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
;
728 cipher
->decrypt(pktin
.data
, st
->biglen
);
730 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
731 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
732 if (st
->gotcrc
!= st
->realcrc
) {
733 bombout(("Incorrect CRC received on packet"));
737 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
739 if (ssh1_compressing
) {
740 unsigned char *decompblk
;
742 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
743 &decompblk
, &decomplen
);
745 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
746 pktin
.maxlen
= st
->pad
+ decomplen
;
747 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
748 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
750 fatalbox("Out of memory");
753 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
755 pktin
.length
= decomplen
- 1;
758 pktin
.type
= pktin
.body
[-1];
760 log_packet(PKT_INCOMING
, pktin
.type
, ssh1_pkt_type(pktin
.type
),
761 pktin
.body
, pktin
.length
);
763 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
764 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
765 pktin
.type
== SSH1_MSG_DEBUG
||
766 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
767 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
768 long strlen
= GET_32BIT(pktin
.body
);
769 if (strlen
+ 4 != pktin
.length
) {
770 bombout(("Received data packet with bogus string length"));
775 if (pktin
.type
== SSH1_MSG_DEBUG
) {
776 /* log debug message */
778 int strlen
= GET_32BIT(pktin
.body
);
779 strcpy(buf
, "Remote: ");
782 memcpy(buf
+ 8, pktin
.body
+ 4, strlen
);
783 buf
[8 + strlen
] = '\0';
786 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
791 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
792 /* log reason code in disconnect message */
794 unsigned msglen
= GET_32BIT(pktin
.body
);
796 strcpy(buf
, "Remote sent disconnect: ");
797 nowlen
= strlen(buf
);
798 if (msglen
> sizeof(buf
) - nowlen
- 1)
799 msglen
= sizeof(buf
) - nowlen
- 1;
800 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
801 buf
[nowlen
+ msglen
] = '\0';
803 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
810 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
812 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
820 st
->cipherblk
= sccipher
->blksize
;
823 if (st
->cipherblk
< 8)
826 if (pktin
.maxlen
< st
->cipherblk
) {
827 pktin
.maxlen
= st
->cipherblk
;
830 NULL ?
smalloc(st
->cipherblk
+
831 APIEXTRA
) : srealloc(pktin
.data
,
835 fatalbox("Out of memory");
839 * Acquire and decrypt the first block of the packet. This will
840 * contain the length and padding details.
842 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
843 while ((*datalen
) == 0)
844 crReturn(st
->cipherblk
- st
->i
);
845 pktin
.data
[st
->i
] = *(*data
)++;
850 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
853 * Now get the length and padding figures.
855 st
->len
= GET_32BIT(pktin
.data
);
856 st
->pad
= pktin
.data
[4];
859 * This enables us to deduce the payload length.
861 st
->payload
= st
->len
- st
->pad
- 1;
863 pktin
.length
= st
->payload
+ 5;
866 * So now we can work out the total packet length.
868 st
->packetlen
= st
->len
+ 4;
869 st
->maclen
= scmac ? scmac
->len
: 0;
872 * Adjust memory allocation if packet is too big.
874 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
875 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
878 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
883 fatalbox("Out of memory");
887 * Read and decrypt the remainder of the packet.
889 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
891 while ((*datalen
) == 0)
892 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
893 pktin
.data
[st
->i
] = *(*data
)++;
896 /* Decrypt everything _except_ the MAC. */
898 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
899 st
->packetlen
- st
->cipherblk
);
905 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
906 st
->incoming_sequence
)) {
907 bombout(("Incorrect MAC received on packet"));
910 st
->incoming_sequence
++; /* whether or not we MACed */
913 * Decompress packet payload.
916 unsigned char *newpayload
;
918 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
919 &newpayload
, &newlen
)) {
920 if (pktin
.maxlen
< newlen
+ 5) {
921 pktin
.maxlen
= newlen
+ 5;
924 NULL ?
smalloc(pktin
.maxlen
+
925 APIEXTRA
) : srealloc(pktin
.data
,
929 fatalbox("Out of memory");
931 pktin
.length
= 5 + newlen
;
932 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
938 pktin
.type
= pktin
.data
[5];
940 log_packet(PKT_INCOMING
, pktin
.type
, ssh2_pkt_type(pktin
.type
),
941 pktin
.data
+6, pktin
.length
-6);
943 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
944 goto next_packet
; /* FIXME: print DEBUG message */
946 if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
947 /* log reason code in disconnect message */
949 int reason
= GET_32BIT(pktin
.data
+ 6);
950 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
952 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
953 sprintf(buf
, "Received disconnect message (%s)",
954 ssh2_disconnect_reasons
[reason
]);
956 sprintf(buf
, "Received disconnect message (unknown type %d)",
960 strcpy(buf
, "Disconnection message text: ");
961 nowlen
= strlen(buf
);
962 if (msglen
> sizeof(buf
) - nowlen
- 1)
963 msglen
= sizeof(buf
) - nowlen
- 1;
964 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
965 buf
[nowlen
+ msglen
] = '\0';
967 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
969 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
970 ssh2_disconnect_reasons
[reason
] : "unknown",
978 static void ssh1_pktout_size(int len
)
982 len
+= 5; /* type and CRC */
986 pktout
.length
= len
- 5;
987 if (pktout
.maxlen
< biglen
) {
988 pktout
.maxlen
= biglen
;
990 /* Allocate enough buffer space for extra block
991 * for MS CryptEncrypt() */
992 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
993 srealloc(pktout
.data
, biglen
+ 12));
995 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
996 srealloc(pktout
.data
, biglen
+ 4));
999 fatalbox("Out of memory");
1001 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
1004 static void s_wrpkt_start(int type
, int len
)
1006 ssh1_pktout_size(len
);
1010 static int s_wrpkt_prepare(void)
1012 int pad
, len
, biglen
, i
;
1015 pktout
.body
[-1] = pktout
.type
;
1017 log_packet(PKT_OUTGOING
, pktout
.type
, ssh1_pkt_type(pktout
.type
),
1018 pktout
.body
, pktout
.length
);
1020 if (ssh1_compressing
) {
1021 unsigned char *compblk
;
1023 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
1024 &compblk
, &complen
);
1025 ssh1_pktout_size(complen
- 1);
1026 memcpy(pktout
.body
- 1, compblk
, complen
);
1030 len
= pktout
.length
+ 5; /* type and CRC */
1031 pad
= 8 - (len
% 8);
1034 for (i
= 0; i
< pad
; i
++)
1035 pktout
.data
[i
+ 4] = random_byte();
1036 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
1037 PUT_32BIT(pktout
.data
+ biglen
, crc
);
1038 PUT_32BIT(pktout
.data
, len
);
1041 cipher
->encrypt(pktout
.data
+ 4, biglen
);
1046 static void s_wrpkt(void)
1049 len
= s_wrpkt_prepare();
1050 backlog
= sk_write(s
, pktout
.data
, len
);
1051 if (backlog
> SSH_MAX_BACKLOG
)
1052 ssh_throttle_all(1, backlog
);
1055 static void s_wrpkt_defer(void)
1058 len
= s_wrpkt_prepare();
1059 if (deferred_len
+ len
> deferred_size
) {
1060 deferred_size
= deferred_len
+ len
+ 128;
1061 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1063 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1064 deferred_len
+= len
;
1068 * Construct a packet with the specified contents.
1070 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1072 unsigned char *p
, *argp
, argchar
;
1073 unsigned long argint
;
1074 int pktlen
, argtype
, arglen
;
1078 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1081 (void) va_arg(ap1
, int);
1085 (void) va_arg(ap1
, char);
1089 (void) va_arg(ap1
, unsigned char *);
1090 arglen
= va_arg(ap1
, int);
1094 argp
= va_arg(ap1
, unsigned char *);
1095 arglen
= strlen(argp
);
1096 pktlen
+= 4 + arglen
;
1099 bn
= va_arg(ap1
, Bignum
);
1100 pktlen
+= ssh1_bignum_length(bn
);
1107 s_wrpkt_start(pkttype
, pktlen
);
1110 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1113 argint
= va_arg(ap2
, int);
1114 PUT_32BIT(p
, argint
);
1118 argchar
= va_arg(ap2
, unsigned char);
1123 argp
= va_arg(ap2
, unsigned char *);
1124 arglen
= va_arg(ap2
, int);
1125 memcpy(p
, argp
, arglen
);
1129 argp
= va_arg(ap2
, unsigned char *);
1130 arglen
= strlen(argp
);
1131 PUT_32BIT(p
, arglen
);
1132 memcpy(p
+ 4, argp
, arglen
);
1136 bn
= va_arg(ap2
, Bignum
);
1137 p
+= ssh1_write_bignum(p
, bn
);
1143 static void send_packet(int pkttype
, ...)
1146 va_start(ap1
, pkttype
);
1147 va_start(ap2
, pkttype
);
1148 construct_packet(pkttype
, ap1
, ap2
);
1152 static void defer_packet(int pkttype
, ...)
1155 va_start(ap1
, pkttype
);
1156 va_start(ap2
, pkttype
);
1157 construct_packet(pkttype
, ap1
, ap2
);
1161 static int ssh_versioncmp(char *a
, char *b
)
1164 unsigned long av
, bv
;
1166 av
= strtoul(a
, &ae
, 10);
1167 bv
= strtoul(b
, &be
, 10);
1169 return (av
< bv ?
-1 : +1);
1174 av
= strtoul(ae
, &ae
, 10);
1175 bv
= strtoul(be
, &be
, 10);
1177 return (av
< bv ?
-1 : +1);
1183 * Utility routines for putting an SSH-protocol `string' and
1184 * `uint32' into a SHA state.
1187 static void sha_string(SHA_State
* s
, void *str
, int len
)
1189 unsigned char lenblk
[4];
1190 PUT_32BIT(lenblk
, len
);
1191 SHA_Bytes(s
, lenblk
, 4);
1192 SHA_Bytes(s
, str
, len
);
1195 static void sha_uint32(SHA_State
* s
, unsigned i
)
1197 unsigned char intblk
[4];
1198 PUT_32BIT(intblk
, i
);
1199 SHA_Bytes(s
, intblk
, 4);
1203 * SSH2 packet construction functions.
1205 static void ssh2_pkt_ensure(int length
)
1207 if (pktout
.maxlen
< length
) {
1208 pktout
.maxlen
= length
+ 256;
1211 NULL ?
smalloc(pktout
.maxlen
+
1212 APIEXTRA
) : srealloc(pktout
.data
,
1216 fatalbox("Out of memory");
1219 static void ssh2_pkt_adddata(void *data
, int len
)
1221 pktout
.length
+= len
;
1222 ssh2_pkt_ensure(pktout
.length
);
1223 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1225 static void ssh2_pkt_addbyte(unsigned char byte
)
1227 ssh2_pkt_adddata(&byte
, 1);
1229 static void ssh2_pkt_init(int pkt_type
)
1232 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1234 static void ssh2_pkt_addbool(unsigned char value
)
1236 ssh2_pkt_adddata(&value
, 1);
1238 static void ssh2_pkt_adduint32(unsigned long value
)
1241 PUT_32BIT(x
, value
);
1242 ssh2_pkt_adddata(x
, 4);
1244 static void ssh2_pkt_addstring_start(void)
1246 ssh2_pkt_adduint32(0);
1247 pktout
.savedpos
= pktout
.length
;
1249 static void ssh2_pkt_addstring_str(char *data
)
1251 ssh2_pkt_adddata(data
, strlen(data
));
1252 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1253 pktout
.length
- pktout
.savedpos
);
1255 static void ssh2_pkt_addstring_data(char *data
, int len
)
1257 ssh2_pkt_adddata(data
, len
);
1258 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1259 pktout
.length
- pktout
.savedpos
);
1261 static void ssh2_pkt_addstring(char *data
)
1263 ssh2_pkt_addstring_start();
1264 ssh2_pkt_addstring_str(data
);
1266 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1269 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1272 fatalbox("out of memory");
1274 for (i
= 1; i
<= n
; i
++)
1275 p
[i
] = bignum_byte(b
, n
- i
);
1277 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1279 memmove(p
, p
+ i
, n
+ 1 - i
);
1283 static void ssh2_pkt_addmp(Bignum b
)
1287 p
= ssh2_mpint_fmt(b
, &len
);
1288 ssh2_pkt_addstring_start();
1289 ssh2_pkt_addstring_data(p
, len
);
1294 * Construct an SSH2 final-form packet: compress it, encrypt it,
1295 * put the MAC on it. Final packet, ready to be sent, is stored in
1296 * pktout.data. Total length is returned.
1298 static int ssh2_pkt_construct(void)
1300 int cipherblk
, maclen
, padding
, i
;
1301 static unsigned long outgoing_sequence
= 0;
1303 log_packet(PKT_OUTGOING
, pktout
.data
[5], ssh2_pkt_type(pktout
.data
[5]),
1304 pktout
.data
+ 6, pktout
.length
- 6);
1307 * Compress packet payload.
1310 unsigned char *newpayload
;
1312 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1313 &newpayload
, &newlen
)) {
1315 ssh2_pkt_adddata(newpayload
, newlen
);
1321 * Add padding. At least four bytes, and must also bring total
1322 * length (minus MAC) up to a multiple of the block size.
1324 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1325 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1328 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1329 maclen
= csmac ? csmac
->len
: 0;
1330 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1331 pktout
.data
[4] = padding
;
1332 for (i
= 0; i
< padding
; i
++)
1333 pktout
.data
[pktout
.length
+ i
] = random_byte();
1334 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1336 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1338 outgoing_sequence
++; /* whether or not we MACed */
1341 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1343 /* Ready-to-send packet starts at pktout.data. We return length. */
1344 return pktout
.length
+ padding
+ maclen
;
1348 * Construct and send an SSH2 packet immediately.
1350 static void ssh2_pkt_send(void)
1354 len
= ssh2_pkt_construct();
1355 backlog
= sk_write(s
, pktout
.data
, len
);
1356 if (backlog
> SSH_MAX_BACKLOG
)
1357 ssh_throttle_all(1, backlog
);
1361 * Construct an SSH2 packet and add it to a deferred data block.
1362 * Useful for sending multiple packets in a single sk_write() call,
1363 * to prevent a traffic-analysing listener from being able to work
1364 * out the length of any particular packet (such as the password
1367 * Note that because SSH2 sequence-numbers its packets, this can
1368 * NOT be used as an m4-style `defer' allowing packets to be
1369 * constructed in one order and sent in another.
1371 static void ssh2_pkt_defer(void)
1373 int len
= ssh2_pkt_construct();
1374 if (deferred_len
+ len
> deferred_size
) {
1375 deferred_size
= deferred_len
+ len
+ 128;
1376 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1378 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1379 deferred_len
+= len
;
1383 * Send the whole deferred data block constructed by
1384 * ssh2_pkt_defer() or SSH1's defer_packet().
1386 static void ssh_pkt_defersend(void)
1389 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1390 deferred_len
= deferred_size
= 0;
1391 sfree(deferred_send_data
);
1392 deferred_send_data
= NULL
;
1393 if (backlog
> SSH_MAX_BACKLOG
)
1394 ssh_throttle_all(1, backlog
);
1398 void bndebug(char *string
, Bignum b
)
1402 p
= ssh2_mpint_fmt(b
, &len
);
1403 debug(("%s", string
));
1404 for (i
= 0; i
< len
; i
++)
1405 debug((" %02x", p
[i
]));
1411 static void sha_mpint(SHA_State
* s
, Bignum b
)
1415 p
= ssh2_mpint_fmt(b
, &len
);
1416 sha_string(s
, p
, len
);
1421 * SSH2 packet decode functions.
1423 static unsigned long ssh2_pkt_getuint32(void)
1425 unsigned long value
;
1426 if (pktin
.length
- pktin
.savedpos
< 4)
1427 return 0; /* arrgh, no way to decline (FIXME?) */
1428 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1429 pktin
.savedpos
+= 4;
1432 static int ssh2_pkt_getbool(void)
1434 unsigned long value
;
1435 if (pktin
.length
- pktin
.savedpos
< 1)
1436 return 0; /* arrgh, no way to decline (FIXME?) */
1437 value
= pktin
.data
[pktin
.savedpos
] != 0;
1441 static void ssh2_pkt_getstring(char **p
, int *length
)
1444 if (pktin
.length
- pktin
.savedpos
< 4)
1446 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1447 pktin
.savedpos
+= 4;
1448 if (pktin
.length
- pktin
.savedpos
< *length
)
1450 *p
= pktin
.data
+ pktin
.savedpos
;
1451 pktin
.savedpos
+= *length
;
1453 static Bignum
ssh2_pkt_getmp(void)
1459 ssh2_pkt_getstring(&p
, &length
);
1463 bombout(("internal error: Can't handle negative mpints"));
1466 b
= bignum_from_bytes(p
, length
);
1471 * Examine the remote side's version string and compare it against
1472 * a list of known buggy implementations.
1474 static void ssh_detect_bugs(char *vstring
)
1476 char *imp
; /* pointer to implementation part */
1478 imp
+= strcspn(imp
, "-");
1480 imp
+= strcspn(imp
, "-");
1483 ssh_remote_bugs
= 0;
1485 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1486 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1487 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1489 * These versions don't support SSH1_MSG_IGNORE, so we have
1490 * to use a different defence against password length
1493 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1494 logevent("We believe remote version has SSH1 ignore bug");
1497 if (!strcmp(imp
, "Cisco-1.25")) {
1499 * These versions need a plain password sent; they can't
1500 * handle having a null and a random length of data after
1503 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1504 logevent("We believe remote version needs a plain SSH1 password");
1507 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1508 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1509 !strncmp(imp
, "2.1 ", 4)) {
1511 * These versions have the HMAC bug.
1513 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1514 logevent("We believe remote version has SSH2 HMAC bug");
1518 static int do_ssh_init(unsigned char c
)
1521 static char version
[10];
1522 static char *vstring
;
1523 static int vstrsize
;
1529 /* Search for the string "SSH-" in the input. */
1532 static const int transS
[] = { 1, 2, 2, 1 };
1533 static const int transH
[] = { 0, 0, 3, 0 };
1534 static const int transminus
[] = { 0, 0, 0, -1 };
1545 crReturn(1); /* get another character */
1549 vstring
= smalloc(vstrsize
);
1550 strcpy(vstring
, "SSH-");
1554 crReturn(1); /* get another char */
1555 if (vslen
>= vstrsize
- 1) {
1557 vstring
= srealloc(vstring
, vstrsize
);
1559 vstring
[vslen
++] = c
;
1564 } else if (i
< sizeof(version
) - 1)
1566 } else if (c
== '\n')
1570 ssh_agentfwd_enabled
= FALSE
;
1571 rdpkt2_state
.incoming_sequence
= 0;
1574 vlog
= smalloc(20 + vslen
);
1575 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1576 sprintf(vlog
, "Server version: %s", vstring
);
1578 ssh_detect_bugs(vstring
);
1582 * Server version "1.99" means we can choose whether we use v1
1583 * or v2 protocol. Choice is based on cfg.sshprot.
1585 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1587 * This is a v2 server. Begin v2 protocol.
1589 char verstring
[80], vlog
[100];
1590 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1591 SHA_Init(&exhashbase
);
1593 * Hash our version string and their version string.
1595 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1596 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1597 sprintf(vlog
, "We claim version: %s", verstring
);
1599 strcat(verstring
, "\n");
1600 logevent("Using SSH protocol version 2");
1601 sk_write(s
, verstring
, strlen(verstring
));
1602 ssh_protocol
= ssh2_protocol
;
1604 s_rdpkt
= ssh2_rdpkt
;
1607 * This is a v1 server. Begin v1 protocol.
1609 char verstring
[80], vlog
[100];
1610 sprintf(verstring
, "SSH-%s-%s",
1611 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1613 sprintf(vlog
, "We claim version: %s", verstring
);
1615 strcat(verstring
, "\n");
1616 logevent("Using SSH protocol version 1");
1617 sk_write(s
, verstring
, strlen(verstring
));
1618 ssh_protocol
= ssh1_protocol
;
1620 s_rdpkt
= ssh1_rdpkt
;
1622 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1629 static void ssh_gotdata(unsigned char *data
, int datalen
)
1634 * To begin with, feed the characters one by one to the
1635 * protocol initialisation / selection function do_ssh_init().
1636 * When that returns 0, we're done with the initial greeting
1637 * exchange and can move on to packet discipline.
1642 crReturnV
; /* more data please */
1643 ret
= do_ssh_init(*data
);
1651 * We emerge from that loop when the initial negotiation is
1652 * over and we have selected an s_rdpkt function. Now pass
1653 * everything to s_rdpkt, and then pass the resulting packets
1654 * to the proper protocol handler.
1659 while (datalen
> 0) {
1660 if (s_rdpkt(&data
, &datalen
) == 0) {
1661 if (ssh_state
== SSH_STATE_CLOSED
) {
1664 ssh_protocol(NULL
, 0, 1);
1665 if (ssh_state
== SSH_STATE_CLOSED
) {
1675 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1678 ssh_state
= SSH_STATE_CLOSED
;
1684 /* A socket error has occurred. */
1685 connection_fatal(error_msg
);
1687 /* Otherwise, the remote side closed the connection normally. */
1692 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1694 ssh_gotdata(data
, len
);
1695 if (ssh_state
== SSH_STATE_CLOSED
) {
1705 static void ssh_sent(Plug plug
, int bufsize
)
1708 * If the send backlog on the SSH socket itself clears, we
1709 * should unthrottle the whole world if it was throttled.
1711 if (bufsize
< SSH_MAX_BACKLOG
)
1712 ssh_throttle_all(0, bufsize
);
1716 * Connect to specified host and port.
1717 * Returns an error message, or NULL on success.
1718 * Also places the canonical host name into `realhost'. It must be
1719 * freed by the caller.
1721 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1723 static struct plug_function_table fn_table
= {
1728 }, *fn_table_ptr
= &fn_table
;
1737 savedhost
= smalloc(1 + strlen(host
));
1739 fatalbox("Out of memory");
1740 strcpy(savedhost
, host
);
1743 port
= 22; /* default ssh port */
1758 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1761 addr
= sk_namelookup(host
, realhost
);
1762 if ((err
= sk_addr_error(addr
)))
1766 *realhost
= strdup(FWhost
);
1773 char buf
[200], addrbuf
[100];
1774 sk_getaddr(addr
, addrbuf
, 100);
1775 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1778 s
= sk_new(addr
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1779 if ((err
= sk_socket_error(s
)))
1783 sk_write(s
, "connect ", 8);
1784 sk_write(s
, FWhost
, strlen(FWhost
));
1787 sprintf(buf
, " %d\n", FWport
);
1788 sk_write(s
, buf
, strlen(buf
));
1796 * Throttle or unthrottle the SSH connection.
1798 static void ssh1_throttle(int adjust
)
1800 int old_count
= ssh1_throttle_count
;
1801 ssh1_throttle_count
+= adjust
;
1802 assert(ssh1_throttle_count
>= 0);
1803 if (ssh1_throttle_count
&& !old_count
) {
1804 sk_set_frozen(s
, 1);
1805 } else if (!ssh1_throttle_count
&& old_count
) {
1806 sk_set_frozen(s
, 0);
1811 * Throttle or unthrottle _all_ local data streams (for when sends
1812 * on the SSH connection itself back up).
1814 static void ssh_throttle_all(int enable
, int bufsize
)
1817 struct ssh_channel
*c
;
1819 if (enable
== ssh_throttled_all
)
1821 ssh_throttled_all
= enable
;
1822 ssh_overall_bufsize
= bufsize
;
1825 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
1827 case CHAN_MAINSESSION
:
1829 * This is treated separately, outside the switch.
1833 x11_override_throttle(c
->u
.x11
.s
, enable
);
1836 /* Agent channels require no buffer management. */
1839 pfd_override_throttle(c
->u
.x11
.s
, enable
);
1846 * Handle the key exchange and user authentication phases.
1848 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1852 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
1853 unsigned char cookie
[8];
1854 struct RSAKey servkey
, hostkey
;
1855 struct MD5Context md5c
;
1856 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1857 static int tried_publickey
, tried_agent
;
1858 static int tis_auth_refused
, ccard_auth_refused
;
1859 static unsigned char session_id
[16];
1860 static int cipher_type
;
1861 static char username
[100];
1862 static void *publickey_blob
;
1863 int publickey_bloblen
;
1870 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1871 bombout(("Public key packet not received"));
1875 logevent("Received public keys");
1877 memcpy(cookie
, pktin
.body
, 8);
1879 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1880 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
1883 * Log the host key fingerprint.
1887 logevent("Host key fingerprint is:");
1888 strcpy(logmsg
, " ");
1889 hostkey
.comment
= NULL
;
1890 rsa_fingerprint(logmsg
+ strlen(logmsg
),
1891 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
1895 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
1896 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
1897 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
1899 ssh1_local_protoflags
=
1900 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1901 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1904 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1905 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1906 MD5Update(&md5c
, pktin
.body
, 8);
1907 MD5Final(session_id
, &md5c
);
1909 for (i
= 0; i
< 32; i
++)
1910 session_key
[i
] = random_byte();
1912 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1914 rsabuf
= smalloc(len
);
1916 fatalbox("Out of memory");
1919 * Verify the host key.
1923 * First format the key into a string.
1925 int len
= rsastr_len(&hostkey
);
1926 char fingerprint
[100];
1927 char *keystr
= smalloc(len
);
1929 fatalbox("Out of memory");
1930 rsastr_fmt(keystr
, &hostkey
);
1931 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1932 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
1937 for (i
= 0; i
< 32; i
++) {
1938 rsabuf
[i
] = session_key
[i
];
1940 rsabuf
[i
] ^= session_id
[i
];
1943 if (hostkey
.bytes
> servkey
.bytes
) {
1944 rsaencrypt(rsabuf
, 32, &servkey
);
1945 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1947 rsaencrypt(rsabuf
, 32, &hostkey
);
1948 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1951 logevent("Encrypted session key");
1954 int cipher_chosen
= 0, warn
= 0;
1955 char *cipher_string
= NULL
;
1956 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
1957 int next_cipher
= cfg
.ssh_cipherlist
[i
];
1958 if (next_cipher
== CIPHER_WARN
) {
1959 /* If/when we choose a cipher, warn about it */
1961 } else if (next_cipher
== CIPHER_AES
) {
1962 /* XXX Probably don't need to mention this. */
1963 logevent("AES not supported in SSH1, skipping");
1965 switch (next_cipher
) {
1966 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
1967 cipher_string
= "3DES"; break;
1968 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
1969 cipher_string
= "Blowfish"; break;
1970 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
1971 cipher_string
= "single-DES"; break;
1973 if (supported_ciphers_mask
& (1 << cipher_type
))
1977 if (!cipher_chosen
) {
1978 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
1979 bombout(("Server violates SSH 1 protocol by not "
1980 "supporting 3DES encryption"));
1982 /* shouldn't happen */
1983 bombout(("No supported ciphers found"));
1987 /* Warn about chosen cipher if necessary. */
1989 askcipher(cipher_string
, 0);
1992 switch (cipher_type
) {
1993 case SSH_CIPHER_3DES
:
1994 logevent("Using 3DES encryption");
1996 case SSH_CIPHER_DES
:
1997 logevent("Using single-DES encryption");
1999 case SSH_CIPHER_BLOWFISH
:
2000 logevent("Using Blowfish encryption");
2004 send_packet(SSH1_CMSG_SESSION_KEY
,
2005 PKT_CHAR
, cipher_type
,
2006 PKT_DATA
, cookie
, 8,
2007 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
2008 PKT_DATA
, rsabuf
, len
,
2009 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
2011 logevent("Trying to enable encryption...");
2015 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2016 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
2017 cipher
->sesskey(session_key
);
2021 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2022 bombout(("Encryption not successfully enabled"));
2026 logevent("Successfully started encryption");
2032 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2034 if (!ssh_get_line("login as: ",
2035 username
, sizeof(username
), FALSE
)) {
2037 * get_line failed to get a username.
2040 logevent("No username provided. Abandoning session.");
2041 ssh_state
= SSH_STATE_CLOSED
;
2045 c_write_str("login as: ");
2048 crWaitUntil(!ispkt
);
2050 switch (c
= *in
++) {
2059 c_write_str("\b \b");
2066 c_write_str("\b \b");
2076 if (((c
>= ' ' && c
<= '~') ||
2077 ((unsigned char) c
>= 160))
2078 && pos
< sizeof(username
)-1) {
2079 username
[pos
++] = c
;
2085 c_write_str("\r\n");
2086 username
[strcspn(username
, "\n\r")] = '\0';
2089 strncpy(username
, cfg
.username
, 99);
2090 username
[99] = '\0';
2093 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2095 char userlog
[22 + sizeof(username
)];
2096 sprintf(userlog
, "Sent username \"%s\"", username
);
2098 if (flags
& FLAG_INTERACTIVE
&&
2099 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2100 strcat(userlog
, "\r\n");
2101 c_write_str(userlog
);
2108 tried_publickey
= tried_agent
= 0;
2109 tis_auth_refused
= ccard_auth_refused
= 0;
2110 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2112 if (!rsakey_pubblob(cfg
.keyfile
, &publickey_blob
, &publickey_bloblen
))
2113 publickey_blob
= NULL
;
2115 publickey_blob
= NULL
;
2117 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2118 static char password
[100];
2119 static char prompt
[200];
2122 static int pwpkt_type
;
2123 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2125 if (agent_exists() && !tried_agent
) {
2127 * Attempt RSA authentication using Pageant.
2129 static unsigned char request
[5], *response
, *p
;
2130 static int responselen
;
2131 static int i
, nkeys
;
2132 static int authed
= FALSE
;
2136 logevent("Pageant is running. Requesting keys.");
2138 /* Request the keys held by the agent. */
2139 PUT_32BIT(request
, 1);
2140 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2141 agent_query(request
, 5, &r
, &responselen
);
2142 response
= (unsigned char *) r
;
2143 if (response
&& responselen
>= 5 &&
2144 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2146 nkeys
= GET_32BIT(p
);
2150 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2153 for (i
= 0; i
< nkeys
; i
++) {
2154 static struct RSAKey key
;
2155 static Bignum challenge
;
2156 static char *commentp
;
2157 static int commentlen
;
2161 sprintf(buf
, "Trying Pageant key #%d", i
);
2164 if (publickey_blob
&&
2165 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
2166 logevent("This key matches configured key file");
2167 tried_publickey
= 1;
2170 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2171 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2172 commentlen
= GET_32BIT(p
);
2176 send_packet(SSH1_CMSG_AUTH_RSA
,
2177 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2179 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2180 logevent("Key refused");
2183 logevent("Received RSA challenge");
2184 ssh1_read_bignum(pktin
.body
, &challenge
);
2186 char *agentreq
, *q
, *ret
;
2189 len
= 1 + 4; /* message type, bit count */
2190 len
+= ssh1_bignum_length(key
.exponent
);
2191 len
+= ssh1_bignum_length(key
.modulus
);
2192 len
+= ssh1_bignum_length(challenge
);
2193 len
+= 16; /* session id */
2194 len
+= 4; /* response format */
2195 agentreq
= smalloc(4 + len
);
2196 PUT_32BIT(agentreq
, len
);
2198 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2199 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2201 q
+= ssh1_write_bignum(q
, key
.exponent
);
2202 q
+= ssh1_write_bignum(q
, key
.modulus
);
2203 q
+= ssh1_write_bignum(q
, challenge
);
2204 memcpy(q
, session_id
, 16);
2206 PUT_32BIT(q
, 1); /* response format */
2207 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2211 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2212 logevent("Sending Pageant's response");
2213 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2214 PKT_DATA
, ret
+ 5, 16,
2218 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2220 ("Pageant's response accepted");
2221 if (flags
& FLAG_VERBOSE
) {
2223 ("Authenticated using RSA key \"");
2224 c_write(commentp
, commentlen
);
2225 c_write_str("\" from agent\r\n");
2230 ("Pageant's response not accepted");
2233 ("Pageant failed to answer challenge");
2237 logevent("No reply received from Pageant");
2240 freebn(key
.exponent
);
2241 freebn(key
.modulus
);
2250 if (*cfg
.keyfile
&& !tried_publickey
)
2251 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2253 if (cfg
.try_tis_auth
&&
2254 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2255 !tis_auth_refused
) {
2256 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2257 logevent("Requested TIS authentication");
2258 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2260 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2261 logevent("TIS authentication declined");
2262 if (flags
& FLAG_INTERACTIVE
)
2263 c_write_str("TIS authentication refused.\r\n");
2264 tis_auth_refused
= 1;
2267 int challengelen
= ((pktin
.body
[0] << 24) |
2268 (pktin
.body
[1] << 16) |
2269 (pktin
.body
[2] << 8) |
2271 logevent("Received TIS challenge");
2272 if (challengelen
> sizeof(prompt
) - 1)
2273 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2274 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2275 /* Prompt heuristic comes from OpenSSH */
2276 strncpy(prompt
+ challengelen
,
2277 memchr(prompt
, '\n', challengelen
) ?
2278 "": "\r\nResponse: ",
2279 (sizeof prompt
) - challengelen
);
2280 prompt
[(sizeof prompt
) - 1] = '\0';
2283 if (cfg
.try_tis_auth
&&
2284 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2285 !ccard_auth_refused
) {
2286 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2287 logevent("Requested CryptoCard authentication");
2288 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2290 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2291 logevent("CryptoCard authentication declined");
2292 c_write_str("CryptoCard authentication refused.\r\n");
2293 ccard_auth_refused
= 1;
2296 int challengelen
= ((pktin
.body
[0] << 24) |
2297 (pktin
.body
[1] << 16) |
2298 (pktin
.body
[2] << 8) |
2300 logevent("Received CryptoCard challenge");
2301 if (challengelen
> sizeof(prompt
) - 1)
2302 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2303 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2304 strncpy(prompt
+ challengelen
,
2305 memchr(prompt
, '\n', challengelen
) ?
2306 "" : "\r\nResponse: ",
2307 sizeof(prompt
) - challengelen
);
2308 prompt
[sizeof(prompt
) - 1] = '\0';
2311 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2312 sprintf(prompt
, "%.90s@%.90s's password: ",
2313 username
, savedhost
);
2315 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2316 char *comment
= NULL
;
2317 if (flags
& FLAG_VERBOSE
)
2318 c_write_str("Trying public key authentication.\r\n");
2319 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2320 if (flags
& FLAG_VERBOSE
)
2321 c_write_str("No passphrase required.\r\n");
2324 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2329 * Show password prompt, having first obtained it via a TIS
2330 * or CryptoCard exchange if we're doing TIS or CryptoCard
2334 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2336 * get_line failed to get a password (for example
2337 * because one was supplied on the command line
2338 * which has already failed to work). Terminate.
2340 send_packet(SSH1_MSG_DISCONNECT
,
2341 PKT_STR
, "No more passwords available to try",
2343 connection_fatal("Unable to authenticate");
2344 ssh_state
= SSH_STATE_CLOSED
;
2348 /* Prompt may have come from server. We've munged it a bit, so
2349 * we know it to be zero-terminated at least once. */
2350 c_write_untrusted(prompt
, strlen(prompt
));
2354 crWaitUntil(!ispkt
);
2356 switch (c
= *in
++) {
2377 if (pos
< sizeof(password
)-1)
2378 password
[pos
++] = c
;
2382 c_write_str("\r\n");
2386 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2388 * Try public key authentication with the specified
2391 static struct RSAKey pubkey
;
2392 static Bignum challenge
, response
;
2394 static unsigned char buffer
[32];
2396 tried_publickey
= 1;
2397 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2399 c_write_str("Couldn't load private key from ");
2400 c_write_str(cfg
.keyfile
);
2401 c_write_str(".\r\n");
2402 continue; /* go and try password */
2405 c_write_str("Wrong passphrase.\r\n");
2406 tried_publickey
= 0;
2407 continue; /* try again */
2411 * Send a public key attempt.
2413 send_packet(SSH1_CMSG_AUTH_RSA
,
2414 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2417 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2418 c_write_str("Server refused our public key.\r\n");
2419 continue; /* go and try password */
2421 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2422 bombout(("Bizarre response to offer of public key"));
2425 ssh1_read_bignum(pktin
.body
, &challenge
);
2426 response
= rsadecrypt(challenge
, &pubkey
);
2427 freebn(pubkey
.private_exponent
); /* burn the evidence */
2429 for (i
= 0; i
< 32; i
++) {
2430 buffer
[i
] = bignum_byte(response
, 31 - i
);
2434 MD5Update(&md5c
, buffer
, 32);
2435 MD5Update(&md5c
, session_id
, 16);
2436 MD5Final(buffer
, &md5c
);
2438 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2439 PKT_DATA
, buffer
, 16, PKT_END
);
2442 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2443 if (flags
& FLAG_VERBOSE
)
2445 ("Failed to authenticate with our public key.\r\n");
2446 continue; /* go and try password */
2447 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2449 ("Bizarre response to RSA authentication response"));
2453 break; /* we're through! */
2455 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2457 * Defence against traffic analysis: we send a
2458 * whole bunch of packets containing strings of
2459 * different lengths. One of these strings is the
2460 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2461 * The others are all random data in
2462 * SSH1_MSG_IGNORE packets. This way a passive
2463 * listener can't tell which is the password, and
2464 * hence can't deduce the password length.
2466 * Anybody with a password length greater than 16
2467 * bytes is going to have enough entropy in their
2468 * password that a listener won't find it _that_
2469 * much help to know how long it is. So what we'll
2472 * - if password length < 16, we send 15 packets
2473 * containing string lengths 1 through 15
2475 * - otherwise, we let N be the nearest multiple
2476 * of 8 below the password length, and send 8
2477 * packets containing string lengths N through
2478 * N+7. This won't obscure the order of
2479 * magnitude of the password length, but it will
2480 * introduce a bit of extra uncertainty.
2482 * A few servers (the old 1.2.18 through 1.2.22)
2483 * can't deal with SSH1_MSG_IGNORE. For these
2484 * servers, we need an alternative defence. We make
2485 * use of the fact that the password is interpreted
2486 * as a C string: so we can append a NUL, then some
2489 * One server (a Cisco one) can deal with neither
2490 * SSH1_MSG_IGNORE _nor_ a padded password string.
2491 * For this server we are left with no defences
2492 * against password length sniffing.
2494 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2496 * The server can deal with SSH1_MSG_IGNORE, so
2497 * we can use the primary defence.
2499 int bottom
, top
, pwlen
, i
;
2502 pwlen
= strlen(password
);
2504 bottom
= 0; /* zero length passwords are OK! :-) */
2507 bottom
= pwlen
& ~7;
2511 assert(pwlen
>= bottom
&& pwlen
<= top
);
2513 randomstr
= smalloc(top
+ 1);
2515 for (i
= bottom
; i
<= top
; i
++) {
2517 defer_packet(pwpkt_type
, PKT_STR
, password
,
2520 for (j
= 0; j
< i
; j
++) {
2522 randomstr
[j
] = random_byte();
2523 } while (randomstr
[j
] == '\0');
2525 randomstr
[i
] = '\0';
2526 defer_packet(SSH1_MSG_IGNORE
,
2527 PKT_STR
, randomstr
, PKT_END
);
2530 logevent("Sending password with camouflage packets");
2531 ssh_pkt_defersend();
2533 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2535 * The server can't deal with SSH1_MSG_IGNORE
2536 * but can deal with padded passwords, so we
2537 * can use the secondary defence.
2543 len
= strlen(password
);
2544 if (len
< sizeof(string
)) {
2546 strcpy(string
, password
);
2547 len
++; /* cover the zero byte */
2548 while (len
< sizeof(string
)) {
2549 string
[len
++] = (char) random_byte();
2554 logevent("Sending length-padded password");
2555 send_packet(pwpkt_type
, PKT_INT
, len
,
2556 PKT_DATA
, s
, len
, PKT_END
);
2559 * The server has _both_
2560 * BUG_CHOKES_ON_SSH1_IGNORE and
2561 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2562 * therefore nothing we can do.
2565 len
= strlen(password
);
2566 logevent("Sending unpadded password");
2567 send_packet(pwpkt_type
, PKT_INT
, len
,
2568 PKT_DATA
, password
, len
, PKT_END
);
2571 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2574 logevent("Sent password");
2575 memset(password
, 0, strlen(password
));
2577 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2578 if (flags
& FLAG_VERBOSE
)
2579 c_write_str("Access denied\r\n");
2580 logevent("Authentication refused");
2581 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2582 logevent("Received disconnect request");
2583 ssh_state
= SSH_STATE_CLOSED
;
2585 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2586 bombout(("Strange packet received, type %d", pktin
.type
));
2591 logevent("Authentication successful");
2596 void sshfwd_close(struct ssh_channel
*c
)
2598 if (c
&& !c
->closes
) {
2600 * If the channel's remoteid is -1, we have sent
2601 * CHANNEL_OPEN for this channel, but it hasn't even been
2602 * acknowledged by the server. So we must set a close flag
2603 * on it now, and then when the server acks the channel
2604 * open, we can close it then.
2606 if (c
->remoteid
!= -1) {
2607 if (ssh_version
== 1) {
2608 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2611 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2612 ssh2_pkt_adduint32(c
->remoteid
);
2617 if (c
->type
== CHAN_X11
) {
2619 logevent("Forwarded X11 connection terminated");
2620 } else if (c
->type
== CHAN_SOCKDATA
||
2621 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2623 logevent("Forwarded port closed");
2628 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2630 if (ssh_version
== 1) {
2631 send_packet(SSH1_MSG_CHANNEL_DATA
,
2632 PKT_INT
, c
->remoteid
,
2633 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2635 * In SSH1 we can return 0 here - implying that forwarded
2636 * connections are never individually throttled - because
2637 * the only circumstance that can cause throttling will be
2638 * the whole SSH connection backing up, in which case
2639 * _everything_ will be throttled as a whole.
2643 ssh2_add_channel_data(c
, buf
, len
);
2644 return ssh2_try_send(c
);
2648 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2650 if (ssh_version
== 1) {
2651 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2652 c
->v
.v1
.throttling
= 0;
2656 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2660 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2666 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2669 if (ssh_state
== SSH_STATE_CLOSED
)
2672 if (cfg
.agentfwd
&& agent_exists()) {
2673 logevent("Requesting agent forwarding");
2674 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2678 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2679 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2680 bombout(("Protocol confusion"));
2682 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2683 logevent("Agent forwarding refused");
2685 logevent("Agent forwarding enabled");
2686 ssh_agentfwd_enabled
= TRUE
;
2690 if (cfg
.x11_forward
) {
2691 char proto
[20], data
[64];
2692 logevent("Requesting X11 forwarding");
2693 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2694 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2695 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2696 PKT_STR
, proto
, PKT_STR
, data
,
2697 PKT_INT
, 0, PKT_END
);
2699 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2700 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2705 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2706 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2707 bombout(("Protocol confusion"));
2709 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2710 logevent("X11 forwarding refused");
2712 logevent("X11 forwarding enabled");
2713 ssh_X11_fwd_enabled
= TRUE
;
2721 char sports
[256], dports
[256], host
[256];
2724 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2725 /* Add port forwardings. */
2730 while (*e
&& *e
!= '\t')
2736 while (*e
&& *e
!= ':')
2746 dport
= atoi(dports
);
2747 sport
= atoi(sports
);
2748 if (sport
&& dport
) {
2750 pfd_addforward(host
, dport
, sport
);
2751 sprintf(buf
, "Local port %d forwarding to %s:%d",
2752 sport
, host
, dport
);
2755 struct ssh_rportfwd
*pf
;
2756 pf
= smalloc(sizeof(*pf
));
2757 strcpy(pf
->dhost
, host
);
2759 if (add234(ssh_rportfwds
, pf
) != pf
) {
2761 "Duplicate remote port forwarding to %s:%d",
2766 sprintf(buf
, "Requesting remote port %d forward to %s:%d",
2767 sport
, host
, dport
);
2769 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2781 send_packet(SSH1_CMSG_REQUEST_PTY
,
2782 PKT_STR
, cfg
.termtype
,
2783 PKT_INT
, rows
, PKT_INT
, cols
,
2784 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2785 ssh_state
= SSH_STATE_INTERMED
;
2789 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2790 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2791 bombout(("Protocol confusion"));
2793 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2794 c_write_str("Server refused to allocate pty\r\n");
2795 ssh_editing
= ssh_echoing
= 1;
2797 logevent("Allocated pty");
2799 ssh_editing
= ssh_echoing
= 1;
2802 if (cfg
.compression
) {
2803 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2807 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2808 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2809 bombout(("Protocol confusion"));
2811 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2812 c_write_str("Server refused to compress\r\n");
2814 logevent("Started compression");
2815 ssh1_compressing
= TRUE
;
2816 zlib_compress_init();
2817 zlib_decompress_init();
2821 * Start the shell or command.
2823 * Special case: if the first-choice command is an SSH2
2824 * subsystem (hence not usable here) and the second choice
2825 * exists, we fall straight back to that.
2828 char *cmd
= cfg
.remote_cmd_ptr
;
2830 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
2831 cmd
= cfg
.remote_cmd_ptr2
;
2832 ssh_fallback_cmd
= TRUE
;
2835 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2837 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2838 logevent("Started session");
2841 ssh_state
= SSH_STATE_SESSION
;
2845 ssh_special(TS_EOF
);
2847 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
2849 ssh_channels
= newtree234(ssh_channelcmp
);
2853 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2854 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2855 long len
= GET_32BIT(pktin
.body
);
2857 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2858 pktin
.body
+ 4, len
);
2859 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2860 ssh1_stdout_throttling
= 1;
2863 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2864 ssh_state
= SSH_STATE_CLOSED
;
2865 logevent("Received disconnect request");
2867 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2868 /* Remote side is trying to open a channel to talk to our
2869 * X-Server. Give them back a local channel number. */
2870 struct ssh_channel
*c
;
2872 logevent("Received X11 connect request");
2873 /* Refuse if X11 forwarding is disabled. */
2874 if (!ssh_X11_fwd_enabled
) {
2875 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2876 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2877 logevent("Rejected X11 connect request");
2879 c
= smalloc(sizeof(struct ssh_channel
));
2881 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2882 logevent("opening X11 forward connection failed");
2884 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2885 PKT_INT
, GET_32BIT(pktin
.body
),
2889 ("opening X11 forward connection succeeded");
2890 c
->remoteid
= GET_32BIT(pktin
.body
);
2891 c
->localid
= alloc_channel_id();
2893 c
->v
.v1
.throttling
= 0;
2894 c
->type
= CHAN_X11
; /* identify channel type */
2895 add234(ssh_channels
, c
);
2896 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2897 PKT_INT
, c
->remoteid
, PKT_INT
,
2898 c
->localid
, PKT_END
);
2899 logevent("Opened X11 forward channel");
2902 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2903 /* Remote side is trying to open a channel to talk to our
2904 * agent. Give them back a local channel number. */
2905 struct ssh_channel
*c
;
2907 /* Refuse if agent forwarding is disabled. */
2908 if (!ssh_agentfwd_enabled
) {
2909 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2910 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2912 c
= smalloc(sizeof(struct ssh_channel
));
2913 c
->remoteid
= GET_32BIT(pktin
.body
);
2914 c
->localid
= alloc_channel_id();
2916 c
->v
.v1
.throttling
= 0;
2917 c
->type
= CHAN_AGENT
; /* identify channel type */
2918 c
->u
.a
.lensofar
= 0;
2919 add234(ssh_channels
, c
);
2920 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2921 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2924 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
2925 /* Remote side is trying to open a channel to talk to a
2926 * forwarded port. Give them back a local channel number. */
2927 struct ssh_channel
*c
;
2928 struct ssh_rportfwd pf
;
2930 char host
[256], buf
[1024];
2932 c
= smalloc(sizeof(struct ssh_channel
));
2934 hostsize
= GET_32BIT(pktin
.body
+4);
2935 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
2936 if (h
+1 < host
+sizeof(host
))
2941 port
= GET_32BIT(p
);
2943 strcpy(pf
.dhost
, host
);
2946 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
2947 sprintf(buf
, "Rejected remote port open request for %s:%d",
2950 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2951 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2953 sprintf(buf
, "Received remote port open request for %s:%d",
2956 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
2959 sprintf(buf
, "Port open failed: %s", e
);
2962 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2963 PKT_INT
, GET_32BIT(pktin
.body
),
2966 c
->remoteid
= GET_32BIT(pktin
.body
);
2967 c
->localid
= alloc_channel_id();
2969 c
->v
.v1
.throttling
= 0;
2970 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
2971 add234(ssh_channels
, c
);
2972 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2973 PKT_INT
, c
->remoteid
, PKT_INT
,
2974 c
->localid
, PKT_END
);
2975 logevent("Forwarded port opened successfully");
2979 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2980 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2981 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2982 struct ssh_channel
*c
;
2984 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2985 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2986 c
->remoteid
= localid
;
2987 c
->type
= CHAN_SOCKDATA
;
2988 c
->v
.v1
.throttling
= 0;
2989 pfd_confirm(c
->u
.pfd
.s
);
2992 if (c
&& c
->closes
) {
2994 * We have a pending close on this channel,
2995 * which we decided on before the server acked
2996 * the channel open. So now we know the
2997 * remoteid, we can close it again.
2999 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
3003 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3004 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3005 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3006 struct ssh_channel
*c
;
3008 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3009 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3010 logevent("Forwarded connection refused by server");
3011 pfd_close(c
->u
.pfd
.s
);
3012 del234(ssh_channels
, c
);
3016 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3017 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3018 /* Remote side closes a channel. */
3019 unsigned i
= GET_32BIT(pktin
.body
);
3020 struct ssh_channel
*c
;
3021 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3025 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3026 if (!(c
->closes
& closetype
))
3027 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
3029 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3030 logevent("Forwarded X11 connection terminated");
3031 assert(c
->u
.x11
.s
!= NULL
);
3032 x11_close(c
->u
.x11
.s
);
3035 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3036 logevent("Forwarded port closed");
3037 assert(c
->u
.pfd
.s
!= NULL
);
3038 pfd_close(c
->u
.pfd
.s
);
3041 c
->closes
|= closetype
;
3042 if (c
->closes
== 3) {
3043 del234(ssh_channels
, c
);
3047 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3048 /* Data sent down one of our channels. */
3049 int i
= GET_32BIT(pktin
.body
);
3050 int len
= GET_32BIT(pktin
.body
+ 4);
3051 unsigned char *p
= pktin
.body
+ 8;
3052 struct ssh_channel
*c
;
3053 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3058 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3061 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3064 /* Data for an agent message. Buffer it. */
3066 if (c
->u
.a
.lensofar
< 4) {
3067 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3068 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3072 c
->u
.a
.lensofar
+= l
;
3074 if (c
->u
.a
.lensofar
== 4) {
3076 4 + GET_32BIT(c
->u
.a
.msglen
);
3077 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3078 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3080 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3082 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3084 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3088 c
->u
.a
.lensofar
+= l
;
3090 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3091 void *reply
, *sentreply
;
3093 agent_query(c
->u
.a
.message
,
3094 c
->u
.a
.totallen
, &reply
,
3099 /* Fake SSH_AGENT_FAILURE. */
3100 sentreply
= "\0\0\0\1\5";
3103 send_packet(SSH1_MSG_CHANNEL_DATA
,
3104 PKT_INT
, c
->remoteid
,
3106 PKT_DATA
, sentreply
, replylen
,
3110 sfree(c
->u
.a
.message
);
3111 c
->u
.a
.lensofar
= 0;
3114 bufsize
= 0; /* agent channels never back up */
3117 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3118 c
->v
.v1
.throttling
= 1;
3122 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3123 /* may be from EXEC_SHELL on some servers */
3124 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3125 /* may be from EXEC_SHELL on some servers
3126 * if no pty is available or in other odd cases. Ignore */
3127 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3129 ssh_exitcode
= GET_32BIT(pktin
.body
);
3130 sprintf(buf
, "Server sent command exit status %d",
3133 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3135 * In case `helpful' firewalls or proxies tack
3136 * extra human-readable text on the end of the
3137 * session which we might mistake for another
3138 * encrypted packet, we close the session once
3139 * we've sent EXIT_CONFIRMATION.
3141 ssh_state
= SSH_STATE_CLOSED
;
3144 bombout(("Strange packet received: type %d", pktin
.type
));
3149 int len
= min(inlen
, 512);
3150 send_packet(SSH1_CMSG_STDIN_DATA
,
3151 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3162 * Utility routine for decoding comma-separated strings in KEXINIT.
3164 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3166 int needlen
= strlen(needle
);
3169 * Is it at the start of the string?
3171 if (haylen
>= needlen
&& /* haystack is long enough */
3172 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3173 (haylen
== needlen
|| haystack
[needlen
] == ',')
3174 /* either , or EOS follows */
3178 * If not, search for the next comma and resume after that.
3179 * If no comma found, terminate.
3181 while (haylen
> 0 && *haystack
!= ',')
3182 haylen
--, haystack
++;
3185 haylen
--, haystack
++; /* skip over comma itself */
3190 * SSH2 key creation method.
3192 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3196 /* First 20 bytes. */
3199 SHA_Bytes(&s
, H
, 20);
3200 SHA_Bytes(&s
, &chr
, 1);
3201 SHA_Bytes(&s
, sessid
, 20);
3202 SHA_Final(&s
, keyspace
);
3203 /* Next 20 bytes. */
3206 SHA_Bytes(&s
, H
, 20);
3207 SHA_Bytes(&s
, keyspace
, 20);
3208 SHA_Final(&s
, keyspace
+ 20);
3212 * Handle the SSH2 transport layer.
3214 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3216 static int i
, j
, len
, nbits
, pbits
, warn
;
3218 static Bignum p
, g
, e
, f
, K
;
3219 static int kex_init_value
, kex_reply_value
;
3220 static const struct ssh_mac
**maclist
;
3222 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3223 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3224 static const struct ssh_mac
*csmac_tobe
= NULL
;
3225 static const struct ssh_mac
*scmac_tobe
= NULL
;
3226 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3227 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3228 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3229 static int hostkeylen
, siglen
;
3230 static void *hkey
; /* actual host key */
3231 static unsigned char exchange_hash
[20];
3232 static unsigned char keyspace
[40];
3233 static int n_preferred_ciphers
;
3234 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3235 static const struct ssh_compress
*preferred_comp
;
3236 static int cipherstr_started
;
3237 static int first_kex
;
3244 * Set up the preferred ciphers. (NULL => warn below here)
3246 n_preferred_ciphers
= 0;
3247 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3248 switch (cfg
.ssh_cipherlist
[i
]) {
3249 case CIPHER_BLOWFISH
:
3250 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3251 n_preferred_ciphers
++;
3254 if (cfg
.ssh2_des_cbc
) {
3255 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3256 n_preferred_ciphers
++;
3260 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3261 n_preferred_ciphers
++;
3264 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3265 n_preferred_ciphers
++;
3268 /* Flag for later. Don't bother if it's the last in
3270 if (i
< CIPHER_MAX
- 1) {
3271 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3272 n_preferred_ciphers
++;
3279 * Set up preferred compression.
3281 if (cfg
.compression
)
3282 preferred_comp
= &ssh_zlib
;
3284 preferred_comp
= &ssh_comp_none
;
3287 * Be prepared to work around the buggy MAC problem.
3289 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3290 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3292 maclist
= macs
, nmacs
= lenof(macs
);
3296 * Construct and send our key exchange packet.
3298 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3299 for (i
= 0; i
< 16; i
++)
3300 ssh2_pkt_addbyte((unsigned char) random_byte());
3301 /* List key exchange algorithms. */
3302 ssh2_pkt_addstring_start();
3303 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3304 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3305 if (i
< lenof(kex_algs
) - 1)
3306 ssh2_pkt_addstring_str(",");
3308 /* List server host key algorithms. */
3309 ssh2_pkt_addstring_start();
3310 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3311 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3312 if (i
< lenof(hostkey_algs
) - 1)
3313 ssh2_pkt_addstring_str(",");
3315 /* List client->server encryption algorithms. */
3316 ssh2_pkt_addstring_start();
3317 cipherstr_started
= 0;
3318 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3319 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3320 if (!c
) continue; /* warning flag */
3321 for (j
= 0; j
< c
->nciphers
; j
++) {
3322 if (cipherstr_started
)
3323 ssh2_pkt_addstring_str(",");
3324 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3325 cipherstr_started
= 1;
3328 /* List server->client encryption algorithms. */
3329 ssh2_pkt_addstring_start();
3330 cipherstr_started
= 0;
3331 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3332 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3333 if (!c
) continue; /* warning flag */
3334 for (j
= 0; j
< c
->nciphers
; j
++) {
3335 if (cipherstr_started
)
3336 ssh2_pkt_addstring_str(",");
3337 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3338 cipherstr_started
= 1;
3341 /* List client->server MAC algorithms. */
3342 ssh2_pkt_addstring_start();
3343 for (i
= 0; i
< nmacs
; i
++) {
3344 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3346 ssh2_pkt_addstring_str(",");
3348 /* List server->client MAC algorithms. */
3349 ssh2_pkt_addstring_start();
3350 for (i
= 0; i
< nmacs
; i
++) {
3351 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3353 ssh2_pkt_addstring_str(",");
3355 /* List client->server compression algorithms. */
3356 ssh2_pkt_addstring_start();
3357 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3358 const struct ssh_compress
*c
=
3359 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3360 ssh2_pkt_addstring_str(c
->name
);
3361 if (i
< lenof(compressions
))
3362 ssh2_pkt_addstring_str(",");
3364 /* List server->client compression algorithms. */
3365 ssh2_pkt_addstring_start();
3366 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3367 const struct ssh_compress
*c
=
3368 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3369 ssh2_pkt_addstring_str(c
->name
);
3370 if (i
< lenof(compressions
))
3371 ssh2_pkt_addstring_str(",");
3373 /* List client->server languages. Empty list. */
3374 ssh2_pkt_addstring_start();
3375 /* List server->client languages. Empty list. */
3376 ssh2_pkt_addstring_start();
3377 /* First KEX packet does _not_ follow, because we're not that brave. */
3378 ssh2_pkt_addbool(FALSE
);
3380 ssh2_pkt_adduint32(0);
3382 exhash
= exhashbase
;
3383 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3389 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3392 * Now examine the other side's KEXINIT to see what we're up
3395 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3396 bombout(("expected key exchange packet from server"));
3401 cscipher_tobe
= NULL
;
3402 sccipher_tobe
= NULL
;
3407 pktin
.savedpos
+= 16; /* skip garbage cookie */
3408 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3409 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3410 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3415 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3416 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3417 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3418 hostkey
= hostkey_algs
[i
];
3422 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3424 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3425 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3429 for (j
= 0; j
< c
->nciphers
; j
++) {
3430 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3431 cscipher_tobe
= c
->list
[j
];
3436 if (cscipher_tobe
) {
3438 askcipher(cscipher_tobe
->name
, 1);
3442 if (!cscipher_tobe
) {
3443 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3447 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3449 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3450 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3454 for (j
= 0; j
< c
->nciphers
; j
++) {
3455 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3456 sccipher_tobe
= c
->list
[j
];
3461 if (sccipher_tobe
) {
3463 askcipher(sccipher_tobe
->name
, 2);
3467 if (!sccipher_tobe
) {
3468 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3472 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3473 for (i
= 0; i
< nmacs
; i
++) {
3474 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3475 csmac_tobe
= maclist
[i
];
3479 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3480 for (i
= 0; i
< nmacs
; i
++) {
3481 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3482 scmac_tobe
= maclist
[i
];
3486 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3487 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3488 const struct ssh_compress
*c
=
3489 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3490 if (in_commasep_string(c
->name
, str
, len
)) {
3495 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3496 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3497 const struct ssh_compress
*c
=
3498 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3499 if (in_commasep_string(c
->name
, str
, len
)) {
3506 * Work out the number of bits of key we will need from the key
3507 * exchange. We start with the maximum key length of either
3513 csbits
= cscipher_tobe
->keylen
;
3514 scbits
= sccipher_tobe
->keylen
;
3515 nbits
= (csbits
> scbits ? csbits
: scbits
);
3517 /* The keys only have 160-bit entropy, since they're based on
3518 * a SHA-1 hash. So cap the key size at 160 bits. */
3523 * If we're doing Diffie-Hellman group exchange, start by
3524 * requesting a group.
3526 if (kex
== &ssh_diffiehellman_gex
) {
3527 logevent("Doing Diffie-Hellman group exchange");
3528 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3530 * Work out how big a DH group we will need to allow that
3533 pbits
= 512 << ((nbits
- 1) / 64);
3534 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3535 ssh2_pkt_adduint32(pbits
);
3539 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3540 bombout(("expected key exchange group packet from server"));
3543 p
= ssh2_pkt_getmp();
3544 g
= ssh2_pkt_getmp();
3545 dh_setup_group(p
, g
);
3546 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3547 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3549 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3551 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3552 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3555 logevent("Doing Diffie-Hellman key exchange");
3557 * Now generate and send e for Diffie-Hellman.
3559 e
= dh_create_e(nbits
* 2);
3560 ssh2_pkt_init(kex_init_value
);
3565 if (pktin
.type
!= kex_reply_value
) {
3566 bombout(("expected key exchange reply packet from server"));
3569 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3570 f
= ssh2_pkt_getmp();
3571 ssh2_pkt_getstring(&sigdata
, &siglen
);
3575 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3576 if (kex
== &ssh_diffiehellman_gex
) {
3577 sha_uint32(&exhash
, pbits
);
3578 sha_mpint(&exhash
, p
);
3579 sha_mpint(&exhash
, g
);
3581 sha_mpint(&exhash
, e
);
3582 sha_mpint(&exhash
, f
);
3583 sha_mpint(&exhash
, K
);
3584 SHA_Final(&exhash
, exchange_hash
);
3589 debug(("Exchange hash is:\n"));
3590 dmemdump(exchange_hash
, 20);
3593 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3595 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3596 bombout(("Server's host key did not match the signature supplied"));
3601 * Authenticate remote host: verify host key. (We've already
3602 * checked the signature of the exchange hash.)
3604 keystr
= hostkey
->fmtkey(hkey
);
3605 fingerprint
= hostkey
->fingerprint(hkey
);
3606 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3607 keystr
, fingerprint
);
3608 if (first_kex
) { /* don't bother logging this in rekeys */
3609 logevent("Host key fingerprint is:");
3610 logevent(fingerprint
);
3614 hostkey
->freekey(hkey
);
3617 * Send SSH2_MSG_NEWKEYS.
3619 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3623 * Expect SSH2_MSG_NEWKEYS from server.
3626 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3627 bombout(("expected new-keys packet from server"));
3632 * Create and initialise session keys.
3634 cscipher
= cscipher_tobe
;
3635 sccipher
= sccipher_tobe
;
3638 cscomp
= cscomp_tobe
;
3639 sccomp
= sccomp_tobe
;
3640 cscomp
->compress_init();
3641 sccomp
->decompress_init();
3643 * Set IVs after keys. Here we use the exchange hash from the
3644 * _first_ key exchange.
3647 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3648 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3649 cscipher
->setcskey(keyspace
);
3650 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3651 sccipher
->setsckey(keyspace
);
3652 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3653 cscipher
->setcsiv(keyspace
);
3654 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3655 sccipher
->setsciv(keyspace
);
3656 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3657 csmac
->setcskey(keyspace
);
3658 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3659 scmac
->setsckey(keyspace
);
3662 * If this is the first key exchange phase, we must pass the
3663 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3664 * wants to see it but because it will need time to initialise
3665 * itself before it sees an actual packet. In subsequent key
3666 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3667 * it would only confuse the layer above.
3675 * Now we're encrypting. Begin returning 1 to the protocol main
3676 * function so that other things can run on top of the
3677 * transport. If we ever see a KEXINIT, we must go back to the
3680 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3683 logevent("Server initiated key re-exchange");
3684 goto begin_key_exchange
;
3690 * Add data to an SSH2 channel output buffer.
3692 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3695 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3699 * Attempt to send data on an SSH2 channel.
3701 static int ssh2_try_send(struct ssh_channel
*c
)
3703 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3706 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3707 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3708 len
= c
->v
.v2
.remwindow
;
3709 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3710 len
= c
->v
.v2
.remmaxpkt
;
3711 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3712 ssh2_pkt_adduint32(c
->remoteid
);
3713 ssh2_pkt_addstring_start();
3714 ssh2_pkt_addstring_data(data
, len
);
3716 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3717 c
->v
.v2
.remwindow
-= len
;
3721 * After having sent as much data as we can, return the amount
3724 return bufchain_size(&c
->v
.v2
.outbuffer
);
3728 * Potentially enlarge the window on an SSH2 channel.
3730 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3732 if (newwin
> c
->v
.v2
.locwindow
) {
3733 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3734 ssh2_pkt_adduint32(c
->remoteid
);
3735 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3737 c
->v
.v2
.locwindow
= newwin
;
3742 * Handle the SSH2 userauth and connection layers.
3744 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3747 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3749 AUTH_KEYBOARD_INTERACTIVE
3753 AUTH_TYPE_PUBLICKEY
,
3754 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3755 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3757 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3758 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3760 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3761 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3762 static int kbd_inter_running
;
3763 static int we_are_in
;
3764 static int num_prompts
, echo
;
3765 static char username
[100];
3766 static char pwprompt
[200];
3767 static char password
[100];
3768 static void *publickey_blob
;
3769 static int publickey_bloblen
;
3774 * Request userauth protocol, and await a response to it.
3776 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3777 ssh2_pkt_addstring("ssh-userauth");
3779 crWaitUntilV(ispkt
);
3780 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3781 bombout(("Server refused user authentication protocol"));
3786 * We repeat this whole loop, including the username prompt,
3787 * until we manage a successful authentication. If the user
3788 * types the wrong _password_, they are sent back to the
3789 * beginning to try another username. (If they specify a
3790 * username in the config, they are never asked, even if they
3791 * do give a wrong password.)
3793 * I think this best serves the needs of
3795 * - the people who have no configuration, no keys, and just
3796 * want to try repeated (username,password) pairs until they
3797 * type both correctly
3799 * - people who have keys and configuration but occasionally
3800 * need to fall back to passwords
3802 * - people with a key held in Pageant, who might not have
3803 * logged in to a particular machine before; so they want to
3804 * type a username, and then _either_ their key will be
3805 * accepted, _or_ they will type a password. If they mistype
3806 * the username they will want to be able to get back and
3818 if (*username
&& !cfg
.change_username
) {
3820 * We got a username last time round this loop, and
3821 * with change_username turned off we don't try to get
3824 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
3826 if (!ssh_get_line("login as: ",
3827 username
, sizeof(username
), FALSE
)) {
3829 * get_line failed to get a username.
3832 logevent("No username provided. Abandoning session.");
3833 ssh_state
= SSH_STATE_CLOSED
;
3837 c_write_str("login as: ");
3840 crWaitUntilV(!ispkt
);
3842 switch (c
= *in
++) {
3851 c_write_str("\b \b");
3858 c_write_str("\b \b");
3868 if (((c
>= ' ' && c
<= '~') ||
3869 ((unsigned char) c
>= 160))
3870 && pos
< sizeof(username
)-1) {
3871 username
[pos
++] = c
;
3878 c_write_str("\r\n");
3879 username
[strcspn(username
, "\n\r")] = '\0';
3882 strncpy(username
, cfg
.username
, 99);
3883 username
[99] = '\0';
3884 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3885 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3891 * Send an authentication request using method "none": (a)
3892 * just in case it succeeds, and (b) so that we know what
3893 * authentication methods we can usefully try next.
3895 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
3897 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3898 ssh2_pkt_addstring(username
);
3899 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3900 ssh2_pkt_addstring("none"); /* method */
3902 type
= AUTH_TYPE_NONE
;
3906 tried_pubkey_config
= FALSE
;
3907 tried_agent
= FALSE
;
3908 tried_keyb_inter
= FALSE
;
3909 kbd_inter_running
= FALSE
;
3910 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
3912 publickey_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
3913 &publickey_bloblen
);
3915 publickey_blob
= NULL
;
3919 * Wait for the result of the last authentication request.
3922 crWaitUntilV(ispkt
);
3923 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
3927 * Don't show the banner if we're operating in
3928 * non-verbose non-interactive mode. (It's probably
3929 * a script, which means nobody will read the
3930 * banner _anyway_, and moreover the printing of
3931 * the banner will screw up processing on the
3932 * output of (say) plink.)
3934 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
3935 ssh2_pkt_getstring(&banner
, &size
);
3937 c_write_untrusted(banner
, size
);
3939 crWaitUntilV(ispkt
);
3941 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
3942 logevent("Access granted");
3947 if (kbd_inter_running
&&
3948 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
3950 * This is a further prompt in keyboard-interactive
3951 * authentication. Do nothing.
3953 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
3954 bombout(("Strange packet received during authentication: type %d",
3962 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3963 * we can look at the string in it and know what we can
3964 * helpfully try next.
3966 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
3969 ssh2_pkt_getstring(&methods
, &methlen
);
3970 kbd_inter_running
= FALSE
;
3971 if (!ssh2_pkt_getbool()) {
3973 * We have received an unequivocal Access
3974 * Denied. This can translate to a variety of
3977 * - if we'd just tried "none" authentication,
3978 * it's not worth printing anything at all
3980 * - if we'd just tried a public key _offer_,
3981 * the message should be "Server refused our
3982 * key" (or no message at all if the key
3983 * came from Pageant)
3985 * - if we'd just tried anything else, the
3986 * message really should be "Access denied".
3988 * Additionally, if we'd just tried password
3989 * authentication, we should break out of this
3990 * whole loop so as to go back to the username
3993 if (type
== AUTH_TYPE_NONE
) {
3995 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
3996 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
3997 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
3998 c_write_str("Server refused our key\r\n");
3999 logevent("Server refused public key");
4000 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4001 /* server declined keyboard-interactive; ignore */
4003 c_write_str("Access denied\r\n");
4004 logevent("Access denied");
4005 if (type
== AUTH_TYPE_PASSWORD
) {
4011 c_write_str("Further authentication required\r\n");
4012 logevent("Further authentication required");
4016 in_commasep_string("publickey", methods
, methlen
);
4018 in_commasep_string("password", methods
, methlen
);
4019 can_keyb_inter
= cfg
.try_ki_auth
&&
4020 in_commasep_string("keyboard-interactive", methods
, methlen
);
4024 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4026 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
4028 * Attempt public-key authentication using Pageant.
4030 static unsigned char request
[5], *response
, *p
;
4031 static int responselen
;
4032 static int i
, nkeys
;
4033 static int authed
= FALSE
;
4036 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4040 logevent("Pageant is running. Requesting keys.");
4042 /* Request the keys held by the agent. */
4043 PUT_32BIT(request
, 1);
4044 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4045 agent_query(request
, 5, &r
, &responselen
);
4046 response
= (unsigned char *) r
;
4047 if (response
&& responselen
>= 5 &&
4048 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4050 nkeys
= GET_32BIT(p
);
4054 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
4057 for (i
= 0; i
< nkeys
; i
++) {
4058 static char *pkblob
, *alg
, *commentp
;
4059 static int pklen
, alglen
, commentlen
;
4060 static int siglen
, retlen
, len
;
4061 static char *q
, *agentreq
, *ret
;
4066 sprintf(buf
, "Trying Pageant key #%d", i
);
4069 pklen
= GET_32BIT(p
);
4071 if (publickey_blob
&&
4072 pklen
== publickey_bloblen
&&
4073 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
4074 logevent("This key matches configured key file");
4075 tried_pubkey_config
= 1;
4079 alglen
= GET_32BIT(pkblob
);
4081 commentlen
= GET_32BIT(p
);
4085 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4086 ssh2_pkt_addstring(username
);
4087 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4088 ssh2_pkt_addstring("publickey"); /* method */
4089 ssh2_pkt_addbool(FALSE
); /* no signature included */
4090 ssh2_pkt_addstring_start();
4091 ssh2_pkt_addstring_data(alg
, alglen
);
4092 ssh2_pkt_addstring_start();
4093 ssh2_pkt_addstring_data(pkblob
, pklen
);
4096 crWaitUntilV(ispkt
);
4097 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4098 logevent("Key refused");
4102 if (flags
& FLAG_VERBOSE
) {
4104 ("Authenticating with public key \"");
4105 c_write(commentp
, commentlen
);
4106 c_write_str("\" from agent\r\n");
4110 * Server is willing to accept the key.
4111 * Construct a SIGN_REQUEST.
4113 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4114 ssh2_pkt_addstring(username
);
4115 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4116 ssh2_pkt_addstring("publickey"); /* method */
4117 ssh2_pkt_addbool(TRUE
);
4118 ssh2_pkt_addstring_start();
4119 ssh2_pkt_addstring_data(alg
, alglen
);
4120 ssh2_pkt_addstring_start();
4121 ssh2_pkt_addstring_data(pkblob
, pklen
);
4123 siglen
= pktout
.length
- 5 + 4 + 20;
4124 len
= 1; /* message type */
4125 len
+= 4 + pklen
; /* key blob */
4126 len
+= 4 + siglen
; /* data to sign */
4127 len
+= 4; /* flags */
4128 agentreq
= smalloc(4 + len
);
4129 PUT_32BIT(agentreq
, len
);
4131 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4132 PUT_32BIT(q
, pklen
);
4134 memcpy(q
, pkblob
, pklen
);
4136 PUT_32BIT(q
, siglen
);
4138 /* Now the data to be signed... */
4141 memcpy(q
, ssh2_session_id
, 20);
4143 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4144 q
+= pktout
.length
- 5;
4145 /* And finally the (zero) flags word. */
4147 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4151 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4152 logevent("Sending Pageant's response");
4153 ssh2_pkt_addstring_start();
4154 ssh2_pkt_addstring_data(ret
+ 9,
4162 ("Pageant failed to answer challenge");
4172 if (!method
&& can_pubkey
&& *cfg
.keyfile
4173 && !tried_pubkey_config
) {
4174 unsigned char *pub_blob
;
4175 char *algorithm
, *comment
;
4178 tried_pubkey_config
= TRUE
;
4180 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4183 * Try the public key supplied in the configuration.
4185 * First, offer the public blob to see if the server is
4186 * willing to accept it.
4188 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4191 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4192 ssh2_pkt_addstring(username
);
4193 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4194 ssh2_pkt_addstring("publickey"); /* method */
4195 ssh2_pkt_addbool(FALSE
); /* no signature included */
4196 ssh2_pkt_addstring(algorithm
);
4197 ssh2_pkt_addstring_start();
4198 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4200 logevent("Offered public key"); /* FIXME */
4202 crWaitUntilV(ispkt
);
4203 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4205 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4206 continue; /* key refused; give up on it */
4209 logevent("Offer of public key accepted");
4211 * Actually attempt a serious authentication using
4214 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4216 "Passphrase for key \"%.100s\": ",
4222 c_write_str("Authenticating with public key \"");
4223 c_write_str(comment
);
4224 c_write_str("\"\r\n");
4225 method
= AUTH_PUBLICKEY_FILE
;
4229 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4230 method
= AUTH_KEYBOARD_INTERACTIVE
;
4231 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4232 tried_keyb_inter
= TRUE
;
4234 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4236 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4237 ssh2_pkt_addstring(username
);
4238 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4239 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4240 ssh2_pkt_addstring(""); /* lang */
4241 ssh2_pkt_addstring("");
4244 crWaitUntilV(ispkt
);
4245 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4246 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4248 logevent("Keyboard-interactive authentication refused");
4249 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4253 kbd_inter_running
= TRUE
;
4256 if (kbd_inter_running
) {
4257 method
= AUTH_KEYBOARD_INTERACTIVE
;
4258 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4259 tried_keyb_inter
= TRUE
;
4261 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4263 /* We've got packet with that "interactive" info
4264 dump banners, and set its prompt as ours */
4266 char *name
, *inst
, *lang
, *prompt
;
4267 int name_len
, inst_len
, lang_len
, prompt_len
;
4268 ssh2_pkt_getstring(&name
, &name_len
);
4269 ssh2_pkt_getstring(&inst
, &inst_len
);
4270 ssh2_pkt_getstring(&lang
, &lang_len
);
4272 c_write_untrusted(name
, name_len
);
4274 c_write_untrusted(inst
, inst_len
);
4275 num_prompts
= ssh2_pkt_getuint32();
4277 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4278 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4279 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4280 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4283 echo
= ssh2_pkt_getbool();
4287 if (!method
&& can_passwd
) {
4288 method
= AUTH_PASSWORD
;
4289 ssh_pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4290 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4297 if (!ssh_get_line(pwprompt
, password
,
4298 sizeof(password
), TRUE
)) {
4300 * get_line failed to get a password (for
4301 * example because one was supplied on the
4302 * command line which has already failed to
4305 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4306 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4308 ("No more passwords available to try");
4309 ssh2_pkt_addstring("en"); /* language tag */
4311 connection_fatal("Unable to authenticate");
4312 ssh_state
= SSH_STATE_CLOSED
;
4319 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4324 crWaitUntilV(!ispkt
);
4326 switch (c
= *in
++) {
4347 if (pos
< sizeof(password
)-1)
4348 password
[pos
++] = c
;
4352 c_write_str("\r\n");
4356 if (method
== AUTH_PUBLICKEY_FILE
) {
4358 * We have our passphrase. Now try the actual authentication.
4360 struct ssh2_userkey
*key
;
4362 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4363 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4364 if (key
== SSH2_WRONG_PASSPHRASE
) {
4365 c_write_str("Wrong passphrase\r\n");
4366 tried_pubkey_config
= FALSE
;
4368 c_write_str("Unable to load private key\r\n");
4369 tried_pubkey_config
= TRUE
;
4371 /* Send a spurious AUTH_NONE to return to the top. */
4372 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4373 ssh2_pkt_addstring(username
);
4374 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4375 ssh2_pkt_addstring("none"); /* method */
4377 type
= AUTH_TYPE_NONE
;
4379 unsigned char *blob
, *sigdata
;
4380 int blob_len
, sigdata_len
;
4383 * We have loaded the private key and the server
4384 * has announced that it's willing to accept it.
4385 * Hallelujah. Generate a signature and send it.
4387 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4388 ssh2_pkt_addstring(username
);
4389 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4390 ssh2_pkt_addstring("publickey"); /* method */
4391 ssh2_pkt_addbool(TRUE
);
4392 ssh2_pkt_addstring(key
->alg
->name
);
4393 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4394 ssh2_pkt_addstring_start();
4395 ssh2_pkt_addstring_data(blob
, blob_len
);
4399 * The data to be signed is:
4403 * followed by everything so far placed in the
4406 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4407 sigdata
= smalloc(sigdata_len
);
4408 PUT_32BIT(sigdata
, 20);
4409 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4410 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4413 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4415 ssh2_pkt_addstring_start();
4416 ssh2_pkt_addstring_data(blob
, blob_len
);
4421 type
= AUTH_TYPE_PUBLICKEY
;
4423 } else if (method
== AUTH_PASSWORD
) {
4425 * We send the password packet lumped tightly together with
4426 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4427 * string long enough to make the total length of the two
4428 * packets constant. This should ensure that a passive
4429 * listener doing traffic analyis can't work out the length
4432 * For this to work, we need an assumption about the
4433 * maximum length of the password packet. I think 256 is
4434 * pretty conservative. Anyone using a password longer than
4435 * that probably doesn't have much to worry about from
4436 * people who find out how long their password is!
4438 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4439 ssh2_pkt_addstring(username
);
4440 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4441 ssh2_pkt_addstring("password");
4442 ssh2_pkt_addbool(FALSE
);
4443 ssh2_pkt_addstring(password
);
4446 * We'll include a string that's an exact multiple of the
4447 * cipher block size. If the cipher is NULL for some
4448 * reason, we don't do this trick at all because we gain
4454 stringlen
= (256 - deferred_len
);
4455 stringlen
+= cscipher
->blksize
- 1;
4456 stringlen
-= (stringlen
% cscipher
->blksize
);
4459 * Temporarily disable actual compression,
4460 * so we can guarantee to get this string
4461 * exactly the length we want it. The
4462 * compression-disabling routine should
4463 * return an integer indicating how many
4464 * bytes we should adjust our string length
4467 stringlen
-= cscomp
->disable_compression();
4469 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4470 ssh2_pkt_addstring_start();
4471 for (i
= 0; i
< stringlen
; i
++) {
4472 char c
= (char) random_byte();
4473 ssh2_pkt_addstring_data(&c
, 1);
4477 ssh_pkt_defersend();
4478 logevent("Sent password");
4479 type
= AUTH_TYPE_PASSWORD
;
4480 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4481 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4482 ssh2_pkt_adduint32(num_prompts
);
4483 ssh2_pkt_addstring(password
);
4484 memset(password
, 0, sizeof(password
));
4486 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4489 ("No supported authentication methods left to try!\r\n");
4491 ("No supported authentications offered. Disconnecting");
4492 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4493 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4495 ("No supported authentication methods available");
4496 ssh2_pkt_addstring("en"); /* language tag */
4498 ssh_state
= SSH_STATE_CLOSED
;
4502 } while (!we_are_in
);
4505 * Now we're authenticated for the connection protocol. The
4506 * connection protocol will automatically have started at this
4507 * point; there's no need to send SERVICE_REQUEST.
4511 * So now create a channel with a session in it.
4513 ssh_channels
= newtree234(ssh_channelcmp
);
4514 mainchan
= smalloc(sizeof(struct ssh_channel
));
4515 mainchan
->localid
= alloc_channel_id();
4516 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4517 ssh2_pkt_addstring("session");
4518 ssh2_pkt_adduint32(mainchan
->localid
);
4519 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4520 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4521 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4523 crWaitUntilV(ispkt
);
4524 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4525 bombout(("Server refused to open a session"));
4527 /* FIXME: error data comes back in FAILURE packet */
4529 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4530 bombout(("Server's channel confirmation cited wrong channel"));
4533 mainchan
->remoteid
= ssh2_pkt_getuint32();
4534 mainchan
->type
= CHAN_MAINSESSION
;
4535 mainchan
->closes
= 0;
4536 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4537 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4538 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4539 add234(ssh_channels
, mainchan
);
4540 logevent("Opened channel for session");
4543 * Potentially enable X11 forwarding.
4545 if (cfg
.x11_forward
) {
4546 char proto
[20], data
[64];
4547 logevent("Requesting X11 forwarding");
4548 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4549 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4550 ssh2_pkt_adduint32(mainchan
->remoteid
);
4551 ssh2_pkt_addstring("x11-req");
4552 ssh2_pkt_addbool(1); /* want reply */
4553 ssh2_pkt_addbool(0); /* many connections */
4554 ssh2_pkt_addstring(proto
);
4555 ssh2_pkt_addstring(data
);
4556 ssh2_pkt_adduint32(0); /* screen number */
4560 crWaitUntilV(ispkt
);
4561 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4562 unsigned i
= ssh2_pkt_getuint32();
4563 struct ssh_channel
*c
;
4564 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4566 continue; /* nonexistent channel */
4567 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4569 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4571 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4572 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4573 bombout(("Unexpected response to X11 forwarding request:"
4574 " packet type %d", pktin
.type
));
4577 logevent("X11 forwarding refused");
4579 logevent("X11 forwarding enabled");
4580 ssh_X11_fwd_enabled
= TRUE
;
4585 * Enable port forwardings.
4588 static char *e
; /* preserve across crReturn */
4592 char sports
[256], dports
[256], host
[256];
4595 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4596 /* Add port forwardings. */
4601 while (*e
&& *e
!= '\t')
4607 while (*e
&& *e
!= ':')
4617 dport
= atoi(dports
);
4618 sport
= atoi(sports
);
4619 if (sport
&& dport
) {
4621 pfd_addforward(host
, dport
, sport
);
4622 sprintf(buf
, "Local port %d forwarding to %s:%d",
4623 sport
, host
, dport
);
4626 struct ssh_rportfwd
*pf
;
4627 pf
= smalloc(sizeof(*pf
));
4628 strcpy(pf
->dhost
, host
);
4631 if (add234(ssh_rportfwds
, pf
) != pf
) {
4633 "Duplicate remote port forwarding to %s:%d",
4638 sprintf(buf
, "Requesting remote port %d (forwarded to %s:%d)",
4639 sport
, host
, dport
);
4641 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4642 ssh2_pkt_addstring("tcpip-forward");
4643 ssh2_pkt_addbool(1);/* want reply */
4644 if (cfg
.rport_acceptall
)
4645 ssh2_pkt_addstring("0.0.0.0");
4647 ssh2_pkt_addstring("127.0.0.1");
4648 ssh2_pkt_adduint32(sport
);
4652 crWaitUntilV(ispkt
);
4653 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4654 unsigned i
= ssh2_pkt_getuint32();
4655 struct ssh_channel
*c
;
4656 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4658 continue;/* nonexistent channel */
4659 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4661 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4663 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4664 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4665 bombout(("Unexpected response to port "
4666 "forwarding request: packet type %d",
4670 logevent("Server refused this port forwarding");
4672 logevent("Remote port forwarding enabled");
4681 * Potentially enable agent forwarding.
4683 if (cfg
.agentfwd
&& agent_exists()) {
4684 logevent("Requesting OpenSSH-style agent forwarding");
4685 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4686 ssh2_pkt_adduint32(mainchan
->remoteid
);
4687 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4688 ssh2_pkt_addbool(1); /* want reply */
4692 crWaitUntilV(ispkt
);
4693 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4694 unsigned i
= ssh2_pkt_getuint32();
4695 struct ssh_channel
*c
;
4696 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4698 continue; /* nonexistent channel */
4699 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4701 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4703 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4704 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4705 bombout(("Unexpected response to agent forwarding request:"
4706 " packet type %d", pktin
.type
));
4709 logevent("Agent forwarding refused");
4711 logevent("Agent forwarding enabled");
4712 ssh_agentfwd_enabled
= TRUE
;
4717 * Now allocate a pty for the session.
4720 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4721 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4722 ssh2_pkt_addstring("pty-req");
4723 ssh2_pkt_addbool(1); /* want reply */
4724 ssh2_pkt_addstring(cfg
.termtype
);
4725 ssh2_pkt_adduint32(cols
);
4726 ssh2_pkt_adduint32(rows
);
4727 ssh2_pkt_adduint32(0); /* pixel width */
4728 ssh2_pkt_adduint32(0); /* pixel height */
4729 ssh2_pkt_addstring_start();
4730 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4732 ssh_state
= SSH_STATE_INTERMED
;
4735 crWaitUntilV(ispkt
);
4736 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4737 unsigned i
= ssh2_pkt_getuint32();
4738 struct ssh_channel
*c
;
4739 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4741 continue; /* nonexistent channel */
4742 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4744 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4746 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4747 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4748 bombout(("Unexpected response to pty request:"
4749 " packet type %d", pktin
.type
));
4752 c_write_str("Server refused to allocate pty\r\n");
4753 ssh_editing
= ssh_echoing
= 1;
4755 logevent("Allocated pty");
4758 ssh_editing
= ssh_echoing
= 1;
4762 * Start a shell or a remote command. We may have to attempt
4763 * this twice if the config data has provided a second choice
4770 if (ssh_fallback_cmd
) {
4771 subsys
= cfg
.ssh_subsys2
;
4772 cmd
= cfg
.remote_cmd_ptr2
;
4774 subsys
= cfg
.ssh_subsys
;
4775 cmd
= cfg
.remote_cmd_ptr
;
4778 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4779 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4781 ssh2_pkt_addstring("subsystem");
4782 ssh2_pkt_addbool(1); /* want reply */
4783 ssh2_pkt_addstring(cmd
);
4785 ssh2_pkt_addstring("exec");
4786 ssh2_pkt_addbool(1); /* want reply */
4787 ssh2_pkt_addstring(cmd
);
4789 ssh2_pkt_addstring("shell");
4790 ssh2_pkt_addbool(1); /* want reply */
4794 crWaitUntilV(ispkt
);
4795 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4796 unsigned i
= ssh2_pkt_getuint32();
4797 struct ssh_channel
*c
;
4798 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4800 continue; /* nonexistent channel */
4801 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4803 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4804 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4805 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4806 bombout(("Unexpected response to shell/command request:"
4807 " packet type %d", pktin
.type
));
4811 * We failed to start the command. If this is the
4812 * fallback command, we really are finished; if it's
4813 * not, and if the fallback command exists, try falling
4814 * back to it before complaining.
4816 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
4817 logevent("Primary command failed; attempting fallback");
4818 ssh_fallback_cmd
= TRUE
;
4821 bombout(("Server refused to start a shell/command"));
4824 logevent("Started a shell/command");
4829 ssh_state
= SSH_STATE_SESSION
;
4833 ssh_special(TS_EOF
);
4838 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
4841 static int try_send
;
4845 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
4846 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
4849 unsigned i
= ssh2_pkt_getuint32();
4850 struct ssh_channel
*c
;
4851 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4853 continue; /* nonexistent channel */
4854 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
4855 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
4856 continue; /* extended but not stderr */
4857 ssh2_pkt_getstring(&data
, &length
);
4860 c
->v
.v2
.locwindow
-= length
;
4862 case CHAN_MAINSESSION
:
4864 from_backend(pktin
.type
==
4865 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
4869 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
4872 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
4875 while (length
> 0) {
4876 if (c
->u
.a
.lensofar
< 4) {
4877 int l
= min(4 - c
->u
.a
.lensofar
, length
);
4878 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
4882 c
->u
.a
.lensofar
+= l
;
4884 if (c
->u
.a
.lensofar
== 4) {
4886 4 + GET_32BIT(c
->u
.a
.msglen
);
4887 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
4888 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
4890 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
4892 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
4894 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
4898 c
->u
.a
.lensofar
+= l
;
4900 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
4901 void *reply
, *sentreply
;
4903 agent_query(c
->u
.a
.message
,
4904 c
->u
.a
.totallen
, &reply
,
4909 /* Fake SSH_AGENT_FAILURE. */
4910 sentreply
= "\0\0\0\1\5";
4913 ssh2_add_channel_data(c
, sentreply
,
4918 sfree(c
->u
.a
.message
);
4919 c
->u
.a
.lensofar
= 0;
4926 * If we are not buffering too much data,
4927 * enlarge the window again at the remote side.
4929 if (bufsize
< OUR_V2_WINSIZE
)
4930 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
4932 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
4933 ssh_state
= SSH_STATE_CLOSED
;
4934 logevent("Received disconnect message");
4936 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
4937 unsigned i
= ssh2_pkt_getuint32();
4938 struct ssh_channel
*c
;
4940 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4942 continue; /* nonexistent channel */
4944 if (c
->type
== CHAN_X11
) {
4946 * Remote EOF on an X11 channel means we should
4947 * wrap up and close the channel ourselves.
4949 x11_close(c
->u
.x11
.s
);
4951 } else if (c
->type
== CHAN_AGENT
) {
4953 } else if (c
->type
== CHAN_SOCKDATA
) {
4954 pfd_close(c
->u
.pfd
.s
);
4957 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
4958 unsigned i
= ssh2_pkt_getuint32();
4959 struct ssh_channel
*c
;
4961 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4963 continue; /* nonexistent channel */
4964 /* Do pre-close processing on the channel. */
4966 case CHAN_MAINSESSION
:
4967 break; /* nothing to see here, move along */
4969 if (c
->u
.x11
.s
!= NULL
)
4970 x11_close(c
->u
.x11
.s
);
4977 if (c
->u
.pfd
.s
!= NULL
)
4978 pfd_close(c
->u
.pfd
.s
);
4982 if (c
->closes
== 0) {
4983 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4984 ssh2_pkt_adduint32(c
->remoteid
);
4987 del234(ssh_channels
, c
);
4988 bufchain_clear(&c
->v
.v2
.outbuffer
);
4992 * See if that was the last channel left open.
4994 if (count234(ssh_channels
) == 0) {
4997 * We used to send SSH_MSG_DISCONNECT here,
4998 * because I'd believed that _every_ conforming
4999 * SSH2 connection had to end with a disconnect
5000 * being sent by at least one side; apparently
5001 * I was wrong and it's perfectly OK to
5002 * unceremoniously slam the connection shut
5003 * when you're done, and indeed OpenSSH feels
5004 * this is more polite than sending a
5005 * DISCONNECT. So now we don't.
5007 logevent("All channels closed. Disconnecting");
5008 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5009 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5010 ssh2_pkt_addstring("All open channels closed");
5011 ssh2_pkt_addstring("en"); /* language tag */
5014 ssh_state
= SSH_STATE_CLOSED
;
5017 continue; /* remote sends close; ignore (FIXME) */
5018 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5019 unsigned i
= ssh2_pkt_getuint32();
5020 struct ssh_channel
*c
;
5021 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5023 continue; /* nonexistent channel */
5024 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5026 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5027 unsigned i
= ssh2_pkt_getuint32();
5028 struct ssh_channel
*c
;
5029 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5031 continue; /* nonexistent channel */
5032 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5033 continue; /* dunno why they're confirming this */
5034 c
->remoteid
= ssh2_pkt_getuint32();
5035 c
->type
= CHAN_SOCKDATA
;
5036 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
5037 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
5038 bufchain_init(&c
->v
.v2
.outbuffer
);
5040 pfd_confirm(c
->u
.pfd
.s
);
5043 * We have a pending close on this channel,
5044 * which we decided on before the server acked
5045 * the channel open. So now we know the
5046 * remoteid, we can close it again.
5048 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5049 ssh2_pkt_adduint32(c
->remoteid
);
5052 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5053 unsigned i
= ssh2_pkt_getuint32();
5054 struct ssh_channel
*c
;
5055 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5057 continue; /* nonexistent channel */
5058 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5059 continue; /* dunno why they're failing this */
5061 logevent("Forwarded connection refused by server");
5063 pfd_close(c
->u
.pfd
.s
);
5065 del234(ssh_channels
, c
);
5067 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5070 int typelen
, want_reply
;
5071 struct ssh_channel
*c
;
5073 localid
= ssh2_pkt_getuint32();
5074 ssh2_pkt_getstring(&type
, &typelen
);
5075 want_reply
= ssh2_pkt_getbool();
5078 * First, check that the channel exists. Otherwise,
5079 * we can instantly disconnect with a rude message.
5081 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
5084 sprintf(buf
, "Received channel request for nonexistent"
5085 " channel %d", localid
);
5087 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5088 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5089 ssh2_pkt_addstring(buf
);
5090 ssh2_pkt_addstring("en"); /* language tag */
5092 connection_fatal(buf
);
5093 ssh_state
= SSH_STATE_CLOSED
;
5098 * Having got the channel number, we now look at
5099 * the request type string to see if it's something
5102 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5104 /* We recognise "exit-status" on the primary channel. */
5106 ssh_exitcode
= ssh2_pkt_getuint32();
5107 sprintf(buf
, "Server sent command exit status %d",
5111 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS
);
5112 ssh2_pkt_adduint32(c
->remoteid
);
5117 * This is a channel request we don't know
5118 * about, so we now either ignore the request
5119 * or respond with CHANNEL_FAILURE, depending
5123 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
5124 ssh2_pkt_adduint32(c
->remoteid
);
5128 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5132 struct ssh_channel
*c
;
5133 unsigned remid
, winsize
, pktsize
;
5134 ssh2_pkt_getstring(&type
, &typelen
);
5135 c
= smalloc(sizeof(struct ssh_channel
));
5137 remid
= ssh2_pkt_getuint32();
5138 winsize
= ssh2_pkt_getuint32();
5139 pktsize
= ssh2_pkt_getuint32();
5141 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5142 if (!ssh_X11_fwd_enabled
)
5143 error
= "X11 forwarding is not enabled";
5144 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
5146 error
= "Unable to open an X11 connection";
5150 } else if (typelen
== 15 &&
5151 !memcmp(type
, "forwarded-tcpip", 15)) {
5152 struct ssh_rportfwd pf
, *realpf
;
5155 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
5156 pf
.sport
= ssh2_pkt_getuint32();
5157 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
5158 if (realpf
== NULL
) {
5159 error
= "Remote port is not recognised";
5161 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5164 sprintf(buf
, "Received remote port open request for %s:%d",
5165 realpf
->dhost
, realpf
->dport
);
5168 sprintf(buf
, "Port open failed: %s", e
);
5170 error
= "Port open failed";
5172 logevent("Forwarded port opened successfully");
5173 c
->type
= CHAN_SOCKDATA
;
5176 } else if (typelen
== 22 &&
5177 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5178 if (!ssh_agentfwd_enabled
)
5179 error
= "Agent forwarding is not enabled";
5181 c
->type
= CHAN_AGENT
; /* identify channel type */
5182 c
->u
.a
.lensofar
= 0;
5185 error
= "Unsupported channel type requested";
5188 c
->remoteid
= remid
;
5190 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5191 ssh2_pkt_adduint32(c
->remoteid
);
5192 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5193 ssh2_pkt_addstring(error
);
5194 ssh2_pkt_addstring("en"); /* language tag */
5198 c
->localid
= alloc_channel_id();
5200 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5201 c
->v
.v2
.remwindow
= winsize
;
5202 c
->v
.v2
.remmaxpkt
= pktsize
;
5203 bufchain_init(&c
->v
.v2
.outbuffer
);
5204 add234(ssh_channels
, c
);
5205 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5206 ssh2_pkt_adduint32(c
->remoteid
);
5207 ssh2_pkt_adduint32(c
->localid
);
5208 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5209 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5213 bombout(("Strange packet received: type %d", pktin
.type
));
5218 * We have spare data. Add it to the channel buffer.
5220 ssh2_add_channel_data(mainchan
, in
, inlen
);
5225 struct ssh_channel
*c
;
5227 * Try to send data on all channels if we can.
5229 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5230 int bufsize
= ssh2_try_send(c
);
5233 case CHAN_MAINSESSION
:
5234 /* stdin need not receive an unthrottle
5235 * notification since it will be polled */
5238 x11_unthrottle(c
->u
.x11
.s
);
5241 /* agent sockets are request/response and need no
5242 * buffer management */
5245 pfd_unthrottle(c
->u
.pfd
.s
);
5257 * Handle the top-level SSH2 protocol.
5259 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5261 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5263 do_ssh2_authconn(in
, inlen
, ispkt
);
5267 * Called to set up the connection.
5269 * Returns an error message, or NULL on success.
5271 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5276 if (crypto_startup() == 0)
5277 return "Microsoft high encryption pack not installed!";
5283 ssh1_throttle_count
= 0;
5284 ssh_overall_bufsize
= 0;
5285 ssh_fallback_cmd
= 0;
5287 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5295 * Called to send data down the Telnet connection.
5297 static int ssh_send(char *buf
, int len
)
5299 if (s
== NULL
|| ssh_protocol
== NULL
)
5302 ssh_protocol(buf
, len
, 0);
5304 return ssh_sendbuffer();
5308 * Called to query the current amount of buffered stdin data.
5310 static int ssh_sendbuffer(void)
5314 if (s
== NULL
|| ssh_protocol
== NULL
)
5318 * If the SSH socket itself has backed up, add the total backup
5319 * size on that to any individual buffer on the stdin channel.
5322 if (ssh_throttled_all
)
5323 override_value
= ssh_overall_bufsize
;
5325 if (ssh_version
== 1) {
5326 return override_value
;
5327 } else if (ssh_version
== 2) {
5328 if (!mainchan
|| mainchan
->closes
> 0)
5329 return override_value
;
5331 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5338 * Called to set the size of the window from SSH's POV.
5340 static void ssh_size(void)
5342 switch (ssh_state
) {
5343 case SSH_STATE_BEFORE_SIZE
:
5344 case SSH_STATE_PREPACKET
:
5345 case SSH_STATE_CLOSED
:
5346 break; /* do nothing */
5347 case SSH_STATE_INTERMED
:
5348 size_needed
= TRUE
; /* buffer for later */
5350 case SSH_STATE_SESSION
:
5352 if (ssh_version
== 1) {
5353 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5354 PKT_INT
, rows
, PKT_INT
, cols
,
5355 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5357 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5358 ssh2_pkt_adduint32(mainchan
->remoteid
);
5359 ssh2_pkt_addstring("window-change");
5360 ssh2_pkt_addbool(0);
5361 ssh2_pkt_adduint32(cols
);
5362 ssh2_pkt_adduint32(rows
);
5363 ssh2_pkt_adduint32(0);
5364 ssh2_pkt_adduint32(0);
5373 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5374 * can send an EOF and collect resulting output (e.g. `plink
5377 static void ssh_special(Telnet_Special code
)
5379 if (code
== TS_EOF
) {
5380 if (ssh_state
!= SSH_STATE_SESSION
) {
5382 * Buffer the EOF in case we are pre-SESSION, so we can
5383 * send it as soon as we reach SESSION.
5389 if (ssh_version
== 1) {
5390 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5392 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5393 ssh2_pkt_adduint32(mainchan
->remoteid
);
5396 logevent("Sent EOF message");
5397 } else if (code
== TS_PING
) {
5398 if (ssh_state
== SSH_STATE_CLOSED
5399 || ssh_state
== SSH_STATE_PREPACKET
) return;
5400 if (ssh_version
== 1) {
5401 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5403 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5404 ssh2_pkt_addstring_start();
5412 void *new_sock_channel(Socket s
)
5414 struct ssh_channel
*c
;
5415 c
= smalloc(sizeof(struct ssh_channel
));
5418 c
->remoteid
= -1; /* to be set when open confirmed */
5419 c
->localid
= alloc_channel_id();
5421 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5423 add234(ssh_channels
, c
);
5429 * This is called when stdout/stderr (the entity to which
5430 * from_backend sends data) manages to clear some backlog.
5432 void ssh_unthrottle(int bufsize
)
5434 if (ssh_version
== 1) {
5435 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5436 ssh1_stdout_throttling
= 0;
5440 if (mainchan
&& mainchan
->closes
== 0)
5441 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5445 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5447 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5450 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5453 if (ssh_version
== 1) {
5454 send_packet(SSH1_MSG_PORT_OPEN
,
5455 PKT_INT
, c
->localid
,
5458 //PKT_STR, <org:orgport>,
5461 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5462 ssh2_pkt_addstring("direct-tcpip");
5463 ssh2_pkt_adduint32(c
->localid
);
5464 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5465 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5466 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5467 ssh2_pkt_addstring(hostname
);
5468 ssh2_pkt_adduint32(port
);
5470 * We make up values for the originator data; partly it's
5471 * too much hassle to keep track, and partly I'm not
5472 * convinced the server should be told details like that
5473 * about my local network configuration.
5475 ssh2_pkt_addstring("client-side-connection");
5476 ssh2_pkt_adduint32(0);
5482 static Socket
ssh_socket(void)
5487 static int ssh_sendok(void)
5492 static int ssh_ldisc(int option
)
5494 if (option
== LD_ECHO
)
5496 if (option
== LD_EDIT
)
5501 static int ssh_return_exitcode(void)
5503 return ssh_exitcode
;
5506 Backend ssh_backend
= {
5513 ssh_return_exitcode
,