17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_KEX_MASK 0x000F
110 #define SSH2_PKTCTX_PUBLICKEY 0x0010
111 #define SSH2_PKTCTX_PASSWORD 0x0020
112 #define SSH2_PKTCTX_KBDINTER 0x0040
113 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_REKEY 64
167 #define BUG_SSH2_PK_SESSIONID 128
170 * Codes for terminal modes.
171 * Most of these are the same in SSH-1 and SSH-2.
172 * This list is derived from draft-ietf-secsh-connect-25 and
175 static const struct {
176 const char* const mode;
178 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
180 /* "V" prefix discarded for special characters relative to SSH specs */
181 { "INTR", 1, TTY_OP_CHAR },
182 { "QUIT", 2, TTY_OP_CHAR },
183 { "ERASE", 3, TTY_OP_CHAR },
184 { "KILL", 4, TTY_OP_CHAR },
185 { "EOF", 5, TTY_OP_CHAR },
186 { "EOL", 6, TTY_OP_CHAR },
187 { "EOL2", 7, TTY_OP_CHAR },
188 { "START", 8, TTY_OP_CHAR },
189 { "STOP", 9, TTY_OP_CHAR },
190 { "SUSP", 10, TTY_OP_CHAR },
191 { "DSUSP", 11, TTY_OP_CHAR },
192 { "REPRINT", 12, TTY_OP_CHAR },
193 { "WERASE", 13, TTY_OP_CHAR },
194 { "LNEXT", 14, TTY_OP_CHAR },
195 { "FLUSH", 15, TTY_OP_CHAR },
196 { "SWTCH", 16, TTY_OP_CHAR },
197 { "STATUS", 17, TTY_OP_CHAR },
198 { "DISCARD", 18, TTY_OP_CHAR },
199 { "IGNPAR", 30, TTY_OP_BOOL },
200 { "PARMRK", 31, TTY_OP_BOOL },
201 { "INPCK", 32, TTY_OP_BOOL },
202 { "ISTRIP", 33, TTY_OP_BOOL },
203 { "INLCR", 34, TTY_OP_BOOL },
204 { "IGNCR", 35, TTY_OP_BOOL },
205 { "ICRNL", 36, TTY_OP_BOOL },
206 { "IUCLC", 37, TTY_OP_BOOL },
207 { "IXON", 38, TTY_OP_BOOL },
208 { "IXANY", 39, TTY_OP_BOOL },
209 { "IXOFF", 40, TTY_OP_BOOL },
210 { "IMAXBEL", 41, TTY_OP_BOOL },
211 { "ISIG", 50, TTY_OP_BOOL },
212 { "ICANON", 51, TTY_OP_BOOL },
213 { "XCASE", 52, TTY_OP_BOOL },
214 { "ECHO", 53, TTY_OP_BOOL },
215 { "ECHOE", 54, TTY_OP_BOOL },
216 { "ECHOK", 55, TTY_OP_BOOL },
217 { "ECHONL", 56, TTY_OP_BOOL },
218 { "NOFLSH", 57, TTY_OP_BOOL },
219 { "TOSTOP", 58, TTY_OP_BOOL },
220 { "IEXTEN", 59, TTY_OP_BOOL },
221 { "ECHOCTL", 60, TTY_OP_BOOL },
222 { "ECHOKE", 61, TTY_OP_BOOL },
223 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
224 { "OPOST", 70, TTY_OP_BOOL },
225 { "OLCUC", 71, TTY_OP_BOOL },
226 { "ONLCR", 72, TTY_OP_BOOL },
227 { "OCRNL", 73, TTY_OP_BOOL },
228 { "ONOCR", 74, TTY_OP_BOOL },
229 { "ONLRET", 75, TTY_OP_BOOL },
230 { "CS7", 90, TTY_OP_BOOL },
231 { "CS8", 91, TTY_OP_BOOL },
232 { "PARENB", 92, TTY_OP_BOOL },
233 { "PARODD", 93, TTY_OP_BOOL }
236 /* Miscellaneous other tty-related constants. */
237 #define SSH_TTY_OP_END 0
238 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
239 #define SSH1_TTY_OP_ISPEED 192
240 #define SSH1_TTY_OP_OSPEED 193
241 #define SSH2_TTY_OP_ISPEED 128
242 #define SSH2_TTY_OP_OSPEED 129
244 /* Helper functions for parsing tty-related config. */
245 static unsigned int ssh_tty_parse_specchar(char *s)
250 ret = ctrlparse(s, &next);
251 if (!next) ret = s[0];
253 ret = 255; /* special value meaning "don't set" */
257 static unsigned int ssh_tty_parse_boolean(char *s)
259 if (stricmp(s, "yes") == 0 ||
260 stricmp(s, "on") == 0 ||
261 stricmp(s, "true") == 0 ||
262 stricmp(s, "+") == 0)
264 else if (stricmp(s, "no") == 0 ||
265 stricmp(s, "off") == 0 ||
266 stricmp(s, "false") == 0 ||
267 stricmp(s, "-") == 0)
268 return 0; /* false */
270 return (atoi(s) != 0);
273 #define translate(x) if (type == x) return #x
274 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
275 static char *ssh1_pkt_type(int type)
277 translate(SSH1_MSG_DISCONNECT);
278 translate(SSH1_SMSG_PUBLIC_KEY);
279 translate(SSH1_CMSG_SESSION_KEY);
280 translate(SSH1_CMSG_USER);
281 translate(SSH1_CMSG_AUTH_RSA);
282 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
283 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
284 translate(SSH1_CMSG_AUTH_PASSWORD);
285 translate(SSH1_CMSG_REQUEST_PTY);
286 translate(SSH1_CMSG_WINDOW_SIZE);
287 translate(SSH1_CMSG_EXEC_SHELL);
288 translate(SSH1_CMSG_EXEC_CMD);
289 translate(SSH1_SMSG_SUCCESS);
290 translate(SSH1_SMSG_FAILURE);
291 translate(SSH1_CMSG_STDIN_DATA);
292 translate(SSH1_SMSG_STDOUT_DATA);
293 translate(SSH1_SMSG_STDERR_DATA);
294 translate(SSH1_CMSG_EOF);
295 translate(SSH1_SMSG_EXIT_STATUS);
296 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
297 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
298 translate(SSH1_MSG_CHANNEL_DATA);
299 translate(SSH1_MSG_CHANNEL_CLOSE);
300 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
301 translate(SSH1_SMSG_X11_OPEN);
302 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
303 translate(SSH1_MSG_PORT_OPEN);
304 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
305 translate(SSH1_SMSG_AGENT_OPEN);
306 translate(SSH1_MSG_IGNORE);
307 translate(SSH1_CMSG_EXIT_CONFIRMATION);
308 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
309 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
310 translate(SSH1_MSG_DEBUG);
311 translate(SSH1_CMSG_REQUEST_COMPRESSION);
312 translate(SSH1_CMSG_AUTH_TIS);
313 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
314 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
315 translate(SSH1_CMSG_AUTH_CCARD);
316 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
317 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
320 static char *ssh2_pkt_type(int pkt_ctx, int type)
322 translate(SSH2_MSG_DISCONNECT);
323 translate(SSH2_MSG_IGNORE);
324 translate(SSH2_MSG_UNIMPLEMENTED);
325 translate(SSH2_MSG_DEBUG);
326 translate(SSH2_MSG_SERVICE_REQUEST);
327 translate(SSH2_MSG_SERVICE_ACCEPT);
328 translate(SSH2_MSG_KEXINIT);
329 translate(SSH2_MSG_NEWKEYS);
330 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
331 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
332 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
333 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
334 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
335 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
336 translate(SSH2_MSG_USERAUTH_REQUEST);
337 translate(SSH2_MSG_USERAUTH_FAILURE);
338 translate(SSH2_MSG_USERAUTH_SUCCESS);
339 translate(SSH2_MSG_USERAUTH_BANNER);
340 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
341 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
342 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
343 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
344 translate(SSH2_MSG_GLOBAL_REQUEST);
345 translate(SSH2_MSG_REQUEST_SUCCESS);
346 translate(SSH2_MSG_REQUEST_FAILURE);
347 translate(SSH2_MSG_CHANNEL_OPEN);
348 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
349 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
350 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
351 translate(SSH2_MSG_CHANNEL_DATA);
352 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
353 translate(SSH2_MSG_CHANNEL_EOF);
354 translate(SSH2_MSG_CHANNEL_CLOSE);
355 translate(SSH2_MSG_CHANNEL_REQUEST);
356 translate(SSH2_MSG_CHANNEL_SUCCESS);
357 translate(SSH2_MSG_CHANNEL_FAILURE);
363 /* Enumeration values for fields in SSH-1 packets */
365 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
366 /* These values are for communicating relevant semantics of
367 * fields to the packet logging code. */
368 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
372 * Coroutine mechanics for the sillier bits of the code. If these
373 * macros look impenetrable to you, you might find it helpful to
376 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
378 * which explains the theory behind these macros.
380 * In particular, if you are getting `case expression not constant'
381 * errors when building with MS Visual Studio, this is because MS's
382 * Edit and Continue debugging feature causes their compiler to
383 * violate ANSI C. To disable Edit and Continue debugging:
385 * - right-click ssh.c in the FileView
387 * - select the C/C++ tab and the General category
388 * - under `Debug info:', select anything _other_ than `Program
389 * Database for Edit and Continue'.
391 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
394 if (!ssh->t) ssh->t = snew(struct t); \
396 #define crFinish(z) } *crLine = 0; return (z); }
397 #define crFinishV } *crLine = 0; return; }
398 #define crReturn(z) \
400 *crLine =__LINE__; return (z); case __LINE__:;\
404 *crLine=__LINE__; return; case __LINE__:;\
406 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
407 #define crStopV do{ *crLine = 0; return; }while(0)
408 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
409 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
411 typedef struct ssh_tag *Ssh;
414 static struct Packet *ssh1_pkt_init(int pkt_type);
415 static struct Packet *ssh2_pkt_init(int pkt_type);
416 static void ssh_pkt_ensure(struct Packet *, int length);
417 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
418 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
419 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
420 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
421 static void ssh_pkt_addstring_start(struct Packet *);
422 static void ssh_pkt_addstring_str(struct Packet *, char *data);
423 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
424 static void ssh_pkt_addstring(struct Packet *, char *data);
425 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
426 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
427 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
428 static int ssh2_pkt_construct(Ssh, struct Packet *);
429 static void ssh2_pkt_send(Ssh, struct Packet *);
430 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
431 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
432 struct Packet *pktin);
433 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
434 struct Packet *pktin);
437 * Buffer management constants. There are several of these for
438 * various different purposes:
440 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
441 * on a local data stream before we throttle the whole SSH
442 * connection (in SSH-1 only). Throttling the whole connection is
443 * pretty drastic so we set this high in the hope it won't
446 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
447 * on the SSH connection itself before we defensively throttle
448 * _all_ local data streams. This is pretty drastic too (though
449 * thankfully unlikely in SSH-2 since the window mechanism should
450 * ensure that the server never has any need to throttle its end
451 * of the connection), so we set this high as well.
453 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
457 #define SSH1_BUFFER_LIMIT 32768
458 #define SSH_MAX_BACKLOG 32768
459 #define OUR_V2_WINSIZE 16384
460 #define OUR_V2_MAXPKT 0x4000UL
462 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
464 const static struct ssh_mac *macs[] = {
467 const static struct ssh_mac *buggymacs[] = {
468 &ssh_sha1_buggy, &ssh_md5
471 static void *ssh_comp_none_init(void)
475 static void ssh_comp_none_cleanup(void *handle)
478 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
479 unsigned char **outblock, int *outlen)
483 static int ssh_comp_none_disable(void *handle)
487 const static struct ssh_compress ssh_comp_none = {
489 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
490 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
491 ssh_comp_none_disable, NULL
493 extern const struct ssh_compress ssh_zlib;
494 const static struct ssh_compress *compressions[] = {
495 &ssh_zlib, &ssh_comp_none
498 enum { /* channel types */
503 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
507 * 2-3-4 tree storing channels.
510 Ssh ssh; /* pointer back to main context */
511 unsigned remoteid, localid;
513 /* True if we opened this channel but server hasn't confirmed. */
516 * In SSH-1, this value contains four bits:
518 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
519 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
520 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
521 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
523 * A channel is completely finished with when all four bits are set.
527 struct ssh1_data_channel {
530 struct ssh2_data_channel {
532 unsigned remwindow, remmaxpkt;
537 struct ssh_agent_channel {
538 unsigned char *message;
539 unsigned char msglen[4];
540 unsigned lensofar, totallen;
542 struct ssh_x11_channel {
545 struct ssh_pfd_channel {
552 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
553 * use this structure in different ways, reflecting SSH-2's
554 * altogether saner approach to port forwarding.
556 * In SSH-1, you arrange a remote forwarding by sending the server
557 * the remote port number, and the local destination host:port.
558 * When a connection comes in, the server sends you back that
559 * host:port pair, and you connect to it. This is a ready-made
560 * security hole if you're not on the ball: a malicious server
561 * could send you back _any_ host:port pair, so if you trustingly
562 * connect to the address it gives you then you've just opened the
563 * entire inside of your corporate network just by connecting
564 * through it to a dodgy SSH server. Hence, we must store a list of
565 * host:port pairs we _are_ trying to forward to, and reject a
566 * connection request from the server if it's not in the list.
568 * In SSH-2, each side of the connection minds its own business and
569 * doesn't send unnecessary information to the other. You arrange a
570 * remote forwarding by sending the server just the remote port
571 * number. When a connection comes in, the server tells you which
572 * of its ports was connected to; and _you_ have to remember what
573 * local host:port pair went with that port number.
575 * Hence, in SSH-1 this structure is indexed by destination
576 * host:port pair, whereas in SSH-2 it is indexed by source port.
578 struct ssh_portfwd; /* forward declaration */
580 struct ssh_rportfwd {
581 unsigned sport, dport;
584 struct ssh_portfwd *pfrec;
586 #define free_rportfwd(pf) ( \
587 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
590 * Separately to the rportfwd tree (which is for looking up port
591 * open requests from the server), a tree of _these_ structures is
592 * used to keep track of all the currently open port forwardings,
593 * so that we can reconfigure in mid-session if the user requests
597 enum { DESTROY, KEEP, CREATE } status;
599 unsigned sport, dport;
602 struct ssh_rportfwd *remote;
606 #define free_portfwd(pf) ( \
607 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
608 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
611 long length; /* length of `data' actually used */
612 long forcepad; /* SSH-2: force padding to at least this length */
613 int type; /* only used for incoming packets */
614 unsigned long sequence; /* SSH-2 incoming sequence number */
615 unsigned char *data; /* allocated storage */
616 unsigned char *body; /* offset of payload within `data' */
617 long savedpos; /* temporary index into `data' (for strings) */
618 long maxlen; /* amount of storage allocated for `data' */
619 long encrypted_len; /* for SSH-2 total-size counting */
622 * State associated with packet logging
626 struct logblank_t *blanks;
629 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
630 struct Packet *pktin);
631 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
632 struct Packet *pktin);
633 static void ssh1_protocol_setup(Ssh ssh);
634 static void ssh2_protocol_setup(Ssh ssh);
635 static void ssh_size(void *handle, int width, int height);
636 static void ssh_special(void *handle, Telnet_Special);
637 static int ssh2_try_send(struct ssh_channel *c);
638 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
639 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
640 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
641 static int ssh_sendbuffer(void *handle);
642 static int ssh_do_close(Ssh ssh, int notify_exit);
643 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
644 static int ssh2_pkt_getbool(struct Packet *pkt);
645 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
646 static void ssh2_timer(void *ctx, long now);
647 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
648 struct Packet *pktin);
650 struct rdpkt1_state_tag {
651 long len, pad, biglen, to_read;
652 unsigned long realcrc, gotcrc;
656 struct Packet *pktin;
659 struct rdpkt2_state_tag {
660 long len, pad, payload, packetlen, maclen;
663 unsigned long incoming_sequence;
664 struct Packet *pktin;
667 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
668 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
670 struct queued_handler;
671 struct queued_handler {
673 chandler_fn_t handler;
675 struct queued_handler *next;
679 const struct plug_function_table *fn;
680 /* the above field _must_ be first in the structure */
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[20];
714 int echoing, editing;
718 int ospeed, ispeed; /* temporaries */
719 int term_width, term_height;
721 tree234 *channels; /* indexed by local id */
722 struct ssh_channel *mainchan; /* primary session channel */
727 tree234 *rportfwds, *portfwds;
731 SSH_STATE_BEFORE_SIZE,
737 int size_needed, eof_needed;
739 struct Packet **queue;
740 int queuelen, queuesize;
742 unsigned char *deferred_send_data;
743 int deferred_len, deferred_size;
746 * Gross hack: pscp will try to start SFTP but fall back to
747 * scp1 if that fails. This variable is the means by which
748 * scp.c can reach into the SSH code and find out which one it
753 bufchain banner; /* accumulates banners during do_ssh2_authconn */
755 * Used for username and password input.
757 char *userpass_input_buffer;
758 int userpass_input_buflen;
759 int userpass_input_bufpos;
760 int userpass_input_echo;
767 int v1_throttle_count;
770 int v1_stdout_throttling;
771 unsigned long v2_outgoing_sequence;
773 int ssh1_rdpkt_crstate;
774 int ssh2_rdpkt_crstate;
775 int do_ssh_init_crstate;
776 int ssh_gotdata_crstate;
777 int do_ssh1_login_crstate;
778 int do_ssh1_connection_crstate;
779 int do_ssh2_transport_crstate;
780 int do_ssh2_authconn_crstate;
782 void *do_ssh_init_state;
783 void *do_ssh1_login_state;
784 void *do_ssh2_transport_state;
785 void *do_ssh2_authconn_state;
787 struct rdpkt1_state_tag rdpkt1_state;
788 struct rdpkt2_state_tag rdpkt2_state;
790 /* SSH-1 and SSH-2 use this for different things, but both use it */
791 int protocol_initial_phase_done;
793 void (*protocol) (Ssh ssh, void *vin, int inlen,
795 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
798 * We maintain a full _copy_ of a Config structure here, not
799 * merely a pointer to it. That way, when we're passed a new
800 * one for reconfiguration, we can check the differences and
801 * potentially reconfigure port forwardings etc in mid-session.
806 * Used to transfer data back from async callbacks.
808 void *agent_response;
809 int agent_response_len;
813 * The SSH connection can be set as `frozen', meaning we are
814 * not currently accepting incoming data from the network. This
815 * is slightly more serious than setting the _socket_ as
816 * frozen, because we may already have had data passed to us
817 * from the network which we need to delay processing until
818 * after the freeze is lifted, so we also need a bufchain to
822 bufchain queued_incoming_data;
825 * Dispatch table for packet types that we may have to deal
828 handler_fn_t packet_dispatch[256];
831 * Queues of one-off handler functions for success/failure
832 * indications from a request.
834 struct queued_handler *qhead, *qtail;
837 * This module deals with sending keepalives.
842 * Track incoming and outgoing data sizes and time, for
845 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
846 unsigned long max_data_size;
848 long next_rekey, last_rekey;
849 char *deferred_rekey_reason; /* points to STATIC string; don't free */
852 #define logevent(s) logevent(ssh->frontend, s)
854 /* logevent, only printf-formatted. */
855 static void logeventf(Ssh ssh, const char *fmt, ...)
861 buf = dupvprintf(fmt, ap);
867 #define bombout(msg) \
869 char *text = dupprintf msg; \
870 ssh_do_close(ssh, FALSE); \
872 connection_fatal(ssh->frontend, "%s", text); \
876 /* Functions to leave bits out of the SSH packet log file. */
878 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
880 if (ssh->cfg.logomitpass)
881 pkt->logmode = blanktype;
884 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
886 if (ssh->cfg.logomitdata)
887 pkt->logmode = blanktype;
890 static void end_log_omission(Ssh ssh, struct Packet *pkt)
892 pkt->logmode = PKTLOG_EMIT;
895 /* Helper function for common bits of parsing cfg.ttymodes. */
896 static void parse_ttymodes(Ssh ssh, char *modes,
897 void (*do_mode)(void *data, char *mode, char *val),
901 char *t = strchr(modes, '\t');
902 char *m = snewn(t-modes+1, char);
904 strncpy(m, modes, t-modes);
907 val = get_ttymode(ssh->frontend, m);
911 do_mode(data, m, val);
914 modes += strlen(modes) + 1;
918 static int ssh_channelcmp(void *av, void *bv)
920 struct ssh_channel *a = (struct ssh_channel *) av;
921 struct ssh_channel *b = (struct ssh_channel *) bv;
922 if (a->localid < b->localid)
924 if (a->localid > b->localid)
928 static int ssh_channelfind(void *av, void *bv)
930 unsigned *a = (unsigned *) av;
931 struct ssh_channel *b = (struct ssh_channel *) bv;
939 static int ssh_rportcmp_ssh1(void *av, void *bv)
941 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
942 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
944 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
945 return i < 0 ? -1 : +1;
946 if (a->dport > b->dport)
948 if (a->dport < b->dport)
953 static int ssh_rportcmp_ssh2(void *av, void *bv)
955 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
956 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
958 if (a->sport > b->sport)
960 if (a->sport < b->sport)
966 * Special form of strcmp which can cope with NULL inputs. NULL is
967 * defined to sort before even the empty string.
969 static int nullstrcmp(const char *a, const char *b)
971 if (a == NULL && b == NULL)
980 static int ssh_portcmp(void *av, void *bv)
982 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
983 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
985 if (a->type > b->type)
987 if (a->type < b->type)
989 if (a->addressfamily > b->addressfamily)
991 if (a->addressfamily < b->addressfamily)
993 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
994 return i < 0 ? -1 : +1;
995 if (a->sport > b->sport)
997 if (a->sport < b->sport)
999 if (a->type != 'D') {
1000 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1001 return i < 0 ? -1 : +1;
1002 if (a->dport > b->dport)
1004 if (a->dport < b->dport)
1010 static int alloc_channel_id(Ssh ssh)
1012 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1013 unsigned low, high, mid;
1015 struct ssh_channel *c;
1018 * First-fit allocation of channel numbers: always pick the
1019 * lowest unused one. To do this, binary-search using the
1020 * counted B-tree to find the largest channel ID which is in a
1021 * contiguous sequence from the beginning. (Precisely
1022 * everything in that sequence must have ID equal to its tree
1023 * index plus CHANNEL_NUMBER_OFFSET.)
1025 tsize = count234(ssh->channels);
1029 while (high - low > 1) {
1030 mid = (high + low) / 2;
1031 c = index234(ssh->channels, mid);
1032 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1033 low = mid; /* this one is fine */
1035 high = mid; /* this one is past it */
1038 * Now low points to either -1, or the tree index of the
1039 * largest ID in the initial sequence.
1042 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1043 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1045 return low + 1 + CHANNEL_NUMBER_OFFSET;
1048 static void c_write(Ssh ssh, const char *buf, int len)
1050 if ((flags & FLAG_STDERR)) {
1052 for (i = 0; i < len; i++)
1054 fputc(buf[i], stderr);
1057 from_backend(ssh->frontend, 1, buf, len);
1060 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1063 for (i = 0; i < len; i++) {
1065 c_write(ssh, "\r\n", 2);
1066 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
1067 c_write(ssh, buf + i, 1);
1071 static void c_write_str(Ssh ssh, const char *buf)
1073 c_write(ssh, buf, strlen(buf));
1076 static void ssh_free_packet(struct Packet *pkt)
1081 static struct Packet *ssh_new_packet(void)
1083 struct Packet *pkt = snew(struct Packet);
1085 pkt->body = pkt->data = NULL;
1087 pkt->logmode = PKTLOG_EMIT;
1095 * Collect incoming data in the incoming packet buffer.
1096 * Decipher and verify the packet when it is completely read.
1097 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1098 * Update the *data and *datalen variables.
1099 * Return a Packet structure when a packet is completed.
1101 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1103 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1105 crBegin(ssh->ssh1_rdpkt_crstate);
1107 st->pktin = ssh_new_packet();
1109 st->pktin->type = 0;
1110 st->pktin->length = 0;
1112 for (st->i = st->len = 0; st->i < 4; st->i++) {
1113 while ((*datalen) == 0)
1115 st->len = (st->len << 8) + **data;
1116 (*data)++, (*datalen)--;
1119 st->pad = 8 - (st->len % 8);
1120 st->biglen = st->len + st->pad;
1121 st->pktin->length = st->len - 5;
1123 if (st->biglen < 0) {
1124 bombout(("Extremely large packet length from server suggests"
1125 " data stream corruption"));
1126 ssh_free_packet(st->pktin);
1130 st->pktin->maxlen = st->biglen;
1131 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1133 st->to_read = st->biglen;
1134 st->p = st->pktin->data;
1135 while (st->to_read > 0) {
1136 st->chunk = st->to_read;
1137 while ((*datalen) == 0)
1139 if (st->chunk > (*datalen))
1140 st->chunk = (*datalen);
1141 memcpy(st->p, *data, st->chunk);
1143 *datalen -= st->chunk;
1145 st->to_read -= st->chunk;
1148 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1149 st->biglen, NULL)) {
1150 bombout(("Network attack (CRC compensation) detected!"));
1151 ssh_free_packet(st->pktin);
1156 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1158 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1159 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1160 if (st->gotcrc != st->realcrc) {
1161 bombout(("Incorrect CRC received on packet"));
1162 ssh_free_packet(st->pktin);
1166 st->pktin->body = st->pktin->data + st->pad + 1;
1167 st->pktin->savedpos = 0;
1169 if (ssh->v1_compressing) {
1170 unsigned char *decompblk;
1172 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1173 st->pktin->body - 1, st->pktin->length + 1,
1174 &decompblk, &decomplen)) {
1175 bombout(("Zlib decompression encountered invalid data"));
1176 ssh_free_packet(st->pktin);
1180 if (st->pktin->maxlen < st->pad + decomplen) {
1181 st->pktin->maxlen = st->pad + decomplen;
1182 st->pktin->data = sresize(st->pktin->data,
1183 st->pktin->maxlen + APIEXTRA,
1185 st->pktin->body = st->pktin->data + st->pad + 1;
1188 memcpy(st->pktin->body - 1, decompblk, decomplen);
1190 st->pktin->length = decomplen - 1;
1193 st->pktin->type = st->pktin->body[-1];
1196 * Log incoming packet, possibly omitting sensitive fields.
1200 struct logblank_t blank;
1201 if (ssh->cfg.logomitdata) {
1202 int do_blank = FALSE, blank_prefix = 0;
1203 /* "Session data" packets - omit the data field */
1204 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1205 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1206 do_blank = TRUE; blank_prefix = 0;
1207 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1208 do_blank = TRUE; blank_prefix = 4;
1211 blank.offset = blank_prefix;
1212 blank.len = st->pktin->length;
1213 blank.type = PKTLOG_OMIT;
1217 log_packet(ssh->logctx,
1218 PKT_INCOMING, st->pktin->type,
1219 ssh1_pkt_type(st->pktin->type),
1220 st->pktin->body, st->pktin->length,
1224 crFinish(st->pktin);
1227 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1229 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1231 crBegin(ssh->ssh2_rdpkt_crstate);
1233 st->pktin = ssh_new_packet();
1235 st->pktin->type = 0;
1236 st->pktin->length = 0;
1238 st->cipherblk = ssh->sccipher->blksize;
1241 if (st->cipherblk < 8)
1244 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1247 * Acquire and decrypt the first block of the packet. This will
1248 * contain the length and padding details.
1250 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1251 while ((*datalen) == 0)
1253 st->pktin->data[st->i] = *(*data)++;
1258 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1259 st->pktin->data, st->cipherblk);
1262 * Now get the length and padding figures.
1264 st->len = GET_32BIT(st->pktin->data);
1265 st->pad = st->pktin->data[4];
1268 * _Completely_ silly lengths should be stomped on before they
1269 * do us any more damage.
1271 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1272 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
1273 bombout(("Incoming packet was garbled on decryption"));
1274 ssh_free_packet(st->pktin);
1279 * This enables us to deduce the payload length.
1281 st->payload = st->len - st->pad - 1;
1283 st->pktin->length = st->payload + 5;
1286 * So now we can work out the total packet length.
1288 st->packetlen = st->len + 4;
1289 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1292 * Allocate memory for the rest of the packet.
1294 st->pktin->maxlen = st->packetlen + st->maclen;
1295 st->pktin->data = sresize(st->pktin->data,
1296 st->pktin->maxlen + APIEXTRA,
1300 * Read and decrypt the remainder of the packet.
1302 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1304 while ((*datalen) == 0)
1306 st->pktin->data[st->i] = *(*data)++;
1309 /* Decrypt everything _except_ the MAC. */
1311 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1312 st->pktin->data + st->cipherblk,
1313 st->packetlen - st->cipherblk);
1315 st->pktin->encrypted_len = st->packetlen;
1321 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1322 st->incoming_sequence)) {
1323 bombout(("Incorrect MAC received on packet"));
1324 ssh_free_packet(st->pktin);
1328 st->pktin->sequence = st->incoming_sequence++;
1331 * Decompress packet payload.
1334 unsigned char *newpayload;
1337 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1338 st->pktin->data + 5, st->pktin->length - 5,
1339 &newpayload, &newlen)) {
1340 if (st->pktin->maxlen < newlen + 5) {
1341 st->pktin->maxlen = newlen + 5;
1342 st->pktin->data = sresize(st->pktin->data,
1343 st->pktin->maxlen + APIEXTRA,
1346 st->pktin->length = 5 + newlen;
1347 memcpy(st->pktin->data + 5, newpayload, newlen);
1352 st->pktin->savedpos = 6;
1353 st->pktin->body = st->pktin->data;
1354 st->pktin->type = st->pktin->data[5];
1357 * Log incoming packet, possibly omitting sensitive fields.
1361 struct logblank_t blank;
1362 if (ssh->cfg.logomitdata) {
1363 int do_blank = FALSE, blank_prefix = 0;
1364 /* "Session data" packets - omit the data field */
1365 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1366 do_blank = TRUE; blank_prefix = 4;
1367 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1368 do_blank = TRUE; blank_prefix = 8;
1371 blank.offset = blank_prefix;
1372 blank.len = (st->pktin->length-6) - blank_prefix;
1373 blank.type = PKTLOG_OMIT;
1377 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1378 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1379 st->pktin->data+6, st->pktin->length-6,
1383 crFinish(st->pktin);
1386 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1388 int pad, biglen, i, pktoffs;
1392 * XXX various versions of SC (including 8.8.4) screw up the
1393 * register allocation in this function and use the same register
1394 * (D6) for len and as a temporary, with predictable results. The
1395 * following sledgehammer prevents this.
1402 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1403 ssh1_pkt_type(pkt->data[12]),
1404 pkt->body, pkt->length - (pkt->body - pkt->data),
1405 pkt->nblanks, pkt->blanks);
1406 sfree(pkt->blanks); pkt->blanks = NULL;
1409 if (ssh->v1_compressing) {
1410 unsigned char *compblk;
1412 zlib_compress_block(ssh->cs_comp_ctx,
1413 pkt->data + 12, pkt->length - 12,
1414 &compblk, &complen);
1415 memcpy(pkt->data + 12, compblk, complen);
1417 pkt->length = complen + 12;
1420 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1422 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1423 pad = 8 - (len % 8);
1425 biglen = len + pad; /* len(padding+type+data+CRC) */
1427 for (i = pktoffs; i < 4+8; i++)
1428 pkt->data[i] = random_byte();
1429 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1430 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1431 PUT_32BIT(pkt->data + pktoffs, len);
1434 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1435 pkt->data + pktoffs + 4, biglen);
1437 if (offset_p) *offset_p = pktoffs;
1438 return biglen + 4; /* len(length+padding+type+data+CRC) */
1441 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1443 int len, backlog, offset;
1444 len = s_wrpkt_prepare(ssh, pkt, &offset);
1445 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1446 if (backlog > SSH_MAX_BACKLOG)
1447 ssh_throttle_all(ssh, 1, backlog);
1448 ssh_free_packet(pkt);
1451 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1454 len = s_wrpkt_prepare(ssh, pkt, &offset);
1455 if (ssh->deferred_len + len > ssh->deferred_size) {
1456 ssh->deferred_size = ssh->deferred_len + len + 128;
1457 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1461 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1462 pkt->data + offset, len);
1463 ssh->deferred_len += len;
1464 ssh_free_packet(pkt);
1468 * Construct a SSH-1 packet with the specified contents.
1469 * (This all-at-once interface used to be the only one, but now SSH-1
1470 * packets can also be constructed incrementally.)
1472 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1478 pkt = ssh1_pkt_init(pkttype);
1480 while ((argtype = va_arg(ap, int)) != PKT_END) {
1481 unsigned char *argp, argchar;
1482 unsigned long argint;
1485 /* Actual fields in the packet */
1487 argint = va_arg(ap, int);
1488 ssh_pkt_adduint32(pkt, argint);
1491 argchar = (unsigned char) va_arg(ap, int);
1492 ssh_pkt_addbyte(pkt, argchar);
1495 argp = va_arg(ap, unsigned char *);
1496 arglen = va_arg(ap, int);
1497 ssh_pkt_adddata(pkt, argp, arglen);
1500 argp = va_arg(ap, unsigned char *);
1501 ssh_pkt_addstring(pkt, argp);
1504 bn = va_arg(ap, Bignum);
1505 ssh1_pkt_addmp(pkt, bn);
1507 /* Tokens for modifications to packet logging */
1509 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1512 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1515 end_log_omission(ssh, pkt);
1523 static void send_packet(Ssh ssh, int pkttype, ...)
1527 va_start(ap, pkttype);
1528 pkt = construct_packet(ssh, pkttype, ap);
1533 static void defer_packet(Ssh ssh, int pkttype, ...)
1537 va_start(ap, pkttype);
1538 pkt = construct_packet(ssh, pkttype, ap);
1540 s_wrpkt_defer(ssh, pkt);
1543 static int ssh_versioncmp(char *a, char *b)
1546 unsigned long av, bv;
1548 av = strtoul(a, &ae, 10);
1549 bv = strtoul(b, &be, 10);
1551 return (av < bv ? -1 : +1);
1556 av = strtoul(ae, &ae, 10);
1557 bv = strtoul(be, &be, 10);
1559 return (av < bv ? -1 : +1);
1564 * Utility routines for putting an SSH-protocol `string' and
1565 * `uint32' into a SHA state.
1567 static void sha_string(SHA_State * s, void *str, int len)
1569 unsigned char lenblk[4];
1570 PUT_32BIT(lenblk, len);
1571 SHA_Bytes(s, lenblk, 4);
1572 SHA_Bytes(s, str, len);
1575 static void sha_uint32(SHA_State * s, unsigned i)
1577 unsigned char intblk[4];
1578 PUT_32BIT(intblk, i);
1579 SHA_Bytes(s, intblk, 4);
1583 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1585 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1587 if (pkt->maxlen < length) {
1588 unsigned char *body = pkt->body;
1589 int offset = body ? pkt->data - body : 0;
1590 pkt->maxlen = length + 256;
1591 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1592 if (body) pkt->body = pkt->data + offset;
1595 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1597 if (pkt->logmode != PKTLOG_EMIT) {
1599 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1601 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1602 (pkt->body - pkt->data);
1603 pkt->blanks[pkt->nblanks-1].len = len;
1604 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1607 ssh_pkt_ensure(pkt, pkt->length);
1608 memcpy(pkt->data + pkt->length - len, data, len);
1610 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1612 ssh_pkt_adddata(pkt, &byte, 1);
1614 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1616 ssh_pkt_adddata(pkt, &value, 1);
1618 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1621 PUT_32BIT(x, value);
1622 ssh_pkt_adddata(pkt, x, 4);
1624 static void ssh_pkt_addstring_start(struct Packet *pkt)
1626 ssh_pkt_adduint32(pkt, 0);
1627 pkt->savedpos = pkt->length;
1629 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1631 ssh_pkt_adddata(pkt, data, strlen(data));
1632 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1634 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1636 ssh_pkt_adddata(pkt, data, len);
1637 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1639 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1641 ssh_pkt_addstring_start(pkt);
1642 ssh_pkt_addstring_str(pkt, data);
1644 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1646 int len = ssh1_bignum_length(b);
1647 unsigned char *data = snewn(len, char);
1648 (void) ssh1_write_bignum(data, b);
1649 ssh_pkt_adddata(pkt, data, len);
1652 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1655 int i, n = (bignum_bitcount(b) + 7) / 8;
1656 p = snewn(n + 1, unsigned char);
1658 for (i = 1; i <= n; i++)
1659 p[i] = bignum_byte(b, n - i);
1661 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1663 memmove(p, p + i, n + 1 - i);
1667 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1671 p = ssh2_mpint_fmt(b, &len);
1672 ssh_pkt_addstring_start(pkt);
1673 ssh_pkt_addstring_data(pkt, (char *)p, len);
1677 static struct Packet *ssh1_pkt_init(int pkt_type)
1679 struct Packet *pkt = ssh_new_packet();
1680 pkt->length = 4 + 8; /* space for length + max padding */
1681 ssh_pkt_addbyte(pkt, pkt_type);
1682 pkt->body = pkt->data + pkt->length;
1686 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1687 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1688 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1689 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1690 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1691 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1692 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1693 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1694 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1696 static struct Packet *ssh2_pkt_init(int pkt_type)
1698 struct Packet *pkt = ssh_new_packet();
1701 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1702 pkt->body = pkt->data + pkt->length;
1707 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1708 * put the MAC on it. Final packet, ready to be sent, is stored in
1709 * pkt->data. Total length is returned.
1711 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1713 int cipherblk, maclen, padding, i;
1716 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1717 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1718 pkt->body, pkt->length - (pkt->body - pkt->data),
1719 pkt->nblanks, pkt->blanks);
1720 sfree(pkt->blanks); pkt->blanks = NULL;
1724 * Compress packet payload.
1727 unsigned char *newpayload;
1730 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1732 &newpayload, &newlen)) {
1734 ssh2_pkt_adddata(pkt, newpayload, newlen);
1740 * Add padding. At least four bytes, and must also bring total
1741 * length (minus MAC) up to a multiple of the block size.
1742 * If pkt->forcepad is set, make sure the packet is at least that size
1745 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1746 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1748 if (pkt->length + padding < pkt->forcepad)
1749 padding = pkt->forcepad - pkt->length;
1751 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1752 assert(padding <= 255);
1753 maclen = ssh->csmac ? ssh->csmac->len : 0;
1754 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1755 pkt->data[4] = padding;
1756 for (i = 0; i < padding; i++)
1757 pkt->data[pkt->length + i] = random_byte();
1758 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1760 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1761 pkt->length + padding,
1762 ssh->v2_outgoing_sequence);
1763 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1766 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1767 pkt->data, pkt->length + padding);
1769 pkt->encrypted_len = pkt->length + padding;
1771 /* Ready-to-send packet starts at pkt->data. We return length. */
1772 return pkt->length + padding + maclen;
1776 * Routines called from the main SSH code to send packets. There
1777 * are quite a few of these, because we have two separate
1778 * mechanisms for delaying the sending of packets:
1780 * - In order to send an IGNORE message and a password message in
1781 * a single fixed-length blob, we require the ability to
1782 * concatenate the encrypted forms of those two packets _into_ a
1783 * single blob and then pass it to our <network.h> transport
1784 * layer in one go. Hence, there's a deferment mechanism which
1785 * works after packet encryption.
1787 * - In order to avoid sending any connection-layer messages
1788 * during repeat key exchange, we have to queue up any such
1789 * outgoing messages _before_ they are encrypted (and in
1790 * particular before they're allocated sequence numbers), and
1791 * then send them once we've finished.
1793 * I call these mechanisms `defer' and `queue' respectively, so as
1794 * to distinguish them reasonably easily.
1796 * The functions send_noqueue() and defer_noqueue() free the packet
1797 * structure they are passed. Every outgoing packet goes through
1798 * precisely one of these functions in its life; packets passed to
1799 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1800 * these or get queued, and then when the queue is later emptied
1801 * the packets are all passed to defer_noqueue().
1803 * When using a CBC-mode cipher, it's necessary to ensure that an
1804 * attacker can't provide data to be encrypted using an IV that they
1805 * know. We ensure this by prefixing each packet that might contain
1806 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1807 * mechanism, so in this case send_noqueue() ends up redirecting to
1808 * defer_noqueue(). If you don't like this inefficiency, don't use
1812 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1813 static void ssh_pkt_defersend(Ssh);
1816 * Send an SSH-2 packet immediately, without queuing or deferring.
1818 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1822 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1823 /* We need to send two packets, so use the deferral mechanism. */
1824 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1825 ssh_pkt_defersend(ssh);
1828 len = ssh2_pkt_construct(ssh, pkt);
1829 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1830 if (backlog > SSH_MAX_BACKLOG)
1831 ssh_throttle_all(ssh, 1, backlog);
1833 ssh->outgoing_data_size += pkt->encrypted_len;
1834 if (!ssh->kex_in_progress &&
1835 ssh->max_data_size != 0 &&
1836 ssh->outgoing_data_size > ssh->max_data_size)
1837 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1839 ssh_free_packet(pkt);
1843 * Defer an SSH-2 packet.
1845 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1848 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1849 ssh->deferred_len == 0 && !noignore) {
1851 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1852 * get encrypted with a known IV.
1854 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1855 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1857 len = ssh2_pkt_construct(ssh, pkt);
1858 if (ssh->deferred_len + len > ssh->deferred_size) {
1859 ssh->deferred_size = ssh->deferred_len + len + 128;
1860 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1864 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1865 ssh->deferred_len += len;
1866 ssh->deferred_data_size += pkt->encrypted_len;
1867 ssh_free_packet(pkt);
1871 * Queue an SSH-2 packet.
1873 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1875 assert(ssh->queueing);
1877 if (ssh->queuelen >= ssh->queuesize) {
1878 ssh->queuesize = ssh->queuelen + 32;
1879 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1882 ssh->queue[ssh->queuelen++] = pkt;
1886 * Either queue or send a packet, depending on whether queueing is
1889 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1892 ssh2_pkt_queue(ssh, pkt);
1894 ssh2_pkt_send_noqueue(ssh, pkt);
1899 * Either queue or defer a packet, depending on whether queueing is
1902 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1905 ssh2_pkt_queue(ssh, pkt);
1907 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1912 * Send the whole deferred data block constructed by
1913 * ssh2_pkt_defer() or SSH-1's defer_packet().
1915 * The expected use of the defer mechanism is that you call
1916 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1917 * not currently queueing, this simply sets up deferred_send_data
1918 * and then sends it. If we _are_ currently queueing, the calls to
1919 * ssh2_pkt_defer() put the deferred packets on to the queue
1920 * instead, and therefore ssh_pkt_defersend() has no deferred data
1921 * to send. Hence, there's no need to make it conditional on
1924 static void ssh_pkt_defersend(Ssh ssh)
1927 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1929 ssh->deferred_len = ssh->deferred_size = 0;
1930 sfree(ssh->deferred_send_data);
1931 ssh->deferred_send_data = NULL;
1932 if (backlog > SSH_MAX_BACKLOG)
1933 ssh_throttle_all(ssh, 1, backlog);
1935 ssh->outgoing_data_size += ssh->deferred_data_size;
1936 if (!ssh->kex_in_progress &&
1937 ssh->max_data_size != 0 &&
1938 ssh->outgoing_data_size > ssh->max_data_size)
1939 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1940 ssh->deferred_data_size = 0;
1944 * Send all queued SSH-2 packets. We send them by means of
1945 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1946 * packets that needed to be lumped together.
1948 static void ssh2_pkt_queuesend(Ssh ssh)
1952 assert(!ssh->queueing);
1954 for (i = 0; i < ssh->queuelen; i++)
1955 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
1958 ssh_pkt_defersend(ssh);
1962 void bndebug(char *string, Bignum b)
1966 p = ssh2_mpint_fmt(b, &len);
1967 debug(("%s", string));
1968 for (i = 0; i < len; i++)
1969 debug((" %02x", p[i]));
1975 static void sha_mpint(SHA_State * s, Bignum b)
1979 p = ssh2_mpint_fmt(b, &len);
1980 sha_string(s, p, len);
1985 * Packet decode functions for both SSH-1 and SSH-2.
1987 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1989 unsigned long value;
1990 if (pkt->length - pkt->savedpos < 4)
1991 return 0; /* arrgh, no way to decline (FIXME?) */
1992 value = GET_32BIT(pkt->body + pkt->savedpos);
1996 static int ssh2_pkt_getbool(struct Packet *pkt)
1998 unsigned long value;
1999 if (pkt->length - pkt->savedpos < 1)
2000 return 0; /* arrgh, no way to decline (FIXME?) */
2001 value = pkt->body[pkt->savedpos] != 0;
2005 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2010 if (pkt->length - pkt->savedpos < 4)
2012 len = GET_32BIT(pkt->body + pkt->savedpos);
2017 if (pkt->length - pkt->savedpos < *length)
2019 *p = (char *)(pkt->body + pkt->savedpos);
2020 pkt->savedpos += *length;
2022 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2024 if (pkt->length - pkt->savedpos < length)
2026 pkt->savedpos += length;
2027 return pkt->body + (pkt->savedpos - length);
2029 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2030 unsigned char **keystr)
2034 j = makekey(pkt->body + pkt->savedpos,
2035 pkt->length - pkt->savedpos,
2042 assert(pkt->savedpos < pkt->length);
2046 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2051 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2052 pkt->length - pkt->savedpos, &b);
2060 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2066 ssh_pkt_getstring(pkt, &p, &length);
2071 b = bignum_from_bytes((unsigned char *)p, length);
2076 * Helper function to add an SSH-2 signature blob to a packet.
2077 * Expects to be shown the public key blob as well as the signature
2078 * blob. Normally works just like ssh2_pkt_addstring, but will
2079 * fiddle with the signature packet if necessary for
2080 * BUG_SSH2_RSA_PADDING.
2082 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2083 void *pkblob_v, int pkblob_len,
2084 void *sigblob_v, int sigblob_len)
2086 unsigned char *pkblob = (unsigned char *)pkblob_v;
2087 unsigned char *sigblob = (unsigned char *)sigblob_v;
2089 /* dmemdump(pkblob, pkblob_len); */
2090 /* dmemdump(sigblob, sigblob_len); */
2093 * See if this is in fact an ssh-rsa signature and a buggy
2094 * server; otherwise we can just do this the easy way.
2096 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2097 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2098 int pos, len, siglen;
2101 * Find the byte length of the modulus.
2104 pos = 4+7; /* skip over "ssh-rsa" */
2105 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2106 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2107 pos += 4; /* find modulus itself */
2108 while (len > 0 && pkblob[pos] == 0)
2110 /* debug(("modulus length is %d\n", len)); */
2113 * Now find the signature integer.
2115 pos = 4+7; /* skip over "ssh-rsa" */
2116 siglen = GET_32BIT(sigblob+pos);
2117 /* debug(("signature length is %d\n", siglen)); */
2119 if (len != siglen) {
2120 unsigned char newlen[4];
2121 ssh2_pkt_addstring_start(pkt);
2122 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2123 /* dmemdump(sigblob, pos); */
2124 pos += 4; /* point to start of actual sig */
2125 PUT_32BIT(newlen, len);
2126 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2127 /* dmemdump(newlen, 4); */
2129 while (len-- > siglen) {
2130 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2131 /* dmemdump(newlen, 1); */
2133 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2134 /* dmemdump(sigblob+pos, siglen); */
2138 /* Otherwise fall through and do it the easy way. */
2141 ssh2_pkt_addstring_start(pkt);
2142 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2146 * Examine the remote side's version string and compare it against
2147 * a list of known buggy implementations.
2149 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2151 char *imp; /* pointer to implementation part */
2153 imp += strcspn(imp, "-");
2155 imp += strcspn(imp, "-");
2158 ssh->remote_bugs = 0;
2160 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2161 (ssh->cfg.sshbug_ignore1 == AUTO &&
2162 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2163 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2164 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2165 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2167 * These versions don't support SSH1_MSG_IGNORE, so we have
2168 * to use a different defence against password length
2171 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2172 logevent("We believe remote version has SSH-1 ignore bug");
2175 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2176 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2177 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2179 * These versions need a plain password sent; they can't
2180 * handle having a null and a random length of data after
2183 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2184 logevent("We believe remote version needs a plain SSH-1 password");
2187 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2188 (ssh->cfg.sshbug_rsa1 == AUTO &&
2189 (!strcmp(imp, "Cisco-1.25")))) {
2191 * These versions apparently have no clue whatever about
2192 * RSA authentication and will panic and die if they see
2193 * an AUTH_RSA message.
2195 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2196 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2199 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2200 (ssh->cfg.sshbug_hmac2 == AUTO &&
2201 !wc_match("* VShell", imp) &&
2202 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2203 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2204 wc_match("2.1 *", imp)))) {
2206 * These versions have the HMAC bug.
2208 ssh->remote_bugs |= BUG_SSH2_HMAC;
2209 logevent("We believe remote version has SSH-2 HMAC bug");
2212 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2213 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2214 !wc_match("* VShell", imp) &&
2215 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2217 * These versions have the key-derivation bug (failing to
2218 * include the literal shared secret in the hashes that
2219 * generate the keys).
2221 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2222 logevent("We believe remote version has SSH-2 key-derivation bug");
2225 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2226 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2227 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2228 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2230 * These versions have the SSH-2 RSA padding bug.
2232 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2233 logevent("We believe remote version has SSH-2 RSA padding bug");
2236 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2237 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2238 wc_match("OpenSSH_2.[0-2]*", imp))) {
2240 * These versions have the SSH-2 session-ID bug in
2241 * public-key authentication.
2243 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2244 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2247 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2248 (ssh->cfg.sshbug_rekey2 == AUTO &&
2249 (wc_match("DigiSSH_2.0", imp) ||
2250 wc_match("OpenSSH_2.[0-4]*", imp) ||
2251 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2252 wc_match("Sun_SSH_1.0", imp) ||
2253 wc_match("Sun_SSH_1.0.1", imp) ||
2254 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2255 wc_match("WeOnlyDo-*", imp)))) {
2257 * These versions have the SSH-2 rekey bug.
2259 ssh->remote_bugs |= BUG_SSH2_REKEY;
2260 logevent("We believe remote version has SSH-2 rekey bug");
2265 * The `software version' part of an SSH version string is required
2266 * to contain no spaces or minus signs.
2268 static void ssh_fix_verstring(char *str)
2270 /* Eat "SSH-<protoversion>-". */
2271 assert(*str == 'S'); str++;
2272 assert(*str == 'S'); str++;
2273 assert(*str == 'H'); str++;
2274 assert(*str == '-'); str++;
2275 while (*str && *str != '-') str++;
2276 assert(*str == '-'); str++;
2278 /* Convert minus signs and spaces in the remaining string into
2281 if (*str == '-' || *str == ' ')
2287 static int do_ssh_init(Ssh ssh, unsigned char c)
2289 struct do_ssh_init_state {
2297 crState(do_ssh_init_state);
2299 crBegin(ssh->do_ssh_init_crstate);
2301 /* Search for a line beginning with the string "SSH-" in the input. */
2303 if (c != 'S') goto no;
2305 if (c != 'S') goto no;
2307 if (c != 'H') goto no;
2309 if (c != '-') goto no;
2318 s->vstring = snewn(s->vstrsize, char);
2319 strcpy(s->vstring, "SSH-");
2323 crReturn(1); /* get another char */
2324 if (s->vslen >= s->vstrsize - 1) {
2326 s->vstring = sresize(s->vstring, s->vstrsize, char);
2328 s->vstring[s->vslen++] = c;
2331 s->version[s->i] = '\0';
2333 } else if (s->i < sizeof(s->version) - 1)
2334 s->version[s->i++] = c;
2335 } else if (c == '\012')
2339 ssh->agentfwd_enabled = FALSE;
2340 ssh->rdpkt2_state.incoming_sequence = 0;
2342 s->vstring[s->vslen] = 0;
2343 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2344 logeventf(ssh, "Server version: %s", s->vstring);
2345 ssh_detect_bugs(ssh, s->vstring);
2348 * Decide which SSH protocol version to support.
2351 /* Anything strictly below "2.0" means protocol 1 is supported. */
2352 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2353 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2354 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2356 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2357 bombout(("SSH protocol version 1 required by user but not provided by server"));
2360 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2361 bombout(("SSH protocol version 2 required by user but not provided by server"));
2368 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2370 * Construct a v2 version string.
2372 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2376 * Construct a v1 version string.
2378 verstring = dupprintf("SSH-%s-%s\012",
2379 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2380 s->version : "1.5"),
2385 ssh_fix_verstring(verstring);
2387 if (ssh->version == 2) {
2390 * Hash our version string and their version string.
2392 len = strcspn(verstring, "\015\012");
2393 ssh->v_c = snewn(len + 1, char);
2394 memcpy(ssh->v_c, verstring, len);
2396 len = strcspn(s->vstring, "\015\012");
2397 ssh->v_s = snewn(len + 1, char);
2398 memcpy(ssh->v_s, s->vstring, len);
2402 * Initialise SSH-2 protocol.
2404 ssh->protocol = ssh2_protocol;
2405 ssh2_protocol_setup(ssh);
2406 ssh->s_rdpkt = ssh2_rdpkt;
2409 * Initialise SSH-1 protocol.
2411 ssh->protocol = ssh1_protocol;
2412 ssh1_protocol_setup(ssh);
2413 ssh->s_rdpkt = ssh1_rdpkt;
2415 logeventf(ssh, "We claim version: %.*s",
2416 strcspn(verstring, "\015\012"), verstring);
2417 sk_write(ssh->s, verstring, strlen(verstring));
2419 if (ssh->version == 2)
2420 do_ssh2_transport(ssh, NULL, -1, NULL);
2423 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2425 update_specials_menu(ssh->frontend);
2426 ssh->state = SSH_STATE_BEFORE_SIZE;
2427 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2434 static void ssh_process_incoming_data(Ssh ssh,
2435 unsigned char **data, int *datalen)
2437 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2439 ssh->protocol(ssh, NULL, 0, pktin);
2440 ssh_free_packet(pktin);
2444 static void ssh_queue_incoming_data(Ssh ssh,
2445 unsigned char **data, int *datalen)
2447 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2452 static void ssh_process_queued_incoming_data(Ssh ssh)
2455 unsigned char *data;
2458 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2459 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2463 while (!ssh->frozen && len > 0)
2464 ssh_process_incoming_data(ssh, &data, &len);
2467 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2471 static void ssh_set_frozen(Ssh ssh, int frozen)
2474 sk_set_frozen(ssh->s, frozen);
2475 ssh->frozen = frozen;
2478 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2480 crBegin(ssh->ssh_gotdata_crstate);
2483 * To begin with, feed the characters one by one to the
2484 * protocol initialisation / selection function do_ssh_init().
2485 * When that returns 0, we're done with the initial greeting
2486 * exchange and can move on to packet discipline.
2489 int ret; /* need not be kept across crReturn */
2491 crReturnV; /* more data please */
2492 ret = do_ssh_init(ssh, *data);
2500 * We emerge from that loop when the initial negotiation is
2501 * over and we have selected an s_rdpkt function. Now pass
2502 * everything to s_rdpkt, and then pass the resulting packets
2503 * to the proper protocol handler.
2507 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2509 ssh_queue_incoming_data(ssh, &data, &datalen);
2510 /* This uses up all data and cannot cause anything interesting
2511 * to happen; indeed, for anything to happen at all, we must
2512 * return, so break out. */
2514 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2515 /* This uses up some or all data, and may freeze the
2517 ssh_process_queued_incoming_data(ssh);
2519 /* This uses up some or all data, and may freeze the
2521 ssh_process_incoming_data(ssh, &data, &datalen);
2523 /* FIXME this is probably EBW. */
2524 if (ssh->state == SSH_STATE_CLOSED)
2527 /* We're out of data. Go and get some more. */
2533 static int ssh_do_close(Ssh ssh, int notify_exit)
2536 struct ssh_channel *c;
2538 ssh->state = SSH_STATE_CLOSED;
2539 expire_timer_context(ssh);
2544 notify_remote_exit(ssh->frontend);
2549 * Now we must shut down any port- and X-forwarded channels going
2550 * through this connection.
2552 if (ssh->channels) {
2553 while (NULL != (c = index234(ssh->channels, 0))) {
2556 x11_close(c->u.x11.s);
2559 pfd_close(c->u.pfd.s);
2562 del234(ssh->channels, c); /* moving next one to index 0 */
2563 if (ssh->version == 2)
2564 bufchain_clear(&c->v.v2.outbuffer);
2569 * Go through port-forwardings, and close any associated
2570 * listening sockets.
2572 if (ssh->portfwds) {
2573 struct ssh_portfwd *pf;
2574 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2575 /* Dispose of any listening socket. */
2577 pfd_terminate(pf->local);
2578 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2586 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2587 const char *error_msg, int error_code)
2589 Ssh ssh = (Ssh) plug;
2590 char addrbuf[256], *msg;
2592 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2595 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2597 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2603 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2606 Ssh ssh = (Ssh) plug;
2607 int need_notify = ssh_do_close(ssh, FALSE);
2610 if (!ssh->close_expected)
2611 error_msg = "Server unexpectedly closed network connection";
2613 error_msg = "Server closed network connection";
2617 notify_remote_exit(ssh->frontend);
2620 logevent(error_msg);
2621 if (!ssh->close_expected || !ssh->clean_exit)
2622 connection_fatal(ssh->frontend, "%s", error_msg);
2626 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2628 Ssh ssh = (Ssh) plug;
2629 ssh_gotdata(ssh, (unsigned char *)data, len);
2630 if (ssh->state == SSH_STATE_CLOSED) {
2631 ssh_do_close(ssh, TRUE);
2637 static void ssh_sent(Plug plug, int bufsize)
2639 Ssh ssh = (Ssh) plug;
2641 * If the send backlog on the SSH socket itself clears, we
2642 * should unthrottle the whole world if it was throttled.
2644 if (bufsize < SSH_MAX_BACKLOG)
2645 ssh_throttle_all(ssh, 0, bufsize);
2649 * Connect to specified host and port.
2650 * Returns an error message, or NULL on success.
2651 * Also places the canonical host name into `realhost'. It must be
2652 * freed by the caller.
2654 static const char *connect_to_host(Ssh ssh, char *host, int port,
2655 char **realhost, int nodelay, int keepalive)
2657 static const struct plug_function_table fn_table = {
2668 ssh->savedhost = snewn(1 + strlen(host), char);
2669 strcpy(ssh->savedhost, host);
2672 port = 22; /* default ssh port */
2673 ssh->savedport = port;
2678 logeventf(ssh, "Looking up host \"%s\"%s", host,
2679 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2680 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2681 addr = name_lookup(host, port, realhost, &ssh->cfg,
2682 ssh->cfg.addressfamily);
2683 if ((err = sk_addr_error(addr)) != NULL) {
2691 ssh->fn = &fn_table;
2692 ssh->s = new_connection(addr, *realhost, port,
2693 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2694 if ((err = sk_socket_error(ssh->s)) != NULL) {
2696 notify_remote_exit(ssh->frontend);
2704 * Throttle or unthrottle the SSH connection.
2706 static void ssh1_throttle(Ssh ssh, int adjust)
2708 int old_count = ssh->v1_throttle_count;
2709 ssh->v1_throttle_count += adjust;
2710 assert(ssh->v1_throttle_count >= 0);
2711 if (ssh->v1_throttle_count && !old_count) {
2712 ssh_set_frozen(ssh, 1);
2713 } else if (!ssh->v1_throttle_count && old_count) {
2714 ssh_set_frozen(ssh, 0);
2719 * Throttle or unthrottle _all_ local data streams (for when sends
2720 * on the SSH connection itself back up).
2722 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2725 struct ssh_channel *c;
2727 if (enable == ssh->throttled_all)
2729 ssh->throttled_all = enable;
2730 ssh->overall_bufsize = bufsize;
2733 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2735 case CHAN_MAINSESSION:
2737 * This is treated separately, outside the switch.
2741 x11_override_throttle(c->u.x11.s, enable);
2744 /* Agent channels require no buffer management. */
2747 pfd_override_throttle(c->u.pfd.s, enable);
2754 * Username and password input, abstracted off into routines
2755 * reusable in several places - even between SSH-1 and SSH-2.
2758 /* Set up a username or password input loop on a given buffer. */
2759 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2761 ssh->userpass_input_buffer = buffer;
2762 ssh->userpass_input_buflen = buflen;
2763 ssh->userpass_input_bufpos = 0;
2764 ssh->userpass_input_echo = echo;
2768 * Process some terminal data in the course of username/password
2769 * input. Returns >0 for success (line of input returned in
2770 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2771 * for inconclusive (keep waiting for more input please).
2773 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2778 switch (c = *in++) {
2781 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2782 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2787 if (ssh->userpass_input_bufpos > 0) {
2788 if (ssh->userpass_input_echo)
2789 c_write_str(ssh, "\b \b");
2790 ssh->userpass_input_bufpos--;
2795 while (ssh->userpass_input_bufpos > 0) {
2796 if (ssh->userpass_input_echo)
2797 c_write_str(ssh, "\b \b");
2798 ssh->userpass_input_bufpos--;
2807 * This simplistic check for printability is disabled
2808 * when we're doing password input, because some people
2809 * have control characters in their passwords.o
2811 if ((!ssh->userpass_input_echo ||
2812 (c >= ' ' && c <= '~') ||
2813 ((unsigned char) c >= 160))
2814 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2815 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2816 if (ssh->userpass_input_echo)
2817 c_write(ssh, &c, 1);
2825 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2827 Ssh ssh = (Ssh) sshv;
2829 ssh->agent_response = reply;
2830 ssh->agent_response_len = replylen;
2832 if (ssh->version == 1)
2833 do_ssh1_login(ssh, NULL, -1, NULL);
2835 do_ssh2_authconn(ssh, NULL, -1, NULL);
2838 static void ssh_dialog_callback(void *sshv, int ret)
2840 Ssh ssh = (Ssh) sshv;
2842 ssh->user_response = ret;
2844 if (ssh->version == 1)
2845 do_ssh1_login(ssh, NULL, -1, NULL);
2847 do_ssh2_transport(ssh, NULL, -1, NULL);
2850 * This may have unfrozen the SSH connection, so do a
2853 ssh_process_queued_incoming_data(ssh);
2856 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2858 struct ssh_channel *c = (struct ssh_channel *)cv;
2860 void *sentreply = reply;
2863 /* Fake SSH_AGENT_FAILURE. */
2864 sentreply = "\0\0\0\1\5";
2867 if (ssh->version == 2) {
2868 ssh2_add_channel_data(c, sentreply, replylen);
2871 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2872 PKT_INT, c->remoteid,
2875 PKT_DATA, sentreply, replylen,
2884 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2885 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2886 * => log `wire_reason'.
2888 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2889 int code, int clean_exit)
2893 client_reason = wire_reason;
2895 error = dupprintf("Disconnected: %s", client_reason);
2897 error = dupstr("Disconnected");
2899 if (ssh->version == 1) {
2900 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2902 } else if (ssh->version == 2) {
2903 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2904 ssh2_pkt_adduint32(pktout, code);
2905 ssh2_pkt_addstring(pktout, wire_reason);
2906 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2907 ssh2_pkt_send_noqueue(ssh, pktout);
2910 ssh->close_expected = TRUE;
2911 ssh->clean_exit = clean_exit;
2912 ssh_closing((Plug)ssh, error, 0, 0);
2917 * Handle the key exchange and user authentication phases.
2919 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2920 struct Packet *pktin)
2923 unsigned char cookie[8], *ptr;
2924 struct RSAKey servkey, hostkey;
2925 struct MD5Context md5c;
2926 struct do_ssh1_login_state {
2928 unsigned char *rsabuf, *keystr1, *keystr2;
2929 unsigned long supported_ciphers_mask, supported_auths_mask;
2930 int tried_publickey, tried_agent;
2931 int tis_auth_refused, ccard_auth_refused;
2932 unsigned char session_id[16];
2935 void *publickey_blob;
2936 int publickey_bloblen;
2942 unsigned char request[5], *response, *p;
2952 crState(do_ssh1_login_state);
2954 crBegin(ssh->do_ssh1_login_crstate);
2959 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2960 bombout(("Public key packet not received"));
2964 logevent("Received public keys");
2966 ptr = ssh_pkt_getdata(pktin, 8);
2968 bombout(("SSH-1 public key packet stopped before random cookie"));
2971 memcpy(cookie, ptr, 8);
2973 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2974 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2975 bombout(("Failed to read SSH-1 public keys from public key packet"));
2980 * Log the host key fingerprint.
2984 logevent("Host key fingerprint is:");
2985 strcpy(logmsg, " ");
2986 hostkey.comment = NULL;
2987 rsa_fingerprint(logmsg + strlen(logmsg),
2988 sizeof(logmsg) - strlen(logmsg), &hostkey);
2992 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2993 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2994 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2996 ssh->v1_local_protoflags =
2997 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2998 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
3001 MD5Update(&md5c, s->keystr2, hostkey.bytes);
3002 MD5Update(&md5c, s->keystr1, servkey.bytes);
3003 MD5Update(&md5c, cookie, 8);
3004 MD5Final(s->session_id, &md5c);
3006 for (i = 0; i < 32; i++)
3007 ssh->session_key[i] = random_byte();
3010 * Verify that the `bits' and `bytes' parameters match.
3012 if (hostkey.bits > hostkey.bytes * 8 ||
3013 servkey.bits > servkey.bytes * 8) {
3014 bombout(("SSH-1 public keys were badly formatted"));
3018 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3020 s->rsabuf = snewn(s->len, unsigned char);
3023 * Verify the host key.
3027 * First format the key into a string.
3029 int len = rsastr_len(&hostkey);
3030 char fingerprint[100];
3031 char *keystr = snewn(len, char);
3032 rsastr_fmt(keystr, &hostkey);
3033 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3035 ssh_set_frozen(ssh, 1);
3036 s->dlgret = verify_ssh_host_key(ssh->frontend,
3037 ssh->savedhost, ssh->savedport,
3038 "rsa", keystr, fingerprint,
3039 ssh_dialog_callback, ssh);
3041 if (s->dlgret < 0) {
3045 bombout(("Unexpected data from server while waiting"
3046 " for user host key response"));
3049 } while (pktin || inlen > 0);
3050 s->dlgret = ssh->user_response;
3052 ssh_set_frozen(ssh, 0);
3054 if (s->dlgret == 0) {
3055 ssh_disconnect(ssh, "User aborted at host key verification",
3061 for (i = 0; i < 32; i++) {
3062 s->rsabuf[i] = ssh->session_key[i];
3064 s->rsabuf[i] ^= s->session_id[i];
3067 if (hostkey.bytes > servkey.bytes) {
3068 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3070 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3072 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3074 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3077 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3081 logevent("Encrypted session key");
3084 int cipher_chosen = 0, warn = 0;
3085 char *cipher_string = NULL;
3087 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3088 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3089 if (next_cipher == CIPHER_WARN) {
3090 /* If/when we choose a cipher, warn about it */
3092 } else if (next_cipher == CIPHER_AES) {
3093 /* XXX Probably don't need to mention this. */
3094 logevent("AES not supported in SSH-1, skipping");
3096 switch (next_cipher) {
3097 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3098 cipher_string = "3DES"; break;
3099 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3100 cipher_string = "Blowfish"; break;
3101 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3102 cipher_string = "single-DES"; break;
3104 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3108 if (!cipher_chosen) {
3109 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3110 bombout(("Server violates SSH-1 protocol by not "
3111 "supporting 3DES encryption"));
3113 /* shouldn't happen */
3114 bombout(("No supported ciphers found"));
3118 /* Warn about chosen cipher if necessary. */
3120 ssh_set_frozen(ssh, 1);
3121 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3122 ssh_dialog_callback, ssh);
3123 if (s->dlgret < 0) {
3127 bombout(("Unexpected data from server while waiting"
3128 " for user response"));
3131 } while (pktin || inlen > 0);
3132 s->dlgret = ssh->user_response;
3134 ssh_set_frozen(ssh, 0);
3135 if (s->dlgret == 0) {
3136 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3143 switch (s->cipher_type) {
3144 case SSH_CIPHER_3DES:
3145 logevent("Using 3DES encryption");
3147 case SSH_CIPHER_DES:
3148 logevent("Using single-DES encryption");
3150 case SSH_CIPHER_BLOWFISH:
3151 logevent("Using Blowfish encryption");
3155 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3156 PKT_CHAR, s->cipher_type,
3157 PKT_DATA, cookie, 8,
3158 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3159 PKT_DATA, s->rsabuf, s->len,
3160 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3162 logevent("Trying to enable encryption...");
3166 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3167 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3169 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3170 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3171 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3173 ssh->crcda_ctx = crcda_make_context();
3174 logevent("Installing CRC compensation attack detector");
3176 if (servkey.modulus) {
3177 sfree(servkey.modulus);
3178 servkey.modulus = NULL;
3180 if (servkey.exponent) {
3181 sfree(servkey.exponent);
3182 servkey.exponent = NULL;
3184 if (hostkey.modulus) {
3185 sfree(hostkey.modulus);
3186 hostkey.modulus = NULL;
3188 if (hostkey.exponent) {
3189 sfree(hostkey.exponent);
3190 hostkey.exponent = NULL;
3194 if (pktin->type != SSH1_SMSG_SUCCESS) {
3195 bombout(("Encryption not successfully enabled"));
3199 logevent("Successfully started encryption");
3203 if (!*ssh->cfg.username) {
3204 if (ssh_get_line && !ssh_getline_pw_only) {
3205 if (!ssh_get_line("login as: ",
3206 s->username, sizeof(s->username), FALSE)) {
3208 * get_line failed to get a username.
3211 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3215 int ret; /* need not be kept over crReturn */
3216 c_write_str(ssh, "login as: ");
3219 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3221 crWaitUntil(!pktin);
3222 ret = process_userpass_input(ssh, in, inlen);
3226 c_write_str(ssh, "\r\n");
3229 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3230 s->username[sizeof(s->username)-1] = '\0';
3233 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3235 char userlog[22 + sizeof(s->username)];
3236 sprintf(userlog, "Sent username \"%s\"", s->username);
3238 if (flags & FLAG_INTERACTIVE &&
3239 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3240 strcat(userlog, "\r\n");
3241 c_write_str(ssh, userlog);
3248 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3249 /* We must not attempt PK auth. Pretend we've already tried it. */
3250 s->tried_publickey = s->tried_agent = 1;
3252 s->tried_publickey = s->tried_agent = 0;
3254 s->tis_auth_refused = s->ccard_auth_refused = 0;
3255 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3256 if (!filename_is_null(ssh->cfg.keyfile)) {
3257 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3258 &s->publickey_blob, &s->publickey_bloblen, NULL))
3259 s->publickey_blob = NULL;
3261 s->publickey_blob = NULL;
3263 while (pktin->type == SSH1_SMSG_FAILURE) {
3264 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3266 if (agent_exists() && !s->tried_agent) {
3268 * Attempt RSA authentication using Pageant.
3274 logevent("Pageant is running. Requesting keys.");
3276 /* Request the keys held by the agent. */
3277 PUT_32BIT(s->request, 1);
3278 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3279 if (!agent_query(s->request, 5, &r, &s->responselen,
3280 ssh_agent_callback, ssh)) {
3284 bombout(("Unexpected data from server while waiting"
3285 " for agent response"));
3288 } while (pktin || inlen > 0);
3289 r = ssh->agent_response;
3290 s->responselen = ssh->agent_response_len;
3292 s->response = (unsigned char *) r;
3293 if (s->response && s->responselen >= 5 &&
3294 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3295 s->p = s->response + 5;
3296 s->nkeys = GET_32BIT(s->p);
3298 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3299 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3300 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3301 if (s->publickey_blob &&
3302 !memcmp(s->p, s->publickey_blob,
3303 s->publickey_bloblen)) {
3304 logevent("This key matches configured key file");
3305 s->tried_publickey = 1;
3310 do { /* do while (0) to make breaking easy */
3311 n = ssh1_read_bignum
3312 (s->p, s->responselen-(s->p-s->response),
3317 n = ssh1_read_bignum
3318 (s->p, s->responselen-(s->p-s->response),
3323 if (s->responselen - (s->p-s->response) < 4)
3325 s->commentlen = GET_32BIT(s->p);
3327 if (s->responselen - (s->p-s->response) <
3330 s->commentp = (char *)s->p;
3331 s->p += s->commentlen;
3335 logevent("Pageant key list packet was truncated");
3339 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3340 PKT_BIGNUM, s->key.modulus, PKT_END);
3342 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3343 logevent("Key refused");
3346 logevent("Received RSA challenge");
3347 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3348 bombout(("Server's RSA challenge was badly formatted"));
3353 char *agentreq, *q, *ret;
3356 len = 1 + 4; /* message type, bit count */
3357 len += ssh1_bignum_length(s->key.exponent);
3358 len += ssh1_bignum_length(s->key.modulus);
3359 len += ssh1_bignum_length(s->challenge);
3360 len += 16; /* session id */
3361 len += 4; /* response format */
3362 agentreq = snewn(4 + len, char);
3363 PUT_32BIT(agentreq, len);
3365 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3366 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3368 q += ssh1_write_bignum(q, s->key.exponent);
3369 q += ssh1_write_bignum(q, s->key.modulus);
3370 q += ssh1_write_bignum(q, s->challenge);
3371 memcpy(q, s->session_id, 16);
3373 PUT_32BIT(q, 1); /* response format */
3374 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3375 ssh_agent_callback, ssh)) {
3380 bombout(("Unexpected data from server"
3381 " while waiting for agent"
3385 } while (pktin || inlen > 0);
3386 vret = ssh->agent_response;
3387 retlen = ssh->agent_response_len;
3392 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3393 logevent("Sending Pageant's response");
3394 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3395 PKT_DATA, ret + 5, 16,
3399 if (pktin->type == SSH1_SMSG_SUCCESS) {
3401 ("Pageant's response accepted");
3402 if (flags & FLAG_VERBOSE) {
3403 c_write_str(ssh, "Authenticated using"
3405 c_write(ssh, s->commentp,
3407 c_write_str(ssh, "\" from agent\r\n");
3412 ("Pageant's response not accepted");
3415 ("Pageant failed to answer challenge");
3419 logevent("No reply received from Pageant");
3422 freebn(s->key.exponent);
3423 freebn(s->key.modulus);
3424 freebn(s->challenge);
3433 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3434 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3436 if (ssh->cfg.try_tis_auth &&
3437 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3438 !s->tis_auth_refused) {
3439 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3440 logevent("Requested TIS authentication");
3441 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3443 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3444 logevent("TIS authentication declined");
3445 if (flags & FLAG_INTERACTIVE)
3446 c_write_str(ssh, "TIS authentication refused.\r\n");
3447 s->tis_auth_refused = 1;
3453 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3455 bombout(("TIS challenge packet was badly formed"));
3458 c_write_str(ssh, "Using TIS authentication.\r\n");
3459 logevent("Received TIS challenge");
3460 if (challengelen > sizeof(s->prompt) - 1)
3461 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3462 memcpy(s->prompt, challenge, challengelen);
3463 /* Prompt heuristic comes from OpenSSH */
3464 strncpy(s->prompt + challengelen,
3465 memchr(s->prompt, '\n', challengelen) ?
3466 "": "\r\nResponse: ",
3467 (sizeof s->prompt) - challengelen);
3468 s->prompt[(sizeof s->prompt) - 1] = '\0';
3471 if (ssh->cfg.try_tis_auth &&
3472 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3473 !s->ccard_auth_refused) {
3474 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3475 logevent("Requested CryptoCard authentication");
3476 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3478 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3479 logevent("CryptoCard authentication declined");
3480 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3481 s->ccard_auth_refused = 1;
3487 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3489 bombout(("CryptoCard challenge packet was badly formed"));
3492 c_write_str(ssh, "Using CryptoCard authentication.\r\n");
3493 logevent("Received CryptoCard challenge");
3494 if (challengelen > sizeof(s->prompt) - 1)
3495 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3496 memcpy(s->prompt, challenge, challengelen);
3497 strncpy(s->prompt + challengelen,
3498 memchr(s->prompt, '\n', challengelen) ?
3499 "" : "\r\nResponse: ",
3500 sizeof(s->prompt) - challengelen);
3501 s->prompt[sizeof(s->prompt) - 1] = '\0';
3504 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3505 sprintf(s->prompt, "%.90s@%.90s's password: ",
3506 s->username, ssh->savedhost);
3508 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3509 char *comment = NULL;
3511 if (flags & FLAG_VERBOSE)
3512 c_write_str(ssh, "Trying public key authentication.\r\n");
3513 logeventf(ssh, "Trying public key \"%s\"",
3514 filename_to_str(&ssh->cfg.keyfile));
3515 type = key_type(&ssh->cfg.keyfile);
3516 if (type != SSH_KEYTYPE_SSH1) {
3517 char *msg = dupprintf("Key is of wrong type (%s)",
3518 key_type_to_str(type));
3520 c_write_str(ssh, msg);
3521 c_write_str(ssh, "\r\n");
3523 s->tried_publickey = 1;
3526 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3527 if (flags & FLAG_VERBOSE)
3528 c_write_str(ssh, "No passphrase required.\r\n");
3531 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3536 * Show password prompt, having first obtained it via a TIS
3537 * or CryptoCard exchange if we're doing TIS or CryptoCard
3541 if (!ssh_get_line(s->prompt, s->password,
3542 sizeof(s->password), TRUE)) {
3544 * get_line failed to get a password (for example
3545 * because one was supplied on the command line
3546 * which has already failed to work). Terminate.
3548 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, FALSE);
3552 /* Prompt may have come from server. We've munged it a bit, so
3553 * we know it to be zero-terminated at least once. */
3554 int ret; /* need not be saved over crReturn */
3555 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3558 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3560 crWaitUntil(!pktin);
3561 ret = process_userpass_input(ssh, in, inlen);
3565 c_write_str(ssh, "\r\n");
3569 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3571 * Try public key authentication with the specified
3574 s->tried_publickey = 1;
3577 const char *error = NULL;
3578 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3581 c_write_str(ssh, "Couldn't load private key from ");
3582 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3583 c_write_str(ssh, " (");
3584 c_write_str(ssh, error);
3585 c_write_str(ssh, ").\r\n");
3586 continue; /* go and try password */
3589 c_write_str(ssh, "Wrong passphrase.\r\n");
3590 s->tried_publickey = 0;
3591 continue; /* try again */
3596 * Send a public key attempt.
3598 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3599 PKT_BIGNUM, s->key.modulus, PKT_END);
3602 if (pktin->type == SSH1_SMSG_FAILURE) {
3603 c_write_str(ssh, "Server refused our public key.\r\n");
3604 continue; /* go and try password */
3606 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3607 bombout(("Bizarre response to offer of public key"));
3613 unsigned char buffer[32];
3614 Bignum challenge, response;
3616 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3617 bombout(("Server's RSA challenge was badly formatted"));
3620 response = rsadecrypt(challenge, &s->key);
3621 freebn(s->key.private_exponent);/* burn the evidence */
3623 for (i = 0; i < 32; i++) {
3624 buffer[i] = bignum_byte(response, 31 - i);
3628 MD5Update(&md5c, buffer, 32);
3629 MD5Update(&md5c, s->session_id, 16);
3630 MD5Final(buffer, &md5c);
3632 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3633 PKT_DATA, buffer, 16, PKT_END);
3640 if (pktin->type == SSH1_SMSG_FAILURE) {
3641 if (flags & FLAG_VERBOSE)
3642 c_write_str(ssh, "Failed to authenticate with"
3643 " our public key.\r\n");
3644 continue; /* go and try password */
3645 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3646 bombout(("Bizarre response to RSA authentication response"));
3650 break; /* we're through! */
3652 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3654 * Defence against traffic analysis: we send a
3655 * whole bunch of packets containing strings of
3656 * different lengths. One of these strings is the
3657 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3658 * The others are all random data in
3659 * SSH1_MSG_IGNORE packets. This way a passive
3660 * listener can't tell which is the password, and
3661 * hence can't deduce the password length.
3663 * Anybody with a password length greater than 16
3664 * bytes is going to have enough entropy in their
3665 * password that a listener won't find it _that_
3666 * much help to know how long it is. So what we'll
3669 * - if password length < 16, we send 15 packets
3670 * containing string lengths 1 through 15
3672 * - otherwise, we let N be the nearest multiple
3673 * of 8 below the password length, and send 8
3674 * packets containing string lengths N through
3675 * N+7. This won't obscure the order of
3676 * magnitude of the password length, but it will
3677 * introduce a bit of extra uncertainty.
3679 * A few servers (the old 1.2.18 through 1.2.22)
3680 * can't deal with SSH1_MSG_IGNORE. For these
3681 * servers, we need an alternative defence. We make
3682 * use of the fact that the password is interpreted
3683 * as a C string: so we can append a NUL, then some
3686 * One server (a Cisco one) can deal with neither
3687 * SSH1_MSG_IGNORE _nor_ a padded password string.
3688 * For this server we are left with no defences
3689 * against password length sniffing.
3691 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3693 * The server can deal with SSH1_MSG_IGNORE, so
3694 * we can use the primary defence.
3696 int bottom, top, pwlen, i;
3699 pwlen = strlen(s->password);
3701 bottom = 0; /* zero length passwords are OK! :-) */
3704 bottom = pwlen & ~7;
3708 assert(pwlen >= bottom && pwlen <= top);
3710 randomstr = snewn(top + 1, char);
3712 for (i = bottom; i <= top; i++) {
3714 defer_packet(ssh, s->pwpkt_type,
3715 PKTT_PASSWORD, PKT_STR, s->password,
3716 PKTT_OTHER, PKT_END);
3718 for (j = 0; j < i; j++) {
3720 randomstr[j] = random_byte();
3721 } while (randomstr[j] == '\0');
3723 randomstr[i] = '\0';
3724 defer_packet(ssh, SSH1_MSG_IGNORE,
3725 PKT_STR, randomstr, PKT_END);
3728 logevent("Sending password with camouflage packets");
3729 ssh_pkt_defersend(ssh);
3732 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3734 * The server can't deal with SSH1_MSG_IGNORE
3735 * but can deal with padded passwords, so we
3736 * can use the secondary defence.
3742 len = strlen(s->password);
3743 if (len < sizeof(string)) {
3745 strcpy(string, s->password);
3746 len++; /* cover the zero byte */
3747 while (len < sizeof(string)) {
3748 string[len++] = (char) random_byte();
3753 logevent("Sending length-padded password");
3754 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3755 PKT_INT, len, PKT_DATA, ss, len,
3756 PKTT_OTHER, PKT_END);
3759 * The server has _both_
3760 * BUG_CHOKES_ON_SSH1_IGNORE and
3761 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3762 * therefore nothing we can do.
3765 len = strlen(s->password);
3766 logevent("Sending unpadded password");
3767 send_packet(ssh, s->pwpkt_type,
3768 PKTT_PASSWORD, PKT_INT, len,
3769 PKT_DATA, s->password, len,
3770 PKTT_OTHER, PKT_END);
3773 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3774 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3777 logevent("Sent password");
3778 memset(s->password, 0, strlen(s->password));
3780 if (pktin->type == SSH1_SMSG_FAILURE) {
3781 if (flags & FLAG_VERBOSE)
3782 c_write_str(ssh, "Access denied\r\n");
3783 logevent("Authentication refused");
3784 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3785 bombout(("Strange packet received, type %d", pktin->type));
3790 logevent("Authentication successful");
3795 void sshfwd_close(struct ssh_channel *c)
3799 if (ssh->state == SSH_STATE_CLOSED)
3802 if (c && !c->closes) {
3804 * If halfopen is true, we have sent
3805 * CHANNEL_OPEN for this channel, but it hasn't even been
3806 * acknowledged by the server. So we must set a close flag
3807 * on it now, and then when the server acks the channel
3808 * open, we can close it then.
3811 if (ssh->version == 1) {
3812 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3815 struct Packet *pktout;
3816 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3817 ssh2_pkt_adduint32(pktout, c->remoteid);
3818 ssh2_pkt_send(ssh, pktout);
3821 c->closes = 1; /* sent MSG_CLOSE */
3822 if (c->type == CHAN_X11) {
3824 logevent("Forwarded X11 connection terminated");
3825 } else if (c->type == CHAN_SOCKDATA ||
3826 c->type == CHAN_SOCKDATA_DORMANT) {
3828 logevent("Forwarded port closed");
3833 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3837 if (ssh->state == SSH_STATE_CLOSED)
3840 if (ssh->version == 1) {
3841 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3842 PKT_INT, c->remoteid,
3844 PKT_INT, len, PKT_DATA, buf, len,
3845 PKTT_OTHER, PKT_END);
3847 * In SSH-1 we can return 0 here - implying that forwarded
3848 * connections are never individually throttled - because
3849 * the only circumstance that can cause throttling will be
3850 * the whole SSH connection backing up, in which case
3851 * _everything_ will be throttled as a whole.
3855 ssh2_add_channel_data(c, buf, len);
3856 return ssh2_try_send(c);
3860 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3864 if (ssh->state == SSH_STATE_CLOSED)
3867 if (ssh->version == 1) {
3868 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3869 c->v.v1.throttling = 0;
3870 ssh1_throttle(ssh, -1);
3873 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3877 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3879 struct queued_handler *qh = ssh->qhead;
3883 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3886 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3887 ssh->packet_dispatch[qh->msg1] = NULL;
3890 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3891 ssh->packet_dispatch[qh->msg2] = NULL;
3895 ssh->qhead = qh->next;
3897 if (ssh->qhead->msg1 > 0) {
3898 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3899 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3901 if (ssh->qhead->msg2 > 0) {
3902 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3903 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3906 ssh->qhead = ssh->qtail = NULL;
3907 ssh->packet_dispatch[pktin->type] = NULL;
3910 qh->handler(ssh, pktin, qh->ctx);
3915 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3916 chandler_fn_t handler, void *ctx)
3918 struct queued_handler *qh;
3920 qh = snew(struct queued_handler);
3923 qh->handler = handler;
3927 if (ssh->qtail == NULL) {
3931 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3932 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3935 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3936 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3939 ssh->qtail->next = qh;
3944 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3946 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3948 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3949 SSH2_MSG_REQUEST_SUCCESS)) {
3950 logeventf(ssh, "Remote port forwarding from %s enabled",
3953 logeventf(ssh, "Remote port forwarding from %s refused",
3956 rpf = del234(ssh->rportfwds, pf);
3962 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3964 const char *portfwd_strptr = cfg->portfwd;
3965 struct ssh_portfwd *epf;
3968 if (!ssh->portfwds) {
3969 ssh->portfwds = newtree234(ssh_portcmp);
3972 * Go through the existing port forwardings and tag them
3973 * with status==DESTROY. Any that we want to keep will be
3974 * re-enabled (status==KEEP) as we go through the
3975 * configuration and find out which bits are the same as
3978 struct ssh_portfwd *epf;
3980 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3981 epf->status = DESTROY;
3984 while (*portfwd_strptr) {
3985 char address_family, type;
3986 int sport,dport,sserv,dserv;
3987 char sports[256], dports[256], saddr[256], host[256];
3990 address_family = 'A';
3992 if (*portfwd_strptr == 'A' ||
3993 *portfwd_strptr == '4' ||
3994 *portfwd_strptr == '6')
3995 address_family = *portfwd_strptr++;
3996 if (*portfwd_strptr == 'L' ||
3997 *portfwd_strptr == 'R' ||
3998 *portfwd_strptr == 'D')
3999 type = *portfwd_strptr++;
4004 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4005 if (*portfwd_strptr == ':') {
4007 * We've seen a colon in the middle of the
4008 * source port number. This means that
4009 * everything we've seen until now is the
4010 * source _address_, so we'll move it into
4011 * saddr and start sports from the beginning
4016 if (ssh->version == 1 && type == 'R') {
4017 logeventf(ssh, "SSH-1 cannot handle remote source address "
4018 "spec \"%s\"; ignoring", sports);
4020 strcpy(saddr, sports);
4023 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4027 if (*portfwd_strptr == '\t')
4030 while (*portfwd_strptr && *portfwd_strptr != ':') {
4031 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4034 if (*portfwd_strptr == ':')
4037 while (*portfwd_strptr) {
4038 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4042 dport = atoi(dports);
4046 dport = net_service_lookup(dports);
4048 logeventf(ssh, "Service lookup failed for destination"
4049 " port \"%s\"", dports);
4053 while (*portfwd_strptr) portfwd_strptr++;
4057 portfwd_strptr++; /* eat the NUL and move to next one */
4059 sport = atoi(sports);
4063 sport = net_service_lookup(sports);
4065 logeventf(ssh, "Service lookup failed for source"
4066 " port \"%s\"", sports);
4069 if (sport && dport) {
4070 /* Set up a description of the source port. */
4071 struct ssh_portfwd *pfrec, *epfrec;
4073 pfrec = snew(struct ssh_portfwd);
4075 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4076 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4077 pfrec->sport = sport;
4078 pfrec->daddr = *host ? dupstr(host) : NULL;
4079 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4080 pfrec->dport = dport;
4081 pfrec->local = NULL;
4082 pfrec->remote = NULL;
4083 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4084 address_family == '6' ? ADDRTYPE_IPV6 :
4087 epfrec = add234(ssh->portfwds, pfrec);
4088 if (epfrec != pfrec) {
4090 * We already have a port forwarding with precisely
4091 * these parameters. Hence, no need to do anything;
4092 * simply tag the existing one as KEEP.
4094 epfrec->status = KEEP;
4095 free_portfwd(pfrec);
4097 pfrec->status = CREATE;
4103 * Now go through and destroy any port forwardings which were
4106 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4107 if (epf->status == DESTROY) {
4110 message = dupprintf("%s port forwarding from %s%s%d",
4111 epf->type == 'L' ? "local" :
4112 epf->type == 'R' ? "remote" : "dynamic",
4113 epf->saddr ? epf->saddr : "",
4114 epf->saddr ? ":" : "",
4117 if (epf->type != 'D') {
4118 char *msg2 = dupprintf("%s to %s:%d", message,
4119 epf->daddr, epf->dport);
4124 logeventf(ssh, "Cancelling %s", message);
4128 struct ssh_rportfwd *rpf = epf->remote;
4129 struct Packet *pktout;
4132 * Cancel the port forwarding at the server
4135 if (ssh->version == 1) {
4137 * We cannot cancel listening ports on the
4138 * server side in SSH-1! There's no message
4139 * to support it. Instead, we simply remove
4140 * the rportfwd record from the local end
4141 * so that any connections the server tries
4142 * to make on it are rejected.
4145 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4146 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4147 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4149 ssh2_pkt_addstring(pktout, epf->saddr);
4150 } else if (ssh->cfg.rport_acceptall) {
4151 /* XXX: ssh->cfg.rport_acceptall may not represent
4152 * what was used to open the original connection,
4153 * since it's reconfigurable. */
4154 ssh2_pkt_addstring(pktout, "0.0.0.0");
4156 ssh2_pkt_addstring(pktout, "127.0.0.1");
4158 ssh2_pkt_adduint32(pktout, epf->sport);
4159 ssh2_pkt_send(ssh, pktout);
4162 del234(ssh->rportfwds, rpf);
4164 } else if (epf->local) {
4165 pfd_terminate(epf->local);
4168 delpos234(ssh->portfwds, i);
4170 i--; /* so we don't skip one in the list */
4174 * And finally, set up any new port forwardings (status==CREATE).
4176 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4177 if (epf->status == CREATE) {
4178 char *sportdesc, *dportdesc;
4179 sportdesc = dupprintf("%s%s%s%s%d%s",
4180 epf->saddr ? epf->saddr : "",
4181 epf->saddr ? ":" : "",
4182 epf->sserv ? epf->sserv : "",
4183 epf->sserv ? "(" : "",
4185 epf->sserv ? ")" : "");
4186 if (epf->type == 'D') {
4189 dportdesc = dupprintf("%s:%s%s%d%s",
4191 epf->dserv ? epf->dserv : "",
4192 epf->dserv ? "(" : "",
4194 epf->dserv ? ")" : "");
4197 if (epf->type == 'L') {
4198 const char *err = pfd_addforward(epf->daddr, epf->dport,
4199 epf->saddr, epf->sport,
4202 epf->addressfamily);
4204 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4205 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4206 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4207 sportdesc, dportdesc,
4208 err ? " failed: " : "", err ? err : "");
4209 } else if (epf->type == 'D') {
4210 const char *err = pfd_addforward(NULL, -1,
4211 epf->saddr, epf->sport,
4214 epf->addressfamily);
4216 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4217 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4218 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4220 err ? " failed: " : "", err ? err : "");
4222 struct ssh_rportfwd *pf;
4225 * Ensure the remote port forwardings tree exists.
4227 if (!ssh->rportfwds) {
4228 if (ssh->version == 1)
4229 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4231 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4234 pf = snew(struct ssh_rportfwd);
4235 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4236 pf->dhost[lenof(pf->dhost)-1] = '\0';
4237 pf->dport = epf->dport;
4238 pf->sport = epf->sport;
4239 if (add234(ssh->rportfwds, pf) != pf) {
4240 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4241 epf->daddr, epf->dport);
4244 logeventf(ssh, "Requesting remote port %s"
4245 " forward to %s", sportdesc, dportdesc);
4247 pf->sportdesc = sportdesc;
4252 if (ssh->version == 1) {
4253 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4254 PKT_INT, epf->sport,
4255 PKT_STR, epf->daddr,
4256 PKT_INT, epf->dport,
4258 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4260 ssh_rportfwd_succfail, pf);
4262 struct Packet *pktout;
4263 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4264 ssh2_pkt_addstring(pktout, "tcpip-forward");
4265 ssh2_pkt_addbool(pktout, 1);/* want reply */
4267 ssh2_pkt_addstring(pktout, epf->saddr);
4268 } else if (cfg->rport_acceptall) {
4269 ssh2_pkt_addstring(pktout, "0.0.0.0");
4271 ssh2_pkt_addstring(pktout, "127.0.0.1");
4273 ssh2_pkt_adduint32(pktout, epf->sport);
4274 ssh2_pkt_send(ssh, pktout);
4276 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4277 SSH2_MSG_REQUEST_FAILURE,
4278 ssh_rportfwd_succfail, pf);
4287 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4290 int stringlen, bufsize;
4292 ssh_pkt_getstring(pktin, &string, &stringlen);
4293 if (string == NULL) {
4294 bombout(("Incoming terminal data packet was badly formed"));
4298 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4300 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4301 ssh->v1_stdout_throttling = 1;
4302 ssh1_throttle(ssh, +1);
4306 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4308 /* Remote side is trying to open a channel to talk to our
4309 * X-Server. Give them back a local channel number. */
4310 struct ssh_channel *c;
4311 int remoteid = ssh_pkt_getuint32(pktin);
4313 logevent("Received X11 connect request");
4314 /* Refuse if X11 forwarding is disabled. */
4315 if (!ssh->X11_fwd_enabled) {
4316 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4317 PKT_INT, remoteid, PKT_END);
4318 logevent("Rejected X11 connect request");
4320 c = snew(struct ssh_channel);
4323 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4324 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4325 logevent("Opening X11 forward connection failed");
4327 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4328 PKT_INT, remoteid, PKT_END);
4331 ("Opening X11 forward connection succeeded");
4332 c->remoteid = remoteid;
4333 c->halfopen = FALSE;
4334 c->localid = alloc_channel_id(ssh);
4336 c->v.v1.throttling = 0;
4337 c->type = CHAN_X11; /* identify channel type */
4338 add234(ssh->channels, c);
4339 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4340 PKT_INT, c->remoteid, PKT_INT,
4341 c->localid, PKT_END);
4342 logevent("Opened X11 forward channel");
4347 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4349 /* Remote side is trying to open a channel to talk to our
4350 * agent. Give them back a local channel number. */
4351 struct ssh_channel *c;
4352 int remoteid = ssh_pkt_getuint32(pktin);
4354 /* Refuse if agent forwarding is disabled. */
4355 if (!ssh->agentfwd_enabled) {
4356 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4357 PKT_INT, remoteid, PKT_END);
4359 c = snew(struct ssh_channel);
4361 c->remoteid = remoteid;
4362 c->halfopen = FALSE;
4363 c->localid = alloc_channel_id(ssh);
4365 c->v.v1.throttling = 0;
4366 c->type = CHAN_AGENT; /* identify channel type */
4367 c->u.a.lensofar = 0;
4368 add234(ssh->channels, c);
4369 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4370 PKT_INT, c->remoteid, PKT_INT, c->localid,
4375 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4377 /* Remote side is trying to open a channel to talk to a
4378 * forwarded port. Give them back a local channel number. */
4379 struct ssh_channel *c;
4380 struct ssh_rportfwd pf, *pfp;
4385 c = snew(struct ssh_channel);
4388 remoteid = ssh_pkt_getuint32(pktin);
4389 ssh_pkt_getstring(pktin, &host, &hostsize);
4390 port = ssh_pkt_getuint32(pktin);
4392 if (hostsize >= lenof(pf.dhost))
4393 hostsize = lenof(pf.dhost)-1;
4394 memcpy(pf.dhost, host, hostsize);
4395 pf.dhost[hostsize] = '\0';
4397 pfp = find234(ssh->rportfwds, &pf, NULL);
4400 logeventf(ssh, "Rejected remote port open request for %s:%d",
4402 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4403 PKT_INT, remoteid, PKT_END);
4405 logeventf(ssh, "Received remote port open request for %s:%d",
4407 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4408 c, &ssh->cfg, pfp->pfrec->addressfamily);
4410 logeventf(ssh, "Port open failed: %s", e);
4412 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4413 PKT_INT, remoteid, PKT_END);
4415 c->remoteid = remoteid;
4416 c->halfopen = FALSE;
4417 c->localid = alloc_channel_id(ssh);
4419 c->v.v1.throttling = 0;
4420 c->type = CHAN_SOCKDATA; /* identify channel type */
4421 add234(ssh->channels, c);
4422 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4423 PKT_INT, c->remoteid, PKT_INT,
4424 c->localid, PKT_END);
4425 logevent("Forwarded port opened successfully");
4430 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4432 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4433 unsigned int localid = ssh_pkt_getuint32(pktin);
4434 struct ssh_channel *c;
4436 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4437 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4438 c->remoteid = localid;
4439 c->halfopen = FALSE;
4440 c->type = CHAN_SOCKDATA;
4441 c->v.v1.throttling = 0;
4442 pfd_confirm(c->u.pfd.s);
4445 if (c && c->closes) {
4447 * We have a pending close on this channel,
4448 * which we decided on before the server acked
4449 * the channel open. So now we know the
4450 * remoteid, we can close it again.
4452 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4453 PKT_INT, c->remoteid, PKT_END);
4457 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4459 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4460 struct ssh_channel *c;
4462 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4463 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4464 logevent("Forwarded connection refused by server");
4465 pfd_close(c->u.pfd.s);
4466 del234(ssh->channels, c);
4471 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4473 /* Remote side closes a channel. */
4474 unsigned i = ssh_pkt_getuint32(pktin);
4475 struct ssh_channel *c;
4476 c = find234(ssh->channels, &i, ssh_channelfind);
4477 if (c && !c->halfopen) {
4480 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4482 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4483 logevent("Forwarded X11 connection terminated");
4484 assert(c->u.x11.s != NULL);
4485 x11_close(c->u.x11.s);
4488 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4489 logevent("Forwarded port closed");
4490 assert(c->u.pfd.s != NULL);
4491 pfd_close(c->u.pfd.s);
4495 c->closes |= (closetype << 2); /* seen this message */
4496 if (!(c->closes & closetype)) {
4497 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4499 c->closes |= closetype; /* sent it too */
4502 if (c->closes == 15) {
4503 del234(ssh->channels, c);
4507 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4508 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4509 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4514 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4516 /* Data sent down one of our channels. */
4517 int i = ssh_pkt_getuint32(pktin);
4520 struct ssh_channel *c;
4522 ssh_pkt_getstring(pktin, &p, &len);
4524 c = find234(ssh->channels, &i, ssh_channelfind);
4529 bufsize = x11_send(c->u.x11.s, p, len);
4532 bufsize = pfd_send(c->u.pfd.s, p, len);
4535 /* Data for an agent message. Buffer it. */
4537 if (c->u.a.lensofar < 4) {
4538 unsigned int l = min(4 - c->u.a.lensofar, len);
4539 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4543 c->u.a.lensofar += l;
4545 if (c->u.a.lensofar == 4) {
4547 4 + GET_32BIT(c->u.a.msglen);
4548 c->u.a.message = snewn(c->u.a.totallen,
4550 memcpy(c->u.a.message, c->u.a.msglen, 4);
4552 if (c->u.a.lensofar >= 4 && len > 0) {
4554 min(c->u.a.totallen - c->u.a.lensofar,
4556 memcpy(c->u.a.message + c->u.a.lensofar, p,
4560 c->u.a.lensofar += l;
4562 if (c->u.a.lensofar == c->u.a.totallen) {
4565 if (agent_query(c->u.a.message,
4568 ssh_agentf_callback, c))
4569 ssh_agentf_callback(c, reply, replylen);
4570 sfree(c->u.a.message);
4571 c->u.a.lensofar = 0;
4574 bufsize = 0; /* agent channels never back up */
4577 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4578 c->v.v1.throttling = 1;
4579 ssh1_throttle(ssh, +1);
4584 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4586 ssh->exitcode = ssh_pkt_getuint32(pktin);
4587 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4588 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4590 * In case `helpful' firewalls or proxies tack
4591 * extra human-readable text on the end of the
4592 * session which we might mistake for another
4593 * encrypted packet, we close the session once
4594 * we've sent EXIT_CONFIRMATION.
4596 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4599 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4600 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4602 struct Packet *pktout = (struct Packet *)data;
4604 unsigned int arg = 0;
4605 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4606 if (i == lenof(ssh_ttymodes)) return;
4607 switch (ssh_ttymodes[i].type) {
4609 arg = ssh_tty_parse_specchar(val);
4612 arg = ssh_tty_parse_boolean(val);
4615 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4616 ssh2_pkt_addbyte(pktout, arg);
4620 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4621 struct Packet *pktin)
4623 crBegin(ssh->do_ssh1_connection_crstate);
4625 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4626 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4627 ssh1_smsg_stdout_stderr_data;
4629 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4630 ssh1_msg_channel_open_confirmation;
4631 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4632 ssh1_msg_channel_open_failure;
4633 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4634 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4635 ssh1_msg_channel_close;
4636 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4637 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4639 if (ssh->cfg.agentfwd && agent_exists()) {
4640 logevent("Requesting agent forwarding");
4641 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4645 if (pktin->type != SSH1_SMSG_SUCCESS
4646 && pktin->type != SSH1_SMSG_FAILURE) {
4647 bombout(("Protocol confusion"));
4649 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4650 logevent("Agent forwarding refused");
4652 logevent("Agent forwarding enabled");
4653 ssh->agentfwd_enabled = TRUE;
4654 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4658 if (ssh->cfg.x11_forward) {
4659 char proto[20], data[64];
4660 logevent("Requesting X11 forwarding");
4661 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4662 data, sizeof(data), ssh->cfg.x11_auth);
4663 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4665 * Note that while we blank the X authentication data here, we don't
4666 * take any special action to blank the start of an X11 channel,
4667 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4668 * without having session blanking enabled is likely to leak your
4669 * cookie into the log.
4671 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4672 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4674 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4675 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4678 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4680 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4685 if (pktin->type != SSH1_SMSG_SUCCESS
4686 && pktin->type != SSH1_SMSG_FAILURE) {
4687 bombout(("Protocol confusion"));
4689 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4690 logevent("X11 forwarding refused");
4692 logevent("X11 forwarding enabled");
4693 ssh->X11_fwd_enabled = TRUE;
4694 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4698 ssh_setup_portfwd(ssh, &ssh->cfg);
4699 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4701 if (!ssh->cfg.nopty) {
4703 /* Unpick the terminal-speed string. */
4704 /* XXX perhaps we should allow no speeds to be sent. */
4705 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4706 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4707 /* Send the pty request. */
4708 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4709 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4710 ssh_pkt_adduint32(pkt, ssh->term_height);
4711 ssh_pkt_adduint32(pkt, ssh->term_width);
4712 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4713 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4714 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4715 ssh1_send_ttymode, (void *)pkt);
4716 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4717 ssh_pkt_adduint32(pkt, ssh->ispeed);
4718 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4719 ssh_pkt_adduint32(pkt, ssh->ospeed);
4720 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4722 ssh->state = SSH_STATE_INTERMED;
4726 if (pktin->type != SSH1_SMSG_SUCCESS
4727 && pktin->type != SSH1_SMSG_FAILURE) {
4728 bombout(("Protocol confusion"));
4730 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4731 c_write_str(ssh, "Server refused to allocate pty\r\n");
4732 ssh->editing = ssh->echoing = 1;
4734 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4735 ssh->ospeed, ssh->ispeed);
4737 ssh->editing = ssh->echoing = 1;
4740 if (ssh->cfg.compression) {
4741 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4745 if (pktin->type != SSH1_SMSG_SUCCESS
4746 && pktin->type != SSH1_SMSG_FAILURE) {
4747 bombout(("Protocol confusion"));
4749 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4750 c_write_str(ssh, "Server refused to compress\r\n");
4752 logevent("Started compression");
4753 ssh->v1_compressing = TRUE;
4754 ssh->cs_comp_ctx = zlib_compress_init();
4755 logevent("Initialised zlib (RFC1950) compression");
4756 ssh->sc_comp_ctx = zlib_decompress_init();
4757 logevent("Initialised zlib (RFC1950) decompression");
4761 * Start the shell or command.
4763 * Special case: if the first-choice command is an SSH-2
4764 * subsystem (hence not usable here) and the second choice
4765 * exists, we fall straight back to that.
4768 char *cmd = ssh->cfg.remote_cmd_ptr;
4770 if (!cmd) cmd = ssh->cfg.remote_cmd;
4772 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4773 cmd = ssh->cfg.remote_cmd_ptr2;
4774 ssh->fallback_cmd = TRUE;
4777 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4779 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4780 logevent("Started session");
4783 ssh->state = SSH_STATE_SESSION;
4784 if (ssh->size_needed)
4785 ssh_size(ssh, ssh->term_width, ssh->term_height);
4786 if (ssh->eof_needed)
4787 ssh_special(ssh, TS_EOF);
4790 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4792 ssh->channels = newtree234(ssh_channelcmp);
4796 * By this point, most incoming packets are already being
4797 * handled by the dispatch table, and we need only pay
4798 * attention to the unusual ones.
4803 if (pktin->type == SSH1_SMSG_SUCCESS) {
4804 /* may be from EXEC_SHELL on some servers */
4805 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4806 /* may be from EXEC_SHELL on some servers
4807 * if no pty is available or in other odd cases. Ignore */
4809 bombout(("Strange packet received: type %d", pktin->type));
4814 int len = min(inlen, 512);
4815 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4816 PKT_INT, len, PKT_DATA, in, len,
4817 PKTT_OTHER, PKT_END);
4828 * Handle the top-level SSH-2 protocol.
4830 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4835 ssh_pkt_getstring(pktin, &msg, &msglen);
4836 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4839 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4841 /* log reason code in disconnect message */
4845 ssh_pkt_getstring(pktin, &msg, &msglen);
4846 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4849 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4851 /* Do nothing, because we're ignoring it! Duhh. */
4854 static void ssh1_protocol_setup(Ssh ssh)
4859 * Most messages are handled by the coroutines.
4861 for (i = 0; i < 256; i++)
4862 ssh->packet_dispatch[i] = NULL;
4865 * These special message types we install handlers for.
4867 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4868 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4869 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4872 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4873 struct Packet *pktin)
4875 unsigned char *in=(unsigned char*)vin;
4876 if (ssh->state == SSH_STATE_CLOSED)
4879 if (pktin && ssh->packet_dispatch[pktin->type]) {
4880 ssh->packet_dispatch[pktin->type](ssh, pktin);
4884 if (!ssh->protocol_initial_phase_done) {
4885 if (do_ssh1_login(ssh, in, inlen, pktin))
4886 ssh->protocol_initial_phase_done = TRUE;
4891 do_ssh1_connection(ssh, in, inlen, pktin);
4895 * Utility routine for decoding comma-separated strings in KEXINIT.
4897 static int in_commasep_string(char *needle, char *haystack, int haylen)
4900 if (!needle || !haystack) /* protect against null pointers */
4902 needlen = strlen(needle);
4905 * Is it at the start of the string?
4907 if (haylen >= needlen && /* haystack is long enough */
4908 !memcmp(needle, haystack, needlen) && /* initial match */
4909 (haylen == needlen || haystack[needlen] == ',')
4910 /* either , or EOS follows */
4914 * If not, search for the next comma and resume after that.
4915 * If no comma found, terminate.
4917 while (haylen > 0 && *haystack != ',')
4918 haylen--, haystack++;
4921 haylen--, haystack++; /* skip over comma itself */
4926 * Similar routine for checking whether we have the first string in a list.
4928 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4931 if (!needle || !haystack) /* protect against null pointers */
4933 needlen = strlen(needle);
4935 * Is it at the start of the string?
4937 if (haylen >= needlen && /* haystack is long enough */
4938 !memcmp(needle, haystack, needlen) && /* initial match */
4939 (haylen == needlen || haystack[needlen] == ',')
4940 /* either , or EOS follows */
4948 * SSH-2 key creation method.
4950 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4951 unsigned char *sessid, char chr,
4952 unsigned char *keyspace)
4955 /* First 20 bytes. */
4957 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4959 SHA_Bytes(&s, H, 20);
4960 SHA_Bytes(&s, &chr, 1);
4961 SHA_Bytes(&s, sessid, 20);
4962 SHA_Final(&s, keyspace);
4963 /* Next 20 bytes. */
4965 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4967 SHA_Bytes(&s, H, 20);
4968 SHA_Bytes(&s, keyspace, 20);
4969 SHA_Final(&s, keyspace + 20);
4973 * Handle the SSH-2 transport layer.
4975 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4976 struct Packet *pktin)
4978 unsigned char *in = (unsigned char *)vin;
4979 struct do_ssh2_transport_state {
4980 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4981 Bignum p, g, e, f, K;
4984 int kex_init_value, kex_reply_value;
4985 const struct ssh_mac **maclist;
4987 const struct ssh2_cipher *cscipher_tobe;
4988 const struct ssh2_cipher *sccipher_tobe;
4989 const struct ssh_mac *csmac_tobe;
4990 const struct ssh_mac *scmac_tobe;
4991 const struct ssh_compress *cscomp_tobe;
4992 const struct ssh_compress *sccomp_tobe;
4993 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4994 int hostkeylen, siglen;
4995 void *hkey; /* actual host key */
4996 unsigned char exchange_hash[20];
4997 int n_preferred_kex;
4998 const struct ssh_kex *preferred_kex[KEX_MAX];
4999 int n_preferred_ciphers;
5000 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
5001 const struct ssh_compress *preferred_comp;
5002 int got_session_id, activated_authconn;
5003 struct Packet *pktout;
5008 crState(do_ssh2_transport_state);
5010 crBegin(ssh->do_ssh2_transport_crstate);
5012 s->cscipher_tobe = s->sccipher_tobe = NULL;
5013 s->csmac_tobe = s->scmac_tobe = NULL;
5014 s->cscomp_tobe = s->sccomp_tobe = NULL;
5016 s->got_session_id = s->activated_authconn = FALSE;
5019 * Be prepared to work around the buggy MAC problem.
5021 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5022 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5024 s->maclist = macs, s->nmacs = lenof(macs);
5027 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
5029 int i, j, commalist_started;
5032 * Set up the preferred key exchange. (NULL => warn below here)
5034 s->n_preferred_kex = 0;
5035 for (i = 0; i < KEX_MAX; i++) {
5036 switch (ssh->cfg.ssh_kexlist[i]) {
5038 s->preferred_kex[s->n_preferred_kex++] =
5039 &ssh_diffiehellman_gex;
5042 s->preferred_kex[s->n_preferred_kex++] =
5043 &ssh_diffiehellman_group14;
5046 s->preferred_kex[s->n_preferred_kex++] =
5047 &ssh_diffiehellman_group1;
5050 /* Flag for later. Don't bother if it's the last in
5052 if (i < KEX_MAX - 1) {
5053 s->preferred_kex[s->n_preferred_kex++] = NULL;
5060 * Set up the preferred ciphers. (NULL => warn below here)
5062 s->n_preferred_ciphers = 0;
5063 for (i = 0; i < CIPHER_MAX; i++) {
5064 switch (ssh->cfg.ssh_cipherlist[i]) {
5065 case CIPHER_BLOWFISH:
5066 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5069 if (ssh->cfg.ssh2_des_cbc) {
5070 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5074 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5077 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5079 case CIPHER_ARCFOUR:
5080 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5083 /* Flag for later. Don't bother if it's the last in
5085 if (i < CIPHER_MAX - 1) {
5086 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5093 * Set up preferred compression.
5095 if (ssh->cfg.compression)
5096 s->preferred_comp = &ssh_zlib;
5098 s->preferred_comp = &ssh_comp_none;
5101 * Enable queueing of outgoing auth- or connection-layer
5102 * packets while we are in the middle of a key exchange.
5104 ssh->queueing = TRUE;
5107 * Flag that KEX is in progress.
5109 ssh->kex_in_progress = TRUE;
5112 * Construct and send our key exchange packet.
5114 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5115 for (i = 0; i < 16; i++)
5116 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5117 /* List key exchange algorithms. */
5118 ssh2_pkt_addstring_start(s->pktout);
5119 commalist_started = 0;
5120 for (i = 0; i < s->n_preferred_kex; i++) {
5121 const struct ssh_kex *k = s->preferred_kex[i];
5122 if (!k) continue; /* warning flag */
5123 if (commalist_started)
5124 ssh2_pkt_addstring_str(s->pktout, ",");
5125 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
5126 commalist_started = 1;
5128 /* List server host key algorithms. */
5129 ssh2_pkt_addstring_start(s->pktout);
5130 for (i = 0; i < lenof(hostkey_algs); i++) {
5131 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5132 if (i < lenof(hostkey_algs) - 1)
5133 ssh2_pkt_addstring_str(s->pktout, ",");
5135 /* List client->server encryption algorithms. */
5136 ssh2_pkt_addstring_start(s->pktout);
5137 commalist_started = 0;
5138 for (i = 0; i < s->n_preferred_ciphers; i++) {
5139 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5140 if (!c) continue; /* warning flag */
5141 for (j = 0; j < c->nciphers; j++) {
5142 if (commalist_started)
5143 ssh2_pkt_addstring_str(s->pktout, ",");
5144 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5145 commalist_started = 1;
5148 /* List server->client encryption algorithms. */
5149 ssh2_pkt_addstring_start(s->pktout);
5150 commalist_started = 0;
5151 for (i = 0; i < s->n_preferred_ciphers; i++) {
5152 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5153 if (!c) continue; /* warning flag */
5154 for (j = 0; j < c->nciphers; j++) {
5155 if (commalist_started)
5156 ssh2_pkt_addstring_str(s->pktout, ",");
5157 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5158 commalist_started = 1;
5161 /* List client->server MAC algorithms. */
5162 ssh2_pkt_addstring_start(s->pktout);
5163 for (i = 0; i < s->nmacs; i++) {
5164 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5165 if (i < s->nmacs - 1)
5166 ssh2_pkt_addstring_str(s->pktout, ",");
5168 /* List server->client MAC algorithms. */
5169 ssh2_pkt_addstring_start(s->pktout);
5170 for (i = 0; i < s->nmacs; i++) {
5171 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5172 if (i < s->nmacs - 1)
5173 ssh2_pkt_addstring_str(s->pktout, ",");
5175 /* List client->server compression algorithms. */
5176 ssh2_pkt_addstring_start(s->pktout);
5177 assert(lenof(compressions) > 1);
5178 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5179 for (i = 0; i < lenof(compressions); i++) {
5180 const struct ssh_compress *c = compressions[i];
5181 if (c != s->preferred_comp) {
5182 ssh2_pkt_addstring_str(s->pktout, ",");
5183 ssh2_pkt_addstring_str(s->pktout, c->name);
5186 /* List server->client compression algorithms. */
5187 ssh2_pkt_addstring_start(s->pktout);
5188 assert(lenof(compressions) > 1);
5189 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5190 for (i = 0; i < lenof(compressions); i++) {
5191 const struct ssh_compress *c = compressions[i];
5192 if (c != s->preferred_comp) {
5193 ssh2_pkt_addstring_str(s->pktout, ",");
5194 ssh2_pkt_addstring_str(s->pktout, c->name);
5197 /* List client->server languages. Empty list. */
5198 ssh2_pkt_addstring_start(s->pktout);
5199 /* List server->client languages. Empty list. */
5200 ssh2_pkt_addstring_start(s->pktout);
5201 /* First KEX packet does _not_ follow, because we're not that brave. */
5202 ssh2_pkt_addbool(s->pktout, FALSE);
5204 ssh2_pkt_adduint32(s->pktout, 0);
5207 s->our_kexinitlen = s->pktout->length - 5;
5208 s->our_kexinit = snewn(s->our_kexinitlen, unsigned char);
5209 memcpy(s->our_kexinit, s->pktout->data + 5, s->our_kexinitlen);
5211 ssh2_pkt_send_noqueue(ssh, s->pktout);
5217 * Now examine the other side's KEXINIT to see what we're up
5221 char *str, *preferred;
5224 if (pktin->type != SSH2_MSG_KEXINIT) {
5225 bombout(("expected key exchange packet from server"));
5229 ssh->hostkey = NULL;
5230 s->cscipher_tobe = NULL;
5231 s->sccipher_tobe = NULL;
5232 s->csmac_tobe = NULL;
5233 s->scmac_tobe = NULL;
5234 s->cscomp_tobe = NULL;
5235 s->sccomp_tobe = NULL;
5236 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5238 pktin->savedpos += 16; /* skip garbage cookie */
5239 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5242 for (i = 0; i < s->n_preferred_kex; i++) {
5243 const struct ssh_kex *k = s->preferred_kex[i];
5247 if (!preferred) preferred = k->name;
5248 if (in_commasep_string(k->name, str, len))
5255 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5256 str ? str : "(null)"));
5260 * Note that the server's guess is considered wrong if it doesn't match
5261 * the first algorithm in our list, even if it's still the algorithm
5264 s->guessok = first_in_commasep_string(preferred, str, len);
5265 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5266 for (i = 0; i < lenof(hostkey_algs); i++) {
5267 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5268 ssh->hostkey = hostkey_algs[i];
5272 s->guessok = s->guessok &&
5273 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5274 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5275 for (i = 0; i < s->n_preferred_ciphers; i++) {
5276 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5278 s->warn_cscipher = TRUE;
5280 for (j = 0; j < c->nciphers; j++) {
5281 if (in_commasep_string(c->list[j]->name, str, len)) {
5282 s->cscipher_tobe = c->list[j];
5287 if (s->cscipher_tobe)
5290 if (!s->cscipher_tobe) {
5291 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5292 str ? str : "(null)"));
5296 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5297 for (i = 0; i < s->n_preferred_ciphers; i++) {
5298 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5300 s->warn_sccipher = TRUE;
5302 for (j = 0; j < c->nciphers; j++) {
5303 if (in_commasep_string(c->list[j]->name, str, len)) {
5304 s->sccipher_tobe = c->list[j];
5309 if (s->sccipher_tobe)
5312 if (!s->sccipher_tobe) {
5313 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5314 str ? str : "(null)"));
5318 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5319 for (i = 0; i < s->nmacs; i++) {
5320 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5321 s->csmac_tobe = s->maclist[i];
5325 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5326 for (i = 0; i < s->nmacs; i++) {
5327 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5328 s->scmac_tobe = s->maclist[i];
5332 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5333 for (i = 0; i < lenof(compressions) + 1; i++) {
5334 const struct ssh_compress *c =
5335 i == 0 ? s->preferred_comp : compressions[i - 1];
5336 if (in_commasep_string(c->name, str, len)) {
5341 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5342 for (i = 0; i < lenof(compressions) + 1; i++) {
5343 const struct ssh_compress *c =
5344 i == 0 ? s->preferred_comp : compressions[i - 1];
5345 if (in_commasep_string(c->name, str, len)) {
5350 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5351 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5352 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5355 ssh_set_frozen(ssh, 1);
5356 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5358 ssh_dialog_callback, ssh);
5359 if (s->dlgret < 0) {
5363 bombout(("Unexpected data from server while"
5364 " waiting for user response"));
5367 } while (pktin || inlen > 0);
5368 s->dlgret = ssh->user_response;
5370 ssh_set_frozen(ssh, 0);
5371 if (s->dlgret == 0) {
5372 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5378 if (s->warn_cscipher) {
5379 ssh_set_frozen(ssh, 1);
5380 s->dlgret = askalg(ssh->frontend,
5381 "client-to-server cipher",
5382 s->cscipher_tobe->name,
5383 ssh_dialog_callback, ssh);
5384 if (s->dlgret < 0) {
5388 bombout(("Unexpected data from server while"
5389 " waiting for user response"));
5392 } while (pktin || inlen > 0);
5393 s->dlgret = ssh->user_response;
5395 ssh_set_frozen(ssh, 0);
5396 if (s->dlgret == 0) {
5397 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5403 if (s->warn_sccipher) {
5404 ssh_set_frozen(ssh, 1);
5405 s->dlgret = askalg(ssh->frontend,
5406 "server-to-client cipher",
5407 s->sccipher_tobe->name,
5408 ssh_dialog_callback, ssh);
5409 if (s->dlgret < 0) {
5413 bombout(("Unexpected data from server while"
5414 " waiting for user response"));
5417 } while (pktin || inlen > 0);
5418 s->dlgret = ssh->user_response;
5420 ssh_set_frozen(ssh, 0);
5421 if (s->dlgret == 0) {
5422 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5428 SHA_Init(&ssh->exhash);
5429 sha_string(&ssh->exhash, ssh->v_c, strlen(ssh->v_c));
5430 sha_string(&ssh->exhash, ssh->v_s, strlen(ssh->v_s));
5431 sha_string(&ssh->exhash, s->our_kexinit, s->our_kexinitlen);
5432 sfree(s->our_kexinit);
5433 if (pktin->length > 5)
5434 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
5437 if (s->ignorepkt) /* first_kex_packet_follows */
5438 crWaitUntil(pktin); /* Ignore packet */
5442 * Work out the number of bits of key we will need from the key
5443 * exchange. We start with the maximum key length of either
5449 csbits = s->cscipher_tobe->keylen;
5450 scbits = s->sccipher_tobe->keylen;
5451 s->nbits = (csbits > scbits ? csbits : scbits);
5453 /* The keys only have 160-bit entropy, since they're based on
5454 * a SHA-1 hash. So cap the key size at 160 bits. */
5459 * If we're doing Diffie-Hellman group exchange, start by
5460 * requesting a group.
5462 if (!ssh->kex->pdata) {
5463 logevent("Doing Diffie-Hellman group exchange");
5464 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5466 * Work out how big a DH group we will need to allow that
5469 s->pbits = 512 << ((s->nbits - 1) / 64);
5470 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5471 ssh2_pkt_adduint32(s->pktout, s->pbits);
5472 ssh2_pkt_send_noqueue(ssh, s->pktout);
5475 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5476 bombout(("expected key exchange group packet from server"));
5479 s->p = ssh2_pkt_getmp(pktin);
5480 s->g = ssh2_pkt_getmp(pktin);
5481 if (!s->p || !s->g) {
5482 bombout(("unable to read mp-ints from incoming group packet"));
5485 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5486 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5487 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5489 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5490 ssh->kex_ctx = dh_setup_group(ssh->kex);
5491 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5492 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5493 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5494 ssh->kex->groupname);
5497 logevent("Doing Diffie-Hellman key exchange");
5499 * Now generate and send e for Diffie-Hellman.
5501 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5502 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5503 s->pktout = ssh2_pkt_init(s->kex_init_value);
5504 ssh2_pkt_addmp(s->pktout, s->e);
5505 ssh2_pkt_send_noqueue(ssh, s->pktout);
5507 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5509 if (pktin->type != s->kex_reply_value) {
5510 bombout(("expected key exchange reply packet from server"));
5513 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5514 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5515 s->f = ssh2_pkt_getmp(pktin);
5517 bombout(("unable to parse key exchange reply packet"));
5520 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5522 s->K = dh_find_K(ssh->kex_ctx, s->f);
5524 /* We assume everything from now on will be quick, and it might
5525 * involve user interaction. */
5526 set_busy_status(ssh->frontend, BUSY_NOT);
5528 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5529 if (ssh->kex == &ssh_diffiehellman_gex) {
5530 sha_uint32(&ssh->exhash, s->pbits);
5531 sha_mpint(&ssh->exhash, s->p);
5532 sha_mpint(&ssh->exhash, s->g);
5534 sha_mpint(&ssh->exhash, s->e);
5535 sha_mpint(&ssh->exhash, s->f);
5536 sha_mpint(&ssh->exhash, s->K);
5537 SHA_Final(&ssh->exhash, s->exchange_hash);
5539 dh_cleanup(ssh->kex_ctx);
5540 ssh->kex_ctx = NULL;
5543 debug(("Exchange hash is:\n"));
5544 dmemdump(s->exchange_hash, 20);
5547 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5549 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5550 (char *)s->exchange_hash, 20)) {
5551 bombout(("Server's host key did not match the signature supplied"));
5556 * Authenticate remote host: verify host key. (We've already
5557 * checked the signature of the exchange hash.)
5559 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5560 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5561 ssh_set_frozen(ssh, 1);
5562 s->dlgret = verify_ssh_host_key(ssh->frontend,
5563 ssh->savedhost, ssh->savedport,
5564 ssh->hostkey->keytype, s->keystr,
5566 ssh_dialog_callback, ssh);
5567 if (s->dlgret < 0) {
5571 bombout(("Unexpected data from server while waiting"
5572 " for user host key response"));
5575 } while (pktin || inlen > 0);
5576 s->dlgret = ssh->user_response;
5578 ssh_set_frozen(ssh, 0);
5579 if (s->dlgret == 0) {
5580 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5584 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5585 logevent("Host key fingerprint is:");
5586 logevent(s->fingerprint);
5588 sfree(s->fingerprint);
5590 ssh->hostkey->freekey(s->hkey);
5593 * The exchange hash from the very first key exchange is also
5594 * the session id, used in session key construction and
5597 if (!s->got_session_id) {
5598 memcpy(ssh->v2_session_id, s->exchange_hash,
5599 sizeof(s->exchange_hash));
5600 s->got_session_id = TRUE;
5604 * Send SSH2_MSG_NEWKEYS.
5606 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5607 ssh2_pkt_send_noqueue(ssh, s->pktout);
5608 ssh->outgoing_data_size = 0; /* start counting from here */
5611 * We've sent client NEWKEYS, so create and initialise
5612 * client-to-server session keys.
5614 if (ssh->cs_cipher_ctx)
5615 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5616 ssh->cscipher = s->cscipher_tobe;
5617 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5619 if (ssh->cs_mac_ctx)
5620 ssh->csmac->free_context(ssh->cs_mac_ctx);
5621 ssh->csmac = s->csmac_tobe;
5622 ssh->cs_mac_ctx = ssh->csmac->make_context();
5624 if (ssh->cs_comp_ctx)
5625 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5626 ssh->cscomp = s->cscomp_tobe;
5627 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5630 * Set IVs on client-to-server keys. Here we use the exchange
5631 * hash from the _first_ key exchange.
5634 unsigned char keyspace[40];
5635 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5636 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5637 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5638 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5639 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5640 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5643 logeventf(ssh, "Initialised %.200s client->server encryption",
5644 ssh->cscipher->text_name);
5645 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5646 ssh->csmac->text_name);
5647 if (ssh->cscomp->text_name)
5648 logeventf(ssh, "Initialised %s compression",
5649 ssh->cscomp->text_name);
5652 * Now our end of the key exchange is complete, we can send all
5653 * our queued higher-layer packets.
5655 ssh->queueing = FALSE;
5656 ssh2_pkt_queuesend(ssh);
5659 * Expect SSH2_MSG_NEWKEYS from server.
5662 if (pktin->type != SSH2_MSG_NEWKEYS) {
5663 bombout(("expected new-keys packet from server"));
5666 ssh->incoming_data_size = 0; /* start counting from here */
5669 * We've seen server NEWKEYS, so create and initialise
5670 * server-to-client session keys.
5672 if (ssh->sc_cipher_ctx)
5673 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5674 ssh->sccipher = s->sccipher_tobe;
5675 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5677 if (ssh->sc_mac_ctx)
5678 ssh->scmac->free_context(ssh->sc_mac_ctx);
5679 ssh->scmac = s->scmac_tobe;
5680 ssh->sc_mac_ctx = ssh->scmac->make_context();
5682 if (ssh->sc_comp_ctx)
5683 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5684 ssh->sccomp = s->sccomp_tobe;
5685 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5688 * Set IVs on server-to-client keys. Here we use the exchange
5689 * hash from the _first_ key exchange.
5692 unsigned char keyspace[40];
5693 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5694 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5695 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5696 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5697 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5698 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5700 logeventf(ssh, "Initialised %.200s server->client encryption",
5701 ssh->sccipher->text_name);
5702 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5703 ssh->scmac->text_name);
5704 if (ssh->sccomp->text_name)
5705 logeventf(ssh, "Initialised %s decompression",
5706 ssh->sccomp->text_name);
5709 * Free key exchange data.
5713 if (ssh->kex == &ssh_diffiehellman_gex) {
5719 * Key exchange is over. Loop straight back round if we have a
5720 * deferred rekey reason.
5722 if (ssh->deferred_rekey_reason) {
5723 logevent(ssh->deferred_rekey_reason);
5725 ssh->deferred_rekey_reason = NULL;
5726 goto begin_key_exchange;
5730 * Otherwise, schedule a timer for our next rekey.
5732 ssh->kex_in_progress = FALSE;
5733 ssh->last_rekey = GETTICKCOUNT();
5734 if (ssh->cfg.ssh_rekey_time != 0)
5735 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5739 * If this is the first key exchange phase, we must pass the
5740 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5741 * wants to see it but because it will need time to initialise
5742 * itself before it sees an actual packet. In subsequent key
5743 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5744 * it would only confuse the layer above.
5746 if (s->activated_authconn) {
5749 s->activated_authconn = TRUE;
5752 * Now we're encrypting. Begin returning 1 to the protocol main
5753 * function so that other things can run on top of the
5754 * transport. If we ever see a KEXINIT, we must go back to the
5757 * We _also_ go back to the start if we see pktin==NULL and
5758 * inlen==-1, because this is a special signal meaning
5759 * `initiate client-driven rekey', and `in' contains a message
5760 * giving the reason for the rekey.
5762 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5763 (!pktin && inlen == -1))) {
5768 logevent("Server initiated key re-exchange");
5771 * Special case: if the server bug is set that doesn't
5772 * allow rekeying, we give a different log message and
5773 * continue waiting. (If such a server _initiates_ a rekey,
5774 * we process it anyway!)
5776 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5777 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5779 /* Reset the counters, so that at least this message doesn't
5780 * hit the event log _too_ often. */
5781 ssh->outgoing_data_size = 0;
5782 ssh->incoming_data_size = 0;
5783 if (ssh->cfg.ssh_rekey_time != 0) {
5785 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5788 goto wait_for_rekey; /* this is utterly horrid */
5790 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5793 goto begin_key_exchange;
5799 * Add data to an SSH-2 channel output buffer.
5801 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5804 bufchain_add(&c->v.v2.outbuffer, buf, len);
5808 * Attempt to send data on an SSH-2 channel.
5810 static int ssh2_try_send(struct ssh_channel *c)
5813 struct Packet *pktout;
5815 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5818 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5819 if ((unsigned)len > c->v.v2.remwindow)
5820 len = c->v.v2.remwindow;
5821 if ((unsigned)len > c->v.v2.remmaxpkt)
5822 len = c->v.v2.remmaxpkt;
5823 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5824 ssh2_pkt_adduint32(pktout, c->remoteid);
5825 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5826 ssh2_pkt_addstring_start(pktout);
5827 ssh2_pkt_addstring_data(pktout, data, len);
5828 end_log_omission(ssh, pktout);
5829 ssh2_pkt_send(ssh, pktout);
5830 bufchain_consume(&c->v.v2.outbuffer, len);
5831 c->v.v2.remwindow -= len;
5835 * After having sent as much data as we can, return the amount
5838 return bufchain_size(&c->v.v2.outbuffer);
5841 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5845 return; /* don't send on closing channels */
5846 bufsize = ssh2_try_send(c);
5849 case CHAN_MAINSESSION:
5850 /* stdin need not receive an unthrottle
5851 * notification since it will be polled */
5854 x11_unthrottle(c->u.x11.s);
5857 /* agent sockets are request/response and need no
5858 * buffer management */
5861 pfd_unthrottle(c->u.pfd.s);
5868 * Potentially enlarge the window on an SSH-2 channel.
5870 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5875 * Never send WINDOW_ADJUST for a channel that the remote side
5876 * already thinks it's closed; there's no point, since it won't
5877 * be sending any more data anyway.
5883 * Only send a WINDOW_ADJUST if there's significantly more window
5884 * available than the other end thinks there is. This saves us
5885 * sending a WINDOW_ADJUST for every character in a shell session.
5887 * "Significant" is arbitrarily defined as half the window size.
5889 if (newwin > c->v.v2.locwindow * 2) {
5890 struct Packet *pktout;
5892 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5893 ssh2_pkt_adduint32(pktout, c->remoteid);
5894 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5895 ssh2_pkt_send(ssh, pktout);
5896 c->v.v2.locwindow = newwin;
5900 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5902 unsigned i = ssh_pkt_getuint32(pktin);
5903 struct ssh_channel *c;
5904 c = find234(ssh->channels, &i, ssh_channelfind);
5905 if (c && !c->closes) {
5906 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5907 ssh2_try_send_and_unthrottle(c);
5911 static void ssh2_msg_channel_data(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);
5919 return; /* nonexistent channel */
5920 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5921 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5922 return; /* extended but not stderr */
5923 ssh_pkt_getstring(pktin, &data, &length);
5926 c->v.v2.locwindow -= length;
5928 case CHAN_MAINSESSION:
5930 from_backend(ssh->frontend, pktin->type ==
5931 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5935 bufsize = x11_send(c->u.x11.s, data, length);
5938 bufsize = pfd_send(c->u.pfd.s, data, length);
5941 while (length > 0) {
5942 if (c->u.a.lensofar < 4) {
5943 unsigned int l = min(4 - c->u.a.lensofar, length);
5944 memcpy(c->u.a.msglen + c->u.a.lensofar,
5948 c->u.a.lensofar += l;
5950 if (c->u.a.lensofar == 4) {
5952 4 + GET_32BIT(c->u.a.msglen);
5953 c->u.a.message = snewn(c->u.a.totallen,
5955 memcpy(c->u.a.message, c->u.a.msglen, 4);
5957 if (c->u.a.lensofar >= 4 && length > 0) {
5959 min(c->u.a.totallen - c->u.a.lensofar,
5961 memcpy(c->u.a.message + c->u.a.lensofar,
5965 c->u.a.lensofar += l;
5967 if (c->u.a.lensofar == c->u.a.totallen) {
5970 if (agent_query(c->u.a.message,
5973 ssh_agentf_callback, c))
5974 ssh_agentf_callback(c, reply, replylen);
5975 sfree(c->u.a.message);
5976 c->u.a.lensofar = 0;
5983 * If we are not buffering too much data,
5984 * enlarge the window again at the remote side.
5986 if (bufsize < OUR_V2_WINSIZE)
5987 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5991 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5993 unsigned i = ssh_pkt_getuint32(pktin);
5994 struct ssh_channel *c;
5996 c = find234(ssh->channels, &i, ssh_channelfind);
5998 return; /* nonexistent channel */
6000 if (c->type == CHAN_X11) {
6002 * Remote EOF on an X11 channel means we should
6003 * wrap up and close the channel ourselves.
6005 x11_close(c->u.x11.s);
6007 } else if (c->type == CHAN_AGENT) {
6009 } else if (c->type == CHAN_SOCKDATA) {
6010 pfd_close(c->u.pfd.s);
6015 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6017 unsigned i = ssh_pkt_getuint32(pktin);
6018 struct ssh_channel *c;
6019 struct Packet *pktout;
6021 c = find234(ssh->channels, &i, ssh_channelfind);
6022 if (!c || c->halfopen) {
6023 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6024 c ? "half-open" : "nonexistent", i));
6027 /* Do pre-close processing on the channel. */
6029 case CHAN_MAINSESSION:
6030 ssh->mainchan = NULL;
6031 update_specials_menu(ssh->frontend);
6034 if (c->u.x11.s != NULL)
6035 x11_close(c->u.x11.s);
6042 if (c->u.pfd.s != NULL)
6043 pfd_close(c->u.pfd.s);
6047 if (c->closes == 0) {
6048 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6049 ssh2_pkt_adduint32(pktout, c->remoteid);
6050 ssh2_pkt_send(ssh, pktout);
6052 del234(ssh->channels, c);
6053 bufchain_clear(&c->v.v2.outbuffer);
6057 * See if that was the last channel left open.
6058 * (This is only our termination condition if we're
6059 * not running in -N mode.)
6061 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6063 * We used to send SSH_MSG_DISCONNECT here,
6064 * because I'd believed that _every_ conforming
6065 * SSH-2 connection had to end with a disconnect
6066 * being sent by at least one side; apparently
6067 * I was wrong and it's perfectly OK to
6068 * unceremoniously slam the connection shut
6069 * when you're done, and indeed OpenSSH feels
6070 * this is more polite than sending a
6071 * DISCONNECT. So now we don't.
6073 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6077 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6079 unsigned i = ssh_pkt_getuint32(pktin);
6080 struct ssh_channel *c;
6081 struct Packet *pktout;
6083 c = find234(ssh->channels, &i, ssh_channelfind);
6085 return; /* nonexistent channel */
6086 if (c->type != CHAN_SOCKDATA_DORMANT)
6087 return; /* dunno why they're confirming this */
6088 c->remoteid = ssh_pkt_getuint32(pktin);
6089 c->halfopen = FALSE;
6090 c->type = CHAN_SOCKDATA;
6091 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6092 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6094 pfd_confirm(c->u.pfd.s);
6097 * We have a pending close on this channel,
6098 * which we decided on before the server acked
6099 * the channel open. So now we know the
6100 * remoteid, we can close it again.
6102 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6103 ssh2_pkt_adduint32(pktout, c->remoteid);
6104 ssh2_pkt_send(ssh, pktout);
6108 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6110 static const char *const reasons[] = {
6111 "<unknown reason code>",
6112 "Administratively prohibited",
6114 "Unknown channel type",
6115 "Resource shortage",
6117 unsigned i = ssh_pkt_getuint32(pktin);
6118 unsigned reason_code;
6119 char *reason_string;
6121 struct ssh_channel *c;
6122 c = find234(ssh->channels, &i, ssh_channelfind);
6124 return; /* nonexistent channel */
6125 if (c->type != CHAN_SOCKDATA_DORMANT)
6126 return; /* dunno why they're failing this */
6128 reason_code = ssh_pkt_getuint32(pktin);
6129 if (reason_code >= lenof(reasons))
6130 reason_code = 0; /* ensure reasons[reason_code] in range */
6131 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6132 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6133 reasons[reason_code], reason_length, reason_string);
6135 pfd_close(c->u.pfd.s);
6137 del234(ssh->channels, c);
6141 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6145 int typelen, want_reply;
6146 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6147 struct ssh_channel *c;
6148 struct Packet *pktout;
6150 localid = ssh_pkt_getuint32(pktin);
6151 ssh_pkt_getstring(pktin, &type, &typelen);
6152 want_reply = ssh2_pkt_getbool(pktin);
6155 * First, check that the channel exists. Otherwise,
6156 * we can instantly disconnect with a rude message.
6158 c = find234(ssh->channels, &localid, ssh_channelfind);
6160 char *buf = dupprintf("Received channel request for nonexistent"
6161 " channel %d", localid);
6162 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6168 * Having got the channel number, we now look at
6169 * the request type string to see if it's something
6172 if (c == ssh->mainchan) {
6174 * We recognise "exit-status" and "exit-signal" on
6175 * the primary channel.
6177 if (typelen == 11 &&
6178 !memcmp(type, "exit-status", 11)) {
6180 ssh->exitcode = ssh_pkt_getuint32(pktin);
6181 logeventf(ssh, "Server sent command exit status %d",
6183 reply = SSH2_MSG_CHANNEL_SUCCESS;
6185 } else if (typelen == 11 &&
6186 !memcmp(type, "exit-signal", 11)) {
6188 int is_plausible = TRUE, is_int = FALSE;
6189 char *fmt_sig = "", *fmt_msg = "";
6191 int msglen = 0, core = FALSE;
6192 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6193 * provide an `int' for the signal, despite its
6194 * having been a `string' in the drafts since at
6195 * least 2001. (Fixed in session.c 1.147.) Try to
6196 * infer which we can safely parse it as. */
6198 unsigned char *p = pktin->body +
6200 long len = pktin->length - pktin->savedpos;
6201 unsigned long num = GET_32BIT(p); /* what is it? */
6202 /* If it's 0, it hardly matters; assume string */
6206 int maybe_int = FALSE, maybe_str = FALSE;
6207 #define CHECK_HYPOTHESIS(offset, result) \
6210 if (q >= 0 && q+4 <= len) { \
6211 q = q + 4 + GET_32BIT(p+q); \
6212 if (q >= 0 && q+4 <= len && \
6213 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6217 CHECK_HYPOTHESIS(4+1, maybe_int);
6218 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6219 #undef CHECK_HYPOTHESIS
6220 if (maybe_int && !maybe_str)
6222 else if (!maybe_int && maybe_str)
6225 /* Crikey. Either or neither. Panic. */
6226 is_plausible = FALSE;
6231 /* Old non-standard OpenSSH. */
6232 int signum = ssh_pkt_getuint32(pktin);
6233 fmt_sig = dupprintf(" %d", signum);
6235 /* As per the drafts. */
6238 ssh_pkt_getstring(pktin, &sig, &siglen);
6239 /* Signal name isn't supposed to be blank, but
6240 * let's cope gracefully if it is. */
6242 fmt_sig = dupprintf(" \"%.*s\"",
6246 core = ssh2_pkt_getbool(pktin);
6247 ssh_pkt_getstring(pktin, &msg, &msglen);
6249 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6251 /* ignore lang tag */
6252 } /* else don't attempt to parse */
6253 logeventf(ssh, "Server exited on signal%s%s%s",
6254 fmt_sig, core ? " (core dumped)" : "",
6256 if (*fmt_sig) sfree(fmt_sig);
6257 if (*fmt_msg) sfree(fmt_msg);
6258 reply = SSH2_MSG_CHANNEL_SUCCESS;
6263 * This is a channel request we don't know
6264 * about, so we now either ignore the request
6265 * or respond with CHANNEL_FAILURE, depending
6268 reply = SSH2_MSG_CHANNEL_FAILURE;
6271 pktout = ssh2_pkt_init(reply);
6272 ssh2_pkt_adduint32(pktout, c->remoteid);
6273 ssh2_pkt_send(ssh, pktout);
6277 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6280 int typelen, want_reply;
6281 struct Packet *pktout;
6283 ssh_pkt_getstring(pktin, &type, &typelen);
6284 want_reply = ssh2_pkt_getbool(pktin);
6287 * We currently don't support any global requests
6288 * at all, so we either ignore the request or
6289 * respond with REQUEST_FAILURE, depending on
6293 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6294 ssh2_pkt_send(ssh, pktout);
6298 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6306 struct ssh_channel *c;
6307 unsigned remid, winsize, pktsize;
6308 struct Packet *pktout;
6310 ssh_pkt_getstring(pktin, &type, &typelen);
6311 c = snew(struct ssh_channel);
6314 remid = ssh_pkt_getuint32(pktin);
6315 winsize = ssh_pkt_getuint32(pktin);
6316 pktsize = ssh_pkt_getuint32(pktin);
6318 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6321 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6322 addrstr = snewn(peeraddrlen+1, char);
6323 memcpy(addrstr, peeraddr, peeraddrlen);
6324 addrstr[peeraddrlen] = '\0';
6325 peerport = ssh_pkt_getuint32(pktin);
6327 logeventf(ssh, "Received X11 connect request from %s:%d",
6330 if (!ssh->X11_fwd_enabled)
6331 error = "X11 forwarding is not enabled";
6332 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6333 ssh->x11auth, addrstr, peerport,
6334 &ssh->cfg) != NULL) {
6335 error = "Unable to open an X11 connection";
6337 logevent("Opening X11 forward connection succeeded");
6342 } else if (typelen == 15 &&
6343 !memcmp(type, "forwarded-tcpip", 15)) {
6344 struct ssh_rportfwd pf, *realpf;
6347 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6348 pf.sport = ssh_pkt_getuint32(pktin);
6349 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6350 peerport = ssh_pkt_getuint32(pktin);
6351 realpf = find234(ssh->rportfwds, &pf, NULL);
6352 logeventf(ssh, "Received remote port %d open request "
6353 "from %s:%d", pf.sport, peeraddr, peerport);
6354 if (realpf == NULL) {
6355 error = "Remote port is not recognised";
6357 const char *e = pfd_newconnect(&c->u.pfd.s,
6361 realpf->pfrec->addressfamily);
6362 logeventf(ssh, "Attempting to forward remote port to "
6363 "%s:%d", realpf->dhost, realpf->dport);
6365 logeventf(ssh, "Port open failed: %s", e);
6366 error = "Port open failed";
6368 logevent("Forwarded port opened successfully");
6369 c->type = CHAN_SOCKDATA;
6372 } else if (typelen == 22 &&
6373 !memcmp(type, "auth-agent@openssh.com", 22)) {
6374 if (!ssh->agentfwd_enabled)
6375 error = "Agent forwarding is not enabled";
6377 c->type = CHAN_AGENT; /* identify channel type */
6378 c->u.a.lensofar = 0;
6381 error = "Unsupported channel type requested";
6384 c->remoteid = remid;
6385 c->halfopen = FALSE;
6387 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6388 ssh2_pkt_adduint32(pktout, c->remoteid);
6389 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6390 ssh2_pkt_addstring(pktout, error);
6391 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6392 ssh2_pkt_send(ssh, pktout);
6393 logeventf(ssh, "Rejected channel open: %s", error);
6396 c->localid = alloc_channel_id(ssh);
6398 c->v.v2.locwindow = OUR_V2_WINSIZE;
6399 c->v.v2.remwindow = winsize;
6400 c->v.v2.remmaxpkt = pktsize;
6401 bufchain_init(&c->v.v2.outbuffer);
6402 add234(ssh->channels, c);
6403 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6404 ssh2_pkt_adduint32(pktout, c->remoteid);
6405 ssh2_pkt_adduint32(pktout, c->localid);
6406 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6407 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6408 ssh2_pkt_send(ssh, pktout);
6413 * Buffer banner messages for later display at some convenient point.
6415 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6417 /* Arbitrary limit to prevent unbounded inflation of buffer */
6418 if (bufchain_size(&ssh->banner) <= 131072) {
6419 char *banner = NULL;
6421 ssh_pkt_getstring(pktin, &banner, &size);
6423 bufchain_add(&ssh->banner, banner, size);
6427 /* Helper function to deal with sending tty modes for "pty-req" */
6428 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6430 struct Packet *pktout = (struct Packet *)data;
6432 unsigned int arg = 0;
6433 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6434 if (i == lenof(ssh_ttymodes)) return;
6435 switch (ssh_ttymodes[i].type) {
6437 arg = ssh_tty_parse_specchar(val);
6440 arg = ssh_tty_parse_boolean(val);
6443 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6444 ssh2_pkt_adduint32(pktout, arg);
6448 * Handle the SSH-2 userauth and connection layers.
6450 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6451 struct Packet *pktin)
6453 struct do_ssh2_authconn_state {
6455 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6457 AUTH_KEYBOARD_INTERACTIVE
6461 AUTH_TYPE_PUBLICKEY,
6462 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6463 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6465 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6466 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6468 int done_service_req;
6469 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6470 int tried_pubkey_config, tried_agent;
6471 int kbd_inter_running, kbd_inter_refused;
6473 int num_prompts, curr_prompt, echo;
6478 void *publickey_blob;
6479 int publickey_bloblen;
6480 unsigned char request[5], *response, *p;
6484 char *pkblob, *alg, *commentp;
6485 int pklen, alglen, commentlen;
6486 int siglen, retlen, len;
6487 char *q, *agentreq, *ret;
6489 int num_env, env_left, env_ok;
6490 struct Packet *pktout;
6492 crState(do_ssh2_authconn_state);
6494 crBegin(ssh->do_ssh2_authconn_crstate);
6496 s->done_service_req = FALSE;
6497 s->we_are_in = FALSE;
6498 if (!ssh->cfg.ssh_no_userauth) {
6500 * Request userauth protocol, and await a response to it.
6502 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6503 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6504 ssh2_pkt_send(ssh, s->pktout);
6505 crWaitUntilV(pktin);
6506 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6507 s->done_service_req = TRUE;
6509 if (!s->done_service_req) {
6511 * Request connection protocol directly, without authentication.
6513 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6514 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6515 ssh2_pkt_send(ssh, s->pktout);
6516 crWaitUntilV(pktin);
6517 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6518 s->we_are_in = TRUE; /* no auth required */
6520 bombout(("Server refused service request"));
6526 * We repeat this whole loop, including the username prompt,
6527 * until we manage a successful authentication. If the user
6528 * types the wrong _password_, they can be sent back to the
6529 * beginning to try another username, if this is configured on.
6530 * (If they specify a username in the config, they are never
6531 * asked, even if they do give a wrong password.)
6533 * I think this best serves the needs of
6535 * - the people who have no configuration, no keys, and just
6536 * want to try repeated (username,password) pairs until they
6537 * type both correctly
6539 * - people who have keys and configuration but occasionally
6540 * need to fall back to passwords
6542 * - people with a key held in Pageant, who might not have
6543 * logged in to a particular machine before; so they want to
6544 * type a username, and then _either_ their key will be
6545 * accepted, _or_ they will type a password. If they mistype
6546 * the username they will want to be able to get back and
6549 s->username[0] = '\0';
6550 s->got_username = FALSE;
6551 bufchain_init(&ssh->banner);
6552 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6553 ssh2_msg_userauth_banner;
6554 while (!s->we_are_in) {
6558 if (s->got_username && !ssh->cfg.change_username) {
6560 * We got a username last time round this loop, and
6561 * with change_username turned off we don't try to get
6564 } else if (!*ssh->cfg.username) {
6565 if (ssh_get_line && !ssh_getline_pw_only) {
6566 if (!ssh_get_line("login as: ",
6567 s->username, sizeof(s->username), FALSE)) {
6569 * get_line failed to get a username.
6572 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
6576 int ret; /* need not be saved across crReturn */
6577 c_write_str(ssh, "login as: ");
6579 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6581 crWaitUntilV(!pktin);
6582 ret = process_userpass_input(ssh, in, inlen);
6586 c_write_str(ssh, "\r\n");
6588 s->username[strcspn(s->username, "\n\r")] = '\0';
6591 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6592 s->username[sizeof(s->username)-1] = '\0';
6593 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6594 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6595 c_write_str(ssh, stuff);
6599 s->got_username = TRUE;
6602 * Send an authentication request using method "none": (a)
6603 * just in case it succeeds, and (b) so that we know what
6604 * authentication methods we can usefully try next.
6606 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6608 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6609 ssh2_pkt_addstring(s->pktout, s->username);
6610 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6611 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6612 ssh2_pkt_send(ssh, s->pktout);
6613 s->type = AUTH_TYPE_NONE;
6615 s->we_are_in = FALSE;
6617 s->tried_pubkey_config = FALSE;
6618 s->tried_agent = FALSE;
6619 s->kbd_inter_running = FALSE;
6620 s->kbd_inter_refused = FALSE;
6621 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6622 if (!filename_is_null(ssh->cfg.keyfile)) {
6624 logeventf(ssh, "Reading private key file \"%.150s\"",
6625 filename_to_str(&ssh->cfg.keyfile));
6626 keytype = key_type(&ssh->cfg.keyfile);
6627 if (keytype == SSH_KEYTYPE_SSH2) {
6629 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6630 &s->publickey_bloblen, NULL);
6633 logeventf(ssh, "Unable to use this key file (%s)",
6634 key_type_to_str(keytype));
6635 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6637 filename_to_str(&ssh->cfg.keyfile),
6638 key_type_to_str(keytype));
6639 c_write_str(ssh, msgbuf);
6641 s->publickey_blob = NULL;
6644 s->publickey_blob = NULL;
6648 * Wait for the result of the last authentication request.
6651 crWaitUntilV(pktin);
6653 * Now is a convenient point to spew any banner material
6654 * that we've accumulated. (This should ensure that when
6655 * we exit the auth loop, we haven't any left to deal
6659 int size = bufchain_size(&ssh->banner);
6661 * Don't show the banner if we're operating in
6662 * non-verbose non-interactive mode. (It's probably
6663 * a script, which means nobody will read the
6664 * banner _anyway_, and moreover the printing of
6665 * the banner will screw up processing on the
6666 * output of (say) plink.)
6668 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
6669 char *banner = snewn(size, char);
6670 bufchain_fetch(&ssh->banner, banner, size);
6671 c_write_untrusted(ssh, banner, size);
6674 bufchain_clear(&ssh->banner);
6676 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6677 logevent("Access granted");
6678 s->we_are_in = TRUE;
6682 if (s->kbd_inter_running &&
6683 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6685 * This is either a further set-of-prompts packet
6686 * in keyboard-interactive authentication, or it's
6687 * the same one and we came back here with `gotit'
6688 * set. In the former case, we must reset the
6689 * curr_prompt variable.
6693 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6694 /* FIXME: perhaps we should support this? */
6695 bombout(("PASSWD_CHANGEREQ not yet supported"));
6697 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6698 bombout(("Strange packet received during authentication: type %d",
6706 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6707 * we can look at the string in it and know what we can
6708 * helpfully try next.
6710 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6713 ssh_pkt_getstring(pktin, &methods, &methlen);
6714 s->kbd_inter_running = FALSE;
6715 if (!ssh2_pkt_getbool(pktin)) {
6717 * We have received an unequivocal Access
6718 * Denied. This can translate to a variety of
6721 * - if we'd just tried "none" authentication,
6722 * it's not worth printing anything at all
6724 * - if we'd just tried a public key _offer_,
6725 * the message should be "Server refused our
6726 * key" (or no message at all if the key
6727 * came from Pageant)
6729 * - if we'd just tried anything else, the
6730 * message really should be "Access denied".
6732 * Additionally, if we'd just tried password
6733 * authentication, we should break out of this
6734 * whole loop so as to go back to the username
6735 * prompt (iff we're configured to allow
6736 * username change attempts).
6738 if (s->type == AUTH_TYPE_NONE) {
6740 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6741 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6742 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6743 c_write_str(ssh, "Server refused our key\r\n");
6744 logevent("Server refused public key");
6745 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6746 /* server declined keyboard-interactive; ignore */
6748 c_write_str(ssh, "Access denied\r\n");
6749 logevent("Access denied");
6750 if (s->type == AUTH_TYPE_PASSWORD &&
6751 ssh->cfg.change_username) {
6752 /* XXX perhaps we should allow
6753 * keyboard-interactive to do this too? */
6754 s->we_are_in = FALSE;
6759 c_write_str(ssh, "Further authentication required\r\n");
6760 logevent("Further authentication required");
6764 in_commasep_string("publickey", methods, methlen);
6766 in_commasep_string("password", methods, methlen);
6767 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6768 in_commasep_string("keyboard-interactive", methods, methlen);
6772 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6776 * Most password/passphrase prompts will be
6777 * non-echoing, so we set this to 0 by default.
6778 * Exception is that some keyboard-interactive prompts
6779 * can be echoing, in which case we'll set this to 1.
6783 if (!s->method && s->can_pubkey &&
6784 agent_exists() && !s->tried_agent) {
6786 * Attempt public-key authentication using Pageant.
6791 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6792 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6794 s->tried_agent = TRUE;
6796 logevent("Pageant is running. Requesting keys.");
6798 /* Request the keys held by the agent. */
6799 PUT_32BIT(s->request, 1);
6800 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6801 if (!agent_query(s->request, 5, &r, &s->responselen,
6802 ssh_agent_callback, ssh)) {
6806 bombout(("Unexpected data from server while"
6807 " waiting for agent response"));
6810 } while (pktin || inlen > 0);
6811 r = ssh->agent_response;
6812 s->responselen = ssh->agent_response_len;
6814 s->response = (unsigned char *) r;
6815 if (s->response && s->responselen >= 5 &&
6816 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6817 s->p = s->response + 5;
6818 s->nkeys = GET_32BIT(s->p);
6820 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6821 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6824 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6825 s->pklen = GET_32BIT(s->p);
6827 if (s->publickey_blob &&
6828 s->pklen == s->publickey_bloblen &&
6829 !memcmp(s->p, s->publickey_blob,
6830 s->publickey_bloblen)) {
6831 logevent("This key matches configured key file");
6832 s->tried_pubkey_config = 1;
6834 s->pkblob = (char *)s->p;
6836 s->alglen = GET_32BIT(s->pkblob);
6837 s->alg = s->pkblob + 4;
6838 s->commentlen = GET_32BIT(s->p);
6840 s->commentp = (char *)s->p;
6841 s->p += s->commentlen;
6842 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6843 ssh2_pkt_addstring(s->pktout, s->username);
6844 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6845 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6846 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6847 ssh2_pkt_addstring_start(s->pktout);
6848 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6849 ssh2_pkt_addstring_start(s->pktout);
6850 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6851 ssh2_pkt_send(ssh, s->pktout);
6853 crWaitUntilV(pktin);
6854 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6855 logevent("Key refused");
6859 if (flags & FLAG_VERBOSE) {
6860 c_write_str(ssh, "Authenticating with "
6862 c_write(ssh, s->commentp, s->commentlen);
6863 c_write_str(ssh, "\" from agent\r\n");
6867 * Server is willing to accept the key.
6868 * Construct a SIGN_REQUEST.
6870 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6871 ssh2_pkt_addstring(s->pktout, s->username);
6872 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6873 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6874 ssh2_pkt_addbool(s->pktout, TRUE);
6875 ssh2_pkt_addstring_start(s->pktout);
6876 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6877 ssh2_pkt_addstring_start(s->pktout);
6878 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6880 s->siglen = s->pktout->length - 5 + 4 + 20;
6881 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6883 s->len = 1; /* message type */
6884 s->len += 4 + s->pklen; /* key blob */
6885 s->len += 4 + s->siglen; /* data to sign */
6886 s->len += 4; /* flags */
6887 s->agentreq = snewn(4 + s->len, char);
6888 PUT_32BIT(s->agentreq, s->len);
6889 s->q = s->agentreq + 4;
6890 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6891 PUT_32BIT(s->q, s->pklen);
6893 memcpy(s->q, s->pkblob, s->pklen);
6895 PUT_32BIT(s->q, s->siglen);
6897 /* Now the data to be signed... */
6898 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6899 PUT_32BIT(s->q, 20);
6902 memcpy(s->q, ssh->v2_session_id, 20);
6904 memcpy(s->q, s->pktout->data + 5,
6905 s->pktout->length - 5);
6906 s->q += s->pktout->length - 5;
6907 /* And finally the (zero) flags word. */
6909 if (!agent_query(s->agentreq, s->len + 4,
6911 ssh_agent_callback, ssh)) {
6915 bombout(("Unexpected data from server"
6916 " while waiting for agent"
6920 } while (pktin || inlen > 0);
6921 vret = ssh->agent_response;
6922 s->retlen = ssh->agent_response_len;
6927 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6928 logevent("Sending Pageant's response");
6929 ssh2_add_sigblob(ssh, s->pktout,
6930 s->pkblob, s->pklen,
6932 GET_32BIT(s->ret + 5));
6933 ssh2_pkt_send(ssh, s->pktout);
6938 ("Pageant failed to answer challenge");
6949 if (!s->method && s->can_pubkey && s->publickey_blob
6950 && !s->tried_pubkey_config) {
6951 unsigned char *pub_blob;
6952 char *algorithm, *comment;
6955 s->tried_pubkey_config = TRUE;
6957 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6958 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6961 * Try the public key supplied in the configuration.
6963 * First, offer the public blob to see if the server is
6964 * willing to accept it.
6967 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6972 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6973 ssh2_pkt_addstring(s->pktout, s->username);
6974 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6975 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6976 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6977 ssh2_pkt_addstring(s->pktout, algorithm);
6978 ssh2_pkt_addstring_start(s->pktout);
6979 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6981 ssh2_pkt_send(ssh, s->pktout);
6982 logevent("Offered public key");
6984 crWaitUntilV(pktin);
6985 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6987 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6988 continue; /* key refused; give up on it */
6991 logevent("Offer of public key accepted");
6993 * Actually attempt a serious authentication using
6996 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6997 sprintf(s->pwprompt,
6998 "Passphrase for key \"%.100s\": ",
7004 if (flags & FLAG_VERBOSE) {
7005 c_write_str(ssh, "Authenticating with public key \"");
7006 c_write_str(ssh, comment);
7007 c_write_str(ssh, "\"\r\n");
7009 s->method = AUTH_PUBLICKEY_FILE;
7013 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
7014 !s->kbd_inter_running) {
7015 s->method = AUTH_KEYBOARD_INTERACTIVE;
7016 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7018 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7019 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7021 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7022 ssh2_pkt_addstring(s->pktout, s->username);
7023 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7024 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
7025 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7026 ssh2_pkt_addstring(s->pktout, "");
7027 ssh2_pkt_send(ssh, s->pktout);
7029 crWaitUntilV(pktin);
7030 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7031 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7033 logevent("Keyboard-interactive authentication refused");
7034 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7035 s->kbd_inter_refused = TRUE; /* don't try it again */
7039 c_write_str(ssh, "Using keyboard-interactive authentication.\r\n");
7040 s->kbd_inter_running = TRUE;
7044 if (s->kbd_inter_running) {
7045 s->method = AUTH_KEYBOARD_INTERACTIVE;
7046 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7048 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7049 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7051 if (s->curr_prompt == 0) {
7053 * We've got a fresh USERAUTH_INFO_REQUEST.
7054 * Display header data, and start going through
7057 char *name, *inst, *lang;
7058 int name_len, inst_len, lang_len;
7060 ssh_pkt_getstring(pktin, &name, &name_len);
7061 ssh_pkt_getstring(pktin, &inst, &inst_len);
7062 ssh_pkt_getstring(pktin, &lang, &lang_len);
7064 c_write_untrusted(ssh, name, name_len);
7065 c_write_str(ssh, "\r\n");
7068 c_write_untrusted(ssh, inst, inst_len);
7069 c_write_str(ssh, "\r\n");
7071 s->num_prompts = ssh_pkt_getuint32(pktin);
7075 * If there are prompts remaining in the packet,
7076 * display one and get a response.
7078 if (s->curr_prompt < s->num_prompts) {
7082 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7083 if (prompt_len > 0) {
7084 static const char trunc[] = "<prompt truncated>: ";
7085 static const int prlen = sizeof(s->pwprompt) -
7087 if (prompt_len > prlen) {
7088 memcpy(s->pwprompt, prompt, prlen);
7089 strcpy(s->pwprompt + prlen, trunc);
7091 memcpy(s->pwprompt, prompt, prompt_len);
7092 s->pwprompt[prompt_len] = '\0';
7096 "<server failed to send prompt>: ");
7098 s->echo = ssh2_pkt_getbool(pktin);
7104 if (!s->method && s->can_passwd) {
7105 s->method = AUTH_PASSWORD;
7106 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7107 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7108 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
7115 if (!ssh_get_line(s->pwprompt, s->password,
7116 sizeof(s->password), TRUE)) {
7118 * get_line failed to get a password (for
7119 * example because one was supplied on the
7120 * command line which has already failed to
7123 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7124 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7129 int ret; /* need not be saved across crReturn */
7130 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
7133 setup_userpass_input(ssh, s->password,
7134 sizeof(s->password), s->echo);
7136 crWaitUntilV(!pktin);
7137 ret = process_userpass_input(ssh, in, inlen);
7141 c_write_str(ssh, "\r\n");
7145 if (s->method == AUTH_PUBLICKEY_FILE) {
7147 * We have our passphrase. Now try the actual authentication.
7149 struct ssh2_userkey *key;
7150 const char *error = NULL;
7152 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
7154 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7155 if (key == SSH2_WRONG_PASSPHRASE) {
7156 c_write_str(ssh, "Wrong passphrase\r\n");
7157 s->tried_pubkey_config = FALSE;
7159 c_write_str(ssh, "Unable to load private key (");
7160 c_write_str(ssh, error);
7161 c_write_str(ssh, ")\r\n");
7162 s->tried_pubkey_config = TRUE;
7164 /* Send a spurious AUTH_NONE to return to the top. */
7165 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7166 ssh2_pkt_addstring(s->pktout, s->username);
7167 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7168 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7169 ssh2_pkt_send(ssh, s->pktout);
7170 s->type = AUTH_TYPE_NONE;
7172 unsigned char *pkblob, *sigblob, *sigdata;
7173 int pkblob_len, sigblob_len, sigdata_len;
7177 * We have loaded the private key and the server
7178 * has announced that it's willing to accept it.
7179 * Hallelujah. Generate a signature and send it.
7181 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7182 ssh2_pkt_addstring(s->pktout, s->username);
7183 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7184 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7185 ssh2_pkt_addbool(s->pktout, TRUE);
7186 ssh2_pkt_addstring(s->pktout, key->alg->name);
7187 pkblob = key->alg->public_blob(key->data, &pkblob_len);
7188 ssh2_pkt_addstring_start(s->pktout);
7189 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
7192 * The data to be signed is:
7196 * followed by everything so far placed in the
7199 sigdata_len = s->pktout->length - 5 + 4 + 20;
7200 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7202 sigdata = snewn(sigdata_len, unsigned char);
7204 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7205 PUT_32BIT(sigdata+p, 20);
7208 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
7209 memcpy(sigdata+p, s->pktout->data + 5,
7210 s->pktout->length - 5);
7211 p += s->pktout->length - 5;
7212 assert(p == sigdata_len);
7213 sigblob = key->alg->sign(key->data, (char *)sigdata,
7214 sigdata_len, &sigblob_len);
7215 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7216 sigblob, sigblob_len);
7221 ssh2_pkt_send(ssh, s->pktout);
7222 s->type = AUTH_TYPE_PUBLICKEY;
7223 key->alg->freekey(key->data);
7225 } else if (s->method == AUTH_PASSWORD) {
7227 * We pad out the password packet to 256 bytes to make
7228 * it harder for an attacker to find the length of the
7231 * Anyone using a password longer than 256 bytes
7232 * probably doesn't have much to worry about from
7233 * people who find out how long their password is!
7235 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7236 s->pktout->forcepad = 256;
7237 ssh2_pkt_addstring(s->pktout, s->username);
7238 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7239 ssh2_pkt_addstring(s->pktout, "password");
7240 ssh2_pkt_addbool(s->pktout, FALSE);
7241 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7242 ssh2_pkt_addstring(s->pktout, s->password);
7243 memset(s->password, 0, sizeof(s->password));
7244 end_log_omission(ssh, s->pktout);
7245 ssh2_pkt_send(ssh, s->pktout);
7246 logevent("Sent password");
7247 s->type = AUTH_TYPE_PASSWORD;
7248 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7249 if (s->curr_prompt == 0) {
7250 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7251 s->pktout->forcepad = 256;
7252 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7254 if (s->need_pw) { /* only add pw if we just got one! */
7255 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7256 ssh2_pkt_addstring(s->pktout, s->password);
7257 memset(s->password, 0, sizeof(s->password));
7258 end_log_omission(ssh, s->pktout);
7261 if (s->curr_prompt >= s->num_prompts) {
7262 ssh2_pkt_send(ssh, s->pktout);
7265 * If there are prompts remaining, we set
7266 * `gotit' so that we won't attempt to get
7267 * another packet. Then we go back round the
7268 * loop and will end up retrieving another
7269 * prompt out of the existing packet. Funky or
7274 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7276 ssh_disconnect(ssh, NULL,
7277 "No supported authentication methods available",
7278 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7284 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7287 * Now the connection protocol has started, one way or another.
7290 ssh->channels = newtree234(ssh_channelcmp);
7293 * Set up handlers for some connection protocol messages, so we
7294 * don't have to handle them repeatedly in this coroutine.
7296 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7297 ssh2_msg_channel_window_adjust;
7298 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7299 ssh2_msg_global_request;
7302 * Create the main session channel.
7304 if (!ssh->cfg.ssh_no_shell) {
7305 ssh->mainchan = snew(struct ssh_channel);
7306 ssh->mainchan->ssh = ssh;
7307 ssh->mainchan->localid = alloc_channel_id(ssh);
7308 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7309 ssh2_pkt_addstring(s->pktout, "session");
7310 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7311 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7312 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7313 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7314 ssh2_pkt_send(ssh, s->pktout);
7315 crWaitUntilV(pktin);
7316 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7317 bombout(("Server refused to open a session"));
7319 /* FIXME: error data comes back in FAILURE packet */
7321 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7322 bombout(("Server's channel confirmation cited wrong channel"));
7325 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7326 ssh->mainchan->halfopen = FALSE;
7327 ssh->mainchan->type = CHAN_MAINSESSION;
7328 ssh->mainchan->closes = 0;
7329 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7330 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7331 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7332 add234(ssh->channels, ssh->mainchan);
7333 update_specials_menu(ssh->frontend);
7334 logevent("Opened channel for session");
7336 ssh->mainchan = NULL;
7339 * Now we have a channel, make dispatch table entries for
7340 * general channel-based messages.
7342 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7343 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7344 ssh2_msg_channel_data;
7345 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7346 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7347 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7348 ssh2_msg_channel_open_confirmation;
7349 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7350 ssh2_msg_channel_open_failure;
7351 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7352 ssh2_msg_channel_request;
7353 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7354 ssh2_msg_channel_open;
7357 * Potentially enable X11 forwarding.
7359 if (ssh->mainchan && ssh->cfg.x11_forward) {
7360 char proto[20], data[64];
7361 logevent("Requesting X11 forwarding");
7362 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7363 data, sizeof(data), ssh->cfg.x11_auth);
7364 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7365 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7366 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7367 ssh2_pkt_addstring(s->pktout, "x11-req");
7368 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7369 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7370 ssh2_pkt_addstring(s->pktout, proto);
7372 * Note that while we blank the X authentication data here, we don't
7373 * take any special action to blank the start of an X11 channel,
7374 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7375 * without having session blanking enabled is likely to leak your
7376 * cookie into the log.
7378 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7379 ssh2_pkt_addstring(s->pktout, data);
7380 end_log_omission(ssh, s->pktout);
7381 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7382 ssh2_pkt_send(ssh, s->pktout);
7384 crWaitUntilV(pktin);
7386 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7387 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7388 bombout(("Unexpected response to X11 forwarding request:"
7389 " packet type %d", pktin->type));
7392 logevent("X11 forwarding refused");
7394 logevent("X11 forwarding enabled");
7395 ssh->X11_fwd_enabled = TRUE;
7400 * Enable port forwardings.
7402 ssh_setup_portfwd(ssh, &ssh->cfg);
7405 * Potentially enable agent forwarding.
7407 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7408 logevent("Requesting OpenSSH-style agent forwarding");
7409 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7410 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7411 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7412 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7413 ssh2_pkt_send(ssh, s->pktout);
7415 crWaitUntilV(pktin);
7417 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7418 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7419 bombout(("Unexpected response to agent forwarding request:"
7420 " packet type %d", pktin->type));
7423 logevent("Agent forwarding refused");
7425 logevent("Agent forwarding enabled");
7426 ssh->agentfwd_enabled = TRUE;
7431 * Now allocate a pty for the session.
7433 if (ssh->mainchan && !ssh->cfg.nopty) {
7434 /* Unpick the terminal-speed string. */
7435 /* XXX perhaps we should allow no speeds to be sent. */
7436 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7437 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7438 /* Build the pty request. */
7439 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7440 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7441 ssh2_pkt_addstring(s->pktout, "pty-req");
7442 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7443 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7444 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7445 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7446 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7447 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7448 ssh2_pkt_addstring_start(s->pktout);
7449 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7450 ssh2_send_ttymode, (void *)s->pktout);
7451 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
7452 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7453 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
7454 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7455 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7456 ssh2_pkt_send(ssh, s->pktout);
7457 ssh->state = SSH_STATE_INTERMED;
7459 crWaitUntilV(pktin);
7461 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7462 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7463 bombout(("Unexpected response to pty request:"
7464 " packet type %d", pktin->type));
7467 c_write_str(ssh, "Server refused to allocate pty\r\n");
7468 ssh->editing = ssh->echoing = 1;
7470 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7471 ssh->ospeed, ssh->ispeed);
7474 ssh->editing = ssh->echoing = 1;
7478 * Send environment variables.
7480 * Simplest thing here is to send all the requests at once, and
7481 * then wait for a whole bunch of successes or failures.
7483 if (ssh->mainchan && *ssh->cfg.environmt) {
7484 char *e = ssh->cfg.environmt;
7485 char *var, *varend, *val;
7491 while (*e && *e != '\t') e++;
7493 if (*e == '\t') e++;
7498 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7499 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7500 ssh2_pkt_addstring(s->pktout, "env");
7501 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7502 ssh2_pkt_addstring_start(s->pktout);
7503 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7504 ssh2_pkt_addstring(s->pktout, val);
7505 ssh2_pkt_send(ssh, s->pktout);
7510 logeventf(ssh, "Sent %d environment variables", s->num_env);
7513 s->env_left = s->num_env;
7515 while (s->env_left > 0) {
7516 crWaitUntilV(pktin);
7518 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7519 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7520 bombout(("Unexpected response to environment request:"
7521 " packet type %d", pktin->type));
7531 if (s->env_ok == s->num_env) {
7532 logevent("All environment variables successfully set");
7533 } else if (s->env_ok == 0) {
7534 logevent("All environment variables refused");
7535 c_write_str(ssh, "Server refused to set environment variables\r\n");
7537 logeventf(ssh, "%d environment variables refused",
7538 s->num_env - s->env_ok);
7539 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7544 * Start a shell or a remote command. We may have to attempt
7545 * this twice if the config data has provided a second choice
7548 if (ssh->mainchan) while (1) {
7552 if (ssh->fallback_cmd) {
7553 subsys = ssh->cfg.ssh_subsys2;
7554 cmd = ssh->cfg.remote_cmd_ptr2;
7556 subsys = ssh->cfg.ssh_subsys;
7557 cmd = ssh->cfg.remote_cmd_ptr;
7558 if (!cmd) cmd = ssh->cfg.remote_cmd;
7561 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7562 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7564 ssh2_pkt_addstring(s->pktout, "subsystem");
7565 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7566 ssh2_pkt_addstring(s->pktout, cmd);
7568 ssh2_pkt_addstring(s->pktout, "exec");
7569 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7570 ssh2_pkt_addstring(s->pktout, cmd);
7572 ssh2_pkt_addstring(s->pktout, "shell");
7573 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7575 ssh2_pkt_send(ssh, s->pktout);
7577 crWaitUntilV(pktin);
7579 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7580 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7581 bombout(("Unexpected response to shell/command request:"
7582 " packet type %d", pktin->type));
7586 * We failed to start the command. If this is the
7587 * fallback command, we really are finished; if it's
7588 * not, and if the fallback command exists, try falling
7589 * back to it before complaining.
7591 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7592 logevent("Primary command failed; attempting fallback");
7593 ssh->fallback_cmd = TRUE;
7596 bombout(("Server refused to start a shell/command"));
7599 logevent("Started a shell/command");
7604 ssh->state = SSH_STATE_SESSION;
7605 if (ssh->size_needed)
7606 ssh_size(ssh, ssh->term_width, ssh->term_height);
7607 if (ssh->eof_needed)
7608 ssh_special(ssh, TS_EOF);
7614 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7619 s->try_send = FALSE;
7623 * _All_ the connection-layer packets we expect to
7624 * receive are now handled by the dispatch table.
7625 * Anything that reaches here must be bogus.
7628 bombout(("Strange packet received: type %d", pktin->type));
7630 } else if (ssh->mainchan) {
7632 * We have spare data. Add it to the channel buffer.
7634 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7639 struct ssh_channel *c;
7641 * Try to send data on all channels if we can.
7643 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7644 ssh2_try_send_and_unthrottle(c);
7652 * Handlers for SSH-2 messages that might arrive at any moment.
7654 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7656 /* log reason code in disconnect message */
7658 int nowlen, reason, msglen;
7660 reason = ssh_pkt_getuint32(pktin);
7661 ssh_pkt_getstring(pktin, &msg, &msglen);
7663 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7664 buf = dupprintf("Received disconnect message (%s)",
7665 ssh2_disconnect_reasons[reason]);
7667 buf = dupprintf("Received disconnect message (unknown"
7668 " type %d)", reason);
7672 buf = dupprintf("Disconnection message text: %n%.*s",
7673 &nowlen, msglen, msg);
7675 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7677 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7678 ssh2_disconnect_reasons[reason] : "unknown",
7683 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7685 /* log the debug message */
7690 /* XXX maybe we should actually take notice of this */
7691 always_display = ssh2_pkt_getbool(pktin);
7692 ssh_pkt_getstring(pktin, &msg, &msglen);
7694 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7697 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7699 struct Packet *pktout;
7700 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7701 ssh2_pkt_adduint32(pktout, pktin->sequence);
7703 * UNIMPLEMENTED messages MUST appear in the same order as the
7704 * messages they respond to. Hence, never queue them.
7706 ssh2_pkt_send_noqueue(ssh, pktout);
7710 * Handle the top-level SSH-2 protocol.
7712 static void ssh2_protocol_setup(Ssh ssh)
7717 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7719 for (i = 0; i < 256; i++)
7720 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7723 * Any message we actually understand, we set to NULL so that
7724 * the coroutines will get it.
7726 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7727 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7728 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7729 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7730 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7731 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7732 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7733 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7734 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7735 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7736 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7737 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7738 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7739 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7740 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7741 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7742 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7743 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7744 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7745 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7746 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7747 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7748 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7749 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7750 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7751 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7752 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7753 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7754 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7755 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7756 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7757 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7758 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7761 * These special message types we install handlers for.
7763 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7764 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
7765 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7768 static void ssh2_timer(void *ctx, long now)
7772 if (ssh->state == SSH_STATE_CLOSED)
7775 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7776 now - ssh->next_rekey >= 0) {
7777 do_ssh2_transport(ssh, "timeout", -1, NULL);
7781 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7782 struct Packet *pktin)
7784 unsigned char *in = (unsigned char *)vin;
7785 if (ssh->state == SSH_STATE_CLOSED)
7789 ssh->incoming_data_size += pktin->encrypted_len;
7790 if (!ssh->kex_in_progress &&
7791 ssh->max_data_size != 0 &&
7792 ssh->incoming_data_size > ssh->max_data_size)
7793 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7796 if (pktin && ssh->packet_dispatch[pktin->type]) {
7797 ssh->packet_dispatch[pktin->type](ssh, pktin);
7801 if (!ssh->protocol_initial_phase_done ||
7802 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7803 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7804 !ssh->protocol_initial_phase_done) {
7805 ssh->protocol_initial_phase_done = TRUE;
7807 * Allow authconn to initialise itself.
7809 do_ssh2_authconn(ssh, NULL, 0, NULL);
7812 do_ssh2_authconn(ssh, in, inlen, pktin);
7817 * Called to set up the connection.
7819 * Returns an error message, or NULL on success.
7821 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7823 char *host, int port, char **realhost, int nodelay,
7829 ssh = snew(struct ssh_tag);
7830 ssh->cfg = *cfg; /* STRUCTURE COPY */
7831 ssh->version = 0; /* when not ready yet */
7834 ssh->v1_cipher_ctx = NULL;
7835 ssh->crcda_ctx = NULL;
7836 ssh->cscipher = NULL;
7837 ssh->cs_cipher_ctx = NULL;
7838 ssh->sccipher = NULL;
7839 ssh->sc_cipher_ctx = NULL;
7841 ssh->cs_mac_ctx = NULL;
7843 ssh->sc_mac_ctx = NULL;
7845 ssh->cs_comp_ctx = NULL;
7847 ssh->sc_comp_ctx = NULL;
7849 ssh->kex_ctx = NULL;
7850 ssh->hostkey = NULL;
7852 ssh->close_expected = FALSE;
7853 ssh->clean_exit = FALSE;
7854 ssh->state = SSH_STATE_PREPACKET;
7855 ssh->size_needed = FALSE;
7856 ssh->eof_needed = FALSE;
7859 ssh->deferred_send_data = NULL;
7860 ssh->deferred_len = 0;
7861 ssh->deferred_size = 0;
7862 ssh->fallback_cmd = 0;
7864 ssh->x11auth = NULL;
7865 ssh->v1_compressing = FALSE;
7866 ssh->v2_outgoing_sequence = 0;
7867 ssh->ssh1_rdpkt_crstate = 0;
7868 ssh->ssh2_rdpkt_crstate = 0;
7869 ssh->do_ssh_init_crstate = 0;
7870 ssh->ssh_gotdata_crstate = 0;
7871 ssh->do_ssh1_connection_crstate = 0;
7872 ssh->do_ssh1_login_crstate = 0;
7873 ssh->do_ssh2_transport_crstate = 0;
7874 ssh->do_ssh2_authconn_crstate = 0;
7875 ssh->do_ssh_init_state = NULL;
7876 ssh->do_ssh1_login_state = NULL;
7877 ssh->do_ssh2_transport_state = NULL;
7878 ssh->do_ssh2_authconn_state = NULL;
7881 ssh->mainchan = NULL;
7882 ssh->throttled_all = 0;
7883 ssh->v1_stdout_throttling = 0;
7885 ssh->queuelen = ssh->queuesize = 0;
7886 ssh->queueing = FALSE;
7887 ssh->qhead = ssh->qtail = NULL;
7888 ssh->deferred_rekey_reason = NULL;
7889 bufchain_init(&ssh->queued_incoming_data);
7890 ssh->frozen = FALSE;
7892 *backend_handle = ssh;
7895 if (crypto_startup() == 0)
7896 return "Microsoft high encryption pack not installed!";
7899 ssh->frontend = frontend_handle;
7900 ssh->term_width = ssh->cfg.width;
7901 ssh->term_height = ssh->cfg.height;
7903 ssh->channels = NULL;
7904 ssh->rportfwds = NULL;
7905 ssh->portfwds = NULL;
7910 ssh->v1_throttle_count = 0;
7911 ssh->overall_bufsize = 0;
7912 ssh->fallback_cmd = 0;
7914 ssh->protocol = NULL;
7916 ssh->protocol_initial_phase_done = FALSE;
7920 ssh->incoming_data_size = ssh->outgoing_data_size =
7921 ssh->deferred_data_size = 0L;
7922 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7923 ssh->kex_in_progress = FALSE;
7925 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7934 static void ssh_free(void *handle)
7936 Ssh ssh = (Ssh) handle;
7937 struct ssh_channel *c;
7938 struct ssh_rportfwd *pf;
7940 if (ssh->v1_cipher_ctx)
7941 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7942 if (ssh->cs_cipher_ctx)
7943 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7944 if (ssh->sc_cipher_ctx)
7945 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7946 if (ssh->cs_mac_ctx)
7947 ssh->csmac->free_context(ssh->cs_mac_ctx);
7948 if (ssh->sc_mac_ctx)
7949 ssh->scmac->free_context(ssh->sc_mac_ctx);
7950 if (ssh->cs_comp_ctx) {
7952 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7954 zlib_compress_cleanup(ssh->cs_comp_ctx);
7956 if (ssh->sc_comp_ctx) {
7958 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7960 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7963 dh_cleanup(ssh->kex_ctx);
7964 sfree(ssh->savedhost);
7966 while (ssh->queuelen-- > 0)
7967 ssh_free_packet(ssh->queue[ssh->queuelen]);
7970 while (ssh->qhead) {
7971 struct queued_handler *qh = ssh->qhead;
7972 ssh->qhead = qh->next;
7975 ssh->qhead = ssh->qtail = NULL;
7977 if (ssh->channels) {
7978 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7981 if (c->u.x11.s != NULL)
7982 x11_close(c->u.x11.s);
7985 if (c->u.pfd.s != NULL)
7986 pfd_close(c->u.pfd.s);
7991 freetree234(ssh->channels);
7992 ssh->channels = NULL;
7995 if (ssh->rportfwds) {
7996 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7998 freetree234(ssh->rportfwds);
7999 ssh->rportfwds = NULL;
8001 sfree(ssh->deferred_send_data);
8003 x11_free_auth(ssh->x11auth);
8004 sfree(ssh->do_ssh_init_state);
8005 sfree(ssh->do_ssh1_login_state);
8006 sfree(ssh->do_ssh2_transport_state);
8007 sfree(ssh->do_ssh2_authconn_state);
8010 if (ssh->crcda_ctx) {
8011 crcda_free_context(ssh->crcda_ctx);
8012 ssh->crcda_ctx = NULL;
8015 ssh_do_close(ssh, TRUE);
8016 expire_timer_context(ssh);
8018 pinger_free(ssh->pinger);
8019 bufchain_clear(&ssh->queued_incoming_data);
8026 * Reconfigure the SSH backend.
8028 static void ssh_reconfig(void *handle, Config *cfg)
8030 Ssh ssh = (Ssh) handle;
8031 char *rekeying = NULL, rekey_mandatory = FALSE;
8032 unsigned long old_max_data_size;
8034 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8036 ssh_setup_portfwd(ssh, cfg);
8038 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8039 cfg->ssh_rekey_time != 0) {
8040 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8041 long now = GETTICKCOUNT();
8043 if (new_next - now < 0) {
8044 rekeying = "timeout shortened";
8046 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8050 old_max_data_size = ssh->max_data_size;
8051 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8052 if (old_max_data_size != ssh->max_data_size &&
8053 ssh->max_data_size != 0) {
8054 if (ssh->outgoing_data_size > ssh->max_data_size ||
8055 ssh->incoming_data_size > ssh->max_data_size)
8056 rekeying = "data limit lowered";
8059 if (ssh->cfg.compression != cfg->compression) {
8060 rekeying = "compression setting changed";
8061 rekey_mandatory = TRUE;
8064 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8065 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8066 sizeof(ssh->cfg.ssh_cipherlist))) {
8067 rekeying = "cipher settings changed";
8068 rekey_mandatory = TRUE;
8071 ssh->cfg = *cfg; /* STRUCTURE COPY */
8074 if (!ssh->kex_in_progress) {
8075 do_ssh2_transport(ssh, rekeying, -1, NULL);
8076 } else if (rekey_mandatory) {
8077 ssh->deferred_rekey_reason = rekeying;
8083 * Called to send data down the SSH connection.
8085 static int ssh_send(void *handle, char *buf, int len)
8087 Ssh ssh = (Ssh) handle;
8089 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8092 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8094 return ssh_sendbuffer(ssh);
8098 * Called to query the current amount of buffered stdin data.
8100 static int ssh_sendbuffer(void *handle)
8102 Ssh ssh = (Ssh) handle;
8105 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8109 * If the SSH socket itself has backed up, add the total backup
8110 * size on that to any individual buffer on the stdin channel.
8113 if (ssh->throttled_all)
8114 override_value = ssh->overall_bufsize;
8116 if (ssh->version == 1) {
8117 return override_value;
8118 } else if (ssh->version == 2) {
8119 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8120 return override_value;
8122 return (override_value +
8123 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8130 * Called to set the size of the window from SSH's POV.
8132 static void ssh_size(void *handle, int width, int height)
8134 Ssh ssh = (Ssh) handle;
8135 struct Packet *pktout;
8137 ssh->term_width = width;
8138 ssh->term_height = height;
8140 switch (ssh->state) {
8141 case SSH_STATE_BEFORE_SIZE:
8142 case SSH_STATE_PREPACKET:
8143 case SSH_STATE_CLOSED:
8144 break; /* do nothing */
8145 case SSH_STATE_INTERMED:
8146 ssh->size_needed = TRUE; /* buffer for later */
8148 case SSH_STATE_SESSION:
8149 if (!ssh->cfg.nopty) {
8150 if (ssh->version == 1) {
8151 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8152 PKT_INT, ssh->term_height,
8153 PKT_INT, ssh->term_width,
8154 PKT_INT, 0, PKT_INT, 0, PKT_END);
8155 } else if (ssh->mainchan) {
8156 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8157 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8158 ssh2_pkt_addstring(pktout, "window-change");
8159 ssh2_pkt_addbool(pktout, 0);
8160 ssh2_pkt_adduint32(pktout, ssh->term_width);
8161 ssh2_pkt_adduint32(pktout, ssh->term_height);
8162 ssh2_pkt_adduint32(pktout, 0);
8163 ssh2_pkt_adduint32(pktout, 0);
8164 ssh2_pkt_send(ssh, pktout);
8172 * Return a list of the special codes that make sense in this
8175 static const struct telnet_special *ssh_get_specials(void *handle)
8177 static const struct telnet_special ssh1_ignore_special[] = {
8178 {"IGNORE message", TS_NOP}
8180 static const struct telnet_special ssh2_transport_specials[] = {
8181 {"IGNORE message", TS_NOP},
8182 {"Repeat key exchange", TS_REKEY},
8184 static const struct telnet_special ssh2_session_specials[] = {
8187 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8188 * They include all the ISO C signals, but are a subset of the POSIX
8189 * required signals. */
8190 {"SIGINT (Interrupt)", TS_SIGINT},
8191 {"SIGTERM (Terminate)", TS_SIGTERM},
8192 {"SIGKILL (Kill)", TS_SIGKILL},
8193 {"SIGQUIT (Quit)", TS_SIGQUIT},
8194 {"SIGHUP (Hangup)", TS_SIGHUP},
8195 {"More signals", TS_SUBMENU},
8196 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8197 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8198 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8199 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8202 static const struct telnet_special specials_end[] = {
8205 /* XXX review this length for any changes: */
8206 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8207 lenof(ssh2_session_specials) +
8208 lenof(specials_end)];
8209 Ssh ssh = (Ssh) handle;
8211 #define ADD_SPECIALS(name) \
8213 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8214 memcpy(&ssh_specials[i], name, sizeof name); \
8218 if (ssh->version == 1) {
8219 /* Don't bother offering IGNORE if we've decided the remote
8220 * won't cope with it, since we wouldn't bother sending it if
8222 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8223 ADD_SPECIALS(ssh1_ignore_special);
8224 } else if (ssh->version == 2) {
8225 ADD_SPECIALS(ssh2_transport_specials);
8227 ADD_SPECIALS(ssh2_session_specials);
8228 } /* else we're not ready yet */
8231 ADD_SPECIALS(specials_end);
8232 return ssh_specials;
8240 * Send special codes. TS_EOF is useful for `plink', so you
8241 * can send an EOF and collect resulting output (e.g. `plink
8244 static void ssh_special(void *handle, Telnet_Special code)
8246 Ssh ssh = (Ssh) handle;
8247 struct Packet *pktout;
8249 if (code == TS_EOF) {
8250 if (ssh->state != SSH_STATE_SESSION) {
8252 * Buffer the EOF in case we are pre-SESSION, so we can
8253 * send it as soon as we reach SESSION.
8256 ssh->eof_needed = TRUE;
8259 if (ssh->version == 1) {
8260 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8261 } else if (ssh->mainchan) {
8262 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8263 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8264 ssh2_pkt_send(ssh, pktout);
8265 ssh->send_ok = 0; /* now stop trying to read from stdin */
8267 logevent("Sent EOF message");
8268 } else if (code == TS_PING || code == TS_NOP) {
8269 if (ssh->state == SSH_STATE_CLOSED
8270 || ssh->state == SSH_STATE_PREPACKET) return;
8271 if (ssh->version == 1) {
8272 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8273 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8275 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8276 ssh2_pkt_addstring_start(pktout);
8277 ssh2_pkt_send_noqueue(ssh, pktout);
8279 } else if (code == TS_REKEY) {
8280 if (!ssh->kex_in_progress && ssh->version == 2) {
8281 do_ssh2_transport(ssh, "at user request", -1, NULL);
8283 } else if (code == TS_BRK) {
8284 if (ssh->state == SSH_STATE_CLOSED
8285 || ssh->state == SSH_STATE_PREPACKET) return;
8286 if (ssh->version == 1) {
8287 logevent("Unable to send BREAK signal in SSH-1");
8288 } else if (ssh->mainchan) {
8289 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8290 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8291 ssh2_pkt_addstring(pktout, "break");
8292 ssh2_pkt_addbool(pktout, 0);
8293 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8294 ssh2_pkt_send(ssh, pktout);
8297 /* Is is a POSIX signal? */
8298 char *signame = NULL;
8299 if (code == TS_SIGABRT) signame = "ABRT";
8300 if (code == TS_SIGALRM) signame = "ALRM";
8301 if (code == TS_SIGFPE) signame = "FPE";
8302 if (code == TS_SIGHUP) signame = "HUP";
8303 if (code == TS_SIGILL) signame = "ILL";
8304 if (code == TS_SIGINT) signame = "INT";
8305 if (code == TS_SIGKILL) signame = "KILL";
8306 if (code == TS_SIGPIPE) signame = "PIPE";
8307 if (code == TS_SIGQUIT) signame = "QUIT";
8308 if (code == TS_SIGSEGV) signame = "SEGV";
8309 if (code == TS_SIGTERM) signame = "TERM";
8310 if (code == TS_SIGUSR1) signame = "USR1";
8311 if (code == TS_SIGUSR2) signame = "USR2";
8312 /* The SSH-2 protocol does in principle support arbitrary named
8313 * signals, including signame@domain, but we don't support those. */
8315 /* It's a signal. */
8316 if (ssh->version == 2 && ssh->mainchan) {
8317 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8318 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8319 ssh2_pkt_addstring(pktout, "signal");
8320 ssh2_pkt_addbool(pktout, 0);
8321 ssh2_pkt_addstring(pktout, signame);
8322 ssh2_pkt_send(ssh, pktout);
8323 logeventf(ssh, "Sent signal SIG%s", signame);
8326 /* Never heard of it. Do nothing */
8331 void *new_sock_channel(void *handle, Socket s)
8333 Ssh ssh = (Ssh) handle;
8334 struct ssh_channel *c;
8335 c = snew(struct ssh_channel);
8340 c->localid = alloc_channel_id(ssh);
8342 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8344 bufchain_init(&c->v.v2.outbuffer);
8345 add234(ssh->channels, c);
8351 * This is called when stdout/stderr (the entity to which
8352 * from_backend sends data) manages to clear some backlog.
8354 static void ssh_unthrottle(void *handle, int bufsize)
8356 Ssh ssh = (Ssh) handle;
8357 if (ssh->version == 1) {
8358 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8359 ssh->v1_stdout_throttling = 0;
8360 ssh1_throttle(ssh, -1);
8363 if (ssh->mainchan && ssh->mainchan->closes == 0)
8364 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8368 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8370 struct ssh_channel *c = (struct ssh_channel *)channel;
8372 struct Packet *pktout;
8374 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8376 if (ssh->version == 1) {
8377 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8378 PKT_INT, c->localid,
8381 /* PKT_STR, <org:orgport>, */
8384 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8385 ssh2_pkt_addstring(pktout, "direct-tcpip");
8386 ssh2_pkt_adduint32(pktout, c->localid);
8387 c->v.v2.locwindow = OUR_V2_WINSIZE;
8388 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8389 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8390 ssh2_pkt_addstring(pktout, hostname);
8391 ssh2_pkt_adduint32(pktout, port);
8393 * We make up values for the originator data; partly it's
8394 * too much hassle to keep track, and partly I'm not
8395 * convinced the server should be told details like that
8396 * about my local network configuration.
8398 ssh2_pkt_addstring(pktout, "client-side-connection");
8399 ssh2_pkt_adduint32(pktout, 0);
8400 ssh2_pkt_send(ssh, pktout);
8404 static Socket ssh_socket(void *handle)
8406 Ssh ssh = (Ssh) handle;
8410 static int ssh_sendok(void *handle)
8412 Ssh ssh = (Ssh) handle;
8413 return ssh->send_ok;
8416 static int ssh_ldisc(void *handle, int option)
8418 Ssh ssh = (Ssh) handle;
8419 if (option == LD_ECHO)
8420 return ssh->echoing;
8421 if (option == LD_EDIT)
8422 return ssh->editing;
8426 static void ssh_provide_ldisc(void *handle, void *ldisc)
8428 Ssh ssh = (Ssh) handle;
8432 static void ssh_provide_logctx(void *handle, void *logctx)
8434 Ssh ssh = (Ssh) handle;
8435 ssh->logctx = logctx;
8438 static int ssh_return_exitcode(void *handle)
8440 Ssh ssh = (Ssh) handle;
8444 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8448 * cfg_info for SSH is the currently running version of the
8449 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8451 static int ssh_cfg_info(void *handle)
8453 Ssh ssh = (Ssh) handle;
8454 return ssh->version;
8458 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8459 * that fails. This variable is the means by which scp.c can reach
8460 * into the SSH code and find out which one it got.
8462 extern int ssh_fallback_cmd(void *handle)
8464 Ssh ssh = (Ssh) handle;
8465 return ssh->fallback_cmd;
8468 Backend ssh_backend = {
8478 ssh_return_exitcode,