18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
22 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
23 (s ? sk_close(s), s = NULL : 0), \
24 connection_fatal msg )
26 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29 #define SSH1_CMSG_USER 4 /* 0x4 */
30 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
39 #define SSH1_SMSG_FAILURE 15 /* 0xf */
40 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43 #define SSH1_CMSG_EOF 19 /* 0x13 */
44 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
50 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
53 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
55 #define SSH1_MSG_IGNORE 32 /* 0x20 */
56 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
59 #define SSH1_MSG_DEBUG 36 /* 0x24 */
60 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
61 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
68 #define SSH1_AUTH_TIS 5 /* 0x5 */
69 #define SSH1_AUTH_CCARD 16 /* 0x10 */
71 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
72 /* Mask for protoflags we will echo back to server if seen */
73 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
75 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
76 #define SSH2_MSG_IGNORE 2 /* 0x2 */
77 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
78 #define SSH2_MSG_DEBUG 4 /* 0x4 */
79 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
80 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
81 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
82 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
83 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
84 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
85 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
86 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
87 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
88 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
89 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
96 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
97 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
98 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
99 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
100 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
101 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
102 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
103 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
104 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
105 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
106 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
107 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
108 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
109 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
110 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
113 * Packet type contexts, so that ssh2_pkt_type can correctly decode
114 * the ambiguous type numbers back into the correct type strings.
116 #define SSH2_PKTCTX_DHGROUP1 0x0001
117 #define SSH2_PKTCTX_DHGEX 0x0002
118 #define SSH2_PKTCTX_PUBLICKEY 0x0010
119 #define SSH2_PKTCTX_PASSWORD 0x0020
120 #define SSH2_PKTCTX_KBDINTER 0x0040
121 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
123 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
124 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
125 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
126 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
127 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
128 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
129 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
130 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
131 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
132 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
133 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
134 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
135 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
136 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
137 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
139 static const char *const ssh2_disconnect_reasons
[] = {
141 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
142 "SSH_DISCONNECT_PROTOCOL_ERROR",
143 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
144 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
145 "SSH_DISCONNECT_MAC_ERROR",
146 "SSH_DISCONNECT_COMPRESSION_ERROR",
147 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
148 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
149 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
150 "SSH_DISCONNECT_CONNECTION_LOST",
151 "SSH_DISCONNECT_BY_APPLICATION",
152 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
153 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
154 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
155 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
158 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
159 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
160 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
161 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
163 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
166 * Various remote-bug flags.
168 #define BUG_CHOKES_ON_SSH1_IGNORE 1
169 #define BUG_SSH2_HMAC 2
170 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
172 static int ssh_pkt_ctx
= 0;
174 #define translate(x) if (type == x) return #x
175 #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
176 char *ssh1_pkt_type(int type
)
178 translate(SSH1_MSG_DISCONNECT
);
179 translate(SSH1_SMSG_PUBLIC_KEY
);
180 translate(SSH1_CMSG_SESSION_KEY
);
181 translate(SSH1_CMSG_USER
);
182 translate(SSH1_CMSG_AUTH_RSA
);
183 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE
);
184 translate(SSH1_CMSG_AUTH_RSA_RESPONSE
);
185 translate(SSH1_CMSG_AUTH_PASSWORD
);
186 translate(SSH1_CMSG_REQUEST_PTY
);
187 translate(SSH1_CMSG_WINDOW_SIZE
);
188 translate(SSH1_CMSG_EXEC_SHELL
);
189 translate(SSH1_CMSG_EXEC_CMD
);
190 translate(SSH1_SMSG_SUCCESS
);
191 translate(SSH1_SMSG_FAILURE
);
192 translate(SSH1_CMSG_STDIN_DATA
);
193 translate(SSH1_SMSG_STDOUT_DATA
);
194 translate(SSH1_SMSG_STDERR_DATA
);
195 translate(SSH1_CMSG_EOF
);
196 translate(SSH1_SMSG_EXIT_STATUS
);
197 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
);
198 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE
);
199 translate(SSH1_MSG_CHANNEL_DATA
);
200 translate(SSH1_MSG_CHANNEL_CLOSE
);
201 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
);
202 translate(SSH1_SMSG_X11_OPEN
);
203 translate(SSH1_CMSG_PORT_FORWARD_REQUEST
);
204 translate(SSH1_MSG_PORT_OPEN
);
205 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING
);
206 translate(SSH1_SMSG_AGENT_OPEN
);
207 translate(SSH1_MSG_IGNORE
);
208 translate(SSH1_CMSG_EXIT_CONFIRMATION
);
209 translate(SSH1_CMSG_X11_REQUEST_FORWARDING
);
210 translate(SSH1_CMSG_AUTH_RHOSTS_RSA
);
211 translate(SSH1_MSG_DEBUG
);
212 translate(SSH1_CMSG_REQUEST_COMPRESSION
);
213 translate(SSH1_CMSG_AUTH_TIS
);
214 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE
);
215 translate(SSH1_CMSG_AUTH_TIS_RESPONSE
);
216 translate(SSH1_CMSG_AUTH_CCARD
);
217 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE
);
218 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE
);
221 char *ssh2_pkt_type(int type
)
223 translate(SSH2_MSG_DISCONNECT
);
224 translate(SSH2_MSG_IGNORE
);
225 translate(SSH2_MSG_UNIMPLEMENTED
);
226 translate(SSH2_MSG_DEBUG
);
227 translate(SSH2_MSG_SERVICE_REQUEST
);
228 translate(SSH2_MSG_SERVICE_ACCEPT
);
229 translate(SSH2_MSG_KEXINIT
);
230 translate(SSH2_MSG_NEWKEYS
);
231 translatec(SSH2_MSG_KEXDH_INIT
, SSH2_PKTCTX_DHGROUP1
);
232 translatec(SSH2_MSG_KEXDH_REPLY
, SSH2_PKTCTX_DHGROUP1
);
233 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST
, SSH2_PKTCTX_DHGEX
);
234 translatec(SSH2_MSG_KEX_DH_GEX_GROUP
, SSH2_PKTCTX_DHGEX
);
235 translatec(SSH2_MSG_KEX_DH_GEX_INIT
, SSH2_PKTCTX_DHGEX
);
236 translatec(SSH2_MSG_KEX_DH_GEX_REPLY
, SSH2_PKTCTX_DHGEX
);
237 translate(SSH2_MSG_USERAUTH_REQUEST
);
238 translate(SSH2_MSG_USERAUTH_FAILURE
);
239 translate(SSH2_MSG_USERAUTH_SUCCESS
);
240 translate(SSH2_MSG_USERAUTH_BANNER
);
241 translatec(SSH2_MSG_USERAUTH_PK_OK
, SSH2_PKTCTX_PUBLICKEY
);
242 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
, SSH2_PKTCTX_PASSWORD
);
243 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST
, SSH2_PKTCTX_KBDINTER
);
244 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE
, SSH2_PKTCTX_KBDINTER
);
245 translate(SSH2_MSG_GLOBAL_REQUEST
);
246 translate(SSH2_MSG_REQUEST_SUCCESS
);
247 translate(SSH2_MSG_REQUEST_FAILURE
);
248 translate(SSH2_MSG_CHANNEL_OPEN
);
249 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
250 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
251 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
252 translate(SSH2_MSG_CHANNEL_DATA
);
253 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
254 translate(SSH2_MSG_CHANNEL_EOF
);
255 translate(SSH2_MSG_CHANNEL_CLOSE
);
256 translate(SSH2_MSG_CHANNEL_REQUEST
);
257 translate(SSH2_MSG_CHANNEL_SUCCESS
);
258 translate(SSH2_MSG_CHANNEL_FAILURE
);
264 #define GET_32BIT(cp) \
265 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
266 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
267 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
268 ((unsigned long)(unsigned char)(cp)[3]))
270 #define PUT_32BIT(cp, value) { \
271 (cp)[0] = (unsigned char)((value) >> 24); \
272 (cp)[1] = (unsigned char)((value) >> 16); \
273 (cp)[2] = (unsigned char)((value) >> 8); \
274 (cp)[3] = (unsigned char)(value); }
276 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
278 /* Coroutine mechanics for the sillier bits of the code */
279 #define crBegin1 static int crLine = 0;
280 #define crBegin2 switch(crLine) { case 0:;
281 #define crBegin crBegin1; crBegin2;
282 #define crFinish(z) } crLine = 0; return (z)
283 #define crFinishV } crLine = 0; return
284 #define crReturn(z) \
286 crLine=__LINE__; return (z); case __LINE__:;\
290 crLine=__LINE__; return; case __LINE__:;\
292 #define crStop(z) do{ crLine = 0; return (z); }while(0)
293 #define crStopV do{ crLine = 0; return; }while(0)
294 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
295 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
297 extern char *x11_init(Socket
*, char *, void *);
298 extern void x11_close(Socket
);
299 extern int x11_send(Socket
, char *, int);
300 extern void x11_invent_auth(char *, int, char *, int);
301 extern void x11_unthrottle(Socket s
);
302 extern void x11_override_throttle(Socket s
, int enable
);
304 extern char *pfd_newconnect(Socket
* s
, char *hostname
, int port
, void *c
);
305 extern char *pfd_addforward(char *desthost
, int destport
, int port
);
306 extern void pfd_close(Socket s
);
307 extern int pfd_send(Socket s
, char *data
, int len
);
308 extern void pfd_confirm(Socket s
);
309 extern void pfd_unthrottle(Socket s
);
310 extern void pfd_override_throttle(Socket s
, int enable
);
313 * Buffer management constants. There are several of these for
314 * various different purposes:
316 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
317 * on a local data stream before we throttle the whole SSH
318 * connection (in SSH1 only). Throttling the whole connection is
319 * pretty drastic so we set this high in the hope it won't
322 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
323 * on the SSH connection itself before we defensively throttle
324 * _all_ local data streams. This is pretty drastic too (though
325 * thankfully unlikely in SSH2 since the window mechanism should
326 * ensure that the server never has any need to throttle its end
327 * of the connection), so we set this high as well.
329 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
333 #define SSH1_BUFFER_LIMIT 32768
334 #define SSH_MAX_BACKLOG 32768
335 #define OUR_V2_WINSIZE 16384
337 const static struct ssh_kex
*kex_algs
[] = {
338 &ssh_diffiehellman_gex
,
342 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
344 static void nullmac_key(unsigned char *key
)
347 static void nullmac_generate(unsigned char *blk
, int len
,
351 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
)
355 const static struct ssh_mac ssh_mac_none
= {
356 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
358 const static struct ssh_mac
*macs
[] = {
359 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
361 const static struct ssh_mac
*buggymacs
[] = {
362 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
365 static void ssh_comp_none_init(void)
368 static int ssh_comp_none_block(unsigned char *block
, int len
,
369 unsigned char **outblock
, int *outlen
)
373 static int ssh_comp_none_disable(void)
377 const static struct ssh_compress ssh_comp_none
= {
379 ssh_comp_none_init
, ssh_comp_none_block
,
380 ssh_comp_none_init
, ssh_comp_none_block
,
381 ssh_comp_none_disable
383 extern const struct ssh_compress ssh_zlib
;
384 const static struct ssh_compress
*compressions
[] = {
385 &ssh_zlib
, &ssh_comp_none
388 enum { /* channel types */
393 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
397 * 2-3-4 tree storing channels.
400 unsigned remoteid
, localid
;
404 struct ssh1_data_channel
{
407 struct ssh2_data_channel
{
409 unsigned remwindow
, remmaxpkt
;
414 struct ssh_agent_channel
{
415 unsigned char *message
;
416 unsigned char msglen
[4];
417 int lensofar
, totallen
;
419 struct ssh_x11_channel
{
422 struct ssh_pfd_channel
{
429 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
430 * 2 use this structure in different ways, reflecting SSH 2's
431 * altogether saner approach to port forwarding.
433 * In SSH 1, you arrange a remote forwarding by sending the server
434 * the remote port number, and the local destination host:port.
435 * When a connection comes in, the server sends you back that
436 * host:port pair, and you connect to it. This is a ready-made
437 * security hole if you're not on the ball: a malicious server
438 * could send you back _any_ host:port pair, so if you trustingly
439 * connect to the address it gives you then you've just opened the
440 * entire inside of your corporate network just by connecting
441 * through it to a dodgy SSH server. Hence, we must store a list of
442 * host:port pairs we _are_ trying to forward to, and reject a
443 * connection request from the server if it's not in the list.
445 * In SSH 2, each side of the connection minds its own business and
446 * doesn't send unnecessary information to the other. You arrange a
447 * remote forwarding by sending the server just the remote port
448 * number. When a connection comes in, the server tells you which
449 * of its ports was connected to; and _you_ have to remember what
450 * local host:port pair went with that port number.
452 * Hence: in SSH 1 this structure stores host:port pairs we intend
453 * to allow connections to, and is indexed by those host:port
454 * pairs. In SSH 2 it stores a mapping from source port to
455 * destination host:port pair, and is indexed by source port.
457 struct ssh_rportfwd
{
458 unsigned sport
, dport
;
471 static SHA_State exhash
, exhashbase
;
473 static Socket s
= NULL
;
475 static unsigned char session_key
[32];
476 static int ssh1_compressing
;
477 static int ssh1_remote_protoflags
;
478 static int ssh1_local_protoflags
;
479 static int ssh_agentfwd_enabled
;
480 static int ssh_X11_fwd_enabled
;
481 static int ssh_remote_bugs
;
482 static const struct ssh_cipher
*cipher
= NULL
;
483 static const struct ssh2_cipher
*cscipher
= NULL
;
484 static const struct ssh2_cipher
*sccipher
= NULL
;
485 static const struct ssh_mac
*csmac
= NULL
;
486 static const struct ssh_mac
*scmac
= NULL
;
487 static const struct ssh_compress
*cscomp
= NULL
;
488 static const struct ssh_compress
*sccomp
= NULL
;
489 static const struct ssh_kex
*kex
= NULL
;
490 static const struct ssh_signkey
*hostkey
= NULL
;
491 static unsigned char ssh2_session_id
[20];
492 int (*ssh_get_line
) (const char *prompt
, char *str
, int maxlen
,
495 static char *savedhost
;
496 static int savedport
;
497 static int ssh_send_ok
;
498 static int ssh_echoing
, ssh_editing
;
500 static tree234
*ssh_channels
; /* indexed by local id */
501 static struct ssh_channel
*mainchan
; /* primary session channel */
503 static tree234
*ssh_rportfwds
;
507 SSH_STATE_BEFORE_SIZE
,
511 } ssh_state
= SSH_STATE_PREPACKET
;
513 static int size_needed
= FALSE
, eof_needed
= FALSE
;
515 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
516 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
517 static unsigned char *deferred_send_data
= NULL
;
518 static int deferred_len
= 0, deferred_size
= 0;
521 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
522 * that fails. This variable is the means by which scp.c can reach
523 * into the SSH code and find out which one it got.
525 int ssh_fallback_cmd
= 0;
527 static int ssh_version
;
528 static int ssh1_throttle_count
;
529 static int ssh_overall_bufsize
;
530 static int ssh_throttled_all
;
531 static int ssh1_stdout_throttling
;
532 static void (*ssh_protocol
) (unsigned char *in
, int inlen
, int ispkt
);
533 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
534 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
535 static void ssh_size(void);
536 static void ssh_special(Telnet_Special
);
537 static int ssh2_try_send(struct ssh_channel
*c
);
538 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
540 static void ssh_throttle_all(int enable
, int bufsize
);
541 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
542 static int (*s_rdpkt
) (unsigned char **data
, int *datalen
);
543 static int ssh_sendbuffer(void);
545 static struct rdpkt1_state_tag
{
546 long len
, pad
, biglen
, to_read
;
547 unsigned long realcrc
, gotcrc
;
553 static struct rdpkt2_state_tag
{
554 long len
, pad
, payload
, packetlen
, maclen
;
557 unsigned long incoming_sequence
;
560 static int ssh_channelcmp(void *av
, void *bv
)
562 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
563 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
564 if (a
->localid
< b
->localid
)
566 if (a
->localid
> b
->localid
)
570 static int ssh_channelfind(void *av
, void *bv
)
572 unsigned *a
= (unsigned *) av
;
573 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
581 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
583 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
584 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
586 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
587 return i
< 0 ?
-1 : +1;
588 if (a
->dport
> b
->dport
)
590 if (a
->dport
< b
->dport
)
595 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
597 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
598 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
600 if (a
->sport
> b
->sport
)
602 if (a
->sport
< b
->sport
)
607 static int alloc_channel_id(void)
609 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
610 unsigned low
, high
, mid
;
612 struct ssh_channel
*c
;
615 * First-fit allocation of channel numbers: always pick the
616 * lowest unused one. To do this, binary-search using the
617 * counted B-tree to find the largest channel ID which is in a
618 * contiguous sequence from the beginning. (Precisely
619 * everything in that sequence must have ID equal to its tree
620 * index plus CHANNEL_NUMBER_OFFSET.)
622 tsize
= count234(ssh_channels
);
626 while (high
- low
> 1) {
627 mid
= (high
+ low
) / 2;
628 c
= index234(ssh_channels
, mid
);
629 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
630 low
= mid
; /* this one is fine */
632 high
= mid
; /* this one is past it */
635 * Now low points to either -1, or the tree index of the
636 * largest ID in the initial sequence.
639 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
640 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
642 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
645 static void c_write(char *buf
, int len
)
647 if ((flags
& FLAG_STDERR
)) {
649 for (i
= 0; i
< len
; i
++)
651 fputc(buf
[i
], stderr
);
654 from_backend(1, buf
, len
);
657 static void c_write_untrusted(char *buf
, int len
)
660 for (i
= 0; i
< len
; i
++) {
663 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
668 static void c_write_str(char *buf
)
670 c_write(buf
, strlen(buf
));
674 * Collect incoming data in the incoming packet buffer.
675 * Decipher and verify the packet when it is completely read.
676 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
677 * Update the *data and *datalen variables.
678 * Return the additional nr of bytes needed, or 0 when
679 * a complete packet is available.
681 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
683 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
692 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
693 while ((*datalen
) == 0)
695 st
->len
= (st
->len
<< 8) + **data
;
696 (*data
)++, (*datalen
)--;
699 st
->pad
= 8 - (st
->len
% 8);
700 st
->biglen
= st
->len
+ st
->pad
;
701 pktin
.length
= st
->len
- 5;
703 if (pktin
.maxlen
< st
->biglen
) {
704 pktin
.maxlen
= st
->biglen
;
705 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
706 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
708 fatalbox("Out of memory");
711 st
->to_read
= st
->biglen
;
713 while (st
->to_read
> 0) {
714 st
->chunk
= st
->to_read
;
715 while ((*datalen
) == 0)
716 crReturn(st
->to_read
);
717 if (st
->chunk
> (*datalen
))
718 st
->chunk
= (*datalen
);
719 memcpy(st
->p
, *data
, st
->chunk
);
721 *datalen
-= st
->chunk
;
723 st
->to_read
-= st
->chunk
;
727 cipher
->decrypt(pktin
.data
, st
->biglen
);
729 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
730 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
731 if (st
->gotcrc
!= st
->realcrc
) {
732 bombout(("Incorrect CRC received on packet"));
736 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
738 if (ssh1_compressing
) {
739 unsigned char *decompblk
;
741 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
742 &decompblk
, &decomplen
);
744 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
745 pktin
.maxlen
= st
->pad
+ decomplen
;
746 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
747 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
749 fatalbox("Out of memory");
752 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
754 pktin
.length
= decomplen
- 1;
757 pktin
.type
= pktin
.body
[-1];
759 log_packet(PKT_INCOMING
, pktin
.type
, ssh1_pkt_type(pktin
.type
),
760 pktin
.body
, pktin
.length
);
762 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
763 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
764 pktin
.type
== SSH1_MSG_DEBUG
||
765 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
766 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
767 long strlen
= GET_32BIT(pktin
.body
);
768 if (strlen
+ 4 != pktin
.length
) {
769 bombout(("Received data packet with bogus string length"));
774 if (pktin
.type
== SSH1_MSG_DEBUG
) {
775 /* log debug message */
777 int strlen
= GET_32BIT(pktin
.body
);
778 strcpy(buf
, "Remote: ");
781 memcpy(buf
+ 8, pktin
.body
+ 4, strlen
);
782 buf
[8 + strlen
] = '\0';
785 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
790 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
791 /* log reason code in disconnect message */
793 unsigned msglen
= GET_32BIT(pktin
.body
);
795 strcpy(buf
, "Remote sent disconnect: ");
796 nowlen
= strlen(buf
);
797 if (msglen
> sizeof(buf
) - nowlen
- 1)
798 msglen
= sizeof(buf
) - nowlen
- 1;
799 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
800 buf
[nowlen
+ msglen
] = '\0';
802 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
809 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
811 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
819 st
->cipherblk
= sccipher
->blksize
;
822 if (st
->cipherblk
< 8)
825 if (pktin
.maxlen
< st
->cipherblk
) {
826 pktin
.maxlen
= st
->cipherblk
;
829 NULL ?
smalloc(st
->cipherblk
+
830 APIEXTRA
) : srealloc(pktin
.data
,
834 fatalbox("Out of memory");
838 * Acquire and decrypt the first block of the packet. This will
839 * contain the length and padding details.
841 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
842 while ((*datalen
) == 0)
843 crReturn(st
->cipherblk
- st
->i
);
844 pktin
.data
[st
->i
] = *(*data
)++;
849 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
852 * Now get the length and padding figures.
854 st
->len
= GET_32BIT(pktin
.data
);
855 st
->pad
= pktin
.data
[4];
858 * This enables us to deduce the payload length.
860 st
->payload
= st
->len
- st
->pad
- 1;
862 pktin
.length
= st
->payload
+ 5;
865 * So now we can work out the total packet length.
867 st
->packetlen
= st
->len
+ 4;
868 st
->maclen
= scmac ? scmac
->len
: 0;
871 * Adjust memory allocation if packet is too big.
873 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
874 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
877 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
882 fatalbox("Out of memory");
886 * Read and decrypt the remainder of the packet.
888 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
890 while ((*datalen
) == 0)
891 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
892 pktin
.data
[st
->i
] = *(*data
)++;
895 /* Decrypt everything _except_ the MAC. */
897 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
898 st
->packetlen
- st
->cipherblk
);
904 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
905 st
->incoming_sequence
)) {
906 bombout(("Incorrect MAC received on packet"));
909 st
->incoming_sequence
++; /* whether or not we MACed */
912 * Decompress packet payload.
915 unsigned char *newpayload
;
917 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
918 &newpayload
, &newlen
)) {
919 if (pktin
.maxlen
< newlen
+ 5) {
920 pktin
.maxlen
= newlen
+ 5;
923 NULL ?
smalloc(pktin
.maxlen
+
924 APIEXTRA
) : srealloc(pktin
.data
,
928 fatalbox("Out of memory");
930 pktin
.length
= 5 + newlen
;
931 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
937 pktin
.type
= pktin
.data
[5];
939 log_packet(PKT_INCOMING
, pktin
.type
, ssh2_pkt_type(pktin
.type
),
940 pktin
.data
+6, pktin
.length
-6);
942 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
943 goto next_packet
; /* FIXME: print DEBUG message */
945 if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
946 /* log reason code in disconnect message */
948 int reason
= GET_32BIT(pktin
.data
+ 6);
949 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
951 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
952 sprintf(buf
, "Received disconnect message (%s)",
953 ssh2_disconnect_reasons
[reason
]);
955 sprintf(buf
, "Received disconnect message (unknown type %d)",
959 strcpy(buf
, "Disconnection message text: ");
960 nowlen
= strlen(buf
);
961 if (msglen
> sizeof(buf
) - nowlen
- 1)
962 msglen
= sizeof(buf
) - nowlen
- 1;
963 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
964 buf
[nowlen
+ msglen
] = '\0';
966 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
968 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
969 ssh2_disconnect_reasons
[reason
] : "unknown",
977 static void ssh1_pktout_size(int len
)
981 len
+= 5; /* type and CRC */
985 pktout
.length
= len
- 5;
986 if (pktout
.maxlen
< biglen
) {
987 pktout
.maxlen
= biglen
;
989 /* Allocate enough buffer space for extra block
990 * for MS CryptEncrypt() */
991 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
992 srealloc(pktout
.data
, biglen
+ 12));
994 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
995 srealloc(pktout
.data
, biglen
+ 4));
998 fatalbox("Out of memory");
1000 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
1003 static void s_wrpkt_start(int type
, int len
)
1005 ssh1_pktout_size(len
);
1009 static int s_wrpkt_prepare(void)
1011 int pad
, len
, biglen
, i
;
1014 pktout
.body
[-1] = pktout
.type
;
1016 log_packet(PKT_OUTGOING
, pktout
.type
, ssh1_pkt_type(pktout
.type
),
1017 pktout
.body
, pktout
.length
);
1019 if (ssh1_compressing
) {
1020 unsigned char *compblk
;
1022 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
1023 &compblk
, &complen
);
1024 ssh1_pktout_size(complen
- 1);
1025 memcpy(pktout
.body
- 1, compblk
, complen
);
1029 len
= pktout
.length
+ 5; /* type and CRC */
1030 pad
= 8 - (len
% 8);
1033 for (i
= 0; i
< pad
; i
++)
1034 pktout
.data
[i
+ 4] = random_byte();
1035 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
1036 PUT_32BIT(pktout
.data
+ biglen
, crc
);
1037 PUT_32BIT(pktout
.data
, len
);
1040 cipher
->encrypt(pktout
.data
+ 4, biglen
);
1045 static void s_wrpkt(void)
1048 len
= s_wrpkt_prepare();
1049 backlog
= sk_write(s
, pktout
.data
, len
);
1050 if (backlog
> SSH_MAX_BACKLOG
)
1051 ssh_throttle_all(1, backlog
);
1054 static void s_wrpkt_defer(void)
1057 len
= s_wrpkt_prepare();
1058 if (deferred_len
+ len
> deferred_size
) {
1059 deferred_size
= deferred_len
+ len
+ 128;
1060 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1062 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1063 deferred_len
+= len
;
1067 * Construct a packet with the specified contents.
1069 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1071 unsigned char *p
, *argp
, argchar
;
1072 unsigned long argint
;
1073 int pktlen
, argtype
, arglen
;
1077 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1080 (void) va_arg(ap1
, int);
1084 (void) va_arg(ap1
, char);
1088 (void) va_arg(ap1
, unsigned char *);
1089 arglen
= va_arg(ap1
, int);
1093 argp
= va_arg(ap1
, unsigned char *);
1094 arglen
= strlen(argp
);
1095 pktlen
+= 4 + arglen
;
1098 bn
= va_arg(ap1
, Bignum
);
1099 pktlen
+= ssh1_bignum_length(bn
);
1106 s_wrpkt_start(pkttype
, pktlen
);
1109 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1112 argint
= va_arg(ap2
, int);
1113 PUT_32BIT(p
, argint
);
1117 argchar
= va_arg(ap2
, unsigned char);
1122 argp
= va_arg(ap2
, unsigned char *);
1123 arglen
= va_arg(ap2
, int);
1124 memcpy(p
, argp
, arglen
);
1128 argp
= va_arg(ap2
, unsigned char *);
1129 arglen
= strlen(argp
);
1130 PUT_32BIT(p
, arglen
);
1131 memcpy(p
+ 4, argp
, arglen
);
1135 bn
= va_arg(ap2
, Bignum
);
1136 p
+= ssh1_write_bignum(p
, bn
);
1142 static void send_packet(int pkttype
, ...)
1145 va_start(ap1
, pkttype
);
1146 va_start(ap2
, pkttype
);
1147 construct_packet(pkttype
, ap1
, ap2
);
1151 static void defer_packet(int pkttype
, ...)
1154 va_start(ap1
, pkttype
);
1155 va_start(ap2
, pkttype
);
1156 construct_packet(pkttype
, ap1
, ap2
);
1160 static int ssh_versioncmp(char *a
, char *b
)
1163 unsigned long av
, bv
;
1165 av
= strtoul(a
, &ae
, 10);
1166 bv
= strtoul(b
, &be
, 10);
1168 return (av
< bv ?
-1 : +1);
1173 av
= strtoul(ae
, &ae
, 10);
1174 bv
= strtoul(be
, &be
, 10);
1176 return (av
< bv ?
-1 : +1);
1182 * Utility routines for putting an SSH-protocol `string' and
1183 * `uint32' into a SHA state.
1186 static void sha_string(SHA_State
* s
, void *str
, int len
)
1188 unsigned char lenblk
[4];
1189 PUT_32BIT(lenblk
, len
);
1190 SHA_Bytes(s
, lenblk
, 4);
1191 SHA_Bytes(s
, str
, len
);
1194 static void sha_uint32(SHA_State
* s
, unsigned i
)
1196 unsigned char intblk
[4];
1197 PUT_32BIT(intblk
, i
);
1198 SHA_Bytes(s
, intblk
, 4);
1202 * SSH2 packet construction functions.
1204 static void ssh2_pkt_ensure(int length
)
1206 if (pktout
.maxlen
< length
) {
1207 pktout
.maxlen
= length
+ 256;
1210 NULL ?
smalloc(pktout
.maxlen
+
1211 APIEXTRA
) : srealloc(pktout
.data
,
1215 fatalbox("Out of memory");
1218 static void ssh2_pkt_adddata(void *data
, int len
)
1220 pktout
.length
+= len
;
1221 ssh2_pkt_ensure(pktout
.length
);
1222 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1224 static void ssh2_pkt_addbyte(unsigned char byte
)
1226 ssh2_pkt_adddata(&byte
, 1);
1228 static void ssh2_pkt_init(int pkt_type
)
1231 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1233 static void ssh2_pkt_addbool(unsigned char value
)
1235 ssh2_pkt_adddata(&value
, 1);
1237 static void ssh2_pkt_adduint32(unsigned long value
)
1240 PUT_32BIT(x
, value
);
1241 ssh2_pkt_adddata(x
, 4);
1243 static void ssh2_pkt_addstring_start(void)
1245 ssh2_pkt_adduint32(0);
1246 pktout
.savedpos
= pktout
.length
;
1248 static void ssh2_pkt_addstring_str(char *data
)
1250 ssh2_pkt_adddata(data
, strlen(data
));
1251 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1252 pktout
.length
- pktout
.savedpos
);
1254 static void ssh2_pkt_addstring_data(char *data
, int len
)
1256 ssh2_pkt_adddata(data
, len
);
1257 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1258 pktout
.length
- pktout
.savedpos
);
1260 static void ssh2_pkt_addstring(char *data
)
1262 ssh2_pkt_addstring_start();
1263 ssh2_pkt_addstring_str(data
);
1265 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1268 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1271 fatalbox("out of memory");
1273 for (i
= 1; i
<= n
; i
++)
1274 p
[i
] = bignum_byte(b
, n
- i
);
1276 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1278 memmove(p
, p
+ i
, n
+ 1 - i
);
1282 static void ssh2_pkt_addmp(Bignum b
)
1286 p
= ssh2_mpint_fmt(b
, &len
);
1287 ssh2_pkt_addstring_start();
1288 ssh2_pkt_addstring_data(p
, len
);
1293 * Construct an SSH2 final-form packet: compress it, encrypt it,
1294 * put the MAC on it. Final packet, ready to be sent, is stored in
1295 * pktout.data. Total length is returned.
1297 static int ssh2_pkt_construct(void)
1299 int cipherblk
, maclen
, padding
, i
;
1300 static unsigned long outgoing_sequence
= 0;
1302 log_packet(PKT_OUTGOING
, pktout
.data
[5], ssh2_pkt_type(pktout
.data
[5]),
1303 pktout
.data
+ 6, pktout
.length
- 6);
1306 * Compress packet payload.
1309 unsigned char *newpayload
;
1311 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1312 &newpayload
, &newlen
)) {
1314 ssh2_pkt_adddata(newpayload
, newlen
);
1320 * Add padding. At least four bytes, and must also bring total
1321 * length (minus MAC) up to a multiple of the block size.
1323 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1324 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1327 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1328 maclen
= csmac ? csmac
->len
: 0;
1329 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1330 pktout
.data
[4] = padding
;
1331 for (i
= 0; i
< padding
; i
++)
1332 pktout
.data
[pktout
.length
+ i
] = random_byte();
1333 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1335 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1337 outgoing_sequence
++; /* whether or not we MACed */
1340 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1342 /* Ready-to-send packet starts at pktout.data. We return length. */
1343 return pktout
.length
+ padding
+ maclen
;
1347 * Construct and send an SSH2 packet immediately.
1349 static void ssh2_pkt_send(void)
1353 len
= ssh2_pkt_construct();
1354 backlog
= sk_write(s
, pktout
.data
, len
);
1355 if (backlog
> SSH_MAX_BACKLOG
)
1356 ssh_throttle_all(1, backlog
);
1360 * Construct an SSH2 packet and add it to a deferred data block.
1361 * Useful for sending multiple packets in a single sk_write() call,
1362 * to prevent a traffic-analysing listener from being able to work
1363 * out the length of any particular packet (such as the password
1366 * Note that because SSH2 sequence-numbers its packets, this can
1367 * NOT be used as an m4-style `defer' allowing packets to be
1368 * constructed in one order and sent in another.
1370 static void ssh2_pkt_defer(void)
1372 int len
= ssh2_pkt_construct();
1373 if (deferred_len
+ len
> deferred_size
) {
1374 deferred_size
= deferred_len
+ len
+ 128;
1375 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1377 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1378 deferred_len
+= len
;
1382 * Send the whole deferred data block constructed by
1383 * ssh2_pkt_defer() or SSH1's defer_packet().
1385 static void ssh_pkt_defersend(void)
1388 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1389 deferred_len
= deferred_size
= 0;
1390 sfree(deferred_send_data
);
1391 deferred_send_data
= NULL
;
1392 if (backlog
> SSH_MAX_BACKLOG
)
1393 ssh_throttle_all(1, backlog
);
1397 void bndebug(char *string
, Bignum b
)
1401 p
= ssh2_mpint_fmt(b
, &len
);
1402 debug(("%s", string
));
1403 for (i
= 0; i
< len
; i
++)
1404 debug((" %02x", p
[i
]));
1410 static void sha_mpint(SHA_State
* s
, Bignum b
)
1414 p
= ssh2_mpint_fmt(b
, &len
);
1415 sha_string(s
, p
, len
);
1420 * SSH2 packet decode functions.
1422 static unsigned long ssh2_pkt_getuint32(void)
1424 unsigned long value
;
1425 if (pktin
.length
- pktin
.savedpos
< 4)
1426 return 0; /* arrgh, no way to decline (FIXME?) */
1427 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1428 pktin
.savedpos
+= 4;
1431 static int ssh2_pkt_getbool(void)
1433 unsigned long value
;
1434 if (pktin
.length
- pktin
.savedpos
< 1)
1435 return 0; /* arrgh, no way to decline (FIXME?) */
1436 value
= pktin
.data
[pktin
.savedpos
] != 0;
1440 static void ssh2_pkt_getstring(char **p
, int *length
)
1443 if (pktin
.length
- pktin
.savedpos
< 4)
1445 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1446 pktin
.savedpos
+= 4;
1447 if (pktin
.length
- pktin
.savedpos
< *length
)
1449 *p
= pktin
.data
+ pktin
.savedpos
;
1450 pktin
.savedpos
+= *length
;
1452 static Bignum
ssh2_pkt_getmp(void)
1458 ssh2_pkt_getstring(&p
, &length
);
1462 bombout(("internal error: Can't handle negative mpints"));
1465 b
= bignum_from_bytes(p
, length
);
1470 * Examine the remote side's version string and compare it against
1471 * a list of known buggy implementations.
1473 static void ssh_detect_bugs(char *vstring
)
1475 char *imp
; /* pointer to implementation part */
1477 imp
+= strcspn(imp
, "-");
1479 imp
+= strcspn(imp
, "-");
1482 ssh_remote_bugs
= 0;
1484 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1485 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1486 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1488 * These versions don't support SSH1_MSG_IGNORE, so we have
1489 * to use a different defence against password length
1492 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1493 logevent("We believe remote version has SSH1 ignore bug");
1496 if (!strcmp(imp
, "Cisco-1.25")) {
1498 * These versions need a plain password sent; they can't
1499 * handle having a null and a random length of data after
1502 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1503 logevent("We believe remote version needs a plain SSH1 password");
1506 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1507 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1508 !strncmp(imp
, "2.1 ", 4)) {
1510 * These versions have the HMAC bug.
1512 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1513 logevent("We believe remote version has SSH2 HMAC bug");
1517 static int do_ssh_init(unsigned char c
)
1520 static char version
[10];
1521 static char *vstring
;
1522 static int vstrsize
;
1528 /* Search for the string "SSH-" in the input. */
1531 static const int transS
[] = { 1, 2, 2, 1 };
1532 static const int transH
[] = { 0, 0, 3, 0 };
1533 static const int transminus
[] = { 0, 0, 0, -1 };
1544 crReturn(1); /* get another character */
1548 vstring
= smalloc(vstrsize
);
1549 strcpy(vstring
, "SSH-");
1553 crReturn(1); /* get another char */
1554 if (vslen
>= vstrsize
- 1) {
1556 vstring
= srealloc(vstring
, vstrsize
);
1558 vstring
[vslen
++] = c
;
1563 } else if (i
< sizeof(version
) - 1)
1565 } else if (c
== '\n')
1569 ssh_agentfwd_enabled
= FALSE
;
1570 rdpkt2_state
.incoming_sequence
= 0;
1573 vlog
= smalloc(20 + vslen
);
1574 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1575 sprintf(vlog
, "Server version: %s", vstring
);
1577 ssh_detect_bugs(vstring
);
1581 * Server version "1.99" means we can choose whether we use v1
1582 * or v2 protocol. Choice is based on cfg.sshprot.
1584 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1586 * This is a v2 server. Begin v2 protocol.
1588 char verstring
[80], vlog
[100];
1589 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1590 SHA_Init(&exhashbase
);
1592 * Hash our version string and their version string.
1594 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1595 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1596 sprintf(vlog
, "We claim version: %s", verstring
);
1598 strcat(verstring
, "\n");
1599 logevent("Using SSH protocol version 2");
1600 sk_write(s
, verstring
, strlen(verstring
));
1601 ssh_protocol
= ssh2_protocol
;
1603 s_rdpkt
= ssh2_rdpkt
;
1606 * This is a v1 server. Begin v1 protocol.
1608 char verstring
[80], vlog
[100];
1609 sprintf(verstring
, "SSH-%s-%s",
1610 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1612 sprintf(vlog
, "We claim version: %s", verstring
);
1614 strcat(verstring
, "\n");
1615 logevent("Using SSH protocol version 1");
1616 sk_write(s
, verstring
, strlen(verstring
));
1617 ssh_protocol
= ssh1_protocol
;
1619 s_rdpkt
= ssh1_rdpkt
;
1621 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1628 static void ssh_gotdata(unsigned char *data
, int datalen
)
1633 * To begin with, feed the characters one by one to the
1634 * protocol initialisation / selection function do_ssh_init().
1635 * When that returns 0, we're done with the initial greeting
1636 * exchange and can move on to packet discipline.
1641 crReturnV
; /* more data please */
1642 ret
= do_ssh_init(*data
);
1650 * We emerge from that loop when the initial negotiation is
1651 * over and we have selected an s_rdpkt function. Now pass
1652 * everything to s_rdpkt, and then pass the resulting packets
1653 * to the proper protocol handler.
1658 while (datalen
> 0) {
1659 if (s_rdpkt(&data
, &datalen
) == 0) {
1660 if (ssh_state
== SSH_STATE_CLOSED
) {
1663 ssh_protocol(NULL
, 0, 1);
1664 if (ssh_state
== SSH_STATE_CLOSED
) {
1674 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1677 ssh_state
= SSH_STATE_CLOSED
;
1683 /* A socket error has occurred. */
1684 connection_fatal(error_msg
);
1686 /* Otherwise, the remote side closed the connection normally. */
1691 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1693 ssh_gotdata(data
, len
);
1694 if (ssh_state
== SSH_STATE_CLOSED
) {
1704 static void ssh_sent(Plug plug
, int bufsize
)
1707 * If the send backlog on the SSH socket itself clears, we
1708 * should unthrottle the whole world if it was throttled.
1710 if (bufsize
< SSH_MAX_BACKLOG
)
1711 ssh_throttle_all(0, bufsize
);
1715 * Connect to specified host and port.
1716 * Returns an error message, or NULL on success.
1717 * Also places the canonical host name into `realhost'. It must be
1718 * freed by the caller.
1720 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1722 static struct plug_function_table fn_table
= {
1727 }, *fn_table_ptr
= &fn_table
;
1736 savedhost
= smalloc(1 + strlen(host
));
1738 fatalbox("Out of memory");
1739 strcpy(savedhost
, host
);
1742 port
= 22; /* default ssh port */
1757 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1760 addr
= sk_namelookup(host
, realhost
);
1761 if ((err
= sk_addr_error(addr
)))
1765 *realhost
= strdup(FWhost
);
1772 char buf
[200], addrbuf
[100];
1773 sk_getaddr(addr
, addrbuf
, 100);
1774 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1777 s
= sk_new(addr
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1778 if ((err
= sk_socket_error(s
)))
1782 sk_write(s
, "connect ", 8);
1783 sk_write(s
, FWhost
, strlen(FWhost
));
1786 sprintf(buf
, " %d\n", FWport
);
1787 sk_write(s
, buf
, strlen(buf
));
1795 * Throttle or unthrottle the SSH connection.
1797 static void ssh1_throttle(int adjust
)
1799 int old_count
= ssh1_throttle_count
;
1800 ssh1_throttle_count
+= adjust
;
1801 assert(ssh1_throttle_count
>= 0);
1802 if (ssh1_throttle_count
&& !old_count
) {
1803 sk_set_frozen(s
, 1);
1804 } else if (!ssh1_throttle_count
&& old_count
) {
1805 sk_set_frozen(s
, 0);
1810 * Throttle or unthrottle _all_ local data streams (for when sends
1811 * on the SSH connection itself back up).
1813 static void ssh_throttle_all(int enable
, int bufsize
)
1816 struct ssh_channel
*c
;
1818 if (enable
== ssh_throttled_all
)
1820 ssh_throttled_all
= enable
;
1821 ssh_overall_bufsize
= bufsize
;
1824 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
1826 case CHAN_MAINSESSION
:
1828 * This is treated separately, outside the switch.
1832 x11_override_throttle(c
->u
.x11
.s
, enable
);
1835 /* Agent channels require no buffer management. */
1838 pfd_override_throttle(c
->u
.x11
.s
, enable
);
1845 * Handle the key exchange and user authentication phases.
1847 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1851 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
1852 unsigned char cookie
[8];
1853 struct RSAKey servkey
, hostkey
;
1854 struct MD5Context md5c
;
1855 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1856 static int tried_publickey
;
1857 static int tis_auth_refused
, ccard_auth_refused
;
1858 static unsigned char session_id
[16];
1859 static int cipher_type
;
1860 static char username
[100];
1867 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1868 bombout(("Public key packet not received"));
1872 logevent("Received public keys");
1874 memcpy(cookie
, pktin
.body
, 8);
1876 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1877 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
1880 * Log the host key fingerprint.
1884 logevent("Host key fingerprint is:");
1885 strcpy(logmsg
, " ");
1886 hostkey
.comment
= NULL
;
1887 rsa_fingerprint(logmsg
+ strlen(logmsg
),
1888 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
1892 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
1893 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
1894 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
1896 ssh1_local_protoflags
=
1897 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1898 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1901 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1902 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1903 MD5Update(&md5c
, pktin
.body
, 8);
1904 MD5Final(session_id
, &md5c
);
1906 for (i
= 0; i
< 32; i
++)
1907 session_key
[i
] = random_byte();
1909 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1911 rsabuf
= smalloc(len
);
1913 fatalbox("Out of memory");
1916 * Verify the host key.
1920 * First format the key into a string.
1922 int len
= rsastr_len(&hostkey
);
1923 char fingerprint
[100];
1924 char *keystr
= smalloc(len
);
1926 fatalbox("Out of memory");
1927 rsastr_fmt(keystr
, &hostkey
);
1928 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1929 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
1934 for (i
= 0; i
< 32; i
++) {
1935 rsabuf
[i
] = session_key
[i
];
1937 rsabuf
[i
] ^= session_id
[i
];
1940 if (hostkey
.bytes
> servkey
.bytes
) {
1941 rsaencrypt(rsabuf
, 32, &servkey
);
1942 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1944 rsaencrypt(rsabuf
, 32, &hostkey
);
1945 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1948 logevent("Encrypted session key");
1951 int cipher_chosen
= 0, warn
= 0;
1952 char *cipher_string
= NULL
;
1953 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
1954 int next_cipher
= cfg
.ssh_cipherlist
[i
];
1955 if (next_cipher
== CIPHER_WARN
) {
1956 /* If/when we choose a cipher, warn about it */
1958 } else if (next_cipher
== CIPHER_AES
) {
1959 /* XXX Probably don't need to mention this. */
1960 logevent("AES not supported in SSH1, skipping");
1962 switch (next_cipher
) {
1963 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
1964 cipher_string
= "3DES"; break;
1965 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
1966 cipher_string
= "Blowfish"; break;
1967 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
1968 cipher_string
= "single-DES"; break;
1970 if (supported_ciphers_mask
& (1 << cipher_type
))
1974 if (!cipher_chosen
) {
1975 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
1976 bombout(("Server violates SSH 1 protocol by not "
1977 "supporting 3DES encryption"));
1979 /* shouldn't happen */
1980 bombout(("No supported ciphers found"));
1984 /* Warn about chosen cipher if necessary. */
1986 askcipher(cipher_string
, 0);
1989 switch (cipher_type
) {
1990 case SSH_CIPHER_3DES
:
1991 logevent("Using 3DES encryption");
1993 case SSH_CIPHER_DES
:
1994 logevent("Using single-DES encryption");
1996 case SSH_CIPHER_BLOWFISH
:
1997 logevent("Using Blowfish encryption");
2001 send_packet(SSH1_CMSG_SESSION_KEY
,
2002 PKT_CHAR
, cipher_type
,
2003 PKT_DATA
, cookie
, 8,
2004 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
2005 PKT_DATA
, rsabuf
, len
,
2006 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
2008 logevent("Trying to enable encryption...");
2012 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2013 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
2014 cipher
->sesskey(session_key
);
2018 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2019 bombout(("Encryption not successfully enabled"));
2023 logevent("Successfully started encryption");
2029 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2031 if (!ssh_get_line("login as: ",
2032 username
, sizeof(username
), FALSE
)) {
2034 * get_line failed to get a username.
2037 logevent("No username provided. Abandoning session.");
2038 ssh_state
= SSH_STATE_CLOSED
;
2042 c_write_str("login as: ");
2045 crWaitUntil(!ispkt
);
2047 switch (c
= *in
++) {
2056 c_write_str("\b \b");
2063 c_write_str("\b \b");
2073 if (((c
>= ' ' && c
<= '~') ||
2074 ((unsigned char) c
>= 160))
2075 && pos
< sizeof(username
)-1) {
2076 username
[pos
++] = c
;
2082 c_write_str("\r\n");
2083 username
[strcspn(username
, "\n\r")] = '\0';
2086 strncpy(username
, cfg
.username
, 99);
2087 username
[99] = '\0';
2090 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2092 char userlog
[22 + sizeof(username
)];
2093 sprintf(userlog
, "Sent username \"%s\"", username
);
2095 if (flags
& FLAG_INTERACTIVE
&&
2096 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2097 strcat(userlog
, "\r\n");
2098 c_write_str(userlog
);
2105 tried_publickey
= 0;
2106 tis_auth_refused
= ccard_auth_refused
= 0;
2108 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2109 static char password
[100];
2110 static char prompt
[200];
2113 static int pwpkt_type
;
2114 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2116 if (agent_exists()) {
2118 * Attempt RSA authentication using Pageant.
2120 static unsigned char request
[5], *response
, *p
;
2121 static int responselen
;
2122 static int i
, nkeys
;
2123 static int authed
= FALSE
;
2126 logevent("Pageant is running. Requesting keys.");
2128 /* Request the keys held by the agent. */
2129 PUT_32BIT(request
, 1);
2130 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2131 agent_query(request
, 5, &r
, &responselen
);
2132 response
= (unsigned char *) r
;
2133 if (response
&& responselen
>= 5 &&
2134 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2136 nkeys
= GET_32BIT(p
);
2140 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2143 for (i
= 0; i
< nkeys
; i
++) {
2144 static struct RSAKey key
;
2145 static Bignum challenge
;
2146 static char *commentp
;
2147 static int commentlen
;
2151 sprintf(buf
, "Trying Pageant key #%d", i
);
2155 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2156 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2157 commentlen
= GET_32BIT(p
);
2161 send_packet(SSH1_CMSG_AUTH_RSA
,
2162 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2164 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2165 logevent("Key refused");
2168 logevent("Received RSA challenge");
2169 ssh1_read_bignum(pktin
.body
, &challenge
);
2171 char *agentreq
, *q
, *ret
;
2174 len
= 1 + 4; /* message type, bit count */
2175 len
+= ssh1_bignum_length(key
.exponent
);
2176 len
+= ssh1_bignum_length(key
.modulus
);
2177 len
+= ssh1_bignum_length(challenge
);
2178 len
+= 16; /* session id */
2179 len
+= 4; /* response format */
2180 agentreq
= smalloc(4 + len
);
2181 PUT_32BIT(agentreq
, len
);
2183 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2184 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2186 q
+= ssh1_write_bignum(q
, key
.exponent
);
2187 q
+= ssh1_write_bignum(q
, key
.modulus
);
2188 q
+= ssh1_write_bignum(q
, challenge
);
2189 memcpy(q
, session_id
, 16);
2191 PUT_32BIT(q
, 1); /* response format */
2192 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2196 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2197 logevent("Sending Pageant's response");
2198 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2199 PKT_DATA
, ret
+ 5, 16,
2203 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2205 ("Pageant's response accepted");
2206 if (flags
& FLAG_VERBOSE
) {
2208 ("Authenticated using RSA key \"");
2209 c_write(commentp
, commentlen
);
2210 c_write_str("\" from agent\r\n");
2215 ("Pageant's response not accepted");
2218 ("Pageant failed to answer challenge");
2222 logevent("No reply received from Pageant");
2225 freebn(key
.exponent
);
2226 freebn(key
.modulus
);
2235 if (*cfg
.keyfile
&& !tried_publickey
)
2236 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2238 if (cfg
.try_tis_auth
&&
2239 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2240 !tis_auth_refused
) {
2241 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2242 logevent("Requested TIS authentication");
2243 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2245 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2246 logevent("TIS authentication declined");
2247 if (flags
& FLAG_INTERACTIVE
)
2248 c_write_str("TIS authentication refused.\r\n");
2249 tis_auth_refused
= 1;
2252 int challengelen
= ((pktin
.body
[0] << 24) |
2253 (pktin
.body
[1] << 16) |
2254 (pktin
.body
[2] << 8) |
2256 logevent("Received TIS challenge");
2257 if (challengelen
> sizeof(prompt
) - 1)
2258 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2259 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2260 /* Prompt heuristic comes from OpenSSH */
2261 strncpy(prompt
+ challengelen
,
2262 memchr(prompt
, '\n', challengelen
) ?
2263 "": "\r\nResponse: ",
2264 (sizeof prompt
) - challengelen
);
2265 prompt
[(sizeof prompt
) - 1] = '\0';
2268 if (cfg
.try_tis_auth
&&
2269 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2270 !ccard_auth_refused
) {
2271 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2272 logevent("Requested CryptoCard authentication");
2273 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2275 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2276 logevent("CryptoCard authentication declined");
2277 c_write_str("CryptoCard authentication refused.\r\n");
2278 ccard_auth_refused
= 1;
2281 int challengelen
= ((pktin
.body
[0] << 24) |
2282 (pktin
.body
[1] << 16) |
2283 (pktin
.body
[2] << 8) |
2285 logevent("Received CryptoCard challenge");
2286 if (challengelen
> sizeof(prompt
) - 1)
2287 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2288 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2289 strncpy(prompt
+ challengelen
,
2290 memchr(prompt
, '\n', challengelen
) ?
2291 "" : "\r\nResponse: ",
2292 sizeof(prompt
) - challengelen
);
2293 prompt
[sizeof(prompt
) - 1] = '\0';
2296 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2297 sprintf(prompt
, "%.90s@%.90s's password: ",
2298 username
, savedhost
);
2300 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2301 char *comment
= NULL
;
2302 if (flags
& FLAG_VERBOSE
)
2303 c_write_str("Trying public key authentication.\r\n");
2304 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2305 if (flags
& FLAG_VERBOSE
)
2306 c_write_str("No passphrase required.\r\n");
2309 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2314 * Show password prompt, having first obtained it via a TIS
2315 * or CryptoCard exchange if we're doing TIS or CryptoCard
2319 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2321 * get_line failed to get a password (for example
2322 * because one was supplied on the command line
2323 * which has already failed to work). Terminate.
2325 send_packet(SSH1_MSG_DISCONNECT
,
2326 PKT_STR
, "No more passwords available to try",
2328 connection_fatal("Unable to authenticate");
2329 ssh_state
= SSH_STATE_CLOSED
;
2333 /* Prompt may have come from server. We've munged it a bit, so
2334 * we know it to be zero-terminated at least once. */
2335 c_write_untrusted(prompt
, strlen(prompt
));
2339 crWaitUntil(!ispkt
);
2341 switch (c
= *in
++) {
2362 if (pos
< sizeof(password
)-1)
2363 password
[pos
++] = c
;
2367 c_write_str("\r\n");
2371 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2373 * Try public key authentication with the specified
2376 static struct RSAKey pubkey
;
2377 static Bignum challenge
, response
;
2379 static unsigned char buffer
[32];
2381 tried_publickey
= 1;
2382 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2384 c_write_str("Couldn't load private key from ");
2385 c_write_str(cfg
.keyfile
);
2386 c_write_str(".\r\n");
2387 continue; /* go and try password */
2390 c_write_str("Wrong passphrase.\r\n");
2391 tried_publickey
= 0;
2392 continue; /* try again */
2396 * Send a public key attempt.
2398 send_packet(SSH1_CMSG_AUTH_RSA
,
2399 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2402 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2403 c_write_str("Server refused our public key.\r\n");
2404 continue; /* go and try password */
2406 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2407 bombout(("Bizarre response to offer of public key"));
2410 ssh1_read_bignum(pktin
.body
, &challenge
);
2411 response
= rsadecrypt(challenge
, &pubkey
);
2412 freebn(pubkey
.private_exponent
); /* burn the evidence */
2414 for (i
= 0; i
< 32; i
++) {
2415 buffer
[i
] = bignum_byte(response
, 31 - i
);
2419 MD5Update(&md5c
, buffer
, 32);
2420 MD5Update(&md5c
, session_id
, 16);
2421 MD5Final(buffer
, &md5c
);
2423 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2424 PKT_DATA
, buffer
, 16, PKT_END
);
2427 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2428 if (flags
& FLAG_VERBOSE
)
2430 ("Failed to authenticate with our public key.\r\n");
2431 continue; /* go and try password */
2432 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2434 ("Bizarre response to RSA authentication response"));
2438 break; /* we're through! */
2440 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2442 * Defence against traffic analysis: we send a
2443 * whole bunch of packets containing strings of
2444 * different lengths. One of these strings is the
2445 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2446 * The others are all random data in
2447 * SSH1_MSG_IGNORE packets. This way a passive
2448 * listener can't tell which is the password, and
2449 * hence can't deduce the password length.
2451 * Anybody with a password length greater than 16
2452 * bytes is going to have enough entropy in their
2453 * password that a listener won't find it _that_
2454 * much help to know how long it is. So what we'll
2457 * - if password length < 16, we send 15 packets
2458 * containing string lengths 1 through 15
2460 * - otherwise, we let N be the nearest multiple
2461 * of 8 below the password length, and send 8
2462 * packets containing string lengths N through
2463 * N+7. This won't obscure the order of
2464 * magnitude of the password length, but it will
2465 * introduce a bit of extra uncertainty.
2467 * A few servers (the old 1.2.18 through 1.2.22)
2468 * can't deal with SSH1_MSG_IGNORE. For these
2469 * servers, we need an alternative defence. We make
2470 * use of the fact that the password is interpreted
2471 * as a C string: so we can append a NUL, then some
2474 * One server (a Cisco one) can deal with neither
2475 * SSH1_MSG_IGNORE _nor_ a padded password string.
2476 * For this server we are left with no defences
2477 * against password length sniffing.
2479 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2481 * The server can deal with SSH1_MSG_IGNORE, so
2482 * we can use the primary defence.
2484 int bottom
, top
, pwlen
, i
;
2487 pwlen
= strlen(password
);
2489 bottom
= 0; /* zero length passwords are OK! :-) */
2492 bottom
= pwlen
& ~7;
2496 assert(pwlen
>= bottom
&& pwlen
<= top
);
2498 randomstr
= smalloc(top
+ 1);
2500 for (i
= bottom
; i
<= top
; i
++) {
2502 defer_packet(pwpkt_type
, PKT_STR
, password
,
2505 for (j
= 0; j
< i
; j
++) {
2507 randomstr
[j
] = random_byte();
2508 } while (randomstr
[j
] == '\0');
2510 randomstr
[i
] = '\0';
2511 defer_packet(SSH1_MSG_IGNORE
,
2512 PKT_STR
, randomstr
, PKT_END
);
2515 logevent("Sending password with camouflage packets");
2516 ssh_pkt_defersend();
2518 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2520 * The server can't deal with SSH1_MSG_IGNORE
2521 * but can deal with padded passwords, so we
2522 * can use the secondary defence.
2528 len
= strlen(password
);
2529 if (len
< sizeof(string
)) {
2531 strcpy(string
, password
);
2532 len
++; /* cover the zero byte */
2533 while (len
< sizeof(string
)) {
2534 string
[len
++] = (char) random_byte();
2539 logevent("Sending length-padded password");
2540 send_packet(pwpkt_type
, PKT_INT
, len
,
2541 PKT_DATA
, s
, len
, PKT_END
);
2544 * The server has _both_
2545 * BUG_CHOKES_ON_SSH1_IGNORE and
2546 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2547 * therefore nothing we can do.
2550 len
= strlen(password
);
2551 logevent("Sending unpadded password");
2552 send_packet(pwpkt_type
, PKT_INT
, len
,
2553 PKT_DATA
, password
, len
, PKT_END
);
2556 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2559 logevent("Sent password");
2560 memset(password
, 0, strlen(password
));
2562 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2563 if (flags
& FLAG_VERBOSE
)
2564 c_write_str("Access denied\r\n");
2565 logevent("Authentication refused");
2566 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2567 logevent("Received disconnect request");
2568 ssh_state
= SSH_STATE_CLOSED
;
2570 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2571 bombout(("Strange packet received, type %d", pktin
.type
));
2576 logevent("Authentication successful");
2581 void sshfwd_close(struct ssh_channel
*c
)
2583 if (c
&& !c
->closes
) {
2585 * If the channel's remoteid is -1, we have sent
2586 * CHANNEL_OPEN for this channel, but it hasn't even been
2587 * acknowledged by the server. So we must set a close flag
2588 * on it now, and then when the server acks the channel
2589 * open, we can close it then.
2591 if (c
->remoteid
!= -1) {
2592 if (ssh_version
== 1) {
2593 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2596 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2597 ssh2_pkt_adduint32(c
->remoteid
);
2602 if (c
->type
== CHAN_X11
) {
2604 logevent("Forwarded X11 connection terminated");
2605 } else if (c
->type
== CHAN_SOCKDATA
||
2606 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2608 logevent("Forwarded port closed");
2613 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2615 if (ssh_version
== 1) {
2616 send_packet(SSH1_MSG_CHANNEL_DATA
,
2617 PKT_INT
, c
->remoteid
,
2618 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2620 * In SSH1 we can return 0 here - implying that forwarded
2621 * connections are never individually throttled - because
2622 * the only circumstance that can cause throttling will be
2623 * the whole SSH connection backing up, in which case
2624 * _everything_ will be throttled as a whole.
2628 ssh2_add_channel_data(c
, buf
, len
);
2629 return ssh2_try_send(c
);
2633 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2635 if (ssh_version
== 1) {
2636 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2637 c
->v
.v1
.throttling
= 0;
2641 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2645 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2651 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2654 if (ssh_state
== SSH_STATE_CLOSED
)
2657 if (cfg
.agentfwd
&& agent_exists()) {
2658 logevent("Requesting agent forwarding");
2659 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2663 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2664 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2665 bombout(("Protocol confusion"));
2667 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2668 logevent("Agent forwarding refused");
2670 logevent("Agent forwarding enabled");
2671 ssh_agentfwd_enabled
= TRUE
;
2675 if (cfg
.x11_forward
) {
2676 char proto
[20], data
[64];
2677 logevent("Requesting X11 forwarding");
2678 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2679 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2680 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2681 PKT_STR
, proto
, PKT_STR
, data
,
2682 PKT_INT
, 0, PKT_END
);
2684 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2685 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2690 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2691 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2692 bombout(("Protocol confusion"));
2694 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2695 logevent("X11 forwarding refused");
2697 logevent("X11 forwarding enabled");
2698 ssh_X11_fwd_enabled
= TRUE
;
2706 char sports
[256], dports
[256], host
[256];
2709 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2710 /* Add port forwardings. */
2715 while (*e
&& *e
!= '\t')
2721 while (*e
&& *e
!= ':')
2731 dport
= atoi(dports
);
2732 sport
= atoi(sports
);
2733 if (sport
&& dport
) {
2735 pfd_addforward(host
, dport
, sport
);
2736 sprintf(buf
, "Local port %d forwarding to %s:%d",
2737 sport
, host
, dport
);
2740 struct ssh_rportfwd
*pf
;
2741 pf
= smalloc(sizeof(*pf
));
2742 strcpy(pf
->dhost
, host
);
2744 if (add234(ssh_rportfwds
, pf
) != pf
) {
2746 "Duplicate remote port forwarding to %s:%d",
2751 sprintf(buf
, "Requesting remote port %d forward to %s:%d",
2752 sport
, host
, dport
);
2754 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2766 send_packet(SSH1_CMSG_REQUEST_PTY
,
2767 PKT_STR
, cfg
.termtype
,
2768 PKT_INT
, rows
, PKT_INT
, cols
,
2769 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2770 ssh_state
= SSH_STATE_INTERMED
;
2774 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2775 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2776 bombout(("Protocol confusion"));
2778 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2779 c_write_str("Server refused to allocate pty\r\n");
2780 ssh_editing
= ssh_echoing
= 1;
2782 logevent("Allocated pty");
2784 ssh_editing
= ssh_echoing
= 1;
2787 if (cfg
.compression
) {
2788 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2792 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2793 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2794 bombout(("Protocol confusion"));
2796 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2797 c_write_str("Server refused to compress\r\n");
2799 logevent("Started compression");
2800 ssh1_compressing
= TRUE
;
2801 zlib_compress_init();
2802 zlib_decompress_init();
2806 * Start the shell or command.
2808 * Special case: if the first-choice command is an SSH2
2809 * subsystem (hence not usable here) and the second choice
2810 * exists, we fall straight back to that.
2813 char *cmd
= cfg
.remote_cmd_ptr
;
2815 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
2816 cmd
= cfg
.remote_cmd_ptr2
;
2817 ssh_fallback_cmd
= TRUE
;
2820 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2822 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2823 logevent("Started session");
2826 ssh_state
= SSH_STATE_SESSION
;
2830 ssh_special(TS_EOF
);
2832 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
2834 ssh_channels
= newtree234(ssh_channelcmp
);
2838 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2839 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2840 long len
= GET_32BIT(pktin
.body
);
2842 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2843 pktin
.body
+ 4, len
);
2844 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2845 ssh1_stdout_throttling
= 1;
2848 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2849 ssh_state
= SSH_STATE_CLOSED
;
2850 logevent("Received disconnect request");
2852 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2853 /* Remote side is trying to open a channel to talk to our
2854 * X-Server. Give them back a local channel number. */
2855 struct ssh_channel
*c
;
2857 logevent("Received X11 connect request");
2858 /* Refuse if X11 forwarding is disabled. */
2859 if (!ssh_X11_fwd_enabled
) {
2860 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2861 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2862 logevent("Rejected X11 connect request");
2864 c
= smalloc(sizeof(struct ssh_channel
));
2866 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2867 logevent("opening X11 forward connection failed");
2869 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2870 PKT_INT
, GET_32BIT(pktin
.body
),
2874 ("opening X11 forward connection succeeded");
2875 c
->remoteid
= GET_32BIT(pktin
.body
);
2876 c
->localid
= alloc_channel_id();
2878 c
->v
.v1
.throttling
= 0;
2879 c
->type
= CHAN_X11
; /* identify channel type */
2880 add234(ssh_channels
, c
);
2881 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2882 PKT_INT
, c
->remoteid
, PKT_INT
,
2883 c
->localid
, PKT_END
);
2884 logevent("Opened X11 forward channel");
2887 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2888 /* Remote side is trying to open a channel to talk to our
2889 * agent. Give them back a local channel number. */
2890 struct ssh_channel
*c
;
2892 /* Refuse if agent forwarding is disabled. */
2893 if (!ssh_agentfwd_enabled
) {
2894 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2895 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2897 c
= smalloc(sizeof(struct ssh_channel
));
2898 c
->remoteid
= GET_32BIT(pktin
.body
);
2899 c
->localid
= alloc_channel_id();
2901 c
->v
.v1
.throttling
= 0;
2902 c
->type
= CHAN_AGENT
; /* identify channel type */
2903 c
->u
.a
.lensofar
= 0;
2904 add234(ssh_channels
, c
);
2905 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2906 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2909 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
2910 /* Remote side is trying to open a channel to talk to a
2911 * forwarded port. Give them back a local channel number. */
2912 struct ssh_channel
*c
;
2913 struct ssh_rportfwd pf
;
2915 char host
[256], buf
[1024];
2917 c
= smalloc(sizeof(struct ssh_channel
));
2919 hostsize
= GET_32BIT(pktin
.body
+4);
2920 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
2921 if (h
+1 < host
+sizeof(host
))
2926 port
= GET_32BIT(p
);
2928 strcpy(pf
.dhost
, host
);
2931 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
2932 sprintf(buf
, "Rejected remote port open request for %s:%d",
2935 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2936 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2938 sprintf(buf
, "Received remote port open request for %s:%d",
2941 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
2944 sprintf(buf
, "Port open failed: %s", e
);
2947 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2948 PKT_INT
, GET_32BIT(pktin
.body
),
2951 c
->remoteid
= GET_32BIT(pktin
.body
);
2952 c
->localid
= alloc_channel_id();
2954 c
->v
.v1
.throttling
= 0;
2955 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
2956 add234(ssh_channels
, c
);
2957 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2958 PKT_INT
, c
->remoteid
, PKT_INT
,
2959 c
->localid
, PKT_END
);
2960 logevent("Forwarded port opened successfully");
2964 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2965 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2966 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2967 struct ssh_channel
*c
;
2969 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2970 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2971 c
->remoteid
= localid
;
2972 c
->type
= CHAN_SOCKDATA
;
2973 c
->v
.v1
.throttling
= 0;
2974 pfd_confirm(c
->u
.pfd
.s
);
2977 if (c
&& c
->closes
) {
2979 * We have a pending close on this channel,
2980 * which we decided on before the server acked
2981 * the channel open. So now we know the
2982 * remoteid, we can close it again.
2984 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2988 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
2989 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2990 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2991 struct ssh_channel
*c
;
2993 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2994 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2995 logevent("Forwarded connection refused by server");
2996 pfd_close(c
->u
.pfd
.s
);
2997 del234(ssh_channels
, c
);
3001 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3002 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3003 /* Remote side closes a channel. */
3004 unsigned i
= GET_32BIT(pktin
.body
);
3005 struct ssh_channel
*c
;
3006 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3010 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3011 if (!(c
->closes
& closetype
))
3012 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
3014 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3015 logevent("Forwarded X11 connection terminated");
3016 assert(c
->u
.x11
.s
!= NULL
);
3017 x11_close(c
->u
.x11
.s
);
3020 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3021 logevent("Forwarded port closed");
3022 assert(c
->u
.pfd
.s
!= NULL
);
3023 pfd_close(c
->u
.pfd
.s
);
3026 c
->closes
|= closetype
;
3027 if (c
->closes
== 3) {
3028 del234(ssh_channels
, c
);
3032 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3033 /* Data sent down one of our channels. */
3034 int i
= GET_32BIT(pktin
.body
);
3035 int len
= GET_32BIT(pktin
.body
+ 4);
3036 unsigned char *p
= pktin
.body
+ 8;
3037 struct ssh_channel
*c
;
3038 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3043 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3046 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3049 /* Data for an agent message. Buffer it. */
3051 if (c
->u
.a
.lensofar
< 4) {
3052 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3053 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3057 c
->u
.a
.lensofar
+= l
;
3059 if (c
->u
.a
.lensofar
== 4) {
3061 4 + GET_32BIT(c
->u
.a
.msglen
);
3062 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3063 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3065 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3067 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3069 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3073 c
->u
.a
.lensofar
+= l
;
3075 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3076 void *reply
, *sentreply
;
3078 agent_query(c
->u
.a
.message
,
3079 c
->u
.a
.totallen
, &reply
,
3084 /* Fake SSH_AGENT_FAILURE. */
3085 sentreply
= "\0\0\0\1\5";
3088 send_packet(SSH1_MSG_CHANNEL_DATA
,
3089 PKT_INT
, c
->remoteid
,
3091 PKT_DATA
, sentreply
, replylen
,
3095 sfree(c
->u
.a
.message
);
3096 c
->u
.a
.lensofar
= 0;
3099 bufsize
= 0; /* agent channels never back up */
3102 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3103 c
->v
.v1
.throttling
= 1;
3107 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3108 /* may be from EXEC_SHELL on some servers */
3109 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3110 /* may be from EXEC_SHELL on some servers
3111 * if no pty is available or in other odd cases. Ignore */
3112 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3113 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3115 * In case `helpful' firewalls or proxies tack
3116 * extra human-readable text on the end of the
3117 * session which we might mistake for another
3118 * encrypted packet, we close the session once
3119 * we've sent EXIT_CONFIRMATION.
3121 ssh_state
= SSH_STATE_CLOSED
;
3124 bombout(("Strange packet received: type %d", pktin
.type
));
3129 int len
= min(inlen
, 512);
3130 send_packet(SSH1_CMSG_STDIN_DATA
,
3131 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3142 * Utility routine for decoding comma-separated strings in KEXINIT.
3144 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3146 int needlen
= strlen(needle
);
3149 * Is it at the start of the string?
3151 if (haylen
>= needlen
&& /* haystack is long enough */
3152 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3153 (haylen
== needlen
|| haystack
[needlen
] == ',')
3154 /* either , or EOS follows */
3158 * If not, search for the next comma and resume after that.
3159 * If no comma found, terminate.
3161 while (haylen
> 0 && *haystack
!= ',')
3162 haylen
--, haystack
++;
3165 haylen
--, haystack
++; /* skip over comma itself */
3170 * SSH2 key creation method.
3172 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3176 /* First 20 bytes. */
3179 SHA_Bytes(&s
, H
, 20);
3180 SHA_Bytes(&s
, &chr
, 1);
3181 SHA_Bytes(&s
, sessid
, 20);
3182 SHA_Final(&s
, keyspace
);
3183 /* Next 20 bytes. */
3186 SHA_Bytes(&s
, H
, 20);
3187 SHA_Bytes(&s
, keyspace
, 20);
3188 SHA_Final(&s
, keyspace
+ 20);
3192 * Handle the SSH2 transport layer.
3194 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3196 static int i
, j
, len
, nbits
, pbits
, warn
;
3198 static Bignum p
, g
, e
, f
, K
;
3199 static int kex_init_value
, kex_reply_value
;
3200 static const struct ssh_mac
**maclist
;
3202 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3203 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3204 static const struct ssh_mac
*csmac_tobe
= NULL
;
3205 static const struct ssh_mac
*scmac_tobe
= NULL
;
3206 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3207 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3208 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3209 static int hostkeylen
, siglen
;
3210 static void *hkey
; /* actual host key */
3211 static unsigned char exchange_hash
[20];
3212 static unsigned char keyspace
[40];
3213 static int n_preferred_ciphers
;
3214 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3215 static const struct ssh_compress
*preferred_comp
;
3216 static int cipherstr_started
;
3217 static int first_kex
;
3224 * Set up the preferred ciphers. (NULL => warn below here)
3226 n_preferred_ciphers
= 0;
3227 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3228 switch (cfg
.ssh_cipherlist
[i
]) {
3229 case CIPHER_BLOWFISH
:
3230 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3231 n_preferred_ciphers
++;
3234 if (cfg
.ssh2_des_cbc
) {
3235 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3236 n_preferred_ciphers
++;
3240 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3241 n_preferred_ciphers
++;
3244 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3245 n_preferred_ciphers
++;
3248 /* Flag for later. Don't bother if it's the last in
3250 if (i
< CIPHER_MAX
- 1) {
3251 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3252 n_preferred_ciphers
++;
3259 * Set up preferred compression.
3261 if (cfg
.compression
)
3262 preferred_comp
= &ssh_zlib
;
3264 preferred_comp
= &ssh_comp_none
;
3267 * Be prepared to work around the buggy MAC problem.
3269 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3270 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3272 maclist
= macs
, nmacs
= lenof(macs
);
3276 * Construct and send our key exchange packet.
3278 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3279 for (i
= 0; i
< 16; i
++)
3280 ssh2_pkt_addbyte((unsigned char) random_byte());
3281 /* List key exchange algorithms. */
3282 ssh2_pkt_addstring_start();
3283 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3284 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3285 if (i
< lenof(kex_algs
) - 1)
3286 ssh2_pkt_addstring_str(",");
3288 /* List server host key algorithms. */
3289 ssh2_pkt_addstring_start();
3290 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3291 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3292 if (i
< lenof(hostkey_algs
) - 1)
3293 ssh2_pkt_addstring_str(",");
3295 /* List client->server encryption algorithms. */
3296 ssh2_pkt_addstring_start();
3297 cipherstr_started
= 0;
3298 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3299 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3300 if (!c
) continue; /* warning flag */
3301 for (j
= 0; j
< c
->nciphers
; j
++) {
3302 if (cipherstr_started
)
3303 ssh2_pkt_addstring_str(",");
3304 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3305 cipherstr_started
= 1;
3308 /* List server->client encryption algorithms. */
3309 ssh2_pkt_addstring_start();
3310 cipherstr_started
= 0;
3311 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3312 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3313 if (!c
) continue; /* warning flag */
3314 for (j
= 0; j
< c
->nciphers
; j
++) {
3315 if (cipherstr_started
)
3316 ssh2_pkt_addstring_str(",");
3317 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3318 cipherstr_started
= 1;
3321 /* List client->server MAC algorithms. */
3322 ssh2_pkt_addstring_start();
3323 for (i
= 0; i
< nmacs
; i
++) {
3324 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3326 ssh2_pkt_addstring_str(",");
3328 /* List server->client MAC algorithms. */
3329 ssh2_pkt_addstring_start();
3330 for (i
= 0; i
< nmacs
; i
++) {
3331 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3333 ssh2_pkt_addstring_str(",");
3335 /* List client->server compression algorithms. */
3336 ssh2_pkt_addstring_start();
3337 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3338 const struct ssh_compress
*c
=
3339 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3340 ssh2_pkt_addstring_str(c
->name
);
3341 if (i
< lenof(compressions
))
3342 ssh2_pkt_addstring_str(",");
3344 /* List server->client compression algorithms. */
3345 ssh2_pkt_addstring_start();
3346 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3347 const struct ssh_compress
*c
=
3348 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3349 ssh2_pkt_addstring_str(c
->name
);
3350 if (i
< lenof(compressions
))
3351 ssh2_pkt_addstring_str(",");
3353 /* List client->server languages. Empty list. */
3354 ssh2_pkt_addstring_start();
3355 /* List server->client languages. Empty list. */
3356 ssh2_pkt_addstring_start();
3357 /* First KEX packet does _not_ follow, because we're not that brave. */
3358 ssh2_pkt_addbool(FALSE
);
3360 ssh2_pkt_adduint32(0);
3362 exhash
= exhashbase
;
3363 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3369 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3372 * Now examine the other side's KEXINIT to see what we're up
3375 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3376 bombout(("expected key exchange packet from server"));
3381 cscipher_tobe
= NULL
;
3382 sccipher_tobe
= NULL
;
3387 pktin
.savedpos
+= 16; /* skip garbage cookie */
3388 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3389 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3390 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3395 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3396 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3397 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3398 hostkey
= hostkey_algs
[i
];
3402 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3404 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3405 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3409 for (j
= 0; j
< c
->nciphers
; j
++) {
3410 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3411 cscipher_tobe
= c
->list
[j
];
3416 if (cscipher_tobe
) {
3418 askcipher(cscipher_tobe
->name
, 1);
3422 if (!cscipher_tobe
) {
3423 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3427 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3429 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3430 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3434 for (j
= 0; j
< c
->nciphers
; j
++) {
3435 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3436 sccipher_tobe
= c
->list
[j
];
3441 if (sccipher_tobe
) {
3443 askcipher(sccipher_tobe
->name
, 2);
3447 if (!sccipher_tobe
) {
3448 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3452 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3453 for (i
= 0; i
< nmacs
; i
++) {
3454 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3455 csmac_tobe
= maclist
[i
];
3459 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3460 for (i
= 0; i
< nmacs
; i
++) {
3461 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3462 scmac_tobe
= maclist
[i
];
3466 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3467 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3468 const struct ssh_compress
*c
=
3469 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3470 if (in_commasep_string(c
->name
, str
, len
)) {
3475 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3476 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3477 const struct ssh_compress
*c
=
3478 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3479 if (in_commasep_string(c
->name
, str
, len
)) {
3486 * Work out the number of bits of key we will need from the key
3487 * exchange. We start with the maximum key length of either
3493 csbits
= cscipher_tobe
->keylen
;
3494 scbits
= sccipher_tobe
->keylen
;
3495 nbits
= (csbits
> scbits ? csbits
: scbits
);
3497 /* The keys only have 160-bit entropy, since they're based on
3498 * a SHA-1 hash. So cap the key size at 160 bits. */
3503 * If we're doing Diffie-Hellman group exchange, start by
3504 * requesting a group.
3506 if (kex
== &ssh_diffiehellman_gex
) {
3507 logevent("Doing Diffie-Hellman group exchange");
3508 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3510 * Work out how big a DH group we will need to allow that
3513 pbits
= 512 << ((nbits
- 1) / 64);
3514 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3515 ssh2_pkt_adduint32(pbits
);
3519 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3520 bombout(("expected key exchange group packet from server"));
3523 p
= ssh2_pkt_getmp();
3524 g
= ssh2_pkt_getmp();
3525 dh_setup_group(p
, g
);
3526 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3527 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3529 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3531 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3532 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3535 logevent("Doing Diffie-Hellman key exchange");
3537 * Now generate and send e for Diffie-Hellman.
3539 e
= dh_create_e(nbits
* 2);
3540 ssh2_pkt_init(kex_init_value
);
3545 if (pktin
.type
!= kex_reply_value
) {
3546 bombout(("expected key exchange reply packet from server"));
3549 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3550 f
= ssh2_pkt_getmp();
3551 ssh2_pkt_getstring(&sigdata
, &siglen
);
3555 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3556 if (kex
== &ssh_diffiehellman_gex
) {
3557 sha_uint32(&exhash
, pbits
);
3558 sha_mpint(&exhash
, p
);
3559 sha_mpint(&exhash
, g
);
3561 sha_mpint(&exhash
, e
);
3562 sha_mpint(&exhash
, f
);
3563 sha_mpint(&exhash
, K
);
3564 SHA_Final(&exhash
, exchange_hash
);
3569 debug(("Exchange hash is:\n"));
3570 dmemdump(exchange_hash
, 20);
3573 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3575 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3576 bombout(("Server's host key did not match the signature supplied"));
3581 * Authenticate remote host: verify host key. (We've already
3582 * checked the signature of the exchange hash.)
3584 keystr
= hostkey
->fmtkey(hkey
);
3585 fingerprint
= hostkey
->fingerprint(hkey
);
3586 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3587 keystr
, fingerprint
);
3588 if (first_kex
) { /* don't bother logging this in rekeys */
3589 logevent("Host key fingerprint is:");
3590 logevent(fingerprint
);
3594 hostkey
->freekey(hkey
);
3597 * Send SSH2_MSG_NEWKEYS.
3599 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3603 * Expect SSH2_MSG_NEWKEYS from server.
3606 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3607 bombout(("expected new-keys packet from server"));
3612 * Create and initialise session keys.
3614 cscipher
= cscipher_tobe
;
3615 sccipher
= sccipher_tobe
;
3618 cscomp
= cscomp_tobe
;
3619 sccomp
= sccomp_tobe
;
3620 cscomp
->compress_init();
3621 sccomp
->decompress_init();
3623 * Set IVs after keys. Here we use the exchange hash from the
3624 * _first_ key exchange.
3627 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3628 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3629 cscipher
->setcskey(keyspace
);
3630 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3631 sccipher
->setsckey(keyspace
);
3632 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3633 cscipher
->setcsiv(keyspace
);
3634 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3635 sccipher
->setsciv(keyspace
);
3636 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3637 csmac
->setcskey(keyspace
);
3638 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3639 scmac
->setsckey(keyspace
);
3642 * If this is the first key exchange phase, we must pass the
3643 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3644 * wants to see it but because it will need time to initialise
3645 * itself before it sees an actual packet. In subsequent key
3646 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3647 * it would only confuse the layer above.
3655 * Now we're encrypting. Begin returning 1 to the protocol main
3656 * function so that other things can run on top of the
3657 * transport. If we ever see a KEXINIT, we must go back to the
3660 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3663 logevent("Server initiated key re-exchange");
3664 goto begin_key_exchange
;
3670 * Add data to an SSH2 channel output buffer.
3672 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3675 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3679 * Attempt to send data on an SSH2 channel.
3681 static int ssh2_try_send(struct ssh_channel
*c
)
3683 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3686 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3687 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3688 len
= c
->v
.v2
.remwindow
;
3689 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3690 len
= c
->v
.v2
.remmaxpkt
;
3691 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3692 ssh2_pkt_adduint32(c
->remoteid
);
3693 ssh2_pkt_addstring_start();
3694 ssh2_pkt_addstring_data(data
, len
);
3696 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3697 c
->v
.v2
.remwindow
-= len
;
3701 * After having sent as much data as we can, return the amount
3704 return bufchain_size(&c
->v
.v2
.outbuffer
);
3708 * Potentially enlarge the window on an SSH2 channel.
3710 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3712 if (newwin
> c
->v
.v2
.locwindow
) {
3713 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3714 ssh2_pkt_adduint32(c
->remoteid
);
3715 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3717 c
->v
.v2
.locwindow
= newwin
;
3722 * Handle the SSH2 userauth and connection layers.
3724 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3727 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3729 AUTH_KEYBOARD_INTERACTIVE
3733 AUTH_TYPE_PUBLICKEY
,
3734 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3735 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3737 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3738 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3740 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3741 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3742 static int kbd_inter_running
;
3743 static int we_are_in
;
3744 static int num_prompts
, echo
;
3745 static char username
[100];
3746 static char pwprompt
[200];
3747 static char password
[100];
3752 * Request userauth protocol, and await a response to it.
3754 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3755 ssh2_pkt_addstring("ssh-userauth");
3757 crWaitUntilV(ispkt
);
3758 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3759 bombout(("Server refused user authentication protocol"));
3764 * We repeat this whole loop, including the username prompt,
3765 * until we manage a successful authentication. If the user
3766 * types the wrong _password_, they are sent back to the
3767 * beginning to try another username. (If they specify a
3768 * username in the config, they are never asked, even if they
3769 * do give a wrong password.)
3771 * I think this best serves the needs of
3773 * - the people who have no configuration, no keys, and just
3774 * want to try repeated (username,password) pairs until they
3775 * type both correctly
3777 * - people who have keys and configuration but occasionally
3778 * need to fall back to passwords
3780 * - people with a key held in Pageant, who might not have
3781 * logged in to a particular machine before; so they want to
3782 * type a username, and then _either_ their key will be
3783 * accepted, _or_ they will type a password. If they mistype
3784 * the username they will want to be able to get back and
3796 if (*username
&& !cfg
.change_username
) {
3798 * We got a username last time round this loop, and
3799 * with change_username turned off we don't try to get
3802 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
3804 if (!ssh_get_line("login as: ",
3805 username
, sizeof(username
), FALSE
)) {
3807 * get_line failed to get a username.
3810 logevent("No username provided. Abandoning session.");
3811 ssh_state
= SSH_STATE_CLOSED
;
3815 c_write_str("login as: ");
3818 crWaitUntilV(!ispkt
);
3820 switch (c
= *in
++) {
3829 c_write_str("\b \b");
3836 c_write_str("\b \b");
3846 if (((c
>= ' ' && c
<= '~') ||
3847 ((unsigned char) c
>= 160))
3848 && pos
< sizeof(username
)-1) {
3849 username
[pos
++] = c
;
3856 c_write_str("\r\n");
3857 username
[strcspn(username
, "\n\r")] = '\0';
3860 strncpy(username
, cfg
.username
, 99);
3861 username
[99] = '\0';
3862 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3863 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3869 * Send an authentication request using method "none": (a)
3870 * just in case it succeeds, and (b) so that we know what
3871 * authentication methods we can usefully try next.
3873 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
3875 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3876 ssh2_pkt_addstring(username
);
3877 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3878 ssh2_pkt_addstring("none"); /* method */
3880 type
= AUTH_TYPE_NONE
;
3884 tried_pubkey_config
= FALSE
;
3885 tried_agent
= FALSE
;
3886 tried_keyb_inter
= FALSE
;
3887 kbd_inter_running
= FALSE
;
3891 * Wait for the result of the last authentication request.
3894 crWaitUntilV(ispkt
);
3895 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
3899 * Don't show the banner if we're operating in
3900 * non-verbose non-interactive mode. (It's probably
3901 * a script, which means nobody will read the
3902 * banner _anyway_, and moreover the printing of
3903 * the banner will screw up processing on the
3904 * output of (say) plink.)
3906 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
3907 ssh2_pkt_getstring(&banner
, &size
);
3909 c_write_untrusted(banner
, size
);
3911 crWaitUntilV(ispkt
);
3913 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
3914 logevent("Access granted");
3919 if (kbd_inter_running
&&
3920 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
3922 * This is a further prompt in keyboard-interactive
3923 * authentication. Do nothing.
3925 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
3926 bombout(("Strange packet received during authentication: type %d",
3934 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3935 * we can look at the string in it and know what we can
3936 * helpfully try next.
3938 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
3941 ssh2_pkt_getstring(&methods
, &methlen
);
3942 kbd_inter_running
= FALSE
;
3943 if (!ssh2_pkt_getbool()) {
3945 * We have received an unequivocal Access
3946 * Denied. This can translate to a variety of
3949 * - if we'd just tried "none" authentication,
3950 * it's not worth printing anything at all
3952 * - if we'd just tried a public key _offer_,
3953 * the message should be "Server refused our
3954 * key" (or no message at all if the key
3955 * came from Pageant)
3957 * - if we'd just tried anything else, the
3958 * message really should be "Access denied".
3960 * Additionally, if we'd just tried password
3961 * authentication, we should break out of this
3962 * whole loop so as to go back to the username
3965 if (type
== AUTH_TYPE_NONE
) {
3967 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
3968 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
3969 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
3970 c_write_str("Server refused our key\r\n");
3971 logevent("Server refused public key");
3972 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
3973 /* server declined keyboard-interactive; ignore */
3975 c_write_str("Access denied\r\n");
3976 logevent("Access denied");
3977 if (type
== AUTH_TYPE_PASSWORD
) {
3983 c_write_str("Further authentication required\r\n");
3984 logevent("Further authentication required");
3988 in_commasep_string("publickey", methods
, methlen
);
3990 in_commasep_string("password", methods
, methlen
);
3991 can_keyb_inter
= cfg
.try_ki_auth
&&
3992 in_commasep_string("keyboard-interactive", methods
, methlen
);
3996 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
3998 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
4000 * Attempt public-key authentication using Pageant.
4002 static unsigned char request
[5], *response
, *p
;
4003 static int responselen
;
4004 static int i
, nkeys
;
4005 static int authed
= FALSE
;
4008 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4012 logevent("Pageant is running. Requesting keys.");
4014 /* Request the keys held by the agent. */
4015 PUT_32BIT(request
, 1);
4016 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4017 agent_query(request
, 5, &r
, &responselen
);
4018 response
= (unsigned char *) r
;
4019 if (response
&& responselen
>= 5 &&
4020 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4022 nkeys
= GET_32BIT(p
);
4026 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
4029 for (i
= 0; i
< nkeys
; i
++) {
4030 static char *pkblob
, *alg
, *commentp
;
4031 static int pklen
, alglen
, commentlen
;
4032 static int siglen
, retlen
, len
;
4033 static char *q
, *agentreq
, *ret
;
4038 sprintf(buf
, "Trying Pageant key #%d", i
);
4041 pklen
= GET_32BIT(p
);
4045 alglen
= GET_32BIT(pkblob
);
4047 commentlen
= GET_32BIT(p
);
4051 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4052 ssh2_pkt_addstring(username
);
4053 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4054 ssh2_pkt_addstring("publickey"); /* method */
4055 ssh2_pkt_addbool(FALSE
); /* no signature included */
4056 ssh2_pkt_addstring_start();
4057 ssh2_pkt_addstring_data(alg
, alglen
);
4058 ssh2_pkt_addstring_start();
4059 ssh2_pkt_addstring_data(pkblob
, pklen
);
4062 crWaitUntilV(ispkt
);
4063 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4064 logevent("Key refused");
4068 if (flags
& FLAG_VERBOSE
) {
4070 ("Authenticating with public key \"");
4071 c_write(commentp
, commentlen
);
4072 c_write_str("\" from agent\r\n");
4076 * Server is willing to accept the key.
4077 * Construct a SIGN_REQUEST.
4079 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4080 ssh2_pkt_addstring(username
);
4081 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4082 ssh2_pkt_addstring("publickey"); /* method */
4083 ssh2_pkt_addbool(TRUE
);
4084 ssh2_pkt_addstring_start();
4085 ssh2_pkt_addstring_data(alg
, alglen
);
4086 ssh2_pkt_addstring_start();
4087 ssh2_pkt_addstring_data(pkblob
, pklen
);
4089 siglen
= pktout
.length
- 5 + 4 + 20;
4090 len
= 1; /* message type */
4091 len
+= 4 + pklen
; /* key blob */
4092 len
+= 4 + siglen
; /* data to sign */
4093 len
+= 4; /* flags */
4094 agentreq
= smalloc(4 + len
);
4095 PUT_32BIT(agentreq
, len
);
4097 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4098 PUT_32BIT(q
, pklen
);
4100 memcpy(q
, pkblob
, pklen
);
4102 PUT_32BIT(q
, siglen
);
4104 /* Now the data to be signed... */
4107 memcpy(q
, ssh2_session_id
, 20);
4109 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4110 q
+= pktout
.length
- 5;
4111 /* And finally the (zero) flags word. */
4113 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4117 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4118 logevent("Sending Pageant's response");
4119 ssh2_pkt_addstring_start();
4120 ssh2_pkt_addstring_data(ret
+ 9,
4128 ("Pageant failed to answer challenge");
4138 if (!method
&& can_pubkey
&& *cfg
.keyfile
4139 && !tried_pubkey_config
) {
4140 unsigned char *pub_blob
;
4141 char *algorithm
, *comment
;
4144 tried_pubkey_config
= TRUE
;
4146 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4149 * Try the public key supplied in the configuration.
4151 * First, offer the public blob to see if the server is
4152 * willing to accept it.
4154 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4157 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4158 ssh2_pkt_addstring(username
);
4159 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4160 ssh2_pkt_addstring("publickey"); /* method */
4161 ssh2_pkt_addbool(FALSE
); /* no signature included */
4162 ssh2_pkt_addstring(algorithm
);
4163 ssh2_pkt_addstring_start();
4164 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4166 logevent("Offered public key"); /* FIXME */
4168 crWaitUntilV(ispkt
);
4169 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4171 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4172 continue; /* key refused; give up on it */
4175 logevent("Offer of public key accepted");
4177 * Actually attempt a serious authentication using
4180 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4182 "Passphrase for key \"%.100s\": ",
4188 c_write_str("Authenticating with public key \"");
4189 c_write_str(comment
);
4190 c_write_str("\"\r\n");
4191 method
= AUTH_PUBLICKEY_FILE
;
4195 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4196 method
= AUTH_KEYBOARD_INTERACTIVE
;
4197 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4198 tried_keyb_inter
= TRUE
;
4200 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4202 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4203 ssh2_pkt_addstring(username
);
4204 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4205 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4206 ssh2_pkt_addstring(""); /* lang */
4207 ssh2_pkt_addstring("");
4210 crWaitUntilV(ispkt
);
4211 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4212 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4214 logevent("Keyboard-interactive authentication refused");
4215 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4219 kbd_inter_running
= TRUE
;
4222 if (kbd_inter_running
) {
4223 method
= AUTH_KEYBOARD_INTERACTIVE
;
4224 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4225 tried_keyb_inter
= TRUE
;
4227 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4229 /* We've got packet with that "interactive" info
4230 dump banners, and set its prompt as ours */
4232 char *name
, *inst
, *lang
, *prompt
;
4233 int name_len
, inst_len
, lang_len
, prompt_len
;
4234 ssh2_pkt_getstring(&name
, &name_len
);
4235 ssh2_pkt_getstring(&inst
, &inst_len
);
4236 ssh2_pkt_getstring(&lang
, &lang_len
);
4238 c_write_untrusted(name
, name_len
);
4240 c_write_untrusted(inst
, inst_len
);
4241 num_prompts
= ssh2_pkt_getuint32();
4243 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4244 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4245 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4246 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4249 echo
= ssh2_pkt_getbool();
4253 if (!method
&& can_passwd
) {
4254 method
= AUTH_PASSWORD
;
4255 ssh_pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4256 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4263 if (!ssh_get_line(pwprompt
, password
,
4264 sizeof(password
), TRUE
)) {
4266 * get_line failed to get a password (for
4267 * example because one was supplied on the
4268 * command line which has already failed to
4271 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4272 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4274 ("No more passwords available to try");
4275 ssh2_pkt_addstring("en"); /* language tag */
4277 connection_fatal("Unable to authenticate");
4278 ssh_state
= SSH_STATE_CLOSED
;
4285 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4290 crWaitUntilV(!ispkt
);
4292 switch (c
= *in
++) {
4313 if (pos
< sizeof(password
)-1)
4314 password
[pos
++] = c
;
4318 c_write_str("\r\n");
4322 if (method
== AUTH_PUBLICKEY_FILE
) {
4324 * We have our passphrase. Now try the actual authentication.
4326 struct ssh2_userkey
*key
;
4328 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4329 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4330 if (key
== SSH2_WRONG_PASSPHRASE
) {
4331 c_write_str("Wrong passphrase\r\n");
4332 tried_pubkey_config
= FALSE
;
4334 c_write_str("Unable to load private key\r\n");
4335 tried_pubkey_config
= TRUE
;
4337 /* Send a spurious AUTH_NONE to return to the top. */
4338 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4339 ssh2_pkt_addstring(username
);
4340 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4341 ssh2_pkt_addstring("none"); /* method */
4343 type
= AUTH_TYPE_NONE
;
4345 unsigned char *blob
, *sigdata
;
4346 int blob_len
, sigdata_len
;
4349 * We have loaded the private key and the server
4350 * has announced that it's willing to accept it.
4351 * Hallelujah. Generate a signature and send it.
4353 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4354 ssh2_pkt_addstring(username
);
4355 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4356 ssh2_pkt_addstring("publickey"); /* method */
4357 ssh2_pkt_addbool(TRUE
);
4358 ssh2_pkt_addstring(key
->alg
->name
);
4359 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4360 ssh2_pkt_addstring_start();
4361 ssh2_pkt_addstring_data(blob
, blob_len
);
4365 * The data to be signed is:
4369 * followed by everything so far placed in the
4372 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4373 sigdata
= smalloc(sigdata_len
);
4374 PUT_32BIT(sigdata
, 20);
4375 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4376 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4379 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4381 ssh2_pkt_addstring_start();
4382 ssh2_pkt_addstring_data(blob
, blob_len
);
4387 type
= AUTH_TYPE_PUBLICKEY
;
4389 } else if (method
== AUTH_PASSWORD
) {
4391 * We send the password packet lumped tightly together with
4392 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4393 * string long enough to make the total length of the two
4394 * packets constant. This should ensure that a passive
4395 * listener doing traffic analyis can't work out the length
4398 * For this to work, we need an assumption about the
4399 * maximum length of the password packet. I think 256 is
4400 * pretty conservative. Anyone using a password longer than
4401 * that probably doesn't have much to worry about from
4402 * people who find out how long their password is!
4404 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4405 ssh2_pkt_addstring(username
);
4406 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4407 ssh2_pkt_addstring("password");
4408 ssh2_pkt_addbool(FALSE
);
4409 ssh2_pkt_addstring(password
);
4412 * We'll include a string that's an exact multiple of the
4413 * cipher block size. If the cipher is NULL for some
4414 * reason, we don't do this trick at all because we gain
4420 stringlen
= (256 - deferred_len
);
4421 stringlen
+= cscipher
->blksize
- 1;
4422 stringlen
-= (stringlen
% cscipher
->blksize
);
4425 * Temporarily disable actual compression,
4426 * so we can guarantee to get this string
4427 * exactly the length we want it. The
4428 * compression-disabling routine should
4429 * return an integer indicating how many
4430 * bytes we should adjust our string length
4433 stringlen
-= cscomp
->disable_compression();
4435 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4436 ssh2_pkt_addstring_start();
4437 for (i
= 0; i
< stringlen
; i
++) {
4438 char c
= (char) random_byte();
4439 ssh2_pkt_addstring_data(&c
, 1);
4443 ssh_pkt_defersend();
4444 logevent("Sent password");
4445 type
= AUTH_TYPE_PASSWORD
;
4446 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4447 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4448 ssh2_pkt_adduint32(num_prompts
);
4449 ssh2_pkt_addstring(password
);
4450 memset(password
, 0, sizeof(password
));
4452 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4455 ("No supported authentication methods left to try!\r\n");
4457 ("No supported authentications offered. Disconnecting");
4458 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4459 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4461 ("No supported authentication methods available");
4462 ssh2_pkt_addstring("en"); /* language tag */
4464 ssh_state
= SSH_STATE_CLOSED
;
4468 } while (!we_are_in
);
4471 * Now we're authenticated for the connection protocol. The
4472 * connection protocol will automatically have started at this
4473 * point; there's no need to send SERVICE_REQUEST.
4477 * So now create a channel with a session in it.
4479 ssh_channels
= newtree234(ssh_channelcmp
);
4480 mainchan
= smalloc(sizeof(struct ssh_channel
));
4481 mainchan
->localid
= alloc_channel_id();
4482 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4483 ssh2_pkt_addstring("session");
4484 ssh2_pkt_adduint32(mainchan
->localid
);
4485 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4486 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4487 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4489 crWaitUntilV(ispkt
);
4490 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4491 bombout(("Server refused to open a session"));
4493 /* FIXME: error data comes back in FAILURE packet */
4495 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4496 bombout(("Server's channel confirmation cited wrong channel"));
4499 mainchan
->remoteid
= ssh2_pkt_getuint32();
4500 mainchan
->type
= CHAN_MAINSESSION
;
4501 mainchan
->closes
= 0;
4502 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4503 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4504 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4505 add234(ssh_channels
, mainchan
);
4506 logevent("Opened channel for session");
4509 * Potentially enable X11 forwarding.
4511 if (cfg
.x11_forward
) {
4512 char proto
[20], data
[64];
4513 logevent("Requesting X11 forwarding");
4514 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4515 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4516 ssh2_pkt_adduint32(mainchan
->remoteid
);
4517 ssh2_pkt_addstring("x11-req");
4518 ssh2_pkt_addbool(1); /* want reply */
4519 ssh2_pkt_addbool(0); /* many connections */
4520 ssh2_pkt_addstring(proto
);
4521 ssh2_pkt_addstring(data
);
4522 ssh2_pkt_adduint32(0); /* screen number */
4526 crWaitUntilV(ispkt
);
4527 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4528 unsigned i
= ssh2_pkt_getuint32();
4529 struct ssh_channel
*c
;
4530 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4532 continue; /* nonexistent channel */
4533 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4535 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4537 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4538 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4539 bombout(("Unexpected response to X11 forwarding request:"
4540 " packet type %d", pktin
.type
));
4543 logevent("X11 forwarding refused");
4545 logevent("X11 forwarding enabled");
4546 ssh_X11_fwd_enabled
= TRUE
;
4551 * Enable port forwardings.
4554 static char *e
; /* preserve across crReturn */
4558 char sports
[256], dports
[256], host
[256];
4561 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4562 /* Add port forwardings. */
4567 while (*e
&& *e
!= '\t')
4573 while (*e
&& *e
!= ':')
4583 dport
= atoi(dports
);
4584 sport
= atoi(sports
);
4585 if (sport
&& dport
) {
4587 pfd_addforward(host
, dport
, sport
);
4588 sprintf(buf
, "Local port %d forwarding to %s:%d",
4589 sport
, host
, dport
);
4592 struct ssh_rportfwd
*pf
;
4593 pf
= smalloc(sizeof(*pf
));
4594 strcpy(pf
->dhost
, host
);
4597 if (add234(ssh_rportfwds
, pf
) != pf
) {
4599 "Duplicate remote port forwarding to %s:%d",
4604 sprintf(buf
, "Requesting remote port %d (forwarded to %s:%d)",
4605 sport
, host
, dport
);
4607 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4608 ssh2_pkt_addstring("tcpip-forward");
4609 ssh2_pkt_addbool(1);/* want reply */
4610 if (cfg
.rport_acceptall
)
4611 ssh2_pkt_addstring("0.0.0.0");
4613 ssh2_pkt_addstring("127.0.0.1");
4614 ssh2_pkt_adduint32(sport
);
4618 crWaitUntilV(ispkt
);
4619 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4620 unsigned i
= ssh2_pkt_getuint32();
4621 struct ssh_channel
*c
;
4622 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4624 continue;/* nonexistent channel */
4625 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4627 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4629 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4630 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4631 bombout(("Unexpected response to port "
4632 "forwarding request: packet type %d",
4636 logevent("Server refused this port forwarding");
4638 logevent("Remote port forwarding enabled");
4647 * Potentially enable agent forwarding.
4649 if (cfg
.agentfwd
&& agent_exists()) {
4650 logevent("Requesting OpenSSH-style agent forwarding");
4651 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4652 ssh2_pkt_adduint32(mainchan
->remoteid
);
4653 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4654 ssh2_pkt_addbool(1); /* want reply */
4658 crWaitUntilV(ispkt
);
4659 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4660 unsigned i
= ssh2_pkt_getuint32();
4661 struct ssh_channel
*c
;
4662 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4664 continue; /* nonexistent channel */
4665 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4667 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4669 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4670 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4671 bombout(("Unexpected response to agent forwarding request:"
4672 " packet type %d", pktin
.type
));
4675 logevent("Agent forwarding refused");
4677 logevent("Agent forwarding enabled");
4678 ssh_agentfwd_enabled
= TRUE
;
4683 * Now allocate a pty for the session.
4686 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4687 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4688 ssh2_pkt_addstring("pty-req");
4689 ssh2_pkt_addbool(1); /* want reply */
4690 ssh2_pkt_addstring(cfg
.termtype
);
4691 ssh2_pkt_adduint32(cols
);
4692 ssh2_pkt_adduint32(rows
);
4693 ssh2_pkt_adduint32(0); /* pixel width */
4694 ssh2_pkt_adduint32(0); /* pixel height */
4695 ssh2_pkt_addstring_start();
4696 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4698 ssh_state
= SSH_STATE_INTERMED
;
4701 crWaitUntilV(ispkt
);
4702 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4703 unsigned i
= ssh2_pkt_getuint32();
4704 struct ssh_channel
*c
;
4705 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4707 continue; /* nonexistent channel */
4708 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4710 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4712 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4713 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4714 bombout(("Unexpected response to pty request:"
4715 " packet type %d", pktin
.type
));
4718 c_write_str("Server refused to allocate pty\r\n");
4719 ssh_editing
= ssh_echoing
= 1;
4721 logevent("Allocated pty");
4724 ssh_editing
= ssh_echoing
= 1;
4728 * Start a shell or a remote command. We may have to attempt
4729 * this twice if the config data has provided a second choice
4736 if (ssh_fallback_cmd
) {
4737 subsys
= cfg
.ssh_subsys2
;
4738 cmd
= cfg
.remote_cmd_ptr2
;
4740 subsys
= cfg
.ssh_subsys
;
4741 cmd
= cfg
.remote_cmd_ptr
;
4744 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4745 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4747 ssh2_pkt_addstring("subsystem");
4748 ssh2_pkt_addbool(1); /* want reply */
4749 ssh2_pkt_addstring(cmd
);
4751 ssh2_pkt_addstring("exec");
4752 ssh2_pkt_addbool(1); /* want reply */
4753 ssh2_pkt_addstring(cmd
);
4755 ssh2_pkt_addstring("shell");
4756 ssh2_pkt_addbool(1); /* want reply */
4760 crWaitUntilV(ispkt
);
4761 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4762 unsigned i
= ssh2_pkt_getuint32();
4763 struct ssh_channel
*c
;
4764 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4766 continue; /* nonexistent channel */
4767 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4769 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4770 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4771 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4772 bombout(("Unexpected response to shell/command request:"
4773 " packet type %d", pktin
.type
));
4777 * We failed to start the command. If this is the
4778 * fallback command, we really are finished; if it's
4779 * not, and if the fallback command exists, try falling
4780 * back to it before complaining.
4782 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
4783 logevent("Primary command failed; attempting fallback");
4784 ssh_fallback_cmd
= TRUE
;
4787 bombout(("Server refused to start a shell/command"));
4790 logevent("Started a shell/command");
4795 ssh_state
= SSH_STATE_SESSION
;
4799 ssh_special(TS_EOF
);
4804 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
4807 static int try_send
;
4811 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
4812 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
4815 unsigned i
= ssh2_pkt_getuint32();
4816 struct ssh_channel
*c
;
4817 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4819 continue; /* nonexistent channel */
4820 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
4821 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
4822 continue; /* extended but not stderr */
4823 ssh2_pkt_getstring(&data
, &length
);
4826 c
->v
.v2
.locwindow
-= length
;
4828 case CHAN_MAINSESSION
:
4830 from_backend(pktin
.type
==
4831 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
4835 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
4838 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
4841 while (length
> 0) {
4842 if (c
->u
.a
.lensofar
< 4) {
4843 int l
= min(4 - c
->u
.a
.lensofar
, length
);
4844 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
4848 c
->u
.a
.lensofar
+= l
;
4850 if (c
->u
.a
.lensofar
== 4) {
4852 4 + GET_32BIT(c
->u
.a
.msglen
);
4853 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
4854 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
4856 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
4858 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
4860 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
4864 c
->u
.a
.lensofar
+= l
;
4866 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
4867 void *reply
, *sentreply
;
4869 agent_query(c
->u
.a
.message
,
4870 c
->u
.a
.totallen
, &reply
,
4875 /* Fake SSH_AGENT_FAILURE. */
4876 sentreply
= "\0\0\0\1\5";
4879 ssh2_add_channel_data(c
, sentreply
,
4884 sfree(c
->u
.a
.message
);
4885 c
->u
.a
.lensofar
= 0;
4892 * If we are not buffering too much data,
4893 * enlarge the window again at the remote side.
4895 if (bufsize
< OUR_V2_WINSIZE
)
4896 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
4898 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
4899 ssh_state
= SSH_STATE_CLOSED
;
4900 logevent("Received disconnect message");
4902 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
4903 unsigned i
= ssh2_pkt_getuint32();
4904 struct ssh_channel
*c
;
4906 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4908 continue; /* nonexistent channel */
4910 if (c
->type
== CHAN_X11
) {
4912 * Remote EOF on an X11 channel means we should
4913 * wrap up and close the channel ourselves.
4915 x11_close(c
->u
.x11
.s
);
4917 } else if (c
->type
== CHAN_AGENT
) {
4919 } else if (c
->type
== CHAN_SOCKDATA
) {
4920 pfd_close(c
->u
.pfd
.s
);
4923 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
4924 unsigned i
= ssh2_pkt_getuint32();
4925 struct ssh_channel
*c
;
4927 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4929 continue; /* nonexistent channel */
4930 /* Do pre-close processing on the channel. */
4932 case CHAN_MAINSESSION
:
4933 break; /* nothing to see here, move along */
4935 if (c
->u
.x11
.s
!= NULL
)
4936 x11_close(c
->u
.x11
.s
);
4943 if (c
->u
.pfd
.s
!= NULL
)
4944 pfd_close(c
->u
.pfd
.s
);
4948 if (c
->closes
== 0) {
4949 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4950 ssh2_pkt_adduint32(c
->remoteid
);
4953 del234(ssh_channels
, c
);
4954 bufchain_clear(&c
->v
.v2
.outbuffer
);
4958 * See if that was the last channel left open.
4960 if (count234(ssh_channels
) == 0) {
4963 * We used to send SSH_MSG_DISCONNECT here,
4964 * because I'd believed that _every_ conforming
4965 * SSH2 connection had to end with a disconnect
4966 * being sent by at least one side; apparently
4967 * I was wrong and it's perfectly OK to
4968 * unceremoniously slam the connection shut
4969 * when you're done, and indeed OpenSSH feels
4970 * this is more polite than sending a
4971 * DISCONNECT. So now we don't.
4973 logevent("All channels closed. Disconnecting");
4974 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4975 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4976 ssh2_pkt_addstring("All open channels closed");
4977 ssh2_pkt_addstring("en"); /* language tag */
4980 ssh_state
= SSH_STATE_CLOSED
;
4983 continue; /* remote sends close; ignore (FIXME) */
4984 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4985 unsigned i
= ssh2_pkt_getuint32();
4986 struct ssh_channel
*c
;
4987 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4989 continue; /* nonexistent channel */
4990 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4992 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4993 unsigned i
= ssh2_pkt_getuint32();
4994 struct ssh_channel
*c
;
4995 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4997 continue; /* nonexistent channel */
4998 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4999 continue; /* dunno why they're confirming this */
5000 c
->remoteid
= ssh2_pkt_getuint32();
5001 c
->type
= CHAN_SOCKDATA
;
5002 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
5003 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
5004 bufchain_init(&c
->v
.v2
.outbuffer
);
5006 pfd_confirm(c
->u
.pfd
.s
);
5009 * We have a pending close on this channel,
5010 * which we decided on before the server acked
5011 * the channel open. So now we know the
5012 * remoteid, we can close it again.
5014 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5015 ssh2_pkt_adduint32(c
->remoteid
);
5018 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5019 unsigned i
= ssh2_pkt_getuint32();
5020 struct ssh_channel
*c
;
5021 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5023 continue; /* nonexistent channel */
5024 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5025 continue; /* dunno why they're failing this */
5027 logevent("Forwarded connection refused by server");
5029 pfd_close(c
->u
.pfd
.s
);
5031 del234(ssh_channels
, c
);
5033 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5036 int typelen
, want_reply
;
5037 struct ssh_channel
*c
;
5039 localid
= ssh2_pkt_getuint32();
5040 ssh2_pkt_getstring(&type
, &typelen
);
5041 want_reply
= ssh2_pkt_getbool();
5044 * First, check that the channel exists. Otherwise,
5045 * we can instantly disconnect with a rude message.
5047 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
5050 sprintf(buf
, "Received channel request for nonexistent"
5051 " channel %d", localid
);
5053 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5054 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5055 ssh2_pkt_addstring(buf
);
5056 ssh2_pkt_addstring("en"); /* language tag */
5058 connection_fatal(buf
);
5059 ssh_state
= SSH_STATE_CLOSED
;
5064 * We don't recognise any form of channel request,
5065 * so we now either ignore the request or respond
5066 * with CHANNEL_FAILURE, depending on want_reply.
5069 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
5070 ssh2_pkt_adduint32(c
->remoteid
);
5073 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5077 struct ssh_channel
*c
;
5078 unsigned remid
, winsize
, pktsize
;
5079 ssh2_pkt_getstring(&type
, &typelen
);
5080 c
= smalloc(sizeof(struct ssh_channel
));
5082 remid
= ssh2_pkt_getuint32();
5083 winsize
= ssh2_pkt_getuint32();
5084 pktsize
= ssh2_pkt_getuint32();
5086 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5087 if (!ssh_X11_fwd_enabled
)
5088 error
= "X11 forwarding is not enabled";
5089 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
5091 error
= "Unable to open an X11 connection";
5095 } else if (typelen
== 15 &&
5096 !memcmp(type
, "forwarded-tcpip", 15)) {
5097 struct ssh_rportfwd pf
, *realpf
;
5100 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
5101 pf
.sport
= ssh2_pkt_getuint32();
5102 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
5103 if (realpf
== NULL
) {
5104 error
= "Remote port is not recognised";
5106 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5109 sprintf(buf
, "Received remote port open request for %s:%d",
5110 realpf
->dhost
, realpf
->dport
);
5113 sprintf(buf
, "Port open failed: %s", e
);
5115 error
= "Port open failed";
5117 logevent("Forwarded port opened successfully");
5118 c
->type
= CHAN_SOCKDATA
;
5121 } else if (typelen
== 22 &&
5122 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5123 if (!ssh_agentfwd_enabled
)
5124 error
= "Agent forwarding is not enabled";
5126 c
->type
= CHAN_AGENT
; /* identify channel type */
5127 c
->u
.a
.lensofar
= 0;
5130 error
= "Unsupported channel type requested";
5133 c
->remoteid
= remid
;
5135 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5136 ssh2_pkt_adduint32(c
->remoteid
);
5137 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5138 ssh2_pkt_addstring(error
);
5139 ssh2_pkt_addstring("en"); /* language tag */
5143 c
->localid
= alloc_channel_id();
5145 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5146 c
->v
.v2
.remwindow
= winsize
;
5147 c
->v
.v2
.remmaxpkt
= pktsize
;
5148 bufchain_init(&c
->v
.v2
.outbuffer
);
5149 add234(ssh_channels
, c
);
5150 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5151 ssh2_pkt_adduint32(c
->remoteid
);
5152 ssh2_pkt_adduint32(c
->localid
);
5153 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5154 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5158 bombout(("Strange packet received: type %d", pktin
.type
));
5163 * We have spare data. Add it to the channel buffer.
5165 ssh2_add_channel_data(mainchan
, in
, inlen
);
5170 struct ssh_channel
*c
;
5172 * Try to send data on all channels if we can.
5174 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5175 int bufsize
= ssh2_try_send(c
);
5178 case CHAN_MAINSESSION
:
5179 /* stdin need not receive an unthrottle
5180 * notification since it will be polled */
5183 x11_unthrottle(c
->u
.x11
.s
);
5186 /* agent sockets are request/response and need no
5187 * buffer management */
5190 pfd_unthrottle(c
->u
.pfd
.s
);
5202 * Handle the top-level SSH2 protocol.
5204 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5206 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5208 do_ssh2_authconn(in
, inlen
, ispkt
);
5212 * Called to set up the connection.
5214 * Returns an error message, or NULL on success.
5216 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5221 if (crypto_startup() == 0)
5222 return "Microsoft high encryption pack not installed!";
5228 ssh1_throttle_count
= 0;
5229 ssh_overall_bufsize
= 0;
5230 ssh_fallback_cmd
= 0;
5232 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5240 * Called to send data down the Telnet connection.
5242 static int ssh_send(char *buf
, int len
)
5244 if (s
== NULL
|| ssh_protocol
== NULL
)
5247 ssh_protocol(buf
, len
, 0);
5249 return ssh_sendbuffer();
5253 * Called to query the current amount of buffered stdin data.
5255 static int ssh_sendbuffer(void)
5259 if (s
== NULL
|| ssh_protocol
== NULL
)
5263 * If the SSH socket itself has backed up, add the total backup
5264 * size on that to any individual buffer on the stdin channel.
5267 if (ssh_throttled_all
)
5268 override_value
= ssh_overall_bufsize
;
5270 if (ssh_version
== 1) {
5271 return override_value
;
5272 } else if (ssh_version
== 2) {
5273 if (!mainchan
|| mainchan
->closes
> 0)
5274 return override_value
;
5276 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5283 * Called to set the size of the window from SSH's POV.
5285 static void ssh_size(void)
5287 switch (ssh_state
) {
5288 case SSH_STATE_BEFORE_SIZE
:
5289 case SSH_STATE_PREPACKET
:
5290 case SSH_STATE_CLOSED
:
5291 break; /* do nothing */
5292 case SSH_STATE_INTERMED
:
5293 size_needed
= TRUE
; /* buffer for later */
5295 case SSH_STATE_SESSION
:
5297 if (ssh_version
== 1) {
5298 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5299 PKT_INT
, rows
, PKT_INT
, cols
,
5300 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5302 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5303 ssh2_pkt_adduint32(mainchan
->remoteid
);
5304 ssh2_pkt_addstring("window-change");
5305 ssh2_pkt_addbool(0);
5306 ssh2_pkt_adduint32(cols
);
5307 ssh2_pkt_adduint32(rows
);
5308 ssh2_pkt_adduint32(0);
5309 ssh2_pkt_adduint32(0);
5318 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5319 * can send an EOF and collect resulting output (e.g. `plink
5322 static void ssh_special(Telnet_Special code
)
5324 if (code
== TS_EOF
) {
5325 if (ssh_state
!= SSH_STATE_SESSION
) {
5327 * Buffer the EOF in case we are pre-SESSION, so we can
5328 * send it as soon as we reach SESSION.
5334 if (ssh_version
== 1) {
5335 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5337 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5338 ssh2_pkt_adduint32(mainchan
->remoteid
);
5341 logevent("Sent EOF message");
5342 } else if (code
== TS_PING
) {
5343 if (ssh_state
== SSH_STATE_CLOSED
5344 || ssh_state
== SSH_STATE_PREPACKET
) return;
5345 if (ssh_version
== 1) {
5346 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5348 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5349 ssh2_pkt_addstring_start();
5357 void *new_sock_channel(Socket s
)
5359 struct ssh_channel
*c
;
5360 c
= smalloc(sizeof(struct ssh_channel
));
5363 c
->remoteid
= -1; /* to be set when open confirmed */
5364 c
->localid
= alloc_channel_id();
5366 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5368 add234(ssh_channels
, c
);
5374 * This is called when stdout/stderr (the entity to which
5375 * from_backend sends data) manages to clear some backlog.
5377 void ssh_unthrottle(int bufsize
)
5379 if (ssh_version
== 1) {
5380 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5381 ssh1_stdout_throttling
= 0;
5385 if (mainchan
&& mainchan
->closes
== 0)
5386 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5390 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5392 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5395 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5398 if (ssh_version
== 1) {
5399 send_packet(SSH1_MSG_PORT_OPEN
,
5400 PKT_INT
, c
->localid
,
5403 //PKT_STR, <org:orgport>,
5406 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5407 ssh2_pkt_addstring("direct-tcpip");
5408 ssh2_pkt_adduint32(c
->localid
);
5409 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5410 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5411 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5412 ssh2_pkt_addstring(hostname
);
5413 ssh2_pkt_adduint32(port
);
5415 * We make up values for the originator data; partly it's
5416 * too much hassle to keep track, and partly I'm not
5417 * convinced the server should be told details like that
5418 * about my local network configuration.
5420 ssh2_pkt_addstring("client-side-connection");
5421 ssh2_pkt_adduint32(0);
5427 static Socket
ssh_socket(void)
5432 static int ssh_sendok(void)
5437 static int ssh_ldisc(int option
)
5439 if (option
== LD_ECHO
)
5441 if (option
== LD_EDIT
)
5446 Backend ssh_backend
= {