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 = 4;
1226 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1227 do_blank = TRUE; blank_prefix = 8;
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 = 8;
1386 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1387 do_blank = TRUE; blank_prefix = 12;
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,
4004 PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len,
4005 PKTT_OTHER, PKT_END);
4007 * In SSH-1 we can return 0 here - implying that forwarded
4008 * connections are never individually throttled - because
4009 * the only circumstance that can cause throttling will be
4010 * the whole SSH connection backing up, in which case
4011 * _everything_ will be throttled as a whole.
4015 ssh2_add_channel_data(c, buf, len);
4016 return ssh2_try_send(c);
4020 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
4024 if (ssh->state == SSH_STATE_CLOSED)
4027 if (ssh->version == 1) {
4028 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
4029 c->v.v1.throttling = 0;
4030 ssh1_throttle(ssh, -1);
4033 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
4037 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
4039 struct queued_handler *qh = ssh->qhead;
4043 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
4046 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
4047 ssh->packet_dispatch[qh->msg1] = NULL;
4050 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
4051 ssh->packet_dispatch[qh->msg2] = NULL;
4055 ssh->qhead = qh->next;
4057 if (ssh->qhead->msg1 > 0) {
4058 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
4059 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
4061 if (ssh->qhead->msg2 > 0) {
4062 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
4063 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
4066 ssh->qhead = ssh->qtail = NULL;
4067 ssh->packet_dispatch[pktin->type] = NULL;
4070 qh->handler(ssh, pktin, qh->ctx);
4075 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
4076 chandler_fn_t handler, void *ctx)
4078 struct queued_handler *qh;
4080 qh = snew(struct queued_handler);
4083 qh->handler = handler;
4087 if (ssh->qtail == NULL) {
4091 assert(ssh->packet_dispatch[qh->msg1] == NULL);
4092 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
4095 assert(ssh->packet_dispatch[qh->msg2] == NULL);
4096 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
4099 ssh->qtail->next = qh;
4104 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
4106 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
4108 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
4109 SSH2_MSG_REQUEST_SUCCESS)) {
4110 logeventf(ssh, "Remote port forwarding from %s enabled",
4113 logeventf(ssh, "Remote port forwarding from %s refused",
4116 rpf = del234(ssh->rportfwds, pf);
4122 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
4124 const char *portfwd_strptr = cfg->portfwd;
4125 struct ssh_portfwd *epf;
4128 if (!ssh->portfwds) {
4129 ssh->portfwds = newtree234(ssh_portcmp);
4132 * Go through the existing port forwardings and tag them
4133 * with status==DESTROY. Any that we want to keep will be
4134 * re-enabled (status==KEEP) as we go through the
4135 * configuration and find out which bits are the same as
4138 struct ssh_portfwd *epf;
4140 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4141 epf->status = DESTROY;
4144 while (*portfwd_strptr) {
4145 char address_family, type;
4146 int sport,dport,sserv,dserv;
4147 char sports[256], dports[256], saddr[256], host[256];
4150 address_family = 'A';
4152 if (*portfwd_strptr == 'A' ||
4153 *portfwd_strptr == '4' ||
4154 *portfwd_strptr == '6')
4155 address_family = *portfwd_strptr++;
4156 if (*portfwd_strptr == 'L' ||
4157 *portfwd_strptr == 'R' ||
4158 *portfwd_strptr == 'D')
4159 type = *portfwd_strptr++;
4164 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4165 if (*portfwd_strptr == ':') {
4167 * We've seen a colon in the middle of the
4168 * source port number. This means that
4169 * everything we've seen until now is the
4170 * source _address_, so we'll move it into
4171 * saddr and start sports from the beginning
4176 if (ssh->version == 1 && type == 'R') {
4177 logeventf(ssh, "SSH-1 cannot handle remote source address "
4178 "spec \"%s\"; ignoring", sports);
4180 strcpy(saddr, sports);
4183 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4187 if (*portfwd_strptr == '\t')
4190 while (*portfwd_strptr && *portfwd_strptr != ':') {
4191 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4194 if (*portfwd_strptr == ':')
4197 while (*portfwd_strptr) {
4198 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4202 dport = atoi(dports);
4206 dport = net_service_lookup(dports);
4208 logeventf(ssh, "Service lookup failed for destination"
4209 " port \"%s\"", dports);
4213 while (*portfwd_strptr) portfwd_strptr++;
4217 portfwd_strptr++; /* eat the NUL and move to next one */
4219 sport = atoi(sports);
4223 sport = net_service_lookup(sports);
4225 logeventf(ssh, "Service lookup failed for source"
4226 " port \"%s\"", sports);
4229 if (sport && dport) {
4230 /* Set up a description of the source port. */
4231 struct ssh_portfwd *pfrec, *epfrec;
4233 pfrec = snew(struct ssh_portfwd);
4235 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4236 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4237 pfrec->sport = sport;
4238 pfrec->daddr = *host ? dupstr(host) : NULL;
4239 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4240 pfrec->dport = dport;
4241 pfrec->local = NULL;
4242 pfrec->remote = NULL;
4243 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4244 address_family == '6' ? ADDRTYPE_IPV6 :
4247 epfrec = add234(ssh->portfwds, pfrec);
4248 if (epfrec != pfrec) {
4250 * We already have a port forwarding with precisely
4251 * these parameters. Hence, no need to do anything;
4252 * simply tag the existing one as KEEP.
4254 epfrec->status = KEEP;
4255 free_portfwd(pfrec);
4257 pfrec->status = CREATE;
4263 * Now go through and destroy any port forwardings which were
4266 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4267 if (epf->status == DESTROY) {
4270 message = dupprintf("%s port forwarding from %s%s%d",
4271 epf->type == 'L' ? "local" :
4272 epf->type == 'R' ? "remote" : "dynamic",
4273 epf->saddr ? epf->saddr : "",
4274 epf->saddr ? ":" : "",
4277 if (epf->type != 'D') {
4278 char *msg2 = dupprintf("%s to %s:%d", message,
4279 epf->daddr, epf->dport);
4284 logeventf(ssh, "Cancelling %s", message);
4288 struct ssh_rportfwd *rpf = epf->remote;
4289 struct Packet *pktout;
4292 * Cancel the port forwarding at the server
4295 if (ssh->version == 1) {
4297 * We cannot cancel listening ports on the
4298 * server side in SSH-1! There's no message
4299 * to support it. Instead, we simply remove
4300 * the rportfwd record from the local end
4301 * so that any connections the server tries
4302 * to make on it are rejected.
4305 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4306 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4307 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4309 ssh2_pkt_addstring(pktout, epf->saddr);
4310 } else if (ssh->cfg.rport_acceptall) {
4311 /* XXX: ssh->cfg.rport_acceptall may not represent
4312 * what was used to open the original connection,
4313 * since it's reconfigurable. */
4314 ssh2_pkt_addstring(pktout, "0.0.0.0");
4316 ssh2_pkt_addstring(pktout, "127.0.0.1");
4318 ssh2_pkt_adduint32(pktout, epf->sport);
4319 ssh2_pkt_send(ssh, pktout);
4322 del234(ssh->rportfwds, rpf);
4324 } else if (epf->local) {
4325 pfd_terminate(epf->local);
4328 delpos234(ssh->portfwds, i);
4330 i--; /* so we don't skip one in the list */
4334 * And finally, set up any new port forwardings (status==CREATE).
4336 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4337 if (epf->status == CREATE) {
4338 char *sportdesc, *dportdesc;
4339 sportdesc = dupprintf("%s%s%s%s%d%s",
4340 epf->saddr ? epf->saddr : "",
4341 epf->saddr ? ":" : "",
4342 epf->sserv ? epf->sserv : "",
4343 epf->sserv ? "(" : "",
4345 epf->sserv ? ")" : "");
4346 if (epf->type == 'D') {
4349 dportdesc = dupprintf("%s:%s%s%d%s",
4351 epf->dserv ? epf->dserv : "",
4352 epf->dserv ? "(" : "",
4354 epf->dserv ? ")" : "");
4357 if (epf->type == 'L') {
4358 const char *err = pfd_addforward(epf->daddr, epf->dport,
4359 epf->saddr, epf->sport,
4362 epf->addressfamily);
4364 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4365 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4366 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4367 sportdesc, dportdesc,
4368 err ? " failed: " : "", err ? err : "");
4369 } else if (epf->type == 'D') {
4370 const char *err = pfd_addforward(NULL, -1,
4371 epf->saddr, epf->sport,
4374 epf->addressfamily);
4376 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4377 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4378 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4380 err ? " failed: " : "", err ? err : "");
4382 struct ssh_rportfwd *pf;
4385 * Ensure the remote port forwardings tree exists.
4387 if (!ssh->rportfwds) {
4388 if (ssh->version == 1)
4389 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4391 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4394 pf = snew(struct ssh_rportfwd);
4395 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4396 pf->dhost[lenof(pf->dhost)-1] = '\0';
4397 pf->dport = epf->dport;
4398 pf->sport = epf->sport;
4399 if (add234(ssh->rportfwds, pf) != pf) {
4400 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4401 epf->daddr, epf->dport);
4404 logeventf(ssh, "Requesting remote port %s"
4405 " forward to %s", sportdesc, dportdesc);
4407 pf->sportdesc = sportdesc;
4412 if (ssh->version == 1) {
4413 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4414 PKT_INT, epf->sport,
4415 PKT_STR, epf->daddr,
4416 PKT_INT, epf->dport,
4418 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4420 ssh_rportfwd_succfail, pf);
4422 struct Packet *pktout;
4423 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4424 ssh2_pkt_addstring(pktout, "tcpip-forward");
4425 ssh2_pkt_addbool(pktout, 1);/* want reply */
4427 ssh2_pkt_addstring(pktout, epf->saddr);
4428 } else if (cfg->rport_acceptall) {
4429 ssh2_pkt_addstring(pktout, "0.0.0.0");
4431 ssh2_pkt_addstring(pktout, "127.0.0.1");
4433 ssh2_pkt_adduint32(pktout, epf->sport);
4434 ssh2_pkt_send(ssh, pktout);
4436 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4437 SSH2_MSG_REQUEST_FAILURE,
4438 ssh_rportfwd_succfail, pf);
4447 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4450 int stringlen, bufsize;
4452 ssh_pkt_getstring(pktin, &string, &stringlen);
4453 if (string == NULL) {
4454 bombout(("Incoming terminal data packet was badly formed"));
4458 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4460 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4461 ssh->v1_stdout_throttling = 1;
4462 ssh1_throttle(ssh, +1);
4466 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4468 /* Remote side is trying to open a channel to talk to our
4469 * X-Server. Give them back a local channel number. */
4470 struct ssh_channel *c;
4471 int remoteid = ssh_pkt_getuint32(pktin);
4473 logevent("Received X11 connect request");
4474 /* Refuse if X11 forwarding is disabled. */
4475 if (!ssh->X11_fwd_enabled) {
4476 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4477 PKT_INT, remoteid, PKT_END);
4478 logevent("Rejected X11 connect request");
4480 c = snew(struct ssh_channel);
4483 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4484 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4485 logevent("Opening X11 forward connection failed");
4487 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4488 PKT_INT, remoteid, PKT_END);
4491 ("Opening X11 forward connection succeeded");
4492 c->remoteid = remoteid;
4493 c->halfopen = FALSE;
4494 c->localid = alloc_channel_id(ssh);
4496 c->v.v1.throttling = 0;
4497 c->type = CHAN_X11; /* identify channel type */
4498 add234(ssh->channels, c);
4499 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4500 PKT_INT, c->remoteid, PKT_INT,
4501 c->localid, PKT_END);
4502 logevent("Opened X11 forward channel");
4507 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4509 /* Remote side is trying to open a channel to talk to our
4510 * agent. Give them back a local channel number. */
4511 struct ssh_channel *c;
4512 int remoteid = ssh_pkt_getuint32(pktin);
4514 /* Refuse if agent forwarding is disabled. */
4515 if (!ssh->agentfwd_enabled) {
4516 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4517 PKT_INT, remoteid, PKT_END);
4519 c = snew(struct ssh_channel);
4521 c->remoteid = remoteid;
4522 c->halfopen = FALSE;
4523 c->localid = alloc_channel_id(ssh);
4525 c->v.v1.throttling = 0;
4526 c->type = CHAN_AGENT; /* identify channel type */
4527 c->u.a.lensofar = 0;
4528 add234(ssh->channels, c);
4529 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4530 PKT_INT, c->remoteid, PKT_INT, c->localid,
4535 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4537 /* Remote side is trying to open a channel to talk to a
4538 * forwarded port. Give them back a local channel number. */
4539 struct ssh_channel *c;
4540 struct ssh_rportfwd pf, *pfp;
4545 c = snew(struct ssh_channel);
4548 remoteid = ssh_pkt_getuint32(pktin);
4549 ssh_pkt_getstring(pktin, &host, &hostsize);
4550 port = ssh_pkt_getuint32(pktin);
4552 if (hostsize >= lenof(pf.dhost))
4553 hostsize = lenof(pf.dhost)-1;
4554 memcpy(pf.dhost, host, hostsize);
4555 pf.dhost[hostsize] = '\0';
4557 pfp = find234(ssh->rportfwds, &pf, NULL);
4560 logeventf(ssh, "Rejected remote port open request for %s:%d",
4562 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4563 PKT_INT, remoteid, PKT_END);
4565 logeventf(ssh, "Received remote port open request for %s:%d",
4567 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4568 c, &ssh->cfg, pfp->pfrec->addressfamily);
4570 logeventf(ssh, "Port open failed: %s", e);
4572 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4573 PKT_INT, remoteid, PKT_END);
4575 c->remoteid = remoteid;
4576 c->halfopen = FALSE;
4577 c->localid = alloc_channel_id(ssh);
4579 c->v.v1.throttling = 0;
4580 c->type = CHAN_SOCKDATA; /* identify channel type */
4581 add234(ssh->channels, c);
4582 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4583 PKT_INT, c->remoteid, PKT_INT,
4584 c->localid, PKT_END);
4585 logevent("Forwarded port opened successfully");
4590 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4592 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4593 unsigned int localid = ssh_pkt_getuint32(pktin);
4594 struct ssh_channel *c;
4596 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4597 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4598 c->remoteid = localid;
4599 c->halfopen = FALSE;
4600 c->type = CHAN_SOCKDATA;
4601 c->v.v1.throttling = 0;
4602 pfd_confirm(c->u.pfd.s);
4605 if (c && c->closes) {
4607 * We have a pending close on this channel,
4608 * which we decided on before the server acked
4609 * the channel open. So now we know the
4610 * remoteid, we can close it again.
4612 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4613 PKT_INT, c->remoteid, PKT_END);
4617 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4619 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4620 struct ssh_channel *c;
4622 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4623 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4624 logevent("Forwarded connection refused by server");
4625 pfd_close(c->u.pfd.s);
4626 del234(ssh->channels, c);
4631 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4633 /* Remote side closes a channel. */
4634 unsigned i = ssh_pkt_getuint32(pktin);
4635 struct ssh_channel *c;
4636 c = find234(ssh->channels, &i, ssh_channelfind);
4637 if (c && !c->halfopen) {
4640 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4642 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4643 logevent("Forwarded X11 connection terminated");
4644 assert(c->u.x11.s != NULL);
4645 x11_close(c->u.x11.s);
4648 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4649 logevent("Forwarded port closed");
4650 assert(c->u.pfd.s != NULL);
4651 pfd_close(c->u.pfd.s);
4655 c->closes |= (closetype << 2); /* seen this message */
4656 if (!(c->closes & closetype)) {
4657 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4659 c->closes |= closetype; /* sent it too */
4662 if (c->closes == 15) {
4663 del234(ssh->channels, c);
4667 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4668 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4669 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4674 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4676 /* Data sent down one of our channels. */
4677 int i = ssh_pkt_getuint32(pktin);
4680 struct ssh_channel *c;
4682 ssh_pkt_getstring(pktin, &p, &len);
4684 c = find234(ssh->channels, &i, ssh_channelfind);
4689 bufsize = x11_send(c->u.x11.s, p, len);
4692 bufsize = pfd_send(c->u.pfd.s, p, len);
4695 /* Data for an agent message. Buffer it. */
4697 if (c->u.a.lensofar < 4) {
4698 unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len);
4699 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4703 c->u.a.lensofar += l;
4705 if (c->u.a.lensofar == 4) {
4707 4 + GET_32BIT(c->u.a.msglen);
4708 c->u.a.message = snewn(c->u.a.totallen,
4710 memcpy(c->u.a.message, c->u.a.msglen, 4);
4712 if (c->u.a.lensofar >= 4 && len > 0) {
4714 min(c->u.a.totallen - c->u.a.lensofar,
4716 memcpy(c->u.a.message + c->u.a.lensofar, p,
4720 c->u.a.lensofar += l;
4722 if (c->u.a.lensofar == c->u.a.totallen) {
4725 if (agent_query(c->u.a.message,
4728 ssh_agentf_callback, c))
4729 ssh_agentf_callback(c, reply, replylen);
4730 sfree(c->u.a.message);
4731 c->u.a.lensofar = 0;
4734 bufsize = 0; /* agent channels never back up */
4737 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4738 c->v.v1.throttling = 1;
4739 ssh1_throttle(ssh, +1);
4744 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4746 ssh->exitcode = ssh_pkt_getuint32(pktin);
4747 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4748 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4750 * In case `helpful' firewalls or proxies tack
4751 * extra human-readable text on the end of the
4752 * session which we might mistake for another
4753 * encrypted packet, we close the session once
4754 * we've sent EXIT_CONFIRMATION.
4756 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4759 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4760 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4762 struct Packet *pktout = (struct Packet *)data;
4764 unsigned int arg = 0;
4765 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4766 if (i == lenof(ssh_ttymodes)) return;
4767 switch (ssh_ttymodes[i].type) {
4769 arg = ssh_tty_parse_specchar(val);
4772 arg = ssh_tty_parse_boolean(val);
4775 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4776 ssh2_pkt_addbyte(pktout, arg);
4780 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4781 struct Packet *pktin)
4783 crBegin(ssh->do_ssh1_connection_crstate);
4785 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4786 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4787 ssh1_smsg_stdout_stderr_data;
4789 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4790 ssh1_msg_channel_open_confirmation;
4791 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4792 ssh1_msg_channel_open_failure;
4793 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4794 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4795 ssh1_msg_channel_close;
4796 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4797 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4799 if (ssh->cfg.agentfwd && agent_exists()) {
4800 logevent("Requesting agent forwarding");
4801 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4805 if (pktin->type != SSH1_SMSG_SUCCESS
4806 && pktin->type != SSH1_SMSG_FAILURE) {
4807 bombout(("Protocol confusion"));
4809 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4810 logevent("Agent forwarding refused");
4812 logevent("Agent forwarding enabled");
4813 ssh->agentfwd_enabled = TRUE;
4814 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4818 if (ssh->cfg.x11_forward) {
4819 char proto[20], data[64];
4820 logevent("Requesting X11 forwarding");
4821 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4822 data, sizeof(data), ssh->cfg.x11_auth);
4823 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4825 * Note that while we blank the X authentication data here, we don't
4826 * take any special action to blank the start of an X11 channel,
4827 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4828 * without having session blanking enabled is likely to leak your
4829 * cookie into the log.
4831 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4832 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4834 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4835 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4838 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4840 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4845 if (pktin->type != SSH1_SMSG_SUCCESS
4846 && pktin->type != SSH1_SMSG_FAILURE) {
4847 bombout(("Protocol confusion"));
4849 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4850 logevent("X11 forwarding refused");
4852 logevent("X11 forwarding enabled");
4853 ssh->X11_fwd_enabled = TRUE;
4854 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4858 ssh_setup_portfwd(ssh, &ssh->cfg);
4859 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4861 if (!ssh->cfg.nopty) {
4863 /* Unpick the terminal-speed string. */
4864 /* XXX perhaps we should allow no speeds to be sent. */
4865 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4866 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4867 /* Send the pty request. */
4868 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4869 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4870 ssh_pkt_adduint32(pkt, ssh->term_height);
4871 ssh_pkt_adduint32(pkt, ssh->term_width);
4872 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4873 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4874 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4875 ssh1_send_ttymode, (void *)pkt);
4876 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4877 ssh_pkt_adduint32(pkt, ssh->ispeed);
4878 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4879 ssh_pkt_adduint32(pkt, ssh->ospeed);
4880 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4882 ssh->state = SSH_STATE_INTERMED;
4886 if (pktin->type != SSH1_SMSG_SUCCESS
4887 && pktin->type != SSH1_SMSG_FAILURE) {
4888 bombout(("Protocol confusion"));
4890 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4891 c_write_str(ssh, "Server refused to allocate pty\r\n");
4892 ssh->editing = ssh->echoing = 1;
4894 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4895 ssh->ospeed, ssh->ispeed);
4897 ssh->editing = ssh->echoing = 1;
4900 if (ssh->cfg.compression) {
4901 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4905 if (pktin->type != SSH1_SMSG_SUCCESS
4906 && pktin->type != SSH1_SMSG_FAILURE) {
4907 bombout(("Protocol confusion"));
4909 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4910 c_write_str(ssh, "Server refused to compress\r\n");
4912 logevent("Started compression");
4913 ssh->v1_compressing = TRUE;
4914 ssh->cs_comp_ctx = zlib_compress_init();
4915 logevent("Initialised zlib (RFC1950) compression");
4916 ssh->sc_comp_ctx = zlib_decompress_init();
4917 logevent("Initialised zlib (RFC1950) decompression");
4921 * Start the shell or command.
4923 * Special case: if the first-choice command is an SSH-2
4924 * subsystem (hence not usable here) and the second choice
4925 * exists, we fall straight back to that.
4928 char *cmd = ssh->cfg.remote_cmd_ptr;
4930 if (!cmd) cmd = ssh->cfg.remote_cmd;
4932 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4933 cmd = ssh->cfg.remote_cmd_ptr2;
4934 ssh->fallback_cmd = TRUE;
4937 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4939 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4940 logevent("Started session");
4943 ssh->state = SSH_STATE_SESSION;
4944 if (ssh->size_needed)
4945 ssh_size(ssh, ssh->term_width, ssh->term_height);
4946 if (ssh->eof_needed)
4947 ssh_special(ssh, TS_EOF);
4950 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4952 ssh->channels = newtree234(ssh_channelcmp);
4956 * By this point, most incoming packets are already being
4957 * handled by the dispatch table, and we need only pay
4958 * attention to the unusual ones.
4963 if (pktin->type == SSH1_SMSG_SUCCESS) {
4964 /* may be from EXEC_SHELL on some servers */
4965 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4966 /* may be from EXEC_SHELL on some servers
4967 * if no pty is available or in other odd cases. Ignore */
4969 bombout(("Strange packet received: type %d", pktin->type));
4974 int len = min(inlen, 512);
4975 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
4976 PKT_INT, len, PKTT_DATA, PKT_DATA, in, len,
4977 PKTT_OTHER, PKT_END);
4988 * Handle the top-level SSH-2 protocol.
4990 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4995 ssh_pkt_getstring(pktin, &msg, &msglen);
4996 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4999 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
5001 /* log reason code in disconnect message */
5005 ssh_pkt_getstring(pktin, &msg, &msglen);
5006 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
5009 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
5011 /* Do nothing, because we're ignoring it! Duhh. */
5014 static void ssh1_protocol_setup(Ssh ssh)
5019 * Most messages are handled by the coroutines.
5021 for (i = 0; i < 256; i++)
5022 ssh->packet_dispatch[i] = NULL;
5025 * These special message types we install handlers for.
5027 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
5028 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
5029 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
5032 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
5033 struct Packet *pktin)
5035 unsigned char *in=(unsigned char*)vin;
5036 if (ssh->state == SSH_STATE_CLOSED)
5039 if (pktin && ssh->packet_dispatch[pktin->type]) {
5040 ssh->packet_dispatch[pktin->type](ssh, pktin);
5044 if (!ssh->protocol_initial_phase_done) {
5045 if (do_ssh1_login(ssh, in, inlen, pktin))
5046 ssh->protocol_initial_phase_done = TRUE;
5051 do_ssh1_connection(ssh, in, inlen, pktin);
5055 * Utility routine for decoding comma-separated strings in KEXINIT.
5057 static int in_commasep_string(char *needle, char *haystack, int haylen)
5060 if (!needle || !haystack) /* protect against null pointers */
5062 needlen = strlen(needle);
5065 * Is it at the start of the string?
5067 if (haylen >= needlen && /* haystack is long enough */
5068 !memcmp(needle, haystack, needlen) && /* initial match */
5069 (haylen == needlen || haystack[needlen] == ',')
5070 /* either , or EOS follows */
5074 * If not, search for the next comma and resume after that.
5075 * If no comma found, terminate.
5077 while (haylen > 0 && *haystack != ',')
5078 haylen--, haystack++;
5081 haylen--, haystack++; /* skip over comma itself */
5086 * Similar routine for checking whether we have the first string in a list.
5088 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
5091 if (!needle || !haystack) /* protect against null pointers */
5093 needlen = strlen(needle);
5095 * Is it at the start of the string?
5097 if (haylen >= needlen && /* haystack is long enough */
5098 !memcmp(needle, haystack, needlen) && /* initial match */
5099 (haylen == needlen || haystack[needlen] == ',')
5100 /* either , or EOS follows */
5108 * SSH-2 key creation method.
5109 * (Currently assumes 2 lots of any hash are sufficient to generate
5110 * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.)
5112 #define SSH2_MKKEY_ITERS (2)
5113 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
5114 unsigned char *keyspace)
5116 const struct ssh_hash *h = ssh->kex->hash;
5118 /* First hlen bytes. */
5120 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5121 hash_mpint(h, s, K);
5122 h->bytes(s, H, h->hlen);
5123 h->bytes(s, &chr, 1);
5124 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
5125 h->final(s, keyspace);
5126 /* Next hlen bytes. */
5128 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
5129 hash_mpint(h, s, K);
5130 h->bytes(s, H, h->hlen);
5131 h->bytes(s, keyspace, h->hlen);
5132 h->final(s, keyspace + h->hlen);
5136 * Handle the SSH-2 transport layer.
5138 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
5139 struct Packet *pktin)
5141 unsigned char *in = (unsigned char *)vin;
5142 struct do_ssh2_transport_state {
5143 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
5144 Bignum p, g, e, f, K;
5147 int kex_init_value, kex_reply_value;
5148 const struct ssh_mac **maclist;
5150 const struct ssh2_cipher *cscipher_tobe;
5151 const struct ssh2_cipher *sccipher_tobe;
5152 const struct ssh_mac *csmac_tobe;
5153 const struct ssh_mac *scmac_tobe;
5154 const struct ssh_compress *cscomp_tobe;
5155 const struct ssh_compress *sccomp_tobe;
5156 char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint;
5157 int hostkeylen, siglen, rsakeylen;
5158 void *hkey; /* actual host key */
5159 void *rsakey; /* for RSA kex */
5160 unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN];
5161 int n_preferred_kex;
5162 const struct ssh_kexes *preferred_kex[KEX_MAX];
5163 int n_preferred_ciphers;
5164 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5165 const struct ssh_compress *preferred_comp;
5166 int got_session_id, activated_authconn;
5167 struct Packet *pktout;
5172 crState(do_ssh2_transport_state);
5174 crBegin(ssh->do_ssh2_transport_crstate);
5176 s->cscipher_tobe = s->sccipher_tobe = NULL;
5177 s->csmac_tobe = s->scmac_tobe = NULL;
5178 s->cscomp_tobe = s->sccomp_tobe = NULL;
5180 s->got_session_id = s->activated_authconn = FALSE;
5183 * Be prepared to work around the buggy MAC problem.
5185 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5186 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5188 s->maclist = macs, s->nmacs = lenof(macs);
5191 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
5193 int i, j, commalist_started;
5196 * Set up the preferred key exchange. (NULL => warn below here)
5198 s->n_preferred_kex = 0;
5199 for (i = 0; i < KEX_MAX; i++) {
5200 switch (ssh->cfg.ssh_kexlist[i]) {
5202 s->preferred_kex[s->n_preferred_kex++] =
5203 &ssh_diffiehellman_gex;
5206 s->preferred_kex[s->n_preferred_kex++] =
5207 &ssh_diffiehellman_group14;
5210 s->preferred_kex[s->n_preferred_kex++] =
5211 &ssh_diffiehellman_group1;
5214 s->preferred_kex[s->n_preferred_kex++] =
5218 /* Flag for later. Don't bother if it's the last in
5220 if (i < KEX_MAX - 1) {
5221 s->preferred_kex[s->n_preferred_kex++] = NULL;
5228 * Set up the preferred ciphers. (NULL => warn below here)
5230 s->n_preferred_ciphers = 0;
5231 for (i = 0; i < CIPHER_MAX; i++) {
5232 switch (ssh->cfg.ssh_cipherlist[i]) {
5233 case CIPHER_BLOWFISH:
5234 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5237 if (ssh->cfg.ssh2_des_cbc) {
5238 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5242 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5245 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5247 case CIPHER_ARCFOUR:
5248 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5251 /* Flag for later. Don't bother if it's the last in
5253 if (i < CIPHER_MAX - 1) {
5254 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5261 * Set up preferred compression.
5263 if (ssh->cfg.compression)
5264 s->preferred_comp = &ssh_zlib;
5266 s->preferred_comp = &ssh_comp_none;
5269 * Enable queueing of outgoing auth- or connection-layer
5270 * packets while we are in the middle of a key exchange.
5272 ssh->queueing = TRUE;
5275 * Flag that KEX is in progress.
5277 ssh->kex_in_progress = TRUE;
5280 * Construct and send our key exchange packet.
5282 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5283 for (i = 0; i < 16; i++)
5284 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5285 /* List key exchange algorithms. */
5286 ssh2_pkt_addstring_start(s->pktout);
5287 commalist_started = 0;
5288 for (i = 0; i < s->n_preferred_kex; i++) {
5289 const struct ssh_kexes *k = s->preferred_kex[i];
5290 if (!k) continue; /* warning flag */
5291 for (j = 0; j < k->nkexes; j++) {
5292 if (commalist_started)
5293 ssh2_pkt_addstring_str(s->pktout, ",");
5294 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5295 commalist_started = 1;
5298 /* List server host key algorithms. */
5299 ssh2_pkt_addstring_start(s->pktout);
5300 for (i = 0; i < lenof(hostkey_algs); i++) {
5301 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5302 if (i < lenof(hostkey_algs) - 1)
5303 ssh2_pkt_addstring_str(s->pktout, ",");
5305 /* List client->server encryption algorithms. */
5306 ssh2_pkt_addstring_start(s->pktout);
5307 commalist_started = 0;
5308 for (i = 0; i < s->n_preferred_ciphers; i++) {
5309 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5310 if (!c) continue; /* warning flag */
5311 for (j = 0; j < c->nciphers; j++) {
5312 if (commalist_started)
5313 ssh2_pkt_addstring_str(s->pktout, ",");
5314 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5315 commalist_started = 1;
5318 /* List server->client encryption algorithms. */
5319 ssh2_pkt_addstring_start(s->pktout);
5320 commalist_started = 0;
5321 for (i = 0; i < s->n_preferred_ciphers; i++) {
5322 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5323 if (!c) continue; /* warning flag */
5324 for (j = 0; j < c->nciphers; j++) {
5325 if (commalist_started)
5326 ssh2_pkt_addstring_str(s->pktout, ",");
5327 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5328 commalist_started = 1;
5331 /* List client->server MAC algorithms. */
5332 ssh2_pkt_addstring_start(s->pktout);
5333 for (i = 0; i < s->nmacs; i++) {
5334 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5335 if (i < s->nmacs - 1)
5336 ssh2_pkt_addstring_str(s->pktout, ",");
5338 /* List server->client MAC algorithms. */
5339 ssh2_pkt_addstring_start(s->pktout);
5340 for (i = 0; i < s->nmacs; i++) {
5341 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5342 if (i < s->nmacs - 1)
5343 ssh2_pkt_addstring_str(s->pktout, ",");
5345 /* List client->server compression algorithms. */
5346 ssh2_pkt_addstring_start(s->pktout);
5347 assert(lenof(compressions) > 1);
5348 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5349 for (i = 0; i < lenof(compressions); i++) {
5350 const struct ssh_compress *c = compressions[i];
5351 if (c != s->preferred_comp) {
5352 ssh2_pkt_addstring_str(s->pktout, ",");
5353 ssh2_pkt_addstring_str(s->pktout, c->name);
5356 /* List server->client compression algorithms. */
5357 ssh2_pkt_addstring_start(s->pktout);
5358 assert(lenof(compressions) > 1);
5359 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5360 for (i = 0; i < lenof(compressions); i++) {
5361 const struct ssh_compress *c = compressions[i];
5362 if (c != s->preferred_comp) {
5363 ssh2_pkt_addstring_str(s->pktout, ",");
5364 ssh2_pkt_addstring_str(s->pktout, c->name);
5367 /* List client->server languages. Empty list. */
5368 ssh2_pkt_addstring_start(s->pktout);
5369 /* List server->client languages. Empty list. */
5370 ssh2_pkt_addstring_start(s->pktout);
5371 /* First KEX packet does _not_ follow, because we're not that brave. */
5372 ssh2_pkt_addbool(s->pktout, FALSE);
5374 ssh2_pkt_adduint32(s->pktout, 0);
5377 s->our_kexinitlen = s->pktout->length - 5;
5378 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5379 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5381 ssh2_pkt_send_noqueue(ssh, s->pktout);
5387 * Now examine the other side's KEXINIT to see what we're up
5391 char *str, *preferred;
5394 if (pktin->type != SSH2_MSG_KEXINIT) {
5395 bombout(("expected key exchange packet from server"));
5399 ssh->hostkey = NULL;
5400 s->cscipher_tobe = NULL;
5401 s->sccipher_tobe = NULL;
5402 s->csmac_tobe = NULL;
5403 s->scmac_tobe = NULL;
5404 s->cscomp_tobe = NULL;
5405 s->sccomp_tobe = NULL;
5406 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5408 pktin->savedpos += 16; /* skip garbage cookie */
5409 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5412 for (i = 0; i < s->n_preferred_kex; i++) {
5413 const struct ssh_kexes *k = s->preferred_kex[i];
5417 for (j = 0; j < k->nkexes; j++) {
5418 if (!preferred) preferred = k->list[j]->name;
5419 if (in_commasep_string(k->list[j]->name, str, len)) {
5420 ssh->kex = k->list[j];
5429 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5430 str ? str : "(null)"));
5434 * Note that the server's guess is considered wrong if it doesn't match
5435 * the first algorithm in our list, even if it's still the algorithm
5438 s->guessok = first_in_commasep_string(preferred, str, len);
5439 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5440 for (i = 0; i < lenof(hostkey_algs); i++) {
5441 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5442 ssh->hostkey = hostkey_algs[i];
5446 s->guessok = s->guessok &&
5447 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5448 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5449 for (i = 0; i < s->n_preferred_ciphers; i++) {
5450 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5452 s->warn_cscipher = TRUE;
5454 for (j = 0; j < c->nciphers; j++) {
5455 if (in_commasep_string(c->list[j]->name, str, len)) {
5456 s->cscipher_tobe = c->list[j];
5461 if (s->cscipher_tobe)
5464 if (!s->cscipher_tobe) {
5465 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5466 str ? str : "(null)"));
5470 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5471 for (i = 0; i < s->n_preferred_ciphers; i++) {
5472 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5474 s->warn_sccipher = TRUE;
5476 for (j = 0; j < c->nciphers; j++) {
5477 if (in_commasep_string(c->list[j]->name, str, len)) {
5478 s->sccipher_tobe = c->list[j];
5483 if (s->sccipher_tobe)
5486 if (!s->sccipher_tobe) {
5487 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5488 str ? str : "(null)"));
5492 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5493 for (i = 0; i < s->nmacs; i++) {
5494 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5495 s->csmac_tobe = s->maclist[i];
5499 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5500 for (i = 0; i < s->nmacs; i++) {
5501 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5502 s->scmac_tobe = s->maclist[i];
5506 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5507 for (i = 0; i < lenof(compressions) + 1; i++) {
5508 const struct ssh_compress *c =
5509 i == 0 ? s->preferred_comp : compressions[i - 1];
5510 if (in_commasep_string(c->name, str, len)) {
5515 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5516 for (i = 0; i < lenof(compressions) + 1; i++) {
5517 const struct ssh_compress *c =
5518 i == 0 ? s->preferred_comp : compressions[i - 1];
5519 if (in_commasep_string(c->name, str, len)) {
5524 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5525 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5526 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5529 ssh_set_frozen(ssh, 1);
5530 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5532 ssh_dialog_callback, ssh);
5533 if (s->dlgret < 0) {
5537 bombout(("Unexpected data from server while"
5538 " waiting for user response"));
5541 } while (pktin || inlen > 0);
5542 s->dlgret = ssh->user_response;
5544 ssh_set_frozen(ssh, 0);
5545 if (s->dlgret == 0) {
5546 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5552 if (s->warn_cscipher) {
5553 ssh_set_frozen(ssh, 1);
5554 s->dlgret = askalg(ssh->frontend,
5555 "client-to-server cipher",
5556 s->cscipher_tobe->name,
5557 ssh_dialog_callback, ssh);
5558 if (s->dlgret < 0) {
5562 bombout(("Unexpected data from server while"
5563 " waiting for user response"));
5566 } while (pktin || inlen > 0);
5567 s->dlgret = ssh->user_response;
5569 ssh_set_frozen(ssh, 0);
5570 if (s->dlgret == 0) {
5571 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5577 if (s->warn_sccipher) {
5578 ssh_set_frozen(ssh, 1);
5579 s->dlgret = askalg(ssh->frontend,
5580 "server-to-client cipher",
5581 s->sccipher_tobe->name,
5582 ssh_dialog_callback, ssh);
5583 if (s->dlgret < 0) {
5587 bombout(("Unexpected data from server while"
5588 " waiting for user response"));
5591 } while (pktin || inlen > 0);
5592 s->dlgret = ssh->user_response;
5594 ssh_set_frozen(ssh, 0);
5595 if (s->dlgret == 0) {
5596 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5602 ssh->exhash = ssh->kex->hash->init();
5603 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5604 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5605 hash_string(ssh->kex->hash, ssh->exhash,
5606 s->our_kexinit, s->our_kexinitlen);
5607 sfree(s->our_kexinit);
5608 if (pktin->length > 5)
5609 hash_string(ssh->kex->hash, ssh->exhash,
5610 pktin->data + 5, pktin->length - 5);
5612 if (s->ignorepkt) /* first_kex_packet_follows */
5613 crWaitUntil(pktin); /* Ignore packet */
5616 if (ssh->kex->main_type == KEXTYPE_DH) {
5618 * Work out the number of bits of key we will need from the
5619 * key exchange. We start with the maximum key length of
5625 csbits = s->cscipher_tobe->keylen;
5626 scbits = s->sccipher_tobe->keylen;
5627 s->nbits = (csbits > scbits ? csbits : scbits);
5629 /* The keys only have hlen-bit entropy, since they're based on
5630 * a hash. So cap the key size at hlen bits. */
5631 if (s->nbits > ssh->kex->hash->hlen * 8)
5632 s->nbits = ssh->kex->hash->hlen * 8;
5635 * If we're doing Diffie-Hellman group exchange, start by
5636 * requesting a group.
5638 if (!ssh->kex->pdata) {
5639 logevent("Doing Diffie-Hellman group exchange");
5640 ssh->pkt_kctx = SSH2_PKTCTX_DHGEX;
5642 * Work out how big a DH group we will need to allow that
5645 s->pbits = 512 << ((s->nbits - 1) / 64);
5646 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5647 ssh2_pkt_adduint32(s->pktout, s->pbits);
5648 ssh2_pkt_send_noqueue(ssh, s->pktout);
5651 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5652 bombout(("expected key exchange group packet from server"));
5655 s->p = ssh2_pkt_getmp(pktin);
5656 s->g = ssh2_pkt_getmp(pktin);
5657 if (!s->p || !s->g) {
5658 bombout(("unable to read mp-ints from incoming group packet"));
5661 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5662 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5663 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5665 ssh->pkt_kctx = SSH2_PKTCTX_DHGROUP;
5666 ssh->kex_ctx = dh_setup_group(ssh->kex);
5667 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5668 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5669 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5670 ssh->kex->groupname);
5673 logeventf(ssh, "Doing Diffie-Hellman key exchange with hash %s",
5674 ssh->kex->hash->text_name);
5676 * Now generate and send e for Diffie-Hellman.
5678 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5679 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5680 s->pktout = ssh2_pkt_init(s->kex_init_value);
5681 ssh2_pkt_addmp(s->pktout, s->e);
5682 ssh2_pkt_send_noqueue(ssh, s->pktout);
5684 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5686 if (pktin->type != s->kex_reply_value) {
5687 bombout(("expected key exchange reply packet from server"));
5690 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5691 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5692 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5693 s->f = ssh2_pkt_getmp(pktin);
5695 bombout(("unable to parse key exchange reply packet"));
5698 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5700 s->K = dh_find_K(ssh->kex_ctx, s->f);
5702 /* We assume everything from now on will be quick, and it might
5703 * involve user interaction. */
5704 set_busy_status(ssh->frontend, BUSY_NOT);
5706 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5707 if (!ssh->kex->pdata) {
5708 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5709 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5710 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5712 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5713 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5715 dh_cleanup(ssh->kex_ctx);
5717 if (!ssh->kex->pdata) {
5722 logeventf(ssh, "Doing RSA key exchange with hash %s",
5723 ssh->kex->hash->text_name);
5724 ssh->pkt_kctx = SSH2_PKTCTX_RSAKEX;
5726 * RSA key exchange. First expect a KEXRSA_PUBKEY packet
5730 if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) {
5731 bombout(("expected RSA public key packet from server"));
5735 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5736 hash_string(ssh->kex->hash, ssh->exhash,
5737 s->hostkeydata, s->hostkeylen);
5738 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5742 ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen);
5743 s->rsakeydata = snewn(s->rsakeylen, char);
5744 memcpy(s->rsakeydata, keydata, s->rsakeylen);
5747 s->rsakey = ssh_rsakex_newkey(s->rsakeydata, s->rsakeylen);
5749 sfree(s->rsakeydata);
5750 bombout(("unable to parse RSA public key from server"));
5754 hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen);
5757 * Next, set up a shared secret K, of precisely KLEN -
5758 * 2*HLEN - 49 bits, where KLEN is the bit length of the
5759 * RSA key modulus and HLEN is the bit length of the hash
5763 int klen = ssh_rsakex_klen(s->rsakey);
5764 int nbits = klen - (2*ssh->kex->hash->hlen*8 + 49);
5766 unsigned char *kstr1, *kstr2, *outstr;
5767 int kstr1len, kstr2len, outstrlen;
5769 s->K = bn_power_2(nbits - 1);
5771 for (i = 0; i < nbits; i++) {
5773 byte = random_byte();
5775 bignum_set_bit(s->K, i, (byte >> (i & 7)) & 1);
5779 * Encode this as an mpint.
5781 kstr1 = ssh2_mpint_fmt(s->K, &kstr1len);
5782 kstr2 = snewn(kstr2len = 4 + kstr1len, unsigned char);
5783 PUT_32BIT(kstr2, kstr1len);
5784 memcpy(kstr2 + 4, kstr1, kstr1len);
5787 * Encrypt it with the given RSA key.
5789 outstrlen = (klen + 7) / 8;
5790 outstr = snewn(outstrlen, unsigned char);
5791 ssh_rsakex_encrypt(ssh->kex->hash, kstr2, kstr2len,
5792 outstr, outstrlen, s->rsakey);
5795 * And send it off in a return packet.
5797 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXRSA_SECRET);
5798 ssh2_pkt_addstring_start(s->pktout);
5799 ssh2_pkt_addstring_data(s->pktout, (char *)outstr, outstrlen);
5800 ssh2_pkt_send_noqueue(ssh, s->pktout);
5802 hash_string(ssh->kex->hash, ssh->exhash, outstr, outstrlen);
5809 ssh_rsakex_freekey(s->rsakey);
5812 if (pktin->type != SSH2_MSG_KEXRSA_DONE) {
5813 sfree(s->rsakeydata);
5814 bombout(("expected signature packet from server"));
5818 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5820 sfree(s->rsakeydata);
5823 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
5824 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
5825 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
5827 ssh->kex_ctx = NULL;
5830 debug(("Exchange hash is:\n"));
5831 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
5835 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5836 (char *)s->exchange_hash,
5837 ssh->kex->hash->hlen)) {
5838 bombout(("Server's host key did not match the signature supplied"));
5843 * Authenticate remote host: verify host key. (We've already
5844 * checked the signature of the exchange hash.)
5846 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5847 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5848 ssh_set_frozen(ssh, 1);
5849 s->dlgret = verify_ssh_host_key(ssh->frontend,
5850 ssh->savedhost, ssh->savedport,
5851 ssh->hostkey->keytype, s->keystr,
5853 ssh_dialog_callback, ssh);
5854 if (s->dlgret < 0) {
5858 bombout(("Unexpected data from server while waiting"
5859 " for user host key response"));
5862 } while (pktin || inlen > 0);
5863 s->dlgret = ssh->user_response;
5865 ssh_set_frozen(ssh, 0);
5866 if (s->dlgret == 0) {
5867 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5871 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5872 logevent("Host key fingerprint is:");
5873 logevent(s->fingerprint);
5875 sfree(s->fingerprint);
5877 ssh->hostkey->freekey(s->hkey);
5880 * The exchange hash from the very first key exchange is also
5881 * the session id, used in session key construction and
5884 if (!s->got_session_id) {
5885 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
5886 memcpy(ssh->v2_session_id, s->exchange_hash,
5887 sizeof(s->exchange_hash));
5888 ssh->v2_session_id_len = ssh->kex->hash->hlen;
5889 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
5890 s->got_session_id = TRUE;
5894 * Send SSH2_MSG_NEWKEYS.
5896 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5897 ssh2_pkt_send_noqueue(ssh, s->pktout);
5898 ssh->outgoing_data_size = 0; /* start counting from here */
5901 * We've sent client NEWKEYS, so create and initialise
5902 * client-to-server session keys.
5904 if (ssh->cs_cipher_ctx)
5905 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5906 ssh->cscipher = s->cscipher_tobe;
5907 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5909 if (ssh->cs_mac_ctx)
5910 ssh->csmac->free_context(ssh->cs_mac_ctx);
5911 ssh->csmac = s->csmac_tobe;
5912 ssh->cs_mac_ctx = ssh->csmac->make_context();
5914 if (ssh->cs_comp_ctx)
5915 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5916 ssh->cscomp = s->cscomp_tobe;
5917 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5920 * Set IVs on client-to-server keys. Here we use the exchange
5921 * hash from the _first_ key exchange.
5924 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
5925 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5926 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
5927 assert((ssh->cscipher->keylen+7) / 8 <=
5928 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5929 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5930 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
5931 assert(ssh->cscipher->blksize <=
5932 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5933 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5934 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
5935 assert(ssh->csmac->len <=
5936 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5937 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5938 memset(keyspace, 0, sizeof(keyspace));
5941 logeventf(ssh, "Initialised %.200s client->server encryption",
5942 ssh->cscipher->text_name);
5943 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5944 ssh->csmac->text_name);
5945 if (ssh->cscomp->text_name)
5946 logeventf(ssh, "Initialised %s compression",
5947 ssh->cscomp->text_name);
5950 * Now our end of the key exchange is complete, we can send all
5951 * our queued higher-layer packets.
5953 ssh->queueing = FALSE;
5954 ssh2_pkt_queuesend(ssh);
5957 * Expect SSH2_MSG_NEWKEYS from server.
5960 if (pktin->type != SSH2_MSG_NEWKEYS) {
5961 bombout(("expected new-keys packet from server"));
5964 ssh->incoming_data_size = 0; /* start counting from here */
5967 * We've seen server NEWKEYS, so create and initialise
5968 * server-to-client session keys.
5970 if (ssh->sc_cipher_ctx)
5971 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5972 ssh->sccipher = s->sccipher_tobe;
5973 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5975 if (ssh->sc_mac_ctx)
5976 ssh->scmac->free_context(ssh->sc_mac_ctx);
5977 ssh->scmac = s->scmac_tobe;
5978 ssh->sc_mac_ctx = ssh->scmac->make_context();
5980 if (ssh->sc_comp_ctx)
5981 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5982 ssh->sccomp = s->sccomp_tobe;
5983 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5986 * Set IVs on server-to-client keys. Here we use the exchange
5987 * hash from the _first_ key exchange.
5990 unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS];
5991 assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5992 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
5993 assert((ssh->sccipher->keylen+7) / 8 <=
5994 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5995 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5996 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
5997 assert(ssh->sccipher->blksize <=
5998 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
5999 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
6000 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
6001 assert(ssh->scmac->len <=
6002 ssh->kex->hash->hlen * SSH2_MKKEY_ITERS);
6003 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
6004 memset(keyspace, 0, sizeof(keyspace));
6006 logeventf(ssh, "Initialised %.200s server->client encryption",
6007 ssh->sccipher->text_name);
6008 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
6009 ssh->scmac->text_name);
6010 if (ssh->sccomp->text_name)
6011 logeventf(ssh, "Initialised %s decompression",
6012 ssh->sccomp->text_name);
6015 * Free shared secret.
6020 * Key exchange is over. Loop straight back round if we have a
6021 * deferred rekey reason.
6023 if (ssh->deferred_rekey_reason) {
6024 logevent(ssh->deferred_rekey_reason);
6026 ssh->deferred_rekey_reason = NULL;
6027 goto begin_key_exchange;
6031 * Otherwise, schedule a timer for our next rekey.
6033 ssh->kex_in_progress = FALSE;
6034 ssh->last_rekey = GETTICKCOUNT();
6035 if (ssh->cfg.ssh_rekey_time != 0)
6036 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6040 * If this is the first key exchange phase, we must pass the
6041 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
6042 * wants to see it but because it will need time to initialise
6043 * itself before it sees an actual packet. In subsequent key
6044 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
6045 * it would only confuse the layer above.
6047 if (s->activated_authconn) {
6050 s->activated_authconn = TRUE;
6053 * Now we're encrypting. Begin returning 1 to the protocol main
6054 * function so that other things can run on top of the
6055 * transport. If we ever see a KEXINIT, we must go back to the
6058 * We _also_ go back to the start if we see pktin==NULL and
6059 * inlen==-1, because this is a special signal meaning
6060 * `initiate client-driven rekey', and `in' contains a message
6061 * giving the reason for the rekey.
6063 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
6064 (!pktin && inlen == -1))) {
6069 logevent("Server initiated key re-exchange");
6072 * Special case: if the server bug is set that doesn't
6073 * allow rekeying, we give a different log message and
6074 * continue waiting. (If such a server _initiates_ a rekey,
6075 * we process it anyway!)
6077 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
6078 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
6080 /* Reset the counters, so that at least this message doesn't
6081 * hit the event log _too_ often. */
6082 ssh->outgoing_data_size = 0;
6083 ssh->incoming_data_size = 0;
6084 if (ssh->cfg.ssh_rekey_time != 0) {
6086 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
6089 goto wait_for_rekey; /* this is utterly horrid */
6091 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
6094 goto begin_key_exchange;
6100 * Add data to an SSH-2 channel output buffer.
6102 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
6105 bufchain_add(&c->v.v2.outbuffer, buf, len);
6109 * Attempt to send data on an SSH-2 channel.
6111 static int ssh2_try_send(struct ssh_channel *c)
6114 struct Packet *pktout;
6116 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
6119 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
6120 if ((unsigned)len > c->v.v2.remwindow)
6121 len = c->v.v2.remwindow;
6122 if ((unsigned)len > c->v.v2.remmaxpkt)
6123 len = c->v.v2.remmaxpkt;
6124 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
6125 ssh2_pkt_adduint32(pktout, c->remoteid);
6126 ssh2_pkt_addstring_start(pktout);
6127 dont_log_data(ssh, pktout, PKTLOG_OMIT);
6128 ssh2_pkt_addstring_data(pktout, data, len);
6129 end_log_omission(ssh, pktout);
6130 ssh2_pkt_send(ssh, pktout);
6131 bufchain_consume(&c->v.v2.outbuffer, len);
6132 c->v.v2.remwindow -= len;
6136 * After having sent as much data as we can, return the amount
6139 return bufchain_size(&c->v.v2.outbuffer);
6142 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
6146 return; /* don't send on closing channels */
6147 bufsize = ssh2_try_send(c);
6150 case CHAN_MAINSESSION:
6151 /* stdin need not receive an unthrottle
6152 * notification since it will be polled */
6155 x11_unthrottle(c->u.x11.s);
6158 /* agent sockets are request/response and need no
6159 * buffer management */
6162 pfd_unthrottle(c->u.pfd.s);
6169 * Potentially enlarge the window on an SSH-2 channel.
6171 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
6176 * Never send WINDOW_ADJUST for a channel that the remote side
6177 * already thinks it's closed; there's no point, since it won't
6178 * be sending any more data anyway.
6184 * Only send a WINDOW_ADJUST if there's significantly more window
6185 * available than the other end thinks there is. This saves us
6186 * sending a WINDOW_ADJUST for every character in a shell session.
6188 * "Significant" is arbitrarily defined as half the window size.
6190 if (newwin > c->v.v2.locwindow * 2) {
6191 struct Packet *pktout;
6193 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
6194 ssh2_pkt_adduint32(pktout, c->remoteid);
6195 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
6196 ssh2_pkt_send(ssh, pktout);
6197 c->v.v2.locwindow = newwin;
6201 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
6203 unsigned i = ssh_pkt_getuint32(pktin);
6204 struct ssh_channel *c;
6205 c = find234(ssh->channels, &i, ssh_channelfind);
6206 if (c && !c->closes) {
6207 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
6208 ssh2_try_send_and_unthrottle(c);
6212 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
6216 unsigned i = ssh_pkt_getuint32(pktin);
6217 struct ssh_channel *c;
6218 c = find234(ssh->channels, &i, ssh_channelfind);
6220 return; /* nonexistent channel */
6221 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
6222 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
6223 return; /* extended but not stderr */
6224 ssh_pkt_getstring(pktin, &data, &length);
6227 c->v.v2.locwindow -= length;
6229 case CHAN_MAINSESSION:
6231 from_backend(ssh->frontend, pktin->type ==
6232 SSH2_MSG_CHANNEL_EXTENDED_DATA,
6236 bufsize = x11_send(c->u.x11.s, data, length);
6239 bufsize = pfd_send(c->u.pfd.s, data, length);
6242 while (length > 0) {
6243 if (c->u.a.lensofar < 4) {
6244 unsigned int l = min(4 - c->u.a.lensofar,
6246 memcpy(c->u.a.msglen + c->u.a.lensofar,
6250 c->u.a.lensofar += l;
6252 if (c->u.a.lensofar == 4) {
6254 4 + GET_32BIT(c->u.a.msglen);
6255 c->u.a.message = snewn(c->u.a.totallen,
6257 memcpy(c->u.a.message, c->u.a.msglen, 4);
6259 if (c->u.a.lensofar >= 4 && length > 0) {
6261 min(c->u.a.totallen - c->u.a.lensofar,
6263 memcpy(c->u.a.message + c->u.a.lensofar,
6267 c->u.a.lensofar += l;
6269 if (c->u.a.lensofar == c->u.a.totallen) {
6272 if (agent_query(c->u.a.message,
6275 ssh_agentf_callback, c))
6276 ssh_agentf_callback(c, reply, replylen);
6277 sfree(c->u.a.message);
6278 c->u.a.lensofar = 0;
6285 * If we are not buffering too much data,
6286 * enlarge the window again at the remote side.
6287 * If we are buffering too much, we may still
6288 * need to adjust the window if the server's
6291 ssh2_set_window(c, bufsize < OUR_V2_WINSIZE ?
6292 OUR_V2_WINSIZE - bufsize : 0);
6296 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6298 unsigned i = ssh_pkt_getuint32(pktin);
6299 struct ssh_channel *c;
6301 c = find234(ssh->channels, &i, ssh_channelfind);
6303 return; /* nonexistent channel */
6305 if (c->type == CHAN_X11) {
6307 * Remote EOF on an X11 channel means we should
6308 * wrap up and close the channel ourselves.
6310 x11_close(c->u.x11.s);
6312 } else if (c->type == CHAN_AGENT) {
6314 } else if (c->type == CHAN_SOCKDATA) {
6315 pfd_close(c->u.pfd.s);
6320 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6322 unsigned i = ssh_pkt_getuint32(pktin);
6323 struct ssh_channel *c;
6324 struct Packet *pktout;
6326 c = find234(ssh->channels, &i, ssh_channelfind);
6327 if (!c || c->halfopen) {
6328 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6329 c ? "half-open" : "nonexistent", i));
6332 /* Do pre-close processing on the channel. */
6334 case CHAN_MAINSESSION:
6335 ssh->mainchan = NULL;
6336 update_specials_menu(ssh->frontend);
6339 if (c->u.x11.s != NULL)
6340 x11_close(c->u.x11.s);
6347 if (c->u.pfd.s != NULL)
6348 pfd_close(c->u.pfd.s);
6352 if (c->closes == 0) {
6353 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6354 ssh2_pkt_adduint32(pktout, c->remoteid);
6355 ssh2_pkt_send(ssh, pktout);
6357 del234(ssh->channels, c);
6358 bufchain_clear(&c->v.v2.outbuffer);
6362 * See if that was the last channel left open.
6363 * (This is only our termination condition if we're
6364 * not running in -N mode.)
6366 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6368 * We used to send SSH_MSG_DISCONNECT here,
6369 * because I'd believed that _every_ conforming
6370 * SSH-2 connection had to end with a disconnect
6371 * being sent by at least one side; apparently
6372 * I was wrong and it's perfectly OK to
6373 * unceremoniously slam the connection shut
6374 * when you're done, and indeed OpenSSH feels
6375 * this is more polite than sending a
6376 * DISCONNECT. So now we don't.
6378 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6382 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6384 unsigned i = ssh_pkt_getuint32(pktin);
6385 struct ssh_channel *c;
6386 struct Packet *pktout;
6388 c = find234(ssh->channels, &i, ssh_channelfind);
6390 return; /* nonexistent channel */
6391 if (c->type != CHAN_SOCKDATA_DORMANT)
6392 return; /* dunno why they're confirming this */
6393 c->remoteid = ssh_pkt_getuint32(pktin);
6394 c->halfopen = FALSE;
6395 c->type = CHAN_SOCKDATA;
6396 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6397 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6399 pfd_confirm(c->u.pfd.s);
6402 * We have a pending close on this channel,
6403 * which we decided on before the server acked
6404 * the channel open. So now we know the
6405 * remoteid, we can close it again.
6407 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6408 ssh2_pkt_adduint32(pktout, c->remoteid);
6409 ssh2_pkt_send(ssh, pktout);
6413 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6415 static const char *const reasons[] = {
6416 "<unknown reason code>",
6417 "Administratively prohibited",
6419 "Unknown channel type",
6420 "Resource shortage",
6422 unsigned i = ssh_pkt_getuint32(pktin);
6423 unsigned reason_code;
6424 char *reason_string;
6426 struct ssh_channel *c;
6427 c = find234(ssh->channels, &i, ssh_channelfind);
6429 return; /* nonexistent channel */
6430 if (c->type != CHAN_SOCKDATA_DORMANT)
6431 return; /* dunno why they're failing this */
6433 reason_code = ssh_pkt_getuint32(pktin);
6434 if (reason_code >= lenof(reasons))
6435 reason_code = 0; /* ensure reasons[reason_code] in range */
6436 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6437 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6438 reasons[reason_code], reason_length, reason_string);
6440 pfd_close(c->u.pfd.s);
6442 del234(ssh->channels, c);
6446 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6450 int typelen, want_reply;
6451 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6452 struct ssh_channel *c;
6453 struct Packet *pktout;
6455 localid = ssh_pkt_getuint32(pktin);
6456 ssh_pkt_getstring(pktin, &type, &typelen);
6457 want_reply = ssh2_pkt_getbool(pktin);
6460 * First, check that the channel exists. Otherwise,
6461 * we can instantly disconnect with a rude message.
6463 c = find234(ssh->channels, &localid, ssh_channelfind);
6465 char *buf = dupprintf("Received channel request for nonexistent"
6466 " channel %d", localid);
6467 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6473 * Having got the channel number, we now look at
6474 * the request type string to see if it's something
6477 if (c == ssh->mainchan) {
6479 * We recognise "exit-status" and "exit-signal" on
6480 * the primary channel.
6482 if (typelen == 11 &&
6483 !memcmp(type, "exit-status", 11)) {
6485 ssh->exitcode = ssh_pkt_getuint32(pktin);
6486 logeventf(ssh, "Server sent command exit status %d",
6488 reply = SSH2_MSG_CHANNEL_SUCCESS;
6490 } else if (typelen == 11 &&
6491 !memcmp(type, "exit-signal", 11)) {
6493 int is_plausible = TRUE, is_int = FALSE;
6494 char *fmt_sig = "", *fmt_msg = "";
6496 int msglen = 0, core = FALSE;
6497 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6498 * provide an `int' for the signal, despite its
6499 * having been a `string' in the drafts since at
6500 * least 2001. (Fixed in session.c 1.147.) Try to
6501 * infer which we can safely parse it as. */
6503 unsigned char *p = pktin->body +
6505 long len = pktin->length - pktin->savedpos;
6506 unsigned long num = GET_32BIT(p); /* what is it? */
6507 /* If it's 0, it hardly matters; assume string */
6511 int maybe_int = FALSE, maybe_str = FALSE;
6512 #define CHECK_HYPOTHESIS(offset, result) \
6515 if (q >= 0 && q+4 <= len) { \
6516 q = q + 4 + GET_32BIT(p+q); \
6517 if (q >= 0 && q+4 <= len && \
6518 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6522 CHECK_HYPOTHESIS(4+1, maybe_int);
6523 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6524 #undef CHECK_HYPOTHESIS
6525 if (maybe_int && !maybe_str)
6527 else if (!maybe_int && maybe_str)
6530 /* Crikey. Either or neither. Panic. */
6531 is_plausible = FALSE;
6534 ssh->exitcode = 128; /* means `unknown signal' */
6537 /* Old non-standard OpenSSH. */
6538 int signum = ssh_pkt_getuint32(pktin);
6539 fmt_sig = dupprintf(" %d", signum);
6540 ssh->exitcode = 128 + signum;
6542 /* As per the drafts. */
6545 ssh_pkt_getstring(pktin, &sig, &siglen);
6546 /* Signal name isn't supposed to be blank, but
6547 * let's cope gracefully if it is. */
6549 fmt_sig = dupprintf(" \"%.*s\"",
6554 * Really hideous method of translating the
6555 * signal description back into a locally
6556 * meaningful number.
6561 #define TRANSLATE_SIGNAL(s) \
6562 else if (siglen == lenof(#s)-1 && !memcmp(sig, #s, siglen)) \
6563 ssh->exitcode = 128 + SIG ## s
6565 TRANSLATE_SIGNAL(ABRT);
6568 TRANSLATE_SIGNAL(ALRM);
6571 TRANSLATE_SIGNAL(FPE);
6574 TRANSLATE_SIGNAL(HUP);
6577 TRANSLATE_SIGNAL(ILL);
6580 TRANSLATE_SIGNAL(INT);
6583 TRANSLATE_SIGNAL(KILL);
6586 TRANSLATE_SIGNAL(PIPE);
6589 TRANSLATE_SIGNAL(QUIT);
6592 TRANSLATE_SIGNAL(SEGV);
6595 TRANSLATE_SIGNAL(TERM);
6598 TRANSLATE_SIGNAL(USR1);
6601 TRANSLATE_SIGNAL(USR2);
6603 #undef TRANSLATE_SIGNAL
6605 ssh->exitcode = 128;
6607 core = ssh2_pkt_getbool(pktin);
6608 ssh_pkt_getstring(pktin, &msg, &msglen);
6610 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6612 /* ignore lang tag */
6613 } /* else don't attempt to parse */
6614 logeventf(ssh, "Server exited on signal%s%s%s",
6615 fmt_sig, core ? " (core dumped)" : "",
6617 if (*fmt_sig) sfree(fmt_sig);
6618 if (*fmt_msg) sfree(fmt_msg);
6619 reply = SSH2_MSG_CHANNEL_SUCCESS;
6624 * This is a channel request we don't know
6625 * about, so we now either ignore the request
6626 * or respond with CHANNEL_FAILURE, depending
6629 reply = SSH2_MSG_CHANNEL_FAILURE;
6632 pktout = ssh2_pkt_init(reply);
6633 ssh2_pkt_adduint32(pktout, c->remoteid);
6634 ssh2_pkt_send(ssh, pktout);
6638 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6641 int typelen, want_reply;
6642 struct Packet *pktout;
6644 ssh_pkt_getstring(pktin, &type, &typelen);
6645 want_reply = ssh2_pkt_getbool(pktin);
6648 * We currently don't support any global requests
6649 * at all, so we either ignore the request or
6650 * respond with REQUEST_FAILURE, depending on
6654 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6655 ssh2_pkt_send(ssh, pktout);
6659 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6667 struct ssh_channel *c;
6668 unsigned remid, winsize, pktsize;
6669 struct Packet *pktout;
6671 ssh_pkt_getstring(pktin, &type, &typelen);
6672 c = snew(struct ssh_channel);
6675 remid = ssh_pkt_getuint32(pktin);
6676 winsize = ssh_pkt_getuint32(pktin);
6677 pktsize = ssh_pkt_getuint32(pktin);
6679 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6682 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6683 addrstr = snewn(peeraddrlen+1, char);
6684 memcpy(addrstr, peeraddr, peeraddrlen);
6685 addrstr[peeraddrlen] = '\0';
6686 peerport = ssh_pkt_getuint32(pktin);
6688 logeventf(ssh, "Received X11 connect request from %s:%d",
6691 if (!ssh->X11_fwd_enabled)
6692 error = "X11 forwarding is not enabled";
6693 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6694 ssh->x11auth, addrstr, peerport,
6695 &ssh->cfg) != NULL) {
6696 error = "Unable to open an X11 connection";
6698 logevent("Opening X11 forward connection succeeded");
6703 } else if (typelen == 15 &&
6704 !memcmp(type, "forwarded-tcpip", 15)) {
6705 struct ssh_rportfwd pf, *realpf;
6708 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6709 pf.sport = ssh_pkt_getuint32(pktin);
6710 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6711 peerport = ssh_pkt_getuint32(pktin);
6712 realpf = find234(ssh->rportfwds, &pf, NULL);
6713 logeventf(ssh, "Received remote port %d open request "
6714 "from %s:%d", pf.sport, peeraddr, peerport);
6715 if (realpf == NULL) {
6716 error = "Remote port is not recognised";
6718 const char *e = pfd_newconnect(&c->u.pfd.s,
6722 realpf->pfrec->addressfamily);
6723 logeventf(ssh, "Attempting to forward remote port to "
6724 "%s:%d", realpf->dhost, realpf->dport);
6726 logeventf(ssh, "Port open failed: %s", e);
6727 error = "Port open failed";
6729 logevent("Forwarded port opened successfully");
6730 c->type = CHAN_SOCKDATA;
6733 } else if (typelen == 22 &&
6734 !memcmp(type, "auth-agent@openssh.com", 22)) {
6735 if (!ssh->agentfwd_enabled)
6736 error = "Agent forwarding is not enabled";
6738 c->type = CHAN_AGENT; /* identify channel type */
6739 c->u.a.lensofar = 0;
6742 error = "Unsupported channel type requested";
6745 c->remoteid = remid;
6746 c->halfopen = FALSE;
6748 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6749 ssh2_pkt_adduint32(pktout, c->remoteid);
6750 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6751 ssh2_pkt_addstring(pktout, error);
6752 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6753 ssh2_pkt_send(ssh, pktout);
6754 logeventf(ssh, "Rejected channel open: %s", error);
6757 c->localid = alloc_channel_id(ssh);
6759 c->v.v2.locwindow = OUR_V2_WINSIZE;
6760 c->v.v2.remwindow = winsize;
6761 c->v.v2.remmaxpkt = pktsize;
6762 bufchain_init(&c->v.v2.outbuffer);
6763 add234(ssh->channels, c);
6764 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6765 ssh2_pkt_adduint32(pktout, c->remoteid);
6766 ssh2_pkt_adduint32(pktout, c->localid);
6767 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6768 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6769 ssh2_pkt_send(ssh, pktout);
6774 * Buffer banner messages for later display at some convenient point.
6776 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6778 /* Arbitrary limit to prevent unbounded inflation of buffer */
6779 if (bufchain_size(&ssh->banner) <= 131072) {
6780 char *banner = NULL;
6782 ssh_pkt_getstring(pktin, &banner, &size);
6784 bufchain_add(&ssh->banner, banner, size);
6788 /* Helper function to deal with sending tty modes for "pty-req" */
6789 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6791 struct Packet *pktout = (struct Packet *)data;
6793 unsigned int arg = 0;
6794 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6795 if (i == lenof(ssh_ttymodes)) return;
6796 switch (ssh_ttymodes[i].type) {
6798 arg = ssh_tty_parse_specchar(val);
6801 arg = ssh_tty_parse_boolean(val);
6804 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6805 ssh2_pkt_adduint32(pktout, arg);
6809 * Handle the SSH-2 userauth and connection layers.
6811 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6812 struct Packet *pktin)
6814 struct do_ssh2_authconn_state {
6817 AUTH_TYPE_PUBLICKEY,
6818 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6819 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6821 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6822 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6824 int done_service_req;
6825 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6826 int tried_pubkey_config, done_agent;
6827 int kbd_inter_refused;
6829 prompts_t *cur_prompt;
6834 void *publickey_blob;
6835 int publickey_bloblen;
6836 int publickey_encrypted;
6837 char *publickey_algorithm;
6838 char *publickey_comment;
6839 unsigned char agent_request[5], *agent_response, *agentp;
6840 int agent_responselen;
6841 unsigned char *pkblob_in_agent;
6843 char *pkblob, *alg, *commentp;
6844 int pklen, alglen, commentlen;
6845 int siglen, retlen, len;
6846 char *q, *agentreq, *ret;
6848 int num_env, env_left, env_ok;
6849 struct Packet *pktout;
6851 crState(do_ssh2_authconn_state);
6853 crBegin(ssh->do_ssh2_authconn_crstate);
6855 s->done_service_req = FALSE;
6856 s->we_are_in = FALSE;
6857 if (!ssh->cfg.ssh_no_userauth) {
6859 * Request userauth protocol, and await a response to it.
6861 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6862 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6863 ssh2_pkt_send(ssh, s->pktout);
6864 crWaitUntilV(pktin);
6865 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6866 s->done_service_req = TRUE;
6868 if (!s->done_service_req) {
6870 * Request connection protocol directly, without authentication.
6872 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6873 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6874 ssh2_pkt_send(ssh, s->pktout);
6875 crWaitUntilV(pktin);
6876 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6877 s->we_are_in = TRUE; /* no auth required */
6879 bombout(("Server refused service request"));
6884 /* Arrange to be able to deal with any BANNERs that come in.
6885 * (We do this now as packets may come in during the next bit.) */
6886 bufchain_init(&ssh->banner);
6887 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6888 ssh2_msg_userauth_banner;
6891 * Misc one-time setup for authentication.
6893 s->publickey_blob = NULL;
6894 if (!s->we_are_in) {
6897 * Load the public half of any configured public key file
6900 if (!filename_is_null(ssh->cfg.keyfile)) {
6902 logeventf(ssh, "Reading private key file \"%.150s\"",
6903 filename_to_str(&ssh->cfg.keyfile));
6904 keytype = key_type(&ssh->cfg.keyfile);
6905 if (keytype == SSH_KEYTYPE_SSH2) {
6908 ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6909 &s->publickey_algorithm,
6910 &s->publickey_bloblen,
6911 &s->publickey_comment, &error);
6912 if (s->publickey_blob) {
6913 s->publickey_encrypted =
6914 ssh2_userkey_encrypted(&ssh->cfg.keyfile, NULL);
6917 logeventf(ssh, "Unable to load private key (%s)",
6919 msgbuf = dupprintf("Unable to load private key file "
6920 "\"%.150s\" (%s)\r\n",
6921 filename_to_str(&ssh->cfg.keyfile),
6923 c_write_str(ssh, msgbuf);
6928 logeventf(ssh, "Unable to use this key file (%s)",
6929 key_type_to_str(keytype));
6930 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6932 filename_to_str(&ssh->cfg.keyfile),
6933 key_type_to_str(keytype));
6934 c_write_str(ssh, msgbuf);
6936 s->publickey_blob = NULL;
6941 * Find out about any keys Pageant has (but if there's a
6942 * public key configured, filter out all others).
6945 s->agent_response = NULL;
6946 s->pkblob_in_agent = NULL;
6947 if (ssh->cfg.tryagent && agent_exists()) {
6951 logevent("Pageant is running. Requesting keys.");
6953 /* Request the keys held by the agent. */
6954 PUT_32BIT(s->agent_request, 1);
6955 s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6956 if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen,
6957 ssh_agent_callback, ssh)) {
6961 bombout(("Unexpected data from server while"
6962 " waiting for agent response"));
6965 } while (pktin || inlen > 0);
6966 r = ssh->agent_response;
6967 s->agent_responselen = ssh->agent_response_len;
6969 s->agent_response = (unsigned char *) r;
6970 if (s->agent_response && s->agent_responselen >= 5 &&
6971 s->agent_response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6974 p = s->agent_response + 5;
6975 s->nkeys = GET_32BIT(p);
6977 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6978 if (s->publickey_blob) {
6979 /* See if configured key is in agent. */
6980 for (keyi = 0; keyi < s->nkeys; keyi++) {
6981 s->pklen = GET_32BIT(p);
6982 if (s->pklen == s->publickey_bloblen &&
6983 !memcmp(p+4, s->publickey_blob,
6984 s->publickey_bloblen)) {
6985 logeventf(ssh, "Pageant key #%d matches "
6986 "configured key file", keyi);
6988 s->pkblob_in_agent = p;
6992 p += GET_32BIT(p) + 4; /* comment */
6994 if (!s->pkblob_in_agent) {
6995 logevent("Configured key file not in Pageant");
7005 * We repeat this whole loop, including the username prompt,
7006 * until we manage a successful authentication. If the user
7007 * types the wrong _password_, they can be sent back to the
7008 * beginning to try another username, if this is configured on.
7009 * (If they specify a username in the config, they are never
7010 * asked, even if they do give a wrong password.)
7012 * I think this best serves the needs of
7014 * - the people who have no configuration, no keys, and just
7015 * want to try repeated (username,password) pairs until they
7016 * type both correctly
7018 * - people who have keys and configuration but occasionally
7019 * need to fall back to passwords
7021 * - people with a key held in Pageant, who might not have
7022 * logged in to a particular machine before; so they want to
7023 * type a username, and then _either_ their key will be
7024 * accepted, _or_ they will type a password. If they mistype
7025 * the username they will want to be able to get back and
7028 s->username[0] = '\0';
7029 s->got_username = FALSE;
7030 while (!s->we_are_in) {
7034 if (s->got_username && !ssh->cfg.change_username) {
7036 * We got a username last time round this loop, and
7037 * with change_username turned off we don't try to get
7040 } else if (!*ssh->cfg.username) {
7041 int ret; /* need not be kept over crReturn */
7042 s->cur_prompt = new_prompts(ssh->frontend);
7043 s->cur_prompt->to_server = TRUE;
7044 s->cur_prompt->name = dupstr("SSH login name");
7045 add_prompt(s->cur_prompt, dupstr("login as: "), TRUE,
7046 lenof(s->username));
7047 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7050 crWaitUntilV(!pktin);
7051 ret = get_userpass_input(s->cur_prompt, in, inlen);
7056 * get_userpass_input() failed to get a username.
7059 free_prompts(s->cur_prompt);
7060 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
7063 memcpy(s->username, s->cur_prompt->prompts[0]->result,
7064 lenof(s->username));
7065 free_prompts(s->cur_prompt);
7068 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
7069 s->username[sizeof(s->username)-1] = '\0';
7070 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7071 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
7072 c_write_str(ssh, stuff);
7076 s->got_username = TRUE;
7079 * Send an authentication request using method "none": (a)
7080 * just in case it succeeds, and (b) so that we know what
7081 * authentication methods we can usefully try next.
7083 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7085 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7086 ssh2_pkt_addstring(s->pktout, s->username);
7087 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
7088 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7089 ssh2_pkt_send(ssh, s->pktout);
7090 s->type = AUTH_TYPE_NONE;
7092 s->we_are_in = FALSE;
7094 s->tried_pubkey_config = FALSE;
7095 s->kbd_inter_refused = FALSE;
7097 /* Reset agent request state. */
7098 s->done_agent = FALSE;
7099 if (s->agent_response) {
7100 if (s->pkblob_in_agent) {
7101 s->agentp = s->pkblob_in_agent;
7103 s->agentp = s->agent_response + 5 + 4;
7110 * Wait for the result of the last authentication request.
7113 crWaitUntilV(pktin);
7115 * Now is a convenient point to spew any banner material
7116 * that we've accumulated. (This should ensure that when
7117 * we exit the auth loop, we haven't any left to deal
7121 int size = bufchain_size(&ssh->banner);
7123 * Don't show the banner if we're operating in
7124 * non-verbose non-interactive mode. (It's probably
7125 * a script, which means nobody will read the
7126 * banner _anyway_, and moreover the printing of
7127 * the banner will screw up processing on the
7128 * output of (say) plink.)
7130 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
7131 char *banner = snewn(size, char);
7132 bufchain_fetch(&ssh->banner, banner, size);
7133 c_write_untrusted(ssh, banner, size);
7136 bufchain_clear(&ssh->banner);
7138 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
7139 logevent("Access granted");
7140 s->we_are_in = TRUE;
7144 if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
7145 bombout(("Strange packet received during authentication: "
7146 "type %d", pktin->type));
7153 * OK, we're now sitting on a USERAUTH_FAILURE message, so
7154 * we can look at the string in it and know what we can
7155 * helpfully try next.
7157 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
7160 ssh_pkt_getstring(pktin, &methods, &methlen);
7161 if (!ssh2_pkt_getbool(pktin)) {
7163 * We have received an unequivocal Access
7164 * Denied. This can translate to a variety of
7167 * - if we'd just tried "none" authentication,
7168 * it's not worth printing anything at all
7170 * - if we'd just tried a public key _offer_,
7171 * the message should be "Server refused our
7172 * key" (or no message at all if the key
7173 * came from Pageant)
7175 * - if we'd just tried anything else, the
7176 * message really should be "Access denied".
7178 * Additionally, if we'd just tried password
7179 * authentication, we should break out of this
7180 * whole loop so as to go back to the username
7181 * prompt (iff we're configured to allow
7182 * username change attempts).
7184 if (s->type == AUTH_TYPE_NONE) {
7186 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
7187 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
7188 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
7189 c_write_str(ssh, "Server refused our key\r\n");
7190 logevent("Server refused public key");
7191 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
7192 /* server declined keyboard-interactive; ignore */
7194 c_write_str(ssh, "Access denied\r\n");
7195 logevent("Access denied");
7196 if (s->type == AUTH_TYPE_PASSWORD &&
7197 ssh->cfg.change_username) {
7198 /* XXX perhaps we should allow
7199 * keyboard-interactive to do this too? */
7200 s->we_are_in = FALSE;
7205 c_write_str(ssh, "Further authentication required\r\n");
7206 logevent("Further authentication required");
7210 in_commasep_string("publickey", methods, methlen);
7212 in_commasep_string("password", methods, methlen);
7213 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
7214 in_commasep_string("keyboard-interactive", methods, methlen);
7217 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
7219 if (s->can_pubkey && !s->done_agent && s->nkeys) {
7222 * Attempt public-key authentication using a key from Pageant.
7225 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7227 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
7229 /* Unpack key from agent response */
7230 s->pklen = GET_32BIT(s->agentp);
7232 s->pkblob = (char *)s->agentp;
7233 s->agentp += s->pklen;
7234 s->alglen = GET_32BIT(s->pkblob);
7235 s->alg = s->pkblob + 4;
7236 s->commentlen = GET_32BIT(s->agentp);
7238 s->commentp = (char *)s->agentp;
7239 s->agentp += s->commentlen;
7240 /* s->agentp now points at next key, if any */
7242 /* See if server will accept it */
7243 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7244 ssh2_pkt_addstring(s->pktout, s->username);
7245 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7246 /* service requested */
7247 ssh2_pkt_addstring(s->pktout, "publickey");
7249 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
7250 ssh2_pkt_addstring_start(s->pktout);
7251 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7252 ssh2_pkt_addstring_start(s->pktout);
7253 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7254 ssh2_pkt_send(ssh, s->pktout);
7255 s->type = AUTH_TYPE_PUBLICKEY_OFFER_QUIET;
7257 crWaitUntilV(pktin);
7258 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7260 /* Offer of key refused. */
7267 if (flags & FLAG_VERBOSE) {
7268 c_write_str(ssh, "Authenticating with "
7270 c_write(ssh, s->commentp, s->commentlen);
7271 c_write_str(ssh, "\" from agent\r\n");
7275 * Server is willing to accept the key.
7276 * Construct a SIGN_REQUEST.
7278 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7279 ssh2_pkt_addstring(s->pktout, s->username);
7280 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7281 /* service requested */
7282 ssh2_pkt_addstring(s->pktout, "publickey");
7284 ssh2_pkt_addbool(s->pktout, TRUE); /* signature included */
7285 ssh2_pkt_addstring_start(s->pktout);
7286 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
7287 ssh2_pkt_addstring_start(s->pktout);
7288 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
7290 /* Ask agent for signature. */
7291 s->siglen = s->pktout->length - 5 + 4 +
7292 ssh->v2_session_id_len;
7293 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7295 s->len = 1; /* message type */
7296 s->len += 4 + s->pklen; /* key blob */
7297 s->len += 4 + s->siglen; /* data to sign */
7298 s->len += 4; /* flags */
7299 s->agentreq = snewn(4 + s->len, char);
7300 PUT_32BIT(s->agentreq, s->len);
7301 s->q = s->agentreq + 4;
7302 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
7303 PUT_32BIT(s->q, s->pklen);
7305 memcpy(s->q, s->pkblob, s->pklen);
7307 PUT_32BIT(s->q, s->siglen);
7309 /* Now the data to be signed... */
7310 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7311 PUT_32BIT(s->q, ssh->v2_session_id_len);
7314 memcpy(s->q, ssh->v2_session_id,
7315 ssh->v2_session_id_len);
7316 s->q += ssh->v2_session_id_len;
7317 memcpy(s->q, s->pktout->data + 5,
7318 s->pktout->length - 5);
7319 s->q += s->pktout->length - 5;
7320 /* And finally the (zero) flags word. */
7322 if (!agent_query(s->agentreq, s->len + 4,
7324 ssh_agent_callback, ssh)) {
7328 bombout(("Unexpected data from server"
7329 " while waiting for agent"
7333 } while (pktin || inlen > 0);
7334 vret = ssh->agent_response;
7335 s->retlen = ssh->agent_response_len;
7340 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
7341 logevent("Sending Pageant's response");
7342 ssh2_add_sigblob(ssh, s->pktout,
7343 s->pkblob, s->pklen,
7345 GET_32BIT(s->ret + 5));
7346 ssh2_pkt_send(ssh, s->pktout);
7347 s->type = AUTH_TYPE_PUBLICKEY;
7349 /* FIXME: less drastic response */
7350 bombout(("Pageant failed to answer challenge"));
7356 /* Do we have any keys left to try? */
7357 if (s->pkblob_in_agent) {
7358 s->done_agent = TRUE;
7359 s->tried_pubkey_config = TRUE;
7362 if (s->keyi >= s->nkeys)
7363 s->done_agent = TRUE;
7366 } else if (s->can_pubkey && s->publickey_blob &&
7367 !s->tried_pubkey_config) {
7369 struct ssh2_userkey *key; /* not live over crReturn */
7370 char *passphrase; /* not live over crReturn */
7372 ssh->pkt_actx = SSH2_PKTCTX_PUBLICKEY;
7374 s->tried_pubkey_config = TRUE;
7377 * Try the public key supplied in the configuration.
7379 * First, offer the public blob to see if the server is
7380 * willing to accept it.
7382 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7383 ssh2_pkt_addstring(s->pktout, s->username);
7384 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7385 /* service requested */
7386 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7387 ssh2_pkt_addbool(s->pktout, FALSE);
7388 /* no signature included */
7389 ssh2_pkt_addstring(s->pktout, s->publickey_algorithm);
7390 ssh2_pkt_addstring_start(s->pktout);
7391 ssh2_pkt_addstring_data(s->pktout,
7392 (char *)s->publickey_blob,
7393 s->publickey_bloblen);
7394 ssh2_pkt_send(ssh, s->pktout);
7395 logevent("Offered public key");
7397 crWaitUntilV(pktin);
7398 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7399 /* Key refused. Give up. */
7400 s->gotit = TRUE; /* reconsider message next loop */
7401 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7402 continue; /* process this new message */
7404 logevent("Offer of public key accepted");
7407 * Actually attempt a serious authentication using
7410 if (flags & FLAG_VERBOSE) {
7411 c_write_str(ssh, "Authenticating with public key \"");
7412 c_write_str(ssh, s->publickey_comment);
7413 c_write_str(ssh, "\"\r\n");
7417 const char *error; /* not live over crReturn */
7418 if (s->publickey_encrypted) {
7420 * Get a passphrase from the user.
7422 int ret; /* need not be kept over crReturn */
7423 s->cur_prompt = new_prompts(ssh->frontend);
7424 s->cur_prompt->to_server = FALSE;
7425 s->cur_prompt->name = dupstr("SSH key passphrase");
7426 add_prompt(s->cur_prompt,
7427 dupprintf("Passphrase for key \"%.100s\": ",
7428 s->publickey_comment),
7429 FALSE, SSH_MAX_PASSWORD_LEN);
7430 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7433 crWaitUntilV(!pktin);
7434 ret = get_userpass_input(s->cur_prompt,
7439 /* Failed to get a passphrase. Terminate. */
7440 free_prompts(s->cur_prompt);
7441 ssh_disconnect(ssh, NULL,
7442 "Unable to authenticate",
7443 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7448 dupstr(s->cur_prompt->prompts[0]->result);
7449 free_prompts(s->cur_prompt);
7451 passphrase = NULL; /* no passphrase needed */
7455 * Try decrypting the key.
7457 key = ssh2_load_userkey(&ssh->cfg.keyfile, passphrase,
7460 /* burn the evidence */
7461 memset(passphrase, 0, strlen(passphrase));
7464 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7466 (key == SSH2_WRONG_PASSPHRASE)) {
7467 c_write_str(ssh, "Wrong passphrase\r\n");
7469 /* and loop again */
7471 c_write_str(ssh, "Unable to load private key (");
7472 c_write_str(ssh, error);
7473 c_write_str(ssh, ")\r\n");
7475 break; /* try something else */
7481 unsigned char *pkblob, *sigblob, *sigdata;
7482 int pkblob_len, sigblob_len, sigdata_len;
7486 * We have loaded the private key and the server
7487 * has announced that it's willing to accept it.
7488 * Hallelujah. Generate a signature and send it.
7490 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7491 ssh2_pkt_addstring(s->pktout, s->username);
7492 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7493 /* service requested */
7494 ssh2_pkt_addstring(s->pktout, "publickey");
7496 ssh2_pkt_addbool(s->pktout, TRUE);
7497 /* signature follows */
7498 ssh2_pkt_addstring(s->pktout, key->alg->name);
7499 pkblob = key->alg->public_blob(key->data,
7501 ssh2_pkt_addstring_start(s->pktout);
7502 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob,
7506 * The data to be signed is:
7510 * followed by everything so far placed in the
7513 sigdata_len = s->pktout->length - 5 + 4 +
7514 ssh->v2_session_id_len;
7515 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7517 sigdata = snewn(sigdata_len, unsigned char);
7519 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7520 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7523 memcpy(sigdata+p, ssh->v2_session_id,
7524 ssh->v2_session_id_len);
7525 p += ssh->v2_session_id_len;
7526 memcpy(sigdata+p, s->pktout->data + 5,
7527 s->pktout->length - 5);
7528 p += s->pktout->length - 5;
7529 assert(p == sigdata_len);
7530 sigblob = key->alg->sign(key->data, (char *)sigdata,
7531 sigdata_len, &sigblob_len);
7532 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7533 sigblob, sigblob_len);
7538 ssh2_pkt_send(ssh, s->pktout);
7539 s->type = AUTH_TYPE_PUBLICKEY;
7540 key->alg->freekey(key->data);
7543 } else if (s->can_keyb_inter && !s->kbd_inter_refused) {
7546 * Keyboard-interactive authentication.
7549 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7551 ssh->pkt_actx = SSH2_PKTCTX_KBDINTER;
7553 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7554 ssh2_pkt_addstring(s->pktout, s->username);
7555 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7556 /* service requested */
7557 ssh2_pkt_addstring(s->pktout, "keyboard-interactive");
7559 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7560 ssh2_pkt_addstring(s->pktout, ""); /* submethods */
7561 ssh2_pkt_send(ssh, s->pktout);
7563 crWaitUntilV(pktin);
7564 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7565 /* Server is not willing to do keyboard-interactive
7566 * at all (or, bizarrely but legally, accepts the
7567 * user without actually issuing any prompts).
7568 * Give up on it entirely. */
7570 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7571 logevent("Keyboard-interactive authentication refused");
7572 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7573 s->kbd_inter_refused = TRUE; /* don't try it again */
7578 * Loop while the server continues to send INFO_REQUESTs.
7580 while (pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
7582 char *name, *inst, *lang;
7583 int name_len, inst_len, lang_len;
7587 * We've got a fresh USERAUTH_INFO_REQUEST.
7588 * Get the preamble and start building a prompt.
7590 ssh_pkt_getstring(pktin, &name, &name_len);
7591 ssh_pkt_getstring(pktin, &inst, &inst_len);
7592 ssh_pkt_getstring(pktin, &lang, &lang_len);
7593 s->cur_prompt = new_prompts(ssh->frontend);
7594 s->cur_prompt->to_server = TRUE;
7596 /* FIXME: better prefix to distinguish from
7598 s->cur_prompt->name =
7599 dupprintf("SSH server: %.*s", name_len, name);
7600 s->cur_prompt->name_reqd = TRUE;
7602 s->cur_prompt->name =
7603 dupstr("SSH server authentication");
7604 s->cur_prompt->name_reqd = FALSE;
7606 /* FIXME: ugly to print "Using..." in prompt _every_
7607 * time round. Can this be done more subtly? */
7608 s->cur_prompt->instruction =
7609 dupprintf("Using keyboard-interactive authentication.%s%.*s",
7610 inst_len ? "\n" : "", inst_len, inst);
7611 s->cur_prompt->instr_reqd = TRUE;
7614 * Get the prompts from the packet.
7616 s->num_prompts = ssh_pkt_getuint32(pktin);
7617 for (i = 0; i < s->num_prompts; i++) {
7621 static char noprompt[] =
7622 "<server failed to send prompt>: ";
7624 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7625 echo = ssh2_pkt_getbool(pktin);
7628 prompt_len = lenof(noprompt)-1;
7630 add_prompt(s->cur_prompt,
7631 dupprintf("%.*s", prompt_len, prompt),
7632 echo, SSH_MAX_PASSWORD_LEN);
7636 * Get the user's responses.
7638 if (s->num_prompts) {
7639 int ret; /* not live over crReturn */
7640 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7643 crWaitUntilV(!pktin);
7644 ret = get_userpass_input(s->cur_prompt, in, inlen);
7649 * Failed to get responses. Terminate.
7651 free_prompts(s->cur_prompt);
7652 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7653 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7660 * Send the responses to the server.
7662 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7663 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7664 for (i=0; i < s->num_prompts; i++) {
7665 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7666 ssh2_pkt_addstring(s->pktout,
7667 s->cur_prompt->prompts[i]->result);
7668 end_log_omission(ssh, s->pktout);
7670 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7673 * Get the next packet in case it's another
7676 crWaitUntilV(pktin);
7681 * We should have SUCCESS or FAILURE now.
7685 } else if (s->can_passwd) {
7688 * Plain old password authentication.
7690 int ret; /* not live over crReturn */
7691 int changereq_first_time; /* not live over crReturn */
7693 ssh->pkt_actx = SSH2_PKTCTX_PASSWORD;
7695 s->cur_prompt = new_prompts(ssh->frontend);
7696 s->cur_prompt->to_server = TRUE;
7697 s->cur_prompt->name = dupstr("SSH password");
7698 add_prompt(s->cur_prompt, dupprintf("%.90s@%.90s's password: ",
7701 FALSE, SSH_MAX_PASSWORD_LEN);
7703 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7706 crWaitUntilV(!pktin);
7707 ret = get_userpass_input(s->cur_prompt, in, inlen);
7712 * Failed to get responses. Terminate.
7714 free_prompts(s->cur_prompt);
7715 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7716 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7721 * Squirrel away the password. (We may need it later if
7722 * asked to change it.)
7724 s->password = dupstr(s->cur_prompt->prompts[0]->result);
7725 free_prompts(s->cur_prompt);
7728 * Send the password packet.
7730 * We pad out the password packet to 256 bytes to make
7731 * it harder for an attacker to find the length of the
7734 * Anyone using a password longer than 256 bytes
7735 * probably doesn't have much to worry about from
7736 * people who find out how long their password is!
7738 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7739 ssh2_pkt_addstring(s->pktout, s->username);
7740 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7741 /* service requested */
7742 ssh2_pkt_addstring(s->pktout, "password");
7743 ssh2_pkt_addbool(s->pktout, FALSE);
7744 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7745 ssh2_pkt_addstring(s->pktout, s->password);
7746 end_log_omission(ssh, s->pktout);
7747 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7748 logevent("Sent password");
7749 s->type = AUTH_TYPE_PASSWORD;
7752 * Wait for next packet, in case it's a password change
7755 crWaitUntilV(pktin);
7756 changereq_first_time = TRUE;
7758 while (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
7761 * We're being asked for a new password
7762 * (perhaps not for the first time).
7763 * Loop until the server accepts it.
7766 int got_new = FALSE; /* not live over crReturn */
7767 char *prompt; /* not live over crReturn */
7768 int prompt_len; /* not live over crReturn */
7772 if (changereq_first_time)
7773 msg = "Server requested password change";
7775 msg = "Server rejected new password";
7777 c_write_str(ssh, msg);
7778 c_write_str(ssh, "\r\n");
7781 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7783 s->cur_prompt = new_prompts(ssh->frontend);
7784 s->cur_prompt->to_server = TRUE;
7785 s->cur_prompt->name = dupstr("New SSH password");
7786 s->cur_prompt->instruction =
7787 dupprintf("%.*s", prompt_len, prompt);
7788 s->cur_prompt->instr_reqd = TRUE;
7790 * There's no explicit requirement in the protocol
7791 * for the "old" passwords in the original and
7792 * password-change messages to be the same, and
7793 * apparently some Cisco kit supports password change
7794 * by the user entering a blank password originally
7795 * and the real password subsequently, so,
7796 * reluctantly, we prompt for the old password again.
7798 * (On the other hand, some servers don't even bother
7799 * to check this field.)
7801 add_prompt(s->cur_prompt,
7802 dupstr("Current password (blank for previously entered password): "),
7803 FALSE, SSH_MAX_PASSWORD_LEN);
7804 add_prompt(s->cur_prompt, dupstr("Enter new password: "),
7805 FALSE, SSH_MAX_PASSWORD_LEN);
7806 add_prompt(s->cur_prompt, dupstr("Confirm new password: "),
7807 FALSE, SSH_MAX_PASSWORD_LEN);
7810 * Loop until the user manages to enter the same
7815 ret = get_userpass_input(s->cur_prompt, NULL, 0);
7818 crWaitUntilV(!pktin);
7819 ret = get_userpass_input(s->cur_prompt, in, inlen);
7824 * Failed to get responses. Terminate.
7826 /* burn the evidence */
7827 free_prompts(s->cur_prompt);
7828 memset(s->password, 0, strlen(s->password));
7830 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7831 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7837 * If the user specified a new original password
7838 * (IYSWIM), overwrite any previously specified
7840 * (A side effect is that the user doesn't have to
7841 * re-enter it if they louse up the new password.)
7843 if (s->cur_prompt->prompts[0]->result[0]) {
7844 memset(s->password, 0, strlen(s->password));
7845 /* burn the evidence */
7848 dupstr(s->cur_prompt->prompts[0]->result);
7852 * Check the two new passwords match.
7854 got_new = (strcmp(s->cur_prompt->prompts[1]->result,
7855 s->cur_prompt->prompts[2]->result)
7858 /* They don't. Silly user. */
7859 c_write_str(ssh, "Passwords do not match\r\n");
7864 * Send the new password (along with the old one).
7865 * (see above for padding rationale)
7867 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7868 ssh2_pkt_addstring(s->pktout, s->username);
7869 ssh2_pkt_addstring(s->pktout, "ssh-connection");
7870 /* service requested */
7871 ssh2_pkt_addstring(s->pktout, "password");
7872 ssh2_pkt_addbool(s->pktout, TRUE);
7873 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7874 ssh2_pkt_addstring(s->pktout, s->password);
7875 ssh2_pkt_addstring(s->pktout,
7876 s->cur_prompt->prompts[1]->result);
7877 free_prompts(s->cur_prompt);
7878 end_log_omission(ssh, s->pktout);
7879 ssh2_pkt_send_with_padding(ssh, s->pktout, 256);
7880 logevent("Sent new password");
7883 * Now see what the server has to say about it.
7884 * (If it's CHANGEREQ again, it's not happy with the
7887 crWaitUntilV(pktin);
7888 changereq_first_time = FALSE;
7893 * We need to reexamine the current pktin at the top
7894 * of the loop. Either:
7895 * - we weren't asked to change password at all, in
7896 * which case it's a SUCCESS or FAILURE with the
7898 * - we sent a new password, and the server was
7899 * either OK with it (SUCCESS or FAILURE w/partial
7900 * success) or unhappy with the _old_ password
7901 * (FAILURE w/o partial success)
7902 * In any of these cases, we go back to the top of
7903 * the loop and start again.
7908 * We don't need the old password any more, in any
7909 * case. Burn the evidence.
7911 memset(s->password, 0, strlen(s->password));
7916 ssh_disconnect(ssh, NULL,
7917 "No supported authentication methods available",
7918 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7926 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7928 /* Clear up various bits and pieces from authentication. */
7929 if (s->publickey_blob) {
7930 sfree(s->publickey_blob);
7931 sfree(s->publickey_comment);
7933 if (s->agent_response)
7934 sfree(s->agent_response);
7937 * Now the connection protocol has started, one way or another.
7940 ssh->channels = newtree234(ssh_channelcmp);
7943 * Set up handlers for some connection protocol messages, so we
7944 * don't have to handle them repeatedly in this coroutine.
7946 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7947 ssh2_msg_channel_window_adjust;
7948 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7949 ssh2_msg_global_request;
7952 * Create the main session channel.
7954 if (ssh->cfg.ssh_no_shell) {
7955 ssh->mainchan = NULL;
7956 } else if (*ssh->cfg.ssh_nc_host) {
7958 * Just start a direct-tcpip channel and use it as the main
7961 ssh->mainchan = snew(struct ssh_channel);
7962 ssh->mainchan->ssh = ssh;
7963 ssh->mainchan->localid = alloc_channel_id(ssh);
7965 "Opening direct-tcpip channel to %s:%d in place of session",
7966 ssh->cfg.ssh_nc_host, ssh->cfg.ssh_nc_port);
7967 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7968 ssh2_pkt_addstring(s->pktout, "direct-tcpip");
7969 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7970 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7971 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7972 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7973 ssh2_pkt_addstring(s->pktout, ssh->cfg.ssh_nc_host);
7974 ssh2_pkt_adduint32(s->pktout, ssh->cfg.ssh_nc_port);
7976 * There's nothing meaningful to put in the originator
7977 * fields, but some servers insist on syntactically correct
7980 ssh2_pkt_addstring(s->pktout, "0.0.0.0");
7981 ssh2_pkt_adduint32(s->pktout, 0);
7982 ssh2_pkt_send(ssh, s->pktout);
7984 crWaitUntilV(pktin);
7985 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7986 bombout(("Server refused to open a direct-tcpip channel"));
7988 /* FIXME: error data comes back in FAILURE packet */
7990 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7991 bombout(("Server's channel confirmation cited wrong channel"));
7994 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7995 ssh->mainchan->halfopen = FALSE;
7996 ssh->mainchan->type = CHAN_MAINSESSION;
7997 ssh->mainchan->closes = 0;
7998 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7999 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8000 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
8001 add234(ssh->channels, ssh->mainchan);
8002 update_specials_menu(ssh->frontend);
8003 logevent("Opened direct-tcpip channel");
8006 ssh->mainchan = snew(struct ssh_channel);
8007 ssh->mainchan->ssh = ssh;
8008 ssh->mainchan->localid = alloc_channel_id(ssh);
8009 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8010 ssh2_pkt_addstring(s->pktout, "session");
8011 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
8012 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
8013 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
8014 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
8015 ssh2_pkt_send(ssh, s->pktout);
8016 crWaitUntilV(pktin);
8017 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8018 bombout(("Server refused to open a session"));
8020 /* FIXME: error data comes back in FAILURE packet */
8022 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
8023 bombout(("Server's channel confirmation cited wrong channel"));
8026 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
8027 ssh->mainchan->halfopen = FALSE;
8028 ssh->mainchan->type = CHAN_MAINSESSION;
8029 ssh->mainchan->closes = 0;
8030 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
8031 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
8032 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
8033 add234(ssh->channels, ssh->mainchan);
8034 update_specials_menu(ssh->frontend);
8035 logevent("Opened channel for session");
8036 ssh->ncmode = FALSE;
8040 * Now we have a channel, make dispatch table entries for
8041 * general channel-based messages.
8043 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
8044 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
8045 ssh2_msg_channel_data;
8046 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
8047 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
8048 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
8049 ssh2_msg_channel_open_confirmation;
8050 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
8051 ssh2_msg_channel_open_failure;
8052 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
8053 ssh2_msg_channel_request;
8054 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
8055 ssh2_msg_channel_open;
8058 * Potentially enable X11 forwarding.
8060 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.x11_forward) {
8061 char proto[20], data[64];
8062 logevent("Requesting X11 forwarding");
8063 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
8064 data, sizeof(data), ssh->cfg.x11_auth);
8065 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
8066 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8067 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8068 ssh2_pkt_addstring(s->pktout, "x11-req");
8069 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8070 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
8071 ssh2_pkt_addstring(s->pktout, proto);
8073 * Note that while we blank the X authentication data here, we don't
8074 * take any special action to blank the start of an X11 channel,
8075 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
8076 * without having session blanking enabled is likely to leak your
8077 * cookie into the log.
8079 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
8080 ssh2_pkt_addstring(s->pktout, data);
8081 end_log_omission(ssh, s->pktout);
8082 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
8083 ssh2_pkt_send(ssh, s->pktout);
8085 crWaitUntilV(pktin);
8087 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8088 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8089 bombout(("Unexpected response to X11 forwarding request:"
8090 " packet type %d", pktin->type));
8093 logevent("X11 forwarding refused");
8095 logevent("X11 forwarding enabled");
8096 ssh->X11_fwd_enabled = TRUE;
8101 * Enable port forwardings.
8103 ssh_setup_portfwd(ssh, &ssh->cfg);
8106 * Potentially enable agent forwarding.
8108 if (ssh->mainchan && !ssh->ncmode && ssh->cfg.agentfwd && agent_exists()) {
8109 logevent("Requesting OpenSSH-style agent forwarding");
8110 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8111 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8112 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
8113 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8114 ssh2_pkt_send(ssh, s->pktout);
8116 crWaitUntilV(pktin);
8118 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8119 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8120 bombout(("Unexpected response to agent forwarding request:"
8121 " packet type %d", pktin->type));
8124 logevent("Agent forwarding refused");
8126 logevent("Agent forwarding enabled");
8127 ssh->agentfwd_enabled = TRUE;
8132 * Now allocate a pty for the session.
8134 if (ssh->mainchan && !ssh->ncmode && !ssh->cfg.nopty) {
8135 /* Unpick the terminal-speed string. */
8136 /* XXX perhaps we should allow no speeds to be sent. */
8137 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
8138 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
8139 /* Build the pty request. */
8140 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8141 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8142 ssh2_pkt_addstring(s->pktout, "pty-req");
8143 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8144 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
8145 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
8146 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
8147 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
8148 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
8149 ssh2_pkt_addstring_start(s->pktout);
8150 parse_ttymodes(ssh, ssh->cfg.ttymodes,
8151 ssh2_send_ttymode, (void *)s->pktout);
8152 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
8153 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
8154 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
8155 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
8156 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
8157 ssh2_pkt_send(ssh, s->pktout);
8158 ssh->state = SSH_STATE_INTERMED;
8160 crWaitUntilV(pktin);
8162 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8163 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8164 bombout(("Unexpected response to pty request:"
8165 " packet type %d", pktin->type));
8168 c_write_str(ssh, "Server refused to allocate pty\r\n");
8169 ssh->editing = ssh->echoing = 1;
8171 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
8172 ssh->ospeed, ssh->ispeed);
8175 ssh->editing = ssh->echoing = 1;
8179 * Send environment variables.
8181 * Simplest thing here is to send all the requests at once, and
8182 * then wait for a whole bunch of successes or failures.
8184 if (ssh->mainchan && !ssh->ncmode && *ssh->cfg.environmt) {
8185 char *e = ssh->cfg.environmt;
8186 char *var, *varend, *val;
8192 while (*e && *e != '\t') e++;
8194 if (*e == '\t') e++;
8199 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8200 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
8201 ssh2_pkt_addstring(s->pktout, "env");
8202 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8203 ssh2_pkt_addstring_start(s->pktout);
8204 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
8205 ssh2_pkt_addstring(s->pktout, val);
8206 ssh2_pkt_send(ssh, s->pktout);
8211 logeventf(ssh, "Sent %d environment variables", s->num_env);
8214 s->env_left = s->num_env;
8216 while (s->env_left > 0) {
8217 crWaitUntilV(pktin);
8219 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8220 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8221 bombout(("Unexpected response to environment request:"
8222 " packet type %d", pktin->type));
8232 if (s->env_ok == s->num_env) {
8233 logevent("All environment variables successfully set");
8234 } else if (s->env_ok == 0) {
8235 logevent("All environment variables refused");
8236 c_write_str(ssh, "Server refused to set environment variables\r\n");
8238 logeventf(ssh, "%d environment variables refused",
8239 s->num_env - s->env_ok);
8240 c_write_str(ssh, "Server refused to set all environment variables\r\n");
8245 * Start a shell or a remote command. We may have to attempt
8246 * this twice if the config data has provided a second choice
8249 if (ssh->mainchan && !ssh->ncmode) while (1) {
8253 if (ssh->fallback_cmd) {
8254 subsys = ssh->cfg.ssh_subsys2;
8255 cmd = ssh->cfg.remote_cmd_ptr2;
8257 subsys = ssh->cfg.ssh_subsys;
8258 cmd = ssh->cfg.remote_cmd_ptr;
8259 if (!cmd) cmd = ssh->cfg.remote_cmd;
8262 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8263 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
8265 ssh2_pkt_addstring(s->pktout, "subsystem");
8266 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8267 ssh2_pkt_addstring(s->pktout, cmd);
8269 ssh2_pkt_addstring(s->pktout, "exec");
8270 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8271 ssh2_pkt_addstring(s->pktout, cmd);
8273 ssh2_pkt_addstring(s->pktout, "shell");
8274 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
8276 ssh2_pkt_send(ssh, s->pktout);
8278 crWaitUntilV(pktin);
8280 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
8281 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
8282 bombout(("Unexpected response to shell/command request:"
8283 " packet type %d", pktin->type));
8287 * We failed to start the command. If this is the
8288 * fallback command, we really are finished; if it's
8289 * not, and if the fallback command exists, try falling
8290 * back to it before complaining.
8292 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
8293 logevent("Primary command failed; attempting fallback");
8294 ssh->fallback_cmd = TRUE;
8297 bombout(("Server refused to start a shell/command"));
8300 logevent("Started a shell/command");
8305 ssh->state = SSH_STATE_SESSION;
8306 if (ssh->size_needed)
8307 ssh_size(ssh, ssh->term_width, ssh->term_height);
8308 if (ssh->eof_needed)
8309 ssh_special(ssh, TS_EOF);
8315 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
8320 s->try_send = FALSE;
8324 * _All_ the connection-layer packets we expect to
8325 * receive are now handled by the dispatch table.
8326 * Anything that reaches here must be bogus.
8329 bombout(("Strange packet received: type %d", pktin->type));
8331 } else if (ssh->mainchan) {
8333 * We have spare data. Add it to the channel buffer.
8335 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
8340 struct ssh_channel *c;
8342 * Try to send data on all channels if we can.
8344 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
8345 ssh2_try_send_and_unthrottle(c);
8353 * Handlers for SSH-2 messages that might arrive at any moment.
8355 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
8357 /* log reason code in disconnect message */
8359 int nowlen, reason, msglen;
8361 reason = ssh_pkt_getuint32(pktin);
8362 ssh_pkt_getstring(pktin, &msg, &msglen);
8364 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
8365 buf = dupprintf("Received disconnect message (%s)",
8366 ssh2_disconnect_reasons[reason]);
8368 buf = dupprintf("Received disconnect message (unknown"
8369 " type %d)", reason);
8373 buf = dupprintf("Disconnection message text: %n%.*s",
8374 &nowlen, msglen, msg);
8376 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
8378 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
8379 ssh2_disconnect_reasons[reason] : "unknown",
8384 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
8386 /* log the debug message */
8391 /* XXX maybe we should actually take notice of this */
8392 always_display = ssh2_pkt_getbool(pktin);
8393 ssh_pkt_getstring(pktin, &msg, &msglen);
8395 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
8398 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
8400 struct Packet *pktout;
8401 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
8402 ssh2_pkt_adduint32(pktout, pktin->sequence);
8404 * UNIMPLEMENTED messages MUST appear in the same order as the
8405 * messages they respond to. Hence, never queue them.
8407 ssh2_pkt_send_noqueue(ssh, pktout);
8411 * Handle the top-level SSH-2 protocol.
8413 static void ssh2_protocol_setup(Ssh ssh)
8418 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
8420 for (i = 0; i < 256; i++)
8421 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
8424 * Any message we actually understand, we set to NULL so that
8425 * the coroutines will get it.
8427 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
8428 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
8429 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
8430 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
8431 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
8432 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
8433 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
8434 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
8435 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
8436 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
8437 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
8438 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
8439 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
8440 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
8441 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
8442 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
8443 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
8444 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
8445 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
8446 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
8447 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
8448 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
8449 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
8450 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
8451 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
8452 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
8453 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
8454 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
8455 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
8456 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
8457 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
8458 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
8459 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
8462 * These special message types we install handlers for.
8464 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
8465 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
8466 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
8469 static void ssh2_timer(void *ctx, long now)
8473 if (ssh->state == SSH_STATE_CLOSED)
8476 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
8477 now - ssh->next_rekey >= 0) {
8478 do_ssh2_transport(ssh, "timeout", -1, NULL);
8482 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
8483 struct Packet *pktin)
8485 unsigned char *in = (unsigned char *)vin;
8486 if (ssh->state == SSH_STATE_CLOSED)
8490 ssh->incoming_data_size += pktin->encrypted_len;
8491 if (!ssh->kex_in_progress &&
8492 ssh->max_data_size != 0 &&
8493 ssh->incoming_data_size > ssh->max_data_size)
8494 do_ssh2_transport(ssh, "too much data received", -1, NULL);
8497 if (pktin && ssh->packet_dispatch[pktin->type]) {
8498 ssh->packet_dispatch[pktin->type](ssh, pktin);
8502 if (!ssh->protocol_initial_phase_done ||
8503 (pktin && pktin->type >= 20 && pktin->type < 50)) {
8504 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
8505 !ssh->protocol_initial_phase_done) {
8506 ssh->protocol_initial_phase_done = TRUE;
8508 * Allow authconn to initialise itself.
8510 do_ssh2_authconn(ssh, NULL, 0, NULL);
8513 do_ssh2_authconn(ssh, in, inlen, pktin);
8518 * Called to set up the connection.
8520 * Returns an error message, or NULL on success.
8522 static const char *ssh_init(void *frontend_handle, void **backend_handle,
8524 char *host, int port, char **realhost, int nodelay,
8530 ssh = snew(struct ssh_tag);
8531 ssh->cfg = *cfg; /* STRUCTURE COPY */
8532 ssh->version = 0; /* when not ready yet */
8535 ssh->v1_cipher_ctx = NULL;
8536 ssh->crcda_ctx = NULL;
8537 ssh->cscipher = NULL;
8538 ssh->cs_cipher_ctx = NULL;
8539 ssh->sccipher = NULL;
8540 ssh->sc_cipher_ctx = NULL;
8542 ssh->cs_mac_ctx = NULL;
8544 ssh->sc_mac_ctx = NULL;
8546 ssh->cs_comp_ctx = NULL;
8548 ssh->sc_comp_ctx = NULL;
8550 ssh->kex_ctx = NULL;
8551 ssh->hostkey = NULL;
8553 ssh->close_expected = FALSE;
8554 ssh->clean_exit = FALSE;
8555 ssh->state = SSH_STATE_PREPACKET;
8556 ssh->size_needed = FALSE;
8557 ssh->eof_needed = FALSE;
8560 ssh->deferred_send_data = NULL;
8561 ssh->deferred_len = 0;
8562 ssh->deferred_size = 0;
8563 ssh->fallback_cmd = 0;
8564 ssh->pkt_kctx = SSH2_PKTCTX_NOKEX;
8565 ssh->pkt_actx = SSH2_PKTCTX_NOAUTH;
8566 ssh->x11auth = NULL;
8567 ssh->v1_compressing = FALSE;
8568 ssh->v2_outgoing_sequence = 0;
8569 ssh->ssh1_rdpkt_crstate = 0;
8570 ssh->ssh2_rdpkt_crstate = 0;
8571 ssh->do_ssh_init_crstate = 0;
8572 ssh->ssh_gotdata_crstate = 0;
8573 ssh->do_ssh1_connection_crstate = 0;
8574 ssh->do_ssh1_login_crstate = 0;
8575 ssh->do_ssh2_transport_crstate = 0;
8576 ssh->do_ssh2_authconn_crstate = 0;
8577 ssh->do_ssh_init_state = NULL;
8578 ssh->do_ssh1_login_state = NULL;
8579 ssh->do_ssh2_transport_state = NULL;
8580 ssh->do_ssh2_authconn_state = NULL;
8583 ssh->mainchan = NULL;
8584 ssh->throttled_all = 0;
8585 ssh->v1_stdout_throttling = 0;
8587 ssh->queuelen = ssh->queuesize = 0;
8588 ssh->queueing = FALSE;
8589 ssh->qhead = ssh->qtail = NULL;
8590 ssh->deferred_rekey_reason = NULL;
8591 bufchain_init(&ssh->queued_incoming_data);
8592 ssh->frozen = FALSE;
8594 *backend_handle = ssh;
8597 if (crypto_startup() == 0)
8598 return "Microsoft high encryption pack not installed!";
8601 ssh->frontend = frontend_handle;
8602 ssh->term_width = ssh->cfg.width;
8603 ssh->term_height = ssh->cfg.height;
8605 ssh->channels = NULL;
8606 ssh->rportfwds = NULL;
8607 ssh->portfwds = NULL;
8612 ssh->v1_throttle_count = 0;
8613 ssh->overall_bufsize = 0;
8614 ssh->fallback_cmd = 0;
8616 ssh->protocol = NULL;
8618 ssh->protocol_initial_phase_done = FALSE;
8622 ssh->incoming_data_size = ssh->outgoing_data_size =
8623 ssh->deferred_data_size = 0L;
8624 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
8625 ssh->kex_in_progress = FALSE;
8627 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
8636 static void ssh_free(void *handle)
8638 Ssh ssh = (Ssh) handle;
8639 struct ssh_channel *c;
8640 struct ssh_rportfwd *pf;
8642 if (ssh->v1_cipher_ctx)
8643 ssh->cipher->free_context(ssh->v1_cipher_ctx);
8644 if (ssh->cs_cipher_ctx)
8645 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
8646 if (ssh->sc_cipher_ctx)
8647 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
8648 if (ssh->cs_mac_ctx)
8649 ssh->csmac->free_context(ssh->cs_mac_ctx);
8650 if (ssh->sc_mac_ctx)
8651 ssh->scmac->free_context(ssh->sc_mac_ctx);
8652 if (ssh->cs_comp_ctx) {
8654 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
8656 zlib_compress_cleanup(ssh->cs_comp_ctx);
8658 if (ssh->sc_comp_ctx) {
8660 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
8662 zlib_decompress_cleanup(ssh->sc_comp_ctx);
8665 dh_cleanup(ssh->kex_ctx);
8666 sfree(ssh->savedhost);
8668 while (ssh->queuelen-- > 0)
8669 ssh_free_packet(ssh->queue[ssh->queuelen]);
8672 while (ssh->qhead) {
8673 struct queued_handler *qh = ssh->qhead;
8674 ssh->qhead = qh->next;
8677 ssh->qhead = ssh->qtail = NULL;
8679 if (ssh->channels) {
8680 while ((c = delpos234(ssh->channels, 0)) != NULL) {
8683 if (c->u.x11.s != NULL)
8684 x11_close(c->u.x11.s);
8687 if (c->u.pfd.s != NULL)
8688 pfd_close(c->u.pfd.s);
8693 freetree234(ssh->channels);
8694 ssh->channels = NULL;
8697 if (ssh->rportfwds) {
8698 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8700 freetree234(ssh->rportfwds);
8701 ssh->rportfwds = NULL;
8703 sfree(ssh->deferred_send_data);
8705 x11_free_auth(ssh->x11auth);
8706 sfree(ssh->do_ssh_init_state);
8707 sfree(ssh->do_ssh1_login_state);
8708 sfree(ssh->do_ssh2_transport_state);
8709 sfree(ssh->do_ssh2_authconn_state);
8712 if (ssh->crcda_ctx) {
8713 crcda_free_context(ssh->crcda_ctx);
8714 ssh->crcda_ctx = NULL;
8717 ssh_do_close(ssh, TRUE);
8718 expire_timer_context(ssh);
8720 pinger_free(ssh->pinger);
8721 bufchain_clear(&ssh->queued_incoming_data);
8728 * Reconfigure the SSH backend.
8730 static void ssh_reconfig(void *handle, Config *cfg)
8732 Ssh ssh = (Ssh) handle;
8733 char *rekeying = NULL, rekey_mandatory = FALSE;
8734 unsigned long old_max_data_size;
8736 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8738 ssh_setup_portfwd(ssh, cfg);
8740 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8741 cfg->ssh_rekey_time != 0) {
8742 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8743 long now = GETTICKCOUNT();
8745 if (new_next - now < 0) {
8746 rekeying = "timeout shortened";
8748 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8752 old_max_data_size = ssh->max_data_size;
8753 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8754 if (old_max_data_size != ssh->max_data_size &&
8755 ssh->max_data_size != 0) {
8756 if (ssh->outgoing_data_size > ssh->max_data_size ||
8757 ssh->incoming_data_size > ssh->max_data_size)
8758 rekeying = "data limit lowered";
8761 if (ssh->cfg.compression != cfg->compression) {
8762 rekeying = "compression setting changed";
8763 rekey_mandatory = TRUE;
8766 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8767 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8768 sizeof(ssh->cfg.ssh_cipherlist))) {
8769 rekeying = "cipher settings changed";
8770 rekey_mandatory = TRUE;
8773 ssh->cfg = *cfg; /* STRUCTURE COPY */
8776 if (!ssh->kex_in_progress) {
8777 do_ssh2_transport(ssh, rekeying, -1, NULL);
8778 } else if (rekey_mandatory) {
8779 ssh->deferred_rekey_reason = rekeying;
8785 * Called to send data down the SSH connection.
8787 static int ssh_send(void *handle, char *buf, int len)
8789 Ssh ssh = (Ssh) handle;
8791 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8794 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8796 return ssh_sendbuffer(ssh);
8800 * Called to query the current amount of buffered stdin data.
8802 static int ssh_sendbuffer(void *handle)
8804 Ssh ssh = (Ssh) handle;
8807 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8811 * If the SSH socket itself has backed up, add the total backup
8812 * size on that to any individual buffer on the stdin channel.
8815 if (ssh->throttled_all)
8816 override_value = ssh->overall_bufsize;
8818 if (ssh->version == 1) {
8819 return override_value;
8820 } else if (ssh->version == 2) {
8821 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8822 return override_value;
8824 return (override_value +
8825 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8832 * Called to set the size of the window from SSH's POV.
8834 static void ssh_size(void *handle, int width, int height)
8836 Ssh ssh = (Ssh) handle;
8837 struct Packet *pktout;
8839 ssh->term_width = width;
8840 ssh->term_height = height;
8842 switch (ssh->state) {
8843 case SSH_STATE_BEFORE_SIZE:
8844 case SSH_STATE_PREPACKET:
8845 case SSH_STATE_CLOSED:
8846 break; /* do nothing */
8847 case SSH_STATE_INTERMED:
8848 ssh->size_needed = TRUE; /* buffer for later */
8850 case SSH_STATE_SESSION:
8851 if (!ssh->cfg.nopty) {
8852 if (ssh->version == 1) {
8853 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8854 PKT_INT, ssh->term_height,
8855 PKT_INT, ssh->term_width,
8856 PKT_INT, 0, PKT_INT, 0, PKT_END);
8857 } else if (ssh->mainchan) {
8858 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8859 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8860 ssh2_pkt_addstring(pktout, "window-change");
8861 ssh2_pkt_addbool(pktout, 0);
8862 ssh2_pkt_adduint32(pktout, ssh->term_width);
8863 ssh2_pkt_adduint32(pktout, ssh->term_height);
8864 ssh2_pkt_adduint32(pktout, 0);
8865 ssh2_pkt_adduint32(pktout, 0);
8866 ssh2_pkt_send(ssh, pktout);
8874 * Return a list of the special codes that make sense in this
8877 static const struct telnet_special *ssh_get_specials(void *handle)
8879 static const struct telnet_special ssh1_ignore_special[] = {
8880 {"IGNORE message", TS_NOP}
8882 static const struct telnet_special ssh2_transport_specials[] = {
8883 {"IGNORE message", TS_NOP},
8884 {"Repeat key exchange", TS_REKEY},
8886 static const struct telnet_special ssh2_session_specials[] = {
8889 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8890 * They include all the ISO C signals, but are a subset of the POSIX
8891 * required signals. */
8892 {"SIGINT (Interrupt)", TS_SIGINT},
8893 {"SIGTERM (Terminate)", TS_SIGTERM},
8894 {"SIGKILL (Kill)", TS_SIGKILL},
8895 {"SIGQUIT (Quit)", TS_SIGQUIT},
8896 {"SIGHUP (Hangup)", TS_SIGHUP},
8897 {"More signals", TS_SUBMENU},
8898 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8899 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8900 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8901 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8904 static const struct telnet_special specials_end[] = {
8907 /* XXX review this length for any changes: */
8908 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8909 lenof(ssh2_session_specials) +
8910 lenof(specials_end)];
8911 Ssh ssh = (Ssh) handle;
8913 #define ADD_SPECIALS(name) \
8915 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8916 memcpy(&ssh_specials[i], name, sizeof name); \
8920 if (ssh->version == 1) {
8921 /* Don't bother offering IGNORE if we've decided the remote
8922 * won't cope with it, since we wouldn't bother sending it if
8924 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8925 ADD_SPECIALS(ssh1_ignore_special);
8926 } else if (ssh->version == 2) {
8927 ADD_SPECIALS(ssh2_transport_specials);
8929 ADD_SPECIALS(ssh2_session_specials);
8930 } /* else we're not ready yet */
8933 ADD_SPECIALS(specials_end);
8934 return ssh_specials;
8942 * Send special codes. TS_EOF is useful for `plink', so you
8943 * can send an EOF and collect resulting output (e.g. `plink
8946 static void ssh_special(void *handle, Telnet_Special code)
8948 Ssh ssh = (Ssh) handle;
8949 struct Packet *pktout;
8951 if (code == TS_EOF) {
8952 if (ssh->state != SSH_STATE_SESSION) {
8954 * Buffer the EOF in case we are pre-SESSION, so we can
8955 * send it as soon as we reach SESSION.
8958 ssh->eof_needed = TRUE;
8961 if (ssh->version == 1) {
8962 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8963 } else if (ssh->mainchan) {
8964 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8965 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8966 ssh2_pkt_send(ssh, pktout);
8967 ssh->send_ok = 0; /* now stop trying to read from stdin */
8969 logevent("Sent EOF message");
8970 } else if (code == TS_PING || code == TS_NOP) {
8971 if (ssh->state == SSH_STATE_CLOSED
8972 || ssh->state == SSH_STATE_PREPACKET) return;
8973 if (ssh->version == 1) {
8974 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8975 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8977 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8978 ssh2_pkt_addstring_start(pktout);
8979 ssh2_pkt_send_noqueue(ssh, pktout);
8981 } else if (code == TS_REKEY) {
8982 if (!ssh->kex_in_progress && ssh->version == 2) {
8983 do_ssh2_transport(ssh, "at user request", -1, NULL);
8985 } else if (code == TS_BRK) {
8986 if (ssh->state == SSH_STATE_CLOSED
8987 || ssh->state == SSH_STATE_PREPACKET) return;
8988 if (ssh->version == 1) {
8989 logevent("Unable to send BREAK signal in SSH-1");
8990 } else if (ssh->mainchan) {
8991 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8992 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8993 ssh2_pkt_addstring(pktout, "break");
8994 ssh2_pkt_addbool(pktout, 0);
8995 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8996 ssh2_pkt_send(ssh, pktout);
8999 /* Is is a POSIX signal? */
9000 char *signame = NULL;
9001 if (code == TS_SIGABRT) signame = "ABRT";
9002 if (code == TS_SIGALRM) signame = "ALRM";
9003 if (code == TS_SIGFPE) signame = "FPE";
9004 if (code == TS_SIGHUP) signame = "HUP";
9005 if (code == TS_SIGILL) signame = "ILL";
9006 if (code == TS_SIGINT) signame = "INT";
9007 if (code == TS_SIGKILL) signame = "KILL";
9008 if (code == TS_SIGPIPE) signame = "PIPE";
9009 if (code == TS_SIGQUIT) signame = "QUIT";
9010 if (code == TS_SIGSEGV) signame = "SEGV";
9011 if (code == TS_SIGTERM) signame = "TERM";
9012 if (code == TS_SIGUSR1) signame = "USR1";
9013 if (code == TS_SIGUSR2) signame = "USR2";
9014 /* The SSH-2 protocol does in principle support arbitrary named
9015 * signals, including signame@domain, but we don't support those. */
9017 /* It's a signal. */
9018 if (ssh->version == 2 && ssh->mainchan) {
9019 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
9020 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
9021 ssh2_pkt_addstring(pktout, "signal");
9022 ssh2_pkt_addbool(pktout, 0);
9023 ssh2_pkt_addstring(pktout, signame);
9024 ssh2_pkt_send(ssh, pktout);
9025 logeventf(ssh, "Sent signal SIG%s", signame);
9028 /* Never heard of it. Do nothing */
9033 void *new_sock_channel(void *handle, Socket s)
9035 Ssh ssh = (Ssh) handle;
9036 struct ssh_channel *c;
9037 c = snew(struct ssh_channel);
9042 c->localid = alloc_channel_id(ssh);
9044 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
9046 bufchain_init(&c->v.v2.outbuffer);
9047 add234(ssh->channels, c);
9053 * This is called when stdout/stderr (the entity to which
9054 * from_backend sends data) manages to clear some backlog.
9056 static void ssh_unthrottle(void *handle, int bufsize)
9058 Ssh ssh = (Ssh) handle;
9059 if (ssh->version == 1) {
9060 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
9061 ssh->v1_stdout_throttling = 0;
9062 ssh1_throttle(ssh, -1);
9065 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
9069 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
9071 struct ssh_channel *c = (struct ssh_channel *)channel;
9073 struct Packet *pktout;
9075 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
9077 if (ssh->version == 1) {
9078 send_packet(ssh, SSH1_MSG_PORT_OPEN,
9079 PKT_INT, c->localid,
9082 /* PKT_STR, <org:orgport>, */
9085 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
9086 ssh2_pkt_addstring(pktout, "direct-tcpip");
9087 ssh2_pkt_adduint32(pktout, c->localid);
9088 c->v.v2.locwindow = OUR_V2_WINSIZE;
9089 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
9090 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
9091 ssh2_pkt_addstring(pktout, hostname);
9092 ssh2_pkt_adduint32(pktout, port);
9094 * We make up values for the originator data; partly it's
9095 * too much hassle to keep track, and partly I'm not
9096 * convinced the server should be told details like that
9097 * about my local network configuration.
9098 * The "originator IP address" is syntactically a numeric
9099 * IP address, and some servers (e.g., Tectia) get upset
9100 * if it doesn't match this syntax.
9102 ssh2_pkt_addstring(pktout, "0.0.0.0");
9103 ssh2_pkt_adduint32(pktout, 0);
9104 ssh2_pkt_send(ssh, pktout);
9108 static int ssh_connected(void *handle)
9110 Ssh ssh = (Ssh) handle;
9111 return ssh->s != NULL;
9114 static int ssh_sendok(void *handle)
9116 Ssh ssh = (Ssh) handle;
9117 return ssh->send_ok;
9120 static int ssh_ldisc(void *handle, int option)
9122 Ssh ssh = (Ssh) handle;
9123 if (option == LD_ECHO)
9124 return ssh->echoing;
9125 if (option == LD_EDIT)
9126 return ssh->editing;
9130 static void ssh_provide_ldisc(void *handle, void *ldisc)
9132 Ssh ssh = (Ssh) handle;
9136 static void ssh_provide_logctx(void *handle, void *logctx)
9138 Ssh ssh = (Ssh) handle;
9139 ssh->logctx = logctx;
9142 static int ssh_return_exitcode(void *handle)
9144 Ssh ssh = (Ssh) handle;
9148 return (ssh->exitcode >= 0 ? ssh->exitcode : INT_MAX);
9152 * cfg_info for SSH is the currently running version of the
9153 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
9155 static int ssh_cfg_info(void *handle)
9157 Ssh ssh = (Ssh) handle;
9158 return ssh->version;
9162 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
9163 * that fails. This variable is the means by which scp.c can reach
9164 * into the SSH code and find out which one it got.
9166 extern int ssh_fallback_cmd(void *handle)
9168 Ssh ssh = (Ssh) handle;
9169 return ssh->fallback_cmd;
9172 Backend ssh_backend = {
9182 ssh_return_exitcode,