18 /* uncomment this for packet level debugging */
19 /* #define DUMP_PACKETS */
21 #define logevent(s) { logevent(s); \
22 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
23 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
25 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
26 (s ? sk_close(s), s = NULL : 0), \
27 connection_fatal msg )
29 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
30 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
31 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
32 #define SSH1_CMSG_USER 4 /* 0x4 */
33 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
34 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
35 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
36 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
37 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
38 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
39 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
40 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
41 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
42 #define SSH1_SMSG_FAILURE 15 /* 0xf */
43 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
44 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
45 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
46 #define SSH1_CMSG_EOF 19 /* 0x13 */
47 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
48 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
49 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
50 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
51 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
52 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
53 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
54 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
55 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
56 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
57 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
58 #define SSH1_MSG_IGNORE 32 /* 0x20 */
59 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
60 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
61 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
62 #define SSH1_MSG_DEBUG 36 /* 0x24 */
63 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
64 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
65 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
66 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
67 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
68 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
69 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
71 #define SSH1_AUTH_TIS 5 /* 0x5 */
72 #define SSH1_AUTH_CCARD 16 /* 0x10 */
74 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
75 /* Mask for protoflags we will echo back to server if seen */
76 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
78 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
79 #define SSH2_MSG_IGNORE 2 /* 0x2 */
80 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
81 #define SSH2_MSG_DEBUG 4 /* 0x4 */
82 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
83 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
84 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
85 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
86 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
87 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
88 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
89 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
90 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
91 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
92 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
93 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
94 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
95 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
96 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
97 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
98 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
99 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
100 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
101 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
102 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
103 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
104 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
105 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
106 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
107 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
108 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
109 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
110 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
111 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
112 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
113 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
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
165 #define GET_32BIT(cp) \
166 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
167 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
168 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
169 ((unsigned long)(unsigned char)(cp)[3]))
171 #define PUT_32BIT(cp, value) { \
172 (cp)[0] = (unsigned char)((value) >> 24); \
173 (cp)[1] = (unsigned char)((value) >> 16); \
174 (cp)[2] = (unsigned char)((value) >> 8); \
175 (cp)[3] = (unsigned char)(value); }
177 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
179 /* Coroutine mechanics for the sillier bits of the code */
180 #define crBegin1 static int crLine = 0;
181 #define crBegin2 switch(crLine) { case 0:;
182 #define crBegin crBegin1; crBegin2;
183 #define crFinish(z) } crLine = 0; return (z)
184 #define crFinishV } crLine = 0; return
185 #define crReturn(z) \
187 crLine=__LINE__; return (z); case __LINE__:;\
191 crLine=__LINE__; return; case __LINE__:;\
193 #define crStop(z) do{ crLine = 0; return (z); }while(0)
194 #define crStopV do{ crLine = 0; return; }while(0)
195 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
196 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
198 extern char *x11_init(Socket
*, char *, void *);
199 extern void x11_close(Socket
);
200 extern int x11_send(Socket
, char *, int);
201 extern void x11_invent_auth(char *, int, char *, int);
202 extern void x11_unthrottle(Socket s
);
203 extern void x11_override_throttle(Socket s
, int enable
);
205 extern char *pfd_newconnect(Socket
* s
, char *hostname
, int port
, void *c
);
206 extern char *pfd_addforward(char *desthost
, int destport
, int port
);
207 extern void pfd_close(Socket s
);
208 extern int pfd_send(Socket s
, char *data
, int len
);
209 extern void pfd_confirm(Socket s
);
210 extern void pfd_unthrottle(Socket s
);
211 extern void pfd_override_throttle(Socket s
, int enable
);
214 * Buffer management constants. There are several of these for
215 * various different purposes:
217 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
218 * on a local data stream before we throttle the whole SSH
219 * connection (in SSH1 only). Throttling the whole connection is
220 * pretty drastic so we set this high in the hope it won't
223 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
224 * on the SSH connection itself before we defensively throttle
225 * _all_ local data streams. This is pretty drastic too (though
226 * thankfully unlikely in SSH2 since the window mechanism should
227 * ensure that the server never has any need to throttle its end
228 * of the connection), so we set this high as well.
230 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
234 #define SSH1_BUFFER_LIMIT 32768
235 #define SSH_MAX_BACKLOG 32768
236 #define OUR_V2_WINSIZE 16384
238 const static struct ssh_kex
*kex_algs
[] = {
239 &ssh_diffiehellman_gex
,
243 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
245 static void nullmac_key(unsigned char *key
)
248 static void nullmac_generate(unsigned char *blk
, int len
,
252 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
)
256 const static struct ssh_mac ssh_mac_none
= {
257 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
259 const static struct ssh_mac
*macs
[] = {
260 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
262 const static struct ssh_mac
*buggymacs
[] = {
263 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
266 static void ssh_comp_none_init(void)
269 static int ssh_comp_none_block(unsigned char *block
, int len
,
270 unsigned char **outblock
, int *outlen
)
274 static int ssh_comp_none_disable(void)
278 const static struct ssh_compress ssh_comp_none
= {
280 ssh_comp_none_init
, ssh_comp_none_block
,
281 ssh_comp_none_init
, ssh_comp_none_block
,
282 ssh_comp_none_disable
284 extern const struct ssh_compress ssh_zlib
;
285 const static struct ssh_compress
*compressions
[] = {
286 &ssh_zlib
, &ssh_comp_none
289 enum { /* channel types */
294 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
298 * 2-3-4 tree storing channels.
301 unsigned remoteid
, localid
;
305 struct ssh1_data_channel
{
308 struct ssh2_data_channel
{
310 unsigned remwindow
, remmaxpkt
;
315 struct ssh_agent_channel
{
316 unsigned char *message
;
317 unsigned char msglen
[4];
318 int lensofar
, totallen
;
320 struct ssh_x11_channel
{
323 struct ssh_pfd_channel
{
330 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
331 * 2 use this structure in different ways, reflecting SSH 2's
332 * altogether saner approach to port forwarding.
334 * In SSH 1, you arrange a remote forwarding by sending the server
335 * the remote port number, and the local destination host:port.
336 * When a connection comes in, the server sends you back that
337 * host:port pair, and you connect to it. This is a ready-made
338 * security hole if you're not on the ball: a malicious server
339 * could send you back _any_ host:port pair, so if you trustingly
340 * connect to the address it gives you then you've just opened the
341 * entire inside of your corporate network just by connecting
342 * through it to a dodgy SSH server. Hence, we must store a list of
343 * host:port pairs we _are_ trying to forward to, and reject a
344 * connection request from the server if it's not in the list.
346 * In SSH 2, each side of the connection minds its own business and
347 * doesn't send unnecessary information to the other. You arrange a
348 * remote forwarding by sending the server just the remote port
349 * number. When a connection comes in, the server tells you which
350 * of its ports was connected to; and _you_ have to remember what
351 * local host:port pair went with that port number.
353 * Hence: in SSH 1 this structure stores host:port pairs we intend
354 * to allow connections to, and is indexed by those host:port
355 * pairs. In SSH 2 it stores a mapping from source port to
356 * destination host:port pair, and is indexed by source port.
358 struct ssh_rportfwd
{
359 unsigned sport
, dport
;
372 static SHA_State exhash
, exhashbase
;
374 static Socket s
= NULL
;
376 static unsigned char session_key
[32];
377 static int ssh1_compressing
;
378 static int ssh1_remote_protoflags
;
379 static int ssh1_local_protoflags
;
380 static int ssh_agentfwd_enabled
;
381 static int ssh_X11_fwd_enabled
;
382 static int ssh_remote_bugs
;
383 static const struct ssh_cipher
*cipher
= NULL
;
384 static const struct ssh2_cipher
*cscipher
= NULL
;
385 static const struct ssh2_cipher
*sccipher
= NULL
;
386 static const struct ssh_mac
*csmac
= NULL
;
387 static const struct ssh_mac
*scmac
= NULL
;
388 static const struct ssh_compress
*cscomp
= NULL
;
389 static const struct ssh_compress
*sccomp
= NULL
;
390 static const struct ssh_kex
*kex
= NULL
;
391 static const struct ssh_signkey
*hostkey
= NULL
;
392 static unsigned char ssh2_session_id
[20];
393 int (*ssh_get_line
) (const char *prompt
, char *str
, int maxlen
,
396 static char *savedhost
;
397 static int savedport
;
398 static int ssh_send_ok
;
399 static int ssh_echoing
, ssh_editing
;
401 static tree234
*ssh_channels
; /* indexed by local id */
402 static struct ssh_channel
*mainchan
; /* primary session channel */
404 static tree234
*ssh_rportfwds
;
408 SSH_STATE_BEFORE_SIZE
,
412 } ssh_state
= SSH_STATE_PREPACKET
;
414 static int size_needed
= FALSE
, eof_needed
= FALSE
;
416 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
417 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
418 static unsigned char *deferred_send_data
= NULL
;
419 static int deferred_len
= 0, deferred_size
= 0;
422 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
423 * that fails. This variable is the means by which scp.c can reach
424 * into the SSH code and find out which one it got.
426 int ssh_fallback_cmd
= 0;
428 static int ssh_version
;
429 static int ssh1_throttle_count
;
430 static int ssh_overall_bufsize
;
431 static int ssh_throttled_all
;
432 static int ssh1_stdout_throttling
;
433 static void (*ssh_protocol
) (unsigned char *in
, int inlen
, int ispkt
);
434 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
435 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
436 static void ssh_size(void);
437 static void ssh_special(Telnet_Special
);
438 static int ssh2_try_send(struct ssh_channel
*c
);
439 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
441 static void ssh_throttle_all(int enable
, int bufsize
);
442 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
443 static int (*s_rdpkt
) (unsigned char **data
, int *datalen
);
444 static int ssh_sendbuffer(void);
446 static struct rdpkt1_state_tag
{
447 long len
, pad
, biglen
, to_read
;
448 unsigned long realcrc
, gotcrc
;
454 static struct rdpkt2_state_tag
{
455 long len
, pad
, payload
, packetlen
, maclen
;
458 unsigned long incoming_sequence
;
461 static int ssh_channelcmp(void *av
, void *bv
)
463 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
464 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
465 if (a
->localid
< b
->localid
)
467 if (a
->localid
> b
->localid
)
471 static int ssh_channelfind(void *av
, void *bv
)
473 unsigned *a
= (unsigned *) av
;
474 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
482 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
484 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
485 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
487 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
488 return i
< 0 ?
-1 : +1;
489 if (a
->dport
> b
->dport
)
491 if (a
->dport
< b
->dport
)
496 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
498 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
499 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
501 if (a
->sport
> b
->sport
)
503 if (a
->sport
< b
->sport
)
508 static int alloc_channel_id(void)
510 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
511 unsigned low
, high
, mid
;
513 struct ssh_channel
*c
;
516 * First-fit allocation of channel numbers: always pick the
517 * lowest unused one. To do this, binary-search using the
518 * counted B-tree to find the largest channel ID which is in a
519 * contiguous sequence from the beginning. (Precisely
520 * everything in that sequence must have ID equal to its tree
521 * index plus CHANNEL_NUMBER_OFFSET.)
523 tsize
= count234(ssh_channels
);
527 while (high
- low
> 1) {
528 mid
= (high
+ low
) / 2;
529 c
= index234(ssh_channels
, mid
);
530 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
531 low
= mid
; /* this one is fine */
533 high
= mid
; /* this one is past it */
536 * Now low points to either -1, or the tree index of the
537 * largest ID in the initial sequence.
540 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
541 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
543 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
546 static void c_write(char *buf
, int len
)
548 if ((flags
& FLAG_STDERR
)) {
550 for (i
= 0; i
< len
; i
++)
552 fputc(buf
[i
], stderr
);
555 from_backend(1, buf
, len
);
558 static void c_write_untrusted(char *buf
, int len
)
561 for (i
= 0; i
< len
; i
++) {
564 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
569 static void c_write_str(char *buf
)
571 c_write(buf
, strlen(buf
));
575 * Collect incoming data in the incoming packet buffer.
576 * Decipher and verify the packet when it is completely read.
577 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
578 * Update the *data and *datalen variables.
579 * Return the additional nr of bytes needed, or 0 when
580 * a complete packet is available.
582 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
584 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
593 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
594 while ((*datalen
) == 0)
596 st
->len
= (st
->len
<< 8) + **data
;
597 (*data
)++, (*datalen
)--;
600 st
->pad
= 8 - (st
->len
% 8);
601 st
->biglen
= st
->len
+ st
->pad
;
602 pktin
.length
= st
->len
- 5;
604 if (pktin
.maxlen
< st
->biglen
) {
605 pktin
.maxlen
= st
->biglen
;
606 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
607 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
609 fatalbox("Out of memory");
612 st
->to_read
= st
->biglen
;
614 while (st
->to_read
> 0) {
615 st
->chunk
= st
->to_read
;
616 while ((*datalen
) == 0)
617 crReturn(st
->to_read
);
618 if (st
->chunk
> (*datalen
))
619 st
->chunk
= (*datalen
);
620 memcpy(st
->p
, *data
, st
->chunk
);
622 *datalen
-= st
->chunk
;
624 st
->to_read
-= st
->chunk
;
628 cipher
->decrypt(pktin
.data
, st
->biglen
);
630 debug(("Got packet len=%d pad=%d\n", st
->len
, st
->pad
));
631 dmemdump(pktin
.data
, st
->biglen
);
634 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
635 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
636 if (st
->gotcrc
!= st
->realcrc
) {
637 bombout(("Incorrect CRC received on packet"));
641 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
643 if (ssh1_compressing
) {
644 unsigned char *decompblk
;
647 debug(("Packet payload pre-decompression:\n"));
648 dmemdump(pktin
.body
- 1, pktin
.length
+ 1);
650 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
651 &decompblk
, &decomplen
);
653 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
654 pktin
.maxlen
= st
->pad
+ decomplen
;
655 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
656 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
658 fatalbox("Out of memory");
661 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
663 pktin
.length
= decomplen
- 1;
665 debug(("Packet payload post-decompression:\n"));
666 dmemdump(pktin
.body
- 1, pktin
.length
+ 1);
670 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
671 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
672 pktin
.type
== SSH1_MSG_DEBUG
||
673 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
674 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
675 long strlen
= GET_32BIT(pktin
.body
);
676 if (strlen
+ 4 != pktin
.length
) {
677 bombout(("Received data packet with bogus string length"));
682 pktin
.type
= pktin
.body
[-1];
684 if (pktin
.type
== SSH1_MSG_DEBUG
) {
685 /* log debug message */
687 int strlen
= GET_32BIT(pktin
.body
);
688 strcpy(buf
, "Remote: ");
691 memcpy(buf
+ 8, pktin
.body
+ 4, strlen
);
692 buf
[8 + strlen
] = '\0';
695 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
700 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
701 /* log reason code in disconnect message */
703 unsigned msglen
= GET_32BIT(pktin
.body
);
705 strcpy(buf
, "Remote sent disconnect: ");
706 nowlen
= strlen(buf
);
707 if (msglen
> sizeof(buf
) - nowlen
- 1)
708 msglen
= sizeof(buf
) - nowlen
- 1;
709 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
710 buf
[nowlen
+ msglen
] = '\0';
712 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
719 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
721 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
729 st
->cipherblk
= sccipher
->blksize
;
732 if (st
->cipherblk
< 8)
735 if (pktin
.maxlen
< st
->cipherblk
) {
736 pktin
.maxlen
= st
->cipherblk
;
739 NULL ?
smalloc(st
->cipherblk
+
740 APIEXTRA
) : srealloc(pktin
.data
,
744 fatalbox("Out of memory");
748 * Acquire and decrypt the first block of the packet. This will
749 * contain the length and padding details.
751 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
752 while ((*datalen
) == 0)
753 crReturn(st
->cipherblk
- st
->i
);
754 pktin
.data
[st
->i
] = *(*data
)++;
759 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
762 * Now get the length and padding figures.
764 st
->len
= GET_32BIT(pktin
.data
);
765 st
->pad
= pktin
.data
[4];
768 * This enables us to deduce the payload length.
770 st
->payload
= st
->len
- st
->pad
- 1;
772 pktin
.length
= st
->payload
+ 5;
775 * So now we can work out the total packet length.
777 st
->packetlen
= st
->len
+ 4;
778 st
->maclen
= scmac ? scmac
->len
: 0;
781 * Adjust memory allocation if packet is too big.
783 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
784 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
787 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
792 fatalbox("Out of memory");
796 * Read and decrypt the remainder of the packet.
798 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
800 while ((*datalen
) == 0)
801 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
802 pktin
.data
[st
->i
] = *(*data
)++;
805 /* Decrypt everything _except_ the MAC. */
807 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
808 st
->packetlen
- st
->cipherblk
);
811 debug(("Got packet len=%d pad=%d\n", st
->len
, st
->pad
));
812 dmemdump(pktin
.data
, st
->packetlen
);
819 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
820 st
->incoming_sequence
)) {
821 bombout(("Incorrect MAC received on packet"));
824 st
->incoming_sequence
++; /* whether or not we MACed */
827 * Decompress packet payload.
830 unsigned char *newpayload
;
832 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
833 &newpayload
, &newlen
)) {
834 if (pktin
.maxlen
< newlen
+ 5) {
835 pktin
.maxlen
= newlen
+ 5;
838 NULL ?
smalloc(pktin
.maxlen
+
839 APIEXTRA
) : srealloc(pktin
.data
,
843 fatalbox("Out of memory");
845 pktin
.length
= 5 + newlen
;
846 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
848 debug(("Post-decompression payload:\n"));
849 dmemdump(pktin
.data
+ 5, newlen
);
857 pktin
.type
= pktin
.data
[5];
859 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
860 goto next_packet
; /* FIXME: print DEBUG message */
862 if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
863 /* log reason code in disconnect message */
865 int reason
= GET_32BIT(pktin
.data
+ 6);
866 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
868 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
869 sprintf(buf
, "Received disconnect message (%s)",
870 ssh2_disconnect_reasons
[reason
]);
872 sprintf(buf
, "Received disconnect message (unknown type %d)",
876 strcpy(buf
, "Disconnection message text: ");
877 nowlen
= strlen(buf
);
878 if (msglen
> sizeof(buf
) - nowlen
- 1)
879 msglen
= sizeof(buf
) - nowlen
- 1;
880 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
881 buf
[nowlen
+ msglen
] = '\0';
883 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
885 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
886 ssh2_disconnect_reasons
[reason
] : "unknown",
894 static void ssh1_pktout_size(int len
)
898 len
+= 5; /* type and CRC */
902 pktout
.length
= len
- 5;
903 if (pktout
.maxlen
< biglen
) {
904 pktout
.maxlen
= biglen
;
906 /* Allocate enough buffer space for extra block
907 * for MS CryptEncrypt() */
908 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
909 srealloc(pktout
.data
, biglen
+ 12));
911 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
912 srealloc(pktout
.data
, biglen
+ 4));
915 fatalbox("Out of memory");
917 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
920 static void s_wrpkt_start(int type
, int len
)
922 ssh1_pktout_size(len
);
926 static int s_wrpkt_prepare(void)
928 int pad
, len
, biglen
, i
;
931 pktout
.body
[-1] = pktout
.type
;
933 if (ssh1_compressing
) {
934 unsigned char *compblk
;
937 debug(("Packet payload pre-compression:\n"));
938 dmemdump(pktout
.body
- 1, pktout
.length
+ 1);
940 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
942 ssh1_pktout_size(complen
- 1);
943 memcpy(pktout
.body
- 1, compblk
, complen
);
947 len
= pktout
.length
+ 5; /* type and CRC */
951 for (i
= 0; i
< pad
; i
++)
952 pktout
.data
[i
+ 4] = random_byte();
953 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
954 PUT_32BIT(pktout
.data
+ biglen
, crc
);
955 PUT_32BIT(pktout
.data
, len
);
958 debug(("Sending packet len=%d\n", biglen
+ 4));
959 dmemdump(pktout
.data
, biglen
+ 4);
962 cipher
->encrypt(pktout
.data
+ 4, biglen
);
967 static void s_wrpkt(void)
970 len
= s_wrpkt_prepare();
971 backlog
= sk_write(s
, pktout
.data
, len
);
972 if (backlog
> SSH_MAX_BACKLOG
)
973 ssh_throttle_all(1, backlog
);
976 static void s_wrpkt_defer(void)
979 len
= s_wrpkt_prepare();
980 if (deferred_len
+ len
> deferred_size
) {
981 deferred_size
= deferred_len
+ len
+ 128;
982 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
984 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
989 * Construct a packet with the specified contents.
991 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
993 unsigned char *p
, *argp
, argchar
;
994 unsigned long argint
;
995 int pktlen
, argtype
, arglen
;
999 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1002 (void) va_arg(ap1
, int);
1006 (void) va_arg(ap1
, char);
1010 (void) va_arg(ap1
, unsigned char *);
1011 arglen
= va_arg(ap1
, int);
1015 argp
= va_arg(ap1
, unsigned char *);
1016 arglen
= strlen(argp
);
1017 pktlen
+= 4 + arglen
;
1020 bn
= va_arg(ap1
, Bignum
);
1021 pktlen
+= ssh1_bignum_length(bn
);
1028 s_wrpkt_start(pkttype
, pktlen
);
1031 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1034 argint
= va_arg(ap2
, int);
1035 PUT_32BIT(p
, argint
);
1039 argchar
= va_arg(ap2
, unsigned char);
1044 argp
= va_arg(ap2
, unsigned char *);
1045 arglen
= va_arg(ap2
, int);
1046 memcpy(p
, argp
, arglen
);
1050 argp
= va_arg(ap2
, unsigned char *);
1051 arglen
= strlen(argp
);
1052 PUT_32BIT(p
, arglen
);
1053 memcpy(p
+ 4, argp
, arglen
);
1057 bn
= va_arg(ap2
, Bignum
);
1058 p
+= ssh1_write_bignum(p
, bn
);
1064 static void send_packet(int pkttype
, ...)
1067 va_start(ap1
, pkttype
);
1068 va_start(ap2
, pkttype
);
1069 construct_packet(pkttype
, ap1
, ap2
);
1073 static void defer_packet(int pkttype
, ...)
1076 va_start(ap1
, pkttype
);
1077 va_start(ap2
, pkttype
);
1078 construct_packet(pkttype
, ap1
, ap2
);
1082 static int ssh_versioncmp(char *a
, char *b
)
1085 unsigned long av
, bv
;
1087 av
= strtoul(a
, &ae
, 10);
1088 bv
= strtoul(b
, &be
, 10);
1090 return (av
< bv ?
-1 : +1);
1095 av
= strtoul(ae
, &ae
, 10);
1096 bv
= strtoul(be
, &be
, 10);
1098 return (av
< bv ?
-1 : +1);
1104 * Utility routines for putting an SSH-protocol `string' and
1105 * `uint32' into a SHA state.
1108 static void sha_string(SHA_State
* s
, void *str
, int len
)
1110 unsigned char lenblk
[4];
1111 PUT_32BIT(lenblk
, len
);
1112 SHA_Bytes(s
, lenblk
, 4);
1113 SHA_Bytes(s
, str
, len
);
1116 static void sha_uint32(SHA_State
* s
, unsigned i
)
1118 unsigned char intblk
[4];
1119 PUT_32BIT(intblk
, i
);
1120 SHA_Bytes(s
, intblk
, 4);
1124 * SSH2 packet construction functions.
1126 static void ssh2_pkt_ensure(int length
)
1128 if (pktout
.maxlen
< length
) {
1129 pktout
.maxlen
= length
+ 256;
1132 NULL ?
smalloc(pktout
.maxlen
+
1133 APIEXTRA
) : srealloc(pktout
.data
,
1137 fatalbox("Out of memory");
1140 static void ssh2_pkt_adddata(void *data
, int len
)
1142 pktout
.length
+= len
;
1143 ssh2_pkt_ensure(pktout
.length
);
1144 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1146 static void ssh2_pkt_addbyte(unsigned char byte
)
1148 ssh2_pkt_adddata(&byte
, 1);
1150 static void ssh2_pkt_init(int pkt_type
)
1153 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1155 static void ssh2_pkt_addbool(unsigned char value
)
1157 ssh2_pkt_adddata(&value
, 1);
1159 static void ssh2_pkt_adduint32(unsigned long value
)
1162 PUT_32BIT(x
, value
);
1163 ssh2_pkt_adddata(x
, 4);
1165 static void ssh2_pkt_addstring_start(void)
1167 ssh2_pkt_adduint32(0);
1168 pktout
.savedpos
= pktout
.length
;
1170 static void ssh2_pkt_addstring_str(char *data
)
1172 ssh2_pkt_adddata(data
, strlen(data
));
1173 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1174 pktout
.length
- pktout
.savedpos
);
1176 static void ssh2_pkt_addstring_data(char *data
, int len
)
1178 ssh2_pkt_adddata(data
, len
);
1179 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1180 pktout
.length
- pktout
.savedpos
);
1182 static void ssh2_pkt_addstring(char *data
)
1184 ssh2_pkt_addstring_start();
1185 ssh2_pkt_addstring_str(data
);
1187 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1190 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1193 fatalbox("out of memory");
1195 for (i
= 1; i
<= n
; i
++)
1196 p
[i
] = bignum_byte(b
, n
- i
);
1198 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1200 memmove(p
, p
+ i
, n
+ 1 - i
);
1204 static void ssh2_pkt_addmp(Bignum b
)
1208 p
= ssh2_mpint_fmt(b
, &len
);
1209 ssh2_pkt_addstring_start();
1210 ssh2_pkt_addstring_data(p
, len
);
1215 * Construct an SSH2 final-form packet: compress it, encrypt it,
1216 * put the MAC on it. Final packet, ready to be sent, is stored in
1217 * pktout.data. Total length is returned.
1219 static int ssh2_pkt_construct(void)
1221 int cipherblk
, maclen
, padding
, i
;
1222 static unsigned long outgoing_sequence
= 0;
1225 * Compress packet payload.
1228 unsigned char *newpayload
;
1231 if (cscomp
&& cscomp
!= &ssh_comp_none
) {
1232 debug(("Pre-compression payload:\n"));
1233 dmemdump(pktout
.data
+ 5, pktout
.length
- 5);
1236 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1237 &newpayload
, &newlen
)) {
1239 ssh2_pkt_adddata(newpayload
, newlen
);
1245 * Add padding. At least four bytes, and must also bring total
1246 * length (minus MAC) up to a multiple of the block size.
1248 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1249 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1252 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1253 maclen
= csmac ? csmac
->len
: 0;
1254 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1255 pktout
.data
[4] = padding
;
1256 for (i
= 0; i
< padding
; i
++)
1257 pktout
.data
[pktout
.length
+ i
] = random_byte();
1258 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1260 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1262 outgoing_sequence
++; /* whether or not we MACed */
1265 debug(("Sending packet len=%d\n", pktout
.length
+ padding
));
1266 dmemdump(pktout
.data
, pktout
.length
+ padding
);
1270 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1272 /* Ready-to-send packet starts at pktout.data. We return length. */
1273 return pktout
.length
+ padding
+ maclen
;
1277 * Construct and send an SSH2 packet immediately.
1279 static void ssh2_pkt_send(void)
1283 len
= ssh2_pkt_construct();
1284 backlog
= sk_write(s
, pktout
.data
, len
);
1285 if (backlog
> SSH_MAX_BACKLOG
)
1286 ssh_throttle_all(1, backlog
);
1290 * Construct an SSH2 packet and add it to a deferred data block.
1291 * Useful for sending multiple packets in a single sk_write() call,
1292 * to prevent a traffic-analysing listener from being able to work
1293 * out the length of any particular packet (such as the password
1296 * Note that because SSH2 sequence-numbers its packets, this can
1297 * NOT be used as an m4-style `defer' allowing packets to be
1298 * constructed in one order and sent in another.
1300 static void ssh2_pkt_defer(void)
1302 int len
= ssh2_pkt_construct();
1303 if (deferred_len
+ len
> deferred_size
) {
1304 deferred_size
= deferred_len
+ len
+ 128;
1305 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1307 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1308 deferred_len
+= len
;
1312 * Send the whole deferred data block constructed by
1313 * ssh2_pkt_defer() or SSH1's defer_packet().
1315 static void ssh_pkt_defersend(void)
1318 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1319 deferred_len
= deferred_size
= 0;
1320 sfree(deferred_send_data
);
1321 deferred_send_data
= NULL
;
1322 if (backlog
> SSH_MAX_BACKLOG
)
1323 ssh_throttle_all(1, backlog
);
1327 void bndebug(char *string
, Bignum b
)
1331 p
= ssh2_mpint_fmt(b
, &len
);
1332 debug(("%s", string
));
1333 for (i
= 0; i
< len
; i
++)
1334 debug((" %02x", p
[i
]));
1340 static void sha_mpint(SHA_State
* s
, Bignum b
)
1344 p
= ssh2_mpint_fmt(b
, &len
);
1345 sha_string(s
, p
, len
);
1350 * SSH2 packet decode functions.
1352 static unsigned long ssh2_pkt_getuint32(void)
1354 unsigned long value
;
1355 if (pktin
.length
- pktin
.savedpos
< 4)
1356 return 0; /* arrgh, no way to decline (FIXME?) */
1357 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1358 pktin
.savedpos
+= 4;
1361 static int ssh2_pkt_getbool(void)
1363 unsigned long value
;
1364 if (pktin
.length
- pktin
.savedpos
< 1)
1365 return 0; /* arrgh, no way to decline (FIXME?) */
1366 value
= pktin
.data
[pktin
.savedpos
] != 0;
1370 static void ssh2_pkt_getstring(char **p
, int *length
)
1373 if (pktin
.length
- pktin
.savedpos
< 4)
1375 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1376 pktin
.savedpos
+= 4;
1377 if (pktin
.length
- pktin
.savedpos
< *length
)
1379 *p
= pktin
.data
+ pktin
.savedpos
;
1380 pktin
.savedpos
+= *length
;
1382 static Bignum
ssh2_pkt_getmp(void)
1388 ssh2_pkt_getstring(&p
, &length
);
1392 bombout(("internal error: Can't handle negative mpints"));
1395 b
= bignum_from_bytes(p
, length
);
1400 * Examine the remote side's version string and compare it against
1401 * a list of known buggy implementations.
1403 static void ssh_detect_bugs(char *vstring
)
1405 char *imp
; /* pointer to implementation part */
1407 imp
+= strcspn(imp
, "-");
1409 imp
+= strcspn(imp
, "-");
1412 ssh_remote_bugs
= 0;
1414 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1415 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1416 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1418 * These versions don't support SSH1_MSG_IGNORE, so we have
1419 * to use a different defence against password length
1422 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1423 logevent("We believe remote version has SSH1 ignore bug");
1426 if (!strcmp(imp
, "Cisco-1.25")) {
1428 * These versions need a plain password sent; they can't
1429 * handle having a null and a random length of data after
1432 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1433 logevent("We believe remote version needs a plain SSH1 password");
1436 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1437 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1438 !strncmp(imp
, "2.1 ", 4)) {
1440 * These versions have the HMAC bug.
1442 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1443 logevent("We believe remote version has SSH2 HMAC bug");
1447 static int do_ssh_init(unsigned char c
)
1450 static char version
[10];
1451 static char *vstring
;
1452 static int vstrsize
;
1458 /* Search for the string "SSH-" in the input. */
1461 static const int transS
[] = { 1, 2, 2, 1 };
1462 static const int transH
[] = { 0, 0, 3, 0 };
1463 static const int transminus
[] = { 0, 0, 0, -1 };
1474 crReturn(1); /* get another character */
1478 vstring
= smalloc(vstrsize
);
1479 strcpy(vstring
, "SSH-");
1483 crReturn(1); /* get another char */
1484 if (vslen
>= vstrsize
- 1) {
1486 vstring
= srealloc(vstring
, vstrsize
);
1488 vstring
[vslen
++] = c
;
1493 } else if (i
< sizeof(version
) - 1)
1495 } else if (c
== '\n')
1499 ssh_agentfwd_enabled
= FALSE
;
1500 rdpkt2_state
.incoming_sequence
= 0;
1503 vlog
= smalloc(20 + vslen
);
1504 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1505 sprintf(vlog
, "Server version: %s", vstring
);
1507 ssh_detect_bugs(vstring
);
1511 * Server version "1.99" means we can choose whether we use v1
1512 * or v2 protocol. Choice is based on cfg.sshprot.
1514 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1516 * This is a v2 server. Begin v2 protocol.
1518 char verstring
[80], vlog
[100];
1519 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1520 SHA_Init(&exhashbase
);
1522 * Hash our version string and their version string.
1524 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1525 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1526 sprintf(vlog
, "We claim version: %s", verstring
);
1528 strcat(verstring
, "\n");
1529 logevent("Using SSH protocol version 2");
1530 sk_write(s
, verstring
, strlen(verstring
));
1531 ssh_protocol
= ssh2_protocol
;
1533 s_rdpkt
= ssh2_rdpkt
;
1536 * This is a v1 server. Begin v1 protocol.
1538 char verstring
[80], vlog
[100];
1539 sprintf(verstring
, "SSH-%s-%s",
1540 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1542 sprintf(vlog
, "We claim version: %s", verstring
);
1544 strcat(verstring
, "\n");
1545 logevent("Using SSH protocol version 1");
1546 sk_write(s
, verstring
, strlen(verstring
));
1547 ssh_protocol
= ssh1_protocol
;
1549 s_rdpkt
= ssh1_rdpkt
;
1551 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1558 static void ssh_gotdata(unsigned char *data
, int datalen
)
1563 * To begin with, feed the characters one by one to the
1564 * protocol initialisation / selection function do_ssh_init().
1565 * When that returns 0, we're done with the initial greeting
1566 * exchange and can move on to packet discipline.
1571 crReturnV
; /* more data please */
1572 ret
= do_ssh_init(*data
);
1580 * We emerge from that loop when the initial negotiation is
1581 * over and we have selected an s_rdpkt function. Now pass
1582 * everything to s_rdpkt, and then pass the resulting packets
1583 * to the proper protocol handler.
1588 while (datalen
> 0) {
1589 if (s_rdpkt(&data
, &datalen
) == 0) {
1590 if (ssh_state
== SSH_STATE_CLOSED
) {
1593 ssh_protocol(NULL
, 0, 1);
1594 if (ssh_state
== SSH_STATE_CLOSED
) {
1604 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1607 ssh_state
= SSH_STATE_CLOSED
;
1613 /* A socket error has occurred. */
1614 connection_fatal(error_msg
);
1616 /* Otherwise, the remote side closed the connection normally. */
1621 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1623 ssh_gotdata(data
, len
);
1624 if (ssh_state
== SSH_STATE_CLOSED
) {
1634 static void ssh_sent(Plug plug
, int bufsize
)
1637 * If the send backlog on the SSH socket itself clears, we
1638 * should unthrottle the whole world if it was throttled.
1640 if (bufsize
< SSH_MAX_BACKLOG
)
1641 ssh_throttle_all(0, bufsize
);
1645 * Connect to specified host and port.
1646 * Returns an error message, or NULL on success.
1647 * Also places the canonical host name into `realhost'. It must be
1648 * freed by the caller.
1650 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1652 static struct plug_function_table fn_table
= {
1657 }, *fn_table_ptr
= &fn_table
;
1666 savedhost
= smalloc(1 + strlen(host
));
1668 fatalbox("Out of memory");
1669 strcpy(savedhost
, host
);
1672 port
= 22; /* default ssh port */
1687 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1690 addr
= sk_namelookup(host
, realhost
);
1691 if ((err
= sk_addr_error(addr
)))
1695 *realhost
= strdup(FWhost
);
1702 char buf
[200], addrbuf
[100];
1703 sk_getaddr(addr
, addrbuf
, 100);
1704 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1707 s
= sk_new(addr
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1708 if ((err
= sk_socket_error(s
)))
1712 sk_write(s
, "connect ", 8);
1713 sk_write(s
, FWhost
, strlen(FWhost
));
1716 sprintf(buf
, " %d\n", FWport
);
1717 sk_write(s
, buf
, strlen(buf
));
1725 * Throttle or unthrottle the SSH connection.
1727 static void ssh1_throttle(int adjust
)
1729 int old_count
= ssh1_throttle_count
;
1730 ssh1_throttle_count
+= adjust
;
1731 assert(ssh1_throttle_count
>= 0);
1732 if (ssh1_throttle_count
&& !old_count
) {
1733 sk_set_frozen(s
, 1);
1734 } else if (!ssh1_throttle_count
&& old_count
) {
1735 sk_set_frozen(s
, 0);
1740 * Throttle or unthrottle _all_ local data streams (for when sends
1741 * on the SSH connection itself back up).
1743 static void ssh_throttle_all(int enable
, int bufsize
)
1746 struct ssh_channel
*c
;
1748 if (enable
== ssh_throttled_all
)
1750 ssh_throttled_all
= enable
;
1751 ssh_overall_bufsize
= bufsize
;
1754 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
1756 case CHAN_MAINSESSION
:
1758 * This is treated separately, outside the switch.
1762 x11_override_throttle(c
->u
.x11
.s
, enable
);
1765 /* Agent channels require no buffer management. */
1768 pfd_override_throttle(c
->u
.x11
.s
, enable
);
1775 * Handle the key exchange and user authentication phases.
1777 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1781 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
1782 unsigned char cookie
[8];
1783 struct RSAKey servkey
, hostkey
;
1784 struct MD5Context md5c
;
1785 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1786 static int tried_publickey
;
1787 static int tis_auth_refused
, ccard_auth_refused
;
1788 static unsigned char session_id
[16];
1789 static int cipher_type
;
1790 static char username
[100];
1797 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1798 bombout(("Public key packet not received"));
1802 logevent("Received public keys");
1804 memcpy(cookie
, pktin
.body
, 8);
1806 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1807 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
1810 * Log the host key fingerprint.
1814 logevent("Host key fingerprint is:");
1815 strcpy(logmsg
, " ");
1816 hostkey
.comment
= NULL
;
1817 rsa_fingerprint(logmsg
+ strlen(logmsg
),
1818 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
1822 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
1823 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
1824 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
1826 ssh1_local_protoflags
=
1827 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1828 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1831 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1832 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1833 MD5Update(&md5c
, pktin
.body
, 8);
1834 MD5Final(session_id
, &md5c
);
1836 for (i
= 0; i
< 32; i
++)
1837 session_key
[i
] = random_byte();
1839 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1841 rsabuf
= smalloc(len
);
1843 fatalbox("Out of memory");
1846 * Verify the host key.
1850 * First format the key into a string.
1852 int len
= rsastr_len(&hostkey
);
1853 char fingerprint
[100];
1854 char *keystr
= smalloc(len
);
1856 fatalbox("Out of memory");
1857 rsastr_fmt(keystr
, &hostkey
);
1858 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1859 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
1864 for (i
= 0; i
< 32; i
++) {
1865 rsabuf
[i
] = session_key
[i
];
1867 rsabuf
[i
] ^= session_id
[i
];
1870 if (hostkey
.bytes
> servkey
.bytes
) {
1871 rsaencrypt(rsabuf
, 32, &servkey
);
1872 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1874 rsaencrypt(rsabuf
, 32, &hostkey
);
1875 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1878 logevent("Encrypted session key");
1881 int cipher_chosen
= 0, warn
= 0;
1882 char *cipher_string
= NULL
;
1883 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
1884 int next_cipher
= cfg
.ssh_cipherlist
[i
];
1885 if (next_cipher
== CIPHER_WARN
) {
1886 /* If/when we choose a cipher, warn about it */
1888 } else if (next_cipher
== CIPHER_AES
) {
1889 /* XXX Probably don't need to mention this. */
1890 logevent("AES not supported in SSH1, skipping");
1892 switch (next_cipher
) {
1893 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
1894 cipher_string
= "3DES"; break;
1895 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
1896 cipher_string
= "Blowfish"; break;
1897 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
1898 cipher_string
= "single-DES"; break;
1900 if (supported_ciphers_mask
& (1 << cipher_type
))
1904 if (!cipher_chosen
) {
1905 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
1906 bombout(("Server violates SSH 1 protocol by not "
1907 "supporting 3DES encryption"));
1909 /* shouldn't happen */
1910 bombout(("No supported ciphers found"));
1914 /* Warn about chosen cipher if necessary. */
1916 askcipher(cipher_string
, 0);
1919 switch (cipher_type
) {
1920 case SSH_CIPHER_3DES
:
1921 logevent("Using 3DES encryption");
1923 case SSH_CIPHER_DES
:
1924 logevent("Using single-DES encryption");
1926 case SSH_CIPHER_BLOWFISH
:
1927 logevent("Using Blowfish encryption");
1931 send_packet(SSH1_CMSG_SESSION_KEY
,
1932 PKT_CHAR
, cipher_type
,
1933 PKT_DATA
, cookie
, 8,
1934 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
1935 PKT_DATA
, rsabuf
, len
,
1936 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
1938 logevent("Trying to enable encryption...");
1942 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1943 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
1944 cipher
->sesskey(session_key
);
1948 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1949 bombout(("Encryption not successfully enabled"));
1953 logevent("Successfully started encryption");
1959 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1961 if (!ssh_get_line("login as: ",
1962 username
, sizeof(username
), FALSE
)) {
1964 * get_line failed to get a username.
1967 logevent("No username provided. Abandoning session.");
1968 ssh_state
= SSH_STATE_CLOSED
;
1972 c_write_str("login as: ");
1975 crWaitUntil(!ispkt
);
1977 switch (c
= *in
++) {
1986 c_write_str("\b \b");
1993 c_write_str("\b \b");
2003 if (((c
>= ' ' && c
<= '~') ||
2004 ((unsigned char) c
>= 160))
2005 && pos
< sizeof(username
)-1) {
2006 username
[pos
++] = c
;
2012 c_write_str("\r\n");
2013 username
[strcspn(username
, "\n\r")] = '\0';
2016 strncpy(username
, cfg
.username
, 99);
2017 username
[99] = '\0';
2020 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2022 char userlog
[22 + sizeof(username
)];
2023 sprintf(userlog
, "Sent username \"%s\"", username
);
2025 if (flags
& FLAG_INTERACTIVE
&&
2026 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2027 strcat(userlog
, "\r\n");
2028 c_write_str(userlog
);
2035 tried_publickey
= 0;
2036 tis_auth_refused
= ccard_auth_refused
= 0;
2038 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2039 static char password
[100];
2040 static char prompt
[200];
2043 static int pwpkt_type
;
2044 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2046 if (agent_exists()) {
2048 * Attempt RSA authentication using Pageant.
2050 static unsigned char request
[5], *response
, *p
;
2051 static int responselen
;
2052 static int i
, nkeys
;
2053 static int authed
= FALSE
;
2056 logevent("Pageant is running. Requesting keys.");
2058 /* Request the keys held by the agent. */
2059 PUT_32BIT(request
, 1);
2060 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2061 agent_query(request
, 5, &r
, &responselen
);
2062 response
= (unsigned char *) r
;
2063 if (response
&& responselen
>= 5 &&
2064 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2066 nkeys
= GET_32BIT(p
);
2070 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2073 for (i
= 0; i
< nkeys
; i
++) {
2074 static struct RSAKey key
;
2075 static Bignum challenge
;
2076 static char *commentp
;
2077 static int commentlen
;
2081 sprintf(buf
, "Trying Pageant key #%d", i
);
2085 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2086 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2087 commentlen
= GET_32BIT(p
);
2091 send_packet(SSH1_CMSG_AUTH_RSA
,
2092 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2094 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2095 logevent("Key refused");
2098 logevent("Received RSA challenge");
2099 ssh1_read_bignum(pktin
.body
, &challenge
);
2101 char *agentreq
, *q
, *ret
;
2104 len
= 1 + 4; /* message type, bit count */
2105 len
+= ssh1_bignum_length(key
.exponent
);
2106 len
+= ssh1_bignum_length(key
.modulus
);
2107 len
+= ssh1_bignum_length(challenge
);
2108 len
+= 16; /* session id */
2109 len
+= 4; /* response format */
2110 agentreq
= smalloc(4 + len
);
2111 PUT_32BIT(agentreq
, len
);
2113 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2114 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2116 q
+= ssh1_write_bignum(q
, key
.exponent
);
2117 q
+= ssh1_write_bignum(q
, key
.modulus
);
2118 q
+= ssh1_write_bignum(q
, challenge
);
2119 memcpy(q
, session_id
, 16);
2121 PUT_32BIT(q
, 1); /* response format */
2122 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2126 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2127 logevent("Sending Pageant's response");
2128 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2129 PKT_DATA
, ret
+ 5, 16,
2133 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2135 ("Pageant's response accepted");
2136 if (flags
& FLAG_VERBOSE
) {
2138 ("Authenticated using RSA key \"");
2139 c_write(commentp
, commentlen
);
2140 c_write_str("\" from agent\r\n");
2145 ("Pageant's response not accepted");
2148 ("Pageant failed to answer challenge");
2152 logevent("No reply received from Pageant");
2155 freebn(key
.exponent
);
2156 freebn(key
.modulus
);
2165 if (*cfg
.keyfile
&& !tried_publickey
)
2166 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2168 if (cfg
.try_tis_auth
&&
2169 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2170 !tis_auth_refused
) {
2171 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2172 logevent("Requested TIS authentication");
2173 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2175 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2176 logevent("TIS authentication declined");
2177 if (flags
& FLAG_INTERACTIVE
)
2178 c_write_str("TIS authentication refused.\r\n");
2179 tis_auth_refused
= 1;
2182 int challengelen
= ((pktin
.body
[0] << 24) |
2183 (pktin
.body
[1] << 16) |
2184 (pktin
.body
[2] << 8) |
2186 logevent("Received TIS challenge");
2187 if (challengelen
> sizeof(prompt
) - 1)
2188 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2189 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2190 /* Prompt heuristic comes from OpenSSH */
2191 strncpy(prompt
+ challengelen
,
2192 memchr(prompt
, '\n', challengelen
) ?
2193 "": "\r\nResponse: ",
2194 (sizeof prompt
) - challengelen
);
2195 prompt
[(sizeof prompt
) - 1] = '\0';
2198 if (cfg
.try_tis_auth
&&
2199 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2200 !ccard_auth_refused
) {
2201 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2202 logevent("Requested CryptoCard authentication");
2203 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2205 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2206 logevent("CryptoCard authentication declined");
2207 c_write_str("CryptoCard authentication refused.\r\n");
2208 ccard_auth_refused
= 1;
2211 int challengelen
= ((pktin
.body
[0] << 24) |
2212 (pktin
.body
[1] << 16) |
2213 (pktin
.body
[2] << 8) |
2215 logevent("Received CryptoCard challenge");
2216 if (challengelen
> sizeof(prompt
) - 1)
2217 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2218 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2219 strncpy(prompt
+ challengelen
,
2220 memchr(prompt
, '\n', challengelen
) ?
2221 "" : "\r\nResponse: ",
2222 sizeof(prompt
) - challengelen
);
2223 prompt
[sizeof(prompt
) - 1] = '\0';
2226 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2227 sprintf(prompt
, "%.90s@%.90s's password: ",
2228 username
, savedhost
);
2230 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2231 char *comment
= NULL
;
2232 if (flags
& FLAG_VERBOSE
)
2233 c_write_str("Trying public key authentication.\r\n");
2234 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2235 if (flags
& FLAG_VERBOSE
)
2236 c_write_str("No passphrase required.\r\n");
2239 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2244 * Show password prompt, having first obtained it via a TIS
2245 * or CryptoCard exchange if we're doing TIS or CryptoCard
2249 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2251 * get_line failed to get a password (for example
2252 * because one was supplied on the command line
2253 * which has already failed to work). Terminate.
2255 send_packet(SSH1_MSG_DISCONNECT
,
2256 PKT_STR
, "No more passwords available to try",
2258 connection_fatal("Unable to authenticate");
2259 ssh_state
= SSH_STATE_CLOSED
;
2263 /* Prompt may have come from server. We've munged it a bit, so
2264 * we know it to be zero-terminated at least once. */
2265 c_write_untrusted(prompt
, strlen(prompt
));
2269 crWaitUntil(!ispkt
);
2271 switch (c
= *in
++) {
2292 if (pos
< sizeof(password
)-1)
2293 password
[pos
++] = c
;
2297 c_write_str("\r\n");
2301 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2303 * Try public key authentication with the specified
2306 static struct RSAKey pubkey
;
2307 static Bignum challenge
, response
;
2309 static unsigned char buffer
[32];
2311 tried_publickey
= 1;
2312 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2314 c_write_str("Couldn't load private key from ");
2315 c_write_str(cfg
.keyfile
);
2316 c_write_str(".\r\n");
2317 continue; /* go and try password */
2320 c_write_str("Wrong passphrase.\r\n");
2321 tried_publickey
= 0;
2322 continue; /* try again */
2326 * Send a public key attempt.
2328 send_packet(SSH1_CMSG_AUTH_RSA
,
2329 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2332 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2333 c_write_str("Server refused our public key.\r\n");
2334 continue; /* go and try password */
2336 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2337 bombout(("Bizarre response to offer of public key"));
2340 ssh1_read_bignum(pktin
.body
, &challenge
);
2341 response
= rsadecrypt(challenge
, &pubkey
);
2342 freebn(pubkey
.private_exponent
); /* burn the evidence */
2344 for (i
= 0; i
< 32; i
++) {
2345 buffer
[i
] = bignum_byte(response
, 31 - i
);
2349 MD5Update(&md5c
, buffer
, 32);
2350 MD5Update(&md5c
, session_id
, 16);
2351 MD5Final(buffer
, &md5c
);
2353 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2354 PKT_DATA
, buffer
, 16, PKT_END
);
2357 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2358 if (flags
& FLAG_VERBOSE
)
2360 ("Failed to authenticate with our public key.\r\n");
2361 continue; /* go and try password */
2362 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2364 ("Bizarre response to RSA authentication response"));
2368 break; /* we're through! */
2370 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2372 * Defence against traffic analysis: we send a
2373 * whole bunch of packets containing strings of
2374 * different lengths. One of these strings is the
2375 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2376 * The others are all random data in
2377 * SSH1_MSG_IGNORE packets. This way a passive
2378 * listener can't tell which is the password, and
2379 * hence can't deduce the password length.
2381 * Anybody with a password length greater than 16
2382 * bytes is going to have enough entropy in their
2383 * password that a listener won't find it _that_
2384 * much help to know how long it is. So what we'll
2387 * - if password length < 16, we send 15 packets
2388 * containing string lengths 1 through 15
2390 * - otherwise, we let N be the nearest multiple
2391 * of 8 below the password length, and send 8
2392 * packets containing string lengths N through
2393 * N+7. This won't obscure the order of
2394 * magnitude of the password length, but it will
2395 * introduce a bit of extra uncertainty.
2397 * A few servers (the old 1.2.18 through 1.2.22)
2398 * can't deal with SSH1_MSG_IGNORE. For these
2399 * servers, we need an alternative defence. We make
2400 * use of the fact that the password is interpreted
2401 * as a C string: so we can append a NUL, then some
2404 * One server (a Cisco one) can deal with neither
2405 * SSH1_MSG_IGNORE _nor_ a padded password string.
2406 * For this server we are left with no defences
2407 * against password length sniffing.
2409 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2411 * The server can deal with SSH1_MSG_IGNORE, so
2412 * we can use the primary defence.
2414 int bottom
, top
, pwlen
, i
;
2417 pwlen
= strlen(password
);
2419 bottom
= 0; /* zero length passwords are OK! :-) */
2422 bottom
= pwlen
& ~7;
2426 assert(pwlen
>= bottom
&& pwlen
<= top
);
2428 randomstr
= smalloc(top
+ 1);
2430 for (i
= bottom
; i
<= top
; i
++) {
2432 defer_packet(pwpkt_type
, PKT_STR
, password
,
2435 for (j
= 0; j
< i
; j
++) {
2437 randomstr
[j
] = random_byte();
2438 } while (randomstr
[j
] == '\0');
2440 randomstr
[i
] = '\0';
2441 defer_packet(SSH1_MSG_IGNORE
,
2442 PKT_STR
, randomstr
, PKT_END
);
2445 logevent("Sending password with camouflage packets");
2446 ssh_pkt_defersend();
2448 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2450 * The server can't deal with SSH1_MSG_IGNORE
2451 * but can deal with padded passwords, so we
2452 * can use the secondary defence.
2458 len
= strlen(password
);
2459 if (len
< sizeof(string
)) {
2461 strcpy(string
, password
);
2462 len
++; /* cover the zero byte */
2463 while (len
< sizeof(string
)) {
2464 string
[len
++] = (char) random_byte();
2469 logevent("Sending length-padded password");
2470 send_packet(pwpkt_type
, PKT_INT
, len
,
2471 PKT_DATA
, s
, len
, PKT_END
);
2474 * The server has _both_
2475 * BUG_CHOKES_ON_SSH1_IGNORE and
2476 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2477 * therefore nothing we can do.
2480 len
= strlen(password
);
2481 logevent("Sending unpadded password");
2482 send_packet(pwpkt_type
, PKT_INT
, len
,
2483 PKT_DATA
, password
, len
, PKT_END
);
2486 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2489 logevent("Sent password");
2490 memset(password
, 0, strlen(password
));
2492 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2493 if (flags
& FLAG_VERBOSE
)
2494 c_write_str("Access denied\r\n");
2495 logevent("Authentication refused");
2496 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2497 logevent("Received disconnect request");
2498 ssh_state
= SSH_STATE_CLOSED
;
2500 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2501 bombout(("Strange packet received, type %d", pktin
.type
));
2506 logevent("Authentication successful");
2511 void sshfwd_close(struct ssh_channel
*c
)
2513 if (c
&& !c
->closes
) {
2515 * If the channel's remoteid is -1, we have sent
2516 * CHANNEL_OPEN for this channel, but it hasn't even been
2517 * acknowledged by the server. So we must set a close flag
2518 * on it now, and then when the server acks the channel
2519 * open, we can close it then.
2521 if (c
->remoteid
!= -1) {
2522 if (ssh_version
== 1) {
2523 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2526 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2527 ssh2_pkt_adduint32(c
->remoteid
);
2532 if (c
->type
== CHAN_X11
) {
2534 logevent("Forwarded X11 connection terminated");
2535 } else if (c
->type
== CHAN_SOCKDATA
||
2536 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2538 logevent("Forwarded port closed");
2543 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2545 if (ssh_version
== 1) {
2546 send_packet(SSH1_MSG_CHANNEL_DATA
,
2547 PKT_INT
, c
->remoteid
,
2548 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2550 * In SSH1 we can return 0 here - implying that forwarded
2551 * connections are never individually throttled - because
2552 * the only circumstance that can cause throttling will be
2553 * the whole SSH connection backing up, in which case
2554 * _everything_ will be throttled as a whole.
2558 ssh2_add_channel_data(c
, buf
, len
);
2559 return ssh2_try_send(c
);
2563 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2565 if (ssh_version
== 1) {
2566 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2567 c
->v
.v1
.throttling
= 0;
2571 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2575 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2581 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2584 if (ssh_state
== SSH_STATE_CLOSED
)
2587 if (cfg
.agentfwd
&& agent_exists()) {
2588 logevent("Requesting agent forwarding");
2589 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2593 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2594 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2595 bombout(("Protocol confusion"));
2597 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2598 logevent("Agent forwarding refused");
2600 logevent("Agent forwarding enabled");
2601 ssh_agentfwd_enabled
= TRUE
;
2605 if (cfg
.x11_forward
) {
2606 char proto
[20], data
[64];
2607 logevent("Requesting X11 forwarding");
2608 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2609 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2610 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2611 PKT_STR
, proto
, PKT_STR
, data
,
2612 PKT_INT
, 0, PKT_END
);
2614 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2615 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2620 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2621 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2622 bombout(("Protocol confusion"));
2624 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2625 logevent("X11 forwarding refused");
2627 logevent("X11 forwarding enabled");
2628 ssh_X11_fwd_enabled
= TRUE
;
2636 char sports
[256], dports
[256], host
[256];
2639 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2640 /* Add port forwardings. */
2645 while (*e
&& *e
!= '\t')
2651 while (*e
&& *e
!= ':')
2661 dport
= atoi(dports
);
2662 sport
= atoi(sports
);
2663 if (sport
&& dport
) {
2665 pfd_addforward(host
, dport
, sport
);
2666 sprintf(buf
, "Local port %d forwarding to %s:%d",
2667 sport
, host
, dport
);
2670 struct ssh_rportfwd
*pf
;
2671 pf
= smalloc(sizeof(*pf
));
2672 strcpy(pf
->dhost
, host
);
2674 if (add234(ssh_rportfwds
, pf
) != pf
) {
2676 "Duplicate remote port forwarding to %s:%d",
2681 sprintf(buf
, "Requesting remote port %d forward to %s:%d",
2682 sport
, host
, dport
);
2684 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2696 send_packet(SSH1_CMSG_REQUEST_PTY
,
2697 PKT_STR
, cfg
.termtype
,
2698 PKT_INT
, rows
, PKT_INT
, cols
,
2699 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2700 ssh_state
= SSH_STATE_INTERMED
;
2704 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2705 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2706 bombout(("Protocol confusion"));
2708 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2709 c_write_str("Server refused to allocate pty\r\n");
2710 ssh_editing
= ssh_echoing
= 1;
2712 logevent("Allocated pty");
2714 ssh_editing
= ssh_echoing
= 1;
2717 if (cfg
.compression
) {
2718 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2722 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2723 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2724 bombout(("Protocol confusion"));
2726 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2727 c_write_str("Server refused to compress\r\n");
2729 logevent("Started compression");
2730 ssh1_compressing
= TRUE
;
2731 zlib_compress_init();
2732 zlib_decompress_init();
2736 * Start the shell or command.
2738 * Special case: if the first-choice command is an SSH2
2739 * subsystem (hence not usable here) and the second choice
2740 * exists, we fall straight back to that.
2743 char *cmd
= cfg
.remote_cmd_ptr
;
2745 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
2746 cmd
= cfg
.remote_cmd_ptr2
;
2747 ssh_fallback_cmd
= TRUE
;
2750 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2752 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2753 logevent("Started session");
2756 ssh_state
= SSH_STATE_SESSION
;
2760 ssh_special(TS_EOF
);
2762 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
2764 ssh_channels
= newtree234(ssh_channelcmp
);
2768 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2769 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2770 long len
= GET_32BIT(pktin
.body
);
2772 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2773 pktin
.body
+ 4, len
);
2774 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2775 ssh1_stdout_throttling
= 1;
2778 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2779 ssh_state
= SSH_STATE_CLOSED
;
2780 logevent("Received disconnect request");
2782 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2783 /* Remote side is trying to open a channel to talk to our
2784 * X-Server. Give them back a local channel number. */
2785 struct ssh_channel
*c
;
2787 logevent("Received X11 connect request");
2788 /* Refuse if X11 forwarding is disabled. */
2789 if (!ssh_X11_fwd_enabled
) {
2790 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2791 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2792 logevent("Rejected X11 connect request");
2794 c
= smalloc(sizeof(struct ssh_channel
));
2796 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2797 logevent("opening X11 forward connection failed");
2799 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2800 PKT_INT
, GET_32BIT(pktin
.body
),
2804 ("opening X11 forward connection succeeded");
2805 c
->remoteid
= GET_32BIT(pktin
.body
);
2806 c
->localid
= alloc_channel_id();
2808 c
->v
.v1
.throttling
= 0;
2809 c
->type
= CHAN_X11
; /* identify channel type */
2810 add234(ssh_channels
, c
);
2811 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2812 PKT_INT
, c
->remoteid
, PKT_INT
,
2813 c
->localid
, PKT_END
);
2814 logevent("Opened X11 forward channel");
2817 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2818 /* Remote side is trying to open a channel to talk to our
2819 * agent. Give them back a local channel number. */
2820 struct ssh_channel
*c
;
2822 /* Refuse if agent forwarding is disabled. */
2823 if (!ssh_agentfwd_enabled
) {
2824 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2825 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2827 c
= smalloc(sizeof(struct ssh_channel
));
2828 c
->remoteid
= GET_32BIT(pktin
.body
);
2829 c
->localid
= alloc_channel_id();
2831 c
->v
.v1
.throttling
= 0;
2832 c
->type
= CHAN_AGENT
; /* identify channel type */
2833 c
->u
.a
.lensofar
= 0;
2834 add234(ssh_channels
, c
);
2835 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2836 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2839 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
2840 /* Remote side is trying to open a channel to talk to a
2841 * forwarded port. Give them back a local channel number. */
2842 struct ssh_channel
*c
;
2843 struct ssh_rportfwd pf
;
2845 char host
[256], buf
[1024];
2847 c
= smalloc(sizeof(struct ssh_channel
));
2849 hostsize
= GET_32BIT(pktin
.body
+4);
2850 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
2851 if (h
+1 < host
+sizeof(host
))
2856 port
= GET_32BIT(p
);
2858 strcpy(pf
.dhost
, host
);
2861 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
2862 sprintf(buf
, "Rejected remote port open request for %s:%d",
2865 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2866 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2868 sprintf(buf
, "Received remote port open request for %s:%d",
2871 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
2874 sprintf(buf
, "Port open failed: %s", e
);
2877 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2878 PKT_INT
, GET_32BIT(pktin
.body
),
2881 c
->remoteid
= GET_32BIT(pktin
.body
);
2882 c
->localid
= alloc_channel_id();
2884 c
->v
.v1
.throttling
= 0;
2885 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
2886 add234(ssh_channels
, c
);
2887 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2888 PKT_INT
, c
->remoteid
, PKT_INT
,
2889 c
->localid
, PKT_END
);
2890 logevent("Forwarded port opened successfully");
2894 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2895 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2896 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2897 struct ssh_channel
*c
;
2899 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2900 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2901 c
->remoteid
= localid
;
2902 c
->type
= CHAN_SOCKDATA
;
2903 c
->v
.v1
.throttling
= 0;
2904 pfd_confirm(c
->u
.pfd
.s
);
2907 if (c
&& c
->closes
) {
2909 * We have a pending close on this channel,
2910 * which we decided on before the server acked
2911 * the channel open. So now we know the
2912 * remoteid, we can close it again.
2914 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2918 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
2919 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2920 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2921 struct ssh_channel
*c
;
2923 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2924 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2925 logevent("Forwarded connection refused by server");
2926 pfd_close(c
->u
.pfd
.s
);
2927 del234(ssh_channels
, c
);
2931 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
2932 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
2933 /* Remote side closes a channel. */
2934 unsigned i
= GET_32BIT(pktin
.body
);
2935 struct ssh_channel
*c
;
2936 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2940 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
2941 if (!(c
->closes
& closetype
))
2942 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
2944 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
2945 logevent("Forwarded X11 connection terminated");
2946 assert(c
->u
.x11
.s
!= NULL
);
2947 x11_close(c
->u
.x11
.s
);
2950 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
2951 logevent("Forwarded port closed");
2952 assert(c
->u
.pfd
.s
!= NULL
);
2953 pfd_close(c
->u
.pfd
.s
);
2956 c
->closes
|= closetype
;
2957 if (c
->closes
== 3) {
2958 del234(ssh_channels
, c
);
2962 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
2963 /* Data sent down one of our channels. */
2964 int i
= GET_32BIT(pktin
.body
);
2965 int len
= GET_32BIT(pktin
.body
+ 4);
2966 unsigned char *p
= pktin
.body
+ 8;
2967 struct ssh_channel
*c
;
2968 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2973 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
2976 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
2979 /* Data for an agent message. Buffer it. */
2981 if (c
->u
.a
.lensofar
< 4) {
2982 int l
= min(4 - c
->u
.a
.lensofar
, len
);
2983 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
2987 c
->u
.a
.lensofar
+= l
;
2989 if (c
->u
.a
.lensofar
== 4) {
2991 4 + GET_32BIT(c
->u
.a
.msglen
);
2992 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
2993 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
2995 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
2997 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
2999 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3003 c
->u
.a
.lensofar
+= l
;
3005 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3006 void *reply
, *sentreply
;
3008 agent_query(c
->u
.a
.message
,
3009 c
->u
.a
.totallen
, &reply
,
3014 /* Fake SSH_AGENT_FAILURE. */
3015 sentreply
= "\0\0\0\1\5";
3018 send_packet(SSH1_MSG_CHANNEL_DATA
,
3019 PKT_INT
, c
->remoteid
,
3021 PKT_DATA
, sentreply
, replylen
,
3025 sfree(c
->u
.a
.message
);
3026 c
->u
.a
.lensofar
= 0;
3029 bufsize
= 0; /* agent channels never back up */
3032 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3033 c
->v
.v1
.throttling
= 1;
3037 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3038 /* may be from EXEC_SHELL on some servers */
3039 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3040 /* may be from EXEC_SHELL on some servers
3041 * if no pty is available or in other odd cases. Ignore */
3042 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3043 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3045 * In case `helpful' firewalls or proxies tack
3046 * extra human-readable text on the end of the
3047 * session which we might mistake for another
3048 * encrypted packet, we close the session once
3049 * we've sent EXIT_CONFIRMATION.
3051 ssh_state
= SSH_STATE_CLOSED
;
3054 bombout(("Strange packet received: type %d", pktin
.type
));
3059 int len
= min(inlen
, 512);
3060 send_packet(SSH1_CMSG_STDIN_DATA
,
3061 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3072 * Utility routine for decoding comma-separated strings in KEXINIT.
3074 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3076 int needlen
= strlen(needle
);
3079 * Is it at the start of the string?
3081 if (haylen
>= needlen
&& /* haystack is long enough */
3082 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3083 (haylen
== needlen
|| haystack
[needlen
] == ',')
3084 /* either , or EOS follows */
3088 * If not, search for the next comma and resume after that.
3089 * If no comma found, terminate.
3091 while (haylen
> 0 && *haystack
!= ',')
3092 haylen
--, haystack
++;
3095 haylen
--, haystack
++; /* skip over comma itself */
3100 * SSH2 key creation method.
3102 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3106 /* First 20 bytes. */
3109 SHA_Bytes(&s
, H
, 20);
3110 SHA_Bytes(&s
, &chr
, 1);
3111 SHA_Bytes(&s
, sessid
, 20);
3112 SHA_Final(&s
, keyspace
);
3113 /* Next 20 bytes. */
3116 SHA_Bytes(&s
, H
, 20);
3117 SHA_Bytes(&s
, keyspace
, 20);
3118 SHA_Final(&s
, keyspace
+ 20);
3122 * Handle the SSH2 transport layer.
3124 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3126 static int i
, j
, len
, nbits
, pbits
, warn
;
3128 static Bignum p
, g
, e
, f
, K
;
3129 static int kex_init_value
, kex_reply_value
;
3130 static const struct ssh_mac
**maclist
;
3132 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3133 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3134 static const struct ssh_mac
*csmac_tobe
= NULL
;
3135 static const struct ssh_mac
*scmac_tobe
= NULL
;
3136 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3137 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3138 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3139 static int hostkeylen
, siglen
;
3140 static void *hkey
; /* actual host key */
3141 static unsigned char exchange_hash
[20];
3142 static unsigned char keyspace
[40];
3143 static int n_preferred_ciphers
;
3144 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3145 static const struct ssh_compress
*preferred_comp
;
3146 static int cipherstr_started
;
3147 static int first_kex
;
3154 * Set up the preferred ciphers. (NULL => warn below here)
3156 n_preferred_ciphers
= 0;
3157 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3158 switch (cfg
.ssh_cipherlist
[i
]) {
3159 case CIPHER_BLOWFISH
:
3160 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3161 n_preferred_ciphers
++;
3164 if (cfg
.ssh2_des_cbc
) {
3165 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3166 n_preferred_ciphers
++;
3170 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3171 n_preferred_ciphers
++;
3174 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3175 n_preferred_ciphers
++;
3178 /* Flag for later. Don't bother if it's the last in
3180 if (i
< CIPHER_MAX
- 1) {
3181 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3182 n_preferred_ciphers
++;
3189 * Set up preferred compression.
3191 if (cfg
.compression
)
3192 preferred_comp
= &ssh_zlib
;
3194 preferred_comp
= &ssh_comp_none
;
3197 * Be prepared to work around the buggy MAC problem.
3199 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3200 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3202 maclist
= macs
, nmacs
= lenof(macs
);
3206 * Construct and send our key exchange packet.
3208 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3209 for (i
= 0; i
< 16; i
++)
3210 ssh2_pkt_addbyte((unsigned char) random_byte());
3211 /* List key exchange algorithms. */
3212 ssh2_pkt_addstring_start();
3213 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3214 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3215 if (i
< lenof(kex_algs
) - 1)
3216 ssh2_pkt_addstring_str(",");
3218 /* List server host key algorithms. */
3219 ssh2_pkt_addstring_start();
3220 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3221 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3222 if (i
< lenof(hostkey_algs
) - 1)
3223 ssh2_pkt_addstring_str(",");
3225 /* List client->server encryption algorithms. */
3226 ssh2_pkt_addstring_start();
3227 cipherstr_started
= 0;
3228 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3229 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3230 if (!c
) continue; /* warning flag */
3231 for (j
= 0; j
< c
->nciphers
; j
++) {
3232 if (cipherstr_started
)
3233 ssh2_pkt_addstring_str(",");
3234 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3235 cipherstr_started
= 1;
3238 /* List server->client encryption algorithms. */
3239 ssh2_pkt_addstring_start();
3240 cipherstr_started
= 0;
3241 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3242 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3243 if (!c
) continue; /* warning flag */
3244 for (j
= 0; j
< c
->nciphers
; j
++) {
3245 if (cipherstr_started
)
3246 ssh2_pkt_addstring_str(",");
3247 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3248 cipherstr_started
= 1;
3251 /* List client->server MAC algorithms. */
3252 ssh2_pkt_addstring_start();
3253 for (i
= 0; i
< nmacs
; i
++) {
3254 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3256 ssh2_pkt_addstring_str(",");
3258 /* List server->client MAC algorithms. */
3259 ssh2_pkt_addstring_start();
3260 for (i
= 0; i
< nmacs
; i
++) {
3261 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3263 ssh2_pkt_addstring_str(",");
3265 /* List client->server compression algorithms. */
3266 ssh2_pkt_addstring_start();
3267 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3268 const struct ssh_compress
*c
=
3269 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3270 ssh2_pkt_addstring_str(c
->name
);
3271 if (i
< lenof(compressions
))
3272 ssh2_pkt_addstring_str(",");
3274 /* List server->client compression algorithms. */
3275 ssh2_pkt_addstring_start();
3276 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3277 const struct ssh_compress
*c
=
3278 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3279 ssh2_pkt_addstring_str(c
->name
);
3280 if (i
< lenof(compressions
))
3281 ssh2_pkt_addstring_str(",");
3283 /* List client->server languages. Empty list. */
3284 ssh2_pkt_addstring_start();
3285 /* List server->client languages. Empty list. */
3286 ssh2_pkt_addstring_start();
3287 /* First KEX packet does _not_ follow, because we're not that brave. */
3288 ssh2_pkt_addbool(FALSE
);
3290 ssh2_pkt_adduint32(0);
3292 exhash
= exhashbase
;
3293 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3299 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3302 * Now examine the other side's KEXINIT to see what we're up
3305 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3306 bombout(("expected key exchange packet from server"));
3311 cscipher_tobe
= NULL
;
3312 sccipher_tobe
= NULL
;
3317 pktin
.savedpos
+= 16; /* skip garbage cookie */
3318 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3319 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3320 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3325 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3326 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3327 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3328 hostkey
= hostkey_algs
[i
];
3332 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3334 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3335 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3339 for (j
= 0; j
< c
->nciphers
; j
++) {
3340 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3341 cscipher_tobe
= c
->list
[j
];
3346 if (cscipher_tobe
) {
3348 askcipher(cscipher_tobe
->name
, 1);
3352 if (!cscipher_tobe
) {
3353 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3357 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3359 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3360 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3364 for (j
= 0; j
< c
->nciphers
; j
++) {
3365 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3366 sccipher_tobe
= c
->list
[j
];
3371 if (sccipher_tobe
) {
3373 askcipher(sccipher_tobe
->name
, 2);
3377 if (!sccipher_tobe
) {
3378 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3382 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3383 for (i
= 0; i
< nmacs
; i
++) {
3384 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3385 csmac_tobe
= maclist
[i
];
3389 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3390 for (i
= 0; i
< nmacs
; i
++) {
3391 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3392 scmac_tobe
= maclist
[i
];
3396 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3397 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3398 const struct ssh_compress
*c
=
3399 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3400 if (in_commasep_string(c
->name
, str
, len
)) {
3405 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3406 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3407 const struct ssh_compress
*c
=
3408 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3409 if (in_commasep_string(c
->name
, str
, len
)) {
3416 * Work out the number of bits of key we will need from the key
3417 * exchange. We start with the maximum key length of either
3423 csbits
= cscipher_tobe
->keylen
;
3424 scbits
= sccipher_tobe
->keylen
;
3425 nbits
= (csbits
> scbits ? csbits
: scbits
);
3427 /* The keys only have 160-bit entropy, since they're based on
3428 * a SHA-1 hash. So cap the key size at 160 bits. */
3433 * If we're doing Diffie-Hellman group exchange, start by
3434 * requesting a group.
3436 if (kex
== &ssh_diffiehellman_gex
) {
3437 logevent("Doing Diffie-Hellman group exchange");
3439 * Work out how big a DH group we will need to allow that
3442 pbits
= 512 << ((nbits
- 1) / 64);
3443 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3444 ssh2_pkt_adduint32(pbits
);
3448 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3449 bombout(("expected key exchange group packet from server"));
3452 p
= ssh2_pkt_getmp();
3453 g
= ssh2_pkt_getmp();
3454 dh_setup_group(p
, g
);
3455 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3456 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3459 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3460 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3463 logevent("Doing Diffie-Hellman key exchange");
3465 * Now generate and send e for Diffie-Hellman.
3467 e
= dh_create_e(nbits
* 2);
3468 ssh2_pkt_init(kex_init_value
);
3473 if (pktin
.type
!= kex_reply_value
) {
3474 bombout(("expected key exchange reply packet from server"));
3477 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3478 f
= ssh2_pkt_getmp();
3479 ssh2_pkt_getstring(&sigdata
, &siglen
);
3483 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3484 if (kex
== &ssh_diffiehellman_gex
) {
3485 sha_uint32(&exhash
, pbits
);
3486 sha_mpint(&exhash
, p
);
3487 sha_mpint(&exhash
, g
);
3489 sha_mpint(&exhash
, e
);
3490 sha_mpint(&exhash
, f
);
3491 sha_mpint(&exhash
, K
);
3492 SHA_Final(&exhash
, exchange_hash
);
3497 debug(("Exchange hash is:\n"));
3498 dmemdump(exchange_hash
, 20);
3501 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3503 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3504 bombout(("Server's host key did not match the signature supplied"));
3509 * Authenticate remote host: verify host key. (We've already
3510 * checked the signature of the exchange hash.)
3512 keystr
= hostkey
->fmtkey(hkey
);
3513 fingerprint
= hostkey
->fingerprint(hkey
);
3514 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3515 keystr
, fingerprint
);
3516 if (first_kex
) { /* don't bother logging this in rekeys */
3517 logevent("Host key fingerprint is:");
3518 logevent(fingerprint
);
3522 hostkey
->freekey(hkey
);
3525 * Send SSH2_MSG_NEWKEYS.
3527 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3531 * Expect SSH2_MSG_NEWKEYS from server.
3534 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3535 bombout(("expected new-keys packet from server"));
3540 * Create and initialise session keys.
3542 cscipher
= cscipher_tobe
;
3543 sccipher
= sccipher_tobe
;
3546 cscomp
= cscomp_tobe
;
3547 sccomp
= sccomp_tobe
;
3548 cscomp
->compress_init();
3549 sccomp
->decompress_init();
3551 * Set IVs after keys. Here we use the exchange hash from the
3552 * _first_ key exchange.
3555 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3556 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3557 cscipher
->setcskey(keyspace
);
3558 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3559 sccipher
->setsckey(keyspace
);
3560 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3561 cscipher
->setcsiv(keyspace
);
3562 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3563 sccipher
->setsciv(keyspace
);
3564 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3565 csmac
->setcskey(keyspace
);
3566 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3567 scmac
->setsckey(keyspace
);
3570 * If this is the first key exchange phase, we must pass the
3571 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3572 * wants to see it but because it will need time to initialise
3573 * itself before it sees an actual packet. In subsequent key
3574 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3575 * it would only confuse the layer above.
3583 * Now we're encrypting. Begin returning 1 to the protocol main
3584 * function so that other things can run on top of the
3585 * transport. If we ever see a KEXINIT, we must go back to the
3588 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3591 logevent("Server initiated key re-exchange");
3592 goto begin_key_exchange
;
3598 * Add data to an SSH2 channel output buffer.
3600 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3603 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3607 * Attempt to send data on an SSH2 channel.
3609 static int ssh2_try_send(struct ssh_channel
*c
)
3611 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3614 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3615 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3616 len
= c
->v
.v2
.remwindow
;
3617 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3618 len
= c
->v
.v2
.remmaxpkt
;
3619 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3620 ssh2_pkt_adduint32(c
->remoteid
);
3621 ssh2_pkt_addstring_start();
3622 ssh2_pkt_addstring_data(data
, len
);
3624 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3625 c
->v
.v2
.remwindow
-= len
;
3629 * After having sent as much data as we can, return the amount
3632 return bufchain_size(&c
->v
.v2
.outbuffer
);
3636 * Potentially enlarge the window on an SSH2 channel.
3638 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3640 if (newwin
> c
->v
.v2
.locwindow
) {
3641 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3642 ssh2_pkt_adduint32(c
->remoteid
);
3643 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3645 c
->v
.v2
.locwindow
= newwin
;
3650 * Handle the SSH2 userauth and connection layers.
3652 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3655 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3657 AUTH_KEYBOARD_INTERACTIVE
3661 AUTH_TYPE_PUBLICKEY
,
3662 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3663 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3665 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3666 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3668 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3669 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3670 static int kbd_inter_running
;
3671 static int we_are_in
;
3672 static int num_prompts
, echo
;
3673 static char username
[100];
3674 static char pwprompt
[200];
3675 static char password
[100];
3680 * Request userauth protocol, and await a response to it.
3682 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3683 ssh2_pkt_addstring("ssh-userauth");
3685 crWaitUntilV(ispkt
);
3686 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3687 bombout(("Server refused user authentication protocol"));
3692 * We repeat this whole loop, including the username prompt,
3693 * until we manage a successful authentication. If the user
3694 * types the wrong _password_, they are sent back to the
3695 * beginning to try another username. (If they specify a
3696 * username in the config, they are never asked, even if they
3697 * do give a wrong password.)
3699 * I think this best serves the needs of
3701 * - the people who have no configuration, no keys, and just
3702 * want to try repeated (username,password) pairs until they
3703 * type both correctly
3705 * - people who have keys and configuration but occasionally
3706 * need to fall back to passwords
3708 * - people with a key held in Pageant, who might not have
3709 * logged in to a particular machine before; so they want to
3710 * type a username, and then _either_ their key will be
3711 * accepted, _or_ they will type a password. If they mistype
3712 * the username they will want to be able to get back and
3724 if (*username
&& !cfg
.change_username
) {
3726 * We got a username last time round this loop, and
3727 * with change_username turned off we don't try to get
3730 } else if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
3732 if (!ssh_get_line("login as: ",
3733 username
, sizeof(username
), FALSE
)) {
3735 * get_line failed to get a username.
3738 logevent("No username provided. Abandoning session.");
3739 ssh_state
= SSH_STATE_CLOSED
;
3743 c_write_str("login as: ");
3746 crWaitUntilV(!ispkt
);
3748 switch (c
= *in
++) {
3757 c_write_str("\b \b");
3764 c_write_str("\b \b");
3774 if (((c
>= ' ' && c
<= '~') ||
3775 ((unsigned char) c
>= 160))
3776 && pos
< sizeof(username
)-1) {
3777 username
[pos
++] = c
;
3784 c_write_str("\r\n");
3785 username
[strcspn(username
, "\n\r")] = '\0';
3788 strncpy(username
, cfg
.username
, 99);
3789 username
[99] = '\0';
3790 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3791 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3797 * Send an authentication request using method "none": (a)
3798 * just in case it succeeds, and (b) so that we know what
3799 * authentication methods we can usefully try next.
3801 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3802 ssh2_pkt_addstring(username
);
3803 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3804 ssh2_pkt_addstring("none"); /* method */
3806 type
= AUTH_TYPE_NONE
;
3810 tried_pubkey_config
= FALSE
;
3811 tried_agent
= FALSE
;
3812 tried_keyb_inter
= FALSE
;
3813 kbd_inter_running
= FALSE
;
3817 * Wait for the result of the last authentication request.
3820 crWaitUntilV(ispkt
);
3821 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
3825 * Don't show the banner if we're operating in
3826 * non-verbose non-interactive mode. (It's probably
3827 * a script, which means nobody will read the
3828 * banner _anyway_, and moreover the printing of
3829 * the banner will screw up processing on the
3830 * output of (say) plink.)
3832 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
3833 ssh2_pkt_getstring(&banner
, &size
);
3835 c_write_untrusted(banner
, size
);
3837 crWaitUntilV(ispkt
);
3839 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
3840 logevent("Access granted");
3845 if (kbd_inter_running
&&
3846 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
3848 * This is a further prompt in keyboard-interactive
3849 * authentication. Do nothing.
3851 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
3852 bombout(("Strange packet received during authentication: type %d",
3860 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3861 * we can look at the string in it and know what we can
3862 * helpfully try next.
3864 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
3867 ssh2_pkt_getstring(&methods
, &methlen
);
3868 kbd_inter_running
= FALSE
;
3869 if (!ssh2_pkt_getbool()) {
3871 * We have received an unequivocal Access
3872 * Denied. This can translate to a variety of
3875 * - if we'd just tried "none" authentication,
3876 * it's not worth printing anything at all
3878 * - if we'd just tried a public key _offer_,
3879 * the message should be "Server refused our
3880 * key" (or no message at all if the key
3881 * came from Pageant)
3883 * - if we'd just tried anything else, the
3884 * message really should be "Access denied".
3886 * Additionally, if we'd just tried password
3887 * authentication, we should break out of this
3888 * whole loop so as to go back to the username
3891 if (type
== AUTH_TYPE_NONE
) {
3893 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
3894 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
3895 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
3896 c_write_str("Server refused our key\r\n");
3897 logevent("Server refused public key");
3898 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
3899 /* server declined keyboard-interactive; ignore */
3901 c_write_str("Access denied\r\n");
3902 logevent("Access denied");
3903 if (type
== AUTH_TYPE_PASSWORD
) {
3909 c_write_str("Further authentication required\r\n");
3910 logevent("Further authentication required");
3914 in_commasep_string("publickey", methods
, methlen
);
3916 in_commasep_string("password", methods
, methlen
);
3917 can_keyb_inter
= cfg
.try_ki_auth
&&
3918 in_commasep_string("keyboard-interactive", methods
, methlen
);
3923 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
3925 * Attempt public-key authentication using Pageant.
3927 static unsigned char request
[5], *response
, *p
;
3928 static int responselen
;
3929 static int i
, nkeys
;
3930 static int authed
= FALSE
;
3935 logevent("Pageant is running. Requesting keys.");
3937 /* Request the keys held by the agent. */
3938 PUT_32BIT(request
, 1);
3939 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
3940 agent_query(request
, 5, &r
, &responselen
);
3941 response
= (unsigned char *) r
;
3942 if (response
&& responselen
>= 5 &&
3943 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
3945 nkeys
= GET_32BIT(p
);
3949 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
3952 for (i
= 0; i
< nkeys
; i
++) {
3953 static char *pkblob
, *alg
, *commentp
;
3954 static int pklen
, alglen
, commentlen
;
3955 static int siglen
, retlen
, len
;
3956 static char *q
, *agentreq
, *ret
;
3961 sprintf(buf
, "Trying Pageant key #%d", i
);
3964 pklen
= GET_32BIT(p
);
3968 alglen
= GET_32BIT(pkblob
);
3970 commentlen
= GET_32BIT(p
);
3974 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3975 ssh2_pkt_addstring(username
);
3976 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3977 ssh2_pkt_addstring("publickey"); /* method */
3978 ssh2_pkt_addbool(FALSE
); /* no signature included */
3979 ssh2_pkt_addstring_start();
3980 ssh2_pkt_addstring_data(alg
, alglen
);
3981 ssh2_pkt_addstring_start();
3982 ssh2_pkt_addstring_data(pkblob
, pklen
);
3985 crWaitUntilV(ispkt
);
3986 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
3987 logevent("Key refused");
3991 if (flags
& FLAG_VERBOSE
) {
3993 ("Authenticating with public key \"");
3994 c_write(commentp
, commentlen
);
3995 c_write_str("\" from agent\r\n");
3999 * Server is willing to accept the key.
4000 * Construct a SIGN_REQUEST.
4002 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4003 ssh2_pkt_addstring(username
);
4004 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4005 ssh2_pkt_addstring("publickey"); /* method */
4006 ssh2_pkt_addbool(TRUE
);
4007 ssh2_pkt_addstring_start();
4008 ssh2_pkt_addstring_data(alg
, alglen
);
4009 ssh2_pkt_addstring_start();
4010 ssh2_pkt_addstring_data(pkblob
, pklen
);
4012 siglen
= pktout
.length
- 5 + 4 + 20;
4013 len
= 1; /* message type */
4014 len
+= 4 + pklen
; /* key blob */
4015 len
+= 4 + siglen
; /* data to sign */
4016 len
+= 4; /* flags */
4017 agentreq
= smalloc(4 + len
);
4018 PUT_32BIT(agentreq
, len
);
4020 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4021 PUT_32BIT(q
, pklen
);
4023 memcpy(q
, pkblob
, pklen
);
4025 PUT_32BIT(q
, siglen
);
4027 /* Now the data to be signed... */
4030 memcpy(q
, ssh2_session_id
, 20);
4032 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4033 q
+= pktout
.length
- 5;
4034 /* And finally the (zero) flags word. */
4036 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4040 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4041 logevent("Sending Pageant's response");
4042 ssh2_pkt_addstring_start();
4043 ssh2_pkt_addstring_data(ret
+ 9,
4051 ("Pageant failed to answer challenge");
4061 if (!method
&& can_pubkey
&& *cfg
.keyfile
4062 && !tried_pubkey_config
) {
4063 unsigned char *pub_blob
;
4064 char *algorithm
, *comment
;
4067 tried_pubkey_config
= TRUE
;
4070 * Try the public key supplied in the configuration.
4072 * First, offer the public blob to see if the server is
4073 * willing to accept it.
4075 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4078 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4079 ssh2_pkt_addstring(username
);
4080 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4081 ssh2_pkt_addstring("publickey"); /* method */
4082 ssh2_pkt_addbool(FALSE
); /* no signature included */
4083 ssh2_pkt_addstring(algorithm
);
4084 ssh2_pkt_addstring_start();
4085 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4087 logevent("Offered public key"); /* FIXME */
4089 crWaitUntilV(ispkt
);
4090 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4092 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4093 continue; /* key refused; give up on it */
4096 logevent("Offer of public key accepted");
4098 * Actually attempt a serious authentication using
4101 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4103 "Passphrase for key \"%.100s\": ",
4109 c_write_str("Authenticating with public key \"");
4110 c_write_str(comment
);
4111 c_write_str("\"\r\n");
4112 method
= AUTH_PUBLICKEY_FILE
;
4116 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4117 method
= AUTH_KEYBOARD_INTERACTIVE
;
4118 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4119 tried_keyb_inter
= TRUE
;
4121 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4122 ssh2_pkt_addstring(username
);
4123 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4124 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4125 ssh2_pkt_addstring(""); /* lang */
4126 ssh2_pkt_addstring("");
4129 crWaitUntilV(ispkt
);
4130 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4131 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4133 logevent("Keyboard-interactive authentication refused");
4134 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4138 kbd_inter_running
= TRUE
;
4141 if (kbd_inter_running
) {
4142 method
= AUTH_KEYBOARD_INTERACTIVE
;
4143 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4144 tried_keyb_inter
= TRUE
;
4146 /* We've got packet with that "interactive" info
4147 dump banners, and set its prompt as ours */
4149 char *name
, *inst
, *lang
, *prompt
;
4150 int name_len
, inst_len
, lang_len
, prompt_len
;
4151 ssh2_pkt_getstring(&name
, &name_len
);
4152 ssh2_pkt_getstring(&inst
, &inst_len
);
4153 ssh2_pkt_getstring(&lang
, &lang_len
);
4155 c_write_untrusted(name
, name_len
);
4157 c_write_untrusted(inst
, inst_len
);
4158 num_prompts
= ssh2_pkt_getuint32();
4160 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4161 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4162 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4163 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4166 echo
= ssh2_pkt_getbool();
4170 if (!method
&& can_passwd
) {
4171 method
= AUTH_PASSWORD
;
4172 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4179 if (!ssh_get_line(pwprompt
, password
,
4180 sizeof(password
), TRUE
)) {
4182 * get_line failed to get a password (for
4183 * example because one was supplied on the
4184 * command line which has already failed to
4187 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4188 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4190 ("No more passwords available to try");
4191 ssh2_pkt_addstring("en"); /* language tag */
4193 connection_fatal("Unable to authenticate");
4194 ssh_state
= SSH_STATE_CLOSED
;
4201 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4206 crWaitUntilV(!ispkt
);
4208 switch (c
= *in
++) {
4229 if (pos
< sizeof(password
)-1)
4230 password
[pos
++] = c
;
4234 c_write_str("\r\n");
4238 if (method
== AUTH_PUBLICKEY_FILE
) {
4240 * We have our passphrase. Now try the actual authentication.
4242 struct ssh2_userkey
*key
;
4244 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4245 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4246 if (key
== SSH2_WRONG_PASSPHRASE
) {
4247 c_write_str("Wrong passphrase\r\n");
4248 tried_pubkey_config
= FALSE
;
4250 c_write_str("Unable to load private key\r\n");
4251 tried_pubkey_config
= TRUE
;
4253 /* Send a spurious AUTH_NONE to return to the top. */
4254 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4255 ssh2_pkt_addstring(username
);
4256 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4257 ssh2_pkt_addstring("none"); /* method */
4259 type
= AUTH_TYPE_NONE
;
4261 unsigned char *blob
, *sigdata
;
4262 int blob_len
, sigdata_len
;
4265 * We have loaded the private key and the server
4266 * has announced that it's willing to accept it.
4267 * Hallelujah. Generate a signature and send it.
4269 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4270 ssh2_pkt_addstring(username
);
4271 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4272 ssh2_pkt_addstring("publickey"); /* method */
4273 ssh2_pkt_addbool(TRUE
);
4274 ssh2_pkt_addstring(key
->alg
->name
);
4275 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4276 ssh2_pkt_addstring_start();
4277 ssh2_pkt_addstring_data(blob
, blob_len
);
4281 * The data to be signed is:
4285 * followed by everything so far placed in the
4288 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4289 sigdata
= smalloc(sigdata_len
);
4290 PUT_32BIT(sigdata
, 20);
4291 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4292 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4295 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4297 ssh2_pkt_addstring_start();
4298 ssh2_pkt_addstring_data(blob
, blob_len
);
4303 type
= AUTH_TYPE_PUBLICKEY
;
4305 } else if (method
== AUTH_PASSWORD
) {
4307 * We send the password packet lumped tightly together with
4308 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4309 * string long enough to make the total length of the two
4310 * packets constant. This should ensure that a passive
4311 * listener doing traffic analyis can't work out the length
4314 * For this to work, we need an assumption about the
4315 * maximum length of the password packet. I think 256 is
4316 * pretty conservative. Anyone using a password longer than
4317 * that probably doesn't have much to worry about from
4318 * people who find out how long their password is!
4320 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4321 ssh2_pkt_addstring(username
);
4322 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4323 ssh2_pkt_addstring("password");
4324 ssh2_pkt_addbool(FALSE
);
4325 ssh2_pkt_addstring(password
);
4328 * We'll include a string that's an exact multiple of the
4329 * cipher block size. If the cipher is NULL for some
4330 * reason, we don't do this trick at all because we gain
4336 stringlen
= (256 - deferred_len
);
4337 stringlen
+= cscipher
->blksize
- 1;
4338 stringlen
-= (stringlen
% cscipher
->blksize
);
4341 * Temporarily disable actual compression,
4342 * so we can guarantee to get this string
4343 * exactly the length we want it. The
4344 * compression-disabling routine should
4345 * return an integer indicating how many
4346 * bytes we should adjust our string length
4349 stringlen
-= cscomp
->disable_compression();
4351 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4352 ssh2_pkt_addstring_start();
4353 for (i
= 0; i
< stringlen
; i
++) {
4354 char c
= (char) random_byte();
4355 ssh2_pkt_addstring_data(&c
, 1);
4359 ssh_pkt_defersend();
4360 logevent("Sent password");
4361 type
= AUTH_TYPE_PASSWORD
;
4362 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4363 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4364 ssh2_pkt_adduint32(num_prompts
);
4365 ssh2_pkt_addstring(password
);
4366 memset(password
, 0, sizeof(password
));
4368 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4371 ("No supported authentication methods left to try!\r\n");
4373 ("No supported authentications offered. Disconnecting");
4374 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4375 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4377 ("No supported authentication methods available");
4378 ssh2_pkt_addstring("en"); /* language tag */
4380 ssh_state
= SSH_STATE_CLOSED
;
4384 } while (!we_are_in
);
4387 * Now we're authenticated for the connection protocol. The
4388 * connection protocol will automatically have started at this
4389 * point; there's no need to send SERVICE_REQUEST.
4393 * So now create a channel with a session in it.
4395 ssh_channels
= newtree234(ssh_channelcmp
);
4396 mainchan
= smalloc(sizeof(struct ssh_channel
));
4397 mainchan
->localid
= alloc_channel_id();
4398 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4399 ssh2_pkt_addstring("session");
4400 ssh2_pkt_adduint32(mainchan
->localid
);
4401 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4402 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4403 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4405 crWaitUntilV(ispkt
);
4406 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4407 bombout(("Server refused to open a session"));
4409 /* FIXME: error data comes back in FAILURE packet */
4411 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4412 bombout(("Server's channel confirmation cited wrong channel"));
4415 mainchan
->remoteid
= ssh2_pkt_getuint32();
4416 mainchan
->type
= CHAN_MAINSESSION
;
4417 mainchan
->closes
= 0;
4418 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4419 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4420 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4421 add234(ssh_channels
, mainchan
);
4422 logevent("Opened channel for session");
4425 * Potentially enable X11 forwarding.
4427 if (cfg
.x11_forward
) {
4428 char proto
[20], data
[64];
4429 logevent("Requesting X11 forwarding");
4430 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4431 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4432 ssh2_pkt_adduint32(mainchan
->remoteid
);
4433 ssh2_pkt_addstring("x11-req");
4434 ssh2_pkt_addbool(1); /* want reply */
4435 ssh2_pkt_addbool(0); /* many connections */
4436 ssh2_pkt_addstring(proto
);
4437 ssh2_pkt_addstring(data
);
4438 ssh2_pkt_adduint32(0); /* screen number */
4442 crWaitUntilV(ispkt
);
4443 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4444 unsigned i
= ssh2_pkt_getuint32();
4445 struct ssh_channel
*c
;
4446 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4448 continue; /* nonexistent channel */
4449 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4451 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4453 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4454 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4455 bombout(("Unexpected response to X11 forwarding request:"
4456 " packet type %d", pktin
.type
));
4459 logevent("X11 forwarding refused");
4461 logevent("X11 forwarding enabled");
4462 ssh_X11_fwd_enabled
= TRUE
;
4467 * Enable port forwardings.
4470 static char *e
; /* preserve across crReturn */
4474 char sports
[256], dports
[256], host
[256];
4477 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4478 /* Add port forwardings. */
4483 while (*e
&& *e
!= '\t')
4489 while (*e
&& *e
!= ':')
4499 dport
= atoi(dports
);
4500 sport
= atoi(sports
);
4501 if (sport
&& dport
) {
4503 pfd_addforward(host
, dport
, sport
);
4504 sprintf(buf
, "Local port %d forwarding to %s:%d",
4505 sport
, host
, dport
);
4508 struct ssh_rportfwd
*pf
;
4509 pf
= smalloc(sizeof(*pf
));
4510 strcpy(pf
->dhost
, host
);
4513 if (add234(ssh_rportfwds
, pf
) != pf
) {
4515 "Duplicate remote port forwarding to %s:%d",
4520 sprintf(buf
, "Requesting remote port %d (forwarded to %s:%d)",
4521 sport
, host
, dport
);
4523 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4524 ssh2_pkt_addstring("tcpip-forward");
4525 ssh2_pkt_addbool(1);/* want reply */
4526 ssh2_pkt_addstring("127.0.0.1");
4527 ssh2_pkt_adduint32(sport
);
4531 crWaitUntilV(ispkt
);
4532 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4533 unsigned i
= ssh2_pkt_getuint32();
4534 struct ssh_channel
*c
;
4535 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4537 continue;/* nonexistent channel */
4538 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4540 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4542 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4543 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4544 bombout(("Unexpected response to port "
4545 "forwarding request: packet type %d",
4549 logevent("Server refused this port forwarding");
4551 logevent("Remote port forwarding enabled");
4560 * Potentially enable agent forwarding.
4562 if (cfg
.agentfwd
&& agent_exists()) {
4563 logevent("Requesting OpenSSH-style agent forwarding");
4564 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4565 ssh2_pkt_adduint32(mainchan
->remoteid
);
4566 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4567 ssh2_pkt_addbool(1); /* want reply */
4571 crWaitUntilV(ispkt
);
4572 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4573 unsigned i
= ssh2_pkt_getuint32();
4574 struct ssh_channel
*c
;
4575 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4577 continue; /* nonexistent channel */
4578 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4580 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4582 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4583 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4584 bombout(("Unexpected response to agent forwarding request:"
4585 " packet type %d", pktin
.type
));
4588 logevent("Agent forwarding refused");
4590 logevent("Agent forwarding enabled");
4591 ssh_agentfwd_enabled
= TRUE
;
4596 * Now allocate a pty for the session.
4599 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4600 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4601 ssh2_pkt_addstring("pty-req");
4602 ssh2_pkt_addbool(1); /* want reply */
4603 ssh2_pkt_addstring(cfg
.termtype
);
4604 ssh2_pkt_adduint32(cols
);
4605 ssh2_pkt_adduint32(rows
);
4606 ssh2_pkt_adduint32(0); /* pixel width */
4607 ssh2_pkt_adduint32(0); /* pixel height */
4608 ssh2_pkt_addstring_start();
4609 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4611 ssh_state
= SSH_STATE_INTERMED
;
4614 crWaitUntilV(ispkt
);
4615 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4616 unsigned i
= ssh2_pkt_getuint32();
4617 struct ssh_channel
*c
;
4618 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4620 continue; /* nonexistent channel */
4621 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4623 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4625 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4626 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4627 bombout(("Unexpected response to pty request:"
4628 " packet type %d", pktin
.type
));
4631 c_write_str("Server refused to allocate pty\r\n");
4632 ssh_editing
= ssh_echoing
= 1;
4634 logevent("Allocated pty");
4637 ssh_editing
= ssh_echoing
= 1;
4641 * Start a shell or a remote command. We may have to attempt
4642 * this twice if the config data has provided a second choice
4649 if (ssh_fallback_cmd
) {
4650 subsys
= cfg
.ssh_subsys2
;
4651 cmd
= cfg
.remote_cmd_ptr2
;
4653 subsys
= cfg
.ssh_subsys
;
4654 cmd
= cfg
.remote_cmd_ptr
;
4657 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4658 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4660 ssh2_pkt_addstring("subsystem");
4661 ssh2_pkt_addbool(1); /* want reply */
4662 ssh2_pkt_addstring(cmd
);
4664 ssh2_pkt_addstring("exec");
4665 ssh2_pkt_addbool(1); /* want reply */
4666 ssh2_pkt_addstring(cmd
);
4668 ssh2_pkt_addstring("shell");
4669 ssh2_pkt_addbool(1); /* want reply */
4673 crWaitUntilV(ispkt
);
4674 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4675 unsigned i
= ssh2_pkt_getuint32();
4676 struct ssh_channel
*c
;
4677 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4679 continue; /* nonexistent channel */
4680 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4682 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4683 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4684 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4685 bombout(("Unexpected response to shell/command request:"
4686 " packet type %d", pktin
.type
));
4690 * We failed to start the command. If this is the
4691 * fallback command, we really are finished; if it's
4692 * not, and if the fallback command exists, try falling
4693 * back to it before complaining.
4695 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
4696 logevent("Primary command failed; attempting fallback");
4697 ssh_fallback_cmd
= TRUE
;
4700 bombout(("Server refused to start a shell/command"));
4703 logevent("Started a shell/command");
4708 ssh_state
= SSH_STATE_SESSION
;
4712 ssh_special(TS_EOF
);
4717 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
4720 static int try_send
;
4724 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
4725 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
4728 unsigned i
= ssh2_pkt_getuint32();
4729 struct ssh_channel
*c
;
4730 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4732 continue; /* nonexistent channel */
4733 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
4734 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
4735 continue; /* extended but not stderr */
4736 ssh2_pkt_getstring(&data
, &length
);
4739 c
->v
.v2
.locwindow
-= length
;
4741 case CHAN_MAINSESSION
:
4743 from_backend(pktin
.type
==
4744 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
4748 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
4751 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
4754 while (length
> 0) {
4755 if (c
->u
.a
.lensofar
< 4) {
4756 int l
= min(4 - c
->u
.a
.lensofar
, length
);
4757 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
4761 c
->u
.a
.lensofar
+= l
;
4763 if (c
->u
.a
.lensofar
== 4) {
4765 4 + GET_32BIT(c
->u
.a
.msglen
);
4766 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
4767 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
4769 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
4771 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
4773 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
4777 c
->u
.a
.lensofar
+= l
;
4779 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
4780 void *reply
, *sentreply
;
4782 agent_query(c
->u
.a
.message
,
4783 c
->u
.a
.totallen
, &reply
,
4788 /* Fake SSH_AGENT_FAILURE. */
4789 sentreply
= "\0\0\0\1\5";
4792 ssh2_add_channel_data(c
, sentreply
,
4797 sfree(c
->u
.a
.message
);
4798 c
->u
.a
.lensofar
= 0;
4805 * If we are not buffering too much data,
4806 * enlarge the window again at the remote side.
4808 if (bufsize
< OUR_V2_WINSIZE
)
4809 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
4811 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
4812 ssh_state
= SSH_STATE_CLOSED
;
4813 logevent("Received disconnect message");
4815 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
4816 unsigned i
= ssh2_pkt_getuint32();
4817 struct ssh_channel
*c
;
4819 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4821 continue; /* nonexistent channel */
4823 if (c
->type
== CHAN_X11
) {
4825 * Remote EOF on an X11 channel means we should
4826 * wrap up and close the channel ourselves.
4828 x11_close(c
->u
.x11
.s
);
4830 } else if (c
->type
== CHAN_AGENT
) {
4832 } else if (c
->type
== CHAN_SOCKDATA
) {
4833 pfd_close(c
->u
.pfd
.s
);
4836 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
4837 unsigned i
= ssh2_pkt_getuint32();
4838 struct ssh_channel
*c
;
4840 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4842 continue; /* nonexistent channel */
4843 /* Do pre-close processing on the channel. */
4845 case CHAN_MAINSESSION
:
4846 break; /* nothing to see here, move along */
4848 if (c
->u
.x11
.s
!= NULL
)
4849 x11_close(c
->u
.x11
.s
);
4856 if (c
->u
.pfd
.s
!= NULL
)
4857 pfd_close(c
->u
.pfd
.s
);
4861 if (c
->closes
== 0) {
4862 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4863 ssh2_pkt_adduint32(c
->remoteid
);
4866 del234(ssh_channels
, c
);
4867 bufchain_clear(&c
->v
.v2
.outbuffer
);
4871 * See if that was the last channel left open.
4873 if (count234(ssh_channels
) == 0) {
4876 * We used to send SSH_MSG_DISCONNECT here,
4877 * because I'd believed that _every_ conforming
4878 * SSH2 connection had to end with a disconnect
4879 * being sent by at least one side; apparently
4880 * I was wrong and it's perfectly OK to
4881 * unceremoniously slam the connection shut
4882 * when you're done, and indeed OpenSSH feels
4883 * this is more polite than sending a
4884 * DISCONNECT. So now we don't.
4886 logevent("All channels closed. Disconnecting");
4887 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4888 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4889 ssh2_pkt_addstring("All open channels closed");
4890 ssh2_pkt_addstring("en"); /* language tag */
4893 ssh_state
= SSH_STATE_CLOSED
;
4896 continue; /* remote sends close; ignore (FIXME) */
4897 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4898 unsigned i
= ssh2_pkt_getuint32();
4899 struct ssh_channel
*c
;
4900 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4902 continue; /* nonexistent channel */
4903 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4905 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4906 unsigned i
= ssh2_pkt_getuint32();
4907 struct ssh_channel
*c
;
4908 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4910 continue; /* nonexistent channel */
4911 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4912 continue; /* dunno why they're confirming this */
4913 c
->remoteid
= ssh2_pkt_getuint32();
4914 c
->type
= CHAN_SOCKDATA
;
4915 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4916 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4917 bufchain_init(&c
->v
.v2
.outbuffer
);
4919 pfd_confirm(c
->u
.pfd
.s
);
4922 * We have a pending close on this channel,
4923 * which we decided on before the server acked
4924 * the channel open. So now we know the
4925 * remoteid, we can close it again.
4927 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4928 ssh2_pkt_adduint32(c
->remoteid
);
4931 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
4932 unsigned i
= ssh2_pkt_getuint32();
4933 struct ssh_channel
*c
;
4934 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4936 continue; /* nonexistent channel */
4937 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4938 continue; /* dunno why they're failing this */
4940 logevent("Forwarded connection refused by server");
4942 pfd_close(c
->u
.pfd
.s
);
4944 del234(ssh_channels
, c
);
4946 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
4949 int typelen
, want_reply
;
4950 struct ssh_channel
*c
;
4952 localid
= ssh2_pkt_getuint32();
4953 ssh2_pkt_getstring(&type
, &typelen
);
4954 want_reply
= ssh2_pkt_getbool();
4957 * First, check that the channel exists. Otherwise,
4958 * we can instantly disconnect with a rude message.
4960 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
4963 sprintf(buf
, "Received channel request for nonexistent"
4964 " channel %d", localid
);
4966 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4967 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4968 ssh2_pkt_addstring(buf
);
4969 ssh2_pkt_addstring("en"); /* language tag */
4971 connection_fatal(buf
);
4972 ssh_state
= SSH_STATE_CLOSED
;
4977 * We don't recognise any form of channel request,
4978 * so we now either ignore the request or respond
4979 * with CHANNEL_FAILURE, depending on want_reply.
4982 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
4983 ssh2_pkt_adduint32(c
->remoteid
);
4986 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
4990 struct ssh_channel
*c
;
4991 unsigned remid
, winsize
, pktsize
;
4992 ssh2_pkt_getstring(&type
, &typelen
);
4993 c
= smalloc(sizeof(struct ssh_channel
));
4995 remid
= ssh2_pkt_getuint32();
4996 winsize
= ssh2_pkt_getuint32();
4997 pktsize
= ssh2_pkt_getuint32();
4999 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
5000 if (!ssh_X11_fwd_enabled
)
5001 error
= "X11 forwarding is not enabled";
5002 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
5004 error
= "Unable to open an X11 connection";
5008 } else if (typelen
== 15 &&
5009 !memcmp(type
, "forwarded-tcpip", 15)) {
5010 struct ssh_rportfwd pf
, *realpf
;
5013 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
5014 pf
.sport
= ssh2_pkt_getuint32();
5015 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
5016 if (realpf
== NULL
) {
5017 error
= "Remote port is not recognised";
5019 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5022 sprintf(buf
, "Received remote port open request for %s:%d",
5023 realpf
->dhost
, realpf
->dport
);
5026 sprintf(buf
, "Port open failed: %s", e
);
5028 error
= "Port open failed";
5030 logevent("Forwarded port opened successfully");
5031 c
->type
= CHAN_SOCKDATA
;
5034 } else if (typelen
== 22 &&
5035 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5036 if (!ssh_agentfwd_enabled
)
5037 error
= "Agent forwarding is not enabled";
5039 c
->type
= CHAN_AGENT
; /* identify channel type */
5040 c
->u
.a
.lensofar
= 0;
5043 error
= "Unsupported channel type requested";
5046 c
->remoteid
= remid
;
5048 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5049 ssh2_pkt_adduint32(c
->remoteid
);
5050 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5051 ssh2_pkt_addstring(error
);
5052 ssh2_pkt_addstring("en"); /* language tag */
5056 c
->localid
= alloc_channel_id();
5058 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5059 c
->v
.v2
.remwindow
= winsize
;
5060 c
->v
.v2
.remmaxpkt
= pktsize
;
5061 bufchain_init(&c
->v
.v2
.outbuffer
);
5062 add234(ssh_channels
, c
);
5063 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5064 ssh2_pkt_adduint32(c
->remoteid
);
5065 ssh2_pkt_adduint32(c
->localid
);
5066 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5067 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5071 bombout(("Strange packet received: type %d", pktin
.type
));
5076 * We have spare data. Add it to the channel buffer.
5078 ssh2_add_channel_data(mainchan
, in
, inlen
);
5083 struct ssh_channel
*c
;
5085 * Try to send data on all channels if we can.
5087 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5088 int bufsize
= ssh2_try_send(c
);
5091 case CHAN_MAINSESSION
:
5092 /* stdin need not receive an unthrottle
5093 * notification since it will be polled */
5096 x11_unthrottle(c
->u
.x11
.s
);
5099 /* agent sockets are request/response and need no
5100 * buffer management */
5103 pfd_unthrottle(c
->u
.pfd
.s
);
5115 * Handle the top-level SSH2 protocol.
5117 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5119 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5121 do_ssh2_authconn(in
, inlen
, ispkt
);
5125 * Called to set up the connection.
5127 * Returns an error message, or NULL on success.
5129 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5134 if (crypto_startup() == 0)
5135 return "Microsoft high encryption pack not installed!";
5141 ssh1_throttle_count
= 0;
5142 ssh_overall_bufsize
= 0;
5143 ssh_fallback_cmd
= 0;
5145 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5153 * Called to send data down the Telnet connection.
5155 static int ssh_send(char *buf
, int len
)
5157 if (s
== NULL
|| ssh_protocol
== NULL
)
5160 ssh_protocol(buf
, len
, 0);
5162 return ssh_sendbuffer();
5166 * Called to query the current amount of buffered stdin data.
5168 static int ssh_sendbuffer(void)
5172 if (s
== NULL
|| ssh_protocol
== NULL
)
5176 * If the SSH socket itself has backed up, add the total backup
5177 * size on that to any individual buffer on the stdin channel.
5180 if (ssh_throttled_all
)
5181 override_value
= ssh_overall_bufsize
;
5183 if (ssh_version
== 1) {
5184 return override_value
;
5185 } else if (ssh_version
== 2) {
5186 if (!mainchan
|| mainchan
->closes
> 0)
5187 return override_value
;
5189 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5196 * Called to set the size of the window from SSH's POV.
5198 static void ssh_size(void)
5200 switch (ssh_state
) {
5201 case SSH_STATE_BEFORE_SIZE
:
5202 case SSH_STATE_PREPACKET
:
5203 case SSH_STATE_CLOSED
:
5204 break; /* do nothing */
5205 case SSH_STATE_INTERMED
:
5206 size_needed
= TRUE
; /* buffer for later */
5208 case SSH_STATE_SESSION
:
5210 if (ssh_version
== 1) {
5211 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5212 PKT_INT
, rows
, PKT_INT
, cols
,
5213 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5215 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5216 ssh2_pkt_adduint32(mainchan
->remoteid
);
5217 ssh2_pkt_addstring("window-change");
5218 ssh2_pkt_addbool(0);
5219 ssh2_pkt_adduint32(cols
);
5220 ssh2_pkt_adduint32(rows
);
5221 ssh2_pkt_adduint32(0);
5222 ssh2_pkt_adduint32(0);
5231 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5232 * can send an EOF and collect resulting output (e.g. `plink
5235 static void ssh_special(Telnet_Special code
)
5237 if (code
== TS_EOF
) {
5238 if (ssh_state
!= SSH_STATE_SESSION
) {
5240 * Buffer the EOF in case we are pre-SESSION, so we can
5241 * send it as soon as we reach SESSION.
5247 if (ssh_version
== 1) {
5248 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5250 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5251 ssh2_pkt_adduint32(mainchan
->remoteid
);
5254 logevent("Sent EOF message");
5255 } else if (code
== TS_PING
) {
5256 if (ssh_state
== SSH_STATE_CLOSED
5257 || ssh_state
== SSH_STATE_PREPACKET
) return;
5258 if (ssh_version
== 1) {
5259 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5261 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5262 ssh2_pkt_addstring_start();
5270 void *new_sock_channel(Socket s
)
5272 struct ssh_channel
*c
;
5273 c
= smalloc(sizeof(struct ssh_channel
));
5276 c
->remoteid
= -1; /* to be set when open confirmed */
5277 c
->localid
= alloc_channel_id();
5279 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5281 add234(ssh_channels
, c
);
5287 * This is called when stdout/stderr (the entity to which
5288 * from_backend sends data) manages to clear some backlog.
5290 void ssh_unthrottle(int bufsize
)
5292 if (ssh_version
== 1) {
5293 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5294 ssh1_stdout_throttling
= 0;
5298 if (mainchan
&& mainchan
->closes
== 0)
5299 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5303 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5305 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5308 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5311 if (ssh_version
== 1) {
5312 send_packet(SSH1_MSG_PORT_OPEN
,
5313 PKT_INT
, c
->localid
,
5316 //PKT_STR, <org:orgport>,
5319 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5320 ssh2_pkt_addstring("direct-tcpip");
5321 ssh2_pkt_adduint32(c
->localid
);
5322 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5323 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5324 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5325 ssh2_pkt_addstring(hostname
);
5326 ssh2_pkt_adduint32(port
);
5328 * We make up values for the originator data; partly it's
5329 * too much hassle to keep track, and partly I'm not
5330 * convinced the server should be told details like that
5331 * about my local network configuration.
5333 ssh2_pkt_addstring("client-side-connection");
5334 ssh2_pkt_adduint32(0);
5340 static Socket
ssh_socket(void)
5345 static int ssh_sendok(void)
5350 static int ssh_ldisc(int option
)
5352 if (option
== LD_ECHO
)
5354 if (option
== LD_EDIT
)
5359 Backend ssh_backend
= {