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)
1545 if (pktin.length - pktin.savedpos < 4)
1547 *length = GET_32BIT(pktin.data + pktin.savedpos);
1548 pktin.savedpos += 4;
1549 if (pktin.length - pktin.savedpos < *length)
1551 *p = pktin.data + pktin.savedpos;
1552 pktin.savedpos += *length;
1554 static Bignum ssh2_pkt_getmp(void)
1560 ssh2_pkt_getstring(&p, &length);
1564 bombout(("internal error: Can't handle negative mpints"));
1567 b = bignum_from_bytes(p, length);
1572 * Helper function to add an SSH2 signature blob to a packet.
1573 * Expects to be shown the public key blob as well as the signature
1574 * blob. Normally works just like ssh2_pkt_addstring, but will
1575 * fiddle with the signature packet if necessary for
1576 * BUG_SSH2_RSA_PADDING.
1578 static void ssh2_add_sigblob(void *pkblob_v, int pkblob_len,
1579 void *sigblob_v, int sigblob_len)
1581 unsigned char *pkblob = (unsigned char *)pkblob_v;
1582 unsigned char *sigblob = (unsigned char *)sigblob_v;
1584 /* dmemdump(pkblob, pkblob_len); */
1585 /* dmemdump(sigblob, sigblob_len); */
1588 * See if this is in fact an ssh-rsa signature and a buggy
1589 * server; otherwise we can just do this the easy way.
1591 if ((ssh_remote_bugs & BUG_SSH2_RSA_PADDING) &&
1592 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1593 int pos, len, siglen;
1596 * Find the byte length of the modulus.
1599 pos = 4+7; /* skip over "ssh-rsa" */
1600 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1601 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1602 pos += 4; /* find modulus itself */
1603 while (len > 0 && pkblob[pos] == 0)
1605 /* debug(("modulus length is %d\n", len)); */
1608 * Now find the signature integer.
1610 pos = 4+7; /* skip over "ssh-rsa" */
1611 siglen = GET_32BIT(sigblob+pos);
1612 /* debug(("signature length is %d\n", siglen)); */
1614 if (len != siglen) {
1615 unsigned char newlen[4];
1616 ssh2_pkt_addstring_start();
1617 ssh2_pkt_addstring_data(sigblob, pos);
1618 /* dmemdump(sigblob, pos); */
1619 pos += 4; /* point to start of actual sig */
1620 PUT_32BIT(newlen, len);
1621 ssh2_pkt_addstring_data(newlen, 4);
1622 /* dmemdump(newlen, 4); */
1624 while (len-- > siglen) {
1625 ssh2_pkt_addstring_data(newlen, 1);
1626 /* dmemdump(newlen, 1); */
1628 ssh2_pkt_addstring_data(sigblob+pos, siglen);
1629 /* dmemdump(sigblob+pos, siglen); */
1633 /* Otherwise fall through and do it the easy way. */
1636 ssh2_pkt_addstring_start();
1637 ssh2_pkt_addstring_data(sigblob, sigblob_len);
1641 * Examine the remote side's version string and compare it against
1642 * a list of known buggy implementations.
1644 static void ssh_detect_bugs(char *vstring)
1646 char *imp; /* pointer to implementation part */
1648 imp += strcspn(imp, "-");
1650 imp += strcspn(imp, "-");
1653 ssh_remote_bugs = 0;
1655 if (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1656 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1657 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")) {
1659 * These versions don't support SSH1_MSG_IGNORE, so we have
1660 * to use a different defence against password length
1663 ssh_remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1664 logevent("We believe remote version has SSH1 ignore bug");
1667 if (!strcmp(imp, "Cisco-1.25")) {
1669 * These versions need a plain password sent; they can't
1670 * handle having a null and a random length of data after
1673 ssh_remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1674 logevent("We believe remote version needs a plain SSH1 password");
1677 if (!strcmp(imp, "Cisco-1.25")) {
1679 * These versions apparently have no clue whatever about
1680 * RSA authentication and will panic and die if they see
1681 * an AUTH_RSA message.
1683 ssh_remote_bugs |= BUG_CHOKES_ON_RSA;
1684 logevent("We believe remote version can't handle RSA authentication");
1687 if (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1688 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1689 !strncmp(imp, "2.1 ", 4)) {
1691 * These versions have the HMAC bug.
1693 ssh_remote_bugs |= BUG_SSH2_HMAC;
1694 logevent("We believe remote version has SSH2 HMAC bug");
1697 if ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1698 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')) {
1700 * These versions have the SSH2 RSA padding bug.
1702 ssh_remote_bugs |= BUG_SSH2_RSA_PADDING;
1703 logevent("We believe remote version has SSH2 RSA padding bug");
1707 static int do_ssh_init(unsigned char c)
1710 static char version[10];
1711 static char *vstring;
1712 static int vstrsize;
1718 /* Search for the string "SSH-" in the input. */
1721 static const int transS[] = { 1, 2, 2, 1 };
1722 static const int transH[] = { 0, 0, 3, 0 };
1723 static const int transminus[] = { 0, 0, 0, -1 };
1734 crReturn(1); /* get another character */
1738 vstring = smalloc(vstrsize);
1739 strcpy(vstring, "SSH-");
1743 crReturn(1); /* get another char */
1744 if (vslen >= vstrsize - 1) {
1746 vstring = srealloc(vstring, vstrsize);
1748 vstring[vslen++] = c;
1753 } else if (i < sizeof(version) - 1)
1755 } else if (c == '\n')
1759 ssh_agentfwd_enabled = FALSE;
1760 rdpkt2_state.incoming_sequence = 0;
1763 vlog = smalloc(20 + vslen);
1764 vstring[strcspn (vstring, "\r\n")] = '\0'; /* remove end-of-line chars */
1765 sprintf(vlog, "Server version: %s", vstring);
1767 ssh_detect_bugs(vstring);
1771 * Server version "1.99" means we can choose whether we use v1
1772 * or v2 protocol. Choice is based on cfg.sshprot.
1774 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
1776 * This is a v2 server. Begin v2 protocol.
1778 char verstring[80], vlog[100];
1779 sprintf(verstring, "SSH-2.0-%s", sshver);
1780 SHA_Init(&exhashbase);
1782 * Hash our version string and their version string.
1784 sha_string(&exhashbase, verstring, strlen(verstring));
1785 sha_string(&exhashbase, vstring, strcspn(vstring, "\r\n"));
1786 sprintf(vlog, "We claim version: %s", verstring);
1788 strcat(verstring, "\n");
1789 logevent("Using SSH protocol version 2");
1790 sk_write(s, verstring, strlen(verstring));
1791 ssh_protocol = ssh2_protocol;
1793 s_rdpkt = ssh2_rdpkt;
1796 * This is a v1 server. Begin v1 protocol.
1798 char verstring[80], vlog[100];
1799 sprintf(verstring, "SSH-%s-%s",
1800 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"),
1802 sprintf(vlog, "We claim version: %s", verstring);
1804 strcat(verstring, "\n");
1806 if (cfg.sshprot == 3) {
1807 bombout(("SSH protocol version 2 required by user but not provided by server"));
1811 logevent("Using SSH protocol version 1");
1812 sk_write(s, verstring, strlen(verstring));
1813 ssh_protocol = ssh1_protocol;
1815 s_rdpkt = ssh1_rdpkt;
1817 ssh_state = SSH_STATE_BEFORE_SIZE;
1824 static void ssh_gotdata(unsigned char *data, int datalen)
1829 * To begin with, feed the characters one by one to the
1830 * protocol initialisation / selection function do_ssh_init().
1831 * When that returns 0, we're done with the initial greeting
1832 * exchange and can move on to packet discipline.
1837 crReturnV; /* more data please */
1838 ret = do_ssh_init(*data);
1846 * We emerge from that loop when the initial negotiation is
1847 * over and we have selected an s_rdpkt function. Now pass
1848 * everything to s_rdpkt, and then pass the resulting packets
1849 * to the proper protocol handler.
1854 while (datalen > 0) {
1855 if (s_rdpkt(&data, &datalen) == 0) {
1856 if (ssh_state == SSH_STATE_CLOSED) {
1859 ssh_protocol(NULL, 0, 1);
1860 if (ssh_state == SSH_STATE_CLOSED) {
1870 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1873 ssh_state = SSH_STATE_CLOSED;
1879 /* A socket error has occurred. */
1880 logevent(error_msg);
1881 connection_fatal(error_msg);
1883 /* Otherwise, the remote side closed the connection normally. */
1888 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1890 ssh_gotdata(data, len);
1891 if (ssh_state == SSH_STATE_CLOSED) {
1901 static void ssh_sent(Plug plug, int bufsize)
1904 * If the send backlog on the SSH socket itself clears, we
1905 * should unthrottle the whole world if it was throttled.
1907 if (bufsize < SSH_MAX_BACKLOG)
1908 ssh_throttle_all(0, bufsize);
1912 * Connect to specified host and port.
1913 * Returns an error message, or NULL on success.
1914 * Also places the canonical host name into `realhost'. It must be
1915 * freed by the caller.
1917 static char *connect_to_host(char *host, int port, char **realhost, int nodelay)
1919 static struct plug_function_table fn_table = {
1924 }, *fn_table_ptr = &fn_table;
1933 savedhost = smalloc(1 + strlen(host));
1935 fatalbox("Out of memory");
1936 strcpy(savedhost, host);
1939 port = 22; /* default ssh port */
1954 sprintf(buf, "Looking up host \"%.170s\"", host);
1957 addr = sk_namelookup(host, realhost);
1958 if ((err = sk_addr_error(addr)))
1962 *realhost = strdup(FWhost);
1969 char buf[200], addrbuf[100];
1970 sk_getaddr(addr, addrbuf, 100);
1971 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
1974 s = new_connection(addr, *realhost, port, 0, 1, nodelay, &fn_table_ptr);
1975 if ((err = sk_socket_error(s))) {
1981 sk_write(s, "connect ", 8);
1982 sk_write(s, FWhost, strlen(FWhost));
1985 sprintf(buf, " %d\n", FWport);
1986 sk_write(s, buf, strlen(buf));
1994 * Throttle or unthrottle the SSH connection.
1996 static void ssh1_throttle(int adjust)
1998 int old_count = ssh1_throttle_count;
1999 ssh1_throttle_count += adjust;
2000 assert(ssh1_throttle_count >= 0);
2001 if (ssh1_throttle_count && !old_count) {
2002 sk_set_frozen(s, 1);
2003 } else if (!ssh1_throttle_count && old_count) {
2004 sk_set_frozen(s, 0);
2009 * Throttle or unthrottle _all_ local data streams (for when sends
2010 * on the SSH connection itself back up).
2012 static void ssh_throttle_all(int enable, int bufsize)
2015 struct ssh_channel *c;
2017 if (enable == ssh_throttled_all)
2019 ssh_throttled_all = enable;
2020 ssh_overall_bufsize = bufsize;
2023 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
2025 case CHAN_MAINSESSION:
2027 * This is treated separately, outside the switch.
2031 x11_override_throttle(c->u.x11.s, enable);
2034 /* Agent channels require no buffer management. */
2037 pfd_override_throttle(c->u.x11.s, enable);
2044 * Handle the key exchange and user authentication phases.
2046 static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
2050 static unsigned char *rsabuf, *keystr1, *keystr2;
2051 unsigned char cookie[8];
2052 struct RSAKey servkey, hostkey;
2053 struct MD5Context md5c;
2054 static unsigned long supported_ciphers_mask, supported_auths_mask;
2055 static int tried_publickey, tried_agent;
2056 static int tis_auth_refused, ccard_auth_refused;
2057 static unsigned char session_id[16];
2058 static int cipher_type;
2059 static char username[100];
2060 static void *publickey_blob;
2061 int publickey_bloblen;
2068 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2069 bombout(("Public key packet not received"));
2073 logevent("Received public keys");
2075 memcpy(cookie, pktin.body, 8);
2077 i = makekey(pktin.body + 8, &servkey, &keystr1, 0);
2078 j = makekey(pktin.body + 8 + i, &hostkey, &keystr2, 0);
2081 * Log the host key fingerprint.
2085 logevent("Host key fingerprint is:");
2086 strcpy(logmsg, " ");
2087 hostkey.comment = NULL;
2088 rsa_fingerprint(logmsg + strlen(logmsg),
2089 sizeof(logmsg) - strlen(logmsg), &hostkey);
2093 ssh1_remote_protoflags = GET_32BIT(pktin.body + 8 + i + j);
2094 supported_ciphers_mask = GET_32BIT(pktin.body + 12 + i + j);
2095 supported_auths_mask = GET_32BIT(pktin.body + 16 + i + j);
2097 ssh1_local_protoflags =
2098 ssh1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2099 ssh1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2102 MD5Update(&md5c, keystr2, hostkey.bytes);
2103 MD5Update(&md5c, keystr1, servkey.bytes);
2104 MD5Update(&md5c, pktin.body, 8);
2105 MD5Final(session_id, &md5c);
2107 for (i = 0; i < 32; i++)
2108 session_key[i] = random_byte();
2110 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2112 rsabuf = smalloc(len);
2114 fatalbox("Out of memory");
2117 * Verify the host key.
2121 * First format the key into a string.
2123 int len = rsastr_len(&hostkey);
2124 char fingerprint[100];
2125 char *keystr = smalloc(len);
2127 fatalbox("Out of memory");
2128 rsastr_fmt(keystr, &hostkey);
2129 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2130 verify_ssh_host_key(savedhost, savedport, "rsa", keystr,
2135 for (i = 0; i < 32; i++) {
2136 rsabuf[i] = session_key[i];
2138 rsabuf[i] ^= session_id[i];
2141 if (hostkey.bytes > servkey.bytes) {
2142 rsaencrypt(rsabuf, 32, &servkey);
2143 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
2145 rsaencrypt(rsabuf, 32, &hostkey);
2146 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
2149 logevent("Encrypted session key");
2152 int cipher_chosen = 0, warn = 0;
2153 char *cipher_string = NULL;
2154 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2155 int next_cipher = cfg.ssh_cipherlist[i];
2156 if (next_cipher == CIPHER_WARN) {
2157 /* If/when we choose a cipher, warn about it */
2159 } else if (next_cipher == CIPHER_AES) {
2160 /* XXX Probably don't need to mention this. */
2161 logevent("AES not supported in SSH1, skipping");
2163 switch (next_cipher) {
2164 case CIPHER_3DES: cipher_type = SSH_CIPHER_3DES;
2165 cipher_string = "3DES"; break;
2166 case CIPHER_BLOWFISH: cipher_type = SSH_CIPHER_BLOWFISH;
2167 cipher_string = "Blowfish"; break;
2168 case CIPHER_DES: cipher_type = SSH_CIPHER_DES;
2169 cipher_string = "single-DES"; break;
2171 if (supported_ciphers_mask & (1 << cipher_type))
2175 if (!cipher_chosen) {
2176 if ((supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2177 bombout(("Server violates SSH 1 protocol by not "
2178 "supporting 3DES encryption"));
2180 /* shouldn't happen */
2181 bombout(("No supported ciphers found"));
2185 /* Warn about chosen cipher if necessary. */
2187 askcipher(cipher_string, 0);
2190 switch (cipher_type) {
2191 case SSH_CIPHER_3DES:
2192 logevent("Using 3DES encryption");
2194 case SSH_CIPHER_DES:
2195 logevent("Using single-DES encryption");
2197 case SSH_CIPHER_BLOWFISH:
2198 logevent("Using Blowfish encryption");
2202 send_packet(SSH1_CMSG_SESSION_KEY,
2203 PKT_CHAR, cipher_type,
2204 PKT_DATA, cookie, 8,
2205 PKT_CHAR, (len * 8) >> 8, PKT_CHAR, (len * 8) & 0xFF,
2206 PKT_DATA, rsabuf, len,
2207 PKT_INT, ssh1_local_protoflags, PKT_END);
2209 logevent("Trying to enable encryption...");
2213 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2214 cipher_type == SSH_CIPHER_DES ? &ssh_des : &ssh_3des;
2215 cipher->sesskey(session_key);
2219 if (pktin.type != SSH1_SMSG_SUCCESS) {
2220 bombout(("Encryption not successfully enabled"));
2224 logevent("Successfully started encryption");
2230 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2232 if (!ssh_get_line("login as: ",
2233 username, sizeof(username), FALSE)) {
2235 * get_line failed to get a username.
2238 logevent("No username provided. Abandoning session.");
2239 ssh_state = SSH_STATE_CLOSED;
2243 c_write_str("login as: ");
2246 crWaitUntil(!ispkt);
2248 switch (c = *in++) {
2257 c_write_str("\b \b");
2264 c_write_str("\b \b");
2273 if (((c >= ' ' && c <= '~') ||
2274 ((unsigned char) c >= 160))
2275 && pos < sizeof(username)-1) {
2276 username[pos++] = c;
2282 c_write_str("\r\n");
2283 username[strcspn(username, "\n\r")] = '\0';
2286 strncpy(username, cfg.username, 99);
2287 username[99] = '\0';
2290 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
2292 char userlog[22 + sizeof(username)];
2293 sprintf(userlog, "Sent username \"%s\"", username);
2295 if (flags & FLAG_INTERACTIVE &&
2296 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2297 strcat(userlog, "\r\n");
2298 c_write_str(userlog);
2305 if ((ssh_remote_bugs & BUG_CHOKES_ON_RSA)) {
2306 /* We must not attempt PK auth. Pretend we've already tried it. */
2307 tried_publickey = tried_agent = 1;
2309 tried_publickey = tried_agent = 0;
2311 tis_auth_refused = ccard_auth_refused = 0;
2312 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2314 if (!rsakey_pubblob(cfg.keyfile, &publickey_blob, &publickey_bloblen))
2315 publickey_blob = NULL;
2317 publickey_blob = NULL;
2319 while (pktin.type == SSH1_SMSG_FAILURE) {
2320 static char password[100];
2321 static char prompt[200];
2324 static int pwpkt_type;
2325 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2327 if (agent_exists() && !tried_agent) {
2329 * Attempt RSA authentication using Pageant.
2331 static unsigned char request[5], *response, *p;
2332 static int responselen;
2333 static int i, nkeys;
2334 static int authed = FALSE;
2338 logevent("Pageant is running. Requesting keys.");
2340 /* Request the keys held by the agent. */
2341 PUT_32BIT(request, 1);
2342 request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2343 agent_query(request, 5, &r, &responselen);
2344 response = (unsigned char *) r;
2345 if (response && responselen >= 5 &&
2346 response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2348 nkeys = GET_32BIT(p);
2352 sprintf(buf, "Pageant has %d SSH1 keys", nkeys);
2355 for (i = 0; i < nkeys; i++) {
2356 static struct RSAKey key;
2357 static Bignum challenge;
2358 static char *commentp;
2359 static int commentlen;
2363 sprintf(buf, "Trying Pageant key #%d", i);
2366 if (publickey_blob &&
2367 !memcmp(p, publickey_blob, publickey_bloblen)) {
2368 logevent("This key matches configured key file");
2369 tried_publickey = 1;
2372 p += ssh1_read_bignum(p, &key.exponent);
2373 p += ssh1_read_bignum(p, &key.modulus);
2374 commentlen = GET_32BIT(p);
2378 send_packet(SSH1_CMSG_AUTH_RSA,
2379 PKT_BIGNUM, key.modulus, PKT_END);
2381 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2382 logevent("Key refused");
2385 logevent("Received RSA challenge");
2386 ssh1_read_bignum(pktin.body, &challenge);
2388 char *agentreq, *q, *ret;
2391 len = 1 + 4; /* message type, bit count */
2392 len += ssh1_bignum_length(key.exponent);
2393 len += ssh1_bignum_length(key.modulus);
2394 len += ssh1_bignum_length(challenge);
2395 len += 16; /* session id */
2396 len += 4; /* response format */
2397 agentreq = smalloc(4 + len);
2398 PUT_32BIT(agentreq, len);
2400 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2401 PUT_32BIT(q, bignum_bitcount(key.modulus));
2403 q += ssh1_write_bignum(q, key.exponent);
2404 q += ssh1_write_bignum(q, key.modulus);
2405 q += ssh1_write_bignum(q, challenge);
2406 memcpy(q, session_id, 16);
2408 PUT_32BIT(q, 1); /* response format */
2409 agent_query(agentreq, len + 4, &vret, &retlen);
2413 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2414 logevent("Sending Pageant's response");
2415 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2416 PKT_DATA, ret + 5, 16,
2420 if (pktin.type == SSH1_SMSG_SUCCESS) {
2422 ("Pageant's response accepted");
2423 if (flags & FLAG_VERBOSE) {
2425 ("Authenticated using RSA key \"");
2426 c_write(commentp, commentlen);
2427 c_write_str("\" from agent\r\n");
2432 ("Pageant's response not accepted");
2435 ("Pageant failed to answer challenge");
2439 logevent("No reply received from Pageant");
2442 freebn(key.exponent);
2443 freebn(key.modulus);
2452 if (*cfg.keyfile && !tried_publickey)
2453 pwpkt_type = SSH1_CMSG_AUTH_RSA;
2455 if (cfg.try_tis_auth &&
2456 (supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2457 !tis_auth_refused) {
2458 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2459 logevent("Requested TIS authentication");
2460 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
2462 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2463 logevent("TIS authentication declined");
2464 if (flags & FLAG_INTERACTIVE)
2465 c_write_str("TIS authentication refused.\r\n");
2466 tis_auth_refused = 1;
2469 int challengelen = ((pktin.body[0] << 24) |
2470 (pktin.body[1] << 16) |
2471 (pktin.body[2] << 8) |
2473 logevent("Received TIS challenge");
2474 if (challengelen > sizeof(prompt) - 1)
2475 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2476 memcpy(prompt, pktin.body + 4, challengelen);
2477 /* Prompt heuristic comes from OpenSSH */
2478 strncpy(prompt + challengelen,
2479 memchr(prompt, '\n', challengelen) ?
2480 "": "\r\nResponse: ",
2481 (sizeof prompt) - challengelen);
2482 prompt[(sizeof prompt) - 1] = '\0';
2485 if (cfg.try_tis_auth &&
2486 (supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2487 !ccard_auth_refused) {
2488 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2489 logevent("Requested CryptoCard authentication");
2490 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
2492 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2493 logevent("CryptoCard authentication declined");
2494 c_write_str("CryptoCard authentication refused.\r\n");
2495 ccard_auth_refused = 1;
2498 int challengelen = ((pktin.body[0] << 24) |
2499 (pktin.body[1] << 16) |
2500 (pktin.body[2] << 8) |
2502 logevent("Received CryptoCard challenge");
2503 if (challengelen > sizeof(prompt) - 1)
2504 challengelen = sizeof(prompt) - 1; /* prevent overrun */
2505 memcpy(prompt, pktin.body + 4, challengelen);
2506 strncpy(prompt + challengelen,
2507 memchr(prompt, '\n', challengelen) ?
2508 "" : "\r\nResponse: ",
2509 sizeof(prompt) - challengelen);
2510 prompt[sizeof(prompt) - 1] = '\0';
2513 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2514 sprintf(prompt, "%.90s@%.90s's password: ",
2515 username, savedhost);
2517 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2518 char *comment = NULL;
2521 if (flags & FLAG_VERBOSE)
2522 c_write_str("Trying public key authentication.\r\n");
2523 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2525 type = key_type(cfg.keyfile);
2526 if (type != SSH_KEYTYPE_SSH1) {
2527 sprintf(msgbuf, "Key is of wrong type (%s)",
2528 key_type_to_str(type));
2530 c_write_str(msgbuf);
2531 c_write_str("\r\n");
2532 tried_publickey = 1;
2535 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2536 if (flags & FLAG_VERBOSE)
2537 c_write_str("No passphrase required.\r\n");
2540 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
2545 * Show password prompt, having first obtained it via a TIS
2546 * or CryptoCard exchange if we're doing TIS or CryptoCard
2550 if (!ssh_get_line(prompt, password, sizeof(password), TRUE)) {
2552 * get_line failed to get a password (for example
2553 * because one was supplied on the command line
2554 * which has already failed to work). Terminate.
2556 send_packet(SSH1_MSG_DISCONNECT,
2557 PKT_STR, "No more passwords available to try",
2559 logevent("Unable to authenticate");
2560 connection_fatal("Unable to authenticate");
2561 ssh_state = SSH_STATE_CLOSED;
2565 /* Prompt may have come from server. We've munged it a bit, so
2566 * we know it to be zero-terminated at least once. */
2567 c_write_untrusted(prompt, strlen(prompt));
2571 crWaitUntil(!ispkt);
2573 switch (c = *in++) {
2593 if (pos < sizeof(password)-1)
2594 password[pos++] = c;
2598 c_write_str("\r\n");
2602 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2604 * Try public key authentication with the specified
2607 static struct RSAKey pubkey;
2608 static Bignum challenge, response;
2610 static unsigned char buffer[32];
2612 tried_publickey = 1;
2613 i = loadrsakey(cfg.keyfile, &pubkey, password);
2615 c_write_str("Couldn't load private key from ");
2616 c_write_str(cfg.keyfile);
2617 c_write_str(".\r\n");
2618 continue; /* go and try password */
2621 c_write_str("Wrong passphrase.\r\n");
2622 tried_publickey = 0;
2623 continue; /* try again */
2627 * Send a public key attempt.
2629 send_packet(SSH1_CMSG_AUTH_RSA,
2630 PKT_BIGNUM, pubkey.modulus, PKT_END);
2633 if (pktin.type == SSH1_SMSG_FAILURE) {
2634 c_write_str("Server refused our public key.\r\n");
2635 continue; /* go and try password */
2637 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2638 bombout(("Bizarre response to offer of public key"));
2641 ssh1_read_bignum(pktin.body, &challenge);
2642 response = rsadecrypt(challenge, &pubkey);
2643 freebn(pubkey.private_exponent); /* burn the evidence */
2645 for (i = 0; i < 32; i++) {
2646 buffer[i] = bignum_byte(response, 31 - i);
2650 MD5Update(&md5c, buffer, 32);
2651 MD5Update(&md5c, session_id, 16);
2652 MD5Final(buffer, &md5c);
2654 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
2655 PKT_DATA, buffer, 16, PKT_END);
2658 if (pktin.type == SSH1_SMSG_FAILURE) {
2659 if (flags & FLAG_VERBOSE)
2661 ("Failed to authenticate with our public key.\r\n");
2662 continue; /* go and try password */
2663 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2665 ("Bizarre response to RSA authentication response"));
2669 break; /* we're through! */
2671 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2673 * Defence against traffic analysis: we send a
2674 * whole bunch of packets containing strings of
2675 * different lengths. One of these strings is the
2676 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2677 * The others are all random data in
2678 * SSH1_MSG_IGNORE packets. This way a passive
2679 * listener can't tell which is the password, and
2680 * hence can't deduce the password length.
2682 * Anybody with a password length greater than 16
2683 * bytes is going to have enough entropy in their
2684 * password that a listener won't find it _that_
2685 * much help to know how long it is. So what we'll
2688 * - if password length < 16, we send 15 packets
2689 * containing string lengths 1 through 15
2691 * - otherwise, we let N be the nearest multiple
2692 * of 8 below the password length, and send 8
2693 * packets containing string lengths N through
2694 * N+7. This won't obscure the order of
2695 * magnitude of the password length, but it will
2696 * introduce a bit of extra uncertainty.
2698 * A few servers (the old 1.2.18 through 1.2.22)
2699 * can't deal with SSH1_MSG_IGNORE. For these
2700 * servers, we need an alternative defence. We make
2701 * use of the fact that the password is interpreted
2702 * as a C string: so we can append a NUL, then some
2705 * One server (a Cisco one) can deal with neither
2706 * SSH1_MSG_IGNORE _nor_ a padded password string.
2707 * For this server we are left with no defences
2708 * against password length sniffing.
2710 if (!(ssh_remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2712 * The server can deal with SSH1_MSG_IGNORE, so
2713 * we can use the primary defence.
2715 int bottom, top, pwlen, i;
2718 pwlen = strlen(password);
2720 bottom = 0; /* zero length passwords are OK! :-) */
2723 bottom = pwlen & ~7;
2727 assert(pwlen >= bottom && pwlen <= top);
2729 randomstr = smalloc(top + 1);
2731 for (i = bottom; i <= top; i++) {
2733 defer_packet(pwpkt_type, PKT_STR, password,
2736 for (j = 0; j < i; j++) {
2738 randomstr[j] = random_byte();
2739 } while (randomstr[j] == '\0');
2741 randomstr[i] = '\0';
2742 defer_packet(SSH1_MSG_IGNORE,
2743 PKT_STR, randomstr, PKT_END);
2746 logevent("Sending password with camouflage packets");
2747 ssh_pkt_defersend();
2749 else if (!(ssh_remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2751 * The server can't deal with SSH1_MSG_IGNORE
2752 * but can deal with padded passwords, so we
2753 * can use the secondary defence.
2759 len = strlen(password);
2760 if (len < sizeof(string)) {
2762 strcpy(string, password);
2763 len++; /* cover the zero byte */
2764 while (len < sizeof(string)) {
2765 string[len++] = (char) random_byte();
2770 logevent("Sending length-padded password");
2771 send_packet(pwpkt_type, PKT_INT, len,
2772 PKT_DATA, s, len, PKT_END);
2775 * The server has _both_
2776 * BUG_CHOKES_ON_SSH1_IGNORE and
2777 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2778 * therefore nothing we can do.
2781 len = strlen(password);
2782 logevent("Sending unpadded password");
2783 send_packet(pwpkt_type, PKT_INT, len,
2784 PKT_DATA, password, len, PKT_END);
2787 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
2790 logevent("Sent password");
2791 memset(password, 0, strlen(password));
2793 if (pktin.type == SSH1_SMSG_FAILURE) {
2794 if (flags & FLAG_VERBOSE)
2795 c_write_str("Access denied\r\n");
2796 logevent("Authentication refused");
2797 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
2798 logevent("Received disconnect request");
2799 ssh_state = SSH_STATE_CLOSED;
2801 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
2802 bombout(("Strange packet received, type %d", pktin.type));
2807 logevent("Authentication successful");
2812 void sshfwd_close(struct ssh_channel *c)
2814 if (c && !c->closes) {
2816 * If the channel's remoteid is -1, we have sent
2817 * CHANNEL_OPEN for this channel, but it hasn't even been
2818 * acknowledged by the server. So we must set a close flag
2819 * on it now, and then when the server acks the channel
2820 * open, we can close it then.
2822 if (((int)c->remoteid) != -1) {
2823 if (ssh_version == 1) {
2824 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2827 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2828 ssh2_pkt_adduint32(c->remoteid);
2833 if (c->type == CHAN_X11) {
2835 logevent("Forwarded X11 connection terminated");
2836 } else if (c->type == CHAN_SOCKDATA ||
2837 c->type == CHAN_SOCKDATA_DORMANT) {
2839 logevent("Forwarded port closed");
2844 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2846 if (ssh_version == 1) {
2847 send_packet(SSH1_MSG_CHANNEL_DATA,
2848 PKT_INT, c->remoteid,
2849 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2851 * In SSH1 we can return 0 here - implying that forwarded
2852 * connections are never individually throttled - because
2853 * the only circumstance that can cause throttling will be
2854 * the whole SSH connection backing up, in which case
2855 * _everything_ will be throttled as a whole.
2859 ssh2_add_channel_data(c, buf, len);
2860 return ssh2_try_send(c);
2864 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2866 if (ssh_version == 1) {
2867 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2868 c->v.v1.throttling = 0;
2872 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2876 static void ssh1_protocol(unsigned char *in, int inlen, int ispkt)
2882 while (!do_ssh1_login(in, inlen, ispkt)) {
2885 if (ssh_state == SSH_STATE_CLOSED)
2888 if (cfg.agentfwd && agent_exists()) {
2889 logevent("Requesting agent forwarding");
2890 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2894 if (pktin.type != SSH1_SMSG_SUCCESS
2895 && pktin.type != SSH1_SMSG_FAILURE) {
2896 bombout(("Protocol confusion"));
2898 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2899 logevent("Agent forwarding refused");
2901 logevent("Agent forwarding enabled");
2902 ssh_agentfwd_enabled = TRUE;
2906 if (cfg.x11_forward) {
2907 char proto[20], data[64];
2908 logevent("Requesting X11 forwarding");
2909 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2910 if (ssh1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2911 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2912 PKT_STR, proto, PKT_STR, data,
2913 PKT_INT, 0, PKT_END);
2915 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING,
2916 PKT_STR, proto, PKT_STR, data, PKT_END);
2921 if (pktin.type != SSH1_SMSG_SUCCESS
2922 && pktin.type != SSH1_SMSG_FAILURE) {
2923 bombout(("Protocol confusion"));
2925 } else if (pktin.type == SSH1_SMSG_FAILURE) {
2926 logevent("X11 forwarding refused");
2928 logevent("X11 forwarding enabled");
2929 ssh_X11_fwd_enabled = TRUE;
2937 int sport,dport,sserv,dserv;
2938 char sports[256], dports[256], host[256];
2942 ssh_rportfwds = newtree234(ssh_rportcmp_ssh1);
2943 /* Add port forwardings. */
2948 while (*e && *e != '\t')
2954 while (*e && *e != ':')
2964 dport = atoi(dports);
2968 se = getservbyname(dports, NULL);
2970 dport = ntohs(se->s_port);
2973 "Service lookup failed for destination port \"%s\"",
2978 sport = atoi(sports);
2982 se = getservbyname(sports, NULL);
2984 sport = ntohs(se->s_port);
2987 "Service lookup failed for source port \"%s\"",
2992 if (sport && dport) {
2994 pfd_addforward(host, dport, sport);
2995 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
2996 " %s:%.*s%.*s%d%.*s",
2997 sserv ? strlen(sports) : 0, sports,
2998 sserv, "(", sport, sserv, ")",
3000 dserv ? strlen(dports) : 0, dports,
3001 dserv, "(", dport, dserv, ")");
3004 struct ssh_rportfwd *pf;
3005 pf = smalloc(sizeof(*pf));
3006 strcpy(pf->dhost, host);
3008 if (add234(ssh_rportfwds, pf) != pf) {
3010 "Duplicate remote port forwarding to %s:%d",
3015 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3016 " forward to %s:%.*s%.*s%d%.*s",
3017 sserv ? strlen(sports) : 0, sports,
3018 sserv, "(", sport, sserv, ")",
3020 dserv ? strlen(dports) : 0, dports,
3021 dserv, "(", dport, dserv, ")");
3023 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST,
3031 if (pktin.type != SSH1_SMSG_SUCCESS
3032 && pktin.type != SSH1_SMSG_FAILURE) {
3033 bombout(("Protocol confusion"));
3035 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3036 c_write_str("Server refused port forwarding\r\n");
3037 ssh_editing = ssh_echoing = 1;
3039 logevent("Remote port forwarding enabled");
3047 send_packet(SSH1_CMSG_REQUEST_PTY,
3048 PKT_STR, cfg.termtype,
3049 PKT_INT, rows, PKT_INT, cols,
3050 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3051 ssh_state = SSH_STATE_INTERMED;
3055 if (pktin.type != SSH1_SMSG_SUCCESS
3056 && pktin.type != SSH1_SMSG_FAILURE) {
3057 bombout(("Protocol confusion"));
3059 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3060 c_write_str("Server refused to allocate pty\r\n");
3061 ssh_editing = ssh_echoing = 1;
3063 logevent("Allocated pty");
3065 ssh_editing = ssh_echoing = 1;
3068 if (cfg.compression) {
3069 send_packet(SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3073 if (pktin.type != SSH1_SMSG_SUCCESS
3074 && pktin.type != SSH1_SMSG_FAILURE) {
3075 bombout(("Protocol confusion"));
3077 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3078 c_write_str("Server refused to compress\r\n");
3080 logevent("Started compression");
3081 ssh1_compressing = TRUE;
3082 zlib_compress_init();
3083 zlib_decompress_init();
3087 * Start the shell or command.
3089 * Special case: if the first-choice command is an SSH2
3090 * subsystem (hence not usable here) and the second choice
3091 * exists, we fall straight back to that.
3094 char *cmd = cfg.remote_cmd_ptr;
3096 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3097 cmd = cfg.remote_cmd_ptr2;
3098 ssh_fallback_cmd = TRUE;
3101 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3103 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
3104 logevent("Started session");
3107 ssh_state = SSH_STATE_SESSION;
3111 ssh_special(TS_EOF);
3113 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
3115 ssh_channels = newtree234(ssh_channelcmp);
3119 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
3120 pktin.type == SSH1_SMSG_STDERR_DATA) {
3121 long len = GET_32BIT(pktin.body);
3123 from_backend(pktin.type == SSH1_SMSG_STDERR_DATA,
3124 pktin.body + 4, len);
3125 if (!ssh1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3126 ssh1_stdout_throttling = 1;
3129 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
3130 ssh_state = SSH_STATE_CLOSED;
3131 logevent("Received disconnect request");
3133 } else if (pktin.type == SSH1_SMSG_X11_OPEN) {
3134 /* Remote side is trying to open a channel to talk to our
3135 * X-Server. Give them back a local channel number. */
3136 struct ssh_channel *c;
3138 logevent("Received X11 connect request");
3139 /* Refuse if X11 forwarding is disabled. */
3140 if (!ssh_X11_fwd_enabled) {
3141 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3142 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3143 logevent("Rejected X11 connect request");
3145 c = smalloc(sizeof(struct ssh_channel));
3147 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3148 logevent("opening X11 forward connection failed");
3150 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3151 PKT_INT, GET_32BIT(pktin.body),
3155 ("opening X11 forward connection succeeded");
3156 c->remoteid = GET_32BIT(pktin.body);
3157 c->localid = alloc_channel_id();
3159 c->v.v1.throttling = 0;
3160 c->type = CHAN_X11; /* identify channel type */
3161 add234(ssh_channels, c);
3162 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3163 PKT_INT, c->remoteid, PKT_INT,
3164 c->localid, PKT_END);
3165 logevent("Opened X11 forward channel");
3168 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
3169 /* Remote side is trying to open a channel to talk to our
3170 * agent. Give them back a local channel number. */
3171 struct ssh_channel *c;
3173 /* Refuse if agent forwarding is disabled. */
3174 if (!ssh_agentfwd_enabled) {
3175 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3176 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3178 c = smalloc(sizeof(struct ssh_channel));
3179 c->remoteid = GET_32BIT(pktin.body);
3180 c->localid = alloc_channel_id();
3182 c->v.v1.throttling = 0;
3183 c->type = CHAN_AGENT; /* identify channel type */
3184 c->u.a.lensofar = 0;
3185 add234(ssh_channels, c);
3186 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3187 PKT_INT, c->remoteid, PKT_INT, c->localid,
3190 } else if (pktin.type == SSH1_MSG_PORT_OPEN) {
3191 /* Remote side is trying to open a channel to talk to a
3192 * forwarded port. Give them back a local channel number. */
3193 struct ssh_channel *c;
3194 struct ssh_rportfwd pf;
3196 char host[256], buf[1024];
3198 c = smalloc(sizeof(struct ssh_channel));
3200 hostsize = GET_32BIT(pktin.body+4);
3201 for(h = host, p = pktin.body+8; hostsize != 0; hostsize--) {
3202 if (h+1 < host+sizeof(host))
3207 port = GET_32BIT(p);
3209 strcpy(pf.dhost, host);
3212 if (find234(ssh_rportfwds, &pf, NULL) == NULL) {
3213 sprintf(buf, "Rejected remote port open request for %s:%d",
3216 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3217 PKT_INT, GET_32BIT(pktin.body), PKT_END);
3219 sprintf(buf, "Received remote port open request for %s:%d",
3222 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3225 sprintf(buf, "Port open failed: %s", e);
3228 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE,
3229 PKT_INT, GET_32BIT(pktin.body),
3232 c->remoteid = GET_32BIT(pktin.body);
3233 c->localid = alloc_channel_id();
3235 c->v.v1.throttling = 0;
3236 c->type = CHAN_SOCKDATA; /* identify channel type */
3237 add234(ssh_channels, c);
3238 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3239 PKT_INT, c->remoteid, PKT_INT,
3240 c->localid, PKT_END);
3241 logevent("Forwarded port opened successfully");
3245 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3246 unsigned int remoteid = GET_32BIT(pktin.body);
3247 unsigned int localid = GET_32BIT(pktin.body+4);
3248 struct ssh_channel *c;
3250 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3251 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3252 c->remoteid = localid;
3253 c->type = CHAN_SOCKDATA;
3254 c->v.v1.throttling = 0;
3255 pfd_confirm(c->u.pfd.s);
3258 if (c && c->closes) {
3260 * We have a pending close on this channel,
3261 * which we decided on before the server acked
3262 * the channel open. So now we know the
3263 * remoteid, we can close it again.
3265 send_packet(SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3269 } else if (pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3270 unsigned int remoteid = GET_32BIT(pktin.body);
3271 unsigned int localid = GET_32BIT(pktin.body+4);
3272 struct ssh_channel *c;
3274 c = find234(ssh_channels, &remoteid, ssh_channelfind);
3275 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3276 logevent("Forwarded connection refused by server");
3277 pfd_close(c->u.pfd.s);
3278 del234(ssh_channels, c);
3282 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3283 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3284 /* Remote side closes a channel. */
3285 unsigned i = GET_32BIT(pktin.body);
3286 struct ssh_channel *c;
3287 c = find234(ssh_channels, &i, ssh_channelfind);
3291 (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3292 if (!(c->closes & closetype))
3293 send_packet(pktin.type, PKT_INT, c->remoteid,
3295 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3296 logevent("Forwarded X11 connection terminated");
3297 assert(c->u.x11.s != NULL);
3298 x11_close(c->u.x11.s);
3301 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3302 logevent("Forwarded port closed");
3303 assert(c->u.pfd.s != NULL);
3304 pfd_close(c->u.pfd.s);
3307 c->closes |= closetype;
3308 if (c->closes == 3) {
3309 del234(ssh_channels, c);
3313 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
3314 /* Data sent down one of our channels. */
3315 int i = GET_32BIT(pktin.body);
3316 int len = GET_32BIT(pktin.body + 4);
3317 unsigned char *p = pktin.body + 8;
3318 struct ssh_channel *c;
3319 c = find234(ssh_channels, &i, ssh_channelfind);
3324 bufsize = x11_send(c->u.x11.s, p, len);
3327 bufsize = pfd_send(c->u.pfd.s, p, len);
3330 /* Data for an agent message. Buffer it. */
3332 if (c->u.a.lensofar < 4) {
3333 int l = min(4 - c->u.a.lensofar, len);
3334 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3338 c->u.a.lensofar += l;
3340 if (c->u.a.lensofar == 4) {
3342 4 + GET_32BIT(c->u.a.msglen);
3343 c->u.a.message = smalloc(c->u.a.totallen);
3344 memcpy(c->u.a.message, c->u.a.msglen, 4);
3346 if (c->u.a.lensofar >= 4 && len > 0) {
3348 min(c->u.a.totallen - c->u.a.lensofar,
3350 memcpy(c->u.a.message + c->u.a.lensofar, p,
3354 c->u.a.lensofar += l;
3356 if (c->u.a.lensofar == c->u.a.totallen) {
3357 void *reply, *sentreply;
3359 agent_query(c->u.a.message,
3360 c->u.a.totallen, &reply,
3365 /* Fake SSH_AGENT_FAILURE. */
3366 sentreply = "\0\0\0\1\5";
3369 send_packet(SSH1_MSG_CHANNEL_DATA,
3370 PKT_INT, c->remoteid,
3372 PKT_DATA, sentreply, replylen,
3376 sfree(c->u.a.message);
3377 c->u.a.lensofar = 0;
3380 bufsize = 0; /* agent channels never back up */
3383 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3384 c->v.v1.throttling = 1;
3388 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
3389 /* may be from EXEC_SHELL on some servers */
3390 } else if (pktin.type == SSH1_SMSG_FAILURE) {
3391 /* may be from EXEC_SHELL on some servers
3392 * if no pty is available or in other odd cases. Ignore */
3393 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
3395 ssh_exitcode = GET_32BIT(pktin.body);
3396 sprintf(buf, "Server sent command exit status %d",
3399 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3401 * In case `helpful' firewalls or proxies tack
3402 * extra human-readable text on the end of the
3403 * session which we might mistake for another
3404 * encrypted packet, we close the session once
3405 * we've sent EXIT_CONFIRMATION.
3407 ssh_state = SSH_STATE_CLOSED;
3410 bombout(("Strange packet received: type %d", pktin.type));
3415 int len = min(inlen, 512);
3416 send_packet(SSH1_CMSG_STDIN_DATA,
3417 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3428 * Utility routine for decoding comma-separated strings in KEXINIT.
3430 static int in_commasep_string(char *needle, char *haystack, int haylen)
3432 int needlen = strlen(needle);
3435 * Is it at the start of the string?
3437 if (haylen >= needlen && /* haystack is long enough */
3438 !memcmp(needle, haystack, needlen) && /* initial match */
3439 (haylen == needlen || haystack[needlen] == ',')
3440 /* either , or EOS follows */
3444 * If not, search for the next comma and resume after that.
3445 * If no comma found, terminate.
3447 while (haylen > 0 && *haystack != ',')
3448 haylen--, haystack++;
3451 haylen--, haystack++; /* skip over comma itself */
3456 * SSH2 key creation method.
3458 static void ssh2_mkkey(Bignum K, char *H, char *sessid, char chr,
3462 /* First 20 bytes. */
3465 SHA_Bytes(&s, H, 20);
3466 SHA_Bytes(&s, &chr, 1);
3467 SHA_Bytes(&s, sessid, 20);
3468 SHA_Final(&s, keyspace);
3469 /* Next 20 bytes. */
3472 SHA_Bytes(&s, H, 20);
3473 SHA_Bytes(&s, keyspace, 20);
3474 SHA_Final(&s, keyspace + 20);
3478 * Handle the SSH2 transport layer.
3480 static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
3482 static int i, j, len, nbits, pbits, warn;
3484 static Bignum p, g, e, f, K;
3485 static int kex_init_value, kex_reply_value;
3486 static const struct ssh_mac **maclist;
3488 static const struct ssh2_cipher *cscipher_tobe = NULL;
3489 static const struct ssh2_cipher *sccipher_tobe = NULL;
3490 static const struct ssh_mac *csmac_tobe = NULL;
3491 static const struct ssh_mac *scmac_tobe = NULL;
3492 static const struct ssh_compress *cscomp_tobe = NULL;
3493 static const struct ssh_compress *sccomp_tobe = NULL;
3494 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
3495 static int hostkeylen, siglen;
3496 static void *hkey; /* actual host key */
3497 static unsigned char exchange_hash[20];
3498 static unsigned char keyspace[40];
3499 static int n_preferred_ciphers;
3500 static const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3501 static const struct ssh_compress *preferred_comp;
3502 static int cipherstr_started;
3503 static int first_kex;
3510 * Set up the preferred ciphers. (NULL => warn below here)
3512 n_preferred_ciphers = 0;
3513 for (i = 0; i < CIPHER_MAX; i++) {
3514 switch (cfg.ssh_cipherlist[i]) {
3515 case CIPHER_BLOWFISH:
3516 preferred_ciphers[n_preferred_ciphers] = &ssh2_blowfish;
3517 n_preferred_ciphers++;
3520 if (cfg.ssh2_des_cbc) {
3521 preferred_ciphers[n_preferred_ciphers] = &ssh2_des;
3522 n_preferred_ciphers++;
3526 preferred_ciphers[n_preferred_ciphers] = &ssh2_3des;
3527 n_preferred_ciphers++;
3530 preferred_ciphers[n_preferred_ciphers] = &ssh2_aes;
3531 n_preferred_ciphers++;
3534 /* Flag for later. Don't bother if it's the last in
3536 if (i < CIPHER_MAX - 1) {
3537 preferred_ciphers[n_preferred_ciphers] = NULL;
3538 n_preferred_ciphers++;
3545 * Set up preferred compression.
3547 if (cfg.compression)
3548 preferred_comp = &ssh_zlib;
3550 preferred_comp = &ssh_comp_none;
3553 * Be prepared to work around the buggy MAC problem.
3555 if (cfg.buggymac || (ssh_remote_bugs & BUG_SSH2_HMAC))
3556 maclist = buggymacs, nmacs = lenof(buggymacs);
3558 maclist = macs, nmacs = lenof(macs);
3562 * Construct and send our key exchange packet.
3564 ssh2_pkt_init(SSH2_MSG_KEXINIT);
3565 for (i = 0; i < 16; i++)
3566 ssh2_pkt_addbyte((unsigned char) random_byte());
3567 /* List key exchange algorithms. */
3568 ssh2_pkt_addstring_start();
3569 for (i = 0; i < lenof(kex_algs); i++) {
3570 ssh2_pkt_addstring_str(kex_algs[i]->name);
3571 if (i < lenof(kex_algs) - 1)
3572 ssh2_pkt_addstring_str(",");
3574 /* List server host key algorithms. */
3575 ssh2_pkt_addstring_start();
3576 for (i = 0; i < lenof(hostkey_algs); i++) {
3577 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
3578 if (i < lenof(hostkey_algs) - 1)
3579 ssh2_pkt_addstring_str(",");
3581 /* List client->server encryption algorithms. */
3582 ssh2_pkt_addstring_start();
3583 cipherstr_started = 0;
3584 for (i = 0; i < n_preferred_ciphers; i++) {
3585 const struct ssh2_ciphers *c = preferred_ciphers[i];
3586 if (!c) continue; /* warning flag */
3587 for (j = 0; j < c->nciphers; j++) {
3588 if (cipherstr_started)
3589 ssh2_pkt_addstring_str(",");
3590 ssh2_pkt_addstring_str(c->list[j]->name);
3591 cipherstr_started = 1;
3594 /* List server->client encryption algorithms. */
3595 ssh2_pkt_addstring_start();
3596 cipherstr_started = 0;
3597 for (i = 0; i < n_preferred_ciphers; i++) {
3598 const struct ssh2_ciphers *c = preferred_ciphers[i];
3599 if (!c) continue; /* warning flag */
3600 for (j = 0; j < c->nciphers; j++) {
3601 if (cipherstr_started)
3602 ssh2_pkt_addstring_str(",");
3603 ssh2_pkt_addstring_str(c->list[j]->name);
3604 cipherstr_started = 1;
3607 /* List client->server MAC algorithms. */
3608 ssh2_pkt_addstring_start();
3609 for (i = 0; i < nmacs; i++) {
3610 ssh2_pkt_addstring_str(maclist[i]->name);
3612 ssh2_pkt_addstring_str(",");
3614 /* List server->client MAC algorithms. */
3615 ssh2_pkt_addstring_start();
3616 for (i = 0; i < nmacs; i++) {
3617 ssh2_pkt_addstring_str(maclist[i]->name);
3619 ssh2_pkt_addstring_str(",");
3621 /* List client->server compression algorithms. */
3622 ssh2_pkt_addstring_start();
3623 for (i = 0; i < lenof(compressions) + 1; i++) {
3624 const struct ssh_compress *c =
3625 i == 0 ? preferred_comp : compressions[i - 1];
3626 ssh2_pkt_addstring_str(c->name);
3627 if (i < lenof(compressions))
3628 ssh2_pkt_addstring_str(",");
3630 /* List server->client compression algorithms. */
3631 ssh2_pkt_addstring_start();
3632 for (i = 0; i < lenof(compressions) + 1; i++) {
3633 const struct ssh_compress *c =
3634 i == 0 ? preferred_comp : compressions[i - 1];
3635 ssh2_pkt_addstring_str(c->name);
3636 if (i < lenof(compressions))
3637 ssh2_pkt_addstring_str(",");
3639 /* List client->server languages. Empty list. */
3640 ssh2_pkt_addstring_start();
3641 /* List server->client languages. Empty list. */
3642 ssh2_pkt_addstring_start();
3643 /* First KEX packet does _not_ follow, because we're not that brave. */
3644 ssh2_pkt_addbool(FALSE);
3646 ssh2_pkt_adduint32(0);
3648 exhash = exhashbase;
3649 sha_string(&exhash, pktout.data + 5, pktout.length - 5);
3655 sha_string(&exhash, pktin.data + 5, pktin.length - 5);
3658 * Now examine the other side's KEXINIT to see what we're up
3661 if (pktin.type != SSH2_MSG_KEXINIT) {
3662 bombout(("expected key exchange packet from server"));
3667 cscipher_tobe = NULL;
3668 sccipher_tobe = NULL;
3673 pktin.savedpos += 16; /* skip garbage cookie */
3674 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
3675 for (i = 0; i < lenof(kex_algs); i++) {
3676 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3681 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
3682 for (i = 0; i < lenof(hostkey_algs); i++) {
3683 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3684 hostkey = hostkey_algs[i];
3688 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
3690 for (i = 0; i < n_preferred_ciphers; i++) {
3691 const struct ssh2_ciphers *c = preferred_ciphers[i];
3695 for (j = 0; j < c->nciphers; j++) {
3696 if (in_commasep_string(c->list[j]->name, str, len)) {
3697 cscipher_tobe = c->list[j];
3702 if (cscipher_tobe) {
3704 askcipher(cscipher_tobe->name, 1);
3708 if (!cscipher_tobe) {
3709 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3713 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
3715 for (i = 0; i < n_preferred_ciphers; i++) {
3716 const struct ssh2_ciphers *c = preferred_ciphers[i];
3720 for (j = 0; j < c->nciphers; j++) {
3721 if (in_commasep_string(c->list[j]->name, str, len)) {
3722 sccipher_tobe = c->list[j];
3727 if (sccipher_tobe) {
3729 askcipher(sccipher_tobe->name, 2);
3733 if (!sccipher_tobe) {
3734 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3738 ssh2_pkt_getstring(&str, &len); /* client->server mac */
3739 for (i = 0; i < nmacs; i++) {
3740 if (in_commasep_string(maclist[i]->name, str, len)) {
3741 csmac_tobe = maclist[i];
3745 ssh2_pkt_getstring(&str, &len); /* server->client mac */
3746 for (i = 0; i < nmacs; i++) {
3747 if (in_commasep_string(maclist[i]->name, str, len)) {
3748 scmac_tobe = maclist[i];
3752 ssh2_pkt_getstring(&str, &len); /* client->server compression */
3753 for (i = 0; i < lenof(compressions) + 1; i++) {
3754 const struct ssh_compress *c =
3755 i == 0 ? preferred_comp : compressions[i - 1];
3756 if (in_commasep_string(c->name, str, len)) {
3761 ssh2_pkt_getstring(&str, &len); /* server->client compression */
3762 for (i = 0; i < lenof(compressions) + 1; i++) {
3763 const struct ssh_compress *c =
3764 i == 0 ? preferred_comp : compressions[i - 1];
3765 if (in_commasep_string(c->name, str, len)) {
3772 * Work out the number of bits of key we will need from the key
3773 * exchange. We start with the maximum key length of either
3779 csbits = cscipher_tobe->keylen;
3780 scbits = sccipher_tobe->keylen;
3781 nbits = (csbits > scbits ? csbits : scbits);
3783 /* The keys only have 160-bit entropy, since they're based on
3784 * a SHA-1 hash. So cap the key size at 160 bits. */
3789 * If we're doing Diffie-Hellman group exchange, start by
3790 * requesting a group.
3792 if (kex == &ssh_diffiehellman_gex) {
3793 logevent("Doing Diffie-Hellman group exchange");
3794 ssh_pkt_ctx |= SSH2_PKTCTX_DHGEX;
3796 * Work out how big a DH group we will need to allow that
3799 pbits = 512 << ((nbits - 1) / 64);
3800 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
3801 ssh2_pkt_adduint32(pbits);
3805 if (pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3806 bombout(("expected key exchange group packet from server"));
3809 p = ssh2_pkt_getmp();
3810 g = ssh2_pkt_getmp();
3811 dh_setup_group(p, g);
3812 kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3813 kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3815 ssh_pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3817 kex_init_value = SSH2_MSG_KEXDH_INIT;
3818 kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3821 logevent("Doing Diffie-Hellman key exchange");
3823 * Now generate and send e for Diffie-Hellman.
3825 e = dh_create_e(nbits * 2);
3826 ssh2_pkt_init(kex_init_value);
3831 if (pktin.type != kex_reply_value) {
3832 bombout(("expected key exchange reply packet from server"));
3835 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
3836 f = ssh2_pkt_getmp();
3837 ssh2_pkt_getstring(&sigdata, &siglen);
3841 sha_string(&exhash, hostkeydata, hostkeylen);
3842 if (kex == &ssh_diffiehellman_gex) {
3843 sha_uint32(&exhash, pbits);
3844 sha_mpint(&exhash, p);
3845 sha_mpint(&exhash, g);
3847 sha_mpint(&exhash, e);
3848 sha_mpint(&exhash, f);
3849 sha_mpint(&exhash, K);
3850 SHA_Final(&exhash, exchange_hash);
3855 debug(("Exchange hash is:\n"));
3856 dmemdump(exchange_hash, 20);
3859 hkey = hostkey->newkey(hostkeydata, hostkeylen);
3861 !hostkey->verifysig(hkey, sigdata, siglen, exchange_hash, 20)) {
3862 bombout(("Server's host key did not match the signature supplied"));
3867 * Authenticate remote host: verify host key. (We've already
3868 * checked the signature of the exchange hash.)
3870 keystr = hostkey->fmtkey(hkey);
3871 fingerprint = hostkey->fingerprint(hkey);
3872 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
3873 keystr, fingerprint);
3874 if (first_kex) { /* don't bother logging this in rekeys */
3875 logevent("Host key fingerprint is:");
3876 logevent(fingerprint);
3880 hostkey->freekey(hkey);
3883 * Send SSH2_MSG_NEWKEYS.
3885 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
3889 * Expect SSH2_MSG_NEWKEYS from server.
3892 if (pktin.type != SSH2_MSG_NEWKEYS) {
3893 bombout(("expected new-keys packet from server"));
3898 * Create and initialise session keys.
3900 cscipher = cscipher_tobe;
3901 sccipher = sccipher_tobe;
3904 cscomp = cscomp_tobe;
3905 sccomp = sccomp_tobe;
3906 cscomp->compress_init();
3907 sccomp->decompress_init();
3909 * Set IVs after keys. Here we use the exchange hash from the
3910 * _first_ key exchange.
3913 memcpy(ssh2_session_id, exchange_hash, sizeof(exchange_hash));
3914 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'C', keyspace);
3915 cscipher->setcskey(keyspace);
3916 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'D', keyspace);
3917 sccipher->setsckey(keyspace);
3918 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'A', keyspace);
3919 cscipher->setcsiv(keyspace);
3920 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'B', keyspace);
3921 sccipher->setsciv(keyspace);
3922 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'E', keyspace);
3923 csmac->setcskey(keyspace);
3924 ssh2_mkkey(K, exchange_hash, ssh2_session_id, 'F', keyspace);
3925 scmac->setsckey(keyspace);
3928 * If this is the first key exchange phase, we must pass the
3929 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3930 * wants to see it but because it will need time to initialise
3931 * itself before it sees an actual packet. In subsequent key
3932 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3933 * it would only confuse the layer above.
3941 * Now we're encrypting. Begin returning 1 to the protocol main
3942 * function so that other things can run on top of the
3943 * transport. If we ever see a KEXINIT, we must go back to the
3946 while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT)) {
3949 logevent("Server initiated key re-exchange");
3950 goto begin_key_exchange;
3956 * Add data to an SSH2 channel output buffer.
3958 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
3961 bufchain_add(&c->v.v2.outbuffer, buf, len);
3965 * Attempt to send data on an SSH2 channel.
3967 static int ssh2_try_send(struct ssh_channel *c)
3969 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
3972 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
3973 if ((unsigned)len > c->v.v2.remwindow)
3974 len = c->v.v2.remwindow;
3975 if ((unsigned)len > c->v.v2.remmaxpkt)
3976 len = c->v.v2.remmaxpkt;
3977 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
3978 ssh2_pkt_adduint32(c->remoteid);
3979 ssh2_pkt_addstring_start();
3980 ssh2_pkt_addstring_data(data, len);
3982 bufchain_consume(&c->v.v2.outbuffer, len);
3983 c->v.v2.remwindow -= len;
3987 * After having sent as much data as we can, return the amount
3990 return bufchain_size(&c->v.v2.outbuffer);
3994 * Potentially enlarge the window on an SSH2 channel.
3996 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
3999 * Never send WINDOW_ADJUST for a channel that the remote side
4000 * already thinks it's closed; there's no point, since it won't
4001 * be sending any more data anyway.
4006 if (newwin > c->v.v2.locwindow) {
4007 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4008 ssh2_pkt_adduint32(c->remoteid);
4009 ssh2_pkt_adduint32(newwin - c->v.v2.locwindow);
4011 c->v.v2.locwindow = newwin;
4016 * Handle the SSH2 userauth and connection layers.
4018 static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
4021 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4023 AUTH_KEYBOARD_INTERACTIVE
4027 AUTH_TYPE_PUBLICKEY,
4028 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4029 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4031 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4032 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4034 static int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4035 static int tried_pubkey_config, tried_agent, tried_keyb_inter;
4036 static int kbd_inter_running;
4037 static int we_are_in;
4038 static int num_prompts, curr_prompt, echo;
4039 static char username[100];
4040 static int got_username;
4041 static char pwprompt[200];
4042 static char password[100];
4043 static void *publickey_blob;
4044 static int publickey_bloblen;
4049 * Request userauth protocol, and await a response to it.
4051 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
4052 ssh2_pkt_addstring("ssh-userauth");
4054 crWaitUntilV(ispkt);
4055 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4056 bombout(("Server refused user authentication protocol"));
4061 * We repeat this whole loop, including the username prompt,
4062 * until we manage a successful authentication. If the user
4063 * types the wrong _password_, they are sent back to the
4064 * beginning to try another username. (If they specify a
4065 * username in the config, they are never asked, even if they
4066 * do give a wrong password.)
4068 * I think this best serves the needs of
4070 * - the people who have no configuration, no keys, and just
4071 * want to try repeated (username,password) pairs until they
4072 * type both correctly
4074 * - people who have keys and configuration but occasionally
4075 * need to fall back to passwords
4077 * - people with a key held in Pageant, who might not have
4078 * logged in to a particular machine before; so they want to
4079 * type a username, and then _either_ their key will be
4080 * accepted, _or_ they will type a password. If they mistype
4081 * the username they will want to be able to get back and
4085 got_username = FALSE;
4094 if (got_username && !cfg.change_username) {
4096 * We got a username last time round this loop, and
4097 * with change_username turned off we don't try to get
4100 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4102 if (!ssh_get_line("login as: ",
4103 username, sizeof(username), FALSE)) {
4105 * get_line failed to get a username.
4108 logevent("No username provided. Abandoning session.");
4109 ssh_state = SSH_STATE_CLOSED;
4113 c_write_str("login as: ");
4116 crWaitUntilV(!ispkt);
4118 switch (c = *in++) {
4127 c_write_str("\b \b");
4134 c_write_str("\b \b");
4143 if (((c >= ' ' && c <= '~') ||
4144 ((unsigned char) c >= 160))
4145 && pos < sizeof(username)-1) {
4146 username[pos++] = c;
4153 c_write_str("\r\n");
4154 username[strcspn(username, "\n\r")] = '\0';
4157 strncpy(username, cfg.username, 99);
4158 username[99] = '\0';
4159 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4160 sprintf(stuff, "Using username \"%s\".\r\n", username);
4164 got_username = TRUE;
4167 * Send an authentication request using method "none": (a)
4168 * just in case it succeeds, and (b) so that we know what
4169 * authentication methods we can usefully try next.
4171 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4173 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4174 ssh2_pkt_addstring(username);
4175 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4176 ssh2_pkt_addstring("none"); /* method */
4178 type = AUTH_TYPE_NONE;
4182 tried_pubkey_config = FALSE;
4183 tried_agent = FALSE;
4184 tried_keyb_inter = FALSE;
4185 kbd_inter_running = FALSE;
4186 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4189 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4190 keytype = key_type(cfg.keyfile);
4191 if (keytype == SSH_KEYTYPE_SSH2)
4192 publickey_blob = ssh2_userkey_loadpub(cfg.keyfile, NULL,
4193 &publickey_bloblen);
4196 logeventf("Unable to use this key file (%s)",
4197 key_type_to_str(keytype));
4198 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4199 cfg.keyfile, key_type_to_str(keytype));
4200 c_write_str(msgbuf);
4201 publickey_blob = NULL;
4204 publickey_blob = NULL;
4208 * Wait for the result of the last authentication request.
4211 crWaitUntilV(ispkt);
4212 while (pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4216 * Don't show the banner if we're operating in
4217 * non-verbose non-interactive mode. (It's probably
4218 * a script, which means nobody will read the
4219 * banner _anyway_, and moreover the printing of
4220 * the banner will screw up processing on the
4221 * output of (say) plink.)
4223 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4224 ssh2_pkt_getstring(&banner, &size);
4226 c_write_untrusted(banner, size);
4228 crWaitUntilV(ispkt);
4230 if (pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4231 logevent("Access granted");
4236 if (kbd_inter_running &&
4237 pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4239 * This is either a further set-of-prompts packet
4240 * in keyboard-interactive authentication, or it's
4241 * the same one and we came back here with `gotit'
4242 * set. In the former case, we must reset the
4243 * curr_prompt variable.
4247 } else if (pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4248 bombout(("Strange packet received during authentication: type %d",
4256 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4257 * we can look at the string in it and know what we can
4258 * helpfully try next.
4260 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4263 ssh2_pkt_getstring(&methods, &methlen);
4264 kbd_inter_running = FALSE;
4265 if (!ssh2_pkt_getbool()) {
4267 * We have received an unequivocal Access
4268 * Denied. This can translate to a variety of
4271 * - if we'd just tried "none" authentication,
4272 * it's not worth printing anything at all
4274 * - if we'd just tried a public key _offer_,
4275 * the message should be "Server refused our
4276 * key" (or no message at all if the key
4277 * came from Pageant)
4279 * - if we'd just tried anything else, the
4280 * message really should be "Access denied".
4282 * Additionally, if we'd just tried password
4283 * authentication, we should break out of this
4284 * whole loop so as to go back to the username
4287 if (type == AUTH_TYPE_NONE) {
4289 } else if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4290 type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4291 if (type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4292 c_write_str("Server refused our key\r\n");
4293 logevent("Server refused public key");
4294 } else if (type == AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4295 /* server declined keyboard-interactive; ignore */
4297 c_write_str("Access denied\r\n");
4298 logevent("Access denied");
4299 if (type == AUTH_TYPE_PASSWORD) {
4305 c_write_str("Further authentication required\r\n");
4306 logevent("Further authentication required");
4310 in_commasep_string("publickey", methods, methlen);
4312 in_commasep_string("password", methods, methlen);
4313 can_keyb_inter = cfg.try_ki_auth &&
4314 in_commasep_string("keyboard-interactive", methods, methlen);
4318 ssh_pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4320 if (!method && can_pubkey && agent_exists() && !tried_agent) {
4322 * Attempt public-key authentication using Pageant.
4324 static unsigned char request[5], *response, *p;
4325 static int responselen;
4326 static int i, nkeys;
4327 static int authed = FALSE;
4330 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4334 logevent("Pageant is running. Requesting keys.");
4336 /* Request the keys held by the agent. */
4337 PUT_32BIT(request, 1);
4338 request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4339 agent_query(request, 5, &r, &responselen);
4340 response = (unsigned char *) r;
4341 if (response && responselen >= 5 &&
4342 response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4344 nkeys = GET_32BIT(p);
4348 sprintf(buf, "Pageant has %d SSH2 keys", nkeys);
4351 for (i = 0; i < nkeys; i++) {
4352 static char *pkblob, *alg, *commentp;
4353 static int pklen, alglen, commentlen;
4354 static int siglen, retlen, len;
4355 static char *q, *agentreq, *ret;
4360 sprintf(buf, "Trying Pageant key #%d", i);
4363 pklen = GET_32BIT(p);
4365 if (publickey_blob &&
4366 pklen == publickey_bloblen &&
4367 !memcmp(p, publickey_blob, publickey_bloblen)) {
4368 logevent("This key matches configured key file");
4369 tried_pubkey_config = 1;
4373 alglen = GET_32BIT(pkblob);
4375 commentlen = GET_32BIT(p);
4379 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4380 ssh2_pkt_addstring(username);
4381 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4382 ssh2_pkt_addstring("publickey"); /* method */
4383 ssh2_pkt_addbool(FALSE); /* no signature included */
4384 ssh2_pkt_addstring_start();
4385 ssh2_pkt_addstring_data(alg, alglen);
4386 ssh2_pkt_addstring_start();
4387 ssh2_pkt_addstring_data(pkblob, pklen);
4390 crWaitUntilV(ispkt);
4391 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4392 logevent("Key refused");
4396 if (flags & FLAG_VERBOSE) {
4398 ("Authenticating with public key \"");
4399 c_write(commentp, commentlen);
4400 c_write_str("\" from agent\r\n");
4404 * Server is willing to accept the key.
4405 * Construct a SIGN_REQUEST.
4407 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4408 ssh2_pkt_addstring(username);
4409 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4410 ssh2_pkt_addstring("publickey"); /* method */
4411 ssh2_pkt_addbool(TRUE);
4412 ssh2_pkt_addstring_start();
4413 ssh2_pkt_addstring_data(alg, alglen);
4414 ssh2_pkt_addstring_start();
4415 ssh2_pkt_addstring_data(pkblob, pklen);
4417 siglen = pktout.length - 5 + 4 + 20;
4418 len = 1; /* message type */
4419 len += 4 + pklen; /* key blob */
4420 len += 4 + siglen; /* data to sign */
4421 len += 4; /* flags */
4422 agentreq = smalloc(4 + len);
4423 PUT_32BIT(agentreq, len);
4425 *q++ = SSH2_AGENTC_SIGN_REQUEST;
4426 PUT_32BIT(q, pklen);
4428 memcpy(q, pkblob, pklen);
4430 PUT_32BIT(q, siglen);
4432 /* Now the data to be signed... */
4435 memcpy(q, ssh2_session_id, 20);
4437 memcpy(q, pktout.data + 5, pktout.length - 5);
4438 q += pktout.length - 5;
4439 /* And finally the (zero) flags word. */
4441 agent_query(agentreq, len + 4, &vret, &retlen);
4445 if (ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4446 logevent("Sending Pageant's response");
4447 ssh2_add_sigblob(pkblob, pklen,
4448 ret + 9, GET_32BIT(ret + 5));
4454 ("Pageant failed to answer challenge");
4464 if (!method && can_pubkey && publickey_blob
4465 && !tried_pubkey_config) {
4466 unsigned char *pub_blob;
4467 char *algorithm, *comment;
4470 tried_pubkey_config = TRUE;
4472 ssh_pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4475 * Try the public key supplied in the configuration.
4477 * First, offer the public blob to see if the server is
4478 * willing to accept it.
4480 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4483 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4484 ssh2_pkt_addstring(username);
4485 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4486 ssh2_pkt_addstring("publickey"); /* method */
4487 ssh2_pkt_addbool(FALSE); /* no signature included */
4488 ssh2_pkt_addstring(algorithm);
4489 ssh2_pkt_addstring_start();
4490 ssh2_pkt_addstring_data(pub_blob, pub_blob_len);
4492 logevent("Offered public key"); /* FIXME */
4494 crWaitUntilV(ispkt);
4495 if (pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4497 type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4498 continue; /* key refused; give up on it */
4501 logevent("Offer of public key accepted");
4503 * Actually attempt a serious authentication using
4506 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4508 "Passphrase for key \"%.100s\": ",
4514 c_write_str("Authenticating with public key \"");
4515 c_write_str(comment);
4516 c_write_str("\"\r\n");
4517 method = AUTH_PUBLICKEY_FILE;
4521 if (!method && can_keyb_inter && !tried_keyb_inter) {
4522 method = AUTH_KEYBOARD_INTERACTIVE;
4523 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4524 tried_keyb_inter = TRUE;
4526 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4528 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4529 ssh2_pkt_addstring(username);
4530 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4531 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4532 ssh2_pkt_addstring(""); /* lang */
4533 ssh2_pkt_addstring("");
4536 crWaitUntilV(ispkt);
4537 if (pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4538 if (pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4540 logevent("Keyboard-interactive authentication refused");
4541 type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4545 kbd_inter_running = TRUE;
4549 if (kbd_inter_running) {
4550 method = AUTH_KEYBOARD_INTERACTIVE;
4551 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4552 tried_keyb_inter = TRUE;
4554 ssh_pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4556 if (curr_prompt == 0) {
4558 * We've got a fresh USERAUTH_INFO_REQUEST.
4559 * Display header data, and start going through
4562 char *name, *inst, *lang;
4563 int name_len, inst_len, lang_len;
4565 ssh2_pkt_getstring(&name, &name_len);
4566 ssh2_pkt_getstring(&inst, &inst_len);
4567 ssh2_pkt_getstring(&lang, &lang_len);
4569 c_write_untrusted(name, name_len);
4573 c_write_untrusted(inst, inst_len);
4576 num_prompts = ssh2_pkt_getuint32();
4580 * If there are prompts remaining in the packet,
4581 * display one and get a response.
4583 if (curr_prompt < num_prompts) {
4587 ssh2_pkt_getstring(&prompt, &prompt_len);
4588 if (prompt_len > 0) {
4589 strncpy(pwprompt, prompt, sizeof(pwprompt));
4590 pwprompt[prompt_len < sizeof(pwprompt) ?
4591 prompt_len : sizeof(pwprompt)-1] = '\0';
4594 "<server failed to send prompt>: ");
4596 echo = ssh2_pkt_getbool();
4602 if (!method && can_passwd) {
4603 method = AUTH_PASSWORD;
4604 ssh_pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4605 sprintf(pwprompt, "%.90s@%.90s's password: ", username,
4612 if (!ssh_get_line(pwprompt, password,
4613 sizeof(password), TRUE)) {
4615 * get_line failed to get a password (for
4616 * example because one was supplied on the
4617 * command line which has already failed to
4620 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4621 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4623 ("No more passwords available to try");
4624 ssh2_pkt_addstring("en"); /* language tag */
4626 logevent("Unable to authenticate");
4627 connection_fatal("Unable to authenticate");
4628 ssh_state = SSH_STATE_CLOSED;
4635 c_write_untrusted(pwprompt, strlen(pwprompt));
4640 crWaitUntilV(!ispkt);
4642 switch (c = *in++) {
4662 if (pos < sizeof(password)-1)
4663 password[pos++] = c;
4667 c_write_str("\r\n");
4671 if (method == AUTH_PUBLICKEY_FILE) {
4673 * We have our passphrase. Now try the actual authentication.
4675 struct ssh2_userkey *key;
4677 key = ssh2_load_userkey(cfg.keyfile, password);
4678 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4679 if (key == SSH2_WRONG_PASSPHRASE) {
4680 c_write_str("Wrong passphrase\r\n");
4681 tried_pubkey_config = FALSE;
4683 c_write_str("Unable to load private key\r\n");
4684 tried_pubkey_config = TRUE;
4686 /* Send a spurious AUTH_NONE to return to the top. */
4687 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4688 ssh2_pkt_addstring(username);
4689 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4690 ssh2_pkt_addstring("none"); /* method */
4692 type = AUTH_TYPE_NONE;
4694 unsigned char *pkblob, *sigblob, *sigdata;
4695 int pkblob_len, sigblob_len, sigdata_len;
4698 * We have loaded the private key and the server
4699 * has announced that it's willing to accept it.
4700 * Hallelujah. Generate a signature and send it.
4702 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4703 ssh2_pkt_addstring(username);
4704 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4705 ssh2_pkt_addstring("publickey"); /* method */
4706 ssh2_pkt_addbool(TRUE);
4707 ssh2_pkt_addstring(key->alg->name);
4708 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4709 ssh2_pkt_addstring_start();
4710 ssh2_pkt_addstring_data(pkblob, pkblob_len);
4713 * The data to be signed is:
4717 * followed by everything so far placed in the
4720 sigdata_len = pktout.length - 5 + 4 + 20;
4721 sigdata = smalloc(sigdata_len);
4722 PUT_32BIT(sigdata, 20);
4723 memcpy(sigdata + 4, ssh2_session_id, 20);
4724 memcpy(sigdata + 24, pktout.data + 5,
4726 sigblob = key->alg->sign(key->data, sigdata,
4727 sigdata_len, &sigblob_len);
4728 ssh2_add_sigblob(pkblob, pkblob_len,
4729 sigblob, sigblob_len);
4735 type = AUTH_TYPE_PUBLICKEY;
4737 } else if (method == AUTH_PASSWORD) {
4739 * We send the password packet lumped tightly together with
4740 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4741 * string long enough to make the total length of the two
4742 * packets constant. This should ensure that a passive
4743 * listener doing traffic analyis can't work out the length
4746 * For this to work, we need an assumption about the
4747 * maximum length of the password packet. I think 256 is
4748 * pretty conservative. Anyone using a password longer than
4749 * that probably doesn't have much to worry about from
4750 * people who find out how long their password is!
4752 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
4753 ssh2_pkt_addstring(username);
4754 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4755 ssh2_pkt_addstring("password");
4756 ssh2_pkt_addbool(FALSE);
4757 ssh2_pkt_addstring(password);
4760 * We'll include a string that's an exact multiple of the
4761 * cipher block size. If the cipher is NULL for some
4762 * reason, we don't do this trick at all because we gain
4768 stringlen = (256 - deferred_len);
4769 stringlen += cscipher->blksize - 1;
4770 stringlen -= (stringlen % cscipher->blksize);
4773 * Temporarily disable actual compression,
4774 * so we can guarantee to get this string
4775 * exactly the length we want it. The
4776 * compression-disabling routine should
4777 * return an integer indicating how many
4778 * bytes we should adjust our string length
4781 stringlen -= cscomp->disable_compression();
4783 ssh2_pkt_init(SSH2_MSG_IGNORE);
4784 ssh2_pkt_addstring_start();
4785 for (i = 0; i < stringlen; i++) {
4786 char c = (char) random_byte();
4787 ssh2_pkt_addstring_data(&c, 1);
4791 ssh_pkt_defersend();
4792 logevent("Sent password");
4793 type = AUTH_TYPE_PASSWORD;
4794 } else if (method == AUTH_KEYBOARD_INTERACTIVE) {
4795 if (curr_prompt == 0) {
4796 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
4797 ssh2_pkt_adduint32(num_prompts);
4799 if (need_pw) { /* only add pw if we just got one! */
4800 ssh2_pkt_addstring(password);
4801 memset(password, 0, sizeof(password));
4804 if (curr_prompt >= num_prompts) {
4808 * If there are prompts remaining, we set
4809 * `gotit' so that we won't attempt to get
4810 * another packet. Then we go back round the
4811 * loop and will end up retrieving another
4812 * prompt out of the existing packet. Funky or
4817 type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4820 ("No supported authentication methods left to try!\r\n");
4822 ("No supported authentications offered. Disconnecting");
4823 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
4824 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
4826 ("No supported authentication methods available");
4827 ssh2_pkt_addstring("en"); /* language tag */
4829 ssh_state = SSH_STATE_CLOSED;
4833 } while (!we_are_in);
4836 * Now we're authenticated for the connection protocol. The
4837 * connection protocol will automatically have started at this
4838 * point; there's no need to send SERVICE_REQUEST.
4842 * So now create a channel with a session in it.
4844 ssh_channels = newtree234(ssh_channelcmp);
4845 mainchan = smalloc(sizeof(struct ssh_channel));
4846 mainchan->localid = alloc_channel_id();
4847 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
4848 ssh2_pkt_addstring("session");
4849 ssh2_pkt_adduint32(mainchan->localid);
4850 mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4851 ssh2_pkt_adduint32(mainchan->v.v2.locwindow); /* our window size */
4852 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
4854 crWaitUntilV(ispkt);
4855 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4856 bombout(("Server refused to open a session"));
4858 /* FIXME: error data comes back in FAILURE packet */
4860 if (ssh2_pkt_getuint32() != mainchan->localid) {
4861 bombout(("Server's channel confirmation cited wrong channel"));
4864 mainchan->remoteid = ssh2_pkt_getuint32();
4865 mainchan->type = CHAN_MAINSESSION;
4866 mainchan->closes = 0;
4867 mainchan->v.v2.remwindow = ssh2_pkt_getuint32();
4868 mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32();
4869 bufchain_init(&mainchan->v.v2.outbuffer);
4870 add234(ssh_channels, mainchan);
4871 logevent("Opened channel for session");
4874 * Potentially enable X11 forwarding.
4876 if (cfg.x11_forward) {
4877 char proto[20], data[64];
4878 logevent("Requesting X11 forwarding");
4879 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4880 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
4881 ssh2_pkt_adduint32(mainchan->remoteid);
4882 ssh2_pkt_addstring("x11-req");
4883 ssh2_pkt_addbool(1); /* want reply */
4884 ssh2_pkt_addbool(0); /* many connections */
4885 ssh2_pkt_addstring(proto);
4886 ssh2_pkt_addstring(data);
4887 ssh2_pkt_adduint32(0); /* screen number */
4891 crWaitUntilV(ispkt);
4892 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4893 unsigned i = ssh2_pkt_getuint32();
4894 struct ssh_channel *c;
4895 c = find234(ssh_channels, &i, ssh_channelfind);
4897 continue; /* nonexistent channel */
4898 c->v.v2.remwindow += ssh2_pkt_getuint32();
4900 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4902 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4903 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4904 bombout(("Unexpected response to X11 forwarding request:"
4905 " packet type %d", pktin.type));
4908 logevent("X11 forwarding refused");
4910 logevent("X11 forwarding enabled");
4911 ssh_X11_fwd_enabled = TRUE;
4916 * Enable port forwardings.
4919 static char *e; /* preserve across crReturn */
4922 int sport,dport,sserv,dserv;
4923 char sports[256], dports[256], host[256];
4927 ssh_rportfwds = newtree234(ssh_rportcmp_ssh2);
4928 /* Add port forwardings. */
4933 while (*e && *e != '\t')
4939 while (*e && *e != ':')
4949 dport = atoi(dports);
4953 se = getservbyname(dports, NULL);
4955 dport = ntohs(se->s_port);
4958 "Service lookup failed for destination port \"%s\"",
4963 sport = atoi(sports);
4967 se = getservbyname(sports, NULL);
4969 sport = ntohs(se->s_port);
4972 "Service lookup failed for source port \"%s\"",
4977 if (sport && dport) {
4979 pfd_addforward(host, dport, sport);
4980 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
4981 " %s:%.*s%.*s%d%.*s",
4982 sserv ? strlen(sports) : 0, sports,
4983 sserv, "(", sport, sserv, ")",
4985 dserv ? strlen(dports) : 0, dports,
4986 dserv, "(", dport, dserv, ")");
4989 struct ssh_rportfwd *pf;
4990 pf = smalloc(sizeof(*pf));
4991 strcpy(pf->dhost, host);
4994 if (add234(ssh_rportfwds, pf) != pf) {
4996 "Duplicate remote port forwarding to %s:%d",
5001 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5002 " forward to %s:%.*s%.*s%d%.*s",
5003 sserv ? strlen(sports) : 0, sports,
5004 sserv, "(", sport, sserv, ")",
5006 dserv ? strlen(dports) : 0, dports,
5007 dserv, "(", dport, dserv, ")");
5009 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
5010 ssh2_pkt_addstring("tcpip-forward");
5011 ssh2_pkt_addbool(1);/* want reply */
5012 if (cfg.rport_acceptall)
5013 ssh2_pkt_addstring("0.0.0.0");
5015 ssh2_pkt_addstring("127.0.0.1");
5016 ssh2_pkt_adduint32(sport);
5020 crWaitUntilV(ispkt);
5021 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5022 unsigned i = ssh2_pkt_getuint32();
5023 struct ssh_channel *c;
5024 c = find234(ssh_channels, &i, ssh_channelfind);
5026 continue;/* nonexistent channel */
5027 c->v.v2.remwindow += ssh2_pkt_getuint32();
5029 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5031 if (pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5032 if (pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5033 bombout(("Unexpected response to port "
5034 "forwarding request: packet type %d",
5038 logevent("Server refused this port forwarding");
5040 logevent("Remote port forwarding enabled");
5049 * Potentially enable agent forwarding.
5051 if (cfg.agentfwd && agent_exists()) {
5052 logevent("Requesting OpenSSH-style agent forwarding");
5053 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5054 ssh2_pkt_adduint32(mainchan->remoteid);
5055 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5056 ssh2_pkt_addbool(1); /* want reply */
5060 crWaitUntilV(ispkt);
5061 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5062 unsigned i = ssh2_pkt_getuint32();
5063 struct ssh_channel *c;
5064 c = find234(ssh_channels, &i, ssh_channelfind);
5066 continue; /* nonexistent channel */
5067 c->v.v2.remwindow += ssh2_pkt_getuint32();
5069 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5071 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5072 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5073 bombout(("Unexpected response to agent forwarding request:"
5074 " packet type %d", pktin.type));
5077 logevent("Agent forwarding refused");
5079 logevent("Agent forwarding enabled");
5080 ssh_agentfwd_enabled = TRUE;
5085 * Now allocate a pty for the session.
5088 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5089 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5090 ssh2_pkt_addstring("pty-req");
5091 ssh2_pkt_addbool(1); /* want reply */
5092 ssh2_pkt_addstring(cfg.termtype);
5093 ssh2_pkt_adduint32(cols);
5094 ssh2_pkt_adduint32(rows);
5095 ssh2_pkt_adduint32(0); /* pixel width */
5096 ssh2_pkt_adduint32(0); /* pixel height */
5097 ssh2_pkt_addstring_start();
5098 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5100 ssh_state = SSH_STATE_INTERMED;
5103 crWaitUntilV(ispkt);
5104 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5105 unsigned i = ssh2_pkt_getuint32();
5106 struct ssh_channel *c;
5107 c = find234(ssh_channels, &i, ssh_channelfind);
5109 continue; /* nonexistent channel */
5110 c->v.v2.remwindow += ssh2_pkt_getuint32();
5112 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5114 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5115 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5116 bombout(("Unexpected response to pty request:"
5117 " packet type %d", pktin.type));
5120 c_write_str("Server refused to allocate pty\r\n");
5121 ssh_editing = ssh_echoing = 1;
5123 logevent("Allocated pty");
5126 ssh_editing = ssh_echoing = 1;
5130 * Start a shell or a remote command. We may have to attempt
5131 * this twice if the config data has provided a second choice
5138 if (ssh_fallback_cmd) {
5139 subsys = cfg.ssh_subsys2;
5140 cmd = cfg.remote_cmd_ptr2;
5142 subsys = cfg.ssh_subsys;
5143 cmd = cfg.remote_cmd_ptr;
5146 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5147 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
5149 ssh2_pkt_addstring("subsystem");
5150 ssh2_pkt_addbool(1); /* want reply */
5151 ssh2_pkt_addstring(cmd);
5153 ssh2_pkt_addstring("exec");
5154 ssh2_pkt_addbool(1); /* want reply */
5155 ssh2_pkt_addstring(cmd);
5157 ssh2_pkt_addstring("shell");
5158 ssh2_pkt_addbool(1); /* want reply */
5162 crWaitUntilV(ispkt);
5163 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5164 unsigned i = ssh2_pkt_getuint32();
5165 struct ssh_channel *c;
5166 c = find234(ssh_channels, &i, ssh_channelfind);
5168 continue; /* nonexistent channel */
5169 c->v.v2.remwindow += ssh2_pkt_getuint32();
5171 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5172 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5173 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5174 bombout(("Unexpected response to shell/command request:"
5175 " packet type %d", pktin.type));
5179 * We failed to start the command. If this is the
5180 * fallback command, we really are finished; if it's
5181 * not, and if the fallback command exists, try falling
5182 * back to it before complaining.
5184 if (!ssh_fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5185 logevent("Primary command failed; attempting fallback");
5186 ssh_fallback_cmd = TRUE;
5189 bombout(("Server refused to start a shell/command"));
5192 logevent("Started a shell/command");
5197 ssh_state = SSH_STATE_SESSION;
5201 ssh_special(TS_EOF);
5206 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
5209 static int try_send;
5213 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
5214 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5217 unsigned i = ssh2_pkt_getuint32();
5218 struct ssh_channel *c;
5219 c = find234(ssh_channels, &i, ssh_channelfind);
5221 continue; /* nonexistent channel */
5222 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5223 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
5224 continue; /* extended but not stderr */
5225 ssh2_pkt_getstring(&data, &length);
5228 c->v.v2.locwindow -= length;
5230 case CHAN_MAINSESSION:
5232 from_backend(pktin.type ==
5233 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5237 bufsize = x11_send(c->u.x11.s, data, length);
5240 bufsize = pfd_send(c->u.pfd.s, data, length);
5243 while (length > 0) {
5244 if (c->u.a.lensofar < 4) {
5245 int l = min(4 - c->u.a.lensofar, length);
5246 memcpy(c->u.a.msglen + c->u.a.lensofar,
5250 c->u.a.lensofar += l;
5252 if (c->u.a.lensofar == 4) {
5254 4 + GET_32BIT(c->u.a.msglen);
5255 c->u.a.message = smalloc(c->u.a.totallen);
5256 memcpy(c->u.a.message, c->u.a.msglen, 4);
5258 if (c->u.a.lensofar >= 4 && length > 0) {
5260 min(c->u.a.totallen - c->u.a.lensofar,
5262 memcpy(c->u.a.message + c->u.a.lensofar,
5266 c->u.a.lensofar += l;
5268 if (c->u.a.lensofar == c->u.a.totallen) {
5269 void *reply, *sentreply;
5271 agent_query(c->u.a.message,
5272 c->u.a.totallen, &reply,
5277 /* Fake SSH_AGENT_FAILURE. */
5278 sentreply = "\0\0\0\1\5";
5281 ssh2_add_channel_data(c, sentreply,
5286 sfree(c->u.a.message);
5287 c->u.a.lensofar = 0;
5294 * If we are not buffering too much data,
5295 * enlarge the window again at the remote side.
5297 if (bufsize < OUR_V2_WINSIZE)
5298 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5300 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
5301 ssh_state = SSH_STATE_CLOSED;
5302 logevent("Received disconnect message");
5304 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
5305 unsigned i = ssh2_pkt_getuint32();
5306 struct ssh_channel *c;
5308 c = find234(ssh_channels, &i, ssh_channelfind);
5310 continue; /* nonexistent channel */
5312 if (c->type == CHAN_X11) {
5314 * Remote EOF on an X11 channel means we should
5315 * wrap up and close the channel ourselves.
5317 x11_close(c->u.x11.s);
5319 } else if (c->type == CHAN_AGENT) {
5321 } else if (c->type == CHAN_SOCKDATA) {
5322 pfd_close(c->u.pfd.s);
5325 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5326 unsigned i = ssh2_pkt_getuint32();
5327 struct ssh_channel *c;
5329 c = find234(ssh_channels, &i, ssh_channelfind);
5331 continue; /* nonexistent channel */
5332 /* Do pre-close processing on the channel. */
5334 case CHAN_MAINSESSION:
5335 break; /* nothing to see here, move along */
5337 if (c->u.x11.s != NULL)
5338 x11_close(c->u.x11.s);
5345 if (c->u.pfd.s != NULL)
5346 pfd_close(c->u.pfd.s);
5350 if (c->closes == 0) {
5351 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5352 ssh2_pkt_adduint32(c->remoteid);
5355 del234(ssh_channels, c);
5356 bufchain_clear(&c->v.v2.outbuffer);
5360 * See if that was the last channel left open.
5362 if (count234(ssh_channels) == 0) {
5365 * We used to send SSH_MSG_DISCONNECT here,
5366 * because I'd believed that _every_ conforming
5367 * SSH2 connection had to end with a disconnect
5368 * being sent by at least one side; apparently
5369 * I was wrong and it's perfectly OK to
5370 * unceremoniously slam the connection shut
5371 * when you're done, and indeed OpenSSH feels
5372 * this is more polite than sending a
5373 * DISCONNECT. So now we don't.
5375 logevent("All channels closed. Disconnecting");
5376 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5377 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5378 ssh2_pkt_addstring("All open channels closed");
5379 ssh2_pkt_addstring("en"); /* language tag */
5382 ssh_state = SSH_STATE_CLOSED;
5385 continue; /* remote sends close; ignore (FIXME) */
5386 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5387 unsigned i = ssh2_pkt_getuint32();
5388 struct ssh_channel *c;
5389 c = find234(ssh_channels, &i, ssh_channelfind);
5391 continue; /* nonexistent channel */
5392 c->v.v2.remwindow += ssh2_pkt_getuint32();
5394 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5395 unsigned i = ssh2_pkt_getuint32();
5396 struct ssh_channel *c;
5397 c = find234(ssh_channels, &i, ssh_channelfind);
5399 continue; /* nonexistent channel */
5400 if (c->type != CHAN_SOCKDATA_DORMANT)
5401 continue; /* dunno why they're confirming this */
5402 c->remoteid = ssh2_pkt_getuint32();
5403 c->type = CHAN_SOCKDATA;
5404 c->v.v2.remwindow = ssh2_pkt_getuint32();
5405 c->v.v2.remmaxpkt = ssh2_pkt_getuint32();
5407 pfd_confirm(c->u.pfd.s);
5410 * We have a pending close on this channel,
5411 * which we decided on before the server acked
5412 * the channel open. So now we know the
5413 * remoteid, we can close it again.
5415 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5416 ssh2_pkt_adduint32(c->remoteid);
5419 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5420 unsigned i = ssh2_pkt_getuint32();
5421 struct ssh_channel *c;
5422 c = find234(ssh_channels, &i, ssh_channelfind);
5424 continue; /* nonexistent channel */
5425 if (c->type != CHAN_SOCKDATA_DORMANT)
5426 continue; /* dunno why they're failing this */
5428 logevent("Forwarded connection refused by server");
5430 pfd_close(c->u.pfd.s);
5432 del234(ssh_channels, c);
5434 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5437 int typelen, want_reply;
5438 struct ssh_channel *c;
5440 localid = ssh2_pkt_getuint32();
5441 ssh2_pkt_getstring(&type, &typelen);
5442 want_reply = ssh2_pkt_getbool();
5445 * First, check that the channel exists. Otherwise,
5446 * we can instantly disconnect with a rude message.
5448 c = find234(ssh_channels, &localid, ssh_channelfind);
5451 sprintf(buf, "Received channel request for nonexistent"
5452 " channel %d", localid);
5454 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5455 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION);
5456 ssh2_pkt_addstring(buf);
5457 ssh2_pkt_addstring("en"); /* language tag */
5459 connection_fatal("%s", buf);
5460 ssh_state = SSH_STATE_CLOSED;
5465 * Having got the channel number, we now look at
5466 * the request type string to see if it's something
5469 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5471 /* We recognise "exit-status" on the primary channel. */
5473 ssh_exitcode = ssh2_pkt_getuint32();
5474 sprintf(buf, "Server sent command exit status %d",
5478 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS);
5479 ssh2_pkt_adduint32(c->remoteid);
5484 * This is a channel request we don't know
5485 * about, so we now either ignore the request
5486 * or respond with CHANNEL_FAILURE, depending
5490 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE);
5491 ssh2_pkt_adduint32(c->remoteid);
5495 } else if (pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5497 int typelen, want_reply;
5499 ssh2_pkt_getstring(&type, &typelen);
5500 want_reply = ssh2_pkt_getbool();
5503 * We currently don't support any global requests
5504 * at all, so we either ignore the request or
5505 * respond with REQUEST_FAILURE, depending on
5509 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5512 } else if (pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5516 struct ssh_channel *c;
5517 unsigned remid, winsize, pktsize;
5518 ssh2_pkt_getstring(&type, &typelen);
5519 c = smalloc(sizeof(struct ssh_channel));
5521 remid = ssh2_pkt_getuint32();
5522 winsize = ssh2_pkt_getuint32();
5523 pktsize = ssh2_pkt_getuint32();
5525 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5526 if (!ssh_X11_fwd_enabled)
5527 error = "X11 forwarding is not enabled";
5528 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5530 error = "Unable to open an X11 connection";
5534 } else if (typelen == 15 &&
5535 !memcmp(type, "forwarded-tcpip", 15)) {
5536 struct ssh_rportfwd pf, *realpf;
5539 ssh2_pkt_getstring(&dummy, &dummylen);/* skip address */
5540 pf.sport = ssh2_pkt_getuint32();
5541 realpf = find234(ssh_rportfwds, &pf, NULL);
5542 if (realpf == NULL) {
5543 error = "Remote port is not recognised";
5545 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5548 sprintf(buf, "Received remote port open request for %s:%d",
5549 realpf->dhost, realpf->dport);
5552 sprintf(buf, "Port open failed: %s", e);
5554 error = "Port open failed";
5556 logevent("Forwarded port opened successfully");
5557 c->type = CHAN_SOCKDATA;
5560 } else if (typelen == 22 &&
5561 !memcmp(type, "auth-agent@openssh.com", 3)) {
5562 if (!ssh_agentfwd_enabled)
5563 error = "Agent forwarding is not enabled";
5565 c->type = CHAN_AGENT; /* identify channel type */
5566 c->u.a.lensofar = 0;
5569 error = "Unsupported channel type requested";
5572 c->remoteid = remid;
5574 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5575 ssh2_pkt_adduint32(c->remoteid);
5576 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED);
5577 ssh2_pkt_addstring(error);
5578 ssh2_pkt_addstring("en"); /* language tag */
5582 c->localid = alloc_channel_id();
5584 c->v.v2.locwindow = OUR_V2_WINSIZE;
5585 c->v.v2.remwindow = winsize;
5586 c->v.v2.remmaxpkt = pktsize;
5587 bufchain_init(&c->v.v2.outbuffer);
5588 add234(ssh_channels, c);
5589 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5590 ssh2_pkt_adduint32(c->remoteid);
5591 ssh2_pkt_adduint32(c->localid);
5592 ssh2_pkt_adduint32(c->v.v2.locwindow);
5593 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5597 bombout(("Strange packet received: type %d", pktin.type));
5602 * We have spare data. Add it to the channel buffer.
5604 ssh2_add_channel_data(mainchan, in, inlen);
5609 struct ssh_channel *c;
5611 * Try to send data on all channels if we can.
5613 for (i = 0; NULL != (c = index234(ssh_channels, i)); i++) {
5614 int bufsize = ssh2_try_send(c);
5617 case CHAN_MAINSESSION:
5618 /* stdin need not receive an unthrottle
5619 * notification since it will be polled */
5622 x11_unthrottle(c->u.x11.s);
5625 /* agent sockets are request/response and need no
5626 * buffer management */
5629 pfd_unthrottle(c->u.pfd.s);
5641 * Handle the top-level SSH2 protocol.
5643 static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
5645 if (do_ssh2_transport(in, inlen, ispkt) == 0)
5647 do_ssh2_authconn(in, inlen, ispkt);
5651 * Called to set up the connection.
5653 * Returns an error message, or NULL on success.
5655 static char *ssh_init(char *host, int port, char **realhost, int nodelay)
5660 if (crypto_startup() == 0)
5661 return "Microsoft high encryption pack not installed!";
5667 ssh1_throttle_count = 0;
5668 ssh_overall_bufsize = 0;
5669 ssh_fallback_cmd = 0;
5671 p = connect_to_host(host, port, realhost, nodelay);
5679 * Called to send data down the Telnet connection.
5681 static int ssh_send(char *buf, int len)
5683 if (s == NULL || ssh_protocol == NULL)
5686 ssh_protocol(buf, len, 0);
5688 return ssh_sendbuffer();
5692 * Called to query the current amount of buffered stdin data.
5694 static int ssh_sendbuffer(void)
5698 if (s == NULL || ssh_protocol == NULL)
5702 * If the SSH socket itself has backed up, add the total backup
5703 * size on that to any individual buffer on the stdin channel.
5706 if (ssh_throttled_all)
5707 override_value = ssh_overall_bufsize;
5709 if (ssh_version == 1) {
5710 return override_value;
5711 } else if (ssh_version == 2) {
5712 if (!mainchan || mainchan->closes > 0)
5713 return override_value;
5715 return override_value + bufchain_size(&mainchan->v.v2.outbuffer);
5722 * Called to set the size of the window from SSH's POV.
5724 static void ssh_size(void)
5726 switch (ssh_state) {
5727 case SSH_STATE_BEFORE_SIZE:
5728 case SSH_STATE_PREPACKET:
5729 case SSH_STATE_CLOSED:
5730 break; /* do nothing */
5731 case SSH_STATE_INTERMED:
5732 size_needed = TRUE; /* buffer for later */
5734 case SSH_STATE_SESSION:
5736 if (ssh_version == 1) {
5737 send_packet(SSH1_CMSG_WINDOW_SIZE,
5738 PKT_INT, rows, PKT_INT, cols,
5739 PKT_INT, 0, PKT_INT, 0, PKT_END);
5741 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
5742 ssh2_pkt_adduint32(mainchan->remoteid);
5743 ssh2_pkt_addstring("window-change");
5744 ssh2_pkt_addbool(0);
5745 ssh2_pkt_adduint32(cols);
5746 ssh2_pkt_adduint32(rows);
5747 ssh2_pkt_adduint32(0);
5748 ssh2_pkt_adduint32(0);
5757 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5758 * can send an EOF and collect resulting output (e.g. `plink
5761 static void ssh_special(Telnet_Special code)
5763 if (code == TS_EOF) {
5764 if (ssh_state != SSH_STATE_SESSION) {
5766 * Buffer the EOF in case we are pre-SESSION, so we can
5767 * send it as soon as we reach SESSION.
5773 if (ssh_version == 1) {
5774 send_packet(SSH1_CMSG_EOF, PKT_END);
5776 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
5777 ssh2_pkt_adduint32(mainchan->remoteid);
5780 logevent("Sent EOF message");
5781 } else if (code == TS_PING) {
5782 if (ssh_state == SSH_STATE_CLOSED
5783 || ssh_state == SSH_STATE_PREPACKET) return;
5784 if (ssh_version == 1) {
5785 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5787 ssh2_pkt_init(SSH2_MSG_IGNORE);
5788 ssh2_pkt_addstring_start();
5796 void *new_sock_channel(Socket s)
5798 struct ssh_channel *c;
5799 c = smalloc(sizeof(struct ssh_channel));
5802 c->remoteid = -1; /* to be set when open confirmed */
5803 c->localid = alloc_channel_id();
5805 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5807 bufchain_init(&c->v.v2.outbuffer);
5808 add234(ssh_channels, c);
5814 * This is called when stdout/stderr (the entity to which
5815 * from_backend sends data) manages to clear some backlog.
5817 void ssh_unthrottle(int bufsize)
5819 if (ssh_version == 1) {
5820 if (ssh1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5821 ssh1_stdout_throttling = 0;
5825 if (mainchan && mainchan->closes == 0)
5826 ssh2_set_window(mainchan, OUR_V2_WINSIZE - bufsize);
5830 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
5832 struct ssh_channel *c = (struct ssh_channel *)channel;
5835 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5838 if (ssh_version == 1) {
5839 send_packet(SSH1_MSG_PORT_OPEN,
5840 PKT_INT, c->localid,
5843 //PKT_STR, <org:orgport>,
5846 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
5847 ssh2_pkt_addstring("direct-tcpip");
5848 ssh2_pkt_adduint32(c->localid);
5849 c->v.v2.locwindow = OUR_V2_WINSIZE;
5850 ssh2_pkt_adduint32(c->v.v2.locwindow);/* our window size */
5851 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
5852 ssh2_pkt_addstring(hostname);
5853 ssh2_pkt_adduint32(port);
5855 * We make up values for the originator data; partly it's
5856 * too much hassle to keep track, and partly I'm not
5857 * convinced the server should be told details like that
5858 * about my local network configuration.
5860 ssh2_pkt_addstring("client-side-connection");
5861 ssh2_pkt_adduint32(0);
5867 static Socket ssh_socket(void)
5872 static int ssh_sendok(void)
5877 static int ssh_ldisc(int option)
5879 if (option == LD_ECHO)
5881 if (option == LD_EDIT)
5886 static int ssh_return_exitcode(void)
5888 return ssh_exitcode;
5891 Backend ssh_backend = {
5898 ssh_return_exitcode,