18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
22 /* logevent, only printf-formatted. */
23 void logeventf(char *fmt
, ...)
29 vsprintf(stuff
, fmt
, ap
);
34 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
35 (s ? sk_close(s), s = NULL : 0), \
36 logeventf msg, connection_fatal msg )
38 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41 #define SSH1_CMSG_USER 4 /* 0x4 */
42 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
51 #define SSH1_SMSG_FAILURE 15 /* 0xf */
52 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55 #define SSH1_CMSG_EOF 19 /* 0x13 */
56 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67 #define SSH1_MSG_IGNORE 32 /* 0x20 */
68 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71 #define SSH1_MSG_DEBUG 36 /* 0x24 */
72 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
80 #define SSH1_AUTH_TIS 5 /* 0x5 */
81 #define SSH1_AUTH_CCARD 16 /* 0x10 */
83 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
84 /* Mask for protoflags we will echo back to server if seen */
85 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
87 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88 #define SSH2_MSG_IGNORE 2 /* 0x2 */
89 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90 #define SSH2_MSG_DEBUG 4 /* 0x4 */
91 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
94 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
107 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
109 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
128 #define SSH2_PKTCTX_DHGROUP1 0x0001
129 #define SSH2_PKTCTX_DHGEX 0x0002
130 #define SSH2_PKTCTX_PUBLICKEY 0x0010
131 #define SSH2_PKTCTX_PASSWORD 0x0020
132 #define SSH2_PKTCTX_KBDINTER 0x0040
133 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
135 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
151 static const char *const ssh2_disconnect_reasons
[] = {
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
170 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
175 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
178 * Various remote-bug flags.
180 #define BUG_CHOKES_ON_SSH1_IGNORE 1
181 #define BUG_SSH2_HMAC 2
182 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
183 #define BUG_CHOKES_ON_RSA 8
184 #define BUG_SSH2_RSA_PADDING 16
186 static int ssh_pkt_ctx
= 0;
188 #define translate(x) if (type == x) return #x
189 #define translatec(x,ctx) if (type == x && (ssh_pkt_ctx & ctx)) return #x
190 char *ssh1_pkt_type(int type
)
192 translate(SSH1_MSG_DISCONNECT
);
193 translate(SSH1_SMSG_PUBLIC_KEY
);
194 translate(SSH1_CMSG_SESSION_KEY
);
195 translate(SSH1_CMSG_USER
);
196 translate(SSH1_CMSG_AUTH_RSA
);
197 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE
);
198 translate(SSH1_CMSG_AUTH_RSA_RESPONSE
);
199 translate(SSH1_CMSG_AUTH_PASSWORD
);
200 translate(SSH1_CMSG_REQUEST_PTY
);
201 translate(SSH1_CMSG_WINDOW_SIZE
);
202 translate(SSH1_CMSG_EXEC_SHELL
);
203 translate(SSH1_CMSG_EXEC_CMD
);
204 translate(SSH1_SMSG_SUCCESS
);
205 translate(SSH1_SMSG_FAILURE
);
206 translate(SSH1_CMSG_STDIN_DATA
);
207 translate(SSH1_SMSG_STDOUT_DATA
);
208 translate(SSH1_SMSG_STDERR_DATA
);
209 translate(SSH1_CMSG_EOF
);
210 translate(SSH1_SMSG_EXIT_STATUS
);
211 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
);
212 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE
);
213 translate(SSH1_MSG_CHANNEL_DATA
);
214 translate(SSH1_MSG_CHANNEL_CLOSE
);
215 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
);
216 translate(SSH1_SMSG_X11_OPEN
);
217 translate(SSH1_CMSG_PORT_FORWARD_REQUEST
);
218 translate(SSH1_MSG_PORT_OPEN
);
219 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING
);
220 translate(SSH1_SMSG_AGENT_OPEN
);
221 translate(SSH1_MSG_IGNORE
);
222 translate(SSH1_CMSG_EXIT_CONFIRMATION
);
223 translate(SSH1_CMSG_X11_REQUEST_FORWARDING
);
224 translate(SSH1_CMSG_AUTH_RHOSTS_RSA
);
225 translate(SSH1_MSG_DEBUG
);
226 translate(SSH1_CMSG_REQUEST_COMPRESSION
);
227 translate(SSH1_CMSG_AUTH_TIS
);
228 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE
);
229 translate(SSH1_CMSG_AUTH_TIS_RESPONSE
);
230 translate(SSH1_CMSG_AUTH_CCARD
);
231 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE
);
232 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE
);
235 char *ssh2_pkt_type(int type
)
237 translate(SSH2_MSG_DISCONNECT
);
238 translate(SSH2_MSG_IGNORE
);
239 translate(SSH2_MSG_UNIMPLEMENTED
);
240 translate(SSH2_MSG_DEBUG
);
241 translate(SSH2_MSG_SERVICE_REQUEST
);
242 translate(SSH2_MSG_SERVICE_ACCEPT
);
243 translate(SSH2_MSG_KEXINIT
);
244 translate(SSH2_MSG_NEWKEYS
);
245 translatec(SSH2_MSG_KEXDH_INIT
, SSH2_PKTCTX_DHGROUP1
);
246 translatec(SSH2_MSG_KEXDH_REPLY
, SSH2_PKTCTX_DHGROUP1
);
247 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST
, SSH2_PKTCTX_DHGEX
);
248 translatec(SSH2_MSG_KEX_DH_GEX_GROUP
, SSH2_PKTCTX_DHGEX
);
249 translatec(SSH2_MSG_KEX_DH_GEX_INIT
, SSH2_PKTCTX_DHGEX
);
250 translatec(SSH2_MSG_KEX_DH_GEX_REPLY
, SSH2_PKTCTX_DHGEX
);
251 translate(SSH2_MSG_USERAUTH_REQUEST
);
252 translate(SSH2_MSG_USERAUTH_FAILURE
);
253 translate(SSH2_MSG_USERAUTH_SUCCESS
);
254 translate(SSH2_MSG_USERAUTH_BANNER
);
255 translatec(SSH2_MSG_USERAUTH_PK_OK
, SSH2_PKTCTX_PUBLICKEY
);
256 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
, SSH2_PKTCTX_PASSWORD
);
257 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST
, SSH2_PKTCTX_KBDINTER
);
258 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE
, SSH2_PKTCTX_KBDINTER
);
259 translate(SSH2_MSG_GLOBAL_REQUEST
);
260 translate(SSH2_MSG_REQUEST_SUCCESS
);
261 translate(SSH2_MSG_REQUEST_FAILURE
);
262 translate(SSH2_MSG_CHANNEL_OPEN
);
263 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
264 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
265 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
266 translate(SSH2_MSG_CHANNEL_DATA
);
267 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
268 translate(SSH2_MSG_CHANNEL_EOF
);
269 translate(SSH2_MSG_CHANNEL_CLOSE
);
270 translate(SSH2_MSG_CHANNEL_REQUEST
);
271 translate(SSH2_MSG_CHANNEL_SUCCESS
);
272 translate(SSH2_MSG_CHANNEL_FAILURE
);
278 #define GET_32BIT(cp) \
279 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
280 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
281 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
282 ((unsigned long)(unsigned char)(cp)[3]))
284 #define PUT_32BIT(cp, value) { \
285 (cp)[0] = (unsigned char)((value) >> 24); \
286 (cp)[1] = (unsigned char)((value) >> 16); \
287 (cp)[2] = (unsigned char)((value) >> 8); \
288 (cp)[3] = (unsigned char)(value); }
290 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
292 /* Coroutine mechanics for the sillier bits of the code */
293 #define crBegin1 static int crLine = 0;
294 #define crBegin2 switch(crLine) { case 0:;
295 #define crBegin crBegin1; crBegin2;
296 #define crFinish(z) } crLine = 0; return (z)
297 #define crFinishV } crLine = 0; return
298 #define crReturn(z) \
300 crLine=__LINE__; return (z); case __LINE__:;\
304 crLine=__LINE__; return; case __LINE__:;\
306 #define crStop(z) do{ crLine = 0; return (z); }while(0)
307 #define crStopV do{ crLine = 0; return; }while(0)
308 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
309 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
311 extern char *x11_init(Socket
*, char *, void *);
312 extern void x11_close(Socket
);
313 extern int x11_send(Socket
, char *, int);
314 extern void x11_invent_auth(char *, int, char *, int);
315 extern void x11_unthrottle(Socket s
);
316 extern void x11_override_throttle(Socket s
, int enable
);
318 extern char *pfd_newconnect(Socket
* s
, char *hostname
, int port
, void *c
);
319 extern char *pfd_addforward(char *desthost
, int destport
, int port
);
320 extern void pfd_close(Socket s
);
321 extern int pfd_send(Socket s
, char *data
, int len
);
322 extern void pfd_confirm(Socket s
);
323 extern void pfd_unthrottle(Socket s
);
324 extern void pfd_override_throttle(Socket s
, int enable
);
326 static void ssh2_pkt_init(int pkt_type
);
327 static void ssh2_pkt_addbool(unsigned char value
);
328 static void ssh2_pkt_adduint32(unsigned long value
);
329 static void ssh2_pkt_addstring_start(void);
330 static void ssh2_pkt_addstring_str(char *data
);
331 static void ssh2_pkt_addstring_data(char *data
, int len
);
332 static void ssh2_pkt_addstring(char *data
);
333 static char *ssh2_mpint_fmt(Bignum b
, int *len
);
334 static void ssh2_pkt_addmp(Bignum b
);
335 static int ssh2_pkt_construct(void);
336 static void ssh2_pkt_send(void);
339 * Buffer management constants. There are several of these for
340 * various different purposes:
342 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
343 * on a local data stream before we throttle the whole SSH
344 * connection (in SSH1 only). Throttling the whole connection is
345 * pretty drastic so we set this high in the hope it won't
348 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
349 * on the SSH connection itself before we defensively throttle
350 * _all_ local data streams. This is pretty drastic too (though
351 * thankfully unlikely in SSH2 since the window mechanism should
352 * ensure that the server never has any need to throttle its end
353 * of the connection), so we set this high as well.
355 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
359 #define SSH1_BUFFER_LIMIT 32768
360 #define SSH_MAX_BACKLOG 32768
361 #define OUR_V2_WINSIZE 16384
363 const static struct ssh_kex
*kex_algs
[] = {
364 &ssh_diffiehellman_gex
,
368 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
370 static void nullmac_key(unsigned char *key
)
373 static void nullmac_generate(unsigned char *blk
, int len
,
377 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
)
381 const static struct ssh_mac ssh_mac_none
= {
382 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
384 const static struct ssh_mac
*macs
[] = {
385 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
387 const static struct ssh_mac
*buggymacs
[] = {
388 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
391 static void ssh_comp_none_init(void)
394 static int ssh_comp_none_block(unsigned char *block
, int len
,
395 unsigned char **outblock
, int *outlen
)
399 static int ssh_comp_none_disable(void)
403 const static struct ssh_compress ssh_comp_none
= {
405 ssh_comp_none_init
, ssh_comp_none_block
,
406 ssh_comp_none_init
, ssh_comp_none_block
,
407 ssh_comp_none_disable
409 extern const struct ssh_compress ssh_zlib
;
410 const static struct ssh_compress
*compressions
[] = {
411 &ssh_zlib
, &ssh_comp_none
414 enum { /* channel types */
419 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
423 * 2-3-4 tree storing channels.
426 unsigned remoteid
, localid
;
430 struct ssh1_data_channel
{
433 struct ssh2_data_channel
{
435 unsigned remwindow
, remmaxpkt
;
440 struct ssh_agent_channel
{
441 unsigned char *message
;
442 unsigned char msglen
[4];
443 int lensofar
, totallen
;
445 struct ssh_x11_channel
{
448 struct ssh_pfd_channel
{
455 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
456 * 2 use this structure in different ways, reflecting SSH 2's
457 * altogether saner approach to port forwarding.
459 * In SSH 1, you arrange a remote forwarding by sending the server
460 * the remote port number, and the local destination host:port.
461 * When a connection comes in, the server sends you back that
462 * host:port pair, and you connect to it. This is a ready-made
463 * security hole if you're not on the ball: a malicious server
464 * could send you back _any_ host:port pair, so if you trustingly
465 * connect to the address it gives you then you've just opened the
466 * entire inside of your corporate network just by connecting
467 * through it to a dodgy SSH server. Hence, we must store a list of
468 * host:port pairs we _are_ trying to forward to, and reject a
469 * connection request from the server if it's not in the list.
471 * In SSH 2, each side of the connection minds its own business and
472 * doesn't send unnecessary information to the other. You arrange a
473 * remote forwarding by sending the server just the remote port
474 * number. When a connection comes in, the server tells you which
475 * of its ports was connected to; and _you_ have to remember what
476 * local host:port pair went with that port number.
478 * Hence: in SSH 1 this structure stores host:port pairs we intend
479 * to allow connections to, and is indexed by those host:port
480 * pairs. In SSH 2 it stores a mapping from source port to
481 * destination host:port pair, and is indexed by source port.
483 struct ssh_rportfwd
{
484 unsigned sport
, dport
;
497 static SHA_State exhash
, exhashbase
;
499 static Socket s
= NULL
;
501 static unsigned char session_key
[32];
502 static int ssh1_compressing
;
503 static int ssh1_remote_protoflags
;
504 static int ssh1_local_protoflags
;
505 static int ssh_agentfwd_enabled
;
506 static int ssh_X11_fwd_enabled
;
507 static int ssh_remote_bugs
;
508 static const struct ssh_cipher
*cipher
= NULL
;
509 static const struct ssh2_cipher
*cscipher
= NULL
;
510 static const struct ssh2_cipher
*sccipher
= NULL
;
511 static const struct ssh_mac
*csmac
= NULL
;
512 static const struct ssh_mac
*scmac
= NULL
;
513 static const struct ssh_compress
*cscomp
= NULL
;
514 static const struct ssh_compress
*sccomp
= NULL
;
515 static const struct ssh_kex
*kex
= NULL
;
516 static const struct ssh_signkey
*hostkey
= NULL
;
517 static unsigned char ssh2_session_id
[20];
519 static char *savedhost
;
520 static int savedport
;
521 static int ssh_send_ok
;
522 static int ssh_echoing
, ssh_editing
;
524 static tree234
*ssh_channels
; /* indexed by local id */
525 static struct ssh_channel
*mainchan
; /* primary session channel */
526 static int ssh_exitcode
= -1;
528 static tree234
*ssh_rportfwds
;
532 SSH_STATE_BEFORE_SIZE
,
536 } ssh_state
= SSH_STATE_PREPACKET
;
538 static int size_needed
= FALSE
, eof_needed
= FALSE
;
540 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
541 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
542 static unsigned char *deferred_send_data
= NULL
;
543 static int deferred_len
= 0, deferred_size
= 0;
546 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
547 * that fails. This variable is the means by which scp.c can reach
548 * into the SSH code and find out which one it got.
550 int ssh_fallback_cmd
= 0;
552 static int ssh_version
;
553 static int ssh1_throttle_count
;
554 static int ssh_overall_bufsize
;
555 static int ssh_throttled_all
;
556 static int ssh1_stdout_throttling
;
557 static void (*ssh_protocol
) (unsigned char *in
, int inlen
, int ispkt
);
558 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
559 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
560 static void ssh_size(void);
561 static void ssh_special(Telnet_Special
);
562 static int ssh2_try_send(struct ssh_channel
*c
);
563 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
565 static void ssh_throttle_all(int enable
, int bufsize
);
566 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
567 static int (*s_rdpkt
) (unsigned char **data
, int *datalen
);
568 static int ssh_sendbuffer(void);
570 static struct rdpkt1_state_tag
{
571 long len
, pad
, biglen
, to_read
;
572 unsigned long realcrc
, gotcrc
;
578 static struct rdpkt2_state_tag
{
579 long len
, pad
, payload
, packetlen
, maclen
;
582 unsigned long incoming_sequence
;
585 static int ssh_channelcmp(void *av
, void *bv
)
587 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
588 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
589 if (a
->localid
< b
->localid
)
591 if (a
->localid
> b
->localid
)
595 static int ssh_channelfind(void *av
, void *bv
)
597 unsigned *a
= (unsigned *) av
;
598 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
606 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
608 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
609 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
611 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
612 return i
< 0 ?
-1 : +1;
613 if (a
->dport
> b
->dport
)
615 if (a
->dport
< b
->dport
)
620 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
622 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
623 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
625 if (a
->sport
> b
->sport
)
627 if (a
->sport
< b
->sport
)
632 static int alloc_channel_id(void)
634 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
635 unsigned low
, high
, mid
;
637 struct ssh_channel
*c
;
640 * First-fit allocation of channel numbers: always pick the
641 * lowest unused one. To do this, binary-search using the
642 * counted B-tree to find the largest channel ID which is in a
643 * contiguous sequence from the beginning. (Precisely
644 * everything in that sequence must have ID equal to its tree
645 * index plus CHANNEL_NUMBER_OFFSET.)
647 tsize
= count234(ssh_channels
);
651 while (high
- low
> 1) {
652 mid
= (high
+ low
) / 2;
653 c
= index234(ssh_channels
, mid
);
654 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
655 low
= mid
; /* this one is fine */
657 high
= mid
; /* this one is past it */
660 * Now low points to either -1, or the tree index of the
661 * largest ID in the initial sequence.
664 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
665 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
667 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
670 static void c_write(char *buf
, int len
)
672 if ((flags
& FLAG_STDERR
)) {
674 for (i
= 0; i
< len
; i
++)
676 fputc(buf
[i
], stderr
);
679 from_backend(1, buf
, len
);
682 static void c_write_untrusted(char *buf
, int len
)
685 for (i
= 0; i
< len
; i
++) {
688 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
693 static void c_write_str(char *buf
)
695 c_write(buf
, strlen(buf
));
699 * Collect incoming data in the incoming packet buffer.
700 * Decipher and verify the packet when it is completely read.
701 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
702 * Update the *data and *datalen variables.
703 * Return the additional nr of bytes needed, or 0 when
704 * a complete packet is available.
706 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
708 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
717 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
718 while ((*datalen
) == 0)
720 st
->len
= (st
->len
<< 8) + **data
;
721 (*data
)++, (*datalen
)--;
724 st
->pad
= 8 - (st
->len
% 8);
725 st
->biglen
= st
->len
+ st
->pad
;
726 pktin
.length
= st
->len
- 5;
728 if (pktin
.maxlen
< st
->biglen
) {
729 pktin
.maxlen
= st
->biglen
;
730 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
731 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
733 fatalbox("Out of memory");
736 st
->to_read
= st
->biglen
;
738 while (st
->to_read
> 0) {
739 st
->chunk
= st
->to_read
;
740 while ((*datalen
) == 0)
741 crReturn(st
->to_read
);
742 if (st
->chunk
> (*datalen
))
743 st
->chunk
= (*datalen
);
744 memcpy(st
->p
, *data
, st
->chunk
);
746 *datalen
-= st
->chunk
;
748 st
->to_read
-= st
->chunk
;
751 if (cipher
&& detect_attack(pktin
.data
, st
->biglen
, NULL
)) {
752 bombout(("Network attack (CRC compensation) detected!"));
757 cipher
->decrypt(pktin
.data
, st
->biglen
);
759 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
760 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
761 if (st
->gotcrc
!= st
->realcrc
) {
762 bombout(("Incorrect CRC received on packet"));
766 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
768 if (ssh1_compressing
) {
769 unsigned char *decompblk
;
771 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
772 &decompblk
, &decomplen
);
774 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
775 pktin
.maxlen
= st
->pad
+ decomplen
;
776 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
777 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
779 fatalbox("Out of memory");
782 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
784 pktin
.length
= decomplen
- 1;
787 pktin
.type
= pktin
.body
[-1];
789 log_packet(PKT_INCOMING
, pktin
.type
, ssh1_pkt_type(pktin
.type
),
790 pktin
.body
, pktin
.length
);
792 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
793 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
794 pktin
.type
== SSH1_MSG_DEBUG
||
795 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
796 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
797 long stringlen
= GET_32BIT(pktin
.body
);
798 if (stringlen
+ 4 != pktin
.length
) {
799 bombout(("Received data packet with bogus string length"));
804 if (pktin
.type
== SSH1_MSG_DEBUG
) {
805 /* log debug message */
807 int stringlen
= GET_32BIT(pktin
.body
);
808 strcpy(buf
, "Remote: ");
811 memcpy(buf
+ 8, pktin
.body
+ 4, stringlen
);
812 buf
[8 + stringlen
] = '\0';
815 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
820 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
821 /* log reason code in disconnect message */
823 unsigned msglen
= GET_32BIT(pktin
.body
);
825 strcpy(buf
, "Remote sent disconnect: ");
826 nowlen
= strlen(buf
);
827 if (msglen
> sizeof(buf
) - nowlen
- 1)
828 msglen
= sizeof(buf
) - nowlen
- 1;
829 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
830 buf
[nowlen
+ msglen
] = '\0';
831 /* logevent(buf); (this is now done within the bombout macro) */
832 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
839 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
841 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
849 st
->cipherblk
= sccipher
->blksize
;
852 if (st
->cipherblk
< 8)
855 if (pktin
.maxlen
< st
->cipherblk
) {
856 pktin
.maxlen
= st
->cipherblk
;
859 NULL ?
smalloc(st
->cipherblk
+
860 APIEXTRA
) : srealloc(pktin
.data
,
864 fatalbox("Out of memory");
868 * Acquire and decrypt the first block of the packet. This will
869 * contain the length and padding details.
871 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
872 while ((*datalen
) == 0)
873 crReturn(st
->cipherblk
- st
->i
);
874 pktin
.data
[st
->i
] = *(*data
)++;
879 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
882 * Now get the length and padding figures.
884 st
->len
= GET_32BIT(pktin
.data
);
885 st
->pad
= pktin
.data
[4];
888 * This enables us to deduce the payload length.
890 st
->payload
= st
->len
- st
->pad
- 1;
892 pktin
.length
= st
->payload
+ 5;
895 * So now we can work out the total packet length.
897 st
->packetlen
= st
->len
+ 4;
898 st
->maclen
= scmac ? scmac
->len
: 0;
901 * Adjust memory allocation if packet is too big.
903 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
904 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
907 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
912 fatalbox("Out of memory");
916 * Read and decrypt the remainder of the packet.
918 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
920 while ((*datalen
) == 0)
921 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
922 pktin
.data
[st
->i
] = *(*data
)++;
925 /* Decrypt everything _except_ the MAC. */
927 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
928 st
->packetlen
- st
->cipherblk
);
934 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
935 st
->incoming_sequence
)) {
936 bombout(("Incorrect MAC received on packet"));
939 st
->incoming_sequence
++; /* whether or not we MACed */
942 * Decompress packet payload.
945 unsigned char *newpayload
;
947 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
948 &newpayload
, &newlen
)) {
949 if (pktin
.maxlen
< newlen
+ 5) {
950 pktin
.maxlen
= newlen
+ 5;
953 NULL ?
smalloc(pktin
.maxlen
+
954 APIEXTRA
) : srealloc(pktin
.data
,
958 fatalbox("Out of memory");
960 pktin
.length
= 5 + newlen
;
961 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
967 pktin
.type
= pktin
.data
[5];
969 log_packet(PKT_INCOMING
, pktin
.type
, ssh2_pkt_type(pktin
.type
),
970 pktin
.data
+6, pktin
.length
-6);
972 switch (pktin
.type
) {
974 * These packets we must handle instantly.
976 case SSH2_MSG_DISCONNECT
:
978 /* log reason code in disconnect message */
980 int reason
= GET_32BIT(pktin
.data
+ 6);
981 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
983 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
984 sprintf(buf
, "Received disconnect message (%s)",
985 ssh2_disconnect_reasons
[reason
]);
987 sprintf(buf
, "Received disconnect message (unknown type %d)",
991 strcpy(buf
, "Disconnection message text: ");
992 nowlen
= strlen(buf
);
993 if (msglen
> sizeof(buf
) - nowlen
- 1)
994 msglen
= sizeof(buf
) - nowlen
- 1;
995 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
996 buf
[nowlen
+ msglen
] = '\0';
998 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1000 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1001 ssh2_disconnect_reasons
[reason
] : "unknown",
1006 case SSH2_MSG_IGNORE
:
1008 case SSH2_MSG_DEBUG
:
1010 /* log the debug message */
1012 /* int display = pktin.body[6]; */
1013 int stringlen
= GET_32BIT(pktin
.data
+7);
1015 strcpy(buf
, "Remote debug message: ");
1016 prefix
= strlen(buf
);
1017 if (stringlen
> sizeof(buf
)-prefix
-1)
1018 stringlen
= sizeof(buf
)-prefix
-1;
1019 memcpy(buf
+ prefix
, pktin
.data
+ 11, stringlen
);
1020 buf
[prefix
+ stringlen
] = '\0';
1023 goto next_packet
; /* FIXME: print the debug message */
1026 * These packets we need do nothing about here.
1028 case SSH2_MSG_UNIMPLEMENTED
:
1029 case SSH2_MSG_SERVICE_REQUEST
:
1030 case SSH2_MSG_SERVICE_ACCEPT
:
1031 case SSH2_MSG_KEXINIT
:
1032 case SSH2_MSG_NEWKEYS
:
1033 case SSH2_MSG_KEXDH_INIT
:
1034 case SSH2_MSG_KEXDH_REPLY
:
1035 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1036 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1037 case SSH2_MSG_KEX_DH_GEX_INIT
:
1038 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1039 case SSH2_MSG_USERAUTH_REQUEST
:
1040 case SSH2_MSG_USERAUTH_FAILURE
:
1041 case SSH2_MSG_USERAUTH_SUCCESS
:
1042 case SSH2_MSG_USERAUTH_BANNER
:
1043 case SSH2_MSG_USERAUTH_PK_OK
:
1044 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1045 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1046 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1047 case SSH2_MSG_GLOBAL_REQUEST
:
1048 case SSH2_MSG_REQUEST_SUCCESS
:
1049 case SSH2_MSG_REQUEST_FAILURE
:
1050 case SSH2_MSG_CHANNEL_OPEN
:
1051 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1052 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1053 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1054 case SSH2_MSG_CHANNEL_DATA
:
1055 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1056 case SSH2_MSG_CHANNEL_EOF
:
1057 case SSH2_MSG_CHANNEL_CLOSE
:
1058 case SSH2_MSG_CHANNEL_REQUEST
:
1059 case SSH2_MSG_CHANNEL_SUCCESS
:
1060 case SSH2_MSG_CHANNEL_FAILURE
:
1064 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1067 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
1068 ssh2_pkt_adduint32(st
->incoming_sequence
- 1);
1076 static void ssh1_pktout_size(int len
)
1080 len
+= 5; /* type and CRC */
1081 pad
= 8 - (len
% 8);
1084 pktout
.length
= len
- 5;
1085 if (pktout
.maxlen
< biglen
) {
1086 pktout
.maxlen
= biglen
;
1088 /* Allocate enough buffer space for extra block
1089 * for MS CryptEncrypt() */
1090 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
1091 srealloc(pktout
.data
, biglen
+ 12));
1093 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
1094 srealloc(pktout
.data
, biglen
+ 4));
1097 fatalbox("Out of memory");
1099 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
1102 static void s_wrpkt_start(int type
, int len
)
1104 ssh1_pktout_size(len
);
1108 static int s_wrpkt_prepare(void)
1110 int pad
, len
, biglen
, i
;
1113 pktout
.body
[-1] = pktout
.type
;
1115 log_packet(PKT_OUTGOING
, pktout
.type
, ssh1_pkt_type(pktout
.type
),
1116 pktout
.body
, pktout
.length
);
1118 if (ssh1_compressing
) {
1119 unsigned char *compblk
;
1121 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
1122 &compblk
, &complen
);
1123 ssh1_pktout_size(complen
- 1);
1124 memcpy(pktout
.body
- 1, compblk
, complen
);
1128 len
= pktout
.length
+ 5; /* type and CRC */
1129 pad
= 8 - (len
% 8);
1132 for (i
= 0; i
< pad
; i
++)
1133 pktout
.data
[i
+ 4] = random_byte();
1134 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
1135 PUT_32BIT(pktout
.data
+ biglen
, crc
);
1136 PUT_32BIT(pktout
.data
, len
);
1139 cipher
->encrypt(pktout
.data
+ 4, biglen
);
1144 static void s_wrpkt(void)
1147 len
= s_wrpkt_prepare();
1148 backlog
= sk_write(s
, pktout
.data
, len
);
1149 if (backlog
> SSH_MAX_BACKLOG
)
1150 ssh_throttle_all(1, backlog
);
1153 static void s_wrpkt_defer(void)
1156 len
= s_wrpkt_prepare();
1157 if (deferred_len
+ len
> deferred_size
) {
1158 deferred_size
= deferred_len
+ len
+ 128;
1159 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1161 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1162 deferred_len
+= len
;
1166 * Construct a packet with the specified contents.
1168 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1170 unsigned char *p
, *argp
, argchar
;
1171 unsigned long argint
;
1172 int pktlen
, argtype
, arglen
;
1176 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1179 (void) va_arg(ap1
, int);
1183 (void) va_arg(ap1
, char);
1187 (void) va_arg(ap1
, unsigned char *);
1188 arglen
= va_arg(ap1
, int);
1192 argp
= va_arg(ap1
, unsigned char *);
1193 arglen
= strlen(argp
);
1194 pktlen
+= 4 + arglen
;
1197 bn
= va_arg(ap1
, Bignum
);
1198 pktlen
+= ssh1_bignum_length(bn
);
1205 s_wrpkt_start(pkttype
, pktlen
);
1208 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1211 argint
= va_arg(ap2
, int);
1212 PUT_32BIT(p
, argint
);
1216 argchar
= va_arg(ap2
, unsigned char);
1221 argp
= va_arg(ap2
, unsigned char *);
1222 arglen
= va_arg(ap2
, int);
1223 memcpy(p
, argp
, arglen
);
1227 argp
= va_arg(ap2
, unsigned char *);
1228 arglen
= strlen(argp
);
1229 PUT_32BIT(p
, arglen
);
1230 memcpy(p
+ 4, argp
, arglen
);
1234 bn
= va_arg(ap2
, Bignum
);
1235 p
+= ssh1_write_bignum(p
, bn
);
1241 static void send_packet(int pkttype
, ...)
1244 va_start(ap1
, pkttype
);
1245 va_start(ap2
, pkttype
);
1246 construct_packet(pkttype
, ap1
, ap2
);
1250 static void defer_packet(int pkttype
, ...)
1253 va_start(ap1
, pkttype
);
1254 va_start(ap2
, pkttype
);
1255 construct_packet(pkttype
, ap1
, ap2
);
1259 static int ssh_versioncmp(char *a
, char *b
)
1262 unsigned long av
, bv
;
1264 av
= strtoul(a
, &ae
, 10);
1265 bv
= strtoul(b
, &be
, 10);
1267 return (av
< bv ?
-1 : +1);
1272 av
= strtoul(ae
, &ae
, 10);
1273 bv
= strtoul(be
, &be
, 10);
1275 return (av
< bv ?
-1 : +1);
1281 * Utility routines for putting an SSH-protocol `string' and
1282 * `uint32' into a SHA state.
1285 static void sha_string(SHA_State
* s
, void *str
, int len
)
1287 unsigned char lenblk
[4];
1288 PUT_32BIT(lenblk
, len
);
1289 SHA_Bytes(s
, lenblk
, 4);
1290 SHA_Bytes(s
, str
, len
);
1293 static void sha_uint32(SHA_State
* s
, unsigned i
)
1295 unsigned char intblk
[4];
1296 PUT_32BIT(intblk
, i
);
1297 SHA_Bytes(s
, intblk
, 4);
1301 * SSH2 packet construction functions.
1303 static void ssh2_pkt_ensure(int length
)
1305 if (pktout
.maxlen
< length
) {
1306 pktout
.maxlen
= length
+ 256;
1309 NULL ?
smalloc(pktout
.maxlen
+
1310 APIEXTRA
) : srealloc(pktout
.data
,
1314 fatalbox("Out of memory");
1317 static void ssh2_pkt_adddata(void *data
, int len
)
1319 pktout
.length
+= len
;
1320 ssh2_pkt_ensure(pktout
.length
);
1321 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1323 static void ssh2_pkt_addbyte(unsigned char byte
)
1325 ssh2_pkt_adddata(&byte
, 1);
1327 static void ssh2_pkt_init(int pkt_type
)
1330 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1332 static void ssh2_pkt_addbool(unsigned char value
)
1334 ssh2_pkt_adddata(&value
, 1);
1336 static void ssh2_pkt_adduint32(unsigned long value
)
1339 PUT_32BIT(x
, value
);
1340 ssh2_pkt_adddata(x
, 4);
1342 static void ssh2_pkt_addstring_start(void)
1344 ssh2_pkt_adduint32(0);
1345 pktout
.savedpos
= pktout
.length
;
1347 static void ssh2_pkt_addstring_str(char *data
)
1349 ssh2_pkt_adddata(data
, strlen(data
));
1350 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1351 pktout
.length
- pktout
.savedpos
);
1353 static void ssh2_pkt_addstring_data(char *data
, int len
)
1355 ssh2_pkt_adddata(data
, len
);
1356 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1357 pktout
.length
- pktout
.savedpos
);
1359 static void ssh2_pkt_addstring(char *data
)
1361 ssh2_pkt_addstring_start();
1362 ssh2_pkt_addstring_str(data
);
1364 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1367 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1370 fatalbox("out of memory");
1372 for (i
= 1; i
<= n
; i
++)
1373 p
[i
] = bignum_byte(b
, n
- i
);
1375 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1377 memmove(p
, p
+ i
, n
+ 1 - i
);
1381 static void ssh2_pkt_addmp(Bignum b
)
1385 p
= ssh2_mpint_fmt(b
, &len
);
1386 ssh2_pkt_addstring_start();
1387 ssh2_pkt_addstring_data(p
, len
);
1392 * Construct an SSH2 final-form packet: compress it, encrypt it,
1393 * put the MAC on it. Final packet, ready to be sent, is stored in
1394 * pktout.data. Total length is returned.
1396 static int ssh2_pkt_construct(void)
1398 int cipherblk
, maclen
, padding
, i
;
1399 static unsigned long outgoing_sequence
= 0;
1401 log_packet(PKT_OUTGOING
, pktout
.data
[5], ssh2_pkt_type(pktout
.data
[5]),
1402 pktout
.data
+ 6, pktout
.length
- 6);
1405 * Compress packet payload.
1408 unsigned char *newpayload
;
1410 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1411 &newpayload
, &newlen
)) {
1413 ssh2_pkt_adddata(newpayload
, newlen
);
1419 * Add padding. At least four bytes, and must also bring total
1420 * length (minus MAC) up to a multiple of the block size.
1422 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1423 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1426 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1427 maclen
= csmac ? csmac
->len
: 0;
1428 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1429 pktout
.data
[4] = padding
;
1430 for (i
= 0; i
< padding
; i
++)
1431 pktout
.data
[pktout
.length
+ i
] = random_byte();
1432 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1434 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1436 outgoing_sequence
++; /* whether or not we MACed */
1439 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1441 /* Ready-to-send packet starts at pktout.data. We return length. */
1442 return pktout
.length
+ padding
+ maclen
;
1446 * Construct and send an SSH2 packet immediately.
1448 static void ssh2_pkt_send(void)
1452 len
= ssh2_pkt_construct();
1453 backlog
= sk_write(s
, pktout
.data
, len
);
1454 if (backlog
> SSH_MAX_BACKLOG
)
1455 ssh_throttle_all(1, backlog
);
1459 * Construct an SSH2 packet and add it to a deferred data block.
1460 * Useful for sending multiple packets in a single sk_write() call,
1461 * to prevent a traffic-analysing listener from being able to work
1462 * out the length of any particular packet (such as the password
1465 * Note that because SSH2 sequence-numbers its packets, this can
1466 * NOT be used as an m4-style `defer' allowing packets to be
1467 * constructed in one order and sent in another.
1469 static void ssh2_pkt_defer(void)
1471 int len
= ssh2_pkt_construct();
1472 if (deferred_len
+ len
> deferred_size
) {
1473 deferred_size
= deferred_len
+ len
+ 128;
1474 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1476 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1477 deferred_len
+= len
;
1481 * Send the whole deferred data block constructed by
1482 * ssh2_pkt_defer() or SSH1's defer_packet().
1484 static void ssh_pkt_defersend(void)
1487 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1488 deferred_len
= deferred_size
= 0;
1489 sfree(deferred_send_data
);
1490 deferred_send_data
= NULL
;
1491 if (backlog
> SSH_MAX_BACKLOG
)
1492 ssh_throttle_all(1, backlog
);
1496 void bndebug(char *string
, Bignum b
)
1500 p
= ssh2_mpint_fmt(b
, &len
);
1501 debug(("%s", string
));
1502 for (i
= 0; i
< len
; i
++)
1503 debug((" %02x", p
[i
]));
1509 static void sha_mpint(SHA_State
* s
, Bignum b
)
1513 p
= ssh2_mpint_fmt(b
, &len
);
1514 sha_string(s
, p
, len
);
1519 * SSH2 packet decode functions.
1521 static unsigned long ssh2_pkt_getuint32(void)
1523 unsigned long value
;
1524 if (pktin
.length
- pktin
.savedpos
< 4)
1525 return 0; /* arrgh, no way to decline (FIXME?) */
1526 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1527 pktin
.savedpos
+= 4;
1530 static int ssh2_pkt_getbool(void)
1532 unsigned long value
;
1533 if (pktin
.length
- pktin
.savedpos
< 1)
1534 return 0; /* arrgh, no way to decline (FIXME?) */
1535 value
= pktin
.data
[pktin
.savedpos
] != 0;
1539 static void ssh2_pkt_getstring(char **p
, int *length
)
1543 if (pktin
.length
- pktin
.savedpos
< 4)
1545 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1546 pktin
.savedpos
+= 4;
1547 if (pktin
.length
- pktin
.savedpos
< *length
)
1549 *p
= pktin
.data
+ pktin
.savedpos
;
1550 pktin
.savedpos
+= *length
;
1552 static Bignum
ssh2_pkt_getmp(void)
1558 ssh2_pkt_getstring(&p
, &length
);
1562 bombout(("internal error: Can't handle negative mpints"));
1565 b
= bignum_from_bytes(p
, length
);
1570 * Helper function to add an SSH2 signature blob to a packet.
1571 * Expects to be shown the public key blob as well as the signature
1572 * blob. Normally works just like ssh2_pkt_addstring, but will
1573 * fiddle with the signature packet if necessary for
1574 * BUG_SSH2_RSA_PADDING.
1576 static void ssh2_add_sigblob(void *pkblob_v
, int pkblob_len
,
1577 void *sigblob_v
, int sigblob_len
)
1579 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1580 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1582 /* dmemdump(pkblob, pkblob_len); */
1583 /* dmemdump(sigblob, sigblob_len); */
1586 * See if this is in fact an ssh-rsa signature and a buggy
1587 * server; otherwise we can just do this the easy way.
1589 if ((ssh_remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1590 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1591 int pos
, len
, siglen
;
1594 * Find the byte length of the modulus.
1597 pos
= 4+7; /* skip over "ssh-rsa" */
1598 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1599 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1600 pos
+= 4; /* find modulus itself */
1601 while (len
> 0 && pkblob
[pos
] == 0)
1603 /* debug(("modulus length is %d\n", len)); */
1606 * Now find the signature integer.
1608 pos
= 4+7; /* skip over "ssh-rsa" */
1609 siglen
= GET_32BIT(sigblob
+pos
);
1610 /* debug(("signature length is %d\n", siglen)); */
1612 if (len
!= siglen
) {
1613 unsigned char newlen
[4];
1614 ssh2_pkt_addstring_start();
1615 ssh2_pkt_addstring_data(sigblob
, pos
);
1616 /* dmemdump(sigblob, pos); */
1617 pos
+= 4; /* point to start of actual sig */
1618 PUT_32BIT(newlen
, len
);
1619 ssh2_pkt_addstring_data(newlen
, 4);
1620 /* dmemdump(newlen, 4); */
1622 while (len
-- > siglen
) {
1623 ssh2_pkt_addstring_data(newlen
, 1);
1624 /* dmemdump(newlen, 1); */
1626 ssh2_pkt_addstring_data(sigblob
+pos
, siglen
);
1627 /* dmemdump(sigblob+pos, siglen); */
1631 /* Otherwise fall through and do it the easy way. */
1634 ssh2_pkt_addstring_start();
1635 ssh2_pkt_addstring_data(sigblob
, sigblob_len
);
1639 * Examine the remote side's version string and compare it against
1640 * a list of known buggy implementations.
1642 static void ssh_detect_bugs(char *vstring
)
1644 char *imp
; /* pointer to implementation part */
1646 imp
+= strcspn(imp
, "-");
1648 imp
+= strcspn(imp
, "-");
1651 ssh_remote_bugs
= 0;
1653 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1654 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1655 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1657 * These versions don't support SSH1_MSG_IGNORE, so we have
1658 * to use a different defence against password length
1661 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1662 logevent("We believe remote version has SSH1 ignore bug");
1665 if (!strcmp(imp
, "Cisco-1.25")) {
1667 * These versions need a plain password sent; they can't
1668 * handle having a null and a random length of data after
1671 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1672 logevent("We believe remote version needs a plain SSH1 password");
1675 if (!strcmp(imp
, "Cisco-1.25")) {
1677 * These versions apparently have no clue whatever about
1678 * RSA authentication and will panic and die if they see
1679 * an AUTH_RSA message.
1681 ssh_remote_bugs
|= BUG_CHOKES_ON_RSA
;
1682 logevent("We believe remote version can't handle RSA authentication");
1685 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1686 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1687 !strncmp(imp
, "2.1 ", 4)) {
1689 * These versions have the HMAC bug.
1691 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1692 logevent("We believe remote version has SSH2 HMAC bug");
1695 if ((!strncmp(imp
, "OpenSSH_2.", 10) && imp
[10]>='5' && imp
[10]<='9') ||
1696 (!strncmp(imp
, "OpenSSH_3.", 10) && imp
[10]>='0' && imp
[10]<='2')) {
1698 * These versions have the SSH2 RSA padding bug.
1700 ssh_remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1701 logevent("We believe remote version has SSH2 RSA padding bug");
1705 static int do_ssh_init(unsigned char c
)
1708 static char version
[10];
1709 static char *vstring
;
1710 static int vstrsize
;
1716 /* Search for the string "SSH-" in the input. */
1719 static const int transS
[] = { 1, 2, 2, 1 };
1720 static const int transH
[] = { 0, 0, 3, 0 };
1721 static const int transminus
[] = { 0, 0, 0, -1 };
1732 crReturn(1); /* get another character */
1736 vstring
= smalloc(vstrsize
);
1737 strcpy(vstring
, "SSH-");
1741 crReturn(1); /* get another char */
1742 if (vslen
>= vstrsize
- 1) {
1744 vstring
= srealloc(vstring
, vstrsize
);
1746 vstring
[vslen
++] = c
;
1751 } else if (i
< sizeof(version
) - 1)
1753 } else if (c
== '\n')
1757 ssh_agentfwd_enabled
= FALSE
;
1758 rdpkt2_state
.incoming_sequence
= 0;
1761 vlog
= smalloc(20 + vslen
);
1762 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1763 sprintf(vlog
, "Server version: %s", vstring
);
1765 ssh_detect_bugs(vstring
);
1769 * Server version "1.99" means we can choose whether we use v1
1770 * or v2 protocol. Choice is based on cfg.sshprot.
1772 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1774 * This is a v2 server. Begin v2 protocol.
1776 char verstring
[80], vlog
[100];
1777 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1778 SHA_Init(&exhashbase
);
1780 * Hash our version string and their version string.
1782 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1783 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1784 sprintf(vlog
, "We claim version: %s", verstring
);
1786 strcat(verstring
, "\n");
1787 logevent("Using SSH protocol version 2");
1788 sk_write(s
, verstring
, strlen(verstring
));
1789 ssh_protocol
= ssh2_protocol
;
1791 s_rdpkt
= ssh2_rdpkt
;
1794 * This is a v1 server. Begin v1 protocol.
1796 char verstring
[80], vlog
[100];
1797 sprintf(verstring
, "SSH-%s-%s",
1798 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1800 sprintf(vlog
, "We claim version: %s", verstring
);
1802 strcat(verstring
, "\n");
1804 if (cfg
.sshprot
== 3) {
1805 bombout(("SSH protocol version 2 required by user but not provided by server"));
1809 logevent("Using SSH protocol version 1");
1810 sk_write(s
, verstring
, strlen(verstring
));
1811 ssh_protocol
= ssh1_protocol
;
1813 s_rdpkt
= ssh1_rdpkt
;
1815 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1822 static void ssh_gotdata(unsigned char *data
, int datalen
)
1827 * To begin with, feed the characters one by one to the
1828 * protocol initialisation / selection function do_ssh_init().
1829 * When that returns 0, we're done with the initial greeting
1830 * exchange and can move on to packet discipline.
1835 crReturnV
; /* more data please */
1836 ret
= do_ssh_init(*data
);
1844 * We emerge from that loop when the initial negotiation is
1845 * over and we have selected an s_rdpkt function. Now pass
1846 * everything to s_rdpkt, and then pass the resulting packets
1847 * to the proper protocol handler.
1852 while (datalen
> 0) {
1853 if (s_rdpkt(&data
, &datalen
) == 0) {
1854 if (ssh_state
== SSH_STATE_CLOSED
) {
1857 ssh_protocol(NULL
, 0, 1);
1858 if (ssh_state
== SSH_STATE_CLOSED
) {
1868 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1871 ssh_state
= SSH_STATE_CLOSED
;
1877 /* A socket error has occurred. */
1878 logevent(error_msg
);
1879 connection_fatal(error_msg
);
1881 /* Otherwise, the remote side closed the connection normally. */
1886 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1888 ssh_gotdata(data
, len
);
1889 if (ssh_state
== SSH_STATE_CLOSED
) {
1899 static void ssh_sent(Plug plug
, int bufsize
)
1902 * If the send backlog on the SSH socket itself clears, we
1903 * should unthrottle the whole world if it was throttled.
1905 if (bufsize
< SSH_MAX_BACKLOG
)
1906 ssh_throttle_all(0, bufsize
);
1910 * Connect to specified host and port.
1911 * Returns an error message, or NULL on success.
1912 * Also places the canonical host name into `realhost'. It must be
1913 * freed by the caller.
1915 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1917 static struct plug_function_table fn_table
= {
1922 }, *fn_table_ptr
= &fn_table
;
1931 savedhost
= smalloc(1 + strlen(host
));
1933 fatalbox("Out of memory");
1934 strcpy(savedhost
, host
);
1937 port
= 22; /* default ssh port */
1952 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1955 addr
= sk_namelookup(host
, realhost
);
1956 if ((err
= sk_addr_error(addr
)))
1960 *realhost
= strdup(FWhost
);
1967 char buf
[200], addrbuf
[100];
1968 sk_getaddr(addr
, addrbuf
, 100);
1969 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1972 s
= new_connection(addr
, *realhost
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1973 if ((err
= sk_socket_error(s
))) {
1979 sk_write(s
, "connect ", 8);
1980 sk_write(s
, FWhost
, strlen(FWhost
));
1983 sprintf(buf
, " %d\n", FWport
);
1984 sk_write(s
, buf
, strlen(buf
));
1992 * Throttle or unthrottle the SSH connection.
1994 static void ssh1_throttle(int adjust
)
1996 int old_count
= ssh1_throttle_count
;
1997 ssh1_throttle_count
+= adjust
;
1998 assert(ssh1_throttle_count
>= 0);
1999 if (ssh1_throttle_count
&& !old_count
) {
2000 sk_set_frozen(s
, 1);
2001 } else if (!ssh1_throttle_count
&& old_count
) {
2002 sk_set_frozen(s
, 0);
2007 * Throttle or unthrottle _all_ local data streams (for when sends
2008 * on the SSH connection itself back up).
2010 static void ssh_throttle_all(int enable
, int bufsize
)
2013 struct ssh_channel
*c
;
2015 if (enable
== ssh_throttled_all
)
2017 ssh_throttled_all
= enable
;
2018 ssh_overall_bufsize
= bufsize
;
2021 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
2023 case CHAN_MAINSESSION
:
2025 * This is treated separately, outside the switch.
2029 x11_override_throttle(c
->u
.x11
.s
, enable
);
2032 /* Agent channels require no buffer management. */
2035 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2042 * Handle the key exchange and user authentication phases.
2044 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
2048 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
2049 unsigned char cookie
[8];
2050 struct RSAKey servkey
, hostkey
;
2051 struct MD5Context md5c
;
2052 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
2053 static int tried_publickey
, tried_agent
;
2054 static int tis_auth_refused
, ccard_auth_refused
;
2055 static unsigned char session_id
[16];
2056 static int cipher_type
;
2057 static char username
[100];
2058 static void *publickey_blob
;
2059 int publickey_bloblen
;
2066 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2067 bombout(("Public key packet not received"));
2071 logevent("Received public keys");
2073 memcpy(cookie
, pktin
.body
, 8);
2075 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
2076 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
2079 * Log the host key fingerprint.
2083 logevent("Host key fingerprint is:");
2084 strcpy(logmsg
, " ");
2085 hostkey
.comment
= NULL
;
2086 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2087 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2091 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
2092 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
2093 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
2095 ssh1_local_protoflags
=
2096 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2097 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2100 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
2101 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
2102 MD5Update(&md5c
, pktin
.body
, 8);
2103 MD5Final(session_id
, &md5c
);
2105 for (i
= 0; i
< 32; i
++)
2106 session_key
[i
] = random_byte();
2108 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2110 rsabuf
= smalloc(len
);
2112 fatalbox("Out of memory");
2115 * Verify the host key.
2119 * First format the key into a string.
2121 int len
= rsastr_len(&hostkey
);
2122 char fingerprint
[100];
2123 char *keystr
= smalloc(len
);
2125 fatalbox("Out of memory");
2126 rsastr_fmt(keystr
, &hostkey
);
2127 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2128 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
2133 for (i
= 0; i
< 32; i
++) {
2134 rsabuf
[i
] = session_key
[i
];
2136 rsabuf
[i
] ^= session_id
[i
];
2139 if (hostkey
.bytes
> servkey
.bytes
) {
2140 rsaencrypt(rsabuf
, 32, &servkey
);
2141 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
2143 rsaencrypt(rsabuf
, 32, &hostkey
);
2144 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
2147 logevent("Encrypted session key");
2150 int cipher_chosen
= 0, warn
= 0;
2151 char *cipher_string
= NULL
;
2152 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2153 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2154 if (next_cipher
== CIPHER_WARN
) {
2155 /* If/when we choose a cipher, warn about it */
2157 } else if (next_cipher
== CIPHER_AES
) {
2158 /* XXX Probably don't need to mention this. */
2159 logevent("AES not supported in SSH1, skipping");
2161 switch (next_cipher
) {
2162 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
2163 cipher_string
= "3DES"; break;
2164 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
2165 cipher_string
= "Blowfish"; break;
2166 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
2167 cipher_string
= "single-DES"; break;
2169 if (supported_ciphers_mask
& (1 << cipher_type
))
2173 if (!cipher_chosen
) {
2174 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2175 bombout(("Server violates SSH 1 protocol by not "
2176 "supporting 3DES encryption"));
2178 /* shouldn't happen */
2179 bombout(("No supported ciphers found"));
2183 /* Warn about chosen cipher if necessary. */
2185 askcipher(cipher_string
, 0);
2188 switch (cipher_type
) {
2189 case SSH_CIPHER_3DES
:
2190 logevent("Using 3DES encryption");
2192 case SSH_CIPHER_DES
:
2193 logevent("Using single-DES encryption");
2195 case SSH_CIPHER_BLOWFISH
:
2196 logevent("Using Blowfish encryption");
2200 send_packet(SSH1_CMSG_SESSION_KEY
,
2201 PKT_CHAR
, cipher_type
,
2202 PKT_DATA
, cookie
, 8,
2203 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
2204 PKT_DATA
, rsabuf
, len
,
2205 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
2207 logevent("Trying to enable encryption...");
2211 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2212 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
2213 cipher
->sesskey(session_key
);
2217 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2218 bombout(("Encryption not successfully enabled"));
2222 logevent("Successfully started encryption");
2228 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2229 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2230 if (!ssh_get_line("login as: ",
2231 username
, sizeof(username
), FALSE
)) {
2233 * get_line failed to get a username.
2236 logevent("No username provided. Abandoning session.");
2237 ssh_state
= SSH_STATE_CLOSED
;
2241 c_write_str("login as: ");
2244 crWaitUntil(!ispkt
);
2246 switch (c
= *in
++) {
2255 c_write_str("\b \b");
2262 c_write_str("\b \b");
2271 if (((c
>= ' ' && c
<= '~') ||
2272 ((unsigned char) c
>= 160))
2273 && pos
< sizeof(username
)-1) {
2274 username
[pos
++] = c
;
2280 c_write_str("\r\n");
2281 username
[strcspn(username
, "\n\r")] = '\0';
2284 strncpy(username
, cfg
.username
, 99);
2285 username
[99] = '\0';
2288 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2290 char userlog
[22 + sizeof(username
)];
2291 sprintf(userlog
, "Sent username \"%s\"", username
);
2293 if (flags
& FLAG_INTERACTIVE
&&
2294 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2295 strcat(userlog
, "\r\n");
2296 c_write_str(userlog
);
2303 if ((ssh_remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2304 /* We must not attempt PK auth. Pretend we've already tried it. */
2305 tried_publickey
= tried_agent
= 1;
2307 tried_publickey
= tried_agent
= 0;
2309 tis_auth_refused
= ccard_auth_refused
= 0;
2310 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2312 if (!rsakey_pubblob(cfg
.keyfile
, &publickey_blob
, &publickey_bloblen
))
2313 publickey_blob
= NULL
;
2315 publickey_blob
= NULL
;
2317 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2318 static char password
[100];
2319 static char prompt
[200];
2322 static int pwpkt_type
;
2323 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2325 if (agent_exists() && !tried_agent
) {
2327 * Attempt RSA authentication using Pageant.
2329 static unsigned char request
[5], *response
, *p
;
2330 static int responselen
;
2331 static int i
, nkeys
;
2332 static int authed
= FALSE
;
2336 logevent("Pageant is running. Requesting keys.");
2338 /* Request the keys held by the agent. */
2339 PUT_32BIT(request
, 1);
2340 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2341 agent_query(request
, 5, &r
, &responselen
);
2342 response
= (unsigned char *) r
;
2343 if (response
&& responselen
>= 5 &&
2344 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2346 nkeys
= GET_32BIT(p
);
2350 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2353 for (i
= 0; i
< nkeys
; i
++) {
2354 static struct RSAKey key
;
2355 static Bignum challenge
;
2356 static char *commentp
;
2357 static int commentlen
;
2361 sprintf(buf
, "Trying Pageant key #%d", i
);
2364 if (publickey_blob
&&
2365 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
2366 logevent("This key matches configured key file");
2367 tried_publickey
= 1;
2370 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2371 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2372 commentlen
= GET_32BIT(p
);
2376 send_packet(SSH1_CMSG_AUTH_RSA
,
2377 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2379 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2380 logevent("Key refused");
2383 logevent("Received RSA challenge");
2384 ssh1_read_bignum(pktin
.body
, &challenge
);
2386 char *agentreq
, *q
, *ret
;
2389 len
= 1 + 4; /* message type, bit count */
2390 len
+= ssh1_bignum_length(key
.exponent
);
2391 len
+= ssh1_bignum_length(key
.modulus
);
2392 len
+= ssh1_bignum_length(challenge
);
2393 len
+= 16; /* session id */
2394 len
+= 4; /* response format */
2395 agentreq
= smalloc(4 + len
);
2396 PUT_32BIT(agentreq
, len
);
2398 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2399 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2401 q
+= ssh1_write_bignum(q
, key
.exponent
);
2402 q
+= ssh1_write_bignum(q
, key
.modulus
);
2403 q
+= ssh1_write_bignum(q
, challenge
);
2404 memcpy(q
, session_id
, 16);
2406 PUT_32BIT(q
, 1); /* response format */
2407 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2411 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2412 logevent("Sending Pageant's response");
2413 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2414 PKT_DATA
, ret
+ 5, 16,
2418 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2420 ("Pageant's response accepted");
2421 if (flags
& FLAG_VERBOSE
) {
2423 ("Authenticated using RSA key \"");
2424 c_write(commentp
, commentlen
);
2425 c_write_str("\" from agent\r\n");
2430 ("Pageant's response not accepted");
2433 ("Pageant failed to answer challenge");
2437 logevent("No reply received from Pageant");
2440 freebn(key
.exponent
);
2441 freebn(key
.modulus
);
2450 if (*cfg
.keyfile
&& !tried_publickey
)
2451 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2453 if (cfg
.try_tis_auth
&&
2454 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2455 !tis_auth_refused
) {
2456 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2457 logevent("Requested TIS authentication");
2458 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2460 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2461 logevent("TIS authentication declined");
2462 if (flags
& FLAG_INTERACTIVE
)
2463 c_write_str("TIS authentication refused.\r\n");
2464 tis_auth_refused
= 1;
2467 int challengelen
= ((pktin
.body
[0] << 24) |
2468 (pktin
.body
[1] << 16) |
2469 (pktin
.body
[2] << 8) |
2471 logevent("Received TIS challenge");
2472 if (challengelen
> sizeof(prompt
) - 1)
2473 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2474 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2475 /* Prompt heuristic comes from OpenSSH */
2476 strncpy(prompt
+ challengelen
,
2477 memchr(prompt
, '\n', challengelen
) ?
2478 "": "\r\nResponse: ",
2479 (sizeof prompt
) - challengelen
);
2480 prompt
[(sizeof prompt
) - 1] = '\0';
2483 if (cfg
.try_tis_auth
&&
2484 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2485 !ccard_auth_refused
) {
2486 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2487 logevent("Requested CryptoCard authentication");
2488 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2490 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2491 logevent("CryptoCard authentication declined");
2492 c_write_str("CryptoCard authentication refused.\r\n");
2493 ccard_auth_refused
= 1;
2496 int challengelen
= ((pktin
.body
[0] << 24) |
2497 (pktin
.body
[1] << 16) |
2498 (pktin
.body
[2] << 8) |
2500 logevent("Received CryptoCard challenge");
2501 if (challengelen
> sizeof(prompt
) - 1)
2502 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2503 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2504 strncpy(prompt
+ challengelen
,
2505 memchr(prompt
, '\n', challengelen
) ?
2506 "" : "\r\nResponse: ",
2507 sizeof(prompt
) - challengelen
);
2508 prompt
[sizeof(prompt
) - 1] = '\0';
2511 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2512 sprintf(prompt
, "%.90s@%.90s's password: ",
2513 username
, savedhost
);
2515 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2516 char *comment
= NULL
;
2519 if (flags
& FLAG_VERBOSE
)
2520 c_write_str("Trying public key authentication.\r\n");
2521 sprintf(msgbuf
, "Trying public key \"%.200s\"", cfg
.keyfile
);
2523 type
= key_type(cfg
.keyfile
);
2524 if (type
!= SSH_KEYTYPE_SSH1
) {
2525 sprintf(msgbuf
, "Key is of wrong type (%s)",
2526 key_type_to_str(type
));
2528 c_write_str(msgbuf
);
2529 c_write_str("\r\n");
2530 tried_publickey
= 1;
2533 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2534 if (flags
& FLAG_VERBOSE
)
2535 c_write_str("No passphrase required.\r\n");
2538 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2543 * Show password prompt, having first obtained it via a TIS
2544 * or CryptoCard exchange if we're doing TIS or CryptoCard
2548 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2550 * get_line failed to get a password (for example
2551 * because one was supplied on the command line
2552 * which has already failed to work). Terminate.
2554 send_packet(SSH1_MSG_DISCONNECT
,
2555 PKT_STR
, "No more passwords available to try",
2557 logevent("Unable to authenticate");
2558 connection_fatal("Unable to authenticate");
2559 ssh_state
= SSH_STATE_CLOSED
;
2563 /* Prompt may have come from server. We've munged it a bit, so
2564 * we know it to be zero-terminated at least once. */
2565 c_write_untrusted(prompt
, strlen(prompt
));
2569 crWaitUntil(!ispkt
);
2571 switch (c
= *in
++) {
2591 if (pos
< sizeof(password
)-1)
2592 password
[pos
++] = c
;
2596 c_write_str("\r\n");
2600 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2602 * Try public key authentication with the specified
2605 static struct RSAKey pubkey
;
2606 static Bignum challenge
, response
;
2608 static unsigned char buffer
[32];
2610 tried_publickey
= 1;
2611 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2613 c_write_str("Couldn't load private key from ");
2614 c_write_str(cfg
.keyfile
);
2615 c_write_str(".\r\n");
2616 continue; /* go and try password */
2619 c_write_str("Wrong passphrase.\r\n");
2620 tried_publickey
= 0;
2621 continue; /* try again */
2625 * Send a public key attempt.
2627 send_packet(SSH1_CMSG_AUTH_RSA
,
2628 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2631 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2632 c_write_str("Server refused our public key.\r\n");
2633 continue; /* go and try password */
2635 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2636 bombout(("Bizarre response to offer of public key"));
2639 ssh1_read_bignum(pktin
.body
, &challenge
);
2640 response
= rsadecrypt(challenge
, &pubkey
);
2641 freebn(pubkey
.private_exponent
); /* burn the evidence */
2643 for (i
= 0; i
< 32; i
++) {
2644 buffer
[i
] = bignum_byte(response
, 31 - i
);
2648 MD5Update(&md5c
, buffer
, 32);
2649 MD5Update(&md5c
, session_id
, 16);
2650 MD5Final(buffer
, &md5c
);
2652 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2653 PKT_DATA
, buffer
, 16, PKT_END
);
2656 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2657 if (flags
& FLAG_VERBOSE
)
2659 ("Failed to authenticate with our public key.\r\n");
2660 continue; /* go and try password */
2661 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2663 ("Bizarre response to RSA authentication response"));
2667 break; /* we're through! */
2669 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2671 * Defence against traffic analysis: we send a
2672 * whole bunch of packets containing strings of
2673 * different lengths. One of these strings is the
2674 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2675 * The others are all random data in
2676 * SSH1_MSG_IGNORE packets. This way a passive
2677 * listener can't tell which is the password, and
2678 * hence can't deduce the password length.
2680 * Anybody with a password length greater than 16
2681 * bytes is going to have enough entropy in their
2682 * password that a listener won't find it _that_
2683 * much help to know how long it is. So what we'll
2686 * - if password length < 16, we send 15 packets
2687 * containing string lengths 1 through 15
2689 * - otherwise, we let N be the nearest multiple
2690 * of 8 below the password length, and send 8
2691 * packets containing string lengths N through
2692 * N+7. This won't obscure the order of
2693 * magnitude of the password length, but it will
2694 * introduce a bit of extra uncertainty.
2696 * A few servers (the old 1.2.18 through 1.2.22)
2697 * can't deal with SSH1_MSG_IGNORE. For these
2698 * servers, we need an alternative defence. We make
2699 * use of the fact that the password is interpreted
2700 * as a C string: so we can append a NUL, then some
2703 * One server (a Cisco one) can deal with neither
2704 * SSH1_MSG_IGNORE _nor_ a padded password string.
2705 * For this server we are left with no defences
2706 * against password length sniffing.
2708 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2710 * The server can deal with SSH1_MSG_IGNORE, so
2711 * we can use the primary defence.
2713 int bottom
, top
, pwlen
, i
;
2716 pwlen
= strlen(password
);
2718 bottom
= 0; /* zero length passwords are OK! :-) */
2721 bottom
= pwlen
& ~7;
2725 assert(pwlen
>= bottom
&& pwlen
<= top
);
2727 randomstr
= smalloc(top
+ 1);
2729 for (i
= bottom
; i
<= top
; i
++) {
2731 defer_packet(pwpkt_type
, PKT_STR
, password
,
2734 for (j
= 0; j
< i
; j
++) {
2736 randomstr
[j
] = random_byte();
2737 } while (randomstr
[j
] == '\0');
2739 randomstr
[i
] = '\0';
2740 defer_packet(SSH1_MSG_IGNORE
,
2741 PKT_STR
, randomstr
, PKT_END
);
2744 logevent("Sending password with camouflage packets");
2745 ssh_pkt_defersend();
2747 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2749 * The server can't deal with SSH1_MSG_IGNORE
2750 * but can deal with padded passwords, so we
2751 * can use the secondary defence.
2757 len
= strlen(password
);
2758 if (len
< sizeof(string
)) {
2760 strcpy(string
, password
);
2761 len
++; /* cover the zero byte */
2762 while (len
< sizeof(string
)) {
2763 string
[len
++] = (char) random_byte();
2768 logevent("Sending length-padded password");
2769 send_packet(pwpkt_type
, PKT_INT
, len
,
2770 PKT_DATA
, s
, len
, PKT_END
);
2773 * The server has _both_
2774 * BUG_CHOKES_ON_SSH1_IGNORE and
2775 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2776 * therefore nothing we can do.
2779 len
= strlen(password
);
2780 logevent("Sending unpadded password");
2781 send_packet(pwpkt_type
, PKT_INT
, len
,
2782 PKT_DATA
, password
, len
, PKT_END
);
2785 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2788 logevent("Sent password");
2789 memset(password
, 0, strlen(password
));
2791 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2792 if (flags
& FLAG_VERBOSE
)
2793 c_write_str("Access denied\r\n");
2794 logevent("Authentication refused");
2795 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2796 logevent("Received disconnect request");
2797 ssh_state
= SSH_STATE_CLOSED
;
2799 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2800 bombout(("Strange packet received, type %d", pktin
.type
));
2805 logevent("Authentication successful");
2810 void sshfwd_close(struct ssh_channel
*c
)
2812 if (c
&& !c
->closes
) {
2814 * If the channel's remoteid is -1, we have sent
2815 * CHANNEL_OPEN for this channel, but it hasn't even been
2816 * acknowledged by the server. So we must set a close flag
2817 * on it now, and then when the server acks the channel
2818 * open, we can close it then.
2820 if (((int)c
->remoteid
) != -1) {
2821 if (ssh_version
== 1) {
2822 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2825 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2826 ssh2_pkt_adduint32(c
->remoteid
);
2831 if (c
->type
== CHAN_X11
) {
2833 logevent("Forwarded X11 connection terminated");
2834 } else if (c
->type
== CHAN_SOCKDATA
||
2835 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2837 logevent("Forwarded port closed");
2842 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2844 if (ssh_version
== 1) {
2845 send_packet(SSH1_MSG_CHANNEL_DATA
,
2846 PKT_INT
, c
->remoteid
,
2847 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2849 * In SSH1 we can return 0 here - implying that forwarded
2850 * connections are never individually throttled - because
2851 * the only circumstance that can cause throttling will be
2852 * the whole SSH connection backing up, in which case
2853 * _everything_ will be throttled as a whole.
2857 ssh2_add_channel_data(c
, buf
, len
);
2858 return ssh2_try_send(c
);
2862 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2864 if (ssh_version
== 1) {
2865 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2866 c
->v
.v1
.throttling
= 0;
2870 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2874 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2880 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2883 if (ssh_state
== SSH_STATE_CLOSED
)
2886 if (cfg
.agentfwd
&& agent_exists()) {
2887 logevent("Requesting agent forwarding");
2888 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2892 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2893 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2894 bombout(("Protocol confusion"));
2896 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2897 logevent("Agent forwarding refused");
2899 logevent("Agent forwarding enabled");
2900 ssh_agentfwd_enabled
= TRUE
;
2904 if (cfg
.x11_forward
) {
2905 char proto
[20], data
[64];
2906 logevent("Requesting X11 forwarding");
2907 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2908 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2909 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2910 PKT_STR
, proto
, PKT_STR
, data
,
2911 PKT_INT
, 0, PKT_END
);
2913 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2914 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2919 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2920 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2921 bombout(("Protocol confusion"));
2923 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2924 logevent("X11 forwarding refused");
2926 logevent("X11 forwarding enabled");
2927 ssh_X11_fwd_enabled
= TRUE
;
2935 int sport
,dport
,sserv
,dserv
;
2936 char sports
[256], dports
[256], host
[256];
2940 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2941 /* Add port forwardings. */
2946 while (*e
&& *e
!= '\t')
2952 while (*e
&& *e
!= ':')
2962 dport
= atoi(dports
);
2966 se
= getservbyname(dports
, NULL
);
2968 dport
= ntohs(se
->s_port
);
2971 "Service lookup failed for destination port \"%s\"",
2976 sport
= atoi(sports
);
2980 se
= getservbyname(sports
, NULL
);
2982 sport
= ntohs(se
->s_port
);
2985 "Service lookup failed for source port \"%s\"",
2990 if (sport
&& dport
) {
2992 pfd_addforward(host
, dport
, sport
);
2993 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
2994 " %s:%.*s%.*s%d%.*s",
2995 sserv ?
strlen(sports
) : 0, sports
,
2996 sserv
, "(", sport
, sserv
, ")",
2998 dserv ?
strlen(dports
) : 0, dports
,
2999 dserv
, "(", dport
, dserv
, ")");
3002 struct ssh_rportfwd
*pf
;
3003 pf
= smalloc(sizeof(*pf
));
3004 strcpy(pf
->dhost
, host
);
3006 if (add234(ssh_rportfwds
, pf
) != pf
) {
3008 "Duplicate remote port forwarding to %s:%d",
3013 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
3014 " forward to %s:%.*s%.*s%d%.*s",
3015 sserv ?
strlen(sports
) : 0, sports
,
3016 sserv
, "(", sport
, sserv
, ")",
3018 dserv ?
strlen(dports
) : 0, dports
,
3019 dserv
, "(", dport
, dserv
, ")");
3021 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
3029 if (pktin
.type
!= SSH1_SMSG_SUCCESS
3030 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
3031 bombout(("Protocol confusion"));
3033 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3034 c_write_str("Server refused port forwarding\r\n");
3035 ssh_editing
= ssh_echoing
= 1;
3037 logevent("Remote port forwarding enabled");
3045 send_packet(SSH1_CMSG_REQUEST_PTY
,
3046 PKT_STR
, cfg
.termtype
,
3047 PKT_INT
, rows
, PKT_INT
, cols
,
3048 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3049 ssh_state
= SSH_STATE_INTERMED
;
3053 if (pktin
.type
!= SSH1_SMSG_SUCCESS
3054 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
3055 bombout(("Protocol confusion"));
3057 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3058 c_write_str("Server refused to allocate pty\r\n");
3059 ssh_editing
= ssh_echoing
= 1;
3061 logevent("Allocated pty");
3063 ssh_editing
= ssh_echoing
= 1;
3066 if (cfg
.compression
) {
3067 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3071 if (pktin
.type
!= SSH1_SMSG_SUCCESS
3072 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
3073 bombout(("Protocol confusion"));
3075 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3076 c_write_str("Server refused to compress\r\n");
3078 logevent("Started compression");
3079 ssh1_compressing
= TRUE
;
3080 zlib_compress_init();
3081 zlib_decompress_init();
3085 * Start the shell or command.
3087 * Special case: if the first-choice command is an SSH2
3088 * subsystem (hence not usable here) and the second choice
3089 * exists, we fall straight back to that.
3092 char *cmd
= cfg
.remote_cmd_ptr
;
3094 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
3095 cmd
= cfg
.remote_cmd_ptr2
;
3096 ssh_fallback_cmd
= TRUE
;
3099 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3101 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3102 logevent("Started session");
3105 ssh_state
= SSH_STATE_SESSION
;
3109 ssh_special(TS_EOF
);
3111 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
3113 ssh_channels
= newtree234(ssh_channelcmp
);
3117 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3118 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3119 long len
= GET_32BIT(pktin
.body
);
3121 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3122 pktin
.body
+ 4, len
);
3123 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3124 ssh1_stdout_throttling
= 1;
3127 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
3128 ssh_state
= SSH_STATE_CLOSED
;
3129 logevent("Received disconnect request");
3131 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3132 /* Remote side is trying to open a channel to talk to our
3133 * X-Server. Give them back a local channel number. */
3134 struct ssh_channel
*c
;
3136 logevent("Received X11 connect request");
3137 /* Refuse if X11 forwarding is disabled. */
3138 if (!ssh_X11_fwd_enabled
) {
3139 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3140 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3141 logevent("Rejected X11 connect request");
3143 c
= smalloc(sizeof(struct ssh_channel
));
3145 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
3146 logevent("opening X11 forward connection failed");
3148 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3149 PKT_INT
, GET_32BIT(pktin
.body
),
3153 ("opening X11 forward connection succeeded");
3154 c
->remoteid
= GET_32BIT(pktin
.body
);
3155 c
->localid
= alloc_channel_id();
3157 c
->v
.v1
.throttling
= 0;
3158 c
->type
= CHAN_X11
; /* identify channel type */
3159 add234(ssh_channels
, c
);
3160 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3161 PKT_INT
, c
->remoteid
, PKT_INT
,
3162 c
->localid
, PKT_END
);
3163 logevent("Opened X11 forward channel");
3166 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3167 /* Remote side is trying to open a channel to talk to our
3168 * agent. Give them back a local channel number. */
3169 struct ssh_channel
*c
;
3171 /* Refuse if agent forwarding is disabled. */
3172 if (!ssh_agentfwd_enabled
) {
3173 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3174 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3176 c
= smalloc(sizeof(struct ssh_channel
));
3177 c
->remoteid
= GET_32BIT(pktin
.body
);
3178 c
->localid
= alloc_channel_id();
3180 c
->v
.v1
.throttling
= 0;
3181 c
->type
= CHAN_AGENT
; /* identify channel type */
3182 c
->u
.a
.lensofar
= 0;
3183 add234(ssh_channels
, c
);
3184 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3185 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3188 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3189 /* Remote side is trying to open a channel to talk to a
3190 * forwarded port. Give them back a local channel number. */
3191 struct ssh_channel
*c
;
3192 struct ssh_rportfwd pf
;
3194 char host
[256], buf
[1024];
3196 c
= smalloc(sizeof(struct ssh_channel
));
3198 hostsize
= GET_32BIT(pktin
.body
+4);
3199 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
3200 if (h
+1 < host
+sizeof(host
))
3205 port
= GET_32BIT(p
);
3207 strcpy(pf
.dhost
, host
);
3210 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
3211 sprintf(buf
, "Rejected remote port open request for %s:%d",
3214 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3215 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3217 sprintf(buf
, "Received remote port open request for %s:%d",
3220 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3223 sprintf(buf
, "Port open failed: %s", e
);
3226 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3227 PKT_INT
, GET_32BIT(pktin
.body
),
3230 c
->remoteid
= GET_32BIT(pktin
.body
);
3231 c
->localid
= alloc_channel_id();
3233 c
->v
.v1
.throttling
= 0;
3234 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3235 add234(ssh_channels
, c
);
3236 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3237 PKT_INT
, c
->remoteid
, PKT_INT
,
3238 c
->localid
, PKT_END
);
3239 logevent("Forwarded port opened successfully");
3243 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3244 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3245 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3246 struct ssh_channel
*c
;
3248 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3249 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3250 c
->remoteid
= localid
;
3251 c
->type
= CHAN_SOCKDATA
;
3252 c
->v
.v1
.throttling
= 0;
3253 pfd_confirm(c
->u
.pfd
.s
);
3256 if (c
&& c
->closes
) {
3258 * We have a pending close on this channel,
3259 * which we decided on before the server acked
3260 * the channel open. So now we know the
3261 * remoteid, we can close it again.
3263 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
3267 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3268 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3269 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3270 struct ssh_channel
*c
;
3272 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3273 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3274 logevent("Forwarded connection refused by server");
3275 pfd_close(c
->u
.pfd
.s
);
3276 del234(ssh_channels
, c
);
3280 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3281 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3282 /* Remote side closes a channel. */
3283 unsigned i
= GET_32BIT(pktin
.body
);
3284 struct ssh_channel
*c
;
3285 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3289 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3290 if (!(c
->closes
& closetype
))
3291 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
3293 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3294 logevent("Forwarded X11 connection terminated");
3295 assert(c
->u
.x11
.s
!= NULL
);
3296 x11_close(c
->u
.x11
.s
);
3299 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3300 logevent("Forwarded port closed");
3301 assert(c
->u
.pfd
.s
!= NULL
);
3302 pfd_close(c
->u
.pfd
.s
);
3305 c
->closes
|= closetype
;
3306 if (c
->closes
== 3) {
3307 del234(ssh_channels
, c
);
3311 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3312 /* Data sent down one of our channels. */
3313 int i
= GET_32BIT(pktin
.body
);
3314 int len
= GET_32BIT(pktin
.body
+ 4);
3315 unsigned char *p
= pktin
.body
+ 8;
3316 struct ssh_channel
*c
;
3317 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3322 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3325 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3328 /* Data for an agent message. Buffer it. */
3330 if (c
->u
.a
.lensofar
< 4) {
3331 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3332 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3336 c
->u
.a
.lensofar
+= l
;
3338 if (c
->u
.a
.lensofar
== 4) {
3340 4 + GET_32BIT(c
->u
.a
.msglen
);
3341 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3342 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3344 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3346 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3348 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3352 c
->u
.a
.lensofar
+= l
;
3354 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3355 void *reply
, *sentreply
;
3357 agent_query(c
->u
.a
.message
,
3358 c
->u
.a
.totallen
, &reply
,
3363 /* Fake SSH_AGENT_FAILURE. */
3364 sentreply
= "\0\0\0\1\5";
3367 send_packet(SSH1_MSG_CHANNEL_DATA
,
3368 PKT_INT
, c
->remoteid
,
3370 PKT_DATA
, sentreply
, replylen
,
3374 sfree(c
->u
.a
.message
);
3375 c
->u
.a
.lensofar
= 0;
3378 bufsize
= 0; /* agent channels never back up */
3381 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3382 c
->v
.v1
.throttling
= 1;
3386 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3387 /* may be from EXEC_SHELL on some servers */
3388 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3389 /* may be from EXEC_SHELL on some servers
3390 * if no pty is available or in other odd cases. Ignore */
3391 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3393 ssh_exitcode
= GET_32BIT(pktin
.body
);
3394 sprintf(buf
, "Server sent command exit status %d",
3397 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3399 * In case `helpful' firewalls or proxies tack
3400 * extra human-readable text on the end of the
3401 * session which we might mistake for another
3402 * encrypted packet, we close the session once
3403 * we've sent EXIT_CONFIRMATION.
3405 ssh_state
= SSH_STATE_CLOSED
;
3408 bombout(("Strange packet received: type %d", pktin
.type
));
3413 int len
= min(inlen
, 512);
3414 send_packet(SSH1_CMSG_STDIN_DATA
,
3415 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3426 * Utility routine for decoding comma-separated strings in KEXINIT.
3428 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3430 int needlen
= strlen(needle
);
3433 * Is it at the start of the string?
3435 if (haylen
>= needlen
&& /* haystack is long enough */
3436 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3437 (haylen
== needlen
|| haystack
[needlen
] == ',')
3438 /* either , or EOS follows */
3442 * If not, search for the next comma and resume after that.
3443 * If no comma found, terminate.
3445 while (haylen
> 0 && *haystack
!= ',')
3446 haylen
--, haystack
++;
3449 haylen
--, haystack
++; /* skip over comma itself */
3454 * SSH2 key creation method.
3456 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3460 /* First 20 bytes. */
3463 SHA_Bytes(&s
, H
, 20);
3464 SHA_Bytes(&s
, &chr
, 1);
3465 SHA_Bytes(&s
, sessid
, 20);
3466 SHA_Final(&s
, keyspace
);
3467 /* Next 20 bytes. */
3470 SHA_Bytes(&s
, H
, 20);
3471 SHA_Bytes(&s
, keyspace
, 20);
3472 SHA_Final(&s
, keyspace
+ 20);
3476 * Handle the SSH2 transport layer.
3478 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3480 static int i
, j
, len
, nbits
, pbits
, warn
;
3482 static Bignum p
, g
, e
, f
, K
;
3483 static int kex_init_value
, kex_reply_value
;
3484 static const struct ssh_mac
**maclist
;
3486 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3487 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3488 static const struct ssh_mac
*csmac_tobe
= NULL
;
3489 static const struct ssh_mac
*scmac_tobe
= NULL
;
3490 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3491 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3492 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3493 static int hostkeylen
, siglen
;
3494 static void *hkey
; /* actual host key */
3495 static unsigned char exchange_hash
[20];
3496 static unsigned char keyspace
[40];
3497 static int n_preferred_ciphers
;
3498 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3499 static const struct ssh_compress
*preferred_comp
;
3500 static int cipherstr_started
;
3501 static int first_kex
;
3508 * Set up the preferred ciphers. (NULL => warn below here)
3510 n_preferred_ciphers
= 0;
3511 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3512 switch (cfg
.ssh_cipherlist
[i
]) {
3513 case CIPHER_BLOWFISH
:
3514 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3515 n_preferred_ciphers
++;
3518 if (cfg
.ssh2_des_cbc
) {
3519 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3520 n_preferred_ciphers
++;
3524 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3525 n_preferred_ciphers
++;
3528 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3529 n_preferred_ciphers
++;
3532 /* Flag for later. Don't bother if it's the last in
3534 if (i
< CIPHER_MAX
- 1) {
3535 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3536 n_preferred_ciphers
++;
3543 * Set up preferred compression.
3545 if (cfg
.compression
)
3546 preferred_comp
= &ssh_zlib
;
3548 preferred_comp
= &ssh_comp_none
;
3551 * Be prepared to work around the buggy MAC problem.
3553 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3554 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3556 maclist
= macs
, nmacs
= lenof(macs
);
3560 * Construct and send our key exchange packet.
3562 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3563 for (i
= 0; i
< 16; i
++)
3564 ssh2_pkt_addbyte((unsigned char) random_byte());
3565 /* List key exchange algorithms. */
3566 ssh2_pkt_addstring_start();
3567 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3568 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3569 if (i
< lenof(kex_algs
) - 1)
3570 ssh2_pkt_addstring_str(",");
3572 /* List server host key algorithms. */
3573 ssh2_pkt_addstring_start();
3574 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3575 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3576 if (i
< lenof(hostkey_algs
) - 1)
3577 ssh2_pkt_addstring_str(",");
3579 /* List client->server encryption algorithms. */
3580 ssh2_pkt_addstring_start();
3581 cipherstr_started
= 0;
3582 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3583 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3584 if (!c
) continue; /* warning flag */
3585 for (j
= 0; j
< c
->nciphers
; j
++) {
3586 if (cipherstr_started
)
3587 ssh2_pkt_addstring_str(",");
3588 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3589 cipherstr_started
= 1;
3592 /* List server->client encryption algorithms. */
3593 ssh2_pkt_addstring_start();
3594 cipherstr_started
= 0;
3595 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3596 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3597 if (!c
) continue; /* warning flag */
3598 for (j
= 0; j
< c
->nciphers
; j
++) {
3599 if (cipherstr_started
)
3600 ssh2_pkt_addstring_str(",");
3601 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3602 cipherstr_started
= 1;
3605 /* List client->server MAC algorithms. */
3606 ssh2_pkt_addstring_start();
3607 for (i
= 0; i
< nmacs
; i
++) {
3608 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3610 ssh2_pkt_addstring_str(",");
3612 /* List server->client MAC algorithms. */
3613 ssh2_pkt_addstring_start();
3614 for (i
= 0; i
< nmacs
; i
++) {
3615 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3617 ssh2_pkt_addstring_str(",");
3619 /* List client->server compression algorithms. */
3620 ssh2_pkt_addstring_start();
3621 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3622 const struct ssh_compress
*c
=
3623 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3624 ssh2_pkt_addstring_str(c
->name
);
3625 if (i
< lenof(compressions
))
3626 ssh2_pkt_addstring_str(",");
3628 /* List server->client compression algorithms. */
3629 ssh2_pkt_addstring_start();
3630 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3631 const struct ssh_compress
*c
=
3632 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3633 ssh2_pkt_addstring_str(c
->name
);
3634 if (i
< lenof(compressions
))
3635 ssh2_pkt_addstring_str(",");
3637 /* List client->server languages. Empty list. */
3638 ssh2_pkt_addstring_start();
3639 /* List server->client languages. Empty list. */
3640 ssh2_pkt_addstring_start();
3641 /* First KEX packet does _not_ follow, because we're not that brave. */
3642 ssh2_pkt_addbool(FALSE
);
3644 ssh2_pkt_adduint32(0);
3646 exhash
= exhashbase
;
3647 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3653 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3656 * Now examine the other side's KEXINIT to see what we're up
3659 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3660 bombout(("expected key exchange packet from server"));
3665 cscipher_tobe
= NULL
;
3666 sccipher_tobe
= NULL
;
3671 pktin
.savedpos
+= 16; /* skip garbage cookie */
3672 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3673 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3674 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3679 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3680 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3681 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3682 hostkey
= hostkey_algs
[i
];
3686 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3688 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3689 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3693 for (j
= 0; j
< c
->nciphers
; j
++) {
3694 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3695 cscipher_tobe
= c
->list
[j
];
3700 if (cscipher_tobe
) {
3702 askcipher(cscipher_tobe
->name
, 1);
3706 if (!cscipher_tobe
) {
3707 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3711 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3713 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3714 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3718 for (j
= 0; j
< c
->nciphers
; j
++) {
3719 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3720 sccipher_tobe
= c
->list
[j
];
3725 if (sccipher_tobe
) {
3727 askcipher(sccipher_tobe
->name
, 2);
3731 if (!sccipher_tobe
) {
3732 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3736 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3737 for (i
= 0; i
< nmacs
; i
++) {
3738 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3739 csmac_tobe
= maclist
[i
];
3743 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3744 for (i
= 0; i
< nmacs
; i
++) {
3745 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3746 scmac_tobe
= maclist
[i
];
3750 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3751 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3752 const struct ssh_compress
*c
=
3753 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3754 if (in_commasep_string(c
->name
, str
, len
)) {
3759 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3760 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3761 const struct ssh_compress
*c
=
3762 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3763 if (in_commasep_string(c
->name
, str
, len
)) {
3770 * Work out the number of bits of key we will need from the key
3771 * exchange. We start with the maximum key length of either
3777 csbits
= cscipher_tobe
->keylen
;
3778 scbits
= sccipher_tobe
->keylen
;
3779 nbits
= (csbits
> scbits ? csbits
: scbits
);
3781 /* The keys only have 160-bit entropy, since they're based on
3782 * a SHA-1 hash. So cap the key size at 160 bits. */
3787 * If we're doing Diffie-Hellman group exchange, start by
3788 * requesting a group.
3790 if (kex
== &ssh_diffiehellman_gex
) {
3791 logevent("Doing Diffie-Hellman group exchange");
3792 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3794 * Work out how big a DH group we will need to allow that
3797 pbits
= 512 << ((nbits
- 1) / 64);
3798 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3799 ssh2_pkt_adduint32(pbits
);
3803 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3804 bombout(("expected key exchange group packet from server"));
3807 p
= ssh2_pkt_getmp();
3808 g
= ssh2_pkt_getmp();
3809 dh_setup_group(p
, g
);
3810 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3811 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3813 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3815 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3816 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3819 logevent("Doing Diffie-Hellman key exchange");
3821 * Now generate and send e for Diffie-Hellman.
3823 e
= dh_create_e(nbits
* 2);
3824 ssh2_pkt_init(kex_init_value
);
3829 if (pktin
.type
!= kex_reply_value
) {
3830 bombout(("expected key exchange reply packet from server"));
3833 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3834 f
= ssh2_pkt_getmp();
3835 ssh2_pkt_getstring(&sigdata
, &siglen
);
3839 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3840 if (kex
== &ssh_diffiehellman_gex
) {
3841 sha_uint32(&exhash
, pbits
);
3842 sha_mpint(&exhash
, p
);
3843 sha_mpint(&exhash
, g
);
3845 sha_mpint(&exhash
, e
);
3846 sha_mpint(&exhash
, f
);
3847 sha_mpint(&exhash
, K
);
3848 SHA_Final(&exhash
, exchange_hash
);
3853 debug(("Exchange hash is:\n"));
3854 dmemdump(exchange_hash
, 20);
3857 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3859 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3860 bombout(("Server's host key did not match the signature supplied"));
3865 * Authenticate remote host: verify host key. (We've already
3866 * checked the signature of the exchange hash.)
3868 keystr
= hostkey
->fmtkey(hkey
);
3869 fingerprint
= hostkey
->fingerprint(hkey
);
3870 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3871 keystr
, fingerprint
);
3872 if (first_kex
) { /* don't bother logging this in rekeys */
3873 logevent("Host key fingerprint is:");
3874 logevent(fingerprint
);
3878 hostkey
->freekey(hkey
);
3881 * Send SSH2_MSG_NEWKEYS.
3883 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3887 * Expect SSH2_MSG_NEWKEYS from server.
3890 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3891 bombout(("expected new-keys packet from server"));
3896 * Create and initialise session keys.
3898 cscipher
= cscipher_tobe
;
3899 sccipher
= sccipher_tobe
;
3902 cscomp
= cscomp_tobe
;
3903 sccomp
= sccomp_tobe
;
3904 cscomp
->compress_init();
3905 sccomp
->decompress_init();
3907 * Set IVs after keys. Here we use the exchange hash from the
3908 * _first_ key exchange.
3911 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3912 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3913 cscipher
->setcskey(keyspace
);
3914 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3915 sccipher
->setsckey(keyspace
);
3916 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3917 cscipher
->setcsiv(keyspace
);
3918 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3919 sccipher
->setsciv(keyspace
);
3920 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3921 csmac
->setcskey(keyspace
);
3922 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3923 scmac
->setsckey(keyspace
);
3926 * If this is the first key exchange phase, we must pass the
3927 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3928 * wants to see it but because it will need time to initialise
3929 * itself before it sees an actual packet. In subsequent key
3930 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3931 * it would only confuse the layer above.
3939 * Now we're encrypting. Begin returning 1 to the protocol main
3940 * function so that other things can run on top of the
3941 * transport. If we ever see a KEXINIT, we must go back to the
3944 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3947 logevent("Server initiated key re-exchange");
3948 goto begin_key_exchange
;
3954 * Add data to an SSH2 channel output buffer.
3956 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3959 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3963 * Attempt to send data on an SSH2 channel.
3965 static int ssh2_try_send(struct ssh_channel
*c
)
3967 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3970 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3971 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3972 len
= c
->v
.v2
.remwindow
;
3973 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3974 len
= c
->v
.v2
.remmaxpkt
;
3975 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3976 ssh2_pkt_adduint32(c
->remoteid
);
3977 ssh2_pkt_addstring_start();
3978 ssh2_pkt_addstring_data(data
, len
);
3980 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3981 c
->v
.v2
.remwindow
-= len
;
3985 * After having sent as much data as we can, return the amount
3988 return bufchain_size(&c
->v
.v2
.outbuffer
);
3992 * Potentially enlarge the window on an SSH2 channel.
3994 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3997 * Never send WINDOW_ADJUST for a channel that the remote side
3998 * already thinks it's closed; there's no point, since it won't
3999 * be sending any more data anyway.
4004 if (newwin
> c
->v
.v2
.locwindow
) {
4005 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4006 ssh2_pkt_adduint32(c
->remoteid
);
4007 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
4009 c
->v
.v2
.locwindow
= newwin
;
4014 * Handle the SSH2 userauth and connection layers.
4016 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
4019 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4021 AUTH_KEYBOARD_INTERACTIVE
4025 AUTH_TYPE_PUBLICKEY
,
4026 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4027 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4029 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4030 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4032 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4033 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4034 static int kbd_inter_running
;
4035 static int we_are_in
;
4036 static int num_prompts
, curr_prompt
, echo
;
4037 static char username
[100];
4038 static int got_username
;
4039 static char pwprompt
[200];
4040 static char password
[100];
4041 static void *publickey_blob
;
4042 static int publickey_bloblen
;
4047 * Request userauth protocol, and await a response to it.
4049 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
4050 ssh2_pkt_addstring("ssh-userauth");
4052 crWaitUntilV(ispkt
);
4053 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4054 bombout(("Server refused user authentication protocol"));
4059 * We repeat this whole loop, including the username prompt,
4060 * until we manage a successful authentication. If the user
4061 * types the wrong _password_, they are sent back to the
4062 * beginning to try another username. (If they specify a
4063 * username in the config, they are never asked, even if they
4064 * do give a wrong password.)
4066 * I think this best serves the needs of
4068 * - the people who have no configuration, no keys, and just
4069 * want to try repeated (username,password) pairs until they
4070 * type both correctly
4072 * - people who have keys and configuration but occasionally
4073 * need to fall back to passwords
4075 * - people with a key held in Pageant, who might not have
4076 * logged in to a particular machine before; so they want to
4077 * type a username, and then _either_ their key will be
4078 * accepted, _or_ they will type a password. If they mistype
4079 * the username they will want to be able to get back and
4083 got_username
= FALSE
;
4092 if (got_username
&& !cfg
.change_username
) {
4094 * We got a username last time round this loop, and
4095 * with change_username turned off we don't try to get
4098 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
4099 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4100 if (!ssh_get_line("login as: ",
4101 username
, sizeof(username
), FALSE
)) {
4103 * get_line failed to get a username.
4106 logevent("No username provided. Abandoning session.");
4107 ssh_state
= SSH_STATE_CLOSED
;
4111 c_write_str("login as: ");
4114 crWaitUntilV(!ispkt
);
4116 switch (c
= *in
++) {
4125 c_write_str("\b \b");
4132 c_write_str("\b \b");
4141 if (((c
>= ' ' && c
<= '~') ||
4142 ((unsigned char) c
>= 160))
4143 && pos
< sizeof(username
)-1) {
4144 username
[pos
++] = c
;
4151 c_write_str("\r\n");
4152 username
[strcspn(username
, "\n\r")] = '\0';
4155 strncpy(username
, cfg
.username
, 99);
4156 username
[99] = '\0';
4157 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4158 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
4162 got_username
= TRUE
;
4165 * Send an authentication request using method "none": (a)
4166 * just in case it succeeds, and (b) so that we know what
4167 * authentication methods we can usefully try next.
4169 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4171 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4172 ssh2_pkt_addstring(username
);
4173 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4174 ssh2_pkt_addstring("none"); /* method */
4176 type
= AUTH_TYPE_NONE
;
4180 tried_pubkey_config
= FALSE
;
4181 tried_agent
= FALSE
;
4182 tried_keyb_inter
= FALSE
;
4183 kbd_inter_running
= FALSE
;
4184 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4187 logeventf("Reading private key file \"%.150s\"", cfg
.keyfile
);
4188 keytype
= key_type(cfg
.keyfile
);
4189 if (keytype
== SSH_KEYTYPE_SSH2
)
4190 publickey_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4191 &publickey_bloblen
);
4194 logeventf("Unable to use this key file (%s)",
4195 key_type_to_str(keytype
));
4196 sprintf(msgbuf
, "Unable to use key file \"%.150s\" (%s)\r\n",
4197 cfg
.keyfile
, key_type_to_str(keytype
));
4198 c_write_str(msgbuf
);
4199 publickey_blob
= NULL
;
4202 publickey_blob
= NULL
;
4206 * Wait for the result of the last authentication request.
4209 crWaitUntilV(ispkt
);
4210 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4214 * Don't show the banner if we're operating in
4215 * non-verbose non-interactive mode. (It's probably
4216 * a script, which means nobody will read the
4217 * banner _anyway_, and moreover the printing of
4218 * the banner will screw up processing on the
4219 * output of (say) plink.)
4221 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4222 ssh2_pkt_getstring(&banner
, &size
);
4224 c_write_untrusted(banner
, size
);
4226 crWaitUntilV(ispkt
);
4228 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4229 logevent("Access granted");
4234 if (kbd_inter_running
&&
4235 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4237 * This is either a further set-of-prompts packet
4238 * in keyboard-interactive authentication, or it's
4239 * the same one and we came back here with `gotit'
4240 * set. In the former case, we must reset the
4241 * curr_prompt variable.
4245 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4246 bombout(("Strange packet received during authentication: type %d",
4254 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4255 * we can look at the string in it and know what we can
4256 * helpfully try next.
4258 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4261 ssh2_pkt_getstring(&methods
, &methlen
);
4262 kbd_inter_running
= FALSE
;
4263 if (!ssh2_pkt_getbool()) {
4265 * We have received an unequivocal Access
4266 * Denied. This can translate to a variety of
4269 * - if we'd just tried "none" authentication,
4270 * it's not worth printing anything at all
4272 * - if we'd just tried a public key _offer_,
4273 * the message should be "Server refused our
4274 * key" (or no message at all if the key
4275 * came from Pageant)
4277 * - if we'd just tried anything else, the
4278 * message really should be "Access denied".
4280 * Additionally, if we'd just tried password
4281 * authentication, we should break out of this
4282 * whole loop so as to go back to the username
4285 if (type
== AUTH_TYPE_NONE
) {
4287 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4288 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4289 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4290 c_write_str("Server refused our key\r\n");
4291 logevent("Server refused public key");
4292 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4293 /* server declined keyboard-interactive; ignore */
4295 c_write_str("Access denied\r\n");
4296 logevent("Access denied");
4297 if (type
== AUTH_TYPE_PASSWORD
) {
4303 c_write_str("Further authentication required\r\n");
4304 logevent("Further authentication required");
4308 in_commasep_string("publickey", methods
, methlen
);
4310 in_commasep_string("password", methods
, methlen
);
4311 can_keyb_inter
= cfg
.try_ki_auth
&&
4312 in_commasep_string("keyboard-interactive", methods
, methlen
);
4316 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4318 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
4320 * Attempt public-key authentication using Pageant.
4322 static unsigned char request
[5], *response
, *p
;
4323 static int responselen
;
4324 static int i
, nkeys
;
4325 static int authed
= FALSE
;
4328 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4329 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4333 logevent("Pageant is running. Requesting keys.");
4335 /* Request the keys held by the agent. */
4336 PUT_32BIT(request
, 1);
4337 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4338 agent_query(request
, 5, &r
, &responselen
);
4339 response
= (unsigned char *) r
;
4340 if (response
&& responselen
>= 5 &&
4341 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4343 nkeys
= GET_32BIT(p
);
4347 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
4350 for (i
= 0; i
< nkeys
; i
++) {
4351 static char *pkblob
, *alg
, *commentp
;
4352 static int pklen
, alglen
, commentlen
;
4353 static int siglen
, retlen
, len
;
4354 static char *q
, *agentreq
, *ret
;
4359 sprintf(buf
, "Trying Pageant key #%d", i
);
4362 pklen
= GET_32BIT(p
);
4364 if (publickey_blob
&&
4365 pklen
== publickey_bloblen
&&
4366 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
4367 logevent("This key matches configured key file");
4368 tried_pubkey_config
= 1;
4372 alglen
= GET_32BIT(pkblob
);
4374 commentlen
= GET_32BIT(p
);
4378 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4379 ssh2_pkt_addstring(username
);
4380 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4381 ssh2_pkt_addstring("publickey"); /* method */
4382 ssh2_pkt_addbool(FALSE
); /* no signature included */
4383 ssh2_pkt_addstring_start();
4384 ssh2_pkt_addstring_data(alg
, alglen
);
4385 ssh2_pkt_addstring_start();
4386 ssh2_pkt_addstring_data(pkblob
, pklen
);
4389 crWaitUntilV(ispkt
);
4390 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4391 logevent("Key refused");
4395 if (flags
& FLAG_VERBOSE
) {
4397 ("Authenticating with public key \"");
4398 c_write(commentp
, commentlen
);
4399 c_write_str("\" from agent\r\n");
4403 * Server is willing to accept the key.
4404 * Construct a SIGN_REQUEST.
4406 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4407 ssh2_pkt_addstring(username
);
4408 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4409 ssh2_pkt_addstring("publickey"); /* method */
4410 ssh2_pkt_addbool(TRUE
);
4411 ssh2_pkt_addstring_start();
4412 ssh2_pkt_addstring_data(alg
, alglen
);
4413 ssh2_pkt_addstring_start();
4414 ssh2_pkt_addstring_data(pkblob
, pklen
);
4416 siglen
= pktout
.length
- 5 + 4 + 20;
4417 len
= 1; /* message type */
4418 len
+= 4 + pklen
; /* key blob */
4419 len
+= 4 + siglen
; /* data to sign */
4420 len
+= 4; /* flags */
4421 agentreq
= smalloc(4 + len
);
4422 PUT_32BIT(agentreq
, len
);
4424 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4425 PUT_32BIT(q
, pklen
);
4427 memcpy(q
, pkblob
, pklen
);
4429 PUT_32BIT(q
, siglen
);
4431 /* Now the data to be signed... */
4434 memcpy(q
, ssh2_session_id
, 20);
4436 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4437 q
+= pktout
.length
- 5;
4438 /* And finally the (zero) flags word. */
4440 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4444 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4445 logevent("Sending Pageant's response");
4446 ssh2_add_sigblob(pkblob
, pklen
,
4447 ret
+ 9, GET_32BIT(ret
+ 5));
4453 ("Pageant failed to answer challenge");
4463 if (!method
&& can_pubkey
&& publickey_blob
4464 && !tried_pubkey_config
) {
4465 unsigned char *pub_blob
;
4466 char *algorithm
, *comment
;
4469 tried_pubkey_config
= TRUE
;
4471 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4472 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4475 * Try the public key supplied in the configuration.
4477 * First, offer the public blob to see if the server is
4478 * willing to accept it.
4480 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4483 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4484 ssh2_pkt_addstring(username
);
4485 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4486 ssh2_pkt_addstring("publickey"); /* method */
4487 ssh2_pkt_addbool(FALSE
); /* no signature included */
4488 ssh2_pkt_addstring(algorithm
);
4489 ssh2_pkt_addstring_start();
4490 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4492 logevent("Offered public key"); /* FIXME */
4494 crWaitUntilV(ispkt
);
4495 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4497 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4498 continue; /* key refused; give up on it */
4501 logevent("Offer of public key accepted");
4503 * Actually attempt a serious authentication using
4506 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4508 "Passphrase for key \"%.100s\": ",
4514 c_write_str("Authenticating with public key \"");
4515 c_write_str(comment
);
4516 c_write_str("\"\r\n");
4517 method
= AUTH_PUBLICKEY_FILE
;
4521 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4522 method
= AUTH_KEYBOARD_INTERACTIVE
;
4523 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4524 tried_keyb_inter
= TRUE
;
4526 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4527 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4529 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4530 ssh2_pkt_addstring(username
);
4531 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4532 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4533 ssh2_pkt_addstring(""); /* lang */
4534 ssh2_pkt_addstring("");
4537 crWaitUntilV(ispkt
);
4538 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4539 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4541 logevent("Keyboard-interactive authentication refused");
4542 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4546 kbd_inter_running
= TRUE
;
4550 if (kbd_inter_running
) {
4551 method
= AUTH_KEYBOARD_INTERACTIVE
;
4552 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4553 tried_keyb_inter
= TRUE
;
4555 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4556 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4558 if (curr_prompt
== 0) {
4560 * We've got a fresh USERAUTH_INFO_REQUEST.
4561 * Display header data, and start going through
4564 char *name
, *inst
, *lang
;
4565 int name_len
, inst_len
, lang_len
;
4567 ssh2_pkt_getstring(&name
, &name_len
);
4568 ssh2_pkt_getstring(&inst
, &inst_len
);
4569 ssh2_pkt_getstring(&lang
, &lang_len
);
4571 c_write_untrusted(name
, name_len
);
4575 c_write_untrusted(inst
, inst_len
);
4578 num_prompts
= ssh2_pkt_getuint32();
4582 * If there are prompts remaining in the packet,
4583 * display one and get a response.
4585 if (curr_prompt
< num_prompts
) {
4589 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4590 if (prompt_len
> 0) {
4591 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4592 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4593 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4596 "<server failed to send prompt>: ");
4598 echo
= ssh2_pkt_getbool();
4604 if (!method
&& can_passwd
) {
4605 method
= AUTH_PASSWORD
;
4606 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4607 ssh_pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4608 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4615 if (!ssh_get_line(pwprompt
, password
,
4616 sizeof(password
), TRUE
)) {
4618 * get_line failed to get a password (for
4619 * example because one was supplied on the
4620 * command line which has already failed to
4623 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4624 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4626 ("No more passwords available to try");
4627 ssh2_pkt_addstring("en"); /* language tag */
4629 logevent("Unable to authenticate");
4630 connection_fatal("Unable to authenticate");
4631 ssh_state
= SSH_STATE_CLOSED
;
4638 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4643 crWaitUntilV(!ispkt
);
4645 switch (c
= *in
++) {
4665 if (pos
< sizeof(password
)-1)
4666 password
[pos
++] = c
;
4670 c_write_str("\r\n");
4674 if (method
== AUTH_PUBLICKEY_FILE
) {
4676 * We have our passphrase. Now try the actual authentication.
4678 struct ssh2_userkey
*key
;
4680 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4681 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4682 if (key
== SSH2_WRONG_PASSPHRASE
) {
4683 c_write_str("Wrong passphrase\r\n");
4684 tried_pubkey_config
= FALSE
;
4686 c_write_str("Unable to load private key\r\n");
4687 tried_pubkey_config
= TRUE
;
4689 /* Send a spurious AUTH_NONE to return to the top. */
4690 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4691 ssh2_pkt_addstring(username
);
4692 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4693 ssh2_pkt_addstring("none"); /* method */
4695 type
= AUTH_TYPE_NONE
;
4697 unsigned char *pkblob
, *sigblob
, *sigdata
;
4698 int pkblob_len
, sigblob_len
, sigdata_len
;
4701 * We have loaded the private key and the server
4702 * has announced that it's willing to accept it.
4703 * Hallelujah. Generate a signature and send it.
4705 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4706 ssh2_pkt_addstring(username
);
4707 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4708 ssh2_pkt_addstring("publickey"); /* method */
4709 ssh2_pkt_addbool(TRUE
);
4710 ssh2_pkt_addstring(key
->alg
->name
);
4711 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4712 ssh2_pkt_addstring_start();
4713 ssh2_pkt_addstring_data(pkblob
, pkblob_len
);
4716 * The data to be signed is:
4720 * followed by everything so far placed in the
4723 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4724 sigdata
= smalloc(sigdata_len
);
4725 PUT_32BIT(sigdata
, 20);
4726 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4727 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4729 sigblob
= key
->alg
->sign(key
->data
, sigdata
,
4730 sigdata_len
, &sigblob_len
);
4731 ssh2_add_sigblob(pkblob
, pkblob_len
,
4732 sigblob
, sigblob_len
);
4738 type
= AUTH_TYPE_PUBLICKEY
;
4740 } else if (method
== AUTH_PASSWORD
) {
4742 * We send the password packet lumped tightly together with
4743 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4744 * string long enough to make the total length of the two
4745 * packets constant. This should ensure that a passive
4746 * listener doing traffic analyis can't work out the length
4749 * For this to work, we need an assumption about the
4750 * maximum length of the password packet. I think 256 is
4751 * pretty conservative. Anyone using a password longer than
4752 * that probably doesn't have much to worry about from
4753 * people who find out how long their password is!
4755 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4756 ssh2_pkt_addstring(username
);
4757 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4758 ssh2_pkt_addstring("password");
4759 ssh2_pkt_addbool(FALSE
);
4760 ssh2_pkt_addstring(password
);
4763 * We'll include a string that's an exact multiple of the
4764 * cipher block size. If the cipher is NULL for some
4765 * reason, we don't do this trick at all because we gain
4771 stringlen
= (256 - deferred_len
);
4772 stringlen
+= cscipher
->blksize
- 1;
4773 stringlen
-= (stringlen
% cscipher
->blksize
);
4776 * Temporarily disable actual compression,
4777 * so we can guarantee to get this string
4778 * exactly the length we want it. The
4779 * compression-disabling routine should
4780 * return an integer indicating how many
4781 * bytes we should adjust our string length
4784 stringlen
-= cscomp
->disable_compression();
4786 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4787 ssh2_pkt_addstring_start();
4788 for (i
= 0; i
< stringlen
; i
++) {
4789 char c
= (char) random_byte();
4790 ssh2_pkt_addstring_data(&c
, 1);
4794 ssh_pkt_defersend();
4795 logevent("Sent password");
4796 type
= AUTH_TYPE_PASSWORD
;
4797 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4798 if (curr_prompt
== 0) {
4799 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4800 ssh2_pkt_adduint32(num_prompts
);
4802 if (need_pw
) { /* only add pw if we just got one! */
4803 ssh2_pkt_addstring(password
);
4804 memset(password
, 0, sizeof(password
));
4807 if (curr_prompt
>= num_prompts
) {
4811 * If there are prompts remaining, we set
4812 * `gotit' so that we won't attempt to get
4813 * another packet. Then we go back round the
4814 * loop and will end up retrieving another
4815 * prompt out of the existing packet. Funky or
4820 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4823 ("No supported authentication methods left to try!\r\n");
4825 ("No supported authentications offered. Disconnecting");
4826 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4827 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4829 ("No supported authentication methods available");
4830 ssh2_pkt_addstring("en"); /* language tag */
4832 ssh_state
= SSH_STATE_CLOSED
;
4836 } while (!we_are_in
);
4839 * Now we're authenticated for the connection protocol. The
4840 * connection protocol will automatically have started at this
4841 * point; there's no need to send SERVICE_REQUEST.
4845 * So now create a channel with a session in it.
4847 ssh_channels
= newtree234(ssh_channelcmp
);
4848 mainchan
= smalloc(sizeof(struct ssh_channel
));
4849 mainchan
->localid
= alloc_channel_id();
4850 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4851 ssh2_pkt_addstring("session");
4852 ssh2_pkt_adduint32(mainchan
->localid
);
4853 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4854 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4855 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4857 crWaitUntilV(ispkt
);
4858 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4859 bombout(("Server refused to open a session"));
4861 /* FIXME: error data comes back in FAILURE packet */
4863 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4864 bombout(("Server's channel confirmation cited wrong channel"));
4867 mainchan
->remoteid
= ssh2_pkt_getuint32();
4868 mainchan
->type
= CHAN_MAINSESSION
;
4869 mainchan
->closes
= 0;
4870 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4871 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4872 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4873 add234(ssh_channels
, mainchan
);
4874 logevent("Opened channel for session");
4877 * Potentially enable X11 forwarding.
4879 if (cfg
.x11_forward
) {
4880 char proto
[20], data
[64];
4881 logevent("Requesting X11 forwarding");
4882 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4883 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4884 ssh2_pkt_adduint32(mainchan
->remoteid
);
4885 ssh2_pkt_addstring("x11-req");
4886 ssh2_pkt_addbool(1); /* want reply */
4887 ssh2_pkt_addbool(0); /* many connections */
4888 ssh2_pkt_addstring(proto
);
4889 ssh2_pkt_addstring(data
);
4890 ssh2_pkt_adduint32(0); /* screen number */
4894 crWaitUntilV(ispkt
);
4895 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4896 unsigned i
= ssh2_pkt_getuint32();
4897 struct ssh_channel
*c
;
4898 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4900 continue; /* nonexistent channel */
4901 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4903 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4905 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4906 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4907 bombout(("Unexpected response to X11 forwarding request:"
4908 " packet type %d", pktin
.type
));
4911 logevent("X11 forwarding refused");
4913 logevent("X11 forwarding enabled");
4914 ssh_X11_fwd_enabled
= TRUE
;
4919 * Enable port forwardings.
4922 static char *e
; /* preserve across crReturn */
4925 int sport
,dport
,sserv
,dserv
;
4926 char sports
[256], dports
[256], host
[256];
4930 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4931 /* Add port forwardings. */
4936 while (*e
&& *e
!= '\t')
4942 while (*e
&& *e
!= ':')
4952 dport
= atoi(dports
);
4956 se
= getservbyname(dports
, NULL
);
4958 dport
= ntohs(se
->s_port
);
4961 "Service lookup failed for destination port \"%s\"",
4966 sport
= atoi(sports
);
4970 se
= getservbyname(sports
, NULL
);
4972 sport
= ntohs(se
->s_port
);
4975 "Service lookup failed for source port \"%s\"",
4980 if (sport
&& dport
) {
4982 pfd_addforward(host
, dport
, sport
);
4983 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
4984 " %s:%.*s%.*s%d%.*s",
4985 sserv ?
strlen(sports
) : 0, sports
,
4986 sserv
, "(", sport
, sserv
, ")",
4988 dserv ?
strlen(dports
) : 0, dports
,
4989 dserv
, "(", dport
, dserv
, ")");
4992 struct ssh_rportfwd
*pf
;
4993 pf
= smalloc(sizeof(*pf
));
4994 strcpy(pf
->dhost
, host
);
4997 if (add234(ssh_rportfwds
, pf
) != pf
) {
4999 "Duplicate remote port forwarding to %s:%d",
5004 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
5005 " forward to %s:%.*s%.*s%d%.*s",
5006 sserv ?
strlen(sports
) : 0, sports
,
5007 sserv
, "(", sport
, sserv
, ")",
5009 dserv ?
strlen(dports
) : 0, dports
,
5010 dserv
, "(", dport
, dserv
, ")");
5012 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
5013 ssh2_pkt_addstring("tcpip-forward");
5014 ssh2_pkt_addbool(1);/* want reply */
5015 if (cfg
.rport_acceptall
)
5016 ssh2_pkt_addstring("0.0.0.0");
5018 ssh2_pkt_addstring("127.0.0.1");
5019 ssh2_pkt_adduint32(sport
);
5023 crWaitUntilV(ispkt
);
5024 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5025 unsigned i
= ssh2_pkt_getuint32();
5026 struct ssh_channel
*c
;
5027 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5029 continue;/* nonexistent channel */
5030 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5032 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5034 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5035 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5036 bombout(("Unexpected response to port "
5037 "forwarding request: packet type %d",
5041 logevent("Server refused this port forwarding");
5043 logevent("Remote port forwarding enabled");
5052 * Potentially enable agent forwarding.
5054 if (cfg
.agentfwd
&& agent_exists()) {
5055 logevent("Requesting OpenSSH-style agent forwarding");
5056 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5057 ssh2_pkt_adduint32(mainchan
->remoteid
);
5058 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5059 ssh2_pkt_addbool(1); /* want reply */
5063 crWaitUntilV(ispkt
);
5064 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5065 unsigned i
= ssh2_pkt_getuint32();
5066 struct ssh_channel
*c
;
5067 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5069 continue; /* nonexistent channel */
5070 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5072 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5074 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5075 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5076 bombout(("Unexpected response to agent forwarding request:"
5077 " packet type %d", pktin
.type
));
5080 logevent("Agent forwarding refused");
5082 logevent("Agent forwarding enabled");
5083 ssh_agentfwd_enabled
= TRUE
;
5088 * Now allocate a pty for the session.
5091 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5092 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
5093 ssh2_pkt_addstring("pty-req");
5094 ssh2_pkt_addbool(1); /* want reply */
5095 ssh2_pkt_addstring(cfg
.termtype
);
5096 ssh2_pkt_adduint32(cols
);
5097 ssh2_pkt_adduint32(rows
);
5098 ssh2_pkt_adduint32(0); /* pixel width */
5099 ssh2_pkt_adduint32(0); /* pixel height */
5100 ssh2_pkt_addstring_start();
5101 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5103 ssh_state
= SSH_STATE_INTERMED
;
5106 crWaitUntilV(ispkt
);
5107 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5108 unsigned i
= ssh2_pkt_getuint32();
5109 struct ssh_channel
*c
;
5110 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5112 continue; /* nonexistent channel */
5113 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5115 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5117 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5118 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5119 bombout(("Unexpected response to pty request:"
5120 " packet type %d", pktin
.type
));
5123 c_write_str("Server refused to allocate pty\r\n");
5124 ssh_editing
= ssh_echoing
= 1;
5126 logevent("Allocated pty");
5129 ssh_editing
= ssh_echoing
= 1;
5133 * Start a shell or a remote command. We may have to attempt
5134 * this twice if the config data has provided a second choice
5141 if (ssh_fallback_cmd
) {
5142 subsys
= cfg
.ssh_subsys2
;
5143 cmd
= cfg
.remote_cmd_ptr2
;
5145 subsys
= cfg
.ssh_subsys
;
5146 cmd
= cfg
.remote_cmd_ptr
;
5149 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5150 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
5152 ssh2_pkt_addstring("subsystem");
5153 ssh2_pkt_addbool(1); /* want reply */
5154 ssh2_pkt_addstring(cmd
);
5156 ssh2_pkt_addstring("exec");
5157 ssh2_pkt_addbool(1); /* want reply */
5158 ssh2_pkt_addstring(cmd
);
5160 ssh2_pkt_addstring("shell");
5161 ssh2_pkt_addbool(1); /* want reply */
5165 crWaitUntilV(ispkt
);
5166 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5167 unsigned i
= ssh2_pkt_getuint32();
5168 struct ssh_channel
*c
;
5169 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5171 continue; /* nonexistent channel */
5172 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5174 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5175 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5176 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5177 bombout(("Unexpected response to shell/command request:"
5178 " packet type %d", pktin
.type
));
5182 * We failed to start the command. If this is the
5183 * fallback command, we really are finished; if it's
5184 * not, and if the fallback command exists, try falling
5185 * back to it before complaining.
5187 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
5188 logevent("Primary command failed; attempting fallback");
5189 ssh_fallback_cmd
= TRUE
;
5192 bombout(("Server refused to start a shell/command"));
5195 logevent("Started a shell/command");
5200 ssh_state
= SSH_STATE_SESSION
;
5204 ssh_special(TS_EOF
);
5209 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
5212 static int try_send
;
5216 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5217 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5220 unsigned i
= ssh2_pkt_getuint32();
5221 struct ssh_channel
*c
;
5222 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5224 continue; /* nonexistent channel */
5225 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5226 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
5227 continue; /* extended but not stderr */
5228 ssh2_pkt_getstring(&data
, &length
);
5231 c
->v
.v2
.locwindow
-= length
;
5233 case CHAN_MAINSESSION
:
5235 from_backend(pktin
.type
==
5236 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5240 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5243 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5246 while (length
> 0) {
5247 if (c
->u
.a
.lensofar
< 4) {
5248 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5249 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5253 c
->u
.a
.lensofar
+= l
;
5255 if (c
->u
.a
.lensofar
== 4) {
5257 4 + GET_32BIT(c
->u
.a
.msglen
);
5258 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5259 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5261 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5263 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5265 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5269 c
->u
.a
.lensofar
+= l
;
5271 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5272 void *reply
, *sentreply
;
5274 agent_query(c
->u
.a
.message
,
5275 c
->u
.a
.totallen
, &reply
,
5280 /* Fake SSH_AGENT_FAILURE. */
5281 sentreply
= "\0\0\0\1\5";
5284 ssh2_add_channel_data(c
, sentreply
,
5289 sfree(c
->u
.a
.message
);
5290 c
->u
.a
.lensofar
= 0;
5297 * If we are not buffering too much data,
5298 * enlarge the window again at the remote side.
5300 if (bufsize
< OUR_V2_WINSIZE
)
5301 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5303 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
5304 ssh_state
= SSH_STATE_CLOSED
;
5305 logevent("Received disconnect message");
5307 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5308 unsigned i
= ssh2_pkt_getuint32();
5309 struct ssh_channel
*c
;
5311 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5313 continue; /* nonexistent channel */
5315 if (c
->type
== CHAN_X11
) {
5317 * Remote EOF on an X11 channel means we should
5318 * wrap up and close the channel ourselves.
5320 x11_close(c
->u
.x11
.s
);
5322 } else if (c
->type
== CHAN_AGENT
) {
5324 } else if (c
->type
== CHAN_SOCKDATA
) {
5325 pfd_close(c
->u
.pfd
.s
);
5328 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5329 unsigned i
= ssh2_pkt_getuint32();
5330 struct ssh_channel
*c
;
5332 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5334 continue; /* nonexistent channel */
5335 /* Do pre-close processing on the channel. */
5337 case CHAN_MAINSESSION
:
5338 break; /* nothing to see here, move along */
5340 if (c
->u
.x11
.s
!= NULL
)
5341 x11_close(c
->u
.x11
.s
);
5348 if (c
->u
.pfd
.s
!= NULL
)
5349 pfd_close(c
->u
.pfd
.s
);
5353 if (c
->closes
== 0) {
5354 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5355 ssh2_pkt_adduint32(c
->remoteid
);
5358 del234(ssh_channels
, c
);
5359 bufchain_clear(&c
->v
.v2
.outbuffer
);
5363 * See if that was the last channel left open.
5365 if (count234(ssh_channels
) == 0) {
5368 * We used to send SSH_MSG_DISCONNECT here,
5369 * because I'd believed that _every_ conforming
5370 * SSH2 connection had to end with a disconnect
5371 * being sent by at least one side; apparently
5372 * I was wrong and it's perfectly OK to
5373 * unceremoniously slam the connection shut
5374 * when you're done, and indeed OpenSSH feels
5375 * this is more polite than sending a
5376 * DISCONNECT. So now we don't.
5378 logevent("All channels closed. Disconnecting");
5379 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5380 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5381 ssh2_pkt_addstring("All open channels closed");
5382 ssh2_pkt_addstring("en"); /* language tag */
5385 ssh_state
= SSH_STATE_CLOSED
;
5388 continue; /* remote sends close; ignore (FIXME) */
5389 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5390 unsigned i
= ssh2_pkt_getuint32();
5391 struct ssh_channel
*c
;
5392 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5394 continue; /* nonexistent channel */
5395 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5397 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5398 unsigned i
= ssh2_pkt_getuint32();
5399 struct ssh_channel
*c
;
5400 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5402 continue; /* nonexistent channel */
5403 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5404 continue; /* dunno why they're confirming this */
5405 c
->remoteid
= ssh2_pkt_getuint32();
5406 c
->type
= CHAN_SOCKDATA
;
5407 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
5408 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
5410 pfd_confirm(c
->u
.pfd
.s
);
5413 * We have a pending close on this channel,
5414 * which we decided on before the server acked
5415 * the channel open. So now we know the
5416 * remoteid, we can close it again.
5418 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5419 ssh2_pkt_adduint32(c
->remoteid
);
5422 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5423 unsigned i
= ssh2_pkt_getuint32();
5424 struct ssh_channel
*c
;
5425 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5427 continue; /* nonexistent channel */
5428 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5429 continue; /* dunno why they're failing this */
5431 logevent("Forwarded connection refused by server");
5433 pfd_close(c
->u
.pfd
.s
);
5435 del234(ssh_channels
, c
);
5437 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5440 int typelen
, want_reply
;
5441 struct ssh_channel
*c
;
5443 localid
= ssh2_pkt_getuint32();
5444 ssh2_pkt_getstring(&type
, &typelen
);
5445 want_reply
= ssh2_pkt_getbool();
5448 * First, check that the channel exists. Otherwise,
5449 * we can instantly disconnect with a rude message.
5451 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
5454 sprintf(buf
, "Received channel request for nonexistent"
5455 " channel %d", localid
);
5457 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5458 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5459 ssh2_pkt_addstring(buf
);
5460 ssh2_pkt_addstring("en"); /* language tag */
5462 connection_fatal("%s", buf
);
5463 ssh_state
= SSH_STATE_CLOSED
;
5468 * Having got the channel number, we now look at
5469 * the request type string to see if it's something
5472 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5474 /* We recognise "exit-status" on the primary channel. */
5476 ssh_exitcode
= ssh2_pkt_getuint32();
5477 sprintf(buf
, "Server sent command exit status %d",
5481 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS
);
5482 ssh2_pkt_adduint32(c
->remoteid
);
5487 * This is a channel request we don't know
5488 * about, so we now either ignore the request
5489 * or respond with CHANNEL_FAILURE, depending
5493 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
5494 ssh2_pkt_adduint32(c
->remoteid
);
5498 } else if (pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5500 int typelen
, want_reply
;
5502 ssh2_pkt_getstring(&type
, &typelen
);
5503 want_reply
= ssh2_pkt_getbool();
5506 * We currently don't support any global requests
5507 * at all, so we either ignore the request or
5508 * respond with REQUEST_FAILURE, depending on
5512 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
5515 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5519 struct ssh_channel
*c
;
5520 unsigned remid
, winsize
, pktsize
;
5521 ssh2_pkt_getstring(&type
, &typelen
);
5522 c
= smalloc(sizeof(struct ssh_channel
));
5524 remid
= ssh2_pkt_getuint32();
5525 winsize
= ssh2_pkt_getuint32();
5526 pktsize
= ssh2_pkt_getuint32();
5528 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5529 if (!ssh_X11_fwd_enabled
)
5530 error
= "X11 forwarding is not enabled";
5531 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
5533 error
= "Unable to open an X11 connection";
5537 } else if (typelen
== 15 &&
5538 !memcmp(type
, "forwarded-tcpip", 15)) {
5539 struct ssh_rportfwd pf
, *realpf
;
5542 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
5543 pf
.sport
= ssh2_pkt_getuint32();
5544 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
5545 if (realpf
== NULL
) {
5546 error
= "Remote port is not recognised";
5548 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5551 sprintf(buf
, "Received remote port open request for %s:%d",
5552 realpf
->dhost
, realpf
->dport
);
5555 sprintf(buf
, "Port open failed: %s", e
);
5557 error
= "Port open failed";
5559 logevent("Forwarded port opened successfully");
5560 c
->type
= CHAN_SOCKDATA
;
5563 } else if (typelen
== 22 &&
5564 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5565 if (!ssh_agentfwd_enabled
)
5566 error
= "Agent forwarding is not enabled";
5568 c
->type
= CHAN_AGENT
; /* identify channel type */
5569 c
->u
.a
.lensofar
= 0;
5572 error
= "Unsupported channel type requested";
5575 c
->remoteid
= remid
;
5577 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5578 ssh2_pkt_adduint32(c
->remoteid
);
5579 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5580 ssh2_pkt_addstring(error
);
5581 ssh2_pkt_addstring("en"); /* language tag */
5585 c
->localid
= alloc_channel_id();
5587 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5588 c
->v
.v2
.remwindow
= winsize
;
5589 c
->v
.v2
.remmaxpkt
= pktsize
;
5590 bufchain_init(&c
->v
.v2
.outbuffer
);
5591 add234(ssh_channels
, c
);
5592 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5593 ssh2_pkt_adduint32(c
->remoteid
);
5594 ssh2_pkt_adduint32(c
->localid
);
5595 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5596 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5600 bombout(("Strange packet received: type %d", pktin
.type
));
5605 * We have spare data. Add it to the channel buffer.
5607 ssh2_add_channel_data(mainchan
, in
, inlen
);
5612 struct ssh_channel
*c
;
5614 * Try to send data on all channels if we can.
5616 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5617 int bufsize
= ssh2_try_send(c
);
5620 case CHAN_MAINSESSION
:
5621 /* stdin need not receive an unthrottle
5622 * notification since it will be polled */
5625 x11_unthrottle(c
->u
.x11
.s
);
5628 /* agent sockets are request/response and need no
5629 * buffer management */
5632 pfd_unthrottle(c
->u
.pfd
.s
);
5644 * Handle the top-level SSH2 protocol.
5646 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5648 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5650 do_ssh2_authconn(in
, inlen
, ispkt
);
5654 * Called to set up the connection.
5656 * Returns an error message, or NULL on success.
5658 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5663 if (crypto_startup() == 0)
5664 return "Microsoft high encryption pack not installed!";
5670 ssh1_throttle_count
= 0;
5671 ssh_overall_bufsize
= 0;
5672 ssh_fallback_cmd
= 0;
5674 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5682 * Called to send data down the Telnet connection.
5684 static int ssh_send(char *buf
, int len
)
5686 if (s
== NULL
|| ssh_protocol
== NULL
)
5689 ssh_protocol(buf
, len
, 0);
5691 return ssh_sendbuffer();
5695 * Called to query the current amount of buffered stdin data.
5697 static int ssh_sendbuffer(void)
5701 if (s
== NULL
|| ssh_protocol
== NULL
)
5705 * If the SSH socket itself has backed up, add the total backup
5706 * size on that to any individual buffer on the stdin channel.
5709 if (ssh_throttled_all
)
5710 override_value
= ssh_overall_bufsize
;
5712 if (ssh_version
== 1) {
5713 return override_value
;
5714 } else if (ssh_version
== 2) {
5715 if (!mainchan
|| mainchan
->closes
> 0)
5716 return override_value
;
5718 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5725 * Called to set the size of the window from SSH's POV.
5727 static void ssh_size(void)
5729 switch (ssh_state
) {
5730 case SSH_STATE_BEFORE_SIZE
:
5731 case SSH_STATE_PREPACKET
:
5732 case SSH_STATE_CLOSED
:
5733 break; /* do nothing */
5734 case SSH_STATE_INTERMED
:
5735 size_needed
= TRUE
; /* buffer for later */
5737 case SSH_STATE_SESSION
:
5739 if (ssh_version
== 1) {
5740 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5741 PKT_INT
, rows
, PKT_INT
, cols
,
5742 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5744 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5745 ssh2_pkt_adduint32(mainchan
->remoteid
);
5746 ssh2_pkt_addstring("window-change");
5747 ssh2_pkt_addbool(0);
5748 ssh2_pkt_adduint32(cols
);
5749 ssh2_pkt_adduint32(rows
);
5750 ssh2_pkt_adduint32(0);
5751 ssh2_pkt_adduint32(0);
5760 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5761 * can send an EOF and collect resulting output (e.g. `plink
5764 static void ssh_special(Telnet_Special code
)
5766 if (code
== TS_EOF
) {
5767 if (ssh_state
!= SSH_STATE_SESSION
) {
5769 * Buffer the EOF in case we are pre-SESSION, so we can
5770 * send it as soon as we reach SESSION.
5776 if (ssh_version
== 1) {
5777 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5779 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5780 ssh2_pkt_adduint32(mainchan
->remoteid
);
5783 logevent("Sent EOF message");
5784 } else if (code
== TS_PING
) {
5785 if (ssh_state
== SSH_STATE_CLOSED
5786 || ssh_state
== SSH_STATE_PREPACKET
) return;
5787 if (ssh_version
== 1) {
5788 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5790 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5791 ssh2_pkt_addstring_start();
5799 void *new_sock_channel(Socket s
)
5801 struct ssh_channel
*c
;
5802 c
= smalloc(sizeof(struct ssh_channel
));
5805 c
->remoteid
= -1; /* to be set when open confirmed */
5806 c
->localid
= alloc_channel_id();
5808 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5810 bufchain_init(&c
->v
.v2
.outbuffer
);
5811 add234(ssh_channels
, c
);
5817 * This is called when stdout/stderr (the entity to which
5818 * from_backend sends data) manages to clear some backlog.
5820 void ssh_unthrottle(int bufsize
)
5822 if (ssh_version
== 1) {
5823 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5824 ssh1_stdout_throttling
= 0;
5828 if (mainchan
&& mainchan
->closes
== 0)
5829 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5833 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5835 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5838 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5841 if (ssh_version
== 1) {
5842 send_packet(SSH1_MSG_PORT_OPEN
,
5843 PKT_INT
, c
->localid
,
5846 //PKT_STR, <org:orgport>,
5849 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5850 ssh2_pkt_addstring("direct-tcpip");
5851 ssh2_pkt_adduint32(c
->localid
);
5852 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5853 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5854 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5855 ssh2_pkt_addstring(hostname
);
5856 ssh2_pkt_adduint32(port
);
5858 * We make up values for the originator data; partly it's
5859 * too much hassle to keep track, and partly I'm not
5860 * convinced the server should be told details like that
5861 * about my local network configuration.
5863 ssh2_pkt_addstring("client-side-connection");
5864 ssh2_pkt_adduint32(0);
5870 static Socket
ssh_socket(void)
5875 static int ssh_sendok(void)
5880 static int ssh_ldisc(int option
)
5882 if (option
== LD_ECHO
)
5884 if (option
== LD_EDIT
)
5889 static int ssh_return_exitcode(void)
5891 return ssh_exitcode
;
5894 Backend ssh_backend
= {
5901 ssh_return_exitcode
,