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 */
503 static tree234 *ssh_rportfwds;
507 SSH_STATE_BEFORE_SIZE,
511 } ssh_state = SSH_STATE_PREPACKET;
513 static int size_needed = FALSE, eof_needed = FALSE;
515 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
516 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
517 static unsigned char *deferred_send_data = NULL;
518 static int deferred_len = 0, deferred_size = 0;
521 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
522 * that fails. This variable is the means by which scp.c can reach
523 * into the SSH code and find out which one it got.
525 int ssh_fallback_cmd = 0;
527 static int ssh_version;
528 static int ssh1_throttle_count;
529 static int ssh_overall_bufsize;
530 static int ssh_throttled_all;
531 static int ssh1_stdout_throttling;
532 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
533 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
534 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
535 static void ssh_size(void);
536 static void ssh_special(Telnet_Special);
537 static int ssh2_try_send(struct ssh_channel *c);
538 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
540 static void ssh_throttle_all(int enable, int bufsize);
541 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
542 static int (*s_rdpkt) (unsigned char **data, int *datalen);
543 static int ssh_sendbuffer(void);
545 static struct rdpkt1_state_tag {
546 long len, pad, biglen, to_read;
547 unsigned long realcrc, gotcrc;
553 static struct rdpkt2_state_tag {
554 long len, pad, payload, packetlen, maclen;
557 unsigned long incoming_sequence;
560 static int ssh_channelcmp(void *av, void *bv)
562 struct ssh_channel *a = (struct ssh_channel *) av;
563 struct ssh_channel *b = (struct ssh_channel *) bv;
564 if (a->localid < b->localid)
566 if (a->localid > b->localid)
570 static int ssh_channelfind(void *av, void *bv)
572 unsigned *a = (unsigned *) av;
573 struct ssh_channel *b = (struct ssh_channel *) bv;
581 static int ssh_rportcmp_ssh1(void *av, void *bv)
583 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
584 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
586 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
587 return i < 0 ? -1 : +1;
588 if (a->dport > b->dport)
590 if (a->dport < b->dport)
595 static int ssh_rportcmp_ssh2(void *av, void *bv)
597 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
598 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
600 if (a->sport > b->sport)
602 if (a->sport < b->sport)
607 static int alloc_channel_id(void)
609 const unsigned CHANNEL_NUMBER_OFFSET = 256;
610 unsigned low, high, mid;
612 struct ssh_channel *c;
615 * First-fit allocation of channel numbers: always pick the
616 * lowest unused one. To do this, binary-search using the
617 * counted B-tree to find the largest channel ID which is in a
618 * contiguous sequence from the beginning. (Precisely
619 * everything in that sequence must have ID equal to its tree
620 * index plus CHANNEL_NUMBER_OFFSET.)
622 tsize = count234(ssh_channels);
626 while (high - low > 1) {
627 mid = (high + low) / 2;
628 c = index234(ssh_channels, mid);
629 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
630 low = mid; /* this one is fine */
632 high = mid; /* this one is past it */
635 * Now low points to either -1, or the tree index of the
636 * largest ID in the initial sequence.
639 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
640 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
642 return low + 1 + CHANNEL_NUMBER_OFFSET;
645 static void c_write(char *buf, int len)
647 if ((flags & FLAG_STDERR)) {
649 for (i = 0; i < len; i++)
651 fputc(buf[i], stderr);
654 from_backend(1, buf, len);
657 static void c_write_untrusted(char *buf, int len)
660 for (i = 0; i < len; i++) {
663 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
668 static void c_write_str(char *buf)
670 c_write(buf, strlen(buf));
674 * Collect incoming data in the incoming packet buffer.
675 * Decipher and verify the packet when it is completely read.
676 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
677 * Update the *data and *datalen variables.
678 * Return the additional nr of bytes needed, or 0 when
679 * a complete packet is available.
681 static int ssh1_rdpkt(unsigned char **data, int *datalen)
683 struct rdpkt1_state_tag *st = &rdpkt1_state;
692 for (st->i = st->len = 0; st->i < 4; st->i++) {
693 while ((*datalen) == 0)
695 st->len = (st->len << 8) + **data;
696 (*data)++, (*datalen)--;
699 st->pad = 8 - (st->len % 8);
700 st->biglen = st->len + st->pad;
701 pktin.length = st->len - 5;
703 if (pktin.maxlen < st->biglen) {
704 pktin.maxlen = st->biglen;
705 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
706 srealloc(pktin.data, st->biglen + APIEXTRA));
708 fatalbox("Out of memory");
711 st->to_read = st->biglen;
713 while (st->to_read > 0) {
714 st->chunk = st->to_read;
715 while ((*datalen) == 0)
716 crReturn(st->to_read);
717 if (st->chunk > (*datalen))
718 st->chunk = (*datalen);
719 memcpy(st->p, *data, st->chunk);
721 *datalen -= st->chunk;
723 st->to_read -= st->chunk;
727 cipher->decrypt(pktin.data, st->biglen);
729 st->realcrc = crc32(pktin.data, st->biglen - 4);
730 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
731 if (st->gotcrc != st->realcrc) {
732 bombout(("Incorrect CRC received on packet"));
736 pktin.body = pktin.data + st->pad + 1;
738 if (ssh1_compressing) {
739 unsigned char *decompblk;
741 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
742 &decompblk, &decomplen);
744 if (pktin.maxlen < st->pad + decomplen) {
745 pktin.maxlen = st->pad + decomplen;
746 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
747 pktin.body = pktin.data + st->pad + 1;
749 fatalbox("Out of memory");
752 memcpy(pktin.body - 1, decompblk, decomplen);
754 pktin.length = decomplen - 1;
757 pktin.type = pktin.body[-1];
759 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
760 pktin.body, pktin.length);
762 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
763 pktin.type == SSH1_SMSG_STDERR_DATA ||
764 pktin.type == SSH1_MSG_DEBUG ||
765 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
766 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
767 long strlen = GET_32BIT(pktin.body);
768 if (strlen + 4 != pktin.length) {
769 bombout(("Received data packet with bogus string length"));
774 if (pktin.type == SSH1_MSG_DEBUG) {
775 /* log debug message */
777 int strlen = GET_32BIT(pktin.body);
778 strcpy(buf, "Remote: ");
781 memcpy(buf + 8, pktin.body + 4, strlen);
782 buf[8 + strlen] = '\0';
785 } else if (pktin.type == SSH1_MSG_IGNORE) {
790 if (pktin.type == SSH1_MSG_DISCONNECT) {
791 /* log reason code in disconnect message */
793 unsigned msglen = GET_32BIT(pktin.body);
795 strcpy(buf, "Remote sent disconnect: ");
796 nowlen = strlen(buf);
797 if (msglen > sizeof(buf) - nowlen - 1)
798 msglen = sizeof(buf) - nowlen - 1;
799 memcpy(buf + nowlen, pktin.body + 4, msglen);
800 buf[nowlen + msglen] = '\0';
802 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
809 static int ssh2_rdpkt(unsigned char **data, int *datalen)
811 struct rdpkt2_state_tag *st = &rdpkt2_state;
819 st->cipherblk = sccipher->blksize;
822 if (st->cipherblk < 8)
825 if (pktin.maxlen < st->cipherblk) {
826 pktin.maxlen = st->cipherblk;
829 NULL ? smalloc(st->cipherblk +
830 APIEXTRA) : srealloc(pktin.data,
834 fatalbox("Out of memory");
838 * Acquire and decrypt the first block of the packet. This will
839 * contain the length and padding details.
841 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
842 while ((*datalen) == 0)
843 crReturn(st->cipherblk - st->i);
844 pktin.data[st->i] = *(*data)++;
849 sccipher->decrypt(pktin.data, st->cipherblk);
852 * Now get the length and padding figures.
854 st->len = GET_32BIT(pktin.data);
855 st->pad = pktin.data[4];
858 * This enables us to deduce the payload length.
860 st->payload = st->len - st->pad - 1;
862 pktin.length = st->payload + 5;
865 * So now we can work out the total packet length.
867 st->packetlen = st->len + 4;
868 st->maclen = scmac ? scmac->len : 0;
871 * Adjust memory allocation if packet is too big.
873 if (pktin.maxlen < st->packetlen + st->maclen) {
874 pktin.maxlen = st->packetlen + st->maclen;
877 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
882 fatalbox("Out of memory");
886 * Read and decrypt the remainder of the packet.
888 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
890 while ((*datalen) == 0)
891 crReturn(st->packetlen + st->maclen - st->i);
892 pktin.data[st->i] = *(*data)++;
895 /* Decrypt everything _except_ the MAC. */
897 sccipher->decrypt(pktin.data + st->cipherblk,
898 st->packetlen - st->cipherblk);
904 && !scmac->verify(pktin.data, st->len + 4,
905 st->incoming_sequence)) {
906 bombout(("Incorrect MAC received on packet"));
909 st->incoming_sequence++; /* whether or not we MACed */
912 * Decompress packet payload.
915 unsigned char *newpayload;
917 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
918 &newpayload, &newlen)) {
919 if (pktin.maxlen < newlen + 5) {
920 pktin.maxlen = newlen + 5;
923 NULL ? smalloc(pktin.maxlen +
924 APIEXTRA) : srealloc(pktin.data,
928 fatalbox("Out of memory");
930 pktin.length = 5 + newlen;
931 memcpy(pktin.data + 5, newpayload, newlen);
937 pktin.type = pktin.data[5];
939 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
940 pktin.data+6, pktin.length-6);
942 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
943 goto next_packet; /* FIXME: print DEBUG message */
945 if (pktin.type == SSH2_MSG_DISCONNECT) {
946 /* log reason code in disconnect message */
948 int reason = GET_32BIT(pktin.data + 6);
949 unsigned msglen = GET_32BIT(pktin.data + 10);
951 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
952 sprintf(buf, "Received disconnect message (%s)",
953 ssh2_disconnect_reasons[reason]);
955 sprintf(buf, "Received disconnect message (unknown type %d)",
959 strcpy(buf, "Disconnection message text: ");
960 nowlen = strlen(buf);
961 if (msglen > sizeof(buf) - nowlen - 1)
962 msglen = sizeof(buf) - nowlen - 1;
963 memcpy(buf + nowlen, pktin.data + 14, msglen);
964 buf[nowlen + msglen] = '\0';
966 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
968 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
969 ssh2_disconnect_reasons[reason] : "unknown",
977 static void ssh1_pktout_size(int len)
981 len += 5; /* type and CRC */
985 pktout.length = len - 5;
986 if (pktout.maxlen < biglen) {
987 pktout.maxlen = biglen;
989 /* Allocate enough buffer space for extra block
990 * for MS CryptEncrypt() */
991 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
992 srealloc(pktout.data, biglen + 12));
994 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
995 srealloc(pktout.data, biglen + 4));
998 fatalbox("Out of memory");
1000 pktout.body = pktout.data + 4 + pad + 1;
1003 static void s_wrpkt_start(int type, int len)
1005 ssh1_pktout_size(len);
1009 static int s_wrpkt_prepare(void)
1011 int pad, len, biglen, i;
1014 pktout.body[-1] = pktout.type;
1016 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1017 pktout.body, pktout.length);
1019 if (ssh1_compressing) {
1020 unsigned char *compblk;
1022 zlib_compress_block(pktout.body - 1, pktout.length + 1,
1023 &compblk, &complen);
1024 ssh1_pktout_size(complen - 1);
1025 memcpy(pktout.body - 1, compblk, complen);
1029 len = pktout.length + 5; /* type and CRC */
1030 pad = 8 - (len % 8);
1033 for (i = 0; i < pad; i++)
1034 pktout.data[i + 4] = random_byte();
1035 crc = crc32(pktout.data + 4, biglen - 4);
1036 PUT_32BIT(pktout.data + biglen, crc);
1037 PUT_32BIT(pktout.data, len);
1040 cipher->encrypt(pktout.data + 4, biglen);
1045 static void s_wrpkt(void)
1048 len = s_wrpkt_prepare();
1049 backlog = sk_write(s, pktout.data, len);
1050 if (backlog > SSH_MAX_BACKLOG)
1051 ssh_throttle_all(1, backlog);
1054 static void s_wrpkt_defer(void)
1057 len = s_wrpkt_prepare();
1058 if (deferred_len + len > deferred_size) {
1059 deferred_size = deferred_len + len + 128;
1060 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1062 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1063 deferred_len += len;
1067 * Construct a packet with the specified contents.
1069 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1071 unsigned char *p, *argp, argchar;
1072 unsigned long argint;
1073 int pktlen, argtype, arglen;
1077 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1080 (void) va_arg(ap1, int);
1084 (void) va_arg(ap1, char);
1088 (void) va_arg(ap1, unsigned char *);
1089 arglen = va_arg(ap1, int);
1093 argp = va_arg(ap1, unsigned char *);
1094 arglen = strlen(argp);
1095 pktlen += 4 + arglen;
1098 bn = va_arg(ap1, Bignum);
1099 pktlen += ssh1_bignum_length(bn);
1106 s_wrpkt_start(pkttype, pktlen);
1109 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1112 argint = va_arg(ap2, int);
1113 PUT_32BIT(p, argint);
1117 argchar = va_arg(ap2, unsigned char);
1122 argp = va_arg(ap2, unsigned char *);
1123 arglen = va_arg(ap2, int);
1124 memcpy(p, argp, arglen);
1128 argp = va_arg(ap2, unsigned char *);
1129 arglen = strlen(argp);
1130 PUT_32BIT(p, arglen);
1131 memcpy(p + 4, argp, arglen);
1135 bn = va_arg(ap2, Bignum);
1136 p += ssh1_write_bignum(p, bn);
1142 static void send_packet(int pkttype, ...)
1145 va_start(ap1, pkttype);
1146 va_start(ap2, pkttype);
1147 construct_packet(pkttype, ap1, ap2);
1151 static void defer_packet(int pkttype, ...)
1154 va_start(ap1, pkttype);
1155 va_start(ap2, pkttype);
1156 construct_packet(pkttype, ap1, ap2);
1160 static int ssh_versioncmp(char *a, char *b)
1163 unsigned long av, bv;
1165 av = strtoul(a, &ae, 10);
1166 bv = strtoul(b, &be, 10);
1168 return (av < bv ? -1 : +1);
1173 av = strtoul(ae, &ae, 10);
1174 bv = strtoul(be, &be, 10);
1176 return (av < bv ? -1 : +1);
1182 * Utility routines for putting an SSH-protocol `string' and
1183 * `uint32' into a SHA state.
1186 static void sha_string(SHA_State * s, void *str, int len)
1188 unsigned char lenblk[4];
1189 PUT_32BIT(lenblk, len);
1190 SHA_Bytes(s, lenblk, 4);
1191 SHA_Bytes(s, str, len);
1194 static void sha_uint32(SHA_State * s, unsigned i)
1196 unsigned char intblk[4];
1197 PUT_32BIT(intblk, i);
1198 SHA_Bytes(s, intblk, 4);
1202 * SSH2 packet construction functions.
1204 static void ssh2_pkt_ensure(int length)
1206 if (pktout.maxlen < length) {
1207 pktout.maxlen = length + 256;
1210 NULL ? smalloc(pktout.maxlen +
1211 APIEXTRA) : srealloc(pktout.data,
1215 fatalbox("Out of memory");
1218 static void ssh2_pkt_adddata(void *data, int len)
1220 pktout.length += len;
1221 ssh2_pkt_ensure(pktout.length);
1222 memcpy(pktout.data + pktout.length - len, data, len);
1224 static void ssh2_pkt_addbyte(unsigned char byte)
1226 ssh2_pkt_adddata(&byte, 1);
1228 static void ssh2_pkt_init(int pkt_type)
1231 ssh2_pkt_addbyte((unsigned char) pkt_type);
1233 static void ssh2_pkt_addbool(unsigned char value)
1235 ssh2_pkt_adddata(&value, 1);
1237 static void ssh2_pkt_adduint32(unsigned long value)
1240 PUT_32BIT(x, value);
1241 ssh2_pkt_adddata(x, 4);
1243 static void ssh2_pkt_addstring_start(void)
1245 ssh2_pkt_adduint32(0);
1246 pktout.savedpos = pktout.length;
1248 static void ssh2_pkt_addstring_str(char *data)
1250 ssh2_pkt_adddata(data, strlen(data));
1251 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1252 pktout.length - pktout.savedpos);
1254 static void ssh2_pkt_addstring_data(char *data, int len)
1256 ssh2_pkt_adddata(data, len);
1257 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1258 pktout.length - pktout.savedpos);
1260 static void ssh2_pkt_addstring(char *data)
1262 ssh2_pkt_addstring_start();
1263 ssh2_pkt_addstring_str(data);
1265 static char *ssh2_mpint_fmt(Bignum b, int *len)
1268 int i, n = (bignum_bitcount(b) + 7) / 8;
1271 fatalbox("out of memory");
1273 for (i = 1; i <= n; i++)
1274 p[i] = bignum_byte(b, n - i);
1276 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1278 memmove(p, p + i, n + 1 - i);
1282 static void ssh2_pkt_addmp(Bignum b)
1286 p = ssh2_mpint_fmt(b, &len);
1287 ssh2_pkt_addstring_start();
1288 ssh2_pkt_addstring_data(p, len);
1293 * Construct an SSH2 final-form packet: compress it, encrypt it,
1294 * put the MAC on it. Final packet, ready to be sent, is stored in
1295 * pktout.data. Total length is returned.
1297 static int ssh2_pkt_construct(void)
1299 int cipherblk, maclen, padding, i;
1300 static unsigned long outgoing_sequence = 0;
1302 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1303 pktout.data + 6, pktout.length - 6);
1306 * Compress packet payload.
1309 unsigned char *newpayload;
1311 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1312 &newpayload, &newlen)) {
1314 ssh2_pkt_adddata(newpayload, newlen);
1320 * Add padding. At least four bytes, and must also bring total
1321 * length (minus MAC) up to a multiple of the block size.
1323 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1324 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1327 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1328 maclen = csmac ? csmac->len : 0;
1329 ssh2_pkt_ensure(pktout.length + padding + maclen);
1330 pktout.data[4] = padding;
1331 for (i = 0; i < padding; i++)
1332 pktout.data[pktout.length + i] = random_byte();
1333 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1335 csmac->generate(pktout.data, pktout.length + padding,
1337 outgoing_sequence++; /* whether or not we MACed */
1340 cscipher->encrypt(pktout.data, pktout.length + padding);
1342 /* Ready-to-send packet starts at pktout.data. We return length. */
1343 return pktout.length + padding + maclen;
1347 * Construct and send an SSH2 packet immediately.
1349 static void ssh2_pkt_send(void)
1353 len = ssh2_pkt_construct();
1354 backlog = sk_write(s, pktout.data, len);
1355 if (backlog > SSH_MAX_BACKLOG)
1356 ssh_throttle_all(1, backlog);
1360 * Construct an SSH2 packet and add it to a deferred data block.
1361 * Useful for sending multiple packets in a single sk_write() call,
1362 * to prevent a traffic-analysing listener from being able to work
1363 * out the length of any particular packet (such as the password
1366 * Note that because SSH2 sequence-numbers its packets, this can
1367 * NOT be used as an m4-style `defer' allowing packets to be
1368 * constructed in one order and sent in another.
1370 static void ssh2_pkt_defer(void)
1372 int len = ssh2_pkt_construct();
1373 if (deferred_len + len > deferred_size) {
1374 deferred_size = deferred_len + len + 128;
1375 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1377 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1378 deferred_len += len;
1382 * Send the whole deferred data block constructed by
1383 * ssh2_pkt_defer() or SSH1's defer_packet().
1385 static void ssh_pkt_defersend(void)
1388 backlog = sk_write(s, deferred_send_data, deferred_len);
1389 deferred_len = deferred_size = 0;
1390 sfree(deferred_send_data);
1391 deferred_send_data = NULL;
1392 if (backlog > SSH_MAX_BACKLOG)
1393 ssh_throttle_all(1, backlog);
1397 void bndebug(char *string, Bignum b)
1401 p = ssh2_mpint_fmt(b, &len);
1402 debug(("%s", string));
1403 for (i = 0; i < len; i++)
1404 debug((" %02x", p[i]));
1410 static void sha_mpint(SHA_State * s, Bignum b)
1414 p = ssh2_mpint_fmt(b, &len);
1415 sha_string(s, p, len);
1420 * SSH2 packet decode functions.
1422 static unsigned long ssh2_pkt_getuint32(void)
1424 unsigned long value;
1425 if (pktin.length - pktin.savedpos < 4)
1426 return 0; /* arrgh, no way to decline (FIXME?) */
1427 value = GET_32BIT(pktin.data + pktin.savedpos);
1428 pktin.savedpos += 4;
1431 static int ssh2_pkt_getbool(void)
1433 unsigned long value;
1434 if (pktin.length - pktin.savedpos < 1)
1435 return 0; /* arrgh, no way to decline (FIXME?) */
1436 value = pktin.data[pktin.savedpos] != 0;
1440 static void ssh2_pkt_getstring(char **p, int *length)
1443 if (pktin.length - pktin.savedpos < 4)
1445 *length = GET_32BIT(pktin.data + pktin.savedpos);
1446 pktin.savedpos += 4;
1447 if (pktin.length - pktin.savedpos < *length)
1449 *p = pktin.data + pktin.savedpos;
1450 pktin.savedpos += *length;
1452 static Bignum ssh2_pkt_getmp(void)
1458 ssh2_pkt_getstring(&p, &length);
1462 bombout(("internal error: Can't handle negative mpints"));
1465 b = bignum_from_bytes(p, length);
1470 * Examine the remote side's version string and compare it against
1471 * a list of known buggy implementations.
1473 static void ssh_detect_bugs(char *vstring)
1475 char *imp; /* pointer to implementation part */
1477 imp += strcspn(imp, "-");
1479 imp += strcspn(imp, "-");
1482 ssh_remote_bugs = 0;
1484 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1485 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1486 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
1488 * These versions don't support SSH1_MSG_IGNORE, so we have
1489 * to use a different defence against password length
1492 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1493 logevent("We believe remote version has SSH1 ignore bug");
1496 if (!strcmp(imp, "Cisco-1.25")) {
1498 * These versions need a plain password sent; they can't
1499 * handle having a null and a random length of data after
1502 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1503 logevent("We believe remote version needs a plain SSH1 password");
1506 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1507 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1508 !strncmp(imp, "2.1 ", 4)) {
1510 * These versions have the HMAC bug.
1512 ssh_remote_bugs |= BUG_SSH2_HMAC;
1513 logevent("We believe remote version has SSH2 HMAC bug");
1517 static int do_ssh_init(unsigned char c)
1520 static char version[10];
1521 static char *vstring;
1522 static int vstrsize;
1528 /* Search for the string "SSH-" in the input. */
1531 static const int transS[] = { 1, 2, 2, 1 };
1532 static const int transH[] = { 0, 0, 3, 0 };
1533 static const int transminus[] = { 0, 0, 0, -1 };
1544 crReturn(1); /* get another character */
1548 vstring = smalloc(vstrsize);
1549 strcpy(vstring, "SSH-");
1553 crReturn(1); /* get another char */
1554 if (vslen >= vstrsize - 1) {
1556 vstring = srealloc(vstring, vstrsize);
1558 vstring[vslen++] = c;
1563 } else if (i < sizeof(version) - 1)
1565 } else if (c == '\n')
1569 ssh_agentfwd_enabled = FALSE;
1570 rdpkt2_state.incoming_sequence = 0;
1573 vlog = smalloc(20 + vslen);
1574 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
1575 sprintf(vlog, "Server version: %s", vstring);
1577 ssh_detect_bugs(vstring);
1581 * Server version "1.99" means we can choose whether we use v1
1582 * or v2 protocol. Choice is based on cfg.sshprot.
1584 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1586 * This is a v2 server. Begin v2 protocol.
1588 char verstring[80], vlog[100];
1589 sprintf(verstring, "SSH-2.0-%s", sshver);
1590 SHA_Init(&exhashbase);
1592 * Hash our version string and their version string.
1594 sha_string(&exhashbase, verstring, strlen(verstring));
1595 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1596 sprintf(vlog, "We claim version: %s", verstring);
1598 strcat(verstring, "\n");
1599 logevent("Using SSH protocol version 2");
1600 sk_write(s, verstring, strlen(verstring));
1601 ssh_protocol = ssh2_protocol;
1603 s_rdpkt = ssh2_rdpkt;
1606 * This is a v1 server. Begin v1 protocol.
1608 char verstring[80], vlog[100];
1609 sprintf(verstring, "SSH-%s-%s",
1610 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1612 sprintf(vlog, "We claim version: %s", verstring);
1614 strcat(verstring, "\n");
1615 logevent("Using SSH protocol version 1");
1616 sk_write(s, verstring, strlen(verstring));
1617 ssh_protocol = ssh1_protocol;
1619 s_rdpkt = ssh1_rdpkt;
1621 ssh_state = SSH_STATE_BEFORE_SIZE;
1628 static void ssh_gotdata(unsigned char *data, int datalen)
1633 * To begin with, feed the characters one by one to the
1634 * protocol initialisation / selection function do_ssh_init().
1635 * When that returns 0, we're done with the initial greeting
1636 * exchange and can move on to packet discipline.
1641 crReturnV; /* more data please */
1642 ret = do_ssh_init(*data);
1650 * We emerge from that loop when the initial negotiation is
1651 * over and we have selected an s_rdpkt function. Now pass
1652 * everything to s_rdpkt, and then pass the resulting packets
1653 * to the proper protocol handler.
1658 while (datalen > 0) {
1659 if (s_rdpkt(&data, &datalen) == 0) {
1660 if (ssh_state == SSH_STATE_CLOSED) {
1663 ssh_protocol(NULL, 0, 1);
1664 if (ssh_state == SSH_STATE_CLOSED) {
1674 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1677 ssh_state = SSH_STATE_CLOSED;
1683 /* A socket error has occurred. */
1684 connection_fatal(error_msg);
1686 /* Otherwise, the remote side closed the connection normally. */
1691 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1693 ssh_gotdata(data, len);
1694 if (ssh_state == SSH_STATE_CLOSED) {
1704 static void ssh_sent(Plug plug, int bufsize)
1707 * If the send backlog on the SSH socket itself clears, we
1708 * should unthrottle the whole world if it was throttled.
1710 if (bufsize < SSH_MAX_BACKLOG)
1711 ssh_throttle_all(0, bufsize);
1715 * Connect to specified host and port.
1716 * Returns an error message, or NULL on success.
1717 * Also places the canonical host name into `realhost'. It must be
1718 * freed by the caller.
1720 static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
1722 static struct plug_function_table fn_table = {
1727 }, *fn_table_ptr = &fn_table;
1736 savedhost = smalloc(1 + strlen(host));
1738 fatalbox("Out of memory");
1739 strcpy(savedhost, host);
1742 port = 22; /* default ssh port */
1757 sprintf(buf, "Looking up host \"%.170s\"", host);
1760 addr = sk_namelookup(host, realhost);
1761 if ((err = sk_addr_error(addr)))
1765 *realhost = strdup(FWhost);
1772 char buf[200], addrbuf[100];
1773 sk_getaddr(addr, addrbuf, 100);
1774 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1777 s = sk_new(addr, port, 0, 1, nodelay, &fn_table_ptr);
1778 if ((err = sk_socket_error(s)))
1782 sk_write(s, "connect ", 8);
1783 sk_write(s, FWhost, strlen(FWhost));
1786 sprintf(buf, " %d\n", FWport);
1787 sk_write(s, buf, strlen(buf));
1795 * Throttle or unthrottle the SSH connection.
1797 static void ssh1_throttle(int adjust)
1799 int old_count = ssh1_throttle_count;
1800 ssh1_throttle_count += adjust;
1801 assert(ssh1_throttle_count >= 0);
1802 if (ssh1_throttle_count && !old_count) {
1803 sk_set_frozen(s, 1);
1804 } else if (!ssh1_throttle_count && old_count) {
1805 sk_set_frozen(s, 0);
1810 * Throttle or unthrottle _all_ local data streams (for when sends
1811 * on the SSH connection itself back up).
1813 static void ssh_throttle_all(int enable, int bufsize)
1816 struct ssh_channel *c;
1818 if (enable == ssh_throttled_all)
1820 ssh_throttled_all = enable;
1821 ssh_overall_bufsize = bufsize;
1824 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1826 case CHAN_MAINSESSION:
1828 * This is treated separately, outside the switch.
1832 x11_override_throttle(c->u.x11.s, enable);
1835 /* Agent channels require no buffer management. */
1838 pfd_override_throttle(c->u.x11.s, enable);
1845 * Handle the key exchange and user authentication phases.
1847 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1851 static unsigned char *rsabuf, *keystr1, *keystr2;
1852 unsigned char cookie[8];
1853 struct RSAKey servkey, hostkey;
1854 struct MD5Context md5c;
1855 static unsigned long supported_ciphers_mask, supported_auths_mask;
1856 static int tried_publickey;
1857 static int tis_auth_refused, ccard_auth_refused;
1858 static unsigned char session_id[16];
1859 static int cipher_type;
1860 static char username[100];
1867 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1868 bombout(("Public key packet not received"));
1872 logevent("Received public keys");
1874 memcpy(cookie, pktin.body, 8);
1876 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1877 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1880 * Log the host key fingerprint.
1884 logevent("Host key fingerprint is:");
1885 strcpy(logmsg, " ");
1886 hostkey.comment = NULL;
1887 rsa_fingerprint(logmsg + strlen(logmsg),
1888 sizeof(logmsg) - strlen(logmsg), &hostkey);
1892 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
1893 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
1894 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
1896 ssh1_local_protoflags =
1897 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
1898 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
1901 MD5Update(&md5c, keystr2, hostkey.bytes);
1902 MD5Update(&md5c, keystr1, servkey.bytes);
1903 MD5Update(&md5c, pktin.body, 8);
1904 MD5Final(session_id, &md5c);
1906 for (i = 0; i < 32; i++)
1907 session_key[i] = random_byte();
1909 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1911 rsabuf = smalloc(len);
1913 fatalbox("Out of memory");
1916 * Verify the host key.
1920 * First format the key into a string.
1922 int len = rsastr_len(&hostkey);
1923 char fingerprint[100];
1924 char *keystr = smalloc(len);
1926 fatalbox("Out of memory");
1927 rsastr_fmt(keystr, &hostkey);
1928 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
1929 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
1934 for (i = 0; i < 32; i++) {
1935 rsabuf[i] = session_key[i];
1937 rsabuf[i] ^= session_id[i];
1940 if (hostkey.bytes > servkey.bytes) {
1941 rsaencrypt(rsabuf, 32, &servkey);
1942 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1944 rsaencrypt(rsabuf, 32, &hostkey);
1945 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1948 logevent("Encrypted session key");
1951 int cipher_chosen = 0, warn = 0;
1952 char *cipher_string = NULL;
1953 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
1954 int next_cipher = cfg.ssh_cipherlist[i];
1955 if (next_cipher == CIPHER_WARN) {
1956 /* If/when we choose a cipher, warn about it */
1958 } else if (next_cipher == CIPHER_AES) {
1959 /* XXX Probably don't need to mention this. */
1960 logevent("AES not supported in SSH1, skipping");
1962 switch (next_cipher) {
1963 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
1964 cipher_string = "3DES"; break;
1965 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
1966 cipher_string = "Blowfish"; break;
1967 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
1968 cipher_string = "single-DES"; break;
1970 if (supported_ciphers_mask & (1 << cipher_type))
1974 if (!cipher_chosen) {
1975 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
1976 bombout(("Server violates SSH 1 protocol by not "
1977 "supporting 3DES encryption"));
1979 /* shouldn't happen */
1980 bombout(("No supported ciphers found"));
1984 /* Warn about chosen cipher if necessary. */
1986 askcipher(cipher_string, 0);
1989 switch (cipher_type) {
1990 case SSH_CIPHER_3DES:
1991 logevent("Using 3DES encryption");
1993 case SSH_CIPHER_DES:
1994 logevent("Using single-DES encryption");
1996 case SSH_CIPHER_BLOWFISH:
1997 logevent("Using Blowfish encryption");
2001 send_packet(SSH1_CMSG_SESSION_KEY,
2002 PKT_CHAR, cipher_type,
2003 PKT_DATA, cookie, 8,
2004 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2005 PKT_DATA, rsabuf, len,
2006 PKT_INT, ssh1_local_protoflags, PKT_END);
2008 logevent("Trying to enable encryption...");
2012 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2013 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
2014 cipher->sesskey(session_key);
2018 if (pktin.type != SSH1_SMSG_SUCCESS) {
2019 bombout(("Encryption not successfully enabled"));
2023 logevent("Successfully started encryption");
2029 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2031 if (!ssh_get_line("login as: ",
2032 username, sizeof(username), FALSE)) {
2034 * get_line failed to get a username.
2037 logevent("No username provided. Abandoning session.");
2038 ssh_state = SSH_STATE_CLOSED;
2042 c_write_str("login as: ");
2045 crWaitUntil(!ispkt);
2047 switch (c = *in++) {
2056 c_write_str("\b \b");
2063 c_write_str("\b \b");
2073 if (((c >= ' ' && c <= '~') ||
2074 ((unsigned char) c >= 160))
2075 && pos < sizeof(username)-1) {
2076 username[pos++] = c;
2082 c_write_str("\r\n");
2083 username[strcspn(username, "\n\r")] = '\0';
2086 strncpy(username, cfg.username, 99);
2087 username[99] = '\0';
2090 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2092 char userlog[22 + sizeof(username)];
2093 sprintf(userlog, "Sent username \"%s\"", username);
2095 if (flags & FLAG_INTERACTIVE &&
2096 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2097 strcat(userlog, "\r\n");
2098 c_write_str(userlog);
2105 tried_publickey = 0;
2106 tis_auth_refused = ccard_auth_refused = 0;
2108 while (pktin.type == SSH1_SMSG_FAILURE) {
2109 static char password[100];
2110 static char prompt[200];
2113 static int pwpkt_type;
2114 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2116 if (agent_exists()) {
2118 * Attempt RSA authentication using Pageant.
2120 static unsigned char request[5], *response, *p;
2121 static int responselen;
2122 static int i, nkeys;
2123 static int authed = FALSE;
2126 logevent("Pageant is running. Requesting keys.");
2128 /* Request the keys held by the agent. */
2129 PUT_32BIT(request, 1);
2130 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2131 agent_query(request, 5, &r, &responselen);
2132 response = (unsigned char *) r;
2133 if (response && responselen >= 5 &&
2134 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2136 nkeys = GET_32BIT(p);
2140 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2143 for (i = 0; i < nkeys; i++) {
2144 static struct RSAKey key;
2145 static Bignum challenge;
2146 static char *commentp;
2147 static int commentlen;
2151 sprintf(buf, "Trying Pageant key #%d", i);
2155 p += ssh1_read_bignum(p, &key.exponent);
2156 p += ssh1_read_bignum(p, &key.modulus);
2157 commentlen = GET_32BIT(p);
2161 send_packet(SSH1_CMSG_AUTH_RSA,
2162 PKT_BIGNUM, key.modulus, PKT_END);
2164 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2165 logevent("Key refused");
2168 logevent("Received RSA challenge");
2169 ssh1_read_bignum(pktin.body, &challenge);
2171 char *agentreq, *q, *ret;
2174 len = 1 + 4; /* message type, bit count */
2175 len += ssh1_bignum_length(key.exponent);
2176 len += ssh1_bignum_length(key.modulus);
2177 len += ssh1_bignum_length(challenge);
2178 len += 16; /* session id */
2179 len += 4; /* response format */
2180 agentreq = smalloc(4 + len);
2181 PUT_32BIT(agentreq, len);
2183 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2184 PUT_32BIT(q, bignum_bitcount(key.modulus));
2186 q += ssh1_write_bignum(q, key.exponent);
2187 q += ssh1_write_bignum(q, key.modulus);
2188 q += ssh1_write_bignum(q, challenge);
2189 memcpy(q, session_id, 16);
2191 PUT_32BIT(q, 1); /* response format */
2192 agent_query(agentreq, len + 4, &vret, &retlen);
2196 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2197 logevent("Sending Pageant's response");
2198 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2199 PKT_DATA, ret + 5, 16,
2203 if (pktin.type == SSH1_SMSG_SUCCESS) {
2205 ("Pageant's response accepted");
2206 if (flags & FLAG_VERBOSE) {
2208 ("Authenticated using RSA key \"");
2209 c_write(commentp, commentlen);
2210 c_write_str("\" from agent\r\n");
2215 ("Pageant's response not accepted");
2218 ("Pageant failed to answer challenge");
2222 logevent("No reply received from Pageant");
2225 freebn(key.exponent);
2226 freebn(key.modulus);
2235 if (*cfg.keyfile && !tried_publickey)
2236 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2238 if (cfg.try_tis_auth &&
2239 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2240 !tis_auth_refused) {
2241 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2242 logevent("Requested TIS authentication");
2243 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2245 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2246 logevent("TIS authentication declined");
2247 if (flags & FLAG_INTERACTIVE)
2248 c_write_str("TIS authentication refused.\r\n");
2249 tis_auth_refused = 1;
2252 int challengelen = ((pktin.body[0] << 24) |
2253 (pktin.body[1] << 16) |
2254 (pktin.body[2] << 8) |
2256 logevent("Received TIS challenge");
2257 if (challengelen > sizeof(prompt) - 1)
2258 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2259 memcpy(prompt, pktin.body + 4, challengelen);
2260 /* Prompt heuristic comes from OpenSSH */
2261 strncpy(prompt + challengelen,
2262 memchr(prompt, '\n', challengelen) ?
2263 "": "\r\nResponse: ",
2264 (sizeof prompt) - challengelen);
2265 prompt[(sizeof prompt) - 1] = '\0';
2268 if (cfg.try_tis_auth &&
2269 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2270 !ccard_auth_refused) {
2271 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2272 logevent("Requested CryptoCard authentication");
2273 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2275 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2276 logevent("CryptoCard authentication declined");
2277 c_write_str("CryptoCard authentication refused.\r\n");
2278 ccard_auth_refused = 1;
2281 int challengelen = ((pktin.body[0] << 24) |
2282 (pktin.body[1] << 16) |
2283 (pktin.body[2] << 8) |
2285 logevent("Received CryptoCard challenge");
2286 if (challengelen > sizeof(prompt) - 1)
2287 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2288 memcpy(prompt, pktin.body + 4, challengelen);
2289 strncpy(prompt + challengelen,
2290 memchr(prompt, '\n', challengelen) ?
2291 "" : "\r\nResponse: ",
2292 sizeof(prompt) - challengelen);
2293 prompt[sizeof(prompt) - 1] = '\0';
2296 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2297 sprintf(prompt, "%.90s@%.90s's password: ",
2298 username, savedhost);
2300 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2301 char *comment = NULL;
2302 if (flags & FLAG_VERBOSE)
2303 c_write_str("Trying public key authentication.\r\n");
2304 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2305 if (flags & FLAG_VERBOSE)
2306 c_write_str("No passphrase required.\r\n");
2309 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2314 * Show password prompt, having first obtained it via a TIS
2315 * or CryptoCard exchange if we're doing TIS or CryptoCard
2319 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2321 * get_line failed to get a password (for example
2322 * because one was supplied on the command line
2323 * which has already failed to work). Terminate.
2325 send_packet(SSH1_MSG_DISCONNECT,
2326 PKT_STR, "No more passwords available to try",
2328 connection_fatal("Unable to authenticate");
2329 ssh_state = SSH_STATE_CLOSED;
2333 /* Prompt may have come from server. We've munged it a bit, so
2334 * we know it to be zero-terminated at least once. */
2335 c_write_untrusted(prompt, strlen(prompt));
2339 crWaitUntil(!ispkt);
2341 switch (c = *in++) {
2362 if (pos < sizeof(password)-1)
2363 password[pos++] = c;
2367 c_write_str("\r\n");
2371 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2373 * Try public key authentication with the specified
2376 static struct RSAKey pubkey;
2377 static Bignum challenge, response;
2379 static unsigned char buffer[32];
2381 tried_publickey = 1;
2382 i = loadrsakey(cfg.keyfile, &pubkey, password);
2384 c_write_str("Couldn't load private key from ");
2385 c_write_str(cfg.keyfile);
2386 c_write_str(".\r\n");
2387 continue; /* go and try password */
2390 c_write_str("Wrong passphrase.\r\n");
2391 tried_publickey = 0;
2392 continue; /* try again */
2396 * Send a public key attempt.
2398 send_packet(SSH1_CMSG_AUTH_RSA,
2399 PKT_BIGNUM, pubkey.modulus, PKT_END);
2402 if (pktin.type == SSH1_SMSG_FAILURE) {
2403 c_write_str("Server refused our public key.\r\n");
2404 continue; /* go and try password */
2406 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2407 bombout(("Bizarre response to offer of public key"));
2410 ssh1_read_bignum(pktin.body, &challenge);
2411 response = rsadecrypt(challenge, &pubkey);
2412 freebn(pubkey.private_exponent); /* burn the evidence */
2414 for (i = 0; i < 32; i++) {
2415 buffer[i] = bignum_byte(response, 31 - i);
2419 MD5Update(&md5c, buffer, 32);
2420 MD5Update(&md5c, session_id, 16);
2421 MD5Final(buffer, &md5c);
2423 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2424 PKT_DATA, buffer, 16, PKT_END);
2427 if (pktin.type == SSH1_SMSG_FAILURE) {
2428 if (flags & FLAG_VERBOSE)
2430 ("Failed to authenticate with our public key.\r\n");
2431 continue; /* go and try password */
2432 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2434 ("Bizarre response to RSA authentication response"));
2438 break; /* we're through! */
2440 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2442 * Defence against traffic analysis: we send a
2443 * whole bunch of packets containing strings of
2444 * different lengths. One of these strings is the
2445 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2446 * The others are all random data in
2447 * SSH1_MSG_IGNORE packets. This way a passive
2448 * listener can't tell which is the password, and
2449 * hence can't deduce the password length.
2451 * Anybody with a password length greater than 16
2452 * bytes is going to have enough entropy in their
2453 * password that a listener won't find it _that_
2454 * much help to know how long it is. So what we'll
2457 * - if password length < 16, we send 15 packets
2458 * containing string lengths 1 through 15
2460 * - otherwise, we let N be the nearest multiple
2461 * of 8 below the password length, and send 8
2462 * packets containing string lengths N through
2463 * N+7. This won't obscure the order of
2464 * magnitude of the password length, but it will
2465 * introduce a bit of extra uncertainty.
2467 * A few servers (the old 1.2.18 through 1.2.22)
2468 * can't deal with SSH1_MSG_IGNORE. For these
2469 * servers, we need an alternative defence. We make
2470 * use of the fact that the password is interpreted
2471 * as a C string: so we can append a NUL, then some
2474 * One server (a Cisco one) can deal with neither
2475 * SSH1_MSG_IGNORE _nor_ a padded password string.
2476 * For this server we are left with no defences
2477 * against password length sniffing.
2479 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2481 * The server can deal with SSH1_MSG_IGNORE, so
2482 * we can use the primary defence.
2484 int bottom, top, pwlen, i;
2487 pwlen = strlen(password);
2489 bottom = 0; /* zero length passwords are OK! :-) */
2492 bottom = pwlen & ~7;
2496 assert(pwlen >= bottom && pwlen <= top);
2498 randomstr = smalloc(top + 1);
2500 for (i = bottom; i <= top; i++) {
2502 defer_packet(pwpkt_type, PKT_STR, password,
2505 for (j = 0; j < i; j++) {
2507 randomstr[j] = random_byte();
2508 } while (randomstr[j] == '\0');
2510 randomstr[i] = '\0';
2511 defer_packet(SSH1_MSG_IGNORE,
2512 PKT_STR, randomstr, PKT_END);
2515 logevent("Sending password with camouflage packets");
2516 ssh_pkt_defersend();
2518 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2520 * The server can't deal with SSH1_MSG_IGNORE
2521 * but can deal with padded passwords, so we
2522 * can use the secondary defence.
2528 len = strlen(password);
2529 if (len < sizeof(string)) {
2531 strcpy(string, password);
2532 len++; /* cover the zero byte */
2533 while (len < sizeof(string)) {
2534 string[len++] = (char) random_byte();
2539 logevent("Sending length-padded password");
2540 send_packet(pwpkt_type, PKT_INT, len,
2541 PKT_DATA, s, len, PKT_END);
2544 * The server has _both_
2545 * BUG_CHOKES_ON_SSH1_IGNORE and
2546 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2547 * therefore nothing we can do.
2550 len = strlen(password);
2551 logevent("Sending unpadded password");
2552 send_packet(pwpkt_type, PKT_INT, len,
2553 PKT_DATA, password, len, PKT_END);
2556 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2559 logevent("Sent password");
2560 memset(password, 0, strlen(password));
2562 if (pktin.type == SSH1_SMSG_FAILURE) {
2563 if (flags & FLAG_VERBOSE)
2564 c_write_str("Access denied\r\n");
2565 logevent("Authentication refused");
2566 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2567 logevent("Received disconnect request");
2568 ssh_state = SSH_STATE_CLOSED;
2570 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2571 bombout(("Strange packet received, type %d", pktin.type));
2576 logevent("Authentication successful");
2581 void sshfwd_close(struct ssh_channel *c)
2583 if (c && !c->closes) {
2585 * If the channel's remoteid is -1, we have sent
2586 * CHANNEL_OPEN for this channel, but it hasn't even been
2587 * acknowledged by the server. So we must set a close flag
2588 * on it now, and then when the server acks the channel
2589 * open, we can close it then.
2591 if (c->remoteid != -1) {
2592 if (ssh_version == 1) {
2593 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2596 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2597 ssh2_pkt_adduint32(c->remoteid);
2602 if (c->type == CHAN_X11) {
2604 logevent("Forwarded X11 connection terminated");
2605 } else if (c->type == CHAN_SOCKDATA ||
2606 c->type == CHAN_SOCKDATA_DORMANT) {
2608 logevent("Forwarded port closed");
2613 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2615 if (ssh_version == 1) {
2616 send_packet(SSH1_MSG_CHANNEL_DATA,
2617 PKT_INT, c->remoteid,
2618 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2620 * In SSH1 we can return 0 here - implying that forwarded
2621 * connections are never individually throttled - because
2622 * the only circumstance that can cause throttling will be
2623 * the whole SSH connection backing up, in which case
2624 * _everything_ will be throttled as a whole.
2628 ssh2_add_channel_data(c, buf, len);
2629 return ssh2_try_send(c);
2633 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2635 if (ssh_version == 1) {
2636 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2637 c->v.v1.throttling = 0;
2641 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2645 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2651 while (!do_ssh1_login(in, inlen, ispkt)) {
2654 if (ssh_state == SSH_STATE_CLOSED)
2657 if (cfg.agentfwd && agent_exists()) {
2658 logevent("Requesting agent forwarding");
2659 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2663 if (pktin.type != SSH1_SMSG_SUCCESS
2664 && pktin.type != SSH1_SMSG_FAILURE) {
2665 bombout(("Protocol confusion"));
2667 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2668 logevent("Agent forwarding refused");
2670 logevent("Agent forwarding enabled");
2671 ssh_agentfwd_enabled = TRUE;
2675 if (cfg.x11_forward) {
2676 char proto[20], data[64];
2677 logevent("Requesting X11 forwarding");
2678 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2679 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2680 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2681 PKT_STR, proto, PKT_STR, data,
2682 PKT_INT, 0, PKT_END);
2684 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2685 PKT_STR, proto, PKT_STR, data, PKT_END);
2690 if (pktin.type != SSH1_SMSG_SUCCESS
2691 && pktin.type != SSH1_SMSG_FAILURE) {
2692 bombout(("Protocol confusion"));
2694 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2695 logevent("X11 forwarding refused");
2697 logevent("X11 forwarding enabled");
2698 ssh_X11_fwd_enabled = TRUE;
2706 char sports[256], dports[256], host[256];
2709 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2710 /* Add port forwardings. */
2715 while (*e && *e != '\t')
2721 while (*e && *e != ':')
2731 dport = atoi(dports);
2732 sport = atoi(sports);
2733 if (sport && dport) {
2735 pfd_addforward(host, dport, sport);
2736 sprintf(buf, "Local port %d forwarding to %s:%d",
2737 sport, host, dport);
2740 struct ssh_rportfwd *pf;
2741 pf = smalloc(sizeof(*pf));
2742 strcpy(pf->dhost, host);
2744 if (add234(ssh_rportfwds, pf) != pf) {
2746 "Duplicate remote port forwarding to %s:%d",
2751 sprintf(buf, "Requesting remote port %d forward to %s:%d",
2752 sport, host, dport);
2754 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2766 send_packet(SSH1_CMSG_REQUEST_PTY,
2767 PKT_STR, cfg.termtype,
2768 PKT_INT, rows, PKT_INT, cols,
2769 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2770 ssh_state = SSH_STATE_INTERMED;
2774 if (pktin.type != SSH1_SMSG_SUCCESS
2775 && pktin.type != SSH1_SMSG_FAILURE) {
2776 bombout(("Protocol confusion"));
2778 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2779 c_write_str("Server refused to allocate pty\r\n");
2780 ssh_editing = ssh_echoing = 1;
2782 logevent("Allocated pty");
2784 ssh_editing = ssh_echoing = 1;
2787 if (cfg.compression) {
2788 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2792 if (pktin.type != SSH1_SMSG_SUCCESS
2793 && pktin.type != SSH1_SMSG_FAILURE) {
2794 bombout(("Protocol confusion"));
2796 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2797 c_write_str("Server refused to compress\r\n");
2799 logevent("Started compression");
2800 ssh1_compressing = TRUE;
2801 zlib_compress_init();
2802 zlib_decompress_init();
2806 * Start the shell or command.
2808 * Special case: if the first-choice command is an SSH2
2809 * subsystem (hence not usable here) and the second choice
2810 * exists, we fall straight back to that.
2813 char *cmd = cfg.remote_cmd_ptr;
2815 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2816 cmd = cfg.remote_cmd_ptr2;
2817 ssh_fallback_cmd = TRUE;
2820 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
2822 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
2823 logevent("Started session");
2826 ssh_state = SSH_STATE_SESSION;
2830 ssh_special(TS_EOF);
2832 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
2834 ssh_channels = newtree234(ssh_channelcmp);
2838 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
2839 pktin.type == SSH1_SMSG_STDERR_DATA) {
2840 long len = GET_32BIT(pktin.body);
2842 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
2843 pktin.body + 4, len);
2844 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
2845 ssh1_stdout_throttling = 1;
2848 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2849 ssh_state = SSH_STATE_CLOSED;
2850 logevent("Received disconnect request");
2852 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
2853 /* Remote side is trying to open a channel to talk to our
2854 * X-Server. Give them back a local channel number. */
2855 struct ssh_channel *c;
2857 logevent("Received X11 connect request");
2858 /* Refuse if X11 forwarding is disabled. */
2859 if (!ssh_X11_fwd_enabled) {
2860 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2861 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2862 logevent("Rejected X11 connect request");
2864 c = smalloc(sizeof(struct ssh_channel));
2866 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
2867 logevent("opening X11 forward connection failed");
2869 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2870 PKT_INT, GET_32BIT(pktin.body),
2874 ("opening X11 forward connection succeeded");
2875 c->remoteid = GET_32BIT(pktin.body);
2876 c->localid = alloc_channel_id();
2878 c->v.v1.throttling = 0;
2879 c->type = CHAN_X11; /* identify channel type */
2880 add234(ssh_channels, c);
2881 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2882 PKT_INT, c->remoteid, PKT_INT,
2883 c->localid, PKT_END);
2884 logevent("Opened X11 forward channel");
2887 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
2888 /* Remote side is trying to open a channel to talk to our
2889 * agent. Give them back a local channel number. */
2890 struct ssh_channel *c;
2892 /* Refuse if agent forwarding is disabled. */
2893 if (!ssh_agentfwd_enabled) {
2894 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2895 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2897 c = smalloc(sizeof(struct ssh_channel));
2898 c->remoteid = GET_32BIT(pktin.body);
2899 c->localid = alloc_channel_id();
2901 c->v.v1.throttling = 0;
2902 c->type = CHAN_AGENT; /* identify channel type */
2903 c->u.a.lensofar = 0;
2904 add234(ssh_channels, c);
2905 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2906 PKT_INT, c->remoteid, PKT_INT, c->localid,
2909 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
2910 /* Remote side is trying to open a channel to talk to a
2911 * forwarded port. Give them back a local channel number. */
2912 struct ssh_channel *c;
2913 struct ssh_rportfwd pf;
2915 char host[256], buf[1024];
2917 c = smalloc(sizeof(struct ssh_channel));
2919 hostsize = GET_32BIT(pktin.body+4);
2920 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
2921 if (h+1 < host+sizeof(host))
2926 port = GET_32BIT(p);
2928 strcpy(pf.dhost, host);
2931 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
2932 sprintf(buf, "Rejected remote port open request for %s:%d",
2935 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2936 PKT_INT, GET_32BIT(pktin.body), PKT_END);
2938 sprintf(buf, "Received remote port open request for %s:%d",
2941 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
2944 sprintf(buf, "Port open failed: %s", e);
2947 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
2948 PKT_INT, GET_32BIT(pktin.body),
2951 c->remoteid = GET_32BIT(pktin.body);
2952 c->localid = alloc_channel_id();
2954 c->v.v1.throttling = 0;
2955 c->type = CHAN_SOCKDATA; /* identify channel type */
2956 add234(ssh_channels, c);
2957 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
2958 PKT_INT, c->remoteid, PKT_INT,
2959 c->localid, PKT_END);
2960 logevent("Forwarded port opened successfully");
2964 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
2965 unsigned int remoteid = GET_32BIT(pktin.body);
2966 unsigned int localid = GET_32BIT(pktin.body+4);
2967 struct ssh_channel *c;
2969 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2970 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2971 c->remoteid = localid;
2972 c->type = CHAN_SOCKDATA;
2973 c->v.v1.throttling = 0;
2974 pfd_confirm(c->u.pfd.s);
2977 if (c && c->closes) {
2979 * We have a pending close on this channel,
2980 * which we decided on before the server acked
2981 * the channel open. So now we know the
2982 * remoteid, we can close it again.
2984 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2988 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
2989 unsigned int remoteid = GET_32BIT(pktin.body);
2990 unsigned int localid = GET_32BIT(pktin.body+4);
2991 struct ssh_channel *c;
2993 c = find234(ssh_channels, &remoteid, ssh_channelfind);
2994 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
2995 logevent("Forwarded connection refused by server");
2996 pfd_close(c->u.pfd.s);
2997 del234(ssh_channels, c);
3001 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3002 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3003 /* Remote side closes a channel. */
3004 unsigned i = GET_32BIT(pktin.body);
3005 struct ssh_channel *c;
3006 c = find234(ssh_channels, &i, ssh_channelfind);
3010 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3011 if (!(c->closes & closetype))
3012 send_packet(pktin.type, PKT_INT, c->remoteid,
3014 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3015 logevent("Forwarded X11 connection terminated");
3016 assert(c->u.x11.s != NULL);
3017 x11_close(c->u.x11.s);
3020 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3021 logevent("Forwarded port closed");
3022 assert(c->u.pfd.s != NULL);
3023 pfd_close(c->u.pfd.s);
3026 c->closes |= closetype;
3027 if (c->closes == 3) {
3028 del234(ssh_channels, c);
3032 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3033 /* Data sent down one of our channels. */
3034 int i = GET_32BIT(pktin.body);
3035 int len = GET_32BIT(pktin.body + 4);
3036 unsigned char *p = pktin.body + 8;
3037 struct ssh_channel *c;
3038 c = find234(ssh_channels, &i, ssh_channelfind);
3043 bufsize = x11_send(c->u.x11.s, p, len);
3046 bufsize = pfd_send(c->u.pfd.s, p, len);
3049 /* Data for an agent message. Buffer it. */
3051 if (c->u.a.lensofar < 4) {
3052 int l = min(4 - c->u.a.lensofar, len);
3053 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3057 c->u.a.lensofar += l;
3059 if (c->u.a.lensofar == 4) {
3061 4 + GET_32BIT(c->u.a.msglen);
3062 c->u.a.message = smalloc(c->u.a.totallen);
3063 memcpy(c->u.a.message, c->u.a.msglen, 4);
3065 if (c->u.a.lensofar >= 4 && len > 0) {
3067 min(c->u.a.totallen - c->u.a.lensofar,
3069 memcpy(c->u.a.message + c->u.a.lensofar, p,
3073 c->u.a.lensofar += l;
3075 if (c->u.a.lensofar == c->u.a.totallen) {
3076 void *reply, *sentreply;
3078 agent_query(c->u.a.message,
3079 c->u.a.totallen, &reply,
3084 /* Fake SSH_AGENT_FAILURE. */
3085 sentreply = "\0\0\0\1\5";
3088 send_packet(SSH1_MSG_CHANNEL_DATA,
3089 PKT_INT, c->remoteid,
3091 PKT_DATA, sentreply, replylen,
3095 sfree(c->u.a.message);
3096 c->u.a.lensofar = 0;
3099 bufsize = 0; /* agent channels never back up */
3102 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3103 c->v.v1.throttling = 1;
3107 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3108 /* may be from EXEC_SHELL on some servers */
3109 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3110 /* may be from EXEC_SHELL on some servers
3111 * if no pty is available or in other odd cases. Ignore */
3112 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3113 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3115 * In case `helpful' firewalls or proxies tack
3116 * extra human-readable text on the end of the
3117 * session which we might mistake for another
3118 * encrypted packet, we close the session once
3119 * we've sent EXIT_CONFIRMATION.
3121 ssh_state = SSH_STATE_CLOSED;
3124 bombout(("Strange packet received: type %d", pktin.type));
3129 int len = min(inlen, 512);
3130 send_packet(SSH1_CMSG_STDIN_DATA,
3131 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3142 * Utility routine for decoding comma-separated strings in KEXINIT.
3144 static int in_commasep_string(char *needle, char *haystack, int haylen)
3146 int needlen = strlen(needle);
3149 * Is it at the start of the string?
3151 if (haylen >= needlen && /* haystack is long enough */
3152 !memcmp(needle, haystack, needlen) && /* initial match */
3153 (haylen == needlen || haystack[needlen] == ',')
3154 /* either , or EOS follows */
3158 * If not, search for the next comma and resume after that.
3159 * If no comma found, terminate.
3161 while (haylen > 0 && *haystack != ',')
3162 haylen--, haystack++;
3165 haylen--, haystack++; /* skip over comma itself */
3170 * SSH2 key creation method.
3172 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3176 /* First 20 bytes. */
3179 SHA_Bytes(&s, H, 20);
3180 SHA_Bytes(&s, &chr, 1);
3181 SHA_Bytes(&s, sessid, 20);
3182 SHA_Final(&s, keyspace);
3183 /* Next 20 bytes. */
3186 SHA_Bytes(&s, H, 20);
3187 SHA_Bytes(&s, keyspace, 20);
3188 SHA_Final(&s, keyspace + 20);
3192 * Handle the SSH2 transport layer.
3194 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3196 static int i, j, len, nbits, pbits, warn;
3198 static Bignum p, g, e, f, K;
3199 static int kex_init_value, kex_reply_value;
3200 static const struct ssh_mac **maclist;
3202 static const struct ssh2_cipher *cscipher_tobe = NULL;
3203 static const struct ssh2_cipher *sccipher_tobe = NULL;
3204 static const struct ssh_mac *csmac_tobe = NULL;
3205 static const struct ssh_mac *scmac_tobe = NULL;
3206 static const struct ssh_compress *cscomp_tobe = NULL;
3207 static const struct ssh_compress *sccomp_tobe = NULL;
3208 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3209 static int hostkeylen, siglen;
3210 static void *hkey; /* actual host key */
3211 static unsigned char exchange_hash[20];
3212 static unsigned char keyspace[40];
3213 static int n_preferred_ciphers;
3214 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3215 static const struct ssh_compress *preferred_comp;
3216 static int cipherstr_started;
3217 static int first_kex;
3224 * Set up the preferred ciphers. (NULL => warn below here)
3226 n_preferred_ciphers = 0;
3227 for (i = 0; i < CIPHER_MAX; i++) {
3228 switch (cfg.ssh_cipherlist[i]) {
3229 case CIPHER_BLOWFISH:
3230 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3231 n_preferred_ciphers++;
3234 if (cfg.ssh2_des_cbc) {
3235 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3236 n_preferred_ciphers++;
3240 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3241 n_preferred_ciphers++;
3244 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3245 n_preferred_ciphers++;
3248 /* Flag for later. Don't bother if it's the last in
3250 if (i < CIPHER_MAX - 1) {
3251 preferred_ciphers[n_preferred_ciphers] = NULL;
3252 n_preferred_ciphers++;
3259 * Set up preferred compression.
3261 if (cfg.compression)
3262 preferred_comp = &ssh_zlib;
3264 preferred_comp = &ssh_comp_none;
3267 * Be prepared to work around the buggy MAC problem.
3269 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3270 maclist = buggymacs, nmacs = lenof(buggymacs);
3272 maclist = macs, nmacs = lenof(macs);
3276 * Construct and send our key exchange packet.
3278 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3279 for (i = 0; i < 16; i++)
3280 ssh2_pkt_addbyte((unsigned char) random_byte());
3281 /* List key exchange algorithms. */
3282 ssh2_pkt_addstring_start();
3283 for (i = 0; i < lenof(kex_algs); i++) {
3284 ssh2_pkt_addstring_str(kex_algs[i]->name);
3285 if (i < lenof(kex_algs) - 1)
3286 ssh2_pkt_addstring_str(",");
3288 /* List server host key algorithms. */
3289 ssh2_pkt_addstring_start();
3290 for (i = 0; i < lenof(hostkey_algs); i++) {
3291 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3292 if (i < lenof(hostkey_algs) - 1)
3293 ssh2_pkt_addstring_str(",");
3295 /* List client->server encryption algorithms. */
3296 ssh2_pkt_addstring_start();
3297 cipherstr_started = 0;
3298 for (i = 0; i < n_preferred_ciphers; i++) {
3299 const struct ssh2_ciphers *c = preferred_ciphers[i];
3300 if (!c) continue; /* warning flag */
3301 for (j = 0; j < c->nciphers; j++) {
3302 if (cipherstr_started)
3303 ssh2_pkt_addstring_str(",");
3304 ssh2_pkt_addstring_str(c->list[j]->name);
3305 cipherstr_started = 1;
3308 /* List server->client encryption algorithms. */
3309 ssh2_pkt_addstring_start();
3310 cipherstr_started = 0;
3311 for (i = 0; i < n_preferred_ciphers; i++) {
3312 const struct ssh2_ciphers *c = preferred_ciphers[i];
3313 if (!c) continue; /* warning flag */
3314 for (j = 0; j < c->nciphers; j++) {
3315 if (cipherstr_started)
3316 ssh2_pkt_addstring_str(",");
3317 ssh2_pkt_addstring_str(c->list[j]->name);
3318 cipherstr_started = 1;
3321 /* List client->server MAC algorithms. */
3322 ssh2_pkt_addstring_start();
3323 for (i = 0; i < nmacs; i++) {
3324 ssh2_pkt_addstring_str(maclist[i]->name);
3326 ssh2_pkt_addstring_str(",");
3328 /* List server->client MAC algorithms. */
3329 ssh2_pkt_addstring_start();
3330 for (i = 0; i < nmacs; i++) {
3331 ssh2_pkt_addstring_str(maclist[i]->name);
3333 ssh2_pkt_addstring_str(",");
3335 /* List client->server compression algorithms. */
3336 ssh2_pkt_addstring_start();
3337 for (i = 0; i < lenof(compressions) + 1; i++) {
3338 const struct ssh_compress *c =
3339 i == 0 ? preferred_comp : compressions[i - 1];
3340 ssh2_pkt_addstring_str(c->name);
3341 if (i < lenof(compressions))
3342 ssh2_pkt_addstring_str(",");
3344 /* List server->client compression algorithms. */
3345 ssh2_pkt_addstring_start();
3346 for (i = 0; i < lenof(compressions) + 1; i++) {
3347 const struct ssh_compress *c =
3348 i == 0 ? preferred_comp : compressions[i - 1];
3349 ssh2_pkt_addstring_str(c->name);
3350 if (i < lenof(compressions))
3351 ssh2_pkt_addstring_str(",");
3353 /* List client->server languages. Empty list. */
3354 ssh2_pkt_addstring_start();
3355 /* List server->client languages. Empty list. */
3356 ssh2_pkt_addstring_start();
3357 /* First KEX packet does _not_ follow, because we're not that brave. */
3358 ssh2_pkt_addbool(FALSE);
3360 ssh2_pkt_adduint32(0);
3362 exhash = exhashbase;
3363 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3369 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3372 * Now examine the other side's KEXINIT to see what we're up
3375 if (pktin.type != SSH2_MSG_KEXINIT) {
3376 bombout(("expected key exchange packet from server"));
3381 cscipher_tobe = NULL;
3382 sccipher_tobe = NULL;
3387 pktin.savedpos += 16; /* skip garbage cookie */
3388 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3389 for (i = 0; i < lenof(kex_algs); i++) {
3390 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3395 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3396 for (i = 0; i < lenof(hostkey_algs); i++) {
3397 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3398 hostkey = hostkey_algs[i];
3402 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3404 for (i = 0; i < n_preferred_ciphers; i++) {
3405 const struct ssh2_ciphers *c = preferred_ciphers[i];
3409 for (j = 0; j < c->nciphers; j++) {
3410 if (in_commasep_string(c->list[j]->name, str, len)) {
3411 cscipher_tobe = c->list[j];
3416 if (cscipher_tobe) {
3418 askcipher(cscipher_tobe->name, 1);
3422 if (!cscipher_tobe) {
3423 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3427 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3429 for (i = 0; i < n_preferred_ciphers; i++) {
3430 const struct ssh2_ciphers *c = preferred_ciphers[i];
3434 for (j = 0; j < c->nciphers; j++) {
3435 if (in_commasep_string(c->list[j]->name, str, len)) {
3436 sccipher_tobe = c->list[j];
3441 if (sccipher_tobe) {
3443 askcipher(sccipher_tobe->name, 2);
3447 if (!sccipher_tobe) {
3448 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3452 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3453 for (i = 0; i < nmacs; i++) {
3454 if (in_commasep_string(maclist[i]->name, str, len)) {
3455 csmac_tobe = maclist[i];
3459 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3460 for (i = 0; i < nmacs; i++) {
3461 if (in_commasep_string(maclist[i]->name, str, len)) {
3462 scmac_tobe = maclist[i];
3466 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3467 for (i = 0; i < lenof(compressions) + 1; i++) {
3468 const struct ssh_compress *c =
3469 i == 0 ? preferred_comp : compressions[i - 1];
3470 if (in_commasep_string(c->name, str, len)) {
3475 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3476 for (i = 0; i < lenof(compressions) + 1; i++) {
3477 const struct ssh_compress *c =
3478 i == 0 ? preferred_comp : compressions[i - 1];
3479 if (in_commasep_string(c->name, str, len)) {
3486 * Work out the number of bits of key we will need from the key
3487 * exchange. We start with the maximum key length of either
3493 csbits = cscipher_tobe->keylen;
3494 scbits = sccipher_tobe->keylen;
3495 nbits = (csbits > scbits ? csbits : scbits);
3497 /* The keys only have 160-bit entropy, since they're based on
3498 * a SHA-1 hash. So cap the key size at 160 bits. */
3503 * If we're doing Diffie-Hellman group exchange, start by
3504 * requesting a group.
3506 if (kex == &ssh_diffiehellman_gex) {
3507 logevent("Doing Diffie-Hellman group exchange");
3508 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
3510 * Work out how big a DH group we will need to allow that
3513 pbits = 512 << ((nbits - 1) / 64);
3514 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3515 ssh2_pkt_adduint32(pbits);
3519 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3520 bombout(("expected key exchange group packet from server"));
3523 p = ssh2_pkt_getmp();
3524 g = ssh2_pkt_getmp();
3525 dh_setup_group(p, g);
3526 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3527 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3529 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3531 kex_init_value = SSH2_MSG_KEXDH_INIT;
3532 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3535 logevent("Doing Diffie-Hellman key exchange");
3537 * Now generate and send e for Diffie-Hellman.
3539 e = dh_create_e(nbits * 2);
3540 ssh2_pkt_init(kex_init_value);
3545 if (pktin.type != kex_reply_value) {
3546 bombout(("expected key exchange reply packet from server"));
3549 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3550 f = ssh2_pkt_getmp();
3551 ssh2_pkt_getstring(&sigdata, &siglen);
3555 sha_string(&exhash, hostkeydata, hostkeylen);
3556 if (kex == &ssh_diffiehellman_gex) {
3557 sha_uint32(&exhash, pbits);
3558 sha_mpint(&exhash, p);
3559 sha_mpint(&exhash, g);
3561 sha_mpint(&exhash, e);
3562 sha_mpint(&exhash, f);
3563 sha_mpint(&exhash, K);
3564 SHA_Final(&exhash, exchange_hash);
3569 debug(("Exchange hash is:\n"));
3570 dmemdump(exchange_hash, 20);
3573 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3575 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3576 bombout(("Server's host key did not match the signature supplied"));
3581 * Authenticate remote host: verify host key. (We've already
3582 * checked the signature of the exchange hash.)
3584 keystr = hostkey->fmtkey(hkey);
3585 fingerprint = hostkey->fingerprint(hkey);
3586 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3587 keystr, fingerprint);
3588 if (first_kex) { /* don't bother logging this in rekeys */
3589 logevent("Host key fingerprint is:");
3590 logevent(fingerprint);
3594 hostkey->freekey(hkey);
3597 * Send SSH2_MSG_NEWKEYS.
3599 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3603 * Expect SSH2_MSG_NEWKEYS from server.
3606 if (pktin.type != SSH2_MSG_NEWKEYS) {
3607 bombout(("expected new-keys packet from server"));
3612 * Create and initialise session keys.
3614 cscipher = cscipher_tobe;
3615 sccipher = sccipher_tobe;
3618 cscomp = cscomp_tobe;
3619 sccomp = sccomp_tobe;
3620 cscomp->compress_init();
3621 sccomp->decompress_init();
3623 * Set IVs after keys. Here we use the exchange hash from the
3624 * _first_ key exchange.
3627 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3628 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3629 cscipher->setcskey(keyspace);
3630 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3631 sccipher->setsckey(keyspace);
3632 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3633 cscipher->setcsiv(keyspace);
3634 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3635 sccipher->setsciv(keyspace);
3636 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3637 csmac->setcskey(keyspace);
3638 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3639 scmac->setsckey(keyspace);
3642 * If this is the first key exchange phase, we must pass the
3643 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3644 * wants to see it but because it will need time to initialise
3645 * itself before it sees an actual packet. In subsequent key
3646 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3647 * it would only confuse the layer above.
3655 * Now we're encrypting. Begin returning 1 to the protocol main
3656 * function so that other things can run on top of the
3657 * transport. If we ever see a KEXINIT, we must go back to the
3660 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3663 logevent("Server initiated key re-exchange");
3664 goto begin_key_exchange;
3670 * Add data to an SSH2 channel output buffer.
3672 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3675 bufchain_add(&c->v.v2.outbuffer, buf, len);
3679 * Attempt to send data on an SSH2 channel.
3681 static int ssh2_try_send(struct ssh_channel *c)
3683 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3686 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3687 if ((unsigned)len > c->v.v2.remwindow)
3688 len = c->v.v2.remwindow;
3689 if ((unsigned)len > c->v.v2.remmaxpkt)
3690 len = c->v.v2.remmaxpkt;
3691 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3692 ssh2_pkt_adduint32(c->remoteid);
3693 ssh2_pkt_addstring_start();
3694 ssh2_pkt_addstring_data(data, len);
3696 bufchain_consume(&c->v.v2.outbuffer, len);
3697 c->v.v2.remwindow -= len;
3701 * After having sent as much data as we can, return the amount
3704 return bufchain_size(&c->v.v2.outbuffer);
3708 * Potentially enlarge the window on an SSH2 channel.
3710 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3712 if (newwin > c->v.v2.locwindow) {
3713 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3714 ssh2_pkt_adduint32(c->remoteid);
3715 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3717 c->v.v2.locwindow = newwin;
3722 * Handle the SSH2 userauth and connection layers.
3724 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3727 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3729 AUTH_KEYBOARD_INTERACTIVE
3733 AUTH_TYPE_PUBLICKEY,
3734 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3735 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3737 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3738 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3740 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3741 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
3742 static int kbd_inter_running;
3743 static int we_are_in;
3744 static int num_prompts, echo;
3745 static char username[100];
3746 static char pwprompt[200];
3747 static char password[100];
3752 * Request userauth protocol, and await a response to it.
3754 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3755 ssh2_pkt_addstring("ssh-userauth");
3757 crWaitUntilV(ispkt);
3758 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3759 bombout(("Server refused user authentication protocol"));
3764 * We repeat this whole loop, including the username prompt,
3765 * until we manage a successful authentication. If the user
3766 * types the wrong _password_, they are sent back to the
3767 * beginning to try another username. (If they specify a
3768 * username in the config, they are never asked, even if they
3769 * do give a wrong password.)
3771 * I think this best serves the needs of
3773 * - the people who have no configuration, no keys, and just
3774 * want to try repeated (username,password) pairs until they
3775 * type both correctly
3777 * - people who have keys and configuration but occasionally
3778 * need to fall back to passwords
3780 * - people with a key held in Pageant, who might not have
3781 * logged in to a particular machine before; so they want to
3782 * type a username, and then _either_ their key will be
3783 * accepted, _or_ they will type a password. If they mistype
3784 * the username they will want to be able to get back and
3796 if (*username && !cfg.change_username) {
3798 * We got a username last time round this loop, and
3799 * with change_username turned off we don't try to get
3802 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
3804 if (!ssh_get_line("login as: ",
3805 username, sizeof(username), FALSE)) {
3807 * get_line failed to get a username.
3810 logevent("No username provided. Abandoning session.");
3811 ssh_state = SSH_STATE_CLOSED;
3815 c_write_str("login as: ");
3818 crWaitUntilV(!ispkt);
3820 switch (c = *in++) {
3829 c_write_str("\b \b");
3836 c_write_str("\b \b");
3846 if (((c >= ' ' && c <= '~') ||
3847 ((unsigned char) c >= 160))
3848 && pos < sizeof(username)-1) {
3849 username[pos++] = c;
3856 c_write_str("\r\n");
3857 username[strcspn(username, "\n\r")] = '\0';
3860 strncpy(username, cfg.username, 99);
3861 username[99] = '\0';
3862 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
3863 sprintf(stuff, "Using username \"%s\".\r\n", username);
3869 * Send an authentication request using method "none": (a)
3870 * just in case it succeeds, and (b) so that we know what
3871 * authentication methods we can usefully try next.
3873 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
3875 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
3876 ssh2_pkt_addstring(username);
3877 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3878 ssh2_pkt_addstring("none"); /* method */
3880 type = AUTH_TYPE_NONE;
3884 tried_pubkey_config = FALSE;
3885 tried_agent = FALSE;
3886 tried_keyb_inter = FALSE;
3887 kbd_inter_running = FALSE;
3891 * Wait for the result of the last authentication request.
3894 crWaitUntilV(ispkt);
3895 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
3899 * Don't show the banner if we're operating in
3900 * non-verbose non-interactive mode. (It's probably
3901 * a script, which means nobody will read the
3902 * banner _anyway_, and moreover the printing of
3903 * the banner will screw up processing on the
3904 * output of (say) plink.)
3906 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
3907 ssh2_pkt_getstring(&banner, &size);
3909 c_write_untrusted(banner, size);
3911 crWaitUntilV(ispkt);
3913 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
3914 logevent("Access granted");
3919 if (kbd_inter_running &&
3920 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
3922 * This is a further prompt in keyboard-interactive
3923 * authentication. Do nothing.
3925 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
3926 bombout(("Strange packet received during authentication: type %d",
3934 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3935 * we can look at the string in it and know what we can
3936 * helpfully try next.
3938 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
3941 ssh2_pkt_getstring(&methods, &methlen);
3942 kbd_inter_running = FALSE;
3943 if (!ssh2_pkt_getbool()) {
3945 * We have received an unequivocal Access
3946 * Denied. This can translate to a variety of
3949 * - if we'd just tried "none" authentication,
3950 * it's not worth printing anything at all
3952 * - if we'd just tried a public key _offer_,
3953 * the message should be "Server refused our
3954 * key" (or no message at all if the key
3955 * came from Pageant)
3957 * - if we'd just tried anything else, the
3958 * message really should be "Access denied".
3960 * Additionally, if we'd just tried password
3961 * authentication, we should break out of this
3962 * whole loop so as to go back to the username
3965 if (type == AUTH_TYPE_NONE) {
3967 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
3968 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
3969 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
3970 c_write_str("Server refused our key\r\n");
3971 logevent("Server refused public key");
3972 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
3973 /* server declined keyboard-interactive; ignore */
3975 c_write_str("Access denied\r\n");
3976 logevent("Access denied");
3977 if (type == AUTH_TYPE_PASSWORD) {
3983 c_write_str("Further authentication required\r\n");
3984 logevent("Further authentication required");
3988 in_commasep_string("publickey", methods, methlen);
3990 in_commasep_string("password", methods, methlen);
3991 can_keyb_inter = cfg.try_ki_auth &&
3992 in_commasep_string("keyboard-interactive", methods, methlen);
3996 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
3998 if (!method && can_pubkey && agent_exists() && !tried_agent) {
4000 * Attempt public-key authentication using Pageant.
4002 static unsigned char request[5], *response, *p;
4003 static int responselen;
4004 static int i, nkeys;
4005 static int authed = FALSE;
4008 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4012 logevent("Pageant is running. Requesting keys.");
4014 /* Request the keys held by the agent. */
4015 PUT_32BIT(request, 1);
4016 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4017 agent_query(request, 5, &r, &responselen);
4018 response = (unsigned char *) r;
4019 if (response && responselen >= 5 &&
4020 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4022 nkeys = GET_32BIT(p);
4026 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4029 for (i = 0; i < nkeys; i++) {
4030 static char *pkblob, *alg, *commentp;
4031 static int pklen, alglen, commentlen;
4032 static int siglen, retlen, len;
4033 static char *q, *agentreq, *ret;
4038 sprintf(buf, "Trying Pageant key #%d", i);
4041 pklen = GET_32BIT(p);
4045 alglen = GET_32BIT(pkblob);
4047 commentlen = GET_32BIT(p);
4051 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4052 ssh2_pkt_addstring(username);
4053 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4054 ssh2_pkt_addstring("publickey"); /* method */
4055 ssh2_pkt_addbool(FALSE); /* no signature included */
4056 ssh2_pkt_addstring_start();
4057 ssh2_pkt_addstring_data(alg, alglen);
4058 ssh2_pkt_addstring_start();
4059 ssh2_pkt_addstring_data(pkblob, pklen);
4062 crWaitUntilV(ispkt);
4063 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4064 logevent("Key refused");
4068 if (flags & FLAG_VERBOSE) {
4070 ("Authenticating with public key \"");
4071 c_write(commentp, commentlen);
4072 c_write_str("\" from agent\r\n");
4076 * Server is willing to accept the key.
4077 * Construct a SIGN_REQUEST.
4079 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4080 ssh2_pkt_addstring(username);
4081 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4082 ssh2_pkt_addstring("publickey"); /* method */
4083 ssh2_pkt_addbool(TRUE);
4084 ssh2_pkt_addstring_start();
4085 ssh2_pkt_addstring_data(alg, alglen);
4086 ssh2_pkt_addstring_start();
4087 ssh2_pkt_addstring_data(pkblob, pklen);
4089 siglen = pktout.length - 5 + 4 + 20;
4090 len = 1; /* message type */
4091 len += 4 + pklen; /* key blob */
4092 len += 4 + siglen; /* data to sign */
4093 len += 4; /* flags */
4094 agentreq = smalloc(4 + len);
4095 PUT_32BIT(agentreq, len);
4097 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4098 PUT_32BIT(q, pklen);
4100 memcpy(q, pkblob, pklen);
4102 PUT_32BIT(q, siglen);
4104 /* Now the data to be signed... */
4107 memcpy(q, ssh2_session_id, 20);
4109 memcpy(q, pktout.data + 5, pktout.length - 5);
4110 q += pktout.length - 5;
4111 /* And finally the (zero) flags word. */
4113 agent_query(agentreq, len + 4, &vret, &retlen);
4117 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4118 logevent("Sending Pageant's response");
4119 ssh2_pkt_addstring_start();
4120 ssh2_pkt_addstring_data(ret + 9,
4128 ("Pageant failed to answer challenge");
4138 if (!method && can_pubkey && *cfg.keyfile
4139 && !tried_pubkey_config) {
4140 unsigned char *pub_blob;
4141 char *algorithm, *comment;
4144 tried_pubkey_config = TRUE;
4146 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4149 * Try the public key supplied in the configuration.
4151 * First, offer the public blob to see if the server is
4152 * willing to accept it.
4154 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4157 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4158 ssh2_pkt_addstring(username);
4159 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4160 ssh2_pkt_addstring("publickey"); /* method */
4161 ssh2_pkt_addbool(FALSE); /* no signature included */
4162 ssh2_pkt_addstring(algorithm);
4163 ssh2_pkt_addstring_start();
4164 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4166 logevent("Offered public key"); /* FIXME */
4168 crWaitUntilV(ispkt);
4169 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4171 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4172 continue; /* key refused; give up on it */
4175 logevent("Offer of public key accepted");
4177 * Actually attempt a serious authentication using
4180 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4182 "Passphrase for key \"%.100s\": ",
4188 c_write_str("Authenticating with public key \"");
4189 c_write_str(comment);
4190 c_write_str("\"\r\n");
4191 method = AUTH_PUBLICKEY_FILE;
4195 if (!method && can_keyb_inter && !tried_keyb_inter) {
4196 method = AUTH_KEYBOARD_INTERACTIVE;
4197 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4198 tried_keyb_inter = TRUE;
4200 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4202 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4203 ssh2_pkt_addstring(username);
4204 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4205 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4206 ssh2_pkt_addstring(""); /* lang */
4207 ssh2_pkt_addstring("");
4210 crWaitUntilV(ispkt);
4211 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4212 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4214 logevent("Keyboard-interactive authentication refused");
4215 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4219 kbd_inter_running = TRUE;
4222 if (kbd_inter_running) {
4223 method = AUTH_KEYBOARD_INTERACTIVE;
4224 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4225 tried_keyb_inter = TRUE;
4227 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4229 /* We've got packet with that "interactive" info
4230 dump banners, and set its prompt as ours */
4232 char *name, *inst, *lang, *prompt;
4233 int name_len, inst_len, lang_len, prompt_len;
4234 ssh2_pkt_getstring(&name, &name_len);
4235 ssh2_pkt_getstring(&inst, &inst_len);
4236 ssh2_pkt_getstring(&lang, &lang_len);
4238 c_write_untrusted(name, name_len);
4240 c_write_untrusted(inst, inst_len);
4241 num_prompts = ssh2_pkt_getuint32();
4243 ssh2_pkt_getstring(&prompt, &prompt_len);
4244 strncpy(pwprompt, prompt, sizeof(pwprompt));
4245 pwprompt[prompt_len < sizeof(pwprompt) ?
4246 prompt_len : sizeof(pwprompt)-1] = '\0';
4249 echo = ssh2_pkt_getbool();
4253 if (!method && can_passwd) {
4254 method = AUTH_PASSWORD;
4255 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4256 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4263 if (!ssh_get_line(pwprompt, password,
4264 sizeof(password), TRUE)) {
4266 * get_line failed to get a password (for
4267 * example because one was supplied on the
4268 * command line which has already failed to
4271 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4272 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4274 ("No more passwords available to try");
4275 ssh2_pkt_addstring("en"); /* language tag */
4277 connection_fatal("Unable to authenticate");
4278 ssh_state = SSH_STATE_CLOSED;
4285 c_write_untrusted(pwprompt, strlen(pwprompt));
4290 crWaitUntilV(!ispkt);
4292 switch (c = *in++) {
4313 if (pos < sizeof(password)-1)
4314 password[pos++] = c;
4318 c_write_str("\r\n");
4322 if (method == AUTH_PUBLICKEY_FILE) {
4324 * We have our passphrase. Now try the actual authentication.
4326 struct ssh2_userkey *key;
4328 key = ssh2_load_userkey(cfg.keyfile, password);
4329 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4330 if (key == SSH2_WRONG_PASSPHRASE) {
4331 c_write_str("Wrong passphrase\r\n");
4332 tried_pubkey_config = FALSE;
4334 c_write_str("Unable to load private key\r\n");
4335 tried_pubkey_config = TRUE;
4337 /* Send a spurious AUTH_NONE to return to the top. */
4338 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4339 ssh2_pkt_addstring(username);
4340 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4341 ssh2_pkt_addstring("none"); /* method */
4343 type = AUTH_TYPE_NONE;
4345 unsigned char *blob, *sigdata;
4346 int blob_len, sigdata_len;
4349 * We have loaded the private key and the server
4350 * has announced that it's willing to accept it.
4351 * Hallelujah. Generate a signature and send it.
4353 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4354 ssh2_pkt_addstring(username);
4355 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4356 ssh2_pkt_addstring("publickey"); /* method */
4357 ssh2_pkt_addbool(TRUE);
4358 ssh2_pkt_addstring(key->alg->name);
4359 blob = key->alg->public_blob(key->data, &blob_len);
4360 ssh2_pkt_addstring_start();
4361 ssh2_pkt_addstring_data(blob, blob_len);
4365 * The data to be signed is:
4369 * followed by everything so far placed in the
4372 sigdata_len = pktout.length - 5 + 4 + 20;
4373 sigdata = smalloc(sigdata_len);
4374 PUT_32BIT(sigdata, 20);
4375 memcpy(sigdata + 4, ssh2_session_id, 20);
4376 memcpy(sigdata + 24, pktout.data + 5,
4379 key->alg->sign(key->data, sigdata, sigdata_len,
4381 ssh2_pkt_addstring_start();
4382 ssh2_pkt_addstring_data(blob, blob_len);
4387 type = AUTH_TYPE_PUBLICKEY;
4389 } else if (method == AUTH_PASSWORD) {
4391 * We send the password packet lumped tightly together with
4392 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4393 * string long enough to make the total length of the two
4394 * packets constant. This should ensure that a passive
4395 * listener doing traffic analyis can't work out the length
4398 * For this to work, we need an assumption about the
4399 * maximum length of the password packet. I think 256 is
4400 * pretty conservative. Anyone using a password longer than
4401 * that probably doesn't have much to worry about from
4402 * people who find out how long their password is!
4404 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4405 ssh2_pkt_addstring(username);
4406 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4407 ssh2_pkt_addstring("password");
4408 ssh2_pkt_addbool(FALSE);
4409 ssh2_pkt_addstring(password);
4412 * We'll include a string that's an exact multiple of the
4413 * cipher block size. If the cipher is NULL for some
4414 * reason, we don't do this trick at all because we gain
4420 stringlen = (256 - deferred_len);
4421 stringlen += cscipher->blksize - 1;
4422 stringlen -= (stringlen % cscipher->blksize);
4425 * Temporarily disable actual compression,
4426 * so we can guarantee to get this string
4427 * exactly the length we want it. The
4428 * compression-disabling routine should
4429 * return an integer indicating how many
4430 * bytes we should adjust our string length
4433 stringlen -= cscomp->disable_compression();
4435 ssh2_pkt_init(SSH2_MSG_IGNORE);
4436 ssh2_pkt_addstring_start();
4437 for (i = 0; i < stringlen; i++) {
4438 char c = (char) random_byte();
4439 ssh2_pkt_addstring_data(&c, 1);
4443 ssh_pkt_defersend();
4444 logevent("Sent password");
4445 type = AUTH_TYPE_PASSWORD;
4446 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4447 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4448 ssh2_pkt_adduint32(num_prompts);
4449 ssh2_pkt_addstring(password);
4450 memset(password, 0, sizeof(password));
4452 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4455 ("No supported authentication methods left to try!\r\n");
4457 ("No supported authentications offered. Disconnecting");
4458 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4459 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4461 ("No supported authentication methods available");
4462 ssh2_pkt_addstring("en"); /* language tag */
4464 ssh_state = SSH_STATE_CLOSED;
4468 } while (!we_are_in);
4471 * Now we're authenticated for the connection protocol. The
4472 * connection protocol will automatically have started at this
4473 * point; there's no need to send SERVICE_REQUEST.
4477 * So now create a channel with a session in it.
4479 ssh_channels = newtree234(ssh_channelcmp);
4480 mainchan = smalloc(sizeof(struct ssh_channel));
4481 mainchan->localid = alloc_channel_id();
4482 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4483 ssh2_pkt_addstring("session");
4484 ssh2_pkt_adduint32(mainchan->localid);
4485 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4486 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4487 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4489 crWaitUntilV(ispkt);
4490 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4491 bombout(("Server refused to open a session"));
4493 /* FIXME: error data comes back in FAILURE packet */
4495 if (ssh2_pkt_getuint32() != mainchan->localid) {
4496 bombout(("Server's channel confirmation cited wrong channel"));
4499 mainchan->remoteid = ssh2_pkt_getuint32();
4500 mainchan->type = CHAN_MAINSESSION;
4501 mainchan->closes = 0;
4502 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4503 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4504 bufchain_init(&mainchan->v.v2.outbuffer);
4505 add234(ssh_channels, mainchan);
4506 logevent("Opened channel for session");
4509 * Potentially enable X11 forwarding.
4511 if (cfg.x11_forward) {
4512 char proto[20], data[64];
4513 logevent("Requesting X11 forwarding");
4514 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4515 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4516 ssh2_pkt_adduint32(mainchan->remoteid);
4517 ssh2_pkt_addstring("x11-req");
4518 ssh2_pkt_addbool(1); /* want reply */
4519 ssh2_pkt_addbool(0); /* many connections */
4520 ssh2_pkt_addstring(proto);
4521 ssh2_pkt_addstring(data);
4522 ssh2_pkt_adduint32(0); /* screen number */
4526 crWaitUntilV(ispkt);
4527 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4528 unsigned i = ssh2_pkt_getuint32();
4529 struct ssh_channel *c;
4530 c = find234(ssh_channels, &i, ssh_channelfind);
4532 continue; /* nonexistent channel */
4533 c->v.v2.remwindow += ssh2_pkt_getuint32();
4535 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4537 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4538 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4539 bombout(("Unexpected response to X11 forwarding request:"
4540 " packet type %d", pktin.type));
4543 logevent("X11 forwarding refused");
4545 logevent("X11 forwarding enabled");
4546 ssh_X11_fwd_enabled = TRUE;
4551 * Enable port forwardings.
4554 static char *e; /* preserve across crReturn */
4558 char sports[256], dports[256], host[256];
4561 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4562 /* Add port forwardings. */
4567 while (*e && *e != '\t')
4573 while (*e && *e != ':')
4583 dport = atoi(dports);
4584 sport = atoi(sports);
4585 if (sport && dport) {
4587 pfd_addforward(host, dport, sport);
4588 sprintf(buf, "Local port %d forwarding to %s:%d",
4589 sport, host, dport);
4592 struct ssh_rportfwd *pf;
4593 pf = smalloc(sizeof(*pf));
4594 strcpy(pf->dhost, host);
4597 if (add234(ssh_rportfwds, pf) != pf) {
4599 "Duplicate remote port forwarding to %s:%d",
4604 sprintf(buf, "Requesting remote port %d (forwarded to %s:%d)",
4605 sport, host, dport);
4607 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4608 ssh2_pkt_addstring("tcpip-forward");
4609 ssh2_pkt_addbool(1);/* want reply */
4610 ssh2_pkt_addstring("127.0.0.1");
4611 ssh2_pkt_adduint32(sport);
4615 crWaitUntilV(ispkt);
4616 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4617 unsigned i = ssh2_pkt_getuint32();
4618 struct ssh_channel *c;
4619 c = find234(ssh_channels, &i, ssh_channelfind);
4621 continue;/* nonexistent channel */
4622 c->v.v2.remwindow += ssh2_pkt_getuint32();
4624 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4626 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4627 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4628 bombout(("Unexpected response to port "
4629 "forwarding request: packet type %d",
4633 logevent("Server refused this port forwarding");
4635 logevent("Remote port forwarding enabled");
4644 * Potentially enable agent forwarding.
4646 if (cfg.agentfwd && agent_exists()) {
4647 logevent("Requesting OpenSSH-style agent forwarding");
4648 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4649 ssh2_pkt_adduint32(mainchan->remoteid);
4650 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4651 ssh2_pkt_addbool(1); /* want reply */
4655 crWaitUntilV(ispkt);
4656 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4657 unsigned i = ssh2_pkt_getuint32();
4658 struct ssh_channel *c;
4659 c = find234(ssh_channels, &i, ssh_channelfind);
4661 continue; /* nonexistent channel */
4662 c->v.v2.remwindow += ssh2_pkt_getuint32();
4664 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4666 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4667 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4668 bombout(("Unexpected response to agent forwarding request:"
4669 " packet type %d", pktin.type));
4672 logevent("Agent forwarding refused");
4674 logevent("Agent forwarding enabled");
4675 ssh_agentfwd_enabled = TRUE;
4680 * Now allocate a pty for the session.
4683 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4684 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4685 ssh2_pkt_addstring("pty-req");
4686 ssh2_pkt_addbool(1); /* want reply */
4687 ssh2_pkt_addstring(cfg.termtype);
4688 ssh2_pkt_adduint32(cols);
4689 ssh2_pkt_adduint32(rows);
4690 ssh2_pkt_adduint32(0); /* pixel width */
4691 ssh2_pkt_adduint32(0); /* pixel height */
4692 ssh2_pkt_addstring_start();
4693 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4695 ssh_state = SSH_STATE_INTERMED;
4698 crWaitUntilV(ispkt);
4699 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4700 unsigned i = ssh2_pkt_getuint32();
4701 struct ssh_channel *c;
4702 c = find234(ssh_channels, &i, ssh_channelfind);
4704 continue; /* nonexistent channel */
4705 c->v.v2.remwindow += ssh2_pkt_getuint32();
4707 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4709 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4710 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4711 bombout(("Unexpected response to pty request:"
4712 " packet type %d", pktin.type));
4715 c_write_str("Server refused to allocate pty\r\n");
4716 ssh_editing = ssh_echoing = 1;
4718 logevent("Allocated pty");
4721 ssh_editing = ssh_echoing = 1;
4725 * Start a shell or a remote command. We may have to attempt
4726 * this twice if the config data has provided a second choice
4733 if (ssh_fallback_cmd) {
4734 subsys = cfg.ssh_subsys2;
4735 cmd = cfg.remote_cmd_ptr2;
4737 subsys = cfg.ssh_subsys;
4738 cmd = cfg.remote_cmd_ptr;
4741 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4742 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4744 ssh2_pkt_addstring("subsystem");
4745 ssh2_pkt_addbool(1); /* want reply */
4746 ssh2_pkt_addstring(cmd);
4748 ssh2_pkt_addstring("exec");
4749 ssh2_pkt_addbool(1); /* want reply */
4750 ssh2_pkt_addstring(cmd);
4752 ssh2_pkt_addstring("shell");
4753 ssh2_pkt_addbool(1); /* want reply */
4757 crWaitUntilV(ispkt);
4758 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4759 unsigned i = ssh2_pkt_getuint32();
4760 struct ssh_channel *c;
4761 c = find234(ssh_channels, &i, ssh_channelfind);
4763 continue; /* nonexistent channel */
4764 c->v.v2.remwindow += ssh2_pkt_getuint32();
4766 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4767 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4768 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4769 bombout(("Unexpected response to shell/command request:"
4770 " packet type %d", pktin.type));
4774 * We failed to start the command. If this is the
4775 * fallback command, we really are finished; if it's
4776 * not, and if the fallback command exists, try falling
4777 * back to it before complaining.
4779 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
4780 logevent("Primary command failed; attempting fallback");
4781 ssh_fallback_cmd = TRUE;
4784 bombout(("Server refused to start a shell/command"));
4787 logevent("Started a shell/command");
4792 ssh_state = SSH_STATE_SESSION;
4796 ssh_special(TS_EOF);
4801 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
4804 static int try_send;
4808 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
4809 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
4812 unsigned i = ssh2_pkt_getuint32();
4813 struct ssh_channel *c;
4814 c = find234(ssh_channels, &i, ssh_channelfind);
4816 continue; /* nonexistent channel */
4817 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
4818 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
4819 continue; /* extended but not stderr */
4820 ssh2_pkt_getstring(&data, &length);
4823 c->v.v2.locwindow -= length;
4825 case CHAN_MAINSESSION:
4827 from_backend(pktin.type ==
4828 SSH2_MSG_CHANNEL_EXTENDED_DATA,
4832 bufsize = x11_send(c->u.x11.s, data, length);
4835 bufsize = pfd_send(c->u.pfd.s, data, length);
4838 while (length > 0) {
4839 if (c->u.a.lensofar < 4) {
4840 int l = min(4 - c->u.a.lensofar, length);
4841 memcpy(c->u.a.msglen + c->u.a.lensofar,
4845 c->u.a.lensofar += l;
4847 if (c->u.a.lensofar == 4) {
4849 4 + GET_32BIT(c->u.a.msglen);
4850 c->u.a.message = smalloc(c->u.a.totallen);
4851 memcpy(c->u.a.message, c->u.a.msglen, 4);
4853 if (c->u.a.lensofar >= 4 && length > 0) {
4855 min(c->u.a.totallen - c->u.a.lensofar,
4857 memcpy(c->u.a.message + c->u.a.lensofar,
4861 c->u.a.lensofar += l;
4863 if (c->u.a.lensofar == c->u.a.totallen) {
4864 void *reply, *sentreply;
4866 agent_query(c->u.a.message,
4867 c->u.a.totallen, &reply,
4872 /* Fake SSH_AGENT_FAILURE. */
4873 sentreply = "\0\0\0\1\5";
4876 ssh2_add_channel_data(c, sentreply,
4881 sfree(c->u.a.message);
4882 c->u.a.lensofar = 0;
4889 * If we are not buffering too much data,
4890 * enlarge the window again at the remote side.
4892 if (bufsize < OUR_V2_WINSIZE)
4893 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
4895 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
4896 ssh_state = SSH_STATE_CLOSED;
4897 logevent("Received disconnect message");
4899 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
4900 unsigned i = ssh2_pkt_getuint32();
4901 struct ssh_channel *c;
4903 c = find234(ssh_channels, &i, ssh_channelfind);
4905 continue; /* nonexistent channel */
4907 if (c->type == CHAN_X11) {
4909 * Remote EOF on an X11 channel means we should
4910 * wrap up and close the channel ourselves.
4912 x11_close(c->u.x11.s);
4914 } else if (c->type == CHAN_AGENT) {
4916 } else if (c->type == CHAN_SOCKDATA) {
4917 pfd_close(c->u.pfd.s);
4920 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
4921 unsigned i = ssh2_pkt_getuint32();
4922 struct ssh_channel *c;
4924 c = find234(ssh_channels, &i, ssh_channelfind);
4926 continue; /* nonexistent channel */
4927 /* Do pre-close processing on the channel. */
4929 case CHAN_MAINSESSION:
4930 break; /* nothing to see here, move along */
4932 if (c->u.x11.s != NULL)
4933 x11_close(c->u.x11.s);
4940 if (c->u.pfd.s != NULL)
4941 pfd_close(c->u.pfd.s);
4945 if (c->closes == 0) {
4946 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
4947 ssh2_pkt_adduint32(c->remoteid);
4950 del234(ssh_channels, c);
4951 bufchain_clear(&c->v.v2.outbuffer);
4955 * See if that was the last channel left open.
4957 if (count234(ssh_channels) == 0) {
4960 * We used to send SSH_MSG_DISCONNECT here,
4961 * because I'd believed that _every_ conforming
4962 * SSH2 connection had to end with a disconnect
4963 * being sent by at least one side; apparently
4964 * I was wrong and it's perfectly OK to
4965 * unceremoniously slam the connection shut
4966 * when you're done, and indeed OpenSSH feels
4967 * this is more polite than sending a
4968 * DISCONNECT. So now we don't.
4970 logevent("All channels closed. Disconnecting");
4971 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4972 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4973 ssh2_pkt_addstring("All open channels closed");
4974 ssh2_pkt_addstring("en"); /* language tag */
4977 ssh_state = SSH_STATE_CLOSED;
4980 continue; /* remote sends close; ignore (FIXME) */
4981 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4982 unsigned i = ssh2_pkt_getuint32();
4983 struct ssh_channel *c;
4984 c = find234(ssh_channels, &i, ssh_channelfind);
4986 continue; /* nonexistent channel */
4987 c->v.v2.remwindow += ssh2_pkt_getuint32();
4989 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4990 unsigned i = ssh2_pkt_getuint32();
4991 struct ssh_channel *c;
4992 c = find234(ssh_channels, &i, ssh_channelfind);
4994 continue; /* nonexistent channel */
4995 if (c->type != CHAN_SOCKDATA_DORMANT)
4996 continue; /* dunno why they're confirming this */
4997 c->remoteid = ssh2_pkt_getuint32();
4998 c->type = CHAN_SOCKDATA;
4999 c->v.v2.remwindow = ssh2_pkt_getuint32();
5000 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5001 bufchain_init(&c->v.v2.outbuffer);
5003 pfd_confirm(c->u.pfd.s);
5006 * We have a pending close on this channel,
5007 * which we decided on before the server acked
5008 * the channel open. So now we know the
5009 * remoteid, we can close it again.
5011 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5012 ssh2_pkt_adduint32(c->remoteid);
5015 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5016 unsigned i = ssh2_pkt_getuint32();
5017 struct ssh_channel *c;
5018 c = find234(ssh_channels, &i, ssh_channelfind);
5020 continue; /* nonexistent channel */
5021 if (c->type != CHAN_SOCKDATA_DORMANT)
5022 continue; /* dunno why they're failing this */
5024 logevent("Forwarded connection refused by server");
5026 pfd_close(c->u.pfd.s);
5028 del234(ssh_channels, c);
5030 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5033 int typelen, want_reply;
5034 struct ssh_channel *c;
5036 localid = ssh2_pkt_getuint32();
5037 ssh2_pkt_getstring(&type, &typelen);
5038 want_reply = ssh2_pkt_getbool();
5041 * First, check that the channel exists. Otherwise,
5042 * we can instantly disconnect with a rude message.
5044 c = find234(ssh_channels, &localid, ssh_channelfind);
5047 sprintf(buf, "Received channel request for nonexistent"
5048 " channel %d", localid);
5050 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5051 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5052 ssh2_pkt_addstring(buf);
5053 ssh2_pkt_addstring("en"); /* language tag */
5055 connection_fatal(buf);
5056 ssh_state = SSH_STATE_CLOSED;
5061 * We don't recognise any form of channel request,
5062 * so we now either ignore the request or respond
5063 * with CHANNEL_FAILURE, depending on want_reply.
5066 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5067 ssh2_pkt_adduint32(c->remoteid);
5070 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5074 struct ssh_channel *c;
5075 unsigned remid, winsize, pktsize;
5076 ssh2_pkt_getstring(&type, &typelen);
5077 c = smalloc(sizeof(struct ssh_channel));
5079 remid = ssh2_pkt_getuint32();
5080 winsize = ssh2_pkt_getuint32();
5081 pktsize = ssh2_pkt_getuint32();
5083 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5084 if (!ssh_X11_fwd_enabled)
5085 error = "X11 forwarding is not enabled";
5086 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5088 error = "Unable to open an X11 connection";
5092 } else if (typelen == 15 &&
5093 !memcmp(type, "forwarded-tcpip", 15)) {
5094 struct ssh_rportfwd pf, *realpf;
5097 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5098 pf.sport = ssh2_pkt_getuint32();
5099 realpf = find234(ssh_rportfwds, &pf, NULL);
5100 if (realpf == NULL) {
5101 error = "Remote port is not recognised";
5103 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5106 sprintf(buf, "Received remote port open request for %s:%d",
5107 realpf->dhost, realpf->dport);
5110 sprintf(buf, "Port open failed: %s", e);
5112 error = "Port open failed";
5114 logevent("Forwarded port opened successfully");
5115 c->type = CHAN_SOCKDATA;
5118 } else if (typelen == 22 &&
5119 !memcmp(type, "auth-agent@openssh.com", 3)) {
5120 if (!ssh_agentfwd_enabled)
5121 error = "Agent forwarding is not enabled";
5123 c->type = CHAN_AGENT; /* identify channel type */
5124 c->u.a.lensofar = 0;
5127 error = "Unsupported channel type requested";
5130 c->remoteid = remid;
5132 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5133 ssh2_pkt_adduint32(c->remoteid);
5134 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5135 ssh2_pkt_addstring(error);
5136 ssh2_pkt_addstring("en"); /* language tag */
5140 c->localid = alloc_channel_id();
5142 c->v.v2.locwindow = OUR_V2_WINSIZE;
5143 c->v.v2.remwindow = winsize;
5144 c->v.v2.remmaxpkt = pktsize;
5145 bufchain_init(&c->v.v2.outbuffer);
5146 add234(ssh_channels, c);
5147 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5148 ssh2_pkt_adduint32(c->remoteid);
5149 ssh2_pkt_adduint32(c->localid);
5150 ssh2_pkt_adduint32(c->v.v2.locwindow);
5151 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5155 bombout(("Strange packet received: type %d", pktin.type));
5160 * We have spare data. Add it to the channel buffer.
5162 ssh2_add_channel_data(mainchan, in, inlen);
5167 struct ssh_channel *c;
5169 * Try to send data on all channels if we can.
5171 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5172 int bufsize = ssh2_try_send(c);
5175 case CHAN_MAINSESSION:
5176 /* stdin need not receive an unthrottle
5177 * notification since it will be polled */
5180 x11_unthrottle(c->u.x11.s);
5183 /* agent sockets are request/response and need no
5184 * buffer management */
5187 pfd_unthrottle(c->u.pfd.s);
5199 * Handle the top-level SSH2 protocol.
5201 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5203 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5205 do_ssh2_authconn(in, inlen, ispkt);
5209 * Called to set up the connection.
5211 * Returns an error message, or NULL on success.
5213 static char *ssh_init(char *host, int port, char **realhost, int nodelay)
5218 if (crypto_startup() == 0)
5219 return "Microsoft high encryption pack not installed!";
5225 ssh1_throttle_count = 0;
5226 ssh_overall_bufsize = 0;
5227 ssh_fallback_cmd = 0;
5229 p = connect_to_host(host, port, realhost, nodelay);
5237 * Called to send data down the Telnet connection.
5239 static int ssh_send(char *buf, int len)
5241 if (s == NULL || ssh_protocol == NULL)
5244 ssh_protocol(buf, len, 0);
5246 return ssh_sendbuffer();
5250 * Called to query the current amount of buffered stdin data.
5252 static int ssh_sendbuffer(void)
5256 if (s == NULL || ssh_protocol == NULL)
5260 * If the SSH socket itself has backed up, add the total backup
5261 * size on that to any individual buffer on the stdin channel.
5264 if (ssh_throttled_all)
5265 override_value = ssh_overall_bufsize;
5267 if (ssh_version == 1) {
5268 return override_value;
5269 } else if (ssh_version == 2) {
5270 if (!mainchan || mainchan->closes > 0)
5271 return override_value;
5273 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5280 * Called to set the size of the window from SSH's POV.
5282 static void ssh_size(void)
5284 switch (ssh_state) {
5285 case SSH_STATE_BEFORE_SIZE:
5286 case SSH_STATE_PREPACKET:
5287 case SSH_STATE_CLOSED:
5288 break; /* do nothing */
5289 case SSH_STATE_INTERMED:
5290 size_needed = TRUE; /* buffer for later */
5292 case SSH_STATE_SESSION:
5294 if (ssh_version == 1) {
5295 send_packet(SSH1_CMSG_WINDOW_SIZE,
5296 PKT_INT, rows, PKT_INT, cols,
5297 PKT_INT, 0, PKT_INT, 0, PKT_END);
5299 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5300 ssh2_pkt_adduint32(mainchan->remoteid);
5301 ssh2_pkt_addstring("window-change");
5302 ssh2_pkt_addbool(0);
5303 ssh2_pkt_adduint32(cols);
5304 ssh2_pkt_adduint32(rows);
5305 ssh2_pkt_adduint32(0);
5306 ssh2_pkt_adduint32(0);
5315 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5316 * can send an EOF and collect resulting output (e.g. `plink
5319 static void ssh_special(Telnet_Special code)
5321 if (code == TS_EOF) {
5322 if (ssh_state != SSH_STATE_SESSION) {
5324 * Buffer the EOF in case we are pre-SESSION, so we can
5325 * send it as soon as we reach SESSION.
5331 if (ssh_version == 1) {
5332 send_packet(SSH1_CMSG_EOF, PKT_END);
5334 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5335 ssh2_pkt_adduint32(mainchan->remoteid);
5338 logevent("Sent EOF message");
5339 } else if (code == TS_PING) {
5340 if (ssh_state == SSH_STATE_CLOSED
5341 || ssh_state == SSH_STATE_PREPACKET) return;
5342 if (ssh_version == 1) {
5343 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5345 ssh2_pkt_init(SSH2_MSG_IGNORE);
5346 ssh2_pkt_addstring_start();
5354 void *new_sock_channel(Socket s)
5356 struct ssh_channel *c;
5357 c = smalloc(sizeof(struct ssh_channel));
5360 c->remoteid = -1; /* to be set when open confirmed */
5361 c->localid = alloc_channel_id();
5363 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5365 add234(ssh_channels, c);
5371 * This is called when stdout/stderr (the entity to which
5372 * from_backend sends data) manages to clear some backlog.
5374 void ssh_unthrottle(int bufsize)
5376 if (ssh_version == 1) {
5377 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5378 ssh1_stdout_throttling = 0;
5382 if (mainchan && mainchan->closes == 0)
5383 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5387 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5389 struct ssh_channel *c = (struct ssh_channel *)channel;
5392 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5395 if (ssh_version == 1) {
5396 send_packet(SSH1_MSG_PORT_OPEN,
5397 PKT_INT, c->localid,
5400 //PKT_STR, <org:orgport>,
5403 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5404 ssh2_pkt_addstring("direct-tcpip");
5405 ssh2_pkt_adduint32(c->localid);
5406 c->v.v2.locwindow = OUR_V2_WINSIZE;
5407 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5408 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5409 ssh2_pkt_addstring(hostname);
5410 ssh2_pkt_adduint32(port);
5412 * We make up values for the originator data; partly it's
5413 * too much hassle to keep track, and partly I'm not
5414 * convinced the server should be told details like that
5415 * about my local network configuration.
5417 ssh2_pkt_addstring("client-side-connection");
5418 ssh2_pkt_adduint32(0);
5424 static Socket ssh_socket(void)
5429 static int ssh_sendok(void)
5434 static int ssh_ldisc(int option)
5436 if (option == LD_ECHO)
5438 if (option == LD_EDIT)
5443 Backend ssh_backend = {