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 * Handle the key exchange and user authentication phases.
2054 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
2058 static unsigned char *rsabuf, *keystr1, *keystr2;
2059 unsigned char cookie[8];
2060 struct RSAKey servkey, hostkey;
2061 struct MD5Context md5c;
2062 static unsigned long supported_ciphers_mask, supported_auths_mask;
2063 static int tried_publickey, tried_agent;
2064 static int tis_auth_refused, ccard_auth_refused;
2065 static unsigned char session_id[16];
2066 static int cipher_type;
2067 static char username[100];
2068 static void *publickey_blob;
2069 int publickey_bloblen;
2076 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2077 bombout(("Public key packet not received"));
2081 logevent("Received public keys");
2083 memcpy(cookie, pktin.body, 8);
2085 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2086 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
2089 * Log the host key fingerprint.
2093 logevent("Host key fingerprint is:");
2094 strcpy(logmsg, " ");
2095 hostkey.comment = NULL;
2096 rsa_fingerprint(logmsg + strlen(logmsg),
2097 sizeof(logmsg) - strlen(logmsg), &hostkey);
2101 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2102 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2103 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
2105 ssh1_local_protoflags =
2106 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2107 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2110 MD5Update(&md5c, keystr2, hostkey.bytes);
2111 MD5Update(&md5c, keystr1, servkey.bytes);
2112 MD5Update(&md5c, pktin.body, 8);
2113 MD5Final(session_id, &md5c);
2115 for (i = 0; i < 32; i++)
2116 session_key[i] = random_byte();
2118 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2120 rsabuf = smalloc(len);
2122 fatalbox("Out of memory");
2125 * Verify the host key.
2129 * First format the key into a string.
2131 int len = rsastr_len(&hostkey);
2132 char fingerprint[100];
2133 char *keystr = smalloc(len);
2135 fatalbox("Out of memory");
2136 rsastr_fmt(keystr, &hostkey);
2137 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2138 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2143 for (i = 0; i < 32; i++) {
2144 rsabuf[i] = session_key[i];
2146 rsabuf[i] ^= session_id[i];
2149 if (hostkey.bytes > servkey.bytes) {
2150 rsaencrypt(rsabuf, 32, &servkey);
2151 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2153 rsaencrypt(rsabuf, 32, &hostkey);
2154 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2157 logevent("Encrypted session key");
2160 int cipher_chosen = 0, warn = 0;
2161 char *cipher_string = NULL;
2162 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2163 int next_cipher = cfg.ssh_cipherlist[i];
2164 if (next_cipher == CIPHER_WARN) {
2165 /* If/when we choose a cipher, warn about it */
2167 } else if (next_cipher == CIPHER_AES) {
2168 /* XXX Probably don't need to mention this. */
2169 logevent("AES not supported in SSH1, skipping");
2171 switch (next_cipher) {
2172 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2173 cipher_string = "3DES"; break;
2174 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2175 cipher_string = "Blowfish"; break;
2176 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2177 cipher_string = "single-DES"; break;
2179 if (supported_ciphers_mask & (1 << cipher_type))
2183 if (!cipher_chosen) {
2184 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2185 bombout(("Server violates SSH 1 protocol by not "
2186 "supporting 3DES encryption"));
2188 /* shouldn't happen */
2189 bombout(("No supported ciphers found"));
2193 /* Warn about chosen cipher if necessary. */
2195 askcipher(cipher_string, 0);
2198 switch (cipher_type) {
2199 case SSH_CIPHER_3DES:
2200 logevent("Using 3DES encryption");
2202 case SSH_CIPHER_DES:
2203 logevent("Using single-DES encryption");
2205 case SSH_CIPHER_BLOWFISH:
2206 logevent("Using Blowfish encryption");
2210 send_packet(SSH1_CMSG_SESSION_KEY,
2211 PKT_CHAR, cipher_type,
2212 PKT_DATA, cookie, 8,
2213 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2214 PKT_DATA, rsabuf, len,
2215 PKT_INT, ssh1_local_protoflags, PKT_END);
2217 logevent("Trying to enable encryption...");
2221 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2222 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
2223 cipher->sesskey(session_key);
2227 if (pktin.type != SSH1_SMSG_SUCCESS) {
2228 bombout(("Encryption not successfully enabled"));
2232 logevent("Successfully started encryption");
2238 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2239 if (ssh_get_line && !ssh_getline_pw_only) {
2240 if (!ssh_get_line("login as: ",
2241 username, sizeof(username), FALSE)) {
2243 * get_line failed to get a username.
2246 logevent("No username provided. Abandoning session.");
2247 ssh_state = SSH_STATE_CLOSED;
2251 c_write_str("login as: ");
2254 crWaitUntil(!ispkt);
2256 switch (c = *in++) {
2265 c_write_str("\b \b");
2272 c_write_str("\b \b");
2281 if (((c >= ' ' && c <= '~') ||
2282 ((unsigned char) c >= 160))
2283 && pos < sizeof(username)-1) {
2284 username[pos++] = c;
2290 c_write_str("\r\n");
2291 username[strcspn(username, "\n\r")] = '\0';
2294 strncpy(username, cfg.username, 99);
2295 username[99] = '\0';
2298 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2300 char userlog[22 + sizeof(username)];
2301 sprintf(userlog, "Sent username \"%s\"", username);
2303 if (flags & FLAG_INTERACTIVE &&
2304 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2305 strcat(userlog, "\r\n");
2306 c_write_str(userlog);
2313 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2314 /* We must not attempt PK auth. Pretend we've already tried it. */
2315 tried_publickey = tried_agent = 1;
2317 tried_publickey = tried_agent = 0;
2319 tis_auth_refused = ccard_auth_refused = 0;
2320 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2322 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2323 publickey_blob = NULL;
2325 publickey_blob = NULL;
2327 while (pktin.type == SSH1_SMSG_FAILURE) {
2328 static char password[100];
2329 static char prompt[200];
2332 static int pwpkt_type;
2333 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2335 if (agent_exists() && !tried_agent) {
2337 * Attempt RSA authentication using Pageant.
2339 static unsigned char request[5], *response, *p;
2340 static int responselen;
2341 static int i, nkeys;
2342 static int authed = FALSE;
2346 logevent("Pageant is running. Requesting keys.");
2348 /* Request the keys held by the agent. */
2349 PUT_32BIT(request, 1);
2350 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2351 agent_query(request, 5, &r, &responselen);
2352 response = (unsigned char *) r;
2353 if (response && responselen >= 5 &&
2354 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2356 nkeys = GET_32BIT(p);
2360 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2363 for (i = 0; i < nkeys; i++) {
2364 static struct RSAKey key;
2365 static Bignum challenge;
2366 static char *commentp;
2367 static int commentlen;
2371 sprintf(buf, "Trying Pageant key #%d", i);
2374 if (publickey_blob &&
2375 !memcmp(p, publickey_blob, publickey_bloblen)) {
2376 logevent("This key matches configured key file");
2377 tried_publickey = 1;
2380 p += ssh1_read_bignum(p, &key.exponent);
2381 p += ssh1_read_bignum(p, &key.modulus);
2382 commentlen = GET_32BIT(p);
2386 send_packet(SSH1_CMSG_AUTH_RSA,
2387 PKT_BIGNUM, key.modulus, PKT_END);
2389 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2390 logevent("Key refused");
2393 logevent("Received RSA challenge");
2394 ssh1_read_bignum(pktin.body, &challenge);
2396 char *agentreq, *q, *ret;
2399 len = 1 + 4; /* message type, bit count */
2400 len += ssh1_bignum_length(key.exponent);
2401 len += ssh1_bignum_length(key.modulus);
2402 len += ssh1_bignum_length(challenge);
2403 len += 16; /* session id */
2404 len += 4; /* response format */
2405 agentreq = smalloc(4 + len);
2406 PUT_32BIT(agentreq, len);
2408 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2409 PUT_32BIT(q, bignum_bitcount(key.modulus));
2411 q += ssh1_write_bignum(q, key.exponent);
2412 q += ssh1_write_bignum(q, key.modulus);
2413 q += ssh1_write_bignum(q, challenge);
2414 memcpy(q, session_id, 16);
2416 PUT_32BIT(q, 1); /* response format */
2417 agent_query(agentreq, len + 4, &vret, &retlen);
2421 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2422 logevent("Sending Pageant's response");
2423 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2424 PKT_DATA, ret + 5, 16,
2428 if (pktin.type == SSH1_SMSG_SUCCESS) {
2430 ("Pageant's response accepted");
2431 if (flags & FLAG_VERBOSE) {
2433 ("Authenticated using RSA key \"");
2434 c_write(commentp, commentlen);
2435 c_write_str("\" from agent\r\n");
2440 ("Pageant's response not accepted");
2443 ("Pageant failed to answer challenge");
2447 logevent("No reply received from Pageant");
2450 freebn(key.exponent);
2451 freebn(key.modulus);
2460 if (*cfg.keyfile && !tried_publickey)
2461 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2463 if (cfg.try_tis_auth &&
2464 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2465 !tis_auth_refused) {
2466 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2467 logevent("Requested TIS authentication");
2468 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2470 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2471 logevent("TIS authentication declined");
2472 if (flags & FLAG_INTERACTIVE)
2473 c_write_str("TIS authentication refused.\r\n");
2474 tis_auth_refused = 1;
2477 int challengelen = ((pktin.body[0] << 24) |
2478 (pktin.body[1] << 16) |
2479 (pktin.body[2] << 8) |
2481 logevent("Received TIS challenge");
2482 if (challengelen > sizeof(prompt) - 1)
2483 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2484 memcpy(prompt, pktin.body + 4, challengelen);
2485 /* Prompt heuristic comes from OpenSSH */
2486 strncpy(prompt + challengelen,
2487 memchr(prompt, '\n', challengelen) ?
2488 "": "\r\nResponse: ",
2489 (sizeof prompt) - challengelen);
2490 prompt[(sizeof prompt) - 1] = '\0';
2493 if (cfg.try_tis_auth &&
2494 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2495 !ccard_auth_refused) {
2496 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2497 logevent("Requested CryptoCard authentication");
2498 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2500 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2501 logevent("CryptoCard authentication declined");
2502 c_write_str("CryptoCard authentication refused.\r\n");
2503 ccard_auth_refused = 1;
2506 int challengelen = ((pktin.body[0] << 24) |
2507 (pktin.body[1] << 16) |
2508 (pktin.body[2] << 8) |
2510 logevent("Received CryptoCard challenge");
2511 if (challengelen > sizeof(prompt) - 1)
2512 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2513 memcpy(prompt, pktin.body + 4, challengelen);
2514 strncpy(prompt + challengelen,
2515 memchr(prompt, '\n', challengelen) ?
2516 "" : "\r\nResponse: ",
2517 sizeof(prompt) - challengelen);
2518 prompt[sizeof(prompt) - 1] = '\0';
2521 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2522 sprintf(prompt, "%.90s@%.90s's password: ",
2523 username, savedhost);
2525 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2526 char *comment = NULL;
2529 if (flags & FLAG_VERBOSE)
2530 c_write_str("Trying public key authentication.\r\n");
2531 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2533 type = key_type(cfg.keyfile);
2534 if (type != SSH_KEYTYPE_SSH1) {
2535 sprintf(msgbuf, "Key is of wrong type (%s)",
2536 key_type_to_str(type));
2538 c_write_str(msgbuf);
2539 c_write_str("\r\n");
2540 tried_publickey = 1;
2543 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2544 if (flags & FLAG_VERBOSE)
2545 c_write_str("No passphrase required.\r\n");
2548 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2553 * Show password prompt, having first obtained it via a TIS
2554 * or CryptoCard exchange if we're doing TIS or CryptoCard
2558 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2560 * get_line failed to get a password (for example
2561 * because one was supplied on the command line
2562 * which has already failed to work). Terminate.
2564 send_packet(SSH1_MSG_DISCONNECT,
2565 PKT_STR, "No more passwords available to try",
2567 logevent("Unable to authenticate");
2568 connection_fatal("Unable to authenticate");
2569 ssh_state = SSH_STATE_CLOSED;
2573 /* Prompt may have come from server. We've munged it a bit, so
2574 * we know it to be zero-terminated at least once. */
2575 c_write_untrusted(prompt, strlen(prompt));
2579 crWaitUntil(!ispkt);
2581 switch (c = *in++) {
2601 if (pos < sizeof(password)-1)
2602 password[pos++] = c;
2606 c_write_str("\r\n");
2610 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2612 * Try public key authentication with the specified
2615 static struct RSAKey pubkey;
2616 static Bignum challenge, response;
2618 static unsigned char buffer[32];
2620 tried_publickey = 1;
2621 i = loadrsakey(cfg.keyfile, &pubkey, password);
2623 c_write_str("Couldn't load private key from ");
2624 c_write_str(cfg.keyfile);
2625 c_write_str(".\r\n");
2626 continue; /* go and try password */
2629 c_write_str("Wrong passphrase.\r\n");
2630 tried_publickey = 0;
2631 continue; /* try again */
2635 * Send a public key attempt.
2637 send_packet(SSH1_CMSG_AUTH_RSA,
2638 PKT_BIGNUM, pubkey.modulus, PKT_END);
2641 if (pktin.type == SSH1_SMSG_FAILURE) {
2642 c_write_str("Server refused our public key.\r\n");
2643 continue; /* go and try password */
2645 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2646 bombout(("Bizarre response to offer of public key"));
2649 ssh1_read_bignum(pktin.body, &challenge);
2650 response = rsadecrypt(challenge, &pubkey);
2651 freebn(pubkey.private_exponent); /* burn the evidence */
2653 for (i = 0; i < 32; i++) {
2654 buffer[i] = bignum_byte(response, 31 - i);
2658 MD5Update(&md5c, buffer, 32);
2659 MD5Update(&md5c, session_id, 16);
2660 MD5Final(buffer, &md5c);
2662 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2663 PKT_DATA, buffer, 16, PKT_END);
2666 if (pktin.type == SSH1_SMSG_FAILURE) {
2667 if (flags & FLAG_VERBOSE)
2669 ("Failed to authenticate with our public key.\r\n");
2670 continue; /* go and try password */
2671 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2673 ("Bizarre response to RSA authentication response"));
2677 break; /* we're through! */
2679 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2681 * Defence against traffic analysis: we send a
2682 * whole bunch of packets containing strings of
2683 * different lengths. One of these strings is the
2684 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2685 * The others are all random data in
2686 * SSH1_MSG_IGNORE packets. This way a passive
2687 * listener can't tell which is the password, and
2688 * hence can't deduce the password length.
2690 * Anybody with a password length greater than 16
2691 * bytes is going to have enough entropy in their
2692 * password that a listener won't find it _that_
2693 * much help to know how long it is. So what we'll
2696 * - if password length < 16, we send 15 packets
2697 * containing string lengths 1 through 15
2699 * - otherwise, we let N be the nearest multiple
2700 * of 8 below the password length, and send 8
2701 * packets containing string lengths N through
2702 * N+7. This won't obscure the order of
2703 * magnitude of the password length, but it will
2704 * introduce a bit of extra uncertainty.
2706 * A few servers (the old 1.2.18 through 1.2.22)
2707 * can't deal with SSH1_MSG_IGNORE. For these
2708 * servers, we need an alternative defence. We make
2709 * use of the fact that the password is interpreted
2710 * as a C string: so we can append a NUL, then some
2713 * One server (a Cisco one) can deal with neither
2714 * SSH1_MSG_IGNORE _nor_ a padded password string.
2715 * For this server we are left with no defences
2716 * against password length sniffing.
2718 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2720 * The server can deal with SSH1_MSG_IGNORE, so
2721 * we can use the primary defence.
2723 int bottom, top, pwlen, i;
2726 pwlen = strlen(password);
2728 bottom = 0; /* zero length passwords are OK! :-) */
2731 bottom = pwlen & ~7;
2735 assert(pwlen >= bottom && pwlen <= top);
2737 randomstr = smalloc(top + 1);
2739 for (i = bottom; i <= top; i++) {
2741 defer_packet(pwpkt_type, PKT_STR, password,
2744 for (j = 0; j < i; j++) {
2746 randomstr[j] = random_byte();
2747 } while (randomstr[j] == '\0');
2749 randomstr[i] = '\0';
2750 defer_packet(SSH1_MSG_IGNORE,
2751 PKT_STR, randomstr, PKT_END);
2754 logevent("Sending password with camouflage packets");
2755 ssh_pkt_defersend();
2757 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2759 * The server can't deal with SSH1_MSG_IGNORE
2760 * but can deal with padded passwords, so we
2761 * can use the secondary defence.
2767 len = strlen(password);
2768 if (len < sizeof(string)) {
2770 strcpy(string, password);
2771 len++; /* cover the zero byte */
2772 while (len < sizeof(string)) {
2773 string[len++] = (char) random_byte();
2778 logevent("Sending length-padded password");
2779 send_packet(pwpkt_type, PKT_INT, len,
2780 PKT_DATA, s, len, PKT_END);
2783 * The server has _both_
2784 * BUG_CHOKES_ON_SSH1_IGNORE and
2785 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2786 * therefore nothing we can do.
2789 len = strlen(password);
2790 logevent("Sending unpadded password");
2791 send_packet(pwpkt_type, PKT_INT, len,
2792 PKT_DATA, password, len, PKT_END);
2795 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2798 logevent("Sent password");
2799 memset(password, 0, strlen(password));
2801 if (pktin.type == SSH1_SMSG_FAILURE) {
2802 if (flags & FLAG_VERBOSE)
2803 c_write_str("Access denied\r\n");
2804 logevent("Authentication refused");
2805 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2806 logevent("Received disconnect request");
2807 ssh_state = SSH_STATE_CLOSED;
2809 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2810 bombout(("Strange packet received, type %d", pktin.type));
2815 logevent("Authentication successful");
2820 void sshfwd_close(struct ssh_channel *c)
2822 if (c && !c->closes) {
2824 * If the channel's remoteid is -1, we have sent
2825 * CHANNEL_OPEN for this channel, but it hasn't even been
2826 * acknowledged by the server. So we must set a close flag
2827 * on it now, and then when the server acks the channel
2828 * open, we can close it then.
2830 if (((int)c->remoteid) != -1) {
2831 if (ssh_version == 1) {
2832 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2835 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2836 ssh2_pkt_adduint32(c->remoteid);
2841 if (c->type == CHAN_X11) {
2843 logevent("Forwarded X11 connection terminated");
2844 } else if (c->type == CHAN_SOCKDATA ||
2845 c->type == CHAN_SOCKDATA_DORMANT) {
2847 logevent("Forwarded port closed");
2852 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2854 if (ssh_version == 1) {
2855 send_packet(SSH1_MSG_CHANNEL_DATA,
2856 PKT_INT, c->remoteid,
2857 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2859 * In SSH1 we can return 0 here - implying that forwarded
2860 * connections are never individually throttled - because
2861 * the only circumstance that can cause throttling will be
2862 * the whole SSH connection backing up, in which case
2863 * _everything_ will be throttled as a whole.
2867 ssh2_add_channel_data(c, buf, len);
2868 return ssh2_try_send(c);
2872 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2874 if (ssh_version == 1) {
2875 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2876 c->v.v1.throttling = 0;
2880 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2884 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2890 while (!do_ssh1_login(in, inlen, ispkt)) {
2893 if (ssh_state == SSH_STATE_CLOSED)
2896 if (cfg.agentfwd && agent_exists()) {
2897 logevent("Requesting agent forwarding");
2898 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2902 if (pktin.type != SSH1_SMSG_SUCCESS
2903 && pktin.type != SSH1_SMSG_FAILURE) {
2904 bombout(("Protocol confusion"));
2906 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2907 logevent("Agent forwarding refused");
2909 logevent("Agent forwarding enabled");
2910 ssh_agentfwd_enabled = TRUE;
2914 if (cfg.x11_forward) {
2915 char proto[20], data[64];
2916 logevent("Requesting X11 forwarding");
2917 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2918 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2919 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2920 PKT_STR, proto, PKT_STR, data,
2921 PKT_INT, 0, PKT_END);
2923 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2924 PKT_STR, proto, PKT_STR, data, PKT_END);
2929 if (pktin.type != SSH1_SMSG_SUCCESS
2930 && pktin.type != SSH1_SMSG_FAILURE) {
2931 bombout(("Protocol confusion"));
2933 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2934 logevent("X11 forwarding refused");
2936 logevent("X11 forwarding enabled");
2937 ssh_X11_fwd_enabled = TRUE;
2945 int sport,dport,sserv,dserv;
2946 char sports[256], dports[256], host[256];
2950 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2951 /* Add port forwardings. */
2956 while (*e && *e != '\t')
2962 while (*e && *e != ':')
2972 dport = atoi(dports);
2976 se = getservbyname(dports, NULL);
2978 dport = ntohs(se->s_port);
2981 "Service lookup failed for destination port \"%s\"",
2986 sport = atoi(sports);
2990 se = getservbyname(sports, NULL);
2992 sport = ntohs(se->s_port);
2995 "Service lookup failed for source port \"%s\"",
3000 if (sport && dport) {
3002 pfd_addforward(host, dport, sport);
3003 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3004 " %s:%.*s%.*s%d%.*s",
3005 sserv ? strlen(sports) : 0, sports,
3006 sserv, "(", sport, sserv, ")",
3008 dserv ? strlen(dports) : 0, dports,
3009 dserv, "(", dport, dserv, ")");
3012 struct ssh_rportfwd *pf;
3013 pf = smalloc(sizeof(*pf));
3014 strcpy(pf->dhost, host);
3016 if (add234(ssh_rportfwds, pf) != pf) {
3018 "Duplicate remote port forwarding to %s:%d",
3023 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3024 " forward to %s:%.*s%.*s%d%.*s",
3025 sserv ? strlen(sports) : 0, sports,
3026 sserv, "(", sport, sserv, ")",
3028 dserv ? strlen(dports) : 0, dports,
3029 dserv, "(", dport, dserv, ")");
3031 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3039 if (pktin.type != SSH1_SMSG_SUCCESS
3040 && pktin.type != SSH1_SMSG_FAILURE) {
3041 bombout(("Protocol confusion"));
3043 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3044 c_write_str("Server refused port forwarding\r\n");
3045 ssh_editing = ssh_echoing = 1;
3047 logevent("Remote port forwarding enabled");
3055 send_packet(SSH1_CMSG_REQUEST_PTY,
3056 PKT_STR, cfg.termtype,
3057 PKT_INT, rows, PKT_INT, cols,
3058 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3059 ssh_state = SSH_STATE_INTERMED;
3063 if (pktin.type != SSH1_SMSG_SUCCESS
3064 && pktin.type != SSH1_SMSG_FAILURE) {
3065 bombout(("Protocol confusion"));
3067 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3068 c_write_str("Server refused to allocate pty\r\n");
3069 ssh_editing = ssh_echoing = 1;
3071 logevent("Allocated pty");
3073 ssh_editing = ssh_echoing = 1;
3076 if (cfg.compression) {
3077 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3081 if (pktin.type != SSH1_SMSG_SUCCESS
3082 && pktin.type != SSH1_SMSG_FAILURE) {
3083 bombout(("Protocol confusion"));
3085 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3086 c_write_str("Server refused to compress\r\n");
3088 logevent("Started compression");
3089 ssh1_compressing = TRUE;
3090 zlib_compress_init();
3091 zlib_decompress_init();
3095 * Start the shell or command.
3097 * Special case: if the first-choice command is an SSH2
3098 * subsystem (hence not usable here) and the second choice
3099 * exists, we fall straight back to that.
3102 char *cmd = cfg.remote_cmd_ptr;
3104 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3105 cmd = cfg.remote_cmd_ptr2;
3106 ssh_fallback_cmd = TRUE;
3109 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3111 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3112 logevent("Started session");
3115 ssh_state = SSH_STATE_SESSION;
3119 ssh_special(TS_EOF);
3121 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
3123 ssh_channels = newtree234(ssh_channelcmp);
3127 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
3128 pktin.type == SSH1_SMSG_STDERR_DATA) {
3129 long len = GET_32BIT(pktin.body);
3131 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3132 pktin.body + 4, len);
3133 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3134 ssh1_stdout_throttling = 1;
3137 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
3138 ssh_state = SSH_STATE_CLOSED;
3139 logevent("Received disconnect request");
3141 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3142 /* Remote side is trying to open a channel to talk to our
3143 * X-Server. Give them back a local channel number. */
3144 struct ssh_channel *c;
3146 logevent("Received X11 connect request");
3147 /* Refuse if X11 forwarding is disabled. */
3148 if (!ssh_X11_fwd_enabled) {
3149 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3150 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3151 logevent("Rejected X11 connect request");
3153 c = smalloc(sizeof(struct ssh_channel));
3155 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3156 logevent("opening X11 forward connection failed");
3158 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3159 PKT_INT, GET_32BIT(pktin.body),
3163 ("opening X11 forward connection succeeded");
3164 c->remoteid = GET_32BIT(pktin.body);
3165 c->localid = alloc_channel_id();
3167 c->v.v1.throttling = 0;
3168 c->type = CHAN_X11; /* identify channel type */
3169 add234(ssh_channels, c);
3170 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3171 PKT_INT, c->remoteid, PKT_INT,
3172 c->localid, PKT_END);
3173 logevent("Opened X11 forward channel");
3176 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3177 /* Remote side is trying to open a channel to talk to our
3178 * agent. Give them back a local channel number. */
3179 struct ssh_channel *c;
3181 /* Refuse if agent forwarding is disabled. */
3182 if (!ssh_agentfwd_enabled) {
3183 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3184 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3186 c = smalloc(sizeof(struct ssh_channel));
3187 c->remoteid = GET_32BIT(pktin.body);
3188 c->localid = alloc_channel_id();
3190 c->v.v1.throttling = 0;
3191 c->type = CHAN_AGENT; /* identify channel type */
3192 c->u.a.lensofar = 0;
3193 add234(ssh_channels, c);
3194 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3195 PKT_INT, c->remoteid, PKT_INT, c->localid,
3198 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3199 /* Remote side is trying to open a channel to talk to a
3200 * forwarded port. Give them back a local channel number. */
3201 struct ssh_channel *c;
3202 struct ssh_rportfwd pf;
3204 char host[256], buf[1024];
3206 c = smalloc(sizeof(struct ssh_channel));
3208 hostsize = GET_32BIT(pktin.body+4);
3209 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3210 if (h+1 < host+sizeof(host))
3215 port = GET_32BIT(p);
3217 strcpy(pf.dhost, host);
3220 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3221 sprintf(buf, "Rejected remote port open request for %s:%d",
3224 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3225 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3227 sprintf(buf, "Received remote port open request for %s:%d",
3230 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3233 sprintf(buf, "Port open failed: %s", e);
3236 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3237 PKT_INT, GET_32BIT(pktin.body),
3240 c->remoteid = GET_32BIT(pktin.body);
3241 c->localid = alloc_channel_id();
3243 c->v.v1.throttling = 0;
3244 c->type = CHAN_SOCKDATA; /* identify channel type */
3245 add234(ssh_channels, c);
3246 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3247 PKT_INT, c->remoteid, PKT_INT,
3248 c->localid, PKT_END);
3249 logevent("Forwarded port opened successfully");
3253 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3254 unsigned int remoteid = GET_32BIT(pktin.body);
3255 unsigned int localid = GET_32BIT(pktin.body+4);
3256 struct ssh_channel *c;
3258 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3259 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3260 c->remoteid = localid;
3261 c->type = CHAN_SOCKDATA;
3262 c->v.v1.throttling = 0;
3263 pfd_confirm(c->u.pfd.s);
3266 if (c && c->closes) {
3268 * We have a pending close on this channel,
3269 * which we decided on before the server acked
3270 * the channel open. So now we know the
3271 * remoteid, we can close it again.
3273 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3277 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3278 unsigned int remoteid = GET_32BIT(pktin.body);
3279 unsigned int localid = GET_32BIT(pktin.body+4);
3280 struct ssh_channel *c;
3282 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3283 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3284 logevent("Forwarded connection refused by server");
3285 pfd_close(c->u.pfd.s);
3286 del234(ssh_channels, c);
3290 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3291 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3292 /* Remote side closes a channel. */
3293 unsigned i = GET_32BIT(pktin.body);
3294 struct ssh_channel *c;
3295 c = find234(ssh_channels, &i, ssh_channelfind);
3299 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3300 if (!(c->closes & closetype))
3301 send_packet(pktin.type, PKT_INT, c->remoteid,
3303 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3304 logevent("Forwarded X11 connection terminated");
3305 assert(c->u.x11.s != NULL);
3306 x11_close(c->u.x11.s);
3309 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3310 logevent("Forwarded port closed");
3311 assert(c->u.pfd.s != NULL);
3312 pfd_close(c->u.pfd.s);
3315 c->closes |= closetype;
3316 if (c->closes == 3) {
3317 del234(ssh_channels, c);
3321 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3322 /* Data sent down one of our channels. */
3323 int i = GET_32BIT(pktin.body);
3324 int len = GET_32BIT(pktin.body + 4);
3325 unsigned char *p = pktin.body + 8;
3326 struct ssh_channel *c;
3327 c = find234(ssh_channels, &i, ssh_channelfind);
3332 bufsize = x11_send(c->u.x11.s, p, len);
3335 bufsize = pfd_send(c->u.pfd.s, p, len);
3338 /* Data for an agent message. Buffer it. */
3340 if (c->u.a.lensofar < 4) {
3341 int l = min(4 - c->u.a.lensofar, len);
3342 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3346 c->u.a.lensofar += l;
3348 if (c->u.a.lensofar == 4) {
3350 4 + GET_32BIT(c->u.a.msglen);
3351 c->u.a.message = smalloc(c->u.a.totallen);
3352 memcpy(c->u.a.message, c->u.a.msglen, 4);
3354 if (c->u.a.lensofar >= 4 && len > 0) {
3356 min(c->u.a.totallen - c->u.a.lensofar,
3358 memcpy(c->u.a.message + c->u.a.lensofar, p,
3362 c->u.a.lensofar += l;
3364 if (c->u.a.lensofar == c->u.a.totallen) {
3365 void *reply, *sentreply;
3367 agent_query(c->u.a.message,
3368 c->u.a.totallen, &reply,
3373 /* Fake SSH_AGENT_FAILURE. */
3374 sentreply = "\0\0\0\1\5";
3377 send_packet(SSH1_MSG_CHANNEL_DATA,
3378 PKT_INT, c->remoteid,
3380 PKT_DATA, sentreply, replylen,
3384 sfree(c->u.a.message);
3385 c->u.a.lensofar = 0;
3388 bufsize = 0; /* agent channels never back up */
3391 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3392 c->v.v1.throttling = 1;
3396 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3397 /* may be from EXEC_SHELL on some servers */
3398 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3399 /* may be from EXEC_SHELL on some servers
3400 * if no pty is available or in other odd cases. Ignore */
3401 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3403 ssh_exitcode = GET_32BIT(pktin.body);
3404 sprintf(buf, "Server sent command exit status %d",
3407 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3409 * In case `helpful' firewalls or proxies tack
3410 * extra human-readable text on the end of the
3411 * session which we might mistake for another
3412 * encrypted packet, we close the session once
3413 * we've sent EXIT_CONFIRMATION.
3415 ssh_state = SSH_STATE_CLOSED;
3418 bombout(("Strange packet received: type %d", pktin.type));
3423 int len = min(inlen, 512);
3424 send_packet(SSH1_CMSG_STDIN_DATA,
3425 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3436 * Utility routine for decoding comma-separated strings in KEXINIT.
3438 static int in_commasep_string(char *needle, char *haystack, int haylen)
3440 int needlen = strlen(needle);
3443 * Is it at the start of the string?
3445 if (haylen >= needlen && /* haystack is long enough */
3446 !memcmp(needle, haystack, needlen) && /* initial match */
3447 (haylen == needlen || haystack[needlen] == ',')
3448 /* either , or EOS follows */
3452 * If not, search for the next comma and resume after that.
3453 * If no comma found, terminate.
3455 while (haylen > 0 && *haystack != ',')
3456 haylen--, haystack++;
3459 haylen--, haystack++; /* skip over comma itself */
3464 * SSH2 key creation method.
3466 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3470 /* First 20 bytes. */
3473 SHA_Bytes(&s, H, 20);
3474 SHA_Bytes(&s, &chr, 1);
3475 SHA_Bytes(&s, sessid, 20);
3476 SHA_Final(&s, keyspace);
3477 /* Next 20 bytes. */
3480 SHA_Bytes(&s, H, 20);
3481 SHA_Bytes(&s, keyspace, 20);
3482 SHA_Final(&s, keyspace + 20);
3486 * Handle the SSH2 transport layer.
3488 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3490 static int i, j, len, nbits, pbits, warn;
3492 static Bignum p, g, e, f, K;
3493 static int kex_init_value, kex_reply_value;
3494 static const struct ssh_mac **maclist;
3496 static const struct ssh2_cipher *cscipher_tobe = NULL;
3497 static const struct ssh2_cipher *sccipher_tobe = NULL;
3498 static const struct ssh_mac *csmac_tobe = NULL;
3499 static const struct ssh_mac *scmac_tobe = NULL;
3500 static const struct ssh_compress *cscomp_tobe = NULL;
3501 static const struct ssh_compress *sccomp_tobe = NULL;
3502 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3503 static int hostkeylen, siglen;
3504 static void *hkey; /* actual host key */
3505 static unsigned char exchange_hash[20];
3506 static unsigned char keyspace[40];
3507 static int n_preferred_ciphers;
3508 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3509 static const struct ssh_compress *preferred_comp;
3510 static int cipherstr_started;
3511 static int first_kex;
3518 * Set up the preferred ciphers. (NULL => warn below here)
3520 n_preferred_ciphers = 0;
3521 for (i = 0; i < CIPHER_MAX; i++) {
3522 switch (cfg.ssh_cipherlist[i]) {
3523 case CIPHER_BLOWFISH:
3524 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3525 n_preferred_ciphers++;
3528 if (cfg.ssh2_des_cbc) {
3529 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3530 n_preferred_ciphers++;
3534 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3535 n_preferred_ciphers++;
3538 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3539 n_preferred_ciphers++;
3542 /* Flag for later. Don't bother if it's the last in
3544 if (i < CIPHER_MAX - 1) {
3545 preferred_ciphers[n_preferred_ciphers] = NULL;
3546 n_preferred_ciphers++;
3553 * Set up preferred compression.
3555 if (cfg.compression)
3556 preferred_comp = &ssh_zlib;
3558 preferred_comp = &ssh_comp_none;
3561 * Be prepared to work around the buggy MAC problem.
3563 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3564 maclist = buggymacs, nmacs = lenof(buggymacs);
3566 maclist = macs, nmacs = lenof(macs);
3570 * Construct and send our key exchange packet.
3572 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3573 for (i = 0; i < 16; i++)
3574 ssh2_pkt_addbyte((unsigned char) random_byte());
3575 /* List key exchange algorithms. */
3576 ssh2_pkt_addstring_start();
3577 for (i = 0; i < lenof(kex_algs); i++) {
3578 ssh2_pkt_addstring_str(kex_algs[i]->name);
3579 if (i < lenof(kex_algs) - 1)
3580 ssh2_pkt_addstring_str(",");
3582 /* List server host key algorithms. */
3583 ssh2_pkt_addstring_start();
3584 for (i = 0; i < lenof(hostkey_algs); i++) {
3585 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3586 if (i < lenof(hostkey_algs) - 1)
3587 ssh2_pkt_addstring_str(",");
3589 /* List client->server encryption algorithms. */
3590 ssh2_pkt_addstring_start();
3591 cipherstr_started = 0;
3592 for (i = 0; i < n_preferred_ciphers; i++) {
3593 const struct ssh2_ciphers *c = preferred_ciphers[i];
3594 if (!c) continue; /* warning flag */
3595 for (j = 0; j < c->nciphers; j++) {
3596 if (cipherstr_started)
3597 ssh2_pkt_addstring_str(",");
3598 ssh2_pkt_addstring_str(c->list[j]->name);
3599 cipherstr_started = 1;
3602 /* List server->client encryption algorithms. */
3603 ssh2_pkt_addstring_start();
3604 cipherstr_started = 0;
3605 for (i = 0; i < n_preferred_ciphers; i++) {
3606 const struct ssh2_ciphers *c = preferred_ciphers[i];
3607 if (!c) continue; /* warning flag */
3608 for (j = 0; j < c->nciphers; j++) {
3609 if (cipherstr_started)
3610 ssh2_pkt_addstring_str(",");
3611 ssh2_pkt_addstring_str(c->list[j]->name);
3612 cipherstr_started = 1;
3615 /* List client->server MAC algorithms. */
3616 ssh2_pkt_addstring_start();
3617 for (i = 0; i < nmacs; i++) {
3618 ssh2_pkt_addstring_str(maclist[i]->name);
3620 ssh2_pkt_addstring_str(",");
3622 /* List server->client MAC algorithms. */
3623 ssh2_pkt_addstring_start();
3624 for (i = 0; i < nmacs; i++) {
3625 ssh2_pkt_addstring_str(maclist[i]->name);
3627 ssh2_pkt_addstring_str(",");
3629 /* List client->server compression algorithms. */
3630 ssh2_pkt_addstring_start();
3631 for (i = 0; i < lenof(compressions) + 1; i++) {
3632 const struct ssh_compress *c =
3633 i == 0 ? preferred_comp : compressions[i - 1];
3634 ssh2_pkt_addstring_str(c->name);
3635 if (i < lenof(compressions))
3636 ssh2_pkt_addstring_str(",");
3638 /* List server->client compression algorithms. */
3639 ssh2_pkt_addstring_start();
3640 for (i = 0; i < lenof(compressions) + 1; i++) {
3641 const struct ssh_compress *c =
3642 i == 0 ? preferred_comp : compressions[i - 1];
3643 ssh2_pkt_addstring_str(c->name);
3644 if (i < lenof(compressions))
3645 ssh2_pkt_addstring_str(",");
3647 /* List client->server languages. Empty list. */
3648 ssh2_pkt_addstring_start();
3649 /* List server->client languages. Empty list. */
3650 ssh2_pkt_addstring_start();
3651 /* First KEX packet does _not_ follow, because we're not that brave. */
3652 ssh2_pkt_addbool(FALSE);
3654 ssh2_pkt_adduint32(0);
3656 exhash = exhashbase;
3657 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3663 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3666 * Now examine the other side's KEXINIT to see what we're up
3669 if (pktin.type != SSH2_MSG_KEXINIT) {
3670 bombout(("expected key exchange packet from server"));
3675 cscipher_tobe = NULL;
3676 sccipher_tobe = NULL;
3681 pktin.savedpos += 16; /* skip garbage cookie */
3682 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3683 for (i = 0; i < lenof(kex_algs); i++) {
3684 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3689 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3690 for (i = 0; i < lenof(hostkey_algs); i++) {
3691 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3692 hostkey = hostkey_algs[i];
3696 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3698 for (i = 0; i < n_preferred_ciphers; i++) {
3699 const struct ssh2_ciphers *c = preferred_ciphers[i];
3703 for (j = 0; j < c->nciphers; j++) {
3704 if (in_commasep_string(c->list[j]->name, str, len)) {
3705 cscipher_tobe = c->list[j];
3710 if (cscipher_tobe) {
3712 askcipher(cscipher_tobe->name, 1);
3716 if (!cscipher_tobe) {
3717 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3721 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3723 for (i = 0; i < n_preferred_ciphers; i++) {
3724 const struct ssh2_ciphers *c = preferred_ciphers[i];
3728 for (j = 0; j < c->nciphers; j++) {
3729 if (in_commasep_string(c->list[j]->name, str, len)) {
3730 sccipher_tobe = c->list[j];
3735 if (sccipher_tobe) {
3737 askcipher(sccipher_tobe->name, 2);
3741 if (!sccipher_tobe) {
3742 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3746 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3747 for (i = 0; i < nmacs; i++) {
3748 if (in_commasep_string(maclist[i]->name, str, len)) {
3749 csmac_tobe = maclist[i];
3753 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3754 for (i = 0; i < nmacs; i++) {
3755 if (in_commasep_string(maclist[i]->name, str, len)) {
3756 scmac_tobe = maclist[i];
3760 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3761 for (i = 0; i < lenof(compressions) + 1; i++) {
3762 const struct ssh_compress *c =
3763 i == 0 ? preferred_comp : compressions[i - 1];
3764 if (in_commasep_string(c->name, str, len)) {
3769 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3770 for (i = 0; i < lenof(compressions) + 1; i++) {
3771 const struct ssh_compress *c =
3772 i == 0 ? preferred_comp : compressions[i - 1];
3773 if (in_commasep_string(c->name, str, len)) {
3780 * Work out the number of bits of key we will need from the key
3781 * exchange. We start with the maximum key length of either
3787 csbits = cscipher_tobe->keylen;
3788 scbits = sccipher_tobe->keylen;
3789 nbits = (csbits > scbits ? csbits : scbits);
3791 /* The keys only have 160-bit entropy, since they're based on
3792 * a SHA-1 hash. So cap the key size at 160 bits. */
3797 * If we're doing Diffie-Hellman group exchange, start by
3798 * requesting a group.
3800 if (kex == &ssh_diffiehellman_gex) {
3801 logevent("Doing Diffie-Hellman group exchange");
3802 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
3804 * Work out how big a DH group we will need to allow that
3807 pbits = 512 << ((nbits - 1) / 64);
3808 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3809 ssh2_pkt_adduint32(pbits);
3813 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3814 bombout(("expected key exchange group packet from server"));
3817 p = ssh2_pkt_getmp();
3818 g = ssh2_pkt_getmp();
3819 dh_setup_group(p, g);
3820 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3821 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3823 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3825 kex_init_value = SSH2_MSG_KEXDH_INIT;
3826 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3829 logevent("Doing Diffie-Hellman key exchange");
3831 * Now generate and send e for Diffie-Hellman.
3833 e = dh_create_e(nbits * 2);
3834 ssh2_pkt_init(kex_init_value);
3839 if (pktin.type != kex_reply_value) {
3840 bombout(("expected key exchange reply packet from server"));
3843 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3844 f = ssh2_pkt_getmp();
3845 ssh2_pkt_getstring(&sigdata, &siglen);
3849 sha_string(&exhash, hostkeydata, hostkeylen);
3850 if (kex == &ssh_diffiehellman_gex) {
3851 sha_uint32(&exhash, pbits);
3852 sha_mpint(&exhash, p);
3853 sha_mpint(&exhash, g);
3855 sha_mpint(&exhash, e);
3856 sha_mpint(&exhash, f);
3857 sha_mpint(&exhash, K);
3858 SHA_Final(&exhash, exchange_hash);
3863 debug(("Exchange hash is:\n"));
3864 dmemdump(exchange_hash, 20);
3867 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3869 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3870 bombout(("Server's host key did not match the signature supplied"));
3875 * Authenticate remote host: verify host key. (We've already
3876 * checked the signature of the exchange hash.)
3878 keystr = hostkey->fmtkey(hkey);
3879 fingerprint = hostkey->fingerprint(hkey);
3880 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3881 keystr, fingerprint);
3882 if (first_kex) { /* don't bother logging this in rekeys */
3883 logevent("Host key fingerprint is:");
3884 logevent(fingerprint);
3888 hostkey->freekey(hkey);
3891 * Send SSH2_MSG_NEWKEYS.
3893 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3897 * Expect SSH2_MSG_NEWKEYS from server.
3900 if (pktin.type != SSH2_MSG_NEWKEYS) {
3901 bombout(("expected new-keys packet from server"));
3906 * Create and initialise session keys.
3908 cscipher = cscipher_tobe;
3909 sccipher = sccipher_tobe;
3912 cscomp = cscomp_tobe;
3913 sccomp = sccomp_tobe;
3914 cscomp->compress_init();
3915 sccomp->decompress_init();
3917 * Set IVs after keys. Here we use the exchange hash from the
3918 * _first_ key exchange.
3921 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3922 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3923 cscipher->setcskey(keyspace);
3924 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3925 sccipher->setsckey(keyspace);
3926 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3927 cscipher->setcsiv(keyspace);
3928 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3929 sccipher->setsciv(keyspace);
3930 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3931 csmac->setcskey(keyspace);
3932 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3933 scmac->setsckey(keyspace);
3936 * If this is the first key exchange phase, we must pass the
3937 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3938 * wants to see it but because it will need time to initialise
3939 * itself before it sees an actual packet. In subsequent key
3940 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3941 * it would only confuse the layer above.
3949 * Now we're encrypting. Begin returning 1 to the protocol main
3950 * function so that other things can run on top of the
3951 * transport. If we ever see a KEXINIT, we must go back to the
3954 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3957 logevent("Server initiated key re-exchange");
3958 goto begin_key_exchange;
3964 * Add data to an SSH2 channel output buffer.
3966 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3969 bufchain_add(&c->v.v2.outbuffer, buf, len);
3973 * Attempt to send data on an SSH2 channel.
3975 static int ssh2_try_send(struct ssh_channel *c)
3977 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3980 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3981 if ((unsigned)len > c->v.v2.remwindow)
3982 len = c->v.v2.remwindow;
3983 if ((unsigned)len > c->v.v2.remmaxpkt)
3984 len = c->v.v2.remmaxpkt;
3985 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3986 ssh2_pkt_adduint32(c->remoteid);
3987 ssh2_pkt_addstring_start();
3988 ssh2_pkt_addstring_data(data, len);
3990 bufchain_consume(&c->v.v2.outbuffer, len);
3991 c->v.v2.remwindow -= len;
3995 * After having sent as much data as we can, return the amount
3998 return bufchain_size(&c->v.v2.outbuffer);
4002 * Potentially enlarge the window on an SSH2 channel.
4004 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4007 * Never send WINDOW_ADJUST for a channel that the remote side
4008 * already thinks it's closed; there's no point, since it won't
4009 * be sending any more data anyway.
4014 if (newwin > c->v.v2.locwindow) {
4015 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4016 ssh2_pkt_adduint32(c->remoteid);
4017 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4019 c->v.v2.locwindow = newwin;
4024 * Handle the SSH2 userauth and connection layers.
4026 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4029 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4031 AUTH_KEYBOARD_INTERACTIVE
4035 AUTH_TYPE_PUBLICKEY,
4036 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4037 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4039 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4040 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4042 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4043 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
4044 static int kbd_inter_running;
4045 static int we_are_in;
4046 static int num_prompts, curr_prompt, echo;
4047 static char username[100];
4048 static int got_username;
4049 static char pwprompt[200];
4050 static char password[100];
4051 static void *publickey_blob;
4052 static int publickey_bloblen;
4057 * Request userauth protocol, and await a response to it.
4059 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4060 ssh2_pkt_addstring("ssh-userauth");
4062 crWaitUntilV(ispkt);
4063 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4064 bombout(("Server refused user authentication protocol"));
4069 * We repeat this whole loop, including the username prompt,
4070 * until we manage a successful authentication. If the user
4071 * types the wrong _password_, they are sent back to the
4072 * beginning to try another username. (If they specify a
4073 * username in the config, they are never asked, even if they
4074 * do give a wrong password.)
4076 * I think this best serves the needs of
4078 * - the people who have no configuration, no keys, and just
4079 * want to try repeated (username,password) pairs until they
4080 * type both correctly
4082 * - people who have keys and configuration but occasionally
4083 * need to fall back to passwords
4085 * - people with a key held in Pageant, who might not have
4086 * logged in to a particular machine before; so they want to
4087 * type a username, and then _either_ their key will be
4088 * accepted, _or_ they will type a password. If they mistype
4089 * the username they will want to be able to get back and
4093 got_username = FALSE;
4102 if (got_username && !cfg.change_username) {
4104 * We got a username last time round this loop, and
4105 * with change_username turned off we don't try to get
4108 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4109 if (ssh_get_line && !ssh_getline_pw_only) {
4110 if (!ssh_get_line("login as: ",
4111 username, sizeof(username), FALSE)) {
4113 * get_line failed to get a username.
4116 logevent("No username provided. Abandoning session.");
4117 ssh_state = SSH_STATE_CLOSED;
4121 c_write_str("login as: ");
4124 crWaitUntilV(!ispkt);
4126 switch (c = *in++) {
4135 c_write_str("\b \b");
4142 c_write_str("\b \b");
4151 if (((c >= ' ' && c <= '~') ||
4152 ((unsigned char) c >= 160))
4153 && pos < sizeof(username)-1) {
4154 username[pos++] = c;
4161 c_write_str("\r\n");
4162 username[strcspn(username, "\n\r")] = '\0';
4165 strncpy(username, cfg.username, 99);
4166 username[99] = '\0';
4167 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4168 sprintf(stuff, "Using username \"%s\".\r\n", username);
4172 got_username = TRUE;
4175 * Send an authentication request using method "none": (a)
4176 * just in case it succeeds, and (b) so that we know what
4177 * authentication methods we can usefully try next.
4179 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4181 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4182 ssh2_pkt_addstring(username);
4183 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4184 ssh2_pkt_addstring("none"); /* method */
4186 type = AUTH_TYPE_NONE;
4190 tried_pubkey_config = FALSE;
4191 tried_agent = FALSE;
4192 tried_keyb_inter = FALSE;
4193 kbd_inter_running = FALSE;
4194 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4197 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4198 keytype = key_type(cfg.keyfile);
4199 if (keytype == SSH_KEYTYPE_SSH2)
4200 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4201 &publickey_bloblen);
4204 logeventf("Unable to use this key file (%s)",
4205 key_type_to_str(keytype));
4206 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4207 cfg.keyfile, key_type_to_str(keytype));
4208 c_write_str(msgbuf);
4209 publickey_blob = NULL;
4212 publickey_blob = NULL;
4216 * Wait for the result of the last authentication request.
4219 crWaitUntilV(ispkt);
4220 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4224 * Don't show the banner if we're operating in
4225 * non-verbose non-interactive mode. (It's probably
4226 * a script, which means nobody will read the
4227 * banner _anyway_, and moreover the printing of
4228 * the banner will screw up processing on the
4229 * output of (say) plink.)
4231 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4232 ssh2_pkt_getstring(&banner, &size);
4234 c_write_untrusted(banner, size);
4236 crWaitUntilV(ispkt);
4238 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4239 logevent("Access granted");
4244 if (kbd_inter_running &&
4245 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4247 * This is either a further set-of-prompts packet
4248 * in keyboard-interactive authentication, or it's
4249 * the same one and we came back here with `gotit'
4250 * set. In the former case, we must reset the
4251 * curr_prompt variable.
4255 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4256 bombout(("Strange packet received during authentication: type %d",
4264 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4265 * we can look at the string in it and know what we can
4266 * helpfully try next.
4268 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4271 ssh2_pkt_getstring(&methods, &methlen);
4272 kbd_inter_running = FALSE;
4273 if (!ssh2_pkt_getbool()) {
4275 * We have received an unequivocal Access
4276 * Denied. This can translate to a variety of
4279 * - if we'd just tried "none" authentication,
4280 * it's not worth printing anything at all
4282 * - if we'd just tried a public key _offer_,
4283 * the message should be "Server refused our
4284 * key" (or no message at all if the key
4285 * came from Pageant)
4287 * - if we'd just tried anything else, the
4288 * message really should be "Access denied".
4290 * Additionally, if we'd just tried password
4291 * authentication, we should break out of this
4292 * whole loop so as to go back to the username
4295 if (type == AUTH_TYPE_NONE) {
4297 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4298 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4299 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4300 c_write_str("Server refused our key\r\n");
4301 logevent("Server refused public key");
4302 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4303 /* server declined keyboard-interactive; ignore */
4305 c_write_str("Access denied\r\n");
4306 logevent("Access denied");
4307 if (type == AUTH_TYPE_PASSWORD) {
4313 c_write_str("Further authentication required\r\n");
4314 logevent("Further authentication required");
4318 in_commasep_string("publickey", methods, methlen);
4320 in_commasep_string("password", methods, methlen);
4321 can_keyb_inter = cfg.try_ki_auth &&
4322 in_commasep_string("keyboard-interactive", methods, methlen);
4326 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4328 if (!method && can_pubkey && agent_exists() && !tried_agent) {
4330 * Attempt public-key authentication using Pageant.
4332 static unsigned char request[5], *response, *p;
4333 static int responselen;
4334 static int i, nkeys;
4335 static int authed = FALSE;
4338 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4339 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4343 logevent("Pageant is running. Requesting keys.");
4345 /* Request the keys held by the agent. */
4346 PUT_32BIT(request, 1);
4347 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4348 agent_query(request, 5, &r, &responselen);
4349 response = (unsigned char *) r;
4350 if (response && responselen >= 5 &&
4351 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4353 nkeys = GET_32BIT(p);
4357 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4360 for (i = 0; i < nkeys; i++) {
4361 static char *pkblob, *alg, *commentp;
4362 static int pklen, alglen, commentlen;
4363 static int siglen, retlen, len;
4364 static char *q, *agentreq, *ret;
4369 sprintf(buf, "Trying Pageant key #%d", i);
4372 pklen = GET_32BIT(p);
4374 if (publickey_blob &&
4375 pklen == publickey_bloblen &&
4376 !memcmp(p, publickey_blob, publickey_bloblen)) {
4377 logevent("This key matches configured key file");
4378 tried_pubkey_config = 1;
4382 alglen = GET_32BIT(pkblob);
4384 commentlen = GET_32BIT(p);
4388 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4389 ssh2_pkt_addstring(username);
4390 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4391 ssh2_pkt_addstring("publickey"); /* method */
4392 ssh2_pkt_addbool(FALSE); /* no signature included */
4393 ssh2_pkt_addstring_start();
4394 ssh2_pkt_addstring_data(alg, alglen);
4395 ssh2_pkt_addstring_start();
4396 ssh2_pkt_addstring_data(pkblob, pklen);
4399 crWaitUntilV(ispkt);
4400 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4401 logevent("Key refused");
4405 if (flags & FLAG_VERBOSE) {
4407 ("Authenticating with public key \"");
4408 c_write(commentp, commentlen);
4409 c_write_str("\" from agent\r\n");
4413 * Server is willing to accept the key.
4414 * Construct a SIGN_REQUEST.
4416 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4417 ssh2_pkt_addstring(username);
4418 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4419 ssh2_pkt_addstring("publickey"); /* method */
4420 ssh2_pkt_addbool(TRUE);
4421 ssh2_pkt_addstring_start();
4422 ssh2_pkt_addstring_data(alg, alglen);
4423 ssh2_pkt_addstring_start();
4424 ssh2_pkt_addstring_data(pkblob, pklen);
4426 siglen = pktout.length - 5 + 4 + 20;
4427 len = 1; /* message type */
4428 len += 4 + pklen; /* key blob */
4429 len += 4 + siglen; /* data to sign */
4430 len += 4; /* flags */
4431 agentreq = smalloc(4 + len);
4432 PUT_32BIT(agentreq, len);
4434 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4435 PUT_32BIT(q, pklen);
4437 memcpy(q, pkblob, pklen);
4439 PUT_32BIT(q, siglen);
4441 /* Now the data to be signed... */
4444 memcpy(q, ssh2_session_id, 20);
4446 memcpy(q, pktout.data + 5, pktout.length - 5);
4447 q += pktout.length - 5;
4448 /* And finally the (zero) flags word. */
4450 agent_query(agentreq, len + 4, &vret, &retlen);
4454 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4455 logevent("Sending Pageant's response");
4456 ssh2_add_sigblob(pkblob, pklen,
4457 ret + 9, GET_32BIT(ret + 5));
4463 ("Pageant failed to answer challenge");
4473 if (!method && can_pubkey && publickey_blob
4474 && !tried_pubkey_config) {
4475 unsigned char *pub_blob;
4476 char *algorithm, *comment;
4479 tried_pubkey_config = TRUE;
4481 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4482 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4485 * Try the public key supplied in the configuration.
4487 * First, offer the public blob to see if the server is
4488 * willing to accept it.
4490 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4493 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4494 ssh2_pkt_addstring(username);
4495 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4496 ssh2_pkt_addstring("publickey"); /* method */
4497 ssh2_pkt_addbool(FALSE); /* no signature included */
4498 ssh2_pkt_addstring(algorithm);
4499 ssh2_pkt_addstring_start();
4500 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4502 logevent("Offered public key"); /* FIXME */
4504 crWaitUntilV(ispkt);
4505 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4507 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4508 continue; /* key refused; give up on it */
4511 logevent("Offer of public key accepted");
4513 * Actually attempt a serious authentication using
4516 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4518 "Passphrase for key \"%.100s\": ",
4524 c_write_str("Authenticating with public key \"");
4525 c_write_str(comment);
4526 c_write_str("\"\r\n");
4527 method = AUTH_PUBLICKEY_FILE;
4531 if (!method && can_keyb_inter && !tried_keyb_inter) {
4532 method = AUTH_KEYBOARD_INTERACTIVE;
4533 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4534 tried_keyb_inter = TRUE;
4536 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4537 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4539 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4540 ssh2_pkt_addstring(username);
4541 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4542 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4543 ssh2_pkt_addstring(""); /* lang */
4544 ssh2_pkt_addstring("");
4547 crWaitUntilV(ispkt);
4548 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4549 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4551 logevent("Keyboard-interactive authentication refused");
4552 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4556 kbd_inter_running = TRUE;
4560 if (kbd_inter_running) {
4561 method = AUTH_KEYBOARD_INTERACTIVE;
4562 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4563 tried_keyb_inter = TRUE;
4565 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4566 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4568 if (curr_prompt == 0) {
4570 * We've got a fresh USERAUTH_INFO_REQUEST.
4571 * Display header data, and start going through
4574 char *name, *inst, *lang;
4575 int name_len, inst_len, lang_len;
4577 ssh2_pkt_getstring(&name, &name_len);
4578 ssh2_pkt_getstring(&inst, &inst_len);
4579 ssh2_pkt_getstring(&lang, &lang_len);
4581 c_write_untrusted(name, name_len);
4585 c_write_untrusted(inst, inst_len);
4588 num_prompts = ssh2_pkt_getuint32();
4592 * If there are prompts remaining in the packet,
4593 * display one and get a response.
4595 if (curr_prompt < num_prompts) {
4599 ssh2_pkt_getstring(&prompt, &prompt_len);
4600 if (prompt_len > 0) {
4601 strncpy(pwprompt, prompt, sizeof(pwprompt));
4602 pwprompt[prompt_len < sizeof(pwprompt) ?
4603 prompt_len : sizeof(pwprompt)-1] = '\0';
4606 "<server failed to send prompt>: ");
4608 echo = ssh2_pkt_getbool();
4614 if (!method && can_passwd) {
4615 method = AUTH_PASSWORD;
4616 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4617 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4618 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4625 if (!ssh_get_line(pwprompt, password,
4626 sizeof(password), TRUE)) {
4628 * get_line failed to get a password (for
4629 * example because one was supplied on the
4630 * command line which has already failed to
4633 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4634 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4636 ("No more passwords available to try");
4637 ssh2_pkt_addstring("en"); /* language tag */
4639 logevent("Unable to authenticate");
4640 connection_fatal("Unable to authenticate");
4641 ssh_state = SSH_STATE_CLOSED;
4648 c_write_untrusted(pwprompt, strlen(pwprompt));
4653 crWaitUntilV(!ispkt);
4655 switch (c = *in++) {
4675 if (pos < sizeof(password)-1)
4676 password[pos++] = c;
4680 c_write_str("\r\n");
4684 if (method == AUTH_PUBLICKEY_FILE) {
4686 * We have our passphrase. Now try the actual authentication.
4688 struct ssh2_userkey *key;
4690 key = ssh2_load_userkey(cfg.keyfile, password);
4691 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4692 if (key == SSH2_WRONG_PASSPHRASE) {
4693 c_write_str("Wrong passphrase\r\n");
4694 tried_pubkey_config = FALSE;
4696 c_write_str("Unable to load private key\r\n");
4697 tried_pubkey_config = TRUE;
4699 /* Send a spurious AUTH_NONE to return to the top. */
4700 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4701 ssh2_pkt_addstring(username);
4702 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4703 ssh2_pkt_addstring("none"); /* method */
4705 type = AUTH_TYPE_NONE;
4707 unsigned char *pkblob, *sigblob, *sigdata;
4708 int pkblob_len, sigblob_len, sigdata_len;
4711 * We have loaded the private key and the server
4712 * has announced that it's willing to accept it.
4713 * Hallelujah. Generate a signature and send it.
4715 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4716 ssh2_pkt_addstring(username);
4717 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4718 ssh2_pkt_addstring("publickey"); /* method */
4719 ssh2_pkt_addbool(TRUE);
4720 ssh2_pkt_addstring(key->alg->name);
4721 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4722 ssh2_pkt_addstring_start();
4723 ssh2_pkt_addstring_data(pkblob, pkblob_len);
4726 * The data to be signed is:
4730 * followed by everything so far placed in the
4733 sigdata_len = pktout.length - 5 + 4 + 20;
4734 sigdata = smalloc(sigdata_len);
4735 PUT_32BIT(sigdata, 20);
4736 memcpy(sigdata + 4, ssh2_session_id, 20);
4737 memcpy(sigdata + 24, pktout.data + 5,
4739 sigblob = key->alg->sign(key->data, sigdata,
4740 sigdata_len, &sigblob_len);
4741 ssh2_add_sigblob(pkblob, pkblob_len,
4742 sigblob, sigblob_len);
4748 type = AUTH_TYPE_PUBLICKEY;
4750 } else if (method == AUTH_PASSWORD) {
4752 * We send the password packet lumped tightly together with
4753 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4754 * string long enough to make the total length of the two
4755 * packets constant. This should ensure that a passive
4756 * listener doing traffic analyis can't work out the length
4759 * For this to work, we need an assumption about the
4760 * maximum length of the password packet. I think 256 is
4761 * pretty conservative. Anyone using a password longer than
4762 * that probably doesn't have much to worry about from
4763 * people who find out how long their password is!
4765 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4766 ssh2_pkt_addstring(username);
4767 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4768 ssh2_pkt_addstring("password");
4769 ssh2_pkt_addbool(FALSE);
4770 ssh2_pkt_addstring(password);
4773 * We'll include a string that's an exact multiple of the
4774 * cipher block size. If the cipher is NULL for some
4775 * reason, we don't do this trick at all because we gain
4781 stringlen = (256 - deferred_len);
4782 stringlen += cscipher->blksize - 1;
4783 stringlen -= (stringlen % cscipher->blksize);
4786 * Temporarily disable actual compression,
4787 * so we can guarantee to get this string
4788 * exactly the length we want it. The
4789 * compression-disabling routine should
4790 * return an integer indicating how many
4791 * bytes we should adjust our string length
4794 stringlen -= cscomp->disable_compression();
4796 ssh2_pkt_init(SSH2_MSG_IGNORE);
4797 ssh2_pkt_addstring_start();
4798 for (i = 0; i < stringlen; i++) {
4799 char c = (char) random_byte();
4800 ssh2_pkt_addstring_data(&c, 1);
4804 ssh_pkt_defersend();
4805 logevent("Sent password");
4806 type = AUTH_TYPE_PASSWORD;
4807 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4808 if (curr_prompt == 0) {
4809 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4810 ssh2_pkt_adduint32(num_prompts);
4812 if (need_pw) { /* only add pw if we just got one! */
4813 ssh2_pkt_addstring(password);
4814 memset(password, 0, sizeof(password));
4817 if (curr_prompt >= num_prompts) {
4821 * If there are prompts remaining, we set
4822 * `gotit' so that we won't attempt to get
4823 * another packet. Then we go back round the
4824 * loop and will end up retrieving another
4825 * prompt out of the existing packet. Funky or
4830 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4833 ("No supported authentication methods left to try!\r\n");
4835 ("No supported authentications offered. Disconnecting");
4836 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4837 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4839 ("No supported authentication methods available");
4840 ssh2_pkt_addstring("en"); /* language tag */
4842 ssh_state = SSH_STATE_CLOSED;
4846 } while (!we_are_in);
4849 * Now we're authenticated for the connection protocol. The
4850 * connection protocol will automatically have started at this
4851 * point; there's no need to send SERVICE_REQUEST.
4855 * So now create a channel with a session in it.
4857 ssh_channels = newtree234(ssh_channelcmp);
4858 mainchan = smalloc(sizeof(struct ssh_channel));
4859 mainchan->localid = alloc_channel_id();
4860 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4861 ssh2_pkt_addstring("session");
4862 ssh2_pkt_adduint32(mainchan->localid);
4863 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4864 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4865 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4867 crWaitUntilV(ispkt);
4868 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4869 bombout(("Server refused to open a session"));
4871 /* FIXME: error data comes back in FAILURE packet */
4873 if (ssh2_pkt_getuint32() != mainchan->localid) {
4874 bombout(("Server's channel confirmation cited wrong channel"));
4877 mainchan->remoteid = ssh2_pkt_getuint32();
4878 mainchan->type = CHAN_MAINSESSION;
4879 mainchan->closes = 0;
4880 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4881 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4882 bufchain_init(&mainchan->v.v2.outbuffer);
4883 add234(ssh_channels, mainchan);
4884 logevent("Opened channel for session");
4887 * Potentially enable X11 forwarding.
4889 if (cfg.x11_forward) {
4890 char proto[20], data[64];
4891 logevent("Requesting X11 forwarding");
4892 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4893 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4894 ssh2_pkt_adduint32(mainchan->remoteid);
4895 ssh2_pkt_addstring("x11-req");
4896 ssh2_pkt_addbool(1); /* want reply */
4897 ssh2_pkt_addbool(0); /* many connections */
4898 ssh2_pkt_addstring(proto);
4899 ssh2_pkt_addstring(data);
4900 ssh2_pkt_adduint32(0); /* screen number */
4904 crWaitUntilV(ispkt);
4905 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4906 unsigned i = ssh2_pkt_getuint32();
4907 struct ssh_channel *c;
4908 c = find234(ssh_channels, &i, ssh_channelfind);
4910 continue; /* nonexistent channel */
4911 c->v.v2.remwindow += ssh2_pkt_getuint32();
4913 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4915 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4916 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4917 bombout(("Unexpected response to X11 forwarding request:"
4918 " packet type %d", pktin.type));
4921 logevent("X11 forwarding refused");
4923 logevent("X11 forwarding enabled");
4924 ssh_X11_fwd_enabled = TRUE;
4929 * Enable port forwardings.
4932 static char *e; /* preserve across crReturn */
4935 int sport,dport,sserv,dserv;
4936 char sports[256], dports[256], host[256];
4940 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4941 /* Add port forwardings. */
4946 while (*e && *e != '\t')
4952 while (*e && *e != ':')
4962 dport = atoi(dports);
4966 se = getservbyname(dports, NULL);
4968 dport = ntohs(se->s_port);
4971 "Service lookup failed for destination port \"%s\"",
4976 sport = atoi(sports);
4980 se = getservbyname(sports, NULL);
4982 sport = ntohs(se->s_port);
4985 "Service lookup failed for source port \"%s\"",
4990 if (sport && dport) {
4992 pfd_addforward(host, dport, sport);
4993 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
4994 " %s:%.*s%.*s%d%.*s",
4995 sserv ? strlen(sports) : 0, sports,
4996 sserv, "(", sport, sserv, ")",
4998 dserv ? strlen(dports) : 0, dports,
4999 dserv, "(", dport, dserv, ")");
5002 struct ssh_rportfwd *pf;
5003 pf = smalloc(sizeof(*pf));
5004 strcpy(pf->dhost, host);
5007 if (add234(ssh_rportfwds, pf) != pf) {
5009 "Duplicate remote port forwarding to %s:%d",
5014 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5015 " forward to %s:%.*s%.*s%d%.*s",
5016 sserv ? strlen(sports) : 0, sports,
5017 sserv, "(", sport, sserv, ")",
5019 dserv ? strlen(dports) : 0, dports,
5020 dserv, "(", dport, dserv, ")");
5022 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5023 ssh2_pkt_addstring("tcpip-forward");
5024 ssh2_pkt_addbool(1);/* want reply */
5025 if (cfg.rport_acceptall)
5026 ssh2_pkt_addstring("0.0.0.0");
5028 ssh2_pkt_addstring("127.0.0.1");
5029 ssh2_pkt_adduint32(sport);
5033 crWaitUntilV(ispkt);
5034 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5035 unsigned i = ssh2_pkt_getuint32();
5036 struct ssh_channel *c;
5037 c = find234(ssh_channels, &i, ssh_channelfind);
5039 continue;/* nonexistent channel */
5040 c->v.v2.remwindow += ssh2_pkt_getuint32();
5042 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5044 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5045 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5046 bombout(("Unexpected response to port "
5047 "forwarding request: packet type %d",
5051 logevent("Server refused this port forwarding");
5053 logevent("Remote port forwarding enabled");
5062 * Potentially enable agent forwarding.
5064 if (cfg.agentfwd && agent_exists()) {
5065 logevent("Requesting OpenSSH-style agent forwarding");
5066 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5067 ssh2_pkt_adduint32(mainchan->remoteid);
5068 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5069 ssh2_pkt_addbool(1); /* want reply */
5073 crWaitUntilV(ispkt);
5074 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5075 unsigned i = ssh2_pkt_getuint32();
5076 struct ssh_channel *c;
5077 c = find234(ssh_channels, &i, ssh_channelfind);
5079 continue; /* nonexistent channel */
5080 c->v.v2.remwindow += ssh2_pkt_getuint32();
5082 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5084 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5085 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5086 bombout(("Unexpected response to agent forwarding request:"
5087 " packet type %d", pktin.type));
5090 logevent("Agent forwarding refused");
5092 logevent("Agent forwarding enabled");
5093 ssh_agentfwd_enabled = TRUE;
5098 * Now allocate a pty for the session.
5101 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5102 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5103 ssh2_pkt_addstring("pty-req");
5104 ssh2_pkt_addbool(1); /* want reply */
5105 ssh2_pkt_addstring(cfg.termtype);
5106 ssh2_pkt_adduint32(cols);
5107 ssh2_pkt_adduint32(rows);
5108 ssh2_pkt_adduint32(0); /* pixel width */
5109 ssh2_pkt_adduint32(0); /* pixel height */
5110 ssh2_pkt_addstring_start();
5111 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5113 ssh_state = SSH_STATE_INTERMED;
5116 crWaitUntilV(ispkt);
5117 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5118 unsigned i = ssh2_pkt_getuint32();
5119 struct ssh_channel *c;
5120 c = find234(ssh_channels, &i, ssh_channelfind);
5122 continue; /* nonexistent channel */
5123 c->v.v2.remwindow += ssh2_pkt_getuint32();
5125 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5127 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5128 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5129 bombout(("Unexpected response to pty request:"
5130 " packet type %d", pktin.type));
5133 c_write_str("Server refused to allocate pty\r\n");
5134 ssh_editing = ssh_echoing = 1;
5136 logevent("Allocated pty");
5139 ssh_editing = ssh_echoing = 1;
5143 * Start a shell or a remote command. We may have to attempt
5144 * this twice if the config data has provided a second choice
5151 if (ssh_fallback_cmd) {
5152 subsys = cfg.ssh_subsys2;
5153 cmd = cfg.remote_cmd_ptr2;
5155 subsys = cfg.ssh_subsys;
5156 cmd = cfg.remote_cmd_ptr;
5159 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5160 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5162 ssh2_pkt_addstring("subsystem");
5163 ssh2_pkt_addbool(1); /* want reply */
5164 ssh2_pkt_addstring(cmd);
5166 ssh2_pkt_addstring("exec");
5167 ssh2_pkt_addbool(1); /* want reply */
5168 ssh2_pkt_addstring(cmd);
5170 ssh2_pkt_addstring("shell");
5171 ssh2_pkt_addbool(1); /* want reply */
5175 crWaitUntilV(ispkt);
5176 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5177 unsigned i = ssh2_pkt_getuint32();
5178 struct ssh_channel *c;
5179 c = find234(ssh_channels, &i, ssh_channelfind);
5181 continue; /* nonexistent channel */
5182 c->v.v2.remwindow += ssh2_pkt_getuint32();
5184 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5185 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5186 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5187 bombout(("Unexpected response to shell/command request:"
5188 " packet type %d", pktin.type));
5192 * We failed to start the command. If this is the
5193 * fallback command, we really are finished; if it's
5194 * not, and if the fallback command exists, try falling
5195 * back to it before complaining.
5197 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5198 logevent("Primary command failed; attempting fallback");
5199 ssh_fallback_cmd = TRUE;
5202 bombout(("Server refused to start a shell/command"));
5205 logevent("Started a shell/command");
5210 ssh_state = SSH_STATE_SESSION;
5214 ssh_special(TS_EOF);
5219 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
5222 static int try_send;
5226 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
5227 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5230 unsigned i = ssh2_pkt_getuint32();
5231 struct ssh_channel *c;
5232 c = find234(ssh_channels, &i, ssh_channelfind);
5234 continue; /* nonexistent channel */
5235 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5236 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5237 continue; /* extended but not stderr */
5238 ssh2_pkt_getstring(&data, &length);
5241 c->v.v2.locwindow -= length;
5243 case CHAN_MAINSESSION:
5245 from_backend(pktin.type ==
5246 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5250 bufsize = x11_send(c->u.x11.s, data, length);
5253 bufsize = pfd_send(c->u.pfd.s, data, length);
5256 while (length > 0) {
5257 if (c->u.a.lensofar < 4) {
5258 int l = min(4 - c->u.a.lensofar, length);
5259 memcpy(c->u.a.msglen + c->u.a.lensofar,
5263 c->u.a.lensofar += l;
5265 if (c->u.a.lensofar == 4) {
5267 4 + GET_32BIT(c->u.a.msglen);
5268 c->u.a.message = smalloc(c->u.a.totallen);
5269 memcpy(c->u.a.message, c->u.a.msglen, 4);
5271 if (c->u.a.lensofar >= 4 && length > 0) {
5273 min(c->u.a.totallen - c->u.a.lensofar,
5275 memcpy(c->u.a.message + c->u.a.lensofar,
5279 c->u.a.lensofar += l;
5281 if (c->u.a.lensofar == c->u.a.totallen) {
5282 void *reply, *sentreply;
5284 agent_query(c->u.a.message,
5285 c->u.a.totallen, &reply,
5290 /* Fake SSH_AGENT_FAILURE. */
5291 sentreply = "\0\0\0\1\5";
5294 ssh2_add_channel_data(c, sentreply,
5299 sfree(c->u.a.message);
5300 c->u.a.lensofar = 0;
5307 * If we are not buffering too much data,
5308 * enlarge the window again at the remote side.
5310 if (bufsize < OUR_V2_WINSIZE)
5311 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5313 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
5314 ssh_state = SSH_STATE_CLOSED;
5315 logevent("Received disconnect message");
5317 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
5318 unsigned i = ssh2_pkt_getuint32();
5319 struct ssh_channel *c;
5321 c = find234(ssh_channels, &i, ssh_channelfind);
5323 continue; /* nonexistent channel */
5325 if (c->type == CHAN_X11) {
5327 * Remote EOF on an X11 channel means we should
5328 * wrap up and close the channel ourselves.
5330 x11_close(c->u.x11.s);
5332 } else if (c->type == CHAN_AGENT) {
5334 } else if (c->type == CHAN_SOCKDATA) {
5335 pfd_close(c->u.pfd.s);
5338 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5339 unsigned i = ssh2_pkt_getuint32();
5340 struct ssh_channel *c;
5342 c = find234(ssh_channels, &i, ssh_channelfind);
5344 continue; /* nonexistent channel */
5345 /* Do pre-close processing on the channel. */
5347 case CHAN_MAINSESSION:
5348 break; /* nothing to see here, move along */
5350 if (c->u.x11.s != NULL)
5351 x11_close(c->u.x11.s);
5358 if (c->u.pfd.s != NULL)
5359 pfd_close(c->u.pfd.s);
5363 if (c->closes == 0) {
5364 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5365 ssh2_pkt_adduint32(c->remoteid);
5368 del234(ssh_channels, c);
5369 bufchain_clear(&c->v.v2.outbuffer);
5373 * See if that was the last channel left open.
5375 if (count234(ssh_channels) == 0) {
5378 * We used to send SSH_MSG_DISCONNECT here,
5379 * because I'd believed that _every_ conforming
5380 * SSH2 connection had to end with a disconnect
5381 * being sent by at least one side; apparently
5382 * I was wrong and it's perfectly OK to
5383 * unceremoniously slam the connection shut
5384 * when you're done, and indeed OpenSSH feels
5385 * this is more polite than sending a
5386 * DISCONNECT. So now we don't.
5388 logevent("All channels closed. Disconnecting");
5389 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5390 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5391 ssh2_pkt_addstring("All open channels closed");
5392 ssh2_pkt_addstring("en"); /* language tag */
5395 ssh_state = SSH_STATE_CLOSED;
5398 continue; /* remote sends close; ignore (FIXME) */
5399 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5400 unsigned i = ssh2_pkt_getuint32();
5401 struct ssh_channel *c;
5402 c = find234(ssh_channels, &i, ssh_channelfind);
5404 continue; /* nonexistent channel */
5405 c->v.v2.remwindow += ssh2_pkt_getuint32();
5407 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5408 unsigned i = ssh2_pkt_getuint32();
5409 struct ssh_channel *c;
5410 c = find234(ssh_channels, &i, ssh_channelfind);
5412 continue; /* nonexistent channel */
5413 if (c->type != CHAN_SOCKDATA_DORMANT)
5414 continue; /* dunno why they're confirming this */
5415 c->remoteid = ssh2_pkt_getuint32();
5416 c->type = CHAN_SOCKDATA;
5417 c->v.v2.remwindow = ssh2_pkt_getuint32();
5418 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5420 pfd_confirm(c->u.pfd.s);
5423 * We have a pending close on this channel,
5424 * which we decided on before the server acked
5425 * the channel open. So now we know the
5426 * remoteid, we can close it again.
5428 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5429 ssh2_pkt_adduint32(c->remoteid);
5432 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5433 unsigned i = ssh2_pkt_getuint32();
5434 struct ssh_channel *c;
5435 c = find234(ssh_channels, &i, ssh_channelfind);
5437 continue; /* nonexistent channel */
5438 if (c->type != CHAN_SOCKDATA_DORMANT)
5439 continue; /* dunno why they're failing this */
5441 logevent("Forwarded connection refused by server");
5443 pfd_close(c->u.pfd.s);
5445 del234(ssh_channels, c);
5447 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5450 int typelen, want_reply;
5451 struct ssh_channel *c;
5453 localid = ssh2_pkt_getuint32();
5454 ssh2_pkt_getstring(&type, &typelen);
5455 want_reply = ssh2_pkt_getbool();
5458 * First, check that the channel exists. Otherwise,
5459 * we can instantly disconnect with a rude message.
5461 c = find234(ssh_channels, &localid, ssh_channelfind);
5464 sprintf(buf, "Received channel request for nonexistent"
5465 " channel %d", localid);
5467 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5468 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5469 ssh2_pkt_addstring(buf);
5470 ssh2_pkt_addstring("en"); /* language tag */
5472 connection_fatal("%s", buf);
5473 ssh_state = SSH_STATE_CLOSED;
5478 * Having got the channel number, we now look at
5479 * the request type string to see if it's something
5482 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5484 /* We recognise "exit-status" on the primary channel. */
5486 ssh_exitcode = ssh2_pkt_getuint32();
5487 sprintf(buf, "Server sent command exit status %d",
5491 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5492 ssh2_pkt_adduint32(c->remoteid);
5497 * This is a channel request we don't know
5498 * about, so we now either ignore the request
5499 * or respond with CHANNEL_FAILURE, depending
5503 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5504 ssh2_pkt_adduint32(c->remoteid);
5508 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5510 int typelen, want_reply;
5512 ssh2_pkt_getstring(&type, &typelen);
5513 want_reply = ssh2_pkt_getbool();
5516 * We currently don't support any global requests
5517 * at all, so we either ignore the request or
5518 * respond with REQUEST_FAILURE, depending on
5522 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5525 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5529 struct ssh_channel *c;
5530 unsigned remid, winsize, pktsize;
5531 ssh2_pkt_getstring(&type, &typelen);
5532 c = smalloc(sizeof(struct ssh_channel));
5534 remid = ssh2_pkt_getuint32();
5535 winsize = ssh2_pkt_getuint32();
5536 pktsize = ssh2_pkt_getuint32();
5538 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5539 if (!ssh_X11_fwd_enabled)
5540 error = "X11 forwarding is not enabled";
5541 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5543 error = "Unable to open an X11 connection";
5547 } else if (typelen == 15 &&
5548 !memcmp(type, "forwarded-tcpip", 15)) {
5549 struct ssh_rportfwd pf, *realpf;
5552 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5553 pf.sport = ssh2_pkt_getuint32();
5554 realpf = find234(ssh_rportfwds, &pf, NULL);
5555 if (realpf == NULL) {
5556 error = "Remote port is not recognised";
5558 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5561 sprintf(buf, "Received remote port open request for %s:%d",
5562 realpf->dhost, realpf->dport);
5565 sprintf(buf, "Port open failed: %s", e);
5567 error = "Port open failed";
5569 logevent("Forwarded port opened successfully");
5570 c->type = CHAN_SOCKDATA;
5573 } else if (typelen == 22 &&
5574 !memcmp(type, "auth-agent@openssh.com", 3)) {
5575 if (!ssh_agentfwd_enabled)
5576 error = "Agent forwarding is not enabled";
5578 c->type = CHAN_AGENT; /* identify channel type */
5579 c->u.a.lensofar = 0;
5582 error = "Unsupported channel type requested";
5585 c->remoteid = remid;
5587 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5588 ssh2_pkt_adduint32(c->remoteid);
5589 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5590 ssh2_pkt_addstring(error);
5591 ssh2_pkt_addstring("en"); /* language tag */
5595 c->localid = alloc_channel_id();
5597 c->v.v2.locwindow = OUR_V2_WINSIZE;
5598 c->v.v2.remwindow = winsize;
5599 c->v.v2.remmaxpkt = pktsize;
5600 bufchain_init(&c->v.v2.outbuffer);
5601 add234(ssh_channels, c);
5602 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5603 ssh2_pkt_adduint32(c->remoteid);
5604 ssh2_pkt_adduint32(c->localid);
5605 ssh2_pkt_adduint32(c->v.v2.locwindow);
5606 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5610 bombout(("Strange packet received: type %d", pktin.type));
5615 * We have spare data. Add it to the channel buffer.
5617 ssh2_add_channel_data(mainchan, in, inlen);
5622 struct ssh_channel *c;
5624 * Try to send data on all channels if we can.
5626 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5627 int bufsize = ssh2_try_send(c);
5630 case CHAN_MAINSESSION:
5631 /* stdin need not receive an unthrottle
5632 * notification since it will be polled */
5635 x11_unthrottle(c->u.x11.s);
5638 /* agent sockets are request/response and need no
5639 * buffer management */
5642 pfd_unthrottle(c->u.pfd.s);
5654 * Handle the top-level SSH2 protocol.
5656 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5658 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5660 do_ssh2_authconn(in, inlen, ispkt);
5664 * Called to set up the connection.
5666 * Returns an error message, or NULL on success.
5668 static char *ssh_init(char *host, int port, char **realhost, int nodelay)
5673 if (crypto_startup() == 0)
5674 return "Microsoft high encryption pack not installed!";
5680 ssh1_throttle_count = 0;
5681 ssh_overall_bufsize = 0;
5682 ssh_fallback_cmd = 0;
5684 p = connect_to_host(host, port, realhost, nodelay);
5692 * Called to send data down the Telnet connection.
5694 static int ssh_send(char *buf, int len)
5696 if (s == NULL || ssh_protocol == NULL)
5699 ssh_protocol(buf, len, 0);
5701 return ssh_sendbuffer();
5705 * Called to query the current amount of buffered stdin data.
5707 static int ssh_sendbuffer(void)
5711 if (s == NULL || ssh_protocol == NULL)
5715 * If the SSH socket itself has backed up, add the total backup
5716 * size on that to any individual buffer on the stdin channel.
5719 if (ssh_throttled_all)
5720 override_value = ssh_overall_bufsize;
5722 if (ssh_version == 1) {
5723 return override_value;
5724 } else if (ssh_version == 2) {
5725 if (!mainchan || mainchan->closes > 0)
5726 return override_value;
5728 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5735 * Called to set the size of the window from SSH's POV.
5737 static void ssh_size(void)
5739 switch (ssh_state) {
5740 case SSH_STATE_BEFORE_SIZE:
5741 case SSH_STATE_PREPACKET:
5742 case SSH_STATE_CLOSED:
5743 break; /* do nothing */
5744 case SSH_STATE_INTERMED:
5745 size_needed = TRUE; /* buffer for later */
5747 case SSH_STATE_SESSION:
5749 if (ssh_version == 1) {
5750 send_packet(SSH1_CMSG_WINDOW_SIZE,
5751 PKT_INT, rows, PKT_INT, cols,
5752 PKT_INT, 0, PKT_INT, 0, PKT_END);
5754 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5755 ssh2_pkt_adduint32(mainchan->remoteid);
5756 ssh2_pkt_addstring("window-change");
5757 ssh2_pkt_addbool(0);
5758 ssh2_pkt_adduint32(cols);
5759 ssh2_pkt_adduint32(rows);
5760 ssh2_pkt_adduint32(0);
5761 ssh2_pkt_adduint32(0);
5770 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5771 * can send an EOF and collect resulting output (e.g. `plink
5774 static void ssh_special(Telnet_Special code)
5776 if (code == TS_EOF) {
5777 if (ssh_state != SSH_STATE_SESSION) {
5779 * Buffer the EOF in case we are pre-SESSION, so we can
5780 * send it as soon as we reach SESSION.
5786 if (ssh_version == 1) {
5787 send_packet(SSH1_CMSG_EOF, PKT_END);
5789 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5790 ssh2_pkt_adduint32(mainchan->remoteid);
5793 logevent("Sent EOF message");
5794 } else if (code == TS_PING) {
5795 if (ssh_state == SSH_STATE_CLOSED
5796 || ssh_state == SSH_STATE_PREPACKET) return;
5797 if (ssh_version == 1) {
5798 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5800 ssh2_pkt_init(SSH2_MSG_IGNORE);
5801 ssh2_pkt_addstring_start();
5809 void *new_sock_channel(Socket s)
5811 struct ssh_channel *c;
5812 c = smalloc(sizeof(struct ssh_channel));
5815 c->remoteid = -1; /* to be set when open confirmed */
5816 c->localid = alloc_channel_id();
5818 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5820 bufchain_init(&c->v.v2.outbuffer);
5821 add234(ssh_channels, c);
5827 * This is called when stdout/stderr (the entity to which
5828 * from_backend sends data) manages to clear some backlog.
5830 void ssh_unthrottle(int bufsize)
5832 if (ssh_version == 1) {
5833 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5834 ssh1_stdout_throttling = 0;
5838 if (mainchan && mainchan->closes == 0)
5839 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5843 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5845 struct ssh_channel *c = (struct ssh_channel *)channel;
5848 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5851 if (ssh_version == 1) {
5852 send_packet(SSH1_MSG_PORT_OPEN,
5853 PKT_INT, c->localid,
5856 //PKT_STR, <org:orgport>,
5859 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5860 ssh2_pkt_addstring("direct-tcpip");
5861 ssh2_pkt_adduint32(c->localid);
5862 c->v.v2.locwindow = OUR_V2_WINSIZE;
5863 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5864 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5865 ssh2_pkt_addstring(hostname);
5866 ssh2_pkt_adduint32(port);
5868 * We make up values for the originator data; partly it's
5869 * too much hassle to keep track, and partly I'm not
5870 * convinced the server should be told details like that
5871 * about my local network configuration.
5873 ssh2_pkt_addstring("client-side-connection");
5874 ssh2_pkt_adduint32(0);
5880 static Socket ssh_socket(void)
5885 static int ssh_sendok(void)
5890 static int ssh_ldisc(int option)
5892 if (option == LD_ECHO)
5894 if (option == LD_EDIT)
5899 static int ssh_return_exitcode(void)
5901 return ssh_exitcode;
5904 Backend ssh_backend = {
5911 ssh_return_exitcode,