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
241 const static struct ssh2_ciphers
*ciphers
[] = {
248 const static struct ssh_kex
*kex_algs
[] = {
249 &ssh_diffiehellman_gex
,
253 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
255 static void nullmac_key(unsigned char *key
)
258 static void nullmac_generate(unsigned char *blk
, int len
,
262 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
)
266 const static struct ssh_mac ssh_mac_none
= {
267 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
269 const static struct ssh_mac
*macs
[] = {
270 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
272 const static struct ssh_mac
*buggymacs
[] = {
273 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
276 static void ssh_comp_none_init(void)
279 static int ssh_comp_none_block(unsigned char *block
, int len
,
280 unsigned char **outblock
, int *outlen
)
284 static int ssh_comp_none_disable(void)
288 const static struct ssh_compress ssh_comp_none
= {
290 ssh_comp_none_init
, ssh_comp_none_block
,
291 ssh_comp_none_init
, ssh_comp_none_block
,
292 ssh_comp_none_disable
294 extern const struct ssh_compress ssh_zlib
;
295 const static struct ssh_compress
*compressions
[] = {
296 &ssh_zlib
, &ssh_comp_none
299 enum { /* channel types */
304 CHAN_SOCKDATA_DORMANT
/* one the remote hasn't confirmed */
308 * 2-3-4 tree storing channels.
311 unsigned remoteid
, localid
;
315 struct ssh1_data_channel
{
318 struct ssh2_data_channel
{
320 unsigned remwindow
, remmaxpkt
;
325 struct ssh_agent_channel
{
326 unsigned char *message
;
327 unsigned char msglen
[4];
328 int lensofar
, totallen
;
330 struct ssh_x11_channel
{
333 struct ssh_pfd_channel
{
340 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
341 * 2 use this structure in different ways, reflecting SSH 2's
342 * altogether saner approach to port forwarding.
344 * In SSH 1, you arrange a remote forwarding by sending the server
345 * the remote port number, and the local destination host:port.
346 * When a connection comes in, the server sends you back that
347 * host:port pair, and you connect to it. This is a ready-made
348 * security hole if you're not on the ball: a malicious server
349 * could send you back _any_ host:port pair, so if you trustingly
350 * connect to the address it gives you then you've just opened the
351 * entire inside of your corporate network just by connecting
352 * through it to a dodgy SSH server. Hence, we must store a list of
353 * host:port pairs we _are_ trying to forward to, and reject a
354 * connection request from the server if it's not in the list.
356 * In SSH 2, each side of the connection minds its own business and
357 * doesn't send unnecessary information to the other. You arrange a
358 * remote forwarding by sending the server just the remote port
359 * number. When a connection comes in, the server tells you which
360 * of its ports was connected to; and _you_ have to remember what
361 * local host:port pair went with that port number.
363 * Hence: in SSH 1 this structure stores host:port pairs we intend
364 * to allow connections to, and is indexed by those host:port
365 * pairs. In SSH 2 it stores a mapping from source port to
366 * destination host:port pair, and is indexed by source port.
368 struct ssh_rportfwd
{
369 unsigned sport
, dport
;
382 static SHA_State exhash
, exhashbase
;
384 static Socket s
= NULL
;
386 static unsigned char session_key
[32];
387 static int ssh1_compressing
;
388 static int ssh1_remote_protoflags
;
389 static int ssh1_local_protoflags
;
390 static int ssh_agentfwd_enabled
;
391 static int ssh_X11_fwd_enabled
;
392 static int ssh_remote_bugs
;
393 static const struct ssh_cipher
*cipher
= NULL
;
394 static const struct ssh2_cipher
*cscipher
= NULL
;
395 static const struct ssh2_cipher
*sccipher
= NULL
;
396 static const struct ssh_mac
*csmac
= NULL
;
397 static const struct ssh_mac
*scmac
= NULL
;
398 static const struct ssh_compress
*cscomp
= NULL
;
399 static const struct ssh_compress
*sccomp
= NULL
;
400 static const struct ssh_kex
*kex
= NULL
;
401 static const struct ssh_signkey
*hostkey
= NULL
;
402 static unsigned char ssh2_session_id
[20];
403 int (*ssh_get_line
) (const char *prompt
, char *str
, int maxlen
,
406 static char *savedhost
;
407 static int savedport
;
408 static int ssh_send_ok
;
409 static int ssh_echoing
, ssh_editing
;
411 static tree234
*ssh_channels
; /* indexed by local id */
412 static struct ssh_channel
*mainchan
; /* primary session channel */
414 static tree234
*ssh_rportfwds
;
418 SSH_STATE_BEFORE_SIZE
,
422 } ssh_state
= SSH_STATE_PREPACKET
;
424 static int size_needed
= FALSE
, eof_needed
= FALSE
;
426 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
427 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
428 static unsigned char *deferred_send_data
= NULL
;
429 static int deferred_len
= 0, deferred_size
= 0;
432 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
433 * that fails. This variable is the means by which scp.c can reach
434 * into the SSH code and find out which one it got.
436 int ssh_fallback_cmd
= 0;
438 static int ssh_version
;
439 static int ssh1_throttle_count
;
440 static int ssh_overall_bufsize
;
441 static int ssh_throttled_all
;
442 static int ssh1_stdout_throttling
;
443 static void (*ssh_protocol
) (unsigned char *in
, int inlen
, int ispkt
);
444 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
445 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
446 static void ssh_size(void);
447 static void ssh_special(Telnet_Special
);
448 static int ssh2_try_send(struct ssh_channel
*c
);
449 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
451 static void ssh_throttle_all(int enable
, int bufsize
);
452 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
);
453 static int (*s_rdpkt
) (unsigned char **data
, int *datalen
);
454 static int ssh_sendbuffer(void);
456 static struct rdpkt1_state_tag
{
457 long len
, pad
, biglen
, to_read
;
458 unsigned long realcrc
, gotcrc
;
464 static struct rdpkt2_state_tag
{
465 long len
, pad
, payload
, packetlen
, maclen
;
468 unsigned long incoming_sequence
;
471 static int ssh_channelcmp(void *av
, void *bv
)
473 struct ssh_channel
*a
= (struct ssh_channel
*) av
;
474 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
475 if (a
->localid
< b
->localid
)
477 if (a
->localid
> b
->localid
)
481 static int ssh_channelfind(void *av
, void *bv
)
483 unsigned *a
= (unsigned *) av
;
484 struct ssh_channel
*b
= (struct ssh_channel
*) bv
;
492 static int ssh_rportcmp_ssh1(void *av
, void *bv
)
494 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
495 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
497 if ( (i
= strcmp(a
->dhost
, b
->dhost
)) != 0)
498 return i
< 0 ?
-1 : +1;
499 if (a
->dport
> b
->dport
)
501 if (a
->dport
< b
->dport
)
506 static int ssh_rportcmp_ssh2(void *av
, void *bv
)
508 struct ssh_rportfwd
*a
= (struct ssh_rportfwd
*) av
;
509 struct ssh_rportfwd
*b
= (struct ssh_rportfwd
*) bv
;
511 if (a
->sport
> b
->sport
)
513 if (a
->sport
< b
->sport
)
518 static int alloc_channel_id(void)
520 const unsigned CHANNEL_NUMBER_OFFSET
= 256;
521 unsigned low
, high
, mid
;
523 struct ssh_channel
*c
;
526 * First-fit allocation of channel numbers: always pick the
527 * lowest unused one. To do this, binary-search using the
528 * counted B-tree to find the largest channel ID which is in a
529 * contiguous sequence from the beginning. (Precisely
530 * everything in that sequence must have ID equal to its tree
531 * index plus CHANNEL_NUMBER_OFFSET.)
533 tsize
= count234(ssh_channels
);
537 while (high
- low
> 1) {
538 mid
= (high
+ low
) / 2;
539 c
= index234(ssh_channels
, mid
);
540 if (c
->localid
== mid
+ CHANNEL_NUMBER_OFFSET
)
541 low
= mid
; /* this one is fine */
543 high
= mid
; /* this one is past it */
546 * Now low points to either -1, or the tree index of the
547 * largest ID in the initial sequence.
550 unsigned i
= low
+ 1 + CHANNEL_NUMBER_OFFSET
;
551 assert(NULL
== find234(ssh_channels
, &i
, ssh_channelfind
));
553 return low
+ 1 + CHANNEL_NUMBER_OFFSET
;
556 static void c_write(char *buf
, int len
)
558 if ((flags
& FLAG_STDERR
)) {
560 for (i
= 0; i
< len
; i
++)
562 fputc(buf
[i
], stderr
);
565 from_backend(1, buf
, len
);
568 static void c_write_untrusted(char *buf
, int len
)
571 for (i
= 0; i
< len
; i
++) {
574 else if ((buf
[i
] & 0x60) || (buf
[i
] == '\r'))
579 static void c_write_str(char *buf
)
581 c_write(buf
, strlen(buf
));
585 * Collect incoming data in the incoming packet buffer.
586 * Decipher and verify the packet when it is completely read.
587 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
588 * Update the *data and *datalen variables.
589 * Return the additional nr of bytes needed, or 0 when
590 * a complete packet is available.
592 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
594 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
603 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
604 while ((*datalen
) == 0)
606 st
->len
= (st
->len
<< 8) + **data
;
607 (*data
)++, (*datalen
)--;
610 st
->pad
= 8 - (st
->len
% 8);
611 st
->biglen
= st
->len
+ st
->pad
;
612 pktin
.length
= st
->len
- 5;
614 if (pktin
.maxlen
< st
->biglen
) {
615 pktin
.maxlen
= st
->biglen
;
616 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
617 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
619 fatalbox("Out of memory");
622 st
->to_read
= st
->biglen
;
624 while (st
->to_read
> 0) {
625 st
->chunk
= st
->to_read
;
626 while ((*datalen
) == 0)
627 crReturn(st
->to_read
);
628 if (st
->chunk
> (*datalen
))
629 st
->chunk
= (*datalen
);
630 memcpy(st
->p
, *data
, st
->chunk
);
632 *datalen
-= st
->chunk
;
634 st
->to_read
-= st
->chunk
;
638 cipher
->decrypt(pktin
.data
, st
->biglen
);
640 debug(("Got packet len=%d pad=%d\n", st
->len
, st
->pad
));
641 dmemdump(pktin
.data
, st
->biglen
);
644 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
645 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
646 if (st
->gotcrc
!= st
->realcrc
) {
647 bombout(("Incorrect CRC received on packet"));
651 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
653 if (ssh1_compressing
) {
654 unsigned char *decompblk
;
657 debug(("Packet payload pre-decompression:\n"));
658 dmemdump(pktin
.body
- 1, pktin
.length
+ 1);
660 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
661 &decompblk
, &decomplen
);
663 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
664 pktin
.maxlen
= st
->pad
+ decomplen
;
665 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
666 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
668 fatalbox("Out of memory");
671 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
673 pktin
.length
= decomplen
- 1;
675 debug(("Packet payload post-decompression:\n"));
676 dmemdump(pktin
.body
- 1, pktin
.length
+ 1);
680 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
681 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
682 pktin
.type
== SSH1_MSG_DEBUG
||
683 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
684 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
685 long strlen
= GET_32BIT(pktin
.body
);
686 if (strlen
+ 4 != pktin
.length
) {
687 bombout(("Received data packet with bogus string length"));
692 pktin
.type
= pktin
.body
[-1];
694 if (pktin
.type
== SSH1_MSG_DEBUG
) {
695 /* log debug message */
697 int strlen
= GET_32BIT(pktin
.body
);
698 strcpy(buf
, "Remote: ");
701 memcpy(buf
+ 8, pktin
.body
+ 4, strlen
);
702 buf
[8 + strlen
] = '\0';
705 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
710 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
711 /* log reason code in disconnect message */
713 unsigned msglen
= GET_32BIT(pktin
.body
);
715 strcpy(buf
, "Remote sent disconnect: ");
716 nowlen
= strlen(buf
);
717 if (msglen
> sizeof(buf
) - nowlen
- 1)
718 msglen
= sizeof(buf
) - nowlen
- 1;
719 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
720 buf
[nowlen
+ msglen
] = '\0';
722 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
729 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
731 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
739 st
->cipherblk
= sccipher
->blksize
;
742 if (st
->cipherblk
< 8)
745 if (pktin
.maxlen
< st
->cipherblk
) {
746 pktin
.maxlen
= st
->cipherblk
;
749 NULL ?
smalloc(st
->cipherblk
+
750 APIEXTRA
) : srealloc(pktin
.data
,
754 fatalbox("Out of memory");
758 * Acquire and decrypt the first block of the packet. This will
759 * contain the length and padding details.
761 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
762 while ((*datalen
) == 0)
763 crReturn(st
->cipherblk
- st
->i
);
764 pktin
.data
[st
->i
] = *(*data
)++;
769 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
772 * Now get the length and padding figures.
774 st
->len
= GET_32BIT(pktin
.data
);
775 st
->pad
= pktin
.data
[4];
778 * This enables us to deduce the payload length.
780 st
->payload
= st
->len
- st
->pad
- 1;
782 pktin
.length
= st
->payload
+ 5;
785 * So now we can work out the total packet length.
787 st
->packetlen
= st
->len
+ 4;
788 st
->maclen
= scmac ? scmac
->len
: 0;
791 * Adjust memory allocation if packet is too big.
793 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
794 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
797 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
802 fatalbox("Out of memory");
806 * Read and decrypt the remainder of the packet.
808 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
810 while ((*datalen
) == 0)
811 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
812 pktin
.data
[st
->i
] = *(*data
)++;
815 /* Decrypt everything _except_ the MAC. */
817 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
818 st
->packetlen
- st
->cipherblk
);
821 debug(("Got packet len=%d pad=%d\n", st
->len
, st
->pad
));
822 dmemdump(pktin
.data
, st
->packetlen
);
829 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
830 st
->incoming_sequence
)) {
831 bombout(("Incorrect MAC received on packet"));
834 st
->incoming_sequence
++; /* whether or not we MACed */
837 * Decompress packet payload.
840 unsigned char *newpayload
;
842 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
843 &newpayload
, &newlen
)) {
844 if (pktin
.maxlen
< newlen
+ 5) {
845 pktin
.maxlen
= newlen
+ 5;
848 NULL ?
smalloc(pktin
.maxlen
+
849 APIEXTRA
) : srealloc(pktin
.data
,
853 fatalbox("Out of memory");
855 pktin
.length
= 5 + newlen
;
856 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
858 debug(("Post-decompression payload:\n"));
859 dmemdump(pktin
.data
+ 5, newlen
);
867 pktin
.type
= pktin
.data
[5];
869 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
870 goto next_packet
; /* FIXME: print DEBUG message */
872 if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
873 /* log reason code in disconnect message */
875 int reason
= GET_32BIT(pktin
.data
+ 6);
876 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
878 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
879 sprintf(buf
, "Received disconnect message (%s)",
880 ssh2_disconnect_reasons
[reason
]);
882 sprintf(buf
, "Received disconnect message (unknown type %d)",
886 strcpy(buf
, "Disconnection message text: ");
887 nowlen
= strlen(buf
);
888 if (msglen
> sizeof(buf
) - nowlen
- 1)
889 msglen
= sizeof(buf
) - nowlen
- 1;
890 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
891 buf
[nowlen
+ msglen
] = '\0';
893 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
895 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
896 ssh2_disconnect_reasons
[reason
] : "unknown",
904 static void ssh1_pktout_size(int len
)
908 len
+= 5; /* type and CRC */
912 pktout
.length
= len
- 5;
913 if (pktout
.maxlen
< biglen
) {
914 pktout
.maxlen
= biglen
;
916 /* Allocate enough buffer space for extra block
917 * for MS CryptEncrypt() */
918 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
919 srealloc(pktout
.data
, biglen
+ 12));
921 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
922 srealloc(pktout
.data
, biglen
+ 4));
925 fatalbox("Out of memory");
927 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
930 static void s_wrpkt_start(int type
, int len
)
932 ssh1_pktout_size(len
);
936 static int s_wrpkt_prepare(void)
938 int pad
, len
, biglen
, i
;
941 pktout
.body
[-1] = pktout
.type
;
943 if (ssh1_compressing
) {
944 unsigned char *compblk
;
947 debug(("Packet payload pre-compression:\n"));
948 dmemdump(pktout
.body
- 1, pktout
.length
+ 1);
950 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
952 ssh1_pktout_size(complen
- 1);
953 memcpy(pktout
.body
- 1, compblk
, complen
);
957 len
= pktout
.length
+ 5; /* type and CRC */
961 for (i
= 0; i
< pad
; i
++)
962 pktout
.data
[i
+ 4] = random_byte();
963 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
964 PUT_32BIT(pktout
.data
+ biglen
, crc
);
965 PUT_32BIT(pktout
.data
, len
);
968 debug(("Sending packet len=%d\n", biglen
+ 4));
969 dmemdump(pktout
.data
, biglen
+ 4);
972 cipher
->encrypt(pktout
.data
+ 4, biglen
);
977 static void s_wrpkt(void)
980 len
= s_wrpkt_prepare();
981 backlog
= sk_write(s
, pktout
.data
, len
);
982 if (backlog
> SSH_MAX_BACKLOG
)
983 ssh_throttle_all(1, backlog
);
986 static void s_wrpkt_defer(void)
989 len
= s_wrpkt_prepare();
990 if (deferred_len
+ len
> deferred_size
) {
991 deferred_size
= deferred_len
+ len
+ 128;
992 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
994 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
999 * Construct a packet with the specified contents.
1001 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1003 unsigned char *p
, *argp
, argchar
;
1004 unsigned long argint
;
1005 int pktlen
, argtype
, arglen
;
1009 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1012 (void) va_arg(ap1
, int);
1016 (void) va_arg(ap1
, char);
1020 (void) va_arg(ap1
, unsigned char *);
1021 arglen
= va_arg(ap1
, int);
1025 argp
= va_arg(ap1
, unsigned char *);
1026 arglen
= strlen(argp
);
1027 pktlen
+= 4 + arglen
;
1030 bn
= va_arg(ap1
, Bignum
);
1031 pktlen
+= ssh1_bignum_length(bn
);
1038 s_wrpkt_start(pkttype
, pktlen
);
1041 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1044 argint
= va_arg(ap2
, int);
1045 PUT_32BIT(p
, argint
);
1049 argchar
= va_arg(ap2
, unsigned char);
1054 argp
= va_arg(ap2
, unsigned char *);
1055 arglen
= va_arg(ap2
, int);
1056 memcpy(p
, argp
, arglen
);
1060 argp
= va_arg(ap2
, unsigned char *);
1061 arglen
= strlen(argp
);
1062 PUT_32BIT(p
, arglen
);
1063 memcpy(p
+ 4, argp
, arglen
);
1067 bn
= va_arg(ap2
, Bignum
);
1068 p
+= ssh1_write_bignum(p
, bn
);
1074 static void send_packet(int pkttype
, ...)
1077 va_start(ap1
, pkttype
);
1078 va_start(ap2
, pkttype
);
1079 construct_packet(pkttype
, ap1
, ap2
);
1083 static void defer_packet(int pkttype
, ...)
1086 va_start(ap1
, pkttype
);
1087 va_start(ap2
, pkttype
);
1088 construct_packet(pkttype
, ap1
, ap2
);
1092 static int ssh_versioncmp(char *a
, char *b
)
1095 unsigned long av
, bv
;
1097 av
= strtoul(a
, &ae
, 10);
1098 bv
= strtoul(b
, &be
, 10);
1100 return (av
< bv ?
-1 : +1);
1105 av
= strtoul(ae
, &ae
, 10);
1106 bv
= strtoul(be
, &be
, 10);
1108 return (av
< bv ?
-1 : +1);
1114 * Utility routines for putting an SSH-protocol `string' and
1115 * `uint32' into a SHA state.
1118 static void sha_string(SHA_State
* s
, void *str
, int len
)
1120 unsigned char lenblk
[4];
1121 PUT_32BIT(lenblk
, len
);
1122 SHA_Bytes(s
, lenblk
, 4);
1123 SHA_Bytes(s
, str
, len
);
1126 static void sha_uint32(SHA_State
* s
, unsigned i
)
1128 unsigned char intblk
[4];
1129 PUT_32BIT(intblk
, i
);
1130 SHA_Bytes(s
, intblk
, 4);
1134 * SSH2 packet construction functions.
1136 static void ssh2_pkt_ensure(int length
)
1138 if (pktout
.maxlen
< length
) {
1139 pktout
.maxlen
= length
+ 256;
1142 NULL ?
smalloc(pktout
.maxlen
+
1143 APIEXTRA
) : srealloc(pktout
.data
,
1147 fatalbox("Out of memory");
1150 static void ssh2_pkt_adddata(void *data
, int len
)
1152 pktout
.length
+= len
;
1153 ssh2_pkt_ensure(pktout
.length
);
1154 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1156 static void ssh2_pkt_addbyte(unsigned char byte
)
1158 ssh2_pkt_adddata(&byte
, 1);
1160 static void ssh2_pkt_init(int pkt_type
)
1163 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1165 static void ssh2_pkt_addbool(unsigned char value
)
1167 ssh2_pkt_adddata(&value
, 1);
1169 static void ssh2_pkt_adduint32(unsigned long value
)
1172 PUT_32BIT(x
, value
);
1173 ssh2_pkt_adddata(x
, 4);
1175 static void ssh2_pkt_addstring_start(void)
1177 ssh2_pkt_adduint32(0);
1178 pktout
.savedpos
= pktout
.length
;
1180 static void ssh2_pkt_addstring_str(char *data
)
1182 ssh2_pkt_adddata(data
, strlen(data
));
1183 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1184 pktout
.length
- pktout
.savedpos
);
1186 static void ssh2_pkt_addstring_data(char *data
, int len
)
1188 ssh2_pkt_adddata(data
, len
);
1189 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1190 pktout
.length
- pktout
.savedpos
);
1192 static void ssh2_pkt_addstring(char *data
)
1194 ssh2_pkt_addstring_start();
1195 ssh2_pkt_addstring_str(data
);
1197 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1200 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1203 fatalbox("out of memory");
1205 for (i
= 1; i
<= n
; i
++)
1206 p
[i
] = bignum_byte(b
, n
- i
);
1208 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1210 memmove(p
, p
+ i
, n
+ 1 - i
);
1214 static void ssh2_pkt_addmp(Bignum b
)
1218 p
= ssh2_mpint_fmt(b
, &len
);
1219 ssh2_pkt_addstring_start();
1220 ssh2_pkt_addstring_data(p
, len
);
1225 * Construct an SSH2 final-form packet: compress it, encrypt it,
1226 * put the MAC on it. Final packet, ready to be sent, is stored in
1227 * pktout.data. Total length is returned.
1229 static int ssh2_pkt_construct(void)
1231 int cipherblk
, maclen
, padding
, i
;
1232 static unsigned long outgoing_sequence
= 0;
1235 * Compress packet payload.
1238 unsigned char *newpayload
;
1241 if (cscomp
&& cscomp
!= &ssh_comp_none
) {
1242 debug(("Pre-compression payload:\n"));
1243 dmemdump(pktout
.data
+ 5, pktout
.length
- 5);
1246 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1247 &newpayload
, &newlen
)) {
1249 ssh2_pkt_adddata(newpayload
, newlen
);
1255 * Add padding. At least four bytes, and must also bring total
1256 * length (minus MAC) up to a multiple of the block size.
1258 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1259 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1262 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1263 maclen
= csmac ? csmac
->len
: 0;
1264 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1265 pktout
.data
[4] = padding
;
1266 for (i
= 0; i
< padding
; i
++)
1267 pktout
.data
[pktout
.length
+ i
] = random_byte();
1268 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1270 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1272 outgoing_sequence
++; /* whether or not we MACed */
1275 debug(("Sending packet len=%d\n", pktout
.length
+ padding
));
1276 dmemdump(pktout
.data
, pktout
.length
+ padding
);
1280 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1282 /* Ready-to-send packet starts at pktout.data. We return length. */
1283 return pktout
.length
+ padding
+ maclen
;
1287 * Construct and send an SSH2 packet immediately.
1289 static void ssh2_pkt_send(void)
1293 len
= ssh2_pkt_construct();
1294 backlog
= sk_write(s
, pktout
.data
, len
);
1295 if (backlog
> SSH_MAX_BACKLOG
)
1296 ssh_throttle_all(1, backlog
);
1300 * Construct an SSH2 packet and add it to a deferred data block.
1301 * Useful for sending multiple packets in a single sk_write() call,
1302 * to prevent a traffic-analysing listener from being able to work
1303 * out the length of any particular packet (such as the password
1306 * Note that because SSH2 sequence-numbers its packets, this can
1307 * NOT be used as an m4-style `defer' allowing packets to be
1308 * constructed in one order and sent in another.
1310 static void ssh2_pkt_defer(void)
1312 int len
= ssh2_pkt_construct();
1313 if (deferred_len
+ len
> deferred_size
) {
1314 deferred_size
= deferred_len
+ len
+ 128;
1315 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1317 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1318 deferred_len
+= len
;
1322 * Send the whole deferred data block constructed by
1323 * ssh2_pkt_defer() or SSH1's defer_packet().
1325 static void ssh_pkt_defersend(void)
1328 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1329 deferred_len
= deferred_size
= 0;
1330 sfree(deferred_send_data
);
1331 deferred_send_data
= NULL
;
1332 if (backlog
> SSH_MAX_BACKLOG
)
1333 ssh_throttle_all(1, backlog
);
1337 void bndebug(char *string
, Bignum b
)
1341 p
= ssh2_mpint_fmt(b
, &len
);
1342 debug(("%s", string
));
1343 for (i
= 0; i
< len
; i
++)
1344 debug((" %02x", p
[i
]));
1350 static void sha_mpint(SHA_State
* s
, Bignum b
)
1354 p
= ssh2_mpint_fmt(b
, &len
);
1355 sha_string(s
, p
, len
);
1360 * SSH2 packet decode functions.
1362 static unsigned long ssh2_pkt_getuint32(void)
1364 unsigned long value
;
1365 if (pktin
.length
- pktin
.savedpos
< 4)
1366 return 0; /* arrgh, no way to decline (FIXME?) */
1367 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1368 pktin
.savedpos
+= 4;
1371 static int ssh2_pkt_getbool(void)
1373 unsigned long value
;
1374 if (pktin
.length
- pktin
.savedpos
< 1)
1375 return 0; /* arrgh, no way to decline (FIXME?) */
1376 value
= pktin
.data
[pktin
.savedpos
] != 0;
1380 static void ssh2_pkt_getstring(char **p
, int *length
)
1383 if (pktin
.length
- pktin
.savedpos
< 4)
1385 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1386 pktin
.savedpos
+= 4;
1387 if (pktin
.length
- pktin
.savedpos
< *length
)
1389 *p
= pktin
.data
+ pktin
.savedpos
;
1390 pktin
.savedpos
+= *length
;
1392 static Bignum
ssh2_pkt_getmp(void)
1398 ssh2_pkt_getstring(&p
, &length
);
1402 bombout(("internal error: Can't handle negative mpints"));
1405 b
= bignum_from_bytes(p
, length
);
1410 * Examine the remote side's version string and compare it against
1411 * a list of known buggy implementations.
1413 static void ssh_detect_bugs(char *vstring
)
1415 char *imp
; /* pointer to implementation part */
1417 imp
+= strcspn(imp
, "-");
1419 imp
+= strcspn(imp
, "-");
1422 ssh_remote_bugs
= 0;
1424 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1425 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1426 !strcmp(imp
, "1.2.22") || !strcmp(imp
, "Cisco-1.25")) {
1428 * These versions don't support SSH1_MSG_IGNORE, so we have
1429 * to use a different defence against password length
1432 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1433 logevent("We believe remote version has SSH1 ignore bug");
1436 if (!strcmp(imp
, "Cisco-1.25")) {
1438 * These versions need a plain password sent; they can't
1439 * handle having a null and a random length of data after
1442 ssh_remote_bugs
|= BUG_NEEDS_SSH1_PLAIN_PASSWORD
;
1443 logevent("We believe remote version needs a plain SSH1 password");
1446 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1447 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1448 !strncmp(imp
, "2.1 ", 4)) {
1450 * These versions have the HMAC bug.
1452 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1453 logevent("We believe remote version has SSH2 HMAC bug");
1457 static int do_ssh_init(unsigned char c
)
1460 static char version
[10];
1461 static char *vstring
;
1462 static int vstrsize
;
1468 /* Search for the string "SSH-" in the input. */
1471 static const int transS
[] = { 1, 2, 2, 1 };
1472 static const int transH
[] = { 0, 0, 3, 0 };
1473 static const int transminus
[] = { 0, 0, 0, -1 };
1484 crReturn(1); /* get another character */
1488 vstring
= smalloc(vstrsize
);
1489 strcpy(vstring
, "SSH-");
1493 crReturn(1); /* get another char */
1494 if (vslen
>= vstrsize
- 1) {
1496 vstring
= srealloc(vstring
, vstrsize
);
1498 vstring
[vslen
++] = c
;
1503 } else if (i
< sizeof(version
) - 1)
1505 } else if (c
== '\n')
1509 ssh_agentfwd_enabled
= FALSE
;
1510 rdpkt2_state
.incoming_sequence
= 0;
1513 vlog
= smalloc(20 + vslen
);
1514 vstring
[strcspn (vstring
, "\r\n")] = '\0'; /* remove end-of-line chars */
1515 sprintf(vlog
, "Server version: %s", vstring
);
1517 ssh_detect_bugs(vstring
);
1521 * Server version "1.99" means we can choose whether we use v1
1522 * or v2 protocol. Choice is based on cfg.sshprot.
1524 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1526 * This is a v2 server. Begin v2 protocol.
1528 char verstring
[80], vlog
[100];
1529 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1530 SHA_Init(&exhashbase
);
1532 * Hash our version string and their version string.
1534 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1535 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1536 sprintf(vlog
, "We claim version: %s", verstring
);
1538 strcat(verstring
, "\n");
1539 logevent("Using SSH protocol version 2");
1540 sk_write(s
, verstring
, strlen(verstring
));
1541 ssh_protocol
= ssh2_protocol
;
1543 s_rdpkt
= ssh2_rdpkt
;
1546 * This is a v1 server. Begin v1 protocol.
1548 char verstring
[80], vlog
[100];
1549 sprintf(verstring
, "SSH-%s-%s",
1550 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1552 sprintf(vlog
, "We claim version: %s", verstring
);
1554 strcat(verstring
, "\n");
1555 logevent("Using SSH protocol version 1");
1556 sk_write(s
, verstring
, strlen(verstring
));
1557 ssh_protocol
= ssh1_protocol
;
1559 s_rdpkt
= ssh1_rdpkt
;
1561 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1568 static void ssh_gotdata(unsigned char *data
, int datalen
)
1573 * To begin with, feed the characters one by one to the
1574 * protocol initialisation / selection function do_ssh_init().
1575 * When that returns 0, we're done with the initial greeting
1576 * exchange and can move on to packet discipline.
1581 crReturnV
; /* more data please */
1582 ret
= do_ssh_init(*data
);
1590 * We emerge from that loop when the initial negotiation is
1591 * over and we have selected an s_rdpkt function. Now pass
1592 * everything to s_rdpkt, and then pass the resulting packets
1593 * to the proper protocol handler.
1598 while (datalen
> 0) {
1599 if (s_rdpkt(&data
, &datalen
) == 0) {
1600 if (ssh_state
== SSH_STATE_CLOSED
) {
1603 ssh_protocol(NULL
, 0, 1);
1604 if (ssh_state
== SSH_STATE_CLOSED
) {
1614 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1617 ssh_state
= SSH_STATE_CLOSED
;
1623 /* A socket error has occurred. */
1624 connection_fatal(error_msg
);
1626 /* Otherwise, the remote side closed the connection normally. */
1631 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1633 ssh_gotdata(data
, len
);
1634 if (ssh_state
== SSH_STATE_CLOSED
) {
1644 static void ssh_sent(Plug plug
, int bufsize
)
1647 * If the send backlog on the SSH socket itself clears, we
1648 * should unthrottle the whole world if it was throttled.
1650 if (bufsize
< SSH_MAX_BACKLOG
)
1651 ssh_throttle_all(0, bufsize
);
1655 * Connect to specified host and port.
1656 * Returns an error message, or NULL on success.
1657 * Also places the canonical host name into `realhost'. It must be
1658 * freed by the caller.
1660 static char *connect_to_host(char *host
, int port
, char **realhost
, int nodelay
)
1662 static struct plug_function_table fn_table
= {
1667 }, *fn_table_ptr
= &fn_table
;
1676 savedhost
= smalloc(1 + strlen(host
));
1678 fatalbox("Out of memory");
1679 strcpy(savedhost
, host
);
1682 port
= 22; /* default ssh port */
1697 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1700 addr
= sk_namelookup(host
, realhost
);
1701 if ((err
= sk_addr_error(addr
)))
1705 *realhost
= strdup(FWhost
);
1712 char buf
[200], addrbuf
[100];
1713 sk_getaddr(addr
, addrbuf
, 100);
1714 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1717 s
= sk_new(addr
, port
, 0, 1, nodelay
, &fn_table_ptr
);
1718 if ((err
= sk_socket_error(s
)))
1722 sk_write(s
, "connect ", 8);
1723 sk_write(s
, FWhost
, strlen(FWhost
));
1726 sprintf(buf
, " %d\n", FWport
);
1727 sk_write(s
, buf
, strlen(buf
));
1735 * Throttle or unthrottle the SSH connection.
1737 static void ssh1_throttle(int adjust
)
1739 int old_count
= ssh1_throttle_count
;
1740 ssh1_throttle_count
+= adjust
;
1741 assert(ssh1_throttle_count
>= 0);
1742 if (ssh1_throttle_count
&& !old_count
) {
1743 sk_set_frozen(s
, 1);
1744 } else if (!ssh1_throttle_count
&& old_count
) {
1745 sk_set_frozen(s
, 0);
1750 * Throttle or unthrottle _all_ local data streams (for when sends
1751 * on the SSH connection itself back up).
1753 static void ssh_throttle_all(int enable
, int bufsize
)
1756 struct ssh_channel
*c
;
1758 if (enable
== ssh_throttled_all
)
1760 ssh_throttled_all
= enable
;
1761 ssh_overall_bufsize
= bufsize
;
1764 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
1766 case CHAN_MAINSESSION
:
1768 * This is treated separately, outside the switch.
1772 x11_override_throttle(c
->u
.x11
.s
, enable
);
1775 /* Agent channels require no buffer management. */
1778 pfd_override_throttle(c
->u
.x11
.s
, enable
);
1785 * Handle the key exchange and user authentication phases.
1787 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1791 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
1792 unsigned char cookie
[8];
1793 struct RSAKey servkey
, hostkey
;
1794 struct MD5Context md5c
;
1795 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1796 static int tried_publickey
;
1797 static int tis_auth_refused
, ccard_auth_refused
;
1798 static unsigned char session_id
[16];
1799 static int cipher_type
;
1800 static char username
[100];
1807 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1808 bombout(("Public key packet not received"));
1812 logevent("Received public keys");
1814 memcpy(cookie
, pktin
.body
, 8);
1816 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1817 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
1820 * Log the host key fingerprint.
1824 logevent("Host key fingerprint is:");
1825 strcpy(logmsg
, " ");
1826 hostkey
.comment
= NULL
;
1827 rsa_fingerprint(logmsg
+ strlen(logmsg
),
1828 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
1832 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
1833 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
1834 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
1836 ssh1_local_protoflags
=
1837 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1838 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1841 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1842 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1843 MD5Update(&md5c
, pktin
.body
, 8);
1844 MD5Final(session_id
, &md5c
);
1846 for (i
= 0; i
< 32; i
++)
1847 session_key
[i
] = random_byte();
1849 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1851 rsabuf
= smalloc(len
);
1853 fatalbox("Out of memory");
1856 * Verify the host key.
1860 * First format the key into a string.
1862 int len
= rsastr_len(&hostkey
);
1863 char fingerprint
[100];
1864 char *keystr
= smalloc(len
);
1866 fatalbox("Out of memory");
1867 rsastr_fmt(keystr
, &hostkey
);
1868 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1869 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
1874 for (i
= 0; i
< 32; i
++) {
1875 rsabuf
[i
] = session_key
[i
];
1877 rsabuf
[i
] ^= session_id
[i
];
1880 if (hostkey
.bytes
> servkey
.bytes
) {
1881 rsaencrypt(rsabuf
, 32, &servkey
);
1882 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1884 rsaencrypt(rsabuf
, 32, &hostkey
);
1885 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1888 logevent("Encrypted session key");
1891 int cipher_chosen
= 0, warn
= 0;
1892 char *cipher_string
= NULL
;
1893 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
1894 int next_cipher
= cfg
.ssh_cipherlist
[i
];
1895 if (next_cipher
== CIPHER_WARN
) {
1896 /* If/when we choose a cipher, warn about it */
1898 } else if (next_cipher
== CIPHER_AES
) {
1899 /* XXX Probably don't need to mention this. */
1900 logevent("AES not supported in SSH1, skipping");
1902 switch (next_cipher
) {
1903 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
1904 cipher_string
= "3DES"; break;
1905 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
1906 cipher_string
= "Blowfish"; break;
1907 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
1908 cipher_string
= "single-DES"; break;
1910 if (supported_ciphers_mask
& (1 << cipher_type
))
1914 if (!cipher_chosen
) {
1915 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
1916 bombout(("Server violates SSH 1 protocol by not "
1917 "supporting 3DES encryption"));
1919 /* shouldn't happen */
1920 bombout(("No supported ciphers found"));
1924 /* Warn about chosen cipher if necessary. */
1926 askcipher(cipher_string
, 0);
1929 switch (cipher_type
) {
1930 case SSH_CIPHER_3DES
:
1931 logevent("Using 3DES encryption");
1933 case SSH_CIPHER_DES
:
1934 logevent("Using single-DES encryption");
1936 case SSH_CIPHER_BLOWFISH
:
1937 logevent("Using Blowfish encryption");
1941 send_packet(SSH1_CMSG_SESSION_KEY
,
1942 PKT_CHAR
, cipher_type
,
1943 PKT_DATA
, cookie
, 8,
1944 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
1945 PKT_DATA
, rsabuf
, len
,
1946 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
1948 logevent("Trying to enable encryption...");
1952 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1953 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
1954 cipher
->sesskey(session_key
);
1958 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1959 bombout(("Encryption not successfully enabled"));
1963 logevent("Successfully started encryption");
1969 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1971 if (!ssh_get_line("login as: ",
1972 username
, sizeof(username
), FALSE
)) {
1974 * get_line failed to get a username.
1977 logevent("No username provided. Abandoning session.");
1978 ssh_state
= SSH_STATE_CLOSED
;
1982 c_write_str("login as: ");
1985 crWaitUntil(!ispkt
);
1987 switch (c
= *in
++) {
1996 c_write_str("\b \b");
2003 c_write_str("\b \b");
2013 if (((c
>= ' ' && c
<= '~') ||
2014 ((unsigned char) c
>= 160))
2015 && pos
< sizeof(username
)-1) {
2016 username
[pos
++] = c
;
2022 c_write_str("\r\n");
2023 username
[strcspn(username
, "\n\r")] = '\0';
2026 strncpy(username
, cfg
.username
, 99);
2027 username
[99] = '\0';
2030 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2032 char userlog
[22 + sizeof(username
)];
2033 sprintf(userlog
, "Sent username \"%s\"", username
);
2035 if (flags
& FLAG_INTERACTIVE
&&
2036 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2037 strcat(userlog
, "\r\n");
2038 c_write_str(userlog
);
2045 tried_publickey
= 0;
2046 tis_auth_refused
= ccard_auth_refused
= 0;
2048 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2049 static char password
[100];
2050 static char prompt
[200];
2053 static int pwpkt_type
;
2054 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2056 if (agent_exists()) {
2058 * Attempt RSA authentication using Pageant.
2060 static unsigned char request
[5], *response
, *p
;
2061 static int responselen
;
2062 static int i
, nkeys
;
2063 static int authed
= FALSE
;
2066 logevent("Pageant is running. Requesting keys.");
2068 /* Request the keys held by the agent. */
2069 PUT_32BIT(request
, 1);
2070 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2071 agent_query(request
, 5, &r
, &responselen
);
2072 response
= (unsigned char *) r
;
2073 if (response
&& responselen
>= 5 &&
2074 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2076 nkeys
= GET_32BIT(p
);
2080 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2083 for (i
= 0; i
< nkeys
; i
++) {
2084 static struct RSAKey key
;
2085 static Bignum challenge
;
2086 static char *commentp
;
2087 static int commentlen
;
2091 sprintf(buf
, "Trying Pageant key #%d", i
);
2095 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2096 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2097 commentlen
= GET_32BIT(p
);
2101 send_packet(SSH1_CMSG_AUTH_RSA
,
2102 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2104 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2105 logevent("Key refused");
2108 logevent("Received RSA challenge");
2109 ssh1_read_bignum(pktin
.body
, &challenge
);
2111 char *agentreq
, *q
, *ret
;
2114 len
= 1 + 4; /* message type, bit count */
2115 len
+= ssh1_bignum_length(key
.exponent
);
2116 len
+= ssh1_bignum_length(key
.modulus
);
2117 len
+= ssh1_bignum_length(challenge
);
2118 len
+= 16; /* session id */
2119 len
+= 4; /* response format */
2120 agentreq
= smalloc(4 + len
);
2121 PUT_32BIT(agentreq
, len
);
2123 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2124 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2126 q
+= ssh1_write_bignum(q
, key
.exponent
);
2127 q
+= ssh1_write_bignum(q
, key
.modulus
);
2128 q
+= ssh1_write_bignum(q
, challenge
);
2129 memcpy(q
, session_id
, 16);
2131 PUT_32BIT(q
, 1); /* response format */
2132 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2136 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2137 logevent("Sending Pageant's response");
2138 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2139 PKT_DATA
, ret
+ 5, 16,
2143 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2145 ("Pageant's response accepted");
2146 if (flags
& FLAG_VERBOSE
) {
2148 ("Authenticated using RSA key \"");
2149 c_write(commentp
, commentlen
);
2150 c_write_str("\" from agent\r\n");
2155 ("Pageant's response not accepted");
2158 ("Pageant failed to answer challenge");
2162 logevent("No reply received from Pageant");
2165 freebn(key
.exponent
);
2166 freebn(key
.modulus
);
2175 if (*cfg
.keyfile
&& !tried_publickey
)
2176 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2178 if (cfg
.try_tis_auth
&&
2179 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2180 !tis_auth_refused
) {
2181 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2182 logevent("Requested TIS authentication");
2183 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2185 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2186 logevent("TIS authentication declined");
2187 if (flags
& FLAG_INTERACTIVE
)
2188 c_write_str("TIS authentication refused.\r\n");
2189 tis_auth_refused
= 1;
2192 int challengelen
= ((pktin
.body
[0] << 24) |
2193 (pktin
.body
[1] << 16) |
2194 (pktin
.body
[2] << 8) |
2196 logevent("Received TIS challenge");
2197 if (challengelen
> sizeof(prompt
) - 1)
2198 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2199 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2200 /* Prompt heuristic comes from OpenSSH */
2201 strncpy(prompt
+ challengelen
,
2202 memchr(prompt
, '\n', challengelen
) ?
2203 "": "\r\nResponse: ",
2204 (sizeof prompt
) - challengelen
);
2205 prompt
[(sizeof prompt
) - 1] = '\0';
2208 if (cfg
.try_tis_auth
&&
2209 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2210 !ccard_auth_refused
) {
2211 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2212 logevent("Requested CryptoCard authentication");
2213 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2215 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2216 logevent("CryptoCard authentication declined");
2217 c_write_str("CryptoCard authentication refused.\r\n");
2218 ccard_auth_refused
= 1;
2221 int challengelen
= ((pktin
.body
[0] << 24) |
2222 (pktin
.body
[1] << 16) |
2223 (pktin
.body
[2] << 8) |
2225 logevent("Received CryptoCard challenge");
2226 if (challengelen
> sizeof(prompt
) - 1)
2227 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2228 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2229 strncpy(prompt
+ challengelen
,
2230 memchr(prompt
, '\n', challengelen
) ?
2231 "" : "\r\nResponse: ",
2232 sizeof(prompt
) - challengelen
);
2233 prompt
[sizeof(prompt
) - 1] = '\0';
2236 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2237 sprintf(prompt
, "%.90s@%.90s's password: ",
2238 username
, savedhost
);
2240 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2241 char *comment
= NULL
;
2242 if (flags
& FLAG_VERBOSE
)
2243 c_write_str("Trying public key authentication.\r\n");
2244 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2245 if (flags
& FLAG_VERBOSE
)
2246 c_write_str("No passphrase required.\r\n");
2249 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2254 * Show password prompt, having first obtained it via a TIS
2255 * or CryptoCard exchange if we're doing TIS or CryptoCard
2259 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2261 * get_line failed to get a password (for example
2262 * because one was supplied on the command line
2263 * which has already failed to work). Terminate.
2265 send_packet(SSH1_MSG_DISCONNECT
,
2266 PKT_STR
, "No more passwords available to try",
2268 connection_fatal("Unable to authenticate");
2269 ssh_state
= SSH_STATE_CLOSED
;
2273 /* Prompt may have come from server. We've munged it a bit, so
2274 * we know it to be zero-terminated at least once. */
2275 c_write_untrusted(prompt
, strlen(prompt
));
2279 crWaitUntil(!ispkt
);
2281 switch (c
= *in
++) {
2302 if (pos
< sizeof(password
)-1)
2303 password
[pos
++] = c
;
2307 c_write_str("\r\n");
2311 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2313 * Try public key authentication with the specified
2316 static struct RSAKey pubkey
;
2317 static Bignum challenge
, response
;
2319 static unsigned char buffer
[32];
2321 tried_publickey
= 1;
2322 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2324 c_write_str("Couldn't load private key from ");
2325 c_write_str(cfg
.keyfile
);
2326 c_write_str(".\r\n");
2327 continue; /* go and try password */
2330 c_write_str("Wrong passphrase.\r\n");
2331 tried_publickey
= 0;
2332 continue; /* try again */
2336 * Send a public key attempt.
2338 send_packet(SSH1_CMSG_AUTH_RSA
,
2339 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2342 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2343 c_write_str("Server refused our public key.\r\n");
2344 continue; /* go and try password */
2346 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2347 bombout(("Bizarre response to offer of public key"));
2350 ssh1_read_bignum(pktin
.body
, &challenge
);
2351 response
= rsadecrypt(challenge
, &pubkey
);
2352 freebn(pubkey
.private_exponent
); /* burn the evidence */
2354 for (i
= 0; i
< 32; i
++) {
2355 buffer
[i
] = bignum_byte(response
, 31 - i
);
2359 MD5Update(&md5c
, buffer
, 32);
2360 MD5Update(&md5c
, session_id
, 16);
2361 MD5Final(buffer
, &md5c
);
2363 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2364 PKT_DATA
, buffer
, 16, PKT_END
);
2367 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2368 if (flags
& FLAG_VERBOSE
)
2370 ("Failed to authenticate with our public key.\r\n");
2371 continue; /* go and try password */
2372 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2374 ("Bizarre response to RSA authentication response"));
2378 break; /* we're through! */
2380 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2382 * Defence against traffic analysis: we send a
2383 * whole bunch of packets containing strings of
2384 * different lengths. One of these strings is the
2385 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2386 * The others are all random data in
2387 * SSH1_MSG_IGNORE packets. This way a passive
2388 * listener can't tell which is the password, and
2389 * hence can't deduce the password length.
2391 * Anybody with a password length greater than 16
2392 * bytes is going to have enough entropy in their
2393 * password that a listener won't find it _that_
2394 * much help to know how long it is. So what we'll
2397 * - if password length < 16, we send 15 packets
2398 * containing string lengths 1 through 15
2400 * - otherwise, we let N be the nearest multiple
2401 * of 8 below the password length, and send 8
2402 * packets containing string lengths N through
2403 * N+7. This won't obscure the order of
2404 * magnitude of the password length, but it will
2405 * introduce a bit of extra uncertainty.
2407 * A few servers (the old 1.2.18 through 1.2.22)
2408 * can't deal with SSH1_MSG_IGNORE. For these
2409 * servers, we need an alternative defence. We make
2410 * use of the fact that the password is interpreted
2411 * as a C string: so we can append a NUL, then some
2414 * One server (a Cisco one) can deal with neither
2415 * SSH1_MSG_IGNORE _nor_ a padded password string.
2416 * For this server we are left with no defences
2417 * against password length sniffing.
2419 if (!(ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
)) {
2421 * The server can deal with SSH1_MSG_IGNORE, so
2422 * we can use the primary defence.
2424 int bottom
, top
, pwlen
, i
;
2427 pwlen
= strlen(password
);
2429 bottom
= 0; /* zero length passwords are OK! :-) */
2432 bottom
= pwlen
& ~7;
2436 assert(pwlen
>= bottom
&& pwlen
<= top
);
2438 randomstr
= smalloc(top
+ 1);
2440 for (i
= bottom
; i
<= top
; i
++) {
2442 defer_packet(pwpkt_type
, PKT_STR
, password
,
2445 for (j
= 0; j
< i
; j
++) {
2447 randomstr
[j
] = random_byte();
2448 } while (randomstr
[j
] == '\0');
2450 randomstr
[i
] = '\0';
2451 defer_packet(SSH1_MSG_IGNORE
,
2452 PKT_STR
, randomstr
, PKT_END
);
2455 logevent("Sending password with camouflage packets");
2456 ssh_pkt_defersend();
2458 else if (!(ssh_remote_bugs
& BUG_NEEDS_SSH1_PLAIN_PASSWORD
)) {
2460 * The server can't deal with SSH1_MSG_IGNORE
2461 * but can deal with padded passwords, so we
2462 * can use the secondary defence.
2468 len
= strlen(password
);
2469 if (len
< sizeof(string
)) {
2471 strcpy(string
, password
);
2472 len
++; /* cover the zero byte */
2473 while (len
< sizeof(string
)) {
2474 string
[len
++] = (char) random_byte();
2479 logevent("Sending length-padded password");
2480 send_packet(pwpkt_type
, PKT_INT
, len
,
2481 PKT_DATA
, s
, len
, PKT_END
);
2484 * The server has _both_
2485 * BUG_CHOKES_ON_SSH1_IGNORE and
2486 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2487 * therefore nothing we can do.
2490 len
= strlen(password
);
2491 logevent("Sending unpadded password");
2492 send_packet(pwpkt_type
, PKT_INT
, len
,
2493 PKT_DATA
, password
, len
, PKT_END
);
2496 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2499 logevent("Sent password");
2500 memset(password
, 0, strlen(password
));
2502 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2503 if (flags
& FLAG_VERBOSE
)
2504 c_write_str("Access denied\r\n");
2505 logevent("Authentication refused");
2506 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2507 logevent("Received disconnect request");
2508 ssh_state
= SSH_STATE_CLOSED
;
2510 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2511 bombout(("Strange packet received, type %d", pktin
.type
));
2516 logevent("Authentication successful");
2521 void sshfwd_close(struct ssh_channel
*c
)
2523 if (c
&& !c
->closes
) {
2525 * If the channel's remoteid is -1, we have sent
2526 * CHANNEL_OPEN for this channel, but it hasn't even been
2527 * acknowledged by the server. So we must set a close flag
2528 * on it now, and then when the server acks the channel
2529 * open, we can close it then.
2531 if (c
->remoteid
!= -1) {
2532 if (ssh_version
== 1) {
2533 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2536 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2537 ssh2_pkt_adduint32(c
->remoteid
);
2542 if (c
->type
== CHAN_X11
) {
2544 logevent("Forwarded X11 connection terminated");
2545 } else if (c
->type
== CHAN_SOCKDATA
||
2546 c
->type
== CHAN_SOCKDATA_DORMANT
) {
2548 logevent("Forwarded port closed");
2553 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2555 if (ssh_version
== 1) {
2556 send_packet(SSH1_MSG_CHANNEL_DATA
,
2557 PKT_INT
, c
->remoteid
,
2558 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2560 * In SSH1 we can return 0 here - implying that forwarded
2561 * connections are never individually throttled - because
2562 * the only circumstance that can cause throttling will be
2563 * the whole SSH connection backing up, in which case
2564 * _everything_ will be throttled as a whole.
2568 ssh2_add_channel_data(c
, buf
, len
);
2569 return ssh2_try_send(c
);
2573 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2575 if (ssh_version
== 1) {
2576 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2577 c
->v
.v1
.throttling
= 0;
2581 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2585 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2591 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2594 if (ssh_state
== SSH_STATE_CLOSED
)
2597 if (cfg
.agentfwd
&& agent_exists()) {
2598 logevent("Requesting agent forwarding");
2599 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2603 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2604 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2605 bombout(("Protocol confusion"));
2607 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2608 logevent("Agent forwarding refused");
2610 logevent("Agent forwarding enabled");
2611 ssh_agentfwd_enabled
= TRUE
;
2615 if (cfg
.x11_forward
) {
2616 char proto
[20], data
[64];
2617 logevent("Requesting X11 forwarding");
2618 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2619 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2620 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2621 PKT_STR
, proto
, PKT_STR
, data
,
2622 PKT_INT
, 0, PKT_END
);
2624 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2625 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2630 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2631 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2632 bombout(("Protocol confusion"));
2634 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2635 logevent("X11 forwarding refused");
2637 logevent("X11 forwarding enabled");
2638 ssh_X11_fwd_enabled
= TRUE
;
2646 char sports
[256], dports
[256], host
[256];
2649 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2650 /* Add port forwardings. */
2655 while (*e
&& *e
!= '\t')
2661 while (*e
&& *e
!= ':')
2671 dport
= atoi(dports
);
2672 sport
= atoi(sports
);
2673 if (sport
&& dport
) {
2675 pfd_addforward(host
, dport
, sport
);
2676 sprintf(buf
, "Local port %d forwarding to %s:%d",
2677 sport
, host
, dport
);
2680 struct ssh_rportfwd
*pf
;
2681 pf
= smalloc(sizeof(*pf
));
2682 strcpy(pf
->dhost
, host
);
2684 if (add234(ssh_rportfwds
, pf
) != pf
) {
2686 "Duplicate remote port forwarding to %s:%d",
2691 sprintf(buf
, "Requesting remote port %d forward to %s:%d",
2692 sport
, host
, dport
);
2694 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2706 send_packet(SSH1_CMSG_REQUEST_PTY
,
2707 PKT_STR
, cfg
.termtype
,
2708 PKT_INT
, rows
, PKT_INT
, cols
,
2709 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2710 ssh_state
= SSH_STATE_INTERMED
;
2714 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2715 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2716 bombout(("Protocol confusion"));
2718 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2719 c_write_str("Server refused to allocate pty\r\n");
2720 ssh_editing
= ssh_echoing
= 1;
2722 logevent("Allocated pty");
2724 ssh_editing
= ssh_echoing
= 1;
2727 if (cfg
.compression
) {
2728 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2732 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2733 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2734 bombout(("Protocol confusion"));
2736 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2737 c_write_str("Server refused to compress\r\n");
2739 logevent("Started compression");
2740 ssh1_compressing
= TRUE
;
2741 zlib_compress_init();
2742 zlib_decompress_init();
2746 * Start the shell or command.
2748 * Special case: if the first-choice command is an SSH2
2749 * subsystem (hence not usable here) and the second choice
2750 * exists, we fall straight back to that.
2753 char *cmd
= cfg
.remote_cmd_ptr
;
2755 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
2756 cmd
= cfg
.remote_cmd_ptr2
;
2757 ssh_fallback_cmd
= TRUE
;
2760 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2762 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2763 logevent("Started session");
2766 ssh_state
= SSH_STATE_SESSION
;
2770 ssh_special(TS_EOF
);
2772 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
2774 ssh_channels
= newtree234(ssh_channelcmp
);
2778 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2779 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2780 long len
= GET_32BIT(pktin
.body
);
2782 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2783 pktin
.body
+ 4, len
);
2784 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2785 ssh1_stdout_throttling
= 1;
2788 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2789 ssh_state
= SSH_STATE_CLOSED
;
2790 logevent("Received disconnect request");
2792 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2793 /* Remote side is trying to open a channel to talk to our
2794 * X-Server. Give them back a local channel number. */
2795 struct ssh_channel
*c
;
2797 logevent("Received X11 connect request");
2798 /* Refuse if X11 forwarding is disabled. */
2799 if (!ssh_X11_fwd_enabled
) {
2800 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2801 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2802 logevent("Rejected X11 connect request");
2804 c
= smalloc(sizeof(struct ssh_channel
));
2806 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2807 logevent("opening X11 forward connection failed");
2809 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2810 PKT_INT
, GET_32BIT(pktin
.body
),
2814 ("opening X11 forward connection succeeded");
2815 c
->remoteid
= GET_32BIT(pktin
.body
);
2816 c
->localid
= alloc_channel_id();
2818 c
->v
.v1
.throttling
= 0;
2819 c
->type
= CHAN_X11
; /* identify channel type */
2820 add234(ssh_channels
, c
);
2821 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2822 PKT_INT
, c
->remoteid
, PKT_INT
,
2823 c
->localid
, PKT_END
);
2824 logevent("Opened X11 forward channel");
2827 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2828 /* Remote side is trying to open a channel to talk to our
2829 * agent. Give them back a local channel number. */
2830 struct ssh_channel
*c
;
2832 /* Refuse if agent forwarding is disabled. */
2833 if (!ssh_agentfwd_enabled
) {
2834 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2835 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2837 c
= smalloc(sizeof(struct ssh_channel
));
2838 c
->remoteid
= GET_32BIT(pktin
.body
);
2839 c
->localid
= alloc_channel_id();
2841 c
->v
.v1
.throttling
= 0;
2842 c
->type
= CHAN_AGENT
; /* identify channel type */
2843 c
->u
.a
.lensofar
= 0;
2844 add234(ssh_channels
, c
);
2845 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2846 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2849 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
2850 /* Remote side is trying to open a channel to talk to a
2851 * forwarded port. Give them back a local channel number. */
2852 struct ssh_channel
*c
;
2853 struct ssh_rportfwd pf
;
2855 char host
[256], buf
[1024];
2857 c
= smalloc(sizeof(struct ssh_channel
));
2859 hostsize
= GET_32BIT(pktin
.body
+4);
2860 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
2861 if (h
+1 < host
+sizeof(host
))
2866 port
= GET_32BIT(p
);
2868 strcpy(pf
.dhost
, host
);
2871 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
2872 sprintf(buf
, "Rejected remote port open request for %s:%d",
2875 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2876 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2878 sprintf(buf
, "Received remote port open request for %s:%d",
2881 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
2884 sprintf(buf
, "Port open failed: %s", e
);
2887 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2888 PKT_INT
, GET_32BIT(pktin
.body
),
2891 c
->remoteid
= GET_32BIT(pktin
.body
);
2892 c
->localid
= alloc_channel_id();
2894 c
->v
.v1
.throttling
= 0;
2895 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
2896 add234(ssh_channels
, c
);
2897 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2898 PKT_INT
, c
->remoteid
, PKT_INT
,
2899 c
->localid
, PKT_END
);
2900 logevent("Forwarded port opened successfully");
2904 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2905 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2906 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2907 struct ssh_channel
*c
;
2909 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2910 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2911 c
->remoteid
= localid
;
2912 c
->type
= CHAN_SOCKDATA
;
2913 c
->v
.v1
.throttling
= 0;
2914 pfd_confirm(c
->u
.pfd
.s
);
2917 if (c
&& c
->closes
) {
2919 * We have a pending close on this channel,
2920 * which we decided on before the server acked
2921 * the channel open. So now we know the
2922 * remoteid, we can close it again.
2924 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2928 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
2929 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2930 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2931 struct ssh_channel
*c
;
2933 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2934 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2935 logevent("Forwarded connection refused by server");
2936 pfd_close(c
->u
.pfd
.s
);
2937 del234(ssh_channels
, c
);
2941 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
2942 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
2943 /* Remote side closes a channel. */
2944 unsigned i
= GET_32BIT(pktin
.body
);
2945 struct ssh_channel
*c
;
2946 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2950 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
2951 if (!(c
->closes
& closetype
))
2952 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
2954 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
2955 logevent("Forwarded X11 connection terminated");
2956 assert(c
->u
.x11
.s
!= NULL
);
2957 x11_close(c
->u
.x11
.s
);
2960 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
2961 logevent("Forwarded port closed");
2962 assert(c
->u
.pfd
.s
!= NULL
);
2963 pfd_close(c
->u
.pfd
.s
);
2966 c
->closes
|= closetype
;
2967 if (c
->closes
== 3) {
2968 del234(ssh_channels
, c
);
2972 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
2973 /* Data sent down one of our channels. */
2974 int i
= GET_32BIT(pktin
.body
);
2975 int len
= GET_32BIT(pktin
.body
+ 4);
2976 unsigned char *p
= pktin
.body
+ 8;
2977 struct ssh_channel
*c
;
2978 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2983 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
2986 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
2989 /* Data for an agent message. Buffer it. */
2991 if (c
->u
.a
.lensofar
< 4) {
2992 int l
= min(4 - c
->u
.a
.lensofar
, len
);
2993 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
2997 c
->u
.a
.lensofar
+= l
;
2999 if (c
->u
.a
.lensofar
== 4) {
3001 4 + GET_32BIT(c
->u
.a
.msglen
);
3002 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3003 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3005 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
3007 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3009 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
3013 c
->u
.a
.lensofar
+= l
;
3015 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3016 void *reply
, *sentreply
;
3018 agent_query(c
->u
.a
.message
,
3019 c
->u
.a
.totallen
, &reply
,
3024 /* Fake SSH_AGENT_FAILURE. */
3025 sentreply
= "\0\0\0\1\5";
3028 send_packet(SSH1_MSG_CHANNEL_DATA
,
3029 PKT_INT
, c
->remoteid
,
3031 PKT_DATA
, sentreply
, replylen
,
3035 sfree(c
->u
.a
.message
);
3036 c
->u
.a
.lensofar
= 0;
3039 bufsize
= 0; /* agent channels never back up */
3042 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
3043 c
->v
.v1
.throttling
= 1;
3047 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3048 /* may be from EXEC_SHELL on some servers */
3049 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3050 /* may be from EXEC_SHELL on some servers
3051 * if no pty is available or in other odd cases. Ignore */
3052 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3053 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3055 * In case `helpful' firewalls or proxies tack
3056 * extra human-readable text on the end of the
3057 * session which we might mistake for another
3058 * encrypted packet, we close the session once
3059 * we've sent EXIT_CONFIRMATION.
3061 ssh_state
= SSH_STATE_CLOSED
;
3064 bombout(("Strange packet received: type %d", pktin
.type
));
3069 int len
= min(inlen
, 512);
3070 send_packet(SSH1_CMSG_STDIN_DATA
,
3071 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3082 * Utility routine for decoding comma-separated strings in KEXINIT.
3084 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3086 int needlen
= strlen(needle
);
3089 * Is it at the start of the string?
3091 if (haylen
>= needlen
&& /* haystack is long enough */
3092 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3093 (haylen
== needlen
|| haystack
[needlen
] == ',')
3094 /* either , or EOS follows */
3098 * If not, search for the next comma and resume after that.
3099 * If no comma found, terminate.
3101 while (haylen
> 0 && *haystack
!= ',')
3102 haylen
--, haystack
++;
3105 haylen
--, haystack
++; /* skip over comma itself */
3110 * SSH2 key creation method.
3112 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3116 /* First 20 bytes. */
3119 SHA_Bytes(&s
, H
, 20);
3120 SHA_Bytes(&s
, &chr
, 1);
3121 SHA_Bytes(&s
, sessid
, 20);
3122 SHA_Final(&s
, keyspace
);
3123 /* Next 20 bytes. */
3126 SHA_Bytes(&s
, H
, 20);
3127 SHA_Bytes(&s
, keyspace
, 20);
3128 SHA_Final(&s
, keyspace
+ 20);
3132 * Handle the SSH2 transport layer.
3134 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3136 static int i
, j
, len
, nbits
, pbits
, warn
;
3138 static Bignum p
, g
, e
, f
, K
;
3139 static int kex_init_value
, kex_reply_value
;
3140 static const struct ssh_mac
**maclist
;
3142 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3143 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3144 static const struct ssh_mac
*csmac_tobe
= NULL
;
3145 static const struct ssh_mac
*scmac_tobe
= NULL
;
3146 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3147 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3148 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3149 static int hostkeylen
, siglen
;
3150 static void *hkey
; /* actual host key */
3151 static unsigned char exchange_hash
[20];
3152 static unsigned char keyspace
[40];
3153 static int n_preferred_ciphers
;
3154 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3155 static const struct ssh_compress
*preferred_comp
;
3156 static int first_kex
;
3163 * Set up the preferred ciphers. (NULL => warn below here)
3165 n_preferred_ciphers
= 0;
3166 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3167 switch (cfg
.ssh_cipherlist
[i
]) {
3168 case CIPHER_BLOWFISH
:
3169 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3170 n_preferred_ciphers
++;
3173 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_des
;
3174 n_preferred_ciphers
++;
3177 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3178 n_preferred_ciphers
++;
3181 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3182 n_preferred_ciphers
++;
3185 /* Flag for later. Don't bother if it's the last in
3187 if (i
< CIPHER_MAX
- 1) {
3188 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3189 n_preferred_ciphers
++;
3196 * Set up preferred compression.
3198 if (cfg
.compression
)
3199 preferred_comp
= &ssh_zlib
;
3201 preferred_comp
= &ssh_comp_none
;
3204 * Be prepared to work around the buggy MAC problem.
3206 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3207 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3209 maclist
= macs
, nmacs
= lenof(macs
);
3213 * Construct and send our key exchange packet.
3215 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3216 for (i
= 0; i
< 16; i
++)
3217 ssh2_pkt_addbyte((unsigned char) random_byte());
3218 /* List key exchange algorithms. */
3219 ssh2_pkt_addstring_start();
3220 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3221 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3222 if (i
< lenof(kex_algs
) - 1)
3223 ssh2_pkt_addstring_str(",");
3225 /* List server host key algorithms. */
3226 ssh2_pkt_addstring_start();
3227 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3228 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3229 if (i
< lenof(hostkey_algs
) - 1)
3230 ssh2_pkt_addstring_str(",");
3232 /* List client->server encryption algorithms. */
3233 ssh2_pkt_addstring_start();
3234 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3235 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3236 if (!c
) continue; /* warning flag */
3237 for (j
= 0; j
< c
->nciphers
; j
++) {
3238 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3239 if (i
< n_preferred_ciphers
|| j
< c
->nciphers
- 1)
3240 ssh2_pkt_addstring_str(",");
3243 /* List server->client encryption algorithms. */
3244 ssh2_pkt_addstring_start();
3245 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3246 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3247 if (!c
) continue; /* warning flag */
3248 for (j
= 0; j
< c
->nciphers
; j
++) {
3249 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3250 if (i
< n_preferred_ciphers
|| j
< c
->nciphers
- 1)
3251 ssh2_pkt_addstring_str(",");
3254 /* List client->server MAC algorithms. */
3255 ssh2_pkt_addstring_start();
3256 for (i
= 0; i
< nmacs
; i
++) {
3257 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3259 ssh2_pkt_addstring_str(",");
3261 /* List server->client MAC algorithms. */
3262 ssh2_pkt_addstring_start();
3263 for (i
= 0; i
< nmacs
; i
++) {
3264 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3266 ssh2_pkt_addstring_str(",");
3268 /* List client->server compression algorithms. */
3269 ssh2_pkt_addstring_start();
3270 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3271 const struct ssh_compress
*c
=
3272 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3273 ssh2_pkt_addstring_str(c
->name
);
3274 if (i
< lenof(compressions
))
3275 ssh2_pkt_addstring_str(",");
3277 /* List server->client compression algorithms. */
3278 ssh2_pkt_addstring_start();
3279 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3280 const struct ssh_compress
*c
=
3281 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3282 ssh2_pkt_addstring_str(c
->name
);
3283 if (i
< lenof(compressions
))
3284 ssh2_pkt_addstring_str(",");
3286 /* List client->server languages. Empty list. */
3287 ssh2_pkt_addstring_start();
3288 /* List server->client languages. Empty list. */
3289 ssh2_pkt_addstring_start();
3290 /* First KEX packet does _not_ follow, because we're not that brave. */
3291 ssh2_pkt_addbool(FALSE
);
3293 ssh2_pkt_adduint32(0);
3295 exhash
= exhashbase
;
3296 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3302 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3305 * Now examine the other side's KEXINIT to see what we're up
3308 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3309 bombout(("expected key exchange packet from server"));
3314 cscipher_tobe
= NULL
;
3315 sccipher_tobe
= NULL
;
3320 pktin
.savedpos
+= 16; /* skip garbage cookie */
3321 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3322 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3323 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3328 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3329 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3330 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3331 hostkey
= hostkey_algs
[i
];
3335 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3337 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3338 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3342 for (j
= 0; j
< c
->nciphers
; j
++) {
3343 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3344 cscipher_tobe
= c
->list
[j
];
3349 if (cscipher_tobe
) {
3351 askcipher(cscipher_tobe
->name
, 1);
3355 if (!cscipher_tobe
) {
3356 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str
));
3360 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3362 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3363 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3367 for (j
= 0; j
< c
->nciphers
; j
++) {
3368 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3369 sccipher_tobe
= c
->list
[j
];
3374 if (sccipher_tobe
) {
3376 askcipher(sccipher_tobe
->name
, 2);
3380 if (!sccipher_tobe
) {
3381 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str
));
3385 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3386 for (i
= 0; i
< nmacs
; i
++) {
3387 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3388 csmac_tobe
= maclist
[i
];
3392 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3393 for (i
= 0; i
< nmacs
; i
++) {
3394 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3395 scmac_tobe
= maclist
[i
];
3399 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3400 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3401 const struct ssh_compress
*c
=
3402 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3403 if (in_commasep_string(c
->name
, str
, len
)) {
3408 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3409 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3410 const struct ssh_compress
*c
=
3411 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3412 if (in_commasep_string(c
->name
, str
, len
)) {
3419 * Work out the number of bits of key we will need from the key
3420 * exchange. We start with the maximum key length of either
3426 csbits
= cscipher_tobe
->keylen
;
3427 scbits
= sccipher_tobe
->keylen
;
3428 nbits
= (csbits
> scbits ? csbits
: scbits
);
3430 /* The keys only have 160-bit entropy, since they're based on
3431 * a SHA-1 hash. So cap the key size at 160 bits. */
3436 * If we're doing Diffie-Hellman group exchange, start by
3437 * requesting a group.
3439 if (kex
== &ssh_diffiehellman_gex
) {
3440 logevent("Doing Diffie-Hellman group exchange");
3442 * Work out how big a DH group we will need to allow that
3445 pbits
= 512 << ((nbits
- 1) / 64);
3446 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3447 ssh2_pkt_adduint32(pbits
);
3451 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3452 bombout(("expected key exchange group packet from server"));
3455 p
= ssh2_pkt_getmp();
3456 g
= ssh2_pkt_getmp();
3457 dh_setup_group(p
, g
);
3458 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3459 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3462 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3463 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3466 logevent("Doing Diffie-Hellman key exchange");
3468 * Now generate and send e for Diffie-Hellman.
3470 e
= dh_create_e(nbits
* 2);
3471 ssh2_pkt_init(kex_init_value
);
3476 if (pktin
.type
!= kex_reply_value
) {
3477 bombout(("expected key exchange reply packet from server"));
3480 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3481 f
= ssh2_pkt_getmp();
3482 ssh2_pkt_getstring(&sigdata
, &siglen
);
3486 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3487 if (kex
== &ssh_diffiehellman_gex
) {
3488 sha_uint32(&exhash
, pbits
);
3489 sha_mpint(&exhash
, p
);
3490 sha_mpint(&exhash
, g
);
3492 sha_mpint(&exhash
, e
);
3493 sha_mpint(&exhash
, f
);
3494 sha_mpint(&exhash
, K
);
3495 SHA_Final(&exhash
, exchange_hash
);
3500 debug(("Exchange hash is:\n"));
3501 dmemdump(exchange_hash
, 20);
3504 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3506 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3507 bombout(("Server's host key did not match the signature supplied"));
3512 * Authenticate remote host: verify host key. (We've already
3513 * checked the signature of the exchange hash.)
3515 keystr
= hostkey
->fmtkey(hkey
);
3516 fingerprint
= hostkey
->fingerprint(hkey
);
3517 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3518 keystr
, fingerprint
);
3519 if (first_kex
) { /* don't bother logging this in rekeys */
3520 logevent("Host key fingerprint is:");
3521 logevent(fingerprint
);
3525 hostkey
->freekey(hkey
);
3528 * Send SSH2_MSG_NEWKEYS.
3530 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3534 * Expect SSH2_MSG_NEWKEYS from server.
3537 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3538 bombout(("expected new-keys packet from server"));
3543 * Create and initialise session keys.
3545 cscipher
= cscipher_tobe
;
3546 sccipher
= sccipher_tobe
;
3549 cscomp
= cscomp_tobe
;
3550 sccomp
= sccomp_tobe
;
3551 cscomp
->compress_init();
3552 sccomp
->decompress_init();
3554 * Set IVs after keys. Here we use the exchange hash from the
3555 * _first_ key exchange.
3558 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3559 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3560 cscipher
->setcskey(keyspace
);
3561 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3562 sccipher
->setsckey(keyspace
);
3563 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3564 cscipher
->setcsiv(keyspace
);
3565 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3566 sccipher
->setsciv(keyspace
);
3567 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3568 csmac
->setcskey(keyspace
);
3569 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3570 scmac
->setsckey(keyspace
);
3573 * If this is the first key exchange phase, we must pass the
3574 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3575 * wants to see it but because it will need time to initialise
3576 * itself before it sees an actual packet. In subsequent key
3577 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3578 * it would only confuse the layer above.
3586 * Now we're encrypting. Begin returning 1 to the protocol main
3587 * function so that other things can run on top of the
3588 * transport. If we ever see a KEXINIT, we must go back to the
3591 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3594 logevent("Server initiated key re-exchange");
3595 goto begin_key_exchange
;
3601 * Add data to an SSH2 channel output buffer.
3603 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3606 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3610 * Attempt to send data on an SSH2 channel.
3612 static int ssh2_try_send(struct ssh_channel
*c
)
3614 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3617 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3618 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3619 len
= c
->v
.v2
.remwindow
;
3620 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3621 len
= c
->v
.v2
.remmaxpkt
;
3622 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3623 ssh2_pkt_adduint32(c
->remoteid
);
3624 ssh2_pkt_addstring_start();
3625 ssh2_pkt_addstring_data(data
, len
);
3627 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3628 c
->v
.v2
.remwindow
-= len
;
3632 * After having sent as much data as we can, return the amount
3635 return bufchain_size(&c
->v
.v2
.outbuffer
);
3639 * Potentially enlarge the window on an SSH2 channel.
3641 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3643 if (newwin
> c
->v
.v2
.locwindow
) {
3644 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3645 ssh2_pkt_adduint32(c
->remoteid
);
3646 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3648 c
->v
.v2
.locwindow
= newwin
;
3653 * Handle the SSH2 userauth and connection layers.
3655 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3658 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3660 AUTH_KEYBOARD_INTERACTIVE
3664 AUTH_TYPE_PUBLICKEY
,
3665 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3666 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3668 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3669 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3671 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3672 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3673 static int kbd_inter_running
;
3674 static int we_are_in
;
3675 static int num_prompts
, echo
;
3676 static char username
[100];
3677 static char pwprompt
[200];
3678 static char password
[100];
3683 * Request userauth protocol, and await a response to it.
3685 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3686 ssh2_pkt_addstring("ssh-userauth");
3688 crWaitUntilV(ispkt
);
3689 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3690 bombout(("Server refused user authentication protocol"));
3695 * We repeat this whole loop, including the username prompt,
3696 * until we manage a successful authentication. If the user
3697 * types the wrong _password_, they are sent back to the
3698 * beginning to try another username. (If they specify a
3699 * username in the config, they are never asked, even if they
3700 * do give a wrong password.)
3702 * I think this best serves the needs of
3704 * - the people who have no configuration, no keys, and just
3705 * want to try repeated (username,password) pairs until they
3706 * type both correctly
3708 * - people who have keys and configuration but occasionally
3709 * need to fall back to passwords
3711 * - people with a key held in Pageant, who might not have
3712 * logged in to a particular machine before; so they want to
3713 * type a username, and then _either_ their key will be
3714 * accepted, _or_ they will type a password. If they mistype
3715 * the username they will want to be able to get back and
3726 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
3728 if (!ssh_get_line("login as: ",
3729 username
, sizeof(username
), FALSE
)) {
3731 * get_line failed to get a username.
3734 logevent("No username provided. Abandoning session.");
3735 ssh_state
= SSH_STATE_CLOSED
;
3739 c_write_str("login as: ");
3742 crWaitUntilV(!ispkt
);
3744 switch (c
= *in
++) {
3753 c_write_str("\b \b");
3760 c_write_str("\b \b");
3770 if (((c
>= ' ' && c
<= '~') ||
3771 ((unsigned char) c
>= 160))
3772 && pos
< sizeof(username
)-1) {
3773 username
[pos
++] = c
;
3780 c_write_str("\r\n");
3781 username
[strcspn(username
, "\n\r")] = '\0';
3784 strncpy(username
, cfg
.username
, 99);
3785 username
[99] = '\0';
3786 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3787 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3793 * Send an authentication request using method "none": (a)
3794 * just in case it succeeds, and (b) so that we know what
3795 * authentication methods we can usefully try next.
3797 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3798 ssh2_pkt_addstring(username
);
3799 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3800 ssh2_pkt_addstring("none"); /* method */
3802 type
= AUTH_TYPE_NONE
;
3806 tried_pubkey_config
= FALSE
;
3807 tried_agent
= FALSE
;
3808 tried_keyb_inter
= FALSE
;
3809 kbd_inter_running
= FALSE
;
3813 * Wait for the result of the last authentication request.
3816 crWaitUntilV(ispkt
);
3817 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
3821 * Don't show the banner if we're operating in
3822 * non-verbose non-interactive mode. (It's probably
3823 * a script, which means nobody will read the
3824 * banner _anyway_, and moreover the printing of
3825 * the banner will screw up processing on the
3826 * output of (say) plink.)
3828 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
3829 ssh2_pkt_getstring(&banner
, &size
);
3831 c_write_untrusted(banner
, size
);
3833 crWaitUntilV(ispkt
);
3835 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
3836 logevent("Access granted");
3841 if (kbd_inter_running
&&
3842 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
3844 * This is a further prompt in keyboard-interactive
3845 * authentication. Do nothing.
3847 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
3848 bombout(("Strange packet received during authentication: type %d",
3856 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3857 * we can look at the string in it and know what we can
3858 * helpfully try next.
3860 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
3863 ssh2_pkt_getstring(&methods
, &methlen
);
3864 kbd_inter_running
= FALSE
;
3865 if (!ssh2_pkt_getbool()) {
3867 * We have received an unequivocal Access
3868 * Denied. This can translate to a variety of
3871 * - if we'd just tried "none" authentication,
3872 * it's not worth printing anything at all
3874 * - if we'd just tried a public key _offer_,
3875 * the message should be "Server refused our
3876 * key" (or no message at all if the key
3877 * came from Pageant)
3879 * - if we'd just tried anything else, the
3880 * message really should be "Access denied".
3882 * Additionally, if we'd just tried password
3883 * authentication, we should break out of this
3884 * whole loop so as to go back to the username
3887 if (type
== AUTH_TYPE_NONE
) {
3889 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
3890 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
3891 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
3892 c_write_str("Server refused our key\r\n");
3893 logevent("Server refused public key");
3894 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
3895 /* server declined keyboard-interactive; ignore */
3897 c_write_str("Access denied\r\n");
3898 logevent("Access denied");
3899 if (type
== AUTH_TYPE_PASSWORD
) {
3905 c_write_str("Further authentication required\r\n");
3906 logevent("Further authentication required");
3910 in_commasep_string("publickey", methods
, methlen
);
3912 in_commasep_string("password", methods
, methlen
);
3913 can_keyb_inter
= cfg
.try_ki_auth
&&
3914 in_commasep_string("keyboard-interactive", methods
, methlen
);
3919 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
3921 * Attempt public-key authentication using Pageant.
3923 static unsigned char request
[5], *response
, *p
;
3924 static int responselen
;
3925 static int i
, nkeys
;
3926 static int authed
= FALSE
;
3931 logevent("Pageant is running. Requesting keys.");
3933 /* Request the keys held by the agent. */
3934 PUT_32BIT(request
, 1);
3935 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
3936 agent_query(request
, 5, &r
, &responselen
);
3937 response
= (unsigned char *) r
;
3938 if (response
&& responselen
>= 5 &&
3939 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
3941 nkeys
= GET_32BIT(p
);
3945 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
3948 for (i
= 0; i
< nkeys
; i
++) {
3949 static char *pkblob
, *alg
, *commentp
;
3950 static int pklen
, alglen
, commentlen
;
3951 static int siglen
, retlen
, len
;
3952 static char *q
, *agentreq
, *ret
;
3957 sprintf(buf
, "Trying Pageant key #%d", i
);
3960 pklen
= GET_32BIT(p
);
3964 alglen
= GET_32BIT(pkblob
);
3966 commentlen
= GET_32BIT(p
);
3970 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3971 ssh2_pkt_addstring(username
);
3972 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3973 ssh2_pkt_addstring("publickey"); /* method */
3974 ssh2_pkt_addbool(FALSE
); /* no signature included */
3975 ssh2_pkt_addstring_start();
3976 ssh2_pkt_addstring_data(alg
, alglen
);
3977 ssh2_pkt_addstring_start();
3978 ssh2_pkt_addstring_data(pkblob
, pklen
);
3981 crWaitUntilV(ispkt
);
3982 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
3983 logevent("Key refused");
3987 if (flags
& FLAG_VERBOSE
) {
3989 ("Authenticating with public key \"");
3990 c_write(commentp
, commentlen
);
3991 c_write_str("\" from agent\r\n");
3995 * Server is willing to accept the key.
3996 * Construct a SIGN_REQUEST.
3998 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3999 ssh2_pkt_addstring(username
);
4000 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4001 ssh2_pkt_addstring("publickey"); /* method */
4002 ssh2_pkt_addbool(TRUE
);
4003 ssh2_pkt_addstring_start();
4004 ssh2_pkt_addstring_data(alg
, alglen
);
4005 ssh2_pkt_addstring_start();
4006 ssh2_pkt_addstring_data(pkblob
, pklen
);
4008 siglen
= pktout
.length
- 5 + 4 + 20;
4009 len
= 1; /* message type */
4010 len
+= 4 + pklen
; /* key blob */
4011 len
+= 4 + siglen
; /* data to sign */
4012 len
+= 4; /* flags */
4013 agentreq
= smalloc(4 + len
);
4014 PUT_32BIT(agentreq
, len
);
4016 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
4017 PUT_32BIT(q
, pklen
);
4019 memcpy(q
, pkblob
, pklen
);
4021 PUT_32BIT(q
, siglen
);
4023 /* Now the data to be signed... */
4026 memcpy(q
, ssh2_session_id
, 20);
4028 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
4029 q
+= pktout
.length
- 5;
4030 /* And finally the (zero) flags word. */
4032 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
4036 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
4037 logevent("Sending Pageant's response");
4038 ssh2_pkt_addstring_start();
4039 ssh2_pkt_addstring_data(ret
+ 9,
4047 ("Pageant failed to answer challenge");
4057 if (!method
&& can_pubkey
&& *cfg
.keyfile
4058 && !tried_pubkey_config
) {
4059 unsigned char *pub_blob
;
4060 char *algorithm
, *comment
;
4063 tried_pubkey_config
= TRUE
;
4066 * Try the public key supplied in the configuration.
4068 * First, offer the public blob to see if the server is
4069 * willing to accept it.
4071 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4074 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4075 ssh2_pkt_addstring(username
);
4076 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4077 ssh2_pkt_addstring("publickey"); /* method */
4078 ssh2_pkt_addbool(FALSE
); /* no signature included */
4079 ssh2_pkt_addstring(algorithm
);
4080 ssh2_pkt_addstring_start();
4081 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4083 logevent("Offered public key"); /* FIXME */
4085 crWaitUntilV(ispkt
);
4086 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4088 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4089 continue; /* key refused; give up on it */
4092 logevent("Offer of public key accepted");
4094 * Actually attempt a serious authentication using
4097 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4099 "Passphrase for key \"%.100s\": ",
4105 c_write_str("Authenticating with public key \"");
4106 c_write_str(comment
);
4107 c_write_str("\"\r\n");
4108 method
= AUTH_PUBLICKEY_FILE
;
4112 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4113 method
= AUTH_KEYBOARD_INTERACTIVE
;
4114 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4115 tried_keyb_inter
= TRUE
;
4117 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4118 ssh2_pkt_addstring(username
);
4119 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4120 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4121 ssh2_pkt_addstring(""); /* lang */
4122 ssh2_pkt_addstring("");
4125 crWaitUntilV(ispkt
);
4126 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4127 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4129 logevent("Keyboard-interactive authentication refused");
4130 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4134 kbd_inter_running
= TRUE
;
4137 if (kbd_inter_running
) {
4138 method
= AUTH_KEYBOARD_INTERACTIVE
;
4139 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4140 tried_keyb_inter
= TRUE
;
4142 /* We've got packet with that "interactive" info
4143 dump banners, and set its prompt as ours */
4145 char *name
, *inst
, *lang
, *prompt
;
4146 int name_len
, inst_len
, lang_len
, prompt_len
;
4147 ssh2_pkt_getstring(&name
, &name_len
);
4148 ssh2_pkt_getstring(&inst
, &inst_len
);
4149 ssh2_pkt_getstring(&lang
, &lang_len
);
4151 c_write_untrusted(name
, name_len
);
4153 c_write_untrusted(inst
, inst_len
);
4154 num_prompts
= ssh2_pkt_getuint32();
4156 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4157 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4158 pwprompt
[prompt_len
< sizeof(pwprompt
) ?
4159 prompt_len
: sizeof(pwprompt
)-1] = '\0';
4162 echo
= ssh2_pkt_getbool();
4166 if (!method
&& can_passwd
) {
4167 method
= AUTH_PASSWORD
;
4168 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4175 if (!ssh_get_line(pwprompt
, password
,
4176 sizeof(password
), TRUE
)) {
4178 * get_line failed to get a password (for
4179 * example because one was supplied on the
4180 * command line which has already failed to
4183 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4184 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4186 ("No more passwords available to try");
4187 ssh2_pkt_addstring("en"); /* language tag */
4189 connection_fatal("Unable to authenticate");
4190 ssh_state
= SSH_STATE_CLOSED
;
4197 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4202 crWaitUntilV(!ispkt
);
4204 switch (c
= *in
++) {
4225 if (pos
< sizeof(password
)-1)
4226 password
[pos
++] = c
;
4230 c_write_str("\r\n");
4234 if (method
== AUTH_PUBLICKEY_FILE
) {
4236 * We have our passphrase. Now try the actual authentication.
4238 struct ssh2_userkey
*key
;
4240 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4241 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4242 if (key
== SSH2_WRONG_PASSPHRASE
) {
4243 c_write_str("Wrong passphrase\r\n");
4244 tried_pubkey_config
= FALSE
;
4246 c_write_str("Unable to load private key\r\n");
4247 tried_pubkey_config
= TRUE
;
4249 /* Send a spurious AUTH_NONE to return to the top. */
4250 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4251 ssh2_pkt_addstring(username
);
4252 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4253 ssh2_pkt_addstring("none"); /* method */
4255 type
= AUTH_TYPE_NONE
;
4257 unsigned char *blob
, *sigdata
;
4258 int blob_len
, sigdata_len
;
4261 * We have loaded the private key and the server
4262 * has announced that it's willing to accept it.
4263 * Hallelujah. Generate a signature and send it.
4265 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4266 ssh2_pkt_addstring(username
);
4267 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4268 ssh2_pkt_addstring("publickey"); /* method */
4269 ssh2_pkt_addbool(TRUE
);
4270 ssh2_pkt_addstring(key
->alg
->name
);
4271 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4272 ssh2_pkt_addstring_start();
4273 ssh2_pkt_addstring_data(blob
, blob_len
);
4277 * The data to be signed is:
4281 * followed by everything so far placed in the
4284 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4285 sigdata
= smalloc(sigdata_len
);
4286 PUT_32BIT(sigdata
, 20);
4287 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4288 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4291 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4293 ssh2_pkt_addstring_start();
4294 ssh2_pkt_addstring_data(blob
, blob_len
);
4299 type
= AUTH_TYPE_PUBLICKEY
;
4301 } else if (method
== AUTH_PASSWORD
) {
4303 * We send the password packet lumped tightly together with
4304 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4305 * string long enough to make the total length of the two
4306 * packets constant. This should ensure that a passive
4307 * listener doing traffic analyis can't work out the length
4310 * For this to work, we need an assumption about the
4311 * maximum length of the password packet. I think 256 is
4312 * pretty conservative. Anyone using a password longer than
4313 * that probably doesn't have much to worry about from
4314 * people who find out how long their password is!
4316 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4317 ssh2_pkt_addstring(username
);
4318 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4319 ssh2_pkt_addstring("password");
4320 ssh2_pkt_addbool(FALSE
);
4321 ssh2_pkt_addstring(password
);
4324 * We'll include a string that's an exact multiple of the
4325 * cipher block size. If the cipher is NULL for some
4326 * reason, we don't do this trick at all because we gain
4332 stringlen
= (256 - deferred_len
);
4333 stringlen
+= cscipher
->blksize
- 1;
4334 stringlen
-= (stringlen
% cscipher
->blksize
);
4337 * Temporarily disable actual compression,
4338 * so we can guarantee to get this string
4339 * exactly the length we want it. The
4340 * compression-disabling routine should
4341 * return an integer indicating how many
4342 * bytes we should adjust our string length
4345 stringlen
-= cscomp
->disable_compression();
4347 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4348 ssh2_pkt_addstring_start();
4349 for (i
= 0; i
< stringlen
; i
++) {
4350 char c
= (char) random_byte();
4351 ssh2_pkt_addstring_data(&c
, 1);
4355 ssh_pkt_defersend();
4356 logevent("Sent password");
4357 type
= AUTH_TYPE_PASSWORD
;
4358 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4359 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4360 ssh2_pkt_adduint32(num_prompts
);
4361 ssh2_pkt_addstring(password
);
4362 memset(password
, 0, sizeof(password
));
4364 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4367 ("No supported authentication methods left to try!\r\n");
4369 ("No supported authentications offered. Disconnecting");
4370 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4371 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4373 ("No supported authentication methods available");
4374 ssh2_pkt_addstring("en"); /* language tag */
4376 ssh_state
= SSH_STATE_CLOSED
;
4380 } while (!we_are_in
);
4383 * Now we're authenticated for the connection protocol. The
4384 * connection protocol will automatically have started at this
4385 * point; there's no need to send SERVICE_REQUEST.
4389 * So now create a channel with a session in it.
4391 ssh_channels
= newtree234(ssh_channelcmp
);
4392 mainchan
= smalloc(sizeof(struct ssh_channel
));
4393 mainchan
->localid
= alloc_channel_id();
4394 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4395 ssh2_pkt_addstring("session");
4396 ssh2_pkt_adduint32(mainchan
->localid
);
4397 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4398 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4399 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4401 crWaitUntilV(ispkt
);
4402 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4403 bombout(("Server refused to open a session"));
4405 /* FIXME: error data comes back in FAILURE packet */
4407 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4408 bombout(("Server's channel confirmation cited wrong channel"));
4411 mainchan
->remoteid
= ssh2_pkt_getuint32();
4412 mainchan
->type
= CHAN_MAINSESSION
;
4413 mainchan
->closes
= 0;
4414 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4415 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4416 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4417 add234(ssh_channels
, mainchan
);
4418 logevent("Opened channel for session");
4421 * Potentially enable X11 forwarding.
4423 if (cfg
.x11_forward
) {
4424 char proto
[20], data
[64];
4425 logevent("Requesting X11 forwarding");
4426 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4427 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4428 ssh2_pkt_adduint32(mainchan
->remoteid
);
4429 ssh2_pkt_addstring("x11-req");
4430 ssh2_pkt_addbool(1); /* want reply */
4431 ssh2_pkt_addbool(0); /* many connections */
4432 ssh2_pkt_addstring(proto
);
4433 ssh2_pkt_addstring(data
);
4434 ssh2_pkt_adduint32(0); /* screen number */
4438 crWaitUntilV(ispkt
);
4439 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4440 unsigned i
= ssh2_pkt_getuint32();
4441 struct ssh_channel
*c
;
4442 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4444 continue; /* nonexistent channel */
4445 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4447 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4449 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4450 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4451 bombout(("Unexpected response to X11 forwarding request:"
4452 " packet type %d", pktin
.type
));
4455 logevent("X11 forwarding refused");
4457 logevent("X11 forwarding enabled");
4458 ssh_X11_fwd_enabled
= TRUE
;
4463 * Enable port forwardings.
4466 static char *e
; /* preserve across crReturn */
4470 char sports
[256], dports
[256], host
[256];
4473 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4474 /* Add port forwardings. */
4479 while (*e
&& *e
!= '\t')
4485 while (*e
&& *e
!= ':')
4495 dport
= atoi(dports
);
4496 sport
= atoi(sports
);
4497 if (sport
&& dport
) {
4499 pfd_addforward(host
, dport
, sport
);
4500 sprintf(buf
, "Local port %d forwarding to %s:%d",
4501 sport
, host
, dport
);
4504 struct ssh_rportfwd
*pf
;
4505 pf
= smalloc(sizeof(*pf
));
4506 strcpy(pf
->dhost
, host
);
4509 if (add234(ssh_rportfwds
, pf
) != pf
) {
4511 "Duplicate remote port forwarding to %s:%d",
4516 sprintf(buf
, "Requesting remote port %d (forwarded to %s:%d)",
4517 sport
, host
, dport
);
4519 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4520 ssh2_pkt_addstring("tcpip-forward");
4521 ssh2_pkt_addbool(1);/* want reply */
4522 ssh2_pkt_addstring("127.0.0.1");
4523 ssh2_pkt_adduint32(sport
);
4527 crWaitUntilV(ispkt
);
4528 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4529 unsigned i
= ssh2_pkt_getuint32();
4530 struct ssh_channel
*c
;
4531 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4533 continue;/* nonexistent channel */
4534 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4536 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4538 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4539 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4540 bombout(("Unexpected response to port "
4541 "forwarding request: packet type %d",
4545 logevent("Server refused this port forwarding");
4547 logevent("Remote port forwarding enabled");
4556 * Potentially enable agent forwarding.
4558 if (cfg
.agentfwd
&& agent_exists()) {
4559 logevent("Requesting OpenSSH-style agent forwarding");
4560 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4561 ssh2_pkt_adduint32(mainchan
->remoteid
);
4562 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4563 ssh2_pkt_addbool(1); /* want reply */
4567 crWaitUntilV(ispkt
);
4568 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4569 unsigned i
= ssh2_pkt_getuint32();
4570 struct ssh_channel
*c
;
4571 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4573 continue; /* nonexistent channel */
4574 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4576 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4578 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4579 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4580 bombout(("Unexpected response to agent forwarding request:"
4581 " packet type %d", pktin
.type
));
4584 logevent("Agent forwarding refused");
4586 logevent("Agent forwarding enabled");
4587 ssh_agentfwd_enabled
= TRUE
;
4592 * Now allocate a pty for the session.
4595 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4596 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4597 ssh2_pkt_addstring("pty-req");
4598 ssh2_pkt_addbool(1); /* want reply */
4599 ssh2_pkt_addstring(cfg
.termtype
);
4600 ssh2_pkt_adduint32(cols
);
4601 ssh2_pkt_adduint32(rows
);
4602 ssh2_pkt_adduint32(0); /* pixel width */
4603 ssh2_pkt_adduint32(0); /* pixel height */
4604 ssh2_pkt_addstring_start();
4605 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4607 ssh_state
= SSH_STATE_INTERMED
;
4610 crWaitUntilV(ispkt
);
4611 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4612 unsigned i
= ssh2_pkt_getuint32();
4613 struct ssh_channel
*c
;
4614 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4616 continue; /* nonexistent channel */
4617 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4619 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4621 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4622 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4623 bombout(("Unexpected response to pty request:"
4624 " packet type %d", pktin
.type
));
4627 c_write_str("Server refused to allocate pty\r\n");
4628 ssh_editing
= ssh_echoing
= 1;
4630 logevent("Allocated pty");
4633 ssh_editing
= ssh_echoing
= 1;
4637 * Start a shell or a remote command. We may have to attempt
4638 * this twice if the config data has provided a second choice
4645 if (ssh_fallback_cmd
) {
4646 subsys
= cfg
.ssh_subsys2
;
4647 cmd
= cfg
.remote_cmd_ptr2
;
4649 subsys
= cfg
.ssh_subsys
;
4650 cmd
= cfg
.remote_cmd_ptr
;
4653 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4654 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4656 ssh2_pkt_addstring("subsystem");
4657 ssh2_pkt_addbool(1); /* want reply */
4658 ssh2_pkt_addstring(cmd
);
4660 ssh2_pkt_addstring("exec");
4661 ssh2_pkt_addbool(1); /* want reply */
4662 ssh2_pkt_addstring(cmd
);
4664 ssh2_pkt_addstring("shell");
4665 ssh2_pkt_addbool(1); /* want reply */
4669 crWaitUntilV(ispkt
);
4670 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4671 unsigned i
= ssh2_pkt_getuint32();
4672 struct ssh_channel
*c
;
4673 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4675 continue; /* nonexistent channel */
4676 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4678 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4679 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4680 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4681 bombout(("Unexpected response to shell/command request:"
4682 " packet type %d", pktin
.type
));
4686 * We failed to start the command. If this is the
4687 * fallback command, we really are finished; if it's
4688 * not, and if the fallback command exists, try falling
4689 * back to it before complaining.
4691 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
4692 logevent("Primary command failed; attempting fallback");
4693 ssh_fallback_cmd
= TRUE
;
4696 bombout(("Server refused to start a shell/command"));
4699 logevent("Started a shell/command");
4704 ssh_state
= SSH_STATE_SESSION
;
4708 ssh_special(TS_EOF
);
4713 ldisc_send(NULL
, 0, 0); /* cause ldisc to notice changes */
4716 static int try_send
;
4720 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
4721 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
4724 unsigned i
= ssh2_pkt_getuint32();
4725 struct ssh_channel
*c
;
4726 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4728 continue; /* nonexistent channel */
4729 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
4730 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
4731 continue; /* extended but not stderr */
4732 ssh2_pkt_getstring(&data
, &length
);
4735 c
->v
.v2
.locwindow
-= length
;
4737 case CHAN_MAINSESSION
:
4739 from_backend(pktin
.type
==
4740 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
4744 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
4747 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
4750 while (length
> 0) {
4751 if (c
->u
.a
.lensofar
< 4) {
4752 int l
= min(4 - c
->u
.a
.lensofar
, length
);
4753 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
4757 c
->u
.a
.lensofar
+= l
;
4759 if (c
->u
.a
.lensofar
== 4) {
4761 4 + GET_32BIT(c
->u
.a
.msglen
);
4762 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
4763 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
4765 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
4767 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
4769 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
4773 c
->u
.a
.lensofar
+= l
;
4775 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
4776 void *reply
, *sentreply
;
4778 agent_query(c
->u
.a
.message
,
4779 c
->u
.a
.totallen
, &reply
,
4784 /* Fake SSH_AGENT_FAILURE. */
4785 sentreply
= "\0\0\0\1\5";
4788 ssh2_add_channel_data(c
, sentreply
,
4793 sfree(c
->u
.a
.message
);
4794 c
->u
.a
.lensofar
= 0;
4801 * If we are not buffering too much data,
4802 * enlarge the window again at the remote side.
4804 if (bufsize
< OUR_V2_WINSIZE
)
4805 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
4807 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
4808 ssh_state
= SSH_STATE_CLOSED
;
4809 logevent("Received disconnect message");
4811 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
4812 unsigned i
= ssh2_pkt_getuint32();
4813 struct ssh_channel
*c
;
4815 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4817 continue; /* nonexistent channel */
4819 if (c
->type
== CHAN_X11
) {
4821 * Remote EOF on an X11 channel means we should
4822 * wrap up and close the channel ourselves.
4824 x11_close(c
->u
.x11
.s
);
4826 } else if (c
->type
== CHAN_AGENT
) {
4828 } else if (c
->type
== CHAN_SOCKDATA
) {
4829 pfd_close(c
->u
.pfd
.s
);
4832 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
4833 unsigned i
= ssh2_pkt_getuint32();
4834 struct ssh_channel
*c
;
4836 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4838 continue; /* nonexistent channel */
4839 /* Do pre-close processing on the channel. */
4841 case CHAN_MAINSESSION
:
4842 break; /* nothing to see here, move along */
4844 if (c
->u
.x11
.s
!= NULL
)
4845 x11_close(c
->u
.x11
.s
);
4852 if (c
->u
.pfd
.s
!= NULL
)
4853 pfd_close(c
->u
.pfd
.s
);
4857 if (c
->closes
== 0) {
4858 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4859 ssh2_pkt_adduint32(c
->remoteid
);
4862 del234(ssh_channels
, c
);
4863 bufchain_clear(&c
->v
.v2
.outbuffer
);
4867 * See if that was the last channel left open.
4869 if (count234(ssh_channels
) == 0) {
4870 logevent("All channels closed. Disconnecting");
4871 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4872 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4873 ssh2_pkt_addstring("All open channels closed");
4874 ssh2_pkt_addstring("en"); /* language tag */
4876 ssh_state
= SSH_STATE_CLOSED
;
4879 continue; /* remote sends close; ignore (FIXME) */
4880 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4881 unsigned i
= ssh2_pkt_getuint32();
4882 struct ssh_channel
*c
;
4883 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4885 continue; /* nonexistent channel */
4886 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4888 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4889 unsigned i
= ssh2_pkt_getuint32();
4890 struct ssh_channel
*c
;
4891 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4893 continue; /* nonexistent channel */
4894 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4895 continue; /* dunno why they're confirming this */
4896 c
->remoteid
= ssh2_pkt_getuint32();
4897 c
->type
= CHAN_SOCKDATA
;
4898 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4899 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4900 bufchain_init(&c
->v
.v2
.outbuffer
);
4902 pfd_confirm(c
->u
.pfd
.s
);
4905 * We have a pending close on this channel,
4906 * which we decided on before the server acked
4907 * the channel open. So now we know the
4908 * remoteid, we can close it again.
4910 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4911 ssh2_pkt_adduint32(c
->remoteid
);
4914 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
4915 unsigned i
= ssh2_pkt_getuint32();
4916 struct ssh_channel
*c
;
4917 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4919 continue; /* nonexistent channel */
4920 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4921 continue; /* dunno why they're failing this */
4923 logevent("Forwarded connection refused by server");
4925 pfd_close(c
->u
.pfd
.s
);
4927 del234(ssh_channels
, c
);
4929 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
4932 int typelen
, want_reply
;
4933 struct ssh_channel
*c
;
4935 localid
= ssh2_pkt_getuint32();
4936 ssh2_pkt_getstring(&type
, &typelen
);
4937 want_reply
= ssh2_pkt_getbool();
4940 * First, check that the channel exists. Otherwise,
4941 * we can instantly disconnect with a rude message.
4943 c
= find234(ssh_channels
, &localid
, ssh_channelfind
);
4946 sprintf(buf
, "Received channel request for nonexistent"
4947 " channel %d", localid
);
4949 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4950 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4951 ssh2_pkt_addstring(buf
);
4952 ssh2_pkt_addstring("en"); /* language tag */
4954 connection_fatal(buf
);
4955 ssh_state
= SSH_STATE_CLOSED
;
4960 * We don't recognise any form of channel request,
4961 * so we now either ignore the request or respond
4962 * with CHANNEL_FAILURE, depending on want_reply.
4965 ssh2_pkt_init(SSH2_MSG_CHANNEL_FAILURE
);
4966 ssh2_pkt_adduint32(c
->remoteid
);
4969 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
4973 struct ssh_channel
*c
;
4974 unsigned remid
, winsize
, pktsize
;
4975 ssh2_pkt_getstring(&type
, &typelen
);
4976 c
= smalloc(sizeof(struct ssh_channel
));
4978 remid
= ssh2_pkt_getuint32();
4979 winsize
= ssh2_pkt_getuint32();
4980 pktsize
= ssh2_pkt_getuint32();
4982 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
4983 if (!ssh_X11_fwd_enabled
)
4984 error
= "X11 forwarding is not enabled";
4985 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
4987 error
= "Unable to open an X11 connection";
4991 } else if (typelen
== 15 &&
4992 !memcmp(type
, "forwarded-tcpip", 15)) {
4993 struct ssh_rportfwd pf
, *realpf
;
4996 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
4997 pf
.sport
= ssh2_pkt_getuint32();
4998 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
4999 if (realpf
== NULL
) {
5000 error
= "Remote port is not recognised";
5002 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
5005 sprintf(buf
, "Received remote port open request for %s:%d",
5006 realpf
->dhost
, realpf
->dport
);
5009 sprintf(buf
, "Port open failed: %s", e
);
5011 error
= "Port open failed";
5013 logevent("Forwarded port opened successfully");
5014 c
->type
= CHAN_SOCKDATA
;
5017 } else if (typelen
== 22 &&
5018 !memcmp(type
, "auth-agent@openssh.com", 3)) {
5019 if (!ssh_agentfwd_enabled
)
5020 error
= "Agent forwarding is not enabled";
5022 c
->type
= CHAN_AGENT
; /* identify channel type */
5023 c
->u
.a
.lensofar
= 0;
5026 error
= "Unsupported channel type requested";
5029 c
->remoteid
= remid
;
5031 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
5032 ssh2_pkt_adduint32(c
->remoteid
);
5033 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
5034 ssh2_pkt_addstring(error
);
5035 ssh2_pkt_addstring("en"); /* language tag */
5039 c
->localid
= alloc_channel_id();
5041 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5042 c
->v
.v2
.remwindow
= winsize
;
5043 c
->v
.v2
.remmaxpkt
= pktsize
;
5044 bufchain_init(&c
->v
.v2
.outbuffer
);
5045 add234(ssh_channels
, c
);
5046 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
5047 ssh2_pkt_adduint32(c
->remoteid
);
5048 ssh2_pkt_adduint32(c
->localid
);
5049 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
5050 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5054 bombout(("Strange packet received: type %d", pktin
.type
));
5059 * We have spare data. Add it to the channel buffer.
5061 ssh2_add_channel_data(mainchan
, in
, inlen
);
5066 struct ssh_channel
*c
;
5068 * Try to send data on all channels if we can.
5070 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
5071 int bufsize
= ssh2_try_send(c
);
5074 case CHAN_MAINSESSION
:
5075 /* stdin need not receive an unthrottle
5076 * notification since it will be polled */
5079 x11_unthrottle(c
->u
.x11
.s
);
5082 /* agent sockets are request/response and need no
5083 * buffer management */
5086 pfd_unthrottle(c
->u
.pfd
.s
);
5098 * Handle the top-level SSH2 protocol.
5100 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
5102 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
5104 do_ssh2_authconn(in
, inlen
, ispkt
);
5108 * Called to set up the connection.
5110 * Returns an error message, or NULL on success.
5112 static char *ssh_init(char *host
, int port
, char **realhost
, int nodelay
)
5117 if (crypto_startup() == 0)
5118 return "Microsoft high encryption pack not installed!";
5124 ssh1_throttle_count
= 0;
5125 ssh_overall_bufsize
= 0;
5126 ssh_fallback_cmd
= 0;
5128 p
= connect_to_host(host
, port
, realhost
, nodelay
);
5136 * Called to send data down the Telnet connection.
5138 static int ssh_send(char *buf
, int len
)
5140 if (s
== NULL
|| ssh_protocol
== NULL
)
5143 ssh_protocol(buf
, len
, 0);
5145 return ssh_sendbuffer();
5149 * Called to query the current amount of buffered stdin data.
5151 static int ssh_sendbuffer(void)
5155 if (s
== NULL
|| ssh_protocol
== NULL
)
5159 * If the SSH socket itself has backed up, add the total backup
5160 * size on that to any individual buffer on the stdin channel.
5163 if (ssh_throttled_all
)
5164 override_value
= ssh_overall_bufsize
;
5166 if (ssh_version
== 1) {
5167 return override_value
;
5168 } else if (ssh_version
== 2) {
5169 if (!mainchan
|| mainchan
->closes
> 0)
5170 return override_value
;
5172 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5179 * Called to set the size of the window from SSH's POV.
5181 static void ssh_size(void)
5183 switch (ssh_state
) {
5184 case SSH_STATE_BEFORE_SIZE
:
5185 case SSH_STATE_PREPACKET
:
5186 case SSH_STATE_CLOSED
:
5187 break; /* do nothing */
5188 case SSH_STATE_INTERMED
:
5189 size_needed
= TRUE
; /* buffer for later */
5191 case SSH_STATE_SESSION
:
5193 if (ssh_version
== 1) {
5194 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5195 PKT_INT
, rows
, PKT_INT
, cols
,
5196 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5198 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5199 ssh2_pkt_adduint32(mainchan
->remoteid
);
5200 ssh2_pkt_addstring("window-change");
5201 ssh2_pkt_addbool(0);
5202 ssh2_pkt_adduint32(cols
);
5203 ssh2_pkt_adduint32(rows
);
5204 ssh2_pkt_adduint32(0);
5205 ssh2_pkt_adduint32(0);
5214 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5215 * can send an EOF and collect resulting output (e.g. `plink
5218 static void ssh_special(Telnet_Special code
)
5220 if (code
== TS_EOF
) {
5221 if (ssh_state
!= SSH_STATE_SESSION
) {
5223 * Buffer the EOF in case we are pre-SESSION, so we can
5224 * send it as soon as we reach SESSION.
5230 if (ssh_version
== 1) {
5231 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5233 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5234 ssh2_pkt_adduint32(mainchan
->remoteid
);
5237 logevent("Sent EOF message");
5238 } else if (code
== TS_PING
) {
5239 if (ssh_state
== SSH_STATE_CLOSED
5240 || ssh_state
== SSH_STATE_PREPACKET
) return;
5241 if (ssh_version
== 1) {
5242 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5244 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5245 ssh2_pkt_addstring_start();
5253 void *new_sock_channel(Socket s
)
5255 struct ssh_channel
*c
;
5256 c
= smalloc(sizeof(struct ssh_channel
));
5259 c
->remoteid
= -1; /* to be set when open confirmed */
5260 c
->localid
= alloc_channel_id();
5262 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5264 add234(ssh_channels
, c
);
5270 * This is called when stdout/stderr (the entity to which
5271 * from_backend sends data) manages to clear some backlog.
5273 void ssh_unthrottle(int bufsize
)
5275 if (ssh_version
== 1) {
5276 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5277 ssh1_stdout_throttling
= 0;
5281 if (mainchan
&& mainchan
->closes
== 0)
5282 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5286 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5288 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5291 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5294 if (ssh_version
== 1) {
5295 send_packet(SSH1_MSG_PORT_OPEN
,
5296 PKT_INT
, c
->localid
,
5299 //PKT_STR, <org:orgport>,
5302 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5303 ssh2_pkt_addstring("direct-tcpip");
5304 ssh2_pkt_adduint32(c
->localid
);
5305 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5306 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5307 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5308 ssh2_pkt_addstring(hostname
);
5309 ssh2_pkt_adduint32(port
);
5311 * We make up values for the originator data; partly it's
5312 * too much hassle to keep track, and partly I'm not
5313 * convinced the server should be told details like that
5314 * about my local network configuration.
5316 ssh2_pkt_addstring("client-side-connection");
5317 ssh2_pkt_adduint32(0);
5323 static Socket
ssh_socket(void)
5328 static int ssh_sendok(void)
5333 static int ssh_ldisc(int option
)
5335 if (option
== LD_ECHO
)
5337 if (option
== LD_EDIT
)
5342 Backend ssh_backend
= {