18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
22 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
23 (s ? sk_close(s), s = NULL : 0), \
24 connection_fatal msg )
26 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29 #define SSH1_CMSG_USER 4 /* 0x4 */
30 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
39 #define SSH1_SMSG_FAILURE 15 /* 0xf */
40 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43 #define SSH1_CMSG_EOF 19 /* 0x13 */
44 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
50 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
53 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
55 #define SSH1_MSG_IGNORE 32 /* 0x20 */
56 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
59 #define SSH1_MSG_DEBUG 36 /* 0x24 */
60 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
61 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
68 #define SSH1_AUTH_TIS 5 /* 0x5 */
69 #define SSH1_AUTH_CCARD 16 /* 0x10 */
71 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
72 /* Mask for protoflags we will echo back to server if seen */
73 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
75 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
76 #define SSH2_MSG_IGNORE 2 /* 0x2 */
77 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
78 #define SSH2_MSG_DEBUG 4 /* 0x4 */
79 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
80 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
81 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
82 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
83 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
84 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
85 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
86 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
87 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
88 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
89 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
96 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
97 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
98 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
99 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
100 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
101 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
102 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
103 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
104 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
105 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
106 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
107 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
108 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
109 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
110 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
113 * Packet type contexts, so that ssh2_pkt_type can correctly decode
114 * the ambiguous type numbers back into the correct type strings.
116 #define SSH2_PKTCTX_DHGROUP1 0x0001
117 #define SSH2_PKTCTX_DHGEX 0x0002
118 #define SSH2_PKTCTX_PUBLICKEY 0x0010
119 #define SSH2_PKTCTX_PASSWORD 0x0020
120 #define SSH2_PKTCTX_KBDINTER 0x0040
121 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
123 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
124 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
125 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
126 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
127 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
128 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
129 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
130 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
131 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
132 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
133 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
134 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
135 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
136 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
137 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
139 static const char *const ssh2_disconnect_reasons[] = {
141 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
142 "SSH_DISCONNECT_PROTOCOL_ERROR",
143 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
144 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
145 "SSH_DISCONNECT_MAC_ERROR",
146 "SSH_DISCONNECT_COMPRESSION_ERROR",
147 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
148 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
149 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
150 "SSH_DISCONNECT_CONNECTION_LOST",
151 "SSH_DISCONNECT_BY_APPLICATION",
152 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
153 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
154 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
155 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
158 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
159 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
160 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
161 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
163 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
166 * Various remote-bug flags.
168 #define BUG_CHOKES_ON_SSH1_IGNORE 1
169 #define BUG_SSH2_HMAC 2
170 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
172 static int ssh_pkt_ctx = 0;
174 #define translate(x) if (type == x) return #x
175 #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
176 char *ssh1_pkt_type(int type)
178 translate(SSH1_MSG_DISCONNECT);
179 translate(SSH1_SMSG_PUBLIC_KEY);
180 translate(SSH1_CMSG_SESSION_KEY);
181 translate(SSH1_CMSG_USER);
182 translate(SSH1_CMSG_AUTH_RSA);
183 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
184 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
185 translate(SSH1_CMSG_AUTH_PASSWORD);
186 translate(SSH1_CMSG_REQUEST_PTY);
187 translate(SSH1_CMSG_WINDOW_SIZE);
188 translate(SSH1_CMSG_EXEC_SHELL);
189 translate(SSH1_CMSG_EXEC_CMD);
190 translate(SSH1_SMSG_SUCCESS);
191 translate(SSH1_SMSG_FAILURE);
192 translate(SSH1_CMSG_STDIN_DATA);
193 translate(SSH1_SMSG_STDOUT_DATA);
194 translate(SSH1_SMSG_STDERR_DATA);
195 translate(SSH1_CMSG_EOF);
196 translate(SSH1_SMSG_EXIT_STATUS);
197 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
198 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
199 translate(SSH1_MSG_CHANNEL_DATA);
200 translate(SSH1_MSG_CHANNEL_CLOSE);
201 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
202 translate(SSH1_SMSG_X11_OPEN);
203 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
204 translate(SSH1_MSG_PORT_OPEN);
205 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
206 translate(SSH1_SMSG_AGENT_OPEN);
207 translate(SSH1_MSG_IGNORE);
208 translate(SSH1_CMSG_EXIT_CONFIRMATION);
209 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
210 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
211 translate(SSH1_MSG_DEBUG);
212 translate(SSH1_CMSG_REQUEST_COMPRESSION);
213 translate(SSH1_CMSG_AUTH_TIS);
214 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
215 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
216 translate(SSH1_CMSG_AUTH_CCARD);
217 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
218 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
221 char *ssh2_pkt_type(int type)
223 translate(SSH2_MSG_DISCONNECT);
224 translate(SSH2_MSG_IGNORE);
225 translate(SSH2_MSG_UNIMPLEMENTED);
226 translate(SSH2_MSG_DEBUG);
227 translate(SSH2_MSG_SERVICE_REQUEST);
228 translate(SSH2_MSG_SERVICE_ACCEPT);
229 translate(SSH2_MSG_KEXINIT);
230 translate(SSH2_MSG_NEWKEYS);
231 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
232 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
233 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
234 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
235 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
236 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
237 translate(SSH2_MSG_USERAUTH_REQUEST);
238 translate(SSH2_MSG_USERAUTH_FAILURE);
239 translate(SSH2_MSG_USERAUTH_SUCCESS);
240 translate(SSH2_MSG_USERAUTH_BANNER);
241 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
242 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
243 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
244 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
245 translate(SSH2_MSG_GLOBAL_REQUEST);
246 translate(SSH2_MSG_REQUEST_SUCCESS);
247 translate(SSH2_MSG_REQUEST_FAILURE);
248 translate(SSH2_MSG_CHANNEL_OPEN);
249 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
250 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
251 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
252 translate(SSH2_MSG_CHANNEL_DATA);
253 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
254 translate(SSH2_MSG_CHANNEL_EOF);
255 translate(SSH2_MSG_CHANNEL_CLOSE);
256 translate(SSH2_MSG_CHANNEL_REQUEST);
257 translate(SSH2_MSG_CHANNEL_SUCCESS);
258 translate(SSH2_MSG_CHANNEL_FAILURE);
264 #define GET_32BIT(cp) \
265 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
266 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
267 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
268 ((unsigned long)(unsigned char)(cp)[3]))
270 #define PUT_32BIT(cp, value) { \
271 (cp)[0] = (unsigned char)((value) >> 24); \
272 (cp)[1] = (unsigned char)((value) >> 16); \
273 (cp)[2] = (unsigned char)((value) >> 8); \
274 (cp)[3] = (unsigned char)(value); }
276 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
278 /* Coroutine mechanics for the sillier bits of the code */
279 #define crBegin1 static int crLine = 0;
280 #define crBegin2 switch(crLine) { case 0:;
281 #define crBegin crBegin1; crBegin2;
282 #define crFinish(z) } crLine = 0; return (z)
283 #define crFinishV } crLine = 0; return
284 #define crReturn(z) \
286 crLine=__LINE__; return (z); case __LINE__:;\
290 crLine=__LINE__; return; case __LINE__:;\
292 #define crStop(z) do{ crLine = 0; return (z); }while(0)
293 #define crStopV do{ crLine = 0; return; }while(0)
294 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
295 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
297 extern char *x11_init(Socket *, char *, void *);
298 extern void x11_close(Socket);
299 extern int x11_send(Socket, char *, int);
300 extern void x11_invent_auth(char *, int, char *, int);
301 extern void x11_unthrottle(Socket s);
302 extern void x11_override_throttle(Socket s, int enable);
304 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
305 extern char *pfd_addforward(char *desthost, int destport, int port);
306 extern void pfd_close(Socket s);
307 extern int pfd_send(Socket s, char *data, int len);
308 extern void pfd_confirm(Socket s);
309 extern void pfd_unthrottle(Socket s);
310 extern void pfd_override_throttle(Socket s, int enable);
313 * Buffer management constants. There are several of these for
314 * various different purposes:
316 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
317 * on a local data stream before we throttle the whole SSH
318 * connection (in SSH1 only). Throttling the whole connection is
319 * pretty drastic so we set this high in the hope it won't
322 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
323 * on the SSH connection itself before we defensively throttle
324 * _all_ local data streams. This is pretty drastic too (though
325 * thankfully unlikely in SSH2 since the window mechanism should
326 * ensure that the server never has any need to throttle its end
327 * of the connection), so we set this high as well.
329 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
333 #define SSH1_BUFFER_LIMIT 32768
334 #define SSH_MAX_BACKLOG 32768
335 #define OUR_V2_WINSIZE 16384
337 const static struct ssh_kex *kex_algs[] = {
338 &ssh_diffiehellman_gex,
342 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
344 static void nullmac_key(unsigned char *key)
347 static void nullmac_generate(unsigned char *blk, int len,
351 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
355 const static struct ssh_mac ssh_mac_none = {
356 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
358 const static struct ssh_mac *macs[] = {
359 &ssh_sha1, &ssh_md5, &ssh_mac_none
361 const static struct ssh_mac *buggymacs[] = {
362 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
365 static void ssh_comp_none_init(void)
368 static int ssh_comp_none_block(unsigned char *block, int len,
369 unsigned char **outblock, int *outlen)
373 static int ssh_comp_none_disable(void)
377 const static struct ssh_compress ssh_comp_none = {
379 ssh_comp_none_init, ssh_comp_none_block,
380 ssh_comp_none_init, ssh_comp_none_block,
381 ssh_comp_none_disable
383 extern const struct ssh_compress ssh_zlib;
384 const static struct ssh_compress *compressions[] = {
385 &ssh_zlib, &ssh_comp_none
388 enum { /* channel types */
393 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
397 * 2-3-4 tree storing channels.
400 unsigned remoteid, localid;
404 struct ssh1_data_channel {
407 struct ssh2_data_channel {
409 unsigned remwindow, remmaxpkt;
414 struct ssh_agent_channel {
415 unsigned char *message;
416 unsigned char msglen[4];
417 int lensofar, totallen;
419 struct ssh_x11_channel {
422 struct ssh_pfd_channel {
429 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
430 * 2 use this structure in different ways, reflecting SSH 2's
431 * altogether saner approach to port forwarding.
433 * In SSH 1, you arrange a remote forwarding by sending the server
434 * the remote port number, and the local destination host:port.
435 * When a connection comes in, the server sends you back that
436 * host:port pair, and you connect to it. This is a ready-made
437 * security hole if you're not on the ball: a malicious server
438 * could send you back _any_ host:port pair, so if you trustingly
439 * connect to the address it gives you then you've just opened the
440 * entire inside of your corporate network just by connecting
441 * through it to a dodgy SSH server. Hence, we must store a list of
442 * host:port pairs we _are_ trying to forward to, and reject a
443 * connection request from the server if it's not in the list.
445 * In SSH 2, each side of the connection minds its own business and
446 * doesn't send unnecessary information to the other. You arrange a
447 * remote forwarding by sending the server just the remote port
448 * number. When a connection comes in, the server tells you which
449 * of its ports was connected to; and _you_ have to remember what
450 * local host:port pair went with that port number.
452 * Hence: in SSH 1 this structure stores host:port pairs we intend
453 * to allow connections to, and is indexed by those host:port
454 * pairs. In SSH 2 it stores a mapping from source port to
455 * destination host:port pair, and is indexed by source port.
457 struct ssh_rportfwd {
458 unsigned sport, dport;
471 static SHA_State exhash, exhashbase;
473 static Socket s = NULL;
475 static unsigned char session_key[32];
476 static int ssh1_compressing;
477 static int ssh1_remote_protoflags;
478 static int ssh1_local_protoflags;
479 static int ssh_agentfwd_enabled;
480 static int ssh_X11_fwd_enabled;
481 static int ssh_remote_bugs;
482 static const struct ssh_cipher *cipher = NULL;
483 static const struct ssh2_cipher *cscipher = NULL;
484 static const struct ssh2_cipher *sccipher = NULL;
485 static const struct ssh_mac *csmac = NULL;
486 static const struct ssh_mac *scmac = NULL;
487 static const struct ssh_compress *cscomp = NULL;
488 static const struct ssh_compress *sccomp = NULL;
489 static const struct ssh_kex *kex = NULL;
490 static const struct ssh_signkey *hostkey = NULL;
491 static unsigned char ssh2_session_id[20];
492 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
495 static char *savedhost;
496 static int savedport;
497 static int ssh_send_ok;
498 static int ssh_echoing, ssh_editing;
500 static tree234 *ssh_channels; /* indexed by local id */
501 static struct ssh_channel *mainchan; /* primary session channel */
502 static int ssh_exitcode = -1;
504 static tree234 *ssh_rportfwds;
508 SSH_STATE_BEFORE_SIZE,
512 } ssh_state = SSH_STATE_PREPACKET;
514 static int size_needed = FALSE, eof_needed = FALSE;
516 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
517 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
518 static unsigned char *deferred_send_data = NULL;
519 static int deferred_len = 0, deferred_size = 0;
522 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
523 * that fails. This variable is the means by which scp.c can reach
524 * into the SSH code and find out which one it got.
526 int ssh_fallback_cmd = 0;
528 static int ssh_version;
529 static int ssh1_throttle_count;
530 static int ssh_overall_bufsize;
531 static int ssh_throttled_all;
532 static int ssh1_stdout_throttling;
533 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
534 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
535 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
536 static void ssh_size(void);
537 static void ssh_special(Telnet_Special);
538 static int ssh2_try_send(struct ssh_channel *c);
539 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
541 static void ssh_throttle_all(int enable, int bufsize);
542 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
543 static int (*s_rdpkt) (unsigned char **data, int *datalen);
544 static int ssh_sendbuffer(void);
546 static struct rdpkt1_state_tag {
547 long len, pad, biglen, to_read;
548 unsigned long realcrc, gotcrc;
554 static struct rdpkt2_state_tag {
555 long len, pad, payload, packetlen, maclen;
558 unsigned long incoming_sequence;
561 static int ssh_channelcmp(void *av, void *bv)
563 struct ssh_channel *a = (struct ssh_channel *) av;
564 struct ssh_channel *b = (struct ssh_channel *) bv;
565 if (a->localid < b->localid)
567 if (a->localid > b->localid)
571 static int ssh_channelfind(void *av, void *bv)
573 unsigned *a = (unsigned *) av;
574 struct ssh_channel *b = (struct ssh_channel *) bv;
582 static int ssh_rportcmp_ssh1(void *av, void *bv)
584 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
585 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
587 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
588 return i < 0 ? -1 : +1;
589 if (a->dport > b->dport)
591 if (a->dport < b->dport)
596 static int ssh_rportcmp_ssh2(void *av, void *bv)
598 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
599 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
601 if (a->sport > b->sport)
603 if (a->sport < b->sport)
608 static int alloc_channel_id(void)
610 const unsigned CHANNEL_NUMBER_OFFSET = 256;
611 unsigned low, high, mid;
613 struct ssh_channel *c;
616 * First-fit allocation of channel numbers: always pick the
617 * lowest unused one. To do this, binary-search using the
618 * counted B-tree to find the largest channel ID which is in a
619 * contiguous sequence from the beginning. (Precisely
620 * everything in that sequence must have ID equal to its tree
621 * index plus CHANNEL_NUMBER_OFFSET.)
623 tsize = count234(ssh_channels);
627 while (high - low > 1) {
628 mid = (high + low) / 2;
629 c = index234(ssh_channels, mid);
630 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
631 low = mid; /* this one is fine */
633 high = mid; /* this one is past it */
636 * Now low points to either -1, or the tree index of the
637 * largest ID in the initial sequence.
640 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
641 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
643 return low + 1 + CHANNEL_NUMBER_OFFSET;
646 static void c_write(char *buf, int len)
648 if ((flags & FLAG_STDERR)) {
650 for (i = 0; i < len; i++)
652 fputc(buf[i], stderr);
655 from_backend(1, buf, len);
658 static void c_write_untrusted(char *buf, int len)
661 for (i = 0; i < len; i++) {
664 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
669 static void c_write_str(char *buf)
671 c_write(buf, strlen(buf));
675 * Collect incoming data in the incoming packet buffer.
676 * Decipher and verify the packet when it is completely read.
677 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
678 * Update the *data and *datalen variables.
679 * Return the additional nr of bytes needed, or 0 when
680 * a complete packet is available.
682 static int ssh1_rdpkt(unsigned char **data, int *datalen)
684 struct rdpkt1_state_tag *st = &rdpkt1_state;
693 for (st->i = st->len = 0; st->i < 4; st->i++) {
694 while ((*datalen) == 0)
696 st->len = (st->len << 8) + **data;
697 (*data)++, (*datalen)--;
700 st->pad = 8 - (st->len % 8);
701 st->biglen = st->len + st->pad;
702 pktin.length = st->len - 5;
704 if (pktin.maxlen < st->biglen) {
705 pktin.maxlen = st->biglen;
706 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
707 srealloc(pktin.data, st->biglen + APIEXTRA));
709 fatalbox("Out of memory");
712 st->to_read = st->biglen;
714 while (st->to_read > 0) {
715 st->chunk = st->to_read;
716 while ((*datalen) == 0)
717 crReturn(st->to_read);
718 if (st->chunk > (*datalen))
719 st->chunk = (*datalen);
720 memcpy(st->p, *data, st->chunk);
722 *datalen -= st->chunk;
724 st->to_read -= st->chunk;
728 cipher->decrypt(pktin.data, st->biglen);
730 st->realcrc = crc32(pktin.data, st->biglen - 4);
731 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
732 if (st->gotcrc != st->realcrc) {
733 bombout(("Incorrect CRC received on packet"));
737 pktin.body = pktin.data + st->pad + 1;
739 if (ssh1_compressing) {
740 unsigned char *decompblk;
742 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
743 &decompblk, &decomplen);
745 if (pktin.maxlen < st->pad + decomplen) {
746 pktin.maxlen = st->pad + decomplen;
747 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
748 pktin.body = pktin.data + st->pad + 1;
750 fatalbox("Out of memory");
753 memcpy(pktin.body - 1, decompblk, decomplen);
755 pktin.length = decomplen - 1;
758 pktin.type = pktin.body[-1];
760 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
761 pktin.body, pktin.length);
763 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
764 pktin.type == SSH1_SMSG_STDERR_DATA ||
765 pktin.type == SSH1_MSG_DEBUG ||
766 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
767 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
768 long strlen = GET_32BIT(pktin.body);
769 if (strlen + 4 != pktin.length) {
770 bombout(("Received data packet with bogus string length"));
775 if (pktin.type == SSH1_MSG_DEBUG) {
776 /* log debug message */
778 int strlen = GET_32BIT(pktin.body);
779 strcpy(buf, "Remote: ");
782 memcpy(buf + 8, pktin.body + 4, strlen);
783 buf[8 + strlen] = '\0';
786 } else if (pktin.type == SSH1_MSG_IGNORE) {
791 if (pktin.type == SSH1_MSG_DISCONNECT) {
792 /* log reason code in disconnect message */
794 unsigned msglen = GET_32BIT(pktin.body);
796 strcpy(buf, "Remote sent disconnect: ");
797 nowlen = strlen(buf);
798 if (msglen > sizeof(buf) - nowlen - 1)
799 msglen = sizeof(buf) - nowlen - 1;
800 memcpy(buf + nowlen, pktin.body + 4, msglen);
801 buf[nowlen + msglen] = '\0';
803 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
810 static int ssh2_rdpkt(unsigned char **data, int *datalen)
812 struct rdpkt2_state_tag *st = &rdpkt2_state;
820 st->cipherblk = sccipher->blksize;
823 if (st->cipherblk < 8)
826 if (pktin.maxlen < st->cipherblk) {
827 pktin.maxlen = st->cipherblk;
830 NULL ? smalloc(st->cipherblk +
831 APIEXTRA) : srealloc(pktin.data,
835 fatalbox("Out of memory");
839 * Acquire and decrypt the first block of the packet. This will
840 * contain the length and padding details.
842 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
843 while ((*datalen) == 0)
844 crReturn(st->cipherblk - st->i);
845 pktin.data[st->i] = *(*data)++;
850 sccipher->decrypt(pktin.data, st->cipherblk);
853 * Now get the length and padding figures.
855 st->len = GET_32BIT(pktin.data);
856 st->pad = pktin.data[4];
859 * This enables us to deduce the payload length.
861 st->payload = st->len - st->pad - 1;
863 pktin.length = st->payload + 5;
866 * So now we can work out the total packet length.
868 st->packetlen = st->len + 4;
869 st->maclen = scmac ? scmac->len : 0;
872 * Adjust memory allocation if packet is too big.
874 if (pktin.maxlen < st->packetlen + st->maclen) {
875 pktin.maxlen = st->packetlen + st->maclen;
878 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
883 fatalbox("Out of memory");
887 * Read and decrypt the remainder of the packet.
889 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
891 while ((*datalen) == 0)
892 crReturn(st->packetlen + st->maclen - st->i);
893 pktin.data[st->i] = *(*data)++;
896 /* Decrypt everything _except_ the MAC. */
898 sccipher->decrypt(pktin.data + st->cipherblk,
899 st->packetlen - st->cipherblk);
905 && !scmac->verify(pktin.data, st->len + 4,
906 st->incoming_sequence)) {
907 bombout(("Incorrect MAC received on packet"));
910 st->incoming_sequence++; /* whether or not we MACed */
913 * Decompress packet payload.
916 unsigned char *newpayload;
918 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
919 &newpayload, &newlen)) {
920 if (pktin.maxlen < newlen + 5) {
921 pktin.maxlen = newlen + 5;
924 NULL ? smalloc(pktin.maxlen +
925 APIEXTRA) : srealloc(pktin.data,
929 fatalbox("Out of memory");
931 pktin.length = 5 + newlen;
932 memcpy(pktin.data + 5, newpayload, newlen);
938 pktin.type = pktin.data[5];
940 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
941 pktin.data+6, pktin.length-6);
943 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
944 goto next_packet; /* FIXME: print DEBUG message */
946 if (pktin.type == SSH2_MSG_DISCONNECT) {
947 /* log reason code in disconnect message */
949 int reason = GET_32BIT(pktin.data + 6);
950 unsigned msglen = GET_32BIT(pktin.data + 10);
952 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
953 sprintf(buf, "Received disconnect message (%s)",
954 ssh2_disconnect_reasons[reason]);
956 sprintf(buf, "Received disconnect message (unknown type %d)",
960 strcpy(buf, "Disconnection message text: ");
961 nowlen = strlen(buf);
962 if (msglen > sizeof(buf) - nowlen - 1)
963 msglen = sizeof(buf) - nowlen - 1;
964 memcpy(buf + nowlen, pktin.data + 14, msglen);
965 buf[nowlen + msglen] = '\0';
967 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
969 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
970 ssh2_disconnect_reasons[reason] : "unknown",
978 static void ssh1_pktout_size(int len)
982 len += 5; /* type and CRC */
986 pktout.length = len - 5;
987 if (pktout.maxlen < biglen) {
988 pktout.maxlen = biglen;
990 /* Allocate enough buffer space for extra block
991 * for MS CryptEncrypt() */
992 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
993 srealloc(pktout.data, biglen + 12));
995 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
996 srealloc(pktout.data, biglen + 4));
999 fatalbox("Out of memory");
1001 pktout.body = pktout.data + 4 + pad + 1;
1004 static void s_wrpkt_start(int type, int len)
1006 ssh1_pktout_size(len);
1010 static int s_wrpkt_prepare(void)
1012 int pad, len, biglen, i;
1015 pktout.body[-1] = pktout.type;
1017 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1018 pktout.body, pktout.length);
1020 if (ssh1_compressing) {
1021 unsigned char *compblk;
1023 zlib_compress_block(pktout.body - 1, pktout.length + 1,
1024 &compblk, &complen);
1025 ssh1_pktout_size(complen - 1);
1026 memcpy(pktout.body - 1, compblk, complen);
1030 len = pktout.length + 5; /* type and CRC */
1031 pad = 8 - (len % 8);
1034 for (i = 0; i < pad; i++)
1035 pktout.data[i + 4] = random_byte();
1036 crc = crc32(pktout.data + 4, biglen - 4);
1037 PUT_32BIT(pktout.data + biglen, crc);
1038 PUT_32BIT(pktout.data, len);
1041 cipher->encrypt(pktout.data + 4, biglen);
1046 static void s_wrpkt(void)
1049 len = s_wrpkt_prepare();
1050 backlog = sk_write(s, pktout.data, len);
1051 if (backlog > SSH_MAX_BACKLOG)
1052 ssh_throttle_all(1, backlog);
1055 static void s_wrpkt_defer(void)
1058 len = s_wrpkt_prepare();
1059 if (deferred_len + len > deferred_size) {
1060 deferred_size = deferred_len + len + 128;
1061 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1063 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1064 deferred_len += len;
1068 * Construct a packet with the specified contents.
1070 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1072 unsigned char *p, *argp, argchar;
1073 unsigned long argint;
1074 int pktlen, argtype, arglen;
1078 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1081 (void) va_arg(ap1, int);
1085 (void) va_arg(ap1, char);
1089 (void) va_arg(ap1, unsigned char *);
1090 arglen = va_arg(ap1, int);
1094 argp = va_arg(ap1, unsigned char *);
1095 arglen = strlen(argp);
1096 pktlen += 4 + arglen;
1099 bn = va_arg(ap1, Bignum);
1100 pktlen += ssh1_bignum_length(bn);
1107 s_wrpkt_start(pkttype, pktlen);
1110 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1113 argint = va_arg(ap2, int);
1114 PUT_32BIT(p, argint);
1118 argchar = va_arg(ap2, unsigned char);
1123 argp = va_arg(ap2, unsigned char *);
1124 arglen = va_arg(ap2, int);
1125 memcpy(p, argp, arglen);
1129 argp = va_arg(ap2, unsigned char *);
1130 arglen = strlen(argp);
1131 PUT_32BIT(p, arglen);
1132 memcpy(p + 4, argp, arglen);
1136 bn = va_arg(ap2, Bignum);
1137 p += ssh1_write_bignum(p, bn);
1143 static void send_packet(int pkttype, ...)
1146 va_start(ap1, pkttype);
1147 va_start(ap2, pkttype);
1148 construct_packet(pkttype, ap1, ap2);
1152 static void defer_packet(int pkttype, ...)
1155 va_start(ap1, pkttype);
1156 va_start(ap2, pkttype);
1157 construct_packet(pkttype, ap1, ap2);
1161 static int ssh_versioncmp(char *a, char *b)
1164 unsigned long av, bv;
1166 av = strtoul(a, &ae, 10);
1167 bv = strtoul(b, &be, 10);
1169 return (av < bv ? -1 : +1);
1174 av = strtoul(ae, &ae, 10);
1175 bv = strtoul(be, &be, 10);
1177 return (av < bv ? -1 : +1);
1183 * Utility routines for putting an SSH-protocol `string' and
1184 * `uint32' into a SHA state.
1187 static void sha_string(SHA_State * s, void *str, int len)
1189 unsigned char lenblk[4];
1190 PUT_32BIT(lenblk, len);
1191 SHA_Bytes(s, lenblk, 4);
1192 SHA_Bytes(s, str, len);
1195 static void sha_uint32(SHA_State * s, unsigned i)
1197 unsigned char intblk[4];
1198 PUT_32BIT(intblk, i);
1199 SHA_Bytes(s, intblk, 4);
1203 * SSH2 packet construction functions.
1205 static void ssh2_pkt_ensure(int length)
1207 if (pktout.maxlen < length) {
1208 pktout.maxlen = length + 256;
1211 NULL ? smalloc(pktout.maxlen +
1212 APIEXTRA) : srealloc(pktout.data,
1216 fatalbox("Out of memory");
1219 static void ssh2_pkt_adddata(void *data, int len)
1221 pktout.length += len;
1222 ssh2_pkt_ensure(pktout.length);
1223 memcpy(pktout.data + pktout.length - len, data, len);
1225 static void ssh2_pkt_addbyte(unsigned char byte)
1227 ssh2_pkt_adddata(&byte, 1);
1229 static void ssh2_pkt_init(int pkt_type)
1232 ssh2_pkt_addbyte((unsigned char) pkt_type);
1234 static void ssh2_pkt_addbool(unsigned char value)
1236 ssh2_pkt_adddata(&value, 1);
1238 static void ssh2_pkt_adduint32(unsigned long value)
1241 PUT_32BIT(x, value);
1242 ssh2_pkt_adddata(x, 4);
1244 static void ssh2_pkt_addstring_start(void)
1246 ssh2_pkt_adduint32(0);
1247 pktout.savedpos = pktout.length;
1249 static void ssh2_pkt_addstring_str(char *data)
1251 ssh2_pkt_adddata(data, strlen(data));
1252 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1253 pktout.length - pktout.savedpos);
1255 static void ssh2_pkt_addstring_data(char *data, int len)
1257 ssh2_pkt_adddata(data, len);
1258 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1259 pktout.length - pktout.savedpos);
1261 static void ssh2_pkt_addstring(char *data)
1263 ssh2_pkt_addstring_start();
1264 ssh2_pkt_addstring_str(data);
1266 static char *ssh2_mpint_fmt(Bignum b, int *len)
1269 int i, n = (bignum_bitcount(b) + 7) / 8;
1272 fatalbox("out of memory");
1274 for (i = 1; i <= n; i++)
1275 p[i] = bignum_byte(b, n - i);
1277 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1279 memmove(p, p + i, n + 1 - i);
1283 static void ssh2_pkt_addmp(Bignum b)
1287 p = ssh2_mpint_fmt(b, &len);
1288 ssh2_pkt_addstring_start();
1289 ssh2_pkt_addstring_data(p, len);
1294 * Construct an SSH2 final-form packet: compress it, encrypt it,
1295 * put the MAC on it. Final packet, ready to be sent, is stored in
1296 * pktout.data. Total length is returned.
1298 static int ssh2_pkt_construct(void)
1300 int cipherblk, maclen, padding, i;
1301 static unsigned long outgoing_sequence = 0;
1303 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1304 pktout.data + 6, pktout.length - 6);
1307 * Compress packet payload.
1310 unsigned char *newpayload;
1312 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1313 &newpayload, &newlen)) {
1315 ssh2_pkt_adddata(newpayload, newlen);
1321 * Add padding. At least four bytes, and must also bring total
1322 * length (minus MAC) up to a multiple of the block size.
1324 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1325 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1328 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1329 maclen = csmac ? csmac->len : 0;
1330 ssh2_pkt_ensure(pktout.length + padding + maclen);
1331 pktout.data[4] = padding;
1332 for (i = 0; i < padding; i++)
1333 pktout.data[pktout.length + i] = random_byte();
1334 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1336 csmac->generate(pktout.data, pktout.length + padding,
1338 outgoing_sequence++; /* whether or not we MACed */
1341 cscipher->encrypt(pktout.data, pktout.length + padding);
1343 /* Ready-to-send packet starts at pktout.data. We return length. */
1344 return pktout.length + padding + maclen;
1348 * Construct and send an SSH2 packet immediately.
1350 static void ssh2_pkt_send(void)
1354 len = ssh2_pkt_construct();
1355 backlog = sk_write(s, pktout.data, len);
1356 if (backlog > SSH_MAX_BACKLOG)
1357 ssh_throttle_all(1, backlog);
1361 * Construct an SSH2 packet and add it to a deferred data block.
1362 * Useful for sending multiple packets in a single sk_write() call,
1363 * to prevent a traffic-analysing listener from being able to work
1364 * out the length of any particular packet (such as the password
1367 * Note that because SSH2 sequence-numbers its packets, this can
1368 * NOT be used as an m4-style `defer' allowing packets to be
1369 * constructed in one order and sent in another.
1371 static void ssh2_pkt_defer(void)
1373 int len = ssh2_pkt_construct();
1374 if (deferred_len + len > deferred_size) {
1375 deferred_size = deferred_len + len + 128;
1376 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1378 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1379 deferred_len += len;
1383 * Send the whole deferred data block constructed by
1384 * ssh2_pkt_defer() or SSH1's defer_packet().
1386 static void ssh_pkt_defersend(void)
1389 backlog = sk_write(s, deferred_send_data, deferred_len);
1390 deferred_len = deferred_size = 0;
1391 sfree(deferred_send_data);
1392 deferred_send_data = NULL;
1393 if (backlog > SSH_MAX_BACKLOG)
1394 ssh_throttle_all(1, backlog);
1398 void bndebug(char *string, Bignum b)
1402 p = ssh2_mpint_fmt(b, &len);
1403 debug(("%s", string));
1404 for (i = 0; i < len; i++)
1405 debug((" %02x", p[i]));
1411 static void sha_mpint(SHA_State * s, Bignum b)
1415 p = ssh2_mpint_fmt(b, &len);
1416 sha_string(s, p, len);
1421 * SSH2 packet decode functions.
1423 static unsigned long ssh2_pkt_getuint32(void)
1425 unsigned long value;
1426 if (pktin.length - pktin.savedpos < 4)
1427 return 0; /* arrgh, no way to decline (FIXME?) */
1428 value = GET_32BIT(pktin.data + pktin.savedpos);
1429 pktin.savedpos += 4;
1432 static int ssh2_pkt_getbool(void)
1434 unsigned long value;
1435 if (pktin.length - pktin.savedpos < 1)
1436 return 0; /* arrgh, no way to decline (FIXME?) */
1437 value = pktin.data[pktin.savedpos] != 0;
1441 static void ssh2_pkt_getstring(char **p, int *length)
1444 if (pktin.length - pktin.savedpos < 4)
1446 *length = GET_32BIT(pktin.data + pktin.savedpos);
1447 pktin.savedpos += 4;
1448 if (pktin.length - pktin.savedpos < *length)
1450 *p = pktin.data + pktin.savedpos;
1451 pktin.savedpos += *length;
1453 static Bignum ssh2_pkt_getmp(void)
1459 ssh2_pkt_getstring(&p, &length);
1463 bombout(("internal error: Can't handle negative mpints"));
1466 b = bignum_from_bytes(p, length);
1471 * Examine the remote side's version string and compare it against
1472 * a list of known buggy implementations.
1474 static void ssh_detect_bugs(char *vstring)
1476 char *imp; /* pointer to implementation part */
1478 imp += strcspn(imp, "-");
1480 imp += strcspn(imp, "-");
1483 ssh_remote_bugs = 0;
1485 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1486 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1487 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
1489 * These versions don't support SSH1_MSG_IGNORE, so we have
1490 * to use a different defence against password length
1493 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1494 logevent("We believe remote version has SSH1 ignore bug");
1497 if (!strcmp(imp, "Cisco-1.25")) {
1499 * These versions need a plain password sent; they can't
1500 * handle having a null and a random length of data after
1503 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1504 logevent("We believe remote version needs a plain SSH1 password");
1507 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1508 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1509 !strncmp(imp, "2.1 ", 4)) {
1511 * These versions have the HMAC bug.
1513 ssh_remote_bugs |= BUG_SSH2_HMAC;
1514 logevent("We believe remote version has SSH2 HMAC bug");
1518 static int do_ssh_init(unsigned char c)
1521 static char version[10];
1522 static char *vstring;
1523 static int vstrsize;
1529 /* Search for the string "SSH-" in the input. */
1532 static const int transS[] = { 1, 2, 2, 1 };
1533 static const int transH[] = { 0, 0, 3, 0 };
1534 static const int transminus[] = { 0, 0, 0, -1 };
1545 crReturn(1); /* get another character */
1549 vstring = smalloc(vstrsize);
1550 strcpy(vstring, "SSH-");
1554 crReturn(1); /* get another char */
1555 if (vslen >= vstrsize - 1) {
1557 vstring = srealloc(vstring, vstrsize);
1559 vstring[vslen++] = c;
1564 } else if (i < sizeof(version) - 1)
1566 } else if (c == '\n')
1570 ssh_agentfwd_enabled = FALSE;
1571 rdpkt2_state.incoming_sequence = 0;
1574 vlog = smalloc(20 + vslen);
1575 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
1576 sprintf(vlog, "Server version: %s", vstring);
1578 ssh_detect_bugs(vstring);
1582 * Server version "1.99" means we can choose whether we use v1
1583 * or v2 protocol. Choice is based on cfg.sshprot.
1585 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1587 * This is a v2 server. Begin v2 protocol.
1589 char verstring[80], vlog[100];
1590 sprintf(verstring, "SSH-2.0-%s", sshver);
1591 SHA_Init(&exhashbase);
1593 * Hash our version string and their version string.
1595 sha_string(&exhashbase, verstring, strlen(verstring));
1596 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1597 sprintf(vlog, "We claim version: %s", verstring);
1599 strcat(verstring, "\n");
1600 logevent("Using SSH protocol version 2");
1601 sk_write(s, verstring, strlen(verstring));
1602 ssh_protocol = ssh2_protocol;
1604 s_rdpkt = ssh2_rdpkt;
1607 * This is a v1 server. Begin v1 protocol.
1609 char verstring[80], vlog[100];
1610 sprintf(verstring, "SSH-%s-%s",
1611 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1613 sprintf(vlog, "We claim version: %s", verstring);
1615 strcat(verstring, "\n");
1616 logevent("Using SSH protocol version 1");
1617 sk_write(s, verstring, strlen(verstring));
1618 ssh_protocol = ssh1_protocol;
1620 s_rdpkt = ssh1_rdpkt;
1622 ssh_state = SSH_STATE_BEFORE_SIZE;
1629 static void ssh_gotdata(unsigned char *data, int datalen)
1634 * To begin with, feed the characters one by one to the
1635 * protocol initialisation / selection function do_ssh_init().
1636 * When that returns 0, we're done with the initial greeting
1637 * exchange and can move on to packet discipline.
1642 crReturnV; /* more data please */
1643 ret = do_ssh_init(*data);
1651 * We emerge from that loop when the initial negotiation is
1652 * over and we have selected an s_rdpkt function. Now pass
1653 * everything to s_rdpkt, and then pass the resulting packets
1654 * to the proper protocol handler.
1659 while (datalen > 0) {
1660 if (s_rdpkt(&data, &datalen) == 0) {
1661 if (ssh_state == SSH_STATE_CLOSED) {
1664 ssh_protocol(NULL, 0, 1);
1665 if (ssh_state == SSH_STATE_CLOSED) {
1675 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1678 ssh_state = SSH_STATE_CLOSED;
1684 /* A socket error has occurred. */
1685 connection_fatal(error_msg);
1687 /* Otherwise, the remote side closed the connection normally. */
1692 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1694 ssh_gotdata(data, len);
1695 if (ssh_state == SSH_STATE_CLOSED) {
1705 static void ssh_sent(Plug plug, int bufsize)
1708 * If the send backlog on the SSH socket itself clears, we
1709 * should unthrottle the whole world if it was throttled.
1711 if (bufsize < SSH_MAX_BACKLOG)
1712 ssh_throttle_all(0, bufsize);
1716 * Connect to specified host and port.
1717 * Returns an error message, or NULL on success.
1718 * Also places the canonical host name into `realhost'. It must be
1719 * freed by the caller.
1721 static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
1723 static struct plug_function_table fn_table = {
1728 }, *fn_table_ptr = &fn_table;
1737 savedhost = smalloc(1 + strlen(host));
1739 fatalbox("Out of memory");
1740 strcpy(savedhost, host);
1743 port = 22; /* default ssh port */
1758 sprintf(buf, "Looking up host \"%.170s\"", host);
1761 addr = sk_namelookup(host, realhost);
1762 if ((err = sk_addr_error(addr)))
1766 *realhost = strdup(FWhost);
1773 char buf[200], addrbuf[100];
1774 sk_getaddr(addr, addrbuf, 100);
1775 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1778 s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
1779 if ((err = sk_socket_error(s)))
1783 sk_write(s, "connect ", 8);
1784 sk_write(s, FWhost, strlen(FWhost));
1787 sprintf(buf, " %d\n", FWport);
1788 sk_write(s, buf, strlen(buf));
1796 * Throttle or unthrottle the SSH connection.
1798 static void ssh1_throttle(int adjust)
1800 int old_count = ssh1_throttle_count;
1801 ssh1_throttle_count += adjust;
1802 assert(ssh1_throttle_count >= 0);
1803 if (ssh1_throttle_count && !old_count) {
1804 sk_set_frozen(s, 1);
1805 } else if (!ssh1_throttle_count && old_count) {
1806 sk_set_frozen(s, 0);
1811 * Throttle or unthrottle _all_ local data streams (for when sends
1812 * on the SSH connection itself back up).
1814 static void ssh_throttle_all(int enable, int bufsize)
1817 struct ssh_channel *c;
1819 if (enable == ssh_throttled_all)
1821 ssh_throttled_all = enable;
1822 ssh_overall_bufsize = bufsize;
1825 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1827 case CHAN_MAINSESSION:
1829 * This is treated separately, outside the switch.
1833 x11_override_throttle(c->u.x11.s, enable);
1836 /* Agent channels require no buffer management. */
1839 pfd_override_throttle(c->u.x11.s, enable);
1846 * Handle the key exchange and user authentication phases.
1848 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1852 static unsigned char *rsabuf, *keystr1, *keystr2;
1853 unsigned char cookie[8];
1854 struct RSAKey servkey, hostkey;
1855 struct MD5Context md5c;
1856 static unsigned long supported_ciphers_mask, supported_auths_mask;
1857 static int tried_publickey, tried_agent;
1858 static int tis_auth_refused, ccard_auth_refused;
1859 static unsigned char session_id[16];
1860 static int cipher_type;
1861 static char username[100];
1862 static void *publickey_blob;
1863 int publickey_bloblen;
1870 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1871 bombout(("Public key packet not received"));
1875 logevent("Received public keys");
1877 memcpy(cookie, pktin.body, 8);
1879 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1880 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1883 * Log the host key fingerprint.
1887 logevent("Host key fingerprint is:");
1888 strcpy(logmsg, " ");
1889 hostkey.comment = NULL;
1890 rsa_fingerprint(logmsg + strlen(logmsg),
1891 sizeof(logmsg) - strlen(logmsg), &hostkey);
1895 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1896 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1897 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1899 ssh1_local_protoflags =
1900 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1901 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1904 MD5Update(&md5c, keystr2, hostkey.bytes);
1905 MD5Update(&md5c, keystr1, servkey.bytes);
1906 MD5Update(&md5c, pktin.body, 8);
1907 MD5Final(session_id, &md5c);
1909 for (i = 0; i < 32; i++)
1910 session_key[i] = random_byte();
1912 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1914 rsabuf = smalloc(len);
1916 fatalbox("Out of memory");
1919 * Verify the host key.
1923 * First format the key into a string.
1925 int len = rsastr_len(&hostkey);
1926 char fingerprint[100];
1927 char *keystr = smalloc(len);
1929 fatalbox("Out of memory");
1930 rsastr_fmt(keystr, &hostkey);
1931 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1932 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1937 for (i = 0; i < 32; i++) {
1938 rsabuf[i] = session_key[i];
1940 rsabuf[i] ^= session_id[i];
1943 if (hostkey.bytes > servkey.bytes) {
1944 rsaencrypt(rsabuf, 32, &servkey);
1945 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1947 rsaencrypt(rsabuf, 32, &hostkey);
1948 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1951 logevent("Encrypted session key");
1954 int cipher_chosen = 0, warn = 0;
1955 char *cipher_string = NULL;
1956 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
1957 int next_cipher = cfg.ssh_cipherlist[i];
1958 if (next_cipher == CIPHER_WARN) {
1959 /* If/when we choose a cipher, warn about it */
1961 } else if (next_cipher == CIPHER_AES) {
1962 /* XXX Probably don't need to mention this. */
1963 logevent("AES not supported in SSH1, skipping");
1965 switch (next_cipher) {
1966 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
1967 cipher_string = "3DES"; break;
1968 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
1969 cipher_string = "Blowfish"; break;
1970 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
1971 cipher_string = "single-DES"; break;
1973 if (supported_ciphers_mask & (1 << cipher_type))
1977 if (!cipher_chosen) {
1978 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
1979 bombout(("Server violates SSH 1 protocol by not "
1980 "supporting 3DES encryption"));
1982 /* shouldn't happen */
1983 bombout(("No supported ciphers found"));
1987 /* Warn about chosen cipher if necessary. */
1989 askcipher(cipher_string, 0);
1992 switch (cipher_type) {
1993 case SSH_CIPHER_3DES:
1994 logevent("Using 3DES encryption");
1996 case SSH_CIPHER_DES:
1997 logevent("Using single-DES encryption");
1999 case SSH_CIPHER_BLOWFISH:
2000 logevent("Using Blowfish encryption");
2004 send_packet(SSH1_CMSG_SESSION_KEY,
2005 PKT_CHAR, cipher_type,
2006 PKT_DATA, cookie, 8,
2007 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2008 PKT_DATA, rsabuf, len,
2009 PKT_INT, ssh1_local_protoflags, PKT_END);
2011 logevent("Trying to enable encryption...");
2015 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2016 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
2017 cipher->sesskey(session_key);
2021 if (pktin.type != SSH1_SMSG_SUCCESS) {
2022 bombout(("Encryption not successfully enabled"));
2026 logevent("Successfully started encryption");
2032 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2034 if (!ssh_get_line("login as: ",
2035 username, sizeof(username), FALSE)) {
2037 * get_line failed to get a username.
2040 logevent("No username provided. Abandoning session.");
2041 ssh_state = SSH_STATE_CLOSED;
2045 c_write_str("login as: ");
2048 crWaitUntil(!ispkt);
2050 switch (c = *in++) {
2059 c_write_str("\b \b");
2066 c_write_str("\b \b");
2076 if (((c >= ' ' && c <= '~') ||
2077 ((unsigned char) c >= 160))
2078 && pos < sizeof(username)-1) {
2079 username[pos++] = c;
2085 c_write_str("\r\n");
2086 username[strcspn(username, "\n\r")] = '\0';
2089 strncpy(username, cfg.username, 99);
2090 username[99] = '\0';
2093 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2095 char userlog[22 + sizeof(username)];
2096 sprintf(userlog, "Sent username \"%s\"", username);
2098 if (flags & FLAG_INTERACTIVE &&
2099 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2100 strcat(userlog, "\r\n");
2101 c_write_str(userlog);
2108 tried_publickey = tried_agent = 0;
2109 tis_auth_refused = ccard_auth_refused = 0;
2110 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2112 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2113 publickey_blob = NULL;
2115 publickey_blob = NULL;
2117 while (pktin.type == SSH1_SMSG_FAILURE) {
2118 static char password[100];
2119 static char prompt[200];
2122 static int pwpkt_type;
2123 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2125 if (agent_exists() && !tried_agent) {
2127 * Attempt RSA authentication using Pageant.
2129 static unsigned char request[5], *response, *p;
2130 static int responselen;
2131 static int i, nkeys;
2132 static int authed = FALSE;
2136 logevent("Pageant is running. Requesting keys.");
2138 /* Request the keys held by the agent. */
2139 PUT_32BIT(request, 1);
2140 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2141 agent_query(request, 5, &r, &responselen);
2142 response = (unsigned char *) r;
2143 if (response && responselen >= 5 &&
2144 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2146 nkeys = GET_32BIT(p);
2150 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2153 for (i = 0; i < nkeys; i++) {
2154 static struct RSAKey key;
2155 static Bignum challenge;
2156 static char *commentp;
2157 static int commentlen;
2161 sprintf(buf, "Trying Pageant key #%d", i);
2164 if (publickey_blob &&
2165 !memcmp(p, publickey_blob, publickey_bloblen)) {
2166 logevent("This key matches configured key file");
2167 tried_publickey = 1;
2170 p += ssh1_read_bignum(p, &key.exponent);
2171 p += ssh1_read_bignum(p, &key.modulus);
2172 commentlen = GET_32BIT(p);
2176 send_packet(SSH1_CMSG_AUTH_RSA,
2177 PKT_BIGNUM, key.modulus, PKT_END);
2179 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2180 logevent("Key refused");
2183 logevent("Received RSA challenge");
2184 ssh1_read_bignum(pktin.body, &challenge);
2186 char *agentreq, *q, *ret;
2189 len = 1 + 4; /* message type, bit count */
2190 len += ssh1_bignum_length(key.exponent);
2191 len += ssh1_bignum_length(key.modulus);
2192 len += ssh1_bignum_length(challenge);
2193 len += 16; /* session id */
2194 len += 4; /* response format */
2195 agentreq = smalloc(4 + len);
2196 PUT_32BIT(agentreq, len);
2198 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2199 PUT_32BIT(q, bignum_bitcount(key.modulus));
2201 q += ssh1_write_bignum(q, key.exponent);
2202 q += ssh1_write_bignum(q, key.modulus);
2203 q += ssh1_write_bignum(q, challenge);
2204 memcpy(q, session_id, 16);
2206 PUT_32BIT(q, 1); /* response format */
2207 agent_query(agentreq, len + 4, &vret, &retlen);
2211 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2212 logevent("Sending Pageant's response");
2213 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2214 PKT_DATA, ret + 5, 16,
2218 if (pktin.type == SSH1_SMSG_SUCCESS) {
2220 ("Pageant's response accepted");
2221 if (flags & FLAG_VERBOSE) {
2223 ("Authenticated using RSA key \"");
2224 c_write(commentp, commentlen);
2225 c_write_str("\" from agent\r\n");
2230 ("Pageant's response not accepted");
2233 ("Pageant failed to answer challenge");
2237 logevent("No reply received from Pageant");
2240 freebn(key.exponent);
2241 freebn(key.modulus);
2250 if (*cfg.keyfile && !tried_publickey)
2251 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2253 if (cfg.try_tis_auth &&
2254 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2255 !tis_auth_refused) {
2256 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2257 logevent("Requested TIS authentication");
2258 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2260 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2261 logevent("TIS authentication declined");
2262 if (flags & FLAG_INTERACTIVE)
2263 c_write_str("TIS authentication refused.\r\n");
2264 tis_auth_refused = 1;
2267 int challengelen = ((pktin.body[0] << 24) |
2268 (pktin.body[1] << 16) |
2269 (pktin.body[2] << 8) |
2271 logevent("Received TIS challenge");
2272 if (challengelen > sizeof(prompt) - 1)
2273 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2274 memcpy(prompt, pktin.body + 4, challengelen);
2275 /* Prompt heuristic comes from OpenSSH */
2276 strncpy(prompt + challengelen,
2277 memchr(prompt, '\n', challengelen) ?
2278 "": "\r\nResponse: ",
2279 (sizeof prompt) - challengelen);
2280 prompt[(sizeof prompt) - 1] = '\0';
2283 if (cfg.try_tis_auth &&
2284 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2285 !ccard_auth_refused) {
2286 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2287 logevent("Requested CryptoCard authentication");
2288 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2290 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2291 logevent("CryptoCard authentication declined");
2292 c_write_str("CryptoCard authentication refused.\r\n");
2293 ccard_auth_refused = 1;
2296 int challengelen = ((pktin.body[0] << 24) |
2297 (pktin.body[1] << 16) |
2298 (pktin.body[2] << 8) |
2300 logevent("Received CryptoCard challenge");
2301 if (challengelen > sizeof(prompt) - 1)
2302 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2303 memcpy(prompt, pktin.body + 4, challengelen);
2304 strncpy(prompt + challengelen,
2305 memchr(prompt, '\n', challengelen) ?
2306 "" : "\r\nResponse: ",
2307 sizeof(prompt) - challengelen);
2308 prompt[sizeof(prompt) - 1] = '\0';
2311 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2312 sprintf(prompt, "%.90s@%.90s's password: ",
2313 username, savedhost);
2315 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2316 char *comment = NULL;
2317 if (flags & FLAG_VERBOSE)
2318 c_write_str("Trying public key authentication.\r\n");
2319 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2320 if (flags & FLAG_VERBOSE)
2321 c_write_str("No passphrase required.\r\n");
2324 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2329 * Show password prompt, having first obtained it via a TIS
2330 * or CryptoCard exchange if we're doing TIS or CryptoCard
2334 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2336 * get_line failed to get a password (for example
2337 * because one was supplied on the command line
2338 * which has already failed to work). Terminate.
2340 send_packet(SSH1_MSG_DISCONNECT,
2341 PKT_STR, "No more passwords available to try",
2343 connection_fatal("Unable to authenticate");
2344 ssh_state = SSH_STATE_CLOSED;
2348 /* Prompt may have come from server. We've munged it a bit, so
2349 * we know it to be zero-terminated at least once. */
2350 c_write_untrusted(prompt, strlen(prompt));
2354 crWaitUntil(!ispkt);
2356 switch (c = *in++) {
2377 if (pos < sizeof(password)-1)
2378 password[pos++] = c;
2382 c_write_str("\r\n");
2386 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2388 * Try public key authentication with the specified
2391 static struct RSAKey pubkey;
2392 static Bignum challenge, response;
2394 static unsigned char buffer[32];
2396 tried_publickey = 1;
2397 i = loadrsakey(cfg.keyfile, &pubkey, password);
2399 c_write_str("Couldn't load private key from ");
2400 c_write_str(cfg.keyfile);
2401 c_write_str(".\r\n");
2402 continue; /* go and try password */
2405 c_write_str("Wrong passphrase.\r\n");
2406 tried_publickey = 0;
2407 continue; /* try again */
2411 * Send a public key attempt.
2413 send_packet(SSH1_CMSG_AUTH_RSA,
2414 PKT_BIGNUM, pubkey.modulus, PKT_END);
2417 if (pktin.type == SSH1_SMSG_FAILURE) {
2418 c_write_str("Server refused our public key.\r\n");
2419 continue; /* go and try password */
2421 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2422 bombout(("Bizarre response to offer of public key"));
2425 ssh1_read_bignum(pktin.body, &challenge);
2426 response = rsadecrypt(challenge, &pubkey);
2427 freebn(pubkey.private_exponent); /* burn the evidence */
2429 for (i = 0; i < 32; i++) {
2430 buffer[i] = bignum_byte(response, 31 - i);
2434 MD5Update(&md5c, buffer, 32);
2435 MD5Update(&md5c, session_id, 16);
2436 MD5Final(buffer, &md5c);
2438 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2439 PKT_DATA, buffer, 16, PKT_END);
2442 if (pktin.type == SSH1_SMSG_FAILURE) {
2443 if (flags & FLAG_VERBOSE)
2445 ("Failed to authenticate with our public key.\r\n");
2446 continue; /* go and try password */
2447 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2449 ("Bizarre response to RSA authentication response"));
2453 break; /* we're through! */
2455 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2457 * Defence against traffic analysis: we send a
2458 * whole bunch of packets containing strings of
2459 * different lengths. One of these strings is the
2460 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2461 * The others are all random data in
2462 * SSH1_MSG_IGNORE packets. This way a passive
2463 * listener can't tell which is the password, and
2464 * hence can't deduce the password length.
2466 * Anybody with a password length greater than 16
2467 * bytes is going to have enough entropy in their
2468 * password that a listener won't find it _that_
2469 * much help to know how long it is. So what we'll
2472 * - if password length < 16, we send 15 packets
2473 * containing string lengths 1 through 15
2475 * - otherwise, we let N be the nearest multiple
2476 * of 8 below the password length, and send 8
2477 * packets containing string lengths N through
2478 * N+7. This won't obscure the order of
2479 * magnitude of the password length, but it will
2480 * introduce a bit of extra uncertainty.
2482 * A few servers (the old 1.2.18 through 1.2.22)
2483 * can't deal with SSH1_MSG_IGNORE. For these
2484 * servers, we need an alternative defence. We make
2485 * use of the fact that the password is interpreted
2486 * as a C string: so we can append a NUL, then some
2489 * One server (a Cisco one) can deal with neither
2490 * SSH1_MSG_IGNORE _nor_ a padded password string.
2491 * For this server we are left with no defences
2492 * against password length sniffing.
2494 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2496 * The server can deal with SSH1_MSG_IGNORE, so
2497 * we can use the primary defence.
2499 int bottom, top, pwlen, i;
2502 pwlen = strlen(password);
2504 bottom = 0; /* zero length passwords are OK! :-) */
2507 bottom = pwlen & ~7;
2511 assert(pwlen >= bottom && pwlen <= top);
2513 randomstr = smalloc(top + 1);
2515 for (i = bottom; i <= top; i++) {
2517 defer_packet(pwpkt_type, PKT_STR, password,
2520 for (j = 0; j < i; j++) {
2522 randomstr[j] = random_byte();
2523 } while (randomstr[j] == '\0');
2525 randomstr[i] = '\0';
2526 defer_packet(SSH1_MSG_IGNORE,
2527 PKT_STR, randomstr, PKT_END);
2530 logevent("Sending password with camouflage packets");
2531 ssh_pkt_defersend();
2533 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2535 * The server can't deal with SSH1_MSG_IGNORE
2536 * but can deal with padded passwords, so we
2537 * can use the secondary defence.
2543 len = strlen(password);
2544 if (len < sizeof(string)) {
2546 strcpy(string, password);
2547 len++; /* cover the zero byte */
2548 while (len < sizeof(string)) {
2549 string[len++] = (char) random_byte();
2554 logevent("Sending length-padded password");
2555 send_packet(pwpkt_type, PKT_INT, len,
2556 PKT_DATA, s, len, PKT_END);
2559 * The server has _both_
2560 * BUG_CHOKES_ON_SSH1_IGNORE and
2561 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2562 * therefore nothing we can do.
2565 len = strlen(password);
2566 logevent("Sending unpadded password");
2567 send_packet(pwpkt_type, PKT_INT, len,
2568 PKT_DATA, password, len, PKT_END);
2571 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2574 logevent("Sent password");
2575 memset(password, 0, strlen(password));
2577 if (pktin.type == SSH1_SMSG_FAILURE) {
2578 if (flags & FLAG_VERBOSE)
2579 c_write_str("Access denied\r\n");
2580 logevent("Authentication refused");
2581 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2582 logevent("Received disconnect request");
2583 ssh_state = SSH_STATE_CLOSED;
2585 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2586 bombout(("Strange packet received, type %d", pktin.type));
2591 logevent("Authentication successful");
2596 void sshfwd_close(struct ssh_channel *c)
2598 if (c && !c->closes) {
2600 * If the channel's remoteid is -1, we have sent
2601 * CHANNEL_OPEN for this channel, but it hasn't even been
2602 * acknowledged by the server. So we must set a close flag
2603 * on it now, and then when the server acks the channel
2604 * open, we can close it then.
2606 if (c->remoteid != -1) {
2607 if (ssh_version == 1) {
2608 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2611 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2612 ssh2_pkt_adduint32(c->remoteid);
2617 if (c->type == CHAN_X11) {
2619 logevent("Forwarded X11 connection terminated");
2620 } else if (c->type == CHAN_SOCKDATA ||
2621 c->type == CHAN_SOCKDATA_DORMANT) {
2623 logevent("Forwarded port closed");
2628 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2630 if (ssh_version == 1) {
2631 send_packet(SSH1_MSG_CHANNEL_DATA,
2632 PKT_INT, c->remoteid,
2633 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2635 * In SSH1 we can return 0 here - implying that forwarded
2636 * connections are never individually throttled - because
2637 * the only circumstance that can cause throttling will be
2638 * the whole SSH connection backing up, in which case
2639 * _everything_ will be throttled as a whole.
2643 ssh2_add_channel_data(c, buf, len);
2644 return ssh2_try_send(c);
2648 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2650 if (ssh_version == 1) {
2651 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2652 c->v.v1.throttling = 0;
2656 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2660 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2666 while (!do_ssh1_login(in, inlen, ispkt)) {
2669 if (ssh_state == SSH_STATE_CLOSED)
2672 if (cfg.agentfwd && agent_exists()) {
2673 logevent("Requesting agent forwarding");
2674 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2678 if (pktin.type != SSH1_SMSG_SUCCESS
2679 && pktin.type != SSH1_SMSG_FAILURE) {
2680 bombout(("Protocol confusion"));
2682 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2683 logevent("Agent forwarding refused");
2685 logevent("Agent forwarding enabled");
2686 ssh_agentfwd_enabled = TRUE;
2690 if (cfg.x11_forward) {
2691 char proto[20], data[64];
2692 logevent("Requesting X11 forwarding");
2693 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2694 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2695 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2696 PKT_STR, proto, PKT_STR, data,
2697 PKT_INT, 0, PKT_END);
2699 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2700 PKT_STR, proto, PKT_STR, data, PKT_END);
2705 if (pktin.type != SSH1_SMSG_SUCCESS
2706 && pktin.type != SSH1_SMSG_FAILURE) {
2707 bombout(("Protocol confusion"));
2709 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2710 logevent("X11 forwarding refused");
2712 logevent("X11 forwarding enabled");
2713 ssh_X11_fwd_enabled = TRUE;
2721 char sports[256], dports[256], host[256];
2724 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2725 /* Add port forwardings. */
2730 while (*e && *e != '\t')
2736 while (*e && *e != ':')
2746 dport = atoi(dports);
2747 sport = atoi(sports);
2748 if (sport && dport) {
2750 pfd_addforward(host, dport, sport);
2751 sprintf(buf, "Local port %d forwarding to %s:%d",
2752 sport, host, dport);
2755 struct ssh_rportfwd *pf;
2756 pf = smalloc(sizeof(*pf));
2757 strcpy(pf->dhost, host);
2759 if (add234(ssh_rportfwds, pf) != pf) {
2761 "Duplicate remote port forwarding to %s:%d",
2766 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2767 sport, host, dport);
2769 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2781 send_packet(SSH1_CMSG_REQUEST_PTY,
2782 PKT_STR, cfg.termtype,
2783 PKT_INT, rows, PKT_INT, cols,
2784 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2785 ssh_state = SSH_STATE_INTERMED;
2789 if (pktin.type != SSH1_SMSG_SUCCESS
2790 && pktin.type != SSH1_SMSG_FAILURE) {
2791 bombout(("Protocol confusion"));
2793 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2794 c_write_str("Server refused to allocate pty\r\n");
2795 ssh_editing = ssh_echoing = 1;
2797 logevent("Allocated pty");
2799 ssh_editing = ssh_echoing = 1;
2802 if (cfg.compression) {
2803 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2807 if (pktin.type != SSH1_SMSG_SUCCESS
2808 && pktin.type != SSH1_SMSG_FAILURE) {
2809 bombout(("Protocol confusion"));
2811 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2812 c_write_str("Server refused to compress\r\n");
2814 logevent("Started compression");
2815 ssh1_compressing = TRUE;
2816 zlib_compress_init();
2817 zlib_decompress_init();
2821 * Start the shell or command.
2823 * Special case: if the first-choice command is an SSH2
2824 * subsystem (hence not usable here) and the second choice
2825 * exists, we fall straight back to that.
2828 char *cmd = cfg.remote_cmd_ptr;
2830 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2831 cmd = cfg.remote_cmd_ptr2;
2832 ssh_fallback_cmd = TRUE;
2835 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2837 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2838 logevent("Started session");
2841 ssh_state = SSH_STATE_SESSION;
2845 ssh_special(TS_EOF);
2847 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
2849 ssh_channels = newtree234(ssh_channelcmp);
2853 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2854 pktin.type == SSH1_SMSG_STDERR_DATA) {
2855 long len = GET_32BIT(pktin.body);
2857 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2858 pktin.body + 4, len);
2859 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
2860 ssh1_stdout_throttling = 1;
2863 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2864 ssh_state = SSH_STATE_CLOSED;
2865 logevent("Received disconnect request");
2867 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2868 /* Remote side is trying to open a channel to talk to our
2869 * X-Server. Give them back a local channel number. */
2870 struct ssh_channel *c;
2872 logevent("Received X11 connect request");
2873 /* Refuse if X11 forwarding is disabled. */
2874 if (!ssh_X11_fwd_enabled) {
2875 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2876 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2877 logevent("Rejected X11 connect request");
2879 c = smalloc(sizeof(struct ssh_channel));
2881 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2882 logevent("opening X11 forward connection failed");
2884 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2885 PKT_INT, GET_32BIT(pktin.body),
2889 ("opening X11 forward connection succeeded");
2890 c->remoteid = GET_32BIT(pktin.body);
2891 c->localid = alloc_channel_id();
2893 c->v.v1.throttling = 0;
2894 c->type = CHAN_X11; /* identify channel type */
2895 add234(ssh_channels, c);
2896 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2897 PKT_INT, c->remoteid, PKT_INT,
2898 c->localid, PKT_END);
2899 logevent("Opened X11 forward channel");
2902 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2903 /* Remote side is trying to open a channel to talk to our
2904 * agent. Give them back a local channel number. */
2905 struct ssh_channel *c;
2907 /* Refuse if agent forwarding is disabled. */
2908 if (!ssh_agentfwd_enabled) {
2909 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2910 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2912 c = smalloc(sizeof(struct ssh_channel));
2913 c->remoteid = GET_32BIT(pktin.body);
2914 c->localid = alloc_channel_id();
2916 c->v.v1.throttling = 0;
2917 c->type = CHAN_AGENT; /* identify channel type */
2918 c->u.a.lensofar = 0;
2919 add234(ssh_channels, c);
2920 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2921 PKT_INT, c->remoteid, PKT_INT, c->localid,
2924 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2925 /* Remote side is trying to open a channel to talk to a
2926 * forwarded port. Give them back a local channel number. */
2927 struct ssh_channel *c;
2928 struct ssh_rportfwd pf;
2930 char host[256], buf[1024];
2932 c = smalloc(sizeof(struct ssh_channel));
2934 hostsize = GET_32BIT(pktin.body+4);
2935 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2936 if (h+1 < host+sizeof(host))
2941 port = GET_32BIT(p);
2943 strcpy(pf.dhost, host);
2946 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2947 sprintf(buf, "Rejected remote port open request for %s:%d",
2950 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2951 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2953 sprintf(buf, "Received remote port open request for %s:%d",
2956 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2959 sprintf(buf, "Port open failed: %s", e);
2962 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2963 PKT_INT, GET_32BIT(pktin.body),
2966 c->remoteid = GET_32BIT(pktin.body);
2967 c->localid = alloc_channel_id();
2969 c->v.v1.throttling = 0;
2970 c->type = CHAN_SOCKDATA; /* identify channel type */
2971 add234(ssh_channels, c);
2972 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2973 PKT_INT, c->remoteid, PKT_INT,
2974 c->localid, PKT_END);
2975 logevent("Forwarded port opened successfully");
2979 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2980 unsigned int remoteid = GET_32BIT(pktin.body);
2981 unsigned int localid = GET_32BIT(pktin.body+4);
2982 struct ssh_channel *c;
2984 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2985 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2986 c->remoteid = localid;
2987 c->type = CHAN_SOCKDATA;
2988 c->v.v1.throttling = 0;
2989 pfd_confirm(c->u.pfd.s);
2992 if (c && c->closes) {
2994 * We have a pending close on this channel,
2995 * which we decided on before the server acked
2996 * the channel open. So now we know the
2997 * remoteid, we can close it again.
2999 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3003 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3004 unsigned int remoteid = GET_32BIT(pktin.body);
3005 unsigned int localid = GET_32BIT(pktin.body+4);
3006 struct ssh_channel *c;
3008 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3009 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3010 logevent("Forwarded connection refused by server");
3011 pfd_close(c->u.pfd.s);
3012 del234(ssh_channels, c);
3016 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3017 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3018 /* Remote side closes a channel. */
3019 unsigned i = GET_32BIT(pktin.body);
3020 struct ssh_channel *c;
3021 c = find234(ssh_channels, &i, ssh_channelfind);
3025 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3026 if (!(c->closes & closetype))
3027 send_packet(pktin.type, PKT_INT, c->remoteid,
3029 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3030 logevent("Forwarded X11 connection terminated");
3031 assert(c->u.x11.s != NULL);
3032 x11_close(c->u.x11.s);
3035 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3036 logevent("Forwarded port closed");
3037 assert(c->u.pfd.s != NULL);
3038 pfd_close(c->u.pfd.s);
3041 c->closes |= closetype;
3042 if (c->closes == 3) {
3043 del234(ssh_channels, c);
3047 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3048 /* Data sent down one of our channels. */
3049 int i = GET_32BIT(pktin.body);
3050 int len = GET_32BIT(pktin.body + 4);
3051 unsigned char *p = pktin.body + 8;
3052 struct ssh_channel *c;
3053 c = find234(ssh_channels, &i, ssh_channelfind);
3058 bufsize = x11_send(c->u.x11.s, p, len);
3061 bufsize = pfd_send(c->u.pfd.s, p, len);
3064 /* Data for an agent message. Buffer it. */
3066 if (c->u.a.lensofar < 4) {
3067 int l = min(4 - c->u.a.lensofar, len);
3068 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3072 c->u.a.lensofar += l;
3074 if (c->u.a.lensofar == 4) {
3076 4 + GET_32BIT(c->u.a.msglen);
3077 c->u.a.message = smalloc(c->u.a.totallen);
3078 memcpy(c->u.a.message, c->u.a.msglen, 4);
3080 if (c->u.a.lensofar >= 4 && len > 0) {
3082 min(c->u.a.totallen - c->u.a.lensofar,
3084 memcpy(c->u.a.message + c->u.a.lensofar, p,
3088 c->u.a.lensofar += l;
3090 if (c->u.a.lensofar == c->u.a.totallen) {
3091 void *reply, *sentreply;
3093 agent_query(c->u.a.message,
3094 c->u.a.totallen, &reply,
3099 /* Fake SSH_AGENT_FAILURE. */
3100 sentreply = "\0\0\0\1\5";
3103 send_packet(SSH1_MSG_CHANNEL_DATA,
3104 PKT_INT, c->remoteid,
3106 PKT_DATA, sentreply, replylen,
3110 sfree(c->u.a.message);
3111 c->u.a.lensofar = 0;
3114 bufsize = 0; /* agent channels never back up */
3117 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3118 c->v.v1.throttling = 1;
3122 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3123 /* may be from EXEC_SHELL on some servers */
3124 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3125 /* may be from EXEC_SHELL on some servers
3126 * if no pty is available or in other odd cases. Ignore */
3127 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3129 ssh_exitcode = GET_32BIT(pktin.body);
3130 sprintf(buf, "Server sent command exit status %d",
3133 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3135 * In case `helpful' firewalls or proxies tack
3136 * extra human-readable text on the end of the
3137 * session which we might mistake for another
3138 * encrypted packet, we close the session once
3139 * we've sent EXIT_CONFIRMATION.
3141 ssh_state = SSH_STATE_CLOSED;
3144 bombout(("Strange packet received: type %d", pktin.type));
3149 int len = min(inlen, 512);
3150 send_packet(SSH1_CMSG_STDIN_DATA,
3151 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3162 * Utility routine for decoding comma-separated strings in KEXINIT.
3164 static int in_commasep_string(char *needle, char *haystack, int haylen)
3166 int needlen = strlen(needle);
3169 * Is it at the start of the string?
3171 if (haylen >= needlen && /* haystack is long enough */
3172 !memcmp(needle, haystack, needlen) && /* initial match */
3173 (haylen == needlen || haystack[needlen] == ',')
3174 /* either , or EOS follows */
3178 * If not, search for the next comma and resume after that.
3179 * If no comma found, terminate.
3181 while (haylen > 0 && *haystack != ',')
3182 haylen--, haystack++;
3185 haylen--, haystack++; /* skip over comma itself */
3190 * SSH2 key creation method.
3192 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3196 /* First 20 bytes. */
3199 SHA_Bytes(&s, H, 20);
3200 SHA_Bytes(&s, &chr, 1);
3201 SHA_Bytes(&s, sessid, 20);
3202 SHA_Final(&s, keyspace);
3203 /* Next 20 bytes. */
3206 SHA_Bytes(&s, H, 20);
3207 SHA_Bytes(&s, keyspace, 20);
3208 SHA_Final(&s, keyspace + 20);
3212 * Handle the SSH2 transport layer.
3214 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3216 static int i, j, len, nbits, pbits, warn;
3218 static Bignum p, g, e, f, K;
3219 static int kex_init_value, kex_reply_value;
3220 static const struct ssh_mac **maclist;
3222 static const struct ssh2_cipher *cscipher_tobe = NULL;
3223 static const struct ssh2_cipher *sccipher_tobe = NULL;
3224 static const struct ssh_mac *csmac_tobe = NULL;
3225 static const struct ssh_mac *scmac_tobe = NULL;
3226 static const struct ssh_compress *cscomp_tobe = NULL;
3227 static const struct ssh_compress *sccomp_tobe = NULL;
3228 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3229 static int hostkeylen, siglen;
3230 static void *hkey; /* actual host key */
3231 static unsigned char exchange_hash[20];
3232 static unsigned char keyspace[40];
3233 static int n_preferred_ciphers;
3234 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3235 static const struct ssh_compress *preferred_comp;
3236 static int cipherstr_started;
3237 static int first_kex;
3244 * Set up the preferred ciphers. (NULL => warn below here)
3246 n_preferred_ciphers = 0;
3247 for (i = 0; i < CIPHER_MAX; i++) {
3248 switch (cfg.ssh_cipherlist[i]) {
3249 case CIPHER_BLOWFISH:
3250 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3251 n_preferred_ciphers++;
3254 if (cfg.ssh2_des_cbc) {
3255 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3256 n_preferred_ciphers++;
3260 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3261 n_preferred_ciphers++;
3264 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3265 n_preferred_ciphers++;
3268 /* Flag for later. Don't bother if it's the last in
3270 if (i < CIPHER_MAX - 1) {
3271 preferred_ciphers[n_preferred_ciphers] = NULL;
3272 n_preferred_ciphers++;
3279 * Set up preferred compression.
3281 if (cfg.compression)
3282 preferred_comp = &ssh_zlib;
3284 preferred_comp = &ssh_comp_none;
3287 * Be prepared to work around the buggy MAC problem.
3289 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3290 maclist = buggymacs, nmacs = lenof(buggymacs);
3292 maclist = macs, nmacs = lenof(macs);
3296 * Construct and send our key exchange packet.
3298 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3299 for (i = 0; i < 16; i++)
3300 ssh2_pkt_addbyte((unsigned char) random_byte());
3301 /* List key exchange algorithms. */
3302 ssh2_pkt_addstring_start();
3303 for (i = 0; i < lenof(kex_algs); i++) {
3304 ssh2_pkt_addstring_str(kex_algs[i]->name);
3305 if (i < lenof(kex_algs) - 1)
3306 ssh2_pkt_addstring_str(",");
3308 /* List server host key algorithms. */
3309 ssh2_pkt_addstring_start();
3310 for (i = 0; i < lenof(hostkey_algs); i++) {
3311 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3312 if (i < lenof(hostkey_algs) - 1)
3313 ssh2_pkt_addstring_str(",");
3315 /* List client->server encryption algorithms. */
3316 ssh2_pkt_addstring_start();
3317 cipherstr_started = 0;
3318 for (i = 0; i < n_preferred_ciphers; i++) {
3319 const struct ssh2_ciphers *c = preferred_ciphers[i];
3320 if (!c) continue; /* warning flag */
3321 for (j = 0; j < c->nciphers; j++) {
3322 if (cipherstr_started)
3323 ssh2_pkt_addstring_str(",");
3324 ssh2_pkt_addstring_str(c->list[j]->name);
3325 cipherstr_started = 1;
3328 /* List server->client encryption algorithms. */
3329 ssh2_pkt_addstring_start();
3330 cipherstr_started = 0;
3331 for (i = 0; i < n_preferred_ciphers; i++) {
3332 const struct ssh2_ciphers *c = preferred_ciphers[i];
3333 if (!c) continue; /* warning flag */
3334 for (j = 0; j < c->nciphers; j++) {
3335 if (cipherstr_started)
3336 ssh2_pkt_addstring_str(",");
3337 ssh2_pkt_addstring_str(c->list[j]->name);
3338 cipherstr_started = 1;
3341 /* List client->server MAC algorithms. */
3342 ssh2_pkt_addstring_start();
3343 for (i = 0; i < nmacs; i++) {
3344 ssh2_pkt_addstring_str(maclist[i]->name);
3346 ssh2_pkt_addstring_str(",");
3348 /* List server->client MAC algorithms. */
3349 ssh2_pkt_addstring_start();
3350 for (i = 0; i < nmacs; i++) {
3351 ssh2_pkt_addstring_str(maclist[i]->name);
3353 ssh2_pkt_addstring_str(",");
3355 /* List client->server compression algorithms. */
3356 ssh2_pkt_addstring_start();
3357 for (i = 0; i < lenof(compressions) + 1; i++) {
3358 const struct ssh_compress *c =
3359 i == 0 ? preferred_comp : compressions[i - 1];
3360 ssh2_pkt_addstring_str(c->name);
3361 if (i < lenof(compressions))
3362 ssh2_pkt_addstring_str(",");
3364 /* List server->client compression algorithms. */
3365 ssh2_pkt_addstring_start();
3366 for (i = 0; i < lenof(compressions) + 1; i++) {
3367 const struct ssh_compress *c =
3368 i == 0 ? preferred_comp : compressions[i - 1];
3369 ssh2_pkt_addstring_str(c->name);
3370 if (i < lenof(compressions))
3371 ssh2_pkt_addstring_str(",");
3373 /* List client->server languages. Empty list. */
3374 ssh2_pkt_addstring_start();
3375 /* List server->client languages. Empty list. */
3376 ssh2_pkt_addstring_start();
3377 /* First KEX packet does _not_ follow, because we're not that brave. */
3378 ssh2_pkt_addbool(FALSE);
3380 ssh2_pkt_adduint32(0);
3382 exhash = exhashbase;
3383 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3389 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3392 * Now examine the other side's KEXINIT to see what we're up
3395 if (pktin.type != SSH2_MSG_KEXINIT) {
3396 bombout(("expected key exchange packet from server"));
3401 cscipher_tobe = NULL;
3402 sccipher_tobe = NULL;
3407 pktin.savedpos += 16; /* skip garbage cookie */
3408 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3409 for (i = 0; i < lenof(kex_algs); i++) {
3410 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3415 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3416 for (i = 0; i < lenof(hostkey_algs); i++) {
3417 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3418 hostkey = hostkey_algs[i];
3422 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3424 for (i = 0; i < n_preferred_ciphers; i++) {
3425 const struct ssh2_ciphers *c = preferred_ciphers[i];
3429 for (j = 0; j < c->nciphers; j++) {
3430 if (in_commasep_string(c->list[j]->name, str, len)) {
3431 cscipher_tobe = c->list[j];
3436 if (cscipher_tobe) {
3438 askcipher(cscipher_tobe->name, 1);
3442 if (!cscipher_tobe) {
3443 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3447 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3449 for (i = 0; i < n_preferred_ciphers; i++) {
3450 const struct ssh2_ciphers *c = preferred_ciphers[i];
3454 for (j = 0; j < c->nciphers; j++) {
3455 if (in_commasep_string(c->list[j]->name, str, len)) {
3456 sccipher_tobe = c->list[j];
3461 if (sccipher_tobe) {
3463 askcipher(sccipher_tobe->name, 2);
3467 if (!sccipher_tobe) {
3468 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3472 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3473 for (i = 0; i < nmacs; i++) {
3474 if (in_commasep_string(maclist[i]->name, str, len)) {
3475 csmac_tobe = maclist[i];
3479 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3480 for (i = 0; i < nmacs; i++) {
3481 if (in_commasep_string(maclist[i]->name, str, len)) {
3482 scmac_tobe = maclist[i];
3486 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3487 for (i = 0; i < lenof(compressions) + 1; i++) {
3488 const struct ssh_compress *c =
3489 i == 0 ? preferred_comp : compressions[i - 1];
3490 if (in_commasep_string(c->name, str, len)) {
3495 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3496 for (i = 0; i < lenof(compressions) + 1; i++) {
3497 const struct ssh_compress *c =
3498 i == 0 ? preferred_comp : compressions[i - 1];
3499 if (in_commasep_string(c->name, str, len)) {
3506 * Work out the number of bits of key we will need from the key
3507 * exchange. We start with the maximum key length of either
3513 csbits = cscipher_tobe->keylen;
3514 scbits = sccipher_tobe->keylen;
3515 nbits = (csbits > scbits ? csbits : scbits);
3517 /* The keys only have 160-bit entropy, since they're based on
3518 * a SHA-1 hash. So cap the key size at 160 bits. */
3523 * If we're doing Diffie-Hellman group exchange, start by
3524 * requesting a group.
3526 if (kex == &ssh_diffiehellman_gex) {
3527 logevent("Doing Diffie-Hellman group exchange");
3528 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
3530 * Work out how big a DH group we will need to allow that
3533 pbits = 512 << ((nbits - 1) / 64);
3534 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3535 ssh2_pkt_adduint32(pbits);
3539 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3540 bombout(("expected key exchange group packet from server"));
3543 p = ssh2_pkt_getmp();
3544 g = ssh2_pkt_getmp();
3545 dh_setup_group(p, g);
3546 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3547 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3549 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3551 kex_init_value = SSH2_MSG_KEXDH_INIT;
3552 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3555 logevent("Doing Diffie-Hellman key exchange");
3557 * Now generate and send e for Diffie-Hellman.
3559 e = dh_create_e(nbits * 2);
3560 ssh2_pkt_init(kex_init_value);
3565 if (pktin.type != kex_reply_value) {
3566 bombout(("expected key exchange reply packet from server"));
3569 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3570 f = ssh2_pkt_getmp();
3571 ssh2_pkt_getstring(&sigdata, &siglen);
3575 sha_string(&exhash, hostkeydata, hostkeylen);
3576 if (kex == &ssh_diffiehellman_gex) {
3577 sha_uint32(&exhash, pbits);
3578 sha_mpint(&exhash, p);
3579 sha_mpint(&exhash, g);
3581 sha_mpint(&exhash, e);
3582 sha_mpint(&exhash, f);
3583 sha_mpint(&exhash, K);
3584 SHA_Final(&exhash, exchange_hash);
3589 debug(("Exchange hash is:\n"));
3590 dmemdump(exchange_hash, 20);
3593 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3595 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3596 bombout(("Server's host key did not match the signature supplied"));
3601 * Authenticate remote host: verify host key. (We've already
3602 * checked the signature of the exchange hash.)
3604 keystr = hostkey->fmtkey(hkey);
3605 fingerprint = hostkey->fingerprint(hkey);
3606 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3607 keystr, fingerprint);
3608 if (first_kex) { /* don't bother logging this in rekeys */
3609 logevent("Host key fingerprint is:");
3610 logevent(fingerprint);
3614 hostkey->freekey(hkey);
3617 * Send SSH2_MSG_NEWKEYS.
3619 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3623 * Expect SSH2_MSG_NEWKEYS from server.
3626 if (pktin.type != SSH2_MSG_NEWKEYS) {
3627 bombout(("expected new-keys packet from server"));
3632 * Create and initialise session keys.
3634 cscipher = cscipher_tobe;
3635 sccipher = sccipher_tobe;
3638 cscomp = cscomp_tobe;
3639 sccomp = sccomp_tobe;
3640 cscomp->compress_init();
3641 sccomp->decompress_init();
3643 * Set IVs after keys. Here we use the exchange hash from the
3644 * _first_ key exchange.
3647 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3648 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3649 cscipher->setcskey(keyspace);
3650 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3651 sccipher->setsckey(keyspace);
3652 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3653 cscipher->setcsiv(keyspace);
3654 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3655 sccipher->setsciv(keyspace);
3656 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3657 csmac->setcskey(keyspace);
3658 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3659 scmac->setsckey(keyspace);
3662 * If this is the first key exchange phase, we must pass the
3663 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3664 * wants to see it but because it will need time to initialise
3665 * itself before it sees an actual packet. In subsequent key
3666 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3667 * it would only confuse the layer above.
3675 * Now we're encrypting. Begin returning 1 to the protocol main
3676 * function so that other things can run on top of the
3677 * transport. If we ever see a KEXINIT, we must go back to the
3680 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3683 logevent("Server initiated key re-exchange");
3684 goto begin_key_exchange;
3690 * Add data to an SSH2 channel output buffer.
3692 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3695 bufchain_add(&c->v.v2.outbuffer, buf, len);
3699 * Attempt to send data on an SSH2 channel.
3701 static int ssh2_try_send(struct ssh_channel *c)
3703 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3706 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3707 if ((unsigned)len > c->v.v2.remwindow)
3708 len = c->v.v2.remwindow;
3709 if ((unsigned)len > c->v.v2.remmaxpkt)
3710 len = c->v.v2.remmaxpkt;
3711 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3712 ssh2_pkt_adduint32(c->remoteid);
3713 ssh2_pkt_addstring_start();
3714 ssh2_pkt_addstring_data(data, len);
3716 bufchain_consume(&c->v.v2.outbuffer, len);
3717 c->v.v2.remwindow -= len;
3721 * After having sent as much data as we can, return the amount
3724 return bufchain_size(&c->v.v2.outbuffer);
3728 * Potentially enlarge the window on an SSH2 channel.
3730 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3732 if (newwin > c->v.v2.locwindow) {
3733 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3734 ssh2_pkt_adduint32(c->remoteid);
3735 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3737 c->v.v2.locwindow = newwin;
3742 * Handle the SSH2 userauth and connection layers.
3744 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3747 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3749 AUTH_KEYBOARD_INTERACTIVE
3753 AUTH_TYPE_PUBLICKEY,
3754 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3755 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3757 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3758 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3760 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3761 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
3762 static int kbd_inter_running;
3763 static int we_are_in;
3764 static int num_prompts, echo;
3765 static char username[100];
3766 static char pwprompt[200];
3767 static char password[100];
3768 static void *publickey_blob;
3769 static int publickey_bloblen;
3774 * Request userauth protocol, and await a response to it.
3776 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3777 ssh2_pkt_addstring("ssh-userauth");
3779 crWaitUntilV(ispkt);
3780 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3781 bombout(("Server refused user authentication protocol"));
3786 * We repeat this whole loop, including the username prompt,
3787 * until we manage a successful authentication. If the user
3788 * types the wrong _password_, they are sent back to the
3789 * beginning to try another username. (If they specify a
3790 * username in the config, they are never asked, even if they
3791 * do give a wrong password.)
3793 * I think this best serves the needs of
3795 * - the people who have no configuration, no keys, and just
3796 * want to try repeated (username,password) pairs until they
3797 * type both correctly
3799 * - people who have keys and configuration but occasionally
3800 * need to fall back to passwords
3802 * - people with a key held in Pageant, who might not have
3803 * logged in to a particular machine before; so they want to
3804 * type a username, and then _either_ their key will be
3805 * accepted, _or_ they will type a password. If they mistype
3806 * the username they will want to be able to get back and
3818 if (*username && !cfg.change_username) {
3820 * We got a username last time round this loop, and
3821 * with change_username turned off we don't try to get
3824 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3826 if (!ssh_get_line("login as: ",
3827 username, sizeof(username), FALSE)) {
3829 * get_line failed to get a username.
3832 logevent("No username provided. Abandoning session.");
3833 ssh_state = SSH_STATE_CLOSED;
3837 c_write_str("login as: ");
3840 crWaitUntilV(!ispkt);
3842 switch (c = *in++) {
3851 c_write_str("\b \b");
3858 c_write_str("\b \b");
3868 if (((c >= ' ' && c <= '~') ||
3869 ((unsigned char) c >= 160))
3870 && pos < sizeof(username)-1) {
3871 username[pos++] = c;
3878 c_write_str("\r\n");
3879 username[strcspn(username, "\n\r")] = '\0';
3882 strncpy(username, cfg.username, 99);
3883 username[99] = '\0';
3884 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3885 sprintf(stuff, "Using username \"%s\".\r\n", username);
3891 * Send an authentication request using method "none": (a)
3892 * just in case it succeeds, and (b) so that we know what
3893 * authentication methods we can usefully try next.
3895 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
3897 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3898 ssh2_pkt_addstring(username);
3899 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3900 ssh2_pkt_addstring("none"); /* method */
3902 type = AUTH_TYPE_NONE;
3906 tried_pubkey_config = FALSE;
3907 tried_agent = FALSE;
3908 tried_keyb_inter = FALSE;
3909 kbd_inter_running = FALSE;
3910 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
3912 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
3913 &publickey_bloblen);
3915 publickey_blob = NULL;
3919 * Wait for the result of the last authentication request.
3922 crWaitUntilV(ispkt);
3923 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3927 * Don't show the banner if we're operating in
3928 * non-verbose non-interactive mode. (It's probably
3929 * a script, which means nobody will read the
3930 * banner _anyway_, and moreover the printing of
3931 * the banner will screw up processing on the
3932 * output of (say) plink.)
3934 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3935 ssh2_pkt_getstring(&banner, &size);
3937 c_write_untrusted(banner, size);
3939 crWaitUntilV(ispkt);
3941 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3942 logevent("Access granted");
3947 if (kbd_inter_running &&
3948 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3950 * This is a further prompt in keyboard-interactive
3951 * authentication. Do nothing.
3953 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3954 bombout(("Strange packet received during authentication: type %d",
3962 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3963 * we can look at the string in it and know what we can
3964 * helpfully try next.
3966 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
3969 ssh2_pkt_getstring(&methods, &methlen);
3970 kbd_inter_running = FALSE;
3971 if (!ssh2_pkt_getbool()) {
3973 * We have received an unequivocal Access
3974 * Denied. This can translate to a variety of
3977 * - if we'd just tried "none" authentication,
3978 * it's not worth printing anything at all
3980 * - if we'd just tried a public key _offer_,
3981 * the message should be "Server refused our
3982 * key" (or no message at all if the key
3983 * came from Pageant)
3985 * - if we'd just tried anything else, the
3986 * message really should be "Access denied".
3988 * Additionally, if we'd just tried password
3989 * authentication, we should break out of this
3990 * whole loop so as to go back to the username
3993 if (type == AUTH_TYPE_NONE) {
3995 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3996 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3997 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3998 c_write_str("Server refused our key\r\n");
3999 logevent("Server refused public key");
4000 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4001 /* server declined keyboard-interactive; ignore */
4003 c_write_str("Access denied\r\n");
4004 logevent("Access denied");
4005 if (type == AUTH_TYPE_PASSWORD) {
4011 c_write_str("Further authentication required\r\n");
4012 logevent("Further authentication required");
4016 in_commasep_string("publickey", methods, methlen);
4018 in_commasep_string("password", methods, methlen);
4019 can_keyb_inter = cfg.try_ki_auth &&
4020 in_commasep_string("keyboard-interactive", methods, methlen);
4024 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4026 if (!method && can_pubkey && agent_exists() && !tried_agent) {
4028 * Attempt public-key authentication using Pageant.
4030 static unsigned char request[5], *response, *p;
4031 static int responselen;
4032 static int i, nkeys;
4033 static int authed = FALSE;
4036 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4040 logevent("Pageant is running. Requesting keys.");
4042 /* Request the keys held by the agent. */
4043 PUT_32BIT(request, 1);
4044 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4045 agent_query(request, 5, &r, &responselen);
4046 response = (unsigned char *) r;
4047 if (response && responselen >= 5 &&
4048 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4050 nkeys = GET_32BIT(p);
4054 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4057 for (i = 0; i < nkeys; i++) {
4058 static char *pkblob, *alg, *commentp;
4059 static int pklen, alglen, commentlen;
4060 static int siglen, retlen, len;
4061 static char *q, *agentreq, *ret;
4066 sprintf(buf, "Trying Pageant key #%d", i);
4069 pklen = GET_32BIT(p);
4071 if (publickey_blob &&
4072 pklen == publickey_bloblen &&
4073 !memcmp(p, publickey_blob, publickey_bloblen)) {
4074 logevent("This key matches configured key file");
4075 tried_pubkey_config = 1;
4079 alglen = GET_32BIT(pkblob);
4081 commentlen = GET_32BIT(p);
4085 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4086 ssh2_pkt_addstring(username);
4087 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4088 ssh2_pkt_addstring("publickey"); /* method */
4089 ssh2_pkt_addbool(FALSE); /* no signature included */
4090 ssh2_pkt_addstring_start();
4091 ssh2_pkt_addstring_data(alg, alglen);
4092 ssh2_pkt_addstring_start();
4093 ssh2_pkt_addstring_data(pkblob, pklen);
4096 crWaitUntilV(ispkt);
4097 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4098 logevent("Key refused");
4102 if (flags & FLAG_VERBOSE) {
4104 ("Authenticating with public key \"");
4105 c_write(commentp, commentlen);
4106 c_write_str("\" from agent\r\n");
4110 * Server is willing to accept the key.
4111 * Construct a SIGN_REQUEST.
4113 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4114 ssh2_pkt_addstring(username);
4115 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4116 ssh2_pkt_addstring("publickey"); /* method */
4117 ssh2_pkt_addbool(TRUE);
4118 ssh2_pkt_addstring_start();
4119 ssh2_pkt_addstring_data(alg, alglen);
4120 ssh2_pkt_addstring_start();
4121 ssh2_pkt_addstring_data(pkblob, pklen);
4123 siglen = pktout.length - 5 + 4 + 20;
4124 len = 1; /* message type */
4125 len += 4 + pklen; /* key blob */
4126 len += 4 + siglen; /* data to sign */
4127 len += 4; /* flags */
4128 agentreq = smalloc(4 + len);
4129 PUT_32BIT(agentreq, len);
4131 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4132 PUT_32BIT(q, pklen);
4134 memcpy(q, pkblob, pklen);
4136 PUT_32BIT(q, siglen);
4138 /* Now the data to be signed... */
4141 memcpy(q, ssh2_session_id, 20);
4143 memcpy(q, pktout.data + 5, pktout.length - 5);
4144 q += pktout.length - 5;
4145 /* And finally the (zero) flags word. */
4147 agent_query(agentreq, len + 4, &vret, &retlen);
4151 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4152 logevent("Sending Pageant's response");
4153 ssh2_pkt_addstring_start();
4154 ssh2_pkt_addstring_data(ret + 9,
4162 ("Pageant failed to answer challenge");
4172 if (!method && can_pubkey && *cfg.keyfile
4173 && !tried_pubkey_config) {
4174 unsigned char *pub_blob;
4175 char *algorithm, *comment;
4178 tried_pubkey_config = TRUE;
4180 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4183 * Try the public key supplied in the configuration.
4185 * First, offer the public blob to see if the server is
4186 * willing to accept it.
4188 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4191 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4192 ssh2_pkt_addstring(username);
4193 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4194 ssh2_pkt_addstring("publickey"); /* method */
4195 ssh2_pkt_addbool(FALSE); /* no signature included */
4196 ssh2_pkt_addstring(algorithm);
4197 ssh2_pkt_addstring_start();
4198 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4200 logevent("Offered public key"); /* FIXME */
4202 crWaitUntilV(ispkt);
4203 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4205 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4206 continue; /* key refused; give up on it */
4209 logevent("Offer of public key accepted");
4211 * Actually attempt a serious authentication using
4214 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4216 "Passphrase for key \"%.100s\": ",
4222 c_write_str("Authenticating with public key \"");
4223 c_write_str(comment);
4224 c_write_str("\"\r\n");
4225 method = AUTH_PUBLICKEY_FILE;
4229 if (!method && can_keyb_inter && !tried_keyb_inter) {
4230 method = AUTH_KEYBOARD_INTERACTIVE;
4231 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4232 tried_keyb_inter = TRUE;
4234 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4236 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4237 ssh2_pkt_addstring(username);
4238 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4239 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4240 ssh2_pkt_addstring(""); /* lang */
4241 ssh2_pkt_addstring("");
4244 crWaitUntilV(ispkt);
4245 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4246 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4248 logevent("Keyboard-interactive authentication refused");
4249 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4253 kbd_inter_running = TRUE;
4256 if (kbd_inter_running) {
4257 method = AUTH_KEYBOARD_INTERACTIVE;
4258 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4259 tried_keyb_inter = TRUE;
4261 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4263 /* We've got packet with that "interactive" info
4264 dump banners, and set its prompt as ours */
4266 char *name, *inst, *lang, *prompt;
4267 int name_len, inst_len, lang_len, prompt_len;
4268 ssh2_pkt_getstring(&name, &name_len);
4269 ssh2_pkt_getstring(&inst, &inst_len);
4270 ssh2_pkt_getstring(&lang, &lang_len);
4272 c_write_untrusted(name, name_len);
4274 c_write_untrusted(inst, inst_len);
4275 num_prompts = ssh2_pkt_getuint32();
4277 ssh2_pkt_getstring(&prompt, &prompt_len);
4278 strncpy(pwprompt, prompt, sizeof(pwprompt));
4279 pwprompt[prompt_len < sizeof(pwprompt) ?
4280 prompt_len : sizeof(pwprompt)-1] = '\0';
4283 echo = ssh2_pkt_getbool();
4287 if (!method && can_passwd) {
4288 method = AUTH_PASSWORD;
4289 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4290 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4297 if (!ssh_get_line(pwprompt, password,
4298 sizeof(password), TRUE)) {
4300 * get_line failed to get a password (for
4301 * example because one was supplied on the
4302 * command line which has already failed to
4305 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4306 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4308 ("No more passwords available to try");
4309 ssh2_pkt_addstring("en"); /* language tag */
4311 connection_fatal("Unable to authenticate");
4312 ssh_state = SSH_STATE_CLOSED;
4319 c_write_untrusted(pwprompt, strlen(pwprompt));
4324 crWaitUntilV(!ispkt);
4326 switch (c = *in++) {
4347 if (pos < sizeof(password)-1)
4348 password[pos++] = c;
4352 c_write_str("\r\n");
4356 if (method == AUTH_PUBLICKEY_FILE) {
4358 * We have our passphrase. Now try the actual authentication.
4360 struct ssh2_userkey *key;
4362 key = ssh2_load_userkey(cfg.keyfile, password);
4363 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4364 if (key == SSH2_WRONG_PASSPHRASE) {
4365 c_write_str("Wrong passphrase\r\n");
4366 tried_pubkey_config = FALSE;
4368 c_write_str("Unable to load private key\r\n");
4369 tried_pubkey_config = TRUE;
4371 /* Send a spurious AUTH_NONE to return to the top. */
4372 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4373 ssh2_pkt_addstring(username);
4374 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4375 ssh2_pkt_addstring("none"); /* method */
4377 type = AUTH_TYPE_NONE;
4379 unsigned char *blob, *sigdata;
4380 int blob_len, sigdata_len;
4383 * We have loaded the private key and the server
4384 * has announced that it's willing to accept it.
4385 * Hallelujah. Generate a signature and send it.
4387 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4388 ssh2_pkt_addstring(username);
4389 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4390 ssh2_pkt_addstring("publickey"); /* method */
4391 ssh2_pkt_addbool(TRUE);
4392 ssh2_pkt_addstring(key->alg->name);
4393 blob = key->alg->public_blob(key->data, &blob_len);
4394 ssh2_pkt_addstring_start();
4395 ssh2_pkt_addstring_data(blob, blob_len);
4399 * The data to be signed is:
4403 * followed by everything so far placed in the
4406 sigdata_len = pktout.length - 5 + 4 + 20;
4407 sigdata = smalloc(sigdata_len);
4408 PUT_32BIT(sigdata, 20);
4409 memcpy(sigdata + 4, ssh2_session_id, 20);
4410 memcpy(sigdata + 24, pktout.data + 5,
4413 key->alg->sign(key->data, sigdata, sigdata_len,
4415 ssh2_pkt_addstring_start();
4416 ssh2_pkt_addstring_data(blob, blob_len);
4421 type = AUTH_TYPE_PUBLICKEY;
4423 } else if (method == AUTH_PASSWORD) {
4425 * We send the password packet lumped tightly together with
4426 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4427 * string long enough to make the total length of the two
4428 * packets constant. This should ensure that a passive
4429 * listener doing traffic analyis can't work out the length
4432 * For this to work, we need an assumption about the
4433 * maximum length of the password packet. I think 256 is
4434 * pretty conservative. Anyone using a password longer than
4435 * that probably doesn't have much to worry about from
4436 * people who find out how long their password is!
4438 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4439 ssh2_pkt_addstring(username);
4440 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4441 ssh2_pkt_addstring("password");
4442 ssh2_pkt_addbool(FALSE);
4443 ssh2_pkt_addstring(password);
4446 * We'll include a string that's an exact multiple of the
4447 * cipher block size. If the cipher is NULL for some
4448 * reason, we don't do this trick at all because we gain
4454 stringlen = (256 - deferred_len);
4455 stringlen += cscipher->blksize - 1;
4456 stringlen -= (stringlen % cscipher->blksize);
4459 * Temporarily disable actual compression,
4460 * so we can guarantee to get this string
4461 * exactly the length we want it. The
4462 * compression-disabling routine should
4463 * return an integer indicating how many
4464 * bytes we should adjust our string length
4467 stringlen -= cscomp->disable_compression();
4469 ssh2_pkt_init(SSH2_MSG_IGNORE);
4470 ssh2_pkt_addstring_start();
4471 for (i = 0; i < stringlen; i++) {
4472 char c = (char) random_byte();
4473 ssh2_pkt_addstring_data(&c, 1);
4477 ssh_pkt_defersend();
4478 logevent("Sent password");
4479 type = AUTH_TYPE_PASSWORD;
4480 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4481 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4482 ssh2_pkt_adduint32(num_prompts);
4483 ssh2_pkt_addstring(password);
4484 memset(password, 0, sizeof(password));
4486 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4489 ("No supported authentication methods left to try!\r\n");
4491 ("No supported authentications offered. Disconnecting");
4492 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4493 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4495 ("No supported authentication methods available");
4496 ssh2_pkt_addstring("en"); /* language tag */
4498 ssh_state = SSH_STATE_CLOSED;
4502 } while (!we_are_in);
4505 * Now we're authenticated for the connection protocol. The
4506 * connection protocol will automatically have started at this
4507 * point; there's no need to send SERVICE_REQUEST.
4511 * So now create a channel with a session in it.
4513 ssh_channels = newtree234(ssh_channelcmp);
4514 mainchan = smalloc(sizeof(struct ssh_channel));
4515 mainchan->localid = alloc_channel_id();
4516 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4517 ssh2_pkt_addstring("session");
4518 ssh2_pkt_adduint32(mainchan->localid);
4519 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4520 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4521 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4523 crWaitUntilV(ispkt);
4524 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4525 bombout(("Server refused to open a session"));
4527 /* FIXME: error data comes back in FAILURE packet */
4529 if (ssh2_pkt_getuint32() != mainchan->localid) {
4530 bombout(("Server's channel confirmation cited wrong channel"));
4533 mainchan->remoteid = ssh2_pkt_getuint32();
4534 mainchan->type = CHAN_MAINSESSION;
4535 mainchan->closes = 0;
4536 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4537 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4538 bufchain_init(&mainchan->v.v2.outbuffer);
4539 add234(ssh_channels, mainchan);
4540 logevent("Opened channel for session");
4543 * Potentially enable X11 forwarding.
4545 if (cfg.x11_forward) {
4546 char proto[20], data[64];
4547 logevent("Requesting X11 forwarding");
4548 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4549 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4550 ssh2_pkt_adduint32(mainchan->remoteid);
4551 ssh2_pkt_addstring("x11-req");
4552 ssh2_pkt_addbool(1); /* want reply */
4553 ssh2_pkt_addbool(0); /* many connections */
4554 ssh2_pkt_addstring(proto);
4555 ssh2_pkt_addstring(data);
4556 ssh2_pkt_adduint32(0); /* screen number */
4560 crWaitUntilV(ispkt);
4561 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4562 unsigned i = ssh2_pkt_getuint32();
4563 struct ssh_channel *c;
4564 c = find234(ssh_channels, &i, ssh_channelfind);
4566 continue; /* nonexistent channel */
4567 c->v.v2.remwindow += ssh2_pkt_getuint32();
4569 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4571 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4572 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4573 bombout(("Unexpected response to X11 forwarding request:"
4574 " packet type %d", pktin.type));
4577 logevent("X11 forwarding refused");
4579 logevent("X11 forwarding enabled");
4580 ssh_X11_fwd_enabled = TRUE;
4585 * Enable port forwardings.
4588 static char *e; /* preserve across crReturn */
4592 char sports[256], dports[256], host[256];
4595 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4596 /* Add port forwardings. */
4601 while (*e && *e != '\t')
4607 while (*e && *e != ':')
4617 dport = atoi(dports);
4618 sport = atoi(sports);
4619 if (sport && dport) {
4621 pfd_addforward(host, dport, sport);
4622 sprintf(buf, "Local port %d forwarding to %s:%d",
4623 sport, host, dport);
4626 struct ssh_rportfwd *pf;
4627 pf = smalloc(sizeof(*pf));
4628 strcpy(pf->dhost, host);
4631 if (add234(ssh_rportfwds, pf) != pf) {
4633 "Duplicate remote port forwarding to %s:%d",
4638 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4639 sport, host, dport);
4641 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4642 ssh2_pkt_addstring("tcpip-forward");
4643 ssh2_pkt_addbool(1);/* want reply */
4644 if (cfg.rport_acceptall)
4645 ssh2_pkt_addstring("0.0.0.0");
4647 ssh2_pkt_addstring("127.0.0.1");
4648 ssh2_pkt_adduint32(sport);
4652 crWaitUntilV(ispkt);
4653 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4654 unsigned i = ssh2_pkt_getuint32();
4655 struct ssh_channel *c;
4656 c = find234(ssh_channels, &i, ssh_channelfind);
4658 continue;/* nonexistent channel */
4659 c->v.v2.remwindow += ssh2_pkt_getuint32();
4661 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4663 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4664 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4665 bombout(("Unexpected response to port "
4666 "forwarding request: packet type %d",
4670 logevent("Server refused this port forwarding");
4672 logevent("Remote port forwarding enabled");
4681 * Potentially enable agent forwarding.
4683 if (cfg.agentfwd && agent_exists()) {
4684 logevent("Requesting OpenSSH-style agent forwarding");
4685 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4686 ssh2_pkt_adduint32(mainchan->remoteid);
4687 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4688 ssh2_pkt_addbool(1); /* want reply */
4692 crWaitUntilV(ispkt);
4693 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4694 unsigned i = ssh2_pkt_getuint32();
4695 struct ssh_channel *c;
4696 c = find234(ssh_channels, &i, ssh_channelfind);
4698 continue; /* nonexistent channel */
4699 c->v.v2.remwindow += ssh2_pkt_getuint32();
4701 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4703 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4704 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4705 bombout(("Unexpected response to agent forwarding request:"
4706 " packet type %d", pktin.type));
4709 logevent("Agent forwarding refused");
4711 logevent("Agent forwarding enabled");
4712 ssh_agentfwd_enabled = TRUE;
4717 * Now allocate a pty for the session.
4720 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4721 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4722 ssh2_pkt_addstring("pty-req");
4723 ssh2_pkt_addbool(1); /* want reply */
4724 ssh2_pkt_addstring(cfg.termtype);
4725 ssh2_pkt_adduint32(cols);
4726 ssh2_pkt_adduint32(rows);
4727 ssh2_pkt_adduint32(0); /* pixel width */
4728 ssh2_pkt_adduint32(0); /* pixel height */
4729 ssh2_pkt_addstring_start();
4730 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4732 ssh_state = SSH_STATE_INTERMED;
4735 crWaitUntilV(ispkt);
4736 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4737 unsigned i = ssh2_pkt_getuint32();
4738 struct ssh_channel *c;
4739 c = find234(ssh_channels, &i, ssh_channelfind);
4741 continue; /* nonexistent channel */
4742 c->v.v2.remwindow += ssh2_pkt_getuint32();
4744 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4746 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4747 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4748 bombout(("Unexpected response to pty request:"
4749 " packet type %d", pktin.type));
4752 c_write_str("Server refused to allocate pty\r\n");
4753 ssh_editing = ssh_echoing = 1;
4755 logevent("Allocated pty");
4758 ssh_editing = ssh_echoing = 1;
4762 * Start a shell or a remote command. We may have to attempt
4763 * this twice if the config data has provided a second choice
4770 if (ssh_fallback_cmd) {
4771 subsys = cfg.ssh_subsys2;
4772 cmd = cfg.remote_cmd_ptr2;
4774 subsys = cfg.ssh_subsys;
4775 cmd = cfg.remote_cmd_ptr;
4778 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4779 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4781 ssh2_pkt_addstring("subsystem");
4782 ssh2_pkt_addbool(1); /* want reply */
4783 ssh2_pkt_addstring(cmd);
4785 ssh2_pkt_addstring("exec");
4786 ssh2_pkt_addbool(1); /* want reply */
4787 ssh2_pkt_addstring(cmd);
4789 ssh2_pkt_addstring("shell");
4790 ssh2_pkt_addbool(1); /* want reply */
4794 crWaitUntilV(ispkt);
4795 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4796 unsigned i = ssh2_pkt_getuint32();
4797 struct ssh_channel *c;
4798 c = find234(ssh_channels, &i, ssh_channelfind);
4800 continue; /* nonexistent channel */
4801 c->v.v2.remwindow += ssh2_pkt_getuint32();
4803 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4804 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4805 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4806 bombout(("Unexpected response to shell/command request:"
4807 " packet type %d", pktin.type));
4811 * We failed to start the command. If this is the
4812 * fallback command, we really are finished; if it's
4813 * not, and if the fallback command exists, try falling
4814 * back to it before complaining.
4816 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
4817 logevent("Primary command failed; attempting fallback");
4818 ssh_fallback_cmd = TRUE;
4821 bombout(("Server refused to start a shell/command"));
4824 logevent("Started a shell/command");
4829 ssh_state = SSH_STATE_SESSION;
4833 ssh_special(TS_EOF);
4838 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
4841 static int try_send;
4845 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
4846 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4849 unsigned i = ssh2_pkt_getuint32();
4850 struct ssh_channel *c;
4851 c = find234(ssh_channels, &i, ssh_channelfind);
4853 continue; /* nonexistent channel */
4854 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4855 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4856 continue; /* extended but not stderr */
4857 ssh2_pkt_getstring(&data, &length);
4860 c->v.v2.locwindow -= length;
4862 case CHAN_MAINSESSION:
4864 from_backend(pktin.type ==
4865 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4869 bufsize = x11_send(c->u.x11.s, data, length);
4872 bufsize = pfd_send(c->u.pfd.s, data, length);
4875 while (length > 0) {
4876 if (c->u.a.lensofar < 4) {
4877 int l = min(4 - c->u.a.lensofar, length);
4878 memcpy(c->u.a.msglen + c->u.a.lensofar,
4882 c->u.a.lensofar += l;
4884 if (c->u.a.lensofar == 4) {
4886 4 + GET_32BIT(c->u.a.msglen);
4887 c->u.a.message = smalloc(c->u.a.totallen);
4888 memcpy(c->u.a.message, c->u.a.msglen, 4);
4890 if (c->u.a.lensofar >= 4 && length > 0) {
4892 min(c->u.a.totallen - c->u.a.lensofar,
4894 memcpy(c->u.a.message + c->u.a.lensofar,
4898 c->u.a.lensofar += l;
4900 if (c->u.a.lensofar == c->u.a.totallen) {
4901 void *reply, *sentreply;
4903 agent_query(c->u.a.message,
4904 c->u.a.totallen, &reply,
4909 /* Fake SSH_AGENT_FAILURE. */
4910 sentreply = "\0\0\0\1\5";
4913 ssh2_add_channel_data(c, sentreply,
4918 sfree(c->u.a.message);
4919 c->u.a.lensofar = 0;
4926 * If we are not buffering too much data,
4927 * enlarge the window again at the remote side.
4929 if (bufsize < OUR_V2_WINSIZE)
4930 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
4932 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4933 ssh_state = SSH_STATE_CLOSED;
4934 logevent("Received disconnect message");
4936 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4937 unsigned i = ssh2_pkt_getuint32();
4938 struct ssh_channel *c;
4940 c = find234(ssh_channels, &i, ssh_channelfind);
4942 continue; /* nonexistent channel */
4944 if (c->type == CHAN_X11) {
4946 * Remote EOF on an X11 channel means we should
4947 * wrap up and close the channel ourselves.
4949 x11_close(c->u.x11.s);
4951 } else if (c->type == CHAN_AGENT) {
4953 } else if (c->type == CHAN_SOCKDATA) {
4954 pfd_close(c->u.pfd.s);
4957 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4958 unsigned i = ssh2_pkt_getuint32();
4959 struct ssh_channel *c;
4961 c = find234(ssh_channels, &i, ssh_channelfind);
4963 continue; /* nonexistent channel */
4964 /* Do pre-close processing on the channel. */
4966 case CHAN_MAINSESSION:
4967 break; /* nothing to see here, move along */
4969 if (c->u.x11.s != NULL)
4970 x11_close(c->u.x11.s);
4977 if (c->u.pfd.s != NULL)
4978 pfd_close(c->u.pfd.s);
4982 if (c->closes == 0) {
4983 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4984 ssh2_pkt_adduint32(c->remoteid);
4987 del234(ssh_channels, c);
4988 bufchain_clear(&c->v.v2.outbuffer);
4992 * See if that was the last channel left open.
4994 if (count234(ssh_channels) == 0) {
4997 * We used to send SSH_MSG_DISCONNECT here,
4998 * because I'd believed that _every_ conforming
4999 * SSH2 connection had to end with a disconnect
5000 * being sent by at least one side; apparently
5001 * I was wrong and it's perfectly OK to
5002 * unceremoniously slam the connection shut
5003 * when you're done, and indeed OpenSSH feels
5004 * this is more polite than sending a
5005 * DISCONNECT. So now we don't.
5007 logevent("All channels closed. Disconnecting");
5008 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5009 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5010 ssh2_pkt_addstring("All open channels closed");
5011 ssh2_pkt_addstring("en"); /* language tag */
5014 ssh_state = SSH_STATE_CLOSED;
5017 continue; /* remote sends close; ignore (FIXME) */
5018 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5019 unsigned i = ssh2_pkt_getuint32();
5020 struct ssh_channel *c;
5021 c = find234(ssh_channels, &i, ssh_channelfind);
5023 continue; /* nonexistent channel */
5024 c->v.v2.remwindow += ssh2_pkt_getuint32();
5026 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5027 unsigned i = ssh2_pkt_getuint32();
5028 struct ssh_channel *c;
5029 c = find234(ssh_channels, &i, ssh_channelfind);
5031 continue; /* nonexistent channel */
5032 if (c->type != CHAN_SOCKDATA_DORMANT)
5033 continue; /* dunno why they're confirming this */
5034 c->remoteid = ssh2_pkt_getuint32();
5035 c->type = CHAN_SOCKDATA;
5036 c->v.v2.remwindow = ssh2_pkt_getuint32();
5037 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5038 bufchain_init(&c->v.v2.outbuffer);
5040 pfd_confirm(c->u.pfd.s);
5043 * We have a pending close on this channel,
5044 * which we decided on before the server acked
5045 * the channel open. So now we know the
5046 * remoteid, we can close it again.
5048 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5049 ssh2_pkt_adduint32(c->remoteid);
5052 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5053 unsigned i = ssh2_pkt_getuint32();
5054 struct ssh_channel *c;
5055 c = find234(ssh_channels, &i, ssh_channelfind);
5057 continue; /* nonexistent channel */
5058 if (c->type != CHAN_SOCKDATA_DORMANT)
5059 continue; /* dunno why they're failing this */
5061 logevent("Forwarded connection refused by server");
5063 pfd_close(c->u.pfd.s);
5065 del234(ssh_channels, c);
5067 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5070 int typelen, want_reply;
5071 struct ssh_channel *c;
5073 localid = ssh2_pkt_getuint32();
5074 ssh2_pkt_getstring(&type, &typelen);
5075 want_reply = ssh2_pkt_getbool();
5078 * First, check that the channel exists. Otherwise,
5079 * we can instantly disconnect with a rude message.
5081 c = find234(ssh_channels, &localid, ssh_channelfind);
5084 sprintf(buf, "Received channel request for nonexistent"
5085 " channel %d", localid);
5087 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5088 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5089 ssh2_pkt_addstring(buf);
5090 ssh2_pkt_addstring("en"); /* language tag */
5092 connection_fatal(buf);
5093 ssh_state = SSH_STATE_CLOSED;
5098 * Having got the channel number, we now look at
5099 * the request type string to see if it's something
5102 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5104 /* We recognise "exit-status" on the primary channel. */
5106 ssh_exitcode = ssh2_pkt_getuint32();
5107 sprintf(buf, "Server sent command exit status %d",
5111 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5112 ssh2_pkt_adduint32(c->remoteid);
5117 * This is a channel request we don't know
5118 * about, so we now either ignore the request
5119 * or respond with CHANNEL_FAILURE, depending
5123 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5124 ssh2_pkt_adduint32(c->remoteid);
5128 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5132 struct ssh_channel *c;
5133 unsigned remid, winsize, pktsize;
5134 ssh2_pkt_getstring(&type, &typelen);
5135 c = smalloc(sizeof(struct ssh_channel));
5137 remid = ssh2_pkt_getuint32();
5138 winsize = ssh2_pkt_getuint32();
5139 pktsize = ssh2_pkt_getuint32();
5141 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5142 if (!ssh_X11_fwd_enabled)
5143 error = "X11 forwarding is not enabled";
5144 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5146 error = "Unable to open an X11 connection";
5150 } else if (typelen == 15 &&
5151 !memcmp(type, "forwarded-tcpip", 15)) {
5152 struct ssh_rportfwd pf, *realpf;
5155 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5156 pf.sport = ssh2_pkt_getuint32();
5157 realpf = find234(ssh_rportfwds, &pf, NULL);
5158 if (realpf == NULL) {
5159 error = "Remote port is not recognised";
5161 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5164 sprintf(buf, "Received remote port open request for %s:%d",
5165 realpf->dhost, realpf->dport);
5168 sprintf(buf, "Port open failed: %s", e);
5170 error = "Port open failed";
5172 logevent("Forwarded port opened successfully");
5173 c->type = CHAN_SOCKDATA;
5176 } else if (typelen == 22 &&
5177 !memcmp(type, "auth-agent@openssh.com", 3)) {
5178 if (!ssh_agentfwd_enabled)
5179 error = "Agent forwarding is not enabled";
5181 c->type = CHAN_AGENT; /* identify channel type */
5182 c->u.a.lensofar = 0;
5185 error = "Unsupported channel type requested";
5188 c->remoteid = remid;
5190 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5191 ssh2_pkt_adduint32(c->remoteid);
5192 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5193 ssh2_pkt_addstring(error);
5194 ssh2_pkt_addstring("en"); /* language tag */
5198 c->localid = alloc_channel_id();
5200 c->v.v2.locwindow = OUR_V2_WINSIZE;
5201 c->v.v2.remwindow = winsize;
5202 c->v.v2.remmaxpkt = pktsize;
5203 bufchain_init(&c->v.v2.outbuffer);
5204 add234(ssh_channels, c);
5205 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5206 ssh2_pkt_adduint32(c->remoteid);
5207 ssh2_pkt_adduint32(c->localid);
5208 ssh2_pkt_adduint32(c->v.v2.locwindow);
5209 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5213 bombout(("Strange packet received: type %d", pktin.type));
5218 * We have spare data. Add it to the channel buffer.
5220 ssh2_add_channel_data(mainchan, in, inlen);
5225 struct ssh_channel *c;
5227 * Try to send data on all channels if we can.
5229 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5230 int bufsize = ssh2_try_send(c);
5233 case CHAN_MAINSESSION:
5234 /* stdin need not receive an unthrottle
5235 * notification since it will be polled */
5238 x11_unthrottle(c->u.x11.s);
5241 /* agent sockets are request/response and need no
5242 * buffer management */
5245 pfd_unthrottle(c->u.pfd.s);
5257 * Handle the top-level SSH2 protocol.
5259 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5261 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5263 do_ssh2_authconn(in, inlen, ispkt);
5267 * Called to set up the connection.
5269 * Returns an error message, or NULL on success.
5271 static char *ssh_init(char *host, int port, char **realhost, int nodelay)
5276 if (crypto_startup() == 0)
5277 return "Microsoft high encryption pack not installed!";
5283 ssh1_throttle_count = 0;
5284 ssh_overall_bufsize = 0;
5285 ssh_fallback_cmd = 0;
5287 p = connect_to_host(host, port, realhost, nodelay);
5295 * Called to send data down the Telnet connection.
5297 static int ssh_send(char *buf, int len)
5299 if (s == NULL || ssh_protocol == NULL)
5302 ssh_protocol(buf, len, 0);
5304 return ssh_sendbuffer();
5308 * Called to query the current amount of buffered stdin data.
5310 static int ssh_sendbuffer(void)
5314 if (s == NULL || ssh_protocol == NULL)
5318 * If the SSH socket itself has backed up, add the total backup
5319 * size on that to any individual buffer on the stdin channel.
5322 if (ssh_throttled_all)
5323 override_value = ssh_overall_bufsize;
5325 if (ssh_version == 1) {
5326 return override_value;
5327 } else if (ssh_version == 2) {
5328 if (!mainchan || mainchan->closes > 0)
5329 return override_value;
5331 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5338 * Called to set the size of the window from SSH's POV.
5340 static void ssh_size(void)
5342 switch (ssh_state) {
5343 case SSH_STATE_BEFORE_SIZE:
5344 case SSH_STATE_PREPACKET:
5345 case SSH_STATE_CLOSED:
5346 break; /* do nothing */
5347 case SSH_STATE_INTERMED:
5348 size_needed = TRUE; /* buffer for later */
5350 case SSH_STATE_SESSION:
5352 if (ssh_version == 1) {
5353 send_packet(SSH1_CMSG_WINDOW_SIZE,
5354 PKT_INT, rows, PKT_INT, cols,
5355 PKT_INT, 0, PKT_INT, 0, PKT_END);
5357 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5358 ssh2_pkt_adduint32(mainchan->remoteid);
5359 ssh2_pkt_addstring("window-change");
5360 ssh2_pkt_addbool(0);
5361 ssh2_pkt_adduint32(cols);
5362 ssh2_pkt_adduint32(rows);
5363 ssh2_pkt_adduint32(0);
5364 ssh2_pkt_adduint32(0);
5373 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5374 * can send an EOF and collect resulting output (e.g. `plink
5377 static void ssh_special(Telnet_Special code)
5379 if (code == TS_EOF) {
5380 if (ssh_state != SSH_STATE_SESSION) {
5382 * Buffer the EOF in case we are pre-SESSION, so we can
5383 * send it as soon as we reach SESSION.
5389 if (ssh_version == 1) {
5390 send_packet(SSH1_CMSG_EOF, PKT_END);
5392 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5393 ssh2_pkt_adduint32(mainchan->remoteid);
5396 logevent("Sent EOF message");
5397 } else if (code == TS_PING) {
5398 if (ssh_state == SSH_STATE_CLOSED
5399 || ssh_state == SSH_STATE_PREPACKET) return;
5400 if (ssh_version == 1) {
5401 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5403 ssh2_pkt_init(SSH2_MSG_IGNORE);
5404 ssh2_pkt_addstring_start();
5412 void *new_sock_channel(Socket s)
5414 struct ssh_channel *c;
5415 c = smalloc(sizeof(struct ssh_channel));
5418 c->remoteid = -1; /* to be set when open confirmed */
5419 c->localid = alloc_channel_id();
5421 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5423 add234(ssh_channels, c);
5429 * This is called when stdout/stderr (the entity to which
5430 * from_backend sends data) manages to clear some backlog.
5432 void ssh_unthrottle(int bufsize)
5434 if (ssh_version == 1) {
5435 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5436 ssh1_stdout_throttling = 0;
5440 if (mainchan && mainchan->closes == 0)
5441 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5445 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5447 struct ssh_channel *c = (struct ssh_channel *)channel;
5450 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5453 if (ssh_version == 1) {
5454 send_packet(SSH1_MSG_PORT_OPEN,
5455 PKT_INT, c->localid,
5458 //PKT_STR, <org:orgport>,
5461 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5462 ssh2_pkt_addstring("direct-tcpip");
5463 ssh2_pkt_adduint32(c->localid);
5464 c->v.v2.locwindow = OUR_V2_WINSIZE;
5465 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5466 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5467 ssh2_pkt_addstring(hostname);
5468 ssh2_pkt_adduint32(port);
5470 * We make up values for the originator data; partly it's
5471 * too much hassle to keep track, and partly I'm not
5472 * convinced the server should be told details like that
5473 * about my local network configuration.
5475 ssh2_pkt_addstring("client-side-connection");
5476 ssh2_pkt_adduint32(0);
5482 static Socket ssh_socket(void)
5487 static int ssh_sendok(void)
5492 static int ssh_ldisc(int option)
5494 if (option == LD_ECHO)
5496 if (option == LD_EDIT)
5501 static int ssh_return_exitcode(void)
5503 return ssh_exitcode;
5506 Backend ssh_backend = {
5513 ssh_return_exitcode,