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 crReturn(z) \
444 *crLine =__LINE__; return (z); case __LINE__:;\
448 *crLine=__LINE__; return; case __LINE__:;\
450 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
451 #define crStopV do{ *crLine = 0; return; }while(0)
452 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
453 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
455 typedef struct ssh_tag
*Ssh
;
458 static struct Packet
*ssh1_pkt_init(int pkt_type
);
459 static struct Packet
*ssh2_pkt_init(int pkt_type
);
460 static void ssh_pkt_ensure(struct Packet
*, int length
);
461 static void ssh_pkt_adddata(struct Packet
*, void *data
, int len
);
462 static void ssh_pkt_addbyte(struct Packet
*, unsigned char value
);
463 static void ssh2_pkt_addbool(struct Packet
*, unsigned char value
);
464 static void ssh_pkt_adduint32(struct Packet
*, unsigned long value
);
465 static void ssh_pkt_addstring_start(struct Packet
*);
466 static void ssh_pkt_addstring_str(struct Packet
*, char *data
);
467 static void ssh_pkt_addstring_data(struct Packet
*, char *data
, int len
);
468 static void ssh_pkt_addstring(struct Packet
*, char *data
);
469 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
);
470 static void ssh1_pkt_addmp(struct Packet
*, Bignum b
);
471 static void ssh2_pkt_addmp(struct Packet
*, Bignum b
);
472 static int ssh2_pkt_construct(Ssh
, struct Packet
*);
473 static void ssh2_pkt_send(Ssh
, struct Packet
*);
474 static void ssh2_pkt_send_noqueue(Ssh
, struct Packet
*);
475 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
,
476 struct Packet
*pktin
);
477 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
,
478 struct Packet
*pktin
);
479 static void ssh2_channel_check_close(struct ssh_channel
*c
);
480 static void ssh_channel_destroy(struct ssh_channel
*c
);
483 * Buffer management constants. There are several of these for
484 * various different purposes:
486 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
487 * on a local data stream before we throttle the whole SSH
488 * connection (in SSH-1 only). Throttling the whole connection is
489 * pretty drastic so we set this high in the hope it won't
492 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
493 * on the SSH connection itself before we defensively throttle
494 * _all_ local data streams. This is pretty drastic too (though
495 * thankfully unlikely in SSH-2 since the window mechanism should
496 * ensure that the server never has any need to throttle its end
497 * of the connection), so we set this high as well.
499 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
502 * - OUR_V2_BIGWIN is the window size we advertise for the only
503 * channel in a simple connection. It must be <= INT_MAX.
505 * - OUR_V2_MAXPKT is the official "maximum packet size" we send
506 * to the remote side. This actually has nothing to do with the
507 * size of the _packet_, but is instead a limit on the amount
508 * of data we're willing to receive in a single SSH2 channel
511 * - OUR_V2_PACKETLIMIT is actually the maximum size of SSH
512 * _packet_ we're prepared to cope with. It must be a multiple
513 * of the cipher block size, and must be at least 35000.
516 #define SSH1_BUFFER_LIMIT 32768
517 #define SSH_MAX_BACKLOG 32768
518 #define OUR_V2_WINSIZE 16384
519 #define OUR_V2_BIGWIN 0x7fffffff
520 #define OUR_V2_MAXPKT 0x4000UL
521 #define OUR_V2_PACKETLIMIT 0x9000UL
523 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
525 const static struct ssh_mac
*macs
[] = {
526 &ssh_hmac_sha1
, &ssh_hmac_sha1_96
, &ssh_hmac_md5
528 const static struct ssh_mac
*buggymacs
[] = {
529 &ssh_hmac_sha1_buggy
, &ssh_hmac_sha1_96_buggy
, &ssh_hmac_md5
532 static void *ssh_comp_none_init(void)
536 static void ssh_comp_none_cleanup(void *handle
)
539 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
540 unsigned char **outblock
, int *outlen
)
544 static int ssh_comp_none_disable(void *handle
)
548 const static struct ssh_compress ssh_comp_none
= {
550 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
551 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
552 ssh_comp_none_disable
, NULL
554 extern const struct ssh_compress ssh_zlib
;
555 const static struct ssh_compress
*compressions
[] = {
556 &ssh_zlib
, &ssh_comp_none
559 enum { /* channel types */
564 CHAN_SOCKDATA_DORMANT
, /* one the remote hasn't confirmed */
566 * CHAN_ZOMBIE is used to indicate a channel for which we've
567 * already destroyed the local data source: for instance, if a
568 * forwarded port experiences a socket error on the local side, we
569 * immediately destroy its local socket and turn the SSH channel
576 * little structure to keep track of outstanding WINDOW_ADJUSTs
584 * 2-3-4 tree storing channels.
587 Ssh ssh
; /* pointer back to main context */
588 unsigned remoteid
, localid
;
590 /* True if we opened this channel but server hasn't confirmed. */
593 * In SSH-1, this value contains four bits:
595 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
596 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
597 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
598 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
600 * A channel is completely finished with when all four bits are set.
602 * In SSH-2, the four bits mean:
604 * 1 We have sent SSH2_MSG_CHANNEL_EOF.
605 * 2 We have sent SSH2_MSG_CHANNEL_CLOSE.
606 * 4 We have received SSH2_MSG_CHANNEL_EOF.
607 * 8 We have received SSH2_MSG_CHANNEL_CLOSE.
609 * A channel is completely finished with when we have both sent
610 * and received CLOSE.
612 * The symbolic constants below use the SSH-2 terminology, which
613 * is a bit confusing in SSH-1, but we have to use _something_.
615 #define CLOSES_SENT_EOF 1
616 #define CLOSES_SENT_CLOSE 2
617 #define CLOSES_RCVD_EOF 4
618 #define CLOSES_RCVD_CLOSE 8
622 * This flag indicates that an EOF is pending on the outgoing side
623 * of the channel: that is, wherever we're getting the data for
624 * this channel has sent us some data followed by EOF. We can't
625 * actually send the EOF until we've finished sending the data, so
626 * we set this flag instead to remind us to do so once our buffer
632 * True if this channel is causing the underlying connection to be
637 struct ssh2_data_channel
{
639 unsigned remwindow
, remmaxpkt
;
640 /* locwindow is signed so we can cope with excess data. */
641 int locwindow
, locmaxwin
;
643 * remlocwin is the amount of local window that we think
644 * the remote end had available to it after it sent the
645 * last data packet or window adjust ack.
649 * These store the list of window adjusts that haven't
652 struct winadj
*winadj_head
, *winadj_tail
;
653 enum { THROTTLED
, UNTHROTTLING
, UNTHROTTLED
} throttle_state
;
657 struct ssh_agent_channel
{
658 unsigned char *message
;
659 unsigned char msglen
[4];
660 unsigned lensofar
, totallen
;
662 struct ssh_x11_channel
{
665 struct ssh_pfd_channel
{
672 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
673 * use this structure in different ways, reflecting SSH-2's
674 * altogether saner approach to port forwarding.
676 * In SSH-1, you arrange a remote forwarding by sending the server
677 * the remote port number, and the local destination host:port.
678 * When a connection comes in, the server sends you back that
679 * host:port pair, and you connect to it. This is a ready-made
680 * security hole if you're not on the ball: a malicious server
681 * could send you back _any_ host:port pair, so if you trustingly
682 * connect to the address it gives you then you've just opened the
683 * entire inside of your corporate network just by connecting
684 * through it to a dodgy SSH server. Hence, we must store a list of
685 * host:port pairs we _are_ trying to forward to, and reject a
686 * connection request from the server if it's not in the list.
688 * In SSH-2, each side of the connection minds its own business and
689 * doesn't send unnecessary information to the other. You arrange a
690 * remote forwarding by sending the server just the remote port
691 * number. When a connection comes in, the server tells you which
692 * of its ports was connected to; and _you_ have to remember what
693 * local host:port pair went with that port number.
695 * Hence, in SSH-1 this structure is indexed by destination
696 * host:port pair, whereas in SSH-2 it is indexed by source port.
698 struct ssh_portfwd
; /* forward declaration */
700 struct ssh_rportfwd
{
701 unsigned sport
, dport
;
704 struct ssh_portfwd
*pfrec
;
706 #define free_rportfwd(pf) ( \
707 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
710 * Separately to the rportfwd tree (which is for looking up port
711 * open requests from the server), a tree of _these_ structures is
712 * used to keep track of all the currently open port forwardings,
713 * so that we can reconfigure in mid-session if the user requests
717 enum { DESTROY
, KEEP
, CREATE
} status
;
719 unsigned sport
, dport
;
722 struct ssh_rportfwd
*remote
;
726 #define free_portfwd(pf) ( \
727 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
728 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
731 long length
; /* length of `data' actually used */
732 long forcepad
; /* SSH-2: force padding to at least this length */
733 int type
; /* only used for incoming packets */
734 unsigned long sequence
; /* SSH-2 incoming sequence number */
735 unsigned char *data
; /* allocated storage */
736 unsigned char *body
; /* offset of payload within `data' */
737 long savedpos
; /* temporary index into `data' (for strings) */
738 long maxlen
; /* amount of storage allocated for `data' */
739 long encrypted_len
; /* for SSH-2 total-size counting */
742 * State associated with packet logging
746 struct logblank_t
*blanks
;
749 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
750 struct Packet
*pktin
);
751 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
752 struct Packet
*pktin
);
753 static void ssh1_protocol_setup(Ssh ssh
);
754 static void ssh2_protocol_setup(Ssh ssh
);
755 static void ssh_size(void *handle
, int width
, int height
);
756 static void ssh_special(void *handle
, Telnet_Special
);
757 static int ssh2_try_send(struct ssh_channel
*c
);
758 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
759 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
760 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
);
761 static int ssh_sendbuffer(void *handle
);
762 static int ssh_do_close(Ssh ssh
, int notify_exit
);
763 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
);
764 static int ssh2_pkt_getbool(struct Packet
*pkt
);
765 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
);
766 static void ssh2_timer(void *ctx
, long now
);
767 static int do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
768 struct Packet
*pktin
);
770 struct rdpkt1_state_tag
{
771 long len
, pad
, biglen
, to_read
;
772 unsigned long realcrc
, gotcrc
;
776 struct Packet
*pktin
;
779 struct rdpkt2_state_tag
{
780 long len
, pad
, payload
, packetlen
, maclen
;
783 unsigned long incoming_sequence
;
784 struct Packet
*pktin
;
787 typedef void (*handler_fn_t
)(Ssh ssh
, struct Packet
*pktin
);
788 typedef void (*chandler_fn_t
)(Ssh ssh
, struct Packet
*pktin
, void *ctx
);
790 struct queued_handler
;
791 struct queued_handler
{
793 chandler_fn_t handler
;
795 struct queued_handler
*next
;
799 const struct plug_function_table
*fn
;
800 /* the above field _must_ be first in the structure */
810 unsigned char session_key
[32];
812 int v1_remote_protoflags
;
813 int v1_local_protoflags
;
814 int agentfwd_enabled
;
817 const struct ssh_cipher
*cipher
;
820 const struct ssh2_cipher
*cscipher
, *sccipher
;
821 void *cs_cipher_ctx
, *sc_cipher_ctx
;
822 const struct ssh_mac
*csmac
, *scmac
;
823 void *cs_mac_ctx
, *sc_mac_ctx
;
824 const struct ssh_compress
*cscomp
, *sccomp
;
825 void *cs_comp_ctx
, *sc_comp_ctx
;
826 const struct ssh_kex
*kex
;
827 const struct ssh_signkey
*hostkey
;
828 unsigned char v2_session_id
[SSH2_KEX_MAX_HASH_LEN
];
829 int v2_session_id_len
;
835 int echoing
, editing
;
839 int ospeed
, ispeed
; /* temporaries */
840 int term_width
, term_height
;
842 tree234
*channels
; /* indexed by local id */
843 struct ssh_channel
*mainchan
; /* primary session channel */
844 int ncmode
; /* is primary channel direct-tcpip? */
849 tree234
*rportfwds
, *portfwds
;
853 SSH_STATE_BEFORE_SIZE
,
859 int size_needed
, eof_needed
;
860 int sent_console_eof
;
861 int got_pty
; /* affects EOF behaviour on main channel */
863 struct Packet
**queue
;
864 int queuelen
, queuesize
;
866 unsigned char *deferred_send_data
;
867 int deferred_len
, deferred_size
;
870 * Gross hack: pscp will try to start SFTP but fall back to
871 * scp1 if that fails. This variable is the means by which
872 * scp.c can reach into the SSH code and find out which one it
877 bufchain banner
; /* accumulates banners during do_ssh2_authconn */
882 struct X11Display
*x11disp
;
885 int conn_throttle_count
;
888 int v1_stdout_throttling
;
889 unsigned long v2_outgoing_sequence
;
891 int ssh1_rdpkt_crstate
;
892 int ssh2_rdpkt_crstate
;
893 int ssh_gotdata_crstate
;
894 int do_ssh1_connection_crstate
;
896 void *do_ssh_init_state
;
897 void *do_ssh1_login_state
;
898 void *do_ssh2_transport_state
;
899 void *do_ssh2_authconn_state
;
901 struct rdpkt1_state_tag rdpkt1_state
;
902 struct rdpkt2_state_tag rdpkt2_state
;
904 /* SSH-1 and SSH-2 use this for different things, but both use it */
905 int protocol_initial_phase_done
;
907 void (*protocol
) (Ssh ssh
, void *vin
, int inlen
,
909 struct Packet
*(*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
912 * We maintain our own copy of a Conf structure here. That way,
913 * when we're passed a new one for reconfiguration, we can check
914 * the differences and potentially reconfigure port forwardings
915 * etc in mid-session.
920 * Values cached out of conf so as to avoid the tree234 lookup
921 * cost every time they're used.
926 * Dynamically allocated username string created during SSH
927 * login. Stored in here rather than in the coroutine state so
928 * that it'll be reliably freed if we shut down the SSH session
929 * at some unexpected moment.
934 * Used to transfer data back from async callbacks.
936 void *agent_response
;
937 int agent_response_len
;
941 * The SSH connection can be set as `frozen', meaning we are
942 * not currently accepting incoming data from the network. This
943 * is slightly more serious than setting the _socket_ as
944 * frozen, because we may already have had data passed to us
945 * from the network which we need to delay processing until
946 * after the freeze is lifted, so we also need a bufchain to
950 bufchain queued_incoming_data
;
953 * Dispatch table for packet types that we may have to deal
956 handler_fn_t packet_dispatch
[256];
959 * Queues of one-off handler functions for success/failure
960 * indications from a request.
962 struct queued_handler
*qhead
, *qtail
;
965 * This module deals with sending keepalives.
970 * Track incoming and outgoing data sizes and time, for
973 unsigned long incoming_data_size
, outgoing_data_size
, deferred_data_size
;
974 unsigned long max_data_size
;
976 long next_rekey
, last_rekey
;
977 char *deferred_rekey_reason
; /* points to STATIC string; don't free */
980 * Fully qualified host name, which we need if doing GSSAPI.
986 * GSSAPI libraries for this session.
988 struct ssh_gss_liblist
*gsslibs
;
992 #define logevent(s) logevent(ssh->frontend, s)
994 /* logevent, only printf-formatted. */
995 static void logeventf(Ssh ssh
, const char *fmt
, ...)
1001 buf
= dupvprintf(fmt
, ap
);
1007 #define bombout(msg) \
1009 char *text = dupprintf msg; \
1010 ssh_do_close(ssh, FALSE); \
1012 connection_fatal(ssh->frontend, "%s", text); \
1016 /* Functions to leave bits out of the SSH packet log file. */
1018 static void dont_log_password(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1020 if (conf_get_int(ssh
->conf
, CONF_logomitpass
))
1021 pkt
->logmode
= blanktype
;
1024 static void dont_log_data(Ssh ssh
, struct Packet
*pkt
, int blanktype
)
1026 if (ssh
->logomitdata
)
1027 pkt
->logmode
= blanktype
;
1030 static void end_log_omission(Ssh ssh
, struct Packet
*pkt
)
1032 pkt
->logmode
= PKTLOG_EMIT
;
1035 /* Helper function for common bits of parsing ttymodes. */
1036 static void parse_ttymodes(Ssh ssh
,
1037 void (*do_mode
)(void *data
, char *mode
, char *val
),
1042 for (val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, NULL
, &key
);
1044 val
= conf_get_str_strs(ssh
->conf
, CONF_ttymodes
, key
, &key
)) {
1046 * val[0] is either 'V', indicating that an explicit value
1047 * follows it, or 'A' indicating that we should pass the
1048 * value through from the local environment via get_ttymode.
1051 val
= get_ttymode(ssh
->frontend
, key
);
1053 val
++; /* skip the 'V' */
1055 do_mode(data
, key
, val
);
1059 static int ssh_channelcmp(void *av
, void *bv
)
1061 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
1062 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1063 if (a
->localid
< b
->localid
)
1065 if (a
->localid
> b
->localid
)
1069 static int ssh_channelfind(void *av
, void *bv
)
1071 unsigned *a
= (unsigned *) av
;
1072 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
1073 if (*a
< b
->localid
)
1075 if (*a
> b
->localid
)
1080 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
1082 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1083 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1085 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
1086 return i
< 0 ?
-1 : +1;
1087 if (a
->dport
> b
->dport
)
1089 if (a
->dport
< b
->dport
)
1094 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
1096 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
1097 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
1099 if (a
->sport
> b
->sport
)
1101 if (a
->sport
< b
->sport
)
1107 * Special form of strcmp which can cope with NULL inputs. NULL is
1108 * defined to sort before even the empty string.
1110 static int nullstrcmp(const char *a
, const char *b
)
1112 if (a
== NULL
&& b
== NULL
)
1118 return strcmp(a
, b
);
1121 static int ssh_portcmp(void *av
, void *bv
)
1123 struct ssh_portfwd
*a
= (struct ssh_portfwd
*) av
;
1124 struct ssh_portfwd
*b
= (struct ssh_portfwd
*) bv
;
1126 if (a
->type
> b
->type
)
1128 if (a
->type
< b
->type
)
1130 if (a
->addressfamily
> b
->addressfamily
)
1132 if (a
->addressfamily
< b
->addressfamily
)
1134 if ( (i
= nullstrcmp(a
->saddr
, b
->saddr
)) != 0)
1135 return i
< 0 ?
-1 : +1;
1136 if (a
->sport
> b
->sport
)
1138 if (a
->sport
< b
->sport
)
1140 if (a
->type
!= 'D') {
1141 if ( (i
= nullstrcmp(a
->daddr
, b
->daddr
)) != 0)
1142 return i
< 0 ?
-1 : +1;
1143 if (a
->dport
> b
->dport
)
1145 if (a
->dport
< b
->dport
)
1151 static int alloc_channel_id(Ssh ssh
)
1153 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
1154 unsigned low
, high
, mid
;
1156 struct ssh_channel
*c
;
1159 * First-fit allocation of channel numbers: always pick the
1160 * lowest unused one. To do this, binary-search using the
1161 * counted B-tree to find the largest channel ID which is in a
1162 * contiguous sequence from the beginning. (Precisely
1163 * everything in that sequence must have ID equal to its tree
1164 * index plus CHANNEL_NUMBER_OFFSET.)
1166 tsize
= count234(ssh
->channels
);
1170 while (high
- low
> 1) {
1171 mid
= (high
+ low
) / 2;
1172 c
= index234(ssh
->channels
, mid
);
1173 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
1174 low
= mid
; /* this one is fine */
1176 high
= mid
; /* this one is past it */
1179 * Now low points to either -1, or the tree index of the
1180 * largest ID in the initial sequence.
1183 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1184 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
1186 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
1189 static void c_write_stderr(int trusted
, const char *buf
, int len
)
1192 for (i
= 0; i
< len
; i
++)
1193 if (buf
[i
] != '\r' && (trusted
|| buf
[i
] == '\n' || (buf
[i
] & 0x60)))
1194 fputc(buf
[i
], stderr
);
1197 static void c_write(Ssh ssh
, const char *buf
, int len
)
1199 if (flags
& FLAG_STDERR
)
1200 c_write_stderr(1, buf
, len
);
1202 from_backend(ssh
->frontend
, 1, buf
, len
);
1205 static void c_write_untrusted(Ssh ssh
, const char *buf
, int len
)
1207 if (flags
& FLAG_STDERR
)
1208 c_write_stderr(0, buf
, len
);
1210 from_backend_untrusted(ssh
->frontend
, buf
, len
);
1213 static void c_write_str(Ssh ssh
, const char *buf
)
1215 c_write(ssh
, buf
, strlen(buf
));
1218 static void ssh_free_packet(struct Packet
*pkt
)
1223 static struct Packet
*ssh_new_packet(void)
1225 struct Packet
*pkt
= snew(struct Packet
);
1227 pkt
->body
= pkt
->data
= NULL
;
1229 pkt
->logmode
= PKTLOG_EMIT
;
1237 * Collect incoming data in the incoming packet buffer.
1238 * Decipher and verify the packet when it is completely read.
1239 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1240 * Update the *data and *datalen variables.
1241 * Return a Packet structure when a packet is completed.
1243 static struct Packet
*ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1245 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
1247 crBegin(ssh
->ssh1_rdpkt_crstate
);
1249 st
->pktin
= ssh_new_packet();
1251 st
->pktin
->type
= 0;
1252 st
->pktin
->length
= 0;
1254 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
1255 while ((*datalen
) == 0)
1257 st
->len
= (st
->len
<< 8) + **data
;
1258 (*data
)++, (*datalen
)--;
1261 st
->pad
= 8 - (st
->len
% 8);
1262 st
->biglen
= st
->len
+ st
->pad
;
1263 st
->pktin
->length
= st
->len
- 5;
1265 if (st
->biglen
< 0) {
1266 bombout(("Extremely large packet length from server suggests"
1267 " data stream corruption"));
1268 ssh_free_packet(st
->pktin
);
1272 st
->pktin
->maxlen
= st
->biglen
;
1273 st
->pktin
->data
= snewn(st
->biglen
+ APIEXTRA
, unsigned char);
1275 st
->to_read
= st
->biglen
;
1276 st
->p
= st
->pktin
->data
;
1277 while (st
->to_read
> 0) {
1278 st
->chunk
= st
->to_read
;
1279 while ((*datalen
) == 0)
1281 if (st
->chunk
> (*datalen
))
1282 st
->chunk
= (*datalen
);
1283 memcpy(st
->p
, *data
, st
->chunk
);
1285 *datalen
-= st
->chunk
;
1287 st
->to_read
-= st
->chunk
;
1290 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, st
->pktin
->data
,
1291 st
->biglen
, NULL
)) {
1292 bombout(("Network attack (CRC compensation) detected!"));
1293 ssh_free_packet(st
->pktin
);
1298 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, st
->pktin
->data
, st
->biglen
);
1300 st
->realcrc
= crc32_compute(st
->pktin
->data
, st
->biglen
- 4);
1301 st
->gotcrc
= GET_32BIT(st
->pktin
->data
+ st
->biglen
- 4);
1302 if (st
->gotcrc
!= st
->realcrc
) {
1303 bombout(("Incorrect CRC received on packet"));
1304 ssh_free_packet(st
->pktin
);
1308 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1309 st
->pktin
->savedpos
= 0;
1311 if (ssh
->v1_compressing
) {
1312 unsigned char *decompblk
;
1314 if (!zlib_decompress_block(ssh
->sc_comp_ctx
,
1315 st
->pktin
->body
- 1, st
->pktin
->length
+ 1,
1316 &decompblk
, &decomplen
)) {
1317 bombout(("Zlib decompression encountered invalid data"));
1318 ssh_free_packet(st
->pktin
);
1322 if (st
->pktin
->maxlen
< st
->pad
+ decomplen
) {
1323 st
->pktin
->maxlen
= st
->pad
+ decomplen
;
1324 st
->pktin
->data
= sresize(st
->pktin
->data
,
1325 st
->pktin
->maxlen
+ APIEXTRA
,
1327 st
->pktin
->body
= st
->pktin
->data
+ st
->pad
+ 1;
1330 memcpy(st
->pktin
->body
- 1, decompblk
, decomplen
);
1332 st
->pktin
->length
= decomplen
- 1;
1335 st
->pktin
->type
= st
->pktin
->body
[-1];
1338 * Log incoming packet, possibly omitting sensitive fields.
1342 struct logblank_t blank
;
1343 if (ssh
->logomitdata
) {
1344 int do_blank
= FALSE
, blank_prefix
= 0;
1345 /* "Session data" packets - omit the data field */
1346 if ((st
->pktin
->type
== SSH1_SMSG_STDOUT_DATA
) ||
1347 (st
->pktin
->type
== SSH1_SMSG_STDERR_DATA
)) {
1348 do_blank
= TRUE
; blank_prefix
= 4;
1349 } else if (st
->pktin
->type
== SSH1_MSG_CHANNEL_DATA
) {
1350 do_blank
= TRUE
; blank_prefix
= 8;
1353 blank
.offset
= blank_prefix
;
1354 blank
.len
= st
->pktin
->length
;
1355 blank
.type
= PKTLOG_OMIT
;
1359 log_packet(ssh
->logctx
,
1360 PKT_INCOMING
, st
->pktin
->type
,
1361 ssh1_pkt_type(st
->pktin
->type
),
1362 st
->pktin
->body
, st
->pktin
->length
,
1363 nblanks
, &blank
, NULL
);
1366 crFinish(st
->pktin
);
1369 static struct Packet
*ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
1371 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
1373 crBegin(ssh
->ssh2_rdpkt_crstate
);
1375 st
->pktin
= ssh_new_packet();
1377 st
->pktin
->type
= 0;
1378 st
->pktin
->length
= 0;
1380 st
->cipherblk
= ssh
->sccipher
->blksize
;
1383 if (st
->cipherblk
< 8)
1385 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
1387 if (ssh
->sccipher
&& (ssh
->sccipher
->flags
& SSH_CIPHER_IS_CBC
) &&
1390 * When dealing with a CBC-mode cipher, we want to avoid the
1391 * possibility of an attacker's tweaking the ciphertext stream
1392 * so as to cause us to feed the same block to the block
1393 * cipher more than once and thus leak information
1394 * (VU#958563). The way we do this is not to take any
1395 * decisions on the basis of anything we've decrypted until
1396 * we've verified it with a MAC. That includes the packet
1397 * length, so we just read data and check the MAC repeatedly,
1398 * and when the MAC passes, see if the length we've got is
1402 /* May as well allocate the whole lot now. */
1403 st
->pktin
->data
= snewn(OUR_V2_PACKETLIMIT
+ st
->maclen
+ APIEXTRA
,
1406 /* Read an amount corresponding to the MAC. */
1407 for (st
->i
= 0; st
->i
< st
->maclen
; st
->i
++) {
1408 while ((*datalen
) == 0)
1410 st
->pktin
->data
[st
->i
] = *(*data
)++;
1416 unsigned char seq
[4];
1417 ssh
->scmac
->start(ssh
->sc_mac_ctx
);
1418 PUT_32BIT(seq
, st
->incoming_sequence
);
1419 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
, seq
, 4);
1422 for (;;) { /* Once around this loop per cipher block. */
1423 /* Read another cipher-block's worth, and tack it onto the end. */
1424 for (st
->i
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1425 while ((*datalen
) == 0)
1427 st
->pktin
->data
[st
->packetlen
+st
->maclen
+st
->i
] = *(*data
)++;
1430 /* Decrypt one more block (a little further back in the stream). */
1431 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1432 st
->pktin
->data
+ st
->packetlen
,
1434 /* Feed that block to the MAC. */
1435 ssh
->scmac
->bytes(ssh
->sc_mac_ctx
,
1436 st
->pktin
->data
+ st
->packetlen
, st
->cipherblk
);
1437 st
->packetlen
+= st
->cipherblk
;
1438 /* See if that gives us a valid packet. */
1439 if (ssh
->scmac
->verresult(ssh
->sc_mac_ctx
,
1440 st
->pktin
->data
+ st
->packetlen
) &&
1441 (st
->len
= GET_32BIT(st
->pktin
->data
)) + 4 == st
->packetlen
)
1443 if (st
->packetlen
>= OUR_V2_PACKETLIMIT
) {
1444 bombout(("No valid incoming packet found"));
1445 ssh_free_packet(st
->pktin
);
1449 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1450 st
->pktin
->data
= sresize(st
->pktin
->data
,
1451 st
->pktin
->maxlen
+ APIEXTRA
,
1454 st
->pktin
->data
= snewn(st
->cipherblk
+ APIEXTRA
, unsigned char);
1457 * Acquire and decrypt the first block of the packet. This will
1458 * contain the length and padding details.
1460 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
1461 while ((*datalen
) == 0)
1463 st
->pktin
->data
[st
->i
] = *(*data
)++;
1468 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1469 st
->pktin
->data
, st
->cipherblk
);
1472 * Now get the length figure.
1474 st
->len
= GET_32BIT(st
->pktin
->data
);
1477 * _Completely_ silly lengths should be stomped on before they
1478 * do us any more damage.
1480 if (st
->len
< 0 || st
->len
> OUR_V2_PACKETLIMIT
||
1481 (st
->len
+ 4) % st
->cipherblk
!= 0) {
1482 bombout(("Incoming packet was garbled on decryption"));
1483 ssh_free_packet(st
->pktin
);
1488 * So now we can work out the total packet length.
1490 st
->packetlen
= st
->len
+ 4;
1493 * Allocate memory for the rest of the packet.
1495 st
->pktin
->maxlen
= st
->packetlen
+ st
->maclen
;
1496 st
->pktin
->data
= sresize(st
->pktin
->data
,
1497 st
->pktin
->maxlen
+ APIEXTRA
,
1501 * Read and decrypt the remainder of the packet.
1503 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
1505 while ((*datalen
) == 0)
1507 st
->pktin
->data
[st
->i
] = *(*data
)++;
1510 /* Decrypt everything _except_ the MAC. */
1512 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1513 st
->pktin
->data
+ st
->cipherblk
,
1514 st
->packetlen
- st
->cipherblk
);
1520 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, st
->pktin
->data
,
1521 st
->len
+ 4, st
->incoming_sequence
)) {
1522 bombout(("Incorrect MAC received on packet"));
1523 ssh_free_packet(st
->pktin
);
1527 /* Get and sanity-check the amount of random padding. */
1528 st
->pad
= st
->pktin
->data
[4];
1529 if (st
->pad
< 4 || st
->len
- st
->pad
< 1) {
1530 bombout(("Invalid padding length on received packet"));
1531 ssh_free_packet(st
->pktin
);
1535 * This enables us to deduce the payload length.
1537 st
->payload
= st
->len
- st
->pad
- 1;
1539 st
->pktin
->length
= st
->payload
+ 5;
1540 st
->pktin
->encrypted_len
= st
->packetlen
;
1542 st
->pktin
->sequence
= st
->incoming_sequence
++;
1545 * Decompress packet payload.
1548 unsigned char *newpayload
;
1551 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1552 st
->pktin
->data
+ 5, st
->pktin
->length
- 5,
1553 &newpayload
, &newlen
)) {
1554 if (st
->pktin
->maxlen
< newlen
+ 5) {
1555 st
->pktin
->maxlen
= newlen
+ 5;
1556 st
->pktin
->data
= sresize(st
->pktin
->data
,
1557 st
->pktin
->maxlen
+ APIEXTRA
,
1560 st
->pktin
->length
= 5 + newlen
;
1561 memcpy(st
->pktin
->data
+ 5, newpayload
, newlen
);
1566 st
->pktin
->savedpos
= 6;
1567 st
->pktin
->body
= st
->pktin
->data
;
1568 st
->pktin
->type
= st
->pktin
->data
[5];
1571 * Log incoming packet, possibly omitting sensitive fields.
1575 struct logblank_t blank
;
1576 if (ssh
->logomitdata
) {
1577 int do_blank
= FALSE
, blank_prefix
= 0;
1578 /* "Session data" packets - omit the data field */
1579 if (st
->pktin
->type
== SSH2_MSG_CHANNEL_DATA
) {
1580 do_blank
= TRUE
; blank_prefix
= 8;
1581 } else if (st
->pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
1582 do_blank
= TRUE
; blank_prefix
= 12;
1585 blank
.offset
= blank_prefix
;
1586 blank
.len
= (st
->pktin
->length
-6) - blank_prefix
;
1587 blank
.type
= PKTLOG_OMIT
;
1591 log_packet(ssh
->logctx
, PKT_INCOMING
, st
->pktin
->type
,
1592 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
1594 st
->pktin
->data
+6, st
->pktin
->length
-6,
1595 nblanks
, &blank
, &st
->pktin
->sequence
);
1598 crFinish(st
->pktin
);
1601 static int s_wrpkt_prepare(Ssh ssh
, struct Packet
*pkt
, int *offset_p
)
1603 int pad
, biglen
, i
, pktoffs
;
1607 * XXX various versions of SC (including 8.8.4) screw up the
1608 * register allocation in this function and use the same register
1609 * (D6) for len and as a temporary, with predictable results. The
1610 * following sledgehammer prevents this.
1617 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[12],
1618 ssh1_pkt_type(pkt
->data
[12]),
1619 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1620 pkt
->nblanks
, pkt
->blanks
, NULL
);
1621 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1624 if (ssh
->v1_compressing
) {
1625 unsigned char *compblk
;
1627 zlib_compress_block(ssh
->cs_comp_ctx
,
1628 pkt
->data
+ 12, pkt
->length
- 12,
1629 &compblk
, &complen
);
1630 ssh_pkt_ensure(pkt
, complen
+ 2); /* just in case it's got bigger */
1631 memcpy(pkt
->data
+ 12, compblk
, complen
);
1633 pkt
->length
= complen
+ 12;
1636 ssh_pkt_ensure(pkt
, pkt
->length
+ 4); /* space for CRC */
1638 len
= pkt
->length
- 4 - 8; /* len(type+data+CRC) */
1639 pad
= 8 - (len
% 8);
1641 biglen
= len
+ pad
; /* len(padding+type+data+CRC) */
1643 for (i
= pktoffs
; i
< 4+8; i
++)
1644 pkt
->data
[i
] = random_byte();
1645 crc
= crc32_compute(pkt
->data
+ pktoffs
+ 4, biglen
- 4); /* all ex len */
1646 PUT_32BIT(pkt
->data
+ pktoffs
+ 4 + biglen
- 4, crc
);
1647 PUT_32BIT(pkt
->data
+ pktoffs
, len
);
1650 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
,
1651 pkt
->data
+ pktoffs
+ 4, biglen
);
1653 if (offset_p
) *offset_p
= pktoffs
;
1654 return biglen
+ 4; /* len(length+padding+type+data+CRC) */
1657 static int s_write(Ssh ssh
, void *data
, int len
)
1660 log_packet(ssh
->logctx
, PKT_OUTGOING
, -1, NULL
, data
, len
,
1662 return sk_write(ssh
->s
, (char *)data
, len
);
1665 static void s_wrpkt(Ssh ssh
, struct Packet
*pkt
)
1667 int len
, backlog
, offset
;
1668 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1669 backlog
= s_write(ssh
, pkt
->data
+ offset
, len
);
1670 if (backlog
> SSH_MAX_BACKLOG
)
1671 ssh_throttle_all(ssh
, 1, backlog
);
1672 ssh_free_packet(pkt
);
1675 static void s_wrpkt_defer(Ssh ssh
, struct Packet
*pkt
)
1678 len
= s_wrpkt_prepare(ssh
, pkt
, &offset
);
1679 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1680 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1681 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
1685 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
,
1686 pkt
->data
+ offset
, len
);
1687 ssh
->deferred_len
+= len
;
1688 ssh_free_packet(pkt
);
1692 * Construct a SSH-1 packet with the specified contents.
1693 * (This all-at-once interface used to be the only one, but now SSH-1
1694 * packets can also be constructed incrementally.)
1696 static struct Packet
*construct_packet(Ssh ssh
, int pkttype
, va_list ap
)
1702 pkt
= ssh1_pkt_init(pkttype
);
1704 while ((argtype
= va_arg(ap
, int)) != PKT_END
) {
1705 unsigned char *argp
, argchar
;
1707 unsigned long argint
;
1710 /* Actual fields in the packet */
1712 argint
= va_arg(ap
, int);
1713 ssh_pkt_adduint32(pkt
, argint
);
1716 argchar
= (unsigned char) va_arg(ap
, int);
1717 ssh_pkt_addbyte(pkt
, argchar
);
1720 argp
= va_arg(ap
, unsigned char *);
1721 arglen
= va_arg(ap
, int);
1722 ssh_pkt_adddata(pkt
, argp
, arglen
);
1725 sargp
= va_arg(ap
, char *);
1726 ssh_pkt_addstring(pkt
, sargp
);
1729 bn
= va_arg(ap
, Bignum
);
1730 ssh1_pkt_addmp(pkt
, bn
);
1732 /* Tokens for modifications to packet logging */
1734 dont_log_password(ssh
, pkt
, PKTLOG_BLANK
);
1737 dont_log_data(ssh
, pkt
, PKTLOG_OMIT
);
1740 end_log_omission(ssh
, pkt
);
1748 static void send_packet(Ssh ssh
, int pkttype
, ...)
1752 va_start(ap
, pkttype
);
1753 pkt
= construct_packet(ssh
, pkttype
, ap
);
1758 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1762 va_start(ap
, pkttype
);
1763 pkt
= construct_packet(ssh
, pkttype
, ap
);
1765 s_wrpkt_defer(ssh
, pkt
);
1768 static int ssh_versioncmp(char *a
, char *b
)
1771 unsigned long av
, bv
;
1773 av
= strtoul(a
, &ae
, 10);
1774 bv
= strtoul(b
, &be
, 10);
1776 return (av
< bv ?
-1 : +1);
1781 av
= strtoul(ae
, &ae
, 10);
1782 bv
= strtoul(be
, &be
, 10);
1784 return (av
< bv ?
-1 : +1);
1789 * Utility routines for putting an SSH-protocol `string' and
1790 * `uint32' into a hash state.
1792 static void hash_string(const struct ssh_hash
*h
, void *s
, void *str
, int len
)
1794 unsigned char lenblk
[4];
1795 PUT_32BIT(lenblk
, len
);
1796 h
->bytes(s
, lenblk
, 4);
1797 h
->bytes(s
, str
, len
);
1800 static void hash_uint32(const struct ssh_hash
*h
, void *s
, unsigned i
)
1802 unsigned char intblk
[4];
1803 PUT_32BIT(intblk
, i
);
1804 h
->bytes(s
, intblk
, 4);
1808 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1810 static void ssh_pkt_ensure(struct Packet
*pkt
, int length
)
1812 if (pkt
->maxlen
< length
) {
1813 unsigned char *body
= pkt
->body
;
1814 int offset
= body ? body
- pkt
->data
: 0;
1815 pkt
->maxlen
= length
+ 256;
1816 pkt
->data
= sresize(pkt
->data
, pkt
->maxlen
+ APIEXTRA
, unsigned char);
1817 if (body
) pkt
->body
= pkt
->data
+ offset
;
1820 static void ssh_pkt_adddata(struct Packet
*pkt
, void *data
, int len
)
1822 if (pkt
->logmode
!= PKTLOG_EMIT
) {
1824 pkt
->blanks
= sresize(pkt
->blanks
, pkt
->nblanks
, struct logblank_t
);
1826 pkt
->blanks
[pkt
->nblanks
-1].offset
= pkt
->length
-
1827 (pkt
->body
- pkt
->data
);
1828 pkt
->blanks
[pkt
->nblanks
-1].len
= len
;
1829 pkt
->blanks
[pkt
->nblanks
-1].type
= pkt
->logmode
;
1832 ssh_pkt_ensure(pkt
, pkt
->length
);
1833 memcpy(pkt
->data
+ pkt
->length
- len
, data
, len
);
1835 static void ssh_pkt_addbyte(struct Packet
*pkt
, unsigned char byte
)
1837 ssh_pkt_adddata(pkt
, &byte
, 1);
1839 static void ssh2_pkt_addbool(struct Packet
*pkt
, unsigned char value
)
1841 ssh_pkt_adddata(pkt
, &value
, 1);
1843 static void ssh_pkt_adduint32(struct Packet
*pkt
, unsigned long value
)
1846 PUT_32BIT(x
, value
);
1847 ssh_pkt_adddata(pkt
, x
, 4);
1849 static void ssh_pkt_addstring_start(struct Packet
*pkt
)
1851 ssh_pkt_adduint32(pkt
, 0);
1852 pkt
->savedpos
= pkt
->length
;
1854 static void ssh_pkt_addstring_str(struct Packet
*pkt
, char *data
)
1856 ssh_pkt_adddata(pkt
, data
, strlen(data
));
1857 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1859 static void ssh_pkt_addstring_data(struct Packet
*pkt
, char *data
, int len
)
1861 ssh_pkt_adddata(pkt
, data
, len
);
1862 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
1864 static void ssh_pkt_addstring(struct Packet
*pkt
, char *data
)
1866 ssh_pkt_addstring_start(pkt
);
1867 ssh_pkt_addstring_str(pkt
, data
);
1869 static void ssh1_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1871 int len
= ssh1_bignum_length(b
);
1872 unsigned char *data
= snewn(len
, unsigned char);
1873 (void) ssh1_write_bignum(data
, b
);
1874 ssh_pkt_adddata(pkt
, data
, len
);
1877 static unsigned char *ssh2_mpint_fmt(Bignum b
, int *len
)
1880 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1881 p
= snewn(n
+ 1, unsigned char);
1883 for (i
= 1; i
<= n
; i
++)
1884 p
[i
] = bignum_byte(b
, n
- i
);
1886 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1888 memmove(p
, p
+ i
, n
+ 1 - i
);
1892 static void ssh2_pkt_addmp(struct Packet
*pkt
, Bignum b
)
1896 p
= ssh2_mpint_fmt(b
, &len
);
1897 ssh_pkt_addstring_start(pkt
);
1898 ssh_pkt_addstring_data(pkt
, (char *)p
, len
);
1902 static struct Packet
*ssh1_pkt_init(int pkt_type
)
1904 struct Packet
*pkt
= ssh_new_packet();
1905 pkt
->length
= 4 + 8; /* space for length + max padding */
1906 ssh_pkt_addbyte(pkt
, pkt_type
);
1907 pkt
->body
= pkt
->data
+ pkt
->length
;
1911 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1912 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1913 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1914 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1915 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1916 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1917 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1918 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1919 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1921 static struct Packet
*ssh2_pkt_init(int pkt_type
)
1923 struct Packet
*pkt
= ssh_new_packet();
1924 pkt
->length
= 5; /* space for packet length + padding length */
1926 ssh_pkt_addbyte(pkt
, (unsigned char) pkt_type
);
1927 pkt
->body
= pkt
->data
+ pkt
->length
; /* after packet type */
1932 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1933 * put the MAC on it. Final packet, ready to be sent, is stored in
1934 * pkt->data. Total length is returned.
1936 static int ssh2_pkt_construct(Ssh ssh
, struct Packet
*pkt
)
1938 int cipherblk
, maclen
, padding
, i
;
1941 log_packet(ssh
->logctx
, PKT_OUTGOING
, pkt
->data
[5],
1942 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
, pkt
->data
[5]),
1943 pkt
->body
, pkt
->length
- (pkt
->body
- pkt
->data
),
1944 pkt
->nblanks
, pkt
->blanks
, &ssh
->v2_outgoing_sequence
);
1945 sfree(pkt
->blanks
); pkt
->blanks
= NULL
;
1949 * Compress packet payload.
1952 unsigned char *newpayload
;
1955 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, pkt
->data
+ 5,
1957 &newpayload
, &newlen
)) {
1959 ssh2_pkt_adddata(pkt
, newpayload
, newlen
);
1965 * Add padding. At least four bytes, and must also bring total
1966 * length (minus MAC) up to a multiple of the block size.
1967 * If pkt->forcepad is set, make sure the packet is at least that size
1970 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1971 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1973 if (pkt
->length
+ padding
< pkt
->forcepad
)
1974 padding
= pkt
->forcepad
- pkt
->length
;
1976 (cipherblk
- (pkt
->length
+ padding
) % cipherblk
) % cipherblk
;
1977 assert(padding
<= 255);
1978 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1979 ssh2_pkt_ensure(pkt
, pkt
->length
+ padding
+ maclen
);
1980 pkt
->data
[4] = padding
;
1981 for (i
= 0; i
< padding
; i
++)
1982 pkt
->data
[pkt
->length
+ i
] = random_byte();
1983 PUT_32BIT(pkt
->data
, pkt
->length
+ padding
- 4);
1985 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, pkt
->data
,
1986 pkt
->length
+ padding
,
1987 ssh
->v2_outgoing_sequence
);
1988 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1991 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1992 pkt
->data
, pkt
->length
+ padding
);
1994 pkt
->encrypted_len
= pkt
->length
+ padding
;
1996 /* Ready-to-send packet starts at pkt->data. We return length. */
1997 return pkt
->length
+ padding
+ maclen
;
2001 * Routines called from the main SSH code to send packets. There
2002 * are quite a few of these, because we have two separate
2003 * mechanisms for delaying the sending of packets:
2005 * - In order to send an IGNORE message and a password message in
2006 * a single fixed-length blob, we require the ability to
2007 * concatenate the encrypted forms of those two packets _into_ a
2008 * single blob and then pass it to our <network.h> transport
2009 * layer in one go. Hence, there's a deferment mechanism which
2010 * works after packet encryption.
2012 * - In order to avoid sending any connection-layer messages
2013 * during repeat key exchange, we have to queue up any such
2014 * outgoing messages _before_ they are encrypted (and in
2015 * particular before they're allocated sequence numbers), and
2016 * then send them once we've finished.
2018 * I call these mechanisms `defer' and `queue' respectively, so as
2019 * to distinguish them reasonably easily.
2021 * The functions send_noqueue() and defer_noqueue() free the packet
2022 * structure they are passed. Every outgoing packet goes through
2023 * precisely one of these functions in its life; packets passed to
2024 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
2025 * these or get queued, and then when the queue is later emptied
2026 * the packets are all passed to defer_noqueue().
2028 * When using a CBC-mode cipher, it's necessary to ensure that an
2029 * attacker can't provide data to be encrypted using an IV that they
2030 * know. We ensure this by prefixing each packet that might contain
2031 * user data with an SSH_MSG_IGNORE. This is done using the deferral
2032 * mechanism, so in this case send_noqueue() ends up redirecting to
2033 * defer_noqueue(). If you don't like this inefficiency, don't use
2037 static void ssh2_pkt_defer_noqueue(Ssh
, struct Packet
*, int);
2038 static void ssh_pkt_defersend(Ssh
);
2041 * Send an SSH-2 packet immediately, without queuing or deferring.
2043 static void ssh2_pkt_send_noqueue(Ssh ssh
, struct Packet
*pkt
)
2047 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
)) {
2048 /* We need to send two packets, so use the deferral mechanism. */
2049 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2050 ssh_pkt_defersend(ssh
);
2053 len
= ssh2_pkt_construct(ssh
, pkt
);
2054 backlog
= s_write(ssh
, pkt
->data
, len
);
2055 if (backlog
> SSH_MAX_BACKLOG
)
2056 ssh_throttle_all(ssh
, 1, backlog
);
2058 ssh
->outgoing_data_size
+= pkt
->encrypted_len
;
2059 if (!ssh
->kex_in_progress
&&
2060 ssh
->max_data_size
!= 0 &&
2061 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2062 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2064 ssh_free_packet(pkt
);
2068 * Defer an SSH-2 packet.
2070 static void ssh2_pkt_defer_noqueue(Ssh ssh
, struct Packet
*pkt
, int noignore
)
2073 if (ssh
->cscipher
!= NULL
&& (ssh
->cscipher
->flags
& SSH_CIPHER_IS_CBC
) &&
2074 ssh
->deferred_len
== 0 && !noignore
&&
2075 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2077 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
2078 * get encrypted with a known IV.
2080 struct Packet
*ipkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2081 ssh2_pkt_addstring_start(ipkt
);
2082 ssh2_pkt_defer_noqueue(ssh
, ipkt
, TRUE
);
2084 len
= ssh2_pkt_construct(ssh
, pkt
);
2085 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
2086 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
2087 ssh
->deferred_send_data
= sresize(ssh
->deferred_send_data
,
2091 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, pkt
->data
, len
);
2092 ssh
->deferred_len
+= len
;
2093 ssh
->deferred_data_size
+= pkt
->encrypted_len
;
2094 ssh_free_packet(pkt
);
2098 * Queue an SSH-2 packet.
2100 static void ssh2_pkt_queue(Ssh ssh
, struct Packet
*pkt
)
2102 assert(ssh
->queueing
);
2104 if (ssh
->queuelen
>= ssh
->queuesize
) {
2105 ssh
->queuesize
= ssh
->queuelen
+ 32;
2106 ssh
->queue
= sresize(ssh
->queue
, ssh
->queuesize
, struct Packet
*);
2109 ssh
->queue
[ssh
->queuelen
++] = pkt
;
2113 * Either queue or send a packet, depending on whether queueing is
2116 static void ssh2_pkt_send(Ssh ssh
, struct Packet
*pkt
)
2119 ssh2_pkt_queue(ssh
, pkt
);
2121 ssh2_pkt_send_noqueue(ssh
, pkt
);
2125 * Either queue or defer a packet, depending on whether queueing is
2128 static void ssh2_pkt_defer(Ssh ssh
, struct Packet
*pkt
)
2131 ssh2_pkt_queue(ssh
, pkt
);
2133 ssh2_pkt_defer_noqueue(ssh
, pkt
, FALSE
);
2137 * Send the whole deferred data block constructed by
2138 * ssh2_pkt_defer() or SSH-1's defer_packet().
2140 * The expected use of the defer mechanism is that you call
2141 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
2142 * not currently queueing, this simply sets up deferred_send_data
2143 * and then sends it. If we _are_ currently queueing, the calls to
2144 * ssh2_pkt_defer() put the deferred packets on to the queue
2145 * instead, and therefore ssh_pkt_defersend() has no deferred data
2146 * to send. Hence, there's no need to make it conditional on
2149 static void ssh_pkt_defersend(Ssh ssh
)
2152 backlog
= s_write(ssh
, ssh
->deferred_send_data
, ssh
->deferred_len
);
2153 ssh
->deferred_len
= ssh
->deferred_size
= 0;
2154 sfree(ssh
->deferred_send_data
);
2155 ssh
->deferred_send_data
= NULL
;
2156 if (backlog
> SSH_MAX_BACKLOG
)
2157 ssh_throttle_all(ssh
, 1, backlog
);
2159 ssh
->outgoing_data_size
+= ssh
->deferred_data_size
;
2160 if (!ssh
->kex_in_progress
&&
2161 ssh
->max_data_size
!= 0 &&
2162 ssh
->outgoing_data_size
> ssh
->max_data_size
)
2163 do_ssh2_transport(ssh
, "too much data sent", -1, NULL
);
2164 ssh
->deferred_data_size
= 0;
2168 * Send a packet whose length needs to be disguised (typically
2169 * passwords or keyboard-interactive responses).
2171 static void ssh2_pkt_send_with_padding(Ssh ssh
, struct Packet
*pkt
,
2177 * The simplest way to do this is to adjust the
2178 * variable-length padding field in the outgoing packet.
2180 * Currently compiled out, because some Cisco SSH servers
2181 * don't like excessively padded packets (bah, why's it
2184 pkt
->forcepad
= padsize
;
2185 ssh2_pkt_send(ssh
, pkt
);
2190 * If we can't do that, however, an alternative approach is
2191 * to use the pkt_defer mechanism to bundle the packet
2192 * tightly together with an SSH_MSG_IGNORE such that their
2193 * combined length is a constant. So first we construct the
2194 * final form of this packet and defer its sending.
2196 ssh2_pkt_defer(ssh
, pkt
);
2199 * Now construct an SSH_MSG_IGNORE which includes a string
2200 * that's an exact multiple of the cipher block size. (If
2201 * the cipher is NULL so that the block size is
2202 * unavailable, we don't do this trick at all, because we
2203 * gain nothing by it.)
2205 if (ssh
->cscipher
&&
2206 !(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
2209 stringlen
= (256 - ssh
->deferred_len
);
2210 stringlen
+= ssh
->cscipher
->blksize
- 1;
2211 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
2214 * Temporarily disable actual compression, so we
2215 * can guarantee to get this string exactly the
2216 * length we want it. The compression-disabling
2217 * routine should return an integer indicating how
2218 * many bytes we should adjust our string length
2222 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
2224 pkt
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
2225 ssh2_pkt_addstring_start(pkt
);
2226 for (i
= 0; i
< stringlen
; i
++) {
2227 char c
= (char) random_byte();
2228 ssh2_pkt_addstring_data(pkt
, &c
, 1);
2230 ssh2_pkt_defer(ssh
, pkt
);
2232 ssh_pkt_defersend(ssh
);
2237 * Send all queued SSH-2 packets. We send them by means of
2238 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2239 * packets that needed to be lumped together.
2241 static void ssh2_pkt_queuesend(Ssh ssh
)
2245 assert(!ssh
->queueing
);
2247 for (i
= 0; i
< ssh
->queuelen
; i
++)
2248 ssh2_pkt_defer_noqueue(ssh
, ssh
->queue
[i
], FALSE
);
2251 ssh_pkt_defersend(ssh
);
2255 void bndebug(char *string
, Bignum b
)
2259 p
= ssh2_mpint_fmt(b
, &len
);
2260 debug(("%s", string
));
2261 for (i
= 0; i
< len
; i
++)
2262 debug((" %02x", p
[i
]));
2268 static void hash_mpint(const struct ssh_hash
*h
, void *s
, Bignum b
)
2272 p
= ssh2_mpint_fmt(b
, &len
);
2273 hash_string(h
, s
, p
, len
);
2278 * Packet decode functions for both SSH-1 and SSH-2.
2280 static unsigned long ssh_pkt_getuint32(struct Packet
*pkt
)
2282 unsigned long value
;
2283 if (pkt
->length
- pkt
->savedpos
< 4)
2284 return 0; /* arrgh, no way to decline (FIXME?) */
2285 value
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2289 static int ssh2_pkt_getbool(struct Packet
*pkt
)
2291 unsigned long value
;
2292 if (pkt
->length
- pkt
->savedpos
< 1)
2293 return 0; /* arrgh, no way to decline (FIXME?) */
2294 value
= pkt
->body
[pkt
->savedpos
] != 0;
2298 static void ssh_pkt_getstring(struct Packet
*pkt
, char **p
, int *length
)
2303 if (pkt
->length
- pkt
->savedpos
< 4)
2305 len
= GET_32BIT(pkt
->body
+ pkt
->savedpos
);
2310 if (pkt
->length
- pkt
->savedpos
< *length
)
2312 *p
= (char *)(pkt
->body
+ pkt
->savedpos
);
2313 pkt
->savedpos
+= *length
;
2315 static void *ssh_pkt_getdata(struct Packet
*pkt
, int length
)
2317 if (pkt
->length
- pkt
->savedpos
< length
)
2319 pkt
->savedpos
+= length
;
2320 return pkt
->body
+ (pkt
->savedpos
- length
);
2322 static int ssh1_pkt_getrsakey(struct Packet
*pkt
, struct RSAKey
*key
,
2323 unsigned char **keystr
)
2327 j
= makekey(pkt
->body
+ pkt
->savedpos
,
2328 pkt
->length
- pkt
->savedpos
,
2335 assert(pkt
->savedpos
< pkt
->length
);
2339 static Bignum
ssh1_pkt_getmp(struct Packet
*pkt
)
2344 j
= ssh1_read_bignum(pkt
->body
+ pkt
->savedpos
,
2345 pkt
->length
- pkt
->savedpos
, &b
);
2353 static Bignum
ssh2_pkt_getmp(struct Packet
*pkt
)
2359 ssh_pkt_getstring(pkt
, &p
, &length
);
2364 b
= bignum_from_bytes((unsigned char *)p
, length
);
2369 * Helper function to add an SSH-2 signature blob to a packet.
2370 * Expects to be shown the public key blob as well as the signature
2371 * blob. Normally works just like ssh2_pkt_addstring, but will
2372 * fiddle with the signature packet if necessary for
2373 * BUG_SSH2_RSA_PADDING.
2375 static void ssh2_add_sigblob(Ssh ssh
, struct Packet
*pkt
,
2376 void *pkblob_v
, int pkblob_len
,
2377 void *sigblob_v
, int sigblob_len
)
2379 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
2380 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
2382 /* dmemdump(pkblob, pkblob_len); */
2383 /* dmemdump(sigblob, sigblob_len); */
2386 * See if this is in fact an ssh-rsa signature and a buggy
2387 * server; otherwise we can just do this the easy way.
2389 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
2390 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
2391 int pos
, len
, siglen
;
2394 * Find the byte length of the modulus.
2397 pos
= 4+7; /* skip over "ssh-rsa" */
2398 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
2399 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
2400 pos
+= 4; /* find modulus itself */
2401 while (len
> 0 && pkblob
[pos
] == 0)
2403 /* debug(("modulus length is %d\n", len)); */
2406 * Now find the signature integer.
2408 pos
= 4+7; /* skip over "ssh-rsa" */
2409 siglen
= GET_32BIT(sigblob
+pos
);
2410 /* debug(("signature length is %d\n", siglen)); */
2412 if (len
!= siglen
) {
2413 unsigned char newlen
[4];
2414 ssh2_pkt_addstring_start(pkt
);
2415 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, pos
);
2416 /* dmemdump(sigblob, pos); */
2417 pos
+= 4; /* point to start of actual sig */
2418 PUT_32BIT(newlen
, len
);
2419 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 4);
2420 /* dmemdump(newlen, 4); */
2422 while (len
-- > siglen
) {
2423 ssh2_pkt_addstring_data(pkt
, (char *)newlen
, 1);
2424 /* dmemdump(newlen, 1); */
2426 ssh2_pkt_addstring_data(pkt
, (char *)(sigblob
+pos
), siglen
);
2427 /* dmemdump(sigblob+pos, siglen); */
2431 /* Otherwise fall through and do it the easy way. */
2434 ssh2_pkt_addstring_start(pkt
);
2435 ssh2_pkt_addstring_data(pkt
, (char *)sigblob
, sigblob_len
);
2439 * Examine the remote side's version string and compare it against
2440 * a list of known buggy implementations.
2442 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
2444 char *imp
; /* pointer to implementation part */
2446 imp
+= strcspn(imp
, "-");
2448 imp
+= strcspn(imp
, "-");
2451 ssh
->remote_bugs
= 0;
2454 * General notes on server version strings:
2455 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2456 * here -- in particular, we've heard of one that's perfectly happy
2457 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2458 * so we can't distinguish them.
2460 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == FORCE_ON
||
2461 (conf_get_int(ssh
->conf
, CONF_sshbug_ignore1
) == AUTO
&&
2462 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
2463 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
2464 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25") ||
2465 !strcmp(imp
, "OSU_1.4alpha3") || !strcmp(imp
, "OSU_1.5alpha4")))) {
2467 * These versions don't support SSH1_MSG_IGNORE, so we have
2468 * to use a different defence against password length
2471 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
2472 logevent("We believe remote version has SSH-1 ignore bug");
2475 if (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == FORCE_ON
||
2476 (conf_get_int(ssh
->conf
, CONF_sshbug_plainpw1
) == AUTO
&&
2477 (!strcmp(imp
, "Cisco-1.25") || !strcmp(imp
, "OSU_1.4alpha3")))) {
2479 * These versions need a plain password sent; they can't
2480 * handle having a null and a random length of data after
2483 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
2484 logevent("We believe remote version needs a plain SSH-1 password");
2487 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == FORCE_ON
||
2488 (conf_get_int(ssh
->conf
, CONF_sshbug_rsa1
) == AUTO
&&
2489 (!strcmp(imp
, "Cisco-1.25")))) {
2491 * These versions apparently have no clue whatever about
2492 * RSA authentication and will panic and die if they see
2493 * an AUTH_RSA message.
2495 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
2496 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2499 if (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == FORCE_ON
||
2500 (conf_get_int(ssh
->conf
, CONF_sshbug_hmac2
) == AUTO
&&
2501 !wc_match("* VShell", imp
) &&
2502 (wc_match("2.1.0*", imp
) || wc_match("2.0.*", imp
) ||
2503 wc_match("2.2.0*", imp
) || wc_match("2.3.0*", imp
) ||
2504 wc_match("2.1 *", imp
)))) {
2506 * These versions have the HMAC bug.
2508 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
2509 logevent("We believe remote version has SSH-2 HMAC bug");
2512 if (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == FORCE_ON
||
2513 (conf_get_int(ssh
->conf
, CONF_sshbug_derivekey2
) == AUTO
&&
2514 !wc_match("* VShell", imp
) &&
2515 (wc_match("2.0.0*", imp
) || wc_match("2.0.10*", imp
) ))) {
2517 * These versions have the key-derivation bug (failing to
2518 * include the literal shared secret in the hashes that
2519 * generate the keys).
2521 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
2522 logevent("We believe remote version has SSH-2 key-derivation bug");
2525 if (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == FORCE_ON
||
2526 (conf_get_int(ssh
->conf
, CONF_sshbug_rsapad2
) == AUTO
&&
2527 (wc_match("OpenSSH_2.[5-9]*", imp
) ||
2528 wc_match("OpenSSH_3.[0-2]*", imp
)))) {
2530 * These versions have the SSH-2 RSA padding bug.
2532 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
2533 logevent("We believe remote version has SSH-2 RSA padding bug");
2536 if (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == FORCE_ON
||
2537 (conf_get_int(ssh
->conf
, CONF_sshbug_pksessid2
) == AUTO
&&
2538 wc_match("OpenSSH_2.[0-2]*", imp
))) {
2540 * These versions have the SSH-2 session-ID bug in
2541 * public-key authentication.
2543 ssh
->remote_bugs
|= BUG_SSH2_PK_SESSIONID
;
2544 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2547 if (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == FORCE_ON
||
2548 (conf_get_int(ssh
->conf
, CONF_sshbug_rekey2
) == AUTO
&&
2549 (wc_match("DigiSSH_2.0", imp
) ||
2550 wc_match("OpenSSH_2.[0-4]*", imp
) ||
2551 wc_match("OpenSSH_2.5.[0-3]*", imp
) ||
2552 wc_match("Sun_SSH_1.0", imp
) ||
2553 wc_match("Sun_SSH_1.0.1", imp
) ||
2554 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2555 wc_match("WeOnlyDo-*", imp
)))) {
2557 * These versions have the SSH-2 rekey bug.
2559 ssh
->remote_bugs
|= BUG_SSH2_REKEY
;
2560 logevent("We believe remote version has SSH-2 rekey bug");
2563 if (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == FORCE_ON
||
2564 (conf_get_int(ssh
->conf
, CONF_sshbug_maxpkt2
) == AUTO
&&
2565 (wc_match("1.36_sshlib GlobalSCAPE", imp
) ||
2566 wc_match("1.36 sshlib: GlobalScape", imp
)))) {
2568 * This version ignores our makpkt and needs to be throttled.
2570 ssh
->remote_bugs
|= BUG_SSH2_MAXPKT
;
2571 logevent("We believe remote version ignores SSH-2 maximum packet size");
2574 if (conf_get_int(ssh
->conf
, CONF_sshbug_ignore2
) == FORCE_ON
) {
2576 * Servers that don't support SSH2_MSG_IGNORE. Currently,
2577 * none detected automatically.
2579 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH2_IGNORE
;
2580 logevent("We believe remote version has SSH-2 ignore bug");
2583 if (conf_get_int(ssh
->conf
, CONF_sshbug_winadj
) == FORCE_ON
) {
2585 * Servers that don't support our winadj request for one
2586 * reason or another. Currently, none detected automatically.
2588 ssh
->remote_bugs
|= BUG_CHOKES_ON_WINADJ
;
2589 logevent("We believe remote version has winadj bug");
2594 * The `software version' part of an SSH version string is required
2595 * to contain no spaces or minus signs.
2597 static void ssh_fix_verstring(char *str
)
2599 /* Eat "SSH-<protoversion>-". */
2600 assert(*str
== 'S'); str
++;
2601 assert(*str
== 'S'); str
++;
2602 assert(*str
== 'H'); str
++;
2603 assert(*str
== '-'); str
++;
2604 while (*str
&& *str
!= '-') str
++;
2605 assert(*str
== '-'); str
++;
2607 /* Convert minus signs and spaces in the remaining string into
2610 if (*str
== '-' || *str
== ' ')
2617 * Send an appropriate SSH version string.
2619 static void ssh_send_verstring(Ssh ssh
, char *svers
)
2623 if (ssh
->version
== 2) {
2625 * Construct a v2 version string.
2627 verstring
= dupprintf("SSH-2.0-%s\015\012", sshver
);
2630 * Construct a v1 version string.
2632 verstring
= dupprintf("SSH-%s-%s\012",
2633 (ssh_versioncmp(svers
, "1.5") <= 0 ?
2638 ssh_fix_verstring(verstring
);
2640 if (ssh
->version
== 2) {
2643 * Record our version string.
2645 len
= strcspn(verstring
, "\015\012");
2646 ssh
->v_c
= snewn(len
+ 1, char);
2647 memcpy(ssh
->v_c
, verstring
, len
);
2651 logeventf(ssh
, "We claim version: %.*s",
2652 strcspn(verstring
, "\015\012"), verstring
);
2653 s_write(ssh
, verstring
, strlen(verstring
));
2657 static int do_ssh_init(Ssh ssh
, unsigned char c
)
2659 struct do_ssh_init_state
{
2668 crState(do_ssh_init_state
);
2672 /* Search for a line beginning with the string "SSH-" in the input. */
2674 if (c
!= 'S') goto no
;
2676 if (c
!= 'S') goto no
;
2678 if (c
!= 'H') goto no
;
2680 if (c
!= '-') goto no
;
2689 s
->vstring
= snewn(s
->vstrsize
, char);
2690 strcpy(s
->vstring
, "SSH-");
2694 crReturn(1); /* get another char */
2695 if (s
->vslen
>= s
->vstrsize
- 1) {
2697 s
->vstring
= sresize(s
->vstring
, s
->vstrsize
, char);
2699 s
->vstring
[s
->vslen
++] = c
;
2702 s
->version
[s
->i
] = '\0';
2704 } else if (s
->i
< sizeof(s
->version
) - 1)
2705 s
->version
[s
->i
++] = c
;
2706 } else if (c
== '\012')
2710 ssh
->agentfwd_enabled
= FALSE
;
2711 ssh
->rdpkt2_state
.incoming_sequence
= 0;
2713 s
->vstring
[s
->vslen
] = 0;
2714 s
->vstring
[strcspn(s
->vstring
, "\015\012")] = '\0';/* remove EOL chars */
2715 logeventf(ssh
, "Server version: %s", s
->vstring
);
2716 ssh_detect_bugs(ssh
, s
->vstring
);
2719 * Decide which SSH protocol version to support.
2722 /* Anything strictly below "2.0" means protocol 1 is supported. */
2723 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
2724 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2725 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
2727 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 0 && !s
->proto1
) {
2728 bombout(("SSH protocol version 1 required by user but not provided by server"));
2731 if (conf_get_int(ssh
->conf
, CONF_sshprot
) == 3 && !s
->proto2
) {
2732 bombout(("SSH protocol version 2 required by user but not provided by server"));
2736 if (s
->proto2
&& (conf_get_int(ssh
->conf
, CONF_sshprot
) >= 2 || !s
->proto1
))
2741 logeventf(ssh
, "Using SSH protocol version %d", ssh
->version
);
2743 /* Send the version string, if we haven't already */
2744 if (conf_get_int(ssh
->conf
, CONF_sshprot
) != 3)
2745 ssh_send_verstring(ssh
, s
->version
);
2747 if (ssh
->version
== 2) {
2750 * Record their version string.
2752 len
= strcspn(s
->vstring
, "\015\012");
2753 ssh
->v_s
= snewn(len
+ 1, char);
2754 memcpy(ssh
->v_s
, s
->vstring
, len
);
2758 * Initialise SSH-2 protocol.
2760 ssh
->protocol
= ssh2_protocol
;
2761 ssh2_protocol_setup(ssh
);
2762 ssh
->s_rdpkt
= ssh2_rdpkt
;
2765 * Initialise SSH-1 protocol.
2767 ssh
->protocol
= ssh1_protocol
;
2768 ssh1_protocol_setup(ssh
);
2769 ssh
->s_rdpkt
= ssh1_rdpkt
;
2771 if (ssh
->version
== 2)
2772 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
2774 update_specials_menu(ssh
->frontend
);
2775 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
2776 ssh
->pinger
= pinger_new(ssh
->conf
, &ssh_backend
, ssh
);
2783 static void ssh_process_incoming_data(Ssh ssh
,
2784 unsigned char **data
, int *datalen
)
2786 struct Packet
*pktin
;
2788 pktin
= ssh
->s_rdpkt(ssh
, data
, datalen
);
2790 ssh
->protocol(ssh
, NULL
, 0, pktin
);
2791 ssh_free_packet(pktin
);
2795 static void ssh_queue_incoming_data(Ssh ssh
,
2796 unsigned char **data
, int *datalen
)
2798 bufchain_add(&ssh
->queued_incoming_data
, *data
, *datalen
);
2803 static void ssh_process_queued_incoming_data(Ssh ssh
)
2806 unsigned char *data
;
2809 while (!ssh
->frozen
&& bufchain_size(&ssh
->queued_incoming_data
)) {
2810 bufchain_prefix(&ssh
->queued_incoming_data
, &vdata
, &len
);
2814 while (!ssh
->frozen
&& len
> 0)
2815 ssh_process_incoming_data(ssh
, &data
, &len
);
2818 bufchain_consume(&ssh
->queued_incoming_data
, origlen
- len
);
2822 static void ssh_set_frozen(Ssh ssh
, int frozen
)
2825 sk_set_frozen(ssh
->s
, frozen
);
2826 ssh
->frozen
= frozen
;
2829 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
2831 /* Log raw data, if we're in that mode. */
2833 log_packet(ssh
->logctx
, PKT_INCOMING
, -1, NULL
, data
, datalen
,
2836 crBegin(ssh
->ssh_gotdata_crstate
);
2839 * To begin with, feed the characters one by one to the
2840 * protocol initialisation / selection function do_ssh_init().
2841 * When that returns 0, we're done with the initial greeting
2842 * exchange and can move on to packet discipline.
2845 int ret
; /* need not be kept across crReturn */
2847 crReturnV
; /* more data please */
2848 ret
= do_ssh_init(ssh
, *data
);
2856 * We emerge from that loop when the initial negotiation is
2857 * over and we have selected an s_rdpkt function. Now pass
2858 * everything to s_rdpkt, and then pass the resulting packets
2859 * to the proper protocol handler.
2863 while (bufchain_size(&ssh
->queued_incoming_data
) > 0 || datalen
> 0) {
2865 ssh_queue_incoming_data(ssh
, &data
, &datalen
);
2866 /* This uses up all data and cannot cause anything interesting
2867 * to happen; indeed, for anything to happen at all, we must
2868 * return, so break out. */
2870 } else if (bufchain_size(&ssh
->queued_incoming_data
) > 0) {
2871 /* This uses up some or all data, and may freeze the
2873 ssh_process_queued_incoming_data(ssh
);
2875 /* This uses up some or all data, and may freeze the
2877 ssh_process_incoming_data(ssh
, &data
, &datalen
);
2879 /* FIXME this is probably EBW. */
2880 if (ssh
->state
== SSH_STATE_CLOSED
)
2883 /* We're out of data. Go and get some more. */
2889 static int ssh_do_close(Ssh ssh
, int notify_exit
)
2892 struct ssh_channel
*c
;
2894 ssh
->state
= SSH_STATE_CLOSED
;
2895 expire_timer_context(ssh
);
2900 notify_remote_exit(ssh
->frontend
);
2905 * Now we must shut down any port- and X-forwarded channels going
2906 * through this connection.
2908 if (ssh
->channels
) {
2909 while (NULL
!= (c
= index234(ssh
->channels
, 0))) {
2912 x11_close(c
->u
.x11
.s
);
2915 case CHAN_SOCKDATA_DORMANT
:
2916 pfd_close(c
->u
.pfd
.s
);
2919 del234(ssh
->channels
, c
); /* moving next one to index 0 */
2920 if (ssh
->version
== 2)
2921 bufchain_clear(&c
->v
.v2
.outbuffer
);
2926 * Go through port-forwardings, and close any associated
2927 * listening sockets.
2929 if (ssh
->portfwds
) {
2930 struct ssh_portfwd
*pf
;
2931 while (NULL
!= (pf
= index234(ssh
->portfwds
, 0))) {
2932 /* Dispose of any listening socket. */
2934 pfd_terminate(pf
->local
);
2935 del234(ssh
->portfwds
, pf
); /* moving next one to index 0 */
2938 freetree234(ssh
->portfwds
);
2939 ssh
->portfwds
= NULL
;
2945 static void ssh_log(Plug plug
, int type
, SockAddr addr
, int port
,
2946 const char *error_msg
, int error_code
)
2948 Ssh ssh
= (Ssh
) plug
;
2949 char addrbuf
[256], *msg
;
2951 sk_getaddr(addr
, addrbuf
, lenof(addrbuf
));
2954 msg
= dupprintf("Connecting to %s port %d", addrbuf
, port
);
2956 msg
= dupprintf("Failed to connect to %s: %s", addrbuf
, error_msg
);
2962 static int ssh_closing(Plug plug
, const char *error_msg
, int error_code
,
2965 Ssh ssh
= (Ssh
) plug
;
2966 int need_notify
= ssh_do_close(ssh
, FALSE
);
2969 if (!ssh
->close_expected
)
2970 error_msg
= "Server unexpectedly closed network connection";
2972 error_msg
= "Server closed network connection";
2975 if (ssh
->close_expected
&& ssh
->clean_exit
&& ssh
->exitcode
< 0)
2979 notify_remote_exit(ssh
->frontend
);
2982 logevent(error_msg
);
2983 if (!ssh
->close_expected
|| !ssh
->clean_exit
)
2984 connection_fatal(ssh
->frontend
, "%s", error_msg
);
2988 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2990 Ssh ssh
= (Ssh
) plug
;
2991 ssh_gotdata(ssh
, (unsigned char *)data
, len
);
2992 if (ssh
->state
== SSH_STATE_CLOSED
) {
2993 ssh_do_close(ssh
, TRUE
);
2999 static void ssh_sent(Plug plug
, int bufsize
)
3001 Ssh ssh
= (Ssh
) plug
;
3003 * If the send backlog on the SSH socket itself clears, we
3004 * should unthrottle the whole world if it was throttled.
3006 if (bufsize
< SSH_MAX_BACKLOG
)
3007 ssh_throttle_all(ssh
, 0, bufsize
);
3011 * Connect to specified host and port.
3012 * Returns an error message, or NULL on success.
3013 * Also places the canonical host name into `realhost'. It must be
3014 * freed by the caller.
3016 static const char *connect_to_host(Ssh ssh
, char *host
, int port
,
3017 char **realhost
, int nodelay
, int keepalive
)
3019 static const struct plug_function_table fn_table
= {
3030 int addressfamily
, sshprot
;
3032 loghost
= conf_get_str(ssh
->conf
, CONF_loghost
);
3036 ssh
->savedhost
= dupstr(loghost
);
3037 ssh
->savedport
= 22; /* default ssh port */
3040 * A colon suffix on savedhost also lets us affect
3043 * (FIXME: do something about IPv6 address literals here.)
3045 colon
= strrchr(ssh
->savedhost
, ':');
3049 ssh
->savedport
= atoi(colon
);
3052 ssh
->savedhost
= dupstr(host
);
3054 port
= 22; /* default ssh port */
3055 ssh
->savedport
= port
;
3061 addressfamily
= conf_get_int(ssh
->conf
, CONF_addressfamily
);
3062 logeventf(ssh
, "Looking up host \"%s\"%s", host
,
3063 (addressfamily
== ADDRTYPE_IPV4 ?
" (IPv4)" :
3064 (addressfamily
== ADDRTYPE_IPV6 ?
" (IPv6)" : "")));
3065 addr
= name_lookup(host
, port
, realhost
, ssh
->conf
, addressfamily
);
3066 if ((err
= sk_addr_error(addr
)) != NULL
) {
3070 ssh
->fullhostname
= dupstr(*realhost
); /* save in case of GSSAPI */
3075 ssh
->fn
= &fn_table
;
3076 ssh
->s
= new_connection(addr
, *realhost
, port
,
3077 0, 1, nodelay
, keepalive
, (Plug
) ssh
, ssh
->conf
);
3078 if ((err
= sk_socket_error(ssh
->s
)) != NULL
) {
3080 notify_remote_exit(ssh
->frontend
);
3085 * If the SSH version number's fixed, set it now, and if it's SSH-2,
3086 * send the version string too.
3088 sshprot
= conf_get_int(ssh
->conf
, CONF_sshprot
);
3093 ssh_send_verstring(ssh
, NULL
);
3097 * loghost, if configured, overrides realhost.
3101 *realhost
= dupstr(loghost
);
3108 * Throttle or unthrottle the SSH connection.
3110 static void ssh_throttle_conn(Ssh ssh
, int adjust
)
3112 int old_count
= ssh
->conn_throttle_count
;
3113 ssh
->conn_throttle_count
+= adjust
;
3114 assert(ssh
->conn_throttle_count
>= 0);
3115 if (ssh
->conn_throttle_count
&& !old_count
) {
3116 ssh_set_frozen(ssh
, 1);
3117 } else if (!ssh
->conn_throttle_count
&& old_count
) {
3118 ssh_set_frozen(ssh
, 0);
3123 * Throttle or unthrottle _all_ local data streams (for when sends
3124 * on the SSH connection itself back up).
3126 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
3129 struct ssh_channel
*c
;
3131 if (enable
== ssh
->throttled_all
)
3133 ssh
->throttled_all
= enable
;
3134 ssh
->overall_bufsize
= bufsize
;
3137 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
3139 case CHAN_MAINSESSION
:
3141 * This is treated separately, outside the switch.
3145 x11_override_throttle(c
->u
.x11
.s
, enable
);
3148 /* Agent channels require no buffer management. */
3151 pfd_override_throttle(c
->u
.pfd
.s
, enable
);
3157 static void ssh_agent_callback(void *sshv
, void *reply
, int replylen
)
3159 Ssh ssh
= (Ssh
) sshv
;
3161 ssh
->agent_response
= reply
;
3162 ssh
->agent_response_len
= replylen
;
3164 if (ssh
->version
== 1)
3165 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3167 do_ssh2_authconn(ssh
, NULL
, -1, NULL
);
3170 static void ssh_dialog_callback(void *sshv
, int ret
)
3172 Ssh ssh
= (Ssh
) sshv
;
3174 ssh
->user_response
= ret
;
3176 if (ssh
->version
== 1)
3177 do_ssh1_login(ssh
, NULL
, -1, NULL
);
3179 do_ssh2_transport(ssh
, NULL
, -1, NULL
);
3182 * This may have unfrozen the SSH connection, so do a
3185 ssh_process_queued_incoming_data(ssh
);
3188 static void ssh_agentf_callback(void *cv
, void *reply
, int replylen
)
3190 struct ssh_channel
*c
= (struct ssh_channel
*)cv
;
3192 void *sentreply
= reply
;
3195 /* Fake SSH_AGENT_FAILURE. */
3196 sentreply
= "\0\0\0\1\5";
3199 if (ssh
->version
== 2) {
3200 ssh2_add_channel_data(c
, sentreply
, replylen
);
3203 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3204 PKT_INT
, c
->remoteid
,
3207 PKT_DATA
, sentreply
, replylen
,
3216 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
3217 * non-NULL, otherwise just close the connection. `client_reason' == NULL
3218 * => log `wire_reason'.
3220 static void ssh_disconnect(Ssh ssh
, char *client_reason
, char *wire_reason
,
3221 int code
, int clean_exit
)
3225 client_reason
= wire_reason
;
3227 error
= dupprintf("Disconnected: %s", client_reason
);
3229 error
= dupstr("Disconnected");
3231 if (ssh
->version
== 1) {
3232 send_packet(ssh
, SSH1_MSG_DISCONNECT
, PKT_STR
, wire_reason
,
3234 } else if (ssh
->version
== 2) {
3235 struct Packet
*pktout
= ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3236 ssh2_pkt_adduint32(pktout
, code
);
3237 ssh2_pkt_addstring(pktout
, wire_reason
);
3238 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
3239 ssh2_pkt_send_noqueue(ssh
, pktout
);
3242 ssh
->close_expected
= TRUE
;
3243 ssh
->clean_exit
= clean_exit
;
3244 ssh_closing((Plug
)ssh
, error
, 0, 0);
3249 * Handle the key exchange and user authentication phases.
3251 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
,
3252 struct Packet
*pktin
)
3255 unsigned char cookie
[8], *ptr
;
3256 struct RSAKey servkey
, hostkey
;
3257 struct MD5Context md5c
;
3258 struct do_ssh1_login_state
{
3261 unsigned char *rsabuf
, *keystr1
, *keystr2
;
3262 unsigned long supported_ciphers_mask
, supported_auths_mask
;
3263 int tried_publickey
, tried_agent
;
3264 int tis_auth_refused
, ccard_auth_refused
;
3265 unsigned char session_id
[16];
3267 void *publickey_blob
;
3268 int publickey_bloblen
;
3269 char *publickey_comment
;
3270 int publickey_encrypted
;
3271 prompts_t
*cur_prompt
;
3274 unsigned char request
[5], *response
, *p
;
3285 crState(do_ssh1_login_state
);
3292 if (pktin
->type
!= SSH1_SMSG_PUBLIC_KEY
) {
3293 bombout(("Public key packet not received"));
3297 logevent("Received public keys");
3299 ptr
= ssh_pkt_getdata(pktin
, 8);
3301 bombout(("SSH-1 public key packet stopped before random cookie"));
3304 memcpy(cookie
, ptr
, 8);
3306 if (!ssh1_pkt_getrsakey(pktin
, &servkey
, &s
->keystr1
) ||
3307 !ssh1_pkt_getrsakey(pktin
, &hostkey
, &s
->keystr2
)) {
3308 bombout(("Failed to read SSH-1 public keys from public key packet"));
3313 * Log the host key fingerprint.
3317 logevent("Host key fingerprint is:");
3318 strcpy(logmsg
, " ");
3319 hostkey
.comment
= NULL
;
3320 rsa_fingerprint(logmsg
+ strlen(logmsg
),
3321 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
3325 ssh
->v1_remote_protoflags
= ssh_pkt_getuint32(pktin
);
3326 s
->supported_ciphers_mask
= ssh_pkt_getuint32(pktin
);
3327 s
->supported_auths_mask
= ssh_pkt_getuint32(pktin
);
3328 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
))
3329 s
->supported_auths_mask
&= ~(1 << SSH1_AUTH_RSA
);
3331 ssh
->v1_local_protoflags
=
3332 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
3333 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
3336 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
3337 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
3338 MD5Update(&md5c
, cookie
, 8);
3339 MD5Final(s
->session_id
, &md5c
);
3341 for (i
= 0; i
< 32; i
++)
3342 ssh
->session_key
[i
] = random_byte();
3345 * Verify that the `bits' and `bytes' parameters match.
3347 if (hostkey
.bits
> hostkey
.bytes
* 8 ||
3348 servkey
.bits
> servkey
.bytes
* 8) {
3349 bombout(("SSH-1 public keys were badly formatted"));
3353 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
3355 s
->rsabuf
= snewn(s
->len
, unsigned char);
3358 * Verify the host key.
3362 * First format the key into a string.
3364 int len
= rsastr_len(&hostkey
);
3365 char fingerprint
[100];
3366 char *keystr
= snewn(len
, char);
3367 rsastr_fmt(keystr
, &hostkey
);
3368 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
3370 ssh_set_frozen(ssh
, 1);
3371 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
3372 ssh
->savedhost
, ssh
->savedport
,
3373 "rsa", keystr
, fingerprint
,
3374 ssh_dialog_callback
, ssh
);
3376 if (s
->dlgret
< 0) {
3380 bombout(("Unexpected data from server while waiting"
3381 " for user host key response"));
3384 } while (pktin
|| inlen
> 0);
3385 s
->dlgret
= ssh
->user_response
;
3387 ssh_set_frozen(ssh
, 0);
3389 if (s
->dlgret
== 0) {
3390 ssh_disconnect(ssh
, "User aborted at host key verification",
3396 for (i
= 0; i
< 32; i
++) {
3397 s
->rsabuf
[i
] = ssh
->session_key
[i
];
3399 s
->rsabuf
[i
] ^= s
->session_id
[i
];
3402 if (hostkey
.bytes
> servkey
.bytes
) {
3403 ret
= rsaencrypt(s
->rsabuf
, 32, &servkey
);
3405 ret
= rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
3407 ret
= rsaencrypt(s
->rsabuf
, 32, &hostkey
);
3409 ret
= rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
3412 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3416 logevent("Encrypted session key");
3419 int cipher_chosen
= 0, warn
= 0;
3420 char *cipher_string
= NULL
;
3422 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
3423 int next_cipher
= conf_get_int_int(ssh
->conf
,
3424 CONF_ssh_cipherlist
, i
);
3425 if (next_cipher
== CIPHER_WARN
) {
3426 /* If/when we choose a cipher, warn about it */
3428 } else if (next_cipher
== CIPHER_AES
) {
3429 /* XXX Probably don't need to mention this. */
3430 logevent("AES not supported in SSH-1, skipping");
3432 switch (next_cipher
) {
3433 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
3434 cipher_string
= "3DES"; break;
3435 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
3436 cipher_string
= "Blowfish"; break;
3437 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
3438 cipher_string
= "single-DES"; break;
3440 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
3444 if (!cipher_chosen
) {
3445 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
3446 bombout(("Server violates SSH-1 protocol by not "
3447 "supporting 3DES encryption"));
3449 /* shouldn't happen */
3450 bombout(("No supported ciphers found"));
3454 /* Warn about chosen cipher if necessary. */
3456 ssh_set_frozen(ssh
, 1);
3457 s
->dlgret
= askalg(ssh
->frontend
, "cipher", cipher_string
,
3458 ssh_dialog_callback
, ssh
);
3459 if (s
->dlgret
< 0) {
3463 bombout(("Unexpected data from server while waiting"
3464 " for user response"));
3467 } while (pktin
|| inlen
> 0);
3468 s
->dlgret
= ssh
->user_response
;
3470 ssh_set_frozen(ssh
, 0);
3471 if (s
->dlgret
== 0) {
3472 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
3479 switch (s
->cipher_type
) {
3480 case SSH_CIPHER_3DES
:
3481 logevent("Using 3DES encryption");
3483 case SSH_CIPHER_DES
:
3484 logevent("Using single-DES encryption");
3486 case SSH_CIPHER_BLOWFISH
:
3487 logevent("Using Blowfish encryption");
3491 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
3492 PKT_CHAR
, s
->cipher_type
,
3493 PKT_DATA
, cookie
, 8,
3494 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
3495 PKT_DATA
, s
->rsabuf
, s
->len
,
3496 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
3498 logevent("Trying to enable encryption...");
3502 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
3503 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
3505 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
3506 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
3507 logeventf(ssh
, "Initialised %s encryption", ssh
->cipher
->text_name
);
3509 ssh
->crcda_ctx
= crcda_make_context();
3510 logevent("Installing CRC compensation attack detector");
3512 if (servkey
.modulus
) {
3513 sfree(servkey
.modulus
);
3514 servkey
.modulus
= NULL
;
3516 if (servkey
.exponent
) {
3517 sfree(servkey
.exponent
);
3518 servkey
.exponent
= NULL
;
3520 if (hostkey
.modulus
) {
3521 sfree(hostkey
.modulus
);
3522 hostkey
.modulus
= NULL
;
3524 if (hostkey
.exponent
) {
3525 sfree(hostkey
.exponent
);
3526 hostkey
.exponent
= NULL
;
3530 if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3531 bombout(("Encryption not successfully enabled"));
3535 logevent("Successfully started encryption");
3537 fflush(stdout
); /* FIXME eh? */
3539 if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
3540 int ret
; /* need not be kept over crReturn */
3541 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3542 s
->cur_prompt
->to_server
= TRUE
;
3543 s
->cur_prompt
->name
= dupstr("SSH login name");
3544 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
3545 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3548 crWaitUntil(!pktin
);
3549 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3554 * Failed to get a username. Terminate.
3556 free_prompts(s
->cur_prompt
);
3557 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
3560 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3561 free_prompts(s
->cur_prompt
);
3564 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, ssh
->username
, PKT_END
);
3566 char *userlog
= dupprintf("Sent username \"%s\"", ssh
->username
);
3568 if (flags
& FLAG_INTERACTIVE
&&
3569 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
3570 c_write_str(ssh
, userlog
);
3571 c_write_str(ssh
, "\r\n");
3579 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_RSA
)) == 0) {
3580 /* We must not attempt PK auth. Pretend we've already tried it. */
3581 s
->tried_publickey
= s
->tried_agent
= 1;
3583 s
->tried_publickey
= s
->tried_agent
= 0;
3585 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
3587 * Load the public half of any configured keyfile for later use.
3589 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3590 if (!filename_is_null(s
->keyfile
)) {
3592 logeventf(ssh
, "Reading private key file \"%.150s\"",
3593 filename_to_str(s
->keyfile
));
3594 keytype
= key_type(s
->keyfile
);
3595 if (keytype
== SSH_KEYTYPE_SSH1
) {
3597 if (rsakey_pubblob(s
->keyfile
,
3598 &s
->publickey_blob
, &s
->publickey_bloblen
,
3599 &s
->publickey_comment
, &error
)) {
3600 s
->publickey_encrypted
= rsakey_encrypted(s
->keyfile
,
3604 logeventf(ssh
, "Unable to load private key (%s)", error
);
3605 msgbuf
= dupprintf("Unable to load private key file "
3606 "\"%.150s\" (%s)\r\n",
3607 filename_to_str(s
->keyfile
),
3609 c_write_str(ssh
, msgbuf
);
3611 s
->publickey_blob
= NULL
;
3615 logeventf(ssh
, "Unable to use this key file (%s)",
3616 key_type_to_str(keytype
));
3617 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
3619 filename_to_str(s
->keyfile
),
3620 key_type_to_str(keytype
));
3621 c_write_str(ssh
, msgbuf
);
3623 s
->publickey_blob
= NULL
;
3626 s
->publickey_blob
= NULL
;
3628 while (pktin
->type
== SSH1_SMSG_FAILURE
) {
3629 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
3631 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists() && !s
->tried_agent
) {
3633 * Attempt RSA authentication using Pageant.
3639 logevent("Pageant is running. Requesting keys.");
3641 /* Request the keys held by the agent. */
3642 PUT_32BIT(s
->request
, 1);
3643 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
3644 if (!agent_query(s
->request
, 5, &r
, &s
->responselen
,
3645 ssh_agent_callback
, ssh
)) {
3649 bombout(("Unexpected data from server while waiting"
3650 " for agent response"));
3653 } while (pktin
|| inlen
> 0);
3654 r
= ssh
->agent_response
;
3655 s
->responselen
= ssh
->agent_response_len
;
3657 s
->response
= (unsigned char *) r
;
3658 if (s
->response
&& s
->responselen
>= 5 &&
3659 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
3660 s
->p
= s
->response
+ 5;
3661 s
->nkeys
= GET_32BIT(s
->p
);
3663 logeventf(ssh
, "Pageant has %d SSH-1 keys", s
->nkeys
);
3664 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
3665 unsigned char *pkblob
= s
->p
;
3669 do { /* do while (0) to make breaking easy */
3670 n
= ssh1_read_bignum
3671 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3676 n
= ssh1_read_bignum
3677 (s
->p
, s
->responselen
-(s
->p
-s
->response
),
3682 if (s
->responselen
- (s
->p
-s
->response
) < 4)
3684 s
->commentlen
= GET_32BIT(s
->p
);
3686 if (s
->responselen
- (s
->p
-s
->response
) <
3689 s
->commentp
= (char *)s
->p
;
3690 s
->p
+= s
->commentlen
;
3694 logevent("Pageant key list packet was truncated");
3698 if (s
->publickey_blob
) {
3699 if (!memcmp(pkblob
, s
->publickey_blob
,
3700 s
->publickey_bloblen
)) {
3701 logeventf(ssh
, "Pageant key #%d matches "
3702 "configured key file", s
->keyi
);
3703 s
->tried_publickey
= 1;
3705 /* Skip non-configured key */
3708 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
3709 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3710 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3712 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3713 logevent("Key refused");
3716 logevent("Received RSA challenge");
3717 if ((s
->challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3718 bombout(("Server's RSA challenge was badly formatted"));
3723 char *agentreq
, *q
, *ret
;
3726 len
= 1 + 4; /* message type, bit count */
3727 len
+= ssh1_bignum_length(s
->key
.exponent
);
3728 len
+= ssh1_bignum_length(s
->key
.modulus
);
3729 len
+= ssh1_bignum_length(s
->challenge
);
3730 len
+= 16; /* session id */
3731 len
+= 4; /* response format */
3732 agentreq
= snewn(4 + len
, char);
3733 PUT_32BIT(agentreq
, len
);
3735 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
3736 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
3738 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
3739 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
3740 q
+= ssh1_write_bignum(q
, s
->challenge
);
3741 memcpy(q
, s
->session_id
, 16);
3743 PUT_32BIT(q
, 1); /* response format */
3744 if (!agent_query(agentreq
, len
+ 4, &vret
, &retlen
,
3745 ssh_agent_callback
, ssh
)) {
3750 bombout(("Unexpected data from server"
3751 " while waiting for agent"
3755 } while (pktin
|| inlen
> 0);
3756 vret
= ssh
->agent_response
;
3757 retlen
= ssh
->agent_response_len
;
3762 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
3763 logevent("Sending Pageant's response");
3764 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3765 PKT_DATA
, ret
+ 5, 16,
3769 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
3771 ("Pageant's response accepted");
3772 if (flags
& FLAG_VERBOSE
) {
3773 c_write_str(ssh
, "Authenticated using"
3775 c_write(ssh
, s
->commentp
,
3777 c_write_str(ssh
, "\" from agent\r\n");
3782 ("Pageant's response not accepted");
3785 ("Pageant failed to answer challenge");
3789 logevent("No reply received from Pageant");
3792 freebn(s
->key
.exponent
);
3793 freebn(s
->key
.modulus
);
3794 freebn(s
->challenge
);
3799 if (s
->publickey_blob
&& !s
->tried_publickey
)
3800 logevent("Configured key file not in Pageant");
3802 logevent("Failed to get reply from Pageant");
3807 if (s
->publickey_blob
&& !s
->tried_publickey
) {
3809 * Try public key authentication with the specified
3812 int got_passphrase
; /* need not be kept over crReturn */
3813 if (flags
& FLAG_VERBOSE
)
3814 c_write_str(ssh
, "Trying public key authentication.\r\n");
3815 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3816 logeventf(ssh
, "Trying public key \"%s\"",
3817 filename_to_str(s
->keyfile
));
3818 s
->tried_publickey
= 1;
3819 got_passphrase
= FALSE
;
3820 while (!got_passphrase
) {
3822 * Get a passphrase, if necessary.
3824 char *passphrase
= NULL
; /* only written after crReturn */
3826 if (!s
->publickey_encrypted
) {
3827 if (flags
& FLAG_VERBOSE
)
3828 c_write_str(ssh
, "No passphrase required.\r\n");
3831 int ret
; /* need not be kept over crReturn */
3832 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3833 s
->cur_prompt
->to_server
= FALSE
;
3834 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
3835 add_prompt(s
->cur_prompt
,
3836 dupprintf("Passphrase for key \"%.100s\": ",
3837 s
->publickey_comment
), FALSE
);
3838 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
3841 crWaitUntil(!pktin
);
3842 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
3846 /* Failed to get a passphrase. Terminate. */
3847 free_prompts(s
->cur_prompt
);
3848 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
3852 passphrase
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
3853 free_prompts(s
->cur_prompt
);
3856 * Try decrypting key with passphrase.
3858 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
3859 ret
= loadrsakey(s
->keyfile
, &s
->key
, passphrase
,
3862 smemclr(passphrase
, strlen(passphrase
));
3866 /* Correct passphrase. */
3867 got_passphrase
= TRUE
;
3868 } else if (ret
== 0) {
3869 c_write_str(ssh
, "Couldn't load private key from ");
3870 c_write_str(ssh
, filename_to_str(s
->keyfile
));
3871 c_write_str(ssh
, " (");
3872 c_write_str(ssh
, error
);
3873 c_write_str(ssh
, ").\r\n");
3874 got_passphrase
= FALSE
;
3875 break; /* go and try something else */
3876 } else if (ret
== -1) {
3877 c_write_str(ssh
, "Wrong passphrase.\r\n"); /* FIXME */
3878 got_passphrase
= FALSE
;
3881 assert(0 && "unexpected return from loadrsakey()");
3882 got_passphrase
= FALSE
; /* placate optimisers */
3886 if (got_passphrase
) {
3889 * Send a public key attempt.
3891 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
3892 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
3895 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3896 c_write_str(ssh
, "Server refused our public key.\r\n");
3897 continue; /* go and try something else */
3899 if (pktin
->type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
3900 bombout(("Bizarre response to offer of public key"));
3906 unsigned char buffer
[32];
3907 Bignum challenge
, response
;
3909 if ((challenge
= ssh1_pkt_getmp(pktin
)) == NULL
) {
3910 bombout(("Server's RSA challenge was badly formatted"));
3913 response
= rsadecrypt(challenge
, &s
->key
);
3914 freebn(s
->key
.private_exponent
);/* burn the evidence */
3916 for (i
= 0; i
< 32; i
++) {
3917 buffer
[i
] = bignum_byte(response
, 31 - i
);
3921 MD5Update(&md5c
, buffer
, 32);
3922 MD5Update(&md5c
, s
->session_id
, 16);
3923 MD5Final(buffer
, &md5c
);
3925 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
3926 PKT_DATA
, buffer
, 16, PKT_END
);
3933 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
3934 if (flags
& FLAG_VERBOSE
)
3935 c_write_str(ssh
, "Failed to authenticate with"
3936 " our public key.\r\n");
3937 continue; /* go and try something else */
3938 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
3939 bombout(("Bizarre response to RSA authentication response"));
3943 break; /* we're through! */
3949 * Otherwise, try various forms of password-like authentication.
3951 s
->cur_prompt
= new_prompts(ssh
->frontend
);
3953 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
3954 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
3955 !s
->tis_auth_refused
) {
3956 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
3957 logevent("Requested TIS authentication");
3958 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
3960 if (pktin
->type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
3961 logevent("TIS authentication declined");
3962 if (flags
& FLAG_INTERACTIVE
)
3963 c_write_str(ssh
, "TIS authentication refused.\r\n");
3964 s
->tis_auth_refused
= 1;
3969 char *instr_suf
, *prompt
;
3971 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
3973 bombout(("TIS challenge packet was badly formed"));
3976 logevent("Received TIS challenge");
3977 s
->cur_prompt
->to_server
= TRUE
;
3978 s
->cur_prompt
->name
= dupstr("SSH TIS authentication");
3979 /* Prompt heuristic comes from OpenSSH */
3980 if (memchr(challenge
, '\n', challengelen
)) {
3981 instr_suf
= dupstr("");
3982 prompt
= dupprintf("%.*s", challengelen
, challenge
);
3984 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
3985 prompt
= dupstr("Response: ");
3987 s
->cur_prompt
->instruction
=
3988 dupprintf("Using TIS authentication.%s%s",
3989 (*instr_suf
) ?
"\n" : "",
3991 s
->cur_prompt
->instr_reqd
= TRUE
;
3992 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
3996 if (conf_get_int(ssh
->conf
, CONF_try_tis_auth
) &&
3997 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
3998 !s
->ccard_auth_refused
) {
3999 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
4000 logevent("Requested CryptoCard authentication");
4001 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
4003 if (pktin
->type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
4004 logevent("CryptoCard authentication declined");
4005 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
4006 s
->ccard_auth_refused
= 1;
4011 char *instr_suf
, *prompt
;
4013 ssh_pkt_getstring(pktin
, &challenge
, &challengelen
);
4015 bombout(("CryptoCard challenge packet was badly formed"));
4018 logevent("Received CryptoCard challenge");
4019 s
->cur_prompt
->to_server
= TRUE
;
4020 s
->cur_prompt
->name
= dupstr("SSH CryptoCard authentication");
4021 s
->cur_prompt
->name_reqd
= FALSE
;
4022 /* Prompt heuristic comes from OpenSSH */
4023 if (memchr(challenge
, '\n', challengelen
)) {
4024 instr_suf
= dupstr("");
4025 prompt
= dupprintf("%.*s", challengelen
, challenge
);
4027 instr_suf
= dupprintf("%.*s", challengelen
, challenge
);
4028 prompt
= dupstr("Response: ");
4030 s
->cur_prompt
->instruction
=
4031 dupprintf("Using CryptoCard authentication.%s%s",
4032 (*instr_suf
) ?
"\n" : "",
4034 s
->cur_prompt
->instr_reqd
= TRUE
;
4035 add_prompt(s
->cur_prompt
, prompt
, FALSE
);
4039 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4040 if ((s
->supported_auths_mask
& (1 << SSH1_AUTH_PASSWORD
)) == 0) {
4041 bombout(("No supported authentication methods available"));
4044 s
->cur_prompt
->to_server
= TRUE
;
4045 s
->cur_prompt
->name
= dupstr("SSH password");
4046 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
4047 ssh
->username
, ssh
->savedhost
),
4052 * Show password prompt, having first obtained it via a TIS
4053 * or CryptoCard exchange if we're doing TIS or CryptoCard
4057 int ret
; /* need not be kept over crReturn */
4058 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
4061 crWaitUntil(!pktin
);
4062 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
4067 * Failed to get a password (for example
4068 * because one was supplied on the command line
4069 * which has already failed to work). Terminate.
4071 free_prompts(s
->cur_prompt
);
4072 ssh_disconnect(ssh
, NULL
, "Unable to authenticate", 0, TRUE
);
4077 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
4079 * Defence against traffic analysis: we send a
4080 * whole bunch of packets containing strings of
4081 * different lengths. One of these strings is the
4082 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
4083 * The others are all random data in
4084 * SSH1_MSG_IGNORE packets. This way a passive
4085 * listener can't tell which is the password, and
4086 * hence can't deduce the password length.
4088 * Anybody with a password length greater than 16
4089 * bytes is going to have enough entropy in their
4090 * password that a listener won't find it _that_
4091 * much help to know how long it is. So what we'll
4094 * - if password length < 16, we send 15 packets
4095 * containing string lengths 1 through 15
4097 * - otherwise, we let N be the nearest multiple
4098 * of 8 below the password length, and send 8
4099 * packets containing string lengths N through
4100 * N+7. This won't obscure the order of
4101 * magnitude of the password length, but it will
4102 * introduce a bit of extra uncertainty.
4104 * A few servers can't deal with SSH1_MSG_IGNORE, at
4105 * least in this context. For these servers, we need
4106 * an alternative defence. We make use of the fact
4107 * that the password is interpreted as a C string:
4108 * so we can append a NUL, then some random data.
4110 * A few servers can deal with neither SSH1_MSG_IGNORE
4111 * here _nor_ a padded password string.
4112 * For these servers we are left with no defences
4113 * against password length sniffing.
4115 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) &&
4116 !(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4118 * The server can deal with SSH1_MSG_IGNORE, so
4119 * we can use the primary defence.
4121 int bottom
, top
, pwlen
, i
;
4124 pwlen
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4126 bottom
= 0; /* zero length passwords are OK! :-) */
4129 bottom
= pwlen
& ~7;
4133 assert(pwlen
>= bottom
&& pwlen
<= top
);
4135 randomstr
= snewn(top
+ 1, char);
4137 for (i
= bottom
; i
<= top
; i
++) {
4139 defer_packet(ssh
, s
->pwpkt_type
,
4140 PKTT_PASSWORD
, PKT_STR
,
4141 s
->cur_prompt
->prompts
[0]->result
,
4142 PKTT_OTHER
, PKT_END
);
4144 for (j
= 0; j
< i
; j
++) {
4146 randomstr
[j
] = random_byte();
4147 } while (randomstr
[j
] == '\0');
4149 randomstr
[i
] = '\0';
4150 defer_packet(ssh
, SSH1_MSG_IGNORE
,
4151 PKT_STR
, randomstr
, PKT_END
);
4154 logevent("Sending password with camouflage packets");
4155 ssh_pkt_defersend(ssh
);
4158 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
4160 * The server can't deal with SSH1_MSG_IGNORE
4161 * but can deal with padded passwords, so we
4162 * can use the secondary defence.
4168 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4169 if (len
< sizeof(string
)) {
4171 strcpy(string
, s
->cur_prompt
->prompts
[0]->result
);
4172 len
++; /* cover the zero byte */
4173 while (len
< sizeof(string
)) {
4174 string
[len
++] = (char) random_byte();
4177 ss
= s
->cur_prompt
->prompts
[0]->result
;
4179 logevent("Sending length-padded password");
4180 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4181 PKT_INT
, len
, PKT_DATA
, ss
, len
,
4182 PKTT_OTHER
, PKT_END
);
4185 * The server is believed unable to cope with
4186 * any of our password camouflage methods.
4189 len
= strlen(s
->cur_prompt
->prompts
[0]->result
);
4190 logevent("Sending unpadded password");
4191 send_packet(ssh
, s
->pwpkt_type
,
4192 PKTT_PASSWORD
, PKT_INT
, len
,
4193 PKT_DATA
, s
->cur_prompt
->prompts
[0]->result
, len
,
4194 PKTT_OTHER
, PKT_END
);
4197 send_packet(ssh
, s
->pwpkt_type
, PKTT_PASSWORD
,
4198 PKT_STR
, s
->cur_prompt
->prompts
[0]->result
,
4199 PKTT_OTHER
, PKT_END
);
4201 logevent("Sent password");
4202 free_prompts(s
->cur_prompt
);
4204 if (pktin
->type
== SSH1_SMSG_FAILURE
) {
4205 if (flags
& FLAG_VERBOSE
)
4206 c_write_str(ssh
, "Access denied\r\n");
4207 logevent("Authentication refused");
4208 } else if (pktin
->type
!= SSH1_SMSG_SUCCESS
) {
4209 bombout(("Strange packet received, type %d", pktin
->type
));
4215 if (s
->publickey_blob
) {
4216 sfree(s
->publickey_blob
);
4217 sfree(s
->publickey_comment
);
4220 logevent("Authentication successful");
4225 static void ssh_channel_try_eof(struct ssh_channel
*c
)
4228 assert(c
->pending_eof
); /* precondition for calling us */
4230 return; /* can't close: not even opened yet */
4231 if (ssh
->version
== 2 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0)
4232 return; /* can't send EOF: pending outgoing data */
4234 if (ssh
->version
== 1) {
4235 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4237 c
->closes
|= CLOSES_SENT_EOF
;
4239 struct Packet
*pktout
;
4240 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
4241 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4242 ssh2_pkt_send(ssh
, pktout
);
4243 c
->closes
|= CLOSES_SENT_EOF
;
4244 if (!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
)) {
4246 * Also send MSG_CLOSE.
4248 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4249 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4250 ssh2_pkt_send(ssh
, pktout
);
4251 c
->closes
|= CLOSES_SENT_CLOSE
;
4254 c
->pending_eof
= FALSE
; /* we've sent it now */
4257 void sshfwd_write_eof(struct ssh_channel
*c
)
4261 if (ssh
->state
== SSH_STATE_CLOSED
)
4264 if (c
->closes
& CLOSES_SENT_EOF
)
4267 c
->pending_eof
= TRUE
;
4268 ssh_channel_try_eof(c
);
4271 void sshfwd_unclean_close(struct ssh_channel
*c
)
4274 struct Packet
*pktout
;
4276 if (ssh
->state
== SSH_STATE_CLOSED
)
4279 if (!(c
->closes
& CLOSES_SENT_CLOSE
)) {
4280 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4281 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
4282 ssh2_pkt_send(ssh
, pktout
);
4283 c
->closes
|= CLOSES_SENT_EOF
| CLOSES_SENT_CLOSE
;
4288 x11_close(c
->u
.x11
.s
);
4291 case CHAN_SOCKDATA_DORMANT
:
4292 pfd_close(c
->u
.pfd
.s
);
4295 c
->type
= CHAN_ZOMBIE
;
4297 ssh2_channel_check_close(c
);
4300 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
4304 if (ssh
->state
== SSH_STATE_CLOSED
)
4307 if (ssh
->version
== 1) {
4308 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
4309 PKT_INT
, c
->remoteid
,
4310 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, buf
, len
,
4311 PKTT_OTHER
, PKT_END
);
4313 * In SSH-1 we can return 0 here - implying that forwarded
4314 * connections are never individually throttled - because
4315 * the only circumstance that can cause throttling will be
4316 * the whole SSH connection backing up, in which case
4317 * _everything_ will be throttled as a whole.
4321 ssh2_add_channel_data(c
, buf
, len
);
4322 return ssh2_try_send(c
);
4326 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
4331 if (ssh
->state
== SSH_STATE_CLOSED
)
4334 if (ssh
->version
== 1) {
4335 buflimit
= SSH1_BUFFER_LIMIT
;
4337 buflimit
= c
->v
.v2
.locmaxwin
;
4338 ssh2_set_window(c
, bufsize
< buflimit ? buflimit
- bufsize
: 0);
4340 if (c
->throttling_conn
&& bufsize
<= buflimit
) {
4341 c
->throttling_conn
= 0;
4342 ssh_throttle_conn(ssh
, -1);
4346 static void ssh_queueing_handler(Ssh ssh
, struct Packet
*pktin
)
4348 struct queued_handler
*qh
= ssh
->qhead
;
4352 assert(pktin
->type
== qh
->msg1
|| pktin
->type
== qh
->msg2
);
4355 assert(ssh
->packet_dispatch
[qh
->msg1
] == ssh_queueing_handler
);
4356 ssh
->packet_dispatch
[qh
->msg1
] = NULL
;
4359 assert(ssh
->packet_dispatch
[qh
->msg2
] == ssh_queueing_handler
);
4360 ssh
->packet_dispatch
[qh
->msg2
] = NULL
;
4364 ssh
->qhead
= qh
->next
;
4366 if (ssh
->qhead
->msg1
> 0) {
4367 assert(ssh
->packet_dispatch
[ssh
->qhead
->msg1
] == NULL
);
4368 ssh
->packet_dispatch
[ssh
->qhead
->msg1
] = ssh_queueing_handler
;
4370 if (ssh
->qhead
->msg2
> 0) {
4371 assert(ssh
->packet_dispatch
[ssh
->qhead
->msg2
] == NULL
);
4372 ssh
->packet_dispatch
[ssh
->qhead
->msg2
] = ssh_queueing_handler
;
4375 ssh
->qhead
= ssh
->qtail
= NULL
;
4376 ssh
->packet_dispatch
[pktin
->type
] = 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 assert(ssh
->packet_dispatch
[qh
->msg1
] == NULL
);
4401 ssh
->packet_dispatch
[qh
->msg1
] = ssh_queueing_handler
;
4404 assert(ssh
->packet_dispatch
[qh
->msg2
] == NULL
);
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
);
4964 x11_send_eof(c
->u
.pfd
.s
);
4971 if (send_close
&& !(c
->closes
& CLOSES_SENT_EOF
)) {
4972 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
4974 c
->closes
|= CLOSES_SENT_EOF
;
4978 if (pktin
->type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
&&
4979 !(c
->closes
& CLOSES_RCVD_CLOSE
)) {
4981 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
4982 bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d"
4983 " for which we never sent CHANNEL_CLOSE\n", i
));
4986 c
->closes
|= CLOSES_RCVD_CLOSE
;
4989 if (!((CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) & ~c
->closes
) &&
4990 !(c
->closes
& CLOSES_SENT_CLOSE
)) {
4991 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
,
4992 PKT_INT
, c
->remoteid
, PKT_END
);
4993 c
->closes
|= CLOSES_SENT_CLOSE
;
4996 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
))
4997 ssh_channel_destroy(c
);
4999 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
5000 pktin
->type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
5001 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
5006 static void ssh1_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
5008 /* Data sent down one of our channels. */
5009 int i
= ssh_pkt_getuint32(pktin
);
5012 struct ssh_channel
*c
;
5014 ssh_pkt_getstring(pktin
, &p
, &len
);
5016 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5021 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
5024 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
5027 /* Data for an agent message. Buffer it. */
5029 if (c
->u
.a
.lensofar
< 4) {
5030 unsigned int l
= min(4 - c
->u
.a
.lensofar
, (unsigned)len
);
5031 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
5035 c
->u
.a
.lensofar
+= l
;
5037 if (c
->u
.a
.lensofar
== 4) {
5039 4 + GET_32BIT(c
->u
.a
.msglen
);
5040 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
5042 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5044 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
5046 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5048 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
5052 c
->u
.a
.lensofar
+= l
;
5054 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5057 if (agent_query(c
->u
.a
.message
,
5060 ssh_agentf_callback
, c
))
5061 ssh_agentf_callback(c
, reply
, replylen
);
5062 sfree(c
->u
.a
.message
);
5063 c
->u
.a
.lensofar
= 0;
5066 bufsize
= 0; /* agent channels never back up */
5069 if (!c
->throttling_conn
&& bufsize
> SSH1_BUFFER_LIMIT
) {
5070 c
->throttling_conn
= 1;
5071 ssh_throttle_conn(ssh
, +1);
5076 static void ssh1_smsg_exit_status(Ssh ssh
, struct Packet
*pktin
)
5078 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
5079 logeventf(ssh
, "Server sent command exit status %d", ssh
->exitcode
);
5080 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
5082 * In case `helpful' firewalls or proxies tack
5083 * extra human-readable text on the end of the
5084 * session which we might mistake for another
5085 * encrypted packet, we close the session once
5086 * we've sent EXIT_CONFIRMATION.
5088 ssh_disconnect(ssh
, NULL
, NULL
, 0, TRUE
);
5091 /* Helper function to deal with sending tty modes for REQUEST_PTY */
5092 static void ssh1_send_ttymode(void *data
, char *mode
, char *val
)
5094 struct Packet
*pktout
= (struct Packet
*)data
;
5096 unsigned int arg
= 0;
5097 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
5098 if (i
== lenof(ssh_ttymodes
)) return;
5099 switch (ssh_ttymodes
[i
].type
) {
5101 arg
= ssh_tty_parse_specchar(val
);
5104 arg
= ssh_tty_parse_boolean(val
);
5107 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
5108 ssh2_pkt_addbyte(pktout
, arg
);
5112 static void do_ssh1_connection(Ssh ssh
, unsigned char *in
, int inlen
,
5113 struct Packet
*pktin
)
5115 crBegin(ssh
->do_ssh1_connection_crstate
);
5117 ssh
->packet_dispatch
[SSH1_SMSG_STDOUT_DATA
] =
5118 ssh
->packet_dispatch
[SSH1_SMSG_STDERR_DATA
] =
5119 ssh1_smsg_stdout_stderr_data
;
5121 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
] =
5122 ssh1_msg_channel_open_confirmation
;
5123 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_OPEN_FAILURE
] =
5124 ssh1_msg_channel_open_failure
;
5125 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE
] =
5126 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
] =
5127 ssh1_msg_channel_close
;
5128 ssh
->packet_dispatch
[SSH1_MSG_CHANNEL_DATA
] = ssh1_msg_channel_data
;
5129 ssh
->packet_dispatch
[SSH1_SMSG_EXIT_STATUS
] = ssh1_smsg_exit_status
;
5131 if (conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
5132 logevent("Requesting agent forwarding");
5133 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
5137 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5138 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5139 bombout(("Protocol confusion"));
5141 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5142 logevent("Agent forwarding refused");
5144 logevent("Agent forwarding enabled");
5145 ssh
->agentfwd_enabled
= TRUE
;
5146 ssh
->packet_dispatch
[SSH1_SMSG_AGENT_OPEN
] = ssh1_smsg_agent_open
;
5150 if (conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
5151 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
5152 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
5153 logevent("Requesting X11 forwarding");
5155 * Note that while we blank the X authentication data here, we don't
5156 * take any special action to blank the start of an X11 channel,
5157 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
5158 * without having session blanking enabled is likely to leak your
5159 * cookie into the log.
5161 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
5162 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5163 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5165 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5167 PKT_INT
, ssh
->x11disp
->screennum
,
5170 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
5171 PKT_STR
, ssh
->x11disp
->remoteauthprotoname
,
5173 PKT_STR
, ssh
->x11disp
->remoteauthdatastring
,
5180 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5181 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5182 bombout(("Protocol confusion"));
5184 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5185 logevent("X11 forwarding refused");
5187 logevent("X11 forwarding enabled");
5188 ssh
->X11_fwd_enabled
= TRUE
;
5189 ssh
->packet_dispatch
[SSH1_SMSG_X11_OPEN
] = ssh1_smsg_x11_open
;
5193 ssh_setup_portfwd(ssh
, ssh
->conf
);
5194 ssh
->packet_dispatch
[SSH1_MSG_PORT_OPEN
] = ssh1_msg_port_open
;
5196 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
5198 /* Unpick the terminal-speed string. */
5199 /* XXX perhaps we should allow no speeds to be sent. */
5200 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
5201 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
5202 /* Send the pty request. */
5203 pkt
= ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY
);
5204 ssh_pkt_addstring(pkt
, conf_get_str(ssh
->conf
, CONF_termtype
));
5205 ssh_pkt_adduint32(pkt
, ssh
->term_height
);
5206 ssh_pkt_adduint32(pkt
, ssh
->term_width
);
5207 ssh_pkt_adduint32(pkt
, 0); /* width in pixels */
5208 ssh_pkt_adduint32(pkt
, 0); /* height in pixels */
5209 parse_ttymodes(ssh
, ssh1_send_ttymode
, (void *)pkt
);
5210 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_ISPEED
);
5211 ssh_pkt_adduint32(pkt
, ssh
->ispeed
);
5212 ssh_pkt_addbyte(pkt
, SSH1_TTY_OP_OSPEED
);
5213 ssh_pkt_adduint32(pkt
, ssh
->ospeed
);
5214 ssh_pkt_addbyte(pkt
, SSH_TTY_OP_END
);
5216 ssh
->state
= SSH_STATE_INTERMED
;
5220 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5221 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5222 bombout(("Protocol confusion"));
5224 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5225 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5226 ssh
->editing
= ssh
->echoing
= 1;
5228 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
5229 ssh
->ospeed
, ssh
->ispeed
);
5230 ssh
->got_pty
= TRUE
;
5233 ssh
->editing
= ssh
->echoing
= 1;
5236 if (conf_get_int(ssh
->conf
, CONF_compression
)) {
5237 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
5241 if (pktin
->type
!= SSH1_SMSG_SUCCESS
5242 && pktin
->type
!= SSH1_SMSG_FAILURE
) {
5243 bombout(("Protocol confusion"));
5245 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5246 c_write_str(ssh
, "Server refused to compress\r\n");
5248 logevent("Started compression");
5249 ssh
->v1_compressing
= TRUE
;
5250 ssh
->cs_comp_ctx
= zlib_compress_init();
5251 logevent("Initialised zlib (RFC1950) compression");
5252 ssh
->sc_comp_ctx
= zlib_decompress_init();
5253 logevent("Initialised zlib (RFC1950) decompression");
5257 * Start the shell or command.
5259 * Special case: if the first-choice command is an SSH-2
5260 * subsystem (hence not usable here) and the second choice
5261 * exists, we fall straight back to that.
5264 char *cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
5266 if (conf_get_int(ssh
->conf
, CONF_ssh_subsys
) &&
5267 conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
5268 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
5269 ssh
->fallback_cmd
= TRUE
;
5272 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
5274 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
5275 logevent("Started session");
5278 ssh
->state
= SSH_STATE_SESSION
;
5279 if (ssh
->size_needed
)
5280 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5281 if (ssh
->eof_needed
)
5282 ssh_special(ssh
, TS_EOF
);
5285 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5287 ssh
->channels
= newtree234(ssh_channelcmp
);
5291 * By this point, most incoming packets are already being
5292 * handled by the dispatch table, and we need only pay
5293 * attention to the unusual ones.
5298 if (pktin
->type
== SSH1_SMSG_SUCCESS
) {
5299 /* may be from EXEC_SHELL on some servers */
5300 } else if (pktin
->type
== SSH1_SMSG_FAILURE
) {
5301 /* may be from EXEC_SHELL on some servers
5302 * if no pty is available or in other odd cases. Ignore */
5304 bombout(("Strange packet received: type %d", pktin
->type
));
5309 int len
= min(inlen
, 512);
5310 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
5311 PKT_INT
, len
, PKTT_DATA
, PKT_DATA
, in
, len
,
5312 PKTT_OTHER
, PKT_END
);
5323 * Handle the top-level SSH-2 protocol.
5325 static void ssh1_msg_debug(Ssh ssh
, struct Packet
*pktin
)
5330 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5331 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
5334 static void ssh1_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
5336 /* log reason code in disconnect message */
5340 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
5341 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen
, msg
));
5344 static void ssh_msg_ignore(Ssh ssh
, struct Packet
*pktin
)
5346 /* Do nothing, because we're ignoring it! Duhh. */
5349 static void ssh1_protocol_setup(Ssh ssh
)
5354 * Most messages are handled by the coroutines.
5356 for (i
= 0; i
< 256; i
++)
5357 ssh
->packet_dispatch
[i
] = NULL
;
5360 * These special message types we install handlers for.
5362 ssh
->packet_dispatch
[SSH1_MSG_DISCONNECT
] = ssh1_msg_disconnect
;
5363 ssh
->packet_dispatch
[SSH1_MSG_IGNORE
] = ssh_msg_ignore
;
5364 ssh
->packet_dispatch
[SSH1_MSG_DEBUG
] = ssh1_msg_debug
;
5367 static void ssh1_protocol(Ssh ssh
, void *vin
, int inlen
,
5368 struct Packet
*pktin
)
5370 unsigned char *in
=(unsigned char*)vin
;
5371 if (ssh
->state
== SSH_STATE_CLOSED
)
5374 if (pktin
&& ssh
->packet_dispatch
[pktin
->type
]) {
5375 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
5379 if (!ssh
->protocol_initial_phase_done
) {
5380 if (do_ssh1_login(ssh
, in
, inlen
, pktin
))
5381 ssh
->protocol_initial_phase_done
= TRUE
;
5386 do_ssh1_connection(ssh
, in
, inlen
, pktin
);
5390 * Utility routine for decoding comma-separated strings in KEXINIT.
5392 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
5395 if (!needle
|| !haystack
) /* protect against null pointers */
5397 needlen
= strlen(needle
);
5400 * Is it at the start of the string?
5402 if (haylen
>= needlen
&& /* haystack is long enough */
5403 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5404 (haylen
== needlen
|| haystack
[needlen
] == ',')
5405 /* either , or EOS follows */
5409 * If not, search for the next comma and resume after that.
5410 * If no comma found, terminate.
5412 while (haylen
> 0 && *haystack
!= ',')
5413 haylen
--, haystack
++;
5416 haylen
--, haystack
++; /* skip over comma itself */
5421 * Similar routine for checking whether we have the first string in a list.
5423 static int first_in_commasep_string(char *needle
, char *haystack
, int haylen
)
5426 if (!needle
|| !haystack
) /* protect against null pointers */
5428 needlen
= strlen(needle
);
5430 * Is it at the start of the string?
5432 if (haylen
>= needlen
&& /* haystack is long enough */
5433 !memcmp(needle
, haystack
, needlen
) && /* initial match */
5434 (haylen
== needlen
|| haystack
[needlen
] == ',')
5435 /* either , or EOS follows */
5443 * SSH-2 key creation method.
5444 * (Currently assumes 2 lots of any hash are sufficient to generate
5445 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5447 #define SSH2_MKKEY_ITERS (2)
5448 static void ssh2_mkkey(Ssh ssh
, Bignum K
, unsigned char *H
, char chr
,
5449 unsigned char *keyspace
)
5451 const struct ssh_hash
*h
= ssh
->kex
->hash
;
5453 /* First hlen bytes. */
5455 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5456 hash_mpint(h
, s
, K
);
5457 h
->bytes(s
, H
, h
->hlen
);
5458 h
->bytes(s
, &chr
, 1);
5459 h
->bytes(s
, ssh
->v2_session_id
, ssh
->v2_session_id_len
);
5460 h
->final(s
, keyspace
);
5461 /* Next hlen bytes. */
5463 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
5464 hash_mpint(h
, s
, K
);
5465 h
->bytes(s
, H
, h
->hlen
);
5466 h
->bytes(s
, keyspace
, h
->hlen
);
5467 h
->final(s
, keyspace
+ h
->hlen
);
5471 * Handle the SSH-2 transport layer.
5473 static int do_ssh2_transport(Ssh ssh
, void *vin
, int inlen
,
5474 struct Packet
*pktin
)
5476 unsigned char *in
= (unsigned char *)vin
;
5477 struct do_ssh2_transport_state
{
5479 int nbits
, pbits
, warn_kex
, warn_cscipher
, warn_sccipher
;
5480 Bignum p
, g
, e
, f
, K
;
5483 int kex_init_value
, kex_reply_value
;
5484 const struct ssh_mac
**maclist
;
5486 const struct ssh2_cipher
*cscipher_tobe
;
5487 const struct ssh2_cipher
*sccipher_tobe
;
5488 const struct ssh_mac
*csmac_tobe
;
5489 const struct ssh_mac
*scmac_tobe
;
5490 const struct ssh_compress
*cscomp_tobe
;
5491 const struct ssh_compress
*sccomp_tobe
;
5492 char *hostkeydata
, *sigdata
, *rsakeydata
, *keystr
, *fingerprint
;
5493 int hostkeylen
, siglen
, rsakeylen
;
5494 void *hkey
; /* actual host key */
5495 void *rsakey
; /* for RSA kex */
5496 unsigned char exchange_hash
[SSH2_KEX_MAX_HASH_LEN
];
5497 int n_preferred_kex
;
5498 const struct ssh_kexes
*preferred_kex
[KEX_MAX
];
5499 int n_preferred_ciphers
;
5500 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
5501 const struct ssh_compress
*preferred_comp
;
5502 int userauth_succeeded
; /* for delayed compression */
5503 int pending_compression
;
5504 int got_session_id
, activated_authconn
;
5505 struct Packet
*pktout
;
5510 crState(do_ssh2_transport_state
);
5514 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
5515 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
5516 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
5518 s
->got_session_id
= s
->activated_authconn
= FALSE
;
5519 s
->userauth_succeeded
= FALSE
;
5520 s
->pending_compression
= FALSE
;
5523 * Be prepared to work around the buggy MAC problem.
5525 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
5526 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
5528 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
5531 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
5533 int i
, j
, commalist_started
;
5536 * Set up the preferred key exchange. (NULL => warn below here)
5538 s
->n_preferred_kex
= 0;
5539 for (i
= 0; i
< KEX_MAX
; i
++) {
5540 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_kexlist
, i
)) {
5542 s
->preferred_kex
[s
->n_preferred_kex
++] =
5543 &ssh_diffiehellman_gex
;
5546 s
->preferred_kex
[s
->n_preferred_kex
++] =
5547 &ssh_diffiehellman_group14
;
5550 s
->preferred_kex
[s
->n_preferred_kex
++] =
5551 &ssh_diffiehellman_group1
;
5554 s
->preferred_kex
[s
->n_preferred_kex
++] =
5558 /* Flag for later. Don't bother if it's the last in
5560 if (i
< KEX_MAX
- 1) {
5561 s
->preferred_kex
[s
->n_preferred_kex
++] = NULL
;
5568 * Set up the preferred ciphers. (NULL => warn below here)
5570 s
->n_preferred_ciphers
= 0;
5571 for (i
= 0; i
< CIPHER_MAX
; i
++) {
5572 switch (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
)) {
5573 case CIPHER_BLOWFISH
:
5574 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
5577 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
)) {
5578 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
5582 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
5585 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
5587 case CIPHER_ARCFOUR
:
5588 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_arcfour
;
5591 /* Flag for later. Don't bother if it's the last in
5593 if (i
< CIPHER_MAX
- 1) {
5594 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
5601 * Set up preferred compression.
5603 if (conf_get_int(ssh
->conf
, CONF_compression
))
5604 s
->preferred_comp
= &ssh_zlib
;
5606 s
->preferred_comp
= &ssh_comp_none
;
5609 * Enable queueing of outgoing auth- or connection-layer
5610 * packets while we are in the middle of a key exchange.
5612 ssh
->queueing
= TRUE
;
5615 * Flag that KEX is in progress.
5617 ssh
->kex_in_progress
= TRUE
;
5620 * Construct and send our key exchange packet.
5622 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXINIT
);
5623 for (i
= 0; i
< 16; i
++)
5624 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) random_byte());
5625 /* List key exchange algorithms. */
5626 ssh2_pkt_addstring_start(s
->pktout
);
5627 commalist_started
= 0;
5628 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5629 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5630 if (!k
) continue; /* warning flag */
5631 for (j
= 0; j
< k
->nkexes
; j
++) {
5632 if (commalist_started
)
5633 ssh2_pkt_addstring_str(s
->pktout
, ",");
5634 ssh2_pkt_addstring_str(s
->pktout
, k
->list
[j
]->name
);
5635 commalist_started
= 1;
5638 /* List server host key algorithms. */
5639 ssh2_pkt_addstring_start(s
->pktout
);
5640 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5641 ssh2_pkt_addstring_str(s
->pktout
, hostkey_algs
[i
]->name
);
5642 if (i
< lenof(hostkey_algs
) - 1)
5643 ssh2_pkt_addstring_str(s
->pktout
, ",");
5645 /* List client->server encryption algorithms. */
5646 ssh2_pkt_addstring_start(s
->pktout
);
5647 commalist_started
= 0;
5648 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5649 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5650 if (!c
) continue; /* warning flag */
5651 for (j
= 0; j
< c
->nciphers
; j
++) {
5652 if (commalist_started
)
5653 ssh2_pkt_addstring_str(s
->pktout
, ",");
5654 ssh2_pkt_addstring_str(s
->pktout
, c
->list
[j
]->name
);
5655 commalist_started
= 1;
5658 /* List server->client encryption algorithms. */
5659 ssh2_pkt_addstring_start(s
->pktout
);
5660 commalist_started
= 0;
5661 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5662 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5663 if (!c
) continue; /* warning flag */
5664 for (j
= 0; j
< c
->nciphers
; j
++) {
5665 if (commalist_started
)
5666 ssh2_pkt_addstring_str(s
->pktout
, ",");
5667 ssh2_pkt_addstring_str(s
->pktout
, c
->list
[j
]->name
);
5668 commalist_started
= 1;
5671 /* List client->server MAC algorithms. */
5672 ssh2_pkt_addstring_start(s
->pktout
);
5673 for (i
= 0; i
< s
->nmacs
; i
++) {
5674 ssh2_pkt_addstring_str(s
->pktout
, s
->maclist
[i
]->name
);
5675 if (i
< s
->nmacs
- 1)
5676 ssh2_pkt_addstring_str(s
->pktout
, ",");
5678 /* List server->client MAC algorithms. */
5679 ssh2_pkt_addstring_start(s
->pktout
);
5680 for (i
= 0; i
< s
->nmacs
; i
++) {
5681 ssh2_pkt_addstring_str(s
->pktout
, s
->maclist
[i
]->name
);
5682 if (i
< s
->nmacs
- 1)
5683 ssh2_pkt_addstring_str(s
->pktout
, ",");
5685 /* List client->server compression algorithms,
5686 * then server->client compression algorithms. (We use the
5687 * same set twice.) */
5688 for (j
= 0; j
< 2; j
++) {
5689 ssh2_pkt_addstring_start(s
->pktout
);
5690 assert(lenof(compressions
) > 1);
5691 /* Prefer non-delayed versions */
5692 ssh2_pkt_addstring_str(s
->pktout
, s
->preferred_comp
->name
);
5693 /* We don't even list delayed versions of algorithms until
5694 * they're allowed to be used, to avoid a race. See the end of
5696 if (s
->userauth_succeeded
&& s
->preferred_comp
->delayed_name
) {
5697 ssh2_pkt_addstring_str(s
->pktout
, ",");
5698 ssh2_pkt_addstring_str(s
->pktout
,
5699 s
->preferred_comp
->delayed_name
);
5701 for (i
= 0; i
< lenof(compressions
); i
++) {
5702 const struct ssh_compress
*c
= compressions
[i
];
5703 if (c
!= s
->preferred_comp
) {
5704 ssh2_pkt_addstring_str(s
->pktout
, ",");
5705 ssh2_pkt_addstring_str(s
->pktout
, c
->name
);
5706 if (s
->userauth_succeeded
&& c
->delayed_name
) {
5707 ssh2_pkt_addstring_str(s
->pktout
, ",");
5708 ssh2_pkt_addstring_str(s
->pktout
, c
->delayed_name
);
5713 /* List client->server languages. Empty list. */
5714 ssh2_pkt_addstring_start(s
->pktout
);
5715 /* List server->client languages. Empty list. */
5716 ssh2_pkt_addstring_start(s
->pktout
);
5717 /* First KEX packet does _not_ follow, because we're not that brave. */
5718 ssh2_pkt_addbool(s
->pktout
, FALSE
);
5720 ssh2_pkt_adduint32(s
->pktout
, 0);
5723 s
->our_kexinitlen
= s
->pktout
->length
- 5;
5724 s
->our_kexinit
= snewn(s
->our_kexinitlen
, unsigned char);
5725 memcpy(s
->our_kexinit
, s
->pktout
->data
+ 5, s
->our_kexinitlen
);
5727 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
5733 * Now examine the other side's KEXINIT to see what we're up
5737 char *str
, *preferred
;
5740 if (pktin
->type
!= SSH2_MSG_KEXINIT
) {
5741 bombout(("expected key exchange packet from server"));
5745 ssh
->hostkey
= NULL
;
5746 s
->cscipher_tobe
= NULL
;
5747 s
->sccipher_tobe
= NULL
;
5748 s
->csmac_tobe
= NULL
;
5749 s
->scmac_tobe
= NULL
;
5750 s
->cscomp_tobe
= NULL
;
5751 s
->sccomp_tobe
= NULL
;
5752 s
->warn_kex
= s
->warn_cscipher
= s
->warn_sccipher
= FALSE
;
5754 pktin
->savedpos
+= 16; /* skip garbage cookie */
5755 ssh_pkt_getstring(pktin
, &str
, &len
); /* key exchange algorithms */
5758 for (i
= 0; i
< s
->n_preferred_kex
; i
++) {
5759 const struct ssh_kexes
*k
= s
->preferred_kex
[i
];
5763 for (j
= 0; j
< k
->nkexes
; j
++) {
5764 if (!preferred
) preferred
= k
->list
[j
]->name
;
5765 if (in_commasep_string(k
->list
[j
]->name
, str
, len
)) {
5766 ssh
->kex
= k
->list
[j
];
5775 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5776 str ? str
: "(null)"));
5780 * Note that the server's guess is considered wrong if it doesn't match
5781 * the first algorithm in our list, even if it's still the algorithm
5784 s
->guessok
= first_in_commasep_string(preferred
, str
, len
);
5785 ssh_pkt_getstring(pktin
, &str
, &len
); /* host key algorithms */
5786 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
5787 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
5788 ssh
->hostkey
= hostkey_algs
[i
];
5792 if (!ssh
->hostkey
) {
5793 bombout(("Couldn't agree a host key algorithm (available: %s)",
5794 str ? str
: "(null)"));
5798 s
->guessok
= s
->guessok
&&
5799 first_in_commasep_string(hostkey_algs
[0]->name
, str
, len
);
5800 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server cipher */
5801 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5802 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5804 s
->warn_cscipher
= TRUE
;
5806 for (j
= 0; j
< c
->nciphers
; j
++) {
5807 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5808 s
->cscipher_tobe
= c
->list
[j
];
5813 if (s
->cscipher_tobe
)
5816 if (!s
->cscipher_tobe
) {
5817 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5818 str ? str
: "(null)"));
5822 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client cipher */
5823 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
5824 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
5826 s
->warn_sccipher
= TRUE
;
5828 for (j
= 0; j
< c
->nciphers
; j
++) {
5829 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
5830 s
->sccipher_tobe
= c
->list
[j
];
5835 if (s
->sccipher_tobe
)
5838 if (!s
->sccipher_tobe
) {
5839 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5840 str ? str
: "(null)"));
5844 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server mac */
5845 for (i
= 0; i
< s
->nmacs
; i
++) {
5846 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5847 s
->csmac_tobe
= s
->maclist
[i
];
5851 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client mac */
5852 for (i
= 0; i
< s
->nmacs
; i
++) {
5853 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
5854 s
->scmac_tobe
= s
->maclist
[i
];
5858 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server compression */
5859 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5860 const struct ssh_compress
*c
=
5861 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5862 if (in_commasep_string(c
->name
, str
, len
)) {
5865 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5866 if (s
->userauth_succeeded
) {
5870 s
->pending_compression
= TRUE
; /* try this later */
5874 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client compression */
5875 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
5876 const struct ssh_compress
*c
=
5877 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
5878 if (in_commasep_string(c
->name
, str
, len
)) {
5881 } else if (in_commasep_string(c
->delayed_name
, str
, len
)) {
5882 if (s
->userauth_succeeded
) {
5886 s
->pending_compression
= TRUE
; /* try this later */
5890 if (s
->pending_compression
) {
5891 logevent("Server supports delayed compression; "
5892 "will try this later");
5894 ssh_pkt_getstring(pktin
, &str
, &len
); /* client->server language */
5895 ssh_pkt_getstring(pktin
, &str
, &len
); /* server->client language */
5896 s
->ignorepkt
= ssh2_pkt_getbool(pktin
) && !s
->guessok
;
5899 ssh_set_frozen(ssh
, 1);
5900 s
->dlgret
= askalg(ssh
->frontend
, "key-exchange algorithm",
5902 ssh_dialog_callback
, ssh
);
5903 if (s
->dlgret
< 0) {
5907 bombout(("Unexpected data from server while"
5908 " waiting for user response"));
5911 } while (pktin
|| inlen
> 0);
5912 s
->dlgret
= ssh
->user_response
;
5914 ssh_set_frozen(ssh
, 0);
5915 if (s
->dlgret
== 0) {
5916 ssh_disconnect(ssh
, "User aborted at kex warning", NULL
,
5922 if (s
->warn_cscipher
) {
5923 ssh_set_frozen(ssh
, 1);
5924 s
->dlgret
= askalg(ssh
->frontend
,
5925 "client-to-server cipher",
5926 s
->cscipher_tobe
->name
,
5927 ssh_dialog_callback
, ssh
);
5928 if (s
->dlgret
< 0) {
5932 bombout(("Unexpected data from server while"
5933 " waiting for user response"));
5936 } while (pktin
|| inlen
> 0);
5937 s
->dlgret
= ssh
->user_response
;
5939 ssh_set_frozen(ssh
, 0);
5940 if (s
->dlgret
== 0) {
5941 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5947 if (s
->warn_sccipher
) {
5948 ssh_set_frozen(ssh
, 1);
5949 s
->dlgret
= askalg(ssh
->frontend
,
5950 "server-to-client cipher",
5951 s
->sccipher_tobe
->name
,
5952 ssh_dialog_callback
, ssh
);
5953 if (s
->dlgret
< 0) {
5957 bombout(("Unexpected data from server while"
5958 " waiting for user response"));
5961 } while (pktin
|| inlen
> 0);
5962 s
->dlgret
= ssh
->user_response
;
5964 ssh_set_frozen(ssh
, 0);
5965 if (s
->dlgret
== 0) {
5966 ssh_disconnect(ssh
, "User aborted at cipher warning", NULL
,
5972 ssh
->exhash
= ssh
->kex
->hash
->init();
5973 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_c
, strlen(ssh
->v_c
));
5974 hash_string(ssh
->kex
->hash
, ssh
->exhash
, ssh
->v_s
, strlen(ssh
->v_s
));
5975 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5976 s
->our_kexinit
, s
->our_kexinitlen
);
5977 sfree(s
->our_kexinit
);
5978 if (pktin
->length
> 5)
5979 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
5980 pktin
->data
+ 5, pktin
->length
- 5);
5982 if (s
->ignorepkt
) /* first_kex_packet_follows */
5983 crWaitUntil(pktin
); /* Ignore packet */
5986 if (ssh
->kex
->main_type
== KEXTYPE_DH
) {
5988 * Work out the number of bits of key we will need from the
5989 * key exchange. We start with the maximum key length of
5995 csbits
= s
->cscipher_tobe
->keylen
;
5996 scbits
= s
->sccipher_tobe
->keylen
;
5997 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
5999 /* The keys only have hlen-bit entropy, since they're based on
6000 * a hash. So cap the key size at hlen bits. */
6001 if (s
->nbits
> ssh
->kex
->hash
->hlen
* 8)
6002 s
->nbits
= ssh
->kex
->hash
->hlen
* 8;
6005 * If we're doing Diffie-Hellman group exchange, start by
6006 * requesting a group.
6008 if (!ssh
->kex
->pdata
) {
6009 logevent("Doing Diffie-Hellman group exchange");
6010 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGEX
;
6012 * Work out how big a DH group we will need to allow that
6015 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
6016 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
6017 ssh2_pkt_adduint32(s
->pktout
, s
->pbits
);
6018 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6021 if (pktin
->type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
6022 bombout(("expected key exchange group packet from server"));
6025 s
->p
= ssh2_pkt_getmp(pktin
);
6026 s
->g
= ssh2_pkt_getmp(pktin
);
6027 if (!s
->p
|| !s
->g
) {
6028 bombout(("unable to read mp-ints from incoming group packet"));
6031 ssh
->kex_ctx
= dh_setup_gex(s
->p
, s
->g
);
6032 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
6033 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
6035 ssh
->pkt_kctx
= SSH2_PKTCTX_DHGROUP
;
6036 ssh
->kex_ctx
= dh_setup_group(ssh
->kex
);
6037 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
6038 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
6039 logeventf(ssh
, "Using Diffie-Hellman with standard group \"%s\"",
6040 ssh
->kex
->groupname
);
6043 logeventf(ssh
, "Doing Diffie-Hellman key exchange with hash %s",
6044 ssh
->kex
->hash
->text_name
);
6046 * Now generate and send e for Diffie-Hellman.
6048 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* this can take a while */
6049 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
6050 s
->pktout
= ssh2_pkt_init(s
->kex_init_value
);
6051 ssh2_pkt_addmp(s
->pktout
, s
->e
);
6052 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6054 set_busy_status(ssh
->frontend
, BUSY_WAITING
); /* wait for server */
6056 if (pktin
->type
!= s
->kex_reply_value
) {
6057 bombout(("expected key exchange reply packet from server"));
6060 set_busy_status(ssh
->frontend
, BUSY_CPU
); /* cogitate */
6061 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6062 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6063 s
->f
= ssh2_pkt_getmp(pktin
);
6065 bombout(("unable to parse key exchange reply packet"));
6068 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6070 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
6072 /* We assume everything from now on will be quick, and it might
6073 * involve user interaction. */
6074 set_busy_status(ssh
->frontend
, BUSY_NOT
);
6076 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
6077 if (!ssh
->kex
->pdata
) {
6078 hash_uint32(ssh
->kex
->hash
, ssh
->exhash
, s
->pbits
);
6079 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->p
);
6080 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->g
);
6082 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->e
);
6083 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->f
);
6085 dh_cleanup(ssh
->kex_ctx
);
6087 if (!ssh
->kex
->pdata
) {
6092 logeventf(ssh
, "Doing RSA key exchange with hash %s",
6093 ssh
->kex
->hash
->text_name
);
6094 ssh
->pkt_kctx
= SSH2_PKTCTX_RSAKEX
;
6096 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
6100 if (pktin
->type
!= SSH2_MSG_KEXRSA_PUBKEY
) {
6101 bombout(("expected RSA public key packet from server"));
6105 ssh_pkt_getstring(pktin
, &s
->hostkeydata
, &s
->hostkeylen
);
6106 hash_string(ssh
->kex
->hash
, ssh
->exhash
,
6107 s
->hostkeydata
, s
->hostkeylen
);
6108 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
6112 ssh_pkt_getstring(pktin
, &keydata
, &s
->rsakeylen
);
6113 s
->rsakeydata
= snewn(s
->rsakeylen
, char);
6114 memcpy(s
->rsakeydata
, keydata
, s
->rsakeylen
);
6117 s
->rsakey
= ssh_rsakex_newkey(s
->rsakeydata
, s
->rsakeylen
);
6119 sfree(s
->rsakeydata
);
6120 bombout(("unable to parse RSA public key from server"));
6124 hash_string(ssh
->kex
->hash
, ssh
->exhash
, s
->rsakeydata
, s
->rsakeylen
);
6127 * Next, set up a shared secret K, of precisely KLEN -
6128 * 2*HLEN - 49 bits, where KLEN is the bit length of the
6129 * RSA key modulus and HLEN is the bit length of the hash
6133 int klen
= ssh_rsakex_klen(s
->rsakey
);
6134 int nbits
= klen
- (2*ssh
->kex
->hash
->hlen
*8 + 49);
6136 unsigned char *kstr1
, *kstr2
, *outstr
;
6137 int kstr1len
, kstr2len
, outstrlen
;
6139 s
->K
= bn_power_2(nbits
- 1);
6141 for (i
= 0; i
< nbits
; i
++) {
6143 byte
= random_byte();
6145 bignum_set_bit(s
->K
, i
, (byte
>> (i
& 7)) & 1);
6149 * Encode this as an mpint.
6151 kstr1
= ssh2_mpint_fmt(s
->K
, &kstr1len
);
6152 kstr2
= snewn(kstr2len
= 4 + kstr1len
, unsigned char);
6153 PUT_32BIT(kstr2
, kstr1len
);
6154 memcpy(kstr2
+ 4, kstr1
, kstr1len
);
6157 * Encrypt it with the given RSA key.
6159 outstrlen
= (klen
+ 7) / 8;
6160 outstr
= snewn(outstrlen
, unsigned char);
6161 ssh_rsakex_encrypt(ssh
->kex
->hash
, kstr2
, kstr2len
,
6162 outstr
, outstrlen
, s
->rsakey
);
6165 * And send it off in a return packet.
6167 s
->pktout
= ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET
);
6168 ssh2_pkt_addstring_start(s
->pktout
);
6169 ssh2_pkt_addstring_data(s
->pktout
, (char *)outstr
, outstrlen
);
6170 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6172 hash_string(ssh
->kex
->hash
, ssh
->exhash
, outstr
, outstrlen
);
6179 ssh_rsakex_freekey(s
->rsakey
);
6182 if (pktin
->type
!= SSH2_MSG_KEXRSA_DONE
) {
6183 sfree(s
->rsakeydata
);
6184 bombout(("expected signature packet from server"));
6188 ssh_pkt_getstring(pktin
, &s
->sigdata
, &s
->siglen
);
6190 sfree(s
->rsakeydata
);
6193 hash_mpint(ssh
->kex
->hash
, ssh
->exhash
, s
->K
);
6194 assert(ssh
->kex
->hash
->hlen
<= sizeof(s
->exchange_hash
));
6195 ssh
->kex
->hash
->final(ssh
->exhash
, s
->exchange_hash
);
6197 ssh
->kex_ctx
= NULL
;
6200 debug(("Exchange hash is:\n"));
6201 dmemdump(s
->exchange_hash
, ssh
->kex
->hash
->hlen
);
6205 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
6206 (char *)s
->exchange_hash
,
6207 ssh
->kex
->hash
->hlen
)) {
6208 bombout(("Server's host key did not match the signature supplied"));
6213 * Authenticate remote host: verify host key. (We've already
6214 * checked the signature of the exchange hash.)
6216 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
6217 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
6218 ssh_set_frozen(ssh
, 1);
6219 s
->dlgret
= verify_ssh_host_key(ssh
->frontend
,
6220 ssh
->savedhost
, ssh
->savedport
,
6221 ssh
->hostkey
->keytype
, s
->keystr
,
6223 ssh_dialog_callback
, ssh
);
6224 if (s
->dlgret
< 0) {
6228 bombout(("Unexpected data from server while waiting"
6229 " for user host key response"));
6232 } while (pktin
|| inlen
> 0);
6233 s
->dlgret
= ssh
->user_response
;
6235 ssh_set_frozen(ssh
, 0);
6236 if (s
->dlgret
== 0) {
6237 ssh_disconnect(ssh
, "User aborted at host key verification", NULL
,
6241 if (!s
->got_session_id
) { /* don't bother logging this in rekeys */
6242 logevent("Host key fingerprint is:");
6243 logevent(s
->fingerprint
);
6245 sfree(s
->fingerprint
);
6247 ssh
->hostkey
->freekey(s
->hkey
);
6250 * The exchange hash from the very first key exchange is also
6251 * the session id, used in session key construction and
6254 if (!s
->got_session_id
) {
6255 assert(sizeof(s
->exchange_hash
) <= sizeof(ssh
->v2_session_id
));
6256 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
6257 sizeof(s
->exchange_hash
));
6258 ssh
->v2_session_id_len
= ssh
->kex
->hash
->hlen
;
6259 assert(ssh
->v2_session_id_len
<= sizeof(ssh
->v2_session_id
));
6260 s
->got_session_id
= TRUE
;
6264 * Send SSH2_MSG_NEWKEYS.
6266 s
->pktout
= ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
6267 ssh2_pkt_send_noqueue(ssh
, s
->pktout
);
6268 ssh
->outgoing_data_size
= 0; /* start counting from here */
6271 * We've sent client NEWKEYS, so create and initialise
6272 * client-to-server session keys.
6274 if (ssh
->cs_cipher_ctx
)
6275 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
6276 ssh
->cscipher
= s
->cscipher_tobe
;
6277 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
6279 if (ssh
->cs_mac_ctx
)
6280 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
6281 ssh
->csmac
= s
->csmac_tobe
;
6282 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
6284 if (ssh
->cs_comp_ctx
)
6285 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
6286 ssh
->cscomp
= s
->cscomp_tobe
;
6287 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
6290 * Set IVs on client-to-server keys. Here we use the exchange
6291 * hash from the _first_ key exchange.
6294 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6295 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6296 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'C',keyspace
);
6297 assert((ssh
->cscipher
->keylen
+7) / 8 <=
6298 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6299 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
6300 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'A',keyspace
);
6301 assert(ssh
->cscipher
->blksize
<=
6302 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6303 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
6304 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'E',keyspace
);
6305 assert(ssh
->csmac
->len
<=
6306 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6307 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
6308 smemclr(keyspace
, sizeof(keyspace
));
6311 logeventf(ssh
, "Initialised %.200s client->server encryption",
6312 ssh
->cscipher
->text_name
);
6313 logeventf(ssh
, "Initialised %.200s client->server MAC algorithm",
6314 ssh
->csmac
->text_name
);
6315 if (ssh
->cscomp
->text_name
)
6316 logeventf(ssh
, "Initialised %s compression",
6317 ssh
->cscomp
->text_name
);
6320 * Now our end of the key exchange is complete, we can send all
6321 * our queued higher-layer packets.
6323 ssh
->queueing
= FALSE
;
6324 ssh2_pkt_queuesend(ssh
);
6327 * Expect SSH2_MSG_NEWKEYS from server.
6330 if (pktin
->type
!= SSH2_MSG_NEWKEYS
) {
6331 bombout(("expected new-keys packet from server"));
6334 ssh
->incoming_data_size
= 0; /* start counting from here */
6337 * We've seen server NEWKEYS, so create and initialise
6338 * server-to-client session keys.
6340 if (ssh
->sc_cipher_ctx
)
6341 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
6342 ssh
->sccipher
= s
->sccipher_tobe
;
6343 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
6345 if (ssh
->sc_mac_ctx
)
6346 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
6347 ssh
->scmac
= s
->scmac_tobe
;
6348 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
6350 if (ssh
->sc_comp_ctx
)
6351 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
6352 ssh
->sccomp
= s
->sccomp_tobe
;
6353 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
6356 * Set IVs on server-to-client keys. Here we use the exchange
6357 * hash from the _first_ key exchange.
6360 unsigned char keyspace
[SSH2_KEX_MAX_HASH_LEN
* SSH2_MKKEY_ITERS
];
6361 assert(sizeof(keyspace
) >= ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6362 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'D',keyspace
);
6363 assert((ssh
->sccipher
->keylen
+7) / 8 <=
6364 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6365 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
6366 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'B',keyspace
);
6367 assert(ssh
->sccipher
->blksize
<=
6368 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6369 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
6370 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,'F',keyspace
);
6371 assert(ssh
->scmac
->len
<=
6372 ssh
->kex
->hash
->hlen
* SSH2_MKKEY_ITERS
);
6373 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
6374 smemclr(keyspace
, sizeof(keyspace
));
6376 logeventf(ssh
, "Initialised %.200s server->client encryption",
6377 ssh
->sccipher
->text_name
);
6378 logeventf(ssh
, "Initialised %.200s server->client MAC algorithm",
6379 ssh
->scmac
->text_name
);
6380 if (ssh
->sccomp
->text_name
)
6381 logeventf(ssh
, "Initialised %s decompression",
6382 ssh
->sccomp
->text_name
);
6385 * Free shared secret.
6390 * Key exchange is over. Loop straight back round if we have a
6391 * deferred rekey reason.
6393 if (ssh
->deferred_rekey_reason
) {
6394 logevent(ssh
->deferred_rekey_reason
);
6396 ssh
->deferred_rekey_reason
= NULL
;
6397 goto begin_key_exchange
;
6401 * Otherwise, schedule a timer for our next rekey.
6403 ssh
->kex_in_progress
= FALSE
;
6404 ssh
->last_rekey
= GETTICKCOUNT();
6405 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0)
6406 ssh
->next_rekey
= schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6410 * If this is the first key exchange phase, we must pass the
6411 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6412 * wants to see it but because it will need time to initialise
6413 * itself before it sees an actual packet. In subsequent key
6414 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6415 * it would only confuse the layer above.
6417 if (s
->activated_authconn
) {
6420 s
->activated_authconn
= TRUE
;
6423 * Now we're encrypting. Begin returning 1 to the protocol main
6424 * function so that other things can run on top of the
6425 * transport. If we ever see a KEXINIT, we must go back to the
6428 * We _also_ go back to the start if we see pktin==NULL and
6429 * inlen negative, because this is a special signal meaning
6430 * `initiate client-driven rekey', and `in' contains a message
6431 * giving the reason for the rekey.
6433 * inlen==-1 means always initiate a rekey;
6434 * inlen==-2 means that userauth has completed successfully and
6435 * we should consider rekeying (for delayed compression).
6437 while (!((pktin
&& pktin
->type
== SSH2_MSG_KEXINIT
) ||
6438 (!pktin
&& inlen
< 0))) {
6443 logevent("Server initiated key re-exchange");
6447 * authconn has seen a USERAUTH_SUCCEEDED. Time to enable
6448 * delayed compression, if it's available.
6450 * draft-miller-secsh-compression-delayed-00 says that you
6451 * negotiate delayed compression in the first key exchange, and
6452 * both sides start compressing when the server has sent
6453 * USERAUTH_SUCCESS. This has a race condition -- the server
6454 * can't know when the client has seen it, and thus which incoming
6455 * packets it should treat as compressed.
6457 * Instead, we do the initial key exchange without offering the
6458 * delayed methods, but note if the server offers them; when we
6459 * get here, if a delayed method was available that was higher
6460 * on our list than what we got, we initiate a rekey in which we
6461 * _do_ list the delayed methods (and hopefully get it as a
6462 * result). Subsequent rekeys will do the same.
6464 assert(!s
->userauth_succeeded
); /* should only happen once */
6465 s
->userauth_succeeded
= TRUE
;
6466 if (!s
->pending_compression
)
6467 /* Can't see any point rekeying. */
6468 goto wait_for_rekey
; /* this is utterly horrid */
6469 /* else fall through to rekey... */
6470 s
->pending_compression
= FALSE
;
6473 * Now we've decided to rekey.
6475 * Special case: if the server bug is set that doesn't
6476 * allow rekeying, we give a different log message and
6477 * continue waiting. (If such a server _initiates_ a rekey,
6478 * we process it anyway!)
6480 if ((ssh
->remote_bugs
& BUG_SSH2_REKEY
)) {
6481 logeventf(ssh
, "Server bug prevents key re-exchange (%s)",
6483 /* Reset the counters, so that at least this message doesn't
6484 * hit the event log _too_ often. */
6485 ssh
->outgoing_data_size
= 0;
6486 ssh
->incoming_data_size
= 0;
6487 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0) {
6489 schedule_timer(conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
)*60*TICKSPERSEC
,
6492 goto wait_for_rekey
; /* this is still utterly horrid */
6494 logeventf(ssh
, "Initiating key re-exchange (%s)", (char *)in
);
6497 goto begin_key_exchange
;
6503 * Add data to an SSH-2 channel output buffer.
6505 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
6508 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
6512 * Attempt to send data on an SSH-2 channel.
6514 static int ssh2_try_send(struct ssh_channel
*c
)
6517 struct Packet
*pktout
;
6520 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
6523 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
6524 if ((unsigned)len
> c
->v
.v2
.remwindow
)
6525 len
= c
->v
.v2
.remwindow
;
6526 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
6527 len
= c
->v
.v2
.remmaxpkt
;
6528 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
6529 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6530 ssh2_pkt_addstring_start(pktout
);
6531 dont_log_data(ssh
, pktout
, PKTLOG_OMIT
);
6532 ssh2_pkt_addstring_data(pktout
, data
, len
);
6533 end_log_omission(ssh
, pktout
);
6534 ssh2_pkt_send(ssh
, pktout
);
6535 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
6536 c
->v
.v2
.remwindow
-= len
;
6540 * After having sent as much data as we can, return the amount
6543 ret
= bufchain_size(&c
->v
.v2
.outbuffer
);
6546 * And if there's no data pending but we need to send an EOF, send
6549 if (!ret
&& c
->pending_eof
)
6550 ssh_channel_try_eof(c
);
6555 static void ssh2_try_send_and_unthrottle(Ssh ssh
, struct ssh_channel
*c
)
6558 if (c
->closes
& CLOSES_SENT_EOF
)
6559 return; /* don't send on channels we've EOFed */
6560 bufsize
= ssh2_try_send(c
);
6563 case CHAN_MAINSESSION
:
6564 /* stdin need not receive an unthrottle
6565 * notification since it will be polled */
6568 x11_unthrottle(c
->u
.x11
.s
);
6571 /* agent sockets are request/response and need no
6572 * buffer management */
6575 pfd_unthrottle(c
->u
.pfd
.s
);
6582 * Set up most of a new ssh_channel for SSH-2.
6584 static void ssh2_channel_init(struct ssh_channel
*c
)
6587 c
->localid
= alloc_channel_id(ssh
);
6589 c
->pending_eof
= FALSE
;
6590 c
->throttling_conn
= FALSE
;
6591 c
->v
.v2
.locwindow
= c
->v
.v2
.locmaxwin
= c
->v
.v2
.remlocwin
=
6592 conf_get_int(ssh
->conf
, CONF_ssh_simple
) ? OUR_V2_BIGWIN
: OUR_V2_WINSIZE
;
6593 c
->v
.v2
.winadj_head
= c
->v
.v2
.winadj_tail
= NULL
;
6594 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6595 bufchain_init(&c
->v
.v2
.outbuffer
);
6599 * Potentially enlarge the window on an SSH-2 channel.
6601 static void ssh2_set_window(struct ssh_channel
*c
, int newwin
)
6606 * Never send WINDOW_ADJUST for a channel that the remote side has
6607 * already sent EOF on; there's no point, since it won't be
6608 * sending any more data anyway. Ditto if _we've_ already sent
6611 if (c
->closes
& (CLOSES_RCVD_EOF
| CLOSES_SENT_CLOSE
))
6615 * If the remote end has a habit of ignoring maxpkt, limit the
6616 * window so that it has no choice (assuming it doesn't ignore the
6619 if ((ssh
->remote_bugs
& BUG_SSH2_MAXPKT
) && newwin
> OUR_V2_MAXPKT
)
6620 newwin
= OUR_V2_MAXPKT
;
6623 * Only send a WINDOW_ADJUST if there's significantly more window
6624 * available than the other end thinks there is. This saves us
6625 * sending a WINDOW_ADJUST for every character in a shell session.
6627 * "Significant" is arbitrarily defined as half the window size.
6629 if (newwin
/ 2 >= c
->v
.v2
.locwindow
) {
6630 struct Packet
*pktout
;
6634 * In order to keep track of how much window the client
6635 * actually has available, we'd like it to acknowledge each
6636 * WINDOW_ADJUST. We can't do that directly, so we accompany
6637 * it with a CHANNEL_REQUEST that has to be acknowledged.
6639 * This is only necessary if we're opening the window wide.
6640 * If we're not, then throughput is being constrained by
6641 * something other than the maximum window size anyway.
6643 * We also only send this if the main channel has finished its
6644 * initial CHANNEL_REQUESTs and installed the default
6645 * CHANNEL_FAILURE handler, so as not to risk giving it
6646 * unexpected CHANNEL_FAILUREs.
6648 if (newwin
== c
->v
.v2
.locmaxwin
&&
6649 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] &&
6650 !(ssh
->remote_bugs
& BUG_CHOKES_ON_WINADJ
)) {
6651 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
6652 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6653 ssh2_pkt_addstring(pktout
, "winadj@putty.projects.tartarus.org");
6654 ssh2_pkt_addbool(pktout
, TRUE
);
6655 ssh2_pkt_send(ssh
, pktout
);
6658 * CHANNEL_FAILURE doesn't come with any indication of
6659 * what message caused it, so we have to keep track of the
6660 * outstanding CHANNEL_REQUESTs ourselves.
6662 wa
= snew(struct winadj
);
6663 wa
->size
= newwin
- c
->v
.v2
.locwindow
;
6665 if (!c
->v
.v2
.winadj_head
)
6666 c
->v
.v2
.winadj_head
= wa
;
6668 c
->v
.v2
.winadj_tail
->next
= wa
;
6669 c
->v
.v2
.winadj_tail
= wa
;
6670 if (c
->v
.v2
.throttle_state
!= UNTHROTTLED
)
6671 c
->v
.v2
.throttle_state
= UNTHROTTLING
;
6673 /* Pretend the WINDOW_ADJUST was acked immediately. */
6674 c
->v
.v2
.remlocwin
= newwin
;
6675 c
->v
.v2
.throttle_state
= THROTTLED
;
6677 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
6678 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6679 ssh2_pkt_adduint32(pktout
, newwin
- c
->v
.v2
.locwindow
);
6680 ssh2_pkt_send(ssh
, pktout
);
6681 c
->v
.v2
.locwindow
= newwin
;
6686 * Find the channel associated with a message. If there's no channel,
6687 * or it's not properly open, make a noise about it and return NULL.
6689 static struct ssh_channel
*ssh2_channel_msg(Ssh ssh
, struct Packet
*pktin
)
6691 unsigned localid
= ssh_pkt_getuint32(pktin
);
6692 struct ssh_channel
*c
;
6694 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
6696 (c
->halfopen
&& pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
&&
6697 pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_FAILURE
)) {
6698 char *buf
= dupprintf("Received %s for %s channel %u",
6699 ssh2_pkt_type(ssh
->pkt_kctx
, ssh
->pkt_actx
,
6701 c ?
"half-open" : "nonexistent", localid
);
6702 ssh_disconnect(ssh
, NULL
, buf
, SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6709 static int ssh2_handle_winadj_response(struct ssh_channel
*c
)
6711 struct winadj
*wa
= c
->v
.v2
.winadj_head
;
6714 c
->v
.v2
.winadj_head
= wa
->next
;
6715 c
->v
.v2
.remlocwin
+= wa
->size
;
6718 * winadj messages are only sent when the window is fully open, so
6719 * if we get an ack of one, we know any pending unthrottle is
6722 if (c
->v
.v2
.throttle_state
== UNTHROTTLING
)
6723 c
->v
.v2
.throttle_state
= UNTHROTTLED
;
6725 * We may now initiate channel-closing procedures, if that winadj
6726 * was the last thing outstanding before we send CHANNEL_CLOSE.
6728 ssh2_channel_check_close(c
);
6732 static void ssh2_msg_channel_success(Ssh ssh
, struct Packet
*pktin
)
6735 * This should never get called. All channel requests are either
6736 * sent with want_reply false, are sent before this handler gets
6737 * installed, or are "winadj@putty" requests, which servers should
6738 * never respond to with success.
6740 * However, at least one server ("boks_sshd") is known to return
6741 * SUCCESS for channel requests it's never heard of, such as
6742 * "winadj@putty". Raised with foxt.com as bug 090916-090424, but
6743 * for the sake of a quiet life, we handle it just the same as the
6746 struct ssh_channel
*c
;
6748 c
= ssh2_channel_msg(ssh
, pktin
);
6751 if (!ssh2_handle_winadj_response(c
))
6752 ssh_disconnect(ssh
, NULL
,
6753 "Received unsolicited SSH_MSG_CHANNEL_SUCCESS",
6754 SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6757 static void ssh2_msg_channel_failure(Ssh ssh
, struct Packet
*pktin
)
6760 * The only time this should get called is for "winadj@putty"
6761 * messages sent above. All other channel requests are either
6762 * sent with want_reply false or are sent before this handler gets
6765 struct ssh_channel
*c
;
6767 c
= ssh2_channel_msg(ssh
, pktin
);
6770 if (!ssh2_handle_winadj_response(c
))
6771 ssh_disconnect(ssh
, NULL
,
6772 "Received unsolicited SSH_MSG_CHANNEL_FAILURE",
6773 SSH2_DISCONNECT_PROTOCOL_ERROR
, FALSE
);
6776 static void ssh2_msg_channel_window_adjust(Ssh ssh
, struct Packet
*pktin
)
6778 struct ssh_channel
*c
;
6779 c
= ssh2_channel_msg(ssh
, pktin
);
6782 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
6783 c
->v
.v2
.remwindow
+= ssh_pkt_getuint32(pktin
);
6784 ssh2_try_send_and_unthrottle(ssh
, c
);
6788 static void ssh2_msg_channel_data(Ssh ssh
, struct Packet
*pktin
)
6792 struct ssh_channel
*c
;
6793 c
= ssh2_channel_msg(ssh
, pktin
);
6796 if (pktin
->type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
6797 ssh_pkt_getuint32(pktin
) != SSH2_EXTENDED_DATA_STDERR
)
6798 return; /* extended but not stderr */
6799 ssh_pkt_getstring(pktin
, &data
, &length
);
6802 c
->v
.v2
.locwindow
-= length
;
6803 c
->v
.v2
.remlocwin
-= length
;
6805 case CHAN_MAINSESSION
:
6807 from_backend(ssh
->frontend
, pktin
->type
==
6808 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
6812 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
6815 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
6818 while (length
> 0) {
6819 if (c
->u
.a
.lensofar
< 4) {
6820 unsigned int l
= min(4 - c
->u
.a
.lensofar
,
6822 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
6826 c
->u
.a
.lensofar
+= l
;
6828 if (c
->u
.a
.lensofar
== 4) {
6830 4 + GET_32BIT(c
->u
.a
.msglen
);
6831 c
->u
.a
.message
= snewn(c
->u
.a
.totallen
,
6833 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
6835 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
6837 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
6839 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
6843 c
->u
.a
.lensofar
+= l
;
6845 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
6848 if (agent_query(c
->u
.a
.message
,
6851 ssh_agentf_callback
, c
))
6852 ssh_agentf_callback(c
, reply
, replylen
);
6853 sfree(c
->u
.a
.message
);
6854 c
->u
.a
.message
= NULL
;
6855 c
->u
.a
.lensofar
= 0;
6862 * If it looks like the remote end hit the end of its window,
6863 * and we didn't want it to do that, think about using a
6866 if (c
->v
.v2
.remlocwin
<= 0 && c
->v
.v2
.throttle_state
== UNTHROTTLED
&&
6867 c
->v
.v2
.locmaxwin
< 0x40000000)
6868 c
->v
.v2
.locmaxwin
+= OUR_V2_WINSIZE
;
6870 * If we are not buffering too much data,
6871 * enlarge the window again at the remote side.
6872 * If we are buffering too much, we may still
6873 * need to adjust the window if the server's
6876 ssh2_set_window(c
, bufsize
< c
->v
.v2
.locmaxwin ?
6877 c
->v
.v2
.locmaxwin
- bufsize
: 0);
6879 * If we're either buffering way too much data, or if we're
6880 * buffering anything at all and we're in "simple" mode,
6881 * throttle the whole channel.
6883 if ((bufsize
> c
->v
.v2
.locmaxwin
||
6884 (conf_get_int(ssh
->conf
, CONF_ssh_simple
) && bufsize
> 0)) &&
6885 !c
->throttling_conn
) {
6886 c
->throttling_conn
= 1;
6887 ssh_throttle_conn(ssh
, +1);
6892 static void ssh_channel_destroy(struct ssh_channel
*c
)
6897 case CHAN_MAINSESSION
:
6898 ssh
->mainchan
= NULL
;
6899 update_specials_menu(ssh
->frontend
);
6902 if (c
->u
.x11
.s
!= NULL
)
6903 x11_close(c
->u
.x11
.s
);
6904 logevent("Forwarded X11 connection terminated");
6907 sfree(c
->u
.a
.message
);
6910 if (c
->u
.pfd
.s
!= NULL
)
6911 pfd_close(c
->u
.pfd
.s
);
6912 logevent("Forwarded port closed");
6916 del234(ssh
->channels
, c
);
6917 if (ssh
->version
== 2)
6918 bufchain_clear(&c
->v
.v2
.outbuffer
);
6922 * See if that was the last channel left open.
6923 * (This is only our termination condition if we're
6924 * not running in -N mode.)
6926 if (ssh
->version
== 2 &&
6927 !conf_get_int(ssh
->conf
, CONF_ssh_no_shell
) &&
6928 count234(ssh
->channels
) == 0) {
6930 * We used to send SSH_MSG_DISCONNECT here,
6931 * because I'd believed that _every_ conforming
6932 * SSH-2 connection had to end with a disconnect
6933 * being sent by at least one side; apparently
6934 * I was wrong and it's perfectly OK to
6935 * unceremoniously slam the connection shut
6936 * when you're done, and indeed OpenSSH feels
6937 * this is more polite than sending a
6938 * DISCONNECT. So now we don't.
6940 ssh_disconnect(ssh
, "All channels closed", NULL
, 0, TRUE
);
6944 static void ssh2_channel_check_close(struct ssh_channel
*c
)
6947 struct Packet
*pktout
;
6949 if ((c
->closes
& (CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
| CLOSES_SENT_CLOSE
))
6950 == (CLOSES_SENT_EOF
| CLOSES_RCVD_EOF
) && !c
->v
.v2
.winadj_head
) {
6952 * We have both sent and received EOF, and we have no
6953 * outstanding winadj channel requests, which means the
6954 * channel is in final wind-up. But we haven't sent CLOSE, so
6957 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
6958 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
6959 ssh2_pkt_send(ssh
, pktout
);
6960 c
->closes
|= CLOSES_SENT_CLOSE
;
6963 if (!((CLOSES_SENT_CLOSE
| CLOSES_RCVD_CLOSE
) & ~c
->closes
)) {
6965 * We have both sent and received CLOSE, which means we're
6966 * completely done with the channel.
6968 ssh_channel_destroy(c
);
6972 static void ssh2_channel_got_eof(struct ssh_channel
*c
)
6974 if (c
->closes
& CLOSES_RCVD_EOF
)
6975 return; /* already seen EOF */
6976 c
->closes
|= CLOSES_RCVD_EOF
;
6978 if (c
->type
== CHAN_X11
) {
6979 x11_send_eof(c
->u
.x11
.s
);
6980 } else if (c
->type
== CHAN_AGENT
) {
6981 /* Manufacture an outgoing EOF in response to the incoming one. */
6982 sshfwd_write_eof(c
);
6983 } else if (c
->type
== CHAN_SOCKDATA
) {
6984 pfd_send_eof(c
->u
.pfd
.s
);
6985 } else if (c
->type
== CHAN_MAINSESSION
) {
6988 if (!ssh
->sent_console_eof
&&
6989 (from_backend_eof(ssh
->frontend
) || ssh
->got_pty
)) {
6991 * Either from_backend_eof told us that the front end
6992 * wants us to close the outgoing side of the connection
6993 * as soon as we see EOF from the far end, or else we've
6994 * unilaterally decided to do that because we've allocated
6995 * a remote pty and hence EOF isn't a particularly
6996 * meaningful concept.
6998 sshfwd_write_eof(c
);
7000 ssh
->sent_console_eof
= TRUE
;
7003 ssh2_channel_check_close(c
);
7006 static void ssh2_msg_channel_eof(Ssh ssh
, struct Packet
*pktin
)
7008 struct ssh_channel
*c
;
7010 c
= ssh2_channel_msg(ssh
, pktin
);
7013 ssh2_channel_got_eof(c
);
7016 static void ssh2_msg_channel_close(Ssh ssh
, struct Packet
*pktin
)
7018 struct ssh_channel
*c
;
7020 c
= ssh2_channel_msg(ssh
, pktin
);
7025 * When we receive CLOSE on a channel, we assume it comes with an
7026 * implied EOF if we haven't seen EOF yet.
7028 ssh2_channel_got_eof(c
);
7031 * And we also send an outgoing EOF, if we haven't already, on the
7032 * assumption that CLOSE is a pretty forceful announcement that
7033 * the remote side is doing away with the entire channel. (If it
7034 * had wanted to send us EOF and continue receiving data from us,
7035 * it would have just sent CHANNEL_EOF.)
7037 if (!(c
->closes
& CLOSES_SENT_EOF
)) {
7039 * Make sure we don't read any more from whatever our local
7040 * data source is for this channel.
7043 case CHAN_MAINSESSION
:
7044 ssh
->send_ok
= 0; /* stop trying to read from stdin */
7047 x11_override_throttle(c
->u
.x11
.s
, 1);
7050 pfd_override_throttle(c
->u
.pfd
.s
, 1);
7055 * Send outgoing EOF.
7057 sshfwd_write_eof(c
);
7061 * Now process the actual close.
7063 if (!(c
->closes
& CLOSES_RCVD_CLOSE
)) {
7064 c
->closes
|= CLOSES_RCVD_CLOSE
;
7065 ssh2_channel_check_close(c
);
7069 static void ssh2_msg_channel_open_confirmation(Ssh ssh
, struct Packet
*pktin
)
7071 struct ssh_channel
*c
;
7073 c
= ssh2_channel_msg(ssh
, pktin
);
7076 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7077 return; /* dunno why they're confirming this */
7078 c
->remoteid
= ssh_pkt_getuint32(pktin
);
7079 c
->halfopen
= FALSE
;
7080 c
->type
= CHAN_SOCKDATA
;
7081 c
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
7082 c
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
7084 pfd_confirm(c
->u
.pfd
.s
);
7086 ssh_channel_try_eof(c
);
7089 static void ssh2_msg_channel_open_failure(Ssh ssh
, struct Packet
*pktin
)
7091 static const char *const reasons
[] = {
7092 "<unknown reason code>",
7093 "Administratively prohibited",
7095 "Unknown channel type",
7096 "Resource shortage",
7098 unsigned reason_code
;
7099 char *reason_string
;
7101 struct ssh_channel
*c
;
7102 c
= ssh2_channel_msg(ssh
, pktin
);
7105 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
7106 return; /* dunno why they're failing this */
7108 reason_code
= ssh_pkt_getuint32(pktin
);
7109 if (reason_code
>= lenof(reasons
))
7110 reason_code
= 0; /* ensure reasons[reason_code] in range */
7111 ssh_pkt_getstring(pktin
, &reason_string
, &reason_length
);
7112 logeventf(ssh
, "Forwarded connection refused by server: %s [%.*s]",
7113 reasons
[reason_code
], reason_length
, reason_string
);
7115 pfd_close(c
->u
.pfd
.s
);
7117 del234(ssh
->channels
, c
);
7121 static void ssh2_msg_channel_request(Ssh ssh
, struct Packet
*pktin
)
7124 int typelen
, want_reply
;
7125 int reply
= SSH2_MSG_CHANNEL_FAILURE
; /* default */
7126 struct ssh_channel
*c
;
7127 struct Packet
*pktout
;
7129 c
= ssh2_channel_msg(ssh
, pktin
);
7132 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7133 want_reply
= ssh2_pkt_getbool(pktin
);
7136 * Having got the channel number, we now look at
7137 * the request type string to see if it's something
7140 if (c
== ssh
->mainchan
) {
7142 * We recognise "exit-status" and "exit-signal" on
7143 * the primary channel.
7145 if (typelen
== 11 &&
7146 !memcmp(type
, "exit-status", 11)) {
7148 ssh
->exitcode
= ssh_pkt_getuint32(pktin
);
7149 logeventf(ssh
, "Server sent command exit status %d",
7151 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7153 } else if (typelen
== 11 &&
7154 !memcmp(type
, "exit-signal", 11)) {
7156 int is_plausible
= TRUE
, is_int
= FALSE
;
7157 char *fmt_sig
= "", *fmt_msg
= "";
7159 int msglen
= 0, core
= FALSE
;
7160 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
7161 * provide an `int' for the signal, despite its
7162 * having been a `string' in the drafts of RFC 4254 since at
7163 * least 2001. (Fixed in session.c 1.147.) Try to
7164 * infer which we can safely parse it as. */
7166 unsigned char *p
= pktin
->body
+
7168 long len
= pktin
->length
- pktin
->savedpos
;
7169 unsigned long num
= GET_32BIT(p
); /* what is it? */
7170 /* If it's 0, it hardly matters; assume string */
7174 int maybe_int
= FALSE
, maybe_str
= FALSE
;
7175 #define CHECK_HYPOTHESIS(offset, result) \
7178 if (q >= 0 && q+4 <= len) { \
7179 q = q + 4 + GET_32BIT(p+q); \
7180 if (q >= 0 && q+4 <= len && \
7181 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
7185 CHECK_HYPOTHESIS(4+1, maybe_int
);
7186 CHECK_HYPOTHESIS(4+num
+1, maybe_str
);
7187 #undef CHECK_HYPOTHESIS
7188 if (maybe_int
&& !maybe_str
)
7190 else if (!maybe_int
&& maybe_str
)
7193 /* Crikey. Either or neither. Panic. */
7194 is_plausible
= FALSE
;
7197 ssh
->exitcode
= 128; /* means `unknown signal' */
7200 /* Old non-standard OpenSSH. */
7201 int signum
= ssh_pkt_getuint32(pktin
);
7202 fmt_sig
= dupprintf(" %d", signum
);
7203 ssh
->exitcode
= 128 + signum
;
7205 /* As per RFC 4254. */
7208 ssh_pkt_getstring(pktin
, &sig
, &siglen
);
7209 /* Signal name isn't supposed to be blank, but
7210 * let's cope gracefully if it is. */
7212 fmt_sig
= dupprintf(" \"%.*s\"",
7217 * Really hideous method of translating the
7218 * signal description back into a locally
7219 * meaningful number.
7224 #define TRANSLATE_SIGNAL(s) \
7225 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
7226 ssh->exitcode = 128 + SIG ## s
7228 TRANSLATE_SIGNAL(ABRT
);
7231 TRANSLATE_SIGNAL(ALRM
);
7234 TRANSLATE_SIGNAL(FPE
);
7237 TRANSLATE_SIGNAL(HUP
);
7240 TRANSLATE_SIGNAL(ILL
);
7243 TRANSLATE_SIGNAL(INT
);
7246 TRANSLATE_SIGNAL(KILL
);
7249 TRANSLATE_SIGNAL(PIPE
);
7252 TRANSLATE_SIGNAL(QUIT
);
7255 TRANSLATE_SIGNAL(SEGV
);
7258 TRANSLATE_SIGNAL(TERM
);
7261 TRANSLATE_SIGNAL(USR1
);
7264 TRANSLATE_SIGNAL(USR2
);
7266 #undef TRANSLATE_SIGNAL
7268 ssh
->exitcode
= 128;
7270 core
= ssh2_pkt_getbool(pktin
);
7271 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
7273 fmt_msg
= dupprintf(" (\"%.*s\")", msglen
, msg
);
7275 /* ignore lang tag */
7276 } /* else don't attempt to parse */
7277 logeventf(ssh
, "Server exited on signal%s%s%s",
7278 fmt_sig
, core ?
" (core dumped)" : "",
7280 if (*fmt_sig
) sfree(fmt_sig
);
7281 if (*fmt_msg
) sfree(fmt_msg
);
7282 reply
= SSH2_MSG_CHANNEL_SUCCESS
;
7287 * This is a channel request we don't know
7288 * about, so we now either ignore the request
7289 * or respond with CHANNEL_FAILURE, depending
7292 reply
= SSH2_MSG_CHANNEL_FAILURE
;
7295 pktout
= ssh2_pkt_init(reply
);
7296 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7297 ssh2_pkt_send(ssh
, pktout
);
7301 static void ssh2_msg_global_request(Ssh ssh
, struct Packet
*pktin
)
7304 int typelen
, want_reply
;
7305 struct Packet
*pktout
;
7307 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7308 want_reply
= ssh2_pkt_getbool(pktin
);
7311 * We currently don't support any global requests
7312 * at all, so we either ignore the request or
7313 * respond with REQUEST_FAILURE, depending on
7317 pktout
= ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
7318 ssh2_pkt_send(ssh
, pktout
);
7322 static void ssh2_msg_channel_open(Ssh ssh
, struct Packet
*pktin
)
7330 struct ssh_channel
*c
;
7331 unsigned remid
, winsize
, pktsize
;
7332 struct Packet
*pktout
;
7334 ssh_pkt_getstring(pktin
, &type
, &typelen
);
7335 c
= snew(struct ssh_channel
);
7338 remid
= ssh_pkt_getuint32(pktin
);
7339 winsize
= ssh_pkt_getuint32(pktin
);
7340 pktsize
= ssh_pkt_getuint32(pktin
);
7342 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
7346 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7347 addrstr
= snewn(peeraddrlen
+1, char);
7348 memcpy(addrstr
, peeraddr
, peeraddrlen
);
7349 addrstr
[peeraddrlen
] = '\0';
7350 peerport
= ssh_pkt_getuint32(pktin
);
7352 logeventf(ssh
, "Received X11 connect request from %s:%d",
7355 if (!ssh
->X11_fwd_enabled
)
7356 error
= "X11 forwarding is not enabled";
7357 else if ((x11err
= x11_init(&c
->u
.x11
.s
, ssh
->x11disp
, c
,
7358 addrstr
, peerport
, ssh
->conf
)) != NULL
) {
7359 logeventf(ssh
, "Local X11 connection failed: %s", x11err
);
7360 error
= "Unable to open an X11 connection";
7362 logevent("Opening X11 forward connection succeeded");
7367 } else if (typelen
== 15 &&
7368 !memcmp(type
, "forwarded-tcpip", 15)) {
7369 struct ssh_rportfwd pf
, *realpf
;
7372 ssh_pkt_getstring(pktin
, &dummy
, &dummylen
);/* skip address */
7373 pf
.sport
= ssh_pkt_getuint32(pktin
);
7374 ssh_pkt_getstring(pktin
, &peeraddr
, &peeraddrlen
);
7375 peerport
= ssh_pkt_getuint32(pktin
);
7376 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
7377 logeventf(ssh
, "Received remote port %d open request "
7378 "from %s:%d", pf
.sport
, peeraddr
, peerport
);
7379 if (realpf
== NULL
) {
7380 error
= "Remote port is not recognised";
7382 const char *e
= pfd_newconnect(&c
->u
.pfd
.s
,
7386 realpf
->pfrec
->addressfamily
);
7387 logeventf(ssh
, "Attempting to forward remote port to "
7388 "%s:%d", realpf
->dhost
, realpf
->dport
);
7390 logeventf(ssh
, "Port open failed: %s", e
);
7391 error
= "Port open failed";
7393 logevent("Forwarded port opened successfully");
7394 c
->type
= CHAN_SOCKDATA
;
7397 } else if (typelen
== 22 &&
7398 !memcmp(type
, "auth-agent@openssh.com", 22)) {
7399 if (!ssh
->agentfwd_enabled
)
7400 error
= "Agent forwarding is not enabled";
7402 c
->type
= CHAN_AGENT
; /* identify channel type */
7403 c
->u
.a
.lensofar
= 0;
7406 error
= "Unsupported channel type requested";
7409 c
->remoteid
= remid
;
7410 c
->halfopen
= FALSE
;
7412 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
7413 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7414 ssh2_pkt_adduint32(pktout
, SSH2_OPEN_CONNECT_FAILED
);
7415 ssh2_pkt_addstring(pktout
, error
);
7416 ssh2_pkt_addstring(pktout
, "en"); /* language tag */
7417 ssh2_pkt_send(ssh
, pktout
);
7418 logeventf(ssh
, "Rejected channel open: %s", error
);
7421 ssh2_channel_init(c
);
7422 c
->v
.v2
.remwindow
= winsize
;
7423 c
->v
.v2
.remmaxpkt
= pktsize
;
7424 add234(ssh
->channels
, c
);
7425 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
7426 ssh2_pkt_adduint32(pktout
, c
->remoteid
);
7427 ssh2_pkt_adduint32(pktout
, c
->localid
);
7428 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);
7429 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
7430 ssh2_pkt_send(ssh
, pktout
);
7435 * Buffer banner messages for later display at some convenient point,
7436 * if we're going to display them.
7438 static void ssh2_msg_userauth_banner(Ssh ssh
, struct Packet
*pktin
)
7440 /* Arbitrary limit to prevent unbounded inflation of buffer */
7441 if (conf_get_int(ssh
->conf
, CONF_ssh_show_banner
) &&
7442 bufchain_size(&ssh
->banner
) <= 131072) {
7443 char *banner
= NULL
;
7445 ssh_pkt_getstring(pktin
, &banner
, &size
);
7447 bufchain_add(&ssh
->banner
, banner
, size
);
7451 /* Helper function to deal with sending tty modes for "pty-req" */
7452 static void ssh2_send_ttymode(void *data
, char *mode
, char *val
)
7454 struct Packet
*pktout
= (struct Packet
*)data
;
7456 unsigned int arg
= 0;
7457 while (strcmp(mode
, ssh_ttymodes
[i
].mode
) != 0) i
++;
7458 if (i
== lenof(ssh_ttymodes
)) return;
7459 switch (ssh_ttymodes
[i
].type
) {
7461 arg
= ssh_tty_parse_specchar(val
);
7464 arg
= ssh_tty_parse_boolean(val
);
7467 ssh2_pkt_addbyte(pktout
, ssh_ttymodes
[i
].opcode
);
7468 ssh2_pkt_adduint32(pktout
, arg
);
7472 * Handle the SSH-2 userauth and connection layers.
7474 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
,
7475 struct Packet
*pktin
)
7477 struct do_ssh2_authconn_state
{
7481 AUTH_TYPE_PUBLICKEY
,
7482 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
7483 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
7485 AUTH_TYPE_GSSAPI
, /* always QUIET */
7486 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
7487 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
7489 int done_service_req
;
7490 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
7491 int tried_pubkey_config
, done_agent
;
7496 int kbd_inter_refused
;
7497 int we_are_in
, userauth_success
;
7498 prompts_t
*cur_prompt
;
7503 void *publickey_blob
;
7504 int publickey_bloblen
;
7505 int publickey_encrypted
;
7506 char *publickey_algorithm
;
7507 char *publickey_comment
;
7508 unsigned char agent_request
[5], *agent_response
, *agentp
;
7509 int agent_responselen
;
7510 unsigned char *pkblob_in_agent
;
7512 char *pkblob
, *alg
, *commentp
;
7513 int pklen
, alglen
, commentlen
;
7514 int siglen
, retlen
, len
;
7515 char *q
, *agentreq
, *ret
;
7518 int requested_agent
;
7520 int num_env
, env_left
, env_ok
;
7521 struct Packet
*pktout
;
7524 struct ssh_gss_library
*gsslib
;
7525 Ssh_gss_ctx gss_ctx
;
7526 Ssh_gss_buf gss_buf
;
7527 Ssh_gss_buf gss_rcvtok
, gss_sndtok
;
7528 Ssh_gss_name gss_srv_name
;
7529 Ssh_gss_stat gss_stat
;
7532 crState(do_ssh2_authconn_state
);
7536 s
->done_service_req
= FALSE
;
7537 s
->we_are_in
= s
->userauth_success
= FALSE
;
7539 s
->tried_gssapi
= FALSE
;
7542 if (!conf_get_int(ssh
->conf
, CONF_ssh_no_userauth
)) {
7544 * Request userauth protocol, and await a response to it.
7546 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7547 ssh2_pkt_addstring(s
->pktout
, "ssh-userauth");
7548 ssh2_pkt_send(ssh
, s
->pktout
);
7549 crWaitUntilV(pktin
);
7550 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
)
7551 s
->done_service_req
= TRUE
;
7553 if (!s
->done_service_req
) {
7555 * Request connection protocol directly, without authentication.
7557 s
->pktout
= ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
7558 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7559 ssh2_pkt_send(ssh
, s
->pktout
);
7560 crWaitUntilV(pktin
);
7561 if (pktin
->type
== SSH2_MSG_SERVICE_ACCEPT
) {
7562 s
->we_are_in
= TRUE
; /* no auth required */
7564 bombout(("Server refused service request"));
7569 /* Arrange to be able to deal with any BANNERs that come in.
7570 * (We do this now as packets may come in during the next bit.) */
7571 bufchain_init(&ssh
->banner
);
7572 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] =
7573 ssh2_msg_userauth_banner
;
7576 * Misc one-time setup for authentication.
7578 s
->publickey_blob
= NULL
;
7579 if (!s
->we_are_in
) {
7582 * Load the public half of any configured public key file
7585 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
7586 if (!filename_is_null(s
->keyfile
)) {
7588 logeventf(ssh
, "Reading private key file \"%.150s\"",
7589 filename_to_str(s
->keyfile
));
7590 keytype
= key_type(s
->keyfile
);
7591 if (keytype
== SSH_KEYTYPE_SSH2
) {
7594 ssh2_userkey_loadpub(s
->keyfile
,
7595 &s
->publickey_algorithm
,
7596 &s
->publickey_bloblen
,
7597 &s
->publickey_comment
, &error
);
7598 if (s
->publickey_blob
) {
7599 s
->publickey_encrypted
=
7600 ssh2_userkey_encrypted(s
->keyfile
, NULL
);
7603 logeventf(ssh
, "Unable to load private key (%s)",
7605 msgbuf
= dupprintf("Unable to load private key file "
7606 "\"%.150s\" (%s)\r\n",
7607 filename_to_str(s
->keyfile
),
7609 c_write_str(ssh
, msgbuf
);
7614 logeventf(ssh
, "Unable to use this key file (%s)",
7615 key_type_to_str(keytype
));
7616 msgbuf
= dupprintf("Unable to use key file \"%.150s\""
7618 filename_to_str(s
->keyfile
),
7619 key_type_to_str(keytype
));
7620 c_write_str(ssh
, msgbuf
);
7622 s
->publickey_blob
= NULL
;
7627 * Find out about any keys Pageant has (but if there's a
7628 * public key configured, filter out all others).
7631 s
->agent_response
= NULL
;
7632 s
->pkblob_in_agent
= NULL
;
7633 if (conf_get_int(ssh
->conf
, CONF_tryagent
) && agent_exists()) {
7637 logevent("Pageant is running. Requesting keys.");
7639 /* Request the keys held by the agent. */
7640 PUT_32BIT(s
->agent_request
, 1);
7641 s
->agent_request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
7642 if (!agent_query(s
->agent_request
, 5, &r
, &s
->agent_responselen
,
7643 ssh_agent_callback
, ssh
)) {
7647 bombout(("Unexpected data from server while"
7648 " waiting for agent response"));
7651 } while (pktin
|| inlen
> 0);
7652 r
= ssh
->agent_response
;
7653 s
->agent_responselen
= ssh
->agent_response_len
;
7655 s
->agent_response
= (unsigned char *) r
;
7656 if (s
->agent_response
&& s
->agent_responselen
>= 5 &&
7657 s
->agent_response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
7660 p
= s
->agent_response
+ 5;
7661 s
->nkeys
= GET_32BIT(p
);
7663 logeventf(ssh
, "Pageant has %d SSH-2 keys", s
->nkeys
);
7664 if (s
->publickey_blob
) {
7665 /* See if configured key is in agent. */
7666 for (keyi
= 0; keyi
< s
->nkeys
; keyi
++) {
7667 s
->pklen
= GET_32BIT(p
);
7668 if (s
->pklen
== s
->publickey_bloblen
&&
7669 !memcmp(p
+4, s
->publickey_blob
,
7670 s
->publickey_bloblen
)) {
7671 logeventf(ssh
, "Pageant key #%d matches "
7672 "configured key file", keyi
);
7674 s
->pkblob_in_agent
= p
;
7678 p
+= GET_32BIT(p
) + 4; /* comment */
7680 if (!s
->pkblob_in_agent
) {
7681 logevent("Configured key file not in Pageant");
7686 logevent("Failed to get reply from Pageant");
7693 * We repeat this whole loop, including the username prompt,
7694 * until we manage a successful authentication. If the user
7695 * types the wrong _password_, they can be sent back to the
7696 * beginning to try another username, if this is configured on.
7697 * (If they specify a username in the config, they are never
7698 * asked, even if they do give a wrong password.)
7700 * I think this best serves the needs of
7702 * - the people who have no configuration, no keys, and just
7703 * want to try repeated (username,password) pairs until they
7704 * type both correctly
7706 * - people who have keys and configuration but occasionally
7707 * need to fall back to passwords
7709 * - people with a key held in Pageant, who might not have
7710 * logged in to a particular machine before; so they want to
7711 * type a username, and then _either_ their key will be
7712 * accepted, _or_ they will type a password. If they mistype
7713 * the username they will want to be able to get back and
7716 s
->got_username
= FALSE
;
7717 while (!s
->we_are_in
) {
7721 if (s
->got_username
&& !conf_get_int(ssh
->conf
, CONF_change_username
)) {
7723 * We got a username last time round this loop, and
7724 * with change_username turned off we don't try to get
7727 } else if ((ssh
->username
= get_remote_username(ssh
->conf
)) == NULL
) {
7728 int ret
; /* need not be kept over crReturn */
7729 s
->cur_prompt
= new_prompts(ssh
->frontend
);
7730 s
->cur_prompt
->to_server
= TRUE
;
7731 s
->cur_prompt
->name
= dupstr("SSH login name");
7732 add_prompt(s
->cur_prompt
, dupstr("login as: "), TRUE
);
7733 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
7736 crWaitUntilV(!pktin
);
7737 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
7742 * get_userpass_input() failed to get a username.
7745 free_prompts(s
->cur_prompt
);
7746 ssh_disconnect(ssh
, "No username provided", NULL
, 0, TRUE
);
7749 ssh
->username
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
7750 free_prompts(s
->cur_prompt
);
7753 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
7754 stuff
= dupprintf("Using username \"%s\".\r\n", ssh
->username
);
7755 c_write_str(ssh
, stuff
);
7759 s
->got_username
= TRUE
;
7762 * Send an authentication request using method "none": (a)
7763 * just in case it succeeds, and (b) so that we know what
7764 * authentication methods we can usefully try next.
7766 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
7768 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7769 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7770 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");/* service requested */
7771 ssh2_pkt_addstring(s
->pktout
, "none"); /* method */
7772 ssh2_pkt_send(ssh
, s
->pktout
);
7773 s
->type
= AUTH_TYPE_NONE
;
7775 s
->we_are_in
= FALSE
;
7777 s
->tried_pubkey_config
= FALSE
;
7778 s
->kbd_inter_refused
= FALSE
;
7780 /* Reset agent request state. */
7781 s
->done_agent
= FALSE
;
7782 if (s
->agent_response
) {
7783 if (s
->pkblob_in_agent
) {
7784 s
->agentp
= s
->pkblob_in_agent
;
7786 s
->agentp
= s
->agent_response
+ 5 + 4;
7792 char *methods
= NULL
;
7796 * Wait for the result of the last authentication request.
7799 crWaitUntilV(pktin
);
7801 * Now is a convenient point to spew any banner material
7802 * that we've accumulated. (This should ensure that when
7803 * we exit the auth loop, we haven't any left to deal
7807 int size
= bufchain_size(&ssh
->banner
);
7809 * Don't show the banner if we're operating in
7810 * non-verbose non-interactive mode. (It's probably
7811 * a script, which means nobody will read the
7812 * banner _anyway_, and moreover the printing of
7813 * the banner will screw up processing on the
7814 * output of (say) plink.)
7816 if (size
&& (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
))) {
7817 char *banner
= snewn(size
, char);
7818 bufchain_fetch(&ssh
->banner
, banner
, size
);
7819 c_write_untrusted(ssh
, banner
, size
);
7822 bufchain_clear(&ssh
->banner
);
7824 if (pktin
->type
== SSH2_MSG_USERAUTH_SUCCESS
) {
7825 logevent("Access granted");
7826 s
->we_are_in
= s
->userauth_success
= TRUE
;
7830 if (pktin
->type
!= SSH2_MSG_USERAUTH_FAILURE
&& s
->type
!= AUTH_TYPE_GSSAPI
) {
7831 bombout(("Strange packet received during authentication: "
7832 "type %d", pktin
->type
));
7839 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7840 * we can look at the string in it and know what we can
7841 * helpfully try next.
7843 if (pktin
->type
== SSH2_MSG_USERAUTH_FAILURE
) {
7844 ssh_pkt_getstring(pktin
, &methods
, &methlen
);
7845 if (!ssh2_pkt_getbool(pktin
)) {
7847 * We have received an unequivocal Access
7848 * Denied. This can translate to a variety of
7849 * messages, or no message at all.
7851 * For forms of authentication which are attempted
7852 * implicitly, by which I mean without printing
7853 * anything in the window indicating that we're
7854 * trying them, we should never print 'Access
7857 * If we do print a message saying that we're
7858 * attempting some kind of authentication, it's OK
7859 * to print a followup message saying it failed -
7860 * but the message may sometimes be more specific
7861 * than simply 'Access denied'.
7863 * Additionally, if we'd just tried password
7864 * authentication, we should break out of this
7865 * whole loop so as to go back to the username
7866 * prompt (iff we're configured to allow
7867 * username change attempts).
7869 if (s
->type
== AUTH_TYPE_NONE
) {
7871 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
7872 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
7873 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
7874 c_write_str(ssh
, "Server refused our key\r\n");
7875 logevent("Server refused our key");
7876 } else if (s
->type
== AUTH_TYPE_PUBLICKEY
) {
7877 /* This _shouldn't_ happen except by a
7878 * protocol bug causing client and server to
7879 * disagree on what is a correct signature. */
7880 c_write_str(ssh
, "Server refused public-key signature"
7881 " despite accepting key!\r\n");
7882 logevent("Server refused public-key signature"
7883 " despite accepting key!");
7884 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
7885 /* quiet, so no c_write */
7886 logevent("Server refused keyboard-interactive authentication");
7887 } else if (s
->type
==AUTH_TYPE_GSSAPI
) {
7888 /* always quiet, so no c_write */
7889 /* also, the code down in the GSSAPI block has
7890 * already logged this in the Event Log */
7891 } else if (s
->type
== AUTH_TYPE_KEYBOARD_INTERACTIVE
) {
7892 logevent("Keyboard-interactive authentication failed");
7893 c_write_str(ssh
, "Access denied\r\n");
7895 assert(s
->type
== AUTH_TYPE_PASSWORD
);
7896 logevent("Password authentication failed");
7897 c_write_str(ssh
, "Access denied\r\n");
7899 if (conf_get_int(ssh
->conf
, CONF_change_username
)) {
7900 /* XXX perhaps we should allow
7901 * keyboard-interactive to do this too? */
7902 s
->we_are_in
= FALSE
;
7907 c_write_str(ssh
, "Further authentication required\r\n");
7908 logevent("Further authentication required");
7912 in_commasep_string("publickey", methods
, methlen
);
7914 in_commasep_string("password", methods
, methlen
);
7915 s
->can_keyb_inter
= conf_get_int(ssh
->conf
, CONF_try_ki_auth
) &&
7916 in_commasep_string("keyboard-interactive", methods
, methlen
);
7919 ssh
->gsslibs
= ssh_gss_setup(ssh
->conf
);
7920 s
->can_gssapi
= conf_get_int(ssh
->conf
, CONF_try_gssapi_auth
) &&
7921 in_commasep_string("gssapi-with-mic", methods
, methlen
) &&
7922 ssh
->gsslibs
->nlibraries
> 0;
7926 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
7928 if (s
->can_pubkey
&& !s
->done_agent
&& s
->nkeys
) {
7931 * Attempt public-key authentication using a key from Pageant.
7934 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
7936 logeventf(ssh
, "Trying Pageant key #%d", s
->keyi
);
7938 /* Unpack key from agent response */
7939 s
->pklen
= GET_32BIT(s
->agentp
);
7941 s
->pkblob
= (char *)s
->agentp
;
7942 s
->agentp
+= s
->pklen
;
7943 s
->alglen
= GET_32BIT(s
->pkblob
);
7944 s
->alg
= s
->pkblob
+ 4;
7945 s
->commentlen
= GET_32BIT(s
->agentp
);
7947 s
->commentp
= (char *)s
->agentp
;
7948 s
->agentp
+= s
->commentlen
;
7949 /* s->agentp now points at next key, if any */
7951 /* See if server will accept it */
7952 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7953 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7954 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7955 /* service requested */
7956 ssh2_pkt_addstring(s
->pktout
, "publickey");
7958 ssh2_pkt_addbool(s
->pktout
, FALSE
); /* no signature included */
7959 ssh2_pkt_addstring_start(s
->pktout
);
7960 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
7961 ssh2_pkt_addstring_start(s
->pktout
);
7962 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
7963 ssh2_pkt_send(ssh
, s
->pktout
);
7964 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_QUIET
;
7966 crWaitUntilV(pktin
);
7967 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
7969 /* Offer of key refused. */
7976 if (flags
& FLAG_VERBOSE
) {
7977 c_write_str(ssh
, "Authenticating with "
7979 c_write(ssh
, s
->commentp
, s
->commentlen
);
7980 c_write_str(ssh
, "\" from agent\r\n");
7984 * Server is willing to accept the key.
7985 * Construct a SIGN_REQUEST.
7987 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
7988 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
7989 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
7990 /* service requested */
7991 ssh2_pkt_addstring(s
->pktout
, "publickey");
7993 ssh2_pkt_addbool(s
->pktout
, TRUE
); /* signature included */
7994 ssh2_pkt_addstring_start(s
->pktout
);
7995 ssh2_pkt_addstring_data(s
->pktout
, s
->alg
, s
->alglen
);
7996 ssh2_pkt_addstring_start(s
->pktout
);
7997 ssh2_pkt_addstring_data(s
->pktout
, s
->pkblob
, s
->pklen
);
7999 /* Ask agent for signature. */
8000 s
->siglen
= s
->pktout
->length
- 5 + 4 +
8001 ssh
->v2_session_id_len
;
8002 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8004 s
->len
= 1; /* message type */
8005 s
->len
+= 4 + s
->pklen
; /* key blob */
8006 s
->len
+= 4 + s
->siglen
; /* data to sign */
8007 s
->len
+= 4; /* flags */
8008 s
->agentreq
= snewn(4 + s
->len
, char);
8009 PUT_32BIT(s
->agentreq
, s
->len
);
8010 s
->q
= s
->agentreq
+ 4;
8011 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
8012 PUT_32BIT(s
->q
, s
->pklen
);
8014 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
8016 PUT_32BIT(s
->q
, s
->siglen
);
8018 /* Now the data to be signed... */
8019 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8020 PUT_32BIT(s
->q
, ssh
->v2_session_id_len
);
8023 memcpy(s
->q
, ssh
->v2_session_id
,
8024 ssh
->v2_session_id_len
);
8025 s
->q
+= ssh
->v2_session_id_len
;
8026 memcpy(s
->q
, s
->pktout
->data
+ 5,
8027 s
->pktout
->length
- 5);
8028 s
->q
+= s
->pktout
->length
- 5;
8029 /* And finally the (zero) flags word. */
8031 if (!agent_query(s
->agentreq
, s
->len
+ 4,
8033 ssh_agent_callback
, ssh
)) {
8037 bombout(("Unexpected data from server"
8038 " while waiting for agent"
8042 } while (pktin
|| inlen
> 0);
8043 vret
= ssh
->agent_response
;
8044 s
->retlen
= ssh
->agent_response_len
;
8049 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
8050 logevent("Sending Pageant's response");
8051 ssh2_add_sigblob(ssh
, s
->pktout
,
8052 s
->pkblob
, s
->pklen
,
8054 GET_32BIT(s
->ret
+ 5));
8055 ssh2_pkt_send(ssh
, s
->pktout
);
8056 s
->type
= AUTH_TYPE_PUBLICKEY
;
8058 /* FIXME: less drastic response */
8059 bombout(("Pageant failed to answer challenge"));
8065 /* Do we have any keys left to try? */
8066 if (s
->pkblob_in_agent
) {
8067 s
->done_agent
= TRUE
;
8068 s
->tried_pubkey_config
= TRUE
;
8071 if (s
->keyi
>= s
->nkeys
)
8072 s
->done_agent
= TRUE
;
8075 } else if (s
->can_pubkey
&& s
->publickey_blob
&&
8076 !s
->tried_pubkey_config
) {
8078 struct ssh2_userkey
*key
; /* not live over crReturn */
8079 char *passphrase
; /* not live over crReturn */
8081 ssh
->pkt_actx
= SSH2_PKTCTX_PUBLICKEY
;
8083 s
->tried_pubkey_config
= TRUE
;
8086 * Try the public key supplied in the configuration.
8088 * First, offer the public blob to see if the server is
8089 * willing to accept it.
8091 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8092 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8093 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8094 /* service requested */
8095 ssh2_pkt_addstring(s
->pktout
, "publickey"); /* method */
8096 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8097 /* no signature included */
8098 ssh2_pkt_addstring(s
->pktout
, s
->publickey_algorithm
);
8099 ssh2_pkt_addstring_start(s
->pktout
);
8100 ssh2_pkt_addstring_data(s
->pktout
,
8101 (char *)s
->publickey_blob
,
8102 s
->publickey_bloblen
);
8103 ssh2_pkt_send(ssh
, s
->pktout
);
8104 logevent("Offered public key");
8106 crWaitUntilV(pktin
);
8107 if (pktin
->type
!= SSH2_MSG_USERAUTH_PK_OK
) {
8108 /* Key refused. Give up. */
8109 s
->gotit
= TRUE
; /* reconsider message next loop */
8110 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
8111 continue; /* process this new message */
8113 logevent("Offer of public key accepted");
8116 * Actually attempt a serious authentication using
8119 if (flags
& FLAG_VERBOSE
) {
8120 c_write_str(ssh
, "Authenticating with public key \"");
8121 c_write_str(ssh
, s
->publickey_comment
);
8122 c_write_str(ssh
, "\"\r\n");
8126 const char *error
; /* not live over crReturn */
8127 if (s
->publickey_encrypted
) {
8129 * Get a passphrase from the user.
8131 int ret
; /* need not be kept over crReturn */
8132 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8133 s
->cur_prompt
->to_server
= FALSE
;
8134 s
->cur_prompt
->name
= dupstr("SSH key passphrase");
8135 add_prompt(s
->cur_prompt
,
8136 dupprintf("Passphrase for key \"%.100s\": ",
8137 s
->publickey_comment
),
8139 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8142 crWaitUntilV(!pktin
);
8143 ret
= get_userpass_input(s
->cur_prompt
,
8148 /* Failed to get a passphrase. Terminate. */
8149 free_prompts(s
->cur_prompt
);
8150 ssh_disconnect(ssh
, NULL
,
8151 "Unable to authenticate",
8152 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8157 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8158 free_prompts(s
->cur_prompt
);
8160 passphrase
= NULL
; /* no passphrase needed */
8164 * Try decrypting the key.
8166 s
->keyfile
= conf_get_filename(ssh
->conf
, CONF_keyfile
);
8167 key
= ssh2_load_userkey(s
->keyfile
, passphrase
, &error
);
8169 /* burn the evidence */
8170 smemclr(passphrase
, strlen(passphrase
));
8173 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
8175 (key
== SSH2_WRONG_PASSPHRASE
)) {
8176 c_write_str(ssh
, "Wrong passphrase\r\n");
8178 /* and loop again */
8180 c_write_str(ssh
, "Unable to load private key (");
8181 c_write_str(ssh
, error
);
8182 c_write_str(ssh
, ")\r\n");
8184 break; /* try something else */
8190 unsigned char *pkblob
, *sigblob
, *sigdata
;
8191 int pkblob_len
, sigblob_len
, sigdata_len
;
8195 * We have loaded the private key and the server
8196 * has announced that it's willing to accept it.
8197 * Hallelujah. Generate a signature and send it.
8199 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8200 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8201 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8202 /* service requested */
8203 ssh2_pkt_addstring(s
->pktout
, "publickey");
8205 ssh2_pkt_addbool(s
->pktout
, TRUE
);
8206 /* signature follows */
8207 ssh2_pkt_addstring(s
->pktout
, key
->alg
->name
);
8208 pkblob
= key
->alg
->public_blob(key
->data
,
8210 ssh2_pkt_addstring_start(s
->pktout
);
8211 ssh2_pkt_addstring_data(s
->pktout
, (char *)pkblob
,
8215 * The data to be signed is:
8219 * followed by everything so far placed in the
8222 sigdata_len
= s
->pktout
->length
- 5 + 4 +
8223 ssh
->v2_session_id_len
;
8224 if (ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)
8226 sigdata
= snewn(sigdata_len
, unsigned char);
8228 if (!(ssh
->remote_bugs
& BUG_SSH2_PK_SESSIONID
)) {
8229 PUT_32BIT(sigdata
+p
, ssh
->v2_session_id_len
);
8232 memcpy(sigdata
+p
, ssh
->v2_session_id
,
8233 ssh
->v2_session_id_len
);
8234 p
+= ssh
->v2_session_id_len
;
8235 memcpy(sigdata
+p
, s
->pktout
->data
+ 5,
8236 s
->pktout
->length
- 5);
8237 p
+= s
->pktout
->length
- 5;
8238 assert(p
== sigdata_len
);
8239 sigblob
= key
->alg
->sign(key
->data
, (char *)sigdata
,
8240 sigdata_len
, &sigblob_len
);
8241 ssh2_add_sigblob(ssh
, s
->pktout
, pkblob
, pkblob_len
,
8242 sigblob
, sigblob_len
);
8247 ssh2_pkt_send(ssh
, s
->pktout
);
8248 logevent("Sent public key signature");
8249 s
->type
= AUTH_TYPE_PUBLICKEY
;
8250 key
->alg
->freekey(key
->data
);
8254 } else if (s
->can_gssapi
&& !s
->tried_gssapi
) {
8256 /* GSSAPI Authentication */
8261 s
->type
= AUTH_TYPE_GSSAPI
;
8262 s
->tried_gssapi
= TRUE
;
8264 ssh
->pkt_actx
= SSH2_PKTCTX_GSSAPI
;
8267 * Pick the highest GSS library on the preference
8273 for (i
= 0; i
< ngsslibs
; i
++) {
8274 int want_id
= conf_get_int_int(ssh
->conf
,
8275 CONF_ssh_gsslist
, i
);
8276 for (j
= 0; j
< ssh
->gsslibs
->nlibraries
; j
++)
8277 if (ssh
->gsslibs
->libraries
[j
].id
== want_id
) {
8278 s
->gsslib
= &ssh
->gsslibs
->libraries
[j
];
8279 goto got_gsslib
; /* double break */
8284 * We always expect to have found something in
8285 * the above loop: we only came here if there
8286 * was at least one viable GSS library, and the
8287 * preference list should always mention
8288 * everything and only change the order.
8293 if (s
->gsslib
->gsslogmsg
)
8294 logevent(s
->gsslib
->gsslogmsg
);
8296 /* Sending USERAUTH_REQUEST with "gssapi-with-mic" method */
8297 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8298 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8299 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8300 ssh2_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8301 logevent("Attempting GSSAPI authentication");
8303 /* add mechanism info */
8304 s
->gsslib
->indicate_mech(s
->gsslib
, &s
->gss_buf
);
8306 /* number of GSSAPI mechanisms */
8307 ssh2_pkt_adduint32(s
->pktout
,1);
8309 /* length of OID + 2 */
8310 ssh2_pkt_adduint32(s
->pktout
, s
->gss_buf
.length
+ 2);
8311 ssh2_pkt_addbyte(s
->pktout
, SSH2_GSS_OIDTYPE
);
8314 ssh2_pkt_addbyte(s
->pktout
, (unsigned char) s
->gss_buf
.length
);
8316 ssh_pkt_adddata(s
->pktout
, s
->gss_buf
.value
,
8318 ssh2_pkt_send(ssh
, s
->pktout
);
8319 crWaitUntilV(pktin
);
8320 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_RESPONSE
) {
8321 logevent("GSSAPI authentication request refused");
8325 /* check returned packet ... */
8327 ssh_pkt_getstring(pktin
, &data
, &len
);
8328 s
->gss_rcvtok
.value
= data
;
8329 s
->gss_rcvtok
.length
= len
;
8330 if (s
->gss_rcvtok
.length
!= s
->gss_buf
.length
+ 2 ||
8331 ((char *)s
->gss_rcvtok
.value
)[0] != SSH2_GSS_OIDTYPE
||
8332 ((char *)s
->gss_rcvtok
.value
)[1] != s
->gss_buf
.length
||
8333 memcmp((char *)s
->gss_rcvtok
.value
+ 2,
8334 s
->gss_buf
.value
,s
->gss_buf
.length
) ) {
8335 logevent("GSSAPI authentication - wrong response from server");
8339 /* now start running */
8340 s
->gss_stat
= s
->gsslib
->import_name(s
->gsslib
,
8343 if (s
->gss_stat
!= SSH_GSS_OK
) {
8344 if (s
->gss_stat
== SSH_GSS_BAD_HOST_NAME
)
8345 logevent("GSSAPI import name failed - Bad service name");
8347 logevent("GSSAPI import name failed");
8351 /* fetch TGT into GSS engine */
8352 s
->gss_stat
= s
->gsslib
->acquire_cred(s
->gsslib
, &s
->gss_ctx
);
8354 if (s
->gss_stat
!= SSH_GSS_OK
) {
8355 logevent("GSSAPI authentication failed to get credentials");
8356 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8360 /* initial tokens are empty */
8361 SSH_GSS_CLEAR_BUF(&s
->gss_rcvtok
);
8362 SSH_GSS_CLEAR_BUF(&s
->gss_sndtok
);
8364 /* now enter the loop */
8366 s
->gss_stat
= s
->gsslib
->init_sec_context
8370 conf_get_int(ssh
->conf
, CONF_gssapifwd
),
8374 if (s
->gss_stat
!=SSH_GSS_S_COMPLETE
&&
8375 s
->gss_stat
!=SSH_GSS_S_CONTINUE_NEEDED
) {
8376 logevent("GSSAPI authentication initialisation failed");
8378 if (s
->gsslib
->display_status(s
->gsslib
, s
->gss_ctx
,
8379 &s
->gss_buf
) == SSH_GSS_OK
) {
8380 logevent(s
->gss_buf
.value
);
8381 sfree(s
->gss_buf
.value
);
8386 logevent("GSSAPI authentication initialised");
8388 /* Client and server now exchange tokens until GSSAPI
8389 * no longer says CONTINUE_NEEDED */
8391 if (s
->gss_sndtok
.length
!= 0) {
8392 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_TOKEN
);
8393 ssh_pkt_addstring_start(s
->pktout
);
8394 ssh_pkt_addstring_data(s
->pktout
,s
->gss_sndtok
.value
,s
->gss_sndtok
.length
);
8395 ssh2_pkt_send(ssh
, s
->pktout
);
8396 s
->gsslib
->free_tok(s
->gsslib
, &s
->gss_sndtok
);
8399 if (s
->gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
) {
8400 crWaitUntilV(pktin
);
8401 if (pktin
->type
!= SSH2_MSG_USERAUTH_GSSAPI_TOKEN
) {
8402 logevent("GSSAPI authentication - bad server response");
8403 s
->gss_stat
= SSH_GSS_FAILURE
;
8406 ssh_pkt_getstring(pktin
, &data
, &len
);
8407 s
->gss_rcvtok
.value
= data
;
8408 s
->gss_rcvtok
.length
= len
;
8410 } while (s
-> gss_stat
== SSH_GSS_S_CONTINUE_NEEDED
);
8412 if (s
->gss_stat
!= SSH_GSS_OK
) {
8413 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8414 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8417 logevent("GSSAPI authentication loop finished OK");
8419 /* Now send the MIC */
8421 s
->pktout
= ssh2_pkt_init(0);
8422 micoffset
= s
->pktout
->length
;
8423 ssh_pkt_addstring_start(s
->pktout
);
8424 ssh_pkt_addstring_data(s
->pktout
, (char *)ssh
->v2_session_id
, ssh
->v2_session_id_len
);
8425 ssh_pkt_addbyte(s
->pktout
, SSH2_MSG_USERAUTH_REQUEST
);
8426 ssh_pkt_addstring(s
->pktout
, ssh
->username
);
8427 ssh_pkt_addstring(s
->pktout
, "ssh-connection");
8428 ssh_pkt_addstring(s
->pktout
, "gssapi-with-mic");
8430 s
->gss_buf
.value
= (char *)s
->pktout
->data
+ micoffset
;
8431 s
->gss_buf
.length
= s
->pktout
->length
- micoffset
;
8433 s
->gsslib
->get_mic(s
->gsslib
, s
->gss_ctx
, &s
->gss_buf
, &mic
);
8434 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_GSSAPI_MIC
);
8435 ssh_pkt_addstring_start(s
->pktout
);
8436 ssh_pkt_addstring_data(s
->pktout
, mic
.value
, mic
.length
);
8437 ssh2_pkt_send(ssh
, s
->pktout
);
8438 s
->gsslib
->free_mic(s
->gsslib
, &mic
);
8442 s
->gsslib
->release_name(s
->gsslib
, &s
->gss_srv_name
);
8443 s
->gsslib
->release_cred(s
->gsslib
, &s
->gss_ctx
);
8446 } else if (s
->can_keyb_inter
&& !s
->kbd_inter_refused
) {
8449 * Keyboard-interactive authentication.
8452 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
8454 ssh
->pkt_actx
= SSH2_PKTCTX_KBDINTER
;
8456 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8457 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8458 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8459 /* service requested */
8460 ssh2_pkt_addstring(s
->pktout
, "keyboard-interactive");
8462 ssh2_pkt_addstring(s
->pktout
, ""); /* lang */
8463 ssh2_pkt_addstring(s
->pktout
, ""); /* submethods */
8464 ssh2_pkt_send(ssh
, s
->pktout
);
8466 logevent("Attempting keyboard-interactive authentication");
8468 crWaitUntilV(pktin
);
8469 if (pktin
->type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8470 /* Server is not willing to do keyboard-interactive
8471 * at all (or, bizarrely but legally, accepts the
8472 * user without actually issuing any prompts).
8473 * Give up on it entirely. */
8475 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
8476 s
->kbd_inter_refused
= TRUE
; /* don't try it again */
8481 * Loop while the server continues to send INFO_REQUESTs.
8483 while (pktin
->type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
8485 char *name
, *inst
, *lang
;
8486 int name_len
, inst_len
, lang_len
;
8490 * We've got a fresh USERAUTH_INFO_REQUEST.
8491 * Get the preamble and start building a prompt.
8493 ssh_pkt_getstring(pktin
, &name
, &name_len
);
8494 ssh_pkt_getstring(pktin
, &inst
, &inst_len
);
8495 ssh_pkt_getstring(pktin
, &lang
, &lang_len
);
8496 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8497 s
->cur_prompt
->to_server
= TRUE
;
8500 * Get any prompt(s) from the packet.
8502 s
->num_prompts
= ssh_pkt_getuint32(pktin
);
8503 for (i
= 0; i
< s
->num_prompts
; i
++) {
8507 static char noprompt
[] =
8508 "<server failed to send prompt>: ";
8510 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8511 echo
= ssh2_pkt_getbool(pktin
);
8514 prompt_len
= lenof(noprompt
)-1;
8516 add_prompt(s
->cur_prompt
,
8517 dupprintf("%.*s", prompt_len
, prompt
),
8522 /* FIXME: better prefix to distinguish from
8524 s
->cur_prompt
->name
=
8525 dupprintf("SSH server: %.*s", name_len
, name
);
8526 s
->cur_prompt
->name_reqd
= TRUE
;
8528 s
->cur_prompt
->name
=
8529 dupstr("SSH server authentication");
8530 s
->cur_prompt
->name_reqd
= FALSE
;
8532 /* We add a prefix to try to make it clear that a prompt
8533 * has come from the server.
8534 * FIXME: ugly to print "Using..." in prompt _every_
8535 * time round. Can this be done more subtly? */
8536 /* Special case: for reasons best known to themselves,
8537 * some servers send k-i requests with no prompts and
8538 * nothing to display. Keep quiet in this case. */
8539 if (s
->num_prompts
|| name_len
|| inst_len
) {
8540 s
->cur_prompt
->instruction
=
8541 dupprintf("Using keyboard-interactive authentication.%s%.*s",
8542 inst_len ?
"\n" : "", inst_len
, inst
);
8543 s
->cur_prompt
->instr_reqd
= TRUE
;
8545 s
->cur_prompt
->instr_reqd
= FALSE
;
8549 * Display any instructions, and get the user's
8553 int ret
; /* not live over crReturn */
8554 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8557 crWaitUntilV(!pktin
);
8558 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8563 * Failed to get responses. Terminate.
8565 free_prompts(s
->cur_prompt
);
8566 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8567 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8574 * Send the response(s) to the server.
8576 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
8577 ssh2_pkt_adduint32(s
->pktout
, s
->num_prompts
);
8578 for (i
=0; i
< s
->num_prompts
; i
++) {
8579 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8580 ssh2_pkt_addstring(s
->pktout
,
8581 s
->cur_prompt
->prompts
[i
]->result
);
8582 end_log_omission(ssh
, s
->pktout
);
8584 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8587 * Free the prompts structure from this iteration.
8588 * If there's another, a new one will be allocated
8589 * when we return to the top of this while loop.
8591 free_prompts(s
->cur_prompt
);
8594 * Get the next packet in case it's another
8597 crWaitUntilV(pktin
);
8602 * We should have SUCCESS or FAILURE now.
8606 } else if (s
->can_passwd
) {
8609 * Plain old password authentication.
8611 int ret
; /* not live over crReturn */
8612 int changereq_first_time
; /* not live over crReturn */
8614 ssh
->pkt_actx
= SSH2_PKTCTX_PASSWORD
;
8616 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8617 s
->cur_prompt
->to_server
= TRUE
;
8618 s
->cur_prompt
->name
= dupstr("SSH password");
8619 add_prompt(s
->cur_prompt
, dupprintf("%s@%s's password: ",
8624 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8627 crWaitUntilV(!pktin
);
8628 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8633 * Failed to get responses. Terminate.
8635 free_prompts(s
->cur_prompt
);
8636 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8637 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8642 * Squirrel away the password. (We may need it later if
8643 * asked to change it.)
8645 s
->password
= dupstr(s
->cur_prompt
->prompts
[0]->result
);
8646 free_prompts(s
->cur_prompt
);
8649 * Send the password packet.
8651 * We pad out the password packet to 256 bytes to make
8652 * it harder for an attacker to find the length of the
8655 * Anyone using a password longer than 256 bytes
8656 * probably doesn't have much to worry about from
8657 * people who find out how long their password is!
8659 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8660 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8661 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8662 /* service requested */
8663 ssh2_pkt_addstring(s
->pktout
, "password");
8664 ssh2_pkt_addbool(s
->pktout
, FALSE
);
8665 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8666 ssh2_pkt_addstring(s
->pktout
, s
->password
);
8667 end_log_omission(ssh
, s
->pktout
);
8668 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8669 logevent("Sent password");
8670 s
->type
= AUTH_TYPE_PASSWORD
;
8673 * Wait for next packet, in case it's a password change
8676 crWaitUntilV(pktin
);
8677 changereq_first_time
= TRUE
;
8679 while (pktin
->type
== SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
) {
8682 * We're being asked for a new password
8683 * (perhaps not for the first time).
8684 * Loop until the server accepts it.
8687 int got_new
= FALSE
; /* not live over crReturn */
8688 char *prompt
; /* not live over crReturn */
8689 int prompt_len
; /* not live over crReturn */
8693 if (changereq_first_time
)
8694 msg
= "Server requested password change";
8696 msg
= "Server rejected new password";
8698 c_write_str(ssh
, msg
);
8699 c_write_str(ssh
, "\r\n");
8702 ssh_pkt_getstring(pktin
, &prompt
, &prompt_len
);
8704 s
->cur_prompt
= new_prompts(ssh
->frontend
);
8705 s
->cur_prompt
->to_server
= TRUE
;
8706 s
->cur_prompt
->name
= dupstr("New SSH password");
8707 s
->cur_prompt
->instruction
=
8708 dupprintf("%.*s", prompt_len
, prompt
);
8709 s
->cur_prompt
->instr_reqd
= TRUE
;
8711 * There's no explicit requirement in the protocol
8712 * for the "old" passwords in the original and
8713 * password-change messages to be the same, and
8714 * apparently some Cisco kit supports password change
8715 * by the user entering a blank password originally
8716 * and the real password subsequently, so,
8717 * reluctantly, we prompt for the old password again.
8719 * (On the other hand, some servers don't even bother
8720 * to check this field.)
8722 add_prompt(s
->cur_prompt
,
8723 dupstr("Current password (blank for previously entered password): "),
8725 add_prompt(s
->cur_prompt
, dupstr("Enter new password: "),
8727 add_prompt(s
->cur_prompt
, dupstr("Confirm new password: "),
8731 * Loop until the user manages to enter the same
8736 ret
= get_userpass_input(s
->cur_prompt
, NULL
, 0);
8739 crWaitUntilV(!pktin
);
8740 ret
= get_userpass_input(s
->cur_prompt
, in
, inlen
);
8745 * Failed to get responses. Terminate.
8747 /* burn the evidence */
8748 free_prompts(s
->cur_prompt
);
8749 smemclr(s
->password
, strlen(s
->password
));
8751 ssh_disconnect(ssh
, NULL
, "Unable to authenticate",
8752 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER
,
8758 * If the user specified a new original password
8759 * (IYSWIM), overwrite any previously specified
8761 * (A side effect is that the user doesn't have to
8762 * re-enter it if they louse up the new password.)
8764 if (s
->cur_prompt
->prompts
[0]->result
[0]) {
8765 smemclr(s
->password
, strlen(s
->password
));
8766 /* burn the evidence */
8769 dupstr(s
->cur_prompt
->prompts
[0]->result
);
8773 * Check the two new passwords match.
8775 got_new
= (strcmp(s
->cur_prompt
->prompts
[1]->result
,
8776 s
->cur_prompt
->prompts
[2]->result
)
8779 /* They don't. Silly user. */
8780 c_write_str(ssh
, "Passwords do not match\r\n");
8785 * Send the new password (along with the old one).
8786 * (see above for padding rationale)
8788 s
->pktout
= ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
8789 ssh2_pkt_addstring(s
->pktout
, ssh
->username
);
8790 ssh2_pkt_addstring(s
->pktout
, "ssh-connection");
8791 /* service requested */
8792 ssh2_pkt_addstring(s
->pktout
, "password");
8793 ssh2_pkt_addbool(s
->pktout
, TRUE
);
8794 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
8795 ssh2_pkt_addstring(s
->pktout
, s
->password
);
8796 ssh2_pkt_addstring(s
->pktout
,
8797 s
->cur_prompt
->prompts
[1]->result
);
8798 free_prompts(s
->cur_prompt
);
8799 end_log_omission(ssh
, s
->pktout
);
8800 ssh2_pkt_send_with_padding(ssh
, s
->pktout
, 256);
8801 logevent("Sent new password");
8804 * Now see what the server has to say about it.
8805 * (If it's CHANGEREQ again, it's not happy with the
8808 crWaitUntilV(pktin
);
8809 changereq_first_time
= FALSE
;
8814 * We need to reexamine the current pktin at the top
8815 * of the loop. Either:
8816 * - we weren't asked to change password at all, in
8817 * which case it's a SUCCESS or FAILURE with the
8819 * - we sent a new password, and the server was
8820 * either OK with it (SUCCESS or FAILURE w/partial
8821 * success) or unhappy with the _old_ password
8822 * (FAILURE w/o partial success)
8823 * In any of these cases, we go back to the top of
8824 * the loop and start again.
8829 * We don't need the old password any more, in any
8830 * case. Burn the evidence.
8832 smemclr(s
->password
, strlen(s
->password
));
8836 char *str
= dupprintf("No supported authentication methods available"
8837 " (server sent: %.*s)",
8840 ssh_disconnect(ssh
, str
,
8841 "No supported authentication methods available",
8842 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE
,
8852 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = NULL
;
8854 /* Clear up various bits and pieces from authentication. */
8855 if (s
->publickey_blob
) {
8856 sfree(s
->publickey_blob
);
8857 sfree(s
->publickey_comment
);
8859 if (s
->agent_response
)
8860 sfree(s
->agent_response
);
8862 if (s
->userauth_success
) {
8864 * We've just received USERAUTH_SUCCESS, and we haven't sent any
8865 * packets since. Signal the transport layer to consider enacting
8866 * delayed compression.
8868 * (Relying on we_are_in is not sufficient, as
8869 * draft-miller-secsh-compression-delayed is quite clear that it
8870 * triggers on USERAUTH_SUCCESS specifically, and we_are_in can
8871 * become set for other reasons.)
8873 do_ssh2_transport(ssh
, "enabling delayed compression", -2, NULL
);
8877 * Now the connection protocol has started, one way or another.
8880 ssh
->channels
= newtree234(ssh_channelcmp
);
8883 * Set up handlers for some connection protocol messages, so we
8884 * don't have to handle them repeatedly in this coroutine.
8886 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] =
8887 ssh2_msg_channel_window_adjust
;
8888 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] =
8889 ssh2_msg_global_request
;
8892 * Create the main session channel.
8894 if (conf_get_int(ssh
->conf
, CONF_ssh_no_shell
)) {
8895 ssh
->mainchan
= NULL
;
8896 } else if (*conf_get_str(ssh
->conf
, CONF_ssh_nc_host
)) {
8898 * Just start a direct-tcpip channel and use it as the main
8901 ssh
->mainchan
= snew(struct ssh_channel
);
8902 ssh
->mainchan
->ssh
= ssh
;
8903 ssh2_channel_init(ssh
->mainchan
);
8905 "Opening direct-tcpip channel to %s:%d in place of session",
8906 conf_get_str(ssh
->conf
, CONF_ssh_nc_host
),
8907 conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
8908 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
8909 ssh2_pkt_addstring(s
->pktout
, "direct-tcpip");
8910 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
8911 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
8912 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
8913 ssh2_pkt_addstring(s
->pktout
, conf_get_str(ssh
->conf
, CONF_ssh_nc_host
));
8914 ssh2_pkt_adduint32(s
->pktout
, conf_get_int(ssh
->conf
, CONF_ssh_nc_port
));
8916 * There's nothing meaningful to put in the originator
8917 * fields, but some servers insist on syntactically correct
8920 ssh2_pkt_addstring(s
->pktout
, "0.0.0.0");
8921 ssh2_pkt_adduint32(s
->pktout
, 0);
8922 ssh2_pkt_send(ssh
, s
->pktout
);
8924 crWaitUntilV(pktin
);
8925 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
8926 bombout(("Server refused to open a direct-tcpip channel"));
8928 /* FIXME: error data comes back in FAILURE packet */
8930 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
8931 bombout(("Server's channel confirmation cited wrong channel"));
8934 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
8935 ssh
->mainchan
->halfopen
= FALSE
;
8936 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
8937 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
8938 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
8939 add234(ssh
->channels
, ssh
->mainchan
);
8940 update_specials_menu(ssh
->frontend
);
8941 logevent("Opened direct-tcpip channel");
8944 ssh
->mainchan
= snew(struct ssh_channel
);
8945 ssh
->mainchan
->ssh
= ssh
;
8946 ssh2_channel_init(ssh
->mainchan
);
8947 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
8948 ssh2_pkt_addstring(s
->pktout
, "session");
8949 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->localid
);
8950 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
8951 ssh2_pkt_adduint32(s
->pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
8952 ssh2_pkt_send(ssh
, s
->pktout
);
8953 crWaitUntilV(pktin
);
8954 if (pktin
->type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
8955 bombout(("Server refused to open a session"));
8957 /* FIXME: error data comes back in FAILURE packet */
8959 if (ssh_pkt_getuint32(pktin
) != ssh
->mainchan
->localid
) {
8960 bombout(("Server's channel confirmation cited wrong channel"));
8963 ssh
->mainchan
->remoteid
= ssh_pkt_getuint32(pktin
);
8964 ssh
->mainchan
->halfopen
= FALSE
;
8965 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
8966 ssh
->mainchan
->v
.v2
.remwindow
= ssh_pkt_getuint32(pktin
);
8967 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh_pkt_getuint32(pktin
);
8968 add234(ssh
->channels
, ssh
->mainchan
);
8969 update_specials_menu(ssh
->frontend
);
8970 logevent("Opened channel for session");
8971 ssh
->ncmode
= FALSE
;
8975 * Now we have a channel, make dispatch table entries for
8976 * general channel-based messages.
8978 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] =
8979 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] =
8980 ssh2_msg_channel_data
;
8981 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = ssh2_msg_channel_eof
;
8982 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = ssh2_msg_channel_close
;
8983 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] =
8984 ssh2_msg_channel_open_confirmation
;
8985 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] =
8986 ssh2_msg_channel_open_failure
;
8987 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] =
8988 ssh2_msg_channel_request
;
8989 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] =
8990 ssh2_msg_channel_open
;
8992 if (ssh
->mainchan
&& conf_get_int(ssh
->conf
, CONF_ssh_simple
)) {
8994 * This message indicates to the server that we promise
8995 * not to try to run any other channel in parallel with
8996 * this one, so it's safe for it to advertise a very large
8997 * window and leave the flow control to TCP.
8999 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9000 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
);
9001 ssh2_pkt_addstring(s
->pktout
, "simple@putty.projects.tartarus.org");
9002 ssh2_pkt_addbool(s
->pktout
, 0); /* no reply */
9003 ssh2_pkt_send(ssh
, s
->pktout
);
9007 * Enable port forwardings.
9009 ssh_setup_portfwd(ssh
, ssh
->conf
);
9012 * Send the CHANNEL_REQUESTS for the main channel. We send them all
9013 * and then start looking for responses, so it's important that the
9014 * sending and receiving code below it is kept in sync.
9018 * Potentially enable X11 forwarding.
9020 if (ssh
->mainchan
&& !ssh
->ncmode
&& conf_get_int(ssh
->conf
, CONF_x11_forward
) &&
9021 (ssh
->x11disp
= x11_setup_display(conf_get_str(ssh
->conf
, CONF_x11_display
),
9022 conf_get_int(ssh
->conf
, CONF_x11_auth
), ssh
->conf
))) {
9023 logevent("Requesting X11 forwarding");
9024 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9025 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
);
9026 ssh2_pkt_addstring(s
->pktout
, "x11-req");
9027 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9028 ssh2_pkt_addbool(s
->pktout
, 0); /* many connections */
9029 ssh2_pkt_addstring(s
->pktout
, ssh
->x11disp
->remoteauthprotoname
);
9031 * Note that while we blank the X authentication data here, we don't
9032 * take any special action to blank the start of an X11 channel,
9033 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
9034 * without having session blanking enabled is likely to leak your
9035 * cookie into the log.
9037 dont_log_password(ssh
, s
->pktout
, PKTLOG_BLANK
);
9038 ssh2_pkt_addstring(s
->pktout
, ssh
->x11disp
->remoteauthdatastring
);
9039 end_log_omission(ssh
, s
->pktout
);
9040 ssh2_pkt_adduint32(s
->pktout
, ssh
->x11disp
->screennum
);
9041 ssh2_pkt_send(ssh
, s
->pktout
);
9042 s
->requested_x11
= TRUE
;
9044 s
->requested_x11
= FALSE
;
9047 * Potentially enable agent forwarding.
9049 if (ssh
->mainchan
&& !ssh
->ncmode
&& conf_get_int(ssh
->conf
, CONF_agentfwd
) && agent_exists()) {
9050 logevent("Requesting OpenSSH-style agent forwarding");
9051 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9052 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
);
9053 ssh2_pkt_addstring(s
->pktout
, "auth-agent-req@openssh.com");
9054 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9055 ssh2_pkt_send(ssh
, s
->pktout
);
9056 s
->requested_agent
= TRUE
;
9058 s
->requested_agent
= FALSE
;
9061 * Now allocate a pty for the session.
9063 if (ssh
->mainchan
&& !ssh
->ncmode
&& !conf_get_int(ssh
->conf
, CONF_nopty
)) {
9064 /* Unpick the terminal-speed string. */
9065 /* XXX perhaps we should allow no speeds to be sent. */
9066 ssh
->ospeed
= 38400; ssh
->ispeed
= 38400; /* last-resort defaults */
9067 sscanf(conf_get_str(ssh
->conf
, CONF_termspeed
), "%d,%d", &ssh
->ospeed
, &ssh
->ispeed
);
9068 /* Build the pty request. */
9069 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9070 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
); /* recipient channel */
9071 ssh2_pkt_addstring(s
->pktout
, "pty-req");
9072 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9073 ssh2_pkt_addstring(s
->pktout
, conf_get_str(ssh
->conf
, CONF_termtype
));
9074 ssh2_pkt_adduint32(s
->pktout
, ssh
->term_width
);
9075 ssh2_pkt_adduint32(s
->pktout
, ssh
->term_height
);
9076 ssh2_pkt_adduint32(s
->pktout
, 0); /* pixel width */
9077 ssh2_pkt_adduint32(s
->pktout
, 0); /* pixel height */
9078 ssh2_pkt_addstring_start(s
->pktout
);
9079 parse_ttymodes(ssh
, ssh2_send_ttymode
, (void *)s
->pktout
);
9080 ssh2_pkt_addbyte(s
->pktout
, SSH2_TTY_OP_ISPEED
);
9081 ssh2_pkt_adduint32(s
->pktout
, ssh
->ispeed
);
9082 ssh2_pkt_addbyte(s
->pktout
, SSH2_TTY_OP_OSPEED
);
9083 ssh2_pkt_adduint32(s
->pktout
, ssh
->ospeed
);
9084 ssh2_pkt_addstring_data(s
->pktout
, "\0", 1); /* TTY_OP_END */
9085 ssh2_pkt_send(ssh
, s
->pktout
);
9086 ssh
->state
= SSH_STATE_INTERMED
;
9087 s
->requested_tty
= TRUE
;
9089 s
->requested_tty
= FALSE
;
9092 * Send environment variables.
9094 * Simplest thing here is to send all the requests at once, and
9095 * then wait for a whole bunch of successes or failures.
9098 if (ssh
->mainchan
&& !ssh
->ncmode
) {
9101 for (val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, NULL
, &key
);
9103 val
= conf_get_str_strs(ssh
->conf
, CONF_environmt
, key
, &key
)) {
9104 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9105 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
);
9106 ssh2_pkt_addstring(s
->pktout
, "env");
9107 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9108 ssh2_pkt_addstring(s
->pktout
, key
);
9109 ssh2_pkt_addstring(s
->pktout
, val
);
9110 ssh2_pkt_send(ssh
, s
->pktout
);
9115 logeventf(ssh
, "Sent %d environment variables", s
->num_env
);
9119 * All CHANNEL_REQUESTs sent. Now collect up the replies. These
9120 * must be in precisely the same order as the requests.
9123 if (s
->requested_x11
) {
9124 crWaitUntilV(pktin
);
9126 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9127 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9128 bombout(("Unexpected response to X11 forwarding request:"
9129 " packet type %d", pktin
->type
));
9132 logevent("X11 forwarding refused");
9134 logevent("X11 forwarding enabled");
9135 ssh
->X11_fwd_enabled
= TRUE
;
9139 if (s
->requested_agent
) {
9140 crWaitUntilV(pktin
);
9142 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9143 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9144 bombout(("Unexpected response to agent forwarding request:"
9145 " packet type %d", pktin
->type
));
9148 logevent("Agent forwarding refused");
9150 logevent("Agent forwarding enabled");
9151 ssh
->agentfwd_enabled
= TRUE
;
9155 if (s
->requested_tty
) {
9156 crWaitUntilV(pktin
);
9158 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9159 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9160 bombout(("Unexpected response to pty request:"
9161 " packet type %d", pktin
->type
));
9164 c_write_str(ssh
, "Server refused to allocate pty\r\n");
9165 ssh
->editing
= ssh
->echoing
= 1;
9167 logeventf(ssh
, "Allocated pty (ospeed %dbps, ispeed %dbps)",
9168 ssh
->ospeed
, ssh
->ispeed
);
9169 ssh
->got_pty
= TRUE
;
9172 ssh
->editing
= ssh
->echoing
= 1;
9177 s
->env_left
= s
->num_env
;
9179 while (s
->env_left
> 0) {
9180 crWaitUntilV(pktin
);
9182 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9183 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9184 bombout(("Unexpected response to environment request:"
9185 " packet type %d", pktin
->type
));
9195 if (s
->env_ok
== s
->num_env
) {
9196 logevent("All environment variables successfully set");
9197 } else if (s
->env_ok
== 0) {
9198 logevent("All environment variables refused");
9199 c_write_str(ssh
, "Server refused to set environment variables\r\n");
9201 logeventf(ssh
, "%d environment variables refused",
9202 s
->num_env
- s
->env_ok
);
9203 c_write_str(ssh
, "Server refused to set all environment variables\r\n");
9208 * Start a shell or a remote command. We may have to attempt
9209 * this twice if the config data has provided a second choice
9212 if (ssh
->mainchan
&& !ssh
->ncmode
) while (1) {
9216 if (ssh
->fallback_cmd
) {
9217 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys2
);
9218 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd2
);
9220 subsys
= conf_get_int(ssh
->conf
, CONF_ssh_subsys
);
9221 cmd
= conf_get_str(ssh
->conf
, CONF_remote_cmd
);
9224 s
->pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9225 ssh2_pkt_adduint32(s
->pktout
, ssh
->mainchan
->remoteid
); /* recipient channel */
9227 ssh2_pkt_addstring(s
->pktout
, "subsystem");
9228 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9229 ssh2_pkt_addstring(s
->pktout
, cmd
);
9231 ssh2_pkt_addstring(s
->pktout
, "exec");
9232 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9233 ssh2_pkt_addstring(s
->pktout
, cmd
);
9235 ssh2_pkt_addstring(s
->pktout
, "shell");
9236 ssh2_pkt_addbool(s
->pktout
, 1); /* want reply */
9238 ssh2_pkt_send(ssh
, s
->pktout
);
9240 crWaitUntilV(pktin
);
9242 if (pktin
->type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
9243 if (pktin
->type
!= SSH2_MSG_CHANNEL_FAILURE
) {
9244 bombout(("Unexpected response to shell/command request:"
9245 " packet type %d", pktin
->type
));
9249 * We failed to start the command. If this is the
9250 * fallback command, we really are finished; if it's
9251 * not, and if the fallback command exists, try falling
9252 * back to it before complaining.
9254 if (!ssh
->fallback_cmd
&&
9255 *conf_get_str(ssh
->conf
, CONF_remote_cmd2
)) {
9256 logevent("Primary command failed; attempting fallback");
9257 ssh
->fallback_cmd
= TRUE
;
9260 bombout(("Server refused to start a shell/command"));
9263 logevent("Started a shell/command");
9268 ssh
->state
= SSH_STATE_SESSION
;
9269 if (ssh
->size_needed
)
9270 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
9271 if (ssh
->eof_needed
)
9272 ssh_special(ssh
, TS_EOF
);
9275 * All the initial channel requests are done, so install the default
9278 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = ssh2_msg_channel_success
;
9279 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = ssh2_msg_channel_failure
;
9285 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
9290 s
->try_send
= FALSE
;
9294 * _All_ the connection-layer packets we expect to
9295 * receive are now handled by the dispatch table.
9296 * Anything that reaches here must be bogus.
9299 bombout(("Strange packet received: type %d", pktin
->type
));
9301 } else if (ssh
->mainchan
) {
9303 * We have spare data. Add it to the channel buffer.
9305 ssh2_add_channel_data(ssh
->mainchan
, (char *)in
, inlen
);
9310 struct ssh_channel
*c
;
9312 * Try to send data on all channels if we can.
9314 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++)
9315 ssh2_try_send_and_unthrottle(ssh
, c
);
9323 * Handlers for SSH-2 messages that might arrive at any moment.
9325 static void ssh2_msg_disconnect(Ssh ssh
, struct Packet
*pktin
)
9327 /* log reason code in disconnect message */
9331 reason
= ssh_pkt_getuint32(pktin
);
9332 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9334 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
9335 buf
= dupprintf("Received disconnect message (%s)",
9336 ssh2_disconnect_reasons
[reason
]);
9338 buf
= dupprintf("Received disconnect message (unknown"
9339 " type %d)", reason
);
9343 buf
= dupprintf("Disconnection message text: %.*s",
9346 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"",
9348 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
9349 ssh2_disconnect_reasons
[reason
] : "unknown",
9354 static void ssh2_msg_debug(Ssh ssh
, struct Packet
*pktin
)
9356 /* log the debug message */
9360 /* XXX maybe we should actually take notice of the return value */
9361 ssh2_pkt_getbool(pktin
);
9362 ssh_pkt_getstring(pktin
, &msg
, &msglen
);
9364 logeventf(ssh
, "Remote debug message: %.*s", msglen
, msg
);
9367 static void ssh2_msg_something_unimplemented(Ssh ssh
, struct Packet
*pktin
)
9369 struct Packet
*pktout
;
9370 pktout
= ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
9371 ssh2_pkt_adduint32(pktout
, pktin
->sequence
);
9373 * UNIMPLEMENTED messages MUST appear in the same order as the
9374 * messages they respond to. Hence, never queue them.
9376 ssh2_pkt_send_noqueue(ssh
, pktout
);
9380 * Handle the top-level SSH-2 protocol.
9382 static void ssh2_protocol_setup(Ssh ssh
)
9387 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
9389 for (i
= 0; i
< 256; i
++)
9390 ssh
->packet_dispatch
[i
] = ssh2_msg_something_unimplemented
;
9393 * Any message we actually understand, we set to NULL so that
9394 * the coroutines will get it.
9396 ssh
->packet_dispatch
[SSH2_MSG_UNIMPLEMENTED
] = NULL
;
9397 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_REQUEST
] = NULL
;
9398 ssh
->packet_dispatch
[SSH2_MSG_SERVICE_ACCEPT
] = NULL
;
9399 ssh
->packet_dispatch
[SSH2_MSG_KEXINIT
] = NULL
;
9400 ssh
->packet_dispatch
[SSH2_MSG_NEWKEYS
] = NULL
;
9401 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_INIT
] = NULL
;
9402 ssh
->packet_dispatch
[SSH2_MSG_KEXDH_REPLY
] = NULL
;
9403 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
9404 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
9405 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_INIT
] = NULL
;
9406 ssh
->packet_dispatch
[SSH2_MSG_KEX_DH_GEX_REPLY
] = NULL
;
9407 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_REQUEST
] = NULL
;
9408 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_FAILURE
] = NULL
;
9409 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_SUCCESS
] = NULL
;
9410 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_BANNER
] = NULL
;
9411 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_PK_OK
] = NULL
;
9412 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
9413 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
9414 ssh
->packet_dispatch
[SSH2_MSG_USERAUTH_INFO_RESPONSE
] = NULL
;
9415 ssh
->packet_dispatch
[SSH2_MSG_GLOBAL_REQUEST
] = NULL
;
9416 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_SUCCESS
] = NULL
;
9417 ssh
->packet_dispatch
[SSH2_MSG_REQUEST_FAILURE
] = NULL
;
9418 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN
] = NULL
;
9419 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
] = NULL
;
9420 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_OPEN_FAILURE
] = NULL
;
9421 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_WINDOW_ADJUST
] = NULL
;
9422 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_DATA
] = NULL
;
9423 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EXTENDED_DATA
] = NULL
;
9424 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_EOF
] = NULL
;
9425 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_CLOSE
] = NULL
;
9426 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_REQUEST
] = NULL
;
9427 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_SUCCESS
] = NULL
;
9428 ssh
->packet_dispatch
[SSH2_MSG_CHANNEL_FAILURE
] = NULL
;
9431 * These special message types we install handlers for.
9433 ssh
->packet_dispatch
[SSH2_MSG_DISCONNECT
] = ssh2_msg_disconnect
;
9434 ssh
->packet_dispatch
[SSH2_MSG_IGNORE
] = ssh_msg_ignore
; /* shared with SSH-1 */
9435 ssh
->packet_dispatch
[SSH2_MSG_DEBUG
] = ssh2_msg_debug
;
9438 static void ssh2_timer(void *ctx
, long now
)
9442 if (ssh
->state
== SSH_STATE_CLOSED
)
9445 if (!ssh
->kex_in_progress
&& conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != 0 &&
9446 now
- ssh
->next_rekey
>= 0) {
9447 do_ssh2_transport(ssh
, "timeout", -1, NULL
);
9451 static void ssh2_protocol(Ssh ssh
, void *vin
, int inlen
,
9452 struct Packet
*pktin
)
9454 unsigned char *in
= (unsigned char *)vin
;
9455 if (ssh
->state
== SSH_STATE_CLOSED
)
9459 ssh
->incoming_data_size
+= pktin
->encrypted_len
;
9460 if (!ssh
->kex_in_progress
&&
9461 ssh
->max_data_size
!= 0 &&
9462 ssh
->incoming_data_size
> ssh
->max_data_size
)
9463 do_ssh2_transport(ssh
, "too much data received", -1, NULL
);
9466 if (pktin
&& ssh
->packet_dispatch
[pktin
->type
]) {
9467 ssh
->packet_dispatch
[pktin
->type
](ssh
, pktin
);
9471 if (!ssh
->protocol_initial_phase_done
||
9472 (pktin
&& pktin
->type
>= 20 && pktin
->type
< 50)) {
9473 if (do_ssh2_transport(ssh
, in
, inlen
, pktin
) &&
9474 !ssh
->protocol_initial_phase_done
) {
9475 ssh
->protocol_initial_phase_done
= TRUE
;
9477 * Allow authconn to initialise itself.
9479 do_ssh2_authconn(ssh
, NULL
, 0, NULL
);
9482 do_ssh2_authconn(ssh
, in
, inlen
, pktin
);
9486 static void ssh_cache_conf_values(Ssh ssh
)
9488 ssh
->logomitdata
= conf_get_int(ssh
->conf
, CONF_logomitdata
);
9492 * Called to set up the connection.
9494 * Returns an error message, or NULL on success.
9496 static const char *ssh_init(void *frontend_handle
, void **backend_handle
,
9497 Conf
*conf
, char *host
, int port
, char **realhost
,
9498 int nodelay
, int keepalive
)
9503 ssh
= snew(struct ssh_tag
);
9504 ssh
->conf
= conf_copy(conf
);
9505 ssh_cache_conf_values(ssh
);
9506 ssh
->version
= 0; /* when not ready yet */
9509 ssh
->v1_cipher_ctx
= NULL
;
9510 ssh
->crcda_ctx
= NULL
;
9511 ssh
->cscipher
= NULL
;
9512 ssh
->cs_cipher_ctx
= NULL
;
9513 ssh
->sccipher
= NULL
;
9514 ssh
->sc_cipher_ctx
= NULL
;
9516 ssh
->cs_mac_ctx
= NULL
;
9518 ssh
->sc_mac_ctx
= NULL
;
9520 ssh
->cs_comp_ctx
= NULL
;
9522 ssh
->sc_comp_ctx
= NULL
;
9524 ssh
->kex_ctx
= NULL
;
9525 ssh
->hostkey
= NULL
;
9527 ssh
->close_expected
= FALSE
;
9528 ssh
->clean_exit
= FALSE
;
9529 ssh
->state
= SSH_STATE_PREPACKET
;
9530 ssh
->size_needed
= FALSE
;
9531 ssh
->eof_needed
= FALSE
;
9534 ssh
->deferred_send_data
= NULL
;
9535 ssh
->deferred_len
= 0;
9536 ssh
->deferred_size
= 0;
9537 ssh
->fallback_cmd
= 0;
9538 ssh
->pkt_kctx
= SSH2_PKTCTX_NOKEX
;
9539 ssh
->pkt_actx
= SSH2_PKTCTX_NOAUTH
;
9540 ssh
->x11disp
= NULL
;
9541 ssh
->v1_compressing
= FALSE
;
9542 ssh
->v2_outgoing_sequence
= 0;
9543 ssh
->ssh1_rdpkt_crstate
= 0;
9544 ssh
->ssh2_rdpkt_crstate
= 0;
9545 ssh
->ssh_gotdata_crstate
= 0;
9546 ssh
->do_ssh1_connection_crstate
= 0;
9547 ssh
->do_ssh_init_state
= NULL
;
9548 ssh
->do_ssh1_login_state
= NULL
;
9549 ssh
->do_ssh2_transport_state
= NULL
;
9550 ssh
->do_ssh2_authconn_state
= NULL
;
9553 ssh
->mainchan
= NULL
;
9554 ssh
->throttled_all
= 0;
9555 ssh
->v1_stdout_throttling
= 0;
9557 ssh
->queuelen
= ssh
->queuesize
= 0;
9558 ssh
->queueing
= FALSE
;
9559 ssh
->qhead
= ssh
->qtail
= NULL
;
9560 ssh
->deferred_rekey_reason
= NULL
;
9561 bufchain_init(&ssh
->queued_incoming_data
);
9562 ssh
->frozen
= FALSE
;
9563 ssh
->username
= NULL
;
9564 ssh
->sent_console_eof
= FALSE
;
9565 ssh
->got_pty
= FALSE
;
9567 *backend_handle
= ssh
;
9570 if (crypto_startup() == 0)
9571 return "Microsoft high encryption pack not installed!";
9574 ssh
->frontend
= frontend_handle
;
9575 ssh
->term_width
= conf_get_int(ssh
->conf
, CONF_width
);
9576 ssh
->term_height
= conf_get_int(ssh
->conf
, CONF_height
);
9578 ssh
->channels
= NULL
;
9579 ssh
->rportfwds
= NULL
;
9580 ssh
->portfwds
= NULL
;
9585 ssh
->conn_throttle_count
= 0;
9586 ssh
->overall_bufsize
= 0;
9587 ssh
->fallback_cmd
= 0;
9589 ssh
->protocol
= NULL
;
9591 ssh
->protocol_initial_phase_done
= FALSE
;
9595 ssh
->incoming_data_size
= ssh
->outgoing_data_size
=
9596 ssh
->deferred_data_size
= 0L;
9597 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9598 CONF_ssh_rekey_data
));
9599 ssh
->kex_in_progress
= FALSE
;
9602 ssh
->gsslibs
= NULL
;
9605 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
, keepalive
);
9614 static void ssh_free(void *handle
)
9616 Ssh ssh
= (Ssh
) handle
;
9617 struct ssh_channel
*c
;
9618 struct ssh_rportfwd
*pf
;
9620 if (ssh
->v1_cipher_ctx
)
9621 ssh
->cipher
->free_context(ssh
->v1_cipher_ctx
);
9622 if (ssh
->cs_cipher_ctx
)
9623 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
9624 if (ssh
->sc_cipher_ctx
)
9625 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
9626 if (ssh
->cs_mac_ctx
)
9627 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
9628 if (ssh
->sc_mac_ctx
)
9629 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
9630 if (ssh
->cs_comp_ctx
) {
9632 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
9634 zlib_compress_cleanup(ssh
->cs_comp_ctx
);
9636 if (ssh
->sc_comp_ctx
) {
9638 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
9640 zlib_decompress_cleanup(ssh
->sc_comp_ctx
);
9643 dh_cleanup(ssh
->kex_ctx
);
9644 sfree(ssh
->savedhost
);
9646 while (ssh
->queuelen
-- > 0)
9647 ssh_free_packet(ssh
->queue
[ssh
->queuelen
]);
9650 while (ssh
->qhead
) {
9651 struct queued_handler
*qh
= ssh
->qhead
;
9652 ssh
->qhead
= qh
->next
;
9655 ssh
->qhead
= ssh
->qtail
= NULL
;
9657 if (ssh
->channels
) {
9658 while ((c
= delpos234(ssh
->channels
, 0)) != NULL
) {
9661 if (c
->u
.x11
.s
!= NULL
)
9662 x11_close(c
->u
.x11
.s
);
9665 case CHAN_SOCKDATA_DORMANT
:
9666 if (c
->u
.pfd
.s
!= NULL
)
9667 pfd_close(c
->u
.pfd
.s
);
9672 freetree234(ssh
->channels
);
9673 ssh
->channels
= NULL
;
9676 if (ssh
->rportfwds
) {
9677 while ((pf
= delpos234(ssh
->rportfwds
, 0)) != NULL
)
9679 freetree234(ssh
->rportfwds
);
9680 ssh
->rportfwds
= NULL
;
9682 sfree(ssh
->deferred_send_data
);
9684 x11_free_display(ssh
->x11disp
);
9685 sfree(ssh
->do_ssh_init_state
);
9686 sfree(ssh
->do_ssh1_login_state
);
9687 sfree(ssh
->do_ssh2_transport_state
);
9688 sfree(ssh
->do_ssh2_authconn_state
);
9691 sfree(ssh
->fullhostname
);
9692 if (ssh
->crcda_ctx
) {
9693 crcda_free_context(ssh
->crcda_ctx
);
9694 ssh
->crcda_ctx
= NULL
;
9697 ssh_do_close(ssh
, TRUE
);
9698 expire_timer_context(ssh
);
9700 pinger_free(ssh
->pinger
);
9701 bufchain_clear(&ssh
->queued_incoming_data
);
9702 sfree(ssh
->username
);
9703 conf_free(ssh
->conf
);
9706 ssh_gss_cleanup(ssh
->gsslibs
);
9714 * Reconfigure the SSH backend.
9716 static void ssh_reconfig(void *handle
, Conf
*conf
)
9718 Ssh ssh
= (Ssh
) handle
;
9719 char *rekeying
= NULL
, rekey_mandatory
= FALSE
;
9720 unsigned long old_max_data_size
;
9723 pinger_reconfig(ssh
->pinger
, ssh
->conf
, conf
);
9725 ssh_setup_portfwd(ssh
, conf
);
9727 rekey_time
= conf_get_int(conf
, CONF_ssh_rekey_time
);
9728 if (conf_get_int(ssh
->conf
, CONF_ssh_rekey_time
) != rekey_time
&&
9730 long new_next
= ssh
->last_rekey
+ rekey_time
*60*TICKSPERSEC
;
9731 long now
= GETTICKCOUNT();
9733 if (new_next
- now
< 0) {
9734 rekeying
= "timeout shortened";
9736 ssh
->next_rekey
= schedule_timer(new_next
- now
, ssh2_timer
, ssh
);
9740 old_max_data_size
= ssh
->max_data_size
;
9741 ssh
->max_data_size
= parse_blocksize(conf_get_str(ssh
->conf
,
9742 CONF_ssh_rekey_data
));
9743 if (old_max_data_size
!= ssh
->max_data_size
&&
9744 ssh
->max_data_size
!= 0) {
9745 if (ssh
->outgoing_data_size
> ssh
->max_data_size
||
9746 ssh
->incoming_data_size
> ssh
->max_data_size
)
9747 rekeying
= "data limit lowered";
9750 if (conf_get_int(ssh
->conf
, CONF_compression
) !=
9751 conf_get_int(conf
, CONF_compression
)) {
9752 rekeying
= "compression setting changed";
9753 rekey_mandatory
= TRUE
;
9756 for (i
= 0; i
< CIPHER_MAX
; i
++)
9757 if (conf_get_int_int(ssh
->conf
, CONF_ssh_cipherlist
, i
) !=
9758 conf_get_int_int(conf
, CONF_ssh_cipherlist
, i
)) {
9759 rekeying
= "cipher settings changed";
9760 rekey_mandatory
= TRUE
;
9762 if (conf_get_int(ssh
->conf
, CONF_ssh2_des_cbc
) !=
9763 conf_get_int(conf
, CONF_ssh2_des_cbc
)) {
9764 rekeying
= "cipher settings changed";
9765 rekey_mandatory
= TRUE
;
9768 conf_free(ssh
->conf
);
9769 ssh
->conf
= conf_copy(conf
);
9770 ssh_cache_conf_values(ssh
);
9773 if (!ssh
->kex_in_progress
) {
9774 do_ssh2_transport(ssh
, rekeying
, -1, NULL
);
9775 } else if (rekey_mandatory
) {
9776 ssh
->deferred_rekey_reason
= rekeying
;
9782 * Called to send data down the SSH connection.
9784 static int ssh_send(void *handle
, char *buf
, int len
)
9786 Ssh ssh
= (Ssh
) handle
;
9788 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9791 ssh
->protocol(ssh
, (unsigned char *)buf
, len
, 0);
9793 return ssh_sendbuffer(ssh
);
9797 * Called to query the current amount of buffered stdin data.
9799 static int ssh_sendbuffer(void *handle
)
9801 Ssh ssh
= (Ssh
) handle
;
9804 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
9808 * If the SSH socket itself has backed up, add the total backup
9809 * size on that to any individual buffer on the stdin channel.
9812 if (ssh
->throttled_all
)
9813 override_value
= ssh
->overall_bufsize
;
9815 if (ssh
->version
== 1) {
9816 return override_value
;
9817 } else if (ssh
->version
== 2) {
9819 return override_value
;
9821 return (override_value
+
9822 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
9829 * Called to set the size of the window from SSH's POV.
9831 static void ssh_size(void *handle
, int width
, int height
)
9833 Ssh ssh
= (Ssh
) handle
;
9834 struct Packet
*pktout
;
9836 ssh
->term_width
= width
;
9837 ssh
->term_height
= height
;
9839 switch (ssh
->state
) {
9840 case SSH_STATE_BEFORE_SIZE
:
9841 case SSH_STATE_PREPACKET
:
9842 case SSH_STATE_CLOSED
:
9843 break; /* do nothing */
9844 case SSH_STATE_INTERMED
:
9845 ssh
->size_needed
= TRUE
; /* buffer for later */
9847 case SSH_STATE_SESSION
:
9848 if (!conf_get_int(ssh
->conf
, CONF_nopty
)) {
9849 if (ssh
->version
== 1) {
9850 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
9851 PKT_INT
, ssh
->term_height
,
9852 PKT_INT
, ssh
->term_width
,
9853 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
9854 } else if (ssh
->mainchan
) {
9855 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9856 ssh2_pkt_adduint32(pktout
, ssh
->mainchan
->remoteid
);
9857 ssh2_pkt_addstring(pktout
, "window-change");
9858 ssh2_pkt_addbool(pktout
, 0);
9859 ssh2_pkt_adduint32(pktout
, ssh
->term_width
);
9860 ssh2_pkt_adduint32(pktout
, ssh
->term_height
);
9861 ssh2_pkt_adduint32(pktout
, 0);
9862 ssh2_pkt_adduint32(pktout
, 0);
9863 ssh2_pkt_send(ssh
, pktout
);
9871 * Return a list of the special codes that make sense in this
9874 static const struct telnet_special
*ssh_get_specials(void *handle
)
9876 static const struct telnet_special ssh1_ignore_special
[] = {
9877 {"IGNORE message", TS_NOP
}
9879 static const struct telnet_special ssh2_ignore_special
[] = {
9880 {"IGNORE message", TS_NOP
},
9882 static const struct telnet_special ssh2_rekey_special
[] = {
9883 {"Repeat key exchange", TS_REKEY
},
9885 static const struct telnet_special ssh2_session_specials
[] = {
9888 /* These are the signal names defined by RFC 4254.
9889 * They include all the ISO C signals, but are a subset of the POSIX
9890 * required signals. */
9891 {"SIGINT (Interrupt)", TS_SIGINT
},
9892 {"SIGTERM (Terminate)", TS_SIGTERM
},
9893 {"SIGKILL (Kill)", TS_SIGKILL
},
9894 {"SIGQUIT (Quit)", TS_SIGQUIT
},
9895 {"SIGHUP (Hangup)", TS_SIGHUP
},
9896 {"More signals", TS_SUBMENU
},
9897 {"SIGABRT", TS_SIGABRT
}, {"SIGALRM", TS_SIGALRM
},
9898 {"SIGFPE", TS_SIGFPE
}, {"SIGILL", TS_SIGILL
},
9899 {"SIGPIPE", TS_SIGPIPE
}, {"SIGSEGV", TS_SIGSEGV
},
9900 {"SIGUSR1", TS_SIGUSR1
}, {"SIGUSR2", TS_SIGUSR2
},
9903 static const struct telnet_special specials_end
[] = {
9906 /* XXX review this length for any changes: */
9907 static struct telnet_special ssh_specials
[lenof(ssh2_ignore_special
) +
9908 lenof(ssh2_rekey_special
) +
9909 lenof(ssh2_session_specials
) +
9910 lenof(specials_end
)];
9911 Ssh ssh
= (Ssh
) handle
;
9913 #define ADD_SPECIALS(name) \
9915 assert((i + lenof(name)) <= lenof(ssh_specials)); \
9916 memcpy(&ssh_specials[i], name, sizeof name); \
9920 if (ssh
->version
== 1) {
9921 /* Don't bother offering IGNORE if we've decided the remote
9922 * won't cope with it, since we wouldn't bother sending it if
9924 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
9925 ADD_SPECIALS(ssh1_ignore_special
);
9926 } else if (ssh
->version
== 2) {
9927 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
))
9928 ADD_SPECIALS(ssh2_ignore_special
);
9929 if (!(ssh
->remote_bugs
& BUG_SSH2_REKEY
))
9930 ADD_SPECIALS(ssh2_rekey_special
);
9932 ADD_SPECIALS(ssh2_session_specials
);
9933 } /* else we're not ready yet */
9936 ADD_SPECIALS(specials_end
);
9937 return ssh_specials
;
9945 * Send special codes. TS_EOF is useful for `plink', so you
9946 * can send an EOF and collect resulting output (e.g. `plink
9949 static void ssh_special(void *handle
, Telnet_Special code
)
9951 Ssh ssh
= (Ssh
) handle
;
9952 struct Packet
*pktout
;
9954 if (code
== TS_EOF
) {
9955 if (ssh
->state
!= SSH_STATE_SESSION
) {
9957 * Buffer the EOF in case we are pre-SESSION, so we can
9958 * send it as soon as we reach SESSION.
9961 ssh
->eof_needed
= TRUE
;
9964 if (ssh
->version
== 1) {
9965 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
9966 } else if (ssh
->mainchan
) {
9967 sshfwd_write_eof(ssh
->mainchan
);
9968 ssh
->send_ok
= 0; /* now stop trying to read from stdin */
9970 logevent("Sent EOF message");
9971 } else if (code
== TS_PING
|| code
== TS_NOP
) {
9972 if (ssh
->state
== SSH_STATE_CLOSED
9973 || ssh
->state
== SSH_STATE_PREPACKET
) return;
9974 if (ssh
->version
== 1) {
9975 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
9976 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
9978 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH2_IGNORE
)) {
9979 pktout
= ssh2_pkt_init(SSH2_MSG_IGNORE
);
9980 ssh2_pkt_addstring_start(pktout
);
9981 ssh2_pkt_send_noqueue(ssh
, pktout
);
9984 } else if (code
== TS_REKEY
) {
9985 if (!ssh
->kex_in_progress
&& ssh
->version
== 2) {
9986 do_ssh2_transport(ssh
, "at user request", -1, NULL
);
9988 } else if (code
== TS_BRK
) {
9989 if (ssh
->state
== SSH_STATE_CLOSED
9990 || ssh
->state
== SSH_STATE_PREPACKET
) return;
9991 if (ssh
->version
== 1) {
9992 logevent("Unable to send BREAK signal in SSH-1");
9993 } else if (ssh
->mainchan
) {
9994 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
9995 ssh2_pkt_adduint32(pktout
, ssh
->mainchan
->remoteid
);
9996 ssh2_pkt_addstring(pktout
, "break");
9997 ssh2_pkt_addbool(pktout
, 0);
9998 ssh2_pkt_adduint32(pktout
, 0); /* default break length */
9999 ssh2_pkt_send(ssh
, pktout
);
10002 /* Is is a POSIX signal? */
10003 char *signame
= NULL
;
10004 if (code
== TS_SIGABRT
) signame
= "ABRT";
10005 if (code
== TS_SIGALRM
) signame
= "ALRM";
10006 if (code
== TS_SIGFPE
) signame
= "FPE";
10007 if (code
== TS_SIGHUP
) signame
= "HUP";
10008 if (code
== TS_SIGILL
) signame
= "ILL";
10009 if (code
== TS_SIGINT
) signame
= "INT";
10010 if (code
== TS_SIGKILL
) signame
= "KILL";
10011 if (code
== TS_SIGPIPE
) signame
= "PIPE";
10012 if (code
== TS_SIGQUIT
) signame
= "QUIT";
10013 if (code
== TS_SIGSEGV
) signame
= "SEGV";
10014 if (code
== TS_SIGTERM
) signame
= "TERM";
10015 if (code
== TS_SIGUSR1
) signame
= "USR1";
10016 if (code
== TS_SIGUSR2
) signame
= "USR2";
10017 /* The SSH-2 protocol does in principle support arbitrary named
10018 * signals, including signame@domain, but we don't support those. */
10020 /* It's a signal. */
10021 if (ssh
->version
== 2 && ssh
->mainchan
) {
10022 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
10023 ssh2_pkt_adduint32(pktout
, ssh
->mainchan
->remoteid
);
10024 ssh2_pkt_addstring(pktout
, "signal");
10025 ssh2_pkt_addbool(pktout
, 0);
10026 ssh2_pkt_addstring(pktout
, signame
);
10027 ssh2_pkt_send(ssh
, pktout
);
10028 logeventf(ssh
, "Sent signal SIG%s", signame
);
10031 /* Never heard of it. Do nothing */
10036 void *new_sock_channel(void *handle
, Socket s
)
10038 Ssh ssh
= (Ssh
) handle
;
10039 struct ssh_channel
*c
;
10040 c
= snew(struct ssh_channel
);
10043 ssh2_channel_init(c
);
10044 c
->halfopen
= TRUE
;
10045 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
10047 add234(ssh
->channels
, c
);
10052 * This is called when stdout/stderr (the entity to which
10053 * from_backend sends data) manages to clear some backlog.
10055 static void ssh_unthrottle(void *handle
, int bufsize
)
10057 Ssh ssh
= (Ssh
) handle
;
10060 if (ssh
->version
== 1) {
10061 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
10062 ssh
->v1_stdout_throttling
= 0;
10063 ssh_throttle_conn(ssh
, -1);
10066 if (ssh
->mainchan
) {
10067 ssh2_set_window(ssh
->mainchan
,
10068 bufsize
< ssh
->mainchan
->v
.v2
.locmaxwin ?
10069 ssh
->mainchan
->v
.v2
.locmaxwin
- bufsize
: 0);
10070 if (conf_get_int(ssh
->conf
, CONF_ssh_simple
))
10073 buflimit
= ssh
->mainchan
->v
.v2
.locmaxwin
;
10074 if (ssh
->mainchan
->throttling_conn
&& bufsize
<= buflimit
) {
10075 ssh
->mainchan
->throttling_conn
= 0;
10076 ssh_throttle_conn(ssh
, -1);
10082 * Now process any SSH connection data that was stashed in our
10083 * queue while we were frozen.
10085 ssh_process_queued_incoming_data(ssh
);
10088 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
10090 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
10092 struct Packet
*pktout
;
10094 logeventf(ssh
, "Opening forwarded connection to %s:%d", hostname
, port
);
10096 if (ssh
->version
== 1) {
10097 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
10098 PKT_INT
, c
->localid
,
10101 /* PKT_STR, <org:orgport>, */
10104 pktout
= ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
10105 ssh2_pkt_addstring(pktout
, "direct-tcpip");
10106 ssh2_pkt_adduint32(pktout
, c
->localid
);
10107 ssh2_pkt_adduint32(pktout
, c
->v
.v2
.locwindow
);/* our window size */
10108 ssh2_pkt_adduint32(pktout
, OUR_V2_MAXPKT
); /* our max pkt size */
10109 ssh2_pkt_addstring(pktout
, hostname
);
10110 ssh2_pkt_adduint32(pktout
, port
);
10112 * We make up values for the originator data; partly it's
10113 * too much hassle to keep track, and partly I'm not
10114 * convinced the server should be told details like that
10115 * about my local network configuration.
10116 * The "originator IP address" is syntactically a numeric
10117 * IP address, and some servers (e.g., Tectia) get upset
10118 * if it doesn't match this syntax.
10120 ssh2_pkt_addstring(pktout
, "0.0.0.0");
10121 ssh2_pkt_adduint32(pktout
, 0);
10122 ssh2_pkt_send(ssh
, pktout
);
10126 static int ssh_connected(void *handle
)
10128 Ssh ssh
= (Ssh
) handle
;
10129 return ssh
->s
!= NULL
;
10132 static int ssh_sendok(void *handle
)
10134 Ssh ssh
= (Ssh
) handle
;
10135 return ssh
->send_ok
;
10138 static int ssh_ldisc(void *handle
, int option
)
10140 Ssh ssh
= (Ssh
) handle
;
10141 if (option
== LD_ECHO
)
10142 return ssh
->echoing
;
10143 if (option
== LD_EDIT
)
10144 return ssh
->editing
;
10148 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
10150 Ssh ssh
= (Ssh
) handle
;
10151 ssh
->ldisc
= ldisc
;
10154 static void ssh_provide_logctx(void *handle
, void *logctx
)
10156 Ssh ssh
= (Ssh
) handle
;
10157 ssh
->logctx
= logctx
;
10160 static int ssh_return_exitcode(void *handle
)
10162 Ssh ssh
= (Ssh
) handle
;
10163 if (ssh
->s
!= NULL
)
10166 return (ssh
->exitcode
>= 0 ? ssh
->exitcode
: INT_MAX
);
10170 * cfg_info for SSH is the currently running version of the
10171 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
10173 static int ssh_cfg_info(void *handle
)
10175 Ssh ssh
= (Ssh
) handle
;
10176 return ssh
->version
;
10180 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
10181 * that fails. This variable is the means by which scp.c can reach
10182 * into the SSH code and find out which one it got.
10184 extern int ssh_fallback_cmd(void *handle
)
10186 Ssh ssh
= (Ssh
) handle
;
10187 return ssh
->fallback_cmd
;
10190 Backend ssh_backend
= {
10200 ssh_return_exitcode
,
10204 ssh_provide_logctx
,