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, s) } *crLine = 0; sfree(s); return (z); }
443 #define crFinishFreeV(s) } *crLine = 0; 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
*, 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
*, char *data
);
469 static void ssh_pkt_addstring_data(struct Packet
*, char *data
, int len
);
470 static void ssh_pkt_addstring(struct Packet
*, 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_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 * little structure to keep track of outstanding WINDOW_ADJUSTs
600 * 2-3-4 tree storing channels.
603 Ssh ssh
; /* pointer back to main context */
604 unsigned remoteid
, localid
;
606 /* True if we opened this channel but server hasn't confirmed. */
609 * In SSH-1, this value contains four bits:
611 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
612 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
613 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
614 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
616 * A channel is completely finished with when all four bits are set.
618 * In SSH-2, the four bits mean:
620 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
621 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
622 * 4 We have received SSH2_MSG_CHANNEL_EOF.
623 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
625 * A channel is completely finished with when we have both sent
626 * and received CLOSE.
628 * The symbolic constants below use the SSH-2 terminology, which
629 * is a bit confusing in SSH-1, but we have to use _something_.
631 #define CLOSES_SENT_EOF 1
632 #define CLOSES_SENT_CLOSE 2
633 #define CLOSES_RCVD_EOF 4
634 #define CLOSES_RCVD_CLOSE 8
638 * This flag indicates that an EOF is pending on the outgoing side
639 * of the channel: that is, wherever we're getting the data for
640 * this channel has sent us some data followed by EOF. We can't
641 * actually send the EOF until we've finished sending the data, so
642 * we set this flag instead to remind us to do so once our buffer
648 * True if this channel is causing the underlying connection to be
653 struct ssh2_data_channel
{
655 unsigned remwindow
, remmaxpkt
;
656 /* locwindow is signed so we can cope with excess data. */
657 int locwindow
, locmaxwin
;
659 * remlocwin is the amount of local window that we think
660 * the remote end had available to it after it sent the
661 * last data packet or window adjust ack.
665 * These store the list of channel requests that haven't
668 struct outstanding_channel_request
*chanreq_head
, *chanreq_tail
;
669 enum { THROTTLED
, UNTHROTTLING
, UNTHROTTLED
} throttle_state
;
673 struct ssh_agent_channel
{
674 unsigned char *message
;
675 unsigned char msglen
[4];
676 unsigned lensofar
, totallen
;
678 struct ssh_x11_channel
{
681 struct ssh_pfd_channel
{
688 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
689 * use this structure in different ways, reflecting SSH-2's
690 * altogether saner approach to port forwarding.
692 * In SSH-1, you arrange a remote forwarding by sending the server
693 * the remote port number, and the local destination host:port.
694 * When a connection comes in, the server sends you back that
695 * host:port pair, and you connect to it. This is a ready-made
696 * security hole if you're not on the ball: a malicious server
697 * could send you back _any_ host:port pair, so if you trustingly
698 * connect to the address it gives you then you've just opened the
699 * entire inside of your corporate network just by connecting
700 * through it to a dodgy SSH server. Hence, we must store a list of
701 * host:port pairs we _are_ trying to forward to, and reject a
702 * connection request from the server if it's not in the list.
704 * In SSH-2, each side of the connection minds its own business and
705 * doesn't send unnecessary information to the other. You arrange a
706 * remote forwarding by sending the server just the remote port
707 * number. When a connection comes in, the server tells you which
708 * of its ports was connected to; and _you_ have to remember what
709 * local host:port pair went with that port number.
711 * Hence, in SSH-1 this structure is indexed by destination
712 * host:port pair, whereas in SSH-2 it is indexed by source port.
714 struct ssh_portfwd
; /* forward declaration */
716 struct ssh_rportfwd
{
717 unsigned sport
, dport
;
720 struct ssh_portfwd
*pfrec
;
722 #define free_rportfwd(pf) ( \
723 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
726 * Separately to the rportfwd tree (which is for looking up port
727 * open requests from the server), a tree of _these_ structures is
728 * used to keep track of all the currently open port forwardings,
729 * so that we can reconfigure in mid-session if the user requests
733 enum { DESTROY
, KEEP
, CREATE
} status
;
735 unsigned sport
, dport
;
738 struct ssh_rportfwd
*remote
;
742 #define free_portfwd(pf) ( \
743 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
744 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
747 long length
; /* length of `data' actually used */
748 long forcepad
; /* SSH-2: force padding to at least this length */
749 int type
; /* only used for incoming packets */
750 unsigned long sequence
; /* SSH-2 incoming sequence number */
751 unsigned char *data
; /* allocated storage */
752 unsigned char *body
; /* offset of payload within `data' */
753 long savedpos
; /* temporary index into `data' (for strings) */
754 long maxlen
; /* amount of storage allocated for `data' */
755 long encrypted_len
; /* for SSH-2 total-size counting */
758 * State associated with packet logging
762 struct logblank_t
*blanks
;
765 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
766 struct Packet
*pktin
);
767 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
768 struct Packet
*pktin
);
769 static void ssh1_protocol_setup(Ssh ssh
);
770 static void ssh2_protocol_setup(Ssh ssh
);
771 static void ssh_size(void *handle
, int width
, int height
);
772 static void ssh_special(void *handle
, Telnet_Special
);
773 static int ssh2_try_send(struct ssh_channel
*c
);
774 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
775 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
776 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
);
777 static int ssh_sendbuffer(void *handle
);
778 static int ssh_do_close(Ssh ssh
, int notify_exit
);
779 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
);
780 static int ssh2_pkt_getbool(struct Packet
*pkt
);
781 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
);
782 static void ssh2_timer(void *ctx
, long now
);
783 static int do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
784 struct Packet
*pktin
);
785 static void ssh2_msg_unexpected(Ssh ssh
, struct Packet
*pktin
);
787 struct rdpkt1_state_tag
{
788 long len
, pad
, biglen
, to_read
;
789 unsigned long realcrc
, gotcrc
;
793 struct Packet
*pktin
;
796 struct rdpkt2_state_tag
{
797 long len
, pad
, payload
, packetlen
, maclen
;
800 unsigned long incoming_sequence
;
801 struct Packet
*pktin
;
804 struct queued_handler
;
805 struct queued_handler
{
807 chandler_fn_t handler
;
809 struct queued_handler
*next
;
813 const struct plug_function_table
*fn
;
814 /* the above field _must_ be first in the structure */
824 unsigned char session_key
[32];
826 int v1_remote_protoflags
;
827 int v1_local_protoflags
;
828 int agentfwd_enabled
;
831 const struct ssh_cipher
*cipher
;
834 const struct ssh2_cipher
*cscipher
, *sccipher
;
835 void *cs_cipher_ctx
, *sc_cipher_ctx
;
836 const struct ssh_mac
*csmac
, *scmac
;
837 void *cs_mac_ctx
, *sc_mac_ctx
;
838 const struct ssh_compress
*cscomp
, *sccomp
;
839 void *cs_comp_ctx
, *sc_comp_ctx
;
840 const struct ssh_kex
*kex
;
841 const struct ssh_signkey
*hostkey
;
842 unsigned char v2_session_id
[SSH2_KEX_MAX_HASH_LEN
];
843 int v2_session_id_len
;
849 int echoing
, editing
;
853 int ospeed
, ispeed
; /* temporaries */
854 int term_width
, term_height
;
856 tree234
*channels
; /* indexed by local id */
857 struct ssh_channel
*mainchan
; /* primary session channel */
858 int ncmode
; /* is primary channel direct-tcpip? */
863 tree234
*rportfwds
, *portfwds
;
867 SSH_STATE_BEFORE_SIZE
,
873 int size_needed
, eof_needed
;
874 int sent_console_eof
;
875 int got_pty
; /* affects EOF behaviour on main channel */
877 struct Packet
**queue
;
878 int queuelen
, queuesize
;
880 unsigned char *deferred_send_data
;
881 int deferred_len
, deferred_size
;
884 * Gross hack: pscp will try to start SFTP but fall back to
885 * scp1 if that fails. This variable is the means by which
886 * scp.c can reach into the SSH code and find out which one it
891 bufchain banner
; /* accumulates banners during do_ssh2_authconn */
896 struct X11Display
*x11disp
;
899 int conn_throttle_count
;
902 int v1_stdout_throttling
;
903 unsigned long v2_outgoing_sequence
;
905 int ssh1_rdpkt_crstate
;
906 int ssh2_rdpkt_crstate
;
907 int ssh_gotdata_crstate
;
908 int do_ssh1_connection_crstate
;
910 void *do_ssh_init_state
;
911 void *do_ssh1_login_state
;
912 void *do_ssh2_transport_state
;
913 void *do_ssh2_authconn_state
;
915 struct rdpkt1_state_tag rdpkt1_state
;
916 struct rdpkt2_state_tag rdpkt2_state
;
918 /* SSH-1 and SSH-2 use this for different things, but both use it */
919 int protocol_initial_phase_done
;
921 void (*protocol
) (Ssh ssh
, void *vin
, int inlen
,
923 struct Packet
*(*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
926 * We maintain our own copy of a Conf structure here. That way,
927 * when we're passed a new one for reconfiguration, we can check
928 * the differences and potentially reconfigure port forwardings
929 * etc in mid-session.
934 * Values cached out of conf so as to avoid the tree234 lookup
935 * cost every time they're used.
940 * Dynamically allocated username string created during SSH
941 * login. Stored in here rather than in the coroutine state so
942 * that it'll be reliably freed if we shut down the SSH session
943 * at some unexpected moment.
948 * Used to transfer data back from async callbacks.
950 void *agent_response
;
951 int agent_response_len
;
955 * The SSH connection can be set as `frozen', meaning we are
956 * not currently accepting incoming data from the network. This
957 * is slightly more serious than setting the _socket_ as
958 * frozen, because we may already have had data passed to us
959 * from the network which we need to delay processing until
960 * after the freeze is lifted, so we also need a bufchain to
964 bufchain queued_incoming_data
;
967 * Dispatch table for packet types that we may have to deal
970 handler_fn_t packet_dispatch
[256];
973 * Queues of one-off handler functions for success/failure
974 * indications from a request.
976 struct queued_handler
*qhead
, *qtail
;
977 handler_fn_t q_saved_handler1
, q_saved_handler2
;
980 * This module deals with sending keepalives.
985 * Track incoming and outgoing data sizes and time, for
988 unsigned long incoming_data_size
, outgoing_data_size
, deferred_data_size
;
989 unsigned long max_data_size
;
991 long next_rekey
, last_rekey
;
992 char *deferred_rekey_reason
; /* points to STATIC string; don't free */
995 * Fully qualified host name, which we need if doing GSSAPI.
1001 * GSSAPI libraries for this session.
1003 struct ssh_gss_liblist
*gsslibs
;
1007 #define logevent(s) logevent(ssh->frontend, s)
1009 /* logevent, only printf-formatted. */
1010 static void logeventf(Ssh ssh
, const char *fmt
, ...)
1016 buf
= dupvprintf(fmt
, ap
);
1022 #define bombout(msg) \
1024 char *text = dupprintf msg; \
1025 ssh_do_close(ssh, FALSE); \
1027 connection_fatal(ssh->frontend, "%s", text); \
1031 /* Functions to leave bits out of the SSH packet log file. */
1033 static void dont_log_password(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1035 if (conf_get_int(ssh
->conf
, CONF_logomitpass
))
1036 pkt
->logmode
= blanktype
;
1039 static void dont_log_data(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1041 if (ssh
->logomitdata
)
1042 pkt
->logmode
= blanktype
;
1045 static void end_log_omission(Ssh ssh
, struct Packet
*pkt
)
1047 pkt
->logmode
= PKTLOG_EMIT
;
1050 /* Helper function for common bits of parsing ttymodes. */
1051 static void parse_ttymodes(Ssh ssh
,
1052 void (*do_mode
)(void *data
, char *mode
, char *val
),
1057 for (val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, NULL
, &key
);
1059 val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, key
, &key
)) {
1061 * val[0] is either 'V', indicating that an explicit value
1062 * follows it, or 'A' indicating that we should pass the
1063 * value through from the local environment via get_ttymode.
1066 val
= get_ttymode(ssh
->frontend
, key
);
1068 val
++; /* skip the 'V' */
1070 do_mode(data
, key
, val
);
1074 static int ssh_channelcmp(void *av
, void *bv
)
1076 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
1077 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1078 if (a
->localid
< b
->localid
)
1080 if (a
->localid
> b
->localid
)
1084 static int ssh_channelfind(void *av
, void *bv
)
1086 unsigned *a
= (unsigned *) av
;
1087 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1088 if (*a
< b
->localid
)
1090 if (*a
> b
->localid
)
1095 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
1097 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1098 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1100 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
1101 return i
< 0 ?
-1 : +1;
1102 if (a
->dport
> b
->dport
)
1104 if (a
->dport
< b
->dport
)
1109 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
1111 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1112 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1114 if (a
->sport
> b
->sport
)
1116 if (a
->sport
< b
->sport
)
1122 * Special form of strcmp which can cope with NULL inputs. NULL is
1123 * defined to sort before even the empty string.
1125 static int nullstrcmp(const char *a
, const char *b
)
1127 if (a
== NULL
&& b
== NULL
)
1133 return strcmp(a
, b
);
1136 static int ssh_portcmp(void *av
, void *bv
)
1138 struct ssh_portfwd
*a
= (struct ssh_portfwd
*) av
;
1139 struct ssh_portfwd
*b
= (struct ssh_portfwd
*) bv
;
1141 if (a
->type
> b
->type
)
1143 if (a
->type
< b
->type
)
1145 if (a
->addressfamily
> b
->addressfamily
)
1147 if (a
->addressfamily
< b
->addressfamily
)
1149 if ( (i
= nullstrcmp(a
->saddr
, b
->saddr
)) != 0)
1150 return i
< 0 ?
-1 : +1;
1151 if (a
->sport
> b
->sport
)
1153 if (a
->sport
< b
->sport
)
1155 if (a
->type
!= 'D') {
1156 if ( (i
= nullstrcmp(a
->daddr
, b
->daddr
)) != 0)
1157 return i
< 0 ?
-1 : +1;
1158 if (a
->dport
> b
->dport
)
1160 if (a
->dport
< b
->dport
)
1166 static int alloc_channel_id(Ssh ssh
)
1168 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
1169 unsigned low
, high
, mid
;
1171 struct ssh_channel
*c
;
1174 * First-fit allocation of channel numbers: always pick the
1175 * lowest unused one. To do this, binary-search using the
1176 * counted B-tree to find the largest channel ID which is in a
1177 * contiguous sequence from the beginning. (Precisely
1178 * everything in that sequence must have ID equal to its tree
1179 * index plus CHANNEL_NUMBER_OFFSET.)
1181 tsize
= count234(ssh
->channels
);
1185 while (high
- low
> 1) {
1186 mid
= (high
+ low
) / 2;
1187 c
= index234(ssh
->channels
, mid
);
1188 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
1189 low
= mid
; /* this one is fine */
1191 high
= mid
; /* this one is past it */
1194 * Now low points to either -1, or the tree index of the
1195 * largest ID in the initial sequence.
1198 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1199 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
1201 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1204 static void c_write_stderr(int trusted
, const char *buf
, int len
)
1207 for (i
= 0; i
< len
; i
++)
1208 if (buf
[i
] != '\r' && (trusted
|| buf
[i
] == '\n' || (buf
[i
] & 0x60)))
1209 fputc(buf
[i
], stderr
);
1212 static void c_write(Ssh ssh
, const char *buf
, int len
)
1214 if (flags
& FLAG_STDERR
)
1215 c_write_stderr(1, buf
, len
);
1217 from_backend(ssh
->frontend
, 1, buf
, len
);
1220 static void c_write_untrusted(Ssh ssh
, const char *buf
, int len
)
1222 if (flags
& FLAG_STDERR
)
1223 c_write_stderr(0, buf
, len
);
1225 from_backend_untrusted(ssh
->frontend
, buf
, len
);
1228 static void c_write_str(Ssh ssh
, const char *buf
)
1230 c_write(ssh
, buf
, strlen(buf
));
1233 static void ssh_free_packet(struct Packet
*pkt
)
1238 static struct Packet
*ssh_new_packet(void)
1240 struct Packet
*pkt
= snew(struct Packet
);
1242 pkt
->body
= pkt
->data
= NULL
;
1244 pkt
->logmode
= PKTLOG_EMIT
;
1252 * Collect incoming data in the incoming packet buffer.
1253 * Decipher and verify the packet when it is completely read.
1254 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1255 * Update the *data and *datalen variables.
1256 * Return a Packet structure when a packet is completed.
1258 static struct Packet
*ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1260 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
1262 crBegin(ssh
->ssh1_rdpkt_crstate
);
1264 st
->pktin
= ssh_new_packet();
1266 st
->pktin
->type
= 0;
1267 st
->pktin
->length
= 0;
1269 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
1270 while ((*datalen
) == 0)
1272 st
->len
= (st
->len
<< 8) + **data
;
1273 (*data
)++, (*datalen
)--;
1276 st
->pad
= 8 - (st
->len
% 8);
1277 st
->biglen
= st
->len
+ st
->pad
;
1278 st
->pktin
->length
= st
->len
- 5;
1280 if (st
->biglen
< 0) {
1281 bombout(("Extremely large packet length from server suggests"
1282 " data stream corruption"));
1283 ssh_free_packet(st
->pktin
);
1287 st
->pktin
->maxlen
= st
->biglen
;
1288 st
->pktin
->data
= snewn(st
->biglen
+ APIEXTRA
, unsigned char);
1290 st
->to_read
= st
->biglen
;
1291 st
->p
= st
->pktin
->data
;
1292 while (st
->to_read
> 0) {
1293 st
->chunk
= st
->to_read
;
1294 while ((*datalen
) == 0)
1296 if (st
->chunk
> (*datalen
))
1297 st
->chunk
= (*datalen
);
1298 memcpy(st
->p
, *data
, st
->chunk
);
1300 *datalen
-= st
->chunk
;
1302 st
->to_read
-= st
->chunk
;
1305 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, st
->pktin
->data
,
1306 st
->biglen
, NULL
)) {
1307 bombout(("Network attack (CRC compensation) detected!"));
1308 ssh_free_packet(st
->pktin
);
1313 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, st
->pktin
->data
, st
->biglen
);
1315 st
->realcrc
= crc32_compute(st
->pktin
->data
, st
->biglen
- 4);
1316 st
->gotcrc
= GET_32BIT(st
->pktin
->data
+ st
->biglen
- 4);
1317 if (st
->gotcrc
!= st
->realcrc
) {
1318 bombout(("Incorrect CRC received on packet"));
1319 ssh_free_packet(st
->pktin
);
1323 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1324 st
->pktin
->savedpos
= 0;
1326 if (ssh
->v1_compressing
) {
1327 unsigned char *decompblk
;
1329 if (!zlib_decompress_block(ssh
->sc_comp_ctx
,
1330 st
->pktin
->body
- 1, st
->pktin
->length
+ 1,
1331 &decompblk
, &decomplen
)) {
1332 bombout(("Zlib decompression encountered invalid data"));
1333 ssh_free_packet(st
->pktin
);
1337 if (st
->pktin
->maxlen
< st
->pad
+ decomplen
) {
1338 st
->pktin
->maxlen
= st
->pad
+ decomplen
;
1339 st
->pktin
->data
= sresize(st
->pktin
->data
,
1340 st
->pktin
->maxlen
+ APIEXTRA
,
1342 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1345 memcpy(st
->pktin
->body
- 1, decompblk
, decomplen
);
1347 st
->pktin
->length
= decomplen
- 1;
1350 st
->pktin
->type
= st
->pktin
->body
[-1];
1353 * Log incoming packet, possibly omitting sensitive fields.
1357 struct logblank_t blank
;
1358 if (ssh
->logomitdata
) {
1359 int do_blank
= FALSE
, blank_prefix
= 0;
1360 /* "Session data" packets - omit the data field */
1361 if ((st
->pktin
->type
== SSH1_SMSG_STDOUT_DATA
) ||
1362 (st
->pktin
->type
== SSH1_SMSG_STDERR_DATA
)) {
1363 do_blank
= TRUE
; blank_prefix
= 4;
1364 } else if (st
->pktin
->type
== SSH1_MSG_CHANNEL_DATA
) {
1365 do_blank
= TRUE
; blank_prefix
= 8;
1368 blank
.offset
= blank_prefix
;
1369 blank
.len
= st
->pktin
->length
;
1370 blank
.type
= PKTLOG_OMIT
;
1374 log_packet(ssh
->logctx
,
1375 PKT_INCOMING
, st
->pktin
->type
,
1376 ssh1_pkt_type(st
->pktin
->type
),
1377 st
->pktin
->body
, st
->pktin
->length
,
1378 nblanks
, &blank
, NULL
);
1381 crFinish(st
->pktin
);
1384 static struct Packet
*ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1386 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
1388 crBegin(ssh
->ssh2_rdpkt_crstate
);
1390 st
->pktin
= ssh_new_packet();
1392 st
->pktin
->type
= 0;
1393 st
->pktin
->length
= 0;
1395 st
->cipherblk
= ssh
->sccipher
->blksize
;
1398 if (st
->cipherblk
< 8)
1400 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
1402 if (ssh
->sccipher
&& (ssh
->sccipher
->flags
& SSH_CIPHER_IS_CBC
) &&
1405 * When dealing with a CBC-mode cipher, we want to avoid the
1406 * possibility of an attacker's tweaking the ciphertext stream
1407 * so as to cause us to feed the same block to the block
1408 * cipher more than once and thus leak information
1409 * (VU#958563). The way we do this is not to take any
1410 * decisions on the basis of anything we've decrypted until
1411 * we've verified it with a MAC. That includes the packet
1412 * length, so we just read data and check the MAC repeatedly,
1413 * and when the MAC passes, see if the length we've got is
1417 /* May as well allocate the whole lot now. */
1418 st
->pktin
->data
= snewn(OUR_V2_PACKETLIMIT
+ st
->maclen
+ APIEXTRA
,
1421 /* Read an amount corresponding to the MAC. */
1422 for (st
->i
= 0; st
->i
< st
->maclen
; st
->i
++) {
1423 while ((*datalen
) == 0)
1425 st
->pktin
->data
[st
->i
] = *(*data
)++;
1431 unsigned char seq
[4];
1432 ssh
->scmac
->start(ssh
->sc_mac_ctx
);
1433 PUT_32BIT(seq
, st
->incoming_sequence
);
1434 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
, seq
, 4);
1437 for (;;) { /* Once around this loop per cipher block. */
1438 /* Read another cipher-block's worth, and tack it onto the end. */
1439 for (st
->i
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1440 while ((*datalen
) == 0)
1442 st
->pktin
->data
[st
->packetlen
+st
->maclen
+st
->i
] = *(*data
)++;
1445 /* Decrypt one more block (a little further back in the stream). */
1446 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1447 st
->pktin
->data
+ st
->packetlen
,
1449 /* Feed that block to the MAC. */
1450 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
,
1451 st
->pktin
->data
+ st
->packetlen
, st
->cipherblk
);
1452 st
->packetlen
+= st
->cipherblk
;
1453 /* See if that gives us a valid packet. */
1454 if (ssh
->scmac
->verresult(ssh
->sc_mac_ctx
,
1455 st
->pktin
->data
+ st
->packetlen
) &&
1456 (st
->len
= GET_32BIT(st
->pktin
->data
)) + 4 == st
->packetlen
)
1458 if (st
->packetlen
>= OUR_V2_PACKETLIMIT
) {
1459 bombout(("No valid incoming packet found"));
1460 ssh_free_packet(st
->pktin
);
1464 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1465 st
->pktin
->data
= sresize(st
->pktin
->data
,
1466 st
->pktin
->maxlen
+ APIEXTRA
,
1469 st
->pktin
->data
= snewn(st
->cipherblk
+ APIEXTRA
, unsigned char);
1472 * Acquire and decrypt the first block of the packet. This will
1473 * contain the length and padding details.
1475 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1476 while ((*datalen
) == 0)
1478 st
->pktin
->data
[st
->i
] = *(*data
)++;
1483 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1484 st
->pktin
->data
, st
->cipherblk
);
1487 * Now get the length figure.
1489 st
->len
= GET_32BIT(st
->pktin
->data
);
1492 * _Completely_ silly lengths should be stomped on before they
1493 * do us any more damage.
1495 if (st
->len
< 0 || st
->len
> OUR_V2_PACKETLIMIT
||
1496 (st
->len
+ 4) % st
->cipherblk
!= 0) {
1497 bombout(("Incoming packet was garbled on decryption"));
1498 ssh_free_packet(st
->pktin
);
1503 * So now we can work out the total packet length.
1505 st
->packetlen
= st
->len
+ 4;
1508 * Allocate memory for the rest of the packet.
1510 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1511 st
->pktin
->data
= sresize(st
->pktin
->data
,
1512 st
->pktin
->maxlen
+ APIEXTRA
,
1516 * Read and decrypt the remainder of the packet.
1518 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
1520 while ((*datalen
) == 0)
1522 st
->pktin
->data
[st
->i
] = *(*data
)++;
1525 /* Decrypt everything _except_ the MAC. */
1527 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1528 st
->pktin
->data
+ st
->cipherblk
,
1529 st
->packetlen
- st
->cipherblk
);
1535 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, st
->pktin
->data
,
1536 st
->len
+ 4, st
->incoming_sequence
)) {
1537 bombout(("Incorrect MAC received on packet"));
1538 ssh_free_packet(st
->pktin
);
1542 /* Get and sanity-check the amount of random padding. */
1543 st
->pad
= st
->pktin
->data
[4];
1544 if (st
->pad
< 4 || st
->len
- st
->pad
< 1) {
1545 bombout(("Invalid padding length on received packet"));
1546 ssh_free_packet(st
->pktin
);
1550 * This enables us to deduce the payload length.
1552 st
->payload
= st
->len
- st
->pad
- 1;
1554 st
->pktin
->length
= st
->payload
+ 5;
1555 st
->pktin
->encrypted_len
= st
->packetlen
;
1557 st
->pktin
->sequence
= st
->incoming_sequence
++;
1560 * Decompress packet payload.
1563 unsigned char *newpayload
;
1566 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1567 st
->pktin
->data
+ 5, st
->pktin
->length
- 5,
1568 &newpayload
, &newlen
)) {
1569 if (st
->pktin
->maxlen
< newlen
+ 5) {
1570 st
->pktin
->maxlen
= newlen
+ 5;
1571 st
->pktin
->data
= sresize(st
->pktin
->data
,
1572 st
->pktin
->maxlen
+ APIEXTRA
,
1575 st
->pktin
->length
= 5 + newlen
;
1576 memcpy(st
->pktin
->data
+ 5, newpayload
, newlen
);
1581 st
->pktin
->savedpos
= 6;
1582 st
->pktin
->body
= st
->pktin
->data
;
1583 st
->pktin
->type
= st
->pktin
->data
[5];
1586 * Log incoming packet, possibly omitting sensitive fields.
1590 struct logblank_t blank
;
1591 if (ssh
->logomitdata
) {
1592 int do_blank
= FALSE
, blank_prefix
= 0;
1593 /* "Session data" packets - omit the data field */
1594 if (st
->pktin
->type
== SSH2_MSG_CHANNEL_DATA
) {
1595 do_blank
= TRUE
; blank_prefix
= 8;
1596 } else if (st
->pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1597 do_blank
= TRUE
; blank_prefix
= 12;
1600 blank
.offset
= blank_prefix
;
1601 blank
.len
= (st
->pktin
->length
-6) - blank_prefix
;
1602 blank
.type
= PKTLOG_OMIT
;
1606 log_packet(ssh
->logctx
, PKT_INCOMING
, st
->pktin
->type
,
1607 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
1609 st
->pktin
->data
+6, st
->pktin
->length
-6,
1610 nblanks
, &blank
, &st
->pktin
->sequence
);
1613 crFinish(st
->pktin
);
1616 static int s_wrpkt_prepare(Ssh ssh
, struct Packet
*pkt
, int *offset_p
)
1618 int pad
, biglen
, i
, pktoffs
;
1622 * XXX various versions of SC (including 8.8.4) screw up the
1623 * register allocation in this function and use the same register
1624 * (D6) for len and as a temporary, with predictable results. The
1625 * following sledgehammer prevents this.
1632 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[12],
1633 ssh1_pkt_type(pkt
->data
[12]),
1634 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1635 pkt
->nblanks
, pkt
->blanks
, NULL
);
1636 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1639 if (ssh
->v1_compressing
) {
1640 unsigned char *compblk
;
1642 zlib_compress_block(ssh
->cs_comp_ctx
,
1643 pkt
->data
+ 12, pkt
->length
- 12,
1644 &compblk
, &complen
);
1645 ssh_pkt_ensure(pkt
, complen
+ 2); /* just in case it's got bigger */
1646 memcpy(pkt
->data
+ 12, compblk
, complen
);
1648 pkt
->length
= complen
+ 12;
1651 ssh_pkt_ensure(pkt
, pkt
->length
+ 4); /* space for CRC */
1653 len
= pkt
->length
- 4 - 8; /* len(type+data+CRC) */
1654 pad
= 8 - (len
% 8);
1656 biglen
= len
+ pad
; /* len(padding+type+data+CRC) */
1658 for (i
= pktoffs
; i
< 4+8; i
++)
1659 pkt
->data
[i
] = random_byte();
1660 crc
= crc32_compute(pkt
->data
+ pktoffs
+ 4, biglen
- 4); /* all ex len */
1661 PUT_32BIT(pkt
->data
+ pktoffs
+ 4 + biglen
- 4, crc
);
1662 PUT_32BIT(pkt
->data
+ pktoffs
, len
);
1665 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
,
1666 pkt
->data
+ pktoffs
+ 4, biglen
);
1668 if (offset_p
) *offset_p
= pktoffs
;
1669 return biglen
+ 4; /* len(length+padding+type+data+CRC) */
1672 static int s_write(Ssh ssh
, void *data
, int len
)
1675 log_packet(ssh
->logctx
, PKT_OUTGOING
, -1, NULL
, data
, len
,
1677 return sk_write(ssh
->s
, (char *)data
, len
);
1680 static void s_wrpkt(Ssh ssh
, struct Packet
*pkt
)
1682 int len
, backlog
, offset
;
1683 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1684 backlog
= s_write(ssh
, pkt
->data
+ offset
, len
);
1685 if (backlog
> SSH_MAX_BACKLOG
)
1686 ssh_throttle_all(ssh
, 1, backlog
);
1687 ssh_free_packet(pkt
);
1690 static void s_wrpkt_defer(Ssh ssh
, struct Packet
*pkt
)
1693 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1694 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1695 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1696 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1700 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
,
1701 pkt
->data
+ offset
, len
);
1702 ssh
->deferred_len
+= len
;
1703 ssh_free_packet(pkt
);
1707 * Construct a SSH-1 packet with the specified contents.
1708 * (This all-at-once interface used to be the only one, but now SSH-1
1709 * packets can also be constructed incrementally.)
1711 static struct Packet
*construct_packet(Ssh ssh
, int pkttype
, va_list ap
)
1717 pkt
= ssh1_pkt_init(pkttype
);
1719 while ((argtype
= va_arg(ap
, int)) != PKT_END
) {
1720 unsigned char *argp
, argchar
;
1722 unsigned long argint
;
1725 /* Actual fields in the packet */
1727 argint
= va_arg(ap
, int);
1728 ssh_pkt_adduint32(pkt
, argint
);
1731 argchar
= (unsigned char) va_arg(ap
, int);
1732 ssh_pkt_addbyte(pkt
, argchar
);
1735 argp
= va_arg(ap
, unsigned char *);
1736 arglen
= va_arg(ap
, int);
1737 ssh_pkt_adddata(pkt
, argp
, arglen
);
1740 sargp
= va_arg(ap
, char *);
1741 ssh_pkt_addstring(pkt
, sargp
);
1744 bn
= va_arg(ap
, Bignum
);
1745 ssh1_pkt_addmp(pkt
, bn
);
1747 /* Tokens for modifications to packet logging */
1749 dont_log_password(ssh
, pkt
, PKTLOG_BLANK
);
1752 dont_log_data(ssh
, pkt
, PKTLOG_OMIT
);
1755 end_log_omission(ssh
, pkt
);
1763 static void send_packet(Ssh ssh
, int pkttype
, ...)
1767 va_start(ap
, pkttype
);
1768 pkt
= construct_packet(ssh
, pkttype
, ap
);
1773 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1777 va_start(ap
, pkttype
);
1778 pkt
= construct_packet(ssh
, pkttype
, ap
);
1780 s_wrpkt_defer(ssh
, pkt
);
1783 static int ssh_versioncmp(char *a
, char *b
)
1786 unsigned long av
, bv
;
1788 av
= strtoul(a
, &ae
, 10);
1789 bv
= strtoul(b
, &be
, 10);
1791 return (av
< bv ?
-1 : +1);
1796 av
= strtoul(ae
, &ae
, 10);
1797 bv
= strtoul(be
, &be
, 10);
1799 return (av
< bv ?
-1 : +1);
1804 * Utility routines for putting an SSH-protocol `string' and
1805 * `uint32' into a hash state.
1807 static void hash_string(const struct ssh_hash
*h
, void *s
, void *str
, int len
)
1809 unsigned char lenblk
[4];
1810 PUT_32BIT(lenblk
, len
);
1811 h
->bytes(s
, lenblk
, 4);
1812 h
->bytes(s
, str
, len
);
1815 static void hash_uint32(const struct ssh_hash
*h
, void *s
, unsigned i
)
1817 unsigned char intblk
[4];
1818 PUT_32BIT(intblk
, i
);
1819 h
->bytes(s
, intblk
, 4);
1823 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1825 static void ssh_pkt_ensure(struct Packet
*pkt
, int length
)
1827 if (pkt
->maxlen
< length
) {
1828 unsigned char *body
= pkt
->body
;
1829 int offset
= body ? body
- pkt
->data
: 0;
1830 pkt
->maxlen
= length
+ 256;
1831 pkt
->data
= sresize(pkt
->data
, pkt
->maxlen
+ APIEXTRA
, unsigned char);
1832 if (body
) pkt
->body
= pkt
->data
+ offset
;
1835 static void ssh_pkt_adddata(struct Packet
*pkt
, void *data
, int len
)
1837 if (pkt
->logmode
!= PKTLOG_EMIT
) {
1839 pkt
->blanks
= sresize(pkt
->blanks
, pkt
->nblanks
, struct logblank_t
);
1841 pkt
->blanks
[pkt
->nblanks
-1].offset
= pkt
->length
-
1842 (pkt
->body
- pkt
->data
);
1843 pkt
->blanks
[pkt
->nblanks
-1].len
= len
;
1844 pkt
->blanks
[pkt
->nblanks
-1].type
= pkt
->logmode
;
1847 ssh_pkt_ensure(pkt
, pkt
->length
);
1848 memcpy(pkt
->data
+ pkt
->length
- len
, data
, len
);
1850 static void ssh_pkt_addbyte(struct Packet
*pkt
, unsigned char byte
)
1852 ssh_pkt_adddata(pkt
, &byte
, 1);
1854 static void ssh2_pkt_addbool(struct Packet
*pkt
, unsigned char value
)
1856 ssh_pkt_adddata(pkt
, &value
, 1);
1858 static void ssh_pkt_adduint32(struct Packet
*pkt
, unsigned long value
)
1861 PUT_32BIT(x
, value
);
1862 ssh_pkt_adddata(pkt
, x
, 4);
1864 static void ssh_pkt_addstring_start(struct Packet
*pkt
)
1866 ssh_pkt_adduint32(pkt
, 0);
1867 pkt
->savedpos
= pkt
->length
;
1869 static void ssh_pkt_addstring_str(struct Packet
*pkt
, char *data
)
1871 ssh_pkt_adddata(pkt
, data
, strlen(data
));
1872 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1874 static void ssh_pkt_addstring_data(struct Packet
*pkt
, char *data
, int len
)
1876 ssh_pkt_adddata(pkt
, data
, len
);
1877 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1879 static void ssh_pkt_addstring(struct Packet
*pkt
, char *data
)
1881 ssh_pkt_addstring_start(pkt
);
1882 ssh_pkt_addstring_str(pkt
, data
);
1884 static void ssh1_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1886 int len
= ssh1_bignum_length(b
);
1887 unsigned char *data
= snewn(len
, unsigned char);
1888 (void) ssh1_write_bignum(data
, b
);
1889 ssh_pkt_adddata(pkt
, data
, len
);
1892 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1895 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1896 p
= snewn(n
+ 1, unsigned char);
1898 for (i
= 1; i
<= n
; i
++)
1899 p
[i
] = bignum_byte(b
, n
- i
);
1901 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1903 memmove(p
, p
+ i
, n
+ 1 - i
);
1907 static void ssh2_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1911 p
= ssh2_mpint_fmt(b
, &len
);
1912 ssh_pkt_addstring_start(pkt
);
1913 ssh_pkt_addstring_data(pkt
, (char *)p
, len
);
1917 static struct Packet
*ssh1_pkt_init(int pkt_type
)
1919 struct Packet
*pkt
= ssh_new_packet();
1920 pkt
->length
= 4 + 8; /* space for length + max padding */
1921 ssh_pkt_addbyte(pkt
, pkt_type
);
1922 pkt
->body
= pkt
->data
+ pkt
->length
;
1926 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1927 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1928 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1929 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1930 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1931 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1932 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1933 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1934 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1936 static struct Packet
*ssh2_pkt_init(int pkt_type
)
1938 struct Packet
*pkt
= ssh_new_packet();
1939 pkt
->length
= 5; /* space for packet length + padding length */
1941 ssh_pkt_addbyte(pkt
, (unsigned char) pkt_type
);
1942 pkt
->body
= pkt
->data
+ pkt
->length
; /* after packet type */
1947 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1948 * put the MAC on it. Final packet, ready to be sent, is stored in
1949 * pkt->data. Total length is returned.
1951 static int ssh2_pkt_construct(Ssh ssh
, struct Packet
*pkt
)
1953 int cipherblk
, maclen
, padding
, i
;
1956 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[5],
1957 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
, pkt
->data
[5]),
1958 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1959 pkt
->nblanks
, pkt
->blanks
, &ssh
->v2_outgoing_sequence
);
1960 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1964 * Compress packet payload.
1967 unsigned char *newpayload
;
1970 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, pkt
->data
+ 5,
1972 &newpayload
, &newlen
)) {
1974 ssh2_pkt_adddata(pkt
, newpayload
, newlen
);
1980 * Add padding. At least four bytes, and must also bring total
1981 * length (minus MAC) up to a multiple of the block size.
1982 * If pkt->forcepad is set, make sure the packet is at least that size
1985 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1986 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1988 if (pkt
->length
+ padding
< pkt
->forcepad
)
1989 padding
= pkt
->forcepad
- pkt
->length
;
1991 (cipherblk
- (pkt
->length
+ padding
) % cipherblk
) % cipherblk
;
1992 assert(padding
<= 255);
1993 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1994 ssh2_pkt_ensure(pkt
, pkt
->length
+ padding
+ maclen
);
1995 pkt
->data
[4] = padding
;
1996 for (i
= 0; i
< padding
; i
++)
1997 pkt
->data
[pkt
->length
+ i
] = random_byte();
1998 PUT_32BIT(pkt
->data
, pkt
->length
+ padding
- 4);
2000 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, pkt
->data
,
2001 pkt
->length
+ padding
,
2002 ssh
->v2_outgoing_sequence
);
2003 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
2006 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
2007 pkt
->data
, pkt
->length
+ padding
);
2009 pkt
->encrypted_len
= pkt
->length
+ padding
;
2011 /* Ready-to-send packet starts at pkt->data. We return length. */
2012 return pkt
->length
+ padding
+ maclen
;
2016 * Routines called from the main SSH code to send packets. There
2017 * are quite a few of these, because we have two separate
2018 * mechanisms for delaying the sending of packets:
2020 * - In order to send an IGNORE message and a password message in
2021 * a single fixed-length blob, we require the ability to
2022 * concatenate the encrypted forms of those two packets _into_ a
2023 * single blob and then pass it to our <network.h> transport
2024 * layer in one go. Hence, there's a deferment mechanism which
2025 * works after packet encryption.
2027 * - In order to avoid sending any connection-layer messages
2028 * during repeat key exchange, we have to queue up any such
2029 * outgoing messages _before_ they are encrypted (and in
2030 * particular before they're allocated sequence numbers), and
2031 * then send them once we've finished.
2033 * I call these mechanisms `defer' and `queue' respectively, so as
2034 * to distinguish them reasonably easily.
2036 * The functions send_noqueue() and defer_noqueue() free the packet
2037 * structure they are passed. Every outgoing packet goes through
2038 * precisely one of these functions in its life; packets passed to
2039 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2040 * these or get queued, and then when the queue is later emptied
2041 * the packets are all passed to defer_noqueue().
2043 * When using a CBC-mode cipher, it's necessary to ensure that an
2044 * attacker can't provide data to be encrypted using an IV that they
2045 * know. We ensure this by prefixing each packet that might contain
2046 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2047 * mechanism, so in this case send_noqueue() ends up redirecting to
2048 * defer_noqueue(). If you don't like this inefficiency, don't use
2052 static void ssh2_pkt_defer_noqueue(Ssh
, struct Packet
*, int);
2053 static void ssh_pkt_defersend(Ssh
);
2056 * Send an SSH-2 packet immediately, without queuing or deferring.
2058 static void ssh2_pkt_send_noqueue(Ssh ssh
, struct Packet
*pkt
)
2062 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
)) {
2063 /* We need to send two packets, so use the deferral mechanism. */
2064 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2065 ssh_pkt_defersend(ssh
);
2068 len
= ssh2_pkt_construct(ssh
, pkt
);
2069 backlog
= s_write(ssh
, pkt
->data
, len
);
2070 if (backlog
> SSH_MAX_BACKLOG
)
2071 ssh_throttle_all(ssh
, 1, backlog
);
2073 ssh
->outgoing_data_size
+= pkt
->encrypted_len
;
2074 if (!ssh
->kex_in_progress
&&
2075 ssh
->max_data_size
!= 0 &&
2076 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2077 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2079 ssh_free_packet(pkt
);
2083 * Defer an SSH-2 packet.
2085 static void ssh2_pkt_defer_noqueue(Ssh ssh
, struct Packet
*pkt
, int noignore
)
2088 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
) &&
2089 ssh
->deferred_len
== 0 && !noignore
&&
2090 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2092 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2093 * get encrypted with a known IV.
2095 struct Packet
*ipkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2096 ssh2_pkt_addstring_start(ipkt
);
2097 ssh2_pkt_defer_noqueue(ssh
, ipkt
, TRUE
);
2099 len
= ssh2_pkt_construct(ssh
, pkt
);
2100 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
2101 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
2102 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
2106 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, pkt
->data
, len
);
2107 ssh
->deferred_len
+= len
;
2108 ssh
->deferred_data_size
+= pkt
->encrypted_len
;
2109 ssh_free_packet(pkt
);
2113 * Queue an SSH-2 packet.
2115 static void ssh2_pkt_queue(Ssh ssh
, struct Packet
*pkt
)
2117 assert(ssh
->queueing
);
2119 if (ssh
->queuelen
>= ssh
->queuesize
) {
2120 ssh
->queuesize
= ssh
->queuelen
+ 32;
2121 ssh
->queue
= sresize(ssh
->queue
, ssh
->queuesize
, struct Packet
*);
2124 ssh
->queue
[ssh
->queuelen
++] = pkt
;
2128 * Either queue or send a packet, depending on whether queueing is
2131 static void ssh2_pkt_send(Ssh ssh
, struct Packet
*pkt
)
2134 ssh2_pkt_queue(ssh
, pkt
);
2136 ssh2_pkt_send_noqueue(ssh
, pkt
);
2140 * Either queue or defer a packet, depending on whether queueing is
2143 static void ssh2_pkt_defer(Ssh ssh
, struct Packet
*pkt
)
2146 ssh2_pkt_queue(ssh
, pkt
);
2148 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2152 * Send the whole deferred data block constructed by
2153 * ssh2_pkt_defer() or SSH-1's defer_packet().
2155 * The expected use of the defer mechanism is that you call
2156 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2157 * not currently queueing, this simply sets up deferred_send_data
2158 * and then sends it. If we _are_ currently queueing, the calls to
2159 * ssh2_pkt_defer() put the deferred packets on to the queue
2160 * instead, and therefore ssh_pkt_defersend() has no deferred data
2161 * to send. Hence, there's no need to make it conditional on
2164 static void ssh_pkt_defersend(Ssh ssh
)
2167 backlog
= s_write(ssh
, ssh
->deferred_send_data
, ssh
->deferred_len
);
2168 ssh
->deferred_len
= ssh
->deferred_size
= 0;
2169 sfree(ssh
->deferred_send_data
);
2170 ssh
->deferred_send_data
= NULL
;
2171 if (backlog
> SSH_MAX_BACKLOG
)
2172 ssh_throttle_all(ssh
, 1, backlog
);
2174 ssh
->outgoing_data_size
+= ssh
->deferred_data_size
;
2175 if (!ssh
->kex_in_progress
&&
2176 ssh
->max_data_size
!= 0 &&
2177 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2178 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2179 ssh
->deferred_data_size
= 0;
2183 * Send a packet whose length needs to be disguised (typically
2184 * passwords or keyboard-interactive responses).
2186 static void ssh2_pkt_send_with_padding(Ssh ssh
, struct Packet
*pkt
,
2192 * The simplest way to do this is to adjust the
2193 * variable-length padding field in the outgoing packet.
2195 * Currently compiled out, because some Cisco SSH servers
2196 * don't like excessively padded packets (bah, why's it
2199 pkt
->forcepad
= padsize
;
2200 ssh2_pkt_send(ssh
, pkt
);
2205 * If we can't do that, however, an alternative approach is
2206 * to use the pkt_defer mechanism to bundle the packet
2207 * tightly together with an SSH_MSG_IGNORE such that their
2208 * combined length is a constant. So first we construct the
2209 * final form of this packet and defer its sending.
2211 ssh2_pkt_defer(ssh
, pkt
);
2214 * Now construct an SSH_MSG_IGNORE which includes a string
2215 * that's an exact multiple of the cipher block size. (If
2216 * the cipher is NULL so that the block size is
2217 * unavailable, we don't do this trick at all, because we
2218 * gain nothing by it.)
2220 if (ssh
->cscipher
&&
2221 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2224 stringlen
= (256 - ssh
->deferred_len
);
2225 stringlen
+= ssh
->cscipher
->blksize
- 1;
2226 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
2229 * Temporarily disable actual compression, so we
2230 * can guarantee to get this string exactly the
2231 * length we want it. The compression-disabling
2232 * routine should return an integer indicating how
2233 * many bytes we should adjust our string length
2237 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
2239 pkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2240 ssh2_pkt_addstring_start(pkt
);
2241 for (i
= 0; i
< stringlen
; i
++) {
2242 char c
= (char) random_byte();
2243 ssh2_pkt_addstring_data(pkt
, &c
, 1);
2245 ssh2_pkt_defer(ssh
, pkt
);
2247 ssh_pkt_defersend(ssh
);
2252 * Send all queued SSH-2 packets. We send them by means of
2253 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2254 * packets that needed to be lumped together.
2256 static void ssh2_pkt_queuesend(Ssh ssh
)
2260 assert(!ssh
->queueing
);
2262 for (i
= 0; i
< ssh
->queuelen
; i
++)
2263 ssh2_pkt_defer_noqueue(ssh
, ssh
->queue
[i
], FALSE
);
2266 ssh_pkt_defersend(ssh
);
2270 void bndebug(char *string
, Bignum b
)
2274 p
= ssh2_mpint_fmt(b
, &len
);
2275 debug(("%s", string
));
2276 for (i
= 0; i
< len
; i
++)
2277 debug((" %02x", p
[i
]));
2283 static void hash_mpint(const struct ssh_hash
*h
, void *s
, Bignum b
)
2287 p
= ssh2_mpint_fmt(b
, &len
);
2288 hash_string(h
, s
, p
, len
);
2293 * Packet decode functions for both SSH-1 and SSH-2.
2295 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
)
2297 unsigned long value
;
2298 if (pkt
->length
- pkt
->savedpos
< 4)
2299 return 0; /* arrgh, no way to decline (FIXME?) */
2300 value
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2304 static int ssh2_pkt_getbool(struct Packet
*pkt
)
2306 unsigned long value
;
2307 if (pkt
->length
- pkt
->savedpos
< 1)
2308 return 0; /* arrgh, no way to decline (FIXME?) */
2309 value
= pkt
->body
[pkt
->savedpos
] != 0;
2313 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
)
2318 if (pkt
->length
- pkt
->savedpos
< 4)
2320 len
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2325 if (pkt
->length
- pkt
->savedpos
< *length
)
2327 *p
= (char *)(pkt
->body
+ pkt
->savedpos
);
2328 pkt
->savedpos
+= *length
;
2330 static void *ssh_pkt_getdata(struct Packet
*pkt
, int length
)
2332 if (pkt
->length
- pkt
->savedpos
< length
)
2334 pkt
->savedpos
+= length
;
2335 return pkt
->body
+ (pkt
->savedpos
- length
);
2337 static int ssh1_pkt_getrsakey(struct Packet
*pkt
, struct RSAKey
*key
,
2338 unsigned char **keystr
)
2342 j
= makekey(pkt
->body
+ pkt
->savedpos
,
2343 pkt
->length
- pkt
->savedpos
,
2350 assert(pkt
->savedpos
< pkt
->length
);
2354 static Bignum
ssh1_pkt_getmp(struct Packet
*pkt
)
2359 j
= ssh1_read_bignum(pkt
->body
+ pkt
->savedpos
,
2360 pkt
->length
- pkt
->savedpos
, &b
);
2368 static Bignum
ssh2_pkt_getmp(struct Packet
*pkt
)
2374 ssh_pkt_getstring(pkt
, &p
, &length
);
2379 b
= bignum_from_bytes((unsigned char *)p
, length
);
2384 * Helper function to add an SSH-2 signature blob to a packet.
2385 * Expects to be shown the public key blob as well as the signature
2386 * blob. Normally works just like ssh2_pkt_addstring, but will
2387 * fiddle with the signature packet if necessary for
2388 * BUG_SSH2_RSA_PADDING.
2390 static void ssh2_add_sigblob(Ssh ssh
, struct Packet
*pkt
,
2391 void *pkblob_v
, int pkblob_len
,
2392 void *sigblob_v
, int sigblob_len
)
2394 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
2395 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
2397 /* dmemdump(pkblob, pkblob_len); */
2398 /* dmemdump(sigblob, sigblob_len); */
2401 * See if this is in fact an ssh-rsa signature and a buggy
2402 * server; otherwise we can just do this the easy way.
2404 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
2405 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
2406 int pos
, len
, siglen
;
2409 * Find the byte length of the modulus.
2412 pos
= 4+7; /* skip over "ssh-rsa" */
2413 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
2414 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
2415 pos
+= 4; /* find modulus itself */
2416 while (len
> 0 && pkblob
[pos
] == 0)
2418 /* debug(("modulus length is %d\n", len)); */
2421 * Now find the signature integer.
2423 pos
= 4+7; /* skip over "ssh-rsa" */
2424 siglen
= GET_32BIT(sigblob
+pos
);
2425 /* debug(("signature length is %d\n", siglen)); */
2427 if (len
!= siglen
) {
2428 unsigned char newlen
[4];
2429 ssh2_pkt_addstring_start(pkt
);
2430 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, pos
);
2431 /* dmemdump(sigblob, pos); */
2432 pos
+= 4; /* point to start of actual sig */
2433 PUT_32BIT(newlen
, len
);
2434 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 4);
2435 /* dmemdump(newlen, 4); */
2437 while (len
-- > siglen
) {
2438 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 1);
2439 /* dmemdump(newlen, 1); */
2441 ssh2_pkt_addstring_data(pkt
, (char *)(sigblob
+pos
), siglen
);
2442 /* dmemdump(sigblob+pos, siglen); */
2446 /* Otherwise fall through and do it the easy way. */
2449 ssh2_pkt_addstring_start(pkt
);
2450 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, sigblob_len
);
2454 * Examine the remote side's version string and compare it against
2455 * a list of known buggy implementations.
2457 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
2459 char *imp
; /* pointer to implementation part */
2461 imp
+= strcspn(imp
, "-");
2463 imp
+= strcspn(imp
, "-");
2466 ssh
->remote_bugs
= 0;
2469 * General notes on server version strings:
2470 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2471 * here -- in particular, we've heard of one that's perfectly happy
2472 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2473 * so we can't distinguish them.
2475 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == FORCE_ON
||
2476 (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == AUTO
&&
2477 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
2478 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
2479 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25") ||
2480 !strcmp(imp
, "OSU_1.4alpha3") || !strcmp(imp
, "OSU_1.5alpha4")))) {
2482 * These versions don't support SSH1_MSG_IGNORE, so we have
2483 * to use a different defence against password length
2486 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
2487 logevent("We believe remote version has SSH-1 ignore bug");
2490 if (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == FORCE_ON
||
2491 (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == AUTO
&&
2492 (!strcmp(imp
, "Cisco-1.25") || !strcmp(imp
, "OSU_1.4alpha3")))) {
2494 * These versions need a plain password sent; they can't
2495 * handle having a null and a random length of data after
2498 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
2499 logevent("We believe remote version needs a plain SSH-1 password");
2502 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == FORCE_ON
||
2503 (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == AUTO
&&
2504 (!strcmp(imp
, "Cisco-1.25")))) {
2506 * These versions apparently have no clue whatever about
2507 * RSA authentication and will panic and die if they see
2508 * an AUTH_RSA message.
2510 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
2511 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2514 if (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == FORCE_ON
||
2515 (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == AUTO
&&
2516 !wc_match("* VShell", imp
) &&
2517 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
2518 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
2519 wc_match("2.1 *", imp
)))) {
2521 * These versions have the HMAC bug.
2523 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
2524 logevent("We believe remote version has SSH-2 HMAC bug");
2527 if (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == FORCE_ON
||
2528 (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == AUTO
&&
2529 !wc_match("* VShell", imp
) &&
2530 (wc_match("2.0.0*", imp
) || wc_match("2.0.10*", imp
) ))) {
2532 * These versions have the key-derivation bug (failing to
2533 * include the literal shared secret in the hashes that
2534 * generate the keys).
2536 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
2537 logevent("We believe remote version has SSH-2 key-derivation bug");
2540 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == FORCE_ON
||
2541 (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == AUTO
&&
2542 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
2543 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
2545 * These versions have the SSH-2 RSA padding bug.
2547 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
2548 logevent("We believe remote version has SSH-2 RSA padding bug");
2551 if (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == FORCE_ON
||
2552 (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == AUTO
&&
2553 wc_match("OpenSSH_2.[0-2]*", imp
))) {
2555 * These versions have the SSH-2 session-ID bug in
2556 * public-key authentication.
2558 ssh
->remote_bugs
|= BUG_SSH2_PK_SESSIONID
;
2559 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2562 if (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == FORCE_ON
||
2563 (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == AUTO
&&
2564 (wc_match("DigiSSH_2.0", imp
) ||
2565 wc_match("OpenSSH_2.[0-4]*", imp
) ||
2566 wc_match("OpenSSH_2.5.[0-3]*", imp
) ||
2567 wc_match("Sun_SSH_1.0", imp
) ||
2568 wc_match("Sun_SSH_1.0.1", imp
) ||
2569 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2570 wc_match("WeOnlyDo-*", imp
)))) {
2572 * These versions have the SSH-2 rekey bug.
2574 ssh
->remote_bugs
|= BUG_SSH2_REKEY
;
2575 logevent("We believe remote version has SSH-2 rekey bug");
2578 if (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == FORCE_ON
||
2579 (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == AUTO
&&
2580 (wc_match("1.36_sshlib GlobalSCAPE", imp
) ||
2581 wc_match("1.36 sshlib: GlobalScape", imp
)))) {
2583 * This version ignores our makpkt and needs to be throttled.
2585 ssh
->remote_bugs
|= BUG_SSH2_MAXPKT
;
2586 logevent("We believe remote version ignores SSH-2 maximum packet size");
2589 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore2
) == FORCE_ON
) {
2591 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2592 * none detected automatically.
2594 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH2_IGNORE
;
2595 logevent("We believe remote version has SSH-2 ignore bug");
2598 if (conf_get_int(ssh
->conf
, CONF_sshbug_winadj
) == FORCE_ON
) {
2600 * Servers that don't support our winadj request for one
2601 * reason or another. Currently, none detected automatically.
2603 ssh
->remote_bugs
|= BUG_CHOKES_ON_WINADJ
;
2604 logevent("We believe remote version has winadj bug");
2609 * The `software version' part of an SSH version string is required
2610 * to contain no spaces or minus signs.
2612 static void ssh_fix_verstring(char *str
)
2614 /* Eat "SSH-<protoversion>-". */
2615 assert(*str
== 'S'); str
++;
2616 assert(*str
== 'S'); str
++;
2617 assert(*str
== 'H'); str
++;
2618 assert(*str
== '-'); str
++;
2619 while (*str
&& *str
!= '-') str
++;
2620 assert(*str
== '-'); str
++;
2622 /* Convert minus signs and spaces in the remaining string into
2625 if (*str
== '-' || *str
== ' ')
2632 * Send an appropriate SSH version string.
2634 static void ssh_send_verstring(Ssh ssh
, char *svers
)
2638 if (ssh
->version
== 2) {
2640 * Construct a v2 version string.
2642 verstring
= dupprintf("SSH-2.0-%s\015\012", sshver
);
2645 * Construct a v1 version string.
2647 verstring
= dupprintf("SSH-%s-%s\012",
2648 (ssh_versioncmp(svers
, "1.5") <= 0 ?
2653 ssh_fix_verstring(verstring
);
2655 if (ssh
->version
== 2) {
2658 * Record our version string.
2660 len
= strcspn(verstring
, "\015\012");
2661 ssh
->v_c
= snewn(len
+ 1, char);
2662 memcpy(ssh
->v_c
, verstring
, len
);
2666 logeventf(ssh
, "We claim version: %.*s",
2667 strcspn(verstring
, "\015\012"), verstring
);
2668 s_write(ssh
, verstring
, strlen(verstring
));
2672 static int do_ssh_init(Ssh ssh
, unsigned char c
)
2674 struct do_ssh_init_state
{
2683 crState(do_ssh_init_state
);
2687 /* Search for a line beginning with the string "SSH-" in the input. */
2689 if (c
!= 'S') goto no
;
2691 if (c
!= 'S') goto no
;
2693 if (c
!= 'H') goto no
;
2695 if (c
!= '-') goto no
;
2704 s
->vstring
= snewn(s
->vstrsize
, char);
2705 strcpy(s
->vstring
, "SSH-");
2709 crReturn(1); /* get another char */
2710 if (s
->vslen
>= s
->vstrsize
- 1) {
2712 s
->vstring
= sresize(s
->vstring
, s
->vstrsize
, char);
2714 s
->vstring
[s
->vslen
++] = c
;
2717 s
->version
[s
->i
] = '\0';
2719 } else if (s
->i
< sizeof(s
->version
) - 1)
2720 s
->version
[s
->i
++] = c
;
2721 } else if (c
== '\012')
2725 ssh
->agentfwd_enabled
= FALSE
;
2726 ssh
->rdpkt2_state
.incoming_sequence
= 0;
2728 s
->vstring
[s
->vslen
] = 0;
2729 s
->vstring
[strcspn(s
->vstring
, "\015\012")] = '\0';/* remove EOL chars */
2730 logeventf(ssh
, "Server version: %s", s
->vstring
);
2731 ssh_detect_bugs(ssh
, s
->vstring
);
2734 * Decide which SSH protocol version to support.
2737 /* Anything strictly below "2.0" means protocol 1 is supported. */
2738 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
2739 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2740 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
2742 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 0 && !s
->proto1
) {
2743 bombout(("SSH protocol version 1 required by user but not provided by server"));
2746 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 3 && !s
->proto2
) {
2747 bombout(("SSH protocol version 2 required by user but not provided by server"));
2751 if (s
->proto2
&& (conf_get_int(ssh
->conf
, CONF_sshprot
) >= 2 || !s
->proto1
))
2756 logeventf(ssh
, "Using SSH protocol version %d", ssh
->version
);
2758 /* Send the version string, if we haven't already */
2759 if (conf_get_int(ssh
->conf
, CONF_sshprot
) != 3)
2760 ssh_send_verstring(ssh
, s
->version
);
2762 if (ssh
->version
== 2) {
2765 * Record their version string.
2767 len
= strcspn(s
->vstring
, "\015\012");
2768 ssh
->v_s
= snewn(len
+ 1, char);
2769 memcpy(ssh
->v_s
, s
->vstring
, len
);
2773 * Initialise SSH-2 protocol.
2775 ssh
->protocol
= ssh2_protocol
;
2776 ssh2_protocol_setup(ssh
);
2777 ssh
->s_rdpkt
= ssh2_rdpkt
;
2780 * Initialise SSH-1 protocol.
2782 ssh
->protocol
= ssh1_protocol
;
2783 ssh1_protocol_setup(ssh
);
2784 ssh
->s_rdpkt
= ssh1_rdpkt
;
2786 if (ssh
->version
== 2)
2787 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
2789 update_specials_menu(ssh
->frontend
);
2790 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
2791 ssh
->pinger
= pinger_new(ssh
->conf
, &ssh_backend
, ssh
);
2798 static void ssh_process_incoming_data(Ssh ssh
,
2799 unsigned char **data
, int *datalen
)
2801 struct Packet
*pktin
;
2803 pktin
= ssh
->s_rdpkt(ssh
, data
, datalen
);
2805 ssh
->protocol(ssh
, NULL
, 0, pktin
);
2806 ssh_free_packet(pktin
);
2810 static void ssh_queue_incoming_data(Ssh ssh
,
2811 unsigned char **data
, int *datalen
)
2813 bufchain_add(&ssh
->queued_incoming_data
, *data
, *datalen
);
2818 static void ssh_process_queued_incoming_data(Ssh ssh
)
2821 unsigned char *data
;
2824 while (!ssh
->frozen
&& bufchain_size(&ssh
->queued_incoming_data
)) {
2825 bufchain_prefix(&ssh
->queued_incoming_data
, &vdata
, &len
);
2829 while (!ssh
->frozen
&& len
> 0)
2830 ssh_process_incoming_data(ssh
, &data
, &len
);
2833 bufchain_consume(&ssh
->queued_incoming_data
, origlen
- len
);
2837 static void ssh_set_frozen(Ssh ssh
, int frozen
)
2840 sk_set_frozen(ssh
->s
, frozen
);
2841 ssh
->frozen
= frozen
;
2844 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
2846 /* Log raw data, if we're in that mode. */
2848 log_packet(ssh
->logctx
, PKT_INCOMING
, -1, NULL
, data
, datalen
,
2851 crBegin(ssh
->ssh_gotdata_crstate
);
2854 * To begin with, feed the characters one by one to the
2855 * protocol initialisation / selection function do_ssh_init().
2856 * When that returns 0, we're done with the initial greeting
2857 * exchange and can move on to packet discipline.
2860 int ret
; /* need not be kept across crReturn */
2862 crReturnV
; /* more data please */
2863 ret
= do_ssh_init(ssh
, *data
);
2871 * We emerge from that loop when the initial negotiation is
2872 * over and we have selected an s_rdpkt function. Now pass
2873 * everything to s_rdpkt, and then pass the resulting packets
2874 * to the proper protocol handler.
2878 while (bufchain_size(&ssh
->queued_incoming_data
) > 0 || datalen
> 0) {
2880 ssh_queue_incoming_data(ssh
, &data
, &datalen
);
2881 /* This uses up all data and cannot cause anything interesting
2882 * to happen; indeed, for anything to happen at all, we must
2883 * return, so break out. */
2885 } else if (bufchain_size(&ssh
->queued_incoming_data
) > 0) {
2886 /* This uses up some or all data, and may freeze the
2888 ssh_process_queued_incoming_data(ssh
);
2890 /* This uses up some or all data, and may freeze the
2892 ssh_process_incoming_data(ssh
, &data
, &datalen
);
2894 /* FIXME this is probably EBW. */
2895 if (ssh
->state
== SSH_STATE_CLOSED
)
2898 /* We're out of data. Go and get some more. */
2904 static int ssh_do_close(Ssh ssh
, int notify_exit
)
2907 struct ssh_channel
*c
;
2909 ssh
->state
= SSH_STATE_CLOSED
;
2910 expire_timer_context(ssh
);
2915 notify_remote_exit(ssh
->frontend
);
2920 * Now we must shut down any port- and X-forwarded channels going
2921 * through this connection.
2923 if (ssh
->channels
) {
2924 while (NULL
!= (c
= index234(ssh
->channels
, 0))) {
2927 x11_close(c
->u
.x11
.s
);
2930 case CHAN_SOCKDATA_DORMANT
:
2931 pfd_close(c
->u
.pfd
.s
);
2934 del234(ssh
->channels
, c
); /* moving next one to index 0 */
2935 if (ssh
->version
== 2)
2936 bufchain_clear(&c
->v
.v2
.outbuffer
);
2941 * Go through port-forwardings, and close any associated
2942 * listening sockets.
2944 if (ssh
->portfwds
) {
2945 struct ssh_portfwd
*pf
;
2946 while (NULL
!= (pf
= index234(ssh
->portfwds
, 0))) {
2947 /* Dispose of any listening socket. */
2949 pfd_terminate(pf
->local
);
2950 del234(ssh
->portfwds
, pf
); /* moving next one to index 0 */
2953 freetree234(ssh
->portfwds
);
2954 ssh
->portfwds
= NULL
;
2960 static void ssh_log(Plug plug
, int type
, SockAddr addr
, int port
,
2961 const char *error_msg
, int error_code
)
2963 Ssh ssh
= (Ssh
) plug
;
2964 char addrbuf
[256], *msg
;
2966 sk_getaddr(addr
, addrbuf
, lenof(addrbuf
));
2969 msg
= dupprintf("Connecting to %s port %d", addrbuf
, port
);
2971 msg
= dupprintf("Failed to connect to %s: %s", addrbuf
, error_msg
);
2977 static int ssh_closing(Plug plug
, const char *error_msg
, int error_code
,
2980 Ssh ssh
= (Ssh
) plug
;
2981 int need_notify
= ssh_do_close(ssh
, FALSE
);
2984 if (!ssh
->close_expected
)
2985 error_msg
= "Server unexpectedly closed network connection";
2987 error_msg
= "Server closed network connection";
2990 if (ssh
->close_expected
&& ssh
->clean_exit
&& ssh
->exitcode
< 0)
2994 notify_remote_exit(ssh
->frontend
);
2997 logevent(error_msg
);
2998 if (!ssh
->close_expected
|| !ssh
->clean_exit
)
2999 connection_fatal(ssh
->frontend
, "%s", error_msg
);
3003 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
3005 Ssh ssh
= (Ssh
) plug
;
3006 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
3007 if (ssh
->state
== SSH_STATE_CLOSED
) {
3008 ssh_do_close(ssh
, TRUE
);
3014 static void ssh_sent(Plug plug
, int bufsize
)
3016 Ssh ssh
= (Ssh
) plug
;
3018 * If the send backlog on the SSH socket itself clears, we
3019 * should unthrottle the whole world if it was throttled.
3021 if (bufsize
< SSH_MAX_BACKLOG
)
3022 ssh_throttle_all(ssh
, 0, bufsize
);
3026 * Connect to specified host and port.
3027 * Returns an error message, or NULL on success.
3028 * Also places the canonical host name into `realhost'. It must be
3029 * freed by the caller.
3031 static const char *connect_to_host(Ssh ssh
, char *host
, int port
,
3032 char **realhost
, int nodelay
, int keepalive
)
3034 static const struct plug_function_table fn_table
= {
3045 int addressfamily
, sshprot
;
3047 loghost
= conf_get_str(ssh
->conf
, CONF_loghost
);
3051 ssh
->savedhost
= dupstr(loghost
);
3052 ssh
->savedport
= 22; /* default ssh port */
3055 * A colon suffix on savedhost also lets us affect
3058 * (FIXME: do something about IPv6 address literals here.)
3060 colon
= strrchr(ssh
->savedhost
, ':');
3064 ssh
->savedport
= atoi(colon
);
3067 ssh
->savedhost
= dupstr(host
);
3069 port
= 22; /* default ssh port */
3070 ssh
->savedport
= port
;
3076 addressfamily
= conf_get_int(ssh
->conf
, CONF_addressfamily
);
3077 logeventf(ssh
, "Looking up host \"%s\"%s", host
,
3078 (addressfamily
== ADDRTYPE_IPV4 ?
" (IPv4)" :
3079 (addressfamily
== ADDRTYPE_IPV6 ?
" (IPv6)" : "")));
3080 addr
= name_lookup(host
, port
, realhost
, ssh
->conf
, addressfamily
);
3081 if ((err
= sk_addr_error(addr
)) != NULL
) {
3085 ssh
->fullhostname
= dupstr(*realhost
); /* save in case of GSSAPI */
3090 ssh
->fn
= &fn_table
;
3091 ssh
->s
= new_connection(addr
, *realhost
, port
,
3092 0, 1, nodelay
, keepalive
, (Plug
) ssh
, ssh
->conf
);
3093 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
3095 notify_remote_exit(ssh
->frontend
);
3100 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3101 * send the version string too.
3103 sshprot
= conf_get_int(ssh
->conf
, CONF_sshprot
);
3108 ssh_send_verstring(ssh
, NULL
);
3112 * loghost, if configured, overrides realhost.
3116 *realhost
= dupstr(loghost
);
3123 * Throttle or unthrottle the SSH connection.
3125 static void ssh_throttle_conn(Ssh ssh
, int adjust
)
3127 int old_count
= ssh
->conn_throttle_count
;
3128 ssh
->conn_throttle_count
+= adjust
;
3129 assert(ssh
->conn_throttle_count
>= 0);
3130 if (ssh
->conn_throttle_count
&& !old_count
) {
3131 ssh_set_frozen(ssh
, 1);
3132 } else if (!ssh
->conn_throttle_count
&& old_count
) {
3133 ssh_set_frozen(ssh
, 0);
3138 * Throttle or unthrottle _all_ local data streams (for when sends
3139 * on the SSH connection itself back up).
3141 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
3144 struct ssh_channel
*c
;
3146 if (enable
== ssh
->throttled_all
)
3148 ssh
->throttled_all
= enable
;
3149 ssh
->overall_bufsize
= bufsize
;
3152 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
3154 case CHAN_MAINSESSION
:
3156 * This is treated separately, outside the switch.
3160 x11_override_throttle(c
->u
.x11
.s
, enable
);
3163 /* Agent channels require no buffer management. */
3166 pfd_override_throttle(c
->u
.pfd
.s
, enable
);
3172 static void ssh_agent_callback(void *sshv
, void *reply
, int replylen
)
3174 Ssh ssh
= (Ssh
) sshv
;
3176 ssh
->agent_response
= reply
;
3177 ssh
->agent_response_len
= replylen
;
3179 if (ssh
->version
== 1)
3180 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3182 do_ssh2_authconn(ssh
, NULL
, -1, NULL
);
3185 static void ssh_dialog_callback(void *sshv
, int ret
)
3187 Ssh ssh
= (Ssh
) sshv
;
3189 ssh
->user_response
= ret
;
3191 if (ssh
->version
== 1)
3192 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3194 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
3197 * This may have unfrozen the SSH connection, so do a
3200 ssh_process_queued_incoming_data(ssh
);
3203 static void ssh_agentf_callback(void *cv
, void *reply
, int replylen
)
3205 struct ssh_channel
*c
= (struct ssh_channel
*)cv
;
3207 void *sentreply
= reply
;
3210 /* Fake SSH_AGENT_FAILURE. */
3211 sentreply
= "\0\0\0\1\5";
3214 if (ssh
->version
== 2) {
3215 ssh2_add_channel_data(c
, sentreply
, replylen
);
3218 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3219 PKT_INT
, c
->remoteid
,
3222 PKT_DATA
, sentreply
, replylen
,
3231 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3232 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3233 * => log `wire_reason'.
3235 static void ssh_disconnect(Ssh ssh
, char *client_reason
, char *wire_reason
,
3236 int code
, int clean_exit
)
3240 client_reason
= wire_reason
;
3242 error
= dupprintf("Disconnected: %s", client_reason
);
3244 error
= dupstr("Disconnected");
3246 if (ssh
->version
== 1) {
3247 send_packet(ssh
, SSH1_MSG_DISCONNECT
, PKT_STR
, wire_reason
,
3249 } else if (ssh
->version
== 2) {
3250 struct Packet
*pktout
= ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3251 ssh2_pkt_adduint32(pktout
, code
);
3252 ssh2_pkt_addstring(pktout
, wire_reason
);
3253 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
3254 ssh2_pkt_send_noqueue(ssh
, pktout
);
3257 ssh
->close_expected
= TRUE
;
3258 ssh
->clean_exit
= clean_exit
;
3259 ssh_closing((Plug
)ssh
, error
, 0, 0);
3264 * Handle the key exchange and user authentication phases.
3266 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
,
3267 struct Packet
*pktin
)
3270 unsigned char cookie
[8], *ptr
;
3271 struct RSAKey servkey
, hostkey
;
3272 struct MD5Context md5c
;
3273 struct do_ssh1_login_state
{
3276 unsigned char *rsabuf
, *keystr1
, *keystr2
;
3277 unsigned long supported_ciphers_mask
, supported_auths_mask
;
3278 int tried_publickey
, tried_agent
;
3279 int tis_auth_refused
, ccard_auth_refused
;
3280 unsigned char session_id
[16];
3282 void *publickey_blob
;
3283 int publickey_bloblen
;
3284 char *publickey_comment
;
3285 int publickey_encrypted
;
3286 prompts_t
*cur_prompt
;
3289 unsigned char request
[5], *response
, *p
;
3300 crState(do_ssh1_login_state
);
3307 if (pktin
->type
!= SSH1_SMSG_PUBLIC_KEY
) {
3308 bombout(("Public key packet not received"));
3312 logevent("Received public keys");
3314 ptr
= ssh_pkt_getdata(pktin
, 8);
3316 bombout(("SSH-1 public key packet stopped before random cookie"));
3319 memcpy(cookie
, ptr
, 8);
3321 if (!ssh1_pkt_getrsakey(pktin
, &servkey
, &s
->keystr1
) ||
3322 !ssh1_pkt_getrsakey(pktin
, &hostkey
, &s
->keystr2
)) {
3323 bombout(("Failed to read SSH-1 public keys from public key packet"));
3328 * Log the host key fingerprint.
3332 logevent("Host key fingerprint is:");
3333 strcpy(logmsg
, " ");
3334 hostkey
.comment
= NULL
;
3335 rsa_fingerprint(logmsg
+ strlen(logmsg
),
3336 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
3340 ssh
->v1_remote_protoflags
= ssh_pkt_getuint32(pktin
);
3341 s
->supported_ciphers_mask
= ssh_pkt_getuint32(pktin
);
3342 s
->supported_auths_mask
= ssh_pkt_getuint32(pktin
);
3343 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
))
3344 s
->supported_auths_mask
&= ~(1 << SSH1_AUTH_RSA
);
3346 ssh
->v1_local_protoflags
=
3347 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
3348 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
3351 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
3352 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
3353 MD5Update(&md5c
, cookie
, 8);
3354 MD5Final(s
->session_id
, &md5c
);
3356 for (i
= 0; i
< 32; i
++)
3357 ssh
->session_key
[i
] = random_byte();
3360 * Verify that the `bits' and `bytes' parameters match.
3362 if (hostkey
.bits
> hostkey
.bytes
* 8 ||
3363 servkey
.bits
> servkey
.bytes
* 8) {
3364 bombout(("SSH-1 public keys were badly formatted"));
3368 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
3370 s
->rsabuf
= snewn(s
->len
, unsigned char);
3373 * Verify the host key.
3377 * First format the key into a string.
3379 int len
= rsastr_len(&hostkey
);
3380 char fingerprint
[100];
3381 char *keystr
= snewn(len
, char);
3382 rsastr_fmt(keystr
, &hostkey
);
3383 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
3385 ssh_set_frozen(ssh
, 1);
3386 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
3387 ssh
->savedhost
, ssh
->savedport
,
3388 "rsa", keystr
, fingerprint
,
3389 ssh_dialog_callback
, ssh
);
3391 if (s
->dlgret
< 0) {
3395 bombout(("Unexpected data from server while waiting"
3396 " for user host key response"));
3399 } while (pktin
|| inlen
> 0);
3400 s
->dlgret
= ssh
->user_response
;
3402 ssh_set_frozen(ssh
, 0);
3404 if (s
->dlgret
== 0) {
3405 ssh_disconnect(ssh
, "User aborted at host key verification",
3411 for (i
= 0; i
< 32; i
++) {
3412 s
->rsabuf
[i
] = ssh
->session_key
[i
];
3414 s
->rsabuf
[i
] ^= s
->session_id
[i
];
3417 if (hostkey
.bytes
> servkey
.bytes
) {
3418 ret
= rsaencrypt(s
->rsabuf
, 32, &servkey
);
3420 ret
= rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
3422 ret
= rsaencrypt(s
->rsabuf
, 32, &hostkey
);
3424 ret
= rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
3427 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3431 logevent("Encrypted session key");
3434 int cipher_chosen
= 0, warn
= 0;
3435 char *cipher_string
= NULL
;
3437 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
3438 int next_cipher
= conf_get_int_int(ssh
->conf
,
3439 CONF_ssh_cipherlist
, i
);
3440 if (next_cipher
== CIPHER_WARN
) {
3441 /* If/when we choose a cipher, warn about it */
3443 } else if (next_cipher
== CIPHER_AES
) {
3444 /* XXX Probably don't need to mention this. */
3445 logevent("AES not supported in SSH-1, skipping");
3447 switch (next_cipher
) {
3448 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
3449 cipher_string
= "3DES"; break;
3450 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
3451 cipher_string
= "Blowfish"; break;
3452 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
3453 cipher_string
= "single-DES"; break;
3455 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
3459 if (!cipher_chosen
) {
3460 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
3461 bombout(("Server violates SSH-1 protocol by not "
3462 "supporting 3DES encryption"));
3464 /* shouldn't happen */
3465 bombout(("No supported ciphers found"));
3469 /* Warn about chosen cipher if necessary. */
3471 ssh_set_frozen(ssh
, 1);
3472 s
->dlgret
= askalg(ssh
->frontend
, "cipher", cipher_string
,
3473 ssh_dialog_callback
, ssh
);
3474 if (s
->dlgret
< 0) {
3478 bombout(("Unexpected data from server while waiting"
3479 " for user response"));
3482 } while (pktin
|| inlen
> 0);
3483 s
->dlgret
= ssh
->user_response
;
3485 ssh_set_frozen(ssh
, 0);
3486 if (s
->dlgret
== 0) {
3487 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
3494 switch (s
->cipher_type
) {
3495 case SSH_CIPHER_3DES
:
3496 logevent("Using 3DES encryption");
3498 case SSH_CIPHER_DES
:
3499 logevent("Using single-DES encryption");
3501 case SSH_CIPHER_BLOWFISH
:
3502 logevent("Using Blowfish encryption");
3506 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
3507 PKT_CHAR
, s
->cipher_type
,
3508 PKT_DATA
, cookie
, 8,
3509 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
3510 PKT_DATA
, s
->rsabuf
, s
->len
,
3511 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
3513 logevent("Trying to enable encryption...");
3517 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
3518 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
3520 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
3521 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
3522 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
3524 ssh
->crcda_ctx
= crcda_make_context();
3525 logevent("Installing CRC compensation attack detector");
3527 if (servkey
.modulus
) {
3528 sfree(servkey
.modulus
);
3529 servkey
.modulus
= NULL
;
3531 if (servkey
.exponent
) {
3532 sfree(servkey
.exponent
);
3533 servkey
.exponent
= NULL
;
3535 if (hostkey
.modulus
) {
3536 sfree(hostkey
.modulus
);
3537 hostkey
.modulus
= NULL
;
3539 if (hostkey
.exponent
) {
3540 sfree(hostkey
.exponent
);
3541 hostkey
.exponent
= NULL
;
3545 if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3546 bombout(("Encryption not successfully enabled"));
3550 logevent("Successfully started encryption");
3552 fflush(stdout
); /* FIXME eh? */
3554 if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
3555 int ret
; /* need not be kept over crReturn */
3556 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3557 s
->cur_prompt
->to_server
= TRUE
;
3558 s
->cur_prompt
->name
= dupstr("SSH login name");
3559 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
3560 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3563 crWaitUntil(!pktin
);
3564 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3569 * Failed to get a username. Terminate.
3571 free_prompts(s
->cur_prompt
);
3572 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
3575 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3576 free_prompts(s
->cur_prompt
);
3579 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, ssh
->username
, PKT_END
);
3581 char *userlog
= dupprintf("Sent username \"%s\"", ssh
->username
);
3583 if (flags
& FLAG_INTERACTIVE
&&
3584 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
3585 c_write_str(ssh
, userlog
);
3586 c_write_str(ssh
, "\r\n");
3594 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_RSA
)) == 0) {
3595 /* We must not attempt PK auth. Pretend we've already tried it. */
3596 s
->tried_publickey
= s
->tried_agent
= 1;
3598 s
->tried_publickey
= s
->tried_agent
= 0;
3600 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
3602 * Load the public half of any configured keyfile for later use.
3604 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3605 if (!filename_is_null(s
->keyfile
)) {
3607 logeventf(ssh
, "Reading private key file \"%.150s\"",
3608 filename_to_str(s
->keyfile
));
3609 keytype
= key_type(s
->keyfile
);
3610 if (keytype
== SSH_KEYTYPE_SSH1
) {
3612 if (rsakey_pubblob(s
->keyfile
,
3613 &s
->publickey_blob
, &s
->publickey_bloblen
,
3614 &s
->publickey_comment
, &error
)) {
3615 s
->publickey_encrypted
= rsakey_encrypted(s
->keyfile
,
3619 logeventf(ssh
, "Unable to load private key (%s)", error
);
3620 msgbuf
= dupprintf("Unable to load private key file "
3621 "\"%.150s\" (%s)\r\n",
3622 filename_to_str(s
->keyfile
),
3624 c_write_str(ssh
, msgbuf
);
3626 s
->publickey_blob
= NULL
;
3630 logeventf(ssh
, "Unable to use this key file (%s)",
3631 key_type_to_str(keytype
));
3632 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
3634 filename_to_str(s
->keyfile
),
3635 key_type_to_str(keytype
));
3636 c_write_str(ssh
, msgbuf
);
3638 s
->publickey_blob
= NULL
;
3641 s
->publickey_blob
= NULL
;
3643 while (pktin
->type
== SSH1_SMSG_FAILURE
) {
3644 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
3646 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists() && !s
->tried_agent
) {
3648 * Attempt RSA authentication using Pageant.
3654 logevent("Pageant is running. Requesting keys.");
3656 /* Request the keys held by the agent. */
3657 PUT_32BIT(s
->request
, 1);
3658 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
3659 if (!agent_query(s
->request
, 5, &r
, &s
->responselen
,
3660 ssh_agent_callback
, ssh
)) {
3664 bombout(("Unexpected data from server while waiting"
3665 " for agent response"));
3668 } while (pktin
|| inlen
> 0);
3669 r
= ssh
->agent_response
;
3670 s
->responselen
= ssh
->agent_response_len
;
3672 s
->response
= (unsigned char *) r
;
3673 if (s
->response
&& s
->responselen
>= 5 &&
3674 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
3675 s
->p
= s
->response
+ 5;
3676 s
->nkeys
= GET_32BIT(s
->p
);
3678 logeventf(ssh
, "Pageant has %d SSH-1 keys", s
->nkeys
);
3679 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
3680 unsigned char *pkblob
= s
->p
;
3684 do { /* do while (0) to make breaking easy */
3685 n
= ssh1_read_bignum
3686 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3691 n
= ssh1_read_bignum
3692 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3697 if (s
->responselen
- (s
->p
-s
->response
) < 4)
3699 s
->commentlen
= GET_32BIT(s
->p
);
3701 if (s
->responselen
- (s
->p
-s
->response
) <
3704 s
->commentp
= (char *)s
->p
;
3705 s
->p
+= s
->commentlen
;
3709 logevent("Pageant key list packet was truncated");
3713 if (s
->publickey_blob
) {
3714 if (!memcmp(pkblob
, s
->publickey_blob
,
3715 s
->publickey_bloblen
)) {
3716 logeventf(ssh
, "Pageant key #%d matches "
3717 "configured key file", s
->keyi
);
3718 s
->tried_publickey
= 1;
3720 /* Skip non-configured key */
3723 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
3724 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3725 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3727 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3728 logevent("Key refused");
3731 logevent("Received RSA challenge");
3732 if ((s
->challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3733 bombout(("Server's RSA challenge was badly formatted"));
3738 char *agentreq
, *q
, *ret
;
3741 len
= 1 + 4; /* message type, bit count */
3742 len
+= ssh1_bignum_length(s
->key
.exponent
);
3743 len
+= ssh1_bignum_length(s
->key
.modulus
);
3744 len
+= ssh1_bignum_length(s
->challenge
);
3745 len
+= 16; /* session id */
3746 len
+= 4; /* response format */
3747 agentreq
= snewn(4 + len
, char);
3748 PUT_32BIT(agentreq
, len
);
3750 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
3751 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
3753 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
3754 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
3755 q
+= ssh1_write_bignum(q
, s
->challenge
);
3756 memcpy(q
, s
->session_id
, 16);
3758 PUT_32BIT(q
, 1); /* response format */
3759 if (!agent_query(agentreq
, len
+ 4, &vret
, &retlen
,
3760 ssh_agent_callback
, ssh
)) {
3765 bombout(("Unexpected data from server"
3766 " while waiting for agent"
3770 } while (pktin
|| inlen
> 0);
3771 vret
= ssh
->agent_response
;
3772 retlen
= ssh
->agent_response_len
;
3777 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
3778 logevent("Sending Pageant's response");
3779 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3780 PKT_DATA
, ret
+ 5, 16,
3784 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
3786 ("Pageant's response accepted");
3787 if (flags
& FLAG_VERBOSE
) {
3788 c_write_str(ssh
, "Authenticated using"
3790 c_write(ssh
, s
->commentp
,
3792 c_write_str(ssh
, "\" from agent\r\n");
3797 ("Pageant's response not accepted");
3800 ("Pageant failed to answer challenge");
3804 logevent("No reply received from Pageant");
3807 freebn(s
->key
.exponent
);
3808 freebn(s
->key
.modulus
);
3809 freebn(s
->challenge
);
3814 if (s
->publickey_blob
&& !s
->tried_publickey
)
3815 logevent("Configured key file not in Pageant");
3817 logevent("Failed to get reply from Pageant");
3822 if (s
->publickey_blob
&& !s
->tried_publickey
) {
3824 * Try public key authentication with the specified
3827 int got_passphrase
; /* need not be kept over crReturn */
3828 if (flags
& FLAG_VERBOSE
)
3829 c_write_str(ssh
, "Trying public key authentication.\r\n");
3830 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3831 logeventf(ssh
, "Trying public key \"%s\"",
3832 filename_to_str(s
->keyfile
));
3833 s
->tried_publickey
= 1;
3834 got_passphrase
= FALSE
;
3835 while (!got_passphrase
) {
3837 * Get a passphrase, if necessary.
3839 char *passphrase
= NULL
; /* only written after crReturn */
3841 if (!s
->publickey_encrypted
) {
3842 if (flags
& FLAG_VERBOSE
)
3843 c_write_str(ssh
, "No passphrase required.\r\n");
3846 int ret
; /* need not be kept over crReturn */
3847 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3848 s
->cur_prompt
->to_server
= FALSE
;
3849 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
3850 add_prompt(s
->cur_prompt
,
3851 dupprintf("Passphrase for key \"%.100s\": ",
3852 s
->publickey_comment
), FALSE
);
3853 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3856 crWaitUntil(!pktin
);
3857 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3861 /* Failed to get a passphrase. Terminate. */
3862 free_prompts(s
->cur_prompt
);
3863 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
3867 passphrase
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3868 free_prompts(s
->cur_prompt
);
3871 * Try decrypting key with passphrase.
3873 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3874 ret
= loadrsakey(s
->keyfile
, &s
->key
, passphrase
,
3877 smemclr(passphrase
, strlen(passphrase
));
3881 /* Correct passphrase. */
3882 got_passphrase
= TRUE
;
3883 } else if (ret
== 0) {
3884 c_write_str(ssh
, "Couldn't load private key from ");
3885 c_write_str(ssh
, filename_to_str(s
->keyfile
));
3886 c_write_str(ssh
, " (");
3887 c_write_str(ssh
, error
);
3888 c_write_str(ssh
, ").\r\n");
3889 got_passphrase
= FALSE
;
3890 break; /* go and try something else */
3891 } else if (ret
== -1) {
3892 c_write_str(ssh
, "Wrong passphrase.\r\n"); /* FIXME */
3893 got_passphrase
= FALSE
;
3896 assert(0 && "unexpected return from loadrsakey()");
3897 got_passphrase
= FALSE
; /* placate optimisers */
3901 if (got_passphrase
) {
3904 * Send a public key attempt.
3906 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3907 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3910 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3911 c_write_str(ssh
, "Server refused our public key.\r\n");
3912 continue; /* go and try something else */
3914 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3915 bombout(("Bizarre response to offer of public key"));
3921 unsigned char buffer
[32];
3922 Bignum challenge
, response
;
3924 if ((challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3925 bombout(("Server's RSA challenge was badly formatted"));
3928 response
= rsadecrypt(challenge
, &s
->key
);
3929 freebn(s
->key
.private_exponent
);/* burn the evidence */
3931 for (i
= 0; i
< 32; i
++) {
3932 buffer
[i
] = bignum_byte(response
, 31 - i
);
3936 MD5Update(&md5c
, buffer
, 32);
3937 MD5Update(&md5c
, s
->session_id
, 16);
3938 MD5Final(buffer
, &md5c
);
3940 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3941 PKT_DATA
, buffer
, 16, PKT_END
);
3948 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3949 if (flags
& FLAG_VERBOSE
)
3950 c_write_str(ssh
, "Failed to authenticate with"
3951 " our public key.\r\n");
3952 continue; /* go and try something else */
3953 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3954 bombout(("Bizarre response to RSA authentication response"));
3958 break; /* we're through! */
3964 * Otherwise, try various forms of password-like authentication.
3966 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3968 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
3969 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
3970 !s
->tis_auth_refused
) {
3971 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
3972 logevent("Requested TIS authentication");
3973 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
3975 if (pktin
->type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
3976 logevent("TIS authentication declined");
3977 if (flags
& FLAG_INTERACTIVE
)
3978 c_write_str(ssh
, "TIS authentication refused.\r\n");
3979 s
->tis_auth_refused
= 1;
3984 char *instr_suf
, *prompt
;
3986 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
3988 bombout(("TIS challenge packet was badly formed"));
3991 logevent("Received TIS challenge");
3992 s
->cur_prompt
->to_server
= TRUE
;
3993 s
->cur_prompt
->name
= dupstr("SSH TIS authentication");
3994 /* Prompt heuristic comes from OpenSSH */
3995 if (memchr(challenge
, '\n', challengelen
)) {
3996 instr_suf
= dupstr("");
3997 prompt
= dupprintf("%.*s", challengelen
, challenge
);
3999 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
4000 prompt
= dupstr("Response: ");
4002 s
->cur_prompt
->instruction
=
4003 dupprintf("Using TIS authentication.%s%s",
4004 (*instr_suf
) ?
"\n" : "",
4006 s
->cur_prompt
->instr_reqd
= TRUE
;
4007 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
4011 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
4012 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
4013 !s
->ccard_auth_refused
) {
4014 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
4015 logevent("Requested CryptoCard authentication");
4016 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
4018 if (pktin
->type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
4019 logevent("CryptoCard authentication declined");
4020 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
4021 s
->ccard_auth_refused
= 1;
4026 char *instr_suf
, *prompt
;
4028 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
4030 bombout(("CryptoCard challenge packet was badly formed"));
4033 logevent("Received CryptoCard challenge");
4034 s
->cur_prompt
->to_server
= TRUE
;
4035 s
->cur_prompt
->name
= dupstr("SSH CryptoCard authentication");
4036 s
->cur_prompt
->name_reqd
= FALSE
;
4037 /* Prompt heuristic comes from OpenSSH */
4038 if (memchr(challenge
, '\n', challengelen
)) {
4039 instr_suf
= dupstr("");
4040 prompt
= dupprintf("%.*s", challengelen
, challenge
);
4042 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
4043 prompt
= dupstr("Response: ");
4045 s
->cur_prompt
->instruction
=
4046 dupprintf("Using CryptoCard authentication.%s%s",
4047 (*instr_suf
) ?
"\n" : "",
4049 s
->cur_prompt
->instr_reqd
= TRUE
;
4050 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
4054 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4055 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_PASSWORD
)) == 0) {
4056 bombout(("No supported authentication methods available"));
4059 s
->cur_prompt
->to_server
= TRUE
;
4060 s
->cur_prompt
->name
= dupstr("SSH password");
4061 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
4062 ssh
->username
, ssh
->savedhost
),
4067 * Show password prompt, having first obtained it via a TIS
4068 * or CryptoCard exchange if we're doing TIS or CryptoCard
4072 int ret
; /* need not be kept over crReturn */
4073 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
4076 crWaitUntil(!pktin
);
4077 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
4082 * Failed to get a password (for example
4083 * because one was supplied on the command line
4084 * which has already failed to work). Terminate.
4086 free_prompts(s
->cur_prompt
);
4087 ssh_disconnect(ssh
, NULL
, "Unable to authenticate", 0, TRUE
);
4092 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4094 * Defence against traffic analysis: we send a
4095 * whole bunch of packets containing strings of
4096 * different lengths. One of these strings is the
4097 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4098 * The others are all random data in
4099 * SSH1_MSG_IGNORE packets. This way a passive
4100 * listener can't tell which is the password, and
4101 * hence can't deduce the password length.
4103 * Anybody with a password length greater than 16
4104 * bytes is going to have enough entropy in their
4105 * password that a listener won't find it _that_
4106 * much help to know how long it is. So what we'll
4109 * - if password length < 16, we send 15 packets
4110 * containing string lengths 1 through 15
4112 * - otherwise, we let N be the nearest multiple
4113 * of 8 below the password length, and send 8
4114 * packets containing string lengths N through
4115 * N+7. This won't obscure the order of
4116 * magnitude of the password length, but it will
4117 * introduce a bit of extra uncertainty.
4119 * A few servers can't deal with SSH1_MSG_IGNORE, at
4120 * least in this context. For these servers, we need
4121 * an alternative defence. We make use of the fact
4122 * that the password is interpreted as a C string:
4123 * so we can append a NUL, then some random data.
4125 * A few servers can deal with neither SSH1_MSG_IGNORE
4126 * here _nor_ a padded password string.
4127 * For these servers we are left with no defences
4128 * against password length sniffing.
4130 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) &&
4131 !(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4133 * The server can deal with SSH1_MSG_IGNORE, so
4134 * we can use the primary defence.
4136 int bottom
, top
, pwlen
, i
;
4139 pwlen
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4141 bottom
= 0; /* zero length passwords are OK! :-) */
4144 bottom
= pwlen
& ~7;
4148 assert(pwlen
>= bottom
&& pwlen
<= top
);
4150 randomstr
= snewn(top
+ 1, char);
4152 for (i
= bottom
; i
<= top
; i
++) {
4154 defer_packet(ssh
, s
->pwpkt_type
,
4155 PKTT_PASSWORD
, PKT_STR
,
4156 s
->cur_prompt
->prompts
[0]->result
,
4157 PKTT_OTHER
, PKT_END
);
4159 for (j
= 0; j
< i
; j
++) {
4161 randomstr
[j
] = random_byte();
4162 } while (randomstr
[j
] == '\0');
4164 randomstr
[i
] = '\0';
4165 defer_packet(ssh
, SSH1_MSG_IGNORE
,
4166 PKT_STR
, randomstr
, PKT_END
);
4169 logevent("Sending password with camouflage packets");
4170 ssh_pkt_defersend(ssh
);
4173 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4175 * The server can't deal with SSH1_MSG_IGNORE
4176 * but can deal with padded passwords, so we
4177 * can use the secondary defence.
4183 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4184 if (len
< sizeof(string
)) {
4186 strcpy(string
, s
->cur_prompt
->prompts
[0]->result
);
4187 len
++; /* cover the zero byte */
4188 while (len
< sizeof(string
)) {
4189 string
[len
++] = (char) random_byte();
4192 ss
= s
->cur_prompt
->prompts
[0]->result
;
4194 logevent("Sending length-padded password");
4195 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4196 PKT_INT
, len
, PKT_DATA
, ss
, len
,
4197 PKTT_OTHER
, PKT_END
);
4200 * The server is believed unable to cope with
4201 * any of our password camouflage methods.
4204 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4205 logevent("Sending unpadded password");
4206 send_packet(ssh
, s
->pwpkt_type
,
4207 PKTT_PASSWORD
, PKT_INT
, len
,
4208 PKT_DATA
, s
->cur_prompt
->prompts
[0]->result
, len
,
4209 PKTT_OTHER
, PKT_END
);
4212 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4213 PKT_STR
, s
->cur_prompt
->prompts
[0]->result
,
4214 PKTT_OTHER
, PKT_END
);
4216 logevent("Sent password");
4217 free_prompts(s
->cur_prompt
);
4219 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
4220 if (flags
& FLAG_VERBOSE
)
4221 c_write_str(ssh
, "Access denied\r\n");
4222 logevent("Authentication refused");
4223 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
4224 bombout(("Strange packet received, type %d", pktin
->type
));
4230 if (s
->publickey_blob
) {
4231 sfree(s
->publickey_blob
);
4232 sfree(s
->publickey_comment
);
4235 logevent("Authentication successful");
4240 static void ssh_channel_try_eof(struct ssh_channel
*c
)
4243 assert(c
->pending_eof
); /* precondition for calling us */
4245 return; /* can't close: not even opened yet */
4246 if (ssh
->version
== 2 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0)
4247 return; /* can't send EOF: pending outgoing data */
4249 c
->pending_eof
= FALSE
; /* we're about to send it */
4250 if (ssh
->version
== 1) {
4251 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4253 c
->closes
|= CLOSES_SENT_EOF
;
4255 struct Packet
*pktout
;
4256 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
4257 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4258 ssh2_pkt_send(ssh
, pktout
);
4259 c
->closes
|= CLOSES_SENT_EOF
;
4260 ssh2_channel_check_close(c
);
4264 void sshfwd_write_eof(struct ssh_channel
*c
)
4268 if (ssh
->state
== SSH_STATE_CLOSED
)
4271 if (c
->closes
& CLOSES_SENT_EOF
)
4274 c
->pending_eof
= TRUE
;
4275 ssh_channel_try_eof(c
);
4278 void sshfwd_unclean_close(struct ssh_channel
*c
)
4282 if (ssh
->state
== SSH_STATE_CLOSED
)
4287 x11_close(c
->u
.x11
.s
);
4288 logevent("Forwarded X11 connection terminated due to local error");
4291 case CHAN_SOCKDATA_DORMANT
:
4292 pfd_close(c
->u
.pfd
.s
);
4293 logevent("Forwarded port closed due to local error");
4296 c
->type
= CHAN_ZOMBIE
;
4298 ssh2_channel_check_close(c
);
4301 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
4305 if (ssh
->state
== SSH_STATE_CLOSED
)
4308 if (ssh
->version
== 1) {
4309 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
4310 PKT_INT
, c
->remoteid
,
4311 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, buf
, len
,
4312 PKTT_OTHER
, PKT_END
);
4314 * In SSH-1 we can return 0 here - implying that forwarded
4315 * connections are never individually throttled - because
4316 * the only circumstance that can cause throttling will be
4317 * the whole SSH connection backing up, in which case
4318 * _everything_ will be throttled as a whole.
4322 ssh2_add_channel_data(c
, buf
, len
);
4323 return ssh2_try_send(c
);
4327 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
4332 if (ssh
->state
== SSH_STATE_CLOSED
)
4335 if (ssh
->version
== 1) {
4336 buflimit
= SSH1_BUFFER_LIMIT
;
4338 buflimit
= c
->v
.v2
.locmaxwin
;
4339 ssh2_set_window(c
, bufsize
< buflimit ? buflimit
- bufsize
: 0);
4341 if (c
->throttling_conn
&& bufsize
<= buflimit
) {
4342 c
->throttling_conn
= 0;
4343 ssh_throttle_conn(ssh
, -1);
4347 static void ssh_queueing_handler(Ssh ssh
, struct Packet
*pktin
)
4349 struct queued_handler
*qh
= ssh
->qhead
;
4353 assert(pktin
->type
== qh
->msg1
|| pktin
->type
== qh
->msg2
);
4356 assert(ssh
->packet_dispatch
[qh
->msg1
] == ssh_queueing_handler
);
4357 ssh
->packet_dispatch
[qh
->msg1
] = ssh
->q_saved_handler1
;
4360 assert(ssh
->packet_dispatch
[qh
->msg2
] == ssh_queueing_handler
);
4361 ssh
->packet_dispatch
[qh
->msg2
] = ssh
->q_saved_handler2
;
4365 ssh
->qhead
= qh
->next
;
4367 if (ssh
->qhead
->msg1
> 0) {
4368 ssh
->q_saved_handler1
= ssh
->packet_dispatch
[ssh
->qhead
->msg1
];
4369 ssh
->packet_dispatch
[ssh
->qhead
->msg1
] = ssh_queueing_handler
;
4371 if (ssh
->qhead
->msg2
> 0) {
4372 ssh
->q_saved_handler2
= ssh
->packet_dispatch
[ssh
->qhead
->msg2
];
4373 ssh
->packet_dispatch
[ssh
->qhead
->msg2
] = ssh_queueing_handler
;
4376 ssh
->qhead
= ssh
->qtail
= NULL
;
4379 qh
->handler(ssh
, pktin
, qh
->ctx
);
4384 static void ssh_queue_handler(Ssh ssh
, int msg1
, int msg2
,
4385 chandler_fn_t handler
, void *ctx
)
4387 struct queued_handler
*qh
;
4389 qh
= snew(struct queued_handler
);
4392 qh
->handler
= handler
;
4396 if (ssh
->qtail
== NULL
) {
4400 ssh
->q_saved_handler1
= ssh
->packet_dispatch
[ssh
->qhead
->msg1
];
4401 ssh
->packet_dispatch
[qh
->msg1
] = ssh_queueing_handler
;
4404 ssh
->q_saved_handler2
= ssh
->packet_dispatch
[ssh
->qhead
->msg2
];
4405 ssh
->packet_dispatch
[qh
->msg2
] = ssh_queueing_handler
;
4408 ssh
->qtail
->next
= qh
;
4413 static void ssh_rportfwd_succfail(Ssh ssh
, struct Packet
*pktin
, void *ctx
)
4415 struct ssh_rportfwd
*rpf
, *pf
= (struct ssh_rportfwd
*)ctx
;
4417 if (pktin
->type
== (ssh
->version
== 1 ? SSH1_SMSG_SUCCESS
:
4418 SSH2_MSG_REQUEST_SUCCESS
)) {
4419 logeventf(ssh
, "Remote port forwarding from %s enabled",
4422 logeventf(ssh
, "Remote port forwarding from %s refused",
4425 rpf
= del234(ssh
->rportfwds
, pf
);
4427 pf
->pfrec
->remote
= NULL
;
4432 static void ssh_setup_portfwd(Ssh ssh
, Conf
*conf
)
4434 struct ssh_portfwd
*epf
;
4438 if (!ssh
->portfwds
) {
4439 ssh
->portfwds
= newtree234(ssh_portcmp
);
4442 * Go through the existing port forwardings and tag them
4443 * with status==DESTROY. Any that we want to keep will be
4444 * re-enabled (status==KEEP) as we go through the
4445 * configuration and find out which bits are the same as
4448 struct ssh_portfwd
*epf
;
4450 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4451 epf
->status
= DESTROY
;
4454 for (val
= conf_get_str_strs(conf
, CONF_portfwd
, NULL
, &key
);
4456 val
= conf_get_str_strs(conf
, CONF_portfwd
, key
, &key
)) {
4457 char *kp
, *kp2
, *vp
, *vp2
;
4458 char address_family
, type
;
4459 int sport
,dport
,sserv
,dserv
;
4460 char *sports
, *dports
, *saddr
, *host
;
4464 address_family
= 'A';
4466 if (*kp
== 'A' || *kp
== '4' || *kp
== '6')
4467 address_family
= *kp
++;
4468 if (*kp
== 'L' || *kp
== 'R')
4471 if ((kp2
= strchr(kp
, ':')) != NULL
) {
4473 * There's a colon in the middle of the source port
4474 * string, which means that the part before it is
4475 * actually a source address.
4477 saddr
= dupprintf("%.*s", (int)(kp2
- kp
), kp
);
4483 sport
= atoi(sports
);
4487 sport
= net_service_lookup(sports
);
4489 logeventf(ssh
, "Service lookup failed for source"
4490 " port \"%s\"", sports
);
4494 if (type
== 'L' && !strcmp(val
, "D")) {
4495 /* dynamic forwarding */
4502 /* ordinary forwarding */
4504 vp2
= vp
+ strcspn(vp
, ":");
4505 host
= dupprintf("%.*s", (int)(vp2
- vp
), vp
);
4509 dport
= atoi(dports
);
4513 dport
= net_service_lookup(dports
);
4515 logeventf(ssh
, "Service lookup failed for destination"
4516 " port \"%s\"", dports
);
4521 if (sport
&& dport
) {
4522 /* Set up a description of the source port. */
4523 struct ssh_portfwd
*pfrec
, *epfrec
;
4525 pfrec
= snew(struct ssh_portfwd
);
4527 pfrec
->saddr
= saddr
;
4528 pfrec
->sserv
= sserv ?
dupstr(sports
) : NULL
;
4529 pfrec
->sport
= sport
;
4530 pfrec
->daddr
= host
;
4531 pfrec
->dserv
= dserv ?
dupstr(dports
) : NULL
;
4532 pfrec
->dport
= dport
;
4533 pfrec
->local
= NULL
;
4534 pfrec
->remote
= NULL
;
4535 pfrec
->addressfamily
= (address_family
== '4' ? ADDRTYPE_IPV4
:
4536 address_family
== '6' ? ADDRTYPE_IPV6
:
4539 epfrec
= add234(ssh
->portfwds
, pfrec
);
4540 if (epfrec
!= pfrec
) {
4541 if (epfrec
->status
== DESTROY
) {
4543 * We already have a port forwarding up and running
4544 * with precisely these parameters. Hence, no need
4545 * to do anything; simply re-tag the existing one
4548 epfrec
->status
= KEEP
;
4551 * Anything else indicates that there was a duplicate
4552 * in our input, which we'll silently ignore.
4554 free_portfwd(pfrec
);
4556 pfrec
->status
= CREATE
;
4565 * Now go through and destroy any port forwardings which were
4568 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4569 if (epf
->status
== DESTROY
) {
4572 message
= dupprintf("%s port forwarding from %s%s%d",
4573 epf
->type
== 'L' ?
"local" :
4574 epf
->type
== 'R' ?
"remote" : "dynamic",
4575 epf
->saddr ? epf
->saddr
: "",
4576 epf
->saddr ?
":" : "",
4579 if (epf
->type
!= 'D') {
4580 char *msg2
= dupprintf("%s to %s:%d", message
,
4581 epf
->daddr
, epf
->dport
);
4586 logeventf(ssh
, "Cancelling %s", message
);
4589 /* epf->remote or epf->local may be NULL if setting up a
4590 * forwarding failed. */
4592 struct ssh_rportfwd
*rpf
= epf
->remote
;
4593 struct Packet
*pktout
;
4596 * Cancel the port forwarding at the server
4599 if (ssh
->version
== 1) {
4601 * We cannot cancel listening ports on the
4602 * server side in SSH-1! There's no message
4603 * to support it. Instead, we simply remove
4604 * the rportfwd record from the local end
4605 * so that any connections the server tries
4606 * to make on it are rejected.
4609 pktout
= ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4610 ssh2_pkt_addstring(pktout
, "cancel-tcpip-forward");
4611 ssh2_pkt_addbool(pktout
, 0);/* _don't_ want reply */
4613 ssh2_pkt_addstring(pktout
, epf
->saddr
);
4614 } else if (conf_get_int(conf
, CONF_rport_acceptall
)) {
4615 /* XXX: rport_acceptall may not represent
4616 * what was used to open the original connection,
4617 * since it's reconfigurable. */
4618 ssh2_pkt_addstring(pktout
, "0.0.0.0");
4620 ssh2_pkt_addstring(pktout
, "127.0.0.1");
4622 ssh2_pkt_adduint32(pktout
, epf
->sport
);
4623 ssh2_pkt_send(ssh
, pktout
);
4626 del234(ssh
->rportfwds
, rpf
);
4628 } else if (epf
->local
) {
4629 pfd_terminate(epf
->local
);
4632 delpos234(ssh
->portfwds
, i
);
4634 i
--; /* so we don't skip one in the list */
4638 * And finally, set up any new port forwardings (status==CREATE).
4640 for (i
= 0; (epf
= index234(ssh
->portfwds
, i
)) != NULL
; i
++)
4641 if (epf
->status
== CREATE
) {
4642 char *sportdesc
, *dportdesc
;
4643 sportdesc
= dupprintf("%s%s%s%s%d%s",
4644 epf
->saddr ? epf
->saddr
: "",
4645 epf
->saddr ?
":" : "",
4646 epf
->sserv ? epf
->sserv
: "",
4647 epf
->sserv ?
"(" : "",
4649 epf
->sserv ?
")" : "");
4650 if (epf
->type
== 'D') {
4653 dportdesc
= dupprintf("%s:%s%s%d%s",
4655 epf
->dserv ? epf
->dserv
: "",
4656 epf
->dserv ?
"(" : "",
4658 epf
->dserv ?
")" : "");
4661 if (epf
->type
== 'L') {
4662 const char *err
= pfd_addforward(epf
->daddr
, epf
->dport
,
4663 epf
->saddr
, epf
->sport
,
4666 epf
->addressfamily
);
4668 logeventf(ssh
, "Local %sport %s forwarding to %s%s%s",
4669 epf
->addressfamily
== ADDRTYPE_IPV4 ?
"IPv4 " :
4670 epf
->addressfamily
== ADDRTYPE_IPV6 ?
"IPv6 " : "",
4671 sportdesc
, dportdesc
,
4672 err ?
" failed: " : "", err ? err
: "");
4673 } else if (epf
->type
== 'D') {
4674 const char *err
= pfd_addforward(NULL
, -1,
4675 epf
->saddr
, epf
->sport
,
4678 epf
->addressfamily
);
4680 logeventf(ssh
, "Local %sport %s SOCKS dynamic forwarding%s%s",
4681 epf
->addressfamily
== ADDRTYPE_IPV4 ?
"IPv4 " :
4682 epf
->addressfamily
== ADDRTYPE_IPV6 ?
"IPv6 " : "",
4684 err ?
" failed: " : "", err ? err
: "");
4686 struct ssh_rportfwd
*pf
;
4689 * Ensure the remote port forwardings tree exists.
4691 if (!ssh
->rportfwds
) {
4692 if (ssh
->version
== 1)
4693 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
4695 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4698 pf
= snew(struct ssh_rportfwd
);
4699 strncpy(pf
->dhost
, epf
->daddr
, lenof(pf
->dhost
)-1);
4700 pf
->dhost
[lenof(pf
->dhost
)-1] = '\0';
4701 pf
->dport
= epf
->dport
;
4702 pf
->sport
= epf
->sport
;
4703 if (add234(ssh
->rportfwds
, pf
) != pf
) {
4704 logeventf(ssh
, "Duplicate remote port forwarding to %s:%d",
4705 epf
->daddr
, epf
->dport
);
4708 logeventf(ssh
, "Requesting remote port %s"
4709 " forward to %s", sportdesc
, dportdesc
);
4711 pf
->sportdesc
= sportdesc
;
4716 if (ssh
->version
== 1) {
4717 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
4718 PKT_INT
, epf
->sport
,
4719 PKT_STR
, epf
->daddr
,
4720 PKT_INT
, epf
->dport
,
4722 ssh_queue_handler(ssh
, SSH1_SMSG_SUCCESS
,
4724 ssh_rportfwd_succfail
, pf
);
4726 struct Packet
*pktout
;
4727 pktout
= ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4728 ssh2_pkt_addstring(pktout
, "tcpip-forward");
4729 ssh2_pkt_addbool(pktout
, 1);/* want reply */
4731 ssh2_pkt_addstring(pktout
, epf
->saddr
);
4732 } else if (conf_get_int(conf
, CONF_rport_acceptall
)) {
4733 ssh2_pkt_addstring(pktout
, "0.0.0.0");
4735 ssh2_pkt_addstring(pktout
, "127.0.0.1");
4737 ssh2_pkt_adduint32(pktout
, epf
->sport
);
4738 ssh2_pkt_send(ssh
, pktout
);
4740 ssh_queue_handler(ssh
, SSH2_MSG_REQUEST_SUCCESS
,
4741 SSH2_MSG_REQUEST_FAILURE
,
4742 ssh_rportfwd_succfail
, pf
);
4751 static void ssh1_smsg_stdout_stderr_data(Ssh ssh
, struct Packet
*pktin
)
4754 int stringlen
, bufsize
;
4756 ssh_pkt_getstring(pktin
, &string
, &stringlen
);
4757 if (string
== NULL
) {
4758 bombout(("Incoming terminal data packet was badly formed"));
4762 bufsize
= from_backend(ssh
->frontend
, pktin
->type
== SSH1_SMSG_STDERR_DATA
,
4764 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
4765 ssh
->v1_stdout_throttling
= 1;
4766 ssh_throttle_conn(ssh
, +1);
4770 static void ssh1_smsg_x11_open(Ssh ssh
, struct Packet
*pktin
)
4772 /* Remote side is trying to open a channel to talk to our
4773 * X-Server. Give them back a local channel number. */
4774 struct ssh_channel
*c
;
4775 int remoteid
= ssh_pkt_getuint32(pktin
);
4777 logevent("Received X11 connect request");
4778 /* Refuse if X11 forwarding is disabled. */
4779 if (!ssh
->X11_fwd_enabled
) {
4780 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4781 PKT_INT
, remoteid
, PKT_END
);
4782 logevent("Rejected X11 connect request");
4784 c
= snew(struct ssh_channel
);
4787 if (x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
4788 NULL
, -1, ssh
->conf
) != NULL
) {
4789 logevent("Opening X11 forward connection failed");
4791 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4792 PKT_INT
, remoteid
, PKT_END
);
4795 ("Opening X11 forward connection succeeded");
4796 c
->remoteid
= remoteid
;
4797 c
->halfopen
= FALSE
;
4798 c
->localid
= alloc_channel_id(ssh
);
4800 c
->pending_eof
= FALSE
;
4801 c
->throttling_conn
= 0;
4802 c
->type
= CHAN_X11
; /* identify channel type */
4803 add234(ssh
->channels
, c
);
4804 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4805 PKT_INT
, c
->remoteid
, PKT_INT
,
4806 c
->localid
, PKT_END
);
4807 logevent("Opened X11 forward channel");
4812 static void ssh1_smsg_agent_open(Ssh ssh
, struct Packet
*pktin
)
4814 /* Remote side is trying to open a channel to talk to our
4815 * agent. Give them back a local channel number. */
4816 struct ssh_channel
*c
;
4817 int remoteid
= ssh_pkt_getuint32(pktin
);
4819 /* Refuse if agent forwarding is disabled. */
4820 if (!ssh
->agentfwd_enabled
) {
4821 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4822 PKT_INT
, remoteid
, PKT_END
);
4824 c
= snew(struct ssh_channel
);
4826 c
->remoteid
= remoteid
;
4827 c
->halfopen
= FALSE
;
4828 c
->localid
= alloc_channel_id(ssh
);
4830 c
->pending_eof
= FALSE
;
4831 c
->throttling_conn
= 0;
4832 c
->type
= CHAN_AGENT
; /* identify channel type */
4833 c
->u
.a
.lensofar
= 0;
4834 c
->u
.a
.message
= NULL
;
4835 add234(ssh
->channels
, c
);
4836 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4837 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
4842 static void ssh1_msg_port_open(Ssh ssh
, struct Packet
*pktin
)
4844 /* Remote side is trying to open a channel to talk to a
4845 * forwarded port. Give them back a local channel number. */
4846 struct ssh_channel
*c
;
4847 struct ssh_rportfwd pf
, *pfp
;
4852 c
= snew(struct ssh_channel
);
4855 remoteid
= ssh_pkt_getuint32(pktin
);
4856 ssh_pkt_getstring(pktin
, &host
, &hostsize
);
4857 port
= ssh_pkt_getuint32(pktin
);
4859 if (hostsize
>= lenof(pf
.dhost
))
4860 hostsize
= lenof(pf
.dhost
)-1;
4861 memcpy(pf
.dhost
, host
, hostsize
);
4862 pf
.dhost
[hostsize
] = '\0';
4864 pfp
= find234(ssh
->rportfwds
, &pf
, NULL
);
4867 logeventf(ssh
, "Rejected remote port open request for %s:%d",
4869 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4870 PKT_INT
, remoteid
, PKT_END
);
4872 logeventf(ssh
, "Received remote port open request for %s:%d",
4874 e
= pfd_newconnect(&c
->u
.pfd
.s
, pf
.dhost
, port
,
4875 c
, ssh
->conf
, pfp
->pfrec
->addressfamily
);
4877 logeventf(ssh
, "Port open failed: %s", e
);
4879 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
4880 PKT_INT
, remoteid
, PKT_END
);
4882 c
->remoteid
= remoteid
;
4883 c
->halfopen
= FALSE
;
4884 c
->localid
= alloc_channel_id(ssh
);
4886 c
->pending_eof
= FALSE
;
4887 c
->throttling_conn
= 0;
4888 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
4889 add234(ssh
->channels
, c
);
4890 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
4891 PKT_INT
, c
->remoteid
, PKT_INT
,
4892 c
->localid
, PKT_END
);
4893 logevent("Forwarded port opened successfully");
4898 static void ssh1_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
4900 unsigned int remoteid
= ssh_pkt_getuint32(pktin
);
4901 unsigned int localid
= ssh_pkt_getuint32(pktin
);
4902 struct ssh_channel
*c
;
4904 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
4905 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
4906 c
->remoteid
= localid
;
4907 c
->halfopen
= FALSE
;
4908 c
->type
= CHAN_SOCKDATA
;
4909 c
->throttling_conn
= 0;
4910 pfd_confirm(c
->u
.pfd
.s
);
4913 if (c
&& c
->pending_eof
) {
4915 * We have a pending close on this channel,
4916 * which we decided on before the server acked
4917 * the channel open. So now we know the
4918 * remoteid, we can close it again.
4920 ssh_channel_try_eof(c
);
4924 static void ssh1_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
4926 unsigned int remoteid
= ssh_pkt_getuint32(pktin
);
4927 struct ssh_channel
*c
;
4929 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
4930 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
4931 logevent("Forwarded connection refused by server");
4932 pfd_close(c
->u
.pfd
.s
);
4933 del234(ssh
->channels
, c
);
4938 static void ssh1_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
4940 /* Remote side closes a channel. */
4941 unsigned i
= ssh_pkt_getuint32(pktin
);
4942 struct ssh_channel
*c
;
4943 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
4944 if (c
&& !c
->halfopen
) {
4946 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE
&&
4947 !(c
->closes
& CLOSES_RCVD_EOF
)) {
4949 * Received CHANNEL_CLOSE, which we translate into
4952 int send_close
= FALSE
;
4954 c
->closes
|= CLOSES_RCVD_EOF
;
4959 x11_send_eof(c
->u
.x11
.s
);
4965 pfd_send_eof(c
->u
.pfd
.s
);
4974 if (send_close
&& !(c
->closes
& CLOSES_SENT_EOF
)) {
4975 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4977 c
->closes
|= CLOSES_SENT_EOF
;
4981 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
&&
4982 !(c
->closes
& CLOSES_RCVD_CLOSE
)) {
4984 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
4985 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4986 " for which we never sent CHANNEL_CLOSE\n", i
));
4989 c
->closes
|= CLOSES_RCVD_CLOSE
;
4992 if (!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
) &&
4993 !(c
->closes
& CLOSES_SENT_CLOSE
)) {
4994 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
,
4995 PKT_INT
, c
->remoteid
, PKT_END
);
4996 c
->closes
|= CLOSES_SENT_CLOSE
;
4999 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
))
5000 ssh_channel_destroy(c
);
5002 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5003 pktin
->type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
5004 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
5009 static void ssh1_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
5011 /* Data sent down one of our channels. */
5012 int i
= ssh_pkt_getuint32(pktin
);
5015 struct ssh_channel
*c
;
5017 ssh_pkt_getstring(pktin
, &p
, &len
);
5019 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5024 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
5027 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
5030 /* Data for an agent message. Buffer it. */
5032 if (c
->u
.a
.lensofar
< 4) {
5033 unsigned int l
= min(4 - c
->u
.a
.lensofar
, (unsigned)len
);
5034 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
5038 c
->u
.a
.lensofar
+= l
;
5040 if (c
->u
.a
.lensofar
== 4) {
5042 4 + GET_32BIT(c
->u
.a
.msglen
);
5043 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
5045 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5047 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
5049 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5051 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
5055 c
->u
.a
.lensofar
+= l
;
5057 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5060 if (agent_query(c
->u
.a
.message
,
5063 ssh_agentf_callback
, c
))
5064 ssh_agentf_callback(c
, reply
, replylen
);
5065 sfree(c
->u
.a
.message
);
5066 c
->u
.a
.lensofar
= 0;
5069 bufsize
= 0; /* agent channels never back up */
5072 if (!c
->throttling_conn
&& bufsize
> SSH1_BUFFER_LIMIT
) {
5073 c
->throttling_conn
= 1;
5074 ssh_throttle_conn(ssh
, +1);
5079 static void ssh1_smsg_exit_status(Ssh ssh
, struct Packet
*pktin
)
5081 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
5082 logeventf(ssh
, "Server sent command exit status %d", ssh
->exitcode
);
5083 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
5085 * In case `helpful' firewalls or proxies tack
5086 * extra human-readable text on the end of the
5087 * session which we might mistake for another
5088 * encrypted packet, we close the session once
5089 * we've sent EXIT_CONFIRMATION.
5091 ssh_disconnect(ssh
, NULL
, NULL
, 0, TRUE
);
5094 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5095 static void ssh1_send_ttymode(void *data
, char *mode
, char *val
)
5097 struct Packet
*pktout
= (struct Packet
*)data
;
5099 unsigned int arg
= 0;
5100 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
5101 if (i
== lenof(ssh_ttymodes
)) return;
5102 switch (ssh_ttymodes
[i
].type
) {
5104 arg
= ssh_tty_parse_specchar(val
);
5107 arg
= ssh_tty_parse_boolean(val
);
5110 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
5111 ssh2_pkt_addbyte(pktout
, arg
);
5115 static void do_ssh1_connection(Ssh ssh
, unsigned char *in
, int inlen
,
5116 struct Packet
*pktin
)
5118 crBegin(ssh
->do_ssh1_connection_crstate
);
5120 ssh
->packet_dispatch
[SSH1_SMSG_STDOUT_DATA
] =
5121 ssh
->packet_dispatch
[SSH1_SMSG_STDERR_DATA
] =
5122 ssh1_smsg_stdout_stderr_data
;
5124 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
] =
5125 ssh1_msg_channel_open_confirmation
;
5126 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_FAILURE
] =
5127 ssh1_msg_channel_open_failure
;
5128 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE
] =
5129 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
] =
5130 ssh1_msg_channel_close
;
5131 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_DATA
] = ssh1_msg_channel_data
;
5132 ssh
->packet_dispatch
[SSH1_SMSG_EXIT_STATUS
] = ssh1_smsg_exit_status
;
5134 if (conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
5135 logevent("Requesting agent forwarding");
5136 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
5140 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5141 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5142 bombout(("Protocol confusion"));
5144 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5145 logevent("Agent forwarding refused");
5147 logevent("Agent forwarding enabled");
5148 ssh
->agentfwd_enabled
= TRUE
;
5149 ssh
->packet_dispatch
[SSH1_SMSG_AGENT_OPEN
] = ssh1_smsg_agent_open
;
5153 if (conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
5154 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
5155 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
5156 logevent("Requesting X11 forwarding");
5158 * Note that while we blank the X authentication data here, we don't
5159 * take any special action to blank the start of an X11 channel,
5160 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5161 * without having session blanking enabled is likely to leak your
5162 * cookie into the log.
5164 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
5165 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5166 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5168 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5170 PKT_INT
, ssh
->x11disp
->screennum
,
5173 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5174 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5176 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5183 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5184 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5185 bombout(("Protocol confusion"));
5187 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5188 logevent("X11 forwarding refused");
5190 logevent("X11 forwarding enabled");
5191 ssh
->X11_fwd_enabled
= TRUE
;
5192 ssh
->packet_dispatch
[SSH1_SMSG_X11_OPEN
] = ssh1_smsg_x11_open
;
5196 ssh_setup_portfwd(ssh
, ssh
->conf
);
5197 ssh
->packet_dispatch
[SSH1_MSG_PORT_OPEN
] = ssh1_msg_port_open
;
5199 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
5201 /* Unpick the terminal-speed string. */
5202 /* XXX perhaps we should allow no speeds to be sent. */
5203 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
5204 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
5205 /* Send the pty request. */
5206 pkt
= ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY
);
5207 ssh_pkt_addstring(pkt
, conf_get_str(ssh
->conf
, CONF_termtype
));
5208 ssh_pkt_adduint32(pkt
, ssh
->term_height
);
5209 ssh_pkt_adduint32(pkt
, ssh
->term_width
);
5210 ssh_pkt_adduint32(pkt
, 0); /* width in pixels */
5211 ssh_pkt_adduint32(pkt
, 0); /* height in pixels */
5212 parse_ttymodes(ssh
, ssh1_send_ttymode
, (void *)pkt
);
5213 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_ISPEED
);
5214 ssh_pkt_adduint32(pkt
, ssh
->ispeed
);
5215 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_OSPEED
);
5216 ssh_pkt_adduint32(pkt
, ssh
->ospeed
);
5217 ssh_pkt_addbyte(pkt
, SSH_TTY_OP_END
);
5219 ssh
->state
= SSH_STATE_INTERMED
;
5223 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5224 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5225 bombout(("Protocol confusion"));
5227 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5228 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5229 ssh
->editing
= ssh
->echoing
= 1;
5231 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5232 ssh
->ospeed
, ssh
->ispeed
);
5233 ssh
->got_pty
= TRUE
;
5236 ssh
->editing
= ssh
->echoing
= 1;
5239 if (conf_get_int(ssh
->conf
, CONF_compression
)) {
5240 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
5244 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5245 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5246 bombout(("Protocol confusion"));
5248 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5249 c_write_str(ssh
, "Server refused to compress\r\n");
5251 logevent("Started compression");
5252 ssh
->v1_compressing
= TRUE
;
5253 ssh
->cs_comp_ctx
= zlib_compress_init();
5254 logevent("Initialised zlib (RFC1950) compression");
5255 ssh
->sc_comp_ctx
= zlib_decompress_init();
5256 logevent("Initialised zlib (RFC1950) decompression");
5260 * Start the shell or command.
5262 * Special case: if the first-choice command is an SSH-2
5263 * subsystem (hence not usable here) and the second choice
5264 * exists, we fall straight back to that.
5267 char *cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
5269 if (conf_get_int(ssh
->conf
, CONF_ssh_subsys
) &&
5270 conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
5271 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
5272 ssh
->fallback_cmd
= TRUE
;
5275 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
5277 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
5278 logevent("Started session");
5281 ssh
->state
= SSH_STATE_SESSION
;
5282 if (ssh
->size_needed
)
5283 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5284 if (ssh
->eof_needed
)
5285 ssh_special(ssh
, TS_EOF
);
5288 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5290 ssh
->channels
= newtree234(ssh_channelcmp
);
5294 * By this point, most incoming packets are already being
5295 * handled by the dispatch table, and we need only pay
5296 * attention to the unusual ones.
5301 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
5302 /* may be from EXEC_SHELL on some servers */
5303 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5304 /* may be from EXEC_SHELL on some servers
5305 * if no pty is available or in other odd cases. Ignore */
5307 bombout(("Strange packet received: type %d", pktin
->type
));
5312 int len
= min(inlen
, 512);
5313 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
5314 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, in
, len
,
5315 PKTT_OTHER
, PKT_END
);
5326 * Handle the top-level SSH-2 protocol.
5328 static void ssh1_msg_debug(Ssh ssh
, struct Packet
*pktin
)
5333 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5334 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
5337 static void ssh1_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
5339 /* log reason code in disconnect message */
5343 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5344 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen
, msg
));
5347 static void ssh_msg_ignore(Ssh ssh
, struct Packet
*pktin
)
5349 /* Do nothing, because we're ignoring it! Duhh. */
5352 static void ssh1_protocol_setup(Ssh ssh
)
5357 * Most messages are handled by the coroutines.
5359 for (i
= 0; i
< 256; i
++)
5360 ssh
->packet_dispatch
[i
] = NULL
;
5363 * These special message types we install handlers for.
5365 ssh
->packet_dispatch
[SSH1_MSG_DISCONNECT
] = ssh1_msg_disconnect
;
5366 ssh
->packet_dispatch
[SSH1_MSG_IGNORE
] = ssh_msg_ignore
;
5367 ssh
->packet_dispatch
[SSH1_MSG_DEBUG
] = ssh1_msg_debug
;
5370 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
5371 struct Packet
*pktin
)
5373 unsigned char *in
=(unsigned char*)vin
;
5374 if (ssh
->state
== SSH_STATE_CLOSED
)
5377 if (pktin
&& ssh
->packet_dispatch
[pktin
->type
]) {
5378 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
5382 if (!ssh
->protocol_initial_phase_done
) {
5383 if (do_ssh1_login(ssh
, in
, inlen
, pktin
))
5384 ssh
->protocol_initial_phase_done
= TRUE
;
5389 do_ssh1_connection(ssh
, in
, inlen
, pktin
);
5393 * Utility routine for decoding comma-separated strings in KEXINIT.
5395 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
5398 if (!needle
|| !haystack
) /* protect against null pointers */
5400 needlen
= strlen(needle
);
5403 * Is it at the start of the string?
5405 if (haylen
>= needlen
&& /* haystack is long enough */
5406 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5407 (haylen
== needlen
|| haystack
[needlen
] == ',')
5408 /* either , or EOS follows */
5412 * If not, search for the next comma and resume after that.
5413 * If no comma found, terminate.
5415 while (haylen
> 0 && *haystack
!= ',')
5416 haylen
--, haystack
++;
5419 haylen
--, haystack
++; /* skip over comma itself */
5424 * Similar routine for checking whether we have the first string in a list.
5426 static int first_in_commasep_string(char *needle
, char *haystack
, int haylen
)
5429 if (!needle
|| !haystack
) /* protect against null pointers */
5431 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 */
5446 * SSH-2 key creation method.
5447 * (Currently assumes 2 lots of any hash are sufficient to generate
5448 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5450 #define SSH2_MKKEY_ITERS (2)
5451 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
, char chr
,
5452 unsigned char *keyspace
)
5454 const struct ssh_hash
*h
= ssh
->kex
->hash
;
5456 /* First hlen bytes. */
5458 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5459 hash_mpint(h
, s
, K
);
5460 h
->bytes(s
, H
, h
->hlen
);
5461 h
->bytes(s
, &chr
, 1);
5462 h
->bytes(s
, ssh
->v2_session_id
, ssh
->v2_session_id_len
);
5463 h
->final(s
, keyspace
);
5464 /* Next hlen bytes. */
5466 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5467 hash_mpint(h
, s
, K
);
5468 h
->bytes(s
, H
, h
->hlen
);
5469 h
->bytes(s
, keyspace
, h
->hlen
);
5470 h
->final(s
, keyspace
+ h
->hlen
);
5474 * Handle the SSH-2 transport layer.
5476 static int do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
5477 struct Packet
*pktin
)
5479 unsigned char *in
= (unsigned char *)vin
;
5480 struct do_ssh2_transport_state
{
5482 int nbits
, pbits
, warn_kex
, warn_cscipher
, warn_sccipher
;
5483 Bignum p
, g
, e
, f
, K
;
5486 int kex_init_value
, kex_reply_value
;
5487 const struct ssh_mac
**maclist
;
5489 const struct ssh2_cipher
*cscipher_tobe
;
5490 const struct ssh2_cipher
*sccipher_tobe
;
5491 const struct ssh_mac
*csmac_tobe
;
5492 const struct ssh_mac
*scmac_tobe
;
5493 const struct ssh_compress
*cscomp_tobe
;
5494 const struct ssh_compress
*sccomp_tobe
;
5495 char *hostkeydata
, *sigdata
, *rsakeydata
, *keystr
, *fingerprint
;
5496 int hostkeylen
, siglen
, rsakeylen
;
5497 void *hkey
; /* actual host key */
5498 void *rsakey
; /* for RSA kex */
5499 unsigned char exchange_hash
[SSH2_KEX_MAX_HASH_LEN
];
5500 int n_preferred_kex
;
5501 const struct ssh_kexes
*preferred_kex
[KEX_MAX
];
5502 int n_preferred_ciphers
;
5503 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
5504 const struct ssh_compress
*preferred_comp
;
5505 int userauth_succeeded
; /* for delayed compression */
5506 int pending_compression
;
5507 int got_session_id
, activated_authconn
;
5508 struct Packet
*pktout
;
5513 crState(do_ssh2_transport_state
);
5517 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
5518 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
5519 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
5521 s
->got_session_id
= s
->activated_authconn
= FALSE
;
5522 s
->userauth_succeeded
= FALSE
;
5523 s
->pending_compression
= FALSE
;
5526 * Be prepared to work around the buggy MAC problem.
5528 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
5529 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
5531 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
5534 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
5536 int i
, j
, k
, commalist_started
;
5539 * Set up the preferred key exchange. (NULL => warn below here)
5541 s
->n_preferred_kex
= 0;
5542 for (i
= 0; i
< KEX_MAX
; i
++) {
5543 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_kexlist
, i
)) {
5545 s
->preferred_kex
[s
->n_preferred_kex
++] =
5546 &ssh_diffiehellman_gex
;
5549 s
->preferred_kex
[s
->n_preferred_kex
++] =
5550 &ssh_diffiehellman_group14
;
5553 s
->preferred_kex
[s
->n_preferred_kex
++] =
5554 &ssh_diffiehellman_group1
;
5557 s
->preferred_kex
[s
->n_preferred_kex
++] =
5561 /* Flag for later. Don't bother if it's the last in
5563 if (i
< KEX_MAX
- 1) {
5564 s
->preferred_kex
[s
->n_preferred_kex
++] = NULL
;
5571 * Set up the preferred ciphers. (NULL => warn below here)
5573 s
->n_preferred_ciphers
= 0;
5574 for (i
= 0; i
< CIPHER_MAX
; i
++) {
5575 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
)) {
5576 case CIPHER_BLOWFISH
:
5577 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
5580 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
)) {
5581 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
5585 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
5588 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
5590 case CIPHER_ARCFOUR
:
5591 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_arcfour
;
5594 /* Flag for later. Don't bother if it's the last in
5596 if (i
< CIPHER_MAX
- 1) {
5597 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
5604 * Set up preferred compression.
5606 if (conf_get_int(ssh
->conf
, CONF_compression
))
5607 s
->preferred_comp
= &ssh_zlib
;
5609 s
->preferred_comp
= &ssh_comp_none
;
5612 * Enable queueing of outgoing auth- or connection-layer
5613 * packets while we are in the middle of a key exchange.
5615 ssh
->queueing
= TRUE
;
5618 * Flag that KEX is in progress.
5620 ssh
->kex_in_progress
= TRUE
;
5623 * Construct and send our key exchange packet.
5625 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXINIT
);
5626 for (i
= 0; i
< 16; i
++)
5627 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) random_byte());
5628 /* List key exchange algorithms. */
5629 ssh2_pkt_addstring_start(s
->pktout
);
5630 commalist_started
= 0;
5631 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5632 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5633 if (!k
) continue; /* warning flag */
5634 for (j
= 0; j
< k
->nkexes
; j
++) {
5635 if (commalist_started
)
5636 ssh2_pkt_addstring_str(s
->pktout
, ",");
5637 ssh2_pkt_addstring_str(s
->pktout
, k
->list
[j
]->name
);
5638 commalist_started
= 1;
5641 /* List server host key algorithms. */
5642 ssh2_pkt_addstring_start(s
->pktout
);
5643 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5644 ssh2_pkt_addstring_str(s
->pktout
, hostkey_algs
[i
]->name
);
5645 if (i
< lenof(hostkey_algs
) - 1)
5646 ssh2_pkt_addstring_str(s
->pktout
, ",");
5648 /* List encryption algorithms (client->server then server->client). */
5649 for (k
= 0; k
< 2; k
++) {
5650 ssh2_pkt_addstring_start(s
->pktout
);
5651 commalist_started
= 0;
5652 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5653 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5654 if (!c
) continue; /* warning flag */
5655 for (j
= 0; j
< c
->nciphers
; j
++) {
5656 if (commalist_started
)
5657 ssh2_pkt_addstring_str(s
->pktout
, ",");
5658 ssh2_pkt_addstring_str(s
->pktout
, c
->list
[j
]->name
);
5659 commalist_started
= 1;
5663 /* List MAC algorithms (client->server then server->client). */
5664 for (j
= 0; j
< 2; j
++) {
5665 ssh2_pkt_addstring_start(s
->pktout
);
5666 for (i
= 0; i
< s
->nmacs
; i
++) {
5667 ssh2_pkt_addstring_str(s
->pktout
, s
->maclist
[i
]->name
);
5668 if (i
< s
->nmacs
- 1)
5669 ssh2_pkt_addstring_str(s
->pktout
, ",");
5672 /* List client->server compression algorithms,
5673 * then server->client compression algorithms. (We use the
5674 * same set twice.) */
5675 for (j
= 0; j
< 2; j
++) {
5676 ssh2_pkt_addstring_start(s
->pktout
);
5677 assert(lenof(compressions
) > 1);
5678 /* Prefer non-delayed versions */
5679 ssh2_pkt_addstring_str(s
->pktout
, s
->preferred_comp
->name
);
5680 /* We don't even list delayed versions of algorithms until
5681 * they're allowed to be used, to avoid a race. See the end of
5683 if (s
->userauth_succeeded
&& s
->preferred_comp
->delayed_name
) {
5684 ssh2_pkt_addstring_str(s
->pktout
, ",");
5685 ssh2_pkt_addstring_str(s
->pktout
,
5686 s
->preferred_comp
->delayed_name
);
5688 for (i
= 0; i
< lenof(compressions
); i
++) {
5689 const struct ssh_compress
*c
= compressions
[i
];
5690 if (c
!= s
->preferred_comp
) {
5691 ssh2_pkt_addstring_str(s
->pktout
, ",");
5692 ssh2_pkt_addstring_str(s
->pktout
, c
->name
);
5693 if (s
->userauth_succeeded
&& c
->delayed_name
) {
5694 ssh2_pkt_addstring_str(s
->pktout
, ",");
5695 ssh2_pkt_addstring_str(s
->pktout
, c
->delayed_name
);
5700 /* List client->server languages. Empty list. */
5701 ssh2_pkt_addstring_start(s
->pktout
);
5702 /* List server->client languages. Empty list. */
5703 ssh2_pkt_addstring_start(s
->pktout
);
5704 /* First KEX packet does _not_ follow, because we're not that brave. */
5705 ssh2_pkt_addbool(s
->pktout
, FALSE
);
5707 ssh2_pkt_adduint32(s
->pktout
, 0);
5710 s
->our_kexinitlen
= s
->pktout
->length
- 5;
5711 s
->our_kexinit
= snewn(s
->our_kexinitlen
, unsigned char);
5712 memcpy(s
->our_kexinit
, s
->pktout
->data
+ 5, s
->our_kexinitlen
);
5714 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
5720 * Now examine the other side's KEXINIT to see what we're up
5724 char *str
, *preferred
;
5727 if (pktin
->type
!= SSH2_MSG_KEXINIT
) {
5728 bombout(("expected key exchange packet from server"));
5732 ssh
->hostkey
= NULL
;
5733 s
->cscipher_tobe
= NULL
;
5734 s
->sccipher_tobe
= NULL
;
5735 s
->csmac_tobe
= NULL
;
5736 s
->scmac_tobe
= NULL
;
5737 s
->cscomp_tobe
= NULL
;
5738 s
->sccomp_tobe
= NULL
;
5739 s
->warn_kex
= s
->warn_cscipher
= s
->warn_sccipher
= FALSE
;
5741 pktin
->savedpos
+= 16; /* skip garbage cookie */
5742 ssh_pkt_getstring(pktin
, &str
, &len
); /* key exchange algorithms */
5745 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5746 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5750 for (j
= 0; j
< k
->nkexes
; j
++) {
5751 if (!preferred
) preferred
= k
->list
[j
]->name
;
5752 if (in_commasep_string(k
->list
[j
]->name
, str
, len
)) {
5753 ssh
->kex
= k
->list
[j
];
5762 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5763 str ? str
: "(null)"));
5767 * Note that the server's guess is considered wrong if it doesn't match
5768 * the first algorithm in our list, even if it's still the algorithm
5771 s
->guessok
= first_in_commasep_string(preferred
, str
, len
);
5772 ssh_pkt_getstring(pktin
, &str
, &len
); /* host key algorithms */
5773 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5774 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
5775 ssh
->hostkey
= hostkey_algs
[i
];
5779 if (!ssh
->hostkey
) {
5780 bombout(("Couldn't agree a host key algorithm (available: %s)",
5781 str ? str
: "(null)"));
5785 s
->guessok
= s
->guessok
&&
5786 first_in_commasep_string(hostkey_algs
[0]->name
, str
, len
);
5787 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server cipher */
5788 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5789 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5791 s
->warn_cscipher
= TRUE
;
5793 for (j
= 0; j
< c
->nciphers
; j
++) {
5794 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5795 s
->cscipher_tobe
= c
->list
[j
];
5800 if (s
->cscipher_tobe
)
5803 if (!s
->cscipher_tobe
) {
5804 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5805 str ? str
: "(null)"));
5809 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client cipher */
5810 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5811 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5813 s
->warn_sccipher
= TRUE
;
5815 for (j
= 0; j
< c
->nciphers
; j
++) {
5816 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5817 s
->sccipher_tobe
= c
->list
[j
];
5822 if (s
->sccipher_tobe
)
5825 if (!s
->sccipher_tobe
) {
5826 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5827 str ? str
: "(null)"));
5831 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server mac */
5832 for (i
= 0; i
< s
->nmacs
; i
++) {
5833 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5834 s
->csmac_tobe
= s
->maclist
[i
];
5838 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client mac */
5839 for (i
= 0; i
< s
->nmacs
; i
++) {
5840 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5841 s
->scmac_tobe
= s
->maclist
[i
];
5845 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server compression */
5846 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5847 const struct ssh_compress
*c
=
5848 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5849 if (in_commasep_string(c
->name
, str
, len
)) {
5852 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5853 if (s
->userauth_succeeded
) {
5857 s
->pending_compression
= TRUE
; /* try this later */
5861 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client compression */
5862 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5863 const struct ssh_compress
*c
=
5864 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5865 if (in_commasep_string(c
->name
, str
, len
)) {
5868 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5869 if (s
->userauth_succeeded
) {
5873 s
->pending_compression
= TRUE
; /* try this later */
5877 if (s
->pending_compression
) {
5878 logevent("Server supports delayed compression; "
5879 "will try this later");
5881 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server language */
5882 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client language */
5883 s
->ignorepkt
= ssh2_pkt_getbool(pktin
) && !s
->guessok
;
5886 ssh_set_frozen(ssh
, 1);
5887 s
->dlgret
= askalg(ssh
->frontend
, "key-exchange algorithm",
5889 ssh_dialog_callback
, ssh
);
5890 if (s
->dlgret
< 0) {
5894 bombout(("Unexpected data from server while"
5895 " waiting for user response"));
5898 } while (pktin
|| inlen
> 0);
5899 s
->dlgret
= ssh
->user_response
;
5901 ssh_set_frozen(ssh
, 0);
5902 if (s
->dlgret
== 0) {
5903 ssh_disconnect(ssh
, "User aborted at kex warning", NULL
,
5909 if (s
->warn_cscipher
) {
5910 ssh_set_frozen(ssh
, 1);
5911 s
->dlgret
= askalg(ssh
->frontend
,
5912 "client-to-server cipher",
5913 s
->cscipher_tobe
->name
,
5914 ssh_dialog_callback
, ssh
);
5915 if (s
->dlgret
< 0) {
5919 bombout(("Unexpected data from server while"
5920 " waiting for user response"));
5923 } while (pktin
|| inlen
> 0);
5924 s
->dlgret
= ssh
->user_response
;
5926 ssh_set_frozen(ssh
, 0);
5927 if (s
->dlgret
== 0) {
5928 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5934 if (s
->warn_sccipher
) {
5935 ssh_set_frozen(ssh
, 1);
5936 s
->dlgret
= askalg(ssh
->frontend
,
5937 "server-to-client cipher",
5938 s
->sccipher_tobe
->name
,
5939 ssh_dialog_callback
, ssh
);
5940 if (s
->dlgret
< 0) {
5944 bombout(("Unexpected data from server while"
5945 " waiting for user response"));
5948 } while (pktin
|| inlen
> 0);
5949 s
->dlgret
= ssh
->user_response
;
5951 ssh_set_frozen(ssh
, 0);
5952 if (s
->dlgret
== 0) {
5953 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5959 ssh
->exhash
= ssh
->kex
->hash
->init();
5960 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_c
, strlen(ssh
->v_c
));
5961 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_s
, strlen(ssh
->v_s
));
5962 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5963 s
->our_kexinit
, s
->our_kexinitlen
);
5964 sfree(s
->our_kexinit
);
5965 if (pktin
->length
> 5)
5966 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5967 pktin
->data
+ 5, pktin
->length
- 5);
5969 if (s
->ignorepkt
) /* first_kex_packet_follows */
5970 crWaitUntil(pktin
); /* Ignore packet */
5973 if (ssh
->kex
->main_type
== KEXTYPE_DH
) {
5975 * Work out the number of bits of key we will need from the
5976 * key exchange. We start with the maximum key length of
5982 csbits
= s
->cscipher_tobe
->keylen
;
5983 scbits
= s
->sccipher_tobe
->keylen
;
5984 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
5986 /* The keys only have hlen-bit entropy, since they're based on
5987 * a hash. So cap the key size at hlen bits. */
5988 if (s
->nbits
> ssh
->kex
->hash
->hlen
* 8)
5989 s
->nbits
= ssh
->kex
->hash
->hlen
* 8;
5992 * If we're doing Diffie-Hellman group exchange, start by
5993 * requesting a group.
5995 if (!ssh
->kex
->pdata
) {
5996 logevent("Doing Diffie-Hellman group exchange");
5997 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGEX
;
5999 * Work out how big a DH group we will need to allow that
6002 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
6003 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
6004 ssh2_pkt_adduint32(s
->pktout
, s
->pbits
);
6005 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6008 if (pktin
->type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
6009 bombout(("expected key exchange group packet from server"));
6012 s
->p
= ssh2_pkt_getmp(pktin
);
6013 s
->g
= ssh2_pkt_getmp(pktin
);
6014 if (!s
->p
|| !s
->g
) {
6015 bombout(("unable to read mp-ints from incoming group packet"));
6018 ssh
->kex_ctx
= dh_setup_gex(s
->p
, s
->g
);
6019 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
6020 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
6022 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGROUP
;
6023 ssh
->kex_ctx
= dh_setup_group(ssh
->kex
);
6024 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
6025 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
6026 logeventf(ssh
, "Using Diffie-Hellman with standard group \"%s\"",
6027 ssh
->kex
->groupname
);
6030 logeventf(ssh
, "Doing Diffie-Hellman key exchange with hash %s",
6031 ssh
->kex
->hash
->text_name
);
6033 * Now generate and send e for Diffie-Hellman.
6035 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* this can take a while */
6036 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
6037 s
->pktout
= ssh2_pkt_init(s
->kex_init_value
);
6038 ssh2_pkt_addmp(s
->pktout
, s
->e
);
6039 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6041 set_busy_status(ssh
->frontend
, BUSY_WAITING
); /* wait for server */
6043 if (pktin
->type
!= s
->kex_reply_value
) {
6044 bombout(("expected key exchange reply packet from server"));
6047 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* cogitate */
6048 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6049 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6050 s
->f
= ssh2_pkt_getmp(pktin
);
6052 bombout(("unable to parse key exchange reply packet"));
6055 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6057 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
6059 /* We assume everything from now on will be quick, and it might
6060 * involve user interaction. */
6061 set_busy_status(ssh
->frontend
, BUSY_NOT
);
6063 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
6064 if (!ssh
->kex
->pdata
) {
6065 hash_uint32(ssh
->kex
->hash
, ssh
->exhash
, s
->pbits
);
6066 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->p
);
6067 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->g
);
6069 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->e
);
6070 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->f
);
6072 dh_cleanup(ssh
->kex_ctx
);
6074 if (!ssh
->kex
->pdata
) {
6079 logeventf(ssh
, "Doing RSA key exchange with hash %s",
6080 ssh
->kex
->hash
->text_name
);
6081 ssh
->pkt_kctx
= SSH2_PKTCTX_RSAKEX
;
6083 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6087 if (pktin
->type
!= SSH2_MSG_KEXRSA_PUBKEY
) {
6088 bombout(("expected RSA public key packet from server"));
6092 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6093 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
6094 s
->hostkeydata
, s
->hostkeylen
);
6095 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6099 ssh_pkt_getstring(pktin
, &keydata
, &s
->rsakeylen
);
6100 s
->rsakeydata
= snewn(s
->rsakeylen
, char);
6101 memcpy(s
->rsakeydata
, keydata
, s
->rsakeylen
);
6104 s
->rsakey
= ssh_rsakex_newkey(s
->rsakeydata
, s
->rsakeylen
);
6106 sfree(s
->rsakeydata
);
6107 bombout(("unable to parse RSA public key from server"));
6111 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->rsakeydata
, s
->rsakeylen
);
6114 * Next, set up a shared secret K, of precisely KLEN -
6115 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6116 * RSA key modulus and HLEN is the bit length of the hash
6120 int klen
= ssh_rsakex_klen(s
->rsakey
);
6121 int nbits
= klen
- (2*ssh
->kex
->hash
->hlen
*8 + 49);
6123 unsigned char *kstr1
, *kstr2
, *outstr
;
6124 int kstr1len
, kstr2len
, outstrlen
;
6126 s
->K
= bn_power_2(nbits
- 1);
6128 for (i
= 0; i
< nbits
; i
++) {
6130 byte
= random_byte();
6132 bignum_set_bit(s
->K
, i
, (byte
>> (i
& 7)) & 1);
6136 * Encode this as an mpint.
6138 kstr1
= ssh2_mpint_fmt(s
->K
, &kstr1len
);
6139 kstr2
= snewn(kstr2len
= 4 + kstr1len
, unsigned char);
6140 PUT_32BIT(kstr2
, kstr1len
);
6141 memcpy(kstr2
+ 4, kstr1
, kstr1len
);
6144 * Encrypt it with the given RSA key.
6146 outstrlen
= (klen
+ 7) / 8;
6147 outstr
= snewn(outstrlen
, unsigned char);
6148 ssh_rsakex_encrypt(ssh
->kex
->hash
, kstr2
, kstr2len
,
6149 outstr
, outstrlen
, s
->rsakey
);
6152 * And send it off in a return packet.
6154 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET
);
6155 ssh2_pkt_addstring_start(s
->pktout
);
6156 ssh2_pkt_addstring_data(s
->pktout
, (char *)outstr
, outstrlen
);
6157 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6159 hash_string(ssh
->kex
->hash
, ssh
->exhash
, outstr
, outstrlen
);
6166 ssh_rsakex_freekey(s
->rsakey
);
6169 if (pktin
->type
!= SSH2_MSG_KEXRSA_DONE
) {
6170 sfree(s
->rsakeydata
);
6171 bombout(("expected signature packet from server"));
6175 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6177 sfree(s
->rsakeydata
);
6180 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->K
);
6181 assert(ssh
->kex
->hash
->hlen
<= sizeof(s
->exchange_hash
));
6182 ssh
->kex
->hash
->final(ssh
->exhash
, s
->exchange_hash
);
6184 ssh
->kex_ctx
= NULL
;
6187 debug(("Exchange hash is:\n"));
6188 dmemdump(s
->exchange_hash
, ssh
->kex
->hash
->hlen
);
6192 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
6193 (char *)s
->exchange_hash
,
6194 ssh
->kex
->hash
->hlen
)) {
6195 bombout(("Server's host key did not match the signature supplied"));
6200 * Authenticate remote host: verify host key. (We've already
6201 * checked the signature of the exchange hash.)
6203 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
6204 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
6205 ssh_set_frozen(ssh
, 1);
6206 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
6207 ssh
->savedhost
, ssh
->savedport
,
6208 ssh
->hostkey
->keytype
, s
->keystr
,
6210 ssh_dialog_callback
, ssh
);
6211 if (s
->dlgret
< 0) {
6215 bombout(("Unexpected data from server while waiting"
6216 " for user host key response"));
6219 } while (pktin
|| inlen
> 0);
6220 s
->dlgret
= ssh
->user_response
;
6222 ssh_set_frozen(ssh
, 0);
6223 if (s
->dlgret
== 0) {
6224 ssh_disconnect(ssh
, "User aborted at host key verification", NULL
,
6228 if (!s
->got_session_id
) { /* don't bother logging this in rekeys */
6229 logevent("Host key fingerprint is:");
6230 logevent(s
->fingerprint
);
6232 sfree(s
->fingerprint
);
6234 ssh
->hostkey
->freekey(s
->hkey
);
6237 * The exchange hash from the very first key exchange is also
6238 * the session id, used in session key construction and
6241 if (!s
->got_session_id
) {
6242 assert(sizeof(s
->exchange_hash
) <= sizeof(ssh
->v2_session_id
));
6243 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
6244 sizeof(s
->exchange_hash
));
6245 ssh
->v2_session_id_len
= ssh
->kex
->hash
->hlen
;
6246 assert(ssh
->v2_session_id_len
<= sizeof(ssh
->v2_session_id
));
6247 s
->got_session_id
= TRUE
;
6251 * Send SSH2_MSG_NEWKEYS.
6253 s
->pktout
= ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
6254 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6255 ssh
->outgoing_data_size
= 0; /* start counting from here */
6258 * We've sent client NEWKEYS, so create and initialise
6259 * client-to-server session keys.
6261 if (ssh
->cs_cipher_ctx
)
6262 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
6263 ssh
->cscipher
= s
->cscipher_tobe
;
6264 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
6266 if (ssh
->cs_mac_ctx
)
6267 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
6268 ssh
->csmac
= s
->csmac_tobe
;
6269 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
6271 if (ssh
->cs_comp_ctx
)
6272 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
6273 ssh
->cscomp
= s
->cscomp_tobe
;
6274 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
6277 * Set IVs on client-to-server keys. Here we use the exchange
6278 * hash from the _first_ key exchange.
6281 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6282 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6283 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'C',keyspace
);
6284 assert((ssh
->cscipher
->keylen
+7) / 8 <=
6285 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6286 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
6287 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'A',keyspace
);
6288 assert(ssh
->cscipher
->blksize
<=
6289 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6290 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
6291 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'E',keyspace
);
6292 assert(ssh
->csmac
->len
<=
6293 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6294 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
6295 smemclr(keyspace
, sizeof(keyspace
));
6298 logeventf(ssh
, "Initialised %.200s client->server encryption",
6299 ssh
->cscipher
->text_name
);
6300 logeventf(ssh
, "Initialised %.200s client->server MAC algorithm",
6301 ssh
->csmac
->text_name
);
6302 if (ssh
->cscomp
->text_name
)
6303 logeventf(ssh
, "Initialised %s compression",
6304 ssh
->cscomp
->text_name
);
6307 * Now our end of the key exchange is complete, we can send all
6308 * our queued higher-layer packets.
6310 ssh
->queueing
= FALSE
;
6311 ssh2_pkt_queuesend(ssh
);
6314 * Expect SSH2_MSG_NEWKEYS from server.
6317 if (pktin
->type
!= SSH2_MSG_NEWKEYS
) {
6318 bombout(("expected new-keys packet from server"));
6321 ssh
->incoming_data_size
= 0; /* start counting from here */
6324 * We've seen server NEWKEYS, so create and initialise
6325 * server-to-client session keys.
6327 if (ssh
->sc_cipher_ctx
)
6328 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
6329 ssh
->sccipher
= s
->sccipher_tobe
;
6330 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
6332 if (ssh
->sc_mac_ctx
)
6333 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
6334 ssh
->scmac
= s
->scmac_tobe
;
6335 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
6337 if (ssh
->sc_comp_ctx
)
6338 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
6339 ssh
->sccomp
= s
->sccomp_tobe
;
6340 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
6343 * Set IVs on server-to-client keys. Here we use the exchange
6344 * hash from the _first_ key exchange.
6347 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6348 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6349 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'D',keyspace
);
6350 assert((ssh
->sccipher
->keylen
+7) / 8 <=
6351 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6352 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
6353 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'B',keyspace
);
6354 assert(ssh
->sccipher
->blksize
<=
6355 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6356 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
6357 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'F',keyspace
);
6358 assert(ssh
->scmac
->len
<=
6359 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6360 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
6361 smemclr(keyspace
, sizeof(keyspace
));
6363 logeventf(ssh
, "Initialised %.200s server->client encryption",
6364 ssh
->sccipher
->text_name
);
6365 logeventf(ssh
, "Initialised %.200s server->client MAC algorithm",
6366 ssh
->scmac
->text_name
);
6367 if (ssh
->sccomp
->text_name
)
6368 logeventf(ssh
, "Initialised %s decompression",
6369 ssh
->sccomp
->text_name
);
6372 * Free shared secret.
6377 * Key exchange is over. Loop straight back round if we have a
6378 * deferred rekey reason.
6380 if (ssh
->deferred_rekey_reason
) {
6381 logevent(ssh
->deferred_rekey_reason
);
6383 ssh
->deferred_rekey_reason
= NULL
;
6384 goto begin_key_exchange
;
6388 * Otherwise, schedule a timer for our next rekey.
6390 ssh
->kex_in_progress
= FALSE
;
6391 ssh
->last_rekey
= GETTICKCOUNT();
6392 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0)
6393 ssh
->next_rekey
= schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6397 * Now we're encrypting. Begin returning 1 to the protocol main
6398 * function so that other things can run on top of the
6399 * transport. If we ever see a KEXINIT, we must go back to the
6402 * We _also_ go back to the start if we see pktin==NULL and
6403 * inlen negative, because this is a special signal meaning
6404 * `initiate client-driven rekey', and `in' contains a message
6405 * giving the reason for the rekey.
6407 * inlen==-1 means always initiate a rekey;
6408 * inlen==-2 means that userauth has completed successfully and
6409 * we should consider rekeying (for delayed compression).
6411 while (!((pktin
&& pktin
->type
== SSH2_MSG_KEXINIT
) ||
6412 (!pktin
&& inlen
< 0))) {
6414 if (!ssh
->protocol_initial_phase_done
) {
6415 ssh
->protocol_initial_phase_done
= TRUE
;
6417 * Allow authconn to initialise itself.
6419 do_ssh2_authconn(ssh
, NULL
, 0, NULL
);
6424 logevent("Server initiated key re-exchange");
6428 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6429 * delayed compression, if it's available.
6431 * draft-miller-secsh-compression-delayed-00 says that you
6432 * negotiate delayed compression in the first key exchange, and
6433 * both sides start compressing when the server has sent
6434 * USERAUTH_SUCCESS. This has a race condition -- the server
6435 * can't know when the client has seen it, and thus which incoming
6436 * packets it should treat as compressed.
6438 * Instead, we do the initial key exchange without offering the
6439 * delayed methods, but note if the server offers them; when we
6440 * get here, if a delayed method was available that was higher
6441 * on our list than what we got, we initiate a rekey in which we
6442 * _do_ list the delayed methods (and hopefully get it as a
6443 * result). Subsequent rekeys will do the same.
6445 assert(!s
->userauth_succeeded
); /* should only happen once */
6446 s
->userauth_succeeded
= TRUE
;
6447 if (!s
->pending_compression
)
6448 /* Can't see any point rekeying. */
6449 goto wait_for_rekey
; /* this is utterly horrid */
6450 /* else fall through to rekey... */
6451 s
->pending_compression
= FALSE
;
6454 * Now we've decided to rekey.
6456 * Special case: if the server bug is set that doesn't
6457 * allow rekeying, we give a different log message and
6458 * continue waiting. (If such a server _initiates_ a rekey,
6459 * we process it anyway!)
6461 if ((ssh
->remote_bugs
& BUG_SSH2_REKEY
)) {
6462 logeventf(ssh
, "Server bug prevents key re-exchange (%s)",
6464 /* Reset the counters, so that at least this message doesn't
6465 * hit the event log _too_ often. */
6466 ssh
->outgoing_data_size
= 0;
6467 ssh
->incoming_data_size
= 0;
6468 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0) {
6470 schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6473 goto wait_for_rekey
; /* this is still utterly horrid */
6475 logeventf(ssh
, "Initiating key re-exchange (%s)", (char *)in
);
6478 goto begin_key_exchange
;
6484 * Add data to an SSH-2 channel output buffer.
6486 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
6489 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
6493 * Attempt to send data on an SSH-2 channel.
6495 static int ssh2_try_send(struct ssh_channel
*c
)
6498 struct Packet
*pktout
;
6501 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
6504 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
6505 if ((unsigned)len
> c
->v
.v2
.remwindow
)
6506 len
= c
->v
.v2
.remwindow
;
6507 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
6508 len
= c
->v
.v2
.remmaxpkt
;
6509 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
6510 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6511 ssh2_pkt_addstring_start(pktout
);
6512 dont_log_data(ssh
, pktout
, PKTLOG_OMIT
);
6513 ssh2_pkt_addstring_data(pktout
, data
, len
);
6514 end_log_omission(ssh
, pktout
);
6515 ssh2_pkt_send(ssh
, pktout
);
6516 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
6517 c
->v
.v2
.remwindow
-= len
;
6521 * After having sent as much data as we can, return the amount
6524 ret
= bufchain_size(&c
->v
.v2
.outbuffer
);
6527 * And if there's no data pending but we need to send an EOF, send
6530 if (!ret
&& c
->pending_eof
)
6531 ssh_channel_try_eof(c
);
6536 static void ssh2_try_send_and_unthrottle(Ssh ssh
, struct ssh_channel
*c
)
6539 if (c
->closes
& CLOSES_SENT_EOF
)
6540 return; /* don't send on channels we've EOFed */
6541 bufsize
= ssh2_try_send(c
);
6544 case CHAN_MAINSESSION
:
6545 /* stdin need not receive an unthrottle
6546 * notification since it will be polled */
6549 x11_unthrottle(c
->u
.x11
.s
);
6552 /* agent sockets are request/response and need no
6553 * buffer management */
6556 pfd_unthrottle(c
->u
.pfd
.s
);
6563 * Set up most of a new ssh_channel for SSH-2.
6565 static void ssh2_channel_init(struct ssh_channel
*c
)
6568 c
->localid
= alloc_channel_id(ssh
);
6570 c
->pending_eof
= FALSE
;
6571 c
->throttling_conn
= FALSE
;
6572 c
->v
.v2
.locwindow
= c
->v
.v2
.locmaxwin
= c
->v
.v2
.remlocwin
=
6573 conf_get_int(ssh
->conf
, CONF_ssh_simple
) ? OUR_V2_BIGWIN
: OUR_V2_WINSIZE
;
6574 c
->v
.v2
.chanreq_head
= NULL
;
6575 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6576 bufchain_init(&c
->v
.v2
.outbuffer
);
6580 * CHANNEL_FAILURE doesn't come with any indication of what message
6581 * caused it, so we have to keep track of the outstanding
6582 * CHANNEL_REQUESTs ourselves.
6584 static void ssh2_queue_chanreq_handler(struct ssh_channel
*c
,
6585 cchandler_fn_t handler
, void *ctx
)
6587 struct outstanding_channel_request
*ocr
=
6588 snew(struct outstanding_channel_request
);
6590 assert(!(c
->closes
& (CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
)));
6591 ocr
->handler
= handler
;
6594 if (!c
->v
.v2
.chanreq_head
)
6595 c
->v
.v2
.chanreq_head
= ocr
;
6597 c
->v
.v2
.chanreq_tail
->next
= ocr
;
6598 c
->v
.v2
.chanreq_tail
= ocr
;
6602 * Construct the common parts of a CHANNEL_REQUEST. If handler is not
6603 * NULL then a reply will be requested and the handler will be called
6604 * when it arrives. The returned packet is ready to have any
6605 * request-specific data added and be sent. Note that if a handler is
6606 * provided, it's essential that the request actually be sent.
6608 * The handler will usually be passed the response packet in pktin.
6609 * If pktin is NULL, this means that no reply will ever be forthcoming
6610 * (e.g. because the entire connection is being destroyed) and the
6611 * handler should free any storage it's holding.
6613 static struct Packet
*ssh2_chanreq_init(struct ssh_channel
*c
, char *type
,
6614 cchandler_fn_t handler
, void *ctx
)
6616 struct Packet
*pktout
;
6618 assert(!(c
->closes
& (CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
)));
6619 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
6620 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6621 ssh2_pkt_addstring(pktout
, type
);
6622 ssh2_pkt_addbool(pktout
, handler
!= NULL
);
6623 if (handler
!= NULL
)
6624 ssh2_queue_chanreq_handler(c
, handler
, ctx
);
6629 * Potentially enlarge the window on an SSH-2 channel.
6631 static void ssh2_handle_winadj_response(struct ssh_channel
*, struct Packet
*,
6633 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
)
6638 * Never send WINDOW_ADJUST for a channel that the remote side has
6639 * already sent EOF on; there's no point, since it won't be
6640 * sending any more data anyway. Ditto if _we've_ already sent
6643 if (c
->closes
& (CLOSES_RCVD_EOF
| CLOSES_SENT_CLOSE
))
6647 * If the remote end has a habit of ignoring maxpkt, limit the
6648 * window so that it has no choice (assuming it doesn't ignore the
6651 if ((ssh
->remote_bugs
& BUG_SSH2_MAXPKT
) && newwin
> OUR_V2_MAXPKT
)
6652 newwin
= OUR_V2_MAXPKT
;
6655 * Only send a WINDOW_ADJUST if there's significantly more window
6656 * available than the other end thinks there is. This saves us
6657 * sending a WINDOW_ADJUST for every character in a shell session.
6659 * "Significant" is arbitrarily defined as half the window size.
6661 if (newwin
/ 2 >= c
->v
.v2
.locwindow
) {
6662 struct Packet
*pktout
;
6666 * In order to keep track of how much window the client
6667 * actually has available, we'd like it to acknowledge each
6668 * WINDOW_ADJUST. We can't do that directly, so we accompany
6669 * it with a CHANNEL_REQUEST that has to be acknowledged.
6671 * This is only necessary if we're opening the window wide.
6672 * If we're not, then throughput is being constrained by
6673 * something other than the maximum window size anyway.
6675 if (newwin
== c
->v
.v2
.locmaxwin
&&
6676 !(ssh
->remote_bugs
& BUG_CHOKES_ON_WINADJ
)) {
6677 up
= snew(unsigned);
6678 *up
= newwin
- c
->v
.v2
.locwindow
;
6679 pktout
= ssh2_chanreq_init(c
, "winadj@putty.projects.tartarus.org",
6680 ssh2_handle_winadj_response
, up
);
6681 ssh2_pkt_send(ssh
, pktout
);
6683 if (c
->v
.v2
.throttle_state
!= UNTHROTTLED
)
6684 c
->v
.v2
.throttle_state
= UNTHROTTLING
;
6686 /* Pretend the WINDOW_ADJUST was acked immediately. */
6687 c
->v
.v2
.remlocwin
= newwin
;
6688 c
->v
.v2
.throttle_state
= THROTTLED
;
6690 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
6691 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6692 ssh2_pkt_adduint32(pktout
, newwin
- c
->v
.v2
.locwindow
);
6693 ssh2_pkt_send(ssh
, pktout
);
6694 c
->v
.v2
.locwindow
= newwin
;
6699 * Find the channel associated with a message. If there's no channel,
6700 * or it's not properly open, make a noise about it and return NULL.
6702 static struct ssh_channel
*ssh2_channel_msg(Ssh ssh
, struct Packet
*pktin
)
6704 unsigned localid
= ssh_pkt_getuint32(pktin
);
6705 struct ssh_channel
*c
;
6707 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
6709 (c
->halfopen
&& pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
&&
6710 pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_FAILURE
)) {
6711 char *buf
= dupprintf("Received %s for %s channel %u",
6712 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
6714 c ?
"half-open" : "nonexistent", localid
);
6715 ssh_disconnect(ssh
, NULL
, buf
, SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6722 static void ssh2_handle_winadj_response(struct ssh_channel
*c
,
6723 struct Packet
*pktin
, void *ctx
)
6725 unsigned *sizep
= ctx
;
6728 * Winadj responses should always be failures. However, at least
6729 * one server ("boks_sshd") is known to return SUCCESS for channel
6730 * requests it's never heard of, such as "winadj@putty". Raised
6731 * with foxt.com as bug 090916-090424, but for the sake of a quiet
6732 * life, we don't worry about what kind of response we got.
6735 c
->v
.v2
.remlocwin
+= *sizep
;
6738 * winadj messages are only sent when the window is fully open, so
6739 * if we get an ack of one, we know any pending unthrottle is
6742 if (c
->v
.v2
.throttle_state
== UNTHROTTLING
)
6743 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6746 static void ssh2_msg_channel_response(Ssh ssh
, struct Packet
*pktin
)
6748 struct ssh_channel
*c
= ssh2_channel_msg(ssh
, pktin
);
6749 struct outstanding_channel_request
*ocr
;
6752 ocr
= c
->v
.v2
.chanreq_head
;
6754 ssh2_msg_unexpected(ssh
, pktin
);
6757 ocr
->handler(c
, pktin
, ocr
->ctx
);
6758 c
->v
.v2
.chanreq_head
= ocr
->next
;
6761 * We may now initiate channel-closing procedures, if that
6762 * CHANNEL_REQUEST was the last thing outstanding before we send
6765 ssh2_channel_check_close(c
);
6768 static void ssh2_msg_channel_window_adjust(Ssh ssh
, struct Packet
*pktin
)
6770 struct ssh_channel
*c
;
6771 c
= ssh2_channel_msg(ssh
, pktin
);
6774 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
6775 c
->v
.v2
.remwindow
+= ssh_pkt_getuint32(pktin
);
6776 ssh2_try_send_and_unthrottle(ssh
, c
);
6780 static void ssh2_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
6784 struct ssh_channel
*c
;
6785 c
= ssh2_channel_msg(ssh
, pktin
);
6788 if (pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
6789 ssh_pkt_getuint32(pktin
) != SSH2_EXTENDED_DATA_STDERR
)
6790 return; /* extended but not stderr */
6791 ssh_pkt_getstring(pktin
, &data
, &length
);
6794 c
->v
.v2
.locwindow
-= length
;
6795 c
->v
.v2
.remlocwin
-= length
;
6797 case CHAN_MAINSESSION
:
6799 from_backend(ssh
->frontend
, pktin
->type
==
6800 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
6804 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
6807 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
6810 while (length
> 0) {
6811 if (c
->u
.a
.lensofar
< 4) {
6812 unsigned int l
= min(4 - c
->u
.a
.lensofar
,
6814 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
6818 c
->u
.a
.lensofar
+= l
;
6820 if (c
->u
.a
.lensofar
== 4) {
6822 4 + GET_32BIT(c
->u
.a
.msglen
);
6823 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
6825 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
6827 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
6829 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
6831 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
6835 c
->u
.a
.lensofar
+= l
;
6837 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
6840 if (agent_query(c
->u
.a
.message
,
6843 ssh_agentf_callback
, c
))
6844 ssh_agentf_callback(c
, reply
, replylen
);
6845 sfree(c
->u
.a
.message
);
6846 c
->u
.a
.message
= NULL
;
6847 c
->u
.a
.lensofar
= 0;
6854 * If it looks like the remote end hit the end of its window,
6855 * and we didn't want it to do that, think about using a
6858 if (c
->v
.v2
.remlocwin
<= 0 && c
->v
.v2
.throttle_state
== UNTHROTTLED
&&
6859 c
->v
.v2
.locmaxwin
< 0x40000000)
6860 c
->v
.v2
.locmaxwin
+= OUR_V2_WINSIZE
;
6862 * If we are not buffering too much data,
6863 * enlarge the window again at the remote side.
6864 * If we are buffering too much, we may still
6865 * need to adjust the window if the server's
6868 ssh2_set_window(c
, bufsize
< c
->v
.v2
.locmaxwin ?
6869 c
->v
.v2
.locmaxwin
- bufsize
: 0);
6871 * If we're either buffering way too much data, or if we're
6872 * buffering anything at all and we're in "simple" mode,
6873 * throttle the whole channel.
6875 if ((bufsize
> c
->v
.v2
.locmaxwin
||
6876 (conf_get_int(ssh
->conf
, CONF_ssh_simple
) && bufsize
> 0)) &&
6877 !c
->throttling_conn
) {
6878 c
->throttling_conn
= 1;
6879 ssh_throttle_conn(ssh
, +1);
6884 static void ssh_channel_destroy(struct ssh_channel
*c
)
6889 case CHAN_MAINSESSION
:
6890 ssh
->mainchan
= NULL
;
6891 update_specials_menu(ssh
->frontend
);
6894 if (c
->u
.x11
.s
!= NULL
)
6895 x11_close(c
->u
.x11
.s
);
6896 logevent("Forwarded X11 connection terminated");
6899 sfree(c
->u
.a
.message
);
6902 if (c
->u
.pfd
.s
!= NULL
)
6903 pfd_close(c
->u
.pfd
.s
);
6904 logevent("Forwarded port closed");
6908 del234(ssh
->channels
, c
);
6909 if (ssh
->version
== 2) {
6910 bufchain_clear(&c
->v
.v2
.outbuffer
);
6911 assert(c
->v
.v2
.chanreq_head
== NULL
);
6916 * See if that was the last channel left open.
6917 * (This is only our termination condition if we're
6918 * not running in -N mode.)
6920 if (ssh
->version
== 2 &&
6921 !conf_get_int(ssh
->conf
, CONF_ssh_no_shell
) &&
6922 count234(ssh
->channels
) == 0) {
6924 * We used to send SSH_MSG_DISCONNECT here,
6925 * because I'd believed that _every_ conforming
6926 * SSH-2 connection had to end with a disconnect
6927 * being sent by at least one side; apparently
6928 * I was wrong and it's perfectly OK to
6929 * unceremoniously slam the connection shut
6930 * when you're done, and indeed OpenSSH feels
6931 * this is more polite than sending a
6932 * DISCONNECT. So now we don't.
6934 ssh_disconnect(ssh
, "All channels closed", NULL
, 0, TRUE
);
6938 static void ssh2_channel_check_close(struct ssh_channel
*c
)
6941 struct Packet
*pktout
;
6943 if ((!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
) ||
6944 c
->type
== CHAN_ZOMBIE
) &&
6945 !c
->v
.v2
.chanreq_head
&&
6946 !(c
->closes
& CLOSES_SENT_CLOSE
)) {
6948 * We have both sent and received EOF (or the channel is a
6949 * zombie), and we have no outstanding channel requests, which
6950 * means the channel is in final wind-up. But we haven't sent
6951 * CLOSE, so let's do so now.
6953 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
6954 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6955 ssh2_pkt_send(ssh
, pktout
);
6956 c
->closes
|= CLOSES_SENT_EOF
| CLOSES_SENT_CLOSE
;
6959 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
)) {
6960 assert(c
->v
.v2
.chanreq_head
== NULL
);
6962 * We have both sent and received CLOSE, which means we're
6963 * completely done with the channel.
6965 ssh_channel_destroy(c
);
6969 static void ssh2_channel_got_eof(struct ssh_channel
*c
)
6971 if (c
->closes
& CLOSES_RCVD_EOF
)
6972 return; /* already seen EOF */
6973 c
->closes
|= CLOSES_RCVD_EOF
;
6975 if (c
->type
== CHAN_X11
) {
6976 x11_send_eof(c
->u
.x11
.s
);
6977 } else if (c
->type
== CHAN_AGENT
) {
6978 /* Manufacture an outgoing EOF in response to the incoming one. */
6979 sshfwd_write_eof(c
);
6980 } else if (c
->type
== CHAN_SOCKDATA
) {
6981 pfd_send_eof(c
->u
.pfd
.s
);
6982 } else if (c
->type
== CHAN_MAINSESSION
) {
6985 if (!ssh
->sent_console_eof
&&
6986 (from_backend_eof(ssh
->frontend
) || ssh
->got_pty
)) {
6988 * Either from_backend_eof told us that the front end
6989 * wants us to close the outgoing side of the connection
6990 * as soon as we see EOF from the far end, or else we've
6991 * unilaterally decided to do that because we've allocated
6992 * a remote pty and hence EOF isn't a particularly
6993 * meaningful concept.
6995 sshfwd_write_eof(c
);
6997 ssh
->sent_console_eof
= TRUE
;
7000 ssh2_channel_check_close(c
);
7003 static void ssh2_msg_channel_eof(Ssh ssh
, struct Packet
*pktin
)
7005 struct ssh_channel
*c
;
7007 c
= ssh2_channel_msg(ssh
, pktin
);
7010 ssh2_channel_got_eof(c
);
7013 static void ssh2_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
7015 struct ssh_channel
*c
;
7017 c
= ssh2_channel_msg(ssh
, pktin
);
7022 * When we receive CLOSE on a channel, we assume it comes with an
7023 * implied EOF if we haven't seen EOF yet.
7025 ssh2_channel_got_eof(c
);
7028 * And we also send an outgoing EOF, if we haven't already, on the
7029 * assumption that CLOSE is a pretty forceful announcement that
7030 * the remote side is doing away with the entire channel. (If it
7031 * had wanted to send us EOF and continue receiving data from us,
7032 * it would have just sent CHANNEL_EOF.)
7034 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
7036 * Make sure we don't read any more from whatever our local
7037 * data source is for this channel.
7040 case CHAN_MAINSESSION
:
7041 ssh
->send_ok
= 0; /* stop trying to read from stdin */
7044 x11_override_throttle(c
->u
.x11
.s
, 1);
7047 pfd_override_throttle(c
->u
.pfd
.s
, 1);
7052 * Send outgoing EOF.
7054 sshfwd_write_eof(c
);
7058 * Now process the actual close.
7060 if (!(c
->closes
& CLOSES_RCVD_CLOSE
)) {
7061 c
->closes
|= CLOSES_RCVD_CLOSE
;
7062 ssh2_channel_check_close(c
);
7066 static void ssh2_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
7068 struct ssh_channel
*c
;
7070 c
= ssh2_channel_msg(ssh
, pktin
);
7073 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7074 return; /* dunno why they're confirming this */
7075 c
->remoteid
= ssh_pkt_getuint32(pktin
);
7076 c
->halfopen
= FALSE
;
7077 c
->type
= CHAN_SOCKDATA
;
7078 c
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
7079 c
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
7081 pfd_confirm(c
->u
.pfd
.s
);
7083 ssh_channel_try_eof(c
);
7086 static void ssh2_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
7088 static const char *const reasons
[] = {
7089 "<unknown reason code>",
7090 "Administratively prohibited",
7092 "Unknown channel type",
7093 "Resource shortage",
7095 unsigned reason_code
;
7096 char *reason_string
;
7098 struct ssh_channel
*c
;
7099 c
= ssh2_channel_msg(ssh
, pktin
);
7102 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7103 return; /* dunno why they're failing this */
7105 reason_code
= ssh_pkt_getuint32(pktin
);
7106 if (reason_code
>= lenof(reasons
))
7107 reason_code
= 0; /* ensure reasons[reason_code] in range */
7108 ssh_pkt_getstring(pktin
, &reason_string
, &reason_length
);
7109 logeventf(ssh
, "Forwarded connection refused by server: %s [%.*s]",
7110 reasons
[reason_code
], reason_length
, reason_string
);
7112 pfd_close(c
->u
.pfd
.s
);
7114 del234(ssh
->channels
, c
);
7118 static void ssh2_msg_channel_request(Ssh ssh
, struct Packet
*pktin
)
7121 int typelen
, want_reply
;
7122 int reply
= SSH2_MSG_CHANNEL_FAILURE
; /* default */
7123 struct ssh_channel
*c
;
7124 struct Packet
*pktout
;
7126 c
= ssh2_channel_msg(ssh
, pktin
);
7129 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7130 want_reply
= ssh2_pkt_getbool(pktin
);
7133 * Having got the channel number, we now look at
7134 * the request type string to see if it's something
7137 if (c
== ssh
->mainchan
) {
7139 * We recognise "exit-status" and "exit-signal" on
7140 * the primary channel.
7142 if (typelen
== 11 &&
7143 !memcmp(type
, "exit-status", 11)) {
7145 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
7146 logeventf(ssh
, "Server sent command exit status %d",
7148 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7150 } else if (typelen
== 11 &&
7151 !memcmp(type
, "exit-signal", 11)) {
7153 int is_plausible
= TRUE
, is_int
= FALSE
;
7154 char *fmt_sig
= "", *fmt_msg
= "";
7156 int msglen
= 0, core
= FALSE
;
7157 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7158 * provide an `int' for the signal, despite its
7159 * having been a `string' in the drafts of RFC 4254 since at
7160 * least 2001. (Fixed in session.c 1.147.) Try to
7161 * infer which we can safely parse it as. */
7163 unsigned char *p
= pktin
->body
+
7165 long len
= pktin
->length
- pktin
->savedpos
;
7166 unsigned long num
= GET_32BIT(p
); /* what is it? */
7167 /* If it's 0, it hardly matters; assume string */
7171 int maybe_int
= FALSE
, maybe_str
= FALSE
;
7172 #define CHECK_HYPOTHESIS(offset, result) \
7175 if (q >= 0 && q+4 <= len) { \
7176 q = q + 4 + GET_32BIT(p+q); \
7177 if (q >= 0 && q+4 <= len && \
7178 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
7182 CHECK_HYPOTHESIS(4+1, maybe_int
);
7183 CHECK_HYPOTHESIS(4+num
+1, maybe_str
);
7184 #undef CHECK_HYPOTHESIS
7185 if (maybe_int
&& !maybe_str
)
7187 else if (!maybe_int
&& maybe_str
)
7190 /* Crikey. Either or neither. Panic. */
7191 is_plausible
= FALSE
;
7194 ssh
->exitcode
= 128; /* means `unknown signal' */
7197 /* Old non-standard OpenSSH. */
7198 int signum
= ssh_pkt_getuint32(pktin
);
7199 fmt_sig
= dupprintf(" %d", signum
);
7200 ssh
->exitcode
= 128 + signum
;
7202 /* As per RFC 4254. */
7205 ssh_pkt_getstring(pktin
, &sig
, &siglen
);
7206 /* Signal name isn't supposed to be blank, but
7207 * let's cope gracefully if it is. */
7209 fmt_sig
= dupprintf(" \"%.*s\"",
7214 * Really hideous method of translating the
7215 * signal description back into a locally
7216 * meaningful number.
7221 #define TRANSLATE_SIGNAL(s) \
7222 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7223 ssh->exitcode = 128 + SIG ## s
7225 TRANSLATE_SIGNAL(ABRT
);
7228 TRANSLATE_SIGNAL(ALRM
);
7231 TRANSLATE_SIGNAL(FPE
);
7234 TRANSLATE_SIGNAL(HUP
);
7237 TRANSLATE_SIGNAL(ILL
);
7240 TRANSLATE_SIGNAL(INT
);
7243 TRANSLATE_SIGNAL(KILL
);
7246 TRANSLATE_SIGNAL(PIPE
);
7249 TRANSLATE_SIGNAL(QUIT
);
7252 TRANSLATE_SIGNAL(SEGV
);
7255 TRANSLATE_SIGNAL(TERM
);
7258 TRANSLATE_SIGNAL(USR1
);
7261 TRANSLATE_SIGNAL(USR2
);
7263 #undef TRANSLATE_SIGNAL
7265 ssh
->exitcode
= 128;
7267 core
= ssh2_pkt_getbool(pktin
);
7268 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
7270 fmt_msg
= dupprintf(" (\"%.*s\")", msglen
, msg
);
7272 /* ignore lang tag */
7273 } /* else don't attempt to parse */
7274 logeventf(ssh
, "Server exited on signal%s%s%s",
7275 fmt_sig
, core ?
" (core dumped)" : "",
7277 if (*fmt_sig
) sfree(fmt_sig
);
7278 if (*fmt_msg
) sfree(fmt_msg
);
7279 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7284 * This is a channel request we don't know
7285 * about, so we now either ignore the request
7286 * or respond with CHANNEL_FAILURE, depending
7289 reply
= SSH2_MSG_CHANNEL_FAILURE
;
7292 pktout
= ssh2_pkt_init(reply
);
7293 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7294 ssh2_pkt_send(ssh
, pktout
);
7298 static void ssh2_msg_global_request(Ssh ssh
, struct Packet
*pktin
)
7301 int typelen
, want_reply
;
7302 struct Packet
*pktout
;
7304 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7305 want_reply
= ssh2_pkt_getbool(pktin
);
7308 * We currently don't support any global requests
7309 * at all, so we either ignore the request or
7310 * respond with REQUEST_FAILURE, depending on
7314 pktout
= ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
7315 ssh2_pkt_send(ssh
, pktout
);
7319 static void ssh2_msg_channel_open(Ssh ssh
, struct Packet
*pktin
)
7327 struct ssh_channel
*c
;
7328 unsigned remid
, winsize
, pktsize
;
7329 struct Packet
*pktout
;
7331 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7332 c
= snew(struct ssh_channel
);
7335 remid
= ssh_pkt_getuint32(pktin
);
7336 winsize
= ssh_pkt_getuint32(pktin
);
7337 pktsize
= ssh_pkt_getuint32(pktin
);
7339 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
7343 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7344 addrstr
= snewn(peeraddrlen
+1, char);
7345 memcpy(addrstr
, peeraddr
, peeraddrlen
);
7346 addrstr
[peeraddrlen
] = '\0';
7347 peerport
= ssh_pkt_getuint32(pktin
);
7349 logeventf(ssh
, "Received X11 connect request from %s:%d",
7352 if (!ssh
->X11_fwd_enabled
)
7353 error
= "X11 forwarding is not enabled";
7354 else if ((x11err
= x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
7355 addrstr
, peerport
, ssh
->conf
)) != NULL
) {
7356 logeventf(ssh
, "Local X11 connection failed: %s", x11err
);
7357 error
= "Unable to open an X11 connection";
7359 logevent("Opening X11 forward connection succeeded");
7364 } else if (typelen
== 15 &&
7365 !memcmp(type
, "forwarded-tcpip", 15)) {
7366 struct ssh_rportfwd pf
, *realpf
;
7369 ssh_pkt_getstring(pktin
, &dummy
, &dummylen
);/* skip address */
7370 pf
.sport
= ssh_pkt_getuint32(pktin
);
7371 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7372 peerport
= ssh_pkt_getuint32(pktin
);
7373 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
7374 logeventf(ssh
, "Received remote port %d open request "
7375 "from %s:%d", pf
.sport
, peeraddr
, peerport
);
7376 if (realpf
== NULL
) {
7377 error
= "Remote port is not recognised";
7379 const char *e
= pfd_newconnect(&c
->u
.pfd
.s
,
7383 realpf
->pfrec
->addressfamily
);
7384 logeventf(ssh
, "Attempting to forward remote port to "
7385 "%s:%d", realpf
->dhost
, realpf
->dport
);
7387 logeventf(ssh
, "Port open failed: %s", e
);
7388 error
= "Port open failed";
7390 logevent("Forwarded port opened successfully");
7391 c
->type
= CHAN_SOCKDATA
;
7394 } else if (typelen
== 22 &&
7395 !memcmp(type
, "auth-agent@openssh.com", 22)) {
7396 if (!ssh
->agentfwd_enabled
)
7397 error
= "Agent forwarding is not enabled";
7399 c
->type
= CHAN_AGENT
; /* identify channel type */
7400 c
->u
.a
.lensofar
= 0;
7403 error
= "Unsupported channel type requested";
7406 c
->remoteid
= remid
;
7407 c
->halfopen
= FALSE
;
7409 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
7410 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7411 ssh2_pkt_adduint32(pktout
, SSH2_OPEN_CONNECT_FAILED
);
7412 ssh2_pkt_addstring(pktout
, error
);
7413 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
7414 ssh2_pkt_send(ssh
, pktout
);
7415 logeventf(ssh
, "Rejected channel open: %s", error
);
7418 ssh2_channel_init(c
);
7419 c
->v
.v2
.remwindow
= winsize
;
7420 c
->v
.v2
.remmaxpkt
= pktsize
;
7421 add234(ssh
->channels
, c
);
7422 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
7423 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7424 ssh2_pkt_adduint32(pktout
, c
->localid
);
7425 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);
7426 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
7427 ssh2_pkt_send(ssh
, pktout
);
7432 * Buffer banner messages for later display at some convenient point,
7433 * if we're going to display them.
7435 static void ssh2_msg_userauth_banner(Ssh ssh
, struct Packet
*pktin
)
7437 /* Arbitrary limit to prevent unbounded inflation of buffer */
7438 if (conf_get_int(ssh
->conf
, CONF_ssh_show_banner
) &&
7439 bufchain_size(&ssh
->banner
) <= 131072) {
7440 char *banner
= NULL
;
7442 ssh_pkt_getstring(pktin
, &banner
, &size
);
7444 bufchain_add(&ssh
->banner
, banner
, size
);
7448 /* Helper function to deal with sending tty modes for "pty-req" */
7449 static void ssh2_send_ttymode(void *data
, char *mode
, char *val
)
7451 struct Packet
*pktout
= (struct Packet
*)data
;
7453 unsigned int arg
= 0;
7454 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
7455 if (i
== lenof(ssh_ttymodes
)) return;
7456 switch (ssh_ttymodes
[i
].type
) {
7458 arg
= ssh_tty_parse_specchar(val
);
7461 arg
= ssh_tty_parse_boolean(val
);
7464 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
7465 ssh2_pkt_adduint32(pktout
, arg
);
7468 static void ssh2_maybe_setup_x11(struct ssh_channel
*c
, struct Packet
*pktin
,
7471 struct ssh2_maybe_setup_x11_state
{
7475 struct Packet
*pktout
;
7476 crStateP(ssh2_maybe_setup_x11_state
, ctx
);
7481 * Potentially enable X11 forwarding.
7483 if (ssh
->mainchan
&& !ssh
->ncmode
&& conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
7484 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
7485 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
7486 logevent("Requesting X11 forwarding");
7487 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "x11-req",
7488 ssh2_maybe_setup_x11
, s
);
7489 ssh2_pkt_addbool(pktout
, 0); /* many connections */
7490 ssh2_pkt_addstring(pktout
, ssh
->x11disp
->remoteauthprotoname
);
7492 * Note that while we blank the X authentication data here, we don't
7493 * take any special action to blank the start of an X11 channel,
7494 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7495 * without having session blanking enabled is likely to leak your
7496 * cookie into the log.
7498 dont_log_password(ssh
, pktout
, PKTLOG_BLANK
);
7499 ssh2_pkt_addstring(pktout
, ssh
->x11disp
->remoteauthdatastring
);
7500 end_log_omission(ssh
, pktout
);
7501 ssh2_pkt_adduint32(pktout
, ssh
->x11disp
->screennum
);
7502 ssh2_pkt_send(ssh
, pktout
);
7504 crWaitUntilV(pktin
);
7507 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7508 logevent("X11 forwarding enabled");
7509 ssh
->X11_fwd_enabled
= TRUE
;
7511 logevent("X11 forwarding refused");
7517 static void ssh2_maybe_setup_agent(struct ssh_channel
*c
, struct Packet
*pktin
,
7520 struct ssh2_maybe_setup_agent_state
{
7524 struct Packet
*pktout
;
7525 crStateP(ssh2_maybe_setup_agent_state
, ctx
);
7529 if (ssh
->mainchan
&& !ssh
->ncmode
&& conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
7530 logevent("Requesting OpenSSH-style agent forwarding");
7531 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "auth-agent-req@openssh.com",
7532 ssh2_maybe_setup_agent
, s
);
7533 ssh2_pkt_send(ssh
, pktout
);
7535 crWaitUntilV(pktin
);
7538 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7539 logevent("Agent forwarding enabled");
7540 ssh
->agentfwd_enabled
= TRUE
;
7542 logevent("Agent forwarding refused");
7548 static void ssh2_maybe_setup_pty(struct ssh_channel
*c
, struct Packet
*pktin
,
7551 struct ssh2_maybe_setup_pty_state
{
7555 struct Packet
*pktout
;
7556 crStateP(ssh2_maybe_setup_pty_state
, ctx
);
7560 if (ssh
->mainchan
&& !ssh
->ncmode
&& !conf_get_int(ssh
->conf
, CONF_nopty
)) {
7561 /* Unpick the terminal-speed string. */
7562 /* XXX perhaps we should allow no speeds to be sent. */
7563 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
7564 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
7565 /* Build the pty request. */
7566 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "pty-req",
7567 ssh2_maybe_setup_pty
, s
);
7568 ssh2_pkt_addstring(pktout
, conf_get_str(ssh
->conf
, CONF_termtype
));
7569 ssh2_pkt_adduint32(pktout
, ssh
->term_width
);
7570 ssh2_pkt_adduint32(pktout
, ssh
->term_height
);
7571 ssh2_pkt_adduint32(pktout
, 0); /* pixel width */
7572 ssh2_pkt_adduint32(pktout
, 0); /* pixel height */
7573 ssh2_pkt_addstring_start(pktout
);
7574 parse_ttymodes(ssh
, ssh2_send_ttymode
, (void *)pktout
);
7575 ssh2_pkt_addbyte(pktout
, SSH2_TTY_OP_ISPEED
);
7576 ssh2_pkt_adduint32(pktout
, ssh
->ispeed
);
7577 ssh2_pkt_addbyte(pktout
, SSH2_TTY_OP_OSPEED
);
7578 ssh2_pkt_adduint32(pktout
, ssh
->ospeed
);
7579 ssh2_pkt_addstring_data(pktout
, "\0", 1); /* TTY_OP_END */
7580 ssh2_pkt_send(ssh
, pktout
);
7581 ssh
->state
= SSH_STATE_INTERMED
;
7583 crWaitUntilV(pktin
);
7586 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
) {
7587 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7588 ssh
->ospeed
, ssh
->ispeed
);
7589 ssh
->got_pty
= TRUE
;
7591 c_write_str(ssh
, "Server refused to allocate pty\r\n");
7592 ssh
->editing
= ssh
->echoing
= 1;
7596 ssh
->editing
= ssh
->echoing
= 1;
7601 static void ssh2_setup_env(struct ssh_channel
*c
, struct Packet
*pktin
,
7604 struct ssh2_setup_env_state
{
7606 int num_env
, env_left
, env_ok
;
7609 struct Packet
*pktout
;
7610 crStateP(ssh2_setup_env_state
, ctx
);
7615 * Send environment variables.
7617 * Simplest thing here is to send all the requests at once, and
7618 * then wait for a whole bunch of successes or failures.
7621 if (ssh
->mainchan
&& !ssh
->ncmode
) {
7624 for (val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, NULL
, &key
);
7626 val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, key
, &key
)) {
7627 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "env", ssh2_setup_env
, s
);
7628 ssh2_pkt_addstring(pktout
, key
);
7629 ssh2_pkt_addstring(pktout
, val
);
7630 ssh2_pkt_send(ssh
, pktout
);
7635 logeventf(ssh
, "Sent %d environment variables", s
->num_env
);
7640 s
->env_left
= s
->num_env
;
7642 while (s
->env_left
> 0) {
7643 crWaitUntilV(pktin
);
7644 if (!pktin
) goto out
;
7645 if (pktin
->type
== SSH2_MSG_CHANNEL_SUCCESS
)
7650 if (s
->env_ok
== s
->num_env
) {
7651 logevent("All environment variables successfully set");
7652 } else if (s
->env_ok
== 0) {
7653 logevent("All environment variables refused");
7654 c_write_str(ssh
, "Server refused to set environment variables\r\n");
7656 logeventf(ssh
, "%d environment variables refused",
7657 s
->num_env
- s
->env_ok
);
7658 c_write_str(ssh
, "Server refused to set all environment variables\r\n");
7666 * Handle the SSH-2 userauth and connection layers.
7668 static void ssh2_msg_authconn(Ssh ssh
, struct Packet
*pktin
)
7670 do_ssh2_authconn(ssh
, NULL
, 0, pktin
);
7673 static void ssh2_response_authconn(struct ssh_channel
*c
, struct Packet
*pktin
,
7676 do_ssh2_authconn(c
->ssh
, NULL
, 0, pktin
);
7679 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
,
7680 struct Packet
*pktin
)
7682 struct do_ssh2_authconn_state
{
7686 AUTH_TYPE_PUBLICKEY
,
7687 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
7688 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
7690 AUTH_TYPE_GSSAPI
, /* always QUIET */
7691 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
7692 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7694 int done_service_req
;
7695 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
7696 int tried_pubkey_config
, done_agent
;
7701 int kbd_inter_refused
;
7702 int we_are_in
, userauth_success
;
7703 prompts_t
*cur_prompt
;
7708 void *publickey_blob
;
7709 int publickey_bloblen
;
7710 int publickey_encrypted
;
7711 char *publickey_algorithm
;
7712 char *publickey_comment
;
7713 unsigned char agent_request
[5], *agent_response
, *agentp
;
7714 int agent_responselen
;
7715 unsigned char *pkblob_in_agent
;
7717 char *pkblob
, *alg
, *commentp
;
7718 int pklen
, alglen
, commentlen
;
7719 int siglen
, retlen
, len
;
7720 char *q
, *agentreq
, *ret
;
7722 struct Packet
*pktout
;
7725 struct ssh_gss_library
*gsslib
;
7726 Ssh_gss_ctx gss_ctx
;
7727 Ssh_gss_buf gss_buf
;
7728 Ssh_gss_buf gss_rcvtok
, gss_sndtok
;
7729 Ssh_gss_name gss_srv_name
;
7730 Ssh_gss_stat gss_stat
;
7733 crState(do_ssh2_authconn_state
);
7737 /* Register as a handler for all the messages this coroutine handles. */
7738 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_ACCEPT
] = ssh2_msg_authconn
;
7739 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_REQUEST
] = ssh2_msg_authconn
;
7740 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_FAILURE
] = ssh2_msg_authconn
;
7741 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_SUCCESS
] = ssh2_msg_authconn
;
7742 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = ssh2_msg_authconn
;
7743 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_PK_OK
] = ssh2_msg_authconn
;
7744 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_authconn; duplicate case value */
7745 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_authconn; duplicate case value */
7746 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_INFO_RESPONSE
] = ssh2_msg_authconn
;
7747 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] = ssh2_msg_authconn
;
7748 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_SUCCESS
] = ssh2_msg_authconn
;
7749 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_FAILURE
] = ssh2_msg_authconn
;
7750 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] = ssh2_msg_authconn
;
7751 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] = ssh2_msg_authconn
;
7752 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] = ssh2_msg_authconn
;
7753 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] = ssh2_msg_authconn
;
7754 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] = ssh2_msg_authconn
;
7755 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] = ssh2_msg_authconn
;
7756 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_authconn
;
7757 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_authconn
;
7759 s
->done_service_req
= FALSE
;
7760 s
->we_are_in
= s
->userauth_success
= FALSE
;
7762 s
->tried_gssapi
= FALSE
;
7765 if (!conf_get_int(ssh
->conf
, CONF_ssh_no_userauth
)) {
7767 * Request userauth protocol, and await a response to it.
7769 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7770 ssh2_pkt_addstring(s
->pktout
, "ssh-userauth");
7771 ssh2_pkt_send(ssh
, s
->pktout
);
7772 crWaitUntilV(pktin
);
7773 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
)
7774 s
->done_service_req
= TRUE
;
7776 if (!s
->done_service_req
) {
7778 * Request connection protocol directly, without authentication.
7780 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7781 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7782 ssh2_pkt_send(ssh
, s
->pktout
);
7783 crWaitUntilV(pktin
);
7784 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
) {
7785 s
->we_are_in
= TRUE
; /* no auth required */
7787 bombout(("Server refused service request"));
7792 /* Arrange to be able to deal with any BANNERs that come in.
7793 * (We do this now as packets may come in during the next bit.) */
7794 bufchain_init(&ssh
->banner
);
7795 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] =
7796 ssh2_msg_userauth_banner
;
7799 * Misc one-time setup for authentication.
7801 s
->publickey_blob
= NULL
;
7802 if (!s
->we_are_in
) {
7805 * Load the public half of any configured public key file
7808 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
7809 if (!filename_is_null(s
->keyfile
)) {
7811 logeventf(ssh
, "Reading private key file \"%.150s\"",
7812 filename_to_str(s
->keyfile
));
7813 keytype
= key_type(s
->keyfile
);
7814 if (keytype
== SSH_KEYTYPE_SSH2
) {
7817 ssh2_userkey_loadpub(s
->keyfile
,
7818 &s
->publickey_algorithm
,
7819 &s
->publickey_bloblen
,
7820 &s
->publickey_comment
, &error
);
7821 if (s
->publickey_blob
) {
7822 s
->publickey_encrypted
=
7823 ssh2_userkey_encrypted(s
->keyfile
, NULL
);
7826 logeventf(ssh
, "Unable to load private key (%s)",
7828 msgbuf
= dupprintf("Unable to load private key file "
7829 "\"%.150s\" (%s)\r\n",
7830 filename_to_str(s
->keyfile
),
7832 c_write_str(ssh
, msgbuf
);
7837 logeventf(ssh
, "Unable to use this key file (%s)",
7838 key_type_to_str(keytype
));
7839 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
7841 filename_to_str(s
->keyfile
),
7842 key_type_to_str(keytype
));
7843 c_write_str(ssh
, msgbuf
);
7845 s
->publickey_blob
= NULL
;
7850 * Find out about any keys Pageant has (but if there's a
7851 * public key configured, filter out all others).
7854 s
->agent_response
= NULL
;
7855 s
->pkblob_in_agent
= NULL
;
7856 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists()) {
7860 logevent("Pageant is running. Requesting keys.");
7862 /* Request the keys held by the agent. */
7863 PUT_32BIT(s
->agent_request
, 1);
7864 s
->agent_request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
7865 if (!agent_query(s
->agent_request
, 5, &r
, &s
->agent_responselen
,
7866 ssh_agent_callback
, ssh
)) {
7870 bombout(("Unexpected data from server while"
7871 " waiting for agent response"));
7874 } while (pktin
|| inlen
> 0);
7875 r
= ssh
->agent_response
;
7876 s
->agent_responselen
= ssh
->agent_response_len
;
7878 s
->agent_response
= (unsigned char *) r
;
7879 if (s
->agent_response
&& s
->agent_responselen
>= 5 &&
7880 s
->agent_response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
7883 p
= s
->agent_response
+ 5;
7884 s
->nkeys
= GET_32BIT(p
);
7886 logeventf(ssh
, "Pageant has %d SSH-2 keys", s
->nkeys
);
7887 if (s
->publickey_blob
) {
7888 /* See if configured key is in agent. */
7889 for (keyi
= 0; keyi
< s
->nkeys
; keyi
++) {
7890 s
->pklen
= GET_32BIT(p
);
7891 if (s
->pklen
== s
->publickey_bloblen
&&
7892 !memcmp(p
+4, s
->publickey_blob
,
7893 s
->publickey_bloblen
)) {
7894 logeventf(ssh
, "Pageant key #%d matches "
7895 "configured key file", keyi
);
7897 s
->pkblob_in_agent
= p
;
7901 p
+= GET_32BIT(p
) + 4; /* comment */
7903 if (!s
->pkblob_in_agent
) {
7904 logevent("Configured key file not in Pageant");
7909 logevent("Failed to get reply from Pageant");
7916 * We repeat this whole loop, including the username prompt,
7917 * until we manage a successful authentication. If the user
7918 * types the wrong _password_, they can be sent back to the
7919 * beginning to try another username, if this is configured on.
7920 * (If they specify a username in the config, they are never
7921 * asked, even if they do give a wrong password.)
7923 * I think this best serves the needs of
7925 * - the people who have no configuration, no keys, and just
7926 * want to try repeated (username,password) pairs until they
7927 * type both correctly
7929 * - people who have keys and configuration but occasionally
7930 * need to fall back to passwords
7932 * - people with a key held in Pageant, who might not have
7933 * logged in to a particular machine before; so they want to
7934 * type a username, and then _either_ their key will be
7935 * accepted, _or_ they will type a password. If they mistype
7936 * the username they will want to be able to get back and
7939 s
->got_username
= FALSE
;
7940 while (!s
->we_are_in
) {
7944 if (s
->got_username
&& !conf_get_int(ssh
->conf
, CONF_change_username
)) {
7946 * We got a username last time round this loop, and
7947 * with change_username turned off we don't try to get
7950 } else if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
7951 int ret
; /* need not be kept over crReturn */
7952 s
->cur_prompt
= new_prompts(ssh
->frontend
);
7953 s
->cur_prompt
->to_server
= TRUE
;
7954 s
->cur_prompt
->name
= dupstr("SSH login name");
7955 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
7956 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
7959 crWaitUntilV(!pktin
);
7960 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
7965 * get_userpass_input() failed to get a username.
7968 free_prompts(s
->cur_prompt
);
7969 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
7972 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
7973 free_prompts(s
->cur_prompt
);
7976 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
7977 stuff
= dupprintf("Using username \"%s\".\r\n", ssh
->username
);
7978 c_write_str(ssh
, stuff
);
7982 s
->got_username
= TRUE
;
7985 * Send an authentication request using method "none": (a)
7986 * just in case it succeeds, and (b) so that we know what
7987 * authentication methods we can usefully try next.
7989 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
7991 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7992 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7993 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");/* service requested */
7994 ssh2_pkt_addstring(s
->pktout
, "none"); /* method */
7995 ssh2_pkt_send(ssh
, s
->pktout
);
7996 s
->type
= AUTH_TYPE_NONE
;
7998 s
->we_are_in
= FALSE
;
8000 s
->tried_pubkey_config
= FALSE
;
8001 s
->kbd_inter_refused
= FALSE
;
8003 /* Reset agent request state. */
8004 s
->done_agent
= FALSE
;
8005 if (s
->agent_response
) {
8006 if (s
->pkblob_in_agent
) {
8007 s
->agentp
= s
->pkblob_in_agent
;
8009 s
->agentp
= s
->agent_response
+ 5 + 4;
8015 char *methods
= NULL
;
8019 * Wait for the result of the last authentication request.
8022 crWaitUntilV(pktin
);
8024 * Now is a convenient point to spew any banner material
8025 * that we've accumulated. (This should ensure that when
8026 * we exit the auth loop, we haven't any left to deal
8030 int size
= bufchain_size(&ssh
->banner
);
8032 * Don't show the banner if we're operating in
8033 * non-verbose non-interactive mode. (It's probably
8034 * a script, which means nobody will read the
8035 * banner _anyway_, and moreover the printing of
8036 * the banner will screw up processing on the
8037 * output of (say) plink.)
8039 if (size
&& (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
))) {
8040 char *banner
= snewn(size
, char);
8041 bufchain_fetch(&ssh
->banner
, banner
, size
);
8042 c_write_untrusted(ssh
, banner
, size
);
8045 bufchain_clear(&ssh
->banner
);
8047 if (pktin
->type
== SSH2_MSG_USERAUTH_SUCCESS
) {
8048 logevent("Access granted");
8049 s
->we_are_in
= s
->userauth_success
= TRUE
;
8053 if (pktin
->type
!= SSH2_MSG_USERAUTH_FAILURE
&& s
->type
!= AUTH_TYPE_GSSAPI
) {
8054 bombout(("Strange packet received during authentication: "
8055 "type %d", pktin
->type
));
8062 * OK, we're now sitting on a USERAUTH_FAILURE message, so
8063 * we can look at the string in it and know what we can
8064 * helpfully try next.
8066 if (pktin
->type
== SSH2_MSG_USERAUTH_FAILURE
) {
8067 ssh_pkt_getstring(pktin
, &methods
, &methlen
);
8068 if (!ssh2_pkt_getbool(pktin
)) {
8070 * We have received an unequivocal Access
8071 * Denied. This can translate to a variety of
8072 * messages, or no message at all.
8074 * For forms of authentication which are attempted
8075 * implicitly, by which I mean without printing
8076 * anything in the window indicating that we're
8077 * trying them, we should never print 'Access
8080 * If we do print a message saying that we're
8081 * attempting some kind of authentication, it's OK
8082 * to print a followup message saying it failed -
8083 * but the message may sometimes be more specific
8084 * than simply 'Access denied'.
8086 * Additionally, if we'd just tried password
8087 * authentication, we should break out of this
8088 * whole loop so as to go back to the username
8089 * prompt (iff we're configured to allow
8090 * username change attempts).
8092 if (s
->type
== AUTH_TYPE_NONE
) {
8094 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
8095 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
8096 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
8097 c_write_str(ssh
, "Server refused our key\r\n");
8098 logevent("Server refused our key");
8099 } else if (s
->type
== AUTH_TYPE_PUBLICKEY
) {
8100 /* This _shouldn't_ happen except by a
8101 * protocol bug causing client and server to
8102 * disagree on what is a correct signature. */
8103 c_write_str(ssh
, "Server refused public-key signature"
8104 " despite accepting key!\r\n");
8105 logevent("Server refused public-key signature"
8106 " despite accepting key!");
8107 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
8108 /* quiet, so no c_write */
8109 logevent("Server refused keyboard-interactive authentication");
8110 } else if (s
->type
==AUTH_TYPE_GSSAPI
) {
8111 /* always quiet, so no c_write */
8112 /* also, the code down in the GSSAPI block has
8113 * already logged this in the Event Log */
8114 } else if (s
->type
== AUTH_TYPE_KEYBOARD_INTERACTIVE
) {
8115 logevent("Keyboard-interactive authentication failed");
8116 c_write_str(ssh
, "Access denied\r\n");
8118 assert(s
->type
== AUTH_TYPE_PASSWORD
);
8119 logevent("Password authentication failed");
8120 c_write_str(ssh
, "Access denied\r\n");
8122 if (conf_get_int(ssh
->conf
, CONF_change_username
)) {
8123 /* XXX perhaps we should allow
8124 * keyboard-interactive to do this too? */
8125 s
->we_are_in
= FALSE
;
8130 c_write_str(ssh
, "Further authentication required\r\n");
8131 logevent("Further authentication required");
8135 in_commasep_string("publickey", methods
, methlen
);
8137 in_commasep_string("password", methods
, methlen
);
8138 s
->can_keyb_inter
= conf_get_int(ssh
->conf
, CONF_try_ki_auth
) &&
8139 in_commasep_string("keyboard-interactive", methods
, methlen
);
8142 ssh
->gsslibs
= ssh_gss_setup(ssh
->conf
);
8143 s
->can_gssapi
= conf_get_int(ssh
->conf
, CONF_try_gssapi_auth
) &&
8144 in_commasep_string("gssapi-with-mic", methods
, methlen
) &&
8145 ssh
->gsslibs
->nlibraries
> 0;
8149 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
8151 if (s
->can_pubkey
&& !s
->done_agent
&& s
->nkeys
) {
8154 * Attempt public-key authentication using a key from Pageant.
8157 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
8159 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
8161 /* Unpack key from agent response */
8162 s
->pklen
= GET_32BIT(s
->agentp
);
8164 s
->pkblob
= (char *)s
->agentp
;
8165 s
->agentp
+= s
->pklen
;
8166 s
->alglen
= GET_32BIT(s
->pkblob
);
8167 s
->alg
= s
->pkblob
+ 4;
8168 s
->commentlen
= GET_32BIT(s
->agentp
);
8170 s
->commentp
= (char *)s
->agentp
;
8171 s
->agentp
+= s
->commentlen
;
8172 /* s->agentp now points at next key, if any */
8174 /* See if server will accept it */
8175 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8176 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8177 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8178 /* service requested */
8179 ssh2_pkt_addstring(s
->pktout
, "publickey");
8181 ssh2_pkt_addbool(s
->pktout
, FALSE
); /* no signature included */
8182 ssh2_pkt_addstring_start(s
->pktout
);
8183 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
8184 ssh2_pkt_addstring_start(s
->pktout
);
8185 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
8186 ssh2_pkt_send(ssh
, s
->pktout
);
8187 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_QUIET
;
8189 crWaitUntilV(pktin
);
8190 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
8192 /* Offer of key refused. */
8199 if (flags
& FLAG_VERBOSE
) {
8200 c_write_str(ssh
, "Authenticating with "
8202 c_write(ssh
, s
->commentp
, s
->commentlen
);
8203 c_write_str(ssh
, "\" from agent\r\n");
8207 * Server is willing to accept the key.
8208 * Construct a SIGN_REQUEST.
8210 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8211 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8212 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8213 /* service requested */
8214 ssh2_pkt_addstring(s
->pktout
, "publickey");
8216 ssh2_pkt_addbool(s
->pktout
, TRUE
); /* signature included */
8217 ssh2_pkt_addstring_start(s
->pktout
);
8218 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
8219 ssh2_pkt_addstring_start(s
->pktout
);
8220 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
8222 /* Ask agent for signature. */
8223 s
->siglen
= s
->pktout
->length
- 5 + 4 +
8224 ssh
->v2_session_id_len
;
8225 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8227 s
->len
= 1; /* message type */
8228 s
->len
+= 4 + s
->pklen
; /* key blob */
8229 s
->len
+= 4 + s
->siglen
; /* data to sign */
8230 s
->len
+= 4; /* flags */
8231 s
->agentreq
= snewn(4 + s
->len
, char);
8232 PUT_32BIT(s
->agentreq
, s
->len
);
8233 s
->q
= s
->agentreq
+ 4;
8234 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
8235 PUT_32BIT(s
->q
, s
->pklen
);
8237 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
8239 PUT_32BIT(s
->q
, s
->siglen
);
8241 /* Now the data to be signed... */
8242 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8243 PUT_32BIT(s
->q
, ssh
->v2_session_id_len
);
8246 memcpy(s
->q
, ssh
->v2_session_id
,
8247 ssh
->v2_session_id_len
);
8248 s
->q
+= ssh
->v2_session_id_len
;
8249 memcpy(s
->q
, s
->pktout
->data
+ 5,
8250 s
->pktout
->length
- 5);
8251 s
->q
+= s
->pktout
->length
- 5;
8252 /* And finally the (zero) flags word. */
8254 if (!agent_query(s
->agentreq
, s
->len
+ 4,
8256 ssh_agent_callback
, ssh
)) {
8260 bombout(("Unexpected data from server"
8261 " while waiting for agent"
8265 } while (pktin
|| inlen
> 0);
8266 vret
= ssh
->agent_response
;
8267 s
->retlen
= ssh
->agent_response_len
;
8272 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
8273 logevent("Sending Pageant's response");
8274 ssh2_add_sigblob(ssh
, s
->pktout
,
8275 s
->pkblob
, s
->pklen
,
8277 GET_32BIT(s
->ret
+ 5));
8278 ssh2_pkt_send(ssh
, s
->pktout
);
8279 s
->type
= AUTH_TYPE_PUBLICKEY
;
8281 /* FIXME: less drastic response */
8282 bombout(("Pageant failed to answer challenge"));
8288 /* Do we have any keys left to try? */
8289 if (s
->pkblob_in_agent
) {
8290 s
->done_agent
= TRUE
;
8291 s
->tried_pubkey_config
= TRUE
;
8294 if (s
->keyi
>= s
->nkeys
)
8295 s
->done_agent
= TRUE
;
8298 } else if (s
->can_pubkey
&& s
->publickey_blob
&&
8299 !s
->tried_pubkey_config
) {
8301 struct ssh2_userkey
*key
; /* not live over crReturn */
8302 char *passphrase
; /* not live over crReturn */
8304 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
8306 s
->tried_pubkey_config
= TRUE
;
8309 * Try the public key supplied in the configuration.
8311 * First, offer the public blob to see if the server is
8312 * willing to accept it.
8314 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8315 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8316 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8317 /* service requested */
8318 ssh2_pkt_addstring(s
->pktout
, "publickey"); /* method */
8319 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8320 /* no signature included */
8321 ssh2_pkt_addstring(s
->pktout
, s
->publickey_algorithm
);
8322 ssh2_pkt_addstring_start(s
->pktout
);
8323 ssh2_pkt_addstring_data(s
->pktout
,
8324 (char *)s
->publickey_blob
,
8325 s
->publickey_bloblen
);
8326 ssh2_pkt_send(ssh
, s
->pktout
);
8327 logevent("Offered public key");
8329 crWaitUntilV(pktin
);
8330 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
8331 /* Key refused. Give up. */
8332 s
->gotit
= TRUE
; /* reconsider message next loop */
8333 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
8334 continue; /* process this new message */
8336 logevent("Offer of public key accepted");
8339 * Actually attempt a serious authentication using
8342 if (flags
& FLAG_VERBOSE
) {
8343 c_write_str(ssh
, "Authenticating with public key \"");
8344 c_write_str(ssh
, s
->publickey_comment
);
8345 c_write_str(ssh
, "\"\r\n");
8349 const char *error
; /* not live over crReturn */
8350 if (s
->publickey_encrypted
) {
8352 * Get a passphrase from the user.
8354 int ret
; /* need not be kept over crReturn */
8355 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8356 s
->cur_prompt
->to_server
= FALSE
;
8357 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
8358 add_prompt(s
->cur_prompt
,
8359 dupprintf("Passphrase for key \"%.100s\": ",
8360 s
->publickey_comment
),
8362 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8365 crWaitUntilV(!pktin
);
8366 ret
= get_userpass_input(s
->cur_prompt
,
8371 /* Failed to get a passphrase. Terminate. */
8372 free_prompts(s
->cur_prompt
);
8373 ssh_disconnect(ssh
, NULL
,
8374 "Unable to authenticate",
8375 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8380 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8381 free_prompts(s
->cur_prompt
);
8383 passphrase
= NULL
; /* no passphrase needed */
8387 * Try decrypting the key.
8389 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
8390 key
= ssh2_load_userkey(s
->keyfile
, passphrase
, &error
);
8392 /* burn the evidence */
8393 smemclr(passphrase
, strlen(passphrase
));
8396 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
8398 (key
== SSH2_WRONG_PASSPHRASE
)) {
8399 c_write_str(ssh
, "Wrong passphrase\r\n");
8401 /* and loop again */
8403 c_write_str(ssh
, "Unable to load private key (");
8404 c_write_str(ssh
, error
);
8405 c_write_str(ssh
, ")\r\n");
8407 break; /* try something else */
8413 unsigned char *pkblob
, *sigblob
, *sigdata
;
8414 int pkblob_len
, sigblob_len
, sigdata_len
;
8418 * We have loaded the private key and the server
8419 * has announced that it's willing to accept it.
8420 * Hallelujah. Generate a signature and send it.
8422 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8423 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8424 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8425 /* service requested */
8426 ssh2_pkt_addstring(s
->pktout
, "publickey");
8428 ssh2_pkt_addbool(s
->pktout
, TRUE
);
8429 /* signature follows */
8430 ssh2_pkt_addstring(s
->pktout
, key
->alg
->name
);
8431 pkblob
= key
->alg
->public_blob(key
->data
,
8433 ssh2_pkt_addstring_start(s
->pktout
);
8434 ssh2_pkt_addstring_data(s
->pktout
, (char *)pkblob
,
8438 * The data to be signed is:
8442 * followed by everything so far placed in the
8445 sigdata_len
= s
->pktout
->length
- 5 + 4 +
8446 ssh
->v2_session_id_len
;
8447 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8449 sigdata
= snewn(sigdata_len
, unsigned char);
8451 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8452 PUT_32BIT(sigdata
+p
, ssh
->v2_session_id_len
);
8455 memcpy(sigdata
+p
, ssh
->v2_session_id
,
8456 ssh
->v2_session_id_len
);
8457 p
+= ssh
->v2_session_id_len
;
8458 memcpy(sigdata
+p
, s
->pktout
->data
+ 5,
8459 s
->pktout
->length
- 5);
8460 p
+= s
->pktout
->length
- 5;
8461 assert(p
== sigdata_len
);
8462 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
8463 sigdata_len
, &sigblob_len
);
8464 ssh2_add_sigblob(ssh
, s
->pktout
, pkblob
, pkblob_len
,
8465 sigblob
, sigblob_len
);
8470 ssh2_pkt_send(ssh
, s
->pktout
);
8471 logevent("Sent public key signature");
8472 s
->type
= AUTH_TYPE_PUBLICKEY
;
8473 key
->alg
->freekey(key
->data
);
8477 } else if (s
->can_gssapi
&& !s
->tried_gssapi
) {
8479 /* GSSAPI Authentication */
8484 s
->type
= AUTH_TYPE_GSSAPI
;
8485 s
->tried_gssapi
= TRUE
;
8487 ssh
->pkt_actx
= SSH2_PKTCTX_GSSAPI
;
8490 * Pick the highest GSS library on the preference
8496 for (i
= 0; i
< ngsslibs
; i
++) {
8497 int want_id
= conf_get_int_int(ssh
->conf
,
8498 CONF_ssh_gsslist
, i
);
8499 for (j
= 0; j
< ssh
->gsslibs
->nlibraries
; j
++)
8500 if (ssh
->gsslibs
->libraries
[j
].id
== want_id
) {
8501 s
->gsslib
= &ssh
->gsslibs
->libraries
[j
];
8502 goto got_gsslib
; /* double break */
8507 * We always expect to have found something in
8508 * the above loop: we only came here if there
8509 * was at least one viable GSS library, and the
8510 * preference list should always mention
8511 * everything and only change the order.
8516 if (s
->gsslib
->gsslogmsg
)
8517 logevent(s
->gsslib
->gsslogmsg
);
8519 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8520 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8521 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8522 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8523 ssh2_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8524 logevent("Attempting GSSAPI authentication");
8526 /* add mechanism info */
8527 s
->gsslib
->indicate_mech(s
->gsslib
, &s
->gss_buf
);
8529 /* number of GSSAPI mechanisms */
8530 ssh2_pkt_adduint32(s
->pktout
,1);
8532 /* length of OID + 2 */
8533 ssh2_pkt_adduint32(s
->pktout
, s
->gss_buf
.length
+ 2);
8534 ssh2_pkt_addbyte(s
->pktout
, SSH2_GSS_OIDTYPE
);
8537 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) s
->gss_buf
.length
);
8539 ssh_pkt_adddata(s
->pktout
, s
->gss_buf
.value
,
8541 ssh2_pkt_send(ssh
, s
->pktout
);
8542 crWaitUntilV(pktin
);
8543 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_RESPONSE
) {
8544 logevent("GSSAPI authentication request refused");
8548 /* check returned packet ... */
8550 ssh_pkt_getstring(pktin
, &data
, &len
);
8551 s
->gss_rcvtok
.value
= data
;
8552 s
->gss_rcvtok
.length
= len
;
8553 if (s
->gss_rcvtok
.length
!= s
->gss_buf
.length
+ 2 ||
8554 ((char *)s
->gss_rcvtok
.value
)[0] != SSH2_GSS_OIDTYPE
||
8555 ((char *)s
->gss_rcvtok
.value
)[1] != s
->gss_buf
.length
||
8556 memcmp((char *)s
->gss_rcvtok
.value
+ 2,
8557 s
->gss_buf
.value
,s
->gss_buf
.length
) ) {
8558 logevent("GSSAPI authentication - wrong response from server");
8562 /* now start running */
8563 s
->gss_stat
= s
->gsslib
->import_name(s
->gsslib
,
8566 if (s
->gss_stat
!= SSH_GSS_OK
) {
8567 if (s
->gss_stat
== SSH_GSS_BAD_HOST_NAME
)
8568 logevent("GSSAPI import name failed - Bad service name");
8570 logevent("GSSAPI import name failed");
8574 /* fetch TGT into GSS engine */
8575 s
->gss_stat
= s
->gsslib
->acquire_cred(s
->gsslib
, &s
->gss_ctx
);
8577 if (s
->gss_stat
!= SSH_GSS_OK
) {
8578 logevent("GSSAPI authentication failed to get credentials");
8579 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8583 /* initial tokens are empty */
8584 SSH_GSS_CLEAR_BUF(&s
->gss_rcvtok
);
8585 SSH_GSS_CLEAR_BUF(&s
->gss_sndtok
);
8587 /* now enter the loop */
8589 s
->gss_stat
= s
->gsslib
->init_sec_context
8593 conf_get_int(ssh
->conf
, CONF_gssapifwd
),
8597 if (s
->gss_stat
!=SSH_GSS_S_COMPLETE
&&
8598 s
->gss_stat
!=SSH_GSS_S_CONTINUE_NEEDED
) {
8599 logevent("GSSAPI authentication initialisation failed");
8601 if (s
->gsslib
->display_status(s
->gsslib
, s
->gss_ctx
,
8602 &s
->gss_buf
) == SSH_GSS_OK
) {
8603 logevent(s
->gss_buf
.value
);
8604 sfree(s
->gss_buf
.value
);
8609 logevent("GSSAPI authentication initialised");
8611 /* Client and server now exchange tokens until GSSAPI
8612 * no longer says CONTINUE_NEEDED */
8614 if (s
->gss_sndtok
.length
!= 0) {
8615 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN
);
8616 ssh_pkt_addstring_start(s
->pktout
);
8617 ssh_pkt_addstring_data(s
->pktout
,s
->gss_sndtok
.value
,s
->gss_sndtok
.length
);
8618 ssh2_pkt_send(ssh
, s
->pktout
);
8619 s
->gsslib
->free_tok(s
->gsslib
, &s
->gss_sndtok
);
8622 if (s
->gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
) {
8623 crWaitUntilV(pktin
);
8624 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_TOKEN
) {
8625 logevent("GSSAPI authentication - bad server response");
8626 s
->gss_stat
= SSH_GSS_FAILURE
;
8629 ssh_pkt_getstring(pktin
, &data
, &len
);
8630 s
->gss_rcvtok
.value
= data
;
8631 s
->gss_rcvtok
.length
= len
;
8633 } while (s
-> gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
);
8635 if (s
->gss_stat
!= SSH_GSS_OK
) {
8636 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8637 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8640 logevent("GSSAPI authentication loop finished OK");
8642 /* Now send the MIC */
8644 s
->pktout
= ssh2_pkt_init(0);
8645 micoffset
= s
->pktout
->length
;
8646 ssh_pkt_addstring_start(s
->pktout
);
8647 ssh_pkt_addstring_data(s
->pktout
, (char *)ssh
->v2_session_id
, ssh
->v2_session_id_len
);
8648 ssh_pkt_addbyte(s
->pktout
, SSH2_MSG_USERAUTH_REQUEST
);
8649 ssh_pkt_addstring(s
->pktout
, ssh
->username
);
8650 ssh_pkt_addstring(s
->pktout
, "ssh-connection");
8651 ssh_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8653 s
->gss_buf
.value
= (char *)s
->pktout
->data
+ micoffset
;
8654 s
->gss_buf
.length
= s
->pktout
->length
- micoffset
;
8656 s
->gsslib
->get_mic(s
->gsslib
, s
->gss_ctx
, &s
->gss_buf
, &mic
);
8657 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC
);
8658 ssh_pkt_addstring_start(s
->pktout
);
8659 ssh_pkt_addstring_data(s
->pktout
, mic
.value
, mic
.length
);
8660 ssh2_pkt_send(ssh
, s
->pktout
);
8661 s
->gsslib
->free_mic(s
->gsslib
, &mic
);
8665 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8666 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8669 } else if (s
->can_keyb_inter
&& !s
->kbd_inter_refused
) {
8672 * Keyboard-interactive authentication.
8675 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
8677 ssh
->pkt_actx
= SSH2_PKTCTX_KBDINTER
;
8679 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8680 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8681 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8682 /* service requested */
8683 ssh2_pkt_addstring(s
->pktout
, "keyboard-interactive");
8685 ssh2_pkt_addstring(s
->pktout
, ""); /* lang */
8686 ssh2_pkt_addstring(s
->pktout
, ""); /* submethods */
8687 ssh2_pkt_send(ssh
, s
->pktout
);
8689 logevent("Attempting keyboard-interactive authentication");
8691 crWaitUntilV(pktin
);
8692 if (pktin
->type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8693 /* Server is not willing to do keyboard-interactive
8694 * at all (or, bizarrely but legally, accepts the
8695 * user without actually issuing any prompts).
8696 * Give up on it entirely. */
8698 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
8699 s
->kbd_inter_refused
= TRUE
; /* don't try it again */
8704 * Loop while the server continues to send INFO_REQUESTs.
8706 while (pktin
->type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8708 char *name
, *inst
, *lang
;
8709 int name_len
, inst_len
, lang_len
;
8713 * We've got a fresh USERAUTH_INFO_REQUEST.
8714 * Get the preamble and start building a prompt.
8716 ssh_pkt_getstring(pktin
, &name
, &name_len
);
8717 ssh_pkt_getstring(pktin
, &inst
, &inst_len
);
8718 ssh_pkt_getstring(pktin
, &lang
, &lang_len
);
8719 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8720 s
->cur_prompt
->to_server
= TRUE
;
8723 * Get any prompt(s) from the packet.
8725 s
->num_prompts
= ssh_pkt_getuint32(pktin
);
8726 for (i
= 0; i
< s
->num_prompts
; i
++) {
8730 static char noprompt
[] =
8731 "<server failed to send prompt>: ";
8733 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8734 echo
= ssh2_pkt_getbool(pktin
);
8737 prompt_len
= lenof(noprompt
)-1;
8739 add_prompt(s
->cur_prompt
,
8740 dupprintf("%.*s", prompt_len
, prompt
),
8745 /* FIXME: better prefix to distinguish from
8747 s
->cur_prompt
->name
=
8748 dupprintf("SSH server: %.*s", name_len
, name
);
8749 s
->cur_prompt
->name_reqd
= TRUE
;
8751 s
->cur_prompt
->name
=
8752 dupstr("SSH server authentication");
8753 s
->cur_prompt
->name_reqd
= FALSE
;
8755 /* We add a prefix to try to make it clear that a prompt
8756 * has come from the server.
8757 * FIXME: ugly to print "Using..." in prompt _every_
8758 * time round. Can this be done more subtly? */
8759 /* Special case: for reasons best known to themselves,
8760 * some servers send k-i requests with no prompts and
8761 * nothing to display. Keep quiet in this case. */
8762 if (s
->num_prompts
|| name_len
|| inst_len
) {
8763 s
->cur_prompt
->instruction
=
8764 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8765 inst_len ?
"\n" : "", inst_len
, inst
);
8766 s
->cur_prompt
->instr_reqd
= TRUE
;
8768 s
->cur_prompt
->instr_reqd
= FALSE
;
8772 * Display any instructions, and get the user's
8776 int ret
; /* not live over crReturn */
8777 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8780 crWaitUntilV(!pktin
);
8781 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8786 * Failed to get responses. Terminate.
8788 free_prompts(s
->cur_prompt
);
8789 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8790 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8797 * Send the response(s) to the server.
8799 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
8800 ssh2_pkt_adduint32(s
->pktout
, s
->num_prompts
);
8801 for (i
=0; i
< s
->num_prompts
; i
++) {
8802 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8803 ssh2_pkt_addstring(s
->pktout
,
8804 s
->cur_prompt
->prompts
[i
]->result
);
8805 end_log_omission(ssh
, s
->pktout
);
8807 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8810 * Free the prompts structure from this iteration.
8811 * If there's another, a new one will be allocated
8812 * when we return to the top of this while loop.
8814 free_prompts(s
->cur_prompt
);
8817 * Get the next packet in case it's another
8820 crWaitUntilV(pktin
);
8825 * We should have SUCCESS or FAILURE now.
8829 } else if (s
->can_passwd
) {
8832 * Plain old password authentication.
8834 int ret
; /* not live over crReturn */
8835 int changereq_first_time
; /* not live over crReturn */
8837 ssh
->pkt_actx
= SSH2_PKTCTX_PASSWORD
;
8839 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8840 s
->cur_prompt
->to_server
= TRUE
;
8841 s
->cur_prompt
->name
= dupstr("SSH password");
8842 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
8847 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8850 crWaitUntilV(!pktin
);
8851 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8856 * Failed to get responses. Terminate.
8858 free_prompts(s
->cur_prompt
);
8859 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8860 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8865 * Squirrel away the password. (We may need it later if
8866 * asked to change it.)
8868 s
->password
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
8869 free_prompts(s
->cur_prompt
);
8872 * Send the password packet.
8874 * We pad out the password packet to 256 bytes to make
8875 * it harder for an attacker to find the length of the
8878 * Anyone using a password longer than 256 bytes
8879 * probably doesn't have much to worry about from
8880 * people who find out how long their password is!
8882 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8883 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8884 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8885 /* service requested */
8886 ssh2_pkt_addstring(s
->pktout
, "password");
8887 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8888 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8889 ssh2_pkt_addstring(s
->pktout
, s
->password
);
8890 end_log_omission(ssh
, s
->pktout
);
8891 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8892 logevent("Sent password");
8893 s
->type
= AUTH_TYPE_PASSWORD
;
8896 * Wait for next packet, in case it's a password change
8899 crWaitUntilV(pktin
);
8900 changereq_first_time
= TRUE
;
8902 while (pktin
->type
== SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
) {
8905 * We're being asked for a new password
8906 * (perhaps not for the first time).
8907 * Loop until the server accepts it.
8910 int got_new
= FALSE
; /* not live over crReturn */
8911 char *prompt
; /* not live over crReturn */
8912 int prompt_len
; /* not live over crReturn */
8916 if (changereq_first_time
)
8917 msg
= "Server requested password change";
8919 msg
= "Server rejected new password";
8921 c_write_str(ssh
, msg
);
8922 c_write_str(ssh
, "\r\n");
8925 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8927 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8928 s
->cur_prompt
->to_server
= TRUE
;
8929 s
->cur_prompt
->name
= dupstr("New SSH password");
8930 s
->cur_prompt
->instruction
=
8931 dupprintf("%.*s", prompt_len
, prompt
);
8932 s
->cur_prompt
->instr_reqd
= TRUE
;
8934 * There's no explicit requirement in the protocol
8935 * for the "old" passwords in the original and
8936 * password-change messages to be the same, and
8937 * apparently some Cisco kit supports password change
8938 * by the user entering a blank password originally
8939 * and the real password subsequently, so,
8940 * reluctantly, we prompt for the old password again.
8942 * (On the other hand, some servers don't even bother
8943 * to check this field.)
8945 add_prompt(s
->cur_prompt
,
8946 dupstr("Current password (blank for previously entered password): "),
8948 add_prompt(s
->cur_prompt
, dupstr("Enter new password: "),
8950 add_prompt(s
->cur_prompt
, dupstr("Confirm new password: "),
8954 * Loop until the user manages to enter the same
8959 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8962 crWaitUntilV(!pktin
);
8963 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8968 * Failed to get responses. Terminate.
8970 /* burn the evidence */
8971 free_prompts(s
->cur_prompt
);
8972 smemclr(s
->password
, strlen(s
->password
));
8974 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8975 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8981 * If the user specified a new original password
8982 * (IYSWIM), overwrite any previously specified
8984 * (A side effect is that the user doesn't have to
8985 * re-enter it if they louse up the new password.)
8987 if (s
->cur_prompt
->prompts
[0]->result
[0]) {
8988 smemclr(s
->password
, strlen(s
->password
));
8989 /* burn the evidence */
8992 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8996 * Check the two new passwords match.
8998 got_new
= (strcmp(s
->cur_prompt
->prompts
[1]->result
,
8999 s
->cur_prompt
->prompts
[2]->result
)
9002 /* They don't. Silly user. */
9003 c_write_str(ssh
, "Passwords do not match\r\n");
9008 * Send the new password (along with the old one).
9009 * (see above for padding rationale)
9011 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
9012 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
9013 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
9014 /* service requested */
9015 ssh2_pkt_addstring(s
->pktout
, "password");
9016 ssh2_pkt_addbool(s
->pktout
, TRUE
);
9017 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
9018 ssh2_pkt_addstring(s
->pktout
, s
->password
);
9019 ssh2_pkt_addstring(s
->pktout
,
9020 s
->cur_prompt
->prompts
[1]->result
);
9021 free_prompts(s
->cur_prompt
);
9022 end_log_omission(ssh
, s
->pktout
);
9023 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
9024 logevent("Sent new password");
9027 * Now see what the server has to say about it.
9028 * (If it's CHANGEREQ again, it's not happy with the
9031 crWaitUntilV(pktin
);
9032 changereq_first_time
= FALSE
;
9037 * We need to reexamine the current pktin at the top
9038 * of the loop. Either:
9039 * - we weren't asked to change password at all, in
9040 * which case it's a SUCCESS or FAILURE with the
9042 * - we sent a new password, and the server was
9043 * either OK with it (SUCCESS or FAILURE w/partial
9044 * success) or unhappy with the _old_ password
9045 * (FAILURE w/o partial success)
9046 * In any of these cases, we go back to the top of
9047 * the loop and start again.
9052 * We don't need the old password any more, in any
9053 * case. Burn the evidence.
9055 smemclr(s
->password
, strlen(s
->password
));
9059 char *str
= dupprintf("No supported authentication methods available"
9060 " (server sent: %.*s)",
9063 ssh_disconnect(ssh
, str
,
9064 "No supported authentication methods available",
9065 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE
,
9075 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = NULL
;
9077 /* Clear up various bits and pieces from authentication. */
9078 if (s
->publickey_blob
) {
9079 sfree(s
->publickey_blob
);
9080 sfree(s
->publickey_comment
);
9082 if (s
->agent_response
)
9083 sfree(s
->agent_response
);
9085 if (s
->userauth_success
) {
9087 * We've just received USERAUTH_SUCCESS, and we haven't sent any
9088 * packets since. Signal the transport layer to consider enacting
9089 * delayed compression.
9091 * (Relying on we_are_in is not sufficient, as
9092 * draft-miller-secsh-compression-delayed is quite clear that it
9093 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
9094 * become set for other reasons.)
9096 do_ssh2_transport(ssh
, "enabling delayed compression", -2, NULL
);
9100 * Now the connection protocol has started, one way or another.
9103 ssh
->channels
= newtree234(ssh_channelcmp
);
9106 * Set up handlers for some connection protocol messages, so we
9107 * don't have to handle them repeatedly in this coroutine.
9109 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] =
9110 ssh2_msg_channel_window_adjust
;
9111 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] =
9112 ssh2_msg_global_request
;
9115 * Create the main session channel.
9117 if (conf_get_int(ssh
->conf
, CONF_ssh_no_shell
)) {
9118 ssh
->mainchan
= NULL
;
9119 } else if (*conf_get_str(ssh
->conf
, CONF_ssh_nc_host
)) {
9121 * Just start a direct-tcpip channel and use it as the main
9124 ssh
->mainchan
= snew(struct ssh_channel
);
9125 ssh
->mainchan
->ssh
= ssh
;
9126 ssh2_channel_init(ssh
->mainchan
);
9128 "Opening direct-tcpip channel to %s:%d in place of session",
9129 conf_get_str(ssh
->conf
, CONF_ssh_nc_host
),
9130 conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
9131 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
9132 ssh2_pkt_addstring(s
->pktout
, "direct-tcpip");
9133 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
9134 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
9135 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
9136 ssh2_pkt_addstring(s
->pktout
, conf_get_str(ssh
->conf
, CONF_ssh_nc_host
));
9137 ssh2_pkt_adduint32(s
->pktout
, conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
9139 * There's nothing meaningful to put in the originator
9140 * fields, but some servers insist on syntactically correct
9143 ssh2_pkt_addstring(s
->pktout
, "0.0.0.0");
9144 ssh2_pkt_adduint32(s
->pktout
, 0);
9145 ssh2_pkt_send(ssh
, s
->pktout
);
9147 crWaitUntilV(pktin
);
9148 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
9149 bombout(("Server refused to open a direct-tcpip channel"));
9151 /* FIXME: error data comes back in FAILURE packet */
9153 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
9154 bombout(("Server's channel confirmation cited wrong channel"));
9157 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
9158 ssh
->mainchan
->halfopen
= FALSE
;
9159 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
9160 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
9161 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
9162 add234(ssh
->channels
, ssh
->mainchan
);
9163 update_specials_menu(ssh
->frontend
);
9164 logevent("Opened direct-tcpip channel");
9167 ssh
->mainchan
= snew(struct ssh_channel
);
9168 ssh
->mainchan
->ssh
= ssh
;
9169 ssh2_channel_init(ssh
->mainchan
);
9170 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
9171 ssh2_pkt_addstring(s
->pktout
, "session");
9172 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
9173 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
9174 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
9175 ssh2_pkt_send(ssh
, s
->pktout
);
9176 crWaitUntilV(pktin
);
9177 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
9178 bombout(("Server refused to open a session"));
9180 /* FIXME: error data comes back in FAILURE packet */
9182 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
9183 bombout(("Server's channel confirmation cited wrong channel"));
9186 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
9187 ssh
->mainchan
->halfopen
= FALSE
;
9188 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
9189 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
9190 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
9191 add234(ssh
->channels
, ssh
->mainchan
);
9192 update_specials_menu(ssh
->frontend
);
9193 logevent("Opened channel for session");
9194 ssh
->ncmode
= FALSE
;
9198 * Now we have a channel, make dispatch table entries for
9199 * general channel-based messages.
9201 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] =
9202 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] =
9203 ssh2_msg_channel_data
;
9204 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_channel_eof
;
9205 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_channel_close
;
9206 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] =
9207 ssh2_msg_channel_open_confirmation
;
9208 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] =
9209 ssh2_msg_channel_open_failure
;
9210 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] =
9211 ssh2_msg_channel_request
;
9212 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] =
9213 ssh2_msg_channel_open
;
9214 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_channel_response
;
9215 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_channel_response
;
9218 if (ssh
->mainchan
&& conf_get_int(ssh
->conf
, CONF_ssh_simple
)) {
9220 * This message indicates to the server that we promise
9221 * not to try to run any other channel in parallel with
9222 * this one, so it's safe for it to advertise a very large
9223 * window and leave the flow control to TCP.
9225 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
,
9226 "simple@putty.projects.tartarus.org",
9228 ssh2_pkt_send(ssh
, s
->pktout
);
9232 * Enable port forwardings.
9234 ssh_setup_portfwd(ssh
, ssh
->conf
);
9237 * Send the CHANNEL_REQUESTS for the main channel. Each one is
9238 * handled by its own little asynchronous co-routine.
9242 * Potentially enable X11 forwarding.
9244 ssh2_maybe_setup_x11(ssh
->mainchan
, NULL
, NULL
);
9247 * Potentially enable agent forwarding.
9249 ssh2_maybe_setup_agent(ssh
->mainchan
, NULL
, NULL
);
9252 * Now allocate a pty for the session.
9254 ssh2_maybe_setup_pty(ssh
->mainchan
, NULL
, NULL
);
9257 * Send environment variables.
9259 ssh2_setup_env(ssh
->mainchan
, NULL
, NULL
);
9262 * Start a shell or a remote command. We may have to attempt
9263 * this twice if the config data has provided a second choice
9266 if (ssh
->mainchan
&& !ssh
->ncmode
) while (1) {
9270 if (ssh
->fallback_cmd
) {
9271 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys2
);
9272 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
9274 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys
);
9275 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
9279 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "subsystem",
9280 ssh2_response_authconn
, NULL
);
9281 ssh2_pkt_addstring(s
->pktout
, cmd
);
9283 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "exec",
9284 ssh2_response_authconn
, NULL
);
9285 ssh2_pkt_addstring(s
->pktout
, cmd
);
9287 s
->pktout
= ssh2_chanreq_init(ssh
->mainchan
, "shell",
9288 ssh2_response_authconn
, NULL
);
9290 ssh2_pkt_send(ssh
, s
->pktout
);
9292 crWaitUntilV(pktin
);
9294 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9295 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9296 bombout(("Unexpected response to shell/command request:"
9297 " packet type %d", pktin
->type
));
9301 * We failed to start the command. If this is the
9302 * fallback command, we really are finished; if it's
9303 * not, and if the fallback command exists, try falling
9304 * back to it before complaining.
9306 if (!ssh
->fallback_cmd
&&
9307 *conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
9308 logevent("Primary command failed; attempting fallback");
9309 ssh
->fallback_cmd
= TRUE
;
9312 bombout(("Server refused to start a shell/command"));
9315 logevent("Started a shell/command");
9320 ssh
->state
= SSH_STATE_SESSION
;
9321 if (ssh
->size_needed
)
9322 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
9323 if (ssh
->eof_needed
)
9324 ssh_special(ssh
, TS_EOF
);
9327 * All the initial channel requests are done, so install the default
9330 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_channel_response
;
9331 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_channel_response
;
9337 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
9342 s
->try_send
= FALSE
;
9346 * _All_ the connection-layer packets we expect to
9347 * receive are now handled by the dispatch table.
9348 * Anything that reaches here must be bogus.
9351 bombout(("Strange packet received: type %d", pktin
->type
));
9353 } else if (ssh
->mainchan
) {
9355 * We have spare data. Add it to the channel buffer.
9357 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
9362 struct ssh_channel
*c
;
9364 * Try to send data on all channels if we can.
9366 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++)
9367 ssh2_try_send_and_unthrottle(ssh
, c
);
9375 * Handlers for SSH-2 messages that might arrive at any moment.
9377 static void ssh2_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
9379 /* log reason code in disconnect message */
9383 reason
= ssh_pkt_getuint32(pktin
);
9384 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9386 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
9387 buf
= dupprintf("Received disconnect message (%s)",
9388 ssh2_disconnect_reasons
[reason
]);
9390 buf
= dupprintf("Received disconnect message (unknown"
9391 " type %d)", reason
);
9395 buf
= dupprintf("Disconnection message text: %.*s",
9398 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9400 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
9401 ssh2_disconnect_reasons
[reason
] : "unknown",
9406 static void ssh2_msg_debug(Ssh ssh
, struct Packet
*pktin
)
9408 /* log the debug message */
9412 /* XXX maybe we should actually take notice of the return value */
9413 ssh2_pkt_getbool(pktin
);
9414 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9416 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
9419 static void ssh2_msg_transport(Ssh ssh
, struct Packet
*pktin
)
9421 do_ssh2_transport(ssh
, NULL
, 0, pktin
);
9425 * Called if we receive a packet that isn't allowed by the protocol.
9426 * This only applies to packets whose meaning PuTTY understands.
9427 * Entirely unknown packets are handled below.
9429 static void ssh2_msg_unexpected(Ssh ssh
, struct Packet
*pktin
)
9431 char *buf
= dupprintf("Server protocol violation: unexpected %s packet",
9432 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
9434 ssh_disconnect(ssh
, NULL
, buf
, SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
9438 static void ssh2_msg_something_unimplemented(Ssh ssh
, struct Packet
*pktin
)
9440 struct Packet
*pktout
;
9441 pktout
= ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
9442 ssh2_pkt_adduint32(pktout
, pktin
->sequence
);
9444 * UNIMPLEMENTED messages MUST appear in the same order as the
9445 * messages they respond to. Hence, never queue them.
9447 ssh2_pkt_send_noqueue(ssh
, pktout
);
9451 * Handle the top-level SSH-2 protocol.
9453 static void ssh2_protocol_setup(Ssh ssh
)
9458 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9460 for (i
= 0; i
< 256; i
++)
9461 ssh
->packet_dispatch
[i
] = ssh2_msg_something_unimplemented
;
9464 * Initially, we only accept transport messages (and a few generic
9465 * ones). do_ssh2_authconn will add more when it starts.
9466 * Messages that are understood but not currently acceptable go to
9467 * ssh2_msg_unexpected.
9469 ssh
->packet_dispatch
[SSH2_MSG_UNIMPLEMENTED
] = ssh2_msg_unexpected
;
9470 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_REQUEST
] = ssh2_msg_unexpected
;
9471 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_ACCEPT
] = ssh2_msg_unexpected
;
9472 ssh
->packet_dispatch
[SSH2_MSG_KEXINIT
] = ssh2_msg_transport
;
9473 ssh
->packet_dispatch
[SSH2_MSG_NEWKEYS
] = ssh2_msg_transport
;
9474 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_INIT
] = ssh2_msg_transport
;
9475 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_REPLY
] = ssh2_msg_transport
;
9476 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = ssh2_msg_transport; duplicate case value */
9477 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = ssh2_msg_transport; duplicate case value */
9478 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_INIT
] = ssh2_msg_transport
;
9479 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_REPLY
] = ssh2_msg_transport
;
9480 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_REQUEST
] = ssh2_msg_unexpected
;
9481 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_FAILURE
] = ssh2_msg_unexpected
;
9482 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_SUCCESS
] = ssh2_msg_unexpected
;
9483 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = ssh2_msg_unexpected
;
9484 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_PK_OK
] = ssh2_msg_unexpected
;
9485 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = ssh2_msg_unexpected; duplicate case value */
9486 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = ssh2_msg_unexpected; duplicate case value */
9487 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_INFO_RESPONSE
] = ssh2_msg_unexpected
;
9488 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] = ssh2_msg_unexpected
;
9489 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_SUCCESS
] = ssh2_msg_unexpected
;
9490 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_FAILURE
] = ssh2_msg_unexpected
;
9491 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] = ssh2_msg_unexpected
;
9492 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] = ssh2_msg_unexpected
;
9493 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] = ssh2_msg_unexpected
;
9494 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] = ssh2_msg_unexpected
;
9495 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] = ssh2_msg_unexpected
;
9496 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] = ssh2_msg_unexpected
;
9497 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_unexpected
;
9498 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_unexpected
;
9499 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] = ssh2_msg_unexpected
;
9500 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_unexpected
;
9501 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_unexpected
;
9504 * These messages have a special handler from the start.
9506 ssh
->packet_dispatch
[SSH2_MSG_DISCONNECT
] = ssh2_msg_disconnect
;
9507 ssh
->packet_dispatch
[SSH2_MSG_IGNORE
] = ssh_msg_ignore
; /* shared with SSH-1 */
9508 ssh
->packet_dispatch
[SSH2_MSG_DEBUG
] = ssh2_msg_debug
;
9511 static void ssh2_timer(void *ctx
, long now
)
9515 if (ssh
->state
== SSH_STATE_CLOSED
)
9518 if (!ssh
->kex_in_progress
&& conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0 &&
9519 now
- ssh
->next_rekey
>= 0) {
9520 do_ssh2_transport(ssh
, "timeout", -1, NULL
);
9524 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
9525 struct Packet
*pktin
)
9527 unsigned char *in
= (unsigned char *)vin
;
9528 if (ssh
->state
== SSH_STATE_CLOSED
)
9532 ssh
->incoming_data_size
+= pktin
->encrypted_len
;
9533 if (!ssh
->kex_in_progress
&&
9534 ssh
->max_data_size
!= 0 &&
9535 ssh
->incoming_data_size
> ssh
->max_data_size
)
9536 do_ssh2_transport(ssh
, "too much data received", -1, NULL
);
9540 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
9541 else if (!ssh
->protocol_initial_phase_done
)
9542 do_ssh2_transport(ssh
, in
, inlen
, pktin
);
9544 do_ssh2_authconn(ssh
, in
, inlen
, pktin
);
9547 static void ssh_cache_conf_values(Ssh ssh
)
9549 ssh
->logomitdata
= conf_get_int(ssh
->conf
, CONF_logomitdata
);
9553 * Called to set up the connection.
9555 * Returns an error message, or NULL on success.
9557 static const char *ssh_init(void *frontend_handle
, void **backend_handle
,
9558 Conf
*conf
, char *host
, int port
, char **realhost
,
9559 int nodelay
, int keepalive
)
9564 ssh
= snew(struct ssh_tag
);
9565 ssh
->conf
= conf_copy(conf
);
9566 ssh_cache_conf_values(ssh
);
9567 ssh
->version
= 0; /* when not ready yet */
9570 ssh
->v1_cipher_ctx
= NULL
;
9571 ssh
->crcda_ctx
= NULL
;
9572 ssh
->cscipher
= NULL
;
9573 ssh
->cs_cipher_ctx
= NULL
;
9574 ssh
->sccipher
= NULL
;
9575 ssh
->sc_cipher_ctx
= NULL
;
9577 ssh
->cs_mac_ctx
= NULL
;
9579 ssh
->sc_mac_ctx
= NULL
;
9581 ssh
->cs_comp_ctx
= NULL
;
9583 ssh
->sc_comp_ctx
= NULL
;
9585 ssh
->kex_ctx
= NULL
;
9586 ssh
->hostkey
= NULL
;
9588 ssh
->close_expected
= FALSE
;
9589 ssh
->clean_exit
= FALSE
;
9590 ssh
->state
= SSH_STATE_PREPACKET
;
9591 ssh
->size_needed
= FALSE
;
9592 ssh
->eof_needed
= FALSE
;
9595 ssh
->deferred_send_data
= NULL
;
9596 ssh
->deferred_len
= 0;
9597 ssh
->deferred_size
= 0;
9598 ssh
->fallback_cmd
= 0;
9599 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
9600 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
9601 ssh
->x11disp
= NULL
;
9602 ssh
->v1_compressing
= FALSE
;
9603 ssh
->v2_outgoing_sequence
= 0;
9604 ssh
->ssh1_rdpkt_crstate
= 0;
9605 ssh
->ssh2_rdpkt_crstate
= 0;
9606 ssh
->ssh_gotdata_crstate
= 0;
9607 ssh
->do_ssh1_connection_crstate
= 0;
9608 ssh
->do_ssh_init_state
= NULL
;
9609 ssh
->do_ssh1_login_state
= NULL
;
9610 ssh
->do_ssh2_transport_state
= NULL
;
9611 ssh
->do_ssh2_authconn_state
= NULL
;
9614 ssh
->mainchan
= NULL
;
9615 ssh
->throttled_all
= 0;
9616 ssh
->v1_stdout_throttling
= 0;
9618 ssh
->queuelen
= ssh
->queuesize
= 0;
9619 ssh
->queueing
= FALSE
;
9620 ssh
->qhead
= ssh
->qtail
= NULL
;
9621 ssh
->deferred_rekey_reason
= NULL
;
9622 bufchain_init(&ssh
->queued_incoming_data
);
9623 ssh
->frozen
= FALSE
;
9624 ssh
->username
= NULL
;
9625 ssh
->sent_console_eof
= FALSE
;
9626 ssh
->got_pty
= FALSE
;
9628 *backend_handle
= ssh
;
9631 if (crypto_startup() == 0)
9632 return "Microsoft high encryption pack not installed!";
9635 ssh
->frontend
= frontend_handle
;
9636 ssh
->term_width
= conf_get_int(ssh
->conf
, CONF_width
);
9637 ssh
->term_height
= conf_get_int(ssh
->conf
, CONF_height
);
9639 ssh
->channels
= NULL
;
9640 ssh
->rportfwds
= NULL
;
9641 ssh
->portfwds
= NULL
;
9646 ssh
->conn_throttle_count
= 0;
9647 ssh
->overall_bufsize
= 0;
9648 ssh
->fallback_cmd
= 0;
9650 ssh
->protocol
= NULL
;
9652 ssh
->protocol_initial_phase_done
= FALSE
;
9656 ssh
->incoming_data_size
= ssh
->outgoing_data_size
=
9657 ssh
->deferred_data_size
= 0L;
9658 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9659 CONF_ssh_rekey_data
));
9660 ssh
->kex_in_progress
= FALSE
;
9663 ssh
->gsslibs
= NULL
;
9666 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
, keepalive
);
9675 static void ssh_free(void *handle
)
9677 Ssh ssh
= (Ssh
) handle
;
9678 struct ssh_channel
*c
;
9679 struct ssh_rportfwd
*pf
;
9681 if (ssh
->v1_cipher_ctx
)
9682 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
9683 if (ssh
->cs_cipher_ctx
)
9684 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
9685 if (ssh
->sc_cipher_ctx
)
9686 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
9687 if (ssh
->cs_mac_ctx
)
9688 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
9689 if (ssh
->sc_mac_ctx
)
9690 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
9691 if (ssh
->cs_comp_ctx
) {
9693 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
9695 zlib_compress_cleanup(ssh
->cs_comp_ctx
);
9697 if (ssh
->sc_comp_ctx
) {
9699 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
9701 zlib_decompress_cleanup(ssh
->sc_comp_ctx
);
9704 dh_cleanup(ssh
->kex_ctx
);
9705 sfree(ssh
->savedhost
);
9707 while (ssh
->queuelen
-- > 0)
9708 ssh_free_packet(ssh
->queue
[ssh
->queuelen
]);
9711 while (ssh
->qhead
) {
9712 struct queued_handler
*qh
= ssh
->qhead
;
9713 ssh
->qhead
= qh
->next
;
9716 ssh
->qhead
= ssh
->qtail
= NULL
;
9718 if (ssh
->channels
) {
9719 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
9722 if (c
->u
.x11
.s
!= NULL
)
9723 x11_close(c
->u
.x11
.s
);
9726 case CHAN_SOCKDATA_DORMANT
:
9727 if (c
->u
.pfd
.s
!= NULL
)
9728 pfd_close(c
->u
.pfd
.s
);
9731 if (ssh
->version
== 2) {
9732 struct outstanding_channel_request
*ocr
, *nocr
;
9733 ocr
= c
->v
.v2
.chanreq_head
;
9735 ocr
->handler(c
, NULL
, ocr
->ctx
);
9740 bufchain_clear(&c
->v
.v2
.outbuffer
);
9744 freetree234(ssh
->channels
);
9745 ssh
->channels
= NULL
;
9748 if (ssh
->rportfwds
) {
9749 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
9751 freetree234(ssh
->rportfwds
);
9752 ssh
->rportfwds
= NULL
;
9754 sfree(ssh
->deferred_send_data
);
9756 x11_free_display(ssh
->x11disp
);
9757 sfree(ssh
->do_ssh_init_state
);
9758 sfree(ssh
->do_ssh1_login_state
);
9759 sfree(ssh
->do_ssh2_transport_state
);
9760 sfree(ssh
->do_ssh2_authconn_state
);
9763 sfree(ssh
->fullhostname
);
9764 if (ssh
->crcda_ctx
) {
9765 crcda_free_context(ssh
->crcda_ctx
);
9766 ssh
->crcda_ctx
= NULL
;
9769 ssh_do_close(ssh
, TRUE
);
9770 expire_timer_context(ssh
);
9772 pinger_free(ssh
->pinger
);
9773 bufchain_clear(&ssh
->queued_incoming_data
);
9774 sfree(ssh
->username
);
9775 conf_free(ssh
->conf
);
9778 ssh_gss_cleanup(ssh
->gsslibs
);
9786 * Reconfigure the SSH backend.
9788 static void ssh_reconfig(void *handle
, Conf
*conf
)
9790 Ssh ssh
= (Ssh
) handle
;
9791 char *rekeying
= NULL
, rekey_mandatory
= FALSE
;
9792 unsigned long old_max_data_size
;
9795 pinger_reconfig(ssh
->pinger
, ssh
->conf
, conf
);
9797 ssh_setup_portfwd(ssh
, conf
);
9799 rekey_time
= conf_get_int(conf
, CONF_ssh_rekey_time
);
9800 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != rekey_time
&&
9802 long new_next
= ssh
->last_rekey
+ rekey_time
*60*TICKSPERSEC
;
9803 long now
= GETTICKCOUNT();
9805 if (new_next
- now
< 0) {
9806 rekeying
= "timeout shortened";
9808 ssh
->next_rekey
= schedule_timer(new_next
- now
, ssh2_timer
, ssh
);
9812 old_max_data_size
= ssh
->max_data_size
;
9813 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9814 CONF_ssh_rekey_data
));
9815 if (old_max_data_size
!= ssh
->max_data_size
&&
9816 ssh
->max_data_size
!= 0) {
9817 if (ssh
->outgoing_data_size
> ssh
->max_data_size
||
9818 ssh
->incoming_data_size
> ssh
->max_data_size
)
9819 rekeying
= "data limit lowered";
9822 if (conf_get_int(ssh
->conf
, CONF_compression
) !=
9823 conf_get_int(conf
, CONF_compression
)) {
9824 rekeying
= "compression setting changed";
9825 rekey_mandatory
= TRUE
;
9828 for (i
= 0; i
< CIPHER_MAX
; i
++)
9829 if (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
) !=
9830 conf_get_int_int(conf
, CONF_ssh_cipherlist
, i
)) {
9831 rekeying
= "cipher settings changed";
9832 rekey_mandatory
= TRUE
;
9834 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
) !=
9835 conf_get_int(conf
, CONF_ssh2_des_cbc
)) {
9836 rekeying
= "cipher settings changed";
9837 rekey_mandatory
= TRUE
;
9840 conf_free(ssh
->conf
);
9841 ssh
->conf
= conf_copy(conf
);
9842 ssh_cache_conf_values(ssh
);
9845 if (!ssh
->kex_in_progress
) {
9846 do_ssh2_transport(ssh
, rekeying
, -1, NULL
);
9847 } else if (rekey_mandatory
) {
9848 ssh
->deferred_rekey_reason
= rekeying
;
9854 * Called to send data down the SSH connection.
9856 static int ssh_send(void *handle
, char *buf
, int len
)
9858 Ssh ssh
= (Ssh
) handle
;
9860 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9863 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
9865 return ssh_sendbuffer(ssh
);
9869 * Called to query the current amount of buffered stdin data.
9871 static int ssh_sendbuffer(void *handle
)
9873 Ssh ssh
= (Ssh
) handle
;
9876 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9880 * If the SSH socket itself has backed up, add the total backup
9881 * size on that to any individual buffer on the stdin channel.
9884 if (ssh
->throttled_all
)
9885 override_value
= ssh
->overall_bufsize
;
9887 if (ssh
->version
== 1) {
9888 return override_value
;
9889 } else if (ssh
->version
== 2) {
9891 return override_value
;
9893 return (override_value
+
9894 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
9901 * Called to set the size of the window from SSH's POV.
9903 static void ssh_size(void *handle
, int width
, int height
)
9905 Ssh ssh
= (Ssh
) handle
;
9906 struct Packet
*pktout
;
9908 ssh
->term_width
= width
;
9909 ssh
->term_height
= height
;
9911 switch (ssh
->state
) {
9912 case SSH_STATE_BEFORE_SIZE
:
9913 case SSH_STATE_PREPACKET
:
9914 case SSH_STATE_CLOSED
:
9915 break; /* do nothing */
9916 case SSH_STATE_INTERMED
:
9917 ssh
->size_needed
= TRUE
; /* buffer for later */
9919 case SSH_STATE_SESSION
:
9920 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
9921 if (ssh
->version
== 1) {
9922 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
9923 PKT_INT
, ssh
->term_height
,
9924 PKT_INT
, ssh
->term_width
,
9925 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
9926 } else if (ssh
->mainchan
) {
9927 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "window-change",
9929 ssh2_pkt_adduint32(pktout
, ssh
->term_width
);
9930 ssh2_pkt_adduint32(pktout
, ssh
->term_height
);
9931 ssh2_pkt_adduint32(pktout
, 0);
9932 ssh2_pkt_adduint32(pktout
, 0);
9933 ssh2_pkt_send(ssh
, pktout
);
9941 * Return a list of the special codes that make sense in this
9944 static const struct telnet_special
*ssh_get_specials(void *handle
)
9946 static const struct telnet_special ssh1_ignore_special
[] = {
9947 {"IGNORE message", TS_NOP
}
9949 static const struct telnet_special ssh2_ignore_special
[] = {
9950 {"IGNORE message", TS_NOP
},
9952 static const struct telnet_special ssh2_rekey_special
[] = {
9953 {"Repeat key exchange", TS_REKEY
},
9955 static const struct telnet_special ssh2_session_specials
[] = {
9958 /* These are the signal names defined by RFC 4254.
9959 * They include all the ISO C signals, but are a subset of the POSIX
9960 * required signals. */
9961 {"SIGINT (Interrupt)", TS_SIGINT
},
9962 {"SIGTERM (Terminate)", TS_SIGTERM
},
9963 {"SIGKILL (Kill)", TS_SIGKILL
},
9964 {"SIGQUIT (Quit)", TS_SIGQUIT
},
9965 {"SIGHUP (Hangup)", TS_SIGHUP
},
9966 {"More signals", TS_SUBMENU
},
9967 {"SIGABRT", TS_SIGABRT
}, {"SIGALRM", TS_SIGALRM
},
9968 {"SIGFPE", TS_SIGFPE
}, {"SIGILL", TS_SIGILL
},
9969 {"SIGPIPE", TS_SIGPIPE
}, {"SIGSEGV", TS_SIGSEGV
},
9970 {"SIGUSR1", TS_SIGUSR1
}, {"SIGUSR2", TS_SIGUSR2
},
9973 static const struct telnet_special specials_end
[] = {
9976 /* XXX review this length for any changes: */
9977 static struct telnet_special ssh_specials
[lenof(ssh2_ignore_special
) +
9978 lenof(ssh2_rekey_special
) +
9979 lenof(ssh2_session_specials
) +
9980 lenof(specials_end
)];
9981 Ssh ssh
= (Ssh
) handle
;
9983 #define ADD_SPECIALS(name) \
9985 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9986 memcpy(&ssh_specials[i], name, sizeof name); \
9990 if (ssh
->version
== 1) {
9991 /* Don't bother offering IGNORE if we've decided the remote
9992 * won't cope with it, since we wouldn't bother sending it if
9994 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
9995 ADD_SPECIALS(ssh1_ignore_special
);
9996 } else if (ssh
->version
== 2) {
9997 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
))
9998 ADD_SPECIALS(ssh2_ignore_special
);
9999 if (!(ssh
->remote_bugs
& BUG_SSH2_REKEY
))
10000 ADD_SPECIALS(ssh2_rekey_special
);
10002 ADD_SPECIALS(ssh2_session_specials
);
10003 } /* else we're not ready yet */
10006 ADD_SPECIALS(specials_end
);
10007 return ssh_specials
;
10011 #undef ADD_SPECIALS
10015 * Send special codes. TS_EOF is useful for `plink', so you
10016 * can send an EOF and collect resulting output (e.g. `plink
10019 static void ssh_special(void *handle
, Telnet_Special code
)
10021 Ssh ssh
= (Ssh
) handle
;
10022 struct Packet
*pktout
;
10024 if (code
== TS_EOF
) {
10025 if (ssh
->state
!= SSH_STATE_SESSION
) {
10027 * Buffer the EOF in case we are pre-SESSION, so we can
10028 * send it as soon as we reach SESSION.
10030 if (code
== TS_EOF
)
10031 ssh
->eof_needed
= TRUE
;
10034 if (ssh
->version
== 1) {
10035 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
10036 } else if (ssh
->mainchan
) {
10037 sshfwd_write_eof(ssh
->mainchan
);
10038 ssh
->send_ok
= 0; /* now stop trying to read from stdin */
10040 logevent("Sent EOF message");
10041 } else if (code
== TS_PING
|| code
== TS_NOP
) {
10042 if (ssh
->state
== SSH_STATE_CLOSED
10043 || ssh
->state
== SSH_STATE_PREPACKET
) return;
10044 if (ssh
->version
== 1) {
10045 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
10046 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
10048 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
10049 pktout
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
10050 ssh2_pkt_addstring_start(pktout
);
10051 ssh2_pkt_send_noqueue(ssh
, pktout
);
10054 } else if (code
== TS_REKEY
) {
10055 if (!ssh
->kex_in_progress
&& ssh
->version
== 2) {
10056 do_ssh2_transport(ssh
, "at user request", -1, NULL
);
10058 } else if (code
== TS_BRK
) {
10059 if (ssh
->state
== SSH_STATE_CLOSED
10060 || ssh
->state
== SSH_STATE_PREPACKET
) return;
10061 if (ssh
->version
== 1) {
10062 logevent("Unable to send BREAK signal in SSH-1");
10063 } else if (ssh
->mainchan
) {
10064 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "break", NULL
, NULL
);
10065 ssh2_pkt_adduint32(pktout
, 0); /* default break length */
10066 ssh2_pkt_send(ssh
, pktout
);
10069 /* Is is a POSIX signal? */
10070 char *signame
= NULL
;
10071 if (code
== TS_SIGABRT
) signame
= "ABRT";
10072 if (code
== TS_SIGALRM
) signame
= "ALRM";
10073 if (code
== TS_SIGFPE
) signame
= "FPE";
10074 if (code
== TS_SIGHUP
) signame
= "HUP";
10075 if (code
== TS_SIGILL
) signame
= "ILL";
10076 if (code
== TS_SIGINT
) signame
= "INT";
10077 if (code
== TS_SIGKILL
) signame
= "KILL";
10078 if (code
== TS_SIGPIPE
) signame
= "PIPE";
10079 if (code
== TS_SIGQUIT
) signame
= "QUIT";
10080 if (code
== TS_SIGSEGV
) signame
= "SEGV";
10081 if (code
== TS_SIGTERM
) signame
= "TERM";
10082 if (code
== TS_SIGUSR1
) signame
= "USR1";
10083 if (code
== TS_SIGUSR2
) signame
= "USR2";
10084 /* The SSH-2 protocol does in principle support arbitrary named
10085 * signals, including signame@domain, but we don't support those. */
10087 /* It's a signal. */
10088 if (ssh
->version
== 2 && ssh
->mainchan
) {
10089 pktout
= ssh2_chanreq_init(ssh
->mainchan
, "signal", NULL
, NULL
);
10090 ssh2_pkt_addstring(pktout
, signame
);
10091 ssh2_pkt_send(ssh
, pktout
);
10092 logeventf(ssh
, "Sent signal SIG%s", signame
);
10095 /* Never heard of it. Do nothing */
10100 void *new_sock_channel(void *handle
, Socket s
)
10102 Ssh ssh
= (Ssh
) handle
;
10103 struct ssh_channel
*c
;
10104 c
= snew(struct ssh_channel
);
10107 ssh2_channel_init(c
);
10108 c
->halfopen
= TRUE
;
10109 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
10111 add234(ssh
->channels
, c
);
10116 * This is called when stdout/stderr (the entity to which
10117 * from_backend sends data) manages to clear some backlog.
10119 static void ssh_unthrottle(void *handle
, int bufsize
)
10121 Ssh ssh
= (Ssh
) handle
;
10124 if (ssh
->version
== 1) {
10125 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
10126 ssh
->v1_stdout_throttling
= 0;
10127 ssh_throttle_conn(ssh
, -1);
10130 if (ssh
->mainchan
) {
10131 ssh2_set_window(ssh
->mainchan
,
10132 bufsize
< ssh
->mainchan
->v
.v2
.locmaxwin ?
10133 ssh
->mainchan
->v
.v2
.locmaxwin
- bufsize
: 0);
10134 if (conf_get_int(ssh
->conf
, CONF_ssh_simple
))
10137 buflimit
= ssh
->mainchan
->v
.v2
.locmaxwin
;
10138 if (ssh
->mainchan
->throttling_conn
&& bufsize
<= buflimit
) {
10139 ssh
->mainchan
->throttling_conn
= 0;
10140 ssh_throttle_conn(ssh
, -1);
10146 * Now process any SSH connection data that was stashed in our
10147 * queue while we were frozen.
10149 ssh_process_queued_incoming_data(ssh
);
10152 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
10154 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
10156 struct Packet
*pktout
;
10158 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
10160 if (ssh
->version
== 1) {
10161 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
10162 PKT_INT
, c
->localid
,
10165 /* PKT_STR, <org:orgport>, */
10168 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
10169 ssh2_pkt_addstring(pktout
, "direct-tcpip");
10170 ssh2_pkt_adduint32(pktout
, c
->localid
);
10171 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);/* our window size */
10172 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
10173 ssh2_pkt_addstring(pktout
, hostname
);
10174 ssh2_pkt_adduint32(pktout
, port
);
10176 * We make up values for the originator data; partly it's
10177 * too much hassle to keep track, and partly I'm not
10178 * convinced the server should be told details like that
10179 * about my local network configuration.
10180 * The "originator IP address" is syntactically a numeric
10181 * IP address, and some servers (e.g., Tectia) get upset
10182 * if it doesn't match this syntax.
10184 ssh2_pkt_addstring(pktout
, "0.0.0.0");
10185 ssh2_pkt_adduint32(pktout
, 0);
10186 ssh2_pkt_send(ssh
, pktout
);
10190 static int ssh_connected(void *handle
)
10192 Ssh ssh
= (Ssh
) handle
;
10193 return ssh
->s
!= NULL
;
10196 static int ssh_sendok(void *handle
)
10198 Ssh ssh
= (Ssh
) handle
;
10199 return ssh
->send_ok
;
10202 static int ssh_ldisc(void *handle
, int option
)
10204 Ssh ssh
= (Ssh
) handle
;
10205 if (option
== LD_ECHO
)
10206 return ssh
->echoing
;
10207 if (option
== LD_EDIT
)
10208 return ssh
->editing
;
10212 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
10214 Ssh ssh
= (Ssh
) handle
;
10215 ssh
->ldisc
= ldisc
;
10218 static void ssh_provide_logctx(void *handle
, void *logctx
)
10220 Ssh ssh
= (Ssh
) handle
;
10221 ssh
->logctx
= logctx
;
10224 static int ssh_return_exitcode(void *handle
)
10226 Ssh ssh
= (Ssh
) handle
;
10227 if (ssh
->s
!= NULL
)
10230 return (ssh
->exitcode
>= 0 ? ssh
->exitcode
: INT_MAX
);
10234 * cfg_info for SSH is the currently running version of the
10235 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10237 static int ssh_cfg_info(void *handle
)
10239 Ssh ssh
= (Ssh
) handle
;
10240 return ssh
->version
;
10244 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10245 * that fails. This variable is the means by which scp.c can reach
10246 * into the SSH code and find out which one it got.
10248 extern int ssh_fallback_cmd(void *handle
)
10250 Ssh ssh
= (Ssh
) handle
;
10251 return ssh
->fallback_cmd
;
10254 Backend ssh_backend
= {
10264 ssh_return_exitcode
,
10268 ssh_provide_logctx
,