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 */
502 static int ssh_exitcode
= -1;
504 static tree234
*ssh_rportfwds
;
508 SSH_STATE_BEFORE_SIZE
,
512 } ssh_state
= SSH_STATE_PREPACKET
;
514 static int size_needed
= FALSE
, eof_needed
= FALSE
;
516 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
517 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
518 static unsigned char *deferred_send_data
= NULL
;
519 static int deferred_len
= 0, deferred_size
= 0;
522 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
523 * that fails. This variable is the means by which scp.c can reach
524 * into the SSH code and find out which one it got.
526 int ssh_fallback_cmd
= 0;
528 static int ssh_version
;
529 static int ssh1_throttle_count
;
530 static int ssh_overall_bufsize
;
531 static int ssh_throttled_all
;
532 static int ssh1_stdout_throttling
;
533 static void (*ssh_protocol
) (unsigned char *in
, int inlen
, int ispkt
);
534 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
535 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
536 static void ssh_size(void);
537 static void ssh_special(Telnet_Special
);
538 static int ssh2_try_send(struct ssh_channel
*c
);
539 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
541 static void ssh_throttle_all(int enable
, int bufsize
);
542 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
543 static int (*s_rdpkt
) (unsigned char **data
, int *datalen
);
544 static int ssh_sendbuffer(void);
546 static struct rdpkt1_state_tag
{
547 long len
, pad
, biglen
, to_read
;
548 unsigned long realcrc
, gotcrc
;
554 static struct rdpkt2_state_tag
{
555 long len
, pad
, payload
, packetlen
, maclen
;
558 unsigned long incoming_sequence
;
561 static int ssh_channelcmp(void *av
, void *bv
)
563 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
564 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
565 if (a
->localid
< b
->localid
)
567 if (a
->localid
> b
->localid
)
571 static int ssh_channelfind(void *av
, void *bv
)
573 unsigned *a
= (unsigned *) av
;
574 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
582 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
584 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
585 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
587 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
588 return i
< 0 ?
-1 : +1;
589 if (a
->dport
> b
->dport
)
591 if (a
->dport
< b
->dport
)
596 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
598 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
599 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
601 if (a
->sport
> b
->sport
)
603 if (a
->sport
< b
->sport
)
608 static int alloc_channel_id(void)
610 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
611 unsigned low
, high
, mid
;
613 struct ssh_channel
*c
;
616 * First-fit allocation of channel numbers: always pick the
617 * lowest unused one. To do this, binary-search using the
618 * counted B-tree to find the largest channel ID which is in a
619 * contiguous sequence from the beginning. (Precisely
620 * everything in that sequence must have ID equal to its tree
621 * index plus CHANNEL_NUMBER_OFFSET.)
623 tsize
= count234(ssh_channels
);
627 while (high
- low
> 1) {
628 mid
= (high
+ low
) / 2;
629 c
= index234(ssh_channels
, mid
);
630 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
631 low
= mid
; /* this one is fine */
633 high
= mid
; /* this one is past it */
636 * Now low points to either -1, or the tree index of the
637 * largest ID in the initial sequence.
640 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
641 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
643 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
646 static void c_write(char *buf
, int len
)
648 if ((flags
& FLAG_STDERR
)) {
650 for (i
= 0; i
< len
; i
++)
652 fputc(buf
[i
], stderr
);
655 from_backend(1, buf
, len
);
658 static void c_write_untrusted(char *buf
, int len
)
661 for (i
= 0; i
< len
; i
++) {
664 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
669 static void c_write_str(char *buf
)
671 c_write(buf
, strlen(buf
));
675 * Collect incoming data in the incoming packet buffer.
676 * Decipher and verify the packet when it is completely read.
677 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
678 * Update the *data and *datalen variables.
679 * Return the additional nr of bytes needed, or 0 when
680 * a complete packet is available.
682 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
684 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
693 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
694 while ((*datalen
) == 0)
696 st
->len
= (st
->len
<< 8) + **data
;
697 (*data
)++, (*datalen
)--;
700 st
->pad
= 8 - (st
->len
% 8);
701 st
->biglen
= st
->len
+ st
->pad
;
702 pktin
.length
= st
->len
- 5;
704 if (pktin
.maxlen
< st
->biglen
) {
705 pktin
.maxlen
= st
->biglen
;
706 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
707 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
709 fatalbox("Out of memory");
712 st
->to_read
= st
->biglen
;
714 while (st
->to_read
> 0) {
715 st
->chunk
= st
->to_read
;
716 while ((*datalen
) == 0)
717 crReturn(st
->to_read
);
718 if (st
->chunk
> (*datalen
))
719 st
->chunk
= (*datalen
);
720 memcpy(st
->p
, *data
, st
->chunk
);
722 *datalen
-= st
->chunk
;
724 st
->to_read
-= st
->chunk
;
727 if (cipher
&& detect_attack(pktin
.data
, st
->biglen
, NULL
)) {
728 bombout(("Network attack (CRC compensation) detected!"));
733 cipher
->decrypt(pktin
.data
, st
->biglen
);
735 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
736 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
737 if (st
->gotcrc
!= st
->realcrc
) {
738 bombout(("Incorrect CRC received on packet"));
742 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
744 if (ssh1_compressing
) {
745 unsigned char *decompblk
;
747 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
748 &decompblk
, &decomplen
);
750 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
751 pktin
.maxlen
= st
->pad
+ decomplen
;
752 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
753 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
755 fatalbox("Out of memory");
758 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
760 pktin
.length
= decomplen
- 1;
763 pktin
.type
= pktin
.body
[-1];
765 log_packet(PKT_INCOMING
, pktin
.type
, ssh1_pkt_type(pktin
.type
),
766 pktin
.body
, pktin
.length
);
768 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
769 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
770 pktin
.type
== SSH1_MSG_DEBUG
||
771 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
772 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
773 long strlen
= GET_32BIT(pktin
.body
);
774 if (strlen
+ 4 != pktin
.length
) {
775 bombout(("Received data packet with bogus string length"));
780 if (pktin
.type
== SSH1_MSG_DEBUG
) {
781 /* log debug message */
783 int strlen
= GET_32BIT(pktin
.body
);
784 strcpy(buf
, "Remote: ");
787 memcpy(buf
+ 8, pktin
.body
+ 4, strlen
);
788 buf
[8 + strlen
] = '\0';
791 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
796 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
797 /* log reason code in disconnect message */
799 unsigned msglen
= GET_32BIT(pktin
.body
);
801 strcpy(buf
, "Remote sent disconnect: ");
802 nowlen
= strlen(buf
);
803 if (msglen
> sizeof(buf
) - nowlen
- 1)
804 msglen
= sizeof(buf
) - nowlen
- 1;
805 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
806 buf
[nowlen
+ msglen
] = '\0';
808 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
815 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
817 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
825 st
->cipherblk
= sccipher
->blksize
;
828 if (st
->cipherblk
< 8)
831 if (pktin
.maxlen
< st
->cipherblk
) {
832 pktin
.maxlen
= st
->cipherblk
;
835 NULL ?
smalloc(st
->cipherblk
+
836 APIEXTRA
) : srealloc(pktin
.data
,
840 fatalbox("Out of memory");
844 * Acquire and decrypt the first block of the packet. This will
845 * contain the length and padding details.
847 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
848 while ((*datalen
) == 0)
849 crReturn(st
->cipherblk
- st
->i
);
850 pktin
.data
[st
->i
] = *(*data
)++;
855 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
858 * Now get the length and padding figures.
860 st
->len
= GET_32BIT(pktin
.data
);
861 st
->pad
= pktin
.data
[4];
864 * This enables us to deduce the payload length.
866 st
->payload
= st
->len
- st
->pad
- 1;
868 pktin
.length
= st
->payload
+ 5;
871 * So now we can work out the total packet length.
873 st
->packetlen
= st
->len
+ 4;
874 st
->maclen
= scmac ? scmac
->len
: 0;
877 * Adjust memory allocation if packet is too big.
879 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
880 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
883 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
888 fatalbox("Out of memory");
892 * Read and decrypt the remainder of the packet.
894 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
896 while ((*datalen
) == 0)
897 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
898 pktin
.data
[st
->i
] = *(*data
)++;
901 /* Decrypt everything _except_ the MAC. */
903 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
904 st
->packetlen
- st
->cipherblk
);
910 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
911 st
->incoming_sequence
)) {
912 bombout(("Incorrect MAC received on packet"));
915 st
->incoming_sequence
++; /* whether or not we MACed */
918 * Decompress packet payload.
921 unsigned char *newpayload
;
923 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
924 &newpayload
, &newlen
)) {
925 if (pktin
.maxlen
< newlen
+ 5) {
926 pktin
.maxlen
= newlen
+ 5;
929 NULL ?
smalloc(pktin
.maxlen
+
930 APIEXTRA
) : srealloc(pktin
.data
,
934 fatalbox("Out of memory");
936 pktin
.length
= 5 + newlen
;
937 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
943 pktin
.type
= pktin
.data
[5];
945 log_packet(PKT_INCOMING
, pktin
.type
, ssh2_pkt_type(pktin
.type
),
946 pktin
.data
+6, pktin
.length
-6);
948 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
949 goto next_packet
; /* FIXME: print DEBUG message */
951 if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
952 /* log reason code in disconnect message */
954 int reason
= GET_32BIT(pktin
.data
+ 6);
955 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
957 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
958 sprintf(buf
, "Received disconnect message (%s)",
959 ssh2_disconnect_reasons
[reason
]);
961 sprintf(buf
, "Received disconnect message (unknown type %d)",
965 strcpy(buf
, "Disconnection message text: ");
966 nowlen
= strlen(buf
);
967 if (msglen
> sizeof(buf
) - nowlen
- 1)
968 msglen
= sizeof(buf
) - nowlen
- 1;
969 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
970 buf
[nowlen
+ msglen
] = '\0';
972 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
974 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
975 ssh2_disconnect_reasons
[reason
] : "unknown",
983 static void ssh1_pktout_size(int len
)
987 len
+= 5; /* type and CRC */
991 pktout
.length
= len
- 5;
992 if (pktout
.maxlen
< biglen
) {
993 pktout
.maxlen
= biglen
;
995 /* Allocate enough buffer space for extra block
996 * for MS CryptEncrypt() */
997 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
998 srealloc(pktout
.data
, biglen
+ 12));
1000 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
1001 srealloc(pktout
.data
, biglen
+ 4));
1004 fatalbox("Out of memory");
1006 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
1009 static void s_wrpkt_start(int type
, int len
)
1011 ssh1_pktout_size(len
);
1015 static int s_wrpkt_prepare(void)
1017 int pad
, len
, biglen
, i
;
1020 pktout
.body
[-1] = pktout
.type
;
1022 log_packet(PKT_OUTGOING
, pktout
.type
, ssh1_pkt_type(pktout
.type
),
1023 pktout
.body
, pktout
.length
);
1025 if (ssh1_compressing
) {
1026 unsigned char *compblk
;
1028 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
1029 &compblk
, &complen
);
1030 ssh1_pktout_size(complen
- 1);
1031 memcpy(pktout
.body
- 1, compblk
, complen
);
1035 len
= pktout
.length
+ 5; /* type and CRC */
1036 pad
= 8 - (len
% 8);
1039 for (i
= 0; i
< pad
; i
++)
1040 pktout
.data
[i
+ 4] = random_byte();
1041 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
1042 PUT_32BIT(pktout
.data
+ biglen
, crc
);
1043 PUT_32BIT(pktout
.data
, len
);
1046 cipher
->encrypt(pktout
.data
+ 4, biglen
);
1051 static void s_wrpkt(void)
1054 len
= s_wrpkt_prepare();
1055 backlog
= sk_write(s
, pktout
.data
, len
);
1056 if (backlog
> SSH_MAX_BACKLOG
)
1057 ssh_throttle_all(1, backlog
);
1060 static void s_wrpkt_defer(void)
1063 len
= s_wrpkt_prepare();
1064 if (deferred_len
+ len
> deferred_size
) {
1065 deferred_size
= deferred_len
+ len
+ 128;
1066 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1068 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1069 deferred_len
+= len
;
1073 * Construct a packet with the specified contents.
1075 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1077 unsigned char *p
, *argp
, argchar
;
1078 unsigned long argint
;
1079 int pktlen
, argtype
, arglen
;
1083 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1086 (void) va_arg(ap1
, int);
1090 (void) va_arg(ap1
, char);
1094 (void) va_arg(ap1
, unsigned char *);
1095 arglen
= va_arg(ap1
, int);
1099 argp
= va_arg(ap1
, unsigned char *);
1100 arglen
= strlen(argp
);
1101 pktlen
+= 4 + arglen
;
1104 bn
= va_arg(ap1
, Bignum
);
1105 pktlen
+= ssh1_bignum_length(bn
);
1112 s_wrpkt_start(pkttype
, pktlen
);
1115 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1118 argint
= va_arg(ap2
, int);
1119 PUT_32BIT(p
, argint
);
1123 argchar
= va_arg(ap2
, unsigned char);
1128 argp
= va_arg(ap2
, unsigned char *);
1129 arglen
= va_arg(ap2
, int);
1130 memcpy(p
, argp
, arglen
);
1134 argp
= va_arg(ap2
, unsigned char *);
1135 arglen
= strlen(argp
);
1136 PUT_32BIT(p
, arglen
);
1137 memcpy(p
+ 4, argp
, arglen
);
1141 bn
= va_arg(ap2
, Bignum
);
1142 p
+= ssh1_write_bignum(p
, bn
);
1148 static void send_packet(int pkttype
, ...)
1151 va_start(ap1
, pkttype
);
1152 va_start(ap2
, pkttype
);
1153 construct_packet(pkttype
, ap1
, ap2
);
1157 static void defer_packet(int pkttype
, ...)
1160 va_start(ap1
, pkttype
);
1161 va_start(ap2
, pkttype
);
1162 construct_packet(pkttype
, ap1
, ap2
);
1166 static int ssh_versioncmp(char *a
, char *b
)
1169 unsigned long av
, bv
;
1171 av
= strtoul(a
, &ae
, 10);
1172 bv
= strtoul(b
, &be
, 10);
1174 return (av
< bv ?
-1 : +1);
1179 av
= strtoul(ae
, &ae
, 10);
1180 bv
= strtoul(be
, &be
, 10);
1182 return (av
< bv ?
-1 : +1);
1188 * Utility routines for putting an SSH-protocol `string' and
1189 * `uint32' into a SHA state.
1192 static void sha_string(SHA_State
* s
, void *str
, int len
)
1194 unsigned char lenblk
[4];
1195 PUT_32BIT(lenblk
, len
);
1196 SHA_Bytes(s
, lenblk
, 4);
1197 SHA_Bytes(s
, str
, len
);
1200 static void sha_uint32(SHA_State
* s
, unsigned i
)
1202 unsigned char intblk
[4];
1203 PUT_32BIT(intblk
, i
);
1204 SHA_Bytes(s
, intblk
, 4);
1208 * SSH2 packet construction functions.
1210 static void ssh2_pkt_ensure(int length
)
1212 if (pktout
.maxlen
< length
) {
1213 pktout
.maxlen
= length
+ 256;
1216 NULL ?
smalloc(pktout
.maxlen
+
1217 APIEXTRA
) : srealloc(pktout
.data
,
1221 fatalbox("Out of memory");
1224 static void ssh2_pkt_adddata(void *data
, int len
)
1226 pktout
.length
+= len
;
1227 ssh2_pkt_ensure(pktout
.length
);
1228 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1230 static void ssh2_pkt_addbyte(unsigned char byte
)
1232 ssh2_pkt_adddata(&byte
, 1);
1234 static void ssh2_pkt_init(int pkt_type
)
1237 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1239 static void ssh2_pkt_addbool(unsigned char value
)
1241 ssh2_pkt_adddata(&value
, 1);
1243 static void ssh2_pkt_adduint32(unsigned long value
)
1246 PUT_32BIT(x
, value
);
1247 ssh2_pkt_adddata(x
, 4);
1249 static void ssh2_pkt_addstring_start(void)
1251 ssh2_pkt_adduint32(0);
1252 pktout
.savedpos
= pktout
.length
;
1254 static void ssh2_pkt_addstring_str(char *data
)
1256 ssh2_pkt_adddata(data
, strlen(data
));
1257 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1258 pktout
.length
- pktout
.savedpos
);
1260 static void ssh2_pkt_addstring_data(char *data
, int len
)
1262 ssh2_pkt_adddata(data
, len
);
1263 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1264 pktout
.length
- pktout
.savedpos
);
1266 static void ssh2_pkt_addstring(char *data
)
1268 ssh2_pkt_addstring_start();
1269 ssh2_pkt_addstring_str(data
);
1271 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1274 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1277 fatalbox("out of memory");
1279 for (i
= 1; i
<= n
; i
++)
1280 p
[i
] = bignum_byte(b
, n
- i
);
1282 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1284 memmove(p
, p
+ i
, n
+ 1 - i
);
1288 static void ssh2_pkt_addmp(Bignum b
)
1292 p
= ssh2_mpint_fmt(b
, &len
);
1293 ssh2_pkt_addstring_start();
1294 ssh2_pkt_addstring_data(p
, len
);
1299 * Construct an SSH2 final-form packet: compress it, encrypt it,
1300 * put the MAC on it. Final packet, ready to be sent, is stored in
1301 * pktout.data. Total length is returned.
1303 static int ssh2_pkt_construct(void)
1305 int cipherblk
, maclen
, padding
, i
;
1306 static unsigned long outgoing_sequence
= 0;
1308 log_packet(PKT_OUTGOING
, pktout
.data
[5], ssh2_pkt_type(pktout
.data
[5]),
1309 pktout
.data
+ 6, pktout
.length
- 6);
1312 * Compress packet payload.
1315 unsigned char *newpayload
;
1317 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1318 &newpayload
, &newlen
)) {
1320 ssh2_pkt_adddata(newpayload
, newlen
);
1326 * Add padding. At least four bytes, and must also bring total
1327 * length (minus MAC) up to a multiple of the block size.
1329 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1330 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1333 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1334 maclen
= csmac ? csmac
->len
: 0;
1335 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1336 pktout
.data
[4] = padding
;
1337 for (i
= 0; i
< padding
; i
++)
1338 pktout
.data
[pktout
.length
+ i
] = random_byte();
1339 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1341 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1343 outgoing_sequence
++; /* whether or not we MACed */
1346 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1348 /* Ready-to-send packet starts at pktout.data. We return length. */
1349 return pktout
.length
+ padding
+ maclen
;
1353 * Construct and send an SSH2 packet immediately.
1355 static void ssh2_pkt_send(void)
1359 len
= ssh2_pkt_construct();
1360 backlog
= sk_write(s
, pktout
.data
, len
);
1361 if (backlog
> SSH_MAX_BACKLOG
)
1362 ssh_throttle_all(1, backlog
);
1366 * Construct an SSH2 packet and add it to a deferred data block.
1367 * Useful for sending multiple packets in a single sk_write() call,
1368 * to prevent a traffic-analysing listener from being able to work
1369 * out the length of any particular packet (such as the password
1372 * Note that because SSH2 sequence-numbers its packets, this can
1373 * NOT be used as an m4-style `defer' allowing packets to be
1374 * constructed in one order and sent in another.
1376 static void ssh2_pkt_defer(void)
1378 int len
= ssh2_pkt_construct();
1379 if (deferred_len
+ len
> deferred_size
) {
1380 deferred_size
= deferred_len
+ len
+ 128;
1381 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1383 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1384 deferred_len
+= len
;
1388 * Send the whole deferred data block constructed by
1389 * ssh2_pkt_defer() or SSH1's defer_packet().
1391 static void ssh_pkt_defersend(void)
1394 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1395 deferred_len
= deferred_size
= 0;
1396 sfree(deferred_send_data
);
1397 deferred_send_data
= NULL
;
1398 if (backlog
> SSH_MAX_BACKLOG
)
1399 ssh_throttle_all(1, backlog
);
1403 void bndebug(char *string
, Bignum b
)
1407 p
= ssh2_mpint_fmt(b
, &len
);
1408 debug(("%s", string
));
1409 for (i
= 0; i
< len
; i
++)
1410 debug((" %02x", p
[i
]));
1416 static void sha_mpint(SHA_State
* s
, Bignum b
)
1420 p
= ssh2_mpint_fmt(b
, &len
);
1421 sha_string(s
, p
, len
);
1426 * SSH2 packet decode functions.
1428 static unsigned long ssh2_pkt_getuint32(void)
1430 unsigned long value
;
1431 if (pktin
.length
- pktin
.savedpos
< 4)
1432 return 0; /* arrgh, no way to decline (FIXME?) */
1433 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1434 pktin
.savedpos
+= 4;
1437 static int ssh2_pkt_getbool(void)
1439 unsigned long value
;
1440 if (pktin
.length
- pktin
.savedpos
< 1)
1441 return 0; /* arrgh, no way to decline (FIXME?) */
1442 value
= pktin
.data
[pktin
.savedpos
] != 0;
1446 static void ssh2_pkt_getstring(char **p
, int *length
)
1449 if (pktin
.length
- pktin
.savedpos
< 4)
1451 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1452 pktin
.savedpos
+= 4;
1453 if (pktin
.length
- pktin
.savedpos
< *length
)
1455 *p
= pktin
.data
+ pktin
.savedpos
;
1456 pktin
.savedpos
+= *length
;
1458 static Bignum
ssh2_pkt_getmp(void)
1464 ssh2_pkt_getstring(&p
, &length
);
1468 bombout(("internal error: Can't handle negative mpints"));
1471 b
= bignum_from_bytes(p
, length
);
1476 * Examine the remote side's version string and compare it against
1477 * a list of known buggy implementations.
1479 static void ssh_detect_bugs(char *vstring
)
1481 char *imp
; /* pointer to implementation part */
1483 imp
+= strcspn(imp
, "-");
1485 imp
+= strcspn(imp
, "-");
1488 ssh_remote_bugs
= 0;
1490 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1491 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1492 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1494 * These versions don't support SSH1_MSG_IGNORE, so we have
1495 * to use a different defence against password length
1498 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1499 logevent("We believe remote version has SSH1 ignore bug");
1502 if (!strcmp(imp
, "Cisco-1.25")) {
1504 * These versions need a plain password sent; they can't
1505 * handle having a null and a random length of data after
1508 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1509 logevent("We believe remote version needs a plain SSH1 password");
1512 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1513 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1514 !strncmp(imp
, "2.1 ", 4)) {
1516 * These versions have the HMAC bug.
1518 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1519 logevent("We believe remote version has SSH2 HMAC bug");
1523 static int do_ssh_init(unsigned char c
)
1526 static char version
[10];
1527 static char *vstring
;
1528 static int vstrsize
;
1534 /* Search for the string "SSH-" in the input. */
1537 static const int transS
[] = { 1, 2, 2, 1 };
1538 static const int transH
[] = { 0, 0, 3, 0 };
1539 static const int transminus
[] = { 0, 0, 0, -1 };
1550 crReturn(1); /* get another character */
1554 vstring
= smalloc(vstrsize
);
1555 strcpy(vstring
, "SSH-");
1559 crReturn(1); /* get another char */
1560 if (vslen
>= vstrsize
- 1) {
1562 vstring
= srealloc(vstring
, vstrsize
);
1564 vstring
[vslen
++] = c
;
1569 } else if (i
< sizeof(version
) - 1)
1571 } else if (c
== '\n')
1575 ssh_agentfwd_enabled
= FALSE
;
1576 rdpkt2_state
.incoming_sequence
= 0;
1579 vlog
= smalloc(20 + vslen
);
1580 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1581 sprintf(vlog
, "Server version: %s", vstring
);
1583 ssh_detect_bugs(vstring
);
1587 * Server version "1.99" means we can choose whether we use v1
1588 * or v2 protocol. Choice is based on cfg.sshprot.
1590 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1592 * This is a v2 server. Begin v2 protocol.
1594 char verstring
[80], vlog
[100];
1595 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1596 SHA_Init(&exhashbase
);
1598 * Hash our version string and their version string.
1600 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1601 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1602 sprintf(vlog
, "We claim version: %s", verstring
);
1604 strcat(verstring
, "\n");
1605 logevent("Using SSH protocol version 2");
1606 sk_write(s
, verstring
, strlen(verstring
));
1607 ssh_protocol
= ssh2_protocol
;
1609 s_rdpkt
= ssh2_rdpkt
;
1612 * This is a v1 server. Begin v1 protocol.
1614 char verstring
[80], vlog
[100];
1615 sprintf(verstring
, "SSH-%s-%s",
1616 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1618 sprintf(vlog
, "We claim version: %s", verstring
);
1620 strcat(verstring
, "\n");
1621 logevent("Using SSH protocol version 1");
1622 sk_write(s
, verstring
, strlen(verstring
));
1623 ssh_protocol
= ssh1_protocol
;
1625 s_rdpkt
= ssh1_rdpkt
;
1627 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1634 static void ssh_gotdata(unsigned char *data
, int datalen
)
1639 * To begin with, feed the characters one by one to the
1640 * protocol initialisation / selection function do_ssh_init().
1641 * When that returns 0, we're done with the initial greeting
1642 * exchange and can move on to packet discipline.
1647 crReturnV
; /* more data please */
1648 ret
= do_ssh_init(*data
);
1656 * We emerge from that loop when the initial negotiation is
1657 * over and we have selected an s_rdpkt function. Now pass
1658 * everything to s_rdpkt, and then pass the resulting packets
1659 * to the proper protocol handler.
1664 while (datalen
> 0) {
1665 if (s_rdpkt(&data
, &datalen
) == 0) {
1666 if (ssh_state
== SSH_STATE_CLOSED
) {
1669 ssh_protocol(NULL
, 0, 1);
1670 if (ssh_state
== SSH_STATE_CLOSED
) {
1680 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1683 ssh_state
= SSH_STATE_CLOSED
;
1689 /* A socket error has occurred. */
1690 connection_fatal(error_msg
);
1692 /* Otherwise, the remote side closed the connection normally. */
1697 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1699 ssh_gotdata(data
, len
);
1700 if (ssh_state
== SSH_STATE_CLOSED
) {
1710 static void ssh_sent(Plug plug
, int bufsize
)
1713 * If the send backlog on the SSH socket itself clears, we
1714 * should unthrottle the whole world if it was throttled.
1716 if (bufsize
< SSH_MAX_BACKLOG
)
1717 ssh_throttle_all(0, bufsize
);
1721 * Connect to specified host and port.
1722 * Returns an error message, or NULL on success.
1723 * Also places the canonical host name into `realhost'. It must be
1724 * freed by the caller.
1726 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1728 static struct plug_function_table fn_table
= {
1733 }, *fn_table_ptr
= &fn_table
;
1742 savedhost
= smalloc(1 + strlen(host
));
1744 fatalbox("Out of memory");
1745 strcpy(savedhost
, host
);
1748 port
= 22; /* default ssh port */
1763 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1766 addr
= sk_namelookup(host
, realhost
);
1767 if ((err
= sk_addr_error(addr
)))
1771 *realhost
= strdup(FWhost
);
1778 char buf
[200], addrbuf
[100];
1779 sk_getaddr(addr
, addrbuf
, 100);
1780 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1783 s
= sk_new(addr
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1784 if ((err
= sk_socket_error(s
)))
1788 sk_write(s
, "connect ", 8);
1789 sk_write(s
, FWhost
, strlen(FWhost
));
1792 sprintf(buf
, " %d\n", FWport
);
1793 sk_write(s
, buf
, strlen(buf
));
1801 * Throttle or unthrottle the SSH connection.
1803 static void ssh1_throttle(int adjust
)
1805 int old_count
= ssh1_throttle_count
;
1806 ssh1_throttle_count
+= adjust
;
1807 assert(ssh1_throttle_count
>= 0);
1808 if (ssh1_throttle_count
&& !old_count
) {
1809 sk_set_frozen(s
, 1);
1810 } else if (!ssh1_throttle_count
&& old_count
) {
1811 sk_set_frozen(s
, 0);
1816 * Throttle or unthrottle _all_ local data streams (for when sends
1817 * on the SSH connection itself back up).
1819 static void ssh_throttle_all(int enable
, int bufsize
)
1822 struct ssh_channel
*c
;
1824 if (enable
== ssh_throttled_all
)
1826 ssh_throttled_all
= enable
;
1827 ssh_overall_bufsize
= bufsize
;
1830 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
1832 case CHAN_MAINSESSION
:
1834 * This is treated separately, outside the switch.
1838 x11_override_throttle(c
->u
.x11
.s
, enable
);
1841 /* Agent channels require no buffer management. */
1844 pfd_override_throttle(c
->u
.x11
.s
, enable
);
1851 * Handle the key exchange and user authentication phases.
1853 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1857 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
1858 unsigned char cookie
[8];
1859 struct RSAKey servkey
, hostkey
;
1860 struct MD5Context md5c
;
1861 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1862 static int tried_publickey
, tried_agent
;
1863 static int tis_auth_refused
, ccard_auth_refused
;
1864 static unsigned char session_id
[16];
1865 static int cipher_type
;
1866 static char username
[100];
1867 static void *publickey_blob
;
1868 int publickey_bloblen
;
1875 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1876 bombout(("Public key packet not received"));
1880 logevent("Received public keys");
1882 memcpy(cookie
, pktin
.body
, 8);
1884 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1885 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
1888 * Log the host key fingerprint.
1892 logevent("Host key fingerprint is:");
1893 strcpy(logmsg
, " ");
1894 hostkey
.comment
= NULL
;
1895 rsa_fingerprint(logmsg
+ strlen(logmsg
),
1896 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
1900 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
1901 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
1902 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
1904 ssh1_local_protoflags
=
1905 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1906 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1909 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1910 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1911 MD5Update(&md5c
, pktin
.body
, 8);
1912 MD5Final(session_id
, &md5c
);
1914 for (i
= 0; i
< 32; i
++)
1915 session_key
[i
] = random_byte();
1917 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1919 rsabuf
= smalloc(len
);
1921 fatalbox("Out of memory");
1924 * Verify the host key.
1928 * First format the key into a string.
1930 int len
= rsastr_len(&hostkey
);
1931 char fingerprint
[100];
1932 char *keystr
= smalloc(len
);
1934 fatalbox("Out of memory");
1935 rsastr_fmt(keystr
, &hostkey
);
1936 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1937 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
1942 for (i
= 0; i
< 32; i
++) {
1943 rsabuf
[i
] = session_key
[i
];
1945 rsabuf
[i
] ^= session_id
[i
];
1948 if (hostkey
.bytes
> servkey
.bytes
) {
1949 rsaencrypt(rsabuf
, 32, &servkey
);
1950 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1952 rsaencrypt(rsabuf
, 32, &hostkey
);
1953 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1956 logevent("Encrypted session key");
1959 int cipher_chosen
= 0, warn
= 0;
1960 char *cipher_string
= NULL
;
1961 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
1962 int next_cipher
= cfg
.ssh_cipherlist
[i
];
1963 if (next_cipher
== CIPHER_WARN
) {
1964 /* If/when we choose a cipher, warn about it */
1966 } else if (next_cipher
== CIPHER_AES
) {
1967 /* XXX Probably don't need to mention this. */
1968 logevent("AES not supported in SSH1, skipping");
1970 switch (next_cipher
) {
1971 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
1972 cipher_string
= "3DES"; break;
1973 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
1974 cipher_string
= "Blowfish"; break;
1975 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
1976 cipher_string
= "single-DES"; break;
1978 if (supported_ciphers_mask
& (1 << cipher_type
))
1982 if (!cipher_chosen
) {
1983 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
1984 bombout(("Server violates SSH 1 protocol by not "
1985 "supporting 3DES encryption"));
1987 /* shouldn't happen */
1988 bombout(("No supported ciphers found"));
1992 /* Warn about chosen cipher if necessary. */
1994 askcipher(cipher_string
, 0);
1997 switch (cipher_type
) {
1998 case SSH_CIPHER_3DES
:
1999 logevent("Using 3DES encryption");
2001 case SSH_CIPHER_DES
:
2002 logevent("Using single-DES encryption");
2004 case SSH_CIPHER_BLOWFISH
:
2005 logevent("Using Blowfish encryption");
2009 send_packet(SSH1_CMSG_SESSION_KEY
,
2010 PKT_CHAR
, cipher_type
,
2011 PKT_DATA
, cookie
, 8,
2012 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
2013 PKT_DATA
, rsabuf
, len
,
2014 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
2016 logevent("Trying to enable encryption...");
2020 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2021 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
2022 cipher
->sesskey(session_key
);
2026 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2027 bombout(("Encryption not successfully enabled"));
2031 logevent("Successfully started encryption");
2037 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2039 if (!ssh_get_line("login as: ",
2040 username
, sizeof(username
), FALSE
)) {
2042 * get_line failed to get a username.
2045 logevent("No username provided. Abandoning session.");
2046 ssh_state
= SSH_STATE_CLOSED
;
2050 c_write_str("login as: ");
2053 crWaitUntil(!ispkt
);
2055 switch (c
= *in
++) {
2064 c_write_str("\b \b");
2071 c_write_str("\b \b");
2081 if (((c
>= ' ' && c
<= '~') ||
2082 ((unsigned char) c
>= 160))
2083 && pos
< sizeof(username
)-1) {
2084 username
[pos
++] = c
;
2090 c_write_str("\r\n");
2091 username
[strcspn(username
, "\n\r")] = '\0';
2094 strncpy(username
, cfg
.username
, 99);
2095 username
[99] = '\0';
2098 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2100 char userlog
[22 + sizeof(username
)];
2101 sprintf(userlog
, "Sent username \"%s\"", username
);
2103 if (flags
& FLAG_INTERACTIVE
&&
2104 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2105 strcat(userlog
, "\r\n");
2106 c_write_str(userlog
);
2113 tried_publickey
= tried_agent
= 0;
2114 tis_auth_refused
= ccard_auth_refused
= 0;
2115 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2117 if (!rsakey_pubblob(cfg
.keyfile
, &publickey_blob
, &publickey_bloblen
))
2118 publickey_blob
= NULL
;
2120 publickey_blob
= NULL
;
2122 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2123 static char password
[100];
2124 static char prompt
[200];
2127 static int pwpkt_type
;
2128 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2130 if (agent_exists() && !tried_agent
) {
2132 * Attempt RSA authentication using Pageant.
2134 static unsigned char request
[5], *response
, *p
;
2135 static int responselen
;
2136 static int i
, nkeys
;
2137 static int authed
= FALSE
;
2141 logevent("Pageant is running. Requesting keys.");
2143 /* Request the keys held by the agent. */
2144 PUT_32BIT(request
, 1);
2145 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2146 agent_query(request
, 5, &r
, &responselen
);
2147 response
= (unsigned char *) r
;
2148 if (response
&& responselen
>= 5 &&
2149 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2151 nkeys
= GET_32BIT(p
);
2155 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2158 for (i
= 0; i
< nkeys
; i
++) {
2159 static struct RSAKey key
;
2160 static Bignum challenge
;
2161 static char *commentp
;
2162 static int commentlen
;
2166 sprintf(buf
, "Trying Pageant key #%d", i
);
2169 if (publickey_blob
&&
2170 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
2171 logevent("This key matches configured key file");
2172 tried_publickey
= 1;
2175 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2176 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2177 commentlen
= GET_32BIT(p
);
2181 send_packet(SSH1_CMSG_AUTH_RSA
,
2182 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2184 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2185 logevent("Key refused");
2188 logevent("Received RSA challenge");
2189 ssh1_read_bignum(pktin
.body
, &challenge
);
2191 char *agentreq
, *q
, *ret
;
2194 len
= 1 + 4; /* message type, bit count */
2195 len
+= ssh1_bignum_length(key
.exponent
);
2196 len
+= ssh1_bignum_length(key
.modulus
);
2197 len
+= ssh1_bignum_length(challenge
);
2198 len
+= 16; /* session id */
2199 len
+= 4; /* response format */
2200 agentreq
= smalloc(4 + len
);
2201 PUT_32BIT(agentreq
, len
);
2203 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2204 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2206 q
+= ssh1_write_bignum(q
, key
.exponent
);
2207 q
+= ssh1_write_bignum(q
, key
.modulus
);
2208 q
+= ssh1_write_bignum(q
, challenge
);
2209 memcpy(q
, session_id
, 16);
2211 PUT_32BIT(q
, 1); /* response format */
2212 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2216 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2217 logevent("Sending Pageant's response");
2218 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2219 PKT_DATA
, ret
+ 5, 16,
2223 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2225 ("Pageant's response accepted");
2226 if (flags
& FLAG_VERBOSE
) {
2228 ("Authenticated using RSA key \"");
2229 c_write(commentp
, commentlen
);
2230 c_write_str("\" from agent\r\n");
2235 ("Pageant's response not accepted");
2238 ("Pageant failed to answer challenge");
2242 logevent("No reply received from Pageant");
2245 freebn(key
.exponent
);
2246 freebn(key
.modulus
);
2255 if (*cfg
.keyfile
&& !tried_publickey
)
2256 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2258 if (cfg
.try_tis_auth
&&
2259 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2260 !tis_auth_refused
) {
2261 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2262 logevent("Requested TIS authentication");
2263 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2265 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2266 logevent("TIS authentication declined");
2267 if (flags
& FLAG_INTERACTIVE
)
2268 c_write_str("TIS authentication refused.\r\n");
2269 tis_auth_refused
= 1;
2272 int challengelen
= ((pktin
.body
[0] << 24) |
2273 (pktin
.body
[1] << 16) |
2274 (pktin
.body
[2] << 8) |
2276 logevent("Received TIS challenge");
2277 if (challengelen
> sizeof(prompt
) - 1)
2278 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2279 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2280 /* Prompt heuristic comes from OpenSSH */
2281 strncpy(prompt
+ challengelen
,
2282 memchr(prompt
, '\n', challengelen
) ?
2283 "": "\r\nResponse: ",
2284 (sizeof prompt
) - challengelen
);
2285 prompt
[(sizeof prompt
) - 1] = '\0';
2288 if (cfg
.try_tis_auth
&&
2289 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2290 !ccard_auth_refused
) {
2291 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2292 logevent("Requested CryptoCard authentication");
2293 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2295 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2296 logevent("CryptoCard authentication declined");
2297 c_write_str("CryptoCard authentication refused.\r\n");
2298 ccard_auth_refused
= 1;
2301 int challengelen
= ((pktin
.body
[0] << 24) |
2302 (pktin
.body
[1] << 16) |
2303 (pktin
.body
[2] << 8) |
2305 logevent("Received CryptoCard challenge");
2306 if (challengelen
> sizeof(prompt
) - 1)
2307 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2308 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2309 strncpy(prompt
+ challengelen
,
2310 memchr(prompt
, '\n', challengelen
) ?
2311 "" : "\r\nResponse: ",
2312 sizeof(prompt
) - challengelen
);
2313 prompt
[sizeof(prompt
) - 1] = '\0';
2316 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2317 sprintf(prompt
, "%.90s@%.90s's password: ",
2318 username
, savedhost
);
2320 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2321 char *comment
= NULL
;
2322 if (flags
& FLAG_VERBOSE
)
2323 c_write_str("Trying public key authentication.\r\n");
2324 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2325 if (flags
& FLAG_VERBOSE
)
2326 c_write_str("No passphrase required.\r\n");
2329 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2334 * Show password prompt, having first obtained it via a TIS
2335 * or CryptoCard exchange if we're doing TIS or CryptoCard
2339 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2341 * get_line failed to get a password (for example
2342 * because one was supplied on the command line
2343 * which has already failed to work). Terminate.
2345 send_packet(SSH1_MSG_DISCONNECT
,
2346 PKT_STR
, "No more passwords available to try",
2348 connection_fatal("Unable to authenticate");
2349 ssh_state
= SSH_STATE_CLOSED
;
2353 /* Prompt may have come from server. We've munged it a bit, so
2354 * we know it to be zero-terminated at least once. */
2355 c_write_untrusted(prompt
, strlen(prompt
));
2359 crWaitUntil(!ispkt
);
2361 switch (c
= *in
++) {
2382 if (pos
< sizeof(password
)-1)
2383 password
[pos
++] = c
;
2387 c_write_str("\r\n");
2391 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2393 * Try public key authentication with the specified
2396 static struct RSAKey pubkey
;
2397 static Bignum challenge
, response
;
2399 static unsigned char buffer
[32];
2401 tried_publickey
= 1;
2402 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2404 c_write_str("Couldn't load private key from ");
2405 c_write_str(cfg
.keyfile
);
2406 c_write_str(".\r\n");
2407 continue; /* go and try password */
2410 c_write_str("Wrong passphrase.\r\n");
2411 tried_publickey
= 0;
2412 continue; /* try again */
2416 * Send a public key attempt.
2418 send_packet(SSH1_CMSG_AUTH_RSA
,
2419 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2422 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2423 c_write_str("Server refused our public key.\r\n");
2424 continue; /* go and try password */
2426 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2427 bombout(("Bizarre response to offer of public key"));
2430 ssh1_read_bignum(pktin
.body
, &challenge
);
2431 response
= rsadecrypt(challenge
, &pubkey
);
2432 freebn(pubkey
.private_exponent
); /* burn the evidence */
2434 for (i
= 0; i
< 32; i
++) {
2435 buffer
[i
] = bignum_byte(response
, 31 - i
);
2439 MD5Update(&md5c
, buffer
, 32);
2440 MD5Update(&md5c
, session_id
, 16);
2441 MD5Final(buffer
, &md5c
);
2443 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2444 PKT_DATA
, buffer
, 16, PKT_END
);
2447 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2448 if (flags
& FLAG_VERBOSE
)
2450 ("Failed to authenticate with our public key.\r\n");
2451 continue; /* go and try password */
2452 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2454 ("Bizarre response to RSA authentication response"));
2458 break; /* we're through! */
2460 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2462 * Defence against traffic analysis: we send a
2463 * whole bunch of packets containing strings of
2464 * different lengths. One of these strings is the
2465 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2466 * The others are all random data in
2467 * SSH1_MSG_IGNORE packets. This way a passive
2468 * listener can't tell which is the password, and
2469 * hence can't deduce the password length.
2471 * Anybody with a password length greater than 16
2472 * bytes is going to have enough entropy in their
2473 * password that a listener won't find it _that_
2474 * much help to know how long it is. So what we'll
2477 * - if password length < 16, we send 15 packets
2478 * containing string lengths 1 through 15
2480 * - otherwise, we let N be the nearest multiple
2481 * of 8 below the password length, and send 8
2482 * packets containing string lengths N through
2483 * N+7. This won't obscure the order of
2484 * magnitude of the password length, but it will
2485 * introduce a bit of extra uncertainty.
2487 * A few servers (the old 1.2.18 through 1.2.22)
2488 * can't deal with SSH1_MSG_IGNORE. For these
2489 * servers, we need an alternative defence. We make
2490 * use of the fact that the password is interpreted
2491 * as a C string: so we can append a NUL, then some
2494 * One server (a Cisco one) can deal with neither
2495 * SSH1_MSG_IGNORE _nor_ a padded password string.
2496 * For this server we are left with no defences
2497 * against password length sniffing.
2499 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2501 * The server can deal with SSH1_MSG_IGNORE, so
2502 * we can use the primary defence.
2504 int bottom
, top
, pwlen
, i
;
2507 pwlen
= strlen(password
);
2509 bottom
= 0; /* zero length passwords are OK! :-) */
2512 bottom
= pwlen
& ~7;
2516 assert(pwlen
>= bottom
&& pwlen
<= top
);
2518 randomstr
= smalloc(top
+ 1);
2520 for (i
= bottom
; i
<= top
; i
++) {
2522 defer_packet(pwpkt_type
, PKT_STR
, password
,
2525 for (j
= 0; j
< i
; j
++) {
2527 randomstr
[j
] = random_byte();
2528 } while (randomstr
[j
] == '\0');
2530 randomstr
[i
] = '\0';
2531 defer_packet(SSH1_MSG_IGNORE
,
2532 PKT_STR
, randomstr
, PKT_END
);
2535 logevent("Sending password with camouflage packets");
2536 ssh_pkt_defersend();
2538 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2540 * The server can't deal with SSH1_MSG_IGNORE
2541 * but can deal with padded passwords, so we
2542 * can use the secondary defence.
2548 len
= strlen(password
);
2549 if (len
< sizeof(string
)) {
2551 strcpy(string
, password
);
2552 len
++; /* cover the zero byte */
2553 while (len
< sizeof(string
)) {
2554 string
[len
++] = (char) random_byte();
2559 logevent("Sending length-padded password");
2560 send_packet(pwpkt_type
, PKT_INT
, len
,
2561 PKT_DATA
, s
, len
, PKT_END
);
2564 * The server has _both_
2565 * BUG_CHOKES_ON_SSH1_IGNORE and
2566 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2567 * therefore nothing we can do.
2570 len
= strlen(password
);
2571 logevent("Sending unpadded password");
2572 send_packet(pwpkt_type
, PKT_INT
, len
,
2573 PKT_DATA
, password
, len
, PKT_END
);
2576 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2579 logevent("Sent password");
2580 memset(password
, 0, strlen(password
));
2582 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2583 if (flags
& FLAG_VERBOSE
)
2584 c_write_str("Access denied\r\n");
2585 logevent("Authentication refused");
2586 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2587 logevent("Received disconnect request");
2588 ssh_state
= SSH_STATE_CLOSED
;
2590 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2591 bombout(("Strange packet received, type %d", pktin
.type
));
2596 logevent("Authentication successful");
2601 void sshfwd_close(struct ssh_channel
*c
)
2603 if (c
&& !c
->closes
) {
2605 * If the channel's remoteid is -1, we have sent
2606 * CHANNEL_OPEN for this channel, but it hasn't even been
2607 * acknowledged by the server. So we must set a close flag
2608 * on it now, and then when the server acks the channel
2609 * open, we can close it then.
2611 if (c
->remoteid
!= -1) {
2612 if (ssh_version
== 1) {
2613 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2616 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2617 ssh2_pkt_adduint32(c
->remoteid
);
2622 if (c
->type
== CHAN_X11
) {
2624 logevent("Forwarded X11 connection terminated");
2625 } else if (c
->type
== CHAN_SOCKDATA
||
2626 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2628 logevent("Forwarded port closed");
2633 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2635 if (ssh_version
== 1) {
2636 send_packet(SSH1_MSG_CHANNEL_DATA
,
2637 PKT_INT
, c
->remoteid
,
2638 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2640 * In SSH1 we can return 0 here - implying that forwarded
2641 * connections are never individually throttled - because
2642 * the only circumstance that can cause throttling will be
2643 * the whole SSH connection backing up, in which case
2644 * _everything_ will be throttled as a whole.
2648 ssh2_add_channel_data(c
, buf
, len
);
2649 return ssh2_try_send(c
);
2653 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2655 if (ssh_version
== 1) {
2656 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2657 c
->v
.v1
.throttling
= 0;
2661 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2665 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2671 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2674 if (ssh_state
== SSH_STATE_CLOSED
)
2677 if (cfg
.agentfwd
&& agent_exists()) {
2678 logevent("Requesting agent forwarding");
2679 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2683 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2684 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2685 bombout(("Protocol confusion"));
2687 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2688 logevent("Agent forwarding refused");
2690 logevent("Agent forwarding enabled");
2691 ssh_agentfwd_enabled
= TRUE
;
2695 if (cfg
.x11_forward
) {
2696 char proto
[20], data
[64];
2697 logevent("Requesting X11 forwarding");
2698 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2699 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2700 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2701 PKT_STR
, proto
, PKT_STR
, data
,
2702 PKT_INT
, 0, PKT_END
);
2704 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2705 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2710 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2711 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2712 bombout(("Protocol confusion"));
2714 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2715 logevent("X11 forwarding refused");
2717 logevent("X11 forwarding enabled");
2718 ssh_X11_fwd_enabled
= TRUE
;
2726 char sports
[256], dports
[256], host
[256];
2729 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2730 /* Add port forwardings. */
2735 while (*e
&& *e
!= '\t')
2741 while (*e
&& *e
!= ':')
2751 dport
= atoi(dports
);
2752 sport
= atoi(sports
);
2753 if (sport
&& dport
) {
2755 pfd_addforward(host
, dport
, sport
);
2756 sprintf(buf
, "Local port %d forwarding to %s:%d",
2757 sport
, host
, dport
);
2760 struct ssh_rportfwd
*pf
;
2761 pf
= smalloc(sizeof(*pf
));
2762 strcpy(pf
->dhost
, host
);
2764 if (add234(ssh_rportfwds
, pf
) != pf
) {
2766 "Duplicate remote port forwarding to %s:%d",
2771 sprintf(buf
, "Requesting remote port %d forward to %s:%d",
2772 sport
, host
, dport
);
2774 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2786 send_packet(SSH1_CMSG_REQUEST_PTY
,
2787 PKT_STR
, cfg
.termtype
,
2788 PKT_INT
, rows
, PKT_INT
, cols
,
2789 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2790 ssh_state
= SSH_STATE_INTERMED
;
2794 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2795 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2796 bombout(("Protocol confusion"));
2798 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2799 c_write_str("Server refused to allocate pty\r\n");
2800 ssh_editing
= ssh_echoing
= 1;
2802 logevent("Allocated pty");
2804 ssh_editing
= ssh_echoing
= 1;
2807 if (cfg
.compression
) {
2808 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2812 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2813 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2814 bombout(("Protocol confusion"));
2816 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2817 c_write_str("Server refused to compress\r\n");
2819 logevent("Started compression");
2820 ssh1_compressing
= TRUE
;
2821 zlib_compress_init();
2822 zlib_decompress_init();
2826 * Start the shell or command.
2828 * Special case: if the first-choice command is an SSH2
2829 * subsystem (hence not usable here) and the second choice
2830 * exists, we fall straight back to that.
2833 char *cmd
= cfg
.remote_cmd_ptr
;
2835 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
2836 cmd
= cfg
.remote_cmd_ptr2
;
2837 ssh_fallback_cmd
= TRUE
;
2840 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2842 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2843 logevent("Started session");
2846 ssh_state
= SSH_STATE_SESSION
;
2850 ssh_special(TS_EOF
);
2852 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
2854 ssh_channels
= newtree234(ssh_channelcmp
);
2858 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2859 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2860 long len
= GET_32BIT(pktin
.body
);
2862 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2863 pktin
.body
+ 4, len
);
2864 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2865 ssh1_stdout_throttling
= 1;
2868 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2869 ssh_state
= SSH_STATE_CLOSED
;
2870 logevent("Received disconnect request");
2872 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2873 /* Remote side is trying to open a channel to talk to our
2874 * X-Server. Give them back a local channel number. */
2875 struct ssh_channel
*c
;
2877 logevent("Received X11 connect request");
2878 /* Refuse if X11 forwarding is disabled. */
2879 if (!ssh_X11_fwd_enabled
) {
2880 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2881 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2882 logevent("Rejected X11 connect request");
2884 c
= smalloc(sizeof(struct ssh_channel
));
2886 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2887 logevent("opening X11 forward connection failed");
2889 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2890 PKT_INT
, GET_32BIT(pktin
.body
),
2894 ("opening X11 forward connection succeeded");
2895 c
->remoteid
= GET_32BIT(pktin
.body
);
2896 c
->localid
= alloc_channel_id();
2898 c
->v
.v1
.throttling
= 0;
2899 c
->type
= CHAN_X11
; /* identify channel type */
2900 add234(ssh_channels
, c
);
2901 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2902 PKT_INT
, c
->remoteid
, PKT_INT
,
2903 c
->localid
, PKT_END
);
2904 logevent("Opened X11 forward channel");
2907 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2908 /* Remote side is trying to open a channel to talk to our
2909 * agent. Give them back a local channel number. */
2910 struct ssh_channel
*c
;
2912 /* Refuse if agent forwarding is disabled. */
2913 if (!ssh_agentfwd_enabled
) {
2914 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2915 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2917 c
= smalloc(sizeof(struct ssh_channel
));
2918 c
->remoteid
= GET_32BIT(pktin
.body
);
2919 c
->localid
= alloc_channel_id();
2921 c
->v
.v1
.throttling
= 0;
2922 c
->type
= CHAN_AGENT
; /* identify channel type */
2923 c
->u
.a
.lensofar
= 0;
2924 add234(ssh_channels
, c
);
2925 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2926 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2929 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
2930 /* Remote side is trying to open a channel to talk to a
2931 * forwarded port. Give them back a local channel number. */
2932 struct ssh_channel
*c
;
2933 struct ssh_rportfwd pf
;
2935 char host
[256], buf
[1024];
2937 c
= smalloc(sizeof(struct ssh_channel
));
2939 hostsize
= GET_32BIT(pktin
.body
+4);
2940 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
2941 if (h
+1 < host
+sizeof(host
))
2946 port
= GET_32BIT(p
);
2948 strcpy(pf
.dhost
, host
);
2951 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
2952 sprintf(buf
, "Rejected remote port open request for %s:%d",
2955 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2956 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2958 sprintf(buf
, "Received remote port open request for %s:%d",
2961 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
2964 sprintf(buf
, "Port open failed: %s", e
);
2967 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2968 PKT_INT
, GET_32BIT(pktin
.body
),
2971 c
->remoteid
= GET_32BIT(pktin
.body
);
2972 c
->localid
= alloc_channel_id();
2974 c
->v
.v1
.throttling
= 0;
2975 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
2976 add234(ssh_channels
, c
);
2977 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2978 PKT_INT
, c
->remoteid
, PKT_INT
,
2979 c
->localid
, PKT_END
);
2980 logevent("Forwarded port opened successfully");
2984 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2985 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2986 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2987 struct ssh_channel
*c
;
2989 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2990 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2991 c
->remoteid
= localid
;
2992 c
->type
= CHAN_SOCKDATA
;
2993 c
->v
.v1
.throttling
= 0;
2994 pfd_confirm(c
->u
.pfd
.s
);
2997 if (c
&& c
->closes
) {
2999 * We have a pending close on this channel,
3000 * which we decided on before the server acked
3001 * the channel open. So now we know the
3002 * remoteid, we can close it again.
3004 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
3008 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3009 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3010 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3011 struct ssh_channel
*c
;
3013 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3014 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3015 logevent("Forwarded connection refused by server");
3016 pfd_close(c
->u
.pfd
.s
);
3017 del234(ssh_channels
, c
);
3021 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3022 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3023 /* Remote side closes a channel. */
3024 unsigned i
= GET_32BIT(pktin
.body
);
3025 struct ssh_channel
*c
;
3026 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3030 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3031 if (!(c
->closes
& closetype
))
3032 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
3034 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3035 logevent("Forwarded X11 connection terminated");
3036 assert(c
->u
.x11
.s
!= NULL
);
3037 x11_close(c
->u
.x11
.s
);
3040 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3041 logevent("Forwarded port closed");
3042 assert(c
->u
.pfd
.s
!= NULL
);
3043 pfd_close(c
->u
.pfd
.s
);
3046 c
->closes
|= closetype
;
3047 if (c
->closes
== 3) {
3048 del234(ssh_channels
, c
);
3052 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3053 /* Data sent down one of our channels. */
3054 int i
= GET_32BIT(pktin
.body
);
3055 int len
= GET_32BIT(pktin
.body
+ 4);
3056 unsigned char *p
= pktin
.body
+ 8;
3057 struct ssh_channel
*c
;
3058 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3063 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3066 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3069 /* Data for an agent message. Buffer it. */
3071 if (c
->u
.a
.lensofar
< 4) {
3072 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3073 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3077 c
->u
.a
.lensofar
+= l
;
3079 if (c
->u
.a
.lensofar
== 4) {
3081 4 + GET_32BIT(c
->u
.a
.msglen
);
3082 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3083 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3085 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3087 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3089 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3093 c
->u
.a
.lensofar
+= l
;
3095 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3096 void *reply
, *sentreply
;
3098 agent_query(c
->u
.a
.message
,
3099 c
->u
.a
.totallen
, &reply
,
3104 /* Fake SSH_AGENT_FAILURE. */
3105 sentreply
= "\0\0\0\1\5";
3108 send_packet(SSH1_MSG_CHANNEL_DATA
,
3109 PKT_INT
, c
->remoteid
,
3111 PKT_DATA
, sentreply
, replylen
,
3115 sfree(c
->u
.a
.message
);
3116 c
->u
.a
.lensofar
= 0;
3119 bufsize
= 0; /* agent channels never back up */
3122 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3123 c
->v
.v1
.throttling
= 1;
3127 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3128 /* may be from EXEC_SHELL on some servers */
3129 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3130 /* may be from EXEC_SHELL on some servers
3131 * if no pty is available or in other odd cases. Ignore */
3132 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3134 ssh_exitcode
= GET_32BIT(pktin
.body
);
3135 sprintf(buf
, "Server sent command exit status %d",
3138 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3140 * In case `helpful' firewalls or proxies tack
3141 * extra human-readable text on the end of the
3142 * session which we might mistake for another
3143 * encrypted packet, we close the session once
3144 * we've sent EXIT_CONFIRMATION.
3146 ssh_state
= SSH_STATE_CLOSED
;
3149 bombout(("Strange packet received: type %d", pktin
.type
));
3154 int len
= min(inlen
, 512);
3155 send_packet(SSH1_CMSG_STDIN_DATA
,
3156 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3167 * Utility routine for decoding comma-separated strings in KEXINIT.
3169 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3171 int needlen
= strlen(needle
);
3174 * Is it at the start of the string?
3176 if (haylen
>= needlen
&& /* haystack is long enough */
3177 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3178 (haylen
== needlen
|| haystack
[needlen
] == ',')
3179 /* either , or EOS follows */
3183 * If not, search for the next comma and resume after that.
3184 * If no comma found, terminate.
3186 while (haylen
> 0 && *haystack
!= ',')
3187 haylen
--, haystack
++;
3190 haylen
--, haystack
++; /* skip over comma itself */
3195 * SSH2 key creation method.
3197 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3201 /* First 20 bytes. */
3204 SHA_Bytes(&s
, H
, 20);
3205 SHA_Bytes(&s
, &chr
, 1);
3206 SHA_Bytes(&s
, sessid
, 20);
3207 SHA_Final(&s
, keyspace
);
3208 /* Next 20 bytes. */
3211 SHA_Bytes(&s
, H
, 20);
3212 SHA_Bytes(&s
, keyspace
, 20);
3213 SHA_Final(&s
, keyspace
+ 20);
3217 * Handle the SSH2 transport layer.
3219 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3221 static int i
, j
, len
, nbits
, pbits
, warn
;
3223 static Bignum p
, g
, e
, f
, K
;
3224 static int kex_init_value
, kex_reply_value
;
3225 static const struct ssh_mac
**maclist
;
3227 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3228 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3229 static const struct ssh_mac
*csmac_tobe
= NULL
;
3230 static const struct ssh_mac
*scmac_tobe
= NULL
;
3231 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3232 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3233 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3234 static int hostkeylen
, siglen
;
3235 static void *hkey
; /* actual host key */
3236 static unsigned char exchange_hash
[20];
3237 static unsigned char keyspace
[40];
3238 static int n_preferred_ciphers
;
3239 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3240 static const struct ssh_compress
*preferred_comp
;
3241 static int cipherstr_started
;
3242 static int first_kex
;
3249 * Set up the preferred ciphers. (NULL => warn below here)
3251 n_preferred_ciphers
= 0;
3252 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3253 switch (cfg
.ssh_cipherlist
[i
]) {
3254 case CIPHER_BLOWFISH
:
3255 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3256 n_preferred_ciphers
++;
3259 if (cfg
.ssh2_des_cbc
) {
3260 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3261 n_preferred_ciphers
++;
3265 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3266 n_preferred_ciphers
++;
3269 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3270 n_preferred_ciphers
++;
3273 /* Flag for later. Don't bother if it's the last in
3275 if (i
< CIPHER_MAX
- 1) {
3276 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3277 n_preferred_ciphers
++;
3284 * Set up preferred compression.
3286 if (cfg
.compression
)
3287 preferred_comp
= &ssh_zlib
;
3289 preferred_comp
= &ssh_comp_none
;
3292 * Be prepared to work around the buggy MAC problem.
3294 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3295 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3297 maclist
= macs
, nmacs
= lenof(macs
);
3301 * Construct and send our key exchange packet.
3303 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3304 for (i
= 0; i
< 16; i
++)
3305 ssh2_pkt_addbyte((unsigned char) random_byte());
3306 /* List key exchange algorithms. */
3307 ssh2_pkt_addstring_start();
3308 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3309 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3310 if (i
< lenof(kex_algs
) - 1)
3311 ssh2_pkt_addstring_str(",");
3313 /* List server host key algorithms. */
3314 ssh2_pkt_addstring_start();
3315 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3316 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3317 if (i
< lenof(hostkey_algs
) - 1)
3318 ssh2_pkt_addstring_str(",");
3320 /* List client->server encryption algorithms. */
3321 ssh2_pkt_addstring_start();
3322 cipherstr_started
= 0;
3323 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3324 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3325 if (!c
) continue; /* warning flag */
3326 for (j
= 0; j
< c
->nciphers
; j
++) {
3327 if (cipherstr_started
)
3328 ssh2_pkt_addstring_str(",");
3329 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3330 cipherstr_started
= 1;
3333 /* List server->client encryption algorithms. */
3334 ssh2_pkt_addstring_start();
3335 cipherstr_started
= 0;
3336 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3337 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3338 if (!c
) continue; /* warning flag */
3339 for (j
= 0; j
< c
->nciphers
; j
++) {
3340 if (cipherstr_started
)
3341 ssh2_pkt_addstring_str(",");
3342 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3343 cipherstr_started
= 1;
3346 /* List client->server MAC algorithms. */
3347 ssh2_pkt_addstring_start();
3348 for (i
= 0; i
< nmacs
; i
++) {
3349 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3351 ssh2_pkt_addstring_str(",");
3353 /* List server->client MAC algorithms. */
3354 ssh2_pkt_addstring_start();
3355 for (i
= 0; i
< nmacs
; i
++) {
3356 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3358 ssh2_pkt_addstring_str(",");
3360 /* List client->server compression algorithms. */
3361 ssh2_pkt_addstring_start();
3362 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3363 const struct ssh_compress
*c
=
3364 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3365 ssh2_pkt_addstring_str(c
->name
);
3366 if (i
< lenof(compressions
))
3367 ssh2_pkt_addstring_str(",");
3369 /* List server->client compression algorithms. */
3370 ssh2_pkt_addstring_start();
3371 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3372 const struct ssh_compress
*c
=
3373 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3374 ssh2_pkt_addstring_str(c
->name
);
3375 if (i
< lenof(compressions
))
3376 ssh2_pkt_addstring_str(",");
3378 /* List client->server languages. Empty list. */
3379 ssh2_pkt_addstring_start();
3380 /* List server->client languages. Empty list. */
3381 ssh2_pkt_addstring_start();
3382 /* First KEX packet does _not_ follow, because we're not that brave. */
3383 ssh2_pkt_addbool(FALSE
);
3385 ssh2_pkt_adduint32(0);
3387 exhash
= exhashbase
;
3388 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3394 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3397 * Now examine the other side's KEXINIT to see what we're up
3400 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3401 bombout(("expected key exchange packet from server"));
3406 cscipher_tobe
= NULL
;
3407 sccipher_tobe
= NULL
;
3412 pktin
.savedpos
+= 16; /* skip garbage cookie */
3413 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3414 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3415 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3420 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3421 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3422 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3423 hostkey
= hostkey_algs
[i
];
3427 ssh2_pkt_getstring(&str
, &len
); /* client->server 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 cscipher_tobe
= c
->list
[j
];
3441 if (cscipher_tobe
) {
3443 askcipher(cscipher_tobe
->name
, 1);
3447 if (!cscipher_tobe
) {
3448 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3452 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3454 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3455 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3459 for (j
= 0; j
< c
->nciphers
; j
++) {
3460 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3461 sccipher_tobe
= c
->list
[j
];
3466 if (sccipher_tobe
) {
3468 askcipher(sccipher_tobe
->name
, 2);
3472 if (!sccipher_tobe
) {
3473 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3477 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3478 for (i
= 0; i
< nmacs
; i
++) {
3479 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3480 csmac_tobe
= maclist
[i
];
3484 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3485 for (i
= 0; i
< nmacs
; i
++) {
3486 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3487 scmac_tobe
= maclist
[i
];
3491 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3492 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3493 const struct ssh_compress
*c
=
3494 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3495 if (in_commasep_string(c
->name
, str
, len
)) {
3500 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3501 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3502 const struct ssh_compress
*c
=
3503 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3504 if (in_commasep_string(c
->name
, str
, len
)) {
3511 * Work out the number of bits of key we will need from the key
3512 * exchange. We start with the maximum key length of either
3518 csbits
= cscipher_tobe
->keylen
;
3519 scbits
= sccipher_tobe
->keylen
;
3520 nbits
= (csbits
> scbits ? csbits
: scbits
);
3522 /* The keys only have 160-bit entropy, since they're based on
3523 * a SHA-1 hash. So cap the key size at 160 bits. */
3528 * If we're doing Diffie-Hellman group exchange, start by
3529 * requesting a group.
3531 if (kex
== &ssh_diffiehellman_gex
) {
3532 logevent("Doing Diffie-Hellman group exchange");
3533 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3535 * Work out how big a DH group we will need to allow that
3538 pbits
= 512 << ((nbits
- 1) / 64);
3539 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3540 ssh2_pkt_adduint32(pbits
);
3544 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3545 bombout(("expected key exchange group packet from server"));
3548 p
= ssh2_pkt_getmp();
3549 g
= ssh2_pkt_getmp();
3550 dh_setup_group(p
, g
);
3551 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3552 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3554 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3556 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3557 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3560 logevent("Doing Diffie-Hellman key exchange");
3562 * Now generate and send e for Diffie-Hellman.
3564 e
= dh_create_e(nbits
* 2);
3565 ssh2_pkt_init(kex_init_value
);
3570 if (pktin
.type
!= kex_reply_value
) {
3571 bombout(("expected key exchange reply packet from server"));
3574 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3575 f
= ssh2_pkt_getmp();
3576 ssh2_pkt_getstring(&sigdata
, &siglen
);
3580 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3581 if (kex
== &ssh_diffiehellman_gex
) {
3582 sha_uint32(&exhash
, pbits
);
3583 sha_mpint(&exhash
, p
);
3584 sha_mpint(&exhash
, g
);
3586 sha_mpint(&exhash
, e
);
3587 sha_mpint(&exhash
, f
);
3588 sha_mpint(&exhash
, K
);
3589 SHA_Final(&exhash
, exchange_hash
);
3594 debug(("Exchange hash is:\n"));
3595 dmemdump(exchange_hash
, 20);
3598 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3600 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3601 bombout(("Server's host key did not match the signature supplied"));
3606 * Authenticate remote host: verify host key. (We've already
3607 * checked the signature of the exchange hash.)
3609 keystr
= hostkey
->fmtkey(hkey
);
3610 fingerprint
= hostkey
->fingerprint(hkey
);
3611 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3612 keystr
, fingerprint
);
3613 if (first_kex
) { /* don't bother logging this in rekeys */
3614 logevent("Host key fingerprint is:");
3615 logevent(fingerprint
);
3619 hostkey
->freekey(hkey
);
3622 * Send SSH2_MSG_NEWKEYS.
3624 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3628 * Expect SSH2_MSG_NEWKEYS from server.
3631 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3632 bombout(("expected new-keys packet from server"));
3637 * Create and initialise session keys.
3639 cscipher
= cscipher_tobe
;
3640 sccipher
= sccipher_tobe
;
3643 cscomp
= cscomp_tobe
;
3644 sccomp
= sccomp_tobe
;
3645 cscomp
->compress_init();
3646 sccomp
->decompress_init();
3648 * Set IVs after keys. Here we use the exchange hash from the
3649 * _first_ key exchange.
3652 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3653 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3654 cscipher
->setcskey(keyspace
);
3655 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3656 sccipher
->setsckey(keyspace
);
3657 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3658 cscipher
->setcsiv(keyspace
);
3659 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3660 sccipher
->setsciv(keyspace
);
3661 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3662 csmac
->setcskey(keyspace
);
3663 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3664 scmac
->setsckey(keyspace
);
3667 * If this is the first key exchange phase, we must pass the
3668 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3669 * wants to see it but because it will need time to initialise
3670 * itself before it sees an actual packet. In subsequent key
3671 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3672 * it would only confuse the layer above.
3680 * Now we're encrypting. Begin returning 1 to the protocol main
3681 * function so that other things can run on top of the
3682 * transport. If we ever see a KEXINIT, we must go back to the
3685 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3688 logevent("Server initiated key re-exchange");
3689 goto begin_key_exchange
;
3695 * Add data to an SSH2 channel output buffer.
3697 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3700 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3704 * Attempt to send data on an SSH2 channel.
3706 static int ssh2_try_send(struct ssh_channel
*c
)
3708 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3711 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3712 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3713 len
= c
->v
.v2
.remwindow
;
3714 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3715 len
= c
->v
.v2
.remmaxpkt
;
3716 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3717 ssh2_pkt_adduint32(c
->remoteid
);
3718 ssh2_pkt_addstring_start();
3719 ssh2_pkt_addstring_data(data
, len
);
3721 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3722 c
->v
.v2
.remwindow
-= len
;
3726 * After having sent as much data as we can, return the amount
3729 return bufchain_size(&c
->v
.v2
.outbuffer
);
3733 * Potentially enlarge the window on an SSH2 channel.
3735 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3738 * Never send WINDOW_ADJUST for a channel that the remote side
3739 * already thinks it's closed; there's no point, since it won't
3740 * be sending any more data anyway.
3745 if (newwin
> c
->v
.v2
.locwindow
) {
3746 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3747 ssh2_pkt_adduint32(c
->remoteid
);
3748 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3750 c
->v
.v2
.locwindow
= newwin
;
3755 * Handle the SSH2 userauth and connection layers.
3757 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3760 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3762 AUTH_KEYBOARD_INTERACTIVE
3766 AUTH_TYPE_PUBLICKEY
,
3767 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3768 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3770 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3771 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3773 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3774 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3775 static int kbd_inter_running
;
3776 static int we_are_in
;
3777 static int num_prompts
, echo
;
3778 static char username
[100];
3779 static char pwprompt
[200];
3780 static char password
[100];
3781 static void *publickey_blob
;
3782 static int publickey_bloblen
;
3787 * Request userauth protocol, and await a response to it.
3789 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3790 ssh2_pkt_addstring("ssh-userauth");
3792 crWaitUntilV(ispkt
);
3793 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3794 bombout(("Server refused user authentication protocol"));
3799 * We repeat this whole loop, including the username prompt,
3800 * until we manage a successful authentication. If the user
3801 * types the wrong _password_, they are sent back to the
3802 * beginning to try another username. (If they specify a
3803 * username in the config, they are never asked, even if they
3804 * do give a wrong password.)
3806 * I think this best serves the needs of
3808 * - the people who have no configuration, no keys, and just
3809 * want to try repeated (username,password) pairs until they
3810 * type both correctly
3812 * - people who have keys and configuration but occasionally
3813 * need to fall back to passwords
3815 * - people with a key held in Pageant, who might not have
3816 * logged in to a particular machine before; so they want to
3817 * type a username, and then _either_ their key will be
3818 * accepted, _or_ they will type a password. If they mistype
3819 * the username they will want to be able to get back and
3831 if (*username
&& !cfg
.change_username
) {
3833 * We got a username last time round this loop, and
3834 * with change_username turned off we don't try to get
3837 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
3839 if (!ssh_get_line("login as: ",
3840 username
, sizeof(username
), FALSE
)) {
3842 * get_line failed to get a username.
3845 logevent("No username provided. Abandoning session.");
3846 ssh_state
= SSH_STATE_CLOSED
;
3850 c_write_str("login as: ");
3853 crWaitUntilV(!ispkt
);
3855 switch (c
= *in
++) {
3864 c_write_str("\b \b");
3871 c_write_str("\b \b");
3881 if (((c
>= ' ' && c
<= '~') ||
3882 ((unsigned char) c
>= 160))
3883 && pos
< sizeof(username
)-1) {
3884 username
[pos
++] = c
;
3891 c_write_str("\r\n");
3892 username
[strcspn(username
, "\n\r")] = '\0';
3895 strncpy(username
, cfg
.username
, 99);
3896 username
[99] = '\0';
3897 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3898 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3904 * Send an authentication request using method "none": (a)
3905 * just in case it succeeds, and (b) so that we know what
3906 * authentication methods we can usefully try next.
3908 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
3910 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3911 ssh2_pkt_addstring(username
);
3912 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3913 ssh2_pkt_addstring("none"); /* method */
3915 type
= AUTH_TYPE_NONE
;
3919 tried_pubkey_config
= FALSE
;
3920 tried_agent
= FALSE
;
3921 tried_keyb_inter
= FALSE
;
3922 kbd_inter_running
= FALSE
;
3923 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
3925 publickey_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
3926 &publickey_bloblen
);
3928 publickey_blob
= NULL
;
3932 * Wait for the result of the last authentication request.
3935 crWaitUntilV(ispkt
);
3936 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
3940 * Don't show the banner if we're operating in
3941 * non-verbose non-interactive mode. (It's probably
3942 * a script, which means nobody will read the
3943 * banner _anyway_, and moreover the printing of
3944 * the banner will screw up processing on the
3945 * output of (say) plink.)
3947 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
3948 ssh2_pkt_getstring(&banner
, &size
);
3950 c_write_untrusted(banner
, size
);
3952 crWaitUntilV(ispkt
);
3954 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
3955 logevent("Access granted");
3960 if (kbd_inter_running
&&
3961 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
3963 * This is a further prompt in keyboard-interactive
3964 * authentication. Do nothing.
3966 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
3967 bombout(("Strange packet received during authentication: type %d",
3975 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3976 * we can look at the string in it and know what we can
3977 * helpfully try next.
3979 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
3982 ssh2_pkt_getstring(&methods
, &methlen
);
3983 kbd_inter_running
= FALSE
;
3984 if (!ssh2_pkt_getbool()) {
3986 * We have received an unequivocal Access
3987 * Denied. This can translate to a variety of
3990 * - if we'd just tried "none" authentication,
3991 * it's not worth printing anything at all
3993 * - if we'd just tried a public key _offer_,
3994 * the message should be "Server refused our
3995 * key" (or no message at all if the key
3996 * came from Pageant)
3998 * - if we'd just tried anything else, the
3999 * message really should be "Access denied".
4001 * Additionally, if we'd just tried password
4002 * authentication, we should break out of this
4003 * whole loop so as to go back to the username
4006 if (type
== AUTH_TYPE_NONE
) {
4008 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4009 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4010 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4011 c_write_str("Server refused our key\r\n");
4012 logevent("Server refused public key");
4013 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4014 /* server declined keyboard-interactive; ignore */
4016 c_write_str("Access denied\r\n");
4017 logevent("Access denied");
4018 if (type
== AUTH_TYPE_PASSWORD
) {
4024 c_write_str("Further authentication required\r\n");
4025 logevent("Further authentication required");
4029 in_commasep_string("publickey", methods
, methlen
);
4031 in_commasep_string("password", methods
, methlen
);
4032 can_keyb_inter
= cfg
.try_ki_auth
&&
4033 in_commasep_string("keyboard-interactive", methods
, methlen
);
4037 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4039 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
4041 * Attempt public-key authentication using Pageant.
4043 static unsigned char request
[5], *response
, *p
;
4044 static int responselen
;
4045 static int i
, nkeys
;
4046 static int authed
= FALSE
;
4049 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4053 logevent("Pageant is running. Requesting keys.");
4055 /* Request the keys held by the agent. */
4056 PUT_32BIT(request
, 1);
4057 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4058 agent_query(request
, 5, &r
, &responselen
);
4059 response
= (unsigned char *) r
;
4060 if (response
&& responselen
>= 5 &&
4061 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4063 nkeys
= GET_32BIT(p
);
4067 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
4070 for (i
= 0; i
< nkeys
; i
++) {
4071 static char *pkblob
, *alg
, *commentp
;
4072 static int pklen
, alglen
, commentlen
;
4073 static int siglen
, retlen
, len
;
4074 static char *q
, *agentreq
, *ret
;
4079 sprintf(buf
, "Trying Pageant key #%d", i
);
4082 pklen
= GET_32BIT(p
);
4084 if (publickey_blob
&&
4085 pklen
== publickey_bloblen
&&
4086 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
4087 logevent("This key matches configured key file");
4088 tried_pubkey_config
= 1;
4092 alglen
= GET_32BIT(pkblob
);
4094 commentlen
= GET_32BIT(p
);
4098 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4099 ssh2_pkt_addstring(username
);
4100 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4101 ssh2_pkt_addstring("publickey"); /* method */
4102 ssh2_pkt_addbool(FALSE
); /* no signature included */
4103 ssh2_pkt_addstring_start();
4104 ssh2_pkt_addstring_data(alg
, alglen
);
4105 ssh2_pkt_addstring_start();
4106 ssh2_pkt_addstring_data(pkblob
, pklen
);
4109 crWaitUntilV(ispkt
);
4110 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4111 logevent("Key refused");
4115 if (flags
& FLAG_VERBOSE
) {
4117 ("Authenticating with public key \"");
4118 c_write(commentp
, commentlen
);
4119 c_write_str("\" from agent\r\n");
4123 * Server is willing to accept the key.
4124 * Construct a SIGN_REQUEST.
4126 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4127 ssh2_pkt_addstring(username
);
4128 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4129 ssh2_pkt_addstring("publickey"); /* method */
4130 ssh2_pkt_addbool(TRUE
);
4131 ssh2_pkt_addstring_start();
4132 ssh2_pkt_addstring_data(alg
, alglen
);
4133 ssh2_pkt_addstring_start();
4134 ssh2_pkt_addstring_data(pkblob
, pklen
);
4136 siglen
= pktout
.length
- 5 + 4 + 20;
4137 len
= 1; /* message type */
4138 len
+= 4 + pklen
; /* key blob */
4139 len
+= 4 + siglen
; /* data to sign */
4140 len
+= 4; /* flags */
4141 agentreq
= smalloc(4 + len
);
4142 PUT_32BIT(agentreq
, len
);
4144 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4145 PUT_32BIT(q
, pklen
);
4147 memcpy(q
, pkblob
, pklen
);
4149 PUT_32BIT(q
, siglen
);
4151 /* Now the data to be signed... */
4154 memcpy(q
, ssh2_session_id
, 20);
4156 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4157 q
+= pktout
.length
- 5;
4158 /* And finally the (zero) flags word. */
4160 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4164 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4165 logevent("Sending Pageant's response");
4166 ssh2_pkt_addstring_start();
4167 ssh2_pkt_addstring_data(ret
+ 9,
4175 ("Pageant failed to answer challenge");
4185 if (!method
&& can_pubkey
&& *cfg
.keyfile
4186 && !tried_pubkey_config
) {
4187 unsigned char *pub_blob
;
4188 char *algorithm
, *comment
;
4191 tried_pubkey_config
= TRUE
;
4193 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4196 * Try the public key supplied in the configuration.
4198 * First, offer the public blob to see if the server is
4199 * willing to accept it.
4201 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4204 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4205 ssh2_pkt_addstring(username
);
4206 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4207 ssh2_pkt_addstring("publickey"); /* method */
4208 ssh2_pkt_addbool(FALSE
); /* no signature included */
4209 ssh2_pkt_addstring(algorithm
);
4210 ssh2_pkt_addstring_start();
4211 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4213 logevent("Offered public key"); /* FIXME */
4215 crWaitUntilV(ispkt
);
4216 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4218 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4219 continue; /* key refused; give up on it */
4222 logevent("Offer of public key accepted");
4224 * Actually attempt a serious authentication using
4227 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4229 "Passphrase for key \"%.100s\": ",
4235 c_write_str("Authenticating with public key \"");
4236 c_write_str(comment
);
4237 c_write_str("\"\r\n");
4238 method
= AUTH_PUBLICKEY_FILE
;
4242 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4243 method
= AUTH_KEYBOARD_INTERACTIVE
;
4244 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4245 tried_keyb_inter
= TRUE
;
4247 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4249 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4250 ssh2_pkt_addstring(username
);
4251 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4252 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4253 ssh2_pkt_addstring(""); /* lang */
4254 ssh2_pkt_addstring("");
4257 crWaitUntilV(ispkt
);
4258 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4259 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4261 logevent("Keyboard-interactive authentication refused");
4262 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4266 kbd_inter_running
= TRUE
;
4269 if (kbd_inter_running
) {
4270 method
= AUTH_KEYBOARD_INTERACTIVE
;
4271 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4272 tried_keyb_inter
= TRUE
;
4274 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4276 /* We've got packet with that "interactive" info
4277 dump banners, and set its prompt as ours */
4279 char *name
, *inst
, *lang
, *prompt
;
4280 int name_len
, inst_len
, lang_len
, prompt_len
;
4281 ssh2_pkt_getstring(&name
, &name_len
);
4282 ssh2_pkt_getstring(&inst
, &inst_len
);
4283 ssh2_pkt_getstring(&lang
, &lang_len
);
4285 c_write_untrusted(name
, name_len
);
4287 c_write_untrusted(inst
, inst_len
);
4288 num_prompts
= ssh2_pkt_getuint32();
4290 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4291 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4292 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4293 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4296 echo
= ssh2_pkt_getbool();
4300 if (!method
&& can_passwd
) {
4301 method
= AUTH_PASSWORD
;
4302 ssh_pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4303 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4310 if (!ssh_get_line(pwprompt
, password
,
4311 sizeof(password
), TRUE
)) {
4313 * get_line failed to get a password (for
4314 * example because one was supplied on the
4315 * command line which has already failed to
4318 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4319 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4321 ("No more passwords available to try");
4322 ssh2_pkt_addstring("en"); /* language tag */
4324 connection_fatal("Unable to authenticate");
4325 ssh_state
= SSH_STATE_CLOSED
;
4332 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4337 crWaitUntilV(!ispkt
);
4339 switch (c
= *in
++) {
4360 if (pos
< sizeof(password
)-1)
4361 password
[pos
++] = c
;
4365 c_write_str("\r\n");
4369 if (method
== AUTH_PUBLICKEY_FILE
) {
4371 * We have our passphrase. Now try the actual authentication.
4373 struct ssh2_userkey
*key
;
4375 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4376 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4377 if (key
== SSH2_WRONG_PASSPHRASE
) {
4378 c_write_str("Wrong passphrase\r\n");
4379 tried_pubkey_config
= FALSE
;
4381 c_write_str("Unable to load private key\r\n");
4382 tried_pubkey_config
= TRUE
;
4384 /* Send a spurious AUTH_NONE to return to the top. */
4385 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4386 ssh2_pkt_addstring(username
);
4387 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4388 ssh2_pkt_addstring("none"); /* method */
4390 type
= AUTH_TYPE_NONE
;
4392 unsigned char *blob
, *sigdata
;
4393 int blob_len
, sigdata_len
;
4396 * We have loaded the private key and the server
4397 * has announced that it's willing to accept it.
4398 * Hallelujah. Generate a signature and send it.
4400 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4401 ssh2_pkt_addstring(username
);
4402 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4403 ssh2_pkt_addstring("publickey"); /* method */
4404 ssh2_pkt_addbool(TRUE
);
4405 ssh2_pkt_addstring(key
->alg
->name
);
4406 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4407 ssh2_pkt_addstring_start();
4408 ssh2_pkt_addstring_data(blob
, blob_len
);
4412 * The data to be signed is:
4416 * followed by everything so far placed in the
4419 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4420 sigdata
= smalloc(sigdata_len
);
4421 PUT_32BIT(sigdata
, 20);
4422 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4423 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4426 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4428 ssh2_pkt_addstring_start();
4429 ssh2_pkt_addstring_data(blob
, blob_len
);
4434 type
= AUTH_TYPE_PUBLICKEY
;
4436 } else if (method
== AUTH_PASSWORD
) {
4438 * We send the password packet lumped tightly together with
4439 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4440 * string long enough to make the total length of the two
4441 * packets constant. This should ensure that a passive
4442 * listener doing traffic analyis can't work out the length
4445 * For this to work, we need an assumption about the
4446 * maximum length of the password packet. I think 256 is
4447 * pretty conservative. Anyone using a password longer than
4448 * that probably doesn't have much to worry about from
4449 * people who find out how long their password is!
4451 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4452 ssh2_pkt_addstring(username
);
4453 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4454 ssh2_pkt_addstring("password");
4455 ssh2_pkt_addbool(FALSE
);
4456 ssh2_pkt_addstring(password
);
4459 * We'll include a string that's an exact multiple of the
4460 * cipher block size. If the cipher is NULL for some
4461 * reason, we don't do this trick at all because we gain
4467 stringlen
= (256 - deferred_len
);
4468 stringlen
+= cscipher
->blksize
- 1;
4469 stringlen
-= (stringlen
% cscipher
->blksize
);
4472 * Temporarily disable actual compression,
4473 * so we can guarantee to get this string
4474 * exactly the length we want it. The
4475 * compression-disabling routine should
4476 * return an integer indicating how many
4477 * bytes we should adjust our string length
4480 stringlen
-= cscomp
->disable_compression();
4482 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4483 ssh2_pkt_addstring_start();
4484 for (i
= 0; i
< stringlen
; i
++) {
4485 char c
= (char) random_byte();
4486 ssh2_pkt_addstring_data(&c
, 1);
4490 ssh_pkt_defersend();
4491 logevent("Sent password");
4492 type
= AUTH_TYPE_PASSWORD
;
4493 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4494 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4495 ssh2_pkt_adduint32(num_prompts
);
4496 ssh2_pkt_addstring(password
);
4497 memset(password
, 0, sizeof(password
));
4499 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4502 ("No supported authentication methods left to try!\r\n");
4504 ("No supported authentications offered. Disconnecting");
4505 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4506 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4508 ("No supported authentication methods available");
4509 ssh2_pkt_addstring("en"); /* language tag */
4511 ssh_state
= SSH_STATE_CLOSED
;
4515 } while (!we_are_in
);
4518 * Now we're authenticated for the connection protocol. The
4519 * connection protocol will automatically have started at this
4520 * point; there's no need to send SERVICE_REQUEST.
4524 * So now create a channel with a session in it.
4526 ssh_channels
= newtree234(ssh_channelcmp
);
4527 mainchan
= smalloc(sizeof(struct ssh_channel
));
4528 mainchan
->localid
= alloc_channel_id();
4529 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4530 ssh2_pkt_addstring("session");
4531 ssh2_pkt_adduint32(mainchan
->localid
);
4532 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4533 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4534 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4536 crWaitUntilV(ispkt
);
4537 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4538 bombout(("Server refused to open a session"));
4540 /* FIXME: error data comes back in FAILURE packet */
4542 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4543 bombout(("Server's channel confirmation cited wrong channel"));
4546 mainchan
->remoteid
= ssh2_pkt_getuint32();
4547 mainchan
->type
= CHAN_MAINSESSION
;
4548 mainchan
->closes
= 0;
4549 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4550 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4551 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4552 add234(ssh_channels
, mainchan
);
4553 logevent("Opened channel for session");
4556 * Potentially enable X11 forwarding.
4558 if (cfg
.x11_forward
) {
4559 char proto
[20], data
[64];
4560 logevent("Requesting X11 forwarding");
4561 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4562 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4563 ssh2_pkt_adduint32(mainchan
->remoteid
);
4564 ssh2_pkt_addstring("x11-req");
4565 ssh2_pkt_addbool(1); /* want reply */
4566 ssh2_pkt_addbool(0); /* many connections */
4567 ssh2_pkt_addstring(proto
);
4568 ssh2_pkt_addstring(data
);
4569 ssh2_pkt_adduint32(0); /* screen number */
4573 crWaitUntilV(ispkt
);
4574 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4575 unsigned i
= ssh2_pkt_getuint32();
4576 struct ssh_channel
*c
;
4577 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4579 continue; /* nonexistent channel */
4580 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4582 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4584 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4585 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4586 bombout(("Unexpected response to X11 forwarding request:"
4587 " packet type %d", pktin
.type
));
4590 logevent("X11 forwarding refused");
4592 logevent("X11 forwarding enabled");
4593 ssh_X11_fwd_enabled
= TRUE
;
4598 * Enable port forwardings.
4601 static char *e
; /* preserve across crReturn */
4605 char sports
[256], dports
[256], host
[256];
4608 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4609 /* Add port forwardings. */
4614 while (*e
&& *e
!= '\t')
4620 while (*e
&& *e
!= ':')
4630 dport
= atoi(dports
);
4631 sport
= atoi(sports
);
4632 if (sport
&& dport
) {
4634 pfd_addforward(host
, dport
, sport
);
4635 sprintf(buf
, "Local port %d forwarding to %s:%d",
4636 sport
, host
, dport
);
4639 struct ssh_rportfwd
*pf
;
4640 pf
= smalloc(sizeof(*pf
));
4641 strcpy(pf
->dhost
, host
);
4644 if (add234(ssh_rportfwds
, pf
) != pf
) {
4646 "Duplicate remote port forwarding to %s:%d",
4651 sprintf(buf
, "Requesting remote port %d (forwarded to %s:%d)",
4652 sport
, host
, dport
);
4654 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4655 ssh2_pkt_addstring("tcpip-forward");
4656 ssh2_pkt_addbool(1);/* want reply */
4657 if (cfg
.rport_acceptall
)
4658 ssh2_pkt_addstring("0.0.0.0");
4660 ssh2_pkt_addstring("127.0.0.1");
4661 ssh2_pkt_adduint32(sport
);
4665 crWaitUntilV(ispkt
);
4666 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4667 unsigned i
= ssh2_pkt_getuint32();
4668 struct ssh_channel
*c
;
4669 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4671 continue;/* nonexistent channel */
4672 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4674 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4676 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4677 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4678 bombout(("Unexpected response to port "
4679 "forwarding request: packet type %d",
4683 logevent("Server refused this port forwarding");
4685 logevent("Remote port forwarding enabled");
4694 * Potentially enable agent forwarding.
4696 if (cfg
.agentfwd
&& agent_exists()) {
4697 logevent("Requesting OpenSSH-style agent forwarding");
4698 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4699 ssh2_pkt_adduint32(mainchan
->remoteid
);
4700 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4701 ssh2_pkt_addbool(1); /* want reply */
4705 crWaitUntilV(ispkt
);
4706 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4707 unsigned i
= ssh2_pkt_getuint32();
4708 struct ssh_channel
*c
;
4709 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4711 continue; /* nonexistent channel */
4712 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4714 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4716 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4717 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4718 bombout(("Unexpected response to agent forwarding request:"
4719 " packet type %d", pktin
.type
));
4722 logevent("Agent forwarding refused");
4724 logevent("Agent forwarding enabled");
4725 ssh_agentfwd_enabled
= TRUE
;
4730 * Now allocate a pty for the session.
4733 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4734 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4735 ssh2_pkt_addstring("pty-req");
4736 ssh2_pkt_addbool(1); /* want reply */
4737 ssh2_pkt_addstring(cfg
.termtype
);
4738 ssh2_pkt_adduint32(cols
);
4739 ssh2_pkt_adduint32(rows
);
4740 ssh2_pkt_adduint32(0); /* pixel width */
4741 ssh2_pkt_adduint32(0); /* pixel height */
4742 ssh2_pkt_addstring_start();
4743 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4745 ssh_state
= SSH_STATE_INTERMED
;
4748 crWaitUntilV(ispkt
);
4749 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4750 unsigned i
= ssh2_pkt_getuint32();
4751 struct ssh_channel
*c
;
4752 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4754 continue; /* nonexistent channel */
4755 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4757 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4759 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4760 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4761 bombout(("Unexpected response to pty request:"
4762 " packet type %d", pktin
.type
));
4765 c_write_str("Server refused to allocate pty\r\n");
4766 ssh_editing
= ssh_echoing
= 1;
4768 logevent("Allocated pty");
4771 ssh_editing
= ssh_echoing
= 1;
4775 * Start a shell or a remote command. We may have to attempt
4776 * this twice if the config data has provided a second choice
4783 if (ssh_fallback_cmd
) {
4784 subsys
= cfg
.ssh_subsys2
;
4785 cmd
= cfg
.remote_cmd_ptr2
;
4787 subsys
= cfg
.ssh_subsys
;
4788 cmd
= cfg
.remote_cmd_ptr
;
4791 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4792 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4794 ssh2_pkt_addstring("subsystem");
4795 ssh2_pkt_addbool(1); /* want reply */
4796 ssh2_pkt_addstring(cmd
);
4798 ssh2_pkt_addstring("exec");
4799 ssh2_pkt_addbool(1); /* want reply */
4800 ssh2_pkt_addstring(cmd
);
4802 ssh2_pkt_addstring("shell");
4803 ssh2_pkt_addbool(1); /* want reply */
4807 crWaitUntilV(ispkt
);
4808 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4809 unsigned i
= ssh2_pkt_getuint32();
4810 struct ssh_channel
*c
;
4811 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4813 continue; /* nonexistent channel */
4814 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4816 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4817 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4818 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4819 bombout(("Unexpected response to shell/command request:"
4820 " packet type %d", pktin
.type
));
4824 * We failed to start the command. If this is the
4825 * fallback command, we really are finished; if it's
4826 * not, and if the fallback command exists, try falling
4827 * back to it before complaining.
4829 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
4830 logevent("Primary command failed; attempting fallback");
4831 ssh_fallback_cmd
= TRUE
;
4834 bombout(("Server refused to start a shell/command"));
4837 logevent("Started a shell/command");
4842 ssh_state
= SSH_STATE_SESSION
;
4846 ssh_special(TS_EOF
);
4851 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
4854 static int try_send
;
4858 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
4859 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
4862 unsigned i
= ssh2_pkt_getuint32();
4863 struct ssh_channel
*c
;
4864 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4866 continue; /* nonexistent channel */
4867 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
4868 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
4869 continue; /* extended but not stderr */
4870 ssh2_pkt_getstring(&data
, &length
);
4873 c
->v
.v2
.locwindow
-= length
;
4875 case CHAN_MAINSESSION
:
4877 from_backend(pktin
.type
==
4878 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
4882 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
4885 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
4888 while (length
> 0) {
4889 if (c
->u
.a
.lensofar
< 4) {
4890 int l
= min(4 - c
->u
.a
.lensofar
, length
);
4891 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
4895 c
->u
.a
.lensofar
+= l
;
4897 if (c
->u
.a
.lensofar
== 4) {
4899 4 + GET_32BIT(c
->u
.a
.msglen
);
4900 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
4901 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
4903 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
4905 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
4907 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
4911 c
->u
.a
.lensofar
+= l
;
4913 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
4914 void *reply
, *sentreply
;
4916 agent_query(c
->u
.a
.message
,
4917 c
->u
.a
.totallen
, &reply
,
4922 /* Fake SSH_AGENT_FAILURE. */
4923 sentreply
= "\0\0\0\1\5";
4926 ssh2_add_channel_data(c
, sentreply
,
4931 sfree(c
->u
.a
.message
);
4932 c
->u
.a
.lensofar
= 0;
4939 * If we are not buffering too much data,
4940 * enlarge the window again at the remote side.
4942 if (bufsize
< OUR_V2_WINSIZE
)
4943 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
4945 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
4946 ssh_state
= SSH_STATE_CLOSED
;
4947 logevent("Received disconnect message");
4949 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
4950 unsigned i
= ssh2_pkt_getuint32();
4951 struct ssh_channel
*c
;
4953 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4955 continue; /* nonexistent channel */
4957 if (c
->type
== CHAN_X11
) {
4959 * Remote EOF on an X11 channel means we should
4960 * wrap up and close the channel ourselves.
4962 x11_close(c
->u
.x11
.s
);
4964 } else if (c
->type
== CHAN_AGENT
) {
4966 } else if (c
->type
== CHAN_SOCKDATA
) {
4967 pfd_close(c
->u
.pfd
.s
);
4970 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
4971 unsigned i
= ssh2_pkt_getuint32();
4972 struct ssh_channel
*c
;
4974 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4976 continue; /* nonexistent channel */
4977 /* Do pre-close processing on the channel. */
4979 case CHAN_MAINSESSION
:
4980 break; /* nothing to see here, move along */
4982 if (c
->u
.x11
.s
!= NULL
)
4983 x11_close(c
->u
.x11
.s
);
4990 if (c
->u
.pfd
.s
!= NULL
)
4991 pfd_close(c
->u
.pfd
.s
);
4995 if (c
->closes
== 0) {
4996 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4997 ssh2_pkt_adduint32(c
->remoteid
);
5000 del234(ssh_channels
, c
);
5001 bufchain_clear(&c
->v
.v2
.outbuffer
);
5005 * See if that was the last channel left open.
5007 if (count234(ssh_channels
) == 0) {
5010 * We used to send SSH_MSG_DISCONNECT here,
5011 * because I'd believed that _every_ conforming
5012 * SSH2 connection had to end with a disconnect
5013 * being sent by at least one side; apparently
5014 * I was wrong and it's perfectly OK to
5015 * unceremoniously slam the connection shut
5016 * when you're done, and indeed OpenSSH feels
5017 * this is more polite than sending a
5018 * DISCONNECT. So now we don't.
5020 logevent("All channels closed. Disconnecting");
5021 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5022 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5023 ssh2_pkt_addstring("All open channels closed");
5024 ssh2_pkt_addstring("en"); /* language tag */
5027 ssh_state
= SSH_STATE_CLOSED
;
5030 continue; /* remote sends close; ignore (FIXME) */
5031 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5032 unsigned i
= ssh2_pkt_getuint32();
5033 struct ssh_channel
*c
;
5034 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5036 continue; /* nonexistent channel */
5037 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5039 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5040 unsigned i
= ssh2_pkt_getuint32();
5041 struct ssh_channel
*c
;
5042 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5044 continue; /* nonexistent channel */
5045 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5046 continue; /* dunno why they're confirming this */
5047 c
->remoteid
= ssh2_pkt_getuint32();
5048 c
->type
= CHAN_SOCKDATA
;
5049 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
5050 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
5051 bufchain_init(&c
->v
.v2
.outbuffer
);
5053 pfd_confirm(c
->u
.pfd
.s
);
5056 * We have a pending close on this channel,
5057 * which we decided on before the server acked
5058 * the channel open. So now we know the
5059 * remoteid, we can close it again.
5061 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5062 ssh2_pkt_adduint32(c
->remoteid
);
5065 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5066 unsigned i
= ssh2_pkt_getuint32();
5067 struct ssh_channel
*c
;
5068 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5070 continue; /* nonexistent channel */
5071 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5072 continue; /* dunno why they're failing this */
5074 logevent("Forwarded connection refused by server");
5076 pfd_close(c
->u
.pfd
.s
);
5078 del234(ssh_channels
, c
);
5080 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5083 int typelen
, want_reply
;
5084 struct ssh_channel
*c
;
5086 localid
= ssh2_pkt_getuint32();
5087 ssh2_pkt_getstring(&type
, &typelen
);
5088 want_reply
= ssh2_pkt_getbool();
5091 * First, check that the channel exists. Otherwise,
5092 * we can instantly disconnect with a rude message.
5094 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
5097 sprintf(buf
, "Received channel request for nonexistent"
5098 " channel %d", localid
);
5100 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5101 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5102 ssh2_pkt_addstring(buf
);
5103 ssh2_pkt_addstring("en"); /* language tag */
5105 connection_fatal(buf
);
5106 ssh_state
= SSH_STATE_CLOSED
;
5111 * Having got the channel number, we now look at
5112 * the request type string to see if it's something
5115 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5117 /* We recognise "exit-status" on the primary channel. */
5119 ssh_exitcode
= ssh2_pkt_getuint32();
5120 sprintf(buf
, "Server sent command exit status %d",
5124 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS
);
5125 ssh2_pkt_adduint32(c
->remoteid
);
5130 * This is a channel request we don't know
5131 * about, so we now either ignore the request
5132 * or respond with CHANNEL_FAILURE, depending
5136 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
5137 ssh2_pkt_adduint32(c
->remoteid
);
5141 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5145 struct ssh_channel
*c
;
5146 unsigned remid
, winsize
, pktsize
;
5147 ssh2_pkt_getstring(&type
, &typelen
);
5148 c
= smalloc(sizeof(struct ssh_channel
));
5150 remid
= ssh2_pkt_getuint32();
5151 winsize
= ssh2_pkt_getuint32();
5152 pktsize
= ssh2_pkt_getuint32();
5154 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5155 if (!ssh_X11_fwd_enabled
)
5156 error
= "X11 forwarding is not enabled";
5157 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
5159 error
= "Unable to open an X11 connection";
5163 } else if (typelen
== 15 &&
5164 !memcmp(type
, "forwarded-tcpip", 15)) {
5165 struct ssh_rportfwd pf
, *realpf
;
5168 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
5169 pf
.sport
= ssh2_pkt_getuint32();
5170 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
5171 if (realpf
== NULL
) {
5172 error
= "Remote port is not recognised";
5174 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5177 sprintf(buf
, "Received remote port open request for %s:%d",
5178 realpf
->dhost
, realpf
->dport
);
5181 sprintf(buf
, "Port open failed: %s", e
);
5183 error
= "Port open failed";
5185 logevent("Forwarded port opened successfully");
5186 c
->type
= CHAN_SOCKDATA
;
5189 } else if (typelen
== 22 &&
5190 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5191 if (!ssh_agentfwd_enabled
)
5192 error
= "Agent forwarding is not enabled";
5194 c
->type
= CHAN_AGENT
; /* identify channel type */
5195 c
->u
.a
.lensofar
= 0;
5198 error
= "Unsupported channel type requested";
5201 c
->remoteid
= remid
;
5203 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5204 ssh2_pkt_adduint32(c
->remoteid
);
5205 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5206 ssh2_pkt_addstring(error
);
5207 ssh2_pkt_addstring("en"); /* language tag */
5211 c
->localid
= alloc_channel_id();
5213 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5214 c
->v
.v2
.remwindow
= winsize
;
5215 c
->v
.v2
.remmaxpkt
= pktsize
;
5216 bufchain_init(&c
->v
.v2
.outbuffer
);
5217 add234(ssh_channels
, c
);
5218 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5219 ssh2_pkt_adduint32(c
->remoteid
);
5220 ssh2_pkt_adduint32(c
->localid
);
5221 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5222 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5226 bombout(("Strange packet received: type %d", pktin
.type
));
5231 * We have spare data. Add it to the channel buffer.
5233 ssh2_add_channel_data(mainchan
, in
, inlen
);
5238 struct ssh_channel
*c
;
5240 * Try to send data on all channels if we can.
5242 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5243 int bufsize
= ssh2_try_send(c
);
5246 case CHAN_MAINSESSION
:
5247 /* stdin need not receive an unthrottle
5248 * notification since it will be polled */
5251 x11_unthrottle(c
->u
.x11
.s
);
5254 /* agent sockets are request/response and need no
5255 * buffer management */
5258 pfd_unthrottle(c
->u
.pfd
.s
);
5270 * Handle the top-level SSH2 protocol.
5272 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5274 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5276 do_ssh2_authconn(in
, inlen
, ispkt
);
5280 * Called to set up the connection.
5282 * Returns an error message, or NULL on success.
5284 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5289 if (crypto_startup() == 0)
5290 return "Microsoft high encryption pack not installed!";
5296 ssh1_throttle_count
= 0;
5297 ssh_overall_bufsize
= 0;
5298 ssh_fallback_cmd
= 0;
5300 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5308 * Called to send data down the Telnet connection.
5310 static int ssh_send(char *buf
, int len
)
5312 if (s
== NULL
|| ssh_protocol
== NULL
)
5315 ssh_protocol(buf
, len
, 0);
5317 return ssh_sendbuffer();
5321 * Called to query the current amount of buffered stdin data.
5323 static int ssh_sendbuffer(void)
5327 if (s
== NULL
|| ssh_protocol
== NULL
)
5331 * If the SSH socket itself has backed up, add the total backup
5332 * size on that to any individual buffer on the stdin channel.
5335 if (ssh_throttled_all
)
5336 override_value
= ssh_overall_bufsize
;
5338 if (ssh_version
== 1) {
5339 return override_value
;
5340 } else if (ssh_version
== 2) {
5341 if (!mainchan
|| mainchan
->closes
> 0)
5342 return override_value
;
5344 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5351 * Called to set the size of the window from SSH's POV.
5353 static void ssh_size(void)
5355 switch (ssh_state
) {
5356 case SSH_STATE_BEFORE_SIZE
:
5357 case SSH_STATE_PREPACKET
:
5358 case SSH_STATE_CLOSED
:
5359 break; /* do nothing */
5360 case SSH_STATE_INTERMED
:
5361 size_needed
= TRUE
; /* buffer for later */
5363 case SSH_STATE_SESSION
:
5365 if (ssh_version
== 1) {
5366 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5367 PKT_INT
, rows
, PKT_INT
, cols
,
5368 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5370 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5371 ssh2_pkt_adduint32(mainchan
->remoteid
);
5372 ssh2_pkt_addstring("window-change");
5373 ssh2_pkt_addbool(0);
5374 ssh2_pkt_adduint32(cols
);
5375 ssh2_pkt_adduint32(rows
);
5376 ssh2_pkt_adduint32(0);
5377 ssh2_pkt_adduint32(0);
5386 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5387 * can send an EOF and collect resulting output (e.g. `plink
5390 static void ssh_special(Telnet_Special code
)
5392 if (code
== TS_EOF
) {
5393 if (ssh_state
!= SSH_STATE_SESSION
) {
5395 * Buffer the EOF in case we are pre-SESSION, so we can
5396 * send it as soon as we reach SESSION.
5402 if (ssh_version
== 1) {
5403 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5405 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5406 ssh2_pkt_adduint32(mainchan
->remoteid
);
5409 logevent("Sent EOF message");
5410 } else if (code
== TS_PING
) {
5411 if (ssh_state
== SSH_STATE_CLOSED
5412 || ssh_state
== SSH_STATE_PREPACKET
) return;
5413 if (ssh_version
== 1) {
5414 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5416 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5417 ssh2_pkt_addstring_start();
5425 void *new_sock_channel(Socket s
)
5427 struct ssh_channel
*c
;
5428 c
= smalloc(sizeof(struct ssh_channel
));
5431 c
->remoteid
= -1; /* to be set when open confirmed */
5432 c
->localid
= alloc_channel_id();
5434 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5436 add234(ssh_channels
, c
);
5442 * This is called when stdout/stderr (the entity to which
5443 * from_backend sends data) manages to clear some backlog.
5445 void ssh_unthrottle(int bufsize
)
5447 if (ssh_version
== 1) {
5448 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5449 ssh1_stdout_throttling
= 0;
5453 if (mainchan
&& mainchan
->closes
== 0)
5454 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5458 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5460 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5463 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5466 if (ssh_version
== 1) {
5467 send_packet(SSH1_MSG_PORT_OPEN
,
5468 PKT_INT
, c
->localid
,
5471 //PKT_STR, <org:orgport>,
5474 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5475 ssh2_pkt_addstring("direct-tcpip");
5476 ssh2_pkt_adduint32(c
->localid
);
5477 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5478 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5479 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5480 ssh2_pkt_addstring(hostname
);
5481 ssh2_pkt_adduint32(port
);
5483 * We make up values for the originator data; partly it's
5484 * too much hassle to keep track, and partly I'm not
5485 * convinced the server should be told details like that
5486 * about my local network configuration.
5488 ssh2_pkt_addstring("client-side-connection");
5489 ssh2_pkt_adduint32(0);
5495 static Socket
ssh_socket(void)
5500 static int ssh_sendok(void)
5505 static int ssh_ldisc(int option
)
5507 if (option
== LD_ECHO
)
5509 if (option
== LD_EDIT
)
5514 static int ssh_return_exitcode(void)
5516 return ssh_exitcode
;
5519 Backend ssh_backend
= {
5526 ssh_return_exitcode
,