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[] = {
465 &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5
467 const static struct ssh_mac *buggymacs[] = {
468 &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_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 */
690 unsigned char session_key[32];
692 int v1_remote_protoflags;
693 int v1_local_protoflags;
694 int agentfwd_enabled;
697 const struct ssh_cipher *cipher;
700 const struct ssh2_cipher *cscipher, *sccipher;
701 void *cs_cipher_ctx, *sc_cipher_ctx;
702 const struct ssh_mac *csmac, *scmac;
703 void *cs_mac_ctx, *sc_mac_ctx;
704 const struct ssh_compress *cscomp, *sccomp;
705 void *cs_comp_ctx, *sc_comp_ctx;
706 const struct ssh_kex *kex;
707 const struct ssh_signkey *hostkey;
708 unsigned char v2_session_id[32];
709 int v2_session_id_len;
715 int echoing, editing;
719 int ospeed, ispeed; /* temporaries */
720 int term_width, term_height;
722 tree234 *channels; /* indexed by local id */
723 struct ssh_channel *mainchan; /* primary session channel */
728 tree234 *rportfwds, *portfwds;
732 SSH_STATE_BEFORE_SIZE,
738 int size_needed, eof_needed;
740 struct Packet **queue;
741 int queuelen, queuesize;
743 unsigned char *deferred_send_data;
744 int deferred_len, deferred_size;
747 * Gross hack: pscp will try to start SFTP but fall back to
748 * scp1 if that fails. This variable is the means by which
749 * scp.c can reach into the SSH code and find out which one it
754 bufchain banner; /* accumulates banners during do_ssh2_authconn */
756 * Used for username and password input.
758 char *userpass_input_buffer;
759 int userpass_input_buflen;
760 int userpass_input_bufpos;
761 int userpass_input_echo;
768 int v1_throttle_count;
771 int v1_stdout_throttling;
772 unsigned long v2_outgoing_sequence;
774 int ssh1_rdpkt_crstate;
775 int ssh2_rdpkt_crstate;
776 int do_ssh_init_crstate;
777 int ssh_gotdata_crstate;
778 int do_ssh1_login_crstate;
779 int do_ssh1_connection_crstate;
780 int do_ssh2_transport_crstate;
781 int do_ssh2_authconn_crstate;
783 void *do_ssh_init_state;
784 void *do_ssh1_login_state;
785 void *do_ssh2_transport_state;
786 void *do_ssh2_authconn_state;
788 struct rdpkt1_state_tag rdpkt1_state;
789 struct rdpkt2_state_tag rdpkt2_state;
791 /* SSH-1 and SSH-2 use this for different things, but both use it */
792 int protocol_initial_phase_done;
794 void (*protocol) (Ssh ssh, void *vin, int inlen,
796 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
799 * We maintain a full _copy_ of a Config structure here, not
800 * merely a pointer to it. That way, when we're passed a new
801 * one for reconfiguration, we can check the differences and
802 * potentially reconfigure port forwardings etc in mid-session.
807 * Used to transfer data back from async callbacks.
809 void *agent_response;
810 int agent_response_len;
814 * The SSH connection can be set as `frozen', meaning we are
815 * not currently accepting incoming data from the network. This
816 * is slightly more serious than setting the _socket_ as
817 * frozen, because we may already have had data passed to us
818 * from the network which we need to delay processing until
819 * after the freeze is lifted, so we also need a bufchain to
823 bufchain queued_incoming_data;
826 * Dispatch table for packet types that we may have to deal
829 handler_fn_t packet_dispatch[256];
832 * Queues of one-off handler functions for success/failure
833 * indications from a request.
835 struct queued_handler *qhead, *qtail;
838 * This module deals with sending keepalives.
843 * Track incoming and outgoing data sizes and time, for
846 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
847 unsigned long max_data_size;
849 long next_rekey, last_rekey;
850 char *deferred_rekey_reason; /* points to STATIC string; don't free */
853 #define logevent(s) logevent(ssh->frontend, s)
855 /* logevent, only printf-formatted. */
856 static void logeventf(Ssh ssh, const char *fmt, ...)
862 buf = dupvprintf(fmt, ap);
868 #define bombout(msg) \
870 char *text = dupprintf msg; \
871 ssh_do_close(ssh, FALSE); \
873 connection_fatal(ssh->frontend, "%s", text); \
877 /* Functions to leave bits out of the SSH packet log file. */
879 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
881 if (ssh->cfg.logomitpass)
882 pkt->logmode = blanktype;
885 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
887 if (ssh->cfg.logomitdata)
888 pkt->logmode = blanktype;
891 static void end_log_omission(Ssh ssh, struct Packet *pkt)
893 pkt->logmode = PKTLOG_EMIT;
896 /* Helper function for common bits of parsing cfg.ttymodes. */
897 static void parse_ttymodes(Ssh ssh, char *modes,
898 void (*do_mode)(void *data, char *mode, char *val),
902 char *t = strchr(modes, '\t');
903 char *m = snewn(t-modes+1, char);
905 strncpy(m, modes, t-modes);
908 val = get_ttymode(ssh->frontend, m);
912 do_mode(data, m, val);
915 modes += strlen(modes) + 1;
919 static int ssh_channelcmp(void *av, void *bv)
921 struct ssh_channel *a = (struct ssh_channel *) av;
922 struct ssh_channel *b = (struct ssh_channel *) bv;
923 if (a->localid < b->localid)
925 if (a->localid > b->localid)
929 static int ssh_channelfind(void *av, void *bv)
931 unsigned *a = (unsigned *) av;
932 struct ssh_channel *b = (struct ssh_channel *) bv;
940 static int ssh_rportcmp_ssh1(void *av, void *bv)
942 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
943 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
945 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
946 return i < 0 ? -1 : +1;
947 if (a->dport > b->dport)
949 if (a->dport < b->dport)
954 static int ssh_rportcmp_ssh2(void *av, void *bv)
956 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
957 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
959 if (a->sport > b->sport)
961 if (a->sport < b->sport)
967 * Special form of strcmp which can cope with NULL inputs. NULL is
968 * defined to sort before even the empty string.
970 static int nullstrcmp(const char *a, const char *b)
972 if (a == NULL && b == NULL)
981 static int ssh_portcmp(void *av, void *bv)
983 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
984 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
986 if (a->type > b->type)
988 if (a->type < b->type)
990 if (a->addressfamily > b->addressfamily)
992 if (a->addressfamily < b->addressfamily)
994 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
995 return i < 0 ? -1 : +1;
996 if (a->sport > b->sport)
998 if (a->sport < b->sport)
1000 if (a->type != 'D') {
1001 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1002 return i < 0 ? -1 : +1;
1003 if (a->dport > b->dport)
1005 if (a->dport < b->dport)
1011 static int alloc_channel_id(Ssh ssh)
1013 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1014 unsigned low, high, mid;
1016 struct ssh_channel *c;
1019 * First-fit allocation of channel numbers: always pick the
1020 * lowest unused one. To do this, binary-search using the
1021 * counted B-tree to find the largest channel ID which is in a
1022 * contiguous sequence from the beginning. (Precisely
1023 * everything in that sequence must have ID equal to its tree
1024 * index plus CHANNEL_NUMBER_OFFSET.)
1026 tsize = count234(ssh->channels);
1030 while (high - low > 1) {
1031 mid = (high + low) / 2;
1032 c = index234(ssh->channels, mid);
1033 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1034 low = mid; /* this one is fine */
1036 high = mid; /* this one is past it */
1039 * Now low points to either -1, or the tree index of the
1040 * largest ID in the initial sequence.
1043 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1044 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1046 return low + 1 + CHANNEL_NUMBER_OFFSET;
1049 static void c_write(Ssh ssh, const char *buf, int len)
1051 if ((flags & FLAG_STDERR)) {
1053 for (i = 0; i < len; i++)
1055 fputc(buf[i], stderr);
1058 from_backend(ssh->frontend, 1, buf, len);
1061 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1064 for (i = 0; i < len; i++) {
1066 c_write(ssh, "\r\n", 2);
1067 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
1068 c_write(ssh, buf + i, 1);
1072 static void c_write_str(Ssh ssh, const char *buf)
1074 c_write(ssh, buf, strlen(buf));
1077 static void ssh_free_packet(struct Packet *pkt)
1082 static struct Packet *ssh_new_packet(void)
1084 struct Packet *pkt = snew(struct Packet);
1086 pkt->body = pkt->data = NULL;
1088 pkt->logmode = PKTLOG_EMIT;
1096 * Collect incoming data in the incoming packet buffer.
1097 * Decipher and verify the packet when it is completely read.
1098 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1099 * Update the *data and *datalen variables.
1100 * Return a Packet structure when a packet is completed.
1102 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1104 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1106 crBegin(ssh->ssh1_rdpkt_crstate);
1108 st->pktin = ssh_new_packet();
1110 st->pktin->type = 0;
1111 st->pktin->length = 0;
1113 for (st->i = st->len = 0; st->i < 4; st->i++) {
1114 while ((*datalen) == 0)
1116 st->len = (st->len << 8) + **data;
1117 (*data)++, (*datalen)--;
1120 st->pad = 8 - (st->len % 8);
1121 st->biglen = st->len + st->pad;
1122 st->pktin->length = st->len - 5;
1124 if (st->biglen < 0) {
1125 bombout(("Extremely large packet length from server suggests"
1126 " data stream corruption"));
1127 ssh_free_packet(st->pktin);
1131 st->pktin->maxlen = st->biglen;
1132 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1134 st->to_read = st->biglen;
1135 st->p = st->pktin->data;
1136 while (st->to_read > 0) {
1137 st->chunk = st->to_read;
1138 while ((*datalen) == 0)
1140 if (st->chunk > (*datalen))
1141 st->chunk = (*datalen);
1142 memcpy(st->p, *data, st->chunk);
1144 *datalen -= st->chunk;
1146 st->to_read -= st->chunk;
1149 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1150 st->biglen, NULL)) {
1151 bombout(("Network attack (CRC compensation) detected!"));
1152 ssh_free_packet(st->pktin);
1157 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1159 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1160 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1161 if (st->gotcrc != st->realcrc) {
1162 bombout(("Incorrect CRC received on packet"));
1163 ssh_free_packet(st->pktin);
1167 st->pktin->body = st->pktin->data + st->pad + 1;
1168 st->pktin->savedpos = 0;
1170 if (ssh->v1_compressing) {
1171 unsigned char *decompblk;
1173 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1174 st->pktin->body - 1, st->pktin->length + 1,
1175 &decompblk, &decomplen)) {
1176 bombout(("Zlib decompression encountered invalid data"));
1177 ssh_free_packet(st->pktin);
1181 if (st->pktin->maxlen < st->pad + decomplen) {
1182 st->pktin->maxlen = st->pad + decomplen;
1183 st->pktin->data = sresize(st->pktin->data,
1184 st->pktin->maxlen + APIEXTRA,
1186 st->pktin->body = st->pktin->data + st->pad + 1;
1189 memcpy(st->pktin->body - 1, decompblk, decomplen);
1191 st->pktin->length = decomplen - 1;
1194 st->pktin->type = st->pktin->body[-1];
1197 * Log incoming packet, possibly omitting sensitive fields.
1201 struct logblank_t blank;
1202 if (ssh->cfg.logomitdata) {
1203 int do_blank = FALSE, blank_prefix = 0;
1204 /* "Session data" packets - omit the data field */
1205 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1206 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1207 do_blank = TRUE; blank_prefix = 0;
1208 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1209 do_blank = TRUE; blank_prefix = 4;
1212 blank.offset = blank_prefix;
1213 blank.len = st->pktin->length;
1214 blank.type = PKTLOG_OMIT;
1218 log_packet(ssh->logctx,
1219 PKT_INCOMING, st->pktin->type,
1220 ssh1_pkt_type(st->pktin->type),
1221 st->pktin->body, st->pktin->length,
1225 crFinish(st->pktin);
1228 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1230 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1232 crBegin(ssh->ssh2_rdpkt_crstate);
1234 st->pktin = ssh_new_packet();
1236 st->pktin->type = 0;
1237 st->pktin->length = 0;
1239 st->cipherblk = ssh->sccipher->blksize;
1242 if (st->cipherblk < 8)
1245 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1248 * Acquire and decrypt the first block of the packet. This will
1249 * contain the length and padding details.
1251 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1252 while ((*datalen) == 0)
1254 st->pktin->data[st->i] = *(*data)++;
1259 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1260 st->pktin->data, st->cipherblk);
1263 * Now get the length and padding figures.
1265 st->len = GET_32BIT(st->pktin->data);
1266 st->pad = st->pktin->data[4];
1269 * _Completely_ silly lengths should be stomped on before they
1270 * do us any more damage.
1272 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1273 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
1274 bombout(("Incoming packet was garbled on decryption"));
1275 ssh_free_packet(st->pktin);
1280 * This enables us to deduce the payload length.
1282 st->payload = st->len - st->pad - 1;
1284 st->pktin->length = st->payload + 5;
1287 * So now we can work out the total packet length.
1289 st->packetlen = st->len + 4;
1290 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1293 * Allocate memory for the rest of the packet.
1295 st->pktin->maxlen = st->packetlen + st->maclen;
1296 st->pktin->data = sresize(st->pktin->data,
1297 st->pktin->maxlen + APIEXTRA,
1301 * Read and decrypt the remainder of the packet.
1303 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1305 while ((*datalen) == 0)
1307 st->pktin->data[st->i] = *(*data)++;
1310 /* Decrypt everything _except_ the MAC. */
1312 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1313 st->pktin->data + st->cipherblk,
1314 st->packetlen - st->cipherblk);
1316 st->pktin->encrypted_len = st->packetlen;
1322 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1323 st->incoming_sequence)) {
1324 bombout(("Incorrect MAC received on packet"));
1325 ssh_free_packet(st->pktin);
1329 st->pktin->sequence = st->incoming_sequence++;
1332 * Decompress packet payload.
1335 unsigned char *newpayload;
1338 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1339 st->pktin->data + 5, st->pktin->length - 5,
1340 &newpayload, &newlen)) {
1341 if (st->pktin->maxlen < newlen + 5) {
1342 st->pktin->maxlen = newlen + 5;
1343 st->pktin->data = sresize(st->pktin->data,
1344 st->pktin->maxlen + APIEXTRA,
1347 st->pktin->length = 5 + newlen;
1348 memcpy(st->pktin->data + 5, newpayload, newlen);
1353 st->pktin->savedpos = 6;
1354 st->pktin->body = st->pktin->data;
1355 st->pktin->type = st->pktin->data[5];
1358 * Log incoming packet, possibly omitting sensitive fields.
1362 struct logblank_t blank;
1363 if (ssh->cfg.logomitdata) {
1364 int do_blank = FALSE, blank_prefix = 0;
1365 /* "Session data" packets - omit the data field */
1366 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1367 do_blank = TRUE; blank_prefix = 4;
1368 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1369 do_blank = TRUE; blank_prefix = 8;
1372 blank.offset = blank_prefix;
1373 blank.len = (st->pktin->length-6) - blank_prefix;
1374 blank.type = PKTLOG_OMIT;
1378 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1379 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1380 st->pktin->data+6, st->pktin->length-6,
1384 crFinish(st->pktin);
1387 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1389 int pad, biglen, i, pktoffs;
1393 * XXX various versions of SC (including 8.8.4) screw up the
1394 * register allocation in this function and use the same register
1395 * (D6) for len and as a temporary, with predictable results. The
1396 * following sledgehammer prevents this.
1403 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1404 ssh1_pkt_type(pkt->data[12]),
1405 pkt->body, pkt->length - (pkt->body - pkt->data),
1406 pkt->nblanks, pkt->blanks);
1407 sfree(pkt->blanks); pkt->blanks = NULL;
1410 if (ssh->v1_compressing) {
1411 unsigned char *compblk;
1413 zlib_compress_block(ssh->cs_comp_ctx,
1414 pkt->data + 12, pkt->length - 12,
1415 &compblk, &complen);
1416 memcpy(pkt->data + 12, compblk, complen);
1418 pkt->length = complen + 12;
1421 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1423 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1424 pad = 8 - (len % 8);
1426 biglen = len + pad; /* len(padding+type+data+CRC) */
1428 for (i = pktoffs; i < 4+8; i++)
1429 pkt->data[i] = random_byte();
1430 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1431 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1432 PUT_32BIT(pkt->data + pktoffs, len);
1435 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1436 pkt->data + pktoffs + 4, biglen);
1438 if (offset_p) *offset_p = pktoffs;
1439 return biglen + 4; /* len(length+padding+type+data+CRC) */
1442 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1444 int len, backlog, offset;
1445 len = s_wrpkt_prepare(ssh, pkt, &offset);
1446 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1447 if (backlog > SSH_MAX_BACKLOG)
1448 ssh_throttle_all(ssh, 1, backlog);
1449 ssh_free_packet(pkt);
1452 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1455 len = s_wrpkt_prepare(ssh, pkt, &offset);
1456 if (ssh->deferred_len + len > ssh->deferred_size) {
1457 ssh->deferred_size = ssh->deferred_len + len + 128;
1458 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1462 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1463 pkt->data + offset, len);
1464 ssh->deferred_len += len;
1465 ssh_free_packet(pkt);
1469 * Construct a SSH-1 packet with the specified contents.
1470 * (This all-at-once interface used to be the only one, but now SSH-1
1471 * packets can also be constructed incrementally.)
1473 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1479 pkt = ssh1_pkt_init(pkttype);
1481 while ((argtype = va_arg(ap, int)) != PKT_END) {
1482 unsigned char *argp, argchar;
1483 unsigned long argint;
1486 /* Actual fields in the packet */
1488 argint = va_arg(ap, int);
1489 ssh_pkt_adduint32(pkt, argint);
1492 argchar = (unsigned char) va_arg(ap, int);
1493 ssh_pkt_addbyte(pkt, argchar);
1496 argp = va_arg(ap, unsigned char *);
1497 arglen = va_arg(ap, int);
1498 ssh_pkt_adddata(pkt, argp, arglen);
1501 argp = va_arg(ap, unsigned char *);
1502 ssh_pkt_addstring(pkt, argp);
1505 bn = va_arg(ap, Bignum);
1506 ssh1_pkt_addmp(pkt, bn);
1508 /* Tokens for modifications to packet logging */
1510 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1513 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1516 end_log_omission(ssh, pkt);
1524 static void send_packet(Ssh ssh, int pkttype, ...)
1528 va_start(ap, pkttype);
1529 pkt = construct_packet(ssh, pkttype, ap);
1534 static void defer_packet(Ssh ssh, int pkttype, ...)
1538 va_start(ap, pkttype);
1539 pkt = construct_packet(ssh, pkttype, ap);
1541 s_wrpkt_defer(ssh, pkt);
1544 static int ssh_versioncmp(char *a, char *b)
1547 unsigned long av, bv;
1549 av = strtoul(a, &ae, 10);
1550 bv = strtoul(b, &be, 10);
1552 return (av < bv ? -1 : +1);
1557 av = strtoul(ae, &ae, 10);
1558 bv = strtoul(be, &be, 10);
1560 return (av < bv ? -1 : +1);
1565 * Utility routines for putting an SSH-protocol `string' and
1566 * `uint32' into a hash state.
1568 static void hash_string(const struct ssh_hash *h, void *s, void *str, int len)
1570 unsigned char lenblk[4];
1571 PUT_32BIT(lenblk, len);
1572 h->bytes(s, lenblk, 4);
1573 h->bytes(s, str, len);
1576 static void hash_uint32(const struct ssh_hash *h, void *s, unsigned i)
1578 unsigned char intblk[4];
1579 PUT_32BIT(intblk, i);
1580 h->bytes(s, intblk, 4);
1584 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1586 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1588 if (pkt->maxlen < length) {
1589 unsigned char *body = pkt->body;
1590 int offset = body ? pkt->data - body : 0;
1591 pkt->maxlen = length + 256;
1592 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1593 if (body) pkt->body = pkt->data + offset;
1596 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1598 if (pkt->logmode != PKTLOG_EMIT) {
1600 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1602 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1603 (pkt->body - pkt->data);
1604 pkt->blanks[pkt->nblanks-1].len = len;
1605 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1608 ssh_pkt_ensure(pkt, pkt->length);
1609 memcpy(pkt->data + pkt->length - len, data, len);
1611 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1613 ssh_pkt_adddata(pkt, &byte, 1);
1615 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1617 ssh_pkt_adddata(pkt, &value, 1);
1619 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1622 PUT_32BIT(x, value);
1623 ssh_pkt_adddata(pkt, x, 4);
1625 static void ssh_pkt_addstring_start(struct Packet *pkt)
1627 ssh_pkt_adduint32(pkt, 0);
1628 pkt->savedpos = pkt->length;
1630 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1632 ssh_pkt_adddata(pkt, data, strlen(data));
1633 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1635 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1637 ssh_pkt_adddata(pkt, data, len);
1638 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1640 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1642 ssh_pkt_addstring_start(pkt);
1643 ssh_pkt_addstring_str(pkt, data);
1645 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1647 int len = ssh1_bignum_length(b);
1648 unsigned char *data = snewn(len, char);
1649 (void) ssh1_write_bignum(data, b);
1650 ssh_pkt_adddata(pkt, data, len);
1653 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1656 int i, n = (bignum_bitcount(b) + 7) / 8;
1657 p = snewn(n + 1, unsigned char);
1659 for (i = 1; i <= n; i++)
1660 p[i] = bignum_byte(b, n - i);
1662 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1664 memmove(p, p + i, n + 1 - i);
1668 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1672 p = ssh2_mpint_fmt(b, &len);
1673 ssh_pkt_addstring_start(pkt);
1674 ssh_pkt_addstring_data(pkt, (char *)p, len);
1678 static struct Packet *ssh1_pkt_init(int pkt_type)
1680 struct Packet *pkt = ssh_new_packet();
1681 pkt->length = 4 + 8; /* space for length + max padding */
1682 ssh_pkt_addbyte(pkt, pkt_type);
1683 pkt->body = pkt->data + pkt->length;
1687 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1688 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1689 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1690 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1691 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1692 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1693 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1694 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1695 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1697 static struct Packet *ssh2_pkt_init(int pkt_type)
1699 struct Packet *pkt = ssh_new_packet();
1702 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1703 pkt->body = pkt->data + pkt->length;
1708 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1709 * put the MAC on it. Final packet, ready to be sent, is stored in
1710 * pkt->data. Total length is returned.
1712 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1714 int cipherblk, maclen, padding, i;
1717 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1718 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1719 pkt->body, pkt->length - (pkt->body - pkt->data),
1720 pkt->nblanks, pkt->blanks);
1721 sfree(pkt->blanks); pkt->blanks = NULL;
1725 * Compress packet payload.
1728 unsigned char *newpayload;
1731 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1733 &newpayload, &newlen)) {
1735 ssh2_pkt_adddata(pkt, newpayload, newlen);
1741 * Add padding. At least four bytes, and must also bring total
1742 * length (minus MAC) up to a multiple of the block size.
1743 * If pkt->forcepad is set, make sure the packet is at least that size
1746 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1747 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1749 if (pkt->length + padding < pkt->forcepad)
1750 padding = pkt->forcepad - pkt->length;
1752 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1753 assert(padding <= 255);
1754 maclen = ssh->csmac ? ssh->csmac->len : 0;
1755 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1756 pkt->data[4] = padding;
1757 for (i = 0; i < padding; i++)
1758 pkt->data[pkt->length + i] = random_byte();
1759 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1761 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1762 pkt->length + padding,
1763 ssh->v2_outgoing_sequence);
1764 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1767 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1768 pkt->data, pkt->length + padding);
1770 pkt->encrypted_len = pkt->length + padding;
1772 /* Ready-to-send packet starts at pkt->data. We return length. */
1773 return pkt->length + padding + maclen;
1777 * Routines called from the main SSH code to send packets. There
1778 * are quite a few of these, because we have two separate
1779 * mechanisms for delaying the sending of packets:
1781 * - In order to send an IGNORE message and a password message in
1782 * a single fixed-length blob, we require the ability to
1783 * concatenate the encrypted forms of those two packets _into_ a
1784 * single blob and then pass it to our <network.h> transport
1785 * layer in one go. Hence, there's a deferment mechanism which
1786 * works after packet encryption.
1788 * - In order to avoid sending any connection-layer messages
1789 * during repeat key exchange, we have to queue up any such
1790 * outgoing messages _before_ they are encrypted (and in
1791 * particular before they're allocated sequence numbers), and
1792 * then send them once we've finished.
1794 * I call these mechanisms `defer' and `queue' respectively, so as
1795 * to distinguish them reasonably easily.
1797 * The functions send_noqueue() and defer_noqueue() free the packet
1798 * structure they are passed. Every outgoing packet goes through
1799 * precisely one of these functions in its life; packets passed to
1800 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1801 * these or get queued, and then when the queue is later emptied
1802 * the packets are all passed to defer_noqueue().
1804 * When using a CBC-mode cipher, it's necessary to ensure that an
1805 * attacker can't provide data to be encrypted using an IV that they
1806 * know. We ensure this by prefixing each packet that might contain
1807 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1808 * mechanism, so in this case send_noqueue() ends up redirecting to
1809 * defer_noqueue(). If you don't like this inefficiency, don't use
1813 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1814 static void ssh_pkt_defersend(Ssh);
1817 * Send an SSH-2 packet immediately, without queuing or deferring.
1819 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1823 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1824 /* We need to send two packets, so use the deferral mechanism. */
1825 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1826 ssh_pkt_defersend(ssh);
1829 len = ssh2_pkt_construct(ssh, pkt);
1830 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1831 if (backlog > SSH_MAX_BACKLOG)
1832 ssh_throttle_all(ssh, 1, backlog);
1834 ssh->outgoing_data_size += pkt->encrypted_len;
1835 if (!ssh->kex_in_progress &&
1836 ssh->max_data_size != 0 &&
1837 ssh->outgoing_data_size > ssh->max_data_size)
1838 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1840 ssh_free_packet(pkt);
1844 * Defer an SSH-2 packet.
1846 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1849 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1850 ssh->deferred_len == 0 && !noignore) {
1852 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1853 * get encrypted with a known IV.
1855 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1856 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1858 len = ssh2_pkt_construct(ssh, pkt);
1859 if (ssh->deferred_len + len > ssh->deferred_size) {
1860 ssh->deferred_size = ssh->deferred_len + len + 128;
1861 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1865 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1866 ssh->deferred_len += len;
1867 ssh->deferred_data_size += pkt->encrypted_len;
1868 ssh_free_packet(pkt);
1872 * Queue an SSH-2 packet.
1874 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1876 assert(ssh->queueing);
1878 if (ssh->queuelen >= ssh->queuesize) {
1879 ssh->queuesize = ssh->queuelen + 32;
1880 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1883 ssh->queue[ssh->queuelen++] = pkt;
1887 * Either queue or send a packet, depending on whether queueing is
1890 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1893 ssh2_pkt_queue(ssh, pkt);
1895 ssh2_pkt_send_noqueue(ssh, pkt);
1900 * Either queue or defer a packet, depending on whether queueing is
1903 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1906 ssh2_pkt_queue(ssh, pkt);
1908 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1913 * Send the whole deferred data block constructed by
1914 * ssh2_pkt_defer() or SSH-1's defer_packet().
1916 * The expected use of the defer mechanism is that you call
1917 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1918 * not currently queueing, this simply sets up deferred_send_data
1919 * and then sends it. If we _are_ currently queueing, the calls to
1920 * ssh2_pkt_defer() put the deferred packets on to the queue
1921 * instead, and therefore ssh_pkt_defersend() has no deferred data
1922 * to send. Hence, there's no need to make it conditional on
1925 static void ssh_pkt_defersend(Ssh ssh)
1928 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1930 ssh->deferred_len = ssh->deferred_size = 0;
1931 sfree(ssh->deferred_send_data);
1932 ssh->deferred_send_data = NULL;
1933 if (backlog > SSH_MAX_BACKLOG)
1934 ssh_throttle_all(ssh, 1, backlog);
1936 ssh->outgoing_data_size += ssh->deferred_data_size;
1937 if (!ssh->kex_in_progress &&
1938 ssh->max_data_size != 0 &&
1939 ssh->outgoing_data_size > ssh->max_data_size)
1940 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1941 ssh->deferred_data_size = 0;
1945 * Send all queued SSH-2 packets. We send them by means of
1946 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1947 * packets that needed to be lumped together.
1949 static void ssh2_pkt_queuesend(Ssh ssh)
1953 assert(!ssh->queueing);
1955 for (i = 0; i < ssh->queuelen; i++)
1956 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
1959 ssh_pkt_defersend(ssh);
1963 void bndebug(char *string, Bignum b)
1967 p = ssh2_mpint_fmt(b, &len);
1968 debug(("%s", string));
1969 for (i = 0; i < len; i++)
1970 debug((" %02x", p[i]));
1976 static void hash_mpint(const struct ssh_hash *h, void *s, Bignum b)
1980 p = ssh2_mpint_fmt(b, &len);
1981 hash_string(h, s, p, len);
1986 * Packet decode functions for both SSH-1 and SSH-2.
1988 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1990 unsigned long value;
1991 if (pkt->length - pkt->savedpos < 4)
1992 return 0; /* arrgh, no way to decline (FIXME?) */
1993 value = GET_32BIT(pkt->body + pkt->savedpos);
1997 static int ssh2_pkt_getbool(struct Packet *pkt)
1999 unsigned long value;
2000 if (pkt->length - pkt->savedpos < 1)
2001 return 0; /* arrgh, no way to decline (FIXME?) */
2002 value = pkt->body[pkt->savedpos] != 0;
2006 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2011 if (pkt->length - pkt->savedpos < 4)
2013 len = GET_32BIT(pkt->body + pkt->savedpos);
2018 if (pkt->length - pkt->savedpos < *length)
2020 *p = (char *)(pkt->body + pkt->savedpos);
2021 pkt->savedpos += *length;
2023 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2025 if (pkt->length - pkt->savedpos < length)
2027 pkt->savedpos += length;
2028 return pkt->body + (pkt->savedpos - length);
2030 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2031 unsigned char **keystr)
2035 j = makekey(pkt->body + pkt->savedpos,
2036 pkt->length - pkt->savedpos,
2043 assert(pkt->savedpos < pkt->length);
2047 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2052 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2053 pkt->length - pkt->savedpos, &b);
2061 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2067 ssh_pkt_getstring(pkt, &p, &length);
2072 b = bignum_from_bytes((unsigned char *)p, length);
2077 * Helper function to add an SSH-2 signature blob to a packet.
2078 * Expects to be shown the public key blob as well as the signature
2079 * blob. Normally works just like ssh2_pkt_addstring, but will
2080 * fiddle with the signature packet if necessary for
2081 * BUG_SSH2_RSA_PADDING.
2083 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2084 void *pkblob_v, int pkblob_len,
2085 void *sigblob_v, int sigblob_len)
2087 unsigned char *pkblob = (unsigned char *)pkblob_v;
2088 unsigned char *sigblob = (unsigned char *)sigblob_v;
2090 /* dmemdump(pkblob, pkblob_len); */
2091 /* dmemdump(sigblob, sigblob_len); */
2094 * See if this is in fact an ssh-rsa signature and a buggy
2095 * server; otherwise we can just do this the easy way.
2097 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2098 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2099 int pos, len, siglen;
2102 * Find the byte length of the modulus.
2105 pos = 4+7; /* skip over "ssh-rsa" */
2106 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2107 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2108 pos += 4; /* find modulus itself */
2109 while (len > 0 && pkblob[pos] == 0)
2111 /* debug(("modulus length is %d\n", len)); */
2114 * Now find the signature integer.
2116 pos = 4+7; /* skip over "ssh-rsa" */
2117 siglen = GET_32BIT(sigblob+pos);
2118 /* debug(("signature length is %d\n", siglen)); */
2120 if (len != siglen) {
2121 unsigned char newlen[4];
2122 ssh2_pkt_addstring_start(pkt);
2123 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2124 /* dmemdump(sigblob, pos); */
2125 pos += 4; /* point to start of actual sig */
2126 PUT_32BIT(newlen, len);
2127 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2128 /* dmemdump(newlen, 4); */
2130 while (len-- > siglen) {
2131 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2132 /* dmemdump(newlen, 1); */
2134 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2135 /* dmemdump(sigblob+pos, siglen); */
2139 /* Otherwise fall through and do it the easy way. */
2142 ssh2_pkt_addstring_start(pkt);
2143 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2147 * Examine the remote side's version string and compare it against
2148 * a list of known buggy implementations.
2150 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2152 char *imp; /* pointer to implementation part */
2154 imp += strcspn(imp, "-");
2156 imp += strcspn(imp, "-");
2159 ssh->remote_bugs = 0;
2161 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2162 (ssh->cfg.sshbug_ignore1 == AUTO &&
2163 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2164 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2165 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2166 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2168 * These versions don't support SSH1_MSG_IGNORE, so we have
2169 * to use a different defence against password length
2172 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2173 logevent("We believe remote version has SSH-1 ignore bug");
2176 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2177 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2178 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2180 * These versions need a plain password sent; they can't
2181 * handle having a null and a random length of data after
2184 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2185 logevent("We believe remote version needs a plain SSH-1 password");
2188 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2189 (ssh->cfg.sshbug_rsa1 == AUTO &&
2190 (!strcmp(imp, "Cisco-1.25")))) {
2192 * These versions apparently have no clue whatever about
2193 * RSA authentication and will panic and die if they see
2194 * an AUTH_RSA message.
2196 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2197 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2200 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2201 (ssh->cfg.sshbug_hmac2 == AUTO &&
2202 !wc_match("* VShell", imp) &&
2203 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2204 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2205 wc_match("2.1 *", imp)))) {
2207 * These versions have the HMAC bug.
2209 ssh->remote_bugs |= BUG_SSH2_HMAC;
2210 logevent("We believe remote version has SSH-2 HMAC bug");
2213 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2214 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2215 !wc_match("* VShell", imp) &&
2216 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2218 * These versions have the key-derivation bug (failing to
2219 * include the literal shared secret in the hashes that
2220 * generate the keys).
2222 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2223 logevent("We believe remote version has SSH-2 key-derivation bug");
2226 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2227 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2228 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2229 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2231 * These versions have the SSH-2 RSA padding bug.
2233 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2234 logevent("We believe remote version has SSH-2 RSA padding bug");
2237 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2238 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2239 wc_match("OpenSSH_2.[0-2]*", imp))) {
2241 * These versions have the SSH-2 session-ID bug in
2242 * public-key authentication.
2244 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2245 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2248 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2249 (ssh->cfg.sshbug_rekey2 == AUTO &&
2250 (wc_match("DigiSSH_2.0", imp) ||
2251 wc_match("OpenSSH_2.[0-4]*", imp) ||
2252 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2253 wc_match("Sun_SSH_1.0", imp) ||
2254 wc_match("Sun_SSH_1.0.1", imp) ||
2255 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2256 wc_match("WeOnlyDo-*", imp)))) {
2258 * These versions have the SSH-2 rekey bug.
2260 ssh->remote_bugs |= BUG_SSH2_REKEY;
2261 logevent("We believe remote version has SSH-2 rekey bug");
2266 * The `software version' part of an SSH version string is required
2267 * to contain no spaces or minus signs.
2269 static void ssh_fix_verstring(char *str)
2271 /* Eat "SSH-<protoversion>-". */
2272 assert(*str == 'S'); str++;
2273 assert(*str == 'S'); str++;
2274 assert(*str == 'H'); str++;
2275 assert(*str == '-'); str++;
2276 while (*str && *str != '-') str++;
2277 assert(*str == '-'); str++;
2279 /* Convert minus signs and spaces in the remaining string into
2282 if (*str == '-' || *str == ' ')
2288 static int do_ssh_init(Ssh ssh, unsigned char c)
2290 struct do_ssh_init_state {
2298 crState(do_ssh_init_state);
2300 crBegin(ssh->do_ssh_init_crstate);
2302 /* Search for a line beginning with the string "SSH-" in the input. */
2304 if (c != 'S') goto no;
2306 if (c != 'S') goto no;
2308 if (c != 'H') goto no;
2310 if (c != '-') goto no;
2319 s->vstring = snewn(s->vstrsize, char);
2320 strcpy(s->vstring, "SSH-");
2324 crReturn(1); /* get another char */
2325 if (s->vslen >= s->vstrsize - 1) {
2327 s->vstring = sresize(s->vstring, s->vstrsize, char);
2329 s->vstring[s->vslen++] = c;
2332 s->version[s->i] = '\0';
2334 } else if (s->i < sizeof(s->version) - 1)
2335 s->version[s->i++] = c;
2336 } else if (c == '\012')
2340 ssh->agentfwd_enabled = FALSE;
2341 ssh->rdpkt2_state.incoming_sequence = 0;
2343 s->vstring[s->vslen] = 0;
2344 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2345 logeventf(ssh, "Server version: %s", s->vstring);
2346 ssh_detect_bugs(ssh, s->vstring);
2349 * Decide which SSH protocol version to support.
2352 /* Anything strictly below "2.0" means protocol 1 is supported. */
2353 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2354 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2355 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2357 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2358 bombout(("SSH protocol version 1 required by user but not provided by server"));
2361 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2362 bombout(("SSH protocol version 2 required by user but not provided by server"));
2369 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2371 * Construct a v2 version string.
2373 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2377 * Construct a v1 version string.
2379 verstring = dupprintf("SSH-%s-%s\012",
2380 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2381 s->version : "1.5"),
2386 ssh_fix_verstring(verstring);
2388 if (ssh->version == 2) {
2391 * Hash our version string and their version string.
2393 len = strcspn(verstring, "\015\012");
2394 ssh->v_c = snewn(len + 1, char);
2395 memcpy(ssh->v_c, verstring, len);
2397 len = strcspn(s->vstring, "\015\012");
2398 ssh->v_s = snewn(len + 1, char);
2399 memcpy(ssh->v_s, s->vstring, len);
2403 * Initialise SSH-2 protocol.
2405 ssh->protocol = ssh2_protocol;
2406 ssh2_protocol_setup(ssh);
2407 ssh->s_rdpkt = ssh2_rdpkt;
2410 * Initialise SSH-1 protocol.
2412 ssh->protocol = ssh1_protocol;
2413 ssh1_protocol_setup(ssh);
2414 ssh->s_rdpkt = ssh1_rdpkt;
2416 logeventf(ssh, "We claim version: %.*s",
2417 strcspn(verstring, "\015\012"), verstring);
2418 sk_write(ssh->s, verstring, strlen(verstring));
2420 if (ssh->version == 2)
2421 do_ssh2_transport(ssh, NULL, -1, NULL);
2424 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2426 update_specials_menu(ssh->frontend);
2427 ssh->state = SSH_STATE_BEFORE_SIZE;
2428 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2435 static void ssh_process_incoming_data(Ssh ssh,
2436 unsigned char **data, int *datalen)
2438 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2440 ssh->protocol(ssh, NULL, 0, pktin);
2441 ssh_free_packet(pktin);
2445 static void ssh_queue_incoming_data(Ssh ssh,
2446 unsigned char **data, int *datalen)
2448 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2453 static void ssh_process_queued_incoming_data(Ssh ssh)
2456 unsigned char *data;
2459 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2460 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2464 while (!ssh->frozen && len > 0)
2465 ssh_process_incoming_data(ssh, &data, &len);
2468 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2472 static void ssh_set_frozen(Ssh ssh, int frozen)
2475 sk_set_frozen(ssh->s, frozen);
2476 ssh->frozen = frozen;
2479 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2481 crBegin(ssh->ssh_gotdata_crstate);
2484 * To begin with, feed the characters one by one to the
2485 * protocol initialisation / selection function do_ssh_init().
2486 * When that returns 0, we're done with the initial greeting
2487 * exchange and can move on to packet discipline.
2490 int ret; /* need not be kept across crReturn */
2492 crReturnV; /* more data please */
2493 ret = do_ssh_init(ssh, *data);
2501 * We emerge from that loop when the initial negotiation is
2502 * over and we have selected an s_rdpkt function. Now pass
2503 * everything to s_rdpkt, and then pass the resulting packets
2504 * to the proper protocol handler.
2508 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2510 ssh_queue_incoming_data(ssh, &data, &datalen);
2511 /* This uses up all data and cannot cause anything interesting
2512 * to happen; indeed, for anything to happen at all, we must
2513 * return, so break out. */
2515 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2516 /* This uses up some or all data, and may freeze the
2518 ssh_process_queued_incoming_data(ssh);
2520 /* This uses up some or all data, and may freeze the
2522 ssh_process_incoming_data(ssh, &data, &datalen);
2524 /* FIXME this is probably EBW. */
2525 if (ssh->state == SSH_STATE_CLOSED)
2528 /* We're out of data. Go and get some more. */
2534 static int ssh_do_close(Ssh ssh, int notify_exit)
2537 struct ssh_channel *c;
2539 ssh->state = SSH_STATE_CLOSED;
2540 expire_timer_context(ssh);
2545 notify_remote_exit(ssh->frontend);
2550 * Now we must shut down any port- and X-forwarded channels going
2551 * through this connection.
2553 if (ssh->channels) {
2554 while (NULL != (c = index234(ssh->channels, 0))) {
2557 x11_close(c->u.x11.s);
2560 pfd_close(c->u.pfd.s);
2563 del234(ssh->channels, c); /* moving next one to index 0 */
2564 if (ssh->version == 2)
2565 bufchain_clear(&c->v.v2.outbuffer);
2570 * Go through port-forwardings, and close any associated
2571 * listening sockets.
2573 if (ssh->portfwds) {
2574 struct ssh_portfwd *pf;
2575 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2576 /* Dispose of any listening socket. */
2578 pfd_terminate(pf->local);
2579 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2587 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2588 const char *error_msg, int error_code)
2590 Ssh ssh = (Ssh) plug;
2591 char addrbuf[256], *msg;
2593 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2596 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2598 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2604 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2607 Ssh ssh = (Ssh) plug;
2608 int need_notify = ssh_do_close(ssh, FALSE);
2611 if (!ssh->close_expected)
2612 error_msg = "Server unexpectedly closed network connection";
2614 error_msg = "Server closed network connection";
2618 notify_remote_exit(ssh->frontend);
2621 logevent(error_msg);
2622 if (!ssh->close_expected || !ssh->clean_exit)
2623 connection_fatal(ssh->frontend, "%s", error_msg);
2627 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2629 Ssh ssh = (Ssh) plug;
2630 ssh_gotdata(ssh, (unsigned char *)data, len);
2631 if (ssh->state == SSH_STATE_CLOSED) {
2632 ssh_do_close(ssh, TRUE);
2638 static void ssh_sent(Plug plug, int bufsize)
2640 Ssh ssh = (Ssh) plug;
2642 * If the send backlog on the SSH socket itself clears, we
2643 * should unthrottle the whole world if it was throttled.
2645 if (bufsize < SSH_MAX_BACKLOG)
2646 ssh_throttle_all(ssh, 0, bufsize);
2650 * Connect to specified host and port.
2651 * Returns an error message, or NULL on success.
2652 * Also places the canonical host name into `realhost'. It must be
2653 * freed by the caller.
2655 static const char *connect_to_host(Ssh ssh, char *host, int port,
2656 char **realhost, int nodelay, int keepalive)
2658 static const struct plug_function_table fn_table = {
2669 ssh->savedhost = snewn(1 + strlen(host), char);
2670 strcpy(ssh->savedhost, host);
2673 port = 22; /* default ssh port */
2674 ssh->savedport = port;
2679 logeventf(ssh, "Looking up host \"%s\"%s", host,
2680 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2681 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2682 addr = name_lookup(host, port, realhost, &ssh->cfg,
2683 ssh->cfg.addressfamily);
2684 if ((err = sk_addr_error(addr)) != NULL) {
2692 ssh->fn = &fn_table;
2693 ssh->s = new_connection(addr, *realhost, port,
2694 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2695 if ((err = sk_socket_error(ssh->s)) != NULL) {
2697 notify_remote_exit(ssh->frontend);
2705 * Throttle or unthrottle the SSH connection.
2707 static void ssh1_throttle(Ssh ssh, int adjust)
2709 int old_count = ssh->v1_throttle_count;
2710 ssh->v1_throttle_count += adjust;
2711 assert(ssh->v1_throttle_count >= 0);
2712 if (ssh->v1_throttle_count && !old_count) {
2713 ssh_set_frozen(ssh, 1);
2714 } else if (!ssh->v1_throttle_count && old_count) {
2715 ssh_set_frozen(ssh, 0);
2720 * Throttle or unthrottle _all_ local data streams (for when sends
2721 * on the SSH connection itself back up).
2723 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2726 struct ssh_channel *c;
2728 if (enable == ssh->throttled_all)
2730 ssh->throttled_all = enable;
2731 ssh->overall_bufsize = bufsize;
2734 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2736 case CHAN_MAINSESSION:
2738 * This is treated separately, outside the switch.
2742 x11_override_throttle(c->u.x11.s, enable);
2745 /* Agent channels require no buffer management. */
2748 pfd_override_throttle(c->u.pfd.s, enable);
2755 * Username and password input, abstracted off into routines
2756 * reusable in several places - even between SSH-1 and SSH-2.
2759 /* Set up a username or password input loop on a given buffer. */
2760 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2762 ssh->userpass_input_buffer = buffer;
2763 ssh->userpass_input_buflen = buflen;
2764 ssh->userpass_input_bufpos = 0;
2765 ssh->userpass_input_echo = echo;
2769 * Process some terminal data in the course of username/password
2770 * input. Returns >0 for success (line of input returned in
2771 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2772 * for inconclusive (keep waiting for more input please).
2774 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2779 switch (c = *in++) {
2782 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2783 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2788 if (ssh->userpass_input_bufpos > 0) {
2789 if (ssh->userpass_input_echo)
2790 c_write_str(ssh, "\b \b");
2791 ssh->userpass_input_bufpos--;
2796 while (ssh->userpass_input_bufpos > 0) {
2797 if (ssh->userpass_input_echo)
2798 c_write_str(ssh, "\b \b");
2799 ssh->userpass_input_bufpos--;
2808 * This simplistic check for printability is disabled
2809 * when we're doing password input, because some people
2810 * have control characters in their passwords.o
2812 if ((!ssh->userpass_input_echo ||
2813 (c >= ' ' && c <= '~') ||
2814 ((unsigned char) c >= 160))
2815 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2816 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2817 if (ssh->userpass_input_echo)
2818 c_write(ssh, &c, 1);
2826 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2828 Ssh ssh = (Ssh) sshv;
2830 ssh->agent_response = reply;
2831 ssh->agent_response_len = replylen;
2833 if (ssh->version == 1)
2834 do_ssh1_login(ssh, NULL, -1, NULL);
2836 do_ssh2_authconn(ssh, NULL, -1, NULL);
2839 static void ssh_dialog_callback(void *sshv, int ret)
2841 Ssh ssh = (Ssh) sshv;
2843 ssh->user_response = ret;
2845 if (ssh->version == 1)
2846 do_ssh1_login(ssh, NULL, -1, NULL);
2848 do_ssh2_transport(ssh, NULL, -1, NULL);
2851 * This may have unfrozen the SSH connection, so do a
2854 ssh_process_queued_incoming_data(ssh);
2857 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2859 struct ssh_channel *c = (struct ssh_channel *)cv;
2861 void *sentreply = reply;
2864 /* Fake SSH_AGENT_FAILURE. */
2865 sentreply = "\0\0\0\1\5";
2868 if (ssh->version == 2) {
2869 ssh2_add_channel_data(c, sentreply, replylen);
2872 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2873 PKT_INT, c->remoteid,
2876 PKT_DATA, sentreply, replylen,
2885 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2886 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2887 * => log `wire_reason'.
2889 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2890 int code, int clean_exit)
2894 client_reason = wire_reason;
2896 error = dupprintf("Disconnected: %s", client_reason);
2898 error = dupstr("Disconnected");
2900 if (ssh->version == 1) {
2901 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2903 } else if (ssh->version == 2) {
2904 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2905 ssh2_pkt_adduint32(pktout, code);
2906 ssh2_pkt_addstring(pktout, wire_reason);
2907 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2908 ssh2_pkt_send_noqueue(ssh, pktout);
2911 ssh->close_expected = TRUE;
2912 ssh->clean_exit = clean_exit;
2913 ssh_closing((Plug)ssh, error, 0, 0);
2918 * Handle the key exchange and user authentication phases.
2920 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2921 struct Packet *pktin)
2924 unsigned char cookie[8], *ptr;
2925 struct RSAKey servkey, hostkey;
2926 struct MD5Context md5c;
2927 struct do_ssh1_login_state {
2929 unsigned char *rsabuf, *keystr1, *keystr2;
2930 unsigned long supported_ciphers_mask, supported_auths_mask;
2931 int tried_publickey, tried_agent;
2932 int tis_auth_refused, ccard_auth_refused;
2933 unsigned char session_id[16];
2936 void *publickey_blob;
2937 int publickey_bloblen;
2943 unsigned char request[5], *response, *p;
2953 crState(do_ssh1_login_state);
2955 crBegin(ssh->do_ssh1_login_crstate);
2960 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2961 bombout(("Public key packet not received"));
2965 logevent("Received public keys");
2967 ptr = ssh_pkt_getdata(pktin, 8);
2969 bombout(("SSH-1 public key packet stopped before random cookie"));
2972 memcpy(cookie, ptr, 8);
2974 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2975 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2976 bombout(("Failed to read SSH-1 public keys from public key packet"));
2981 * Log the host key fingerprint.
2985 logevent("Host key fingerprint is:");
2986 strcpy(logmsg, " ");
2987 hostkey.comment = NULL;
2988 rsa_fingerprint(logmsg + strlen(logmsg),
2989 sizeof(logmsg) - strlen(logmsg), &hostkey);
2993 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2994 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2995 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2997 ssh->v1_local_protoflags =
2998 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2999 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3002 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3003 MD5Update(&md5c, s->keystr1, servkey.bytes);
3004 MD5Update(&md5c, cookie, 8);
3005 MD5Final(s->session_id, &md5c);
3007 for (i = 0; i < 32; i++)
3008 ssh->session_key[i] = random_byte();
3011 * Verify that the `bits' and `bytes' parameters match.
3013 if (hostkey.bits > hostkey.bytes * 8 ||
3014 servkey.bits > servkey.bytes * 8) {
3015 bombout(("SSH-1 public keys were badly formatted"));
3019 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3021 s->rsabuf = snewn(s->len, unsigned char);
3024 * Verify the host key.
3028 * First format the key into a string.
3030 int len = rsastr_len(&hostkey);
3031 char fingerprint[100];
3032 char *keystr = snewn(len, char);
3033 rsastr_fmt(keystr, &hostkey);
3034 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3036 ssh_set_frozen(ssh, 1);
3037 s->dlgret = verify_ssh_host_key(ssh->frontend,
3038 ssh->savedhost, ssh->savedport,
3039 "rsa", keystr, fingerprint,
3040 ssh_dialog_callback, ssh);
3042 if (s->dlgret < 0) {
3046 bombout(("Unexpected data from server while waiting"
3047 " for user host key response"));
3050 } while (pktin || inlen > 0);
3051 s->dlgret = ssh->user_response;
3053 ssh_set_frozen(ssh, 0);
3055 if (s->dlgret == 0) {
3056 ssh_disconnect(ssh, "User aborted at host key verification",
3062 for (i = 0; i < 32; i++) {
3063 s->rsabuf[i] = ssh->session_key[i];
3065 s->rsabuf[i] ^= s->session_id[i];
3068 if (hostkey.bytes > servkey.bytes) {
3069 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3071 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3073 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3075 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3078 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3082 logevent("Encrypted session key");
3085 int cipher_chosen = 0, warn = 0;
3086 char *cipher_string = NULL;
3088 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3089 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3090 if (next_cipher == CIPHER_WARN) {
3091 /* If/when we choose a cipher, warn about it */
3093 } else if (next_cipher == CIPHER_AES) {
3094 /* XXX Probably don't need to mention this. */
3095 logevent("AES not supported in SSH-1, skipping");
3097 switch (next_cipher) {
3098 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3099 cipher_string = "3DES"; break;
3100 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3101 cipher_string = "Blowfish"; break;
3102 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3103 cipher_string = "single-DES"; break;
3105 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3109 if (!cipher_chosen) {
3110 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3111 bombout(("Server violates SSH-1 protocol by not "
3112 "supporting 3DES encryption"));
3114 /* shouldn't happen */
3115 bombout(("No supported ciphers found"));
3119 /* Warn about chosen cipher if necessary. */
3121 ssh_set_frozen(ssh, 1);
3122 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3123 ssh_dialog_callback, ssh);
3124 if (s->dlgret < 0) {
3128 bombout(("Unexpected data from server while waiting"
3129 " for user response"));
3132 } while (pktin || inlen > 0);
3133 s->dlgret = ssh->user_response;
3135 ssh_set_frozen(ssh, 0);
3136 if (s->dlgret == 0) {
3137 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3144 switch (s->cipher_type) {
3145 case SSH_CIPHER_3DES:
3146 logevent("Using 3DES encryption");
3148 case SSH_CIPHER_DES:
3149 logevent("Using single-DES encryption");
3151 case SSH_CIPHER_BLOWFISH:
3152 logevent("Using Blowfish encryption");
3156 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3157 PKT_CHAR, s->cipher_type,
3158 PKT_DATA, cookie, 8,
3159 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3160 PKT_DATA, s->rsabuf, s->len,
3161 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3163 logevent("Trying to enable encryption...");
3167 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3168 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3170 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3171 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3172 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3174 ssh->crcda_ctx = crcda_make_context();
3175 logevent("Installing CRC compensation attack detector");
3177 if (servkey.modulus) {
3178 sfree(servkey.modulus);
3179 servkey.modulus = NULL;
3181 if (servkey.exponent) {
3182 sfree(servkey.exponent);
3183 servkey.exponent = NULL;
3185 if (hostkey.modulus) {
3186 sfree(hostkey.modulus);
3187 hostkey.modulus = NULL;
3189 if (hostkey.exponent) {
3190 sfree(hostkey.exponent);
3191 hostkey.exponent = NULL;
3195 if (pktin->type != SSH1_SMSG_SUCCESS) {
3196 bombout(("Encryption not successfully enabled"));
3200 logevent("Successfully started encryption");
3204 if (!*ssh->cfg.username) {
3205 if (ssh_get_line && !ssh_getline_pw_only) {
3206 if (!ssh_get_line("login as: ",
3207 s->username, sizeof(s->username), FALSE)) {
3209 * get_line failed to get a username.
3212 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3216 int ret; /* need not be kept over crReturn */
3217 c_write_str(ssh, "login as: ");
3220 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3222 crWaitUntil(!pktin);
3223 ret = process_userpass_input(ssh, in, inlen);
3227 c_write_str(ssh, "\r\n");
3230 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3231 s->username[sizeof(s->username)-1] = '\0';
3234 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3236 char userlog[22 + sizeof(s->username)];
3237 sprintf(userlog, "Sent username \"%s\"", s->username);
3239 if (flags & FLAG_INTERACTIVE &&
3240 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3241 strcat(userlog, "\r\n");
3242 c_write_str(ssh, userlog);
3249 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3250 /* We must not attempt PK auth. Pretend we've already tried it. */
3251 s->tried_publickey = s->tried_agent = 1;
3253 s->tried_publickey = s->tried_agent = 0;
3255 s->tis_auth_refused = s->ccard_auth_refused = 0;
3256 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3257 if (!filename_is_null(ssh->cfg.keyfile)) {
3258 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3259 &s->publickey_blob, &s->publickey_bloblen, NULL))
3260 s->publickey_blob = NULL;
3262 s->publickey_blob = NULL;
3264 while (pktin->type == SSH1_SMSG_FAILURE) {
3265 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3267 if (agent_exists() && !s->tried_agent) {
3269 * Attempt RSA authentication using Pageant.
3275 logevent("Pageant is running. Requesting keys.");
3277 /* Request the keys held by the agent. */
3278 PUT_32BIT(s->request, 1);
3279 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3280 if (!agent_query(s->request, 5, &r, &s->responselen,
3281 ssh_agent_callback, ssh)) {
3285 bombout(("Unexpected data from server while waiting"
3286 " for agent response"));
3289 } while (pktin || inlen > 0);
3290 r = ssh->agent_response;
3291 s->responselen = ssh->agent_response_len;
3293 s->response = (unsigned char *) r;
3294 if (s->response && s->responselen >= 5 &&
3295 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3296 s->p = s->response + 5;
3297 s->nkeys = GET_32BIT(s->p);
3299 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3300 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3301 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3302 if (s->publickey_blob &&
3303 !memcmp(s->p, s->publickey_blob,
3304 s->publickey_bloblen)) {
3305 logevent("This key matches configured key file");
3306 s->tried_publickey = 1;
3311 do { /* do while (0) to make breaking easy */
3312 n = ssh1_read_bignum
3313 (s->p, s->responselen-(s->p-s->response),
3318 n = ssh1_read_bignum
3319 (s->p, s->responselen-(s->p-s->response),
3324 if (s->responselen - (s->p-s->response) < 4)
3326 s->commentlen = GET_32BIT(s->p);
3328 if (s->responselen - (s->p-s->response) <
3331 s->commentp = (char *)s->p;
3332 s->p += s->commentlen;
3336 logevent("Pageant key list packet was truncated");
3340 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3341 PKT_BIGNUM, s->key.modulus, PKT_END);
3343 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3344 logevent("Key refused");
3347 logevent("Received RSA challenge");
3348 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3349 bombout(("Server's RSA challenge was badly formatted"));
3354 char *agentreq, *q, *ret;
3357 len = 1 + 4; /* message type, bit count */
3358 len += ssh1_bignum_length(s->key.exponent);
3359 len += ssh1_bignum_length(s->key.modulus);
3360 len += ssh1_bignum_length(s->challenge);
3361 len += 16; /* session id */
3362 len += 4; /* response format */
3363 agentreq = snewn(4 + len, char);
3364 PUT_32BIT(agentreq, len);
3366 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3367 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3369 q += ssh1_write_bignum(q, s->key.exponent);
3370 q += ssh1_write_bignum(q, s->key.modulus);
3371 q += ssh1_write_bignum(q, s->challenge);
3372 memcpy(q, s->session_id, 16);
3374 PUT_32BIT(q, 1); /* response format */
3375 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3376 ssh_agent_callback, ssh)) {
3381 bombout(("Unexpected data from server"
3382 " while waiting for agent"
3386 } while (pktin || inlen > 0);
3387 vret = ssh->agent_response;
3388 retlen = ssh->agent_response_len;
3393 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3394 logevent("Sending Pageant's response");
3395 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3396 PKT_DATA, ret + 5, 16,
3400 if (pktin->type == SSH1_SMSG_SUCCESS) {
3402 ("Pageant's response accepted");
3403 if (flags & FLAG_VERBOSE) {
3404 c_write_str(ssh, "Authenticated using"
3406 c_write(ssh, s->commentp,
3408 c_write_str(ssh, "\" from agent\r\n");
3413 ("Pageant's response not accepted");
3416 ("Pageant failed to answer challenge");
3420 logevent("No reply received from Pageant");
3423 freebn(s->key.exponent);
3424 freebn(s->key.modulus);
3425 freebn(s->challenge);
3434 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3435 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3437 if (ssh->cfg.try_tis_auth &&
3438 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3439 !s->tis_auth_refused) {
3440 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3441 logevent("Requested TIS authentication");
3442 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3444 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3445 logevent("TIS authentication declined");
3446 if (flags & FLAG_INTERACTIVE)
3447 c_write_str(ssh, "TIS authentication refused.\r\n");
3448 s->tis_auth_refused = 1;
3454 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3456 bombout(("TIS challenge packet was badly formed"));
3459 c_write_str(ssh, "Using TIS authentication.\r\n");
3460 logevent("Received TIS challenge");
3461 if (challengelen > sizeof(s->prompt) - 1)
3462 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3463 memcpy(s->prompt, challenge, challengelen);
3464 /* Prompt heuristic comes from OpenSSH */
3465 strncpy(s->prompt + challengelen,
3466 memchr(s->prompt, '\n', challengelen) ?
3467 "": "\r\nResponse: ",
3468 (sizeof s->prompt) - challengelen);
3469 s->prompt[(sizeof s->prompt) - 1] = '\0';
3472 if (ssh->cfg.try_tis_auth &&
3473 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3474 !s->ccard_auth_refused) {
3475 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3476 logevent("Requested CryptoCard authentication");
3477 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3479 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3480 logevent("CryptoCard authentication declined");
3481 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3482 s->ccard_auth_refused = 1;
3488 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3490 bombout(("CryptoCard challenge packet was badly formed"));
3493 c_write_str(ssh, "Using CryptoCard authentication.\r\n");
3494 logevent("Received CryptoCard challenge");
3495 if (challengelen > sizeof(s->prompt) - 1)
3496 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3497 memcpy(s->prompt, challenge, challengelen);
3498 strncpy(s->prompt + challengelen,
3499 memchr(s->prompt, '\n', challengelen) ?
3500 "" : "\r\nResponse: ",
3501 sizeof(s->prompt) - challengelen);
3502 s->prompt[sizeof(s->prompt) - 1] = '\0';
3505 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3506 sprintf(s->prompt, "%.90s@%.90s's password: ",
3507 s->username, ssh->savedhost);
3509 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3510 char *comment = NULL;
3512 if (flags & FLAG_VERBOSE)
3513 c_write_str(ssh, "Trying public key authentication.\r\n");
3514 logeventf(ssh, "Trying public key \"%s\"",
3515 filename_to_str(&ssh->cfg.keyfile));
3516 type = key_type(&ssh->cfg.keyfile);
3517 if (type != SSH_KEYTYPE_SSH1) {
3518 char *msg = dupprintf("Key is of wrong type (%s)",
3519 key_type_to_str(type));
3521 c_write_str(ssh, msg);
3522 c_write_str(ssh, "\r\n");
3524 s->tried_publickey = 1;
3527 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3528 if (flags & FLAG_VERBOSE)
3529 c_write_str(ssh, "No passphrase required.\r\n");
3532 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3537 * Show password prompt, having first obtained it via a TIS
3538 * or CryptoCard exchange if we're doing TIS or CryptoCard
3542 if (!ssh_get_line(s->prompt, s->password,
3543 sizeof(s->password), TRUE)) {
3545 * get_line failed to get a password (for example
3546 * because one was supplied on the command line
3547 * which has already failed to work). Terminate.
3549 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, FALSE);
3553 /* Prompt may have come from server. We've munged it a bit, so
3554 * we know it to be zero-terminated at least once. */
3555 int ret; /* need not be saved over crReturn */
3556 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3559 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3561 crWaitUntil(!pktin);
3562 ret = process_userpass_input(ssh, in, inlen);
3566 c_write_str(ssh, "\r\n");
3570 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3572 * Try public key authentication with the specified
3575 s->tried_publickey = 1;
3578 const char *error = NULL;
3579 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3582 c_write_str(ssh, "Couldn't load private key from ");
3583 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3584 c_write_str(ssh, " (");
3585 c_write_str(ssh, error);
3586 c_write_str(ssh, ").\r\n");
3587 continue; /* go and try password */
3590 c_write_str(ssh, "Wrong passphrase.\r\n");
3591 s->tried_publickey = 0;
3592 continue; /* try again */
3597 * Send a public key attempt.
3599 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3600 PKT_BIGNUM, s->key.modulus, PKT_END);
3603 if (pktin->type == SSH1_SMSG_FAILURE) {
3604 c_write_str(ssh, "Server refused our public key.\r\n");
3605 continue; /* go and try password */
3607 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3608 bombout(("Bizarre response to offer of public key"));
3614 unsigned char buffer[32];
3615 Bignum challenge, response;
3617 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3618 bombout(("Server's RSA challenge was badly formatted"));
3621 response = rsadecrypt(challenge, &s->key);
3622 freebn(s->key.private_exponent);/* burn the evidence */
3624 for (i = 0; i < 32; i++) {
3625 buffer[i] = bignum_byte(response, 31 - i);
3629 MD5Update(&md5c, buffer, 32);
3630 MD5Update(&md5c, s->session_id, 16);
3631 MD5Final(buffer, &md5c);
3633 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3634 PKT_DATA, buffer, 16, PKT_END);
3641 if (pktin->type == SSH1_SMSG_FAILURE) {
3642 if (flags & FLAG_VERBOSE)
3643 c_write_str(ssh, "Failed to authenticate with"
3644 " our public key.\r\n");
3645 continue; /* go and try password */
3646 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3647 bombout(("Bizarre response to RSA authentication response"));
3651 break; /* we're through! */
3653 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3655 * Defence against traffic analysis: we send a
3656 * whole bunch of packets containing strings of
3657 * different lengths. One of these strings is the
3658 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3659 * The others are all random data in
3660 * SSH1_MSG_IGNORE packets. This way a passive
3661 * listener can't tell which is the password, and
3662 * hence can't deduce the password length.
3664 * Anybody with a password length greater than 16
3665 * bytes is going to have enough entropy in their
3666 * password that a listener won't find it _that_
3667 * much help to know how long it is. So what we'll
3670 * - if password length < 16, we send 15 packets
3671 * containing string lengths 1 through 15
3673 * - otherwise, we let N be the nearest multiple
3674 * of 8 below the password length, and send 8
3675 * packets containing string lengths N through
3676 * N+7. This won't obscure the order of
3677 * magnitude of the password length, but it will
3678 * introduce a bit of extra uncertainty.
3680 * A few servers (the old 1.2.18 through 1.2.22)
3681 * can't deal with SSH1_MSG_IGNORE. For these
3682 * servers, we need an alternative defence. We make
3683 * use of the fact that the password is interpreted
3684 * as a C string: so we can append a NUL, then some
3687 * One server (a Cisco one) can deal with neither
3688 * SSH1_MSG_IGNORE _nor_ a padded password string.
3689 * For this server we are left with no defences
3690 * against password length sniffing.
3692 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3694 * The server can deal with SSH1_MSG_IGNORE, so
3695 * we can use the primary defence.
3697 int bottom, top, pwlen, i;
3700 pwlen = strlen(s->password);
3702 bottom = 0; /* zero length passwords are OK! :-) */
3705 bottom = pwlen & ~7;
3709 assert(pwlen >= bottom && pwlen <= top);
3711 randomstr = snewn(top + 1, char);
3713 for (i = bottom; i <= top; i++) {
3715 defer_packet(ssh, s->pwpkt_type,
3716 PKTT_PASSWORD, PKT_STR, s->password,
3717 PKTT_OTHER, PKT_END);
3719 for (j = 0; j < i; j++) {
3721 randomstr[j] = random_byte();
3722 } while (randomstr[j] == '\0');
3724 randomstr[i] = '\0';
3725 defer_packet(ssh, SSH1_MSG_IGNORE,
3726 PKT_STR, randomstr, PKT_END);
3729 logevent("Sending password with camouflage packets");
3730 ssh_pkt_defersend(ssh);
3733 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3735 * The server can't deal with SSH1_MSG_IGNORE
3736 * but can deal with padded passwords, so we
3737 * can use the secondary defence.
3743 len = strlen(s->password);
3744 if (len < sizeof(string)) {
3746 strcpy(string, s->password);
3747 len++; /* cover the zero byte */
3748 while (len < sizeof(string)) {
3749 string[len++] = (char) random_byte();
3754 logevent("Sending length-padded password");
3755 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3756 PKT_INT, len, PKT_DATA, ss, len,
3757 PKTT_OTHER, PKT_END);
3760 * The server has _both_
3761 * BUG_CHOKES_ON_SSH1_IGNORE and
3762 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3763 * therefore nothing we can do.
3766 len = strlen(s->password);
3767 logevent("Sending unpadded password");
3768 send_packet(ssh, s->pwpkt_type,
3769 PKTT_PASSWORD, PKT_INT, len,
3770 PKT_DATA, s->password, len,
3771 PKTT_OTHER, PKT_END);
3774 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3775 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3778 logevent("Sent password");
3779 memset(s->password, 0, strlen(s->password));
3781 if (pktin->type == SSH1_SMSG_FAILURE) {
3782 if (flags & FLAG_VERBOSE)
3783 c_write_str(ssh, "Access denied\r\n");
3784 logevent("Authentication refused");
3785 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3786 bombout(("Strange packet received, type %d", pktin->type));
3791 logevent("Authentication successful");
3796 void sshfwd_close(struct ssh_channel *c)
3800 if (ssh->state == SSH_STATE_CLOSED)
3803 if (c && !c->closes) {
3805 * If halfopen is true, we have sent
3806 * CHANNEL_OPEN for this channel, but it hasn't even been
3807 * acknowledged by the server. So we must set a close flag
3808 * on it now, and then when the server acks the channel
3809 * open, we can close it then.
3812 if (ssh->version == 1) {
3813 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3816 struct Packet *pktout;
3817 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3818 ssh2_pkt_adduint32(pktout, c->remoteid);
3819 ssh2_pkt_send(ssh, pktout);
3822 c->closes = 1; /* sent MSG_CLOSE */
3823 if (c->type == CHAN_X11) {
3825 logevent("Forwarded X11 connection terminated");
3826 } else if (c->type == CHAN_SOCKDATA ||
3827 c->type == CHAN_SOCKDATA_DORMANT) {
3829 logevent("Forwarded port closed");
3834 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3838 if (ssh->state == SSH_STATE_CLOSED)
3841 if (ssh->version == 1) {
3842 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3843 PKT_INT, c->remoteid,
3845 PKT_INT, len, PKT_DATA, buf, len,
3846 PKTT_OTHER, PKT_END);
3848 * In SSH-1 we can return 0 here - implying that forwarded
3849 * connections are never individually throttled - because
3850 * the only circumstance that can cause throttling will be
3851 * the whole SSH connection backing up, in which case
3852 * _everything_ will be throttled as a whole.
3856 ssh2_add_channel_data(c, buf, len);
3857 return ssh2_try_send(c);
3861 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3865 if (ssh->state == SSH_STATE_CLOSED)
3868 if (ssh->version == 1) {
3869 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3870 c->v.v1.throttling = 0;
3871 ssh1_throttle(ssh, -1);
3874 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3878 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3880 struct queued_handler *qh = ssh->qhead;
3884 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3887 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3888 ssh->packet_dispatch[qh->msg1] = NULL;
3891 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3892 ssh->packet_dispatch[qh->msg2] = NULL;
3896 ssh->qhead = qh->next;
3898 if (ssh->qhead->msg1 > 0) {
3899 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3900 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3902 if (ssh->qhead->msg2 > 0) {
3903 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3904 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3907 ssh->qhead = ssh->qtail = NULL;
3908 ssh->packet_dispatch[pktin->type] = NULL;
3911 qh->handler(ssh, pktin, qh->ctx);
3916 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3917 chandler_fn_t handler, void *ctx)
3919 struct queued_handler *qh;
3921 qh = snew(struct queued_handler);
3924 qh->handler = handler;
3928 if (ssh->qtail == NULL) {
3932 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3933 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3936 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3937 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3940 ssh->qtail->next = qh;
3945 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3947 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3949 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3950 SSH2_MSG_REQUEST_SUCCESS)) {
3951 logeventf(ssh, "Remote port forwarding from %s enabled",
3954 logeventf(ssh, "Remote port forwarding from %s refused",
3957 rpf = del234(ssh->rportfwds, pf);
3963 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3965 const char *portfwd_strptr = cfg->portfwd;
3966 struct ssh_portfwd *epf;
3969 if (!ssh->portfwds) {
3970 ssh->portfwds = newtree234(ssh_portcmp);
3973 * Go through the existing port forwardings and tag them
3974 * with status==DESTROY. Any that we want to keep will be
3975 * re-enabled (status==KEEP) as we go through the
3976 * configuration and find out which bits are the same as
3979 struct ssh_portfwd *epf;
3981 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3982 epf->status = DESTROY;
3985 while (*portfwd_strptr) {
3986 char address_family, type;
3987 int sport,dport,sserv,dserv;
3988 char sports[256], dports[256], saddr[256], host[256];
3991 address_family = 'A';
3993 if (*portfwd_strptr == 'A' ||
3994 *portfwd_strptr == '4' ||
3995 *portfwd_strptr == '6')
3996 address_family = *portfwd_strptr++;
3997 if (*portfwd_strptr == 'L' ||
3998 *portfwd_strptr == 'R' ||
3999 *portfwd_strptr == 'D')
4000 type = *portfwd_strptr++;
4005 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4006 if (*portfwd_strptr == ':') {
4008 * We've seen a colon in the middle of the
4009 * source port number. This means that
4010 * everything we've seen until now is the
4011 * source _address_, so we'll move it into
4012 * saddr and start sports from the beginning
4017 if (ssh->version == 1 && type == 'R') {
4018 logeventf(ssh, "SSH-1 cannot handle remote source address "
4019 "spec \"%s\"; ignoring", sports);
4021 strcpy(saddr, sports);
4024 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4028 if (*portfwd_strptr == '\t')
4031 while (*portfwd_strptr && *portfwd_strptr != ':') {
4032 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4035 if (*portfwd_strptr == ':')
4038 while (*portfwd_strptr) {
4039 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4043 dport = atoi(dports);
4047 dport = net_service_lookup(dports);
4049 logeventf(ssh, "Service lookup failed for destination"
4050 " port \"%s\"", dports);
4054 while (*portfwd_strptr) portfwd_strptr++;
4058 portfwd_strptr++; /* eat the NUL and move to next one */
4060 sport = atoi(sports);
4064 sport = net_service_lookup(sports);
4066 logeventf(ssh, "Service lookup failed for source"
4067 " port \"%s\"", sports);
4070 if (sport && dport) {
4071 /* Set up a description of the source port. */
4072 struct ssh_portfwd *pfrec, *epfrec;
4074 pfrec = snew(struct ssh_portfwd);
4076 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4077 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4078 pfrec->sport = sport;
4079 pfrec->daddr = *host ? dupstr(host) : NULL;
4080 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4081 pfrec->dport = dport;
4082 pfrec->local = NULL;
4083 pfrec->remote = NULL;
4084 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4085 address_family == '6' ? ADDRTYPE_IPV6 :
4088 epfrec = add234(ssh->portfwds, pfrec);
4089 if (epfrec != pfrec) {
4091 * We already have a port forwarding with precisely
4092 * these parameters. Hence, no need to do anything;
4093 * simply tag the existing one as KEEP.
4095 epfrec->status = KEEP;
4096 free_portfwd(pfrec);
4098 pfrec->status = CREATE;
4104 * Now go through and destroy any port forwardings which were
4107 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4108 if (epf->status == DESTROY) {
4111 message = dupprintf("%s port forwarding from %s%s%d",
4112 epf->type == 'L' ? "local" :
4113 epf->type == 'R' ? "remote" : "dynamic",
4114 epf->saddr ? epf->saddr : "",
4115 epf->saddr ? ":" : "",
4118 if (epf->type != 'D') {
4119 char *msg2 = dupprintf("%s to %s:%d", message,
4120 epf->daddr, epf->dport);
4125 logeventf(ssh, "Cancelling %s", message);
4129 struct ssh_rportfwd *rpf = epf->remote;
4130 struct Packet *pktout;
4133 * Cancel the port forwarding at the server
4136 if (ssh->version == 1) {
4138 * We cannot cancel listening ports on the
4139 * server side in SSH-1! There's no message
4140 * to support it. Instead, we simply remove
4141 * the rportfwd record from the local end
4142 * so that any connections the server tries
4143 * to make on it are rejected.
4146 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4147 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4148 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4150 ssh2_pkt_addstring(pktout, epf->saddr);
4151 } else if (ssh->cfg.rport_acceptall) {
4152 /* XXX: ssh->cfg.rport_acceptall may not represent
4153 * what was used to open the original connection,
4154 * since it's reconfigurable. */
4155 ssh2_pkt_addstring(pktout, "0.0.0.0");
4157 ssh2_pkt_addstring(pktout, "127.0.0.1");
4159 ssh2_pkt_adduint32(pktout, epf->sport);
4160 ssh2_pkt_send(ssh, pktout);
4163 del234(ssh->rportfwds, rpf);
4165 } else if (epf->local) {
4166 pfd_terminate(epf->local);
4169 delpos234(ssh->portfwds, i);
4171 i--; /* so we don't skip one in the list */
4175 * And finally, set up any new port forwardings (status==CREATE).
4177 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4178 if (epf->status == CREATE) {
4179 char *sportdesc, *dportdesc;
4180 sportdesc = dupprintf("%s%s%s%s%d%s",
4181 epf->saddr ? epf->saddr : "",
4182 epf->saddr ? ":" : "",
4183 epf->sserv ? epf->sserv : "",
4184 epf->sserv ? "(" : "",
4186 epf->sserv ? ")" : "");
4187 if (epf->type == 'D') {
4190 dportdesc = dupprintf("%s:%s%s%d%s",
4192 epf->dserv ? epf->dserv : "",
4193 epf->dserv ? "(" : "",
4195 epf->dserv ? ")" : "");
4198 if (epf->type == 'L') {
4199 const char *err = pfd_addforward(epf->daddr, epf->dport,
4200 epf->saddr, epf->sport,
4203 epf->addressfamily);
4205 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4206 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4207 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4208 sportdesc, dportdesc,
4209 err ? " failed: " : "", err ? err : "");
4210 } else if (epf->type == 'D') {
4211 const char *err = pfd_addforward(NULL, -1,
4212 epf->saddr, epf->sport,
4215 epf->addressfamily);
4217 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4218 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4219 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4221 err ? " failed: " : "", err ? err : "");
4223 struct ssh_rportfwd *pf;
4226 * Ensure the remote port forwardings tree exists.
4228 if (!ssh->rportfwds) {
4229 if (ssh->version == 1)
4230 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4232 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4235 pf = snew(struct ssh_rportfwd);
4236 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4237 pf->dhost[lenof(pf->dhost)-1] = '\0';
4238 pf->dport = epf->dport;
4239 pf->sport = epf->sport;
4240 if (add234(ssh->rportfwds, pf) != pf) {
4241 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4242 epf->daddr, epf->dport);
4245 logeventf(ssh, "Requesting remote port %s"
4246 " forward to %s", sportdesc, dportdesc);
4248 pf->sportdesc = sportdesc;
4253 if (ssh->version == 1) {
4254 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4255 PKT_INT, epf->sport,
4256 PKT_STR, epf->daddr,
4257 PKT_INT, epf->dport,
4259 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4261 ssh_rportfwd_succfail, pf);
4263 struct Packet *pktout;
4264 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4265 ssh2_pkt_addstring(pktout, "tcpip-forward");
4266 ssh2_pkt_addbool(pktout, 1);/* want reply */
4268 ssh2_pkt_addstring(pktout, epf->saddr);
4269 } else if (cfg->rport_acceptall) {
4270 ssh2_pkt_addstring(pktout, "0.0.0.0");
4272 ssh2_pkt_addstring(pktout, "127.0.0.1");
4274 ssh2_pkt_adduint32(pktout, epf->sport);
4275 ssh2_pkt_send(ssh, pktout);
4277 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4278 SSH2_MSG_REQUEST_FAILURE,
4279 ssh_rportfwd_succfail, pf);
4288 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4291 int stringlen, bufsize;
4293 ssh_pkt_getstring(pktin, &string, &stringlen);
4294 if (string == NULL) {
4295 bombout(("Incoming terminal data packet was badly formed"));
4299 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4301 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4302 ssh->v1_stdout_throttling = 1;
4303 ssh1_throttle(ssh, +1);
4307 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4309 /* Remote side is trying to open a channel to talk to our
4310 * X-Server. Give them back a local channel number. */
4311 struct ssh_channel *c;
4312 int remoteid = ssh_pkt_getuint32(pktin);
4314 logevent("Received X11 connect request");
4315 /* Refuse if X11 forwarding is disabled. */
4316 if (!ssh->X11_fwd_enabled) {
4317 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4318 PKT_INT, remoteid, PKT_END);
4319 logevent("Rejected X11 connect request");
4321 c = snew(struct ssh_channel);
4324 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4325 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4326 logevent("Opening X11 forward connection failed");
4328 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4329 PKT_INT, remoteid, PKT_END);
4332 ("Opening X11 forward connection succeeded");
4333 c->remoteid = remoteid;
4334 c->halfopen = FALSE;
4335 c->localid = alloc_channel_id(ssh);
4337 c->v.v1.throttling = 0;
4338 c->type = CHAN_X11; /* identify channel type */
4339 add234(ssh->channels, c);
4340 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4341 PKT_INT, c->remoteid, PKT_INT,
4342 c->localid, PKT_END);
4343 logevent("Opened X11 forward channel");
4348 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4350 /* Remote side is trying to open a channel to talk to our
4351 * agent. Give them back a local channel number. */
4352 struct ssh_channel *c;
4353 int remoteid = ssh_pkt_getuint32(pktin);
4355 /* Refuse if agent forwarding is disabled. */
4356 if (!ssh->agentfwd_enabled) {
4357 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4358 PKT_INT, remoteid, PKT_END);
4360 c = snew(struct ssh_channel);
4362 c->remoteid = remoteid;
4363 c->halfopen = FALSE;
4364 c->localid = alloc_channel_id(ssh);
4366 c->v.v1.throttling = 0;
4367 c->type = CHAN_AGENT; /* identify channel type */
4368 c->u.a.lensofar = 0;
4369 add234(ssh->channels, c);
4370 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4371 PKT_INT, c->remoteid, PKT_INT, c->localid,
4376 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4378 /* Remote side is trying to open a channel to talk to a
4379 * forwarded port. Give them back a local channel number. */
4380 struct ssh_channel *c;
4381 struct ssh_rportfwd pf, *pfp;
4386 c = snew(struct ssh_channel);
4389 remoteid = ssh_pkt_getuint32(pktin);
4390 ssh_pkt_getstring(pktin, &host, &hostsize);
4391 port = ssh_pkt_getuint32(pktin);
4393 if (hostsize >= lenof(pf.dhost))
4394 hostsize = lenof(pf.dhost)-1;
4395 memcpy(pf.dhost, host, hostsize);
4396 pf.dhost[hostsize] = '\0';
4398 pfp = find234(ssh->rportfwds, &pf, NULL);
4401 logeventf(ssh, "Rejected remote port open request for %s:%d",
4403 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4404 PKT_INT, remoteid, PKT_END);
4406 logeventf(ssh, "Received remote port open request for %s:%d",
4408 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4409 c, &ssh->cfg, pfp->pfrec->addressfamily);
4411 logeventf(ssh, "Port open failed: %s", e);
4413 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4414 PKT_INT, remoteid, PKT_END);
4416 c->remoteid = remoteid;
4417 c->halfopen = FALSE;
4418 c->localid = alloc_channel_id(ssh);
4420 c->v.v1.throttling = 0;
4421 c->type = CHAN_SOCKDATA; /* identify channel type */
4422 add234(ssh->channels, c);
4423 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4424 PKT_INT, c->remoteid, PKT_INT,
4425 c->localid, PKT_END);
4426 logevent("Forwarded port opened successfully");
4431 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4433 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4434 unsigned int localid = ssh_pkt_getuint32(pktin);
4435 struct ssh_channel *c;
4437 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4438 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4439 c->remoteid = localid;
4440 c->halfopen = FALSE;
4441 c->type = CHAN_SOCKDATA;
4442 c->v.v1.throttling = 0;
4443 pfd_confirm(c->u.pfd.s);
4446 if (c && c->closes) {
4448 * We have a pending close on this channel,
4449 * which we decided on before the server acked
4450 * the channel open. So now we know the
4451 * remoteid, we can close it again.
4453 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4454 PKT_INT, c->remoteid, PKT_END);
4458 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4460 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4461 struct ssh_channel *c;
4463 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4464 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4465 logevent("Forwarded connection refused by server");
4466 pfd_close(c->u.pfd.s);
4467 del234(ssh->channels, c);
4472 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4474 /* Remote side closes a channel. */
4475 unsigned i = ssh_pkt_getuint32(pktin);
4476 struct ssh_channel *c;
4477 c = find234(ssh->channels, &i, ssh_channelfind);
4478 if (c && !c->halfopen) {
4481 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4483 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4484 logevent("Forwarded X11 connection terminated");
4485 assert(c->u.x11.s != NULL);
4486 x11_close(c->u.x11.s);
4489 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4490 logevent("Forwarded port closed");
4491 assert(c->u.pfd.s != NULL);
4492 pfd_close(c->u.pfd.s);
4496 c->closes |= (closetype << 2); /* seen this message */
4497 if (!(c->closes & closetype)) {
4498 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4500 c->closes |= closetype; /* sent it too */
4503 if (c->closes == 15) {
4504 del234(ssh->channels, c);
4508 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4509 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4510 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4515 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4517 /* Data sent down one of our channels. */
4518 int i = ssh_pkt_getuint32(pktin);
4521 struct ssh_channel *c;
4523 ssh_pkt_getstring(pktin, &p, &len);
4525 c = find234(ssh->channels, &i, ssh_channelfind);
4530 bufsize = x11_send(c->u.x11.s, p, len);
4533 bufsize = pfd_send(c->u.pfd.s, p, len);
4536 /* Data for an agent message. Buffer it. */
4538 if (c->u.a.lensofar < 4) {
4539 unsigned int l = min(4 - c->u.a.lensofar, len);
4540 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4544 c->u.a.lensofar += l;
4546 if (c->u.a.lensofar == 4) {
4548 4 + GET_32BIT(c->u.a.msglen);
4549 c->u.a.message = snewn(c->u.a.totallen,
4551 memcpy(c->u.a.message, c->u.a.msglen, 4);
4553 if (c->u.a.lensofar >= 4 && len > 0) {
4555 min(c->u.a.totallen - c->u.a.lensofar,
4557 memcpy(c->u.a.message + c->u.a.lensofar, p,
4561 c->u.a.lensofar += l;
4563 if (c->u.a.lensofar == c->u.a.totallen) {
4566 if (agent_query(c->u.a.message,
4569 ssh_agentf_callback, c))
4570 ssh_agentf_callback(c, reply, replylen);
4571 sfree(c->u.a.message);
4572 c->u.a.lensofar = 0;
4575 bufsize = 0; /* agent channels never back up */
4578 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4579 c->v.v1.throttling = 1;
4580 ssh1_throttle(ssh, +1);
4585 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4587 ssh->exitcode = ssh_pkt_getuint32(pktin);
4588 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4589 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4591 * In case `helpful' firewalls or proxies tack
4592 * extra human-readable text on the end of the
4593 * session which we might mistake for another
4594 * encrypted packet, we close the session once
4595 * we've sent EXIT_CONFIRMATION.
4597 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4600 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4601 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4603 struct Packet *pktout = (struct Packet *)data;
4605 unsigned int arg = 0;
4606 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4607 if (i == lenof(ssh_ttymodes)) return;
4608 switch (ssh_ttymodes[i].type) {
4610 arg = ssh_tty_parse_specchar(val);
4613 arg = ssh_tty_parse_boolean(val);
4616 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4617 ssh2_pkt_addbyte(pktout, arg);
4621 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4622 struct Packet *pktin)
4624 crBegin(ssh->do_ssh1_connection_crstate);
4626 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4627 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4628 ssh1_smsg_stdout_stderr_data;
4630 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4631 ssh1_msg_channel_open_confirmation;
4632 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4633 ssh1_msg_channel_open_failure;
4634 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4635 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4636 ssh1_msg_channel_close;
4637 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4638 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4640 if (ssh->cfg.agentfwd && agent_exists()) {
4641 logevent("Requesting agent forwarding");
4642 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4646 if (pktin->type != SSH1_SMSG_SUCCESS
4647 && pktin->type != SSH1_SMSG_FAILURE) {
4648 bombout(("Protocol confusion"));
4650 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4651 logevent("Agent forwarding refused");
4653 logevent("Agent forwarding enabled");
4654 ssh->agentfwd_enabled = TRUE;
4655 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4659 if (ssh->cfg.x11_forward) {
4660 char proto[20], data[64];
4661 logevent("Requesting X11 forwarding");
4662 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4663 data, sizeof(data), ssh->cfg.x11_auth);
4664 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4666 * Note that while we blank the X authentication data here, we don't
4667 * take any special action to blank the start of an X11 channel,
4668 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4669 * without having session blanking enabled is likely to leak your
4670 * cookie into the log.
4672 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4673 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4675 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4676 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4679 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4681 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4686 if (pktin->type != SSH1_SMSG_SUCCESS
4687 && pktin->type != SSH1_SMSG_FAILURE) {
4688 bombout(("Protocol confusion"));
4690 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4691 logevent("X11 forwarding refused");
4693 logevent("X11 forwarding enabled");
4694 ssh->X11_fwd_enabled = TRUE;
4695 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4699 ssh_setup_portfwd(ssh, &ssh->cfg);
4700 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4702 if (!ssh->cfg.nopty) {
4704 /* Unpick the terminal-speed string. */
4705 /* XXX perhaps we should allow no speeds to be sent. */
4706 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4707 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4708 /* Send the pty request. */
4709 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4710 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4711 ssh_pkt_adduint32(pkt, ssh->term_height);
4712 ssh_pkt_adduint32(pkt, ssh->term_width);
4713 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4714 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4715 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4716 ssh1_send_ttymode, (void *)pkt);
4717 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4718 ssh_pkt_adduint32(pkt, ssh->ispeed);
4719 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4720 ssh_pkt_adduint32(pkt, ssh->ospeed);
4721 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4723 ssh->state = SSH_STATE_INTERMED;
4727 if (pktin->type != SSH1_SMSG_SUCCESS
4728 && pktin->type != SSH1_SMSG_FAILURE) {
4729 bombout(("Protocol confusion"));
4731 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4732 c_write_str(ssh, "Server refused to allocate pty\r\n");
4733 ssh->editing = ssh->echoing = 1;
4735 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4736 ssh->ospeed, ssh->ispeed);
4738 ssh->editing = ssh->echoing = 1;
4741 if (ssh->cfg.compression) {
4742 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4746 if (pktin->type != SSH1_SMSG_SUCCESS
4747 && pktin->type != SSH1_SMSG_FAILURE) {
4748 bombout(("Protocol confusion"));
4750 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4751 c_write_str(ssh, "Server refused to compress\r\n");
4753 logevent("Started compression");
4754 ssh->v1_compressing = TRUE;
4755 ssh->cs_comp_ctx = zlib_compress_init();
4756 logevent("Initialised zlib (RFC1950) compression");
4757 ssh->sc_comp_ctx = zlib_decompress_init();
4758 logevent("Initialised zlib (RFC1950) decompression");
4762 * Start the shell or command.
4764 * Special case: if the first-choice command is an SSH-2
4765 * subsystem (hence not usable here) and the second choice
4766 * exists, we fall straight back to that.
4769 char *cmd = ssh->cfg.remote_cmd_ptr;
4771 if (!cmd) cmd = ssh->cfg.remote_cmd;
4773 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4774 cmd = ssh->cfg.remote_cmd_ptr2;
4775 ssh->fallback_cmd = TRUE;
4778 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4780 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4781 logevent("Started session");
4784 ssh->state = SSH_STATE_SESSION;
4785 if (ssh->size_needed)
4786 ssh_size(ssh, ssh->term_width, ssh->term_height);
4787 if (ssh->eof_needed)
4788 ssh_special(ssh, TS_EOF);
4791 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4793 ssh->channels = newtree234(ssh_channelcmp);
4797 * By this point, most incoming packets are already being
4798 * handled by the dispatch table, and we need only pay
4799 * attention to the unusual ones.
4804 if (pktin->type == SSH1_SMSG_SUCCESS) {
4805 /* may be from EXEC_SHELL on some servers */
4806 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4807 /* may be from EXEC_SHELL on some servers
4808 * if no pty is available or in other odd cases. Ignore */
4810 bombout(("Strange packet received: type %d", pktin->type));
4815 int len = min(inlen, 512);
4816 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4817 PKT_INT, len, PKT_DATA, in, len,
4818 PKTT_OTHER, PKT_END);
4829 * Handle the top-level SSH-2 protocol.
4831 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4836 ssh_pkt_getstring(pktin, &msg, &msglen);
4837 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4840 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4842 /* log reason code in disconnect message */
4846 ssh_pkt_getstring(pktin, &msg, &msglen);
4847 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4850 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4852 /* Do nothing, because we're ignoring it! Duhh. */
4855 static void ssh1_protocol_setup(Ssh ssh)
4860 * Most messages are handled by the coroutines.
4862 for (i = 0; i < 256; i++)
4863 ssh->packet_dispatch[i] = NULL;
4866 * These special message types we install handlers for.
4868 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4869 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4870 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4873 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4874 struct Packet *pktin)
4876 unsigned char *in=(unsigned char*)vin;
4877 if (ssh->state == SSH_STATE_CLOSED)
4880 if (pktin && ssh->packet_dispatch[pktin->type]) {
4881 ssh->packet_dispatch[pktin->type](ssh, pktin);
4885 if (!ssh->protocol_initial_phase_done) {
4886 if (do_ssh1_login(ssh, in, inlen, pktin))
4887 ssh->protocol_initial_phase_done = TRUE;
4892 do_ssh1_connection(ssh, in, inlen, pktin);
4896 * Utility routine for decoding comma-separated strings in KEXINIT.
4898 static int in_commasep_string(char *needle, char *haystack, int haylen)
4901 if (!needle || !haystack) /* protect against null pointers */
4903 needlen = strlen(needle);
4906 * Is it at the start of the string?
4908 if (haylen >= needlen && /* haystack is long enough */
4909 !memcmp(needle, haystack, needlen) && /* initial match */
4910 (haylen == needlen || haystack[needlen] == ',')
4911 /* either , or EOS follows */
4915 * If not, search for the next comma and resume after that.
4916 * If no comma found, terminate.
4918 while (haylen > 0 && *haystack != ',')
4919 haylen--, haystack++;
4922 haylen--, haystack++; /* skip over comma itself */
4927 * Similar routine for checking whether we have the first string in a list.
4929 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4932 if (!needle || !haystack) /* protect against null pointers */
4934 needlen = strlen(needle);
4936 * Is it at the start of the string?
4938 if (haylen >= needlen && /* haystack is long enough */
4939 !memcmp(needle, haystack, needlen) && /* initial match */
4940 (haylen == needlen || haystack[needlen] == ',')
4941 /* either , or EOS follows */
4949 * SSH-2 key creation method.
4951 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr,
4952 unsigned char *keyspace)
4954 const struct ssh_hash *h = ssh->kex->hash;
4956 /* First hlen bytes. */
4958 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4959 hash_mpint(h, s, K);
4960 h->bytes(s, H, h->hlen);
4961 h->bytes(s, &chr, 1);
4962 h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len);
4963 h->final(s, keyspace);
4964 /* Next hlen bytes. */
4966 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4967 hash_mpint(h, s, K);
4968 h->bytes(s, H, h->hlen);
4969 h->bytes(s, keyspace, h->hlen);
4970 h->final(s, keyspace + h->hlen);
4974 * Handle the SSH-2 transport layer.
4976 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4977 struct Packet *pktin)
4979 unsigned char *in = (unsigned char *)vin;
4980 struct do_ssh2_transport_state {
4981 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4982 Bignum p, g, e, f, K;
4985 int kex_init_value, kex_reply_value;
4986 const struct ssh_mac **maclist;
4988 const struct ssh2_cipher *cscipher_tobe;
4989 const struct ssh2_cipher *sccipher_tobe;
4990 const struct ssh_mac *csmac_tobe;
4991 const struct ssh_mac *scmac_tobe;
4992 const struct ssh_compress *cscomp_tobe;
4993 const struct ssh_compress *sccomp_tobe;
4994 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4995 int hostkeylen, siglen;
4996 void *hkey; /* actual host key */
4997 unsigned char exchange_hash[32];
4998 int n_preferred_kex;
4999 const struct ssh_kexes *preferred_kex[KEX_MAX];
5000 int n_preferred_ciphers;
5001 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5002 const struct ssh_compress *preferred_comp;
5003 int got_session_id, activated_authconn;
5004 struct Packet *pktout;
5009 crState(do_ssh2_transport_state);
5011 crBegin(ssh->do_ssh2_transport_crstate);
5013 s->cscipher_tobe = s->sccipher_tobe = NULL;
5014 s->csmac_tobe = s->scmac_tobe = NULL;
5015 s->cscomp_tobe = s->sccomp_tobe = NULL;
5017 s->got_session_id = s->activated_authconn = FALSE;
5020 * Be prepared to work around the buggy MAC problem.
5022 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5023 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5025 s->maclist = macs, s->nmacs = lenof(macs);
5028 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
5030 int i, j, commalist_started;
5033 * Set up the preferred key exchange. (NULL => warn below here)
5035 s->n_preferred_kex = 0;
5036 for (i = 0; i < KEX_MAX; i++) {
5037 switch (ssh->cfg.ssh_kexlist[i]) {
5039 s->preferred_kex[s->n_preferred_kex++] =
5040 &ssh_diffiehellman_gex;
5043 s->preferred_kex[s->n_preferred_kex++] =
5044 &ssh_diffiehellman_group14;
5047 s->preferred_kex[s->n_preferred_kex++] =
5048 &ssh_diffiehellman_group1;
5051 /* Flag for later. Don't bother if it's the last in
5053 if (i < KEX_MAX - 1) {
5054 s->preferred_kex[s->n_preferred_kex++] = NULL;
5061 * Set up the preferred ciphers. (NULL => warn below here)
5063 s->n_preferred_ciphers = 0;
5064 for (i = 0; i < CIPHER_MAX; i++) {
5065 switch (ssh->cfg.ssh_cipherlist[i]) {
5066 case CIPHER_BLOWFISH:
5067 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5070 if (ssh->cfg.ssh2_des_cbc) {
5071 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5075 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5078 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5080 case CIPHER_ARCFOUR:
5081 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5084 /* Flag for later. Don't bother if it's the last in
5086 if (i < CIPHER_MAX - 1) {
5087 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5094 * Set up preferred compression.
5096 if (ssh->cfg.compression)
5097 s->preferred_comp = &ssh_zlib;
5099 s->preferred_comp = &ssh_comp_none;
5102 * Enable queueing of outgoing auth- or connection-layer
5103 * packets while we are in the middle of a key exchange.
5105 ssh->queueing = TRUE;
5108 * Flag that KEX is in progress.
5110 ssh->kex_in_progress = TRUE;
5113 * Construct and send our key exchange packet.
5115 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5116 for (i = 0; i < 16; i++)
5117 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5118 /* List key exchange algorithms. */
5119 ssh2_pkt_addstring_start(s->pktout);
5120 commalist_started = 0;
5121 for (i = 0; i < s->n_preferred_kex; i++) {
5122 const struct ssh_kexes *k = s->preferred_kex[i];
5123 if (!k) continue; /* warning flag */
5124 for (j = 0; j < k->nkexes; j++) {
5125 if (commalist_started)
5126 ssh2_pkt_addstring_str(s->pktout, ",");
5127 ssh2_pkt_addstring_str(s->pktout, k->list[j]->name);
5128 commalist_started = 1;
5131 /* List server host key algorithms. */
5132 ssh2_pkt_addstring_start(s->pktout);
5133 for (i = 0; i < lenof(hostkey_algs); i++) {
5134 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5135 if (i < lenof(hostkey_algs) - 1)
5136 ssh2_pkt_addstring_str(s->pktout, ",");
5138 /* List client->server encryption algorithms. */
5139 ssh2_pkt_addstring_start(s->pktout);
5140 commalist_started = 0;
5141 for (i = 0; i < s->n_preferred_ciphers; i++) {
5142 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5143 if (!c) continue; /* warning flag */
5144 for (j = 0; j < c->nciphers; j++) {
5145 if (commalist_started)
5146 ssh2_pkt_addstring_str(s->pktout, ",");
5147 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5148 commalist_started = 1;
5151 /* List server->client encryption algorithms. */
5152 ssh2_pkt_addstring_start(s->pktout);
5153 commalist_started = 0;
5154 for (i = 0; i < s->n_preferred_ciphers; i++) {
5155 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5156 if (!c) continue; /* warning flag */
5157 for (j = 0; j < c->nciphers; j++) {
5158 if (commalist_started)
5159 ssh2_pkt_addstring_str(s->pktout, ",");
5160 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5161 commalist_started = 1;
5164 /* List client->server MAC algorithms. */
5165 ssh2_pkt_addstring_start(s->pktout);
5166 for (i = 0; i < s->nmacs; i++) {
5167 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5168 if (i < s->nmacs - 1)
5169 ssh2_pkt_addstring_str(s->pktout, ",");
5171 /* List server->client MAC algorithms. */
5172 ssh2_pkt_addstring_start(s->pktout);
5173 for (i = 0; i < s->nmacs; i++) {
5174 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5175 if (i < s->nmacs - 1)
5176 ssh2_pkt_addstring_str(s->pktout, ",");
5178 /* List client->server compression algorithms. */
5179 ssh2_pkt_addstring_start(s->pktout);
5180 assert(lenof(compressions) > 1);
5181 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5182 for (i = 0; i < lenof(compressions); i++) {
5183 const struct ssh_compress *c = compressions[i];
5184 if (c != s->preferred_comp) {
5185 ssh2_pkt_addstring_str(s->pktout, ",");
5186 ssh2_pkt_addstring_str(s->pktout, c->name);
5189 /* List server->client compression algorithms. */
5190 ssh2_pkt_addstring_start(s->pktout);
5191 assert(lenof(compressions) > 1);
5192 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5193 for (i = 0; i < lenof(compressions); i++) {
5194 const struct ssh_compress *c = compressions[i];
5195 if (c != s->preferred_comp) {
5196 ssh2_pkt_addstring_str(s->pktout, ",");
5197 ssh2_pkt_addstring_str(s->pktout, c->name);
5200 /* List client->server languages. Empty list. */
5201 ssh2_pkt_addstring_start(s->pktout);
5202 /* List server->client languages. Empty list. */
5203 ssh2_pkt_addstring_start(s->pktout);
5204 /* First KEX packet does _not_ follow, because we're not that brave. */
5205 ssh2_pkt_addbool(s->pktout, FALSE);
5207 ssh2_pkt_adduint32(s->pktout, 0);
5210 s->our_kexinitlen = s->pktout->length - 5;
5211 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5212 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5214 ssh2_pkt_send_noqueue(ssh, s->pktout);
5220 * Now examine the other side's KEXINIT to see what we're up
5224 char *str, *preferred;
5227 if (pktin->type != SSH2_MSG_KEXINIT) {
5228 bombout(("expected key exchange packet from server"));
5232 ssh->hostkey = NULL;
5233 s->cscipher_tobe = NULL;
5234 s->sccipher_tobe = NULL;
5235 s->csmac_tobe = NULL;
5236 s->scmac_tobe = NULL;
5237 s->cscomp_tobe = NULL;
5238 s->sccomp_tobe = NULL;
5239 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5241 pktin->savedpos += 16; /* skip garbage cookie */
5242 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5245 for (i = 0; i < s->n_preferred_kex; i++) {
5246 const struct ssh_kexes *k = s->preferred_kex[i];
5250 for (j = 0; j < k->nkexes; j++) {
5251 if (!preferred) preferred = k->list[j]->name;
5252 if (in_commasep_string(k->list[j]->name, str, len)) {
5253 ssh->kex = k->list[j];
5262 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5263 str ? str : "(null)"));
5267 * Note that the server's guess is considered wrong if it doesn't match
5268 * the first algorithm in our list, even if it's still the algorithm
5271 s->guessok = first_in_commasep_string(preferred, str, len);
5272 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5273 for (i = 0; i < lenof(hostkey_algs); i++) {
5274 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5275 ssh->hostkey = hostkey_algs[i];
5279 s->guessok = s->guessok &&
5280 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5281 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5282 for (i = 0; i < s->n_preferred_ciphers; i++) {
5283 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5285 s->warn_cscipher = TRUE;
5287 for (j = 0; j < c->nciphers; j++) {
5288 if (in_commasep_string(c->list[j]->name, str, len)) {
5289 s->cscipher_tobe = c->list[j];
5294 if (s->cscipher_tobe)
5297 if (!s->cscipher_tobe) {
5298 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5299 str ? str : "(null)"));
5303 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5304 for (i = 0; i < s->n_preferred_ciphers; i++) {
5305 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5307 s->warn_sccipher = TRUE;
5309 for (j = 0; j < c->nciphers; j++) {
5310 if (in_commasep_string(c->list[j]->name, str, len)) {
5311 s->sccipher_tobe = c->list[j];
5316 if (s->sccipher_tobe)
5319 if (!s->sccipher_tobe) {
5320 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5321 str ? str : "(null)"));
5325 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5326 for (i = 0; i < s->nmacs; i++) {
5327 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5328 s->csmac_tobe = s->maclist[i];
5332 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5333 for (i = 0; i < s->nmacs; i++) {
5334 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5335 s->scmac_tobe = s->maclist[i];
5339 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5340 for (i = 0; i < lenof(compressions) + 1; i++) {
5341 const struct ssh_compress *c =
5342 i == 0 ? s->preferred_comp : compressions[i - 1];
5343 if (in_commasep_string(c->name, str, len)) {
5348 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5349 for (i = 0; i < lenof(compressions) + 1; i++) {
5350 const struct ssh_compress *c =
5351 i == 0 ? s->preferred_comp : compressions[i - 1];
5352 if (in_commasep_string(c->name, str, len)) {
5357 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5358 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5359 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5362 ssh_set_frozen(ssh, 1);
5363 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5365 ssh_dialog_callback, ssh);
5366 if (s->dlgret < 0) {
5370 bombout(("Unexpected data from server while"
5371 " waiting for user response"));
5374 } while (pktin || inlen > 0);
5375 s->dlgret = ssh->user_response;
5377 ssh_set_frozen(ssh, 0);
5378 if (s->dlgret == 0) {
5379 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5385 if (s->warn_cscipher) {
5386 ssh_set_frozen(ssh, 1);
5387 s->dlgret = askalg(ssh->frontend,
5388 "client-to-server cipher",
5389 s->cscipher_tobe->name,
5390 ssh_dialog_callback, ssh);
5391 if (s->dlgret < 0) {
5395 bombout(("Unexpected data from server while"
5396 " waiting for user response"));
5399 } while (pktin || inlen > 0);
5400 s->dlgret = ssh->user_response;
5402 ssh_set_frozen(ssh, 0);
5403 if (s->dlgret == 0) {
5404 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5410 if (s->warn_sccipher) {
5411 ssh_set_frozen(ssh, 1);
5412 s->dlgret = askalg(ssh->frontend,
5413 "server-to-client cipher",
5414 s->sccipher_tobe->name,
5415 ssh_dialog_callback, ssh);
5416 if (s->dlgret < 0) {
5420 bombout(("Unexpected data from server while"
5421 " waiting for user response"));
5424 } while (pktin || inlen > 0);
5425 s->dlgret = ssh->user_response;
5427 ssh_set_frozen(ssh, 0);
5428 if (s->dlgret == 0) {
5429 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5435 ssh->exhash = ssh->kex->hash->init();
5436 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5437 hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5438 hash_string(ssh->kex->hash, ssh->exhash,
5439 s->our_kexinit, s->our_kexinitlen);
5440 sfree(s->our_kexinit);
5441 if (pktin->length > 5)
5442 hash_string(ssh->kex->hash, ssh->exhash,
5443 pktin->data + 5, pktin->length - 5);
5445 if (s->ignorepkt) /* first_kex_packet_follows */
5446 crWaitUntil(pktin); /* Ignore packet */
5450 * Work out the number of bits of key we will need from the key
5451 * exchange. We start with the maximum key length of either
5457 csbits = s->cscipher_tobe->keylen;
5458 scbits = s->sccipher_tobe->keylen;
5459 s->nbits = (csbits > scbits ? csbits : scbits);
5461 /* The keys only have hlen-bit entropy, since they're based on
5462 * a hash. So cap the key size at hlen bits. */
5463 if (s->nbits > ssh->kex->hash->hlen * 8)
5464 s->nbits = ssh->kex->hash->hlen * 8;
5467 * If we're doing Diffie-Hellman group exchange, start by
5468 * requesting a group.
5470 if (!ssh->kex->pdata) {
5471 logevent("Doing Diffie-Hellman group exchange");
5472 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5474 * Work out how big a DH group we will need to allow that
5477 s->pbits = 512 << ((s->nbits - 1) / 64);
5478 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5479 ssh2_pkt_adduint32(s->pktout, s->pbits);
5480 ssh2_pkt_send_noqueue(ssh, s->pktout);
5483 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5484 bombout(("expected key exchange group packet from server"));
5487 s->p = ssh2_pkt_getmp(pktin);
5488 s->g = ssh2_pkt_getmp(pktin);
5489 if (!s->p || !s->g) {
5490 bombout(("unable to read mp-ints from incoming group packet"));
5493 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5494 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5495 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5497 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5498 ssh->kex_ctx = dh_setup_group(ssh->kex);
5499 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5500 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5501 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5502 ssh->kex->groupname);
5505 logevent("Doing Diffie-Hellman key exchange");
5507 * Now generate and send e for Diffie-Hellman.
5509 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5510 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5511 s->pktout = ssh2_pkt_init(s->kex_init_value);
5512 ssh2_pkt_addmp(s->pktout, s->e);
5513 ssh2_pkt_send_noqueue(ssh, s->pktout);
5515 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5517 if (pktin->type != s->kex_reply_value) {
5518 bombout(("expected key exchange reply packet from server"));
5521 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5522 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5523 s->f = ssh2_pkt_getmp(pktin);
5525 bombout(("unable to parse key exchange reply packet"));
5528 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5530 s->K = dh_find_K(ssh->kex_ctx, s->f);
5532 /* We assume everything from now on will be quick, and it might
5533 * involve user interaction. */
5534 set_busy_status(ssh->frontend, BUSY_NOT);
5536 hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen);
5537 if (!ssh->kex->pdata) {
5538 hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits);
5539 hash_mpint(ssh->kex->hash, ssh->exhash, s->p);
5540 hash_mpint(ssh->kex->hash, ssh->exhash, s->g);
5542 hash_mpint(ssh->kex->hash, ssh->exhash, s->e);
5543 hash_mpint(ssh->kex->hash, ssh->exhash, s->f);
5544 hash_mpint(ssh->kex->hash, ssh->exhash, s->K);
5545 assert(ssh->kex->hash->hlen <= sizeof(s->exchange_hash));
5546 ssh->kex->hash->final(ssh->exhash, s->exchange_hash);
5548 dh_cleanup(ssh->kex_ctx);
5549 ssh->kex_ctx = NULL;
5552 debug(("Exchange hash is:\n"));
5553 dmemdump(s->exchange_hash, ssh->kex->hash->hlen);
5556 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5558 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5559 (char *)s->exchange_hash,
5560 ssh->kex->hash->hlen)) {
5561 bombout(("Server's host key did not match the signature supplied"));
5566 * Authenticate remote host: verify host key. (We've already
5567 * checked the signature of the exchange hash.)
5569 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5570 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5571 ssh_set_frozen(ssh, 1);
5572 s->dlgret = verify_ssh_host_key(ssh->frontend,
5573 ssh->savedhost, ssh->savedport,
5574 ssh->hostkey->keytype, s->keystr,
5576 ssh_dialog_callback, ssh);
5577 if (s->dlgret < 0) {
5581 bombout(("Unexpected data from server while waiting"
5582 " for user host key response"));
5585 } while (pktin || inlen > 0);
5586 s->dlgret = ssh->user_response;
5588 ssh_set_frozen(ssh, 0);
5589 if (s->dlgret == 0) {
5590 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5594 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5595 logevent("Host key fingerprint is:");
5596 logevent(s->fingerprint);
5598 sfree(s->fingerprint);
5600 ssh->hostkey->freekey(s->hkey);
5603 * The exchange hash from the very first key exchange is also
5604 * the session id, used in session key construction and
5607 if (!s->got_session_id) {
5608 assert(sizeof(s->exchange_hash) <= sizeof(ssh->v2_session_id));
5609 memcpy(ssh->v2_session_id, s->exchange_hash,
5610 sizeof(s->exchange_hash));
5611 ssh->v2_session_id_len = ssh->kex->hash->hlen;
5612 assert(ssh->v2_session_id_len <= sizeof(ssh->v2_session_id));
5613 s->got_session_id = TRUE;
5617 * Send SSH2_MSG_NEWKEYS.
5619 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5620 ssh2_pkt_send_noqueue(ssh, s->pktout);
5621 ssh->outgoing_data_size = 0; /* start counting from here */
5624 * We've sent client NEWKEYS, so create and initialise
5625 * client-to-server session keys.
5627 if (ssh->cs_cipher_ctx)
5628 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5629 ssh->cscipher = s->cscipher_tobe;
5630 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5632 if (ssh->cs_mac_ctx)
5633 ssh->csmac->free_context(ssh->cs_mac_ctx);
5634 ssh->csmac = s->csmac_tobe;
5635 ssh->cs_mac_ctx = ssh->csmac->make_context();
5637 if (ssh->cs_comp_ctx)
5638 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5639 ssh->cscomp = s->cscomp_tobe;
5640 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5643 * Set IVs on client-to-server keys. Here we use the exchange
5644 * hash from the _first_ key exchange.
5647 unsigned char keyspace[40];
5648 ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace);
5649 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5650 ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace);
5651 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5652 ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace);
5653 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5656 logeventf(ssh, "Initialised %.200s client->server encryption",
5657 ssh->cscipher->text_name);
5658 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5659 ssh->csmac->text_name);
5660 if (ssh->cscomp->text_name)
5661 logeventf(ssh, "Initialised %s compression",
5662 ssh->cscomp->text_name);
5665 * Now our end of the key exchange is complete, we can send all
5666 * our queued higher-layer packets.
5668 ssh->queueing = FALSE;
5669 ssh2_pkt_queuesend(ssh);
5672 * Expect SSH2_MSG_NEWKEYS from server.
5675 if (pktin->type != SSH2_MSG_NEWKEYS) {
5676 bombout(("expected new-keys packet from server"));
5679 ssh->incoming_data_size = 0; /* start counting from here */
5682 * We've seen server NEWKEYS, so create and initialise
5683 * server-to-client session keys.
5685 if (ssh->sc_cipher_ctx)
5686 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5687 ssh->sccipher = s->sccipher_tobe;
5688 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5690 if (ssh->sc_mac_ctx)
5691 ssh->scmac->free_context(ssh->sc_mac_ctx);
5692 ssh->scmac = s->scmac_tobe;
5693 ssh->sc_mac_ctx = ssh->scmac->make_context();
5695 if (ssh->sc_comp_ctx)
5696 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5697 ssh->sccomp = s->sccomp_tobe;
5698 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5701 * Set IVs on server-to-client keys. Here we use the exchange
5702 * hash from the _first_ key exchange.
5705 unsigned char keyspace[40];
5706 ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace);
5707 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5708 ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace);
5709 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5710 ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace);
5711 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5713 logeventf(ssh, "Initialised %.200s server->client encryption",
5714 ssh->sccipher->text_name);
5715 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5716 ssh->scmac->text_name);
5717 if (ssh->sccomp->text_name)
5718 logeventf(ssh, "Initialised %s decompression",
5719 ssh->sccomp->text_name);
5722 * Free key exchange data.
5726 if (!ssh->kex->pdata) {
5732 * Key exchange is over. Loop straight back round if we have a
5733 * deferred rekey reason.
5735 if (ssh->deferred_rekey_reason) {
5736 logevent(ssh->deferred_rekey_reason);
5738 ssh->deferred_rekey_reason = NULL;
5739 goto begin_key_exchange;
5743 * Otherwise, schedule a timer for our next rekey.
5745 ssh->kex_in_progress = FALSE;
5746 ssh->last_rekey = GETTICKCOUNT();
5747 if (ssh->cfg.ssh_rekey_time != 0)
5748 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5752 * If this is the first key exchange phase, we must pass the
5753 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5754 * wants to see it but because it will need time to initialise
5755 * itself before it sees an actual packet. In subsequent key
5756 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5757 * it would only confuse the layer above.
5759 if (s->activated_authconn) {
5762 s->activated_authconn = TRUE;
5765 * Now we're encrypting. Begin returning 1 to the protocol main
5766 * function so that other things can run on top of the
5767 * transport. If we ever see a KEXINIT, we must go back to the
5770 * We _also_ go back to the start if we see pktin==NULL and
5771 * inlen==-1, because this is a special signal meaning
5772 * `initiate client-driven rekey', and `in' contains a message
5773 * giving the reason for the rekey.
5775 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5776 (!pktin && inlen == -1))) {
5781 logevent("Server initiated key re-exchange");
5784 * Special case: if the server bug is set that doesn't
5785 * allow rekeying, we give a different log message and
5786 * continue waiting. (If such a server _initiates_ a rekey,
5787 * we process it anyway!)
5789 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5790 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5792 /* Reset the counters, so that at least this message doesn't
5793 * hit the event log _too_ often. */
5794 ssh->outgoing_data_size = 0;
5795 ssh->incoming_data_size = 0;
5796 if (ssh->cfg.ssh_rekey_time != 0) {
5798 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5801 goto wait_for_rekey; /* this is utterly horrid */
5803 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5806 goto begin_key_exchange;
5812 * Add data to an SSH-2 channel output buffer.
5814 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5817 bufchain_add(&c->v.v2.outbuffer, buf, len);
5821 * Attempt to send data on an SSH-2 channel.
5823 static int ssh2_try_send(struct ssh_channel *c)
5826 struct Packet *pktout;
5828 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5831 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5832 if ((unsigned)len > c->v.v2.remwindow)
5833 len = c->v.v2.remwindow;
5834 if ((unsigned)len > c->v.v2.remmaxpkt)
5835 len = c->v.v2.remmaxpkt;
5836 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5837 ssh2_pkt_adduint32(pktout, c->remoteid);
5838 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5839 ssh2_pkt_addstring_start(pktout);
5840 ssh2_pkt_addstring_data(pktout, data, len);
5841 end_log_omission(ssh, pktout);
5842 ssh2_pkt_send(ssh, pktout);
5843 bufchain_consume(&c->v.v2.outbuffer, len);
5844 c->v.v2.remwindow -= len;
5848 * After having sent as much data as we can, return the amount
5851 return bufchain_size(&c->v.v2.outbuffer);
5854 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5858 return; /* don't send on closing channels */
5859 bufsize = ssh2_try_send(c);
5862 case CHAN_MAINSESSION:
5863 /* stdin need not receive an unthrottle
5864 * notification since it will be polled */
5867 x11_unthrottle(c->u.x11.s);
5870 /* agent sockets are request/response and need no
5871 * buffer management */
5874 pfd_unthrottle(c->u.pfd.s);
5881 * Potentially enlarge the window on an SSH-2 channel.
5883 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5888 * Never send WINDOW_ADJUST for a channel that the remote side
5889 * already thinks it's closed; there's no point, since it won't
5890 * be sending any more data anyway.
5896 * Only send a WINDOW_ADJUST if there's significantly more window
5897 * available than the other end thinks there is. This saves us
5898 * sending a WINDOW_ADJUST for every character in a shell session.
5900 * "Significant" is arbitrarily defined as half the window size.
5902 if (newwin > c->v.v2.locwindow * 2) {
5903 struct Packet *pktout;
5905 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5906 ssh2_pkt_adduint32(pktout, c->remoteid);
5907 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5908 ssh2_pkt_send(ssh, pktout);
5909 c->v.v2.locwindow = newwin;
5913 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5915 unsigned i = ssh_pkt_getuint32(pktin);
5916 struct ssh_channel *c;
5917 c = find234(ssh->channels, &i, ssh_channelfind);
5918 if (c && !c->closes) {
5919 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5920 ssh2_try_send_and_unthrottle(c);
5924 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5928 unsigned i = ssh_pkt_getuint32(pktin);
5929 struct ssh_channel *c;
5930 c = find234(ssh->channels, &i, ssh_channelfind);
5932 return; /* nonexistent channel */
5933 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5934 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5935 return; /* extended but not stderr */
5936 ssh_pkt_getstring(pktin, &data, &length);
5939 c->v.v2.locwindow -= length;
5941 case CHAN_MAINSESSION:
5943 from_backend(ssh->frontend, pktin->type ==
5944 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5948 bufsize = x11_send(c->u.x11.s, data, length);
5951 bufsize = pfd_send(c->u.pfd.s, data, length);
5954 while (length > 0) {
5955 if (c->u.a.lensofar < 4) {
5956 unsigned int l = min(4 - c->u.a.lensofar, length);
5957 memcpy(c->u.a.msglen + c->u.a.lensofar,
5961 c->u.a.lensofar += l;
5963 if (c->u.a.lensofar == 4) {
5965 4 + GET_32BIT(c->u.a.msglen);
5966 c->u.a.message = snewn(c->u.a.totallen,
5968 memcpy(c->u.a.message, c->u.a.msglen, 4);
5970 if (c->u.a.lensofar >= 4 && length > 0) {
5972 min(c->u.a.totallen - c->u.a.lensofar,
5974 memcpy(c->u.a.message + c->u.a.lensofar,
5978 c->u.a.lensofar += l;
5980 if (c->u.a.lensofar == c->u.a.totallen) {
5983 if (agent_query(c->u.a.message,
5986 ssh_agentf_callback, c))
5987 ssh_agentf_callback(c, reply, replylen);
5988 sfree(c->u.a.message);
5989 c->u.a.lensofar = 0;
5996 * If we are not buffering too much data,
5997 * enlarge the window again at the remote side.
5999 if (bufsize < OUR_V2_WINSIZE)
6000 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
6004 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
6006 unsigned i = ssh_pkt_getuint32(pktin);
6007 struct ssh_channel *c;
6009 c = find234(ssh->channels, &i, ssh_channelfind);
6011 return; /* nonexistent channel */
6013 if (c->type == CHAN_X11) {
6015 * Remote EOF on an X11 channel means we should
6016 * wrap up and close the channel ourselves.
6018 x11_close(c->u.x11.s);
6020 } else if (c->type == CHAN_AGENT) {
6022 } else if (c->type == CHAN_SOCKDATA) {
6023 pfd_close(c->u.pfd.s);
6028 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6030 unsigned i = ssh_pkt_getuint32(pktin);
6031 struct ssh_channel *c;
6032 struct Packet *pktout;
6034 c = find234(ssh->channels, &i, ssh_channelfind);
6035 if (!c || c->halfopen) {
6036 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6037 c ? "half-open" : "nonexistent", i));
6040 /* Do pre-close processing on the channel. */
6042 case CHAN_MAINSESSION:
6043 ssh->mainchan = NULL;
6044 update_specials_menu(ssh->frontend);
6047 if (c->u.x11.s != NULL)
6048 x11_close(c->u.x11.s);
6055 if (c->u.pfd.s != NULL)
6056 pfd_close(c->u.pfd.s);
6060 if (c->closes == 0) {
6061 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6062 ssh2_pkt_adduint32(pktout, c->remoteid);
6063 ssh2_pkt_send(ssh, pktout);
6065 del234(ssh->channels, c);
6066 bufchain_clear(&c->v.v2.outbuffer);
6070 * See if that was the last channel left open.
6071 * (This is only our termination condition if we're
6072 * not running in -N mode.)
6074 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6076 * We used to send SSH_MSG_DISCONNECT here,
6077 * because I'd believed that _every_ conforming
6078 * SSH-2 connection had to end with a disconnect
6079 * being sent by at least one side; apparently
6080 * I was wrong and it's perfectly OK to
6081 * unceremoniously slam the connection shut
6082 * when you're done, and indeed OpenSSH feels
6083 * this is more polite than sending a
6084 * DISCONNECT. So now we don't.
6086 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6090 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6092 unsigned i = ssh_pkt_getuint32(pktin);
6093 struct ssh_channel *c;
6094 struct Packet *pktout;
6096 c = find234(ssh->channels, &i, ssh_channelfind);
6098 return; /* nonexistent channel */
6099 if (c->type != CHAN_SOCKDATA_DORMANT)
6100 return; /* dunno why they're confirming this */
6101 c->remoteid = ssh_pkt_getuint32(pktin);
6102 c->halfopen = FALSE;
6103 c->type = CHAN_SOCKDATA;
6104 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6105 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6107 pfd_confirm(c->u.pfd.s);
6110 * We have a pending close on this channel,
6111 * which we decided on before the server acked
6112 * the channel open. So now we know the
6113 * remoteid, we can close it again.
6115 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6116 ssh2_pkt_adduint32(pktout, c->remoteid);
6117 ssh2_pkt_send(ssh, pktout);
6121 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6123 static const char *const reasons[] = {
6124 "<unknown reason code>",
6125 "Administratively prohibited",
6127 "Unknown channel type",
6128 "Resource shortage",
6130 unsigned i = ssh_pkt_getuint32(pktin);
6131 unsigned reason_code;
6132 char *reason_string;
6134 struct ssh_channel *c;
6135 c = find234(ssh->channels, &i, ssh_channelfind);
6137 return; /* nonexistent channel */
6138 if (c->type != CHAN_SOCKDATA_DORMANT)
6139 return; /* dunno why they're failing this */
6141 reason_code = ssh_pkt_getuint32(pktin);
6142 if (reason_code >= lenof(reasons))
6143 reason_code = 0; /* ensure reasons[reason_code] in range */
6144 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6145 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6146 reasons[reason_code], reason_length, reason_string);
6148 pfd_close(c->u.pfd.s);
6150 del234(ssh->channels, c);
6154 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6158 int typelen, want_reply;
6159 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6160 struct ssh_channel *c;
6161 struct Packet *pktout;
6163 localid = ssh_pkt_getuint32(pktin);
6164 ssh_pkt_getstring(pktin, &type, &typelen);
6165 want_reply = ssh2_pkt_getbool(pktin);
6168 * First, check that the channel exists. Otherwise,
6169 * we can instantly disconnect with a rude message.
6171 c = find234(ssh->channels, &localid, ssh_channelfind);
6173 char *buf = dupprintf("Received channel request for nonexistent"
6174 " channel %d", localid);
6175 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6181 * Having got the channel number, we now look at
6182 * the request type string to see if it's something
6185 if (c == ssh->mainchan) {
6187 * We recognise "exit-status" and "exit-signal" on
6188 * the primary channel.
6190 if (typelen == 11 &&
6191 !memcmp(type, "exit-status", 11)) {
6193 ssh->exitcode = ssh_pkt_getuint32(pktin);
6194 logeventf(ssh, "Server sent command exit status %d",
6196 reply = SSH2_MSG_CHANNEL_SUCCESS;
6198 } else if (typelen == 11 &&
6199 !memcmp(type, "exit-signal", 11)) {
6201 int is_plausible = TRUE, is_int = FALSE;
6202 char *fmt_sig = "", *fmt_msg = "";
6204 int msglen = 0, core = FALSE;
6205 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6206 * provide an `int' for the signal, despite its
6207 * having been a `string' in the drafts since at
6208 * least 2001. (Fixed in session.c 1.147.) Try to
6209 * infer which we can safely parse it as. */
6211 unsigned char *p = pktin->body +
6213 long len = pktin->length - pktin->savedpos;
6214 unsigned long num = GET_32BIT(p); /* what is it? */
6215 /* If it's 0, it hardly matters; assume string */
6219 int maybe_int = FALSE, maybe_str = FALSE;
6220 #define CHECK_HYPOTHESIS(offset, result) \
6223 if (q >= 0 && q+4 <= len) { \
6224 q = q + 4 + GET_32BIT(p+q); \
6225 if (q >= 0 && q+4 <= len && \
6226 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6230 CHECK_HYPOTHESIS(4+1, maybe_int);
6231 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6232 #undef CHECK_HYPOTHESIS
6233 if (maybe_int && !maybe_str)
6235 else if (!maybe_int && maybe_str)
6238 /* Crikey. Either or neither. Panic. */
6239 is_plausible = FALSE;
6244 /* Old non-standard OpenSSH. */
6245 int signum = ssh_pkt_getuint32(pktin);
6246 fmt_sig = dupprintf(" %d", signum);
6248 /* As per the drafts. */
6251 ssh_pkt_getstring(pktin, &sig, &siglen);
6252 /* Signal name isn't supposed to be blank, but
6253 * let's cope gracefully if it is. */
6255 fmt_sig = dupprintf(" \"%.*s\"",
6259 core = ssh2_pkt_getbool(pktin);
6260 ssh_pkt_getstring(pktin, &msg, &msglen);
6262 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6264 /* ignore lang tag */
6265 } /* else don't attempt to parse */
6266 logeventf(ssh, "Server exited on signal%s%s%s",
6267 fmt_sig, core ? " (core dumped)" : "",
6269 if (*fmt_sig) sfree(fmt_sig);
6270 if (*fmt_msg) sfree(fmt_msg);
6271 reply = SSH2_MSG_CHANNEL_SUCCESS;
6276 * This is a channel request we don't know
6277 * about, so we now either ignore the request
6278 * or respond with CHANNEL_FAILURE, depending
6281 reply = SSH2_MSG_CHANNEL_FAILURE;
6284 pktout = ssh2_pkt_init(reply);
6285 ssh2_pkt_adduint32(pktout, c->remoteid);
6286 ssh2_pkt_send(ssh, pktout);
6290 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6293 int typelen, want_reply;
6294 struct Packet *pktout;
6296 ssh_pkt_getstring(pktin, &type, &typelen);
6297 want_reply = ssh2_pkt_getbool(pktin);
6300 * We currently don't support any global requests
6301 * at all, so we either ignore the request or
6302 * respond with REQUEST_FAILURE, depending on
6306 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6307 ssh2_pkt_send(ssh, pktout);
6311 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6319 struct ssh_channel *c;
6320 unsigned remid, winsize, pktsize;
6321 struct Packet *pktout;
6323 ssh_pkt_getstring(pktin, &type, &typelen);
6324 c = snew(struct ssh_channel);
6327 remid = ssh_pkt_getuint32(pktin);
6328 winsize = ssh_pkt_getuint32(pktin);
6329 pktsize = ssh_pkt_getuint32(pktin);
6331 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6334 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6335 addrstr = snewn(peeraddrlen+1, char);
6336 memcpy(addrstr, peeraddr, peeraddrlen);
6337 addrstr[peeraddrlen] = '\0';
6338 peerport = ssh_pkt_getuint32(pktin);
6340 logeventf(ssh, "Received X11 connect request from %s:%d",
6343 if (!ssh->X11_fwd_enabled)
6344 error = "X11 forwarding is not enabled";
6345 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6346 ssh->x11auth, addrstr, peerport,
6347 &ssh->cfg) != NULL) {
6348 error = "Unable to open an X11 connection";
6350 logevent("Opening X11 forward connection succeeded");
6355 } else if (typelen == 15 &&
6356 !memcmp(type, "forwarded-tcpip", 15)) {
6357 struct ssh_rportfwd pf, *realpf;
6360 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6361 pf.sport = ssh_pkt_getuint32(pktin);
6362 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6363 peerport = ssh_pkt_getuint32(pktin);
6364 realpf = find234(ssh->rportfwds, &pf, NULL);
6365 logeventf(ssh, "Received remote port %d open request "
6366 "from %s:%d", pf.sport, peeraddr, peerport);
6367 if (realpf == NULL) {
6368 error = "Remote port is not recognised";
6370 const char *e = pfd_newconnect(&c->u.pfd.s,
6374 realpf->pfrec->addressfamily);
6375 logeventf(ssh, "Attempting to forward remote port to "
6376 "%s:%d", realpf->dhost, realpf->dport);
6378 logeventf(ssh, "Port open failed: %s", e);
6379 error = "Port open failed";
6381 logevent("Forwarded port opened successfully");
6382 c->type = CHAN_SOCKDATA;
6385 } else if (typelen == 22 &&
6386 !memcmp(type, "auth-agent@openssh.com", 22)) {
6387 if (!ssh->agentfwd_enabled)
6388 error = "Agent forwarding is not enabled";
6390 c->type = CHAN_AGENT; /* identify channel type */
6391 c->u.a.lensofar = 0;
6394 error = "Unsupported channel type requested";
6397 c->remoteid = remid;
6398 c->halfopen = FALSE;
6400 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6401 ssh2_pkt_adduint32(pktout, c->remoteid);
6402 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6403 ssh2_pkt_addstring(pktout, error);
6404 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6405 ssh2_pkt_send(ssh, pktout);
6406 logeventf(ssh, "Rejected channel open: %s", error);
6409 c->localid = alloc_channel_id(ssh);
6411 c->v.v2.locwindow = OUR_V2_WINSIZE;
6412 c->v.v2.remwindow = winsize;
6413 c->v.v2.remmaxpkt = pktsize;
6414 bufchain_init(&c->v.v2.outbuffer);
6415 add234(ssh->channels, c);
6416 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6417 ssh2_pkt_adduint32(pktout, c->remoteid);
6418 ssh2_pkt_adduint32(pktout, c->localid);
6419 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6420 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6421 ssh2_pkt_send(ssh, pktout);
6426 * Buffer banner messages for later display at some convenient point.
6428 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6430 /* Arbitrary limit to prevent unbounded inflation of buffer */
6431 if (bufchain_size(&ssh->banner) <= 131072) {
6432 char *banner = NULL;
6434 ssh_pkt_getstring(pktin, &banner, &size);
6436 bufchain_add(&ssh->banner, banner, size);
6440 /* Helper function to deal with sending tty modes for "pty-req" */
6441 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6443 struct Packet *pktout = (struct Packet *)data;
6445 unsigned int arg = 0;
6446 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6447 if (i == lenof(ssh_ttymodes)) return;
6448 switch (ssh_ttymodes[i].type) {
6450 arg = ssh_tty_parse_specchar(val);
6453 arg = ssh_tty_parse_boolean(val);
6456 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6457 ssh2_pkt_adduint32(pktout, arg);
6461 * Handle the SSH-2 userauth and connection layers.
6463 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6464 struct Packet *pktin)
6466 struct do_ssh2_authconn_state {
6468 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6470 AUTH_KEYBOARD_INTERACTIVE
6474 AUTH_TYPE_PUBLICKEY,
6475 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6476 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6478 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6479 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6481 int done_service_req;
6482 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6483 int tried_pubkey_config, tried_agent;
6484 int kbd_inter_running, kbd_inter_refused;
6486 int num_prompts, curr_prompt, echo;
6491 void *publickey_blob;
6492 int publickey_bloblen;
6493 unsigned char request[5], *response, *p;
6497 char *pkblob, *alg, *commentp;
6498 int pklen, alglen, commentlen;
6499 int siglen, retlen, len;
6500 char *q, *agentreq, *ret;
6502 int num_env, env_left, env_ok;
6503 struct Packet *pktout;
6505 crState(do_ssh2_authconn_state);
6507 crBegin(ssh->do_ssh2_authconn_crstate);
6509 s->done_service_req = FALSE;
6510 s->we_are_in = FALSE;
6511 if (!ssh->cfg.ssh_no_userauth) {
6513 * Request userauth protocol, and await a response to it.
6515 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6516 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6517 ssh2_pkt_send(ssh, s->pktout);
6518 crWaitUntilV(pktin);
6519 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6520 s->done_service_req = TRUE;
6522 if (!s->done_service_req) {
6524 * Request connection protocol directly, without authentication.
6526 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6527 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6528 ssh2_pkt_send(ssh, s->pktout);
6529 crWaitUntilV(pktin);
6530 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6531 s->we_are_in = TRUE; /* no auth required */
6533 bombout(("Server refused service request"));
6539 * We repeat this whole loop, including the username prompt,
6540 * until we manage a successful authentication. If the user
6541 * types the wrong _password_, they can be sent back to the
6542 * beginning to try another username, if this is configured on.
6543 * (If they specify a username in the config, they are never
6544 * asked, even if they do give a wrong password.)
6546 * I think this best serves the needs of
6548 * - the people who have no configuration, no keys, and just
6549 * want to try repeated (username,password) pairs until they
6550 * type both correctly
6552 * - people who have keys and configuration but occasionally
6553 * need to fall back to passwords
6555 * - people with a key held in Pageant, who might not have
6556 * logged in to a particular machine before; so they want to
6557 * type a username, and then _either_ their key will be
6558 * accepted, _or_ they will type a password. If they mistype
6559 * the username they will want to be able to get back and
6562 s->username[0] = '\0';
6563 s->got_username = FALSE;
6564 bufchain_init(&ssh->banner);
6565 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6566 ssh2_msg_userauth_banner;
6567 while (!s->we_are_in) {
6571 if (s->got_username && !ssh->cfg.change_username) {
6573 * We got a username last time round this loop, and
6574 * with change_username turned off we don't try to get
6577 } else if (!*ssh->cfg.username) {
6578 if (ssh_get_line && !ssh_getline_pw_only) {
6579 if (!ssh_get_line("login as: ",
6580 s->username, sizeof(s->username), FALSE)) {
6582 * get_line failed to get a username.
6585 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
6589 int ret; /* need not be saved across crReturn */
6590 c_write_str(ssh, "login as: ");
6592 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6594 crWaitUntilV(!pktin);
6595 ret = process_userpass_input(ssh, in, inlen);
6599 c_write_str(ssh, "\r\n");
6601 s->username[strcspn(s->username, "\n\r")] = '\0';
6604 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6605 s->username[sizeof(s->username)-1] = '\0';
6606 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6607 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6608 c_write_str(ssh, stuff);
6612 s->got_username = TRUE;
6615 * Send an authentication request using method "none": (a)
6616 * just in case it succeeds, and (b) so that we know what
6617 * authentication methods we can usefully try next.
6619 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6621 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6622 ssh2_pkt_addstring(s->pktout, s->username);
6623 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6624 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6625 ssh2_pkt_send(ssh, s->pktout);
6626 s->type = AUTH_TYPE_NONE;
6628 s->we_are_in = FALSE;
6630 s->tried_pubkey_config = FALSE;
6631 s->tried_agent = FALSE;
6632 s->kbd_inter_running = FALSE;
6633 s->kbd_inter_refused = FALSE;
6634 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6635 if (!filename_is_null(ssh->cfg.keyfile)) {
6637 logeventf(ssh, "Reading private key file \"%.150s\"",
6638 filename_to_str(&ssh->cfg.keyfile));
6639 keytype = key_type(&ssh->cfg.keyfile);
6640 if (keytype == SSH_KEYTYPE_SSH2) {
6642 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6643 &s->publickey_bloblen, NULL);
6646 logeventf(ssh, "Unable to use this key file (%s)",
6647 key_type_to_str(keytype));
6648 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6650 filename_to_str(&ssh->cfg.keyfile),
6651 key_type_to_str(keytype));
6652 c_write_str(ssh, msgbuf);
6654 s->publickey_blob = NULL;
6657 s->publickey_blob = NULL;
6661 * Wait for the result of the last authentication request.
6664 crWaitUntilV(pktin);
6666 * Now is a convenient point to spew any banner material
6667 * that we've accumulated. (This should ensure that when
6668 * we exit the auth loop, we haven't any left to deal
6672 int size = bufchain_size(&ssh->banner);
6674 * Don't show the banner if we're operating in
6675 * non-verbose non-interactive mode. (It's probably
6676 * a script, which means nobody will read the
6677 * banner _anyway_, and moreover the printing of
6678 * the banner will screw up processing on the
6679 * output of (say) plink.)
6681 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
6682 char *banner = snewn(size, char);
6683 bufchain_fetch(&ssh->banner, banner, size);
6684 c_write_untrusted(ssh, banner, size);
6687 bufchain_clear(&ssh->banner);
6689 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6690 logevent("Access granted");
6691 s->we_are_in = TRUE;
6695 if (s->kbd_inter_running &&
6696 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6698 * This is either a further set-of-prompts packet
6699 * in keyboard-interactive authentication, or it's
6700 * the same one and we came back here with `gotit'
6701 * set. In the former case, we must reset the
6702 * curr_prompt variable.
6706 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6707 /* FIXME: perhaps we should support this? */
6708 bombout(("PASSWD_CHANGEREQ not yet supported"));
6710 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6711 bombout(("Strange packet received during authentication: type %d",
6719 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6720 * we can look at the string in it and know what we can
6721 * helpfully try next.
6723 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6726 ssh_pkt_getstring(pktin, &methods, &methlen);
6727 s->kbd_inter_running = FALSE;
6728 if (!ssh2_pkt_getbool(pktin)) {
6730 * We have received an unequivocal Access
6731 * Denied. This can translate to a variety of
6734 * - if we'd just tried "none" authentication,
6735 * it's not worth printing anything at all
6737 * - if we'd just tried a public key _offer_,
6738 * the message should be "Server refused our
6739 * key" (or no message at all if the key
6740 * came from Pageant)
6742 * - if we'd just tried anything else, the
6743 * message really should be "Access denied".
6745 * Additionally, if we'd just tried password
6746 * authentication, we should break out of this
6747 * whole loop so as to go back to the username
6748 * prompt (iff we're configured to allow
6749 * username change attempts).
6751 if (s->type == AUTH_TYPE_NONE) {
6753 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6754 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6755 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6756 c_write_str(ssh, "Server refused our key\r\n");
6757 logevent("Server refused public key");
6758 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6759 /* server declined keyboard-interactive; ignore */
6761 c_write_str(ssh, "Access denied\r\n");
6762 logevent("Access denied");
6763 if (s->type == AUTH_TYPE_PASSWORD &&
6764 ssh->cfg.change_username) {
6765 /* XXX perhaps we should allow
6766 * keyboard-interactive to do this too? */
6767 s->we_are_in = FALSE;
6772 c_write_str(ssh, "Further authentication required\r\n");
6773 logevent("Further authentication required");
6777 in_commasep_string("publickey", methods, methlen);
6779 in_commasep_string("password", methods, methlen);
6780 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6781 in_commasep_string("keyboard-interactive", methods, methlen);
6785 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6789 * Most password/passphrase prompts will be
6790 * non-echoing, so we set this to 0 by default.
6791 * Exception is that some keyboard-interactive prompts
6792 * can be echoing, in which case we'll set this to 1.
6796 if (!s->method && s->can_pubkey &&
6797 agent_exists() && !s->tried_agent) {
6799 * Attempt public-key authentication using Pageant.
6804 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6805 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6807 s->tried_agent = TRUE;
6809 logevent("Pageant is running. Requesting keys.");
6811 /* Request the keys held by the agent. */
6812 PUT_32BIT(s->request, 1);
6813 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6814 if (!agent_query(s->request, 5, &r, &s->responselen,
6815 ssh_agent_callback, ssh)) {
6819 bombout(("Unexpected data from server while"
6820 " waiting for agent response"));
6823 } while (pktin || inlen > 0);
6824 r = ssh->agent_response;
6825 s->responselen = ssh->agent_response_len;
6827 s->response = (unsigned char *) r;
6828 if (s->response && s->responselen >= 5 &&
6829 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6830 s->p = s->response + 5;
6831 s->nkeys = GET_32BIT(s->p);
6833 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6834 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6837 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6838 s->pklen = GET_32BIT(s->p);
6840 if (s->publickey_blob &&
6841 s->pklen == s->publickey_bloblen &&
6842 !memcmp(s->p, s->publickey_blob,
6843 s->publickey_bloblen)) {
6844 logevent("This key matches configured key file");
6845 s->tried_pubkey_config = 1;
6847 s->pkblob = (char *)s->p;
6849 s->alglen = GET_32BIT(s->pkblob);
6850 s->alg = s->pkblob + 4;
6851 s->commentlen = GET_32BIT(s->p);
6853 s->commentp = (char *)s->p;
6854 s->p += s->commentlen;
6855 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6856 ssh2_pkt_addstring(s->pktout, s->username);
6857 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6858 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6859 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6860 ssh2_pkt_addstring_start(s->pktout);
6861 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6862 ssh2_pkt_addstring_start(s->pktout);
6863 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6864 ssh2_pkt_send(ssh, s->pktout);
6866 crWaitUntilV(pktin);
6867 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6868 logevent("Key refused");
6872 if (flags & FLAG_VERBOSE) {
6873 c_write_str(ssh, "Authenticating with "
6875 c_write(ssh, s->commentp, s->commentlen);
6876 c_write_str(ssh, "\" from agent\r\n");
6880 * Server is willing to accept the key.
6881 * Construct a SIGN_REQUEST.
6883 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6884 ssh2_pkt_addstring(s->pktout, s->username);
6885 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6886 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6887 ssh2_pkt_addbool(s->pktout, TRUE);
6888 ssh2_pkt_addstring_start(s->pktout);
6889 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6890 ssh2_pkt_addstring_start(s->pktout);
6891 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6893 s->siglen = s->pktout->length - 5 + 4 +
6894 ssh->v2_session_id_len;
6895 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6897 s->len = 1; /* message type */
6898 s->len += 4 + s->pklen; /* key blob */
6899 s->len += 4 + s->siglen; /* data to sign */
6900 s->len += 4; /* flags */
6901 s->agentreq = snewn(4 + s->len, char);
6902 PUT_32BIT(s->agentreq, s->len);
6903 s->q = s->agentreq + 4;
6904 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6905 PUT_32BIT(s->q, s->pklen);
6907 memcpy(s->q, s->pkblob, s->pklen);
6909 PUT_32BIT(s->q, s->siglen);
6911 /* Now the data to be signed... */
6912 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6913 PUT_32BIT(s->q, ssh->v2_session_id_len);
6916 memcpy(s->q, ssh->v2_session_id,
6917 ssh->v2_session_id_len);
6918 s->q += ssh->v2_session_id_len;
6919 memcpy(s->q, s->pktout->data + 5,
6920 s->pktout->length - 5);
6921 s->q += s->pktout->length - 5;
6922 /* And finally the (zero) flags word. */
6924 if (!agent_query(s->agentreq, s->len + 4,
6926 ssh_agent_callback, ssh)) {
6930 bombout(("Unexpected data from server"
6931 " while waiting for agent"
6935 } while (pktin || inlen > 0);
6936 vret = ssh->agent_response;
6937 s->retlen = ssh->agent_response_len;
6942 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6943 logevent("Sending Pageant's response");
6944 ssh2_add_sigblob(ssh, s->pktout,
6945 s->pkblob, s->pklen,
6947 GET_32BIT(s->ret + 5));
6948 ssh2_pkt_send(ssh, s->pktout);
6953 ("Pageant failed to answer challenge");
6964 if (!s->method && s->can_pubkey && s->publickey_blob
6965 && !s->tried_pubkey_config) {
6966 unsigned char *pub_blob;
6967 char *algorithm, *comment;
6970 s->tried_pubkey_config = TRUE;
6972 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6973 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6976 * Try the public key supplied in the configuration.
6978 * First, offer the public blob to see if the server is
6979 * willing to accept it.
6982 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6987 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6988 ssh2_pkt_addstring(s->pktout, s->username);
6989 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6990 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6991 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6992 ssh2_pkt_addstring(s->pktout, algorithm);
6993 ssh2_pkt_addstring_start(s->pktout);
6994 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6996 ssh2_pkt_send(ssh, s->pktout);
6997 logevent("Offered public key");
6999 crWaitUntilV(pktin);
7000 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
7002 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
7003 continue; /* key refused; give up on it */
7006 logevent("Offer of public key accepted");
7008 * Actually attempt a serious authentication using
7011 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
7012 sprintf(s->pwprompt,
7013 "Passphrase for key \"%.100s\": ",
7019 if (flags & FLAG_VERBOSE) {
7020 c_write_str(ssh, "Authenticating with public key \"");
7021 c_write_str(ssh, comment);
7022 c_write_str(ssh, "\"\r\n");
7024 s->method = AUTH_PUBLICKEY_FILE;
7028 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
7029 !s->kbd_inter_running) {
7030 s->method = AUTH_KEYBOARD_INTERACTIVE;
7031 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7033 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7034 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7036 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7037 ssh2_pkt_addstring(s->pktout, s->username);
7038 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7039 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
7040 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7041 ssh2_pkt_addstring(s->pktout, "");
7042 ssh2_pkt_send(ssh, s->pktout);
7044 crWaitUntilV(pktin);
7045 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7046 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7048 logevent("Keyboard-interactive authentication refused");
7049 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7050 s->kbd_inter_refused = TRUE; /* don't try it again */
7054 c_write_str(ssh, "Using keyboard-interactive authentication.\r\n");
7055 s->kbd_inter_running = TRUE;
7059 if (s->kbd_inter_running) {
7060 s->method = AUTH_KEYBOARD_INTERACTIVE;
7061 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7063 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7064 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7066 if (s->curr_prompt == 0) {
7068 * We've got a fresh USERAUTH_INFO_REQUEST.
7069 * Display header data, and start going through
7072 char *name, *inst, *lang;
7073 int name_len, inst_len, lang_len;
7075 ssh_pkt_getstring(pktin, &name, &name_len);
7076 ssh_pkt_getstring(pktin, &inst, &inst_len);
7077 ssh_pkt_getstring(pktin, &lang, &lang_len);
7079 c_write_untrusted(ssh, name, name_len);
7080 c_write_str(ssh, "\r\n");
7083 c_write_untrusted(ssh, inst, inst_len);
7084 c_write_str(ssh, "\r\n");
7086 s->num_prompts = ssh_pkt_getuint32(pktin);
7090 * If there are prompts remaining in the packet,
7091 * display one and get a response.
7093 if (s->curr_prompt < s->num_prompts) {
7097 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7098 if (prompt_len > 0) {
7099 static const char trunc[] = "<prompt truncated>: ";
7100 static const int prlen = sizeof(s->pwprompt) -
7102 if (prompt_len > prlen) {
7103 memcpy(s->pwprompt, prompt, prlen);
7104 strcpy(s->pwprompt + prlen, trunc);
7106 memcpy(s->pwprompt, prompt, prompt_len);
7107 s->pwprompt[prompt_len] = '\0';
7111 "<server failed to send prompt>: ");
7113 s->echo = ssh2_pkt_getbool(pktin);
7119 if (!s->method && s->can_passwd) {
7120 s->method = AUTH_PASSWORD;
7121 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7122 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7123 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
7130 if (!ssh_get_line(s->pwprompt, s->password,
7131 sizeof(s->password), TRUE)) {
7133 * get_line failed to get a password (for
7134 * example because one was supplied on the
7135 * command line which has already failed to
7138 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7139 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7144 int ret; /* need not be saved across crReturn */
7145 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
7148 setup_userpass_input(ssh, s->password,
7149 sizeof(s->password), s->echo);
7151 crWaitUntilV(!pktin);
7152 ret = process_userpass_input(ssh, in, inlen);
7156 c_write_str(ssh, "\r\n");
7160 if (s->method == AUTH_PUBLICKEY_FILE) {
7162 * We have our passphrase. Now try the actual authentication.
7164 struct ssh2_userkey *key;
7165 const char *error = NULL;
7167 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
7169 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7170 if (key == SSH2_WRONG_PASSPHRASE) {
7171 c_write_str(ssh, "Wrong passphrase\r\n");
7172 s->tried_pubkey_config = FALSE;
7174 c_write_str(ssh, "Unable to load private key (");
7175 c_write_str(ssh, error);
7176 c_write_str(ssh, ")\r\n");
7177 s->tried_pubkey_config = TRUE;
7179 /* Send a spurious AUTH_NONE to return to the top. */
7180 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7181 ssh2_pkt_addstring(s->pktout, s->username);
7182 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7183 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7184 ssh2_pkt_send(ssh, s->pktout);
7185 s->type = AUTH_TYPE_NONE;
7187 unsigned char *pkblob, *sigblob, *sigdata;
7188 int pkblob_len, sigblob_len, sigdata_len;
7192 * We have loaded the private key and the server
7193 * has announced that it's willing to accept it.
7194 * Hallelujah. Generate a signature and send it.
7196 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7197 ssh2_pkt_addstring(s->pktout, s->username);
7198 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7199 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7200 ssh2_pkt_addbool(s->pktout, TRUE);
7201 ssh2_pkt_addstring(s->pktout, key->alg->name);
7202 pkblob = key->alg->public_blob(key->data, &pkblob_len);
7203 ssh2_pkt_addstring_start(s->pktout);
7204 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
7207 * The data to be signed is:
7211 * followed by everything so far placed in the
7214 sigdata_len = s->pktout->length - 5 + 4 +
7215 ssh->v2_session_id_len;
7216 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7218 sigdata = snewn(sigdata_len, unsigned char);
7220 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7221 PUT_32BIT(sigdata+p, ssh->v2_session_id_len);
7224 memcpy(sigdata+p, ssh->v2_session_id,
7225 ssh->v2_session_id_len);
7226 p += ssh->v2_session_id_len;
7227 memcpy(sigdata+p, s->pktout->data + 5,
7228 s->pktout->length - 5);
7229 p += s->pktout->length - 5;
7230 assert(p == sigdata_len);
7231 sigblob = key->alg->sign(key->data, (char *)sigdata,
7232 sigdata_len, &sigblob_len);
7233 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7234 sigblob, sigblob_len);
7239 ssh2_pkt_send(ssh, s->pktout);
7240 s->type = AUTH_TYPE_PUBLICKEY;
7241 key->alg->freekey(key->data);
7243 } else if (s->method == AUTH_PASSWORD) {
7245 * We pad out the password packet to 256 bytes to make
7246 * it harder for an attacker to find the length of the
7249 * Anyone using a password longer than 256 bytes
7250 * probably doesn't have much to worry about from
7251 * people who find out how long their password is!
7253 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7254 s->pktout->forcepad = 256;
7255 ssh2_pkt_addstring(s->pktout, s->username);
7256 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7257 ssh2_pkt_addstring(s->pktout, "password");
7258 ssh2_pkt_addbool(s->pktout, FALSE);
7259 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7260 ssh2_pkt_addstring(s->pktout, s->password);
7261 memset(s->password, 0, sizeof(s->password));
7262 end_log_omission(ssh, s->pktout);
7263 ssh2_pkt_send(ssh, s->pktout);
7264 logevent("Sent password");
7265 s->type = AUTH_TYPE_PASSWORD;
7266 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7267 if (s->curr_prompt == 0) {
7268 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7269 s->pktout->forcepad = 256;
7270 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7272 if (s->need_pw) { /* only add pw if we just got one! */
7273 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7274 ssh2_pkt_addstring(s->pktout, s->password);
7275 memset(s->password, 0, sizeof(s->password));
7276 end_log_omission(ssh, s->pktout);
7279 if (s->curr_prompt >= s->num_prompts) {
7280 ssh2_pkt_send(ssh, s->pktout);
7283 * If there are prompts remaining, we set
7284 * `gotit' so that we won't attempt to get
7285 * another packet. Then we go back round the
7286 * loop and will end up retrieving another
7287 * prompt out of the existing packet. Funky or
7292 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7294 ssh_disconnect(ssh, NULL,
7295 "No supported authentication methods available",
7296 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7302 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7305 * Now the connection protocol has started, one way or another.
7308 ssh->channels = newtree234(ssh_channelcmp);
7311 * Set up handlers for some connection protocol messages, so we
7312 * don't have to handle them repeatedly in this coroutine.
7314 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7315 ssh2_msg_channel_window_adjust;
7316 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7317 ssh2_msg_global_request;
7320 * Create the main session channel.
7322 if (!ssh->cfg.ssh_no_shell) {
7323 ssh->mainchan = snew(struct ssh_channel);
7324 ssh->mainchan->ssh = ssh;
7325 ssh->mainchan->localid = alloc_channel_id(ssh);
7326 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7327 ssh2_pkt_addstring(s->pktout, "session");
7328 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7329 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7330 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7331 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7332 ssh2_pkt_send(ssh, s->pktout);
7333 crWaitUntilV(pktin);
7334 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7335 bombout(("Server refused to open a session"));
7337 /* FIXME: error data comes back in FAILURE packet */
7339 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7340 bombout(("Server's channel confirmation cited wrong channel"));
7343 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7344 ssh->mainchan->halfopen = FALSE;
7345 ssh->mainchan->type = CHAN_MAINSESSION;
7346 ssh->mainchan->closes = 0;
7347 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7348 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7349 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7350 add234(ssh->channels, ssh->mainchan);
7351 update_specials_menu(ssh->frontend);
7352 logevent("Opened channel for session");
7354 ssh->mainchan = NULL;
7357 * Now we have a channel, make dispatch table entries for
7358 * general channel-based messages.
7360 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7361 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7362 ssh2_msg_channel_data;
7363 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7364 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7365 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7366 ssh2_msg_channel_open_confirmation;
7367 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7368 ssh2_msg_channel_open_failure;
7369 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7370 ssh2_msg_channel_request;
7371 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7372 ssh2_msg_channel_open;
7375 * Potentially enable X11 forwarding.
7377 if (ssh->mainchan && ssh->cfg.x11_forward) {
7378 char proto[20], data[64];
7379 logevent("Requesting X11 forwarding");
7380 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7381 data, sizeof(data), ssh->cfg.x11_auth);
7382 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7383 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7384 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7385 ssh2_pkt_addstring(s->pktout, "x11-req");
7386 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7387 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7388 ssh2_pkt_addstring(s->pktout, proto);
7390 * Note that while we blank the X authentication data here, we don't
7391 * take any special action to blank the start of an X11 channel,
7392 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7393 * without having session blanking enabled is likely to leak your
7394 * cookie into the log.
7396 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7397 ssh2_pkt_addstring(s->pktout, data);
7398 end_log_omission(ssh, s->pktout);
7399 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7400 ssh2_pkt_send(ssh, s->pktout);
7402 crWaitUntilV(pktin);
7404 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7405 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7406 bombout(("Unexpected response to X11 forwarding request:"
7407 " packet type %d", pktin->type));
7410 logevent("X11 forwarding refused");
7412 logevent("X11 forwarding enabled");
7413 ssh->X11_fwd_enabled = TRUE;
7418 * Enable port forwardings.
7420 ssh_setup_portfwd(ssh, &ssh->cfg);
7423 * Potentially enable agent forwarding.
7425 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7426 logevent("Requesting OpenSSH-style agent forwarding");
7427 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7428 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7429 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7430 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7431 ssh2_pkt_send(ssh, s->pktout);
7433 crWaitUntilV(pktin);
7435 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7436 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7437 bombout(("Unexpected response to agent forwarding request:"
7438 " packet type %d", pktin->type));
7441 logevent("Agent forwarding refused");
7443 logevent("Agent forwarding enabled");
7444 ssh->agentfwd_enabled = TRUE;
7449 * Now allocate a pty for the session.
7451 if (ssh->mainchan && !ssh->cfg.nopty) {
7452 /* Unpick the terminal-speed string. */
7453 /* XXX perhaps we should allow no speeds to be sent. */
7454 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7455 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7456 /* Build the pty request. */
7457 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7458 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7459 ssh2_pkt_addstring(s->pktout, "pty-req");
7460 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7461 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7462 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7463 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7464 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7465 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7466 ssh2_pkt_addstring_start(s->pktout);
7467 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7468 ssh2_send_ttymode, (void *)s->pktout);
7469 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
7470 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7471 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
7472 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7473 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7474 ssh2_pkt_send(ssh, s->pktout);
7475 ssh->state = SSH_STATE_INTERMED;
7477 crWaitUntilV(pktin);
7479 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7480 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7481 bombout(("Unexpected response to pty request:"
7482 " packet type %d", pktin->type));
7485 c_write_str(ssh, "Server refused to allocate pty\r\n");
7486 ssh->editing = ssh->echoing = 1;
7488 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7489 ssh->ospeed, ssh->ispeed);
7492 ssh->editing = ssh->echoing = 1;
7496 * Send environment variables.
7498 * Simplest thing here is to send all the requests at once, and
7499 * then wait for a whole bunch of successes or failures.
7501 if (ssh->mainchan && *ssh->cfg.environmt) {
7502 char *e = ssh->cfg.environmt;
7503 char *var, *varend, *val;
7509 while (*e && *e != '\t') e++;
7511 if (*e == '\t') e++;
7516 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7517 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7518 ssh2_pkt_addstring(s->pktout, "env");
7519 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7520 ssh2_pkt_addstring_start(s->pktout);
7521 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7522 ssh2_pkt_addstring(s->pktout, val);
7523 ssh2_pkt_send(ssh, s->pktout);
7528 logeventf(ssh, "Sent %d environment variables", s->num_env);
7531 s->env_left = s->num_env;
7533 while (s->env_left > 0) {
7534 crWaitUntilV(pktin);
7536 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7537 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7538 bombout(("Unexpected response to environment request:"
7539 " packet type %d", pktin->type));
7549 if (s->env_ok == s->num_env) {
7550 logevent("All environment variables successfully set");
7551 } else if (s->env_ok == 0) {
7552 logevent("All environment variables refused");
7553 c_write_str(ssh, "Server refused to set environment variables\r\n");
7555 logeventf(ssh, "%d environment variables refused",
7556 s->num_env - s->env_ok);
7557 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7562 * Start a shell or a remote command. We may have to attempt
7563 * this twice if the config data has provided a second choice
7566 if (ssh->mainchan) while (1) {
7570 if (ssh->fallback_cmd) {
7571 subsys = ssh->cfg.ssh_subsys2;
7572 cmd = ssh->cfg.remote_cmd_ptr2;
7574 subsys = ssh->cfg.ssh_subsys;
7575 cmd = ssh->cfg.remote_cmd_ptr;
7576 if (!cmd) cmd = ssh->cfg.remote_cmd;
7579 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7580 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7582 ssh2_pkt_addstring(s->pktout, "subsystem");
7583 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7584 ssh2_pkt_addstring(s->pktout, cmd);
7586 ssh2_pkt_addstring(s->pktout, "exec");
7587 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7588 ssh2_pkt_addstring(s->pktout, cmd);
7590 ssh2_pkt_addstring(s->pktout, "shell");
7591 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7593 ssh2_pkt_send(ssh, s->pktout);
7595 crWaitUntilV(pktin);
7597 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7598 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7599 bombout(("Unexpected response to shell/command request:"
7600 " packet type %d", pktin->type));
7604 * We failed to start the command. If this is the
7605 * fallback command, we really are finished; if it's
7606 * not, and if the fallback command exists, try falling
7607 * back to it before complaining.
7609 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7610 logevent("Primary command failed; attempting fallback");
7611 ssh->fallback_cmd = TRUE;
7614 bombout(("Server refused to start a shell/command"));
7617 logevent("Started a shell/command");
7622 ssh->state = SSH_STATE_SESSION;
7623 if (ssh->size_needed)
7624 ssh_size(ssh, ssh->term_width, ssh->term_height);
7625 if (ssh->eof_needed)
7626 ssh_special(ssh, TS_EOF);
7632 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7637 s->try_send = FALSE;
7641 * _All_ the connection-layer packets we expect to
7642 * receive are now handled by the dispatch table.
7643 * Anything that reaches here must be bogus.
7646 bombout(("Strange packet received: type %d", pktin->type));
7648 } else if (ssh->mainchan) {
7650 * We have spare data. Add it to the channel buffer.
7652 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7657 struct ssh_channel *c;
7659 * Try to send data on all channels if we can.
7661 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7662 ssh2_try_send_and_unthrottle(c);
7670 * Handlers for SSH-2 messages that might arrive at any moment.
7672 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7674 /* log reason code in disconnect message */
7676 int nowlen, reason, msglen;
7678 reason = ssh_pkt_getuint32(pktin);
7679 ssh_pkt_getstring(pktin, &msg, &msglen);
7681 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7682 buf = dupprintf("Received disconnect message (%s)",
7683 ssh2_disconnect_reasons[reason]);
7685 buf = dupprintf("Received disconnect message (unknown"
7686 " type %d)", reason);
7690 buf = dupprintf("Disconnection message text: %n%.*s",
7691 &nowlen, msglen, msg);
7693 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7695 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7696 ssh2_disconnect_reasons[reason] : "unknown",
7701 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7703 /* log the debug message */
7708 /* XXX maybe we should actually take notice of this */
7709 always_display = ssh2_pkt_getbool(pktin);
7710 ssh_pkt_getstring(pktin, &msg, &msglen);
7712 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7715 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7717 struct Packet *pktout;
7718 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7719 ssh2_pkt_adduint32(pktout, pktin->sequence);
7721 * UNIMPLEMENTED messages MUST appear in the same order as the
7722 * messages they respond to. Hence, never queue them.
7724 ssh2_pkt_send_noqueue(ssh, pktout);
7728 * Handle the top-level SSH-2 protocol.
7730 static void ssh2_protocol_setup(Ssh ssh)
7735 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7737 for (i = 0; i < 256; i++)
7738 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7741 * Any message we actually understand, we set to NULL so that
7742 * the coroutines will get it.
7744 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7745 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7746 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7747 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7748 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7749 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7750 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7751 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7752 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7753 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7754 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7755 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7756 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7757 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7758 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7759 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7760 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7761 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7762 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7763 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7764 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7765 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7766 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7767 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7768 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7769 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7770 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7771 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7772 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7773 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7774 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7775 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7776 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7779 * These special message types we install handlers for.
7781 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7782 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
7783 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7786 static void ssh2_timer(void *ctx, long now)
7790 if (ssh->state == SSH_STATE_CLOSED)
7793 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7794 now - ssh->next_rekey >= 0) {
7795 do_ssh2_transport(ssh, "timeout", -1, NULL);
7799 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7800 struct Packet *pktin)
7802 unsigned char *in = (unsigned char *)vin;
7803 if (ssh->state == SSH_STATE_CLOSED)
7807 ssh->incoming_data_size += pktin->encrypted_len;
7808 if (!ssh->kex_in_progress &&
7809 ssh->max_data_size != 0 &&
7810 ssh->incoming_data_size > ssh->max_data_size)
7811 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7814 if (pktin && ssh->packet_dispatch[pktin->type]) {
7815 ssh->packet_dispatch[pktin->type](ssh, pktin);
7819 if (!ssh->protocol_initial_phase_done ||
7820 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7821 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7822 !ssh->protocol_initial_phase_done) {
7823 ssh->protocol_initial_phase_done = TRUE;
7825 * Allow authconn to initialise itself.
7827 do_ssh2_authconn(ssh, NULL, 0, NULL);
7830 do_ssh2_authconn(ssh, in, inlen, pktin);
7835 * Called to set up the connection.
7837 * Returns an error message, or NULL on success.
7839 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7841 char *host, int port, char **realhost, int nodelay,
7847 ssh = snew(struct ssh_tag);
7848 ssh->cfg = *cfg; /* STRUCTURE COPY */
7849 ssh->version = 0; /* when not ready yet */
7852 ssh->v1_cipher_ctx = NULL;
7853 ssh->crcda_ctx = NULL;
7854 ssh->cscipher = NULL;
7855 ssh->cs_cipher_ctx = NULL;
7856 ssh->sccipher = NULL;
7857 ssh->sc_cipher_ctx = NULL;
7859 ssh->cs_mac_ctx = NULL;
7861 ssh->sc_mac_ctx = NULL;
7863 ssh->cs_comp_ctx = NULL;
7865 ssh->sc_comp_ctx = NULL;
7867 ssh->kex_ctx = NULL;
7868 ssh->hostkey = NULL;
7870 ssh->close_expected = FALSE;
7871 ssh->clean_exit = FALSE;
7872 ssh->state = SSH_STATE_PREPACKET;
7873 ssh->size_needed = FALSE;
7874 ssh->eof_needed = FALSE;
7877 ssh->deferred_send_data = NULL;
7878 ssh->deferred_len = 0;
7879 ssh->deferred_size = 0;
7880 ssh->fallback_cmd = 0;
7882 ssh->x11auth = NULL;
7883 ssh->v1_compressing = FALSE;
7884 ssh->v2_outgoing_sequence = 0;
7885 ssh->ssh1_rdpkt_crstate = 0;
7886 ssh->ssh2_rdpkt_crstate = 0;
7887 ssh->do_ssh_init_crstate = 0;
7888 ssh->ssh_gotdata_crstate = 0;
7889 ssh->do_ssh1_connection_crstate = 0;
7890 ssh->do_ssh1_login_crstate = 0;
7891 ssh->do_ssh2_transport_crstate = 0;
7892 ssh->do_ssh2_authconn_crstate = 0;
7893 ssh->do_ssh_init_state = NULL;
7894 ssh->do_ssh1_login_state = NULL;
7895 ssh->do_ssh2_transport_state = NULL;
7896 ssh->do_ssh2_authconn_state = NULL;
7899 ssh->mainchan = NULL;
7900 ssh->throttled_all = 0;
7901 ssh->v1_stdout_throttling = 0;
7903 ssh->queuelen = ssh->queuesize = 0;
7904 ssh->queueing = FALSE;
7905 ssh->qhead = ssh->qtail = NULL;
7906 ssh->deferred_rekey_reason = NULL;
7907 bufchain_init(&ssh->queued_incoming_data);
7908 ssh->frozen = FALSE;
7910 *backend_handle = ssh;
7913 if (crypto_startup() == 0)
7914 return "Microsoft high encryption pack not installed!";
7917 ssh->frontend = frontend_handle;
7918 ssh->term_width = ssh->cfg.width;
7919 ssh->term_height = ssh->cfg.height;
7921 ssh->channels = NULL;
7922 ssh->rportfwds = NULL;
7923 ssh->portfwds = NULL;
7928 ssh->v1_throttle_count = 0;
7929 ssh->overall_bufsize = 0;
7930 ssh->fallback_cmd = 0;
7932 ssh->protocol = NULL;
7934 ssh->protocol_initial_phase_done = FALSE;
7938 ssh->incoming_data_size = ssh->outgoing_data_size =
7939 ssh->deferred_data_size = 0L;
7940 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7941 ssh->kex_in_progress = FALSE;
7943 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7952 static void ssh_free(void *handle)
7954 Ssh ssh = (Ssh) handle;
7955 struct ssh_channel *c;
7956 struct ssh_rportfwd *pf;
7958 if (ssh->v1_cipher_ctx)
7959 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7960 if (ssh->cs_cipher_ctx)
7961 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7962 if (ssh->sc_cipher_ctx)
7963 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7964 if (ssh->cs_mac_ctx)
7965 ssh->csmac->free_context(ssh->cs_mac_ctx);
7966 if (ssh->sc_mac_ctx)
7967 ssh->scmac->free_context(ssh->sc_mac_ctx);
7968 if (ssh->cs_comp_ctx) {
7970 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7972 zlib_compress_cleanup(ssh->cs_comp_ctx);
7974 if (ssh->sc_comp_ctx) {
7976 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7978 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7981 dh_cleanup(ssh->kex_ctx);
7982 sfree(ssh->savedhost);
7984 while (ssh->queuelen-- > 0)
7985 ssh_free_packet(ssh->queue[ssh->queuelen]);
7988 while (ssh->qhead) {
7989 struct queued_handler *qh = ssh->qhead;
7990 ssh->qhead = qh->next;
7993 ssh->qhead = ssh->qtail = NULL;
7995 if (ssh->channels) {
7996 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7999 if (c->u.x11.s != NULL)
8000 x11_close(c->u.x11.s);
8003 if (c->u.pfd.s != NULL)
8004 pfd_close(c->u.pfd.s);
8009 freetree234(ssh->channels);
8010 ssh->channels = NULL;
8013 if (ssh->rportfwds) {
8014 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
8016 freetree234(ssh->rportfwds);
8017 ssh->rportfwds = NULL;
8019 sfree(ssh->deferred_send_data);
8021 x11_free_auth(ssh->x11auth);
8022 sfree(ssh->do_ssh_init_state);
8023 sfree(ssh->do_ssh1_login_state);
8024 sfree(ssh->do_ssh2_transport_state);
8025 sfree(ssh->do_ssh2_authconn_state);
8028 if (ssh->crcda_ctx) {
8029 crcda_free_context(ssh->crcda_ctx);
8030 ssh->crcda_ctx = NULL;
8033 ssh_do_close(ssh, TRUE);
8034 expire_timer_context(ssh);
8036 pinger_free(ssh->pinger);
8037 bufchain_clear(&ssh->queued_incoming_data);
8044 * Reconfigure the SSH backend.
8046 static void ssh_reconfig(void *handle, Config *cfg)
8048 Ssh ssh = (Ssh) handle;
8049 char *rekeying = NULL, rekey_mandatory = FALSE;
8050 unsigned long old_max_data_size;
8052 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8054 ssh_setup_portfwd(ssh, cfg);
8056 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8057 cfg->ssh_rekey_time != 0) {
8058 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8059 long now = GETTICKCOUNT();
8061 if (new_next - now < 0) {
8062 rekeying = "timeout shortened";
8064 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8068 old_max_data_size = ssh->max_data_size;
8069 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8070 if (old_max_data_size != ssh->max_data_size &&
8071 ssh->max_data_size != 0) {
8072 if (ssh->outgoing_data_size > ssh->max_data_size ||
8073 ssh->incoming_data_size > ssh->max_data_size)
8074 rekeying = "data limit lowered";
8077 if (ssh->cfg.compression != cfg->compression) {
8078 rekeying = "compression setting changed";
8079 rekey_mandatory = TRUE;
8082 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8083 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8084 sizeof(ssh->cfg.ssh_cipherlist))) {
8085 rekeying = "cipher settings changed";
8086 rekey_mandatory = TRUE;
8089 ssh->cfg = *cfg; /* STRUCTURE COPY */
8092 if (!ssh->kex_in_progress) {
8093 do_ssh2_transport(ssh, rekeying, -1, NULL);
8094 } else if (rekey_mandatory) {
8095 ssh->deferred_rekey_reason = rekeying;
8101 * Called to send data down the SSH connection.
8103 static int ssh_send(void *handle, char *buf, int len)
8105 Ssh ssh = (Ssh) handle;
8107 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8110 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8112 return ssh_sendbuffer(ssh);
8116 * Called to query the current amount of buffered stdin data.
8118 static int ssh_sendbuffer(void *handle)
8120 Ssh ssh = (Ssh) handle;
8123 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8127 * If the SSH socket itself has backed up, add the total backup
8128 * size on that to any individual buffer on the stdin channel.
8131 if (ssh->throttled_all)
8132 override_value = ssh->overall_bufsize;
8134 if (ssh->version == 1) {
8135 return override_value;
8136 } else if (ssh->version == 2) {
8137 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8138 return override_value;
8140 return (override_value +
8141 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8148 * Called to set the size of the window from SSH's POV.
8150 static void ssh_size(void *handle, int width, int height)
8152 Ssh ssh = (Ssh) handle;
8153 struct Packet *pktout;
8155 ssh->term_width = width;
8156 ssh->term_height = height;
8158 switch (ssh->state) {
8159 case SSH_STATE_BEFORE_SIZE:
8160 case SSH_STATE_PREPACKET:
8161 case SSH_STATE_CLOSED:
8162 break; /* do nothing */
8163 case SSH_STATE_INTERMED:
8164 ssh->size_needed = TRUE; /* buffer for later */
8166 case SSH_STATE_SESSION:
8167 if (!ssh->cfg.nopty) {
8168 if (ssh->version == 1) {
8169 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8170 PKT_INT, ssh->term_height,
8171 PKT_INT, ssh->term_width,
8172 PKT_INT, 0, PKT_INT, 0, PKT_END);
8173 } else if (ssh->mainchan) {
8174 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8175 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8176 ssh2_pkt_addstring(pktout, "window-change");
8177 ssh2_pkt_addbool(pktout, 0);
8178 ssh2_pkt_adduint32(pktout, ssh->term_width);
8179 ssh2_pkt_adduint32(pktout, ssh->term_height);
8180 ssh2_pkt_adduint32(pktout, 0);
8181 ssh2_pkt_adduint32(pktout, 0);
8182 ssh2_pkt_send(ssh, pktout);
8190 * Return a list of the special codes that make sense in this
8193 static const struct telnet_special *ssh_get_specials(void *handle)
8195 static const struct telnet_special ssh1_ignore_special[] = {
8196 {"IGNORE message", TS_NOP}
8198 static const struct telnet_special ssh2_transport_specials[] = {
8199 {"IGNORE message", TS_NOP},
8200 {"Repeat key exchange", TS_REKEY},
8202 static const struct telnet_special ssh2_session_specials[] = {
8205 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8206 * They include all the ISO C signals, but are a subset of the POSIX
8207 * required signals. */
8208 {"SIGINT (Interrupt)", TS_SIGINT},
8209 {"SIGTERM (Terminate)", TS_SIGTERM},
8210 {"SIGKILL (Kill)", TS_SIGKILL},
8211 {"SIGQUIT (Quit)", TS_SIGQUIT},
8212 {"SIGHUP (Hangup)", TS_SIGHUP},
8213 {"More signals", TS_SUBMENU},
8214 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8215 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8216 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8217 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8220 static const struct telnet_special specials_end[] = {
8223 /* XXX review this length for any changes: */
8224 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8225 lenof(ssh2_session_specials) +
8226 lenof(specials_end)];
8227 Ssh ssh = (Ssh) handle;
8229 #define ADD_SPECIALS(name) \
8231 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8232 memcpy(&ssh_specials[i], name, sizeof name); \
8236 if (ssh->version == 1) {
8237 /* Don't bother offering IGNORE if we've decided the remote
8238 * won't cope with it, since we wouldn't bother sending it if
8240 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8241 ADD_SPECIALS(ssh1_ignore_special);
8242 } else if (ssh->version == 2) {
8243 ADD_SPECIALS(ssh2_transport_specials);
8245 ADD_SPECIALS(ssh2_session_specials);
8246 } /* else we're not ready yet */
8249 ADD_SPECIALS(specials_end);
8250 return ssh_specials;
8258 * Send special codes. TS_EOF is useful for `plink', so you
8259 * can send an EOF and collect resulting output (e.g. `plink
8262 static void ssh_special(void *handle, Telnet_Special code)
8264 Ssh ssh = (Ssh) handle;
8265 struct Packet *pktout;
8267 if (code == TS_EOF) {
8268 if (ssh->state != SSH_STATE_SESSION) {
8270 * Buffer the EOF in case we are pre-SESSION, so we can
8271 * send it as soon as we reach SESSION.
8274 ssh->eof_needed = TRUE;
8277 if (ssh->version == 1) {
8278 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8279 } else if (ssh->mainchan) {
8280 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8281 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8282 ssh2_pkt_send(ssh, pktout);
8283 ssh->send_ok = 0; /* now stop trying to read from stdin */
8285 logevent("Sent EOF message");
8286 } else if (code == TS_PING || code == TS_NOP) {
8287 if (ssh->state == SSH_STATE_CLOSED
8288 || ssh->state == SSH_STATE_PREPACKET) return;
8289 if (ssh->version == 1) {
8290 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8291 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8293 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8294 ssh2_pkt_addstring_start(pktout);
8295 ssh2_pkt_send_noqueue(ssh, pktout);
8297 } else if (code == TS_REKEY) {
8298 if (!ssh->kex_in_progress && ssh->version == 2) {
8299 do_ssh2_transport(ssh, "at user request", -1, NULL);
8301 } else if (code == TS_BRK) {
8302 if (ssh->state == SSH_STATE_CLOSED
8303 || ssh->state == SSH_STATE_PREPACKET) return;
8304 if (ssh->version == 1) {
8305 logevent("Unable to send BREAK signal in SSH-1");
8306 } else if (ssh->mainchan) {
8307 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8308 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8309 ssh2_pkt_addstring(pktout, "break");
8310 ssh2_pkt_addbool(pktout, 0);
8311 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8312 ssh2_pkt_send(ssh, pktout);
8315 /* Is is a POSIX signal? */
8316 char *signame = NULL;
8317 if (code == TS_SIGABRT) signame = "ABRT";
8318 if (code == TS_SIGALRM) signame = "ALRM";
8319 if (code == TS_SIGFPE) signame = "FPE";
8320 if (code == TS_SIGHUP) signame = "HUP";
8321 if (code == TS_SIGILL) signame = "ILL";
8322 if (code == TS_SIGINT) signame = "INT";
8323 if (code == TS_SIGKILL) signame = "KILL";
8324 if (code == TS_SIGPIPE) signame = "PIPE";
8325 if (code == TS_SIGQUIT) signame = "QUIT";
8326 if (code == TS_SIGSEGV) signame = "SEGV";
8327 if (code == TS_SIGTERM) signame = "TERM";
8328 if (code == TS_SIGUSR1) signame = "USR1";
8329 if (code == TS_SIGUSR2) signame = "USR2";
8330 /* The SSH-2 protocol does in principle support arbitrary named
8331 * signals, including signame@domain, but we don't support those. */
8333 /* It's a signal. */
8334 if (ssh->version == 2 && ssh->mainchan) {
8335 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8336 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8337 ssh2_pkt_addstring(pktout, "signal");
8338 ssh2_pkt_addbool(pktout, 0);
8339 ssh2_pkt_addstring(pktout, signame);
8340 ssh2_pkt_send(ssh, pktout);
8341 logeventf(ssh, "Sent signal SIG%s", signame);
8344 /* Never heard of it. Do nothing */
8349 void *new_sock_channel(void *handle, Socket s)
8351 Ssh ssh = (Ssh) handle;
8352 struct ssh_channel *c;
8353 c = snew(struct ssh_channel);
8358 c->localid = alloc_channel_id(ssh);
8360 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8362 bufchain_init(&c->v.v2.outbuffer);
8363 add234(ssh->channels, c);
8369 * This is called when stdout/stderr (the entity to which
8370 * from_backend sends data) manages to clear some backlog.
8372 static void ssh_unthrottle(void *handle, int bufsize)
8374 Ssh ssh = (Ssh) handle;
8375 if (ssh->version == 1) {
8376 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8377 ssh->v1_stdout_throttling = 0;
8378 ssh1_throttle(ssh, -1);
8381 if (ssh->mainchan && ssh->mainchan->closes == 0)
8382 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8386 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8388 struct ssh_channel *c = (struct ssh_channel *)channel;
8390 struct Packet *pktout;
8392 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8394 if (ssh->version == 1) {
8395 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8396 PKT_INT, c->localid,
8399 /* PKT_STR, <org:orgport>, */
8402 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8403 ssh2_pkt_addstring(pktout, "direct-tcpip");
8404 ssh2_pkt_adduint32(pktout, c->localid);
8405 c->v.v2.locwindow = OUR_V2_WINSIZE;
8406 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8407 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8408 ssh2_pkt_addstring(pktout, hostname);
8409 ssh2_pkt_adduint32(pktout, port);
8411 * We make up values for the originator data; partly it's
8412 * too much hassle to keep track, and partly I'm not
8413 * convinced the server should be told details like that
8414 * about my local network configuration.
8416 ssh2_pkt_addstring(pktout, "client-side-connection");
8417 ssh2_pkt_adduint32(pktout, 0);
8418 ssh2_pkt_send(ssh, pktout);
8422 static Socket ssh_socket(void *handle)
8424 Ssh ssh = (Ssh) handle;
8428 static int ssh_sendok(void *handle)
8430 Ssh ssh = (Ssh) handle;
8431 return ssh->send_ok;
8434 static int ssh_ldisc(void *handle, int option)
8436 Ssh ssh = (Ssh) handle;
8437 if (option == LD_ECHO)
8438 return ssh->echoing;
8439 if (option == LD_EDIT)
8440 return ssh->editing;
8444 static void ssh_provide_ldisc(void *handle, void *ldisc)
8446 Ssh ssh = (Ssh) handle;
8450 static void ssh_provide_logctx(void *handle, void *logctx)
8452 Ssh ssh = (Ssh) handle;
8453 ssh->logctx = logctx;
8456 static int ssh_return_exitcode(void *handle)
8458 Ssh ssh = (Ssh) handle;
8462 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8466 * cfg_info for SSH is the currently running version of the
8467 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8469 static int ssh_cfg_info(void *handle)
8471 Ssh ssh = (Ssh) handle;
8472 return ssh->version;
8476 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8477 * that fails. This variable is the means by which scp.c can reach
8478 * into the SSH code and find out which one it got.
8480 extern int ssh_fallback_cmd(void *handle)
8482 Ssh ssh = (Ssh) handle;
8483 return ssh->fallback_cmd;
8486 Backend ssh_backend = {
8496 ssh_return_exitcode,