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];
518 int (*ssh_get_line) (const char *prompt, char *str, int maxlen,
521 static char *savedhost;
522 static int savedport;
523 static int ssh_send_ok;
524 static int ssh_echoing, ssh_editing;
526 static tree234 *ssh_channels; /* indexed by local id */
527 static struct ssh_channel *mainchan; /* primary session channel */
528 static int ssh_exitcode = -1;
530 static tree234 *ssh_rportfwds;
534 SSH_STATE_BEFORE_SIZE,
538 } ssh_state = SSH_STATE_PREPACKET;
540 static int size_needed = FALSE, eof_needed = FALSE;
542 static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
543 static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
544 static unsigned char *deferred_send_data = NULL;
545 static int deferred_len = 0, deferred_size = 0;
548 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
549 * that fails. This variable is the means by which scp.c can reach
550 * into the SSH code and find out which one it got.
552 int ssh_fallback_cmd = 0;
554 static int ssh_version;
555 static int ssh1_throttle_count;
556 static int ssh_overall_bufsize;
557 static int ssh_throttled_all;
558 static int ssh1_stdout_throttling;
559 static void (*ssh_protocol) (unsigned char *in, int inlen, int ispkt);
560 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
561 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
562 static void ssh_size(void);
563 static void ssh_special(Telnet_Special);
564 static int ssh2_try_send(struct ssh_channel *c);
565 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
567 static void ssh_throttle_all(int enable, int bufsize);
568 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
569 static int (*s_rdpkt) (unsigned char **data, int *datalen);
570 static int ssh_sendbuffer(void);
572 static struct rdpkt1_state_tag {
573 long len, pad, biglen, to_read;
574 unsigned long realcrc, gotcrc;
580 static struct rdpkt2_state_tag {
581 long len, pad, payload, packetlen, maclen;
584 unsigned long incoming_sequence;
587 static int ssh_channelcmp(void *av, void *bv)
589 struct ssh_channel *a = (struct ssh_channel *) av;
590 struct ssh_channel *b = (struct ssh_channel *) bv;
591 if (a->localid < b->localid)
593 if (a->localid > b->localid)
597 static int ssh_channelfind(void *av, void *bv)
599 unsigned *a = (unsigned *) av;
600 struct ssh_channel *b = (struct ssh_channel *) bv;
608 static int ssh_rportcmp_ssh1(void *av, void *bv)
610 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
611 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
613 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
614 return i < 0 ? -1 : +1;
615 if (a->dport > b->dport)
617 if (a->dport < b->dport)
622 static int ssh_rportcmp_ssh2(void *av, void *bv)
624 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
625 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
627 if (a->sport > b->sport)
629 if (a->sport < b->sport)
634 static int alloc_channel_id(void)
636 const unsigned CHANNEL_NUMBER_OFFSET = 256;
637 unsigned low, high, mid;
639 struct ssh_channel *c;
642 * First-fit allocation of channel numbers: always pick the
643 * lowest unused one. To do this, binary-search using the
644 * counted B-tree to find the largest channel ID which is in a
645 * contiguous sequence from the beginning. (Precisely
646 * everything in that sequence must have ID equal to its tree
647 * index plus CHANNEL_NUMBER_OFFSET.)
649 tsize = count234(ssh_channels);
653 while (high - low > 1) {
654 mid = (high + low) / 2;
655 c = index234(ssh_channels, mid);
656 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
657 low = mid; /* this one is fine */
659 high = mid; /* this one is past it */
662 * Now low points to either -1, or the tree index of the
663 * largest ID in the initial sequence.
666 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
667 assert(NULL == find234(ssh_channels, &i, ssh_channelfind));
669 return low + 1 + CHANNEL_NUMBER_OFFSET;
672 static void c_write(char *buf, int len)
674 if ((flags & FLAG_STDERR)) {
676 for (i = 0; i < len; i++)
678 fputc(buf[i], stderr);
681 from_backend(1, buf, len);
684 static void c_write_untrusted(char *buf, int len)
687 for (i = 0; i < len; i++) {
690 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
695 static void c_write_str(char *buf)
697 c_write(buf, strlen(buf));
701 * Collect incoming data in the incoming packet buffer.
702 * Decipher and verify the packet when it is completely read.
703 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
704 * Update the *data and *datalen variables.
705 * Return the additional nr of bytes needed, or 0 when
706 * a complete packet is available.
708 static int ssh1_rdpkt(unsigned char **data, int *datalen)
710 struct rdpkt1_state_tag *st = &rdpkt1_state;
719 for (st->i = st->len = 0; st->i < 4; st->i++) {
720 while ((*datalen) == 0)
722 st->len = (st->len << 8) + **data;
723 (*data)++, (*datalen)--;
726 st->pad = 8 - (st->len % 8);
727 st->biglen = st->len + st->pad;
728 pktin.length = st->len - 5;
730 if (pktin.maxlen < st->biglen) {
731 pktin.maxlen = st->biglen;
732 pktin.data = (pktin.data == NULL ? smalloc(st->biglen + APIEXTRA) :
733 srealloc(pktin.data, st->biglen + APIEXTRA));
735 fatalbox("Out of memory");
738 st->to_read = st->biglen;
740 while (st->to_read > 0) {
741 st->chunk = st->to_read;
742 while ((*datalen) == 0)
743 crReturn(st->to_read);
744 if (st->chunk > (*datalen))
745 st->chunk = (*datalen);
746 memcpy(st->p, *data, st->chunk);
748 *datalen -= st->chunk;
750 st->to_read -= st->chunk;
753 if (cipher && detect_attack(pktin.data, st->biglen, NULL)) {
754 bombout(("Network attack (CRC compensation) detected!"));
759 cipher->decrypt(pktin.data, st->biglen);
761 st->realcrc = crc32(pktin.data, st->biglen - 4);
762 st->gotcrc = GET_32BIT(pktin.data + st->biglen - 4);
763 if (st->gotcrc != st->realcrc) {
764 bombout(("Incorrect CRC received on packet"));
768 pktin.body = pktin.data + st->pad + 1;
770 if (ssh1_compressing) {
771 unsigned char *decompblk;
773 zlib_decompress_block(pktin.body - 1, pktin.length + 1,
774 &decompblk, &decomplen);
776 if (pktin.maxlen < st->pad + decomplen) {
777 pktin.maxlen = st->pad + decomplen;
778 pktin.data = srealloc(pktin.data, pktin.maxlen + APIEXTRA);
779 pktin.body = pktin.data + st->pad + 1;
781 fatalbox("Out of memory");
784 memcpy(pktin.body - 1, decompblk, decomplen);
786 pktin.length = decomplen - 1;
789 pktin.type = pktin.body[-1];
791 log_packet(PKT_INCOMING, pktin.type, ssh1_pkt_type(pktin.type),
792 pktin.body, pktin.length);
794 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
795 pktin.type == SSH1_SMSG_STDERR_DATA ||
796 pktin.type == SSH1_MSG_DEBUG ||
797 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
798 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
799 long stringlen = GET_32BIT(pktin.body);
800 if (stringlen + 4 != pktin.length) {
801 bombout(("Received data packet with bogus string length"));
806 if (pktin.type == SSH1_MSG_DEBUG) {
807 /* log debug message */
809 int stringlen = GET_32BIT(pktin.body);
810 strcpy(buf, "Remote: ");
813 memcpy(buf + 8, pktin.body + 4, stringlen);
814 buf[8 + stringlen] = '\0';
817 } else if (pktin.type == SSH1_MSG_IGNORE) {
822 if (pktin.type == SSH1_MSG_DISCONNECT) {
823 /* log reason code in disconnect message */
825 unsigned msglen = GET_32BIT(pktin.body);
827 strcpy(buf, "Remote sent disconnect: ");
828 nowlen = strlen(buf);
829 if (msglen > sizeof(buf) - nowlen - 1)
830 msglen = sizeof(buf) - nowlen - 1;
831 memcpy(buf + nowlen, pktin.body + 4, msglen);
832 buf[nowlen + msglen] = '\0';
833 /* logevent(buf); (this is now done within the bombout macro) */
834 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
841 static int ssh2_rdpkt(unsigned char **data, int *datalen)
843 struct rdpkt2_state_tag *st = &rdpkt2_state;
851 st->cipherblk = sccipher->blksize;
854 if (st->cipherblk < 8)
857 if (pktin.maxlen < st->cipherblk) {
858 pktin.maxlen = st->cipherblk;
861 NULL ? smalloc(st->cipherblk +
862 APIEXTRA) : srealloc(pktin.data,
866 fatalbox("Out of memory");
870 * Acquire and decrypt the first block of the packet. This will
871 * contain the length and padding details.
873 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
874 while ((*datalen) == 0)
875 crReturn(st->cipherblk - st->i);
876 pktin.data[st->i] = *(*data)++;
881 sccipher->decrypt(pktin.data, st->cipherblk);
884 * Now get the length and padding figures.
886 st->len = GET_32BIT(pktin.data);
887 st->pad = pktin.data[4];
890 * This enables us to deduce the payload length.
892 st->payload = st->len - st->pad - 1;
894 pktin.length = st->payload + 5;
897 * So now we can work out the total packet length.
899 st->packetlen = st->len + 4;
900 st->maclen = scmac ? scmac->len : 0;
903 * Adjust memory allocation if packet is too big.
905 if (pktin.maxlen < st->packetlen + st->maclen) {
906 pktin.maxlen = st->packetlen + st->maclen;
909 NULL ? smalloc(pktin.maxlen + APIEXTRA) : srealloc(pktin.data,
914 fatalbox("Out of memory");
918 * Read and decrypt the remainder of the packet.
920 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
922 while ((*datalen) == 0)
923 crReturn(st->packetlen + st->maclen - st->i);
924 pktin.data[st->i] = *(*data)++;
927 /* Decrypt everything _except_ the MAC. */
929 sccipher->decrypt(pktin.data + st->cipherblk,
930 st->packetlen - st->cipherblk);
936 && !scmac->verify(pktin.data, st->len + 4,
937 st->incoming_sequence)) {
938 bombout(("Incorrect MAC received on packet"));
941 st->incoming_sequence++; /* whether or not we MACed */
944 * Decompress packet payload.
947 unsigned char *newpayload;
949 if (sccomp && sccomp->decompress(pktin.data + 5, pktin.length - 5,
950 &newpayload, &newlen)) {
951 if (pktin.maxlen < newlen + 5) {
952 pktin.maxlen = newlen + 5;
955 NULL ? smalloc(pktin.maxlen +
956 APIEXTRA) : srealloc(pktin.data,
960 fatalbox("Out of memory");
962 pktin.length = 5 + newlen;
963 memcpy(pktin.data + 5, newpayload, newlen);
969 pktin.type = pktin.data[5];
971 log_packet(PKT_INCOMING, pktin.type, ssh2_pkt_type(pktin.type),
972 pktin.data+6, pktin.length-6);
974 switch (pktin.type) {
976 * These packets we must handle instantly.
978 case SSH2_MSG_DISCONNECT:
980 /* log reason code in disconnect message */
982 int reason = GET_32BIT(pktin.data + 6);
983 unsigned msglen = GET_32BIT(pktin.data + 10);
985 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
986 sprintf(buf, "Received disconnect message (%s)",
987 ssh2_disconnect_reasons[reason]);
989 sprintf(buf, "Received disconnect message (unknown type %d)",
993 strcpy(buf, "Disconnection message text: ");
994 nowlen = strlen(buf);
995 if (msglen > sizeof(buf) - nowlen - 1)
996 msglen = sizeof(buf) - nowlen - 1;
997 memcpy(buf + nowlen, pktin.data + 14, msglen);
998 buf[nowlen + msglen] = '\0';
1000 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1002 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1003 ssh2_disconnect_reasons[reason] : "unknown",
1008 case SSH2_MSG_IGNORE:
1010 case SSH2_MSG_DEBUG:
1012 /* log the debug message */
1014 /* int display = pktin.body[6]; */
1015 int stringlen = GET_32BIT(pktin.data+7);
1017 strcpy(buf, "Remote debug message: ");
1018 prefix = strlen(buf);
1019 if (stringlen > sizeof(buf)-prefix-1)
1020 stringlen = sizeof(buf)-prefix-1;
1021 memcpy(buf + prefix, pktin.data + 11, stringlen);
1022 buf[prefix + stringlen] = '\0';
1025 goto next_packet; /* FIXME: print the debug message */
1028 * These packets we need do nothing about here.
1030 case SSH2_MSG_UNIMPLEMENTED:
1031 case SSH2_MSG_SERVICE_REQUEST:
1032 case SSH2_MSG_SERVICE_ACCEPT:
1033 case SSH2_MSG_KEXINIT:
1034 case SSH2_MSG_NEWKEYS:
1035 case SSH2_MSG_KEXDH_INIT:
1036 case SSH2_MSG_KEXDH_REPLY:
1037 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1038 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1039 case SSH2_MSG_KEX_DH_GEX_INIT:
1040 case SSH2_MSG_KEX_DH_GEX_REPLY:
1041 case SSH2_MSG_USERAUTH_REQUEST:
1042 case SSH2_MSG_USERAUTH_FAILURE:
1043 case SSH2_MSG_USERAUTH_SUCCESS:
1044 case SSH2_MSG_USERAUTH_BANNER:
1045 case SSH2_MSG_USERAUTH_PK_OK:
1046 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1047 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1048 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1049 case SSH2_MSG_GLOBAL_REQUEST:
1050 case SSH2_MSG_REQUEST_SUCCESS:
1051 case SSH2_MSG_REQUEST_FAILURE:
1052 case SSH2_MSG_CHANNEL_OPEN:
1053 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1054 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1055 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1056 case SSH2_MSG_CHANNEL_DATA:
1057 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1058 case SSH2_MSG_CHANNEL_EOF:
1059 case SSH2_MSG_CHANNEL_CLOSE:
1060 case SSH2_MSG_CHANNEL_REQUEST:
1061 case SSH2_MSG_CHANNEL_SUCCESS:
1062 case SSH2_MSG_CHANNEL_FAILURE:
1066 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1069 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
1070 ssh2_pkt_adduint32(st->incoming_sequence - 1);
1078 static void ssh1_pktout_size(int len)
1082 len += 5; /* type and CRC */
1083 pad = 8 - (len % 8);
1086 pktout.length = len - 5;
1087 if (pktout.maxlen < biglen) {
1088 pktout.maxlen = biglen;
1090 /* Allocate enough buffer space for extra block
1091 * for MS CryptEncrypt() */
1092 pktout.data = (pktout.data == NULL ? smalloc(biglen + 12) :
1093 srealloc(pktout.data, biglen + 12));
1095 pktout.data = (pktout.data == NULL ? smalloc(biglen + 4) :
1096 srealloc(pktout.data, biglen + 4));
1099 fatalbox("Out of memory");
1101 pktout.body = pktout.data + 4 + pad + 1;
1104 static void s_wrpkt_start(int type, int len)
1106 ssh1_pktout_size(len);
1110 static int s_wrpkt_prepare(void)
1112 int pad, len, biglen, i;
1115 pktout.body[-1] = pktout.type;
1117 log_packet(PKT_OUTGOING, pktout.type, ssh1_pkt_type(pktout.type),
1118 pktout.body, pktout.length);
1120 if (ssh1_compressing) {
1121 unsigned char *compblk;
1123 zlib_compress_block(pktout.body - 1, pktout.length + 1,
1124 &compblk, &complen);
1125 ssh1_pktout_size(complen - 1);
1126 memcpy(pktout.body - 1, compblk, complen);
1130 len = pktout.length + 5; /* type and CRC */
1131 pad = 8 - (len % 8);
1134 for (i = 0; i < pad; i++)
1135 pktout.data[i + 4] = random_byte();
1136 crc = crc32(pktout.data + 4, biglen - 4);
1137 PUT_32BIT(pktout.data + biglen, crc);
1138 PUT_32BIT(pktout.data, len);
1141 cipher->encrypt(pktout.data + 4, biglen);
1146 static void s_wrpkt(void)
1149 len = s_wrpkt_prepare();
1150 backlog = sk_write(s, pktout.data, len);
1151 if (backlog > SSH_MAX_BACKLOG)
1152 ssh_throttle_all(1, backlog);
1155 static void s_wrpkt_defer(void)
1158 len = s_wrpkt_prepare();
1159 if (deferred_len + len > deferred_size) {
1160 deferred_size = deferred_len + len + 128;
1161 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1163 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1164 deferred_len += len;
1168 * Construct a packet with the specified contents.
1170 static void construct_packet(int pkttype, va_list ap1, va_list ap2)
1172 unsigned char *p, *argp, argchar;
1173 unsigned long argint;
1174 int pktlen, argtype, arglen;
1178 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1181 (void) va_arg(ap1, int);
1185 (void) va_arg(ap1, char);
1189 (void) va_arg(ap1, unsigned char *);
1190 arglen = va_arg(ap1, int);
1194 argp = va_arg(ap1, unsigned char *);
1195 arglen = strlen(argp);
1196 pktlen += 4 + arglen;
1199 bn = va_arg(ap1, Bignum);
1200 pktlen += ssh1_bignum_length(bn);
1207 s_wrpkt_start(pkttype, pktlen);
1210 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1213 argint = va_arg(ap2, int);
1214 PUT_32BIT(p, argint);
1218 argchar = va_arg(ap2, unsigned char);
1223 argp = va_arg(ap2, unsigned char *);
1224 arglen = va_arg(ap2, int);
1225 memcpy(p, argp, arglen);
1229 argp = va_arg(ap2, unsigned char *);
1230 arglen = strlen(argp);
1231 PUT_32BIT(p, arglen);
1232 memcpy(p + 4, argp, arglen);
1236 bn = va_arg(ap2, Bignum);
1237 p += ssh1_write_bignum(p, bn);
1243 static void send_packet(int pkttype, ...)
1246 va_start(ap1, pkttype);
1247 va_start(ap2, pkttype);
1248 construct_packet(pkttype, ap1, ap2);
1252 static void defer_packet(int pkttype, ...)
1255 va_start(ap1, pkttype);
1256 va_start(ap2, pkttype);
1257 construct_packet(pkttype, ap1, ap2);
1261 static int ssh_versioncmp(char *a, char *b)
1264 unsigned long av, bv;
1266 av = strtoul(a, &ae, 10);
1267 bv = strtoul(b, &be, 10);
1269 return (av < bv ? -1 : +1);
1274 av = strtoul(ae, &ae, 10);
1275 bv = strtoul(be, &be, 10);
1277 return (av < bv ? -1 : +1);
1283 * Utility routines for putting an SSH-protocol `string' and
1284 * `uint32' into a SHA state.
1287 static void sha_string(SHA_State * s, void *str, int len)
1289 unsigned char lenblk[4];
1290 PUT_32BIT(lenblk, len);
1291 SHA_Bytes(s, lenblk, 4);
1292 SHA_Bytes(s, str, len);
1295 static void sha_uint32(SHA_State * s, unsigned i)
1297 unsigned char intblk[4];
1298 PUT_32BIT(intblk, i);
1299 SHA_Bytes(s, intblk, 4);
1303 * SSH2 packet construction functions.
1305 static void ssh2_pkt_ensure(int length)
1307 if (pktout.maxlen < length) {
1308 pktout.maxlen = length + 256;
1311 NULL ? smalloc(pktout.maxlen +
1312 APIEXTRA) : srealloc(pktout.data,
1316 fatalbox("Out of memory");
1319 static void ssh2_pkt_adddata(void *data, int len)
1321 pktout.length += len;
1322 ssh2_pkt_ensure(pktout.length);
1323 memcpy(pktout.data + pktout.length - len, data, len);
1325 static void ssh2_pkt_addbyte(unsigned char byte)
1327 ssh2_pkt_adddata(&byte, 1);
1329 static void ssh2_pkt_init(int pkt_type)
1332 ssh2_pkt_addbyte((unsigned char) pkt_type);
1334 static void ssh2_pkt_addbool(unsigned char value)
1336 ssh2_pkt_adddata(&value, 1);
1338 static void ssh2_pkt_adduint32(unsigned long value)
1341 PUT_32BIT(x, value);
1342 ssh2_pkt_adddata(x, 4);
1344 static void ssh2_pkt_addstring_start(void)
1346 ssh2_pkt_adduint32(0);
1347 pktout.savedpos = pktout.length;
1349 static void ssh2_pkt_addstring_str(char *data)
1351 ssh2_pkt_adddata(data, strlen(data));
1352 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1353 pktout.length - pktout.savedpos);
1355 static void ssh2_pkt_addstring_data(char *data, int len)
1357 ssh2_pkt_adddata(data, len);
1358 PUT_32BIT(pktout.data + pktout.savedpos - 4,
1359 pktout.length - pktout.savedpos);
1361 static void ssh2_pkt_addstring(char *data)
1363 ssh2_pkt_addstring_start();
1364 ssh2_pkt_addstring_str(data);
1366 static char *ssh2_mpint_fmt(Bignum b, int *len)
1369 int i, n = (bignum_bitcount(b) + 7) / 8;
1372 fatalbox("out of memory");
1374 for (i = 1; i <= n; i++)
1375 p[i] = bignum_byte(b, n - i);
1377 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1379 memmove(p, p + i, n + 1 - i);
1383 static void ssh2_pkt_addmp(Bignum b)
1387 p = ssh2_mpint_fmt(b, &len);
1388 ssh2_pkt_addstring_start();
1389 ssh2_pkt_addstring_data(p, len);
1394 * Construct an SSH2 final-form packet: compress it, encrypt it,
1395 * put the MAC on it. Final packet, ready to be sent, is stored in
1396 * pktout.data. Total length is returned.
1398 static int ssh2_pkt_construct(void)
1400 int cipherblk, maclen, padding, i;
1401 static unsigned long outgoing_sequence = 0;
1403 log_packet(PKT_OUTGOING, pktout.data[5], ssh2_pkt_type(pktout.data[5]),
1404 pktout.data + 6, pktout.length - 6);
1407 * Compress packet payload.
1410 unsigned char *newpayload;
1412 if (cscomp && cscomp->compress(pktout.data + 5, pktout.length - 5,
1413 &newpayload, &newlen)) {
1415 ssh2_pkt_adddata(newpayload, newlen);
1421 * Add padding. At least four bytes, and must also bring total
1422 * length (minus MAC) up to a multiple of the block size.
1424 cipherblk = cscipher ? cscipher->blksize : 8; /* block size */
1425 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1428 (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
1429 maclen = csmac ? csmac->len : 0;
1430 ssh2_pkt_ensure(pktout.length + padding + maclen);
1431 pktout.data[4] = padding;
1432 for (i = 0; i < padding; i++)
1433 pktout.data[pktout.length + i] = random_byte();
1434 PUT_32BIT(pktout.data, pktout.length + padding - 4);
1436 csmac->generate(pktout.data, pktout.length + padding,
1438 outgoing_sequence++; /* whether or not we MACed */
1441 cscipher->encrypt(pktout.data, pktout.length + padding);
1443 /* Ready-to-send packet starts at pktout.data. We return length. */
1444 return pktout.length + padding + maclen;
1448 * Construct and send an SSH2 packet immediately.
1450 static void ssh2_pkt_send(void)
1454 len = ssh2_pkt_construct();
1455 backlog = sk_write(s, pktout.data, len);
1456 if (backlog > SSH_MAX_BACKLOG)
1457 ssh_throttle_all(1, backlog);
1461 * Construct an SSH2 packet and add it to a deferred data block.
1462 * Useful for sending multiple packets in a single sk_write() call,
1463 * to prevent a traffic-analysing listener from being able to work
1464 * out the length of any particular packet (such as the password
1467 * Note that because SSH2 sequence-numbers its packets, this can
1468 * NOT be used as an m4-style `defer' allowing packets to be
1469 * constructed in one order and sent in another.
1471 static void ssh2_pkt_defer(void)
1473 int len = ssh2_pkt_construct();
1474 if (deferred_len + len > deferred_size) {
1475 deferred_size = deferred_len + len + 128;
1476 deferred_send_data = srealloc(deferred_send_data, deferred_size);
1478 memcpy(deferred_send_data + deferred_len, pktout.data, len);
1479 deferred_len += len;
1483 * Send the whole deferred data block constructed by
1484 * ssh2_pkt_defer() or SSH1's defer_packet().
1486 static void ssh_pkt_defersend(void)
1489 backlog = sk_write(s, deferred_send_data, deferred_len);
1490 deferred_len = deferred_size = 0;
1491 sfree(deferred_send_data);
1492 deferred_send_data = NULL;
1493 if (backlog > SSH_MAX_BACKLOG)
1494 ssh_throttle_all(1, backlog);
1498 void bndebug(char *string, Bignum b)
1502 p = ssh2_mpint_fmt(b, &len);
1503 debug(("%s", string));
1504 for (i = 0; i < len; i++)
1505 debug((" %02x", p[i]));
1511 static void sha_mpint(SHA_State * s, Bignum b)
1515 p = ssh2_mpint_fmt(b, &len);
1516 sha_string(s, p, len);
1521 * SSH2 packet decode functions.
1523 static unsigned long ssh2_pkt_getuint32(void)
1525 unsigned long value;
1526 if (pktin.length - pktin.savedpos < 4)
1527 return 0; /* arrgh, no way to decline (FIXME?) */
1528 value = GET_32BIT(pktin.data + pktin.savedpos);
1529 pktin.savedpos += 4;
1532 static int ssh2_pkt_getbool(void)
1534 unsigned long value;
1535 if (pktin.length - pktin.savedpos < 1)
1536 return 0; /* arrgh, no way to decline (FIXME?) */
1537 value = pktin.data[pktin.savedpos] != 0;
1541 static void ssh2_pkt_getstring(char **p, int *length)
1544 if (pktin.length - pktin.savedpos < 4)
1546 *length = GET_32BIT(pktin.data + pktin.savedpos);
1547 pktin.savedpos += 4;
1548 if (pktin.length - pktin.savedpos < *length)
1550 *p = pktin.data + pktin.savedpos;
1551 pktin.savedpos += *length;
1553 static Bignum ssh2_pkt_getmp(void)
1559 ssh2_pkt_getstring(&p, &length);
1563 bombout(("internal error: Can't handle negative mpints"));
1566 b = bignum_from_bytes(p, length);
1571 * Helper function to add an SSH2 signature blob to a packet.
1572 * Expects to be shown the public key blob as well as the signature
1573 * blob. Normally works just like ssh2_pkt_addstring, but will
1574 * fiddle with the signature packet if necessary for
1575 * BUG_SSH2_RSA_PADDING.
1577 static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len,
1578 void *sigblob_v, int sigblob_len)
1580 unsigned char *pkblob = (unsigned char *)pkblob_v;
1581 unsigned char *sigblob = (unsigned char *)sigblob_v;
1583 /* dmemdump(pkblob, pkblob_len); */
1584 /* dmemdump(sigblob, sigblob_len); */
1587 * See if this is in fact an ssh-rsa signature and a buggy
1588 * server; otherwise we can just do this the easy way.
1590 if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) &&
1591 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1592 int pos, len, siglen;
1595 * Find the byte length of the modulus.
1598 pos = 4+7; /* skip over "ssh-rsa" */
1599 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1600 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1601 pos += 4; /* find modulus itself */
1602 while (len > 0 && pkblob[pos] == 0)
1604 /* debug(("modulus length is %d\n", len)); */
1607 * Now find the signature integer.
1609 pos = 4+7; /* skip over "ssh-rsa" */
1610 siglen = GET_32BIT(sigblob+pos);
1611 /* debug(("signature length is %d\n", siglen)); */
1613 if (len != siglen) {
1614 unsigned char newlen[4];
1615 ssh2_pkt_addstring_start();
1616 ssh2_pkt_addstring_data(sigblob, pos);
1617 /* dmemdump(sigblob, pos); */
1618 pos += 4; /* point to start of actual sig */
1619 PUT_32BIT(newlen, len);
1620 ssh2_pkt_addstring_data(newlen, 4);
1621 /* dmemdump(newlen, 4); */
1623 while (len-- > siglen) {
1624 ssh2_pkt_addstring_data(newlen, 1);
1625 /* dmemdump(newlen, 1); */
1627 ssh2_pkt_addstring_data(sigblob+pos, siglen);
1628 /* dmemdump(sigblob+pos, siglen); */
1632 /* Otherwise fall through and do it the easy way. */
1635 ssh2_pkt_addstring_start();
1636 ssh2_pkt_addstring_data(sigblob, sigblob_len);
1640 * Examine the remote side's version string and compare it against
1641 * a list of known buggy implementations.
1643 static void ssh_detect_bugs(char *vstring)
1645 char *imp; /* pointer to implementation part */
1647 imp += strcspn(imp, "-");
1649 imp += strcspn(imp, "-");
1652 ssh_remote_bugs = 0;
1654 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1655 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1656 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
1658 * These versions don't support SSH1_MSG_IGNORE, so we have
1659 * to use a different defence against password length
1662 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1663 logevent("We believe remote version has SSH1 ignore bug");
1666 if (!strcmp(imp, "Cisco-1.25")) {
1668 * These versions need a plain password sent; they can't
1669 * handle having a null and a random length of data after
1672 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1673 logevent("We believe remote version needs a plain SSH1 password");
1676 if (!strcmp(imp, "Cisco-1.25")) {
1678 * These versions apparently have no clue whatever about
1679 * RSA authentication and will panic and die if they see
1680 * an AUTH_RSA message.
1682 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1683 logevent("We believe remote version can't handle RSA authentication");
1686 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1687 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1688 !strncmp(imp, "2.1 ", 4)) {
1690 * These versions have the HMAC bug.
1692 ssh_remote_bugs |= BUG_SSH2_HMAC;
1693 logevent("We believe remote version has SSH2 HMAC bug");
1696 if ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1697 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')) {
1699 * These versions have the SSH2 RSA padding bug.
1701 ssh_remote_bugs |= BUG_SSH2_RSA_PADDING;
1702 logevent("We believe remote version has SSH2 RSA padding bug");
1706 static int do_ssh_init(unsigned char c)
1709 static char version[10];
1710 static char *vstring;
1711 static int vstrsize;
1717 /* Search for the string "SSH-" in the input. */
1720 static const int transS[] = { 1, 2, 2, 1 };
1721 static const int transH[] = { 0, 0, 3, 0 };
1722 static const int transminus[] = { 0, 0, 0, -1 };
1733 crReturn(1); /* get another character */
1737 vstring = smalloc(vstrsize);
1738 strcpy(vstring, "SSH-");
1742 crReturn(1); /* get another char */
1743 if (vslen >= vstrsize - 1) {
1745 vstring = srealloc(vstring, vstrsize);
1747 vstring[vslen++] = c;
1752 } else if (i < sizeof(version) - 1)
1754 } else if (c == '\n')
1758 ssh_agentfwd_enabled = FALSE;
1759 rdpkt2_state.incoming_sequence = 0;
1762 vlog = smalloc(20 + vslen);
1763 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
1764 sprintf(vlog, "Server version: %s", vstring);
1766 ssh_detect_bugs(vstring);
1770 * Server version "1.99" means we can choose whether we use v1
1771 * or v2 protocol. Choice is based on cfg.sshprot.
1773 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1775 * This is a v2 server. Begin v2 protocol.
1777 char verstring[80], vlog[100];
1778 sprintf(verstring, "SSH-2.0-%s", sshver);
1779 SHA_Init(&exhashbase);
1781 * Hash our version string and their version string.
1783 sha_string(&exhashbase, verstring, strlen(verstring));
1784 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1785 sprintf(vlog, "We claim version: %s", verstring);
1787 strcat(verstring, "\n");
1788 logevent("Using SSH protocol version 2");
1789 sk_write(s, verstring, strlen(verstring));
1790 ssh_protocol = ssh2_protocol;
1792 s_rdpkt = ssh2_rdpkt;
1795 * This is a v1 server. Begin v1 protocol.
1797 char verstring[80], vlog[100];
1798 sprintf(verstring, "SSH-%s-%s",
1799 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1801 sprintf(vlog, "We claim version: %s", verstring);
1803 strcat(verstring, "\n");
1805 if (cfg.sshprot == 3) {
1806 bombout(("SSH protocol version 2 required by user but not provided by server"));
1810 logevent("Using SSH protocol version 1");
1811 sk_write(s, verstring, strlen(verstring));
1812 ssh_protocol = ssh1_protocol;
1814 s_rdpkt = ssh1_rdpkt;
1816 ssh_state = SSH_STATE_BEFORE_SIZE;
1823 static void ssh_gotdata(unsigned char *data, int datalen)
1828 * To begin with, feed the characters one by one to the
1829 * protocol initialisation / selection function do_ssh_init().
1830 * When that returns 0, we're done with the initial greeting
1831 * exchange and can move on to packet discipline.
1836 crReturnV; /* more data please */
1837 ret = do_ssh_init(*data);
1845 * We emerge from that loop when the initial negotiation is
1846 * over and we have selected an s_rdpkt function. Now pass
1847 * everything to s_rdpkt, and then pass the resulting packets
1848 * to the proper protocol handler.
1853 while (datalen > 0) {
1854 if (s_rdpkt(&data, &datalen) == 0) {
1855 if (ssh_state == SSH_STATE_CLOSED) {
1858 ssh_protocol(NULL, 0, 1);
1859 if (ssh_state == SSH_STATE_CLOSED) {
1869 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1872 ssh_state = SSH_STATE_CLOSED;
1878 /* A socket error has occurred. */
1879 logevent(error_msg);
1880 connection_fatal(error_msg);
1882 /* Otherwise, the remote side closed the connection normally. */
1887 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1889 ssh_gotdata(data, len);
1890 if (ssh_state == SSH_STATE_CLOSED) {
1900 static void ssh_sent(Plug plug, int bufsize)
1903 * If the send backlog on the SSH socket itself clears, we
1904 * should unthrottle the whole world if it was throttled.
1906 if (bufsize < SSH_MAX_BACKLOG)
1907 ssh_throttle_all(0, bufsize);
1911 * Connect to specified host and port.
1912 * Returns an error message, or NULL on success.
1913 * Also places the canonical host name into `realhost'. It must be
1914 * freed by the caller.
1916 static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
1918 static struct plug_function_table fn_table = {
1923 }, *fn_table_ptr = &fn_table;
1932 savedhost = smalloc(1 + strlen(host));
1934 fatalbox("Out of memory");
1935 strcpy(savedhost, host);
1938 port = 22; /* default ssh port */
1953 sprintf(buf, "Looking up host \"%.170s\"", host);
1956 addr = sk_namelookup(host, realhost);
1957 if ((err = sk_addr_error(addr)))
1961 *realhost = strdup(FWhost);
1968 char buf[200], addrbuf[100];
1969 sk_getaddr(addr, addrbuf, 100);
1970 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1973 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
1974 if ((err = sk_socket_error(s))) {
1980 sk_write(s, "connect ", 8);
1981 sk_write(s, FWhost, strlen(FWhost));
1984 sprintf(buf, " %d\n", FWport);
1985 sk_write(s, buf, strlen(buf));
1993 * Throttle or unthrottle the SSH connection.
1995 static void ssh1_throttle(int adjust)
1997 int old_count = ssh1_throttle_count;
1998 ssh1_throttle_count += adjust;
1999 assert(ssh1_throttle_count >= 0);
2000 if (ssh1_throttle_count && !old_count) {
2001 sk_set_frozen(s, 1);
2002 } else if (!ssh1_throttle_count && old_count) {
2003 sk_set_frozen(s, 0);
2008 * Throttle or unthrottle _all_ local data streams (for when sends
2009 * on the SSH connection itself back up).
2011 static void ssh_throttle_all(int enable, int bufsize)
2014 struct ssh_channel *c;
2016 if (enable == ssh_throttled_all)
2018 ssh_throttled_all = enable;
2019 ssh_overall_bufsize = bufsize;
2022 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
2024 case CHAN_MAINSESSION:
2026 * This is treated separately, outside the switch.
2030 x11_override_throttle(c->u.x11.s, enable);
2033 /* Agent channels require no buffer management. */
2036 pfd_override_throttle(c->u.x11.s, enable);
2043 * Handle the key exchange and user authentication phases.
2045 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
2049 static unsigned char *rsabuf, *keystr1, *keystr2;
2050 unsigned char cookie[8];
2051 struct RSAKey servkey, hostkey;
2052 struct MD5Context md5c;
2053 static unsigned long supported_ciphers_mask, supported_auths_mask;
2054 static int tried_publickey, tried_agent;
2055 static int tis_auth_refused, ccard_auth_refused;
2056 static unsigned char session_id[16];
2057 static int cipher_type;
2058 static char username[100];
2059 static void *publickey_blob;
2060 int publickey_bloblen;
2067 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2068 bombout(("Public key packet not received"));
2072 logevent("Received public keys");
2074 memcpy(cookie, pktin.body, 8);
2076 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2077 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
2080 * Log the host key fingerprint.
2084 logevent("Host key fingerprint is:");
2085 strcpy(logmsg, " ");
2086 hostkey.comment = NULL;
2087 rsa_fingerprint(logmsg + strlen(logmsg),
2088 sizeof(logmsg) - strlen(logmsg), &hostkey);
2092 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2093 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2094 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
2096 ssh1_local_protoflags =
2097 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2098 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2101 MD5Update(&md5c, keystr2, hostkey.bytes);
2102 MD5Update(&md5c, keystr1, servkey.bytes);
2103 MD5Update(&md5c, pktin.body, 8);
2104 MD5Final(session_id, &md5c);
2106 for (i = 0; i < 32; i++)
2107 session_key[i] = random_byte();
2109 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2111 rsabuf = smalloc(len);
2113 fatalbox("Out of memory");
2116 * Verify the host key.
2120 * First format the key into a string.
2122 int len = rsastr_len(&hostkey);
2123 char fingerprint[100];
2124 char *keystr = smalloc(len);
2126 fatalbox("Out of memory");
2127 rsastr_fmt(keystr, &hostkey);
2128 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2129 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2134 for (i = 0; i < 32; i++) {
2135 rsabuf[i] = session_key[i];
2137 rsabuf[i] ^= session_id[i];
2140 if (hostkey.bytes > servkey.bytes) {
2141 rsaencrypt(rsabuf, 32, &servkey);
2142 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2144 rsaencrypt(rsabuf, 32, &hostkey);
2145 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2148 logevent("Encrypted session key");
2151 int cipher_chosen = 0, warn = 0;
2152 char *cipher_string = NULL;
2153 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2154 int next_cipher = cfg.ssh_cipherlist[i];
2155 if (next_cipher == CIPHER_WARN) {
2156 /* If/when we choose a cipher, warn about it */
2158 } else if (next_cipher == CIPHER_AES) {
2159 /* XXX Probably don't need to mention this. */
2160 logevent("AES not supported in SSH1, skipping");
2162 switch (next_cipher) {
2163 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2164 cipher_string = "3DES"; break;
2165 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2166 cipher_string = "Blowfish"; break;
2167 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2168 cipher_string = "single-DES"; break;
2170 if (supported_ciphers_mask & (1 << cipher_type))
2174 if (!cipher_chosen) {
2175 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2176 bombout(("Server violates SSH 1 protocol by not "
2177 "supporting 3DES encryption"));
2179 /* shouldn't happen */
2180 bombout(("No supported ciphers found"));
2184 /* Warn about chosen cipher if necessary. */
2186 askcipher(cipher_string, 0);
2189 switch (cipher_type) {
2190 case SSH_CIPHER_3DES:
2191 logevent("Using 3DES encryption");
2193 case SSH_CIPHER_DES:
2194 logevent("Using single-DES encryption");
2196 case SSH_CIPHER_BLOWFISH:
2197 logevent("Using Blowfish encryption");
2201 send_packet(SSH1_CMSG_SESSION_KEY,
2202 PKT_CHAR, cipher_type,
2203 PKT_DATA, cookie, 8,
2204 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2205 PKT_DATA, rsabuf, len,
2206 PKT_INT, ssh1_local_protoflags, PKT_END);
2208 logevent("Trying to enable encryption...");
2212 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2213 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
2214 cipher->sesskey(session_key);
2218 if (pktin.type != SSH1_SMSG_SUCCESS) {
2219 bombout(("Encryption not successfully enabled"));
2223 logevent("Successfully started encryption");
2229 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2231 if (!ssh_get_line("login as: ",
2232 username, sizeof(username), FALSE)) {
2234 * get_line failed to get a username.
2237 logevent("No username provided. Abandoning session.");
2238 ssh_state = SSH_STATE_CLOSED;
2242 c_write_str("login as: ");
2245 crWaitUntil(!ispkt);
2247 switch (c = *in++) {
2256 c_write_str("\b \b");
2263 c_write_str("\b \b");
2272 if (((c >= ' ' && c <= '~') ||
2273 ((unsigned char) c >= 160))
2274 && pos < sizeof(username)-1) {
2275 username[pos++] = c;
2281 c_write_str("\r\n");
2282 username[strcspn(username, "\n\r")] = '\0';
2285 strncpy(username, cfg.username, 99);
2286 username[99] = '\0';
2289 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2291 char userlog[22 + sizeof(username)];
2292 sprintf(userlog, "Sent username \"%s\"", username);
2294 if (flags & FLAG_INTERACTIVE &&
2295 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2296 strcat(userlog, "\r\n");
2297 c_write_str(userlog);
2304 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2305 /* We must not attempt PK auth. Pretend we've already tried it. */
2306 tried_publickey = tried_agent = 1;
2308 tried_publickey = tried_agent = 0;
2310 tis_auth_refused = ccard_auth_refused = 0;
2311 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2313 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2314 publickey_blob = NULL;
2316 publickey_blob = NULL;
2318 while (pktin.type == SSH1_SMSG_FAILURE) {
2319 static char password[100];
2320 static char prompt[200];
2323 static int pwpkt_type;
2324 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2326 if (agent_exists() && !tried_agent) {
2328 * Attempt RSA authentication using Pageant.
2330 static unsigned char request[5], *response, *p;
2331 static int responselen;
2332 static int i, nkeys;
2333 static int authed = FALSE;
2337 logevent("Pageant is running. Requesting keys.");
2339 /* Request the keys held by the agent. */
2340 PUT_32BIT(request, 1);
2341 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2342 agent_query(request, 5, &r, &responselen);
2343 response = (unsigned char *) r;
2344 if (response && responselen >= 5 &&
2345 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2347 nkeys = GET_32BIT(p);
2351 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2354 for (i = 0; i < nkeys; i++) {
2355 static struct RSAKey key;
2356 static Bignum challenge;
2357 static char *commentp;
2358 static int commentlen;
2362 sprintf(buf, "Trying Pageant key #%d", i);
2365 if (publickey_blob &&
2366 !memcmp(p, publickey_blob, publickey_bloblen)) {
2367 logevent("This key matches configured key file");
2368 tried_publickey = 1;
2371 p += ssh1_read_bignum(p, &key.exponent);
2372 p += ssh1_read_bignum(p, &key.modulus);
2373 commentlen = GET_32BIT(p);
2377 send_packet(SSH1_CMSG_AUTH_RSA,
2378 PKT_BIGNUM, key.modulus, PKT_END);
2380 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2381 logevent("Key refused");
2384 logevent("Received RSA challenge");
2385 ssh1_read_bignum(pktin.body, &challenge);
2387 char *agentreq, *q, *ret;
2390 len = 1 + 4; /* message type, bit count */
2391 len += ssh1_bignum_length(key.exponent);
2392 len += ssh1_bignum_length(key.modulus);
2393 len += ssh1_bignum_length(challenge);
2394 len += 16; /* session id */
2395 len += 4; /* response format */
2396 agentreq = smalloc(4 + len);
2397 PUT_32BIT(agentreq, len);
2399 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2400 PUT_32BIT(q, bignum_bitcount(key.modulus));
2402 q += ssh1_write_bignum(q, key.exponent);
2403 q += ssh1_write_bignum(q, key.modulus);
2404 q += ssh1_write_bignum(q, challenge);
2405 memcpy(q, session_id, 16);
2407 PUT_32BIT(q, 1); /* response format */
2408 agent_query(agentreq, len + 4, &vret, &retlen);
2412 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2413 logevent("Sending Pageant's response");
2414 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2415 PKT_DATA, ret + 5, 16,
2419 if (pktin.type == SSH1_SMSG_SUCCESS) {
2421 ("Pageant's response accepted");
2422 if (flags & FLAG_VERBOSE) {
2424 ("Authenticated using RSA key \"");
2425 c_write(commentp, commentlen);
2426 c_write_str("\" from agent\r\n");
2431 ("Pageant's response not accepted");
2434 ("Pageant failed to answer challenge");
2438 logevent("No reply received from Pageant");
2441 freebn(key.exponent);
2442 freebn(key.modulus);
2451 if (*cfg.keyfile && !tried_publickey)
2452 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2454 if (cfg.try_tis_auth &&
2455 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2456 !tis_auth_refused) {
2457 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2458 logevent("Requested TIS authentication");
2459 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2461 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2462 logevent("TIS authentication declined");
2463 if (flags & FLAG_INTERACTIVE)
2464 c_write_str("TIS authentication refused.\r\n");
2465 tis_auth_refused = 1;
2468 int challengelen = ((pktin.body[0] << 24) |
2469 (pktin.body[1] << 16) |
2470 (pktin.body[2] << 8) |
2472 logevent("Received TIS challenge");
2473 if (challengelen > sizeof(prompt) - 1)
2474 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2475 memcpy(prompt, pktin.body + 4, challengelen);
2476 /* Prompt heuristic comes from OpenSSH */
2477 strncpy(prompt + challengelen,
2478 memchr(prompt, '\n', challengelen) ?
2479 "": "\r\nResponse: ",
2480 (sizeof prompt) - challengelen);
2481 prompt[(sizeof prompt) - 1] = '\0';
2484 if (cfg.try_tis_auth &&
2485 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2486 !ccard_auth_refused) {
2487 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2488 logevent("Requested CryptoCard authentication");
2489 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2491 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2492 logevent("CryptoCard authentication declined");
2493 c_write_str("CryptoCard authentication refused.\r\n");
2494 ccard_auth_refused = 1;
2497 int challengelen = ((pktin.body[0] << 24) |
2498 (pktin.body[1] << 16) |
2499 (pktin.body[2] << 8) |
2501 logevent("Received CryptoCard challenge");
2502 if (challengelen > sizeof(prompt) - 1)
2503 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2504 memcpy(prompt, pktin.body + 4, challengelen);
2505 strncpy(prompt + challengelen,
2506 memchr(prompt, '\n', challengelen) ?
2507 "" : "\r\nResponse: ",
2508 sizeof(prompt) - challengelen);
2509 prompt[sizeof(prompt) - 1] = '\0';
2512 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2513 sprintf(prompt, "%.90s@%.90s's password: ",
2514 username, savedhost);
2516 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2517 char *comment = NULL;
2520 if (flags & FLAG_VERBOSE)
2521 c_write_str("Trying public key authentication.\r\n");
2522 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2524 type = key_type(cfg.keyfile);
2525 if (type != SSH_KEYTYPE_SSH1) {
2526 sprintf(msgbuf, "Key is of wrong type (%s)",
2527 key_type_to_str(type));
2529 c_write_str(msgbuf);
2530 c_write_str("\r\n");
2531 tried_publickey = 1;
2534 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2535 if (flags & FLAG_VERBOSE)
2536 c_write_str("No passphrase required.\r\n");
2539 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2544 * Show password prompt, having first obtained it via a TIS
2545 * or CryptoCard exchange if we're doing TIS or CryptoCard
2549 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2551 * get_line failed to get a password (for example
2552 * because one was supplied on the command line
2553 * which has already failed to work). Terminate.
2555 send_packet(SSH1_MSG_DISCONNECT,
2556 PKT_STR, "No more passwords available to try",
2558 logevent("Unable to authenticate");
2559 connection_fatal("Unable to authenticate");
2560 ssh_state = SSH_STATE_CLOSED;
2564 /* Prompt may have come from server. We've munged it a bit, so
2565 * we know it to be zero-terminated at least once. */
2566 c_write_untrusted(prompt, strlen(prompt));
2570 crWaitUntil(!ispkt);
2572 switch (c = *in++) {
2592 if (pos < sizeof(password)-1)
2593 password[pos++] = c;
2597 c_write_str("\r\n");
2601 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2603 * Try public key authentication with the specified
2606 static struct RSAKey pubkey;
2607 static Bignum challenge, response;
2609 static unsigned char buffer[32];
2611 tried_publickey = 1;
2612 i = loadrsakey(cfg.keyfile, &pubkey, password);
2614 c_write_str("Couldn't load private key from ");
2615 c_write_str(cfg.keyfile);
2616 c_write_str(".\r\n");
2617 continue; /* go and try password */
2620 c_write_str("Wrong passphrase.\r\n");
2621 tried_publickey = 0;
2622 continue; /* try again */
2626 * Send a public key attempt.
2628 send_packet(SSH1_CMSG_AUTH_RSA,
2629 PKT_BIGNUM, pubkey.modulus, PKT_END);
2632 if (pktin.type == SSH1_SMSG_FAILURE) {
2633 c_write_str("Server refused our public key.\r\n");
2634 continue; /* go and try password */
2636 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2637 bombout(("Bizarre response to offer of public key"));
2640 ssh1_read_bignum(pktin.body, &challenge);
2641 response = rsadecrypt(challenge, &pubkey);
2642 freebn(pubkey.private_exponent); /* burn the evidence */
2644 for (i = 0; i < 32; i++) {
2645 buffer[i] = bignum_byte(response, 31 - i);
2649 MD5Update(&md5c, buffer, 32);
2650 MD5Update(&md5c, session_id, 16);
2651 MD5Final(buffer, &md5c);
2653 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2654 PKT_DATA, buffer, 16, PKT_END);
2657 if (pktin.type == SSH1_SMSG_FAILURE) {
2658 if (flags & FLAG_VERBOSE)
2660 ("Failed to authenticate with our public key.\r\n");
2661 continue; /* go and try password */
2662 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2664 ("Bizarre response to RSA authentication response"));
2668 break; /* we're through! */
2670 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2672 * Defence against traffic analysis: we send a
2673 * whole bunch of packets containing strings of
2674 * different lengths. One of these strings is the
2675 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2676 * The others are all random data in
2677 * SSH1_MSG_IGNORE packets. This way a passive
2678 * listener can't tell which is the password, and
2679 * hence can't deduce the password length.
2681 * Anybody with a password length greater than 16
2682 * bytes is going to have enough entropy in their
2683 * password that a listener won't find it _that_
2684 * much help to know how long it is. So what we'll
2687 * - if password length < 16, we send 15 packets
2688 * containing string lengths 1 through 15
2690 * - otherwise, we let N be the nearest multiple
2691 * of 8 below the password length, and send 8
2692 * packets containing string lengths N through
2693 * N+7. This won't obscure the order of
2694 * magnitude of the password length, but it will
2695 * introduce a bit of extra uncertainty.
2697 * A few servers (the old 1.2.18 through 1.2.22)
2698 * can't deal with SSH1_MSG_IGNORE. For these
2699 * servers, we need an alternative defence. We make
2700 * use of the fact that the password is interpreted
2701 * as a C string: so we can append a NUL, then some
2704 * One server (a Cisco one) can deal with neither
2705 * SSH1_MSG_IGNORE _nor_ a padded password string.
2706 * For this server we are left with no defences
2707 * against password length sniffing.
2709 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2711 * The server can deal with SSH1_MSG_IGNORE, so
2712 * we can use the primary defence.
2714 int bottom, top, pwlen, i;
2717 pwlen = strlen(password);
2719 bottom = 0; /* zero length passwords are OK! :-) */
2722 bottom = pwlen & ~7;
2726 assert(pwlen >= bottom && pwlen <= top);
2728 randomstr = smalloc(top + 1);
2730 for (i = bottom; i <= top; i++) {
2732 defer_packet(pwpkt_type, PKT_STR, password,
2735 for (j = 0; j < i; j++) {
2737 randomstr[j] = random_byte();
2738 } while (randomstr[j] == '\0');
2740 randomstr[i] = '\0';
2741 defer_packet(SSH1_MSG_IGNORE,
2742 PKT_STR, randomstr, PKT_END);
2745 logevent("Sending password with camouflage packets");
2746 ssh_pkt_defersend();
2748 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2750 * The server can't deal with SSH1_MSG_IGNORE
2751 * but can deal with padded passwords, so we
2752 * can use the secondary defence.
2758 len = strlen(password);
2759 if (len < sizeof(string)) {
2761 strcpy(string, password);
2762 len++; /* cover the zero byte */
2763 while (len < sizeof(string)) {
2764 string[len++] = (char) random_byte();
2769 logevent("Sending length-padded password");
2770 send_packet(pwpkt_type, PKT_INT, len,
2771 PKT_DATA, s, len, PKT_END);
2774 * The server has _both_
2775 * BUG_CHOKES_ON_SSH1_IGNORE and
2776 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2777 * therefore nothing we can do.
2780 len = strlen(password);
2781 logevent("Sending unpadded password");
2782 send_packet(pwpkt_type, PKT_INT, len,
2783 PKT_DATA, password, len, PKT_END);
2786 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2789 logevent("Sent password");
2790 memset(password, 0, strlen(password));
2792 if (pktin.type == SSH1_SMSG_FAILURE) {
2793 if (flags & FLAG_VERBOSE)
2794 c_write_str("Access denied\r\n");
2795 logevent("Authentication refused");
2796 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2797 logevent("Received disconnect request");
2798 ssh_state = SSH_STATE_CLOSED;
2800 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2801 bombout(("Strange packet received, type %d", pktin.type));
2806 logevent("Authentication successful");
2811 void sshfwd_close(struct ssh_channel *c)
2813 if (c && !c->closes) {
2815 * If the channel's remoteid is -1, we have sent
2816 * CHANNEL_OPEN for this channel, but it hasn't even been
2817 * acknowledged by the server. So we must set a close flag
2818 * on it now, and then when the server acks the channel
2819 * open, we can close it then.
2821 if (((int)c->remoteid) != -1) {
2822 if (ssh_version == 1) {
2823 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2826 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2827 ssh2_pkt_adduint32(c->remoteid);
2832 if (c->type == CHAN_X11) {
2834 logevent("Forwarded X11 connection terminated");
2835 } else if (c->type == CHAN_SOCKDATA ||
2836 c->type == CHAN_SOCKDATA_DORMANT) {
2838 logevent("Forwarded port closed");
2843 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2845 if (ssh_version == 1) {
2846 send_packet(SSH1_MSG_CHANNEL_DATA,
2847 PKT_INT, c->remoteid,
2848 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2850 * In SSH1 we can return 0 here - implying that forwarded
2851 * connections are never individually throttled - because
2852 * the only circumstance that can cause throttling will be
2853 * the whole SSH connection backing up, in which case
2854 * _everything_ will be throttled as a whole.
2858 ssh2_add_channel_data(c, buf, len);
2859 return ssh2_try_send(c);
2863 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2865 if (ssh_version == 1) {
2866 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2867 c->v.v1.throttling = 0;
2871 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2875 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2881 while (!do_ssh1_login(in, inlen, ispkt)) {
2884 if (ssh_state == SSH_STATE_CLOSED)
2887 if (cfg.agentfwd && agent_exists()) {
2888 logevent("Requesting agent forwarding");
2889 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2893 if (pktin.type != SSH1_SMSG_SUCCESS
2894 && pktin.type != SSH1_SMSG_FAILURE) {
2895 bombout(("Protocol confusion"));
2897 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2898 logevent("Agent forwarding refused");
2900 logevent("Agent forwarding enabled");
2901 ssh_agentfwd_enabled = TRUE;
2905 if (cfg.x11_forward) {
2906 char proto[20], data[64];
2907 logevent("Requesting X11 forwarding");
2908 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2909 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2910 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2911 PKT_STR, proto, PKT_STR, data,
2912 PKT_INT, 0, PKT_END);
2914 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2915 PKT_STR, proto, PKT_STR, data, PKT_END);
2920 if (pktin.type != SSH1_SMSG_SUCCESS
2921 && pktin.type != SSH1_SMSG_FAILURE) {
2922 bombout(("Protocol confusion"));
2924 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2925 logevent("X11 forwarding refused");
2927 logevent("X11 forwarding enabled");
2928 ssh_X11_fwd_enabled = TRUE;
2936 int sport,dport,sserv,dserv;
2937 char sports[256], dports[256], host[256];
2941 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2942 /* Add port forwardings. */
2947 while (*e && *e != '\t')
2953 while (*e && *e != ':')
2963 dport = atoi(dports);
2967 se = getservbyname(dports, NULL);
2969 dport = ntohs(se->s_port);
2972 "Service lookup failed for destination port \"%s\"",
2977 sport = atoi(sports);
2981 se = getservbyname(sports, NULL);
2983 sport = ntohs(se->s_port);
2986 "Service lookup failed for source port \"%s\"",
2991 if (sport && dport) {
2993 pfd_addforward(host, dport, sport);
2994 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
2995 " %s:%.*s%.*s%d%.*s",
2996 sserv ? strlen(sports) : 0, sports,
2997 sserv, "(", sport, sserv, ")",
2999 dserv ? strlen(dports) : 0, dports,
3000 dserv, "(", dport, dserv, ")");
3003 struct ssh_rportfwd *pf;
3004 pf = smalloc(sizeof(*pf));
3005 strcpy(pf->dhost, host);
3007 if (add234(ssh_rportfwds, pf) != pf) {
3009 "Duplicate remote port forwarding to %s:%d",
3014 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3015 " forward to %s:%.*s%.*s%d%.*s",
3016 sserv ? strlen(sports) : 0, sports,
3017 sserv, "(", sport, sserv, ")",
3019 dserv ? strlen(dports) : 0, dports,
3020 dserv, "(", dport, dserv, ")");
3022 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3030 if (pktin.type != SSH1_SMSG_SUCCESS
3031 && pktin.type != SSH1_SMSG_FAILURE) {
3032 bombout(("Protocol confusion"));
3034 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3035 c_write_str("Server refused port forwarding\r\n");
3036 ssh_editing = ssh_echoing = 1;
3038 logevent("Remote port forwarding enabled");
3046 send_packet(SSH1_CMSG_REQUEST_PTY,
3047 PKT_STR, cfg.termtype,
3048 PKT_INT, rows, PKT_INT, cols,
3049 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3050 ssh_state = SSH_STATE_INTERMED;
3054 if (pktin.type != SSH1_SMSG_SUCCESS
3055 && pktin.type != SSH1_SMSG_FAILURE) {
3056 bombout(("Protocol confusion"));
3058 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3059 c_write_str("Server refused to allocate pty\r\n");
3060 ssh_editing = ssh_echoing = 1;
3062 logevent("Allocated pty");
3064 ssh_editing = ssh_echoing = 1;
3067 if (cfg.compression) {
3068 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3072 if (pktin.type != SSH1_SMSG_SUCCESS
3073 && pktin.type != SSH1_SMSG_FAILURE) {
3074 bombout(("Protocol confusion"));
3076 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3077 c_write_str("Server refused to compress\r\n");
3079 logevent("Started compression");
3080 ssh1_compressing = TRUE;
3081 zlib_compress_init();
3082 zlib_decompress_init();
3086 * Start the shell or command.
3088 * Special case: if the first-choice command is an SSH2
3089 * subsystem (hence not usable here) and the second choice
3090 * exists, we fall straight back to that.
3093 char *cmd = cfg.remote_cmd_ptr;
3095 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3096 cmd = cfg.remote_cmd_ptr2;
3097 ssh_fallback_cmd = TRUE;
3100 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3102 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3103 logevent("Started session");
3106 ssh_state = SSH_STATE_SESSION;
3110 ssh_special(TS_EOF);
3112 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
3114 ssh_channels = newtree234(ssh_channelcmp);
3118 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
3119 pktin.type == SSH1_SMSG_STDERR_DATA) {
3120 long len = GET_32BIT(pktin.body);
3122 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3123 pktin.body + 4, len);
3124 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3125 ssh1_stdout_throttling = 1;
3128 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
3129 ssh_state = SSH_STATE_CLOSED;
3130 logevent("Received disconnect request");
3132 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3133 /* Remote side is trying to open a channel to talk to our
3134 * X-Server. Give them back a local channel number. */
3135 struct ssh_channel *c;
3137 logevent("Received X11 connect request");
3138 /* Refuse if X11 forwarding is disabled. */
3139 if (!ssh_X11_fwd_enabled) {
3140 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3141 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3142 logevent("Rejected X11 connect request");
3144 c = smalloc(sizeof(struct ssh_channel));
3146 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3147 logevent("opening X11 forward connection failed");
3149 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3150 PKT_INT, GET_32BIT(pktin.body),
3154 ("opening X11 forward connection succeeded");
3155 c->remoteid = GET_32BIT(pktin.body);
3156 c->localid = alloc_channel_id();
3158 c->v.v1.throttling = 0;
3159 c->type = CHAN_X11; /* identify channel type */
3160 add234(ssh_channels, c);
3161 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3162 PKT_INT, c->remoteid, PKT_INT,
3163 c->localid, PKT_END);
3164 logevent("Opened X11 forward channel");
3167 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3168 /* Remote side is trying to open a channel to talk to our
3169 * agent. Give them back a local channel number. */
3170 struct ssh_channel *c;
3172 /* Refuse if agent forwarding is disabled. */
3173 if (!ssh_agentfwd_enabled) {
3174 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3175 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3177 c = smalloc(sizeof(struct ssh_channel));
3178 c->remoteid = GET_32BIT(pktin.body);
3179 c->localid = alloc_channel_id();
3181 c->v.v1.throttling = 0;
3182 c->type = CHAN_AGENT; /* identify channel type */
3183 c->u.a.lensofar = 0;
3184 add234(ssh_channels, c);
3185 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3186 PKT_INT, c->remoteid, PKT_INT, c->localid,
3189 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3190 /* Remote side is trying to open a channel to talk to a
3191 * forwarded port. Give them back a local channel number. */
3192 struct ssh_channel *c;
3193 struct ssh_rportfwd pf;
3195 char host[256], buf[1024];
3197 c = smalloc(sizeof(struct ssh_channel));
3199 hostsize = GET_32BIT(pktin.body+4);
3200 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3201 if (h+1 < host+sizeof(host))
3206 port = GET_32BIT(p);
3208 strcpy(pf.dhost, host);
3211 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3212 sprintf(buf, "Rejected remote port open request for %s:%d",
3215 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3216 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3218 sprintf(buf, "Received remote port open request for %s:%d",
3221 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3224 sprintf(buf, "Port open failed: %s", e);
3227 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3228 PKT_INT, GET_32BIT(pktin.body),
3231 c->remoteid = GET_32BIT(pktin.body);
3232 c->localid = alloc_channel_id();
3234 c->v.v1.throttling = 0;
3235 c->type = CHAN_SOCKDATA; /* identify channel type */
3236 add234(ssh_channels, c);
3237 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3238 PKT_INT, c->remoteid, PKT_INT,
3239 c->localid, PKT_END);
3240 logevent("Forwarded port opened successfully");
3244 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3245 unsigned int remoteid = GET_32BIT(pktin.body);
3246 unsigned int localid = GET_32BIT(pktin.body+4);
3247 struct ssh_channel *c;
3249 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3250 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3251 c->remoteid = localid;
3252 c->type = CHAN_SOCKDATA;
3253 c->v.v1.throttling = 0;
3254 pfd_confirm(c->u.pfd.s);
3257 if (c && c->closes) {
3259 * We have a pending close on this channel,
3260 * which we decided on before the server acked
3261 * the channel open. So now we know the
3262 * remoteid, we can close it again.
3264 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3268 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3269 unsigned int remoteid = GET_32BIT(pktin.body);
3270 unsigned int localid = GET_32BIT(pktin.body+4);
3271 struct ssh_channel *c;
3273 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3274 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3275 logevent("Forwarded connection refused by server");
3276 pfd_close(c->u.pfd.s);
3277 del234(ssh_channels, c);
3281 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3282 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3283 /* Remote side closes a channel. */
3284 unsigned i = GET_32BIT(pktin.body);
3285 struct ssh_channel *c;
3286 c = find234(ssh_channels, &i, ssh_channelfind);
3290 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3291 if (!(c->closes & closetype))
3292 send_packet(pktin.type, PKT_INT, c->remoteid,
3294 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3295 logevent("Forwarded X11 connection terminated");
3296 assert(c->u.x11.s != NULL);
3297 x11_close(c->u.x11.s);
3300 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3301 logevent("Forwarded port closed");
3302 assert(c->u.pfd.s != NULL);
3303 pfd_close(c->u.pfd.s);
3306 c->closes |= closetype;
3307 if (c->closes == 3) {
3308 del234(ssh_channels, c);
3312 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3313 /* Data sent down one of our channels. */
3314 int i = GET_32BIT(pktin.body);
3315 int len = GET_32BIT(pktin.body + 4);
3316 unsigned char *p = pktin.body + 8;
3317 struct ssh_channel *c;
3318 c = find234(ssh_channels, &i, ssh_channelfind);
3323 bufsize = x11_send(c->u.x11.s, p, len);
3326 bufsize = pfd_send(c->u.pfd.s, p, len);
3329 /* Data for an agent message. Buffer it. */
3331 if (c->u.a.lensofar < 4) {
3332 int l = min(4 - c->u.a.lensofar, len);
3333 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3337 c->u.a.lensofar += l;
3339 if (c->u.a.lensofar == 4) {
3341 4 + GET_32BIT(c->u.a.msglen);
3342 c->u.a.message = smalloc(c->u.a.totallen);
3343 memcpy(c->u.a.message, c->u.a.msglen, 4);
3345 if (c->u.a.lensofar >= 4 && len > 0) {
3347 min(c->u.a.totallen - c->u.a.lensofar,
3349 memcpy(c->u.a.message + c->u.a.lensofar, p,
3353 c->u.a.lensofar += l;
3355 if (c->u.a.lensofar == c->u.a.totallen) {
3356 void *reply, *sentreply;
3358 agent_query(c->u.a.message,
3359 c->u.a.totallen, &reply,
3364 /* Fake SSH_AGENT_FAILURE. */
3365 sentreply = "\0\0\0\1\5";
3368 send_packet(SSH1_MSG_CHANNEL_DATA,
3369 PKT_INT, c->remoteid,
3371 PKT_DATA, sentreply, replylen,
3375 sfree(c->u.a.message);
3376 c->u.a.lensofar = 0;
3379 bufsize = 0; /* agent channels never back up */
3382 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3383 c->v.v1.throttling = 1;
3387 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3388 /* may be from EXEC_SHELL on some servers */
3389 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3390 /* may be from EXEC_SHELL on some servers
3391 * if no pty is available or in other odd cases. Ignore */
3392 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3394 ssh_exitcode = GET_32BIT(pktin.body);
3395 sprintf(buf, "Server sent command exit status %d",
3398 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3400 * In case `helpful' firewalls or proxies tack
3401 * extra human-readable text on the end of the
3402 * session which we might mistake for another
3403 * encrypted packet, we close the session once
3404 * we've sent EXIT_CONFIRMATION.
3406 ssh_state = SSH_STATE_CLOSED;
3409 bombout(("Strange packet received: type %d", pktin.type));
3414 int len = min(inlen, 512);
3415 send_packet(SSH1_CMSG_STDIN_DATA,
3416 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3427 * Utility routine for decoding comma-separated strings in KEXINIT.
3429 static int in_commasep_string(char *needle, char *haystack, int haylen)
3431 int needlen = strlen(needle);
3434 * Is it at the start of the string?
3436 if (haylen >= needlen && /* haystack is long enough */
3437 !memcmp(needle, haystack, needlen) && /* initial match */
3438 (haylen == needlen || haystack[needlen] == ',')
3439 /* either , or EOS follows */
3443 * If not, search for the next comma and resume after that.
3444 * If no comma found, terminate.
3446 while (haylen > 0 && *haystack != ',')
3447 haylen--, haystack++;
3450 haylen--, haystack++; /* skip over comma itself */
3455 * SSH2 key creation method.
3457 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3461 /* First 20 bytes. */
3464 SHA_Bytes(&s, H, 20);
3465 SHA_Bytes(&s, &chr, 1);
3466 SHA_Bytes(&s, sessid, 20);
3467 SHA_Final(&s, keyspace);
3468 /* Next 20 bytes. */
3471 SHA_Bytes(&s, H, 20);
3472 SHA_Bytes(&s, keyspace, 20);
3473 SHA_Final(&s, keyspace + 20);
3477 * Handle the SSH2 transport layer.
3479 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3481 static int i, j, len, nbits, pbits, warn;
3483 static Bignum p, g, e, f, K;
3484 static int kex_init_value, kex_reply_value;
3485 static const struct ssh_mac **maclist;
3487 static const struct ssh2_cipher *cscipher_tobe = NULL;
3488 static const struct ssh2_cipher *sccipher_tobe = NULL;
3489 static const struct ssh_mac *csmac_tobe = NULL;
3490 static const struct ssh_mac *scmac_tobe = NULL;
3491 static const struct ssh_compress *cscomp_tobe = NULL;
3492 static const struct ssh_compress *sccomp_tobe = NULL;
3493 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3494 static int hostkeylen, siglen;
3495 static void *hkey; /* actual host key */
3496 static unsigned char exchange_hash[20];
3497 static unsigned char keyspace[40];
3498 static int n_preferred_ciphers;
3499 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3500 static const struct ssh_compress *preferred_comp;
3501 static int cipherstr_started;
3502 static int first_kex;
3509 * Set up the preferred ciphers. (NULL => warn below here)
3511 n_preferred_ciphers = 0;
3512 for (i = 0; i < CIPHER_MAX; i++) {
3513 switch (cfg.ssh_cipherlist[i]) {
3514 case CIPHER_BLOWFISH:
3515 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3516 n_preferred_ciphers++;
3519 if (cfg.ssh2_des_cbc) {
3520 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3521 n_preferred_ciphers++;
3525 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3526 n_preferred_ciphers++;
3529 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3530 n_preferred_ciphers++;
3533 /* Flag for later. Don't bother if it's the last in
3535 if (i < CIPHER_MAX - 1) {
3536 preferred_ciphers[n_preferred_ciphers] = NULL;
3537 n_preferred_ciphers++;
3544 * Set up preferred compression.
3546 if (cfg.compression)
3547 preferred_comp = &ssh_zlib;
3549 preferred_comp = &ssh_comp_none;
3552 * Be prepared to work around the buggy MAC problem.
3554 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3555 maclist = buggymacs, nmacs = lenof(buggymacs);
3557 maclist = macs, nmacs = lenof(macs);
3561 * Construct and send our key exchange packet.
3563 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3564 for (i = 0; i < 16; i++)
3565 ssh2_pkt_addbyte((unsigned char) random_byte());
3566 /* List key exchange algorithms. */
3567 ssh2_pkt_addstring_start();
3568 for (i = 0; i < lenof(kex_algs); i++) {
3569 ssh2_pkt_addstring_str(kex_algs[i]->name);
3570 if (i < lenof(kex_algs) - 1)
3571 ssh2_pkt_addstring_str(",");
3573 /* List server host key algorithms. */
3574 ssh2_pkt_addstring_start();
3575 for (i = 0; i < lenof(hostkey_algs); i++) {
3576 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3577 if (i < lenof(hostkey_algs) - 1)
3578 ssh2_pkt_addstring_str(",");
3580 /* List client->server encryption algorithms. */
3581 ssh2_pkt_addstring_start();
3582 cipherstr_started = 0;
3583 for (i = 0; i < n_preferred_ciphers; i++) {
3584 const struct ssh2_ciphers *c = preferred_ciphers[i];
3585 if (!c) continue; /* warning flag */
3586 for (j = 0; j < c->nciphers; j++) {
3587 if (cipherstr_started)
3588 ssh2_pkt_addstring_str(",");
3589 ssh2_pkt_addstring_str(c->list[j]->name);
3590 cipherstr_started = 1;
3593 /* List server->client encryption algorithms. */
3594 ssh2_pkt_addstring_start();
3595 cipherstr_started = 0;
3596 for (i = 0; i < n_preferred_ciphers; i++) {
3597 const struct ssh2_ciphers *c = preferred_ciphers[i];
3598 if (!c) continue; /* warning flag */
3599 for (j = 0; j < c->nciphers; j++) {
3600 if (cipherstr_started)
3601 ssh2_pkt_addstring_str(",");
3602 ssh2_pkt_addstring_str(c->list[j]->name);
3603 cipherstr_started = 1;
3606 /* List client->server MAC algorithms. */
3607 ssh2_pkt_addstring_start();
3608 for (i = 0; i < nmacs; i++) {
3609 ssh2_pkt_addstring_str(maclist[i]->name);
3611 ssh2_pkt_addstring_str(",");
3613 /* List server->client MAC algorithms. */
3614 ssh2_pkt_addstring_start();
3615 for (i = 0; i < nmacs; i++) {
3616 ssh2_pkt_addstring_str(maclist[i]->name);
3618 ssh2_pkt_addstring_str(",");
3620 /* List client->server compression algorithms. */
3621 ssh2_pkt_addstring_start();
3622 for (i = 0; i < lenof(compressions) + 1; i++) {
3623 const struct ssh_compress *c =
3624 i == 0 ? preferred_comp : compressions[i - 1];
3625 ssh2_pkt_addstring_str(c->name);
3626 if (i < lenof(compressions))
3627 ssh2_pkt_addstring_str(",");
3629 /* List server->client compression algorithms. */
3630 ssh2_pkt_addstring_start();
3631 for (i = 0; i < lenof(compressions) + 1; i++) {
3632 const struct ssh_compress *c =
3633 i == 0 ? preferred_comp : compressions[i - 1];
3634 ssh2_pkt_addstring_str(c->name);
3635 if (i < lenof(compressions))
3636 ssh2_pkt_addstring_str(",");
3638 /* List client->server languages. Empty list. */
3639 ssh2_pkt_addstring_start();
3640 /* List server->client languages. Empty list. */
3641 ssh2_pkt_addstring_start();
3642 /* First KEX packet does _not_ follow, because we're not that brave. */
3643 ssh2_pkt_addbool(FALSE);
3645 ssh2_pkt_adduint32(0);
3647 exhash = exhashbase;
3648 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3654 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3657 * Now examine the other side's KEXINIT to see what we're up
3660 if (pktin.type != SSH2_MSG_KEXINIT) {
3661 bombout(("expected key exchange packet from server"));
3666 cscipher_tobe = NULL;
3667 sccipher_tobe = NULL;
3672 pktin.savedpos += 16; /* skip garbage cookie */
3673 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3674 for (i = 0; i < lenof(kex_algs); i++) {
3675 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3680 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3681 for (i = 0; i < lenof(hostkey_algs); i++) {
3682 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3683 hostkey = hostkey_algs[i];
3687 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3689 for (i = 0; i < n_preferred_ciphers; i++) {
3690 const struct ssh2_ciphers *c = preferred_ciphers[i];
3694 for (j = 0; j < c->nciphers; j++) {
3695 if (in_commasep_string(c->list[j]->name, str, len)) {
3696 cscipher_tobe = c->list[j];
3701 if (cscipher_tobe) {
3703 askcipher(cscipher_tobe->name, 1);
3707 if (!cscipher_tobe) {
3708 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3712 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3714 for (i = 0; i < n_preferred_ciphers; i++) {
3715 const struct ssh2_ciphers *c = preferred_ciphers[i];
3719 for (j = 0; j < c->nciphers; j++) {
3720 if (in_commasep_string(c->list[j]->name, str, len)) {
3721 sccipher_tobe = c->list[j];
3726 if (sccipher_tobe) {
3728 askcipher(sccipher_tobe->name, 2);
3732 if (!sccipher_tobe) {
3733 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3737 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3738 for (i = 0; i < nmacs; i++) {
3739 if (in_commasep_string(maclist[i]->name, str, len)) {
3740 csmac_tobe = maclist[i];
3744 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3745 for (i = 0; i < nmacs; i++) {
3746 if (in_commasep_string(maclist[i]->name, str, len)) {
3747 scmac_tobe = maclist[i];
3751 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3752 for (i = 0; i < lenof(compressions) + 1; i++) {
3753 const struct ssh_compress *c =
3754 i == 0 ? preferred_comp : compressions[i - 1];
3755 if (in_commasep_string(c->name, str, len)) {
3760 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3761 for (i = 0; i < lenof(compressions) + 1; i++) {
3762 const struct ssh_compress *c =
3763 i == 0 ? preferred_comp : compressions[i - 1];
3764 if (in_commasep_string(c->name, str, len)) {
3771 * Work out the number of bits of key we will need from the key
3772 * exchange. We start with the maximum key length of either
3778 csbits = cscipher_tobe->keylen;
3779 scbits = sccipher_tobe->keylen;
3780 nbits = (csbits > scbits ? csbits : scbits);
3782 /* The keys only have 160-bit entropy, since they're based on
3783 * a SHA-1 hash. So cap the key size at 160 bits. */
3788 * If we're doing Diffie-Hellman group exchange, start by
3789 * requesting a group.
3791 if (kex == &ssh_diffiehellman_gex) {
3792 logevent("Doing Diffie-Hellman group exchange");
3793 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
3795 * Work out how big a DH group we will need to allow that
3798 pbits = 512 << ((nbits - 1) / 64);
3799 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3800 ssh2_pkt_adduint32(pbits);
3804 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3805 bombout(("expected key exchange group packet from server"));
3808 p = ssh2_pkt_getmp();
3809 g = ssh2_pkt_getmp();
3810 dh_setup_group(p, g);
3811 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3812 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3814 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3816 kex_init_value = SSH2_MSG_KEXDH_INIT;
3817 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3820 logevent("Doing Diffie-Hellman key exchange");
3822 * Now generate and send e for Diffie-Hellman.
3824 e = dh_create_e(nbits * 2);
3825 ssh2_pkt_init(kex_init_value);
3830 if (pktin.type != kex_reply_value) {
3831 bombout(("expected key exchange reply packet from server"));
3834 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3835 f = ssh2_pkt_getmp();
3836 ssh2_pkt_getstring(&sigdata, &siglen);
3840 sha_string(&exhash, hostkeydata, hostkeylen);
3841 if (kex == &ssh_diffiehellman_gex) {
3842 sha_uint32(&exhash, pbits);
3843 sha_mpint(&exhash, p);
3844 sha_mpint(&exhash, g);
3846 sha_mpint(&exhash, e);
3847 sha_mpint(&exhash, f);
3848 sha_mpint(&exhash, K);
3849 SHA_Final(&exhash, exchange_hash);
3854 debug(("Exchange hash is:\n"));
3855 dmemdump(exchange_hash, 20);
3858 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3860 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3861 bombout(("Server's host key did not match the signature supplied"));
3866 * Authenticate remote host: verify host key. (We've already
3867 * checked the signature of the exchange hash.)
3869 keystr = hostkey->fmtkey(hkey);
3870 fingerprint = hostkey->fingerprint(hkey);
3871 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3872 keystr, fingerprint);
3873 if (first_kex) { /* don't bother logging this in rekeys */
3874 logevent("Host key fingerprint is:");
3875 logevent(fingerprint);
3879 hostkey->freekey(hkey);
3882 * Send SSH2_MSG_NEWKEYS.
3884 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3888 * Expect SSH2_MSG_NEWKEYS from server.
3891 if (pktin.type != SSH2_MSG_NEWKEYS) {
3892 bombout(("expected new-keys packet from server"));
3897 * Create and initialise session keys.
3899 cscipher = cscipher_tobe;
3900 sccipher = sccipher_tobe;
3903 cscomp = cscomp_tobe;
3904 sccomp = sccomp_tobe;
3905 cscomp->compress_init();
3906 sccomp->decompress_init();
3908 * Set IVs after keys. Here we use the exchange hash from the
3909 * _first_ key exchange.
3912 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3913 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3914 cscipher->setcskey(keyspace);
3915 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3916 sccipher->setsckey(keyspace);
3917 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3918 cscipher->setcsiv(keyspace);
3919 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3920 sccipher->setsciv(keyspace);
3921 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3922 csmac->setcskey(keyspace);
3923 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3924 scmac->setsckey(keyspace);
3927 * If this is the first key exchange phase, we must pass the
3928 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3929 * wants to see it but because it will need time to initialise
3930 * itself before it sees an actual packet. In subsequent key
3931 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3932 * it would only confuse the layer above.
3940 * Now we're encrypting. Begin returning 1 to the protocol main
3941 * function so that other things can run on top of the
3942 * transport. If we ever see a KEXINIT, we must go back to the
3945 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3948 logevent("Server initiated key re-exchange");
3949 goto begin_key_exchange;
3955 * Add data to an SSH2 channel output buffer.
3957 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3960 bufchain_add(&c->v.v2.outbuffer, buf, len);
3964 * Attempt to send data on an SSH2 channel.
3966 static int ssh2_try_send(struct ssh_channel *c)
3968 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3971 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3972 if ((unsigned)len > c->v.v2.remwindow)
3973 len = c->v.v2.remwindow;
3974 if ((unsigned)len > c->v.v2.remmaxpkt)
3975 len = c->v.v2.remmaxpkt;
3976 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3977 ssh2_pkt_adduint32(c->remoteid);
3978 ssh2_pkt_addstring_start();
3979 ssh2_pkt_addstring_data(data, len);
3981 bufchain_consume(&c->v.v2.outbuffer, len);
3982 c->v.v2.remwindow -= len;
3986 * After having sent as much data as we can, return the amount
3989 return bufchain_size(&c->v.v2.outbuffer);
3993 * Potentially enlarge the window on an SSH2 channel.
3995 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3998 * Never send WINDOW_ADJUST for a channel that the remote side
3999 * already thinks it's closed; there's no point, since it won't
4000 * be sending any more data anyway.
4005 if (newwin > c->v.v2.locwindow) {
4006 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4007 ssh2_pkt_adduint32(c->remoteid);
4008 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4010 c->v.v2.locwindow = newwin;
4015 * Handle the SSH2 userauth and connection layers.
4017 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4020 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4022 AUTH_KEYBOARD_INTERACTIVE
4026 AUTH_TYPE_PUBLICKEY,
4027 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4028 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4030 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4031 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4033 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4034 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
4035 static int kbd_inter_running;
4036 static int we_are_in;
4037 static int num_prompts, echo;
4038 static char username[100];
4039 static int got_username;
4040 static char pwprompt[200];
4041 static char password[100];
4042 static void *publickey_blob;
4043 static int publickey_bloblen;
4048 * Request userauth protocol, and await a response to it.
4050 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4051 ssh2_pkt_addstring("ssh-userauth");
4053 crWaitUntilV(ispkt);
4054 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4055 bombout(("Server refused user authentication protocol"));
4060 * We repeat this whole loop, including the username prompt,
4061 * until we manage a successful authentication. If the user
4062 * types the wrong _password_, they are sent back to the
4063 * beginning to try another username. (If they specify a
4064 * username in the config, they are never asked, even if they
4065 * do give a wrong password.)
4067 * I think this best serves the needs of
4069 * - the people who have no configuration, no keys, and just
4070 * want to try repeated (username,password) pairs until they
4071 * type both correctly
4073 * - people who have keys and configuration but occasionally
4074 * need to fall back to passwords
4076 * - people with a key held in Pageant, who might not have
4077 * logged in to a particular machine before; so they want to
4078 * type a username, and then _either_ their key will be
4079 * accepted, _or_ they will type a password. If they mistype
4080 * the username they will want to be able to get back and
4084 got_username = FALSE;
4093 if (got_username && !cfg.change_username) {
4095 * We got a username last time round this loop, and
4096 * with change_username turned off we don't try to get
4099 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4101 if (!ssh_get_line("login as: ",
4102 username, sizeof(username), FALSE)) {
4104 * get_line failed to get a username.
4107 logevent("No username provided. Abandoning session.");
4108 ssh_state = SSH_STATE_CLOSED;
4112 c_write_str("login as: ");
4115 crWaitUntilV(!ispkt);
4117 switch (c = *in++) {
4126 c_write_str("\b \b");
4133 c_write_str("\b \b");
4142 if (((c >= ' ' && c <= '~') ||
4143 ((unsigned char) c >= 160))
4144 && pos < sizeof(username)-1) {
4145 username[pos++] = c;
4152 c_write_str("\r\n");
4153 username[strcspn(username, "\n\r")] = '\0';
4156 strncpy(username, cfg.username, 99);
4157 username[99] = '\0';
4158 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4159 sprintf(stuff, "Using username \"%s\".\r\n", username);
4163 got_username = TRUE;
4166 * Send an authentication request using method "none": (a)
4167 * just in case it succeeds, and (b) so that we know what
4168 * authentication methods we can usefully try next.
4170 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4172 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4173 ssh2_pkt_addstring(username);
4174 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4175 ssh2_pkt_addstring("none"); /* method */
4177 type = AUTH_TYPE_NONE;
4181 tried_pubkey_config = FALSE;
4182 tried_agent = FALSE;
4183 tried_keyb_inter = FALSE;
4184 kbd_inter_running = FALSE;
4185 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4188 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4189 keytype = key_type(cfg.keyfile);
4190 if (keytype == SSH_KEYTYPE_SSH2)
4191 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4192 &publickey_bloblen);
4195 logeventf("Unable to use this key file (%s)",
4196 key_type_to_str(keytype));
4197 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4198 cfg.keyfile, key_type_to_str(keytype));
4199 c_write_str(msgbuf);
4200 publickey_blob = NULL;
4203 publickey_blob = NULL;
4207 * Wait for the result of the last authentication request.
4210 crWaitUntilV(ispkt);
4211 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4215 * Don't show the banner if we're operating in
4216 * non-verbose non-interactive mode. (It's probably
4217 * a script, which means nobody will read the
4218 * banner _anyway_, and moreover the printing of
4219 * the banner will screw up processing on the
4220 * output of (say) plink.)
4222 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4223 ssh2_pkt_getstring(&banner, &size);
4225 c_write_untrusted(banner, size);
4227 crWaitUntilV(ispkt);
4229 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4230 logevent("Access granted");
4235 if (kbd_inter_running &&
4236 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4238 * This is a further prompt in keyboard-interactive
4239 * authentication. Do nothing.
4241 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4242 bombout(("Strange packet received during authentication: type %d",
4250 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4251 * we can look at the string in it and know what we can
4252 * helpfully try next.
4254 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4257 ssh2_pkt_getstring(&methods, &methlen);
4258 kbd_inter_running = FALSE;
4259 if (!ssh2_pkt_getbool()) {
4261 * We have received an unequivocal Access
4262 * Denied. This can translate to a variety of
4265 * - if we'd just tried "none" authentication,
4266 * it's not worth printing anything at all
4268 * - if we'd just tried a public key _offer_,
4269 * the message should be "Server refused our
4270 * key" (or no message at all if the key
4271 * came from Pageant)
4273 * - if we'd just tried anything else, the
4274 * message really should be "Access denied".
4276 * Additionally, if we'd just tried password
4277 * authentication, we should break out of this
4278 * whole loop so as to go back to the username
4281 if (type == AUTH_TYPE_NONE) {
4283 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4284 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4285 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4286 c_write_str("Server refused our key\r\n");
4287 logevent("Server refused public key");
4288 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4289 /* server declined keyboard-interactive; ignore */
4291 c_write_str("Access denied\r\n");
4292 logevent("Access denied");
4293 if (type == AUTH_TYPE_PASSWORD) {
4299 c_write_str("Further authentication required\r\n");
4300 logevent("Further authentication required");
4304 in_commasep_string("publickey", methods, methlen);
4306 in_commasep_string("password", methods, methlen);
4307 can_keyb_inter = cfg.try_ki_auth &&
4308 in_commasep_string("keyboard-interactive", methods, methlen);
4312 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4314 if (!method && can_pubkey && agent_exists() && !tried_agent) {
4316 * Attempt public-key authentication using Pageant.
4318 static unsigned char request[5], *response, *p;
4319 static int responselen;
4320 static int i, nkeys;
4321 static int authed = FALSE;
4324 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4328 logevent("Pageant is running. Requesting keys.");
4330 /* Request the keys held by the agent. */
4331 PUT_32BIT(request, 1);
4332 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4333 agent_query(request, 5, &r, &responselen);
4334 response = (unsigned char *) r;
4335 if (response && responselen >= 5 &&
4336 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4338 nkeys = GET_32BIT(p);
4342 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4345 for (i = 0; i < nkeys; i++) {
4346 static char *pkblob, *alg, *commentp;
4347 static int pklen, alglen, commentlen;
4348 static int siglen, retlen, len;
4349 static char *q, *agentreq, *ret;
4354 sprintf(buf, "Trying Pageant key #%d", i);
4357 pklen = GET_32BIT(p);
4359 if (publickey_blob &&
4360 pklen == publickey_bloblen &&
4361 !memcmp(p, publickey_blob, publickey_bloblen)) {
4362 logevent("This key matches configured key file");
4363 tried_pubkey_config = 1;
4367 alglen = GET_32BIT(pkblob);
4369 commentlen = GET_32BIT(p);
4373 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4374 ssh2_pkt_addstring(username);
4375 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4376 ssh2_pkt_addstring("publickey"); /* method */
4377 ssh2_pkt_addbool(FALSE); /* no signature included */
4378 ssh2_pkt_addstring_start();
4379 ssh2_pkt_addstring_data(alg, alglen);
4380 ssh2_pkt_addstring_start();
4381 ssh2_pkt_addstring_data(pkblob, pklen);
4384 crWaitUntilV(ispkt);
4385 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4386 logevent("Key refused");
4390 if (flags & FLAG_VERBOSE) {
4392 ("Authenticating with public key \"");
4393 c_write(commentp, commentlen);
4394 c_write_str("\" from agent\r\n");
4398 * Server is willing to accept the key.
4399 * Construct a SIGN_REQUEST.
4401 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4402 ssh2_pkt_addstring(username);
4403 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4404 ssh2_pkt_addstring("publickey"); /* method */
4405 ssh2_pkt_addbool(TRUE);
4406 ssh2_pkt_addstring_start();
4407 ssh2_pkt_addstring_data(alg, alglen);
4408 ssh2_pkt_addstring_start();
4409 ssh2_pkt_addstring_data(pkblob, pklen);
4411 siglen = pktout.length - 5 + 4 + 20;
4412 len = 1; /* message type */
4413 len += 4 + pklen; /* key blob */
4414 len += 4 + siglen; /* data to sign */
4415 len += 4; /* flags */
4416 agentreq = smalloc(4 + len);
4417 PUT_32BIT(agentreq, len);
4419 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4420 PUT_32BIT(q, pklen);
4422 memcpy(q, pkblob, pklen);
4424 PUT_32BIT(q, siglen);
4426 /* Now the data to be signed... */
4429 memcpy(q, ssh2_session_id, 20);
4431 memcpy(q, pktout.data + 5, pktout.length - 5);
4432 q += pktout.length - 5;
4433 /* And finally the (zero) flags word. */
4435 agent_query(agentreq, len + 4, &vret, &retlen);
4439 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4440 logevent("Sending Pageant's response");
4441 ssh2_add_sigblob(pkblob, pklen,
4442 ret + 9, GET_32BIT(ret + 5));
4448 ("Pageant failed to answer challenge");
4458 if (!method && can_pubkey && publickey_blob
4459 && !tried_pubkey_config) {
4460 unsigned char *pub_blob;
4461 char *algorithm, *comment;
4464 tried_pubkey_config = TRUE;
4466 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4469 * Try the public key supplied in the configuration.
4471 * First, offer the public blob to see if the server is
4472 * willing to accept it.
4474 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4477 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4478 ssh2_pkt_addstring(username);
4479 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4480 ssh2_pkt_addstring("publickey"); /* method */
4481 ssh2_pkt_addbool(FALSE); /* no signature included */
4482 ssh2_pkt_addstring(algorithm);
4483 ssh2_pkt_addstring_start();
4484 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4486 logevent("Offered public key"); /* FIXME */
4488 crWaitUntilV(ispkt);
4489 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4491 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4492 continue; /* key refused; give up on it */
4495 logevent("Offer of public key accepted");
4497 * Actually attempt a serious authentication using
4500 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4502 "Passphrase for key \"%.100s\": ",
4508 c_write_str("Authenticating with public key \"");
4509 c_write_str(comment);
4510 c_write_str("\"\r\n");
4511 method = AUTH_PUBLICKEY_FILE;
4515 if (!method && can_keyb_inter && !tried_keyb_inter) {
4516 method = AUTH_KEYBOARD_INTERACTIVE;
4517 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4518 tried_keyb_inter = TRUE;
4520 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4522 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4523 ssh2_pkt_addstring(username);
4524 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4525 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4526 ssh2_pkt_addstring(""); /* lang */
4527 ssh2_pkt_addstring("");
4530 crWaitUntilV(ispkt);
4531 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4532 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4534 logevent("Keyboard-interactive authentication refused");
4535 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4539 kbd_inter_running = TRUE;
4542 if (kbd_inter_running) {
4543 method = AUTH_KEYBOARD_INTERACTIVE;
4544 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4545 tried_keyb_inter = TRUE;
4547 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4549 /* We've got packet with that "interactive" info
4550 dump banners, and set its prompt as ours */
4552 char *name, *inst, *lang, *prompt;
4553 int name_len, inst_len, lang_len, prompt_len;
4554 ssh2_pkt_getstring(&name, &name_len);
4555 ssh2_pkt_getstring(&inst, &inst_len);
4556 ssh2_pkt_getstring(&lang, &lang_len);
4558 c_write_untrusted(name, name_len);
4560 c_write_untrusted(inst, inst_len);
4561 num_prompts = ssh2_pkt_getuint32();
4563 ssh2_pkt_getstring(&prompt, &prompt_len);
4564 strncpy(pwprompt, prompt, sizeof(pwprompt));
4565 pwprompt[prompt_len < sizeof(pwprompt) ?
4566 prompt_len : sizeof(pwprompt)-1] = '\0';
4569 echo = ssh2_pkt_getbool();
4573 if (!method && can_passwd) {
4574 method = AUTH_PASSWORD;
4575 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4576 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4583 if (!ssh_get_line(pwprompt, password,
4584 sizeof(password), TRUE)) {
4586 * get_line failed to get a password (for
4587 * example because one was supplied on the
4588 * command line which has already failed to
4591 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4592 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4594 ("No more passwords available to try");
4595 ssh2_pkt_addstring("en"); /* language tag */
4597 logevent("Unable to authenticate");
4598 connection_fatal("Unable to authenticate");
4599 ssh_state = SSH_STATE_CLOSED;
4606 c_write_untrusted(pwprompt, strlen(pwprompt));
4611 crWaitUntilV(!ispkt);
4613 switch (c = *in++) {
4633 if (pos < sizeof(password)-1)
4634 password[pos++] = c;
4638 c_write_str("\r\n");
4642 if (method == AUTH_PUBLICKEY_FILE) {
4644 * We have our passphrase. Now try the actual authentication.
4646 struct ssh2_userkey *key;
4648 key = ssh2_load_userkey(cfg.keyfile, password);
4649 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4650 if (key == SSH2_WRONG_PASSPHRASE) {
4651 c_write_str("Wrong passphrase\r\n");
4652 tried_pubkey_config = FALSE;
4654 c_write_str("Unable to load private key\r\n");
4655 tried_pubkey_config = TRUE;
4657 /* Send a spurious AUTH_NONE to return to the top. */
4658 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4659 ssh2_pkt_addstring(username);
4660 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4661 ssh2_pkt_addstring("none"); /* method */
4663 type = AUTH_TYPE_NONE;
4665 unsigned char *pkblob, *sigblob, *sigdata;
4666 int pkblob_len, sigblob_len, sigdata_len;
4669 * We have loaded the private key and the server
4670 * has announced that it's willing to accept it.
4671 * Hallelujah. Generate a signature and send it.
4673 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4674 ssh2_pkt_addstring(username);
4675 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4676 ssh2_pkt_addstring("publickey"); /* method */
4677 ssh2_pkt_addbool(TRUE);
4678 ssh2_pkt_addstring(key->alg->name);
4679 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4680 ssh2_pkt_addstring_start();
4681 ssh2_pkt_addstring_data(pkblob, pkblob_len);
4684 * The data to be signed is:
4688 * followed by everything so far placed in the
4691 sigdata_len = pktout.length - 5 + 4 + 20;
4692 sigdata = smalloc(sigdata_len);
4693 PUT_32BIT(sigdata, 20);
4694 memcpy(sigdata + 4, ssh2_session_id, 20);
4695 memcpy(sigdata + 24, pktout.data + 5,
4697 sigblob = key->alg->sign(key->data, sigdata,
4698 sigdata_len, &sigblob_len);
4699 ssh2_add_sigblob(pkblob, pkblob_len,
4700 sigblob, sigblob_len);
4706 type = AUTH_TYPE_PUBLICKEY;
4708 } else if (method == AUTH_PASSWORD) {
4710 * We send the password packet lumped tightly together with
4711 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4712 * string long enough to make the total length of the two
4713 * packets constant. This should ensure that a passive
4714 * listener doing traffic analyis can't work out the length
4717 * For this to work, we need an assumption about the
4718 * maximum length of the password packet. I think 256 is
4719 * pretty conservative. Anyone using a password longer than
4720 * that probably doesn't have much to worry about from
4721 * people who find out how long their password is!
4723 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4724 ssh2_pkt_addstring(username);
4725 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4726 ssh2_pkt_addstring("password");
4727 ssh2_pkt_addbool(FALSE);
4728 ssh2_pkt_addstring(password);
4731 * We'll include a string that's an exact multiple of the
4732 * cipher block size. If the cipher is NULL for some
4733 * reason, we don't do this trick at all because we gain
4739 stringlen = (256 - deferred_len);
4740 stringlen += cscipher->blksize - 1;
4741 stringlen -= (stringlen % cscipher->blksize);
4744 * Temporarily disable actual compression,
4745 * so we can guarantee to get this string
4746 * exactly the length we want it. The
4747 * compression-disabling routine should
4748 * return an integer indicating how many
4749 * bytes we should adjust our string length
4752 stringlen -= cscomp->disable_compression();
4754 ssh2_pkt_init(SSH2_MSG_IGNORE);
4755 ssh2_pkt_addstring_start();
4756 for (i = 0; i < stringlen; i++) {
4757 char c = (char) random_byte();
4758 ssh2_pkt_addstring_data(&c, 1);
4762 ssh_pkt_defersend();
4763 logevent("Sent password");
4764 type = AUTH_TYPE_PASSWORD;
4765 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4766 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4767 ssh2_pkt_adduint32(num_prompts);
4768 ssh2_pkt_addstring(password);
4769 memset(password, 0, sizeof(password));
4771 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4774 ("No supported authentication methods left to try!\r\n");
4776 ("No supported authentications offered. Disconnecting");
4777 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4778 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4780 ("No supported authentication methods available");
4781 ssh2_pkt_addstring("en"); /* language tag */
4783 ssh_state = SSH_STATE_CLOSED;
4787 } while (!we_are_in);
4790 * Now we're authenticated for the connection protocol. The
4791 * connection protocol will automatically have started at this
4792 * point; there's no need to send SERVICE_REQUEST.
4796 * So now create a channel with a session in it.
4798 ssh_channels = newtree234(ssh_channelcmp);
4799 mainchan = smalloc(sizeof(struct ssh_channel));
4800 mainchan->localid = alloc_channel_id();
4801 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4802 ssh2_pkt_addstring("session");
4803 ssh2_pkt_adduint32(mainchan->localid);
4804 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4805 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4806 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4808 crWaitUntilV(ispkt);
4809 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4810 bombout(("Server refused to open a session"));
4812 /* FIXME: error data comes back in FAILURE packet */
4814 if (ssh2_pkt_getuint32() != mainchan->localid) {
4815 bombout(("Server's channel confirmation cited wrong channel"));
4818 mainchan->remoteid = ssh2_pkt_getuint32();
4819 mainchan->type = CHAN_MAINSESSION;
4820 mainchan->closes = 0;
4821 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4822 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4823 bufchain_init(&mainchan->v.v2.outbuffer);
4824 add234(ssh_channels, mainchan);
4825 logevent("Opened channel for session");
4828 * Potentially enable X11 forwarding.
4830 if (cfg.x11_forward) {
4831 char proto[20], data[64];
4832 logevent("Requesting X11 forwarding");
4833 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4834 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4835 ssh2_pkt_adduint32(mainchan->remoteid);
4836 ssh2_pkt_addstring("x11-req");
4837 ssh2_pkt_addbool(1); /* want reply */
4838 ssh2_pkt_addbool(0); /* many connections */
4839 ssh2_pkt_addstring(proto);
4840 ssh2_pkt_addstring(data);
4841 ssh2_pkt_adduint32(0); /* screen number */
4845 crWaitUntilV(ispkt);
4846 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4847 unsigned i = ssh2_pkt_getuint32();
4848 struct ssh_channel *c;
4849 c = find234(ssh_channels, &i, ssh_channelfind);
4851 continue; /* nonexistent channel */
4852 c->v.v2.remwindow += ssh2_pkt_getuint32();
4854 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4856 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4857 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4858 bombout(("Unexpected response to X11 forwarding request:"
4859 " packet type %d", pktin.type));
4862 logevent("X11 forwarding refused");
4864 logevent("X11 forwarding enabled");
4865 ssh_X11_fwd_enabled = TRUE;
4870 * Enable port forwardings.
4873 static char *e; /* preserve across crReturn */
4876 int sport,dport,sserv,dserv;
4877 char sports[256], dports[256], host[256];
4881 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4882 /* Add port forwardings. */
4887 while (*e && *e != '\t')
4893 while (*e && *e != ':')
4903 dport = atoi(dports);
4907 se = getservbyname(dports, NULL);
4909 dport = ntohs(se->s_port);
4912 "Service lookup failed for destination port \"%s\"",
4917 sport = atoi(sports);
4921 se = getservbyname(sports, NULL);
4923 sport = ntohs(se->s_port);
4926 "Service lookup failed for source port \"%s\"",
4931 if (sport && dport) {
4933 pfd_addforward(host, dport, sport);
4934 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
4935 " %s:%.*s%.*s%d%.*s",
4936 sserv ? strlen(sports) : 0, sports,
4937 sserv, "(", sport, sserv, ")",
4939 dserv ? strlen(dports) : 0, dports,
4940 dserv, "(", dport, dserv, ")");
4943 struct ssh_rportfwd *pf;
4944 pf = smalloc(sizeof(*pf));
4945 strcpy(pf->dhost, host);
4948 if (add234(ssh_rportfwds, pf) != pf) {
4950 "Duplicate remote port forwarding to %s:%d",
4955 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
4956 " forward to %s:%.*s%.*s%d%.*s",
4957 sserv ? strlen(sports) : 0, sports,
4958 sserv, "(", sport, sserv, ")",
4960 dserv ? strlen(dports) : 0, dports,
4961 dserv, "(", dport, dserv, ")");
4963 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
4964 ssh2_pkt_addstring("tcpip-forward");
4965 ssh2_pkt_addbool(1);/* want reply */
4966 if (cfg.rport_acceptall)
4967 ssh2_pkt_addstring("0.0.0.0");
4969 ssh2_pkt_addstring("127.0.0.1");
4970 ssh2_pkt_adduint32(sport);
4974 crWaitUntilV(ispkt);
4975 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4976 unsigned i = ssh2_pkt_getuint32();
4977 struct ssh_channel *c;
4978 c = find234(ssh_channels, &i, ssh_channelfind);
4980 continue;/* nonexistent channel */
4981 c->v.v2.remwindow += ssh2_pkt_getuint32();
4983 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4985 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
4986 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
4987 bombout(("Unexpected response to port "
4988 "forwarding request: packet type %d",
4992 logevent("Server refused this port forwarding");
4994 logevent("Remote port forwarding enabled");
5003 * Potentially enable agent forwarding.
5005 if (cfg.agentfwd && agent_exists()) {
5006 logevent("Requesting OpenSSH-style agent forwarding");
5007 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5008 ssh2_pkt_adduint32(mainchan->remoteid);
5009 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5010 ssh2_pkt_addbool(1); /* want reply */
5014 crWaitUntilV(ispkt);
5015 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5016 unsigned i = ssh2_pkt_getuint32();
5017 struct ssh_channel *c;
5018 c = find234(ssh_channels, &i, ssh_channelfind);
5020 continue; /* nonexistent channel */
5021 c->v.v2.remwindow += ssh2_pkt_getuint32();
5023 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5025 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5026 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5027 bombout(("Unexpected response to agent forwarding request:"
5028 " packet type %d", pktin.type));
5031 logevent("Agent forwarding refused");
5033 logevent("Agent forwarding enabled");
5034 ssh_agentfwd_enabled = TRUE;
5039 * Now allocate a pty for the session.
5042 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5043 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5044 ssh2_pkt_addstring("pty-req");
5045 ssh2_pkt_addbool(1); /* want reply */
5046 ssh2_pkt_addstring(cfg.termtype);
5047 ssh2_pkt_adduint32(cols);
5048 ssh2_pkt_adduint32(rows);
5049 ssh2_pkt_adduint32(0); /* pixel width */
5050 ssh2_pkt_adduint32(0); /* pixel height */
5051 ssh2_pkt_addstring_start();
5052 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5054 ssh_state = SSH_STATE_INTERMED;
5057 crWaitUntilV(ispkt);
5058 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5059 unsigned i = ssh2_pkt_getuint32();
5060 struct ssh_channel *c;
5061 c = find234(ssh_channels, &i, ssh_channelfind);
5063 continue; /* nonexistent channel */
5064 c->v.v2.remwindow += ssh2_pkt_getuint32();
5066 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5068 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5069 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5070 bombout(("Unexpected response to pty request:"
5071 " packet type %d", pktin.type));
5074 c_write_str("Server refused to allocate pty\r\n");
5075 ssh_editing = ssh_echoing = 1;
5077 logevent("Allocated pty");
5080 ssh_editing = ssh_echoing = 1;
5084 * Start a shell or a remote command. We may have to attempt
5085 * this twice if the config data has provided a second choice
5092 if (ssh_fallback_cmd) {
5093 subsys = cfg.ssh_subsys2;
5094 cmd = cfg.remote_cmd_ptr2;
5096 subsys = cfg.ssh_subsys;
5097 cmd = cfg.remote_cmd_ptr;
5100 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5101 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5103 ssh2_pkt_addstring("subsystem");
5104 ssh2_pkt_addbool(1); /* want reply */
5105 ssh2_pkt_addstring(cmd);
5107 ssh2_pkt_addstring("exec");
5108 ssh2_pkt_addbool(1); /* want reply */
5109 ssh2_pkt_addstring(cmd);
5111 ssh2_pkt_addstring("shell");
5112 ssh2_pkt_addbool(1); /* want reply */
5116 crWaitUntilV(ispkt);
5117 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5118 unsigned i = ssh2_pkt_getuint32();
5119 struct ssh_channel *c;
5120 c = find234(ssh_channels, &i, ssh_channelfind);
5122 continue; /* nonexistent channel */
5123 c->v.v2.remwindow += ssh2_pkt_getuint32();
5125 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5126 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5127 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5128 bombout(("Unexpected response to shell/command request:"
5129 " packet type %d", pktin.type));
5133 * We failed to start the command. If this is the
5134 * fallback command, we really are finished; if it's
5135 * not, and if the fallback command exists, try falling
5136 * back to it before complaining.
5138 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5139 logevent("Primary command failed; attempting fallback");
5140 ssh_fallback_cmd = TRUE;
5143 bombout(("Server refused to start a shell/command"));
5146 logevent("Started a shell/command");
5151 ssh_state = SSH_STATE_SESSION;
5155 ssh_special(TS_EOF);
5160 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
5163 static int try_send;
5167 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
5168 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5171 unsigned i = ssh2_pkt_getuint32();
5172 struct ssh_channel *c;
5173 c = find234(ssh_channels, &i, ssh_channelfind);
5175 continue; /* nonexistent channel */
5176 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5177 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5178 continue; /* extended but not stderr */
5179 ssh2_pkt_getstring(&data, &length);
5182 c->v.v2.locwindow -= length;
5184 case CHAN_MAINSESSION:
5186 from_backend(pktin.type ==
5187 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5191 bufsize = x11_send(c->u.x11.s, data, length);
5194 bufsize = pfd_send(c->u.pfd.s, data, length);
5197 while (length > 0) {
5198 if (c->u.a.lensofar < 4) {
5199 int l = min(4 - c->u.a.lensofar, length);
5200 memcpy(c->u.a.msglen + c->u.a.lensofar,
5204 c->u.a.lensofar += l;
5206 if (c->u.a.lensofar == 4) {
5208 4 + GET_32BIT(c->u.a.msglen);
5209 c->u.a.message = smalloc(c->u.a.totallen);
5210 memcpy(c->u.a.message, c->u.a.msglen, 4);
5212 if (c->u.a.lensofar >= 4 && length > 0) {
5214 min(c->u.a.totallen - c->u.a.lensofar,
5216 memcpy(c->u.a.message + c->u.a.lensofar,
5220 c->u.a.lensofar += l;
5222 if (c->u.a.lensofar == c->u.a.totallen) {
5223 void *reply, *sentreply;
5225 agent_query(c->u.a.message,
5226 c->u.a.totallen, &reply,
5231 /* Fake SSH_AGENT_FAILURE. */
5232 sentreply = "\0\0\0\1\5";
5235 ssh2_add_channel_data(c, sentreply,
5240 sfree(c->u.a.message);
5241 c->u.a.lensofar = 0;
5248 * If we are not buffering too much data,
5249 * enlarge the window again at the remote side.
5251 if (bufsize < OUR_V2_WINSIZE)
5252 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5254 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
5255 ssh_state = SSH_STATE_CLOSED;
5256 logevent("Received disconnect message");
5258 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
5259 unsigned i = ssh2_pkt_getuint32();
5260 struct ssh_channel *c;
5262 c = find234(ssh_channels, &i, ssh_channelfind);
5264 continue; /* nonexistent channel */
5266 if (c->type == CHAN_X11) {
5268 * Remote EOF on an X11 channel means we should
5269 * wrap up and close the channel ourselves.
5271 x11_close(c->u.x11.s);
5273 } else if (c->type == CHAN_AGENT) {
5275 } else if (c->type == CHAN_SOCKDATA) {
5276 pfd_close(c->u.pfd.s);
5279 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5280 unsigned i = ssh2_pkt_getuint32();
5281 struct ssh_channel *c;
5283 c = find234(ssh_channels, &i, ssh_channelfind);
5285 continue; /* nonexistent channel */
5286 /* Do pre-close processing on the channel. */
5288 case CHAN_MAINSESSION:
5289 break; /* nothing to see here, move along */
5291 if (c->u.x11.s != NULL)
5292 x11_close(c->u.x11.s);
5299 if (c->u.pfd.s != NULL)
5300 pfd_close(c->u.pfd.s);
5304 if (c->closes == 0) {
5305 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5306 ssh2_pkt_adduint32(c->remoteid);
5309 del234(ssh_channels, c);
5310 bufchain_clear(&c->v.v2.outbuffer);
5314 * See if that was the last channel left open.
5316 if (count234(ssh_channels) == 0) {
5319 * We used to send SSH_MSG_DISCONNECT here,
5320 * because I'd believed that _every_ conforming
5321 * SSH2 connection had to end with a disconnect
5322 * being sent by at least one side; apparently
5323 * I was wrong and it's perfectly OK to
5324 * unceremoniously slam the connection shut
5325 * when you're done, and indeed OpenSSH feels
5326 * this is more polite than sending a
5327 * DISCONNECT. So now we don't.
5329 logevent("All channels closed. Disconnecting");
5330 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5331 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5332 ssh2_pkt_addstring("All open channels closed");
5333 ssh2_pkt_addstring("en"); /* language tag */
5336 ssh_state = SSH_STATE_CLOSED;
5339 continue; /* remote sends close; ignore (FIXME) */
5340 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5341 unsigned i = ssh2_pkt_getuint32();
5342 struct ssh_channel *c;
5343 c = find234(ssh_channels, &i, ssh_channelfind);
5345 continue; /* nonexistent channel */
5346 c->v.v2.remwindow += ssh2_pkt_getuint32();
5348 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5349 unsigned i = ssh2_pkt_getuint32();
5350 struct ssh_channel *c;
5351 c = find234(ssh_channels, &i, ssh_channelfind);
5353 continue; /* nonexistent channel */
5354 if (c->type != CHAN_SOCKDATA_DORMANT)
5355 continue; /* dunno why they're confirming this */
5356 c->remoteid = ssh2_pkt_getuint32();
5357 c->type = CHAN_SOCKDATA;
5358 c->v.v2.remwindow = ssh2_pkt_getuint32();
5359 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5360 bufchain_init(&c->v.v2.outbuffer);
5362 pfd_confirm(c->u.pfd.s);
5365 * We have a pending close on this channel,
5366 * which we decided on before the server acked
5367 * the channel open. So now we know the
5368 * remoteid, we can close it again.
5370 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5371 ssh2_pkt_adduint32(c->remoteid);
5374 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5375 unsigned i = ssh2_pkt_getuint32();
5376 struct ssh_channel *c;
5377 c = find234(ssh_channels, &i, ssh_channelfind);
5379 continue; /* nonexistent channel */
5380 if (c->type != CHAN_SOCKDATA_DORMANT)
5381 continue; /* dunno why they're failing this */
5383 logevent("Forwarded connection refused by server");
5385 pfd_close(c->u.pfd.s);
5387 del234(ssh_channels, c);
5389 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5392 int typelen, want_reply;
5393 struct ssh_channel *c;
5395 localid = ssh2_pkt_getuint32();
5396 ssh2_pkt_getstring(&type, &typelen);
5397 want_reply = ssh2_pkt_getbool();
5400 * First, check that the channel exists. Otherwise,
5401 * we can instantly disconnect with a rude message.
5403 c = find234(ssh_channels, &localid, ssh_channelfind);
5406 sprintf(buf, "Received channel request for nonexistent"
5407 " channel %d", localid);
5409 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5410 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5411 ssh2_pkt_addstring(buf);
5412 ssh2_pkt_addstring("en"); /* language tag */
5414 connection_fatal("%s", buf);
5415 ssh_state = SSH_STATE_CLOSED;
5420 * Having got the channel number, we now look at
5421 * the request type string to see if it's something
5424 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5426 /* We recognise "exit-status" on the primary channel. */
5428 ssh_exitcode = ssh2_pkt_getuint32();
5429 sprintf(buf, "Server sent command exit status %d",
5433 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5434 ssh2_pkt_adduint32(c->remoteid);
5439 * This is a channel request we don't know
5440 * about, so we now either ignore the request
5441 * or respond with CHANNEL_FAILURE, depending
5445 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5446 ssh2_pkt_adduint32(c->remoteid);
5450 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5452 int typelen, want_reply;
5454 ssh2_pkt_getstring(&type, &typelen);
5455 want_reply = ssh2_pkt_getbool();
5458 * We currently don't support any global requests
5459 * at all, so we either ignore the request or
5460 * respond with REQUEST_FAILURE, depending on
5464 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5467 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5471 struct ssh_channel *c;
5472 unsigned remid, winsize, pktsize;
5473 ssh2_pkt_getstring(&type, &typelen);
5474 c = smalloc(sizeof(struct ssh_channel));
5476 remid = ssh2_pkt_getuint32();
5477 winsize = ssh2_pkt_getuint32();
5478 pktsize = ssh2_pkt_getuint32();
5480 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5481 if (!ssh_X11_fwd_enabled)
5482 error = "X11 forwarding is not enabled";
5483 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5485 error = "Unable to open an X11 connection";
5489 } else if (typelen == 15 &&
5490 !memcmp(type, "forwarded-tcpip", 15)) {
5491 struct ssh_rportfwd pf, *realpf;
5494 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5495 pf.sport = ssh2_pkt_getuint32();
5496 realpf = find234(ssh_rportfwds, &pf, NULL);
5497 if (realpf == NULL) {
5498 error = "Remote port is not recognised";
5500 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5503 sprintf(buf, "Received remote port open request for %s:%d",
5504 realpf->dhost, realpf->dport);
5507 sprintf(buf, "Port open failed: %s", e);
5509 error = "Port open failed";
5511 logevent("Forwarded port opened successfully");
5512 c->type = CHAN_SOCKDATA;
5515 } else if (typelen == 22 &&
5516 !memcmp(type, "auth-agent@openssh.com", 3)) {
5517 if (!ssh_agentfwd_enabled)
5518 error = "Agent forwarding is not enabled";
5520 c->type = CHAN_AGENT; /* identify channel type */
5521 c->u.a.lensofar = 0;
5524 error = "Unsupported channel type requested";
5527 c->remoteid = remid;
5529 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5530 ssh2_pkt_adduint32(c->remoteid);
5531 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5532 ssh2_pkt_addstring(error);
5533 ssh2_pkt_addstring("en"); /* language tag */
5537 c->localid = alloc_channel_id();
5539 c->v.v2.locwindow = OUR_V2_WINSIZE;
5540 c->v.v2.remwindow = winsize;
5541 c->v.v2.remmaxpkt = pktsize;
5542 bufchain_init(&c->v.v2.outbuffer);
5543 add234(ssh_channels, c);
5544 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5545 ssh2_pkt_adduint32(c->remoteid);
5546 ssh2_pkt_adduint32(c->localid);
5547 ssh2_pkt_adduint32(c->v.v2.locwindow);
5548 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5552 bombout(("Strange packet received: type %d", pktin.type));
5557 * We have spare data. Add it to the channel buffer.
5559 ssh2_add_channel_data(mainchan, in, inlen);
5564 struct ssh_channel *c;
5566 * Try to send data on all channels if we can.
5568 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5569 int bufsize = ssh2_try_send(c);
5572 case CHAN_MAINSESSION:
5573 /* stdin need not receive an unthrottle
5574 * notification since it will be polled */
5577 x11_unthrottle(c->u.x11.s);
5580 /* agent sockets are request/response and need no
5581 * buffer management */
5584 pfd_unthrottle(c->u.pfd.s);
5596 * Handle the top-level SSH2 protocol.
5598 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5600 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5602 do_ssh2_authconn(in, inlen, ispkt);
5606 * Called to set up the connection.
5608 * Returns an error message, or NULL on success.
5610 static char *ssh_init(char *host, int port, char **realhost, int nodelay)
5615 if (crypto_startup() == 0)
5616 return "Microsoft high encryption pack not installed!";
5622 ssh1_throttle_count = 0;
5623 ssh_overall_bufsize = 0;
5624 ssh_fallback_cmd = 0;
5626 p = connect_to_host(host, port, realhost, nodelay);
5634 * Called to send data down the Telnet connection.
5636 static int ssh_send(char *buf, int len)
5638 if (s == NULL || ssh_protocol == NULL)
5641 ssh_protocol(buf, len, 0);
5643 return ssh_sendbuffer();
5647 * Called to query the current amount of buffered stdin data.
5649 static int ssh_sendbuffer(void)
5653 if (s == NULL || ssh_protocol == NULL)
5657 * If the SSH socket itself has backed up, add the total backup
5658 * size on that to any individual buffer on the stdin channel.
5661 if (ssh_throttled_all)
5662 override_value = ssh_overall_bufsize;
5664 if (ssh_version == 1) {
5665 return override_value;
5666 } else if (ssh_version == 2) {
5667 if (!mainchan || mainchan->closes > 0)
5668 return override_value;
5670 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5677 * Called to set the size of the window from SSH's POV.
5679 static void ssh_size(void)
5681 switch (ssh_state) {
5682 case SSH_STATE_BEFORE_SIZE:
5683 case SSH_STATE_PREPACKET:
5684 case SSH_STATE_CLOSED:
5685 break; /* do nothing */
5686 case SSH_STATE_INTERMED:
5687 size_needed = TRUE; /* buffer for later */
5689 case SSH_STATE_SESSION:
5691 if (ssh_version == 1) {
5692 send_packet(SSH1_CMSG_WINDOW_SIZE,
5693 PKT_INT, rows, PKT_INT, cols,
5694 PKT_INT, 0, PKT_INT, 0, PKT_END);
5696 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5697 ssh2_pkt_adduint32(mainchan->remoteid);
5698 ssh2_pkt_addstring("window-change");
5699 ssh2_pkt_addbool(0);
5700 ssh2_pkt_adduint32(cols);
5701 ssh2_pkt_adduint32(rows);
5702 ssh2_pkt_adduint32(0);
5703 ssh2_pkt_adduint32(0);
5712 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5713 * can send an EOF and collect resulting output (e.g. `plink
5716 static void ssh_special(Telnet_Special code)
5718 if (code == TS_EOF) {
5719 if (ssh_state != SSH_STATE_SESSION) {
5721 * Buffer the EOF in case we are pre-SESSION, so we can
5722 * send it as soon as we reach SESSION.
5728 if (ssh_version == 1) {
5729 send_packet(SSH1_CMSG_EOF, PKT_END);
5731 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5732 ssh2_pkt_adduint32(mainchan->remoteid);
5735 logevent("Sent EOF message");
5736 } else if (code == TS_PING) {
5737 if (ssh_state == SSH_STATE_CLOSED
5738 || ssh_state == SSH_STATE_PREPACKET) return;
5739 if (ssh_version == 1) {
5740 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5742 ssh2_pkt_init(SSH2_MSG_IGNORE);
5743 ssh2_pkt_addstring_start();
5751 void *new_sock_channel(Socket s)
5753 struct ssh_channel *c;
5754 c = smalloc(sizeof(struct ssh_channel));
5757 c->remoteid = -1; /* to be set when open confirmed */
5758 c->localid = alloc_channel_id();
5760 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5762 add234(ssh_channels, c);
5768 * This is called when stdout/stderr (the entity to which
5769 * from_backend sends data) manages to clear some backlog.
5771 void ssh_unthrottle(int bufsize)
5773 if (ssh_version == 1) {
5774 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5775 ssh1_stdout_throttling = 0;
5779 if (mainchan && mainchan->closes == 0)
5780 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5784 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5786 struct ssh_channel *c = (struct ssh_channel *)channel;
5789 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5792 if (ssh_version == 1) {
5793 send_packet(SSH1_MSG_PORT_OPEN,
5794 PKT_INT, c->localid,
5797 //PKT_STR, <org:orgport>,
5800 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5801 ssh2_pkt_addstring("direct-tcpip");
5802 ssh2_pkt_adduint32(c->localid);
5803 c->v.v2.locwindow = OUR_V2_WINSIZE;
5804 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5805 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5806 ssh2_pkt_addstring(hostname);
5807 ssh2_pkt_adduint32(port);
5809 * We make up values for the originator data; partly it's
5810 * too much hassle to keep track, and partly I'm not
5811 * convinced the server should be told details like that
5812 * about my local network configuration.
5814 ssh2_pkt_addstring("client-side-connection");
5815 ssh2_pkt_adduint32(0);
5821 static Socket ssh_socket(void)
5826 static int ssh_sendok(void)
5831 static int ssh_ldisc(int option)
5833 if (option == LD_ECHO)
5835 if (option == LD_EDIT)
5840 static int ssh_return_exitcode(void)
5842 return ssh_exitcode;
5845 Backend ssh_backend = {
5852 ssh_return_exitcode,