23 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
24 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
25 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
26 #define SSH1_CMSG_USER 4 /* 0x4 */
27 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
28 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
29 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
30 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
31 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
32 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
33 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
34 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
35 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
36 #define SSH1_SMSG_FAILURE 15 /* 0xf */
37 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
38 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
39 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
40 #define SSH1_CMSG_EOF 19 /* 0x13 */
41 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
42 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
43 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
44 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
45 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
46 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
47 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
48 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
49 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
50 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
51 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
52 #define SSH1_MSG_IGNORE 32 /* 0x20 */
53 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
54 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
55 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
56 #define SSH1_MSG_DEBUG 36 /* 0x24 */
57 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
58 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
59 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
60 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
61 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
62 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
63 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
65 #define SSH1_AUTH_TIS 5 /* 0x5 */
66 #define SSH1_AUTH_CCARD 16 /* 0x10 */
68 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
69 /* Mask for protoflags we will echo back to server if seen */
70 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
72 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
73 #define SSH2_MSG_IGNORE 2 /* 0x2 */
74 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
75 #define SSH2_MSG_DEBUG 4 /* 0x4 */
76 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
77 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
78 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
79 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
80 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
81 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
82 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
83 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
84 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
85 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
86 #define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */
87 #define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */
88 #define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */
89 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
96 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
97 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
98 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
99 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
100 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
101 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
102 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
103 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
104 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
105 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
106 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
107 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
108 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
109 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
110 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
113 * Packet type contexts, so that ssh2_pkt_type can correctly decode
114 * the ambiguous type numbers back into the correct type strings.
124 SSH2_PKTCTX_PUBLICKEY,
125 SSH2_PKTCTX_PASSWORD,
129 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
130 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
131 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
132 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
133 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
134 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
135 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
136 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
137 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
138 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
139 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
140 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
141 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
142 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
143 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
145 static const char *const ssh2_disconnect_reasons[] = {
147 "host not allowed to connect",
149 "key exchange failed",
150 "host authentication failed",
153 "service not available",
154 "protocol version not supported",
155 "host key not verifiable",
158 "too many connections",
159 "auth cancelled by user",
160 "no more auth methods available",
164 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
165 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
166 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
167 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
169 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
172 * Various remote-bug flags.
174 #define BUG_CHOKES_ON_SSH1_IGNORE 1
175 #define BUG_SSH2_HMAC 2
176 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
177 #define BUG_CHOKES_ON_RSA 8
178 #define BUG_SSH2_RSA_PADDING 16
179 #define BUG_SSH2_DERIVEKEY 32
180 #define BUG_SSH2_REKEY 64
181 #define BUG_SSH2_PK_SESSIONID 128
184 * Codes for terminal modes.
185 * Most of these are the same in SSH-1 and SSH-2.
186 * This list is derived from draft-ietf-secsh-connect-25 and
189 static const struct {
190 const char* const mode;
192 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
194 /* "V" prefix discarded for special characters relative to SSH specs */
195 { "INTR", 1, TTY_OP_CHAR },
196 { "QUIT", 2, TTY_OP_CHAR },
197 { "ERASE", 3, TTY_OP_CHAR },
198 { "KILL", 4, TTY_OP_CHAR },
199 { "EOF", 5, TTY_OP_CHAR },
200 { "EOL", 6, TTY_OP_CHAR },
201 { "EOL2", 7, TTY_OP_CHAR },
202 { "START", 8, TTY_OP_CHAR },
203 { "STOP", 9, TTY_OP_CHAR },
204 { "SUSP", 10, TTY_OP_CHAR },
205 { "DSUSP", 11, TTY_OP_CHAR },
206 { "REPRINT", 12, TTY_OP_CHAR },
207 { "WERASE", 13, TTY_OP_CHAR },
208 { "LNEXT", 14, TTY_OP_CHAR },
209 { "FLUSH", 15, TTY_OP_CHAR },
210 { "SWTCH", 16, TTY_OP_CHAR },
211 { "STATUS", 17, TTY_OP_CHAR },
212 { "DISCARD", 18, TTY_OP_CHAR },
213 { "IGNPAR", 30, TTY_OP_BOOL },
214 { "PARMRK", 31, TTY_OP_BOOL },
215 { "INPCK", 32, TTY_OP_BOOL },
216 { "ISTRIP", 33, TTY_OP_BOOL },
217 { "INLCR", 34, TTY_OP_BOOL },
218 { "IGNCR", 35, TTY_OP_BOOL },
219 { "ICRNL", 36, TTY_OP_BOOL },
220 { "IUCLC", 37, TTY_OP_BOOL },
221 { "IXON", 38, TTY_OP_BOOL },
222 { "IXANY", 39, TTY_OP_BOOL },
223 { "IXOFF", 40, TTY_OP_BOOL },
224 { "IMAXBEL", 41, TTY_OP_BOOL },
225 { "ISIG", 50, TTY_OP_BOOL },
226 { "ICANON", 51, TTY_OP_BOOL },
227 { "XCASE", 52, TTY_OP_BOOL },
228 { "ECHO", 53, TTY_OP_BOOL },
229 { "ECHOE", 54, TTY_OP_BOOL },
230 { "ECHOK", 55, TTY_OP_BOOL },
231 { "ECHONL", 56, TTY_OP_BOOL },
232 { "NOFLSH", 57, TTY_OP_BOOL },
233 { "TOSTOP", 58, TTY_OP_BOOL },
234 { "IEXTEN", 59, TTY_OP_BOOL },
235 { "ECHOCTL", 60, TTY_OP_BOOL },
236 { "ECHOKE", 61, TTY_OP_BOOL },
237 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
238 { "OPOST", 70, TTY_OP_BOOL },
239 { "OLCUC", 71, TTY_OP_BOOL },
240 { "ONLCR", 72, TTY_OP_BOOL },
241 { "OCRNL", 73, TTY_OP_BOOL },
242 { "ONOCR", 74, TTY_OP_BOOL },
243 { "ONLRET", 75, TTY_OP_BOOL },
244 { "CS7", 90, TTY_OP_BOOL },
245 { "CS8", 91, TTY_OP_BOOL },
246 { "PARENB", 92, TTY_OP_BOOL },
247 { "PARODD", 93, TTY_OP_BOOL }
250 /* Miscellaneous other tty-related constants. */
251 #define SSH_TTY_OP_END 0
252 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
253 #define SSH1_TTY_OP_ISPEED 192
254 #define SSH1_TTY_OP_OSPEED 193
255 #define SSH2_TTY_OP_ISPEED 128
256 #define SSH2_TTY_OP_OSPEED 129
258 /* Helper functions for parsing tty-related config. */
259 static unsigned int ssh_tty_parse_specchar(char *s)
264 ret = ctrlparse(s, &next);
265 if (!next) ret = s[0];
267 ret = 255; /* special value meaning "don't set" */
271 static unsigned int ssh_tty_parse_boolean(char *s)
273 if (stricmp(s, "yes") == 0 ||
274 stricmp(s, "on") == 0 ||
275 stricmp(s, "true") == 0 ||
276 stricmp(s, "+") == 0)
278 else if (stricmp(s, "no") == 0 ||
279 stricmp(s, "off") == 0 ||
280 stricmp(s, "false") == 0 ||
281 stricmp(s, "-") == 0)
282 return 0; /* false */
284 return (atoi(s) != 0);
287 #define translate(x) if (type == x) return #x
288 #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x
289 #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x
290 static char *ssh1_pkt_type(int type)
292 translate(SSH1_MSG_DISCONNECT);
293 translate(SSH1_SMSG_PUBLIC_KEY);
294 translate(SSH1_CMSG_SESSION_KEY);
295 translate(SSH1_CMSG_USER);
296 translate(SSH1_CMSG_AUTH_RSA);
297 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
298 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
299 translate(SSH1_CMSG_AUTH_PASSWORD);
300 translate(SSH1_CMSG_REQUEST_PTY);
301 translate(SSH1_CMSG_WINDOW_SIZE);
302 translate(SSH1_CMSG_EXEC_SHELL);
303 translate(SSH1_CMSG_EXEC_CMD);
304 translate(SSH1_SMSG_SUCCESS);
305 translate(SSH1_SMSG_FAILURE);
306 translate(SSH1_CMSG_STDIN_DATA);
307 translate(SSH1_SMSG_STDOUT_DATA);
308 translate(SSH1_SMSG_STDERR_DATA);
309 translate(SSH1_CMSG_EOF);
310 translate(SSH1_SMSG_EXIT_STATUS);
311 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
312 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
313 translate(SSH1_MSG_CHANNEL_DATA);
314 translate(SSH1_MSG_CHANNEL_CLOSE);
315 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
316 translate(SSH1_SMSG_X11_OPEN);
317 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
318 translate(SSH1_MSG_PORT_OPEN);
319 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
320 translate(SSH1_SMSG_AGENT_OPEN);
321 translate(SSH1_MSG_IGNORE);
322 translate(SSH1_CMSG_EXIT_CONFIRMATION);
323 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
324 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
325 translate(SSH1_MSG_DEBUG);
326 translate(SSH1_CMSG_REQUEST_COMPRESSION);
327 translate(SSH1_CMSG_AUTH_TIS);
328 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
329 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
330 translate(SSH1_CMSG_AUTH_CCARD);
331 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
332 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
335 static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type)
337 translate(SSH2_MSG_DISCONNECT);
338 translate(SSH2_MSG_IGNORE);
339 translate(SSH2_MSG_UNIMPLEMENTED);
340 translate(SSH2_MSG_DEBUG);
341 translate(SSH2_MSG_SERVICE_REQUEST);
342 translate(SSH2_MSG_SERVICE_ACCEPT);
343 translate(SSH2_MSG_KEXINIT);
344 translate(SSH2_MSG_NEWKEYS);
345 translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
346 translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
347 translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
348 translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
349 translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
350 translatek(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
351 translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX);
352 translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX);
353 translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX);
354 translate(SSH2_MSG_USERAUTH_REQUEST);
355 translate(SSH2_MSG_USERAUTH_FAILURE);
356 translate(SSH2_MSG_USERAUTH_SUCCESS);
357 translate(SSH2_MSG_USERAUTH_BANNER);
358 translatea(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
359 translatea(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
360 translatea(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
361 translatea(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
362 translate(SSH2_MSG_GLOBAL_REQUEST);
363 translate(SSH2_MSG_REQUEST_SUCCESS);
364 translate(SSH2_MSG_REQUEST_FAILURE);
365 translate(SSH2_MSG_CHANNEL_OPEN);
366 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
367 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
368 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
369 translate(SSH2_MSG_CHANNEL_DATA);
370 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
371 translate(SSH2_MSG_CHANNEL_EOF);
372 translate(SSH2_MSG_CHANNEL_CLOSE);
373 translate(SSH2_MSG_CHANNEL_REQUEST);
374 translate(SSH2_MSG_CHANNEL_SUCCESS);
375 translate(SSH2_MSG_CHANNEL_FAILURE);
381 /* Enumeration values for fields in SSH-1 packets */
383 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
384 /* These values are for communicating relevant semantics of
385 * fields to the packet logging code. */
386 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
390 * Coroutine mechanics for the sillier bits of the code. If these
391 * macros look impenetrable to you, you might find it helpful to
394 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
396 * which explains the theory behind these macros.
398 * In particular, if you are getting `case expression not constant'
399 * errors when building with MS Visual Studio, this is because MS's
400 * Edit and Continue debugging feature causes their compiler to
401 * violate ANSI C. To disable Edit and Continue debugging:
403 * - right-click ssh.c in the FileView
405 * - select the C/C++ tab and the General category
406 * - under `Debug info:', select anything _other_ than `Program
407 * Database for Edit and Continue'.
409 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
412 if (!ssh->t) ssh->t = snew(struct t); \
414 #define crFinish(z) } *crLine = 0; return (z); }
415 #define crFinishV } *crLine = 0; return; }
416 #define crReturn(z) \
418 *crLine =__LINE__; return (z); case __LINE__:;\
422 *crLine=__LINE__; return; case __LINE__:;\
424 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
425 #define crStopV do{ *crLine = 0; return; }while(0)
426 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
427 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
429 typedef struct ssh_tag *Ssh;
432 static struct Packet *ssh1_pkt_init(int pkt_type);
433 static struct Packet *ssh2_pkt_init(int pkt_type);
434 static void ssh_pkt_ensure(struct Packet *, int length);
435 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
436 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
437 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
438 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
439 static void ssh_pkt_addstring_start(struct Packet *);
440 static void ssh_pkt_addstring_str(struct Packet *, char *data);
441 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
442 static void ssh_pkt_addstring(struct Packet *, char *data);
443 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
444 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
445 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
446 static int ssh2_pkt_construct(Ssh, struct Packet *);
447 static void ssh2_pkt_send(Ssh, struct Packet *);
448 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
449 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
450 struct Packet *pktin);
451 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
452 struct Packet *pktin);
455 * Buffer management constants. There are several of these for
456 * various different purposes:
458 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
459 * on a local data stream before we throttle the whole SSH
460 * connection (in SSH-1 only). Throttling the whole connection is
461 * pretty drastic so we set this high in the hope it won't
464 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
465 * on the SSH connection itself before we defensively throttle
466 * _all_ local data streams. This is pretty drastic too (though
467 * thankfully unlikely in SSH-2 since the window mechanism should
468 * ensure that the server never has any need to throttle its end
469 * of the connection), so we set this high as well.
471 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
475 #define SSH1_BUFFER_LIMIT 32768
476 #define SSH_MAX_BACKLOG 32768
477 #define OUR_V2_WINSIZE 16384
478 #define OUR_V2_MAXPKT 0x4000UL
480 /* Maximum length of passwords/passphrases (arbitrary) */
481 #define SSH_MAX_PASSWORD_LEN 100
483 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
485 const static struct ssh_mac *macs[] = {
486 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
488 const static struct ssh_mac *buggymacs[] = {
489 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5
492 static void *ssh_comp_none_init(void)
496 static void ssh_comp_none_cleanup(void *handle)
499 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
500 unsigned char **outblock, int *outlen)
504 static int ssh_comp_none_disable(void *handle)
508 const static struct ssh_compress ssh_comp_none = {
510 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
511 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
512 ssh_comp_none_disable, NULL
514 extern const struct ssh_compress ssh_zlib;
515 const static struct ssh_compress *compressions[] = {
516 &ssh_zlib, &ssh_comp_none
519 enum { /* channel types */
524 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
528 * 2-3-4 tree storing channels.
531 Ssh ssh; /* pointer back to main context */
532 unsigned remoteid, localid;
534 /* True if we opened this channel but server hasn't confirmed. */
537 * In SSH-1, this value contains four bits:
539 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
540 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
541 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
542 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
544 * A channel is completely finished with when all four bits are set.
548 struct ssh1_data_channel {
551 struct ssh2_data_channel {
553 unsigned remwindow, remmaxpkt;
554 /* locwindow is signed so we can cope with excess data. */
559 struct ssh_agent_channel {
560 unsigned char *message;
561 unsigned char msglen[4];
562 unsigned lensofar, totallen;
564 struct ssh_x11_channel {
567 struct ssh_pfd_channel {
574 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
575 * use this structure in different ways, reflecting SSH-2's
576 * altogether saner approach to port forwarding.
578 * In SSH-1, you arrange a remote forwarding by sending the server
579 * the remote port number, and the local destination host:port.
580 * When a connection comes in, the server sends you back that
581 * host:port pair, and you connect to it. This is a ready-made
582 * security hole if you're not on the ball: a malicious server
583 * could send you back _any_ host:port pair, so if you trustingly
584 * connect to the address it gives you then you've just opened the
585 * entire inside of your corporate network just by connecting
586 * through it to a dodgy SSH server. Hence, we must store a list of
587 * host:port pairs we _are_ trying to forward to, and reject a
588 * connection request from the server if it's not in the list.
590 * In SSH-2, each side of the connection minds its own business and
591 * doesn't send unnecessary information to the other. You arrange a
592 * remote forwarding by sending the server just the remote port
593 * number. When a connection comes in, the server tells you which
594 * of its ports was connected to; and _you_ have to remember what
595 * local host:port pair went with that port number.
597 * Hence, in SSH-1 this structure is indexed by destination
598 * host:port pair, whereas in SSH-2 it is indexed by source port.
600 struct ssh_portfwd; /* forward declaration */
602 struct ssh_rportfwd {
603 unsigned sport, dport;
606 struct ssh_portfwd *pfrec;
608 #define free_rportfwd(pf) ( \
609 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
612 * Separately to the rportfwd tree (which is for looking up port
613 * open requests from the server), a tree of _these_ structures is
614 * used to keep track of all the currently open port forwardings,
615 * so that we can reconfigure in mid-session if the user requests
619 enum { DESTROY, KEEP, CREATE } status;
621 unsigned sport, dport;
624 struct ssh_rportfwd *remote;
628 #define free_portfwd(pf) ( \
629 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
630 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
633 long length; /* length of `data' actually used */
634 long forcepad; /* SSH-2: force padding to at least this length */
635 int type; /* only used for incoming packets */
636 unsigned long sequence; /* SSH-2 incoming sequence number */
637 unsigned char *data; /* allocated storage */
638 unsigned char *body; /* offset of payload within `data' */
639 long savedpos; /* temporary index into `data' (for strings) */
640 long maxlen; /* amount of storage allocated for `data' */
641 long encrypted_len; /* for SSH-2 total-size counting */
644 * State associated with packet logging
648 struct logblank_t *blanks;
651 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
652 struct Packet *pktin);
653 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
654 struct Packet *pktin);
655 static void ssh1_protocol_setup(Ssh ssh);
656 static void ssh2_protocol_setup(Ssh ssh);
657 static void ssh_size(void *handle, int width, int height);
658 static void ssh_special(void *handle, Telnet_Special);
659 static int ssh2_try_send(struct ssh_channel *c);
660 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
661 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
662 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
663 static int ssh_sendbuffer(void *handle);
664 static int ssh_do_close(Ssh ssh, int notify_exit);
665 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
666 static int ssh2_pkt_getbool(struct Packet *pkt);
667 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
668 static void ssh2_timer(void *ctx, long now);
669 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
670 struct Packet *pktin);
672 struct rdpkt1_state_tag {
673 long len, pad, biglen, to_read;
674 unsigned long realcrc, gotcrc;
678 struct Packet *pktin;
681 struct rdpkt2_state_tag {
682 long len, pad, payload, packetlen, maclen;
685 unsigned long incoming_sequence;
686 struct Packet *pktin;
689 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
690 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
692 struct queued_handler;
693 struct queued_handler {
695 chandler_fn_t handler;
697 struct queued_handler *next;
701 const struct plug_function_table *fn;
702 /* the above field _must_ be first in the structure */
712 unsigned char session_key[32];
714 int v1_remote_protoflags;
715 int v1_local_protoflags;
716 int agentfwd_enabled;
719 const struct ssh_cipher *cipher;
722 const struct ssh2_cipher *cscipher, *sccipher;
723 void *cs_cipher_ctx, *sc_cipher_ctx;
724 const struct ssh_mac *csmac, *scmac;
725 void *cs_mac_ctx, *sc_mac_ctx;
726 const struct ssh_compress *cscomp, *sccomp;
727 void *cs_comp_ctx, *sc_comp_ctx;
728 const struct ssh_kex *kex;
729 const struct ssh_signkey *hostkey;
730 unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN];
731 int v2_session_id_len;
737 int echoing, editing;
741 int ospeed, ispeed; /* temporaries */
742 int term_width, term_height;
744 tree234 *channels; /* indexed by local id */
745 struct ssh_channel *mainchan; /* primary session channel */
746 int ncmode; /* is primary channel direct-tcpip? */
751 tree234 *rportfwds, *portfwds;
755 SSH_STATE_BEFORE_SIZE,
761 int size_needed, eof_needed;
763 struct Packet **queue;
764 int queuelen, queuesize;
766 unsigned char *deferred_send_data;
767 int deferred_len, deferred_size;
770 * Gross hack: pscp will try to start SFTP but fall back to
771 * scp1 if that fails. This variable is the means by which
772 * scp.c can reach into the SSH code and find out which one it
777 bufchain banner; /* accumulates banners during do_ssh2_authconn */
785 int v1_throttle_count;
788 int v1_stdout_throttling;
789 unsigned long v2_outgoing_sequence;
791 int ssh1_rdpkt_crstate;
792 int ssh2_rdpkt_crstate;
793 int do_ssh_init_crstate;
794 int ssh_gotdata_crstate;
795 int do_ssh1_login_crstate;
796 int do_ssh1_connection_crstate;
797 int do_ssh2_transport_crstate;
798 int do_ssh2_authconn_crstate;
800 void *do_ssh_init_state;
801 void *do_ssh1_login_state;
802 void *do_ssh2_transport_state;
803 void *do_ssh2_authconn_state;
805 struct rdpkt1_state_tag rdpkt1_state;
806 struct rdpkt2_state_tag rdpkt2_state;
808 /* SSH-1 and SSH-2 use this for different things, but both use it */
809 int protocol_initial_phase_done;
811 void (*protocol) (Ssh ssh, void *vin, int inlen,
813 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
816 * We maintain a full _copy_ of a Config structure here, not
817 * merely a pointer to it. That way, when we're passed a new
818 * one for reconfiguration, we can check the differences and
819 * potentially reconfigure port forwardings etc in mid-session.
824 * Used to transfer data back from async callbacks.
826 void *agent_response;
827 int agent_response_len;
831 * The SSH connection can be set as `frozen', meaning we are
832 * not currently accepting incoming data from the network. This
833 * is slightly more serious than setting the _socket_ as
834 * frozen, because we may already have had data passed to us
835 * from the network which we need to delay processing until
836 * after the freeze is lifted, so we also need a bufchain to
840 bufchain queued_incoming_data;
843 * Dispatch table for packet types that we may have to deal
846 handler_fn_t packet_dispatch[256];
849 * Queues of one-off handler functions for success/failure
850 * indications from a request.
852 struct queued_handler *qhead, *qtail;
855 * This module deals with sending keepalives.
860 * Track incoming and outgoing data sizes and time, for
863 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
864 unsigned long max_data_size;
866 long next_rekey, last_rekey;
867 char *deferred_rekey_reason; /* points to STATIC string; don't free */
870 #define logevent(s) logevent(ssh->frontend, s)
872 /* logevent, only printf-formatted. */
873 static void logeventf(Ssh ssh, const char *fmt, ...)
879 buf = dupvprintf(fmt, ap);
885 #define bombout(msg) \
887 char *text = dupprintf msg; \
888 ssh_do_close(ssh, FALSE); \
890 connection_fatal(ssh->frontend, "%s", text); \
894 /* Functions to leave bits out of the SSH packet log file. */
896 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
898 if (ssh->cfg.logomitpass)
899 pkt->logmode = blanktype;
902 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
904 if (ssh->cfg.logomitdata)
905 pkt->logmode = blanktype;
908 static void end_log_omission(Ssh ssh, struct Packet *pkt)
910 pkt->logmode = PKTLOG_EMIT;
913 /* Helper function for common bits of parsing cfg.ttymodes. */
914 static void parse_ttymodes(Ssh ssh, char *modes,
915 void (*do_mode)(void *data, char *mode, char *val),
919 char *t = strchr(modes, '\t');
920 char *m = snewn(t-modes+1, char);
922 strncpy(m, modes, t-modes);
925 val = get_ttymode(ssh->frontend, m);
929 do_mode(data, m, val);
932 modes += strlen(modes) + 1;
936 static int ssh_channelcmp(void *av, void *bv)
938 struct ssh_channel *a = (struct ssh_channel *) av;
939 struct ssh_channel *b = (struct ssh_channel *) bv;
940 if (a->localid < b->localid)
942 if (a->localid > b->localid)
946 static int ssh_channelfind(void *av, void *bv)
948 unsigned *a = (unsigned *) av;
949 struct ssh_channel *b = (struct ssh_channel *) bv;
957 static int ssh_rportcmp_ssh1(void *av, void *bv)
959 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
960 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
962 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
963 return i < 0 ? -1 : +1;
964 if (a->dport > b->dport)
966 if (a->dport < b->dport)
971 static int ssh_rportcmp_ssh2(void *av, void *bv)
973 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
974 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
976 if (a->sport > b->sport)
978 if (a->sport < b->sport)
984 * Special form of strcmp which can cope with NULL inputs. NULL is
985 * defined to sort before even the empty string.
987 static int nullstrcmp(const char *a, const char *b)
989 if (a == NULL && b == NULL)
998 static int ssh_portcmp(void *av, void *bv)
1000 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
1001 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
1003 if (a->type > b->type)
1005 if (a->type < b->type)
1007 if (a->addressfamily > b->addressfamily)
1009 if (a->addressfamily < b->addressfamily)
1011 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
1012 return i < 0 ? -1 : +1;
1013 if (a->sport > b->sport)
1015 if (a->sport < b->sport)
1017 if (a->type != 'D') {
1018 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1019 return i < 0 ? -1 : +1;
1020 if (a->dport > b->dport)
1022 if (a->dport < b->dport)
1028 static int alloc_channel_id(Ssh ssh)
1030 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1031 unsigned low, high, mid;
1033 struct ssh_channel *c;
1036 * First-fit allocation of channel numbers: always pick the
1037 * lowest unused one. To do this, binary-search using the
1038 * counted B-tree to find the largest channel ID which is in a
1039 * contiguous sequence from the beginning. (Precisely
1040 * everything in that sequence must have ID equal to its tree
1041 * index plus CHANNEL_NUMBER_OFFSET.)
1043 tsize = count234(ssh->channels);
1047 while (high - low > 1) {
1048 mid = (high + low) / 2;
1049 c = index234(ssh->channels, mid);
1050 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1051 low = mid; /* this one is fine */
1053 high = mid; /* this one is past it */
1056 * Now low points to either -1, or the tree index of the
1057 * largest ID in the initial sequence.
1060 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1061 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1063 return low + 1 + CHANNEL_NUMBER_OFFSET;
1066 static void c_write_stderr(int trusted, const char *buf, int len)
1069 for (i = 0; i < len; i++)
1070 if (buf[i] != '\r' && (trusted || buf[i] == '\n' || (buf[i] & 0x60)))
1071 fputc(buf[i], stderr);
1074 static void c_write(Ssh ssh, const char *buf, int len)
1076 if (flags & FLAG_STDERR)
1077 c_write_stderr(1, buf, len);
1079 from_backend(ssh->frontend, 1, buf, len);
1082 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1084 if (flags & FLAG_STDERR)
1085 c_write_stderr(0, buf, len);
1087 from_backend_untrusted(ssh->frontend, buf, len);
1090 static void c_write_str(Ssh ssh, const char *buf)
1092 c_write(ssh, buf, strlen(buf));
1095 static void ssh_free_packet(struct Packet *pkt)
1100 static struct Packet *ssh_new_packet(void)
1102 struct Packet *pkt = snew(struct Packet);
1104 pkt->body = pkt->data = NULL;
1106 pkt->logmode = PKTLOG_EMIT;
1114 * Collect incoming data in the incoming packet buffer.
1115 * Decipher and verify the packet when it is completely read.
1116 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1117 * Update the *data and *datalen variables.
1118 * Return a Packet structure when a packet is completed.
1120 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1122 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1124 crBegin(ssh->ssh1_rdpkt_crstate);
1126 st->pktin = ssh_new_packet();
1128 st->pktin->type = 0;
1129 st->pktin->length = 0;
1131 for (st->i = st->len = 0; st->i < 4; st->i++) {
1132 while ((*datalen) == 0)
1134 st->len = (st->len << 8) + **data;
1135 (*data)++, (*datalen)--;
1138 st->pad = 8 - (st->len % 8);
1139 st->biglen = st->len + st->pad;
1140 st->pktin->length = st->len - 5;
1142 if (st->biglen < 0) {
1143 bombout(("Extremely large packet length from server suggests"
1144 " data stream corruption"));
1145 ssh_free_packet(st->pktin);
1149 st->pktin->maxlen = st->biglen;
1150 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1152 st->to_read = st->biglen;
1153 st->p = st->pktin->data;
1154 while (st->to_read > 0) {
1155 st->chunk = st->to_read;
1156 while ((*datalen) == 0)
1158 if (st->chunk > (*datalen))
1159 st->chunk = (*datalen);
1160 memcpy(st->p, *data, st->chunk);
1162 *datalen -= st->chunk;
1164 st->to_read -= st->chunk;
1167 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1168 st->biglen, NULL)) {
1169 bombout(("Network attack (CRC compensation) detected!"));
1170 ssh_free_packet(st->pktin);
1175 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1177 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1178 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1179 if (st->gotcrc != st->realcrc) {
1180 bombout(("Incorrect CRC received on packet"));
1181 ssh_free_packet(st->pktin);
1185 st->pktin->body = st->pktin->data + st->pad + 1;
1186 st->pktin->savedpos = 0;
1188 if (ssh->v1_compressing) {
1189 unsigned char *decompblk;
1191 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1192 st->pktin->body - 1, st->pktin->length + 1,
1193 &decompblk, &decomplen)) {
1194 bombout(("Zlib decompression encountered invalid data"));
1195 ssh_free_packet(st->pktin);
1199 if (st->pktin->maxlen < st->pad + decomplen) {
1200 st->pktin->maxlen = st->pad + decomplen;
1201 st->pktin->data = sresize(st->pktin->data,
1202 st->pktin->maxlen + APIEXTRA,
1204 st->pktin->body = st->pktin->data + st->pad + 1;
1207 memcpy(st->pktin->body - 1, decompblk, decomplen);
1209 st->pktin->length = decomplen - 1;
1212 st->pktin->type = st->pktin->body[-1];
1215 * Log incoming packet, possibly omitting sensitive fields.
1219 struct logblank_t blank;
1220 if (ssh->cfg.logomitdata) {
1221 int do_blank = FALSE, blank_prefix = 0;
1222 /* "Session data" packets - omit the data field */
1223 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1224 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1225 do_blank = TRUE; blank_prefix = 0;
1226 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1227 do_blank = TRUE; blank_prefix = 4;
1230 blank.offset = blank_prefix;
1231 blank.len = st->pktin->length;
1232 blank.type = PKTLOG_OMIT;
1236 log_packet(ssh->logctx,
1237 PKT_INCOMING, st->pktin->type,
1238 ssh1_pkt_type(st->pktin->type),
1239 st->pktin->body, st->pktin->length,
1243 crFinish(st->pktin);
1246 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1248 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1250 crBegin(ssh->ssh2_rdpkt_crstate);
1252 st->pktin = ssh_new_packet();
1254 st->pktin->type = 0;
1255 st->pktin->length = 0;
1257 st->cipherblk = ssh->sccipher->blksize;
1260 if (st->cipherblk < 8)
1263 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1266 * Acquire and decrypt the first block of the packet. This will
1267 * contain the length and padding details.
1269 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1270 while ((*datalen) == 0)
1272 st->pktin->data[st->i] = *(*data)++;
1277 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1278 st->pktin->data, st->cipherblk);
1281 * Now get the length and padding figures.
1283 st->len = GET_32BIT(st->pktin->data);
1284 st->pad = st->pktin->data[4];
1287 * _Completely_ silly lengths should be stomped on before they
1288 * do us any more damage.
1290 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1291 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
1292 bombout(("Incoming packet was garbled on decryption"));
1293 ssh_free_packet(st->pktin);
1298 * This enables us to deduce the payload length.
1300 st->payload = st->len - st->pad - 1;
1302 st->pktin->length = st->payload + 5;
1305 * So now we can work out the total packet length.
1307 st->packetlen = st->len + 4;
1308 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1311 * Allocate memory for the rest of the packet.
1313 st->pktin->maxlen = st->packetlen + st->maclen;
1314 st->pktin->data = sresize(st->pktin->data,
1315 st->pktin->maxlen + APIEXTRA,
1319 * Read and decrypt the remainder of the packet.
1321 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1323 while ((*datalen) == 0)
1325 st->pktin->data[st->i] = *(*data)++;
1328 /* Decrypt everything _except_ the MAC. */
1330 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1331 st->pktin->data + st->cipherblk,
1332 st->packetlen - st->cipherblk);
1334 st->pktin->encrypted_len = st->packetlen;
1340 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1341 st->incoming_sequence)) {
1342 bombout(("Incorrect MAC received on packet"));
1343 ssh_free_packet(st->pktin);
1347 st->pktin->sequence = st->incoming_sequence++;
1350 * Decompress packet payload.
1353 unsigned char *newpayload;
1356 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1357 st->pktin->data + 5, st->pktin->length - 5,
1358 &newpayload, &newlen)) {
1359 if (st->pktin->maxlen < newlen + 5) {
1360 st->pktin->maxlen = newlen + 5;
1361 st->pktin->data = sresize(st->pktin->data,
1362 st->pktin->maxlen + APIEXTRA,
1365 st->pktin->length = 5 + newlen;
1366 memcpy(st->pktin->data + 5, newpayload, newlen);
1371 st->pktin->savedpos = 6;
1372 st->pktin->body = st->pktin->data;
1373 st->pktin->type = st->pktin->data[5];
1376 * Log incoming packet, possibly omitting sensitive fields.
1380 struct logblank_t blank;
1381 if (ssh->cfg.logomitdata) {
1382 int do_blank = FALSE, blank_prefix = 0;
1383 /* "Session data" packets - omit the data field */
1384 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1385 do_blank = TRUE; blank_prefix = 4;
1386 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1387 do_blank = TRUE; blank_prefix = 8;
1390 blank.offset = blank_prefix;
1391 blank.len = (st->pktin->length-6) - blank_prefix;
1392 blank.type = PKTLOG_OMIT;
1396 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1397 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx,
1399 st->pktin->data+6, st->pktin->length-6,
1403 crFinish(st->pktin);
1406 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1408 int pad, biglen, i, pktoffs;
1412 * XXX various versions of SC (including 8.8.4) screw up the
1413 * register allocation in this function and use the same register
1414 * (D6) for len and as a temporary, with predictable results. The
1415 * following sledgehammer prevents this.
1422 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1423 ssh1_pkt_type(pkt->data[12]),
1424 pkt->body, pkt->length - (pkt->body - pkt->data),
1425 pkt->nblanks, pkt->blanks);
1426 sfree(pkt->blanks); pkt->blanks = NULL;
1429 if (ssh->v1_compressing) {
1430 unsigned char *compblk;
1432 zlib_compress_block(ssh->cs_comp_ctx,
1433 pkt->data + 12, pkt->length - 12,
1434 &compblk, &complen);
1435 ssh_pkt_ensure(pkt, complen + 2); /* just in case it's got bigger */
1436 memcpy(pkt->data + 12, compblk, complen);
1438 pkt->length = complen + 12;
1441 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1443 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1444 pad = 8 - (len % 8);
1446 biglen = len + pad; /* len(padding+type+data+CRC) */
1448 for (i = pktoffs; i < 4+8; i++)
1449 pkt->data[i] = random_byte();
1450 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1451 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1452 PUT_32BIT(pkt->data + pktoffs, len);
1455 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1456 pkt->data + pktoffs + 4, biglen);
1458 if (offset_p) *offset_p = pktoffs;
1459 return biglen + 4; /* len(length+padding+type+data+CRC) */
1462 static int s_write(Ssh ssh, void *data, int len)
1465 log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, 0, NULL);
1466 return sk_write(ssh->s, (char *)data, len);
1469 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1471 int len, backlog, offset;
1472 len = s_wrpkt_prepare(ssh, pkt, &offset);
1473 backlog = s_write(ssh, pkt->data + offset, len);
1474 if (backlog > SSH_MAX_BACKLOG)
1475 ssh_throttle_all(ssh, 1, backlog);
1476 ssh_free_packet(pkt);
1479 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1482 len = s_wrpkt_prepare(ssh, pkt, &offset);
1483 if (ssh->deferred_len + len > ssh->deferred_size) {
1484 ssh->deferred_size = ssh->deferred_len + len + 128;
1485 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1489 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1490 pkt->data + offset, len);
1491 ssh->deferred_len += len;
1492 ssh_free_packet(pkt);
1496 * Construct a SSH-1 packet with the specified contents.
1497 * (This all-at-once interface used to be the only one, but now SSH-1
1498 * packets can also be constructed incrementally.)
1500 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1506 pkt = ssh1_pkt_init(pkttype);
1508 while ((argtype = va_arg(ap, int)) != PKT_END) {
1509 unsigned char *argp, argchar;
1511 unsigned long argint;
1514 /* Actual fields in the packet */
1516 argint = va_arg(ap, int);
1517 ssh_pkt_adduint32(pkt, argint);
1520 argchar = (unsigned char) va_arg(ap, int);
1521 ssh_pkt_addbyte(pkt, argchar);
1524 argp = va_arg(ap, unsigned char *);
1525 arglen = va_arg(ap, int);
1526 ssh_pkt_adddata(pkt, argp, arglen);
1529 sargp = va_arg(ap, char *);
1530 ssh_pkt_addstring(pkt, sargp);
1533 bn = va_arg(ap, Bignum);
1534 ssh1_pkt_addmp(pkt, bn);
1536 /* Tokens for modifications to packet logging */
1538 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1541 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1544 end_log_omission(ssh, pkt);
1552 static void send_packet(Ssh ssh, int pkttype, ...)
1556 va_start(ap, pkttype);
1557 pkt = construct_packet(ssh, pkttype, ap);
1562 static void defer_packet(Ssh ssh, int pkttype, ...)
1566 va_start(ap, pkttype);
1567 pkt = construct_packet(ssh, pkttype, ap);
1569 s_wrpkt_defer(ssh, pkt);
1572 static int ssh_versioncmp(char *a, char *b)
1575 unsigned long av, bv;
1577 av = strtoul(a, &ae, 10);
1578 bv = strtoul(b, &be, 10);
1580 return (av < bv ? -1 : +1);
1585 av = strtoul(ae, &ae, 10);
1586 bv = strtoul(be, &be, 10);
1588 return (av < bv ? -1 : +1);
1593 * Utility routines for putting an SSH-protocol `string' and
1594 * `uint32' into a hash state.
1596 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1598 unsigned char lenblk[4];
1599 PUT_32BIT(lenblk, len);
1600 h->bytes(s, lenblk, 4);
1601 h->bytes(s, str, len);
1604 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1606 unsigned char intblk[4];
1607 PUT_32BIT(intblk, i);
1608 h->bytes(s, intblk, 4);
1612 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1614 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1616 if (pkt->maxlen < length) {
1617 unsigned char *body = pkt->body;
1618 int offset = body ? body - pkt->data : 0;
1619 pkt->maxlen = length + 256;
1620 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1621 if (body) pkt->body = pkt->data + offset;
1624 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1626 if (pkt->logmode != PKTLOG_EMIT) {
1628 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1630 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1631 (pkt->body - pkt->data);
1632 pkt->blanks[pkt->nblanks-1].len = len;
1633 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1636 ssh_pkt_ensure(pkt, pkt->length);
1637 memcpy(pkt->data + pkt->length - len, data, len);
1639 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1641 ssh_pkt_adddata(pkt, &byte, 1);
1643 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1645 ssh_pkt_adddata(pkt, &value, 1);
1647 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1650 PUT_32BIT(x, value);
1651 ssh_pkt_adddata(pkt, x, 4);
1653 static void ssh_pkt_addstring_start(struct Packet *pkt)
1655 ssh_pkt_adduint32(pkt, 0);
1656 pkt->savedpos = pkt->length;
1658 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1660 ssh_pkt_adddata(pkt, data, strlen(data));
1661 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1663 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1665 ssh_pkt_adddata(pkt, data, len);
1666 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1668 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1670 ssh_pkt_addstring_start(pkt);
1671 ssh_pkt_addstring_str(pkt, data);
1673 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1675 int len = ssh1_bignum_length(b);
1676 unsigned char *data = snewn(len, unsigned char);
1677 (void) ssh1_write_bignum(data, b);
1678 ssh_pkt_adddata(pkt, data, len);
1681 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1684 int i, n = (bignum_bitcount(b) + 7) / 8;
1685 p = snewn(n + 1, unsigned char);
1687 for (i = 1; i <= n; i++)
1688 p[i] = bignum_byte(b, n - i);
1690 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1692 memmove(p, p + i, n + 1 - i);
1696 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1700 p = ssh2_mpint_fmt(b, &len);
1701 ssh_pkt_addstring_start(pkt);
1702 ssh_pkt_addstring_data(pkt, (char *)p, len);
1706 static struct Packet *ssh1_pkt_init(int pkt_type)
1708 struct Packet *pkt = ssh_new_packet();
1709 pkt->length = 4 + 8; /* space for length + max padding */
1710 ssh_pkt_addbyte(pkt, pkt_type);
1711 pkt->body = pkt->data + pkt->length;
1715 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1716 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1717 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1718 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1719 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1720 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1721 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1722 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1723 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1725 static struct Packet *ssh2_pkt_init(int pkt_type)
1727 struct Packet *pkt = ssh_new_packet();
1728 pkt->length = 5; /* space for packet length + padding length */
1730 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1731 pkt->body = pkt->data + pkt->length; /* after packet type */
1736 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1737 * put the MAC on it. Final packet, ready to be sent, is stored in
1738 * pkt->data. Total length is returned.
1740 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1742 int cipherblk, maclen, padding, i;
1745 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1746 ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]),
1747 pkt->body, pkt->length - (pkt->body - pkt->data),
1748 pkt->nblanks, pkt->blanks);
1749 sfree(pkt->blanks); pkt->blanks = NULL;
1753 * Compress packet payload.
1756 unsigned char *newpayload;
1759 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1761 &newpayload, &newlen)) {
1763 ssh2_pkt_adddata(pkt, newpayload, newlen);
1769 * Add padding. At least four bytes, and must also bring total
1770 * length (minus MAC) up to a multiple of the block size.
1771 * If pkt->forcepad is set, make sure the packet is at least that size
1774 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1775 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1777 if (pkt->length + padding < pkt->forcepad)
1778 padding = pkt->forcepad - pkt->length;
1780 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1781 assert(padding <= 255);
1782 maclen = ssh->csmac ? ssh->csmac->len : 0;
1783 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1784 pkt->data[4] = padding;
1785 for (i = 0; i < padding; i++)
1786 pkt->data[pkt->length + i] = random_byte();
1787 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1789 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1790 pkt->length + padding,
1791 ssh->v2_outgoing_sequence);
1792 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1795 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1796 pkt->data, pkt->length + padding);
1798 pkt->encrypted_len = pkt->length + padding;
1800 /* Ready-to-send packet starts at pkt->data. We return length. */
1801 return pkt->length + padding + maclen;
1805 * Routines called from the main SSH code to send packets. There
1806 * are quite a few of these, because we have two separate
1807 * mechanisms for delaying the sending of packets:
1809 * - In order to send an IGNORE message and a password message in
1810 * a single fixed-length blob, we require the ability to
1811 * concatenate the encrypted forms of those two packets _into_ a
1812 * single blob and then pass it to our <network.h> transport
1813 * layer in one go. Hence, there's a deferment mechanism which
1814 * works after packet encryption.
1816 * - In order to avoid sending any connection-layer messages
1817 * during repeat key exchange, we have to queue up any such
1818 * outgoing messages _before_ they are encrypted (and in
1819 * particular before they're allocated sequence numbers), and
1820 * then send them once we've finished.
1822 * I call these mechanisms `defer' and `queue' respectively, so as
1823 * to distinguish them reasonably easily.
1825 * The functions send_noqueue() and defer_noqueue() free the packet
1826 * structure they are passed. Every outgoing packet goes through
1827 * precisely one of these functions in its life; packets passed to
1828 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1829 * these or get queued, and then when the queue is later emptied
1830 * the packets are all passed to defer_noqueue().
1832 * When using a CBC-mode cipher, it's necessary to ensure that an
1833 * attacker can't provide data to be encrypted using an IV that they
1834 * know. We ensure this by prefixing each packet that might contain
1835 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1836 * mechanism, so in this case send_noqueue() ends up redirecting to
1837 * defer_noqueue(). If you don't like this inefficiency, don't use
1841 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1842 static void ssh_pkt_defersend(Ssh);
1845 * Send an SSH-2 packet immediately, without queuing or deferring.
1847 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1851 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1852 /* We need to send two packets, so use the deferral mechanism. */
1853 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1854 ssh_pkt_defersend(ssh);
1857 len = ssh2_pkt_construct(ssh, pkt);
1858 backlog = s_write(ssh, pkt->data, len);
1859 if (backlog > SSH_MAX_BACKLOG)
1860 ssh_throttle_all(ssh, 1, backlog);
1862 ssh->outgoing_data_size += pkt->encrypted_len;
1863 if (!ssh->kex_in_progress &&
1864 ssh->max_data_size != 0 &&
1865 ssh->outgoing_data_size > ssh->max_data_size)
1866 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1868 ssh_free_packet(pkt);
1872 * Defer an SSH-2 packet.
1874 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1877 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1878 ssh->deferred_len == 0 && !noignore) {
1880 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1881 * get encrypted with a known IV.
1883 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1884 ssh2_pkt_addstring_start(ipkt);
1885 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1887 len = ssh2_pkt_construct(ssh, pkt);
1888 if (ssh->deferred_len + len > ssh->deferred_size) {
1889 ssh->deferred_size = ssh->deferred_len + len + 128;
1890 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1894 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1895 ssh->deferred_len += len;
1896 ssh->deferred_data_size += pkt->encrypted_len;
1897 ssh_free_packet(pkt);
1901 * Queue an SSH-2 packet.
1903 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1905 assert(ssh->queueing);
1907 if (ssh->queuelen >= ssh->queuesize) {
1908 ssh->queuesize = ssh->queuelen + 32;
1909 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1912 ssh->queue[ssh->queuelen++] = pkt;
1916 * Either queue or send a packet, depending on whether queueing is
1919 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1922 ssh2_pkt_queue(ssh, pkt);
1924 ssh2_pkt_send_noqueue(ssh, pkt);
1928 * Either queue or defer a packet, depending on whether queueing is
1931 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1934 ssh2_pkt_queue(ssh, pkt);
1936 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1940 * Send the whole deferred data block constructed by
1941 * ssh2_pkt_defer() or SSH-1's defer_packet().
1943 * The expected use of the defer mechanism is that you call
1944 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1945 * not currently queueing, this simply sets up deferred_send_data
1946 * and then sends it. If we _are_ currently queueing, the calls to
1947 * ssh2_pkt_defer() put the deferred packets on to the queue
1948 * instead, and therefore ssh_pkt_defersend() has no deferred data
1949 * to send. Hence, there's no need to make it conditional on
1952 static void ssh_pkt_defersend(Ssh ssh)
1955 backlog = s_write(ssh, ssh->deferred_send_data, ssh->deferred_len);
1956 ssh->deferred_len = ssh->deferred_size = 0;
1957 sfree(ssh->deferred_send_data);
1958 ssh->deferred_send_data = NULL;
1959 if (backlog > SSH_MAX_BACKLOG)
1960 ssh_throttle_all(ssh, 1, backlog);
1962 ssh->outgoing_data_size += ssh->deferred_data_size;
1963 if (!ssh->kex_in_progress &&
1964 ssh->max_data_size != 0 &&
1965 ssh->outgoing_data_size > ssh->max_data_size)
1966 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1967 ssh->deferred_data_size = 0;
1971 * Send a packet whose length needs to be disguised (typically
1972 * passwords or keyboard-interactive responses).
1974 static void ssh2_pkt_send_with_padding(Ssh ssh, struct Packet *pkt,
1980 * The simplest way to do this is to adjust the
1981 * variable-length padding field in the outgoing packet.
1983 * Currently compiled out, because some Cisco SSH servers
1984 * don't like excessively padded packets (bah, why's it
1987 pkt->forcepad = padsize;
1988 ssh2_pkt_send(ssh, pkt);
1993 * If we can't do that, however, an alternative approach is
1994 * to use the pkt_defer mechanism to bundle the packet
1995 * tightly together with an SSH_MSG_IGNORE such that their
1996 * combined length is a constant. So first we construct the
1997 * final form of this packet and defer its sending.
1999 ssh2_pkt_defer(ssh, pkt);
2002 * Now construct an SSH_MSG_IGNORE which includes a string
2003 * that's an exact multiple of the cipher block size. (If
2004 * the cipher is NULL so that the block size is
2005 * unavailable, we don't do this trick at all, because we
2006 * gain nothing by it.)
2008 if (ssh->cscipher) {
2011 stringlen = (256 - ssh->deferred_len);
2012 stringlen += ssh->cscipher->blksize - 1;
2013 stringlen -= (stringlen % ssh->cscipher->blksize);
2016 * Temporarily disable actual compression, so we
2017 * can guarantee to get this string exactly the
2018 * length we want it. The compression-disabling
2019 * routine should return an integer indicating how
2020 * many bytes we should adjust our string length
2024 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
2026 pkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
2027 ssh2_pkt_addstring_start(pkt);
2028 for (i = 0; i < stringlen; i++) {
2029 char c = (char) random_byte();
2030 ssh2_pkt_addstring_data(pkt, &c, 1);
2032 ssh2_pkt_defer(ssh, pkt);
2034 ssh_pkt_defersend(ssh);
2039 * Send all queued SSH-2 packets. We send them by means of
2040 * ssh2_pkt_defer_noqueue(), in case they included a pair of
2041 * packets that needed to be lumped together.
2043 static void ssh2_pkt_queuesend(Ssh ssh)
2047 assert(!ssh->queueing);
2049 for (i = 0; i < ssh->queuelen; i++)
2050 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
2053 ssh_pkt_defersend(ssh);
2057 void bndebug(char *string, Bignum b)
2061 p = ssh2_mpint_fmt(b, &len);
2062 debug(("%s", string));
2063 for (i = 0; i < len; i++)
2064 debug((" %02x", p[i]));
2070 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
2074 p = ssh2_mpint_fmt(b, &len);
2075 hash_string(h, s, p, len);
2080 * Packet decode functions for both SSH-1 and SSH-2.
2082 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
2084 unsigned long value;
2085 if (pkt->length - pkt->savedpos < 4)
2086 return 0; /* arrgh, no way to decline (FIXME?) */
2087 value = GET_32BIT(pkt->body + pkt->savedpos);
2091 static int ssh2_pkt_getbool(struct Packet *pkt)
2093 unsigned long value;
2094 if (pkt->length - pkt->savedpos < 1)
2095 return 0; /* arrgh, no way to decline (FIXME?) */
2096 value = pkt->body[pkt->savedpos] != 0;
2100 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2105 if (pkt->length - pkt->savedpos < 4)
2107 len = GET_32BIT(pkt->body + pkt->savedpos);
2112 if (pkt->length - pkt->savedpos < *length)
2114 *p = (char *)(pkt->body + pkt->savedpos);
2115 pkt->savedpos += *length;
2117 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2119 if (pkt->length - pkt->savedpos < length)
2121 pkt->savedpos += length;
2122 return pkt->body + (pkt->savedpos - length);
2124 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2125 unsigned char **keystr)
2129 j = makekey(pkt->body + pkt->savedpos,
2130 pkt->length - pkt->savedpos,
2137 assert(pkt->savedpos < pkt->length);
2141 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2146 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2147 pkt->length - pkt->savedpos, &b);
2155 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2161 ssh_pkt_getstring(pkt, &p, &length);
2166 b = bignum_from_bytes((unsigned char *)p, length);
2171 * Helper function to add an SSH-2 signature blob to a packet.
2172 * Expects to be shown the public key blob as well as the signature
2173 * blob. Normally works just like ssh2_pkt_addstring, but will
2174 * fiddle with the signature packet if necessary for
2175 * BUG_SSH2_RSA_PADDING.
2177 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2178 void *pkblob_v, int pkblob_len,
2179 void *sigblob_v, int sigblob_len)
2181 unsigned char *pkblob = (unsigned char *)pkblob_v;
2182 unsigned char *sigblob = (unsigned char *)sigblob_v;
2184 /* dmemdump(pkblob, pkblob_len); */
2185 /* dmemdump(sigblob, sigblob_len); */
2188 * See if this is in fact an ssh-rsa signature and a buggy
2189 * server; otherwise we can just do this the easy way.
2191 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2192 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2193 int pos, len, siglen;
2196 * Find the byte length of the modulus.
2199 pos = 4+7; /* skip over "ssh-rsa" */
2200 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2201 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2202 pos += 4; /* find modulus itself */
2203 while (len > 0 && pkblob[pos] == 0)
2205 /* debug(("modulus length is %d\n", len)); */
2208 * Now find the signature integer.
2210 pos = 4+7; /* skip over "ssh-rsa" */
2211 siglen = GET_32BIT(sigblob+pos);
2212 /* debug(("signature length is %d\n", siglen)); */
2214 if (len != siglen) {
2215 unsigned char newlen[4];
2216 ssh2_pkt_addstring_start(pkt);
2217 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2218 /* dmemdump(sigblob, pos); */
2219 pos += 4; /* point to start of actual sig */
2220 PUT_32BIT(newlen, len);
2221 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2222 /* dmemdump(newlen, 4); */
2224 while (len-- > siglen) {
2225 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2226 /* dmemdump(newlen, 1); */
2228 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2229 /* dmemdump(sigblob+pos, siglen); */
2233 /* Otherwise fall through and do it the easy way. */
2236 ssh2_pkt_addstring_start(pkt);
2237 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2241 * Examine the remote side's version string and compare it against
2242 * a list of known buggy implementations.
2244 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2246 char *imp; /* pointer to implementation part */
2248 imp += strcspn(imp, "-");
2250 imp += strcspn(imp, "-");
2253 ssh->remote_bugs = 0;
2256 * General notes on server version strings:
2257 * - Not all servers reporting "Cisco-1.25" have all the bugs listed
2258 * here -- in particular, we've heard of one that's perfectly happy
2259 * with SSH1_MSG_IGNOREs -- but this string never seems to change,
2260 * so we can't distinguish them.
2262 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2263 (ssh->cfg.sshbug_ignore1 == AUTO &&
2264 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2265 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2266 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2267 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2269 * These versions don't support SSH1_MSG_IGNORE, so we have
2270 * to use a different defence against password length
2273 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2274 logevent("We believe remote version has SSH-1 ignore bug");
2277 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2278 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2279 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2281 * These versions need a plain password sent; they can't
2282 * handle having a null and a random length of data after
2285 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2286 logevent("We believe remote version needs a plain SSH-1 password");
2289 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2290 (ssh->cfg.sshbug_rsa1 == AUTO &&
2291 (!strcmp(imp, "Cisco-1.25")))) {
2293 * These versions apparently have no clue whatever about
2294 * RSA authentication and will panic and die if they see
2295 * an AUTH_RSA message.
2297 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2298 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2301 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2302 (ssh->cfg.sshbug_hmac2 == AUTO &&
2303 !wc_match("* VShell", imp) &&
2304 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2305 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2306 wc_match("2.1 *", imp)))) {
2308 * These versions have the HMAC bug.
2310 ssh->remote_bugs |= BUG_SSH2_HMAC;
2311 logevent("We believe remote version has SSH-2 HMAC bug");
2314 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2315 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2316 !wc_match("* VShell", imp) &&
2317 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2319 * These versions have the key-derivation bug (failing to
2320 * include the literal shared secret in the hashes that
2321 * generate the keys).
2323 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2324 logevent("We believe remote version has SSH-2 key-derivation bug");
2327 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2328 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2329 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2330 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2332 * These versions have the SSH-2 RSA padding bug.
2334 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2335 logevent("We believe remote version has SSH-2 RSA padding bug");
2338 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2339 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2340 wc_match("OpenSSH_2.[0-2]*", imp))) {
2342 * These versions have the SSH-2 session-ID bug in
2343 * public-key authentication.
2345 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2346 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2349 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2350 (ssh->cfg.sshbug_rekey2 == AUTO &&
2351 (wc_match("DigiSSH_2.0", imp) ||
2352 wc_match("OpenSSH_2.[0-4]*", imp) ||
2353 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2354 wc_match("Sun_SSH_1.0", imp) ||
2355 wc_match("Sun_SSH_1.0.1", imp) ||
2356 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2357 wc_match("WeOnlyDo-*", imp)))) {
2359 * These versions have the SSH-2 rekey bug.
2361 ssh->remote_bugs |= BUG_SSH2_REKEY;
2362 logevent("We believe remote version has SSH-2 rekey bug");
2367 * The `software version' part of an SSH version string is required
2368 * to contain no spaces or minus signs.
2370 static void ssh_fix_verstring(char *str)
2372 /* Eat "SSH-<protoversion>-". */
2373 assert(*str == 'S'); str++;
2374 assert(*str == 'S'); str++;
2375 assert(*str == 'H'); str++;
2376 assert(*str == '-'); str++;
2377 while (*str && *str != '-') str++;
2378 assert(*str == '-'); str++;
2380 /* Convert minus signs and spaces in the remaining string into
2383 if (*str == '-' || *str == ' ')
2390 * Send an appropriate SSH version string.
2392 static void ssh_send_verstring(Ssh ssh, char *svers)
2396 if (ssh->version == 2) {
2398 * Construct a v2 version string.
2400 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2403 * Construct a v1 version string.
2405 verstring = dupprintf("SSH-%s-%s\012",
2406 (ssh_versioncmp(svers, "1.5") <= 0 ?
2411 ssh_fix_verstring(verstring);
2413 if (ssh->version == 2) {
2416 * Record our version string.
2418 len = strcspn(verstring, "\015\012");
2419 ssh->v_c = snewn(len + 1, char);
2420 memcpy(ssh->v_c, verstring, len);
2424 logeventf(ssh, "We claim version: %.*s",
2425 strcspn(verstring, "\015\012"), verstring);
2426 s_write(ssh, verstring, strlen(verstring));
2430 static int do_ssh_init(Ssh ssh, unsigned char c)
2432 struct do_ssh_init_state {
2440 crState(do_ssh_init_state);
2442 crBegin(ssh->do_ssh_init_crstate);
2444 /* Search for a line beginning with the string "SSH-" in the input. */
2446 if (c != 'S') goto no;
2448 if (c != 'S') goto no;
2450 if (c != 'H') goto no;
2452 if (c != '-') goto no;
2461 s->vstring = snewn(s->vstrsize, char);
2462 strcpy(s->vstring, "SSH-");
2466 crReturn(1); /* get another char */
2467 if (s->vslen >= s->vstrsize - 1) {
2469 s->vstring = sresize(s->vstring, s->vstrsize, char);
2471 s->vstring[s->vslen++] = c;
2474 s->version[s->i] = '\0';
2476 } else if (s->i < sizeof(s->version) - 1)
2477 s->version[s->i++] = c;
2478 } else if (c == '\012')
2482 ssh->agentfwd_enabled = FALSE;
2483 ssh->rdpkt2_state.incoming_sequence = 0;
2485 s->vstring[s->vslen] = 0;
2486 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2487 logeventf(ssh, "Server version: %s", s->vstring);
2488 ssh_detect_bugs(ssh, s->vstring);
2491 * Decide which SSH protocol version to support.
2494 /* Anything strictly below "2.0" means protocol 1 is supported. */
2495 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2496 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2497 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2499 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2500 bombout(("SSH protocol version 1 required by user but not provided by server"));
2503 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2504 bombout(("SSH protocol version 2 required by user but not provided by server"));
2508 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1))
2513 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2515 /* Send the version string, if we haven't already */
2516 if (ssh->cfg.sshprot != 3)
2517 ssh_send_verstring(ssh, s->version);
2519 if (ssh->version == 2) {
2522 * Record their version string.
2524 len = strcspn(s->vstring, "\015\012");
2525 ssh->v_s = snewn(len + 1, char);
2526 memcpy(ssh->v_s, s->vstring, len);
2530 * Initialise SSH-2 protocol.
2532 ssh->protocol = ssh2_protocol;
2533 ssh2_protocol_setup(ssh);
2534 ssh->s_rdpkt = ssh2_rdpkt;
2537 * Initialise SSH-1 protocol.
2539 ssh->protocol = ssh1_protocol;
2540 ssh1_protocol_setup(ssh);
2541 ssh->s_rdpkt = ssh1_rdpkt;
2543 if (ssh->version == 2)
2544 do_ssh2_transport(ssh, NULL, -1, NULL);
2546 update_specials_menu(ssh->frontend);
2547 ssh->state = SSH_STATE_BEFORE_SIZE;
2548 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2555 static void ssh_process_incoming_data(Ssh ssh,
2556 unsigned char **data, int *datalen)
2558 struct Packet *pktin;
2560 pktin = ssh->s_rdpkt(ssh, data, datalen);
2562 ssh->protocol(ssh, NULL, 0, pktin);
2563 ssh_free_packet(pktin);
2567 static void ssh_queue_incoming_data(Ssh ssh,
2568 unsigned char **data, int *datalen)
2570 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2575 static void ssh_process_queued_incoming_data(Ssh ssh)
2578 unsigned char *data;
2581 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2582 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2586 while (!ssh->frozen && len > 0)
2587 ssh_process_incoming_data(ssh, &data, &len);
2590 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2594 static void ssh_set_frozen(Ssh ssh, int frozen)
2597 sk_set_frozen(ssh->s, frozen);
2598 ssh->frozen = frozen;
2601 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2603 /* Log raw data, if we're in that mode. */
2605 log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen,
2608 crBegin(ssh->ssh_gotdata_crstate);
2611 * To begin with, feed the characters one by one to the
2612 * protocol initialisation / selection function do_ssh_init().
2613 * When that returns 0, we're done with the initial greeting
2614 * exchange and can move on to packet discipline.
2617 int ret; /* need not be kept across crReturn */
2619 crReturnV; /* more data please */
2620 ret = do_ssh_init(ssh, *data);
2628 * We emerge from that loop when the initial negotiation is
2629 * over and we have selected an s_rdpkt function. Now pass
2630 * everything to s_rdpkt, and then pass the resulting packets
2631 * to the proper protocol handler.
2635 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2637 ssh_queue_incoming_data(ssh, &data, &datalen);
2638 /* This uses up all data and cannot cause anything interesting
2639 * to happen; indeed, for anything to happen at all, we must
2640 * return, so break out. */
2642 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2643 /* This uses up some or all data, and may freeze the
2645 ssh_process_queued_incoming_data(ssh);
2647 /* This uses up some or all data, and may freeze the
2649 ssh_process_incoming_data(ssh, &data, &datalen);
2651 /* FIXME this is probably EBW. */
2652 if (ssh->state == SSH_STATE_CLOSED)
2655 /* We're out of data. Go and get some more. */
2661 static int ssh_do_close(Ssh ssh, int notify_exit)
2664 struct ssh_channel *c;
2666 ssh->state = SSH_STATE_CLOSED;
2667 expire_timer_context(ssh);
2672 notify_remote_exit(ssh->frontend);
2677 * Now we must shut down any port- and X-forwarded channels going
2678 * through this connection.
2680 if (ssh->channels) {
2681 while (NULL != (c = index234(ssh->channels, 0))) {
2684 x11_close(c->u.x11.s);
2687 pfd_close(c->u.pfd.s);
2690 del234(ssh->channels, c); /* moving next one to index 0 */
2691 if (ssh->version == 2)
2692 bufchain_clear(&c->v.v2.outbuffer);
2697 * Go through port-forwardings, and close any associated
2698 * listening sockets.
2700 if (ssh->portfwds) {
2701 struct ssh_portfwd *pf;
2702 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2703 /* Dispose of any listening socket. */
2705 pfd_terminate(pf->local);
2706 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2714 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2715 const char *error_msg, int error_code)
2717 Ssh ssh = (Ssh) plug;
2718 char addrbuf[256], *msg;
2720 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2723 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2725 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2731 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2734 Ssh ssh = (Ssh) plug;
2735 int need_notify = ssh_do_close(ssh, FALSE);
2738 if (!ssh->close_expected)
2739 error_msg = "Server unexpectedly closed network connection";
2741 error_msg = "Server closed network connection";
2744 if (ssh->close_expected && ssh->clean_exit && ssh->exitcode < 0)
2748 notify_remote_exit(ssh->frontend);
2751 logevent(error_msg);
2752 if (!ssh->close_expected || !ssh->clean_exit)
2753 connection_fatal(ssh->frontend, "%s", error_msg);
2757 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2759 Ssh ssh = (Ssh) plug;
2760 ssh_gotdata(ssh, (unsigned char *)data, len);
2761 if (ssh->state == SSH_STATE_CLOSED) {
2762 ssh_do_close(ssh, TRUE);
2768 static void ssh_sent(Plug plug, int bufsize)
2770 Ssh ssh = (Ssh) plug;
2772 * If the send backlog on the SSH socket itself clears, we
2773 * should unthrottle the whole world if it was throttled.
2775 if (bufsize < SSH_MAX_BACKLOG)
2776 ssh_throttle_all(ssh, 0, bufsize);
2780 * Connect to specified host and port.
2781 * Returns an error message, or NULL on success.
2782 * Also places the canonical host name into `realhost'. It must be
2783 * freed by the caller.
2785 static const char *connect_to_host(Ssh ssh, char *host, int port,
2786 char **realhost, int nodelay, int keepalive)
2788 static const struct plug_function_table fn_table = {
2799 ssh->savedhost = snewn(1 + strlen(host), char);
2800 strcpy(ssh->savedhost, host);
2803 port = 22; /* default ssh port */
2804 ssh->savedport = port;
2809 logeventf(ssh, "Looking up host \"%s\"%s", host,
2810 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2811 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2812 addr = name_lookup(host, port, realhost, &ssh->cfg,
2813 ssh->cfg.addressfamily);
2814 if ((err = sk_addr_error(addr)) != NULL) {
2822 ssh->fn = &fn_table;
2823 ssh->s = new_connection(addr, *realhost, port,
2824 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2825 if ((err = sk_socket_error(ssh->s)) != NULL) {
2827 notify_remote_exit(ssh->frontend);
2832 * If the SSH version number's fixed, set it now, and if it's SSH-2,
2833 * send the version string too.
2835 if (ssh->cfg.sshprot == 0)
2837 if (ssh->cfg.sshprot == 3) {
2839 ssh_send_verstring(ssh, NULL);
2846 * Throttle or unthrottle the SSH connection.
2848 static void ssh1_throttle(Ssh ssh, int adjust)
2850 int old_count = ssh->v1_throttle_count;
2851 ssh->v1_throttle_count += adjust;
2852 assert(ssh->v1_throttle_count >= 0);
2853 if (ssh->v1_throttle_count && !old_count) {
2854 ssh_set_frozen(ssh, 1);
2855 } else if (!ssh->v1_throttle_count && old_count) {
2856 ssh_set_frozen(ssh, 0);
2861 * Throttle or unthrottle _all_ local data streams (for when sends
2862 * on the SSH connection itself back up).
2864 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2867 struct ssh_channel *c;
2869 if (enable == ssh->throttled_all)
2871 ssh->throttled_all = enable;
2872 ssh->overall_bufsize = bufsize;
2875 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2877 case CHAN_MAINSESSION:
2879 * This is treated separately, outside the switch.
2883 x11_override_throttle(c->u.x11.s, enable);
2886 /* Agent channels require no buffer management. */
2889 pfd_override_throttle(c->u.pfd.s, enable);
2895 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2897 Ssh ssh = (Ssh) sshv;
2899 ssh->agent_response = reply;
2900 ssh->agent_response_len = replylen;
2902 if (ssh->version == 1)
2903 do_ssh1_login(ssh, NULL, -1, NULL);
2905 do_ssh2_authconn(ssh, NULL, -1, NULL);
2908 static void ssh_dialog_callback(void *sshv, int ret)
2910 Ssh ssh = (Ssh) sshv;
2912 ssh->user_response = ret;
2914 if (ssh->version == 1)
2915 do_ssh1_login(ssh, NULL, -1, NULL);
2917 do_ssh2_transport(ssh, NULL, -1, NULL);
2920 * This may have unfrozen the SSH connection, so do a
2923 ssh_process_queued_incoming_data(ssh);
2926 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2928 struct ssh_channel *c = (struct ssh_channel *)cv;
2930 void *sentreply = reply;
2933 /* Fake SSH_AGENT_FAILURE. */
2934 sentreply = "\0\0\0\1\5";
2937 if (ssh->version == 2) {
2938 ssh2_add_channel_data(c, sentreply, replylen);
2941 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2942 PKT_INT, c->remoteid,
2945 PKT_DATA, sentreply, replylen,
2954 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2955 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2956 * => log `wire_reason'.
2958 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2959 int code, int clean_exit)
2963 client_reason = wire_reason;
2965 error = dupprintf("Disconnected: %s", client_reason);
2967 error = dupstr("Disconnected");
2969 if (ssh->version == 1) {
2970 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2972 } else if (ssh->version == 2) {
2973 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2974 ssh2_pkt_adduint32(pktout, code);
2975 ssh2_pkt_addstring(pktout, wire_reason);
2976 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2977 ssh2_pkt_send_noqueue(ssh, pktout);
2980 ssh->close_expected = TRUE;
2981 ssh->clean_exit = clean_exit;
2982 ssh_closing((Plug)ssh, error, 0, 0);
2987 * Handle the key exchange and user authentication phases.
2989 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2990 struct Packet *pktin)
2993 unsigned char cookie[8], *ptr;
2994 struct RSAKey servkey, hostkey;
2995 struct MD5Context md5c;
2996 struct do_ssh1_login_state {
2998 unsigned char *rsabuf, *keystr1, *keystr2;
2999 unsigned long supported_ciphers_mask, supported_auths_mask;
3000 int tried_publickey, tried_agent;
3001 int tis_auth_refused, ccard_auth_refused;
3002 unsigned char session_id[16];
3005 void *publickey_blob;
3006 int publickey_bloblen;
3007 char *publickey_comment;
3008 int publickey_encrypted;
3009 prompts_t *cur_prompt;
3012 unsigned char request[5], *response, *p;
3022 crState(do_ssh1_login_state);
3024 crBegin(ssh->do_ssh1_login_crstate);
3029 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
3030 bombout(("Public key packet not received"));
3034 logevent("Received public keys");
3036 ptr = ssh_pkt_getdata(pktin, 8);
3038 bombout(("SSH-1 public key packet stopped before random cookie"));
3041 memcpy(cookie, ptr, 8);
3043 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
3044 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
3045 bombout(("Failed to read SSH-1 public keys from public key packet"));
3050 * Log the host key fingerprint.
3054 logevent("Host key fingerprint is:");
3055 strcpy(logmsg, " ");
3056 hostkey.comment = NULL;
3057 rsa_fingerprint(logmsg + strlen(logmsg),
3058 sizeof(logmsg) - strlen(logmsg), &hostkey);
3062 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
3063 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
3064 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
3066 ssh->v1_local_protoflags =
3067 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
3068 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3071 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3072 MD5Update(&md5c, s->keystr1, servkey.bytes);
3073 MD5Update(&md5c, cookie, 8);
3074 MD5Final(s->session_id, &md5c);
3076 for (i = 0; i < 32; i++)
3077 ssh->session_key[i] = random_byte();
3080 * Verify that the `bits' and `bytes' parameters match.
3082 if (hostkey.bits > hostkey.bytes * 8 ||
3083 servkey.bits > servkey.bytes * 8) {
3084 bombout(("SSH-1 public keys were badly formatted"));
3088 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3090 s->rsabuf = snewn(s->len, unsigned char);
3093 * Verify the host key.
3097 * First format the key into a string.
3099 int len = rsastr_len(&hostkey);
3100 char fingerprint[100];
3101 char *keystr = snewn(len, char);
3102 rsastr_fmt(keystr, &hostkey);
3103 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3105 ssh_set_frozen(ssh, 1);
3106 s->dlgret = verify_ssh_host_key(ssh->frontend,
3107 ssh->savedhost, ssh->savedport,
3108 "rsa", keystr, fingerprint,
3109 ssh_dialog_callback, ssh);
3111 if (s->dlgret < 0) {
3115 bombout(("Unexpected data from server while waiting"
3116 " for user host key response"));
3119 } while (pktin || inlen > 0);
3120 s->dlgret = ssh->user_response;
3122 ssh_set_frozen(ssh, 0);
3124 if (s->dlgret == 0) {
3125 ssh_disconnect(ssh, "User aborted at host key verification",
3131 for (i = 0; i < 32; i++) {
3132 s->rsabuf[i] = ssh->session_key[i];
3134 s->rsabuf[i] ^= s->session_id[i];
3137 if (hostkey.bytes > servkey.bytes) {
3138 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3140 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3142 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3144 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3147 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3151 logevent("Encrypted session key");
3154 int cipher_chosen = 0, warn = 0;
3155 char *cipher_string = NULL;
3157 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3158 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3159 if (next_cipher == CIPHER_WARN) {
3160 /* If/when we choose a cipher, warn about it */
3162 } else if (next_cipher == CIPHER_AES) {
3163 /* XXX Probably don't need to mention this. */
3164 logevent("AES not supported in SSH-1, skipping");
3166 switch (next_cipher) {
3167 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3168 cipher_string = "3DES"; break;
3169 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3170 cipher_string = "Blowfish"; break;
3171 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3172 cipher_string = "single-DES"; break;
3174 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3178 if (!cipher_chosen) {
3179 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3180 bombout(("Server violates SSH-1 protocol by not "
3181 "supporting 3DES encryption"));
3183 /* shouldn't happen */
3184 bombout(("No supported ciphers found"));
3188 /* Warn about chosen cipher if necessary. */
3190 ssh_set_frozen(ssh, 1);
3191 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3192 ssh_dialog_callback, ssh);
3193 if (s->dlgret < 0) {
3197 bombout(("Unexpected data from server while waiting"
3198 " for user response"));
3201 } while (pktin || inlen > 0);
3202 s->dlgret = ssh->user_response;
3204 ssh_set_frozen(ssh, 0);
3205 if (s->dlgret == 0) {
3206 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3213 switch (s->cipher_type) {
3214 case SSH_CIPHER_3DES:
3215 logevent("Using 3DES encryption");
3217 case SSH_CIPHER_DES:
3218 logevent("Using single-DES encryption");
3220 case SSH_CIPHER_BLOWFISH:
3221 logevent("Using Blowfish encryption");
3225 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3226 PKT_CHAR, s->cipher_type,
3227 PKT_DATA, cookie, 8,
3228 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3229 PKT_DATA, s->rsabuf, s->len,
3230 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3232 logevent("Trying to enable encryption...");
3236 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3237 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3239 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3240 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3241 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3243 ssh->crcda_ctx = crcda_make_context();
3244 logevent("Installing CRC compensation attack detector");
3246 if (servkey.modulus) {
3247 sfree(servkey.modulus);
3248 servkey.modulus = NULL;
3250 if (servkey.exponent) {
3251 sfree(servkey.exponent);
3252 servkey.exponent = NULL;
3254 if (hostkey.modulus) {
3255 sfree(hostkey.modulus);
3256 hostkey.modulus = NULL;
3258 if (hostkey.exponent) {
3259 sfree(hostkey.exponent);
3260 hostkey.exponent = NULL;
3264 if (pktin->type != SSH1_SMSG_SUCCESS) {
3265 bombout(("Encryption not successfully enabled"));
3269 logevent("Successfully started encryption");
3271 fflush(stdout); /* FIXME eh? */
3273 if (!*ssh->cfg.username) {
3274 int ret; /* need not be kept over crReturn */
3275 s->cur_prompt = new_prompts(ssh->frontend);
3276 s->cur_prompt->to_server = TRUE;
3277 s->cur_prompt->name = dupstr("SSH login name");
3278 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
3279 lenof(s->username));
3280 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3283 crWaitUntil(!pktin);
3284 ret = get_userpass_input(s->cur_prompt, in, inlen);
3289 * Failed to get a username. Terminate.
3291 free_prompts(s->cur_prompt);
3292 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3295 memcpy(s->username, s->cur_prompt->prompts[0]->result,
3296 lenof(s->username));
3297 free_prompts(s->cur_prompt);
3299 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3300 s->username[sizeof(s->username)-1] = '\0';
3303 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3305 char *userlog = dupprintf("Sent username \"%s\"", s->username);
3307 if (flags & FLAG_INTERACTIVE &&
3308 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3309 c_write_str(ssh, userlog);
3310 c_write_str(ssh, "\r\n");
3318 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3319 /* We must not attempt PK auth. Pretend we've already tried it. */
3320 s->tried_publickey = s->tried_agent = 1;
3322 s->tried_publickey = s->tried_agent = 0;
3324 s->tis_auth_refused = s->ccard_auth_refused = 0;
3326 * Load the public half of any configured keyfile for later use.
3328 if (!filename_is_null(ssh->cfg.keyfile)) {
3330 logeventf(ssh, "Reading private key file \"%.150s\"",
3331 filename_to_str(&ssh->cfg.keyfile));
3332 keytype = key_type(&ssh->cfg.keyfile);
3333 if (keytype == SSH_KEYTYPE_SSH1) {
3335 if (rsakey_pubblob(&ssh->cfg.keyfile,
3336 &s->publickey_blob, &s->publickey_bloblen,
3337 &s->publickey_comment, &error)) {
3338 s->publickey_encrypted = rsakey_encrypted(&ssh->cfg.keyfile,
3342 logeventf(ssh, "Unable to load private key (%s)", error);
3343 msgbuf = dupprintf("Unable to load private key file "
3344 "\"%.150s\" (%s)\r\n",
3345 filename_to_str(&ssh->cfg.keyfile),
3347 c_write_str(ssh, msgbuf);
3349 s->publickey_blob = NULL;
3353 logeventf(ssh, "Unable to use this key file (%s)",
3354 key_type_to_str(keytype));
3355 msgbuf = dupprintf("Unable to use key file \"%.150s\""
3357 filename_to_str(&ssh->cfg.keyfile),
3358 key_type_to_str(keytype));
3359 c_write_str(ssh, msgbuf);
3361 s->publickey_blob = NULL;
3364 s->publickey_blob = NULL;
3366 while (pktin->type == SSH1_SMSG_FAILURE) {
3367 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3369 if (ssh->cfg.tryagent && agent_exists() && !s->tried_agent) {
3371 * Attempt RSA authentication using Pageant.
3377 logevent("Pageant is running. Requesting keys.");
3379 /* Request the keys held by the agent. */
3380 PUT_32BIT(s->request, 1);
3381 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3382 if (!agent_query(s->request, 5, &r, &s->responselen,
3383 ssh_agent_callback, ssh)) {
3387 bombout(("Unexpected data from server while waiting"
3388 " for agent response"));
3391 } while (pktin || inlen > 0);
3392 r = ssh->agent_response;
3393 s->responselen = ssh->agent_response_len;
3395 s->response = (unsigned char *) r;
3396 if (s->response && s->responselen >= 5 &&
3397 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3398 s->p = s->response + 5;
3399 s->nkeys = GET_32BIT(s->p);
3401 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3402 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3403 unsigned char *pkblob = s->p;
3407 do { /* do while (0) to make breaking easy */
3408 n = ssh1_read_bignum
3409 (s->p, s->responselen-(s->p-s->response),
3414 n = ssh1_read_bignum
3415 (s->p, s->responselen-(s->p-s->response),
3420 if (s->responselen - (s->p-s->response) < 4)
3422 s->commentlen = GET_32BIT(s->p);
3424 if (s->responselen - (s->p-s->response) <
3427 s->commentp = (char *)s->p;
3428 s->p += s->commentlen;
3432 logevent("Pageant key list packet was truncated");
3436 if (s->publickey_blob) {
3437 if (!memcmp(pkblob, s->publickey_blob,
3438 s->publickey_bloblen)) {
3439 logeventf(ssh, "Pageant key #%d matches "
3440 "configured key file", s->keyi);
3441 s->tried_publickey = 1;
3443 /* Skip non-configured key */
3446 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3447 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3448 PKT_BIGNUM, s->key.modulus, PKT_END);
3450 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3451 logevent("Key refused");
3454 logevent("Received RSA challenge");
3455 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3456 bombout(("Server's RSA challenge was badly formatted"));
3461 char *agentreq, *q, *ret;
3464 len = 1 + 4; /* message type, bit count */
3465 len += ssh1_bignum_length(s->key.exponent);
3466 len += ssh1_bignum_length(s->key.modulus);
3467 len += ssh1_bignum_length(s->challenge);
3468 len += 16; /* session id */
3469 len += 4; /* response format */
3470 agentreq = snewn(4 + len, char);
3471 PUT_32BIT(agentreq, len);
3473 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3474 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3476 q += ssh1_write_bignum(q, s->key.exponent);
3477 q += ssh1_write_bignum(q, s->key.modulus);
3478 q += ssh1_write_bignum(q, s->challenge);
3479 memcpy(q, s->session_id, 16);
3481 PUT_32BIT(q, 1); /* response format */
3482 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3483 ssh_agent_callback, ssh)) {
3488 bombout(("Unexpected data from server"
3489 " while waiting for agent"
3493 } while (pktin || inlen > 0);
3494 vret = ssh->agent_response;
3495 retlen = ssh->agent_response_len;
3500 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3501 logevent("Sending Pageant's response");
3502 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3503 PKT_DATA, ret + 5, 16,
3507 if (pktin->type == SSH1_SMSG_SUCCESS) {
3509 ("Pageant's response accepted");
3510 if (flags & FLAG_VERBOSE) {
3511 c_write_str(ssh, "Authenticated using"
3513 c_write(ssh, s->commentp,
3515 c_write_str(ssh, "\" from agent\r\n");
3520 ("Pageant's response not accepted");
3523 ("Pageant failed to answer challenge");
3527 logevent("No reply received from Pageant");
3530 freebn(s->key.exponent);
3531 freebn(s->key.modulus);
3532 freebn(s->challenge);
3537 if (s->publickey_blob && !s->tried_publickey)
3538 logevent("Configured key file not in Pageant");
3543 if (s->publickey_blob && !s->tried_publickey) {
3545 * Try public key authentication with the specified
3548 int got_passphrase; /* need not be kept over crReturn */
3549 if (flags & FLAG_VERBOSE)
3550 c_write_str(ssh, "Trying public key authentication.\r\n");
3551 logeventf(ssh, "Trying public key \"%s\"",
3552 filename_to_str(&ssh->cfg.keyfile));
3553 s->tried_publickey = 1;
3554 got_passphrase = FALSE;
3555 while (!got_passphrase) {
3557 * Get a passphrase, if necessary.
3559 char *passphrase = NULL; /* only written after crReturn */
3561 if (!s->publickey_encrypted) {
3562 if (flags & FLAG_VERBOSE)
3563 c_write_str(ssh, "No passphrase required.\r\n");
3566 int ret; /* need not be kept over crReturn */
3567 s->cur_prompt = new_prompts(ssh->frontend);
3568 s->cur_prompt->to_server = FALSE;
3569 s->cur_prompt->name = dupstr("SSH key passphrase");
3570 add_prompt(s->cur_prompt,
3571 dupprintf("Passphrase for key \"%.100s\": ",
3572 s->publickey_comment),
3573 FALSE, SSH_MAX_PASSWORD_LEN);
3574 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3577 crWaitUntil(!pktin);
3578 ret = get_userpass_input(s->cur_prompt, in, inlen);
3582 /* Failed to get a passphrase. Terminate. */
3583 free_prompts(s->cur_prompt);
3584 ssh_disconnect(ssh, NULL, "Unable to authenticate",
3588 passphrase = dupstr(s->cur_prompt->prompts[0]->result);
3589 free_prompts(s->cur_prompt);
3592 * Try decrypting key with passphrase.
3594 ret = loadrsakey(&ssh->cfg.keyfile, &s->key, passphrase,
3597 memset(passphrase, 0, strlen(passphrase));
3601 /* Correct passphrase. */
3602 got_passphrase = TRUE;
3603 } else if (ret == 0) {
3604 c_write_str(ssh, "Couldn't load private key from ");
3605 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3606 c_write_str(ssh, " (");
3607 c_write_str(ssh, error);
3608 c_write_str(ssh, ").\r\n");
3609 got_passphrase = FALSE;
3610 break; /* go and try something else */
3611 } else if (ret == -1) {
3612 c_write_str(ssh, "Wrong passphrase.\r\n"); /* FIXME */
3613 got_passphrase = FALSE;
3616 assert(0 && "unexpected return from loadrsakey()");
3617 got_passphrase = FALSE; /* placate optimisers */
3621 if (got_passphrase) {
3624 * Send a public key attempt.
3626 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3627 PKT_BIGNUM, s->key.modulus, PKT_END);
3630 if (pktin->type == SSH1_SMSG_FAILURE) {
3631 c_write_str(ssh, "Server refused our public key.\r\n");
3632 continue; /* go and try something else */
3634 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3635 bombout(("Bizarre response to offer of public key"));
3641 unsigned char buffer[32];
3642 Bignum challenge, response;
3644 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3645 bombout(("Server's RSA challenge was badly formatted"));
3648 response = rsadecrypt(challenge, &s->key);
3649 freebn(s->key.private_exponent);/* burn the evidence */
3651 for (i = 0; i < 32; i++) {
3652 buffer[i] = bignum_byte(response, 31 - i);
3656 MD5Update(&md5c, buffer, 32);
3657 MD5Update(&md5c, s->session_id, 16);
3658 MD5Final(buffer, &md5c);
3660 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3661 PKT_DATA, buffer, 16, PKT_END);
3668 if (pktin->type == SSH1_SMSG_FAILURE) {
3669 if (flags & FLAG_VERBOSE)
3670 c_write_str(ssh, "Failed to authenticate with"
3671 " our public key.\r\n");
3672 continue; /* go and try something else */
3673 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3674 bombout(("Bizarre response to RSA authentication response"));
3678 break; /* we're through! */
3684 * Otherwise, try various forms of password-like authentication.
3686 s->cur_prompt = new_prompts(ssh->frontend);
3688 if (ssh->cfg.try_tis_auth &&
3689 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3690 !s->tis_auth_refused) {
3691 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3692 logevent("Requested TIS authentication");
3693 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3695 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3696 logevent("TIS authentication declined");
3697 if (flags & FLAG_INTERACTIVE)
3698 c_write_str(ssh, "TIS authentication refused.\r\n");
3699 s->tis_auth_refused = 1;
3704 char *instr_suf, *prompt;
3706 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3708 bombout(("TIS challenge packet was badly formed"));
3711 logevent("Received TIS challenge");
3712 s->cur_prompt->to_server = TRUE;
3713 s->cur_prompt->name = dupstr("SSH TIS authentication");
3714 /* Prompt heuristic comes from OpenSSH */
3715 if (memchr(challenge, '\n', challengelen)) {
3716 instr_suf = dupstr("");
3717 prompt = dupprintf("%.*s", challengelen, challenge);
3719 instr_suf = dupprintf("%.*s", challengelen, challenge);
3720 prompt = dupstr("Response: ");
3722 s->cur_prompt->instruction =
3723 dupprintf("Using TIS authentication.%s%s",
3724 (*instr_suf) ? "\n" : "",
3726 s->cur_prompt->instr_reqd = TRUE;
3727 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3731 if (ssh->cfg.try_tis_auth &&
3732 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3733 !s->ccard_auth_refused) {
3734 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3735 logevent("Requested CryptoCard authentication");
3736 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3738 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3739 logevent("CryptoCard authentication declined");
3740 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3741 s->ccard_auth_refused = 1;
3746 char *instr_suf, *prompt;
3748 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3750 bombout(("CryptoCard challenge packet was badly formed"));
3753 logevent("Received CryptoCard challenge");
3754 s->cur_prompt->to_server = TRUE;
3755 s->cur_prompt->name = dupstr("SSH CryptoCard authentication");
3756 s->cur_prompt->name_reqd = FALSE;
3757 /* Prompt heuristic comes from OpenSSH */
3758 if (memchr(challenge, '\n', challengelen)) {
3759 instr_suf = dupstr("");
3760 prompt = dupprintf("%.*s", challengelen, challenge);
3762 instr_suf = dupprintf("%.*s", challengelen, challenge);
3763 prompt = dupstr("Response: ");
3765 s->cur_prompt->instruction =
3766 dupprintf("Using CryptoCard authentication.%s%s",
3767 (*instr_suf) ? "\n" : "",
3769 s->cur_prompt->instr_reqd = TRUE;
3770 add_prompt(s->cur_prompt, prompt, FALSE, SSH_MAX_PASSWORD_LEN);
3774 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3775 s->cur_prompt->to_server = TRUE;
3776 s->cur_prompt->name = dupstr("SSH password");
3777 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
3778 s->username, ssh->savedhost),
3779 FALSE, SSH_MAX_PASSWORD_LEN);
3783 * Show password prompt, having first obtained it via a TIS
3784 * or CryptoCard exchange if we're doing TIS or CryptoCard
3788 int ret; /* need not be kept over crReturn */
3789 ret = get_userpass_input(s->cur_prompt, NULL, 0);
3792 crWaitUntil(!pktin);
3793 ret = get_userpass_input(s->cur_prompt, in, inlen);
3798 * Failed to get a password (for example
3799 * because one was supplied on the command line
3800 * which has already failed to work). Terminate.
3802 free_prompts(s->cur_prompt);
3803 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, TRUE);
3808 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3810 * Defence against traffic analysis: we send a
3811 * whole bunch of packets containing strings of
3812 * different lengths. One of these strings is the
3813 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3814 * The others are all random data in
3815 * SSH1_MSG_IGNORE packets. This way a passive
3816 * listener can't tell which is the password, and
3817 * hence can't deduce the password length.
3819 * Anybody with a password length greater than 16
3820 * bytes is going to have enough entropy in their
3821 * password that a listener won't find it _that_
3822 * much help to know how long it is. So what we'll
3825 * - if password length < 16, we send 15 packets
3826 * containing string lengths 1 through 15
3828 * - otherwise, we let N be the nearest multiple
3829 * of 8 below the password length, and send 8
3830 * packets containing string lengths N through
3831 * N+7. This won't obscure the order of
3832 * magnitude of the password length, but it will
3833 * introduce a bit of extra uncertainty.
3835 * A few servers can't deal with SSH1_MSG_IGNORE, at
3836 * least in this context. For these servers, we need
3837 * an alternative defence. We make use of the fact
3838 * that the password is interpreted as a C string:
3839 * so we can append a NUL, then some random data.
3841 * A few servers can deal with neither SSH1_MSG_IGNORE
3842 * here _nor_ a padded password string.
3843 * For these servers we are left with no defences
3844 * against password length sniffing.
3846 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE) &&
3847 !(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3849 * The server can deal with SSH1_MSG_IGNORE, so
3850 * we can use the primary defence.
3852 int bottom, top, pwlen, i;
3855 pwlen = strlen(s->cur_prompt->prompts[0]->result);
3857 bottom = 0; /* zero length passwords are OK! :-) */
3860 bottom = pwlen & ~7;
3864 assert(pwlen >= bottom && pwlen <= top);
3866 randomstr = snewn(top + 1, char);
3868 for (i = bottom; i <= top; i++) {
3870 defer_packet(ssh, s->pwpkt_type,
3871 PKTT_PASSWORD, PKT_STR,
3872 s->cur_prompt->prompts[0]->result,
3873 PKTT_OTHER, PKT_END);
3875 for (j = 0; j < i; j++) {
3877 randomstr[j] = random_byte();
3878 } while (randomstr[j] == '\0');
3880 randomstr[i] = '\0';
3881 defer_packet(ssh, SSH1_MSG_IGNORE,
3882 PKT_STR, randomstr, PKT_END);
3885 logevent("Sending password with camouflage packets");
3886 ssh_pkt_defersend(ssh);
3889 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3891 * The server can't deal with SSH1_MSG_IGNORE
3892 * but can deal with padded passwords, so we
3893 * can use the secondary defence.
3899 len = strlen(s->cur_prompt->prompts[0]->result);
3900 if (len < sizeof(string)) {
3902 strcpy(string, s->cur_prompt->prompts[0]->result);
3903 len++; /* cover the zero byte */
3904 while (len < sizeof(string)) {
3905 string[len++] = (char) random_byte();
3908 ss = s->cur_prompt->prompts[0]->result;
3910 logevent("Sending length-padded password");
3911 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3912 PKT_INT, len, PKT_DATA, ss, len,
3913 PKTT_OTHER, PKT_END);
3916 * The server is believed unable to cope with
3917 * any of our password camouflage methods.
3920 len = strlen(s->cur_prompt->prompts[0]->result);
3921 logevent("Sending unpadded password");
3922 send_packet(ssh, s->pwpkt_type,
3923 PKTT_PASSWORD, PKT_INT, len,
3924 PKT_DATA, s->cur_prompt->prompts[0]->result, len,
3925 PKTT_OTHER, PKT_END);
3928 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3929 PKT_STR, s->cur_prompt->prompts[0]->result,
3930 PKTT_OTHER, PKT_END);
3932 logevent("Sent password");
3933 free_prompts(s->cur_prompt);
3935 if (pktin->type == SSH1_SMSG_FAILURE) {
3936 if (flags & FLAG_VERBOSE)
3937 c_write_str(ssh, "Access denied\r\n");
3938 logevent("Authentication refused");
3939 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3940 bombout(("Strange packet received, type %d", pktin->type));
3946 if (s->publickey_blob) {
3947 sfree(s->publickey_blob);
3948 sfree(s->publickey_comment);
3951 logevent("Authentication successful");
3956 void sshfwd_close(struct ssh_channel *c)
3960 if (ssh->state == SSH_STATE_CLOSED)
3963 if (c && !c->closes) {
3965 * If halfopen is true, we have sent
3966 * CHANNEL_OPEN for this channel, but it hasn't even been
3967 * acknowledged by the server. So we must set a close flag
3968 * on it now, and then when the server acks the channel
3969 * open, we can close it then.
3972 if (ssh->version == 1) {
3973 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3976 struct Packet *pktout;
3977 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3978 ssh2_pkt_adduint32(pktout, c->remoteid);
3979 ssh2_pkt_send(ssh, pktout);
3982 c->closes = 1; /* sent MSG_CLOSE */
3983 if (c->type == CHAN_X11) {
3985 logevent("Forwarded X11 connection terminated");
3986 } else if (c->type == CHAN_SOCKDATA ||
3987 c->type == CHAN_SOCKDATA_DORMANT) {
3989 logevent("Forwarded port closed");
3994 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3998 if (ssh->state == SSH_STATE_CLOSED)
4001 if (ssh->version == 1) {
4002 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
4003 PKT_INT, c->remoteid,
4005 PKT_INT, len, PKT_DATA, buf, len,
4006 PKTT_OTHER, PKT_END);
4008 * In SSH-1 we can return 0 here - implying that forwarded
4009 * connections are never individually throttled - because
4010 * the only circumstance that can cause throttling will be
4011 * the whole SSH connection backing up, in which case
4012 * _everything_ will be throttled as a whole.
4016 ssh2_add_channel_data(c, buf, len);
4017 return ssh2_try_send(c);
4021 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4025 if (ssh->state == SSH_STATE_CLOSED)
4028 if (ssh->version == 1) {
4029 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
4030 c->v.v1.throttling = 0;
4031 ssh1_throttle(ssh, -1);
4034 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
4038 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4040 struct queued_handler *qh = ssh->qhead;
4044 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4047 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4048 ssh->packet_dispatch[qh->msg1] = NULL;
4051 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4052 ssh->packet_dispatch[qh->msg2] = NULL;
4056 ssh->qhead = qh->next;
4058 if (ssh->qhead->msg1 > 0) {
4059 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4060 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4062 if (ssh->qhead->msg2 > 0) {
4063 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4064 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4067 ssh->qhead = ssh->qtail = NULL;
4068 ssh->packet_dispatch[pktin->type] = NULL;
4071 qh->handler(ssh, pktin, qh->ctx);
4076 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4077 chandler_fn_t handler, void *ctx)
4079 struct queued_handler *qh;
4081 qh = snew(struct queued_handler);
4084 qh->handler = handler;
4088 if (ssh->qtail == NULL) {
4092 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4093 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4096 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4097 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4100 ssh->qtail->next = qh;
4105 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4107 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4109 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4110 SSH2_MSG_REQUEST_SUCCESS)) {
4111 logeventf(ssh, "Remote port forwarding from %s enabled",
4114 logeventf(ssh, "Remote port forwarding from %s refused",
4117 rpf = del234(ssh->rportfwds, pf);
4123 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
4125 const char *portfwd_strptr = cfg->portfwd;
4126 struct ssh_portfwd *epf;
4129 if (!ssh->portfwds) {
4130 ssh->portfwds = newtree234(ssh_portcmp);
4133 * Go through the existing port forwardings and tag them
4134 * with status==DESTROY. Any that we want to keep will be
4135 * re-enabled (status==KEEP) as we go through the
4136 * configuration and find out which bits are the same as
4139 struct ssh_portfwd *epf;
4141 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4142 epf->status = DESTROY;
4145 while (*portfwd_strptr) {
4146 char address_family, type;
4147 int sport,dport,sserv,dserv;
4148 char sports[256], dports[256], saddr[256], host[256];
4151 address_family = 'A';
4153 if (*portfwd_strptr == 'A' ||
4154 *portfwd_strptr == '4' ||
4155 *portfwd_strptr == '6')
4156 address_family = *portfwd_strptr++;
4157 if (*portfwd_strptr == 'L' ||
4158 *portfwd_strptr == 'R' ||
4159 *portfwd_strptr == 'D')
4160 type = *portfwd_strptr++;
4165 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4166 if (*portfwd_strptr == ':') {
4168 * We've seen a colon in the middle of the
4169 * source port number. This means that
4170 * everything we've seen until now is the
4171 * source _address_, so we'll move it into
4172 * saddr and start sports from the beginning
4177 if (ssh->version == 1 && type == 'R') {
4178 logeventf(ssh, "SSH-1 cannot handle remote source address "
4179 "spec \"%s\"; ignoring", sports);
4181 strcpy(saddr, sports);
4184 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4188 if (*portfwd_strptr == '\t')
4191 while (*portfwd_strptr && *portfwd_strptr != ':') {
4192 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4195 if (*portfwd_strptr == ':')
4198 while (*portfwd_strptr) {
4199 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4203 dport = atoi(dports);
4207 dport = net_service_lookup(dports);
4209 logeventf(ssh, "Service lookup failed for destination"
4210 " port \"%s\"", dports);
4214 while (*portfwd_strptr) portfwd_strptr++;
4218 portfwd_strptr++; /* eat the NUL and move to next one */
4220 sport = atoi(sports);
4224 sport = net_service_lookup(sports);
4226 logeventf(ssh, "Service lookup failed for source"
4227 " port \"%s\"", sports);
4230 if (sport && dport) {
4231 /* Set up a description of the source port. */
4232 struct ssh_portfwd *pfrec, *epfrec;
4234 pfrec = snew(struct ssh_portfwd);
4236 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4237 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4238 pfrec->sport = sport;
4239 pfrec->daddr = *host ? dupstr(host) : NULL;
4240 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4241 pfrec->dport = dport;
4242 pfrec->local = NULL;
4243 pfrec->remote = NULL;
4244 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4245 address_family == '6' ? ADDRTYPE_IPV6 :
4248 epfrec = add234(ssh->portfwds, pfrec);
4249 if (epfrec != pfrec) {
4251 * We already have a port forwarding with precisely
4252 * these parameters. Hence, no need to do anything;
4253 * simply tag the existing one as KEEP.
4255 epfrec->status = KEEP;
4256 free_portfwd(pfrec);
4258 pfrec->status = CREATE;
4264 * Now go through and destroy any port forwardings which were
4267 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4268 if (epf->status == DESTROY) {
4271 message = dupprintf("%s port forwarding from %s%s%d",
4272 epf->type == 'L' ? "local" :
4273 epf->type == 'R' ? "remote" : "dynamic",
4274 epf->saddr ? epf->saddr : "",
4275 epf->saddr ? ":" : "",
4278 if (epf->type != 'D') {
4279 char *msg2 = dupprintf("%s to %s:%d", message,
4280 epf->daddr, epf->dport);
4285 logeventf(ssh, "Cancelling %s", message);
4289 struct ssh_rportfwd *rpf = epf->remote;
4290 struct Packet *pktout;
4293 * Cancel the port forwarding at the server
4296 if (ssh->version == 1) {
4298 * We cannot cancel listening ports on the
4299 * server side in SSH-1! There's no message
4300 * to support it. Instead, we simply remove
4301 * the rportfwd record from the local end
4302 * so that any connections the server tries
4303 * to make on it are rejected.
4306 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4307 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4308 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4310 ssh2_pkt_addstring(pktout, epf->saddr);
4311 } else if (ssh->cfg.rport_acceptall) {
4312 /* XXX: ssh->cfg.rport_acceptall may not represent
4313 * what was used to open the original connection,
4314 * since it's reconfigurable. */
4315 ssh2_pkt_addstring(pktout, "0.0.0.0");
4317 ssh2_pkt_addstring(pktout, "127.0.0.1");
4319 ssh2_pkt_adduint32(pktout, epf->sport);
4320 ssh2_pkt_send(ssh, pktout);
4323 del234(ssh->rportfwds, rpf);
4325 } else if (epf->local) {
4326 pfd_terminate(epf->local);
4329 delpos234(ssh->portfwds, i);
4331 i--; /* so we don't skip one in the list */
4335 * And finally, set up any new port forwardings (status==CREATE).
4337 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4338 if (epf->status == CREATE) {
4339 char *sportdesc, *dportdesc;
4340 sportdesc = dupprintf("%s%s%s%s%d%s",
4341 epf->saddr ? epf->saddr : "",
4342 epf->saddr ? ":" : "",
4343 epf->sserv ? epf->sserv : "",
4344 epf->sserv ? "(" : "",
4346 epf->sserv ? ")" : "");
4347 if (epf->type == 'D') {
4350 dportdesc = dupprintf("%s:%s%s%d%s",
4352 epf->dserv ? epf->dserv : "",
4353 epf->dserv ? "(" : "",
4355 epf->dserv ? ")" : "");
4358 if (epf->type == 'L') {
4359 const char *err = pfd_addforward(epf->daddr, epf->dport,
4360 epf->saddr, epf->sport,
4363 epf->addressfamily);
4365 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4366 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4367 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4368 sportdesc, dportdesc,
4369 err ? " failed: " : "", err ? err : "");
4370 } else if (epf->type == 'D') {
4371 const char *err = pfd_addforward(NULL, -1,
4372 epf->saddr, epf->sport,
4375 epf->addressfamily);
4377 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4378 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4379 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4381 err ? " failed: " : "", err ? err : "");
4383 struct ssh_rportfwd *pf;
4386 * Ensure the remote port forwardings tree exists.
4388 if (!ssh->rportfwds) {
4389 if (ssh->version == 1)
4390 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4392 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4395 pf = snew(struct ssh_rportfwd);
4396 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4397 pf->dhost[lenof(pf->dhost)-1] = '\0';
4398 pf->dport = epf->dport;
4399 pf->sport = epf->sport;
4400 if (add234(ssh->rportfwds, pf) != pf) {
4401 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4402 epf->daddr, epf->dport);
4405 logeventf(ssh, "Requesting remote port %s"
4406 " forward to %s", sportdesc, dportdesc);
4408 pf->sportdesc = sportdesc;
4413 if (ssh->version == 1) {
4414 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4415 PKT_INT, epf->sport,
4416 PKT_STR, epf->daddr,
4417 PKT_INT, epf->dport,
4419 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4421 ssh_rportfwd_succfail, pf);
4423 struct Packet *pktout;
4424 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4425 ssh2_pkt_addstring(pktout, "tcpip-forward");
4426 ssh2_pkt_addbool(pktout, 1);/* want reply */
4428 ssh2_pkt_addstring(pktout, epf->saddr);
4429 } else if (cfg->rport_acceptall) {
4430 ssh2_pkt_addstring(pktout, "0.0.0.0");
4432 ssh2_pkt_addstring(pktout, "127.0.0.1");
4434 ssh2_pkt_adduint32(pktout, epf->sport);
4435 ssh2_pkt_send(ssh, pktout);
4437 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4438 SSH2_MSG_REQUEST_FAILURE,
4439 ssh_rportfwd_succfail, pf);
4448 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4451 int stringlen, bufsize;
4453 ssh_pkt_getstring(pktin, &string, &stringlen);
4454 if (string == NULL) {
4455 bombout(("Incoming terminal data packet was badly formed"));
4459 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4461 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4462 ssh->v1_stdout_throttling = 1;
4463 ssh1_throttle(ssh, +1);
4467 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4469 /* Remote side is trying to open a channel to talk to our
4470 * X-Server. Give them back a local channel number. */
4471 struct ssh_channel *c;
4472 int remoteid = ssh_pkt_getuint32(pktin);
4474 logevent("Received X11 connect request");
4475 /* Refuse if X11 forwarding is disabled. */
4476 if (!ssh->X11_fwd_enabled) {
4477 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4478 PKT_INT, remoteid, PKT_END);
4479 logevent("Rejected X11 connect request");
4481 c = snew(struct ssh_channel);
4484 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4485 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4486 logevent("Opening X11 forward connection failed");
4488 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4489 PKT_INT, remoteid, PKT_END);
4492 ("Opening X11 forward connection succeeded");
4493 c->remoteid = remoteid;
4494 c->halfopen = FALSE;
4495 c->localid = alloc_channel_id(ssh);
4497 c->v.v1.throttling = 0;
4498 c->type = CHAN_X11; /* identify channel type */
4499 add234(ssh->channels, c);
4500 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4501 PKT_INT, c->remoteid, PKT_INT,
4502 c->localid, PKT_END);
4503 logevent("Opened X11 forward channel");
4508 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4510 /* Remote side is trying to open a channel to talk to our
4511 * agent. Give them back a local channel number. */
4512 struct ssh_channel *c;
4513 int remoteid = ssh_pkt_getuint32(pktin);
4515 /* Refuse if agent forwarding is disabled. */
4516 if (!ssh->agentfwd_enabled) {
4517 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4518 PKT_INT, remoteid, PKT_END);
4520 c = snew(struct ssh_channel);
4522 c->remoteid = remoteid;
4523 c->halfopen = FALSE;
4524 c->localid = alloc_channel_id(ssh);
4526 c->v.v1.throttling = 0;
4527 c->type = CHAN_AGENT; /* identify channel type */
4528 c->u.a.lensofar = 0;
4529 add234(ssh->channels, c);
4530 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4531 PKT_INT, c->remoteid, PKT_INT, c->localid,
4536 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4538 /* Remote side is trying to open a channel to talk to a
4539 * forwarded port. Give them back a local channel number. */
4540 struct ssh_channel *c;
4541 struct ssh_rportfwd pf, *pfp;
4546 c = snew(struct ssh_channel);
4549 remoteid = ssh_pkt_getuint32(pktin);
4550 ssh_pkt_getstring(pktin, &host, &hostsize);
4551 port = ssh_pkt_getuint32(pktin);
4553 if (hostsize >= lenof(pf.dhost))
4554 hostsize = lenof(pf.dhost)-1;
4555 memcpy(pf.dhost, host, hostsize);
4556 pf.dhost[hostsize] = '\0';
4558 pfp = find234(ssh->rportfwds, &pf, NULL);
4561 logeventf(ssh, "Rejected remote port open request for %s:%d",
4563 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4564 PKT_INT, remoteid, PKT_END);
4566 logeventf(ssh, "Received remote port open request for %s:%d",
4568 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4569 c, &ssh->cfg, pfp->pfrec->addressfamily);
4571 logeventf(ssh, "Port open failed: %s", e);
4573 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4574 PKT_INT, remoteid, PKT_END);
4576 c->remoteid = remoteid;
4577 c->halfopen = FALSE;
4578 c->localid = alloc_channel_id(ssh);
4580 c->v.v1.throttling = 0;
4581 c->type = CHAN_SOCKDATA; /* identify channel type */
4582 add234(ssh->channels, c);
4583 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4584 PKT_INT, c->remoteid, PKT_INT,
4585 c->localid, PKT_END);
4586 logevent("Forwarded port opened successfully");
4591 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4593 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4594 unsigned int localid = ssh_pkt_getuint32(pktin);
4595 struct ssh_channel *c;
4597 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4598 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4599 c->remoteid = localid;
4600 c->halfopen = FALSE;
4601 c->type = CHAN_SOCKDATA;
4602 c->v.v1.throttling = 0;
4603 pfd_confirm(c->u.pfd.s);
4606 if (c && c->closes) {
4608 * We have a pending close on this channel,
4609 * which we decided on before the server acked
4610 * the channel open. So now we know the
4611 * remoteid, we can close it again.
4613 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4614 PKT_INT, c->remoteid, PKT_END);
4618 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4620 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4621 struct ssh_channel *c;
4623 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4624 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4625 logevent("Forwarded connection refused by server");
4626 pfd_close(c->u.pfd.s);
4627 del234(ssh->channels, c);
4632 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4634 /* Remote side closes a channel. */
4635 unsigned i = ssh_pkt_getuint32(pktin);
4636 struct ssh_channel *c;
4637 c = find234(ssh->channels, &i, ssh_channelfind);
4638 if (c && !c->halfopen) {
4641 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4643 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4644 logevent("Forwarded X11 connection terminated");
4645 assert(c->u.x11.s != NULL);
4646 x11_close(c->u.x11.s);
4649 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4650 logevent("Forwarded port closed");
4651 assert(c->u.pfd.s != NULL);
4652 pfd_close(c->u.pfd.s);
4656 c->closes |= (closetype << 2); /* seen this message */
4657 if (!(c->closes & closetype)) {
4658 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4660 c->closes |= closetype; /* sent it too */
4663 if (c->closes == 15) {
4664 del234(ssh->channels, c);
4668 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4669 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4670 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4675 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4677 /* Data sent down one of our channels. */
4678 int i = ssh_pkt_getuint32(pktin);
4681 struct ssh_channel *c;
4683 ssh_pkt_getstring(pktin, &p, &len);
4685 c = find234(ssh->channels, &i, ssh_channelfind);
4690 bufsize = x11_send(c->u.x11.s, p, len);
4693 bufsize = pfd_send(c->u.pfd.s, p, len);
4696 /* Data for an agent message. Buffer it. */
4698 if (c->u.a.lensofar < 4) {
4699 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
4700 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4704 c->u.a.lensofar += l;
4706 if (c->u.a.lensofar == 4) {
4708 4 + GET_32BIT(c->u.a.msglen);
4709 c->u.a.message = snewn(c->u.a.totallen,
4711 memcpy(c->u.a.message, c->u.a.msglen, 4);
4713 if (c->u.a.lensofar >= 4 && len > 0) {
4715 min(c->u.a.totallen - c->u.a.lensofar,
4717 memcpy(c->u.a.message + c->u.a.lensofar, p,
4721 c->u.a.lensofar += l;
4723 if (c->u.a.lensofar == c->u.a.totallen) {
4726 if (agent_query(c->u.a.message,
4729 ssh_agentf_callback, c))
4730 ssh_agentf_callback(c, reply, replylen);
4731 sfree(c->u.a.message);
4732 c->u.a.lensofar = 0;
4735 bufsize = 0; /* agent channels never back up */
4738 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4739 c->v.v1.throttling = 1;
4740 ssh1_throttle(ssh, +1);
4745 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4747 ssh->exitcode = ssh_pkt_getuint32(pktin);
4748 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4749 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4751 * In case `helpful' firewalls or proxies tack
4752 * extra human-readable text on the end of the
4753 * session which we might mistake for another
4754 * encrypted packet, we close the session once
4755 * we've sent EXIT_CONFIRMATION.
4757 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4760 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4761 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4763 struct Packet *pktout = (struct Packet *)data;
4765 unsigned int arg = 0;
4766 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4767 if (i == lenof(ssh_ttymodes)) return;
4768 switch (ssh_ttymodes[i].type) {
4770 arg = ssh_tty_parse_specchar(val);
4773 arg = ssh_tty_parse_boolean(val);
4776 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4777 ssh2_pkt_addbyte(pktout, arg);
4781 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4782 struct Packet *pktin)
4784 crBegin(ssh->do_ssh1_connection_crstate);
4786 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4787 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4788 ssh1_smsg_stdout_stderr_data;
4790 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4791 ssh1_msg_channel_open_confirmation;
4792 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4793 ssh1_msg_channel_open_failure;
4794 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4795 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4796 ssh1_msg_channel_close;
4797 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4798 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4800 if (ssh->cfg.agentfwd && agent_exists()) {
4801 logevent("Requesting agent forwarding");
4802 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4806 if (pktin->type != SSH1_SMSG_SUCCESS
4807 && pktin->type != SSH1_SMSG_FAILURE) {
4808 bombout(("Protocol confusion"));
4810 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4811 logevent("Agent forwarding refused");
4813 logevent("Agent forwarding enabled");
4814 ssh->agentfwd_enabled = TRUE;
4815 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4819 if (ssh->cfg.x11_forward) {
4820 char proto[20], data[64];
4821 logevent("Requesting X11 forwarding");
4822 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4823 data, sizeof(data), ssh->cfg.x11_auth);
4824 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4826 * Note that while we blank the X authentication data here, we don't
4827 * take any special action to blank the start of an X11 channel,
4828 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4829 * without having session blanking enabled is likely to leak your
4830 * cookie into the log.
4832 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4833 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4835 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4836 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4839 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4841 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4846 if (pktin->type != SSH1_SMSG_SUCCESS
4847 && pktin->type != SSH1_SMSG_FAILURE) {
4848 bombout(("Protocol confusion"));
4850 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4851 logevent("X11 forwarding refused");
4853 logevent("X11 forwarding enabled");
4854 ssh->X11_fwd_enabled = TRUE;
4855 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4859 ssh_setup_portfwd(ssh, &ssh->cfg);
4860 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4862 if (!ssh->cfg.nopty) {
4864 /* Unpick the terminal-speed string. */
4865 /* XXX perhaps we should allow no speeds to be sent. */
4866 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4867 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4868 /* Send the pty request. */
4869 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4870 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4871 ssh_pkt_adduint32(pkt, ssh->term_height);
4872 ssh_pkt_adduint32(pkt, ssh->term_width);
4873 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4874 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4875 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4876 ssh1_send_ttymode, (void *)pkt);
4877 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4878 ssh_pkt_adduint32(pkt, ssh->ispeed);
4879 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4880 ssh_pkt_adduint32(pkt, ssh->ospeed);
4881 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4883 ssh->state = SSH_STATE_INTERMED;
4887 if (pktin->type != SSH1_SMSG_SUCCESS
4888 && pktin->type != SSH1_SMSG_FAILURE) {
4889 bombout(("Protocol confusion"));
4891 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4892 c_write_str(ssh, "Server refused to allocate pty\r\n");
4893 ssh->editing = ssh->echoing = 1;
4895 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4896 ssh->ospeed, ssh->ispeed);
4898 ssh->editing = ssh->echoing = 1;
4901 if (ssh->cfg.compression) {
4902 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4906 if (pktin->type != SSH1_SMSG_SUCCESS
4907 && pktin->type != SSH1_SMSG_FAILURE) {
4908 bombout(("Protocol confusion"));
4910 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4911 c_write_str(ssh, "Server refused to compress\r\n");
4913 logevent("Started compression");
4914 ssh->v1_compressing = TRUE;
4915 ssh->cs_comp_ctx = zlib_compress_init();
4916 logevent("Initialised zlib (RFC1950) compression");
4917 ssh->sc_comp_ctx = zlib_decompress_init();
4918 logevent("Initialised zlib (RFC1950) decompression");
4922 * Start the shell or command.
4924 * Special case: if the first-choice command is an SSH-2
4925 * subsystem (hence not usable here) and the second choice
4926 * exists, we fall straight back to that.
4929 char *cmd = ssh->cfg.remote_cmd_ptr;
4931 if (!cmd) cmd = ssh->cfg.remote_cmd;
4933 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4934 cmd = ssh->cfg.remote_cmd_ptr2;
4935 ssh->fallback_cmd = TRUE;
4938 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4940 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4941 logevent("Started session");
4944 ssh->state = SSH_STATE_SESSION;
4945 if (ssh->size_needed)
4946 ssh_size(ssh, ssh->term_width, ssh->term_height);
4947 if (ssh->eof_needed)
4948 ssh_special(ssh, TS_EOF);
4951 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4953 ssh->channels = newtree234(ssh_channelcmp);
4957 * By this point, most incoming packets are already being
4958 * handled by the dispatch table, and we need only pay
4959 * attention to the unusual ones.
4964 if (pktin->type == SSH1_SMSG_SUCCESS) {
4965 /* may be from EXEC_SHELL on some servers */
4966 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4967 /* may be from EXEC_SHELL on some servers
4968 * if no pty is available or in other odd cases. Ignore */
4970 bombout(("Strange packet received: type %d", pktin->type));
4975 int len = min(inlen, 512);
4976 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4977 PKT_INT, len, PKT_DATA, in, len,
4978 PKTT_OTHER, PKT_END);
4989 * Handle the top-level SSH-2 protocol.
4991 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4996 ssh_pkt_getstring(pktin, &msg, &msglen);
4997 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
5000 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5002 /* log reason code in disconnect message */
5006 ssh_pkt_getstring(pktin, &msg, &msglen);
5007 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5010 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5012 /* Do nothing, because we're ignoring it! Duhh. */
5015 static void ssh1_protocol_setup(Ssh ssh)
5020 * Most messages are handled by the coroutines.
5022 for (i = 0; i < 256; i++)
5023 ssh->packet_dispatch[i] = NULL;
5026 * These special message types we install handlers for.
5028 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5029 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5030 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5033 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5034 struct Packet *pktin)
5036 unsigned char *in=(unsigned char*)vin;
5037 if (ssh->state == SSH_STATE_CLOSED)
5040 if (pktin && ssh->packet_dispatch[pktin->type]) {
5041 ssh->packet_dispatch[pktin->type](ssh, pktin);
5045 if (!ssh->protocol_initial_phase_done) {
5046 if (do_ssh1_login(ssh, in, inlen, pktin))
5047 ssh->protocol_initial_phase_done = TRUE;
5052 do_ssh1_connection(ssh, in, inlen, pktin);
5056 * Utility routine for decoding comma-separated strings in KEXINIT.
5058 static int in_commasep_string(char *needle, char *haystack, int haylen)
5061 if (!needle || !haystack) /* protect against null pointers */
5063 needlen = strlen(needle);
5066 * Is it at the start of the string?
5068 if (haylen >= needlen && /* haystack is long enough */
5069 !memcmp(needle, haystack, needlen) && /* initial match */
5070 (haylen == needlen || haystack[needlen] == ',')
5071 /* either , or EOS follows */
5075 * If not, search for the next comma and resume after that.
5076 * If no comma found, terminate.
5078 while (haylen > 0 && *haystack != ',')
5079 haylen--, haystack++;
5082 haylen--, haystack++; /* skip over comma itself */
5087 * Similar routine for checking whether we have the first string in a list.
5089 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5092 if (!needle || !haystack) /* protect against null pointers */
5094 needlen = strlen(needle);
5096 * Is it at the start of the string?
5098 if (haylen >= needlen && /* haystack is long enough */
5099 !memcmp(needle, haystack, needlen) && /* initial match */
5100 (haylen == needlen || haystack[needlen] == ',')
5101 /* either , or EOS follows */
5109 * SSH-2 key creation method.
5110 * (Currently assumes 2 lots of any hash are sufficient to generate
5111 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5113 #define SSH2_MKKEY_ITERS (2)
5114 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5115 unsigned char *keyspace)
5117 const struct ssh_hash *h = ssh->kex->hash;
5119 /* First hlen bytes. */
5121 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5122 hash_mpint(h, s, K);
5123 h->bytes(s, H, h->hlen);
5124 h->bytes(s, &chr, 1);
5125 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5126 h->final(s, keyspace);
5127 /* Next hlen bytes. */
5129 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5130 hash_mpint(h, s, K);
5131 h->bytes(s, H, h->hlen);
5132 h->bytes(s, keyspace, h->hlen);
5133 h->final(s, keyspace + h->hlen);
5137 * Handle the SSH-2 transport layer.
5139 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5140 struct Packet *pktin)
5142 unsigned char *in = (unsigned char *)vin;
5143 struct do_ssh2_transport_state {
5144 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5145 Bignum p, g, e, f, K;
5148 int kex_init_value, kex_reply_value;
5149 const struct ssh_mac **maclist;
5151 const struct ssh2_cipher *cscipher_tobe;
5152 const struct ssh2_cipher *sccipher_tobe;
5153 const struct ssh_mac *csmac_tobe;
5154 const struct ssh_mac *scmac_tobe;
5155 const struct ssh_compress *cscomp_tobe;
5156 const struct ssh_compress *sccomp_tobe;
5157 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5158 int hostkeylen, siglen, rsakeylen;
5159 void *hkey; /* actual host key */
5160 void *rsakey; /* for RSA kex */
5161 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5162 int n_preferred_kex;
5163 const struct ssh_kexes *preferred_kex[KEX_MAX];
5164 int n_preferred_ciphers;
5165 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5166 const struct ssh_compress *preferred_comp;
5167 int got_session_id, activated_authconn;
5168 struct Packet *pktout;
5173 crState(do_ssh2_transport_state);
5175 crBegin(ssh->do_ssh2_transport_crstate);
5177 s->cscipher_tobe = s->sccipher_tobe = NULL;
5178 s->csmac_tobe = s->scmac_tobe = NULL;
5179 s->cscomp_tobe = s->sccomp_tobe = NULL;
5181 s->got_session_id = s->activated_authconn = FALSE;
5184 * Be prepared to work around the buggy MAC problem.
5186 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5187 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5189 s->maclist = macs, s->nmacs = lenof(macs);
5192 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5194 int i, j, commalist_started;
5197 * Set up the preferred key exchange. (NULL => warn below here)
5199 s->n_preferred_kex = 0;
5200 for (i = 0; i < KEX_MAX; i++) {
5201 switch (ssh->cfg.ssh_kexlist[i]) {
5203 s->preferred_kex[s->n_preferred_kex++] =
5204 &ssh_diffiehellman_gex;
5207 s->preferred_kex[s->n_preferred_kex++] =
5208 &ssh_diffiehellman_group14;
5211 s->preferred_kex[s->n_preferred_kex++] =
5212 &ssh_diffiehellman_group1;
5215 s->preferred_kex[s->n_preferred_kex++] =
5219 /* Flag for later. Don't bother if it's the last in
5221 if (i < KEX_MAX - 1) {
5222 s->preferred_kex[s->n_preferred_kex++] = NULL;
5229 * Set up the preferred ciphers. (NULL => warn below here)
5231 s->n_preferred_ciphers = 0;
5232 for (i = 0; i < CIPHER_MAX; i++) {
5233 switch (ssh->cfg.ssh_cipherlist[i]) {
5234 case CIPHER_BLOWFISH:
5235 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5238 if (ssh->cfg.ssh2_des_cbc) {
5239 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5243 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5246 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5248 case CIPHER_ARCFOUR:
5249 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5252 /* Flag for later. Don't bother if it's the last in
5254 if (i < CIPHER_MAX - 1) {
5255 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5262 * Set up preferred compression.
5264 if (ssh->cfg.compression)
5265 s->preferred_comp = &ssh_zlib;
5267 s->preferred_comp = &ssh_comp_none;
5270 * Enable queueing of outgoing auth- or connection-layer
5271 * packets while we are in the middle of a key exchange.
5273 ssh->queueing = TRUE;
5276 * Flag that KEX is in progress.
5278 ssh->kex_in_progress = TRUE;
5281 * Construct and send our key exchange packet.
5283 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5284 for (i = 0; i < 16; i++)
5285 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5286 /* List key exchange algorithms. */
5287 ssh2_pkt_addstring_start(s->pktout);
5288 commalist_started = 0;
5289 for (i = 0; i < s->n_preferred_kex; i++) {
5290 const struct ssh_kexes *k = s->preferred_kex[i];
5291 if (!k) continue; /* warning flag */
5292 for (j = 0; j < k->nkexes; j++) {
5293 if (commalist_started)
5294 ssh2_pkt_addstring_str(s->pktout, ",");
5295 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5296 commalist_started = 1;
5299 /* List server host key algorithms. */
5300 ssh2_pkt_addstring_start(s->pktout);
5301 for (i = 0; i < lenof(hostkey_algs); i++) {
5302 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5303 if (i < lenof(hostkey_algs) - 1)
5304 ssh2_pkt_addstring_str(s->pktout, ",");
5306 /* List client->server encryption algorithms. */
5307 ssh2_pkt_addstring_start(s->pktout);
5308 commalist_started = 0;
5309 for (i = 0; i < s->n_preferred_ciphers; i++) {
5310 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5311 if (!c) continue; /* warning flag */
5312 for (j = 0; j < c->nciphers; j++) {
5313 if (commalist_started)
5314 ssh2_pkt_addstring_str(s->pktout, ",");
5315 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5316 commalist_started = 1;
5319 /* List server->client encryption algorithms. */
5320 ssh2_pkt_addstring_start(s->pktout);
5321 commalist_started = 0;
5322 for (i = 0; i < s->n_preferred_ciphers; i++) {
5323 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5324 if (!c) continue; /* warning flag */
5325 for (j = 0; j < c->nciphers; j++) {
5326 if (commalist_started)
5327 ssh2_pkt_addstring_str(s->pktout, ",");
5328 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5329 commalist_started = 1;
5332 /* List client->server MAC algorithms. */
5333 ssh2_pkt_addstring_start(s->pktout);
5334 for (i = 0; i < s->nmacs; i++) {
5335 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5336 if (i < s->nmacs - 1)
5337 ssh2_pkt_addstring_str(s->pktout, ",");
5339 /* List server->client MAC algorithms. */
5340 ssh2_pkt_addstring_start(s->pktout);
5341 for (i = 0; i < s->nmacs; i++) {
5342 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5343 if (i < s->nmacs - 1)
5344 ssh2_pkt_addstring_str(s->pktout, ",");
5346 /* List client->server compression algorithms. */
5347 ssh2_pkt_addstring_start(s->pktout);
5348 assert(lenof(compressions) > 1);
5349 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5350 for (i = 0; i < lenof(compressions); i++) {
5351 const struct ssh_compress *c = compressions[i];
5352 if (c != s->preferred_comp) {
5353 ssh2_pkt_addstring_str(s->pktout, ",");
5354 ssh2_pkt_addstring_str(s->pktout, c->name);
5357 /* List server->client compression algorithms. */
5358 ssh2_pkt_addstring_start(s->pktout);
5359 assert(lenof(compressions) > 1);
5360 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5361 for (i = 0; i < lenof(compressions); i++) {
5362 const struct ssh_compress *c = compressions[i];
5363 if (c != s->preferred_comp) {
5364 ssh2_pkt_addstring_str(s->pktout, ",");
5365 ssh2_pkt_addstring_str(s->pktout, c->name);
5368 /* List client->server languages. Empty list. */
5369 ssh2_pkt_addstring_start(s->pktout);
5370 /* List server->client languages. Empty list. */
5371 ssh2_pkt_addstring_start(s->pktout);
5372 /* First KEX packet does _not_ follow, because we're not that brave. */
5373 ssh2_pkt_addbool(s->pktout, FALSE);
5375 ssh2_pkt_adduint32(s->pktout, 0);
5378 s->our_kexinitlen = s->pktout->length - 5;
5379 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5380 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5382 ssh2_pkt_send_noqueue(ssh, s->pktout);
5388 * Now examine the other side's KEXINIT to see what we're up
5392 char *str, *preferred;
5395 if (pktin->type != SSH2_MSG_KEXINIT) {
5396 bombout(("expected key exchange packet from server"));
5400 ssh->hostkey = NULL;
5401 s->cscipher_tobe = NULL;
5402 s->sccipher_tobe = NULL;
5403 s->csmac_tobe = NULL;
5404 s->scmac_tobe = NULL;
5405 s->cscomp_tobe = NULL;
5406 s->sccomp_tobe = NULL;
5407 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5409 pktin->savedpos += 16; /* skip garbage cookie */
5410 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5413 for (i = 0; i < s->n_preferred_kex; i++) {
5414 const struct ssh_kexes *k = s->preferred_kex[i];
5418 for (j = 0; j < k->nkexes; j++) {
5419 if (!preferred) preferred = k->list[j]->name;
5420 if (in_commasep_string(k->list[j]->name, str, len)) {
5421 ssh->kex = k->list[j];
5430 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5431 str ? str : "(null)"));
5435 * Note that the server's guess is considered wrong if it doesn't match
5436 * the first algorithm in our list, even if it's still the algorithm
5439 s->guessok = first_in_commasep_string(preferred, str, len);
5440 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5441 for (i = 0; i < lenof(hostkey_algs); i++) {
5442 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5443 ssh->hostkey = hostkey_algs[i];
5447 s->guessok = s->guessok &&
5448 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5449 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5450 for (i = 0; i < s->n_preferred_ciphers; i++) {
5451 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5453 s->warn_cscipher = TRUE;
5455 for (j = 0; j < c->nciphers; j++) {
5456 if (in_commasep_string(c->list[j]->name, str, len)) {
5457 s->cscipher_tobe = c->list[j];
5462 if (s->cscipher_tobe)
5465 if (!s->cscipher_tobe) {
5466 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5467 str ? str : "(null)"));
5471 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5472 for (i = 0; i < s->n_preferred_ciphers; i++) {
5473 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5475 s->warn_sccipher = TRUE;
5477 for (j = 0; j < c->nciphers; j++) {
5478 if (in_commasep_string(c->list[j]->name, str, len)) {
5479 s->sccipher_tobe = c->list[j];
5484 if (s->sccipher_tobe)
5487 if (!s->sccipher_tobe) {
5488 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5489 str ? str : "(null)"));
5493 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5494 for (i = 0; i < s->nmacs; i++) {
5495 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5496 s->csmac_tobe = s->maclist[i];
5500 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5501 for (i = 0; i < s->nmacs; i++) {
5502 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5503 s->scmac_tobe = s->maclist[i];
5507 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5508 for (i = 0; i < lenof(compressions) + 1; i++) {
5509 const struct ssh_compress *c =
5510 i == 0 ? s->preferred_comp : compressions[i - 1];
5511 if (in_commasep_string(c->name, str, len)) {
5516 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5517 for (i = 0; i < lenof(compressions) + 1; i++) {
5518 const struct ssh_compress *c =
5519 i == 0 ? s->preferred_comp : compressions[i - 1];
5520 if (in_commasep_string(c->name, str, len)) {
5525 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5526 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5527 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5530 ssh_set_frozen(ssh, 1);
5531 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5533 ssh_dialog_callback, ssh);
5534 if (s->dlgret < 0) {
5538 bombout(("Unexpected data from server while"
5539 " waiting for user response"));
5542 } while (pktin || inlen > 0);
5543 s->dlgret = ssh->user_response;
5545 ssh_set_frozen(ssh, 0);
5546 if (s->dlgret == 0) {
5547 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5553 if (s->warn_cscipher) {
5554 ssh_set_frozen(ssh, 1);
5555 s->dlgret = askalg(ssh->frontend,
5556 "client-to-server cipher",
5557 s->cscipher_tobe->name,
5558 ssh_dialog_callback, ssh);
5559 if (s->dlgret < 0) {
5563 bombout(("Unexpected data from server while"
5564 " waiting for user response"));
5567 } while (pktin || inlen > 0);
5568 s->dlgret = ssh->user_response;
5570 ssh_set_frozen(ssh, 0);
5571 if (s->dlgret == 0) {
5572 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5578 if (s->warn_sccipher) {
5579 ssh_set_frozen(ssh, 1);
5580 s->dlgret = askalg(ssh->frontend,
5581 "server-to-client cipher",
5582 s->sccipher_tobe->name,
5583 ssh_dialog_callback, ssh);
5584 if (s->dlgret < 0) {
5588 bombout(("Unexpected data from server while"
5589 " waiting for user response"));
5592 } while (pktin || inlen > 0);
5593 s->dlgret = ssh->user_response;
5595 ssh_set_frozen(ssh, 0);
5596 if (s->dlgret == 0) {
5597 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5603 ssh->exhash = ssh->kex->hash->init();
5604 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5605 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5606 hash_string(ssh->kex->hash, ssh->exhash,
5607 s->our_kexinit, s->our_kexinitlen);
5608 sfree(s->our_kexinit);
5609 if (pktin->length > 5)
5610 hash_string(ssh->kex->hash, ssh->exhash,
5611 pktin->data + 5, pktin->length - 5);
5613 if (s->ignorepkt) /* first_kex_packet_follows */
5614 crWaitUntil(pktin); /* Ignore packet */
5617 if (ssh->kex->main_type == KEXTYPE_DH) {
5619 * Work out the number of bits of key we will need from the
5620 * key exchange. We start with the maximum key length of
5626 csbits = s->cscipher_tobe->keylen;
5627 scbits = s->sccipher_tobe->keylen;
5628 s->nbits = (csbits > scbits ? csbits : scbits);
5630 /* The keys only have hlen-bit entropy, since they're based on
5631 * a hash. So cap the key size at hlen bits. */
5632 if (s->nbits > ssh->kex->hash->hlen * 8)
5633 s->nbits = ssh->kex->hash->hlen * 8;
5636 * If we're doing Diffie-Hellman group exchange, start by
5637 * requesting a group.
5639 if (!ssh->kex->pdata) {
5640 logevent("Doing Diffie-Hellman group exchange");
5641 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
5643 * Work out how big a DH group we will need to allow that
5646 s->pbits = 512 << ((s->nbits - 1) / 64);
5647 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5648 ssh2_pkt_adduint32(s->pktout, s->pbits);
5649 ssh2_pkt_send_noqueue(ssh, s->pktout);
5652 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5653 bombout(("expected key exchange group packet from server"));
5656 s->p = ssh2_pkt_getmp(pktin);
5657 s->g = ssh2_pkt_getmp(pktin);
5658 if (!s->p || !s->g) {
5659 bombout(("unable to read mp-ints from incoming group packet"));
5662 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5663 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5664 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5666 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
5667 ssh->kex_ctx = dh_setup_group(ssh->kex);
5668 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5669 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5670 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5671 ssh->kex->groupname);
5674 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5675 ssh->kex->hash->text_name);
5677 * Now generate and send e for Diffie-Hellman.
5679 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5680 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5681 s->pktout = ssh2_pkt_init(s->kex_init_value);
5682 ssh2_pkt_addmp(s->pktout, s->e);
5683 ssh2_pkt_send_noqueue(ssh, s->pktout);
5685 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5687 if (pktin->type != s->kex_reply_value) {
5688 bombout(("expected key exchange reply packet from server"));
5691 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5692 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5693 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5694 s->f = ssh2_pkt_getmp(pktin);
5696 bombout(("unable to parse key exchange reply packet"));
5699 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5701 s->K = dh_find_K(ssh->kex_ctx, s->f);
5703 /* We assume everything from now on will be quick, and it might
5704 * involve user interaction. */
5705 set_busy_status(ssh->frontend, BUSY_NOT);
5707 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5708 if (!ssh->kex->pdata) {
5709 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5710 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5711 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5713 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5714 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5716 dh_cleanup(ssh->kex_ctx);
5718 if (!ssh->kex->pdata) {
5723 logeventf(ssh, "Doing RSA key exchange with hash %s",
5724 ssh->kex->hash->text_name);
5725 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
5727 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
5731 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
5732 bombout(("expected RSA public key packet from server"));
5736 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5737 hash_string(ssh->kex->hash, ssh->exhash,
5738 s->hostkeydata, s->hostkeylen);
5739 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5743 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
5744 s->rsakeydata = snewn(s->rsakeylen, char);
5745 memcpy(s->rsakeydata, keydata, s->rsakeylen);
5748 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
5750 sfree(s->rsakeydata);
5751 bombout(("unable to parse RSA public key from server"));
5755 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
5758 * Next, set up a shared secret K, of precisely KLEN -
5759 * 2*HLEN - 49 bits, where KLEN is the bit length of the
5760 * RSA key modulus and HLEN is the bit length of the hash
5764 int klen = ssh_rsakex_klen(s->rsakey);
5765 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
5767 unsigned char *kstr1, *kstr2, *outstr;
5768 int kstr1len, kstr2len, outstrlen;
5770 s->K = bn_power_2(nbits - 1);
5772 for (i = 0; i < nbits; i++) {
5774 byte = random_byte();
5776 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
5780 * Encode this as an mpint.
5782 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
5783 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
5784 PUT_32BIT(kstr2, kstr1len);
5785 memcpy(kstr2 + 4, kstr1, kstr1len);
5788 * Encrypt it with the given RSA key.
5790 outstrlen = (klen + 7) / 8;
5791 outstr = snewn(outstrlen, unsigned char);
5792 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
5793 outstr, outstrlen, s->rsakey);
5796 * And send it off in a return packet.
5798 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
5799 ssh2_pkt_addstring_start(s->pktout);
5800 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
5801 ssh2_pkt_send_noqueue(ssh, s->pktout);
5803 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
5810 ssh_rsakex_freekey(s->rsakey);
5813 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
5814 sfree(s->rsakeydata);
5815 bombout(("expected signature packet from server"));
5819 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5821 sfree(s->rsakeydata);
5824 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
5825 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
5826 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
5828 ssh->kex_ctx = NULL;
5831 debug(("Exchange hash is:\n"));
5832 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
5836 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5837 (char *)s->exchange_hash,
5838 ssh->kex->hash->hlen)) {
5839 bombout(("Server's host key did not match the signature supplied"));
5844 * Authenticate remote host: verify host key. (We've already
5845 * checked the signature of the exchange hash.)
5847 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5848 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5849 ssh_set_frozen(ssh, 1);
5850 s->dlgret = verify_ssh_host_key(ssh->frontend,
5851 ssh->savedhost, ssh->savedport,
5852 ssh->hostkey->keytype, s->keystr,
5854 ssh_dialog_callback, ssh);
5855 if (s->dlgret < 0) {
5859 bombout(("Unexpected data from server while waiting"
5860 " for user host key response"));
5863 } while (pktin || inlen > 0);
5864 s->dlgret = ssh->user_response;
5866 ssh_set_frozen(ssh, 0);
5867 if (s->dlgret == 0) {
5868 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5872 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5873 logevent("Host key fingerprint is:");
5874 logevent(s->fingerprint);
5876 sfree(s->fingerprint);
5878 ssh->hostkey->freekey(s->hkey);
5881 * The exchange hash from the very first key exchange is also
5882 * the session id, used in session key construction and
5885 if (!s->got_session_id) {
5886 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
5887 memcpy(ssh->v2_session_id, s->exchange_hash,
5888 sizeof(s->exchange_hash));
5889 ssh->v2_session_id_len = ssh->kex->hash->hlen;
5890 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
5891 s->got_session_id = TRUE;
5895 * Send SSH2_MSG_NEWKEYS.
5897 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5898 ssh2_pkt_send_noqueue(ssh, s->pktout);
5899 ssh->outgoing_data_size = 0; /* start counting from here */
5902 * We've sent client NEWKEYS, so create and initialise
5903 * client-to-server session keys.
5905 if (ssh->cs_cipher_ctx)
5906 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5907 ssh->cscipher = s->cscipher_tobe;
5908 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5910 if (ssh->cs_mac_ctx)
5911 ssh->csmac->free_context(ssh->cs_mac_ctx);
5912 ssh->csmac = s->csmac_tobe;
5913 ssh->cs_mac_ctx = ssh->csmac->make_context();
5915 if (ssh->cs_comp_ctx)
5916 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5917 ssh->cscomp = s->cscomp_tobe;
5918 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5921 * Set IVs on client-to-server keys. Here we use the exchange
5922 * hash from the _first_ key exchange.
5925 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
5926 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5927 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
5928 assert((ssh->cscipher->keylen+7) / 8 <=
5929 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5930 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5931 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
5932 assert(ssh->cscipher->blksize <=
5933 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5934 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5935 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
5936 assert(ssh->csmac->len <=
5937 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5938 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5939 memset(keyspace, 0, sizeof(keyspace));
5942 logeventf(ssh, "Initialised %.200s client->server encryption",
5943 ssh->cscipher->text_name);
5944 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5945 ssh->csmac->text_name);
5946 if (ssh->cscomp->text_name)
5947 logeventf(ssh, "Initialised %s compression",
5948 ssh->cscomp->text_name);
5951 * Now our end of the key exchange is complete, we can send all
5952 * our queued higher-layer packets.
5954 ssh->queueing = FALSE;
5955 ssh2_pkt_queuesend(ssh);
5958 * Expect SSH2_MSG_NEWKEYS from server.
5961 if (pktin->type != SSH2_MSG_NEWKEYS) {
5962 bombout(("expected new-keys packet from server"));
5965 ssh->incoming_data_size = 0; /* start counting from here */
5968 * We've seen server NEWKEYS, so create and initialise
5969 * server-to-client session keys.
5971 if (ssh->sc_cipher_ctx)
5972 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5973 ssh->sccipher = s->sccipher_tobe;
5974 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5976 if (ssh->sc_mac_ctx)
5977 ssh->scmac->free_context(ssh->sc_mac_ctx);
5978 ssh->scmac = s->scmac_tobe;
5979 ssh->sc_mac_ctx = ssh->scmac->make_context();
5981 if (ssh->sc_comp_ctx)
5982 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5983 ssh->sccomp = s->sccomp_tobe;
5984 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5987 * Set IVs on server-to-client keys. Here we use the exchange
5988 * hash from the _first_ key exchange.
5991 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
5992 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5993 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
5994 assert((ssh->sccipher->keylen+7) / 8 <=
5995 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5996 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5997 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
5998 assert(ssh->sccipher->blksize <=
5999 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6000 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6001 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6002 assert(ssh->scmac->len <=
6003 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6004 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6005 memset(keyspace, 0, sizeof(keyspace));
6007 logeventf(ssh, "Initialised %.200s server->client encryption",
6008 ssh->sccipher->text_name);
6009 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6010 ssh->scmac->text_name);
6011 if (ssh->sccomp->text_name)
6012 logeventf(ssh, "Initialised %s decompression",
6013 ssh->sccomp->text_name);
6016 * Free shared secret.
6021 * Key exchange is over. Loop straight back round if we have a
6022 * deferred rekey reason.
6024 if (ssh->deferred_rekey_reason) {
6025 logevent(ssh->deferred_rekey_reason);
6027 ssh->deferred_rekey_reason = NULL;
6028 goto begin_key_exchange;
6032 * Otherwise, schedule a timer for our next rekey.
6034 ssh->kex_in_progress = FALSE;
6035 ssh->last_rekey = GETTICKCOUNT();
6036 if (ssh->cfg.ssh_rekey_time != 0)
6037 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6041 * If this is the first key exchange phase, we must pass the
6042 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6043 * wants to see it but because it will need time to initialise
6044 * itself before it sees an actual packet. In subsequent key
6045 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6046 * it would only confuse the layer above.
6048 if (s->activated_authconn) {
6051 s->activated_authconn = TRUE;
6054 * Now we're encrypting. Begin returning 1 to the protocol main
6055 * function so that other things can run on top of the
6056 * transport. If we ever see a KEXINIT, we must go back to the
6059 * We _also_ go back to the start if we see pktin==NULL and
6060 * inlen==-1, because this is a special signal meaning
6061 * `initiate client-driven rekey', and `in' contains a message
6062 * giving the reason for the rekey.
6064 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6065 (!pktin && inlen == -1))) {
6070 logevent("Server initiated key re-exchange");
6073 * Special case: if the server bug is set that doesn't
6074 * allow rekeying, we give a different log message and
6075 * continue waiting. (If such a server _initiates_ a rekey,
6076 * we process it anyway!)
6078 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6079 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6081 /* Reset the counters, so that at least this message doesn't
6082 * hit the event log _too_ often. */
6083 ssh->outgoing_data_size = 0;
6084 ssh->incoming_data_size = 0;
6085 if (ssh->cfg.ssh_rekey_time != 0) {
6087 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6090 goto wait_for_rekey; /* this is utterly horrid */
6092 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6095 goto begin_key_exchange;
6101 * Add data to an SSH-2 channel output buffer.
6103 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6106 bufchain_add(&c->v.v2.outbuffer, buf, len);
6110 * Attempt to send data on an SSH-2 channel.
6112 static int ssh2_try_send(struct ssh_channel *c)
6115 struct Packet *pktout;
6117 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6120 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6121 if ((unsigned)len > c->v.v2.remwindow)
6122 len = c->v.v2.remwindow;
6123 if ((unsigned)len > c->v.v2.remmaxpkt)
6124 len = c->v.v2.remmaxpkt;
6125 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6126 ssh2_pkt_adduint32(pktout, c->remoteid);
6127 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6128 ssh2_pkt_addstring_start(pktout);
6129 ssh2_pkt_addstring_data(pktout, data, len);
6130 end_log_omission(ssh, pktout);
6131 ssh2_pkt_send(ssh, pktout);
6132 bufchain_consume(&c->v.v2.outbuffer, len);
6133 c->v.v2.remwindow -= len;
6137 * After having sent as much data as we can, return the amount
6140 return bufchain_size(&c->v.v2.outbuffer);
6143 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
6147 return; /* don't send on closing channels */
6148 bufsize = ssh2_try_send(c);
6151 case CHAN_MAINSESSION:
6152 /* stdin need not receive an unthrottle
6153 * notification since it will be polled */
6156 x11_unthrottle(c->u.x11.s);
6159 /* agent sockets are request/response and need no
6160 * buffer management */
6163 pfd_unthrottle(c->u.pfd.s);
6170 * Potentially enlarge the window on an SSH-2 channel.
6172 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
6177 * Never send WINDOW_ADJUST for a channel that the remote side
6178 * already thinks it's closed; there's no point, since it won't
6179 * be sending any more data anyway.
6185 * Only send a WINDOW_ADJUST if there's significantly more window
6186 * available than the other end thinks there is. This saves us
6187 * sending a WINDOW_ADJUST for every character in a shell session.
6189 * "Significant" is arbitrarily defined as half the window size.
6191 if (newwin > c->v.v2.locwindow * 2) {
6192 struct Packet *pktout;
6194 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6195 ssh2_pkt_adduint32(pktout, c->remoteid);
6196 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6197 ssh2_pkt_send(ssh, pktout);
6198 c->v.v2.locwindow = newwin;
6202 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6204 unsigned i = ssh_pkt_getuint32(pktin);
6205 struct ssh_channel *c;
6206 c = find234(ssh->channels, &i, ssh_channelfind);
6207 if (c && !c->closes) {
6208 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6209 ssh2_try_send_and_unthrottle(c);
6213 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6217 unsigned i = ssh_pkt_getuint32(pktin);
6218 struct ssh_channel *c;
6219 c = find234(ssh->channels, &i, ssh_channelfind);
6221 return; /* nonexistent channel */
6222 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6223 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6224 return; /* extended but not stderr */
6225 ssh_pkt_getstring(pktin, &data, &length);
6228 c->v.v2.locwindow -= length;
6230 case CHAN_MAINSESSION:
6232 from_backend(ssh->frontend, pktin->type ==
6233 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6237 bufsize = x11_send(c->u.x11.s, data, length);
6240 bufsize = pfd_send(c->u.pfd.s, data, length);
6243 while (length > 0) {
6244 if (c->u.a.lensofar < 4) {
6245 unsigned int l = min(4 - c->u.a.lensofar,
6247 memcpy(c->u.a.msglen + c->u.a.lensofar,
6251 c->u.a.lensofar += l;
6253 if (c->u.a.lensofar == 4) {
6255 4 + GET_32BIT(c->u.a.msglen);
6256 c->u.a.message = snewn(c->u.a.totallen,
6258 memcpy(c->u.a.message, c->u.a.msglen, 4);
6260 if (c->u.a.lensofar >= 4 && length > 0) {
6262 min(c->u.a.totallen - c->u.a.lensofar,
6264 memcpy(c->u.a.message + c->u.a.lensofar,
6268 c->u.a.lensofar += l;
6270 if (c->u.a.lensofar == c->u.a.totallen) {
6273 if (agent_query(c->u.a.message,
6276 ssh_agentf_callback, c))
6277 ssh_agentf_callback(c, reply, replylen);
6278 sfree(c->u.a.message);
6279 c->u.a.lensofar = 0;
6286 * If we are not buffering too much data,
6287 * enlarge the window again at the remote side.
6288 * If we are buffering too much, we may still
6289 * need to adjust the window if the server's
6292 ssh2_set_window(c, bufsize < OUR_V2_WINSIZE ?
6293 OUR_V2_WINSIZE - bufsize : 0);
6297 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6299 unsigned i = ssh_pkt_getuint32(pktin);
6300 struct ssh_channel *c;
6302 c = find234(ssh->channels, &i, ssh_channelfind);
6304 return; /* nonexistent channel */
6306 if (c->type == CHAN_X11) {
6308 * Remote EOF on an X11 channel means we should
6309 * wrap up and close the channel ourselves.
6311 x11_close(c->u.x11.s);
6313 } else if (c->type == CHAN_AGENT) {
6315 } else if (c->type == CHAN_SOCKDATA) {
6316 pfd_close(c->u.pfd.s);
6321 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6323 unsigned i = ssh_pkt_getuint32(pktin);
6324 struct ssh_channel *c;
6325 struct Packet *pktout;
6327 c = find234(ssh->channels, &i, ssh_channelfind);
6328 if (!c || c->halfopen) {
6329 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6330 c ? "half-open" : "nonexistent", i));
6333 /* Do pre-close processing on the channel. */
6335 case CHAN_MAINSESSION:
6336 ssh->mainchan = NULL;
6337 update_specials_menu(ssh->frontend);
6340 if (c->u.x11.s != NULL)
6341 x11_close(c->u.x11.s);
6348 if (c->u.pfd.s != NULL)
6349 pfd_close(c->u.pfd.s);
6353 if (c->closes == 0) {
6354 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6355 ssh2_pkt_adduint32(pktout, c->remoteid);
6356 ssh2_pkt_send(ssh, pktout);
6358 del234(ssh->channels, c);
6359 bufchain_clear(&c->v.v2.outbuffer);
6363 * See if that was the last channel left open.
6364 * (This is only our termination condition if we're
6365 * not running in -N mode.)
6367 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6369 * We used to send SSH_MSG_DISCONNECT here,
6370 * because I'd believed that _every_ conforming
6371 * SSH-2 connection had to end with a disconnect
6372 * being sent by at least one side; apparently
6373 * I was wrong and it's perfectly OK to
6374 * unceremoniously slam the connection shut
6375 * when you're done, and indeed OpenSSH feels
6376 * this is more polite than sending a
6377 * DISCONNECT. So now we don't.
6379 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6383 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6385 unsigned i = ssh_pkt_getuint32(pktin);
6386 struct ssh_channel *c;
6387 struct Packet *pktout;
6389 c = find234(ssh->channels, &i, ssh_channelfind);
6391 return; /* nonexistent channel */
6392 if (c->type != CHAN_SOCKDATA_DORMANT)
6393 return; /* dunno why they're confirming this */
6394 c->remoteid = ssh_pkt_getuint32(pktin);
6395 c->halfopen = FALSE;
6396 c->type = CHAN_SOCKDATA;
6397 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6398 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6400 pfd_confirm(c->u.pfd.s);
6403 * We have a pending close on this channel,
6404 * which we decided on before the server acked
6405 * the channel open. So now we know the
6406 * remoteid, we can close it again.
6408 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6409 ssh2_pkt_adduint32(pktout, c->remoteid);
6410 ssh2_pkt_send(ssh, pktout);
6414 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6416 static const char *const reasons[] = {
6417 "<unknown reason code>",
6418 "Administratively prohibited",
6420 "Unknown channel type",
6421 "Resource shortage",
6423 unsigned i = ssh_pkt_getuint32(pktin);
6424 unsigned reason_code;
6425 char *reason_string;
6427 struct ssh_channel *c;
6428 c = find234(ssh->channels, &i, ssh_channelfind);
6430 return; /* nonexistent channel */
6431 if (c->type != CHAN_SOCKDATA_DORMANT)
6432 return; /* dunno why they're failing this */
6434 reason_code = ssh_pkt_getuint32(pktin);
6435 if (reason_code >= lenof(reasons))
6436 reason_code = 0; /* ensure reasons[reason_code] in range */
6437 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6438 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6439 reasons[reason_code], reason_length, reason_string);
6441 pfd_close(c->u.pfd.s);
6443 del234(ssh->channels, c);
6447 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6451 int typelen, want_reply;
6452 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6453 struct ssh_channel *c;
6454 struct Packet *pktout;
6456 localid = ssh_pkt_getuint32(pktin);
6457 ssh_pkt_getstring(pktin, &type, &typelen);
6458 want_reply = ssh2_pkt_getbool(pktin);
6461 * First, check that the channel exists. Otherwise,
6462 * we can instantly disconnect with a rude message.
6464 c = find234(ssh->channels, &localid, ssh_channelfind);
6466 char *buf = dupprintf("Received channel request for nonexistent"
6467 " channel %d", localid);
6468 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6474 * Having got the channel number, we now look at
6475 * the request type string to see if it's something
6478 if (c == ssh->mainchan) {
6480 * We recognise "exit-status" and "exit-signal" on
6481 * the primary channel.
6483 if (typelen == 11 &&
6484 !memcmp(type, "exit-status", 11)) {
6486 ssh->exitcode = ssh_pkt_getuint32(pktin);
6487 logeventf(ssh, "Server sent command exit status %d",
6489 reply = SSH2_MSG_CHANNEL_SUCCESS;
6491 } else if (typelen == 11 &&
6492 !memcmp(type, "exit-signal", 11)) {
6494 int is_plausible = TRUE, is_int = FALSE;
6495 char *fmt_sig = "", *fmt_msg = "";
6497 int msglen = 0, core = FALSE;
6498 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6499 * provide an `int' for the signal, despite its
6500 * having been a `string' in the drafts since at
6501 * least 2001. (Fixed in session.c 1.147.) Try to
6502 * infer which we can safely parse it as. */
6504 unsigned char *p = pktin->body +
6506 long len = pktin->length - pktin->savedpos;
6507 unsigned long num = GET_32BIT(p); /* what is it? */
6508 /* If it's 0, it hardly matters; assume string */
6512 int maybe_int = FALSE, maybe_str = FALSE;
6513 #define CHECK_HYPOTHESIS(offset, result) \
6516 if (q >= 0 && q+4 <= len) { \
6517 q = q + 4 + GET_32BIT(p+q); \
6518 if (q >= 0 && q+4 <= len && \
6519 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6523 CHECK_HYPOTHESIS(4+1, maybe_int);
6524 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6525 #undef CHECK_HYPOTHESIS
6526 if (maybe_int && !maybe_str)
6528 else if (!maybe_int && maybe_str)
6531 /* Crikey. Either or neither. Panic. */
6532 is_plausible = FALSE;
6535 ssh->exitcode = 128; /* means `unknown signal' */
6538 /* Old non-standard OpenSSH. */
6539 int signum = ssh_pkt_getuint32(pktin);
6540 fmt_sig = dupprintf(" %d", signum);
6541 ssh->exitcode = 128 + signum;
6543 /* As per the drafts. */
6546 ssh_pkt_getstring(pktin, &sig, &siglen);
6547 /* Signal name isn't supposed to be blank, but
6548 * let's cope gracefully if it is. */
6550 fmt_sig = dupprintf(" \"%.*s\"",
6555 * Really hideous method of translating the
6556 * signal description back into a locally
6557 * meaningful number.
6562 #define TRANSLATE_SIGNAL(s) \
6563 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
6564 ssh->exitcode = 128 + SIG ## s
6566 TRANSLATE_SIGNAL(ABRT);
6569 TRANSLATE_SIGNAL(ALRM);
6572 TRANSLATE_SIGNAL(FPE);
6575 TRANSLATE_SIGNAL(HUP);
6578 TRANSLATE_SIGNAL(ILL);
6581 TRANSLATE_SIGNAL(INT);
6584 TRANSLATE_SIGNAL(KILL);
6587 TRANSLATE_SIGNAL(PIPE);
6590 TRANSLATE_SIGNAL(QUIT);
6593 TRANSLATE_SIGNAL(SEGV);
6596 TRANSLATE_SIGNAL(TERM);
6599 TRANSLATE_SIGNAL(USR1);
6602 TRANSLATE_SIGNAL(USR2);
6604 #undef TRANSLATE_SIGNAL
6606 ssh->exitcode = 128;
6608 core = ssh2_pkt_getbool(pktin);
6609 ssh_pkt_getstring(pktin, &msg, &msglen);
6611 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6613 /* ignore lang tag */
6614 } /* else don't attempt to parse */
6615 logeventf(ssh, "Server exited on signal%s%s%s",
6616 fmt_sig, core ? " (core dumped)" : "",
6618 if (*fmt_sig) sfree(fmt_sig);
6619 if (*fmt_msg) sfree(fmt_msg);
6620 reply = SSH2_MSG_CHANNEL_SUCCESS;
6625 * This is a channel request we don't know
6626 * about, so we now either ignore the request
6627 * or respond with CHANNEL_FAILURE, depending
6630 reply = SSH2_MSG_CHANNEL_FAILURE;
6633 pktout = ssh2_pkt_init(reply);
6634 ssh2_pkt_adduint32(pktout, c->remoteid);
6635 ssh2_pkt_send(ssh, pktout);
6639 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6642 int typelen, want_reply;
6643 struct Packet *pktout;
6645 ssh_pkt_getstring(pktin, &type, &typelen);
6646 want_reply = ssh2_pkt_getbool(pktin);
6649 * We currently don't support any global requests
6650 * at all, so we either ignore the request or
6651 * respond with REQUEST_FAILURE, depending on
6655 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6656 ssh2_pkt_send(ssh, pktout);
6660 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6668 struct ssh_channel *c;
6669 unsigned remid, winsize, pktsize;
6670 struct Packet *pktout;
6672 ssh_pkt_getstring(pktin, &type, &typelen);
6673 c = snew(struct ssh_channel);
6676 remid = ssh_pkt_getuint32(pktin);
6677 winsize = ssh_pkt_getuint32(pktin);
6678 pktsize = ssh_pkt_getuint32(pktin);
6680 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6683 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6684 addrstr = snewn(peeraddrlen+1, char);
6685 memcpy(addrstr, peeraddr, peeraddrlen);
6686 addrstr[peeraddrlen] = '\0';
6687 peerport = ssh_pkt_getuint32(pktin);
6689 logeventf(ssh, "Received X11 connect request from %s:%d",
6692 if (!ssh->X11_fwd_enabled)
6693 error = "X11 forwarding is not enabled";
6694 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6695 ssh->x11auth, addrstr, peerport,
6696 &ssh->cfg) != NULL) {
6697 error = "Unable to open an X11 connection";
6699 logevent("Opening X11 forward connection succeeded");
6704 } else if (typelen == 15 &&
6705 !memcmp(type, "forwarded-tcpip", 15)) {
6706 struct ssh_rportfwd pf, *realpf;
6709 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6710 pf.sport = ssh_pkt_getuint32(pktin);
6711 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6712 peerport = ssh_pkt_getuint32(pktin);
6713 realpf = find234(ssh->rportfwds, &pf, NULL);
6714 logeventf(ssh, "Received remote port %d open request "
6715 "from %s:%d", pf.sport, peeraddr, peerport);
6716 if (realpf == NULL) {
6717 error = "Remote port is not recognised";
6719 const char *e = pfd_newconnect(&c->u.pfd.s,
6723 realpf->pfrec->addressfamily);
6724 logeventf(ssh, "Attempting to forward remote port to "
6725 "%s:%d", realpf->dhost, realpf->dport);
6727 logeventf(ssh, "Port open failed: %s", e);
6728 error = "Port open failed";
6730 logevent("Forwarded port opened successfully");
6731 c->type = CHAN_SOCKDATA;
6734 } else if (typelen == 22 &&
6735 !memcmp(type, "auth-agent@openssh.com", 22)) {
6736 if (!ssh->agentfwd_enabled)
6737 error = "Agent forwarding is not enabled";
6739 c->type = CHAN_AGENT; /* identify channel type */
6740 c->u.a.lensofar = 0;
6743 error = "Unsupported channel type requested";
6746 c->remoteid = remid;
6747 c->halfopen = FALSE;
6749 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6750 ssh2_pkt_adduint32(pktout, c->remoteid);
6751 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6752 ssh2_pkt_addstring(pktout, error);
6753 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6754 ssh2_pkt_send(ssh, pktout);
6755 logeventf(ssh, "Rejected channel open: %s", error);
6758 c->localid = alloc_channel_id(ssh);
6760 c->v.v2.locwindow = OUR_V2_WINSIZE;
6761 c->v.v2.remwindow = winsize;
6762 c->v.v2.remmaxpkt = pktsize;
6763 bufchain_init(&c->v.v2.outbuffer);
6764 add234(ssh->channels, c);
6765 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6766 ssh2_pkt_adduint32(pktout, c->remoteid);
6767 ssh2_pkt_adduint32(pktout, c->localid);
6768 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6769 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6770 ssh2_pkt_send(ssh, pktout);
6775 * Buffer banner messages for later display at some convenient point.
6777 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6779 /* Arbitrary limit to prevent unbounded inflation of buffer */
6780 if (bufchain_size(&ssh->banner) <= 131072) {
6781 char *banner = NULL;
6783 ssh_pkt_getstring(pktin, &banner, &size);
6785 bufchain_add(&ssh->banner, banner, size);
6789 /* Helper function to deal with sending tty modes for "pty-req" */
6790 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6792 struct Packet *pktout = (struct Packet *)data;
6794 unsigned int arg = 0;
6795 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6796 if (i == lenof(ssh_ttymodes)) return;
6797 switch (ssh_ttymodes[i].type) {
6799 arg = ssh_tty_parse_specchar(val);
6802 arg = ssh_tty_parse_boolean(val);
6805 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6806 ssh2_pkt_adduint32(pktout, arg);
6810 * Handle the SSH-2 userauth and connection layers.
6812 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6813 struct Packet *pktin)
6815 struct do_ssh2_authconn_state {
6818 AUTH_TYPE_PUBLICKEY,
6819 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6820 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6822 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6823 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6825 int done_service_req;
6826 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6827 int tried_pubkey_config, done_agent;
6828 int kbd_inter_refused;
6830 prompts_t *cur_prompt;
6835 void *publickey_blob;
6836 int publickey_bloblen;
6837 int publickey_encrypted;
6838 char *publickey_algorithm;
6839 char *publickey_comment;
6840 unsigned char agent_request[5], *agent_response, *agentp;
6841 int agent_responselen;
6842 unsigned char *pkblob_in_agent;
6844 char *pkblob, *alg, *commentp;
6845 int pklen, alglen, commentlen;
6846 int siglen, retlen, len;
6847 char *q, *agentreq, *ret;
6849 int num_env, env_left, env_ok;
6850 struct Packet *pktout;
6852 crState(do_ssh2_authconn_state);
6854 crBegin(ssh->do_ssh2_authconn_crstate);
6856 s->done_service_req = FALSE;
6857 s->we_are_in = FALSE;
6858 if (!ssh->cfg.ssh_no_userauth) {
6860 * Request userauth protocol, and await a response to it.
6862 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6863 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6864 ssh2_pkt_send(ssh, s->pktout);
6865 crWaitUntilV(pktin);
6866 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6867 s->done_service_req = TRUE;
6869 if (!s->done_service_req) {
6871 * Request connection protocol directly, without authentication.
6873 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6874 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6875 ssh2_pkt_send(ssh, s->pktout);
6876 crWaitUntilV(pktin);
6877 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6878 s->we_are_in = TRUE; /* no auth required */
6880 bombout(("Server refused service request"));
6885 /* Arrange to be able to deal with any BANNERs that come in.
6886 * (We do this now as packets may come in during the next bit.) */
6887 bufchain_init(&ssh->banner);
6888 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6889 ssh2_msg_userauth_banner;
6892 * Misc one-time setup for authentication.
6894 s->publickey_blob = NULL;
6895 if (!s->we_are_in) {
6898 * Load the public half of any configured public key file
6901 if (!filename_is_null(ssh->cfg.keyfile)) {
6903 logeventf(ssh, "Reading private key file \"%.150s\"",
6904 filename_to_str(&ssh->cfg.keyfile));
6905 keytype = key_type(&ssh->cfg.keyfile);
6906 if (keytype == SSH_KEYTYPE_SSH2) {
6909 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6910 &s->publickey_algorithm,
6911 &s->publickey_bloblen,
6912 &s->publickey_comment, &error);
6913 if (s->publickey_blob) {
6914 s->publickey_encrypted =
6915 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
6918 logeventf(ssh, "Unable to load private key (%s)",
6920 msgbuf = dupprintf("Unable to load private key file "
6921 "\"%.150s\" (%s)\r\n",
6922 filename_to_str(&ssh->cfg.keyfile),
6924 c_write_str(ssh, msgbuf);
6929 logeventf(ssh, "Unable to use this key file (%s)",
6930 key_type_to_str(keytype));
6931 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6933 filename_to_str(&ssh->cfg.keyfile),
6934 key_type_to_str(keytype));
6935 c_write_str(ssh, msgbuf);
6937 s->publickey_blob = NULL;
6942 * Find out about any keys Pageant has (but if there's a
6943 * public key configured, filter out all others).
6946 s->agent_response = NULL;
6947 s->pkblob_in_agent = NULL;
6948 if (ssh->cfg.tryagent && agent_exists()) {
6952 logevent("Pageant is running. Requesting keys.");
6954 /* Request the keys held by the agent. */
6955 PUT_32BIT(s->agent_request, 1);
6956 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6957 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
6958 ssh_agent_callback, ssh)) {
6962 bombout(("Unexpected data from server while"
6963 " waiting for agent response"));
6966 } while (pktin || inlen > 0);
6967 r = ssh->agent_response;
6968 s->agent_responselen = ssh->agent_response_len;
6970 s->agent_response = (unsigned char *) r;
6971 if (s->agent_response && s->agent_responselen >= 5 &&
6972 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6975 p = s->agent_response + 5;
6976 s->nkeys = GET_32BIT(p);
6978 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6979 if (s->publickey_blob) {
6980 /* See if configured key is in agent. */
6981 for (keyi = 0; keyi < s->nkeys; keyi++) {
6982 s->pklen = GET_32BIT(p);
6983 if (s->pklen == s->publickey_bloblen &&
6984 !memcmp(p+4, s->publickey_blob,
6985 s->publickey_bloblen)) {
6986 logeventf(ssh, "Pageant key #%d matches "
6987 "configured key file", keyi);
6989 s->pkblob_in_agent = p;
6993 p += GET_32BIT(p) + 4; /* comment */
6995 if (!s->pkblob_in_agent) {
6996 logevent("Configured key file not in Pageant");
7006 * We repeat this whole loop, including the username prompt,
7007 * until we manage a successful authentication. If the user
7008 * types the wrong _password_, they can be sent back to the
7009 * beginning to try another username, if this is configured on.
7010 * (If they specify a username in the config, they are never
7011 * asked, even if they do give a wrong password.)
7013 * I think this best serves the needs of
7015 * - the people who have no configuration, no keys, and just
7016 * want to try repeated (username,password) pairs until they
7017 * type both correctly
7019 * - people who have keys and configuration but occasionally
7020 * need to fall back to passwords
7022 * - people with a key held in Pageant, who might not have
7023 * logged in to a particular machine before; so they want to
7024 * type a username, and then _either_ their key will be
7025 * accepted, _or_ they will type a password. If they mistype
7026 * the username they will want to be able to get back and
7029 s->username[0] = '\0';
7030 s->got_username = FALSE;
7031 while (!s->we_are_in) {
7035 if (s->got_username && !ssh->cfg.change_username) {
7037 * We got a username last time round this loop, and
7038 * with change_username turned off we don't try to get
7041 } else if (!*ssh->cfg.username) {
7042 int ret; /* need not be kept over crReturn */
7043 s->cur_prompt = new_prompts(ssh->frontend);
7044 s->cur_prompt->to_server = TRUE;
7045 s->cur_prompt->name = dupstr("SSH login name");
7046 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
7047 lenof(s->username));
7048 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7051 crWaitUntilV(!pktin);
7052 ret = get_userpass_input(s->cur_prompt, in, inlen);
7057 * get_userpass_input() failed to get a username.
7060 free_prompts(s->cur_prompt);
7061 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7064 memcpy(s->username, s->cur_prompt->prompts[0]->result,
7065 lenof(s->username));
7066 free_prompts(s->cur_prompt);
7069 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
7070 s->username[sizeof(s->username)-1] = '\0';
7071 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7072 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
7073 c_write_str(ssh, stuff);
7077 s->got_username = TRUE;
7080 * Send an authentication request using method "none": (a)
7081 * just in case it succeeds, and (b) so that we know what
7082 * authentication methods we can usefully try next.
7084 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7086 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7087 ssh2_pkt_addstring(s->pktout, s->username);
7088 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7089 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7090 ssh2_pkt_send(ssh, s->pktout);
7091 s->type = AUTH_TYPE_NONE;
7093 s->we_are_in = FALSE;
7095 s->tried_pubkey_config = FALSE;
7096 s->kbd_inter_refused = FALSE;
7098 /* Reset agent request state. */
7099 s->done_agent = FALSE;
7100 if (s->agent_response) {
7101 if (s->pkblob_in_agent) {
7102 s->agentp = s->pkblob_in_agent;
7104 s->agentp = s->agent_response + 5 + 4;
7111 * Wait for the result of the last authentication request.
7114 crWaitUntilV(pktin);
7116 * Now is a convenient point to spew any banner material
7117 * that we've accumulated. (This should ensure that when
7118 * we exit the auth loop, we haven't any left to deal
7122 int size = bufchain_size(&ssh->banner);
7124 * Don't show the banner if we're operating in
7125 * non-verbose non-interactive mode. (It's probably
7126 * a script, which means nobody will read the
7127 * banner _anyway_, and moreover the printing of
7128 * the banner will screw up processing on the
7129 * output of (say) plink.)
7131 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7132 char *banner = snewn(size, char);
7133 bufchain_fetch(&ssh->banner, banner, size);
7134 c_write_untrusted(ssh, banner, size);
7137 bufchain_clear(&ssh->banner);
7139 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
7140 logevent("Access granted");
7141 s->we_are_in = TRUE;
7145 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
7146 bombout(("Strange packet received during authentication: "
7147 "type %d", pktin->type));
7154 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7155 * we can look at the string in it and know what we can
7156 * helpfully try next.
7158 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
7161 ssh_pkt_getstring(pktin, &methods, &methlen);
7162 if (!ssh2_pkt_getbool(pktin)) {
7164 * We have received an unequivocal Access
7165 * Denied. This can translate to a variety of
7168 * - if we'd just tried "none" authentication,
7169 * it's not worth printing anything at all
7171 * - if we'd just tried a public key _offer_,
7172 * the message should be "Server refused our
7173 * key" (or no message at all if the key
7174 * came from Pageant)
7176 * - if we'd just tried anything else, the
7177 * message really should be "Access denied".
7179 * Additionally, if we'd just tried password
7180 * authentication, we should break out of this
7181 * whole loop so as to go back to the username
7182 * prompt (iff we're configured to allow
7183 * username change attempts).
7185 if (s->type == AUTH_TYPE_NONE) {
7187 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7188 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7189 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7190 c_write_str(ssh, "Server refused our key\r\n");
7191 logevent("Server refused public key");
7192 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
7193 /* server declined keyboard-interactive; ignore */
7195 c_write_str(ssh, "Access denied\r\n");
7196 logevent("Access denied");
7197 if (s->type == AUTH_TYPE_PASSWORD &&
7198 ssh->cfg.change_username) {
7199 /* XXX perhaps we should allow
7200 * keyboard-interactive to do this too? */
7201 s->we_are_in = FALSE;
7206 c_write_str(ssh, "Further authentication required\r\n");
7207 logevent("Further authentication required");
7211 in_commasep_string("publickey", methods, methlen);
7213 in_commasep_string("password", methods, methlen);
7214 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
7215 in_commasep_string("keyboard-interactive", methods, methlen);
7218 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7220 if (s->can_pubkey && !s->done_agent && s->nkeys) {
7223 * Attempt public-key authentication using a key from Pageant.
7226 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7228 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7230 /* Unpack key from agent response */
7231 s->pklen = GET_32BIT(s->agentp);
7233 s->pkblob = (char *)s->agentp;
7234 s->agentp += s->pklen;
7235 s->alglen = GET_32BIT(s->pkblob);
7236 s->alg = s->pkblob + 4;
7237 s->commentlen = GET_32BIT(s->agentp);
7239 s->commentp = (char *)s->agentp;
7240 s->agentp += s->commentlen;
7241 /* s->agentp now points at next key, if any */
7243 /* See if server will accept it */
7244 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7245 ssh2_pkt_addstring(s->pktout, s->username);
7246 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7247 /* service requested */
7248 ssh2_pkt_addstring(s->pktout, "publickey");
7250 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7251 ssh2_pkt_addstring_start(s->pktout);
7252 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7253 ssh2_pkt_addstring_start(s->pktout);
7254 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7255 ssh2_pkt_send(ssh, s->pktout);
7256 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
7258 crWaitUntilV(pktin);
7259 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7261 /* Offer of key refused. */
7268 if (flags & FLAG_VERBOSE) {
7269 c_write_str(ssh, "Authenticating with "
7271 c_write(ssh, s->commentp, s->commentlen);
7272 c_write_str(ssh, "\" from agent\r\n");
7276 * Server is willing to accept the key.
7277 * Construct a SIGN_REQUEST.
7279 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7280 ssh2_pkt_addstring(s->pktout, s->username);
7281 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7282 /* service requested */
7283 ssh2_pkt_addstring(s->pktout, "publickey");
7285 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7286 ssh2_pkt_addstring_start(s->pktout);
7287 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7288 ssh2_pkt_addstring_start(s->pktout);
7289 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7291 /* Ask agent for signature. */
7292 s->siglen = s->pktout->length - 5 + 4 +
7293 ssh->v2_session_id_len;
7294 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7296 s->len = 1; /* message type */
7297 s->len += 4 + s->pklen; /* key blob */
7298 s->len += 4 + s->siglen; /* data to sign */
7299 s->len += 4; /* flags */
7300 s->agentreq = snewn(4 + s->len, char);
7301 PUT_32BIT(s->agentreq, s->len);
7302 s->q = s->agentreq + 4;
7303 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
7304 PUT_32BIT(s->q, s->pklen);
7306 memcpy(s->q, s->pkblob, s->pklen);
7308 PUT_32BIT(s->q, s->siglen);
7310 /* Now the data to be signed... */
7311 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7312 PUT_32BIT(s->q, ssh->v2_session_id_len);
7315 memcpy(s->q, ssh->v2_session_id,
7316 ssh->v2_session_id_len);
7317 s->q += ssh->v2_session_id_len;
7318 memcpy(s->q, s->pktout->data + 5,
7319 s->pktout->length - 5);
7320 s->q += s->pktout->length - 5;
7321 /* And finally the (zero) flags word. */
7323 if (!agent_query(s->agentreq, s->len + 4,
7325 ssh_agent_callback, ssh)) {
7329 bombout(("Unexpected data from server"
7330 " while waiting for agent"
7334 } while (pktin || inlen > 0);
7335 vret = ssh->agent_response;
7336 s->retlen = ssh->agent_response_len;
7341 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7342 logevent("Sending Pageant's response");
7343 ssh2_add_sigblob(ssh, s->pktout,
7344 s->pkblob, s->pklen,
7346 GET_32BIT(s->ret + 5));
7347 ssh2_pkt_send(ssh, s->pktout);
7348 s->type = AUTH_TYPE_PUBLICKEY;
7350 /* FIXME: less drastic response */
7351 bombout(("Pageant failed to answer challenge"));
7357 /* Do we have any keys left to try? */
7358 if (s->pkblob_in_agent) {
7359 s->done_agent = TRUE;
7360 s->tried_pubkey_config = TRUE;
7363 if (s->keyi >= s->nkeys)
7364 s->done_agent = TRUE;
7367 } else if (s->can_pubkey && s->publickey_blob &&
7368 !s->tried_pubkey_config) {
7370 struct ssh2_userkey *key; /* not live over crReturn */
7371 char *passphrase; /* not live over crReturn */
7373 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7375 s->tried_pubkey_config = TRUE;
7378 * Try the public key supplied in the configuration.
7380 * First, offer the public blob to see if the server is
7381 * willing to accept it.
7383 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7384 ssh2_pkt_addstring(s->pktout, s->username);
7385 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7386 /* service requested */
7387 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7388 ssh2_pkt_addbool(s->pktout, FALSE);
7389 /* no signature included */
7390 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7391 ssh2_pkt_addstring_start(s->pktout);
7392 ssh2_pkt_addstring_data(s->pktout,
7393 (char *)s->publickey_blob,
7394 s->publickey_bloblen);
7395 ssh2_pkt_send(ssh, s->pktout);
7396 logevent("Offered public key");
7398 crWaitUntilV(pktin);
7399 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7400 /* Key refused. Give up. */
7401 s->gotit = TRUE; /* reconsider message next loop */
7402 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7403 continue; /* process this new message */
7405 logevent("Offer of public key accepted");
7408 * Actually attempt a serious authentication using
7411 if (flags & FLAG_VERBOSE) {
7412 c_write_str(ssh, "Authenticating with public key \"");
7413 c_write_str(ssh, s->publickey_comment);
7414 c_write_str(ssh, "\"\r\n");
7418 const char *error; /* not live over crReturn */
7419 if (s->publickey_encrypted) {
7421 * Get a passphrase from the user.
7423 int ret; /* need not be kept over crReturn */
7424 s->cur_prompt = new_prompts(ssh->frontend);
7425 s->cur_prompt->to_server = FALSE;
7426 s->cur_prompt->name = dupstr("SSH key passphrase");
7427 add_prompt(s->cur_prompt,
7428 dupprintf("Passphrase for key \"%.100s\": ",
7429 s->publickey_comment),
7430 FALSE, SSH_MAX_PASSWORD_LEN);
7431 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7434 crWaitUntilV(!pktin);
7435 ret = get_userpass_input(s->cur_prompt,
7440 /* Failed to get a passphrase. Terminate. */
7441 free_prompts(s->cur_prompt);
7442 ssh_disconnect(ssh, NULL,
7443 "Unable to authenticate",
7444 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7449 dupstr(s->cur_prompt->prompts[0]->result);
7450 free_prompts(s->cur_prompt);
7452 passphrase = NULL; /* no passphrase needed */
7456 * Try decrypting the key.
7458 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7461 /* burn the evidence */
7462 memset(passphrase, 0, strlen(passphrase));
7465 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7467 (key == SSH2_WRONG_PASSPHRASE)) {
7468 c_write_str(ssh, "Wrong passphrase\r\n");
7470 /* and loop again */
7472 c_write_str(ssh, "Unable to load private key (");
7473 c_write_str(ssh, error);
7474 c_write_str(ssh, ")\r\n");
7476 break; /* try something else */
7482 unsigned char *pkblob, *sigblob, *sigdata;
7483 int pkblob_len, sigblob_len, sigdata_len;
7487 * We have loaded the private key and the server
7488 * has announced that it's willing to accept it.
7489 * Hallelujah. Generate a signature and send it.
7491 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7492 ssh2_pkt_addstring(s->pktout, s->username);
7493 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7494 /* service requested */
7495 ssh2_pkt_addstring(s->pktout, "publickey");
7497 ssh2_pkt_addbool(s->pktout, TRUE);
7498 /* signature follows */
7499 ssh2_pkt_addstring(s->pktout, key->alg->name);
7500 pkblob = key->alg->public_blob(key->data,
7502 ssh2_pkt_addstring_start(s->pktout);
7503 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7507 * The data to be signed is:
7511 * followed by everything so far placed in the
7514 sigdata_len = s->pktout->length - 5 + 4 +
7515 ssh->v2_session_id_len;
7516 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7518 sigdata = snewn(sigdata_len, unsigned char);
7520 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7521 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7524 memcpy(sigdata+p, ssh->v2_session_id,
7525 ssh->v2_session_id_len);
7526 p += ssh->v2_session_id_len;
7527 memcpy(sigdata+p, s->pktout->data + 5,
7528 s->pktout->length - 5);
7529 p += s->pktout->length - 5;
7530 assert(p == sigdata_len);
7531 sigblob = key->alg->sign(key->data, (char *)sigdata,
7532 sigdata_len, &sigblob_len);
7533 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7534 sigblob, sigblob_len);
7539 ssh2_pkt_send(ssh, s->pktout);
7540 s->type = AUTH_TYPE_PUBLICKEY;
7541 key->alg->freekey(key->data);
7544 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
7547 * Keyboard-interactive authentication.
7550 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7552 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
7554 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7555 ssh2_pkt_addstring(s->pktout, s->username);
7556 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7557 /* service requested */
7558 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
7560 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7561 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
7562 ssh2_pkt_send(ssh, s->pktout);
7564 crWaitUntilV(pktin);
7565 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7566 /* Server is not willing to do keyboard-interactive
7567 * at all (or, bizarrely but legally, accepts the
7568 * user without actually issuing any prompts).
7569 * Give up on it entirely. */
7571 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7572 logevent("Keyboard-interactive authentication refused");
7573 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7574 s->kbd_inter_refused = TRUE; /* don't try it again */
7579 * Loop while the server continues to send INFO_REQUESTs.
7581 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
7583 char *name, *inst, *lang;
7584 int name_len, inst_len, lang_len;
7588 * We've got a fresh USERAUTH_INFO_REQUEST.
7589 * Get the preamble and start building a prompt.
7591 ssh_pkt_getstring(pktin, &name, &name_len);
7592 ssh_pkt_getstring(pktin, &inst, &inst_len);
7593 ssh_pkt_getstring(pktin, &lang, &lang_len);
7594 s->cur_prompt = new_prompts(ssh->frontend);
7595 s->cur_prompt->to_server = TRUE;
7597 /* FIXME: better prefix to distinguish from
7599 s->cur_prompt->name =
7600 dupprintf("SSH server: %.*s", name_len, name);
7601 s->cur_prompt->name_reqd = TRUE;
7603 s->cur_prompt->name =
7604 dupstr("SSH server authentication");
7605 s->cur_prompt->name_reqd = FALSE;
7607 /* FIXME: ugly to print "Using..." in prompt _every_
7608 * time round. Can this be done more subtly? */
7609 s->cur_prompt->instruction =
7610 dupprintf("Using keyboard-interactive authentication.%s%.*s",
7611 inst_len ? "\n" : "", inst_len, inst);
7612 s->cur_prompt->instr_reqd = TRUE;
7615 * Get the prompts from the packet.
7617 s->num_prompts = ssh_pkt_getuint32(pktin);
7618 for (i = 0; i < s->num_prompts; i++) {
7622 static char noprompt[] =
7623 "<server failed to send prompt>: ";
7625 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7626 echo = ssh2_pkt_getbool(pktin);
7629 prompt_len = lenof(noprompt)-1;
7631 add_prompt(s->cur_prompt,
7632 dupprintf("%.*s", prompt_len, prompt),
7633 echo, SSH_MAX_PASSWORD_LEN);
7637 * Get the user's responses.
7639 if (s->num_prompts) {
7640 int ret; /* not live over crReturn */
7641 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7644 crWaitUntilV(!pktin);
7645 ret = get_userpass_input(s->cur_prompt, in, inlen);
7650 * Failed to get responses. Terminate.
7652 free_prompts(s->cur_prompt);
7653 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7654 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7661 * Send the responses to the server.
7663 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7664 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7665 for (i=0; i < s->num_prompts; i++) {
7666 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7667 ssh2_pkt_addstring(s->pktout,
7668 s->cur_prompt->prompts[i]->result);
7669 end_log_omission(ssh, s->pktout);
7671 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7674 * Get the next packet in case it's another
7677 crWaitUntilV(pktin);
7682 * We should have SUCCESS or FAILURE now.
7686 } else if (s->can_passwd) {
7689 * Plain old password authentication.
7691 int ret; /* not live over crReturn */
7692 int changereq_first_time; /* not live over crReturn */
7694 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
7696 s->cur_prompt = new_prompts(ssh->frontend);
7697 s->cur_prompt->to_server = TRUE;
7698 s->cur_prompt->name = dupstr("SSH password");
7699 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
7702 FALSE, SSH_MAX_PASSWORD_LEN);
7704 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7707 crWaitUntilV(!pktin);
7708 ret = get_userpass_input(s->cur_prompt, in, inlen);
7713 * Failed to get responses. Terminate.
7715 free_prompts(s->cur_prompt);
7716 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7717 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7722 * Squirrel away the password. (We may need it later if
7723 * asked to change it.)
7725 s->password = dupstr(s->cur_prompt->prompts[0]->result);
7726 free_prompts(s->cur_prompt);
7729 * Send the password packet.
7731 * We pad out the password packet to 256 bytes to make
7732 * it harder for an attacker to find the length of the
7735 * Anyone using a password longer than 256 bytes
7736 * probably doesn't have much to worry about from
7737 * people who find out how long their password is!
7739 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7740 ssh2_pkt_addstring(s->pktout, s->username);
7741 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7742 /* service requested */
7743 ssh2_pkt_addstring(s->pktout, "password");
7744 ssh2_pkt_addbool(s->pktout, FALSE);
7745 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7746 ssh2_pkt_addstring(s->pktout, s->password);
7747 end_log_omission(ssh, s->pktout);
7748 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7749 logevent("Sent password");
7750 s->type = AUTH_TYPE_PASSWORD;
7753 * Wait for next packet, in case it's a password change
7756 crWaitUntilV(pktin);
7757 changereq_first_time = TRUE;
7759 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
7762 * We're being asked for a new password
7763 * (perhaps not for the first time).
7764 * Loop until the server accepts it.
7767 int got_new = FALSE; /* not live over crReturn */
7768 char *prompt; /* not live over crReturn */
7769 int prompt_len; /* not live over crReturn */
7773 if (changereq_first_time)
7774 msg = "Server requested password change";
7776 msg = "Server rejected new password";
7778 c_write_str(ssh, msg);
7779 c_write_str(ssh, "\r\n");
7782 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7784 s->cur_prompt = new_prompts(ssh->frontend);
7785 s->cur_prompt->to_server = TRUE;
7786 s->cur_prompt->name = dupstr("New SSH password");
7787 s->cur_prompt->instruction =
7788 dupprintf("%.*s", prompt_len, prompt);
7789 s->cur_prompt->instr_reqd = TRUE;
7791 * There's no explicit requirement in the protocol
7792 * for the "old" passwords in the original and
7793 * password-change messages to be the same, and
7794 * apparently some Cisco kit supports password change
7795 * by the user entering a blank password originally
7796 * and the real password subsequently, so,
7797 * reluctantly, we prompt for the old password again.
7799 * (On the other hand, some servers don't even bother
7800 * to check this field.)
7802 add_prompt(s->cur_prompt,
7803 dupstr("Current password (blank for previously entered password): "),
7804 FALSE, SSH_MAX_PASSWORD_LEN);
7805 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
7806 FALSE, SSH_MAX_PASSWORD_LEN);
7807 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
7808 FALSE, SSH_MAX_PASSWORD_LEN);
7811 * Loop until the user manages to enter the same
7816 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7819 crWaitUntilV(!pktin);
7820 ret = get_userpass_input(s->cur_prompt, in, inlen);
7825 * Failed to get responses. Terminate.
7827 /* burn the evidence */
7828 free_prompts(s->cur_prompt);
7829 memset(s->password, 0, strlen(s->password));
7831 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7832 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7838 * If the user specified a new original password
7839 * (IYSWIM), overwrite any previously specified
7841 * (A side effect is that the user doesn't have to
7842 * re-enter it if they louse up the new password.)
7844 if (s->cur_prompt->prompts[0]->result[0]) {
7845 memset(s->password, 0, strlen(s->password));
7846 /* burn the evidence */
7849 dupstr(s->cur_prompt->prompts[0]->result);
7853 * Check the two new passwords match.
7855 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
7856 s->cur_prompt->prompts[2]->result)
7859 /* They don't. Silly user. */
7860 c_write_str(ssh, "Passwords do not match\r\n");
7865 * Send the new password (along with the old one).
7866 * (see above for padding rationale)
7868 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7869 ssh2_pkt_addstring(s->pktout, s->username);
7870 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7871 /* service requested */
7872 ssh2_pkt_addstring(s->pktout, "password");
7873 ssh2_pkt_addbool(s->pktout, TRUE);
7874 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7875 ssh2_pkt_addstring(s->pktout, s->password);
7876 ssh2_pkt_addstring(s->pktout,
7877 s->cur_prompt->prompts[1]->result);
7878 free_prompts(s->cur_prompt);
7879 end_log_omission(ssh, s->pktout);
7880 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7881 logevent("Sent new password");
7884 * Now see what the server has to say about it.
7885 * (If it's CHANGEREQ again, it's not happy with the
7888 crWaitUntilV(pktin);
7889 changereq_first_time = FALSE;
7894 * We need to reexamine the current pktin at the top
7895 * of the loop. Either:
7896 * - we weren't asked to change password at all, in
7897 * which case it's a SUCCESS or FAILURE with the
7899 * - we sent a new password, and the server was
7900 * either OK with it (SUCCESS or FAILURE w/partial
7901 * success) or unhappy with the _old_ password
7902 * (FAILURE w/o partial success)
7903 * In any of these cases, we go back to the top of
7904 * the loop and start again.
7909 * We don't need the old password any more, in any
7910 * case. Burn the evidence.
7912 memset(s->password, 0, strlen(s->password));
7917 ssh_disconnect(ssh, NULL,
7918 "No supported authentication methods available",
7919 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7927 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7929 /* Clear up various bits and pieces from authentication. */
7930 if (s->publickey_blob) {
7931 sfree(s->publickey_blob);
7932 sfree(s->publickey_comment);
7934 if (s->agent_response)
7935 sfree(s->agent_response);
7938 * Now the connection protocol has started, one way or another.
7941 ssh->channels = newtree234(ssh_channelcmp);
7944 * Set up handlers for some connection protocol messages, so we
7945 * don't have to handle them repeatedly in this coroutine.
7947 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7948 ssh2_msg_channel_window_adjust;
7949 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7950 ssh2_msg_global_request;
7953 * Create the main session channel.
7955 if (ssh->cfg.ssh_no_shell) {
7956 ssh->mainchan = NULL;
7957 } else if (*ssh->cfg.ssh_nc_host) {
7959 * Just start a direct-tcpip channel and use it as the main
7962 ssh->mainchan = snew(struct ssh_channel);
7963 ssh->mainchan->ssh = ssh;
7964 ssh->mainchan->localid = alloc_channel_id(ssh);
7966 "Opening direct-tcpip channel to %s:%d in place of session",
7967 ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
7968 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7969 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
7970 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7971 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7972 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7973 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7974 ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
7975 ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
7977 * There's nothing meaningful to put in the originator
7978 * fields, but some servers insist on syntactically correct
7981 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
7982 ssh2_pkt_adduint32(s->pktout, 0);
7983 ssh2_pkt_send(ssh, s->pktout);
7985 crWaitUntilV(pktin);
7986 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7987 bombout(("Server refused to open a direct-tcpip channel"));
7989 /* FIXME: error data comes back in FAILURE packet */
7991 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7992 bombout(("Server's channel confirmation cited wrong channel"));
7995 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7996 ssh->mainchan->halfopen = FALSE;
7997 ssh->mainchan->type = CHAN_MAINSESSION;
7998 ssh->mainchan->closes = 0;
7999 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8000 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8001 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
8002 add234(ssh->channels, ssh->mainchan);
8003 update_specials_menu(ssh->frontend);
8004 logevent("Opened direct-tcpip channel");
8007 ssh->mainchan = snew(struct ssh_channel);
8008 ssh->mainchan->ssh = ssh;
8009 ssh->mainchan->localid = alloc_channel_id(ssh);
8010 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8011 ssh2_pkt_addstring(s->pktout, "session");
8012 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8013 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
8014 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8015 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8016 ssh2_pkt_send(ssh, s->pktout);
8017 crWaitUntilV(pktin);
8018 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8019 bombout(("Server refused to open a session"));
8021 /* FIXME: error data comes back in FAILURE packet */
8023 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8024 bombout(("Server's channel confirmation cited wrong channel"));
8027 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8028 ssh->mainchan->halfopen = FALSE;
8029 ssh->mainchan->type = CHAN_MAINSESSION;
8030 ssh->mainchan->closes = 0;
8031 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8032 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8033 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
8034 add234(ssh->channels, ssh->mainchan);
8035 update_specials_menu(ssh->frontend);
8036 logevent("Opened channel for session");
8037 ssh->ncmode = FALSE;
8041 * Now we have a channel, make dispatch table entries for
8042 * general channel-based messages.
8044 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8045 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8046 ssh2_msg_channel_data;
8047 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8048 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8049 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8050 ssh2_msg_channel_open_confirmation;
8051 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8052 ssh2_msg_channel_open_failure;
8053 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8054 ssh2_msg_channel_request;
8055 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8056 ssh2_msg_channel_open;
8059 * Potentially enable X11 forwarding.
8061 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward) {
8062 char proto[20], data[64];
8063 logevent("Requesting X11 forwarding");
8064 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
8065 data, sizeof(data), ssh->cfg.x11_auth);
8066 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
8067 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8068 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8069 ssh2_pkt_addstring(s->pktout, "x11-req");
8070 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8071 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8072 ssh2_pkt_addstring(s->pktout, proto);
8074 * Note that while we blank the X authentication data here, we don't
8075 * take any special action to blank the start of an X11 channel,
8076 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
8077 * without having session blanking enabled is likely to leak your
8078 * cookie into the log.
8080 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8081 ssh2_pkt_addstring(s->pktout, data);
8082 end_log_omission(ssh, s->pktout);
8083 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
8084 ssh2_pkt_send(ssh, s->pktout);
8086 crWaitUntilV(pktin);
8088 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8089 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8090 bombout(("Unexpected response to X11 forwarding request:"
8091 " packet type %d", pktin->type));
8094 logevent("X11 forwarding refused");
8096 logevent("X11 forwarding enabled");
8097 ssh->X11_fwd_enabled = TRUE;
8102 * Enable port forwardings.
8104 ssh_setup_portfwd(ssh, &ssh->cfg);
8107 * Potentially enable agent forwarding.
8109 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
8110 logevent("Requesting OpenSSH-style agent forwarding");
8111 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8112 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8113 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
8114 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8115 ssh2_pkt_send(ssh, s->pktout);
8117 crWaitUntilV(pktin);
8119 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8120 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8121 bombout(("Unexpected response to agent forwarding request:"
8122 " packet type %d", pktin->type));
8125 logevent("Agent forwarding refused");
8127 logevent("Agent forwarding enabled");
8128 ssh->agentfwd_enabled = TRUE;
8133 * Now allocate a pty for the session.
8135 if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
8136 /* Unpick the terminal-speed string. */
8137 /* XXX perhaps we should allow no speeds to be sent. */
8138 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8139 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
8140 /* Build the pty request. */
8141 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8142 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8143 ssh2_pkt_addstring(s->pktout, "pty-req");
8144 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8145 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
8146 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
8147 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
8148 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
8149 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
8150 ssh2_pkt_addstring_start(s->pktout);
8151 parse_ttymodes(ssh, ssh->cfg.ttymodes,
8152 ssh2_send_ttymode, (void *)s->pktout);
8153 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
8154 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
8155 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
8156 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
8157 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
8158 ssh2_pkt_send(ssh, s->pktout);
8159 ssh->state = SSH_STATE_INTERMED;
8161 crWaitUntilV(pktin);
8163 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8164 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8165 bombout(("Unexpected response to pty request:"
8166 " packet type %d", pktin->type));
8169 c_write_str(ssh, "Server refused to allocate pty\r\n");
8170 ssh->editing = ssh->echoing = 1;
8172 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8173 ssh->ospeed, ssh->ispeed);
8176 ssh->editing = ssh->echoing = 1;
8180 * Send environment variables.
8182 * Simplest thing here is to send all the requests at once, and
8183 * then wait for a whole bunch of successes or failures.
8185 if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
8186 char *e = ssh->cfg.environmt;
8187 char *var, *varend, *val;
8193 while (*e && *e != '\t') e++;
8195 if (*e == '\t') e++;
8200 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8201 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8202 ssh2_pkt_addstring(s->pktout, "env");
8203 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8204 ssh2_pkt_addstring_start(s->pktout);
8205 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
8206 ssh2_pkt_addstring(s->pktout, val);
8207 ssh2_pkt_send(ssh, s->pktout);
8212 logeventf(ssh, "Sent %d environment variables", s->num_env);
8215 s->env_left = s->num_env;
8217 while (s->env_left > 0) {
8218 crWaitUntilV(pktin);
8220 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8221 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8222 bombout(("Unexpected response to environment request:"
8223 " packet type %d", pktin->type));
8233 if (s->env_ok == s->num_env) {
8234 logevent("All environment variables successfully set");
8235 } else if (s->env_ok == 0) {
8236 logevent("All environment variables refused");
8237 c_write_str(ssh, "Server refused to set environment variables\r\n");
8239 logeventf(ssh, "%d environment variables refused",
8240 s->num_env - s->env_ok);
8241 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8246 * Start a shell or a remote command. We may have to attempt
8247 * this twice if the config data has provided a second choice
8250 if (ssh->mainchan && !ssh->ncmode) while (1) {
8254 if (ssh->fallback_cmd) {
8255 subsys = ssh->cfg.ssh_subsys2;
8256 cmd = ssh->cfg.remote_cmd_ptr2;
8258 subsys = ssh->cfg.ssh_subsys;
8259 cmd = ssh->cfg.remote_cmd_ptr;
8260 if (!cmd) cmd = ssh->cfg.remote_cmd;
8263 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8264 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8266 ssh2_pkt_addstring(s->pktout, "subsystem");
8267 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8268 ssh2_pkt_addstring(s->pktout, cmd);
8270 ssh2_pkt_addstring(s->pktout, "exec");
8271 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8272 ssh2_pkt_addstring(s->pktout, cmd);
8274 ssh2_pkt_addstring(s->pktout, "shell");
8275 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8277 ssh2_pkt_send(ssh, s->pktout);
8279 crWaitUntilV(pktin);
8281 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8282 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8283 bombout(("Unexpected response to shell/command request:"
8284 " packet type %d", pktin->type));
8288 * We failed to start the command. If this is the
8289 * fallback command, we really are finished; if it's
8290 * not, and if the fallback command exists, try falling
8291 * back to it before complaining.
8293 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
8294 logevent("Primary command failed; attempting fallback");
8295 ssh->fallback_cmd = TRUE;
8298 bombout(("Server refused to start a shell/command"));
8301 logevent("Started a shell/command");
8306 ssh->state = SSH_STATE_SESSION;
8307 if (ssh->size_needed)
8308 ssh_size(ssh, ssh->term_width, ssh->term_height);
8309 if (ssh->eof_needed)
8310 ssh_special(ssh, TS_EOF);
8316 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
8321 s->try_send = FALSE;
8325 * _All_ the connection-layer packets we expect to
8326 * receive are now handled by the dispatch table.
8327 * Anything that reaches here must be bogus.
8330 bombout(("Strange packet received: type %d", pktin->type));
8332 } else if (ssh->mainchan) {
8334 * We have spare data. Add it to the channel buffer.
8336 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
8341 struct ssh_channel *c;
8343 * Try to send data on all channels if we can.
8345 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
8346 ssh2_try_send_and_unthrottle(c);
8354 * Handlers for SSH-2 messages that might arrive at any moment.
8356 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
8358 /* log reason code in disconnect message */
8360 int nowlen, reason, msglen;
8362 reason = ssh_pkt_getuint32(pktin);
8363 ssh_pkt_getstring(pktin, &msg, &msglen);
8365 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
8366 buf = dupprintf("Received disconnect message (%s)",
8367 ssh2_disconnect_reasons[reason]);
8369 buf = dupprintf("Received disconnect message (unknown"
8370 " type %d)", reason);
8374 buf = dupprintf("Disconnection message text: %n%.*s",
8375 &nowlen, msglen, msg);
8377 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
8379 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
8380 ssh2_disconnect_reasons[reason] : "unknown",
8385 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
8387 /* log the debug message */
8392 /* XXX maybe we should actually take notice of this */
8393 always_display = ssh2_pkt_getbool(pktin);
8394 ssh_pkt_getstring(pktin, &msg, &msglen);
8396 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
8399 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
8401 struct Packet *pktout;
8402 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
8403 ssh2_pkt_adduint32(pktout, pktin->sequence);
8405 * UNIMPLEMENTED messages MUST appear in the same order as the
8406 * messages they respond to. Hence, never queue them.
8408 ssh2_pkt_send_noqueue(ssh, pktout);
8412 * Handle the top-level SSH-2 protocol.
8414 static void ssh2_protocol_setup(Ssh ssh)
8419 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
8421 for (i = 0; i < 256; i++)
8422 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
8425 * Any message we actually understand, we set to NULL so that
8426 * the coroutines will get it.
8428 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
8429 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
8430 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
8431 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
8432 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
8433 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
8434 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
8435 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
8436 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
8437 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
8438 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
8439 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
8440 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
8441 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
8442 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8443 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
8444 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
8445 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
8446 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
8447 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
8448 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
8449 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
8450 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
8451 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
8452 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
8453 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
8454 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
8455 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
8456 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
8457 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
8458 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
8459 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
8460 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
8463 * These special message types we install handlers for.
8465 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
8466 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
8467 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
8470 static void ssh2_timer(void *ctx, long now)
8474 if (ssh->state == SSH_STATE_CLOSED)
8477 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
8478 now - ssh->next_rekey >= 0) {
8479 do_ssh2_transport(ssh, "timeout", -1, NULL);
8483 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
8484 struct Packet *pktin)
8486 unsigned char *in = (unsigned char *)vin;
8487 if (ssh->state == SSH_STATE_CLOSED)
8491 ssh->incoming_data_size += pktin->encrypted_len;
8492 if (!ssh->kex_in_progress &&
8493 ssh->max_data_size != 0 &&
8494 ssh->incoming_data_size > ssh->max_data_size)
8495 do_ssh2_transport(ssh, "too much data received", -1, NULL);
8498 if (pktin && ssh->packet_dispatch[pktin->type]) {
8499 ssh->packet_dispatch[pktin->type](ssh, pktin);
8503 if (!ssh->protocol_initial_phase_done ||
8504 (pktin && pktin->type >= 20 && pktin->type < 50)) {
8505 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
8506 !ssh->protocol_initial_phase_done) {
8507 ssh->protocol_initial_phase_done = TRUE;
8509 * Allow authconn to initialise itself.
8511 do_ssh2_authconn(ssh, NULL, 0, NULL);
8514 do_ssh2_authconn(ssh, in, inlen, pktin);
8519 * Called to set up the connection.
8521 * Returns an error message, or NULL on success.
8523 static const char *ssh_init(void *frontend_handle, void **backend_handle,
8525 char *host, int port, char **realhost, int nodelay,
8531 ssh = snew(struct ssh_tag);
8532 ssh->cfg = *cfg; /* STRUCTURE COPY */
8533 ssh->version = 0; /* when not ready yet */
8536 ssh->v1_cipher_ctx = NULL;
8537 ssh->crcda_ctx = NULL;
8538 ssh->cscipher = NULL;
8539 ssh->cs_cipher_ctx = NULL;
8540 ssh->sccipher = NULL;
8541 ssh->sc_cipher_ctx = NULL;
8543 ssh->cs_mac_ctx = NULL;
8545 ssh->sc_mac_ctx = NULL;
8547 ssh->cs_comp_ctx = NULL;
8549 ssh->sc_comp_ctx = NULL;
8551 ssh->kex_ctx = NULL;
8552 ssh->hostkey = NULL;
8554 ssh->close_expected = FALSE;
8555 ssh->clean_exit = FALSE;
8556 ssh->state = SSH_STATE_PREPACKET;
8557 ssh->size_needed = FALSE;
8558 ssh->eof_needed = FALSE;
8561 ssh->deferred_send_data = NULL;
8562 ssh->deferred_len = 0;
8563 ssh->deferred_size = 0;
8564 ssh->fallback_cmd = 0;
8565 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
8566 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8567 ssh->x11auth = NULL;
8568 ssh->v1_compressing = FALSE;
8569 ssh->v2_outgoing_sequence = 0;
8570 ssh->ssh1_rdpkt_crstate = 0;
8571 ssh->ssh2_rdpkt_crstate = 0;
8572 ssh->do_ssh_init_crstate = 0;
8573 ssh->ssh_gotdata_crstate = 0;
8574 ssh->do_ssh1_connection_crstate = 0;
8575 ssh->do_ssh1_login_crstate = 0;
8576 ssh->do_ssh2_transport_crstate = 0;
8577 ssh->do_ssh2_authconn_crstate = 0;
8578 ssh->do_ssh_init_state = NULL;
8579 ssh->do_ssh1_login_state = NULL;
8580 ssh->do_ssh2_transport_state = NULL;
8581 ssh->do_ssh2_authconn_state = NULL;
8584 ssh->mainchan = NULL;
8585 ssh->throttled_all = 0;
8586 ssh->v1_stdout_throttling = 0;
8588 ssh->queuelen = ssh->queuesize = 0;
8589 ssh->queueing = FALSE;
8590 ssh->qhead = ssh->qtail = NULL;
8591 ssh->deferred_rekey_reason = NULL;
8592 bufchain_init(&ssh->queued_incoming_data);
8593 ssh->frozen = FALSE;
8595 *backend_handle = ssh;
8598 if (crypto_startup() == 0)
8599 return "Microsoft high encryption pack not installed!";
8602 ssh->frontend = frontend_handle;
8603 ssh->term_width = ssh->cfg.width;
8604 ssh->term_height = ssh->cfg.height;
8606 ssh->channels = NULL;
8607 ssh->rportfwds = NULL;
8608 ssh->portfwds = NULL;
8613 ssh->v1_throttle_count = 0;
8614 ssh->overall_bufsize = 0;
8615 ssh->fallback_cmd = 0;
8617 ssh->protocol = NULL;
8619 ssh->protocol_initial_phase_done = FALSE;
8623 ssh->incoming_data_size = ssh->outgoing_data_size =
8624 ssh->deferred_data_size = 0L;
8625 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
8626 ssh->kex_in_progress = FALSE;
8628 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
8637 static void ssh_free(void *handle)
8639 Ssh ssh = (Ssh) handle;
8640 struct ssh_channel *c;
8641 struct ssh_rportfwd *pf;
8643 if (ssh->v1_cipher_ctx)
8644 ssh->cipher->free_context(ssh->v1_cipher_ctx);
8645 if (ssh->cs_cipher_ctx)
8646 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
8647 if (ssh->sc_cipher_ctx)
8648 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
8649 if (ssh->cs_mac_ctx)
8650 ssh->csmac->free_context(ssh->cs_mac_ctx);
8651 if (ssh->sc_mac_ctx)
8652 ssh->scmac->free_context(ssh->sc_mac_ctx);
8653 if (ssh->cs_comp_ctx) {
8655 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
8657 zlib_compress_cleanup(ssh->cs_comp_ctx);
8659 if (ssh->sc_comp_ctx) {
8661 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
8663 zlib_decompress_cleanup(ssh->sc_comp_ctx);
8666 dh_cleanup(ssh->kex_ctx);
8667 sfree(ssh->savedhost);
8669 while (ssh->queuelen-- > 0)
8670 ssh_free_packet(ssh->queue[ssh->queuelen]);
8673 while (ssh->qhead) {
8674 struct queued_handler *qh = ssh->qhead;
8675 ssh->qhead = qh->next;
8678 ssh->qhead = ssh->qtail = NULL;
8680 if (ssh->channels) {
8681 while ((c = delpos234(ssh->channels, 0)) != NULL) {
8684 if (c->u.x11.s != NULL)
8685 x11_close(c->u.x11.s);
8688 if (c->u.pfd.s != NULL)
8689 pfd_close(c->u.pfd.s);
8694 freetree234(ssh->channels);
8695 ssh->channels = NULL;
8698 if (ssh->rportfwds) {
8699 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8701 freetree234(ssh->rportfwds);
8702 ssh->rportfwds = NULL;
8704 sfree(ssh->deferred_send_data);
8706 x11_free_auth(ssh->x11auth);
8707 sfree(ssh->do_ssh_init_state);
8708 sfree(ssh->do_ssh1_login_state);
8709 sfree(ssh->do_ssh2_transport_state);
8710 sfree(ssh->do_ssh2_authconn_state);
8713 if (ssh->crcda_ctx) {
8714 crcda_free_context(ssh->crcda_ctx);
8715 ssh->crcda_ctx = NULL;
8718 ssh_do_close(ssh, TRUE);
8719 expire_timer_context(ssh);
8721 pinger_free(ssh->pinger);
8722 bufchain_clear(&ssh->queued_incoming_data);
8729 * Reconfigure the SSH backend.
8731 static void ssh_reconfig(void *handle, Config *cfg)
8733 Ssh ssh = (Ssh) handle;
8734 char *rekeying = NULL, rekey_mandatory = FALSE;
8735 unsigned long old_max_data_size;
8737 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8739 ssh_setup_portfwd(ssh, cfg);
8741 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8742 cfg->ssh_rekey_time != 0) {
8743 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8744 long now = GETTICKCOUNT();
8746 if (new_next - now < 0) {
8747 rekeying = "timeout shortened";
8749 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8753 old_max_data_size = ssh->max_data_size;
8754 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8755 if (old_max_data_size != ssh->max_data_size &&
8756 ssh->max_data_size != 0) {
8757 if (ssh->outgoing_data_size > ssh->max_data_size ||
8758 ssh->incoming_data_size > ssh->max_data_size)
8759 rekeying = "data limit lowered";
8762 if (ssh->cfg.compression != cfg->compression) {
8763 rekeying = "compression setting changed";
8764 rekey_mandatory = TRUE;
8767 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8768 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8769 sizeof(ssh->cfg.ssh_cipherlist))) {
8770 rekeying = "cipher settings changed";
8771 rekey_mandatory = TRUE;
8774 ssh->cfg = *cfg; /* STRUCTURE COPY */
8777 if (!ssh->kex_in_progress) {
8778 do_ssh2_transport(ssh, rekeying, -1, NULL);
8779 } else if (rekey_mandatory) {
8780 ssh->deferred_rekey_reason = rekeying;
8786 * Called to send data down the SSH connection.
8788 static int ssh_send(void *handle, char *buf, int len)
8790 Ssh ssh = (Ssh) handle;
8792 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8795 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8797 return ssh_sendbuffer(ssh);
8801 * Called to query the current amount of buffered stdin data.
8803 static int ssh_sendbuffer(void *handle)
8805 Ssh ssh = (Ssh) handle;
8808 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8812 * If the SSH socket itself has backed up, add the total backup
8813 * size on that to any individual buffer on the stdin channel.
8816 if (ssh->throttled_all)
8817 override_value = ssh->overall_bufsize;
8819 if (ssh->version == 1) {
8820 return override_value;
8821 } else if (ssh->version == 2) {
8822 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8823 return override_value;
8825 return (override_value +
8826 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8833 * Called to set the size of the window from SSH's POV.
8835 static void ssh_size(void *handle, int width, int height)
8837 Ssh ssh = (Ssh) handle;
8838 struct Packet *pktout;
8840 ssh->term_width = width;
8841 ssh->term_height = height;
8843 switch (ssh->state) {
8844 case SSH_STATE_BEFORE_SIZE:
8845 case SSH_STATE_PREPACKET:
8846 case SSH_STATE_CLOSED:
8847 break; /* do nothing */
8848 case SSH_STATE_INTERMED:
8849 ssh->size_needed = TRUE; /* buffer for later */
8851 case SSH_STATE_SESSION:
8852 if (!ssh->cfg.nopty) {
8853 if (ssh->version == 1) {
8854 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8855 PKT_INT, ssh->term_height,
8856 PKT_INT, ssh->term_width,
8857 PKT_INT, 0, PKT_INT, 0, PKT_END);
8858 } else if (ssh->mainchan) {
8859 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8860 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8861 ssh2_pkt_addstring(pktout, "window-change");
8862 ssh2_pkt_addbool(pktout, 0);
8863 ssh2_pkt_adduint32(pktout, ssh->term_width);
8864 ssh2_pkt_adduint32(pktout, ssh->term_height);
8865 ssh2_pkt_adduint32(pktout, 0);
8866 ssh2_pkt_adduint32(pktout, 0);
8867 ssh2_pkt_send(ssh, pktout);
8875 * Return a list of the special codes that make sense in this
8878 static const struct telnet_special *ssh_get_specials(void *handle)
8880 static const struct telnet_special ssh1_ignore_special[] = {
8881 {"IGNORE message", TS_NOP}
8883 static const struct telnet_special ssh2_transport_specials[] = {
8884 {"IGNORE message", TS_NOP},
8885 {"Repeat key exchange", TS_REKEY},
8887 static const struct telnet_special ssh2_session_specials[] = {
8890 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8891 * They include all the ISO C signals, but are a subset of the POSIX
8892 * required signals. */
8893 {"SIGINT (Interrupt)", TS_SIGINT},
8894 {"SIGTERM (Terminate)", TS_SIGTERM},
8895 {"SIGKILL (Kill)", TS_SIGKILL},
8896 {"SIGQUIT (Quit)", TS_SIGQUIT},
8897 {"SIGHUP (Hangup)", TS_SIGHUP},
8898 {"More signals", TS_SUBMENU},
8899 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8900 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8901 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8902 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8905 static const struct telnet_special specials_end[] = {
8908 /* XXX review this length for any changes: */
8909 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8910 lenof(ssh2_session_specials) +
8911 lenof(specials_end)];
8912 Ssh ssh = (Ssh) handle;
8914 #define ADD_SPECIALS(name) \
8916 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8917 memcpy(&ssh_specials[i], name, sizeof name); \
8921 if (ssh->version == 1) {
8922 /* Don't bother offering IGNORE if we've decided the remote
8923 * won't cope with it, since we wouldn't bother sending it if
8925 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8926 ADD_SPECIALS(ssh1_ignore_special);
8927 } else if (ssh->version == 2) {
8928 ADD_SPECIALS(ssh2_transport_specials);
8930 ADD_SPECIALS(ssh2_session_specials);
8931 } /* else we're not ready yet */
8934 ADD_SPECIALS(specials_end);
8935 return ssh_specials;
8943 * Send special codes. TS_EOF is useful for `plink', so you
8944 * can send an EOF and collect resulting output (e.g. `plink
8947 static void ssh_special(void *handle, Telnet_Special code)
8949 Ssh ssh = (Ssh) handle;
8950 struct Packet *pktout;
8952 if (code == TS_EOF) {
8953 if (ssh->state != SSH_STATE_SESSION) {
8955 * Buffer the EOF in case we are pre-SESSION, so we can
8956 * send it as soon as we reach SESSION.
8959 ssh->eof_needed = TRUE;
8962 if (ssh->version == 1) {
8963 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8964 } else if (ssh->mainchan) {
8965 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8966 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8967 ssh2_pkt_send(ssh, pktout);
8968 ssh->send_ok = 0; /* now stop trying to read from stdin */
8970 logevent("Sent EOF message");
8971 } else if (code == TS_PING || code == TS_NOP) {
8972 if (ssh->state == SSH_STATE_CLOSED
8973 || ssh->state == SSH_STATE_PREPACKET) return;
8974 if (ssh->version == 1) {
8975 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8976 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8978 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8979 ssh2_pkt_addstring_start(pktout);
8980 ssh2_pkt_send_noqueue(ssh, pktout);
8982 } else if (code == TS_REKEY) {
8983 if (!ssh->kex_in_progress && ssh->version == 2) {
8984 do_ssh2_transport(ssh, "at user request", -1, NULL);
8986 } else if (code == TS_BRK) {
8987 if (ssh->state == SSH_STATE_CLOSED
8988 || ssh->state == SSH_STATE_PREPACKET) return;
8989 if (ssh->version == 1) {
8990 logevent("Unable to send BREAK signal in SSH-1");
8991 } else if (ssh->mainchan) {
8992 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8993 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8994 ssh2_pkt_addstring(pktout, "break");
8995 ssh2_pkt_addbool(pktout, 0);
8996 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8997 ssh2_pkt_send(ssh, pktout);
9000 /* Is is a POSIX signal? */
9001 char *signame = NULL;
9002 if (code == TS_SIGABRT) signame = "ABRT";
9003 if (code == TS_SIGALRM) signame = "ALRM";
9004 if (code == TS_SIGFPE) signame = "FPE";
9005 if (code == TS_SIGHUP) signame = "HUP";
9006 if (code == TS_SIGILL) signame = "ILL";
9007 if (code == TS_SIGINT) signame = "INT";
9008 if (code == TS_SIGKILL) signame = "KILL";
9009 if (code == TS_SIGPIPE) signame = "PIPE";
9010 if (code == TS_SIGQUIT) signame = "QUIT";
9011 if (code == TS_SIGSEGV) signame = "SEGV";
9012 if (code == TS_SIGTERM) signame = "TERM";
9013 if (code == TS_SIGUSR1) signame = "USR1";
9014 if (code == TS_SIGUSR2) signame = "USR2";
9015 /* The SSH-2 protocol does in principle support arbitrary named
9016 * signals, including signame@domain, but we don't support those. */
9018 /* It's a signal. */
9019 if (ssh->version == 2 && ssh->mainchan) {
9020 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9021 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9022 ssh2_pkt_addstring(pktout, "signal");
9023 ssh2_pkt_addbool(pktout, 0);
9024 ssh2_pkt_addstring(pktout, signame);
9025 ssh2_pkt_send(ssh, pktout);
9026 logeventf(ssh, "Sent signal SIG%s", signame);
9029 /* Never heard of it. Do nothing */
9034 void *new_sock_channel(void *handle, Socket s)
9036 Ssh ssh = (Ssh) handle;
9037 struct ssh_channel *c;
9038 c = snew(struct ssh_channel);
9043 c->localid = alloc_channel_id(ssh);
9045 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
9047 bufchain_init(&c->v.v2.outbuffer);
9048 add234(ssh->channels, c);
9054 * This is called when stdout/stderr (the entity to which
9055 * from_backend sends data) manages to clear some backlog.
9057 static void ssh_unthrottle(void *handle, int bufsize)
9059 Ssh ssh = (Ssh) handle;
9060 if (ssh->version == 1) {
9061 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
9062 ssh->v1_stdout_throttling = 0;
9063 ssh1_throttle(ssh, -1);
9066 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
9070 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
9072 struct ssh_channel *c = (struct ssh_channel *)channel;
9074 struct Packet *pktout;
9076 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
9078 if (ssh->version == 1) {
9079 send_packet(ssh, SSH1_MSG_PORT_OPEN,
9080 PKT_INT, c->localid,
9083 /* PKT_STR, <org:orgport>, */
9086 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9087 ssh2_pkt_addstring(pktout, "direct-tcpip");
9088 ssh2_pkt_adduint32(pktout, c->localid);
9089 c->v.v2.locwindow = OUR_V2_WINSIZE;
9090 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
9091 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
9092 ssh2_pkt_addstring(pktout, hostname);
9093 ssh2_pkt_adduint32(pktout, port);
9095 * We make up values for the originator data; partly it's
9096 * too much hassle to keep track, and partly I'm not
9097 * convinced the server should be told details like that
9098 * about my local network configuration.
9099 * The "originator IP address" is syntactically a numeric
9100 * IP address, and some servers (e.g., Tectia) get upset
9101 * if it doesn't match this syntax.
9103 ssh2_pkt_addstring(pktout, "0.0.0.0");
9104 ssh2_pkt_adduint32(pktout, 0);
9105 ssh2_pkt_send(ssh, pktout);
9109 static int ssh_connected(void *handle)
9111 Ssh ssh = (Ssh) handle;
9112 return ssh->s != NULL;
9115 static int ssh_sendok(void *handle)
9117 Ssh ssh = (Ssh) handle;
9118 return ssh->send_ok;
9121 static int ssh_ldisc(void *handle, int option)
9123 Ssh ssh = (Ssh) handle;
9124 if (option == LD_ECHO)
9125 return ssh->echoing;
9126 if (option == LD_EDIT)
9127 return ssh->editing;
9131 static void ssh_provide_ldisc(void *handle, void *ldisc)
9133 Ssh ssh = (Ssh) handle;
9137 static void ssh_provide_logctx(void *handle, void *logctx)
9139 Ssh ssh = (Ssh) handle;
9140 ssh->logctx = logctx;
9143 static int ssh_return_exitcode(void *handle)
9145 Ssh ssh = (Ssh) handle;
9149 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
9153 * cfg_info for SSH is the currently running version of the
9154 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
9156 static int ssh_cfg_info(void *handle)
9158 Ssh ssh = (Ssh) handle;
9159 return ssh->version;
9163 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
9164 * that fails. This variable is the means by which scp.c can reach
9165 * into the SSH code and find out which one it got.
9167 extern int ssh_fallback_cmd(void *handle)
9169 Ssh ssh = (Ssh) handle;
9170 return ssh->fallback_cmd;
9173 Backend ssh_backend = {
9183 ssh_return_exitcode,