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
184 #define BUG_SSH2_RSA_PADDING 16
186 static int ssh_pkt_ctx = 0;
188 #define translate(x) if (type == x) return #x
189 #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
190 char *ssh1_pkt_type(int type)
192 translate(SSH1_MSG_DISCONNECT);
193 translate(SSH1_SMSG_PUBLIC_KEY);
194 translate(SSH1_CMSG_SESSION_KEY);
195 translate(SSH1_CMSG_USER);
196 translate(SSH1_CMSG_AUTH_RSA);
197 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
198 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
199 translate(SSH1_CMSG_AUTH_PASSWORD);
200 translate(SSH1_CMSG_REQUEST_PTY);
201 translate(SSH1_CMSG_WINDOW_SIZE);
202 translate(SSH1_CMSG_EXEC_SHELL);
203 translate(SSH1_CMSG_EXEC_CMD);
204 translate(SSH1_SMSG_SUCCESS);
205 translate(SSH1_SMSG_FAILURE);
206 translate(SSH1_CMSG_STDIN_DATA);
207 translate(SSH1_SMSG_STDOUT_DATA);
208 translate(SSH1_SMSG_STDERR_DATA);
209 translate(SSH1_CMSG_EOF);
210 translate(SSH1_SMSG_EXIT_STATUS);
211 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
212 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
213 translate(SSH1_MSG_CHANNEL_DATA);
214 translate(SSH1_MSG_CHANNEL_CLOSE);
215 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
216 translate(SSH1_SMSG_X11_OPEN);
217 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
218 translate(SSH1_MSG_PORT_OPEN);
219 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
220 translate(SSH1_SMSG_AGENT_OPEN);
221 translate(SSH1_MSG_IGNORE);
222 translate(SSH1_CMSG_EXIT_CONFIRMATION);
223 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
224 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
225 translate(SSH1_MSG_DEBUG);
226 translate(SSH1_CMSG_REQUEST_COMPRESSION);
227 translate(SSH1_CMSG_AUTH_TIS);
228 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
229 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
230 translate(SSH1_CMSG_AUTH_CCARD);
231 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
232 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
235 char *ssh2_pkt_type(int type)
237 translate(SSH2_MSG_DISCONNECT);
238 translate(SSH2_MSG_IGNORE);
239 translate(SSH2_MSG_UNIMPLEMENTED);
240 translate(SSH2_MSG_DEBUG);
241 translate(SSH2_MSG_SERVICE_REQUEST);
242 translate(SSH2_MSG_SERVICE_ACCEPT);
243 translate(SSH2_MSG_KEXINIT);
244 translate(SSH2_MSG_NEWKEYS);
245 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
246 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
247 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
248 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
249 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
250 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
251 translate(SSH2_MSG_USERAUTH_REQUEST);
252 translate(SSH2_MSG_USERAUTH_FAILURE);
253 translate(SSH2_MSG_USERAUTH_SUCCESS);
254 translate(SSH2_MSG_USERAUTH_BANNER);
255 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
256 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
257 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
258 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
259 translate(SSH2_MSG_GLOBAL_REQUEST);
260 translate(SSH2_MSG_REQUEST_SUCCESS);
261 translate(SSH2_MSG_REQUEST_FAILURE);
262 translate(SSH2_MSG_CHANNEL_OPEN);
263 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
264 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
265 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
266 translate(SSH2_MSG_CHANNEL_DATA);
267 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
268 translate(SSH2_MSG_CHANNEL_EOF);
269 translate(SSH2_MSG_CHANNEL_CLOSE);
270 translate(SSH2_MSG_CHANNEL_REQUEST);
271 translate(SSH2_MSG_CHANNEL_SUCCESS);
272 translate(SSH2_MSG_CHANNEL_FAILURE);
278 #define GET_32BIT(cp) \
279 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
280 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
281 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
282 ((unsigned long)(unsigned char)(cp)[3]))
284 #define PUT_32BIT(cp, value) { \
285 (cp)[0] = (unsigned char)((value) >> 24); \
286 (cp)[1] = (unsigned char)((value) >> 16); \
287 (cp)[2] = (unsigned char)((value) >> 8); \
288 (cp)[3] = (unsigned char)(value); }
290 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
292 /* Coroutine mechanics for the sillier bits of the code */
293 #define crBegin1 static int crLine = 0;
294 #define crBegin2 switch(crLine) { case 0:;
295 #define crBegin crBegin1; crBegin2;
296 #define crFinish(z) } crLine = 0; return (z)
297 #define crFinishV } crLine = 0; return
298 #define crReturn(z) \
300 crLine=__LINE__; return (z); case __LINE__:;\
304 crLine=__LINE__; return; case __LINE__:;\
306 #define crStop(z) do{ crLine = 0; return (z); }while(0)
307 #define crStopV do{ crLine = 0; return; }while(0)
308 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
309 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
311 extern char *x11_init(Socket *, char *, void *);
312 extern void x11_close(Socket);
313 extern int x11_send(Socket, char *, int);
314 extern void x11_invent_auth(char *, int, char *, int);
315 extern void x11_unthrottle(Socket s);
316 extern void x11_override_throttle(Socket s, int enable);
318 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
319 extern char *pfd_addforward(char *desthost, int destport, int port);
320 extern void pfd_close(Socket s);
321 extern int pfd_send(Socket s, char *data, int len);
322 extern void pfd_confirm(Socket s);
323 extern void pfd_unthrottle(Socket s);
324 extern void pfd_override_throttle(Socket s, int enable);
326 static void ssh2_pkt_init(int pkt_type);
327 static void ssh2_pkt_addbool(unsigned char value);
328 static void ssh2_pkt_adduint32(unsigned long value);
329 static void ssh2_pkt_addstring_start(void);
330 static void ssh2_pkt_addstring_str(char *data);
331 static void ssh2_pkt_addstring_data(char *data, int len);
332 static void ssh2_pkt_addstring(char *data);
333 static char *ssh2_mpint_fmt(Bignum b, int *len);
334 static void ssh2_pkt_addmp(Bignum b);
335 static int ssh2_pkt_construct(void);
336 static void ssh2_pkt_send(void);
339 * Buffer management constants. There are several of these for
340 * various different purposes:
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
359 #define SSH1_BUFFER_LIMIT 32768
360 #define SSH_MAX_BACKLOG 32768
361 #define OUR_V2_WINSIZE 16384
363 const static struct ssh_kex *kex_algs[] = {
364 &ssh_diffiehellman_gex,
368 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
370 static void nullmac_key(unsigned char *key)
373 static void nullmac_generate(unsigned char *blk, int len,
377 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
381 const static struct ssh_mac ssh_mac_none = {
382 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
384 const static struct ssh_mac *macs[] = {
385 &ssh_sha1, &ssh_md5, &ssh_mac_none
387 const static struct ssh_mac *buggymacs[] = {
388 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
391 static void ssh_comp_none_init(void)
394 static int ssh_comp_none_block(unsigned char *block, int len,
395 unsigned char **outblock, int *outlen)
399 static int ssh_comp_none_disable(void)
403 const static struct ssh_compress ssh_comp_none = {
405 ssh_comp_none_init, ssh_comp_none_block,
406 ssh_comp_none_init, ssh_comp_none_block,
407 ssh_comp_none_disable
409 extern const struct ssh_compress ssh_zlib;
410 const static struct ssh_compress *compressions[] = {
411 &ssh_zlib, &ssh_comp_none
414 enum { /* channel types */
419 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
423 * 2-3-4 tree storing channels.
426 unsigned remoteid, localid;
430 struct ssh1_data_channel {
433 struct ssh2_data_channel {
435 unsigned remwindow, remmaxpkt;
440 struct ssh_agent_channel {
441 unsigned char *message;
442 unsigned char msglen[4];
443 int lensofar, totallen;
445 struct ssh_x11_channel {
448 struct ssh_pfd_channel {
455 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
456 * 2 use this structure in different ways, reflecting SSH 2's
457 * altogether saner approach to port forwarding.
459 * In SSH 1, you arrange a remote forwarding by sending the server
460 * the remote port number, and the local destination host:port.
461 * When a connection comes in, the server sends you back that
462 * host:port pair, and you connect to it. This is a ready-made
463 * security hole if you're not on the ball: a malicious server
464 * could send you back _any_ host:port pair, so if you trustingly
465 * connect to the address it gives you then you've just opened the
466 * entire inside of your corporate network just by connecting
467 * through it to a dodgy SSH server. Hence, we must store a list of
468 * host:port pairs we _are_ trying to forward to, and reject a
469 * connection request from the server if it's not in the list.
471 * In SSH 2, each side of the connection minds its own business and
472 * doesn't send unnecessary information to the other. You arrange a
473 * remote forwarding by sending the server just the remote port
474 * number. When a connection comes in, the server tells you which
475 * of its ports was connected to; and _you_ have to remember what
476 * local host:port pair went with that port number.
478 * Hence: in SSH 1 this structure stores host:port pairs we intend
479 * to allow connections to, and is indexed by those host:port
480 * pairs. In SSH 2 it stores a mapping from source port to
481 * destination host:port pair, and is indexed by source port.
483 struct ssh_rportfwd {
484 unsigned sport, dport;
497 static SHA_State exhash, exhashbase;
499 static Socket s = NULL;
501 static unsigned char session_key[32];
502 static int ssh1_compressing;
503 static int ssh1_remote_protoflags;
504 static int ssh1_local_protoflags;
505 static int ssh_agentfwd_enabled;
506 static int ssh_X11_fwd_enabled;
507 static int ssh_remote_bugs;
508 static const struct ssh_cipher *cipher = NULL;
509 static const struct ssh2_cipher *cscipher = NULL;
510 static const struct ssh2_cipher *sccipher = NULL;
511 static const struct ssh_mac *csmac = NULL;
512 static const struct ssh_mac *scmac = NULL;
513 static const struct ssh_compress *cscomp = NULL;
514 static const struct ssh_compress *sccomp = NULL;
515 static const struct ssh_kex *kex = NULL;
516 static const struct ssh_signkey *hostkey = NULL;
517 static unsigned char ssh2_session_id[20];
519 static char *savedhost;
520 static int savedport;
521 static int ssh_send_ok;
522 static int ssh_echoing, ssh_editing;
524 static tree234 *ssh_channels; /* indexed by local id */
525 static struct ssh_channel *mainchan; /* primary session channel */
526 static int ssh_exitcode = -1;
528 static tree234 *ssh_rportfwds;
532 SSH_STATE_BEFORE_SIZE,
536 } ssh_state = SSH_STATE_PREPACKET;
538 static int size_needed = FALSE, eof_needed = FALSE;
540 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
541 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
542 static unsigned char *deferred_send_data = NULL;
543 static int deferred_len = 0, deferred_size = 0;
546 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
547 * that fails. This variable is the means by which scp.c can reach
548 * into the SSH code and find out which one it got.
550 int ssh_fallback_cmd = 0;
552 static int ssh_version;
553 static int ssh1_throttle_count;
554 static int ssh_overall_bufsize;
555 static int ssh_throttled_all;
556 static int ssh1_stdout_throttling;
557 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
558 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
559 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
560 static void ssh_size(void);
561 static void ssh_special(Telnet_Special);
562 static int ssh2_try_send(struct ssh_channel *c);
563 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
565 static void ssh_throttle_all(int enable, int bufsize);
566 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
567 static int (*s_rdpkt) (unsigned char **data, int *datalen);
568 static int ssh_sendbuffer(void);
570 static struct rdpkt1_state_tag {
571 long len, pad, biglen, to_read;
572 unsigned long realcrc, gotcrc;
578 static struct rdpkt2_state_tag {
579 long len, pad, payload, packetlen, maclen;
582 unsigned long incoming_sequence;
585 static int ssh_channelcmp(void *av, void *bv)
587 struct ssh_channel *a = (struct ssh_channel *) av;
588 struct ssh_channel *b = (struct ssh_channel *) bv;
589 if (a->localid < b->localid)
591 if (a->localid > b->localid)
595 static int ssh_channelfind(void *av, void *bv)
597 unsigned *a = (unsigned *) av;
598 struct ssh_channel *b = (struct ssh_channel *) bv;
606 static int ssh_rportcmp_ssh1(void *av, void *bv)
608 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
609 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
611 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
612 return i < 0 ? -1 : +1;
613 if (a->dport > b->dport)
615 if (a->dport < b->dport)
620 static int ssh_rportcmp_ssh2(void *av, void *bv)
622 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
623 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
625 if (a->sport > b->sport)
627 if (a->sport < b->sport)
632 static int alloc_channel_id(void)
634 const unsigned CHANNEL_NUMBER_OFFSET = 256;
635 unsigned low, high, mid;
637 struct ssh_channel *c;
640 * First-fit allocation of channel numbers: always pick the
641 * lowest unused one. To do this, binary-search using the
642 * counted B-tree to find the largest channel ID which is in a
643 * contiguous sequence from the beginning. (Precisely
644 * everything in that sequence must have ID equal to its tree
645 * index plus CHANNEL_NUMBER_OFFSET.)
647 tsize = count234(ssh_channels);
651 while (high - low > 1) {
652 mid = (high + low) / 2;
653 c = index234(ssh_channels, mid);
654 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
655 low = mid; /* this one is fine */
657 high = mid; /* this one is past it */
660 * Now low points to either -1, or the tree index of the
661 * largest ID in the initial sequence.
664 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
665 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
667 return low + 1 + CHANNEL_NUMBER_OFFSET;
670 static void c_write(char *buf, int len)
672 if ((flags & FLAG_STDERR)) {
674 for (i = 0; i < len; i++)
676 fputc(buf[i], stderr);
679 from_backend(1, buf, len);
682 static void c_write_untrusted(char *buf, int len)
685 for (i = 0; i < len; i++) {
688 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
693 static void c_write_str(char *buf)
695 c_write(buf, strlen(buf));
699 * Collect incoming data in the incoming packet buffer.
700 * Decipher and verify the packet when it is completely read.
701 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
702 * Update the *data and *datalen variables.
703 * Return the additional nr of bytes needed, or 0 when
704 * a complete packet is available.
706 static int ssh1_rdpkt(unsigned char **data, int *datalen)
708 struct rdpkt1_state_tag *st = &rdpkt1_state;
717 for (st->i = st->len = 0; st->i < 4; st->i++) {
718 while ((*datalen) == 0)
720 st->len = (st->len << 8) + **data;
721 (*data)++, (*datalen)--;
724 st->pad = 8 - (st->len % 8);
725 st->biglen = st->len + st->pad;
726 pktin.length = st->len - 5;
728 if (pktin.maxlen < st->biglen) {
729 pktin.maxlen = st->biglen;
730 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
731 srealloc(pktin.data, st->biglen + APIEXTRA));
733 fatalbox("Out of memory");
736 st->to_read = st->biglen;
738 while (st->to_read > 0) {
739 st->chunk = st->to_read;
740 while ((*datalen) == 0)
741 crReturn(st->to_read);
742 if (st->chunk > (*datalen))
743 st->chunk = (*datalen);
744 memcpy(st->p, *data, st->chunk);
746 *datalen -= st->chunk;
748 st->to_read -= st->chunk;
751 if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
752 bombout(("Network attack (CRC compensation) detected!"));
757 cipher->decrypt(pktin.data, st->biglen);
759 st->realcrc = crc32(pktin.data, st->biglen - 4);
760 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
761 if (st->gotcrc != st->realcrc) {
762 bombout(("Incorrect CRC received on packet"));
766 pktin.body = pktin.data + st->pad + 1;
768 if (ssh1_compressing) {
769 unsigned char *decompblk;
771 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
772 &decompblk, &decomplen);
774 if (pktin.maxlen < st->pad + decomplen) {
775 pktin.maxlen = st->pad + decomplen;
776 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
777 pktin.body = pktin.data + st->pad + 1;
779 fatalbox("Out of memory");
782 memcpy(pktin.body - 1, decompblk, decomplen);
784 pktin.length = decomplen - 1;
787 pktin.type = pktin.body[-1];
789 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
790 pktin.body, pktin.length);
792 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
793 pktin.type == SSH1_SMSG_STDERR_DATA ||
794 pktin.type == SSH1_MSG_DEBUG ||
795 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
796 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
797 long stringlen = GET_32BIT(pktin.body);
798 if (stringlen + 4 != pktin.length) {
799 bombout(("Received data packet with bogus string length"));
804 if (pktin.type == SSH1_MSG_DEBUG) {
805 /* log debug message */
807 int stringlen = GET_32BIT(pktin.body);
808 strcpy(buf, "Remote: ");
811 memcpy(buf + 8, pktin.body + 4, stringlen);
812 buf[8 + stringlen] = '\0';
815 } else if (pktin.type == SSH1_MSG_IGNORE) {
820 if (pktin.type == SSH1_MSG_DISCONNECT) {
821 /* log reason code in disconnect message */
823 unsigned msglen = GET_32BIT(pktin.body);
825 strcpy(buf, "Remote sent disconnect: ");
826 nowlen = strlen(buf);
827 if (msglen > sizeof(buf) - nowlen - 1)
828 msglen = sizeof(buf) - nowlen - 1;
829 memcpy(buf + nowlen, pktin.body + 4, msglen);
830 buf[nowlen + msglen] = '\0';
831 /* logevent(buf); (this is now done within the bombout macro) */
832 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
839 static int ssh2_rdpkt(unsigned char **data, int *datalen)
841 struct rdpkt2_state_tag *st = &rdpkt2_state;
849 st->cipherblk = sccipher->blksize;
852 if (st->cipherblk < 8)
855 if (pktin.maxlen < st->cipherblk) {
856 pktin.maxlen = st->cipherblk;
859 NULL ? smalloc(st->cipherblk +
860 APIEXTRA) : srealloc(pktin.data,
864 fatalbox("Out of memory");
868 * Acquire and decrypt the first block of the packet. This will
869 * contain the length and padding details.
871 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
872 while ((*datalen) == 0)
873 crReturn(st->cipherblk - st->i);
874 pktin.data[st->i] = *(*data)++;
879 sccipher->decrypt(pktin.data, st->cipherblk);
882 * Now get the length and padding figures.
884 st->len = GET_32BIT(pktin.data);
885 st->pad = pktin.data[4];
888 * This enables us to deduce the payload length.
890 st->payload = st->len - st->pad - 1;
892 pktin.length = st->payload + 5;
895 * So now we can work out the total packet length.
897 st->packetlen = st->len + 4;
898 st->maclen = scmac ? scmac->len : 0;
901 * Adjust memory allocation if packet is too big.
903 if (pktin.maxlen < st->packetlen + st->maclen) {
904 pktin.maxlen = st->packetlen + st->maclen;
907 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
912 fatalbox("Out of memory");
916 * Read and decrypt the remainder of the packet.
918 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
920 while ((*datalen) == 0)
921 crReturn(st->packetlen + st->maclen - st->i);
922 pktin.data[st->i] = *(*data)++;
925 /* Decrypt everything _except_ the MAC. */
927 sccipher->decrypt(pktin.data + st->cipherblk,
928 st->packetlen - st->cipherblk);
934 && !scmac->verify(pktin.data, st->len + 4,
935 st->incoming_sequence)) {
936 bombout(("Incorrect MAC received on packet"));
939 st->incoming_sequence++; /* whether or not we MACed */
942 * Decompress packet payload.
945 unsigned char *newpayload;
947 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
948 &newpayload, &newlen)) {
949 if (pktin.maxlen < newlen + 5) {
950 pktin.maxlen = newlen + 5;
953 NULL ? smalloc(pktin.maxlen +
954 APIEXTRA) : srealloc(pktin.data,
958 fatalbox("Out of memory");
960 pktin.length = 5 + newlen;
961 memcpy(pktin.data + 5, newpayload, newlen);
967 pktin.type = pktin.data[5];
969 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
970 pktin.data+6, pktin.length-6);
972 switch (pktin.type) {
974 * These packets we must handle instantly.
976 case SSH2_MSG_DISCONNECT:
978 /* log reason code in disconnect message */
980 int reason = GET_32BIT(pktin.data + 6);
981 unsigned msglen = GET_32BIT(pktin.data + 10);
983 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
984 sprintf(buf, "Received disconnect message (%s)",
985 ssh2_disconnect_reasons[reason]);
987 sprintf(buf, "Received disconnect message (unknown type %d)",
991 strcpy(buf, "Disconnection message text: ");
992 nowlen = strlen(buf);
993 if (msglen > sizeof(buf) - nowlen - 1)
994 msglen = sizeof(buf) - nowlen - 1;
995 memcpy(buf + nowlen, pktin.data + 14, msglen);
996 buf[nowlen + msglen] = '\0';
998 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1000 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1001 ssh2_disconnect_reasons[reason] : "unknown",
1006 case SSH2_MSG_IGNORE:
1008 case SSH2_MSG_DEBUG:
1010 /* log the debug message */
1012 /* int display = pktin.body[6]; */
1013 int stringlen = GET_32BIT(pktin.data+7);
1015 strcpy(buf, "Remote debug message: ");
1016 prefix = strlen(buf);
1017 if (stringlen > sizeof(buf)-prefix-1)
1018 stringlen = sizeof(buf)-prefix-1;
1019 memcpy(buf + prefix, pktin.data + 11, stringlen);
1020 buf[prefix + stringlen] = '\0';
1023 goto next_packet; /* FIXME: print the debug message */
1026 * These packets we need do nothing about here.
1028 case SSH2_MSG_UNIMPLEMENTED:
1029 case SSH2_MSG_SERVICE_REQUEST:
1030 case SSH2_MSG_SERVICE_ACCEPT:
1031 case SSH2_MSG_KEXINIT:
1032 case SSH2_MSG_NEWKEYS:
1033 case SSH2_MSG_KEXDH_INIT:
1034 case SSH2_MSG_KEXDH_REPLY:
1035 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1036 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1037 case SSH2_MSG_KEX_DH_GEX_INIT:
1038 case SSH2_MSG_KEX_DH_GEX_REPLY:
1039 case SSH2_MSG_USERAUTH_REQUEST:
1040 case SSH2_MSG_USERAUTH_FAILURE:
1041 case SSH2_MSG_USERAUTH_SUCCESS:
1042 case SSH2_MSG_USERAUTH_BANNER:
1043 case SSH2_MSG_USERAUTH_PK_OK:
1044 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1045 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1046 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1047 case SSH2_MSG_GLOBAL_REQUEST:
1048 case SSH2_MSG_REQUEST_SUCCESS:
1049 case SSH2_MSG_REQUEST_FAILURE:
1050 case SSH2_MSG_CHANNEL_OPEN:
1051 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1052 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1053 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1054 case SSH2_MSG_CHANNEL_DATA:
1055 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1056 case SSH2_MSG_CHANNEL_EOF:
1057 case SSH2_MSG_CHANNEL_CLOSE:
1058 case SSH2_MSG_CHANNEL_REQUEST:
1059 case SSH2_MSG_CHANNEL_SUCCESS:
1060 case SSH2_MSG_CHANNEL_FAILURE:
1064 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1067 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
1068 ssh2_pkt_adduint32(st->incoming_sequence - 1);
1076 static void ssh1_pktout_size(int len)
1080 len += 5; /* type and CRC */
1081 pad = 8 - (len % 8);
1084 pktout.length = len - 5;
1085 if (pktout.maxlen < biglen) {
1086 pktout.maxlen = biglen;
1088 /* Allocate enough buffer space for extra block
1089 * for MS CryptEncrypt() */
1090 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
1091 srealloc(pktout.data, biglen + 12));
1093 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
1094 srealloc(pktout.data, biglen + 4));
1097 fatalbox("Out of memory");
1099 pktout.body = pktout.data + 4 + pad + 1;
1102 static void s_wrpkt_start(int type, int len)
1104 ssh1_pktout_size(len);
1108 static int s_wrpkt_prepare(void)
1110 int pad, len, biglen, i;
1113 pktout.body[-1] = pktout.type;
1115 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1116 pktout.body, pktout.length);
1118 if (ssh1_compressing) {
1119 unsigned char *compblk;
1121 zlib_compress_block(pktout.body - 1, pktout.length + 1,
1122 &compblk, &complen);
1123 ssh1_pktout_size(complen - 1);
1124 memcpy(pktout.body - 1, compblk, complen);
1128 len = pktout.length + 5; /* type and CRC */
1129 pad = 8 - (len % 8);
1132 for (i = 0; i < pad; i++)
1133 pktout.data[i + 4] = random_byte();
1134 crc = crc32(pktout.data + 4, biglen - 4);
1135 PUT_32BIT(pktout.data + biglen, crc);
1136 PUT_32BIT(pktout.data, len);
1139 cipher->encrypt(pktout.data + 4, biglen);
1144 static void s_wrpkt(void)
1147 len = s_wrpkt_prepare();
1148 backlog = sk_write(s, pktout.data, len);
1149 if (backlog > SSH_MAX_BACKLOG)
1150 ssh_throttle_all(1, backlog);
1153 static void s_wrpkt_defer(void)
1156 len = s_wrpkt_prepare();
1157 if (deferred_len + len > deferred_size) {
1158 deferred_size = deferred_len + len + 128;
1159 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1161 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1162 deferred_len += len;
1166 * Construct a packet with the specified contents.
1168 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1170 unsigned char *p, *argp, argchar;
1171 unsigned long argint;
1172 int pktlen, argtype, arglen;
1176 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1179 (void) va_arg(ap1, int);
1183 (void) va_arg(ap1, char);
1187 (void) va_arg(ap1, unsigned char *);
1188 arglen = va_arg(ap1, int);
1192 argp = va_arg(ap1, unsigned char *);
1193 arglen = strlen(argp);
1194 pktlen += 4 + arglen;
1197 bn = va_arg(ap1, Bignum);
1198 pktlen += ssh1_bignum_length(bn);
1205 s_wrpkt_start(pkttype, pktlen);
1208 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1211 argint = va_arg(ap2, int);
1212 PUT_32BIT(p, argint);
1216 argchar = va_arg(ap2, unsigned char);
1221 argp = va_arg(ap2, unsigned char *);
1222 arglen = va_arg(ap2, int);
1223 memcpy(p, argp, arglen);
1227 argp = va_arg(ap2, unsigned char *);
1228 arglen = strlen(argp);
1229 PUT_32BIT(p, arglen);
1230 memcpy(p + 4, argp, arglen);
1234 bn = va_arg(ap2, Bignum);
1235 p += ssh1_write_bignum(p, bn);
1241 static void send_packet(int pkttype, ...)
1244 va_start(ap1, pkttype);
1245 va_start(ap2, pkttype);
1246 construct_packet(pkttype, ap1, ap2);
1250 static void defer_packet(int pkttype, ...)
1253 va_start(ap1, pkttype);
1254 va_start(ap2, pkttype);
1255 construct_packet(pkttype, ap1, ap2);
1259 static int ssh_versioncmp(char *a, char *b)
1262 unsigned long av, bv;
1264 av = strtoul(a, &ae, 10);
1265 bv = strtoul(b, &be, 10);
1267 return (av < bv ? -1 : +1);
1272 av = strtoul(ae, &ae, 10);
1273 bv = strtoul(be, &be, 10);
1275 return (av < bv ? -1 : +1);
1281 * Utility routines for putting an SSH-protocol `string' and
1282 * `uint32' into a SHA state.
1285 static void sha_string(SHA_State * s, void *str, int len)
1287 unsigned char lenblk[4];
1288 PUT_32BIT(lenblk, len);
1289 SHA_Bytes(s, lenblk, 4);
1290 SHA_Bytes(s, str, len);
1293 static void sha_uint32(SHA_State * s, unsigned i)
1295 unsigned char intblk[4];
1296 PUT_32BIT(intblk, i);
1297 SHA_Bytes(s, intblk, 4);
1301 * SSH2 packet construction functions.
1303 static void ssh2_pkt_ensure(int length)
1305 if (pktout.maxlen < length) {
1306 pktout.maxlen = length + 256;
1309 NULL ? smalloc(pktout.maxlen +
1310 APIEXTRA) : srealloc(pktout.data,
1314 fatalbox("Out of memory");
1317 static void ssh2_pkt_adddata(void *data, int len)
1319 pktout.length += len;
1320 ssh2_pkt_ensure(pktout.length);
1321 memcpy(pktout.data + pktout.length - len, data, len);
1323 static void ssh2_pkt_addbyte(unsigned char byte)
1325 ssh2_pkt_adddata(&byte, 1);
1327 static void ssh2_pkt_init(int pkt_type)
1330 ssh2_pkt_addbyte((unsigned char) pkt_type);
1332 static void ssh2_pkt_addbool(unsigned char value)
1334 ssh2_pkt_adddata(&value, 1);
1336 static void ssh2_pkt_adduint32(unsigned long value)
1339 PUT_32BIT(x, value);
1340 ssh2_pkt_adddata(x, 4);
1342 static void ssh2_pkt_addstring_start(void)
1344 ssh2_pkt_adduint32(0);
1345 pktout.savedpos = pktout.length;
1347 static void ssh2_pkt_addstring_str(char *data)
1349 ssh2_pkt_adddata(data, strlen(data));
1350 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1351 pktout.length - pktout.savedpos);
1353 static void ssh2_pkt_addstring_data(char *data, int len)
1355 ssh2_pkt_adddata(data, len);
1356 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1357 pktout.length - pktout.savedpos);
1359 static void ssh2_pkt_addstring(char *data)
1361 ssh2_pkt_addstring_start();
1362 ssh2_pkt_addstring_str(data);
1364 static char *ssh2_mpint_fmt(Bignum b, int *len)
1367 int i, n = (bignum_bitcount(b) + 7) / 8;
1370 fatalbox("out of memory");
1372 for (i = 1; i <= n; i++)
1373 p[i] = bignum_byte(b, n - i);
1375 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1377 memmove(p, p + i, n + 1 - i);
1381 static void ssh2_pkt_addmp(Bignum b)
1385 p = ssh2_mpint_fmt(b, &len);
1386 ssh2_pkt_addstring_start();
1387 ssh2_pkt_addstring_data(p, len);
1392 * Construct an SSH2 final-form packet: compress it, encrypt it,
1393 * put the MAC on it. Final packet, ready to be sent, is stored in
1394 * pktout.data. Total length is returned.
1396 static int ssh2_pkt_construct(void)
1398 int cipherblk, maclen, padding, i;
1399 static unsigned long outgoing_sequence = 0;
1401 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1402 pktout.data + 6, pktout.length - 6);
1405 * Compress packet payload.
1408 unsigned char *newpayload;
1410 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1411 &newpayload, &newlen)) {
1413 ssh2_pkt_adddata(newpayload, newlen);
1419 * Add padding. At least four bytes, and must also bring total
1420 * length (minus MAC) up to a multiple of the block size.
1422 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1423 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1426 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1427 maclen = csmac ? csmac->len : 0;
1428 ssh2_pkt_ensure(pktout.length + padding + maclen);
1429 pktout.data[4] = padding;
1430 for (i = 0; i < padding; i++)
1431 pktout.data[pktout.length + i] = random_byte();
1432 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1434 csmac->generate(pktout.data, pktout.length + padding,
1436 outgoing_sequence++; /* whether or not we MACed */
1439 cscipher->encrypt(pktout.data, pktout.length + padding);
1441 /* Ready-to-send packet starts at pktout.data. We return length. */
1442 return pktout.length + padding + maclen;
1446 * Construct and send an SSH2 packet immediately.
1448 static void ssh2_pkt_send(void)
1452 len = ssh2_pkt_construct();
1453 backlog = sk_write(s, pktout.data, len);
1454 if (backlog > SSH_MAX_BACKLOG)
1455 ssh_throttle_all(1, backlog);
1459 * Construct an SSH2 packet and add it to a deferred data block.
1460 * Useful for sending multiple packets in a single sk_write() call,
1461 * to prevent a traffic-analysing listener from being able to work
1462 * out the length of any particular packet (such as the password
1465 * Note that because SSH2 sequence-numbers its packets, this can
1466 * NOT be used as an m4-style `defer' allowing packets to be
1467 * constructed in one order and sent in another.
1469 static void ssh2_pkt_defer(void)
1471 int len = ssh2_pkt_construct();
1472 if (deferred_len + len > deferred_size) {
1473 deferred_size = deferred_len + len + 128;
1474 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1476 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1477 deferred_len += len;
1481 * Send the whole deferred data block constructed by
1482 * ssh2_pkt_defer() or SSH1's defer_packet().
1484 static void ssh_pkt_defersend(void)
1487 backlog = sk_write(s, deferred_send_data, deferred_len);
1488 deferred_len = deferred_size = 0;
1489 sfree(deferred_send_data);
1490 deferred_send_data = NULL;
1491 if (backlog > SSH_MAX_BACKLOG)
1492 ssh_throttle_all(1, backlog);
1496 void bndebug(char *string, Bignum b)
1500 p = ssh2_mpint_fmt(b, &len);
1501 debug(("%s", string));
1502 for (i = 0; i < len; i++)
1503 debug((" %02x", p[i]));
1509 static void sha_mpint(SHA_State * s, Bignum b)
1513 p = ssh2_mpint_fmt(b, &len);
1514 sha_string(s, p, len);
1519 * SSH2 packet decode functions.
1521 static unsigned long ssh2_pkt_getuint32(void)
1523 unsigned long value;
1524 if (pktin.length - pktin.savedpos < 4)
1525 return 0; /* arrgh, no way to decline (FIXME?) */
1526 value = GET_32BIT(pktin.data + pktin.savedpos);
1527 pktin.savedpos += 4;
1530 static int ssh2_pkt_getbool(void)
1532 unsigned long value;
1533 if (pktin.length - pktin.savedpos < 1)
1534 return 0; /* arrgh, no way to decline (FIXME?) */
1535 value = pktin.data[pktin.savedpos] != 0;
1539 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 * Helper function to add an SSH2 signature blob to a packet.
1571 * Expects to be shown the public key blob as well as the signature
1572 * blob. Normally works just like ssh2_pkt_addstring, but will
1573 * fiddle with the signature packet if necessary for
1574 * BUG_SSH2_RSA_PADDING.
1576 static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len,
1577 void *sigblob_v, int sigblob_len)
1579 unsigned char *pkblob = (unsigned char *)pkblob_v;
1580 unsigned char *sigblob = (unsigned char *)sigblob_v;
1582 /* dmemdump(pkblob, pkblob_len); */
1583 /* dmemdump(sigblob, sigblob_len); */
1586 * See if this is in fact an ssh-rsa signature and a buggy
1587 * server; otherwise we can just do this the easy way.
1589 if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) &&
1590 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1591 int pos, len, siglen;
1594 * Find the byte length of the modulus.
1597 pos = 4+7; /* skip over "ssh-rsa" */
1598 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1599 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1600 pos += 4; /* find modulus itself */
1601 while (len > 0 && pkblob[pos] == 0)
1603 /* debug(("modulus length is %d\n", len)); */
1606 * Now find the signature integer.
1608 pos = 4+7; /* skip over "ssh-rsa" */
1609 siglen = GET_32BIT(sigblob+pos);
1610 /* debug(("signature length is %d\n", siglen)); */
1612 if (len != siglen) {
1613 unsigned char newlen[4];
1614 ssh2_pkt_addstring_start();
1615 ssh2_pkt_addstring_data(sigblob, pos);
1616 /* dmemdump(sigblob, pos); */
1617 pos += 4; /* point to start of actual sig */
1618 PUT_32BIT(newlen, len);
1619 ssh2_pkt_addstring_data(newlen, 4);
1620 /* dmemdump(newlen, 4); */
1622 while (len-- > siglen) {
1623 ssh2_pkt_addstring_data(newlen, 1);
1624 /* dmemdump(newlen, 1); */
1626 ssh2_pkt_addstring_data(sigblob+pos, siglen);
1627 /* dmemdump(sigblob+pos, siglen); */
1631 /* Otherwise fall through and do it the easy way. */
1634 ssh2_pkt_addstring_start();
1635 ssh2_pkt_addstring_data(sigblob, sigblob_len);
1639 * Examine the remote side's version string and compare it against
1640 * a list of known buggy implementations.
1642 static void ssh_detect_bugs(char *vstring)
1644 char *imp; /* pointer to implementation part */
1646 imp += strcspn(imp, "-");
1648 imp += strcspn(imp, "-");
1651 ssh_remote_bugs = 0;
1653 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1654 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1655 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
1657 * These versions don't support SSH1_MSG_IGNORE, so we have
1658 * to use a different defence against password length
1661 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1662 logevent("We believe remote version has SSH1 ignore bug");
1665 if (!strcmp(imp, "Cisco-1.25")) {
1667 * These versions need a plain password sent; they can't
1668 * handle having a null and a random length of data after
1671 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1672 logevent("We believe remote version needs a plain SSH1 password");
1675 if (!strcmp(imp, "Cisco-1.25")) {
1677 * These versions apparently have no clue whatever about
1678 * RSA authentication and will panic and die if they see
1679 * an AUTH_RSA message.
1681 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1682 logevent("We believe remote version can't handle RSA authentication");
1685 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1686 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1687 !strncmp(imp, "2.1 ", 4)) {
1689 * These versions have the HMAC bug.
1691 ssh_remote_bugs |= BUG_SSH2_HMAC;
1692 logevent("We believe remote version has SSH2 HMAC bug");
1695 if ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1696 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')) {
1698 * These versions have the SSH2 RSA padding bug.
1700 ssh_remote_bugs |= BUG_SSH2_RSA_PADDING;
1701 logevent("We believe remote version has SSH2 RSA padding bug");
1705 static int do_ssh_init(unsigned char c)
1708 static char version[10];
1709 static char *vstring;
1710 static int vstrsize;
1713 static int proto1, proto2;
1717 /* Search for the string "SSH-" in the input. */
1720 static const int transS[] = { 1, 2, 2, 1 };
1721 static const int transH[] = { 0, 0, 3, 0 };
1722 static const int transminus[] = { 0, 0, 0, -1 };
1733 crReturn(1); /* get another character */
1737 vstring = smalloc(vstrsize);
1738 strcpy(vstring, "SSH-");
1742 crReturn(1); /* get another char */
1743 if (vslen >= vstrsize - 1) {
1745 vstring = srealloc(vstring, vstrsize);
1747 vstring[vslen++] = c;
1752 } else if (i < sizeof(version) - 1)
1754 } else if (c == '\n')
1758 ssh_agentfwd_enabled = FALSE;
1759 rdpkt2_state.incoming_sequence = 0;
1762 vlog = smalloc(20 + vslen);
1763 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
1764 sprintf(vlog, "Server version: %s", vstring);
1766 ssh_detect_bugs(vstring);
1770 * Decide which SSH protocol version to support.
1773 /* Anything strictly below "2.0" means protocol 1 is supported. */
1774 proto1 = ssh_versioncmp(version, "2.0") < 0;
1775 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1776 proto2 = ssh_versioncmp(version, "1.99") >= 0;
1778 if (cfg.sshprot == 0 && !proto1) {
1779 bombout(("SSH protocol version 1 required by user but not provided by server"));
1782 if (cfg.sshprot == 3 && !proto2) {
1783 bombout(("SSH protocol version 2 required by user but not provided by server"));
1787 if (proto2 && (cfg.sshprot >= 2 || !proto1)) {
1791 char verstring[80], vlog[100];
1792 sprintf(verstring, "SSH-2.0-%s", sshver);
1793 SHA_Init(&exhashbase);
1795 * Hash our version string and their version string.
1797 sha_string(&exhashbase, verstring, strlen(verstring));
1798 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1799 sprintf(vlog, "We claim version: %s", verstring);
1801 strcat(verstring, "\n");
1802 logevent("Using SSH protocol version 2");
1803 sk_write(s, verstring, strlen(verstring));
1804 ssh_protocol = ssh2_protocol;
1806 s_rdpkt = ssh2_rdpkt;
1811 char verstring[80], vlog[100];
1812 sprintf(verstring, "SSH-%s-%s",
1813 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1815 sprintf(vlog, "We claim version: %s", verstring);
1817 strcat(verstring, "\n");
1819 logevent("Using SSH protocol version 1");
1820 sk_write(s, verstring, strlen(verstring));
1821 ssh_protocol = ssh1_protocol;
1823 s_rdpkt = ssh1_rdpkt;
1825 ssh_state = SSH_STATE_BEFORE_SIZE;
1832 static void ssh_gotdata(unsigned char *data, int datalen)
1837 * To begin with, feed the characters one by one to the
1838 * protocol initialisation / selection function do_ssh_init().
1839 * When that returns 0, we're done with the initial greeting
1840 * exchange and can move on to packet discipline.
1845 crReturnV; /* more data please */
1846 ret = do_ssh_init(*data);
1854 * We emerge from that loop when the initial negotiation is
1855 * over and we have selected an s_rdpkt function. Now pass
1856 * everything to s_rdpkt, and then pass the resulting packets
1857 * to the proper protocol handler.
1862 while (datalen > 0) {
1863 if (s_rdpkt(&data, &datalen) == 0) {
1864 if (ssh_state == SSH_STATE_CLOSED) {
1867 ssh_protocol(NULL, 0, 1);
1868 if (ssh_state == SSH_STATE_CLOSED) {
1878 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1881 ssh_state = SSH_STATE_CLOSED;
1887 /* A socket error has occurred. */
1888 logevent(error_msg);
1889 connection_fatal(error_msg);
1891 /* Otherwise, the remote side closed the connection normally. */
1896 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1898 ssh_gotdata(data, len);
1899 if (ssh_state == SSH_STATE_CLOSED) {
1909 static void ssh_sent(Plug plug, int bufsize)
1912 * If the send backlog on the SSH socket itself clears, we
1913 * should unthrottle the whole world if it was throttled.
1915 if (bufsize < SSH_MAX_BACKLOG)
1916 ssh_throttle_all(0, bufsize);
1920 * Connect to specified host and port.
1921 * Returns an error message, or NULL on success.
1922 * Also places the canonical host name into `realhost'. It must be
1923 * freed by the caller.
1925 static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
1927 static struct plug_function_table fn_table = {
1932 }, *fn_table_ptr = &fn_table;
1941 savedhost = smalloc(1 + strlen(host));
1943 fatalbox("Out of memory");
1944 strcpy(savedhost, host);
1947 port = 22; /* default ssh port */
1962 sprintf(buf, "Looking up host \"%.170s\"", host);
1965 addr = sk_namelookup(host, realhost);
1966 if ((err = sk_addr_error(addr)))
1970 *realhost = strdup(FWhost);
1977 char buf[200], addrbuf[100];
1978 sk_getaddr(addr, addrbuf, 100);
1979 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1982 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
1983 if ((err = sk_socket_error(s))) {
1989 sk_write(s, "connect ", 8);
1990 sk_write(s, FWhost, strlen(FWhost));
1993 sprintf(buf, " %d\n", FWport);
1994 sk_write(s, buf, strlen(buf));
2002 * Throttle or unthrottle the SSH connection.
2004 static void ssh1_throttle(int adjust)
2006 int old_count = ssh1_throttle_count;
2007 ssh1_throttle_count += adjust;
2008 assert(ssh1_throttle_count >= 0);
2009 if (ssh1_throttle_count && !old_count) {
2010 sk_set_frozen(s, 1);
2011 } else if (!ssh1_throttle_count && old_count) {
2012 sk_set_frozen(s, 0);
2017 * Throttle or unthrottle _all_ local data streams (for when sends
2018 * on the SSH connection itself back up).
2020 static void ssh_throttle_all(int enable, int bufsize)
2023 struct ssh_channel *c;
2025 if (enable == ssh_throttled_all)
2027 ssh_throttled_all = enable;
2028 ssh_overall_bufsize = bufsize;
2031 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
2033 case CHAN_MAINSESSION:
2035 * This is treated separately, outside the switch.
2039 x11_override_throttle(c->u.x11.s, enable);
2042 /* Agent channels require no buffer management. */
2045 pfd_override_throttle(c->u.x11.s, enable);
2052 * Username and password input, abstracted off into reusable
2053 * routines (hopefully even reusable between SSH1 and SSH2!).
2055 static char *ssh_userpass_input_buffer;
2056 static int ssh_userpass_input_buflen;
2057 static int ssh_userpass_input_bufpos;
2058 static int ssh_userpass_input_echo;
2060 /* Set up a username or password input loop on a given buffer. */
2061 void setup_userpass_input(char *buffer, int buflen, int echo)
2063 ssh_userpass_input_buffer = buffer;
2064 ssh_userpass_input_buflen = buflen;
2065 ssh_userpass_input_bufpos = 0;
2066 ssh_userpass_input_echo = echo;
2070 * Process some terminal data in the course of username/password
2071 * input. Returns >0 for success (line of input returned in
2072 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2073 * for inconclusive (keep waiting for more input please).
2075 int process_userpass_input(unsigned char *in, int inlen)
2080 switch (c = *in++) {
2083 ssh_userpass_input_buffer[ssh_userpass_input_bufpos] = 0;
2084 ssh_userpass_input_buffer[ssh_userpass_input_buflen-1] = 0;
2089 if (ssh_userpass_input_bufpos > 0) {
2090 if (ssh_userpass_input_echo)
2091 c_write_str("\b \b");
2092 ssh_userpass_input_bufpos--;
2097 while (ssh_userpass_input_bufpos > 0) {
2098 if (ssh_userpass_input_echo)
2099 c_write_str("\b \b");
2100 ssh_userpass_input_bufpos--;
2108 if (((c >= ' ' && c <= '~') ||
2109 ((unsigned char) c >= 160))
2110 && ssh_userpass_input_bufpos < ssh_userpass_input_buflen-1) {
2111 ssh_userpass_input_buffer[ssh_userpass_input_bufpos++] = c;
2112 if (ssh_userpass_input_echo)
2122 * Handle the key exchange and user authentication phases.
2124 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
2128 static unsigned char *rsabuf, *keystr1, *keystr2;
2129 unsigned char cookie[8];
2130 struct RSAKey servkey, hostkey;
2131 struct MD5Context md5c;
2132 static unsigned long supported_ciphers_mask, supported_auths_mask;
2133 static int tried_publickey, tried_agent;
2134 static int tis_auth_refused, ccard_auth_refused;
2135 static unsigned char session_id[16];
2136 static int cipher_type;
2137 static char username[100];
2138 static void *publickey_blob;
2139 int publickey_bloblen;
2146 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2147 bombout(("Public key packet not received"));
2151 logevent("Received public keys");
2153 memcpy(cookie, pktin.body, 8);
2155 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2156 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
2159 * Log the host key fingerprint.
2163 logevent("Host key fingerprint is:");
2164 strcpy(logmsg, " ");
2165 hostkey.comment = NULL;
2166 rsa_fingerprint(logmsg + strlen(logmsg),
2167 sizeof(logmsg) - strlen(logmsg), &hostkey);
2171 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2172 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2173 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
2175 ssh1_local_protoflags =
2176 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2177 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2180 MD5Update(&md5c, keystr2, hostkey.bytes);
2181 MD5Update(&md5c, keystr1, servkey.bytes);
2182 MD5Update(&md5c, pktin.body, 8);
2183 MD5Final(session_id, &md5c);
2185 for (i = 0; i < 32; i++)
2186 session_key[i] = random_byte();
2188 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2190 rsabuf = smalloc(len);
2192 fatalbox("Out of memory");
2195 * Verify the host key.
2199 * First format the key into a string.
2201 int len = rsastr_len(&hostkey);
2202 char fingerprint[100];
2203 char *keystr = smalloc(len);
2205 fatalbox("Out of memory");
2206 rsastr_fmt(keystr, &hostkey);
2207 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2208 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2213 for (i = 0; i < 32; i++) {
2214 rsabuf[i] = session_key[i];
2216 rsabuf[i] ^= session_id[i];
2219 if (hostkey.bytes > servkey.bytes) {
2220 rsaencrypt(rsabuf, 32, &servkey);
2221 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2223 rsaencrypt(rsabuf, 32, &hostkey);
2224 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2227 logevent("Encrypted session key");
2230 int cipher_chosen = 0, warn = 0;
2231 char *cipher_string = NULL;
2232 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2233 int next_cipher = cfg.ssh_cipherlist[i];
2234 if (next_cipher == CIPHER_WARN) {
2235 /* If/when we choose a cipher, warn about it */
2237 } else if (next_cipher == CIPHER_AES) {
2238 /* XXX Probably don't need to mention this. */
2239 logevent("AES not supported in SSH1, skipping");
2241 switch (next_cipher) {
2242 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2243 cipher_string = "3DES"; break;
2244 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2245 cipher_string = "Blowfish"; break;
2246 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2247 cipher_string = "single-DES"; break;
2249 if (supported_ciphers_mask & (1 << cipher_type))
2253 if (!cipher_chosen) {
2254 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2255 bombout(("Server violates SSH 1 protocol by not "
2256 "supporting 3DES encryption"));
2258 /* shouldn't happen */
2259 bombout(("No supported ciphers found"));
2263 /* Warn about chosen cipher if necessary. */
2265 askcipher(cipher_string, 0);
2268 switch (cipher_type) {
2269 case SSH_CIPHER_3DES:
2270 logevent("Using 3DES encryption");
2272 case SSH_CIPHER_DES:
2273 logevent("Using single-DES encryption");
2275 case SSH_CIPHER_BLOWFISH:
2276 logevent("Using Blowfish encryption");
2280 send_packet(SSH1_CMSG_SESSION_KEY,
2281 PKT_CHAR, cipher_type,
2282 PKT_DATA, cookie, 8,
2283 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2284 PKT_DATA, rsabuf, len,
2285 PKT_INT, ssh1_local_protoflags, PKT_END);
2287 logevent("Trying to enable encryption...");
2291 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2292 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
2293 cipher->sesskey(session_key);
2297 if (pktin.type != SSH1_SMSG_SUCCESS) {
2298 bombout(("Encryption not successfully enabled"));
2302 logevent("Successfully started encryption");
2306 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2307 if (ssh_get_line && !ssh_getline_pw_only) {
2308 if (!ssh_get_line("login as: ",
2309 username, sizeof(username), FALSE)) {
2311 * get_line failed to get a username.
2314 logevent("No username provided. Abandoning session.");
2315 ssh_state = SSH_STATE_CLOSED;
2320 c_write_str("login as: ");
2323 setup_userpass_input(username, sizeof(username), 1);
2325 crWaitUntil(!ispkt);
2326 ret = process_userpass_input(in, inlen);
2330 c_write_str("\r\n");
2333 strncpy(username, cfg.username, 99);
2334 username[99] = '\0';
2337 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2339 char userlog[22 + sizeof(username)];
2340 sprintf(userlog, "Sent username \"%s\"", username);
2342 if (flags & FLAG_INTERACTIVE &&
2343 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2344 strcat(userlog, "\r\n");
2345 c_write_str(userlog);
2352 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2353 /* We must not attempt PK auth. Pretend we've already tried it. */
2354 tried_publickey = tried_agent = 1;
2356 tried_publickey = tried_agent = 0;
2358 tis_auth_refused = ccard_auth_refused = 0;
2359 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2361 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2362 publickey_blob = NULL;
2364 publickey_blob = NULL;
2366 while (pktin.type == SSH1_SMSG_FAILURE) {
2367 static char password[100];
2368 static char prompt[200];
2371 static int pwpkt_type;
2372 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2374 if (agent_exists() && !tried_agent) {
2376 * Attempt RSA authentication using Pageant.
2378 static unsigned char request[5], *response, *p;
2379 static int responselen;
2380 static int i, nkeys;
2381 static int authed = FALSE;
2385 logevent("Pageant is running. Requesting keys.");
2387 /* Request the keys held by the agent. */
2388 PUT_32BIT(request, 1);
2389 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2390 agent_query(request, 5, &r, &responselen);
2391 response = (unsigned char *) r;
2392 if (response && responselen >= 5 &&
2393 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2395 nkeys = GET_32BIT(p);
2399 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2402 for (i = 0; i < nkeys; i++) {
2403 static struct RSAKey key;
2404 static Bignum challenge;
2405 static char *commentp;
2406 static int commentlen;
2410 sprintf(buf, "Trying Pageant key #%d", i);
2413 if (publickey_blob &&
2414 !memcmp(p, publickey_blob, publickey_bloblen)) {
2415 logevent("This key matches configured key file");
2416 tried_publickey = 1;
2419 p += ssh1_read_bignum(p, &key.exponent);
2420 p += ssh1_read_bignum(p, &key.modulus);
2421 commentlen = GET_32BIT(p);
2425 send_packet(SSH1_CMSG_AUTH_RSA,
2426 PKT_BIGNUM, key.modulus, PKT_END);
2428 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2429 logevent("Key refused");
2432 logevent("Received RSA challenge");
2433 ssh1_read_bignum(pktin.body, &challenge);
2435 char *agentreq, *q, *ret;
2438 len = 1 + 4; /* message type, bit count */
2439 len += ssh1_bignum_length(key.exponent);
2440 len += ssh1_bignum_length(key.modulus);
2441 len += ssh1_bignum_length(challenge);
2442 len += 16; /* session id */
2443 len += 4; /* response format */
2444 agentreq = smalloc(4 + len);
2445 PUT_32BIT(agentreq, len);
2447 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2448 PUT_32BIT(q, bignum_bitcount(key.modulus));
2450 q += ssh1_write_bignum(q, key.exponent);
2451 q += ssh1_write_bignum(q, key.modulus);
2452 q += ssh1_write_bignum(q, challenge);
2453 memcpy(q, session_id, 16);
2455 PUT_32BIT(q, 1); /* response format */
2456 agent_query(agentreq, len + 4, &vret, &retlen);
2460 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2461 logevent("Sending Pageant's response");
2462 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2463 PKT_DATA, ret + 5, 16,
2467 if (pktin.type == SSH1_SMSG_SUCCESS) {
2469 ("Pageant's response accepted");
2470 if (flags & FLAG_VERBOSE) {
2472 ("Authenticated using RSA key \"");
2473 c_write(commentp, commentlen);
2474 c_write_str("\" from agent\r\n");
2479 ("Pageant's response not accepted");
2482 ("Pageant failed to answer challenge");
2486 logevent("No reply received from Pageant");
2489 freebn(key.exponent);
2490 freebn(key.modulus);
2499 if (*cfg.keyfile && !tried_publickey)
2500 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2502 if (cfg.try_tis_auth &&
2503 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2504 !tis_auth_refused) {
2505 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2506 logevent("Requested TIS authentication");
2507 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2509 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2510 logevent("TIS authentication declined");
2511 if (flags & FLAG_INTERACTIVE)
2512 c_write_str("TIS authentication refused.\r\n");
2513 tis_auth_refused = 1;
2516 int challengelen = ((pktin.body[0] << 24) |
2517 (pktin.body[1] << 16) |
2518 (pktin.body[2] << 8) |
2520 logevent("Received TIS challenge");
2521 if (challengelen > sizeof(prompt) - 1)
2522 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2523 memcpy(prompt, pktin.body + 4, challengelen);
2524 /* Prompt heuristic comes from OpenSSH */
2525 strncpy(prompt + challengelen,
2526 memchr(prompt, '\n', challengelen) ?
2527 "": "\r\nResponse: ",
2528 (sizeof prompt) - challengelen);
2529 prompt[(sizeof prompt) - 1] = '\0';
2532 if (cfg.try_tis_auth &&
2533 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2534 !ccard_auth_refused) {
2535 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2536 logevent("Requested CryptoCard authentication");
2537 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2539 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2540 logevent("CryptoCard authentication declined");
2541 c_write_str("CryptoCard authentication refused.\r\n");
2542 ccard_auth_refused = 1;
2545 int challengelen = ((pktin.body[0] << 24) |
2546 (pktin.body[1] << 16) |
2547 (pktin.body[2] << 8) |
2549 logevent("Received CryptoCard challenge");
2550 if (challengelen > sizeof(prompt) - 1)
2551 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2552 memcpy(prompt, pktin.body + 4, challengelen);
2553 strncpy(prompt + challengelen,
2554 memchr(prompt, '\n', challengelen) ?
2555 "" : "\r\nResponse: ",
2556 sizeof(prompt) - challengelen);
2557 prompt[sizeof(prompt) - 1] = '\0';
2560 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2561 sprintf(prompt, "%.90s@%.90s's password: ",
2562 username, savedhost);
2564 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2565 char *comment = NULL;
2568 if (flags & FLAG_VERBOSE)
2569 c_write_str("Trying public key authentication.\r\n");
2570 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2572 type = key_type(cfg.keyfile);
2573 if (type != SSH_KEYTYPE_SSH1) {
2574 sprintf(msgbuf, "Key is of wrong type (%s)",
2575 key_type_to_str(type));
2577 c_write_str(msgbuf);
2578 c_write_str("\r\n");
2579 tried_publickey = 1;
2582 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2583 if (flags & FLAG_VERBOSE)
2584 c_write_str("No passphrase required.\r\n");
2587 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2592 * Show password prompt, having first obtained it via a TIS
2593 * or CryptoCard exchange if we're doing TIS or CryptoCard
2597 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2599 * get_line failed to get a password (for example
2600 * because one was supplied on the command line
2601 * which has already failed to work). Terminate.
2603 send_packet(SSH1_MSG_DISCONNECT,
2604 PKT_STR, "No more passwords available to try",
2606 logevent("Unable to authenticate");
2607 connection_fatal("Unable to authenticate");
2608 ssh_state = SSH_STATE_CLOSED;
2612 /* Prompt may have come from server. We've munged it a bit, so
2613 * we know it to be zero-terminated at least once. */
2615 c_write_untrusted(prompt, strlen(prompt));
2618 setup_userpass_input(password, sizeof(password), 0);
2620 crWaitUntil(!ispkt);
2621 ret = process_userpass_input(in, inlen);
2625 c_write_str("\r\n");
2629 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2631 * Try public key authentication with the specified
2634 static struct RSAKey pubkey;
2635 static Bignum challenge, response;
2637 static unsigned char buffer[32];
2639 tried_publickey = 1;
2640 i = loadrsakey(cfg.keyfile, &pubkey, password);
2642 c_write_str("Couldn't load private key from ");
2643 c_write_str(cfg.keyfile);
2644 c_write_str(".\r\n");
2645 continue; /* go and try password */
2648 c_write_str("Wrong passphrase.\r\n");
2649 tried_publickey = 0;
2650 continue; /* try again */
2654 * Send a public key attempt.
2656 send_packet(SSH1_CMSG_AUTH_RSA,
2657 PKT_BIGNUM, pubkey.modulus, PKT_END);
2660 if (pktin.type == SSH1_SMSG_FAILURE) {
2661 c_write_str("Server refused our public key.\r\n");
2662 continue; /* go and try password */
2664 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2665 bombout(("Bizarre response to offer of public key"));
2668 ssh1_read_bignum(pktin.body, &challenge);
2669 response = rsadecrypt(challenge, &pubkey);
2670 freebn(pubkey.private_exponent); /* burn the evidence */
2672 for (i = 0; i < 32; i++) {
2673 buffer[i] = bignum_byte(response, 31 - i);
2677 MD5Update(&md5c, buffer, 32);
2678 MD5Update(&md5c, session_id, 16);
2679 MD5Final(buffer, &md5c);
2681 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2682 PKT_DATA, buffer, 16, PKT_END);
2685 if (pktin.type == SSH1_SMSG_FAILURE) {
2686 if (flags & FLAG_VERBOSE)
2688 ("Failed to authenticate with our public key.\r\n");
2689 continue; /* go and try password */
2690 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2692 ("Bizarre response to RSA authentication response"));
2696 break; /* we're through! */
2698 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2700 * Defence against traffic analysis: we send a
2701 * whole bunch of packets containing strings of
2702 * different lengths. One of these strings is the
2703 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2704 * The others are all random data in
2705 * SSH1_MSG_IGNORE packets. This way a passive
2706 * listener can't tell which is the password, and
2707 * hence can't deduce the password length.
2709 * Anybody with a password length greater than 16
2710 * bytes is going to have enough entropy in their
2711 * password that a listener won't find it _that_
2712 * much help to know how long it is. So what we'll
2715 * - if password length < 16, we send 15 packets
2716 * containing string lengths 1 through 15
2718 * - otherwise, we let N be the nearest multiple
2719 * of 8 below the password length, and send 8
2720 * packets containing string lengths N through
2721 * N+7. This won't obscure the order of
2722 * magnitude of the password length, but it will
2723 * introduce a bit of extra uncertainty.
2725 * A few servers (the old 1.2.18 through 1.2.22)
2726 * can't deal with SSH1_MSG_IGNORE. For these
2727 * servers, we need an alternative defence. We make
2728 * use of the fact that the password is interpreted
2729 * as a C string: so we can append a NUL, then some
2732 * One server (a Cisco one) can deal with neither
2733 * SSH1_MSG_IGNORE _nor_ a padded password string.
2734 * For this server we are left with no defences
2735 * against password length sniffing.
2737 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2739 * The server can deal with SSH1_MSG_IGNORE, so
2740 * we can use the primary defence.
2742 int bottom, top, pwlen, i;
2745 pwlen = strlen(password);
2747 bottom = 0; /* zero length passwords are OK! :-) */
2750 bottom = pwlen & ~7;
2754 assert(pwlen >= bottom && pwlen <= top);
2756 randomstr = smalloc(top + 1);
2758 for (i = bottom; i <= top; i++) {
2760 defer_packet(pwpkt_type, PKT_STR, password,
2763 for (j = 0; j < i; j++) {
2765 randomstr[j] = random_byte();
2766 } while (randomstr[j] == '\0');
2768 randomstr[i] = '\0';
2769 defer_packet(SSH1_MSG_IGNORE,
2770 PKT_STR, randomstr, PKT_END);
2773 logevent("Sending password with camouflage packets");
2774 ssh_pkt_defersend();
2776 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2778 * The server can't deal with SSH1_MSG_IGNORE
2779 * but can deal with padded passwords, so we
2780 * can use the secondary defence.
2786 len = strlen(password);
2787 if (len < sizeof(string)) {
2789 strcpy(string, password);
2790 len++; /* cover the zero byte */
2791 while (len < sizeof(string)) {
2792 string[len++] = (char) random_byte();
2797 logevent("Sending length-padded password");
2798 send_packet(pwpkt_type, PKT_INT, len,
2799 PKT_DATA, s, len, PKT_END);
2802 * The server has _both_
2803 * BUG_CHOKES_ON_SSH1_IGNORE and
2804 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2805 * therefore nothing we can do.
2808 len = strlen(password);
2809 logevent("Sending unpadded password");
2810 send_packet(pwpkt_type, PKT_INT, len,
2811 PKT_DATA, password, len, PKT_END);
2814 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2817 logevent("Sent password");
2818 memset(password, 0, strlen(password));
2820 if (pktin.type == SSH1_SMSG_FAILURE) {
2821 if (flags & FLAG_VERBOSE)
2822 c_write_str("Access denied\r\n");
2823 logevent("Authentication refused");
2824 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2825 logevent("Received disconnect request");
2826 ssh_state = SSH_STATE_CLOSED;
2828 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2829 bombout(("Strange packet received, type %d", pktin.type));
2834 logevent("Authentication successful");
2839 void sshfwd_close(struct ssh_channel *c)
2841 if (c && !c->closes) {
2843 * If the channel's remoteid is -1, we have sent
2844 * CHANNEL_OPEN for this channel, but it hasn't even been
2845 * acknowledged by the server. So we must set a close flag
2846 * on it now, and then when the server acks the channel
2847 * open, we can close it then.
2849 if (((int)c->remoteid) != -1) {
2850 if (ssh_version == 1) {
2851 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2854 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2855 ssh2_pkt_adduint32(c->remoteid);
2860 if (c->type == CHAN_X11) {
2862 logevent("Forwarded X11 connection terminated");
2863 } else if (c->type == CHAN_SOCKDATA ||
2864 c->type == CHAN_SOCKDATA_DORMANT) {
2866 logevent("Forwarded port closed");
2871 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2873 if (ssh_version == 1) {
2874 send_packet(SSH1_MSG_CHANNEL_DATA,
2875 PKT_INT, c->remoteid,
2876 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2878 * In SSH1 we can return 0 here - implying that forwarded
2879 * connections are never individually throttled - because
2880 * the only circumstance that can cause throttling will be
2881 * the whole SSH connection backing up, in which case
2882 * _everything_ will be throttled as a whole.
2886 ssh2_add_channel_data(c, buf, len);
2887 return ssh2_try_send(c);
2891 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2893 if (ssh_version == 1) {
2894 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2895 c->v.v1.throttling = 0;
2899 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2903 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2909 while (!do_ssh1_login(in, inlen, ispkt)) {
2912 if (ssh_state == SSH_STATE_CLOSED)
2915 if (cfg.agentfwd && agent_exists()) {
2916 logevent("Requesting agent forwarding");
2917 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2921 if (pktin.type != SSH1_SMSG_SUCCESS
2922 && pktin.type != SSH1_SMSG_FAILURE) {
2923 bombout(("Protocol confusion"));
2925 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2926 logevent("Agent forwarding refused");
2928 logevent("Agent forwarding enabled");
2929 ssh_agentfwd_enabled = TRUE;
2933 if (cfg.x11_forward) {
2934 char proto[20], data[64];
2935 logevent("Requesting X11 forwarding");
2936 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2937 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2938 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2939 PKT_STR, proto, PKT_STR, data,
2940 PKT_INT, 0, PKT_END);
2942 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2943 PKT_STR, proto, PKT_STR, data, PKT_END);
2948 if (pktin.type != SSH1_SMSG_SUCCESS
2949 && pktin.type != SSH1_SMSG_FAILURE) {
2950 bombout(("Protocol confusion"));
2952 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2953 logevent("X11 forwarding refused");
2955 logevent("X11 forwarding enabled");
2956 ssh_X11_fwd_enabled = TRUE;
2964 int sport,dport,sserv,dserv;
2965 char sports[256], dports[256], host[256];
2969 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2970 /* Add port forwardings. */
2975 while (*e && *e != '\t')
2981 while (*e && *e != ':')
2991 dport = atoi(dports);
2995 se = getservbyname(dports, NULL);
2997 dport = ntohs(se->s_port);
3000 "Service lookup failed for destination port \"%s\"",
3005 sport = atoi(sports);
3009 se = getservbyname(sports, NULL);
3011 sport = ntohs(se->s_port);
3014 "Service lookup failed for source port \"%s\"",
3019 if (sport && dport) {
3021 pfd_addforward(host, dport, sport);
3022 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3023 " %s:%.*s%.*s%d%.*s",
3024 sserv ? strlen(sports) : 0, sports,
3025 sserv, "(", sport, sserv, ")",
3027 dserv ? strlen(dports) : 0, dports,
3028 dserv, "(", dport, dserv, ")");
3031 struct ssh_rportfwd *pf;
3032 pf = smalloc(sizeof(*pf));
3033 strcpy(pf->dhost, host);
3035 if (add234(ssh_rportfwds, pf) != pf) {
3037 "Duplicate remote port forwarding to %s:%d",
3042 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3043 " forward to %s:%.*s%.*s%d%.*s",
3044 sserv ? strlen(sports) : 0, sports,
3045 sserv, "(", sport, sserv, ")",
3047 dserv ? strlen(dports) : 0, dports,
3048 dserv, "(", dport, dserv, ")");
3050 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3058 if (pktin.type != SSH1_SMSG_SUCCESS
3059 && pktin.type != SSH1_SMSG_FAILURE) {
3060 bombout(("Protocol confusion"));
3062 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3063 c_write_str("Server refused port forwarding\r\n");
3064 ssh_editing = ssh_echoing = 1;
3066 logevent("Remote port forwarding enabled");
3074 send_packet(SSH1_CMSG_REQUEST_PTY,
3075 PKT_STR, cfg.termtype,
3076 PKT_INT, rows, PKT_INT, cols,
3077 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3078 ssh_state = SSH_STATE_INTERMED;
3082 if (pktin.type != SSH1_SMSG_SUCCESS
3083 && pktin.type != SSH1_SMSG_FAILURE) {
3084 bombout(("Protocol confusion"));
3086 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3087 c_write_str("Server refused to allocate pty\r\n");
3088 ssh_editing = ssh_echoing = 1;
3090 logevent("Allocated pty");
3092 ssh_editing = ssh_echoing = 1;
3095 if (cfg.compression) {
3096 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3100 if (pktin.type != SSH1_SMSG_SUCCESS
3101 && pktin.type != SSH1_SMSG_FAILURE) {
3102 bombout(("Protocol confusion"));
3104 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3105 c_write_str("Server refused to compress\r\n");
3107 logevent("Started compression");
3108 ssh1_compressing = TRUE;
3109 zlib_compress_init();
3110 zlib_decompress_init();
3114 * Start the shell or command.
3116 * Special case: if the first-choice command is an SSH2
3117 * subsystem (hence not usable here) and the second choice
3118 * exists, we fall straight back to that.
3121 char *cmd = cfg.remote_cmd_ptr;
3123 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3124 cmd = cfg.remote_cmd_ptr2;
3125 ssh_fallback_cmd = TRUE;
3128 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3130 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3131 logevent("Started session");
3134 ssh_state = SSH_STATE_SESSION;
3138 ssh_special(TS_EOF);
3140 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
3142 ssh_channels = newtree234(ssh_channelcmp);
3146 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
3147 pktin.type == SSH1_SMSG_STDERR_DATA) {
3148 long len = GET_32BIT(pktin.body);
3150 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3151 pktin.body + 4, len);
3152 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3153 ssh1_stdout_throttling = 1;
3156 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
3157 ssh_state = SSH_STATE_CLOSED;
3158 logevent("Received disconnect request");
3160 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3161 /* Remote side is trying to open a channel to talk to our
3162 * X-Server. Give them back a local channel number. */
3163 struct ssh_channel *c;
3165 logevent("Received X11 connect request");
3166 /* Refuse if X11 forwarding is disabled. */
3167 if (!ssh_X11_fwd_enabled) {
3168 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3169 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3170 logevent("Rejected X11 connect request");
3172 c = smalloc(sizeof(struct ssh_channel));
3174 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3175 logevent("opening X11 forward connection failed");
3177 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3178 PKT_INT, GET_32BIT(pktin.body),
3182 ("opening X11 forward connection succeeded");
3183 c->remoteid = GET_32BIT(pktin.body);
3184 c->localid = alloc_channel_id();
3186 c->v.v1.throttling = 0;
3187 c->type = CHAN_X11; /* identify channel type */
3188 add234(ssh_channels, c);
3189 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3190 PKT_INT, c->remoteid, PKT_INT,
3191 c->localid, PKT_END);
3192 logevent("Opened X11 forward channel");
3195 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3196 /* Remote side is trying to open a channel to talk to our
3197 * agent. Give them back a local channel number. */
3198 struct ssh_channel *c;
3200 /* Refuse if agent forwarding is disabled. */
3201 if (!ssh_agentfwd_enabled) {
3202 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3203 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3205 c = smalloc(sizeof(struct ssh_channel));
3206 c->remoteid = GET_32BIT(pktin.body);
3207 c->localid = alloc_channel_id();
3209 c->v.v1.throttling = 0;
3210 c->type = CHAN_AGENT; /* identify channel type */
3211 c->u.a.lensofar = 0;
3212 add234(ssh_channels, c);
3213 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3214 PKT_INT, c->remoteid, PKT_INT, c->localid,
3217 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3218 /* Remote side is trying to open a channel to talk to a
3219 * forwarded port. Give them back a local channel number. */
3220 struct ssh_channel *c;
3221 struct ssh_rportfwd pf;
3223 char host[256], buf[1024];
3225 c = smalloc(sizeof(struct ssh_channel));
3227 hostsize = GET_32BIT(pktin.body+4);
3228 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3229 if (h+1 < host+sizeof(host))
3234 port = GET_32BIT(p);
3236 strcpy(pf.dhost, host);
3239 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3240 sprintf(buf, "Rejected remote port open request for %s:%d",
3243 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3244 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3246 sprintf(buf, "Received remote port open request for %s:%d",
3249 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3252 sprintf(buf, "Port open failed: %s", e);
3255 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3256 PKT_INT, GET_32BIT(pktin.body),
3259 c->remoteid = GET_32BIT(pktin.body);
3260 c->localid = alloc_channel_id();
3262 c->v.v1.throttling = 0;
3263 c->type = CHAN_SOCKDATA; /* identify channel type */
3264 add234(ssh_channels, c);
3265 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3266 PKT_INT, c->remoteid, PKT_INT,
3267 c->localid, PKT_END);
3268 logevent("Forwarded port opened successfully");
3272 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3273 unsigned int remoteid = GET_32BIT(pktin.body);
3274 unsigned int localid = GET_32BIT(pktin.body+4);
3275 struct ssh_channel *c;
3277 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3278 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3279 c->remoteid = localid;
3280 c->type = CHAN_SOCKDATA;
3281 c->v.v1.throttling = 0;
3282 pfd_confirm(c->u.pfd.s);
3285 if (c && c->closes) {
3287 * We have a pending close on this channel,
3288 * which we decided on before the server acked
3289 * the channel open. So now we know the
3290 * remoteid, we can close it again.
3292 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3296 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3297 unsigned int remoteid = GET_32BIT(pktin.body);
3298 unsigned int localid = GET_32BIT(pktin.body+4);
3299 struct ssh_channel *c;
3301 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3302 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3303 logevent("Forwarded connection refused by server");
3304 pfd_close(c->u.pfd.s);
3305 del234(ssh_channels, c);
3309 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3310 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3311 /* Remote side closes a channel. */
3312 unsigned i = GET_32BIT(pktin.body);
3313 struct ssh_channel *c;
3314 c = find234(ssh_channels, &i, ssh_channelfind);
3318 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3319 if (!(c->closes & closetype))
3320 send_packet(pktin.type, PKT_INT, c->remoteid,
3322 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3323 logevent("Forwarded X11 connection terminated");
3324 assert(c->u.x11.s != NULL);
3325 x11_close(c->u.x11.s);
3328 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3329 logevent("Forwarded port closed");
3330 assert(c->u.pfd.s != NULL);
3331 pfd_close(c->u.pfd.s);
3334 c->closes |= closetype;
3335 if (c->closes == 3) {
3336 del234(ssh_channels, c);
3340 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3341 /* Data sent down one of our channels. */
3342 int i = GET_32BIT(pktin.body);
3343 int len = GET_32BIT(pktin.body + 4);
3344 unsigned char *p = pktin.body + 8;
3345 struct ssh_channel *c;
3346 c = find234(ssh_channels, &i, ssh_channelfind);
3351 bufsize = x11_send(c->u.x11.s, p, len);
3354 bufsize = pfd_send(c->u.pfd.s, p, len);
3357 /* Data for an agent message. Buffer it. */
3359 if (c->u.a.lensofar < 4) {
3360 int l = min(4 - c->u.a.lensofar, len);
3361 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3365 c->u.a.lensofar += l;
3367 if (c->u.a.lensofar == 4) {
3369 4 + GET_32BIT(c->u.a.msglen);
3370 c->u.a.message = smalloc(c->u.a.totallen);
3371 memcpy(c->u.a.message, c->u.a.msglen, 4);
3373 if (c->u.a.lensofar >= 4 && len > 0) {
3375 min(c->u.a.totallen - c->u.a.lensofar,
3377 memcpy(c->u.a.message + c->u.a.lensofar, p,
3381 c->u.a.lensofar += l;
3383 if (c->u.a.lensofar == c->u.a.totallen) {
3384 void *reply, *sentreply;
3386 agent_query(c->u.a.message,
3387 c->u.a.totallen, &reply,
3392 /* Fake SSH_AGENT_FAILURE. */
3393 sentreply = "\0\0\0\1\5";
3396 send_packet(SSH1_MSG_CHANNEL_DATA,
3397 PKT_INT, c->remoteid,
3399 PKT_DATA, sentreply, replylen,
3403 sfree(c->u.a.message);
3404 c->u.a.lensofar = 0;
3407 bufsize = 0; /* agent channels never back up */
3410 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3411 c->v.v1.throttling = 1;
3415 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3416 /* may be from EXEC_SHELL on some servers */
3417 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3418 /* may be from EXEC_SHELL on some servers
3419 * if no pty is available or in other odd cases. Ignore */
3420 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3422 ssh_exitcode = GET_32BIT(pktin.body);
3423 sprintf(buf, "Server sent command exit status %d",
3426 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3428 * In case `helpful' firewalls or proxies tack
3429 * extra human-readable text on the end of the
3430 * session which we might mistake for another
3431 * encrypted packet, we close the session once
3432 * we've sent EXIT_CONFIRMATION.
3434 ssh_state = SSH_STATE_CLOSED;
3437 bombout(("Strange packet received: type %d", pktin.type));
3442 int len = min(inlen, 512);
3443 send_packet(SSH1_CMSG_STDIN_DATA,
3444 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3455 * Utility routine for decoding comma-separated strings in KEXINIT.
3457 static int in_commasep_string(char *needle, char *haystack, int haylen)
3459 int needlen = strlen(needle);
3462 * Is it at the start of the string?
3464 if (haylen >= needlen && /* haystack is long enough */
3465 !memcmp(needle, haystack, needlen) && /* initial match */
3466 (haylen == needlen || haystack[needlen] == ',')
3467 /* either , or EOS follows */
3471 * If not, search for the next comma and resume after that.
3472 * If no comma found, terminate.
3474 while (haylen > 0 && *haystack != ',')
3475 haylen--, haystack++;
3478 haylen--, haystack++; /* skip over comma itself */
3483 * SSH2 key creation method.
3485 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3489 /* First 20 bytes. */
3492 SHA_Bytes(&s, H, 20);
3493 SHA_Bytes(&s, &chr, 1);
3494 SHA_Bytes(&s, sessid, 20);
3495 SHA_Final(&s, keyspace);
3496 /* Next 20 bytes. */
3499 SHA_Bytes(&s, H, 20);
3500 SHA_Bytes(&s, keyspace, 20);
3501 SHA_Final(&s, keyspace + 20);
3505 * Handle the SSH2 transport layer.
3507 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3509 static int i, j, len, nbits, pbits, warn;
3511 static Bignum p, g, e, f, K;
3512 static int kex_init_value, kex_reply_value;
3513 static const struct ssh_mac **maclist;
3515 static const struct ssh2_cipher *cscipher_tobe = NULL;
3516 static const struct ssh2_cipher *sccipher_tobe = NULL;
3517 static const struct ssh_mac *csmac_tobe = NULL;
3518 static const struct ssh_mac *scmac_tobe = NULL;
3519 static const struct ssh_compress *cscomp_tobe = NULL;
3520 static const struct ssh_compress *sccomp_tobe = NULL;
3521 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3522 static int hostkeylen, siglen;
3523 static void *hkey; /* actual host key */
3524 static unsigned char exchange_hash[20];
3525 static unsigned char keyspace[40];
3526 static int n_preferred_ciphers;
3527 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3528 static const struct ssh_compress *preferred_comp;
3529 static int cipherstr_started;
3530 static int first_kex;
3537 * Set up the preferred ciphers. (NULL => warn below here)
3539 n_preferred_ciphers = 0;
3540 for (i = 0; i < CIPHER_MAX; i++) {
3541 switch (cfg.ssh_cipherlist[i]) {
3542 case CIPHER_BLOWFISH:
3543 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3544 n_preferred_ciphers++;
3547 if (cfg.ssh2_des_cbc) {
3548 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3549 n_preferred_ciphers++;
3553 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3554 n_preferred_ciphers++;
3557 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3558 n_preferred_ciphers++;
3561 /* Flag for later. Don't bother if it's the last in
3563 if (i < CIPHER_MAX - 1) {
3564 preferred_ciphers[n_preferred_ciphers] = NULL;
3565 n_preferred_ciphers++;
3572 * Set up preferred compression.
3574 if (cfg.compression)
3575 preferred_comp = &ssh_zlib;
3577 preferred_comp = &ssh_comp_none;
3580 * Be prepared to work around the buggy MAC problem.
3582 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3583 maclist = buggymacs, nmacs = lenof(buggymacs);
3585 maclist = macs, nmacs = lenof(macs);
3589 * Construct and send our key exchange packet.
3591 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3592 for (i = 0; i < 16; i++)
3593 ssh2_pkt_addbyte((unsigned char) random_byte());
3594 /* List key exchange algorithms. */
3595 ssh2_pkt_addstring_start();
3596 for (i = 0; i < lenof(kex_algs); i++) {
3597 ssh2_pkt_addstring_str(kex_algs[i]->name);
3598 if (i < lenof(kex_algs) - 1)
3599 ssh2_pkt_addstring_str(",");
3601 /* List server host key algorithms. */
3602 ssh2_pkt_addstring_start();
3603 for (i = 0; i < lenof(hostkey_algs); i++) {
3604 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3605 if (i < lenof(hostkey_algs) - 1)
3606 ssh2_pkt_addstring_str(",");
3608 /* List client->server encryption algorithms. */
3609 ssh2_pkt_addstring_start();
3610 cipherstr_started = 0;
3611 for (i = 0; i < n_preferred_ciphers; i++) {
3612 const struct ssh2_ciphers *c = preferred_ciphers[i];
3613 if (!c) continue; /* warning flag */
3614 for (j = 0; j < c->nciphers; j++) {
3615 if (cipherstr_started)
3616 ssh2_pkt_addstring_str(",");
3617 ssh2_pkt_addstring_str(c->list[j]->name);
3618 cipherstr_started = 1;
3621 /* List server->client encryption algorithms. */
3622 ssh2_pkt_addstring_start();
3623 cipherstr_started = 0;
3624 for (i = 0; i < n_preferred_ciphers; i++) {
3625 const struct ssh2_ciphers *c = preferred_ciphers[i];
3626 if (!c) continue; /* warning flag */
3627 for (j = 0; j < c->nciphers; j++) {
3628 if (cipherstr_started)
3629 ssh2_pkt_addstring_str(",");
3630 ssh2_pkt_addstring_str(c->list[j]->name);
3631 cipherstr_started = 1;
3634 /* List client->server MAC algorithms. */
3635 ssh2_pkt_addstring_start();
3636 for (i = 0; i < nmacs; i++) {
3637 ssh2_pkt_addstring_str(maclist[i]->name);
3639 ssh2_pkt_addstring_str(",");
3641 /* List server->client MAC algorithms. */
3642 ssh2_pkt_addstring_start();
3643 for (i = 0; i < nmacs; i++) {
3644 ssh2_pkt_addstring_str(maclist[i]->name);
3646 ssh2_pkt_addstring_str(",");
3648 /* List client->server compression algorithms. */
3649 ssh2_pkt_addstring_start();
3650 for (i = 0; i < lenof(compressions) + 1; i++) {
3651 const struct ssh_compress *c =
3652 i == 0 ? preferred_comp : compressions[i - 1];
3653 ssh2_pkt_addstring_str(c->name);
3654 if (i < lenof(compressions))
3655 ssh2_pkt_addstring_str(",");
3657 /* List server->client compression algorithms. */
3658 ssh2_pkt_addstring_start();
3659 for (i = 0; i < lenof(compressions) + 1; i++) {
3660 const struct ssh_compress *c =
3661 i == 0 ? preferred_comp : compressions[i - 1];
3662 ssh2_pkt_addstring_str(c->name);
3663 if (i < lenof(compressions))
3664 ssh2_pkt_addstring_str(",");
3666 /* List client->server languages. Empty list. */
3667 ssh2_pkt_addstring_start();
3668 /* List server->client languages. Empty list. */
3669 ssh2_pkt_addstring_start();
3670 /* First KEX packet does _not_ follow, because we're not that brave. */
3671 ssh2_pkt_addbool(FALSE);
3673 ssh2_pkt_adduint32(0);
3675 exhash = exhashbase;
3676 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3682 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3685 * Now examine the other side's KEXINIT to see what we're up
3688 if (pktin.type != SSH2_MSG_KEXINIT) {
3689 bombout(("expected key exchange packet from server"));
3694 cscipher_tobe = NULL;
3695 sccipher_tobe = NULL;
3700 pktin.savedpos += 16; /* skip garbage cookie */
3701 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3702 for (i = 0; i < lenof(kex_algs); i++) {
3703 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3708 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3709 for (i = 0; i < lenof(hostkey_algs); i++) {
3710 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3711 hostkey = hostkey_algs[i];
3715 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3717 for (i = 0; i < n_preferred_ciphers; i++) {
3718 const struct ssh2_ciphers *c = preferred_ciphers[i];
3722 for (j = 0; j < c->nciphers; j++) {
3723 if (in_commasep_string(c->list[j]->name, str, len)) {
3724 cscipher_tobe = c->list[j];
3729 if (cscipher_tobe) {
3731 askcipher(cscipher_tobe->name, 1);
3735 if (!cscipher_tobe) {
3736 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3740 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3742 for (i = 0; i < n_preferred_ciphers; i++) {
3743 const struct ssh2_ciphers *c = preferred_ciphers[i];
3747 for (j = 0; j < c->nciphers; j++) {
3748 if (in_commasep_string(c->list[j]->name, str, len)) {
3749 sccipher_tobe = c->list[j];
3754 if (sccipher_tobe) {
3756 askcipher(sccipher_tobe->name, 2);
3760 if (!sccipher_tobe) {
3761 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3765 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3766 for (i = 0; i < nmacs; i++) {
3767 if (in_commasep_string(maclist[i]->name, str, len)) {
3768 csmac_tobe = maclist[i];
3772 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3773 for (i = 0; i < nmacs; i++) {
3774 if (in_commasep_string(maclist[i]->name, str, len)) {
3775 scmac_tobe = maclist[i];
3779 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3780 for (i = 0; i < lenof(compressions) + 1; i++) {
3781 const struct ssh_compress *c =
3782 i == 0 ? preferred_comp : compressions[i - 1];
3783 if (in_commasep_string(c->name, str, len)) {
3788 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3789 for (i = 0; i < lenof(compressions) + 1; i++) {
3790 const struct ssh_compress *c =
3791 i == 0 ? preferred_comp : compressions[i - 1];
3792 if (in_commasep_string(c->name, str, len)) {
3799 * Work out the number of bits of key we will need from the key
3800 * exchange. We start with the maximum key length of either
3806 csbits = cscipher_tobe->keylen;
3807 scbits = sccipher_tobe->keylen;
3808 nbits = (csbits > scbits ? csbits : scbits);
3810 /* The keys only have 160-bit entropy, since they're based on
3811 * a SHA-1 hash. So cap the key size at 160 bits. */
3816 * If we're doing Diffie-Hellman group exchange, start by
3817 * requesting a group.
3819 if (kex == &ssh_diffiehellman_gex) {
3820 logevent("Doing Diffie-Hellman group exchange");
3821 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
3823 * Work out how big a DH group we will need to allow that
3826 pbits = 512 << ((nbits - 1) / 64);
3827 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3828 ssh2_pkt_adduint32(pbits);
3832 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3833 bombout(("expected key exchange group packet from server"));
3836 p = ssh2_pkt_getmp();
3837 g = ssh2_pkt_getmp();
3838 dh_setup_group(p, g);
3839 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3840 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3842 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3844 kex_init_value = SSH2_MSG_KEXDH_INIT;
3845 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3848 logevent("Doing Diffie-Hellman key exchange");
3850 * Now generate and send e for Diffie-Hellman.
3852 e = dh_create_e(nbits * 2);
3853 ssh2_pkt_init(kex_init_value);
3858 if (pktin.type != kex_reply_value) {
3859 bombout(("expected key exchange reply packet from server"));
3862 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3863 f = ssh2_pkt_getmp();
3864 ssh2_pkt_getstring(&sigdata, &siglen);
3868 sha_string(&exhash, hostkeydata, hostkeylen);
3869 if (kex == &ssh_diffiehellman_gex) {
3870 sha_uint32(&exhash, pbits);
3871 sha_mpint(&exhash, p);
3872 sha_mpint(&exhash, g);
3874 sha_mpint(&exhash, e);
3875 sha_mpint(&exhash, f);
3876 sha_mpint(&exhash, K);
3877 SHA_Final(&exhash, exchange_hash);
3882 debug(("Exchange hash is:\n"));
3883 dmemdump(exchange_hash, 20);
3886 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3888 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3889 bombout(("Server's host key did not match the signature supplied"));
3894 * Authenticate remote host: verify host key. (We've already
3895 * checked the signature of the exchange hash.)
3897 keystr = hostkey->fmtkey(hkey);
3898 fingerprint = hostkey->fingerprint(hkey);
3899 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3900 keystr, fingerprint);
3901 if (first_kex) { /* don't bother logging this in rekeys */
3902 logevent("Host key fingerprint is:");
3903 logevent(fingerprint);
3907 hostkey->freekey(hkey);
3910 * Send SSH2_MSG_NEWKEYS.
3912 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3916 * Expect SSH2_MSG_NEWKEYS from server.
3919 if (pktin.type != SSH2_MSG_NEWKEYS) {
3920 bombout(("expected new-keys packet from server"));
3925 * Create and initialise session keys.
3927 cscipher = cscipher_tobe;
3928 sccipher = sccipher_tobe;
3931 cscomp = cscomp_tobe;
3932 sccomp = sccomp_tobe;
3933 cscomp->compress_init();
3934 sccomp->decompress_init();
3936 * Set IVs after keys. Here we use the exchange hash from the
3937 * _first_ key exchange.
3940 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3941 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3942 cscipher->setcskey(keyspace);
3943 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3944 sccipher->setsckey(keyspace);
3945 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3946 cscipher->setcsiv(keyspace);
3947 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3948 sccipher->setsciv(keyspace);
3949 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3950 csmac->setcskey(keyspace);
3951 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3952 scmac->setsckey(keyspace);
3955 * If this is the first key exchange phase, we must pass the
3956 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3957 * wants to see it but because it will need time to initialise
3958 * itself before it sees an actual packet. In subsequent key
3959 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3960 * it would only confuse the layer above.
3968 * Now we're encrypting. Begin returning 1 to the protocol main
3969 * function so that other things can run on top of the
3970 * transport. If we ever see a KEXINIT, we must go back to the
3973 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3976 logevent("Server initiated key re-exchange");
3977 goto begin_key_exchange;
3983 * Add data to an SSH2 channel output buffer.
3985 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3988 bufchain_add(&c->v.v2.outbuffer, buf, len);
3992 * Attempt to send data on an SSH2 channel.
3994 static int ssh2_try_send(struct ssh_channel *c)
3996 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3999 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4000 if ((unsigned)len > c->v.v2.remwindow)
4001 len = c->v.v2.remwindow;
4002 if ((unsigned)len > c->v.v2.remmaxpkt)
4003 len = c->v.v2.remmaxpkt;
4004 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4005 ssh2_pkt_adduint32(c->remoteid);
4006 ssh2_pkt_addstring_start();
4007 ssh2_pkt_addstring_data(data, len);
4009 bufchain_consume(&c->v.v2.outbuffer, len);
4010 c->v.v2.remwindow -= len;
4014 * After having sent as much data as we can, return the amount
4017 return bufchain_size(&c->v.v2.outbuffer);
4021 * Potentially enlarge the window on an SSH2 channel.
4023 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4026 * Never send WINDOW_ADJUST for a channel that the remote side
4027 * already thinks it's closed; there's no point, since it won't
4028 * be sending any more data anyway.
4033 if (newwin > c->v.v2.locwindow) {
4034 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4035 ssh2_pkt_adduint32(c->remoteid);
4036 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4038 c->v.v2.locwindow = newwin;
4043 * Handle the SSH2 userauth and connection layers.
4045 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4048 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4050 AUTH_KEYBOARD_INTERACTIVE
4054 AUTH_TYPE_PUBLICKEY,
4055 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4056 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4058 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4059 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4061 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4062 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
4063 static int kbd_inter_running;
4064 static int we_are_in;
4065 static int num_prompts, curr_prompt, echo;
4066 static char username[100];
4067 static int got_username;
4068 static char pwprompt[200];
4069 static char password[100];
4070 static void *publickey_blob;
4071 static int publickey_bloblen;
4076 * Request userauth protocol, and await a response to it.
4078 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4079 ssh2_pkt_addstring("ssh-userauth");
4081 crWaitUntilV(ispkt);
4082 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4083 bombout(("Server refused user authentication protocol"));
4088 * We repeat this whole loop, including the username prompt,
4089 * until we manage a successful authentication. If the user
4090 * types the wrong _password_, they are sent back to the
4091 * beginning to try another username. (If they specify a
4092 * username in the config, they are never asked, even if they
4093 * do give a wrong password.)
4095 * I think this best serves the needs of
4097 * - the people who have no configuration, no keys, and just
4098 * want to try repeated (username,password) pairs until they
4099 * type both correctly
4101 * - people who have keys and configuration but occasionally
4102 * need to fall back to passwords
4104 * - people with a key held in Pageant, who might not have
4105 * logged in to a particular machine before; so they want to
4106 * type a username, and then _either_ their key will be
4107 * accepted, _or_ they will type a password. If they mistype
4108 * the username they will want to be able to get back and
4112 got_username = FALSE;
4117 if (got_username && !cfg.change_username) {
4119 * We got a username last time round this loop, and
4120 * with change_username turned off we don't try to get
4123 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4124 if (ssh_get_line && !ssh_getline_pw_only) {
4125 if (!ssh_get_line("login as: ",
4126 username, sizeof(username), FALSE)) {
4128 * get_line failed to get a username.
4131 logevent("No username provided. Abandoning session.");
4132 ssh_state = SSH_STATE_CLOSED;
4137 c_write_str("login as: ");
4139 setup_userpass_input(username, sizeof(username), 1);
4141 crWaitUntilV(!ispkt);
4142 ret = process_userpass_input(in, inlen);
4147 c_write_str("\r\n");
4148 username[strcspn(username, "\n\r")] = '\0';
4151 strncpy(username, cfg.username, 99);
4152 username[99] = '\0';
4153 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4154 sprintf(stuff, "Using username \"%s\".\r\n", username);
4158 got_username = TRUE;
4161 * Send an authentication request using method "none": (a)
4162 * just in case it succeeds, and (b) so that we know what
4163 * authentication methods we can usefully try next.
4165 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4167 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4168 ssh2_pkt_addstring(username);
4169 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4170 ssh2_pkt_addstring("none"); /* method */
4172 type = AUTH_TYPE_NONE;
4176 tried_pubkey_config = FALSE;
4177 tried_agent = FALSE;
4178 tried_keyb_inter = FALSE;
4179 kbd_inter_running = FALSE;
4180 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4183 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4184 keytype = key_type(cfg.keyfile);
4185 if (keytype == SSH_KEYTYPE_SSH2)
4186 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4187 &publickey_bloblen);
4190 logeventf("Unable to use this key file (%s)",
4191 key_type_to_str(keytype));
4192 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4193 cfg.keyfile, key_type_to_str(keytype));
4194 c_write_str(msgbuf);
4195 publickey_blob = NULL;
4198 publickey_blob = NULL;
4202 * Wait for the result of the last authentication request.
4205 crWaitUntilV(ispkt);
4206 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4210 * Don't show the banner if we're operating in
4211 * non-verbose non-interactive mode. (It's probably
4212 * a script, which means nobody will read the
4213 * banner _anyway_, and moreover the printing of
4214 * the banner will screw up processing on the
4215 * output of (say) plink.)
4217 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4218 ssh2_pkt_getstring(&banner, &size);
4220 c_write_untrusted(banner, size);
4222 crWaitUntilV(ispkt);
4224 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4225 logevent("Access granted");
4230 if (kbd_inter_running &&
4231 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4233 * This is either a further set-of-prompts packet
4234 * in keyboard-interactive authentication, or it's
4235 * the same one and we came back here with `gotit'
4236 * set. In the former case, we must reset the
4237 * curr_prompt variable.
4241 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4242 bombout(("Strange packet received during authentication: type %d",
4250 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4251 * we can look at the string in it and know what we can
4252 * helpfully try next.
4254 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4257 ssh2_pkt_getstring(&methods, &methlen);
4258 kbd_inter_running = FALSE;
4259 if (!ssh2_pkt_getbool()) {
4261 * We have received an unequivocal Access
4262 * Denied. This can translate to a variety of
4265 * - if we'd just tried "none" authentication,
4266 * it's not worth printing anything at all
4268 * - if we'd just tried a public key _offer_,
4269 * the message should be "Server refused our
4270 * key" (or no message at all if the key
4271 * came from Pageant)
4273 * - if we'd just tried anything else, the
4274 * message really should be "Access denied".
4276 * Additionally, if we'd just tried password
4277 * authentication, we should break out of this
4278 * whole loop so as to go back to the username
4281 if (type == AUTH_TYPE_NONE) {
4283 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4284 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4285 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4286 c_write_str("Server refused our key\r\n");
4287 logevent("Server refused public key");
4288 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4289 /* server declined keyboard-interactive; ignore */
4291 c_write_str("Access denied\r\n");
4292 logevent("Access denied");
4293 if (type == AUTH_TYPE_PASSWORD) {
4299 c_write_str("Further authentication required\r\n");
4300 logevent("Further authentication required");
4304 in_commasep_string("publickey", methods, methlen);
4306 in_commasep_string("password", methods, methlen);
4307 can_keyb_inter = cfg.try_ki_auth &&
4308 in_commasep_string("keyboard-interactive", methods, methlen);
4312 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4315 * Most password/passphrase prompts will be
4316 * non-echoing, so we set this to 0 by default.
4317 * Exception is that some keyboard-interactive prompts
4318 * can be echoing, in which case we'll set this to 1.
4322 if (!method && can_pubkey && agent_exists() && !tried_agent) {
4324 * Attempt public-key authentication using Pageant.
4326 static unsigned char request[5], *response, *p;
4327 static int responselen;
4328 static int i, nkeys;
4329 static int authed = FALSE;
4332 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4333 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4337 logevent("Pageant is running. Requesting keys.");
4339 /* Request the keys held by the agent. */
4340 PUT_32BIT(request, 1);
4341 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4342 agent_query(request, 5, &r, &responselen);
4343 response = (unsigned char *) r;
4344 if (response && responselen >= 5 &&
4345 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4347 nkeys = GET_32BIT(p);
4351 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4354 for (i = 0; i < nkeys; i++) {
4355 static char *pkblob, *alg, *commentp;
4356 static int pklen, alglen, commentlen;
4357 static int siglen, retlen, len;
4358 static char *q, *agentreq, *ret;
4363 sprintf(buf, "Trying Pageant key #%d", i);
4366 pklen = GET_32BIT(p);
4368 if (publickey_blob &&
4369 pklen == publickey_bloblen &&
4370 !memcmp(p, publickey_blob, publickey_bloblen)) {
4371 logevent("This key matches configured key file");
4372 tried_pubkey_config = 1;
4376 alglen = GET_32BIT(pkblob);
4378 commentlen = GET_32BIT(p);
4382 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4383 ssh2_pkt_addstring(username);
4384 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4385 ssh2_pkt_addstring("publickey"); /* method */
4386 ssh2_pkt_addbool(FALSE); /* no signature included */
4387 ssh2_pkt_addstring_start();
4388 ssh2_pkt_addstring_data(alg, alglen);
4389 ssh2_pkt_addstring_start();
4390 ssh2_pkt_addstring_data(pkblob, pklen);
4393 crWaitUntilV(ispkt);
4394 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4395 logevent("Key refused");
4399 if (flags & FLAG_VERBOSE) {
4401 ("Authenticating with public key \"");
4402 c_write(commentp, commentlen);
4403 c_write_str("\" from agent\r\n");
4407 * Server is willing to accept the key.
4408 * Construct a SIGN_REQUEST.
4410 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4411 ssh2_pkt_addstring(username);
4412 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4413 ssh2_pkt_addstring("publickey"); /* method */
4414 ssh2_pkt_addbool(TRUE);
4415 ssh2_pkt_addstring_start();
4416 ssh2_pkt_addstring_data(alg, alglen);
4417 ssh2_pkt_addstring_start();
4418 ssh2_pkt_addstring_data(pkblob, pklen);
4420 siglen = pktout.length - 5 + 4 + 20;
4421 len = 1; /* message type */
4422 len += 4 + pklen; /* key blob */
4423 len += 4 + siglen; /* data to sign */
4424 len += 4; /* flags */
4425 agentreq = smalloc(4 + len);
4426 PUT_32BIT(agentreq, len);
4428 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4429 PUT_32BIT(q, pklen);
4431 memcpy(q, pkblob, pklen);
4433 PUT_32BIT(q, siglen);
4435 /* Now the data to be signed... */
4438 memcpy(q, ssh2_session_id, 20);
4440 memcpy(q, pktout.data + 5, pktout.length - 5);
4441 q += pktout.length - 5;
4442 /* And finally the (zero) flags word. */
4444 agent_query(agentreq, len + 4, &vret, &retlen);
4448 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4449 logevent("Sending Pageant's response");
4450 ssh2_add_sigblob(pkblob, pklen,
4451 ret + 9, GET_32BIT(ret + 5));
4457 ("Pageant failed to answer challenge");
4467 if (!method && can_pubkey && publickey_blob
4468 && !tried_pubkey_config) {
4469 unsigned char *pub_blob;
4470 char *algorithm, *comment;
4473 tried_pubkey_config = TRUE;
4475 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4476 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4479 * Try the public key supplied in the configuration.
4481 * First, offer the public blob to see if the server is
4482 * willing to accept it.
4484 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4487 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4488 ssh2_pkt_addstring(username);
4489 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4490 ssh2_pkt_addstring("publickey"); /* method */
4491 ssh2_pkt_addbool(FALSE); /* no signature included */
4492 ssh2_pkt_addstring(algorithm);
4493 ssh2_pkt_addstring_start();
4494 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4496 logevent("Offered public key"); /* FIXME */
4498 crWaitUntilV(ispkt);
4499 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4501 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4502 continue; /* key refused; give up on it */
4505 logevent("Offer of public key accepted");
4507 * Actually attempt a serious authentication using
4510 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4512 "Passphrase for key \"%.100s\": ",
4518 c_write_str("Authenticating with public key \"");
4519 c_write_str(comment);
4520 c_write_str("\"\r\n");
4521 method = AUTH_PUBLICKEY_FILE;
4525 if (!method && can_keyb_inter && !tried_keyb_inter) {
4526 method = AUTH_KEYBOARD_INTERACTIVE;
4527 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4528 tried_keyb_inter = TRUE;
4530 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4531 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4533 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4534 ssh2_pkt_addstring(username);
4535 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4536 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4537 ssh2_pkt_addstring(""); /* lang */
4538 ssh2_pkt_addstring("");
4541 crWaitUntilV(ispkt);
4542 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4543 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4545 logevent("Keyboard-interactive authentication refused");
4546 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4550 kbd_inter_running = TRUE;
4554 if (kbd_inter_running) {
4555 method = AUTH_KEYBOARD_INTERACTIVE;
4556 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4557 tried_keyb_inter = TRUE;
4559 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4560 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4562 if (curr_prompt == 0) {
4564 * We've got a fresh USERAUTH_INFO_REQUEST.
4565 * Display header data, and start going through
4568 char *name, *inst, *lang;
4569 int name_len, inst_len, lang_len;
4571 ssh2_pkt_getstring(&name, &name_len);
4572 ssh2_pkt_getstring(&inst, &inst_len);
4573 ssh2_pkt_getstring(&lang, &lang_len);
4575 c_write_untrusted(name, name_len);
4576 c_write_str("\r\n");
4579 c_write_untrusted(inst, inst_len);
4580 c_write_str("\r\n");
4582 num_prompts = ssh2_pkt_getuint32();
4586 * If there are prompts remaining in the packet,
4587 * display one and get a response.
4589 if (curr_prompt < num_prompts) {
4593 ssh2_pkt_getstring(&prompt, &prompt_len);
4594 if (prompt_len > 0) {
4595 strncpy(pwprompt, prompt, sizeof(pwprompt));
4596 pwprompt[prompt_len < sizeof(pwprompt) ?
4597 prompt_len : sizeof(pwprompt)-1] = '\0';
4600 "<server failed to send prompt>: ");
4602 echo = ssh2_pkt_getbool();
4608 if (!method && can_passwd) {
4609 method = AUTH_PASSWORD;
4610 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4611 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4612 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4619 if (!ssh_get_line(pwprompt, password,
4620 sizeof(password), TRUE)) {
4622 * get_line failed to get a password (for
4623 * example because one was supplied on the
4624 * command line which has already failed to
4627 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4628 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4630 ("No more passwords available to try");
4631 ssh2_pkt_addstring("en"); /* language tag */
4633 logevent("Unable to authenticate");
4634 connection_fatal("Unable to authenticate");
4635 ssh_state = SSH_STATE_CLOSED;
4640 c_write_untrusted(pwprompt, strlen(pwprompt));
4643 setup_userpass_input(password, sizeof(password), echo);
4645 crWaitUntilV(!ispkt);
4646 ret = process_userpass_input(in, inlen);
4650 c_write_str("\r\n");
4654 if (method == AUTH_PUBLICKEY_FILE) {
4656 * We have our passphrase. Now try the actual authentication.
4658 struct ssh2_userkey *key;
4660 key = ssh2_load_userkey(cfg.keyfile, password);
4661 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4662 if (key == SSH2_WRONG_PASSPHRASE) {
4663 c_write_str("Wrong passphrase\r\n");
4664 tried_pubkey_config = FALSE;
4666 c_write_str("Unable to load private key\r\n");
4667 tried_pubkey_config = TRUE;
4669 /* Send a spurious AUTH_NONE to return to the top. */
4670 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4671 ssh2_pkt_addstring(username);
4672 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4673 ssh2_pkt_addstring("none"); /* method */
4675 type = AUTH_TYPE_NONE;
4677 unsigned char *pkblob, *sigblob, *sigdata;
4678 int pkblob_len, sigblob_len, sigdata_len;
4681 * We have loaded the private key and the server
4682 * has announced that it's willing to accept it.
4683 * Hallelujah. Generate a signature and send it.
4685 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4686 ssh2_pkt_addstring(username);
4687 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4688 ssh2_pkt_addstring("publickey"); /* method */
4689 ssh2_pkt_addbool(TRUE);
4690 ssh2_pkt_addstring(key->alg->name);
4691 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4692 ssh2_pkt_addstring_start();
4693 ssh2_pkt_addstring_data(pkblob, pkblob_len);
4696 * The data to be signed is:
4700 * followed by everything so far placed in the
4703 sigdata_len = pktout.length - 5 + 4 + 20;
4704 sigdata = smalloc(sigdata_len);
4705 PUT_32BIT(sigdata, 20);
4706 memcpy(sigdata + 4, ssh2_session_id, 20);
4707 memcpy(sigdata + 24, pktout.data + 5,
4709 sigblob = key->alg->sign(key->data, sigdata,
4710 sigdata_len, &sigblob_len);
4711 ssh2_add_sigblob(pkblob, pkblob_len,
4712 sigblob, sigblob_len);
4718 type = AUTH_TYPE_PUBLICKEY;
4720 } else if (method == AUTH_PASSWORD) {
4722 * We send the password packet lumped tightly together with
4723 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4724 * string long enough to make the total length of the two
4725 * packets constant. This should ensure that a passive
4726 * listener doing traffic analyis can't work out the length
4729 * For this to work, we need an assumption about the
4730 * maximum length of the password packet. I think 256 is
4731 * pretty conservative. Anyone using a password longer than
4732 * that probably doesn't have much to worry about from
4733 * people who find out how long their password is!
4735 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4736 ssh2_pkt_addstring(username);
4737 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4738 ssh2_pkt_addstring("password");
4739 ssh2_pkt_addbool(FALSE);
4740 ssh2_pkt_addstring(password);
4743 * We'll include a string that's an exact multiple of the
4744 * cipher block size. If the cipher is NULL for some
4745 * reason, we don't do this trick at all because we gain
4751 stringlen = (256 - deferred_len);
4752 stringlen += cscipher->blksize - 1;
4753 stringlen -= (stringlen % cscipher->blksize);
4756 * Temporarily disable actual compression,
4757 * so we can guarantee to get this string
4758 * exactly the length we want it. The
4759 * compression-disabling routine should
4760 * return an integer indicating how many
4761 * bytes we should adjust our string length
4764 stringlen -= cscomp->disable_compression();
4766 ssh2_pkt_init(SSH2_MSG_IGNORE);
4767 ssh2_pkt_addstring_start();
4768 for (i = 0; i < stringlen; i++) {
4769 char c = (char) random_byte();
4770 ssh2_pkt_addstring_data(&c, 1);
4774 ssh_pkt_defersend();
4775 logevent("Sent password");
4776 type = AUTH_TYPE_PASSWORD;
4777 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4778 if (curr_prompt == 0) {
4779 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4780 ssh2_pkt_adduint32(num_prompts);
4782 if (need_pw) { /* only add pw if we just got one! */
4783 ssh2_pkt_addstring(password);
4784 memset(password, 0, sizeof(password));
4787 if (curr_prompt >= num_prompts) {
4791 * If there are prompts remaining, we set
4792 * `gotit' so that we won't attempt to get
4793 * another packet. Then we go back round the
4794 * loop and will end up retrieving another
4795 * prompt out of the existing packet. Funky or
4800 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4803 ("No supported authentication methods left to try!\r\n");
4805 ("No supported authentications offered. Disconnecting");
4806 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4807 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4809 ("No supported authentication methods available");
4810 ssh2_pkt_addstring("en"); /* language tag */
4812 ssh_state = SSH_STATE_CLOSED;
4816 } while (!we_are_in);
4819 * Now we're authenticated for the connection protocol. The
4820 * connection protocol will automatically have started at this
4821 * point; there's no need to send SERVICE_REQUEST.
4825 * So now create a channel with a session in it.
4827 ssh_channels = newtree234(ssh_channelcmp);
4828 mainchan = smalloc(sizeof(struct ssh_channel));
4829 mainchan->localid = alloc_channel_id();
4830 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4831 ssh2_pkt_addstring("session");
4832 ssh2_pkt_adduint32(mainchan->localid);
4833 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4834 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4835 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4837 crWaitUntilV(ispkt);
4838 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4839 bombout(("Server refused to open a session"));
4841 /* FIXME: error data comes back in FAILURE packet */
4843 if (ssh2_pkt_getuint32() != mainchan->localid) {
4844 bombout(("Server's channel confirmation cited wrong channel"));
4847 mainchan->remoteid = ssh2_pkt_getuint32();
4848 mainchan->type = CHAN_MAINSESSION;
4849 mainchan->closes = 0;
4850 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4851 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4852 bufchain_init(&mainchan->v.v2.outbuffer);
4853 add234(ssh_channels, mainchan);
4854 logevent("Opened channel for session");
4857 * Potentially enable X11 forwarding.
4859 if (cfg.x11_forward) {
4860 char proto[20], data[64];
4861 logevent("Requesting X11 forwarding");
4862 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4863 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4864 ssh2_pkt_adduint32(mainchan->remoteid);
4865 ssh2_pkt_addstring("x11-req");
4866 ssh2_pkt_addbool(1); /* want reply */
4867 ssh2_pkt_addbool(0); /* many connections */
4868 ssh2_pkt_addstring(proto);
4869 ssh2_pkt_addstring(data);
4870 ssh2_pkt_adduint32(0); /* screen number */
4874 crWaitUntilV(ispkt);
4875 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4876 unsigned i = ssh2_pkt_getuint32();
4877 struct ssh_channel *c;
4878 c = find234(ssh_channels, &i, ssh_channelfind);
4880 continue; /* nonexistent channel */
4881 c->v.v2.remwindow += ssh2_pkt_getuint32();
4883 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4885 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4886 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4887 bombout(("Unexpected response to X11 forwarding request:"
4888 " packet type %d", pktin.type));
4891 logevent("X11 forwarding refused");
4893 logevent("X11 forwarding enabled");
4894 ssh_X11_fwd_enabled = TRUE;
4899 * Enable port forwardings.
4902 static char *e; /* preserve across crReturn */
4905 int sport,dport,sserv,dserv;
4906 char sports[256], dports[256], host[256];
4910 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4911 /* Add port forwardings. */
4916 while (*e && *e != '\t')
4922 while (*e && *e != ':')
4932 dport = atoi(dports);
4936 se = getservbyname(dports, NULL);
4938 dport = ntohs(se->s_port);
4941 "Service lookup failed for destination port \"%s\"",
4946 sport = atoi(sports);
4950 se = getservbyname(sports, NULL);
4952 sport = ntohs(se->s_port);
4955 "Service lookup failed for source port \"%s\"",
4960 if (sport && dport) {
4962 pfd_addforward(host, dport, sport);
4963 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
4964 " %s:%.*s%.*s%d%.*s",
4965 sserv ? strlen(sports) : 0, sports,
4966 sserv, "(", sport, sserv, ")",
4968 dserv ? strlen(dports) : 0, dports,
4969 dserv, "(", dport, dserv, ")");
4972 struct ssh_rportfwd *pf;
4973 pf = smalloc(sizeof(*pf));
4974 strcpy(pf->dhost, host);
4977 if (add234(ssh_rportfwds, pf) != pf) {
4979 "Duplicate remote port forwarding to %s:%d",
4984 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
4985 " forward to %s:%.*s%.*s%d%.*s",
4986 sserv ? strlen(sports) : 0, sports,
4987 sserv, "(", sport, sserv, ")",
4989 dserv ? strlen(dports) : 0, dports,
4990 dserv, "(", dport, dserv, ")");
4992 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4993 ssh2_pkt_addstring("tcpip-forward");
4994 ssh2_pkt_addbool(1);/* want reply */
4995 if (cfg.rport_acceptall)
4996 ssh2_pkt_addstring("0.0.0.0");
4998 ssh2_pkt_addstring("127.0.0.1");
4999 ssh2_pkt_adduint32(sport);
5003 crWaitUntilV(ispkt);
5004 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5005 unsigned i = ssh2_pkt_getuint32();
5006 struct ssh_channel *c;
5007 c = find234(ssh_channels, &i, ssh_channelfind);
5009 continue;/* nonexistent channel */
5010 c->v.v2.remwindow += ssh2_pkt_getuint32();
5012 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5014 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5015 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5016 bombout(("Unexpected response to port "
5017 "forwarding request: packet type %d",
5021 logevent("Server refused this port forwarding");
5023 logevent("Remote port forwarding enabled");
5032 * Potentially enable agent forwarding.
5034 if (cfg.agentfwd && agent_exists()) {
5035 logevent("Requesting OpenSSH-style agent forwarding");
5036 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5037 ssh2_pkt_adduint32(mainchan->remoteid);
5038 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5039 ssh2_pkt_addbool(1); /* want reply */
5043 crWaitUntilV(ispkt);
5044 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5045 unsigned i = ssh2_pkt_getuint32();
5046 struct ssh_channel *c;
5047 c = find234(ssh_channels, &i, ssh_channelfind);
5049 continue; /* nonexistent channel */
5050 c->v.v2.remwindow += ssh2_pkt_getuint32();
5052 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5054 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5055 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5056 bombout(("Unexpected response to agent forwarding request:"
5057 " packet type %d", pktin.type));
5060 logevent("Agent forwarding refused");
5062 logevent("Agent forwarding enabled");
5063 ssh_agentfwd_enabled = TRUE;
5068 * Now allocate a pty for the session.
5071 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5072 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5073 ssh2_pkt_addstring("pty-req");
5074 ssh2_pkt_addbool(1); /* want reply */
5075 ssh2_pkt_addstring(cfg.termtype);
5076 ssh2_pkt_adduint32(cols);
5077 ssh2_pkt_adduint32(rows);
5078 ssh2_pkt_adduint32(0); /* pixel width */
5079 ssh2_pkt_adduint32(0); /* pixel height */
5080 ssh2_pkt_addstring_start();
5081 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5083 ssh_state = SSH_STATE_INTERMED;
5086 crWaitUntilV(ispkt);
5087 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5088 unsigned i = ssh2_pkt_getuint32();
5089 struct ssh_channel *c;
5090 c = find234(ssh_channels, &i, ssh_channelfind);
5092 continue; /* nonexistent channel */
5093 c->v.v2.remwindow += ssh2_pkt_getuint32();
5095 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5097 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5098 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5099 bombout(("Unexpected response to pty request:"
5100 " packet type %d", pktin.type));
5103 c_write_str("Server refused to allocate pty\r\n");
5104 ssh_editing = ssh_echoing = 1;
5106 logevent("Allocated pty");
5109 ssh_editing = ssh_echoing = 1;
5113 * Start a shell or a remote command. We may have to attempt
5114 * this twice if the config data has provided a second choice
5121 if (ssh_fallback_cmd) {
5122 subsys = cfg.ssh_subsys2;
5123 cmd = cfg.remote_cmd_ptr2;
5125 subsys = cfg.ssh_subsys;
5126 cmd = cfg.remote_cmd_ptr;
5129 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5130 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5132 ssh2_pkt_addstring("subsystem");
5133 ssh2_pkt_addbool(1); /* want reply */
5134 ssh2_pkt_addstring(cmd);
5136 ssh2_pkt_addstring("exec");
5137 ssh2_pkt_addbool(1); /* want reply */
5138 ssh2_pkt_addstring(cmd);
5140 ssh2_pkt_addstring("shell");
5141 ssh2_pkt_addbool(1); /* want reply */
5145 crWaitUntilV(ispkt);
5146 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5147 unsigned i = ssh2_pkt_getuint32();
5148 struct ssh_channel *c;
5149 c = find234(ssh_channels, &i, ssh_channelfind);
5151 continue; /* nonexistent channel */
5152 c->v.v2.remwindow += ssh2_pkt_getuint32();
5154 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5155 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5156 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5157 bombout(("Unexpected response to shell/command request:"
5158 " packet type %d", pktin.type));
5162 * We failed to start the command. If this is the
5163 * fallback command, we really are finished; if it's
5164 * not, and if the fallback command exists, try falling
5165 * back to it before complaining.
5167 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5168 logevent("Primary command failed; attempting fallback");
5169 ssh_fallback_cmd = TRUE;
5172 bombout(("Server refused to start a shell/command"));
5175 logevent("Started a shell/command");
5180 ssh_state = SSH_STATE_SESSION;
5184 ssh_special(TS_EOF);
5189 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
5192 static int try_send;
5196 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
5197 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5200 unsigned i = ssh2_pkt_getuint32();
5201 struct ssh_channel *c;
5202 c = find234(ssh_channels, &i, ssh_channelfind);
5204 continue; /* nonexistent channel */
5205 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5206 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5207 continue; /* extended but not stderr */
5208 ssh2_pkt_getstring(&data, &length);
5211 c->v.v2.locwindow -= length;
5213 case CHAN_MAINSESSION:
5215 from_backend(pktin.type ==
5216 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5220 bufsize = x11_send(c->u.x11.s, data, length);
5223 bufsize = pfd_send(c->u.pfd.s, data, length);
5226 while (length > 0) {
5227 if (c->u.a.lensofar < 4) {
5228 int l = min(4 - c->u.a.lensofar, length);
5229 memcpy(c->u.a.msglen + c->u.a.lensofar,
5233 c->u.a.lensofar += l;
5235 if (c->u.a.lensofar == 4) {
5237 4 + GET_32BIT(c->u.a.msglen);
5238 c->u.a.message = smalloc(c->u.a.totallen);
5239 memcpy(c->u.a.message, c->u.a.msglen, 4);
5241 if (c->u.a.lensofar >= 4 && length > 0) {
5243 min(c->u.a.totallen - c->u.a.lensofar,
5245 memcpy(c->u.a.message + c->u.a.lensofar,
5249 c->u.a.lensofar += l;
5251 if (c->u.a.lensofar == c->u.a.totallen) {
5252 void *reply, *sentreply;
5254 agent_query(c->u.a.message,
5255 c->u.a.totallen, &reply,
5260 /* Fake SSH_AGENT_FAILURE. */
5261 sentreply = "\0\0\0\1\5";
5264 ssh2_add_channel_data(c, sentreply,
5269 sfree(c->u.a.message);
5270 c->u.a.lensofar = 0;
5277 * If we are not buffering too much data,
5278 * enlarge the window again at the remote side.
5280 if (bufsize < OUR_V2_WINSIZE)
5281 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5283 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
5284 ssh_state = SSH_STATE_CLOSED;
5285 logevent("Received disconnect message");
5287 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
5288 unsigned i = ssh2_pkt_getuint32();
5289 struct ssh_channel *c;
5291 c = find234(ssh_channels, &i, ssh_channelfind);
5293 continue; /* nonexistent channel */
5295 if (c->type == CHAN_X11) {
5297 * Remote EOF on an X11 channel means we should
5298 * wrap up and close the channel ourselves.
5300 x11_close(c->u.x11.s);
5302 } else if (c->type == CHAN_AGENT) {
5304 } else if (c->type == CHAN_SOCKDATA) {
5305 pfd_close(c->u.pfd.s);
5308 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5309 unsigned i = ssh2_pkt_getuint32();
5310 struct ssh_channel *c;
5312 c = find234(ssh_channels, &i, ssh_channelfind);
5314 continue; /* nonexistent channel */
5315 /* Do pre-close processing on the channel. */
5317 case CHAN_MAINSESSION:
5318 break; /* nothing to see here, move along */
5320 if (c->u.x11.s != NULL)
5321 x11_close(c->u.x11.s);
5328 if (c->u.pfd.s != NULL)
5329 pfd_close(c->u.pfd.s);
5333 if (c->closes == 0) {
5334 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5335 ssh2_pkt_adduint32(c->remoteid);
5338 del234(ssh_channels, c);
5339 bufchain_clear(&c->v.v2.outbuffer);
5343 * See if that was the last channel left open.
5345 if (count234(ssh_channels) == 0) {
5348 * We used to send SSH_MSG_DISCONNECT here,
5349 * because I'd believed that _every_ conforming
5350 * SSH2 connection had to end with a disconnect
5351 * being sent by at least one side; apparently
5352 * I was wrong and it's perfectly OK to
5353 * unceremoniously slam the connection shut
5354 * when you're done, and indeed OpenSSH feels
5355 * this is more polite than sending a
5356 * DISCONNECT. So now we don't.
5358 logevent("All channels closed. Disconnecting");
5359 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5360 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5361 ssh2_pkt_addstring("All open channels closed");
5362 ssh2_pkt_addstring("en"); /* language tag */
5365 ssh_state = SSH_STATE_CLOSED;
5368 continue; /* remote sends close; ignore (FIXME) */
5369 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5370 unsigned i = ssh2_pkt_getuint32();
5371 struct ssh_channel *c;
5372 c = find234(ssh_channels, &i, ssh_channelfind);
5374 continue; /* nonexistent channel */
5375 c->v.v2.remwindow += ssh2_pkt_getuint32();
5377 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5378 unsigned i = ssh2_pkt_getuint32();
5379 struct ssh_channel *c;
5380 c = find234(ssh_channels, &i, ssh_channelfind);
5382 continue; /* nonexistent channel */
5383 if (c->type != CHAN_SOCKDATA_DORMANT)
5384 continue; /* dunno why they're confirming this */
5385 c->remoteid = ssh2_pkt_getuint32();
5386 c->type = CHAN_SOCKDATA;
5387 c->v.v2.remwindow = ssh2_pkt_getuint32();
5388 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5390 pfd_confirm(c->u.pfd.s);
5393 * We have a pending close on this channel,
5394 * which we decided on before the server acked
5395 * the channel open. So now we know the
5396 * remoteid, we can close it again.
5398 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5399 ssh2_pkt_adduint32(c->remoteid);
5402 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5403 unsigned i = ssh2_pkt_getuint32();
5404 struct ssh_channel *c;
5405 c = find234(ssh_channels, &i, ssh_channelfind);
5407 continue; /* nonexistent channel */
5408 if (c->type != CHAN_SOCKDATA_DORMANT)
5409 continue; /* dunno why they're failing this */
5411 logevent("Forwarded connection refused by server");
5413 pfd_close(c->u.pfd.s);
5415 del234(ssh_channels, c);
5417 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5420 int typelen, want_reply;
5421 struct ssh_channel *c;
5423 localid = ssh2_pkt_getuint32();
5424 ssh2_pkt_getstring(&type, &typelen);
5425 want_reply = ssh2_pkt_getbool();
5428 * First, check that the channel exists. Otherwise,
5429 * we can instantly disconnect with a rude message.
5431 c = find234(ssh_channels, &localid, ssh_channelfind);
5434 sprintf(buf, "Received channel request for nonexistent"
5435 " channel %d", localid);
5437 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5438 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5439 ssh2_pkt_addstring(buf);
5440 ssh2_pkt_addstring("en"); /* language tag */
5442 connection_fatal("%s", buf);
5443 ssh_state = SSH_STATE_CLOSED;
5448 * Having got the channel number, we now look at
5449 * the request type string to see if it's something
5452 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5454 /* We recognise "exit-status" on the primary channel. */
5456 ssh_exitcode = ssh2_pkt_getuint32();
5457 sprintf(buf, "Server sent command exit status %d",
5461 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5462 ssh2_pkt_adduint32(c->remoteid);
5467 * This is a channel request we don't know
5468 * about, so we now either ignore the request
5469 * or respond with CHANNEL_FAILURE, depending
5473 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5474 ssh2_pkt_adduint32(c->remoteid);
5478 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5480 int typelen, want_reply;
5482 ssh2_pkt_getstring(&type, &typelen);
5483 want_reply = ssh2_pkt_getbool();
5486 * We currently don't support any global requests
5487 * at all, so we either ignore the request or
5488 * respond with REQUEST_FAILURE, depending on
5492 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5495 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5499 struct ssh_channel *c;
5500 unsigned remid, winsize, pktsize;
5501 ssh2_pkt_getstring(&type, &typelen);
5502 c = smalloc(sizeof(struct ssh_channel));
5504 remid = ssh2_pkt_getuint32();
5505 winsize = ssh2_pkt_getuint32();
5506 pktsize = ssh2_pkt_getuint32();
5508 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5509 if (!ssh_X11_fwd_enabled)
5510 error = "X11 forwarding is not enabled";
5511 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5513 error = "Unable to open an X11 connection";
5517 } else if (typelen == 15 &&
5518 !memcmp(type, "forwarded-tcpip", 15)) {
5519 struct ssh_rportfwd pf, *realpf;
5522 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5523 pf.sport = ssh2_pkt_getuint32();
5524 realpf = find234(ssh_rportfwds, &pf, NULL);
5525 if (realpf == NULL) {
5526 error = "Remote port is not recognised";
5528 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5531 sprintf(buf, "Received remote port open request for %s:%d",
5532 realpf->dhost, realpf->dport);
5535 sprintf(buf, "Port open failed: %s", e);
5537 error = "Port open failed";
5539 logevent("Forwarded port opened successfully");
5540 c->type = CHAN_SOCKDATA;
5543 } else if (typelen == 22 &&
5544 !memcmp(type, "auth-agent@openssh.com", 3)) {
5545 if (!ssh_agentfwd_enabled)
5546 error = "Agent forwarding is not enabled";
5548 c->type = CHAN_AGENT; /* identify channel type */
5549 c->u.a.lensofar = 0;
5552 error = "Unsupported channel type requested";
5555 c->remoteid = remid;
5557 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5558 ssh2_pkt_adduint32(c->remoteid);
5559 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5560 ssh2_pkt_addstring(error);
5561 ssh2_pkt_addstring("en"); /* language tag */
5565 c->localid = alloc_channel_id();
5567 c->v.v2.locwindow = OUR_V2_WINSIZE;
5568 c->v.v2.remwindow = winsize;
5569 c->v.v2.remmaxpkt = pktsize;
5570 bufchain_init(&c->v.v2.outbuffer);
5571 add234(ssh_channels, c);
5572 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5573 ssh2_pkt_adduint32(c->remoteid);
5574 ssh2_pkt_adduint32(c->localid);
5575 ssh2_pkt_adduint32(c->v.v2.locwindow);
5576 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5580 bombout(("Strange packet received: type %d", pktin.type));
5585 * We have spare data. Add it to the channel buffer.
5587 ssh2_add_channel_data(mainchan, in, inlen);
5592 struct ssh_channel *c;
5594 * Try to send data on all channels if we can.
5596 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5597 int bufsize = ssh2_try_send(c);
5600 case CHAN_MAINSESSION:
5601 /* stdin need not receive an unthrottle
5602 * notification since it will be polled */
5605 x11_unthrottle(c->u.x11.s);
5608 /* agent sockets are request/response and need no
5609 * buffer management */
5612 pfd_unthrottle(c->u.pfd.s);
5624 * Handle the top-level SSH2 protocol.
5626 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5628 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5630 do_ssh2_authconn(in, inlen, ispkt);
5634 * Called to set up the connection.
5636 * Returns an error message, or NULL on success.
5638 static char *ssh_init(char *host, int port, char **realhost, int nodelay)
5643 if (crypto_startup() == 0)
5644 return "Microsoft high encryption pack not installed!";
5650 ssh1_throttle_count = 0;
5651 ssh_overall_bufsize = 0;
5652 ssh_fallback_cmd = 0;
5654 p = connect_to_host(host, port, realhost, nodelay);
5662 * Called to send data down the Telnet connection.
5664 static int ssh_send(char *buf, int len)
5666 if (s == NULL || ssh_protocol == NULL)
5669 ssh_protocol(buf, len, 0);
5671 return ssh_sendbuffer();
5675 * Called to query the current amount of buffered stdin data.
5677 static int ssh_sendbuffer(void)
5681 if (s == NULL || ssh_protocol == NULL)
5685 * If the SSH socket itself has backed up, add the total backup
5686 * size on that to any individual buffer on the stdin channel.
5689 if (ssh_throttled_all)
5690 override_value = ssh_overall_bufsize;
5692 if (ssh_version == 1) {
5693 return override_value;
5694 } else if (ssh_version == 2) {
5695 if (!mainchan || mainchan->closes > 0)
5696 return override_value;
5698 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5705 * Called to set the size of the window from SSH's POV.
5707 static void ssh_size(void)
5709 switch (ssh_state) {
5710 case SSH_STATE_BEFORE_SIZE:
5711 case SSH_STATE_PREPACKET:
5712 case SSH_STATE_CLOSED:
5713 break; /* do nothing */
5714 case SSH_STATE_INTERMED:
5715 size_needed = TRUE; /* buffer for later */
5717 case SSH_STATE_SESSION:
5719 if (ssh_version == 1) {
5720 send_packet(SSH1_CMSG_WINDOW_SIZE,
5721 PKT_INT, rows, PKT_INT, cols,
5722 PKT_INT, 0, PKT_INT, 0, PKT_END);
5724 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5725 ssh2_pkt_adduint32(mainchan->remoteid);
5726 ssh2_pkt_addstring("window-change");
5727 ssh2_pkt_addbool(0);
5728 ssh2_pkt_adduint32(cols);
5729 ssh2_pkt_adduint32(rows);
5730 ssh2_pkt_adduint32(0);
5731 ssh2_pkt_adduint32(0);
5740 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5741 * can send an EOF and collect resulting output (e.g. `plink
5744 static void ssh_special(Telnet_Special code)
5746 if (code == TS_EOF) {
5747 if (ssh_state != SSH_STATE_SESSION) {
5749 * Buffer the EOF in case we are pre-SESSION, so we can
5750 * send it as soon as we reach SESSION.
5756 if (ssh_version == 1) {
5757 send_packet(SSH1_CMSG_EOF, PKT_END);
5759 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5760 ssh2_pkt_adduint32(mainchan->remoteid);
5763 logevent("Sent EOF message");
5764 } else if (code == TS_PING) {
5765 if (ssh_state == SSH_STATE_CLOSED
5766 || ssh_state == SSH_STATE_PREPACKET) return;
5767 if (ssh_version == 1) {
5768 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5770 ssh2_pkt_init(SSH2_MSG_IGNORE);
5771 ssh2_pkt_addstring_start();
5779 void *new_sock_channel(Socket s)
5781 struct ssh_channel *c;
5782 c = smalloc(sizeof(struct ssh_channel));
5785 c->remoteid = -1; /* to be set when open confirmed */
5786 c->localid = alloc_channel_id();
5788 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5790 bufchain_init(&c->v.v2.outbuffer);
5791 add234(ssh_channels, c);
5797 * This is called when stdout/stderr (the entity to which
5798 * from_backend sends data) manages to clear some backlog.
5800 void ssh_unthrottle(int bufsize)
5802 if (ssh_version == 1) {
5803 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5804 ssh1_stdout_throttling = 0;
5808 if (mainchan && mainchan->closes == 0)
5809 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5813 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5815 struct ssh_channel *c = (struct ssh_channel *)channel;
5818 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5821 if (ssh_version == 1) {
5822 send_packet(SSH1_MSG_PORT_OPEN,
5823 PKT_INT, c->localid,
5826 //PKT_STR, <org:orgport>,
5829 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5830 ssh2_pkt_addstring("direct-tcpip");
5831 ssh2_pkt_adduint32(c->localid);
5832 c->v.v2.locwindow = OUR_V2_WINSIZE;
5833 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5834 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5835 ssh2_pkt_addstring(hostname);
5836 ssh2_pkt_adduint32(port);
5838 * We make up values for the originator data; partly it's
5839 * too much hassle to keep track, and partly I'm not
5840 * convinced the server should be told details like that
5841 * about my local network configuration.
5843 ssh2_pkt_addstring("client-side-connection");
5844 ssh2_pkt_adduint32(0);
5850 static Socket ssh_socket(void)
5855 static int ssh_sendok(void)
5860 static int ssh_ldisc(int option)
5862 if (option == LD_ECHO)
5864 if (option == LD_EDIT)
5869 static int ssh_return_exitcode(void)
5871 return ssh_exitcode;
5874 Backend ssh_backend = {
5881 ssh_return_exitcode,