17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_KEX_MASK 0x000F
110 #define SSH2_PKTCTX_PUBLICKEY 0x0010
111 #define SSH2_PKTCTX_PASSWORD 0x0020
112 #define SSH2_PKTCTX_KBDINTER 0x0040
113 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_REKEY 64
167 #define BUG_SSH2_PK_SESSIONID 128
170 * Codes for terminal modes.
171 * Most of these are the same in SSH-1 and SSH-2.
172 * This list is derived from draft-ietf-secsh-connect-25 and
175 static const struct {
176 const char* const mode;
178 enum { TTY_OP_CHAR, TTY_OP_BOOL } type;
180 /* "V" prefix discarded for special characters relative to SSH specs */
181 { "INTR", 1, TTY_OP_CHAR },
182 { "QUIT", 2, TTY_OP_CHAR },
183 { "ERASE", 3, TTY_OP_CHAR },
184 { "KILL", 4, TTY_OP_CHAR },
185 { "EOF", 5, TTY_OP_CHAR },
186 { "EOL", 6, TTY_OP_CHAR },
187 { "EOL2", 7, TTY_OP_CHAR },
188 { "START", 8, TTY_OP_CHAR },
189 { "STOP", 9, TTY_OP_CHAR },
190 { "SUSP", 10, TTY_OP_CHAR },
191 { "DSUSP", 11, TTY_OP_CHAR },
192 { "REPRINT", 12, TTY_OP_CHAR },
193 { "WERASE", 13, TTY_OP_CHAR },
194 { "LNEXT", 14, TTY_OP_CHAR },
195 { "FLUSH", 15, TTY_OP_CHAR },
196 { "SWTCH", 16, TTY_OP_CHAR },
197 { "STATUS", 17, TTY_OP_CHAR },
198 { "DISCARD", 18, TTY_OP_CHAR },
199 { "IGNPAR", 30, TTY_OP_BOOL },
200 { "PARMRK", 31, TTY_OP_BOOL },
201 { "INPCK", 32, TTY_OP_BOOL },
202 { "ISTRIP", 33, TTY_OP_BOOL },
203 { "INLCR", 34, TTY_OP_BOOL },
204 { "IGNCR", 35, TTY_OP_BOOL },
205 { "ICRNL", 36, TTY_OP_BOOL },
206 { "IUCLC", 37, TTY_OP_BOOL },
207 { "IXON", 38, TTY_OP_BOOL },
208 { "IXANY", 39, TTY_OP_BOOL },
209 { "IXOFF", 40, TTY_OP_BOOL },
210 { "IMAXBEL", 41, TTY_OP_BOOL },
211 { "ISIG", 50, TTY_OP_BOOL },
212 { "ICANON", 51, TTY_OP_BOOL },
213 { "XCASE", 52, TTY_OP_BOOL },
214 { "ECHO", 53, TTY_OP_BOOL },
215 { "ECHOE", 54, TTY_OP_BOOL },
216 { "ECHOK", 55, TTY_OP_BOOL },
217 { "ECHONL", 56, TTY_OP_BOOL },
218 { "NOFLSH", 57, TTY_OP_BOOL },
219 { "TOSTOP", 58, TTY_OP_BOOL },
220 { "IEXTEN", 59, TTY_OP_BOOL },
221 { "ECHOCTL", 60, TTY_OP_BOOL },
222 { "ECHOKE", 61, TTY_OP_BOOL },
223 { "PENDIN", 62, TTY_OP_BOOL }, /* XXX is this a real mode? */
224 { "OPOST", 70, TTY_OP_BOOL },
225 { "OLCUC", 71, TTY_OP_BOOL },
226 { "ONLCR", 72, TTY_OP_BOOL },
227 { "OCRNL", 73, TTY_OP_BOOL },
228 { "ONOCR", 74, TTY_OP_BOOL },
229 { "ONLRET", 75, TTY_OP_BOOL },
230 { "CS7", 90, TTY_OP_BOOL },
231 { "CS8", 91, TTY_OP_BOOL },
232 { "PARENB", 92, TTY_OP_BOOL },
233 { "PARODD", 93, TTY_OP_BOOL }
236 /* Miscellaneous other tty-related constants. */
237 #define SSH_TTY_OP_END 0
238 /* The opcodes for ISPEED/OSPEED differ between SSH-1 and SSH-2. */
239 #define SSH1_TTY_OP_ISPEED 192
240 #define SSH1_TTY_OP_OSPEED 193
241 #define SSH2_TTY_OP_ISPEED 128
242 #define SSH2_TTY_OP_OSPEED 129
244 /* Helper functions for parsing tty-related config. */
245 static unsigned int ssh_tty_parse_specchar(char *s)
250 ret = ctrlparse(s, &next);
251 if (!next) ret = s[0];
253 ret = 255; /* special value meaning "don't set" */
257 static unsigned int ssh_tty_parse_boolean(char *s)
259 if (stricmp(s, "yes") == 0 ||
260 stricmp(s, "on") == 0 ||
261 stricmp(s, "true") == 0 ||
262 stricmp(s, "+") == 0)
264 else if (stricmp(s, "no") == 0 ||
265 stricmp(s, "off") == 0 ||
266 stricmp(s, "false") == 0 ||
267 stricmp(s, "-") == 0)
268 return 0; /* false */
270 return (atoi(s) != 0);
273 #define translate(x) if (type == x) return #x
274 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
275 static char *ssh1_pkt_type(int type)
277 translate(SSH1_MSG_DISCONNECT);
278 translate(SSH1_SMSG_PUBLIC_KEY);
279 translate(SSH1_CMSG_SESSION_KEY);
280 translate(SSH1_CMSG_USER);
281 translate(SSH1_CMSG_AUTH_RSA);
282 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
283 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
284 translate(SSH1_CMSG_AUTH_PASSWORD);
285 translate(SSH1_CMSG_REQUEST_PTY);
286 translate(SSH1_CMSG_WINDOW_SIZE);
287 translate(SSH1_CMSG_EXEC_SHELL);
288 translate(SSH1_CMSG_EXEC_CMD);
289 translate(SSH1_SMSG_SUCCESS);
290 translate(SSH1_SMSG_FAILURE);
291 translate(SSH1_CMSG_STDIN_DATA);
292 translate(SSH1_SMSG_STDOUT_DATA);
293 translate(SSH1_SMSG_STDERR_DATA);
294 translate(SSH1_CMSG_EOF);
295 translate(SSH1_SMSG_EXIT_STATUS);
296 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
297 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
298 translate(SSH1_MSG_CHANNEL_DATA);
299 translate(SSH1_MSG_CHANNEL_CLOSE);
300 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
301 translate(SSH1_SMSG_X11_OPEN);
302 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
303 translate(SSH1_MSG_PORT_OPEN);
304 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
305 translate(SSH1_SMSG_AGENT_OPEN);
306 translate(SSH1_MSG_IGNORE);
307 translate(SSH1_CMSG_EXIT_CONFIRMATION);
308 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
309 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
310 translate(SSH1_MSG_DEBUG);
311 translate(SSH1_CMSG_REQUEST_COMPRESSION);
312 translate(SSH1_CMSG_AUTH_TIS);
313 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
314 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
315 translate(SSH1_CMSG_AUTH_CCARD);
316 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
317 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
320 static char *ssh2_pkt_type(int pkt_ctx, int type)
322 translate(SSH2_MSG_DISCONNECT);
323 translate(SSH2_MSG_IGNORE);
324 translate(SSH2_MSG_UNIMPLEMENTED);
325 translate(SSH2_MSG_DEBUG);
326 translate(SSH2_MSG_SERVICE_REQUEST);
327 translate(SSH2_MSG_SERVICE_ACCEPT);
328 translate(SSH2_MSG_KEXINIT);
329 translate(SSH2_MSG_NEWKEYS);
330 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
331 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
332 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
333 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
334 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
335 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
336 translate(SSH2_MSG_USERAUTH_REQUEST);
337 translate(SSH2_MSG_USERAUTH_FAILURE);
338 translate(SSH2_MSG_USERAUTH_SUCCESS);
339 translate(SSH2_MSG_USERAUTH_BANNER);
340 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
341 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
342 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
343 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
344 translate(SSH2_MSG_GLOBAL_REQUEST);
345 translate(SSH2_MSG_REQUEST_SUCCESS);
346 translate(SSH2_MSG_REQUEST_FAILURE);
347 translate(SSH2_MSG_CHANNEL_OPEN);
348 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
349 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
350 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
351 translate(SSH2_MSG_CHANNEL_DATA);
352 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
353 translate(SSH2_MSG_CHANNEL_EOF);
354 translate(SSH2_MSG_CHANNEL_CLOSE);
355 translate(SSH2_MSG_CHANNEL_REQUEST);
356 translate(SSH2_MSG_CHANNEL_SUCCESS);
357 translate(SSH2_MSG_CHANNEL_FAILURE);
363 /* Enumeration values for fields in SSH-1 packets */
365 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
366 /* These values are for communicating relevant semantics of
367 * fields to the packet logging code. */
368 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
372 * Coroutine mechanics for the sillier bits of the code. If these
373 * macros look impenetrable to you, you might find it helpful to
376 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
378 * which explains the theory behind these macros.
380 * In particular, if you are getting `case expression not constant'
381 * errors when building with MS Visual Studio, this is because MS's
382 * Edit and Continue debugging feature causes their compiler to
383 * violate ANSI C. To disable Edit and Continue debugging:
385 * - right-click ssh.c in the FileView
387 * - select the C/C++ tab and the General category
388 * - under `Debug info:', select anything _other_ than `Program
389 * Database for Edit and Continue'.
391 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
394 if (!ssh->t) ssh->t = snew(struct t); \
396 #define crFinish(z) } *crLine = 0; return (z); }
397 #define crFinishV } *crLine = 0; return; }
398 #define crReturn(z) \
400 *crLine =__LINE__; return (z); case __LINE__:;\
404 *crLine=__LINE__; return; case __LINE__:;\
406 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
407 #define crStopV do{ *crLine = 0; return; }while(0)
408 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
409 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
411 typedef struct ssh_tag *Ssh;
414 static struct Packet *ssh1_pkt_init(int pkt_type);
415 static struct Packet *ssh2_pkt_init(int pkt_type);
416 static void ssh_pkt_ensure(struct Packet *, int length);
417 static void ssh_pkt_adddata(struct Packet *, void *data, int len);
418 static void ssh_pkt_addbyte(struct Packet *, unsigned char value);
419 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
420 static void ssh_pkt_adduint32(struct Packet *, unsigned long value);
421 static void ssh_pkt_addstring_start(struct Packet *);
422 static void ssh_pkt_addstring_str(struct Packet *, char *data);
423 static void ssh_pkt_addstring_data(struct Packet *, char *data, int len);
424 static void ssh_pkt_addstring(struct Packet *, char *data);
425 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
426 static void ssh1_pkt_addmp(struct Packet *, Bignum b);
427 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
428 static int ssh2_pkt_construct(Ssh, struct Packet *);
429 static void ssh2_pkt_send(Ssh, struct Packet *);
430 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
431 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
432 struct Packet *pktin);
433 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
434 struct Packet *pktin);
437 * Buffer management constants. There are several of these for
438 * various different purposes:
440 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
441 * on a local data stream before we throttle the whole SSH
442 * connection (in SSH-1 only). Throttling the whole connection is
443 * pretty drastic so we set this high in the hope it won't
446 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
447 * on the SSH connection itself before we defensively throttle
448 * _all_ local data streams. This is pretty drastic too (though
449 * thankfully unlikely in SSH-2 since the window mechanism should
450 * ensure that the server never has any need to throttle its end
451 * of the connection), so we set this high as well.
453 * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2
457 #define SSH1_BUFFER_LIMIT 32768
458 #define SSH_MAX_BACKLOG 32768
459 #define OUR_V2_WINSIZE 16384
460 #define OUR_V2_MAXPKT 0x4000UL
462 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
464 const static struct ssh_mac *macs[] = {
467 const static struct ssh_mac *buggymacs[] = {
468 &ssh_sha1_buggy, &ssh_md5
471 static void *ssh_comp_none_init(void)
475 static void ssh_comp_none_cleanup(void *handle)
478 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
479 unsigned char **outblock, int *outlen)
483 static int ssh_comp_none_disable(void *handle)
487 const static struct ssh_compress ssh_comp_none = {
489 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
490 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
491 ssh_comp_none_disable, NULL
493 extern const struct ssh_compress ssh_zlib;
494 const static struct ssh_compress *compressions[] = {
495 &ssh_zlib, &ssh_comp_none
498 enum { /* channel types */
503 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
507 * 2-3-4 tree storing channels.
510 Ssh ssh; /* pointer back to main context */
511 unsigned remoteid, localid;
513 /* True if we opened this channel but server hasn't confirmed. */
516 * In SSH-1, this value contains four bits:
518 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
519 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
520 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
521 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
523 * A channel is completely finished with when all four bits are set.
527 struct ssh1_data_channel {
530 struct ssh2_data_channel {
532 unsigned remwindow, remmaxpkt;
537 struct ssh_agent_channel {
538 unsigned char *message;
539 unsigned char msglen[4];
540 unsigned lensofar, totallen;
542 struct ssh_x11_channel {
545 struct ssh_pfd_channel {
552 * 2-3-4 tree storing remote->local port forwardings. SSH-1 and SSH-2
553 * use this structure in different ways, reflecting SSH-2's
554 * altogether saner approach to port forwarding.
556 * In SSH-1, you arrange a remote forwarding by sending the server
557 * the remote port number, and the local destination host:port.
558 * When a connection comes in, the server sends you back that
559 * host:port pair, and you connect to it. This is a ready-made
560 * security hole if you're not on the ball: a malicious server
561 * could send you back _any_ host:port pair, so if you trustingly
562 * connect to the address it gives you then you've just opened the
563 * entire inside of your corporate network just by connecting
564 * through it to a dodgy SSH server. Hence, we must store a list of
565 * host:port pairs we _are_ trying to forward to, and reject a
566 * connection request from the server if it's not in the list.
568 * In SSH-2, each side of the connection minds its own business and
569 * doesn't send unnecessary information to the other. You arrange a
570 * remote forwarding by sending the server just the remote port
571 * number. When a connection comes in, the server tells you which
572 * of its ports was connected to; and _you_ have to remember what
573 * local host:port pair went with that port number.
575 * Hence, in SSH-1 this structure is indexed by destination
576 * host:port pair, whereas in SSH-2 it is indexed by source port.
578 struct ssh_portfwd; /* forward declaration */
580 struct ssh_rportfwd {
581 unsigned sport, dport;
584 struct ssh_portfwd *pfrec;
586 #define free_rportfwd(pf) ( \
587 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
590 * Separately to the rportfwd tree (which is for looking up port
591 * open requests from the server), a tree of _these_ structures is
592 * used to keep track of all the currently open port forwardings,
593 * so that we can reconfigure in mid-session if the user requests
597 enum { DESTROY, KEEP, CREATE } status;
599 unsigned sport, dport;
602 struct ssh_rportfwd *remote;
606 #define free_portfwd(pf) ( \
607 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
608 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
611 long length; /* length of `data' actually used */
612 long forcepad; /* SSH-2: force padding to at least this length */
613 int type; /* only used for incoming packets */
614 unsigned long sequence; /* SSH-2 incoming sequence number */
615 unsigned char *data; /* allocated storage */
616 unsigned char *body; /* offset of payload within `data' */
617 long savedpos; /* temporary index into `data' (for strings) */
618 long maxlen; /* amount of storage allocated for `data' */
619 long encrypted_len; /* for SSH-2 total-size counting */
622 * State associated with packet logging
626 struct logblank_t *blanks;
629 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
630 struct Packet *pktin);
631 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
632 struct Packet *pktin);
633 static void ssh1_protocol_setup(Ssh ssh);
634 static void ssh2_protocol_setup(Ssh ssh);
635 static void ssh_size(void *handle, int width, int height);
636 static void ssh_special(void *handle, Telnet_Special);
637 static int ssh2_try_send(struct ssh_channel *c);
638 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
639 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
640 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
641 static int ssh_sendbuffer(void *handle);
642 static int ssh_do_close(Ssh ssh, int notify_exit);
643 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
644 static int ssh2_pkt_getbool(struct Packet *pkt);
645 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
646 static void ssh2_timer(void *ctx, long now);
647 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
648 struct Packet *pktin);
650 struct rdpkt1_state_tag {
651 long len, pad, biglen, to_read;
652 unsigned long realcrc, gotcrc;
656 struct Packet *pktin;
659 struct rdpkt2_state_tag {
660 long len, pad, payload, packetlen, maclen;
663 unsigned long incoming_sequence;
664 struct Packet *pktin;
667 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
668 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
670 struct queued_handler;
671 struct queued_handler {
673 chandler_fn_t handler;
675 struct queued_handler *next;
679 const struct plug_function_table *fn;
680 /* the above field _must_ be first in the structure */
682 SHA_State exhash, exhashbase;
689 unsigned char session_key[32];
691 int v1_remote_protoflags;
692 int v1_local_protoflags;
693 int agentfwd_enabled;
696 const struct ssh_cipher *cipher;
699 const struct ssh2_cipher *cscipher, *sccipher;
700 void *cs_cipher_ctx, *sc_cipher_ctx;
701 const struct ssh_mac *csmac, *scmac;
702 void *cs_mac_ctx, *sc_mac_ctx;
703 const struct ssh_compress *cscomp, *sccomp;
704 void *cs_comp_ctx, *sc_comp_ctx;
705 const struct ssh_kex *kex;
706 const struct ssh_signkey *hostkey;
707 unsigned char v2_session_id[20];
713 int echoing, editing;
717 int ospeed, ispeed; /* temporaries */
718 int term_width, term_height;
720 tree234 *channels; /* indexed by local id */
721 struct ssh_channel *mainchan; /* primary session channel */
726 tree234 *rportfwds, *portfwds;
730 SSH_STATE_BEFORE_SIZE,
736 int size_needed, eof_needed;
738 struct Packet **queue;
739 int queuelen, queuesize;
741 unsigned char *deferred_send_data;
742 int deferred_len, deferred_size;
745 * Gross hack: pscp will try to start SFTP but fall back to
746 * scp1 if that fails. This variable is the means by which
747 * scp.c can reach into the SSH code and find out which one it
752 bufchain banner; /* accumulates banners during do_ssh2_authconn */
754 * Used for username and password input.
756 char *userpass_input_buffer;
757 int userpass_input_buflen;
758 int userpass_input_bufpos;
759 int userpass_input_echo;
766 int v1_throttle_count;
769 int v1_stdout_throttling;
770 unsigned long v2_outgoing_sequence;
772 int ssh1_rdpkt_crstate;
773 int ssh2_rdpkt_crstate;
774 int do_ssh_init_crstate;
775 int ssh_gotdata_crstate;
776 int do_ssh1_login_crstate;
777 int do_ssh1_connection_crstate;
778 int do_ssh2_transport_crstate;
779 int do_ssh2_authconn_crstate;
781 void *do_ssh_init_state;
782 void *do_ssh1_login_state;
783 void *do_ssh2_transport_state;
784 void *do_ssh2_authconn_state;
786 struct rdpkt1_state_tag rdpkt1_state;
787 struct rdpkt2_state_tag rdpkt2_state;
789 /* SSH-1 and SSH-2 use this for different things, but both use it */
790 int protocol_initial_phase_done;
792 void (*protocol) (Ssh ssh, void *vin, int inlen,
794 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
797 * We maintain a full _copy_ of a Config structure here, not
798 * merely a pointer to it. That way, when we're passed a new
799 * one for reconfiguration, we can check the differences and
800 * potentially reconfigure port forwardings etc in mid-session.
805 * Used to transfer data back from async callbacks.
807 void *agent_response;
808 int agent_response_len;
812 * The SSH connection can be set as `frozen', meaning we are
813 * not currently accepting incoming data from the network. This
814 * is slightly more serious than setting the _socket_ as
815 * frozen, because we may already have had data passed to us
816 * from the network which we need to delay processing until
817 * after the freeze is lifted, so we also need a bufchain to
821 bufchain queued_incoming_data;
824 * Dispatch table for packet types that we may have to deal
827 handler_fn_t packet_dispatch[256];
830 * Queues of one-off handler functions for success/failure
831 * indications from a request.
833 struct queued_handler *qhead, *qtail;
836 * This module deals with sending keepalives.
841 * Track incoming and outgoing data sizes and time, for
844 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
845 unsigned long max_data_size;
847 long next_rekey, last_rekey;
848 char *deferred_rekey_reason; /* points to STATIC string; don't free */
851 #define logevent(s) logevent(ssh->frontend, s)
853 /* logevent, only printf-formatted. */
854 static void logeventf(Ssh ssh, const char *fmt, ...)
860 buf = dupvprintf(fmt, ap);
866 #define bombout(msg) \
868 char *text = dupprintf msg; \
869 ssh_do_close(ssh, FALSE); \
871 connection_fatal(ssh->frontend, "%s", text); \
875 /* Functions to leave bits out of the SSH packet log file. */
877 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
879 if (ssh->cfg.logomitpass)
880 pkt->logmode = blanktype;
883 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
885 if (ssh->cfg.logomitdata)
886 pkt->logmode = blanktype;
889 static void end_log_omission(Ssh ssh, struct Packet *pkt)
891 pkt->logmode = PKTLOG_EMIT;
894 /* Helper function for common bits of parsing cfg.ttymodes. */
895 static void parse_ttymodes(Ssh ssh, char *modes,
896 void (*do_mode)(void *data, char *mode, char *val),
900 char *t = strchr(modes, '\t');
901 char *m = snewn(t-modes+1, char);
903 strncpy(m, modes, t-modes);
906 val = get_ttymode(ssh->frontend, m);
910 do_mode(data, m, val);
913 modes += strlen(modes) + 1;
917 static int ssh_channelcmp(void *av, void *bv)
919 struct ssh_channel *a = (struct ssh_channel *) av;
920 struct ssh_channel *b = (struct ssh_channel *) bv;
921 if (a->localid < b->localid)
923 if (a->localid > b->localid)
927 static int ssh_channelfind(void *av, void *bv)
929 unsigned *a = (unsigned *) av;
930 struct ssh_channel *b = (struct ssh_channel *) bv;
938 static int ssh_rportcmp_ssh1(void *av, void *bv)
940 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
941 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
943 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
944 return i < 0 ? -1 : +1;
945 if (a->dport > b->dport)
947 if (a->dport < b->dport)
952 static int ssh_rportcmp_ssh2(void *av, void *bv)
954 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
955 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
957 if (a->sport > b->sport)
959 if (a->sport < b->sport)
965 * Special form of strcmp which can cope with NULL inputs. NULL is
966 * defined to sort before even the empty string.
968 static int nullstrcmp(const char *a, const char *b)
970 if (a == NULL && b == NULL)
979 static int ssh_portcmp(void *av, void *bv)
981 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
982 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
984 if (a->type > b->type)
986 if (a->type < b->type)
988 if (a->addressfamily > b->addressfamily)
990 if (a->addressfamily < b->addressfamily)
992 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
993 return i < 0 ? -1 : +1;
994 if (a->sport > b->sport)
996 if (a->sport < b->sport)
998 if (a->type != 'D') {
999 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
1000 return i < 0 ? -1 : +1;
1001 if (a->dport > b->dport)
1003 if (a->dport < b->dport)
1009 static int alloc_channel_id(Ssh ssh)
1011 const unsigned CHANNEL_NUMBER_OFFSET = 256;
1012 unsigned low, high, mid;
1014 struct ssh_channel *c;
1017 * First-fit allocation of channel numbers: always pick the
1018 * lowest unused one. To do this, binary-search using the
1019 * counted B-tree to find the largest channel ID which is in a
1020 * contiguous sequence from the beginning. (Precisely
1021 * everything in that sequence must have ID equal to its tree
1022 * index plus CHANNEL_NUMBER_OFFSET.)
1024 tsize = count234(ssh->channels);
1028 while (high - low > 1) {
1029 mid = (high + low) / 2;
1030 c = index234(ssh->channels, mid);
1031 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
1032 low = mid; /* this one is fine */
1034 high = mid; /* this one is past it */
1037 * Now low points to either -1, or the tree index of the
1038 * largest ID in the initial sequence.
1041 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
1042 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
1044 return low + 1 + CHANNEL_NUMBER_OFFSET;
1047 static void c_write(Ssh ssh, const char *buf, int len)
1049 if ((flags & FLAG_STDERR)) {
1051 for (i = 0; i < len; i++)
1053 fputc(buf[i], stderr);
1056 from_backend(ssh->frontend, 1, buf, len);
1059 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
1062 for (i = 0; i < len; i++) {
1064 c_write(ssh, "\r\n", 2);
1065 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
1066 c_write(ssh, buf + i, 1);
1070 static void c_write_str(Ssh ssh, const char *buf)
1072 c_write(ssh, buf, strlen(buf));
1075 static void ssh_free_packet(struct Packet *pkt)
1080 static struct Packet *ssh_new_packet(void)
1082 struct Packet *pkt = snew(struct Packet);
1084 pkt->body = pkt->data = NULL;
1086 pkt->logmode = PKTLOG_EMIT;
1094 * Collect incoming data in the incoming packet buffer.
1095 * Decipher and verify the packet when it is completely read.
1096 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
1097 * Update the *data and *datalen variables.
1098 * Return a Packet structure when a packet is completed.
1100 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1102 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
1104 crBegin(ssh->ssh1_rdpkt_crstate);
1106 st->pktin = ssh_new_packet();
1108 st->pktin->type = 0;
1109 st->pktin->length = 0;
1111 for (st->i = st->len = 0; st->i < 4; st->i++) {
1112 while ((*datalen) == 0)
1114 st->len = (st->len << 8) + **data;
1115 (*data)++, (*datalen)--;
1118 st->pad = 8 - (st->len % 8);
1119 st->biglen = st->len + st->pad;
1120 st->pktin->length = st->len - 5;
1122 if (st->biglen < 0) {
1123 bombout(("Extremely large packet length from server suggests"
1124 " data stream corruption"));
1125 ssh_free_packet(st->pktin);
1129 st->pktin->maxlen = st->biglen;
1130 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1132 st->to_read = st->biglen;
1133 st->p = st->pktin->data;
1134 while (st->to_read > 0) {
1135 st->chunk = st->to_read;
1136 while ((*datalen) == 0)
1138 if (st->chunk > (*datalen))
1139 st->chunk = (*datalen);
1140 memcpy(st->p, *data, st->chunk);
1142 *datalen -= st->chunk;
1144 st->to_read -= st->chunk;
1147 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1148 st->biglen, NULL)) {
1149 bombout(("Network attack (CRC compensation) detected!"));
1150 ssh_free_packet(st->pktin);
1155 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1157 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1158 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1159 if (st->gotcrc != st->realcrc) {
1160 bombout(("Incorrect CRC received on packet"));
1161 ssh_free_packet(st->pktin);
1165 st->pktin->body = st->pktin->data + st->pad + 1;
1166 st->pktin->savedpos = 0;
1168 if (ssh->v1_compressing) {
1169 unsigned char *decompblk;
1171 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1172 st->pktin->body - 1, st->pktin->length + 1,
1173 &decompblk, &decomplen)) {
1174 bombout(("Zlib decompression encountered invalid data"));
1175 ssh_free_packet(st->pktin);
1179 if (st->pktin->maxlen < st->pad + decomplen) {
1180 st->pktin->maxlen = st->pad + decomplen;
1181 st->pktin->data = sresize(st->pktin->data,
1182 st->pktin->maxlen + APIEXTRA,
1184 st->pktin->body = st->pktin->data + st->pad + 1;
1187 memcpy(st->pktin->body - 1, decompblk, decomplen);
1189 st->pktin->length = decomplen - 1;
1192 st->pktin->type = st->pktin->body[-1];
1195 * Log incoming packet, possibly omitting sensitive fields.
1199 struct logblank_t blank;
1200 if (ssh->cfg.logomitdata) {
1201 int do_blank = FALSE, blank_prefix = 0;
1202 /* "Session data" packets - omit the data field */
1203 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1204 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1205 do_blank = TRUE; blank_prefix = 0;
1206 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1207 do_blank = TRUE; blank_prefix = 4;
1210 blank.offset = blank_prefix;
1211 blank.len = st->pktin->length;
1212 blank.type = PKTLOG_OMIT;
1216 log_packet(ssh->logctx,
1217 PKT_INCOMING, st->pktin->type,
1218 ssh1_pkt_type(st->pktin->type),
1219 st->pktin->body, st->pktin->length,
1223 crFinish(st->pktin);
1226 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1228 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1230 crBegin(ssh->ssh2_rdpkt_crstate);
1232 st->pktin = ssh_new_packet();
1234 st->pktin->type = 0;
1235 st->pktin->length = 0;
1237 st->cipherblk = ssh->sccipher->blksize;
1240 if (st->cipherblk < 8)
1243 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1246 * Acquire and decrypt the first block of the packet. This will
1247 * contain the length and padding details.
1249 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1250 while ((*datalen) == 0)
1252 st->pktin->data[st->i] = *(*data)++;
1257 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1258 st->pktin->data, st->cipherblk);
1261 * Now get the length and padding figures.
1263 st->len = GET_32BIT(st->pktin->data);
1264 st->pad = st->pktin->data[4];
1267 * _Completely_ silly lengths should be stomped on before they
1268 * do us any more damage.
1270 if (st->len < 0 || st->len > 35000 || st->pad < 4 ||
1271 st->len - st->pad < 1 || (st->len + 4) % st->cipherblk != 0) {
1272 bombout(("Incoming packet was garbled on decryption"));
1273 ssh_free_packet(st->pktin);
1278 * This enables us to deduce the payload length.
1280 st->payload = st->len - st->pad - 1;
1282 st->pktin->length = st->payload + 5;
1285 * So now we can work out the total packet length.
1287 st->packetlen = st->len + 4;
1288 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1291 * Allocate memory for the rest of the packet.
1293 st->pktin->maxlen = st->packetlen + st->maclen;
1294 st->pktin->data = sresize(st->pktin->data,
1295 st->pktin->maxlen + APIEXTRA,
1299 * Read and decrypt the remainder of the packet.
1301 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1303 while ((*datalen) == 0)
1305 st->pktin->data[st->i] = *(*data)++;
1308 /* Decrypt everything _except_ the MAC. */
1310 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1311 st->pktin->data + st->cipherblk,
1312 st->packetlen - st->cipherblk);
1314 st->pktin->encrypted_len = st->packetlen;
1320 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1321 st->incoming_sequence)) {
1322 bombout(("Incorrect MAC received on packet"));
1323 ssh_free_packet(st->pktin);
1327 st->pktin->sequence = st->incoming_sequence++;
1330 * Decompress packet payload.
1333 unsigned char *newpayload;
1336 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1337 st->pktin->data + 5, st->pktin->length - 5,
1338 &newpayload, &newlen)) {
1339 if (st->pktin->maxlen < newlen + 5) {
1340 st->pktin->maxlen = newlen + 5;
1341 st->pktin->data = sresize(st->pktin->data,
1342 st->pktin->maxlen + APIEXTRA,
1345 st->pktin->length = 5 + newlen;
1346 memcpy(st->pktin->data + 5, newpayload, newlen);
1351 st->pktin->savedpos = 6;
1352 st->pktin->body = st->pktin->data;
1353 st->pktin->type = st->pktin->data[5];
1356 * Log incoming packet, possibly omitting sensitive fields.
1360 struct logblank_t blank;
1361 if (ssh->cfg.logomitdata) {
1362 int do_blank = FALSE, blank_prefix = 0;
1363 /* "Session data" packets - omit the data field */
1364 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1365 do_blank = TRUE; blank_prefix = 4;
1366 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1367 do_blank = TRUE; blank_prefix = 8;
1370 blank.offset = blank_prefix;
1371 blank.len = (st->pktin->length-6) - blank_prefix;
1372 blank.type = PKTLOG_OMIT;
1376 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1377 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1378 st->pktin->data+6, st->pktin->length-6,
1382 crFinish(st->pktin);
1385 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p)
1387 int pad, biglen, i, pktoffs;
1391 * XXX various versions of SC (including 8.8.4) screw up the
1392 * register allocation in this function and use the same register
1393 * (D6) for len and as a temporary, with predictable results. The
1394 * following sledgehammer prevents this.
1401 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12],
1402 ssh1_pkt_type(pkt->data[12]),
1403 pkt->body, pkt->length - (pkt->body - pkt->data),
1404 pkt->nblanks, pkt->blanks);
1405 sfree(pkt->blanks); pkt->blanks = NULL;
1408 if (ssh->v1_compressing) {
1409 unsigned char *compblk;
1411 zlib_compress_block(ssh->cs_comp_ctx,
1412 pkt->data + 12, pkt->length - 12,
1413 &compblk, &complen);
1414 memcpy(pkt->data + 12, compblk, complen);
1416 pkt->length = complen + 12;
1419 ssh_pkt_ensure(pkt, pkt->length + 4); /* space for CRC */
1421 len = pkt->length - 4 - 8; /* len(type+data+CRC) */
1422 pad = 8 - (len % 8);
1424 biglen = len + pad; /* len(padding+type+data+CRC) */
1426 for (i = pktoffs; i < 4+8; i++)
1427 pkt->data[i] = random_byte();
1428 crc = crc32_compute(pkt->data + pktoffs + 4, biglen - 4); /* all ex len */
1429 PUT_32BIT(pkt->data + pktoffs + 4 + biglen - 4, crc);
1430 PUT_32BIT(pkt->data + pktoffs, len);
1433 ssh->cipher->encrypt(ssh->v1_cipher_ctx,
1434 pkt->data + pktoffs + 4, biglen);
1436 if (offset_p) *offset_p = pktoffs;
1437 return biglen + 4; /* len(length+padding+type+data+CRC) */
1440 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1442 int len, backlog, offset;
1443 len = s_wrpkt_prepare(ssh, pkt, &offset);
1444 backlog = sk_write(ssh->s, (char *)pkt->data + offset, len);
1445 if (backlog > SSH_MAX_BACKLOG)
1446 ssh_throttle_all(ssh, 1, backlog);
1447 ssh_free_packet(pkt);
1450 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1453 len = s_wrpkt_prepare(ssh, pkt, &offset);
1454 if (ssh->deferred_len + len > ssh->deferred_size) {
1455 ssh->deferred_size = ssh->deferred_len + len + 128;
1456 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1460 memcpy(ssh->deferred_send_data + ssh->deferred_len,
1461 pkt->data + offset, len);
1462 ssh->deferred_len += len;
1463 ssh_free_packet(pkt);
1467 * Construct a SSH-1 packet with the specified contents.
1468 * (This all-at-once interface used to be the only one, but now SSH-1
1469 * packets can also be constructed incrementally.)
1471 static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap)
1477 pkt = ssh1_pkt_init(pkttype);
1479 while ((argtype = va_arg(ap, int)) != PKT_END) {
1480 unsigned char *argp, argchar;
1481 unsigned long argint;
1484 /* Actual fields in the packet */
1486 argint = va_arg(ap, int);
1487 ssh_pkt_adduint32(pkt, argint);
1490 argchar = (unsigned char) va_arg(ap, int);
1491 ssh_pkt_addbyte(pkt, argchar);
1494 argp = va_arg(ap, unsigned char *);
1495 arglen = va_arg(ap, int);
1496 ssh_pkt_adddata(pkt, argp, arglen);
1499 argp = va_arg(ap, unsigned char *);
1500 ssh_pkt_addstring(pkt, argp);
1503 bn = va_arg(ap, Bignum);
1504 ssh1_pkt_addmp(pkt, bn);
1506 /* Tokens for modifications to packet logging */
1508 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1511 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1514 end_log_omission(ssh, pkt);
1522 static void send_packet(Ssh ssh, int pkttype, ...)
1526 va_start(ap, pkttype);
1527 pkt = construct_packet(ssh, pkttype, ap);
1532 static void defer_packet(Ssh ssh, int pkttype, ...)
1536 va_start(ap, pkttype);
1537 pkt = construct_packet(ssh, pkttype, ap);
1539 s_wrpkt_defer(ssh, pkt);
1542 static int ssh_versioncmp(char *a, char *b)
1545 unsigned long av, bv;
1547 av = strtoul(a, &ae, 10);
1548 bv = strtoul(b, &be, 10);
1550 return (av < bv ? -1 : +1);
1555 av = strtoul(ae, &ae, 10);
1556 bv = strtoul(be, &be, 10);
1558 return (av < bv ? -1 : +1);
1563 * Utility routines for putting an SSH-protocol `string' and
1564 * `uint32' into a SHA state.
1566 static void sha_string(SHA_State * s, void *str, int len)
1568 unsigned char lenblk[4];
1569 PUT_32BIT(lenblk, len);
1570 SHA_Bytes(s, lenblk, 4);
1571 SHA_Bytes(s, str, len);
1574 static void sha_uint32(SHA_State * s, unsigned i)
1576 unsigned char intblk[4];
1577 PUT_32BIT(intblk, i);
1578 SHA_Bytes(s, intblk, 4);
1582 * Packet construction functions. Mostly shared between SSH-1 and SSH-2.
1584 static void ssh_pkt_ensure(struct Packet *pkt, int length)
1586 if (pkt->maxlen < length) {
1587 unsigned char *body = pkt->body;
1588 int offset = body ? pkt->data - body : 0;
1589 pkt->maxlen = length + 256;
1590 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1591 if (body) pkt->body = pkt->data + offset;
1594 static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len)
1596 if (pkt->logmode != PKTLOG_EMIT) {
1598 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1600 pkt->blanks[pkt->nblanks-1].offset = pkt->length -
1601 (pkt->body - pkt->data);
1602 pkt->blanks[pkt->nblanks-1].len = len;
1603 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1606 ssh_pkt_ensure(pkt, pkt->length);
1607 memcpy(pkt->data + pkt->length - len, data, len);
1609 static void ssh_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1611 ssh_pkt_adddata(pkt, &byte, 1);
1613 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1615 ssh_pkt_adddata(pkt, &value, 1);
1617 static void ssh_pkt_adduint32(struct Packet *pkt, unsigned long value)
1620 PUT_32BIT(x, value);
1621 ssh_pkt_adddata(pkt, x, 4);
1623 static void ssh_pkt_addstring_start(struct Packet *pkt)
1625 ssh_pkt_adduint32(pkt, 0);
1626 pkt->savedpos = pkt->length;
1628 static void ssh_pkt_addstring_str(struct Packet *pkt, char *data)
1630 ssh_pkt_adddata(pkt, data, strlen(data));
1631 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1633 static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1635 ssh_pkt_adddata(pkt, data, len);
1636 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1638 static void ssh_pkt_addstring(struct Packet *pkt, char *data)
1640 ssh_pkt_addstring_start(pkt);
1641 ssh_pkt_addstring_str(pkt, data);
1643 static void ssh1_pkt_addmp(struct Packet *pkt, Bignum b)
1645 int len = ssh1_bignum_length(b);
1646 unsigned char *data = snewn(len, char);
1647 (void) ssh1_write_bignum(data, b);
1648 ssh_pkt_adddata(pkt, data, len);
1651 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1654 int i, n = (bignum_bitcount(b) + 7) / 8;
1655 p = snewn(n + 1, unsigned char);
1657 for (i = 1; i <= n; i++)
1658 p[i] = bignum_byte(b, n - i);
1660 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1662 memmove(p, p + i, n + 1 - i);
1666 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1670 p = ssh2_mpint_fmt(b, &len);
1671 ssh_pkt_addstring_start(pkt);
1672 ssh_pkt_addstring_data(pkt, (char *)p, len);
1676 static struct Packet *ssh1_pkt_init(int pkt_type)
1678 struct Packet *pkt = ssh_new_packet();
1679 pkt->length = 4 + 8; /* space for length + max padding */
1680 ssh_pkt_addbyte(pkt, pkt_type);
1681 pkt->body = pkt->data + pkt->length;
1685 /* For legacy code (SSH-1 and -2 packet construction used to be separate) */
1686 #define ssh2_pkt_ensure(pkt, length) ssh_pkt_ensure(pkt, length)
1687 #define ssh2_pkt_adddata(pkt, data, len) ssh_pkt_adddata(pkt, data, len)
1688 #define ssh2_pkt_addbyte(pkt, byte) ssh_pkt_addbyte(pkt, byte)
1689 #define ssh2_pkt_adduint32(pkt, value) ssh_pkt_adduint32(pkt, value)
1690 #define ssh2_pkt_addstring_start(pkt) ssh_pkt_addstring_start(pkt)
1691 #define ssh2_pkt_addstring_str(pkt, data) ssh_pkt_addstring_str(pkt, data)
1692 #define ssh2_pkt_addstring_data(pkt, data, len) ssh_pkt_addstring_data(pkt, data, len)
1693 #define ssh2_pkt_addstring(pkt, data) ssh_pkt_addstring(pkt, data)
1695 static struct Packet *ssh2_pkt_init(int pkt_type)
1697 struct Packet *pkt = ssh_new_packet();
1700 ssh_pkt_addbyte(pkt, (unsigned char) pkt_type);
1701 pkt->body = pkt->data + pkt->length;
1706 * Construct an SSH-2 final-form packet: compress it, encrypt it,
1707 * put the MAC on it. Final packet, ready to be sent, is stored in
1708 * pkt->data. Total length is returned.
1710 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1712 int cipherblk, maclen, padding, i;
1715 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1716 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1717 pkt->body, pkt->length - (pkt->body - pkt->data),
1718 pkt->nblanks, pkt->blanks);
1719 sfree(pkt->blanks); pkt->blanks = NULL;
1723 * Compress packet payload.
1726 unsigned char *newpayload;
1729 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1731 &newpayload, &newlen)) {
1733 ssh2_pkt_adddata(pkt, newpayload, newlen);
1739 * Add padding. At least four bytes, and must also bring total
1740 * length (minus MAC) up to a multiple of the block size.
1741 * If pkt->forcepad is set, make sure the packet is at least that size
1744 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1745 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1747 if (pkt->length + padding < pkt->forcepad)
1748 padding = pkt->forcepad - pkt->length;
1750 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1751 assert(padding <= 255);
1752 maclen = ssh->csmac ? ssh->csmac->len : 0;
1753 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1754 pkt->data[4] = padding;
1755 for (i = 0; i < padding; i++)
1756 pkt->data[pkt->length + i] = random_byte();
1757 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1759 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1760 pkt->length + padding,
1761 ssh->v2_outgoing_sequence);
1762 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1765 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1766 pkt->data, pkt->length + padding);
1768 pkt->encrypted_len = pkt->length + padding;
1770 /* Ready-to-send packet starts at pkt->data. We return length. */
1771 return pkt->length + padding + maclen;
1775 * Routines called from the main SSH code to send packets. There
1776 * are quite a few of these, because we have two separate
1777 * mechanisms for delaying the sending of packets:
1779 * - In order to send an IGNORE message and a password message in
1780 * a single fixed-length blob, we require the ability to
1781 * concatenate the encrypted forms of those two packets _into_ a
1782 * single blob and then pass it to our <network.h> transport
1783 * layer in one go. Hence, there's a deferment mechanism which
1784 * works after packet encryption.
1786 * - In order to avoid sending any connection-layer messages
1787 * during repeat key exchange, we have to queue up any such
1788 * outgoing messages _before_ they are encrypted (and in
1789 * particular before they're allocated sequence numbers), and
1790 * then send them once we've finished.
1792 * I call these mechanisms `defer' and `queue' respectively, so as
1793 * to distinguish them reasonably easily.
1795 * The functions send_noqueue() and defer_noqueue() free the packet
1796 * structure they are passed. Every outgoing packet goes through
1797 * precisely one of these functions in its life; packets passed to
1798 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1799 * these or get queued, and then when the queue is later emptied
1800 * the packets are all passed to defer_noqueue().
1802 * When using a CBC-mode cipher, it's necessary to ensure that an
1803 * attacker can't provide data to be encrypted using an IV that they
1804 * know. We ensure this by prefixing each packet that might contain
1805 * user data with an SSH_MSG_IGNORE. This is done using the deferral
1806 * mechanism, so in this case send_noqueue() ends up redirecting to
1807 * defer_noqueue(). If you don't like this inefficiency, don't use
1811 static void ssh2_pkt_defer_noqueue(Ssh, struct Packet *, int);
1812 static void ssh_pkt_defersend(Ssh);
1815 * Send an SSH-2 packet immediately, without queuing or deferring.
1817 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1821 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC)) {
1822 /* We need to send two packets, so use the deferral mechanism. */
1823 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1824 ssh_pkt_defersend(ssh);
1827 len = ssh2_pkt_construct(ssh, pkt);
1828 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1829 if (backlog > SSH_MAX_BACKLOG)
1830 ssh_throttle_all(ssh, 1, backlog);
1832 ssh->outgoing_data_size += pkt->encrypted_len;
1833 if (!ssh->kex_in_progress &&
1834 ssh->max_data_size != 0 &&
1835 ssh->outgoing_data_size > ssh->max_data_size)
1836 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1838 ssh_free_packet(pkt);
1842 * Defer an SSH-2 packet.
1844 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore)
1847 if (ssh->cscipher != NULL && (ssh->cscipher->flags & SSH_CIPHER_IS_CBC) &&
1848 ssh->deferred_len == 0 && !noignore) {
1850 * Interpose an SSH_MSG_IGNORE to ensure that user data don't
1851 * get encrypted with a known IV.
1853 struct Packet *ipkt = ssh2_pkt_init(SSH2_MSG_IGNORE);
1854 ssh2_pkt_defer_noqueue(ssh, ipkt, TRUE);
1856 len = ssh2_pkt_construct(ssh, pkt);
1857 if (ssh->deferred_len + len > ssh->deferred_size) {
1858 ssh->deferred_size = ssh->deferred_len + len + 128;
1859 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1863 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1864 ssh->deferred_len += len;
1865 ssh->deferred_data_size += pkt->encrypted_len;
1866 ssh_free_packet(pkt);
1870 * Queue an SSH-2 packet.
1872 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1874 assert(ssh->queueing);
1876 if (ssh->queuelen >= ssh->queuesize) {
1877 ssh->queuesize = ssh->queuelen + 32;
1878 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1881 ssh->queue[ssh->queuelen++] = pkt;
1885 * Either queue or send a packet, depending on whether queueing is
1888 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1891 ssh2_pkt_queue(ssh, pkt);
1893 ssh2_pkt_send_noqueue(ssh, pkt);
1898 * Either queue or defer a packet, depending on whether queueing is
1901 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1904 ssh2_pkt_queue(ssh, pkt);
1906 ssh2_pkt_defer_noqueue(ssh, pkt, FALSE);
1911 * Send the whole deferred data block constructed by
1912 * ssh2_pkt_defer() or SSH-1's defer_packet().
1914 * The expected use of the defer mechanism is that you call
1915 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1916 * not currently queueing, this simply sets up deferred_send_data
1917 * and then sends it. If we _are_ currently queueing, the calls to
1918 * ssh2_pkt_defer() put the deferred packets on to the queue
1919 * instead, and therefore ssh_pkt_defersend() has no deferred data
1920 * to send. Hence, there's no need to make it conditional on
1923 static void ssh_pkt_defersend(Ssh ssh)
1926 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1928 ssh->deferred_len = ssh->deferred_size = 0;
1929 sfree(ssh->deferred_send_data);
1930 ssh->deferred_send_data = NULL;
1931 if (backlog > SSH_MAX_BACKLOG)
1932 ssh_throttle_all(ssh, 1, backlog);
1934 ssh->outgoing_data_size += ssh->deferred_data_size;
1935 if (!ssh->kex_in_progress &&
1936 ssh->max_data_size != 0 &&
1937 ssh->outgoing_data_size > ssh->max_data_size)
1938 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1939 ssh->deferred_data_size = 0;
1943 * Send all queued SSH-2 packets. We send them by means of
1944 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1945 * packets that needed to be lumped together.
1947 static void ssh2_pkt_queuesend(Ssh ssh)
1951 assert(!ssh->queueing);
1953 for (i = 0; i < ssh->queuelen; i++)
1954 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i], FALSE);
1957 ssh_pkt_defersend(ssh);
1961 void bndebug(char *string, Bignum b)
1965 p = ssh2_mpint_fmt(b, &len);
1966 debug(("%s", string));
1967 for (i = 0; i < len; i++)
1968 debug((" %02x", p[i]));
1974 static void sha_mpint(SHA_State * s, Bignum b)
1978 p = ssh2_mpint_fmt(b, &len);
1979 sha_string(s, p, len);
1984 * Packet decode functions for both SSH-1 and SSH-2.
1986 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1988 unsigned long value;
1989 if (pkt->length - pkt->savedpos < 4)
1990 return 0; /* arrgh, no way to decline (FIXME?) */
1991 value = GET_32BIT(pkt->body + pkt->savedpos);
1995 static int ssh2_pkt_getbool(struct Packet *pkt)
1997 unsigned long value;
1998 if (pkt->length - pkt->savedpos < 1)
1999 return 0; /* arrgh, no way to decline (FIXME?) */
2000 value = pkt->body[pkt->savedpos] != 0;
2004 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
2009 if (pkt->length - pkt->savedpos < 4)
2011 len = GET_32BIT(pkt->body + pkt->savedpos);
2016 if (pkt->length - pkt->savedpos < *length)
2018 *p = (char *)(pkt->body + pkt->savedpos);
2019 pkt->savedpos += *length;
2021 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
2023 if (pkt->length - pkt->savedpos < length)
2025 pkt->savedpos += length;
2026 return pkt->body + (pkt->savedpos - length);
2028 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
2029 unsigned char **keystr)
2033 j = makekey(pkt->body + pkt->savedpos,
2034 pkt->length - pkt->savedpos,
2041 assert(pkt->savedpos < pkt->length);
2045 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
2050 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
2051 pkt->length - pkt->savedpos, &b);
2059 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
2065 ssh_pkt_getstring(pkt, &p, &length);
2070 b = bignum_from_bytes((unsigned char *)p, length);
2075 * Helper function to add an SSH-2 signature blob to a packet.
2076 * Expects to be shown the public key blob as well as the signature
2077 * blob. Normally works just like ssh2_pkt_addstring, but will
2078 * fiddle with the signature packet if necessary for
2079 * BUG_SSH2_RSA_PADDING.
2081 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
2082 void *pkblob_v, int pkblob_len,
2083 void *sigblob_v, int sigblob_len)
2085 unsigned char *pkblob = (unsigned char *)pkblob_v;
2086 unsigned char *sigblob = (unsigned char *)sigblob_v;
2088 /* dmemdump(pkblob, pkblob_len); */
2089 /* dmemdump(sigblob, sigblob_len); */
2092 * See if this is in fact an ssh-rsa signature and a buggy
2093 * server; otherwise we can just do this the easy way.
2095 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
2096 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
2097 int pos, len, siglen;
2100 * Find the byte length of the modulus.
2103 pos = 4+7; /* skip over "ssh-rsa" */
2104 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
2105 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2106 pos += 4; /* find modulus itself */
2107 while (len > 0 && pkblob[pos] == 0)
2109 /* debug(("modulus length is %d\n", len)); */
2112 * Now find the signature integer.
2114 pos = 4+7; /* skip over "ssh-rsa" */
2115 siglen = GET_32BIT(sigblob+pos);
2116 /* debug(("signature length is %d\n", siglen)); */
2118 if (len != siglen) {
2119 unsigned char newlen[4];
2120 ssh2_pkt_addstring_start(pkt);
2121 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2122 /* dmemdump(sigblob, pos); */
2123 pos += 4; /* point to start of actual sig */
2124 PUT_32BIT(newlen, len);
2125 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2126 /* dmemdump(newlen, 4); */
2128 while (len-- > siglen) {
2129 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2130 /* dmemdump(newlen, 1); */
2132 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2133 /* dmemdump(sigblob+pos, siglen); */
2137 /* Otherwise fall through and do it the easy way. */
2140 ssh2_pkt_addstring_start(pkt);
2141 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2145 * Examine the remote side's version string and compare it against
2146 * a list of known buggy implementations.
2148 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2150 char *imp; /* pointer to implementation part */
2152 imp += strcspn(imp, "-");
2154 imp += strcspn(imp, "-");
2157 ssh->remote_bugs = 0;
2159 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2160 (ssh->cfg.sshbug_ignore1 == AUTO &&
2161 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2162 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2163 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2164 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2166 * These versions don't support SSH1_MSG_IGNORE, so we have
2167 * to use a different defence against password length
2170 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2171 logevent("We believe remote version has SSH-1 ignore bug");
2174 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2175 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2176 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2178 * These versions need a plain password sent; they can't
2179 * handle having a null and a random length of data after
2182 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2183 logevent("We believe remote version needs a plain SSH-1 password");
2186 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2187 (ssh->cfg.sshbug_rsa1 == AUTO &&
2188 (!strcmp(imp, "Cisco-1.25")))) {
2190 * These versions apparently have no clue whatever about
2191 * RSA authentication and will panic and die if they see
2192 * an AUTH_RSA message.
2194 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2195 logevent("We believe remote version can't handle SSH-1 RSA authentication");
2198 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2199 (ssh->cfg.sshbug_hmac2 == AUTO &&
2200 !wc_match("* VShell", imp) &&
2201 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2202 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2203 wc_match("2.1 *", imp)))) {
2205 * These versions have the HMAC bug.
2207 ssh->remote_bugs |= BUG_SSH2_HMAC;
2208 logevent("We believe remote version has SSH-2 HMAC bug");
2211 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2212 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2213 !wc_match("* VShell", imp) &&
2214 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2216 * These versions have the key-derivation bug (failing to
2217 * include the literal shared secret in the hashes that
2218 * generate the keys).
2220 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2221 logevent("We believe remote version has SSH-2 key-derivation bug");
2224 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2225 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2226 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2227 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2229 * These versions have the SSH-2 RSA padding bug.
2231 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2232 logevent("We believe remote version has SSH-2 RSA padding bug");
2235 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2236 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2237 wc_match("OpenSSH_2.[0-2]*", imp))) {
2239 * These versions have the SSH-2 session-ID bug in
2240 * public-key authentication.
2242 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2243 logevent("We believe remote version has SSH-2 public-key-session-ID bug");
2246 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2247 (ssh->cfg.sshbug_rekey2 == AUTO &&
2248 (wc_match("DigiSSH_2.0", imp) ||
2249 wc_match("OpenSSH_2.[0-4]*", imp) ||
2250 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2251 wc_match("Sun_SSH_1.0", imp) ||
2252 wc_match("Sun_SSH_1.0.1", imp) ||
2253 /* All versions <= 1.2.6 (they changed their format in 1.2.7) */
2254 wc_match("WeOnlyDo-*", imp)))) {
2256 * These versions have the SSH-2 rekey bug.
2258 ssh->remote_bugs |= BUG_SSH2_REKEY;
2259 logevent("We believe remote version has SSH-2 rekey bug");
2264 * The `software version' part of an SSH version string is required
2265 * to contain no spaces or minus signs.
2267 static void ssh_fix_verstring(char *str)
2269 /* Eat "SSH-<protoversion>-". */
2270 assert(*str == 'S'); str++;
2271 assert(*str == 'S'); str++;
2272 assert(*str == 'H'); str++;
2273 assert(*str == '-'); str++;
2274 while (*str && *str != '-') str++;
2275 assert(*str == '-'); str++;
2277 /* Convert minus signs and spaces in the remaining string into
2280 if (*str == '-' || *str == ' ')
2286 static int do_ssh_init(Ssh ssh, unsigned char c)
2288 struct do_ssh_init_state {
2296 crState(do_ssh_init_state);
2298 crBegin(ssh->do_ssh_init_crstate);
2300 /* Search for a line beginning with the string "SSH-" in the input. */
2302 if (c != 'S') goto no;
2304 if (c != 'S') goto no;
2306 if (c != 'H') goto no;
2308 if (c != '-') goto no;
2317 s->vstring = snewn(s->vstrsize, char);
2318 strcpy(s->vstring, "SSH-");
2322 crReturn(1); /* get another char */
2323 if (s->vslen >= s->vstrsize - 1) {
2325 s->vstring = sresize(s->vstring, s->vstrsize, char);
2327 s->vstring[s->vslen++] = c;
2330 s->version[s->i] = '\0';
2332 } else if (s->i < sizeof(s->version) - 1)
2333 s->version[s->i++] = c;
2334 } else if (c == '\012')
2338 ssh->agentfwd_enabled = FALSE;
2339 ssh->rdpkt2_state.incoming_sequence = 0;
2341 s->vstring[s->vslen] = 0;
2342 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2343 logeventf(ssh, "Server version: %s", s->vstring);
2344 ssh_detect_bugs(ssh, s->vstring);
2347 * Decide which SSH protocol version to support.
2350 /* Anything strictly below "2.0" means protocol 1 is supported. */
2351 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2352 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2353 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2355 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2356 bombout(("SSH protocol version 1 required by user but not provided by server"));
2359 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2360 bombout(("SSH protocol version 2 required by user but not provided by server"));
2367 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2369 * Construct a v2 version string.
2371 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2375 * Construct a v1 version string.
2377 verstring = dupprintf("SSH-%s-%s\012",
2378 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2379 s->version : "1.5"),
2384 ssh_fix_verstring(verstring);
2386 if (ssh->version == 2) {
2388 * Hash our version string and their version string.
2390 SHA_Init(&ssh->exhashbase);
2391 sha_string(&ssh->exhashbase, verstring,
2392 strcspn(verstring, "\015\012"));
2393 sha_string(&ssh->exhashbase, s->vstring,
2394 strcspn(s->vstring, "\015\012"));
2397 * Initialise SSH-2 protocol.
2399 ssh->protocol = ssh2_protocol;
2400 ssh2_protocol_setup(ssh);
2401 ssh->s_rdpkt = ssh2_rdpkt;
2404 * Initialise SSH-1 protocol.
2406 ssh->protocol = ssh1_protocol;
2407 ssh1_protocol_setup(ssh);
2408 ssh->s_rdpkt = ssh1_rdpkt;
2410 logeventf(ssh, "We claim version: %.*s",
2411 strcspn(verstring, "\015\012"), verstring);
2412 sk_write(ssh->s, verstring, strlen(verstring));
2414 if (ssh->version == 2)
2415 do_ssh2_transport(ssh, NULL, -1, NULL);
2418 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2420 update_specials_menu(ssh->frontend);
2421 ssh->state = SSH_STATE_BEFORE_SIZE;
2422 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2429 static void ssh_process_incoming_data(Ssh ssh,
2430 unsigned char **data, int *datalen)
2432 struct Packet *pktin = ssh->s_rdpkt(ssh, data, datalen);
2434 ssh->protocol(ssh, NULL, 0, pktin);
2435 ssh_free_packet(pktin);
2439 static void ssh_queue_incoming_data(Ssh ssh,
2440 unsigned char **data, int *datalen)
2442 bufchain_add(&ssh->queued_incoming_data, *data, *datalen);
2447 static void ssh_process_queued_incoming_data(Ssh ssh)
2450 unsigned char *data;
2453 while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) {
2454 bufchain_prefix(&ssh->queued_incoming_data, &vdata, &len);
2458 while (!ssh->frozen && len > 0)
2459 ssh_process_incoming_data(ssh, &data, &len);
2462 bufchain_consume(&ssh->queued_incoming_data, origlen - len);
2466 static void ssh_set_frozen(Ssh ssh, int frozen)
2469 sk_set_frozen(ssh->s, frozen);
2470 ssh->frozen = frozen;
2473 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2475 crBegin(ssh->ssh_gotdata_crstate);
2478 * To begin with, feed the characters one by one to the
2479 * protocol initialisation / selection function do_ssh_init().
2480 * When that returns 0, we're done with the initial greeting
2481 * exchange and can move on to packet discipline.
2484 int ret; /* need not be kept across crReturn */
2486 crReturnV; /* more data please */
2487 ret = do_ssh_init(ssh, *data);
2495 * We emerge from that loop when the initial negotiation is
2496 * over and we have selected an s_rdpkt function. Now pass
2497 * everything to s_rdpkt, and then pass the resulting packets
2498 * to the proper protocol handler.
2502 while (bufchain_size(&ssh->queued_incoming_data) > 0 || datalen > 0) {
2504 ssh_queue_incoming_data(ssh, &data, &datalen);
2505 /* This uses up all data and cannot cause anything interesting
2506 * to happen; indeed, for anything to happen at all, we must
2507 * return, so break out. */
2509 } else if (bufchain_size(&ssh->queued_incoming_data) > 0) {
2510 /* This uses up some or all data, and may freeze the
2512 ssh_process_queued_incoming_data(ssh);
2514 /* This uses up some or all data, and may freeze the
2516 ssh_process_incoming_data(ssh, &data, &datalen);
2518 /* FIXME this is probably EBW. */
2519 if (ssh->state == SSH_STATE_CLOSED)
2522 /* We're out of data. Go and get some more. */
2528 static int ssh_do_close(Ssh ssh, int notify_exit)
2531 struct ssh_channel *c;
2533 ssh->state = SSH_STATE_CLOSED;
2534 expire_timer_context(ssh);
2539 notify_remote_exit(ssh->frontend);
2544 * Now we must shut down any port- and X-forwarded channels going
2545 * through this connection.
2547 if (ssh->channels) {
2548 while (NULL != (c = index234(ssh->channels, 0))) {
2551 x11_close(c->u.x11.s);
2554 pfd_close(c->u.pfd.s);
2557 del234(ssh->channels, c); /* moving next one to index 0 */
2558 if (ssh->version == 2)
2559 bufchain_clear(&c->v.v2.outbuffer);
2564 * Go through port-forwardings, and close any associated
2565 * listening sockets.
2567 if (ssh->portfwds) {
2568 struct ssh_portfwd *pf;
2569 while (NULL != (pf = index234(ssh->portfwds, 0))) {
2570 /* Dispose of any listening socket. */
2572 pfd_terminate(pf->local);
2573 del234(ssh->portfwds, pf); /* moving next one to index 0 */
2581 static void ssh_log(Plug plug, int type, SockAddr addr, int port,
2582 const char *error_msg, int error_code)
2584 Ssh ssh = (Ssh) plug;
2585 char addrbuf[256], *msg;
2587 sk_getaddr(addr, addrbuf, lenof(addrbuf));
2590 msg = dupprintf("Connecting to %s port %d", addrbuf, port);
2592 msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
2598 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2601 Ssh ssh = (Ssh) plug;
2602 int need_notify = ssh_do_close(ssh, FALSE);
2605 if (!ssh->close_expected)
2606 error_msg = "Server unexpectedly closed network connection";
2608 error_msg = "Server closed network connection";
2612 notify_remote_exit(ssh->frontend);
2615 logevent(error_msg);
2616 if (!ssh->close_expected || !ssh->clean_exit)
2617 connection_fatal(ssh->frontend, "%s", error_msg);
2621 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2623 Ssh ssh = (Ssh) plug;
2624 ssh_gotdata(ssh, (unsigned char *)data, len);
2625 if (ssh->state == SSH_STATE_CLOSED) {
2626 ssh_do_close(ssh, TRUE);
2632 static void ssh_sent(Plug plug, int bufsize)
2634 Ssh ssh = (Ssh) plug;
2636 * If the send backlog on the SSH socket itself clears, we
2637 * should unthrottle the whole world if it was throttled.
2639 if (bufsize < SSH_MAX_BACKLOG)
2640 ssh_throttle_all(ssh, 0, bufsize);
2644 * Connect to specified host and port.
2645 * Returns an error message, or NULL on success.
2646 * Also places the canonical host name into `realhost'. It must be
2647 * freed by the caller.
2649 static const char *connect_to_host(Ssh ssh, char *host, int port,
2650 char **realhost, int nodelay, int keepalive)
2652 static const struct plug_function_table fn_table = {
2663 ssh->savedhost = snewn(1 + strlen(host), char);
2664 strcpy(ssh->savedhost, host);
2667 port = 22; /* default ssh port */
2668 ssh->savedport = port;
2673 logeventf(ssh, "Looking up host \"%s\"%s", host,
2674 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2675 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2676 addr = name_lookup(host, port, realhost, &ssh->cfg,
2677 ssh->cfg.addressfamily);
2678 if ((err = sk_addr_error(addr)) != NULL) {
2686 ssh->fn = &fn_table;
2687 ssh->s = new_connection(addr, *realhost, port,
2688 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2689 if ((err = sk_socket_error(ssh->s)) != NULL) {
2691 notify_remote_exit(ssh->frontend);
2699 * Throttle or unthrottle the SSH connection.
2701 static void ssh1_throttle(Ssh ssh, int adjust)
2703 int old_count = ssh->v1_throttle_count;
2704 ssh->v1_throttle_count += adjust;
2705 assert(ssh->v1_throttle_count >= 0);
2706 if (ssh->v1_throttle_count && !old_count) {
2707 ssh_set_frozen(ssh, 1);
2708 } else if (!ssh->v1_throttle_count && old_count) {
2709 ssh_set_frozen(ssh, 0);
2714 * Throttle or unthrottle _all_ local data streams (for when sends
2715 * on the SSH connection itself back up).
2717 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2720 struct ssh_channel *c;
2722 if (enable == ssh->throttled_all)
2724 ssh->throttled_all = enable;
2725 ssh->overall_bufsize = bufsize;
2728 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2730 case CHAN_MAINSESSION:
2732 * This is treated separately, outside the switch.
2736 x11_override_throttle(c->u.x11.s, enable);
2739 /* Agent channels require no buffer management. */
2742 pfd_override_throttle(c->u.pfd.s, enable);
2749 * Username and password input, abstracted off into routines
2750 * reusable in several places - even between SSH-1 and SSH-2.
2753 /* Set up a username or password input loop on a given buffer. */
2754 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2756 ssh->userpass_input_buffer = buffer;
2757 ssh->userpass_input_buflen = buflen;
2758 ssh->userpass_input_bufpos = 0;
2759 ssh->userpass_input_echo = echo;
2763 * Process some terminal data in the course of username/password
2764 * input. Returns >0 for success (line of input returned in
2765 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2766 * for inconclusive (keep waiting for more input please).
2768 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2773 switch (c = *in++) {
2776 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2777 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2782 if (ssh->userpass_input_bufpos > 0) {
2783 if (ssh->userpass_input_echo)
2784 c_write_str(ssh, "\b \b");
2785 ssh->userpass_input_bufpos--;
2790 while (ssh->userpass_input_bufpos > 0) {
2791 if (ssh->userpass_input_echo)
2792 c_write_str(ssh, "\b \b");
2793 ssh->userpass_input_bufpos--;
2802 * This simplistic check for printability is disabled
2803 * when we're doing password input, because some people
2804 * have control characters in their passwords.o
2806 if ((!ssh->userpass_input_echo ||
2807 (c >= ' ' && c <= '~') ||
2808 ((unsigned char) c >= 160))
2809 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2810 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2811 if (ssh->userpass_input_echo)
2812 c_write(ssh, &c, 1);
2820 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2822 Ssh ssh = (Ssh) sshv;
2824 ssh->agent_response = reply;
2825 ssh->agent_response_len = replylen;
2827 if (ssh->version == 1)
2828 do_ssh1_login(ssh, NULL, -1, NULL);
2830 do_ssh2_authconn(ssh, NULL, -1, NULL);
2833 static void ssh_dialog_callback(void *sshv, int ret)
2835 Ssh ssh = (Ssh) sshv;
2837 ssh->user_response = ret;
2839 if (ssh->version == 1)
2840 do_ssh1_login(ssh, NULL, -1, NULL);
2842 do_ssh2_transport(ssh, NULL, -1, NULL);
2845 * This may have unfrozen the SSH connection, so do a
2848 ssh_process_queued_incoming_data(ssh);
2851 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2853 struct ssh_channel *c = (struct ssh_channel *)cv;
2855 void *sentreply = reply;
2858 /* Fake SSH_AGENT_FAILURE. */
2859 sentreply = "\0\0\0\1\5";
2862 if (ssh->version == 2) {
2863 ssh2_add_channel_data(c, sentreply, replylen);
2866 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2867 PKT_INT, c->remoteid,
2870 PKT_DATA, sentreply, replylen,
2879 * Client-initiated disconnection. Send a DISCONNECT if `wire_reason'
2880 * non-NULL, otherwise just close the connection. `client_reason' == NULL
2881 * => log `wire_reason'.
2883 static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason,
2884 int code, int clean_exit)
2888 client_reason = wire_reason;
2890 error = dupprintf("Disconnected: %s", client_reason);
2892 error = dupstr("Disconnected");
2894 if (ssh->version == 1) {
2895 send_packet(ssh, SSH1_MSG_DISCONNECT, PKT_STR, wire_reason,
2897 } else if (ssh->version == 2) {
2898 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2899 ssh2_pkt_adduint32(pktout, code);
2900 ssh2_pkt_addstring(pktout, wire_reason);
2901 ssh2_pkt_addstring(pktout, "en"); /* language tag */
2902 ssh2_pkt_send_noqueue(ssh, pktout);
2905 ssh->close_expected = TRUE;
2906 ssh->clean_exit = clean_exit;
2907 ssh_closing((Plug)ssh, error, 0, 0);
2912 * Handle the key exchange and user authentication phases.
2914 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2915 struct Packet *pktin)
2918 unsigned char cookie[8], *ptr;
2919 struct RSAKey servkey, hostkey;
2920 struct MD5Context md5c;
2921 struct do_ssh1_login_state {
2923 unsigned char *rsabuf, *keystr1, *keystr2;
2924 unsigned long supported_ciphers_mask, supported_auths_mask;
2925 int tried_publickey, tried_agent;
2926 int tis_auth_refused, ccard_auth_refused;
2927 unsigned char session_id[16];
2930 void *publickey_blob;
2931 int publickey_bloblen;
2937 unsigned char request[5], *response, *p;
2947 crState(do_ssh1_login_state);
2949 crBegin(ssh->do_ssh1_login_crstate);
2954 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2955 bombout(("Public key packet not received"));
2959 logevent("Received public keys");
2961 ptr = ssh_pkt_getdata(pktin, 8);
2963 bombout(("SSH-1 public key packet stopped before random cookie"));
2966 memcpy(cookie, ptr, 8);
2968 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2969 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2970 bombout(("Failed to read SSH-1 public keys from public key packet"));
2975 * Log the host key fingerprint.
2979 logevent("Host key fingerprint is:");
2980 strcpy(logmsg, " ");
2981 hostkey.comment = NULL;
2982 rsa_fingerprint(logmsg + strlen(logmsg),
2983 sizeof(logmsg) - strlen(logmsg), &hostkey);
2987 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2988 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2989 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2991 ssh->v1_local_protoflags =
2992 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2993 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2996 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2997 MD5Update(&md5c, s->keystr1, servkey.bytes);
2998 MD5Update(&md5c, cookie, 8);
2999 MD5Final(s->session_id, &md5c);
3001 for (i = 0; i < 32; i++)
3002 ssh->session_key[i] = random_byte();
3005 * Verify that the `bits' and `bytes' parameters match.
3007 if (hostkey.bits > hostkey.bytes * 8 ||
3008 servkey.bits > servkey.bytes * 8) {
3009 bombout(("SSH-1 public keys were badly formatted"));
3013 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
3015 s->rsabuf = snewn(s->len, unsigned char);
3018 * Verify the host key.
3022 * First format the key into a string.
3024 int len = rsastr_len(&hostkey);
3025 char fingerprint[100];
3026 char *keystr = snewn(len, char);
3027 rsastr_fmt(keystr, &hostkey);
3028 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
3030 ssh_set_frozen(ssh, 1);
3031 s->dlgret = verify_ssh_host_key(ssh->frontend,
3032 ssh->savedhost, ssh->savedport,
3033 "rsa", keystr, fingerprint,
3034 ssh_dialog_callback, ssh);
3036 if (s->dlgret < 0) {
3040 bombout(("Unexpected data from server while waiting"
3041 " for user host key response"));
3044 } while (pktin || inlen > 0);
3045 s->dlgret = ssh->user_response;
3047 ssh_set_frozen(ssh, 0);
3049 if (s->dlgret == 0) {
3050 ssh_disconnect(ssh, "User aborted at host key verification",
3056 for (i = 0; i < 32; i++) {
3057 s->rsabuf[i] = ssh->session_key[i];
3059 s->rsabuf[i] ^= s->session_id[i];
3062 if (hostkey.bytes > servkey.bytes) {
3063 ret = rsaencrypt(s->rsabuf, 32, &servkey);
3065 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
3067 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
3069 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
3072 bombout(("SSH-1 public key encryptions failed due to bad formatting"));
3076 logevent("Encrypted session key");
3079 int cipher_chosen = 0, warn = 0;
3080 char *cipher_string = NULL;
3082 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
3083 int next_cipher = ssh->cfg.ssh_cipherlist[i];
3084 if (next_cipher == CIPHER_WARN) {
3085 /* If/when we choose a cipher, warn about it */
3087 } else if (next_cipher == CIPHER_AES) {
3088 /* XXX Probably don't need to mention this. */
3089 logevent("AES not supported in SSH-1, skipping");
3091 switch (next_cipher) {
3092 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
3093 cipher_string = "3DES"; break;
3094 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
3095 cipher_string = "Blowfish"; break;
3096 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
3097 cipher_string = "single-DES"; break;
3099 if (s->supported_ciphers_mask & (1 << s->cipher_type))
3103 if (!cipher_chosen) {
3104 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
3105 bombout(("Server violates SSH-1 protocol by not "
3106 "supporting 3DES encryption"));
3108 /* shouldn't happen */
3109 bombout(("No supported ciphers found"));
3113 /* Warn about chosen cipher if necessary. */
3115 ssh_set_frozen(ssh, 1);
3116 s->dlgret = askalg(ssh->frontend, "cipher", cipher_string,
3117 ssh_dialog_callback, ssh);
3118 if (s->dlgret < 0) {
3122 bombout(("Unexpected data from server while waiting"
3123 " for user response"));
3126 } while (pktin || inlen > 0);
3127 s->dlgret = ssh->user_response;
3129 ssh_set_frozen(ssh, 0);
3130 if (s->dlgret == 0) {
3131 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
3138 switch (s->cipher_type) {
3139 case SSH_CIPHER_3DES:
3140 logevent("Using 3DES encryption");
3142 case SSH_CIPHER_DES:
3143 logevent("Using single-DES encryption");
3145 case SSH_CIPHER_BLOWFISH:
3146 logevent("Using Blowfish encryption");
3150 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
3151 PKT_CHAR, s->cipher_type,
3152 PKT_DATA, cookie, 8,
3153 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
3154 PKT_DATA, s->rsabuf, s->len,
3155 PKT_INT, ssh->v1_local_protoflags, PKT_END);
3157 logevent("Trying to enable encryption...");
3161 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
3162 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
3164 ssh->v1_cipher_ctx = ssh->cipher->make_context();
3165 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
3166 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
3168 ssh->crcda_ctx = crcda_make_context();
3169 logevent("Installing CRC compensation attack detector");
3171 if (servkey.modulus) {
3172 sfree(servkey.modulus);
3173 servkey.modulus = NULL;
3175 if (servkey.exponent) {
3176 sfree(servkey.exponent);
3177 servkey.exponent = NULL;
3179 if (hostkey.modulus) {
3180 sfree(hostkey.modulus);
3181 hostkey.modulus = NULL;
3183 if (hostkey.exponent) {
3184 sfree(hostkey.exponent);
3185 hostkey.exponent = NULL;
3189 if (pktin->type != SSH1_SMSG_SUCCESS) {
3190 bombout(("Encryption not successfully enabled"));
3194 logevent("Successfully started encryption");
3198 if (!*ssh->cfg.username) {
3199 if (ssh_get_line && !ssh_getline_pw_only) {
3200 if (!ssh_get_line("login as: ",
3201 s->username, sizeof(s->username), FALSE)) {
3203 * get_line failed to get a username.
3206 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
3210 int ret; /* need not be kept over crReturn */
3211 c_write_str(ssh, "login as: ");
3214 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
3216 crWaitUntil(!pktin);
3217 ret = process_userpass_input(ssh, in, inlen);
3221 c_write_str(ssh, "\r\n");
3224 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
3225 s->username[sizeof(s->username)-1] = '\0';
3228 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
3230 char userlog[22 + sizeof(s->username)];
3231 sprintf(userlog, "Sent username \"%s\"", s->username);
3233 if (flags & FLAG_INTERACTIVE &&
3234 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
3235 strcat(userlog, "\r\n");
3236 c_write_str(ssh, userlog);
3243 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
3244 /* We must not attempt PK auth. Pretend we've already tried it. */
3245 s->tried_publickey = s->tried_agent = 1;
3247 s->tried_publickey = s->tried_agent = 0;
3249 s->tis_auth_refused = s->ccard_auth_refused = 0;
3250 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
3251 if (!filename_is_null(ssh->cfg.keyfile)) {
3252 if (!rsakey_pubblob(&ssh->cfg.keyfile,
3253 &s->publickey_blob, &s->publickey_bloblen, NULL))
3254 s->publickey_blob = NULL;
3256 s->publickey_blob = NULL;
3258 while (pktin->type == SSH1_SMSG_FAILURE) {
3259 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
3261 if (agent_exists() && !s->tried_agent) {
3263 * Attempt RSA authentication using Pageant.
3269 logevent("Pageant is running. Requesting keys.");
3271 /* Request the keys held by the agent. */
3272 PUT_32BIT(s->request, 1);
3273 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
3274 if (!agent_query(s->request, 5, &r, &s->responselen,
3275 ssh_agent_callback, ssh)) {
3279 bombout(("Unexpected data from server while waiting"
3280 " for agent response"));
3283 } while (pktin || inlen > 0);
3284 r = ssh->agent_response;
3285 s->responselen = ssh->agent_response_len;
3287 s->response = (unsigned char *) r;
3288 if (s->response && s->responselen >= 5 &&
3289 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3290 s->p = s->response + 5;
3291 s->nkeys = GET_32BIT(s->p);
3293 logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys);
3294 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3295 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
3296 if (s->publickey_blob &&
3297 !memcmp(s->p, s->publickey_blob,
3298 s->publickey_bloblen)) {
3299 logevent("This key matches configured key file");
3300 s->tried_publickey = 1;
3305 do { /* do while (0) to make breaking easy */
3306 n = ssh1_read_bignum
3307 (s->p, s->responselen-(s->p-s->response),
3312 n = ssh1_read_bignum
3313 (s->p, s->responselen-(s->p-s->response),
3318 if (s->responselen - (s->p-s->response) < 4)
3320 s->commentlen = GET_32BIT(s->p);
3322 if (s->responselen - (s->p-s->response) <
3325 s->commentp = (char *)s->p;
3326 s->p += s->commentlen;
3330 logevent("Pageant key list packet was truncated");
3334 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3335 PKT_BIGNUM, s->key.modulus, PKT_END);
3337 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3338 logevent("Key refused");
3341 logevent("Received RSA challenge");
3342 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3343 bombout(("Server's RSA challenge was badly formatted"));
3348 char *agentreq, *q, *ret;
3351 len = 1 + 4; /* message type, bit count */
3352 len += ssh1_bignum_length(s->key.exponent);
3353 len += ssh1_bignum_length(s->key.modulus);
3354 len += ssh1_bignum_length(s->challenge);
3355 len += 16; /* session id */
3356 len += 4; /* response format */
3357 agentreq = snewn(4 + len, char);
3358 PUT_32BIT(agentreq, len);
3360 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3361 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3363 q += ssh1_write_bignum(q, s->key.exponent);
3364 q += ssh1_write_bignum(q, s->key.modulus);
3365 q += ssh1_write_bignum(q, s->challenge);
3366 memcpy(q, s->session_id, 16);
3368 PUT_32BIT(q, 1); /* response format */
3369 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3370 ssh_agent_callback, ssh)) {
3375 bombout(("Unexpected data from server"
3376 " while waiting for agent"
3380 } while (pktin || inlen > 0);
3381 vret = ssh->agent_response;
3382 retlen = ssh->agent_response_len;
3387 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3388 logevent("Sending Pageant's response");
3389 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3390 PKT_DATA, ret + 5, 16,
3394 if (pktin->type == SSH1_SMSG_SUCCESS) {
3396 ("Pageant's response accepted");
3397 if (flags & FLAG_VERBOSE) {
3398 c_write_str(ssh, "Authenticated using"
3400 c_write(ssh, s->commentp,
3402 c_write_str(ssh, "\" from agent\r\n");
3407 ("Pageant's response not accepted");
3410 ("Pageant failed to answer challenge");
3414 logevent("No reply received from Pageant");
3417 freebn(s->key.exponent);
3418 freebn(s->key.modulus);
3419 freebn(s->challenge);
3428 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3429 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3431 if (ssh->cfg.try_tis_auth &&
3432 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3433 !s->tis_auth_refused) {
3434 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3435 logevent("Requested TIS authentication");
3436 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3438 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3439 logevent("TIS authentication declined");
3440 if (flags & FLAG_INTERACTIVE)
3441 c_write_str(ssh, "TIS authentication refused.\r\n");
3442 s->tis_auth_refused = 1;
3448 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3450 bombout(("TIS challenge packet was badly formed"));
3453 c_write_str(ssh, "Using TIS authentication.\r\n");
3454 logevent("Received TIS challenge");
3455 if (challengelen > sizeof(s->prompt) - 1)
3456 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3457 memcpy(s->prompt, challenge, challengelen);
3458 /* Prompt heuristic comes from OpenSSH */
3459 strncpy(s->prompt + challengelen,
3460 memchr(s->prompt, '\n', challengelen) ?
3461 "": "\r\nResponse: ",
3462 (sizeof s->prompt) - challengelen);
3463 s->prompt[(sizeof s->prompt) - 1] = '\0';
3466 if (ssh->cfg.try_tis_auth &&
3467 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3468 !s->ccard_auth_refused) {
3469 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3470 logevent("Requested CryptoCard authentication");
3471 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3473 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3474 logevent("CryptoCard authentication declined");
3475 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3476 s->ccard_auth_refused = 1;
3482 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3484 bombout(("CryptoCard challenge packet was badly formed"));
3487 c_write_str(ssh, "Using CryptoCard authentication.\r\n");
3488 logevent("Received CryptoCard challenge");
3489 if (challengelen > sizeof(s->prompt) - 1)
3490 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3491 memcpy(s->prompt, challenge, challengelen);
3492 strncpy(s->prompt + challengelen,
3493 memchr(s->prompt, '\n', challengelen) ?
3494 "" : "\r\nResponse: ",
3495 sizeof(s->prompt) - challengelen);
3496 s->prompt[sizeof(s->prompt) - 1] = '\0';
3499 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3500 sprintf(s->prompt, "%.90s@%.90s's password: ",
3501 s->username, ssh->savedhost);
3503 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3504 char *comment = NULL;
3506 if (flags & FLAG_VERBOSE)
3507 c_write_str(ssh, "Trying public key authentication.\r\n");
3508 logeventf(ssh, "Trying public key \"%s\"",
3509 filename_to_str(&ssh->cfg.keyfile));
3510 type = key_type(&ssh->cfg.keyfile);
3511 if (type != SSH_KEYTYPE_SSH1) {
3512 char *msg = dupprintf("Key is of wrong type (%s)",
3513 key_type_to_str(type));
3515 c_write_str(ssh, msg);
3516 c_write_str(ssh, "\r\n");
3518 s->tried_publickey = 1;
3521 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3522 if (flags & FLAG_VERBOSE)
3523 c_write_str(ssh, "No passphrase required.\r\n");
3526 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3531 * Show password prompt, having first obtained it via a TIS
3532 * or CryptoCard exchange if we're doing TIS or CryptoCard
3536 if (!ssh_get_line(s->prompt, s->password,
3537 sizeof(s->password), TRUE)) {
3539 * get_line failed to get a password (for example
3540 * because one was supplied on the command line
3541 * which has already failed to work). Terminate.
3543 ssh_disconnect(ssh, NULL, "Unable to authenticate", 0, FALSE);
3547 /* Prompt may have come from server. We've munged it a bit, so
3548 * we know it to be zero-terminated at least once. */
3549 int ret; /* need not be saved over crReturn */
3550 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3553 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3555 crWaitUntil(!pktin);
3556 ret = process_userpass_input(ssh, in, inlen);
3560 c_write_str(ssh, "\r\n");
3564 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3566 * Try public key authentication with the specified
3569 s->tried_publickey = 1;
3572 const char *error = NULL;
3573 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3576 c_write_str(ssh, "Couldn't load private key from ");
3577 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3578 c_write_str(ssh, " (");
3579 c_write_str(ssh, error);
3580 c_write_str(ssh, ").\r\n");
3581 continue; /* go and try password */
3584 c_write_str(ssh, "Wrong passphrase.\r\n");
3585 s->tried_publickey = 0;
3586 continue; /* try again */
3591 * Send a public key attempt.
3593 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3594 PKT_BIGNUM, s->key.modulus, PKT_END);
3597 if (pktin->type == SSH1_SMSG_FAILURE) {
3598 c_write_str(ssh, "Server refused our public key.\r\n");
3599 continue; /* go and try password */
3601 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3602 bombout(("Bizarre response to offer of public key"));
3608 unsigned char buffer[32];
3609 Bignum challenge, response;
3611 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3612 bombout(("Server's RSA challenge was badly formatted"));
3615 response = rsadecrypt(challenge, &s->key);
3616 freebn(s->key.private_exponent);/* burn the evidence */
3618 for (i = 0; i < 32; i++) {
3619 buffer[i] = bignum_byte(response, 31 - i);
3623 MD5Update(&md5c, buffer, 32);
3624 MD5Update(&md5c, s->session_id, 16);
3625 MD5Final(buffer, &md5c);
3627 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3628 PKT_DATA, buffer, 16, PKT_END);
3635 if (pktin->type == SSH1_SMSG_FAILURE) {
3636 if (flags & FLAG_VERBOSE)
3637 c_write_str(ssh, "Failed to authenticate with"
3638 " our public key.\r\n");
3639 continue; /* go and try password */
3640 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3641 bombout(("Bizarre response to RSA authentication response"));
3645 break; /* we're through! */
3647 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3649 * Defence against traffic analysis: we send a
3650 * whole bunch of packets containing strings of
3651 * different lengths. One of these strings is the
3652 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3653 * The others are all random data in
3654 * SSH1_MSG_IGNORE packets. This way a passive
3655 * listener can't tell which is the password, and
3656 * hence can't deduce the password length.
3658 * Anybody with a password length greater than 16
3659 * bytes is going to have enough entropy in their
3660 * password that a listener won't find it _that_
3661 * much help to know how long it is. So what we'll
3664 * - if password length < 16, we send 15 packets
3665 * containing string lengths 1 through 15
3667 * - otherwise, we let N be the nearest multiple
3668 * of 8 below the password length, and send 8
3669 * packets containing string lengths N through
3670 * N+7. This won't obscure the order of
3671 * magnitude of the password length, but it will
3672 * introduce a bit of extra uncertainty.
3674 * A few servers (the old 1.2.18 through 1.2.22)
3675 * can't deal with SSH1_MSG_IGNORE. For these
3676 * servers, we need an alternative defence. We make
3677 * use of the fact that the password is interpreted
3678 * as a C string: so we can append a NUL, then some
3681 * One server (a Cisco one) can deal with neither
3682 * SSH1_MSG_IGNORE _nor_ a padded password string.
3683 * For this server we are left with no defences
3684 * against password length sniffing.
3686 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3688 * The server can deal with SSH1_MSG_IGNORE, so
3689 * we can use the primary defence.
3691 int bottom, top, pwlen, i;
3694 pwlen = strlen(s->password);
3696 bottom = 0; /* zero length passwords are OK! :-) */
3699 bottom = pwlen & ~7;
3703 assert(pwlen >= bottom && pwlen <= top);
3705 randomstr = snewn(top + 1, char);
3707 for (i = bottom; i <= top; i++) {
3709 defer_packet(ssh, s->pwpkt_type,
3710 PKTT_PASSWORD, PKT_STR, s->password,
3711 PKTT_OTHER, PKT_END);
3713 for (j = 0; j < i; j++) {
3715 randomstr[j] = random_byte();
3716 } while (randomstr[j] == '\0');
3718 randomstr[i] = '\0';
3719 defer_packet(ssh, SSH1_MSG_IGNORE,
3720 PKT_STR, randomstr, PKT_END);
3723 logevent("Sending password with camouflage packets");
3724 ssh_pkt_defersend(ssh);
3727 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3729 * The server can't deal with SSH1_MSG_IGNORE
3730 * but can deal with padded passwords, so we
3731 * can use the secondary defence.
3737 len = strlen(s->password);
3738 if (len < sizeof(string)) {
3740 strcpy(string, s->password);
3741 len++; /* cover the zero byte */
3742 while (len < sizeof(string)) {
3743 string[len++] = (char) random_byte();
3748 logevent("Sending length-padded password");
3749 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3750 PKT_INT, len, PKT_DATA, ss, len,
3751 PKTT_OTHER, PKT_END);
3754 * The server has _both_
3755 * BUG_CHOKES_ON_SSH1_IGNORE and
3756 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3757 * therefore nothing we can do.
3760 len = strlen(s->password);
3761 logevent("Sending unpadded password");
3762 send_packet(ssh, s->pwpkt_type,
3763 PKTT_PASSWORD, PKT_INT, len,
3764 PKT_DATA, s->password, len,
3765 PKTT_OTHER, PKT_END);
3768 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3769 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3772 logevent("Sent password");
3773 memset(s->password, 0, strlen(s->password));
3775 if (pktin->type == SSH1_SMSG_FAILURE) {
3776 if (flags & FLAG_VERBOSE)
3777 c_write_str(ssh, "Access denied\r\n");
3778 logevent("Authentication refused");
3779 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3780 bombout(("Strange packet received, type %d", pktin->type));
3785 logevent("Authentication successful");
3790 void sshfwd_close(struct ssh_channel *c)
3794 if (ssh->state == SSH_STATE_CLOSED)
3797 if (c && !c->closes) {
3799 * If halfopen is true, we have sent
3800 * CHANNEL_OPEN for this channel, but it hasn't even been
3801 * acknowledged by the server. So we must set a close flag
3802 * on it now, and then when the server acks the channel
3803 * open, we can close it then.
3806 if (ssh->version == 1) {
3807 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3810 struct Packet *pktout;
3811 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3812 ssh2_pkt_adduint32(pktout, c->remoteid);
3813 ssh2_pkt_send(ssh, pktout);
3816 c->closes = 1; /* sent MSG_CLOSE */
3817 if (c->type == CHAN_X11) {
3819 logevent("Forwarded X11 connection terminated");
3820 } else if (c->type == CHAN_SOCKDATA ||
3821 c->type == CHAN_SOCKDATA_DORMANT) {
3823 logevent("Forwarded port closed");
3828 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3832 if (ssh->state == SSH_STATE_CLOSED)
3835 if (ssh->version == 1) {
3836 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3837 PKT_INT, c->remoteid,
3839 PKT_INT, len, PKT_DATA, buf, len,
3840 PKTT_OTHER, PKT_END);
3842 * In SSH-1 we can return 0 here - implying that forwarded
3843 * connections are never individually throttled - because
3844 * the only circumstance that can cause throttling will be
3845 * the whole SSH connection backing up, in which case
3846 * _everything_ will be throttled as a whole.
3850 ssh2_add_channel_data(c, buf, len);
3851 return ssh2_try_send(c);
3855 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3859 if (ssh->state == SSH_STATE_CLOSED)
3862 if (ssh->version == 1) {
3863 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3864 c->v.v1.throttling = 0;
3865 ssh1_throttle(ssh, -1);
3868 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3872 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3874 struct queued_handler *qh = ssh->qhead;
3878 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3881 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3882 ssh->packet_dispatch[qh->msg1] = NULL;
3885 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3886 ssh->packet_dispatch[qh->msg2] = NULL;
3890 ssh->qhead = qh->next;
3892 if (ssh->qhead->msg1 > 0) {
3893 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3894 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3896 if (ssh->qhead->msg2 > 0) {
3897 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3898 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3901 ssh->qhead = ssh->qtail = NULL;
3902 ssh->packet_dispatch[pktin->type] = NULL;
3905 qh->handler(ssh, pktin, qh->ctx);
3910 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3911 chandler_fn_t handler, void *ctx)
3913 struct queued_handler *qh;
3915 qh = snew(struct queued_handler);
3918 qh->handler = handler;
3922 if (ssh->qtail == NULL) {
3926 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3927 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3930 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3931 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3934 ssh->qtail->next = qh;
3939 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3941 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3943 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3944 SSH2_MSG_REQUEST_SUCCESS)) {
3945 logeventf(ssh, "Remote port forwarding from %s enabled",
3948 logeventf(ssh, "Remote port forwarding from %s refused",
3951 rpf = del234(ssh->rportfwds, pf);
3957 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3959 const char *portfwd_strptr = cfg->portfwd;
3960 struct ssh_portfwd *epf;
3963 if (!ssh->portfwds) {
3964 ssh->portfwds = newtree234(ssh_portcmp);
3967 * Go through the existing port forwardings and tag them
3968 * with status==DESTROY. Any that we want to keep will be
3969 * re-enabled (status==KEEP) as we go through the
3970 * configuration and find out which bits are the same as
3973 struct ssh_portfwd *epf;
3975 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3976 epf->status = DESTROY;
3979 while (*portfwd_strptr) {
3980 char address_family, type;
3981 int sport,dport,sserv,dserv;
3982 char sports[256], dports[256], saddr[256], host[256];
3985 address_family = 'A';
3987 if (*portfwd_strptr == 'A' ||
3988 *portfwd_strptr == '4' ||
3989 *portfwd_strptr == '6')
3990 address_family = *portfwd_strptr++;
3991 if (*portfwd_strptr == 'L' ||
3992 *portfwd_strptr == 'R' ||
3993 *portfwd_strptr == 'D')
3994 type = *portfwd_strptr++;
3999 while (*portfwd_strptr && *portfwd_strptr != '\t') {
4000 if (*portfwd_strptr == ':') {
4002 * We've seen a colon in the middle of the
4003 * source port number. This means that
4004 * everything we've seen until now is the
4005 * source _address_, so we'll move it into
4006 * saddr and start sports from the beginning
4011 if (ssh->version == 1 && type == 'R') {
4012 logeventf(ssh, "SSH-1 cannot handle remote source address "
4013 "spec \"%s\"; ignoring", sports);
4015 strcpy(saddr, sports);
4018 if (n < lenof(sports)-1) sports[n++] = *portfwd_strptr++;
4022 if (*portfwd_strptr == '\t')
4025 while (*portfwd_strptr && *portfwd_strptr != ':') {
4026 if (n < lenof(host)-1) host[n++] = *portfwd_strptr++;
4029 if (*portfwd_strptr == ':')
4032 while (*portfwd_strptr) {
4033 if (n < lenof(dports)-1) dports[n++] = *portfwd_strptr++;
4037 dport = atoi(dports);
4041 dport = net_service_lookup(dports);
4043 logeventf(ssh, "Service lookup failed for destination"
4044 " port \"%s\"", dports);
4048 while (*portfwd_strptr) portfwd_strptr++;
4052 portfwd_strptr++; /* eat the NUL and move to next one */
4054 sport = atoi(sports);
4058 sport = net_service_lookup(sports);
4060 logeventf(ssh, "Service lookup failed for source"
4061 " port \"%s\"", sports);
4064 if (sport && dport) {
4065 /* Set up a description of the source port. */
4066 struct ssh_portfwd *pfrec, *epfrec;
4068 pfrec = snew(struct ssh_portfwd);
4070 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
4071 pfrec->sserv = sserv ? dupstr(sports) : NULL;
4072 pfrec->sport = sport;
4073 pfrec->daddr = *host ? dupstr(host) : NULL;
4074 pfrec->dserv = dserv ? dupstr(dports) : NULL;
4075 pfrec->dport = dport;
4076 pfrec->local = NULL;
4077 pfrec->remote = NULL;
4078 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
4079 address_family == '6' ? ADDRTYPE_IPV6 :
4082 epfrec = add234(ssh->portfwds, pfrec);
4083 if (epfrec != pfrec) {
4085 * We already have a port forwarding with precisely
4086 * these parameters. Hence, no need to do anything;
4087 * simply tag the existing one as KEEP.
4089 epfrec->status = KEEP;
4090 free_portfwd(pfrec);
4092 pfrec->status = CREATE;
4098 * Now go through and destroy any port forwardings which were
4101 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4102 if (epf->status == DESTROY) {
4105 message = dupprintf("%s port forwarding from %s%s%d",
4106 epf->type == 'L' ? "local" :
4107 epf->type == 'R' ? "remote" : "dynamic",
4108 epf->saddr ? epf->saddr : "",
4109 epf->saddr ? ":" : "",
4112 if (epf->type != 'D') {
4113 char *msg2 = dupprintf("%s to %s:%d", message,
4114 epf->daddr, epf->dport);
4119 logeventf(ssh, "Cancelling %s", message);
4123 struct ssh_rportfwd *rpf = epf->remote;
4124 struct Packet *pktout;
4127 * Cancel the port forwarding at the server
4130 if (ssh->version == 1) {
4132 * We cannot cancel listening ports on the
4133 * server side in SSH-1! There's no message
4134 * to support it. Instead, we simply remove
4135 * the rportfwd record from the local end
4136 * so that any connections the server tries
4137 * to make on it are rejected.
4140 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4141 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
4142 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
4144 ssh2_pkt_addstring(pktout, epf->saddr);
4145 } else if (ssh->cfg.rport_acceptall) {
4146 /* XXX: ssh->cfg.rport_acceptall may not represent
4147 * what was used to open the original connection,
4148 * since it's reconfigurable. */
4149 ssh2_pkt_addstring(pktout, "0.0.0.0");
4151 ssh2_pkt_addstring(pktout, "127.0.0.1");
4153 ssh2_pkt_adduint32(pktout, epf->sport);
4154 ssh2_pkt_send(ssh, pktout);
4157 del234(ssh->rportfwds, rpf);
4159 } else if (epf->local) {
4160 pfd_terminate(epf->local);
4163 delpos234(ssh->portfwds, i);
4165 i--; /* so we don't skip one in the list */
4169 * And finally, set up any new port forwardings (status==CREATE).
4171 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
4172 if (epf->status == CREATE) {
4173 char *sportdesc, *dportdesc;
4174 sportdesc = dupprintf("%s%s%s%s%d%s",
4175 epf->saddr ? epf->saddr : "",
4176 epf->saddr ? ":" : "",
4177 epf->sserv ? epf->sserv : "",
4178 epf->sserv ? "(" : "",
4180 epf->sserv ? ")" : "");
4181 if (epf->type == 'D') {
4184 dportdesc = dupprintf("%s:%s%s%d%s",
4186 epf->dserv ? epf->dserv : "",
4187 epf->dserv ? "(" : "",
4189 epf->dserv ? ")" : "");
4192 if (epf->type == 'L') {
4193 const char *err = pfd_addforward(epf->daddr, epf->dport,
4194 epf->saddr, epf->sport,
4197 epf->addressfamily);
4199 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
4200 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4201 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4202 sportdesc, dportdesc,
4203 err ? " failed: " : "", err ? err : "");
4204 } else if (epf->type == 'D') {
4205 const char *err = pfd_addforward(NULL, -1,
4206 epf->saddr, epf->sport,
4209 epf->addressfamily);
4211 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
4212 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
4213 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
4215 err ? " failed: " : "", err ? err : "");
4217 struct ssh_rportfwd *pf;
4220 * Ensure the remote port forwardings tree exists.
4222 if (!ssh->rportfwds) {
4223 if (ssh->version == 1)
4224 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
4226 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
4229 pf = snew(struct ssh_rportfwd);
4230 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
4231 pf->dhost[lenof(pf->dhost)-1] = '\0';
4232 pf->dport = epf->dport;
4233 pf->sport = epf->sport;
4234 if (add234(ssh->rportfwds, pf) != pf) {
4235 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
4236 epf->daddr, epf->dport);
4239 logeventf(ssh, "Requesting remote port %s"
4240 " forward to %s", sportdesc, dportdesc);
4242 pf->sportdesc = sportdesc;
4247 if (ssh->version == 1) {
4248 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
4249 PKT_INT, epf->sport,
4250 PKT_STR, epf->daddr,
4251 PKT_INT, epf->dport,
4253 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
4255 ssh_rportfwd_succfail, pf);
4257 struct Packet *pktout;
4258 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4259 ssh2_pkt_addstring(pktout, "tcpip-forward");
4260 ssh2_pkt_addbool(pktout, 1);/* want reply */
4262 ssh2_pkt_addstring(pktout, epf->saddr);
4263 } else if (cfg->rport_acceptall) {
4264 ssh2_pkt_addstring(pktout, "0.0.0.0");
4266 ssh2_pkt_addstring(pktout, "127.0.0.1");
4268 ssh2_pkt_adduint32(pktout, epf->sport);
4269 ssh2_pkt_send(ssh, pktout);
4271 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4272 SSH2_MSG_REQUEST_FAILURE,
4273 ssh_rportfwd_succfail, pf);
4282 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4285 int stringlen, bufsize;
4287 ssh_pkt_getstring(pktin, &string, &stringlen);
4288 if (string == NULL) {
4289 bombout(("Incoming terminal data packet was badly formed"));
4293 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4295 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4296 ssh->v1_stdout_throttling = 1;
4297 ssh1_throttle(ssh, +1);
4301 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4303 /* Remote side is trying to open a channel to talk to our
4304 * X-Server. Give them back a local channel number. */
4305 struct ssh_channel *c;
4306 int remoteid = ssh_pkt_getuint32(pktin);
4308 logevent("Received X11 connect request");
4309 /* Refuse if X11 forwarding is disabled. */
4310 if (!ssh->X11_fwd_enabled) {
4311 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4312 PKT_INT, remoteid, PKT_END);
4313 logevent("Rejected X11 connect request");
4315 c = snew(struct ssh_channel);
4318 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4319 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4320 logevent("Opening X11 forward connection failed");
4322 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4323 PKT_INT, remoteid, PKT_END);
4326 ("Opening X11 forward connection succeeded");
4327 c->remoteid = remoteid;
4328 c->halfopen = FALSE;
4329 c->localid = alloc_channel_id(ssh);
4331 c->v.v1.throttling = 0;
4332 c->type = CHAN_X11; /* identify channel type */
4333 add234(ssh->channels, c);
4334 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4335 PKT_INT, c->remoteid, PKT_INT,
4336 c->localid, PKT_END);
4337 logevent("Opened X11 forward channel");
4342 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4344 /* Remote side is trying to open a channel to talk to our
4345 * agent. Give them back a local channel number. */
4346 struct ssh_channel *c;
4347 int remoteid = ssh_pkt_getuint32(pktin);
4349 /* Refuse if agent forwarding is disabled. */
4350 if (!ssh->agentfwd_enabled) {
4351 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4352 PKT_INT, remoteid, PKT_END);
4354 c = snew(struct ssh_channel);
4356 c->remoteid = remoteid;
4357 c->halfopen = FALSE;
4358 c->localid = alloc_channel_id(ssh);
4360 c->v.v1.throttling = 0;
4361 c->type = CHAN_AGENT; /* identify channel type */
4362 c->u.a.lensofar = 0;
4363 add234(ssh->channels, c);
4364 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4365 PKT_INT, c->remoteid, PKT_INT, c->localid,
4370 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4372 /* Remote side is trying to open a channel to talk to a
4373 * forwarded port. Give them back a local channel number. */
4374 struct ssh_channel *c;
4375 struct ssh_rportfwd pf, *pfp;
4380 c = snew(struct ssh_channel);
4383 remoteid = ssh_pkt_getuint32(pktin);
4384 ssh_pkt_getstring(pktin, &host, &hostsize);
4385 port = ssh_pkt_getuint32(pktin);
4387 if (hostsize >= lenof(pf.dhost))
4388 hostsize = lenof(pf.dhost)-1;
4389 memcpy(pf.dhost, host, hostsize);
4390 pf.dhost[hostsize] = '\0';
4392 pfp = find234(ssh->rportfwds, &pf, NULL);
4395 logeventf(ssh, "Rejected remote port open request for %s:%d",
4397 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4398 PKT_INT, remoteid, PKT_END);
4400 logeventf(ssh, "Received remote port open request for %s:%d",
4402 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4403 c, &ssh->cfg, pfp->pfrec->addressfamily);
4405 logeventf(ssh, "Port open failed: %s", e);
4407 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4408 PKT_INT, remoteid, PKT_END);
4410 c->remoteid = remoteid;
4411 c->halfopen = FALSE;
4412 c->localid = alloc_channel_id(ssh);
4414 c->v.v1.throttling = 0;
4415 c->type = CHAN_SOCKDATA; /* identify channel type */
4416 add234(ssh->channels, c);
4417 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4418 PKT_INT, c->remoteid, PKT_INT,
4419 c->localid, PKT_END);
4420 logevent("Forwarded port opened successfully");
4425 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4427 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4428 unsigned int localid = ssh_pkt_getuint32(pktin);
4429 struct ssh_channel *c;
4431 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4432 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4433 c->remoteid = localid;
4434 c->halfopen = FALSE;
4435 c->type = CHAN_SOCKDATA;
4436 c->v.v1.throttling = 0;
4437 pfd_confirm(c->u.pfd.s);
4440 if (c && c->closes) {
4442 * We have a pending close on this channel,
4443 * which we decided on before the server acked
4444 * the channel open. So now we know the
4445 * remoteid, we can close it again.
4447 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4448 PKT_INT, c->remoteid, PKT_END);
4452 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4454 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4455 struct ssh_channel *c;
4457 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4458 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4459 logevent("Forwarded connection refused by server");
4460 pfd_close(c->u.pfd.s);
4461 del234(ssh->channels, c);
4466 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4468 /* Remote side closes a channel. */
4469 unsigned i = ssh_pkt_getuint32(pktin);
4470 struct ssh_channel *c;
4471 c = find234(ssh->channels, &i, ssh_channelfind);
4472 if (c && !c->halfopen) {
4475 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4477 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4478 logevent("Forwarded X11 connection terminated");
4479 assert(c->u.x11.s != NULL);
4480 x11_close(c->u.x11.s);
4483 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4484 logevent("Forwarded port closed");
4485 assert(c->u.pfd.s != NULL);
4486 pfd_close(c->u.pfd.s);
4490 c->closes |= (closetype << 2); /* seen this message */
4491 if (!(c->closes & closetype)) {
4492 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4494 c->closes |= closetype; /* sent it too */
4497 if (c->closes == 15) {
4498 del234(ssh->channels, c);
4502 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4503 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4504 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4509 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4511 /* Data sent down one of our channels. */
4512 int i = ssh_pkt_getuint32(pktin);
4515 struct ssh_channel *c;
4517 ssh_pkt_getstring(pktin, &p, &len);
4519 c = find234(ssh->channels, &i, ssh_channelfind);
4524 bufsize = x11_send(c->u.x11.s, p, len);
4527 bufsize = pfd_send(c->u.pfd.s, p, len);
4530 /* Data for an agent message. Buffer it. */
4532 if (c->u.a.lensofar < 4) {
4533 unsigned int l = min(4 - c->u.a.lensofar, len);
4534 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4538 c->u.a.lensofar += l;
4540 if (c->u.a.lensofar == 4) {
4542 4 + GET_32BIT(c->u.a.msglen);
4543 c->u.a.message = snewn(c->u.a.totallen,
4545 memcpy(c->u.a.message, c->u.a.msglen, 4);
4547 if (c->u.a.lensofar >= 4 && len > 0) {
4549 min(c->u.a.totallen - c->u.a.lensofar,
4551 memcpy(c->u.a.message + c->u.a.lensofar, p,
4555 c->u.a.lensofar += l;
4557 if (c->u.a.lensofar == c->u.a.totallen) {
4560 if (agent_query(c->u.a.message,
4563 ssh_agentf_callback, c))
4564 ssh_agentf_callback(c, reply, replylen);
4565 sfree(c->u.a.message);
4566 c->u.a.lensofar = 0;
4569 bufsize = 0; /* agent channels never back up */
4572 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4573 c->v.v1.throttling = 1;
4574 ssh1_throttle(ssh, +1);
4579 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4581 ssh->exitcode = ssh_pkt_getuint32(pktin);
4582 logeventf(ssh, "Server sent command exit status %d", ssh->exitcode);
4583 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4585 * In case `helpful' firewalls or proxies tack
4586 * extra human-readable text on the end of the
4587 * session which we might mistake for another
4588 * encrypted packet, we close the session once
4589 * we've sent EXIT_CONFIRMATION.
4591 ssh_disconnect(ssh, NULL, NULL, 0, TRUE);
4594 /* Helper function to deal with sending tty modes for REQUEST_PTY */
4595 static void ssh1_send_ttymode(void *data, char *mode, char *val)
4597 struct Packet *pktout = (struct Packet *)data;
4599 unsigned int arg = 0;
4600 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
4601 if (i == lenof(ssh_ttymodes)) return;
4602 switch (ssh_ttymodes[i].type) {
4604 arg = ssh_tty_parse_specchar(val);
4607 arg = ssh_tty_parse_boolean(val);
4610 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
4611 ssh2_pkt_addbyte(pktout, arg);
4615 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4616 struct Packet *pktin)
4618 crBegin(ssh->do_ssh1_connection_crstate);
4620 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4621 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4622 ssh1_smsg_stdout_stderr_data;
4624 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4625 ssh1_msg_channel_open_confirmation;
4626 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4627 ssh1_msg_channel_open_failure;
4628 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4629 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4630 ssh1_msg_channel_close;
4631 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4632 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4634 if (ssh->cfg.agentfwd && agent_exists()) {
4635 logevent("Requesting agent forwarding");
4636 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4640 if (pktin->type != SSH1_SMSG_SUCCESS
4641 && pktin->type != SSH1_SMSG_FAILURE) {
4642 bombout(("Protocol confusion"));
4644 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4645 logevent("Agent forwarding refused");
4647 logevent("Agent forwarding enabled");
4648 ssh->agentfwd_enabled = TRUE;
4649 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4653 if (ssh->cfg.x11_forward) {
4654 char proto[20], data[64];
4655 logevent("Requesting X11 forwarding");
4656 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4657 data, sizeof(data), ssh->cfg.x11_auth);
4658 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4660 * Note that while we blank the X authentication data here, we don't
4661 * take any special action to blank the start of an X11 channel,
4662 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
4663 * without having session blanking enabled is likely to leak your
4664 * cookie into the log.
4666 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4667 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4669 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER,
4670 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4673 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4675 PKTT_PASSWORD, PKT_STR, data, PKTT_OTHER, PKT_END);
4680 if (pktin->type != SSH1_SMSG_SUCCESS
4681 && pktin->type != SSH1_SMSG_FAILURE) {
4682 bombout(("Protocol confusion"));
4684 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4685 logevent("X11 forwarding refused");
4687 logevent("X11 forwarding enabled");
4688 ssh->X11_fwd_enabled = TRUE;
4689 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4693 ssh_setup_portfwd(ssh, &ssh->cfg);
4694 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4696 if (!ssh->cfg.nopty) {
4698 /* Unpick the terminal-speed string. */
4699 /* XXX perhaps we should allow no speeds to be sent. */
4700 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4701 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4702 /* Send the pty request. */
4703 pkt = ssh1_pkt_init(SSH1_CMSG_REQUEST_PTY);
4704 ssh_pkt_addstring(pkt, ssh->cfg.termtype);
4705 ssh_pkt_adduint32(pkt, ssh->term_height);
4706 ssh_pkt_adduint32(pkt, ssh->term_width);
4707 ssh_pkt_adduint32(pkt, 0); /* width in pixels */
4708 ssh_pkt_adduint32(pkt, 0); /* height in pixels */
4709 parse_ttymodes(ssh, ssh->cfg.ttymodes,
4710 ssh1_send_ttymode, (void *)pkt);
4711 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_ISPEED);
4712 ssh_pkt_adduint32(pkt, ssh->ispeed);
4713 ssh_pkt_addbyte(pkt, SSH1_TTY_OP_OSPEED);
4714 ssh_pkt_adduint32(pkt, ssh->ospeed);
4715 ssh_pkt_addbyte(pkt, SSH_TTY_OP_END);
4717 ssh->state = SSH_STATE_INTERMED;
4721 if (pktin->type != SSH1_SMSG_SUCCESS
4722 && pktin->type != SSH1_SMSG_FAILURE) {
4723 bombout(("Protocol confusion"));
4725 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4726 c_write_str(ssh, "Server refused to allocate pty\r\n");
4727 ssh->editing = ssh->echoing = 1;
4729 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4730 ssh->ospeed, ssh->ispeed);
4732 ssh->editing = ssh->echoing = 1;
4735 if (ssh->cfg.compression) {
4736 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4740 if (pktin->type != SSH1_SMSG_SUCCESS
4741 && pktin->type != SSH1_SMSG_FAILURE) {
4742 bombout(("Protocol confusion"));
4744 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4745 c_write_str(ssh, "Server refused to compress\r\n");
4747 logevent("Started compression");
4748 ssh->v1_compressing = TRUE;
4749 ssh->cs_comp_ctx = zlib_compress_init();
4750 logevent("Initialised zlib (RFC1950) compression");
4751 ssh->sc_comp_ctx = zlib_decompress_init();
4752 logevent("Initialised zlib (RFC1950) decompression");
4756 * Start the shell or command.
4758 * Special case: if the first-choice command is an SSH-2
4759 * subsystem (hence not usable here) and the second choice
4760 * exists, we fall straight back to that.
4763 char *cmd = ssh->cfg.remote_cmd_ptr;
4765 if (!cmd) cmd = ssh->cfg.remote_cmd;
4767 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4768 cmd = ssh->cfg.remote_cmd_ptr2;
4769 ssh->fallback_cmd = TRUE;
4772 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4774 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4775 logevent("Started session");
4778 ssh->state = SSH_STATE_SESSION;
4779 if (ssh->size_needed)
4780 ssh_size(ssh, ssh->term_width, ssh->term_height);
4781 if (ssh->eof_needed)
4782 ssh_special(ssh, TS_EOF);
4785 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4787 ssh->channels = newtree234(ssh_channelcmp);
4791 * By this point, most incoming packets are already being
4792 * handled by the dispatch table, and we need only pay
4793 * attention to the unusual ones.
4798 if (pktin->type == SSH1_SMSG_SUCCESS) {
4799 /* may be from EXEC_SHELL on some servers */
4800 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4801 /* may be from EXEC_SHELL on some servers
4802 * if no pty is available or in other odd cases. Ignore */
4804 bombout(("Strange packet received: type %d", pktin->type));
4809 int len = min(inlen, 512);
4810 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4811 PKT_INT, len, PKT_DATA, in, len,
4812 PKTT_OTHER, PKT_END);
4823 * Handle the top-level SSH-2 protocol.
4825 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4830 ssh_pkt_getstring(pktin, &msg, &msglen);
4831 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
4834 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4836 /* log reason code in disconnect message */
4840 ssh_pkt_getstring(pktin, &msg, &msglen);
4841 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4844 static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4846 /* Do nothing, because we're ignoring it! Duhh. */
4849 static void ssh1_protocol_setup(Ssh ssh)
4854 * Most messages are handled by the coroutines.
4856 for (i = 0; i < 256; i++)
4857 ssh->packet_dispatch[i] = NULL;
4860 * These special message types we install handlers for.
4862 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4863 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4864 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4867 static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
4868 struct Packet *pktin)
4870 unsigned char *in=(unsigned char*)vin;
4871 if (ssh->state == SSH_STATE_CLOSED)
4874 if (pktin && ssh->packet_dispatch[pktin->type]) {
4875 ssh->packet_dispatch[pktin->type](ssh, pktin);
4879 if (!ssh->protocol_initial_phase_done) {
4880 if (do_ssh1_login(ssh, in, inlen, pktin))
4881 ssh->protocol_initial_phase_done = TRUE;
4886 do_ssh1_connection(ssh, in, inlen, pktin);
4890 * Utility routine for decoding comma-separated strings in KEXINIT.
4892 static int in_commasep_string(char *needle, char *haystack, int haylen)
4895 if (!needle || !haystack) /* protect against null pointers */
4897 needlen = strlen(needle);
4900 * Is it at the start of the string?
4902 if (haylen >= needlen && /* haystack is long enough */
4903 !memcmp(needle, haystack, needlen) && /* initial match */
4904 (haylen == needlen || haystack[needlen] == ',')
4905 /* either , or EOS follows */
4909 * If not, search for the next comma and resume after that.
4910 * If no comma found, terminate.
4912 while (haylen > 0 && *haystack != ',')
4913 haylen--, haystack++;
4916 haylen--, haystack++; /* skip over comma itself */
4921 * Similar routine for checking whether we have the first string in a list.
4923 static int first_in_commasep_string(char *needle, char *haystack, int haylen)
4926 if (!needle || !haystack) /* protect against null pointers */
4928 needlen = strlen(needle);
4930 * Is it at the start of the string?
4932 if (haylen >= needlen && /* haystack is long enough */
4933 !memcmp(needle, haystack, needlen) && /* initial match */
4934 (haylen == needlen || haystack[needlen] == ',')
4935 /* either , or EOS follows */
4943 * SSH-2 key creation method.
4945 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4946 unsigned char *sessid, char chr,
4947 unsigned char *keyspace)
4950 /* First 20 bytes. */
4952 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4954 SHA_Bytes(&s, H, 20);
4955 SHA_Bytes(&s, &chr, 1);
4956 SHA_Bytes(&s, sessid, 20);
4957 SHA_Final(&s, keyspace);
4958 /* Next 20 bytes. */
4960 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4962 SHA_Bytes(&s, H, 20);
4963 SHA_Bytes(&s, keyspace, 20);
4964 SHA_Final(&s, keyspace + 20);
4968 * Handle the SSH-2 transport layer.
4970 static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
4971 struct Packet *pktin)
4973 unsigned char *in = (unsigned char *)vin;
4974 struct do_ssh2_transport_state {
4975 int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher;
4976 Bignum p, g, e, f, K;
4977 int kex_init_value, kex_reply_value;
4978 const struct ssh_mac **maclist;
4980 const struct ssh2_cipher *cscipher_tobe;
4981 const struct ssh2_cipher *sccipher_tobe;
4982 const struct ssh_mac *csmac_tobe;
4983 const struct ssh_mac *scmac_tobe;
4984 const struct ssh_compress *cscomp_tobe;
4985 const struct ssh_compress *sccomp_tobe;
4986 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4987 int hostkeylen, siglen;
4988 void *hkey; /* actual host key */
4989 unsigned char exchange_hash[20];
4990 int n_preferred_kex;
4991 const struct ssh_kex *preferred_kex[KEX_MAX];
4992 int n_preferred_ciphers;
4993 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4994 const struct ssh_compress *preferred_comp;
4995 int got_session_id, activated_authconn;
4996 struct Packet *pktout;
5001 crState(do_ssh2_transport_state);
5003 crBegin(ssh->do_ssh2_transport_crstate);
5005 s->cscipher_tobe = s->sccipher_tobe = NULL;
5006 s->csmac_tobe = s->scmac_tobe = NULL;
5007 s->cscomp_tobe = s->sccomp_tobe = NULL;
5009 s->got_session_id = s->activated_authconn = FALSE;
5012 * Be prepared to work around the buggy MAC problem.
5014 if (ssh->remote_bugs & BUG_SSH2_HMAC)
5015 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
5017 s->maclist = macs, s->nmacs = lenof(macs);
5020 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
5022 int i, j, commalist_started;
5025 * Set up the preferred key exchange. (NULL => warn below here)
5027 s->n_preferred_kex = 0;
5028 for (i = 0; i < KEX_MAX; i++) {
5029 switch (ssh->cfg.ssh_kexlist[i]) {
5031 s->preferred_kex[s->n_preferred_kex++] =
5032 &ssh_diffiehellman_gex;
5035 s->preferred_kex[s->n_preferred_kex++] =
5036 &ssh_diffiehellman_group14;
5039 s->preferred_kex[s->n_preferred_kex++] =
5040 &ssh_diffiehellman_group1;
5043 /* Flag for later. Don't bother if it's the last in
5045 if (i < KEX_MAX - 1) {
5046 s->preferred_kex[s->n_preferred_kex++] = NULL;
5053 * Set up the preferred ciphers. (NULL => warn below here)
5055 s->n_preferred_ciphers = 0;
5056 for (i = 0; i < CIPHER_MAX; i++) {
5057 switch (ssh->cfg.ssh_cipherlist[i]) {
5058 case CIPHER_BLOWFISH:
5059 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
5062 if (ssh->cfg.ssh2_des_cbc) {
5063 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
5067 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
5070 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
5072 case CIPHER_ARCFOUR:
5073 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour;
5076 /* Flag for later. Don't bother if it's the last in
5078 if (i < CIPHER_MAX - 1) {
5079 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
5086 * Set up preferred compression.
5088 if (ssh->cfg.compression)
5089 s->preferred_comp = &ssh_zlib;
5091 s->preferred_comp = &ssh_comp_none;
5094 * Enable queueing of outgoing auth- or connection-layer
5095 * packets while we are in the middle of a key exchange.
5097 ssh->queueing = TRUE;
5100 * Flag that KEX is in progress.
5102 ssh->kex_in_progress = TRUE;
5105 * Construct and send our key exchange packet.
5107 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
5108 for (i = 0; i < 16; i++)
5109 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
5110 /* List key exchange algorithms. */
5111 ssh2_pkt_addstring_start(s->pktout);
5112 commalist_started = 0;
5113 for (i = 0; i < s->n_preferred_kex; i++) {
5114 const struct ssh_kex *k = s->preferred_kex[i];
5115 if (!k) continue; /* warning flag */
5116 if (commalist_started)
5117 ssh2_pkt_addstring_str(s->pktout, ",");
5118 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
5119 commalist_started = 1;
5121 /* List server host key algorithms. */
5122 ssh2_pkt_addstring_start(s->pktout);
5123 for (i = 0; i < lenof(hostkey_algs); i++) {
5124 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
5125 if (i < lenof(hostkey_algs) - 1)
5126 ssh2_pkt_addstring_str(s->pktout, ",");
5128 /* List client->server encryption algorithms. */
5129 ssh2_pkt_addstring_start(s->pktout);
5130 commalist_started = 0;
5131 for (i = 0; i < s->n_preferred_ciphers; i++) {
5132 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5133 if (!c) continue; /* warning flag */
5134 for (j = 0; j < c->nciphers; j++) {
5135 if (commalist_started)
5136 ssh2_pkt_addstring_str(s->pktout, ",");
5137 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5138 commalist_started = 1;
5141 /* List server->client encryption algorithms. */
5142 ssh2_pkt_addstring_start(s->pktout);
5143 commalist_started = 0;
5144 for (i = 0; i < s->n_preferred_ciphers; i++) {
5145 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5146 if (!c) continue; /* warning flag */
5147 for (j = 0; j < c->nciphers; j++) {
5148 if (commalist_started)
5149 ssh2_pkt_addstring_str(s->pktout, ",");
5150 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
5151 commalist_started = 1;
5154 /* List client->server MAC algorithms. */
5155 ssh2_pkt_addstring_start(s->pktout);
5156 for (i = 0; i < s->nmacs; i++) {
5157 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
5158 if (i < s->nmacs - 1)
5159 ssh2_pkt_addstring_str(s->pktout, ",");
5161 /* List server->client 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 client->server compression algorithms. */
5169 ssh2_pkt_addstring_start(s->pktout);
5170 assert(lenof(compressions) > 1);
5171 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5172 for (i = 0; i < lenof(compressions); i++) {
5173 const struct ssh_compress *c = compressions[i];
5174 if (c != s->preferred_comp) {
5175 ssh2_pkt_addstring_str(s->pktout, ",");
5176 ssh2_pkt_addstring_str(s->pktout, c->name);
5179 /* List server->client compression algorithms. */
5180 ssh2_pkt_addstring_start(s->pktout);
5181 assert(lenof(compressions) > 1);
5182 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
5183 for (i = 0; i < lenof(compressions); i++) {
5184 const struct ssh_compress *c = compressions[i];
5185 if (c != s->preferred_comp) {
5186 ssh2_pkt_addstring_str(s->pktout, ",");
5187 ssh2_pkt_addstring_str(s->pktout, c->name);
5190 /* List client->server languages. Empty list. */
5191 ssh2_pkt_addstring_start(s->pktout);
5192 /* List server->client languages. Empty list. */
5193 ssh2_pkt_addstring_start(s->pktout);
5194 /* First KEX packet does _not_ follow, because we're not that brave. */
5195 ssh2_pkt_addbool(s->pktout, FALSE);
5197 ssh2_pkt_adduint32(s->pktout, 0);
5200 ssh->exhash = ssh->exhashbase;
5201 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
5203 ssh2_pkt_send_noqueue(ssh, s->pktout);
5207 if (pktin->length > 5)
5208 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
5211 * Now examine the other side's KEXINIT to see what we're up
5215 char *str, *preferred;
5218 if (pktin->type != SSH2_MSG_KEXINIT) {
5219 bombout(("expected key exchange packet from server"));
5223 ssh->hostkey = NULL;
5224 s->cscipher_tobe = NULL;
5225 s->sccipher_tobe = NULL;
5226 s->csmac_tobe = NULL;
5227 s->scmac_tobe = NULL;
5228 s->cscomp_tobe = NULL;
5229 s->sccomp_tobe = NULL;
5230 s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE;
5232 pktin->savedpos += 16; /* skip garbage cookie */
5233 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
5236 for (i = 0; i < s->n_preferred_kex; i++) {
5237 const struct ssh_kex *k = s->preferred_kex[i];
5241 if (!preferred) preferred = k->name;
5242 if (in_commasep_string(k->name, str, len))
5249 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
5250 str ? str : "(null)"));
5254 * Note that the server's guess is considered wrong if it doesn't match
5255 * the first algorithm in our list, even if it's still the algorithm
5258 s->guessok = first_in_commasep_string(preferred, str, len);
5259 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
5260 for (i = 0; i < lenof(hostkey_algs); i++) {
5261 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
5262 ssh->hostkey = hostkey_algs[i];
5266 s->guessok = s->guessok &&
5267 first_in_commasep_string(hostkey_algs[0]->name, str, len);
5268 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
5269 for (i = 0; i < s->n_preferred_ciphers; i++) {
5270 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5272 s->warn_cscipher = TRUE;
5274 for (j = 0; j < c->nciphers; j++) {
5275 if (in_commasep_string(c->list[j]->name, str, len)) {
5276 s->cscipher_tobe = c->list[j];
5281 if (s->cscipher_tobe)
5284 if (!s->cscipher_tobe) {
5285 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
5286 str ? str : "(null)"));
5290 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
5291 for (i = 0; i < s->n_preferred_ciphers; i++) {
5292 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
5294 s->warn_sccipher = TRUE;
5296 for (j = 0; j < c->nciphers; j++) {
5297 if (in_commasep_string(c->list[j]->name, str, len)) {
5298 s->sccipher_tobe = c->list[j];
5303 if (s->sccipher_tobe)
5306 if (!s->sccipher_tobe) {
5307 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
5308 str ? str : "(null)"));
5312 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
5313 for (i = 0; i < s->nmacs; i++) {
5314 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5315 s->csmac_tobe = s->maclist[i];
5319 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
5320 for (i = 0; i < s->nmacs; i++) {
5321 if (in_commasep_string(s->maclist[i]->name, str, len)) {
5322 s->scmac_tobe = s->maclist[i];
5326 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5327 for (i = 0; i < lenof(compressions) + 1; i++) {
5328 const struct ssh_compress *c =
5329 i == 0 ? s->preferred_comp : compressions[i - 1];
5330 if (in_commasep_string(c->name, str, len)) {
5335 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5336 for (i = 0; i < lenof(compressions) + 1; i++) {
5337 const struct ssh_compress *c =
5338 i == 0 ? s->preferred_comp : compressions[i - 1];
5339 if (in_commasep_string(c->name, str, len)) {
5344 ssh_pkt_getstring(pktin, &str, &len); /* client->server language */
5345 ssh_pkt_getstring(pktin, &str, &len); /* server->client language */
5346 s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok;
5349 ssh_set_frozen(ssh, 1);
5350 s->dlgret = askalg(ssh->frontend, "key-exchange algorithm",
5352 ssh_dialog_callback, ssh);
5353 if (s->dlgret < 0) {
5357 bombout(("Unexpected data from server while"
5358 " waiting for user response"));
5361 } while (pktin || inlen > 0);
5362 s->dlgret = ssh->user_response;
5364 ssh_set_frozen(ssh, 0);
5365 if (s->dlgret == 0) {
5366 ssh_disconnect(ssh, "User aborted at kex warning", NULL,
5372 if (s->warn_cscipher) {
5373 ssh_set_frozen(ssh, 1);
5374 s->dlgret = askalg(ssh->frontend,
5375 "client-to-server cipher",
5376 s->cscipher_tobe->name,
5377 ssh_dialog_callback, ssh);
5378 if (s->dlgret < 0) {
5382 bombout(("Unexpected data from server while"
5383 " waiting for user response"));
5386 } while (pktin || inlen > 0);
5387 s->dlgret = ssh->user_response;
5389 ssh_set_frozen(ssh, 0);
5390 if (s->dlgret == 0) {
5391 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5397 if (s->warn_sccipher) {
5398 ssh_set_frozen(ssh, 1);
5399 s->dlgret = askalg(ssh->frontend,
5400 "server-to-client cipher",
5401 s->sccipher_tobe->name,
5402 ssh_dialog_callback, ssh);
5403 if (s->dlgret < 0) {
5407 bombout(("Unexpected data from server while"
5408 " waiting for user response"));
5411 } while (pktin || inlen > 0);
5412 s->dlgret = ssh->user_response;
5414 ssh_set_frozen(ssh, 0);
5415 if (s->dlgret == 0) {
5416 ssh_disconnect(ssh, "User aborted at cipher warning", NULL,
5422 if (s->ignorepkt) /* first_kex_packet_follows */
5423 crWaitUntil(pktin); /* Ignore packet */
5427 * Work out the number of bits of key we will need from the key
5428 * exchange. We start with the maximum key length of either
5434 csbits = s->cscipher_tobe->keylen;
5435 scbits = s->sccipher_tobe->keylen;
5436 s->nbits = (csbits > scbits ? csbits : scbits);
5438 /* The keys only have 160-bit entropy, since they're based on
5439 * a SHA-1 hash. So cap the key size at 160 bits. */
5444 * If we're doing Diffie-Hellman group exchange, start by
5445 * requesting a group.
5447 if (!ssh->kex->pdata) {
5448 logevent("Doing Diffie-Hellman group exchange");
5449 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5451 * Work out how big a DH group we will need to allow that
5454 s->pbits = 512 << ((s->nbits - 1) / 64);
5455 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5456 ssh2_pkt_adduint32(s->pktout, s->pbits);
5457 ssh2_pkt_send_noqueue(ssh, s->pktout);
5460 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5461 bombout(("expected key exchange group packet from server"));
5464 s->p = ssh2_pkt_getmp(pktin);
5465 s->g = ssh2_pkt_getmp(pktin);
5466 if (!s->p || !s->g) {
5467 bombout(("unable to read mp-ints from incoming group packet"));
5470 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5471 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5472 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5474 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5475 ssh->kex_ctx = dh_setup_group(ssh->kex);
5476 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5477 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5478 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5479 ssh->kex->groupname);
5482 logevent("Doing Diffie-Hellman key exchange");
5484 * Now generate and send e for Diffie-Hellman.
5486 set_busy_status(ssh->frontend, BUSY_CPU); /* this can take a while */
5487 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5488 s->pktout = ssh2_pkt_init(s->kex_init_value);
5489 ssh2_pkt_addmp(s->pktout, s->e);
5490 ssh2_pkt_send_noqueue(ssh, s->pktout);
5492 set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */
5494 if (pktin->type != s->kex_reply_value) {
5495 bombout(("expected key exchange reply packet from server"));
5498 set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */
5499 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5500 s->f = ssh2_pkt_getmp(pktin);
5502 bombout(("unable to parse key exchange reply packet"));
5505 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5507 s->K = dh_find_K(ssh->kex_ctx, s->f);
5509 /* We assume everything from now on will be quick, and it might
5510 * involve user interaction. */
5511 set_busy_status(ssh->frontend, BUSY_NOT);
5513 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5514 if (ssh->kex == &ssh_diffiehellman_gex) {
5515 sha_uint32(&ssh->exhash, s->pbits);
5516 sha_mpint(&ssh->exhash, s->p);
5517 sha_mpint(&ssh->exhash, s->g);
5519 sha_mpint(&ssh->exhash, s->e);
5520 sha_mpint(&ssh->exhash, s->f);
5521 sha_mpint(&ssh->exhash, s->K);
5522 SHA_Final(&ssh->exhash, s->exchange_hash);
5524 dh_cleanup(ssh->kex_ctx);
5525 ssh->kex_ctx = NULL;
5528 debug(("Exchange hash is:\n"));
5529 dmemdump(s->exchange_hash, 20);
5532 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5534 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5535 (char *)s->exchange_hash, 20)) {
5536 bombout(("Server's host key did not match the signature supplied"));
5541 * Authenticate remote host: verify host key. (We've already
5542 * checked the signature of the exchange hash.)
5544 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5545 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5546 ssh_set_frozen(ssh, 1);
5547 s->dlgret = verify_ssh_host_key(ssh->frontend,
5548 ssh->savedhost, ssh->savedport,
5549 ssh->hostkey->keytype, s->keystr,
5551 ssh_dialog_callback, ssh);
5552 if (s->dlgret < 0) {
5556 bombout(("Unexpected data from server while waiting"
5557 " for user host key response"));
5560 } while (pktin || inlen > 0);
5561 s->dlgret = ssh->user_response;
5563 ssh_set_frozen(ssh, 0);
5564 if (s->dlgret == 0) {
5565 ssh_disconnect(ssh, "User aborted at host key verification", NULL,
5569 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5570 logevent("Host key fingerprint is:");
5571 logevent(s->fingerprint);
5573 sfree(s->fingerprint);
5575 ssh->hostkey->freekey(s->hkey);
5578 * The exchange hash from the very first key exchange is also
5579 * the session id, used in session key construction and
5582 if (!s->got_session_id) {
5583 memcpy(ssh->v2_session_id, s->exchange_hash,
5584 sizeof(s->exchange_hash));
5585 s->got_session_id = TRUE;
5589 * Send SSH2_MSG_NEWKEYS.
5591 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5592 ssh2_pkt_send_noqueue(ssh, s->pktout);
5593 ssh->outgoing_data_size = 0; /* start counting from here */
5596 * We've sent client NEWKEYS, so create and initialise
5597 * client-to-server session keys.
5599 if (ssh->cs_cipher_ctx)
5600 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5601 ssh->cscipher = s->cscipher_tobe;
5602 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5604 if (ssh->cs_mac_ctx)
5605 ssh->csmac->free_context(ssh->cs_mac_ctx);
5606 ssh->csmac = s->csmac_tobe;
5607 ssh->cs_mac_ctx = ssh->csmac->make_context();
5609 if (ssh->cs_comp_ctx)
5610 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5611 ssh->cscomp = s->cscomp_tobe;
5612 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5615 * Set IVs on client-to-server keys. Here we use the exchange
5616 * hash from the _first_ key exchange.
5619 unsigned char keyspace[40];
5620 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5621 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5622 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5623 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5624 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5625 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5628 logeventf(ssh, "Initialised %.200s client->server encryption",
5629 ssh->cscipher->text_name);
5630 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5631 ssh->csmac->text_name);
5632 if (ssh->cscomp->text_name)
5633 logeventf(ssh, "Initialised %s compression",
5634 ssh->cscomp->text_name);
5637 * Now our end of the key exchange is complete, we can send all
5638 * our queued higher-layer packets.
5640 ssh->queueing = FALSE;
5641 ssh2_pkt_queuesend(ssh);
5644 * Expect SSH2_MSG_NEWKEYS from server.
5647 if (pktin->type != SSH2_MSG_NEWKEYS) {
5648 bombout(("expected new-keys packet from server"));
5651 ssh->incoming_data_size = 0; /* start counting from here */
5654 * We've seen server NEWKEYS, so create and initialise
5655 * server-to-client session keys.
5657 if (ssh->sc_cipher_ctx)
5658 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5659 ssh->sccipher = s->sccipher_tobe;
5660 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5662 if (ssh->sc_mac_ctx)
5663 ssh->scmac->free_context(ssh->sc_mac_ctx);
5664 ssh->scmac = s->scmac_tobe;
5665 ssh->sc_mac_ctx = ssh->scmac->make_context();
5667 if (ssh->sc_comp_ctx)
5668 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5669 ssh->sccomp = s->sccomp_tobe;
5670 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5673 * Set IVs on server-to-client keys. Here we use the exchange
5674 * hash from the _first_ key exchange.
5677 unsigned char keyspace[40];
5678 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5679 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5680 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5681 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5682 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5683 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5685 logeventf(ssh, "Initialised %.200s server->client encryption",
5686 ssh->sccipher->text_name);
5687 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5688 ssh->scmac->text_name);
5689 if (ssh->sccomp->text_name)
5690 logeventf(ssh, "Initialised %s decompression",
5691 ssh->sccomp->text_name);
5694 * Free key exchange data.
5698 if (ssh->kex == &ssh_diffiehellman_gex) {
5704 * Key exchange is over. Loop straight back round if we have a
5705 * deferred rekey reason.
5707 if (ssh->deferred_rekey_reason) {
5708 logevent(ssh->deferred_rekey_reason);
5710 ssh->deferred_rekey_reason = NULL;
5711 goto begin_key_exchange;
5715 * Otherwise, schedule a timer for our next rekey.
5717 ssh->kex_in_progress = FALSE;
5718 ssh->last_rekey = GETTICKCOUNT();
5719 if (ssh->cfg.ssh_rekey_time != 0)
5720 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5724 * If this is the first key exchange phase, we must pass the
5725 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5726 * wants to see it but because it will need time to initialise
5727 * itself before it sees an actual packet. In subsequent key
5728 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5729 * it would only confuse the layer above.
5731 if (s->activated_authconn) {
5734 s->activated_authconn = TRUE;
5737 * Now we're encrypting. Begin returning 1 to the protocol main
5738 * function so that other things can run on top of the
5739 * transport. If we ever see a KEXINIT, we must go back to the
5742 * We _also_ go back to the start if we see pktin==NULL and
5743 * inlen==-1, because this is a special signal meaning
5744 * `initiate client-driven rekey', and `in' contains a message
5745 * giving the reason for the rekey.
5747 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5748 (!pktin && inlen == -1))) {
5753 logevent("Server initiated key re-exchange");
5756 * Special case: if the server bug is set that doesn't
5757 * allow rekeying, we give a different log message and
5758 * continue waiting. (If such a server _initiates_ a rekey,
5759 * we process it anyway!)
5761 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5762 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5764 /* Reset the counters, so that at least this message doesn't
5765 * hit the event log _too_ often. */
5766 ssh->outgoing_data_size = 0;
5767 ssh->incoming_data_size = 0;
5768 if (ssh->cfg.ssh_rekey_time != 0) {
5770 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5773 goto wait_for_rekey; /* this is utterly horrid */
5775 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5778 goto begin_key_exchange;
5784 * Add data to an SSH-2 channel output buffer.
5786 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5789 bufchain_add(&c->v.v2.outbuffer, buf, len);
5793 * Attempt to send data on an SSH-2 channel.
5795 static int ssh2_try_send(struct ssh_channel *c)
5798 struct Packet *pktout;
5800 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5803 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5804 if ((unsigned)len > c->v.v2.remwindow)
5805 len = c->v.v2.remwindow;
5806 if ((unsigned)len > c->v.v2.remmaxpkt)
5807 len = c->v.v2.remmaxpkt;
5808 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5809 ssh2_pkt_adduint32(pktout, c->remoteid);
5810 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5811 ssh2_pkt_addstring_start(pktout);
5812 ssh2_pkt_addstring_data(pktout, data, len);
5813 end_log_omission(ssh, pktout);
5814 ssh2_pkt_send(ssh, pktout);
5815 bufchain_consume(&c->v.v2.outbuffer, len);
5816 c->v.v2.remwindow -= len;
5820 * After having sent as much data as we can, return the amount
5823 return bufchain_size(&c->v.v2.outbuffer);
5826 static void ssh2_try_send_and_unthrottle(struct ssh_channel *c)
5830 return; /* don't send on closing channels */
5831 bufsize = ssh2_try_send(c);
5834 case CHAN_MAINSESSION:
5835 /* stdin need not receive an unthrottle
5836 * notification since it will be polled */
5839 x11_unthrottle(c->u.x11.s);
5842 /* agent sockets are request/response and need no
5843 * buffer management */
5846 pfd_unthrottle(c->u.pfd.s);
5853 * Potentially enlarge the window on an SSH-2 channel.
5855 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5860 * Never send WINDOW_ADJUST for a channel that the remote side
5861 * already thinks it's closed; there's no point, since it won't
5862 * be sending any more data anyway.
5868 * Only send a WINDOW_ADJUST if there's significantly more window
5869 * available than the other end thinks there is. This saves us
5870 * sending a WINDOW_ADJUST for every character in a shell session.
5872 * "Significant" is arbitrarily defined as half the window size.
5874 if (newwin > c->v.v2.locwindow * 2) {
5875 struct Packet *pktout;
5877 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5878 ssh2_pkt_adduint32(pktout, c->remoteid);
5879 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5880 ssh2_pkt_send(ssh, pktout);
5881 c->v.v2.locwindow = newwin;
5885 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5887 unsigned i = ssh_pkt_getuint32(pktin);
5888 struct ssh_channel *c;
5889 c = find234(ssh->channels, &i, ssh_channelfind);
5890 if (c && !c->closes) {
5891 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5892 ssh2_try_send_and_unthrottle(c);
5896 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5900 unsigned i = ssh_pkt_getuint32(pktin);
5901 struct ssh_channel *c;
5902 c = find234(ssh->channels, &i, ssh_channelfind);
5904 return; /* nonexistent channel */
5905 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5906 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5907 return; /* extended but not stderr */
5908 ssh_pkt_getstring(pktin, &data, &length);
5911 c->v.v2.locwindow -= length;
5913 case CHAN_MAINSESSION:
5915 from_backend(ssh->frontend, pktin->type ==
5916 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5920 bufsize = x11_send(c->u.x11.s, data, length);
5923 bufsize = pfd_send(c->u.pfd.s, data, length);
5926 while (length > 0) {
5927 if (c->u.a.lensofar < 4) {
5928 unsigned int l = min(4 - c->u.a.lensofar, length);
5929 memcpy(c->u.a.msglen + c->u.a.lensofar,
5933 c->u.a.lensofar += l;
5935 if (c->u.a.lensofar == 4) {
5937 4 + GET_32BIT(c->u.a.msglen);
5938 c->u.a.message = snewn(c->u.a.totallen,
5940 memcpy(c->u.a.message, c->u.a.msglen, 4);
5942 if (c->u.a.lensofar >= 4 && length > 0) {
5944 min(c->u.a.totallen - c->u.a.lensofar,
5946 memcpy(c->u.a.message + c->u.a.lensofar,
5950 c->u.a.lensofar += l;
5952 if (c->u.a.lensofar == c->u.a.totallen) {
5955 if (agent_query(c->u.a.message,
5958 ssh_agentf_callback, c))
5959 ssh_agentf_callback(c, reply, replylen);
5960 sfree(c->u.a.message);
5961 c->u.a.lensofar = 0;
5968 * If we are not buffering too much data,
5969 * enlarge the window again at the remote side.
5971 if (bufsize < OUR_V2_WINSIZE)
5972 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5976 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5978 unsigned i = ssh_pkt_getuint32(pktin);
5979 struct ssh_channel *c;
5981 c = find234(ssh->channels, &i, ssh_channelfind);
5983 return; /* nonexistent channel */
5985 if (c->type == CHAN_X11) {
5987 * Remote EOF on an X11 channel means we should
5988 * wrap up and close the channel ourselves.
5990 x11_close(c->u.x11.s);
5992 } else if (c->type == CHAN_AGENT) {
5994 } else if (c->type == CHAN_SOCKDATA) {
5995 pfd_close(c->u.pfd.s);
6000 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
6002 unsigned i = ssh_pkt_getuint32(pktin);
6003 struct ssh_channel *c;
6004 struct Packet *pktout;
6006 c = find234(ssh->channels, &i, ssh_channelfind);
6007 if (!c || c->halfopen) {
6008 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
6009 c ? "half-open" : "nonexistent", i));
6012 /* Do pre-close processing on the channel. */
6014 case CHAN_MAINSESSION:
6015 ssh->mainchan = NULL;
6016 update_specials_menu(ssh->frontend);
6019 if (c->u.x11.s != NULL)
6020 x11_close(c->u.x11.s);
6027 if (c->u.pfd.s != NULL)
6028 pfd_close(c->u.pfd.s);
6032 if (c->closes == 0) {
6033 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6034 ssh2_pkt_adduint32(pktout, c->remoteid);
6035 ssh2_pkt_send(ssh, pktout);
6037 del234(ssh->channels, c);
6038 bufchain_clear(&c->v.v2.outbuffer);
6042 * See if that was the last channel left open.
6043 * (This is only our termination condition if we're
6044 * not running in -N mode.)
6046 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
6048 * We used to send SSH_MSG_DISCONNECT here,
6049 * because I'd believed that _every_ conforming
6050 * SSH-2 connection had to end with a disconnect
6051 * being sent by at least one side; apparently
6052 * I was wrong and it's perfectly OK to
6053 * unceremoniously slam the connection shut
6054 * when you're done, and indeed OpenSSH feels
6055 * this is more polite than sending a
6056 * DISCONNECT. So now we don't.
6058 ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE);
6062 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
6064 unsigned i = ssh_pkt_getuint32(pktin);
6065 struct ssh_channel *c;
6066 struct Packet *pktout;
6068 c = find234(ssh->channels, &i, ssh_channelfind);
6070 return; /* nonexistent channel */
6071 if (c->type != CHAN_SOCKDATA_DORMANT)
6072 return; /* dunno why they're confirming this */
6073 c->remoteid = ssh_pkt_getuint32(pktin);
6074 c->halfopen = FALSE;
6075 c->type = CHAN_SOCKDATA;
6076 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6077 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6079 pfd_confirm(c->u.pfd.s);
6082 * We have a pending close on this channel,
6083 * which we decided on before the server acked
6084 * the channel open. So now we know the
6085 * remoteid, we can close it again.
6087 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
6088 ssh2_pkt_adduint32(pktout, c->remoteid);
6089 ssh2_pkt_send(ssh, pktout);
6093 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
6095 static const char *const reasons[] = {
6096 "<unknown reason code>",
6097 "Administratively prohibited",
6099 "Unknown channel type",
6100 "Resource shortage",
6102 unsigned i = ssh_pkt_getuint32(pktin);
6103 unsigned reason_code;
6104 char *reason_string;
6106 struct ssh_channel *c;
6107 c = find234(ssh->channels, &i, ssh_channelfind);
6109 return; /* nonexistent channel */
6110 if (c->type != CHAN_SOCKDATA_DORMANT)
6111 return; /* dunno why they're failing this */
6113 reason_code = ssh_pkt_getuint32(pktin);
6114 if (reason_code >= lenof(reasons))
6115 reason_code = 0; /* ensure reasons[reason_code] in range */
6116 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
6117 logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]",
6118 reasons[reason_code], reason_length, reason_string);
6120 pfd_close(c->u.pfd.s);
6122 del234(ssh->channels, c);
6126 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
6130 int typelen, want_reply;
6131 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
6132 struct ssh_channel *c;
6133 struct Packet *pktout;
6135 localid = ssh_pkt_getuint32(pktin);
6136 ssh_pkt_getstring(pktin, &type, &typelen);
6137 want_reply = ssh2_pkt_getbool(pktin);
6140 * First, check that the channel exists. Otherwise,
6141 * we can instantly disconnect with a rude message.
6143 c = find234(ssh->channels, &localid, ssh_channelfind);
6145 char *buf = dupprintf("Received channel request for nonexistent"
6146 " channel %d", localid);
6147 ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE);
6153 * Having got the channel number, we now look at
6154 * the request type string to see if it's something
6157 if (c == ssh->mainchan) {
6159 * We recognise "exit-status" and "exit-signal" on
6160 * the primary channel.
6162 if (typelen == 11 &&
6163 !memcmp(type, "exit-status", 11)) {
6165 ssh->exitcode = ssh_pkt_getuint32(pktin);
6166 logeventf(ssh, "Server sent command exit status %d",
6168 reply = SSH2_MSG_CHANNEL_SUCCESS;
6170 } else if (typelen == 11 &&
6171 !memcmp(type, "exit-signal", 11)) {
6173 int is_plausible = TRUE, is_int = FALSE;
6174 char *fmt_sig = "", *fmt_msg = "";
6176 int msglen = 0, core = FALSE;
6177 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
6178 * provide an `int' for the signal, despite its
6179 * having been a `string' in the drafts since at
6180 * least 2001. (Fixed in session.c 1.147.) Try to
6181 * infer which we can safely parse it as. */
6183 unsigned char *p = pktin->body +
6185 long len = pktin->length - pktin->savedpos;
6186 unsigned long num = GET_32BIT(p); /* what is it? */
6187 /* If it's 0, it hardly matters; assume string */
6191 int maybe_int = FALSE, maybe_str = FALSE;
6192 #define CHECK_HYPOTHESIS(offset, result) \
6195 if (q >= 0 && q+4 <= len) { \
6196 q = q + 4 + GET_32BIT(p+q); \
6197 if (q >= 0 && q+4 <= len && \
6198 ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
6202 CHECK_HYPOTHESIS(4+1, maybe_int);
6203 CHECK_HYPOTHESIS(4+num+1, maybe_str);
6204 #undef CHECK_HYPOTHESIS
6205 if (maybe_int && !maybe_str)
6207 else if (!maybe_int && maybe_str)
6210 /* Crikey. Either or neither. Panic. */
6211 is_plausible = FALSE;
6216 /* Old non-standard OpenSSH. */
6217 int signum = ssh_pkt_getuint32(pktin);
6218 fmt_sig = dupprintf(" %d", signum);
6220 /* As per the drafts. */
6223 ssh_pkt_getstring(pktin, &sig, &siglen);
6224 /* Signal name isn't supposed to be blank, but
6225 * let's cope gracefully if it is. */
6227 fmt_sig = dupprintf(" \"%.*s\"",
6231 core = ssh2_pkt_getbool(pktin);
6232 ssh_pkt_getstring(pktin, &msg, &msglen);
6234 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
6236 /* ignore lang tag */
6237 } /* else don't attempt to parse */
6238 logeventf(ssh, "Server exited on signal%s%s%s",
6239 fmt_sig, core ? " (core dumped)" : "",
6241 if (*fmt_sig) sfree(fmt_sig);
6242 if (*fmt_msg) sfree(fmt_msg);
6243 reply = SSH2_MSG_CHANNEL_SUCCESS;
6248 * This is a channel request we don't know
6249 * about, so we now either ignore the request
6250 * or respond with CHANNEL_FAILURE, depending
6253 reply = SSH2_MSG_CHANNEL_FAILURE;
6256 pktout = ssh2_pkt_init(reply);
6257 ssh2_pkt_adduint32(pktout, c->remoteid);
6258 ssh2_pkt_send(ssh, pktout);
6262 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
6265 int typelen, want_reply;
6266 struct Packet *pktout;
6268 ssh_pkt_getstring(pktin, &type, &typelen);
6269 want_reply = ssh2_pkt_getbool(pktin);
6272 * We currently don't support any global requests
6273 * at all, so we either ignore the request or
6274 * respond with REQUEST_FAILURE, depending on
6278 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
6279 ssh2_pkt_send(ssh, pktout);
6283 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
6291 struct ssh_channel *c;
6292 unsigned remid, winsize, pktsize;
6293 struct Packet *pktout;
6295 ssh_pkt_getstring(pktin, &type, &typelen);
6296 c = snew(struct ssh_channel);
6299 remid = ssh_pkt_getuint32(pktin);
6300 winsize = ssh_pkt_getuint32(pktin);
6301 pktsize = ssh_pkt_getuint32(pktin);
6303 if (typelen == 3 && !memcmp(type, "x11", 3)) {
6306 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6307 addrstr = snewn(peeraddrlen+1, char);
6308 memcpy(addrstr, peeraddr, peeraddrlen);
6309 addrstr[peeraddrlen] = '\0';
6310 peerport = ssh_pkt_getuint32(pktin);
6312 logeventf(ssh, "Received X11 connect request from %s:%d",
6315 if (!ssh->X11_fwd_enabled)
6316 error = "X11 forwarding is not enabled";
6317 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
6318 ssh->x11auth, addrstr, peerport,
6319 &ssh->cfg) != NULL) {
6320 error = "Unable to open an X11 connection";
6322 logevent("Opening X11 forward connection succeeded");
6327 } else if (typelen == 15 &&
6328 !memcmp(type, "forwarded-tcpip", 15)) {
6329 struct ssh_rportfwd pf, *realpf;
6332 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
6333 pf.sport = ssh_pkt_getuint32(pktin);
6334 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
6335 peerport = ssh_pkt_getuint32(pktin);
6336 realpf = find234(ssh->rportfwds, &pf, NULL);
6337 logeventf(ssh, "Received remote port %d open request "
6338 "from %s:%d", pf.sport, peeraddr, peerport);
6339 if (realpf == NULL) {
6340 error = "Remote port is not recognised";
6342 const char *e = pfd_newconnect(&c->u.pfd.s,
6346 realpf->pfrec->addressfamily);
6347 logeventf(ssh, "Attempting to forward remote port to "
6348 "%s:%d", realpf->dhost, realpf->dport);
6350 logeventf(ssh, "Port open failed: %s", e);
6351 error = "Port open failed";
6353 logevent("Forwarded port opened successfully");
6354 c->type = CHAN_SOCKDATA;
6357 } else if (typelen == 22 &&
6358 !memcmp(type, "auth-agent@openssh.com", 22)) {
6359 if (!ssh->agentfwd_enabled)
6360 error = "Agent forwarding is not enabled";
6362 c->type = CHAN_AGENT; /* identify channel type */
6363 c->u.a.lensofar = 0;
6366 error = "Unsupported channel type requested";
6369 c->remoteid = remid;
6370 c->halfopen = FALSE;
6372 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
6373 ssh2_pkt_adduint32(pktout, c->remoteid);
6374 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
6375 ssh2_pkt_addstring(pktout, error);
6376 ssh2_pkt_addstring(pktout, "en"); /* language tag */
6377 ssh2_pkt_send(ssh, pktout);
6378 logeventf(ssh, "Rejected channel open: %s", error);
6381 c->localid = alloc_channel_id(ssh);
6383 c->v.v2.locwindow = OUR_V2_WINSIZE;
6384 c->v.v2.remwindow = winsize;
6385 c->v.v2.remmaxpkt = pktsize;
6386 bufchain_init(&c->v.v2.outbuffer);
6387 add234(ssh->channels, c);
6388 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
6389 ssh2_pkt_adduint32(pktout, c->remoteid);
6390 ssh2_pkt_adduint32(pktout, c->localid);
6391 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
6392 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
6393 ssh2_pkt_send(ssh, pktout);
6398 * Buffer banner messages for later display at some convenient point.
6400 static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin)
6402 /* Arbitrary limit to prevent unbounded inflation of buffer */
6403 if (bufchain_size(&ssh->banner) <= 131072) {
6404 char *banner = NULL;
6406 ssh_pkt_getstring(pktin, &banner, &size);
6408 bufchain_add(&ssh->banner, banner, size);
6412 /* Helper function to deal with sending tty modes for "pty-req" */
6413 static void ssh2_send_ttymode(void *data, char *mode, char *val)
6415 struct Packet *pktout = (struct Packet *)data;
6417 unsigned int arg = 0;
6418 while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++;
6419 if (i == lenof(ssh_ttymodes)) return;
6420 switch (ssh_ttymodes[i].type) {
6422 arg = ssh_tty_parse_specchar(val);
6425 arg = ssh_tty_parse_boolean(val);
6428 ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode);
6429 ssh2_pkt_adduint32(pktout, arg);
6433 * Handle the SSH-2 userauth and connection layers.
6435 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
6436 struct Packet *pktin)
6438 struct do_ssh2_authconn_state {
6440 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
6442 AUTH_KEYBOARD_INTERACTIVE
6446 AUTH_TYPE_PUBLICKEY,
6447 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
6448 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
6450 AUTH_TYPE_KEYBOARD_INTERACTIVE,
6451 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
6453 int done_service_req;
6454 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
6455 int tried_pubkey_config, tried_agent;
6456 int kbd_inter_running, kbd_inter_refused;
6458 int num_prompts, curr_prompt, echo;
6463 void *publickey_blob;
6464 int publickey_bloblen;
6465 unsigned char request[5], *response, *p;
6469 char *pkblob, *alg, *commentp;
6470 int pklen, alglen, commentlen;
6471 int siglen, retlen, len;
6472 char *q, *agentreq, *ret;
6474 int num_env, env_left, env_ok;
6475 struct Packet *pktout;
6477 crState(do_ssh2_authconn_state);
6479 crBegin(ssh->do_ssh2_authconn_crstate);
6481 s->done_service_req = FALSE;
6482 s->we_are_in = FALSE;
6483 if (!ssh->cfg.ssh_no_userauth) {
6485 * Request userauth protocol, and await a response to it.
6487 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6488 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6489 ssh2_pkt_send(ssh, s->pktout);
6490 crWaitUntilV(pktin);
6491 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT)
6492 s->done_service_req = TRUE;
6494 if (!s->done_service_req) {
6496 * Request connection protocol directly, without authentication.
6498 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6499 ssh2_pkt_addstring(s->pktout, "ssh-connection");
6500 ssh2_pkt_send(ssh, s->pktout);
6501 crWaitUntilV(pktin);
6502 if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) {
6503 s->we_are_in = TRUE; /* no auth required */
6505 bombout(("Server refused service request"));
6511 * We repeat this whole loop, including the username prompt,
6512 * until we manage a successful authentication. If the user
6513 * types the wrong _password_, they can be sent back to the
6514 * beginning to try another username, if this is configured on.
6515 * (If they specify a username in the config, they are never
6516 * asked, even if they do give a wrong password.)
6518 * I think this best serves the needs of
6520 * - the people who have no configuration, no keys, and just
6521 * want to try repeated (username,password) pairs until they
6522 * type both correctly
6524 * - people who have keys and configuration but occasionally
6525 * need to fall back to passwords
6527 * - people with a key held in Pageant, who might not have
6528 * logged in to a particular machine before; so they want to
6529 * type a username, and then _either_ their key will be
6530 * accepted, _or_ they will type a password. If they mistype
6531 * the username they will want to be able to get back and
6534 s->username[0] = '\0';
6535 s->got_username = FALSE;
6536 bufchain_init(&ssh->banner);
6537 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] =
6538 ssh2_msg_userauth_banner;
6539 while (!s->we_are_in) {
6543 if (s->got_username && !ssh->cfg.change_username) {
6545 * We got a username last time round this loop, and
6546 * with change_username turned off we don't try to get
6549 } else if (!*ssh->cfg.username) {
6550 if (ssh_get_line && !ssh_getline_pw_only) {
6551 if (!ssh_get_line("login as: ",
6552 s->username, sizeof(s->username), FALSE)) {
6554 * get_line failed to get a username.
6557 ssh_disconnect(ssh, "No username provided", NULL, 0, TRUE);
6561 int ret; /* need not be saved across crReturn */
6562 c_write_str(ssh, "login as: ");
6564 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6566 crWaitUntilV(!pktin);
6567 ret = process_userpass_input(ssh, in, inlen);
6571 c_write_str(ssh, "\r\n");
6573 s->username[strcspn(s->username, "\n\r")] = '\0';
6576 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6577 s->username[sizeof(s->username)-1] = '\0';
6578 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6579 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6580 c_write_str(ssh, stuff);
6584 s->got_username = TRUE;
6587 * Send an authentication request using method "none": (a)
6588 * just in case it succeeds, and (b) so that we know what
6589 * authentication methods we can usefully try next.
6591 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6593 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6594 ssh2_pkt_addstring(s->pktout, s->username);
6595 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6596 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6597 ssh2_pkt_send(ssh, s->pktout);
6598 s->type = AUTH_TYPE_NONE;
6600 s->we_are_in = FALSE;
6602 s->tried_pubkey_config = FALSE;
6603 s->tried_agent = FALSE;
6604 s->kbd_inter_running = FALSE;
6605 s->kbd_inter_refused = FALSE;
6606 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6607 if (!filename_is_null(ssh->cfg.keyfile)) {
6609 logeventf(ssh, "Reading private key file \"%.150s\"",
6610 filename_to_str(&ssh->cfg.keyfile));
6611 keytype = key_type(&ssh->cfg.keyfile);
6612 if (keytype == SSH_KEYTYPE_SSH2) {
6614 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6615 &s->publickey_bloblen, NULL);
6618 logeventf(ssh, "Unable to use this key file (%s)",
6619 key_type_to_str(keytype));
6620 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6622 filename_to_str(&ssh->cfg.keyfile),
6623 key_type_to_str(keytype));
6624 c_write_str(ssh, msgbuf);
6626 s->publickey_blob = NULL;
6629 s->publickey_blob = NULL;
6633 * Wait for the result of the last authentication request.
6636 crWaitUntilV(pktin);
6638 * Now is a convenient point to spew any banner material
6639 * that we've accumulated. (This should ensure that when
6640 * we exit the auth loop, we haven't any left to deal
6644 int size = bufchain_size(&ssh->banner);
6646 * Don't show the banner if we're operating in
6647 * non-verbose non-interactive mode. (It's probably
6648 * a script, which means nobody will read the
6649 * banner _anyway_, and moreover the printing of
6650 * the banner will screw up processing on the
6651 * output of (say) plink.)
6653 if (size && (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE))) {
6654 char *banner = snewn(size, char);
6655 bufchain_fetch(&ssh->banner, banner, size);
6656 c_write_untrusted(ssh, banner, size);
6659 bufchain_clear(&ssh->banner);
6661 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6662 logevent("Access granted");
6663 s->we_are_in = TRUE;
6667 if (s->kbd_inter_running &&
6668 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6670 * This is either a further set-of-prompts packet
6671 * in keyboard-interactive authentication, or it's
6672 * the same one and we came back here with `gotit'
6673 * set. In the former case, we must reset the
6674 * curr_prompt variable.
6678 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6679 /* FIXME: perhaps we should support this? */
6680 bombout(("PASSWD_CHANGEREQ not yet supported"));
6682 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6683 bombout(("Strange packet received during authentication: type %d",
6691 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6692 * we can look at the string in it and know what we can
6693 * helpfully try next.
6695 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6698 ssh_pkt_getstring(pktin, &methods, &methlen);
6699 s->kbd_inter_running = FALSE;
6700 if (!ssh2_pkt_getbool(pktin)) {
6702 * We have received an unequivocal Access
6703 * Denied. This can translate to a variety of
6706 * - if we'd just tried "none" authentication,
6707 * it's not worth printing anything at all
6709 * - if we'd just tried a public key _offer_,
6710 * the message should be "Server refused our
6711 * key" (or no message at all if the key
6712 * came from Pageant)
6714 * - if we'd just tried anything else, the
6715 * message really should be "Access denied".
6717 * Additionally, if we'd just tried password
6718 * authentication, we should break out of this
6719 * whole loop so as to go back to the username
6720 * prompt (iff we're configured to allow
6721 * username change attempts).
6723 if (s->type == AUTH_TYPE_NONE) {
6725 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6726 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6727 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6728 c_write_str(ssh, "Server refused our key\r\n");
6729 logevent("Server refused public key");
6730 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6731 /* server declined keyboard-interactive; ignore */
6733 c_write_str(ssh, "Access denied\r\n");
6734 logevent("Access denied");
6735 if (s->type == AUTH_TYPE_PASSWORD &&
6736 ssh->cfg.change_username) {
6737 /* XXX perhaps we should allow
6738 * keyboard-interactive to do this too? */
6739 s->we_are_in = FALSE;
6744 c_write_str(ssh, "Further authentication required\r\n");
6745 logevent("Further authentication required");
6749 in_commasep_string("publickey", methods, methlen);
6751 in_commasep_string("password", methods, methlen);
6752 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6753 in_commasep_string("keyboard-interactive", methods, methlen);
6757 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6761 * Most password/passphrase prompts will be
6762 * non-echoing, so we set this to 0 by default.
6763 * Exception is that some keyboard-interactive prompts
6764 * can be echoing, in which case we'll set this to 1.
6768 if (!s->method && s->can_pubkey &&
6769 agent_exists() && !s->tried_agent) {
6771 * Attempt public-key authentication using Pageant.
6776 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6777 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6779 s->tried_agent = TRUE;
6781 logevent("Pageant is running. Requesting keys.");
6783 /* Request the keys held by the agent. */
6784 PUT_32BIT(s->request, 1);
6785 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6786 if (!agent_query(s->request, 5, &r, &s->responselen,
6787 ssh_agent_callback, ssh)) {
6791 bombout(("Unexpected data from server while"
6792 " waiting for agent response"));
6795 } while (pktin || inlen > 0);
6796 r = ssh->agent_response;
6797 s->responselen = ssh->agent_response_len;
6799 s->response = (unsigned char *) r;
6800 if (s->response && s->responselen >= 5 &&
6801 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6802 s->p = s->response + 5;
6803 s->nkeys = GET_32BIT(s->p);
6805 logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys);
6806 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6809 logeventf(ssh, "Trying Pageant key #%d", s->keyi);
6810 s->pklen = GET_32BIT(s->p);
6812 if (s->publickey_blob &&
6813 s->pklen == s->publickey_bloblen &&
6814 !memcmp(s->p, s->publickey_blob,
6815 s->publickey_bloblen)) {
6816 logevent("This key matches configured key file");
6817 s->tried_pubkey_config = 1;
6819 s->pkblob = (char *)s->p;
6821 s->alglen = GET_32BIT(s->pkblob);
6822 s->alg = s->pkblob + 4;
6823 s->commentlen = GET_32BIT(s->p);
6825 s->commentp = (char *)s->p;
6826 s->p += s->commentlen;
6827 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6828 ssh2_pkt_addstring(s->pktout, s->username);
6829 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6830 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6831 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6832 ssh2_pkt_addstring_start(s->pktout);
6833 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6834 ssh2_pkt_addstring_start(s->pktout);
6835 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6836 ssh2_pkt_send(ssh, s->pktout);
6838 crWaitUntilV(pktin);
6839 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6840 logevent("Key refused");
6844 if (flags & FLAG_VERBOSE) {
6845 c_write_str(ssh, "Authenticating with "
6847 c_write(ssh, s->commentp, s->commentlen);
6848 c_write_str(ssh, "\" from agent\r\n");
6852 * Server is willing to accept the key.
6853 * Construct a SIGN_REQUEST.
6855 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6856 ssh2_pkt_addstring(s->pktout, s->username);
6857 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6858 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6859 ssh2_pkt_addbool(s->pktout, TRUE);
6860 ssh2_pkt_addstring_start(s->pktout);
6861 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6862 ssh2_pkt_addstring_start(s->pktout);
6863 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6865 s->siglen = s->pktout->length - 5 + 4 + 20;
6866 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6868 s->len = 1; /* message type */
6869 s->len += 4 + s->pklen; /* key blob */
6870 s->len += 4 + s->siglen; /* data to sign */
6871 s->len += 4; /* flags */
6872 s->agentreq = snewn(4 + s->len, char);
6873 PUT_32BIT(s->agentreq, s->len);
6874 s->q = s->agentreq + 4;
6875 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6876 PUT_32BIT(s->q, s->pklen);
6878 memcpy(s->q, s->pkblob, s->pklen);
6880 PUT_32BIT(s->q, s->siglen);
6882 /* Now the data to be signed... */
6883 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6884 PUT_32BIT(s->q, 20);
6887 memcpy(s->q, ssh->v2_session_id, 20);
6889 memcpy(s->q, s->pktout->data + 5,
6890 s->pktout->length - 5);
6891 s->q += s->pktout->length - 5;
6892 /* And finally the (zero) flags word. */
6894 if (!agent_query(s->agentreq, s->len + 4,
6896 ssh_agent_callback, ssh)) {
6900 bombout(("Unexpected data from server"
6901 " while waiting for agent"
6905 } while (pktin || inlen > 0);
6906 vret = ssh->agent_response;
6907 s->retlen = ssh->agent_response_len;
6912 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6913 logevent("Sending Pageant's response");
6914 ssh2_add_sigblob(ssh, s->pktout,
6915 s->pkblob, s->pklen,
6917 GET_32BIT(s->ret + 5));
6918 ssh2_pkt_send(ssh, s->pktout);
6923 ("Pageant failed to answer challenge");
6934 if (!s->method && s->can_pubkey && s->publickey_blob
6935 && !s->tried_pubkey_config) {
6936 unsigned char *pub_blob;
6937 char *algorithm, *comment;
6940 s->tried_pubkey_config = TRUE;
6942 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6943 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6946 * Try the public key supplied in the configuration.
6948 * First, offer the public blob to see if the server is
6949 * willing to accept it.
6952 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6957 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6958 ssh2_pkt_addstring(s->pktout, s->username);
6959 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6960 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6961 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6962 ssh2_pkt_addstring(s->pktout, algorithm);
6963 ssh2_pkt_addstring_start(s->pktout);
6964 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6966 ssh2_pkt_send(ssh, s->pktout);
6967 logevent("Offered public key");
6969 crWaitUntilV(pktin);
6970 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6972 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6973 continue; /* key refused; give up on it */
6976 logevent("Offer of public key accepted");
6978 * Actually attempt a serious authentication using
6981 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6982 sprintf(s->pwprompt,
6983 "Passphrase for key \"%.100s\": ",
6989 if (flags & FLAG_VERBOSE) {
6990 c_write_str(ssh, "Authenticating with public key \"");
6991 c_write_str(ssh, comment);
6992 c_write_str(ssh, "\"\r\n");
6994 s->method = AUTH_PUBLICKEY_FILE;
6998 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6999 !s->kbd_inter_running) {
7000 s->method = AUTH_KEYBOARD_INTERACTIVE;
7001 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7003 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7004 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7006 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7007 ssh2_pkt_addstring(s->pktout, s->username);
7008 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7009 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
7010 ssh2_pkt_addstring(s->pktout, ""); /* lang */
7011 ssh2_pkt_addstring(s->pktout, "");
7012 ssh2_pkt_send(ssh, s->pktout);
7014 crWaitUntilV(pktin);
7015 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
7016 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
7018 logevent("Keyboard-interactive authentication refused");
7019 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
7020 s->kbd_inter_refused = TRUE; /* don't try it again */
7024 c_write_str(ssh, "Using keyboard-interactive authentication.\r\n");
7025 s->kbd_inter_running = TRUE;
7029 if (s->kbd_inter_running) {
7030 s->method = AUTH_KEYBOARD_INTERACTIVE;
7031 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7033 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7034 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
7036 if (s->curr_prompt == 0) {
7038 * We've got a fresh USERAUTH_INFO_REQUEST.
7039 * Display header data, and start going through
7042 char *name, *inst, *lang;
7043 int name_len, inst_len, lang_len;
7045 ssh_pkt_getstring(pktin, &name, &name_len);
7046 ssh_pkt_getstring(pktin, &inst, &inst_len);
7047 ssh_pkt_getstring(pktin, &lang, &lang_len);
7049 c_write_untrusted(ssh, name, name_len);
7050 c_write_str(ssh, "\r\n");
7053 c_write_untrusted(ssh, inst, inst_len);
7054 c_write_str(ssh, "\r\n");
7056 s->num_prompts = ssh_pkt_getuint32(pktin);
7060 * If there are prompts remaining in the packet,
7061 * display one and get a response.
7063 if (s->curr_prompt < s->num_prompts) {
7067 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
7068 if (prompt_len > 0) {
7069 static const char trunc[] = "<prompt truncated>: ";
7070 static const int prlen = sizeof(s->pwprompt) -
7072 if (prompt_len > prlen) {
7073 memcpy(s->pwprompt, prompt, prlen);
7074 strcpy(s->pwprompt + prlen, trunc);
7076 memcpy(s->pwprompt, prompt, prompt_len);
7077 s->pwprompt[prompt_len] = '\0';
7081 "<server failed to send prompt>: ");
7083 s->echo = ssh2_pkt_getbool(pktin);
7089 if (!s->method && s->can_passwd) {
7090 s->method = AUTH_PASSWORD;
7091 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
7092 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
7093 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
7100 if (!ssh_get_line(s->pwprompt, s->password,
7101 sizeof(s->password), TRUE)) {
7103 * get_line failed to get a password (for
7104 * example because one was supplied on the
7105 * command line which has already failed to
7108 ssh_disconnect(ssh, NULL, "Unable to authenticate",
7109 SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER,
7114 int ret; /* need not be saved across crReturn */
7115 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
7118 setup_userpass_input(ssh, s->password,
7119 sizeof(s->password), s->echo);
7121 crWaitUntilV(!pktin);
7122 ret = process_userpass_input(ssh, in, inlen);
7126 c_write_str(ssh, "\r\n");
7130 if (s->method == AUTH_PUBLICKEY_FILE) {
7132 * We have our passphrase. Now try the actual authentication.
7134 struct ssh2_userkey *key;
7135 const char *error = NULL;
7137 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
7139 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
7140 if (key == SSH2_WRONG_PASSPHRASE) {
7141 c_write_str(ssh, "Wrong passphrase\r\n");
7142 s->tried_pubkey_config = FALSE;
7144 c_write_str(ssh, "Unable to load private key (");
7145 c_write_str(ssh, error);
7146 c_write_str(ssh, ")\r\n");
7147 s->tried_pubkey_config = TRUE;
7149 /* Send a spurious AUTH_NONE to return to the top. */
7150 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7151 ssh2_pkt_addstring(s->pktout, s->username);
7152 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7153 ssh2_pkt_addstring(s->pktout, "none"); /* method */
7154 ssh2_pkt_send(ssh, s->pktout);
7155 s->type = AUTH_TYPE_NONE;
7157 unsigned char *pkblob, *sigblob, *sigdata;
7158 int pkblob_len, sigblob_len, sigdata_len;
7162 * We have loaded the private key and the server
7163 * has announced that it's willing to accept it.
7164 * Hallelujah. Generate a signature and send it.
7166 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7167 ssh2_pkt_addstring(s->pktout, s->username);
7168 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7169 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
7170 ssh2_pkt_addbool(s->pktout, TRUE);
7171 ssh2_pkt_addstring(s->pktout, key->alg->name);
7172 pkblob = key->alg->public_blob(key->data, &pkblob_len);
7173 ssh2_pkt_addstring_start(s->pktout);
7174 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
7177 * The data to be signed is:
7181 * followed by everything so far placed in the
7184 sigdata_len = s->pktout->length - 5 + 4 + 20;
7185 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
7187 sigdata = snewn(sigdata_len, unsigned char);
7189 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
7190 PUT_32BIT(sigdata+p, 20);
7193 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
7194 memcpy(sigdata+p, s->pktout->data + 5,
7195 s->pktout->length - 5);
7196 p += s->pktout->length - 5;
7197 assert(p == sigdata_len);
7198 sigblob = key->alg->sign(key->data, (char *)sigdata,
7199 sigdata_len, &sigblob_len);
7200 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
7201 sigblob, sigblob_len);
7206 ssh2_pkt_send(ssh, s->pktout);
7207 s->type = AUTH_TYPE_PUBLICKEY;
7208 key->alg->freekey(key->data);
7210 } else if (s->method == AUTH_PASSWORD) {
7212 * We pad out the password packet to 256 bytes to make
7213 * it harder for an attacker to find the length of the
7216 * Anyone using a password longer than 256 bytes
7217 * probably doesn't have much to worry about from
7218 * people who find out how long their password is!
7220 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
7221 s->pktout->forcepad = 256;
7222 ssh2_pkt_addstring(s->pktout, s->username);
7223 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
7224 ssh2_pkt_addstring(s->pktout, "password");
7225 ssh2_pkt_addbool(s->pktout, FALSE);
7226 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7227 ssh2_pkt_addstring(s->pktout, s->password);
7228 memset(s->password, 0, sizeof(s->password));
7229 end_log_omission(ssh, s->pktout);
7230 ssh2_pkt_send(ssh, s->pktout);
7231 logevent("Sent password");
7232 s->type = AUTH_TYPE_PASSWORD;
7233 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
7234 if (s->curr_prompt == 0) {
7235 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
7236 s->pktout->forcepad = 256;
7237 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
7239 if (s->need_pw) { /* only add pw if we just got one! */
7240 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7241 ssh2_pkt_addstring(s->pktout, s->password);
7242 memset(s->password, 0, sizeof(s->password));
7243 end_log_omission(ssh, s->pktout);
7246 if (s->curr_prompt >= s->num_prompts) {
7247 ssh2_pkt_send(ssh, s->pktout);
7250 * If there are prompts remaining, we set
7251 * `gotit' so that we won't attempt to get
7252 * another packet. Then we go back round the
7253 * loop and will end up retrieving another
7254 * prompt out of the existing packet. Funky or
7259 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
7261 ssh_disconnect(ssh, NULL,
7262 "No supported authentication methods available",
7263 SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE,
7269 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7272 * Now the connection protocol has started, one way or another.
7275 ssh->channels = newtree234(ssh_channelcmp);
7278 * Set up handlers for some connection protocol messages, so we
7279 * don't have to handle them repeatedly in this coroutine.
7281 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
7282 ssh2_msg_channel_window_adjust;
7283 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
7284 ssh2_msg_global_request;
7287 * Create the main session channel.
7289 if (!ssh->cfg.ssh_no_shell) {
7290 ssh->mainchan = snew(struct ssh_channel);
7291 ssh->mainchan->ssh = ssh;
7292 ssh->mainchan->localid = alloc_channel_id(ssh);
7293 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7294 ssh2_pkt_addstring(s->pktout, "session");
7295 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
7296 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
7297 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
7298 ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */
7299 ssh2_pkt_send(ssh, s->pktout);
7300 crWaitUntilV(pktin);
7301 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
7302 bombout(("Server refused to open a session"));
7304 /* FIXME: error data comes back in FAILURE packet */
7306 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
7307 bombout(("Server's channel confirmation cited wrong channel"));
7310 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
7311 ssh->mainchan->halfopen = FALSE;
7312 ssh->mainchan->type = CHAN_MAINSESSION;
7313 ssh->mainchan->closes = 0;
7314 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
7315 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
7316 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
7317 add234(ssh->channels, ssh->mainchan);
7318 update_specials_menu(ssh->frontend);
7319 logevent("Opened channel for session");
7321 ssh->mainchan = NULL;
7324 * Now we have a channel, make dispatch table entries for
7325 * general channel-based messages.
7327 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
7328 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
7329 ssh2_msg_channel_data;
7330 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
7331 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
7332 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
7333 ssh2_msg_channel_open_confirmation;
7334 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
7335 ssh2_msg_channel_open_failure;
7336 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
7337 ssh2_msg_channel_request;
7338 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
7339 ssh2_msg_channel_open;
7342 * Potentially enable X11 forwarding.
7344 if (ssh->mainchan && ssh->cfg.x11_forward) {
7345 char proto[20], data[64];
7346 logevent("Requesting X11 forwarding");
7347 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
7348 data, sizeof(data), ssh->cfg.x11_auth);
7349 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
7350 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7351 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7352 ssh2_pkt_addstring(s->pktout, "x11-req");
7353 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7354 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
7355 ssh2_pkt_addstring(s->pktout, proto);
7357 * Note that while we blank the X authentication data here, we don't
7358 * take any special action to blank the start of an X11 channel,
7359 * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection
7360 * without having session blanking enabled is likely to leak your
7361 * cookie into the log.
7363 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
7364 ssh2_pkt_addstring(s->pktout, data);
7365 end_log_omission(ssh, s->pktout);
7366 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
7367 ssh2_pkt_send(ssh, s->pktout);
7369 crWaitUntilV(pktin);
7371 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7372 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7373 bombout(("Unexpected response to X11 forwarding request:"
7374 " packet type %d", pktin->type));
7377 logevent("X11 forwarding refused");
7379 logevent("X11 forwarding enabled");
7380 ssh->X11_fwd_enabled = TRUE;
7385 * Enable port forwardings.
7387 ssh_setup_portfwd(ssh, &ssh->cfg);
7390 * Potentially enable agent forwarding.
7392 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
7393 logevent("Requesting OpenSSH-style agent forwarding");
7394 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7395 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7396 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
7397 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7398 ssh2_pkt_send(ssh, s->pktout);
7400 crWaitUntilV(pktin);
7402 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7403 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7404 bombout(("Unexpected response to agent forwarding request:"
7405 " packet type %d", pktin->type));
7408 logevent("Agent forwarding refused");
7410 logevent("Agent forwarding enabled");
7411 ssh->agentfwd_enabled = TRUE;
7416 * Now allocate a pty for the session.
7418 if (ssh->mainchan && !ssh->cfg.nopty) {
7419 /* Unpick the terminal-speed string. */
7420 /* XXX perhaps we should allow no speeds to be sent. */
7421 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
7422 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
7423 /* Build the pty request. */
7424 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7425 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7426 ssh2_pkt_addstring(s->pktout, "pty-req");
7427 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7428 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
7429 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
7430 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
7431 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
7432 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
7433 ssh2_pkt_addstring_start(s->pktout);
7434 parse_ttymodes(ssh, ssh->cfg.ttymodes,
7435 ssh2_send_ttymode, (void *)s->pktout);
7436 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_ISPEED);
7437 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
7438 ssh2_pkt_addbyte(s->pktout, SSH2_TTY_OP_OSPEED);
7439 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
7440 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
7441 ssh2_pkt_send(ssh, s->pktout);
7442 ssh->state = SSH_STATE_INTERMED;
7444 crWaitUntilV(pktin);
7446 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7447 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7448 bombout(("Unexpected response to pty request:"
7449 " packet type %d", pktin->type));
7452 c_write_str(ssh, "Server refused to allocate pty\r\n");
7453 ssh->editing = ssh->echoing = 1;
7455 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
7456 ssh->ospeed, ssh->ispeed);
7459 ssh->editing = ssh->echoing = 1;
7463 * Send environment variables.
7465 * Simplest thing here is to send all the requests at once, and
7466 * then wait for a whole bunch of successes or failures.
7468 if (ssh->mainchan && *ssh->cfg.environmt) {
7469 char *e = ssh->cfg.environmt;
7470 char *var, *varend, *val;
7476 while (*e && *e != '\t') e++;
7478 if (*e == '\t') e++;
7483 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7484 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7485 ssh2_pkt_addstring(s->pktout, "env");
7486 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7487 ssh2_pkt_addstring_start(s->pktout);
7488 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7489 ssh2_pkt_addstring(s->pktout, val);
7490 ssh2_pkt_send(ssh, s->pktout);
7495 logeventf(ssh, "Sent %d environment variables", s->num_env);
7498 s->env_left = s->num_env;
7500 while (s->env_left > 0) {
7501 crWaitUntilV(pktin);
7503 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7504 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7505 bombout(("Unexpected response to environment request:"
7506 " packet type %d", pktin->type));
7516 if (s->env_ok == s->num_env) {
7517 logevent("All environment variables successfully set");
7518 } else if (s->env_ok == 0) {
7519 logevent("All environment variables refused");
7520 c_write_str(ssh, "Server refused to set environment variables\r\n");
7522 logeventf(ssh, "%d environment variables refused",
7523 s->num_env - s->env_ok);
7524 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7529 * Start a shell or a remote command. We may have to attempt
7530 * this twice if the config data has provided a second choice
7533 if (ssh->mainchan) while (1) {
7537 if (ssh->fallback_cmd) {
7538 subsys = ssh->cfg.ssh_subsys2;
7539 cmd = ssh->cfg.remote_cmd_ptr2;
7541 subsys = ssh->cfg.ssh_subsys;
7542 cmd = ssh->cfg.remote_cmd_ptr;
7543 if (!cmd) cmd = ssh->cfg.remote_cmd;
7546 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7547 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7549 ssh2_pkt_addstring(s->pktout, "subsystem");
7550 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7551 ssh2_pkt_addstring(s->pktout, cmd);
7553 ssh2_pkt_addstring(s->pktout, "exec");
7554 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7555 ssh2_pkt_addstring(s->pktout, cmd);
7557 ssh2_pkt_addstring(s->pktout, "shell");
7558 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7560 ssh2_pkt_send(ssh, s->pktout);
7562 crWaitUntilV(pktin);
7564 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7565 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7566 bombout(("Unexpected response to shell/command request:"
7567 " packet type %d", pktin->type));
7571 * We failed to start the command. If this is the
7572 * fallback command, we really are finished; if it's
7573 * not, and if the fallback command exists, try falling
7574 * back to it before complaining.
7576 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7577 logevent("Primary command failed; attempting fallback");
7578 ssh->fallback_cmd = TRUE;
7581 bombout(("Server refused to start a shell/command"));
7584 logevent("Started a shell/command");
7589 ssh->state = SSH_STATE_SESSION;
7590 if (ssh->size_needed)
7591 ssh_size(ssh, ssh->term_width, ssh->term_height);
7592 if (ssh->eof_needed)
7593 ssh_special(ssh, TS_EOF);
7599 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7604 s->try_send = FALSE;
7608 * _All_ the connection-layer packets we expect to
7609 * receive are now handled by the dispatch table.
7610 * Anything that reaches here must be bogus.
7613 bombout(("Strange packet received: type %d", pktin->type));
7615 } else if (ssh->mainchan) {
7617 * We have spare data. Add it to the channel buffer.
7619 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7624 struct ssh_channel *c;
7626 * Try to send data on all channels if we can.
7628 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++)
7629 ssh2_try_send_and_unthrottle(c);
7637 * Handlers for SSH-2 messages that might arrive at any moment.
7639 static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7641 /* log reason code in disconnect message */
7643 int nowlen, reason, msglen;
7645 reason = ssh_pkt_getuint32(pktin);
7646 ssh_pkt_getstring(pktin, &msg, &msglen);
7648 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7649 buf = dupprintf("Received disconnect message (%s)",
7650 ssh2_disconnect_reasons[reason]);
7652 buf = dupprintf("Received disconnect message (unknown"
7653 " type %d)", reason);
7657 buf = dupprintf("Disconnection message text: %n%.*s",
7658 &nowlen, msglen, msg);
7660 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7662 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7663 ssh2_disconnect_reasons[reason] : "unknown",
7668 static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7670 /* log the debug message */
7675 /* XXX maybe we should actually take notice of this */
7676 always_display = ssh2_pkt_getbool(pktin);
7677 ssh_pkt_getstring(pktin, &msg, &msglen);
7679 logeventf(ssh, "Remote debug message: %.*s", msglen, msg);
7682 static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7684 struct Packet *pktout;
7685 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7686 ssh2_pkt_adduint32(pktout, pktin->sequence);
7688 * UNIMPLEMENTED messages MUST appear in the same order as the
7689 * messages they respond to. Hence, never queue them.
7691 ssh2_pkt_send_noqueue(ssh, pktout);
7695 * Handle the top-level SSH-2 protocol.
7697 static void ssh2_protocol_setup(Ssh ssh)
7702 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7704 for (i = 0; i < 256; i++)
7705 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7708 * Any message we actually understand, we set to NULL so that
7709 * the coroutines will get it.
7711 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7712 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7713 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7714 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7715 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7716 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7717 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7718 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7719 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7720 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7721 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7722 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7723 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7724 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7725 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7726 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7727 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7728 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7729 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7730 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7731 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7732 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7733 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7734 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7735 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7736 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7737 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7738 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7739 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7740 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7741 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7742 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7743 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7746 * These special message types we install handlers for.
7748 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7749 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with SSH-1 */
7750 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7753 static void ssh2_timer(void *ctx, long now)
7757 if (ssh->state == SSH_STATE_CLOSED)
7760 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7761 now - ssh->next_rekey >= 0) {
7762 do_ssh2_transport(ssh, "timeout", -1, NULL);
7766 static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
7767 struct Packet *pktin)
7769 unsigned char *in = (unsigned char *)vin;
7770 if (ssh->state == SSH_STATE_CLOSED)
7774 ssh->incoming_data_size += pktin->encrypted_len;
7775 if (!ssh->kex_in_progress &&
7776 ssh->max_data_size != 0 &&
7777 ssh->incoming_data_size > ssh->max_data_size)
7778 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7781 if (pktin && ssh->packet_dispatch[pktin->type]) {
7782 ssh->packet_dispatch[pktin->type](ssh, pktin);
7786 if (!ssh->protocol_initial_phase_done ||
7787 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7788 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7789 !ssh->protocol_initial_phase_done) {
7790 ssh->protocol_initial_phase_done = TRUE;
7792 * Allow authconn to initialise itself.
7794 do_ssh2_authconn(ssh, NULL, 0, NULL);
7797 do_ssh2_authconn(ssh, in, inlen, pktin);
7802 * Called to set up the connection.
7804 * Returns an error message, or NULL on success.
7806 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7808 char *host, int port, char **realhost, int nodelay,
7814 ssh = snew(struct ssh_tag);
7815 ssh->cfg = *cfg; /* STRUCTURE COPY */
7816 ssh->version = 0; /* when not ready yet */
7819 ssh->v1_cipher_ctx = NULL;
7820 ssh->crcda_ctx = NULL;
7821 ssh->cscipher = NULL;
7822 ssh->cs_cipher_ctx = NULL;
7823 ssh->sccipher = NULL;
7824 ssh->sc_cipher_ctx = NULL;
7826 ssh->cs_mac_ctx = NULL;
7828 ssh->sc_mac_ctx = NULL;
7830 ssh->cs_comp_ctx = NULL;
7832 ssh->sc_comp_ctx = NULL;
7834 ssh->kex_ctx = NULL;
7835 ssh->hostkey = NULL;
7837 ssh->close_expected = FALSE;
7838 ssh->clean_exit = FALSE;
7839 ssh->state = SSH_STATE_PREPACKET;
7840 ssh->size_needed = FALSE;
7841 ssh->eof_needed = FALSE;
7844 ssh->deferred_send_data = NULL;
7845 ssh->deferred_len = 0;
7846 ssh->deferred_size = 0;
7847 ssh->fallback_cmd = 0;
7849 ssh->x11auth = NULL;
7850 ssh->v1_compressing = FALSE;
7851 ssh->v2_outgoing_sequence = 0;
7852 ssh->ssh1_rdpkt_crstate = 0;
7853 ssh->ssh2_rdpkt_crstate = 0;
7854 ssh->do_ssh_init_crstate = 0;
7855 ssh->ssh_gotdata_crstate = 0;
7856 ssh->do_ssh1_connection_crstate = 0;
7857 ssh->do_ssh1_login_crstate = 0;
7858 ssh->do_ssh2_transport_crstate = 0;
7859 ssh->do_ssh2_authconn_crstate = 0;
7860 ssh->do_ssh_init_state = NULL;
7861 ssh->do_ssh1_login_state = NULL;
7862 ssh->do_ssh2_transport_state = NULL;
7863 ssh->do_ssh2_authconn_state = NULL;
7864 ssh->mainchan = NULL;
7865 ssh->throttled_all = 0;
7866 ssh->v1_stdout_throttling = 0;
7868 ssh->queuelen = ssh->queuesize = 0;
7869 ssh->queueing = FALSE;
7870 ssh->qhead = ssh->qtail = NULL;
7871 ssh->deferred_rekey_reason = NULL;
7872 bufchain_init(&ssh->queued_incoming_data);
7873 ssh->frozen = FALSE;
7875 *backend_handle = ssh;
7878 if (crypto_startup() == 0)
7879 return "Microsoft high encryption pack not installed!";
7882 ssh->frontend = frontend_handle;
7883 ssh->term_width = ssh->cfg.width;
7884 ssh->term_height = ssh->cfg.height;
7886 ssh->channels = NULL;
7887 ssh->rportfwds = NULL;
7888 ssh->portfwds = NULL;
7893 ssh->v1_throttle_count = 0;
7894 ssh->overall_bufsize = 0;
7895 ssh->fallback_cmd = 0;
7897 ssh->protocol = NULL;
7899 ssh->protocol_initial_phase_done = FALSE;
7903 ssh->incoming_data_size = ssh->outgoing_data_size =
7904 ssh->deferred_data_size = 0L;
7905 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7906 ssh->kex_in_progress = FALSE;
7908 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7917 static void ssh_free(void *handle)
7919 Ssh ssh = (Ssh) handle;
7920 struct ssh_channel *c;
7921 struct ssh_rportfwd *pf;
7923 if (ssh->v1_cipher_ctx)
7924 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7925 if (ssh->cs_cipher_ctx)
7926 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7927 if (ssh->sc_cipher_ctx)
7928 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7929 if (ssh->cs_mac_ctx)
7930 ssh->csmac->free_context(ssh->cs_mac_ctx);
7931 if (ssh->sc_mac_ctx)
7932 ssh->scmac->free_context(ssh->sc_mac_ctx);
7933 if (ssh->cs_comp_ctx) {
7935 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7937 zlib_compress_cleanup(ssh->cs_comp_ctx);
7939 if (ssh->sc_comp_ctx) {
7941 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7943 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7946 dh_cleanup(ssh->kex_ctx);
7947 sfree(ssh->savedhost);
7949 while (ssh->queuelen-- > 0)
7950 ssh_free_packet(ssh->queue[ssh->queuelen]);
7953 while (ssh->qhead) {
7954 struct queued_handler *qh = ssh->qhead;
7955 ssh->qhead = qh->next;
7958 ssh->qhead = ssh->qtail = NULL;
7960 if (ssh->channels) {
7961 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7964 if (c->u.x11.s != NULL)
7965 x11_close(c->u.x11.s);
7968 if (c->u.pfd.s != NULL)
7969 pfd_close(c->u.pfd.s);
7974 freetree234(ssh->channels);
7975 ssh->channels = NULL;
7978 if (ssh->rportfwds) {
7979 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7981 freetree234(ssh->rportfwds);
7982 ssh->rportfwds = NULL;
7984 sfree(ssh->deferred_send_data);
7986 x11_free_auth(ssh->x11auth);
7987 sfree(ssh->do_ssh_init_state);
7988 sfree(ssh->do_ssh1_login_state);
7989 sfree(ssh->do_ssh2_transport_state);
7990 sfree(ssh->do_ssh2_authconn_state);
7991 if (ssh->crcda_ctx) {
7992 crcda_free_context(ssh->crcda_ctx);
7993 ssh->crcda_ctx = NULL;
7996 ssh_do_close(ssh, TRUE);
7997 expire_timer_context(ssh);
7999 pinger_free(ssh->pinger);
8000 bufchain_clear(&ssh->queued_incoming_data);
8007 * Reconfigure the SSH backend.
8009 static void ssh_reconfig(void *handle, Config *cfg)
8011 Ssh ssh = (Ssh) handle;
8012 char *rekeying = NULL, rekey_mandatory = FALSE;
8013 unsigned long old_max_data_size;
8015 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
8017 ssh_setup_portfwd(ssh, cfg);
8019 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
8020 cfg->ssh_rekey_time != 0) {
8021 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
8022 long now = GETTICKCOUNT();
8024 if (new_next - now < 0) {
8025 rekeying = "timeout shortened";
8027 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
8031 old_max_data_size = ssh->max_data_size;
8032 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
8033 if (old_max_data_size != ssh->max_data_size &&
8034 ssh->max_data_size != 0) {
8035 if (ssh->outgoing_data_size > ssh->max_data_size ||
8036 ssh->incoming_data_size > ssh->max_data_size)
8037 rekeying = "data limit lowered";
8040 if (ssh->cfg.compression != cfg->compression) {
8041 rekeying = "compression setting changed";
8042 rekey_mandatory = TRUE;
8045 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
8046 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
8047 sizeof(ssh->cfg.ssh_cipherlist))) {
8048 rekeying = "cipher settings changed";
8049 rekey_mandatory = TRUE;
8052 ssh->cfg = *cfg; /* STRUCTURE COPY */
8055 if (!ssh->kex_in_progress) {
8056 do_ssh2_transport(ssh, rekeying, -1, NULL);
8057 } else if (rekey_mandatory) {
8058 ssh->deferred_rekey_reason = rekeying;
8064 * Called to send data down the SSH connection.
8066 static int ssh_send(void *handle, char *buf, int len)
8068 Ssh ssh = (Ssh) handle;
8070 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8073 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
8075 return ssh_sendbuffer(ssh);
8079 * Called to query the current amount of buffered stdin data.
8081 static int ssh_sendbuffer(void *handle)
8083 Ssh ssh = (Ssh) handle;
8086 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
8090 * If the SSH socket itself has backed up, add the total backup
8091 * size on that to any individual buffer on the stdin channel.
8094 if (ssh->throttled_all)
8095 override_value = ssh->overall_bufsize;
8097 if (ssh->version == 1) {
8098 return override_value;
8099 } else if (ssh->version == 2) {
8100 if (!ssh->mainchan || ssh->mainchan->closes > 0)
8101 return override_value;
8103 return (override_value +
8104 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
8111 * Called to set the size of the window from SSH's POV.
8113 static void ssh_size(void *handle, int width, int height)
8115 Ssh ssh = (Ssh) handle;
8116 struct Packet *pktout;
8118 ssh->term_width = width;
8119 ssh->term_height = height;
8121 switch (ssh->state) {
8122 case SSH_STATE_BEFORE_SIZE:
8123 case SSH_STATE_PREPACKET:
8124 case SSH_STATE_CLOSED:
8125 break; /* do nothing */
8126 case SSH_STATE_INTERMED:
8127 ssh->size_needed = TRUE; /* buffer for later */
8129 case SSH_STATE_SESSION:
8130 if (!ssh->cfg.nopty) {
8131 if (ssh->version == 1) {
8132 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
8133 PKT_INT, ssh->term_height,
8134 PKT_INT, ssh->term_width,
8135 PKT_INT, 0, PKT_INT, 0, PKT_END);
8136 } else if (ssh->mainchan) {
8137 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8138 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8139 ssh2_pkt_addstring(pktout, "window-change");
8140 ssh2_pkt_addbool(pktout, 0);
8141 ssh2_pkt_adduint32(pktout, ssh->term_width);
8142 ssh2_pkt_adduint32(pktout, ssh->term_height);
8143 ssh2_pkt_adduint32(pktout, 0);
8144 ssh2_pkt_adduint32(pktout, 0);
8145 ssh2_pkt_send(ssh, pktout);
8153 * Return a list of the special codes that make sense in this
8156 static const struct telnet_special *ssh_get_specials(void *handle)
8158 static const struct telnet_special ssh1_ignore_special[] = {
8159 {"IGNORE message", TS_NOP}
8161 static const struct telnet_special ssh2_transport_specials[] = {
8162 {"IGNORE message", TS_NOP},
8163 {"Repeat key exchange", TS_REKEY},
8165 static const struct telnet_special ssh2_session_specials[] = {
8168 /* These are the signal names defined by draft-ietf-secsh-connect-23.
8169 * They include all the ISO C signals, but are a subset of the POSIX
8170 * required signals. */
8171 {"SIGINT (Interrupt)", TS_SIGINT},
8172 {"SIGTERM (Terminate)", TS_SIGTERM},
8173 {"SIGKILL (Kill)", TS_SIGKILL},
8174 {"SIGQUIT (Quit)", TS_SIGQUIT},
8175 {"SIGHUP (Hangup)", TS_SIGHUP},
8176 {"More signals", TS_SUBMENU},
8177 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
8178 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
8179 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
8180 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
8183 static const struct telnet_special specials_end[] = {
8186 /* XXX review this length for any changes: */
8187 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
8188 lenof(ssh2_session_specials) +
8189 lenof(specials_end)];
8190 Ssh ssh = (Ssh) handle;
8192 #define ADD_SPECIALS(name) \
8194 assert((i + lenof(name)) <= lenof(ssh_specials)); \
8195 memcpy(&ssh_specials[i], name, sizeof name); \
8199 if (ssh->version == 1) {
8200 /* Don't bother offering IGNORE if we've decided the remote
8201 * won't cope with it, since we wouldn't bother sending it if
8203 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8204 ADD_SPECIALS(ssh1_ignore_special);
8205 } else if (ssh->version == 2) {
8206 ADD_SPECIALS(ssh2_transport_specials);
8208 ADD_SPECIALS(ssh2_session_specials);
8209 } /* else we're not ready yet */
8212 ADD_SPECIALS(specials_end);
8213 return ssh_specials;
8221 * Send special codes. TS_EOF is useful for `plink', so you
8222 * can send an EOF and collect resulting output (e.g. `plink
8225 static void ssh_special(void *handle, Telnet_Special code)
8227 Ssh ssh = (Ssh) handle;
8228 struct Packet *pktout;
8230 if (code == TS_EOF) {
8231 if (ssh->state != SSH_STATE_SESSION) {
8233 * Buffer the EOF in case we are pre-SESSION, so we can
8234 * send it as soon as we reach SESSION.
8237 ssh->eof_needed = TRUE;
8240 if (ssh->version == 1) {
8241 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
8242 } else if (ssh->mainchan) {
8243 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
8244 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8245 ssh2_pkt_send(ssh, pktout);
8246 ssh->send_ok = 0; /* now stop trying to read from stdin */
8248 logevent("Sent EOF message");
8249 } else if (code == TS_PING || code == TS_NOP) {
8250 if (ssh->state == SSH_STATE_CLOSED
8251 || ssh->state == SSH_STATE_PREPACKET) return;
8252 if (ssh->version == 1) {
8253 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
8254 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
8256 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
8257 ssh2_pkt_addstring_start(pktout);
8258 ssh2_pkt_send_noqueue(ssh, pktout);
8260 } else if (code == TS_REKEY) {
8261 if (!ssh->kex_in_progress && ssh->version == 2) {
8262 do_ssh2_transport(ssh, "at user request", -1, NULL);
8264 } else if (code == TS_BRK) {
8265 if (ssh->state == SSH_STATE_CLOSED
8266 || ssh->state == SSH_STATE_PREPACKET) return;
8267 if (ssh->version == 1) {
8268 logevent("Unable to send BREAK signal in SSH-1");
8269 } else if (ssh->mainchan) {
8270 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8271 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8272 ssh2_pkt_addstring(pktout, "break");
8273 ssh2_pkt_addbool(pktout, 0);
8274 ssh2_pkt_adduint32(pktout, 0); /* default break length */
8275 ssh2_pkt_send(ssh, pktout);
8278 /* Is is a POSIX signal? */
8279 char *signame = NULL;
8280 if (code == TS_SIGABRT) signame = "ABRT";
8281 if (code == TS_SIGALRM) signame = "ALRM";
8282 if (code == TS_SIGFPE) signame = "FPE";
8283 if (code == TS_SIGHUP) signame = "HUP";
8284 if (code == TS_SIGILL) signame = "ILL";
8285 if (code == TS_SIGINT) signame = "INT";
8286 if (code == TS_SIGKILL) signame = "KILL";
8287 if (code == TS_SIGPIPE) signame = "PIPE";
8288 if (code == TS_SIGQUIT) signame = "QUIT";
8289 if (code == TS_SIGSEGV) signame = "SEGV";
8290 if (code == TS_SIGTERM) signame = "TERM";
8291 if (code == TS_SIGUSR1) signame = "USR1";
8292 if (code == TS_SIGUSR2) signame = "USR2";
8293 /* The SSH-2 protocol does in principle support arbitrary named
8294 * signals, including signame@domain, but we don't support those. */
8296 /* It's a signal. */
8297 if (ssh->version == 2 && ssh->mainchan) {
8298 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
8299 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
8300 ssh2_pkt_addstring(pktout, "signal");
8301 ssh2_pkt_addbool(pktout, 0);
8302 ssh2_pkt_addstring(pktout, signame);
8303 ssh2_pkt_send(ssh, pktout);
8304 logeventf(ssh, "Sent signal SIG%s", signame);
8307 /* Never heard of it. Do nothing */
8312 void *new_sock_channel(void *handle, Socket s)
8314 Ssh ssh = (Ssh) handle;
8315 struct ssh_channel *c;
8316 c = snew(struct ssh_channel);
8321 c->localid = alloc_channel_id(ssh);
8323 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
8325 bufchain_init(&c->v.v2.outbuffer);
8326 add234(ssh->channels, c);
8332 * This is called when stdout/stderr (the entity to which
8333 * from_backend sends data) manages to clear some backlog.
8335 static void ssh_unthrottle(void *handle, int bufsize)
8337 Ssh ssh = (Ssh) handle;
8338 if (ssh->version == 1) {
8339 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
8340 ssh->v1_stdout_throttling = 0;
8341 ssh1_throttle(ssh, -1);
8344 if (ssh->mainchan && ssh->mainchan->closes == 0)
8345 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
8349 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
8351 struct ssh_channel *c = (struct ssh_channel *)channel;
8353 struct Packet *pktout;
8355 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
8357 if (ssh->version == 1) {
8358 send_packet(ssh, SSH1_MSG_PORT_OPEN,
8359 PKT_INT, c->localid,
8362 /* PKT_STR, <org:orgport>, */
8365 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
8366 ssh2_pkt_addstring(pktout, "direct-tcpip");
8367 ssh2_pkt_adduint32(pktout, c->localid);
8368 c->v.v2.locwindow = OUR_V2_WINSIZE;
8369 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
8370 ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
8371 ssh2_pkt_addstring(pktout, hostname);
8372 ssh2_pkt_adduint32(pktout, port);
8374 * We make up values for the originator data; partly it's
8375 * too much hassle to keep track, and partly I'm not
8376 * convinced the server should be told details like that
8377 * about my local network configuration.
8379 ssh2_pkt_addstring(pktout, "client-side-connection");
8380 ssh2_pkt_adduint32(pktout, 0);
8381 ssh2_pkt_send(ssh, pktout);
8385 static Socket ssh_socket(void *handle)
8387 Ssh ssh = (Ssh) handle;
8391 static int ssh_sendok(void *handle)
8393 Ssh ssh = (Ssh) handle;
8394 return ssh->send_ok;
8397 static int ssh_ldisc(void *handle, int option)
8399 Ssh ssh = (Ssh) handle;
8400 if (option == LD_ECHO)
8401 return ssh->echoing;
8402 if (option == LD_EDIT)
8403 return ssh->editing;
8407 static void ssh_provide_ldisc(void *handle, void *ldisc)
8409 Ssh ssh = (Ssh) handle;
8413 static void ssh_provide_logctx(void *handle, void *logctx)
8415 Ssh ssh = (Ssh) handle;
8416 ssh->logctx = logctx;
8419 static int ssh_return_exitcode(void *handle)
8421 Ssh ssh = (Ssh) handle;
8425 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
8429 * cfg_info for SSH is the currently running version of the
8430 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
8432 static int ssh_cfg_info(void *handle)
8434 Ssh ssh = (Ssh) handle;
8435 return ssh->version;
8439 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
8440 * that fails. This variable is the means by which scp.c can reach
8441 * into the SSH code and find out which one it got.
8443 extern int ssh_fallback_cmd(void *handle)
8445 Ssh ssh = (Ssh) handle;
8446 return ssh->fallback_cmd;
8449 Backend ssh_backend = {
8459 ssh_return_exitcode,