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
163 #define GET_32BIT(cp) \
164 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
165 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
166 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
167 ((unsigned long)(unsigned char)(cp)[3]))
169 #define PUT_32BIT(cp, value) { \
170 (cp)[0] = (unsigned char)((value) >> 24); \
171 (cp)[1] = (unsigned char)((value) >> 16); \
172 (cp)[2] = (unsigned char)((value) >> 8); \
173 (cp)[3] = (unsigned char)(value); }
175 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
177 /* Coroutine mechanics for the sillier bits of the code */
178 #define crBegin1 static int crLine = 0;
179 #define crBegin2 switch(crLine) { case 0:;
180 #define crBegin crBegin1; crBegin2;
181 #define crFinish(z) } crLine = 0; return (z)
182 #define crFinishV } crLine = 0; return
183 #define crReturn(z) \
185 crLine=__LINE__; return (z); case __LINE__:;\
189 crLine=__LINE__; return; case __LINE__:;\
191 #define crStop(z) do{ crLine = 0; return (z); }while(0)
192 #define crStopV do{ crLine = 0; return; }while(0)
193 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
194 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
196 extern char *x11_init(Socket
*, char *, void *);
197 extern void x11_close(Socket
);
198 extern int x11_send(Socket
, char *, int);
199 extern void x11_invent_auth(char *, int, char *, int);
200 extern void x11_unthrottle(Socket s
);
201 extern void x11_override_throttle(Socket s
, int enable
);
203 extern char *pfd_newconnect(Socket
* s
, char *hostname
, int port
, void *c
);
204 extern char *pfd_addforward(char *desthost
, int destport
, int port
);
205 extern void pfd_close(Socket s
);
206 extern int pfd_send(Socket s
, char *data
, int len
);
207 extern void pfd_confirm(Socket s
);
208 extern void pfd_unthrottle(Socket s
);
209 extern void pfd_override_throttle(Socket s
, int enable
);
212 * Buffer management constants. There are several of these for
213 * various different purposes:
215 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
216 * on a local data stream before we throttle the whole SSH
217 * connection (in SSH1 only). Throttling the whole connection is
218 * pretty drastic so we set this high in the hope it won't
221 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
222 * on the SSH connection itself before we defensively throttle
223 * _all_ local data streams. This is pretty drastic too (though
224 * thankfully unlikely in SSH2 since the window mechanism should
225 * ensure that the server never has any need to throttle its end
226 * of the connection), so we set this high as well.
228 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
232 #define SSH1_BUFFER_LIMIT 32768
233 #define SSH_MAX_BACKLOG 32768
234 #define OUR_V2_WINSIZE 16384
237 * Ciphers for SSH2. We miss out single-DES because it isn't
238 * supported; also 3DES and Blowfish are both done differently from
239 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
240 * endianness and different-sized keys.)
242 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
)--;
611 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
612 st
->len
= 0x300; /* big enough to carry to end */
616 st
->pad
= 8 - (st
->len
% 8);
617 st
->biglen
= st
->len
+ st
->pad
;
618 pktin
.length
= st
->len
- 5;
620 if (pktin
.maxlen
< st
->biglen
) {
621 pktin
.maxlen
= st
->biglen
;
622 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+ APIEXTRA
) :
623 srealloc(pktin
.data
, st
->biglen
+ APIEXTRA
));
625 fatalbox("Out of memory");
628 st
->to_read
= st
->biglen
;
630 while (st
->to_read
> 0) {
631 st
->chunk
= st
->to_read
;
632 while ((*datalen
) == 0)
633 crReturn(st
->to_read
);
634 if (st
->chunk
> (*datalen
))
635 st
->chunk
= (*datalen
);
636 memcpy(st
->p
, *data
, st
->chunk
);
638 *datalen
-= st
->chunk
;
640 st
->to_read
-= st
->chunk
;
644 cipher
->decrypt(pktin
.data
, st
->biglen
);
646 debug(("Got packet len=%d pad=%d\n", st
->len
, st
->pad
));
647 dmemdump(pktin
.data
, st
->biglen
);
650 st
->realcrc
= crc32(pktin
.data
, st
->biglen
- 4);
651 st
->gotcrc
= GET_32BIT(pktin
.data
+ st
->biglen
- 4);
652 if (st
->gotcrc
!= st
->realcrc
) {
653 bombout(("Incorrect CRC received on packet"));
657 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
659 if (ssh1_compressing
) {
660 unsigned char *decompblk
;
663 debug(("Packet payload pre-decompression:\n"));
664 dmemdump(pktin
.body
- 1, pktin
.length
+ 1);
666 zlib_decompress_block(pktin
.body
- 1, pktin
.length
+ 1,
667 &decompblk
, &decomplen
);
669 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
670 pktin
.maxlen
= st
->pad
+ decomplen
;
671 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+ APIEXTRA
);
672 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
674 fatalbox("Out of memory");
677 memcpy(pktin
.body
- 1, decompblk
, decomplen
);
679 pktin
.length
= decomplen
- 1;
681 debug(("Packet payload post-decompression:\n"));
682 dmemdump(pktin
.body
- 1, pktin
.length
+ 1);
686 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
687 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
688 pktin
.type
== SSH1_MSG_DEBUG
||
689 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
690 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
691 long strlen
= GET_32BIT(pktin
.body
);
692 if (strlen
+ 4 != pktin
.length
) {
693 bombout(("Received data packet with bogus string length"));
698 pktin
.type
= pktin
.body
[-1];
700 if (pktin
.type
== SSH1_MSG_DEBUG
) {
701 /* log debug message */
703 int strlen
= GET_32BIT(pktin
.body
);
704 strcpy(buf
, "Remote: ");
707 memcpy(buf
+ 8, pktin
.body
+ 4, strlen
);
708 buf
[8 + strlen
] = '\0';
711 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
716 if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
717 /* log reason code in disconnect message */
719 unsigned msglen
= GET_32BIT(pktin
.body
);
721 strcpy(buf
, "Remote sent disconnect: ");
722 nowlen
= strlen(buf
);
723 if (msglen
> sizeof(buf
) - nowlen
- 1)
724 msglen
= sizeof(buf
) - nowlen
- 1;
725 memcpy(buf
+ nowlen
, pktin
.body
+ 4, msglen
);
726 buf
[nowlen
+ msglen
] = '\0';
728 bombout(("Server sent disconnect message:\n\"%s\"", buf
+nowlen
));
734 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
736 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
744 st
->cipherblk
= sccipher
->blksize
;
747 if (st
->cipherblk
< 8)
750 if (pktin
.maxlen
< st
->cipherblk
) {
751 pktin
.maxlen
= st
->cipherblk
;
754 NULL ?
smalloc(st
->cipherblk
+
755 APIEXTRA
) : srealloc(pktin
.data
,
759 fatalbox("Out of memory");
763 * Acquire and decrypt the first block of the packet. This will
764 * contain the length and padding details.
766 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
767 while ((*datalen
) == 0)
768 crReturn(st
->cipherblk
- st
->i
);
769 pktin
.data
[st
->i
] = *(*data
)++;
773 if (!memcmp(pktin
.data
, "Remo", 4)) { /* "Remo"te server has closed ... */
778 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
781 * Now get the length and padding figures.
783 st
->len
= GET_32BIT(pktin
.data
);
784 st
->pad
= pktin
.data
[4];
787 * This enables us to deduce the payload length.
789 st
->payload
= st
->len
- st
->pad
- 1;
791 pktin
.length
= st
->payload
+ 5;
794 * So now we can work out the total packet length.
796 st
->packetlen
= st
->len
+ 4;
797 st
->maclen
= scmac ? scmac
->len
: 0;
800 * Adjust memory allocation if packet is too big.
802 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
803 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
806 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
811 fatalbox("Out of memory");
815 * Read and decrypt the remainder of the packet.
817 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
819 while ((*datalen
) == 0)
820 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
821 pktin
.data
[st
->i
] = *(*data
)++;
824 /* Decrypt everything _except_ the MAC. */
826 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
827 st
->packetlen
- st
->cipherblk
);
830 debug(("Got packet len=%d pad=%d\n", st
->len
, st
->pad
));
831 dmemdump(pktin
.data
, st
->packetlen
);
838 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
839 st
->incoming_sequence
)) {
840 bombout(("Incorrect MAC received on packet"));
843 st
->incoming_sequence
++; /* whether or not we MACed */
846 * Decompress packet payload.
849 unsigned char *newpayload
;
851 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
852 &newpayload
, &newlen
)) {
853 if (pktin
.maxlen
< newlen
+ 5) {
854 pktin
.maxlen
= newlen
+ 5;
857 NULL ?
smalloc(pktin
.maxlen
+
858 APIEXTRA
) : srealloc(pktin
.data
,
862 fatalbox("Out of memory");
864 pktin
.length
= 5 + newlen
;
865 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
867 debug(("Post-decompression payload:\n"));
868 dmemdump(pktin
.data
+ 5, newlen
);
876 pktin
.type
= pktin
.data
[5];
878 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
879 goto next_packet
; /* FIXME: print DEBUG message */
881 if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
882 /* log reason code in disconnect message */
884 int reason
= GET_32BIT(pktin
.data
+ 6);
885 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
887 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
888 sprintf(buf
, "Received disconnect message (%s)",
889 ssh2_disconnect_reasons
[reason
]);
891 sprintf(buf
, "Received disconnect message (unknown type %d)",
895 strcpy(buf
, "Disconnection message text: ");
896 nowlen
= strlen(buf
);
897 if (msglen
> sizeof(buf
) - nowlen
- 1)
898 msglen
= sizeof(buf
) - nowlen
- 1;
899 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
900 buf
[nowlen
+ msglen
] = '\0';
902 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
904 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
905 ssh2_disconnect_reasons
[reason
] : "unknown",
912 static void ssh1_pktout_size(int len
)
916 len
+= 5; /* type and CRC */
920 pktout
.length
= len
- 5;
921 if (pktout
.maxlen
< biglen
) {
922 pktout
.maxlen
= biglen
;
924 /* Allocate enough buffer space for extra block
925 * for MS CryptEncrypt() */
926 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
927 srealloc(pktout
.data
, biglen
+ 12));
929 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
930 srealloc(pktout
.data
, biglen
+ 4));
933 fatalbox("Out of memory");
935 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
938 static void s_wrpkt_start(int type
, int len
)
940 ssh1_pktout_size(len
);
944 static int s_wrpkt_prepare(void)
946 int pad
, len
, biglen
, i
;
949 pktout
.body
[-1] = pktout
.type
;
952 debug(("Packet payload pre-compression:\n"));
953 dmemdump(pktout
.body
- 1, pktout
.length
+ 1);
956 if (ssh1_compressing
) {
957 unsigned char *compblk
;
959 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
961 ssh1_pktout_size(complen
- 1);
962 memcpy(pktout
.body
- 1, compblk
, complen
);
965 debug(("Packet payload post-compression:\n"));
966 dmemdump(pktout
.body
- 1, pktout
.length
+ 1);
970 len
= pktout
.length
+ 5; /* type and CRC */
974 for (i
= 0; i
< pad
; i
++)
975 pktout
.data
[i
+ 4] = random_byte();
976 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
977 PUT_32BIT(pktout
.data
+ biglen
, crc
);
978 PUT_32BIT(pktout
.data
, len
);
981 debug(("Sending packet len=%d\n", biglen
+ 4));
982 dmemdump(pktout
.data
, biglen
+ 4);
985 cipher
->encrypt(pktout
.data
+ 4, biglen
);
990 static void s_wrpkt(void)
993 len
= s_wrpkt_prepare();
994 backlog
= sk_write(s
, pktout
.data
, len
);
995 if (backlog
> SSH_MAX_BACKLOG
)
996 ssh_throttle_all(1, backlog
);
999 static void s_wrpkt_defer(void)
1002 len
= s_wrpkt_prepare();
1003 if (deferred_len
+ len
> deferred_size
) {
1004 deferred_size
= deferred_len
+ len
+ 128;
1005 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1007 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1008 deferred_len
+= len
;
1012 * Construct a packet with the specified contents.
1014 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1016 unsigned char *p
, *argp
, argchar
;
1017 unsigned long argint
;
1018 int pktlen
, argtype
, arglen
;
1022 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1025 (void) va_arg(ap1
, int);
1029 (void) va_arg(ap1
, char);
1033 (void) va_arg(ap1
, unsigned char *);
1034 arglen
= va_arg(ap1
, int);
1038 argp
= va_arg(ap1
, unsigned char *);
1039 arglen
= strlen(argp
);
1040 pktlen
+= 4 + arglen
;
1043 bn
= va_arg(ap1
, Bignum
);
1044 pktlen
+= ssh1_bignum_length(bn
);
1051 s_wrpkt_start(pkttype
, pktlen
);
1054 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1057 argint
= va_arg(ap2
, int);
1058 PUT_32BIT(p
, argint
);
1062 argchar
= va_arg(ap2
, unsigned char);
1067 argp
= va_arg(ap2
, unsigned char *);
1068 arglen
= va_arg(ap2
, int);
1069 memcpy(p
, argp
, arglen
);
1073 argp
= va_arg(ap2
, unsigned char *);
1074 arglen
= strlen(argp
);
1075 PUT_32BIT(p
, arglen
);
1076 memcpy(p
+ 4, argp
, arglen
);
1080 bn
= va_arg(ap2
, Bignum
);
1081 p
+= ssh1_write_bignum(p
, bn
);
1087 static void send_packet(int pkttype
, ...)
1090 va_start(ap1
, pkttype
);
1091 va_start(ap2
, pkttype
);
1092 construct_packet(pkttype
, ap1
, ap2
);
1096 static void defer_packet(int pkttype
, ...)
1099 va_start(ap1
, pkttype
);
1100 va_start(ap2
, pkttype
);
1101 construct_packet(pkttype
, ap1
, ap2
);
1105 static int ssh_versioncmp(char *a
, char *b
)
1108 unsigned long av
, bv
;
1110 av
= strtoul(a
, &ae
, 10);
1111 bv
= strtoul(b
, &be
, 10);
1113 return (av
< bv ?
-1 : +1);
1118 av
= strtoul(ae
, &ae
, 10);
1119 bv
= strtoul(be
, &be
, 10);
1121 return (av
< bv ?
-1 : +1);
1127 * Utility routines for putting an SSH-protocol `string' and
1128 * `uint32' into a SHA state.
1131 static void sha_string(SHA_State
* s
, void *str
, int len
)
1133 unsigned char lenblk
[4];
1134 PUT_32BIT(lenblk
, len
);
1135 SHA_Bytes(s
, lenblk
, 4);
1136 SHA_Bytes(s
, str
, len
);
1139 static void sha_uint32(SHA_State
* s
, unsigned i
)
1141 unsigned char intblk
[4];
1142 PUT_32BIT(intblk
, i
);
1143 SHA_Bytes(s
, intblk
, 4);
1147 * SSH2 packet construction functions.
1149 static void ssh2_pkt_ensure(int length
)
1151 if (pktout
.maxlen
< length
) {
1152 pktout
.maxlen
= length
+ 256;
1155 NULL ?
smalloc(pktout
.maxlen
+
1156 APIEXTRA
) : srealloc(pktout
.data
,
1160 fatalbox("Out of memory");
1163 static void ssh2_pkt_adddata(void *data
, int len
)
1165 pktout
.length
+= len
;
1166 ssh2_pkt_ensure(pktout
.length
);
1167 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1169 static void ssh2_pkt_addbyte(unsigned char byte
)
1171 ssh2_pkt_adddata(&byte
, 1);
1173 static void ssh2_pkt_init(int pkt_type
)
1176 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1178 static void ssh2_pkt_addbool(unsigned char value
)
1180 ssh2_pkt_adddata(&value
, 1);
1182 static void ssh2_pkt_adduint32(unsigned long value
)
1185 PUT_32BIT(x
, value
);
1186 ssh2_pkt_adddata(x
, 4);
1188 static void ssh2_pkt_addstring_start(void)
1190 ssh2_pkt_adduint32(0);
1191 pktout
.savedpos
= pktout
.length
;
1193 static void ssh2_pkt_addstring_str(char *data
)
1195 ssh2_pkt_adddata(data
, strlen(data
));
1196 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1197 pktout
.length
- pktout
.savedpos
);
1199 static void ssh2_pkt_addstring_data(char *data
, int len
)
1201 ssh2_pkt_adddata(data
, len
);
1202 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1203 pktout
.length
- pktout
.savedpos
);
1205 static void ssh2_pkt_addstring(char *data
)
1207 ssh2_pkt_addstring_start();
1208 ssh2_pkt_addstring_str(data
);
1210 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1213 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1216 fatalbox("out of memory");
1218 for (i
= 1; i
<= n
; i
++)
1219 p
[i
] = bignum_byte(b
, n
- i
);
1221 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1223 memmove(p
, p
+ i
, n
+ 1 - i
);
1227 static void ssh2_pkt_addmp(Bignum b
)
1231 p
= ssh2_mpint_fmt(b
, &len
);
1232 ssh2_pkt_addstring_start();
1233 ssh2_pkt_addstring_data(p
, len
);
1238 * Construct an SSH2 final-form packet: compress it, encrypt it,
1239 * put the MAC on it. Final packet, ready to be sent, is stored in
1240 * pktout.data. Total length is returned.
1242 static int ssh2_pkt_construct(void)
1244 int cipherblk
, maclen
, padding
, i
;
1245 static unsigned long outgoing_sequence
= 0;
1248 * Compress packet payload.
1251 debug(("Pre-compression payload:\n"));
1252 dmemdump(pktout
.data
+ 5, pktout
.length
- 5);
1255 unsigned char *newpayload
;
1257 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1258 &newpayload
, &newlen
)) {
1260 ssh2_pkt_adddata(newpayload
, newlen
);
1266 * Add padding. At least four bytes, and must also bring total
1267 * length (minus MAC) up to a multiple of the block size.
1269 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1270 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1273 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1274 maclen
= csmac ? csmac
->len
: 0;
1275 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1276 pktout
.data
[4] = padding
;
1277 for (i
= 0; i
< padding
; i
++)
1278 pktout
.data
[pktout
.length
+ i
] = random_byte();
1279 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1281 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1283 outgoing_sequence
++; /* whether or not we MACed */
1286 debug(("Sending packet len=%d\n", pktout
.length
+ padding
));
1287 dmemdump(pktout
.data
, pktout
.length
+ padding
);
1291 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1293 /* Ready-to-send packet starts at pktout.data. We return length. */
1294 return pktout
.length
+ padding
+ maclen
;
1298 * Construct and send an SSH2 packet immediately.
1300 static void ssh2_pkt_send(void)
1304 len
= ssh2_pkt_construct();
1305 backlog
= sk_write(s
, pktout
.data
, len
);
1306 if (backlog
> SSH_MAX_BACKLOG
)
1307 ssh_throttle_all(1, backlog
);
1311 * Construct an SSH2 packet and add it to a deferred data block.
1312 * Useful for sending multiple packets in a single sk_write() call,
1313 * to prevent a traffic-analysing listener from being able to work
1314 * out the length of any particular packet (such as the password
1317 * Note that because SSH2 sequence-numbers its packets, this can
1318 * NOT be used as an m4-style `defer' allowing packets to be
1319 * constructed in one order and sent in another.
1321 static void ssh2_pkt_defer(void)
1323 int len
= ssh2_pkt_construct();
1324 if (deferred_len
+ len
> deferred_size
) {
1325 deferred_size
= deferred_len
+ len
+ 128;
1326 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1328 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1329 deferred_len
+= len
;
1333 * Send the whole deferred data block constructed by
1334 * ssh2_pkt_defer() or SSH1's defer_packet().
1336 static void ssh_pkt_defersend(void)
1339 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1340 deferred_len
= deferred_size
= 0;
1341 sfree(deferred_send_data
);
1342 deferred_send_data
= NULL
;
1343 if (backlog
> SSH_MAX_BACKLOG
)
1344 ssh_throttle_all(1, backlog
);
1348 void bndebug(char *string
, Bignum b
)
1352 p
= ssh2_mpint_fmt(b
, &len
);
1353 debug(("%s", string
));
1354 for (i
= 0; i
< len
; i
++)
1355 debug((" %02x", p
[i
]));
1361 static void sha_mpint(SHA_State
* s
, Bignum b
)
1365 p
= ssh2_mpint_fmt(b
, &len
);
1366 sha_string(s
, p
, len
);
1371 * SSH2 packet decode functions.
1373 static unsigned long ssh2_pkt_getuint32(void)
1375 unsigned long value
;
1376 if (pktin
.length
- pktin
.savedpos
< 4)
1377 return 0; /* arrgh, no way to decline (FIXME?) */
1378 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1379 pktin
.savedpos
+= 4;
1382 static int ssh2_pkt_getbool(void)
1384 unsigned long value
;
1385 if (pktin
.length
- pktin
.savedpos
< 1)
1386 return 0; /* arrgh, no way to decline (FIXME?) */
1387 value
= pktin
.data
[pktin
.savedpos
] != 0;
1391 static void ssh2_pkt_getstring(char **p
, int *length
)
1394 if (pktin
.length
- pktin
.savedpos
< 4)
1396 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1397 pktin
.savedpos
+= 4;
1398 if (pktin
.length
- pktin
.savedpos
< *length
)
1400 *p
= pktin
.data
+ pktin
.savedpos
;
1401 pktin
.savedpos
+= *length
;
1403 static Bignum
ssh2_pkt_getmp(void)
1409 ssh2_pkt_getstring(&p
, &length
);
1413 bombout(("internal error: Can't handle negative mpints"));
1416 b
= bignum_from_bytes(p
, length
);
1421 * Examine the remote side's version string and compare it against
1422 * a list of known buggy implementations.
1424 static void ssh_detect_bugs(char *vstring
)
1426 char *imp
; /* pointer to implementation part */
1428 imp
+= strcspn(imp
, "-");
1431 imp
+= strcspn(imp
, "-");
1435 ssh_remote_bugs
= 0;
1437 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1438 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1439 !strcmp(imp
, "1.2.22")) {
1441 * These versions don't support SSH1_MSG_IGNORE, so we have
1442 * to use a different defence against password length
1445 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1446 logevent("We believe remote version has SSH1 ignore bug");
1449 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1450 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1451 !strncmp(imp
, "2.1 ", 4)) {
1453 * These versions have the HMAC bug.
1455 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1456 logevent("We believe remote version has SSH2 HMAC bug");
1460 static int do_ssh_init(unsigned char c
)
1463 static char version
[10];
1464 static char *vstring
;
1465 static int vstrsize
;
1471 /* Search for the string "SSH-" in the input. */
1474 static const int transS
[] = { 1, 2, 2, 1 };
1475 static const int transH
[] = { 0, 0, 3, 0 };
1476 static const int transminus
[] = { 0, 0, 0, -1 };
1487 crReturn(1); /* get another character */
1490 vstring
= smalloc(16);
1492 strcpy(vstring
, "SSH-");
1496 crReturn(1); /* get another char */
1497 if (vslen
>= vstrsize
- 1) {
1499 vstring
= srealloc(vstring
, vstrsize
);
1501 vstring
[vslen
++] = c
;
1506 } else if (i
< sizeof(version
) - 1)
1508 } else if (c
== '\n')
1512 ssh_agentfwd_enabled
= FALSE
;
1513 rdpkt2_state
.incoming_sequence
= 0;
1516 vlog
= smalloc(20 + vslen
);
1517 sprintf(vlog
, "Server version: %s", vstring
);
1518 ssh_detect_bugs(vstring
);
1519 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1524 * Server version "1.99" means we can choose whether we use v1
1525 * or v2 protocol. Choice is based on cfg.sshprot.
1527 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1529 * This is a v2 server. Begin v2 protocol.
1531 char verstring
[80], vlog
[100];
1532 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1533 SHA_Init(&exhashbase
);
1535 * Hash our version string and their version string.
1537 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1538 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1539 sprintf(vlog
, "We claim version: %s", verstring
);
1541 strcat(verstring
, "\n");
1542 logevent("Using SSH protocol version 2");
1543 sk_write(s
, verstring
, strlen(verstring
));
1544 ssh_protocol
= ssh2_protocol
;
1546 s_rdpkt
= ssh2_rdpkt
;
1549 * This is a v1 server. Begin v1 protocol.
1551 char verstring
[80], vlog
[100];
1552 sprintf(verstring
, "SSH-%s-%s",
1553 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1555 sprintf(vlog
, "We claim version: %s", verstring
);
1557 strcat(verstring
, "\n");
1558 logevent("Using SSH protocol version 1");
1559 sk_write(s
, verstring
, strlen(verstring
));
1560 ssh_protocol
= ssh1_protocol
;
1562 s_rdpkt
= ssh1_rdpkt
;
1564 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1571 static void ssh_gotdata(unsigned char *data
, int datalen
)
1576 * To begin with, feed the characters one by one to the
1577 * protocol initialisation / selection function do_ssh_init().
1578 * When that returns 0, we're done with the initial greeting
1579 * exchange and can move on to packet discipline.
1584 crReturnV
; /* more data please */
1585 ret
= do_ssh_init(*data
);
1593 * We emerge from that loop when the initial negotiation is
1594 * over and we have selected an s_rdpkt function. Now pass
1595 * everything to s_rdpkt, and then pass the resulting packets
1596 * to the proper protocol handler.
1601 while (datalen
> 0) {
1602 if (s_rdpkt(&data
, &datalen
) == 0) {
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
)
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, &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 unsigned char session_id
[16];
1798 static int cipher_type
;
1799 static char username
[100];
1806 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1807 bombout(("Public key packet not received"));
1811 logevent("Received public keys");
1813 memcpy(cookie
, pktin
.body
, 8);
1815 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1816 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
1819 * Log the host key fingerprint.
1823 logevent("Host key fingerprint is:");
1824 strcpy(logmsg
, " ");
1825 hostkey
.comment
= NULL
;
1826 rsa_fingerprint(logmsg
+ strlen(logmsg
),
1827 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
1831 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
1832 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
1833 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
1835 ssh1_local_protoflags
=
1836 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1837 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1840 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1841 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1842 MD5Update(&md5c
, pktin
.body
, 8);
1843 MD5Final(session_id
, &md5c
);
1845 for (i
= 0; i
< 32; i
++)
1846 session_key
[i
] = random_byte();
1848 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1850 rsabuf
= smalloc(len
);
1852 fatalbox("Out of memory");
1855 * Verify the host key.
1859 * First format the key into a string.
1861 int len
= rsastr_len(&hostkey
);
1862 char fingerprint
[100];
1863 char *keystr
= smalloc(len
);
1865 fatalbox("Out of memory");
1866 rsastr_fmt(keystr
, &hostkey
);
1867 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1868 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
1873 for (i
= 0; i
< 32; i
++) {
1874 rsabuf
[i
] = session_key
[i
];
1876 rsabuf
[i
] ^= session_id
[i
];
1879 if (hostkey
.bytes
> servkey
.bytes
) {
1880 rsaencrypt(rsabuf
, 32, &servkey
);
1881 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1883 rsaencrypt(rsabuf
, 32, &hostkey
);
1884 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1887 logevent("Encrypted session key");
1890 int cipher_chosen
= 0, warn
= 0;
1891 char *cipher_string
= NULL
;
1892 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
1893 int next_cipher
= cfg
.ssh_cipherlist
[i
];
1894 if (next_cipher
== CIPHER_WARN
) {
1895 /* If/when we choose a cipher, warn about it */
1897 } else if (next_cipher
== CIPHER_AES
) {
1898 /* XXX Probably don't need to mention this. */
1899 logevent("AES not supported in SSH1, skipping");
1901 switch (next_cipher
) {
1902 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
1903 cipher_string
= "3DES"; break;
1904 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
1905 cipher_string
= "Blowfish"; break;
1906 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
1907 cipher_string
= "single-DES"; break;
1909 if (supported_ciphers_mask
& (1 << cipher_type
))
1913 if (!cipher_chosen
) {
1914 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
1915 bombout(("Server violates SSH 1 protocol by not "
1916 "supporting 3DES encryption"));
1918 /* shouldn't happen */
1919 bombout(("No supported ciphers found"));
1923 /* Warn about chosen cipher if necessary. */
1925 askcipher(cipher_string
, 0);
1928 switch (cipher_type
) {
1929 case SSH_CIPHER_3DES
:
1930 logevent("Using 3DES encryption");
1932 case SSH_CIPHER_DES
:
1933 logevent("Using single-DES encryption");
1935 case SSH_CIPHER_BLOWFISH
:
1936 logevent("Using Blowfish encryption");
1940 send_packet(SSH1_CMSG_SESSION_KEY
,
1941 PKT_CHAR
, cipher_type
,
1942 PKT_DATA
, cookie
, 8,
1943 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
1944 PKT_DATA
, rsabuf
, len
,
1945 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
1947 logevent("Trying to enable encryption...");
1951 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1952 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
1953 cipher
->sesskey(session_key
);
1957 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1958 bombout(("Encryption not successfully enabled"));
1962 logevent("Successfully started encryption");
1968 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1970 if (!ssh_get_line("login as: ",
1971 username
, sizeof(username
), FALSE
)) {
1973 * get_line failed to get a username.
1976 logevent("No username provided. Abandoning session.");
1977 ssh_state
= SSH_STATE_CLOSED
;
1981 c_write_str("login as: ");
1984 crWaitUntil(!ispkt
);
1986 switch (c
= *in
++) {
1995 c_write_str("\b \b");
2002 c_write_str("\b \b");
2012 if (((c
>= ' ' && c
<= '~') ||
2013 ((unsigned char) c
>= 160))
2014 && pos
< sizeof(username
)-1) {
2015 username
[pos
++] = c
;
2021 c_write_str("\r\n");
2022 username
[strcspn(username
, "\n\r")] = '\0';
2025 strncpy(username
, cfg
.username
, 99);
2026 username
[99] = '\0';
2029 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2031 char userlog
[22 + sizeof(username
)];
2032 sprintf(userlog
, "Sent username \"%s\"", username
);
2034 if (flags
& FLAG_INTERACTIVE
&&
2035 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2036 strcat(userlog
, "\r\n");
2037 c_write_str(userlog
);
2044 tried_publickey
= 0;
2046 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2047 static char password
[100];
2048 static char prompt
[200];
2051 static int pwpkt_type
;
2053 * Show password prompt, having first obtained it via a TIS
2054 * or CryptoCard exchange if we're doing TIS or CryptoCard
2057 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2058 if (agent_exists()) {
2060 * Attempt RSA authentication using Pageant.
2062 static unsigned char request
[5], *response
, *p
;
2063 static int responselen
;
2064 static int i
, nkeys
;
2065 static int authed
= FALSE
;
2068 logevent("Pageant is running. Requesting keys.");
2070 /* Request the keys held by the agent. */
2071 PUT_32BIT(request
, 1);
2072 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2073 agent_query(request
, 5, &r
, &responselen
);
2074 response
= (unsigned char *) r
;
2075 if (response
&& responselen
>= 5 &&
2076 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2078 nkeys
= GET_32BIT(p
);
2082 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2085 for (i
= 0; i
< nkeys
; i
++) {
2086 static struct RSAKey key
;
2087 static Bignum challenge
;
2088 static char *commentp
;
2089 static int commentlen
;
2093 sprintf(buf
, "Trying Pageant key #%d", i
);
2097 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2098 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2099 commentlen
= GET_32BIT(p
);
2103 send_packet(SSH1_CMSG_AUTH_RSA
,
2104 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2106 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2107 logevent("Key refused");
2110 logevent("Received RSA challenge");
2111 ssh1_read_bignum(pktin
.body
, &challenge
);
2113 char *agentreq
, *q
, *ret
;
2116 len
= 1 + 4; /* message type, bit count */
2117 len
+= ssh1_bignum_length(key
.exponent
);
2118 len
+= ssh1_bignum_length(key
.modulus
);
2119 len
+= ssh1_bignum_length(challenge
);
2120 len
+= 16; /* session id */
2121 len
+= 4; /* response format */
2122 agentreq
= smalloc(4 + len
);
2123 PUT_32BIT(agentreq
, len
);
2125 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2126 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2128 q
+= ssh1_write_bignum(q
, key
.exponent
);
2129 q
+= ssh1_write_bignum(q
, key
.modulus
);
2130 q
+= ssh1_write_bignum(q
, challenge
);
2131 memcpy(q
, session_id
, 16);
2133 PUT_32BIT(q
, 1); /* response format */
2134 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2138 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2139 logevent("Sending Pageant's response");
2140 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2141 PKT_DATA
, ret
+ 5, 16,
2145 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2147 ("Pageant's response accepted");
2148 if (flags
& FLAG_VERBOSE
) {
2150 ("Authenticated using RSA key \"");
2151 c_write(commentp
, commentlen
);
2152 c_write_str("\" from agent\r\n");
2157 ("Pageant's response not accepted");
2160 ("Pageant failed to answer challenge");
2164 logevent("No reply received from Pageant");
2167 freebn(key
.exponent
);
2168 freebn(key
.modulus
);
2177 if (*cfg
.keyfile
&& !tried_publickey
)
2178 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2180 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
2182 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
))) {
2183 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2184 logevent("Requested TIS authentication");
2185 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2187 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2188 logevent("TIS authentication declined");
2189 if (flags
& FLAG_INTERACTIVE
)
2190 c_write_str("TIS authentication refused.\r\n");
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
[challengelen
] = '\0';
2203 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
2205 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
))) {
2206 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2207 logevent("Requested CryptoCard authentication");
2208 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2210 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2211 logevent("CryptoCard authentication declined");
2212 c_write_str("CryptoCard authentication refused.\r\n");
2214 int challengelen
= ((pktin
.body
[0] << 24) |
2215 (pktin
.body
[1] << 16) |
2216 (pktin
.body
[2] << 8) |
2218 logevent("Received CryptoCard challenge");
2219 if (challengelen
> sizeof(prompt
) - 1)
2220 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2221 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2222 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
2223 sizeof(prompt
) - challengelen
);
2224 prompt
[sizeof(prompt
) - 1] = '\0';
2227 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2228 sprintf(prompt
, "%.90s@%.90s's password: ",
2229 username
, savedhost
);
2231 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2232 char *comment
= NULL
;
2233 if (flags
& FLAG_VERBOSE
)
2234 c_write_str("Trying public key authentication.\r\n");
2235 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2236 if (flags
& FLAG_VERBOSE
)
2237 c_write_str("No passphrase required.\r\n");
2240 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2245 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2247 * get_line failed to get a password (for example
2248 * because one was supplied on the command line
2249 * which has already failed to work). Terminate.
2251 send_packet(SSH1_MSG_DISCONNECT
,
2252 PKT_STR
, "No more passwords available to try",
2254 connection_fatal("Unable to authenticate");
2255 ssh_state
= SSH_STATE_CLOSED
;
2259 c_write_str(prompt
);
2263 crWaitUntil(!ispkt
);
2265 switch (c
= *in
++) {
2286 if (pos
< sizeof(password
)-1)
2287 password
[pos
++] = c
;
2291 c_write_str("\r\n");
2295 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2297 * Try public key authentication with the specified
2300 static struct RSAKey pubkey
;
2301 static Bignum challenge
, response
;
2303 static unsigned char buffer
[32];
2305 tried_publickey
= 1;
2306 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2308 c_write_str("Couldn't load public key from ");
2309 c_write_str(cfg
.keyfile
);
2310 c_write_str(".\r\n");
2311 continue; /* go and try password */
2314 c_write_str("Wrong passphrase.\r\n");
2315 tried_publickey
= 0;
2316 continue; /* try again */
2320 * Send a public key attempt.
2322 send_packet(SSH1_CMSG_AUTH_RSA
,
2323 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2326 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2327 c_write_str("Server refused our public key.\r\n");
2328 continue; /* go and try password */
2330 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2331 bombout(("Bizarre response to offer of public key"));
2334 ssh1_read_bignum(pktin
.body
, &challenge
);
2335 response
= rsadecrypt(challenge
, &pubkey
);
2336 freebn(pubkey
.private_exponent
); /* burn the evidence */
2338 for (i
= 0; i
< 32; i
++) {
2339 buffer
[i
] = bignum_byte(response
, 31 - i
);
2343 MD5Update(&md5c
, buffer
, 32);
2344 MD5Update(&md5c
, session_id
, 16);
2345 MD5Final(buffer
, &md5c
);
2347 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2348 PKT_DATA
, buffer
, 16, PKT_END
);
2351 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2352 if (flags
& FLAG_VERBOSE
)
2354 ("Failed to authenticate with our public key.\r\n");
2355 continue; /* go and try password */
2356 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2358 ("Bizarre response to RSA authentication response"));
2362 break; /* we're through! */
2364 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2366 * Defence against traffic analysis: we send a
2367 * whole bunch of packets containing strings of
2368 * different lengths. One of these strings is the
2369 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2370 * The others are all random data in
2371 * SSH1_MSG_IGNORE packets. This way a passive
2372 * listener can't tell which is the password, and
2373 * hence can't deduce the password length.
2375 * Anybody with a password length greater than 16
2376 * bytes is going to have enough entropy in their
2377 * password that a listener won't find it _that_
2378 * much help to know how long it is. So what we'll
2381 * - if password length < 16, we send 15 packets
2382 * containing string lengths 1 through 15
2384 * - otherwise, we let N be the nearest multiple
2385 * of 8 below the password length, and send 8
2386 * packets containing string lengths N through
2387 * N+7. This won't obscure the order of
2388 * magnitude of the password length, but it will
2389 * introduce a bit of extra uncertainty.
2391 * A few servers (the old 1.2.18 through 1.2.22)
2392 * can't deal with SSH1_MSG_IGNORE. For these
2393 * servers, we need an alternative defence. We make
2394 * use of the fact that the password is interpreted
2395 * as a C string: so we can append a NUL, then some
2398 if (ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) {
2403 len
= strlen(password
);
2404 if (len
< sizeof(string
)) {
2406 strcpy(string
, password
);
2407 len
++; /* cover the zero byte */
2408 while (len
< sizeof(string
)) {
2409 string
[len
++] = (char) random_byte();
2414 send_packet(pwpkt_type
, PKT_INT
, len
,
2415 PKT_DATA
, s
, len
, PKT_END
);
2417 int bottom
, top
, pwlen
, i
;
2420 pwlen
= strlen(password
);
2422 bottom
= 0; /* zero length passwords are OK! :-) */
2425 bottom
= pwlen
& ~7;
2429 assert(pwlen
>= bottom
&& pwlen
<= top
);
2431 randomstr
= smalloc(top
+ 1);
2433 for (i
= bottom
; i
<= top
; i
++) {
2435 defer_packet(pwpkt_type
, PKT_STR
, password
,
2438 for (j
= 0; j
< i
; j
++) {
2440 randomstr
[j
] = random_byte();
2441 } while (randomstr
[j
] == '\0');
2443 randomstr
[i
] = '\0';
2444 defer_packet(SSH1_MSG_IGNORE
,
2445 PKT_STR
, randomstr
, PKT_END
);
2448 ssh_pkt_defersend();
2451 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2454 logevent("Sent password");
2455 memset(password
, 0, strlen(password
));
2457 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2458 if (flags
& FLAG_VERBOSE
)
2459 c_write_str("Access denied\r\n");
2460 logevent("Authentication refused");
2461 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2462 logevent("Received disconnect request");
2463 ssh_state
= SSH_STATE_CLOSED
;
2465 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2466 bombout(("Strange packet received, type %d", pktin
.type
));
2471 logevent("Authentication successful");
2476 void sshfwd_close(struct ssh_channel
*c
)
2478 if (c
&& !c
->closes
) {
2479 if (ssh_version
== 1) {
2480 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2483 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2484 ssh2_pkt_adduint32(c
->remoteid
);
2488 if (c
->type
== CHAN_X11
) {
2490 logevent("Forwarded X11 connection terminated");
2491 } else if (c
->type
== CHAN_SOCKDATA
) {
2493 logevent("Forwarded port closed");
2498 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2500 if (ssh_version
== 1) {
2501 send_packet(SSH1_MSG_CHANNEL_DATA
,
2502 PKT_INT
, c
->remoteid
,
2503 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2505 * In SSH1 we can return 0 here - implying that forwarded
2506 * connections are never individually throttled - because
2507 * the only circumstance that can cause throttling will be
2508 * the whole SSH connection backing up, in which case
2509 * _everything_ will be throttled as a whole.
2513 ssh2_add_channel_data(c
, buf
, len
);
2514 return ssh2_try_send(c
);
2518 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2520 if (ssh_version
== 1) {
2521 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2522 c
->v
.v1
.throttling
= 0;
2526 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2530 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2536 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2539 if (ssh_state
== SSH_STATE_CLOSED
)
2542 if (cfg
.agentfwd
&& agent_exists()) {
2543 logevent("Requesting agent forwarding");
2544 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2548 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2549 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2550 bombout(("Protocol confusion"));
2552 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2553 logevent("Agent forwarding refused");
2555 logevent("Agent forwarding enabled");
2556 ssh_agentfwd_enabled
= TRUE
;
2560 if (cfg
.x11_forward
) {
2561 char proto
[20], data
[64];
2562 logevent("Requesting X11 forwarding");
2563 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2564 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2565 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2566 PKT_STR
, proto
, PKT_STR
, data
,
2567 PKT_INT
, 0, PKT_END
);
2569 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2570 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2575 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2576 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2577 bombout(("Protocol confusion"));
2579 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2580 logevent("X11 forwarding refused");
2582 logevent("X11 forwarding enabled");
2583 ssh_X11_fwd_enabled
= TRUE
;
2591 char sports
[256], dports
[256], host
[256];
2594 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2595 /* Add port forwardings. */
2600 while (*e
&& *e
!= '\t')
2606 while (*e
&& *e
!= ':')
2616 dport
= atoi(dports
);
2617 sport
= atoi(sports
);
2618 if (sport
&& dport
) {
2620 pfd_addforward(host
, dport
, sport
);
2621 sprintf(buf
, "Local port %d forwarding to %s:%d",
2622 sport
, host
, dport
);
2625 struct ssh_rportfwd
*pf
;
2626 pf
= smalloc(sizeof(*pf
));
2627 strcpy(pf
->dhost
, host
);
2629 if (add234(ssh_rportfwds
, pf
) != pf
) {
2631 "Duplicate remote port forwarding to %s:%d",
2636 sprintf(buf
, "Requesting remote port %d forward to %s:%d",
2637 sport
, host
, dport
);
2639 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2651 send_packet(SSH1_CMSG_REQUEST_PTY
,
2652 PKT_STR
, cfg
.termtype
,
2653 PKT_INT
, rows
, PKT_INT
, cols
,
2654 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2655 ssh_state
= SSH_STATE_INTERMED
;
2659 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2660 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2661 bombout(("Protocol confusion"));
2663 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2664 c_write_str("Server refused to allocate pty\r\n");
2665 ssh_editing
= ssh_echoing
= 1;
2667 logevent("Allocated pty");
2669 ssh_editing
= ssh_echoing
= 1;
2672 if (cfg
.compression
) {
2673 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2677 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2678 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2679 bombout(("Protocol confusion"));
2681 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2682 c_write_str("Server refused to compress\r\n");
2684 logevent("Started compression");
2685 ssh1_compressing
= TRUE
;
2686 zlib_compress_init();
2687 zlib_decompress_init();
2691 * Start the shell or command.
2693 * Special case: if the first-choice command is an SSH2
2694 * subsystem (hence not usable here) and the second choice
2695 * exists, we fall straight back to that.
2698 char *cmd
= cfg
.remote_cmd_ptr
;
2700 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
2701 cmd
= cfg
.remote_cmd_ptr2
;
2702 ssh_fallback_cmd
= TRUE
;
2705 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2707 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2708 logevent("Started session");
2711 ssh_state
= SSH_STATE_SESSION
;
2715 ssh_special(TS_EOF
);
2717 ldisc_send(NULL
, 0); /* cause ldisc to notice changes */
2719 ssh_channels
= newtree234(ssh_channelcmp
);
2723 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2724 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2725 long len
= GET_32BIT(pktin
.body
);
2727 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2728 pktin
.body
+ 4, len
);
2729 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2730 ssh1_stdout_throttling
= 1;
2733 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2734 ssh_state
= SSH_STATE_CLOSED
;
2735 logevent("Received disconnect request");
2737 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2738 /* Remote side is trying to open a channel to talk to our
2739 * X-Server. Give them back a local channel number. */
2740 struct ssh_channel
*c
;
2742 logevent("Received X11 connect request");
2743 /* Refuse if X11 forwarding is disabled. */
2744 if (!ssh_X11_fwd_enabled
) {
2745 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2746 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2747 logevent("Rejected X11 connect request");
2749 c
= smalloc(sizeof(struct ssh_channel
));
2751 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2752 logevent("opening X11 forward connection failed");
2754 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2755 PKT_INT
, GET_32BIT(pktin
.body
),
2759 ("opening X11 forward connection succeeded");
2760 c
->remoteid
= GET_32BIT(pktin
.body
);
2761 c
->localid
= alloc_channel_id();
2763 c
->v
.v1
.throttling
= 0;
2764 c
->type
= CHAN_X11
; /* identify channel type */
2765 add234(ssh_channels
, c
);
2766 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2767 PKT_INT
, c
->remoteid
, PKT_INT
,
2768 c
->localid
, PKT_END
);
2769 logevent("Opened X11 forward channel");
2772 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2773 /* Remote side is trying to open a channel to talk to our
2774 * agent. Give them back a local channel number. */
2775 struct ssh_channel
*c
;
2777 /* Refuse if agent forwarding is disabled. */
2778 if (!ssh_agentfwd_enabled
) {
2779 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2780 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2782 c
= smalloc(sizeof(struct ssh_channel
));
2783 c
->remoteid
= GET_32BIT(pktin
.body
);
2784 c
->localid
= alloc_channel_id();
2786 c
->v
.v1
.throttling
= 0;
2787 c
->type
= CHAN_AGENT
; /* identify channel type */
2788 c
->u
.a
.lensofar
= 0;
2789 add234(ssh_channels
, c
);
2790 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2791 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2794 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
2795 /* Remote side is trying to open a channel to talk to a
2796 * forwarded port. Give them back a local channel number. */
2797 struct ssh_channel
*c
;
2798 struct ssh_rportfwd pf
;
2800 char host
[256], buf
[1024];
2802 c
= smalloc(sizeof(struct ssh_channel
));
2804 hostsize
= GET_32BIT(pktin
.body
+4);
2805 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
2806 if (h
+1 < host
+sizeof(host
))
2811 port
= GET_32BIT(p
);
2813 strcpy(pf
.dhost
, host
);
2816 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
2817 sprintf(buf
, "Rejected remote port open request for %s:%d",
2820 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2821 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2823 sprintf(buf
, "Received remote port open request for %s:%d",
2826 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
2829 sprintf(buf
, "Port open failed: %s", e
);
2832 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2833 PKT_INT
, GET_32BIT(pktin
.body
),
2836 c
->remoteid
= GET_32BIT(pktin
.body
);
2837 c
->localid
= alloc_channel_id();
2839 c
->v
.v1
.throttling
= 0;
2840 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
2841 add234(ssh_channels
, c
);
2842 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2843 PKT_INT
, c
->remoteid
, PKT_INT
,
2844 c
->localid
, PKT_END
);
2845 logevent("Forwarded port opened successfully");
2849 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2850 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2851 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2852 struct ssh_channel
*c
;
2854 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2855 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2856 c
->remoteid
= localid
;
2857 c
->type
= CHAN_SOCKDATA
;
2858 pfd_confirm(c
->u
.pfd
.s
);
2861 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
2862 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2863 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2864 struct ssh_channel
*c
;
2866 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2867 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2868 logevent("Forwarded connection refused by server");
2869 pfd_close(c
->u
.pfd
.s
);
2870 del234(ssh_channels
, c
);
2874 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
2875 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
2876 /* Remote side closes a channel. */
2877 unsigned i
= GET_32BIT(pktin
.body
);
2878 struct ssh_channel
*c
;
2879 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2883 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
2884 if (!(c
->closes
& closetype
))
2885 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
2887 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
2888 logevent("Forwarded X11 connection terminated");
2889 assert(c
->u
.x11
.s
!= NULL
);
2890 x11_close(c
->u
.x11
.s
);
2893 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
2894 logevent("Forwarded port closed");
2895 assert(c
->u
.pfd
.s
!= NULL
);
2896 pfd_close(c
->u
.pfd
.s
);
2899 c
->closes
|= closetype
;
2900 if (c
->closes
== 3) {
2901 del234(ssh_channels
, c
);
2905 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
2906 /* Data sent down one of our channels. */
2907 int i
= GET_32BIT(pktin
.body
);
2908 int len
= GET_32BIT(pktin
.body
+ 4);
2909 unsigned char *p
= pktin
.body
+ 8;
2910 struct ssh_channel
*c
;
2911 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2916 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
2919 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
2922 /* Data for an agent message. Buffer it. */
2924 if (c
->u
.a
.lensofar
< 4) {
2925 int l
= min(4 - c
->u
.a
.lensofar
, len
);
2926 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
2930 c
->u
.a
.lensofar
+= l
;
2932 if (c
->u
.a
.lensofar
== 4) {
2934 4 + GET_32BIT(c
->u
.a
.msglen
);
2935 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
2936 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
2938 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
2940 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
2942 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
2946 c
->u
.a
.lensofar
+= l
;
2948 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
2949 void *reply
, *sentreply
;
2951 agent_query(c
->u
.a
.message
,
2952 c
->u
.a
.totallen
, &reply
,
2957 /* Fake SSH_AGENT_FAILURE. */
2958 sentreply
= "\0\0\0\1\5";
2961 send_packet(SSH1_MSG_CHANNEL_DATA
,
2962 PKT_INT
, c
->remoteid
,
2964 PKT_DATA
, sentreply
, replylen
,
2968 sfree(c
->u
.a
.message
);
2969 c
->u
.a
.lensofar
= 0;
2972 bufsize
= 0; /* agent channels never back up */
2975 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2976 c
->v
.v1
.throttling
= 1;
2980 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2981 /* may be from EXEC_SHELL on some servers */
2982 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2983 /* may be from EXEC_SHELL on some servers
2984 * if no pty is available or in other odd cases. Ignore */
2985 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
2986 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
2988 bombout(("Strange packet received: type %d", pktin
.type
));
2993 int len
= min(inlen
, 512);
2994 send_packet(SSH1_CMSG_STDIN_DATA
,
2995 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3006 * Utility routine for decoding comma-separated strings in KEXINIT.
3008 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3010 int needlen
= strlen(needle
);
3013 * Is it at the start of the string?
3015 if (haylen
>= needlen
&& /* haystack is long enough */
3016 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3017 (haylen
== needlen
|| haystack
[needlen
] == ',')
3018 /* either , or EOS follows */
3022 * If not, search for the next comma and resume after that.
3023 * If no comma found, terminate.
3025 while (haylen
> 0 && *haystack
!= ',')
3026 haylen
--, haystack
++;
3029 haylen
--, haystack
++; /* skip over comma itself */
3034 * SSH2 key creation method.
3036 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3040 /* First 20 bytes. */
3043 SHA_Bytes(&s
, H
, 20);
3044 SHA_Bytes(&s
, &chr
, 1);
3045 SHA_Bytes(&s
, sessid
, 20);
3046 SHA_Final(&s
, keyspace
);
3047 /* Next 20 bytes. */
3050 SHA_Bytes(&s
, H
, 20);
3051 SHA_Bytes(&s
, keyspace
, 20);
3052 SHA_Final(&s
, keyspace
+ 20);
3056 * Handle the SSH2 transport layer.
3058 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3060 static int i
, j
, len
, nbits
, pbits
, warn
;
3062 static Bignum p
, g
, e
, f
, K
;
3063 static int kex_init_value
, kex_reply_value
;
3064 static const struct ssh_mac
**maclist
;
3066 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3067 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3068 static const struct ssh_mac
*csmac_tobe
= NULL
;
3069 static const struct ssh_mac
*scmac_tobe
= NULL
;
3070 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3071 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3072 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3073 static int hostkeylen
, siglen
;
3074 static void *hkey
; /* actual host key */
3075 static unsigned char exchange_hash
[20];
3076 static unsigned char keyspace
[40];
3077 static int n_preferred_ciphers
;
3078 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3079 static const struct ssh_compress
*preferred_comp
;
3080 static int first_kex
;
3087 * Set up the preferred ciphers. (NULL => warn below here)
3089 n_preferred_ciphers
= 0;
3090 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3091 switch (cfg
.ssh_cipherlist
[i
]) {
3092 case CIPHER_BLOWFISH
:
3093 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3094 n_preferred_ciphers
++;
3097 /* Not supported in SSH2; silently drop */
3100 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3101 n_preferred_ciphers
++;
3104 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3105 n_preferred_ciphers
++;
3108 /* Flag for later. Don't bother if it's the last in
3110 if (i
< CIPHER_MAX
- 1) {
3111 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3112 n_preferred_ciphers
++;
3119 * Set up preferred compression.
3121 if (cfg
.compression
)
3122 preferred_comp
= &ssh_zlib
;
3124 preferred_comp
= &ssh_comp_none
;
3127 * Be prepared to work around the buggy MAC problem.
3129 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3130 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3132 maclist
= macs
, nmacs
= lenof(macs
);
3136 * Construct and send our key exchange packet.
3138 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3139 for (i
= 0; i
< 16; i
++)
3140 ssh2_pkt_addbyte((unsigned char) random_byte());
3141 /* List key exchange algorithms. */
3142 ssh2_pkt_addstring_start();
3143 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3144 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3145 if (i
< lenof(kex_algs
) - 1)
3146 ssh2_pkt_addstring_str(",");
3148 /* List server host key algorithms. */
3149 ssh2_pkt_addstring_start();
3150 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3151 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3152 if (i
< lenof(hostkey_algs
) - 1)
3153 ssh2_pkt_addstring_str(",");
3155 /* List client->server encryption algorithms. */
3156 ssh2_pkt_addstring_start();
3157 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3158 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3159 if (!c
) continue; /* warning flag */
3160 for (j
= 0; j
< c
->nciphers
; j
++) {
3161 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3162 if (i
< n_preferred_ciphers
|| j
< c
->nciphers
- 1)
3163 ssh2_pkt_addstring_str(",");
3166 /* List server->client encryption algorithms. */
3167 ssh2_pkt_addstring_start();
3168 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3169 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3170 if (!c
) continue; /* warning flag */
3171 for (j
= 0; j
< c
->nciphers
; j
++) {
3172 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3173 if (i
< n_preferred_ciphers
|| j
< c
->nciphers
- 1)
3174 ssh2_pkt_addstring_str(",");
3177 /* List client->server MAC algorithms. */
3178 ssh2_pkt_addstring_start();
3179 for (i
= 0; i
< nmacs
; i
++) {
3180 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3182 ssh2_pkt_addstring_str(",");
3184 /* List server->client MAC algorithms. */
3185 ssh2_pkt_addstring_start();
3186 for (i
= 0; i
< nmacs
; i
++) {
3187 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3189 ssh2_pkt_addstring_str(",");
3191 /* List client->server compression algorithms. */
3192 ssh2_pkt_addstring_start();
3193 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3194 const struct ssh_compress
*c
=
3195 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3196 ssh2_pkt_addstring_str(c
->name
);
3197 if (i
< lenof(compressions
))
3198 ssh2_pkt_addstring_str(",");
3200 /* List server->client compression algorithms. */
3201 ssh2_pkt_addstring_start();
3202 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3203 const struct ssh_compress
*c
=
3204 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3205 ssh2_pkt_addstring_str(c
->name
);
3206 if (i
< lenof(compressions
))
3207 ssh2_pkt_addstring_str(",");
3209 /* List client->server languages. Empty list. */
3210 ssh2_pkt_addstring_start();
3211 /* List server->client languages. Empty list. */
3212 ssh2_pkt_addstring_start();
3213 /* First KEX packet does _not_ follow, because we're not that brave. */
3214 ssh2_pkt_addbool(FALSE
);
3216 ssh2_pkt_adduint32(0);
3218 exhash
= exhashbase
;
3219 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3225 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3228 * Now examine the other side's KEXINIT to see what we're up
3231 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3232 bombout(("expected key exchange packet from server"));
3237 cscipher_tobe
= NULL
;
3238 sccipher_tobe
= NULL
;
3243 pktin
.savedpos
+= 16; /* skip garbage cookie */
3244 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3245 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3246 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3251 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3252 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3253 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3254 hostkey
= hostkey_algs
[i
];
3258 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3260 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3261 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3265 for (j
= 0; j
< c
->nciphers
; j
++) {
3266 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3267 cscipher_tobe
= c
->list
[j
];
3272 if (cscipher_tobe
) {
3274 askcipher(cscipher_tobe
->name
, 1);
3278 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3280 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3281 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3285 for (j
= 0; j
< c
->nciphers
; j
++) {
3286 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3287 sccipher_tobe
= c
->list
[j
];
3292 if (sccipher_tobe
) {
3294 askcipher(sccipher_tobe
->name
, 2);
3298 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3299 for (i
= 0; i
< nmacs
; i
++) {
3300 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3301 csmac_tobe
= maclist
[i
];
3305 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3306 for (i
= 0; i
< nmacs
; i
++) {
3307 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3308 scmac_tobe
= maclist
[i
];
3312 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3313 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3314 const struct ssh_compress
*c
=
3315 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3316 if (in_commasep_string(c
->name
, str
, len
)) {
3321 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3322 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3323 const struct ssh_compress
*c
=
3324 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3325 if (in_commasep_string(c
->name
, str
, len
)) {
3332 * Work out the number of bits of key we will need from the key
3333 * exchange. We start with the maximum key length of either
3339 csbits
= cscipher_tobe
->keylen
;
3340 scbits
= sccipher_tobe
->keylen
;
3341 nbits
= (csbits
> scbits ? csbits
: scbits
);
3343 /* The keys only have 160-bit entropy, since they're based on
3344 * a SHA-1 hash. So cap the key size at 160 bits. */
3349 * If we're doing Diffie-Hellman group exchange, start by
3350 * requesting a group.
3352 if (kex
== &ssh_diffiehellman_gex
) {
3353 logevent("Doing Diffie-Hellman group exchange");
3355 * Work out how big a DH group we will need to allow that
3358 pbits
= 512 << ((nbits
- 1) / 64);
3359 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3360 ssh2_pkt_adduint32(pbits
);
3364 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3365 bombout(("expected key exchange group packet from server"));
3368 p
= ssh2_pkt_getmp();
3369 g
= ssh2_pkt_getmp();
3370 dh_setup_group(p
, g
);
3371 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3372 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3375 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3376 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3379 logevent("Doing Diffie-Hellman key exchange");
3381 * Now generate and send e for Diffie-Hellman.
3383 e
= dh_create_e(nbits
* 2);
3384 ssh2_pkt_init(kex_init_value
);
3389 if (pktin
.type
!= kex_reply_value
) {
3390 bombout(("expected key exchange reply packet from server"));
3393 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3394 f
= ssh2_pkt_getmp();
3395 ssh2_pkt_getstring(&sigdata
, &siglen
);
3399 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3400 if (kex
== &ssh_diffiehellman_gex
) {
3401 sha_uint32(&exhash
, pbits
);
3402 sha_mpint(&exhash
, p
);
3403 sha_mpint(&exhash
, g
);
3405 sha_mpint(&exhash
, e
);
3406 sha_mpint(&exhash
, f
);
3407 sha_mpint(&exhash
, K
);
3408 SHA_Final(&exhash
, exchange_hash
);
3413 debug(("Exchange hash is:\n"));
3414 dmemdump(exchange_hash
, 20);
3417 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3419 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3420 bombout(("Server's host key did not match the signature supplied"));
3425 * Expect SSH2_MSG_NEWKEYS from server.
3428 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3429 bombout(("expected new-keys packet from server"));
3434 * Authenticate remote host: verify host key. (We've already
3435 * checked the signature of the exchange hash.)
3437 keystr
= hostkey
->fmtkey(hkey
);
3438 fingerprint
= hostkey
->fingerprint(hkey
);
3439 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3440 keystr
, fingerprint
);
3441 if (first_kex
) { /* don't bother logging this in rekeys */
3442 logevent("Host key fingerprint is:");
3443 logevent(fingerprint
);
3447 hostkey
->freekey(hkey
);
3450 * Send SSH2_MSG_NEWKEYS.
3452 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3456 * Create and initialise session keys.
3458 cscipher
= cscipher_tobe
;
3459 sccipher
= sccipher_tobe
;
3462 cscomp
= cscomp_tobe
;
3463 sccomp
= sccomp_tobe
;
3464 cscomp
->compress_init();
3465 sccomp
->decompress_init();
3467 * Set IVs after keys. Here we use the exchange hash from the
3468 * _first_ key exchange.
3471 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3472 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3473 cscipher
->setcskey(keyspace
);
3474 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3475 sccipher
->setsckey(keyspace
);
3476 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3477 cscipher
->setcsiv(keyspace
);
3478 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3479 sccipher
->setsciv(keyspace
);
3480 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3481 csmac
->setcskey(keyspace
);
3482 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3483 scmac
->setsckey(keyspace
);
3486 * If this is the first key exchange phase, we must pass the
3487 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3488 * wants to see it but because it will need time to initialise
3489 * itself before it sees an actual packet. In subsequent key
3490 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3491 * it would only confuse the layer above.
3499 * Now we're encrypting. Begin returning 1 to the protocol main
3500 * function so that other things can run on top of the
3501 * transport. If we ever see a KEXINIT, we must go back to the
3504 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3507 logevent("Server initiated key re-exchange");
3508 goto begin_key_exchange
;
3514 * Add data to an SSH2 channel output buffer.
3516 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3519 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3523 * Attempt to send data on an SSH2 channel.
3525 static int ssh2_try_send(struct ssh_channel
*c
)
3527 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3530 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3531 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3532 len
= c
->v
.v2
.remwindow
;
3533 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3534 len
= c
->v
.v2
.remmaxpkt
;
3535 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3536 ssh2_pkt_adduint32(c
->remoteid
);
3537 ssh2_pkt_addstring_start();
3538 ssh2_pkt_addstring_data(data
, len
);
3540 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3541 c
->v
.v2
.remwindow
-= len
;
3545 * After having sent as much data as we can, return the amount
3548 return bufchain_size(&c
->v
.v2
.outbuffer
);
3552 * Potentially enlarge the window on an SSH2 channel.
3554 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3556 if (newwin
> c
->v
.v2
.locwindow
) {
3557 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3558 ssh2_pkt_adduint32(c
->remoteid
);
3559 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3561 c
->v
.v2
.locwindow
= newwin
;
3566 * Handle the SSH2 userauth and connection layers.
3568 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3571 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3573 AUTH_KEYBOARD_INTERACTIVE
3577 AUTH_TYPE_PUBLICKEY
,
3578 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3579 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3581 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3582 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3584 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3585 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3586 static int kbd_inter_running
;
3587 static int we_are_in
;
3588 static int num_prompts
, echo
;
3589 static char username
[100];
3590 static char pwprompt
[200];
3591 static char password
[100];
3596 * Request userauth protocol, and await a response to it.
3598 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3599 ssh2_pkt_addstring("ssh-userauth");
3601 crWaitUntilV(ispkt
);
3602 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3603 bombout(("Server refused user authentication protocol"));
3608 * We repeat this whole loop, including the username prompt,
3609 * until we manage a successful authentication. If the user
3610 * types the wrong _password_, they are sent back to the
3611 * beginning to try another username. (If they specify a
3612 * username in the config, they are never asked, even if they
3613 * do give a wrong password.)
3615 * I think this best serves the needs of
3617 * - the people who have no configuration, no keys, and just
3618 * want to try repeated (username,password) pairs until they
3619 * type both correctly
3621 * - people who have keys and configuration but occasionally
3622 * need to fall back to passwords
3624 * - people with a key held in Pageant, who might not have
3625 * logged in to a particular machine before; so they want to
3626 * type a username, and then _either_ their key will be
3627 * accepted, _or_ they will type a password. If they mistype
3628 * the username they will want to be able to get back and
3639 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
3641 if (!ssh_get_line("login as: ",
3642 username
, sizeof(username
), FALSE
)) {
3644 * get_line failed to get a username.
3647 logevent("No username provided. Abandoning session.");
3648 ssh_state
= SSH_STATE_CLOSED
;
3652 c_write_str("login as: ");
3655 crWaitUntilV(!ispkt
);
3657 switch (c
= *in
++) {
3666 c_write_str("\b \b");
3673 c_write_str("\b \b");
3683 if (((c
>= ' ' && c
<= '~') ||
3684 ((unsigned char) c
>= 160))
3685 && pos
< sizeof(username
)-1) {
3686 username
[pos
++] = c
;
3693 c_write_str("\r\n");
3694 username
[strcspn(username
, "\n\r")] = '\0';
3697 strncpy(username
, cfg
.username
, 99);
3698 username
[99] = '\0';
3699 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3700 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3706 * Send an authentication request using method "none": (a)
3707 * just in case it succeeds, and (b) so that we know what
3708 * authentication methods we can usefully try next.
3710 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3711 ssh2_pkt_addstring(username
);
3712 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3713 ssh2_pkt_addstring("none"); /* method */
3715 type
= AUTH_TYPE_NONE
;
3719 tried_pubkey_config
= FALSE
;
3720 tried_agent
= FALSE
;
3721 tried_keyb_inter
= FALSE
;
3722 kbd_inter_running
= FALSE
;
3726 * Wait for the result of the last authentication request.
3729 crWaitUntilV(ispkt
);
3730 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
3734 * Don't show the banner if we're operating in
3735 * non-verbose non-interactive mode. (It's probably
3736 * a script, which means nobody will read the
3737 * banner _anyway_, and moreover the printing of
3738 * the banner will screw up processing on the
3739 * output of (say) plink.)
3741 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
3742 ssh2_pkt_getstring(&banner
, &size
);
3744 c_write_untrusted(banner
, size
);
3746 crWaitUntilV(ispkt
);
3748 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
3749 logevent("Access granted");
3754 if (kbd_inter_running
&&
3755 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
3757 * This is a further prompt in keyboard-interactive
3758 * authentication. Do nothing.
3760 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
3761 bombout(("Strange packet received during authentication: type %d",
3769 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3770 * we can look at the string in it and know what we can
3771 * helpfully try next.
3773 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
3776 ssh2_pkt_getstring(&methods
, &methlen
);
3777 kbd_inter_running
= FALSE
;
3778 if (!ssh2_pkt_getbool()) {
3780 * We have received an unequivocal Access
3781 * Denied. This can translate to a variety of
3784 * - if we'd just tried "none" authentication,
3785 * it's not worth printing anything at all
3787 * - if we'd just tried a public key _offer_,
3788 * the message should be "Server refused our
3789 * key" (or no message at all if the key
3790 * came from Pageant)
3792 * - if we'd just tried anything else, the
3793 * message really should be "Access denied".
3795 * Additionally, if we'd just tried password
3796 * authentication, we should break out of this
3797 * whole loop so as to go back to the username
3800 if (type
== AUTH_TYPE_NONE
) {
3802 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
3803 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
3804 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
3805 c_write_str("Server refused our key\r\n");
3806 logevent("Server refused public key");
3807 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
3808 /* server declined keyboard-interactive; ignore */
3810 c_write_str("Access denied\r\n");
3811 logevent("Access denied");
3812 if (type
== AUTH_TYPE_PASSWORD
) {
3818 c_write_str("Further authentication required\r\n");
3819 logevent("Further authentication required");
3823 in_commasep_string("publickey", methods
, methlen
);
3825 in_commasep_string("password", methods
, methlen
);
3827 in_commasep_string("keyboard-interactive", methods
, methlen
);
3832 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
3834 * Attempt public-key authentication using Pageant.
3836 static unsigned char request
[5], *response
, *p
;
3837 static int responselen
;
3838 static int i
, nkeys
;
3839 static int authed
= FALSE
;
3844 logevent("Pageant is running. Requesting keys.");
3846 /* Request the keys held by the agent. */
3847 PUT_32BIT(request
, 1);
3848 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
3849 agent_query(request
, 5, &r
, &responselen
);
3850 response
= (unsigned char *) r
;
3851 if (response
&& responselen
>= 5 &&
3852 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
3854 nkeys
= GET_32BIT(p
);
3858 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
3861 for (i
= 0; i
< nkeys
; i
++) {
3862 static char *pkblob
, *alg
, *commentp
;
3863 static int pklen
, alglen
, commentlen
;
3864 static int siglen
, retlen
, len
;
3865 static char *q
, *agentreq
, *ret
;
3870 sprintf(buf
, "Trying Pageant key #%d", i
);
3873 pklen
= GET_32BIT(p
);
3877 alglen
= GET_32BIT(pkblob
);
3879 commentlen
= GET_32BIT(p
);
3883 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3884 ssh2_pkt_addstring(username
);
3885 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3886 ssh2_pkt_addstring("publickey"); /* method */
3887 ssh2_pkt_addbool(FALSE
); /* no signature included */
3888 ssh2_pkt_addstring_start();
3889 ssh2_pkt_addstring_data(alg
, alglen
);
3890 ssh2_pkt_addstring_start();
3891 ssh2_pkt_addstring_data(pkblob
, pklen
);
3894 crWaitUntilV(ispkt
);
3895 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
3896 logevent("Key refused");
3900 if (flags
& FLAG_VERBOSE
) {
3902 ("Authenticating with public key \"");
3903 c_write(commentp
, commentlen
);
3904 c_write_str("\" from agent\r\n");
3908 * Server is willing to accept the key.
3909 * Construct a SIGN_REQUEST.
3911 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3912 ssh2_pkt_addstring(username
);
3913 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3914 ssh2_pkt_addstring("publickey"); /* method */
3915 ssh2_pkt_addbool(TRUE
);
3916 ssh2_pkt_addstring_start();
3917 ssh2_pkt_addstring_data(alg
, alglen
);
3918 ssh2_pkt_addstring_start();
3919 ssh2_pkt_addstring_data(pkblob
, pklen
);
3921 siglen
= pktout
.length
- 5 + 4 + 20;
3922 len
= 1; /* message type */
3923 len
+= 4 + pklen
; /* key blob */
3924 len
+= 4 + siglen
; /* data to sign */
3925 len
+= 4; /* flags */
3926 agentreq
= smalloc(4 + len
);
3927 PUT_32BIT(agentreq
, len
);
3929 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
3930 PUT_32BIT(q
, pklen
);
3932 memcpy(q
, pkblob
, pklen
);
3934 PUT_32BIT(q
, siglen
);
3936 /* Now the data to be signed... */
3939 memcpy(q
, ssh2_session_id
, 20);
3941 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
3942 q
+= pktout
.length
- 5;
3943 /* And finally the (zero) flags word. */
3945 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
3949 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
3950 logevent("Sending Pageant's response");
3951 ssh2_pkt_addstring_start();
3952 ssh2_pkt_addstring_data(ret
+ 9,
3960 ("Pageant failed to answer challenge");
3970 if (!method
&& can_pubkey
&& *cfg
.keyfile
3971 && !tried_pubkey_config
) {
3972 unsigned char *pub_blob
;
3973 char *algorithm
, *comment
;
3976 tried_pubkey_config
= TRUE
;
3979 * Try the public key supplied in the configuration.
3981 * First, offer the public blob to see if the server is
3982 * willing to accept it.
3984 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
3987 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3988 ssh2_pkt_addstring(username
);
3989 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3990 ssh2_pkt_addstring("publickey"); /* method */
3991 ssh2_pkt_addbool(FALSE
); /* no signature included */
3992 ssh2_pkt_addstring(algorithm
);
3993 ssh2_pkt_addstring_start();
3994 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
3996 logevent("Offered public key"); /* FIXME */
3998 crWaitUntilV(ispkt
);
3999 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4001 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4002 continue; /* key refused; give up on it */
4005 logevent("Offer of public key accepted");
4007 * Actually attempt a serious authentication using
4010 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4012 "Passphrase for key \"%.100s\": ",
4018 c_write_str("Authenticating with public key \"");
4019 c_write_str(comment
);
4020 c_write_str("\"\r\n");
4021 method
= AUTH_PUBLICKEY_FILE
;
4025 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4026 method
= AUTH_KEYBOARD_INTERACTIVE
;
4027 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4028 tried_keyb_inter
= TRUE
;
4030 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4031 ssh2_pkt_addstring(username
);
4032 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4033 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4034 ssh2_pkt_addstring(""); /* lang */
4035 ssh2_pkt_addstring("");
4038 crWaitUntilV(ispkt
);
4039 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4040 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4042 logevent("Keyboard-interactive authentication refused");
4043 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4047 kbd_inter_running
= TRUE
;
4050 if (kbd_inter_running
) {
4051 method
= AUTH_KEYBOARD_INTERACTIVE
;
4052 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4053 tried_keyb_inter
= TRUE
;
4055 /* We've got packet with that "interactive" info
4056 dump banners, and set its prompt as ours */
4058 char *name
, *inst
, *lang
, *prompt
;
4059 int name_len
, inst_len
, lang_len
, prompt_len
;
4060 ssh2_pkt_getstring(&name
, &name_len
);
4061 ssh2_pkt_getstring(&inst
, &inst_len
);
4062 ssh2_pkt_getstring(&lang
, &lang_len
);
4064 c_write_untrusted(name
, name_len
);
4066 c_write_untrusted(inst
, inst_len
);
4067 num_prompts
= ssh2_pkt_getuint32();
4069 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4070 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4073 echo
= ssh2_pkt_getbool();
4077 if (!method
&& can_passwd
) {
4078 method
= AUTH_PASSWORD
;
4079 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4086 if (!ssh_get_line(pwprompt
, password
,
4087 sizeof(password
), TRUE
)) {
4089 * get_line failed to get a password (for
4090 * example because one was supplied on the
4091 * command line which has already failed to
4094 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4095 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4097 ("No more passwords available to try");
4098 ssh2_pkt_addstring("en"); /* language tag */
4100 connection_fatal("Unable to authenticate");
4101 ssh_state
= SSH_STATE_CLOSED
;
4108 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4113 crWaitUntilV(!ispkt
);
4115 switch (c
= *in
++) {
4136 if (pos
< sizeof(password
)-1)
4137 password
[pos
++] = c
;
4141 c_write_str("\r\n");
4145 if (method
== AUTH_PUBLICKEY_FILE
) {
4147 * We have our passphrase. Now try the actual authentication.
4149 struct ssh2_userkey
*key
;
4151 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4152 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4153 if (key
== SSH2_WRONG_PASSPHRASE
) {
4154 c_write_str("Wrong passphrase\r\n");
4155 tried_pubkey_config
= FALSE
;
4157 c_write_str("Unable to load private key\r\n");
4158 tried_pubkey_config
= TRUE
;
4160 /* Send a spurious AUTH_NONE to return to the top. */
4161 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4162 ssh2_pkt_addstring(username
);
4163 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4164 ssh2_pkt_addstring("none"); /* method */
4166 type
= AUTH_TYPE_NONE
;
4168 unsigned char *blob
, *sigdata
;
4169 int blob_len
, sigdata_len
;
4172 * We have loaded the private key and the server
4173 * has announced that it's willing to accept it.
4174 * Hallelujah. Generate a signature and send it.
4176 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4177 ssh2_pkt_addstring(username
);
4178 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4179 ssh2_pkt_addstring("publickey"); /* method */
4180 ssh2_pkt_addbool(TRUE
);
4181 ssh2_pkt_addstring(key
->alg
->name
);
4182 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4183 ssh2_pkt_addstring_start();
4184 ssh2_pkt_addstring_data(blob
, blob_len
);
4188 * The data to be signed is:
4192 * followed by everything so far placed in the
4195 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4196 sigdata
= smalloc(sigdata_len
);
4197 PUT_32BIT(sigdata
, 20);
4198 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4199 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4202 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4204 ssh2_pkt_addstring_start();
4205 ssh2_pkt_addstring_data(blob
, blob_len
);
4210 type
= AUTH_TYPE_PUBLICKEY
;
4212 } else if (method
== AUTH_PASSWORD
) {
4214 * We send the password packet lumped tightly together with
4215 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4216 * string long enough to make the total length of the two
4217 * packets constant. This should ensure that a passive
4218 * listener doing traffic analyis can't work out the length
4221 * For this to work, we need an assumption about the
4222 * maximum length of the password packet. I think 256 is
4223 * pretty conservative. Anyone using a password longer than
4224 * that probably doesn't have much to worry about from
4225 * people who find out how long their password is!
4227 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4228 ssh2_pkt_addstring(username
);
4229 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4230 ssh2_pkt_addstring("password");
4231 ssh2_pkt_addbool(FALSE
);
4232 ssh2_pkt_addstring(password
);
4235 * We'll include a string that's an exact multiple of the
4236 * cipher block size. If the cipher is NULL for some
4237 * reason, we don't do this trick at all because we gain
4243 stringlen
= (256 - deferred_len
);
4244 stringlen
+= cscipher
->blksize
- 1;
4245 stringlen
-= (stringlen
% cscipher
->blksize
);
4248 * Temporarily disable actual compression,
4249 * so we can guarantee to get this string
4250 * exactly the length we want it. The
4251 * compression-disabling routine should
4252 * return an integer indicating how many
4253 * bytes we should adjust our string length
4256 stringlen
-= cscomp
->disable_compression();
4258 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4259 ssh2_pkt_addstring_start();
4260 for (i
= 0; i
< stringlen
; i
++) {
4261 char c
= (char) random_byte();
4262 ssh2_pkt_addstring_data(&c
, 1);
4266 ssh_pkt_defersend();
4267 logevent("Sent password");
4268 type
= AUTH_TYPE_PASSWORD
;
4269 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4270 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4271 ssh2_pkt_adduint32(num_prompts
);
4272 ssh2_pkt_addstring(password
);
4273 memset(password
, 0, sizeof(password
));
4275 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4278 ("No supported authentication methods left to try!\r\n");
4280 ("No supported authentications offered. Disconnecting");
4281 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4282 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4284 ("No supported authentication methods available");
4285 ssh2_pkt_addstring("en"); /* language tag */
4287 ssh_state
= SSH_STATE_CLOSED
;
4291 } while (!we_are_in
);
4294 * Now we're authenticated for the connection protocol. The
4295 * connection protocol will automatically have started at this
4296 * point; there's no need to send SERVICE_REQUEST.
4300 * So now create a channel with a session in it.
4302 ssh_channels
= newtree234(ssh_channelcmp
);
4303 mainchan
= smalloc(sizeof(struct ssh_channel
));
4304 mainchan
->localid
= alloc_channel_id();
4305 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4306 ssh2_pkt_addstring("session");
4307 ssh2_pkt_adduint32(mainchan
->localid
);
4308 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4309 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4310 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4312 crWaitUntilV(ispkt
);
4313 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4314 bombout(("Server refused to open a session"));
4316 /* FIXME: error data comes back in FAILURE packet */
4318 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4319 bombout(("Server's channel confirmation cited wrong channel"));
4322 mainchan
->remoteid
= ssh2_pkt_getuint32();
4323 mainchan
->type
= CHAN_MAINSESSION
;
4324 mainchan
->closes
= 0;
4325 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4326 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4327 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4328 add234(ssh_channels
, mainchan
);
4329 logevent("Opened channel for session");
4332 * Potentially enable X11 forwarding.
4334 if (cfg
.x11_forward
) {
4335 char proto
[20], data
[64];
4336 logevent("Requesting X11 forwarding");
4337 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4338 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4339 ssh2_pkt_adduint32(mainchan
->remoteid
);
4340 ssh2_pkt_addstring("x11-req");
4341 ssh2_pkt_addbool(1); /* want reply */
4342 ssh2_pkt_addbool(0); /* many connections */
4343 ssh2_pkt_addstring(proto
);
4344 ssh2_pkt_addstring(data
);
4345 ssh2_pkt_adduint32(0); /* screen number */
4349 crWaitUntilV(ispkt
);
4350 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4351 unsigned i
= ssh2_pkt_getuint32();
4352 struct ssh_channel
*c
;
4353 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4355 continue; /* nonexistent channel */
4356 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4358 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4360 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4361 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4362 bombout(("Server got confused by X11 forwarding request"));
4365 logevent("X11 forwarding refused");
4367 logevent("X11 forwarding enabled");
4368 ssh_X11_fwd_enabled
= TRUE
;
4373 * Enable port forwardings.
4376 static char *e
; /* preserve across crReturn */
4380 char sports
[256], dports
[256], host
[256];
4383 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4384 /* Add port forwardings. */
4389 while (*e
&& *e
!= '\t')
4395 while (*e
&& *e
!= ':')
4405 dport
= atoi(dports
);
4406 sport
= atoi(sports
);
4407 if (sport
&& dport
) {
4409 pfd_addforward(host
, dport
, sport
);
4410 sprintf(buf
, "Local port %d forwarding to %s:%d",
4411 sport
, host
, dport
);
4414 struct ssh_rportfwd
*pf
;
4415 pf
= smalloc(sizeof(*pf
));
4416 strcpy(pf
->dhost
, host
);
4419 if (add234(ssh_rportfwds
, pf
) != pf
) {
4421 "Duplicate remote port forwarding to %s:%d",
4426 sprintf(buf
, "Requesting remote port %d (forwarded to %s:%d)",
4427 sport
, host
, dport
);
4429 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4430 ssh2_pkt_addstring("tcpip-forward");
4431 ssh2_pkt_addbool(1);/* want reply */
4432 ssh2_pkt_addstring("127.0.0.1");
4433 ssh2_pkt_adduint32(sport
);
4437 crWaitUntilV(ispkt
);
4438 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4439 unsigned i
= ssh2_pkt_getuint32();
4440 struct ssh_channel
*c
;
4441 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4443 continue;/* nonexistent channel */
4444 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4446 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4448 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4449 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4450 bombout(("Server got confused by port forwarding request"));
4453 logevent("Server refused this port forwarding");
4455 logevent("Remote port forwarding enabled");
4464 * Potentially enable agent forwarding.
4466 if (cfg
.agentfwd
&& agent_exists()) {
4467 logevent("Requesting OpenSSH-style agent forwarding");
4468 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4469 ssh2_pkt_adduint32(mainchan
->remoteid
);
4470 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4471 ssh2_pkt_addbool(1); /* want reply */
4475 crWaitUntilV(ispkt
);
4476 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4477 unsigned i
= ssh2_pkt_getuint32();
4478 struct ssh_channel
*c
;
4479 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4481 continue; /* nonexistent channel */
4482 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4484 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4486 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4487 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4489 ("Server got confused by agent forwarding request"));
4492 logevent("Agent forwarding refused");
4494 logevent("Agent forwarding enabled");
4495 ssh_agentfwd_enabled
= TRUE
;
4500 * Now allocate a pty for the session.
4503 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4504 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4505 ssh2_pkt_addstring("pty-req");
4506 ssh2_pkt_addbool(1); /* want reply */
4507 ssh2_pkt_addstring(cfg
.termtype
);
4508 ssh2_pkt_adduint32(cols
);
4509 ssh2_pkt_adduint32(rows
);
4510 ssh2_pkt_adduint32(0); /* pixel width */
4511 ssh2_pkt_adduint32(0); /* pixel height */
4512 ssh2_pkt_addstring_start();
4513 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4515 ssh_state
= SSH_STATE_INTERMED
;
4518 crWaitUntilV(ispkt
);
4519 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4520 unsigned i
= ssh2_pkt_getuint32();
4521 struct ssh_channel
*c
;
4522 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4524 continue; /* nonexistent channel */
4525 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4527 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4529 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4530 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4531 bombout(("Server got confused by pty request"));
4534 c_write_str("Server refused to allocate pty\r\n");
4535 ssh_editing
= ssh_echoing
= 1;
4537 logevent("Allocated pty");
4540 ssh_editing
= ssh_echoing
= 1;
4544 * Start a shell or a remote command. We may have to attempt
4545 * this twice if the config data has provided a second choice
4552 if (ssh_fallback_cmd
) {
4553 subsys
= cfg
.ssh_subsys2
;
4554 cmd
= cfg
.remote_cmd_ptr2
;
4556 subsys
= cfg
.ssh_subsys
;
4557 cmd
= cfg
.remote_cmd_ptr
;
4560 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4561 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4563 ssh2_pkt_addstring("subsystem");
4564 ssh2_pkt_addbool(1); /* want reply */
4565 ssh2_pkt_addstring(cmd
);
4567 ssh2_pkt_addstring("exec");
4568 ssh2_pkt_addbool(1); /* want reply */
4569 ssh2_pkt_addstring(cmd
);
4571 ssh2_pkt_addstring("shell");
4572 ssh2_pkt_addbool(1); /* want reply */
4576 crWaitUntilV(ispkt
);
4577 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4578 unsigned i
= ssh2_pkt_getuint32();
4579 struct ssh_channel
*c
;
4580 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4582 continue; /* nonexistent channel */
4583 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4585 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4586 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4587 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4588 bombout(("Server got confused by shell/command request"));
4592 * We failed to start the command. If this is the
4593 * fallback command, we really are finished; if it's
4594 * not, and if the fallback command exists, try falling
4595 * back to it before complaining.
4597 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
4598 logevent("Primary command failed; attempting fallback");
4599 ssh_fallback_cmd
= TRUE
;
4602 bombout(("Server refused to start a shell/command"));
4605 logevent("Started a shell/command");
4610 ssh_state
= SSH_STATE_SESSION
;
4614 ssh_special(TS_EOF
);
4619 ldisc_send(NULL
, 0); /* cause ldisc to notice changes */
4622 static int try_send
;
4626 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
4627 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
4630 unsigned i
= ssh2_pkt_getuint32();
4631 struct ssh_channel
*c
;
4632 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4634 continue; /* nonexistent channel */
4635 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
4636 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
4637 continue; /* extended but not stderr */
4638 ssh2_pkt_getstring(&data
, &length
);
4641 c
->v
.v2
.locwindow
-= length
;
4643 case CHAN_MAINSESSION
:
4645 from_backend(pktin
.type
==
4646 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
4650 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
4653 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
4656 while (length
> 0) {
4657 if (c
->u
.a
.lensofar
< 4) {
4658 int l
= min(4 - c
->u
.a
.lensofar
, length
);
4659 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
4663 c
->u
.a
.lensofar
+= l
;
4665 if (c
->u
.a
.lensofar
== 4) {
4667 4 + GET_32BIT(c
->u
.a
.msglen
);
4668 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
4669 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
4671 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
4673 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
4675 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
4679 c
->u
.a
.lensofar
+= l
;
4681 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
4682 void *reply
, *sentreply
;
4684 agent_query(c
->u
.a
.message
,
4685 c
->u
.a
.totallen
, &reply
,
4690 /* Fake SSH_AGENT_FAILURE. */
4691 sentreply
= "\0\0\0\1\5";
4694 ssh2_add_channel_data(c
, sentreply
,
4699 sfree(c
->u
.a
.message
);
4700 c
->u
.a
.lensofar
= 0;
4707 * If we are not buffering too much data,
4708 * enlarge the window again at the remote side.
4710 if (bufsize
< OUR_V2_WINSIZE
)
4711 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
4713 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
4714 ssh_state
= SSH_STATE_CLOSED
;
4715 logevent("Received disconnect message");
4717 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
4718 continue; /* exit status et al; ignore (FIXME?) */
4719 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
4720 unsigned i
= ssh2_pkt_getuint32();
4721 struct ssh_channel
*c
;
4723 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4725 continue; /* nonexistent channel */
4727 if (c
->type
== CHAN_X11
) {
4729 * Remote EOF on an X11 channel means we should
4730 * wrap up and close the channel ourselves.
4732 x11_close(c
->u
.x11
.s
);
4734 } else if (c
->type
== CHAN_AGENT
) {
4736 } else if (c
->type
== CHAN_SOCKDATA
) {
4737 pfd_close(c
->u
.pfd
.s
);
4740 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
4741 unsigned i
= ssh2_pkt_getuint32();
4742 struct ssh_channel
*c
;
4744 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4746 continue; /* nonexistent channel */
4747 /* Do pre-close processing on the channel. */
4749 case CHAN_MAINSESSION
:
4750 break; /* nothing to see here, move along */
4752 if (c
->u
.x11
.s
!= NULL
)
4753 x11_close(c
->u
.x11
.s
);
4760 if (c
->u
.pfd
.s
!= NULL
)
4761 pfd_close(c
->u
.pfd
.s
);
4765 if (c
->closes
== 0) {
4766 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4767 ssh2_pkt_adduint32(c
->remoteid
);
4770 del234(ssh_channels
, c
);
4771 bufchain_clear(&c
->v
.v2
.outbuffer
);
4775 * See if that was the last channel left open.
4777 if (count234(ssh_channels
) == 0) {
4778 logevent("All channels closed. Disconnecting");
4779 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4780 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4781 ssh2_pkt_addstring("All open channels closed");
4782 ssh2_pkt_addstring("en"); /* language tag */
4784 ssh_state
= SSH_STATE_CLOSED
;
4787 continue; /* remote sends close; ignore (FIXME) */
4788 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4789 unsigned i
= ssh2_pkt_getuint32();
4790 struct ssh_channel
*c
;
4791 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4793 continue; /* nonexistent channel */
4794 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4796 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4797 unsigned i
= ssh2_pkt_getuint32();
4798 struct ssh_channel
*c
;
4799 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4801 continue; /* nonexistent channel */
4802 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4803 continue; /* dunno why they're confirming this */
4804 c
->remoteid
= ssh2_pkt_getuint32();
4805 c
->type
= CHAN_SOCKDATA
;
4807 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4808 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4809 bufchain_init(&c
->v
.v2
.outbuffer
);
4810 pfd_confirm(c
->u
.pfd
.s
);
4811 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
4812 unsigned i
= ssh2_pkt_getuint32();
4813 struct ssh_channel
*c
;
4814 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4816 continue; /* nonexistent channel */
4817 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4818 continue; /* dunno why they're failing this */
4820 logevent("Forwarded connection refused by server");
4822 pfd_close(c
->u
.pfd
.s
);
4824 del234(ssh_channels
, c
);
4826 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
4830 struct ssh_channel
*c
;
4831 unsigned remid
, winsize
, pktsize
;
4832 ssh2_pkt_getstring(&type
, &typelen
);
4833 c
= smalloc(sizeof(struct ssh_channel
));
4835 remid
= ssh2_pkt_getuint32();
4836 winsize
= ssh2_pkt_getuint32();
4837 pktsize
= ssh2_pkt_getuint32();
4839 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
4840 if (!ssh_X11_fwd_enabled
)
4841 error
= "X11 forwarding is not enabled";
4842 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
4844 error
= "Unable to open an X11 connection";
4848 } else if (typelen
== 15 &&
4849 !memcmp(type
, "forwarded-tcpip", 15)) {
4850 struct ssh_rportfwd pf
, *realpf
;
4853 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
4854 pf
.sport
= ssh2_pkt_getuint32();
4855 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
4856 if (realpf
== NULL
) {
4857 error
= "Remote port is not recognised";
4859 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
4862 sprintf(buf
, "Received remote port open request for %s:%d",
4863 realpf
->dhost
, realpf
->dport
);
4866 sprintf(buf
, "Port open failed: %s", e
);
4868 error
= "Port open failed";
4870 logevent("Forwarded port opened successfully");
4871 c
->type
= CHAN_SOCKDATA
;
4874 } else if (typelen
== 22 &&
4875 !memcmp(type
, "auth-agent@openssh.com", 3)) {
4876 if (!ssh_agentfwd_enabled
)
4877 error
= "Agent forwarding is not enabled";
4879 c
->type
= CHAN_AGENT
; /* identify channel type */
4880 c
->u
.a
.lensofar
= 0;
4883 error
= "Unsupported channel type requested";
4886 c
->remoteid
= remid
;
4888 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
4889 ssh2_pkt_adduint32(c
->remoteid
);
4890 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
4891 ssh2_pkt_addstring(error
);
4892 ssh2_pkt_addstring("en"); /* language tag */
4896 c
->localid
= alloc_channel_id();
4898 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4899 c
->v
.v2
.remwindow
= winsize
;
4900 c
->v
.v2
.remmaxpkt
= pktsize
;
4901 bufchain_init(&c
->v
.v2
.outbuffer
);
4902 add234(ssh_channels
, c
);
4903 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
4904 ssh2_pkt_adduint32(c
->remoteid
);
4905 ssh2_pkt_adduint32(c
->localid
);
4906 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
4907 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4911 bombout(("Strange packet received: type %d", pktin
.type
));
4916 * We have spare data. Add it to the channel buffer.
4918 ssh2_add_channel_data(mainchan
, in
, inlen
);
4923 struct ssh_channel
*c
;
4925 * Try to send data on all channels if we can.
4927 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
4928 int bufsize
= ssh2_try_send(c
);
4931 case CHAN_MAINSESSION
:
4932 /* stdin need not receive an unthrottle
4933 * notification since it will be polled */
4936 x11_unthrottle(c
->u
.x11
.s
);
4939 /* agent sockets are request/response and need no
4940 * buffer management */
4943 pfd_unthrottle(c
->u
.pfd
.s
);
4955 * Handle the top-level SSH2 protocol.
4957 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
4959 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
4961 do_ssh2_authconn(in
, inlen
, ispkt
);
4965 * Called to set up the connection.
4967 * Returns an error message, or NULL on success.
4969 static char *ssh_init(char *host
, int port
, char **realhost
)
4974 if (crypto_startup() == 0)
4975 return "Microsoft high encryption pack not installed!";
4981 ssh1_throttle_count
= 0;
4982 ssh_overall_bufsize
= 0;
4983 ssh_fallback_cmd
= 0;
4985 p
= connect_to_host(host
, port
, realhost
);
4993 * Called to send data down the Telnet connection.
4995 static int ssh_send(char *buf
, int len
)
4997 if (s
== NULL
|| ssh_protocol
== NULL
)
5000 ssh_protocol(buf
, len
, 0);
5002 return ssh_sendbuffer();
5006 * Called to query the current amount of buffered stdin data.
5008 static int ssh_sendbuffer(void)
5012 if (s
== NULL
|| ssh_protocol
== NULL
)
5016 * If the SSH socket itself has backed up, add the total backup
5017 * size on that to any individual buffer on the stdin channel.
5020 if (ssh_throttled_all
)
5021 override_value
= ssh_overall_bufsize
;
5023 if (ssh_version
== 1) {
5024 return override_value
;
5025 } else if (ssh_version
== 2) {
5026 if (!mainchan
|| mainchan
->closes
> 0)
5027 return override_value
;
5029 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5036 * Called to set the size of the window from SSH's POV.
5038 static void ssh_size(void)
5040 switch (ssh_state
) {
5041 case SSH_STATE_BEFORE_SIZE
:
5042 case SSH_STATE_PREPACKET
:
5043 case SSH_STATE_CLOSED
:
5044 break; /* do nothing */
5045 case SSH_STATE_INTERMED
:
5046 size_needed
= TRUE
; /* buffer for later */
5048 case SSH_STATE_SESSION
:
5050 if (ssh_version
== 1) {
5051 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5052 PKT_INT
, rows
, PKT_INT
, cols
,
5053 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5055 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5056 ssh2_pkt_adduint32(mainchan
->remoteid
);
5057 ssh2_pkt_addstring("window-change");
5058 ssh2_pkt_addbool(0);
5059 ssh2_pkt_adduint32(cols
);
5060 ssh2_pkt_adduint32(rows
);
5061 ssh2_pkt_adduint32(0);
5062 ssh2_pkt_adduint32(0);
5071 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5072 * can send an EOF and collect resulting output (e.g. `plink
5075 static void ssh_special(Telnet_Special code
)
5077 if (code
== TS_EOF
) {
5078 if (ssh_state
!= SSH_STATE_SESSION
) {
5080 * Buffer the EOF in case we are pre-SESSION, so we can
5081 * send it as soon as we reach SESSION.
5087 if (ssh_version
== 1) {
5088 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5090 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5091 ssh2_pkt_adduint32(mainchan
->remoteid
);
5094 logevent("Sent EOF message");
5095 } else if (code
== TS_PING
) {
5096 if (ssh_state
== SSH_STATE_CLOSED
5097 || ssh_state
== SSH_STATE_PREPACKET
) return;
5098 if (ssh_version
== 1) {
5099 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5101 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5102 ssh2_pkt_addstring_start();
5110 void *new_sock_channel(Socket s
)
5112 struct ssh_channel
*c
;
5113 c
= smalloc(sizeof(struct ssh_channel
));
5116 c
->remoteid
= -1; /* to be set when open confirmed */
5117 c
->localid
= alloc_channel_id();
5119 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5121 add234(ssh_channels
, c
);
5127 * This is called when stdout/stderr (the entity to which
5128 * from_backend sends data) manages to clear some backlog.
5130 void ssh_unthrottle(int bufsize
)
5132 if (ssh_version
== 1) {
5133 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5134 ssh1_stdout_throttling
= 0;
5138 if (mainchan
&& mainchan
->closes
== 0)
5139 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5143 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5145 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5148 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5151 if (ssh_version
== 1) {
5152 send_packet(SSH1_MSG_PORT_OPEN
,
5153 PKT_INT
, c
->localid
,
5156 //PKT_STR, <org:orgport>,
5159 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5160 ssh2_pkt_addstring("direct-tcpip");
5161 ssh2_pkt_adduint32(c
->localid
);
5162 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5163 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5164 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5165 ssh2_pkt_addstring(hostname
);
5166 ssh2_pkt_adduint32(port
);
5168 * We make up values for the originator data; partly it's
5169 * too much hassle to keep track, and partly I'm not
5170 * convinced the server should be told details like that
5171 * about my local network configuration.
5173 ssh2_pkt_addstring("client-side-connection");
5174 ssh2_pkt_adduint32(0);
5180 static Socket
ssh_socket(void)
5185 static int ssh_sendok(void)
5190 static int ssh_ldisc(int option
)
5192 if (option
== LD_ECHO
)
5194 if (option
== LD_EDIT
)
5199 Backend ssh_backend
= {