17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_KEX_MASK 0x000F
110 #define SSH2_PKTCTX_PUBLICKEY 0x0010
111 #define SSH2_PKTCTX_PASSWORD 0x0020
112 #define SSH2_PKTCTX_KBDINTER 0x0040
113 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_REKEY 64
167 #define BUG_SSH2_PK_SESSIONID 128
170 * Codes for terminal modes.
171 * Most of these are the same in SSH-1 and SSH-2.
172 * This list is derived from draft-ietf-secsh-connect-25 and
175 static const struct {
176 const char* const mode;
178 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
180 /* "V" prefix discarded for special characters relative to SSH specs */
181 { "INTR", 1, TTY_OP_CHAR },
182 { "QUIT", 2, TTY_OP_CHAR },
183 { "ERASE", 3, TTY_OP_CHAR },
184 { "KILL", 4, TTY_OP_CHAR },
185 { "EOF", 5, TTY_OP_CHAR },
186 { "EOL", 6, TTY_OP_CHAR },
187 { "EOL2", 7, TTY_OP_CHAR },
188 { "START", 8, TTY_OP_CHAR },
189 { "STOP", 9, TTY_OP_CHAR },
190 { "SUSP", 10, TTY_OP_CHAR },
191 { "DSUSP", 11, TTY_OP_CHAR },
192 { "REPRINT", 12, TTY_OP_CHAR },
193 { "WERASE", 13, TTY_OP_CHAR },
194 { "LNEXT", 14, TTY_OP_CHAR },
195 { "FLUSH", 15, TTY_OP_CHAR },
196 { "SWTCH", 16, TTY_OP_CHAR },
197 { "STATUS", 17, TTY_OP_CHAR },
198 { "DISCARD", 18, TTY_OP_CHAR },
199 { "IGNPAR", 30, TTY_OP_BOOL },
200 { "PARMRK", 31, TTY_OP_BOOL },
201 { "INPCK", 32, TTY_OP_BOOL },
202 { "ISTRIP", 33, TTY_OP_BOOL },
203 { "INLCR", 34, TTY_OP_BOOL },
204 { "IGNCR", 35, TTY_OP_BOOL },
205 { "ICRNL", 36, TTY_OP_BOOL },
206 { "IUCLC", 37, TTY_OP_BOOL },
207 { "IXON", 38, TTY_OP_BOOL },
208 { "IXANY", 39, TTY_OP_BOOL },
209 { "IXOFF", 40, TTY_OP_BOOL },
210 { "IMAXBEL", 41, TTY_OP_BOOL },
211 { "ISIG", 50, TTY_OP_BOOL },
212 { "ICANON", 51, TTY_OP_BOOL },
213 { "XCASE", 52, TTY_OP_BOOL },
214 { "ECHO", 53, TTY_OP_BOOL },
215 { "ECHOE", 54, TTY_OP_BOOL },
216 { "ECHOK", 55, TTY_OP_BOOL },
217 { "ECHONL", 56, TTY_OP_BOOL },
218 { "NOFLSH", 57, TTY_OP_BOOL },
219 { "TOSTOP", 58, TTY_OP_BOOL },
220 { "IEXTEN", 59, TTY_OP_BOOL },
221 { "ECHOCTL", 60, TTY_OP_BOOL },
222 { "ECHOKE", 61, TTY_OP_BOOL },
223 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
224 { "OPOST", 70, TTY_OP_BOOL },
225 { "OLCUC", 71, TTY_OP_BOOL },
226 { "ONLCR", 72, TTY_OP_BOOL },
227 { "OCRNL", 73, TTY_OP_BOOL },
228 { "ONOCR", 74, TTY_OP_BOOL },
229 { "ONLRET", 75, TTY_OP_BOOL },
230 { "CS7", 90, TTY_OP_BOOL },
231 { "CS8", 91, TTY_OP_BOOL },
232 { "PARENB", 92, TTY_OP_BOOL },
233 { "PARODD", 93, TTY_OP_BOOL }
236 /* Miscellaneous other tty-related constants. */
237 #define SSH_TTY_OP_END 0
238 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
239 #define SSH1_TTY_OP_ISPEED 192
240 #define SSH1_TTY_OP_OSPEED 193
241 #define SSH2_TTY_OP_ISPEED 128
242 #define SSH2_TTY_OP_OSPEED 129
244 /* Helper functions for parsing tty-related config. */
245 static unsigned int ssh_tty_parse_specchar(char *s)
250 ret = ctrlparse(s, &next);
251 if (!next) ret = s[0];
253 ret = 255; /* special value meaning "don't set" */
257 static unsigned int ssh_tty_parse_boolean(char *s)
259 if (stricmp(s, "yes") == 0 ||
260 stricmp(s, "on") == 0 ||
261 stricmp(s, "true") == 0 ||
262 stricmp(s, "+") == 0)
264 else if (stricmp(s, "no") == 0 ||
265 stricmp(s, "off") == 0 ||
266 stricmp(s, "false") == 0 ||
267 stricmp(s, "-") == 0)
268 return 0; /* false */
270 return (atoi(s) != 0);
273 #define translate(x) if (type == x) return #x
274 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
275 static char *ssh1_pkt_type(int type)
277 translate(SSH1_MSG_DISCONNECT);
278 translate(SSH1_SMSG_PUBLIC_KEY);
279 translate(SSH1_CMSG_SESSION_KEY);
280 translate(SSH1_CMSG_USER);
281 translate(SSH1_CMSG_AUTH_RSA);
282 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
283 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
284 translate(SSH1_CMSG_AUTH_PASSWORD);
285 translate(SSH1_CMSG_REQUEST_PTY);
286 translate(SSH1_CMSG_WINDOW_SIZE);
287 translate(SSH1_CMSG_EXEC_SHELL);
288 translate(SSH1_CMSG_EXEC_CMD);
289 translate(SSH1_SMSG_SUCCESS);
290 translate(SSH1_SMSG_FAILURE);
291 translate(SSH1_CMSG_STDIN_DATA);
292 translate(SSH1_SMSG_STDOUT_DATA);
293 translate(SSH1_SMSG_STDERR_DATA);
294 translate(SSH1_CMSG_EOF);
295 translate(SSH1_SMSG_EXIT_STATUS);
296 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
297 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
298 translate(SSH1_MSG_CHANNEL_DATA);
299 translate(SSH1_MSG_CHANNEL_CLOSE);
300 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
301 translate(SSH1_SMSG_X11_OPEN);
302 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
303 translate(SSH1_MSG_PORT_OPEN);
304 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
305 translate(SSH1_SMSG_AGENT_OPEN);
306 translate(SSH1_MSG_IGNORE);
307 translate(SSH1_CMSG_EXIT_CONFIRMATION);
308 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
309 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
310 translate(SSH1_MSG_DEBUG);
311 translate(SSH1_CMSG_REQUEST_COMPRESSION);
312 translate(SSH1_CMSG_AUTH_TIS);
313 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
314 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
315 translate(SSH1_CMSG_AUTH_CCARD);
316 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
317 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
320 static char *ssh2_pkt_type(int pkt_ctx, int type)
322 translate(SSH2_MSG_DISCONNECT);
323 translate(SSH2_MSG_IGNORE);
324 translate(SSH2_MSG_UNIMPLEMENTED);
325 translate(SSH2_MSG_DEBUG);
326 translate(SSH2_MSG_SERVICE_REQUEST);
327 translate(SSH2_MSG_SERVICE_ACCEPT);
328 translate(SSH2_MSG_KEXINIT);
329 translate(SSH2_MSG_NEWKEYS);
330 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
331 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
332 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
333 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
334 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
335 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
336 translate(SSH2_MSG_USERAUTH_REQUEST);
337 translate(SSH2_MSG_USERAUTH_FAILURE);
338 translate(SSH2_MSG_USERAUTH_SUCCESS);
339 translate(SSH2_MSG_USERAUTH_BANNER);
340 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
341 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
342 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
343 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
344 translate(SSH2_MSG_GLOBAL_REQUEST);
345 translate(SSH2_MSG_REQUEST_SUCCESS);
346 translate(SSH2_MSG_REQUEST_FAILURE);
347 translate(SSH2_MSG_CHANNEL_OPEN);
348 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
349 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
350 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
351 translate(SSH2_MSG_CHANNEL_DATA);
352 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
353 translate(SSH2_MSG_CHANNEL_EOF);
354 translate(SSH2_MSG_CHANNEL_CLOSE);
355 translate(SSH2_MSG_CHANNEL_REQUEST);
356 translate(SSH2_MSG_CHANNEL_SUCCESS);
357 translate(SSH2_MSG_CHANNEL_FAILURE);
363 /* Enumeration values for fields in SSH-1 packets */
365 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
366 /* These values are for communicating relevant semantics of
367 * fields to the packet logging code. */
368 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
372 * Coroutine mechanics for the sillier bits of the code. If these
373 * macros look impenetrable to you, you might find it helpful to
376 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
378 * which explains the theory behind these macros.
380 * In particular, if you are getting `case expression not constant'
381 * errors when building with MS Visual Studio, this is because MS's
382 * Edit and Continue debugging feature causes their compiler to
383 * violate ANSI C. To disable Edit and Continue debugging:
385 * - right-click ssh.c in the FileView
387 * - select the C/C++ tab and the General category
388 * - under `Debug info:', select anything _other_ than `Program
389 * Database for Edit and Continue'.
391 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
394 if (!ssh->t) ssh->t = snew(struct t); \
396 #define crFinish(z) } *crLine = 0; return (z); }
397 #define crFinishV } *crLine = 0; return; }
398 #define crReturn(z) \
400 *crLine =__LINE__; return (z); case __LINE__:;\
404 *crLine=__LINE__; return; case __LINE__:;\
406 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
407 #define crStopV do{ *crLine = 0; return; }while(0)
408 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
409 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
411 typedef struct ssh_tag *Ssh;
414 static struct Packet *ssh1_pkt_init(int pkt_type);
415 static struct Packet *ssh2_pkt_init(int pkt_type);
416 static void ssh_pkt_ensure(struct Packet *, int length);
417 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
418 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
419 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
420 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
421 static void ssh_pkt_addstring_start(struct Packet *);
422 static void ssh_pkt_addstring_str(struct Packet *, char *data);
423 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
424 static void ssh_pkt_addstring(struct Packet *, char *data);
425 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
426 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
427 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
428 static int ssh2_pkt_construct(Ssh, struct Packet *);
429 static void ssh2_pkt_send(Ssh, struct Packet *);
430 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
431 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
432 struct Packet *pktin);
433 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
434 struct Packet *pktin);
437 * Buffer management constants. There are several of these for
438 * various different purposes:
440 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
441 * on a local data stream before we throttle the whole SSH
442 * connection (in SSH-1 only). Throttling the whole connection is
443 * pretty drastic so we set this high in the hope it won't
446 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
447 * on the SSH connection itself before we defensively throttle
448 * _all_ local data streams. This is pretty drastic too (though
449 * thankfully unlikely in SSH-2 since the window mechanism should
450 * ensure that the server never has any need to throttle its end
451 * of the connection), so we set this high as well.
453 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
457 #define SSH1_BUFFER_LIMIT 32768
458 #define SSH_MAX_BACKLOG 32768
459 #define OUR_V2_WINSIZE 16384
460 #define OUR_V2_MAXPKT 0x4000UL
462 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
464 const static struct ssh_mac *macs[] = {
467 const static struct ssh_mac *buggymacs[] = {
468 &ssh_sha1_buggy, &ssh_md5
471 static void *ssh_comp_none_init(void)
475 static void ssh_comp_none_cleanup(void *handle)
478 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
479 unsigned char **outblock, int *outlen)
483 static int ssh_comp_none_disable(void *handle)
487 const static struct ssh_compress ssh_comp_none = {
489 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
490 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
491 ssh_comp_none_disable, NULL
493 extern const struct ssh_compress ssh_zlib;
494 const static struct ssh_compress *compressions[] = {
495 &ssh_zlib, &ssh_comp_none
498 enum { /* channel types */
503 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
507 * 2-3-4 tree storing channels.
510 Ssh ssh; /* pointer back to main context */
511 unsigned remoteid, localid;
513 /* True if we opened this channel but server hasn't confirmed. */
516 * In SSH-1, this value contains four bits:
518 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
519 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
520 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
521 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
523 * A channel is completely finished with when all four bits are set.
527 struct ssh1_data_channel {
530 struct ssh2_data_channel {
532 unsigned remwindow, remmaxpkt;
537 struct ssh_agent_channel {
538 unsigned char *message;
539 unsigned char msglen[4];
540 unsigned lensofar, totallen;
542 struct ssh_x11_channel {
545 struct ssh_pfd_channel {
552 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
553 * use this structure in different ways, reflecting SSH-2's
554 * altogether saner approach to port forwarding.
556 * In SSH-1, you arrange a remote forwarding by sending the server
557 * the remote port number, and the local destination host:port.
558 * When a connection comes in, the server sends you back that
559 * host:port pair, and you connect to it. This is a ready-made
560 * security hole if you're not on the ball: a malicious server
561 * could send you back _any_ host:port pair, so if you trustingly
562 * connect to the address it gives you then you've just opened the
563 * entire inside of your corporate network just by connecting
564 * through it to a dodgy SSH server. Hence, we must store a list of
565 * host:port pairs we _are_ trying to forward to, and reject a
566 * connection request from the server if it's not in the list.
568 * In SSH-2, each side of the connection minds its own business and
569 * doesn't send unnecessary information to the other. You arrange a
570 * remote forwarding by sending the server just the remote port
571 * number. When a connection comes in, the server tells you which
572 * of its ports was connected to; and _you_ have to remember what
573 * local host:port pair went with that port number.
575 * Hence, in SSH-1 this structure is indexed by destination
576 * host:port pair, whereas in SSH-2 it is indexed by source port.
578 struct ssh_portfwd; /* forward declaration */
580 struct ssh_rportfwd {
581 unsigned sport, dport;
584 struct ssh_portfwd *pfrec;
586 #define free_rportfwd(pf) ( \
587 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
590 * Separately to the rportfwd tree (which is for looking up port
591 * open requests from the server), a tree of _these_ structures is
592 * used to keep track of all the currently open port forwardings,
593 * so that we can reconfigure in mid-session if the user requests
597 enum { DESTROY, KEEP, CREATE } status;
599 unsigned sport, dport;
602 struct ssh_rportfwd *remote;
606 #define free_portfwd(pf) ( \
607 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
608 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
611 long length; /* length of `data' actually used */
612 long forcepad; /* SSH-2: force padding to at least this length */
613 int type; /* only used for incoming packets */
614 unsigned long sequence; /* SSH-2 incoming sequence number */
615 unsigned char *data; /* allocated storage */
616 unsigned char *body; /* offset of payload within `data' */
617 long savedpos; /* temporary index into `data' (for strings) */
618 long maxlen; /* amount of storage allocated for `data' */
619 long encrypted_len; /* for SSH-2 total-size counting */
622 * State associated with packet logging
626 struct logblank_t *blanks;
629 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
630 struct Packet *pktin);
631 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
632 struct Packet *pktin);
633 static void ssh1_protocol_setup(Ssh ssh);
634 static void ssh2_protocol_setup(Ssh ssh);
635 static void ssh_size(void *handle, int width, int height);
636 static void ssh_special(void *handle, Telnet_Special);
637 static int ssh2_try_send(struct ssh_channel *c);
638 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
639 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
640 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
641 static int ssh_sendbuffer(void *handle);
642 static int ssh_do_close(Ssh ssh, int notify_exit);
643 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
644 static int ssh2_pkt_getbool(struct Packet *pkt);
645 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
646 static void ssh2_timer(void *ctx, long now);
647 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
648 struct Packet *pktin);
650 struct rdpkt1_state_tag {
651 long len, pad, biglen, to_read;
652 unsigned long realcrc, gotcrc;
656 struct Packet *pktin;
659 struct rdpkt2_state_tag {
660 long len, pad, payload, packetlen, maclen;
663 unsigned long incoming_sequence;
664 struct Packet *pktin;
667 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
668 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
670 struct queued_handler;
671 struct queued_handler {
673 chandler_fn_t handler;
675 struct queued_handler *next;
679 const struct plug_function_table *fn;
680 /* the above field _must_ be first in the structure */
682 SHA_State exhash, exhashbase;
689 unsigned char session_key[32];
691 int v1_remote_protoflags;
692 int v1_local_protoflags;
693 int agentfwd_enabled;
696 const struct ssh_cipher *cipher;
699 const struct ssh2_cipher *cscipher, *sccipher;
700 void *cs_cipher_ctx, *sc_cipher_ctx;
701 const struct ssh_mac *csmac, *scmac;
702 void *cs_mac_ctx, *sc_mac_ctx;
703 const struct ssh_compress *cscomp, *sccomp;
704 void *cs_comp_ctx, *sc_comp_ctx;
705 const struct ssh_kex *kex;
706 const struct ssh_signkey *hostkey;
707 unsigned char v2_session_id[20];
713 int echoing, editing;
717 int ospeed, ispeed; /* temporaries */
718 int term_width, term_height;
720 tree234 *channels; /* indexed by local id */
721 struct ssh_channel *mainchan; /* primary session channel */
725 tree234 *rportfwds, *portfwds;
729 SSH_STATE_BEFORE_SIZE,
735 int size_needed, eof_needed;
737 struct Packet **queue;
738 int queuelen, queuesize;
740 unsigned char *deferred_send_data;
741 int deferred_len, deferred_size;
744 * Gross hack: pscp will try to start SFTP but fall back to
745 * scp1 if that fails. This variable is the means by which
746 * scp.c can reach into the SSH code and find out which one it
752 * Used for username and password input.
754 char *userpass_input_buffer;
755 int userpass_input_buflen;
756 int userpass_input_bufpos;
757 int userpass_input_echo;
764 int v1_throttle_count;
767 int v1_stdout_throttling;
768 unsigned long v2_outgoing_sequence;
770 int ssh1_rdpkt_crstate;
771 int ssh2_rdpkt_crstate;
772 int do_ssh_init_crstate;
773 int ssh_gotdata_crstate;
774 int do_ssh1_login_crstate;
775 int do_ssh1_connection_crstate;
776 int do_ssh2_transport_crstate;
777 int do_ssh2_authconn_crstate;
779 void *do_ssh_init_state;
780 void *do_ssh1_login_state;
781 void *do_ssh2_transport_state;
782 void *do_ssh2_authconn_state;
784 struct rdpkt1_state_tag rdpkt1_state;
785 struct rdpkt2_state_tag rdpkt2_state;
787 /* SSH-1 and SSH-2 use this for different things, but both use it */
788 int protocol_initial_phase_done;
790 void (*protocol) (Ssh ssh, void *vin, int inlen,
792 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
795 * We maintain a full _copy_ of a Config structure here, not
796 * merely a pointer to it. That way, when we're passed a new
797 * one for reconfiguration, we can check the differences and
798 * potentially reconfigure port forwardings etc in mid-session.
803 * Used to transfer data back from async callbacks.
805 void *agent_response;
806 int agent_response_len;
810 * The SSH connection can be set as `frozen', meaning we are
811 * not currently accepting incoming data from the network. This
812 * is slightly more serious than setting the _socket_ as
813 * frozen, because we may already have had data passed to us
814 * from the network which we need to delay processing until
815 * after the freeze is lifted, so we also need a bufchain to
819 bufchain queued_incoming_data;
822 * Dispatch table for packet types that we may have to deal
825 handler_fn_t packet_dispatch[256];
828 * Queues of one-off handler functions for success/failure
829 * indications from a request.
831 struct queued_handler *qhead, *qtail;
834 * This module deals with sending keepalives.
839 * Track incoming and outgoing data sizes and time, for
842 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
843 unsigned long max_data_size;
845 long next_rekey, last_rekey;
846 char *deferred_rekey_reason; /* points to STATIC string; don't free */
849 #define logevent(s) logevent(ssh->frontend, s)
851 /* logevent, only printf-formatted. */
852 static void logeventf(Ssh ssh, const char *fmt, ...)
858 buf = dupvprintf(fmt, ap);
864 #define bombout(msg) \
866 char *text = dupprintf msg; \
867 ssh_do_close(ssh, FALSE); \
869 connection_fatal(ssh->frontend, "%s", text); \
873 /* Functions to leave bits out of the SSH packet log file. */
875 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
877 if (ssh->cfg.logomitpass)
878 pkt->logmode = blanktype;
881 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
883 if (ssh->cfg.logomitdata)
884 pkt->logmode = blanktype;
887 static void end_log_omission(Ssh ssh, struct Packet *pkt)
889 pkt->logmode = PKTLOG_EMIT;
892 /* Helper function for common bits of parsing cfg.ttymodes. */
893 static void parse_ttymodes(Ssh ssh, char *modes,
894 void (*do_mode)(void *data, char *mode, char *val),
898 char *t = strchr(modes, '\t');
899 char *m = snewn(t-modes+1, char);
901 strncpy(m, modes, t-modes);
904 val = get_ttymode(ssh->frontend, m);
908 do_mode(data, m, val);
911 modes += strlen(modes) + 1;
915 static int ssh_channelcmp(void *av, void *bv)
917 struct ssh_channel *a = (struct ssh_channel *) av;
918 struct ssh_channel *b = (struct ssh_channel *) bv;
919 if (a->localid < b->localid)
921 if (a->localid > b->localid)
925 static int ssh_channelfind(void *av, void *bv)
927 unsigned *a = (unsigned *) av;
928 struct ssh_channel *b = (struct ssh_channel *) bv;
936 static int ssh_rportcmp_ssh1(void *av, void *bv)
938 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
939 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
941 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
942 return i < 0 ? -1 : +1;
943 if (a->dport > b->dport)
945 if (a->dport < b->dport)
950 static int ssh_rportcmp_ssh2(void *av, void *bv)
952 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
953 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
955 if (a->sport > b->sport)
957 if (a->sport < b->sport)
963 * Special form of strcmp which can cope with NULL inputs. NULL is
964 * defined to sort before even the empty string.
966 static int nullstrcmp(const char *a, const char *b)
968 if (a == NULL && b == NULL)
977 static int ssh_portcmp(void *av, void *bv)
979 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
980 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
982 if (a->type > b->type)
984 if (a->type < b->type)
986 if (a->addressfamily > b->addressfamily)
988 if (a->addressfamily < b->addressfamily)
990 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
991 return i < 0 ? -1 : +1;
992 if (a->sport > b->sport)
994 if (a->sport < b->sport)
996 if (a->type != 'D') {
997 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
998 return i < 0 ? -1 : +1;
999 if (a->dport > b->dport)
1001 if (a->dport < b->dport)
1007 static int alloc_channel_id(Ssh ssh)
1009 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1010 unsigned low, high, mid;
1012 struct ssh_channel *c;
1015 * First-fit allocation of channel numbers: always pick the
1016 * lowest unused one. To do this, binary-search using the
1017 * counted B-tree to find the largest channel ID which is in a
1018 * contiguous sequence from the beginning. (Precisely
1019 * everything in that sequence must have ID equal to its tree
1020 * index plus CHANNEL_NUMBER_OFFSET.)
1022 tsize = count234(ssh->channels);
1026 while (high - low > 1) {
1027 mid = (high + low) / 2;
1028 c = index234(ssh->channels, mid);
1029 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1030 low = mid; /* this one is fine */
1032 high = mid; /* this one is past it */
1035 * Now low points to either -1, or the tree index of the
1036 * largest ID in the initial sequence.
1039 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1040 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1042 return low + 1 + CHANNEL_NUMBER_OFFSET;
1045 static void c_write(Ssh ssh, const char *buf, int len)
1047 if ((flags & FLAG_STDERR)) {
1049 for (i = 0; i < len; i++)
1051 fputc(buf[i], stderr);
1054 from_backend(ssh->frontend, 1, buf, len);
1057 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1060 for (i = 0; i < len; i++) {
1062 c_write(ssh, "\r\n", 2);
1063 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
1064 c_write(ssh, buf + i, 1);
1068 static void c_write_str(Ssh ssh, const char *buf)
1070 c_write(ssh, buf, strlen(buf));
1073 static void ssh_free_packet(struct Packet *pkt)
1078 static struct Packet *ssh_new_packet(void)
1080 struct Packet *pkt = snew(struct Packet);
1082 pkt->body = pkt->data = NULL;
1084 pkt->logmode = PKTLOG_EMIT;
1092 * Collect incoming data in the incoming packet buffer.
1093 * Decipher and verify the packet when it is completely read.
1094 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1095 * Update the *data and *datalen variables.
1096 * Return a Packet structure when a packet is completed.
1098 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1100 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1102 crBegin(ssh->ssh1_rdpkt_crstate);
1104 st->pktin = ssh_new_packet();
1106 st->pktin->type = 0;
1107 st->pktin->length = 0;
1109 for (st->i = st->len = 0; st->i < 4; st->i++) {
1110 while ((*datalen) == 0)
1112 st->len = (st->len << 8) + **data;
1113 (*data)++, (*datalen)--;
1116 st->pad = 8 - (st->len % 8);
1117 st->biglen = st->len + st->pad;
1118 st->pktin->length = st->len - 5;
1120 if (st->biglen < 0) {
1121 bombout(("Extremely large packet length from server suggests"
1122 " data stream corruption"));
1123 ssh_free_packet(st->pktin);
1127 st->pktin->maxlen = st->biglen;
1128 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1130 st->to_read = st->biglen;
1131 st->p = st->pktin->data;
1132 while (st->to_read > 0) {
1133 st->chunk = st->to_read;
1134 while ((*datalen) == 0)
1136 if (st->chunk > (*datalen))
1137 st->chunk = (*datalen);
1138 memcpy(st->p, *data, st->chunk);
1140 *datalen -= st->chunk;
1142 st->to_read -= st->chunk;
1145 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1146 st->biglen, NULL)) {
1147 bombout(("Network attack (CRC compensation) detected!"));
1148 ssh_free_packet(st->pktin);
1153 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1155 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1156 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1157 if (st->gotcrc != st->realcrc) {
1158 bombout(("Incorrect CRC received on packet"));
1159 ssh_free_packet(st->pktin);
1163 st->pktin->body = st->pktin->data + st->pad + 1;
1164 st->pktin->savedpos = 0;
1166 if (ssh->v1_compressing) {
1167 unsigned char *decompblk;
1169 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1170 st->pktin->body - 1, st->pktin->length + 1,
1171 &decompblk, &decomplen)) {
1172 bombout(("Zlib decompression encountered invalid data"));
1173 ssh_free_packet(st->pktin);
1177 if (st->pktin->maxlen < st->pad + decomplen) {
1178 st->pktin->maxlen = st->pad + decomplen;
1179 st->pktin->data = sresize(st->pktin->data,
1180 st->pktin->maxlen + APIEXTRA,
1182 st->pktin->body = st->pktin->data + st->pad + 1;
1185 memcpy(st->pktin->body - 1, decompblk, decomplen);
1187 st->pktin->length = decomplen - 1;
1190 st->pktin->type = st->pktin->body[-1];
1193 * Log incoming packet, possibly omitting sensitive fields.
1197 struct logblank_t blank;
1198 if (ssh->cfg.logomitdata) {
1199 int do_blank = FALSE, blank_prefix = 0;
1200 /* "Session data" packets - omit the data field */
1201 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1202 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1203 do_blank = TRUE; blank_prefix = 0;
1204 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1205 do_blank = TRUE; blank_prefix = 4;
1208 blank.offset = blank_prefix;
1209 blank.len = st->pktin->length;
1210 blank.type = PKTLOG_OMIT;
1214 log_packet(ssh->logctx,
1215 PKT_INCOMING, st->pktin->type,
1216 ssh1_pkt_type(st->pktin->type),
1217 st->pktin->body, st->pktin->length,
1221 crFinish(st->pktin);
1224 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1226 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1228 crBegin(ssh->ssh2_rdpkt_crstate);
1230 st->pktin = ssh_new_packet();
1232 st->pktin->type = 0;
1233 st->pktin->length = 0;
1235 st->cipherblk = ssh->sccipher->blksize;
1238 if (st->cipherblk < 8)
1241 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1244 * Acquire and decrypt the first block of the packet. This will
1245 * contain the length and padding details.
1247 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1248 while ((*datalen) == 0)
1250 st->pktin->data[st->i] = *(*data)++;
1255 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1256 st->pktin->data, st->cipherblk);
1259 * Now get the length and padding figures.
1261 st->len = GET_32BIT(st->pktin->data);
1262 st->pad = st->pktin->data[4];
1265 * _Completely_ silly lengths should be stomped on before they
1266 * do us any more damage.
1268 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1269 bombout(("Incoming packet was garbled on decryption"));
1270 ssh_free_packet(st->pktin);
1275 * This enables us to deduce the payload length.
1277 st->payload = st->len - st->pad - 1;
1279 st->pktin->length = st->payload + 5;
1282 * So now we can work out the total packet length.
1284 st->packetlen = st->len + 4;
1285 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1288 * Allocate memory for the rest of the packet.
1290 st->pktin->maxlen = st->packetlen + st->maclen;
1291 st->pktin->data = sresize(st->pktin->data,
1292 st->pktin->maxlen + APIEXTRA,
1296 * Read and decrypt the remainder of the packet.
1298 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1300 while ((*datalen) == 0)
1302 st->pktin->data[st->i] = *(*data)++;
1305 /* Decrypt everything _except_ the MAC. */
1307 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1308 st->pktin->data + st->cipherblk,
1309 st->packetlen - st->cipherblk);
1311 st->pktin->encrypted_len = st->packetlen;
1317 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1318 st->incoming_sequence)) {
1319 bombout(("Incorrect MAC received on packet"));
1320 ssh_free_packet(st->pktin);
1324 st->pktin->sequence = st->incoming_sequence++;
1327 * Decompress packet payload.
1330 unsigned char *newpayload;
1333 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1334 st->pktin->data + 5, st->pktin->length - 5,
1335 &newpayload, &newlen)) {
1336 if (st->pktin->maxlen < newlen + 5) {
1337 st->pktin->maxlen = newlen + 5;
1338 st->pktin->data = sresize(st->pktin->data,
1339 st->pktin->maxlen + APIEXTRA,
1342 st->pktin->length = 5 + newlen;
1343 memcpy(st->pktin->data + 5, newpayload, newlen);
1348 st->pktin->savedpos = 6;
1349 st->pktin->body = st->pktin->data;
1350 st->pktin->type = st->pktin->data[5];
1353 * Log incoming packet, possibly omitting sensitive fields.
1357 struct logblank_t blank;
1358 if (ssh->cfg.logomitdata) {
1359 int do_blank = FALSE, blank_prefix = 0;
1360 /* "Session data" packets - omit the data field */
1361 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1362 do_blank = TRUE; blank_prefix = 4;
1363 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1364 do_blank = TRUE; blank_prefix = 8;
1367 blank.offset = blank_prefix;
1368 blank.len = (st->pktin->length-6) - blank_prefix;
1369 blank.type = PKTLOG_OMIT;
1373 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1374 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1375 st->pktin->data+6, st->pktin->length-6,
1379 crFinish(st->pktin);
1382 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1384 int pad, biglen, i, pktoffs;
1388 * XXX various versions of SC (including 8.8.4) screw up the
1389 * register allocation in this function and use the same register
1390 * (D6) for len and as a temporary, with predictable results. The
1391 * following sledgehammer prevents this.
1398 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1399 ssh1_pkt_type(pkt->data[12]),
1400 pkt->body, pkt->length - (pkt->body - pkt->data),
1401 pkt->nblanks, pkt->blanks);
1402 sfree(pkt->blanks); pkt->blanks = NULL;
1405 if (ssh->v1_compressing) {
1406 unsigned char *compblk;
1408 zlib_compress_block(ssh->cs_comp_ctx,
1409 pkt->data + 12, pkt->length - 12,
1410 &compblk, &complen);
1411 memcpy(pkt->data + 12, compblk, complen);
1413 pkt->length = complen + 12;
1416 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1418 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1419 pad = 8 - (len % 8);
1421 biglen = len + pad; /* len(padding+type+data+CRC) */
1423 for (i = pktoffs; i < 4+8; i++)
1424 pkt->data[i] = random_byte();
1425 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1426 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1427 PUT_32BIT(pkt->data + pktoffs, len);
1430 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1431 pkt->data + pktoffs + 4, biglen);
1433 if (offset_p) *offset_p = pktoffs;
1434 return biglen + 4; /* len(length+padding+type+data+CRC) */
1437 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1439 int len, backlog, offset;
1440 len = s_wrpkt_prepare(ssh, pkt, &offset);
1441 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1442 if (backlog > SSH_MAX_BACKLOG)
1443 ssh_throttle_all(ssh, 1, backlog);
1444 ssh_free_packet(pkt);
1447 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1450 len = s_wrpkt_prepare(ssh, pkt, &offset);
1451 if (ssh->deferred_len + len > ssh->deferred_size) {
1452 ssh->deferred_size = ssh->deferred_len + len + 128;
1453 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1457 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1458 pkt->data + offset, len);
1459 ssh->deferred_len += len;
1460 ssh_free_packet(pkt);
1464 * Construct a SSH-1 packet with the specified contents.
1465 * (This all-at-once interface used to be the only one, but now SSH-1
1466 * packets can also be constructed incrementally.)
1468 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1474 pkt = ssh1_pkt_init(pkttype);
1476 while ((argtype = va_arg(ap, int)) != PKT_END) {
1477 unsigned char *argp, argchar;
1478 unsigned long argint;
1481 /* Actual fields in the packet */
1483 argint = va_arg(ap, int);
1484 ssh_pkt_adduint32(pkt, argint);
1487 argchar = (unsigned char) va_arg(ap, int);
1488 ssh_pkt_addbyte(pkt, argchar);
1491 argp = va_arg(ap, unsigned char *);
1492 arglen = va_arg(ap, int);
1493 ssh_pkt_adddata(pkt, argp, arglen);
1496 argp = va_arg(ap, unsigned char *);
1497 ssh_pkt_addstring(pkt, argp);
1500 bn = va_arg(ap, Bignum);
1501 ssh1_pkt_addmp(pkt, bn);
1503 /* Tokens for modifications to packet logging */
1505 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1508 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1511 end_log_omission(ssh, pkt);
1519 static void send_packet(Ssh ssh, int pkttype, ...)
1523 va_start(ap, pkttype);
1524 pkt = construct_packet(ssh, pkttype, ap);
1529 static void defer_packet(Ssh ssh, int pkttype, ...)
1533 va_start(ap, pkttype);
1534 pkt = construct_packet(ssh, pkttype, ap);
1536 s_wrpkt_defer(ssh, pkt);
1539 static int ssh_versioncmp(char *a, char *b)
1542 unsigned long av, bv;
1544 av = strtoul(a, &ae, 10);
1545 bv = strtoul(b, &be, 10);
1547 return (av < bv ? -1 : +1);
1552 av = strtoul(ae, &ae, 10);
1553 bv = strtoul(be, &be, 10);
1555 return (av < bv ? -1 : +1);
1560 * Utility routines for putting an SSH-protocol `string' and
1561 * `uint32' into a SHA state.
1563 static void sha_string(SHA_State * s, void *str, int len)
1565 unsigned char lenblk[4];
1566 PUT_32BIT(lenblk, len);
1567 SHA_Bytes(s, lenblk, 4);
1568 SHA_Bytes(s, str, len);
1571 static void sha_uint32(SHA_State * s, unsigned i)
1573 unsigned char intblk[4];
1574 PUT_32BIT(intblk, i);
1575 SHA_Bytes(s, intblk, 4);
1579 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1581 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1583 if (pkt->maxlen < length) {
1584 unsigned char *body = pkt->body;
1585 int offset = body ? pkt->data - body : 0;
1586 pkt->maxlen = length + 256;
1587 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1588 if (body) pkt->body = pkt->data + offset;
1591 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1593 if (pkt->logmode != PKTLOG_EMIT) {
1595 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1597 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1598 (pkt->body - pkt->data);
1599 pkt->blanks[pkt->nblanks-1].len = len;
1600 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1603 ssh_pkt_ensure(pkt, pkt->length);
1604 memcpy(pkt->data + pkt->length - len, data, len);
1606 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1608 ssh_pkt_adddata(pkt, &byte, 1);
1610 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1612 ssh_pkt_adddata(pkt, &value, 1);
1614 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1617 PUT_32BIT(x, value);
1618 ssh_pkt_adddata(pkt, x, 4);
1620 static void ssh_pkt_addstring_start(struct Packet *pkt)
1622 ssh_pkt_adduint32(pkt, 0);
1623 pkt->savedpos = pkt->length;
1625 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1627 ssh_pkt_adddata(pkt, data, strlen(data));
1628 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1630 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1632 ssh_pkt_adddata(pkt, data, len);
1633 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1635 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1637 ssh_pkt_addstring_start(pkt);
1638 ssh_pkt_addstring_str(pkt, data);
1640 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1642 int len = ssh1_bignum_length(b);
1643 unsigned char *data = snewn(len, char);
1644 (void) ssh1_write_bignum(data, b);
1645 ssh_pkt_adddata(pkt, data, len);
1648 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1651 int i, n = (bignum_bitcount(b) + 7) / 8;
1652 p = snewn(n + 1, unsigned char);
1654 fatalbox("out of memory");
1656 for (i = 1; i <= n; i++)
1657 p[i] = bignum_byte(b, n - i);
1659 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1661 memmove(p, p + i, n + 1 - i);
1665 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1669 p = ssh2_mpint_fmt(b, &len);
1670 ssh_pkt_addstring_start(pkt);
1671 ssh_pkt_addstring_data(pkt, (char *)p, len);
1675 static struct Packet *ssh1_pkt_init(int pkt_type)
1677 struct Packet *pkt = ssh_new_packet();
1678 pkt->length = 4 + 8; /* space for length + max padding */
1679 ssh_pkt_addbyte(pkt, pkt_type);
1680 pkt->body = pkt->data + pkt->length;
1684 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1685 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1686 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1687 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1688 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1689 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1690 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1691 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1692 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1694 static struct Packet *ssh2_pkt_init(int pkt_type)
1696 struct Packet *pkt = ssh_new_packet();
1699 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1700 pkt->body = pkt->data + pkt->length;
1705 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1706 * put the MAC on it. Final packet, ready to be sent, is stored in
1707 * pkt->data. Total length is returned.
1709 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1711 int cipherblk, maclen, padding, i;
1714 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1715 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1716 pkt->body, pkt->length - (pkt->body - pkt->data),
1717 pkt->nblanks, pkt->blanks);
1718 sfree(pkt->blanks); pkt->blanks = NULL;
1722 * Compress packet payload.
1725 unsigned char *newpayload;
1728 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1730 &newpayload, &newlen)) {
1732 ssh2_pkt_adddata(pkt, newpayload, newlen);
1738 * Add padding. At least four bytes, and must also bring total
1739 * length (minus MAC) up to a multiple of the block size.
1740 * If pkt->forcepad is set, make sure the packet is at least that size
1743 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1744 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1746 if (pkt->length + padding < pkt->forcepad)
1747 padding = pkt->forcepad - pkt->length;
1749 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1750 assert(padding <= 255);
1751 maclen = ssh->csmac ? ssh->csmac->len : 0;
1752 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1753 pkt->data[4] = padding;
1754 for (i = 0; i < padding; i++)
1755 pkt->data[pkt->length + i] = random_byte();
1756 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1758 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1759 pkt->length + padding,
1760 ssh->v2_outgoing_sequence);
1761 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1764 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1765 pkt->data, pkt->length + padding);
1767 pkt->encrypted_len = pkt->length + padding;
1769 /* Ready-to-send packet starts at pkt->data. We return length. */
1770 return pkt->length + padding + maclen;
1774 * Routines called from the main SSH code to send packets. There
1775 * are quite a few of these, because we have two separate
1776 * mechanisms for delaying the sending of packets:
1778 * - In order to send an IGNORE message and a password message in
1779 * a single fixed-length blob, we require the ability to
1780 * concatenate the encrypted forms of those two packets _into_ a
1781 * single blob and then pass it to our <network.h> transport
1782 * layer in one go. Hence, there's a deferment mechanism which
1783 * works after packet encryption.
1785 * - In order to avoid sending any connection-layer messages
1786 * during repeat key exchange, we have to queue up any such
1787 * outgoing messages _before_ they are encrypted (and in
1788 * particular before they're allocated sequence numbers), and
1789 * then send them once we've finished.
1791 * I call these mechanisms `defer' and `queue' respectively, so as
1792 * to distinguish them reasonably easily.
1794 * The functions send_noqueue() and defer_noqueue() free the packet
1795 * structure they are passed. Every outgoing packet goes through
1796 * precisely one of these functions in its life; packets passed to
1797 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1798 * these or get queued, and then when the queue is later emptied
1799 * the packets are all passed to defer_noqueue().
1801 * When using a CBC-mode cipher, it's necessary to ensure that an
1802 * attacker can't provide data to be encrypted using an IV that they
1803 * know. We ensure this by prefixing each packet that might contain
1804 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1805 * mechanism, so in this case send_noqueue() ends up redirecting to
1806 * defer_noqueue(). If you don't like this inefficiency, don't use
1810 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1811 static void ssh_pkt_defersend(Ssh);
1814 * Send an SSH-2 packet immediately, without queuing or deferring.
1816 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1820 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1821 /* We need to send two packets, so use the deferral mechanism. */
1822 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1823 ssh_pkt_defersend(ssh);
1826 len = ssh2_pkt_construct(ssh, pkt);
1827 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1828 if (backlog > SSH_MAX_BACKLOG)
1829 ssh_throttle_all(ssh, 1, backlog);
1831 ssh->outgoing_data_size += pkt->encrypted_len;
1832 if (!ssh->kex_in_progress &&
1833 ssh->max_data_size != 0 &&
1834 ssh->outgoing_data_size > ssh->max_data_size)
1835 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1837 ssh_free_packet(pkt);
1841 * Defer an SSH-2 packet.
1843 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1846 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1847 ssh->deferred_len == 0 && !noignore) {
1849 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1850 * get encrypted with a known IV.
1852 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1853 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1855 len = ssh2_pkt_construct(ssh, pkt);
1856 if (ssh->deferred_len + len > ssh->deferred_size) {
1857 ssh->deferred_size = ssh->deferred_len + len + 128;
1858 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1862 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1863 ssh->deferred_len += len;
1864 ssh->deferred_data_size += pkt->encrypted_len;
1865 ssh_free_packet(pkt);
1869 * Queue an SSH-2 packet.
1871 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1873 assert(ssh->queueing);
1875 if (ssh->queuelen >= ssh->queuesize) {
1876 ssh->queuesize = ssh->queuelen + 32;
1877 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1880 ssh->queue[ssh->queuelen++] = pkt;
1884 * Either queue or send a packet, depending on whether queueing is
1887 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1890 ssh2_pkt_queue(ssh, pkt);
1892 ssh2_pkt_send_noqueue(ssh, pkt);
1897 * Either queue or defer a packet, depending on whether queueing is
1900 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1903 ssh2_pkt_queue(ssh, pkt);
1905 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1910 * Send the whole deferred data block constructed by
1911 * ssh2_pkt_defer() or SSH-1's defer_packet().
1913 * The expected use of the defer mechanism is that you call
1914 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1915 * not currently queueing, this simply sets up deferred_send_data
1916 * and then sends it. If we _are_ currently queueing, the calls to
1917 * ssh2_pkt_defer() put the deferred packets on to the queue
1918 * instead, and therefore ssh_pkt_defersend() has no deferred data
1919 * to send. Hence, there's no need to make it conditional on
1922 static void ssh_pkt_defersend(Ssh ssh)
1925 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1927 ssh->deferred_len = ssh->deferred_size = 0;
1928 sfree(ssh->deferred_send_data);
1929 ssh->deferred_send_data = NULL;
1930 if (backlog > SSH_MAX_BACKLOG)
1931 ssh_throttle_all(ssh, 1, backlog);
1933 ssh->outgoing_data_size += ssh->deferred_data_size;
1934 if (!ssh->kex_in_progress &&
1935 ssh->max_data_size != 0 &&
1936 ssh->outgoing_data_size > ssh->max_data_size)
1937 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1938 ssh->deferred_data_size = 0;
1942 * Send all queued SSH-2 packets. We send them by means of
1943 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1944 * packets that needed to be lumped together.
1946 static void ssh2_pkt_queuesend(Ssh ssh)
1950 assert(!ssh->queueing);
1952 for (i = 0; i < ssh->queuelen; i++)
1953 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
1956 ssh_pkt_defersend(ssh);
1960 void bndebug(char *string, Bignum b)
1964 p = ssh2_mpint_fmt(b, &len);
1965 debug(("%s", string));
1966 for (i = 0; i < len; i++)
1967 debug((" %02x", p[i]));
1973 static void sha_mpint(SHA_State * s, Bignum b)
1977 p = ssh2_mpint_fmt(b, &len);
1978 sha_string(s, p, len);
1983 * Packet decode functions for both SSH-1 and SSH-2.
1985 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1987 unsigned long value;
1988 if (pkt->length - pkt->savedpos < 4)
1989 return 0; /* arrgh, no way to decline (FIXME?) */
1990 value = GET_32BIT(pkt->body + pkt->savedpos);
1994 static int ssh2_pkt_getbool(struct Packet *pkt)
1996 unsigned long value;
1997 if (pkt->length - pkt->savedpos < 1)
1998 return 0; /* arrgh, no way to decline (FIXME?) */
1999 value = pkt->body[pkt->savedpos] != 0;
2003 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2008 if (pkt->length - pkt->savedpos < 4)
2010 len = GET_32BIT(pkt->body + pkt->savedpos);
2015 if (pkt->length - pkt->savedpos < *length)
2017 *p = (char *)(pkt->body + pkt->savedpos);
2018 pkt->savedpos += *length;
2020 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2022 if (pkt->length - pkt->savedpos < length)
2024 pkt->savedpos += length;
2025 return pkt->body + (pkt->savedpos - length);
2027 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2028 unsigned char **keystr)
2032 j = makekey(pkt->body + pkt->savedpos,
2033 pkt->length - pkt->savedpos,
2040 assert(pkt->savedpos < pkt->length);
2044 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2049 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2050 pkt->length - pkt->savedpos, &b);
2058 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2064 ssh_pkt_getstring(pkt, &p, &length);
2069 b = bignum_from_bytes((unsigned char *)p, length);
2074 * Helper function to add an SSH-2 signature blob to a packet.
2075 * Expects to be shown the public key blob as well as the signature
2076 * blob. Normally works just like ssh2_pkt_addstring, but will
2077 * fiddle with the signature packet if necessary for
2078 * BUG_SSH2_RSA_PADDING.
2080 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2081 void *pkblob_v, int pkblob_len,
2082 void *sigblob_v, int sigblob_len)
2084 unsigned char *pkblob = (unsigned char *)pkblob_v;
2085 unsigned char *sigblob = (unsigned char *)sigblob_v;
2087 /* dmemdump(pkblob, pkblob_len); */
2088 /* dmemdump(sigblob, sigblob_len); */
2091 * See if this is in fact an ssh-rsa signature and a buggy
2092 * server; otherwise we can just do this the easy way.
2094 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2095 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2096 int pos, len, siglen;
2099 * Find the byte length of the modulus.
2102 pos = 4+7; /* skip over "ssh-rsa" */
2103 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2104 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2105 pos += 4; /* find modulus itself */
2106 while (len > 0 && pkblob[pos] == 0)
2108 /* debug(("modulus length is %d\n", len)); */
2111 * Now find the signature integer.
2113 pos = 4+7; /* skip over "ssh-rsa" */
2114 siglen = GET_32BIT(sigblob+pos);
2115 /* debug(("signature length is %d\n", siglen)); */
2117 if (len != siglen) {
2118 unsigned char newlen[4];
2119 ssh2_pkt_addstring_start(pkt);
2120 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2121 /* dmemdump(sigblob, pos); */
2122 pos += 4; /* point to start of actual sig */
2123 PUT_32BIT(newlen, len);
2124 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2125 /* dmemdump(newlen, 4); */
2127 while (len-- > siglen) {
2128 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2129 /* dmemdump(newlen, 1); */
2131 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2132 /* dmemdump(sigblob+pos, siglen); */
2136 /* Otherwise fall through and do it the easy way. */
2139 ssh2_pkt_addstring_start(pkt);
2140 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2144 * Examine the remote side's version string and compare it against
2145 * a list of known buggy implementations.
2147 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2149 char *imp; /* pointer to implementation part */
2151 imp += strcspn(imp, "-");
2153 imp += strcspn(imp, "-");
2156 ssh->remote_bugs = 0;
2158 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2159 (ssh->cfg.sshbug_ignore1 == AUTO &&
2160 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2161 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2162 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2163 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2165 * These versions don't support SSH1_MSG_IGNORE, so we have
2166 * to use a different defence against password length
2169 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2170 logevent("We believe remote version has SSH-1 ignore bug");
2173 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2174 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2175 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2177 * These versions need a plain password sent; they can't
2178 * handle having a null and a random length of data after
2181 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2182 logevent("We believe remote version needs a plain SSH-1 password");
2185 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2186 (ssh->cfg.sshbug_rsa1 == AUTO &&
2187 (!strcmp(imp, "Cisco-1.25")))) {
2189 * These versions apparently have no clue whatever about
2190 * RSA authentication and will panic and die if they see
2191 * an AUTH_RSA message.
2193 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2194 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2197 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2198 (ssh->cfg.sshbug_hmac2 == AUTO &&
2199 !wc_match("* VShell", imp) &&
2200 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2201 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2202 wc_match("2.1 *", imp)))) {
2204 * These versions have the HMAC bug.
2206 ssh->remote_bugs |= BUG_SSH2_HMAC;
2207 logevent("We believe remote version has SSH-2 HMAC bug");
2210 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2211 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2212 !wc_match("* VShell", imp) &&
2213 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2215 * These versions have the key-derivation bug (failing to
2216 * include the literal shared secret in the hashes that
2217 * generate the keys).
2219 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2220 logevent("We believe remote version has SSH-2 key-derivation bug");
2223 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2224 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2225 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2226 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2228 * These versions have the SSH-2 RSA padding bug.
2230 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2231 logevent("We believe remote version has SSH-2 RSA padding bug");
2234 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2235 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2236 wc_match("OpenSSH_2.[0-2]*", imp))) {
2238 * These versions have the SSH-2 session-ID bug in
2239 * public-key authentication.
2241 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2242 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2245 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2246 (ssh->cfg.sshbug_rekey2 == AUTO &&
2247 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2248 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2249 wc_match("Sun_SSH_1.0", imp) ||
2250 wc_match("Sun_SSH_1.0.1", imp)))) {
2252 * These versions have the SSH-2 rekey bug.
2254 ssh->remote_bugs |= BUG_SSH2_REKEY;
2255 logevent("We believe remote version has SSH-2 rekey bug");
2260 * The `software version' part of an SSH version string is required
2261 * to contain no spaces or minus signs.
2263 static void ssh_fix_verstring(char *str)
2265 /* Eat "SSH-<protoversion>-". */
2266 assert(*str == 'S'); str++;
2267 assert(*str == 'S'); str++;
2268 assert(*str == 'H'); str++;
2269 assert(*str == '-'); str++;
2270 while (*str && *str != '-') str++;
2271 assert(*str == '-'); str++;
2273 /* Convert minus signs and spaces in the remaining string into
2276 if (*str == '-' || *str == ' ')
2282 static int do_ssh_init(Ssh ssh, unsigned char c)
2284 struct do_ssh_init_state {
2292 crState(do_ssh_init_state);
2294 crBegin(ssh->do_ssh_init_crstate);
2296 /* Search for the string "SSH-" in the input. */
2299 static const int transS[] = { 1, 2, 2, 1 };
2300 static const int transH[] = { 0, 0, 3, 0 };
2301 static const int transminus[] = { 0, 0, 0, -1 };
2303 s->i = transS[s->i];
2305 s->i = transH[s->i];
2307 s->i = transminus[s->i];
2312 crReturn(1); /* get another character */
2316 s->vstring = snewn(s->vstrsize, char);
2317 strcpy(s->vstring, "SSH-");
2321 crReturn(1); /* get another char */
2322 if (s->vslen >= s->vstrsize - 1) {
2324 s->vstring = sresize(s->vstring, s->vstrsize, char);
2326 s->vstring[s->vslen++] = c;
2329 s->version[s->i] = '\0';
2331 } else if (s->i < sizeof(s->version) - 1)
2332 s->version[s->i++] = c;
2333 } else if (c == '\012')
2337 ssh->agentfwd_enabled = FALSE;
2338 ssh->rdpkt2_state.incoming_sequence = 0;
2340 s->vstring[s->vslen] = 0;
2341 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2342 logeventf(ssh, "Server version: %s", s->vstring);
2343 ssh_detect_bugs(ssh, s->vstring);
2346 * Decide which SSH protocol version to support.
2349 /* Anything strictly below "2.0" means protocol 1 is supported. */
2350 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2351 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2352 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2354 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2355 bombout(("SSH protocol version 1 required by user but not provided by server"));
2358 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2359 bombout(("SSH protocol version 2 required by user but not provided by server"));
2366 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2368 * Construct a v2 version string.
2370 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2374 * Construct a v1 version string.
2376 verstring = dupprintf("SSH-%s-%s\012",
2377 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2378 s->version : "1.5"),
2383 ssh_fix_verstring(verstring);
2385 if (ssh->version == 2) {
2387 * Hash our version string and their version string.
2389 SHA_Init(&ssh->exhashbase);
2390 sha_string(&ssh->exhashbase, verstring,
2391 strcspn(verstring, "\015\012"));
2392 sha_string(&ssh->exhashbase, s->vstring,
2393 strcspn(s->vstring, "\015\012"));
2396 * Initialise SSH-2 protocol.
2398 ssh->protocol = ssh2_protocol;
2399 ssh2_protocol_setup(ssh);
2400 ssh->s_rdpkt = ssh2_rdpkt;
2403 * Initialise SSH-1 protocol.
2405 ssh->protocol = ssh1_protocol;
2406 ssh1_protocol_setup(ssh);
2407 ssh->s_rdpkt = ssh1_rdpkt;
2409 logeventf(ssh, "We claim version: %.*s",
2410 strcspn(verstring, "\015\012"), verstring);
2411 sk_write(ssh->s, verstring, strlen(verstring));
2413 if (ssh->version == 2)
2414 do_ssh2_transport(ssh, NULL, -1, NULL);
2417 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2419 update_specials_menu(ssh->frontend);
2420 ssh->state = SSH_STATE_BEFORE_SIZE;
2421 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2428 static void ssh_process_incoming_data(Ssh ssh,
2429 unsigned char **data, int *datalen)
2431 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2433 ssh->protocol(ssh, NULL, 0, pktin);
2434 ssh_free_packet(pktin);
2438 static void ssh_queue_incoming_data(Ssh ssh,
2439 unsigned char **data, int *datalen)
2441 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2446 static void ssh_process_queued_incoming_data(Ssh ssh)
2449 unsigned char *data;
2452 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2453 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2457 while (!ssh->frozen && len > 0)
2458 ssh_process_incoming_data(ssh, &data, &len);
2461 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2465 static void ssh_set_frozen(Ssh ssh, int frozen)
2468 sk_set_frozen(ssh->s, frozen);
2469 ssh->frozen = frozen;
2472 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2474 crBegin(ssh->ssh_gotdata_crstate);
2477 * To begin with, feed the characters one by one to the
2478 * protocol initialisation / selection function do_ssh_init().
2479 * When that returns 0, we're done with the initial greeting
2480 * exchange and can move on to packet discipline.
2483 int ret; /* need not be kept across crReturn */
2485 crReturnV; /* more data please */
2486 ret = do_ssh_init(ssh, *data);
2494 * We emerge from that loop when the initial negotiation is
2495 * over and we have selected an s_rdpkt function. Now pass
2496 * everything to s_rdpkt, and then pass the resulting packets
2497 * to the proper protocol handler.
2503 * Process queued data if there is any.
2505 ssh_process_queued_incoming_data(ssh);
2508 while (datalen > 0) {
2510 ssh_queue_incoming_data(ssh, &data, &datalen);
2512 ssh_process_incoming_data(ssh, &data, &datalen);
2514 if (ssh->state == SSH_STATE_CLOSED)
2522 static int ssh_do_close(Ssh ssh, int notify_exit)
2525 struct ssh_channel *c;
2527 ssh->state = SSH_STATE_CLOSED;
2528 expire_timer_context(ssh);
2533 notify_remote_exit(ssh->frontend);
2538 * Now we must shut down any port- and X-forwarded channels going
2539 * through this connection.
2541 if (ssh->channels) {
2542 while (NULL != (c = index234(ssh->channels, 0))) {
2545 x11_close(c->u.x11.s);
2548 pfd_close(c->u.pfd.s);
2551 del234(ssh->channels, c); /* moving next one to index 0 */
2552 if (ssh->version == 2)
2553 bufchain_clear(&c->v.v2.outbuffer);
2558 * Go through port-forwardings, and close any associated
2559 * listening sockets.
2561 if (ssh->portfwds) {
2562 struct ssh_portfwd *pf;
2563 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2564 /* Dispose of any listening socket. */
2566 pfd_terminate(pf->local);
2567 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2575 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2576 const char *error_msg, int error_code)
2578 Ssh ssh = (Ssh) plug;
2579 char addrbuf[256], *msg;
2581 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2584 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2586 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2592 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2595 Ssh ssh = (Ssh) plug;
2596 int need_notify = ssh_do_close(ssh, FALSE);
2598 if (!error_msg && !ssh->close_expected) {
2599 error_msg = "Server unexpectedly closed network connection";
2603 notify_remote_exit(ssh->frontend);
2606 /* A socket error has occurred. */
2607 logevent(error_msg);
2608 connection_fatal(ssh->frontend, "%s", error_msg);
2610 logevent("Server closed network connection");
2615 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2617 Ssh ssh = (Ssh) plug;
2618 ssh_gotdata(ssh, (unsigned char *)data, len);
2619 if (ssh->state == SSH_STATE_CLOSED) {
2620 ssh_do_close(ssh, TRUE);
2626 static void ssh_sent(Plug plug, int bufsize)
2628 Ssh ssh = (Ssh) plug;
2630 * If the send backlog on the SSH socket itself clears, we
2631 * should unthrottle the whole world if it was throttled.
2633 if (bufsize < SSH_MAX_BACKLOG)
2634 ssh_throttle_all(ssh, 0, bufsize);
2638 * Connect to specified host and port.
2639 * Returns an error message, or NULL on success.
2640 * Also places the canonical host name into `realhost'. It must be
2641 * freed by the caller.
2643 static const char *connect_to_host(Ssh ssh, char *host, int port,
2644 char **realhost, int nodelay, int keepalive)
2646 static const struct plug_function_table fn_table = {
2657 ssh->savedhost = snewn(1 + strlen(host), char);
2658 if (!ssh->savedhost)
2659 fatalbox("Out of memory");
2660 strcpy(ssh->savedhost, host);
2663 port = 22; /* default ssh port */
2664 ssh->savedport = port;
2669 logeventf(ssh, "Looking up host \"%s\"%s", host,
2670 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2671 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2672 addr = name_lookup(host, port, realhost, &ssh->cfg,
2673 ssh->cfg.addressfamily);
2674 if ((err = sk_addr_error(addr)) != NULL) {
2682 ssh->fn = &fn_table;
2683 ssh->s = new_connection(addr, *realhost, port,
2684 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2685 if ((err = sk_socket_error(ssh->s)) != NULL) {
2687 notify_remote_exit(ssh->frontend);
2695 * Throttle or unthrottle the SSH connection.
2697 static void ssh1_throttle(Ssh ssh, int adjust)
2699 int old_count = ssh->v1_throttle_count;
2700 ssh->v1_throttle_count += adjust;
2701 assert(ssh->v1_throttle_count >= 0);
2702 if (ssh->v1_throttle_count && !old_count) {
2703 ssh_set_frozen(ssh, 1);
2704 } else if (!ssh->v1_throttle_count && old_count) {
2705 ssh_set_frozen(ssh, 0);
2710 * Throttle or unthrottle _all_ local data streams (for when sends
2711 * on the SSH connection itself back up).
2713 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2716 struct ssh_channel *c;
2718 if (enable == ssh->throttled_all)
2720 ssh->throttled_all = enable;
2721 ssh->overall_bufsize = bufsize;
2724 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2726 case CHAN_MAINSESSION:
2728 * This is treated separately, outside the switch.
2732 x11_override_throttle(c->u.x11.s, enable);
2735 /* Agent channels require no buffer management. */
2738 pfd_override_throttle(c->u.pfd.s, enable);
2745 * Username and password input, abstracted off into routines
2746 * reusable in several places - even between SSH-1 and SSH-2.
2749 /* Set up a username or password input loop on a given buffer. */
2750 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2752 ssh->userpass_input_buffer = buffer;
2753 ssh->userpass_input_buflen = buflen;
2754 ssh->userpass_input_bufpos = 0;
2755 ssh->userpass_input_echo = echo;
2759 * Process some terminal data in the course of username/password
2760 * input. Returns >0 for success (line of input returned in
2761 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2762 * for inconclusive (keep waiting for more input please).
2764 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2769 switch (c = *in++) {
2772 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2773 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2778 if (ssh->userpass_input_bufpos > 0) {
2779 if (ssh->userpass_input_echo)
2780 c_write_str(ssh, "\b \b");
2781 ssh->userpass_input_bufpos--;
2786 while (ssh->userpass_input_bufpos > 0) {
2787 if (ssh->userpass_input_echo)
2788 c_write_str(ssh, "\b \b");
2789 ssh->userpass_input_bufpos--;
2798 * This simplistic check for printability is disabled
2799 * when we're doing password input, because some people
2800 * have control characters in their passwords.o
2802 if ((!ssh->userpass_input_echo ||
2803 (c >= ' ' && c <= '~') ||
2804 ((unsigned char) c >= 160))
2805 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2806 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2807 if (ssh->userpass_input_echo)
2808 c_write(ssh, &c, 1);
2816 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2818 Ssh ssh = (Ssh) sshv;
2820 ssh->agent_response = reply;
2821 ssh->agent_response_len = replylen;
2823 if (ssh->version == 1)
2824 do_ssh1_login(ssh, NULL, -1, NULL);
2826 do_ssh2_authconn(ssh, NULL, -1, NULL);
2829 static void ssh_dialog_callback(void *sshv, int ret)
2831 Ssh ssh = (Ssh) sshv;
2833 ssh->user_response = ret;
2835 if (ssh->version == 1)
2836 do_ssh1_login(ssh, NULL, -1, NULL);
2838 do_ssh2_transport(ssh, NULL, -1, NULL);
2841 * This may have unfrozen the SSH connection, so do a
2844 ssh_process_queued_incoming_data(ssh);
2847 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2849 struct ssh_channel *c = (struct ssh_channel *)cv;
2851 void *sentreply = reply;
2854 /* Fake SSH_AGENT_FAILURE. */
2855 sentreply = "\0\0\0\1\5";
2858 if (ssh->version == 2) {
2859 ssh2_add_channel_data(c, sentreply, replylen);
2862 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2863 PKT_INT, c->remoteid,
2866 PKT_DATA, sentreply, replylen,
2875 * Handle the key exchange and user authentication phases.
2877 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2878 struct Packet *pktin)
2881 unsigned char cookie[8], *ptr;
2882 struct RSAKey servkey, hostkey;
2883 struct MD5Context md5c;
2884 struct do_ssh1_login_state {
2886 unsigned char *rsabuf, *keystr1, *keystr2;
2887 unsigned long supported_ciphers_mask, supported_auths_mask;
2888 int tried_publickey, tried_agent;
2889 int tis_auth_refused, ccard_auth_refused;
2890 unsigned char session_id[16];
2893 void *publickey_blob;
2894 int publickey_bloblen;
2900 unsigned char request[5], *response, *p;
2910 crState(do_ssh1_login_state);
2912 crBegin(ssh->do_ssh1_login_crstate);
2917 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2918 bombout(("Public key packet not received"));
2922 logevent("Received public keys");
2924 ptr = ssh_pkt_getdata(pktin, 8);
2926 bombout(("SSH-1 public key packet stopped before random cookie"));
2929 memcpy(cookie, ptr, 8);
2931 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2932 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2933 bombout(("Failed to read SSH-1 public keys from public key packet"));
2938 * Log the host key fingerprint.
2942 logevent("Host key fingerprint is:");
2943 strcpy(logmsg, " ");
2944 hostkey.comment = NULL;
2945 rsa_fingerprint(logmsg + strlen(logmsg),
2946 sizeof(logmsg) - strlen(logmsg), &hostkey);
2950 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2951 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2952 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2954 ssh->v1_local_protoflags =
2955 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2956 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2959 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2960 MD5Update(&md5c, s->keystr1, servkey.bytes);
2961 MD5Update(&md5c, cookie, 8);
2962 MD5Final(s->session_id, &md5c);
2964 for (i = 0; i < 32; i++)
2965 ssh->session_key[i] = random_byte();
2968 * Verify that the `bits' and `bytes' parameters match.
2970 if (hostkey.bits > hostkey.bytes * 8 ||
2971 servkey.bits > servkey.bytes * 8) {
2972 bombout(("SSH-1 public keys were badly formatted"));
2976 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2978 s->rsabuf = snewn(s->len, unsigned char);
2980 fatalbox("Out of memory");
2983 * Verify the host key.
2987 * First format the key into a string.
2989 int len = rsastr_len(&hostkey);
2990 char fingerprint[100];
2991 char *keystr = snewn(len, char);
2993 fatalbox("Out of memory");
2994 rsastr_fmt(keystr, &hostkey);
2995 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2997 ssh_set_frozen(ssh, 1);
2998 s->dlgret = verify_ssh_host_key(ssh->frontend,
2999 ssh->savedhost, ssh->savedport,
3000 "rsa", keystr, fingerprint,
3001 ssh_dialog_callback, ssh);
3003 if (s->dlgret < 0) {
3007 bombout(("Unexpected data from server while waiting"
3008 " for user host key response"));
3011 } while (pktin || inlen > 0);
3012 s->dlgret = ssh->user_response;
3014 ssh_set_frozen(ssh, 0);
3016 if (s->dlgret == 0) {
3017 ssh->close_expected = TRUE;
3018 ssh_closing((Plug)ssh, NULL, 0, 0);
3023 for (i = 0; i < 32; i++) {
3024 s->rsabuf[i] = ssh->session_key[i];
3026 s->rsabuf[i] ^= s->session_id[i];
3029 if (hostkey.bytes > servkey.bytes) {
3030 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3032 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3034 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3036 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3039 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3043 logevent("Encrypted session key");
3046 int cipher_chosen = 0, warn = 0;
3047 char *cipher_string = NULL;
3049 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3050 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3051 if (next_cipher == CIPHER_WARN) {
3052 /* If/when we choose a cipher, warn about it */
3054 } else if (next_cipher == CIPHER_AES) {
3055 /* XXX Probably don't need to mention this. */
3056 logevent("AES not supported in SSH-1, skipping");
3058 switch (next_cipher) {
3059 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3060 cipher_string = "3DES"; break;
3061 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3062 cipher_string = "Blowfish"; break;
3063 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3064 cipher_string = "single-DES"; break;
3066 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3070 if (!cipher_chosen) {
3071 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3072 bombout(("Server violates SSH-1 protocol by not "
3073 "supporting 3DES encryption"));
3075 /* shouldn't happen */
3076 bombout(("No supported ciphers found"));
3080 /* Warn about chosen cipher if necessary. */
3082 ssh_set_frozen(ssh, 1);
3083 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3084 ssh_dialog_callback, ssh);
3085 if (s->dlgret < 0) {
3089 bombout(("Unexpected data from server while waiting"
3090 " for user response"));
3093 } while (pktin || inlen > 0);
3094 s->dlgret = ssh->user_response;
3096 ssh_set_frozen(ssh, 0);
3097 if (s->dlgret == 0) {
3098 ssh->close_expected = TRUE;
3099 ssh_closing((Plug)ssh, NULL, 0, 0);
3105 switch (s->cipher_type) {
3106 case SSH_CIPHER_3DES:
3107 logevent("Using 3DES encryption");
3109 case SSH_CIPHER_DES:
3110 logevent("Using single-DES encryption");
3112 case SSH_CIPHER_BLOWFISH:
3113 logevent("Using Blowfish encryption");
3117 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3118 PKT_CHAR, s->cipher_type,
3119 PKT_DATA, cookie, 8,
3120 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3121 PKT_DATA, s->rsabuf, s->len,
3122 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3124 logevent("Trying to enable encryption...");
3128 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3129 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3131 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3132 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3133 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3135 ssh->crcda_ctx = crcda_make_context();
3136 logevent("Installing CRC compensation attack detector");
3138 if (servkey.modulus) {
3139 sfree(servkey.modulus);
3140 servkey.modulus = NULL;
3142 if (servkey.exponent) {
3143 sfree(servkey.exponent);
3144 servkey.exponent = NULL;
3146 if (hostkey.modulus) {
3147 sfree(hostkey.modulus);
3148 hostkey.modulus = NULL;
3150 if (hostkey.exponent) {
3151 sfree(hostkey.exponent);
3152 hostkey.exponent = NULL;
3156 if (pktin->type != SSH1_SMSG_SUCCESS) {
3157 bombout(("Encryption not successfully enabled"));
3161 logevent("Successfully started encryption");
3165 if (!*ssh->cfg.username) {
3166 if (ssh_get_line && !ssh_getline_pw_only) {
3167 if (!ssh_get_line("login as: ",
3168 s->username, sizeof(s->username), FALSE)) {
3170 * get_line failed to get a username.
3173 logevent("No username provided. Abandoning session.");
3174 ssh->close_expected = TRUE;
3175 ssh_closing((Plug)ssh, NULL, 0, 0);
3179 int ret; /* need not be kept over crReturn */
3180 c_write_str(ssh, "login as: ");
3183 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3185 crWaitUntil(!pktin);
3186 ret = process_userpass_input(ssh, in, inlen);
3190 c_write_str(ssh, "\r\n");
3193 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3194 s->username[sizeof(s->username)-1] = '\0';
3197 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3199 char userlog[22 + sizeof(s->username)];
3200 sprintf(userlog, "Sent username \"%s\"", s->username);
3202 if (flags & FLAG_INTERACTIVE &&
3203 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3204 strcat(userlog, "\r\n");
3205 c_write_str(ssh, userlog);
3212 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3213 /* We must not attempt PK auth. Pretend we've already tried it. */
3214 s->tried_publickey = s->tried_agent = 1;
3216 s->tried_publickey = s->tried_agent = 0;
3218 s->tis_auth_refused = s->ccard_auth_refused = 0;
3219 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3220 if (!filename_is_null(ssh->cfg.keyfile)) {
3221 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3222 &s->publickey_blob, &s->publickey_bloblen, NULL))
3223 s->publickey_blob = NULL;
3225 s->publickey_blob = NULL;
3227 while (pktin->type == SSH1_SMSG_FAILURE) {
3228 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3230 if (agent_exists() && !s->tried_agent) {
3232 * Attempt RSA authentication using Pageant.
3238 logevent("Pageant is running. Requesting keys.");
3240 /* Request the keys held by the agent. */
3241 PUT_32BIT(s->request, 1);
3242 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3243 if (!agent_query(s->request, 5, &r, &s->responselen,
3244 ssh_agent_callback, ssh)) {
3248 bombout(("Unexpected data from server while waiting"
3249 " for agent response"));
3252 } while (pktin || inlen > 0);
3253 r = ssh->agent_response;
3254 s->responselen = ssh->agent_response_len;
3256 s->response = (unsigned char *) r;
3257 if (s->response && s->responselen >= 5 &&
3258 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3259 s->p = s->response + 5;
3260 s->nkeys = GET_32BIT(s->p);
3262 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3263 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3264 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3265 if (s->publickey_blob &&
3266 !memcmp(s->p, s->publickey_blob,
3267 s->publickey_bloblen)) {
3268 logevent("This key matches configured key file");
3269 s->tried_publickey = 1;
3274 do { /* do while (0) to make breaking easy */
3275 n = ssh1_read_bignum
3276 (s->p, s->responselen-(s->p-s->response),
3281 n = ssh1_read_bignum
3282 (s->p, s->responselen-(s->p-s->response),
3287 if (s->responselen - (s->p-s->response) < 4)
3289 s->commentlen = GET_32BIT(s->p);
3291 if (s->responselen - (s->p-s->response) <
3294 s->commentp = (char *)s->p;
3295 s->p += s->commentlen;
3299 logevent("Pageant key list packet was truncated");
3303 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3304 PKT_BIGNUM, s->key.modulus, PKT_END);
3306 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3307 logevent("Key refused");
3310 logevent("Received RSA challenge");
3311 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3312 bombout(("Server's RSA challenge was badly formatted"));
3317 char *agentreq, *q, *ret;
3320 len = 1 + 4; /* message type, bit count */
3321 len += ssh1_bignum_length(s->key.exponent);
3322 len += ssh1_bignum_length(s->key.modulus);
3323 len += ssh1_bignum_length(s->challenge);
3324 len += 16; /* session id */
3325 len += 4; /* response format */
3326 agentreq = snewn(4 + len, char);
3327 PUT_32BIT(agentreq, len);
3329 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3330 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3332 q += ssh1_write_bignum(q, s->key.exponent);
3333 q += ssh1_write_bignum(q, s->key.modulus);
3334 q += ssh1_write_bignum(q, s->challenge);
3335 memcpy(q, s->session_id, 16);
3337 PUT_32BIT(q, 1); /* response format */
3338 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3339 ssh_agent_callback, ssh)) {
3344 bombout(("Unexpected data from server"
3345 " while waiting for agent"
3349 } while (pktin || inlen > 0);
3350 vret = ssh->agent_response;
3351 retlen = ssh->agent_response_len;
3356 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3357 logevent("Sending Pageant's response");
3358 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3359 PKT_DATA, ret + 5, 16,
3363 if (pktin->type == SSH1_SMSG_SUCCESS) {
3365 ("Pageant's response accepted");
3366 if (flags & FLAG_VERBOSE) {
3367 c_write_str(ssh, "Authenticated using"
3369 c_write(ssh, s->commentp,
3371 c_write_str(ssh, "\" from agent\r\n");
3376 ("Pageant's response not accepted");
3379 ("Pageant failed to answer challenge");
3383 logevent("No reply received from Pageant");
3386 freebn(s->key.exponent);
3387 freebn(s->key.modulus);
3388 freebn(s->challenge);
3397 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3398 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3400 if (ssh->cfg.try_tis_auth &&
3401 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3402 !s->tis_auth_refused) {
3403 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3404 logevent("Requested TIS authentication");
3405 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3407 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3408 logevent("TIS authentication declined");
3409 if (flags & FLAG_INTERACTIVE)
3410 c_write_str(ssh, "TIS authentication refused.\r\n");
3411 s->tis_auth_refused = 1;
3417 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3419 bombout(("TIS challenge packet was badly formed"));
3422 c_write_str(ssh, "Using TIS authentication.\r\n");
3423 logevent("Received TIS challenge");
3424 if (challengelen > sizeof(s->prompt) - 1)
3425 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3426 memcpy(s->prompt, challenge, challengelen);
3427 /* Prompt heuristic comes from OpenSSH */
3428 strncpy(s->prompt + challengelen,
3429 memchr(s->prompt, '\n', challengelen) ?
3430 "": "\r\nResponse: ",
3431 (sizeof s->prompt) - challengelen);
3432 s->prompt[(sizeof s->prompt) - 1] = '\0';
3435 if (ssh->cfg.try_tis_auth &&
3436 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3437 !s->ccard_auth_refused) {
3438 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3439 logevent("Requested CryptoCard authentication");
3440 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3442 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3443 logevent("CryptoCard authentication declined");
3444 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3445 s->ccard_auth_refused = 1;
3451 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3453 bombout(("CryptoCard challenge packet was badly formed"));
3456 c_write_str(ssh, "Using CryptoCard authentication.\r\n");
3457 logevent("Received CryptoCard challenge");
3458 if (challengelen > sizeof(s->prompt) - 1)
3459 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3460 memcpy(s->prompt, challenge, challengelen);
3461 strncpy(s->prompt + challengelen,
3462 memchr(s->prompt, '\n', challengelen) ?
3463 "" : "\r\nResponse: ",
3464 sizeof(s->prompt) - challengelen);
3465 s->prompt[sizeof(s->prompt) - 1] = '\0';
3468 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3469 sprintf(s->prompt, "%.90s@%.90s's password: ",
3470 s->username, ssh->savedhost);
3472 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3473 char *comment = NULL;
3475 if (flags & FLAG_VERBOSE)
3476 c_write_str(ssh, "Trying public key authentication.\r\n");
3477 logeventf(ssh, "Trying public key \"%s\"",
3478 filename_to_str(&ssh->cfg.keyfile));
3479 type = key_type(&ssh->cfg.keyfile);
3480 if (type != SSH_KEYTYPE_SSH1) {
3481 char *msg = dupprintf("Key is of wrong type (%s)",
3482 key_type_to_str(type));
3484 c_write_str(ssh, msg);
3485 c_write_str(ssh, "\r\n");
3487 s->tried_publickey = 1;
3490 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3491 if (flags & FLAG_VERBOSE)
3492 c_write_str(ssh, "No passphrase required.\r\n");
3495 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3500 * Show password prompt, having first obtained it via a TIS
3501 * or CryptoCard exchange if we're doing TIS or CryptoCard
3505 if (!ssh_get_line(s->prompt, s->password,
3506 sizeof(s->password), TRUE)) {
3508 * get_line failed to get a password (for example
3509 * because one was supplied on the command line
3510 * which has already failed to work). Terminate.
3512 send_packet(ssh, SSH1_MSG_DISCONNECT,
3513 PKT_STR, "No more passwords available to try",
3515 logevent("Unable to authenticate");
3516 connection_fatal(ssh->frontend, "Unable to authenticate");
3517 ssh->close_expected = TRUE;
3518 ssh_closing((Plug)ssh, NULL, 0, 0);
3522 /* Prompt may have come from server. We've munged it a bit, so
3523 * we know it to be zero-terminated at least once. */
3524 int ret; /* need not be saved over crReturn */
3525 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3528 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3530 crWaitUntil(!pktin);
3531 ret = process_userpass_input(ssh, in, inlen);
3535 c_write_str(ssh, "\r\n");
3539 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3541 * Try public key authentication with the specified
3544 s->tried_publickey = 1;
3547 const char *error = NULL;
3548 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3551 c_write_str(ssh, "Couldn't load private key from ");
3552 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3553 c_write_str(ssh, " (");
3554 c_write_str(ssh, error);
3555 c_write_str(ssh, ").\r\n");
3556 continue; /* go and try password */
3559 c_write_str(ssh, "Wrong passphrase.\r\n");
3560 s->tried_publickey = 0;
3561 continue; /* try again */
3566 * Send a public key attempt.
3568 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3569 PKT_BIGNUM, s->key.modulus, PKT_END);
3572 if (pktin->type == SSH1_SMSG_FAILURE) {
3573 c_write_str(ssh, "Server refused our public key.\r\n");
3574 continue; /* go and try password */
3576 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3577 bombout(("Bizarre response to offer of public key"));
3583 unsigned char buffer[32];
3584 Bignum challenge, response;
3586 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3587 bombout(("Server's RSA challenge was badly formatted"));
3590 response = rsadecrypt(challenge, &s->key);
3591 freebn(s->key.private_exponent);/* burn the evidence */
3593 for (i = 0; i < 32; i++) {
3594 buffer[i] = bignum_byte(response, 31 - i);
3598 MD5Update(&md5c, buffer, 32);
3599 MD5Update(&md5c, s->session_id, 16);
3600 MD5Final(buffer, &md5c);
3602 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3603 PKT_DATA, buffer, 16, PKT_END);
3610 if (pktin->type == SSH1_SMSG_FAILURE) {
3611 if (flags & FLAG_VERBOSE)
3612 c_write_str(ssh, "Failed to authenticate with"
3613 " our public key.\r\n");
3614 continue; /* go and try password */
3615 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3616 bombout(("Bizarre response to RSA authentication response"));
3620 break; /* we're through! */
3622 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3624 * Defence against traffic analysis: we send a
3625 * whole bunch of packets containing strings of
3626 * different lengths. One of these strings is the
3627 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3628 * The others are all random data in
3629 * SSH1_MSG_IGNORE packets. This way a passive
3630 * listener can't tell which is the password, and
3631 * hence can't deduce the password length.
3633 * Anybody with a password length greater than 16
3634 * bytes is going to have enough entropy in their
3635 * password that a listener won't find it _that_
3636 * much help to know how long it is. So what we'll
3639 * - if password length < 16, we send 15 packets
3640 * containing string lengths 1 through 15
3642 * - otherwise, we let N be the nearest multiple
3643 * of 8 below the password length, and send 8
3644 * packets containing string lengths N through
3645 * N+7. This won't obscure the order of
3646 * magnitude of the password length, but it will
3647 * introduce a bit of extra uncertainty.
3649 * A few servers (the old 1.2.18 through 1.2.22)
3650 * can't deal with SSH1_MSG_IGNORE. For these
3651 * servers, we need an alternative defence. We make
3652 * use of the fact that the password is interpreted
3653 * as a C string: so we can append a NUL, then some
3656 * One server (a Cisco one) can deal with neither
3657 * SSH1_MSG_IGNORE _nor_ a padded password string.
3658 * For this server we are left with no defences
3659 * against password length sniffing.
3661 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3663 * The server can deal with SSH1_MSG_IGNORE, so
3664 * we can use the primary defence.
3666 int bottom, top, pwlen, i;
3669 pwlen = strlen(s->password);
3671 bottom = 0; /* zero length passwords are OK! :-) */
3674 bottom = pwlen & ~7;
3678 assert(pwlen >= bottom && pwlen <= top);
3680 randomstr = snewn(top + 1, char);
3682 for (i = bottom; i <= top; i++) {
3684 defer_packet(ssh, s->pwpkt_type,
3685 PKTT_PASSWORD, PKT_STR, s->password,
3686 PKTT_OTHER, PKT_END);
3688 for (j = 0; j < i; j++) {
3690 randomstr[j] = random_byte();
3691 } while (randomstr[j] == '\0');
3693 randomstr[i] = '\0';
3694 defer_packet(ssh, SSH1_MSG_IGNORE,
3695 PKT_STR, randomstr, PKT_END);
3698 logevent("Sending password with camouflage packets");
3699 ssh_pkt_defersend(ssh);
3702 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3704 * The server can't deal with SSH1_MSG_IGNORE
3705 * but can deal with padded passwords, so we
3706 * can use the secondary defence.
3712 len = strlen(s->password);
3713 if (len < sizeof(string)) {
3715 strcpy(string, s->password);
3716 len++; /* cover the zero byte */
3717 while (len < sizeof(string)) {
3718 string[len++] = (char) random_byte();
3723 logevent("Sending length-padded password");
3724 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3725 PKT_INT, len, PKT_DATA, ss, len,
3726 PKTT_OTHER, PKT_END);
3729 * The server has _both_
3730 * BUG_CHOKES_ON_SSH1_IGNORE and
3731 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3732 * therefore nothing we can do.
3735 len = strlen(s->password);
3736 logevent("Sending unpadded password");
3737 send_packet(ssh, s->pwpkt_type,
3738 PKTT_PASSWORD, PKT_INT, len,
3739 PKT_DATA, s->password, len,
3740 PKTT_OTHER, PKT_END);
3743 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3744 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3747 logevent("Sent password");
3748 memset(s->password, 0, strlen(s->password));
3750 if (pktin->type == SSH1_SMSG_FAILURE) {
3751 if (flags & FLAG_VERBOSE)
3752 c_write_str(ssh, "Access denied\r\n");
3753 logevent("Authentication refused");
3754 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3755 bombout(("Strange packet received, type %d", pktin->type));
3760 logevent("Authentication successful");
3765 void sshfwd_close(struct ssh_channel *c)
3769 if (ssh->state == SSH_STATE_CLOSED)
3772 if (c && !c->closes) {
3774 * If halfopen is true, we have sent
3775 * CHANNEL_OPEN for this channel, but it hasn't even been
3776 * acknowledged by the server. So we must set a close flag
3777 * on it now, and then when the server acks the channel
3778 * open, we can close it then.
3781 if (ssh->version == 1) {
3782 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3785 struct Packet *pktout;
3786 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3787 ssh2_pkt_adduint32(pktout, c->remoteid);
3788 ssh2_pkt_send(ssh, pktout);
3791 c->closes = 1; /* sent MSG_CLOSE */
3792 if (c->type == CHAN_X11) {
3794 logevent("Forwarded X11 connection terminated");
3795 } else if (c->type == CHAN_SOCKDATA ||
3796 c->type == CHAN_SOCKDATA_DORMANT) {
3798 logevent("Forwarded port closed");
3803 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3807 if (ssh->state == SSH_STATE_CLOSED)
3810 if (ssh->version == 1) {
3811 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3812 PKT_INT, c->remoteid,
3814 PKT_INT, len, PKT_DATA, buf, len,
3815 PKTT_OTHER, PKT_END);
3817 * In SSH-1 we can return 0 here - implying that forwarded
3818 * connections are never individually throttled - because
3819 * the only circumstance that can cause throttling will be
3820 * the whole SSH connection backing up, in which case
3821 * _everything_ will be throttled as a whole.
3825 ssh2_add_channel_data(c, buf, len);
3826 return ssh2_try_send(c);
3830 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3834 if (ssh->state == SSH_STATE_CLOSED)
3837 if (ssh->version == 1) {
3838 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3839 c->v.v1.throttling = 0;
3840 ssh1_throttle(ssh, -1);
3843 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3847 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3849 struct queued_handler *qh = ssh->qhead;
3853 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3856 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3857 ssh->packet_dispatch[qh->msg1] = NULL;
3860 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3861 ssh->packet_dispatch[qh->msg2] = NULL;
3865 ssh->qhead = qh->next;
3867 if (ssh->qhead->msg1 > 0) {
3868 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3869 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3871 if (ssh->qhead->msg2 > 0) {
3872 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3873 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3876 ssh->qhead = ssh->qtail = NULL;
3877 ssh->packet_dispatch[pktin->type] = NULL;
3880 qh->handler(ssh, pktin, qh->ctx);
3885 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3886 chandler_fn_t handler, void *ctx)
3888 struct queued_handler *qh;
3890 qh = snew(struct queued_handler);
3893 qh->handler = handler;
3897 if (ssh->qtail == NULL) {
3901 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3902 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3905 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3906 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3909 ssh->qtail->next = qh;
3914 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3916 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3918 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3919 SSH2_MSG_REQUEST_SUCCESS)) {
3920 logeventf(ssh, "Remote port forwarding from %s enabled",
3923 logeventf(ssh, "Remote port forwarding from %s refused",
3926 rpf = del234(ssh->rportfwds, pf);
3932 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3934 const char *portfwd_strptr = cfg->portfwd;
3935 struct ssh_portfwd *epf;
3938 if (!ssh->portfwds) {
3939 ssh->portfwds = newtree234(ssh_portcmp);
3942 * Go through the existing port forwardings and tag them
3943 * with status==DESTROY. Any that we want to keep will be
3944 * re-enabled (status==KEEP) as we go through the
3945 * configuration and find out which bits are the same as
3948 struct ssh_portfwd *epf;
3950 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3951 epf->status = DESTROY;
3954 while (*portfwd_strptr) {
3955 char address_family, type;
3956 int sport,dport,sserv,dserv;
3957 char sports[256], dports[256], saddr[256], host[256];
3960 address_family = 'A';
3962 if (*portfwd_strptr == 'A' ||
3963 *portfwd_strptr == '4' ||
3964 *portfwd_strptr == '6')
3965 address_family = *portfwd_strptr++;
3966 if (*portfwd_strptr == 'L' ||
3967 *portfwd_strptr == 'R' ||
3968 *portfwd_strptr == 'D')
3969 type = *portfwd_strptr++;
3974 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3975 if (*portfwd_strptr == ':') {
3977 * We've seen a colon in the middle of the
3978 * source port number. This means that
3979 * everything we've seen until now is the
3980 * source _address_, so we'll move it into
3981 * saddr and start sports from the beginning
3986 if (ssh->version == 1 && type == 'R') {
3987 logeventf(ssh, "SSH-1 cannot handle remote source address "
3988 "spec \"%s\"; ignoring", sports);
3990 strcpy(saddr, sports);
3993 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
3997 if (*portfwd_strptr == '\t')
4000 while (*portfwd_strptr && *portfwd_strptr != ':') {
4001 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4004 if (*portfwd_strptr == ':')
4007 while (*portfwd_strptr) {
4008 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4012 dport = atoi(dports);
4016 dport = net_service_lookup(dports);
4018 logeventf(ssh, "Service lookup failed for destination"
4019 " port \"%s\"", dports);
4023 while (*portfwd_strptr) portfwd_strptr++;
4027 portfwd_strptr++; /* eat the NUL and move to next one */
4029 sport = atoi(sports);
4033 sport = net_service_lookup(sports);
4035 logeventf(ssh, "Service lookup failed for source"
4036 " port \"%s\"", sports);
4039 if (sport && dport) {
4040 /* Set up a description of the source port. */
4041 struct ssh_portfwd *pfrec, *epfrec;
4043 pfrec = snew(struct ssh_portfwd);
4045 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4046 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4047 pfrec->sport = sport;
4048 pfrec->daddr = *host ? dupstr(host) : NULL;
4049 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4050 pfrec->dport = dport;
4051 pfrec->local = NULL;
4052 pfrec->remote = NULL;
4053 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4054 address_family == '6' ? ADDRTYPE_IPV6 :
4057 epfrec = add234(ssh->portfwds, pfrec);
4058 if (epfrec != pfrec) {
4060 * We already have a port forwarding with precisely
4061 * these parameters. Hence, no need to do anything;
4062 * simply tag the existing one as KEEP.
4064 epfrec->status = KEEP;
4065 free_portfwd(pfrec);
4067 pfrec->status = CREATE;
4073 * Now go through and destroy any port forwardings which were
4076 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4077 if (epf->status == DESTROY) {
4080 message = dupprintf("%s port forwarding from %s%s%d",
4081 epf->type == 'L' ? "local" :
4082 epf->type == 'R' ? "remote" : "dynamic",
4083 epf->saddr ? epf->saddr : "",
4084 epf->saddr ? ":" : "",
4087 if (epf->type != 'D') {
4088 char *msg2 = dupprintf("%s to %s:%d", message,
4089 epf->daddr, epf->dport);
4094 logeventf(ssh, "Cancelling %s", message);
4098 struct ssh_rportfwd *rpf = epf->remote;
4099 struct Packet *pktout;
4102 * Cancel the port forwarding at the server
4105 if (ssh->version == 1) {
4107 * We cannot cancel listening ports on the
4108 * server side in SSH-1! There's no message
4109 * to support it. Instead, we simply remove
4110 * the rportfwd record from the local end
4111 * so that any connections the server tries
4112 * to make on it are rejected.
4115 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4116 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4117 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4119 ssh2_pkt_addstring(pktout, epf->saddr);
4120 } else if (ssh->cfg.rport_acceptall) {
4121 /* XXX: ssh->cfg.rport_acceptall may not represent
4122 * what was used to open the original connection,
4123 * since it's reconfigurable. */
4124 ssh2_pkt_addstring(pktout, "0.0.0.0");
4126 ssh2_pkt_addstring(pktout, "127.0.0.1");
4128 ssh2_pkt_adduint32(pktout, epf->sport);
4129 ssh2_pkt_send(ssh, pktout);
4132 del234(ssh->rportfwds, rpf);
4134 } else if (epf->local) {
4135 pfd_terminate(epf->local);
4138 delpos234(ssh->portfwds, i);
4140 i--; /* so we don't skip one in the list */
4144 * And finally, set up any new port forwardings (status==CREATE).
4146 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4147 if (epf->status == CREATE) {
4148 char *sportdesc, *dportdesc;
4149 sportdesc = dupprintf("%s%s%s%s%d%s",
4150 epf->saddr ? epf->saddr : "",
4151 epf->saddr ? ":" : "",
4152 epf->sserv ? epf->sserv : "",
4153 epf->sserv ? "(" : "",
4155 epf->sserv ? ")" : "");
4156 if (epf->type == 'D') {
4159 dportdesc = dupprintf("%s:%s%s%d%s",
4161 epf->dserv ? epf->dserv : "",
4162 epf->dserv ? "(" : "",
4164 epf->dserv ? ")" : "");
4167 if (epf->type == 'L') {
4168 const char *err = pfd_addforward(epf->daddr, epf->dport,
4169 epf->saddr, epf->sport,
4172 epf->addressfamily);
4174 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4175 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4176 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4177 sportdesc, dportdesc,
4178 err ? " failed: " : "", err ? err : "");
4179 } else if (epf->type == 'D') {
4180 const char *err = pfd_addforward(NULL, -1,
4181 epf->saddr, epf->sport,
4184 epf->addressfamily);
4186 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4187 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4188 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4190 err ? " failed: " : "", err ? err : "");
4192 struct ssh_rportfwd *pf;
4195 * Ensure the remote port forwardings tree exists.
4197 if (!ssh->rportfwds) {
4198 if (ssh->version == 1)
4199 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4201 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4204 pf = snew(struct ssh_rportfwd);
4205 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4206 pf->dhost[lenof(pf->dhost)-1] = '\0';
4207 pf->dport = epf->dport;
4208 pf->sport = epf->sport;
4209 if (add234(ssh->rportfwds, pf) != pf) {
4210 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4211 epf->daddr, epf->dport);
4214 logeventf(ssh, "Requesting remote port %s"
4215 " forward to %s", sportdesc, dportdesc);
4217 pf->sportdesc = sportdesc;
4222 if (ssh->version == 1) {
4223 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4224 PKT_INT, epf->sport,
4225 PKT_STR, epf->daddr,
4226 PKT_INT, epf->dport,
4228 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4230 ssh_rportfwd_succfail, pf);
4232 struct Packet *pktout;
4233 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4234 ssh2_pkt_addstring(pktout, "tcpip-forward");
4235 ssh2_pkt_addbool(pktout, 1);/* want reply */
4237 ssh2_pkt_addstring(pktout, epf->saddr);
4238 } else if (cfg->rport_acceptall) {
4239 ssh2_pkt_addstring(pktout, "0.0.0.0");
4241 ssh2_pkt_addstring(pktout, "127.0.0.1");
4243 ssh2_pkt_adduint32(pktout, epf->sport);
4244 ssh2_pkt_send(ssh, pktout);
4246 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4247 SSH2_MSG_REQUEST_FAILURE,
4248 ssh_rportfwd_succfail, pf);
4257 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4260 int stringlen, bufsize;
4262 ssh_pkt_getstring(pktin, &string, &stringlen);
4263 if (string == NULL) {
4264 bombout(("Incoming terminal data packet was badly formed"));
4268 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4270 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4271 ssh->v1_stdout_throttling = 1;
4272 ssh1_throttle(ssh, +1);
4276 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4278 /* Remote side is trying to open a channel to talk to our
4279 * X-Server. Give them back a local channel number. */
4280 struct ssh_channel *c;
4281 int remoteid = ssh_pkt_getuint32(pktin);
4283 logevent("Received X11 connect request");
4284 /* Refuse if X11 forwarding is disabled. */
4285 if (!ssh->X11_fwd_enabled) {
4286 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4287 PKT_INT, remoteid, PKT_END);
4288 logevent("Rejected X11 connect request");
4290 c = snew(struct ssh_channel);
4293 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4294 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4295 logevent("Opening X11 forward connection failed");
4297 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4298 PKT_INT, remoteid, PKT_END);
4301 ("Opening X11 forward connection succeeded");
4302 c->remoteid = remoteid;
4303 c->halfopen = FALSE;
4304 c->localid = alloc_channel_id(ssh);
4306 c->v.v1.throttling = 0;
4307 c->type = CHAN_X11; /* identify channel type */
4308 add234(ssh->channels, c);
4309 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4310 PKT_INT, c->remoteid, PKT_INT,
4311 c->localid, PKT_END);
4312 logevent("Opened X11 forward channel");
4317 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4319 /* Remote side is trying to open a channel to talk to our
4320 * agent. Give them back a local channel number. */
4321 struct ssh_channel *c;
4322 int remoteid = ssh_pkt_getuint32(pktin);
4324 /* Refuse if agent forwarding is disabled. */
4325 if (!ssh->agentfwd_enabled) {
4326 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4327 PKT_INT, remoteid, PKT_END);
4329 c = snew(struct ssh_channel);
4331 c->remoteid = remoteid;
4332 c->halfopen = FALSE;
4333 c->localid = alloc_channel_id(ssh);
4335 c->v.v1.throttling = 0;
4336 c->type = CHAN_AGENT; /* identify channel type */
4337 c->u.a.lensofar = 0;
4338 add234(ssh->channels, c);
4339 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4340 PKT_INT, c->remoteid, PKT_INT, c->localid,
4345 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4347 /* Remote side is trying to open a channel to talk to a
4348 * forwarded port. Give them back a local channel number. */
4349 struct ssh_channel *c;
4350 struct ssh_rportfwd pf, *pfp;
4355 c = snew(struct ssh_channel);
4358 remoteid = ssh_pkt_getuint32(pktin);
4359 ssh_pkt_getstring(pktin, &host, &hostsize);
4360 port = ssh_pkt_getuint32(pktin);
4362 if (hostsize >= lenof(pf.dhost))
4363 hostsize = lenof(pf.dhost)-1;
4364 memcpy(pf.dhost, host, hostsize);
4365 pf.dhost[hostsize] = '\0';
4367 pfp = find234(ssh->rportfwds, &pf, NULL);
4370 logeventf(ssh, "Rejected remote port open request for %s:%d",
4372 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4373 PKT_INT, remoteid, PKT_END);
4375 logeventf(ssh, "Received remote port open request for %s:%d",
4377 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4378 c, &ssh->cfg, pfp->pfrec->addressfamily);
4380 logeventf(ssh, "Port open failed: %s", e);
4382 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4383 PKT_INT, remoteid, PKT_END);
4385 c->remoteid = remoteid;
4386 c->halfopen = FALSE;
4387 c->localid = alloc_channel_id(ssh);
4389 c->v.v1.throttling = 0;
4390 c->type = CHAN_SOCKDATA; /* identify channel type */
4391 add234(ssh->channels, c);
4392 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4393 PKT_INT, c->remoteid, PKT_INT,
4394 c->localid, PKT_END);
4395 logevent("Forwarded port opened successfully");
4400 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4402 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4403 unsigned int localid = ssh_pkt_getuint32(pktin);
4404 struct ssh_channel *c;
4406 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4407 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4408 c->remoteid = localid;
4409 c->halfopen = FALSE;
4410 c->type = CHAN_SOCKDATA;
4411 c->v.v1.throttling = 0;
4412 pfd_confirm(c->u.pfd.s);
4415 if (c && c->closes) {
4417 * We have a pending close on this channel,
4418 * which we decided on before the server acked
4419 * the channel open. So now we know the
4420 * remoteid, we can close it again.
4422 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4423 PKT_INT, c->remoteid, PKT_END);
4427 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4429 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4430 struct ssh_channel *c;
4432 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4433 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4434 logevent("Forwarded connection refused by server");
4435 pfd_close(c->u.pfd.s);
4436 del234(ssh->channels, c);
4441 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4443 /* Remote side closes a channel. */
4444 unsigned i = ssh_pkt_getuint32(pktin);
4445 struct ssh_channel *c;
4446 c = find234(ssh->channels, &i, ssh_channelfind);
4447 if (c && !c->halfopen) {
4450 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4452 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4453 logevent("Forwarded X11 connection terminated");
4454 assert(c->u.x11.s != NULL);
4455 x11_close(c->u.x11.s);
4458 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4459 logevent("Forwarded port closed");
4460 assert(c->u.pfd.s != NULL);
4461 pfd_close(c->u.pfd.s);
4465 c->closes |= (closetype << 2); /* seen this message */
4466 if (!(c->closes & closetype)) {
4467 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4469 c->closes |= closetype; /* sent it too */
4472 if (c->closes == 15) {
4473 del234(ssh->channels, c);
4477 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4478 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4479 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4484 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4486 /* Data sent down one of our channels. */
4487 int i = ssh_pkt_getuint32(pktin);
4490 struct ssh_channel *c;
4492 ssh_pkt_getstring(pktin, &p, &len);
4494 c = find234(ssh->channels, &i, ssh_channelfind);
4499 bufsize = x11_send(c->u.x11.s, p, len);
4502 bufsize = pfd_send(c->u.pfd.s, p, len);
4505 /* Data for an agent message. Buffer it. */
4507 if (c->u.a.lensofar < 4) {
4508 unsigned int l = min(4 - c->u.a.lensofar, len);
4509 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4513 c->u.a.lensofar += l;
4515 if (c->u.a.lensofar == 4) {
4517 4 + GET_32BIT(c->u.a.msglen);
4518 c->u.a.message = snewn(c->u.a.totallen,
4520 memcpy(c->u.a.message, c->u.a.msglen, 4);
4522 if (c->u.a.lensofar >= 4 && len > 0) {
4524 min(c->u.a.totallen - c->u.a.lensofar,
4526 memcpy(c->u.a.message + c->u.a.lensofar, p,
4530 c->u.a.lensofar += l;
4532 if (c->u.a.lensofar == c->u.a.totallen) {
4535 if (agent_query(c->u.a.message,
4538 ssh_agentf_callback, c))
4539 ssh_agentf_callback(c, reply, replylen);
4540 sfree(c->u.a.message);
4541 c->u.a.lensofar = 0;
4544 bufsize = 0; /* agent channels never back up */
4547 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4548 c->v.v1.throttling = 1;
4549 ssh1_throttle(ssh, +1);
4554 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4556 ssh->exitcode = ssh_pkt_getuint32(pktin);
4557 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4558 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4560 * In case `helpful' firewalls or proxies tack
4561 * extra human-readable text on the end of the
4562 * session which we might mistake for another
4563 * encrypted packet, we close the session once
4564 * we've sent EXIT_CONFIRMATION.
4566 ssh->close_expected = TRUE;
4567 ssh_closing((Plug)ssh, NULL, 0, 0);
4570 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4571 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4573 struct Packet *pktout = (struct Packet *)data;
4575 unsigned int arg = 0;
4576 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4577 if (i == lenof(ssh_ttymodes)) return;
4578 switch (ssh_ttymodes[i].type) {
4580 arg = ssh_tty_parse_specchar(val);
4583 arg = ssh_tty_parse_boolean(val);
4586 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4587 ssh2_pkt_addbyte(pktout, arg);
4591 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4592 struct Packet *pktin)
4594 crBegin(ssh->do_ssh1_connection_crstate);
4596 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4597 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4598 ssh1_smsg_stdout_stderr_data;
4600 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4601 ssh1_msg_channel_open_confirmation;
4602 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4603 ssh1_msg_channel_open_failure;
4604 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4605 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4606 ssh1_msg_channel_close;
4607 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4608 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4610 if (ssh->cfg.agentfwd && agent_exists()) {
4611 logevent("Requesting agent forwarding");
4612 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4616 if (pktin->type != SSH1_SMSG_SUCCESS
4617 && pktin->type != SSH1_SMSG_FAILURE) {
4618 bombout(("Protocol confusion"));
4620 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4621 logevent("Agent forwarding refused");
4623 logevent("Agent forwarding enabled");
4624 ssh->agentfwd_enabled = TRUE;
4625 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4629 if (ssh->cfg.x11_forward) {
4630 char proto[20], data[64];
4631 logevent("Requesting X11 forwarding");
4632 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4633 data, sizeof(data), ssh->cfg.x11_auth);
4634 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4635 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4636 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4637 PKT_STR, proto, PKT_STR, data,
4638 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4641 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4642 PKT_STR, proto, PKT_STR, data, PKT_END);
4647 if (pktin->type != SSH1_SMSG_SUCCESS
4648 && pktin->type != SSH1_SMSG_FAILURE) {
4649 bombout(("Protocol confusion"));
4651 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4652 logevent("X11 forwarding refused");
4654 logevent("X11 forwarding enabled");
4655 ssh->X11_fwd_enabled = TRUE;
4656 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4660 ssh_setup_portfwd(ssh, &ssh->cfg);
4661 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4663 if (!ssh->cfg.nopty) {
4665 /* Unpick the terminal-speed string. */
4666 /* XXX perhaps we should allow no speeds to be sent. */
4667 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4668 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4669 /* Send the pty request. */
4670 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4671 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4672 ssh_pkt_adduint32(pkt, ssh->term_height);
4673 ssh_pkt_adduint32(pkt, ssh->term_width);
4674 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4675 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4676 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4677 ssh1_send_ttymode, (void *)pkt);
4678 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4679 ssh_pkt_adduint32(pkt, ssh->ispeed);
4680 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4681 ssh_pkt_adduint32(pkt, ssh->ospeed);
4682 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4684 ssh->state = SSH_STATE_INTERMED;
4688 if (pktin->type != SSH1_SMSG_SUCCESS
4689 && pktin->type != SSH1_SMSG_FAILURE) {
4690 bombout(("Protocol confusion"));
4692 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4693 c_write_str(ssh, "Server refused to allocate pty\r\n");
4694 ssh->editing = ssh->echoing = 1;
4696 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4697 ssh->ospeed, ssh->ispeed);
4699 ssh->editing = ssh->echoing = 1;
4702 if (ssh->cfg.compression) {
4703 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4707 if (pktin->type != SSH1_SMSG_SUCCESS
4708 && pktin->type != SSH1_SMSG_FAILURE) {
4709 bombout(("Protocol confusion"));
4711 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4712 c_write_str(ssh, "Server refused to compress\r\n");
4714 logevent("Started compression");
4715 ssh->v1_compressing = TRUE;
4716 ssh->cs_comp_ctx = zlib_compress_init();
4717 logevent("Initialised zlib (RFC1950) compression");
4718 ssh->sc_comp_ctx = zlib_decompress_init();
4719 logevent("Initialised zlib (RFC1950) decompression");
4723 * Start the shell or command.
4725 * Special case: if the first-choice command is an SSH-2
4726 * subsystem (hence not usable here) and the second choice
4727 * exists, we fall straight back to that.
4730 char *cmd = ssh->cfg.remote_cmd_ptr;
4732 if (!cmd) cmd = ssh->cfg.remote_cmd;
4734 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4735 cmd = ssh->cfg.remote_cmd_ptr2;
4736 ssh->fallback_cmd = TRUE;
4739 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4741 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4742 logevent("Started session");
4745 ssh->state = SSH_STATE_SESSION;
4746 if (ssh->size_needed)
4747 ssh_size(ssh, ssh->term_width, ssh->term_height);
4748 if (ssh->eof_needed)
4749 ssh_special(ssh, TS_EOF);
4752 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4754 ssh->channels = newtree234(ssh_channelcmp);
4758 * By this point, most incoming packets are already being
4759 * handled by the dispatch table, and we need only pay
4760 * attention to the unusual ones.
4765 if (pktin->type == SSH1_SMSG_SUCCESS) {
4766 /* may be from EXEC_SHELL on some servers */
4767 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4768 /* may be from EXEC_SHELL on some servers
4769 * if no pty is available or in other odd cases. Ignore */
4771 bombout(("Strange packet received: type %d", pktin->type));
4776 int len = min(inlen, 512);
4777 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4778 PKT_INT, len, PKT_DATA, in, len,
4779 PKTT_OTHER, PKT_END);
4790 * Handle the top-level SSH-2 protocol.
4792 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4797 ssh_pkt_getstring(pktin, &msg, &msglen);
4798 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4801 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4803 /* log reason code in disconnect message */
4807 ssh_pkt_getstring(pktin, &msg, &msglen);
4808 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4811 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4813 /* Do nothing, because we're ignoring it! Duhh. */
4816 static void ssh1_protocol_setup(Ssh ssh)
4821 * Most messages are handled by the coroutines.
4823 for (i = 0; i < 256; i++)
4824 ssh->packet_dispatch[i] = NULL;
4827 * These special message types we install handlers for.
4829 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4830 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4831 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4834 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4835 struct Packet *pktin)
4837 unsigned char *in=(unsigned char*)vin;
4838 if (ssh->state == SSH_STATE_CLOSED)
4841 if (pktin && ssh->packet_dispatch[pktin->type]) {
4842 ssh->packet_dispatch[pktin->type](ssh, pktin);
4846 if (!ssh->protocol_initial_phase_done) {
4847 if (do_ssh1_login(ssh, in, inlen, pktin))
4848 ssh->protocol_initial_phase_done = TRUE;
4853 do_ssh1_connection(ssh, in, inlen, pktin);
4857 * Utility routine for decoding comma-separated strings in KEXINIT.
4859 static int in_commasep_string(char *needle, char *haystack, int haylen)
4862 if (!needle || !haystack) /* protect against null pointers */
4864 needlen = strlen(needle);
4867 * Is it at the start of the string?
4869 if (haylen >= needlen && /* haystack is long enough */
4870 !memcmp(needle, haystack, needlen) && /* initial match */
4871 (haylen == needlen || haystack[needlen] == ',')
4872 /* either , or EOS follows */
4876 * If not, search for the next comma and resume after that.
4877 * If no comma found, terminate.
4879 while (haylen > 0 && *haystack != ',')
4880 haylen--, haystack++;
4883 haylen--, haystack++; /* skip over comma itself */
4888 * Similar routine for checking whether we have the first string in a list.
4890 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4893 if (!needle || !haystack) /* protect against null pointers */
4895 needlen = strlen(needle);
4897 * Is it at the start of the string?
4899 if (haylen >= needlen && /* haystack is long enough */
4900 !memcmp(needle, haystack, needlen) && /* initial match */
4901 (haylen == needlen || haystack[needlen] == ',')
4902 /* either , or EOS follows */
4910 * SSH-2 key creation method.
4912 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4913 unsigned char *sessid, char chr,
4914 unsigned char *keyspace)
4917 /* First 20 bytes. */
4919 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4921 SHA_Bytes(&s, H, 20);
4922 SHA_Bytes(&s, &chr, 1);
4923 SHA_Bytes(&s, sessid, 20);
4924 SHA_Final(&s, keyspace);
4925 /* Next 20 bytes. */
4927 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4929 SHA_Bytes(&s, H, 20);
4930 SHA_Bytes(&s, keyspace, 20);
4931 SHA_Final(&s, keyspace + 20);
4935 * Handle the SSH-2 transport layer.
4937 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4938 struct Packet *pktin)
4940 unsigned char *in = (unsigned char *)vin;
4941 struct do_ssh2_transport_state {
4942 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4943 Bignum p, g, e, f, K;
4944 int kex_init_value, kex_reply_value;
4945 const struct ssh_mac **maclist;
4947 const struct ssh2_cipher *cscipher_tobe;
4948 const struct ssh2_cipher *sccipher_tobe;
4949 const struct ssh_mac *csmac_tobe;
4950 const struct ssh_mac *scmac_tobe;
4951 const struct ssh_compress *cscomp_tobe;
4952 const struct ssh_compress *sccomp_tobe;
4953 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4954 int hostkeylen, siglen;
4955 void *hkey; /* actual host key */
4956 unsigned char exchange_hash[20];
4957 int n_preferred_kex;
4958 const struct ssh_kex *preferred_kex[KEX_MAX];
4959 int n_preferred_ciphers;
4960 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4961 const struct ssh_compress *preferred_comp;
4962 int got_session_id, activated_authconn;
4963 struct Packet *pktout;
4968 crState(do_ssh2_transport_state);
4970 crBegin(ssh->do_ssh2_transport_crstate);
4972 s->cscipher_tobe = s->sccipher_tobe = NULL;
4973 s->csmac_tobe = s->scmac_tobe = NULL;
4974 s->cscomp_tobe = s->sccomp_tobe = NULL;
4976 s->got_session_id = s->activated_authconn = FALSE;
4979 * Be prepared to work around the buggy MAC problem.
4981 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4982 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4984 s->maclist = macs, s->nmacs = lenof(macs);
4987 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
4989 int i, j, commalist_started;
4992 * Set up the preferred key exchange. (NULL => warn below here)
4994 s->n_preferred_kex = 0;
4995 for (i = 0; i < KEX_MAX; i++) {
4996 switch (ssh->cfg.ssh_kexlist[i]) {
4998 s->preferred_kex[s->n_preferred_kex++] =
4999 &ssh_diffiehellman_gex;
5002 s->preferred_kex[s->n_preferred_kex++] =
5003 &ssh_diffiehellman_group14;
5006 s->preferred_kex[s->n_preferred_kex++] =
5007 &ssh_diffiehellman_group1;
5010 /* Flag for later. Don't bother if it's the last in
5012 if (i < KEX_MAX - 1) {
5013 s->preferred_kex[s->n_preferred_kex++] = NULL;
5020 * Set up the preferred ciphers. (NULL => warn below here)
5022 s->n_preferred_ciphers = 0;
5023 for (i = 0; i < CIPHER_MAX; i++) {
5024 switch (ssh->cfg.ssh_cipherlist[i]) {
5025 case CIPHER_BLOWFISH:
5026 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5029 if (ssh->cfg.ssh2_des_cbc) {
5030 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5034 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5037 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5039 case CIPHER_ARCFOUR:
5040 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5043 /* Flag for later. Don't bother if it's the last in
5045 if (i < CIPHER_MAX - 1) {
5046 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5053 * Set up preferred compression.
5055 if (ssh->cfg.compression)
5056 s->preferred_comp = &ssh_zlib;
5058 s->preferred_comp = &ssh_comp_none;
5061 * Enable queueing of outgoing auth- or connection-layer
5062 * packets while we are in the middle of a key exchange.
5064 ssh->queueing = TRUE;
5067 * Flag that KEX is in progress.
5069 ssh->kex_in_progress = TRUE;
5072 * Construct and send our key exchange packet.
5074 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5075 for (i = 0; i < 16; i++)
5076 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5077 /* List key exchange algorithms. */
5078 ssh2_pkt_addstring_start(s->pktout);
5079 commalist_started = 0;
5080 for (i = 0; i < s->n_preferred_kex; i++) {
5081 const struct ssh_kex *k = s->preferred_kex[i];
5082 if (!k) continue; /* warning flag */
5083 if (commalist_started)
5084 ssh2_pkt_addstring_str(s->pktout, ",");
5085 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
5086 commalist_started = 1;
5088 /* List server host key algorithms. */
5089 ssh2_pkt_addstring_start(s->pktout);
5090 for (i = 0; i < lenof(hostkey_algs); i++) {
5091 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5092 if (i < lenof(hostkey_algs) - 1)
5093 ssh2_pkt_addstring_str(s->pktout, ",");
5095 /* List client->server encryption algorithms. */
5096 ssh2_pkt_addstring_start(s->pktout);
5097 commalist_started = 0;
5098 for (i = 0; i < s->n_preferred_ciphers; i++) {
5099 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5100 if (!c) continue; /* warning flag */
5101 for (j = 0; j < c->nciphers; j++) {
5102 if (commalist_started)
5103 ssh2_pkt_addstring_str(s->pktout, ",");
5104 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5105 commalist_started = 1;
5108 /* List server->client encryption algorithms. */
5109 ssh2_pkt_addstring_start(s->pktout);
5110 commalist_started = 0;
5111 for (i = 0; i < s->n_preferred_ciphers; i++) {
5112 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5113 if (!c) continue; /* warning flag */
5114 for (j = 0; j < c->nciphers; j++) {
5115 if (commalist_started)
5116 ssh2_pkt_addstring_str(s->pktout, ",");
5117 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5118 commalist_started = 1;
5121 /* List client->server MAC algorithms. */
5122 ssh2_pkt_addstring_start(s->pktout);
5123 for (i = 0; i < s->nmacs; i++) {
5124 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5125 if (i < s->nmacs - 1)
5126 ssh2_pkt_addstring_str(s->pktout, ",");
5128 /* List server->client MAC algorithms. */
5129 ssh2_pkt_addstring_start(s->pktout);
5130 for (i = 0; i < s->nmacs; i++) {
5131 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5132 if (i < s->nmacs - 1)
5133 ssh2_pkt_addstring_str(s->pktout, ",");
5135 /* List client->server compression algorithms. */
5136 ssh2_pkt_addstring_start(s->pktout);
5137 assert(lenof(compressions) > 1);
5138 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5139 for (i = 0; i < lenof(compressions); i++) {
5140 const struct ssh_compress *c = compressions[i];
5141 if (c != s->preferred_comp) {
5142 ssh2_pkt_addstring_str(s->pktout, ",");
5143 ssh2_pkt_addstring_str(s->pktout, c->name);
5146 /* List server->client compression algorithms. */
5147 ssh2_pkt_addstring_start(s->pktout);
5148 assert(lenof(compressions) > 1);
5149 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5150 for (i = 0; i < lenof(compressions); i++) {
5151 const struct ssh_compress *c = compressions[i];
5152 if (c != s->preferred_comp) {
5153 ssh2_pkt_addstring_str(s->pktout, ",");
5154 ssh2_pkt_addstring_str(s->pktout, c->name);
5157 /* List client->server languages. Empty list. */
5158 ssh2_pkt_addstring_start(s->pktout);
5159 /* List server->client languages. Empty list. */
5160 ssh2_pkt_addstring_start(s->pktout);
5161 /* First KEX packet does _not_ follow, because we're not that brave. */
5162 ssh2_pkt_addbool(s->pktout, FALSE);
5164 ssh2_pkt_adduint32(s->pktout, 0);
5167 ssh->exhash = ssh->exhashbase;
5168 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
5170 ssh2_pkt_send_noqueue(ssh, s->pktout);
5174 if (pktin->length > 5)
5175 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
5178 * Now examine the other side's KEXINIT to see what we're up
5182 char *str, *preferred;
5185 if (pktin->type != SSH2_MSG_KEXINIT) {
5186 bombout(("expected key exchange packet from server"));
5190 ssh->hostkey = NULL;
5191 s->cscipher_tobe = NULL;
5192 s->sccipher_tobe = NULL;
5193 s->csmac_tobe = NULL;
5194 s->scmac_tobe = NULL;
5195 s->cscomp_tobe = NULL;
5196 s->sccomp_tobe = NULL;
5197 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5199 pktin->savedpos += 16; /* skip garbage cookie */
5200 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5203 for (i = 0; i < s->n_preferred_kex; i++) {
5204 const struct ssh_kex *k = s->preferred_kex[i];
5208 if (!preferred) preferred = k->name;
5209 if (in_commasep_string(k->name, str, len))
5216 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5217 str ? str : "(null)"));
5221 * Note that the server's guess is considered wrong if it doesn't match
5222 * the first algorithm in our list, even if it's still the algorithm
5225 s->guessok = first_in_commasep_string(preferred, str, len);
5226 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5227 for (i = 0; i < lenof(hostkey_algs); i++) {
5228 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5229 ssh->hostkey = hostkey_algs[i];
5233 s->guessok = s->guessok &&
5234 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5235 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5236 for (i = 0; i < s->n_preferred_ciphers; i++) {
5237 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5239 s->warn_cscipher = TRUE;
5241 for (j = 0; j < c->nciphers; j++) {
5242 if (in_commasep_string(c->list[j]->name, str, len)) {
5243 s->cscipher_tobe = c->list[j];
5248 if (s->cscipher_tobe)
5251 if (!s->cscipher_tobe) {
5252 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5253 str ? str : "(null)"));
5257 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5258 for (i = 0; i < s->n_preferred_ciphers; i++) {
5259 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5261 s->warn_sccipher = TRUE;
5263 for (j = 0; j < c->nciphers; j++) {
5264 if (in_commasep_string(c->list[j]->name, str, len)) {
5265 s->sccipher_tobe = c->list[j];
5270 if (s->sccipher_tobe)
5273 if (!s->sccipher_tobe) {
5274 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5275 str ? str : "(null)"));
5279 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5280 for (i = 0; i < s->nmacs; i++) {
5281 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5282 s->csmac_tobe = s->maclist[i];
5286 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5287 for (i = 0; i < s->nmacs; i++) {
5288 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5289 s->scmac_tobe = s->maclist[i];
5293 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5294 for (i = 0; i < lenof(compressions) + 1; i++) {
5295 const struct ssh_compress *c =
5296 i == 0 ? s->preferred_comp : compressions[i - 1];
5297 if (in_commasep_string(c->name, str, len)) {
5302 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5303 for (i = 0; i < lenof(compressions) + 1; i++) {
5304 const struct ssh_compress *c =
5305 i == 0 ? s->preferred_comp : compressions[i - 1];
5306 if (in_commasep_string(c->name, str, len)) {
5311 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5312 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5313 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5316 ssh_set_frozen(ssh, 1);
5317 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5319 ssh_dialog_callback, ssh);
5320 if (s->dlgret < 0) {
5324 bombout(("Unexpected data from server while"
5325 " waiting for user response"));
5328 } while (pktin || inlen > 0);
5329 s->dlgret = ssh->user_response;
5331 ssh_set_frozen(ssh, 0);
5332 if (s->dlgret == 0) {
5333 ssh->close_expected = TRUE;
5334 ssh_closing((Plug)ssh, NULL, 0, 0);
5339 if (s->warn_cscipher) {
5340 ssh_set_frozen(ssh, 1);
5341 s->dlgret = askalg(ssh->frontend,
5342 "client-to-server cipher",
5343 s->cscipher_tobe->name,
5344 ssh_dialog_callback, ssh);
5345 if (s->dlgret < 0) {
5349 bombout(("Unexpected data from server while"
5350 " waiting for user response"));
5353 } while (pktin || inlen > 0);
5354 s->dlgret = ssh->user_response;
5356 ssh_set_frozen(ssh, 0);
5357 if (s->dlgret == 0) {
5358 ssh->close_expected = TRUE;
5359 ssh_closing((Plug)ssh, NULL, 0, 0);
5364 if (s->warn_sccipher) {
5365 ssh_set_frozen(ssh, 1);
5366 s->dlgret = askalg(ssh->frontend,
5367 "server-to-client cipher",
5368 s->sccipher_tobe->name,
5369 ssh_dialog_callback, ssh);
5370 if (s->dlgret < 0) {
5374 bombout(("Unexpected data from server while"
5375 " waiting for user response"));
5378 } while (pktin || inlen > 0);
5379 s->dlgret = ssh->user_response;
5381 ssh_set_frozen(ssh, 0);
5382 if (s->dlgret == 0) {
5383 ssh->close_expected = TRUE;
5384 ssh_closing((Plug)ssh, NULL, 0, 0);
5389 if (s->ignorepkt) /* first_kex_packet_follows */
5390 crWaitUntil(pktin); /* Ignore packet */
5394 * Work out the number of bits of key we will need from the key
5395 * exchange. We start with the maximum key length of either
5401 csbits = s->cscipher_tobe->keylen;
5402 scbits = s->sccipher_tobe->keylen;
5403 s->nbits = (csbits > scbits ? csbits : scbits);
5405 /* The keys only have 160-bit entropy, since they're based on
5406 * a SHA-1 hash. So cap the key size at 160 bits. */
5411 * If we're doing Diffie-Hellman group exchange, start by
5412 * requesting a group.
5414 if (!ssh->kex->pdata) {
5415 logevent("Doing Diffie-Hellman group exchange");
5416 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5418 * Work out how big a DH group we will need to allow that
5421 s->pbits = 512 << ((s->nbits - 1) / 64);
5422 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5423 ssh2_pkt_adduint32(s->pktout, s->pbits);
5424 ssh2_pkt_send_noqueue(ssh, s->pktout);
5427 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5428 bombout(("expected key exchange group packet from server"));
5431 s->p = ssh2_pkt_getmp(pktin);
5432 s->g = ssh2_pkt_getmp(pktin);
5433 if (!s->p || !s->g) {
5434 bombout(("unable to read mp-ints from incoming group packet"));
5437 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5438 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5439 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5441 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5442 ssh->kex_ctx = dh_setup_group(ssh->kex);
5443 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5444 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5445 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5446 ssh->kex->groupname);
5449 logevent("Doing Diffie-Hellman key exchange");
5451 * Now generate and send e for Diffie-Hellman.
5453 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5454 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5455 s->pktout = ssh2_pkt_init(s->kex_init_value);
5456 ssh2_pkt_addmp(s->pktout, s->e);
5457 ssh2_pkt_send_noqueue(ssh, s->pktout);
5459 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5461 if (pktin->type != s->kex_reply_value) {
5462 bombout(("expected key exchange reply packet from server"));
5465 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5466 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5467 s->f = ssh2_pkt_getmp(pktin);
5469 bombout(("unable to parse key exchange reply packet"));
5472 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5474 s->K = dh_find_K(ssh->kex_ctx, s->f);
5476 /* We assume everything from now on will be quick, and it might
5477 * involve user interaction. */
5478 set_busy_status(ssh->frontend, BUSY_NOT);
5480 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5481 if (ssh->kex == &ssh_diffiehellman_gex) {
5482 sha_uint32(&ssh->exhash, s->pbits);
5483 sha_mpint(&ssh->exhash, s->p);
5484 sha_mpint(&ssh->exhash, s->g);
5486 sha_mpint(&ssh->exhash, s->e);
5487 sha_mpint(&ssh->exhash, s->f);
5488 sha_mpint(&ssh->exhash, s->K);
5489 SHA_Final(&ssh->exhash, s->exchange_hash);
5491 dh_cleanup(ssh->kex_ctx);
5492 ssh->kex_ctx = NULL;
5495 debug(("Exchange hash is:\n"));
5496 dmemdump(s->exchange_hash, 20);
5499 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5501 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5502 (char *)s->exchange_hash, 20)) {
5503 bombout(("Server's host key did not match the signature supplied"));
5508 * Authenticate remote host: verify host key. (We've already
5509 * checked the signature of the exchange hash.)
5511 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5512 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5513 ssh_set_frozen(ssh, 1);
5514 s->dlgret = verify_ssh_host_key(ssh->frontend,
5515 ssh->savedhost, ssh->savedport,
5516 ssh->hostkey->keytype, s->keystr,
5518 ssh_dialog_callback, ssh);
5519 if (s->dlgret < 0) {
5523 bombout(("Unexpected data from server while waiting"
5524 " for user host key response"));
5527 } while (pktin || inlen > 0);
5528 s->dlgret = ssh->user_response;
5530 ssh_set_frozen(ssh, 0);
5531 if (s->dlgret == 0) {
5532 ssh->close_expected = TRUE;
5533 ssh_closing((Plug)ssh, NULL, 0, 0);
5536 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5537 logevent("Host key fingerprint is:");
5538 logevent(s->fingerprint);
5540 sfree(s->fingerprint);
5542 ssh->hostkey->freekey(s->hkey);
5545 * The exchange hash from the very first key exchange is also
5546 * the session id, used in session key construction and
5549 if (!s->got_session_id) {
5550 memcpy(ssh->v2_session_id, s->exchange_hash,
5551 sizeof(s->exchange_hash));
5552 s->got_session_id = TRUE;
5556 * Send SSH2_MSG_NEWKEYS.
5558 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5559 ssh2_pkt_send_noqueue(ssh, s->pktout);
5560 ssh->outgoing_data_size = 0; /* start counting from here */
5563 * We've sent client NEWKEYS, so create and initialise
5564 * client-to-server session keys.
5566 if (ssh->cs_cipher_ctx)
5567 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5568 ssh->cscipher = s->cscipher_tobe;
5569 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5571 if (ssh->cs_mac_ctx)
5572 ssh->csmac->free_context(ssh->cs_mac_ctx);
5573 ssh->csmac = s->csmac_tobe;
5574 ssh->cs_mac_ctx = ssh->csmac->make_context();
5576 if (ssh->cs_comp_ctx)
5577 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5578 ssh->cscomp = s->cscomp_tobe;
5579 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5582 * Set IVs on client-to-server keys. Here we use the exchange
5583 * hash from the _first_ key exchange.
5586 unsigned char keyspace[40];
5587 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5588 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5589 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5590 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5591 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5592 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5595 logeventf(ssh, "Initialised %.200s client->server encryption",
5596 ssh->cscipher->text_name);
5597 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5598 ssh->csmac->text_name);
5599 if (ssh->cscomp->text_name)
5600 logeventf(ssh, "Initialised %s compression",
5601 ssh->cscomp->text_name);
5604 * Now our end of the key exchange is complete, we can send all
5605 * our queued higher-layer packets.
5607 ssh->queueing = FALSE;
5608 ssh2_pkt_queuesend(ssh);
5611 * Expect SSH2_MSG_NEWKEYS from server.
5614 if (pktin->type != SSH2_MSG_NEWKEYS) {
5615 bombout(("expected new-keys packet from server"));
5618 ssh->incoming_data_size = 0; /* start counting from here */
5621 * We've seen server NEWKEYS, so create and initialise
5622 * server-to-client session keys.
5624 if (ssh->sc_cipher_ctx)
5625 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5626 ssh->sccipher = s->sccipher_tobe;
5627 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5629 if (ssh->sc_mac_ctx)
5630 ssh->scmac->free_context(ssh->sc_mac_ctx);
5631 ssh->scmac = s->scmac_tobe;
5632 ssh->sc_mac_ctx = ssh->scmac->make_context();
5634 if (ssh->sc_comp_ctx)
5635 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5636 ssh->sccomp = s->sccomp_tobe;
5637 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5640 * Set IVs on server-to-client keys. Here we use the exchange
5641 * hash from the _first_ key exchange.
5644 unsigned char keyspace[40];
5645 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5646 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5647 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5648 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5649 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5650 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5652 logeventf(ssh, "Initialised %.200s server->client encryption",
5653 ssh->sccipher->text_name);
5654 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5655 ssh->scmac->text_name);
5656 if (ssh->sccomp->text_name)
5657 logeventf(ssh, "Initialised %s decompression",
5658 ssh->sccomp->text_name);
5661 * Free key exchange data.
5665 if (ssh->kex == &ssh_diffiehellman_gex) {
5671 * Key exchange is over. Loop straight back round if we have a
5672 * deferred rekey reason.
5674 if (ssh->deferred_rekey_reason) {
5675 logevent(ssh->deferred_rekey_reason);
5677 ssh->deferred_rekey_reason = NULL;
5678 goto begin_key_exchange;
5682 * Otherwise, schedule a timer for our next rekey.
5684 ssh->kex_in_progress = FALSE;
5685 ssh->last_rekey = GETTICKCOUNT();
5686 if (ssh->cfg.ssh_rekey_time != 0)
5687 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5691 * If this is the first key exchange phase, we must pass the
5692 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5693 * wants to see it but because it will need time to initialise
5694 * itself before it sees an actual packet. In subsequent key
5695 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5696 * it would only confuse the layer above.
5698 if (s->activated_authconn) {
5701 s->activated_authconn = TRUE;
5704 * Now we're encrypting. Begin returning 1 to the protocol main
5705 * function so that other things can run on top of the
5706 * transport. If we ever see a KEXINIT, we must go back to the
5709 * We _also_ go back to the start if we see pktin==NULL and
5710 * inlen==-1, because this is a special signal meaning
5711 * `initiate client-driven rekey', and `in' contains a message
5712 * giving the reason for the rekey.
5714 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5715 (!pktin && inlen == -1))) {
5720 logevent("Server initiated key re-exchange");
5723 * Special case: if the server bug is set that doesn't
5724 * allow rekeying, we give a different log message and
5725 * continue waiting. (If such a server _initiates_ a rekey,
5726 * we process it anyway!)
5728 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5729 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5731 /* Reset the counters, so that at least this message doesn't
5732 * hit the event log _too_ often. */
5733 ssh->outgoing_data_size = 0;
5734 ssh->incoming_data_size = 0;
5735 if (ssh->cfg.ssh_rekey_time != 0) {
5737 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5740 goto wait_for_rekey; /* this is utterly horrid */
5742 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5745 goto begin_key_exchange;
5751 * Add data to an SSH-2 channel output buffer.
5753 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5756 bufchain_add(&c->v.v2.outbuffer, buf, len);
5760 * Attempt to send data on an SSH-2 channel.
5762 static int ssh2_try_send(struct ssh_channel *c)
5765 struct Packet *pktout;
5767 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5770 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5771 if ((unsigned)len > c->v.v2.remwindow)
5772 len = c->v.v2.remwindow;
5773 if ((unsigned)len > c->v.v2.remmaxpkt)
5774 len = c->v.v2.remmaxpkt;
5775 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5776 ssh2_pkt_adduint32(pktout, c->remoteid);
5777 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5778 ssh2_pkt_addstring_start(pktout);
5779 ssh2_pkt_addstring_data(pktout, data, len);
5780 end_log_omission(ssh, pktout);
5781 ssh2_pkt_send(ssh, pktout);
5782 bufchain_consume(&c->v.v2.outbuffer, len);
5783 c->v.v2.remwindow -= len;
5787 * After having sent as much data as we can, return the amount
5790 return bufchain_size(&c->v.v2.outbuffer);
5793 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5797 return; /* don't send on closing channels */
5798 bufsize = ssh2_try_send(c);
5801 case CHAN_MAINSESSION:
5802 /* stdin need not receive an unthrottle
5803 * notification since it will be polled */
5806 x11_unthrottle(c->u.x11.s);
5809 /* agent sockets are request/response and need no
5810 * buffer management */
5813 pfd_unthrottle(c->u.pfd.s);
5820 * Potentially enlarge the window on an SSH-2 channel.
5822 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5827 * Never send WINDOW_ADJUST for a channel that the remote side
5828 * already thinks it's closed; there's no point, since it won't
5829 * be sending any more data anyway.
5835 * Only send a WINDOW_ADJUST if there's significantly more window
5836 * available than the other end thinks there is. This saves us
5837 * sending a WINDOW_ADJUST for every character in a shell session.
5839 * "Significant" is arbitrarily defined as half the window size.
5841 if (newwin > c->v.v2.locwindow * 2) {
5842 struct Packet *pktout;
5844 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5845 ssh2_pkt_adduint32(pktout, c->remoteid);
5846 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5847 ssh2_pkt_send(ssh, pktout);
5848 c->v.v2.locwindow = newwin;
5852 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5854 unsigned i = ssh_pkt_getuint32(pktin);
5855 struct ssh_channel *c;
5856 c = find234(ssh->channels, &i, ssh_channelfind);
5857 if (c && !c->closes) {
5858 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5859 ssh2_try_send_and_unthrottle(c);
5863 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5867 unsigned i = ssh_pkt_getuint32(pktin);
5868 struct ssh_channel *c;
5869 c = find234(ssh->channels, &i, ssh_channelfind);
5871 return; /* nonexistent channel */
5872 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5873 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5874 return; /* extended but not stderr */
5875 ssh_pkt_getstring(pktin, &data, &length);
5878 c->v.v2.locwindow -= length;
5880 case CHAN_MAINSESSION:
5882 from_backend(ssh->frontend, pktin->type ==
5883 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5887 bufsize = x11_send(c->u.x11.s, data, length);
5890 bufsize = pfd_send(c->u.pfd.s, data, length);
5893 while (length > 0) {
5894 if (c->u.a.lensofar < 4) {
5895 unsigned int l = min(4 - c->u.a.lensofar, length);
5896 memcpy(c->u.a.msglen + c->u.a.lensofar,
5900 c->u.a.lensofar += l;
5902 if (c->u.a.lensofar == 4) {
5904 4 + GET_32BIT(c->u.a.msglen);
5905 c->u.a.message = snewn(c->u.a.totallen,
5907 memcpy(c->u.a.message, c->u.a.msglen, 4);
5909 if (c->u.a.lensofar >= 4 && length > 0) {
5911 min(c->u.a.totallen - c->u.a.lensofar,
5913 memcpy(c->u.a.message + c->u.a.lensofar,
5917 c->u.a.lensofar += l;
5919 if (c->u.a.lensofar == c->u.a.totallen) {
5922 if (agent_query(c->u.a.message,
5925 ssh_agentf_callback, c))
5926 ssh_agentf_callback(c, reply, replylen);
5927 sfree(c->u.a.message);
5928 c->u.a.lensofar = 0;
5935 * If we are not buffering too much data,
5936 * enlarge the window again at the remote side.
5938 if (bufsize < OUR_V2_WINSIZE)
5939 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5943 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5945 unsigned i = ssh_pkt_getuint32(pktin);
5946 struct ssh_channel *c;
5948 c = find234(ssh->channels, &i, ssh_channelfind);
5950 return; /* nonexistent channel */
5952 if (c->type == CHAN_X11) {
5954 * Remote EOF on an X11 channel means we should
5955 * wrap up and close the channel ourselves.
5957 x11_close(c->u.x11.s);
5959 } else if (c->type == CHAN_AGENT) {
5961 } else if (c->type == CHAN_SOCKDATA) {
5962 pfd_close(c->u.pfd.s);
5967 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5969 unsigned i = ssh_pkt_getuint32(pktin);
5970 struct ssh_channel *c;
5971 struct Packet *pktout;
5973 c = find234(ssh->channels, &i, ssh_channelfind);
5974 if (!c || c->halfopen) {
5975 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5976 c ? "half-open" : "nonexistent", i));
5979 /* Do pre-close processing on the channel. */
5981 case CHAN_MAINSESSION:
5982 ssh->mainchan = NULL;
5983 update_specials_menu(ssh->frontend);
5986 if (c->u.x11.s != NULL)
5987 x11_close(c->u.x11.s);
5994 if (c->u.pfd.s != NULL)
5995 pfd_close(c->u.pfd.s);
5999 if (c->closes == 0) {
6000 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6001 ssh2_pkt_adduint32(pktout, c->remoteid);
6002 ssh2_pkt_send(ssh, pktout);
6004 del234(ssh->channels, c);
6005 bufchain_clear(&c->v.v2.outbuffer);
6009 * See if that was the last channel left open.
6010 * (This is only our termination condition if we're
6011 * not running in -N mode.)
6013 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6014 logevent("All channels closed. Disconnecting");
6017 * We used to send SSH_MSG_DISCONNECT here,
6018 * because I'd believed that _every_ conforming
6019 * SSH-2 connection had to end with a disconnect
6020 * being sent by at least one side; apparently
6021 * I was wrong and it's perfectly OK to
6022 * unceremoniously slam the connection shut
6023 * when you're done, and indeed OpenSSH feels
6024 * this is more polite than sending a
6025 * DISCONNECT. So now we don't.
6027 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6028 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6029 ssh2_pkt_addstring(s->pktout, "All open channels closed");
6030 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6031 ssh2_pkt_send_noqueue(ssh, s->pktout);
6033 ssh->close_expected = TRUE;
6034 ssh_closing((Plug)ssh, NULL, 0, 0);
6038 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6040 unsigned i = ssh_pkt_getuint32(pktin);
6041 struct ssh_channel *c;
6042 struct Packet *pktout;
6044 c = find234(ssh->channels, &i, ssh_channelfind);
6046 return; /* nonexistent channel */
6047 if (c->type != CHAN_SOCKDATA_DORMANT)
6048 return; /* dunno why they're confirming this */
6049 c->remoteid = ssh_pkt_getuint32(pktin);
6050 c->halfopen = FALSE;
6051 c->type = CHAN_SOCKDATA;
6052 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6053 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6055 pfd_confirm(c->u.pfd.s);
6058 * We have a pending close on this channel,
6059 * which we decided on before the server acked
6060 * the channel open. So now we know the
6061 * remoteid, we can close it again.
6063 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6064 ssh2_pkt_adduint32(pktout, c->remoteid);
6065 ssh2_pkt_send(ssh, pktout);
6069 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6071 static const char *const reasons[] = {
6072 "<unknown reason code>",
6073 "Administratively prohibited",
6075 "Unknown channel type",
6076 "Resource shortage",
6078 unsigned i = ssh_pkt_getuint32(pktin);
6079 unsigned reason_code;
6080 char *reason_string;
6082 struct ssh_channel *c;
6083 c = find234(ssh->channels, &i, ssh_channelfind);
6085 return; /* nonexistent channel */
6086 if (c->type != CHAN_SOCKDATA_DORMANT)
6087 return; /* dunno why they're failing this */
6089 reason_code = ssh_pkt_getuint32(pktin);
6090 if (reason_code >= lenof(reasons))
6091 reason_code = 0; /* ensure reasons[reason_code] in range */
6092 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6093 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6094 reasons[reason_code], reason_length, reason_string);
6096 pfd_close(c->u.pfd.s);
6098 del234(ssh->channels, c);
6102 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6106 int typelen, want_reply;
6107 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6108 struct ssh_channel *c;
6109 struct Packet *pktout;
6111 localid = ssh_pkt_getuint32(pktin);
6112 ssh_pkt_getstring(pktin, &type, &typelen);
6113 want_reply = ssh2_pkt_getbool(pktin);
6116 * First, check that the channel exists. Otherwise,
6117 * we can instantly disconnect with a rude message.
6119 c = find234(ssh->channels, &localid, ssh_channelfind);
6122 sprintf(buf, "Received channel request for nonexistent"
6123 " channel %d", localid);
6125 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6126 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
6127 ssh2_pkt_addstring(pktout, buf);
6128 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6129 ssh2_pkt_send_noqueue(ssh, pktout);
6130 connection_fatal(ssh->frontend, "%s", buf);
6131 ssh->close_expected = TRUE;
6132 ssh_closing((Plug)ssh, NULL, 0, 0);
6137 * Having got the channel number, we now look at
6138 * the request type string to see if it's something
6141 if (c == ssh->mainchan) {
6143 * We recognise "exit-status" and "exit-signal" on
6144 * the primary channel.
6146 if (typelen == 11 &&
6147 !memcmp(type, "exit-status", 11)) {
6149 ssh->exitcode = ssh_pkt_getuint32(pktin);
6150 logeventf(ssh, "Server sent command exit status %d",
6152 reply = SSH2_MSG_CHANNEL_SUCCESS;
6154 } else if (typelen == 11 &&
6155 !memcmp(type, "exit-signal", 11)) {
6157 int is_plausible = TRUE, is_int = FALSE;
6158 char *fmt_sig = "", *fmt_msg = "";
6160 int msglen = 0, core = FALSE;
6161 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6162 * provide an `int' for the signal, despite its
6163 * having been a `string' in the drafts since at
6164 * least 2001. (Fixed in session.c 1.147.) Try to
6165 * infer which we can safely parse it as. */
6167 unsigned char *p = pktin->body +
6169 long len = pktin->length - pktin->savedpos;
6170 unsigned long num = GET_32BIT(p); /* what is it? */
6171 /* If it's 0, it hardly matters; assume string */
6175 int maybe_int = FALSE, maybe_str = FALSE;
6176 #define CHECK_HYPOTHESIS(offset, result) \
6179 if (q >= 0 && q+4 <= len) { \
6180 q = q + 4 + GET_32BIT(p+q); \
6181 if (q >= 0 && q+4 <= len && \
6182 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6186 CHECK_HYPOTHESIS(4+1, maybe_int);
6187 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6188 #undef CHECK_HYPOTHESIS
6189 if (maybe_int && !maybe_str)
6191 else if (!maybe_int && maybe_str)
6194 /* Crikey. Either or neither. Panic. */
6195 is_plausible = FALSE;
6200 /* Old non-standard OpenSSH. */
6201 int signum = ssh_pkt_getuint32(pktin);
6202 fmt_sig = dupprintf(" %d", signum);
6204 /* As per the drafts. */
6207 ssh_pkt_getstring(pktin, &sig, &siglen);
6208 /* Signal name isn't supposed to be blank, but
6209 * let's cope gracefully if it is. */
6211 fmt_sig = dupprintf(" \"%.*s\"",
6215 core = ssh2_pkt_getbool(pktin);
6216 ssh_pkt_getstring(pktin, &msg, &msglen);
6218 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6220 /* ignore lang tag */
6221 } /* else don't attempt to parse */
6222 logeventf(ssh, "Server exited on signal%s%s%s",
6223 fmt_sig, core ? " (core dumped)" : "",
6225 if (*fmt_sig) sfree(fmt_sig);
6226 if (*fmt_msg) sfree(fmt_msg);
6227 reply = SSH2_MSG_CHANNEL_SUCCESS;
6232 * This is a channel request we don't know
6233 * about, so we now either ignore the request
6234 * or respond with CHANNEL_FAILURE, depending
6237 reply = SSH2_MSG_CHANNEL_FAILURE;
6240 pktout = ssh2_pkt_init(reply);
6241 ssh2_pkt_adduint32(pktout, c->remoteid);
6242 ssh2_pkt_send(ssh, pktout);
6246 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6249 int typelen, want_reply;
6250 struct Packet *pktout;
6252 ssh_pkt_getstring(pktin, &type, &typelen);
6253 want_reply = ssh2_pkt_getbool(pktin);
6256 * We currently don't support any global requests
6257 * at all, so we either ignore the request or
6258 * respond with REQUEST_FAILURE, depending on
6262 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6263 ssh2_pkt_send(ssh, pktout);
6267 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6275 struct ssh_channel *c;
6276 unsigned remid, winsize, pktsize;
6277 struct Packet *pktout;
6279 ssh_pkt_getstring(pktin, &type, &typelen);
6280 c = snew(struct ssh_channel);
6283 remid = ssh_pkt_getuint32(pktin);
6284 winsize = ssh_pkt_getuint32(pktin);
6285 pktsize = ssh_pkt_getuint32(pktin);
6287 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6290 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6291 addrstr = snewn(peeraddrlen+1, char);
6292 memcpy(addrstr, peeraddr, peeraddrlen);
6293 addrstr[peeraddrlen] = '\0';
6294 peerport = ssh_pkt_getuint32(pktin);
6296 logeventf(ssh, "Received X11 connect request from %s:%d",
6299 if (!ssh->X11_fwd_enabled)
6300 error = "X11 forwarding is not enabled";
6301 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6302 ssh->x11auth, addrstr, peerport,
6303 &ssh->cfg) != NULL) {
6304 error = "Unable to open an X11 connection";
6306 logevent("Opening X11 forward connection succeeded");
6311 } else if (typelen == 15 &&
6312 !memcmp(type, "forwarded-tcpip", 15)) {
6313 struct ssh_rportfwd pf, *realpf;
6316 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6317 pf.sport = ssh_pkt_getuint32(pktin);
6318 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6319 peerport = ssh_pkt_getuint32(pktin);
6320 realpf = find234(ssh->rportfwds, &pf, NULL);
6321 logeventf(ssh, "Received remote port %d open request "
6322 "from %s:%d", pf.sport, peeraddr, peerport);
6323 if (realpf == NULL) {
6324 error = "Remote port is not recognised";
6326 const char *e = pfd_newconnect(&c->u.pfd.s,
6330 realpf->pfrec->addressfamily);
6331 logeventf(ssh, "Attempting to forward remote port to "
6332 "%s:%d", realpf->dhost, realpf->dport);
6334 logeventf(ssh, "Port open failed: %s", e);
6335 error = "Port open failed";
6337 logevent("Forwarded port opened successfully");
6338 c->type = CHAN_SOCKDATA;
6341 } else if (typelen == 22 &&
6342 !memcmp(type, "auth-agent@openssh.com", 3)) {
6343 if (!ssh->agentfwd_enabled)
6344 error = "Agent forwarding is not enabled";
6346 c->type = CHAN_AGENT; /* identify channel type */
6347 c->u.a.lensofar = 0;
6350 error = "Unsupported channel type requested";
6353 c->remoteid = remid;
6354 c->halfopen = FALSE;
6356 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6357 ssh2_pkt_adduint32(pktout, c->remoteid);
6358 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6359 ssh2_pkt_addstring(pktout, error);
6360 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6361 ssh2_pkt_send(ssh, pktout);
6362 logeventf(ssh, "Rejected channel open: %s", error);
6365 c->localid = alloc_channel_id(ssh);
6367 c->v.v2.locwindow = OUR_V2_WINSIZE;
6368 c->v.v2.remwindow = winsize;
6369 c->v.v2.remmaxpkt = pktsize;
6370 bufchain_init(&c->v.v2.outbuffer);
6371 add234(ssh->channels, c);
6372 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6373 ssh2_pkt_adduint32(pktout, c->remoteid);
6374 ssh2_pkt_adduint32(pktout, c->localid);
6375 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6376 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6377 ssh2_pkt_send(ssh, pktout);
6381 /* Helper function to deal with sending tty modes for "pty-req" */
6382 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6384 struct Packet *pktout = (struct Packet *)data;
6386 unsigned int arg = 0;
6387 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6388 if (i == lenof(ssh_ttymodes)) return;
6389 switch (ssh_ttymodes[i].type) {
6391 arg = ssh_tty_parse_specchar(val);
6394 arg = ssh_tty_parse_boolean(val);
6397 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6398 ssh2_pkt_adduint32(pktout, arg);
6402 * Handle the SSH-2 userauth and connection layers.
6404 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6405 struct Packet *pktin)
6407 struct do_ssh2_authconn_state {
6409 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6411 AUTH_KEYBOARD_INTERACTIVE
6415 AUTH_TYPE_PUBLICKEY,
6416 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6417 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6419 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6420 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6422 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6423 int tried_pubkey_config, tried_agent;
6424 int kbd_inter_running, kbd_inter_refused;
6426 int num_prompts, curr_prompt, echo;
6431 void *publickey_blob;
6432 int publickey_bloblen;
6433 unsigned char request[5], *response, *p;
6437 char *pkblob, *alg, *commentp;
6438 int pklen, alglen, commentlen;
6439 int siglen, retlen, len;
6440 char *q, *agentreq, *ret;
6442 int num_env, env_left, env_ok;
6443 struct Packet *pktout;
6445 crState(do_ssh2_authconn_state);
6447 crBegin(ssh->do_ssh2_authconn_crstate);
6450 * Request userauth protocol, and await a response to it.
6452 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6453 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6454 ssh2_pkt_send(ssh, s->pktout);
6455 crWaitUntilV(pktin);
6456 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6457 bombout(("Server refused user authentication protocol"));
6462 * We repeat this whole loop, including the username prompt,
6463 * until we manage a successful authentication. If the user
6464 * types the wrong _password_, they can be sent back to the
6465 * beginning to try another username, if this is configured on.
6466 * (If they specify a username in the config, they are never
6467 * asked, even if they do give a wrong password.)
6469 * I think this best serves the needs of
6471 * - the people who have no configuration, no keys, and just
6472 * want to try repeated (username,password) pairs until they
6473 * type both correctly
6475 * - people who have keys and configuration but occasionally
6476 * need to fall back to passwords
6478 * - people with a key held in Pageant, who might not have
6479 * logged in to a particular machine before; so they want to
6480 * type a username, and then _either_ their key will be
6481 * accepted, _or_ they will type a password. If they mistype
6482 * the username they will want to be able to get back and
6485 s->username[0] = '\0';
6486 s->got_username = FALSE;
6491 if (s->got_username && !ssh->cfg.change_username) {
6493 * We got a username last time round this loop, and
6494 * with change_username turned off we don't try to get
6497 } else if (!*ssh->cfg.username) {
6498 if (ssh_get_line && !ssh_getline_pw_only) {
6499 if (!ssh_get_line("login as: ",
6500 s->username, sizeof(s->username), FALSE)) {
6502 * get_line failed to get a username.
6505 logevent("No username provided. Abandoning session.");
6506 ssh->close_expected = TRUE;
6507 ssh_closing((Plug)ssh, NULL, 0, 0);
6511 int ret; /* need not be saved across crReturn */
6512 c_write_str(ssh, "login as: ");
6514 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6516 crWaitUntilV(!pktin);
6517 ret = process_userpass_input(ssh, in, inlen);
6521 c_write_str(ssh, "\r\n");
6523 s->username[strcspn(s->username, "\n\r")] = '\0';
6526 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6527 s->username[sizeof(s->username)-1] = '\0';
6528 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6529 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6530 c_write_str(ssh, stuff);
6534 s->got_username = TRUE;
6537 * Send an authentication request using method "none": (a)
6538 * just in case it succeeds, and (b) so that we know what
6539 * authentication methods we can usefully try next.
6541 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6543 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6544 ssh2_pkt_addstring(s->pktout, s->username);
6545 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6546 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6547 ssh2_pkt_send(ssh, s->pktout);
6548 s->type = AUTH_TYPE_NONE;
6550 s->we_are_in = FALSE;
6552 s->tried_pubkey_config = FALSE;
6553 s->tried_agent = FALSE;
6554 s->kbd_inter_running = FALSE;
6555 s->kbd_inter_refused = FALSE;
6556 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6557 if (!filename_is_null(ssh->cfg.keyfile)) {
6559 logeventf(ssh, "Reading private key file \"%.150s\"",
6560 filename_to_str(&ssh->cfg.keyfile));
6561 keytype = key_type(&ssh->cfg.keyfile);
6562 if (keytype == SSH_KEYTYPE_SSH2) {
6564 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6565 &s->publickey_bloblen, NULL);
6568 logeventf(ssh, "Unable to use this key file (%s)",
6569 key_type_to_str(keytype));
6570 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6572 filename_to_str(&ssh->cfg.keyfile),
6573 key_type_to_str(keytype));
6574 c_write_str(ssh, msgbuf);
6576 s->publickey_blob = NULL;
6579 s->publickey_blob = NULL;
6583 * Wait for the result of the last authentication request.
6586 crWaitUntilV(pktin);
6587 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6591 * Don't show the banner if we're operating in
6592 * non-verbose non-interactive mode. (It's probably
6593 * a script, which means nobody will read the
6594 * banner _anyway_, and moreover the printing of
6595 * the banner will screw up processing on the
6596 * output of (say) plink.)
6598 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6599 ssh_pkt_getstring(pktin, &banner, &size);
6601 c_write_untrusted(ssh, banner, size);
6603 crWaitUntilV(pktin);
6605 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6606 logevent("Access granted");
6607 s->we_are_in = TRUE;
6611 if (s->kbd_inter_running &&
6612 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6614 * This is either a further set-of-prompts packet
6615 * in keyboard-interactive authentication, or it's
6616 * the same one and we came back here with `gotit'
6617 * set. In the former case, we must reset the
6618 * curr_prompt variable.
6622 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6623 /* FIXME: perhaps we should support this? */
6624 bombout(("PASSWD_CHANGEREQ not yet supported"));
6626 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6627 bombout(("Strange packet received during authentication: type %d",
6635 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6636 * we can look at the string in it and know what we can
6637 * helpfully try next.
6639 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6642 ssh_pkt_getstring(pktin, &methods, &methlen);
6643 s->kbd_inter_running = FALSE;
6644 if (!ssh2_pkt_getbool(pktin)) {
6646 * We have received an unequivocal Access
6647 * Denied. This can translate to a variety of
6650 * - if we'd just tried "none" authentication,
6651 * it's not worth printing anything at all
6653 * - if we'd just tried a public key _offer_,
6654 * the message should be "Server refused our
6655 * key" (or no message at all if the key
6656 * came from Pageant)
6658 * - if we'd just tried anything else, the
6659 * message really should be "Access denied".
6661 * Additionally, if we'd just tried password
6662 * authentication, we should break out of this
6663 * whole loop so as to go back to the username
6664 * prompt (iff we're configured to allow
6665 * username change attempts).
6667 if (s->type == AUTH_TYPE_NONE) {
6669 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6670 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6671 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6672 c_write_str(ssh, "Server refused our key\r\n");
6673 logevent("Server refused public key");
6674 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6675 /* server declined keyboard-interactive; ignore */
6677 c_write_str(ssh, "Access denied\r\n");
6678 logevent("Access denied");
6679 if (s->type == AUTH_TYPE_PASSWORD &&
6680 ssh->cfg.change_username) {
6681 /* XXX perhaps we should allow
6682 * keyboard-interactive to do this too? */
6683 s->we_are_in = FALSE;
6688 c_write_str(ssh, "Further authentication required\r\n");
6689 logevent("Further authentication required");
6693 in_commasep_string("publickey", methods, methlen);
6695 in_commasep_string("password", methods, methlen);
6696 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6697 in_commasep_string("keyboard-interactive", methods, methlen);
6701 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6705 * Most password/passphrase prompts will be
6706 * non-echoing, so we set this to 0 by default.
6707 * Exception is that some keyboard-interactive prompts
6708 * can be echoing, in which case we'll set this to 1.
6712 if (!s->method && s->can_pubkey &&
6713 agent_exists() && !s->tried_agent) {
6715 * Attempt public-key authentication using Pageant.
6720 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6721 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6723 s->tried_agent = TRUE;
6725 logevent("Pageant is running. Requesting keys.");
6727 /* Request the keys held by the agent. */
6728 PUT_32BIT(s->request, 1);
6729 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6730 if (!agent_query(s->request, 5, &r, &s->responselen,
6731 ssh_agent_callback, ssh)) {
6735 bombout(("Unexpected data from server while"
6736 " waiting for agent response"));
6739 } while (pktin || inlen > 0);
6740 r = ssh->agent_response;
6741 s->responselen = ssh->agent_response_len;
6743 s->response = (unsigned char *) r;
6744 if (s->response && s->responselen >= 5 &&
6745 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6746 s->p = s->response + 5;
6747 s->nkeys = GET_32BIT(s->p);
6749 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6750 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6753 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6754 s->pklen = GET_32BIT(s->p);
6756 if (s->publickey_blob &&
6757 s->pklen == s->publickey_bloblen &&
6758 !memcmp(s->p, s->publickey_blob,
6759 s->publickey_bloblen)) {
6760 logevent("This key matches configured key file");
6761 s->tried_pubkey_config = 1;
6763 s->pkblob = (char *)s->p;
6765 s->alglen = GET_32BIT(s->pkblob);
6766 s->alg = s->pkblob + 4;
6767 s->commentlen = GET_32BIT(s->p);
6769 s->commentp = (char *)s->p;
6770 s->p += s->commentlen;
6771 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6772 ssh2_pkt_addstring(s->pktout, s->username);
6773 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6774 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6775 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6776 ssh2_pkt_addstring_start(s->pktout);
6777 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6778 ssh2_pkt_addstring_start(s->pktout);
6779 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6780 ssh2_pkt_send(ssh, s->pktout);
6782 crWaitUntilV(pktin);
6783 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6784 logevent("Key refused");
6788 if (flags & FLAG_VERBOSE) {
6789 c_write_str(ssh, "Authenticating with "
6791 c_write(ssh, s->commentp, s->commentlen);
6792 c_write_str(ssh, "\" from agent\r\n");
6796 * Server is willing to accept the key.
6797 * Construct a SIGN_REQUEST.
6799 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6800 ssh2_pkt_addstring(s->pktout, s->username);
6801 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6802 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6803 ssh2_pkt_addbool(s->pktout, TRUE);
6804 ssh2_pkt_addstring_start(s->pktout);
6805 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6806 ssh2_pkt_addstring_start(s->pktout);
6807 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6809 s->siglen = s->pktout->length - 5 + 4 + 20;
6810 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6812 s->len = 1; /* message type */
6813 s->len += 4 + s->pklen; /* key blob */
6814 s->len += 4 + s->siglen; /* data to sign */
6815 s->len += 4; /* flags */
6816 s->agentreq = snewn(4 + s->len, char);
6817 PUT_32BIT(s->agentreq, s->len);
6818 s->q = s->agentreq + 4;
6819 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6820 PUT_32BIT(s->q, s->pklen);
6822 memcpy(s->q, s->pkblob, s->pklen);
6824 PUT_32BIT(s->q, s->siglen);
6826 /* Now the data to be signed... */
6827 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6828 PUT_32BIT(s->q, 20);
6831 memcpy(s->q, ssh->v2_session_id, 20);
6833 memcpy(s->q, s->pktout->data + 5,
6834 s->pktout->length - 5);
6835 s->q += s->pktout->length - 5;
6836 /* And finally the (zero) flags word. */
6838 if (!agent_query(s->agentreq, s->len + 4,
6840 ssh_agent_callback, ssh)) {
6844 bombout(("Unexpected data from server"
6845 " while waiting for agent"
6849 } while (pktin || inlen > 0);
6850 vret = ssh->agent_response;
6851 s->retlen = ssh->agent_response_len;
6856 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6857 logevent("Sending Pageant's response");
6858 ssh2_add_sigblob(ssh, s->pktout,
6859 s->pkblob, s->pklen,
6861 GET_32BIT(s->ret + 5));
6862 ssh2_pkt_send(ssh, s->pktout);
6867 ("Pageant failed to answer challenge");
6878 if (!s->method && s->can_pubkey && s->publickey_blob
6879 && !s->tried_pubkey_config) {
6880 unsigned char *pub_blob;
6881 char *algorithm, *comment;
6884 s->tried_pubkey_config = TRUE;
6886 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6887 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6890 * Try the public key supplied in the configuration.
6892 * First, offer the public blob to see if the server is
6893 * willing to accept it.
6896 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6901 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6902 ssh2_pkt_addstring(s->pktout, s->username);
6903 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6904 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6905 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6906 ssh2_pkt_addstring(s->pktout, algorithm);
6907 ssh2_pkt_addstring_start(s->pktout);
6908 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6910 ssh2_pkt_send(ssh, s->pktout);
6911 logevent("Offered public key");
6913 crWaitUntilV(pktin);
6914 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6916 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6917 continue; /* key refused; give up on it */
6920 logevent("Offer of public key accepted");
6922 * Actually attempt a serious authentication using
6925 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6926 sprintf(s->pwprompt,
6927 "Passphrase for key \"%.100s\": ",
6933 if (flags & FLAG_VERBOSE) {
6934 c_write_str(ssh, "Authenticating with public key \"");
6935 c_write_str(ssh, comment);
6936 c_write_str(ssh, "\"\r\n");
6938 s->method = AUTH_PUBLICKEY_FILE;
6942 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6943 !s->kbd_inter_running) {
6944 s->method = AUTH_KEYBOARD_INTERACTIVE;
6945 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6947 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6948 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6950 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6951 ssh2_pkt_addstring(s->pktout, s->username);
6952 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6953 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6954 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6955 ssh2_pkt_addstring(s->pktout, "");
6956 ssh2_pkt_send(ssh, s->pktout);
6958 crWaitUntilV(pktin);
6959 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6960 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6962 logevent("Keyboard-interactive authentication refused");
6963 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6964 s->kbd_inter_refused = TRUE; /* don't try it again */
6968 c_write_str(ssh, "Using keyboard-interactive authentication.\r\n");
6969 s->kbd_inter_running = TRUE;
6973 if (s->kbd_inter_running) {
6974 s->method = AUTH_KEYBOARD_INTERACTIVE;
6975 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6977 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6978 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6980 if (s->curr_prompt == 0) {
6982 * We've got a fresh USERAUTH_INFO_REQUEST.
6983 * Display header data, and start going through
6986 char *name, *inst, *lang;
6987 int name_len, inst_len, lang_len;
6989 ssh_pkt_getstring(pktin, &name, &name_len);
6990 ssh_pkt_getstring(pktin, &inst, &inst_len);
6991 ssh_pkt_getstring(pktin, &lang, &lang_len);
6993 c_write_untrusted(ssh, name, name_len);
6994 c_write_str(ssh, "\r\n");
6997 c_write_untrusted(ssh, inst, inst_len);
6998 c_write_str(ssh, "\r\n");
7000 s->num_prompts = ssh_pkt_getuint32(pktin);
7004 * If there are prompts remaining in the packet,
7005 * display one and get a response.
7007 if (s->curr_prompt < s->num_prompts) {
7011 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7012 if (prompt_len > 0) {
7013 static const char trunc[] = "<prompt truncated>: ";
7014 static const int prlen = sizeof(s->pwprompt) -
7016 if (prompt_len > prlen) {
7017 memcpy(s->pwprompt, prompt, prlen);
7018 strcpy(s->pwprompt + prlen, trunc);
7020 memcpy(s->pwprompt, prompt, prompt_len);
7021 s->pwprompt[prompt_len] = '\0';
7025 "<server failed to send prompt>: ");
7027 s->echo = ssh2_pkt_getbool(pktin);
7033 if (!s->method && s->can_passwd) {
7034 s->method = AUTH_PASSWORD;
7035 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7036 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7037 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
7044 if (!ssh_get_line(s->pwprompt, s->password,
7045 sizeof(s->password), TRUE)) {
7047 * get_line failed to get a password (for
7048 * example because one was supplied on the
7049 * command line which has already failed to
7052 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7053 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
7054 ssh2_pkt_addstring(s->pktout, "No more passwords available"
7056 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
7057 ssh2_pkt_send_noqueue(ssh, s->pktout);
7058 logevent("Unable to authenticate");
7059 connection_fatal(ssh->frontend,
7060 "Unable to authenticate");
7061 ssh->close_expected = TRUE;
7062 ssh_closing((Plug)ssh, NULL, 0, 0);
7066 int ret; /* need not be saved across crReturn */
7067 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
7070 setup_userpass_input(ssh, s->password,
7071 sizeof(s->password), s->echo);
7073 crWaitUntilV(!pktin);
7074 ret = process_userpass_input(ssh, in, inlen);
7078 c_write_str(ssh, "\r\n");
7082 if (s->method == AUTH_PUBLICKEY_FILE) {
7084 * We have our passphrase. Now try the actual authentication.
7086 struct ssh2_userkey *key;
7087 const char *error = NULL;
7089 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
7091 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7092 if (key == SSH2_WRONG_PASSPHRASE) {
7093 c_write_str(ssh, "Wrong passphrase\r\n");
7094 s->tried_pubkey_config = FALSE;
7096 c_write_str(ssh, "Unable to load private key (");
7097 c_write_str(ssh, error);
7098 c_write_str(ssh, ")\r\n");
7099 s->tried_pubkey_config = TRUE;
7101 /* Send a spurious AUTH_NONE to return to the top. */
7102 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7103 ssh2_pkt_addstring(s->pktout, s->username);
7104 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7105 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7106 ssh2_pkt_send(ssh, s->pktout);
7107 s->type = AUTH_TYPE_NONE;
7109 unsigned char *pkblob, *sigblob, *sigdata;
7110 int pkblob_len, sigblob_len, sigdata_len;
7114 * We have loaded the private key and the server
7115 * has announced that it's willing to accept it.
7116 * Hallelujah. Generate a signature and send it.
7118 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7119 ssh2_pkt_addstring(s->pktout, s->username);
7120 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7121 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7122 ssh2_pkt_addbool(s->pktout, TRUE);
7123 ssh2_pkt_addstring(s->pktout, key->alg->name);
7124 pkblob = key->alg->public_blob(key->data, &pkblob_len);
7125 ssh2_pkt_addstring_start(s->pktout);
7126 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
7129 * The data to be signed is:
7133 * followed by everything so far placed in the
7136 sigdata_len = s->pktout->length - 5 + 4 + 20;
7137 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7139 sigdata = snewn(sigdata_len, unsigned char);
7141 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7142 PUT_32BIT(sigdata+p, 20);
7145 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
7146 memcpy(sigdata+p, s->pktout->data + 5,
7147 s->pktout->length - 5);
7148 p += s->pktout->length - 5;
7149 assert(p == sigdata_len);
7150 sigblob = key->alg->sign(key->data, (char *)sigdata,
7151 sigdata_len, &sigblob_len);
7152 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7153 sigblob, sigblob_len);
7158 ssh2_pkt_send(ssh, s->pktout);
7159 s->type = AUTH_TYPE_PUBLICKEY;
7160 key->alg->freekey(key->data);
7162 } else if (s->method == AUTH_PASSWORD) {
7164 * We pad out the password packet to 256 bytes to make
7165 * it harder for an attacker to find the length of the
7168 * Anyone using a password longer than 256 bytes
7169 * probably doesn't have much to worry about from
7170 * people who find out how long their password is!
7172 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7173 s->pktout->forcepad = 256;
7174 ssh2_pkt_addstring(s->pktout, s->username);
7175 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7176 ssh2_pkt_addstring(s->pktout, "password");
7177 ssh2_pkt_addbool(s->pktout, FALSE);
7178 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7179 ssh2_pkt_addstring(s->pktout, s->password);
7180 memset(s->password, 0, sizeof(s->password));
7181 end_log_omission(ssh, s->pktout);
7182 ssh2_pkt_send(ssh, s->pktout);
7183 logevent("Sent password");
7184 s->type = AUTH_TYPE_PASSWORD;
7185 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7186 if (s->curr_prompt == 0) {
7187 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7188 s->pktout->forcepad = 256;
7189 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7191 if (s->need_pw) { /* only add pw if we just got one! */
7192 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7193 ssh2_pkt_addstring(s->pktout, s->password);
7194 memset(s->password, 0, sizeof(s->password));
7195 end_log_omission(ssh, s->pktout);
7198 if (s->curr_prompt >= s->num_prompts) {
7199 ssh2_pkt_send(ssh, s->pktout);
7202 * If there are prompts remaining, we set
7203 * `gotit' so that we won't attempt to get
7204 * another packet. Then we go back round the
7205 * loop and will end up retrieving another
7206 * prompt out of the existing packet. Funky or
7211 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7213 c_write_str(ssh, "No supported authentication methods"
7214 " left to try!\r\n");
7215 logevent("No supported authentications offered."
7217 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
7218 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
7219 ssh2_pkt_addstring(s->pktout, "No supported authentication"
7220 " methods available");
7221 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
7222 ssh2_pkt_send_noqueue(ssh, s->pktout);
7223 ssh->close_expected = TRUE;
7224 ssh_closing((Plug)ssh, NULL, 0, 0);
7228 } while (!s->we_are_in);
7231 * Now we're authenticated for the connection protocol. The
7232 * connection protocol will automatically have started at this
7233 * point; there's no need to send SERVICE_REQUEST.
7236 ssh->channels = newtree234(ssh_channelcmp);
7239 * Set up handlers for some connection protocol messages, so we
7240 * don't have to handle them repeatedly in this coroutine.
7242 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7243 ssh2_msg_channel_window_adjust;
7244 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7245 ssh2_msg_global_request;
7248 * Create the main session channel.
7250 if (!ssh->cfg.ssh_no_shell) {
7251 ssh->mainchan = snew(struct ssh_channel);
7252 ssh->mainchan->ssh = ssh;
7253 ssh->mainchan->localid = alloc_channel_id(ssh);
7254 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7255 ssh2_pkt_addstring(s->pktout, "session");
7256 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7257 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7258 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7259 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7260 ssh2_pkt_send(ssh, s->pktout);
7261 crWaitUntilV(pktin);
7262 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7263 bombout(("Server refused to open a session"));
7265 /* FIXME: error data comes back in FAILURE packet */
7267 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7268 bombout(("Server's channel confirmation cited wrong channel"));
7271 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7272 ssh->mainchan->halfopen = FALSE;
7273 ssh->mainchan->type = CHAN_MAINSESSION;
7274 ssh->mainchan->closes = 0;
7275 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7276 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7277 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7278 add234(ssh->channels, ssh->mainchan);
7279 update_specials_menu(ssh->frontend);
7280 logevent("Opened channel for session");
7282 ssh->mainchan = NULL;
7285 * Now we have a channel, make dispatch table entries for
7286 * general channel-based messages.
7288 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7289 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7290 ssh2_msg_channel_data;
7291 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7292 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7293 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7294 ssh2_msg_channel_open_confirmation;
7295 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7296 ssh2_msg_channel_open_failure;
7297 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7298 ssh2_msg_channel_request;
7299 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7300 ssh2_msg_channel_open;
7303 * Potentially enable X11 forwarding.
7305 if (ssh->mainchan && ssh->cfg.x11_forward) {
7306 char proto[20], data[64];
7307 logevent("Requesting X11 forwarding");
7308 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7309 data, sizeof(data), ssh->cfg.x11_auth);
7310 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7311 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7312 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7313 ssh2_pkt_addstring(s->pktout, "x11-req");
7314 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7315 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7316 ssh2_pkt_addstring(s->pktout, proto);
7317 ssh2_pkt_addstring(s->pktout, data);
7318 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7319 ssh2_pkt_send(ssh, s->pktout);
7321 crWaitUntilV(pktin);
7323 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7324 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7325 bombout(("Unexpected response to X11 forwarding request:"
7326 " packet type %d", pktin->type));
7329 logevent("X11 forwarding refused");
7331 logevent("X11 forwarding enabled");
7332 ssh->X11_fwd_enabled = TRUE;
7337 * Enable port forwardings.
7339 ssh_setup_portfwd(ssh, &ssh->cfg);
7342 * Potentially enable agent forwarding.
7344 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7345 logevent("Requesting OpenSSH-style agent forwarding");
7346 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7347 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7348 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7349 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7350 ssh2_pkt_send(ssh, s->pktout);
7352 crWaitUntilV(pktin);
7354 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7355 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7356 bombout(("Unexpected response to agent forwarding request:"
7357 " packet type %d", pktin->type));
7360 logevent("Agent forwarding refused");
7362 logevent("Agent forwarding enabled");
7363 ssh->agentfwd_enabled = TRUE;
7368 * Now allocate a pty for the session.
7370 if (ssh->mainchan && !ssh->cfg.nopty) {
7371 /* Unpick the terminal-speed string. */
7372 /* XXX perhaps we should allow no speeds to be sent. */
7373 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7374 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7375 /* Build the pty request. */
7376 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7377 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7378 ssh2_pkt_addstring(s->pktout, "pty-req");
7379 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7380 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7381 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7382 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7383 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7384 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7385 ssh2_pkt_addstring_start(s->pktout);
7386 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7387 ssh2_send_ttymode, (void *)s->pktout);
7388 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
7389 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7390 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
7391 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7392 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7393 ssh2_pkt_send(ssh, s->pktout);
7394 ssh->state = SSH_STATE_INTERMED;
7396 crWaitUntilV(pktin);
7398 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7399 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7400 bombout(("Unexpected response to pty request:"
7401 " packet type %d", pktin->type));
7404 c_write_str(ssh, "Server refused to allocate pty\r\n");
7405 ssh->editing = ssh->echoing = 1;
7407 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7408 ssh->ospeed, ssh->ispeed);
7411 ssh->editing = ssh->echoing = 1;
7415 * Send environment variables.
7417 * Simplest thing here is to send all the requests at once, and
7418 * then wait for a whole bunch of successes or failures.
7420 if (ssh->mainchan && *ssh->cfg.environmt) {
7421 char *e = ssh->cfg.environmt;
7422 char *var, *varend, *val;
7428 while (*e && *e != '\t') e++;
7430 if (*e == '\t') e++;
7435 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7436 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7437 ssh2_pkt_addstring(s->pktout, "env");
7438 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7439 ssh2_pkt_addstring_start(s->pktout);
7440 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7441 ssh2_pkt_addstring(s->pktout, val);
7442 ssh2_pkt_send(ssh, s->pktout);
7447 logeventf(ssh, "Sent %d environment variables", s->num_env);
7450 s->env_left = s->num_env;
7452 while (s->env_left > 0) {
7453 crWaitUntilV(pktin);
7455 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7456 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7457 bombout(("Unexpected response to environment request:"
7458 " packet type %d", pktin->type));
7468 if (s->env_ok == s->num_env) {
7469 logevent("All environment variables successfully set");
7470 } else if (s->env_ok == 0) {
7471 logevent("All environment variables refused");
7472 c_write_str(ssh, "Server refused to set environment variables\r\n");
7474 logeventf(ssh, "%d environment variables refused",
7475 s->num_env - s->env_ok);
7476 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7481 * Start a shell or a remote command. We may have to attempt
7482 * this twice if the config data has provided a second choice
7485 if (ssh->mainchan) while (1) {
7489 if (ssh->fallback_cmd) {
7490 subsys = ssh->cfg.ssh_subsys2;
7491 cmd = ssh->cfg.remote_cmd_ptr2;
7493 subsys = ssh->cfg.ssh_subsys;
7494 cmd = ssh->cfg.remote_cmd_ptr;
7495 if (!cmd) cmd = ssh->cfg.remote_cmd;
7498 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7499 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7501 ssh2_pkt_addstring(s->pktout, "subsystem");
7502 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7503 ssh2_pkt_addstring(s->pktout, cmd);
7505 ssh2_pkt_addstring(s->pktout, "exec");
7506 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7507 ssh2_pkt_addstring(s->pktout, cmd);
7509 ssh2_pkt_addstring(s->pktout, "shell");
7510 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7512 ssh2_pkt_send(ssh, s->pktout);
7514 crWaitUntilV(pktin);
7516 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7517 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7518 bombout(("Unexpected response to shell/command request:"
7519 " packet type %d", pktin->type));
7523 * We failed to start the command. If this is the
7524 * fallback command, we really are finished; if it's
7525 * not, and if the fallback command exists, try falling
7526 * back to it before complaining.
7528 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7529 logevent("Primary command failed; attempting fallback");
7530 ssh->fallback_cmd = TRUE;
7533 bombout(("Server refused to start a shell/command"));
7536 logevent("Started a shell/command");
7541 ssh->state = SSH_STATE_SESSION;
7542 if (ssh->size_needed)
7543 ssh_size(ssh, ssh->term_width, ssh->term_height);
7544 if (ssh->eof_needed)
7545 ssh_special(ssh, TS_EOF);
7551 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7556 s->try_send = FALSE;
7560 * _All_ the connection-layer packets we expect to
7561 * receive are now handled by the dispatch table.
7562 * Anything that reaches here must be bogus.
7565 bombout(("Strange packet received: type %d", pktin->type));
7567 } else if (ssh->mainchan) {
7569 * We have spare data. Add it to the channel buffer.
7571 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7576 struct ssh_channel *c;
7578 * Try to send data on all channels if we can.
7580 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7581 ssh2_try_send_and_unthrottle(c);
7589 * Handlers for SSH-2 messages that might arrive at any moment.
7591 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7593 /* log reason code in disconnect message */
7595 int nowlen, reason, msglen;
7597 reason = ssh_pkt_getuint32(pktin);
7598 ssh_pkt_getstring(pktin, &msg, &msglen);
7600 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7601 buf = dupprintf("Received disconnect message (%s)",
7602 ssh2_disconnect_reasons[reason]);
7604 buf = dupprintf("Received disconnect message (unknown"
7605 " type %d)", reason);
7609 buf = dupprintf("Disconnection message text: %n%.*s",
7610 &nowlen, msglen, msg);
7612 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7614 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7615 ssh2_disconnect_reasons[reason] : "unknown",
7620 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7622 /* log the debug message */
7627 /* XXX maybe we should actually take notice of this */
7628 always_display = ssh2_pkt_getbool(pktin);
7629 ssh_pkt_getstring(pktin, &msg, &msglen);
7631 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7634 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7636 struct Packet *pktout;
7637 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7638 ssh2_pkt_adduint32(pktout, pktin->sequence);
7640 * UNIMPLEMENTED messages MUST appear in the same order as the
7641 * messages they respond to. Hence, never queue them.
7643 ssh2_pkt_send_noqueue(ssh, pktout);
7647 * Handle the top-level SSH-2 protocol.
7649 static void ssh2_protocol_setup(Ssh ssh)
7654 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7656 for (i = 0; i < 256; i++)
7657 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7660 * Any message we actually understand, we set to NULL so that
7661 * the coroutines will get it.
7663 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7664 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7665 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7666 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7667 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7668 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7669 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7670 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7671 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7672 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7673 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7674 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7675 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7676 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7677 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7678 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7679 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7680 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7681 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7682 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7683 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7684 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7685 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7686 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7687 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7688 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7689 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7690 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7691 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7692 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7693 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7694 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7695 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7698 * These special message types we install handlers for.
7700 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7701 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
7702 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7705 static void ssh2_timer(void *ctx, long now)
7709 if (ssh->state == SSH_STATE_CLOSED)
7712 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7713 now - ssh->next_rekey >= 0) {
7714 do_ssh2_transport(ssh, "timeout", -1, NULL);
7718 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7719 struct Packet *pktin)
7721 unsigned char *in = (unsigned char *)vin;
7722 if (ssh->state == SSH_STATE_CLOSED)
7726 ssh->incoming_data_size += pktin->encrypted_len;
7727 if (!ssh->kex_in_progress &&
7728 ssh->max_data_size != 0 &&
7729 ssh->incoming_data_size > ssh->max_data_size)
7730 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7733 if (pktin && ssh->packet_dispatch[pktin->type]) {
7734 ssh->packet_dispatch[pktin->type](ssh, pktin);
7738 if (!ssh->protocol_initial_phase_done ||
7739 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7740 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7741 !ssh->protocol_initial_phase_done) {
7742 ssh->protocol_initial_phase_done = TRUE;
7744 * Allow authconn to initialise itself.
7746 do_ssh2_authconn(ssh, NULL, 0, NULL);
7749 do_ssh2_authconn(ssh, in, inlen, pktin);
7754 * Called to set up the connection.
7756 * Returns an error message, or NULL on success.
7758 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7760 char *host, int port, char **realhost, int nodelay,
7766 ssh = snew(struct ssh_tag);
7767 ssh->cfg = *cfg; /* STRUCTURE COPY */
7768 ssh->version = 0; /* when not ready yet */
7771 ssh->v1_cipher_ctx = NULL;
7772 ssh->crcda_ctx = NULL;
7773 ssh->cscipher = NULL;
7774 ssh->cs_cipher_ctx = NULL;
7775 ssh->sccipher = NULL;
7776 ssh->sc_cipher_ctx = NULL;
7778 ssh->cs_mac_ctx = NULL;
7780 ssh->sc_mac_ctx = NULL;
7782 ssh->cs_comp_ctx = NULL;
7784 ssh->sc_comp_ctx = NULL;
7786 ssh->kex_ctx = NULL;
7787 ssh->hostkey = NULL;
7789 ssh->close_expected = FALSE;
7790 ssh->state = SSH_STATE_PREPACKET;
7791 ssh->size_needed = FALSE;
7792 ssh->eof_needed = FALSE;
7795 ssh->deferred_send_data = NULL;
7796 ssh->deferred_len = 0;
7797 ssh->deferred_size = 0;
7798 ssh->fallback_cmd = 0;
7800 ssh->x11auth = NULL;
7801 ssh->v1_compressing = FALSE;
7802 ssh->v2_outgoing_sequence = 0;
7803 ssh->ssh1_rdpkt_crstate = 0;
7804 ssh->ssh2_rdpkt_crstate = 0;
7805 ssh->do_ssh_init_crstate = 0;
7806 ssh->ssh_gotdata_crstate = 0;
7807 ssh->do_ssh1_connection_crstate = 0;
7808 ssh->do_ssh1_login_crstate = 0;
7809 ssh->do_ssh2_transport_crstate = 0;
7810 ssh->do_ssh2_authconn_crstate = 0;
7811 ssh->do_ssh_init_state = NULL;
7812 ssh->do_ssh1_login_state = NULL;
7813 ssh->do_ssh2_transport_state = NULL;
7814 ssh->do_ssh2_authconn_state = NULL;
7815 ssh->mainchan = NULL;
7816 ssh->throttled_all = 0;
7817 ssh->v1_stdout_throttling = 0;
7819 ssh->queuelen = ssh->queuesize = 0;
7820 ssh->queueing = FALSE;
7821 ssh->qhead = ssh->qtail = NULL;
7822 ssh->deferred_rekey_reason = NULL;
7823 bufchain_init(&ssh->queued_incoming_data);
7824 ssh->frozen = FALSE;
7826 *backend_handle = ssh;
7829 if (crypto_startup() == 0)
7830 return "Microsoft high encryption pack not installed!";
7833 ssh->frontend = frontend_handle;
7834 ssh->term_width = ssh->cfg.width;
7835 ssh->term_height = ssh->cfg.height;
7837 ssh->channels = NULL;
7838 ssh->rportfwds = NULL;
7839 ssh->portfwds = NULL;
7844 ssh->v1_throttle_count = 0;
7845 ssh->overall_bufsize = 0;
7846 ssh->fallback_cmd = 0;
7848 ssh->protocol = NULL;
7850 ssh->protocol_initial_phase_done = FALSE;
7854 ssh->incoming_data_size = ssh->outgoing_data_size =
7855 ssh->deferred_data_size = 0L;
7856 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7857 ssh->kex_in_progress = FALSE;
7859 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7868 static void ssh_free(void *handle)
7870 Ssh ssh = (Ssh) handle;
7871 struct ssh_channel *c;
7872 struct ssh_rportfwd *pf;
7874 if (ssh->v1_cipher_ctx)
7875 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7876 if (ssh->cs_cipher_ctx)
7877 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7878 if (ssh->sc_cipher_ctx)
7879 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7880 if (ssh->cs_mac_ctx)
7881 ssh->csmac->free_context(ssh->cs_mac_ctx);
7882 if (ssh->sc_mac_ctx)
7883 ssh->scmac->free_context(ssh->sc_mac_ctx);
7884 if (ssh->cs_comp_ctx) {
7886 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7888 zlib_compress_cleanup(ssh->cs_comp_ctx);
7890 if (ssh->sc_comp_ctx) {
7892 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7894 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7897 dh_cleanup(ssh->kex_ctx);
7898 sfree(ssh->savedhost);
7900 while (ssh->queuelen-- > 0)
7901 ssh_free_packet(ssh->queue[ssh->queuelen]);
7904 while (ssh->qhead) {
7905 struct queued_handler *qh = ssh->qhead;
7906 ssh->qhead = qh->next;
7909 ssh->qhead = ssh->qtail = NULL;
7911 if (ssh->channels) {
7912 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7915 if (c->u.x11.s != NULL)
7916 x11_close(c->u.x11.s);
7919 if (c->u.pfd.s != NULL)
7920 pfd_close(c->u.pfd.s);
7925 freetree234(ssh->channels);
7926 ssh->channels = NULL;
7929 if (ssh->rportfwds) {
7930 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7932 freetree234(ssh->rportfwds);
7933 ssh->rportfwds = NULL;
7935 sfree(ssh->deferred_send_data);
7937 x11_free_auth(ssh->x11auth);
7938 sfree(ssh->do_ssh_init_state);
7939 sfree(ssh->do_ssh1_login_state);
7940 sfree(ssh->do_ssh2_transport_state);
7941 sfree(ssh->do_ssh2_authconn_state);
7942 if (ssh->crcda_ctx) {
7943 crcda_free_context(ssh->crcda_ctx);
7944 ssh->crcda_ctx = NULL;
7947 ssh_do_close(ssh, TRUE);
7948 expire_timer_context(ssh);
7950 pinger_free(ssh->pinger);
7951 bufchain_clear(&ssh->queued_incoming_data);
7958 * Reconfigure the SSH backend.
7960 static void ssh_reconfig(void *handle, Config *cfg)
7962 Ssh ssh = (Ssh) handle;
7963 char *rekeying = NULL, rekey_mandatory = FALSE;
7964 unsigned long old_max_data_size;
7966 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7967 ssh_setup_portfwd(ssh, cfg);
7969 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7970 cfg->ssh_rekey_time != 0) {
7971 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7972 long now = GETTICKCOUNT();
7974 if (new_next - now < 0) {
7975 rekeying = "timeout shortened";
7977 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7981 old_max_data_size = ssh->max_data_size;
7982 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7983 if (old_max_data_size != ssh->max_data_size &&
7984 ssh->max_data_size != 0) {
7985 if (ssh->outgoing_data_size > ssh->max_data_size ||
7986 ssh->incoming_data_size > ssh->max_data_size)
7987 rekeying = "data limit lowered";
7990 if (ssh->cfg.compression != cfg->compression) {
7991 rekeying = "compression setting changed";
7992 rekey_mandatory = TRUE;
7995 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7996 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7997 sizeof(ssh->cfg.ssh_cipherlist))) {
7998 rekeying = "cipher settings changed";
7999 rekey_mandatory = TRUE;
8002 ssh->cfg = *cfg; /* STRUCTURE COPY */
8005 if (!ssh->kex_in_progress) {
8006 do_ssh2_transport(ssh, rekeying, -1, NULL);
8007 } else if (rekey_mandatory) {
8008 ssh->deferred_rekey_reason = rekeying;
8014 * Called to send data down the Telnet connection.
8016 static int ssh_send(void *handle, char *buf, int len)
8018 Ssh ssh = (Ssh) handle;
8020 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8023 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8025 return ssh_sendbuffer(ssh);
8029 * Called to query the current amount of buffered stdin data.
8031 static int ssh_sendbuffer(void *handle)
8033 Ssh ssh = (Ssh) handle;
8036 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8040 * If the SSH socket itself has backed up, add the total backup
8041 * size on that to any individual buffer on the stdin channel.
8044 if (ssh->throttled_all)
8045 override_value = ssh->overall_bufsize;
8047 if (ssh->version == 1) {
8048 return override_value;
8049 } else if (ssh->version == 2) {
8050 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8051 return override_value;
8053 return (override_value +
8054 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8061 * Called to set the size of the window from SSH's POV.
8063 static void ssh_size(void *handle, int width, int height)
8065 Ssh ssh = (Ssh) handle;
8066 struct Packet *pktout;
8068 ssh->term_width = width;
8069 ssh->term_height = height;
8071 switch (ssh->state) {
8072 case SSH_STATE_BEFORE_SIZE:
8073 case SSH_STATE_PREPACKET:
8074 case SSH_STATE_CLOSED:
8075 break; /* do nothing */
8076 case SSH_STATE_INTERMED:
8077 ssh->size_needed = TRUE; /* buffer for later */
8079 case SSH_STATE_SESSION:
8080 if (!ssh->cfg.nopty) {
8081 if (ssh->version == 1) {
8082 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8083 PKT_INT, ssh->term_height,
8084 PKT_INT, ssh->term_width,
8085 PKT_INT, 0, PKT_INT, 0, PKT_END);
8086 } else if (ssh->mainchan) {
8087 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8088 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8089 ssh2_pkt_addstring(pktout, "window-change");
8090 ssh2_pkt_addbool(pktout, 0);
8091 ssh2_pkt_adduint32(pktout, ssh->term_width);
8092 ssh2_pkt_adduint32(pktout, ssh->term_height);
8093 ssh2_pkt_adduint32(pktout, 0);
8094 ssh2_pkt_adduint32(pktout, 0);
8095 ssh2_pkt_send(ssh, pktout);
8103 * Return a list of the special codes that make sense in this
8106 static const struct telnet_special *ssh_get_specials(void *handle)
8108 static const struct telnet_special ssh1_ignore_special[] = {
8109 {"IGNORE message", TS_NOP}
8111 static const struct telnet_special ssh2_transport_specials[] = {
8112 {"IGNORE message", TS_NOP},
8113 {"Repeat key exchange", TS_REKEY},
8115 static const struct telnet_special ssh2_session_specials[] = {
8118 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8119 * They include all the ISO C signals, but are a subset of the POSIX
8120 * required signals. */
8121 {"SIGINT (Interrupt)", TS_SIGINT},
8122 {"SIGTERM (Terminate)", TS_SIGTERM},
8123 {"SIGKILL (Kill)", TS_SIGKILL},
8124 {"SIGQUIT (Quit)", TS_SIGQUIT},
8125 {"SIGHUP (Hangup)", TS_SIGHUP},
8126 {"More signals", TS_SUBMENU},
8127 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8128 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8129 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8130 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8133 static const struct telnet_special specials_end[] = {
8136 /* XXX review this length for any changes: */
8137 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8138 lenof(ssh2_session_specials) +
8139 lenof(specials_end)];
8140 Ssh ssh = (Ssh) handle;
8142 #define ADD_SPECIALS(name) \
8144 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8145 memcpy(&ssh_specials[i], name, sizeof name); \
8149 if (ssh->version == 1) {
8150 /* Don't bother offering IGNORE if we've decided the remote
8151 * won't cope with it, since we wouldn't bother sending it if
8153 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8154 ADD_SPECIALS(ssh1_ignore_special);
8155 } else if (ssh->version == 2) {
8156 ADD_SPECIALS(ssh2_transport_specials);
8158 ADD_SPECIALS(ssh2_session_specials);
8159 } /* else we're not ready yet */
8162 ADD_SPECIALS(specials_end);
8163 return ssh_specials;
8171 * Send Telnet special codes. TS_EOF is useful for `plink', so you
8172 * can send an EOF and collect resulting output (e.g. `plink
8175 static void ssh_special(void *handle, Telnet_Special code)
8177 Ssh ssh = (Ssh) handle;
8178 struct Packet *pktout;
8180 if (code == TS_EOF) {
8181 if (ssh->state != SSH_STATE_SESSION) {
8183 * Buffer the EOF in case we are pre-SESSION, so we can
8184 * send it as soon as we reach SESSION.
8187 ssh->eof_needed = TRUE;
8190 if (ssh->version == 1) {
8191 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8192 } else if (ssh->mainchan) {
8193 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8194 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8195 ssh2_pkt_send(ssh, pktout);
8196 ssh->send_ok = 0; /* now stop trying to read from stdin */
8198 logevent("Sent EOF message");
8199 } else if (code == TS_PING || code == TS_NOP) {
8200 if (ssh->state == SSH_STATE_CLOSED
8201 || ssh->state == SSH_STATE_PREPACKET) return;
8202 if (ssh->version == 1) {
8203 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8204 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8206 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8207 ssh2_pkt_addstring_start(pktout);
8208 ssh2_pkt_send_noqueue(ssh, pktout);
8210 } else if (code == TS_REKEY) {
8211 if (!ssh->kex_in_progress && ssh->version == 2) {
8212 do_ssh2_transport(ssh, "at user request", -1, NULL);
8214 } else if (code == TS_BRK) {
8215 if (ssh->state == SSH_STATE_CLOSED
8216 || ssh->state == SSH_STATE_PREPACKET) return;
8217 if (ssh->version == 1) {
8218 logevent("Unable to send BREAK signal in SSH-1");
8219 } else if (ssh->mainchan) {
8220 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8221 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8222 ssh2_pkt_addstring(pktout, "break");
8223 ssh2_pkt_addbool(pktout, 0);
8224 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8225 ssh2_pkt_send(ssh, pktout);
8228 /* Is is a POSIX signal? */
8229 char *signame = NULL;
8230 if (code == TS_SIGABRT) signame = "ABRT";
8231 if (code == TS_SIGALRM) signame = "ALRM";
8232 if (code == TS_SIGFPE) signame = "FPE";
8233 if (code == TS_SIGHUP) signame = "HUP";
8234 if (code == TS_SIGILL) signame = "ILL";
8235 if (code == TS_SIGINT) signame = "INT";
8236 if (code == TS_SIGKILL) signame = "KILL";
8237 if (code == TS_SIGPIPE) signame = "PIPE";
8238 if (code == TS_SIGQUIT) signame = "QUIT";
8239 if (code == TS_SIGSEGV) signame = "SEGV";
8240 if (code == TS_SIGTERM) signame = "TERM";
8241 if (code == TS_SIGUSR1) signame = "USR1";
8242 if (code == TS_SIGUSR2) signame = "USR2";
8243 /* The SSH-2 protocol does in principle support arbitrary named
8244 * signals, including signame@domain, but we don't support those. */
8246 /* It's a signal. */
8247 if (ssh->version == 2 && ssh->mainchan) {
8248 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8249 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8250 ssh2_pkt_addstring(pktout, "signal");
8251 ssh2_pkt_addbool(pktout, 0);
8252 ssh2_pkt_addstring(pktout, signame);
8253 ssh2_pkt_send(ssh, pktout);
8254 logeventf(ssh, "Sent signal SIG%s", signame);
8257 /* Never heard of it. Do nothing */
8262 void *new_sock_channel(void *handle, Socket s)
8264 Ssh ssh = (Ssh) handle;
8265 struct ssh_channel *c;
8266 c = snew(struct ssh_channel);
8271 c->localid = alloc_channel_id(ssh);
8273 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8275 bufchain_init(&c->v.v2.outbuffer);
8276 add234(ssh->channels, c);
8282 * This is called when stdout/stderr (the entity to which
8283 * from_backend sends data) manages to clear some backlog.
8285 static void ssh_unthrottle(void *handle, int bufsize)
8287 Ssh ssh = (Ssh) handle;
8288 if (ssh->version == 1) {
8289 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8290 ssh->v1_stdout_throttling = 0;
8291 ssh1_throttle(ssh, -1);
8294 if (ssh->mainchan && ssh->mainchan->closes == 0)
8295 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8299 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8301 struct ssh_channel *c = (struct ssh_channel *)channel;
8303 struct Packet *pktout;
8305 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8307 if (ssh->version == 1) {
8308 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8309 PKT_INT, c->localid,
8312 /* PKT_STR, <org:orgport>, */
8315 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8316 ssh2_pkt_addstring(pktout, "direct-tcpip");
8317 ssh2_pkt_adduint32(pktout, c->localid);
8318 c->v.v2.locwindow = OUR_V2_WINSIZE;
8319 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8320 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8321 ssh2_pkt_addstring(pktout, hostname);
8322 ssh2_pkt_adduint32(pktout, port);
8324 * We make up values for the originator data; partly it's
8325 * too much hassle to keep track, and partly I'm not
8326 * convinced the server should be told details like that
8327 * about my local network configuration.
8329 ssh2_pkt_addstring(pktout, "client-side-connection");
8330 ssh2_pkt_adduint32(pktout, 0);
8331 ssh2_pkt_send(ssh, pktout);
8335 static Socket ssh_socket(void *handle)
8337 Ssh ssh = (Ssh) handle;
8341 static int ssh_sendok(void *handle)
8343 Ssh ssh = (Ssh) handle;
8344 return ssh->send_ok;
8347 static int ssh_ldisc(void *handle, int option)
8349 Ssh ssh = (Ssh) handle;
8350 if (option == LD_ECHO)
8351 return ssh->echoing;
8352 if (option == LD_EDIT)
8353 return ssh->editing;
8357 static void ssh_provide_ldisc(void *handle, void *ldisc)
8359 Ssh ssh = (Ssh) handle;
8363 static void ssh_provide_logctx(void *handle, void *logctx)
8365 Ssh ssh = (Ssh) handle;
8366 ssh->logctx = logctx;
8369 static int ssh_return_exitcode(void *handle)
8371 Ssh ssh = (Ssh) handle;
8375 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8379 * cfg_info for SSH is the currently running version of the
8380 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8382 static int ssh_cfg_info(void *handle)
8384 Ssh ssh = (Ssh) handle;
8385 return ssh->version;
8389 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8390 * that fails. This variable is the means by which scp.c can reach
8391 * into the SSH code and find out which one it got.
8393 extern int ssh_fallback_cmd(void *handle)
8395 Ssh ssh = (Ssh) handle;
8396 return ssh->fallback_cmd;
8399 Backend ssh_backend = {
8409 ssh_return_exitcode,