18 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
19 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
20 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
21 #define SSH1_CMSG_USER 4 /* 0x4 */
22 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
23 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
24 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
25 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
26 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
27 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
28 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
29 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
30 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
31 #define SSH1_SMSG_FAILURE 15 /* 0xf */
32 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
33 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
34 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
35 #define SSH1_CMSG_EOF 19 /* 0x13 */
36 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
37 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
38 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
39 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
40 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
41 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
42 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
43 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
44 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
45 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
46 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
47 #define SSH1_MSG_IGNORE 32 /* 0x20 */
48 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
49 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
50 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
51 #define SSH1_MSG_DEBUG 36 /* 0x24 */
52 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
53 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
54 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
55 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
56 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
57 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
58 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
60 #define SSH1_AUTH_TIS 5 /* 0x5 */
61 #define SSH1_AUTH_CCARD 16 /* 0x10 */
63 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
64 /* Mask for protoflags we will echo back to server if seen */
65 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
67 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
68 #define SSH2_MSG_IGNORE 2 /* 0x2 */
69 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
70 #define SSH2_MSG_DEBUG 4 /* 0x4 */
71 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
72 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
73 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
74 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
75 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
76 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
77 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
78 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
79 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
80 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
81 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
82 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
83 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
84 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
85 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
88 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
89 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
90 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
91 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
92 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
93 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
94 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
95 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
96 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
97 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
98 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
99 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
100 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
101 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
102 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
105 * Packet type contexts, so that ssh2_pkt_type can correctly decode
106 * the ambiguous type numbers back into the correct type strings.
108 #define SSH2_PKTCTX_DHGROUP1 0x0001
109 #define SSH2_PKTCTX_DHGEX 0x0002
110 #define SSH2_PKTCTX_PUBLICKEY 0x0010
111 #define SSH2_PKTCTX_PASSWORD 0x0020
112 #define SSH2_PKTCTX_KBDINTER 0x0040
113 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons
[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_DH_GEX 64
168 #define translate(x) if (type == x) return #x
169 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
170 char *ssh1_pkt_type(int type
)
172 translate(SSH1_MSG_DISCONNECT
);
173 translate(SSH1_SMSG_PUBLIC_KEY
);
174 translate(SSH1_CMSG_SESSION_KEY
);
175 translate(SSH1_CMSG_USER
);
176 translate(SSH1_CMSG_AUTH_RSA
);
177 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE
);
178 translate(SSH1_CMSG_AUTH_RSA_RESPONSE
);
179 translate(SSH1_CMSG_AUTH_PASSWORD
);
180 translate(SSH1_CMSG_REQUEST_PTY
);
181 translate(SSH1_CMSG_WINDOW_SIZE
);
182 translate(SSH1_CMSG_EXEC_SHELL
);
183 translate(SSH1_CMSG_EXEC_CMD
);
184 translate(SSH1_SMSG_SUCCESS
);
185 translate(SSH1_SMSG_FAILURE
);
186 translate(SSH1_CMSG_STDIN_DATA
);
187 translate(SSH1_SMSG_STDOUT_DATA
);
188 translate(SSH1_SMSG_STDERR_DATA
);
189 translate(SSH1_CMSG_EOF
);
190 translate(SSH1_SMSG_EXIT_STATUS
);
191 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
);
192 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE
);
193 translate(SSH1_MSG_CHANNEL_DATA
);
194 translate(SSH1_MSG_CHANNEL_CLOSE
);
195 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
);
196 translate(SSH1_SMSG_X11_OPEN
);
197 translate(SSH1_CMSG_PORT_FORWARD_REQUEST
);
198 translate(SSH1_MSG_PORT_OPEN
);
199 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING
);
200 translate(SSH1_SMSG_AGENT_OPEN
);
201 translate(SSH1_MSG_IGNORE
);
202 translate(SSH1_CMSG_EXIT_CONFIRMATION
);
203 translate(SSH1_CMSG_X11_REQUEST_FORWARDING
);
204 translate(SSH1_CMSG_AUTH_RHOSTS_RSA
);
205 translate(SSH1_MSG_DEBUG
);
206 translate(SSH1_CMSG_REQUEST_COMPRESSION
);
207 translate(SSH1_CMSG_AUTH_TIS
);
208 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE
);
209 translate(SSH1_CMSG_AUTH_TIS_RESPONSE
);
210 translate(SSH1_CMSG_AUTH_CCARD
);
211 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE
);
212 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE
);
215 char *ssh2_pkt_type(int pkt_ctx
, int type
)
217 translate(SSH2_MSG_DISCONNECT
);
218 translate(SSH2_MSG_IGNORE
);
219 translate(SSH2_MSG_UNIMPLEMENTED
);
220 translate(SSH2_MSG_DEBUG
);
221 translate(SSH2_MSG_SERVICE_REQUEST
);
222 translate(SSH2_MSG_SERVICE_ACCEPT
);
223 translate(SSH2_MSG_KEXINIT
);
224 translate(SSH2_MSG_NEWKEYS
);
225 translatec(SSH2_MSG_KEXDH_INIT
, SSH2_PKTCTX_DHGROUP1
);
226 translatec(SSH2_MSG_KEXDH_REPLY
, SSH2_PKTCTX_DHGROUP1
);
227 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST
, SSH2_PKTCTX_DHGEX
);
228 translatec(SSH2_MSG_KEX_DH_GEX_GROUP
, SSH2_PKTCTX_DHGEX
);
229 translatec(SSH2_MSG_KEX_DH_GEX_INIT
, SSH2_PKTCTX_DHGEX
);
230 translatec(SSH2_MSG_KEX_DH_GEX_REPLY
, SSH2_PKTCTX_DHGEX
);
231 translate(SSH2_MSG_USERAUTH_REQUEST
);
232 translate(SSH2_MSG_USERAUTH_FAILURE
);
233 translate(SSH2_MSG_USERAUTH_SUCCESS
);
234 translate(SSH2_MSG_USERAUTH_BANNER
);
235 translatec(SSH2_MSG_USERAUTH_PK_OK
, SSH2_PKTCTX_PUBLICKEY
);
236 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ
, SSH2_PKTCTX_PASSWORD
);
237 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST
, SSH2_PKTCTX_KBDINTER
);
238 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE
, SSH2_PKTCTX_KBDINTER
);
239 translate(SSH2_MSG_GLOBAL_REQUEST
);
240 translate(SSH2_MSG_REQUEST_SUCCESS
);
241 translate(SSH2_MSG_REQUEST_FAILURE
);
242 translate(SSH2_MSG_CHANNEL_OPEN
);
243 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
244 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
245 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
246 translate(SSH2_MSG_CHANNEL_DATA
);
247 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA
);
248 translate(SSH2_MSG_CHANNEL_EOF
);
249 translate(SSH2_MSG_CHANNEL_CLOSE
);
250 translate(SSH2_MSG_CHANNEL_REQUEST
);
251 translate(SSH2_MSG_CHANNEL_SUCCESS
);
252 translate(SSH2_MSG_CHANNEL_FAILURE
);
258 #define GET_32BIT(cp) \
259 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
260 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
261 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
262 ((unsigned long)(unsigned char)(cp)[3]))
264 #define PUT_32BIT(cp, value) { \
265 (cp)[0] = (unsigned char)((value) >> 24); \
266 (cp)[1] = (unsigned char)((value) >> 16); \
267 (cp)[2] = (unsigned char)((value) >> 8); \
268 (cp)[3] = (unsigned char)(value); }
270 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
272 /* Coroutine mechanics for the sillier bits of the code */
273 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
276 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
278 #define crFinish(z) } *crLine = 0; return (z); }
279 #define crFinishV } *crLine = 0; return; }
280 #define crReturn(z) \
282 *crLine =__LINE__; return (z); case __LINE__:;\
286 *crLine=__LINE__; return; case __LINE__:;\
288 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
289 #define crStopV do{ *crLine = 0; return; }while(0)
290 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
291 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
293 typedef struct ssh_tag
*Ssh
;
295 extern char *x11_init(Socket
*, char *, void *, void *);
296 extern void x11_close(Socket
);
297 extern int x11_send(Socket
, char *, int);
298 extern void *x11_invent_auth(char *, int, char *, int);
299 extern void x11_unthrottle(Socket s
);
300 extern void x11_override_throttle(Socket s
, int enable
);
302 extern char *pfd_newconnect(Socket
* s
, char *hostname
, int port
, void *c
);
303 extern char *pfd_addforward(char *desthost
, int destport
, int port
,
305 extern void pfd_close(Socket s
);
306 extern int pfd_send(Socket s
, char *data
, int len
);
307 extern void pfd_confirm(Socket s
);
308 extern void pfd_unthrottle(Socket s
);
309 extern void pfd_override_throttle(Socket s
, int enable
);
311 static void ssh2_pkt_init(Ssh
, int pkt_type
);
312 static void ssh2_pkt_addbool(Ssh
, unsigned char value
);
313 static void ssh2_pkt_adduint32(Ssh
, unsigned long value
);
314 static void ssh2_pkt_addstring_start(Ssh
);
315 static void ssh2_pkt_addstring_str(Ssh
, char *data
);
316 static void ssh2_pkt_addstring_data(Ssh
, char *data
, int len
);
317 static void ssh2_pkt_addstring(Ssh
, char *data
);
318 static char *ssh2_mpint_fmt(Bignum b
, int *len
);
319 static void ssh2_pkt_addmp(Ssh
, Bignum b
);
320 static int ssh2_pkt_construct(Ssh
);
321 static void ssh2_pkt_send(Ssh
);
324 * Buffer management constants. There are several of these for
325 * various different purposes:
327 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
328 * on a local data stream before we throttle the whole SSH
329 * connection (in SSH1 only). Throttling the whole connection is
330 * pretty drastic so we set this high in the hope it won't
333 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
334 * on the SSH connection itself before we defensively throttle
335 * _all_ local data streams. This is pretty drastic too (though
336 * thankfully unlikely in SSH2 since the window mechanism should
337 * ensure that the server never has any need to throttle its end
338 * of the connection), so we set this high as well.
340 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
344 #define SSH1_BUFFER_LIMIT 32768
345 #define SSH_MAX_BACKLOG 32768
346 #define OUR_V2_WINSIZE 16384
348 const static struct ssh_kex
*kex_algs
[] = {
349 &ssh_diffiehellman_gex
,
353 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
355 static void *nullmac_make_context(void)
359 static void nullmac_free_context(void *handle
)
362 static void nullmac_key(void *handle
, unsigned char *key
)
365 static void nullmac_generate(void *handle
, unsigned char *blk
, int len
,
369 static int nullmac_verify(void *handle
, unsigned char *blk
, int len
,
374 const static struct ssh_mac ssh_mac_none
= {
375 nullmac_make_context
, nullmac_free_context
, nullmac_key
,
376 nullmac_generate
, nullmac_verify
, "none", 0
378 const static struct ssh_mac
*macs
[] = {
379 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
381 const static struct ssh_mac
*buggymacs
[] = {
382 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
385 static void *ssh_comp_none_init(void)
389 static void ssh_comp_none_cleanup(void *handle
)
392 static int ssh_comp_none_block(void *handle
, unsigned char *block
, int len
,
393 unsigned char **outblock
, int *outlen
)
397 static int ssh_comp_none_disable(void *handle
)
401 const static struct ssh_compress ssh_comp_none
= {
403 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
404 ssh_comp_none_init
, ssh_comp_none_cleanup
, ssh_comp_none_block
,
405 ssh_comp_none_disable
, NULL
407 extern const struct ssh_compress ssh_zlib
;
408 const static struct ssh_compress
*compressions
[] = {
409 &ssh_zlib
, &ssh_comp_none
412 enum { /* channel types */
417 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
421 * 2-3-4 tree storing channels.
424 Ssh ssh
; /* pointer back to main context */
425 unsigned remoteid
, localid
;
428 * In SSH1, this value contains four bits:
430 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
431 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
432 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
433 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
435 * A channel is completely finished with when all four bits are set.
439 struct ssh1_data_channel
{
442 struct ssh2_data_channel
{
444 unsigned remwindow
, remmaxpkt
;
449 struct ssh_agent_channel
{
450 unsigned char *message
;
451 unsigned char msglen
[4];
452 int lensofar
, totallen
;
454 struct ssh_x11_channel
{
457 struct ssh_pfd_channel
{
464 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
465 * 2 use this structure in different ways, reflecting SSH 2's
466 * altogether saner approach to port forwarding.
468 * In SSH 1, you arrange a remote forwarding by sending the server
469 * the remote port number, and the local destination host:port.
470 * When a connection comes in, the server sends you back that
471 * host:port pair, and you connect to it. This is a ready-made
472 * security hole if you're not on the ball: a malicious server
473 * could send you back _any_ host:port pair, so if you trustingly
474 * connect to the address it gives you then you've just opened the
475 * entire inside of your corporate network just by connecting
476 * through it to a dodgy SSH server. Hence, we must store a list of
477 * host:port pairs we _are_ trying to forward to, and reject a
478 * connection request from the server if it's not in the list.
480 * In SSH 2, each side of the connection minds its own business and
481 * doesn't send unnecessary information to the other. You arrange a
482 * remote forwarding by sending the server just the remote port
483 * number. When a connection comes in, the server tells you which
484 * of its ports was connected to; and _you_ have to remember what
485 * local host:port pair went with that port number.
487 * Hence: in SSH 1 this structure stores host:port pairs we intend
488 * to allow connections to, and is indexed by those host:port
489 * pairs. In SSH 2 it stores a mapping from source port to
490 * destination host:port pair, and is indexed by source port.
492 struct ssh_rportfwd
{
493 unsigned sport
, dport
;
506 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
507 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
508 static void ssh_size(void *handle
, int width
, int height
);
509 static void ssh_special(void *handle
, Telnet_Special
);
510 static int ssh2_try_send(struct ssh_channel
*c
);
511 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
512 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
);
513 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
514 static int ssh_sendbuffer(void *handle
);
516 struct rdpkt1_state_tag
{
517 long len
, pad
, biglen
, to_read
;
518 unsigned long realcrc
, gotcrc
;
524 struct rdpkt2_state_tag
{
525 long len
, pad
, payload
, packetlen
, maclen
;
528 unsigned long incoming_sequence
;
532 const struct plug_function_table
*fn
;
533 /* the above field _must_ be first in the structure */
535 SHA_State exhash
, exhashbase
;
542 unsigned char session_key
[32];
544 int v1_remote_protoflags
;
545 int v1_local_protoflags
;
546 int agentfwd_enabled
;
549 const struct ssh_cipher
*cipher
;
552 const struct ssh2_cipher
*cscipher
, *sccipher
;
553 void *cs_cipher_ctx
, *sc_cipher_ctx
;
554 const struct ssh_mac
*csmac
, *scmac
;
555 void *cs_mac_ctx
, *sc_mac_ctx
;
556 const struct ssh_compress
*cscomp
, *sccomp
;
557 void *cs_comp_ctx
, *sc_comp_ctx
;
558 const struct ssh_kex
*kex
;
559 const struct ssh_signkey
*hostkey
;
560 unsigned char v2_session_id
[20];
566 int echoing
, editing
;
570 int term_width
, term_height
;
572 tree234
*channels
; /* indexed by local id */
573 struct ssh_channel
*mainchan
; /* primary session channel */
580 SSH_STATE_BEFORE_SIZE
,
586 int size_needed
, eof_needed
;
589 struct Packet pktout
;
590 unsigned char *deferred_send_data
;
591 int deferred_len
, deferred_size
;
594 * Gross hack: pscp will try to start SFTP but fall back to
595 * scp1 if that fails. This variable is the means by which
596 * scp.c can reach into the SSH code and find out which one it
602 * Used for username and password input.
604 char *userpass_input_buffer
;
605 int userpass_input_buflen
;
606 int userpass_input_bufpos
;
607 int userpass_input_echo
;
609 char *portfwd_strptr
;
615 int v1_throttle_count
;
618 int v1_stdout_throttling
;
619 int v2_outgoing_sequence
;
621 int ssh1_rdpkt_crstate
;
622 int ssh2_rdpkt_crstate
;
623 int do_ssh_init_crstate
;
624 int ssh_gotdata_crstate
;
625 int ssh1_protocol_crstate
;
626 int do_ssh1_login_crstate
;
627 int do_ssh2_transport_crstate
;
628 int do_ssh2_authconn_crstate
;
630 void *do_ssh_init_state
;
631 void *do_ssh1_login_state
;
632 void *do_ssh2_transport_state
;
633 void *do_ssh2_authconn_state
;
635 struct rdpkt1_state_tag rdpkt1_state
;
636 struct rdpkt2_state_tag rdpkt2_state
;
638 void (*protocol
) (Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
);
639 int (*s_rdpkt
) (Ssh ssh
, unsigned char **data
, int *datalen
);
642 #define logevent(s) { logevent(ssh->frontend, s); \
643 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
644 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
646 /* logevent, only printf-formatted. */
647 void logeventf(Ssh ssh
, char *fmt
, ...)
653 vsprintf(stuff
, fmt
, ap
);
658 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
659 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
660 logeventf msg, connection_fatal msg )
662 static int ssh_channelcmp(void *av
, void *bv
)
664 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
665 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
666 if (a
->localid
< b
->localid
)
668 if (a
->localid
> b
->localid
)
672 static int ssh_channelfind(void *av
, void *bv
)
674 unsigned *a
= (unsigned *) av
;
675 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
683 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
685 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
686 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
688 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
689 return i
< 0 ?
-1 : +1;
690 if (a
->dport
> b
->dport
)
692 if (a
->dport
< b
->dport
)
697 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
699 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
700 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
702 if (a
->sport
> b
->sport
)
704 if (a
->sport
< b
->sport
)
709 static int alloc_channel_id(Ssh ssh
)
711 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
712 unsigned low
, high
, mid
;
714 struct ssh_channel
*c
;
717 * First-fit allocation of channel numbers: always pick the
718 * lowest unused one. To do this, binary-search using the
719 * counted B-tree to find the largest channel ID which is in a
720 * contiguous sequence from the beginning. (Precisely
721 * everything in that sequence must have ID equal to its tree
722 * index plus CHANNEL_NUMBER_OFFSET.)
724 tsize
= count234(ssh
->channels
);
728 while (high
- low
> 1) {
729 mid
= (high
+ low
) / 2;
730 c
= index234(ssh
->channels
, mid
);
731 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
732 low
= mid
; /* this one is fine */
734 high
= mid
; /* this one is past it */
737 * Now low points to either -1, or the tree index of the
738 * largest ID in the initial sequence.
741 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
742 assert(NULL
== find234(ssh
->channels
, &i
, ssh_channelfind
));
744 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
747 static void c_write(Ssh ssh
, char *buf
, int len
)
749 if ((flags
& FLAG_STDERR
)) {
751 for (i
= 0; i
< len
; i
++)
753 fputc(buf
[i
], stderr
);
756 from_backend(ssh
->frontend
, 1, buf
, len
);
759 static void c_write_untrusted(Ssh ssh
, char *buf
, int len
)
762 for (i
= 0; i
< len
; i
++) {
764 c_write(ssh
, "\r\n", 2);
765 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
766 c_write(ssh
, buf
+ i
, 1);
770 static void c_write_str(Ssh ssh
, char *buf
)
772 c_write(ssh
, buf
, strlen(buf
));
776 * Collect incoming data in the incoming packet buffer.
777 * Decipher and verify the packet when it is completely read.
778 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
779 * Update the *data and *datalen variables.
780 * Return the additional nr of bytes needed, or 0 when
781 * a complete packet is available.
783 static int ssh1_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
785 struct rdpkt1_state_tag
*st
= &ssh
->rdpkt1_state
;
787 crBegin(ssh
->ssh1_rdpkt_crstate
);
792 ssh
->pktin
.length
= 0;
794 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
795 while ((*datalen
) == 0)
797 st
->len
= (st
->len
<< 8) + **data
;
798 (*data
)++, (*datalen
)--;
801 st
->pad
= 8 - (st
->len
% 8);
802 st
->biglen
= st
->len
+ st
->pad
;
803 ssh
->pktin
.length
= st
->len
- 5;
805 if (ssh
->pktin
.maxlen
< st
->biglen
) {
806 ssh
->pktin
.maxlen
= st
->biglen
;
807 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->biglen
+ APIEXTRA
);
810 st
->to_read
= st
->biglen
;
811 st
->p
= ssh
->pktin
.data
;
812 while (st
->to_read
> 0) {
813 st
->chunk
= st
->to_read
;
814 while ((*datalen
) == 0)
815 crReturn(st
->to_read
);
816 if (st
->chunk
> (*datalen
))
817 st
->chunk
= (*datalen
);
818 memcpy(st
->p
, *data
, st
->chunk
);
820 *datalen
-= st
->chunk
;
822 st
->to_read
-= st
->chunk
;
825 if (ssh
->cipher
&& detect_attack(ssh
->crcda_ctx
, ssh
->pktin
.data
,
827 bombout((ssh
,"Network attack (CRC compensation) detected!"));
832 ssh
->cipher
->decrypt(ssh
->v1_cipher_ctx
, ssh
->pktin
.data
, st
->biglen
);
834 st
->realcrc
= crc32(ssh
->pktin
.data
, st
->biglen
- 4);
835 st
->gotcrc
= GET_32BIT(ssh
->pktin
.data
+ st
->biglen
- 4);
836 if (st
->gotcrc
!= st
->realcrc
) {
837 bombout((ssh
,"Incorrect CRC received on packet"));
841 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
843 if (ssh
->v1_compressing
) {
844 unsigned char *decompblk
;
846 zlib_decompress_block(ssh
->sc_comp_ctx
,
847 ssh
->pktin
.body
- 1, ssh
->pktin
.length
+ 1,
848 &decompblk
, &decomplen
);
850 if (ssh
->pktin
.maxlen
< st
->pad
+ decomplen
) {
851 ssh
->pktin
.maxlen
= st
->pad
+ decomplen
;
852 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
853 ssh
->pktin
.maxlen
+ APIEXTRA
);
854 ssh
->pktin
.body
= ssh
->pktin
.data
+ st
->pad
+ 1;
857 memcpy(ssh
->pktin
.body
- 1, decompblk
, decomplen
);
859 ssh
->pktin
.length
= decomplen
- 1;
862 ssh
->pktin
.type
= ssh
->pktin
.body
[-1];
865 log_packet(ssh
->logctx
,
866 PKT_INCOMING
, ssh
->pktin
.type
,
867 ssh1_pkt_type(ssh
->pktin
.type
),
868 ssh
->pktin
.body
, ssh
->pktin
.length
);
870 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
871 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
||
872 ssh
->pktin
.type
== SSH1_MSG_DEBUG
||
873 ssh
->pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
874 ssh
->pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
875 long stringlen
= GET_32BIT(ssh
->pktin
.body
);
876 if (stringlen
+ 4 != ssh
->pktin
.length
) {
877 bombout((ssh
,"Received data packet with bogus string length"));
882 if (ssh
->pktin
.type
== SSH1_MSG_DEBUG
) {
883 /* log debug message */
885 int stringlen
= GET_32BIT(ssh
->pktin
.body
);
886 strcpy(buf
, "Remote debug message: ");
889 memcpy(buf
+ 8, ssh
->pktin
.body
+ 4, stringlen
);
890 buf
[8 + stringlen
] = '\0';
893 } else if (ssh
->pktin
.type
== SSH1_MSG_IGNORE
) {
898 if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
899 /* log reason code in disconnect message */
901 unsigned msglen
= GET_32BIT(ssh
->pktin
.body
);
903 strcpy(buf
, "Remote sent disconnect: ");
904 nowlen
= strlen(buf
);
905 if (msglen
> sizeof(buf
) - nowlen
- 1)
906 msglen
= sizeof(buf
) - nowlen
- 1;
907 memcpy(buf
+ nowlen
, ssh
->pktin
.body
+ 4, msglen
);
908 buf
[nowlen
+ msglen
] = '\0';
909 /* logevent(buf); (this is now done within the bombout macro) */
910 bombout((ssh
,"Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
917 static int ssh2_rdpkt(Ssh ssh
, unsigned char **data
, int *datalen
)
919 struct rdpkt2_state_tag
*st
= &ssh
->rdpkt2_state
;
921 crBegin(ssh
->ssh2_rdpkt_crstate
);
925 ssh
->pktin
.length
= 0;
927 st
->cipherblk
= ssh
->sccipher
->blksize
;
930 if (st
->cipherblk
< 8)
933 if (ssh
->pktin
.maxlen
< st
->cipherblk
) {
934 ssh
->pktin
.maxlen
= st
->cipherblk
;
935 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
, st
->cipherblk
+ APIEXTRA
);
939 * Acquire and decrypt the first block of the packet. This will
940 * contain the length and padding details.
942 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
943 while ((*datalen
) == 0)
944 crReturn(st
->cipherblk
- st
->i
);
945 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
950 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
951 ssh
->pktin
.data
, st
->cipherblk
);
954 * Now get the length and padding figures.
956 st
->len
= GET_32BIT(ssh
->pktin
.data
);
957 st
->pad
= ssh
->pktin
.data
[4];
960 * _Completely_ silly lengths should be stomped on before they
961 * do us any more damage.
963 if (st
->len
< 0 || st
->pad
< 0 || st
->len
+ st
->pad
< 0) {
964 bombout((ssh
,"Incoming packet was garbled on decryption"));
969 * This enables us to deduce the payload length.
971 st
->payload
= st
->len
- st
->pad
- 1;
973 ssh
->pktin
.length
= st
->payload
+ 5;
976 * So now we can work out the total packet length.
978 st
->packetlen
= st
->len
+ 4;
979 st
->maclen
= ssh
->scmac ? ssh
->scmac
->len
: 0;
982 * Adjust memory allocation if packet is too big.
984 if (ssh
->pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
985 ssh
->pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
986 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
987 ssh
->pktin
.maxlen
+ APIEXTRA
);
991 * Read and decrypt the remainder of the packet.
993 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
995 while ((*datalen
) == 0)
996 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
997 ssh
->pktin
.data
[st
->i
] = *(*data
)++;
1000 /* Decrypt everything _except_ the MAC. */
1002 ssh
->sccipher
->decrypt(ssh
->sc_cipher_ctx
,
1003 ssh
->pktin
.data
+ st
->cipherblk
,
1004 st
->packetlen
- st
->cipherblk
);
1010 && !ssh
->scmac
->verify(ssh
->sc_mac_ctx
, ssh
->pktin
.data
, st
->len
+ 4,
1011 st
->incoming_sequence
)) {
1012 bombout((ssh
,"Incorrect MAC received on packet"));
1015 st
->incoming_sequence
++; /* whether or not we MACed */
1018 * Decompress packet payload.
1021 unsigned char *newpayload
;
1024 ssh
->sccomp
->decompress(ssh
->sc_comp_ctx
,
1025 ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5,
1026 &newpayload
, &newlen
)) {
1027 if (ssh
->pktin
.maxlen
< newlen
+ 5) {
1028 ssh
->pktin
.maxlen
= newlen
+ 5;
1029 ssh
->pktin
.data
= srealloc(ssh
->pktin
.data
,
1030 ssh
->pktin
.maxlen
+ APIEXTRA
);
1032 ssh
->pktin
.length
= 5 + newlen
;
1033 memcpy(ssh
->pktin
.data
+ 5, newpayload
, newlen
);
1038 ssh
->pktin
.savedpos
= 6;
1039 ssh
->pktin
.type
= ssh
->pktin
.data
[5];
1042 log_packet(ssh
->logctx
, PKT_INCOMING
, ssh
->pktin
.type
,
1043 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktin
.type
),
1044 ssh
->pktin
.data
+6, ssh
->pktin
.length
-6);
1046 switch (ssh
->pktin
.type
) {
1048 * These packets we must handle instantly.
1050 case SSH2_MSG_DISCONNECT
:
1052 /* log reason code in disconnect message */
1054 int reason
= GET_32BIT(ssh
->pktin
.data
+ 6);
1055 unsigned msglen
= GET_32BIT(ssh
->pktin
.data
+ 10);
1057 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
1058 sprintf(buf
, "Received disconnect message (%s)",
1059 ssh2_disconnect_reasons
[reason
]);
1061 sprintf(buf
, "Received disconnect message (unknown type %d)",
1065 strcpy(buf
, "Disconnection message text: ");
1066 nowlen
= strlen(buf
);
1067 if (msglen
> sizeof(buf
) - nowlen
- 1)
1068 msglen
= sizeof(buf
) - nowlen
- 1;
1069 memcpy(buf
+ nowlen
, ssh
->pktin
.data
+ 14, msglen
);
1070 buf
[nowlen
+ msglen
] = '\0';
1072 bombout((ssh
,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1074 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
1075 ssh2_disconnect_reasons
[reason
] : "unknown",
1080 case SSH2_MSG_IGNORE
:
1082 case SSH2_MSG_DEBUG
:
1084 /* log the debug message */
1086 /* int display = ssh->pktin.body[6]; */
1087 int stringlen
= GET_32BIT(ssh
->pktin
.data
+7);
1089 strcpy(buf
, "Remote debug message: ");
1090 prefix
= strlen(buf
);
1091 if (stringlen
> (int)(sizeof(buf
)-prefix
-1))
1092 stringlen
= sizeof(buf
)-prefix
-1;
1093 memcpy(buf
+ prefix
, ssh
->pktin
.data
+ 11, stringlen
);
1094 buf
[prefix
+ stringlen
] = '\0';
1097 goto next_packet
; /* FIXME: print the debug message */
1100 * These packets we need do nothing about here.
1102 case SSH2_MSG_UNIMPLEMENTED
:
1103 case SSH2_MSG_SERVICE_REQUEST
:
1104 case SSH2_MSG_SERVICE_ACCEPT
:
1105 case SSH2_MSG_KEXINIT
:
1106 case SSH2_MSG_NEWKEYS
:
1107 case SSH2_MSG_KEXDH_INIT
:
1108 case SSH2_MSG_KEXDH_REPLY
:
1109 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1110 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1111 case SSH2_MSG_KEX_DH_GEX_INIT
:
1112 case SSH2_MSG_KEX_DH_GEX_REPLY
:
1113 case SSH2_MSG_USERAUTH_REQUEST
:
1114 case SSH2_MSG_USERAUTH_FAILURE
:
1115 case SSH2_MSG_USERAUTH_SUCCESS
:
1116 case SSH2_MSG_USERAUTH_BANNER
:
1117 case SSH2_MSG_USERAUTH_PK_OK
:
1118 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1119 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1120 case SSH2_MSG_USERAUTH_INFO_RESPONSE
:
1121 case SSH2_MSG_GLOBAL_REQUEST
:
1122 case SSH2_MSG_REQUEST_SUCCESS
:
1123 case SSH2_MSG_REQUEST_FAILURE
:
1124 case SSH2_MSG_CHANNEL_OPEN
:
1125 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
:
1126 case SSH2_MSG_CHANNEL_OPEN_FAILURE
:
1127 case SSH2_MSG_CHANNEL_WINDOW_ADJUST
:
1128 case SSH2_MSG_CHANNEL_DATA
:
1129 case SSH2_MSG_CHANNEL_EXTENDED_DATA
:
1130 case SSH2_MSG_CHANNEL_EOF
:
1131 case SSH2_MSG_CHANNEL_CLOSE
:
1132 case SSH2_MSG_CHANNEL_REQUEST
:
1133 case SSH2_MSG_CHANNEL_SUCCESS
:
1134 case SSH2_MSG_CHANNEL_FAILURE
:
1138 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1141 ssh2_pkt_init(ssh
, SSH2_MSG_UNIMPLEMENTED
);
1142 ssh2_pkt_adduint32(ssh
, st
->incoming_sequence
- 1);
1150 static void ssh1_pktout_size(Ssh ssh
, int len
)
1154 len
+= 5; /* type and CRC */
1155 pad
= 8 - (len
% 8);
1158 ssh
->pktout
.length
= len
- 5;
1159 if (ssh
->pktout
.maxlen
< biglen
) {
1160 ssh
->pktout
.maxlen
= biglen
;
1162 /* Allocate enough buffer space for extra block
1163 * for MS CryptEncrypt() */
1164 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 12);
1166 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
, biglen
+ 4);
1169 ssh
->pktout
.body
= ssh
->pktout
.data
+ 4 + pad
+ 1;
1172 static void s_wrpkt_start(Ssh ssh
, int type
, int len
)
1174 ssh1_pktout_size(ssh
, len
);
1175 ssh
->pktout
.type
= type
;
1178 static int s_wrpkt_prepare(Ssh ssh
)
1180 int pad
, len
, biglen
, i
;
1183 ssh
->pktout
.body
[-1] = ssh
->pktout
.type
;
1186 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.type
,
1187 ssh1_pkt_type(ssh
->pktout
.type
),
1188 ssh
->pktout
.body
, ssh
->pktout
.length
);
1190 if (ssh
->v1_compressing
) {
1191 unsigned char *compblk
;
1193 zlib_compress_block(ssh
->cs_comp_ctx
,
1194 ssh
->pktout
.body
- 1, ssh
->pktout
.length
+ 1,
1195 &compblk
, &complen
);
1196 ssh1_pktout_size(ssh
, complen
- 1);
1197 memcpy(ssh
->pktout
.body
- 1, compblk
, complen
);
1201 len
= ssh
->pktout
.length
+ 5; /* type and CRC */
1202 pad
= 8 - (len
% 8);
1205 for (i
= 0; i
< pad
; i
++)
1206 ssh
->pktout
.data
[i
+ 4] = random_byte();
1207 crc
= crc32(ssh
->pktout
.data
+ 4, biglen
- 4);
1208 PUT_32BIT(ssh
->pktout
.data
+ biglen
, crc
);
1209 PUT_32BIT(ssh
->pktout
.data
, len
);
1212 ssh
->cipher
->encrypt(ssh
->v1_cipher_ctx
, ssh
->pktout
.data
+ 4, biglen
);
1217 static void s_wrpkt(Ssh ssh
)
1220 len
= s_wrpkt_prepare(ssh
);
1221 backlog
= sk_write(ssh
->s
, ssh
->pktout
.data
, len
);
1222 if (backlog
> SSH_MAX_BACKLOG
)
1223 ssh_throttle_all(ssh
, 1, backlog
);
1226 static void s_wrpkt_defer(Ssh ssh
)
1229 len
= s_wrpkt_prepare(ssh
);
1230 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1231 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1232 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1233 ssh
->deferred_size
);
1235 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1236 ssh
->deferred_len
+= len
;
1240 * Construct a packet with the specified contents.
1242 static void construct_packet(Ssh ssh
, int pkttype
, va_list ap1
, va_list ap2
)
1244 unsigned char *p
, *argp
, argchar
;
1245 unsigned long argint
;
1246 int pktlen
, argtype
, arglen
;
1250 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1253 (void) va_arg(ap1
, int);
1257 (void) va_arg(ap1
, char);
1261 (void) va_arg(ap1
, unsigned char *);
1262 arglen
= va_arg(ap1
, int);
1266 argp
= va_arg(ap1
, unsigned char *);
1267 arglen
= strlen(argp
);
1268 pktlen
+= 4 + arglen
;
1271 bn
= va_arg(ap1
, Bignum
);
1272 pktlen
+= ssh1_bignum_length(bn
);
1279 s_wrpkt_start(ssh
, pkttype
, pktlen
);
1280 p
= ssh
->pktout
.body
;
1282 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1285 argint
= va_arg(ap2
, int);
1286 PUT_32BIT(p
, argint
);
1290 argchar
= va_arg(ap2
, unsigned char);
1295 argp
= va_arg(ap2
, unsigned char *);
1296 arglen
= va_arg(ap2
, int);
1297 memcpy(p
, argp
, arglen
);
1301 argp
= va_arg(ap2
, unsigned char *);
1302 arglen
= strlen(argp
);
1303 PUT_32BIT(p
, arglen
);
1304 memcpy(p
+ 4, argp
, arglen
);
1308 bn
= va_arg(ap2
, Bignum
);
1309 p
+= ssh1_write_bignum(p
, bn
);
1315 static void send_packet(Ssh ssh
, int pkttype
, ...)
1318 va_start(ap1
, pkttype
);
1319 va_start(ap2
, pkttype
);
1320 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1324 static void defer_packet(Ssh ssh
, int pkttype
, ...)
1327 va_start(ap1
, pkttype
);
1328 va_start(ap2
, pkttype
);
1329 construct_packet(ssh
, pkttype
, ap1
, ap2
);
1333 static int ssh_versioncmp(char *a
, char *b
)
1336 unsigned long av
, bv
;
1338 av
= strtoul(a
, &ae
, 10);
1339 bv
= strtoul(b
, &be
, 10);
1341 return (av
< bv ?
-1 : +1);
1346 av
= strtoul(ae
, &ae
, 10);
1347 bv
= strtoul(be
, &be
, 10);
1349 return (av
< bv ?
-1 : +1);
1354 * Utility routines for putting an SSH-protocol `string' and
1355 * `uint32' into a SHA state.
1358 static void sha_string(SHA_State
* s
, void *str
, int len
)
1360 unsigned char lenblk
[4];
1361 PUT_32BIT(lenblk
, len
);
1362 SHA_Bytes(s
, lenblk
, 4);
1363 SHA_Bytes(s
, str
, len
);
1366 static void sha_uint32(SHA_State
* s
, unsigned i
)
1368 unsigned char intblk
[4];
1369 PUT_32BIT(intblk
, i
);
1370 SHA_Bytes(s
, intblk
, 4);
1374 * SSH2 packet construction functions.
1376 static void ssh2_pkt_ensure(Ssh ssh
, int length
)
1378 if (ssh
->pktout
.maxlen
< length
) {
1379 ssh
->pktout
.maxlen
= length
+ 256;
1380 ssh
->pktout
.data
= srealloc(ssh
->pktout
.data
,
1381 ssh
->pktout
.maxlen
+ APIEXTRA
);
1382 if (!ssh
->pktout
.data
)
1383 fatalbox("Out of memory");
1386 static void ssh2_pkt_adddata(Ssh ssh
, void *data
, int len
)
1388 ssh
->pktout
.length
+= len
;
1389 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
);
1390 memcpy(ssh
->pktout
.data
+ ssh
->pktout
.length
- len
, data
, len
);
1392 static void ssh2_pkt_addbyte(Ssh ssh
, unsigned char byte
)
1394 ssh2_pkt_adddata(ssh
, &byte
, 1);
1396 static void ssh2_pkt_init(Ssh ssh
, int pkt_type
)
1398 ssh
->pktout
.length
= 5;
1399 ssh2_pkt_addbyte(ssh
, (unsigned char) pkt_type
);
1401 static void ssh2_pkt_addbool(Ssh ssh
, unsigned char value
)
1403 ssh2_pkt_adddata(ssh
, &value
, 1);
1405 static void ssh2_pkt_adduint32(Ssh ssh
, unsigned long value
)
1408 PUT_32BIT(x
, value
);
1409 ssh2_pkt_adddata(ssh
, x
, 4);
1411 static void ssh2_pkt_addstring_start(Ssh ssh
)
1413 ssh2_pkt_adduint32(ssh
, 0);
1414 ssh
->pktout
.savedpos
= ssh
->pktout
.length
;
1416 static void ssh2_pkt_addstring_str(Ssh ssh
, char *data
)
1418 ssh2_pkt_adddata(ssh
, data
, strlen(data
));
1419 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1420 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1422 static void ssh2_pkt_addstring_data(Ssh ssh
, char *data
, int len
)
1424 ssh2_pkt_adddata(ssh
, data
, len
);
1425 PUT_32BIT(ssh
->pktout
.data
+ ssh
->pktout
.savedpos
- 4,
1426 ssh
->pktout
.length
- ssh
->pktout
.savedpos
);
1428 static void ssh2_pkt_addstring(Ssh ssh
, char *data
)
1430 ssh2_pkt_addstring_start(ssh
);
1431 ssh2_pkt_addstring_str(ssh
, data
);
1433 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1436 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1439 fatalbox("out of memory");
1441 for (i
= 1; i
<= n
; i
++)
1442 p
[i
] = bignum_byte(b
, n
- i
);
1444 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1446 memmove(p
, p
+ i
, n
+ 1 - i
);
1450 static void ssh2_pkt_addmp(Ssh ssh
, Bignum b
)
1454 p
= ssh2_mpint_fmt(b
, &len
);
1455 ssh2_pkt_addstring_start(ssh
);
1456 ssh2_pkt_addstring_data(ssh
, p
, len
);
1461 * Construct an SSH2 final-form packet: compress it, encrypt it,
1462 * put the MAC on it. Final packet, ready to be sent, is stored in
1463 * ssh->pktout.data. Total length is returned.
1465 static int ssh2_pkt_construct(Ssh ssh
)
1467 int cipherblk
, maclen
, padding
, i
;
1470 log_packet(ssh
->logctx
, PKT_OUTGOING
, ssh
->pktout
.data
[5],
1471 ssh2_pkt_type(ssh
->pkt_ctx
, ssh
->pktout
.data
[5]),
1472 ssh
->pktout
.data
+ 6, ssh
->pktout
.length
- 6);
1475 * Compress packet payload.
1478 unsigned char *newpayload
;
1481 ssh
->cscomp
->compress(ssh
->cs_comp_ctx
, ssh
->pktout
.data
+ 5,
1482 ssh
->pktout
.length
- 5,
1483 &newpayload
, &newlen
)) {
1484 ssh
->pktout
.length
= 5;
1485 ssh2_pkt_adddata(ssh
, newpayload
, newlen
);
1491 * Add padding. At least four bytes, and must also bring total
1492 * length (minus MAC) up to a multiple of the block size.
1494 cipherblk
= ssh
->cscipher ? ssh
->cscipher
->blksize
: 8; /* block size */
1495 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1498 (cipherblk
- (ssh
->pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1499 maclen
= ssh
->csmac ? ssh
->csmac
->len
: 0;
1500 ssh2_pkt_ensure(ssh
, ssh
->pktout
.length
+ padding
+ maclen
);
1501 ssh
->pktout
.data
[4] = padding
;
1502 for (i
= 0; i
< padding
; i
++)
1503 ssh
->pktout
.data
[ssh
->pktout
.length
+ i
] = random_byte();
1504 PUT_32BIT(ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
- 4);
1506 ssh
->csmac
->generate(ssh
->cs_mac_ctx
, ssh
->pktout
.data
,
1507 ssh
->pktout
.length
+ padding
,
1508 ssh
->v2_outgoing_sequence
);
1509 ssh
->v2_outgoing_sequence
++; /* whether or not we MACed */
1512 ssh
->cscipher
->encrypt(ssh
->cs_cipher_ctx
,
1513 ssh
->pktout
.data
, ssh
->pktout
.length
+ padding
);
1515 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1516 return ssh
->pktout
.length
+ padding
+ maclen
;
1520 * Construct and send an SSH2 packet immediately.
1522 static void ssh2_pkt_send(Ssh ssh
)
1526 len
= ssh2_pkt_construct(ssh
);
1527 backlog
= sk_write(ssh
->s
, ssh
->pktout
.data
, len
);
1528 if (backlog
> SSH_MAX_BACKLOG
)
1529 ssh_throttle_all(ssh
, 1, backlog
);
1533 * Construct an SSH2 packet and add it to a deferred data block.
1534 * Useful for sending multiple packets in a single sk_write() call,
1535 * to prevent a traffic-analysing listener from being able to work
1536 * out the length of any particular packet (such as the password
1539 * Note that because SSH2 sequence-numbers its packets, this can
1540 * NOT be used as an m4-style `defer' allowing packets to be
1541 * constructed in one order and sent in another.
1543 static void ssh2_pkt_defer(Ssh ssh
)
1545 int len
= ssh2_pkt_construct(ssh
);
1546 if (ssh
->deferred_len
+ len
> ssh
->deferred_size
) {
1547 ssh
->deferred_size
= ssh
->deferred_len
+ len
+ 128;
1548 ssh
->deferred_send_data
= srealloc(ssh
->deferred_send_data
,
1549 ssh
->deferred_size
);
1551 memcpy(ssh
->deferred_send_data
+ ssh
->deferred_len
, ssh
->pktout
.data
, len
);
1552 ssh
->deferred_len
+= len
;
1556 * Send the whole deferred data block constructed by
1557 * ssh2_pkt_defer() or SSH1's defer_packet().
1559 static void ssh_pkt_defersend(Ssh ssh
)
1562 backlog
= sk_write(ssh
->s
, ssh
->deferred_send_data
, ssh
->deferred_len
);
1563 ssh
->deferred_len
= ssh
->deferred_size
= 0;
1564 sfree(ssh
->deferred_send_data
);
1565 ssh
->deferred_send_data
= NULL
;
1566 if (backlog
> SSH_MAX_BACKLOG
)
1567 ssh_throttle_all(ssh
, 1, backlog
);
1571 void bndebug(char *string
, Bignum b
)
1575 p
= ssh2_mpint_fmt(b
, &len
);
1576 debug(("%s", string
));
1577 for (i
= 0; i
< len
; i
++)
1578 debug((" %02x", p
[i
]));
1584 static void sha_mpint(SHA_State
* s
, Bignum b
)
1588 p
= ssh2_mpint_fmt(b
, &len
);
1589 sha_string(s
, p
, len
);
1594 * SSH2 packet decode functions.
1596 static unsigned long ssh2_pkt_getuint32(Ssh ssh
)
1598 unsigned long value
;
1599 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1600 return 0; /* arrgh, no way to decline (FIXME?) */
1601 value
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1602 ssh
->pktin
.savedpos
+= 4;
1605 static int ssh2_pkt_getbool(Ssh ssh
)
1607 unsigned long value
;
1608 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 1)
1609 return 0; /* arrgh, no way to decline (FIXME?) */
1610 value
= ssh
->pktin
.data
[ssh
->pktin
.savedpos
] != 0;
1611 ssh
->pktin
.savedpos
++;
1614 static void ssh2_pkt_getstring(Ssh ssh
, char **p
, int *length
)
1618 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< 4)
1620 *length
= GET_32BIT(ssh
->pktin
.data
+ ssh
->pktin
.savedpos
);
1621 ssh
->pktin
.savedpos
+= 4;
1622 if (ssh
->pktin
.length
- ssh
->pktin
.savedpos
< *length
)
1624 *p
= ssh
->pktin
.data
+ ssh
->pktin
.savedpos
;
1625 ssh
->pktin
.savedpos
+= *length
;
1627 static Bignum
ssh2_pkt_getmp(Ssh ssh
)
1633 ssh2_pkt_getstring(ssh
, &p
, &length
);
1637 bombout((ssh
,"internal error: Can't handle negative mpints"));
1640 b
= bignum_from_bytes(p
, length
);
1645 * Helper function to add an SSH2 signature blob to a packet.
1646 * Expects to be shown the public key blob as well as the signature
1647 * blob. Normally works just like ssh2_pkt_addstring, but will
1648 * fiddle with the signature packet if necessary for
1649 * BUG_SSH2_RSA_PADDING.
1651 static void ssh2_add_sigblob(Ssh ssh
, void *pkblob_v
, int pkblob_len
,
1652 void *sigblob_v
, int sigblob_len
)
1654 unsigned char *pkblob
= (unsigned char *)pkblob_v
;
1655 unsigned char *sigblob
= (unsigned char *)sigblob_v
;
1657 /* dmemdump(pkblob, pkblob_len); */
1658 /* dmemdump(sigblob, sigblob_len); */
1661 * See if this is in fact an ssh-rsa signature and a buggy
1662 * server; otherwise we can just do this the easy way.
1664 if ((ssh
->remote_bugs
& BUG_SSH2_RSA_PADDING
) &&
1665 (GET_32BIT(pkblob
) == 7 && !memcmp(pkblob
+4, "ssh-rsa", 7))) {
1666 int pos
, len
, siglen
;
1669 * Find the byte length of the modulus.
1672 pos
= 4+7; /* skip over "ssh-rsa" */
1673 pos
+= 4 + GET_32BIT(pkblob
+pos
); /* skip over exponent */
1674 len
= GET_32BIT(pkblob
+pos
); /* find length of modulus */
1675 pos
+= 4; /* find modulus itself */
1676 while (len
> 0 && pkblob
[pos
] == 0)
1678 /* debug(("modulus length is %d\n", len)); */
1681 * Now find the signature integer.
1683 pos
= 4+7; /* skip over "ssh-rsa" */
1684 siglen
= GET_32BIT(sigblob
+pos
);
1685 /* debug(("signature length is %d\n", siglen)); */
1687 if (len
!= siglen
) {
1688 unsigned char newlen
[4];
1689 ssh2_pkt_addstring_start(ssh
);
1690 ssh2_pkt_addstring_data(ssh
, sigblob
, pos
);
1691 /* dmemdump(sigblob, pos); */
1692 pos
+= 4; /* point to start of actual sig */
1693 PUT_32BIT(newlen
, len
);
1694 ssh2_pkt_addstring_data(ssh
, newlen
, 4);
1695 /* dmemdump(newlen, 4); */
1697 while (len
-- > siglen
) {
1698 ssh2_pkt_addstring_data(ssh
, newlen
, 1);
1699 /* dmemdump(newlen, 1); */
1701 ssh2_pkt_addstring_data(ssh
, sigblob
+pos
, siglen
);
1702 /* dmemdump(sigblob+pos, siglen); */
1706 /* Otherwise fall through and do it the easy way. */
1709 ssh2_pkt_addstring_start(ssh
);
1710 ssh2_pkt_addstring_data(ssh
, sigblob
, sigblob_len
);
1714 * Examine the remote side's version string and compare it against
1715 * a list of known buggy implementations.
1717 static void ssh_detect_bugs(Ssh ssh
, char *vstring
)
1719 char *imp
; /* pointer to implementation part */
1721 imp
+= strcspn(imp
, "-");
1723 imp
+= strcspn(imp
, "-");
1726 ssh
->remote_bugs
= 0;
1728 if (cfg
.sshbug_ignore1
== BUG_ON
||
1729 (cfg
.sshbug_ignore1
== BUG_AUTO
&&
1730 (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1731 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1732 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")))) {
1734 * These versions don't support SSH1_MSG_IGNORE, so we have
1735 * to use a different defence against password length
1738 ssh
->remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1739 logevent("We believe remote version has SSH1 ignore bug");
1742 if (cfg
.sshbug_plainpw1
== BUG_ON
||
1743 (cfg
.sshbug_plainpw1
== BUG_AUTO
&&
1744 (!strcmp(imp
, "Cisco-1.25")))) {
1746 * These versions need a plain password sent; they can't
1747 * handle having a null and a random length of data after
1750 ssh
->remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1751 logevent("We believe remote version needs a plain SSH1 password");
1754 if (cfg
.sshbug_rsa1
== BUG_ON
||
1755 (cfg
.sshbug_rsa1
== BUG_AUTO
&&
1756 (!strcmp(imp
, "Cisco-1.25")))) {
1758 * These versions apparently have no clue whatever about
1759 * RSA authentication and will panic and die if they see
1760 * an AUTH_RSA message.
1762 ssh
->remote_bugs
|= BUG_CHOKES_ON_RSA
;
1763 logevent("We believe remote version can't handle RSA authentication");
1766 if (cfg
.sshbug_hmac2
== BUG_ON
||
1767 (cfg
.sshbug_hmac2
== BUG_AUTO
&&
1768 (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1769 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1770 !strncmp(imp
, "2.1 ", 4)))) {
1772 * These versions have the HMAC bug.
1774 ssh
->remote_bugs
|= BUG_SSH2_HMAC
;
1775 logevent("We believe remote version has SSH2 HMAC bug");
1778 if (cfg
.sshbug_derivekey2
== BUG_ON
||
1779 (cfg
.sshbug_derivekey2
== BUG_AUTO
&&
1780 (!strncmp(imp
, "2.0.", 4)))) {
1782 * These versions have the key-derivation bug (failing to
1783 * include the literal shared secret in the hashes that
1784 * generate the keys).
1786 ssh
->remote_bugs
|= BUG_SSH2_DERIVEKEY
;
1787 logevent("We believe remote version has SSH2 key-derivation bug");
1790 if (cfg
.sshbug_rsapad2
== BUG_ON
||
1791 (cfg
.sshbug_rsapad2
== BUG_AUTO
&&
1792 ((!strncmp(imp
, "OpenSSH_2.", 10) && imp
[10]>='5' && imp
[10]<='9') ||
1793 (!strncmp(imp
, "OpenSSH_3.", 10) && imp
[10]>='0' && imp
[10]<='2')))){
1795 * These versions have the SSH2 RSA padding bug.
1797 ssh
->remote_bugs
|= BUG_SSH2_RSA_PADDING
;
1798 logevent("We believe remote version has SSH2 RSA padding bug");
1801 if (cfg
.sshbug_dhgex2
== BUG_ON
) {
1803 * These versions have the SSH2 DH GEX bug.
1805 ssh
->remote_bugs
|= BUG_SSH2_DH_GEX
;
1806 logevent("We believe remote version has SSH2 DH group exchange bug");
1810 static int do_ssh_init(Ssh ssh
, unsigned char c
)
1812 struct do_ssh_init_state
{
1820 crState(do_ssh_init_state
);
1822 crBegin(ssh
->do_ssh_init_crstate
);
1824 /* Search for the string "SSH-" in the input. */
1827 static const int transS
[] = { 1, 2, 2, 1 };
1828 static const int transH
[] = { 0, 0, 3, 0 };
1829 static const int transminus
[] = { 0, 0, 0, -1 };
1831 s
->i
= transS
[s
->i
];
1833 s
->i
= transH
[s
->i
];
1835 s
->i
= transminus
[s
->i
];
1840 crReturn(1); /* get another character */
1844 s
->vstring
= smalloc(s
->vstrsize
);
1845 strcpy(s
->vstring
, "SSH-");
1849 crReturn(1); /* get another char */
1850 if (s
->vslen
>= s
->vstrsize
- 1) {
1852 s
->vstring
= srealloc(s
->vstring
, s
->vstrsize
);
1854 s
->vstring
[s
->vslen
++] = c
;
1857 s
->version
[s
->i
] = '\0';
1859 } else if (s
->i
< sizeof(s
->version
) - 1)
1860 s
->version
[s
->i
++] = c
;
1861 } else if (c
== '\n')
1865 ssh
->agentfwd_enabled
= FALSE
;
1866 ssh
->rdpkt2_state
.incoming_sequence
= 0;
1868 s
->vstring
[s
->vslen
] = 0;
1869 s
->vstring
[strcspn(s
->vstring
, "\r\n")] = '\0';/* remove EOL chars */
1872 vlog
= smalloc(20 + s
->vslen
);
1873 sprintf(vlog
, "Server version: %s", s
->vstring
);
1877 ssh_detect_bugs(ssh
, s
->vstring
);
1880 * Decide which SSH protocol version to support.
1883 /* Anything strictly below "2.0" means protocol 1 is supported. */
1884 s
->proto1
= ssh_versioncmp(s
->version
, "2.0") < 0;
1885 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1886 s
->proto2
= ssh_versioncmp(s
->version
, "1.99") >= 0;
1888 if (cfg
.sshprot
== 0 && !s
->proto1
) {
1889 bombout((ssh
,"SSH protocol version 1 required by user but not provided by server"));
1892 if (cfg
.sshprot
== 3 && !s
->proto2
) {
1893 bombout((ssh
,"SSH protocol version 2 required by user but not provided by server"));
1897 if (s
->proto2
&& (cfg
.sshprot
>= 2 || !s
->proto1
)) {
1901 char verstring
[80], vlog
[100];
1902 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1903 SHA_Init(&ssh
->exhashbase
);
1905 * Hash our version string and their version string.
1907 sha_string(&ssh
->exhashbase
, verstring
, strlen(verstring
));
1908 sha_string(&ssh
->exhashbase
, s
->vstring
, strcspn(s
->vstring
, "\r\n"));
1909 sprintf(vlog
, "We claim version: %s", verstring
);
1911 strcat(verstring
, "\n");
1912 logevent("Using SSH protocol version 2");
1913 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1914 ssh
->protocol
= ssh2_protocol
;
1916 ssh
->s_rdpkt
= ssh2_rdpkt
;
1921 char verstring
[80], vlog
[100];
1922 sprintf(verstring
, "SSH-%s-%s",
1923 (ssh_versioncmp(s
->version
, "1.5") <= 0 ? s
->version
: "1.5"),
1925 sprintf(vlog
, "We claim version: %s", verstring
);
1927 strcat(verstring
, "\n");
1929 logevent("Using SSH protocol version 1");
1930 sk_write(ssh
->s
, verstring
, strlen(verstring
));
1931 ssh
->protocol
= ssh1_protocol
;
1933 ssh
->s_rdpkt
= ssh1_rdpkt
;
1935 ssh
->state
= SSH_STATE_BEFORE_SIZE
;
1942 static void ssh_gotdata(Ssh ssh
, unsigned char *data
, int datalen
)
1944 crBegin(ssh
->ssh_gotdata_crstate
);
1947 * To begin with, feed the characters one by one to the
1948 * protocol initialisation / selection function do_ssh_init().
1949 * When that returns 0, we're done with the initial greeting
1950 * exchange and can move on to packet discipline.
1953 int ret
; /* need not be kept across crReturn */
1955 crReturnV
; /* more data please */
1956 ret
= do_ssh_init(ssh
, *data
);
1964 * We emerge from that loop when the initial negotiation is
1965 * over and we have selected an s_rdpkt function. Now pass
1966 * everything to s_rdpkt, and then pass the resulting packets
1967 * to the proper protocol handler.
1972 while (datalen
> 0) {
1973 if (ssh
->s_rdpkt(ssh
, &data
, &datalen
) == 0) {
1974 if (ssh
->state
== SSH_STATE_CLOSED
) {
1977 ssh
->protocol(ssh
, NULL
, 0, 1);
1978 if (ssh
->state
== SSH_STATE_CLOSED
) {
1988 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1991 Ssh ssh
= (Ssh
) plug
;
1992 ssh
->state
= SSH_STATE_CLOSED
;
1998 /* A socket error has occurred. */
1999 logevent(error_msg
);
2000 connection_fatal(ssh
->frontend
, error_msg
);
2002 /* Otherwise, the remote side closed the connection normally. */
2007 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
2009 Ssh ssh
= (Ssh
) plug
;
2010 ssh_gotdata(ssh
, data
, len
);
2011 if (ssh
->state
== SSH_STATE_CLOSED
) {
2021 static void ssh_sent(Plug plug
, int bufsize
)
2023 Ssh ssh
= (Ssh
) plug
;
2025 * If the send backlog on the SSH socket itself clears, we
2026 * should unthrottle the whole world if it was throttled.
2028 if (bufsize
< SSH_MAX_BACKLOG
)
2029 ssh_throttle_all(ssh
, 0, bufsize
);
2033 * Connect to specified host and port.
2034 * Returns an error message, or NULL on success.
2035 * Also places the canonical host name into `realhost'. It must be
2036 * freed by the caller.
2038 static char *connect_to_host(Ssh ssh
, char *host
, int port
,
2039 char **realhost
, int nodelay
)
2041 static const struct plug_function_table fn_table
= {
2051 ssh
->savedhost
= smalloc(1 + strlen(host
));
2052 if (!ssh
->savedhost
)
2053 fatalbox("Out of memory");
2054 strcpy(ssh
->savedhost
, host
);
2057 port
= 22; /* default ssh port */
2058 ssh
->savedport
= port
;
2065 sprintf(buf
, "Looking up host \"%.170s\"", host
);
2068 addr
= sk_namelookup(host
, realhost
);
2069 if ((err
= sk_addr_error(addr
)))
2076 char buf
[200], addrbuf
[100];
2077 sk_getaddr(addr
, addrbuf
, 100);
2078 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
2081 ssh
->fn
= &fn_table
;
2082 ssh
->s
= new_connection(addr
, *realhost
, port
, 0, 1, nodelay
, (Plug
) ssh
);
2083 if ((err
= sk_socket_error(ssh
->s
))) {
2092 * Throttle or unthrottle the SSH connection.
2094 static void ssh1_throttle(Ssh ssh
, int adjust
)
2096 int old_count
= ssh
->v1_throttle_count
;
2097 ssh
->v1_throttle_count
+= adjust
;
2098 assert(ssh
->v1_throttle_count
>= 0);
2099 if (ssh
->v1_throttle_count
&& !old_count
) {
2100 sk_set_frozen(ssh
->s
, 1);
2101 } else if (!ssh
->v1_throttle_count
&& old_count
) {
2102 sk_set_frozen(ssh
->s
, 0);
2107 * Throttle or unthrottle _all_ local data streams (for when sends
2108 * on the SSH connection itself back up).
2110 static void ssh_throttle_all(Ssh ssh
, int enable
, int bufsize
)
2113 struct ssh_channel
*c
;
2115 if (enable
== ssh
->throttled_all
)
2117 ssh
->throttled_all
= enable
;
2118 ssh
->overall_bufsize
= bufsize
;
2121 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
2123 case CHAN_MAINSESSION
:
2125 * This is treated separately, outside the switch.
2129 x11_override_throttle(c
->u
.x11
.s
, enable
);
2132 /* Agent channels require no buffer management. */
2135 pfd_override_throttle(c
->u
.x11
.s
, enable
);
2142 * Username and password input, abstracted off into routines
2143 * reusable in several places - even between SSH1 and SSH2.
2146 /* Set up a username or password input loop on a given buffer. */
2147 void setup_userpass_input(Ssh ssh
, char *buffer
, int buflen
, int echo
)
2149 ssh
->userpass_input_buffer
= buffer
;
2150 ssh
->userpass_input_buflen
= buflen
;
2151 ssh
->userpass_input_bufpos
= 0;
2152 ssh
->userpass_input_echo
= echo
;
2156 * Process some terminal data in the course of username/password
2157 * input. Returns >0 for success (line of input returned in
2158 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2159 * for inconclusive (keep waiting for more input please).
2161 int process_userpass_input(Ssh ssh
, unsigned char *in
, int inlen
)
2166 switch (c
= *in
++) {
2169 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
] = 0;
2170 ssh
->userpass_input_buffer
[ssh
->userpass_input_buflen
-1] = 0;
2175 if (ssh
->userpass_input_bufpos
> 0) {
2176 if (ssh
->userpass_input_echo
)
2177 c_write_str(ssh
, "\b \b");
2178 ssh
->userpass_input_bufpos
--;
2183 while (ssh
->userpass_input_bufpos
> 0) {
2184 if (ssh
->userpass_input_echo
)
2185 c_write_str(ssh
, "\b \b");
2186 ssh
->userpass_input_bufpos
--;
2194 if (((c
>= ' ' && c
<= '~') ||
2195 ((unsigned char) c
>= 160))
2196 && ssh
->userpass_input_bufpos
< ssh
->userpass_input_buflen
-1) {
2197 ssh
->userpass_input_buffer
[ssh
->userpass_input_bufpos
++] = c
;
2198 if (ssh
->userpass_input_echo
)
2199 c_write(ssh
, &c
, 1);
2208 * Handle the key exchange and user authentication phases.
2210 static int do_ssh1_login(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
2213 unsigned char cookie
[8];
2214 struct RSAKey servkey
, hostkey
;
2215 struct MD5Context md5c
;
2216 struct do_ssh1_login_state
{
2218 unsigned char *rsabuf
, *keystr1
, *keystr2
;
2219 unsigned long supported_ciphers_mask
, supported_auths_mask
;
2220 int tried_publickey
, tried_agent
;
2221 int tis_auth_refused
, ccard_auth_refused
;
2222 unsigned char session_id
[16];
2225 void *publickey_blob
;
2226 int publickey_bloblen
;
2232 unsigned char request
[5], *response
, *p
;
2241 crState(do_ssh1_login_state
);
2243 crBegin(ssh
->do_ssh1_login_crstate
);
2248 if (ssh
->pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
2249 bombout((ssh
,"Public key packet not received"));
2253 logevent("Received public keys");
2255 memcpy(cookie
, ssh
->pktin
.body
, 8);
2257 i
= makekey(ssh
->pktin
.body
+ 8, &servkey
, &s
->keystr1
, 0);
2258 j
= makekey(ssh
->pktin
.body
+ 8 + i
, &hostkey
, &s
->keystr2
, 0);
2261 * Log the host key fingerprint.
2265 logevent("Host key fingerprint is:");
2266 strcpy(logmsg
, " ");
2267 hostkey
.comment
= NULL
;
2268 rsa_fingerprint(logmsg
+ strlen(logmsg
),
2269 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
2273 ssh
->v1_remote_protoflags
= GET_32BIT(ssh
->pktin
.body
+ 8 + i
+ j
);
2274 s
->supported_ciphers_mask
= GET_32BIT(ssh
->pktin
.body
+ 12 + i
+ j
);
2275 s
->supported_auths_mask
= GET_32BIT(ssh
->pktin
.body
+ 16 + i
+ j
);
2277 ssh
->v1_local_protoflags
=
2278 ssh
->v1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
2279 ssh
->v1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
2282 MD5Update(&md5c
, s
->keystr2
, hostkey
.bytes
);
2283 MD5Update(&md5c
, s
->keystr1
, servkey
.bytes
);
2284 MD5Update(&md5c
, ssh
->pktin
.body
, 8);
2285 MD5Final(s
->session_id
, &md5c
);
2287 for (i
= 0; i
< 32; i
++)
2288 ssh
->session_key
[i
] = random_byte();
2290 s
->len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
2292 s
->rsabuf
= smalloc(s
->len
);
2294 fatalbox("Out of memory");
2297 * Verify the host key.
2301 * First format the key into a string.
2303 int len
= rsastr_len(&hostkey
);
2304 char fingerprint
[100];
2305 char *keystr
= smalloc(len
);
2307 fatalbox("Out of memory");
2308 rsastr_fmt(keystr
, &hostkey
);
2309 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
2310 verify_ssh_host_key(ssh
->frontend
,
2311 ssh
->savedhost
, ssh
->savedport
, "rsa", keystr
,
2316 for (i
= 0; i
< 32; i
++) {
2317 s
->rsabuf
[i
] = ssh
->session_key
[i
];
2319 s
->rsabuf
[i
] ^= s
->session_id
[i
];
2322 if (hostkey
.bytes
> servkey
.bytes
) {
2323 rsaencrypt(s
->rsabuf
, 32, &servkey
);
2324 rsaencrypt(s
->rsabuf
, servkey
.bytes
, &hostkey
);
2326 rsaencrypt(s
->rsabuf
, 32, &hostkey
);
2327 rsaencrypt(s
->rsabuf
, hostkey
.bytes
, &servkey
);
2330 logevent("Encrypted session key");
2333 int cipher_chosen
= 0, warn
= 0;
2334 char *cipher_string
= NULL
;
2336 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
2337 int next_cipher
= cfg
.ssh_cipherlist
[i
];
2338 if (next_cipher
== CIPHER_WARN
) {
2339 /* If/when we choose a cipher, warn about it */
2341 } else if (next_cipher
== CIPHER_AES
) {
2342 /* XXX Probably don't need to mention this. */
2343 logevent("AES not supported in SSH1, skipping");
2345 switch (next_cipher
) {
2346 case CIPHER_3DES
: s
->cipher_type
= SSH_CIPHER_3DES
;
2347 cipher_string
= "3DES"; break;
2348 case CIPHER_BLOWFISH
: s
->cipher_type
= SSH_CIPHER_BLOWFISH
;
2349 cipher_string
= "Blowfish"; break;
2350 case CIPHER_DES
: s
->cipher_type
= SSH_CIPHER_DES
;
2351 cipher_string
= "single-DES"; break;
2353 if (s
->supported_ciphers_mask
& (1 << s
->cipher_type
))
2357 if (!cipher_chosen
) {
2358 if ((s
->supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
2359 bombout((ssh
,"Server violates SSH 1 protocol by not "
2360 "supporting 3DES encryption"));
2362 /* shouldn't happen */
2363 bombout((ssh
,"No supported ciphers found"));
2367 /* Warn about chosen cipher if necessary. */
2369 askcipher(ssh
->frontend
, cipher_string
, 0);
2372 switch (s
->cipher_type
) {
2373 case SSH_CIPHER_3DES
:
2374 logevent("Using 3DES encryption");
2376 case SSH_CIPHER_DES
:
2377 logevent("Using single-DES encryption");
2379 case SSH_CIPHER_BLOWFISH
:
2380 logevent("Using Blowfish encryption");
2384 send_packet(ssh
, SSH1_CMSG_SESSION_KEY
,
2385 PKT_CHAR
, s
->cipher_type
,
2386 PKT_DATA
, cookie
, 8,
2387 PKT_CHAR
, (s
->len
* 8) >> 8, PKT_CHAR
, (s
->len
* 8) & 0xFF,
2388 PKT_DATA
, s
->rsabuf
, s
->len
,
2389 PKT_INT
, ssh
->v1_local_protoflags
, PKT_END
);
2391 logevent("Trying to enable encryption...");
2395 ssh
->cipher
= (s
->cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
2396 s
->cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
2398 ssh
->v1_cipher_ctx
= ssh
->cipher
->make_context();
2399 ssh
->cipher
->sesskey(ssh
->v1_cipher_ctx
, ssh
->session_key
);
2402 sprintf(buf
, "Initialised %.200s encryption", ssh
->cipher
->text_name
);
2406 ssh
->crcda_ctx
= crcda_make_context();
2407 logevent("Installing CRC compensation attack detector");
2411 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2412 bombout((ssh
,"Encryption not successfully enabled"));
2416 logevent("Successfully started encryption");
2420 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2421 if (ssh_get_line
&& !ssh_getline_pw_only
) {
2422 if (!ssh_get_line("login as: ",
2423 s
->username
, sizeof(s
->username
), FALSE
)) {
2425 * get_line failed to get a username.
2428 logevent("No username provided. Abandoning session.");
2429 ssh
->state
= SSH_STATE_CLOSED
;
2433 int ret
; /* need not be kept over crReturn */
2434 c_write_str(ssh
, "login as: ");
2437 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
2439 crWaitUntil(!ispkt
);
2440 ret
= process_userpass_input(ssh
, in
, inlen
);
2444 c_write_str(ssh
, "\r\n");
2447 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
2448 s
->username
[sizeof(s
->username
)-1] = '\0';
2451 send_packet(ssh
, SSH1_CMSG_USER
, PKT_STR
, s
->username
, PKT_END
);
2453 char userlog
[22 + sizeof(s
->username
)];
2454 sprintf(userlog
, "Sent username \"%s\"", s
->username
);
2456 if (flags
& FLAG_INTERACTIVE
&&
2457 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2458 strcat(userlog
, "\r\n");
2459 c_write_str(ssh
, userlog
);
2466 if ((ssh
->remote_bugs
& BUG_CHOKES_ON_RSA
)) {
2467 /* We must not attempt PK auth. Pretend we've already tried it. */
2468 s
->tried_publickey
= s
->tried_agent
= 1;
2470 s
->tried_publickey
= s
->tried_agent
= 0;
2472 s
->tis_auth_refused
= s
->ccard_auth_refused
= 0;
2473 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2475 if (!rsakey_pubblob(cfg
.keyfile
,
2476 &s
->publickey_blob
, &s
->publickey_bloblen
))
2477 s
->publickey_blob
= NULL
;
2479 s
->publickey_blob
= NULL
;
2481 while (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2482 s
->pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2484 if (agent_exists() && !s
->tried_agent
) {
2486 * Attempt RSA authentication using Pageant.
2492 logevent("Pageant is running. Requesting keys.");
2494 /* Request the keys held by the agent. */
2495 PUT_32BIT(s
->request
, 1);
2496 s
->request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2497 agent_query(s
->request
, 5, &r
, &s
->responselen
);
2498 s
->response
= (unsigned char *) r
;
2499 if (s
->response
&& s
->responselen
>= 5 &&
2500 s
->response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2501 s
->p
= s
->response
+ 5;
2502 s
->nkeys
= GET_32BIT(s
->p
);
2506 sprintf(buf
, "Pageant has %d SSH1 keys", s
->nkeys
);
2509 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
2512 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
2515 if (s
->publickey_blob
&&
2516 !memcmp(s
->p
, s
->publickey_blob
,
2517 s
->publickey_bloblen
)) {
2518 logevent("This key matches configured key file");
2519 s
->tried_publickey
= 1;
2522 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.exponent
);
2523 s
->p
+= ssh1_read_bignum(s
->p
, &s
->key
.modulus
);
2524 s
->commentlen
= GET_32BIT(s
->p
);
2527 s
->p
+= s
->commentlen
;
2528 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2529 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2531 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2532 logevent("Key refused");
2535 logevent("Received RSA challenge");
2536 ssh1_read_bignum(ssh
->pktin
.body
, &s
->challenge
);
2538 char *agentreq
, *q
, *ret
;
2541 len
= 1 + 4; /* message type, bit count */
2542 len
+= ssh1_bignum_length(s
->key
.exponent
);
2543 len
+= ssh1_bignum_length(s
->key
.modulus
);
2544 len
+= ssh1_bignum_length(s
->challenge
);
2545 len
+= 16; /* session id */
2546 len
+= 4; /* response format */
2547 agentreq
= smalloc(4 + len
);
2548 PUT_32BIT(agentreq
, len
);
2550 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2551 PUT_32BIT(q
, bignum_bitcount(s
->key
.modulus
));
2553 q
+= ssh1_write_bignum(q
, s
->key
.exponent
);
2554 q
+= ssh1_write_bignum(q
, s
->key
.modulus
);
2555 q
+= ssh1_write_bignum(q
, s
->challenge
);
2556 memcpy(q
, s
->session_id
, 16);
2558 PUT_32BIT(q
, 1); /* response format */
2559 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2563 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2564 logevent("Sending Pageant's response");
2565 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2566 PKT_DATA
, ret
+ 5, 16,
2570 if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
2572 ("Pageant's response accepted");
2573 if (flags
& FLAG_VERBOSE
) {
2574 c_write_str(ssh
, "Authenticated using"
2576 c_write(ssh
, s
->commentp
,
2578 c_write_str(ssh
, "\" from agent\r\n");
2583 ("Pageant's response not accepted");
2586 ("Pageant failed to answer challenge");
2590 logevent("No reply received from Pageant");
2593 freebn(s
->key
.exponent
);
2594 freebn(s
->key
.modulus
);
2595 freebn(s
->challenge
);
2603 if (*cfg
.keyfile
&& !s
->tried_publickey
)
2604 s
->pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2606 if (cfg
.try_tis_auth
&&
2607 (s
->supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2608 !s
->tis_auth_refused
) {
2609 s
->pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2610 logevent("Requested TIS authentication");
2611 send_packet(ssh
, SSH1_CMSG_AUTH_TIS
, PKT_END
);
2613 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2614 logevent("TIS authentication declined");
2615 if (flags
& FLAG_INTERACTIVE
)
2616 c_write_str(ssh
, "TIS authentication refused.\r\n");
2617 s
->tis_auth_refused
= 1;
2620 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2621 logevent("Received TIS challenge");
2622 if (challengelen
> sizeof(s
->prompt
) - 1)
2623 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2624 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2625 /* Prompt heuristic comes from OpenSSH */
2626 strncpy(s
->prompt
+ challengelen
,
2627 memchr(s
->prompt
, '\n', challengelen
) ?
2628 "": "\r\nResponse: ",
2629 (sizeof s
->prompt
) - challengelen
);
2630 s
->prompt
[(sizeof s
->prompt
) - 1] = '\0';
2633 if (cfg
.try_tis_auth
&&
2634 (s
->supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2635 !s
->ccard_auth_refused
) {
2636 s
->pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2637 logevent("Requested CryptoCard authentication");
2638 send_packet(ssh
, SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2640 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2641 logevent("CryptoCard authentication declined");
2642 c_write_str(ssh
, "CryptoCard authentication refused.\r\n");
2643 s
->ccard_auth_refused
= 1;
2646 int challengelen
= GET_32BIT(ssh
->pktin
.body
);
2647 logevent("Received CryptoCard challenge");
2648 if (challengelen
> sizeof(s
->prompt
) - 1)
2649 challengelen
= sizeof(s
->prompt
) - 1;/* prevent overrun */
2650 memcpy(s
->prompt
, ssh
->pktin
.body
+ 4, challengelen
);
2651 strncpy(s
->prompt
+ challengelen
,
2652 memchr(s
->prompt
, '\n', challengelen
) ?
2653 "" : "\r\nResponse: ",
2654 sizeof(s
->prompt
) - challengelen
);
2655 s
->prompt
[sizeof(s
->prompt
) - 1] = '\0';
2658 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2659 sprintf(s
->prompt
, "%.90s@%.90s's password: ",
2660 s
->username
, ssh
->savedhost
);
2662 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2663 char *comment
= NULL
;
2666 if (flags
& FLAG_VERBOSE
)
2667 c_write_str(ssh
, "Trying public key authentication.\r\n");
2668 sprintf(msgbuf
, "Trying public key \"%.200s\"", cfg
.keyfile
);
2670 type
= key_type(cfg
.keyfile
);
2671 if (type
!= SSH_KEYTYPE_SSH1
) {
2672 sprintf(msgbuf
, "Key is of wrong type (%s)",
2673 key_type_to_str(type
));
2675 c_write_str(ssh
, msgbuf
);
2676 c_write_str(ssh
, "\r\n");
2677 s
->tried_publickey
= 1;
2680 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2681 if (flags
& FLAG_VERBOSE
)
2682 c_write_str(ssh
, "No passphrase required.\r\n");
2685 sprintf(s
->prompt
, "Passphrase for key \"%.100s\": ", comment
);
2690 * Show password prompt, having first obtained it via a TIS
2691 * or CryptoCard exchange if we're doing TIS or CryptoCard
2695 if (!ssh_get_line(s
->prompt
, s
->password
,
2696 sizeof(s
->password
), TRUE
)) {
2698 * get_line failed to get a password (for example
2699 * because one was supplied on the command line
2700 * which has already failed to work). Terminate.
2702 send_packet(ssh
, SSH1_MSG_DISCONNECT
,
2703 PKT_STR
, "No more passwords available to try",
2705 logevent("Unable to authenticate");
2706 connection_fatal(ssh
->frontend
, "Unable to authenticate");
2707 ssh
->state
= SSH_STATE_CLOSED
;
2711 /* Prompt may have come from server. We've munged it a bit, so
2712 * we know it to be zero-terminated at least once. */
2713 int ret
; /* need not be saved over crReturn */
2714 c_write_untrusted(ssh
, s
->prompt
, strlen(s
->prompt
));
2717 setup_userpass_input(ssh
, s
->password
, sizeof(s
->password
), 0);
2719 crWaitUntil(!ispkt
);
2720 ret
= process_userpass_input(ssh
, in
, inlen
);
2724 c_write_str(ssh
, "\r\n");
2728 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2730 * Try public key authentication with the specified
2733 s
->tried_publickey
= 1;
2736 int ret
= loadrsakey(cfg
.keyfile
, &s
->key
, s
->password
);
2738 c_write_str(ssh
, "Couldn't load private key from ");
2739 c_write_str(ssh
, cfg
.keyfile
);
2740 c_write_str(ssh
, ".\r\n");
2741 continue; /* go and try password */
2744 c_write_str(ssh
, "Wrong passphrase.\r\n");
2745 s
->tried_publickey
= 0;
2746 continue; /* try again */
2751 * Send a public key attempt.
2753 send_packet(ssh
, SSH1_CMSG_AUTH_RSA
,
2754 PKT_BIGNUM
, s
->key
.modulus
, PKT_END
);
2757 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2758 c_write_str(ssh
, "Server refused our public key.\r\n");
2759 continue; /* go and try password */
2761 if (ssh
->pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2762 bombout((ssh
,"Bizarre response to offer of public key"));
2768 unsigned char buffer
[32];
2769 Bignum challenge
, response
;
2771 ssh1_read_bignum(ssh
->pktin
.body
, &challenge
);
2772 response
= rsadecrypt(challenge
, &s
->key
);
2773 freebn(s
->key
.private_exponent
);/* burn the evidence */
2775 for (i
= 0; i
< 32; i
++) {
2776 buffer
[i
] = bignum_byte(response
, 31 - i
);
2780 MD5Update(&md5c
, buffer
, 32);
2781 MD5Update(&md5c
, s
->session_id
, 16);
2782 MD5Final(buffer
, &md5c
);
2784 send_packet(ssh
, SSH1_CMSG_AUTH_RSA_RESPONSE
,
2785 PKT_DATA
, buffer
, 16, PKT_END
);
2792 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2793 if (flags
& FLAG_VERBOSE
)
2794 c_write_str(ssh
, "Failed to authenticate with"
2795 " our public key.\r\n");
2796 continue; /* go and try password */
2797 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2798 bombout((ssh
,"Bizarre response to RSA authentication response"));
2802 break; /* we're through! */
2804 if (s
->pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2806 * Defence against traffic analysis: we send a
2807 * whole bunch of packets containing strings of
2808 * different lengths. One of these strings is the
2809 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2810 * The others are all random data in
2811 * SSH1_MSG_IGNORE packets. This way a passive
2812 * listener can't tell which is the password, and
2813 * hence can't deduce the password length.
2815 * Anybody with a password length greater than 16
2816 * bytes is going to have enough entropy in their
2817 * password that a listener won't find it _that_
2818 * much help to know how long it is. So what we'll
2821 * - if password length < 16, we send 15 packets
2822 * containing string lengths 1 through 15
2824 * - otherwise, we let N be the nearest multiple
2825 * of 8 below the password length, and send 8
2826 * packets containing string lengths N through
2827 * N+7. This won't obscure the order of
2828 * magnitude of the password length, but it will
2829 * introduce a bit of extra uncertainty.
2831 * A few servers (the old 1.2.18 through 1.2.22)
2832 * can't deal with SSH1_MSG_IGNORE. For these
2833 * servers, we need an alternative defence. We make
2834 * use of the fact that the password is interpreted
2835 * as a C string: so we can append a NUL, then some
2838 * One server (a Cisco one) can deal with neither
2839 * SSH1_MSG_IGNORE _nor_ a padded password string.
2840 * For this server we are left with no defences
2841 * against password length sniffing.
2843 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2845 * The server can deal with SSH1_MSG_IGNORE, so
2846 * we can use the primary defence.
2848 int bottom
, top
, pwlen
, i
;
2851 pwlen
= strlen(s
->password
);
2853 bottom
= 0; /* zero length passwords are OK! :-) */
2856 bottom
= pwlen
& ~7;
2860 assert(pwlen
>= bottom
&& pwlen
<= top
);
2862 randomstr
= smalloc(top
+ 1);
2864 for (i
= bottom
; i
<= top
; i
++) {
2866 defer_packet(ssh
, s
->pwpkt_type
,
2867 PKT_STR
, s
->password
, PKT_END
);
2869 for (j
= 0; j
< i
; j
++) {
2871 randomstr
[j
] = random_byte();
2872 } while (randomstr
[j
] == '\0');
2874 randomstr
[i
] = '\0';
2875 defer_packet(ssh
, SSH1_MSG_IGNORE
,
2876 PKT_STR
, randomstr
, PKT_END
);
2879 logevent("Sending password with camouflage packets");
2880 ssh_pkt_defersend(ssh
);
2882 else if (!(ssh
->remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2884 * The server can't deal with SSH1_MSG_IGNORE
2885 * but can deal with padded passwords, so we
2886 * can use the secondary defence.
2892 len
= strlen(s
->password
);
2893 if (len
< sizeof(string
)) {
2895 strcpy(string
, s
->password
);
2896 len
++; /* cover the zero byte */
2897 while (len
< sizeof(string
)) {
2898 string
[len
++] = (char) random_byte();
2903 logevent("Sending length-padded password");
2904 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2905 PKT_DATA
, ss
, len
, PKT_END
);
2908 * The server has _both_
2909 * BUG_CHOKES_ON_SSH1_IGNORE and
2910 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2911 * therefore nothing we can do.
2914 len
= strlen(s
->password
);
2915 logevent("Sending unpadded password");
2916 send_packet(ssh
, s
->pwpkt_type
, PKT_INT
, len
,
2917 PKT_DATA
, s
->password
, len
, PKT_END
);
2920 send_packet(ssh
, s
->pwpkt_type
, PKT_STR
, s
->password
, PKT_END
);
2923 logevent("Sent password");
2924 memset(s
->password
, 0, strlen(s
->password
));
2926 if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
2927 if (flags
& FLAG_VERBOSE
)
2928 c_write_str(ssh
, "Access denied\r\n");
2929 logevent("Authentication refused");
2930 } else if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2931 bombout((ssh
,"Strange packet received, type %d", ssh
->pktin
.type
));
2936 logevent("Authentication successful");
2941 void sshfwd_close(struct ssh_channel
*c
)
2945 if (c
&& !c
->closes
) {
2947 * If the channel's remoteid is -1, we have sent
2948 * CHANNEL_OPEN for this channel, but it hasn't even been
2949 * acknowledged by the server. So we must set a close flag
2950 * on it now, and then when the server acks the channel
2951 * open, we can close it then.
2953 if (((int)c
->remoteid
) != -1) {
2954 if (ssh
->version
== 1) {
2955 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2958 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
2959 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
2963 c
->closes
= 1; /* sent MSG_CLOSE */
2964 if (c
->type
== CHAN_X11
) {
2966 logevent("Forwarded X11 connection terminated");
2967 } else if (c
->type
== CHAN_SOCKDATA
||
2968 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2970 logevent("Forwarded port closed");
2975 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2979 if (ssh
->version
== 1) {
2980 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
2981 PKT_INT
, c
->remoteid
,
2982 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2984 * In SSH1 we can return 0 here - implying that forwarded
2985 * connections are never individually throttled - because
2986 * the only circumstance that can cause throttling will be
2987 * the whole SSH connection backing up, in which case
2988 * _everything_ will be throttled as a whole.
2992 ssh2_add_channel_data(c
, buf
, len
);
2993 return ssh2_try_send(c
);
2997 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
3001 if (ssh
->version
== 1) {
3002 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
3003 c
->v
.v1
.throttling
= 0;
3004 ssh1_throttle(ssh
, -1);
3007 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
3011 static void ssh1_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3013 crBegin(ssh
->ssh1_protocol_crstate
);
3017 while (!do_ssh1_login(ssh
, in
, inlen
, ispkt
)) {
3020 if (ssh
->state
== SSH_STATE_CLOSED
)
3023 if (cfg
.agentfwd
&& agent_exists()) {
3024 logevent("Requesting agent forwarding");
3025 send_packet(ssh
, SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
3029 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3030 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3031 bombout((ssh
,"Protocol confusion"));
3033 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3034 logevent("Agent forwarding refused");
3036 logevent("Agent forwarding enabled");
3037 ssh
->agentfwd_enabled
= TRUE
;
3041 if (cfg
.x11_forward
) {
3042 char proto
[20], data
[64];
3043 logevent("Requesting X11 forwarding");
3044 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
3045 data
, sizeof(data
));
3046 if (ssh
->v1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
3047 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3048 PKT_STR
, proto
, PKT_STR
, data
,
3049 PKT_INT
, 0, PKT_END
);
3051 send_packet(ssh
, SSH1_CMSG_X11_REQUEST_FORWARDING
,
3052 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
3057 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3058 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3059 bombout((ssh
,"Protocol confusion"));
3061 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3062 logevent("X11 forwarding refused");
3064 logevent("X11 forwarding enabled");
3065 ssh
->X11_fwd_enabled
= TRUE
;
3072 int sport
,dport
,sserv
,dserv
;
3073 char sports
[256], dports
[256], host
[256];
3077 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh1
);
3078 /* Add port forwardings. */
3079 ssh
->portfwd_strptr
= cfg
.portfwd
;
3080 while (*ssh
->portfwd_strptr
) {
3081 type
= *ssh
->portfwd_strptr
++;
3083 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t')
3084 sports
[n
++] = *ssh
->portfwd_strptr
++;
3086 if (*ssh
->portfwd_strptr
== '\t')
3087 ssh
->portfwd_strptr
++;
3089 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':')
3090 host
[n
++] = *ssh
->portfwd_strptr
++;
3092 if (*ssh
->portfwd_strptr
== ':')
3093 ssh
->portfwd_strptr
++;
3095 while (*ssh
->portfwd_strptr
)
3096 dports
[n
++] = *ssh
->portfwd_strptr
++;
3098 ssh
->portfwd_strptr
++;
3099 dport
= atoi(dports
);
3103 se
= getservbyname(dports
, NULL
);
3105 dport
= ntohs(se
->s_port
);
3108 "Service lookup failed for destination port \"%s\"",
3113 sport
= atoi(sports
);
3117 se
= getservbyname(sports
, NULL
);
3119 sport
= ntohs(se
->s_port
);
3122 "Service lookup failed for source port \"%s\"",
3127 if (sport
&& dport
) {
3129 pfd_addforward(host
, dport
, sport
, ssh
);
3130 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
3131 " %s:%.*s%.*s%d%.*s",
3132 sserv ?
strlen(sports
) : 0, sports
,
3133 sserv
, "(", sport
, sserv
, ")",
3135 dserv ?
strlen(dports
) : 0, dports
,
3136 dserv
, "(", dport
, dserv
, ")");
3139 struct ssh_rportfwd
*pf
;
3140 pf
= smalloc(sizeof(*pf
));
3141 strcpy(pf
->dhost
, host
);
3143 if (add234(ssh
->rportfwds
, pf
) != pf
) {
3145 "Duplicate remote port forwarding to %s:%d",
3150 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
3151 " forward to %s:%.*s%.*s%d%.*s",
3152 sserv ?
strlen(sports
) : 0, sports
,
3153 sserv
, "(", sport
, sserv
, ")",
3155 dserv ?
strlen(dports
) : 0, dports
,
3156 dserv
, "(", dport
, dserv
, ")");
3158 send_packet(ssh
, SSH1_CMSG_PORT_FORWARD_REQUEST
,
3166 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3167 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3168 bombout((ssh
,"Protocol confusion"));
3170 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3171 c_write_str(ssh
, "Server refused port"
3174 logevent("Remote port forwarding enabled");
3182 send_packet(ssh
, SSH1_CMSG_REQUEST_PTY
,
3183 PKT_STR
, cfg
.termtype
,
3184 PKT_INT
, ssh
->term_height
,
3185 PKT_INT
, ssh
->term_width
,
3186 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
3187 ssh
->state
= SSH_STATE_INTERMED
;
3191 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3192 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3193 bombout((ssh
,"Protocol confusion"));
3195 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3196 c_write_str(ssh
, "Server refused to allocate pty\r\n");
3197 ssh
->editing
= ssh
->echoing
= 1;
3199 logevent("Allocated pty");
3201 ssh
->editing
= ssh
->echoing
= 1;
3204 if (cfg
.compression
) {
3205 send_packet(ssh
, SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
3209 if (ssh
->pktin
.type
!= SSH1_SMSG_SUCCESS
3210 && ssh
->pktin
.type
!= SSH1_SMSG_FAILURE
) {
3211 bombout((ssh
,"Protocol confusion"));
3213 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3214 c_write_str(ssh
, "Server refused to compress\r\n");
3216 logevent("Started compression");
3217 ssh
->v1_compressing
= TRUE
;
3218 ssh
->cs_comp_ctx
= zlib_compress_init();
3219 logevent("Initialised zlib (RFC1950) compression");
3220 ssh
->sc_comp_ctx
= zlib_decompress_init();
3221 logevent("Initialised zlib (RFC1950) decompression");
3225 * Start the shell or command.
3227 * Special case: if the first-choice command is an SSH2
3228 * subsystem (hence not usable here) and the second choice
3229 * exists, we fall straight back to that.
3232 char *cmd
= cfg
.remote_cmd_ptr
;
3234 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
3235 cmd
= cfg
.remote_cmd_ptr2
;
3236 ssh
->fallback_cmd
= TRUE
;
3239 send_packet(ssh
, SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
3241 send_packet(ssh
, SSH1_CMSG_EXEC_SHELL
, PKT_END
);
3242 logevent("Started session");
3245 ssh
->state
= SSH_STATE_SESSION
;
3246 if (ssh
->size_needed
)
3247 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
3248 if (ssh
->eof_needed
)
3249 ssh_special(ssh
, TS_EOF
);
3252 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
3254 ssh
->channels
= newtree234(ssh_channelcmp
);
3258 if (ssh
->pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
3259 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
3260 long len
= GET_32BIT(ssh
->pktin
.body
);
3262 from_backend(ssh
->frontend
,
3263 ssh
->pktin
.type
== SSH1_SMSG_STDERR_DATA
,
3264 ssh
->pktin
.body
+ 4, len
);
3265 if (!ssh
->v1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3266 ssh
->v1_stdout_throttling
= 1;
3267 ssh1_throttle(ssh
, +1);
3269 } else if (ssh
->pktin
.type
== SSH1_MSG_DISCONNECT
) {
3270 ssh
->state
= SSH_STATE_CLOSED
;
3271 logevent("Received disconnect request");
3273 } else if (ssh
->pktin
.type
== SSH1_SMSG_X11_OPEN
) {
3274 /* Remote side is trying to open a channel to talk to our
3275 * X-Server. Give them back a local channel number. */
3276 struct ssh_channel
*c
;
3278 logevent("Received X11 connect request");
3279 /* Refuse if X11 forwarding is disabled. */
3280 if (!ssh
->X11_fwd_enabled
) {
3281 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3282 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3283 logevent("Rejected X11 connect request");
3285 c
= smalloc(sizeof(struct ssh_channel
));
3288 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
3289 ssh
->x11auth
) != NULL
) {
3290 logevent("opening X11 forward connection failed");
3292 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3293 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3297 ("opening X11 forward connection succeeded");
3298 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3299 c
->localid
= alloc_channel_id(ssh
);
3301 c
->v
.v1
.throttling
= 0;
3302 c
->type
= CHAN_X11
; /* identify channel type */
3303 add234(ssh
->channels
, c
);
3304 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3305 PKT_INT
, c
->remoteid
, PKT_INT
,
3306 c
->localid
, PKT_END
);
3307 logevent("Opened X11 forward channel");
3310 } else if (ssh
->pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
3311 /* Remote side is trying to open a channel to talk to our
3312 * agent. Give them back a local channel number. */
3313 struct ssh_channel
*c
;
3315 /* Refuse if agent forwarding is disabled. */
3316 if (!ssh
->agentfwd_enabled
) {
3317 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3318 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3320 c
= smalloc(sizeof(struct ssh_channel
));
3322 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3323 c
->localid
= alloc_channel_id(ssh
);
3325 c
->v
.v1
.throttling
= 0;
3326 c
->type
= CHAN_AGENT
; /* identify channel type */
3327 c
->u
.a
.lensofar
= 0;
3328 add234(ssh
->channels
, c
);
3329 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3330 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
3333 } else if (ssh
->pktin
.type
== SSH1_MSG_PORT_OPEN
) {
3334 /* Remote side is trying to open a channel to talk to a
3335 * forwarded port. Give them back a local channel number. */
3336 struct ssh_channel
*c
;
3337 struct ssh_rportfwd pf
;
3339 char host
[256], buf
[1024];
3341 c
= smalloc(sizeof(struct ssh_channel
));
3344 hostsize
= GET_32BIT(ssh
->pktin
.body
+4);
3345 for(h
= host
, p
= ssh
->pktin
.body
+8; hostsize
!= 0; hostsize
--) {
3346 if (h
+1 < host
+sizeof(host
))
3351 port
= GET_32BIT(p
);
3353 strcpy(pf
.dhost
, host
);
3356 if (find234(ssh
->rportfwds
, &pf
, NULL
) == NULL
) {
3357 sprintf(buf
, "Rejected remote port open request for %s:%d",
3360 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3361 PKT_INT
, GET_32BIT(ssh
->pktin
.body
), PKT_END
);
3363 sprintf(buf
, "Received remote port open request for %s:%d",
3366 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
3369 sprintf(buf
, "Port open failed: %s", e
);
3372 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_FAILURE
,
3373 PKT_INT
, GET_32BIT(ssh
->pktin
.body
),
3376 c
->remoteid
= GET_32BIT(ssh
->pktin
.body
);
3377 c
->localid
= alloc_channel_id(ssh
);
3379 c
->v
.v1
.throttling
= 0;
3380 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
3381 add234(ssh
->channels
, c
);
3382 send_packet(ssh
, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
3383 PKT_INT
, c
->remoteid
, PKT_INT
,
3384 c
->localid
, PKT_END
);
3385 logevent("Forwarded port opened successfully");
3389 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3390 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3391 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3392 struct ssh_channel
*c
;
3394 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3395 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3396 c
->remoteid
= localid
;
3397 c
->type
= CHAN_SOCKDATA
;
3398 c
->v
.v1
.throttling
= 0;
3399 pfd_confirm(c
->u
.pfd
.s
);
3402 if (c
&& c
->closes
) {
3404 * We have a pending close on this channel,
3405 * which we decided on before the server acked
3406 * the channel open. So now we know the
3407 * remoteid, we can close it again.
3409 send_packet(ssh
, SSH1_MSG_CHANNEL_CLOSE
,
3410 PKT_INT
, c
->remoteid
, PKT_END
);
3413 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
3414 unsigned int remoteid
= GET_32BIT(ssh
->pktin
.body
);
3415 unsigned int localid
= GET_32BIT(ssh
->pktin
.body
+4);
3416 struct ssh_channel
*c
;
3418 c
= find234(ssh
->channels
, &remoteid
, ssh_channelfind
);
3419 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
3420 logevent("Forwarded connection refused by server");
3421 pfd_close(c
->u
.pfd
.s
);
3422 del234(ssh
->channels
, c
);
3426 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
3427 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
3428 /* Remote side closes a channel. */
3429 unsigned i
= GET_32BIT(ssh
->pktin
.body
);
3430 struct ssh_channel
*c
;
3431 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3432 if (c
&& ((int)c
->remoteid
) != -1) {
3435 (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
3437 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
3438 logevent("Forwarded X11 connection terminated");
3439 assert(c
->u
.x11
.s
!= NULL
);
3440 x11_close(c
->u
.x11
.s
);
3443 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
3444 logevent("Forwarded port closed");
3445 assert(c
->u
.pfd
.s
!= NULL
);
3446 pfd_close(c
->u
.pfd
.s
);
3450 c
->closes
|= (closetype
<< 2); /* seen this message */
3451 if (!(c
->closes
& closetype
)) {
3452 send_packet(ssh
, ssh
->pktin
.type
, PKT_INT
, c
->remoteid
,
3454 c
->closes
|= closetype
; /* sent it too */
3457 if (c
->closes
== 15) {
3458 del234(ssh
->channels
, c
);
3462 bombout((ssh
,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3463 ssh
->pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
"" :
3464 "_CONFIRMATION", c ?
"half-open" : "nonexistent",
3467 } else if (ssh
->pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
3468 /* Data sent down one of our channels. */
3469 int i
= GET_32BIT(ssh
->pktin
.body
);
3470 int len
= GET_32BIT(ssh
->pktin
.body
+ 4);
3471 unsigned char *p
= ssh
->pktin
.body
+ 8;
3472 struct ssh_channel
*c
;
3473 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
3478 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
3481 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
3484 /* Data for an agent message. Buffer it. */
3486 if (c
->u
.a
.lensofar
< 4) {
3487 int l
= min(4 - c
->u
.a
.lensofar
, len
);
3488 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
3492 c
->u
.a
.lensofar
+= l
;
3494 if (c
->u
.a
.lensofar
== 4) {
3496 4 + GET_32BIT(c
->u
.a
.msglen
);
3497 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3498 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3500 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3502 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3504 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3508 c
->u
.a
.lensofar
+= l
;
3510 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3511 void *reply
, *sentreply
;
3513 agent_query(c
->u
.a
.message
,
3514 c
->u
.a
.totallen
, &reply
,
3519 /* Fake SSH_AGENT_FAILURE. */
3520 sentreply
= "\0\0\0\1\5";
3523 send_packet(ssh
, SSH1_MSG_CHANNEL_DATA
,
3524 PKT_INT
, c
->remoteid
,
3526 PKT_DATA
, sentreply
, replylen
,
3530 sfree(c
->u
.a
.message
);
3531 c
->u
.a
.lensofar
= 0;
3534 bufsize
= 0; /* agent channels never back up */
3537 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3538 c
->v
.v1
.throttling
= 1;
3539 ssh1_throttle(ssh
, +1);
3542 } else if (ssh
->pktin
.type
== SSH1_SMSG_SUCCESS
) {
3543 /* may be from EXEC_SHELL on some servers */
3544 } else if (ssh
->pktin
.type
== SSH1_SMSG_FAILURE
) {
3545 /* may be from EXEC_SHELL on some servers
3546 * if no pty is available or in other odd cases. Ignore */
3547 } else if (ssh
->pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3549 ssh
->exitcode
= GET_32BIT(ssh
->pktin
.body
);
3550 sprintf(buf
, "Server sent command exit status %d",
3553 send_packet(ssh
, SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3555 * In case `helpful' firewalls or proxies tack
3556 * extra human-readable text on the end of the
3557 * session which we might mistake for another
3558 * encrypted packet, we close the session once
3559 * we've sent EXIT_CONFIRMATION.
3561 ssh
->state
= SSH_STATE_CLOSED
;
3564 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
3569 int len
= min(inlen
, 512);
3570 send_packet(ssh
, SSH1_CMSG_STDIN_DATA
,
3571 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3582 * Utility routine for decoding comma-separated strings in KEXINIT.
3584 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3586 int needlen
= strlen(needle
);
3589 * Is it at the start of the string?
3591 if (haylen
>= needlen
&& /* haystack is long enough */
3592 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3593 (haylen
== needlen
|| haystack
[needlen
] == ',')
3594 /* either , or EOS follows */
3598 * If not, search for the next comma and resume after that.
3599 * If no comma found, terminate.
3601 while (haylen
> 0 && *haystack
!= ',')
3602 haylen
--, haystack
++;
3605 haylen
--, haystack
++; /* skip over comma itself */
3610 * SSH2 key creation method.
3612 static void ssh2_mkkey(Ssh ssh
, Bignum K
, char *H
, char *sessid
, char chr
,
3616 /* First 20 bytes. */
3618 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3620 SHA_Bytes(&s
, H
, 20);
3621 SHA_Bytes(&s
, &chr
, 1);
3622 SHA_Bytes(&s
, sessid
, 20);
3623 SHA_Final(&s
, keyspace
);
3624 /* Next 20 bytes. */
3626 if (!(ssh
->remote_bugs
& BUG_SSH2_DERIVEKEY
))
3628 SHA_Bytes(&s
, H
, 20);
3629 SHA_Bytes(&s
, keyspace
, 20);
3630 SHA_Final(&s
, keyspace
+ 20);
3634 * Handle the SSH2 transport layer.
3636 static int do_ssh2_transport(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
3638 struct do_ssh2_transport_state
{
3639 int nbits
, pbits
, warn
;
3640 Bignum p
, g
, e
, f
, K
;
3641 int kex_init_value
, kex_reply_value
;
3642 const struct ssh_mac
**maclist
;
3644 const struct ssh2_cipher
*cscipher_tobe
;
3645 const struct ssh2_cipher
*sccipher_tobe
;
3646 const struct ssh_mac
*csmac_tobe
;
3647 const struct ssh_mac
*scmac_tobe
;
3648 const struct ssh_compress
*cscomp_tobe
;
3649 const struct ssh_compress
*sccomp_tobe
;
3650 char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3651 int hostkeylen
, siglen
;
3652 void *hkey
; /* actual host key */
3653 unsigned char exchange_hash
[20];
3654 int n_preferred_ciphers
;
3655 const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3656 const struct ssh_compress
*preferred_comp
;
3659 crState(do_ssh2_transport_state
);
3661 crBegin(ssh
->do_ssh2_transport_crstate
);
3663 s
->cscipher_tobe
= s
->sccipher_tobe
= NULL
;
3664 s
->csmac_tobe
= s
->scmac_tobe
= NULL
;
3665 s
->cscomp_tobe
= s
->sccomp_tobe
= NULL
;
3673 * Set up the preferred ciphers. (NULL => warn below here)
3675 s
->n_preferred_ciphers
= 0;
3676 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3677 switch (cfg
.ssh_cipherlist
[i
]) {
3678 case CIPHER_BLOWFISH
:
3679 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_blowfish
;
3682 if (cfg
.ssh2_des_cbc
) {
3683 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_des
;
3687 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_3des
;
3690 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = &ssh2_aes
;
3693 /* Flag for later. Don't bother if it's the last in
3695 if (i
< CIPHER_MAX
- 1) {
3696 s
->preferred_ciphers
[s
->n_preferred_ciphers
++] = NULL
;
3704 * Set up preferred compression.
3706 if (cfg
.compression
)
3707 s
->preferred_comp
= &ssh_zlib
;
3709 s
->preferred_comp
= &ssh_comp_none
;
3712 * Be prepared to work around the buggy MAC problem.
3714 if (ssh
->remote_bugs
& BUG_SSH2_HMAC
)
3715 s
->maclist
= buggymacs
, s
->nmacs
= lenof(buggymacs
);
3717 s
->maclist
= macs
, s
->nmacs
= lenof(macs
);
3721 int i
, j
, cipherstr_started
;
3724 * Construct and send our key exchange packet.
3726 ssh2_pkt_init(ssh
, SSH2_MSG_KEXINIT
);
3727 for (i
= 0; i
< 16; i
++)
3728 ssh2_pkt_addbyte(ssh
, (unsigned char) random_byte());
3729 /* List key exchange algorithms. */
3730 ssh2_pkt_addstring_start(ssh
);
3731 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3732 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3733 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3735 ssh2_pkt_addstring_str(ssh
, kex_algs
[i
]->name
);
3736 if (i
< lenof(kex_algs
) - 1)
3737 ssh2_pkt_addstring_str(ssh
, ",");
3739 /* List server host key algorithms. */
3740 ssh2_pkt_addstring_start(ssh
);
3741 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3742 ssh2_pkt_addstring_str(ssh
, hostkey_algs
[i
]->name
);
3743 if (i
< lenof(hostkey_algs
) - 1)
3744 ssh2_pkt_addstring_str(ssh
, ",");
3746 /* List client->server encryption algorithms. */
3747 ssh2_pkt_addstring_start(ssh
);
3748 cipherstr_started
= 0;
3749 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3750 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3751 if (!c
) continue; /* warning flag */
3752 for (j
= 0; j
< c
->nciphers
; j
++) {
3753 if (cipherstr_started
)
3754 ssh2_pkt_addstring_str(ssh
, ",");
3755 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3756 cipherstr_started
= 1;
3759 /* List server->client encryption algorithms. */
3760 ssh2_pkt_addstring_start(ssh
);
3761 cipherstr_started
= 0;
3762 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3763 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3764 if (!c
) continue; /* warning flag */
3765 for (j
= 0; j
< c
->nciphers
; j
++) {
3766 if (cipherstr_started
)
3767 ssh2_pkt_addstring_str(ssh
, ",");
3768 ssh2_pkt_addstring_str(ssh
, c
->list
[j
]->name
);
3769 cipherstr_started
= 1;
3772 /* List client->server MAC algorithms. */
3773 ssh2_pkt_addstring_start(ssh
);
3774 for (i
= 0; i
< s
->nmacs
; i
++) {
3775 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3776 if (i
< s
->nmacs
- 1)
3777 ssh2_pkt_addstring_str(ssh
, ",");
3779 /* List server->client MAC algorithms. */
3780 ssh2_pkt_addstring_start(ssh
);
3781 for (i
= 0; i
< s
->nmacs
; i
++) {
3782 ssh2_pkt_addstring_str(ssh
, s
->maclist
[i
]->name
);
3783 if (i
< s
->nmacs
- 1)
3784 ssh2_pkt_addstring_str(ssh
, ",");
3786 /* List client->server compression algorithms. */
3787 ssh2_pkt_addstring_start(ssh
);
3788 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3789 const struct ssh_compress
*c
=
3790 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3791 ssh2_pkt_addstring_str(ssh
, c
->name
);
3792 if (i
< lenof(compressions
))
3793 ssh2_pkt_addstring_str(ssh
, ",");
3795 /* List server->client compression algorithms. */
3796 ssh2_pkt_addstring_start(ssh
);
3797 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3798 const struct ssh_compress
*c
=
3799 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3800 ssh2_pkt_addstring_str(ssh
, c
->name
);
3801 if (i
< lenof(compressions
))
3802 ssh2_pkt_addstring_str(ssh
, ",");
3804 /* List client->server languages. Empty list. */
3805 ssh2_pkt_addstring_start(ssh
);
3806 /* List server->client languages. Empty list. */
3807 ssh2_pkt_addstring_start(ssh
);
3808 /* First KEX packet does _not_ follow, because we're not that brave. */
3809 ssh2_pkt_addbool(ssh
, FALSE
);
3811 ssh2_pkt_adduint32(ssh
, 0);
3814 ssh
->exhash
= ssh
->exhashbase
;
3815 sha_string(&ssh
->exhash
, ssh
->pktout
.data
+ 5, ssh
->pktout
.length
- 5);
3821 sha_string(&ssh
->exhash
, ssh
->pktin
.data
+ 5, ssh
->pktin
.length
- 5);
3824 * Now examine the other side's KEXINIT to see what we're up
3831 if (ssh
->pktin
.type
!= SSH2_MSG_KEXINIT
) {
3832 bombout((ssh
,"expected key exchange packet from server"));
3836 ssh
->hostkey
= NULL
;
3837 s
->cscipher_tobe
= NULL
;
3838 s
->sccipher_tobe
= NULL
;
3839 s
->csmac_tobe
= NULL
;
3840 s
->scmac_tobe
= NULL
;
3841 s
->cscomp_tobe
= NULL
;
3842 s
->sccomp_tobe
= NULL
;
3843 ssh
->pktin
.savedpos
+= 16; /* skip garbage cookie */
3844 ssh2_pkt_getstring(ssh
, &str
, &len
); /* key exchange algorithms */
3845 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3846 if (kex_algs
[i
] == &ssh_diffiehellman_gex
&&
3847 (ssh
->remote_bugs
& BUG_SSH2_DH_GEX
))
3849 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3850 ssh
->kex
= kex_algs
[i
];
3854 ssh2_pkt_getstring(ssh
, &str
, &len
); /* host key algorithms */
3855 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3856 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3857 ssh
->hostkey
= hostkey_algs
[i
];
3861 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server cipher */
3863 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3864 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3868 for (j
= 0; j
< c
->nciphers
; j
++) {
3869 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3870 s
->cscipher_tobe
= c
->list
[j
];
3875 if (s
->cscipher_tobe
) {
3877 askcipher(ssh
->frontend
, s
->cscipher_tobe
->name
, 1);
3881 if (!s
->cscipher_tobe
) {
3882 bombout((ssh
,"Couldn't agree a client-to-server cipher (available: %s)", str
));
3886 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client cipher */
3888 for (i
= 0; i
< s
->n_preferred_ciphers
; i
++) {
3889 const struct ssh2_ciphers
*c
= s
->preferred_ciphers
[i
];
3893 for (j
= 0; j
< c
->nciphers
; j
++) {
3894 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3895 s
->sccipher_tobe
= c
->list
[j
];
3900 if (s
->sccipher_tobe
) {
3902 askcipher(ssh
->frontend
, s
->sccipher_tobe
->name
, 2);
3906 if (!s
->sccipher_tobe
) {
3907 bombout((ssh
,"Couldn't agree a server-to-client cipher (available: %s)", str
));
3911 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server mac */
3912 for (i
= 0; i
< s
->nmacs
; i
++) {
3913 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3914 s
->csmac_tobe
= s
->maclist
[i
];
3918 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client mac */
3919 for (i
= 0; i
< s
->nmacs
; i
++) {
3920 if (in_commasep_string(s
->maclist
[i
]->name
, str
, len
)) {
3921 s
->scmac_tobe
= s
->maclist
[i
];
3925 ssh2_pkt_getstring(ssh
, &str
, &len
); /* client->server compression */
3926 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3927 const struct ssh_compress
*c
=
3928 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3929 if (in_commasep_string(c
->name
, str
, len
)) {
3934 ssh2_pkt_getstring(ssh
, &str
, &len
); /* server->client compression */
3935 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3936 const struct ssh_compress
*c
=
3937 i
== 0 ? s
->preferred_comp
: compressions
[i
- 1];
3938 if (in_commasep_string(c
->name
, str
, len
)) {
3946 * Work out the number of bits of key we will need from the key
3947 * exchange. We start with the maximum key length of either
3953 csbits
= s
->cscipher_tobe
->keylen
;
3954 scbits
= s
->sccipher_tobe
->keylen
;
3955 s
->nbits
= (csbits
> scbits ? csbits
: scbits
);
3957 /* The keys only have 160-bit entropy, since they're based on
3958 * a SHA-1 hash. So cap the key size at 160 bits. */
3963 * If we're doing Diffie-Hellman group exchange, start by
3964 * requesting a group.
3966 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
3967 logevent("Doing Diffie-Hellman group exchange");
3968 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGEX
;
3970 * Work out how big a DH group we will need to allow that
3973 s
->pbits
= 512 << ((s
->nbits
- 1) / 64);
3974 ssh2_pkt_init(ssh
, SSH2_MSG_KEX_DH_GEX_REQUEST
);
3975 ssh2_pkt_adduint32(ssh
, s
->pbits
);
3979 if (ssh
->pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3980 bombout((ssh
,"expected key exchange group packet from server"));
3983 s
->p
= ssh2_pkt_getmp(ssh
);
3984 s
->g
= ssh2_pkt_getmp(ssh
);
3985 ssh
->kex_ctx
= dh_setup_group(s
->p
, s
->g
);
3986 s
->kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3987 s
->kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3989 ssh
->pkt_ctx
|= SSH2_PKTCTX_DHGROUP1
;
3990 ssh
->kex_ctx
= dh_setup_group1();
3991 s
->kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3992 s
->kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3995 logevent("Doing Diffie-Hellman key exchange");
3997 * Now generate and send e for Diffie-Hellman.
3999 s
->e
= dh_create_e(ssh
->kex_ctx
, s
->nbits
* 2);
4000 ssh2_pkt_init(ssh
, s
->kex_init_value
);
4001 ssh2_pkt_addmp(ssh
, s
->e
);
4005 if (ssh
->pktin
.type
!= s
->kex_reply_value
) {
4006 bombout((ssh
,"expected key exchange reply packet from server"));
4009 ssh2_pkt_getstring(ssh
, &s
->hostkeydata
, &s
->hostkeylen
);
4010 s
->f
= ssh2_pkt_getmp(ssh
);
4011 ssh2_pkt_getstring(ssh
, &s
->sigdata
, &s
->siglen
);
4013 s
->K
= dh_find_K(ssh
->kex_ctx
, s
->f
);
4015 sha_string(&ssh
->exhash
, s
->hostkeydata
, s
->hostkeylen
);
4016 if (ssh
->kex
== &ssh_diffiehellman_gex
) {
4017 sha_uint32(&ssh
->exhash
, s
->pbits
);
4018 sha_mpint(&ssh
->exhash
, s
->p
);
4019 sha_mpint(&ssh
->exhash
, s
->g
);
4021 sha_mpint(&ssh
->exhash
, s
->e
);
4022 sha_mpint(&ssh
->exhash
, s
->f
);
4023 sha_mpint(&ssh
->exhash
, s
->K
);
4024 SHA_Final(&ssh
->exhash
, s
->exchange_hash
);
4026 dh_cleanup(ssh
->kex_ctx
);
4029 debug(("Exchange hash is:\n"));
4030 dmemdump(s
->exchange_hash
, 20);
4033 s
->hkey
= ssh
->hostkey
->newkey(s
->hostkeydata
, s
->hostkeylen
);
4035 !ssh
->hostkey
->verifysig(s
->hkey
, s
->sigdata
, s
->siglen
,
4036 s
->exchange_hash
, 20)) {
4037 bombout((ssh
,"Server's host key did not match the signature supplied"));
4042 * Authenticate remote host: verify host key. (We've already
4043 * checked the signature of the exchange hash.)
4045 s
->keystr
= ssh
->hostkey
->fmtkey(s
->hkey
);
4046 s
->fingerprint
= ssh
->hostkey
->fingerprint(s
->hkey
);
4047 verify_ssh_host_key(ssh
->frontend
,
4048 ssh
->savedhost
, ssh
->savedport
, ssh
->hostkey
->keytype
,
4049 s
->keystr
, s
->fingerprint
);
4050 if (s
->first_kex
) { /* don't bother logging this in rekeys */
4051 logevent("Host key fingerprint is:");
4052 logevent(s
->fingerprint
);
4054 sfree(s
->fingerprint
);
4056 ssh
->hostkey
->freekey(s
->hkey
);
4059 * Send SSH2_MSG_NEWKEYS.
4061 ssh2_pkt_init(ssh
, SSH2_MSG_NEWKEYS
);
4065 * Expect SSH2_MSG_NEWKEYS from server.
4068 if (ssh
->pktin
.type
!= SSH2_MSG_NEWKEYS
) {
4069 bombout((ssh
,"expected new-keys packet from server"));
4074 * Create and initialise session keys.
4076 if (ssh
->cs_cipher_ctx
)
4077 ssh
->cscipher
->free_context(ssh
->cs_cipher_ctx
);
4078 ssh
->cscipher
= s
->cscipher_tobe
;
4079 ssh
->cs_cipher_ctx
= ssh
->cscipher
->make_context();
4081 if (ssh
->sc_cipher_ctx
)
4082 ssh
->sccipher
->free_context(ssh
->sc_cipher_ctx
);
4083 ssh
->sccipher
= s
->sccipher_tobe
;
4084 ssh
->sc_cipher_ctx
= ssh
->sccipher
->make_context();
4086 if (ssh
->cs_mac_ctx
)
4087 ssh
->csmac
->free_context(ssh
->cs_mac_ctx
);
4088 ssh
->csmac
= s
->csmac_tobe
;
4089 ssh
->cs_mac_ctx
= ssh
->csmac
->make_context();
4091 if (ssh
->sc_mac_ctx
)
4092 ssh
->scmac
->free_context(ssh
->sc_mac_ctx
);
4093 ssh
->scmac
= s
->scmac_tobe
;
4094 ssh
->sc_mac_ctx
= ssh
->scmac
->make_context();
4096 if (ssh
->cs_comp_ctx
)
4097 ssh
->cscomp
->compress_cleanup(ssh
->cs_comp_ctx
);
4098 ssh
->cscomp
= s
->cscomp_tobe
;
4099 ssh
->cs_comp_ctx
= ssh
->cscomp
->compress_init();
4101 if (ssh
->sc_comp_ctx
)
4102 ssh
->sccomp
->decompress_cleanup(ssh
->sc_comp_ctx
);
4103 ssh
->sccomp
= s
->sccomp_tobe
;
4104 ssh
->sc_comp_ctx
= ssh
->sccomp
->decompress_init();
4107 * Set IVs after keys. Here we use the exchange hash from the
4108 * _first_ key exchange.
4111 unsigned char keyspace
[40];
4113 memcpy(ssh
->v2_session_id
, s
->exchange_hash
,
4114 sizeof(s
->exchange_hash
));
4115 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'C',keyspace
);
4116 ssh
->cscipher
->setkey(ssh
->cs_cipher_ctx
, keyspace
);
4117 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'D',keyspace
);
4118 ssh
->sccipher
->setkey(ssh
->sc_cipher_ctx
, keyspace
);
4119 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'A',keyspace
);
4120 ssh
->cscipher
->setiv(ssh
->cs_cipher_ctx
, keyspace
);
4121 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'B',keyspace
);
4122 ssh
->sccipher
->setiv(ssh
->sc_cipher_ctx
, keyspace
);
4123 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'E',keyspace
);
4124 ssh
->csmac
->setkey(ssh
->cs_mac_ctx
, keyspace
);
4125 ssh2_mkkey(ssh
,s
->K
,s
->exchange_hash
,ssh
->v2_session_id
,'F',keyspace
);
4126 ssh
->scmac
->setkey(ssh
->sc_mac_ctx
, keyspace
);
4130 sprintf(buf
, "Initialised %.200s client->server encryption",
4131 ssh
->cscipher
->text_name
);
4133 sprintf(buf
, "Initialised %.200s server->client encryption",
4134 ssh
->sccipher
->text_name
);
4136 if (ssh
->cscomp
->text_name
) {
4137 sprintf(buf
, "Initialised %.200s compression",
4138 ssh
->cscomp
->text_name
);
4141 if (ssh
->sccomp
->text_name
) {
4142 sprintf(buf
, "Initialised %.200s decompression",
4143 ssh
->sccomp
->text_name
);
4150 * If this is the first key exchange phase, we must pass the
4151 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4152 * wants to see it but because it will need time to initialise
4153 * itself before it sees an actual packet. In subsequent key
4154 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4155 * it would only confuse the layer above.
4157 if (!s
->first_kex
) {
4163 * Now we're encrypting. Begin returning 1 to the protocol main
4164 * function so that other things can run on top of the
4165 * transport. If we ever see a KEXINIT, we must go back to the
4168 while (!(ispkt
&& ssh
->pktin
.type
== SSH2_MSG_KEXINIT
)) {
4171 logevent("Server initiated key re-exchange");
4172 goto begin_key_exchange
;
4178 * Add data to an SSH2 channel output buffer.
4180 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
4183 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
4187 * Attempt to send data on an SSH2 channel.
4189 static int ssh2_try_send(struct ssh_channel
*c
)
4193 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
4196 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
4197 if ((unsigned)len
> c
->v
.v2
.remwindow
)
4198 len
= c
->v
.v2
.remwindow
;
4199 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
4200 len
= c
->v
.v2
.remmaxpkt
;
4201 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_DATA
);
4202 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4203 ssh2_pkt_addstring_start(ssh
);
4204 ssh2_pkt_addstring_data(ssh
, data
, len
);
4206 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
4207 c
->v
.v2
.remwindow
-= len
;
4211 * After having sent as much data as we can, return the amount
4214 return bufchain_size(&c
->v
.v2
.outbuffer
);
4218 * Potentially enlarge the window on an SSH2 channel.
4220 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
4225 * Never send WINDOW_ADJUST for a channel that the remote side
4226 * already thinks it's closed; there's no point, since it won't
4227 * be sending any more data anyway.
4232 if (newwin
> c
->v
.v2
.locwindow
) {
4233 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4234 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
4235 ssh2_pkt_adduint32(ssh
, newwin
- c
->v
.v2
.locwindow
);
4237 c
->v
.v2
.locwindow
= newwin
;
4242 * Handle the SSH2 userauth and connection layers.
4244 static void do_ssh2_authconn(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
4246 struct do_ssh2_authconn_state
{
4248 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
4250 AUTH_KEYBOARD_INTERACTIVE
4254 AUTH_TYPE_PUBLICKEY
,
4255 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
4256 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
4258 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
4259 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4261 int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
4262 int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
4263 int kbd_inter_running
;
4265 int num_prompts
, curr_prompt
, echo
;
4270 void *publickey_blob
;
4271 int publickey_bloblen
;
4272 unsigned char request
[5], *response
, *p
;
4276 char *pkblob
, *alg
, *commentp
;
4277 int pklen
, alglen
, commentlen
;
4278 int siglen
, retlen
, len
;
4279 char *q
, *agentreq
, *ret
;
4282 crState(do_ssh2_authconn_state
);
4284 crBegin(ssh
->do_ssh2_authconn_crstate
);
4287 * Request userauth protocol, and await a response to it.
4289 ssh2_pkt_init(ssh
, SSH2_MSG_SERVICE_REQUEST
);
4290 ssh2_pkt_addstring(ssh
, "ssh-userauth");
4292 crWaitUntilV(ispkt
);
4293 if (ssh
->pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
4294 bombout((ssh
,"Server refused user authentication protocol"));
4299 * We repeat this whole loop, including the username prompt,
4300 * until we manage a successful authentication. If the user
4301 * types the wrong _password_, they can be sent back to the
4302 * beginning to try another username, if this is configured on.
4303 * (If they specify a username in the config, they are never
4304 * asked, even if they do give a wrong password.)
4306 * I think this best serves the needs of
4308 * - the people who have no configuration, no keys, and just
4309 * want to try repeated (username,password) pairs until they
4310 * type both correctly
4312 * - people who have keys and configuration but occasionally
4313 * need to fall back to passwords
4315 * - people with a key held in Pageant, who might not have
4316 * logged in to a particular machine before; so they want to
4317 * type a username, and then _either_ their key will be
4318 * accepted, _or_ they will type a password. If they mistype
4319 * the username they will want to be able to get back and
4322 s
->username
[0] = '\0';
4323 s
->got_username
= FALSE
;
4328 if (s
->got_username
&& !cfg
.change_username
) {
4330 * We got a username last time round this loop, and
4331 * with change_username turned off we don't try to get
4334 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
4335 if (ssh_get_line
&& !ssh_getline_pw_only
) {
4336 if (!ssh_get_line("login as: ",
4337 s
->username
, sizeof(s
->username
), FALSE
)) {
4339 * get_line failed to get a username.
4342 logevent("No username provided. Abandoning session.");
4343 ssh
->state
= SSH_STATE_CLOSED
;
4347 int ret
; /* need not be saved across crReturn */
4348 c_write_str(ssh
, "login as: ");
4350 setup_userpass_input(ssh
, s
->username
, sizeof(s
->username
), 1);
4352 crWaitUntilV(!ispkt
);
4353 ret
= process_userpass_input(ssh
, in
, inlen
);
4358 c_write_str(ssh
, "\r\n");
4359 s
->username
[strcspn(s
->username
, "\n\r")] = '\0';
4362 strncpy(s
->username
, cfg
.username
, sizeof(s
->username
));
4363 s
->username
[sizeof(s
->username
)-1] = '\0';
4364 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
4365 sprintf(stuff
, "Using username \"%s\".\r\n", s
->username
);
4366 c_write_str(ssh
, stuff
);
4369 s
->got_username
= TRUE
;
4372 * Send an authentication request using method "none": (a)
4373 * just in case it succeeds, and (b) so that we know what
4374 * authentication methods we can usefully try next.
4376 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4378 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4379 ssh2_pkt_addstring(ssh
, s
->username
);
4380 ssh2_pkt_addstring(ssh
, "ssh-connection");/* service requested */
4381 ssh2_pkt_addstring(ssh
, "none"); /* method */
4383 s
->type
= AUTH_TYPE_NONE
;
4385 s
->we_are_in
= FALSE
;
4387 s
->tried_pubkey_config
= FALSE
;
4388 s
->tried_agent
= FALSE
;
4389 s
->tried_keyb_inter
= FALSE
;
4390 s
->kbd_inter_running
= FALSE
;
4391 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4394 logeventf(ssh
->frontend
,
4395 "Reading private key file \"%.150s\"", cfg
.keyfile
);
4396 keytype
= key_type(cfg
.keyfile
);
4397 if (keytype
== SSH_KEYTYPE_SSH2
) {
4399 ssh2_userkey_loadpub(cfg
.keyfile
, NULL
,
4400 &s
->publickey_bloblen
);
4403 logeventf(ssh
->frontend
,
4404 "Unable to use this key file (%s)",
4405 key_type_to_str(keytype
));
4406 sprintf(msgbuf
, "Unable to use key file \"%.150s\" (%s)\r\n",
4407 cfg
.keyfile
, key_type_to_str(keytype
));
4408 c_write_str(ssh
, msgbuf
);
4409 s
->publickey_blob
= NULL
;
4412 s
->publickey_blob
= NULL
;
4416 * Wait for the result of the last authentication request.
4419 crWaitUntilV(ispkt
);
4420 while (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
4424 * Don't show the banner if we're operating in
4425 * non-verbose non-interactive mode. (It's probably
4426 * a script, which means nobody will read the
4427 * banner _anyway_, and moreover the printing of
4428 * the banner will screw up processing on the
4429 * output of (say) plink.)
4431 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
4432 ssh2_pkt_getstring(ssh
, &banner
, &size
);
4434 c_write_untrusted(ssh
, banner
, size
);
4436 crWaitUntilV(ispkt
);
4438 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
4439 logevent("Access granted");
4440 s
->we_are_in
= TRUE
;
4444 if (s
->kbd_inter_running
&&
4445 ssh
->pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4447 * This is either a further set-of-prompts packet
4448 * in keyboard-interactive authentication, or it's
4449 * the same one and we came back here with `gotit'
4450 * set. In the former case, we must reset the
4451 * curr_prompt variable.
4455 } else if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
4456 bombout((ssh
,"Strange packet received during authentication: type %d",
4464 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4465 * we can look at the string in it and know what we can
4466 * helpfully try next.
4468 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
4471 ssh2_pkt_getstring(ssh
, &methods
, &methlen
);
4472 s
->kbd_inter_running
= FALSE
;
4473 if (!ssh2_pkt_getbool(ssh
)) {
4475 * We have received an unequivocal Access
4476 * Denied. This can translate to a variety of
4479 * - if we'd just tried "none" authentication,
4480 * it's not worth printing anything at all
4482 * - if we'd just tried a public key _offer_,
4483 * the message should be "Server refused our
4484 * key" (or no message at all if the key
4485 * came from Pageant)
4487 * - if we'd just tried anything else, the
4488 * message really should be "Access denied".
4490 * Additionally, if we'd just tried password
4491 * authentication, we should break out of this
4492 * whole loop so as to go back to the username
4495 if (s
->type
== AUTH_TYPE_NONE
) {
4497 } else if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
4498 s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
4499 if (s
->type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
4500 c_write_str(ssh
, "Server refused our key\r\n");
4501 logevent("Server refused public key");
4502 } else if (s
->type
==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
4503 /* server declined keyboard-interactive; ignore */
4505 c_write_str(ssh
, "Access denied\r\n");
4506 logevent("Access denied");
4507 if (s
->type
== AUTH_TYPE_PASSWORD
) {
4508 s
->we_are_in
= FALSE
;
4513 c_write_str(ssh
, "Further authentication required\r\n");
4514 logevent("Further authentication required");
4518 in_commasep_string("publickey", methods
, methlen
);
4520 in_commasep_string("password", methods
, methlen
);
4521 s
->can_keyb_inter
= cfg
.try_ki_auth
&&
4522 in_commasep_string("keyboard-interactive", methods
, methlen
);
4526 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4529 * Most password/passphrase prompts will be
4530 * non-echoing, so we set this to 0 by default.
4531 * Exception is that some keyboard-interactive prompts
4532 * can be echoing, in which case we'll set this to 1.
4536 if (!s
->method
&& s
->can_pubkey
&&
4537 agent_exists() && !s
->tried_agent
) {
4539 * Attempt public-key authentication using Pageant.
4544 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4545 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4547 s
->tried_agent
= TRUE
;
4549 logevent("Pageant is running. Requesting keys.");
4551 /* Request the keys held by the agent. */
4552 PUT_32BIT(s
->request
, 1);
4553 s
->request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
4554 agent_query(s
->request
, 5, &r
, &s
->responselen
);
4555 s
->response
= (unsigned char *) r
;
4556 if (s
->response
&& s
->responselen
>= 5 &&
4557 s
->response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
4558 s
->p
= s
->response
+ 5;
4559 s
->nkeys
= GET_32BIT(s
->p
);
4563 sprintf(buf
, "Pageant has %d SSH2 keys", s
->nkeys
);
4566 for (s
->keyi
= 0; s
->keyi
< s
->nkeys
; s
->keyi
++) {
4571 sprintf(buf
, "Trying Pageant key #%d", s
->keyi
);
4574 s
->pklen
= GET_32BIT(s
->p
);
4576 if (s
->publickey_blob
&&
4577 s
->pklen
== s
->publickey_bloblen
&&
4578 !memcmp(s
->p
, s
->publickey_blob
,
4579 s
->publickey_bloblen
)) {
4580 logevent("This key matches configured key file");
4581 s
->tried_pubkey_config
= 1;
4585 s
->alglen
= GET_32BIT(s
->pkblob
);
4586 s
->alg
= s
->pkblob
+ 4;
4587 s
->commentlen
= GET_32BIT(s
->p
);
4590 s
->p
+= s
->commentlen
;
4591 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4592 ssh2_pkt_addstring(ssh
, s
->username
);
4593 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4594 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4595 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4596 ssh2_pkt_addstring_start(ssh
);
4597 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4598 ssh2_pkt_addstring_start(ssh
);
4599 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4602 crWaitUntilV(ispkt
);
4603 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4604 logevent("Key refused");
4608 if (flags
& FLAG_VERBOSE
) {
4609 c_write_str(ssh
, "Authenticating with "
4611 c_write(ssh
, s
->commentp
, s
->commentlen
);
4612 c_write_str(ssh
, "\" from agent\r\n");
4616 * Server is willing to accept the key.
4617 * Construct a SIGN_REQUEST.
4619 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4620 ssh2_pkt_addstring(ssh
, s
->username
);
4621 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4622 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4623 ssh2_pkt_addbool(ssh
, TRUE
);
4624 ssh2_pkt_addstring_start(ssh
);
4625 ssh2_pkt_addstring_data(ssh
, s
->alg
, s
->alglen
);
4626 ssh2_pkt_addstring_start(ssh
);
4627 ssh2_pkt_addstring_data(ssh
, s
->pkblob
, s
->pklen
);
4629 s
->siglen
= ssh
->pktout
.length
- 5 + 4 + 20;
4630 s
->len
= 1; /* message type */
4631 s
->len
+= 4 + s
->pklen
; /* key blob */
4632 s
->len
+= 4 + s
->siglen
; /* data to sign */
4633 s
->len
+= 4; /* flags */
4634 s
->agentreq
= smalloc(4 + s
->len
);
4635 PUT_32BIT(s
->agentreq
, s
->len
);
4636 s
->q
= s
->agentreq
+ 4;
4637 *s
->q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4638 PUT_32BIT(s
->q
, s
->pklen
);
4640 memcpy(s
->q
, s
->pkblob
, s
->pklen
);
4642 PUT_32BIT(s
->q
, s
->siglen
);
4644 /* Now the data to be signed... */
4645 PUT_32BIT(s
->q
, 20);
4647 memcpy(s
->q
, ssh
->v2_session_id
, 20);
4649 memcpy(s
->q
, ssh
->pktout
.data
+ 5,
4650 ssh
->pktout
.length
- 5);
4651 s
->q
+= ssh
->pktout
.length
- 5;
4652 /* And finally the (zero) flags word. */
4654 agent_query(s
->agentreq
, s
->len
+ 4, &vret
, &s
->retlen
);
4658 if (s
->ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4659 logevent("Sending Pageant's response");
4660 ssh2_add_sigblob(ssh
, s
->pkblob
, s
->pklen
,
4662 GET_32BIT(s
->ret
+ 5));
4668 ("Pageant failed to answer challenge");
4678 if (!s
->method
&& s
->can_pubkey
&& s
->publickey_blob
4679 && !s
->tried_pubkey_config
) {
4680 unsigned char *pub_blob
;
4681 char *algorithm
, *comment
;
4684 s
->tried_pubkey_config
= TRUE
;
4686 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4687 ssh
->pkt_ctx
|= SSH2_PKTCTX_PUBLICKEY
;
4690 * Try the public key supplied in the configuration.
4692 * First, offer the public blob to see if the server is
4693 * willing to accept it.
4695 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4698 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4699 ssh2_pkt_addstring(ssh
, s
->username
);
4700 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4701 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4702 ssh2_pkt_addbool(ssh
, FALSE
); /* no signature included */
4703 ssh2_pkt_addstring(ssh
, algorithm
);
4704 ssh2_pkt_addstring_start(ssh
);
4705 ssh2_pkt_addstring_data(ssh
, pub_blob
, pub_blob_len
);
4707 logevent("Offered public key"); /* FIXME */
4709 crWaitUntilV(ispkt
);
4710 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4712 s
->type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4713 continue; /* key refused; give up on it */
4716 logevent("Offer of public key accepted");
4718 * Actually attempt a serious authentication using
4721 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4722 sprintf(s
->pwprompt
,
4723 "Passphrase for key \"%.100s\": ",
4729 c_write_str(ssh
, "Authenticating with public key \"");
4730 c_write_str(ssh
, comment
);
4731 c_write_str(ssh
, "\"\r\n");
4732 s
->method
= AUTH_PUBLICKEY_FILE
;
4736 if (!s
->method
&& s
->can_keyb_inter
&& !s
->tried_keyb_inter
) {
4737 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4738 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4739 s
->tried_keyb_inter
= TRUE
;
4741 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4742 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4744 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4745 ssh2_pkt_addstring(ssh
, s
->username
);
4746 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4747 ssh2_pkt_addstring(ssh
, "keyboard-interactive"); /* method */
4748 ssh2_pkt_addstring(ssh
, ""); /* lang */
4749 ssh2_pkt_addstring(ssh
, "");
4752 crWaitUntilV(ispkt
);
4753 if (ssh
->pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4754 if (ssh
->pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4756 logevent("Keyboard-interactive authentication refused");
4757 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4761 s
->kbd_inter_running
= TRUE
;
4765 if (s
->kbd_inter_running
) {
4766 s
->method
= AUTH_KEYBOARD_INTERACTIVE
;
4767 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4768 s
->tried_keyb_inter
= TRUE
;
4770 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4771 ssh
->pkt_ctx
|= SSH2_PKTCTX_KBDINTER
;
4773 if (s
->curr_prompt
== 0) {
4775 * We've got a fresh USERAUTH_INFO_REQUEST.
4776 * Display header data, and start going through
4779 char *name
, *inst
, *lang
;
4780 int name_len
, inst_len
, lang_len
;
4782 ssh2_pkt_getstring(ssh
, &name
, &name_len
);
4783 ssh2_pkt_getstring(ssh
, &inst
, &inst_len
);
4784 ssh2_pkt_getstring(ssh
, &lang
, &lang_len
);
4786 c_write_untrusted(ssh
, name
, name_len
);
4787 c_write_str(ssh
, "\r\n");
4790 c_write_untrusted(ssh
, inst
, inst_len
);
4791 c_write_str(ssh
, "\r\n");
4793 s
->num_prompts
= ssh2_pkt_getuint32(ssh
);
4797 * If there are prompts remaining in the packet,
4798 * display one and get a response.
4800 if (s
->curr_prompt
< s
->num_prompts
) {
4804 ssh2_pkt_getstring(ssh
, &prompt
, &prompt_len
);
4805 if (prompt_len
> 0) {
4806 strncpy(s
->pwprompt
, prompt
, sizeof(s
->pwprompt
));
4807 s
->pwprompt
[prompt_len
< sizeof(s
->pwprompt
) ?
4808 prompt_len
: sizeof(s
->pwprompt
)-1] = '\0';
4811 "<server failed to send prompt>: ");
4813 s
->echo
= ssh2_pkt_getbool(ssh
);
4819 if (!s
->method
&& s
->can_passwd
) {
4820 s
->method
= AUTH_PASSWORD
;
4821 ssh
->pkt_ctx
&= ~SSH2_PKTCTX_AUTH_MASK
;
4822 ssh
->pkt_ctx
|= SSH2_PKTCTX_PASSWORD
;
4823 sprintf(s
->pwprompt
, "%.90s@%.90s's password: ", s
->username
,
4830 if (!ssh_get_line(s
->pwprompt
, s
->password
,
4831 sizeof(s
->password
), TRUE
)) {
4833 * get_line failed to get a password (for
4834 * example because one was supplied on the
4835 * command line which has already failed to
4838 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
4839 ssh2_pkt_adduint32(ssh
,SSH2_DISCONNECT_BY_APPLICATION
);
4840 ssh2_pkt_addstring(ssh
, "No more passwords available"
4842 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
4844 logevent("Unable to authenticate");
4845 connection_fatal(ssh
->frontend
,
4846 "Unable to authenticate");
4847 ssh
->state
= SSH_STATE_CLOSED
;
4851 int ret
; /* need not be saved across crReturn */
4852 c_write_untrusted(ssh
, s
->pwprompt
, strlen(s
->pwprompt
));
4855 setup_userpass_input(ssh
, s
->password
,
4856 sizeof(s
->password
), s
->echo
);
4858 crWaitUntilV(!ispkt
);
4859 ret
= process_userpass_input(ssh
, in
, inlen
);
4863 c_write_str(ssh
, "\r\n");
4867 if (s
->method
== AUTH_PUBLICKEY_FILE
) {
4869 * We have our passphrase. Now try the actual authentication.
4871 struct ssh2_userkey
*key
;
4873 key
= ssh2_load_userkey(cfg
.keyfile
, s
->password
);
4874 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4875 if (key
== SSH2_WRONG_PASSPHRASE
) {
4876 c_write_str(ssh
, "Wrong passphrase\r\n");
4877 s
->tried_pubkey_config
= FALSE
;
4879 c_write_str(ssh
, "Unable to load private key\r\n");
4880 s
->tried_pubkey_config
= TRUE
;
4882 /* Send a spurious AUTH_NONE to return to the top. */
4883 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4884 ssh2_pkt_addstring(ssh
, s
->username
);
4885 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4886 ssh2_pkt_addstring(ssh
, "none"); /* method */
4888 s
->type
= AUTH_TYPE_NONE
;
4890 unsigned char *pkblob
, *sigblob
, *sigdata
;
4891 int pkblob_len
, sigblob_len
, sigdata_len
;
4894 * We have loaded the private key and the server
4895 * has announced that it's willing to accept it.
4896 * Hallelujah. Generate a signature and send it.
4898 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4899 ssh2_pkt_addstring(ssh
, s
->username
);
4900 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4901 ssh2_pkt_addstring(ssh
, "publickey"); /* method */
4902 ssh2_pkt_addbool(ssh
, TRUE
);
4903 ssh2_pkt_addstring(ssh
, key
->alg
->name
);
4904 pkblob
= key
->alg
->public_blob(key
->data
, &pkblob_len
);
4905 ssh2_pkt_addstring_start(ssh
);
4906 ssh2_pkt_addstring_data(ssh
, pkblob
, pkblob_len
);
4909 * The data to be signed is:
4913 * followed by everything so far placed in the
4916 sigdata_len
= ssh
->pktout
.length
- 5 + 4 + 20;
4917 sigdata
= smalloc(sigdata_len
);
4918 PUT_32BIT(sigdata
, 20);
4919 memcpy(sigdata
+ 4, ssh
->v2_session_id
, 20);
4920 memcpy(sigdata
+ 24, ssh
->pktout
.data
+ 5,
4921 ssh
->pktout
.length
- 5);
4922 sigblob
= key
->alg
->sign(key
->data
, sigdata
,
4923 sigdata_len
, &sigblob_len
);
4924 ssh2_add_sigblob(ssh
, pkblob
, pkblob_len
,
4925 sigblob
, sigblob_len
);
4931 s
->type
= AUTH_TYPE_PUBLICKEY
;
4933 } else if (s
->method
== AUTH_PASSWORD
) {
4935 * We send the password packet lumped tightly together with
4936 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4937 * string long enough to make the total length of the two
4938 * packets constant. This should ensure that a passive
4939 * listener doing traffic analyis can't work out the length
4942 * For this to work, we need an assumption about the
4943 * maximum length of the password packet. I think 256 is
4944 * pretty conservative. Anyone using a password longer than
4945 * that probably doesn't have much to worry about from
4946 * people who find out how long their password is!
4948 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_REQUEST
);
4949 ssh2_pkt_addstring(ssh
, s
->username
);
4950 ssh2_pkt_addstring(ssh
, "ssh-connection"); /* service requested */
4951 ssh2_pkt_addstring(ssh
, "password");
4952 ssh2_pkt_addbool(ssh
, FALSE
);
4953 ssh2_pkt_addstring(ssh
, s
->password
);
4954 ssh2_pkt_defer(ssh
);
4956 * We'll include a string that's an exact multiple of the
4957 * cipher block size. If the cipher is NULL for some
4958 * reason, we don't do this trick at all because we gain
4961 if (ssh
->cscipher
) {
4964 stringlen
= (256 - ssh
->deferred_len
);
4965 stringlen
+= ssh
->cscipher
->blksize
- 1;
4966 stringlen
-= (stringlen
% ssh
->cscipher
->blksize
);
4969 * Temporarily disable actual compression,
4970 * so we can guarantee to get this string
4971 * exactly the length we want it. The
4972 * compression-disabling routine should
4973 * return an integer indicating how many
4974 * bytes we should adjust our string length
4978 ssh
->cscomp
->disable_compression(ssh
->cs_comp_ctx
);
4980 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
4981 ssh2_pkt_addstring_start(ssh
);
4982 for (i
= 0; i
< stringlen
; i
++) {
4983 char c
= (char) random_byte();
4984 ssh2_pkt_addstring_data(ssh
, &c
, 1);
4986 ssh2_pkt_defer(ssh
);
4988 ssh_pkt_defersend(ssh
);
4989 logevent("Sent password");
4990 s
->type
= AUTH_TYPE_PASSWORD
;
4991 } else if (s
->method
== AUTH_KEYBOARD_INTERACTIVE
) {
4992 if (s
->curr_prompt
== 0) {
4993 ssh2_pkt_init(ssh
, SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4994 ssh2_pkt_adduint32(ssh
, s
->num_prompts
);
4996 if (s
->need_pw
) { /* only add pw if we just got one! */
4997 ssh2_pkt_addstring(ssh
, s
->password
);
4998 memset(s
->password
, 0, sizeof(s
->password
));
5001 if (s
->curr_prompt
>= s
->num_prompts
) {
5005 * If there are prompts remaining, we set
5006 * `gotit' so that we won't attempt to get
5007 * another packet. Then we go back round the
5008 * loop and will end up retrieving another
5009 * prompt out of the existing packet. Funky or
5014 s
->type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
5016 c_write_str(ssh
, "No supported authentication methods"
5017 " left to try!\r\n");
5018 logevent("No supported authentications offered."
5020 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5021 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5022 ssh2_pkt_addstring(ssh
, "No supported authentication"
5023 " methods available");
5024 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5026 ssh
->state
= SSH_STATE_CLOSED
;
5030 } while (!s
->we_are_in
);
5033 * Now we're authenticated for the connection protocol. The
5034 * connection protocol will automatically have started at this
5035 * point; there's no need to send SERVICE_REQUEST.
5039 * So now create a channel with a session in it.
5041 ssh
->channels
= newtree234(ssh_channelcmp
);
5042 ssh
->mainchan
= smalloc(sizeof(struct ssh_channel
));
5043 ssh
->mainchan
->ssh
= ssh
;
5044 ssh
->mainchan
->localid
= alloc_channel_id(ssh
);
5045 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
5046 ssh2_pkt_addstring(ssh
, "session");
5047 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->localid
);
5048 ssh
->mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5049 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->v
.v2
.locwindow
);/* our window size */
5050 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5052 crWaitUntilV(ispkt
);
5053 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5054 bombout((ssh
,"Server refused to open a session"));
5056 /* FIXME: error data comes back in FAILURE packet */
5058 if (ssh2_pkt_getuint32(ssh
) != ssh
->mainchan
->localid
) {
5059 bombout((ssh
,"Server's channel confirmation cited wrong channel"));
5062 ssh
->mainchan
->remoteid
= ssh2_pkt_getuint32(ssh
);
5063 ssh
->mainchan
->type
= CHAN_MAINSESSION
;
5064 ssh
->mainchan
->closes
= 0;
5065 ssh
->mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5066 ssh
->mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5067 bufchain_init(&ssh
->mainchan
->v
.v2
.outbuffer
);
5068 add234(ssh
->channels
, ssh
->mainchan
);
5069 logevent("Opened channel for session");
5072 * Potentially enable X11 forwarding.
5074 if (cfg
.x11_forward
) {
5075 char proto
[20], data
[64];
5076 logevent("Requesting X11 forwarding");
5077 ssh
->x11auth
= x11_invent_auth(proto
, sizeof(proto
),
5078 data
, sizeof(data
));
5079 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5080 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5081 ssh2_pkt_addstring(ssh
, "x11-req");
5082 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5083 ssh2_pkt_addbool(ssh
, 0); /* many connections */
5084 ssh2_pkt_addstring(ssh
, proto
);
5085 ssh2_pkt_addstring(ssh
, data
);
5086 ssh2_pkt_adduint32(ssh
, 0); /* screen number */
5090 crWaitUntilV(ispkt
);
5091 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5092 unsigned i
= ssh2_pkt_getuint32(ssh
);
5093 struct ssh_channel
*c
;
5094 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5096 continue; /* nonexistent channel */
5097 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5099 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5101 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5102 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5103 bombout((ssh
,"Unexpected response to X11 forwarding request:"
5104 " packet type %d", ssh
->pktin
.type
));
5107 logevent("X11 forwarding refused");
5109 logevent("X11 forwarding enabled");
5110 ssh
->X11_fwd_enabled
= TRUE
;
5115 * Enable port forwardings.
5120 int sport
,dport
,sserv
,dserv
;
5121 char sports
[256], dports
[256], host
[256];
5125 ssh
->rportfwds
= newtree234(ssh_rportcmp_ssh2
);
5126 /* Add port forwardings. */
5127 ssh
->portfwd_strptr
= cfg
.portfwd
;
5128 while (*ssh
->portfwd_strptr
) {
5129 type
= *ssh
->portfwd_strptr
++;
5131 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= '\t')
5132 sports
[n
++] = *ssh
->portfwd_strptr
++;
5134 if (*ssh
->portfwd_strptr
== '\t')
5135 ssh
->portfwd_strptr
++;
5137 while (*ssh
->portfwd_strptr
&& *ssh
->portfwd_strptr
!= ':')
5138 host
[n
++] = *ssh
->portfwd_strptr
++;
5140 if (*ssh
->portfwd_strptr
== ':')
5141 ssh
->portfwd_strptr
++;
5143 while (*ssh
->portfwd_strptr
)
5144 dports
[n
++] = *ssh
->portfwd_strptr
++;
5146 ssh
->portfwd_strptr
++;
5147 dport
= atoi(dports
);
5151 se
= getservbyname(dports
, NULL
);
5153 dport
= ntohs(se
->s_port
);
5156 "Service lookup failed for destination port \"%s\"",
5161 sport
= atoi(sports
);
5165 se
= getservbyname(sports
, NULL
);
5167 sport
= ntohs(se
->s_port
);
5170 "Service lookup failed for source port \"%s\"",
5175 if (sport
&& dport
) {
5177 pfd_addforward(host
, dport
, sport
, ssh
);
5178 sprintf(buf
, "Local port %.*s%.*s%d%.*s forwarding to"
5179 " %s:%.*s%.*s%d%.*s",
5180 sserv ?
strlen(sports
) : 0, sports
,
5181 sserv
, "(", sport
, sserv
, ")",
5183 dserv ?
strlen(dports
) : 0, dports
,
5184 dserv
, "(", dport
, dserv
, ")");
5187 struct ssh_rportfwd
*pf
;
5188 pf
= smalloc(sizeof(*pf
));
5189 strcpy(pf
->dhost
, host
);
5192 if (add234(ssh
->rportfwds
, pf
) != pf
) {
5194 "Duplicate remote port forwarding to %s:%d",
5199 sprintf(buf
, "Requesting remote port %.*s%.*s%d%.*s"
5200 " forward to %s:%.*s%.*s%d%.*s",
5201 sserv ?
strlen(sports
) : 0, sports
,
5202 sserv
, "(", sport
, sserv
, ")",
5204 dserv ?
strlen(dports
) : 0, dports
,
5205 dserv
, "(", dport
, dserv
, ")");
5207 ssh2_pkt_init(ssh
, SSH2_MSG_GLOBAL_REQUEST
);
5208 ssh2_pkt_addstring(ssh
, "tcpip-forward");
5209 ssh2_pkt_addbool(ssh
, 1);/* want reply */
5210 if (cfg
.rport_acceptall
)
5211 ssh2_pkt_addstring(ssh
, "0.0.0.0");
5213 ssh2_pkt_addstring(ssh
, "127.0.0.1");
5214 ssh2_pkt_adduint32(ssh
, sport
);
5218 crWaitUntilV(ispkt
);
5219 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5220 unsigned i
= ssh2_pkt_getuint32(ssh
);
5221 struct ssh_channel
*c
;
5222 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5224 continue;/* nonexistent channel */
5225 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5227 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5229 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
5230 if (ssh
->pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
5231 bombout((ssh
,"Unexpected response to port "
5232 "forwarding request: packet type %d",
5236 logevent("Server refused this port forwarding");
5238 logevent("Remote port forwarding enabled");
5247 * Potentially enable agent forwarding.
5249 if (cfg
.agentfwd
&& agent_exists()) {
5250 logevent("Requesting OpenSSH-style agent forwarding");
5251 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5252 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
5253 ssh2_pkt_addstring(ssh
, "auth-agent-req@openssh.com");
5254 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5258 crWaitUntilV(ispkt
);
5259 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5260 unsigned i
= ssh2_pkt_getuint32(ssh
);
5261 struct ssh_channel
*c
;
5262 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5264 continue; /* nonexistent channel */
5265 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5267 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5269 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5270 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5271 bombout((ssh
,"Unexpected response to agent forwarding request:"
5272 " packet type %d", ssh
->pktin
.type
));
5275 logevent("Agent forwarding refused");
5277 logevent("Agent forwarding enabled");
5278 ssh
->agentfwd_enabled
= TRUE
;
5283 * Now allocate a pty for the session.
5286 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5287 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5288 ssh2_pkt_addstring(ssh
, "pty-req");
5289 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5290 ssh2_pkt_addstring(ssh
, cfg
.termtype
);
5291 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
5292 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
5293 ssh2_pkt_adduint32(ssh
, 0); /* pixel width */
5294 ssh2_pkt_adduint32(ssh
, 0); /* pixel height */
5295 ssh2_pkt_addstring_start(ssh
);
5296 ssh2_pkt_addstring_data(ssh
, "\0", 1); /* TTY_OP_END, no special options */
5298 ssh
->state
= SSH_STATE_INTERMED
;
5301 crWaitUntilV(ispkt
);
5302 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5303 unsigned i
= ssh2_pkt_getuint32(ssh
);
5304 struct ssh_channel
*c
;
5305 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5307 continue; /* nonexistent channel */
5308 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5310 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5312 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5313 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5314 bombout((ssh
,"Unexpected response to pty request:"
5315 " packet type %d", ssh
->pktin
.type
));
5318 c_write_str(ssh
, "Server refused to allocate pty\r\n");
5319 ssh
->editing
= ssh
->echoing
= 1;
5321 logevent("Allocated pty");
5324 ssh
->editing
= ssh
->echoing
= 1;
5328 * Start a shell or a remote command. We may have to attempt
5329 * this twice if the config data has provided a second choice
5336 if (ssh
->fallback_cmd
) {
5337 subsys
= cfg
.ssh_subsys2
;
5338 cmd
= cfg
.remote_cmd_ptr2
;
5340 subsys
= cfg
.ssh_subsys
;
5341 cmd
= cfg
.remote_cmd_ptr
;
5344 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
5345 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
); /* recipient channel */
5347 ssh2_pkt_addstring(ssh
, "subsystem");
5348 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5349 ssh2_pkt_addstring(ssh
, cmd
);
5351 ssh2_pkt_addstring(ssh
, "exec");
5352 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5353 ssh2_pkt_addstring(ssh
, cmd
);
5355 ssh2_pkt_addstring(ssh
, "shell");
5356 ssh2_pkt_addbool(ssh
, 1); /* want reply */
5360 crWaitUntilV(ispkt
);
5361 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5362 unsigned i
= ssh2_pkt_getuint32(ssh
);
5363 struct ssh_channel
*c
;
5364 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5366 continue; /* nonexistent channel */
5367 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5369 } while (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
5370 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
5371 if (ssh
->pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
5372 bombout((ssh
,"Unexpected response to shell/command request:"
5373 " packet type %d", ssh
->pktin
.type
));
5377 * We failed to start the command. If this is the
5378 * fallback command, we really are finished; if it's
5379 * not, and if the fallback command exists, try falling
5380 * back to it before complaining.
5382 if (!ssh
->fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
5383 logevent("Primary command failed; attempting fallback");
5384 ssh
->fallback_cmd
= TRUE
;
5387 bombout((ssh
,"Server refused to start a shell/command"));
5390 logevent("Started a shell/command");
5395 ssh
->state
= SSH_STATE_SESSION
;
5396 if (ssh
->size_needed
)
5397 ssh_size(ssh
, ssh
->term_width
, ssh
->term_height
);
5398 if (ssh
->eof_needed
)
5399 ssh_special(ssh
, TS_EOF
);
5405 ldisc_send(ssh
->ldisc
, NULL
, 0, 0);/* cause ldisc to notice changes */
5409 s
->try_send
= FALSE
;
5411 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
5412 ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
5415 unsigned i
= ssh2_pkt_getuint32(ssh
);
5416 struct ssh_channel
*c
;
5417 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5419 continue; /* nonexistent channel */
5420 if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
5421 ssh2_pkt_getuint32(ssh
) != SSH2_EXTENDED_DATA_STDERR
)
5422 continue; /* extended but not stderr */
5423 ssh2_pkt_getstring(ssh
, &data
, &length
);
5426 c
->v
.v2
.locwindow
-= length
;
5428 case CHAN_MAINSESSION
:
5430 from_backend(ssh
->frontend
, ssh
->pktin
.type
==
5431 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
5435 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
5438 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
5441 while (length
> 0) {
5442 if (c
->u
.a
.lensofar
< 4) {
5443 int l
= min(4 - c
->u
.a
.lensofar
, length
);
5444 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
5448 c
->u
.a
.lensofar
+= l
;
5450 if (c
->u
.a
.lensofar
== 4) {
5452 4 + GET_32BIT(c
->u
.a
.msglen
);
5453 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
5454 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
5456 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
5458 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
5460 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
5464 c
->u
.a
.lensofar
+= l
;
5466 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
5467 void *reply
, *sentreply
;
5469 agent_query(c
->u
.a
.message
,
5470 c
->u
.a
.totallen
, &reply
,
5475 /* Fake SSH_AGENT_FAILURE. */
5476 sentreply
= "\0\0\0\1\5";
5479 ssh2_add_channel_data(c
, sentreply
, replylen
);
5483 sfree(c
->u
.a
.message
);
5484 c
->u
.a
.lensofar
= 0;
5491 * If we are not buffering too much data,
5492 * enlarge the window again at the remote side.
5494 if (bufsize
< OUR_V2_WINSIZE
)
5495 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
5497 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
5498 unsigned i
= ssh2_pkt_getuint32(ssh
);
5499 struct ssh_channel
*c
;
5501 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5503 continue; /* nonexistent channel */
5505 if (c
->type
== CHAN_X11
) {
5507 * Remote EOF on an X11 channel means we should
5508 * wrap up and close the channel ourselves.
5510 x11_close(c
->u
.x11
.s
);
5512 } else if (c
->type
== CHAN_AGENT
) {
5514 } else if (c
->type
== CHAN_SOCKDATA
) {
5515 pfd_close(c
->u
.pfd
.s
);
5518 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
5519 unsigned i
= ssh2_pkt_getuint32(ssh
);
5520 struct ssh_channel
*c
;
5522 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5523 if (!c
|| ((int)c
->remoteid
) == -1) {
5524 bombout((ssh
,"Received CHANNEL_CLOSE for %s channel %d\n",
5525 c ?
"half-open" : "nonexistent", i
));
5527 /* Do pre-close processing on the channel. */
5529 case CHAN_MAINSESSION
:
5530 break; /* nothing to see here, move along */
5532 if (c
->u
.x11
.s
!= NULL
)
5533 x11_close(c
->u
.x11
.s
);
5540 if (c
->u
.pfd
.s
!= NULL
)
5541 pfd_close(c
->u
.pfd
.s
);
5545 if (c
->closes
== 0) {
5546 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5547 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5550 del234(ssh
->channels
, c
);
5551 bufchain_clear(&c
->v
.v2
.outbuffer
);
5555 * See if that was the last channel left open.
5557 if (count234(ssh
->channels
) == 0) {
5560 * We used to send SSH_MSG_DISCONNECT here,
5561 * because I'd believed that _every_ conforming
5562 * SSH2 connection had to end with a disconnect
5563 * being sent by at least one side; apparently
5564 * I was wrong and it's perfectly OK to
5565 * unceremoniously slam the connection shut
5566 * when you're done, and indeed OpenSSH feels
5567 * this is more polite than sending a
5568 * DISCONNECT. So now we don't.
5570 logevent("All channels closed. Disconnecting");
5571 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5572 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5573 ssh2_pkt_addstring(ssh
, "All open channels closed");
5574 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5577 ssh
->state
= SSH_STATE_CLOSED
;
5580 continue; /* remote sends close; ignore (FIXME) */
5581 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
5582 unsigned i
= ssh2_pkt_getuint32(ssh
);
5583 struct ssh_channel
*c
;
5584 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5586 continue; /* nonexistent channel */
5587 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32(ssh
);
5589 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
5590 unsigned i
= ssh2_pkt_getuint32(ssh
);
5591 struct ssh_channel
*c
;
5592 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5594 continue; /* nonexistent channel */
5595 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5596 continue; /* dunno why they're confirming this */
5597 c
->remoteid
= ssh2_pkt_getuint32(ssh
);
5598 c
->type
= CHAN_SOCKDATA
;
5599 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32(ssh
);
5600 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32(ssh
);
5602 pfd_confirm(c
->u
.pfd
.s
);
5605 * We have a pending close on this channel,
5606 * which we decided on before the server acked
5607 * the channel open. So now we know the
5608 * remoteid, we can close it again.
5610 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_CLOSE
);
5611 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5614 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
5615 unsigned i
= ssh2_pkt_getuint32(ssh
);
5616 struct ssh_channel
*c
;
5617 c
= find234(ssh
->channels
, &i
, ssh_channelfind
);
5619 continue; /* nonexistent channel */
5620 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
5621 continue; /* dunno why they're failing this */
5623 logevent("Forwarded connection refused by server");
5625 pfd_close(c
->u
.pfd
.s
);
5627 del234(ssh
->channels
, c
);
5629 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
5632 int typelen
, want_reply
;
5633 struct ssh_channel
*c
;
5635 localid
= ssh2_pkt_getuint32(ssh
);
5636 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5637 want_reply
= ssh2_pkt_getbool(ssh
);
5640 * First, check that the channel exists. Otherwise,
5641 * we can instantly disconnect with a rude message.
5643 c
= find234(ssh
->channels
, &localid
, ssh_channelfind
);
5646 sprintf(buf
, "Received channel request for nonexistent"
5647 " channel %d", localid
);
5649 ssh2_pkt_init(ssh
, SSH2_MSG_DISCONNECT
);
5650 ssh2_pkt_adduint32(ssh
, SSH2_DISCONNECT_BY_APPLICATION
);
5651 ssh2_pkt_addstring(ssh
, buf
);
5652 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5654 connection_fatal("%s", buf
);
5655 ssh
->state
= SSH_STATE_CLOSED
;
5660 * Having got the channel number, we now look at
5661 * the request type string to see if it's something
5664 if (typelen
== 11 && !memcmp(type
, "exit-status", 11) &&
5665 c
== ssh
->mainchan
) {
5666 /* We recognise "exit-status" on the primary channel. */
5668 ssh
->exitcode
= ssh2_pkt_getuint32(ssh
);
5669 sprintf(buf
, "Server sent command exit status %d",
5673 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_SUCCESS
);
5674 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5679 * This is a channel request we don't know
5680 * about, so we now either ignore the request
5681 * or respond with CHANNEL_FAILURE, depending
5685 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_FAILURE
);
5686 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5690 } else if (ssh
->pktin
.type
== SSH2_MSG_GLOBAL_REQUEST
) {
5692 int typelen
, want_reply
;
5694 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5695 want_reply
= ssh2_pkt_getbool(ssh
);
5698 * We currently don't support any global requests
5699 * at all, so we either ignore the request or
5700 * respond with REQUEST_FAILURE, depending on
5704 ssh2_pkt_init(ssh
, SSH2_MSG_REQUEST_FAILURE
);
5707 } else if (ssh
->pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
5711 struct ssh_channel
*c
;
5712 unsigned remid
, winsize
, pktsize
;
5713 ssh2_pkt_getstring(ssh
, &type
, &typelen
);
5714 c
= smalloc(sizeof(struct ssh_channel
));
5717 remid
= ssh2_pkt_getuint32(ssh
);
5718 winsize
= ssh2_pkt_getuint32(ssh
);
5719 pktsize
= ssh2_pkt_getuint32(ssh
);
5721 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5722 if (!ssh
->X11_fwd_enabled
)
5723 error
= "X11 forwarding is not enabled";
5724 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
,
5725 ssh
->x11auth
) != NULL
) {
5726 error
= "Unable to open an X11 connection";
5730 } else if (typelen
== 15 &&
5731 !memcmp(type
, "forwarded-tcpip", 15)) {
5732 struct ssh_rportfwd pf
, *realpf
;
5735 ssh2_pkt_getstring(ssh
, &dummy
, &dummylen
);/* skip address */
5736 pf
.sport
= ssh2_pkt_getuint32(ssh
);
5737 realpf
= find234(ssh
->rportfwds
, &pf
, NULL
);
5738 if (realpf
== NULL
) {
5739 error
= "Remote port is not recognised";
5741 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5744 sprintf(buf
, "Received remote port open request for %s:%d",
5745 realpf
->dhost
, realpf
->dport
);
5748 sprintf(buf
, "Port open failed: %s", e
);
5750 error
= "Port open failed";
5752 logevent("Forwarded port opened successfully");
5753 c
->type
= CHAN_SOCKDATA
;
5756 } else if (typelen
== 22 &&
5757 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5758 if (!ssh
->agentfwd_enabled
)
5759 error
= "Agent forwarding is not enabled";
5761 c
->type
= CHAN_AGENT
; /* identify channel type */
5762 c
->u
.a
.lensofar
= 0;
5765 error
= "Unsupported channel type requested";
5768 c
->remoteid
= remid
;
5770 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5771 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5772 ssh2_pkt_adduint32(ssh
, SSH2_OPEN_CONNECT_FAILED
);
5773 ssh2_pkt_addstring(ssh
, error
);
5774 ssh2_pkt_addstring(ssh
, "en"); /* language tag */
5778 c
->localid
= alloc_channel_id(ssh
);
5780 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5781 c
->v
.v2
.remwindow
= winsize
;
5782 c
->v
.v2
.remmaxpkt
= pktsize
;
5783 bufchain_init(&c
->v
.v2
.outbuffer
);
5784 add234(ssh
->channels
, c
);
5785 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5786 ssh2_pkt_adduint32(ssh
, c
->remoteid
);
5787 ssh2_pkt_adduint32(ssh
, c
->localid
);
5788 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);
5789 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
5793 bombout((ssh
,"Strange packet received: type %d", ssh
->pktin
.type
));
5798 * We have spare data. Add it to the channel buffer.
5800 ssh2_add_channel_data(ssh
->mainchan
, in
, inlen
);
5805 struct ssh_channel
*c
;
5807 * Try to send data on all channels if we can.
5809 for (i
= 0; NULL
!= (c
= index234(ssh
->channels
, i
)); i
++) {
5810 int bufsize
= ssh2_try_send(c
);
5813 case CHAN_MAINSESSION
:
5814 /* stdin need not receive an unthrottle
5815 * notification since it will be polled */
5818 x11_unthrottle(c
->u
.x11
.s
);
5821 /* agent sockets are request/response and need no
5822 * buffer management */
5825 pfd_unthrottle(c
->u
.pfd
.s
);
5837 * Handle the top-level SSH2 protocol.
5839 static void ssh2_protocol(Ssh ssh
, unsigned char *in
, int inlen
, int ispkt
)
5841 if (do_ssh2_transport(ssh
, in
, inlen
, ispkt
) == 0)
5843 do_ssh2_authconn(ssh
, in
, inlen
, ispkt
);
5847 * Called to set up the connection.
5849 * Returns an error message, or NULL on success.
5851 static char *ssh_init(void *frontend_handle
, void **backend_handle
,
5852 char *host
, int port
, char **realhost
, int nodelay
)
5857 ssh
= smalloc(sizeof(*ssh
));
5860 ssh
->v1_cipher_ctx
= NULL
;
5861 ssh
->crcda_ctx
= NULL
;
5862 ssh
->cscipher
= NULL
;
5863 ssh
->cs_cipher_ctx
= NULL
;
5864 ssh
->sccipher
= NULL
;
5865 ssh
->sc_cipher_ctx
= NULL
;
5867 ssh
->cs_mac_ctx
= NULL
;
5869 ssh
->sc_mac_ctx
= NULL
;
5871 ssh
->cs_comp_ctx
= NULL
;
5873 ssh
->sc_comp_ctx
= NULL
;
5875 ssh
->hostkey
= NULL
;
5877 ssh
->state
= SSH_STATE_PREPACKET
;
5878 ssh
->size_needed
= FALSE
;
5879 ssh
->eof_needed
= FALSE
;
5883 static const struct Packet empty
= { 0, 0, NULL
, NULL
, 0 };
5884 ssh
->pktin
= ssh
->pktout
= empty
;
5886 ssh
->deferred_send_data
= NULL
;
5887 ssh
->deferred_len
= 0;
5888 ssh
->deferred_size
= 0;
5889 ssh
->fallback_cmd
= 0;
5891 ssh
->x11auth
= NULL
;
5892 ssh
->v1_compressing
= FALSE
;
5893 ssh
->v2_outgoing_sequence
= 0;
5894 ssh
->ssh1_rdpkt_crstate
= 0;
5895 ssh
->ssh2_rdpkt_crstate
= 0;
5896 ssh
->do_ssh_init_crstate
= 0;
5897 ssh
->ssh_gotdata_crstate
= 0;
5898 ssh
->ssh1_protocol_crstate
= 0;
5899 ssh
->do_ssh1_login_crstate
= 0;
5900 ssh
->do_ssh2_transport_crstate
= 0;
5901 ssh
->do_ssh2_authconn_crstate
= 0;
5902 ssh
->do_ssh_init_state
= NULL
;
5903 ssh
->do_ssh1_login_state
= NULL
;
5904 ssh
->do_ssh2_transport_state
= NULL
;
5905 ssh
->do_ssh2_authconn_state
= NULL
;
5906 ssh
->mainchan
= NULL
;
5908 *backend_handle
= ssh
;
5911 if (crypto_startup() == 0)
5912 return "Microsoft high encryption pack not installed!";
5915 ssh
->frontend
= frontend_handle
;
5916 ssh
->term_width
= cfg
.width
;
5917 ssh
->term_height
= cfg
.height
;
5922 ssh
->v1_throttle_count
= 0;
5923 ssh
->overall_bufsize
= 0;
5924 ssh
->fallback_cmd
= 0;
5926 p
= connect_to_host(ssh
, host
, port
, realhost
, nodelay
);
5934 * Called to send data down the Telnet connection.
5936 static int ssh_send(void *handle
, char *buf
, int len
)
5938 Ssh ssh
= (Ssh
) handle
;
5940 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5943 ssh
->protocol(ssh
, buf
, len
, 0);
5945 return ssh_sendbuffer(ssh
);
5949 * Called to query the current amount of buffered stdin data.
5951 static int ssh_sendbuffer(void *handle
)
5953 Ssh ssh
= (Ssh
) handle
;
5956 if (ssh
== NULL
|| ssh
->s
== NULL
|| ssh
->protocol
== NULL
)
5960 * If the SSH socket itself has backed up, add the total backup
5961 * size on that to any individual buffer on the stdin channel.
5964 if (ssh
->throttled_all
)
5965 override_value
= ssh
->overall_bufsize
;
5967 if (ssh
->version
== 1) {
5968 return override_value
;
5969 } else if (ssh
->version
== 2) {
5970 if (!ssh
->mainchan
|| ssh
->mainchan
->closes
> 0)
5971 return override_value
;
5973 return (override_value
+
5974 bufchain_size(&ssh
->mainchan
->v
.v2
.outbuffer
));
5981 * Called to set the size of the window from SSH's POV.
5983 static void ssh_size(void *handle
, int width
, int height
)
5985 Ssh ssh
= (Ssh
) handle
;
5987 ssh
->term_width
= width
;
5988 ssh
->term_height
= height
;
5990 switch (ssh
->state
) {
5991 case SSH_STATE_BEFORE_SIZE
:
5992 case SSH_STATE_PREPACKET
:
5993 case SSH_STATE_CLOSED
:
5994 break; /* do nothing */
5995 case SSH_STATE_INTERMED
:
5996 ssh
->size_needed
= TRUE
; /* buffer for later */
5998 case SSH_STATE_SESSION
:
6000 if (ssh
->version
== 1) {
6001 send_packet(ssh
, SSH1_CMSG_WINDOW_SIZE
,
6002 PKT_INT
, ssh
->term_height
,
6003 PKT_INT
, ssh
->term_width
,
6004 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
6006 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_REQUEST
);
6007 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6008 ssh2_pkt_addstring(ssh
, "window-change");
6009 ssh2_pkt_addbool(ssh
, 0);
6010 ssh2_pkt_adduint32(ssh
, ssh
->term_width
);
6011 ssh2_pkt_adduint32(ssh
, ssh
->term_height
);
6012 ssh2_pkt_adduint32(ssh
, 0);
6013 ssh2_pkt_adduint32(ssh
, 0);
6022 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6023 * can send an EOF and collect resulting output (e.g. `plink
6026 static void ssh_special(void *handle
, Telnet_Special code
)
6028 Ssh ssh
= (Ssh
) handle
;
6030 if (code
== TS_EOF
) {
6031 if (ssh
->state
!= SSH_STATE_SESSION
) {
6033 * Buffer the EOF in case we are pre-SESSION, so we can
6034 * send it as soon as we reach SESSION.
6037 ssh
->eof_needed
= TRUE
;
6040 if (ssh
->version
== 1) {
6041 send_packet(ssh
, SSH1_CMSG_EOF
, PKT_END
);
6043 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_EOF
);
6044 ssh2_pkt_adduint32(ssh
, ssh
->mainchan
->remoteid
);
6047 logevent("Sent EOF message");
6048 } else if (code
== TS_PING
) {
6049 if (ssh
->state
== SSH_STATE_CLOSED
6050 || ssh
->state
== SSH_STATE_PREPACKET
) return;
6051 if (ssh
->version
== 1) {
6052 if (!(ssh
->remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
))
6053 send_packet(ssh
, SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
6055 ssh2_pkt_init(ssh
, SSH2_MSG_IGNORE
);
6056 ssh2_pkt_addstring_start(ssh
);
6064 void *new_sock_channel(void *handle
, Socket s
)
6066 Ssh ssh
= (Ssh
) handle
;
6067 struct ssh_channel
*c
;
6068 c
= smalloc(sizeof(struct ssh_channel
));
6072 c
->remoteid
= -1; /* to be set when open confirmed */
6073 c
->localid
= alloc_channel_id(ssh
);
6075 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
6077 bufchain_init(&c
->v
.v2
.outbuffer
);
6078 add234(ssh
->channels
, c
);
6084 * This is called when stdout/stderr (the entity to which
6085 * from_backend sends data) manages to clear some backlog.
6087 void ssh_unthrottle(void *handle
, int bufsize
)
6089 Ssh ssh
= (Ssh
) handle
;
6090 if (ssh
->version
== 1) {
6091 if (ssh
->v1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
6092 ssh
->v1_stdout_throttling
= 0;
6093 ssh1_throttle(ssh
, -1);
6096 if (ssh
->mainchan
&& ssh
->mainchan
->closes
== 0)
6097 ssh2_set_window(ssh
->mainchan
, OUR_V2_WINSIZE
- bufsize
);
6101 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
6103 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
6107 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
6110 if (ssh
->version
== 1) {
6111 send_packet(ssh
, SSH1_MSG_PORT_OPEN
,
6112 PKT_INT
, c
->localid
,
6115 //PKT_STR, <org:orgport>,
6118 ssh2_pkt_init(ssh
, SSH2_MSG_CHANNEL_OPEN
);
6119 ssh2_pkt_addstring(ssh
, "direct-tcpip");
6120 ssh2_pkt_adduint32(ssh
, c
->localid
);
6121 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
6122 ssh2_pkt_adduint32(ssh
, c
->v
.v2
.locwindow
);/* our window size */
6123 ssh2_pkt_adduint32(ssh
, 0x4000UL
); /* our max pkt size */
6124 ssh2_pkt_addstring(ssh
, hostname
);
6125 ssh2_pkt_adduint32(ssh
, port
);
6127 * We make up values for the originator data; partly it's
6128 * too much hassle to keep track, and partly I'm not
6129 * convinced the server should be told details like that
6130 * about my local network configuration.
6132 ssh2_pkt_addstring(ssh
, "client-side-connection");
6133 ssh2_pkt_adduint32(ssh
, 0);
6139 static Socket
ssh_socket(void *handle
)
6141 Ssh ssh
= (Ssh
) handle
;
6145 static int ssh_sendok(void *handle
)
6147 Ssh ssh
= (Ssh
) handle
;
6148 return ssh
->send_ok
;
6151 static int ssh_ldisc(void *handle
, int option
)
6153 Ssh ssh
= (Ssh
) handle
;
6154 if (option
== LD_ECHO
)
6155 return ssh
->echoing
;
6156 if (option
== LD_EDIT
)
6157 return ssh
->editing
;
6161 static void ssh_provide_ldisc(void *handle
, void *ldisc
)
6163 Ssh ssh
= (Ssh
) handle
;
6167 static void ssh_provide_logctx(void *handle
, void *logctx
)
6169 Ssh ssh
= (Ssh
) handle
;
6170 ssh
->logctx
= logctx
;
6173 static int ssh_return_exitcode(void *handle
)
6175 Ssh ssh
= (Ssh
) handle
;
6176 return ssh
->exitcode
;
6180 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6181 * that fails. This variable is the means by which scp.c can reach
6182 * into the SSH code and find out which one it got.
6184 extern int ssh_fallback_cmd(void *handle
)
6186 Ssh ssh
= (Ssh
) handle
;
6187 return ssh
->fallback_cmd
;
6190 Backend ssh_backend
= {
6197 ssh_return_exitcode
,