18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
22 /* logevent, only printf-formatted. */
23 void logeventf(char *fmt, ...)
29 vsprintf(stuff, fmt, ap);
34 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
35 (s ? sk_close(s), s = NULL : 0), \
36 logeventf msg, connection_fatal msg )
38 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41 #define SSH1_CMSG_USER 4 /* 0x4 */
42 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
51 #define SSH1_SMSG_FAILURE 15 /* 0xf */
52 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55 #define SSH1_CMSG_EOF 19 /* 0x13 */
56 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67 #define SSH1_MSG_IGNORE 32 /* 0x20 */
68 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71 #define SSH1_MSG_DEBUG 36 /* 0x24 */
72 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
80 #define SSH1_AUTH_TIS 5 /* 0x5 */
81 #define SSH1_AUTH_CCARD 16 /* 0x10 */
83 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
84 /* Mask for protoflags we will echo back to server if seen */
85 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
87 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88 #define SSH2_MSG_IGNORE 2 /* 0x2 */
89 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90 #define SSH2_MSG_DEBUG 4 /* 0x4 */
91 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
94 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
107 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
109 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
128 #define SSH2_PKTCTX_DHGROUP1 0x0001
129 #define SSH2_PKTCTX_DHGEX 0x0002
130 #define SSH2_PKTCTX_PUBLICKEY 0x0010
131 #define SSH2_PKTCTX_PASSWORD 0x0020
132 #define SSH2_PKTCTX_KBDINTER 0x0040
133 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
135 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
151 static const char *const ssh2_disconnect_reasons[] = {
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
170 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
175 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
178 * Various remote-bug flags.
180 #define BUG_CHOKES_ON_SSH1_IGNORE 1
181 #define BUG_SSH2_HMAC 2
182 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
183 #define BUG_CHOKES_ON_RSA 8
185 static int ssh_pkt_ctx = 0;
187 #define translate(x) if (type == x) return #x
188 #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
189 char *ssh1_pkt_type(int type)
191 translate(SSH1_MSG_DISCONNECT);
192 translate(SSH1_SMSG_PUBLIC_KEY);
193 translate(SSH1_CMSG_SESSION_KEY);
194 translate(SSH1_CMSG_USER);
195 translate(SSH1_CMSG_AUTH_RSA);
196 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
197 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
198 translate(SSH1_CMSG_AUTH_PASSWORD);
199 translate(SSH1_CMSG_REQUEST_PTY);
200 translate(SSH1_CMSG_WINDOW_SIZE);
201 translate(SSH1_CMSG_EXEC_SHELL);
202 translate(SSH1_CMSG_EXEC_CMD);
203 translate(SSH1_SMSG_SUCCESS);
204 translate(SSH1_SMSG_FAILURE);
205 translate(SSH1_CMSG_STDIN_DATA);
206 translate(SSH1_SMSG_STDOUT_DATA);
207 translate(SSH1_SMSG_STDERR_DATA);
208 translate(SSH1_CMSG_EOF);
209 translate(SSH1_SMSG_EXIT_STATUS);
210 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
211 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
212 translate(SSH1_MSG_CHANNEL_DATA);
213 translate(SSH1_MSG_CHANNEL_CLOSE);
214 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
215 translate(SSH1_SMSG_X11_OPEN);
216 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
217 translate(SSH1_MSG_PORT_OPEN);
218 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
219 translate(SSH1_SMSG_AGENT_OPEN);
220 translate(SSH1_MSG_IGNORE);
221 translate(SSH1_CMSG_EXIT_CONFIRMATION);
222 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
223 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
224 translate(SSH1_MSG_DEBUG);
225 translate(SSH1_CMSG_REQUEST_COMPRESSION);
226 translate(SSH1_CMSG_AUTH_TIS);
227 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
228 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
229 translate(SSH1_CMSG_AUTH_CCARD);
230 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
231 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
234 char *ssh2_pkt_type(int type)
236 translate(SSH2_MSG_DISCONNECT);
237 translate(SSH2_MSG_IGNORE);
238 translate(SSH2_MSG_UNIMPLEMENTED);
239 translate(SSH2_MSG_DEBUG);
240 translate(SSH2_MSG_SERVICE_REQUEST);
241 translate(SSH2_MSG_SERVICE_ACCEPT);
242 translate(SSH2_MSG_KEXINIT);
243 translate(SSH2_MSG_NEWKEYS);
244 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
245 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
246 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
247 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
248 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
249 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
250 translate(SSH2_MSG_USERAUTH_REQUEST);
251 translate(SSH2_MSG_USERAUTH_FAILURE);
252 translate(SSH2_MSG_USERAUTH_SUCCESS);
253 translate(SSH2_MSG_USERAUTH_BANNER);
254 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
255 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
256 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
257 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
258 translate(SSH2_MSG_GLOBAL_REQUEST);
259 translate(SSH2_MSG_REQUEST_SUCCESS);
260 translate(SSH2_MSG_REQUEST_FAILURE);
261 translate(SSH2_MSG_CHANNEL_OPEN);
262 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
263 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
264 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
265 translate(SSH2_MSG_CHANNEL_DATA);
266 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
267 translate(SSH2_MSG_CHANNEL_EOF);
268 translate(SSH2_MSG_CHANNEL_CLOSE);
269 translate(SSH2_MSG_CHANNEL_REQUEST);
270 translate(SSH2_MSG_CHANNEL_SUCCESS);
271 translate(SSH2_MSG_CHANNEL_FAILURE);
277 #define GET_32BIT(cp) \
278 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
279 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
280 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
281 ((unsigned long)(unsigned char)(cp)[3]))
283 #define PUT_32BIT(cp, value) { \
284 (cp)[0] = (unsigned char)((value) >> 24); \
285 (cp)[1] = (unsigned char)((value) >> 16); \
286 (cp)[2] = (unsigned char)((value) >> 8); \
287 (cp)[3] = (unsigned char)(value); }
289 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
291 /* Coroutine mechanics for the sillier bits of the code */
292 #define crBegin1 static int crLine = 0;
293 #define crBegin2 switch(crLine) { case 0:;
294 #define crBegin crBegin1; crBegin2;
295 #define crFinish(z) } crLine = 0; return (z)
296 #define crFinishV } crLine = 0; return
297 #define crReturn(z) \
299 crLine=__LINE__; return (z); case __LINE__:;\
303 crLine=__LINE__; return; case __LINE__:;\
305 #define crStop(z) do{ crLine = 0; return (z); }while(0)
306 #define crStopV do{ crLine = 0; return; }while(0)
307 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
308 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
310 extern char *x11_init(Socket *, char *, void *);
311 extern void x11_close(Socket);
312 extern int x11_send(Socket, char *, int);
313 extern void x11_invent_auth(char *, int, char *, int);
314 extern void x11_unthrottle(Socket s);
315 extern void x11_override_throttle(Socket s, int enable);
317 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
318 extern char *pfd_addforward(char *desthost, int destport, int port);
319 extern void pfd_close(Socket s);
320 extern int pfd_send(Socket s, char *data, int len);
321 extern void pfd_confirm(Socket s);
322 extern void pfd_unthrottle(Socket s);
323 extern void pfd_override_throttle(Socket s, int enable);
325 static void ssh2_pkt_init(int pkt_type);
326 static void ssh2_pkt_addbool(unsigned char value);
327 static void ssh2_pkt_adduint32(unsigned long value);
328 static void ssh2_pkt_addstring_start(void);
329 static void ssh2_pkt_addstring_str(char *data);
330 static void ssh2_pkt_addstring_data(char *data, int len);
331 static void ssh2_pkt_addstring(char *data);
332 static char *ssh2_mpint_fmt(Bignum b, int *len);
333 static void ssh2_pkt_addmp(Bignum b);
334 static int ssh2_pkt_construct(void);
335 static void ssh2_pkt_send(void);
338 * Buffer management constants. There are several of these for
339 * various different purposes:
341 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
342 * on a local data stream before we throttle the whole SSH
343 * connection (in SSH1 only). Throttling the whole connection is
344 * pretty drastic so we set this high in the hope it won't
347 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
348 * on the SSH connection itself before we defensively throttle
349 * _all_ local data streams. This is pretty drastic too (though
350 * thankfully unlikely in SSH2 since the window mechanism should
351 * ensure that the server never has any need to throttle its end
352 * of the connection), so we set this high as well.
354 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
358 #define SSH1_BUFFER_LIMIT 32768
359 #define SSH_MAX_BACKLOG 32768
360 #define OUR_V2_WINSIZE 16384
362 const static struct ssh_kex *kex_algs[] = {
363 &ssh_diffiehellman_gex,
367 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
369 static void nullmac_key(unsigned char *key)
372 static void nullmac_generate(unsigned char *blk, int len,
376 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
380 const static struct ssh_mac ssh_mac_none = {
381 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
383 const static struct ssh_mac *macs[] = {
384 &ssh_sha1, &ssh_md5, &ssh_mac_none
386 const static struct ssh_mac *buggymacs[] = {
387 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
390 static void ssh_comp_none_init(void)
393 static int ssh_comp_none_block(unsigned char *block, int len,
394 unsigned char **outblock, int *outlen)
398 static int ssh_comp_none_disable(void)
402 const static struct ssh_compress ssh_comp_none = {
404 ssh_comp_none_init, ssh_comp_none_block,
405 ssh_comp_none_init, ssh_comp_none_block,
406 ssh_comp_none_disable
408 extern const struct ssh_compress ssh_zlib;
409 const static struct ssh_compress *compressions[] = {
410 &ssh_zlib, &ssh_comp_none
413 enum { /* channel types */
418 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
422 * 2-3-4 tree storing channels.
425 unsigned remoteid, localid;
429 struct ssh1_data_channel {
432 struct ssh2_data_channel {
434 unsigned remwindow, remmaxpkt;
439 struct ssh_agent_channel {
440 unsigned char *message;
441 unsigned char msglen[4];
442 int lensofar, totallen;
444 struct ssh_x11_channel {
447 struct ssh_pfd_channel {
454 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
455 * 2 use this structure in different ways, reflecting SSH 2's
456 * altogether saner approach to port forwarding.
458 * In SSH 1, you arrange a remote forwarding by sending the server
459 * the remote port number, and the local destination host:port.
460 * When a connection comes in, the server sends you back that
461 * host:port pair, and you connect to it. This is a ready-made
462 * security hole if you're not on the ball: a malicious server
463 * could send you back _any_ host:port pair, so if you trustingly
464 * connect to the address it gives you then you've just opened the
465 * entire inside of your corporate network just by connecting
466 * through it to a dodgy SSH server. Hence, we must store a list of
467 * host:port pairs we _are_ trying to forward to, and reject a
468 * connection request from the server if it's not in the list.
470 * In SSH 2, each side of the connection minds its own business and
471 * doesn't send unnecessary information to the other. You arrange a
472 * remote forwarding by sending the server just the remote port
473 * number. When a connection comes in, the server tells you which
474 * of its ports was connected to; and _you_ have to remember what
475 * local host:port pair went with that port number.
477 * Hence: in SSH 1 this structure stores host:port pairs we intend
478 * to allow connections to, and is indexed by those host:port
479 * pairs. In SSH 2 it stores a mapping from source port to
480 * destination host:port pair, and is indexed by source port.
482 struct ssh_rportfwd {
483 unsigned sport, dport;
496 static SHA_State exhash, exhashbase;
498 static Socket s = NULL;
500 static unsigned char session_key[32];
501 static int ssh1_compressing;
502 static int ssh1_remote_protoflags;
503 static int ssh1_local_protoflags;
504 static int ssh_agentfwd_enabled;
505 static int ssh_X11_fwd_enabled;
506 static int ssh_remote_bugs;
507 static const struct ssh_cipher *cipher = NULL;
508 static const struct ssh2_cipher *cscipher = NULL;
509 static const struct ssh2_cipher *sccipher = NULL;
510 static const struct ssh_mac *csmac = NULL;
511 static const struct ssh_mac *scmac = NULL;
512 static const struct ssh_compress *cscomp = NULL;
513 static const struct ssh_compress *sccomp = NULL;
514 static const struct ssh_kex *kex = NULL;
515 static const struct ssh_signkey *hostkey = NULL;
516 static unsigned char ssh2_session_id[20];
517 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
520 static char *savedhost;
521 static int savedport;
522 static int ssh_send_ok;
523 static int ssh_echoing, ssh_editing;
525 static tree234 *ssh_channels; /* indexed by local id */
526 static struct ssh_channel *mainchan; /* primary session channel */
527 static int ssh_exitcode = -1;
529 static tree234 *ssh_rportfwds;
533 SSH_STATE_BEFORE_SIZE,
537 } ssh_state = SSH_STATE_PREPACKET;
539 static int size_needed = FALSE, eof_needed = FALSE;
541 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
542 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
543 static unsigned char *deferred_send_data = NULL;
544 static int deferred_len = 0, deferred_size = 0;
547 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
548 * that fails. This variable is the means by which scp.c can reach
549 * into the SSH code and find out which one it got.
551 int ssh_fallback_cmd = 0;
553 static int ssh_version;
554 static int ssh1_throttle_count;
555 static int ssh_overall_bufsize;
556 static int ssh_throttled_all;
557 static int ssh1_stdout_throttling;
558 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
559 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
560 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
561 static void ssh_size(void);
562 static void ssh_special(Telnet_Special);
563 static int ssh2_try_send(struct ssh_channel *c);
564 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
566 static void ssh_throttle_all(int enable, int bufsize);
567 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
568 static int (*s_rdpkt) (unsigned char **data, int *datalen);
569 static int ssh_sendbuffer(void);
571 static struct rdpkt1_state_tag {
572 long len, pad, biglen, to_read;
573 unsigned long realcrc, gotcrc;
579 static struct rdpkt2_state_tag {
580 long len, pad, payload, packetlen, maclen;
583 unsigned long incoming_sequence;
586 static int ssh_channelcmp(void *av, void *bv)
588 struct ssh_channel *a = (struct ssh_channel *) av;
589 struct ssh_channel *b = (struct ssh_channel *) bv;
590 if (a->localid < b->localid)
592 if (a->localid > b->localid)
596 static int ssh_channelfind(void *av, void *bv)
598 unsigned *a = (unsigned *) av;
599 struct ssh_channel *b = (struct ssh_channel *) bv;
607 static int ssh_rportcmp_ssh1(void *av, void *bv)
609 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
610 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
612 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
613 return i < 0 ? -1 : +1;
614 if (a->dport > b->dport)
616 if (a->dport < b->dport)
621 static int ssh_rportcmp_ssh2(void *av, void *bv)
623 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
624 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
626 if (a->sport > b->sport)
628 if (a->sport < b->sport)
633 static int alloc_channel_id(void)
635 const unsigned CHANNEL_NUMBER_OFFSET = 256;
636 unsigned low, high, mid;
638 struct ssh_channel *c;
641 * First-fit allocation of channel numbers: always pick the
642 * lowest unused one. To do this, binary-search using the
643 * counted B-tree to find the largest channel ID which is in a
644 * contiguous sequence from the beginning. (Precisely
645 * everything in that sequence must have ID equal to its tree
646 * index plus CHANNEL_NUMBER_OFFSET.)
648 tsize = count234(ssh_channels);
652 while (high - low > 1) {
653 mid = (high + low) / 2;
654 c = index234(ssh_channels, mid);
655 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
656 low = mid; /* this one is fine */
658 high = mid; /* this one is past it */
661 * Now low points to either -1, or the tree index of the
662 * largest ID in the initial sequence.
665 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
666 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
668 return low + 1 + CHANNEL_NUMBER_OFFSET;
671 static void c_write(char *buf, int len)
673 if ((flags & FLAG_STDERR)) {
675 for (i = 0; i < len; i++)
677 fputc(buf[i], stderr);
680 from_backend(1, buf, len);
683 static void c_write_untrusted(char *buf, int len)
686 for (i = 0; i < len; i++) {
689 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
694 static void c_write_str(char *buf)
696 c_write(buf, strlen(buf));
700 * Collect incoming data in the incoming packet buffer.
701 * Decipher and verify the packet when it is completely read.
702 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
703 * Update the *data and *datalen variables.
704 * Return the additional nr of bytes needed, or 0 when
705 * a complete packet is available.
707 static int ssh1_rdpkt(unsigned char **data, int *datalen)
709 struct rdpkt1_state_tag *st = &rdpkt1_state;
718 for (st->i = st->len = 0; st->i < 4; st->i++) {
719 while ((*datalen) == 0)
721 st->len = (st->len << 8) + **data;
722 (*data)++, (*datalen)--;
725 st->pad = 8 - (st->len % 8);
726 st->biglen = st->len + st->pad;
727 pktin.length = st->len - 5;
729 if (pktin.maxlen < st->biglen) {
730 pktin.maxlen = st->biglen;
731 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
732 srealloc(pktin.data, st->biglen + APIEXTRA));
734 fatalbox("Out of memory");
737 st->to_read = st->biglen;
739 while (st->to_read > 0) {
740 st->chunk = st->to_read;
741 while ((*datalen) == 0)
742 crReturn(st->to_read);
743 if (st->chunk > (*datalen))
744 st->chunk = (*datalen);
745 memcpy(st->p, *data, st->chunk);
747 *datalen -= st->chunk;
749 st->to_read -= st->chunk;
752 if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
753 bombout(("Network attack (CRC compensation) detected!"));
758 cipher->decrypt(pktin.data, st->biglen);
760 st->realcrc = crc32(pktin.data, st->biglen - 4);
761 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
762 if (st->gotcrc != st->realcrc) {
763 bombout(("Incorrect CRC received on packet"));
767 pktin.body = pktin.data + st->pad + 1;
769 if (ssh1_compressing) {
770 unsigned char *decompblk;
772 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
773 &decompblk, &decomplen);
775 if (pktin.maxlen < st->pad + decomplen) {
776 pktin.maxlen = st->pad + decomplen;
777 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
778 pktin.body = pktin.data + st->pad + 1;
780 fatalbox("Out of memory");
783 memcpy(pktin.body - 1, decompblk, decomplen);
785 pktin.length = decomplen - 1;
788 pktin.type = pktin.body[-1];
790 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
791 pktin.body, pktin.length);
793 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
794 pktin.type == SSH1_SMSG_STDERR_DATA ||
795 pktin.type == SSH1_MSG_DEBUG ||
796 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
797 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
798 long stringlen = GET_32BIT(pktin.body);
799 if (stringlen + 4 != pktin.length) {
800 bombout(("Received data packet with bogus string length"));
805 if (pktin.type == SSH1_MSG_DEBUG) {
806 /* log debug message */
808 int stringlen = GET_32BIT(pktin.body);
809 strcpy(buf, "Remote: ");
812 memcpy(buf + 8, pktin.body + 4, stringlen);
813 buf[8 + stringlen] = '\0';
816 } else if (pktin.type == SSH1_MSG_IGNORE) {
821 if (pktin.type == SSH1_MSG_DISCONNECT) {
822 /* log reason code in disconnect message */
824 unsigned msglen = GET_32BIT(pktin.body);
826 strcpy(buf, "Remote sent disconnect: ");
827 nowlen = strlen(buf);
828 if (msglen > sizeof(buf) - nowlen - 1)
829 msglen = sizeof(buf) - nowlen - 1;
830 memcpy(buf + nowlen, pktin.body + 4, msglen);
831 buf[nowlen + msglen] = '\0';
832 /* logevent(buf); (this is now done within the bombout macro) */
833 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
840 static int ssh2_rdpkt(unsigned char **data, int *datalen)
842 struct rdpkt2_state_tag *st = &rdpkt2_state;
850 st->cipherblk = sccipher->blksize;
853 if (st->cipherblk < 8)
856 if (pktin.maxlen < st->cipherblk) {
857 pktin.maxlen = st->cipherblk;
860 NULL ? smalloc(st->cipherblk +
861 APIEXTRA) : srealloc(pktin.data,
865 fatalbox("Out of memory");
869 * Acquire and decrypt the first block of the packet. This will
870 * contain the length and padding details.
872 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
873 while ((*datalen) == 0)
874 crReturn(st->cipherblk - st->i);
875 pktin.data[st->i] = *(*data)++;
880 sccipher->decrypt(pktin.data, st->cipherblk);
883 * Now get the length and padding figures.
885 st->len = GET_32BIT(pktin.data);
886 st->pad = pktin.data[4];
889 * This enables us to deduce the payload length.
891 st->payload = st->len - st->pad - 1;
893 pktin.length = st->payload + 5;
896 * So now we can work out the total packet length.
898 st->packetlen = st->len + 4;
899 st->maclen = scmac ? scmac->len : 0;
902 * Adjust memory allocation if packet is too big.
904 if (pktin.maxlen < st->packetlen + st->maclen) {
905 pktin.maxlen = st->packetlen + st->maclen;
908 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
913 fatalbox("Out of memory");
917 * Read and decrypt the remainder of the packet.
919 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
921 while ((*datalen) == 0)
922 crReturn(st->packetlen + st->maclen - st->i);
923 pktin.data[st->i] = *(*data)++;
926 /* Decrypt everything _except_ the MAC. */
928 sccipher->decrypt(pktin.data + st->cipherblk,
929 st->packetlen - st->cipherblk);
935 && !scmac->verify(pktin.data, st->len + 4,
936 st->incoming_sequence)) {
937 bombout(("Incorrect MAC received on packet"));
940 st->incoming_sequence++; /* whether or not we MACed */
943 * Decompress packet payload.
946 unsigned char *newpayload;
948 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
949 &newpayload, &newlen)) {
950 if (pktin.maxlen < newlen + 5) {
951 pktin.maxlen = newlen + 5;
954 NULL ? smalloc(pktin.maxlen +
955 APIEXTRA) : srealloc(pktin.data,
959 fatalbox("Out of memory");
961 pktin.length = 5 + newlen;
962 memcpy(pktin.data + 5, newpayload, newlen);
968 pktin.type = pktin.data[5];
970 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
971 pktin.data+6, pktin.length-6);
973 switch (pktin.type) {
975 * These packets we must handle instantly.
977 case SSH2_MSG_DISCONNECT:
979 /* log reason code in disconnect message */
981 int reason = GET_32BIT(pktin.data + 6);
982 unsigned msglen = GET_32BIT(pktin.data + 10);
984 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
985 sprintf(buf, "Received disconnect message (%s)",
986 ssh2_disconnect_reasons[reason]);
988 sprintf(buf, "Received disconnect message (unknown type %d)",
992 strcpy(buf, "Disconnection message text: ");
993 nowlen = strlen(buf);
994 if (msglen > sizeof(buf) - nowlen - 1)
995 msglen = sizeof(buf) - nowlen - 1;
996 memcpy(buf + nowlen, pktin.data + 14, msglen);
997 buf[nowlen + msglen] = '\0';
999 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1001 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1002 ssh2_disconnect_reasons[reason] : "unknown",
1007 case SSH2_MSG_IGNORE:
1009 case SSH2_MSG_DEBUG:
1011 /* log the debug message */
1013 /* int display = pktin.body[6]; */
1014 int stringlen = GET_32BIT(pktin.data+7);
1016 strcpy(buf, "Remote debug message: ");
1017 prefix = strlen(buf);
1018 if (stringlen > sizeof(buf)-prefix-1)
1019 stringlen = sizeof(buf)-prefix-1;
1020 memcpy(buf + prefix, pktin.data + 11, stringlen);
1021 buf[prefix + stringlen] = '\0';
1024 goto next_packet; /* FIXME: print the debug message */
1027 * These packets we need do nothing about here.
1029 case SSH2_MSG_UNIMPLEMENTED:
1030 case SSH2_MSG_SERVICE_REQUEST:
1031 case SSH2_MSG_SERVICE_ACCEPT:
1032 case SSH2_MSG_KEXINIT:
1033 case SSH2_MSG_NEWKEYS:
1034 case SSH2_MSG_KEXDH_INIT:
1035 case SSH2_MSG_KEXDH_REPLY:
1036 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1037 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1038 case SSH2_MSG_KEX_DH_GEX_INIT:
1039 case SSH2_MSG_KEX_DH_GEX_REPLY:
1040 case SSH2_MSG_USERAUTH_REQUEST:
1041 case SSH2_MSG_USERAUTH_FAILURE:
1042 case SSH2_MSG_USERAUTH_SUCCESS:
1043 case SSH2_MSG_USERAUTH_BANNER:
1044 case SSH2_MSG_USERAUTH_PK_OK:
1045 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1046 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1047 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1048 case SSH2_MSG_GLOBAL_REQUEST:
1049 case SSH2_MSG_REQUEST_SUCCESS:
1050 case SSH2_MSG_REQUEST_FAILURE:
1051 case SSH2_MSG_CHANNEL_OPEN:
1052 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1053 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1054 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1055 case SSH2_MSG_CHANNEL_DATA:
1056 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1057 case SSH2_MSG_CHANNEL_EOF:
1058 case SSH2_MSG_CHANNEL_CLOSE:
1059 case SSH2_MSG_CHANNEL_REQUEST:
1060 case SSH2_MSG_CHANNEL_SUCCESS:
1061 case SSH2_MSG_CHANNEL_FAILURE:
1065 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1068 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
1069 ssh2_pkt_adduint32(st->incoming_sequence - 1);
1077 static void ssh1_pktout_size(int len)
1081 len += 5; /* type and CRC */
1082 pad = 8 - (len % 8);
1085 pktout.length = len - 5;
1086 if (pktout.maxlen < biglen) {
1087 pktout.maxlen = biglen;
1089 /* Allocate enough buffer space for extra block
1090 * for MS CryptEncrypt() */
1091 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
1092 srealloc(pktout.data, biglen + 12));
1094 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
1095 srealloc(pktout.data, biglen + 4));
1098 fatalbox("Out of memory");
1100 pktout.body = pktout.data + 4 + pad + 1;
1103 static void s_wrpkt_start(int type, int len)
1105 ssh1_pktout_size(len);
1109 static int s_wrpkt_prepare(void)
1111 int pad, len, biglen, i;
1114 pktout.body[-1] = pktout.type;
1116 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1117 pktout.body, pktout.length);
1119 if (ssh1_compressing) {
1120 unsigned char *compblk;
1122 zlib_compress_block(pktout.body - 1, pktout.length + 1,
1123 &compblk, &complen);
1124 ssh1_pktout_size(complen - 1);
1125 memcpy(pktout.body - 1, compblk, complen);
1129 len = pktout.length + 5; /* type and CRC */
1130 pad = 8 - (len % 8);
1133 for (i = 0; i < pad; i++)
1134 pktout.data[i + 4] = random_byte();
1135 crc = crc32(pktout.data + 4, biglen - 4);
1136 PUT_32BIT(pktout.data + biglen, crc);
1137 PUT_32BIT(pktout.data, len);
1140 cipher->encrypt(pktout.data + 4, biglen);
1145 static void s_wrpkt(void)
1148 len = s_wrpkt_prepare();
1149 backlog = sk_write(s, pktout.data, len);
1150 if (backlog > SSH_MAX_BACKLOG)
1151 ssh_throttle_all(1, backlog);
1154 static void s_wrpkt_defer(void)
1157 len = s_wrpkt_prepare();
1158 if (deferred_len + len > deferred_size) {
1159 deferred_size = deferred_len + len + 128;
1160 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1162 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1163 deferred_len += len;
1167 * Construct a packet with the specified contents.
1169 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1171 unsigned char *p, *argp, argchar;
1172 unsigned long argint;
1173 int pktlen, argtype, arglen;
1177 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1180 (void) va_arg(ap1, int);
1184 (void) va_arg(ap1, char);
1188 (void) va_arg(ap1, unsigned char *);
1189 arglen = va_arg(ap1, int);
1193 argp = va_arg(ap1, unsigned char *);
1194 arglen = strlen(argp);
1195 pktlen += 4 + arglen;
1198 bn = va_arg(ap1, Bignum);
1199 pktlen += ssh1_bignum_length(bn);
1206 s_wrpkt_start(pkttype, pktlen);
1209 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1212 argint = va_arg(ap2, int);
1213 PUT_32BIT(p, argint);
1217 argchar = va_arg(ap2, unsigned char);
1222 argp = va_arg(ap2, unsigned char *);
1223 arglen = va_arg(ap2, int);
1224 memcpy(p, argp, arglen);
1228 argp = va_arg(ap2, unsigned char *);
1229 arglen = strlen(argp);
1230 PUT_32BIT(p, arglen);
1231 memcpy(p + 4, argp, arglen);
1235 bn = va_arg(ap2, Bignum);
1236 p += ssh1_write_bignum(p, bn);
1242 static void send_packet(int pkttype, ...)
1245 va_start(ap1, pkttype);
1246 va_start(ap2, pkttype);
1247 construct_packet(pkttype, ap1, ap2);
1251 static void defer_packet(int pkttype, ...)
1254 va_start(ap1, pkttype);
1255 va_start(ap2, pkttype);
1256 construct_packet(pkttype, ap1, ap2);
1260 static int ssh_versioncmp(char *a, char *b)
1263 unsigned long av, bv;
1265 av = strtoul(a, &ae, 10);
1266 bv = strtoul(b, &be, 10);
1268 return (av < bv ? -1 : +1);
1273 av = strtoul(ae, &ae, 10);
1274 bv = strtoul(be, &be, 10);
1276 return (av < bv ? -1 : +1);
1282 * Utility routines for putting an SSH-protocol `string' and
1283 * `uint32' into a SHA state.
1286 static void sha_string(SHA_State * s, void *str, int len)
1288 unsigned char lenblk[4];
1289 PUT_32BIT(lenblk, len);
1290 SHA_Bytes(s, lenblk, 4);
1291 SHA_Bytes(s, str, len);
1294 static void sha_uint32(SHA_State * s, unsigned i)
1296 unsigned char intblk[4];
1297 PUT_32BIT(intblk, i);
1298 SHA_Bytes(s, intblk, 4);
1302 * SSH2 packet construction functions.
1304 static void ssh2_pkt_ensure(int length)
1306 if (pktout.maxlen < length) {
1307 pktout.maxlen = length + 256;
1310 NULL ? smalloc(pktout.maxlen +
1311 APIEXTRA) : srealloc(pktout.data,
1315 fatalbox("Out of memory");
1318 static void ssh2_pkt_adddata(void *data, int len)
1320 pktout.length += len;
1321 ssh2_pkt_ensure(pktout.length);
1322 memcpy(pktout.data + pktout.length - len, data, len);
1324 static void ssh2_pkt_addbyte(unsigned char byte)
1326 ssh2_pkt_adddata(&byte, 1);
1328 static void ssh2_pkt_init(int pkt_type)
1331 ssh2_pkt_addbyte((unsigned char) pkt_type);
1333 static void ssh2_pkt_addbool(unsigned char value)
1335 ssh2_pkt_adddata(&value, 1);
1337 static void ssh2_pkt_adduint32(unsigned long value)
1340 PUT_32BIT(x, value);
1341 ssh2_pkt_adddata(x, 4);
1343 static void ssh2_pkt_addstring_start(void)
1345 ssh2_pkt_adduint32(0);
1346 pktout.savedpos = pktout.length;
1348 static void ssh2_pkt_addstring_str(char *data)
1350 ssh2_pkt_adddata(data, strlen(data));
1351 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1352 pktout.length - pktout.savedpos);
1354 static void ssh2_pkt_addstring_data(char *data, int len)
1356 ssh2_pkt_adddata(data, len);
1357 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1358 pktout.length - pktout.savedpos);
1360 static void ssh2_pkt_addstring(char *data)
1362 ssh2_pkt_addstring_start();
1363 ssh2_pkt_addstring_str(data);
1365 static char *ssh2_mpint_fmt(Bignum b, int *len)
1368 int i, n = (bignum_bitcount(b) + 7) / 8;
1371 fatalbox("out of memory");
1373 for (i = 1; i <= n; i++)
1374 p[i] = bignum_byte(b, n - i);
1376 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1378 memmove(p, p + i, n + 1 - i);
1382 static void ssh2_pkt_addmp(Bignum b)
1386 p = ssh2_mpint_fmt(b, &len);
1387 ssh2_pkt_addstring_start();
1388 ssh2_pkt_addstring_data(p, len);
1393 * Construct an SSH2 final-form packet: compress it, encrypt it,
1394 * put the MAC on it. Final packet, ready to be sent, is stored in
1395 * pktout.data. Total length is returned.
1397 static int ssh2_pkt_construct(void)
1399 int cipherblk, maclen, padding, i;
1400 static unsigned long outgoing_sequence = 0;
1402 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1403 pktout.data + 6, pktout.length - 6);
1406 * Compress packet payload.
1409 unsigned char *newpayload;
1411 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1412 &newpayload, &newlen)) {
1414 ssh2_pkt_adddata(newpayload, newlen);
1420 * Add padding. At least four bytes, and must also bring total
1421 * length (minus MAC) up to a multiple of the block size.
1423 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1424 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1427 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1428 maclen = csmac ? csmac->len : 0;
1429 ssh2_pkt_ensure(pktout.length + padding + maclen);
1430 pktout.data[4] = padding;
1431 for (i = 0; i < padding; i++)
1432 pktout.data[pktout.length + i] = random_byte();
1433 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1435 csmac->generate(pktout.data, pktout.length + padding,
1437 outgoing_sequence++; /* whether or not we MACed */
1440 cscipher->encrypt(pktout.data, pktout.length + padding);
1442 /* Ready-to-send packet starts at pktout.data. We return length. */
1443 return pktout.length + padding + maclen;
1447 * Construct and send an SSH2 packet immediately.
1449 static void ssh2_pkt_send(void)
1453 len = ssh2_pkt_construct();
1454 backlog = sk_write(s, pktout.data, len);
1455 if (backlog > SSH_MAX_BACKLOG)
1456 ssh_throttle_all(1, backlog);
1460 * Construct an SSH2 packet and add it to a deferred data block.
1461 * Useful for sending multiple packets in a single sk_write() call,
1462 * to prevent a traffic-analysing listener from being able to work
1463 * out the length of any particular packet (such as the password
1466 * Note that because SSH2 sequence-numbers its packets, this can
1467 * NOT be used as an m4-style `defer' allowing packets to be
1468 * constructed in one order and sent in another.
1470 static void ssh2_pkt_defer(void)
1472 int len = ssh2_pkt_construct();
1473 if (deferred_len + len > deferred_size) {
1474 deferred_size = deferred_len + len + 128;
1475 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1477 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1478 deferred_len += len;
1482 * Send the whole deferred data block constructed by
1483 * ssh2_pkt_defer() or SSH1's defer_packet().
1485 static void ssh_pkt_defersend(void)
1488 backlog = sk_write(s, deferred_send_data, deferred_len);
1489 deferred_len = deferred_size = 0;
1490 sfree(deferred_send_data);
1491 deferred_send_data = NULL;
1492 if (backlog > SSH_MAX_BACKLOG)
1493 ssh_throttle_all(1, backlog);
1497 void bndebug(char *string, Bignum b)
1501 p = ssh2_mpint_fmt(b, &len);
1502 debug(("%s", string));
1503 for (i = 0; i < len; i++)
1504 debug((" %02x", p[i]));
1510 static void sha_mpint(SHA_State * s, Bignum b)
1514 p = ssh2_mpint_fmt(b, &len);
1515 sha_string(s, p, len);
1520 * SSH2 packet decode functions.
1522 static unsigned long ssh2_pkt_getuint32(void)
1524 unsigned long value;
1525 if (pktin.length - pktin.savedpos < 4)
1526 return 0; /* arrgh, no way to decline (FIXME?) */
1527 value = GET_32BIT(pktin.data + pktin.savedpos);
1528 pktin.savedpos += 4;
1531 static int ssh2_pkt_getbool(void)
1533 unsigned long value;
1534 if (pktin.length - pktin.savedpos < 1)
1535 return 0; /* arrgh, no way to decline (FIXME?) */
1536 value = pktin.data[pktin.savedpos] != 0;
1540 static void ssh2_pkt_getstring(char **p, int *length)
1543 if (pktin.length - pktin.savedpos < 4)
1545 *length = GET_32BIT(pktin.data + pktin.savedpos);
1546 pktin.savedpos += 4;
1547 if (pktin.length - pktin.savedpos < *length)
1549 *p = pktin.data + pktin.savedpos;
1550 pktin.savedpos += *length;
1552 static Bignum ssh2_pkt_getmp(void)
1558 ssh2_pkt_getstring(&p, &length);
1562 bombout(("internal error: Can't handle negative mpints"));
1565 b = bignum_from_bytes(p, length);
1570 * Examine the remote side's version string and compare it against
1571 * a list of known buggy implementations.
1573 static void ssh_detect_bugs(char *vstring)
1575 char *imp; /* pointer to implementation part */
1577 imp += strcspn(imp, "-");
1579 imp += strcspn(imp, "-");
1582 ssh_remote_bugs = 0;
1584 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1585 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1586 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
1588 * These versions don't support SSH1_MSG_IGNORE, so we have
1589 * to use a different defence against password length
1592 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1593 logevent("We believe remote version has SSH1 ignore bug");
1596 if (!strcmp(imp, "Cisco-1.25")) {
1598 * These versions need a plain password sent; they can't
1599 * handle having a null and a random length of data after
1602 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1603 logevent("We believe remote version needs a plain SSH1 password");
1606 if (!strcmp(imp, "Cisco-1.25")) {
1608 * These versions apparently have no clue whatever about
1609 * RSA authentication and will panic and die if they see
1610 * an AUTH_RSA message.
1612 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1613 logevent("We believe remote version can't handle RSA authentication");
1616 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1617 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1618 !strncmp(imp, "2.1 ", 4)) {
1620 * These versions have the HMAC bug.
1622 ssh_remote_bugs |= BUG_SSH2_HMAC;
1623 logevent("We believe remote version has SSH2 HMAC bug");
1627 static int do_ssh_init(unsigned char c)
1630 static char version[10];
1631 static char *vstring;
1632 static int vstrsize;
1638 /* Search for the string "SSH-" in the input. */
1641 static const int transS[] = { 1, 2, 2, 1 };
1642 static const int transH[] = { 0, 0, 3, 0 };
1643 static const int transminus[] = { 0, 0, 0, -1 };
1654 crReturn(1); /* get another character */
1658 vstring = smalloc(vstrsize);
1659 strcpy(vstring, "SSH-");
1663 crReturn(1); /* get another char */
1664 if (vslen >= vstrsize - 1) {
1666 vstring = srealloc(vstring, vstrsize);
1668 vstring[vslen++] = c;
1673 } else if (i < sizeof(version) - 1)
1675 } else if (c == '\n')
1679 ssh_agentfwd_enabled = FALSE;
1680 rdpkt2_state.incoming_sequence = 0;
1683 vlog = smalloc(20 + vslen);
1684 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
1685 sprintf(vlog, "Server version: %s", vstring);
1687 ssh_detect_bugs(vstring);
1691 * Server version "1.99" means we can choose whether we use v1
1692 * or v2 protocol. Choice is based on cfg.sshprot.
1694 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1696 * This is a v2 server. Begin v2 protocol.
1698 char verstring[80], vlog[100];
1699 sprintf(verstring, "SSH-2.0-%s", sshver);
1700 SHA_Init(&exhashbase);
1702 * Hash our version string and their version string.
1704 sha_string(&exhashbase, verstring, strlen(verstring));
1705 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1706 sprintf(vlog, "We claim version: %s", verstring);
1708 strcat(verstring, "\n");
1709 logevent("Using SSH protocol version 2");
1710 sk_write(s, verstring, strlen(verstring));
1711 ssh_protocol = ssh2_protocol;
1713 s_rdpkt = ssh2_rdpkt;
1716 * This is a v1 server. Begin v1 protocol.
1718 char verstring[80], vlog[100];
1719 sprintf(verstring, "SSH-%s-%s",
1720 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1722 sprintf(vlog, "We claim version: %s", verstring);
1724 strcat(verstring, "\n");
1725 logevent("Using SSH protocol version 1");
1726 sk_write(s, verstring, strlen(verstring));
1727 ssh_protocol = ssh1_protocol;
1729 s_rdpkt = ssh1_rdpkt;
1731 ssh_state = SSH_STATE_BEFORE_SIZE;
1738 static void ssh_gotdata(unsigned char *data, int datalen)
1743 * To begin with, feed the characters one by one to the
1744 * protocol initialisation / selection function do_ssh_init().
1745 * When that returns 0, we're done with the initial greeting
1746 * exchange and can move on to packet discipline.
1751 crReturnV; /* more data please */
1752 ret = do_ssh_init(*data);
1760 * We emerge from that loop when the initial negotiation is
1761 * over and we have selected an s_rdpkt function. Now pass
1762 * everything to s_rdpkt, and then pass the resulting packets
1763 * to the proper protocol handler.
1768 while (datalen > 0) {
1769 if (s_rdpkt(&data, &datalen) == 0) {
1770 if (ssh_state == SSH_STATE_CLOSED) {
1773 ssh_protocol(NULL, 0, 1);
1774 if (ssh_state == SSH_STATE_CLOSED) {
1784 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1787 ssh_state = SSH_STATE_CLOSED;
1793 /* A socket error has occurred. */
1794 logevent(error_msg);
1795 connection_fatal(error_msg);
1797 /* Otherwise, the remote side closed the connection normally. */
1802 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1804 ssh_gotdata(data, len);
1805 if (ssh_state == SSH_STATE_CLOSED) {
1815 static void ssh_sent(Plug plug, int bufsize)
1818 * If the send backlog on the SSH socket itself clears, we
1819 * should unthrottle the whole world if it was throttled.
1821 if (bufsize < SSH_MAX_BACKLOG)
1822 ssh_throttle_all(0, bufsize);
1826 * Connect to specified host and port.
1827 * Returns an error message, or NULL on success.
1828 * Also places the canonical host name into `realhost'. It must be
1829 * freed by the caller.
1831 static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
1833 static struct plug_function_table fn_table = {
1838 }, *fn_table_ptr = &fn_table;
1847 savedhost = smalloc(1 + strlen(host));
1849 fatalbox("Out of memory");
1850 strcpy(savedhost, host);
1853 port = 22; /* default ssh port */
1868 sprintf(buf, "Looking up host \"%.170s\"", host);
1871 addr = sk_namelookup(host, realhost);
1872 if ((err = sk_addr_error(addr)))
1876 *realhost = strdup(FWhost);
1883 char buf[200], addrbuf[100];
1884 sk_getaddr(addr, addrbuf, 100);
1885 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1888 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
1889 if ((err = sk_socket_error(s))) {
1895 sk_write(s, "connect ", 8);
1896 sk_write(s, FWhost, strlen(FWhost));
1899 sprintf(buf, " %d\n", FWport);
1900 sk_write(s, buf, strlen(buf));
1908 * Throttle or unthrottle the SSH connection.
1910 static void ssh1_throttle(int adjust)
1912 int old_count = ssh1_throttle_count;
1913 ssh1_throttle_count += adjust;
1914 assert(ssh1_throttle_count >= 0);
1915 if (ssh1_throttle_count && !old_count) {
1916 sk_set_frozen(s, 1);
1917 } else if (!ssh1_throttle_count && old_count) {
1918 sk_set_frozen(s, 0);
1923 * Throttle or unthrottle _all_ local data streams (for when sends
1924 * on the SSH connection itself back up).
1926 static void ssh_throttle_all(int enable, int bufsize)
1929 struct ssh_channel *c;
1931 if (enable == ssh_throttled_all)
1933 ssh_throttled_all = enable;
1934 ssh_overall_bufsize = bufsize;
1937 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
1939 case CHAN_MAINSESSION:
1941 * This is treated separately, outside the switch.
1945 x11_override_throttle(c->u.x11.s, enable);
1948 /* Agent channels require no buffer management. */
1951 pfd_override_throttle(c->u.x11.s, enable);
1958 * Handle the key exchange and user authentication phases.
1960 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
1964 static unsigned char *rsabuf, *keystr1, *keystr2;
1965 unsigned char cookie[8];
1966 struct RSAKey servkey, hostkey;
1967 struct MD5Context md5c;
1968 static unsigned long supported_ciphers_mask, supported_auths_mask;
1969 static int tried_publickey, tried_agent;
1970 static int tis_auth_refused, ccard_auth_refused;
1971 static unsigned char session_id[16];
1972 static int cipher_type;
1973 static char username[100];
1974 static void *publickey_blob;
1975 int publickey_bloblen;
1982 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1983 bombout(("Public key packet not received"));
1987 logevent("Received public keys");
1989 memcpy(cookie, pktin.body, 8);
1991 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
1992 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
1995 * Log the host key fingerprint.
1999 logevent("Host key fingerprint is:");
2000 strcpy(logmsg, " ");
2001 hostkey.comment = NULL;
2002 rsa_fingerprint(logmsg + strlen(logmsg),
2003 sizeof(logmsg) - strlen(logmsg), &hostkey);
2007 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2008 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2009 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
2011 ssh1_local_protoflags =
2012 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2013 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2016 MD5Update(&md5c, keystr2, hostkey.bytes);
2017 MD5Update(&md5c, keystr1, servkey.bytes);
2018 MD5Update(&md5c, pktin.body, 8);
2019 MD5Final(session_id, &md5c);
2021 for (i = 0; i < 32; i++)
2022 session_key[i] = random_byte();
2024 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2026 rsabuf = smalloc(len);
2028 fatalbox("Out of memory");
2031 * Verify the host key.
2035 * First format the key into a string.
2037 int len = rsastr_len(&hostkey);
2038 char fingerprint[100];
2039 char *keystr = smalloc(len);
2041 fatalbox("Out of memory");
2042 rsastr_fmt(keystr, &hostkey);
2043 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2044 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2049 for (i = 0; i < 32; i++) {
2050 rsabuf[i] = session_key[i];
2052 rsabuf[i] ^= session_id[i];
2055 if (hostkey.bytes > servkey.bytes) {
2056 rsaencrypt(rsabuf, 32, &servkey);
2057 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2059 rsaencrypt(rsabuf, 32, &hostkey);
2060 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2063 logevent("Encrypted session key");
2066 int cipher_chosen = 0, warn = 0;
2067 char *cipher_string = NULL;
2068 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2069 int next_cipher = cfg.ssh_cipherlist[i];
2070 if (next_cipher == CIPHER_WARN) {
2071 /* If/when we choose a cipher, warn about it */
2073 } else if (next_cipher == CIPHER_AES) {
2074 /* XXX Probably don't need to mention this. */
2075 logevent("AES not supported in SSH1, skipping");
2077 switch (next_cipher) {
2078 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2079 cipher_string = "3DES"; break;
2080 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2081 cipher_string = "Blowfish"; break;
2082 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2083 cipher_string = "single-DES"; break;
2085 if (supported_ciphers_mask & (1 << cipher_type))
2089 if (!cipher_chosen) {
2090 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2091 bombout(("Server violates SSH 1 protocol by not "
2092 "supporting 3DES encryption"));
2094 /* shouldn't happen */
2095 bombout(("No supported ciphers found"));
2099 /* Warn about chosen cipher if necessary. */
2101 askcipher(cipher_string, 0);
2104 switch (cipher_type) {
2105 case SSH_CIPHER_3DES:
2106 logevent("Using 3DES encryption");
2108 case SSH_CIPHER_DES:
2109 logevent("Using single-DES encryption");
2111 case SSH_CIPHER_BLOWFISH:
2112 logevent("Using Blowfish encryption");
2116 send_packet(SSH1_CMSG_SESSION_KEY,
2117 PKT_CHAR, cipher_type,
2118 PKT_DATA, cookie, 8,
2119 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2120 PKT_DATA, rsabuf, len,
2121 PKT_INT, ssh1_local_protoflags, PKT_END);
2123 logevent("Trying to enable encryption...");
2127 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2128 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
2129 cipher->sesskey(session_key);
2133 if (pktin.type != SSH1_SMSG_SUCCESS) {
2134 bombout(("Encryption not successfully enabled"));
2138 logevent("Successfully started encryption");
2144 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2146 if (!ssh_get_line("login as: ",
2147 username, sizeof(username), FALSE)) {
2149 * get_line failed to get a username.
2152 logevent("No username provided. Abandoning session.");
2153 ssh_state = SSH_STATE_CLOSED;
2157 c_write_str("login as: ");
2160 crWaitUntil(!ispkt);
2162 switch (c = *in++) {
2171 c_write_str("\b \b");
2178 c_write_str("\b \b");
2187 if (((c >= ' ' && c <= '~') ||
2188 ((unsigned char) c >= 160))
2189 && pos < sizeof(username)-1) {
2190 username[pos++] = c;
2196 c_write_str("\r\n");
2197 username[strcspn(username, "\n\r")] = '\0';
2200 strncpy(username, cfg.username, 99);
2201 username[99] = '\0';
2204 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2206 char userlog[22 + sizeof(username)];
2207 sprintf(userlog, "Sent username \"%s\"", username);
2209 if (flags & FLAG_INTERACTIVE &&
2210 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2211 strcat(userlog, "\r\n");
2212 c_write_str(userlog);
2219 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2220 /* We must not attempt PK auth. Pretend we've already tried it. */
2221 tried_publickey = tried_agent = 1;
2223 tried_publickey = tried_agent = 0;
2225 tis_auth_refused = ccard_auth_refused = 0;
2226 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2228 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2229 publickey_blob = NULL;
2231 publickey_blob = NULL;
2233 while (pktin.type == SSH1_SMSG_FAILURE) {
2234 static char password[100];
2235 static char prompt[200];
2238 static int pwpkt_type;
2239 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2241 if (agent_exists() && !tried_agent) {
2243 * Attempt RSA authentication using Pageant.
2245 static unsigned char request[5], *response, *p;
2246 static int responselen;
2247 static int i, nkeys;
2248 static int authed = FALSE;
2252 logevent("Pageant is running. Requesting keys.");
2254 /* Request the keys held by the agent. */
2255 PUT_32BIT(request, 1);
2256 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2257 agent_query(request, 5, &r, &responselen);
2258 response = (unsigned char *) r;
2259 if (response && responselen >= 5 &&
2260 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2262 nkeys = GET_32BIT(p);
2266 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2269 for (i = 0; i < nkeys; i++) {
2270 static struct RSAKey key;
2271 static Bignum challenge;
2272 static char *commentp;
2273 static int commentlen;
2277 sprintf(buf, "Trying Pageant key #%d", i);
2280 if (publickey_blob &&
2281 !memcmp(p, publickey_blob, publickey_bloblen)) {
2282 logevent("This key matches configured key file");
2283 tried_publickey = 1;
2286 p += ssh1_read_bignum(p, &key.exponent);
2287 p += ssh1_read_bignum(p, &key.modulus);
2288 commentlen = GET_32BIT(p);
2292 send_packet(SSH1_CMSG_AUTH_RSA,
2293 PKT_BIGNUM, key.modulus, PKT_END);
2295 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2296 logevent("Key refused");
2299 logevent("Received RSA challenge");
2300 ssh1_read_bignum(pktin.body, &challenge);
2302 char *agentreq, *q, *ret;
2305 len = 1 + 4; /* message type, bit count */
2306 len += ssh1_bignum_length(key.exponent);
2307 len += ssh1_bignum_length(key.modulus);
2308 len += ssh1_bignum_length(challenge);
2309 len += 16; /* session id */
2310 len += 4; /* response format */
2311 agentreq = smalloc(4 + len);
2312 PUT_32BIT(agentreq, len);
2314 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2315 PUT_32BIT(q, bignum_bitcount(key.modulus));
2317 q += ssh1_write_bignum(q, key.exponent);
2318 q += ssh1_write_bignum(q, key.modulus);
2319 q += ssh1_write_bignum(q, challenge);
2320 memcpy(q, session_id, 16);
2322 PUT_32BIT(q, 1); /* response format */
2323 agent_query(agentreq, len + 4, &vret, &retlen);
2327 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2328 logevent("Sending Pageant's response");
2329 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2330 PKT_DATA, ret + 5, 16,
2334 if (pktin.type == SSH1_SMSG_SUCCESS) {
2336 ("Pageant's response accepted");
2337 if (flags & FLAG_VERBOSE) {
2339 ("Authenticated using RSA key \"");
2340 c_write(commentp, commentlen);
2341 c_write_str("\" from agent\r\n");
2346 ("Pageant's response not accepted");
2349 ("Pageant failed to answer challenge");
2353 logevent("No reply received from Pageant");
2356 freebn(key.exponent);
2357 freebn(key.modulus);
2366 if (*cfg.keyfile && !tried_publickey)
2367 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2369 if (cfg.try_tis_auth &&
2370 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2371 !tis_auth_refused) {
2372 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2373 logevent("Requested TIS authentication");
2374 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2376 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2377 logevent("TIS authentication declined");
2378 if (flags & FLAG_INTERACTIVE)
2379 c_write_str("TIS authentication refused.\r\n");
2380 tis_auth_refused = 1;
2383 int challengelen = ((pktin.body[0] << 24) |
2384 (pktin.body[1] << 16) |
2385 (pktin.body[2] << 8) |
2387 logevent("Received TIS challenge");
2388 if (challengelen > sizeof(prompt) - 1)
2389 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2390 memcpy(prompt, pktin.body + 4, challengelen);
2391 /* Prompt heuristic comes from OpenSSH */
2392 strncpy(prompt + challengelen,
2393 memchr(prompt, '\n', challengelen) ?
2394 "": "\r\nResponse: ",
2395 (sizeof prompt) - challengelen);
2396 prompt[(sizeof prompt) - 1] = '\0';
2399 if (cfg.try_tis_auth &&
2400 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2401 !ccard_auth_refused) {
2402 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2403 logevent("Requested CryptoCard authentication");
2404 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2406 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2407 logevent("CryptoCard authentication declined");
2408 c_write_str("CryptoCard authentication refused.\r\n");
2409 ccard_auth_refused = 1;
2412 int challengelen = ((pktin.body[0] << 24) |
2413 (pktin.body[1] << 16) |
2414 (pktin.body[2] << 8) |
2416 logevent("Received CryptoCard challenge");
2417 if (challengelen > sizeof(prompt) - 1)
2418 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2419 memcpy(prompt, pktin.body + 4, challengelen);
2420 strncpy(prompt + challengelen,
2421 memchr(prompt, '\n', challengelen) ?
2422 "" : "\r\nResponse: ",
2423 sizeof(prompt) - challengelen);
2424 prompt[sizeof(prompt) - 1] = '\0';
2427 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2428 sprintf(prompt, "%.90s@%.90s's password: ",
2429 username, savedhost);
2431 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2432 char *comment = NULL;
2433 if (flags & FLAG_VERBOSE)
2434 c_write_str("Trying public key authentication.\r\n");
2435 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2436 if (flags & FLAG_VERBOSE)
2437 c_write_str("No passphrase required.\r\n");
2440 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2445 * Show password prompt, having first obtained it via a TIS
2446 * or CryptoCard exchange if we're doing TIS or CryptoCard
2450 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2452 * get_line failed to get a password (for example
2453 * because one was supplied on the command line
2454 * which has already failed to work). Terminate.
2456 send_packet(SSH1_MSG_DISCONNECT,
2457 PKT_STR, "No more passwords available to try",
2459 logevent("Unable to authenticate");
2460 connection_fatal("Unable to authenticate");
2461 ssh_state = SSH_STATE_CLOSED;
2465 /* Prompt may have come from server. We've munged it a bit, so
2466 * we know it to be zero-terminated at least once. */
2467 c_write_untrusted(prompt, strlen(prompt));
2471 crWaitUntil(!ispkt);
2473 switch (c = *in++) {
2493 if (pos < sizeof(password)-1)
2494 password[pos++] = c;
2498 c_write_str("\r\n");
2502 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2504 * Try public key authentication with the specified
2507 static struct RSAKey pubkey;
2508 static Bignum challenge, response;
2510 static unsigned char buffer[32];
2512 tried_publickey = 1;
2513 i = loadrsakey(cfg.keyfile, &pubkey, password);
2515 c_write_str("Couldn't load private key from ");
2516 c_write_str(cfg.keyfile);
2517 c_write_str(".\r\n");
2518 continue; /* go and try password */
2521 c_write_str("Wrong passphrase.\r\n");
2522 tried_publickey = 0;
2523 continue; /* try again */
2527 * Send a public key attempt.
2529 send_packet(SSH1_CMSG_AUTH_RSA,
2530 PKT_BIGNUM, pubkey.modulus, PKT_END);
2533 if (pktin.type == SSH1_SMSG_FAILURE) {
2534 c_write_str("Server refused our public key.\r\n");
2535 continue; /* go and try password */
2537 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2538 bombout(("Bizarre response to offer of public key"));
2541 ssh1_read_bignum(pktin.body, &challenge);
2542 response = rsadecrypt(challenge, &pubkey);
2543 freebn(pubkey.private_exponent); /* burn the evidence */
2545 for (i = 0; i < 32; i++) {
2546 buffer[i] = bignum_byte(response, 31 - i);
2550 MD5Update(&md5c, buffer, 32);
2551 MD5Update(&md5c, session_id, 16);
2552 MD5Final(buffer, &md5c);
2554 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2555 PKT_DATA, buffer, 16, PKT_END);
2558 if (pktin.type == SSH1_SMSG_FAILURE) {
2559 if (flags & FLAG_VERBOSE)
2561 ("Failed to authenticate with our public key.\r\n");
2562 continue; /* go and try password */
2563 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2565 ("Bizarre response to RSA authentication response"));
2569 break; /* we're through! */
2571 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2573 * Defence against traffic analysis: we send a
2574 * whole bunch of packets containing strings of
2575 * different lengths. One of these strings is the
2576 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2577 * The others are all random data in
2578 * SSH1_MSG_IGNORE packets. This way a passive
2579 * listener can't tell which is the password, and
2580 * hence can't deduce the password length.
2582 * Anybody with a password length greater than 16
2583 * bytes is going to have enough entropy in their
2584 * password that a listener won't find it _that_
2585 * much help to know how long it is. So what we'll
2588 * - if password length < 16, we send 15 packets
2589 * containing string lengths 1 through 15
2591 * - otherwise, we let N be the nearest multiple
2592 * of 8 below the password length, and send 8
2593 * packets containing string lengths N through
2594 * N+7. This won't obscure the order of
2595 * magnitude of the password length, but it will
2596 * introduce a bit of extra uncertainty.
2598 * A few servers (the old 1.2.18 through 1.2.22)
2599 * can't deal with SSH1_MSG_IGNORE. For these
2600 * servers, we need an alternative defence. We make
2601 * use of the fact that the password is interpreted
2602 * as a C string: so we can append a NUL, then some
2605 * One server (a Cisco one) can deal with neither
2606 * SSH1_MSG_IGNORE _nor_ a padded password string.
2607 * For this server we are left with no defences
2608 * against password length sniffing.
2610 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2612 * The server can deal with SSH1_MSG_IGNORE, so
2613 * we can use the primary defence.
2615 int bottom, top, pwlen, i;
2618 pwlen = strlen(password);
2620 bottom = 0; /* zero length passwords are OK! :-) */
2623 bottom = pwlen & ~7;
2627 assert(pwlen >= bottom && pwlen <= top);
2629 randomstr = smalloc(top + 1);
2631 for (i = bottom; i <= top; i++) {
2633 defer_packet(pwpkt_type, PKT_STR, password,
2636 for (j = 0; j < i; j++) {
2638 randomstr[j] = random_byte();
2639 } while (randomstr[j] == '\0');
2641 randomstr[i] = '\0';
2642 defer_packet(SSH1_MSG_IGNORE,
2643 PKT_STR, randomstr, PKT_END);
2646 logevent("Sending password with camouflage packets");
2647 ssh_pkt_defersend();
2649 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2651 * The server can't deal with SSH1_MSG_IGNORE
2652 * but can deal with padded passwords, so we
2653 * can use the secondary defence.
2659 len = strlen(password);
2660 if (len < sizeof(string)) {
2662 strcpy(string, password);
2663 len++; /* cover the zero byte */
2664 while (len < sizeof(string)) {
2665 string[len++] = (char) random_byte();
2670 logevent("Sending length-padded password");
2671 send_packet(pwpkt_type, PKT_INT, len,
2672 PKT_DATA, s, len, PKT_END);
2675 * The server has _both_
2676 * BUG_CHOKES_ON_SSH1_IGNORE and
2677 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2678 * therefore nothing we can do.
2681 len = strlen(password);
2682 logevent("Sending unpadded password");
2683 send_packet(pwpkt_type, PKT_INT, len,
2684 PKT_DATA, password, len, PKT_END);
2687 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2690 logevent("Sent password");
2691 memset(password, 0, strlen(password));
2693 if (pktin.type == SSH1_SMSG_FAILURE) {
2694 if (flags & FLAG_VERBOSE)
2695 c_write_str("Access denied\r\n");
2696 logevent("Authentication refused");
2697 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2698 logevent("Received disconnect request");
2699 ssh_state = SSH_STATE_CLOSED;
2701 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2702 bombout(("Strange packet received, type %d", pktin.type));
2707 logevent("Authentication successful");
2712 void sshfwd_close(struct ssh_channel *c)
2714 if (c && !c->closes) {
2716 * If the channel's remoteid is -1, we have sent
2717 * CHANNEL_OPEN for this channel, but it hasn't even been
2718 * acknowledged by the server. So we must set a close flag
2719 * on it now, and then when the server acks the channel
2720 * open, we can close it then.
2722 if (c->remoteid != -1) {
2723 if (ssh_version == 1) {
2724 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2727 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2728 ssh2_pkt_adduint32(c->remoteid);
2733 if (c->type == CHAN_X11) {
2735 logevent("Forwarded X11 connection terminated");
2736 } else if (c->type == CHAN_SOCKDATA ||
2737 c->type == CHAN_SOCKDATA_DORMANT) {
2739 logevent("Forwarded port closed");
2744 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2746 if (ssh_version == 1) {
2747 send_packet(SSH1_MSG_CHANNEL_DATA,
2748 PKT_INT, c->remoteid,
2749 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2751 * In SSH1 we can return 0 here - implying that forwarded
2752 * connections are never individually throttled - because
2753 * the only circumstance that can cause throttling will be
2754 * the whole SSH connection backing up, in which case
2755 * _everything_ will be throttled as a whole.
2759 ssh2_add_channel_data(c, buf, len);
2760 return ssh2_try_send(c);
2764 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2766 if (ssh_version == 1) {
2767 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2768 c->v.v1.throttling = 0;
2772 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2776 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2782 while (!do_ssh1_login(in, inlen, ispkt)) {
2785 if (ssh_state == SSH_STATE_CLOSED)
2788 if (cfg.agentfwd && agent_exists()) {
2789 logevent("Requesting agent forwarding");
2790 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2794 if (pktin.type != SSH1_SMSG_SUCCESS
2795 && pktin.type != SSH1_SMSG_FAILURE) {
2796 bombout(("Protocol confusion"));
2798 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2799 logevent("Agent forwarding refused");
2801 logevent("Agent forwarding enabled");
2802 ssh_agentfwd_enabled = TRUE;
2806 if (cfg.x11_forward) {
2807 char proto[20], data[64];
2808 logevent("Requesting X11 forwarding");
2809 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2810 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2811 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2812 PKT_STR, proto, PKT_STR, data,
2813 PKT_INT, 0, PKT_END);
2815 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2816 PKT_STR, proto, PKT_STR, data, PKT_END);
2821 if (pktin.type != SSH1_SMSG_SUCCESS
2822 && pktin.type != SSH1_SMSG_FAILURE) {
2823 bombout(("Protocol confusion"));
2825 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2826 logevent("X11 forwarding refused");
2828 logevent("X11 forwarding enabled");
2829 ssh_X11_fwd_enabled = TRUE;
2837 int sport,dport,sserv,dserv;
2838 char sports[256], dports[256], host[256];
2842 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2843 /* Add port forwardings. */
2848 while (*e && *e != '\t')
2854 while (*e && *e != ':')
2864 dport = atoi(dports);
2868 se = getservbyname(dports, NULL);
2870 dport = ntohs(se->s_port);
2873 "Service lookup failed for destination port \"%s\"",
2878 sport = atoi(sports);
2882 se = getservbyname(sports, NULL);
2884 sport = ntohs(se->s_port);
2887 "Service lookup failed for source port \"%s\"",
2892 if (sport && dport) {
2894 pfd_addforward(host, dport, sport);
2895 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
2896 " %s:%.*s%.*s%d%.*s",
2897 sserv ? strlen(sports) : 0, sports,
2898 sserv, "(", sport, sserv, ")",
2900 dserv ? strlen(dports) : 0, dports,
2901 dserv, "(", dport, dserv, ")");
2904 struct ssh_rportfwd *pf;
2905 pf = smalloc(sizeof(*pf));
2906 strcpy(pf->dhost, host);
2908 if (add234(ssh_rportfwds, pf) != pf) {
2910 "Duplicate remote port forwarding to %s:%d",
2915 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
2916 " forward to %s:%.*s%.*s%d%.*s",
2917 sserv ? strlen(sports) : 0, sports,
2918 sserv, "(", sport, sserv, ")",
2920 dserv ? strlen(dports) : 0, dports,
2921 dserv, "(", dport, dserv, ")");
2923 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
2931 if (pktin.type != SSH1_SMSG_SUCCESS
2932 && pktin.type != SSH1_SMSG_FAILURE) {
2933 bombout(("Protocol confusion"));
2935 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2936 c_write_str("Server refused port forwarding\r\n");
2937 ssh_editing = ssh_echoing = 1;
2939 logevent("Remote port forwarding enabled");
2947 send_packet(SSH1_CMSG_REQUEST_PTY,
2948 PKT_STR, cfg.termtype,
2949 PKT_INT, rows, PKT_INT, cols,
2950 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
2951 ssh_state = SSH_STATE_INTERMED;
2955 if (pktin.type != SSH1_SMSG_SUCCESS
2956 && pktin.type != SSH1_SMSG_FAILURE) {
2957 bombout(("Protocol confusion"));
2959 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2960 c_write_str("Server refused to allocate pty\r\n");
2961 ssh_editing = ssh_echoing = 1;
2963 logevent("Allocated pty");
2965 ssh_editing = ssh_echoing = 1;
2968 if (cfg.compression) {
2969 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
2973 if (pktin.type != SSH1_SMSG_SUCCESS
2974 && pktin.type != SSH1_SMSG_FAILURE) {
2975 bombout(("Protocol confusion"));
2977 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2978 c_write_str("Server refused to compress\r\n");
2980 logevent("Started compression");
2981 ssh1_compressing = TRUE;
2982 zlib_compress_init();
2983 zlib_decompress_init();
2987 * Start the shell or command.
2989 * Special case: if the first-choice command is an SSH2
2990 * subsystem (hence not usable here) and the second choice
2991 * exists, we fall straight back to that.
2994 char *cmd = cfg.remote_cmd_ptr;
2996 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
2997 cmd = cfg.remote_cmd_ptr2;
2998 ssh_fallback_cmd = TRUE;
3001 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3003 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3004 logevent("Started session");
3007 ssh_state = SSH_STATE_SESSION;
3011 ssh_special(TS_EOF);
3013 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
3015 ssh_channels = newtree234(ssh_channelcmp);
3019 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
3020 pktin.type == SSH1_SMSG_STDERR_DATA) {
3021 long len = GET_32BIT(pktin.body);
3023 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3024 pktin.body + 4, len);
3025 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3026 ssh1_stdout_throttling = 1;
3029 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
3030 ssh_state = SSH_STATE_CLOSED;
3031 logevent("Received disconnect request");
3033 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3034 /* Remote side is trying to open a channel to talk to our
3035 * X-Server. Give them back a local channel number. */
3036 struct ssh_channel *c;
3038 logevent("Received X11 connect request");
3039 /* Refuse if X11 forwarding is disabled. */
3040 if (!ssh_X11_fwd_enabled) {
3041 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3042 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3043 logevent("Rejected X11 connect request");
3045 c = smalloc(sizeof(struct ssh_channel));
3047 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3048 logevent("opening X11 forward connection failed");
3050 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3051 PKT_INT, GET_32BIT(pktin.body),
3055 ("opening X11 forward connection succeeded");
3056 c->remoteid = GET_32BIT(pktin.body);
3057 c->localid = alloc_channel_id();
3059 c->v.v1.throttling = 0;
3060 c->type = CHAN_X11; /* identify channel type */
3061 add234(ssh_channels, c);
3062 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3063 PKT_INT, c->remoteid, PKT_INT,
3064 c->localid, PKT_END);
3065 logevent("Opened X11 forward channel");
3068 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3069 /* Remote side is trying to open a channel to talk to our
3070 * agent. Give them back a local channel number. */
3071 struct ssh_channel *c;
3073 /* Refuse if agent forwarding is disabled. */
3074 if (!ssh_agentfwd_enabled) {
3075 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3076 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3078 c = smalloc(sizeof(struct ssh_channel));
3079 c->remoteid = GET_32BIT(pktin.body);
3080 c->localid = alloc_channel_id();
3082 c->v.v1.throttling = 0;
3083 c->type = CHAN_AGENT; /* identify channel type */
3084 c->u.a.lensofar = 0;
3085 add234(ssh_channels, c);
3086 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3087 PKT_INT, c->remoteid, PKT_INT, c->localid,
3090 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3091 /* Remote side is trying to open a channel to talk to a
3092 * forwarded port. Give them back a local channel number. */
3093 struct ssh_channel *c;
3094 struct ssh_rportfwd pf;
3096 char host[256], buf[1024];
3098 c = smalloc(sizeof(struct ssh_channel));
3100 hostsize = GET_32BIT(pktin.body+4);
3101 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3102 if (h+1 < host+sizeof(host))
3107 port = GET_32BIT(p);
3109 strcpy(pf.dhost, host);
3112 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3113 sprintf(buf, "Rejected remote port open request for %s:%d",
3116 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3117 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3119 sprintf(buf, "Received remote port open request for %s:%d",
3122 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3125 sprintf(buf, "Port open failed: %s", e);
3128 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3129 PKT_INT, GET_32BIT(pktin.body),
3132 c->remoteid = GET_32BIT(pktin.body);
3133 c->localid = alloc_channel_id();
3135 c->v.v1.throttling = 0;
3136 c->type = CHAN_SOCKDATA; /* identify channel type */
3137 add234(ssh_channels, c);
3138 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3139 PKT_INT, c->remoteid, PKT_INT,
3140 c->localid, PKT_END);
3141 logevent("Forwarded port opened successfully");
3145 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3146 unsigned int remoteid = GET_32BIT(pktin.body);
3147 unsigned int localid = GET_32BIT(pktin.body+4);
3148 struct ssh_channel *c;
3150 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3151 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3152 c->remoteid = localid;
3153 c->type = CHAN_SOCKDATA;
3154 c->v.v1.throttling = 0;
3155 pfd_confirm(c->u.pfd.s);
3158 if (c && c->closes) {
3160 * We have a pending close on this channel,
3161 * which we decided on before the server acked
3162 * the channel open. So now we know the
3163 * remoteid, we can close it again.
3165 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3169 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3170 unsigned int remoteid = GET_32BIT(pktin.body);
3171 unsigned int localid = GET_32BIT(pktin.body+4);
3172 struct ssh_channel *c;
3174 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3175 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3176 logevent("Forwarded connection refused by server");
3177 pfd_close(c->u.pfd.s);
3178 del234(ssh_channels, c);
3182 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3183 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3184 /* Remote side closes a channel. */
3185 unsigned i = GET_32BIT(pktin.body);
3186 struct ssh_channel *c;
3187 c = find234(ssh_channels, &i, ssh_channelfind);
3191 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3192 if (!(c->closes & closetype))
3193 send_packet(pktin.type, PKT_INT, c->remoteid,
3195 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3196 logevent("Forwarded X11 connection terminated");
3197 assert(c->u.x11.s != NULL);
3198 x11_close(c->u.x11.s);
3201 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3202 logevent("Forwarded port closed");
3203 assert(c->u.pfd.s != NULL);
3204 pfd_close(c->u.pfd.s);
3207 c->closes |= closetype;
3208 if (c->closes == 3) {
3209 del234(ssh_channels, c);
3213 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3214 /* Data sent down one of our channels. */
3215 int i = GET_32BIT(pktin.body);
3216 int len = GET_32BIT(pktin.body + 4);
3217 unsigned char *p = pktin.body + 8;
3218 struct ssh_channel *c;
3219 c = find234(ssh_channels, &i, ssh_channelfind);
3224 bufsize = x11_send(c->u.x11.s, p, len);
3227 bufsize = pfd_send(c->u.pfd.s, p, len);
3230 /* Data for an agent message. Buffer it. */
3232 if (c->u.a.lensofar < 4) {
3233 int l = min(4 - c->u.a.lensofar, len);
3234 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3238 c->u.a.lensofar += l;
3240 if (c->u.a.lensofar == 4) {
3242 4 + GET_32BIT(c->u.a.msglen);
3243 c->u.a.message = smalloc(c->u.a.totallen);
3244 memcpy(c->u.a.message, c->u.a.msglen, 4);
3246 if (c->u.a.lensofar >= 4 && len > 0) {
3248 min(c->u.a.totallen - c->u.a.lensofar,
3250 memcpy(c->u.a.message + c->u.a.lensofar, p,
3254 c->u.a.lensofar += l;
3256 if (c->u.a.lensofar == c->u.a.totallen) {
3257 void *reply, *sentreply;
3259 agent_query(c->u.a.message,
3260 c->u.a.totallen, &reply,
3265 /* Fake SSH_AGENT_FAILURE. */
3266 sentreply = "\0\0\0\1\5";
3269 send_packet(SSH1_MSG_CHANNEL_DATA,
3270 PKT_INT, c->remoteid,
3272 PKT_DATA, sentreply, replylen,
3276 sfree(c->u.a.message);
3277 c->u.a.lensofar = 0;
3280 bufsize = 0; /* agent channels never back up */
3283 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3284 c->v.v1.throttling = 1;
3288 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3289 /* may be from EXEC_SHELL on some servers */
3290 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3291 /* may be from EXEC_SHELL on some servers
3292 * if no pty is available or in other odd cases. Ignore */
3293 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3295 ssh_exitcode = GET_32BIT(pktin.body);
3296 sprintf(buf, "Server sent command exit status %d",
3299 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3301 * In case `helpful' firewalls or proxies tack
3302 * extra human-readable text on the end of the
3303 * session which we might mistake for another
3304 * encrypted packet, we close the session once
3305 * we've sent EXIT_CONFIRMATION.
3307 ssh_state = SSH_STATE_CLOSED;
3310 bombout(("Strange packet received: type %d", pktin.type));
3315 int len = min(inlen, 512);
3316 send_packet(SSH1_CMSG_STDIN_DATA,
3317 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3328 * Utility routine for decoding comma-separated strings in KEXINIT.
3330 static int in_commasep_string(char *needle, char *haystack, int haylen)
3332 int needlen = strlen(needle);
3335 * Is it at the start of the string?
3337 if (haylen >= needlen && /* haystack is long enough */
3338 !memcmp(needle, haystack, needlen) && /* initial match */
3339 (haylen == needlen || haystack[needlen] == ',')
3340 /* either , or EOS follows */
3344 * If not, search for the next comma and resume after that.
3345 * If no comma found, terminate.
3347 while (haylen > 0 && *haystack != ',')
3348 haylen--, haystack++;
3351 haylen--, haystack++; /* skip over comma itself */
3356 * SSH2 key creation method.
3358 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3362 /* First 20 bytes. */
3365 SHA_Bytes(&s, H, 20);
3366 SHA_Bytes(&s, &chr, 1);
3367 SHA_Bytes(&s, sessid, 20);
3368 SHA_Final(&s, keyspace);
3369 /* Next 20 bytes. */
3372 SHA_Bytes(&s, H, 20);
3373 SHA_Bytes(&s, keyspace, 20);
3374 SHA_Final(&s, keyspace + 20);
3378 * Handle the SSH2 transport layer.
3380 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3382 static int i, j, len, nbits, pbits, warn;
3384 static Bignum p, g, e, f, K;
3385 static int kex_init_value, kex_reply_value;
3386 static const struct ssh_mac **maclist;
3388 static const struct ssh2_cipher *cscipher_tobe = NULL;
3389 static const struct ssh2_cipher *sccipher_tobe = NULL;
3390 static const struct ssh_mac *csmac_tobe = NULL;
3391 static const struct ssh_mac *scmac_tobe = NULL;
3392 static const struct ssh_compress *cscomp_tobe = NULL;
3393 static const struct ssh_compress *sccomp_tobe = NULL;
3394 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3395 static int hostkeylen, siglen;
3396 static void *hkey; /* actual host key */
3397 static unsigned char exchange_hash[20];
3398 static unsigned char keyspace[40];
3399 static int n_preferred_ciphers;
3400 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3401 static const struct ssh_compress *preferred_comp;
3402 static int cipherstr_started;
3403 static int first_kex;
3410 * Set up the preferred ciphers. (NULL => warn below here)
3412 n_preferred_ciphers = 0;
3413 for (i = 0; i < CIPHER_MAX; i++) {
3414 switch (cfg.ssh_cipherlist[i]) {
3415 case CIPHER_BLOWFISH:
3416 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3417 n_preferred_ciphers++;
3420 if (cfg.ssh2_des_cbc) {
3421 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3422 n_preferred_ciphers++;
3426 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3427 n_preferred_ciphers++;
3430 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3431 n_preferred_ciphers++;
3434 /* Flag for later. Don't bother if it's the last in
3436 if (i < CIPHER_MAX - 1) {
3437 preferred_ciphers[n_preferred_ciphers] = NULL;
3438 n_preferred_ciphers++;
3445 * Set up preferred compression.
3447 if (cfg.compression)
3448 preferred_comp = &ssh_zlib;
3450 preferred_comp = &ssh_comp_none;
3453 * Be prepared to work around the buggy MAC problem.
3455 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3456 maclist = buggymacs, nmacs = lenof(buggymacs);
3458 maclist = macs, nmacs = lenof(macs);
3462 * Construct and send our key exchange packet.
3464 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3465 for (i = 0; i < 16; i++)
3466 ssh2_pkt_addbyte((unsigned char) random_byte());
3467 /* List key exchange algorithms. */
3468 ssh2_pkt_addstring_start();
3469 for (i = 0; i < lenof(kex_algs); i++) {
3470 ssh2_pkt_addstring_str(kex_algs[i]->name);
3471 if (i < lenof(kex_algs) - 1)
3472 ssh2_pkt_addstring_str(",");
3474 /* List server host key algorithms. */
3475 ssh2_pkt_addstring_start();
3476 for (i = 0; i < lenof(hostkey_algs); i++) {
3477 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3478 if (i < lenof(hostkey_algs) - 1)
3479 ssh2_pkt_addstring_str(",");
3481 /* List client->server encryption algorithms. */
3482 ssh2_pkt_addstring_start();
3483 cipherstr_started = 0;
3484 for (i = 0; i < n_preferred_ciphers; i++) {
3485 const struct ssh2_ciphers *c = preferred_ciphers[i];
3486 if (!c) continue; /* warning flag */
3487 for (j = 0; j < c->nciphers; j++) {
3488 if (cipherstr_started)
3489 ssh2_pkt_addstring_str(",");
3490 ssh2_pkt_addstring_str(c->list[j]->name);
3491 cipherstr_started = 1;
3494 /* List server->client encryption algorithms. */
3495 ssh2_pkt_addstring_start();
3496 cipherstr_started = 0;
3497 for (i = 0; i < n_preferred_ciphers; i++) {
3498 const struct ssh2_ciphers *c = preferred_ciphers[i];
3499 if (!c) continue; /* warning flag */
3500 for (j = 0; j < c->nciphers; j++) {
3501 if (cipherstr_started)
3502 ssh2_pkt_addstring_str(",");
3503 ssh2_pkt_addstring_str(c->list[j]->name);
3504 cipherstr_started = 1;
3507 /* List client->server MAC algorithms. */
3508 ssh2_pkt_addstring_start();
3509 for (i = 0; i < nmacs; i++) {
3510 ssh2_pkt_addstring_str(maclist[i]->name);
3512 ssh2_pkt_addstring_str(",");
3514 /* List server->client MAC algorithms. */
3515 ssh2_pkt_addstring_start();
3516 for (i = 0; i < nmacs; i++) {
3517 ssh2_pkt_addstring_str(maclist[i]->name);
3519 ssh2_pkt_addstring_str(",");
3521 /* List client->server compression algorithms. */
3522 ssh2_pkt_addstring_start();
3523 for (i = 0; i < lenof(compressions) + 1; i++) {
3524 const struct ssh_compress *c =
3525 i == 0 ? preferred_comp : compressions[i - 1];
3526 ssh2_pkt_addstring_str(c->name);
3527 if (i < lenof(compressions))
3528 ssh2_pkt_addstring_str(",");
3530 /* List server->client compression algorithms. */
3531 ssh2_pkt_addstring_start();
3532 for (i = 0; i < lenof(compressions) + 1; i++) {
3533 const struct ssh_compress *c =
3534 i == 0 ? preferred_comp : compressions[i - 1];
3535 ssh2_pkt_addstring_str(c->name);
3536 if (i < lenof(compressions))
3537 ssh2_pkt_addstring_str(",");
3539 /* List client->server languages. Empty list. */
3540 ssh2_pkt_addstring_start();
3541 /* List server->client languages. Empty list. */
3542 ssh2_pkt_addstring_start();
3543 /* First KEX packet does _not_ follow, because we're not that brave. */
3544 ssh2_pkt_addbool(FALSE);
3546 ssh2_pkt_adduint32(0);
3548 exhash = exhashbase;
3549 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3555 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3558 * Now examine the other side's KEXINIT to see what we're up
3561 if (pktin.type != SSH2_MSG_KEXINIT) {
3562 bombout(("expected key exchange packet from server"));
3567 cscipher_tobe = NULL;
3568 sccipher_tobe = NULL;
3573 pktin.savedpos += 16; /* skip garbage cookie */
3574 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3575 for (i = 0; i < lenof(kex_algs); i++) {
3576 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3581 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3582 for (i = 0; i < lenof(hostkey_algs); i++) {
3583 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3584 hostkey = hostkey_algs[i];
3588 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3590 for (i = 0; i < n_preferred_ciphers; i++) {
3591 const struct ssh2_ciphers *c = preferred_ciphers[i];
3595 for (j = 0; j < c->nciphers; j++) {
3596 if (in_commasep_string(c->list[j]->name, str, len)) {
3597 cscipher_tobe = c->list[j];
3602 if (cscipher_tobe) {
3604 askcipher(cscipher_tobe->name, 1);
3608 if (!cscipher_tobe) {
3609 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3613 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3615 for (i = 0; i < n_preferred_ciphers; i++) {
3616 const struct ssh2_ciphers *c = preferred_ciphers[i];
3620 for (j = 0; j < c->nciphers; j++) {
3621 if (in_commasep_string(c->list[j]->name, str, len)) {
3622 sccipher_tobe = c->list[j];
3627 if (sccipher_tobe) {
3629 askcipher(sccipher_tobe->name, 2);
3633 if (!sccipher_tobe) {
3634 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3638 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3639 for (i = 0; i < nmacs; i++) {
3640 if (in_commasep_string(maclist[i]->name, str, len)) {
3641 csmac_tobe = maclist[i];
3645 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3646 for (i = 0; i < nmacs; i++) {
3647 if (in_commasep_string(maclist[i]->name, str, len)) {
3648 scmac_tobe = maclist[i];
3652 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3653 for (i = 0; i < lenof(compressions) + 1; i++) {
3654 const struct ssh_compress *c =
3655 i == 0 ? preferred_comp : compressions[i - 1];
3656 if (in_commasep_string(c->name, str, len)) {
3661 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3662 for (i = 0; i < lenof(compressions) + 1; i++) {
3663 const struct ssh_compress *c =
3664 i == 0 ? preferred_comp : compressions[i - 1];
3665 if (in_commasep_string(c->name, str, len)) {
3672 * Work out the number of bits of key we will need from the key
3673 * exchange. We start with the maximum key length of either
3679 csbits = cscipher_tobe->keylen;
3680 scbits = sccipher_tobe->keylen;
3681 nbits = (csbits > scbits ? csbits : scbits);
3683 /* The keys only have 160-bit entropy, since they're based on
3684 * a SHA-1 hash. So cap the key size at 160 bits. */
3689 * If we're doing Diffie-Hellman group exchange, start by
3690 * requesting a group.
3692 if (kex == &ssh_diffiehellman_gex) {
3693 logevent("Doing Diffie-Hellman group exchange");
3694 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
3696 * Work out how big a DH group we will need to allow that
3699 pbits = 512 << ((nbits - 1) / 64);
3700 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3701 ssh2_pkt_adduint32(pbits);
3705 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3706 bombout(("expected key exchange group packet from server"));
3709 p = ssh2_pkt_getmp();
3710 g = ssh2_pkt_getmp();
3711 dh_setup_group(p, g);
3712 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3713 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3715 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3717 kex_init_value = SSH2_MSG_KEXDH_INIT;
3718 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3721 logevent("Doing Diffie-Hellman key exchange");
3723 * Now generate and send e for Diffie-Hellman.
3725 e = dh_create_e(nbits * 2);
3726 ssh2_pkt_init(kex_init_value);
3731 if (pktin.type != kex_reply_value) {
3732 bombout(("expected key exchange reply packet from server"));
3735 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3736 f = ssh2_pkt_getmp();
3737 ssh2_pkt_getstring(&sigdata, &siglen);
3741 sha_string(&exhash, hostkeydata, hostkeylen);
3742 if (kex == &ssh_diffiehellman_gex) {
3743 sha_uint32(&exhash, pbits);
3744 sha_mpint(&exhash, p);
3745 sha_mpint(&exhash, g);
3747 sha_mpint(&exhash, e);
3748 sha_mpint(&exhash, f);
3749 sha_mpint(&exhash, K);
3750 SHA_Final(&exhash, exchange_hash);
3755 debug(("Exchange hash is:\n"));
3756 dmemdump(exchange_hash, 20);
3759 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3761 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3762 bombout(("Server's host key did not match the signature supplied"));
3767 * Authenticate remote host: verify host key. (We've already
3768 * checked the signature of the exchange hash.)
3770 keystr = hostkey->fmtkey(hkey);
3771 fingerprint = hostkey->fingerprint(hkey);
3772 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3773 keystr, fingerprint);
3774 if (first_kex) { /* don't bother logging this in rekeys */
3775 logevent("Host key fingerprint is:");
3776 logevent(fingerprint);
3780 hostkey->freekey(hkey);
3783 * Send SSH2_MSG_NEWKEYS.
3785 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3789 * Expect SSH2_MSG_NEWKEYS from server.
3792 if (pktin.type != SSH2_MSG_NEWKEYS) {
3793 bombout(("expected new-keys packet from server"));
3798 * Create and initialise session keys.
3800 cscipher = cscipher_tobe;
3801 sccipher = sccipher_tobe;
3804 cscomp = cscomp_tobe;
3805 sccomp = sccomp_tobe;
3806 cscomp->compress_init();
3807 sccomp->decompress_init();
3809 * Set IVs after keys. Here we use the exchange hash from the
3810 * _first_ key exchange.
3813 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3814 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3815 cscipher->setcskey(keyspace);
3816 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3817 sccipher->setsckey(keyspace);
3818 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3819 cscipher->setcsiv(keyspace);
3820 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3821 sccipher->setsciv(keyspace);
3822 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3823 csmac->setcskey(keyspace);
3824 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3825 scmac->setsckey(keyspace);
3828 * If this is the first key exchange phase, we must pass the
3829 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3830 * wants to see it but because it will need time to initialise
3831 * itself before it sees an actual packet. In subsequent key
3832 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3833 * it would only confuse the layer above.
3841 * Now we're encrypting. Begin returning 1 to the protocol main
3842 * function so that other things can run on top of the
3843 * transport. If we ever see a KEXINIT, we must go back to the
3846 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3849 logevent("Server initiated key re-exchange");
3850 goto begin_key_exchange;
3856 * Add data to an SSH2 channel output buffer.
3858 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3861 bufchain_add(&c->v.v2.outbuffer, buf, len);
3865 * Attempt to send data on an SSH2 channel.
3867 static int ssh2_try_send(struct ssh_channel *c)
3869 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3872 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3873 if ((unsigned)len > c->v.v2.remwindow)
3874 len = c->v.v2.remwindow;
3875 if ((unsigned)len > c->v.v2.remmaxpkt)
3876 len = c->v.v2.remmaxpkt;
3877 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3878 ssh2_pkt_adduint32(c->remoteid);
3879 ssh2_pkt_addstring_start();
3880 ssh2_pkt_addstring_data(data, len);
3882 bufchain_consume(&c->v.v2.outbuffer, len);
3883 c->v.v2.remwindow -= len;
3887 * After having sent as much data as we can, return the amount
3890 return bufchain_size(&c->v.v2.outbuffer);
3894 * Potentially enlarge the window on an SSH2 channel.
3896 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3899 * Never send WINDOW_ADJUST for a channel that the remote side
3900 * already thinks it's closed; there's no point, since it won't
3901 * be sending any more data anyway.
3906 if (newwin > c->v.v2.locwindow) {
3907 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
3908 ssh2_pkt_adduint32(c->remoteid);
3909 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
3911 c->v.v2.locwindow = newwin;
3916 * Handle the SSH2 userauth and connection layers.
3918 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
3921 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
3923 AUTH_KEYBOARD_INTERACTIVE
3927 AUTH_TYPE_PUBLICKEY,
3928 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
3929 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
3931 AUTH_TYPE_KEYBOARD_INTERACTIVE,
3932 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3934 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
3935 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
3936 static int kbd_inter_running;
3937 static int we_are_in;
3938 static int num_prompts, echo;
3939 static char username[100];
3940 static int got_username;
3941 static char pwprompt[200];
3942 static char password[100];
3943 static void *publickey_blob;
3944 static int publickey_bloblen;
3949 * Request userauth protocol, and await a response to it.
3951 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
3952 ssh2_pkt_addstring("ssh-userauth");
3954 crWaitUntilV(ispkt);
3955 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
3956 bombout(("Server refused user authentication protocol"));
3961 * We repeat this whole loop, including the username prompt,
3962 * until we manage a successful authentication. If the user
3963 * types the wrong _password_, they are sent back to the
3964 * beginning to try another username. (If they specify a
3965 * username in the config, they are never asked, even if they
3966 * do give a wrong password.)
3968 * I think this best serves the needs of
3970 * - the people who have no configuration, no keys, and just
3971 * want to try repeated (username,password) pairs until they
3972 * type both correctly
3974 * - people who have keys and configuration but occasionally
3975 * need to fall back to passwords
3977 * - people with a key held in Pageant, who might not have
3978 * logged in to a particular machine before; so they want to
3979 * type a username, and then _either_ their key will be
3980 * accepted, _or_ they will type a password. If they mistype
3981 * the username they will want to be able to get back and
3985 got_username = FALSE;
3994 if (got_username && !cfg.change_username) {
3996 * We got a username last time round this loop, and
3997 * with change_username turned off we don't try to get
4000 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4002 if (!ssh_get_line("login as: ",
4003 username, sizeof(username), FALSE)) {
4005 * get_line failed to get a username.
4008 logevent("No username provided. Abandoning session.");
4009 ssh_state = SSH_STATE_CLOSED;
4013 c_write_str("login as: ");
4016 crWaitUntilV(!ispkt);
4018 switch (c = *in++) {
4027 c_write_str("\b \b");
4034 c_write_str("\b \b");
4043 if (((c >= ' ' && c <= '~') ||
4044 ((unsigned char) c >= 160))
4045 && pos < sizeof(username)-1) {
4046 username[pos++] = c;
4053 c_write_str("\r\n");
4054 username[strcspn(username, "\n\r")] = '\0';
4057 strncpy(username, cfg.username, 99);
4058 username[99] = '\0';
4059 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4060 sprintf(stuff, "Using username \"%s\".\r\n", username);
4064 got_username = TRUE;
4067 * Send an authentication request using method "none": (a)
4068 * just in case it succeeds, and (b) so that we know what
4069 * authentication methods we can usefully try next.
4071 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4073 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4074 ssh2_pkt_addstring(username);
4075 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4076 ssh2_pkt_addstring("none"); /* method */
4078 type = AUTH_TYPE_NONE;
4082 tried_pubkey_config = FALSE;
4083 tried_agent = FALSE;
4084 tried_keyb_inter = FALSE;
4085 kbd_inter_running = FALSE;
4086 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4088 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4089 &publickey_bloblen);
4091 publickey_blob = NULL;
4095 * Wait for the result of the last authentication request.
4098 crWaitUntilV(ispkt);
4099 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4103 * Don't show the banner if we're operating in
4104 * non-verbose non-interactive mode. (It's probably
4105 * a script, which means nobody will read the
4106 * banner _anyway_, and moreover the printing of
4107 * the banner will screw up processing on the
4108 * output of (say) plink.)
4110 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4111 ssh2_pkt_getstring(&banner, &size);
4113 c_write_untrusted(banner, size);
4115 crWaitUntilV(ispkt);
4117 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4118 logevent("Access granted");
4123 if (kbd_inter_running &&
4124 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4126 * This is a further prompt in keyboard-interactive
4127 * authentication. Do nothing.
4129 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4130 bombout(("Strange packet received during authentication: type %d",
4138 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4139 * we can look at the string in it and know what we can
4140 * helpfully try next.
4142 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4145 ssh2_pkt_getstring(&methods, &methlen);
4146 kbd_inter_running = FALSE;
4147 if (!ssh2_pkt_getbool()) {
4149 * We have received an unequivocal Access
4150 * Denied. This can translate to a variety of
4153 * - if we'd just tried "none" authentication,
4154 * it's not worth printing anything at all
4156 * - if we'd just tried a public key _offer_,
4157 * the message should be "Server refused our
4158 * key" (or no message at all if the key
4159 * came from Pageant)
4161 * - if we'd just tried anything else, the
4162 * message really should be "Access denied".
4164 * Additionally, if we'd just tried password
4165 * authentication, we should break out of this
4166 * whole loop so as to go back to the username
4169 if (type == AUTH_TYPE_NONE) {
4171 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4172 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4173 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4174 c_write_str("Server refused our key\r\n");
4175 logevent("Server refused public key");
4176 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4177 /* server declined keyboard-interactive; ignore */
4179 c_write_str("Access denied\r\n");
4180 logevent("Access denied");
4181 if (type == AUTH_TYPE_PASSWORD) {
4187 c_write_str("Further authentication required\r\n");
4188 logevent("Further authentication required");
4192 in_commasep_string("publickey", methods, methlen);
4194 in_commasep_string("password", methods, methlen);
4195 can_keyb_inter = cfg.try_ki_auth &&
4196 in_commasep_string("keyboard-interactive", methods, methlen);
4200 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4202 if (!method && can_pubkey && agent_exists() && !tried_agent) {
4204 * Attempt public-key authentication using Pageant.
4206 static unsigned char request[5], *response, *p;
4207 static int responselen;
4208 static int i, nkeys;
4209 static int authed = FALSE;
4212 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4216 logevent("Pageant is running. Requesting keys.");
4218 /* Request the keys held by the agent. */
4219 PUT_32BIT(request, 1);
4220 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4221 agent_query(request, 5, &r, &responselen);
4222 response = (unsigned char *) r;
4223 if (response && responselen >= 5 &&
4224 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4226 nkeys = GET_32BIT(p);
4230 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4233 for (i = 0; i < nkeys; i++) {
4234 static char *pkblob, *alg, *commentp;
4235 static int pklen, alglen, commentlen;
4236 static int siglen, retlen, len;
4237 static char *q, *agentreq, *ret;
4242 sprintf(buf, "Trying Pageant key #%d", i);
4245 pklen = GET_32BIT(p);
4247 if (publickey_blob &&
4248 pklen == publickey_bloblen &&
4249 !memcmp(p, publickey_blob, publickey_bloblen)) {
4250 logevent("This key matches configured key file");
4251 tried_pubkey_config = 1;
4255 alglen = GET_32BIT(pkblob);
4257 commentlen = GET_32BIT(p);
4261 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4262 ssh2_pkt_addstring(username);
4263 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4264 ssh2_pkt_addstring("publickey"); /* method */
4265 ssh2_pkt_addbool(FALSE); /* no signature included */
4266 ssh2_pkt_addstring_start();
4267 ssh2_pkt_addstring_data(alg, alglen);
4268 ssh2_pkt_addstring_start();
4269 ssh2_pkt_addstring_data(pkblob, pklen);
4272 crWaitUntilV(ispkt);
4273 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4274 logevent("Key refused");
4278 if (flags & FLAG_VERBOSE) {
4280 ("Authenticating with public key \"");
4281 c_write(commentp, commentlen);
4282 c_write_str("\" from agent\r\n");
4286 * Server is willing to accept the key.
4287 * Construct a SIGN_REQUEST.
4289 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4290 ssh2_pkt_addstring(username);
4291 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4292 ssh2_pkt_addstring("publickey"); /* method */
4293 ssh2_pkt_addbool(TRUE);
4294 ssh2_pkt_addstring_start();
4295 ssh2_pkt_addstring_data(alg, alglen);
4296 ssh2_pkt_addstring_start();
4297 ssh2_pkt_addstring_data(pkblob, pklen);
4299 siglen = pktout.length - 5 + 4 + 20;
4300 len = 1; /* message type */
4301 len += 4 + pklen; /* key blob */
4302 len += 4 + siglen; /* data to sign */
4303 len += 4; /* flags */
4304 agentreq = smalloc(4 + len);
4305 PUT_32BIT(agentreq, len);
4307 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4308 PUT_32BIT(q, pklen);
4310 memcpy(q, pkblob, pklen);
4312 PUT_32BIT(q, siglen);
4314 /* Now the data to be signed... */
4317 memcpy(q, ssh2_session_id, 20);
4319 memcpy(q, pktout.data + 5, pktout.length - 5);
4320 q += pktout.length - 5;
4321 /* And finally the (zero) flags word. */
4323 agent_query(agentreq, len + 4, &vret, &retlen);
4327 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4328 logevent("Sending Pageant's response");
4329 ssh2_pkt_addstring_start();
4330 ssh2_pkt_addstring_data(ret + 9,
4338 ("Pageant failed to answer challenge");
4348 if (!method && can_pubkey && *cfg.keyfile
4349 && !tried_pubkey_config) {
4350 unsigned char *pub_blob;
4351 char *algorithm, *comment;
4354 tried_pubkey_config = TRUE;
4356 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4359 * Try the public key supplied in the configuration.
4361 * First, offer the public blob to see if the server is
4362 * willing to accept it.
4364 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4367 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4368 ssh2_pkt_addstring(username);
4369 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4370 ssh2_pkt_addstring("publickey"); /* method */
4371 ssh2_pkt_addbool(FALSE); /* no signature included */
4372 ssh2_pkt_addstring(algorithm);
4373 ssh2_pkt_addstring_start();
4374 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4376 logevent("Offered public key"); /* FIXME */
4378 crWaitUntilV(ispkt);
4379 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4381 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4382 continue; /* key refused; give up on it */
4385 logevent("Offer of public key accepted");
4387 * Actually attempt a serious authentication using
4390 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4392 "Passphrase for key \"%.100s\": ",
4398 c_write_str("Authenticating with public key \"");
4399 c_write_str(comment);
4400 c_write_str("\"\r\n");
4401 method = AUTH_PUBLICKEY_FILE;
4405 if (!method && can_keyb_inter && !tried_keyb_inter) {
4406 method = AUTH_KEYBOARD_INTERACTIVE;
4407 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4408 tried_keyb_inter = TRUE;
4410 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4412 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4413 ssh2_pkt_addstring(username);
4414 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4415 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4416 ssh2_pkt_addstring(""); /* lang */
4417 ssh2_pkt_addstring("");
4420 crWaitUntilV(ispkt);
4421 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4422 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4424 logevent("Keyboard-interactive authentication refused");
4425 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4429 kbd_inter_running = TRUE;
4432 if (kbd_inter_running) {
4433 method = AUTH_KEYBOARD_INTERACTIVE;
4434 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4435 tried_keyb_inter = TRUE;
4437 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4439 /* We've got packet with that "interactive" info
4440 dump banners, and set its prompt as ours */
4442 char *name, *inst, *lang, *prompt;
4443 int name_len, inst_len, lang_len, prompt_len;
4444 ssh2_pkt_getstring(&name, &name_len);
4445 ssh2_pkt_getstring(&inst, &inst_len);
4446 ssh2_pkt_getstring(&lang, &lang_len);
4448 c_write_untrusted(name, name_len);
4450 c_write_untrusted(inst, inst_len);
4451 num_prompts = ssh2_pkt_getuint32();
4453 ssh2_pkt_getstring(&prompt, &prompt_len);
4454 strncpy(pwprompt, prompt, sizeof(pwprompt));
4455 pwprompt[prompt_len < sizeof(pwprompt) ?
4456 prompt_len : sizeof(pwprompt)-1] = '\0';
4459 echo = ssh2_pkt_getbool();
4463 if (!method && can_passwd) {
4464 method = AUTH_PASSWORD;
4465 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4466 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4473 if (!ssh_get_line(pwprompt, password,
4474 sizeof(password), TRUE)) {
4476 * get_line failed to get a password (for
4477 * example because one was supplied on the
4478 * command line which has already failed to
4481 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4482 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4484 ("No more passwords available to try");
4485 ssh2_pkt_addstring("en"); /* language tag */
4487 logevent("Unable to authenticate");
4488 connection_fatal("Unable to authenticate");
4489 ssh_state = SSH_STATE_CLOSED;
4496 c_write_untrusted(pwprompt, strlen(pwprompt));
4501 crWaitUntilV(!ispkt);
4503 switch (c = *in++) {
4523 if (pos < sizeof(password)-1)
4524 password[pos++] = c;
4528 c_write_str("\r\n");
4532 if (method == AUTH_PUBLICKEY_FILE) {
4534 * We have our passphrase. Now try the actual authentication.
4536 struct ssh2_userkey *key;
4538 key = ssh2_load_userkey(cfg.keyfile, password);
4539 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4540 if (key == SSH2_WRONG_PASSPHRASE) {
4541 c_write_str("Wrong passphrase\r\n");
4542 tried_pubkey_config = FALSE;
4544 c_write_str("Unable to load private key\r\n");
4545 tried_pubkey_config = TRUE;
4547 /* Send a spurious AUTH_NONE to return to the top. */
4548 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4549 ssh2_pkt_addstring(username);
4550 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4551 ssh2_pkt_addstring("none"); /* method */
4553 type = AUTH_TYPE_NONE;
4555 unsigned char *blob, *sigdata;
4556 int blob_len, sigdata_len;
4559 * We have loaded the private key and the server
4560 * has announced that it's willing to accept it.
4561 * Hallelujah. Generate a signature and send it.
4563 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4564 ssh2_pkt_addstring(username);
4565 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4566 ssh2_pkt_addstring("publickey"); /* method */
4567 ssh2_pkt_addbool(TRUE);
4568 ssh2_pkt_addstring(key->alg->name);
4569 blob = key->alg->public_blob(key->data, &blob_len);
4570 ssh2_pkt_addstring_start();
4571 ssh2_pkt_addstring_data(blob, blob_len);
4575 * The data to be signed is:
4579 * followed by everything so far placed in the
4582 sigdata_len = pktout.length - 5 + 4 + 20;
4583 sigdata = smalloc(sigdata_len);
4584 PUT_32BIT(sigdata, 20);
4585 memcpy(sigdata + 4, ssh2_session_id, 20);
4586 memcpy(sigdata + 24, pktout.data + 5,
4589 key->alg->sign(key->data, sigdata, sigdata_len,
4591 ssh2_pkt_addstring_start();
4592 ssh2_pkt_addstring_data(blob, blob_len);
4597 type = AUTH_TYPE_PUBLICKEY;
4599 } else if (method == AUTH_PASSWORD) {
4601 * We send the password packet lumped tightly together with
4602 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4603 * string long enough to make the total length of the two
4604 * packets constant. This should ensure that a passive
4605 * listener doing traffic analyis can't work out the length
4608 * For this to work, we need an assumption about the
4609 * maximum length of the password packet. I think 256 is
4610 * pretty conservative. Anyone using a password longer than
4611 * that probably doesn't have much to worry about from
4612 * people who find out how long their password is!
4614 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4615 ssh2_pkt_addstring(username);
4616 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4617 ssh2_pkt_addstring("password");
4618 ssh2_pkt_addbool(FALSE);
4619 ssh2_pkt_addstring(password);
4622 * We'll include a string that's an exact multiple of the
4623 * cipher block size. If the cipher is NULL for some
4624 * reason, we don't do this trick at all because we gain
4630 stringlen = (256 - deferred_len);
4631 stringlen += cscipher->blksize - 1;
4632 stringlen -= (stringlen % cscipher->blksize);
4635 * Temporarily disable actual compression,
4636 * so we can guarantee to get this string
4637 * exactly the length we want it. The
4638 * compression-disabling routine should
4639 * return an integer indicating how many
4640 * bytes we should adjust our string length
4643 stringlen -= cscomp->disable_compression();
4645 ssh2_pkt_init(SSH2_MSG_IGNORE);
4646 ssh2_pkt_addstring_start();
4647 for (i = 0; i < stringlen; i++) {
4648 char c = (char) random_byte();
4649 ssh2_pkt_addstring_data(&c, 1);
4653 ssh_pkt_defersend();
4654 logevent("Sent password");
4655 type = AUTH_TYPE_PASSWORD;
4656 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4657 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4658 ssh2_pkt_adduint32(num_prompts);
4659 ssh2_pkt_addstring(password);
4660 memset(password, 0, sizeof(password));
4662 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4665 ("No supported authentication methods left to try!\r\n");
4667 ("No supported authentications offered. Disconnecting");
4668 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4669 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4671 ("No supported authentication methods available");
4672 ssh2_pkt_addstring("en"); /* language tag */
4674 ssh_state = SSH_STATE_CLOSED;
4678 } while (!we_are_in);
4681 * Now we're authenticated for the connection protocol. The
4682 * connection protocol will automatically have started at this
4683 * point; there's no need to send SERVICE_REQUEST.
4687 * So now create a channel with a session in it.
4689 ssh_channels = newtree234(ssh_channelcmp);
4690 mainchan = smalloc(sizeof(struct ssh_channel));
4691 mainchan->localid = alloc_channel_id();
4692 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4693 ssh2_pkt_addstring("session");
4694 ssh2_pkt_adduint32(mainchan->localid);
4695 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4696 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4697 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4699 crWaitUntilV(ispkt);
4700 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4701 bombout(("Server refused to open a session"));
4703 /* FIXME: error data comes back in FAILURE packet */
4705 if (ssh2_pkt_getuint32() != mainchan->localid) {
4706 bombout(("Server's channel confirmation cited wrong channel"));
4709 mainchan->remoteid = ssh2_pkt_getuint32();
4710 mainchan->type = CHAN_MAINSESSION;
4711 mainchan->closes = 0;
4712 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4713 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4714 bufchain_init(&mainchan->v.v2.outbuffer);
4715 add234(ssh_channels, mainchan);
4716 logevent("Opened channel for session");
4719 * Potentially enable X11 forwarding.
4721 if (cfg.x11_forward) {
4722 char proto[20], data[64];
4723 logevent("Requesting X11 forwarding");
4724 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4725 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4726 ssh2_pkt_adduint32(mainchan->remoteid);
4727 ssh2_pkt_addstring("x11-req");
4728 ssh2_pkt_addbool(1); /* want reply */
4729 ssh2_pkt_addbool(0); /* many connections */
4730 ssh2_pkt_addstring(proto);
4731 ssh2_pkt_addstring(data);
4732 ssh2_pkt_adduint32(0); /* screen number */
4736 crWaitUntilV(ispkt);
4737 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4738 unsigned i = ssh2_pkt_getuint32();
4739 struct ssh_channel *c;
4740 c = find234(ssh_channels, &i, ssh_channelfind);
4742 continue; /* nonexistent channel */
4743 c->v.v2.remwindow += ssh2_pkt_getuint32();
4745 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4747 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4748 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4749 bombout(("Unexpected response to X11 forwarding request:"
4750 " packet type %d", pktin.type));
4753 logevent("X11 forwarding refused");
4755 logevent("X11 forwarding enabled");
4756 ssh_X11_fwd_enabled = TRUE;
4761 * Enable port forwardings.
4764 static char *e; /* preserve across crReturn */
4767 int sport,dport,sserv,dserv;
4768 char sports[256], dports[256], host[256];
4772 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4773 /* Add port forwardings. */
4778 while (*e && *e != '\t')
4784 while (*e && *e != ':')
4794 dport = atoi(dports);
4798 se = getservbyname(dports, NULL);
4800 dport = ntohs(se->s_port);
4803 "Service lookup failed for destination port \"%s\"",
4808 sport = atoi(sports);
4812 se = getservbyname(sports, NULL);
4814 sport = ntohs(se->s_port);
4817 "Service lookup failed for source port \"%s\"",
4822 if (sport && dport) {
4824 pfd_addforward(host, dport, sport);
4825 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
4826 " %s:%.*s%.*s%d%.*s",
4827 sserv ? strlen(sports) : 0, sports,
4828 sserv, "(", sport, sserv, ")",
4830 dserv ? strlen(dports) : 0, dports,
4831 dserv, "(", dport, dserv, ")");
4834 struct ssh_rportfwd *pf;
4835 pf = smalloc(sizeof(*pf));
4836 strcpy(pf->dhost, host);
4839 if (add234(ssh_rportfwds, pf) != pf) {
4841 "Duplicate remote port forwarding to %s:%d",
4846 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
4847 " forward to %s:%.*s%.*s%d%.*s",
4848 sserv ? strlen(sports) : 0, sports,
4849 sserv, "(", sport, sserv, ")",
4851 dserv ? strlen(dports) : 0, dports,
4852 dserv, "(", dport, dserv, ")");
4854 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4855 ssh2_pkt_addstring("tcpip-forward");
4856 ssh2_pkt_addbool(1);/* want reply */
4857 if (cfg.rport_acceptall)
4858 ssh2_pkt_addstring("0.0.0.0");
4860 ssh2_pkt_addstring("127.0.0.1");
4861 ssh2_pkt_adduint32(sport);
4865 crWaitUntilV(ispkt);
4866 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4867 unsigned i = ssh2_pkt_getuint32();
4868 struct ssh_channel *c;
4869 c = find234(ssh_channels, &i, ssh_channelfind);
4871 continue;/* nonexistent channel */
4872 c->v.v2.remwindow += ssh2_pkt_getuint32();
4874 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4876 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4877 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4878 bombout(("Unexpected response to port "
4879 "forwarding request: packet type %d",
4883 logevent("Server refused this port forwarding");
4885 logevent("Remote port forwarding enabled");
4894 * Potentially enable agent forwarding.
4896 if (cfg.agentfwd && agent_exists()) {
4897 logevent("Requesting OpenSSH-style agent forwarding");
4898 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4899 ssh2_pkt_adduint32(mainchan->remoteid);
4900 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4901 ssh2_pkt_addbool(1); /* want reply */
4905 crWaitUntilV(ispkt);
4906 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4907 unsigned i = ssh2_pkt_getuint32();
4908 struct ssh_channel *c;
4909 c = find234(ssh_channels, &i, ssh_channelfind);
4911 continue; /* nonexistent channel */
4912 c->v.v2.remwindow += ssh2_pkt_getuint32();
4914 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4916 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4917 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4918 bombout(("Unexpected response to agent forwarding request:"
4919 " packet type %d", pktin.type));
4922 logevent("Agent forwarding refused");
4924 logevent("Agent forwarding enabled");
4925 ssh_agentfwd_enabled = TRUE;
4930 * Now allocate a pty for the session.
4933 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4934 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4935 ssh2_pkt_addstring("pty-req");
4936 ssh2_pkt_addbool(1); /* want reply */
4937 ssh2_pkt_addstring(cfg.termtype);
4938 ssh2_pkt_adduint32(cols);
4939 ssh2_pkt_adduint32(rows);
4940 ssh2_pkt_adduint32(0); /* pixel width */
4941 ssh2_pkt_adduint32(0); /* pixel height */
4942 ssh2_pkt_addstring_start();
4943 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4945 ssh_state = SSH_STATE_INTERMED;
4948 crWaitUntilV(ispkt);
4949 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4950 unsigned i = ssh2_pkt_getuint32();
4951 struct ssh_channel *c;
4952 c = find234(ssh_channels, &i, ssh_channelfind);
4954 continue; /* nonexistent channel */
4955 c->v.v2.remwindow += ssh2_pkt_getuint32();
4957 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4959 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4960 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4961 bombout(("Unexpected response to pty request:"
4962 " packet type %d", pktin.type));
4965 c_write_str("Server refused to allocate pty\r\n");
4966 ssh_editing = ssh_echoing = 1;
4968 logevent("Allocated pty");
4971 ssh_editing = ssh_echoing = 1;
4975 * Start a shell or a remote command. We may have to attempt
4976 * this twice if the config data has provided a second choice
4983 if (ssh_fallback_cmd) {
4984 subsys = cfg.ssh_subsys2;
4985 cmd = cfg.remote_cmd_ptr2;
4987 subsys = cfg.ssh_subsys;
4988 cmd = cfg.remote_cmd_ptr;
4991 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4992 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
4994 ssh2_pkt_addstring("subsystem");
4995 ssh2_pkt_addbool(1); /* want reply */
4996 ssh2_pkt_addstring(cmd);
4998 ssh2_pkt_addstring("exec");
4999 ssh2_pkt_addbool(1); /* want reply */
5000 ssh2_pkt_addstring(cmd);
5002 ssh2_pkt_addstring("shell");
5003 ssh2_pkt_addbool(1); /* want reply */
5007 crWaitUntilV(ispkt);
5008 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5009 unsigned i = ssh2_pkt_getuint32();
5010 struct ssh_channel *c;
5011 c = find234(ssh_channels, &i, ssh_channelfind);
5013 continue; /* nonexistent channel */
5014 c->v.v2.remwindow += ssh2_pkt_getuint32();
5016 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5017 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5018 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5019 bombout(("Unexpected response to shell/command request:"
5020 " packet type %d", pktin.type));
5024 * We failed to start the command. If this is the
5025 * fallback command, we really are finished; if it's
5026 * not, and if the fallback command exists, try falling
5027 * back to it before complaining.
5029 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5030 logevent("Primary command failed; attempting fallback");
5031 ssh_fallback_cmd = TRUE;
5034 bombout(("Server refused to start a shell/command"));
5037 logevent("Started a shell/command");
5042 ssh_state = SSH_STATE_SESSION;
5046 ssh_special(TS_EOF);
5051 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
5054 static int try_send;
5058 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
5059 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5062 unsigned i = ssh2_pkt_getuint32();
5063 struct ssh_channel *c;
5064 c = find234(ssh_channels, &i, ssh_channelfind);
5066 continue; /* nonexistent channel */
5067 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5068 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5069 continue; /* extended but not stderr */
5070 ssh2_pkt_getstring(&data, &length);
5073 c->v.v2.locwindow -= length;
5075 case CHAN_MAINSESSION:
5077 from_backend(pktin.type ==
5078 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5082 bufsize = x11_send(c->u.x11.s, data, length);
5085 bufsize = pfd_send(c->u.pfd.s, data, length);
5088 while (length > 0) {
5089 if (c->u.a.lensofar < 4) {
5090 int l = min(4 - c->u.a.lensofar, length);
5091 memcpy(c->u.a.msglen + c->u.a.lensofar,
5095 c->u.a.lensofar += l;
5097 if (c->u.a.lensofar == 4) {
5099 4 + GET_32BIT(c->u.a.msglen);
5100 c->u.a.message = smalloc(c->u.a.totallen);
5101 memcpy(c->u.a.message, c->u.a.msglen, 4);
5103 if (c->u.a.lensofar >= 4 && length > 0) {
5105 min(c->u.a.totallen - c->u.a.lensofar,
5107 memcpy(c->u.a.message + c->u.a.lensofar,
5111 c->u.a.lensofar += l;
5113 if (c->u.a.lensofar == c->u.a.totallen) {
5114 void *reply, *sentreply;
5116 agent_query(c->u.a.message,
5117 c->u.a.totallen, &reply,
5122 /* Fake SSH_AGENT_FAILURE. */
5123 sentreply = "\0\0\0\1\5";
5126 ssh2_add_channel_data(c, sentreply,
5131 sfree(c->u.a.message);
5132 c->u.a.lensofar = 0;
5139 * If we are not buffering too much data,
5140 * enlarge the window again at the remote side.
5142 if (bufsize < OUR_V2_WINSIZE)
5143 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5145 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
5146 ssh_state = SSH_STATE_CLOSED;
5147 logevent("Received disconnect message");
5149 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
5150 unsigned i = ssh2_pkt_getuint32();
5151 struct ssh_channel *c;
5153 c = find234(ssh_channels, &i, ssh_channelfind);
5155 continue; /* nonexistent channel */
5157 if (c->type == CHAN_X11) {
5159 * Remote EOF on an X11 channel means we should
5160 * wrap up and close the channel ourselves.
5162 x11_close(c->u.x11.s);
5164 } else if (c->type == CHAN_AGENT) {
5166 } else if (c->type == CHAN_SOCKDATA) {
5167 pfd_close(c->u.pfd.s);
5170 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5171 unsigned i = ssh2_pkt_getuint32();
5172 struct ssh_channel *c;
5174 c = find234(ssh_channels, &i, ssh_channelfind);
5176 continue; /* nonexistent channel */
5177 /* Do pre-close processing on the channel. */
5179 case CHAN_MAINSESSION:
5180 break; /* nothing to see here, move along */
5182 if (c->u.x11.s != NULL)
5183 x11_close(c->u.x11.s);
5190 if (c->u.pfd.s != NULL)
5191 pfd_close(c->u.pfd.s);
5195 if (c->closes == 0) {
5196 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5197 ssh2_pkt_adduint32(c->remoteid);
5200 del234(ssh_channels, c);
5201 bufchain_clear(&c->v.v2.outbuffer);
5205 * See if that was the last channel left open.
5207 if (count234(ssh_channels) == 0) {
5210 * We used to send SSH_MSG_DISCONNECT here,
5211 * because I'd believed that _every_ conforming
5212 * SSH2 connection had to end with a disconnect
5213 * being sent by at least one side; apparently
5214 * I was wrong and it's perfectly OK to
5215 * unceremoniously slam the connection shut
5216 * when you're done, and indeed OpenSSH feels
5217 * this is more polite than sending a
5218 * DISCONNECT. So now we don't.
5220 logevent("All channels closed. Disconnecting");
5221 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5222 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5223 ssh2_pkt_addstring("All open channels closed");
5224 ssh2_pkt_addstring("en"); /* language tag */
5227 ssh_state = SSH_STATE_CLOSED;
5230 continue; /* remote sends close; ignore (FIXME) */
5231 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5232 unsigned i = ssh2_pkt_getuint32();
5233 struct ssh_channel *c;
5234 c = find234(ssh_channels, &i, ssh_channelfind);
5236 continue; /* nonexistent channel */
5237 c->v.v2.remwindow += ssh2_pkt_getuint32();
5239 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5240 unsigned i = ssh2_pkt_getuint32();
5241 struct ssh_channel *c;
5242 c = find234(ssh_channels, &i, ssh_channelfind);
5244 continue; /* nonexistent channel */
5245 if (c->type != CHAN_SOCKDATA_DORMANT)
5246 continue; /* dunno why they're confirming this */
5247 c->remoteid = ssh2_pkt_getuint32();
5248 c->type = CHAN_SOCKDATA;
5249 c->v.v2.remwindow = ssh2_pkt_getuint32();
5250 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5251 bufchain_init(&c->v.v2.outbuffer);
5253 pfd_confirm(c->u.pfd.s);
5256 * We have a pending close on this channel,
5257 * which we decided on before the server acked
5258 * the channel open. So now we know the
5259 * remoteid, we can close it again.
5261 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5262 ssh2_pkt_adduint32(c->remoteid);
5265 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5266 unsigned i = ssh2_pkt_getuint32();
5267 struct ssh_channel *c;
5268 c = find234(ssh_channels, &i, ssh_channelfind);
5270 continue; /* nonexistent channel */
5271 if (c->type != CHAN_SOCKDATA_DORMANT)
5272 continue; /* dunno why they're failing this */
5274 logevent("Forwarded connection refused by server");
5276 pfd_close(c->u.pfd.s);
5278 del234(ssh_channels, c);
5280 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5283 int typelen, want_reply;
5284 struct ssh_channel *c;
5286 localid = ssh2_pkt_getuint32();
5287 ssh2_pkt_getstring(&type, &typelen);
5288 want_reply = ssh2_pkt_getbool();
5291 * First, check that the channel exists. Otherwise,
5292 * we can instantly disconnect with a rude message.
5294 c = find234(ssh_channels, &localid, ssh_channelfind);
5297 sprintf(buf, "Received channel request for nonexistent"
5298 " channel %d", localid);
5300 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5301 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5302 ssh2_pkt_addstring(buf);
5303 ssh2_pkt_addstring("en"); /* language tag */
5305 connection_fatal("%s", buf);
5306 ssh_state = SSH_STATE_CLOSED;
5311 * Having got the channel number, we now look at
5312 * the request type string to see if it's something
5315 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5317 /* We recognise "exit-status" on the primary channel. */
5319 ssh_exitcode = ssh2_pkt_getuint32();
5320 sprintf(buf, "Server sent command exit status %d",
5324 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5325 ssh2_pkt_adduint32(c->remoteid);
5330 * This is a channel request we don't know
5331 * about, so we now either ignore the request
5332 * or respond with CHANNEL_FAILURE, depending
5336 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5337 ssh2_pkt_adduint32(c->remoteid);
5341 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5343 int typelen, want_reply;
5345 ssh2_pkt_getstring(&type, &typelen);
5346 want_reply = ssh2_pkt_getbool();
5349 * We currently don't support any global requests
5350 * at all, so we either ignore the request or
5351 * respond with REQUEST_FAILURE, depending on
5355 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5358 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5362 struct ssh_channel *c;
5363 unsigned remid, winsize, pktsize;
5364 ssh2_pkt_getstring(&type, &typelen);
5365 c = smalloc(sizeof(struct ssh_channel));
5367 remid = ssh2_pkt_getuint32();
5368 winsize = ssh2_pkt_getuint32();
5369 pktsize = ssh2_pkt_getuint32();
5371 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5372 if (!ssh_X11_fwd_enabled)
5373 error = "X11 forwarding is not enabled";
5374 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5376 error = "Unable to open an X11 connection";
5380 } else if (typelen == 15 &&
5381 !memcmp(type, "forwarded-tcpip", 15)) {
5382 struct ssh_rportfwd pf, *realpf;
5385 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5386 pf.sport = ssh2_pkt_getuint32();
5387 realpf = find234(ssh_rportfwds, &pf, NULL);
5388 if (realpf == NULL) {
5389 error = "Remote port is not recognised";
5391 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5394 sprintf(buf, "Received remote port open request for %s:%d",
5395 realpf->dhost, realpf->dport);
5398 sprintf(buf, "Port open failed: %s", e);
5400 error = "Port open failed";
5402 logevent("Forwarded port opened successfully");
5403 c->type = CHAN_SOCKDATA;
5406 } else if (typelen == 22 &&
5407 !memcmp(type, "auth-agent@openssh.com", 3)) {
5408 if (!ssh_agentfwd_enabled)
5409 error = "Agent forwarding is not enabled";
5411 c->type = CHAN_AGENT; /* identify channel type */
5412 c->u.a.lensofar = 0;
5415 error = "Unsupported channel type requested";
5418 c->remoteid = remid;
5420 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5421 ssh2_pkt_adduint32(c->remoteid);
5422 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5423 ssh2_pkt_addstring(error);
5424 ssh2_pkt_addstring("en"); /* language tag */
5428 c->localid = alloc_channel_id();
5430 c->v.v2.locwindow = OUR_V2_WINSIZE;
5431 c->v.v2.remwindow = winsize;
5432 c->v.v2.remmaxpkt = pktsize;
5433 bufchain_init(&c->v.v2.outbuffer);
5434 add234(ssh_channels, c);
5435 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5436 ssh2_pkt_adduint32(c->remoteid);
5437 ssh2_pkt_adduint32(c->localid);
5438 ssh2_pkt_adduint32(c->v.v2.locwindow);
5439 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5443 bombout(("Strange packet received: type %d", pktin.type));
5448 * We have spare data. Add it to the channel buffer.
5450 ssh2_add_channel_data(mainchan, in, inlen);
5455 struct ssh_channel *c;
5457 * Try to send data on all channels if we can.
5459 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5460 int bufsize = ssh2_try_send(c);
5463 case CHAN_MAINSESSION:
5464 /* stdin need not receive an unthrottle
5465 * notification since it will be polled */
5468 x11_unthrottle(c->u.x11.s);
5471 /* agent sockets are request/response and need no
5472 * buffer management */
5475 pfd_unthrottle(c->u.pfd.s);
5487 * Handle the top-level SSH2 protocol.
5489 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5491 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5493 do_ssh2_authconn(in, inlen, ispkt);
5497 * Called to set up the connection.
5499 * Returns an error message, or NULL on success.
5501 static char *ssh_init(char *host, int port, char **realhost, int nodelay)
5506 if (crypto_startup() == 0)
5507 return "Microsoft high encryption pack not installed!";
5513 ssh1_throttle_count = 0;
5514 ssh_overall_bufsize = 0;
5515 ssh_fallback_cmd = 0;
5517 p = connect_to_host(host, port, realhost, nodelay);
5525 * Called to send data down the Telnet connection.
5527 static int ssh_send(char *buf, int len)
5529 if (s == NULL || ssh_protocol == NULL)
5532 ssh_protocol(buf, len, 0);
5534 return ssh_sendbuffer();
5538 * Called to query the current amount of buffered stdin data.
5540 static int ssh_sendbuffer(void)
5544 if (s == NULL || ssh_protocol == NULL)
5548 * If the SSH socket itself has backed up, add the total backup
5549 * size on that to any individual buffer on the stdin channel.
5552 if (ssh_throttled_all)
5553 override_value = ssh_overall_bufsize;
5555 if (ssh_version == 1) {
5556 return override_value;
5557 } else if (ssh_version == 2) {
5558 if (!mainchan || mainchan->closes > 0)
5559 return override_value;
5561 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5568 * Called to set the size of the window from SSH's POV.
5570 static void ssh_size(void)
5572 switch (ssh_state) {
5573 case SSH_STATE_BEFORE_SIZE:
5574 case SSH_STATE_PREPACKET:
5575 case SSH_STATE_CLOSED:
5576 break; /* do nothing */
5577 case SSH_STATE_INTERMED:
5578 size_needed = TRUE; /* buffer for later */
5580 case SSH_STATE_SESSION:
5582 if (ssh_version == 1) {
5583 send_packet(SSH1_CMSG_WINDOW_SIZE,
5584 PKT_INT, rows, PKT_INT, cols,
5585 PKT_INT, 0, PKT_INT, 0, PKT_END);
5587 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5588 ssh2_pkt_adduint32(mainchan->remoteid);
5589 ssh2_pkt_addstring("window-change");
5590 ssh2_pkt_addbool(0);
5591 ssh2_pkt_adduint32(cols);
5592 ssh2_pkt_adduint32(rows);
5593 ssh2_pkt_adduint32(0);
5594 ssh2_pkt_adduint32(0);
5603 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5604 * can send an EOF and collect resulting output (e.g. `plink
5607 static void ssh_special(Telnet_Special code)
5609 if (code == TS_EOF) {
5610 if (ssh_state != SSH_STATE_SESSION) {
5612 * Buffer the EOF in case we are pre-SESSION, so we can
5613 * send it as soon as we reach SESSION.
5619 if (ssh_version == 1) {
5620 send_packet(SSH1_CMSG_EOF, PKT_END);
5622 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5623 ssh2_pkt_adduint32(mainchan->remoteid);
5626 logevent("Sent EOF message");
5627 } else if (code == TS_PING) {
5628 if (ssh_state == SSH_STATE_CLOSED
5629 || ssh_state == SSH_STATE_PREPACKET) return;
5630 if (ssh_version == 1) {
5631 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5633 ssh2_pkt_init(SSH2_MSG_IGNORE);
5634 ssh2_pkt_addstring_start();
5642 void *new_sock_channel(Socket s)
5644 struct ssh_channel *c;
5645 c = smalloc(sizeof(struct ssh_channel));
5648 c->remoteid = -1; /* to be set when open confirmed */
5649 c->localid = alloc_channel_id();
5651 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5653 add234(ssh_channels, c);
5659 * This is called when stdout/stderr (the entity to which
5660 * from_backend sends data) manages to clear some backlog.
5662 void ssh_unthrottle(int bufsize)
5664 if (ssh_version == 1) {
5665 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5666 ssh1_stdout_throttling = 0;
5670 if (mainchan && mainchan->closes == 0)
5671 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5675 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5677 struct ssh_channel *c = (struct ssh_channel *)channel;
5680 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5683 if (ssh_version == 1) {
5684 send_packet(SSH1_MSG_PORT_OPEN,
5685 PKT_INT, c->localid,
5688 //PKT_STR, <org:orgport>,
5691 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5692 ssh2_pkt_addstring("direct-tcpip");
5693 ssh2_pkt_adduint32(c->localid);
5694 c->v.v2.locwindow = OUR_V2_WINSIZE;
5695 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5696 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5697 ssh2_pkt_addstring(hostname);
5698 ssh2_pkt_adduint32(port);
5700 * We make up values for the originator data; partly it's
5701 * too much hassle to keep track, and partly I'm not
5702 * convinced the server should be told details like that
5703 * about my local network configuration.
5705 ssh2_pkt_addstring("client-side-connection");
5706 ssh2_pkt_adduint32(0);
5712 static Socket ssh_socket(void)
5717 static int ssh_sendok(void)
5722 static int ssh_ldisc(int option)
5724 if (option == LD_ECHO)
5726 if (option == LD_EDIT)
5731 static int ssh_return_exitcode(void)
5733 return ssh_exitcode;
5736 Backend ssh_backend = {
5743 ssh_return_exitcode,