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 * _Completely_ silly lengths should be stomped on before they
889 * do us any more damage.
891 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
892 bombout(("Incoming packet was garbled on decryption"));
897 * This enables us to deduce the payload length.
899 st->payload = st->len - st->pad - 1;
901 pktin.length = st->payload + 5;
904 * So now we can work out the total packet length.
906 st->packetlen = st->len + 4;
907 st->maclen = scmac ? scmac->len : 0;
910 * Adjust memory allocation if packet is too big.
912 if (pktin.maxlen < st->packetlen + st->maclen) {
913 pktin.maxlen = st->packetlen + st->maclen;
916 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
921 fatalbox("Out of memory");
925 * Read and decrypt the remainder of the packet.
927 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
929 while ((*datalen) == 0)
930 crReturn(st->packetlen + st->maclen - st->i);
931 pktin.data[st->i] = *(*data)++;
934 /* Decrypt everything _except_ the MAC. */
936 sccipher->decrypt(pktin.data + st->cipherblk,
937 st->packetlen - st->cipherblk);
943 && !scmac->verify(pktin.data, st->len + 4,
944 st->incoming_sequence)) {
945 bombout(("Incorrect MAC received on packet"));
948 st->incoming_sequence++; /* whether or not we MACed */
951 * Decompress packet payload.
954 unsigned char *newpayload;
956 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
957 &newpayload, &newlen)) {
958 if (pktin.maxlen < newlen + 5) {
959 pktin.maxlen = newlen + 5;
962 NULL ? smalloc(pktin.maxlen +
963 APIEXTRA) : srealloc(pktin.data,
967 fatalbox("Out of memory");
969 pktin.length = 5 + newlen;
970 memcpy(pktin.data + 5, newpayload, newlen);
976 pktin.type = pktin.data[5];
978 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
979 pktin.data+6, pktin.length-6);
981 switch (pktin.type) {
983 * These packets we must handle instantly.
985 case SSH2_MSG_DISCONNECT:
987 /* log reason code in disconnect message */
989 int reason = GET_32BIT(pktin.data + 6);
990 unsigned msglen = GET_32BIT(pktin.data + 10);
992 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
993 sprintf(buf, "Received disconnect message (%s)",
994 ssh2_disconnect_reasons[reason]);
996 sprintf(buf, "Received disconnect message (unknown type %d)",
1000 strcpy(buf, "Disconnection message text: ");
1001 nowlen = strlen(buf);
1002 if (msglen > sizeof(buf) - nowlen - 1)
1003 msglen = sizeof(buf) - nowlen - 1;
1004 memcpy(buf + nowlen, pktin.data + 14, msglen);
1005 buf[nowlen + msglen] = '\0';
1007 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1009 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1010 ssh2_disconnect_reasons[reason] : "unknown",
1015 case SSH2_MSG_IGNORE:
1017 case SSH2_MSG_DEBUG:
1019 /* log the debug message */
1021 /* int display = pktin.body[6]; */
1022 int stringlen = GET_32BIT(pktin.data+7);
1024 strcpy(buf, "Remote debug message: ");
1025 prefix = strlen(buf);
1026 if (stringlen > sizeof(buf)-prefix-1)
1027 stringlen = sizeof(buf)-prefix-1;
1028 memcpy(buf + prefix, pktin.data + 11, stringlen);
1029 buf[prefix + stringlen] = '\0';
1032 goto next_packet; /* FIXME: print the debug message */
1035 * These packets we need do nothing about here.
1037 case SSH2_MSG_UNIMPLEMENTED:
1038 case SSH2_MSG_SERVICE_REQUEST:
1039 case SSH2_MSG_SERVICE_ACCEPT:
1040 case SSH2_MSG_KEXINIT:
1041 case SSH2_MSG_NEWKEYS:
1042 case SSH2_MSG_KEXDH_INIT:
1043 case SSH2_MSG_KEXDH_REPLY:
1044 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1045 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1046 case SSH2_MSG_KEX_DH_GEX_INIT:
1047 case SSH2_MSG_KEX_DH_GEX_REPLY:
1048 case SSH2_MSG_USERAUTH_REQUEST:
1049 case SSH2_MSG_USERAUTH_FAILURE:
1050 case SSH2_MSG_USERAUTH_SUCCESS:
1051 case SSH2_MSG_USERAUTH_BANNER:
1052 case SSH2_MSG_USERAUTH_PK_OK:
1053 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1054 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1055 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1056 case SSH2_MSG_GLOBAL_REQUEST:
1057 case SSH2_MSG_REQUEST_SUCCESS:
1058 case SSH2_MSG_REQUEST_FAILURE:
1059 case SSH2_MSG_CHANNEL_OPEN:
1060 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1061 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1062 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1063 case SSH2_MSG_CHANNEL_DATA:
1064 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1065 case SSH2_MSG_CHANNEL_EOF:
1066 case SSH2_MSG_CHANNEL_CLOSE:
1067 case SSH2_MSG_CHANNEL_REQUEST:
1068 case SSH2_MSG_CHANNEL_SUCCESS:
1069 case SSH2_MSG_CHANNEL_FAILURE:
1073 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1076 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
1077 ssh2_pkt_adduint32(st->incoming_sequence - 1);
1085 static void ssh1_pktout_size(int len)
1089 len += 5; /* type and CRC */
1090 pad = 8 - (len % 8);
1093 pktout.length = len - 5;
1094 if (pktout.maxlen < biglen) {
1095 pktout.maxlen = biglen;
1097 /* Allocate enough buffer space for extra block
1098 * for MS CryptEncrypt() */
1099 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
1100 srealloc(pktout.data, biglen + 12));
1102 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
1103 srealloc(pktout.data, biglen + 4));
1106 fatalbox("Out of memory");
1108 pktout.body = pktout.data + 4 + pad + 1;
1111 static void s_wrpkt_start(int type, int len)
1113 ssh1_pktout_size(len);
1117 static int s_wrpkt_prepare(void)
1119 int pad, len, biglen, i;
1122 pktout.body[-1] = pktout.type;
1124 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1125 pktout.body, pktout.length);
1127 if (ssh1_compressing) {
1128 unsigned char *compblk;
1130 zlib_compress_block(pktout.body - 1, pktout.length + 1,
1131 &compblk, &complen);
1132 ssh1_pktout_size(complen - 1);
1133 memcpy(pktout.body - 1, compblk, complen);
1137 len = pktout.length + 5; /* type and CRC */
1138 pad = 8 - (len % 8);
1141 for (i = 0; i < pad; i++)
1142 pktout.data[i + 4] = random_byte();
1143 crc = crc32(pktout.data + 4, biglen - 4);
1144 PUT_32BIT(pktout.data + biglen, crc);
1145 PUT_32BIT(pktout.data, len);
1148 cipher->encrypt(pktout.data + 4, biglen);
1153 static void s_wrpkt(void)
1156 len = s_wrpkt_prepare();
1157 backlog = sk_write(s, pktout.data, len);
1158 if (backlog > SSH_MAX_BACKLOG)
1159 ssh_throttle_all(1, backlog);
1162 static void s_wrpkt_defer(void)
1165 len = s_wrpkt_prepare();
1166 if (deferred_len + len > deferred_size) {
1167 deferred_size = deferred_len + len + 128;
1168 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1170 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1171 deferred_len += len;
1175 * Construct a packet with the specified contents.
1177 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1179 unsigned char *p, *argp, argchar;
1180 unsigned long argint;
1181 int pktlen, argtype, arglen;
1185 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1188 (void) va_arg(ap1, int);
1192 (void) va_arg(ap1, char);
1196 (void) va_arg(ap1, unsigned char *);
1197 arglen = va_arg(ap1, int);
1201 argp = va_arg(ap1, unsigned char *);
1202 arglen = strlen(argp);
1203 pktlen += 4 + arglen;
1206 bn = va_arg(ap1, Bignum);
1207 pktlen += ssh1_bignum_length(bn);
1214 s_wrpkt_start(pkttype, pktlen);
1217 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1220 argint = va_arg(ap2, int);
1221 PUT_32BIT(p, argint);
1225 argchar = va_arg(ap2, unsigned char);
1230 argp = va_arg(ap2, unsigned char *);
1231 arglen = va_arg(ap2, int);
1232 memcpy(p, argp, arglen);
1236 argp = va_arg(ap2, unsigned char *);
1237 arglen = strlen(argp);
1238 PUT_32BIT(p, arglen);
1239 memcpy(p + 4, argp, arglen);
1243 bn = va_arg(ap2, Bignum);
1244 p += ssh1_write_bignum(p, bn);
1250 static void send_packet(int pkttype, ...)
1253 va_start(ap1, pkttype);
1254 va_start(ap2, pkttype);
1255 construct_packet(pkttype, ap1, ap2);
1259 static void defer_packet(int pkttype, ...)
1262 va_start(ap1, pkttype);
1263 va_start(ap2, pkttype);
1264 construct_packet(pkttype, ap1, ap2);
1268 static int ssh_versioncmp(char *a, char *b)
1271 unsigned long av, bv;
1273 av = strtoul(a, &ae, 10);
1274 bv = strtoul(b, &be, 10);
1276 return (av < bv ? -1 : +1);
1281 av = strtoul(ae, &ae, 10);
1282 bv = strtoul(be, &be, 10);
1284 return (av < bv ? -1 : +1);
1290 * Utility routines for putting an SSH-protocol `string' and
1291 * `uint32' into a SHA state.
1294 static void sha_string(SHA_State * s, void *str, int len)
1296 unsigned char lenblk[4];
1297 PUT_32BIT(lenblk, len);
1298 SHA_Bytes(s, lenblk, 4);
1299 SHA_Bytes(s, str, len);
1302 static void sha_uint32(SHA_State * s, unsigned i)
1304 unsigned char intblk[4];
1305 PUT_32BIT(intblk, i);
1306 SHA_Bytes(s, intblk, 4);
1310 * SSH2 packet construction functions.
1312 static void ssh2_pkt_ensure(int length)
1314 if (pktout.maxlen < length) {
1315 pktout.maxlen = length + 256;
1318 NULL ? smalloc(pktout.maxlen +
1319 APIEXTRA) : srealloc(pktout.data,
1323 fatalbox("Out of memory");
1326 static void ssh2_pkt_adddata(void *data, int len)
1328 pktout.length += len;
1329 ssh2_pkt_ensure(pktout.length);
1330 memcpy(pktout.data + pktout.length - len, data, len);
1332 static void ssh2_pkt_addbyte(unsigned char byte)
1334 ssh2_pkt_adddata(&byte, 1);
1336 static void ssh2_pkt_init(int pkt_type)
1339 ssh2_pkt_addbyte((unsigned char) pkt_type);
1341 static void ssh2_pkt_addbool(unsigned char value)
1343 ssh2_pkt_adddata(&value, 1);
1345 static void ssh2_pkt_adduint32(unsigned long value)
1348 PUT_32BIT(x, value);
1349 ssh2_pkt_adddata(x, 4);
1351 static void ssh2_pkt_addstring_start(void)
1353 ssh2_pkt_adduint32(0);
1354 pktout.savedpos = pktout.length;
1356 static void ssh2_pkt_addstring_str(char *data)
1358 ssh2_pkt_adddata(data, strlen(data));
1359 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1360 pktout.length - pktout.savedpos);
1362 static void ssh2_pkt_addstring_data(char *data, int len)
1364 ssh2_pkt_adddata(data, len);
1365 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1366 pktout.length - pktout.savedpos);
1368 static void ssh2_pkt_addstring(char *data)
1370 ssh2_pkt_addstring_start();
1371 ssh2_pkt_addstring_str(data);
1373 static char *ssh2_mpint_fmt(Bignum b, int *len)
1376 int i, n = (bignum_bitcount(b) + 7) / 8;
1379 fatalbox("out of memory");
1381 for (i = 1; i <= n; i++)
1382 p[i] = bignum_byte(b, n - i);
1384 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1386 memmove(p, p + i, n + 1 - i);
1390 static void ssh2_pkt_addmp(Bignum b)
1394 p = ssh2_mpint_fmt(b, &len);
1395 ssh2_pkt_addstring_start();
1396 ssh2_pkt_addstring_data(p, len);
1401 * Construct an SSH2 final-form packet: compress it, encrypt it,
1402 * put the MAC on it. Final packet, ready to be sent, is stored in
1403 * pktout.data. Total length is returned.
1405 static int ssh2_pkt_construct(void)
1407 int cipherblk, maclen, padding, i;
1408 static unsigned long outgoing_sequence = 0;
1410 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1411 pktout.data + 6, pktout.length - 6);
1414 * Compress packet payload.
1417 unsigned char *newpayload;
1419 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1420 &newpayload, &newlen)) {
1422 ssh2_pkt_adddata(newpayload, newlen);
1428 * Add padding. At least four bytes, and must also bring total
1429 * length (minus MAC) up to a multiple of the block size.
1431 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1432 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1435 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1436 maclen = csmac ? csmac->len : 0;
1437 ssh2_pkt_ensure(pktout.length + padding + maclen);
1438 pktout.data[4] = padding;
1439 for (i = 0; i < padding; i++)
1440 pktout.data[pktout.length + i] = random_byte();
1441 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1443 csmac->generate(pktout.data, pktout.length + padding,
1445 outgoing_sequence++; /* whether or not we MACed */
1448 cscipher->encrypt(pktout.data, pktout.length + padding);
1450 /* Ready-to-send packet starts at pktout.data. We return length. */
1451 return pktout.length + padding + maclen;
1455 * Construct and send an SSH2 packet immediately.
1457 static void ssh2_pkt_send(void)
1461 len = ssh2_pkt_construct();
1462 backlog = sk_write(s, pktout.data, len);
1463 if (backlog > SSH_MAX_BACKLOG)
1464 ssh_throttle_all(1, backlog);
1468 * Construct an SSH2 packet and add it to a deferred data block.
1469 * Useful for sending multiple packets in a single sk_write() call,
1470 * to prevent a traffic-analysing listener from being able to work
1471 * out the length of any particular packet (such as the password
1474 * Note that because SSH2 sequence-numbers its packets, this can
1475 * NOT be used as an m4-style `defer' allowing packets to be
1476 * constructed in one order and sent in another.
1478 static void ssh2_pkt_defer(void)
1480 int len = ssh2_pkt_construct();
1481 if (deferred_len + len > deferred_size) {
1482 deferred_size = deferred_len + len + 128;
1483 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1485 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1486 deferred_len += len;
1490 * Send the whole deferred data block constructed by
1491 * ssh2_pkt_defer() or SSH1's defer_packet().
1493 static void ssh_pkt_defersend(void)
1496 backlog = sk_write(s, deferred_send_data, deferred_len);
1497 deferred_len = deferred_size = 0;
1498 sfree(deferred_send_data);
1499 deferred_send_data = NULL;
1500 if (backlog > SSH_MAX_BACKLOG)
1501 ssh_throttle_all(1, backlog);
1505 void bndebug(char *string, Bignum b)
1509 p = ssh2_mpint_fmt(b, &len);
1510 debug(("%s", string));
1511 for (i = 0; i < len; i++)
1512 debug((" %02x", p[i]));
1518 static void sha_mpint(SHA_State * s, Bignum b)
1522 p = ssh2_mpint_fmt(b, &len);
1523 sha_string(s, p, len);
1528 * SSH2 packet decode functions.
1530 static unsigned long ssh2_pkt_getuint32(void)
1532 unsigned long value;
1533 if (pktin.length - pktin.savedpos < 4)
1534 return 0; /* arrgh, no way to decline (FIXME?) */
1535 value = GET_32BIT(pktin.data + pktin.savedpos);
1536 pktin.savedpos += 4;
1539 static int ssh2_pkt_getbool(void)
1541 unsigned long value;
1542 if (pktin.length - pktin.savedpos < 1)
1543 return 0; /* arrgh, no way to decline (FIXME?) */
1544 value = pktin.data[pktin.savedpos] != 0;
1548 static void ssh2_pkt_getstring(char **p, int *length)
1552 if (pktin.length - pktin.savedpos < 4)
1554 *length = GET_32BIT(pktin.data + pktin.savedpos);
1555 pktin.savedpos += 4;
1556 if (pktin.length - pktin.savedpos < *length)
1558 *p = pktin.data + pktin.savedpos;
1559 pktin.savedpos += *length;
1561 static Bignum ssh2_pkt_getmp(void)
1567 ssh2_pkt_getstring(&p, &length);
1571 bombout(("internal error: Can't handle negative mpints"));
1574 b = bignum_from_bytes(p, length);
1579 * Helper function to add an SSH2 signature blob to a packet.
1580 * Expects to be shown the public key blob as well as the signature
1581 * blob. Normally works just like ssh2_pkt_addstring, but will
1582 * fiddle with the signature packet if necessary for
1583 * BUG_SSH2_RSA_PADDING.
1585 static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len,
1586 void *sigblob_v, int sigblob_len)
1588 unsigned char *pkblob = (unsigned char *)pkblob_v;
1589 unsigned char *sigblob = (unsigned char *)sigblob_v;
1591 /* dmemdump(pkblob, pkblob_len); */
1592 /* dmemdump(sigblob, sigblob_len); */
1595 * See if this is in fact an ssh-rsa signature and a buggy
1596 * server; otherwise we can just do this the easy way.
1598 if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) &&
1599 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1600 int pos, len, siglen;
1603 * Find the byte length of the modulus.
1606 pos = 4+7; /* skip over "ssh-rsa" */
1607 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1608 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1609 pos += 4; /* find modulus itself */
1610 while (len > 0 && pkblob[pos] == 0)
1612 /* debug(("modulus length is %d\n", len)); */
1615 * Now find the signature integer.
1617 pos = 4+7; /* skip over "ssh-rsa" */
1618 siglen = GET_32BIT(sigblob+pos);
1619 /* debug(("signature length is %d\n", siglen)); */
1621 if (len != siglen) {
1622 unsigned char newlen[4];
1623 ssh2_pkt_addstring_start();
1624 ssh2_pkt_addstring_data(sigblob, pos);
1625 /* dmemdump(sigblob, pos); */
1626 pos += 4; /* point to start of actual sig */
1627 PUT_32BIT(newlen, len);
1628 ssh2_pkt_addstring_data(newlen, 4);
1629 /* dmemdump(newlen, 4); */
1631 while (len-- > siglen) {
1632 ssh2_pkt_addstring_data(newlen, 1);
1633 /* dmemdump(newlen, 1); */
1635 ssh2_pkt_addstring_data(sigblob+pos, siglen);
1636 /* dmemdump(sigblob+pos, siglen); */
1640 /* Otherwise fall through and do it the easy way. */
1643 ssh2_pkt_addstring_start();
1644 ssh2_pkt_addstring_data(sigblob, sigblob_len);
1648 * Examine the remote side's version string and compare it against
1649 * a list of known buggy implementations.
1651 static void ssh_detect_bugs(char *vstring)
1653 char *imp; /* pointer to implementation part */
1655 imp += strcspn(imp, "-");
1657 imp += strcspn(imp, "-");
1660 ssh_remote_bugs = 0;
1662 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1663 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1664 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
1666 * These versions don't support SSH1_MSG_IGNORE, so we have
1667 * to use a different defence against password length
1670 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1671 logevent("We believe remote version has SSH1 ignore bug");
1674 if (!strcmp(imp, "Cisco-1.25")) {
1676 * These versions need a plain password sent; they can't
1677 * handle having a null and a random length of data after
1680 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1681 logevent("We believe remote version needs a plain SSH1 password");
1684 if (!strcmp(imp, "Cisco-1.25")) {
1686 * These versions apparently have no clue whatever about
1687 * RSA authentication and will panic and die if they see
1688 * an AUTH_RSA message.
1690 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1691 logevent("We believe remote version can't handle RSA authentication");
1694 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1695 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1696 !strncmp(imp, "2.1 ", 4)) {
1698 * These versions have the HMAC bug.
1700 ssh_remote_bugs |= BUG_SSH2_HMAC;
1701 logevent("We believe remote version has SSH2 HMAC bug");
1704 if ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1705 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')) {
1707 * These versions have the SSH2 RSA padding bug.
1709 ssh_remote_bugs |= BUG_SSH2_RSA_PADDING;
1710 logevent("We believe remote version has SSH2 RSA padding bug");
1714 static int do_ssh_init(unsigned char c)
1717 static char version[10];
1718 static char *vstring;
1719 static int vstrsize;
1722 static int proto1, proto2;
1726 /* Search for the string "SSH-" in the input. */
1729 static const int transS[] = { 1, 2, 2, 1 };
1730 static const int transH[] = { 0, 0, 3, 0 };
1731 static const int transminus[] = { 0, 0, 0, -1 };
1742 crReturn(1); /* get another character */
1746 vstring = smalloc(vstrsize);
1747 strcpy(vstring, "SSH-");
1751 crReturn(1); /* get another char */
1752 if (vslen >= vstrsize - 1) {
1754 vstring = srealloc(vstring, vstrsize);
1756 vstring[vslen++] = c;
1761 } else if (i < sizeof(version) - 1)
1763 } else if (c == '\n')
1767 ssh_agentfwd_enabled = FALSE;
1768 rdpkt2_state.incoming_sequence = 0;
1771 vlog = smalloc(20 + vslen);
1772 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
1773 sprintf(vlog, "Server version: %s", vstring);
1775 ssh_detect_bugs(vstring);
1779 * Decide which SSH protocol version to support.
1782 /* Anything strictly below "2.0" means protocol 1 is supported. */
1783 proto1 = ssh_versioncmp(version, "2.0") < 0;
1784 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1785 proto2 = ssh_versioncmp(version, "1.99") >= 0;
1787 if (cfg.sshprot == 0 && !proto1) {
1788 bombout(("SSH protocol version 1 required by user but not provided by server"));
1791 if (cfg.sshprot == 3 && !proto2) {
1792 bombout(("SSH protocol version 2 required by user but not provided by server"));
1796 if (proto2 && (cfg.sshprot >= 2 || !proto1)) {
1800 char verstring[80], vlog[100];
1801 sprintf(verstring, "SSH-2.0-%s", sshver);
1802 SHA_Init(&exhashbase);
1804 * Hash our version string and their version string.
1806 sha_string(&exhashbase, verstring, strlen(verstring));
1807 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1808 sprintf(vlog, "We claim version: %s", verstring);
1810 strcat(verstring, "\n");
1811 logevent("Using SSH protocol version 2");
1812 sk_write(s, verstring, strlen(verstring));
1813 ssh_protocol = ssh2_protocol;
1815 s_rdpkt = ssh2_rdpkt;
1820 char verstring[80], vlog[100];
1821 sprintf(verstring, "SSH-%s-%s",
1822 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1824 sprintf(vlog, "We claim version: %s", verstring);
1826 strcat(verstring, "\n");
1828 logevent("Using SSH protocol version 1");
1829 sk_write(s, verstring, strlen(verstring));
1830 ssh_protocol = ssh1_protocol;
1832 s_rdpkt = ssh1_rdpkt;
1834 ssh_state = SSH_STATE_BEFORE_SIZE;
1841 static void ssh_gotdata(unsigned char *data, int datalen)
1846 * To begin with, feed the characters one by one to the
1847 * protocol initialisation / selection function do_ssh_init().
1848 * When that returns 0, we're done with the initial greeting
1849 * exchange and can move on to packet discipline.
1854 crReturnV; /* more data please */
1855 ret = do_ssh_init(*data);
1863 * We emerge from that loop when the initial negotiation is
1864 * over and we have selected an s_rdpkt function. Now pass
1865 * everything to s_rdpkt, and then pass the resulting packets
1866 * to the proper protocol handler.
1871 while (datalen > 0) {
1872 if (s_rdpkt(&data, &datalen) == 0) {
1873 if (ssh_state == SSH_STATE_CLOSED) {
1876 ssh_protocol(NULL, 0, 1);
1877 if (ssh_state == SSH_STATE_CLOSED) {
1887 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1890 ssh_state = SSH_STATE_CLOSED;
1896 /* A socket error has occurred. */
1897 logevent(error_msg);
1898 connection_fatal(error_msg);
1900 /* Otherwise, the remote side closed the connection normally. */
1905 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1907 ssh_gotdata(data, len);
1908 if (ssh_state == SSH_STATE_CLOSED) {
1918 static void ssh_sent(Plug plug, int bufsize)
1921 * If the send backlog on the SSH socket itself clears, we
1922 * should unthrottle the whole world if it was throttled.
1924 if (bufsize < SSH_MAX_BACKLOG)
1925 ssh_throttle_all(0, bufsize);
1929 * Connect to specified host and port.
1930 * Returns an error message, or NULL on success.
1931 * Also places the canonical host name into `realhost'. It must be
1932 * freed by the caller.
1934 static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
1936 static struct plug_function_table fn_table = {
1941 }, *fn_table_ptr = &fn_table;
1950 savedhost = smalloc(1 + strlen(host));
1952 fatalbox("Out of memory");
1953 strcpy(savedhost, host);
1956 port = 22; /* default ssh port */
1971 sprintf(buf, "Looking up host \"%.170s\"", host);
1974 addr = sk_namelookup(host, realhost);
1975 if ((err = sk_addr_error(addr)))
1979 *realhost = strdup(FWhost);
1986 char buf[200], addrbuf[100];
1987 sk_getaddr(addr, addrbuf, 100);
1988 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1991 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
1992 if ((err = sk_socket_error(s))) {
1998 sk_write(s, "connect ", 8);
1999 sk_write(s, FWhost, strlen(FWhost));
2002 sprintf(buf, " %d\n", FWport);
2003 sk_write(s, buf, strlen(buf));
2011 * Throttle or unthrottle the SSH connection.
2013 static void ssh1_throttle(int adjust)
2015 int old_count = ssh1_throttle_count;
2016 ssh1_throttle_count += adjust;
2017 assert(ssh1_throttle_count >= 0);
2018 if (ssh1_throttle_count && !old_count) {
2019 sk_set_frozen(s, 1);
2020 } else if (!ssh1_throttle_count && old_count) {
2021 sk_set_frozen(s, 0);
2026 * Throttle or unthrottle _all_ local data streams (for when sends
2027 * on the SSH connection itself back up).
2029 static void ssh_throttle_all(int enable, int bufsize)
2032 struct ssh_channel *c;
2034 if (enable == ssh_throttled_all)
2036 ssh_throttled_all = enable;
2037 ssh_overall_bufsize = bufsize;
2040 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
2042 case CHAN_MAINSESSION:
2044 * This is treated separately, outside the switch.
2048 x11_override_throttle(c->u.x11.s, enable);
2051 /* Agent channels require no buffer management. */
2054 pfd_override_throttle(c->u.x11.s, enable);
2061 * Username and password input, abstracted off into reusable
2062 * routines (hopefully even reusable between SSH1 and SSH2!).
2064 static char *ssh_userpass_input_buffer;
2065 static int ssh_userpass_input_buflen;
2066 static int ssh_userpass_input_bufpos;
2067 static int ssh_userpass_input_echo;
2069 /* Set up a username or password input loop on a given buffer. */
2070 void setup_userpass_input(char *buffer, int buflen, int echo)
2072 ssh_userpass_input_buffer = buffer;
2073 ssh_userpass_input_buflen = buflen;
2074 ssh_userpass_input_bufpos = 0;
2075 ssh_userpass_input_echo = echo;
2079 * Process some terminal data in the course of username/password
2080 * input. Returns >0 for success (line of input returned in
2081 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2082 * for inconclusive (keep waiting for more input please).
2084 int process_userpass_input(unsigned char *in, int inlen)
2089 switch (c = *in++) {
2092 ssh_userpass_input_buffer[ssh_userpass_input_bufpos] = 0;
2093 ssh_userpass_input_buffer[ssh_userpass_input_buflen-1] = 0;
2098 if (ssh_userpass_input_bufpos > 0) {
2099 if (ssh_userpass_input_echo)
2100 c_write_str("\b \b");
2101 ssh_userpass_input_bufpos--;
2106 while (ssh_userpass_input_bufpos > 0) {
2107 if (ssh_userpass_input_echo)
2108 c_write_str("\b \b");
2109 ssh_userpass_input_bufpos--;
2117 if (((c >= ' ' && c <= '~') ||
2118 ((unsigned char) c >= 160))
2119 && ssh_userpass_input_bufpos < ssh_userpass_input_buflen-1) {
2120 ssh_userpass_input_buffer[ssh_userpass_input_bufpos++] = c;
2121 if (ssh_userpass_input_echo)
2131 * Handle the key exchange and user authentication phases.
2133 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
2137 static unsigned char *rsabuf, *keystr1, *keystr2;
2138 unsigned char cookie[8];
2139 struct RSAKey servkey, hostkey;
2140 struct MD5Context md5c;
2141 static unsigned long supported_ciphers_mask, supported_auths_mask;
2142 static int tried_publickey, tried_agent;
2143 static int tis_auth_refused, ccard_auth_refused;
2144 static unsigned char session_id[16];
2145 static int cipher_type;
2146 static char username[100];
2147 static void *publickey_blob;
2148 int publickey_bloblen;
2155 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2156 bombout(("Public key packet not received"));
2160 logevent("Received public keys");
2162 memcpy(cookie, pktin.body, 8);
2164 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2165 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
2168 * Log the host key fingerprint.
2172 logevent("Host key fingerprint is:");
2173 strcpy(logmsg, " ");
2174 hostkey.comment = NULL;
2175 rsa_fingerprint(logmsg + strlen(logmsg),
2176 sizeof(logmsg) - strlen(logmsg), &hostkey);
2180 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2181 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2182 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
2184 ssh1_local_protoflags =
2185 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2186 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2189 MD5Update(&md5c, keystr2, hostkey.bytes);
2190 MD5Update(&md5c, keystr1, servkey.bytes);
2191 MD5Update(&md5c, pktin.body, 8);
2192 MD5Final(session_id, &md5c);
2194 for (i = 0; i < 32; i++)
2195 session_key[i] = random_byte();
2197 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2199 rsabuf = smalloc(len);
2201 fatalbox("Out of memory");
2204 * Verify the host key.
2208 * First format the key into a string.
2210 int len = rsastr_len(&hostkey);
2211 char fingerprint[100];
2212 char *keystr = smalloc(len);
2214 fatalbox("Out of memory");
2215 rsastr_fmt(keystr, &hostkey);
2216 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2217 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2222 for (i = 0; i < 32; i++) {
2223 rsabuf[i] = session_key[i];
2225 rsabuf[i] ^= session_id[i];
2228 if (hostkey.bytes > servkey.bytes) {
2229 rsaencrypt(rsabuf, 32, &servkey);
2230 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2232 rsaencrypt(rsabuf, 32, &hostkey);
2233 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2236 logevent("Encrypted session key");
2239 int cipher_chosen = 0, warn = 0;
2240 char *cipher_string = NULL;
2241 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2242 int next_cipher = cfg.ssh_cipherlist[i];
2243 if (next_cipher == CIPHER_WARN) {
2244 /* If/when we choose a cipher, warn about it */
2246 } else if (next_cipher == CIPHER_AES) {
2247 /* XXX Probably don't need to mention this. */
2248 logevent("AES not supported in SSH1, skipping");
2250 switch (next_cipher) {
2251 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2252 cipher_string = "3DES"; break;
2253 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2254 cipher_string = "Blowfish"; break;
2255 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2256 cipher_string = "single-DES"; break;
2258 if (supported_ciphers_mask & (1 << cipher_type))
2262 if (!cipher_chosen) {
2263 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2264 bombout(("Server violates SSH 1 protocol by not "
2265 "supporting 3DES encryption"));
2267 /* shouldn't happen */
2268 bombout(("No supported ciphers found"));
2272 /* Warn about chosen cipher if necessary. */
2274 askcipher(cipher_string, 0);
2277 switch (cipher_type) {
2278 case SSH_CIPHER_3DES:
2279 logevent("Using 3DES encryption");
2281 case SSH_CIPHER_DES:
2282 logevent("Using single-DES encryption");
2284 case SSH_CIPHER_BLOWFISH:
2285 logevent("Using Blowfish encryption");
2289 send_packet(SSH1_CMSG_SESSION_KEY,
2290 PKT_CHAR, cipher_type,
2291 PKT_DATA, cookie, 8,
2292 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2293 PKT_DATA, rsabuf, len,
2294 PKT_INT, ssh1_local_protoflags, PKT_END);
2296 logevent("Trying to enable encryption...");
2300 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2301 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
2302 cipher->sesskey(session_key);
2306 if (pktin.type != SSH1_SMSG_SUCCESS) {
2307 bombout(("Encryption not successfully enabled"));
2311 logevent("Successfully started encryption");
2315 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2316 if (ssh_get_line && !ssh_getline_pw_only) {
2317 if (!ssh_get_line("login as: ",
2318 username, sizeof(username), FALSE)) {
2320 * get_line failed to get a username.
2323 logevent("No username provided. Abandoning session.");
2324 ssh_state = SSH_STATE_CLOSED;
2329 c_write_str("login as: ");
2332 setup_userpass_input(username, sizeof(username), 1);
2334 crWaitUntil(!ispkt);
2335 ret = process_userpass_input(in, inlen);
2339 c_write_str("\r\n");
2342 strncpy(username, cfg.username, 99);
2343 username[99] = '\0';
2346 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2348 char userlog[22 + sizeof(username)];
2349 sprintf(userlog, "Sent username \"%s\"", username);
2351 if (flags & FLAG_INTERACTIVE &&
2352 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2353 strcat(userlog, "\r\n");
2354 c_write_str(userlog);
2361 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2362 /* We must not attempt PK auth. Pretend we've already tried it. */
2363 tried_publickey = tried_agent = 1;
2365 tried_publickey = tried_agent = 0;
2367 tis_auth_refused = ccard_auth_refused = 0;
2368 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2370 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2371 publickey_blob = NULL;
2373 publickey_blob = NULL;
2375 while (pktin.type == SSH1_SMSG_FAILURE) {
2376 static char password[100];
2377 static char prompt[200];
2380 static int pwpkt_type;
2381 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2383 if (agent_exists() && !tried_agent) {
2385 * Attempt RSA authentication using Pageant.
2387 static unsigned char request[5], *response, *p;
2388 static int responselen;
2389 static int i, nkeys;
2390 static int authed = FALSE;
2394 logevent("Pageant is running. Requesting keys.");
2396 /* Request the keys held by the agent. */
2397 PUT_32BIT(request, 1);
2398 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2399 agent_query(request, 5, &r, &responselen);
2400 response = (unsigned char *) r;
2401 if (response && responselen >= 5 &&
2402 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2404 nkeys = GET_32BIT(p);
2408 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2411 for (i = 0; i < nkeys; i++) {
2412 static struct RSAKey key;
2413 static Bignum challenge;
2414 static char *commentp;
2415 static int commentlen;
2419 sprintf(buf, "Trying Pageant key #%d", i);
2422 if (publickey_blob &&
2423 !memcmp(p, publickey_blob, publickey_bloblen)) {
2424 logevent("This key matches configured key file");
2425 tried_publickey = 1;
2428 p += ssh1_read_bignum(p, &key.exponent);
2429 p += ssh1_read_bignum(p, &key.modulus);
2430 commentlen = GET_32BIT(p);
2434 send_packet(SSH1_CMSG_AUTH_RSA,
2435 PKT_BIGNUM, key.modulus, PKT_END);
2437 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2438 logevent("Key refused");
2441 logevent("Received RSA challenge");
2442 ssh1_read_bignum(pktin.body, &challenge);
2444 char *agentreq, *q, *ret;
2447 len = 1 + 4; /* message type, bit count */
2448 len += ssh1_bignum_length(key.exponent);
2449 len += ssh1_bignum_length(key.modulus);
2450 len += ssh1_bignum_length(challenge);
2451 len += 16; /* session id */
2452 len += 4; /* response format */
2453 agentreq = smalloc(4 + len);
2454 PUT_32BIT(agentreq, len);
2456 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2457 PUT_32BIT(q, bignum_bitcount(key.modulus));
2459 q += ssh1_write_bignum(q, key.exponent);
2460 q += ssh1_write_bignum(q, key.modulus);
2461 q += ssh1_write_bignum(q, challenge);
2462 memcpy(q, session_id, 16);
2464 PUT_32BIT(q, 1); /* response format */
2465 agent_query(agentreq, len + 4, &vret, &retlen);
2469 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2470 logevent("Sending Pageant's response");
2471 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2472 PKT_DATA, ret + 5, 16,
2476 if (pktin.type == SSH1_SMSG_SUCCESS) {
2478 ("Pageant's response accepted");
2479 if (flags & FLAG_VERBOSE) {
2481 ("Authenticated using RSA key \"");
2482 c_write(commentp, commentlen);
2483 c_write_str("\" from agent\r\n");
2488 ("Pageant's response not accepted");
2491 ("Pageant failed to answer challenge");
2495 logevent("No reply received from Pageant");
2498 freebn(key.exponent);
2499 freebn(key.modulus);
2508 if (*cfg.keyfile && !tried_publickey)
2509 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2511 if (cfg.try_tis_auth &&
2512 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2513 !tis_auth_refused) {
2514 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2515 logevent("Requested TIS authentication");
2516 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2518 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2519 logevent("TIS authentication declined");
2520 if (flags & FLAG_INTERACTIVE)
2521 c_write_str("TIS authentication refused.\r\n");
2522 tis_auth_refused = 1;
2525 int challengelen = ((pktin.body[0] << 24) |
2526 (pktin.body[1] << 16) |
2527 (pktin.body[2] << 8) |
2529 logevent("Received TIS challenge");
2530 if (challengelen > sizeof(prompt) - 1)
2531 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2532 memcpy(prompt, pktin.body + 4, challengelen);
2533 /* Prompt heuristic comes from OpenSSH */
2534 strncpy(prompt + challengelen,
2535 memchr(prompt, '\n', challengelen) ?
2536 "": "\r\nResponse: ",
2537 (sizeof prompt) - challengelen);
2538 prompt[(sizeof prompt) - 1] = '\0';
2541 if (cfg.try_tis_auth &&
2542 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2543 !ccard_auth_refused) {
2544 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2545 logevent("Requested CryptoCard authentication");
2546 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2548 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2549 logevent("CryptoCard authentication declined");
2550 c_write_str("CryptoCard authentication refused.\r\n");
2551 ccard_auth_refused = 1;
2554 int challengelen = ((pktin.body[0] << 24) |
2555 (pktin.body[1] << 16) |
2556 (pktin.body[2] << 8) |
2558 logevent("Received CryptoCard challenge");
2559 if (challengelen > sizeof(prompt) - 1)
2560 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2561 memcpy(prompt, pktin.body + 4, challengelen);
2562 strncpy(prompt + challengelen,
2563 memchr(prompt, '\n', challengelen) ?
2564 "" : "\r\nResponse: ",
2565 sizeof(prompt) - challengelen);
2566 prompt[sizeof(prompt) - 1] = '\0';
2569 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2570 sprintf(prompt, "%.90s@%.90s's password: ",
2571 username, savedhost);
2573 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2574 char *comment = NULL;
2577 if (flags & FLAG_VERBOSE)
2578 c_write_str("Trying public key authentication.\r\n");
2579 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2581 type = key_type(cfg.keyfile);
2582 if (type != SSH_KEYTYPE_SSH1) {
2583 sprintf(msgbuf, "Key is of wrong type (%s)",
2584 key_type_to_str(type));
2586 c_write_str(msgbuf);
2587 c_write_str("\r\n");
2588 tried_publickey = 1;
2591 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2592 if (flags & FLAG_VERBOSE)
2593 c_write_str("No passphrase required.\r\n");
2596 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2601 * Show password prompt, having first obtained it via a TIS
2602 * or CryptoCard exchange if we're doing TIS or CryptoCard
2606 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2608 * get_line failed to get a password (for example
2609 * because one was supplied on the command line
2610 * which has already failed to work). Terminate.
2612 send_packet(SSH1_MSG_DISCONNECT,
2613 PKT_STR, "No more passwords available to try",
2615 logevent("Unable to authenticate");
2616 connection_fatal("Unable to authenticate");
2617 ssh_state = SSH_STATE_CLOSED;
2621 /* Prompt may have come from server. We've munged it a bit, so
2622 * we know it to be zero-terminated at least once. */
2624 c_write_untrusted(prompt, strlen(prompt));
2627 setup_userpass_input(password, sizeof(password), 0);
2629 crWaitUntil(!ispkt);
2630 ret = process_userpass_input(in, inlen);
2634 c_write_str("\r\n");
2638 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2640 * Try public key authentication with the specified
2643 static struct RSAKey pubkey;
2644 static Bignum challenge, response;
2646 static unsigned char buffer[32];
2648 tried_publickey = 1;
2649 i = loadrsakey(cfg.keyfile, &pubkey, password);
2651 c_write_str("Couldn't load private key from ");
2652 c_write_str(cfg.keyfile);
2653 c_write_str(".\r\n");
2654 continue; /* go and try password */
2657 c_write_str("Wrong passphrase.\r\n");
2658 tried_publickey = 0;
2659 continue; /* try again */
2663 * Send a public key attempt.
2665 send_packet(SSH1_CMSG_AUTH_RSA,
2666 PKT_BIGNUM, pubkey.modulus, PKT_END);
2669 if (pktin.type == SSH1_SMSG_FAILURE) {
2670 c_write_str("Server refused our public key.\r\n");
2671 continue; /* go and try password */
2673 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2674 bombout(("Bizarre response to offer of public key"));
2677 ssh1_read_bignum(pktin.body, &challenge);
2678 response = rsadecrypt(challenge, &pubkey);
2679 freebn(pubkey.private_exponent); /* burn the evidence */
2681 for (i = 0; i < 32; i++) {
2682 buffer[i] = bignum_byte(response, 31 - i);
2686 MD5Update(&md5c, buffer, 32);
2687 MD5Update(&md5c, session_id, 16);
2688 MD5Final(buffer, &md5c);
2690 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2691 PKT_DATA, buffer, 16, PKT_END);
2694 if (pktin.type == SSH1_SMSG_FAILURE) {
2695 if (flags & FLAG_VERBOSE)
2697 ("Failed to authenticate with our public key.\r\n");
2698 continue; /* go and try password */
2699 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2701 ("Bizarre response to RSA authentication response"));
2705 break; /* we're through! */
2707 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2709 * Defence against traffic analysis: we send a
2710 * whole bunch of packets containing strings of
2711 * different lengths. One of these strings is the
2712 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2713 * The others are all random data in
2714 * SSH1_MSG_IGNORE packets. This way a passive
2715 * listener can't tell which is the password, and
2716 * hence can't deduce the password length.
2718 * Anybody with a password length greater than 16
2719 * bytes is going to have enough entropy in their
2720 * password that a listener won't find it _that_
2721 * much help to know how long it is. So what we'll
2724 * - if password length < 16, we send 15 packets
2725 * containing string lengths 1 through 15
2727 * - otherwise, we let N be the nearest multiple
2728 * of 8 below the password length, and send 8
2729 * packets containing string lengths N through
2730 * N+7. This won't obscure the order of
2731 * magnitude of the password length, but it will
2732 * introduce a bit of extra uncertainty.
2734 * A few servers (the old 1.2.18 through 1.2.22)
2735 * can't deal with SSH1_MSG_IGNORE. For these
2736 * servers, we need an alternative defence. We make
2737 * use of the fact that the password is interpreted
2738 * as a C string: so we can append a NUL, then some
2741 * One server (a Cisco one) can deal with neither
2742 * SSH1_MSG_IGNORE _nor_ a padded password string.
2743 * For this server we are left with no defences
2744 * against password length sniffing.
2746 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2748 * The server can deal with SSH1_MSG_IGNORE, so
2749 * we can use the primary defence.
2751 int bottom, top, pwlen, i;
2754 pwlen = strlen(password);
2756 bottom = 0; /* zero length passwords are OK! :-) */
2759 bottom = pwlen & ~7;
2763 assert(pwlen >= bottom && pwlen <= top);
2765 randomstr = smalloc(top + 1);
2767 for (i = bottom; i <= top; i++) {
2769 defer_packet(pwpkt_type, PKT_STR, password,
2772 for (j = 0; j < i; j++) {
2774 randomstr[j] = random_byte();
2775 } while (randomstr[j] == '\0');
2777 randomstr[i] = '\0';
2778 defer_packet(SSH1_MSG_IGNORE,
2779 PKT_STR, randomstr, PKT_END);
2782 logevent("Sending password with camouflage packets");
2783 ssh_pkt_defersend();
2785 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2787 * The server can't deal with SSH1_MSG_IGNORE
2788 * but can deal with padded passwords, so we
2789 * can use the secondary defence.
2795 len = strlen(password);
2796 if (len < sizeof(string)) {
2798 strcpy(string, password);
2799 len++; /* cover the zero byte */
2800 while (len < sizeof(string)) {
2801 string[len++] = (char) random_byte();
2806 logevent("Sending length-padded password");
2807 send_packet(pwpkt_type, PKT_INT, len,
2808 PKT_DATA, s, len, PKT_END);
2811 * The server has _both_
2812 * BUG_CHOKES_ON_SSH1_IGNORE and
2813 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2814 * therefore nothing we can do.
2817 len = strlen(password);
2818 logevent("Sending unpadded password");
2819 send_packet(pwpkt_type, PKT_INT, len,
2820 PKT_DATA, password, len, PKT_END);
2823 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2826 logevent("Sent password");
2827 memset(password, 0, strlen(password));
2829 if (pktin.type == SSH1_SMSG_FAILURE) {
2830 if (flags & FLAG_VERBOSE)
2831 c_write_str("Access denied\r\n");
2832 logevent("Authentication refused");
2833 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2834 logevent("Received disconnect request");
2835 ssh_state = SSH_STATE_CLOSED;
2837 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2838 bombout(("Strange packet received, type %d", pktin.type));
2843 logevent("Authentication successful");
2848 void sshfwd_close(struct ssh_channel *c)
2850 if (c && !c->closes) {
2852 * If the channel's remoteid is -1, we have sent
2853 * CHANNEL_OPEN for this channel, but it hasn't even been
2854 * acknowledged by the server. So we must set a close flag
2855 * on it now, and then when the server acks the channel
2856 * open, we can close it then.
2858 if (((int)c->remoteid) != -1) {
2859 if (ssh_version == 1) {
2860 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2863 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2864 ssh2_pkt_adduint32(c->remoteid);
2869 if (c->type == CHAN_X11) {
2871 logevent("Forwarded X11 connection terminated");
2872 } else if (c->type == CHAN_SOCKDATA ||
2873 c->type == CHAN_SOCKDATA_DORMANT) {
2875 logevent("Forwarded port closed");
2880 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2882 if (ssh_version == 1) {
2883 send_packet(SSH1_MSG_CHANNEL_DATA,
2884 PKT_INT, c->remoteid,
2885 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2887 * In SSH1 we can return 0 here - implying that forwarded
2888 * connections are never individually throttled - because
2889 * the only circumstance that can cause throttling will be
2890 * the whole SSH connection backing up, in which case
2891 * _everything_ will be throttled as a whole.
2895 ssh2_add_channel_data(c, buf, len);
2896 return ssh2_try_send(c);
2900 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2902 if (ssh_version == 1) {
2903 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2904 c->v.v1.throttling = 0;
2908 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2912 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2918 while (!do_ssh1_login(in, inlen, ispkt)) {
2921 if (ssh_state == SSH_STATE_CLOSED)
2924 if (cfg.agentfwd && agent_exists()) {
2925 logevent("Requesting agent forwarding");
2926 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2930 if (pktin.type != SSH1_SMSG_SUCCESS
2931 && pktin.type != SSH1_SMSG_FAILURE) {
2932 bombout(("Protocol confusion"));
2934 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2935 logevent("Agent forwarding refused");
2937 logevent("Agent forwarding enabled");
2938 ssh_agentfwd_enabled = TRUE;
2942 if (cfg.x11_forward) {
2943 char proto[20], data[64];
2944 logevent("Requesting X11 forwarding");
2945 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2946 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2947 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2948 PKT_STR, proto, PKT_STR, data,
2949 PKT_INT, 0, PKT_END);
2951 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2952 PKT_STR, proto, PKT_STR, data, PKT_END);
2957 if (pktin.type != SSH1_SMSG_SUCCESS
2958 && pktin.type != SSH1_SMSG_FAILURE) {
2959 bombout(("Protocol confusion"));
2961 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2962 logevent("X11 forwarding refused");
2964 logevent("X11 forwarding enabled");
2965 ssh_X11_fwd_enabled = TRUE;
2973 int sport,dport,sserv,dserv;
2974 char sports[256], dports[256], host[256];
2978 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2979 /* Add port forwardings. */
2984 while (*e && *e != '\t')
2990 while (*e && *e != ':')
3000 dport = atoi(dports);
3004 se = getservbyname(dports, NULL);
3006 dport = ntohs(se->s_port);
3009 "Service lookup failed for destination port \"%s\"",
3014 sport = atoi(sports);
3018 se = getservbyname(sports, NULL);
3020 sport = ntohs(se->s_port);
3023 "Service lookup failed for source port \"%s\"",
3028 if (sport && dport) {
3030 pfd_addforward(host, dport, sport);
3031 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3032 " %s:%.*s%.*s%d%.*s",
3033 sserv ? strlen(sports) : 0, sports,
3034 sserv, "(", sport, sserv, ")",
3036 dserv ? strlen(dports) : 0, dports,
3037 dserv, "(", dport, dserv, ")");
3040 struct ssh_rportfwd *pf;
3041 pf = smalloc(sizeof(*pf));
3042 strcpy(pf->dhost, host);
3044 if (add234(ssh_rportfwds, pf) != pf) {
3046 "Duplicate remote port forwarding to %s:%d",
3051 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3052 " forward to %s:%.*s%.*s%d%.*s",
3053 sserv ? strlen(sports) : 0, sports,
3054 sserv, "(", sport, sserv, ")",
3056 dserv ? strlen(dports) : 0, dports,
3057 dserv, "(", dport, dserv, ")");
3059 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3067 if (pktin.type != SSH1_SMSG_SUCCESS
3068 && pktin.type != SSH1_SMSG_FAILURE) {
3069 bombout(("Protocol confusion"));
3071 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3072 c_write_str("Server refused port forwarding\r\n");
3073 ssh_editing = ssh_echoing = 1;
3075 logevent("Remote port forwarding enabled");
3083 send_packet(SSH1_CMSG_REQUEST_PTY,
3084 PKT_STR, cfg.termtype,
3085 PKT_INT, rows, PKT_INT, cols,
3086 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3087 ssh_state = SSH_STATE_INTERMED;
3091 if (pktin.type != SSH1_SMSG_SUCCESS
3092 && pktin.type != SSH1_SMSG_FAILURE) {
3093 bombout(("Protocol confusion"));
3095 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3096 c_write_str("Server refused to allocate pty\r\n");
3097 ssh_editing = ssh_echoing = 1;
3099 logevent("Allocated pty");
3101 ssh_editing = ssh_echoing = 1;
3104 if (cfg.compression) {
3105 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3109 if (pktin.type != SSH1_SMSG_SUCCESS
3110 && pktin.type != SSH1_SMSG_FAILURE) {
3111 bombout(("Protocol confusion"));
3113 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3114 c_write_str("Server refused to compress\r\n");
3116 logevent("Started compression");
3117 ssh1_compressing = TRUE;
3118 zlib_compress_init();
3119 zlib_decompress_init();
3123 * Start the shell or command.
3125 * Special case: if the first-choice command is an SSH2
3126 * subsystem (hence not usable here) and the second choice
3127 * exists, we fall straight back to that.
3130 char *cmd = cfg.remote_cmd_ptr;
3132 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3133 cmd = cfg.remote_cmd_ptr2;
3134 ssh_fallback_cmd = TRUE;
3137 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3139 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3140 logevent("Started session");
3143 ssh_state = SSH_STATE_SESSION;
3147 ssh_special(TS_EOF);
3149 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
3151 ssh_channels = newtree234(ssh_channelcmp);
3155 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
3156 pktin.type == SSH1_SMSG_STDERR_DATA) {
3157 long len = GET_32BIT(pktin.body);
3159 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3160 pktin.body + 4, len);
3161 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3162 ssh1_stdout_throttling = 1;
3165 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
3166 ssh_state = SSH_STATE_CLOSED;
3167 logevent("Received disconnect request");
3169 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3170 /* Remote side is trying to open a channel to talk to our
3171 * X-Server. Give them back a local channel number. */
3172 struct ssh_channel *c;
3174 logevent("Received X11 connect request");
3175 /* Refuse if X11 forwarding is disabled. */
3176 if (!ssh_X11_fwd_enabled) {
3177 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3178 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3179 logevent("Rejected X11 connect request");
3181 c = smalloc(sizeof(struct ssh_channel));
3183 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3184 logevent("opening X11 forward connection failed");
3186 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3187 PKT_INT, GET_32BIT(pktin.body),
3191 ("opening X11 forward connection succeeded");
3192 c->remoteid = GET_32BIT(pktin.body);
3193 c->localid = alloc_channel_id();
3195 c->v.v1.throttling = 0;
3196 c->type = CHAN_X11; /* identify channel type */
3197 add234(ssh_channels, c);
3198 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3199 PKT_INT, c->remoteid, PKT_INT,
3200 c->localid, PKT_END);
3201 logevent("Opened X11 forward channel");
3204 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3205 /* Remote side is trying to open a channel to talk to our
3206 * agent. Give them back a local channel number. */
3207 struct ssh_channel *c;
3209 /* Refuse if agent forwarding is disabled. */
3210 if (!ssh_agentfwd_enabled) {
3211 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3212 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3214 c = smalloc(sizeof(struct ssh_channel));
3215 c->remoteid = GET_32BIT(pktin.body);
3216 c->localid = alloc_channel_id();
3218 c->v.v1.throttling = 0;
3219 c->type = CHAN_AGENT; /* identify channel type */
3220 c->u.a.lensofar = 0;
3221 add234(ssh_channels, c);
3222 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3223 PKT_INT, c->remoteid, PKT_INT, c->localid,
3226 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3227 /* Remote side is trying to open a channel to talk to a
3228 * forwarded port. Give them back a local channel number. */
3229 struct ssh_channel *c;
3230 struct ssh_rportfwd pf;
3232 char host[256], buf[1024];
3234 c = smalloc(sizeof(struct ssh_channel));
3236 hostsize = GET_32BIT(pktin.body+4);
3237 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3238 if (h+1 < host+sizeof(host))
3243 port = GET_32BIT(p);
3245 strcpy(pf.dhost, host);
3248 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3249 sprintf(buf, "Rejected remote port open request for %s:%d",
3252 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3253 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3255 sprintf(buf, "Received remote port open request for %s:%d",
3258 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3261 sprintf(buf, "Port open failed: %s", e);
3264 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3265 PKT_INT, GET_32BIT(pktin.body),
3268 c->remoteid = GET_32BIT(pktin.body);
3269 c->localid = alloc_channel_id();
3271 c->v.v1.throttling = 0;
3272 c->type = CHAN_SOCKDATA; /* identify channel type */
3273 add234(ssh_channels, c);
3274 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3275 PKT_INT, c->remoteid, PKT_INT,
3276 c->localid, PKT_END);
3277 logevent("Forwarded port opened successfully");
3281 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3282 unsigned int remoteid = GET_32BIT(pktin.body);
3283 unsigned int localid = GET_32BIT(pktin.body+4);
3284 struct ssh_channel *c;
3286 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3287 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3288 c->remoteid = localid;
3289 c->type = CHAN_SOCKDATA;
3290 c->v.v1.throttling = 0;
3291 pfd_confirm(c->u.pfd.s);
3294 if (c && c->closes) {
3296 * We have a pending close on this channel,
3297 * which we decided on before the server acked
3298 * the channel open. So now we know the
3299 * remoteid, we can close it again.
3301 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3305 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3306 unsigned int remoteid = GET_32BIT(pktin.body);
3307 unsigned int localid = GET_32BIT(pktin.body+4);
3308 struct ssh_channel *c;
3310 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3311 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3312 logevent("Forwarded connection refused by server");
3313 pfd_close(c->u.pfd.s);
3314 del234(ssh_channels, c);
3318 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3319 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3320 /* Remote side closes a channel. */
3321 unsigned i = GET_32BIT(pktin.body);
3322 struct ssh_channel *c;
3323 c = find234(ssh_channels, &i, ssh_channelfind);
3327 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3328 if (!(c->closes & closetype))
3329 send_packet(pktin.type, PKT_INT, c->remoteid,
3331 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3332 logevent("Forwarded X11 connection terminated");
3333 assert(c->u.x11.s != NULL);
3334 x11_close(c->u.x11.s);
3337 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3338 logevent("Forwarded port closed");
3339 assert(c->u.pfd.s != NULL);
3340 pfd_close(c->u.pfd.s);
3343 c->closes |= closetype;
3344 if (c->closes == 3) {
3345 del234(ssh_channels, c);
3349 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3350 /* Data sent down one of our channels. */
3351 int i = GET_32BIT(pktin.body);
3352 int len = GET_32BIT(pktin.body + 4);
3353 unsigned char *p = pktin.body + 8;
3354 struct ssh_channel *c;
3355 c = find234(ssh_channels, &i, ssh_channelfind);
3360 bufsize = x11_send(c->u.x11.s, p, len);
3363 bufsize = pfd_send(c->u.pfd.s, p, len);
3366 /* Data for an agent message. Buffer it. */
3368 if (c->u.a.lensofar < 4) {
3369 int l = min(4 - c->u.a.lensofar, len);
3370 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3374 c->u.a.lensofar += l;
3376 if (c->u.a.lensofar == 4) {
3378 4 + GET_32BIT(c->u.a.msglen);
3379 c->u.a.message = smalloc(c->u.a.totallen);
3380 memcpy(c->u.a.message, c->u.a.msglen, 4);
3382 if (c->u.a.lensofar >= 4 && len > 0) {
3384 min(c->u.a.totallen - c->u.a.lensofar,
3386 memcpy(c->u.a.message + c->u.a.lensofar, p,
3390 c->u.a.lensofar += l;
3392 if (c->u.a.lensofar == c->u.a.totallen) {
3393 void *reply, *sentreply;
3395 agent_query(c->u.a.message,
3396 c->u.a.totallen, &reply,
3401 /* Fake SSH_AGENT_FAILURE. */
3402 sentreply = "\0\0\0\1\5";
3405 send_packet(SSH1_MSG_CHANNEL_DATA,
3406 PKT_INT, c->remoteid,
3408 PKT_DATA, sentreply, replylen,
3412 sfree(c->u.a.message);
3413 c->u.a.lensofar = 0;
3416 bufsize = 0; /* agent channels never back up */
3419 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3420 c->v.v1.throttling = 1;
3424 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3425 /* may be from EXEC_SHELL on some servers */
3426 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3427 /* may be from EXEC_SHELL on some servers
3428 * if no pty is available or in other odd cases. Ignore */
3429 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3431 ssh_exitcode = GET_32BIT(pktin.body);
3432 sprintf(buf, "Server sent command exit status %d",
3435 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3437 * In case `helpful' firewalls or proxies tack
3438 * extra human-readable text on the end of the
3439 * session which we might mistake for another
3440 * encrypted packet, we close the session once
3441 * we've sent EXIT_CONFIRMATION.
3443 ssh_state = SSH_STATE_CLOSED;
3446 bombout(("Strange packet received: type %d", pktin.type));
3451 int len = min(inlen, 512);
3452 send_packet(SSH1_CMSG_STDIN_DATA,
3453 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3464 * Utility routine for decoding comma-separated strings in KEXINIT.
3466 static int in_commasep_string(char *needle, char *haystack, int haylen)
3468 int needlen = strlen(needle);
3471 * Is it at the start of the string?
3473 if (haylen >= needlen && /* haystack is long enough */
3474 !memcmp(needle, haystack, needlen) && /* initial match */
3475 (haylen == needlen || haystack[needlen] == ',')
3476 /* either , or EOS follows */
3480 * If not, search for the next comma and resume after that.
3481 * If no comma found, terminate.
3483 while (haylen > 0 && *haystack != ',')
3484 haylen--, haystack++;
3487 haylen--, haystack++; /* skip over comma itself */
3492 * SSH2 key creation method.
3494 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3498 /* First 20 bytes. */
3501 SHA_Bytes(&s, H, 20);
3502 SHA_Bytes(&s, &chr, 1);
3503 SHA_Bytes(&s, sessid, 20);
3504 SHA_Final(&s, keyspace);
3505 /* Next 20 bytes. */
3508 SHA_Bytes(&s, H, 20);
3509 SHA_Bytes(&s, keyspace, 20);
3510 SHA_Final(&s, keyspace + 20);
3514 * Handle the SSH2 transport layer.
3516 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3518 static int i, j, len, nbits, pbits, warn;
3520 static Bignum p, g, e, f, K;
3521 static int kex_init_value, kex_reply_value;
3522 static const struct ssh_mac **maclist;
3524 static const struct ssh2_cipher *cscipher_tobe = NULL;
3525 static const struct ssh2_cipher *sccipher_tobe = NULL;
3526 static const struct ssh_mac *csmac_tobe = NULL;
3527 static const struct ssh_mac *scmac_tobe = NULL;
3528 static const struct ssh_compress *cscomp_tobe = NULL;
3529 static const struct ssh_compress *sccomp_tobe = NULL;
3530 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3531 static int hostkeylen, siglen;
3532 static void *hkey; /* actual host key */
3533 static unsigned char exchange_hash[20];
3534 static unsigned char keyspace[40];
3535 static int n_preferred_ciphers;
3536 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3537 static const struct ssh_compress *preferred_comp;
3538 static int cipherstr_started;
3539 static int first_kex;
3546 * Set up the preferred ciphers. (NULL => warn below here)
3548 n_preferred_ciphers = 0;
3549 for (i = 0; i < CIPHER_MAX; i++) {
3550 switch (cfg.ssh_cipherlist[i]) {
3551 case CIPHER_BLOWFISH:
3552 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3553 n_preferred_ciphers++;
3556 if (cfg.ssh2_des_cbc) {
3557 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3558 n_preferred_ciphers++;
3562 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3563 n_preferred_ciphers++;
3566 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3567 n_preferred_ciphers++;
3570 /* Flag for later. Don't bother if it's the last in
3572 if (i < CIPHER_MAX - 1) {
3573 preferred_ciphers[n_preferred_ciphers] = NULL;
3574 n_preferred_ciphers++;
3581 * Set up preferred compression.
3583 if (cfg.compression)
3584 preferred_comp = &ssh_zlib;
3586 preferred_comp = &ssh_comp_none;
3589 * Be prepared to work around the buggy MAC problem.
3591 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3592 maclist = buggymacs, nmacs = lenof(buggymacs);
3594 maclist = macs, nmacs = lenof(macs);
3598 * Construct and send our key exchange packet.
3600 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3601 for (i = 0; i < 16; i++)
3602 ssh2_pkt_addbyte((unsigned char) random_byte());
3603 /* List key exchange algorithms. */
3604 ssh2_pkt_addstring_start();
3605 for (i = 0; i < lenof(kex_algs); i++) {
3606 ssh2_pkt_addstring_str(kex_algs[i]->name);
3607 if (i < lenof(kex_algs) - 1)
3608 ssh2_pkt_addstring_str(",");
3610 /* List server host key algorithms. */
3611 ssh2_pkt_addstring_start();
3612 for (i = 0; i < lenof(hostkey_algs); i++) {
3613 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3614 if (i < lenof(hostkey_algs) - 1)
3615 ssh2_pkt_addstring_str(",");
3617 /* List client->server encryption algorithms. */
3618 ssh2_pkt_addstring_start();
3619 cipherstr_started = 0;
3620 for (i = 0; i < n_preferred_ciphers; i++) {
3621 const struct ssh2_ciphers *c = preferred_ciphers[i];
3622 if (!c) continue; /* warning flag */
3623 for (j = 0; j < c->nciphers; j++) {
3624 if (cipherstr_started)
3625 ssh2_pkt_addstring_str(",");
3626 ssh2_pkt_addstring_str(c->list[j]->name);
3627 cipherstr_started = 1;
3630 /* List server->client encryption algorithms. */
3631 ssh2_pkt_addstring_start();
3632 cipherstr_started = 0;
3633 for (i = 0; i < n_preferred_ciphers; i++) {
3634 const struct ssh2_ciphers *c = preferred_ciphers[i];
3635 if (!c) continue; /* warning flag */
3636 for (j = 0; j < c->nciphers; j++) {
3637 if (cipherstr_started)
3638 ssh2_pkt_addstring_str(",");
3639 ssh2_pkt_addstring_str(c->list[j]->name);
3640 cipherstr_started = 1;
3643 /* List client->server MAC algorithms. */
3644 ssh2_pkt_addstring_start();
3645 for (i = 0; i < nmacs; i++) {
3646 ssh2_pkt_addstring_str(maclist[i]->name);
3648 ssh2_pkt_addstring_str(",");
3650 /* List server->client MAC algorithms. */
3651 ssh2_pkt_addstring_start();
3652 for (i = 0; i < nmacs; i++) {
3653 ssh2_pkt_addstring_str(maclist[i]->name);
3655 ssh2_pkt_addstring_str(",");
3657 /* List client->server compression algorithms. */
3658 ssh2_pkt_addstring_start();
3659 for (i = 0; i < lenof(compressions) + 1; i++) {
3660 const struct ssh_compress *c =
3661 i == 0 ? preferred_comp : compressions[i - 1];
3662 ssh2_pkt_addstring_str(c->name);
3663 if (i < lenof(compressions))
3664 ssh2_pkt_addstring_str(",");
3666 /* List server->client compression algorithms. */
3667 ssh2_pkt_addstring_start();
3668 for (i = 0; i < lenof(compressions) + 1; i++) {
3669 const struct ssh_compress *c =
3670 i == 0 ? preferred_comp : compressions[i - 1];
3671 ssh2_pkt_addstring_str(c->name);
3672 if (i < lenof(compressions))
3673 ssh2_pkt_addstring_str(",");
3675 /* List client->server languages. Empty list. */
3676 ssh2_pkt_addstring_start();
3677 /* List server->client languages. Empty list. */
3678 ssh2_pkt_addstring_start();
3679 /* First KEX packet does _not_ follow, because we're not that brave. */
3680 ssh2_pkt_addbool(FALSE);
3682 ssh2_pkt_adduint32(0);
3684 exhash = exhashbase;
3685 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3691 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3694 * Now examine the other side's KEXINIT to see what we're up
3697 if (pktin.type != SSH2_MSG_KEXINIT) {
3698 bombout(("expected key exchange packet from server"));
3703 cscipher_tobe = NULL;
3704 sccipher_tobe = NULL;
3709 pktin.savedpos += 16; /* skip garbage cookie */
3710 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3711 for (i = 0; i < lenof(kex_algs); i++) {
3712 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3717 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3718 for (i = 0; i < lenof(hostkey_algs); i++) {
3719 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3720 hostkey = hostkey_algs[i];
3724 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3726 for (i = 0; i < n_preferred_ciphers; i++) {
3727 const struct ssh2_ciphers *c = preferred_ciphers[i];
3731 for (j = 0; j < c->nciphers; j++) {
3732 if (in_commasep_string(c->list[j]->name, str, len)) {
3733 cscipher_tobe = c->list[j];
3738 if (cscipher_tobe) {
3740 askcipher(cscipher_tobe->name, 1);
3744 if (!cscipher_tobe) {
3745 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3749 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3751 for (i = 0; i < n_preferred_ciphers; i++) {
3752 const struct ssh2_ciphers *c = preferred_ciphers[i];
3756 for (j = 0; j < c->nciphers; j++) {
3757 if (in_commasep_string(c->list[j]->name, str, len)) {
3758 sccipher_tobe = c->list[j];
3763 if (sccipher_tobe) {
3765 askcipher(sccipher_tobe->name, 2);
3769 if (!sccipher_tobe) {
3770 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3774 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3775 for (i = 0; i < nmacs; i++) {
3776 if (in_commasep_string(maclist[i]->name, str, len)) {
3777 csmac_tobe = maclist[i];
3781 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3782 for (i = 0; i < nmacs; i++) {
3783 if (in_commasep_string(maclist[i]->name, str, len)) {
3784 scmac_tobe = maclist[i];
3788 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3789 for (i = 0; i < lenof(compressions) + 1; i++) {
3790 const struct ssh_compress *c =
3791 i == 0 ? preferred_comp : compressions[i - 1];
3792 if (in_commasep_string(c->name, str, len)) {
3797 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3798 for (i = 0; i < lenof(compressions) + 1; i++) {
3799 const struct ssh_compress *c =
3800 i == 0 ? preferred_comp : compressions[i - 1];
3801 if (in_commasep_string(c->name, str, len)) {
3808 * Work out the number of bits of key we will need from the key
3809 * exchange. We start with the maximum key length of either
3815 csbits = cscipher_tobe->keylen;
3816 scbits = sccipher_tobe->keylen;
3817 nbits = (csbits > scbits ? csbits : scbits);
3819 /* The keys only have 160-bit entropy, since they're based on
3820 * a SHA-1 hash. So cap the key size at 160 bits. */
3825 * If we're doing Diffie-Hellman group exchange, start by
3826 * requesting a group.
3828 if (kex == &ssh_diffiehellman_gex) {
3829 logevent("Doing Diffie-Hellman group exchange");
3830 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
3832 * Work out how big a DH group we will need to allow that
3835 pbits = 512 << ((nbits - 1) / 64);
3836 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3837 ssh2_pkt_adduint32(pbits);
3841 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3842 bombout(("expected key exchange group packet from server"));
3845 p = ssh2_pkt_getmp();
3846 g = ssh2_pkt_getmp();
3847 dh_setup_group(p, g);
3848 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3849 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3851 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3853 kex_init_value = SSH2_MSG_KEXDH_INIT;
3854 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3857 logevent("Doing Diffie-Hellman key exchange");
3859 * Now generate and send e for Diffie-Hellman.
3861 e = dh_create_e(nbits * 2);
3862 ssh2_pkt_init(kex_init_value);
3867 if (pktin.type != kex_reply_value) {
3868 bombout(("expected key exchange reply packet from server"));
3871 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3872 f = ssh2_pkt_getmp();
3873 ssh2_pkt_getstring(&sigdata, &siglen);
3877 sha_string(&exhash, hostkeydata, hostkeylen);
3878 if (kex == &ssh_diffiehellman_gex) {
3879 sha_uint32(&exhash, pbits);
3880 sha_mpint(&exhash, p);
3881 sha_mpint(&exhash, g);
3883 sha_mpint(&exhash, e);
3884 sha_mpint(&exhash, f);
3885 sha_mpint(&exhash, K);
3886 SHA_Final(&exhash, exchange_hash);
3891 debug(("Exchange hash is:\n"));
3892 dmemdump(exchange_hash, 20);
3895 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3897 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3898 bombout(("Server's host key did not match the signature supplied"));
3903 * Authenticate remote host: verify host key. (We've already
3904 * checked the signature of the exchange hash.)
3906 keystr = hostkey->fmtkey(hkey);
3907 fingerprint = hostkey->fingerprint(hkey);
3908 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3909 keystr, fingerprint);
3910 if (first_kex) { /* don't bother logging this in rekeys */
3911 logevent("Host key fingerprint is:");
3912 logevent(fingerprint);
3916 hostkey->freekey(hkey);
3919 * Send SSH2_MSG_NEWKEYS.
3921 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3925 * Expect SSH2_MSG_NEWKEYS from server.
3928 if (pktin.type != SSH2_MSG_NEWKEYS) {
3929 bombout(("expected new-keys packet from server"));
3934 * Create and initialise session keys.
3936 cscipher = cscipher_tobe;
3937 sccipher = sccipher_tobe;
3940 cscomp = cscomp_tobe;
3941 sccomp = sccomp_tobe;
3942 cscomp->compress_init();
3943 sccomp->decompress_init();
3945 * Set IVs after keys. Here we use the exchange hash from the
3946 * _first_ key exchange.
3949 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3950 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3951 cscipher->setcskey(keyspace);
3952 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3953 sccipher->setsckey(keyspace);
3954 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3955 cscipher->setcsiv(keyspace);
3956 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3957 sccipher->setsciv(keyspace);
3958 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3959 csmac->setcskey(keyspace);
3960 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3961 scmac->setsckey(keyspace);
3964 * If this is the first key exchange phase, we must pass the
3965 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3966 * wants to see it but because it will need time to initialise
3967 * itself before it sees an actual packet. In subsequent key
3968 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3969 * it would only confuse the layer above.
3977 * Now we're encrypting. Begin returning 1 to the protocol main
3978 * function so that other things can run on top of the
3979 * transport. If we ever see a KEXINIT, we must go back to the
3982 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3985 logevent("Server initiated key re-exchange");
3986 goto begin_key_exchange;
3992 * Add data to an SSH2 channel output buffer.
3994 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3997 bufchain_add(&c->v.v2.outbuffer, buf, len);
4001 * Attempt to send data on an SSH2 channel.
4003 static int ssh2_try_send(struct ssh_channel *c)
4005 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4008 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4009 if ((unsigned)len > c->v.v2.remwindow)
4010 len = c->v.v2.remwindow;
4011 if ((unsigned)len > c->v.v2.remmaxpkt)
4012 len = c->v.v2.remmaxpkt;
4013 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
4014 ssh2_pkt_adduint32(c->remoteid);
4015 ssh2_pkt_addstring_start();
4016 ssh2_pkt_addstring_data(data, len);
4018 bufchain_consume(&c->v.v2.outbuffer, len);
4019 c->v.v2.remwindow -= len;
4023 * After having sent as much data as we can, return the amount
4026 return bufchain_size(&c->v.v2.outbuffer);
4030 * Potentially enlarge the window on an SSH2 channel.
4032 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4035 * Never send WINDOW_ADJUST for a channel that the remote side
4036 * already thinks it's closed; there's no point, since it won't
4037 * be sending any more data anyway.
4042 if (newwin > c->v.v2.locwindow) {
4043 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4044 ssh2_pkt_adduint32(c->remoteid);
4045 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4047 c->v.v2.locwindow = newwin;
4052 * Handle the SSH2 userauth and connection layers.
4054 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4057 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4059 AUTH_KEYBOARD_INTERACTIVE
4063 AUTH_TYPE_PUBLICKEY,
4064 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4065 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4067 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4068 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4070 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4071 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
4072 static int kbd_inter_running;
4073 static int we_are_in;
4074 static int num_prompts, curr_prompt, echo;
4075 static char username[100];
4076 static int got_username;
4077 static char pwprompt[200];
4078 static char password[100];
4079 static void *publickey_blob;
4080 static int publickey_bloblen;
4085 * Request userauth protocol, and await a response to it.
4087 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4088 ssh2_pkt_addstring("ssh-userauth");
4090 crWaitUntilV(ispkt);
4091 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4092 bombout(("Server refused user authentication protocol"));
4097 * We repeat this whole loop, including the username prompt,
4098 * until we manage a successful authentication. If the user
4099 * types the wrong _password_, they are sent back to the
4100 * beginning to try another username. (If they specify a
4101 * username in the config, they are never asked, even if they
4102 * do give a wrong password.)
4104 * I think this best serves the needs of
4106 * - the people who have no configuration, no keys, and just
4107 * want to try repeated (username,password) pairs until they
4108 * type both correctly
4110 * - people who have keys and configuration but occasionally
4111 * need to fall back to passwords
4113 * - people with a key held in Pageant, who might not have
4114 * logged in to a particular machine before; so they want to
4115 * type a username, and then _either_ their key will be
4116 * accepted, _or_ they will type a password. If they mistype
4117 * the username they will want to be able to get back and
4121 got_username = FALSE;
4126 if (got_username && !cfg.change_username) {
4128 * We got a username last time round this loop, and
4129 * with change_username turned off we don't try to get
4132 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4133 if (ssh_get_line && !ssh_getline_pw_only) {
4134 if (!ssh_get_line("login as: ",
4135 username, sizeof(username), FALSE)) {
4137 * get_line failed to get a username.
4140 logevent("No username provided. Abandoning session.");
4141 ssh_state = SSH_STATE_CLOSED;
4146 c_write_str("login as: ");
4148 setup_userpass_input(username, sizeof(username), 1);
4150 crWaitUntilV(!ispkt);
4151 ret = process_userpass_input(in, inlen);
4156 c_write_str("\r\n");
4157 username[strcspn(username, "\n\r")] = '\0';
4160 strncpy(username, cfg.username, 99);
4161 username[99] = '\0';
4162 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4163 sprintf(stuff, "Using username \"%s\".\r\n", username);
4167 got_username = TRUE;
4170 * Send an authentication request using method "none": (a)
4171 * just in case it succeeds, and (b) so that we know what
4172 * authentication methods we can usefully try next.
4174 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4176 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4177 ssh2_pkt_addstring(username);
4178 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4179 ssh2_pkt_addstring("none"); /* method */
4181 type = AUTH_TYPE_NONE;
4185 tried_pubkey_config = FALSE;
4186 tried_agent = FALSE;
4187 tried_keyb_inter = FALSE;
4188 kbd_inter_running = FALSE;
4189 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4192 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4193 keytype = key_type(cfg.keyfile);
4194 if (keytype == SSH_KEYTYPE_SSH2)
4195 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4196 &publickey_bloblen);
4199 logeventf("Unable to use this key file (%s)",
4200 key_type_to_str(keytype));
4201 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4202 cfg.keyfile, key_type_to_str(keytype));
4203 c_write_str(msgbuf);
4204 publickey_blob = NULL;
4207 publickey_blob = NULL;
4211 * Wait for the result of the last authentication request.
4214 crWaitUntilV(ispkt);
4215 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4219 * Don't show the banner if we're operating in
4220 * non-verbose non-interactive mode. (It's probably
4221 * a script, which means nobody will read the
4222 * banner _anyway_, and moreover the printing of
4223 * the banner will screw up processing on the
4224 * output of (say) plink.)
4226 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4227 ssh2_pkt_getstring(&banner, &size);
4229 c_write_untrusted(banner, size);
4231 crWaitUntilV(ispkt);
4233 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4234 logevent("Access granted");
4239 if (kbd_inter_running &&
4240 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4242 * This is either a further set-of-prompts packet
4243 * in keyboard-interactive authentication, or it's
4244 * the same one and we came back here with `gotit'
4245 * set. In the former case, we must reset the
4246 * curr_prompt variable.
4250 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4251 bombout(("Strange packet received during authentication: type %d",
4259 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4260 * we can look at the string in it and know what we can
4261 * helpfully try next.
4263 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4266 ssh2_pkt_getstring(&methods, &methlen);
4267 kbd_inter_running = FALSE;
4268 if (!ssh2_pkt_getbool()) {
4270 * We have received an unequivocal Access
4271 * Denied. This can translate to a variety of
4274 * - if we'd just tried "none" authentication,
4275 * it's not worth printing anything at all
4277 * - if we'd just tried a public key _offer_,
4278 * the message should be "Server refused our
4279 * key" (or no message at all if the key
4280 * came from Pageant)
4282 * - if we'd just tried anything else, the
4283 * message really should be "Access denied".
4285 * Additionally, if we'd just tried password
4286 * authentication, we should break out of this
4287 * whole loop so as to go back to the username
4290 if (type == AUTH_TYPE_NONE) {
4292 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4293 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4294 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4295 c_write_str("Server refused our key\r\n");
4296 logevent("Server refused public key");
4297 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4298 /* server declined keyboard-interactive; ignore */
4300 c_write_str("Access denied\r\n");
4301 logevent("Access denied");
4302 if (type == AUTH_TYPE_PASSWORD) {
4308 c_write_str("Further authentication required\r\n");
4309 logevent("Further authentication required");
4313 in_commasep_string("publickey", methods, methlen);
4315 in_commasep_string("password", methods, methlen);
4316 can_keyb_inter = cfg.try_ki_auth &&
4317 in_commasep_string("keyboard-interactive", methods, methlen);
4321 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4324 * Most password/passphrase prompts will be
4325 * non-echoing, so we set this to 0 by default.
4326 * Exception is that some keyboard-interactive prompts
4327 * can be echoing, in which case we'll set this to 1.
4331 if (!method && can_pubkey && agent_exists() && !tried_agent) {
4333 * Attempt public-key authentication using Pageant.
4335 static unsigned char request[5], *response, *p;
4336 static int responselen;
4337 static int i, nkeys;
4338 static int authed = FALSE;
4341 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4342 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4346 logevent("Pageant is running. Requesting keys.");
4348 /* Request the keys held by the agent. */
4349 PUT_32BIT(request, 1);
4350 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4351 agent_query(request, 5, &r, &responselen);
4352 response = (unsigned char *) r;
4353 if (response && responselen >= 5 &&
4354 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4356 nkeys = GET_32BIT(p);
4360 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4363 for (i = 0; i < nkeys; i++) {
4364 static char *pkblob, *alg, *commentp;
4365 static int pklen, alglen, commentlen;
4366 static int siglen, retlen, len;
4367 static char *q, *agentreq, *ret;
4372 sprintf(buf, "Trying Pageant key #%d", i);
4375 pklen = GET_32BIT(p);
4377 if (publickey_blob &&
4378 pklen == publickey_bloblen &&
4379 !memcmp(p, publickey_blob, publickey_bloblen)) {
4380 logevent("This key matches configured key file");
4381 tried_pubkey_config = 1;
4385 alglen = GET_32BIT(pkblob);
4387 commentlen = GET_32BIT(p);
4391 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4392 ssh2_pkt_addstring(username);
4393 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4394 ssh2_pkt_addstring("publickey"); /* method */
4395 ssh2_pkt_addbool(FALSE); /* no signature included */
4396 ssh2_pkt_addstring_start();
4397 ssh2_pkt_addstring_data(alg, alglen);
4398 ssh2_pkt_addstring_start();
4399 ssh2_pkt_addstring_data(pkblob, pklen);
4402 crWaitUntilV(ispkt);
4403 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4404 logevent("Key refused");
4408 if (flags & FLAG_VERBOSE) {
4410 ("Authenticating with public key \"");
4411 c_write(commentp, commentlen);
4412 c_write_str("\" from agent\r\n");
4416 * Server is willing to accept the key.
4417 * Construct a SIGN_REQUEST.
4419 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4420 ssh2_pkt_addstring(username);
4421 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4422 ssh2_pkt_addstring("publickey"); /* method */
4423 ssh2_pkt_addbool(TRUE);
4424 ssh2_pkt_addstring_start();
4425 ssh2_pkt_addstring_data(alg, alglen);
4426 ssh2_pkt_addstring_start();
4427 ssh2_pkt_addstring_data(pkblob, pklen);
4429 siglen = pktout.length - 5 + 4 + 20;
4430 len = 1; /* message type */
4431 len += 4 + pklen; /* key blob */
4432 len += 4 + siglen; /* data to sign */
4433 len += 4; /* flags */
4434 agentreq = smalloc(4 + len);
4435 PUT_32BIT(agentreq, len);
4437 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4438 PUT_32BIT(q, pklen);
4440 memcpy(q, pkblob, pklen);
4442 PUT_32BIT(q, siglen);
4444 /* Now the data to be signed... */
4447 memcpy(q, ssh2_session_id, 20);
4449 memcpy(q, pktout.data + 5, pktout.length - 5);
4450 q += pktout.length - 5;
4451 /* And finally the (zero) flags word. */
4453 agent_query(agentreq, len + 4, &vret, &retlen);
4457 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4458 logevent("Sending Pageant's response");
4459 ssh2_add_sigblob(pkblob, pklen,
4460 ret + 9, GET_32BIT(ret + 5));
4466 ("Pageant failed to answer challenge");
4476 if (!method && can_pubkey && publickey_blob
4477 && !tried_pubkey_config) {
4478 unsigned char *pub_blob;
4479 char *algorithm, *comment;
4482 tried_pubkey_config = TRUE;
4484 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4485 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4488 * Try the public key supplied in the configuration.
4490 * First, offer the public blob to see if the server is
4491 * willing to accept it.
4493 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4496 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4497 ssh2_pkt_addstring(username);
4498 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4499 ssh2_pkt_addstring("publickey"); /* method */
4500 ssh2_pkt_addbool(FALSE); /* no signature included */
4501 ssh2_pkt_addstring(algorithm);
4502 ssh2_pkt_addstring_start();
4503 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4505 logevent("Offered public key"); /* FIXME */
4507 crWaitUntilV(ispkt);
4508 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4510 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4511 continue; /* key refused; give up on it */
4514 logevent("Offer of public key accepted");
4516 * Actually attempt a serious authentication using
4519 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4521 "Passphrase for key \"%.100s\": ",
4527 c_write_str("Authenticating with public key \"");
4528 c_write_str(comment);
4529 c_write_str("\"\r\n");
4530 method = AUTH_PUBLICKEY_FILE;
4534 if (!method && can_keyb_inter && !tried_keyb_inter) {
4535 method = AUTH_KEYBOARD_INTERACTIVE;
4536 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4537 tried_keyb_inter = TRUE;
4539 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4540 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4542 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4543 ssh2_pkt_addstring(username);
4544 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4545 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4546 ssh2_pkt_addstring(""); /* lang */
4547 ssh2_pkt_addstring("");
4550 crWaitUntilV(ispkt);
4551 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4552 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4554 logevent("Keyboard-interactive authentication refused");
4555 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4559 kbd_inter_running = TRUE;
4563 if (kbd_inter_running) {
4564 method = AUTH_KEYBOARD_INTERACTIVE;
4565 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4566 tried_keyb_inter = TRUE;
4568 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4569 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4571 if (curr_prompt == 0) {
4573 * We've got a fresh USERAUTH_INFO_REQUEST.
4574 * Display header data, and start going through
4577 char *name, *inst, *lang;
4578 int name_len, inst_len, lang_len;
4580 ssh2_pkt_getstring(&name, &name_len);
4581 ssh2_pkt_getstring(&inst, &inst_len);
4582 ssh2_pkt_getstring(&lang, &lang_len);
4584 c_write_untrusted(name, name_len);
4585 c_write_str("\r\n");
4588 c_write_untrusted(inst, inst_len);
4589 c_write_str("\r\n");
4591 num_prompts = ssh2_pkt_getuint32();
4595 * If there are prompts remaining in the packet,
4596 * display one and get a response.
4598 if (curr_prompt < num_prompts) {
4602 ssh2_pkt_getstring(&prompt, &prompt_len);
4603 if (prompt_len > 0) {
4604 strncpy(pwprompt, prompt, sizeof(pwprompt));
4605 pwprompt[prompt_len < sizeof(pwprompt) ?
4606 prompt_len : sizeof(pwprompt)-1] = '\0';
4609 "<server failed to send prompt>: ");
4611 echo = ssh2_pkt_getbool();
4617 if (!method && can_passwd) {
4618 method = AUTH_PASSWORD;
4619 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4620 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4621 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4628 if (!ssh_get_line(pwprompt, password,
4629 sizeof(password), TRUE)) {
4631 * get_line failed to get a password (for
4632 * example because one was supplied on the
4633 * command line which has already failed to
4636 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4637 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4639 ("No more passwords available to try");
4640 ssh2_pkt_addstring("en"); /* language tag */
4642 logevent("Unable to authenticate");
4643 connection_fatal("Unable to authenticate");
4644 ssh_state = SSH_STATE_CLOSED;
4649 c_write_untrusted(pwprompt, strlen(pwprompt));
4652 setup_userpass_input(password, sizeof(password), echo);
4654 crWaitUntilV(!ispkt);
4655 ret = process_userpass_input(in, inlen);
4659 c_write_str("\r\n");
4663 if (method == AUTH_PUBLICKEY_FILE) {
4665 * We have our passphrase. Now try the actual authentication.
4667 struct ssh2_userkey *key;
4669 key = ssh2_load_userkey(cfg.keyfile, password);
4670 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4671 if (key == SSH2_WRONG_PASSPHRASE) {
4672 c_write_str("Wrong passphrase\r\n");
4673 tried_pubkey_config = FALSE;
4675 c_write_str("Unable to load private key\r\n");
4676 tried_pubkey_config = TRUE;
4678 /* Send a spurious AUTH_NONE to return to the top. */
4679 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4680 ssh2_pkt_addstring(username);
4681 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4682 ssh2_pkt_addstring("none"); /* method */
4684 type = AUTH_TYPE_NONE;
4686 unsigned char *pkblob, *sigblob, *sigdata;
4687 int pkblob_len, sigblob_len, sigdata_len;
4690 * We have loaded the private key and the server
4691 * has announced that it's willing to accept it.
4692 * Hallelujah. Generate a signature and send it.
4694 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4695 ssh2_pkt_addstring(username);
4696 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4697 ssh2_pkt_addstring("publickey"); /* method */
4698 ssh2_pkt_addbool(TRUE);
4699 ssh2_pkt_addstring(key->alg->name);
4700 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4701 ssh2_pkt_addstring_start();
4702 ssh2_pkt_addstring_data(pkblob, pkblob_len);
4705 * The data to be signed is:
4709 * followed by everything so far placed in the
4712 sigdata_len = pktout.length - 5 + 4 + 20;
4713 sigdata = smalloc(sigdata_len);
4714 PUT_32BIT(sigdata, 20);
4715 memcpy(sigdata + 4, ssh2_session_id, 20);
4716 memcpy(sigdata + 24, pktout.data + 5,
4718 sigblob = key->alg->sign(key->data, sigdata,
4719 sigdata_len, &sigblob_len);
4720 ssh2_add_sigblob(pkblob, pkblob_len,
4721 sigblob, sigblob_len);
4727 type = AUTH_TYPE_PUBLICKEY;
4729 } else if (method == AUTH_PASSWORD) {
4731 * We send the password packet lumped tightly together with
4732 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4733 * string long enough to make the total length of the two
4734 * packets constant. This should ensure that a passive
4735 * listener doing traffic analyis can't work out the length
4738 * For this to work, we need an assumption about the
4739 * maximum length of the password packet. I think 256 is
4740 * pretty conservative. Anyone using a password longer than
4741 * that probably doesn't have much to worry about from
4742 * people who find out how long their password is!
4744 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4745 ssh2_pkt_addstring(username);
4746 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4747 ssh2_pkt_addstring("password");
4748 ssh2_pkt_addbool(FALSE);
4749 ssh2_pkt_addstring(password);
4752 * We'll include a string that's an exact multiple of the
4753 * cipher block size. If the cipher is NULL for some
4754 * reason, we don't do this trick at all because we gain
4760 stringlen = (256 - deferred_len);
4761 stringlen += cscipher->blksize - 1;
4762 stringlen -= (stringlen % cscipher->blksize);
4765 * Temporarily disable actual compression,
4766 * so we can guarantee to get this string
4767 * exactly the length we want it. The
4768 * compression-disabling routine should
4769 * return an integer indicating how many
4770 * bytes we should adjust our string length
4773 stringlen -= cscomp->disable_compression();
4775 ssh2_pkt_init(SSH2_MSG_IGNORE);
4776 ssh2_pkt_addstring_start();
4777 for (i = 0; i < stringlen; i++) {
4778 char c = (char) random_byte();
4779 ssh2_pkt_addstring_data(&c, 1);
4783 ssh_pkt_defersend();
4784 logevent("Sent password");
4785 type = AUTH_TYPE_PASSWORD;
4786 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4787 if (curr_prompt == 0) {
4788 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4789 ssh2_pkt_adduint32(num_prompts);
4791 if (need_pw) { /* only add pw if we just got one! */
4792 ssh2_pkt_addstring(password);
4793 memset(password, 0, sizeof(password));
4796 if (curr_prompt >= num_prompts) {
4800 * If there are prompts remaining, we set
4801 * `gotit' so that we won't attempt to get
4802 * another packet. Then we go back round the
4803 * loop and will end up retrieving another
4804 * prompt out of the existing packet. Funky or
4809 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4812 ("No supported authentication methods left to try!\r\n");
4814 ("No supported authentications offered. Disconnecting");
4815 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4816 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4818 ("No supported authentication methods available");
4819 ssh2_pkt_addstring("en"); /* language tag */
4821 ssh_state = SSH_STATE_CLOSED;
4825 } while (!we_are_in);
4828 * Now we're authenticated for the connection protocol. The
4829 * connection protocol will automatically have started at this
4830 * point; there's no need to send SERVICE_REQUEST.
4834 * So now create a channel with a session in it.
4836 ssh_channels = newtree234(ssh_channelcmp);
4837 mainchan = smalloc(sizeof(struct ssh_channel));
4838 mainchan->localid = alloc_channel_id();
4839 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4840 ssh2_pkt_addstring("session");
4841 ssh2_pkt_adduint32(mainchan->localid);
4842 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4843 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4844 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4846 crWaitUntilV(ispkt);
4847 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4848 bombout(("Server refused to open a session"));
4850 /* FIXME: error data comes back in FAILURE packet */
4852 if (ssh2_pkt_getuint32() != mainchan->localid) {
4853 bombout(("Server's channel confirmation cited wrong channel"));
4856 mainchan->remoteid = ssh2_pkt_getuint32();
4857 mainchan->type = CHAN_MAINSESSION;
4858 mainchan->closes = 0;
4859 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4860 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4861 bufchain_init(&mainchan->v.v2.outbuffer);
4862 add234(ssh_channels, mainchan);
4863 logevent("Opened channel for session");
4866 * Potentially enable X11 forwarding.
4868 if (cfg.x11_forward) {
4869 char proto[20], data[64];
4870 logevent("Requesting X11 forwarding");
4871 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4872 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4873 ssh2_pkt_adduint32(mainchan->remoteid);
4874 ssh2_pkt_addstring("x11-req");
4875 ssh2_pkt_addbool(1); /* want reply */
4876 ssh2_pkt_addbool(0); /* many connections */
4877 ssh2_pkt_addstring(proto);
4878 ssh2_pkt_addstring(data);
4879 ssh2_pkt_adduint32(0); /* screen number */
4883 crWaitUntilV(ispkt);
4884 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4885 unsigned i = ssh2_pkt_getuint32();
4886 struct ssh_channel *c;
4887 c = find234(ssh_channels, &i, ssh_channelfind);
4889 continue; /* nonexistent channel */
4890 c->v.v2.remwindow += ssh2_pkt_getuint32();
4892 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4894 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4895 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4896 bombout(("Unexpected response to X11 forwarding request:"
4897 " packet type %d", pktin.type));
4900 logevent("X11 forwarding refused");
4902 logevent("X11 forwarding enabled");
4903 ssh_X11_fwd_enabled = TRUE;
4908 * Enable port forwardings.
4911 static char *e; /* preserve across crReturn */
4914 int sport,dport,sserv,dserv;
4915 char sports[256], dports[256], host[256];
4919 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4920 /* Add port forwardings. */
4925 while (*e && *e != '\t')
4931 while (*e && *e != ':')
4941 dport = atoi(dports);
4945 se = getservbyname(dports, NULL);
4947 dport = ntohs(se->s_port);
4950 "Service lookup failed for destination port \"%s\"",
4955 sport = atoi(sports);
4959 se = getservbyname(sports, NULL);
4961 sport = ntohs(se->s_port);
4964 "Service lookup failed for source port \"%s\"",
4969 if (sport && dport) {
4971 pfd_addforward(host, dport, sport);
4972 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
4973 " %s:%.*s%.*s%d%.*s",
4974 sserv ? strlen(sports) : 0, sports,
4975 sserv, "(", sport, sserv, ")",
4977 dserv ? strlen(dports) : 0, dports,
4978 dserv, "(", dport, dserv, ")");
4981 struct ssh_rportfwd *pf;
4982 pf = smalloc(sizeof(*pf));
4983 strcpy(pf->dhost, host);
4986 if (add234(ssh_rportfwds, pf) != pf) {
4988 "Duplicate remote port forwarding to %s:%d",
4993 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
4994 " forward to %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, ")");
5001 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5002 ssh2_pkt_addstring("tcpip-forward");
5003 ssh2_pkt_addbool(1);/* want reply */
5004 if (cfg.rport_acceptall)
5005 ssh2_pkt_addstring("0.0.0.0");
5007 ssh2_pkt_addstring("127.0.0.1");
5008 ssh2_pkt_adduint32(sport);
5012 crWaitUntilV(ispkt);
5013 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5014 unsigned i = ssh2_pkt_getuint32();
5015 struct ssh_channel *c;
5016 c = find234(ssh_channels, &i, ssh_channelfind);
5018 continue;/* nonexistent channel */
5019 c->v.v2.remwindow += ssh2_pkt_getuint32();
5021 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5023 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5024 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5025 bombout(("Unexpected response to port "
5026 "forwarding request: packet type %d",
5030 logevent("Server refused this port forwarding");
5032 logevent("Remote port forwarding enabled");
5041 * Potentially enable agent forwarding.
5043 if (cfg.agentfwd && agent_exists()) {
5044 logevent("Requesting OpenSSH-style agent forwarding");
5045 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5046 ssh2_pkt_adduint32(mainchan->remoteid);
5047 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5048 ssh2_pkt_addbool(1); /* want reply */
5052 crWaitUntilV(ispkt);
5053 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5054 unsigned i = ssh2_pkt_getuint32();
5055 struct ssh_channel *c;
5056 c = find234(ssh_channels, &i, ssh_channelfind);
5058 continue; /* nonexistent channel */
5059 c->v.v2.remwindow += ssh2_pkt_getuint32();
5061 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5063 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5064 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5065 bombout(("Unexpected response to agent forwarding request:"
5066 " packet type %d", pktin.type));
5069 logevent("Agent forwarding refused");
5071 logevent("Agent forwarding enabled");
5072 ssh_agentfwd_enabled = TRUE;
5077 * Now allocate a pty for the session.
5080 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5081 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5082 ssh2_pkt_addstring("pty-req");
5083 ssh2_pkt_addbool(1); /* want reply */
5084 ssh2_pkt_addstring(cfg.termtype);
5085 ssh2_pkt_adduint32(cols);
5086 ssh2_pkt_adduint32(rows);
5087 ssh2_pkt_adduint32(0); /* pixel width */
5088 ssh2_pkt_adduint32(0); /* pixel height */
5089 ssh2_pkt_addstring_start();
5090 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5092 ssh_state = SSH_STATE_INTERMED;
5095 crWaitUntilV(ispkt);
5096 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5097 unsigned i = ssh2_pkt_getuint32();
5098 struct ssh_channel *c;
5099 c = find234(ssh_channels, &i, ssh_channelfind);
5101 continue; /* nonexistent channel */
5102 c->v.v2.remwindow += ssh2_pkt_getuint32();
5104 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5106 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5107 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5108 bombout(("Unexpected response to pty request:"
5109 " packet type %d", pktin.type));
5112 c_write_str("Server refused to allocate pty\r\n");
5113 ssh_editing = ssh_echoing = 1;
5115 logevent("Allocated pty");
5118 ssh_editing = ssh_echoing = 1;
5122 * Start a shell or a remote command. We may have to attempt
5123 * this twice if the config data has provided a second choice
5130 if (ssh_fallback_cmd) {
5131 subsys = cfg.ssh_subsys2;
5132 cmd = cfg.remote_cmd_ptr2;
5134 subsys = cfg.ssh_subsys;
5135 cmd = cfg.remote_cmd_ptr;
5138 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5139 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5141 ssh2_pkt_addstring("subsystem");
5142 ssh2_pkt_addbool(1); /* want reply */
5143 ssh2_pkt_addstring(cmd);
5145 ssh2_pkt_addstring("exec");
5146 ssh2_pkt_addbool(1); /* want reply */
5147 ssh2_pkt_addstring(cmd);
5149 ssh2_pkt_addstring("shell");
5150 ssh2_pkt_addbool(1); /* want reply */
5154 crWaitUntilV(ispkt);
5155 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5156 unsigned i = ssh2_pkt_getuint32();
5157 struct ssh_channel *c;
5158 c = find234(ssh_channels, &i, ssh_channelfind);
5160 continue; /* nonexistent channel */
5161 c->v.v2.remwindow += ssh2_pkt_getuint32();
5163 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5164 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5165 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5166 bombout(("Unexpected response to shell/command request:"
5167 " packet type %d", pktin.type));
5171 * We failed to start the command. If this is the
5172 * fallback command, we really are finished; if it's
5173 * not, and if the fallback command exists, try falling
5174 * back to it before complaining.
5176 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5177 logevent("Primary command failed; attempting fallback");
5178 ssh_fallback_cmd = TRUE;
5181 bombout(("Server refused to start a shell/command"));
5184 logevent("Started a shell/command");
5189 ssh_state = SSH_STATE_SESSION;
5193 ssh_special(TS_EOF);
5198 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
5201 static int try_send;
5205 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
5206 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5209 unsigned i = ssh2_pkt_getuint32();
5210 struct ssh_channel *c;
5211 c = find234(ssh_channels, &i, ssh_channelfind);
5213 continue; /* nonexistent channel */
5214 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5215 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5216 continue; /* extended but not stderr */
5217 ssh2_pkt_getstring(&data, &length);
5220 c->v.v2.locwindow -= length;
5222 case CHAN_MAINSESSION:
5224 from_backend(pktin.type ==
5225 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5229 bufsize = x11_send(c->u.x11.s, data, length);
5232 bufsize = pfd_send(c->u.pfd.s, data, length);
5235 while (length > 0) {
5236 if (c->u.a.lensofar < 4) {
5237 int l = min(4 - c->u.a.lensofar, length);
5238 memcpy(c->u.a.msglen + c->u.a.lensofar,
5242 c->u.a.lensofar += l;
5244 if (c->u.a.lensofar == 4) {
5246 4 + GET_32BIT(c->u.a.msglen);
5247 c->u.a.message = smalloc(c->u.a.totallen);
5248 memcpy(c->u.a.message, c->u.a.msglen, 4);
5250 if (c->u.a.lensofar >= 4 && length > 0) {
5252 min(c->u.a.totallen - c->u.a.lensofar,
5254 memcpy(c->u.a.message + c->u.a.lensofar,
5258 c->u.a.lensofar += l;
5260 if (c->u.a.lensofar == c->u.a.totallen) {
5261 void *reply, *sentreply;
5263 agent_query(c->u.a.message,
5264 c->u.a.totallen, &reply,
5269 /* Fake SSH_AGENT_FAILURE. */
5270 sentreply = "\0\0\0\1\5";
5273 ssh2_add_channel_data(c, sentreply,
5278 sfree(c->u.a.message);
5279 c->u.a.lensofar = 0;
5286 * If we are not buffering too much data,
5287 * enlarge the window again at the remote side.
5289 if (bufsize < OUR_V2_WINSIZE)
5290 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5292 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
5293 ssh_state = SSH_STATE_CLOSED;
5294 logevent("Received disconnect message");
5296 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
5297 unsigned i = ssh2_pkt_getuint32();
5298 struct ssh_channel *c;
5300 c = find234(ssh_channels, &i, ssh_channelfind);
5302 continue; /* nonexistent channel */
5304 if (c->type == CHAN_X11) {
5306 * Remote EOF on an X11 channel means we should
5307 * wrap up and close the channel ourselves.
5309 x11_close(c->u.x11.s);
5311 } else if (c->type == CHAN_AGENT) {
5313 } else if (c->type == CHAN_SOCKDATA) {
5314 pfd_close(c->u.pfd.s);
5317 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5318 unsigned i = ssh2_pkt_getuint32();
5319 struct ssh_channel *c;
5321 c = find234(ssh_channels, &i, ssh_channelfind);
5323 continue; /* nonexistent channel */
5324 /* Do pre-close processing on the channel. */
5326 case CHAN_MAINSESSION:
5327 break; /* nothing to see here, move along */
5329 if (c->u.x11.s != NULL)
5330 x11_close(c->u.x11.s);
5337 if (c->u.pfd.s != NULL)
5338 pfd_close(c->u.pfd.s);
5342 if (c->closes == 0) {
5343 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5344 ssh2_pkt_adduint32(c->remoteid);
5347 del234(ssh_channels, c);
5348 bufchain_clear(&c->v.v2.outbuffer);
5352 * See if that was the last channel left open.
5354 if (count234(ssh_channels) == 0) {
5357 * We used to send SSH_MSG_DISCONNECT here,
5358 * because I'd believed that _every_ conforming
5359 * SSH2 connection had to end with a disconnect
5360 * being sent by at least one side; apparently
5361 * I was wrong and it's perfectly OK to
5362 * unceremoniously slam the connection shut
5363 * when you're done, and indeed OpenSSH feels
5364 * this is more polite than sending a
5365 * DISCONNECT. So now we don't.
5367 logevent("All channels closed. Disconnecting");
5368 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5369 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5370 ssh2_pkt_addstring("All open channels closed");
5371 ssh2_pkt_addstring("en"); /* language tag */
5374 ssh_state = SSH_STATE_CLOSED;
5377 continue; /* remote sends close; ignore (FIXME) */
5378 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5379 unsigned i = ssh2_pkt_getuint32();
5380 struct ssh_channel *c;
5381 c = find234(ssh_channels, &i, ssh_channelfind);
5383 continue; /* nonexistent channel */
5384 c->v.v2.remwindow += ssh2_pkt_getuint32();
5386 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5387 unsigned i = ssh2_pkt_getuint32();
5388 struct ssh_channel *c;
5389 c = find234(ssh_channels, &i, ssh_channelfind);
5391 continue; /* nonexistent channel */
5392 if (c->type != CHAN_SOCKDATA_DORMANT)
5393 continue; /* dunno why they're confirming this */
5394 c->remoteid = ssh2_pkt_getuint32();
5395 c->type = CHAN_SOCKDATA;
5396 c->v.v2.remwindow = ssh2_pkt_getuint32();
5397 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5399 pfd_confirm(c->u.pfd.s);
5402 * We have a pending close on this channel,
5403 * which we decided on before the server acked
5404 * the channel open. So now we know the
5405 * remoteid, we can close it again.
5407 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5408 ssh2_pkt_adduint32(c->remoteid);
5411 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5412 unsigned i = ssh2_pkt_getuint32();
5413 struct ssh_channel *c;
5414 c = find234(ssh_channels, &i, ssh_channelfind);
5416 continue; /* nonexistent channel */
5417 if (c->type != CHAN_SOCKDATA_DORMANT)
5418 continue; /* dunno why they're failing this */
5420 logevent("Forwarded connection refused by server");
5422 pfd_close(c->u.pfd.s);
5424 del234(ssh_channels, c);
5426 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5429 int typelen, want_reply;
5430 struct ssh_channel *c;
5432 localid = ssh2_pkt_getuint32();
5433 ssh2_pkt_getstring(&type, &typelen);
5434 want_reply = ssh2_pkt_getbool();
5437 * First, check that the channel exists. Otherwise,
5438 * we can instantly disconnect with a rude message.
5440 c = find234(ssh_channels, &localid, ssh_channelfind);
5443 sprintf(buf, "Received channel request for nonexistent"
5444 " channel %d", localid);
5446 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5447 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5448 ssh2_pkt_addstring(buf);
5449 ssh2_pkt_addstring("en"); /* language tag */
5451 connection_fatal("%s", buf);
5452 ssh_state = SSH_STATE_CLOSED;
5457 * Having got the channel number, we now look at
5458 * the request type string to see if it's something
5461 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5463 /* We recognise "exit-status" on the primary channel. */
5465 ssh_exitcode = ssh2_pkt_getuint32();
5466 sprintf(buf, "Server sent command exit status %d",
5470 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5471 ssh2_pkt_adduint32(c->remoteid);
5476 * This is a channel request we don't know
5477 * about, so we now either ignore the request
5478 * or respond with CHANNEL_FAILURE, depending
5482 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5483 ssh2_pkt_adduint32(c->remoteid);
5487 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5489 int typelen, want_reply;
5491 ssh2_pkt_getstring(&type, &typelen);
5492 want_reply = ssh2_pkt_getbool();
5495 * We currently don't support any global requests
5496 * at all, so we either ignore the request or
5497 * respond with REQUEST_FAILURE, depending on
5501 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5504 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5508 struct ssh_channel *c;
5509 unsigned remid, winsize, pktsize;
5510 ssh2_pkt_getstring(&type, &typelen);
5511 c = smalloc(sizeof(struct ssh_channel));
5513 remid = ssh2_pkt_getuint32();
5514 winsize = ssh2_pkt_getuint32();
5515 pktsize = ssh2_pkt_getuint32();
5517 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5518 if (!ssh_X11_fwd_enabled)
5519 error = "X11 forwarding is not enabled";
5520 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5522 error = "Unable to open an X11 connection";
5526 } else if (typelen == 15 &&
5527 !memcmp(type, "forwarded-tcpip", 15)) {
5528 struct ssh_rportfwd pf, *realpf;
5531 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5532 pf.sport = ssh2_pkt_getuint32();
5533 realpf = find234(ssh_rportfwds, &pf, NULL);
5534 if (realpf == NULL) {
5535 error = "Remote port is not recognised";
5537 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5540 sprintf(buf, "Received remote port open request for %s:%d",
5541 realpf->dhost, realpf->dport);
5544 sprintf(buf, "Port open failed: %s", e);
5546 error = "Port open failed";
5548 logevent("Forwarded port opened successfully");
5549 c->type = CHAN_SOCKDATA;
5552 } else if (typelen == 22 &&
5553 !memcmp(type, "auth-agent@openssh.com", 3)) {
5554 if (!ssh_agentfwd_enabled)
5555 error = "Agent forwarding is not enabled";
5557 c->type = CHAN_AGENT; /* identify channel type */
5558 c->u.a.lensofar = 0;
5561 error = "Unsupported channel type requested";
5564 c->remoteid = remid;
5566 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5567 ssh2_pkt_adduint32(c->remoteid);
5568 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5569 ssh2_pkt_addstring(error);
5570 ssh2_pkt_addstring("en"); /* language tag */
5574 c->localid = alloc_channel_id();
5576 c->v.v2.locwindow = OUR_V2_WINSIZE;
5577 c->v.v2.remwindow = winsize;
5578 c->v.v2.remmaxpkt = pktsize;
5579 bufchain_init(&c->v.v2.outbuffer);
5580 add234(ssh_channels, c);
5581 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5582 ssh2_pkt_adduint32(c->remoteid);
5583 ssh2_pkt_adduint32(c->localid);
5584 ssh2_pkt_adduint32(c->v.v2.locwindow);
5585 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5589 bombout(("Strange packet received: type %d", pktin.type));
5594 * We have spare data. Add it to the channel buffer.
5596 ssh2_add_channel_data(mainchan, in, inlen);
5601 struct ssh_channel *c;
5603 * Try to send data on all channels if we can.
5605 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5606 int bufsize = ssh2_try_send(c);
5609 case CHAN_MAINSESSION:
5610 /* stdin need not receive an unthrottle
5611 * notification since it will be polled */
5614 x11_unthrottle(c->u.x11.s);
5617 /* agent sockets are request/response and need no
5618 * buffer management */
5621 pfd_unthrottle(c->u.pfd.s);
5633 * Handle the top-level SSH2 protocol.
5635 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5637 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5639 do_ssh2_authconn(in, inlen, ispkt);
5643 * Called to set up the connection.
5645 * Returns an error message, or NULL on success.
5647 static char *ssh_init(char *host, int port, char **realhost, int nodelay)
5652 if (crypto_startup() == 0)
5653 return "Microsoft high encryption pack not installed!";
5659 ssh1_throttle_count = 0;
5660 ssh_overall_bufsize = 0;
5661 ssh_fallback_cmd = 0;
5663 p = connect_to_host(host, port, realhost, nodelay);
5671 * Called to send data down the Telnet connection.
5673 static int ssh_send(char *buf, int len)
5675 if (s == NULL || ssh_protocol == NULL)
5678 ssh_protocol(buf, len, 0);
5680 return ssh_sendbuffer();
5684 * Called to query the current amount of buffered stdin data.
5686 static int ssh_sendbuffer(void)
5690 if (s == NULL || ssh_protocol == NULL)
5694 * If the SSH socket itself has backed up, add the total backup
5695 * size on that to any individual buffer on the stdin channel.
5698 if (ssh_throttled_all)
5699 override_value = ssh_overall_bufsize;
5701 if (ssh_version == 1) {
5702 return override_value;
5703 } else if (ssh_version == 2) {
5704 if (!mainchan || mainchan->closes > 0)
5705 return override_value;
5707 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5714 * Called to set the size of the window from SSH's POV.
5716 static void ssh_size(void)
5718 switch (ssh_state) {
5719 case SSH_STATE_BEFORE_SIZE:
5720 case SSH_STATE_PREPACKET:
5721 case SSH_STATE_CLOSED:
5722 break; /* do nothing */
5723 case SSH_STATE_INTERMED:
5724 size_needed = TRUE; /* buffer for later */
5726 case SSH_STATE_SESSION:
5728 if (ssh_version == 1) {
5729 send_packet(SSH1_CMSG_WINDOW_SIZE,
5730 PKT_INT, rows, PKT_INT, cols,
5731 PKT_INT, 0, PKT_INT, 0, PKT_END);
5733 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5734 ssh2_pkt_adduint32(mainchan->remoteid);
5735 ssh2_pkt_addstring("window-change");
5736 ssh2_pkt_addbool(0);
5737 ssh2_pkt_adduint32(cols);
5738 ssh2_pkt_adduint32(rows);
5739 ssh2_pkt_adduint32(0);
5740 ssh2_pkt_adduint32(0);
5749 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5750 * can send an EOF and collect resulting output (e.g. `plink
5753 static void ssh_special(Telnet_Special code)
5755 if (code == TS_EOF) {
5756 if (ssh_state != SSH_STATE_SESSION) {
5758 * Buffer the EOF in case we are pre-SESSION, so we can
5759 * send it as soon as we reach SESSION.
5765 if (ssh_version == 1) {
5766 send_packet(SSH1_CMSG_EOF, PKT_END);
5768 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5769 ssh2_pkt_adduint32(mainchan->remoteid);
5772 logevent("Sent EOF message");
5773 } else if (code == TS_PING) {
5774 if (ssh_state == SSH_STATE_CLOSED
5775 || ssh_state == SSH_STATE_PREPACKET) return;
5776 if (ssh_version == 1) {
5777 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5779 ssh2_pkt_init(SSH2_MSG_IGNORE);
5780 ssh2_pkt_addstring_start();
5788 void *new_sock_channel(Socket s)
5790 struct ssh_channel *c;
5791 c = smalloc(sizeof(struct ssh_channel));
5794 c->remoteid = -1; /* to be set when open confirmed */
5795 c->localid = alloc_channel_id();
5797 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5799 bufchain_init(&c->v.v2.outbuffer);
5800 add234(ssh_channels, c);
5806 * This is called when stdout/stderr (the entity to which
5807 * from_backend sends data) manages to clear some backlog.
5809 void ssh_unthrottle(int bufsize)
5811 if (ssh_version == 1) {
5812 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5813 ssh1_stdout_throttling = 0;
5817 if (mainchan && mainchan->closes == 0)
5818 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5822 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5824 struct ssh_channel *c = (struct ssh_channel *)channel;
5827 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5830 if (ssh_version == 1) {
5831 send_packet(SSH1_MSG_PORT_OPEN,
5832 PKT_INT, c->localid,
5835 //PKT_STR, <org:orgport>,
5838 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5839 ssh2_pkt_addstring("direct-tcpip");
5840 ssh2_pkt_adduint32(c->localid);
5841 c->v.v2.locwindow = OUR_V2_WINSIZE;
5842 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5843 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5844 ssh2_pkt_addstring(hostname);
5845 ssh2_pkt_adduint32(port);
5847 * We make up values for the originator data; partly it's
5848 * too much hassle to keep track, and partly I'm not
5849 * convinced the server should be told details like that
5850 * about my local network configuration.
5852 ssh2_pkt_addstring("client-side-connection");
5853 ssh2_pkt_adduint32(0);
5859 static Socket ssh_socket(void)
5864 static int ssh_sendok(void)
5869 static int ssh_ldisc(int option)
5871 if (option == LD_ECHO)
5873 if (option == LD_EDIT)
5878 static int ssh_return_exitcode(void)
5880 return ssh_exitcode;
5883 Backend ssh_backend = {
5890 ssh_return_exitcode,