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
);
312 static void ssh2_pkt_init(int pkt_type
);
313 static void ssh2_pkt_addbool(unsigned char value
);
314 static void ssh2_pkt_adduint32(unsigned long value
);
315 static void ssh2_pkt_addstring_start(void);
316 static void ssh2_pkt_addstring_str(char *data
);
317 static void ssh2_pkt_addstring_data(char *data
, int len
);
318 static void ssh2_pkt_addstring(char *data
);
319 static char *ssh2_mpint_fmt(Bignum b
, int *len
);
320 static void ssh2_pkt_addmp(Bignum b
);
321 static int ssh2_pkt_construct(void);
322 static void ssh2_pkt_send(void);
325 * Buffer management constants. There are several of these for
326 * various different purposes:
328 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
329 * on a local data stream before we throttle the whole SSH
330 * connection (in SSH1 only). Throttling the whole connection is
331 * pretty drastic so we set this high in the hope it won't
334 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
335 * on the SSH connection itself before we defensively throttle
336 * _all_ local data streams. This is pretty drastic too (though
337 * thankfully unlikely in SSH2 since the window mechanism should
338 * ensure that the server never has any need to throttle its end
339 * of the connection), so we set this high as well.
341 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
345 #define SSH1_BUFFER_LIMIT 32768
346 #define SSH_MAX_BACKLOG 32768
347 #define OUR_V2_WINSIZE 16384
349 const static struct ssh_kex
*kex_algs
[] = {
350 &ssh_diffiehellman_gex
,
354 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
356 static void nullmac_key(unsigned char *key
)
359 static void nullmac_generate(unsigned char *blk
, int len
,
363 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
)
367 const static struct ssh_mac ssh_mac_none
= {
368 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
370 const static struct ssh_mac
*macs
[] = {
371 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
373 const static struct ssh_mac
*buggymacs
[] = {
374 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
377 static void ssh_comp_none_init(void)
380 static int ssh_comp_none_block(unsigned char *block
, int len
,
381 unsigned char **outblock
, int *outlen
)
385 static int ssh_comp_none_disable(void)
389 const static struct ssh_compress ssh_comp_none
= {
391 ssh_comp_none_init
, ssh_comp_none_block
,
392 ssh_comp_none_init
, ssh_comp_none_block
,
393 ssh_comp_none_disable
395 extern const struct ssh_compress ssh_zlib
;
396 const static struct ssh_compress
*compressions
[] = {
397 &ssh_zlib
, &ssh_comp_none
400 enum { /* channel types */
405 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
409 * 2-3-4 tree storing channels.
412 unsigned remoteid
, localid
;
416 struct ssh1_data_channel
{
419 struct ssh2_data_channel
{
421 unsigned remwindow
, remmaxpkt
;
426 struct ssh_agent_channel
{
427 unsigned char *message
;
428 unsigned char msglen
[4];
429 int lensofar
, totallen
;
431 struct ssh_x11_channel
{
434 struct ssh_pfd_channel
{
441 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
442 * 2 use this structure in different ways, reflecting SSH 2's
443 * altogether saner approach to port forwarding.
445 * In SSH 1, you arrange a remote forwarding by sending the server
446 * the remote port number, and the local destination host:port.
447 * When a connection comes in, the server sends you back that
448 * host:port pair, and you connect to it. This is a ready-made
449 * security hole if you're not on the ball: a malicious server
450 * could send you back _any_ host:port pair, so if you trustingly
451 * connect to the address it gives you then you've just opened the
452 * entire inside of your corporate network just by connecting
453 * through it to a dodgy SSH server. Hence, we must store a list of
454 * host:port pairs we _are_ trying to forward to, and reject a
455 * connection request from the server if it's not in the list.
457 * In SSH 2, each side of the connection minds its own business and
458 * doesn't send unnecessary information to the other. You arrange a
459 * remote forwarding by sending the server just the remote port
460 * number. When a connection comes in, the server tells you which
461 * of its ports was connected to; and _you_ have to remember what
462 * local host:port pair went with that port number.
464 * Hence: in SSH 1 this structure stores host:port pairs we intend
465 * to allow connections to, and is indexed by those host:port
466 * pairs. In SSH 2 it stores a mapping from source port to
467 * destination host:port pair, and is indexed by source port.
469 struct ssh_rportfwd
{
470 unsigned sport
, dport
;
483 static SHA_State exhash
, exhashbase
;
485 static Socket s
= NULL
;
487 static unsigned char session_key
[32];
488 static int ssh1_compressing
;
489 static int ssh1_remote_protoflags
;
490 static int ssh1_local_protoflags
;
491 static int ssh_agentfwd_enabled
;
492 static int ssh_X11_fwd_enabled
;
493 static int ssh_remote_bugs
;
494 static const struct ssh_cipher
*cipher
= NULL
;
495 static const struct ssh2_cipher
*cscipher
= NULL
;
496 static const struct ssh2_cipher
*sccipher
= NULL
;
497 static const struct ssh_mac
*csmac
= NULL
;
498 static const struct ssh_mac
*scmac
= NULL
;
499 static const struct ssh_compress
*cscomp
= NULL
;
500 static const struct ssh_compress
*sccomp
= NULL
;
501 static const struct ssh_kex
*kex
= NULL
;
502 static const struct ssh_signkey
*hostkey
= NULL
;
503 static unsigned char ssh2_session_id
[20];
504 int (*ssh_get_line
) (const char *prompt
, char *str
, int maxlen
,
507 static char *savedhost
;
508 static int savedport
;
509 static int ssh_send_ok
;
510 static int ssh_echoing
, ssh_editing
;
512 static tree234
*ssh_channels
; /* indexed by local id */
513 static struct ssh_channel
*mainchan
; /* primary session channel */
514 static int ssh_exitcode
= -1;
516 static tree234
*ssh_rportfwds
;
520 SSH_STATE_BEFORE_SIZE
,
524 } ssh_state
= SSH_STATE_PREPACKET
;
526 static int size_needed
= FALSE
, eof_needed
= FALSE
;
528 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
529 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
530 static unsigned char *deferred_send_data
= NULL
;
531 static int deferred_len
= 0, deferred_size
= 0;
534 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
535 * that fails. This variable is the means by which scp.c can reach
536 * into the SSH code and find out which one it got.
538 int ssh_fallback_cmd
= 0;
540 static int ssh_version
;
541 static int ssh1_throttle_count
;
542 static int ssh_overall_bufsize
;
543 static int ssh_throttled_all
;
544 static int ssh1_stdout_throttling
;
545 static void (*ssh_protocol
) (unsigned char *in
, int inlen
, int ispkt
);
546 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
547 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
548 static void ssh_size(void);
549 static void ssh_special(Telnet_Special
);
550 static int ssh2_try_send(struct ssh_channel
*c
);
551 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
553 static void ssh_throttle_all(int enable
, int bufsize
);
554 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
555 static int (*s_rdpkt
) (unsigned char **data
, int *datalen
);
556 static int ssh_sendbuffer(void);
558 static struct rdpkt1_state_tag
{
559 long len
, pad
, biglen
, to_read
;
560 unsigned long realcrc
, gotcrc
;
566 static struct rdpkt2_state_tag
{
567 long len
, pad
, payload
, packetlen
, maclen
;
570 unsigned long incoming_sequence
;
573 static int ssh_channelcmp(void *av
, void *bv
)
575 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
576 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
577 if (a
->localid
< b
->localid
)
579 if (a
->localid
> b
->localid
)
583 static int ssh_channelfind(void *av
, void *bv
)
585 unsigned *a
= (unsigned *) av
;
586 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
594 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
596 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
597 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
599 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
600 return i
< 0 ?
-1 : +1;
601 if (a
->dport
> b
->dport
)
603 if (a
->dport
< b
->dport
)
608 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
610 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
611 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
613 if (a
->sport
> b
->sport
)
615 if (a
->sport
< b
->sport
)
620 static int alloc_channel_id(void)
622 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
623 unsigned low
, high
, mid
;
625 struct ssh_channel
*c
;
628 * First-fit allocation of channel numbers: always pick the
629 * lowest unused one. To do this, binary-search using the
630 * counted B-tree to find the largest channel ID which is in a
631 * contiguous sequence from the beginning. (Precisely
632 * everything in that sequence must have ID equal to its tree
633 * index plus CHANNEL_NUMBER_OFFSET.)
635 tsize
= count234(ssh_channels
);
639 while (high
- low
> 1) {
640 mid
= (high
+ low
) / 2;
641 c
= index234(ssh_channels
, mid
);
642 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
643 low
= mid
; /* this one is fine */
645 high
= mid
; /* this one is past it */
648 * Now low points to either -1, or the tree index of the
649 * largest ID in the initial sequence.
652 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
653 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
655 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
658 static void c_write(char *buf
, int len
)
660 if ((flags
& FLAG_STDERR
)) {
662 for (i
= 0; i
< len
; i
++)
664 fputc(buf
[i
], stderr
);
667 from_backend(1, buf
, len
);
670 static void c_write_untrusted(char *buf
, int len
)
673 for (i
= 0; i
< len
; i
++) {
676 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
681 static void c_write_str(char *buf
)
683 c_write(buf
, strlen(buf
));
687 * Collect incoming data in the incoming packet buffer.
688 * Decipher and verify the packet when it is completely read.
689 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
690 * Update the *data and *datalen variables.
691 * Return the additional nr of bytes needed, or 0 when
692 * a complete packet is available.
694 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
696 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
705 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
706 while ((*datalen
) == 0)
708 st
->len
= (st
->len
<< 8) + **data
;
709 (*data
)++, (*datalen
)--;
712 st
->pad
= 8 - (st
->len
% 8);
713 st
->biglen
= st
->len
+ st
->pad
;
714 pktin
.length
= st
->len
- 5;
716 if (pktin
.maxlen
< st
->biglen
) {
717 pktin
.maxlen
= st
->biglen
;
718 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
719 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
721 fatalbox("Out of memory");
724 st
->to_read
= st
->biglen
;
726 while (st
->to_read
> 0) {
727 st
->chunk
= st
->to_read
;
728 while ((*datalen
) == 0)
729 crReturn(st
->to_read
);
730 if (st
->chunk
> (*datalen
))
731 st
->chunk
= (*datalen
);
732 memcpy(st
->p
, *data
, st
->chunk
);
734 *datalen
-= st
->chunk
;
736 st
->to_read
-= st
->chunk
;
739 if (cipher
&& detect_attack(pktin
.data
, st
->biglen
, NULL
)) {
740 bombout(("Network attack (CRC compensation) detected!"));
745 cipher
->decrypt(pktin
.data
, st
->biglen
);
747 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
748 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
749 if (st
->gotcrc
!= st
->realcrc
) {
750 bombout(("Incorrect CRC received on packet"));
754 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
756 if (ssh1_compressing
) {
757 unsigned char *decompblk
;
759 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
760 &decompblk
, &decomplen
);
762 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
763 pktin
.maxlen
= st
->pad
+ decomplen
;
764 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
765 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
767 fatalbox("Out of memory");
770 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
772 pktin
.length
= decomplen
- 1;
775 pktin
.type
= pktin
.body
[-1];
777 log_packet(PKT_INCOMING
, pktin
.type
, ssh1_pkt_type(pktin
.type
),
778 pktin
.body
, pktin
.length
);
780 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
781 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
782 pktin
.type
== SSH1_MSG_DEBUG
||
783 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
784 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
785 long stringlen
= GET_32BIT(pktin
.body
);
786 if (stringlen
+ 4 != pktin
.length
) {
787 bombout(("Received data packet with bogus string length"));
792 if (pktin
.type
== SSH1_MSG_DEBUG
) {
793 /* log debug message */
795 int stringlen
= GET_32BIT(pktin
.body
);
796 strcpy(buf
, "Remote: ");
799 memcpy(buf
+ 8, pktin
.body
+ 4, stringlen
);
800 buf
[8 + stringlen
] = '\0';
803 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
808 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
809 /* log reason code in disconnect message */
811 unsigned msglen
= GET_32BIT(pktin
.body
);
813 strcpy(buf
, "Remote sent disconnect: ");
814 nowlen
= strlen(buf
);
815 if (msglen
> sizeof(buf
) - nowlen
- 1)
816 msglen
= sizeof(buf
) - nowlen
- 1;
817 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
818 buf
[nowlen
+ msglen
] = '\0';
820 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
827 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
829 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
837 st
->cipherblk
= sccipher
->blksize
;
840 if (st
->cipherblk
< 8)
843 if (pktin
.maxlen
< st
->cipherblk
) {
844 pktin
.maxlen
= st
->cipherblk
;
847 NULL ?
smalloc(st
->cipherblk
+
848 APIEXTRA
) : srealloc(pktin
.data
,
852 fatalbox("Out of memory");
856 * Acquire and decrypt the first block of the packet. This will
857 * contain the length and padding details.
859 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
860 while ((*datalen
) == 0)
861 crReturn(st
->cipherblk
- st
->i
);
862 pktin
.data
[st
->i
] = *(*data
)++;
867 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
870 * Now get the length and padding figures.
872 st
->len
= GET_32BIT(pktin
.data
);
873 st
->pad
= pktin
.data
[4];
876 * This enables us to deduce the payload length.
878 st
->payload
= st
->len
- st
->pad
- 1;
880 pktin
.length
= st
->payload
+ 5;
883 * So now we can work out the total packet length.
885 st
->packetlen
= st
->len
+ 4;
886 st
->maclen
= scmac ? scmac
->len
: 0;
889 * Adjust memory allocation if packet is too big.
891 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
892 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
895 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
900 fatalbox("Out of memory");
904 * Read and decrypt the remainder of the packet.
906 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
908 while ((*datalen
) == 0)
909 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
910 pktin
.data
[st
->i
] = *(*data
)++;
913 /* Decrypt everything _except_ the MAC. */
915 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
916 st
->packetlen
- st
->cipherblk
);
922 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
923 st
->incoming_sequence
)) {
924 bombout(("Incorrect MAC received on packet"));
927 st
->incoming_sequence
++; /* whether or not we MACed */
930 * Decompress packet payload.
933 unsigned char *newpayload
;
935 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
936 &newpayload
, &newlen
)) {
937 if (pktin
.maxlen
< newlen
+ 5) {
938 pktin
.maxlen
= newlen
+ 5;
941 NULL ?
smalloc(pktin
.maxlen
+
942 APIEXTRA
) : srealloc(pktin
.data
,
946 fatalbox("Out of memory");
948 pktin
.length
= 5 + newlen
;
949 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
955 pktin
.type
= pktin
.data
[5];
957 log_packet(PKT_INCOMING
, pktin
.type
, ssh2_pkt_type(pktin
.type
),
958 pktin
.data
+6, pktin
.length
-6);
960 switch (pktin
.type
) {
962 * These packets we must handle instantly.
964 case SSH2_MSG_DISCONNECT
:
966 /* log reason code in disconnect message */
968 int reason
= GET_32BIT(pktin
.data
+ 6);
969 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
971 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
972 sprintf(buf
, "Received disconnect message (%s)",
973 ssh2_disconnect_reasons
[reason
]);
975 sprintf(buf
, "Received disconnect message (unknown type %d)",
979 strcpy(buf
, "Disconnection message text: ");
980 nowlen
= strlen(buf
);
981 if (msglen
> sizeof(buf
) - nowlen
- 1)
982 msglen
= sizeof(buf
) - nowlen
- 1;
983 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
984 buf
[nowlen
+ msglen
] = '\0';
986 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
988 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
989 ssh2_disconnect_reasons
[reason
] : "unknown",
994 case SSH2_MSG_IGNORE
:
998 /* log the debug message */
1000 /* int display = pktin.body[6]; */
1001 int stringlen
= GET_32BIT(pktin
.data
+7);
1003 strcpy(buf
, "Remote debug message: ");
1004 prefix
= strlen(buf
);
1005 if (stringlen
> sizeof(buf
)-prefix
-1)
1006 stringlen
= sizeof(buf
)-prefix
-1;
1007 memcpy(buf
+ prefix
, pktin
.data
+ 11, stringlen
);
1008 buf
[prefix
+ stringlen
] = '\0';
1011 goto next_packet
; /* FIXME: print the debug message */
1014 * These packets we need do nothing about here.
1016 case SSH2_MSG_UNIMPLEMENTED
:
1017 case SSH2_MSG_SERVICE_REQUEST
:
1018 case SSH2_MSG_SERVICE_ACCEPT
:
1019 case SSH2_MSG_KEXINIT
:
1020 case SSH2_MSG_NEWKEYS
:
1021 case SSH2_MSG_KEXDH_INIT
:
1022 case SSH2_MSG_KEXDH_REPLY
:
1023 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1024 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1025 case SSH2_MSG_KEX_DH_GEX_INIT
:
1026 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1027 case SSH2_MSG_USERAUTH_REQUEST
:
1028 case SSH2_MSG_USERAUTH_FAILURE
:
1029 case SSH2_MSG_USERAUTH_SUCCESS
:
1030 case SSH2_MSG_USERAUTH_BANNER
:
1031 case SSH2_MSG_USERAUTH_PK_OK
:
1032 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1033 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1034 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1035 case SSH2_MSG_GLOBAL_REQUEST
:
1036 case SSH2_MSG_REQUEST_SUCCESS
:
1037 case SSH2_MSG_REQUEST_FAILURE
:
1038 case SSH2_MSG_CHANNEL_OPEN
:
1039 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1040 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1041 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1042 case SSH2_MSG_CHANNEL_DATA
:
1043 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1044 case SSH2_MSG_CHANNEL_EOF
:
1045 case SSH2_MSG_CHANNEL_CLOSE
:
1046 case SSH2_MSG_CHANNEL_REQUEST
:
1047 case SSH2_MSG_CHANNEL_SUCCESS
:
1048 case SSH2_MSG_CHANNEL_FAILURE
:
1052 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1055 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
1056 ssh2_pkt_adduint32(st
->incoming_sequence
- 1);
1064 static void ssh1_pktout_size(int len
)
1068 len
+= 5; /* type and CRC */
1069 pad
= 8 - (len
% 8);
1072 pktout
.length
= len
- 5;
1073 if (pktout
.maxlen
< biglen
) {
1074 pktout
.maxlen
= biglen
;
1076 /* Allocate enough buffer space for extra block
1077 * for MS CryptEncrypt() */
1078 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
1079 srealloc(pktout
.data
, biglen
+ 12));
1081 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
1082 srealloc(pktout
.data
, biglen
+ 4));
1085 fatalbox("Out of memory");
1087 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
1090 static void s_wrpkt_start(int type
, int len
)
1092 ssh1_pktout_size(len
);
1096 static int s_wrpkt_prepare(void)
1098 int pad
, len
, biglen
, i
;
1101 pktout
.body
[-1] = pktout
.type
;
1103 log_packet(PKT_OUTGOING
, pktout
.type
, ssh1_pkt_type(pktout
.type
),
1104 pktout
.body
, pktout
.length
);
1106 if (ssh1_compressing
) {
1107 unsigned char *compblk
;
1109 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
1110 &compblk
, &complen
);
1111 ssh1_pktout_size(complen
- 1);
1112 memcpy(pktout
.body
- 1, compblk
, complen
);
1116 len
= pktout
.length
+ 5; /* type and CRC */
1117 pad
= 8 - (len
% 8);
1120 for (i
= 0; i
< pad
; i
++)
1121 pktout
.data
[i
+ 4] = random_byte();
1122 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
1123 PUT_32BIT(pktout
.data
+ biglen
, crc
);
1124 PUT_32BIT(pktout
.data
, len
);
1127 cipher
->encrypt(pktout
.data
+ 4, biglen
);
1132 static void s_wrpkt(void)
1135 len
= s_wrpkt_prepare();
1136 backlog
= sk_write(s
, pktout
.data
, len
);
1137 if (backlog
> SSH_MAX_BACKLOG
)
1138 ssh_throttle_all(1, backlog
);
1141 static void s_wrpkt_defer(void)
1144 len
= s_wrpkt_prepare();
1145 if (deferred_len
+ len
> deferred_size
) {
1146 deferred_size
= deferred_len
+ len
+ 128;
1147 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1149 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1150 deferred_len
+= len
;
1154 * Construct a packet with the specified contents.
1156 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1158 unsigned char *p
, *argp
, argchar
;
1159 unsigned long argint
;
1160 int pktlen
, argtype
, arglen
;
1164 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1167 (void) va_arg(ap1
, int);
1171 (void) va_arg(ap1
, char);
1175 (void) va_arg(ap1
, unsigned char *);
1176 arglen
= va_arg(ap1
, int);
1180 argp
= va_arg(ap1
, unsigned char *);
1181 arglen
= strlen(argp
);
1182 pktlen
+= 4 + arglen
;
1185 bn
= va_arg(ap1
, Bignum
);
1186 pktlen
+= ssh1_bignum_length(bn
);
1193 s_wrpkt_start(pkttype
, pktlen
);
1196 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1199 argint
= va_arg(ap2
, int);
1200 PUT_32BIT(p
, argint
);
1204 argchar
= va_arg(ap2
, unsigned char);
1209 argp
= va_arg(ap2
, unsigned char *);
1210 arglen
= va_arg(ap2
, int);
1211 memcpy(p
, argp
, arglen
);
1215 argp
= va_arg(ap2
, unsigned char *);
1216 arglen
= strlen(argp
);
1217 PUT_32BIT(p
, arglen
);
1218 memcpy(p
+ 4, argp
, arglen
);
1222 bn
= va_arg(ap2
, Bignum
);
1223 p
+= ssh1_write_bignum(p
, bn
);
1229 static void send_packet(int pkttype
, ...)
1232 va_start(ap1
, pkttype
);
1233 va_start(ap2
, pkttype
);
1234 construct_packet(pkttype
, ap1
, ap2
);
1238 static void defer_packet(int pkttype
, ...)
1241 va_start(ap1
, pkttype
);
1242 va_start(ap2
, pkttype
);
1243 construct_packet(pkttype
, ap1
, ap2
);
1247 static int ssh_versioncmp(char *a
, char *b
)
1250 unsigned long av
, bv
;
1252 av
= strtoul(a
, &ae
, 10);
1253 bv
= strtoul(b
, &be
, 10);
1255 return (av
< bv ?
-1 : +1);
1260 av
= strtoul(ae
, &ae
, 10);
1261 bv
= strtoul(be
, &be
, 10);
1263 return (av
< bv ?
-1 : +1);
1269 * Utility routines for putting an SSH-protocol `string' and
1270 * `uint32' into a SHA state.
1273 static void sha_string(SHA_State
* s
, void *str
, int len
)
1275 unsigned char lenblk
[4];
1276 PUT_32BIT(lenblk
, len
);
1277 SHA_Bytes(s
, lenblk
, 4);
1278 SHA_Bytes(s
, str
, len
);
1281 static void sha_uint32(SHA_State
* s
, unsigned i
)
1283 unsigned char intblk
[4];
1284 PUT_32BIT(intblk
, i
);
1285 SHA_Bytes(s
, intblk
, 4);
1289 * SSH2 packet construction functions.
1291 static void ssh2_pkt_ensure(int length
)
1293 if (pktout
.maxlen
< length
) {
1294 pktout
.maxlen
= length
+ 256;
1297 NULL ?
smalloc(pktout
.maxlen
+
1298 APIEXTRA
) : srealloc(pktout
.data
,
1302 fatalbox("Out of memory");
1305 static void ssh2_pkt_adddata(void *data
, int len
)
1307 pktout
.length
+= len
;
1308 ssh2_pkt_ensure(pktout
.length
);
1309 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1311 static void ssh2_pkt_addbyte(unsigned char byte
)
1313 ssh2_pkt_adddata(&byte
, 1);
1315 static void ssh2_pkt_init(int pkt_type
)
1318 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1320 static void ssh2_pkt_addbool(unsigned char value
)
1322 ssh2_pkt_adddata(&value
, 1);
1324 static void ssh2_pkt_adduint32(unsigned long value
)
1327 PUT_32BIT(x
, value
);
1328 ssh2_pkt_adddata(x
, 4);
1330 static void ssh2_pkt_addstring_start(void)
1332 ssh2_pkt_adduint32(0);
1333 pktout
.savedpos
= pktout
.length
;
1335 static void ssh2_pkt_addstring_str(char *data
)
1337 ssh2_pkt_adddata(data
, strlen(data
));
1338 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1339 pktout
.length
- pktout
.savedpos
);
1341 static void ssh2_pkt_addstring_data(char *data
, int len
)
1343 ssh2_pkt_adddata(data
, len
);
1344 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1345 pktout
.length
- pktout
.savedpos
);
1347 static void ssh2_pkt_addstring(char *data
)
1349 ssh2_pkt_addstring_start();
1350 ssh2_pkt_addstring_str(data
);
1352 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1355 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1358 fatalbox("out of memory");
1360 for (i
= 1; i
<= n
; i
++)
1361 p
[i
] = bignum_byte(b
, n
- i
);
1363 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1365 memmove(p
, p
+ i
, n
+ 1 - i
);
1369 static void ssh2_pkt_addmp(Bignum b
)
1373 p
= ssh2_mpint_fmt(b
, &len
);
1374 ssh2_pkt_addstring_start();
1375 ssh2_pkt_addstring_data(p
, len
);
1380 * Construct an SSH2 final-form packet: compress it, encrypt it,
1381 * put the MAC on it. Final packet, ready to be sent, is stored in
1382 * pktout.data. Total length is returned.
1384 static int ssh2_pkt_construct(void)
1386 int cipherblk
, maclen
, padding
, i
;
1387 static unsigned long outgoing_sequence
= 0;
1389 log_packet(PKT_OUTGOING
, pktout
.data
[5], ssh2_pkt_type(pktout
.data
[5]),
1390 pktout
.data
+ 6, pktout
.length
- 6);
1393 * Compress packet payload.
1396 unsigned char *newpayload
;
1398 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1399 &newpayload
, &newlen
)) {
1401 ssh2_pkt_adddata(newpayload
, newlen
);
1407 * Add padding. At least four bytes, and must also bring total
1408 * length (minus MAC) up to a multiple of the block size.
1410 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1411 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1414 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1415 maclen
= csmac ? csmac
->len
: 0;
1416 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1417 pktout
.data
[4] = padding
;
1418 for (i
= 0; i
< padding
; i
++)
1419 pktout
.data
[pktout
.length
+ i
] = random_byte();
1420 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1422 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1424 outgoing_sequence
++; /* whether or not we MACed */
1427 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1429 /* Ready-to-send packet starts at pktout.data. We return length. */
1430 return pktout
.length
+ padding
+ maclen
;
1434 * Construct and send an SSH2 packet immediately.
1436 static void ssh2_pkt_send(void)
1440 len
= ssh2_pkt_construct();
1441 backlog
= sk_write(s
, pktout
.data
, len
);
1442 if (backlog
> SSH_MAX_BACKLOG
)
1443 ssh_throttle_all(1, backlog
);
1447 * Construct an SSH2 packet and add it to a deferred data block.
1448 * Useful for sending multiple packets in a single sk_write() call,
1449 * to prevent a traffic-analysing listener from being able to work
1450 * out the length of any particular packet (such as the password
1453 * Note that because SSH2 sequence-numbers its packets, this can
1454 * NOT be used as an m4-style `defer' allowing packets to be
1455 * constructed in one order and sent in another.
1457 static void ssh2_pkt_defer(void)
1459 int len
= ssh2_pkt_construct();
1460 if (deferred_len
+ len
> deferred_size
) {
1461 deferred_size
= deferred_len
+ len
+ 128;
1462 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1464 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1465 deferred_len
+= len
;
1469 * Send the whole deferred data block constructed by
1470 * ssh2_pkt_defer() or SSH1's defer_packet().
1472 static void ssh_pkt_defersend(void)
1475 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1476 deferred_len
= deferred_size
= 0;
1477 sfree(deferred_send_data
);
1478 deferred_send_data
= NULL
;
1479 if (backlog
> SSH_MAX_BACKLOG
)
1480 ssh_throttle_all(1, backlog
);
1484 void bndebug(char *string
, Bignum b
)
1488 p
= ssh2_mpint_fmt(b
, &len
);
1489 debug(("%s", string
));
1490 for (i
= 0; i
< len
; i
++)
1491 debug((" %02x", p
[i
]));
1497 static void sha_mpint(SHA_State
* s
, Bignum b
)
1501 p
= ssh2_mpint_fmt(b
, &len
);
1502 sha_string(s
, p
, len
);
1507 * SSH2 packet decode functions.
1509 static unsigned long ssh2_pkt_getuint32(void)
1511 unsigned long value
;
1512 if (pktin
.length
- pktin
.savedpos
< 4)
1513 return 0; /* arrgh, no way to decline (FIXME?) */
1514 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1515 pktin
.savedpos
+= 4;
1518 static int ssh2_pkt_getbool(void)
1520 unsigned long value
;
1521 if (pktin
.length
- pktin
.savedpos
< 1)
1522 return 0; /* arrgh, no way to decline (FIXME?) */
1523 value
= pktin
.data
[pktin
.savedpos
] != 0;
1527 static void ssh2_pkt_getstring(char **p
, int *length
)
1530 if (pktin
.length
- pktin
.savedpos
< 4)
1532 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1533 pktin
.savedpos
+= 4;
1534 if (pktin
.length
- pktin
.savedpos
< *length
)
1536 *p
= pktin
.data
+ pktin
.savedpos
;
1537 pktin
.savedpos
+= *length
;
1539 static Bignum
ssh2_pkt_getmp(void)
1545 ssh2_pkt_getstring(&p
, &length
);
1549 bombout(("internal error: Can't handle negative mpints"));
1552 b
= bignum_from_bytes(p
, length
);
1557 * Examine the remote side's version string and compare it against
1558 * a list of known buggy implementations.
1560 static void ssh_detect_bugs(char *vstring
)
1562 char *imp
; /* pointer to implementation part */
1564 imp
+= strcspn(imp
, "-");
1566 imp
+= strcspn(imp
, "-");
1569 ssh_remote_bugs
= 0;
1571 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1572 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1573 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1575 * These versions don't support SSH1_MSG_IGNORE, so we have
1576 * to use a different defence against password length
1579 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1580 logevent("We believe remote version has SSH1 ignore bug");
1583 if (!strcmp(imp
, "Cisco-1.25")) {
1585 * These versions need a plain password sent; they can't
1586 * handle having a null and a random length of data after
1589 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1590 logevent("We believe remote version needs a plain SSH1 password");
1593 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1594 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1595 !strncmp(imp
, "2.1 ", 4)) {
1597 * These versions have the HMAC bug.
1599 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1600 logevent("We believe remote version has SSH2 HMAC bug");
1604 static int do_ssh_init(unsigned char c
)
1607 static char version
[10];
1608 static char *vstring
;
1609 static int vstrsize
;
1615 /* Search for the string "SSH-" in the input. */
1618 static const int transS
[] = { 1, 2, 2, 1 };
1619 static const int transH
[] = { 0, 0, 3, 0 };
1620 static const int transminus
[] = { 0, 0, 0, -1 };
1631 crReturn(1); /* get another character */
1635 vstring
= smalloc(vstrsize
);
1636 strcpy(vstring
, "SSH-");
1640 crReturn(1); /* get another char */
1641 if (vslen
>= vstrsize
- 1) {
1643 vstring
= srealloc(vstring
, vstrsize
);
1645 vstring
[vslen
++] = c
;
1650 } else if (i
< sizeof(version
) - 1)
1652 } else if (c
== '\n')
1656 ssh_agentfwd_enabled
= FALSE
;
1657 rdpkt2_state
.incoming_sequence
= 0;
1660 vlog
= smalloc(20 + vslen
);
1661 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1662 sprintf(vlog
, "Server version: %s", vstring
);
1664 ssh_detect_bugs(vstring
);
1668 * Server version "1.99" means we can choose whether we use v1
1669 * or v2 protocol. Choice is based on cfg.sshprot.
1671 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1673 * This is a v2 server. Begin v2 protocol.
1675 char verstring
[80], vlog
[100];
1676 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1677 SHA_Init(&exhashbase
);
1679 * Hash our version string and their version string.
1681 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1682 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1683 sprintf(vlog
, "We claim version: %s", verstring
);
1685 strcat(verstring
, "\n");
1686 logevent("Using SSH protocol version 2");
1687 sk_write(s
, verstring
, strlen(verstring
));
1688 ssh_protocol
= ssh2_protocol
;
1690 s_rdpkt
= ssh2_rdpkt
;
1693 * This is a v1 server. Begin v1 protocol.
1695 char verstring
[80], vlog
[100];
1696 sprintf(verstring
, "SSH-%s-%s",
1697 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1699 sprintf(vlog
, "We claim version: %s", verstring
);
1701 strcat(verstring
, "\n");
1702 logevent("Using SSH protocol version 1");
1703 sk_write(s
, verstring
, strlen(verstring
));
1704 ssh_protocol
= ssh1_protocol
;
1706 s_rdpkt
= ssh1_rdpkt
;
1708 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1715 static void ssh_gotdata(unsigned char *data
, int datalen
)
1720 * To begin with, feed the characters one by one to the
1721 * protocol initialisation / selection function do_ssh_init().
1722 * When that returns 0, we're done with the initial greeting
1723 * exchange and can move on to packet discipline.
1728 crReturnV
; /* more data please */
1729 ret
= do_ssh_init(*data
);
1737 * We emerge from that loop when the initial negotiation is
1738 * over and we have selected an s_rdpkt function. Now pass
1739 * everything to s_rdpkt, and then pass the resulting packets
1740 * to the proper protocol handler.
1745 while (datalen
> 0) {
1746 if (s_rdpkt(&data
, &datalen
) == 0) {
1747 if (ssh_state
== SSH_STATE_CLOSED
) {
1750 ssh_protocol(NULL
, 0, 1);
1751 if (ssh_state
== SSH_STATE_CLOSED
) {
1761 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1764 ssh_state
= SSH_STATE_CLOSED
;
1770 /* A socket error has occurred. */
1771 connection_fatal(error_msg
);
1773 /* Otherwise, the remote side closed the connection normally. */
1778 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1780 ssh_gotdata(data
, len
);
1781 if (ssh_state
== SSH_STATE_CLOSED
) {
1791 static void ssh_sent(Plug plug
, int bufsize
)
1794 * If the send backlog on the SSH socket itself clears, we
1795 * should unthrottle the whole world if it was throttled.
1797 if (bufsize
< SSH_MAX_BACKLOG
)
1798 ssh_throttle_all(0, bufsize
);
1802 * Connect to specified host and port.
1803 * Returns an error message, or NULL on success.
1804 * Also places the canonical host name into `realhost'. It must be
1805 * freed by the caller.
1807 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1809 static struct plug_function_table fn_table
= {
1814 }, *fn_table_ptr
= &fn_table
;
1823 savedhost
= smalloc(1 + strlen(host
));
1825 fatalbox("Out of memory");
1826 strcpy(savedhost
, host
);
1829 port
= 22; /* default ssh port */
1844 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1847 addr
= sk_namelookup(host
, realhost
);
1848 if ((err
= sk_addr_error(addr
)))
1852 *realhost
= strdup(FWhost
);
1859 char buf
[200], addrbuf
[100];
1860 sk_getaddr(addr
, addrbuf
, 100);
1861 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1864 s
= sk_new(addr
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1865 if ((err
= sk_socket_error(s
)))
1869 sk_write(s
, "connect ", 8);
1870 sk_write(s
, FWhost
, strlen(FWhost
));
1873 sprintf(buf
, " %d\n", FWport
);
1874 sk_write(s
, buf
, strlen(buf
));
1882 * Throttle or unthrottle the SSH connection.
1884 static void ssh1_throttle(int adjust
)
1886 int old_count
= ssh1_throttle_count
;
1887 ssh1_throttle_count
+= adjust
;
1888 assert(ssh1_throttle_count
>= 0);
1889 if (ssh1_throttle_count
&& !old_count
) {
1890 sk_set_frozen(s
, 1);
1891 } else if (!ssh1_throttle_count
&& old_count
) {
1892 sk_set_frozen(s
, 0);
1897 * Throttle or unthrottle _all_ local data streams (for when sends
1898 * on the SSH connection itself back up).
1900 static void ssh_throttle_all(int enable
, int bufsize
)
1903 struct ssh_channel
*c
;
1905 if (enable
== ssh_throttled_all
)
1907 ssh_throttled_all
= enable
;
1908 ssh_overall_bufsize
= bufsize
;
1911 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
1913 case CHAN_MAINSESSION
:
1915 * This is treated separately, outside the switch.
1919 x11_override_throttle(c
->u
.x11
.s
, enable
);
1922 /* Agent channels require no buffer management. */
1925 pfd_override_throttle(c
->u
.x11
.s
, enable
);
1932 * Handle the key exchange and user authentication phases.
1934 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1938 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
1939 unsigned char cookie
[8];
1940 struct RSAKey servkey
, hostkey
;
1941 struct MD5Context md5c
;
1942 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1943 static int tried_publickey
, tried_agent
;
1944 static int tis_auth_refused
, ccard_auth_refused
;
1945 static unsigned char session_id
[16];
1946 static int cipher_type
;
1947 static char username
[100];
1948 static void *publickey_blob
;
1949 int publickey_bloblen
;
1956 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1957 bombout(("Public key packet not received"));
1961 logevent("Received public keys");
1963 memcpy(cookie
, pktin
.body
, 8);
1965 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1966 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
1969 * Log the host key fingerprint.
1973 logevent("Host key fingerprint is:");
1974 strcpy(logmsg
, " ");
1975 hostkey
.comment
= NULL
;
1976 rsa_fingerprint(logmsg
+ strlen(logmsg
),
1977 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
1981 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
1982 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
1983 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
1985 ssh1_local_protoflags
=
1986 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1987 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1990 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1991 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1992 MD5Update(&md5c
, pktin
.body
, 8);
1993 MD5Final(session_id
, &md5c
);
1995 for (i
= 0; i
< 32; i
++)
1996 session_key
[i
] = random_byte();
1998 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2000 rsabuf
= smalloc(len
);
2002 fatalbox("Out of memory");
2005 * Verify the host key.
2009 * First format the key into a string.
2011 int len
= rsastr_len(&hostkey
);
2012 char fingerprint
[100];
2013 char *keystr
= smalloc(len
);
2015 fatalbox("Out of memory");
2016 rsastr_fmt(keystr
, &hostkey
);
2017 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2018 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
2023 for (i
= 0; i
< 32; i
++) {
2024 rsabuf
[i
] = session_key
[i
];
2026 rsabuf
[i
] ^= session_id
[i
];
2029 if (hostkey
.bytes
> servkey
.bytes
) {
2030 rsaencrypt(rsabuf
, 32, &servkey
);
2031 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
2033 rsaencrypt(rsabuf
, 32, &hostkey
);
2034 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
2037 logevent("Encrypted session key");
2040 int cipher_chosen
= 0, warn
= 0;
2041 char *cipher_string
= NULL
;
2042 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2043 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2044 if (next_cipher
== CIPHER_WARN
) {
2045 /* If/when we choose a cipher, warn about it */
2047 } else if (next_cipher
== CIPHER_AES
) {
2048 /* XXX Probably don't need to mention this. */
2049 logevent("AES not supported in SSH1, skipping");
2051 switch (next_cipher
) {
2052 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
2053 cipher_string
= "3DES"; break;
2054 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
2055 cipher_string
= "Blowfish"; break;
2056 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
2057 cipher_string
= "single-DES"; break;
2059 if (supported_ciphers_mask
& (1 << cipher_type
))
2063 if (!cipher_chosen
) {
2064 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2065 bombout(("Server violates SSH 1 protocol by not "
2066 "supporting 3DES encryption"));
2068 /* shouldn't happen */
2069 bombout(("No supported ciphers found"));
2073 /* Warn about chosen cipher if necessary. */
2075 askcipher(cipher_string
, 0);
2078 switch (cipher_type
) {
2079 case SSH_CIPHER_3DES
:
2080 logevent("Using 3DES encryption");
2082 case SSH_CIPHER_DES
:
2083 logevent("Using single-DES encryption");
2085 case SSH_CIPHER_BLOWFISH
:
2086 logevent("Using Blowfish encryption");
2090 send_packet(SSH1_CMSG_SESSION_KEY
,
2091 PKT_CHAR
, cipher_type
,
2092 PKT_DATA
, cookie
, 8,
2093 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
2094 PKT_DATA
, rsabuf
, len
,
2095 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
2097 logevent("Trying to enable encryption...");
2101 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2102 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
2103 cipher
->sesskey(session_key
);
2107 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2108 bombout(("Encryption not successfully enabled"));
2112 logevent("Successfully started encryption");
2118 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2120 if (!ssh_get_line("login as: ",
2121 username
, sizeof(username
), FALSE
)) {
2123 * get_line failed to get a username.
2126 logevent("No username provided. Abandoning session.");
2127 ssh_state
= SSH_STATE_CLOSED
;
2131 c_write_str("login as: ");
2134 crWaitUntil(!ispkt
);
2136 switch (c
= *in
++) {
2145 c_write_str("\b \b");
2152 c_write_str("\b \b");
2162 if (((c
>= ' ' && c
<= '~') ||
2163 ((unsigned char) c
>= 160))
2164 && pos
< sizeof(username
)-1) {
2165 username
[pos
++] = c
;
2171 c_write_str("\r\n");
2172 username
[strcspn(username
, "\n\r")] = '\0';
2175 strncpy(username
, cfg
.username
, 99);
2176 username
[99] = '\0';
2179 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2181 char userlog
[22 + sizeof(username
)];
2182 sprintf(userlog
, "Sent username \"%s\"", username
);
2184 if (flags
& FLAG_INTERACTIVE
&&
2185 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2186 strcat(userlog
, "\r\n");
2187 c_write_str(userlog
);
2194 tried_publickey
= tried_agent
= 0;
2195 tis_auth_refused
= ccard_auth_refused
= 0;
2196 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2198 if (!rsakey_pubblob(cfg
.keyfile
, &publickey_blob
, &publickey_bloblen
))
2199 publickey_blob
= NULL
;
2201 publickey_blob
= NULL
;
2203 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2204 static char password
[100];
2205 static char prompt
[200];
2208 static int pwpkt_type
;
2209 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2211 if (agent_exists() && !tried_agent
) {
2213 * Attempt RSA authentication using Pageant.
2215 static unsigned char request
[5], *response
, *p
;
2216 static int responselen
;
2217 static int i
, nkeys
;
2218 static int authed
= FALSE
;
2222 logevent("Pageant is running. Requesting keys.");
2224 /* Request the keys held by the agent. */
2225 PUT_32BIT(request
, 1);
2226 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2227 agent_query(request
, 5, &r
, &responselen
);
2228 response
= (unsigned char *) r
;
2229 if (response
&& responselen
>= 5 &&
2230 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2232 nkeys
= GET_32BIT(p
);
2236 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2239 for (i
= 0; i
< nkeys
; i
++) {
2240 static struct RSAKey key
;
2241 static Bignum challenge
;
2242 static char *commentp
;
2243 static int commentlen
;
2247 sprintf(buf
, "Trying Pageant key #%d", i
);
2250 if (publickey_blob
&&
2251 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
2252 logevent("This key matches configured key file");
2253 tried_publickey
= 1;
2256 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2257 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2258 commentlen
= GET_32BIT(p
);
2262 send_packet(SSH1_CMSG_AUTH_RSA
,
2263 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2265 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2266 logevent("Key refused");
2269 logevent("Received RSA challenge");
2270 ssh1_read_bignum(pktin
.body
, &challenge
);
2272 char *agentreq
, *q
, *ret
;
2275 len
= 1 + 4; /* message type, bit count */
2276 len
+= ssh1_bignum_length(key
.exponent
);
2277 len
+= ssh1_bignum_length(key
.modulus
);
2278 len
+= ssh1_bignum_length(challenge
);
2279 len
+= 16; /* session id */
2280 len
+= 4; /* response format */
2281 agentreq
= smalloc(4 + len
);
2282 PUT_32BIT(agentreq
, len
);
2284 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2285 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2287 q
+= ssh1_write_bignum(q
, key
.exponent
);
2288 q
+= ssh1_write_bignum(q
, key
.modulus
);
2289 q
+= ssh1_write_bignum(q
, challenge
);
2290 memcpy(q
, session_id
, 16);
2292 PUT_32BIT(q
, 1); /* response format */
2293 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2297 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2298 logevent("Sending Pageant's response");
2299 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2300 PKT_DATA
, ret
+ 5, 16,
2304 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2306 ("Pageant's response accepted");
2307 if (flags
& FLAG_VERBOSE
) {
2309 ("Authenticated using RSA key \"");
2310 c_write(commentp
, commentlen
);
2311 c_write_str("\" from agent\r\n");
2316 ("Pageant's response not accepted");
2319 ("Pageant failed to answer challenge");
2323 logevent("No reply received from Pageant");
2326 freebn(key
.exponent
);
2327 freebn(key
.modulus
);
2336 if (*cfg
.keyfile
&& !tried_publickey
)
2337 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2339 if (cfg
.try_tis_auth
&&
2340 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2341 !tis_auth_refused
) {
2342 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2343 logevent("Requested TIS authentication");
2344 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2346 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2347 logevent("TIS authentication declined");
2348 if (flags
& FLAG_INTERACTIVE
)
2349 c_write_str("TIS authentication refused.\r\n");
2350 tis_auth_refused
= 1;
2353 int challengelen
= ((pktin
.body
[0] << 24) |
2354 (pktin
.body
[1] << 16) |
2355 (pktin
.body
[2] << 8) |
2357 logevent("Received TIS challenge");
2358 if (challengelen
> sizeof(prompt
) - 1)
2359 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2360 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2361 /* Prompt heuristic comes from OpenSSH */
2362 strncpy(prompt
+ challengelen
,
2363 memchr(prompt
, '\n', challengelen
) ?
2364 "": "\r\nResponse: ",
2365 (sizeof prompt
) - challengelen
);
2366 prompt
[(sizeof prompt
) - 1] = '\0';
2369 if (cfg
.try_tis_auth
&&
2370 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2371 !ccard_auth_refused
) {
2372 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2373 logevent("Requested CryptoCard authentication");
2374 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2376 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2377 logevent("CryptoCard authentication declined");
2378 c_write_str("CryptoCard authentication refused.\r\n");
2379 ccard_auth_refused
= 1;
2382 int challengelen
= ((pktin
.body
[0] << 24) |
2383 (pktin
.body
[1] << 16) |
2384 (pktin
.body
[2] << 8) |
2386 logevent("Received CryptoCard challenge");
2387 if (challengelen
> sizeof(prompt
) - 1)
2388 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2389 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2390 strncpy(prompt
+ challengelen
,
2391 memchr(prompt
, '\n', challengelen
) ?
2392 "" : "\r\nResponse: ",
2393 sizeof(prompt
) - challengelen
);
2394 prompt
[sizeof(prompt
) - 1] = '\0';
2397 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2398 sprintf(prompt
, "%.90s@%.90s's password: ",
2399 username
, savedhost
);
2401 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2402 char *comment
= NULL
;
2403 if (flags
& FLAG_VERBOSE
)
2404 c_write_str("Trying public key authentication.\r\n");
2405 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2406 if (flags
& FLAG_VERBOSE
)
2407 c_write_str("No passphrase required.\r\n");
2410 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2415 * Show password prompt, having first obtained it via a TIS
2416 * or CryptoCard exchange if we're doing TIS or CryptoCard
2420 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2422 * get_line failed to get a password (for example
2423 * because one was supplied on the command line
2424 * which has already failed to work). Terminate.
2426 send_packet(SSH1_MSG_DISCONNECT
,
2427 PKT_STR
, "No more passwords available to try",
2429 connection_fatal("Unable to authenticate");
2430 ssh_state
= SSH_STATE_CLOSED
;
2434 /* Prompt may have come from server. We've munged it a bit, so
2435 * we know it to be zero-terminated at least once. */
2436 c_write_untrusted(prompt
, strlen(prompt
));
2440 crWaitUntil(!ispkt
);
2442 switch (c
= *in
++) {
2463 if (pos
< sizeof(password
)-1)
2464 password
[pos
++] = c
;
2468 c_write_str("\r\n");
2472 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2474 * Try public key authentication with the specified
2477 static struct RSAKey pubkey
;
2478 static Bignum challenge
, response
;
2480 static unsigned char buffer
[32];
2482 tried_publickey
= 1;
2483 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2485 c_write_str("Couldn't load private key from ");
2486 c_write_str(cfg
.keyfile
);
2487 c_write_str(".\r\n");
2488 continue; /* go and try password */
2491 c_write_str("Wrong passphrase.\r\n");
2492 tried_publickey
= 0;
2493 continue; /* try again */
2497 * Send a public key attempt.
2499 send_packet(SSH1_CMSG_AUTH_RSA
,
2500 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2503 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2504 c_write_str("Server refused our public key.\r\n");
2505 continue; /* go and try password */
2507 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2508 bombout(("Bizarre response to offer of public key"));
2511 ssh1_read_bignum(pktin
.body
, &challenge
);
2512 response
= rsadecrypt(challenge
, &pubkey
);
2513 freebn(pubkey
.private_exponent
); /* burn the evidence */
2515 for (i
= 0; i
< 32; i
++) {
2516 buffer
[i
] = bignum_byte(response
, 31 - i
);
2520 MD5Update(&md5c
, buffer
, 32);
2521 MD5Update(&md5c
, session_id
, 16);
2522 MD5Final(buffer
, &md5c
);
2524 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2525 PKT_DATA
, buffer
, 16, PKT_END
);
2528 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2529 if (flags
& FLAG_VERBOSE
)
2531 ("Failed to authenticate with our public key.\r\n");
2532 continue; /* go and try password */
2533 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2535 ("Bizarre response to RSA authentication response"));
2539 break; /* we're through! */
2541 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2543 * Defence against traffic analysis: we send a
2544 * whole bunch of packets containing strings of
2545 * different lengths. One of these strings is the
2546 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2547 * The others are all random data in
2548 * SSH1_MSG_IGNORE packets. This way a passive
2549 * listener can't tell which is the password, and
2550 * hence can't deduce the password length.
2552 * Anybody with a password length greater than 16
2553 * bytes is going to have enough entropy in their
2554 * password that a listener won't find it _that_
2555 * much help to know how long it is. So what we'll
2558 * - if password length < 16, we send 15 packets
2559 * containing string lengths 1 through 15
2561 * - otherwise, we let N be the nearest multiple
2562 * of 8 below the password length, and send 8
2563 * packets containing string lengths N through
2564 * N+7. This won't obscure the order of
2565 * magnitude of the password length, but it will
2566 * introduce a bit of extra uncertainty.
2568 * A few servers (the old 1.2.18 through 1.2.22)
2569 * can't deal with SSH1_MSG_IGNORE. For these
2570 * servers, we need an alternative defence. We make
2571 * use of the fact that the password is interpreted
2572 * as a C string: so we can append a NUL, then some
2575 * One server (a Cisco one) can deal with neither
2576 * SSH1_MSG_IGNORE _nor_ a padded password string.
2577 * For this server we are left with no defences
2578 * against password length sniffing.
2580 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2582 * The server can deal with SSH1_MSG_IGNORE, so
2583 * we can use the primary defence.
2585 int bottom
, top
, pwlen
, i
;
2588 pwlen
= strlen(password
);
2590 bottom
= 0; /* zero length passwords are OK! :-) */
2593 bottom
= pwlen
& ~7;
2597 assert(pwlen
>= bottom
&& pwlen
<= top
);
2599 randomstr
= smalloc(top
+ 1);
2601 for (i
= bottom
; i
<= top
; i
++) {
2603 defer_packet(pwpkt_type
, PKT_STR
, password
,
2606 for (j
= 0; j
< i
; j
++) {
2608 randomstr
[j
] = random_byte();
2609 } while (randomstr
[j
] == '\0');
2611 randomstr
[i
] = '\0';
2612 defer_packet(SSH1_MSG_IGNORE
,
2613 PKT_STR
, randomstr
, PKT_END
);
2616 logevent("Sending password with camouflage packets");
2617 ssh_pkt_defersend();
2619 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2621 * The server can't deal with SSH1_MSG_IGNORE
2622 * but can deal with padded passwords, so we
2623 * can use the secondary defence.
2629 len
= strlen(password
);
2630 if (len
< sizeof(string
)) {
2632 strcpy(string
, password
);
2633 len
++; /* cover the zero byte */
2634 while (len
< sizeof(string
)) {
2635 string
[len
++] = (char) random_byte();
2640 logevent("Sending length-padded password");
2641 send_packet(pwpkt_type
, PKT_INT
, len
,
2642 PKT_DATA
, s
, len
, PKT_END
);
2645 * The server has _both_
2646 * BUG_CHOKES_ON_SSH1_IGNORE and
2647 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2648 * therefore nothing we can do.
2651 len
= strlen(password
);
2652 logevent("Sending unpadded password");
2653 send_packet(pwpkt_type
, PKT_INT
, len
,
2654 PKT_DATA
, password
, len
, PKT_END
);
2657 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2660 logevent("Sent password");
2661 memset(password
, 0, strlen(password
));
2663 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2664 if (flags
& FLAG_VERBOSE
)
2665 c_write_str("Access denied\r\n");
2666 logevent("Authentication refused");
2667 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2668 logevent("Received disconnect request");
2669 ssh_state
= SSH_STATE_CLOSED
;
2671 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2672 bombout(("Strange packet received, type %d", pktin
.type
));
2677 logevent("Authentication successful");
2682 void sshfwd_close(struct ssh_channel
*c
)
2684 if (c
&& !c
->closes
) {
2686 * If the channel's remoteid is -1, we have sent
2687 * CHANNEL_OPEN for this channel, but it hasn't even been
2688 * acknowledged by the server. So we must set a close flag
2689 * on it now, and then when the server acks the channel
2690 * open, we can close it then.
2692 if (c
->remoteid
!= -1) {
2693 if (ssh_version
== 1) {
2694 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2697 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2698 ssh2_pkt_adduint32(c
->remoteid
);
2703 if (c
->type
== CHAN_X11
) {
2705 logevent("Forwarded X11 connection terminated");
2706 } else if (c
->type
== CHAN_SOCKDATA
||
2707 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2709 logevent("Forwarded port closed");
2714 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2716 if (ssh_version
== 1) {
2717 send_packet(SSH1_MSG_CHANNEL_DATA
,
2718 PKT_INT
, c
->remoteid
,
2719 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2721 * In SSH1 we can return 0 here - implying that forwarded
2722 * connections are never individually throttled - because
2723 * the only circumstance that can cause throttling will be
2724 * the whole SSH connection backing up, in which case
2725 * _everything_ will be throttled as a whole.
2729 ssh2_add_channel_data(c
, buf
, len
);
2730 return ssh2_try_send(c
);
2734 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2736 if (ssh_version
== 1) {
2737 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2738 c
->v
.v1
.throttling
= 0;
2742 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2746 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2752 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2755 if (ssh_state
== SSH_STATE_CLOSED
)
2758 if (cfg
.agentfwd
&& agent_exists()) {
2759 logevent("Requesting agent forwarding");
2760 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2764 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2765 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2766 bombout(("Protocol confusion"));
2768 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2769 logevent("Agent forwarding refused");
2771 logevent("Agent forwarding enabled");
2772 ssh_agentfwd_enabled
= TRUE
;
2776 if (cfg
.x11_forward
) {
2777 char proto
[20], data
[64];
2778 logevent("Requesting X11 forwarding");
2779 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2780 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2781 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2782 PKT_STR
, proto
, PKT_STR
, data
,
2783 PKT_INT
, 0, PKT_END
);
2785 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2786 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2791 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2792 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2793 bombout(("Protocol confusion"));
2795 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2796 logevent("X11 forwarding refused");
2798 logevent("X11 forwarding enabled");
2799 ssh_X11_fwd_enabled
= TRUE
;
2807 char sports
[256], dports
[256], host
[256];
2810 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2811 /* Add port forwardings. */
2816 while (*e
&& *e
!= '\t')
2822 while (*e
&& *e
!= ':')
2832 dport
= atoi(dports
);
2833 sport
= atoi(sports
);
2834 if (sport
&& dport
) {
2836 pfd_addforward(host
, dport
, sport
);
2837 sprintf(buf
, "Local port %d forwarding to %s:%d",
2838 sport
, host
, dport
);
2841 struct ssh_rportfwd
*pf
;
2842 pf
= smalloc(sizeof(*pf
));
2843 strcpy(pf
->dhost
, host
);
2845 if (add234(ssh_rportfwds
, pf
) != pf
) {
2847 "Duplicate remote port forwarding to %s:%d",
2852 sprintf(buf
, "Requesting remote port %d forward to %s:%d",
2853 sport
, host
, dport
);
2855 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2867 send_packet(SSH1_CMSG_REQUEST_PTY
,
2868 PKT_STR
, cfg
.termtype
,
2869 PKT_INT
, rows
, PKT_INT
, cols
,
2870 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2871 ssh_state
= SSH_STATE_INTERMED
;
2875 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2876 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2877 bombout(("Protocol confusion"));
2879 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2880 c_write_str("Server refused to allocate pty\r\n");
2881 ssh_editing
= ssh_echoing
= 1;
2883 logevent("Allocated pty");
2885 ssh_editing
= ssh_echoing
= 1;
2888 if (cfg
.compression
) {
2889 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2893 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2894 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2895 bombout(("Protocol confusion"));
2897 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2898 c_write_str("Server refused to compress\r\n");
2900 logevent("Started compression");
2901 ssh1_compressing
= TRUE
;
2902 zlib_compress_init();
2903 zlib_decompress_init();
2907 * Start the shell or command.
2909 * Special case: if the first-choice command is an SSH2
2910 * subsystem (hence not usable here) and the second choice
2911 * exists, we fall straight back to that.
2914 char *cmd
= cfg
.remote_cmd_ptr
;
2916 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
2917 cmd
= cfg
.remote_cmd_ptr2
;
2918 ssh_fallback_cmd
= TRUE
;
2921 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2923 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2924 logevent("Started session");
2927 ssh_state
= SSH_STATE_SESSION
;
2931 ssh_special(TS_EOF
);
2933 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
2935 ssh_channels
= newtree234(ssh_channelcmp
);
2939 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2940 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2941 long len
= GET_32BIT(pktin
.body
);
2943 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2944 pktin
.body
+ 4, len
);
2945 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2946 ssh1_stdout_throttling
= 1;
2949 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2950 ssh_state
= SSH_STATE_CLOSED
;
2951 logevent("Received disconnect request");
2953 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2954 /* Remote side is trying to open a channel to talk to our
2955 * X-Server. Give them back a local channel number. */
2956 struct ssh_channel
*c
;
2958 logevent("Received X11 connect request");
2959 /* Refuse if X11 forwarding is disabled. */
2960 if (!ssh_X11_fwd_enabled
) {
2961 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2962 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2963 logevent("Rejected X11 connect request");
2965 c
= smalloc(sizeof(struct ssh_channel
));
2967 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2968 logevent("opening X11 forward connection failed");
2970 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2971 PKT_INT
, GET_32BIT(pktin
.body
),
2975 ("opening X11 forward connection succeeded");
2976 c
->remoteid
= GET_32BIT(pktin
.body
);
2977 c
->localid
= alloc_channel_id();
2979 c
->v
.v1
.throttling
= 0;
2980 c
->type
= CHAN_X11
; /* identify channel type */
2981 add234(ssh_channels
, c
);
2982 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2983 PKT_INT
, c
->remoteid
, PKT_INT
,
2984 c
->localid
, PKT_END
);
2985 logevent("Opened X11 forward channel");
2988 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2989 /* Remote side is trying to open a channel to talk to our
2990 * agent. Give them back a local channel number. */
2991 struct ssh_channel
*c
;
2993 /* Refuse if agent forwarding is disabled. */
2994 if (!ssh_agentfwd_enabled
) {
2995 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2996 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2998 c
= smalloc(sizeof(struct ssh_channel
));
2999 c
->remoteid
= GET_32BIT(pktin
.body
);
3000 c
->localid
= alloc_channel_id();
3002 c
->v
.v1
.throttling
= 0;
3003 c
->type
= CHAN_AGENT
; /* identify channel type */
3004 c
->u
.a
.lensofar
= 0;
3005 add234(ssh_channels
, c
);
3006 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3007 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3010 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3011 /* Remote side is trying to open a channel to talk to a
3012 * forwarded port. Give them back a local channel number. */
3013 struct ssh_channel
*c
;
3014 struct ssh_rportfwd pf
;
3016 char host
[256], buf
[1024];
3018 c
= smalloc(sizeof(struct ssh_channel
));
3020 hostsize
= GET_32BIT(pktin
.body
+4);
3021 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
3022 if (h
+1 < host
+sizeof(host
))
3027 port
= GET_32BIT(p
);
3029 strcpy(pf
.dhost
, host
);
3032 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
3033 sprintf(buf
, "Rejected remote port open request for %s:%d",
3036 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3037 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3039 sprintf(buf
, "Received remote port open request for %s:%d",
3042 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3045 sprintf(buf
, "Port open failed: %s", e
);
3048 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3049 PKT_INT
, GET_32BIT(pktin
.body
),
3052 c
->remoteid
= GET_32BIT(pktin
.body
);
3053 c
->localid
= alloc_channel_id();
3055 c
->v
.v1
.throttling
= 0;
3056 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3057 add234(ssh_channels
, c
);
3058 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3059 PKT_INT
, c
->remoteid
, PKT_INT
,
3060 c
->localid
, PKT_END
);
3061 logevent("Forwarded port opened successfully");
3065 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3066 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3067 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3068 struct ssh_channel
*c
;
3070 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3071 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3072 c
->remoteid
= localid
;
3073 c
->type
= CHAN_SOCKDATA
;
3074 c
->v
.v1
.throttling
= 0;
3075 pfd_confirm(c
->u
.pfd
.s
);
3078 if (c
&& c
->closes
) {
3080 * We have a pending close on this channel,
3081 * which we decided on before the server acked
3082 * the channel open. So now we know the
3083 * remoteid, we can close it again.
3085 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
3089 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3090 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3091 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3092 struct ssh_channel
*c
;
3094 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3095 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3096 logevent("Forwarded connection refused by server");
3097 pfd_close(c
->u
.pfd
.s
);
3098 del234(ssh_channels
, c
);
3102 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3103 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3104 /* Remote side closes a channel. */
3105 unsigned i
= GET_32BIT(pktin
.body
);
3106 struct ssh_channel
*c
;
3107 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3111 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3112 if (!(c
->closes
& closetype
))
3113 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
3115 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3116 logevent("Forwarded X11 connection terminated");
3117 assert(c
->u
.x11
.s
!= NULL
);
3118 x11_close(c
->u
.x11
.s
);
3121 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3122 logevent("Forwarded port closed");
3123 assert(c
->u
.pfd
.s
!= NULL
);
3124 pfd_close(c
->u
.pfd
.s
);
3127 c
->closes
|= closetype
;
3128 if (c
->closes
== 3) {
3129 del234(ssh_channels
, c
);
3133 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3134 /* Data sent down one of our channels. */
3135 int i
= GET_32BIT(pktin
.body
);
3136 int len
= GET_32BIT(pktin
.body
+ 4);
3137 unsigned char *p
= pktin
.body
+ 8;
3138 struct ssh_channel
*c
;
3139 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3144 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3147 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3150 /* Data for an agent message. Buffer it. */
3152 if (c
->u
.a
.lensofar
< 4) {
3153 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3154 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3158 c
->u
.a
.lensofar
+= l
;
3160 if (c
->u
.a
.lensofar
== 4) {
3162 4 + GET_32BIT(c
->u
.a
.msglen
);
3163 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3164 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3166 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3168 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3170 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3174 c
->u
.a
.lensofar
+= l
;
3176 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3177 void *reply
, *sentreply
;
3179 agent_query(c
->u
.a
.message
,
3180 c
->u
.a
.totallen
, &reply
,
3185 /* Fake SSH_AGENT_FAILURE. */
3186 sentreply
= "\0\0\0\1\5";
3189 send_packet(SSH1_MSG_CHANNEL_DATA
,
3190 PKT_INT
, c
->remoteid
,
3192 PKT_DATA
, sentreply
, replylen
,
3196 sfree(c
->u
.a
.message
);
3197 c
->u
.a
.lensofar
= 0;
3200 bufsize
= 0; /* agent channels never back up */
3203 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3204 c
->v
.v1
.throttling
= 1;
3208 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3209 /* may be from EXEC_SHELL on some servers */
3210 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3211 /* may be from EXEC_SHELL on some servers
3212 * if no pty is available or in other odd cases. Ignore */
3213 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3215 ssh_exitcode
= GET_32BIT(pktin
.body
);
3216 sprintf(buf
, "Server sent command exit status %d",
3219 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3221 * In case `helpful' firewalls or proxies tack
3222 * extra human-readable text on the end of the
3223 * session which we might mistake for another
3224 * encrypted packet, we close the session once
3225 * we've sent EXIT_CONFIRMATION.
3227 ssh_state
= SSH_STATE_CLOSED
;
3230 bombout(("Strange packet received: type %d", pktin
.type
));
3235 int len
= min(inlen
, 512);
3236 send_packet(SSH1_CMSG_STDIN_DATA
,
3237 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3248 * Utility routine for decoding comma-separated strings in KEXINIT.
3250 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3252 int needlen
= strlen(needle
);
3255 * Is it at the start of the string?
3257 if (haylen
>= needlen
&& /* haystack is long enough */
3258 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3259 (haylen
== needlen
|| haystack
[needlen
] == ',')
3260 /* either , or EOS follows */
3264 * If not, search for the next comma and resume after that.
3265 * If no comma found, terminate.
3267 while (haylen
> 0 && *haystack
!= ',')
3268 haylen
--, haystack
++;
3271 haylen
--, haystack
++; /* skip over comma itself */
3276 * SSH2 key creation method.
3278 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3282 /* First 20 bytes. */
3285 SHA_Bytes(&s
, H
, 20);
3286 SHA_Bytes(&s
, &chr
, 1);
3287 SHA_Bytes(&s
, sessid
, 20);
3288 SHA_Final(&s
, keyspace
);
3289 /* Next 20 bytes. */
3292 SHA_Bytes(&s
, H
, 20);
3293 SHA_Bytes(&s
, keyspace
, 20);
3294 SHA_Final(&s
, keyspace
+ 20);
3298 * Handle the SSH2 transport layer.
3300 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3302 static int i
, j
, len
, nbits
, pbits
, warn
;
3304 static Bignum p
, g
, e
, f
, K
;
3305 static int kex_init_value
, kex_reply_value
;
3306 static const struct ssh_mac
**maclist
;
3308 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3309 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3310 static const struct ssh_mac
*csmac_tobe
= NULL
;
3311 static const struct ssh_mac
*scmac_tobe
= NULL
;
3312 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3313 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3314 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3315 static int hostkeylen
, siglen
;
3316 static void *hkey
; /* actual host key */
3317 static unsigned char exchange_hash
[20];
3318 static unsigned char keyspace
[40];
3319 static int n_preferred_ciphers
;
3320 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3321 static const struct ssh_compress
*preferred_comp
;
3322 static int cipherstr_started
;
3323 static int first_kex
;
3330 * Set up the preferred ciphers. (NULL => warn below here)
3332 n_preferred_ciphers
= 0;
3333 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3334 switch (cfg
.ssh_cipherlist
[i
]) {
3335 case CIPHER_BLOWFISH
:
3336 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3337 n_preferred_ciphers
++;
3340 if (cfg
.ssh2_des_cbc
) {
3341 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3342 n_preferred_ciphers
++;
3346 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3347 n_preferred_ciphers
++;
3350 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3351 n_preferred_ciphers
++;
3354 /* Flag for later. Don't bother if it's the last in
3356 if (i
< CIPHER_MAX
- 1) {
3357 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3358 n_preferred_ciphers
++;
3365 * Set up preferred compression.
3367 if (cfg
.compression
)
3368 preferred_comp
= &ssh_zlib
;
3370 preferred_comp
= &ssh_comp_none
;
3373 * Be prepared to work around the buggy MAC problem.
3375 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3376 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3378 maclist
= macs
, nmacs
= lenof(macs
);
3382 * Construct and send our key exchange packet.
3384 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3385 for (i
= 0; i
< 16; i
++)
3386 ssh2_pkt_addbyte((unsigned char) random_byte());
3387 /* List key exchange algorithms. */
3388 ssh2_pkt_addstring_start();
3389 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3390 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3391 if (i
< lenof(kex_algs
) - 1)
3392 ssh2_pkt_addstring_str(",");
3394 /* List server host key algorithms. */
3395 ssh2_pkt_addstring_start();
3396 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3397 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3398 if (i
< lenof(hostkey_algs
) - 1)
3399 ssh2_pkt_addstring_str(",");
3401 /* List client->server encryption algorithms. */
3402 ssh2_pkt_addstring_start();
3403 cipherstr_started
= 0;
3404 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3405 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3406 if (!c
) continue; /* warning flag */
3407 for (j
= 0; j
< c
->nciphers
; j
++) {
3408 if (cipherstr_started
)
3409 ssh2_pkt_addstring_str(",");
3410 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3411 cipherstr_started
= 1;
3414 /* List server->client encryption algorithms. */
3415 ssh2_pkt_addstring_start();
3416 cipherstr_started
= 0;
3417 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3418 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3419 if (!c
) continue; /* warning flag */
3420 for (j
= 0; j
< c
->nciphers
; j
++) {
3421 if (cipherstr_started
)
3422 ssh2_pkt_addstring_str(",");
3423 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3424 cipherstr_started
= 1;
3427 /* List client->server MAC algorithms. */
3428 ssh2_pkt_addstring_start();
3429 for (i
= 0; i
< nmacs
; i
++) {
3430 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3432 ssh2_pkt_addstring_str(",");
3434 /* List server->client MAC algorithms. */
3435 ssh2_pkt_addstring_start();
3436 for (i
= 0; i
< nmacs
; i
++) {
3437 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3439 ssh2_pkt_addstring_str(",");
3441 /* List client->server compression algorithms. */
3442 ssh2_pkt_addstring_start();
3443 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3444 const struct ssh_compress
*c
=
3445 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3446 ssh2_pkt_addstring_str(c
->name
);
3447 if (i
< lenof(compressions
))
3448 ssh2_pkt_addstring_str(",");
3450 /* List server->client compression algorithms. */
3451 ssh2_pkt_addstring_start();
3452 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3453 const struct ssh_compress
*c
=
3454 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3455 ssh2_pkt_addstring_str(c
->name
);
3456 if (i
< lenof(compressions
))
3457 ssh2_pkt_addstring_str(",");
3459 /* List client->server languages. Empty list. */
3460 ssh2_pkt_addstring_start();
3461 /* List server->client languages. Empty list. */
3462 ssh2_pkt_addstring_start();
3463 /* First KEX packet does _not_ follow, because we're not that brave. */
3464 ssh2_pkt_addbool(FALSE
);
3466 ssh2_pkt_adduint32(0);
3468 exhash
= exhashbase
;
3469 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3475 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3478 * Now examine the other side's KEXINIT to see what we're up
3481 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3482 bombout(("expected key exchange packet from server"));
3487 cscipher_tobe
= NULL
;
3488 sccipher_tobe
= NULL
;
3493 pktin
.savedpos
+= 16; /* skip garbage cookie */
3494 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3495 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3496 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3501 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3502 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3503 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3504 hostkey
= hostkey_algs
[i
];
3508 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3510 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3511 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3515 for (j
= 0; j
< c
->nciphers
; j
++) {
3516 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3517 cscipher_tobe
= c
->list
[j
];
3522 if (cscipher_tobe
) {
3524 askcipher(cscipher_tobe
->name
, 1);
3528 if (!cscipher_tobe
) {
3529 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3533 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3535 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3536 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3540 for (j
= 0; j
< c
->nciphers
; j
++) {
3541 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3542 sccipher_tobe
= c
->list
[j
];
3547 if (sccipher_tobe
) {
3549 askcipher(sccipher_tobe
->name
, 2);
3553 if (!sccipher_tobe
) {
3554 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3558 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3559 for (i
= 0; i
< nmacs
; i
++) {
3560 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3561 csmac_tobe
= maclist
[i
];
3565 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3566 for (i
= 0; i
< nmacs
; i
++) {
3567 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3568 scmac_tobe
= maclist
[i
];
3572 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3573 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3574 const struct ssh_compress
*c
=
3575 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3576 if (in_commasep_string(c
->name
, str
, len
)) {
3581 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3582 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3583 const struct ssh_compress
*c
=
3584 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3585 if (in_commasep_string(c
->name
, str
, len
)) {
3592 * Work out the number of bits of key we will need from the key
3593 * exchange. We start with the maximum key length of either
3599 csbits
= cscipher_tobe
->keylen
;
3600 scbits
= sccipher_tobe
->keylen
;
3601 nbits
= (csbits
> scbits ? csbits
: scbits
);
3603 /* The keys only have 160-bit entropy, since they're based on
3604 * a SHA-1 hash. So cap the key size at 160 bits. */
3609 * If we're doing Diffie-Hellman group exchange, start by
3610 * requesting a group.
3612 if (kex
== &ssh_diffiehellman_gex
) {
3613 logevent("Doing Diffie-Hellman group exchange");
3614 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3616 * Work out how big a DH group we will need to allow that
3619 pbits
= 512 << ((nbits
- 1) / 64);
3620 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3621 ssh2_pkt_adduint32(pbits
);
3625 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3626 bombout(("expected key exchange group packet from server"));
3629 p
= ssh2_pkt_getmp();
3630 g
= ssh2_pkt_getmp();
3631 dh_setup_group(p
, g
);
3632 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3633 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3635 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3637 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3638 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3641 logevent("Doing Diffie-Hellman key exchange");
3643 * Now generate and send e for Diffie-Hellman.
3645 e
= dh_create_e(nbits
* 2);
3646 ssh2_pkt_init(kex_init_value
);
3651 if (pktin
.type
!= kex_reply_value
) {
3652 bombout(("expected key exchange reply packet from server"));
3655 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3656 f
= ssh2_pkt_getmp();
3657 ssh2_pkt_getstring(&sigdata
, &siglen
);
3661 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3662 if (kex
== &ssh_diffiehellman_gex
) {
3663 sha_uint32(&exhash
, pbits
);
3664 sha_mpint(&exhash
, p
);
3665 sha_mpint(&exhash
, g
);
3667 sha_mpint(&exhash
, e
);
3668 sha_mpint(&exhash
, f
);
3669 sha_mpint(&exhash
, K
);
3670 SHA_Final(&exhash
, exchange_hash
);
3675 debug(("Exchange hash is:\n"));
3676 dmemdump(exchange_hash
, 20);
3679 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3681 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3682 bombout(("Server's host key did not match the signature supplied"));
3687 * Authenticate remote host: verify host key. (We've already
3688 * checked the signature of the exchange hash.)
3690 keystr
= hostkey
->fmtkey(hkey
);
3691 fingerprint
= hostkey
->fingerprint(hkey
);
3692 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3693 keystr
, fingerprint
);
3694 if (first_kex
) { /* don't bother logging this in rekeys */
3695 logevent("Host key fingerprint is:");
3696 logevent(fingerprint
);
3700 hostkey
->freekey(hkey
);
3703 * Send SSH2_MSG_NEWKEYS.
3705 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3709 * Expect SSH2_MSG_NEWKEYS from server.
3712 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3713 bombout(("expected new-keys packet from server"));
3718 * Create and initialise session keys.
3720 cscipher
= cscipher_tobe
;
3721 sccipher
= sccipher_tobe
;
3724 cscomp
= cscomp_tobe
;
3725 sccomp
= sccomp_tobe
;
3726 cscomp
->compress_init();
3727 sccomp
->decompress_init();
3729 * Set IVs after keys. Here we use the exchange hash from the
3730 * _first_ key exchange.
3733 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3734 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3735 cscipher
->setcskey(keyspace
);
3736 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3737 sccipher
->setsckey(keyspace
);
3738 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3739 cscipher
->setcsiv(keyspace
);
3740 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3741 sccipher
->setsciv(keyspace
);
3742 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3743 csmac
->setcskey(keyspace
);
3744 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3745 scmac
->setsckey(keyspace
);
3748 * If this is the first key exchange phase, we must pass the
3749 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3750 * wants to see it but because it will need time to initialise
3751 * itself before it sees an actual packet. In subsequent key
3752 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3753 * it would only confuse the layer above.
3761 * Now we're encrypting. Begin returning 1 to the protocol main
3762 * function so that other things can run on top of the
3763 * transport. If we ever see a KEXINIT, we must go back to the
3766 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3769 logevent("Server initiated key re-exchange");
3770 goto begin_key_exchange
;
3776 * Add data to an SSH2 channel output buffer.
3778 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3781 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3785 * Attempt to send data on an SSH2 channel.
3787 static int ssh2_try_send(struct ssh_channel
*c
)
3789 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3792 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3793 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3794 len
= c
->v
.v2
.remwindow
;
3795 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3796 len
= c
->v
.v2
.remmaxpkt
;
3797 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3798 ssh2_pkt_adduint32(c
->remoteid
);
3799 ssh2_pkt_addstring_start();
3800 ssh2_pkt_addstring_data(data
, len
);
3802 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3803 c
->v
.v2
.remwindow
-= len
;
3807 * After having sent as much data as we can, return the amount
3810 return bufchain_size(&c
->v
.v2
.outbuffer
);
3814 * Potentially enlarge the window on an SSH2 channel.
3816 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3819 * Never send WINDOW_ADJUST for a channel that the remote side
3820 * already thinks it's closed; there's no point, since it won't
3821 * be sending any more data anyway.
3826 if (newwin
> c
->v
.v2
.locwindow
) {
3827 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3828 ssh2_pkt_adduint32(c
->remoteid
);
3829 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3831 c
->v
.v2
.locwindow
= newwin
;
3836 * Handle the SSH2 userauth and connection layers.
3838 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3841 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3843 AUTH_KEYBOARD_INTERACTIVE
3847 AUTH_TYPE_PUBLICKEY
,
3848 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3849 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3851 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3852 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3854 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3855 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3856 static int kbd_inter_running
;
3857 static int we_are_in
;
3858 static int num_prompts
, echo
;
3859 static char username
[100];
3860 static char pwprompt
[200];
3861 static char password
[100];
3862 static void *publickey_blob
;
3863 static int publickey_bloblen
;
3868 * Request userauth protocol, and await a response to it.
3870 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3871 ssh2_pkt_addstring("ssh-userauth");
3873 crWaitUntilV(ispkt
);
3874 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3875 bombout(("Server refused user authentication protocol"));
3880 * We repeat this whole loop, including the username prompt,
3881 * until we manage a successful authentication. If the user
3882 * types the wrong _password_, they are sent back to the
3883 * beginning to try another username. (If they specify a
3884 * username in the config, they are never asked, even if they
3885 * do give a wrong password.)
3887 * I think this best serves the needs of
3889 * - the people who have no configuration, no keys, and just
3890 * want to try repeated (username,password) pairs until they
3891 * type both correctly
3893 * - people who have keys and configuration but occasionally
3894 * need to fall back to passwords
3896 * - people with a key held in Pageant, who might not have
3897 * logged in to a particular machine before; so they want to
3898 * type a username, and then _either_ their key will be
3899 * accepted, _or_ they will type a password. If they mistype
3900 * the username they will want to be able to get back and
3912 if (*username
&& !cfg
.change_username
) {
3914 * We got a username last time round this loop, and
3915 * with change_username turned off we don't try to get
3918 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
3920 if (!ssh_get_line("login as: ",
3921 username
, sizeof(username
), FALSE
)) {
3923 * get_line failed to get a username.
3926 logevent("No username provided. Abandoning session.");
3927 ssh_state
= SSH_STATE_CLOSED
;
3931 c_write_str("login as: ");
3934 crWaitUntilV(!ispkt
);
3936 switch (c
= *in
++) {
3945 c_write_str("\b \b");
3952 c_write_str("\b \b");
3962 if (((c
>= ' ' && c
<= '~') ||
3963 ((unsigned char) c
>= 160))
3964 && pos
< sizeof(username
)-1) {
3965 username
[pos
++] = c
;
3972 c_write_str("\r\n");
3973 username
[strcspn(username
, "\n\r")] = '\0';
3976 strncpy(username
, cfg
.username
, 99);
3977 username
[99] = '\0';
3978 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3979 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3985 * Send an authentication request using method "none": (a)
3986 * just in case it succeeds, and (b) so that we know what
3987 * authentication methods we can usefully try next.
3989 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
3991 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3992 ssh2_pkt_addstring(username
);
3993 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3994 ssh2_pkt_addstring("none"); /* method */
3996 type
= AUTH_TYPE_NONE
;
4000 tried_pubkey_config
= FALSE
;
4001 tried_agent
= FALSE
;
4002 tried_keyb_inter
= FALSE
;
4003 kbd_inter_running
= FALSE
;
4004 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4006 publickey_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4007 &publickey_bloblen
);
4009 publickey_blob
= NULL
;
4013 * Wait for the result of the last authentication request.
4016 crWaitUntilV(ispkt
);
4017 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4021 * Don't show the banner if we're operating in
4022 * non-verbose non-interactive mode. (It's probably
4023 * a script, which means nobody will read the
4024 * banner _anyway_, and moreover the printing of
4025 * the banner will screw up processing on the
4026 * output of (say) plink.)
4028 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4029 ssh2_pkt_getstring(&banner
, &size
);
4031 c_write_untrusted(banner
, size
);
4033 crWaitUntilV(ispkt
);
4035 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4036 logevent("Access granted");
4041 if (kbd_inter_running
&&
4042 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4044 * This is a further prompt in keyboard-interactive
4045 * authentication. Do nothing.
4047 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4048 bombout(("Strange packet received during authentication: type %d",
4056 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4057 * we can look at the string in it and know what we can
4058 * helpfully try next.
4060 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4063 ssh2_pkt_getstring(&methods
, &methlen
);
4064 kbd_inter_running
= FALSE
;
4065 if (!ssh2_pkt_getbool()) {
4067 * We have received an unequivocal Access
4068 * Denied. This can translate to a variety of
4071 * - if we'd just tried "none" authentication,
4072 * it's not worth printing anything at all
4074 * - if we'd just tried a public key _offer_,
4075 * the message should be "Server refused our
4076 * key" (or no message at all if the key
4077 * came from Pageant)
4079 * - if we'd just tried anything else, the
4080 * message really should be "Access denied".
4082 * Additionally, if we'd just tried password
4083 * authentication, we should break out of this
4084 * whole loop so as to go back to the username
4087 if (type
== AUTH_TYPE_NONE
) {
4089 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4090 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4091 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4092 c_write_str("Server refused our key\r\n");
4093 logevent("Server refused public key");
4094 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4095 /* server declined keyboard-interactive; ignore */
4097 c_write_str("Access denied\r\n");
4098 logevent("Access denied");
4099 if (type
== AUTH_TYPE_PASSWORD
) {
4105 c_write_str("Further authentication required\r\n");
4106 logevent("Further authentication required");
4110 in_commasep_string("publickey", methods
, methlen
);
4112 in_commasep_string("password", methods
, methlen
);
4113 can_keyb_inter
= cfg
.try_ki_auth
&&
4114 in_commasep_string("keyboard-interactive", methods
, methlen
);
4118 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4120 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
4122 * Attempt public-key authentication using Pageant.
4124 static unsigned char request
[5], *response
, *p
;
4125 static int responselen
;
4126 static int i
, nkeys
;
4127 static int authed
= FALSE
;
4130 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4134 logevent("Pageant is running. Requesting keys.");
4136 /* Request the keys held by the agent. */
4137 PUT_32BIT(request
, 1);
4138 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4139 agent_query(request
, 5, &r
, &responselen
);
4140 response
= (unsigned char *) r
;
4141 if (response
&& responselen
>= 5 &&
4142 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4144 nkeys
= GET_32BIT(p
);
4148 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
4151 for (i
= 0; i
< nkeys
; i
++) {
4152 static char *pkblob
, *alg
, *commentp
;
4153 static int pklen
, alglen
, commentlen
;
4154 static int siglen
, retlen
, len
;
4155 static char *q
, *agentreq
, *ret
;
4160 sprintf(buf
, "Trying Pageant key #%d", i
);
4163 pklen
= GET_32BIT(p
);
4165 if (publickey_blob
&&
4166 pklen
== publickey_bloblen
&&
4167 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
4168 logevent("This key matches configured key file");
4169 tried_pubkey_config
= 1;
4173 alglen
= GET_32BIT(pkblob
);
4175 commentlen
= GET_32BIT(p
);
4179 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4180 ssh2_pkt_addstring(username
);
4181 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4182 ssh2_pkt_addstring("publickey"); /* method */
4183 ssh2_pkt_addbool(FALSE
); /* no signature included */
4184 ssh2_pkt_addstring_start();
4185 ssh2_pkt_addstring_data(alg
, alglen
);
4186 ssh2_pkt_addstring_start();
4187 ssh2_pkt_addstring_data(pkblob
, pklen
);
4190 crWaitUntilV(ispkt
);
4191 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4192 logevent("Key refused");
4196 if (flags
& FLAG_VERBOSE
) {
4198 ("Authenticating with public key \"");
4199 c_write(commentp
, commentlen
);
4200 c_write_str("\" from agent\r\n");
4204 * Server is willing to accept the key.
4205 * Construct a SIGN_REQUEST.
4207 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4208 ssh2_pkt_addstring(username
);
4209 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4210 ssh2_pkt_addstring("publickey"); /* method */
4211 ssh2_pkt_addbool(TRUE
);
4212 ssh2_pkt_addstring_start();
4213 ssh2_pkt_addstring_data(alg
, alglen
);
4214 ssh2_pkt_addstring_start();
4215 ssh2_pkt_addstring_data(pkblob
, pklen
);
4217 siglen
= pktout
.length
- 5 + 4 + 20;
4218 len
= 1; /* message type */
4219 len
+= 4 + pklen
; /* key blob */
4220 len
+= 4 + siglen
; /* data to sign */
4221 len
+= 4; /* flags */
4222 agentreq
= smalloc(4 + len
);
4223 PUT_32BIT(agentreq
, len
);
4225 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4226 PUT_32BIT(q
, pklen
);
4228 memcpy(q
, pkblob
, pklen
);
4230 PUT_32BIT(q
, siglen
);
4232 /* Now the data to be signed... */
4235 memcpy(q
, ssh2_session_id
, 20);
4237 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4238 q
+= pktout
.length
- 5;
4239 /* And finally the (zero) flags word. */
4241 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4245 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4246 logevent("Sending Pageant's response");
4247 ssh2_pkt_addstring_start();
4248 ssh2_pkt_addstring_data(ret
+ 9,
4256 ("Pageant failed to answer challenge");
4266 if (!method
&& can_pubkey
&& *cfg
.keyfile
4267 && !tried_pubkey_config
) {
4268 unsigned char *pub_blob
;
4269 char *algorithm
, *comment
;
4272 tried_pubkey_config
= TRUE
;
4274 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4277 * Try the public key supplied in the configuration.
4279 * First, offer the public blob to see if the server is
4280 * willing to accept it.
4282 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4285 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4286 ssh2_pkt_addstring(username
);
4287 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4288 ssh2_pkt_addstring("publickey"); /* method */
4289 ssh2_pkt_addbool(FALSE
); /* no signature included */
4290 ssh2_pkt_addstring(algorithm
);
4291 ssh2_pkt_addstring_start();
4292 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4294 logevent("Offered public key"); /* FIXME */
4296 crWaitUntilV(ispkt
);
4297 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4299 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4300 continue; /* key refused; give up on it */
4303 logevent("Offer of public key accepted");
4305 * Actually attempt a serious authentication using
4308 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4310 "Passphrase for key \"%.100s\": ",
4316 c_write_str("Authenticating with public key \"");
4317 c_write_str(comment
);
4318 c_write_str("\"\r\n");
4319 method
= AUTH_PUBLICKEY_FILE
;
4323 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4324 method
= AUTH_KEYBOARD_INTERACTIVE
;
4325 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4326 tried_keyb_inter
= TRUE
;
4328 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4330 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4331 ssh2_pkt_addstring(username
);
4332 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4333 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4334 ssh2_pkt_addstring(""); /* lang */
4335 ssh2_pkt_addstring("");
4338 crWaitUntilV(ispkt
);
4339 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4340 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4342 logevent("Keyboard-interactive authentication refused");
4343 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4347 kbd_inter_running
= TRUE
;
4350 if (kbd_inter_running
) {
4351 method
= AUTH_KEYBOARD_INTERACTIVE
;
4352 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4353 tried_keyb_inter
= TRUE
;
4355 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4357 /* We've got packet with that "interactive" info
4358 dump banners, and set its prompt as ours */
4360 char *name
, *inst
, *lang
, *prompt
;
4361 int name_len
, inst_len
, lang_len
, prompt_len
;
4362 ssh2_pkt_getstring(&name
, &name_len
);
4363 ssh2_pkt_getstring(&inst
, &inst_len
);
4364 ssh2_pkt_getstring(&lang
, &lang_len
);
4366 c_write_untrusted(name
, name_len
);
4368 c_write_untrusted(inst
, inst_len
);
4369 num_prompts
= ssh2_pkt_getuint32();
4371 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4372 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4373 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4374 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4377 echo
= ssh2_pkt_getbool();
4381 if (!method
&& can_passwd
) {
4382 method
= AUTH_PASSWORD
;
4383 ssh_pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4384 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4391 if (!ssh_get_line(pwprompt
, password
,
4392 sizeof(password
), TRUE
)) {
4394 * get_line failed to get a password (for
4395 * example because one was supplied on the
4396 * command line which has already failed to
4399 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4400 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4402 ("No more passwords available to try");
4403 ssh2_pkt_addstring("en"); /* language tag */
4405 connection_fatal("Unable to authenticate");
4406 ssh_state
= SSH_STATE_CLOSED
;
4413 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4418 crWaitUntilV(!ispkt
);
4420 switch (c
= *in
++) {
4441 if (pos
< sizeof(password
)-1)
4442 password
[pos
++] = c
;
4446 c_write_str("\r\n");
4450 if (method
== AUTH_PUBLICKEY_FILE
) {
4452 * We have our passphrase. Now try the actual authentication.
4454 struct ssh2_userkey
*key
;
4456 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4457 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4458 if (key
== SSH2_WRONG_PASSPHRASE
) {
4459 c_write_str("Wrong passphrase\r\n");
4460 tried_pubkey_config
= FALSE
;
4462 c_write_str("Unable to load private key\r\n");
4463 tried_pubkey_config
= TRUE
;
4465 /* Send a spurious AUTH_NONE to return to the top. */
4466 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4467 ssh2_pkt_addstring(username
);
4468 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4469 ssh2_pkt_addstring("none"); /* method */
4471 type
= AUTH_TYPE_NONE
;
4473 unsigned char *blob
, *sigdata
;
4474 int blob_len
, sigdata_len
;
4477 * We have loaded the private key and the server
4478 * has announced that it's willing to accept it.
4479 * Hallelujah. Generate a signature and send it.
4481 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4482 ssh2_pkt_addstring(username
);
4483 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4484 ssh2_pkt_addstring("publickey"); /* method */
4485 ssh2_pkt_addbool(TRUE
);
4486 ssh2_pkt_addstring(key
->alg
->name
);
4487 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4488 ssh2_pkt_addstring_start();
4489 ssh2_pkt_addstring_data(blob
, blob_len
);
4493 * The data to be signed is:
4497 * followed by everything so far placed in the
4500 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4501 sigdata
= smalloc(sigdata_len
);
4502 PUT_32BIT(sigdata
, 20);
4503 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4504 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4507 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4509 ssh2_pkt_addstring_start();
4510 ssh2_pkt_addstring_data(blob
, blob_len
);
4515 type
= AUTH_TYPE_PUBLICKEY
;
4517 } else if (method
== AUTH_PASSWORD
) {
4519 * We send the password packet lumped tightly together with
4520 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4521 * string long enough to make the total length of the two
4522 * packets constant. This should ensure that a passive
4523 * listener doing traffic analyis can't work out the length
4526 * For this to work, we need an assumption about the
4527 * maximum length of the password packet. I think 256 is
4528 * pretty conservative. Anyone using a password longer than
4529 * that probably doesn't have much to worry about from
4530 * people who find out how long their password is!
4532 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4533 ssh2_pkt_addstring(username
);
4534 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4535 ssh2_pkt_addstring("password");
4536 ssh2_pkt_addbool(FALSE
);
4537 ssh2_pkt_addstring(password
);
4540 * We'll include a string that's an exact multiple of the
4541 * cipher block size. If the cipher is NULL for some
4542 * reason, we don't do this trick at all because we gain
4548 stringlen
= (256 - deferred_len
);
4549 stringlen
+= cscipher
->blksize
- 1;
4550 stringlen
-= (stringlen
% cscipher
->blksize
);
4553 * Temporarily disable actual compression,
4554 * so we can guarantee to get this string
4555 * exactly the length we want it. The
4556 * compression-disabling routine should
4557 * return an integer indicating how many
4558 * bytes we should adjust our string length
4561 stringlen
-= cscomp
->disable_compression();
4563 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4564 ssh2_pkt_addstring_start();
4565 for (i
= 0; i
< stringlen
; i
++) {
4566 char c
= (char) random_byte();
4567 ssh2_pkt_addstring_data(&c
, 1);
4571 ssh_pkt_defersend();
4572 logevent("Sent password");
4573 type
= AUTH_TYPE_PASSWORD
;
4574 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4575 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4576 ssh2_pkt_adduint32(num_prompts
);
4577 ssh2_pkt_addstring(password
);
4578 memset(password
, 0, sizeof(password
));
4580 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4583 ("No supported authentication methods left to try!\r\n");
4585 ("No supported authentications offered. Disconnecting");
4586 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4587 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4589 ("No supported authentication methods available");
4590 ssh2_pkt_addstring("en"); /* language tag */
4592 ssh_state
= SSH_STATE_CLOSED
;
4596 } while (!we_are_in
);
4599 * Now we're authenticated for the connection protocol. The
4600 * connection protocol will automatically have started at this
4601 * point; there's no need to send SERVICE_REQUEST.
4605 * So now create a channel with a session in it.
4607 ssh_channels
= newtree234(ssh_channelcmp
);
4608 mainchan
= smalloc(sizeof(struct ssh_channel
));
4609 mainchan
->localid
= alloc_channel_id();
4610 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4611 ssh2_pkt_addstring("session");
4612 ssh2_pkt_adduint32(mainchan
->localid
);
4613 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4614 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4615 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4617 crWaitUntilV(ispkt
);
4618 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4619 bombout(("Server refused to open a session"));
4621 /* FIXME: error data comes back in FAILURE packet */
4623 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4624 bombout(("Server's channel confirmation cited wrong channel"));
4627 mainchan
->remoteid
= ssh2_pkt_getuint32();
4628 mainchan
->type
= CHAN_MAINSESSION
;
4629 mainchan
->closes
= 0;
4630 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4631 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4632 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4633 add234(ssh_channels
, mainchan
);
4634 logevent("Opened channel for session");
4637 * Potentially enable X11 forwarding.
4639 if (cfg
.x11_forward
) {
4640 char proto
[20], data
[64];
4641 logevent("Requesting X11 forwarding");
4642 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4643 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4644 ssh2_pkt_adduint32(mainchan
->remoteid
);
4645 ssh2_pkt_addstring("x11-req");
4646 ssh2_pkt_addbool(1); /* want reply */
4647 ssh2_pkt_addbool(0); /* many connections */
4648 ssh2_pkt_addstring(proto
);
4649 ssh2_pkt_addstring(data
);
4650 ssh2_pkt_adduint32(0); /* screen number */
4654 crWaitUntilV(ispkt
);
4655 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4656 unsigned i
= ssh2_pkt_getuint32();
4657 struct ssh_channel
*c
;
4658 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4660 continue; /* nonexistent channel */
4661 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4663 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4665 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4666 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4667 bombout(("Unexpected response to X11 forwarding request:"
4668 " packet type %d", pktin
.type
));
4671 logevent("X11 forwarding refused");
4673 logevent("X11 forwarding enabled");
4674 ssh_X11_fwd_enabled
= TRUE
;
4679 * Enable port forwardings.
4682 static char *e
; /* preserve across crReturn */
4686 char sports
[256], dports
[256], host
[256];
4689 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4690 /* Add port forwardings. */
4695 while (*e
&& *e
!= '\t')
4701 while (*e
&& *e
!= ':')
4711 dport
= atoi(dports
);
4712 sport
= atoi(sports
);
4713 if (sport
&& dport
) {
4715 pfd_addforward(host
, dport
, sport
);
4716 sprintf(buf
, "Local port %d forwarding to %s:%d",
4717 sport
, host
, dport
);
4720 struct ssh_rportfwd
*pf
;
4721 pf
= smalloc(sizeof(*pf
));
4722 strcpy(pf
->dhost
, host
);
4725 if (add234(ssh_rportfwds
, pf
) != pf
) {
4727 "Duplicate remote port forwarding to %s:%d",
4732 sprintf(buf
, "Requesting remote port %d (forwarded to %s:%d)",
4733 sport
, host
, dport
);
4735 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4736 ssh2_pkt_addstring("tcpip-forward");
4737 ssh2_pkt_addbool(1);/* want reply */
4738 if (cfg
.rport_acceptall
)
4739 ssh2_pkt_addstring("0.0.0.0");
4741 ssh2_pkt_addstring("127.0.0.1");
4742 ssh2_pkt_adduint32(sport
);
4746 crWaitUntilV(ispkt
);
4747 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4748 unsigned i
= ssh2_pkt_getuint32();
4749 struct ssh_channel
*c
;
4750 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4752 continue;/* nonexistent channel */
4753 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4755 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4757 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4758 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4759 bombout(("Unexpected response to port "
4760 "forwarding request: packet type %d",
4764 logevent("Server refused this port forwarding");
4766 logevent("Remote port forwarding enabled");
4775 * Potentially enable agent forwarding.
4777 if (cfg
.agentfwd
&& agent_exists()) {
4778 logevent("Requesting OpenSSH-style agent forwarding");
4779 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4780 ssh2_pkt_adduint32(mainchan
->remoteid
);
4781 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4782 ssh2_pkt_addbool(1); /* want reply */
4786 crWaitUntilV(ispkt
);
4787 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4788 unsigned i
= ssh2_pkt_getuint32();
4789 struct ssh_channel
*c
;
4790 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4792 continue; /* nonexistent channel */
4793 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4795 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4797 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4798 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4799 bombout(("Unexpected response to agent forwarding request:"
4800 " packet type %d", pktin
.type
));
4803 logevent("Agent forwarding refused");
4805 logevent("Agent forwarding enabled");
4806 ssh_agentfwd_enabled
= TRUE
;
4811 * Now allocate a pty for the session.
4814 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4815 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4816 ssh2_pkt_addstring("pty-req");
4817 ssh2_pkt_addbool(1); /* want reply */
4818 ssh2_pkt_addstring(cfg
.termtype
);
4819 ssh2_pkt_adduint32(cols
);
4820 ssh2_pkt_adduint32(rows
);
4821 ssh2_pkt_adduint32(0); /* pixel width */
4822 ssh2_pkt_adduint32(0); /* pixel height */
4823 ssh2_pkt_addstring_start();
4824 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4826 ssh_state
= SSH_STATE_INTERMED
;
4829 crWaitUntilV(ispkt
);
4830 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4831 unsigned i
= ssh2_pkt_getuint32();
4832 struct ssh_channel
*c
;
4833 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4835 continue; /* nonexistent channel */
4836 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4838 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4840 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4841 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4842 bombout(("Unexpected response to pty request:"
4843 " packet type %d", pktin
.type
));
4846 c_write_str("Server refused to allocate pty\r\n");
4847 ssh_editing
= ssh_echoing
= 1;
4849 logevent("Allocated pty");
4852 ssh_editing
= ssh_echoing
= 1;
4856 * Start a shell or a remote command. We may have to attempt
4857 * this twice if the config data has provided a second choice
4864 if (ssh_fallback_cmd
) {
4865 subsys
= cfg
.ssh_subsys2
;
4866 cmd
= cfg
.remote_cmd_ptr2
;
4868 subsys
= cfg
.ssh_subsys
;
4869 cmd
= cfg
.remote_cmd_ptr
;
4872 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4873 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4875 ssh2_pkt_addstring("subsystem");
4876 ssh2_pkt_addbool(1); /* want reply */
4877 ssh2_pkt_addstring(cmd
);
4879 ssh2_pkt_addstring("exec");
4880 ssh2_pkt_addbool(1); /* want reply */
4881 ssh2_pkt_addstring(cmd
);
4883 ssh2_pkt_addstring("shell");
4884 ssh2_pkt_addbool(1); /* want reply */
4888 crWaitUntilV(ispkt
);
4889 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4890 unsigned i
= ssh2_pkt_getuint32();
4891 struct ssh_channel
*c
;
4892 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4894 continue; /* nonexistent channel */
4895 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4897 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4898 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4899 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4900 bombout(("Unexpected response to shell/command request:"
4901 " packet type %d", pktin
.type
));
4905 * We failed to start the command. If this is the
4906 * fallback command, we really are finished; if it's
4907 * not, and if the fallback command exists, try falling
4908 * back to it before complaining.
4910 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
4911 logevent("Primary command failed; attempting fallback");
4912 ssh_fallback_cmd
= TRUE
;
4915 bombout(("Server refused to start a shell/command"));
4918 logevent("Started a shell/command");
4923 ssh_state
= SSH_STATE_SESSION
;
4927 ssh_special(TS_EOF
);
4932 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
4935 static int try_send
;
4939 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
4940 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
4943 unsigned i
= ssh2_pkt_getuint32();
4944 struct ssh_channel
*c
;
4945 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4947 continue; /* nonexistent channel */
4948 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
4949 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
4950 continue; /* extended but not stderr */
4951 ssh2_pkt_getstring(&data
, &length
);
4954 c
->v
.v2
.locwindow
-= length
;
4956 case CHAN_MAINSESSION
:
4958 from_backend(pktin
.type
==
4959 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
4963 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
4966 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
4969 while (length
> 0) {
4970 if (c
->u
.a
.lensofar
< 4) {
4971 int l
= min(4 - c
->u
.a
.lensofar
, length
);
4972 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
4976 c
->u
.a
.lensofar
+= l
;
4978 if (c
->u
.a
.lensofar
== 4) {
4980 4 + GET_32BIT(c
->u
.a
.msglen
);
4981 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
4982 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
4984 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
4986 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
4988 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
4992 c
->u
.a
.lensofar
+= l
;
4994 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
4995 void *reply
, *sentreply
;
4997 agent_query(c
->u
.a
.message
,
4998 c
->u
.a
.totallen
, &reply
,
5003 /* Fake SSH_AGENT_FAILURE. */
5004 sentreply
= "\0\0\0\1\5";
5007 ssh2_add_channel_data(c
, sentreply
,
5012 sfree(c
->u
.a
.message
);
5013 c
->u
.a
.lensofar
= 0;
5020 * If we are not buffering too much data,
5021 * enlarge the window again at the remote side.
5023 if (bufsize
< OUR_V2_WINSIZE
)
5024 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5026 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
5027 ssh_state
= SSH_STATE_CLOSED
;
5028 logevent("Received disconnect message");
5030 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5031 unsigned i
= ssh2_pkt_getuint32();
5032 struct ssh_channel
*c
;
5034 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5036 continue; /* nonexistent channel */
5038 if (c
->type
== CHAN_X11
) {
5040 * Remote EOF on an X11 channel means we should
5041 * wrap up and close the channel ourselves.
5043 x11_close(c
->u
.x11
.s
);
5045 } else if (c
->type
== CHAN_AGENT
) {
5047 } else if (c
->type
== CHAN_SOCKDATA
) {
5048 pfd_close(c
->u
.pfd
.s
);
5051 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5052 unsigned i
= ssh2_pkt_getuint32();
5053 struct ssh_channel
*c
;
5055 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5057 continue; /* nonexistent channel */
5058 /* Do pre-close processing on the channel. */
5060 case CHAN_MAINSESSION
:
5061 break; /* nothing to see here, move along */
5063 if (c
->u
.x11
.s
!= NULL
)
5064 x11_close(c
->u
.x11
.s
);
5071 if (c
->u
.pfd
.s
!= NULL
)
5072 pfd_close(c
->u
.pfd
.s
);
5076 if (c
->closes
== 0) {
5077 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5078 ssh2_pkt_adduint32(c
->remoteid
);
5081 del234(ssh_channels
, c
);
5082 bufchain_clear(&c
->v
.v2
.outbuffer
);
5086 * See if that was the last channel left open.
5088 if (count234(ssh_channels
) == 0) {
5091 * We used to send SSH_MSG_DISCONNECT here,
5092 * because I'd believed that _every_ conforming
5093 * SSH2 connection had to end with a disconnect
5094 * being sent by at least one side; apparently
5095 * I was wrong and it's perfectly OK to
5096 * unceremoniously slam the connection shut
5097 * when you're done, and indeed OpenSSH feels
5098 * this is more polite than sending a
5099 * DISCONNECT. So now we don't.
5101 logevent("All channels closed. Disconnecting");
5102 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5103 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5104 ssh2_pkt_addstring("All open channels closed");
5105 ssh2_pkt_addstring("en"); /* language tag */
5108 ssh_state
= SSH_STATE_CLOSED
;
5111 continue; /* remote sends close; ignore (FIXME) */
5112 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5113 unsigned i
= ssh2_pkt_getuint32();
5114 struct ssh_channel
*c
;
5115 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5117 continue; /* nonexistent channel */
5118 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5120 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5121 unsigned i
= ssh2_pkt_getuint32();
5122 struct ssh_channel
*c
;
5123 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5125 continue; /* nonexistent channel */
5126 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5127 continue; /* dunno why they're confirming this */
5128 c
->remoteid
= ssh2_pkt_getuint32();
5129 c
->type
= CHAN_SOCKDATA
;
5130 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
5131 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
5132 bufchain_init(&c
->v
.v2
.outbuffer
);
5134 pfd_confirm(c
->u
.pfd
.s
);
5137 * We have a pending close on this channel,
5138 * which we decided on before the server acked
5139 * the channel open. So now we know the
5140 * remoteid, we can close it again.
5142 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5143 ssh2_pkt_adduint32(c
->remoteid
);
5146 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5147 unsigned i
= ssh2_pkt_getuint32();
5148 struct ssh_channel
*c
;
5149 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5151 continue; /* nonexistent channel */
5152 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5153 continue; /* dunno why they're failing this */
5155 logevent("Forwarded connection refused by server");
5157 pfd_close(c
->u
.pfd
.s
);
5159 del234(ssh_channels
, c
);
5161 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5164 int typelen
, want_reply
;
5165 struct ssh_channel
*c
;
5167 localid
= ssh2_pkt_getuint32();
5168 ssh2_pkt_getstring(&type
, &typelen
);
5169 want_reply
= ssh2_pkt_getbool();
5172 * First, check that the channel exists. Otherwise,
5173 * we can instantly disconnect with a rude message.
5175 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
5178 sprintf(buf
, "Received channel request for nonexistent"
5179 " channel %d", localid
);
5181 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5182 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5183 ssh2_pkt_addstring(buf
);
5184 ssh2_pkt_addstring("en"); /* language tag */
5186 connection_fatal(buf
);
5187 ssh_state
= SSH_STATE_CLOSED
;
5192 * Having got the channel number, we now look at
5193 * the request type string to see if it's something
5196 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5198 /* We recognise "exit-status" on the primary channel. */
5200 ssh_exitcode
= ssh2_pkt_getuint32();
5201 sprintf(buf
, "Server sent command exit status %d",
5205 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS
);
5206 ssh2_pkt_adduint32(c
->remoteid
);
5211 * This is a channel request we don't know
5212 * about, so we now either ignore the request
5213 * or respond with CHANNEL_FAILURE, depending
5217 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
5218 ssh2_pkt_adduint32(c
->remoteid
);
5222 } else if (pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5224 int typelen
, want_reply
;
5226 ssh2_pkt_getstring(&type
, &typelen
);
5227 want_reply
= ssh2_pkt_getbool();
5230 * We currently don't support any global requests
5231 * at all, so we either ignore the request or
5232 * respond with REQUEST_FAILURE, depending on
5236 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
5239 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5243 struct ssh_channel
*c
;
5244 unsigned remid
, winsize
, pktsize
;
5245 ssh2_pkt_getstring(&type
, &typelen
);
5246 c
= smalloc(sizeof(struct ssh_channel
));
5248 remid
= ssh2_pkt_getuint32();
5249 winsize
= ssh2_pkt_getuint32();
5250 pktsize
= ssh2_pkt_getuint32();
5252 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5253 if (!ssh_X11_fwd_enabled
)
5254 error
= "X11 forwarding is not enabled";
5255 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
5257 error
= "Unable to open an X11 connection";
5261 } else if (typelen
== 15 &&
5262 !memcmp(type
, "forwarded-tcpip", 15)) {
5263 struct ssh_rportfwd pf
, *realpf
;
5266 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
5267 pf
.sport
= ssh2_pkt_getuint32();
5268 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
5269 if (realpf
== NULL
) {
5270 error
= "Remote port is not recognised";
5272 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5275 sprintf(buf
, "Received remote port open request for %s:%d",
5276 realpf
->dhost
, realpf
->dport
);
5279 sprintf(buf
, "Port open failed: %s", e
);
5281 error
= "Port open failed";
5283 logevent("Forwarded port opened successfully");
5284 c
->type
= CHAN_SOCKDATA
;
5287 } else if (typelen
== 22 &&
5288 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5289 if (!ssh_agentfwd_enabled
)
5290 error
= "Agent forwarding is not enabled";
5292 c
->type
= CHAN_AGENT
; /* identify channel type */
5293 c
->u
.a
.lensofar
= 0;
5296 error
= "Unsupported channel type requested";
5299 c
->remoteid
= remid
;
5301 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5302 ssh2_pkt_adduint32(c
->remoteid
);
5303 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5304 ssh2_pkt_addstring(error
);
5305 ssh2_pkt_addstring("en"); /* language tag */
5309 c
->localid
= alloc_channel_id();
5311 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5312 c
->v
.v2
.remwindow
= winsize
;
5313 c
->v
.v2
.remmaxpkt
= pktsize
;
5314 bufchain_init(&c
->v
.v2
.outbuffer
);
5315 add234(ssh_channels
, c
);
5316 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5317 ssh2_pkt_adduint32(c
->remoteid
);
5318 ssh2_pkt_adduint32(c
->localid
);
5319 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5320 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5324 bombout(("Strange packet received: type %d", pktin
.type
));
5329 * We have spare data. Add it to the channel buffer.
5331 ssh2_add_channel_data(mainchan
, in
, inlen
);
5336 struct ssh_channel
*c
;
5338 * Try to send data on all channels if we can.
5340 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5341 int bufsize
= ssh2_try_send(c
);
5344 case CHAN_MAINSESSION
:
5345 /* stdin need not receive an unthrottle
5346 * notification since it will be polled */
5349 x11_unthrottle(c
->u
.x11
.s
);
5352 /* agent sockets are request/response and need no
5353 * buffer management */
5356 pfd_unthrottle(c
->u
.pfd
.s
);
5368 * Handle the top-level SSH2 protocol.
5370 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5372 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5374 do_ssh2_authconn(in
, inlen
, ispkt
);
5378 * Called to set up the connection.
5380 * Returns an error message, or NULL on success.
5382 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5387 if (crypto_startup() == 0)
5388 return "Microsoft high encryption pack not installed!";
5394 ssh1_throttle_count
= 0;
5395 ssh_overall_bufsize
= 0;
5396 ssh_fallback_cmd
= 0;
5398 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5406 * Called to send data down the Telnet connection.
5408 static int ssh_send(char *buf
, int len
)
5410 if (s
== NULL
|| ssh_protocol
== NULL
)
5413 ssh_protocol(buf
, len
, 0);
5415 return ssh_sendbuffer();
5419 * Called to query the current amount of buffered stdin data.
5421 static int ssh_sendbuffer(void)
5425 if (s
== NULL
|| ssh_protocol
== NULL
)
5429 * If the SSH socket itself has backed up, add the total backup
5430 * size on that to any individual buffer on the stdin channel.
5433 if (ssh_throttled_all
)
5434 override_value
= ssh_overall_bufsize
;
5436 if (ssh_version
== 1) {
5437 return override_value
;
5438 } else if (ssh_version
== 2) {
5439 if (!mainchan
|| mainchan
->closes
> 0)
5440 return override_value
;
5442 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5449 * Called to set the size of the window from SSH's POV.
5451 static void ssh_size(void)
5453 switch (ssh_state
) {
5454 case SSH_STATE_BEFORE_SIZE
:
5455 case SSH_STATE_PREPACKET
:
5456 case SSH_STATE_CLOSED
:
5457 break; /* do nothing */
5458 case SSH_STATE_INTERMED
:
5459 size_needed
= TRUE
; /* buffer for later */
5461 case SSH_STATE_SESSION
:
5463 if (ssh_version
== 1) {
5464 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5465 PKT_INT
, rows
, PKT_INT
, cols
,
5466 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5468 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5469 ssh2_pkt_adduint32(mainchan
->remoteid
);
5470 ssh2_pkt_addstring("window-change");
5471 ssh2_pkt_addbool(0);
5472 ssh2_pkt_adduint32(cols
);
5473 ssh2_pkt_adduint32(rows
);
5474 ssh2_pkt_adduint32(0);
5475 ssh2_pkt_adduint32(0);
5484 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5485 * can send an EOF and collect resulting output (e.g. `plink
5488 static void ssh_special(Telnet_Special code
)
5490 if (code
== TS_EOF
) {
5491 if (ssh_state
!= SSH_STATE_SESSION
) {
5493 * Buffer the EOF in case we are pre-SESSION, so we can
5494 * send it as soon as we reach SESSION.
5500 if (ssh_version
== 1) {
5501 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5503 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5504 ssh2_pkt_adduint32(mainchan
->remoteid
);
5507 logevent("Sent EOF message");
5508 } else if (code
== TS_PING
) {
5509 if (ssh_state
== SSH_STATE_CLOSED
5510 || ssh_state
== SSH_STATE_PREPACKET
) return;
5511 if (ssh_version
== 1) {
5512 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5514 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5515 ssh2_pkt_addstring_start();
5523 void *new_sock_channel(Socket s
)
5525 struct ssh_channel
*c
;
5526 c
= smalloc(sizeof(struct ssh_channel
));
5529 c
->remoteid
= -1; /* to be set when open confirmed */
5530 c
->localid
= alloc_channel_id();
5532 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5534 add234(ssh_channels
, c
);
5540 * This is called when stdout/stderr (the entity to which
5541 * from_backend sends data) manages to clear some backlog.
5543 void ssh_unthrottle(int bufsize
)
5545 if (ssh_version
== 1) {
5546 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5547 ssh1_stdout_throttling
= 0;
5551 if (mainchan
&& mainchan
->closes
== 0)
5552 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5556 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5558 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5561 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5564 if (ssh_version
== 1) {
5565 send_packet(SSH1_MSG_PORT_OPEN
,
5566 PKT_INT
, c
->localid
,
5569 //PKT_STR, <org:orgport>,
5572 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5573 ssh2_pkt_addstring("direct-tcpip");
5574 ssh2_pkt_adduint32(c
->localid
);
5575 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5576 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5577 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5578 ssh2_pkt_addstring(hostname
);
5579 ssh2_pkt_adduint32(port
);
5581 * We make up values for the originator data; partly it's
5582 * too much hassle to keep track, and partly I'm not
5583 * convinced the server should be told details like that
5584 * about my local network configuration.
5586 ssh2_pkt_addstring("client-side-connection");
5587 ssh2_pkt_adduint32(0);
5593 static Socket
ssh_socket(void)
5598 static int ssh_sendok(void)
5603 static int ssh_ldisc(int option
)
5605 if (option
== LD_ECHO
)
5607 if (option
== LD_EDIT
)
5612 static int ssh_return_exitcode(void)
5614 return ssh_exitcode
;
5617 Backend ssh_backend
= {
5624 ssh_return_exitcode
,