the password packet to 256 bytes to make
9009 * it harder for an attacker to find the length of the
9012 * Anyone using a password longer than 256 bytes
9013 * probably doesn't have much to worry about from
9014 * people who find out how long their password is!
9016 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9017 ssh2_pkt_addstring(s->pktout, ssh->username);
9018 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9019 /* service requested */
9020 ssh2_pkt_addstring(s->pktout, "password");
9021 ssh2_pkt_addbool(s->pktout, FALSE);
9022 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9023 ssh2_pkt_addstring(s->pktout, s->password);
9024 end_log_omission(ssh, s->pktout);
9025 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9026 logevent("Sent password");
9027 s->type = AUTH_TYPE_PASSWORD;
9030 * Wait for next packet, in case it's a password change
9033 crWaitUntilV(pktin);
9034 changereq_first_time = TRUE;
9036 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
9039 * We're being asked for a new password
9040 * (perhaps not for the first time).
9041 * Loop until the server accepts it.
9044 int got_new = FALSE; /* not live over crReturn */
9045 char *prompt; /* not live over crReturn */
9046 int prompt_len; /* not live over crReturn */
9050 if (changereq_first_time)
9051 msg = "Server requested password change";
9053 msg = "Server rejected new password";
9055 c_write_str(ssh, msg);
9056 c_write_str(ssh, "\r\n");
9059 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
9061 s->cur_prompt = new_prompts(ssh->frontend);
9062 s->cur_prompt->to_server = TRUE;
9063 s->cur_prompt->name = dupstr("New SSH password");
9064 s->cur_prompt->instruction =
9065 dupprintf("%.*s", prompt_len, prompt);
9066 s->cur_prompt->instr_reqd = TRUE;
9068 * There's no explicit requirement in the protocol
9069 * for the "old" passwords in the original and
9070 * password-change messages to be the same, and
9071 * apparently some Cisco kit supports password change
9072 * by the user entering a blank password originally
9073 * and the real password subsequently, so,
9074 * reluctantly, we prompt for the old password again.
9076 * (On the other hand, some servers don't even bother
9077 * to check this field.)
9079 add_prompt(s->cur_prompt,
9080 dupstr("Current password (blank for previously entered password): "),
9082 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
9084 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
9088 * Loop until the user manages to enter the same
9093 ret = get_userpass_input(s->cur_prompt, NULL, 0);
9096 crWaitUntilV(!pktin);
9097 ret = get_userpass_input(s->cur_prompt, in, inlen);
9102 * Failed to get responses. Terminate.
9104 /* burn the evidence */
9105 free_prompts(s->cur_prompt);
9106 smemclr(s->password, strlen(s->password));
9108 ssh_disconnect(ssh, NULL, "Unable to authenticate",
9109 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
9115 * If the user specified a new original password
9116 * (IYSWIM), overwrite any previously specified
9118 * (A side effect is that the user doesn't have to
9119 * re-enter it if they louse up the new password.)
9121 if (s->cur_prompt->prompts[0]->result[0]) {
9122 smemclr(s->password, strlen(s->password));
9123 /* burn the evidence */
9126 dupstr(s->cur_prompt->prompts[0]->result);
9130 * Check the two new passwords match.
9132 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
9133 s->cur_prompt->prompts[2]->result)
9136 /* They don't. Silly user. */
9137 c_write_str(ssh, "Passwords do not match\r\n");
9142 * Send the new password (along with the old one).
9143 * (see above for padding rationale)
9145 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
9146 ssh2_pkt_addstring(s->pktout, ssh->username);
9147 ssh2_pkt_addstring(s->pktout, "ssh-connection");
9148 /* service requested */
9149 ssh2_pkt_addstring(s->pktout, "password");
9150 ssh2_pkt_addbool(s->pktout, TRUE);
9151 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
9152 ssh2_pkt_addstring(s->pktout, s->password);
9153 ssh2_pkt_addstring(s->pktout,
9154 s->cur_prompt->prompts[1]->result);
9155 free_prompts(s->cur_prompt);
9156 end_log_omission(ssh, s->pktout);
9157 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
9158 logevent("Sent new password");
9161 * Now see what the server has to say about it.
9162 * (If it's CHANGEREQ again, it's not happy with the
9165 crWaitUntilV(pktin);
9166 changereq_first_time = FALSE;
9171 * We need to reexamine the current pktin at the top
9172 * of the loop. Either:
9173 * - we weren't asked to change password at all, in
9174 * which case it's a SUCCESS or FAILURE with the
9176 * - we sent a new password, and the server was
9177 * either OK with it (SUCCESS or FAILURE w/partial
9178 * success) or unhappy with the _old_ password
9179 * (FAILURE w/o partial success)
9180 * In any of these cases, we go back to the top of
9181 * the loop and start again.
9186 * We don't need the old password any more, in any
9187 * case. Burn the evidence.
9189 smemclr(s->password, strlen(s->password));
9193 char *str = dupprintf("No supported authentication methods available"
9194 " (server sent: %.*s)",
9197 ssh_disconnect(ssh, str,
9198 "No supported authentication methods available",
9199 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
9209 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
9211 /* Clear up various bits and pieces from authentication. */
9212 if (s->publickey_blob) {
9213 sfree(s->publickey_blob);
9214 sfree(s->publickey_comment);
9216 if (s->agent_response)
9217 sfree(s->agent_response);
9219 if (s->userauth_success) {
9221 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9222 * packets since. Signal the transport layer to consider enacting
9223 * delayed compression.
9225 * (Relying on we_are_in is not sufficient, as
9226 * draft-miller-secsh-compression-delayed is quite clear that it
9227 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9228 * become set for other reasons.)
9230 do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL);
9234 * Now the connection protocol has started, one way or another.
9237 ssh->channels = newtree234(ssh_channelcmp);
9240 * Set up handlers for some connection protocol messages, so we
9241 * don't have to handle them repeatedly in this coroutine.
9243 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
9244 ssh2_msg_channel_window_adjust;
9245 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
9246 ssh2_msg_global_request;
9249 * Create the main session channel.
9251 if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) {
9252 ssh->mainchan = NULL;
9254 ssh->mainchan = snew(struct ssh_channel);
9255 ssh->mainchan->ssh = ssh;
9256 ssh2_channel_init(ssh->mainchan);
9258 if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) {
9260 * Just start a direct-tcpip channel and use it as the main
9263 ssh_send_port_open(ssh->mainchan,
9264 conf_get_str(ssh->conf, CONF_ssh_nc_host),
9265 conf_get_int(ssh->conf, CONF_ssh_nc_port),
9269 s->pktout = ssh2_chanopen_init(ssh->mainchan, "session");
9270 logevent("Opening session as main channel");
9271 ssh2_pkt_send(ssh, s->pktout);
9272 ssh->ncmode = FALSE;
9274 crWaitUntilV(pktin);
9275 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
9276 bombout(("Server refused to open channel"));
9278 /* FIXME: error data comes back in FAILURE packet */
9280 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
9281 bombout(("Server's channel confirmation cited wrong channel"));
9284 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
9285 ssh->mainchan->halfopen = FALSE;
9286 ssh->mainchan->type = CHAN_MAINSESSION;
9287 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
9288 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
9289 add234(ssh->channels, ssh->mainchan);
9290 update_specials_menu(ssh->frontend);
9291 logevent("Opened main channel");
9295 * Now we have a channel, make dispatch table entries for
9296 * general channel-based messages.
9298 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
9299 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
9300 ssh2_msg_channel_data;
9301 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
9302 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
9303 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
9304 ssh2_msg_channel_open_confirmation;
9305 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
9306 ssh2_msg_channel_open_failure;
9307 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
9308 ssh2_msg_channel_request;
9309 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
9310 ssh2_msg_channel_open;
9311 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response;
9312 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response;
9315 if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) {
9317 * This message indicates to the server that we promise
9318 * not to try to run any other channel in parallel with
9319 * this one, so it's safe for it to advertise a very large
9320 * window and leave the flow control to TCP.
9322 s->pktout = ssh2_chanreq_init(ssh->mainchan,
9323 "simple@putty.projects.tartarus.org",
9325 ssh2_pkt_send(ssh, s->pktout);
9329 * Enable port forwardings.
9331 ssh_setup_portfwd(ssh, ssh->conf);
9333 if (ssh->mainchan && !ssh->ncmode) {
9335 * Send the CHANNEL_REQUESTS for the main session channel.
9336 * Each one is handled by its own little asynchronous
9340 /* Potentially enable X11 forwarding. */
9341 if (conf_get_int(ssh->conf, CONF_x11_forward) &&
9343 x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display),
9344 conf_get_int(ssh->conf, CONF_x11_auth),
9346 ssh2_setup_x11(ssh->mainchan, NULL, NULL);
9348 /* Potentially enable agent forwarding. */
9349 if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists())
9350 ssh2_setup_agent(ssh->mainchan, NULL, NULL);
9352 /* Now allocate a pty for the session. */
9353 if (!conf_get_int(ssh->conf, CONF_nopty))
9354 ssh2_setup_pty(ssh->mainchan, NULL, NULL);
9356 /* Send environment variables. */
9357 ssh2_setup_env(ssh->mainchan, NULL, NULL);
9360 * Start a shell or a remote command. We may have to attempt
9361 * this twice if the config data has provided a second choice
9368 if (ssh->fallback_cmd) {
9369 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2);
9370 cmd = conf_get_str(ssh->conf, CONF_remote_cmd2);
9372 subsys = conf_get_int(ssh->conf, CONF_ssh_subsys);
9373 cmd = conf_get_str(ssh->conf, CONF_remote_cmd);
9377 s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem",
9378 ssh2_response_authconn, NULL);
9379 ssh2_pkt_addstring(s->pktout, cmd);
9381 s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec",
9382 ssh2_response_authconn, NULL);
9383 ssh2_pkt_addstring(s->pktout, cmd);
9385 s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell",
9386 ssh2_response_authconn, NULL);
9388 ssh2_pkt_send(ssh, s->pktout);
9390 crWaitUntilV(pktin);
9392 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
9393 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
9394 bombout(("Unexpected response to shell/command request:"
9395 " packet type %d", pktin->type));
9399 * We failed to start the command. If this is the
9400 * fallback command, we really are finished; if it's
9401 * not, and if the fallback command exists, try falling
9402 * back to it before complaining.
9404 if (!ssh->fallback_cmd &&
9405 *conf_get_str(ssh->conf, CONF_remote_cmd2)) {
9406 logevent("Primary command failed; attempting fallback");
9407 ssh->fallback_cmd = TRUE;
9410 bombout(("Server refused to start a shell/command"));
9413 logevent("Started a shell/command");
9418 ssh->editing = ssh->echoing = TRUE;
9421 ssh->state = SSH_STATE_SESSION;
9422 if (ssh->size_needed)
9423 ssh_size(ssh, ssh->term_width, ssh->term_height);
9424 if (ssh->eof_needed)
9425 ssh_special(ssh, TS_EOF);
9431 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
9436 s->try_send = FALSE;
9440 * _All_ the connection-layer packets we expect to
9441 * receive are now handled by the dispatch table.
9442 * Anything that reaches here must be bogus.
9445 bombout(("Strange packet received: type %d", pktin->type));
9447 } else if (ssh->mainchan) {
9449 * We have spare data. Add it to the channel buffer.
9451 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
9456 struct ssh_channel *c;
9458 * Try to send data on all channels if we can.
9460 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
9461 ssh2_try_send_and_unthrottle(ssh, c);
9469 * Handlers for SSH-2 messages that might arrive at any moment.
9471 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
9473 /* log reason code in disconnect message */
9477 reason = ssh_pkt_getuint32(pktin);
9478 ssh_pkt_getstring(pktin, &msg, &msglen);
9480 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
9481 buf = dupprintf("Received disconnect message (%s)",
9482 ssh2_disconnect_reasons[reason]);
9484 buf = dupprintf("Received disconnect message (unknown"
9485 " type %d)", reason);
9489 buf = dupprintf("Disconnection message text: %.*s",
9492 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9494 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
9495 ssh2_disconnect_reasons[reason] : "unknown",
9500 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
9502 /* log the debug message */
9506 /* XXX maybe we should actually take notice of the return value */
9507 ssh2_pkt_getbool(pktin);
9508 ssh_pkt_getstring(pktin, &msg, &msglen);
9510 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
9513 static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin)
9515 do_ssh2_transport(ssh, NULL, 0, pktin);
9519 * Called if we receive a packet that isn't allowed by the protocol.
9520 * This only applies to packets whose meaning PuTTY understands.
9521 * Entirely unknown packets are handled below.
9523 static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin)
9525 char *buf = dupprintf("Server protocol violation: unexpected %s packet",
9526 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
9528 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
9532 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
9534 struct Packet *pktout;
9535 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
9536 ssh2_pkt_adduint32(pktout, pktin->sequence);
9538 * UNIMPLEMENTED messages MUST appear in the same order as the
9539 * messages they respond to. Hence, never queue them.
9541 ssh2_pkt_send_noqueue(ssh, pktout);
9545 * Handle the top-level SSH-2 protocol.
9547 static void ssh2_protocol_setup(Ssh ssh)
9552 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9554 for (i = 0; i < 256; i++)
9555 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
9558 * Initially, we only accept transport messages (and a few generic
9559 * ones). do_ssh2_authconn will add more when it starts.
9560 * Messages that are understood but not currently acceptable go to
9561 * ssh2_msg_unexpected.
9563 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected;
9564 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = ssh2_msg_unexpected;
9565 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = ssh2_msg_unexpected;
9566 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = ssh2_msg_transport;
9567 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = ssh2_msg_transport;
9568 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = ssh2_msg_transport;
9569 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = ssh2_msg_transport;
9570 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9571 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9572 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = ssh2_msg_transport;
9573 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = ssh2_msg_transport;
9574 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = ssh2_msg_unexpected;
9575 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = ssh2_msg_unexpected;
9576 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = ssh2_msg_unexpected;
9577 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = ssh2_msg_unexpected;
9578 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = ssh2_msg_unexpected;
9579 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9580 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9581 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = ssh2_msg_unexpected;
9582 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected;
9583 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected;
9584 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected;
9585 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected;
9586 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected;
9587 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected;
9588 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected;
9589 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected;
9590 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected;
9591 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected;
9592 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected;
9593 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected;
9594 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected;
9595 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected;
9598 * These messages have a special handler from the start.
9600 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
9601 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
9602 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
9605 static void ssh2_timer(void *ctx, unsigned long now)
9609 if (ssh->state == SSH_STATE_CLOSED)
9612 if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 &&
9613 now == ssh->next_rekey) {
9614 do_ssh2_transport(ssh, "timeout", -1, NULL);
9618 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
9619 struct Packet *pktin)
9621 unsigned char *in = (unsigned char *)vin;
9622 if (ssh->state == SSH_STATE_CLOSED)
9626 ssh->incoming_data_size += pktin->encrypted_len;
9627 if (!ssh->kex_in_progress &&
9628 ssh->max_data_size != 0 &&
9629 ssh->incoming_data_size > ssh->max_data_size)
9630 do_ssh2_transport(ssh, "too much data received", -1, NULL);
9634 ssh->packet_dispatch[pktin->type](ssh, pktin);
9635 else if (!ssh->protocol_initial_phase_done)
9636 do_ssh2_transport(ssh, in, inlen, pktin);
9638 do_ssh2_authconn(ssh, in, inlen, pktin);
9641 static void ssh_cache_conf_values(Ssh ssh)
9643 ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata);
9647 * Called to set up the connection.
9649 * Returns an error message, or NULL on success.
9651 static const char *ssh_init(void *frontend_handle, void **backend_handle,
9652 Conf *conf, char *host, int port, char **realhost,
9653 int nodelay, int keepalive)
9658 ssh = snew(struct ssh_tag);
9659 ssh->conf = conf_copy(conf);
9660 ssh_cache_conf_values(ssh);
9661 ssh->version = 0; /* when not ready yet */
9664 ssh->v1_cipher_ctx = NULL;
9665 ssh->crcda_ctx = NULL;
9666 ssh->cscipher = NULL;
9667 ssh->cs_cipher_ctx = NULL;
9668 ssh->sccipher = NULL;
9669 ssh->sc_cipher_ctx = NULL;
9671 ssh->cs_mac_ctx = NULL;
9673 ssh->sc_mac_ctx = NULL;
9675 ssh->cs_comp_ctx = NULL;
9677 ssh->sc_comp_ctx = NULL;
9679 ssh->kex_ctx = NULL;
9680 ssh->hostkey = NULL;
9681 ssh->hostkey_str = NULL;
9683 ssh->close_expected = FALSE;
9684 ssh->clean_exit = FALSE;
9685 ssh->state = SSH_STATE_PREPACKET;
9686 ssh->size_needed = FALSE;
9687 ssh->eof_needed = FALSE;
9690 ssh->deferred_send_data = NULL;
9691 ssh->deferred_len = 0;
9692 ssh->deferred_size = 0;
9693 ssh->fallback_cmd = 0;
9694 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
9695 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
9696 ssh->x11disp = NULL;
9697 ssh->v1_compressing = FALSE;
9698 ssh->v2_outgoing_sequence = 0;
9699 ssh->ssh1_rdpkt_crstate = 0;
9700 ssh->ssh2_rdpkt_crstate = 0;
9701 ssh->ssh_gotdata_crstate = 0;
9702 ssh->do_ssh1_connection_crstate = 0;
9703 ssh->do_ssh_init_state = NULL;
9704 ssh->do_ssh1_login_state = NULL;
9705 ssh->do_ssh2_transport_state = NULL;
9706 ssh->do_ssh2_authconn_state = NULL;
9709 ssh->mainchan = NULL;
9710 ssh->throttled_all = 0;
9711 ssh->v1_stdout_throttling = 0;
9713 ssh->queuelen = ssh->queuesize = 0;
9714 ssh->queueing = FALSE;
9715 ssh->qhead = ssh->qtail = NULL;
9716 ssh->deferred_rekey_reason = NULL;
9717 bufchain_init(&ssh->queued_incoming_data);
9718 ssh->frozen = FALSE;
9719 ssh->username = NULL;
9720 ssh->sent_console_eof = FALSE;
9721 ssh->got_pty = FALSE;
9723 *backend_handle = ssh;
9726 if (crypto_startup() == 0)
9727 return "Microsoft high encryption pack not installed!";
9730 ssh->frontend = frontend_handle;
9731 ssh->term_width = conf_get_int(ssh->conf, CONF_width);
9732 ssh->term_height = conf_get_int(ssh->conf, CONF_height);
9734 ssh->channels = NULL;
9735 ssh->rportfwds = NULL;
9736 ssh->portfwds = NULL;
9741 ssh->conn_throttle_count = 0;
9742 ssh->overall_bufsize = 0;
9743 ssh->fallback_cmd = 0;
9745 ssh->protocol = NULL;
9747 ssh->protocol_initial_phase_done = FALSE;
9751 ssh->incoming_data_size = ssh->outgoing_data_size =
9752 ssh->deferred_data_size = 0L;
9753 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9754 CONF_ssh_rekey_data));
9755 ssh->kex_in_progress = FALSE;
9758 ssh->gsslibs = NULL;
9761 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
9770 static void ssh_free(void *handle)
9772 Ssh ssh = (Ssh) handle;
9773 struct ssh_channel *c;
9774 struct ssh_rportfwd *pf;
9776 if (ssh->v1_cipher_ctx)
9777 ssh->cipher->free_context(ssh->v1_cipher_ctx);
9778 if (ssh->cs_cipher_ctx)
9779 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
9780 if (ssh->sc_cipher_ctx)
9781 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
9782 if (ssh->cs_mac_ctx)
9783 ssh->csmac->free_context(ssh->cs_mac_ctx);
9784 if (ssh->sc_mac_ctx)
9785 ssh->scmac->free_context(ssh->sc_mac_ctx);
9786 if (ssh->cs_comp_ctx) {
9788 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
9790 zlib_compress_cleanup(ssh->cs_comp_ctx);
9792 if (ssh->sc_comp_ctx) {
9794 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
9796 zlib_decompress_cleanup(ssh->sc_comp_ctx);
9799 dh_cleanup(ssh->kex_ctx);
9800 sfree(ssh->savedhost);
9802 while (ssh->queuelen-- > 0)
9803 ssh_free_packet(ssh->queue[ssh->queuelen]);
9806 while (ssh->qhead) {
9807 struct queued_handler *qh = ssh->qhead;
9808 ssh->qhead = qh->next;
9811 ssh->qhead = ssh->qtail = NULL;
9813 if (ssh->channels) {
9814 while ((c = delpos234(ssh->channels, 0)) != NULL) {
9817 if (c->u.x11.s != NULL)
9818 x11_close(c->u.x11.s);
9821 case CHAN_SOCKDATA_DORMANT:
9822 if (c->u.pfd.s != NULL)
9823 pfd_close(c->u.pfd.s);
9826 if (ssh->version == 2) {
9827 struct outstanding_channel_request *ocr, *nocr;
9828 ocr = c->v.v2.chanreq_head;
9830 ocr->handler(c, NULL, ocr->ctx);
9835 bufchain_clear(&c->v.v2.outbuffer);
9839 freetree234(ssh->channels);
9840 ssh->channels = NULL;
9843 if (ssh->rportfwds) {
9844 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
9846 freetree234(ssh->rportfwds);
9847 ssh->rportfwds = NULL;
9849 sfree(ssh->deferred_send_data);
9851 x11_free_display(ssh->x11disp);
9852 sfree(ssh->do_ssh_init_state);
9853 sfree(ssh->do_ssh1_login_state);
9854 sfree(ssh->do_ssh2_transport_state);
9855 sfree(ssh->do_ssh2_authconn_state);
9858 sfree(ssh->fullhostname);
9859 sfree(ssh->hostkey_str);
9860 if (ssh->crcda_ctx) {
9861 crcda_free_context(ssh->crcda_ctx);
9862 ssh->crcda_ctx = NULL;
9865 ssh_do_close(ssh, TRUE);
9866 expire_timer_context(ssh);
9868 pinger_free(ssh->pinger);
9869 bufchain_clear(&ssh->queued_incoming_data);
9870 sfree(ssh->username);
9871 conf_free(ssh->conf);
9874 ssh_gss_cleanup(ssh->gsslibs);
9882 * Reconfigure the SSH backend.
9884 static void ssh_reconfig(void *handle, Conf *conf)
9886 Ssh ssh = (Ssh) handle;
9887 char *rekeying = NULL, rekey_mandatory = FALSE;
9888 unsigned long old_max_data_size;
9891 pinger_reconfig(ssh->pinger, ssh->conf, conf);
9893 ssh_setup_portfwd(ssh, conf);
9895 rekey_time = conf_get_int(conf, CONF_ssh_rekey_time);
9896 if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time &&
9898 unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC;
9899 unsigned long now = GETTICKCOUNT();
9901 if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) {
9902 rekeying = "timeout shortened";
9904 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
9908 old_max_data_size = ssh->max_data_size;
9909 ssh->max_data_size = parse_blocksize(conf_get_str(ssh->conf,
9910 CONF_ssh_rekey_data));
9911 if (old_max_data_size != ssh->max_data_size &&
9912 ssh->max_data_size != 0) {
9913 if (ssh->outgoing_data_size > ssh->max_data_size ||
9914 ssh->incoming_data_size > ssh->max_data_size)
9915 rekeying = "data limit lowered";
9918 if (conf_get_int(ssh->conf, CONF_compression) !=
9919 conf_get_int(conf, CONF_compression)) {
9920 rekeying = "compression setting changed";
9921 rekey_mandatory = TRUE;
9924 for (i = 0; i < CIPHER_MAX; i++)
9925 if (conf_get_int_int(ssh->conf, CONF_ssh_cipherlist, i) !=
9926 conf_get_int_int(conf, CONF_ssh_cipherlist, i)) {
9927 rekeying = "cipher settings changed";
9928 rekey_mandatory = TRUE;
9930 if (conf_get_int(ssh->conf, CONF_ssh2_des_cbc) !=
9931 conf_get_int(conf, CONF_ssh2_des_cbc)) {
9932 rekeying = "cipher settings changed";
9933 rekey_mandatory = TRUE;
9936 conf_free(ssh->conf);
9937 ssh->conf = conf_copy(conf);
9938 ssh_cache_conf_values(ssh);
9941 if (!ssh->kex_in_progress) {
9942 do_ssh2_transport(ssh, rekeying, -1, NULL);
9943 } else if (rekey_mandatory) {
9944 ssh->deferred_rekey_reason = rekeying;
9950 * Called to send data down the SSH connection.
9952 static int ssh_send(void *handle, char *buf, int len)
9954 Ssh ssh = (Ssh) handle;
9956 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
9959 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
9961 return ssh_sendbuffer(ssh);
9965 * Called to query the current amount of buffered stdin data.
9967 static int ssh_sendbuffer(void *handle)
9969 Ssh ssh = (Ssh) handle;
9972 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
9976 * If the SSH socket itself has backed up, add the total backup
9977 * size on that to any individual buffer on the stdin channel.
9980 if (ssh->throttled_all)
9981 override_value = ssh->overall_bufsize;
9983 if (ssh->version == 1) {
9984 return override_value;
9985 } else if (ssh->version == 2) {
9987 return override_value;
9989 return (override_value +
9990 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
9997 * Called to set the size of the window from SSH's POV.
9999 static void ssh_size(void *handle, int width, int height)
10001 Ssh ssh = (Ssh) handle;
10002 struct Packet *pktout;
10004 ssh->term_width = width;
10005 ssh->term_height = height;
10007 switch (ssh->state) {
10008 case SSH_STATE_BEFORE_SIZE:
10009 case SSH_STATE_PREPACKET:
10010 case SSH_STATE_CLOSED:
10011 break; /* do nothing */
10012 case SSH_STATE_INTERMED:
10013 ssh->size_needed = TRUE; /* buffer for later */
10015 case SSH_STATE_SESSION:
10016 if (!conf_get_int(ssh->conf, CONF_nopty)) {
10017 if (ssh->version == 1) {
10018 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
10019 PKT_INT, ssh->term_height,
10020 PKT_INT, ssh->term_width,
10021 PKT_INT, 0, PKT_INT, 0, PKT_END);
10022 } else if (ssh->mainchan) {
10023 pktout = ssh2_chanreq_init(ssh->mainchan, "window-change",
10025 ssh2_pkt_adduint32(pktout, ssh->term_width);
10026 ssh2_pkt_adduint32(pktout, ssh->term_height);
10027 ssh2_pkt_adduint32(pktout, 0);
10028 ssh2_pkt_adduint32(pktout, 0);
10029 ssh2_pkt_send(ssh, pktout);
10037 * Return a list of the special codes that make sense in this
10040 static const struct telnet_special *ssh_get_specials(void *handle)
10042 static const struct telnet_special ssh1_ignore_special[] = {
10043 {"IGNORE message", TS_NOP}
10045 static const struct telnet_special ssh2_ignore_special[] = {
10046 {"IGNORE message", TS_NOP},
10048 static const struct telnet_special ssh2_rekey_special[] = {
10049 {"Repeat key exchange", TS_REKEY},
10051 static const struct telnet_special ssh2_session_specials[] = {
10054 /* These are the signal names defined by RFC 4254.
10055 * They include all the ISO C signals, but are a subset of the POSIX
10056 * required signals. */
10057 {"SIGINT (Interrupt)", TS_SIGINT},
10058 {"SIGTERM (Terminate)", TS_SIGTERM},
10059 {"SIGKILL (Kill)", TS_SIGKILL},
10060 {"SIGQUIT (Quit)", TS_SIGQUIT},
10061 {"SIGHUP (Hangup)", TS_SIGHUP},
10062 {"More signals", TS_SUBMENU},
10063 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
10064 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
10065 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
10066 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
10067 {NULL, TS_EXITMENU}
10069 static const struct telnet_special specials_end[] = {
10070 {NULL, TS_EXITMENU}
10072 /* XXX review this length for any changes: */
10073 static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) +
10074 lenof(ssh2_rekey_special) +
10075 lenof(ssh2_session_specials) +
10076 lenof(specials_end)];
10077 Ssh ssh = (Ssh) handle;
10079 #define ADD_SPECIALS(name) \
10081 assert((i + lenof(name)) <= lenof(ssh_specials)); \
10082 memcpy(&ssh_specials[i], name, sizeof name); \
10083 i += lenof(name); \
10086 if (ssh->version == 1) {
10087 /* Don't bother offering IGNORE if we've decided the remote
10088 * won't cope with it, since we wouldn't bother sending it if
10090 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10091 ADD_SPECIALS(ssh1_ignore_special);
10092 } else if (ssh->version == 2) {
10093 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE))
10094 ADD_SPECIALS(ssh2_ignore_special);
10095 if (!(ssh->remote_bugs & BUG_SSH2_REKEY))
10096 ADD_SPECIALS(ssh2_rekey_special);
10098 ADD_SPECIALS(ssh2_session_specials);
10099 } /* else we're not ready yet */
10102 ADD_SPECIALS(specials_end);
10103 return ssh_specials;
10107 #undef ADD_SPECIALS
10111 * Send special codes. TS_EOF is useful for `plink', so you
10112 * can send an EOF and collect resulting output (e.g. `plink
10115 static void ssh_special(void *handle, Telnet_Special code)
10117 Ssh ssh = (Ssh) handle;
10118 struct Packet *pktout;
10120 if (code == TS_EOF) {
10121 if (ssh->state != SSH_STATE_SESSION) {
10123 * Buffer the EOF in case we are pre-SESSION, so we can
10124 * send it as soon as we reach SESSION.
10126 if (code == TS_EOF)
10127 ssh->eof_needed = TRUE;
10130 if (ssh->version == 1) {
10131 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
10132 } else if (ssh->mainchan) {
10133 sshfwd_write_eof(ssh->mainchan);
10134 ssh->send_ok = 0; /* now stop trying to read from stdin */
10136 logevent("Sent EOF message");
10137 } else if (code == TS_PING || code == TS_NOP) {
10138 if (ssh->state == SSH_STATE_CLOSED
10139 || ssh->state == SSH_STATE_PREPACKET) return;
10140 if (ssh->version == 1) {
10141 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
10142 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
10144 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
10145 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
10146 ssh2_pkt_addstring_start(pktout);
10147 ssh2_pkt_send_noqueue(ssh, pktout);
10150 } else if (code == TS_REKEY) {
10151 if (!ssh->kex_in_progress && ssh->version == 2) {
10152 do_ssh2_transport(ssh, "at user request", -1, NULL);
10154 } else if (code == TS_BRK) {
10155 if (ssh->state == SSH_STATE_CLOSED
10156 || ssh->state == SSH_STATE_PREPACKET) return;
10157 if (ssh->version == 1) {
10158 logevent("Unable to send BREAK signal in SSH-1");
10159 } else if (ssh->mainchan) {
10160 pktout = ssh2_chanreq_init(ssh->mainchan, "break", NULL, NULL);
10161 ssh2_pkt_adduint32(pktout, 0); /* default break length */
10162 ssh2_pkt_send(ssh, pktout);
10165 /* Is is a POSIX signal? */
10166 char *signame = NULL;
10167 if (code == TS_SIGABRT) signame = "ABRT";
10168 if (code == TS_SIGALRM) signame = "ALRM";
10169 if (code == TS_SIGFPE) signame = "FPE";
10170 if (code == TS_SIGHUP) signame = "HUP";
10171 if (code == TS_SIGILL) signame = "ILL";
10172 if (code == TS_SIGINT) signame = "INT";
10173 if (code == TS_SIGKILL) signame = "KILL";
10174 if (code == TS_SIGPIPE) signame = "PIPE";
10175 if (code == TS_SIGQUIT) signame = "QUIT";
10176 if (code == TS_SIGSEGV) signame = "SEGV";
10177 if (code == TS_SIGTERM) signame = "TERM";
10178 if (code == TS_SIGUSR1) signame = "USR1";
10179 if (code == TS_SIGUSR2) signame = "USR2";
10180 /* The SSH-2 protocol does in principle support arbitrary named
10181 * signals, including signame@domain, but we don't support those. */
10183 /* It's a signal. */
10184 if (ssh->version == 2 && ssh->mainchan) {
10185 pktout = ssh2_chanreq_init(ssh->mainchan, "signal", NULL, NULL);
10186 ssh2_pkt_addstring(pktout, signame);
10187 ssh2_pkt_send(ssh, pktout);
10188 logeventf(ssh, "Sent signal SIG%s", signame);
10191 /* Never heard of it. Do nothing */
10196 void *new_sock_channel(void *handle, Socket s)
10198 Ssh ssh = (Ssh) handle;
10199 struct ssh_channel *c;
10200 c = snew(struct ssh_channel);
10203 ssh2_channel_init(c);
10204 c->halfopen = TRUE;
10205 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
10207 add234(ssh->channels, c);
10212 * This is called when stdout/stderr (the entity to which
10213 * from_backend sends data) manages to clear some backlog.
10215 static void ssh_unthrottle(void *handle, int bufsize)
10217 Ssh ssh = (Ssh) handle;
10220 if (ssh->version == 1) {
10221 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
10222 ssh->v1_stdout_throttling = 0;
10223 ssh_throttle_conn(ssh, -1);
10226 if (ssh->mainchan) {
10227 ssh2_set_window(ssh->mainchan,
10228 bufsize < ssh->mainchan->v.v2.locmaxwin ?
10229 ssh->mainchan->v.v2.locmaxwin - bufsize : 0);
10230 if (conf_get_int(ssh->conf, CONF_ssh_simple))
10233 buflimit = ssh->mainchan->v.v2.locmaxwin;
10234 if (ssh->mainchan->throttling_conn && bufsize <= buflimit) {
10235 ssh->mainchan->throttling_conn = 0;
10236 ssh_throttle_conn(ssh, -1);
10242 * Now process any SSH connection data that was stashed in our
10243 * queue while we were frozen.
10245 ssh_process_queued_incoming_data(ssh);
10248 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
10250 struct ssh_channel *c = (struct ssh_channel *)channel;
10252 struct Packet *pktout;
10254 logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org);
10256 if (ssh->version == 1) {
10257 send_packet(ssh, SSH1_MSG_PORT_OPEN,
10258 PKT_INT, c->localid,
10261 /* PKT_STR, <org:orgport>, */
10264 pktout = ssh2_chanopen_init(c, "direct-tcpip");
10265 ssh2_pkt_addstring(pktout, hostname);
10266 ssh2_pkt_adduint32(pktout, port);
10268 * We make up values for the originator data; partly it's
10269 * too much hassle to keep track, and partly I'm not
10270 * convinced the server should be told details like that
10271 * about my local network configuration.
10272 * The "originator IP address" is syntactically a numeric
10273 * IP address, and some servers (e.g., Tectia) get upset
10274 * if it doesn't match this syntax.
10276 ssh2_pkt_addstring(pktout, "0.0.0.0");
10277 ssh2_pkt_adduint32(pktout, 0);
10278 ssh2_pkt_send(ssh, pktout);
10282 static int ssh_connected(void *handle)
10284 Ssh ssh = (Ssh) handle;
10285 return ssh->s != NULL;
10288 static int ssh_sendok(void *handle)
10290 Ssh ssh = (Ssh) handle;
10291 return ssh->send_ok;
10294 static int ssh_ldisc(void *handle, int option)
10296 Ssh ssh = (Ssh) handle;
10297 if (option == LD_ECHO)
10298 return ssh->echoing;
10299 if (option == LD_EDIT)
10300 return ssh->editing;
10304 static void ssh_provide_ldisc(void *handle, void *ldisc)
10306 Ssh ssh = (Ssh) handle;
10307 ssh->ldisc = ldisc;
10310 static void ssh_provide_logctx(void *handle, void *logctx)
10312 Ssh ssh = (Ssh) handle;
10313 ssh->logctx = logctx;
10316 static int ssh_return_exitcode(void *handle)
10318 Ssh ssh = (Ssh) handle;
10319 if (ssh->s != NULL)
10322 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
10326 * cfg_info for SSH is the currently running version of the
10327 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10329 static int ssh_cfg_info(void *handle)
10331 Ssh ssh = (Ssh) handle;
10332 return ssh->version;
10336 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10337 * that fails. This variable is the means by which scp.c can reach
10338 * into the SSH code and find out which one it got.
10340 extern int ssh_fallback_cmd(void *handle)
10342 Ssh ssh = (Ssh) handle;
10343 return ssh->fallback_cmd;
10346 Backend ssh_backend = {
10356 ssh_return_exitcode,
10360 ssh_provide_logctx,