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];
518 int (*ssh_get_line
) (const char *prompt
, char *str
, int maxlen
,
521 static char *savedhost
;
522 static int savedport
;
523 static int ssh_send_ok
;
524 static int ssh_echoing
, ssh_editing
;
526 static tree234
*ssh_channels
; /* indexed by local id */
527 static struct ssh_channel
*mainchan
; /* primary session channel */
528 static int ssh_exitcode
= -1;
530 static tree234
*ssh_rportfwds
;
534 SSH_STATE_BEFORE_SIZE
,
538 } ssh_state
= SSH_STATE_PREPACKET
;
540 static int size_needed
= FALSE
, eof_needed
= FALSE
;
542 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
543 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
544 static unsigned char *deferred_send_data
= NULL
;
545 static int deferred_len
= 0, deferred_size
= 0;
548 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
549 * that fails. This variable is the means by which scp.c can reach
550 * into the SSH code and find out which one it got.
552 int ssh_fallback_cmd
= 0;
554 static int ssh_version
;
555 static int ssh1_throttle_count
;
556 static int ssh_overall_bufsize
;
557 static int ssh_throttled_all
;
558 static int ssh1_stdout_throttling
;
559 static void (*ssh_protocol
) (unsigned char *in
, int inlen
, int ispkt
);
560 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
561 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
562 static void ssh_size(void);
563 static void ssh_special(Telnet_Special
);
564 static int ssh2_try_send(struct ssh_channel
*c
);
565 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
567 static void ssh_throttle_all(int enable
, int bufsize
);
568 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
569 static int (*s_rdpkt
) (unsigned char **data
, int *datalen
);
570 static int ssh_sendbuffer(void);
572 static struct rdpkt1_state_tag
{
573 long len
, pad
, biglen
, to_read
;
574 unsigned long realcrc
, gotcrc
;
580 static struct rdpkt2_state_tag
{
581 long len
, pad
, payload
, packetlen
, maclen
;
584 unsigned long incoming_sequence
;
587 static int ssh_channelcmp(void *av
, void *bv
)
589 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
590 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
591 if (a
->localid
< b
->localid
)
593 if (a
->localid
> b
->localid
)
597 static int ssh_channelfind(void *av
, void *bv
)
599 unsigned *a
= (unsigned *) av
;
600 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
608 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
610 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
611 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
613 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
614 return i
< 0 ?
-1 : +1;
615 if (a
->dport
> b
->dport
)
617 if (a
->dport
< b
->dport
)
622 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
624 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
625 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
627 if (a
->sport
> b
->sport
)
629 if (a
->sport
< b
->sport
)
634 static int alloc_channel_id(void)
636 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
637 unsigned low
, high
, mid
;
639 struct ssh_channel
*c
;
642 * First-fit allocation of channel numbers: always pick the
643 * lowest unused one. To do this, binary-search using the
644 * counted B-tree to find the largest channel ID which is in a
645 * contiguous sequence from the beginning. (Precisely
646 * everything in that sequence must have ID equal to its tree
647 * index plus CHANNEL_NUMBER_OFFSET.)
649 tsize
= count234(ssh_channels
);
653 while (high
- low
> 1) {
654 mid
= (high
+ low
) / 2;
655 c
= index234(ssh_channels
, mid
);
656 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
657 low
= mid
; /* this one is fine */
659 high
= mid
; /* this one is past it */
662 * Now low points to either -1, or the tree index of the
663 * largest ID in the initial sequence.
666 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
667 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
669 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
672 static void c_write(char *buf
, int len
)
674 if ((flags
& FLAG_STDERR
)) {
676 for (i
= 0; i
< len
; i
++)
678 fputc(buf
[i
], stderr
);
681 from_backend(1, buf
, len
);
684 static void c_write_untrusted(char *buf
, int len
)
687 for (i
= 0; i
< len
; i
++) {
690 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
695 static void c_write_str(char *buf
)
697 c_write(buf
, strlen(buf
));
701 * Collect incoming data in the incoming packet buffer.
702 * Decipher and verify the packet when it is completely read.
703 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
704 * Update the *data and *datalen variables.
705 * Return the additional nr of bytes needed, or 0 when
706 * a complete packet is available.
708 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
710 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
719 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
720 while ((*datalen
) == 0)
722 st
->len
= (st
->len
<< 8) + **data
;
723 (*data
)++, (*datalen
)--;
726 st
->pad
= 8 - (st
->len
% 8);
727 st
->biglen
= st
->len
+ st
->pad
;
728 pktin
.length
= st
->len
- 5;
730 if (pktin
.maxlen
< st
->biglen
) {
731 pktin
.maxlen
= st
->biglen
;
732 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
733 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
735 fatalbox("Out of memory");
738 st
->to_read
= st
->biglen
;
740 while (st
->to_read
> 0) {
741 st
->chunk
= st
->to_read
;
742 while ((*datalen
) == 0)
743 crReturn(st
->to_read
);
744 if (st
->chunk
> (*datalen
))
745 st
->chunk
= (*datalen
);
746 memcpy(st
->p
, *data
, st
->chunk
);
748 *datalen
-= st
->chunk
;
750 st
->to_read
-= st
->chunk
;
753 if (cipher
&& detect_attack(pktin
.data
, st
->biglen
, NULL
)) {
754 bombout(("Network attack (CRC compensation) detected!"));
759 cipher
->decrypt(pktin
.data
, st
->biglen
);
761 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
762 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
763 if (st
->gotcrc
!= st
->realcrc
) {
764 bombout(("Incorrect CRC received on packet"));
768 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
770 if (ssh1_compressing
) {
771 unsigned char *decompblk
;
773 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
774 &decompblk
, &decomplen
);
776 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
777 pktin
.maxlen
= st
->pad
+ decomplen
;
778 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
779 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
781 fatalbox("Out of memory");
784 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
786 pktin
.length
= decomplen
- 1;
789 pktin
.type
= pktin
.body
[-1];
791 log_packet(PKT_INCOMING
, pktin
.type
, ssh1_pkt_type(pktin
.type
),
792 pktin
.body
, pktin
.length
);
794 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
795 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
796 pktin
.type
== SSH1_MSG_DEBUG
||
797 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
798 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
799 long stringlen
= GET_32BIT(pktin
.body
);
800 if (stringlen
+ 4 != pktin
.length
) {
801 bombout(("Received data packet with bogus string length"));
806 if (pktin
.type
== SSH1_MSG_DEBUG
) {
807 /* log debug message */
809 int stringlen
= GET_32BIT(pktin
.body
);
810 strcpy(buf
, "Remote: ");
813 memcpy(buf
+ 8, pktin
.body
+ 4, stringlen
);
814 buf
[8 + stringlen
] = '\0';
817 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
822 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
823 /* log reason code in disconnect message */
825 unsigned msglen
= GET_32BIT(pktin
.body
);
827 strcpy(buf
, "Remote sent disconnect: ");
828 nowlen
= strlen(buf
);
829 if (msglen
> sizeof(buf
) - nowlen
- 1)
830 msglen
= sizeof(buf
) - nowlen
- 1;
831 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
832 buf
[nowlen
+ msglen
] = '\0';
833 /* logevent(buf); (this is now done within the bombout macro) */
834 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
841 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
843 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
851 st
->cipherblk
= sccipher
->blksize
;
854 if (st
->cipherblk
< 8)
857 if (pktin
.maxlen
< st
->cipherblk
) {
858 pktin
.maxlen
= st
->cipherblk
;
861 NULL ?
smalloc(st
->cipherblk
+
862 APIEXTRA
) : srealloc(pktin
.data
,
866 fatalbox("Out of memory");
870 * Acquire and decrypt the first block of the packet. This will
871 * contain the length and padding details.
873 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
874 while ((*datalen
) == 0)
875 crReturn(st
->cipherblk
- st
->i
);
876 pktin
.data
[st
->i
] = *(*data
)++;
881 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
884 * Now get the length and padding figures.
886 st
->len
= GET_32BIT(pktin
.data
);
887 st
->pad
= pktin
.data
[4];
890 * This enables us to deduce the payload length.
892 st
->payload
= st
->len
- st
->pad
- 1;
894 pktin
.length
= st
->payload
+ 5;
897 * So now we can work out the total packet length.
899 st
->packetlen
= st
->len
+ 4;
900 st
->maclen
= scmac ? scmac
->len
: 0;
903 * Adjust memory allocation if packet is too big.
905 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
906 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
909 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
914 fatalbox("Out of memory");
918 * Read and decrypt the remainder of the packet.
920 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
922 while ((*datalen
) == 0)
923 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
924 pktin
.data
[st
->i
] = *(*data
)++;
927 /* Decrypt everything _except_ the MAC. */
929 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
930 st
->packetlen
- st
->cipherblk
);
936 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
937 st
->incoming_sequence
)) {
938 bombout(("Incorrect MAC received on packet"));
941 st
->incoming_sequence
++; /* whether or not we MACed */
944 * Decompress packet payload.
947 unsigned char *newpayload
;
949 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
950 &newpayload
, &newlen
)) {
951 if (pktin
.maxlen
< newlen
+ 5) {
952 pktin
.maxlen
= newlen
+ 5;
955 NULL ?
smalloc(pktin
.maxlen
+
956 APIEXTRA
) : srealloc(pktin
.data
,
960 fatalbox("Out of memory");
962 pktin
.length
= 5 + newlen
;
963 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
969 pktin
.type
= pktin
.data
[5];
971 log_packet(PKT_INCOMING
, pktin
.type
, ssh2_pkt_type(pktin
.type
),
972 pktin
.data
+6, pktin
.length
-6);
974 switch (pktin
.type
) {
976 * These packets we must handle instantly.
978 case SSH2_MSG_DISCONNECT
:
980 /* log reason code in disconnect message */
982 int reason
= GET_32BIT(pktin
.data
+ 6);
983 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
985 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
986 sprintf(buf
, "Received disconnect message (%s)",
987 ssh2_disconnect_reasons
[reason
]);
989 sprintf(buf
, "Received disconnect message (unknown type %d)",
993 strcpy(buf
, "Disconnection message text: ");
994 nowlen
= strlen(buf
);
995 if (msglen
> sizeof(buf
) - nowlen
- 1)
996 msglen
= sizeof(buf
) - nowlen
- 1;
997 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
998 buf
[nowlen
+ msglen
] = '\0';
1000 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1002 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1003 ssh2_disconnect_reasons
[reason
] : "unknown",
1008 case SSH2_MSG_IGNORE
:
1010 case SSH2_MSG_DEBUG
:
1012 /* log the debug message */
1014 /* int display = pktin.body[6]; */
1015 int stringlen
= GET_32BIT(pktin
.data
+7);
1017 strcpy(buf
, "Remote debug message: ");
1018 prefix
= strlen(buf
);
1019 if (stringlen
> sizeof(buf
)-prefix
-1)
1020 stringlen
= sizeof(buf
)-prefix
-1;
1021 memcpy(buf
+ prefix
, pktin
.data
+ 11, stringlen
);
1022 buf
[prefix
+ stringlen
] = '\0';
1025 goto next_packet
; /* FIXME: print the debug message */
1028 * These packets we need do nothing about here.
1030 case SSH2_MSG_UNIMPLEMENTED
:
1031 case SSH2_MSG_SERVICE_REQUEST
:
1032 case SSH2_MSG_SERVICE_ACCEPT
:
1033 case SSH2_MSG_KEXINIT
:
1034 case SSH2_MSG_NEWKEYS
:
1035 case SSH2_MSG_KEXDH_INIT
:
1036 case SSH2_MSG_KEXDH_REPLY
:
1037 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1038 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1039 case SSH2_MSG_KEX_DH_GEX_INIT
:
1040 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1041 case SSH2_MSG_USERAUTH_REQUEST
:
1042 case SSH2_MSG_USERAUTH_FAILURE
:
1043 case SSH2_MSG_USERAUTH_SUCCESS
:
1044 case SSH2_MSG_USERAUTH_BANNER
:
1045 case SSH2_MSG_USERAUTH_PK_OK
:
1046 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1047 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1048 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1049 case SSH2_MSG_GLOBAL_REQUEST
:
1050 case SSH2_MSG_REQUEST_SUCCESS
:
1051 case SSH2_MSG_REQUEST_FAILURE
:
1052 case SSH2_MSG_CHANNEL_OPEN
:
1053 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1054 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1055 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1056 case SSH2_MSG_CHANNEL_DATA
:
1057 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1058 case SSH2_MSG_CHANNEL_EOF
:
1059 case SSH2_MSG_CHANNEL_CLOSE
:
1060 case SSH2_MSG_CHANNEL_REQUEST
:
1061 case SSH2_MSG_CHANNEL_SUCCESS
:
1062 case SSH2_MSG_CHANNEL_FAILURE
:
1066 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1069 ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED
);
1070 ssh2_pkt_adduint32(st
->incoming_sequence
- 1);
1078 static void ssh1_pktout_size(int len
)
1082 len
+= 5; /* type and CRC */
1083 pad
= 8 - (len
% 8);
1086 pktout
.length
= len
- 5;
1087 if (pktout
.maxlen
< biglen
) {
1088 pktout
.maxlen
= biglen
;
1090 /* Allocate enough buffer space for extra block
1091 * for MS CryptEncrypt() */
1092 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
1093 srealloc(pktout
.data
, biglen
+ 12));
1095 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
1096 srealloc(pktout
.data
, biglen
+ 4));
1099 fatalbox("Out of memory");
1101 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
1104 static void s_wrpkt_start(int type
, int len
)
1106 ssh1_pktout_size(len
);
1110 static int s_wrpkt_prepare(void)
1112 int pad
, len
, biglen
, i
;
1115 pktout
.body
[-1] = pktout
.type
;
1117 log_packet(PKT_OUTGOING
, pktout
.type
, ssh1_pkt_type(pktout
.type
),
1118 pktout
.body
, pktout
.length
);
1120 if (ssh1_compressing
) {
1121 unsigned char *compblk
;
1123 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
1124 &compblk
, &complen
);
1125 ssh1_pktout_size(complen
- 1);
1126 memcpy(pktout
.body
- 1, compblk
, complen
);
1130 len
= pktout
.length
+ 5; /* type and CRC */
1131 pad
= 8 - (len
% 8);
1134 for (i
= 0; i
< pad
; i
++)
1135 pktout
.data
[i
+ 4] = random_byte();
1136 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
1137 PUT_32BIT(pktout
.data
+ biglen
, crc
);
1138 PUT_32BIT(pktout
.data
, len
);
1141 cipher
->encrypt(pktout
.data
+ 4, biglen
);
1146 static void s_wrpkt(void)
1149 len
= s_wrpkt_prepare();
1150 backlog
= sk_write(s
, pktout
.data
, len
);
1151 if (backlog
> SSH_MAX_BACKLOG
)
1152 ssh_throttle_all(1, backlog
);
1155 static void s_wrpkt_defer(void)
1158 len
= s_wrpkt_prepare();
1159 if (deferred_len
+ len
> deferred_size
) {
1160 deferred_size
= deferred_len
+ len
+ 128;
1161 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1163 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1164 deferred_len
+= len
;
1168 * Construct a packet with the specified contents.
1170 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1172 unsigned char *p
, *argp
, argchar
;
1173 unsigned long argint
;
1174 int pktlen
, argtype
, arglen
;
1178 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1181 (void) va_arg(ap1
, int);
1185 (void) va_arg(ap1
, char);
1189 (void) va_arg(ap1
, unsigned char *);
1190 arglen
= va_arg(ap1
, int);
1194 argp
= va_arg(ap1
, unsigned char *);
1195 arglen
= strlen(argp
);
1196 pktlen
+= 4 + arglen
;
1199 bn
= va_arg(ap1
, Bignum
);
1200 pktlen
+= ssh1_bignum_length(bn
);
1207 s_wrpkt_start(pkttype
, pktlen
);
1210 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1213 argint
= va_arg(ap2
, int);
1214 PUT_32BIT(p
, argint
);
1218 argchar
= va_arg(ap2
, unsigned char);
1223 argp
= va_arg(ap2
, unsigned char *);
1224 arglen
= va_arg(ap2
, int);
1225 memcpy(p
, argp
, arglen
);
1229 argp
= va_arg(ap2
, unsigned char *);
1230 arglen
= strlen(argp
);
1231 PUT_32BIT(p
, arglen
);
1232 memcpy(p
+ 4, argp
, arglen
);
1236 bn
= va_arg(ap2
, Bignum
);
1237 p
+= ssh1_write_bignum(p
, bn
);
1243 static void send_packet(int pkttype
, ...)
1246 va_start(ap1
, pkttype
);
1247 va_start(ap2
, pkttype
);
1248 construct_packet(pkttype
, ap1
, ap2
);
1252 static void defer_packet(int pkttype
, ...)
1255 va_start(ap1
, pkttype
);
1256 va_start(ap2
, pkttype
);
1257 construct_packet(pkttype
, ap1
, ap2
);
1261 static int ssh_versioncmp(char *a
, char *b
)
1264 unsigned long av
, bv
;
1266 av
= strtoul(a
, &ae
, 10);
1267 bv
= strtoul(b
, &be
, 10);
1269 return (av
< bv ?
-1 : +1);
1274 av
= strtoul(ae
, &ae
, 10);
1275 bv
= strtoul(be
, &be
, 10);
1277 return (av
< bv ?
-1 : +1);
1283 * Utility routines for putting an SSH-protocol `string' and
1284 * `uint32' into a SHA state.
1287 static void sha_string(SHA_State
* s
, void *str
, int len
)
1289 unsigned char lenblk
[4];
1290 PUT_32BIT(lenblk
, len
);
1291 SHA_Bytes(s
, lenblk
, 4);
1292 SHA_Bytes(s
, str
, len
);
1295 static void sha_uint32(SHA_State
* s
, unsigned i
)
1297 unsigned char intblk
[4];
1298 PUT_32BIT(intblk
, i
);
1299 SHA_Bytes(s
, intblk
, 4);
1303 * SSH2 packet construction functions.
1305 static void ssh2_pkt_ensure(int length
)
1307 if (pktout
.maxlen
< length
) {
1308 pktout
.maxlen
= length
+ 256;
1311 NULL ?
smalloc(pktout
.maxlen
+
1312 APIEXTRA
) : srealloc(pktout
.data
,
1316 fatalbox("Out of memory");
1319 static void ssh2_pkt_adddata(void *data
, int len
)
1321 pktout
.length
+= len
;
1322 ssh2_pkt_ensure(pktout
.length
);
1323 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1325 static void ssh2_pkt_addbyte(unsigned char byte
)
1327 ssh2_pkt_adddata(&byte
, 1);
1329 static void ssh2_pkt_init(int pkt_type
)
1332 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1334 static void ssh2_pkt_addbool(unsigned char value
)
1336 ssh2_pkt_adddata(&value
, 1);
1338 static void ssh2_pkt_adduint32(unsigned long value
)
1341 PUT_32BIT(x
, value
);
1342 ssh2_pkt_adddata(x
, 4);
1344 static void ssh2_pkt_addstring_start(void)
1346 ssh2_pkt_adduint32(0);
1347 pktout
.savedpos
= pktout
.length
;
1349 static void ssh2_pkt_addstring_str(char *data
)
1351 ssh2_pkt_adddata(data
, strlen(data
));
1352 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1353 pktout
.length
- pktout
.savedpos
);
1355 static void ssh2_pkt_addstring_data(char *data
, int len
)
1357 ssh2_pkt_adddata(data
, len
);
1358 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1359 pktout
.length
- pktout
.savedpos
);
1361 static void ssh2_pkt_addstring(char *data
)
1363 ssh2_pkt_addstring_start();
1364 ssh2_pkt_addstring_str(data
);
1366 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1369 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1372 fatalbox("out of memory");
1374 for (i
= 1; i
<= n
; i
++)
1375 p
[i
] = bignum_byte(b
, n
- i
);
1377 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1379 memmove(p
, p
+ i
, n
+ 1 - i
);
1383 static void ssh2_pkt_addmp(Bignum b
)
1387 p
= ssh2_mpint_fmt(b
, &len
);
1388 ssh2_pkt_addstring_start();
1389 ssh2_pkt_addstring_data(p
, len
);
1394 * Construct an SSH2 final-form packet: compress it, encrypt it,
1395 * put the MAC on it. Final packet, ready to be sent, is stored in
1396 * pktout.data. Total length is returned.
1398 static int ssh2_pkt_construct(void)
1400 int cipherblk
, maclen
, padding
, i
;
1401 static unsigned long outgoing_sequence
= 0;
1403 log_packet(PKT_OUTGOING
, pktout
.data
[5], ssh2_pkt_type(pktout
.data
[5]),
1404 pktout
.data
+ 6, pktout
.length
- 6);
1407 * Compress packet payload.
1410 unsigned char *newpayload
;
1412 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1413 &newpayload
, &newlen
)) {
1415 ssh2_pkt_adddata(newpayload
, newlen
);
1421 * Add padding. At least four bytes, and must also bring total
1422 * length (minus MAC) up to a multiple of the block size.
1424 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1425 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1428 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1429 maclen
= csmac ? csmac
->len
: 0;
1430 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1431 pktout
.data
[4] = padding
;
1432 for (i
= 0; i
< padding
; i
++)
1433 pktout
.data
[pktout
.length
+ i
] = random_byte();
1434 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1436 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1438 outgoing_sequence
++; /* whether or not we MACed */
1441 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1443 /* Ready-to-send packet starts at pktout.data. We return length. */
1444 return pktout
.length
+ padding
+ maclen
;
1448 * Construct and send an SSH2 packet immediately.
1450 static void ssh2_pkt_send(void)
1454 len
= ssh2_pkt_construct();
1455 backlog
= sk_write(s
, pktout
.data
, len
);
1456 if (backlog
> SSH_MAX_BACKLOG
)
1457 ssh_throttle_all(1, backlog
);
1461 * Construct an SSH2 packet and add it to a deferred data block.
1462 * Useful for sending multiple packets in a single sk_write() call,
1463 * to prevent a traffic-analysing listener from being able to work
1464 * out the length of any particular packet (such as the password
1467 * Note that because SSH2 sequence-numbers its packets, this can
1468 * NOT be used as an m4-style `defer' allowing packets to be
1469 * constructed in one order and sent in another.
1471 static void ssh2_pkt_defer(void)
1473 int len
= ssh2_pkt_construct();
1474 if (deferred_len
+ len
> deferred_size
) {
1475 deferred_size
= deferred_len
+ len
+ 128;
1476 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1478 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1479 deferred_len
+= len
;
1483 * Send the whole deferred data block constructed by
1484 * ssh2_pkt_defer() or SSH1's defer_packet().
1486 static void ssh_pkt_defersend(void)
1489 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1490 deferred_len
= deferred_size
= 0;
1491 sfree(deferred_send_data
);
1492 deferred_send_data
= NULL
;
1493 if (backlog
> SSH_MAX_BACKLOG
)
1494 ssh_throttle_all(1, backlog
);
1498 void bndebug(char *string
, Bignum b
)
1502 p
= ssh2_mpint_fmt(b
, &len
);
1503 debug(("%s", string
));
1504 for (i
= 0; i
< len
; i
++)
1505 debug((" %02x", p
[i
]));
1511 static void sha_mpint(SHA_State
* s
, Bignum b
)
1515 p
= ssh2_mpint_fmt(b
, &len
);
1516 sha_string(s
, p
, len
);
1521 * SSH2 packet decode functions.
1523 static unsigned long ssh2_pkt_getuint32(void)
1525 unsigned long value
;
1526 if (pktin
.length
- pktin
.savedpos
< 4)
1527 return 0; /* arrgh, no way to decline (FIXME?) */
1528 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1529 pktin
.savedpos
+= 4;
1532 static int ssh2_pkt_getbool(void)
1534 unsigned long value
;
1535 if (pktin
.length
- pktin
.savedpos
< 1)
1536 return 0; /* arrgh, no way to decline (FIXME?) */
1537 value
= pktin
.data
[pktin
.savedpos
] != 0;
1541 static void ssh2_pkt_getstring(char **p
, int *length
)
1544 if (pktin
.length
- pktin
.savedpos
< 4)
1546 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1547 pktin
.savedpos
+= 4;
1548 if (pktin
.length
- pktin
.savedpos
< *length
)
1550 *p
= pktin
.data
+ pktin
.savedpos
;
1551 pktin
.savedpos
+= *length
;
1553 static Bignum
ssh2_pkt_getmp(void)
1559 ssh2_pkt_getstring(&p
, &length
);
1563 bombout(("internal error: Can't handle negative mpints"));
1566 b
= bignum_from_bytes(p
, length
);
1571 * Helper function to add an SSH2 signature blob to a packet.
1572 * Expects to be shown the public key blob as well as the signature
1573 * blob. Normally works just like ssh2_pkt_addstring, but will
1574 * fiddle with the signature packet if necessary for
1575 * BUG_SSH2_RSA_PADDING.
1577 static void ssh2_add_sigblob(void *pkblob_v
, int pkblob_len
,
1578 void *sigblob_v
, int sigblob_len
)
1580 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1581 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1583 /* dmemdump(pkblob, pkblob_len); */
1584 /* dmemdump(sigblob, sigblob_len); */
1587 * See if this is in fact an ssh-rsa signature and a buggy
1588 * server; otherwise we can just do this the easy way.
1590 if ((ssh_remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1591 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1592 int pos
, len
, siglen
;
1595 * Find the byte length of the modulus.
1598 pos
= 4+7; /* skip over "ssh-rsa" */
1599 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1600 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1601 pos
+= 4; /* find modulus itself */
1602 while (len
> 0 && pkblob
[pos
] == 0)
1604 /* debug(("modulus length is %d\n", len)); */
1607 * Now find the signature integer.
1609 pos
= 4+7; /* skip over "ssh-rsa" */
1610 siglen
= GET_32BIT(sigblob
+pos
);
1611 /* debug(("signature length is %d\n", siglen)); */
1613 if (len
!= siglen
) {
1614 unsigned char newlen
[4];
1615 ssh2_pkt_addstring_start();
1616 ssh2_pkt_addstring_data(sigblob
, pos
);
1617 /* dmemdump(sigblob, pos); */
1618 pos
+= 4; /* point to start of actual sig */
1619 PUT_32BIT(newlen
, len
);
1620 ssh2_pkt_addstring_data(newlen
, 4);
1621 /* dmemdump(newlen, 4); */
1623 while (len
-- > siglen
) {
1624 ssh2_pkt_addstring_data(newlen
, 1);
1625 /* dmemdump(newlen, 1); */
1627 ssh2_pkt_addstring_data(sigblob
+pos
, siglen
);
1628 /* dmemdump(sigblob+pos, siglen); */
1632 /* Otherwise fall through and do it the easy way. */
1635 ssh2_pkt_addstring_start();
1636 ssh2_pkt_addstring_data(sigblob
, sigblob_len
);
1640 * Examine the remote side's version string and compare it against
1641 * a list of known buggy implementations.
1643 static void ssh_detect_bugs(char *vstring
)
1645 char *imp
; /* pointer to implementation part */
1647 imp
+= strcspn(imp
, "-");
1649 imp
+= strcspn(imp
, "-");
1652 ssh_remote_bugs
= 0;
1654 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1655 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1656 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1658 * These versions don't support SSH1_MSG_IGNORE, so we have
1659 * to use a different defence against password length
1662 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1663 logevent("We believe remote version has SSH1 ignore bug");
1666 if (!strcmp(imp
, "Cisco-1.25")) {
1668 * These versions need a plain password sent; they can't
1669 * handle having a null and a random length of data after
1672 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1673 logevent("We believe remote version needs a plain SSH1 password");
1676 if (!strcmp(imp
, "Cisco-1.25")) {
1678 * These versions apparently have no clue whatever about
1679 * RSA authentication and will panic and die if they see
1680 * an AUTH_RSA message.
1682 ssh_remote_bugs
|= BUG_CHOKES_ON_RSA
;
1683 logevent("We believe remote version can't handle RSA authentication");
1686 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1687 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1688 !strncmp(imp
, "2.1 ", 4)) {
1690 * These versions have the HMAC bug.
1692 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1693 logevent("We believe remote version has SSH2 HMAC bug");
1696 if ((!strncmp(imp
, "OpenSSH_2.", 10) && imp
[10]>='5' && imp
[10]<='9') ||
1697 (!strncmp(imp
, "OpenSSH_3.", 10) && imp
[10]>='0' && imp
[10]<='2')) {
1699 * These versions have the SSH2 RSA padding bug.
1701 ssh_remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1702 logevent("We believe remote version has SSH2 RSA padding bug");
1706 static int do_ssh_init(unsigned char c
)
1709 static char version
[10];
1710 static char *vstring
;
1711 static int vstrsize
;
1717 /* Search for the string "SSH-" in the input. */
1720 static const int transS
[] = { 1, 2, 2, 1 };
1721 static const int transH
[] = { 0, 0, 3, 0 };
1722 static const int transminus
[] = { 0, 0, 0, -1 };
1733 crReturn(1); /* get another character */
1737 vstring
= smalloc(vstrsize
);
1738 strcpy(vstring
, "SSH-");
1742 crReturn(1); /* get another char */
1743 if (vslen
>= vstrsize
- 1) {
1745 vstring
= srealloc(vstring
, vstrsize
);
1747 vstring
[vslen
++] = c
;
1752 } else if (i
< sizeof(version
) - 1)
1754 } else if (c
== '\n')
1758 ssh_agentfwd_enabled
= FALSE
;
1759 rdpkt2_state
.incoming_sequence
= 0;
1762 vlog
= smalloc(20 + vslen
);
1763 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1764 sprintf(vlog
, "Server version: %s", vstring
);
1766 ssh_detect_bugs(vstring
);
1770 * Server version "1.99" means we can choose whether we use v1
1771 * or v2 protocol. Choice is based on cfg.sshprot.
1773 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1775 * This is a v2 server. Begin v2 protocol.
1777 char verstring
[80], vlog
[100];
1778 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1779 SHA_Init(&exhashbase
);
1781 * Hash our version string and their version string.
1783 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1784 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1785 sprintf(vlog
, "We claim version: %s", verstring
);
1787 strcat(verstring
, "\n");
1788 logevent("Using SSH protocol version 2");
1789 sk_write(s
, verstring
, strlen(verstring
));
1790 ssh_protocol
= ssh2_protocol
;
1792 s_rdpkt
= ssh2_rdpkt
;
1795 * This is a v1 server. Begin v1 protocol.
1797 char verstring
[80], vlog
[100];
1798 sprintf(verstring
, "SSH-%s-%s",
1799 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1801 sprintf(vlog
, "We claim version: %s", verstring
);
1803 strcat(verstring
, "\n");
1805 if (cfg
.sshprot
== 3) {
1806 bombout(("SSH protocol version 2 required by user but not provided by server"));
1810 logevent("Using SSH protocol version 1");
1811 sk_write(s
, verstring
, strlen(verstring
));
1812 ssh_protocol
= ssh1_protocol
;
1814 s_rdpkt
= ssh1_rdpkt
;
1816 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1823 static void ssh_gotdata(unsigned char *data
, int datalen
)
1828 * To begin with, feed the characters one by one to the
1829 * protocol initialisation / selection function do_ssh_init().
1830 * When that returns 0, we're done with the initial greeting
1831 * exchange and can move on to packet discipline.
1836 crReturnV
; /* more data please */
1837 ret
= do_ssh_init(*data
);
1845 * We emerge from that loop when the initial negotiation is
1846 * over and we have selected an s_rdpkt function. Now pass
1847 * everything to s_rdpkt, and then pass the resulting packets
1848 * to the proper protocol handler.
1853 while (datalen
> 0) {
1854 if (s_rdpkt(&data
, &datalen
) == 0) {
1855 if (ssh_state
== SSH_STATE_CLOSED
) {
1858 ssh_protocol(NULL
, 0, 1);
1859 if (ssh_state
== SSH_STATE_CLOSED
) {
1869 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1872 ssh_state
= SSH_STATE_CLOSED
;
1878 /* A socket error has occurred. */
1879 logevent(error_msg
);
1880 connection_fatal(error_msg
);
1882 /* Otherwise, the remote side closed the connection normally. */
1887 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1889 ssh_gotdata(data
, len
);
1890 if (ssh_state
== SSH_STATE_CLOSED
) {
1900 static void ssh_sent(Plug plug
, int bufsize
)
1903 * If the send backlog on the SSH socket itself clears, we
1904 * should unthrottle the whole world if it was throttled.
1906 if (bufsize
< SSH_MAX_BACKLOG
)
1907 ssh_throttle_all(0, bufsize
);
1911 * Connect to specified host and port.
1912 * Returns an error message, or NULL on success.
1913 * Also places the canonical host name into `realhost'. It must be
1914 * freed by the caller.
1916 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1918 static struct plug_function_table fn_table
= {
1923 }, *fn_table_ptr
= &fn_table
;
1932 savedhost
= smalloc(1 + strlen(host
));
1934 fatalbox("Out of memory");
1935 strcpy(savedhost
, host
);
1938 port
= 22; /* default ssh port */
1953 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1956 addr
= sk_namelookup(host
, realhost
);
1957 if ((err
= sk_addr_error(addr
)))
1961 *realhost
= strdup(FWhost
);
1968 char buf
[200], addrbuf
[100];
1969 sk_getaddr(addr
, addrbuf
, 100);
1970 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1973 s
= new_connection(addr
, *realhost
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1974 if ((err
= sk_socket_error(s
))) {
1980 sk_write(s
, "connect ", 8);
1981 sk_write(s
, FWhost
, strlen(FWhost
));
1984 sprintf(buf
, " %d\n", FWport
);
1985 sk_write(s
, buf
, strlen(buf
));
1993 * Throttle or unthrottle the SSH connection.
1995 static void ssh1_throttle(int adjust
)
1997 int old_count
= ssh1_throttle_count
;
1998 ssh1_throttle_count
+= adjust
;
1999 assert(ssh1_throttle_count
>= 0);
2000 if (ssh1_throttle_count
&& !old_count
) {
2001 sk_set_frozen(s
, 1);
2002 } else if (!ssh1_throttle_count
&& old_count
) {
2003 sk_set_frozen(s
, 0);
2008 * Throttle or unthrottle _all_ local data streams (for when sends
2009 * on the SSH connection itself back up).
2011 static void ssh_throttle_all(int enable
, int bufsize
)
2014 struct ssh_channel
*c
;
2016 if (enable
== ssh_throttled_all
)
2018 ssh_throttled_all
= enable
;
2019 ssh_overall_bufsize
= bufsize
;
2022 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
2024 case CHAN_MAINSESSION
:
2026 * This is treated separately, outside the switch.
2030 x11_override_throttle(c
->u
.x11
.s
, enable
);
2033 /* Agent channels require no buffer management. */
2036 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2043 * Handle the key exchange and user authentication phases.
2045 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
2049 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
2050 unsigned char cookie
[8];
2051 struct RSAKey servkey
, hostkey
;
2052 struct MD5Context md5c
;
2053 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
2054 static int tried_publickey
, tried_agent
;
2055 static int tis_auth_refused
, ccard_auth_refused
;
2056 static unsigned char session_id
[16];
2057 static int cipher_type
;
2058 static char username
[100];
2059 static void *publickey_blob
;
2060 int publickey_bloblen
;
2067 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2068 bombout(("Public key packet not received"));
2072 logevent("Received public keys");
2074 memcpy(cookie
, pktin
.body
, 8);
2076 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
2077 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
2080 * Log the host key fingerprint.
2084 logevent("Host key fingerprint is:");
2085 strcpy(logmsg
, " ");
2086 hostkey
.comment
= NULL
;
2087 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2088 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2092 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
2093 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
2094 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
2096 ssh1_local_protoflags
=
2097 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2098 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2101 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
2102 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
2103 MD5Update(&md5c
, pktin
.body
, 8);
2104 MD5Final(session_id
, &md5c
);
2106 for (i
= 0; i
< 32; i
++)
2107 session_key
[i
] = random_byte();
2109 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2111 rsabuf
= smalloc(len
);
2113 fatalbox("Out of memory");
2116 * Verify the host key.
2120 * First format the key into a string.
2122 int len
= rsastr_len(&hostkey
);
2123 char fingerprint
[100];
2124 char *keystr
= smalloc(len
);
2126 fatalbox("Out of memory");
2127 rsastr_fmt(keystr
, &hostkey
);
2128 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2129 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
2134 for (i
= 0; i
< 32; i
++) {
2135 rsabuf
[i
] = session_key
[i
];
2137 rsabuf
[i
] ^= session_id
[i
];
2140 if (hostkey
.bytes
> servkey
.bytes
) {
2141 rsaencrypt(rsabuf
, 32, &servkey
);
2142 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
2144 rsaencrypt(rsabuf
, 32, &hostkey
);
2145 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
2148 logevent("Encrypted session key");
2151 int cipher_chosen
= 0, warn
= 0;
2152 char *cipher_string
= NULL
;
2153 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2154 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2155 if (next_cipher
== CIPHER_WARN
) {
2156 /* If/when we choose a cipher, warn about it */
2158 } else if (next_cipher
== CIPHER_AES
) {
2159 /* XXX Probably don't need to mention this. */
2160 logevent("AES not supported in SSH1, skipping");
2162 switch (next_cipher
) {
2163 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
2164 cipher_string
= "3DES"; break;
2165 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
2166 cipher_string
= "Blowfish"; break;
2167 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
2168 cipher_string
= "single-DES"; break;
2170 if (supported_ciphers_mask
& (1 << cipher_type
))
2174 if (!cipher_chosen
) {
2175 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2176 bombout(("Server violates SSH 1 protocol by not "
2177 "supporting 3DES encryption"));
2179 /* shouldn't happen */
2180 bombout(("No supported ciphers found"));
2184 /* Warn about chosen cipher if necessary. */
2186 askcipher(cipher_string
, 0);
2189 switch (cipher_type
) {
2190 case SSH_CIPHER_3DES
:
2191 logevent("Using 3DES encryption");
2193 case SSH_CIPHER_DES
:
2194 logevent("Using single-DES encryption");
2196 case SSH_CIPHER_BLOWFISH
:
2197 logevent("Using Blowfish encryption");
2201 send_packet(SSH1_CMSG_SESSION_KEY
,
2202 PKT_CHAR
, cipher_type
,
2203 PKT_DATA
, cookie
, 8,
2204 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
2205 PKT_DATA
, rsabuf
, len
,
2206 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
2208 logevent("Trying to enable encryption...");
2212 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2213 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
2214 cipher
->sesskey(session_key
);
2218 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2219 bombout(("Encryption not successfully enabled"));
2223 logevent("Successfully started encryption");
2229 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2231 if (!ssh_get_line("login as: ",
2232 username
, sizeof(username
), FALSE
)) {
2234 * get_line failed to get a username.
2237 logevent("No username provided. Abandoning session.");
2238 ssh_state
= SSH_STATE_CLOSED
;
2242 c_write_str("login as: ");
2245 crWaitUntil(!ispkt
);
2247 switch (c
= *in
++) {
2256 c_write_str("\b \b");
2263 c_write_str("\b \b");
2272 if (((c
>= ' ' && c
<= '~') ||
2273 ((unsigned char) c
>= 160))
2274 && pos
< sizeof(username
)-1) {
2275 username
[pos
++] = c
;
2281 c_write_str("\r\n");
2282 username
[strcspn(username
, "\n\r")] = '\0';
2285 strncpy(username
, cfg
.username
, 99);
2286 username
[99] = '\0';
2289 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2291 char userlog
[22 + sizeof(username
)];
2292 sprintf(userlog
, "Sent username \"%s\"", username
);
2294 if (flags
& FLAG_INTERACTIVE
&&
2295 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2296 strcat(userlog
, "\r\n");
2297 c_write_str(userlog
);
2304 if ((ssh_remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2305 /* We must not attempt PK auth. Pretend we've already tried it. */
2306 tried_publickey
= tried_agent
= 1;
2308 tried_publickey
= tried_agent
= 0;
2310 tis_auth_refused
= ccard_auth_refused
= 0;
2311 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2313 if (!rsakey_pubblob(cfg
.keyfile
, &publickey_blob
, &publickey_bloblen
))
2314 publickey_blob
= NULL
;
2316 publickey_blob
= NULL
;
2318 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2319 static char password
[100];
2320 static char prompt
[200];
2323 static int pwpkt_type
;
2324 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2326 if (agent_exists() && !tried_agent
) {
2328 * Attempt RSA authentication using Pageant.
2330 static unsigned char request
[5], *response
, *p
;
2331 static int responselen
;
2332 static int i
, nkeys
;
2333 static int authed
= FALSE
;
2337 logevent("Pageant is running. Requesting keys.");
2339 /* Request the keys held by the agent. */
2340 PUT_32BIT(request
, 1);
2341 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2342 agent_query(request
, 5, &r
, &responselen
);
2343 response
= (unsigned char *) r
;
2344 if (response
&& responselen
>= 5 &&
2345 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2347 nkeys
= GET_32BIT(p
);
2351 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2354 for (i
= 0; i
< nkeys
; i
++) {
2355 static struct RSAKey key
;
2356 static Bignum challenge
;
2357 static char *commentp
;
2358 static int commentlen
;
2362 sprintf(buf
, "Trying Pageant key #%d", i
);
2365 if (publickey_blob
&&
2366 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
2367 logevent("This key matches configured key file");
2368 tried_publickey
= 1;
2371 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2372 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2373 commentlen
= GET_32BIT(p
);
2377 send_packet(SSH1_CMSG_AUTH_RSA
,
2378 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2380 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2381 logevent("Key refused");
2384 logevent("Received RSA challenge");
2385 ssh1_read_bignum(pktin
.body
, &challenge
);
2387 char *agentreq
, *q
, *ret
;
2390 len
= 1 + 4; /* message type, bit count */
2391 len
+= ssh1_bignum_length(key
.exponent
);
2392 len
+= ssh1_bignum_length(key
.modulus
);
2393 len
+= ssh1_bignum_length(challenge
);
2394 len
+= 16; /* session id */
2395 len
+= 4; /* response format */
2396 agentreq
= smalloc(4 + len
);
2397 PUT_32BIT(agentreq
, len
);
2399 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2400 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2402 q
+= ssh1_write_bignum(q
, key
.exponent
);
2403 q
+= ssh1_write_bignum(q
, key
.modulus
);
2404 q
+= ssh1_write_bignum(q
, challenge
);
2405 memcpy(q
, session_id
, 16);
2407 PUT_32BIT(q
, 1); /* response format */
2408 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2412 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2413 logevent("Sending Pageant's response");
2414 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2415 PKT_DATA
, ret
+ 5, 16,
2419 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2421 ("Pageant's response accepted");
2422 if (flags
& FLAG_VERBOSE
) {
2424 ("Authenticated using RSA key \"");
2425 c_write(commentp
, commentlen
);
2426 c_write_str("\" from agent\r\n");
2431 ("Pageant's response not accepted");
2434 ("Pageant failed to answer challenge");
2438 logevent("No reply received from Pageant");
2441 freebn(key
.exponent
);
2442 freebn(key
.modulus
);
2451 if (*cfg
.keyfile
&& !tried_publickey
)
2452 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2454 if (cfg
.try_tis_auth
&&
2455 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2456 !tis_auth_refused
) {
2457 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2458 logevent("Requested TIS authentication");
2459 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2461 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2462 logevent("TIS authentication declined");
2463 if (flags
& FLAG_INTERACTIVE
)
2464 c_write_str("TIS authentication refused.\r\n");
2465 tis_auth_refused
= 1;
2468 int challengelen
= ((pktin
.body
[0] << 24) |
2469 (pktin
.body
[1] << 16) |
2470 (pktin
.body
[2] << 8) |
2472 logevent("Received TIS challenge");
2473 if (challengelen
> sizeof(prompt
) - 1)
2474 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2475 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2476 /* Prompt heuristic comes from OpenSSH */
2477 strncpy(prompt
+ challengelen
,
2478 memchr(prompt
, '\n', challengelen
) ?
2479 "": "\r\nResponse: ",
2480 (sizeof prompt
) - challengelen
);
2481 prompt
[(sizeof prompt
) - 1] = '\0';
2484 if (cfg
.try_tis_auth
&&
2485 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2486 !ccard_auth_refused
) {
2487 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2488 logevent("Requested CryptoCard authentication");
2489 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2491 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2492 logevent("CryptoCard authentication declined");
2493 c_write_str("CryptoCard authentication refused.\r\n");
2494 ccard_auth_refused
= 1;
2497 int challengelen
= ((pktin
.body
[0] << 24) |
2498 (pktin
.body
[1] << 16) |
2499 (pktin
.body
[2] << 8) |
2501 logevent("Received CryptoCard challenge");
2502 if (challengelen
> sizeof(prompt
) - 1)
2503 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2504 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2505 strncpy(prompt
+ challengelen
,
2506 memchr(prompt
, '\n', challengelen
) ?
2507 "" : "\r\nResponse: ",
2508 sizeof(prompt
) - challengelen
);
2509 prompt
[sizeof(prompt
) - 1] = '\0';
2512 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2513 sprintf(prompt
, "%.90s@%.90s's password: ",
2514 username
, savedhost
);
2516 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2517 char *comment
= NULL
;
2520 if (flags
& FLAG_VERBOSE
)
2521 c_write_str("Trying public key authentication.\r\n");
2522 sprintf(msgbuf
, "Trying public key \"%.200s\"", cfg
.keyfile
);
2524 type
= key_type(cfg
.keyfile
);
2525 if (type
!= SSH_KEYTYPE_SSH1
) {
2526 sprintf(msgbuf
, "Key is of wrong type (%s)",
2527 key_type_to_str(type
));
2529 c_write_str(msgbuf
);
2530 c_write_str("\r\n");
2531 tried_publickey
= 1;
2534 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2535 if (flags
& FLAG_VERBOSE
)
2536 c_write_str("No passphrase required.\r\n");
2539 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2544 * Show password prompt, having first obtained it via a TIS
2545 * or CryptoCard exchange if we're doing TIS or CryptoCard
2549 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2551 * get_line failed to get a password (for example
2552 * because one was supplied on the command line
2553 * which has already failed to work). Terminate.
2555 send_packet(SSH1_MSG_DISCONNECT
,
2556 PKT_STR
, "No more passwords available to try",
2558 logevent("Unable to authenticate");
2559 connection_fatal("Unable to authenticate");
2560 ssh_state
= SSH_STATE_CLOSED
;
2564 /* Prompt may have come from server. We've munged it a bit, so
2565 * we know it to be zero-terminated at least once. */
2566 c_write_untrusted(prompt
, strlen(prompt
));
2570 crWaitUntil(!ispkt
);
2572 switch (c
= *in
++) {
2592 if (pos
< sizeof(password
)-1)
2593 password
[pos
++] = c
;
2597 c_write_str("\r\n");
2601 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2603 * Try public key authentication with the specified
2606 static struct RSAKey pubkey
;
2607 static Bignum challenge
, response
;
2609 static unsigned char buffer
[32];
2611 tried_publickey
= 1;
2612 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2614 c_write_str("Couldn't load private key from ");
2615 c_write_str(cfg
.keyfile
);
2616 c_write_str(".\r\n");
2617 continue; /* go and try password */
2620 c_write_str("Wrong passphrase.\r\n");
2621 tried_publickey
= 0;
2622 continue; /* try again */
2626 * Send a public key attempt.
2628 send_packet(SSH1_CMSG_AUTH_RSA
,
2629 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2632 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2633 c_write_str("Server refused our public key.\r\n");
2634 continue; /* go and try password */
2636 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2637 bombout(("Bizarre response to offer of public key"));
2640 ssh1_read_bignum(pktin
.body
, &challenge
);
2641 response
= rsadecrypt(challenge
, &pubkey
);
2642 freebn(pubkey
.private_exponent
); /* burn the evidence */
2644 for (i
= 0; i
< 32; i
++) {
2645 buffer
[i
] = bignum_byte(response
, 31 - i
);
2649 MD5Update(&md5c
, buffer
, 32);
2650 MD5Update(&md5c
, session_id
, 16);
2651 MD5Final(buffer
, &md5c
);
2653 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2654 PKT_DATA
, buffer
, 16, PKT_END
);
2657 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2658 if (flags
& FLAG_VERBOSE
)
2660 ("Failed to authenticate with our public key.\r\n");
2661 continue; /* go and try password */
2662 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2664 ("Bizarre response to RSA authentication response"));
2668 break; /* we're through! */
2670 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2672 * Defence against traffic analysis: we send a
2673 * whole bunch of packets containing strings of
2674 * different lengths. One of these strings is the
2675 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2676 * The others are all random data in
2677 * SSH1_MSG_IGNORE packets. This way a passive
2678 * listener can't tell which is the password, and
2679 * hence can't deduce the password length.
2681 * Anybody with a password length greater than 16
2682 * bytes is going to have enough entropy in their
2683 * password that a listener won't find it _that_
2684 * much help to know how long it is. So what we'll
2687 * - if password length < 16, we send 15 packets
2688 * containing string lengths 1 through 15
2690 * - otherwise, we let N be the nearest multiple
2691 * of 8 below the password length, and send 8
2692 * packets containing string lengths N through
2693 * N+7. This won't obscure the order of
2694 * magnitude of the password length, but it will
2695 * introduce a bit of extra uncertainty.
2697 * A few servers (the old 1.2.18 through 1.2.22)
2698 * can't deal with SSH1_MSG_IGNORE. For these
2699 * servers, we need an alternative defence. We make
2700 * use of the fact that the password is interpreted
2701 * as a C string: so we can append a NUL, then some
2704 * One server (a Cisco one) can deal with neither
2705 * SSH1_MSG_IGNORE _nor_ a padded password string.
2706 * For this server we are left with no defences
2707 * against password length sniffing.
2709 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2711 * The server can deal with SSH1_MSG_IGNORE, so
2712 * we can use the primary defence.
2714 int bottom
, top
, pwlen
, i
;
2717 pwlen
= strlen(password
);
2719 bottom
= 0; /* zero length passwords are OK! :-) */
2722 bottom
= pwlen
& ~7;
2726 assert(pwlen
>= bottom
&& pwlen
<= top
);
2728 randomstr
= smalloc(top
+ 1);
2730 for (i
= bottom
; i
<= top
; i
++) {
2732 defer_packet(pwpkt_type
, PKT_STR
, password
,
2735 for (j
= 0; j
< i
; j
++) {
2737 randomstr
[j
] = random_byte();
2738 } while (randomstr
[j
] == '\0');
2740 randomstr
[i
] = '\0';
2741 defer_packet(SSH1_MSG_IGNORE
,
2742 PKT_STR
, randomstr
, PKT_END
);
2745 logevent("Sending password with camouflage packets");
2746 ssh_pkt_defersend();
2748 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2750 * The server can't deal with SSH1_MSG_IGNORE
2751 * but can deal with padded passwords, so we
2752 * can use the secondary defence.
2758 len
= strlen(password
);
2759 if (len
< sizeof(string
)) {
2761 strcpy(string
, password
);
2762 len
++; /* cover the zero byte */
2763 while (len
< sizeof(string
)) {
2764 string
[len
++] = (char) random_byte();
2769 logevent("Sending length-padded password");
2770 send_packet(pwpkt_type
, PKT_INT
, len
,
2771 PKT_DATA
, s
, len
, PKT_END
);
2774 * The server has _both_
2775 * BUG_CHOKES_ON_SSH1_IGNORE and
2776 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2777 * therefore nothing we can do.
2780 len
= strlen(password
);
2781 logevent("Sending unpadded password");
2782 send_packet(pwpkt_type
, PKT_INT
, len
,
2783 PKT_DATA
, password
, len
, PKT_END
);
2786 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2789 logevent("Sent password");
2790 memset(password
, 0, strlen(password
));
2792 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2793 if (flags
& FLAG_VERBOSE
)
2794 c_write_str("Access denied\r\n");
2795 logevent("Authentication refused");
2796 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2797 logevent("Received disconnect request");
2798 ssh_state
= SSH_STATE_CLOSED
;
2800 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2801 bombout(("Strange packet received, type %d", pktin
.type
));
2806 logevent("Authentication successful");
2811 void sshfwd_close(struct ssh_channel
*c
)
2813 if (c
&& !c
->closes
) {
2815 * If the channel's remoteid is -1, we have sent
2816 * CHANNEL_OPEN for this channel, but it hasn't even been
2817 * acknowledged by the server. So we must set a close flag
2818 * on it now, and then when the server acks the channel
2819 * open, we can close it then.
2821 if (((int)c
->remoteid
) != -1) {
2822 if (ssh_version
== 1) {
2823 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2826 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2827 ssh2_pkt_adduint32(c
->remoteid
);
2832 if (c
->type
== CHAN_X11
) {
2834 logevent("Forwarded X11 connection terminated");
2835 } else if (c
->type
== CHAN_SOCKDATA
||
2836 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2838 logevent("Forwarded port closed");
2843 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2845 if (ssh_version
== 1) {
2846 send_packet(SSH1_MSG_CHANNEL_DATA
,
2847 PKT_INT
, c
->remoteid
,
2848 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2850 * In SSH1 we can return 0 here - implying that forwarded
2851 * connections are never individually throttled - because
2852 * the only circumstance that can cause throttling will be
2853 * the whole SSH connection backing up, in which case
2854 * _everything_ will be throttled as a whole.
2858 ssh2_add_channel_data(c
, buf
, len
);
2859 return ssh2_try_send(c
);
2863 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2865 if (ssh_version
== 1) {
2866 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2867 c
->v
.v1
.throttling
= 0;
2871 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2875 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2881 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2884 if (ssh_state
== SSH_STATE_CLOSED
)
2887 if (cfg
.agentfwd
&& agent_exists()) {
2888 logevent("Requesting agent forwarding");
2889 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2893 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2894 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2895 bombout(("Protocol confusion"));
2897 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2898 logevent("Agent forwarding refused");
2900 logevent("Agent forwarding enabled");
2901 ssh_agentfwd_enabled
= TRUE
;
2905 if (cfg
.x11_forward
) {
2906 char proto
[20], data
[64];
2907 logevent("Requesting X11 forwarding");
2908 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2909 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2910 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2911 PKT_STR
, proto
, PKT_STR
, data
,
2912 PKT_INT
, 0, PKT_END
);
2914 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2915 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2920 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2921 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2922 bombout(("Protocol confusion"));
2924 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2925 logevent("X11 forwarding refused");
2927 logevent("X11 forwarding enabled");
2928 ssh_X11_fwd_enabled
= TRUE
;
2936 int sport
,dport
,sserv
,dserv
;
2937 char sports
[256], dports
[256], host
[256];
2941 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2942 /* Add port forwardings. */
2947 while (*e
&& *e
!= '\t')
2953 while (*e
&& *e
!= ':')
2963 dport
= atoi(dports
);
2967 se
= getservbyname(dports
, NULL
);
2969 dport
= ntohs(se
->s_port
);
2972 "Service lookup failed for destination port \"%s\"",
2977 sport
= atoi(sports
);
2981 se
= getservbyname(sports
, NULL
);
2983 sport
= ntohs(se
->s_port
);
2986 "Service lookup failed for source port \"%s\"",
2991 if (sport
&& dport
) {
2993 pfd_addforward(host
, dport
, sport
);
2994 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
2995 " %s:%.*s%.*s%d%.*s",
2996 sserv ?
strlen(sports
) : 0, sports
,
2997 sserv
, "(", sport
, sserv
, ")",
2999 dserv ?
strlen(dports
) : 0, dports
,
3000 dserv
, "(", dport
, dserv
, ")");
3003 struct ssh_rportfwd
*pf
;
3004 pf
= smalloc(sizeof(*pf
));
3005 strcpy(pf
->dhost
, host
);
3007 if (add234(ssh_rportfwds
, pf
) != pf
) {
3009 "Duplicate remote port forwarding to %s:%d",
3014 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
3015 " forward to %s:%.*s%.*s%d%.*s",
3016 sserv ?
strlen(sports
) : 0, sports
,
3017 sserv
, "(", sport
, sserv
, ")",
3019 dserv ?
strlen(dports
) : 0, dports
,
3020 dserv
, "(", dport
, dserv
, ")");
3022 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
3030 if (pktin
.type
!= SSH1_SMSG_SUCCESS
3031 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
3032 bombout(("Protocol confusion"));
3034 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3035 c_write_str("Server refused port forwarding\r\n");
3036 ssh_editing
= ssh_echoing
= 1;
3038 logevent("Remote port forwarding enabled");
3046 send_packet(SSH1_CMSG_REQUEST_PTY
,
3047 PKT_STR
, cfg
.termtype
,
3048 PKT_INT
, rows
, PKT_INT
, cols
,
3049 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3050 ssh_state
= SSH_STATE_INTERMED
;
3054 if (pktin
.type
!= SSH1_SMSG_SUCCESS
3055 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
3056 bombout(("Protocol confusion"));
3058 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3059 c_write_str("Server refused to allocate pty\r\n");
3060 ssh_editing
= ssh_echoing
= 1;
3062 logevent("Allocated pty");
3064 ssh_editing
= ssh_echoing
= 1;
3067 if (cfg
.compression
) {
3068 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3072 if (pktin
.type
!= SSH1_SMSG_SUCCESS
3073 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
3074 bombout(("Protocol confusion"));
3076 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3077 c_write_str("Server refused to compress\r\n");
3079 logevent("Started compression");
3080 ssh1_compressing
= TRUE
;
3081 zlib_compress_init();
3082 zlib_decompress_init();
3086 * Start the shell or command.
3088 * Special case: if the first-choice command is an SSH2
3089 * subsystem (hence not usable here) and the second choice
3090 * exists, we fall straight back to that.
3093 char *cmd
= cfg
.remote_cmd_ptr
;
3095 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
3096 cmd
= cfg
.remote_cmd_ptr2
;
3097 ssh_fallback_cmd
= TRUE
;
3100 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3102 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3103 logevent("Started session");
3106 ssh_state
= SSH_STATE_SESSION
;
3110 ssh_special(TS_EOF
);
3112 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
3114 ssh_channels
= newtree234(ssh_channelcmp
);
3118 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3119 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3120 long len
= GET_32BIT(pktin
.body
);
3122 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3123 pktin
.body
+ 4, len
);
3124 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3125 ssh1_stdout_throttling
= 1;
3128 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
3129 ssh_state
= SSH_STATE_CLOSED
;
3130 logevent("Received disconnect request");
3132 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3133 /* Remote side is trying to open a channel to talk to our
3134 * X-Server. Give them back a local channel number. */
3135 struct ssh_channel
*c
;
3137 logevent("Received X11 connect request");
3138 /* Refuse if X11 forwarding is disabled. */
3139 if (!ssh_X11_fwd_enabled
) {
3140 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3141 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3142 logevent("Rejected X11 connect request");
3144 c
= smalloc(sizeof(struct ssh_channel
));
3146 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
3147 logevent("opening X11 forward connection failed");
3149 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3150 PKT_INT
, GET_32BIT(pktin
.body
),
3154 ("opening X11 forward connection succeeded");
3155 c
->remoteid
= GET_32BIT(pktin
.body
);
3156 c
->localid
= alloc_channel_id();
3158 c
->v
.v1
.throttling
= 0;
3159 c
->type
= CHAN_X11
; /* identify channel type */
3160 add234(ssh_channels
, c
);
3161 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3162 PKT_INT
, c
->remoteid
, PKT_INT
,
3163 c
->localid
, PKT_END
);
3164 logevent("Opened X11 forward channel");
3167 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3168 /* Remote side is trying to open a channel to talk to our
3169 * agent. Give them back a local channel number. */
3170 struct ssh_channel
*c
;
3172 /* Refuse if agent forwarding is disabled. */
3173 if (!ssh_agentfwd_enabled
) {
3174 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3175 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3177 c
= smalloc(sizeof(struct ssh_channel
));
3178 c
->remoteid
= GET_32BIT(pktin
.body
);
3179 c
->localid
= alloc_channel_id();
3181 c
->v
.v1
.throttling
= 0;
3182 c
->type
= CHAN_AGENT
; /* identify channel type */
3183 c
->u
.a
.lensofar
= 0;
3184 add234(ssh_channels
, c
);
3185 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3186 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3189 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3190 /* Remote side is trying to open a channel to talk to a
3191 * forwarded port. Give them back a local channel number. */
3192 struct ssh_channel
*c
;
3193 struct ssh_rportfwd pf
;
3195 char host
[256], buf
[1024];
3197 c
= smalloc(sizeof(struct ssh_channel
));
3199 hostsize
= GET_32BIT(pktin
.body
+4);
3200 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
3201 if (h
+1 < host
+sizeof(host
))
3206 port
= GET_32BIT(p
);
3208 strcpy(pf
.dhost
, host
);
3211 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
3212 sprintf(buf
, "Rejected remote port open request for %s:%d",
3215 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3216 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
3218 sprintf(buf
, "Received remote port open request for %s:%d",
3221 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3224 sprintf(buf
, "Port open failed: %s", e
);
3227 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3228 PKT_INT
, GET_32BIT(pktin
.body
),
3231 c
->remoteid
= GET_32BIT(pktin
.body
);
3232 c
->localid
= alloc_channel_id();
3234 c
->v
.v1
.throttling
= 0;
3235 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3236 add234(ssh_channels
, c
);
3237 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3238 PKT_INT
, c
->remoteid
, PKT_INT
,
3239 c
->localid
, PKT_END
);
3240 logevent("Forwarded port opened successfully");
3244 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3245 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3246 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3247 struct ssh_channel
*c
;
3249 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3250 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3251 c
->remoteid
= localid
;
3252 c
->type
= CHAN_SOCKDATA
;
3253 c
->v
.v1
.throttling
= 0;
3254 pfd_confirm(c
->u
.pfd
.s
);
3257 if (c
&& c
->closes
) {
3259 * We have a pending close on this channel,
3260 * which we decided on before the server acked
3261 * the channel open. So now we know the
3262 * remoteid, we can close it again.
3264 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
3268 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3269 unsigned int remoteid
= GET_32BIT(pktin
.body
);
3270 unsigned int localid
= GET_32BIT(pktin
.body
+4);
3271 struct ssh_channel
*c
;
3273 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
3274 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3275 logevent("Forwarded connection refused by server");
3276 pfd_close(c
->u
.pfd
.s
);
3277 del234(ssh_channels
, c
);
3281 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3282 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3283 /* Remote side closes a channel. */
3284 unsigned i
= GET_32BIT(pktin
.body
);
3285 struct ssh_channel
*c
;
3286 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3290 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3291 if (!(c
->closes
& closetype
))
3292 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
3294 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3295 logevent("Forwarded X11 connection terminated");
3296 assert(c
->u
.x11
.s
!= NULL
);
3297 x11_close(c
->u
.x11
.s
);
3300 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3301 logevent("Forwarded port closed");
3302 assert(c
->u
.pfd
.s
!= NULL
);
3303 pfd_close(c
->u
.pfd
.s
);
3306 c
->closes
|= closetype
;
3307 if (c
->closes
== 3) {
3308 del234(ssh_channels
, c
);
3312 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3313 /* Data sent down one of our channels. */
3314 int i
= GET_32BIT(pktin
.body
);
3315 int len
= GET_32BIT(pktin
.body
+ 4);
3316 unsigned char *p
= pktin
.body
+ 8;
3317 struct ssh_channel
*c
;
3318 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3323 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3326 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3329 /* Data for an agent message. Buffer it. */
3331 if (c
->u
.a
.lensofar
< 4) {
3332 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3333 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3337 c
->u
.a
.lensofar
+= l
;
3339 if (c
->u
.a
.lensofar
== 4) {
3341 4 + GET_32BIT(c
->u
.a
.msglen
);
3342 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3343 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3345 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3347 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3349 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3353 c
->u
.a
.lensofar
+= l
;
3355 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3356 void *reply
, *sentreply
;
3358 agent_query(c
->u
.a
.message
,
3359 c
->u
.a
.totallen
, &reply
,
3364 /* Fake SSH_AGENT_FAILURE. */
3365 sentreply
= "\0\0\0\1\5";
3368 send_packet(SSH1_MSG_CHANNEL_DATA
,
3369 PKT_INT
, c
->remoteid
,
3371 PKT_DATA
, sentreply
, replylen
,
3375 sfree(c
->u
.a
.message
);
3376 c
->u
.a
.lensofar
= 0;
3379 bufsize
= 0; /* agent channels never back up */
3382 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3383 c
->v
.v1
.throttling
= 1;
3387 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3388 /* may be from EXEC_SHELL on some servers */
3389 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3390 /* may be from EXEC_SHELL on some servers
3391 * if no pty is available or in other odd cases. Ignore */
3392 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3394 ssh_exitcode
= GET_32BIT(pktin
.body
);
3395 sprintf(buf
, "Server sent command exit status %d",
3398 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3400 * In case `helpful' firewalls or proxies tack
3401 * extra human-readable text on the end of the
3402 * session which we might mistake for another
3403 * encrypted packet, we close the session once
3404 * we've sent EXIT_CONFIRMATION.
3406 ssh_state
= SSH_STATE_CLOSED
;
3409 bombout(("Strange packet received: type %d", pktin
.type
));
3414 int len
= min(inlen
, 512);
3415 send_packet(SSH1_CMSG_STDIN_DATA
,
3416 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3427 * Utility routine for decoding comma-separated strings in KEXINIT.
3429 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3431 int needlen
= strlen(needle
);
3434 * Is it at the start of the string?
3436 if (haylen
>= needlen
&& /* haystack is long enough */
3437 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3438 (haylen
== needlen
|| haystack
[needlen
] == ',')
3439 /* either , or EOS follows */
3443 * If not, search for the next comma and resume after that.
3444 * If no comma found, terminate.
3446 while (haylen
> 0 && *haystack
!= ',')
3447 haylen
--, haystack
++;
3450 haylen
--, haystack
++; /* skip over comma itself */
3455 * SSH2 key creation method.
3457 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3461 /* First 20 bytes. */
3464 SHA_Bytes(&s
, H
, 20);
3465 SHA_Bytes(&s
, &chr
, 1);
3466 SHA_Bytes(&s
, sessid
, 20);
3467 SHA_Final(&s
, keyspace
);
3468 /* Next 20 bytes. */
3471 SHA_Bytes(&s
, H
, 20);
3472 SHA_Bytes(&s
, keyspace
, 20);
3473 SHA_Final(&s
, keyspace
+ 20);
3477 * Handle the SSH2 transport layer.
3479 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3481 static int i
, j
, len
, nbits
, pbits
, warn
;
3483 static Bignum p
, g
, e
, f
, K
;
3484 static int kex_init_value
, kex_reply_value
;
3485 static const struct ssh_mac
**maclist
;
3487 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3488 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3489 static const struct ssh_mac
*csmac_tobe
= NULL
;
3490 static const struct ssh_mac
*scmac_tobe
= NULL
;
3491 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3492 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3493 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3494 static int hostkeylen
, siglen
;
3495 static void *hkey
; /* actual host key */
3496 static unsigned char exchange_hash
[20];
3497 static unsigned char keyspace
[40];
3498 static int n_preferred_ciphers
;
3499 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3500 static const struct ssh_compress
*preferred_comp
;
3501 static int cipherstr_started
;
3502 static int first_kex
;
3509 * Set up the preferred ciphers. (NULL => warn below here)
3511 n_preferred_ciphers
= 0;
3512 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3513 switch (cfg
.ssh_cipherlist
[i
]) {
3514 case CIPHER_BLOWFISH
:
3515 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3516 n_preferred_ciphers
++;
3519 if (cfg
.ssh2_des_cbc
) {
3520 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3521 n_preferred_ciphers
++;
3525 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3526 n_preferred_ciphers
++;
3529 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3530 n_preferred_ciphers
++;
3533 /* Flag for later. Don't bother if it's the last in
3535 if (i
< CIPHER_MAX
- 1) {
3536 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3537 n_preferred_ciphers
++;
3544 * Set up preferred compression.
3546 if (cfg
.compression
)
3547 preferred_comp
= &ssh_zlib
;
3549 preferred_comp
= &ssh_comp_none
;
3552 * Be prepared to work around the buggy MAC problem.
3554 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3555 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3557 maclist
= macs
, nmacs
= lenof(macs
);
3561 * Construct and send our key exchange packet.
3563 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3564 for (i
= 0; i
< 16; i
++)
3565 ssh2_pkt_addbyte((unsigned char) random_byte());
3566 /* List key exchange algorithms. */
3567 ssh2_pkt_addstring_start();
3568 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3569 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3570 if (i
< lenof(kex_algs
) - 1)
3571 ssh2_pkt_addstring_str(",");
3573 /* List server host key algorithms. */
3574 ssh2_pkt_addstring_start();
3575 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3576 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3577 if (i
< lenof(hostkey_algs
) - 1)
3578 ssh2_pkt_addstring_str(",");
3580 /* List client->server encryption algorithms. */
3581 ssh2_pkt_addstring_start();
3582 cipherstr_started
= 0;
3583 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3584 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3585 if (!c
) continue; /* warning flag */
3586 for (j
= 0; j
< c
->nciphers
; j
++) {
3587 if (cipherstr_started
)
3588 ssh2_pkt_addstring_str(",");
3589 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3590 cipherstr_started
= 1;
3593 /* List server->client encryption algorithms. */
3594 ssh2_pkt_addstring_start();
3595 cipherstr_started
= 0;
3596 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3597 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3598 if (!c
) continue; /* warning flag */
3599 for (j
= 0; j
< c
->nciphers
; j
++) {
3600 if (cipherstr_started
)
3601 ssh2_pkt_addstring_str(",");
3602 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3603 cipherstr_started
= 1;
3606 /* List client->server MAC algorithms. */
3607 ssh2_pkt_addstring_start();
3608 for (i
= 0; i
< nmacs
; i
++) {
3609 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3611 ssh2_pkt_addstring_str(",");
3613 /* List server->client MAC algorithms. */
3614 ssh2_pkt_addstring_start();
3615 for (i
= 0; i
< nmacs
; i
++) {
3616 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3618 ssh2_pkt_addstring_str(",");
3620 /* List client->server compression algorithms. */
3621 ssh2_pkt_addstring_start();
3622 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3623 const struct ssh_compress
*c
=
3624 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3625 ssh2_pkt_addstring_str(c
->name
);
3626 if (i
< lenof(compressions
))
3627 ssh2_pkt_addstring_str(",");
3629 /* List server->client compression algorithms. */
3630 ssh2_pkt_addstring_start();
3631 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3632 const struct ssh_compress
*c
=
3633 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3634 ssh2_pkt_addstring_str(c
->name
);
3635 if (i
< lenof(compressions
))
3636 ssh2_pkt_addstring_str(",");
3638 /* List client->server languages. Empty list. */
3639 ssh2_pkt_addstring_start();
3640 /* List server->client languages. Empty list. */
3641 ssh2_pkt_addstring_start();
3642 /* First KEX packet does _not_ follow, because we're not that brave. */
3643 ssh2_pkt_addbool(FALSE
);
3645 ssh2_pkt_adduint32(0);
3647 exhash
= exhashbase
;
3648 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3654 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3657 * Now examine the other side's KEXINIT to see what we're up
3660 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3661 bombout(("expected key exchange packet from server"));
3666 cscipher_tobe
= NULL
;
3667 sccipher_tobe
= NULL
;
3672 pktin
.savedpos
+= 16; /* skip garbage cookie */
3673 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3674 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3675 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3680 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3681 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3682 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3683 hostkey
= hostkey_algs
[i
];
3687 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3689 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3690 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3694 for (j
= 0; j
< c
->nciphers
; j
++) {
3695 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3696 cscipher_tobe
= c
->list
[j
];
3701 if (cscipher_tobe
) {
3703 askcipher(cscipher_tobe
->name
, 1);
3707 if (!cscipher_tobe
) {
3708 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3712 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3714 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3715 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3719 for (j
= 0; j
< c
->nciphers
; j
++) {
3720 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3721 sccipher_tobe
= c
->list
[j
];
3726 if (sccipher_tobe
) {
3728 askcipher(sccipher_tobe
->name
, 2);
3732 if (!sccipher_tobe
) {
3733 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3737 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3738 for (i
= 0; i
< nmacs
; i
++) {
3739 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3740 csmac_tobe
= maclist
[i
];
3744 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3745 for (i
= 0; i
< nmacs
; i
++) {
3746 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3747 scmac_tobe
= maclist
[i
];
3751 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3752 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3753 const struct ssh_compress
*c
=
3754 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3755 if (in_commasep_string(c
->name
, str
, len
)) {
3760 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3761 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3762 const struct ssh_compress
*c
=
3763 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3764 if (in_commasep_string(c
->name
, str
, len
)) {
3771 * Work out the number of bits of key we will need from the key
3772 * exchange. We start with the maximum key length of either
3778 csbits
= cscipher_tobe
->keylen
;
3779 scbits
= sccipher_tobe
->keylen
;
3780 nbits
= (csbits
> scbits ? csbits
: scbits
);
3782 /* The keys only have 160-bit entropy, since they're based on
3783 * a SHA-1 hash. So cap the key size at 160 bits. */
3788 * If we're doing Diffie-Hellman group exchange, start by
3789 * requesting a group.
3791 if (kex
== &ssh_diffiehellman_gex
) {
3792 logevent("Doing Diffie-Hellman group exchange");
3793 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3795 * Work out how big a DH group we will need to allow that
3798 pbits
= 512 << ((nbits
- 1) / 64);
3799 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3800 ssh2_pkt_adduint32(pbits
);
3804 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3805 bombout(("expected key exchange group packet from server"));
3808 p
= ssh2_pkt_getmp();
3809 g
= ssh2_pkt_getmp();
3810 dh_setup_group(p
, g
);
3811 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3812 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3814 ssh_pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3816 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3817 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3820 logevent("Doing Diffie-Hellman key exchange");
3822 * Now generate and send e for Diffie-Hellman.
3824 e
= dh_create_e(nbits
* 2);
3825 ssh2_pkt_init(kex_init_value
);
3830 if (pktin
.type
!= kex_reply_value
) {
3831 bombout(("expected key exchange reply packet from server"));
3834 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3835 f
= ssh2_pkt_getmp();
3836 ssh2_pkt_getstring(&sigdata
, &siglen
);
3840 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3841 if (kex
== &ssh_diffiehellman_gex
) {
3842 sha_uint32(&exhash
, pbits
);
3843 sha_mpint(&exhash
, p
);
3844 sha_mpint(&exhash
, g
);
3846 sha_mpint(&exhash
, e
);
3847 sha_mpint(&exhash
, f
);
3848 sha_mpint(&exhash
, K
);
3849 SHA_Final(&exhash
, exchange_hash
);
3854 debug(("Exchange hash is:\n"));
3855 dmemdump(exchange_hash
, 20);
3858 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3860 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3861 bombout(("Server's host key did not match the signature supplied"));
3866 * Authenticate remote host: verify host key. (We've already
3867 * checked the signature of the exchange hash.)
3869 keystr
= hostkey
->fmtkey(hkey
);
3870 fingerprint
= hostkey
->fingerprint(hkey
);
3871 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3872 keystr
, fingerprint
);
3873 if (first_kex
) { /* don't bother logging this in rekeys */
3874 logevent("Host key fingerprint is:");
3875 logevent(fingerprint
);
3879 hostkey
->freekey(hkey
);
3882 * Send SSH2_MSG_NEWKEYS.
3884 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3888 * Expect SSH2_MSG_NEWKEYS from server.
3891 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3892 bombout(("expected new-keys packet from server"));
3897 * Create and initialise session keys.
3899 cscipher
= cscipher_tobe
;
3900 sccipher
= sccipher_tobe
;
3903 cscomp
= cscomp_tobe
;
3904 sccomp
= sccomp_tobe
;
3905 cscomp
->compress_init();
3906 sccomp
->decompress_init();
3908 * Set IVs after keys. Here we use the exchange hash from the
3909 * _first_ key exchange.
3912 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3913 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3914 cscipher
->setcskey(keyspace
);
3915 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3916 sccipher
->setsckey(keyspace
);
3917 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3918 cscipher
->setcsiv(keyspace
);
3919 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3920 sccipher
->setsciv(keyspace
);
3921 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3922 csmac
->setcskey(keyspace
);
3923 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3924 scmac
->setsckey(keyspace
);
3927 * If this is the first key exchange phase, we must pass the
3928 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3929 * wants to see it but because it will need time to initialise
3930 * itself before it sees an actual packet. In subsequent key
3931 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3932 * it would only confuse the layer above.
3940 * Now we're encrypting. Begin returning 1 to the protocol main
3941 * function so that other things can run on top of the
3942 * transport. If we ever see a KEXINIT, we must go back to the
3945 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3948 logevent("Server initiated key re-exchange");
3949 goto begin_key_exchange
;
3955 * Add data to an SSH2 channel output buffer.
3957 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3960 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3964 * Attempt to send data on an SSH2 channel.
3966 static int ssh2_try_send(struct ssh_channel
*c
)
3968 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3971 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3972 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3973 len
= c
->v
.v2
.remwindow
;
3974 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3975 len
= c
->v
.v2
.remmaxpkt
;
3976 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3977 ssh2_pkt_adduint32(c
->remoteid
);
3978 ssh2_pkt_addstring_start();
3979 ssh2_pkt_addstring_data(data
, len
);
3981 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3982 c
->v
.v2
.remwindow
-= len
;
3986 * After having sent as much data as we can, return the amount
3989 return bufchain_size(&c
->v
.v2
.outbuffer
);
3993 * Potentially enlarge the window on an SSH2 channel.
3995 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3998 * Never send WINDOW_ADJUST for a channel that the remote side
3999 * already thinks it's closed; there's no point, since it won't
4000 * be sending any more data anyway.
4005 if (newwin
> c
->v
.v2
.locwindow
) {
4006 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4007 ssh2_pkt_adduint32(c
->remoteid
);
4008 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
4010 c
->v
.v2
.locwindow
= newwin
;
4015 * Handle the SSH2 userauth and connection layers.
4017 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
4020 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4022 AUTH_KEYBOARD_INTERACTIVE
4026 AUTH_TYPE_PUBLICKEY
,
4027 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4028 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4030 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4031 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4033 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4034 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4035 static int kbd_inter_running
;
4036 static int we_are_in
;
4037 static int num_prompts
, echo
;
4038 static char username
[100];
4039 static int got_username
;
4040 static char pwprompt
[200];
4041 static char password
[100];
4042 static void *publickey_blob
;
4043 static int publickey_bloblen
;
4048 * Request userauth protocol, and await a response to it.
4050 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
4051 ssh2_pkt_addstring("ssh-userauth");
4053 crWaitUntilV(ispkt
);
4054 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4055 bombout(("Server refused user authentication protocol"));
4060 * We repeat this whole loop, including the username prompt,
4061 * until we manage a successful authentication. If the user
4062 * types the wrong _password_, they are sent back to the
4063 * beginning to try another username. (If they specify a
4064 * username in the config, they are never asked, even if they
4065 * do give a wrong password.)
4067 * I think this best serves the needs of
4069 * - the people who have no configuration, no keys, and just
4070 * want to try repeated (username,password) pairs until they
4071 * type both correctly
4073 * - people who have keys and configuration but occasionally
4074 * need to fall back to passwords
4076 * - people with a key held in Pageant, who might not have
4077 * logged in to a particular machine before; so they want to
4078 * type a username, and then _either_ their key will be
4079 * accepted, _or_ they will type a password. If they mistype
4080 * the username they will want to be able to get back and
4084 got_username
= FALSE
;
4093 if (got_username
&& !cfg
.change_username
) {
4095 * We got a username last time round this loop, and
4096 * with change_username turned off we don't try to get
4099 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
4101 if (!ssh_get_line("login as: ",
4102 username
, sizeof(username
), FALSE
)) {
4104 * get_line failed to get a username.
4107 logevent("No username provided. Abandoning session.");
4108 ssh_state
= SSH_STATE_CLOSED
;
4112 c_write_str("login as: ");
4115 crWaitUntilV(!ispkt
);
4117 switch (c
= *in
++) {
4126 c_write_str("\b \b");
4133 c_write_str("\b \b");
4142 if (((c
>= ' ' && c
<= '~') ||
4143 ((unsigned char) c
>= 160))
4144 && pos
< sizeof(username
)-1) {
4145 username
[pos
++] = c
;
4152 c_write_str("\r\n");
4153 username
[strcspn(username
, "\n\r")] = '\0';
4156 strncpy(username
, cfg
.username
, 99);
4157 username
[99] = '\0';
4158 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4159 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
4163 got_username
= TRUE
;
4166 * Send an authentication request using method "none": (a)
4167 * just in case it succeeds, and (b) so that we know what
4168 * authentication methods we can usefully try next.
4170 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4172 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4173 ssh2_pkt_addstring(username
);
4174 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4175 ssh2_pkt_addstring("none"); /* method */
4177 type
= AUTH_TYPE_NONE
;
4181 tried_pubkey_config
= FALSE
;
4182 tried_agent
= FALSE
;
4183 tried_keyb_inter
= FALSE
;
4184 kbd_inter_running
= FALSE
;
4185 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4188 logeventf("Reading private key file \"%.150s\"", cfg
.keyfile
);
4189 keytype
= key_type(cfg
.keyfile
);
4190 if (keytype
== SSH_KEYTYPE_SSH2
)
4191 publickey_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4192 &publickey_bloblen
);
4195 logeventf("Unable to use this key file (%s)",
4196 key_type_to_str(keytype
));
4197 sprintf(msgbuf
, "Unable to use key file \"%.150s\" (%s)\r\n",
4198 cfg
.keyfile
, key_type_to_str(keytype
));
4199 c_write_str(msgbuf
);
4200 publickey_blob
= NULL
;
4203 publickey_blob
= NULL
;
4207 * Wait for the result of the last authentication request.
4210 crWaitUntilV(ispkt
);
4211 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4215 * Don't show the banner if we're operating in
4216 * non-verbose non-interactive mode. (It's probably
4217 * a script, which means nobody will read the
4218 * banner _anyway_, and moreover the printing of
4219 * the banner will screw up processing on the
4220 * output of (say) plink.)
4222 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4223 ssh2_pkt_getstring(&banner
, &size
);
4225 c_write_untrusted(banner
, size
);
4227 crWaitUntilV(ispkt
);
4229 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4230 logevent("Access granted");
4235 if (kbd_inter_running
&&
4236 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4238 * This is a further prompt in keyboard-interactive
4239 * authentication. Do nothing.
4241 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4242 bombout(("Strange packet received during authentication: type %d",
4250 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4251 * we can look at the string in it and know what we can
4252 * helpfully try next.
4254 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4257 ssh2_pkt_getstring(&methods
, &methlen
);
4258 kbd_inter_running
= FALSE
;
4259 if (!ssh2_pkt_getbool()) {
4261 * We have received an unequivocal Access
4262 * Denied. This can translate to a variety of
4265 * - if we'd just tried "none" authentication,
4266 * it's not worth printing anything at all
4268 * - if we'd just tried a public key _offer_,
4269 * the message should be "Server refused our
4270 * key" (or no message at all if the key
4271 * came from Pageant)
4273 * - if we'd just tried anything else, the
4274 * message really should be "Access denied".
4276 * Additionally, if we'd just tried password
4277 * authentication, we should break out of this
4278 * whole loop so as to go back to the username
4281 if (type
== AUTH_TYPE_NONE
) {
4283 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4284 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4285 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4286 c_write_str("Server refused our key\r\n");
4287 logevent("Server refused public key");
4288 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4289 /* server declined keyboard-interactive; ignore */
4291 c_write_str("Access denied\r\n");
4292 logevent("Access denied");
4293 if (type
== AUTH_TYPE_PASSWORD
) {
4299 c_write_str("Further authentication required\r\n");
4300 logevent("Further authentication required");
4304 in_commasep_string("publickey", methods
, methlen
);
4306 in_commasep_string("password", methods
, methlen
);
4307 can_keyb_inter
= cfg
.try_ki_auth
&&
4308 in_commasep_string("keyboard-interactive", methods
, methlen
);
4312 ssh_pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4314 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
4316 * Attempt public-key authentication using Pageant.
4318 static unsigned char request
[5], *response
, *p
;
4319 static int responselen
;
4320 static int i
, nkeys
;
4321 static int authed
= FALSE
;
4324 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4328 logevent("Pageant is running. Requesting keys.");
4330 /* Request the keys held by the agent. */
4331 PUT_32BIT(request
, 1);
4332 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4333 agent_query(request
, 5, &r
, &responselen
);
4334 response
= (unsigned char *) r
;
4335 if (response
&& responselen
>= 5 &&
4336 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4338 nkeys
= GET_32BIT(p
);
4342 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
4345 for (i
= 0; i
< nkeys
; i
++) {
4346 static char *pkblob
, *alg
, *commentp
;
4347 static int pklen
, alglen
, commentlen
;
4348 static int siglen
, retlen
, len
;
4349 static char *q
, *agentreq
, *ret
;
4354 sprintf(buf
, "Trying Pageant key #%d", i
);
4357 pklen
= GET_32BIT(p
);
4359 if (publickey_blob
&&
4360 pklen
== publickey_bloblen
&&
4361 !memcmp(p
, publickey_blob
, publickey_bloblen
)) {
4362 logevent("This key matches configured key file");
4363 tried_pubkey_config
= 1;
4367 alglen
= GET_32BIT(pkblob
);
4369 commentlen
= GET_32BIT(p
);
4373 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4374 ssh2_pkt_addstring(username
);
4375 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4376 ssh2_pkt_addstring("publickey"); /* method */
4377 ssh2_pkt_addbool(FALSE
); /* no signature included */
4378 ssh2_pkt_addstring_start();
4379 ssh2_pkt_addstring_data(alg
, alglen
);
4380 ssh2_pkt_addstring_start();
4381 ssh2_pkt_addstring_data(pkblob
, pklen
);
4384 crWaitUntilV(ispkt
);
4385 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4386 logevent("Key refused");
4390 if (flags
& FLAG_VERBOSE
) {
4392 ("Authenticating with public key \"");
4393 c_write(commentp
, commentlen
);
4394 c_write_str("\" from agent\r\n");
4398 * Server is willing to accept the key.
4399 * Construct a SIGN_REQUEST.
4401 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4402 ssh2_pkt_addstring(username
);
4403 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4404 ssh2_pkt_addstring("publickey"); /* method */
4405 ssh2_pkt_addbool(TRUE
);
4406 ssh2_pkt_addstring_start();
4407 ssh2_pkt_addstring_data(alg
, alglen
);
4408 ssh2_pkt_addstring_start();
4409 ssh2_pkt_addstring_data(pkblob
, pklen
);
4411 siglen
= pktout
.length
- 5 + 4 + 20;
4412 len
= 1; /* message type */
4413 len
+= 4 + pklen
; /* key blob */
4414 len
+= 4 + siglen
; /* data to sign */
4415 len
+= 4; /* flags */
4416 agentreq
= smalloc(4 + len
);
4417 PUT_32BIT(agentreq
, len
);
4419 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4420 PUT_32BIT(q
, pklen
);
4422 memcpy(q
, pkblob
, pklen
);
4424 PUT_32BIT(q
, siglen
);
4426 /* Now the data to be signed... */
4429 memcpy(q
, ssh2_session_id
, 20);
4431 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4432 q
+= pktout
.length
- 5;
4433 /* And finally the (zero) flags word. */
4435 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4439 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4440 logevent("Sending Pageant's response");
4441 ssh2_add_sigblob(pkblob
, pklen
,
4442 ret
+ 9, GET_32BIT(ret
+ 5));
4448 ("Pageant failed to answer challenge");
4458 if (!method
&& can_pubkey
&& publickey_blob
4459 && !tried_pubkey_config
) {
4460 unsigned char *pub_blob
;
4461 char *algorithm
, *comment
;
4464 tried_pubkey_config
= TRUE
;
4466 ssh_pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4469 * Try the public key supplied in the configuration.
4471 * First, offer the public blob to see if the server is
4472 * willing to accept it.
4474 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4477 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4478 ssh2_pkt_addstring(username
);
4479 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4480 ssh2_pkt_addstring("publickey"); /* method */
4481 ssh2_pkt_addbool(FALSE
); /* no signature included */
4482 ssh2_pkt_addstring(algorithm
);
4483 ssh2_pkt_addstring_start();
4484 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4486 logevent("Offered public key"); /* FIXME */
4488 crWaitUntilV(ispkt
);
4489 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4491 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4492 continue; /* key refused; give up on it */
4495 logevent("Offer of public key accepted");
4497 * Actually attempt a serious authentication using
4500 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4502 "Passphrase for key \"%.100s\": ",
4508 c_write_str("Authenticating with public key \"");
4509 c_write_str(comment
);
4510 c_write_str("\"\r\n");
4511 method
= AUTH_PUBLICKEY_FILE
;
4515 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4516 method
= AUTH_KEYBOARD_INTERACTIVE
;
4517 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4518 tried_keyb_inter
= TRUE
;
4520 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4522 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4523 ssh2_pkt_addstring(username
);
4524 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4525 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4526 ssh2_pkt_addstring(""); /* lang */
4527 ssh2_pkt_addstring("");
4530 crWaitUntilV(ispkt
);
4531 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4532 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4534 logevent("Keyboard-interactive authentication refused");
4535 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4539 kbd_inter_running
= TRUE
;
4542 if (kbd_inter_running
) {
4543 method
= AUTH_KEYBOARD_INTERACTIVE
;
4544 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4545 tried_keyb_inter
= TRUE
;
4547 ssh_pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4549 /* We've got packet with that "interactive" info
4550 dump banners, and set its prompt as ours */
4552 char *name
, *inst
, *lang
, *prompt
;
4553 int name_len
, inst_len
, lang_len
, prompt_len
;
4554 ssh2_pkt_getstring(&name
, &name_len
);
4555 ssh2_pkt_getstring(&inst
, &inst_len
);
4556 ssh2_pkt_getstring(&lang
, &lang_len
);
4558 c_write_untrusted(name
, name_len
);
4560 c_write_untrusted(inst
, inst_len
);
4561 num_prompts
= ssh2_pkt_getuint32();
4563 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4564 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4565 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4566 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4569 echo
= ssh2_pkt_getbool();
4573 if (!method
&& can_passwd
) {
4574 method
= AUTH_PASSWORD
;
4575 ssh_pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4576 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4583 if (!ssh_get_line(pwprompt
, password
,
4584 sizeof(password
), TRUE
)) {
4586 * get_line failed to get a password (for
4587 * example because one was supplied on the
4588 * command line which has already failed to
4591 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4592 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4594 ("No more passwords available to try");
4595 ssh2_pkt_addstring("en"); /* language tag */
4597 logevent("Unable to authenticate");
4598 connection_fatal("Unable to authenticate");
4599 ssh_state
= SSH_STATE_CLOSED
;
4606 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4611 crWaitUntilV(!ispkt
);
4613 switch (c
= *in
++) {
4633 if (pos
< sizeof(password
)-1)
4634 password
[pos
++] = c
;
4638 c_write_str("\r\n");
4642 if (method
== AUTH_PUBLICKEY_FILE
) {
4644 * We have our passphrase. Now try the actual authentication.
4646 struct ssh2_userkey
*key
;
4648 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4649 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4650 if (key
== SSH2_WRONG_PASSPHRASE
) {
4651 c_write_str("Wrong passphrase\r\n");
4652 tried_pubkey_config
= FALSE
;
4654 c_write_str("Unable to load private key\r\n");
4655 tried_pubkey_config
= TRUE
;
4657 /* Send a spurious AUTH_NONE to return to the top. */
4658 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4659 ssh2_pkt_addstring(username
);
4660 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4661 ssh2_pkt_addstring("none"); /* method */
4663 type
= AUTH_TYPE_NONE
;
4665 unsigned char *pkblob
, *sigblob
, *sigdata
;
4666 int pkblob_len
, sigblob_len
, sigdata_len
;
4669 * We have loaded the private key and the server
4670 * has announced that it's willing to accept it.
4671 * Hallelujah. Generate a signature and send it.
4673 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4674 ssh2_pkt_addstring(username
);
4675 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4676 ssh2_pkt_addstring("publickey"); /* method */
4677 ssh2_pkt_addbool(TRUE
);
4678 ssh2_pkt_addstring(key
->alg
->name
);
4679 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4680 ssh2_pkt_addstring_start();
4681 ssh2_pkt_addstring_data(pkblob
, pkblob_len
);
4684 * The data to be signed is:
4688 * followed by everything so far placed in the
4691 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4692 sigdata
= smalloc(sigdata_len
);
4693 PUT_32BIT(sigdata
, 20);
4694 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4695 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4697 sigblob
= key
->alg
->sign(key
->data
, sigdata
,
4698 sigdata_len
, &sigblob_len
);
4699 ssh2_add_sigblob(pkblob
, pkblob_len
,
4700 sigblob
, sigblob_len
);
4706 type
= AUTH_TYPE_PUBLICKEY
;
4708 } else if (method
== AUTH_PASSWORD
) {
4710 * We send the password packet lumped tightly together with
4711 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4712 * string long enough to make the total length of the two
4713 * packets constant. This should ensure that a passive
4714 * listener doing traffic analyis can't work out the length
4717 * For this to work, we need an assumption about the
4718 * maximum length of the password packet. I think 256 is
4719 * pretty conservative. Anyone using a password longer than
4720 * that probably doesn't have much to worry about from
4721 * people who find out how long their password is!
4723 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4724 ssh2_pkt_addstring(username
);
4725 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4726 ssh2_pkt_addstring("password");
4727 ssh2_pkt_addbool(FALSE
);
4728 ssh2_pkt_addstring(password
);
4731 * We'll include a string that's an exact multiple of the
4732 * cipher block size. If the cipher is NULL for some
4733 * reason, we don't do this trick at all because we gain
4739 stringlen
= (256 - deferred_len
);
4740 stringlen
+= cscipher
->blksize
- 1;
4741 stringlen
-= (stringlen
% cscipher
->blksize
);
4744 * Temporarily disable actual compression,
4745 * so we can guarantee to get this string
4746 * exactly the length we want it. The
4747 * compression-disabling routine should
4748 * return an integer indicating how many
4749 * bytes we should adjust our string length
4752 stringlen
-= cscomp
->disable_compression();
4754 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4755 ssh2_pkt_addstring_start();
4756 for (i
= 0; i
< stringlen
; i
++) {
4757 char c
= (char) random_byte();
4758 ssh2_pkt_addstring_data(&c
, 1);
4762 ssh_pkt_defersend();
4763 logevent("Sent password");
4764 type
= AUTH_TYPE_PASSWORD
;
4765 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4766 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4767 ssh2_pkt_adduint32(num_prompts
);
4768 ssh2_pkt_addstring(password
);
4769 memset(password
, 0, sizeof(password
));
4771 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4774 ("No supported authentication methods left to try!\r\n");
4776 ("No supported authentications offered. Disconnecting");
4777 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4778 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4780 ("No supported authentication methods available");
4781 ssh2_pkt_addstring("en"); /* language tag */
4783 ssh_state
= SSH_STATE_CLOSED
;
4787 } while (!we_are_in
);
4790 * Now we're authenticated for the connection protocol. The
4791 * connection protocol will automatically have started at this
4792 * point; there's no need to send SERVICE_REQUEST.
4796 * So now create a channel with a session in it.
4798 ssh_channels
= newtree234(ssh_channelcmp
);
4799 mainchan
= smalloc(sizeof(struct ssh_channel
));
4800 mainchan
->localid
= alloc_channel_id();
4801 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4802 ssh2_pkt_addstring("session");
4803 ssh2_pkt_adduint32(mainchan
->localid
);
4804 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4805 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4806 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4808 crWaitUntilV(ispkt
);
4809 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4810 bombout(("Server refused to open a session"));
4812 /* FIXME: error data comes back in FAILURE packet */
4814 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4815 bombout(("Server's channel confirmation cited wrong channel"));
4818 mainchan
->remoteid
= ssh2_pkt_getuint32();
4819 mainchan
->type
= CHAN_MAINSESSION
;
4820 mainchan
->closes
= 0;
4821 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4822 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4823 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4824 add234(ssh_channels
, mainchan
);
4825 logevent("Opened channel for session");
4828 * Potentially enable X11 forwarding.
4830 if (cfg
.x11_forward
) {
4831 char proto
[20], data
[64];
4832 logevent("Requesting X11 forwarding");
4833 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4834 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4835 ssh2_pkt_adduint32(mainchan
->remoteid
);
4836 ssh2_pkt_addstring("x11-req");
4837 ssh2_pkt_addbool(1); /* want reply */
4838 ssh2_pkt_addbool(0); /* many connections */
4839 ssh2_pkt_addstring(proto
);
4840 ssh2_pkt_addstring(data
);
4841 ssh2_pkt_adduint32(0); /* screen number */
4845 crWaitUntilV(ispkt
);
4846 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4847 unsigned i
= ssh2_pkt_getuint32();
4848 struct ssh_channel
*c
;
4849 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4851 continue; /* nonexistent channel */
4852 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4854 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4856 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4857 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4858 bombout(("Unexpected response to X11 forwarding request:"
4859 " packet type %d", pktin
.type
));
4862 logevent("X11 forwarding refused");
4864 logevent("X11 forwarding enabled");
4865 ssh_X11_fwd_enabled
= TRUE
;
4870 * Enable port forwardings.
4873 static char *e
; /* preserve across crReturn */
4876 int sport
,dport
,sserv
,dserv
;
4877 char sports
[256], dports
[256], host
[256];
4881 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4882 /* Add port forwardings. */
4887 while (*e
&& *e
!= '\t')
4893 while (*e
&& *e
!= ':')
4903 dport
= atoi(dports
);
4907 se
= getservbyname(dports
, NULL
);
4909 dport
= ntohs(se
->s_port
);
4912 "Service lookup failed for destination port \"%s\"",
4917 sport
= atoi(sports
);
4921 se
= getservbyname(sports
, NULL
);
4923 sport
= ntohs(se
->s_port
);
4926 "Service lookup failed for source port \"%s\"",
4931 if (sport
&& dport
) {
4933 pfd_addforward(host
, dport
, sport
);
4934 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
4935 " %s:%.*s%.*s%d%.*s",
4936 sserv ?
strlen(sports
) : 0, sports
,
4937 sserv
, "(", sport
, sserv
, ")",
4939 dserv ?
strlen(dports
) : 0, dports
,
4940 dserv
, "(", dport
, dserv
, ")");
4943 struct ssh_rportfwd
*pf
;
4944 pf
= smalloc(sizeof(*pf
));
4945 strcpy(pf
->dhost
, host
);
4948 if (add234(ssh_rportfwds
, pf
) != pf
) {
4950 "Duplicate remote port forwarding to %s:%d",
4955 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
4956 " forward to %s:%.*s%.*s%d%.*s",
4957 sserv ?
strlen(sports
) : 0, sports
,
4958 sserv
, "(", sport
, sserv
, ")",
4960 dserv ?
strlen(dports
) : 0, dports
,
4961 dserv
, "(", dport
, dserv
, ")");
4963 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4964 ssh2_pkt_addstring("tcpip-forward");
4965 ssh2_pkt_addbool(1);/* want reply */
4966 if (cfg
.rport_acceptall
)
4967 ssh2_pkt_addstring("0.0.0.0");
4969 ssh2_pkt_addstring("127.0.0.1");
4970 ssh2_pkt_adduint32(sport
);
4974 crWaitUntilV(ispkt
);
4975 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4976 unsigned i
= ssh2_pkt_getuint32();
4977 struct ssh_channel
*c
;
4978 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4980 continue;/* nonexistent channel */
4981 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4983 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4985 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4986 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4987 bombout(("Unexpected response to port "
4988 "forwarding request: packet type %d",
4992 logevent("Server refused this port forwarding");
4994 logevent("Remote port forwarding enabled");
5003 * Potentially enable agent forwarding.
5005 if (cfg
.agentfwd
&& agent_exists()) {
5006 logevent("Requesting OpenSSH-style agent forwarding");
5007 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5008 ssh2_pkt_adduint32(mainchan
->remoteid
);
5009 ssh2_pkt_addstring("auth-agent-req@openssh.com");
5010 ssh2_pkt_addbool(1); /* want reply */
5014 crWaitUntilV(ispkt
);
5015 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5016 unsigned i
= ssh2_pkt_getuint32();
5017 struct ssh_channel
*c
;
5018 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5020 continue; /* nonexistent channel */
5021 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5023 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5025 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5026 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5027 bombout(("Unexpected response to agent forwarding request:"
5028 " packet type %d", pktin
.type
));
5031 logevent("Agent forwarding refused");
5033 logevent("Agent forwarding enabled");
5034 ssh_agentfwd_enabled
= TRUE
;
5039 * Now allocate a pty for the session.
5042 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5043 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
5044 ssh2_pkt_addstring("pty-req");
5045 ssh2_pkt_addbool(1); /* want reply */
5046 ssh2_pkt_addstring(cfg
.termtype
);
5047 ssh2_pkt_adduint32(cols
);
5048 ssh2_pkt_adduint32(rows
);
5049 ssh2_pkt_adduint32(0); /* pixel width */
5050 ssh2_pkt_adduint32(0); /* pixel height */
5051 ssh2_pkt_addstring_start();
5052 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
5054 ssh_state
= SSH_STATE_INTERMED
;
5057 crWaitUntilV(ispkt
);
5058 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5059 unsigned i
= ssh2_pkt_getuint32();
5060 struct ssh_channel
*c
;
5061 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5063 continue; /* nonexistent channel */
5064 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5066 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5068 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5069 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5070 bombout(("Unexpected response to pty request:"
5071 " packet type %d", pktin
.type
));
5074 c_write_str("Server refused to allocate pty\r\n");
5075 ssh_editing
= ssh_echoing
= 1;
5077 logevent("Allocated pty");
5080 ssh_editing
= ssh_echoing
= 1;
5084 * Start a shell or a remote command. We may have to attempt
5085 * this twice if the config data has provided a second choice
5092 if (ssh_fallback_cmd
) {
5093 subsys
= cfg
.ssh_subsys2
;
5094 cmd
= cfg
.remote_cmd_ptr2
;
5096 subsys
= cfg
.ssh_subsys
;
5097 cmd
= cfg
.remote_cmd_ptr
;
5100 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5101 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
5103 ssh2_pkt_addstring("subsystem");
5104 ssh2_pkt_addbool(1); /* want reply */
5105 ssh2_pkt_addstring(cmd
);
5107 ssh2_pkt_addstring("exec");
5108 ssh2_pkt_addbool(1); /* want reply */
5109 ssh2_pkt_addstring(cmd
);
5111 ssh2_pkt_addstring("shell");
5112 ssh2_pkt_addbool(1); /* want reply */
5116 crWaitUntilV(ispkt
);
5117 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5118 unsigned i
= ssh2_pkt_getuint32();
5119 struct ssh_channel
*c
;
5120 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5122 continue; /* nonexistent channel */
5123 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5125 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5126 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5127 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5128 bombout(("Unexpected response to shell/command request:"
5129 " packet type %d", pktin
.type
));
5133 * We failed to start the command. If this is the
5134 * fallback command, we really are finished; if it's
5135 * not, and if the fallback command exists, try falling
5136 * back to it before complaining.
5138 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
5139 logevent("Primary command failed; attempting fallback");
5140 ssh_fallback_cmd
= TRUE
;
5143 bombout(("Server refused to start a shell/command"));
5146 logevent("Started a shell/command");
5151 ssh_state
= SSH_STATE_SESSION
;
5155 ssh_special(TS_EOF
);
5160 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
5163 static int try_send
;
5167 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5168 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5171 unsigned i
= ssh2_pkt_getuint32();
5172 struct ssh_channel
*c
;
5173 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5175 continue; /* nonexistent channel */
5176 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5177 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
5178 continue; /* extended but not stderr */
5179 ssh2_pkt_getstring(&data
, &length
);
5182 c
->v
.v2
.locwindow
-= length
;
5184 case CHAN_MAINSESSION
:
5186 from_backend(pktin
.type
==
5187 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5191 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5194 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5197 while (length
> 0) {
5198 if (c
->u
.a
.lensofar
< 4) {
5199 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5200 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5204 c
->u
.a
.lensofar
+= l
;
5206 if (c
->u
.a
.lensofar
== 4) {
5208 4 + GET_32BIT(c
->u
.a
.msglen
);
5209 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5210 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5212 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5214 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5216 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5220 c
->u
.a
.lensofar
+= l
;
5222 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5223 void *reply
, *sentreply
;
5225 agent_query(c
->u
.a
.message
,
5226 c
->u
.a
.totallen
, &reply
,
5231 /* Fake SSH_AGENT_FAILURE. */
5232 sentreply
= "\0\0\0\1\5";
5235 ssh2_add_channel_data(c
, sentreply
,
5240 sfree(c
->u
.a
.message
);
5241 c
->u
.a
.lensofar
= 0;
5248 * If we are not buffering too much data,
5249 * enlarge the window again at the remote side.
5251 if (bufsize
< OUR_V2_WINSIZE
)
5252 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5254 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
5255 ssh_state
= SSH_STATE_CLOSED
;
5256 logevent("Received disconnect message");
5258 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5259 unsigned i
= ssh2_pkt_getuint32();
5260 struct ssh_channel
*c
;
5262 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5264 continue; /* nonexistent channel */
5266 if (c
->type
== CHAN_X11
) {
5268 * Remote EOF on an X11 channel means we should
5269 * wrap up and close the channel ourselves.
5271 x11_close(c
->u
.x11
.s
);
5273 } else if (c
->type
== CHAN_AGENT
) {
5275 } else if (c
->type
== CHAN_SOCKDATA
) {
5276 pfd_close(c
->u
.pfd
.s
);
5279 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5280 unsigned i
= ssh2_pkt_getuint32();
5281 struct ssh_channel
*c
;
5283 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5285 continue; /* nonexistent channel */
5286 /* Do pre-close processing on the channel. */
5288 case CHAN_MAINSESSION
:
5289 break; /* nothing to see here, move along */
5291 if (c
->u
.x11
.s
!= NULL
)
5292 x11_close(c
->u
.x11
.s
);
5299 if (c
->u
.pfd
.s
!= NULL
)
5300 pfd_close(c
->u
.pfd
.s
);
5304 if (c
->closes
== 0) {
5305 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5306 ssh2_pkt_adduint32(c
->remoteid
);
5309 del234(ssh_channels
, c
);
5310 bufchain_clear(&c
->v
.v2
.outbuffer
);
5314 * See if that was the last channel left open.
5316 if (count234(ssh_channels
) == 0) {
5319 * We used to send SSH_MSG_DISCONNECT here,
5320 * because I'd believed that _every_ conforming
5321 * SSH2 connection had to end with a disconnect
5322 * being sent by at least one side; apparently
5323 * I was wrong and it's perfectly OK to
5324 * unceremoniously slam the connection shut
5325 * when you're done, and indeed OpenSSH feels
5326 * this is more polite than sending a
5327 * DISCONNECT. So now we don't.
5329 logevent("All channels closed. Disconnecting");
5330 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5331 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5332 ssh2_pkt_addstring("All open channels closed");
5333 ssh2_pkt_addstring("en"); /* language tag */
5336 ssh_state
= SSH_STATE_CLOSED
;
5339 continue; /* remote sends close; ignore (FIXME) */
5340 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5341 unsigned i
= ssh2_pkt_getuint32();
5342 struct ssh_channel
*c
;
5343 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5345 continue; /* nonexistent channel */
5346 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
5348 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5349 unsigned i
= ssh2_pkt_getuint32();
5350 struct ssh_channel
*c
;
5351 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5353 continue; /* nonexistent channel */
5354 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5355 continue; /* dunno why they're confirming this */
5356 c
->remoteid
= ssh2_pkt_getuint32();
5357 c
->type
= CHAN_SOCKDATA
;
5358 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
5359 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
5360 bufchain_init(&c
->v
.v2
.outbuffer
);
5362 pfd_confirm(c
->u
.pfd
.s
);
5365 * We have a pending close on this channel,
5366 * which we decided on before the server acked
5367 * the channel open. So now we know the
5368 * remoteid, we can close it again.
5370 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
5371 ssh2_pkt_adduint32(c
->remoteid
);
5374 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5375 unsigned i
= ssh2_pkt_getuint32();
5376 struct ssh_channel
*c
;
5377 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
5379 continue; /* nonexistent channel */
5380 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5381 continue; /* dunno why they're failing this */
5383 logevent("Forwarded connection refused by server");
5385 pfd_close(c
->u
.pfd
.s
);
5387 del234(ssh_channels
, c
);
5389 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5392 int typelen
, want_reply
;
5393 struct ssh_channel
*c
;
5395 localid
= ssh2_pkt_getuint32();
5396 ssh2_pkt_getstring(&type
, &typelen
);
5397 want_reply
= ssh2_pkt_getbool();
5400 * First, check that the channel exists. Otherwise,
5401 * we can instantly disconnect with a rude message.
5403 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
5406 sprintf(buf
, "Received channel request for nonexistent"
5407 " channel %d", localid
);
5409 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
5410 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
5411 ssh2_pkt_addstring(buf
);
5412 ssh2_pkt_addstring("en"); /* language tag */
5414 connection_fatal("%s", buf
);
5415 ssh_state
= SSH_STATE_CLOSED
;
5420 * Having got the channel number, we now look at
5421 * the request type string to see if it's something
5424 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5426 /* We recognise "exit-status" on the primary channel. */
5428 ssh_exitcode
= ssh2_pkt_getuint32();
5429 sprintf(buf
, "Server sent command exit status %d",
5433 ssh2_pkt_init(SSH2_MSG_CHANNEL_SUCCESS
);
5434 ssh2_pkt_adduint32(c
->remoteid
);
5439 * This is a channel request we don't know
5440 * about, so we now either ignore the request
5441 * or respond with CHANNEL_FAILURE, depending
5445 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
5446 ssh2_pkt_adduint32(c
->remoteid
);
5450 } else if (pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5452 int typelen
, want_reply
;
5454 ssh2_pkt_getstring(&type
, &typelen
);
5455 want_reply
= ssh2_pkt_getbool();
5458 * We currently don't support any global requests
5459 * at all, so we either ignore the request or
5460 * respond with REQUEST_FAILURE, depending on
5464 ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE
);
5467 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5471 struct ssh_channel
*c
;
5472 unsigned remid
, winsize
, pktsize
;
5473 ssh2_pkt_getstring(&type
, &typelen
);
5474 c
= smalloc(sizeof(struct ssh_channel
));
5476 remid
= ssh2_pkt_getuint32();
5477 winsize
= ssh2_pkt_getuint32();
5478 pktsize
= ssh2_pkt_getuint32();
5480 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5481 if (!ssh_X11_fwd_enabled
)
5482 error
= "X11 forwarding is not enabled";
5483 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
5485 error
= "Unable to open an X11 connection";
5489 } else if (typelen
== 15 &&
5490 !memcmp(type
, "forwarded-tcpip", 15)) {
5491 struct ssh_rportfwd pf
, *realpf
;
5494 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
5495 pf
.sport
= ssh2_pkt_getuint32();
5496 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
5497 if (realpf
== NULL
) {
5498 error
= "Remote port is not recognised";
5500 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5503 sprintf(buf
, "Received remote port open request for %s:%d",
5504 realpf
->dhost
, realpf
->dport
);
5507 sprintf(buf
, "Port open failed: %s", e
);
5509 error
= "Port open failed";
5511 logevent("Forwarded port opened successfully");
5512 c
->type
= CHAN_SOCKDATA
;
5515 } else if (typelen
== 22 &&
5516 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5517 if (!ssh_agentfwd_enabled
)
5518 error
= "Agent forwarding is not enabled";
5520 c
->type
= CHAN_AGENT
; /* identify channel type */
5521 c
->u
.a
.lensofar
= 0;
5524 error
= "Unsupported channel type requested";
5527 c
->remoteid
= remid
;
5529 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5530 ssh2_pkt_adduint32(c
->remoteid
);
5531 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5532 ssh2_pkt_addstring(error
);
5533 ssh2_pkt_addstring("en"); /* language tag */
5537 c
->localid
= alloc_channel_id();
5539 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5540 c
->v
.v2
.remwindow
= winsize
;
5541 c
->v
.v2
.remmaxpkt
= pktsize
;
5542 bufchain_init(&c
->v
.v2
.outbuffer
);
5543 add234(ssh_channels
, c
);
5544 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5545 ssh2_pkt_adduint32(c
->remoteid
);
5546 ssh2_pkt_adduint32(c
->localid
);
5547 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5548 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5552 bombout(("Strange packet received: type %d", pktin
.type
));
5557 * We have spare data. Add it to the channel buffer.
5559 ssh2_add_channel_data(mainchan
, in
, inlen
);
5564 struct ssh_channel
*c
;
5566 * Try to send data on all channels if we can.
5568 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5569 int bufsize
= ssh2_try_send(c
);
5572 case CHAN_MAINSESSION
:
5573 /* stdin need not receive an unthrottle
5574 * notification since it will be polled */
5577 x11_unthrottle(c
->u
.x11
.s
);
5580 /* agent sockets are request/response and need no
5581 * buffer management */
5584 pfd_unthrottle(c
->u
.pfd
.s
);
5596 * Handle the top-level SSH2 protocol.
5598 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5600 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5602 do_ssh2_authconn(in
, inlen
, ispkt
);
5606 * Called to set up the connection.
5608 * Returns an error message, or NULL on success.
5610 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5615 if (crypto_startup() == 0)
5616 return "Microsoft high encryption pack not installed!";
5622 ssh1_throttle_count
= 0;
5623 ssh_overall_bufsize
= 0;
5624 ssh_fallback_cmd
= 0;
5626 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5634 * Called to send data down the Telnet connection.
5636 static int ssh_send(char *buf
, int len
)
5638 if (s
== NULL
|| ssh_protocol
== NULL
)
5641 ssh_protocol(buf
, len
, 0);
5643 return ssh_sendbuffer();
5647 * Called to query the current amount of buffered stdin data.
5649 static int ssh_sendbuffer(void)
5653 if (s
== NULL
|| ssh_protocol
== NULL
)
5657 * If the SSH socket itself has backed up, add the total backup
5658 * size on that to any individual buffer on the stdin channel.
5661 if (ssh_throttled_all
)
5662 override_value
= ssh_overall_bufsize
;
5664 if (ssh_version
== 1) {
5665 return override_value
;
5666 } else if (ssh_version
== 2) {
5667 if (!mainchan
|| mainchan
->closes
> 0)
5668 return override_value
;
5670 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5677 * Called to set the size of the window from SSH's POV.
5679 static void ssh_size(void)
5681 switch (ssh_state
) {
5682 case SSH_STATE_BEFORE_SIZE
:
5683 case SSH_STATE_PREPACKET
:
5684 case SSH_STATE_CLOSED
:
5685 break; /* do nothing */
5686 case SSH_STATE_INTERMED
:
5687 size_needed
= TRUE
; /* buffer for later */
5689 case SSH_STATE_SESSION
:
5691 if (ssh_version
== 1) {
5692 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5693 PKT_INT
, rows
, PKT_INT
, cols
,
5694 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5696 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5697 ssh2_pkt_adduint32(mainchan
->remoteid
);
5698 ssh2_pkt_addstring("window-change");
5699 ssh2_pkt_addbool(0);
5700 ssh2_pkt_adduint32(cols
);
5701 ssh2_pkt_adduint32(rows
);
5702 ssh2_pkt_adduint32(0);
5703 ssh2_pkt_adduint32(0);
5712 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5713 * can send an EOF and collect resulting output (e.g. `plink
5716 static void ssh_special(Telnet_Special code
)
5718 if (code
== TS_EOF
) {
5719 if (ssh_state
!= SSH_STATE_SESSION
) {
5721 * Buffer the EOF in case we are pre-SESSION, so we can
5722 * send it as soon as we reach SESSION.
5728 if (ssh_version
== 1) {
5729 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5731 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5732 ssh2_pkt_adduint32(mainchan
->remoteid
);
5735 logevent("Sent EOF message");
5736 } else if (code
== TS_PING
) {
5737 if (ssh_state
== SSH_STATE_CLOSED
5738 || ssh_state
== SSH_STATE_PREPACKET
) return;
5739 if (ssh_version
== 1) {
5740 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5742 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5743 ssh2_pkt_addstring_start();
5751 void *new_sock_channel(Socket s
)
5753 struct ssh_channel
*c
;
5754 c
= smalloc(sizeof(struct ssh_channel
));
5757 c
->remoteid
= -1; /* to be set when open confirmed */
5758 c
->localid
= alloc_channel_id();
5760 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5762 add234(ssh_channels
, c
);
5768 * This is called when stdout/stderr (the entity to which
5769 * from_backend sends data) manages to clear some backlog.
5771 void ssh_unthrottle(int bufsize
)
5773 if (ssh_version
== 1) {
5774 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5775 ssh1_stdout_throttling
= 0;
5779 if (mainchan
&& mainchan
->closes
== 0)
5780 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5784 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5786 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5789 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5792 if (ssh_version
== 1) {
5793 send_packet(SSH1_MSG_PORT_OPEN
,
5794 PKT_INT
, c
->localid
,
5797 //PKT_STR, <org:orgport>,
5800 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5801 ssh2_pkt_addstring("direct-tcpip");
5802 ssh2_pkt_adduint32(c
->localid
);
5803 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5804 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5805 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5806 ssh2_pkt_addstring(hostname
);
5807 ssh2_pkt_adduint32(port
);
5809 * We make up values for the originator data; partly it's
5810 * too much hassle to keep track, and partly I'm not
5811 * convinced the server should be told details like that
5812 * about my local network configuration.
5814 ssh2_pkt_addstring("client-side-connection");
5815 ssh2_pkt_adduint32(0);
5821 static Socket
ssh_socket(void)
5826 static int ssh_sendok(void)
5831 static int ssh_ldisc(int option
)
5833 if (option
== LD_ECHO
)
5835 if (option
== LD_EDIT
)
5840 static int ssh_return_exitcode(void)
5842 return ssh_exitcode
;
5845 Backend ssh_backend
= {
5852 ssh_return_exitcode
,