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
));
735 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
737 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
745 st
->cipherblk
= sccipher
->blksize
;
748 if (st
->cipherblk
< 8)
751 if (pktin
.maxlen
< st
->cipherblk
) {
752 pktin
.maxlen
= st
->cipherblk
;
755 NULL ?
smalloc(st
->cipherblk
+
756 APIEXTRA
) : srealloc(pktin
.data
,
760 fatalbox("Out of memory");
764 * Acquire and decrypt the first block of the packet. This will
765 * contain the length and padding details.
767 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
768 while ((*datalen
) == 0)
769 crReturn(st
->cipherblk
- st
->i
);
770 pktin
.data
[st
->i
] = *(*data
)++;
774 if (!memcmp(pktin
.data
, "Remo", 4)) { /* "Remo"te server has closed ... */
779 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
782 * Now get the length and padding figures.
784 st
->len
= GET_32BIT(pktin
.data
);
785 st
->pad
= pktin
.data
[4];
788 * This enables us to deduce the payload length.
790 st
->payload
= st
->len
- st
->pad
- 1;
792 pktin
.length
= st
->payload
+ 5;
795 * So now we can work out the total packet length.
797 st
->packetlen
= st
->len
+ 4;
798 st
->maclen
= scmac ? scmac
->len
: 0;
801 * Adjust memory allocation if packet is too big.
803 if (pktin
.maxlen
< st
->packetlen
+ st
->maclen
) {
804 pktin
.maxlen
= st
->packetlen
+ st
->maclen
;
807 NULL ?
smalloc(pktin
.maxlen
+ APIEXTRA
) : srealloc(pktin
.data
,
812 fatalbox("Out of memory");
816 * Read and decrypt the remainder of the packet.
818 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
;
820 while ((*datalen
) == 0)
821 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
822 pktin
.data
[st
->i
] = *(*data
)++;
825 /* Decrypt everything _except_ the MAC. */
827 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
828 st
->packetlen
- st
->cipherblk
);
831 debug(("Got packet len=%d pad=%d\n", st
->len
, st
->pad
));
832 dmemdump(pktin
.data
, st
->packetlen
);
839 && !scmac
->verify(pktin
.data
, st
->len
+ 4,
840 st
->incoming_sequence
)) {
841 bombout(("Incorrect MAC received on packet"));
844 st
->incoming_sequence
++; /* whether or not we MACed */
847 * Decompress packet payload.
850 unsigned char *newpayload
;
852 if (sccomp
&& sccomp
->decompress(pktin
.data
+ 5, pktin
.length
- 5,
853 &newpayload
, &newlen
)) {
854 if (pktin
.maxlen
< newlen
+ 5) {
855 pktin
.maxlen
= newlen
+ 5;
858 NULL ?
smalloc(pktin
.maxlen
+
859 APIEXTRA
) : srealloc(pktin
.data
,
863 fatalbox("Out of memory");
865 pktin
.length
= 5 + newlen
;
866 memcpy(pktin
.data
+ 5, newpayload
, newlen
);
868 debug(("Post-decompression payload:\n"));
869 dmemdump(pktin
.data
+ 5, newlen
);
877 pktin
.type
= pktin
.data
[5];
879 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
880 goto next_packet
; /* FIXME: print DEBUG message */
882 if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
883 /* log reason code in disconnect message */
885 int reason
= GET_32BIT(pktin
.data
+ 6);
886 unsigned msglen
= GET_32BIT(pktin
.data
+ 10);
888 if (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) {
889 sprintf(buf
, "Received disconnect message (%s)",
890 ssh2_disconnect_reasons
[reason
]);
892 sprintf(buf
, "Received disconnect message (unknown type %d)",
896 strcpy(buf
, "Disconnection message text: ");
897 nowlen
= strlen(buf
);
898 if (msglen
> sizeof(buf
) - nowlen
- 1)
899 msglen
= sizeof(buf
) - nowlen
- 1;
900 memcpy(buf
+ nowlen
, pktin
.data
+ 14, msglen
);
901 buf
[nowlen
+ msglen
] = '\0';
903 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
905 (reason
> 0 && reason
< lenof(ssh2_disconnect_reasons
)) ?
906 ssh2_disconnect_reasons
[reason
] : "unknown",
914 static void ssh1_pktout_size(int len
)
918 len
+= 5; /* type and CRC */
922 pktout
.length
= len
- 5;
923 if (pktout
.maxlen
< biglen
) {
924 pktout
.maxlen
= biglen
;
926 /* Allocate enough buffer space for extra block
927 * for MS CryptEncrypt() */
928 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 12) :
929 srealloc(pktout
.data
, biglen
+ 12));
931 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+ 4) :
932 srealloc(pktout
.data
, biglen
+ 4));
935 fatalbox("Out of memory");
937 pktout
.body
= pktout
.data
+ 4 + pad
+ 1;
940 static void s_wrpkt_start(int type
, int len
)
942 ssh1_pktout_size(len
);
946 static int s_wrpkt_prepare(void)
948 int pad
, len
, biglen
, i
;
951 pktout
.body
[-1] = pktout
.type
;
954 debug(("Packet payload pre-compression:\n"));
955 dmemdump(pktout
.body
- 1, pktout
.length
+ 1);
958 if (ssh1_compressing
) {
959 unsigned char *compblk
;
961 zlib_compress_block(pktout
.body
- 1, pktout
.length
+ 1,
963 ssh1_pktout_size(complen
- 1);
964 memcpy(pktout
.body
- 1, compblk
, complen
);
967 debug(("Packet payload post-compression:\n"));
968 dmemdump(pktout
.body
- 1, pktout
.length
+ 1);
972 len
= pktout
.length
+ 5; /* type and CRC */
976 for (i
= 0; i
< pad
; i
++)
977 pktout
.data
[i
+ 4] = random_byte();
978 crc
= crc32(pktout
.data
+ 4, biglen
- 4);
979 PUT_32BIT(pktout
.data
+ biglen
, crc
);
980 PUT_32BIT(pktout
.data
, len
);
983 debug(("Sending packet len=%d\n", biglen
+ 4));
984 dmemdump(pktout
.data
, biglen
+ 4);
987 cipher
->encrypt(pktout
.data
+ 4, biglen
);
992 static void s_wrpkt(void)
995 len
= s_wrpkt_prepare();
996 backlog
= sk_write(s
, pktout
.data
, len
);
997 if (backlog
> SSH_MAX_BACKLOG
)
998 ssh_throttle_all(1, backlog
);
1001 static void s_wrpkt_defer(void)
1004 len
= s_wrpkt_prepare();
1005 if (deferred_len
+ len
> deferred_size
) {
1006 deferred_size
= deferred_len
+ len
+ 128;
1007 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1009 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1010 deferred_len
+= len
;
1014 * Construct a packet with the specified contents.
1016 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
1018 unsigned char *p
, *argp
, argchar
;
1019 unsigned long argint
;
1020 int pktlen
, argtype
, arglen
;
1024 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
1027 (void) va_arg(ap1
, int);
1031 (void) va_arg(ap1
, char);
1035 (void) va_arg(ap1
, unsigned char *);
1036 arglen
= va_arg(ap1
, int);
1040 argp
= va_arg(ap1
, unsigned char *);
1041 arglen
= strlen(argp
);
1042 pktlen
+= 4 + arglen
;
1045 bn
= va_arg(ap1
, Bignum
);
1046 pktlen
+= ssh1_bignum_length(bn
);
1053 s_wrpkt_start(pkttype
, pktlen
);
1056 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
1059 argint
= va_arg(ap2
, int);
1060 PUT_32BIT(p
, argint
);
1064 argchar
= va_arg(ap2
, unsigned char);
1069 argp
= va_arg(ap2
, unsigned char *);
1070 arglen
= va_arg(ap2
, int);
1071 memcpy(p
, argp
, arglen
);
1075 argp
= va_arg(ap2
, unsigned char *);
1076 arglen
= strlen(argp
);
1077 PUT_32BIT(p
, arglen
);
1078 memcpy(p
+ 4, argp
, arglen
);
1082 bn
= va_arg(ap2
, Bignum
);
1083 p
+= ssh1_write_bignum(p
, bn
);
1089 static void send_packet(int pkttype
, ...)
1092 va_start(ap1
, pkttype
);
1093 va_start(ap2
, pkttype
);
1094 construct_packet(pkttype
, ap1
, ap2
);
1098 static void defer_packet(int pkttype
, ...)
1101 va_start(ap1
, pkttype
);
1102 va_start(ap2
, pkttype
);
1103 construct_packet(pkttype
, ap1
, ap2
);
1107 static int ssh_versioncmp(char *a
, char *b
)
1110 unsigned long av
, bv
;
1112 av
= strtoul(a
, &ae
, 10);
1113 bv
= strtoul(b
, &be
, 10);
1115 return (av
< bv ?
-1 : +1);
1120 av
= strtoul(ae
, &ae
, 10);
1121 bv
= strtoul(be
, &be
, 10);
1123 return (av
< bv ?
-1 : +1);
1129 * Utility routines for putting an SSH-protocol `string' and
1130 * `uint32' into a SHA state.
1133 static void sha_string(SHA_State
* s
, void *str
, int len
)
1135 unsigned char lenblk
[4];
1136 PUT_32BIT(lenblk
, len
);
1137 SHA_Bytes(s
, lenblk
, 4);
1138 SHA_Bytes(s
, str
, len
);
1141 static void sha_uint32(SHA_State
* s
, unsigned i
)
1143 unsigned char intblk
[4];
1144 PUT_32BIT(intblk
, i
);
1145 SHA_Bytes(s
, intblk
, 4);
1149 * SSH2 packet construction functions.
1151 static void ssh2_pkt_ensure(int length
)
1153 if (pktout
.maxlen
< length
) {
1154 pktout
.maxlen
= length
+ 256;
1157 NULL ?
smalloc(pktout
.maxlen
+
1158 APIEXTRA
) : srealloc(pktout
.data
,
1162 fatalbox("Out of memory");
1165 static void ssh2_pkt_adddata(void *data
, int len
)
1167 pktout
.length
+= len
;
1168 ssh2_pkt_ensure(pktout
.length
);
1169 memcpy(pktout
.data
+ pktout
.length
- len
, data
, len
);
1171 static void ssh2_pkt_addbyte(unsigned char byte
)
1173 ssh2_pkt_adddata(&byte
, 1);
1175 static void ssh2_pkt_init(int pkt_type
)
1178 ssh2_pkt_addbyte((unsigned char) pkt_type
);
1180 static void ssh2_pkt_addbool(unsigned char value
)
1182 ssh2_pkt_adddata(&value
, 1);
1184 static void ssh2_pkt_adduint32(unsigned long value
)
1187 PUT_32BIT(x
, value
);
1188 ssh2_pkt_adddata(x
, 4);
1190 static void ssh2_pkt_addstring_start(void)
1192 ssh2_pkt_adduint32(0);
1193 pktout
.savedpos
= pktout
.length
;
1195 static void ssh2_pkt_addstring_str(char *data
)
1197 ssh2_pkt_adddata(data
, strlen(data
));
1198 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1199 pktout
.length
- pktout
.savedpos
);
1201 static void ssh2_pkt_addstring_data(char *data
, int len
)
1203 ssh2_pkt_adddata(data
, len
);
1204 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
1205 pktout
.length
- pktout
.savedpos
);
1207 static void ssh2_pkt_addstring(char *data
)
1209 ssh2_pkt_addstring_start();
1210 ssh2_pkt_addstring_str(data
);
1212 static char *ssh2_mpint_fmt(Bignum b
, int *len
)
1215 int i
, n
= (bignum_bitcount(b
) + 7) / 8;
1218 fatalbox("out of memory");
1220 for (i
= 1; i
<= n
; i
++)
1221 p
[i
] = bignum_byte(b
, n
- i
);
1223 while (i
<= n
&& p
[i
] == 0 && (p
[i
+ 1] & 0x80) == 0)
1225 memmove(p
, p
+ i
, n
+ 1 - i
);
1229 static void ssh2_pkt_addmp(Bignum b
)
1233 p
= ssh2_mpint_fmt(b
, &len
);
1234 ssh2_pkt_addstring_start();
1235 ssh2_pkt_addstring_data(p
, len
);
1240 * Construct an SSH2 final-form packet: compress it, encrypt it,
1241 * put the MAC on it. Final packet, ready to be sent, is stored in
1242 * pktout.data. Total length is returned.
1244 static int ssh2_pkt_construct(void)
1246 int cipherblk
, maclen
, padding
, i
;
1247 static unsigned long outgoing_sequence
= 0;
1250 * Compress packet payload.
1253 debug(("Pre-compression payload:\n"));
1254 dmemdump(pktout
.data
+ 5, pktout
.length
- 5);
1257 unsigned char *newpayload
;
1259 if (cscomp
&& cscomp
->compress(pktout
.data
+ 5, pktout
.length
- 5,
1260 &newpayload
, &newlen
)) {
1262 ssh2_pkt_adddata(newpayload
, newlen
);
1268 * Add padding. At least four bytes, and must also bring total
1269 * length (minus MAC) up to a multiple of the block size.
1271 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
1272 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
1275 (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
1276 maclen
= csmac ? csmac
->len
: 0;
1277 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
1278 pktout
.data
[4] = padding
;
1279 for (i
= 0; i
< padding
; i
++)
1280 pktout
.data
[pktout
.length
+ i
] = random_byte();
1281 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
1283 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
1285 outgoing_sequence
++; /* whether or not we MACed */
1288 debug(("Sending packet len=%d\n", pktout
.length
+ padding
));
1289 dmemdump(pktout
.data
, pktout
.length
+ padding
);
1293 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
1295 /* Ready-to-send packet starts at pktout.data. We return length. */
1296 return pktout
.length
+ padding
+ maclen
;
1300 * Construct and send an SSH2 packet immediately.
1302 static void ssh2_pkt_send(void)
1306 len
= ssh2_pkt_construct();
1307 backlog
= sk_write(s
, pktout
.data
, len
);
1308 if (backlog
> SSH_MAX_BACKLOG
)
1309 ssh_throttle_all(1, backlog
);
1313 * Construct an SSH2 packet and add it to a deferred data block.
1314 * Useful for sending multiple packets in a single sk_write() call,
1315 * to prevent a traffic-analysing listener from being able to work
1316 * out the length of any particular packet (such as the password
1319 * Note that because SSH2 sequence-numbers its packets, this can
1320 * NOT be used as an m4-style `defer' allowing packets to be
1321 * constructed in one order and sent in another.
1323 static void ssh2_pkt_defer(void)
1325 int len
= ssh2_pkt_construct();
1326 if (deferred_len
+ len
> deferred_size
) {
1327 deferred_size
= deferred_len
+ len
+ 128;
1328 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1330 memcpy(deferred_send_data
+ deferred_len
, pktout
.data
, len
);
1331 deferred_len
+= len
;
1335 * Send the whole deferred data block constructed by
1336 * ssh2_pkt_defer() or SSH1's defer_packet().
1338 static void ssh_pkt_defersend(void)
1341 backlog
= sk_write(s
, deferred_send_data
, deferred_len
);
1342 deferred_len
= deferred_size
= 0;
1343 sfree(deferred_send_data
);
1344 deferred_send_data
= NULL
;
1345 if (backlog
> SSH_MAX_BACKLOG
)
1346 ssh_throttle_all(1, backlog
);
1350 void bndebug(char *string
, Bignum b
)
1354 p
= ssh2_mpint_fmt(b
, &len
);
1355 debug(("%s", string
));
1356 for (i
= 0; i
< len
; i
++)
1357 debug((" %02x", p
[i
]));
1363 static void sha_mpint(SHA_State
* s
, Bignum b
)
1367 p
= ssh2_mpint_fmt(b
, &len
);
1368 sha_string(s
, p
, len
);
1373 * SSH2 packet decode functions.
1375 static unsigned long ssh2_pkt_getuint32(void)
1377 unsigned long value
;
1378 if (pktin
.length
- pktin
.savedpos
< 4)
1379 return 0; /* arrgh, no way to decline (FIXME?) */
1380 value
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1381 pktin
.savedpos
+= 4;
1384 static int ssh2_pkt_getbool(void)
1386 unsigned long value
;
1387 if (pktin
.length
- pktin
.savedpos
< 1)
1388 return 0; /* arrgh, no way to decline (FIXME?) */
1389 value
= pktin
.data
[pktin
.savedpos
] != 0;
1393 static void ssh2_pkt_getstring(char **p
, int *length
)
1396 if (pktin
.length
- pktin
.savedpos
< 4)
1398 *length
= GET_32BIT(pktin
.data
+ pktin
.savedpos
);
1399 pktin
.savedpos
+= 4;
1400 if (pktin
.length
- pktin
.savedpos
< *length
)
1402 *p
= pktin
.data
+ pktin
.savedpos
;
1403 pktin
.savedpos
+= *length
;
1405 static Bignum
ssh2_pkt_getmp(void)
1411 ssh2_pkt_getstring(&p
, &length
);
1415 bombout(("internal error: Can't handle negative mpints"));
1418 b
= bignum_from_bytes(p
, length
);
1423 * Examine the remote side's version string and compare it against
1424 * a list of known buggy implementations.
1426 static void ssh_detect_bugs(char *vstring
)
1428 char *imp
; /* pointer to implementation part */
1430 imp
+= strcspn(imp
, "-");
1433 imp
+= strcspn(imp
, "-");
1437 ssh_remote_bugs
= 0;
1439 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1440 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1441 !strcmp(imp
, "1.2.22")) {
1443 * These versions don't support SSH1_MSG_IGNORE, so we have
1444 * to use a different defence against password length
1447 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1448 logevent("We believe remote version has SSH1 ignore bug");
1451 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1452 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1453 !strncmp(imp
, "2.1 ", 4)) {
1455 * These versions have the HMAC bug.
1457 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1458 logevent("We believe remote version has SSH2 HMAC bug");
1462 static int do_ssh_init(unsigned char c
)
1465 static char version
[10];
1466 static char *vstring
;
1467 static int vstrsize
;
1473 /* Search for the string "SSH-" in the input. */
1476 static const int transS
[] = { 1, 2, 2, 1 };
1477 static const int transH
[] = { 0, 0, 3, 0 };
1478 static const int transminus
[] = { 0, 0, 0, -1 };
1489 crReturn(1); /* get another character */
1492 vstring
= smalloc(16);
1494 strcpy(vstring
, "SSH-");
1498 crReturn(1); /* get another char */
1499 if (vslen
>= vstrsize
- 1) {
1501 vstring
= srealloc(vstring
, vstrsize
);
1503 vstring
[vslen
++] = c
;
1508 } else if (i
< sizeof(version
) - 1)
1510 } else if (c
== '\n')
1514 ssh_agentfwd_enabled
= FALSE
;
1515 rdpkt2_state
.incoming_sequence
= 0;
1518 vlog
= smalloc(20 + vslen
);
1519 sprintf(vlog
, "Server version: %s", vstring
);
1520 ssh_detect_bugs(vstring
);
1521 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1526 * Server version "1.99" means we can choose whether we use v1
1527 * or v2 protocol. Choice is based on cfg.sshprot.
1529 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1531 * This is a v2 server. Begin v2 protocol.
1533 char verstring
[80], vlog
[100];
1534 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1535 SHA_Init(&exhashbase
);
1537 * Hash our version string and their version string.
1539 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1540 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1541 sprintf(vlog
, "We claim version: %s", verstring
);
1543 strcat(verstring
, "\n");
1544 logevent("Using SSH protocol version 2");
1545 sk_write(s
, verstring
, strlen(verstring
));
1546 ssh_protocol
= ssh2_protocol
;
1548 s_rdpkt
= ssh2_rdpkt
;
1551 * This is a v1 server. Begin v1 protocol.
1553 char verstring
[80], vlog
[100];
1554 sprintf(verstring
, "SSH-%s-%s",
1555 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1557 sprintf(vlog
, "We claim version: %s", verstring
);
1559 strcat(verstring
, "\n");
1560 logevent("Using SSH protocol version 1");
1561 sk_write(s
, verstring
, strlen(verstring
));
1562 ssh_protocol
= ssh1_protocol
;
1564 s_rdpkt
= ssh1_rdpkt
;
1566 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1573 static void ssh_gotdata(unsigned char *data
, int datalen
)
1578 * To begin with, feed the characters one by one to the
1579 * protocol initialisation / selection function do_ssh_init().
1580 * When that returns 0, we're done with the initial greeting
1581 * exchange and can move on to packet discipline.
1586 crReturnV
; /* more data please */
1587 ret
= do_ssh_init(*data
);
1595 * We emerge from that loop when the initial negotiation is
1596 * over and we have selected an s_rdpkt function. Now pass
1597 * everything to s_rdpkt, and then pass the resulting packets
1598 * to the proper protocol handler.
1603 while (datalen
> 0) {
1604 if (s_rdpkt(&data
, &datalen
) == 0) {
1605 if (ssh_state
== SSH_STATE_CLOSED
) {
1608 ssh_protocol(NULL
, 0, 1);
1609 if (ssh_state
== SSH_STATE_CLOSED
) {
1619 static int ssh_closing(Plug plug
, char *error_msg
, int error_code
,
1622 ssh_state
= SSH_STATE_CLOSED
;
1628 /* A socket error has occurred. */
1629 connection_fatal(error_msg
);
1631 /* Otherwise, the remote side closed the connection normally. */
1636 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
)
1638 ssh_gotdata(data
, len
);
1639 if (ssh_state
== SSH_STATE_CLOSED
) {
1649 static void ssh_sent(Plug plug
, int bufsize
)
1652 * If the send backlog on the SSH socket itself clears, we
1653 * should unthrottle the whole world if it was throttled.
1655 if (bufsize
< SSH_MAX_BACKLOG
)
1656 ssh_throttle_all(0, bufsize
);
1660 * Connect to specified host and port.
1661 * Returns an error message, or NULL on success.
1662 * Also places the canonical host name into `realhost'. It must be
1663 * freed by the caller.
1665 static char *connect_to_host(char *host
, int port
, char **realhost
)
1667 static struct plug_function_table fn_table
= {
1672 }, *fn_table_ptr
= &fn_table
;
1681 savedhost
= smalloc(1 + strlen(host
));
1683 fatalbox("Out of memory");
1684 strcpy(savedhost
, host
);
1687 port
= 22; /* default ssh port */
1702 sprintf(buf
, "Looking up host \"%.170s\"", host
);
1705 addr
= sk_namelookup(host
, realhost
);
1706 if ((err
= sk_addr_error(addr
)))
1710 *realhost
= strdup(FWhost
);
1717 char buf
[200], addrbuf
[100];
1718 sk_getaddr(addr
, addrbuf
, 100);
1719 sprintf(buf
, "Connecting to %.100s port %d", addrbuf
, port
);
1722 s
= sk_new(addr
, port
, 0, 1, &fn_table_ptr
);
1723 if ((err
= sk_socket_error(s
)))
1727 sk_write(s
, "connect ", 8);
1728 sk_write(s
, FWhost
, strlen(FWhost
));
1731 sprintf(buf
, " %d\n", FWport
);
1732 sk_write(s
, buf
, strlen(buf
));
1740 * Throttle or unthrottle the SSH connection.
1742 static void ssh1_throttle(int adjust
)
1744 int old_count
= ssh1_throttle_count
;
1745 ssh1_throttle_count
+= adjust
;
1746 assert(ssh1_throttle_count
>= 0);
1747 if (ssh1_throttle_count
&& !old_count
) {
1748 sk_set_frozen(s
, 1);
1749 } else if (!ssh1_throttle_count
&& old_count
) {
1750 sk_set_frozen(s
, 0);
1755 * Throttle or unthrottle _all_ local data streams (for when sends
1756 * on the SSH connection itself back up).
1758 static void ssh_throttle_all(int enable
, int bufsize
)
1761 struct ssh_channel
*c
;
1763 if (enable
== ssh_throttled_all
)
1765 ssh_throttled_all
= enable
;
1766 ssh_overall_bufsize
= bufsize
;
1769 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
1771 case CHAN_MAINSESSION
:
1773 * This is treated separately, outside the switch.
1777 x11_override_throttle(c
->u
.x11
.s
, enable
);
1780 /* Agent channels require no buffer management. */
1783 pfd_override_throttle(c
->u
.x11
.s
, enable
);
1790 * Handle the key exchange and user authentication phases.
1792 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1796 static unsigned char *rsabuf
, *keystr1
, *keystr2
;
1797 unsigned char cookie
[8];
1798 struct RSAKey servkey
, hostkey
;
1799 struct MD5Context md5c
;
1800 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1801 static int tried_publickey
;
1802 static int tis_auth_refused
, ccard_auth_refused
;
1803 static unsigned char session_id
[16];
1804 static int cipher_type
;
1805 static char username
[100];
1812 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1813 bombout(("Public key packet not received"));
1817 logevent("Received public keys");
1819 memcpy(cookie
, pktin
.body
, 8);
1821 i
= makekey(pktin
.body
+ 8, &servkey
, &keystr1
, 0);
1822 j
= makekey(pktin
.body
+ 8 + i
, &hostkey
, &keystr2
, 0);
1825 * Log the host key fingerprint.
1829 logevent("Host key fingerprint is:");
1830 strcpy(logmsg
, " ");
1831 hostkey
.comment
= NULL
;
1832 rsa_fingerprint(logmsg
+ strlen(logmsg
),
1833 sizeof(logmsg
) - strlen(logmsg
), &hostkey
);
1837 ssh1_remote_protoflags
= GET_32BIT(pktin
.body
+ 8 + i
+ j
);
1838 supported_ciphers_mask
= GET_32BIT(pktin
.body
+ 12 + i
+ j
);
1839 supported_auths_mask
= GET_32BIT(pktin
.body
+ 16 + i
+ j
);
1841 ssh1_local_protoflags
=
1842 ssh1_remote_protoflags
& SSH1_PROTOFLAGS_SUPPORTED
;
1843 ssh1_local_protoflags
|= SSH1_PROTOFLAG_SCREEN_NUMBER
;
1846 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1847 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1848 MD5Update(&md5c
, pktin
.body
, 8);
1849 MD5Final(session_id
, &md5c
);
1851 for (i
= 0; i
< 32; i
++)
1852 session_key
[i
] = random_byte();
1854 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1856 rsabuf
= smalloc(len
);
1858 fatalbox("Out of memory");
1861 * Verify the host key.
1865 * First format the key into a string.
1867 int len
= rsastr_len(&hostkey
);
1868 char fingerprint
[100];
1869 char *keystr
= smalloc(len
);
1871 fatalbox("Out of memory");
1872 rsastr_fmt(keystr
, &hostkey
);
1873 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1874 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
,
1879 for (i
= 0; i
< 32; i
++) {
1880 rsabuf
[i
] = session_key
[i
];
1882 rsabuf
[i
] ^= session_id
[i
];
1885 if (hostkey
.bytes
> servkey
.bytes
) {
1886 rsaencrypt(rsabuf
, 32, &servkey
);
1887 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1889 rsaencrypt(rsabuf
, 32, &hostkey
);
1890 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1893 logevent("Encrypted session key");
1896 int cipher_chosen
= 0, warn
= 0;
1897 char *cipher_string
= NULL
;
1898 for (i
= 0; !cipher_chosen
&& i
< CIPHER_MAX
; i
++) {
1899 int next_cipher
= cfg
.ssh_cipherlist
[i
];
1900 if (next_cipher
== CIPHER_WARN
) {
1901 /* If/when we choose a cipher, warn about it */
1903 } else if (next_cipher
== CIPHER_AES
) {
1904 /* XXX Probably don't need to mention this. */
1905 logevent("AES not supported in SSH1, skipping");
1907 switch (next_cipher
) {
1908 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
;
1909 cipher_string
= "3DES"; break;
1910 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
;
1911 cipher_string
= "Blowfish"; break;
1912 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
;
1913 cipher_string
= "single-DES"; break;
1915 if (supported_ciphers_mask
& (1 << cipher_type
))
1919 if (!cipher_chosen
) {
1920 if ((supported_ciphers_mask
& (1 << SSH_CIPHER_3DES
)) == 0)
1921 bombout(("Server violates SSH 1 protocol by not "
1922 "supporting 3DES encryption"));
1924 /* shouldn't happen */
1925 bombout(("No supported ciphers found"));
1929 /* Warn about chosen cipher if necessary. */
1931 askcipher(cipher_string
, 0);
1934 switch (cipher_type
) {
1935 case SSH_CIPHER_3DES
:
1936 logevent("Using 3DES encryption");
1938 case SSH_CIPHER_DES
:
1939 logevent("Using single-DES encryption");
1941 case SSH_CIPHER_BLOWFISH
:
1942 logevent("Using Blowfish encryption");
1946 send_packet(SSH1_CMSG_SESSION_KEY
,
1947 PKT_CHAR
, cipher_type
,
1948 PKT_DATA
, cookie
, 8,
1949 PKT_CHAR
, (len
* 8) >> 8, PKT_CHAR
, (len
* 8) & 0xFF,
1950 PKT_DATA
, rsabuf
, len
,
1951 PKT_INT
, ssh1_local_protoflags
, PKT_END
);
1953 logevent("Trying to enable encryption...");
1957 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1958 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
: &ssh_3des
;
1959 cipher
->sesskey(session_key
);
1963 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1964 bombout(("Encryption not successfully enabled"));
1968 logevent("Successfully started encryption");
1974 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1976 if (!ssh_get_line("login as: ",
1977 username
, sizeof(username
), FALSE
)) {
1979 * get_line failed to get a username.
1982 logevent("No username provided. Abandoning session.");
1983 ssh_state
= SSH_STATE_CLOSED
;
1987 c_write_str("login as: ");
1990 crWaitUntil(!ispkt
);
1992 switch (c
= *in
++) {
2001 c_write_str("\b \b");
2008 c_write_str("\b \b");
2018 if (((c
>= ' ' && c
<= '~') ||
2019 ((unsigned char) c
>= 160))
2020 && pos
< sizeof(username
)-1) {
2021 username
[pos
++] = c
;
2027 c_write_str("\r\n");
2028 username
[strcspn(username
, "\n\r")] = '\0';
2031 strncpy(username
, cfg
.username
, 99);
2032 username
[99] = '\0';
2035 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
2037 char userlog
[22 + sizeof(username
)];
2038 sprintf(userlog
, "Sent username \"%s\"", username
);
2040 if (flags
& FLAG_INTERACTIVE
&&
2041 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
2042 strcat(userlog
, "\r\n");
2043 c_write_str(userlog
);
2050 tried_publickey
= 0;
2051 tis_auth_refused
= ccard_auth_refused
= 0;
2053 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
2054 static char password
[100];
2055 static char prompt
[200];
2058 static int pwpkt_type
;
2059 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
2061 if (agent_exists()) {
2063 * Attempt RSA authentication using Pageant.
2065 static unsigned char request
[5], *response
, *p
;
2066 static int responselen
;
2067 static int i
, nkeys
;
2068 static int authed
= FALSE
;
2071 logevent("Pageant is running. Requesting keys.");
2073 /* Request the keys held by the agent. */
2074 PUT_32BIT(request
, 1);
2075 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
2076 agent_query(request
, 5, &r
, &responselen
);
2077 response
= (unsigned char *) r
;
2078 if (response
&& responselen
>= 5 &&
2079 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
2081 nkeys
= GET_32BIT(p
);
2085 sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
2088 for (i
= 0; i
< nkeys
; i
++) {
2089 static struct RSAKey key
;
2090 static Bignum challenge
;
2091 static char *commentp
;
2092 static int commentlen
;
2096 sprintf(buf
, "Trying Pageant key #%d", i
);
2100 p
+= ssh1_read_bignum(p
, &key
.exponent
);
2101 p
+= ssh1_read_bignum(p
, &key
.modulus
);
2102 commentlen
= GET_32BIT(p
);
2106 send_packet(SSH1_CMSG_AUTH_RSA
,
2107 PKT_BIGNUM
, key
.modulus
, PKT_END
);
2109 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2110 logevent("Key refused");
2113 logevent("Received RSA challenge");
2114 ssh1_read_bignum(pktin
.body
, &challenge
);
2116 char *agentreq
, *q
, *ret
;
2119 len
= 1 + 4; /* message type, bit count */
2120 len
+= ssh1_bignum_length(key
.exponent
);
2121 len
+= ssh1_bignum_length(key
.modulus
);
2122 len
+= ssh1_bignum_length(challenge
);
2123 len
+= 16; /* session id */
2124 len
+= 4; /* response format */
2125 agentreq
= smalloc(4 + len
);
2126 PUT_32BIT(agentreq
, len
);
2128 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
2129 PUT_32BIT(q
, bignum_bitcount(key
.modulus
));
2131 q
+= ssh1_write_bignum(q
, key
.exponent
);
2132 q
+= ssh1_write_bignum(q
, key
.modulus
);
2133 q
+= ssh1_write_bignum(q
, challenge
);
2134 memcpy(q
, session_id
, 16);
2136 PUT_32BIT(q
, 1); /* response format */
2137 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
2141 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
2142 logevent("Sending Pageant's response");
2143 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2144 PKT_DATA
, ret
+ 5, 16,
2148 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2150 ("Pageant's response accepted");
2151 if (flags
& FLAG_VERBOSE
) {
2153 ("Authenticated using RSA key \"");
2154 c_write(commentp
, commentlen
);
2155 c_write_str("\" from agent\r\n");
2160 ("Pageant's response not accepted");
2163 ("Pageant failed to answer challenge");
2167 logevent("No reply received from Pageant");
2170 freebn(key
.exponent
);
2171 freebn(key
.modulus
);
2180 if (*cfg
.keyfile
&& !tried_publickey
)
2181 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
2183 if (cfg
.try_tis_auth
&&
2184 (supported_auths_mask
& (1 << SSH1_AUTH_TIS
)) &&
2185 !tis_auth_refused
) {
2186 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
2187 logevent("Requested TIS authentication");
2188 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
2190 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
2191 logevent("TIS authentication declined");
2192 if (flags
& FLAG_INTERACTIVE
)
2193 c_write_str("TIS authentication refused.\r\n");
2194 tis_auth_refused
= 1;
2197 int challengelen
= ((pktin
.body
[0] << 24) |
2198 (pktin
.body
[1] << 16) |
2199 (pktin
.body
[2] << 8) |
2201 logevent("Received TIS challenge");
2202 if (challengelen
> sizeof(prompt
) - 1)
2203 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2204 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2205 /* Prompt heuristic comes from OpenSSH */
2206 strncpy(prompt
+ challengelen
,
2207 memchr(prompt
, '\n', challengelen
) ?
2208 "": "\r\nResponse: ",
2209 (sizeof prompt
) - challengelen
);
2210 prompt
[(sizeof prompt
) - 1] = '\0';
2213 if (cfg
.try_tis_auth
&&
2214 (supported_auths_mask
& (1 << SSH1_AUTH_CCARD
)) &&
2215 !ccard_auth_refused
) {
2216 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
2217 logevent("Requested CryptoCard authentication");
2218 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
2220 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
2221 logevent("CryptoCard authentication declined");
2222 c_write_str("CryptoCard authentication refused.\r\n");
2223 ccard_auth_refused
= 1;
2226 int challengelen
= ((pktin
.body
[0] << 24) |
2227 (pktin
.body
[1] << 16) |
2228 (pktin
.body
[2] << 8) |
2230 logevent("Received CryptoCard challenge");
2231 if (challengelen
> sizeof(prompt
) - 1)
2232 challengelen
= sizeof(prompt
) - 1; /* prevent overrun */
2233 memcpy(prompt
, pktin
.body
+ 4, challengelen
);
2234 strncpy(prompt
+ challengelen
,
2235 memchr(prompt
, '\n', challengelen
) ?
2236 "" : "\r\nResponse: ",
2237 sizeof(prompt
) - challengelen
);
2238 prompt
[sizeof(prompt
) - 1] = '\0';
2241 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2242 sprintf(prompt
, "%.90s@%.90s's password: ",
2243 username
, savedhost
);
2245 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2246 char *comment
= NULL
;
2247 if (flags
& FLAG_VERBOSE
)
2248 c_write_str("Trying public key authentication.\r\n");
2249 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
2250 if (flags
& FLAG_VERBOSE
)
2251 c_write_str("No passphrase required.\r\n");
2254 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
2259 * Show password prompt, having first obtained it via a TIS
2260 * or CryptoCard exchange if we're doing TIS or CryptoCard
2264 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
2266 * get_line failed to get a password (for example
2267 * because one was supplied on the command line
2268 * which has already failed to work). Terminate.
2270 send_packet(SSH1_MSG_DISCONNECT
,
2271 PKT_STR
, "No more passwords available to try",
2273 connection_fatal("Unable to authenticate");
2274 ssh_state
= SSH_STATE_CLOSED
;
2278 /* Prompt may have come from server. We've munged it a bit, so
2279 * we know it to be zero-terminated at least once. */
2280 c_write_untrusted(prompt
, strlen(prompt
));
2284 crWaitUntil(!ispkt
);
2286 switch (c
= *in
++) {
2307 if (pos
< sizeof(password
)-1)
2308 password
[pos
++] = c
;
2312 c_write_str("\r\n");
2316 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
2318 * Try public key authentication with the specified
2321 static struct RSAKey pubkey
;
2322 static Bignum challenge
, response
;
2324 static unsigned char buffer
[32];
2326 tried_publickey
= 1;
2327 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
2329 c_write_str("Couldn't load private key from ");
2330 c_write_str(cfg
.keyfile
);
2331 c_write_str(".\r\n");
2332 continue; /* go and try password */
2335 c_write_str("Wrong passphrase.\r\n");
2336 tried_publickey
= 0;
2337 continue; /* try again */
2341 * Send a public key attempt.
2343 send_packet(SSH1_CMSG_AUTH_RSA
,
2344 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
2347 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2348 c_write_str("Server refused our public key.\r\n");
2349 continue; /* go and try password */
2351 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
2352 bombout(("Bizarre response to offer of public key"));
2355 ssh1_read_bignum(pktin
.body
, &challenge
);
2356 response
= rsadecrypt(challenge
, &pubkey
);
2357 freebn(pubkey
.private_exponent
); /* burn the evidence */
2359 for (i
= 0; i
< 32; i
++) {
2360 buffer
[i
] = bignum_byte(response
, 31 - i
);
2364 MD5Update(&md5c
, buffer
, 32);
2365 MD5Update(&md5c
, session_id
, 16);
2366 MD5Final(buffer
, &md5c
);
2368 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
2369 PKT_DATA
, buffer
, 16, PKT_END
);
2372 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2373 if (flags
& FLAG_VERBOSE
)
2375 ("Failed to authenticate with our public key.\r\n");
2376 continue; /* go and try password */
2377 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2379 ("Bizarre response to RSA authentication response"));
2383 break; /* we're through! */
2385 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
2387 * Defence against traffic analysis: we send a
2388 * whole bunch of packets containing strings of
2389 * different lengths. One of these strings is the
2390 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2391 * The others are all random data in
2392 * SSH1_MSG_IGNORE packets. This way a passive
2393 * listener can't tell which is the password, and
2394 * hence can't deduce the password length.
2396 * Anybody with a password length greater than 16
2397 * bytes is going to have enough entropy in their
2398 * password that a listener won't find it _that_
2399 * much help to know how long it is. So what we'll
2402 * - if password length < 16, we send 15 packets
2403 * containing string lengths 1 through 15
2405 * - otherwise, we let N be the nearest multiple
2406 * of 8 below the password length, and send 8
2407 * packets containing string lengths N through
2408 * N+7. This won't obscure the order of
2409 * magnitude of the password length, but it will
2410 * introduce a bit of extra uncertainty.
2412 * A few servers (the old 1.2.18 through 1.2.22)
2413 * can't deal with SSH1_MSG_IGNORE. For these
2414 * servers, we need an alternative defence. We make
2415 * use of the fact that the password is interpreted
2416 * as a C string: so we can append a NUL, then some
2419 if (ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) {
2424 len
= strlen(password
);
2425 if (len
< sizeof(string
)) {
2427 strcpy(string
, password
);
2428 len
++; /* cover the zero byte */
2429 while (len
< sizeof(string
)) {
2430 string
[len
++] = (char) random_byte();
2435 send_packet(pwpkt_type
, PKT_INT
, len
,
2436 PKT_DATA
, s
, len
, PKT_END
);
2438 int bottom
, top
, pwlen
, i
;
2441 pwlen
= strlen(password
);
2443 bottom
= 0; /* zero length passwords are OK! :-) */
2446 bottom
= pwlen
& ~7;
2450 assert(pwlen
>= bottom
&& pwlen
<= top
);
2452 randomstr
= smalloc(top
+ 1);
2454 for (i
= bottom
; i
<= top
; i
++) {
2456 defer_packet(pwpkt_type
, PKT_STR
, password
,
2459 for (j
= 0; j
< i
; j
++) {
2461 randomstr
[j
] = random_byte();
2462 } while (randomstr
[j
] == '\0');
2464 randomstr
[i
] = '\0';
2465 defer_packet(SSH1_MSG_IGNORE
,
2466 PKT_STR
, randomstr
, PKT_END
);
2469 ssh_pkt_defersend();
2472 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
2475 logevent("Sent password");
2476 memset(password
, 0, strlen(password
));
2478 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2479 if (flags
& FLAG_VERBOSE
)
2480 c_write_str("Access denied\r\n");
2481 logevent("Authentication refused");
2482 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2483 logevent("Received disconnect request");
2484 ssh_state
= SSH_STATE_CLOSED
;
2486 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
2487 bombout(("Strange packet received, type %d", pktin
.type
));
2492 logevent("Authentication successful");
2497 void sshfwd_close(struct ssh_channel
*c
)
2499 if (c
&& !c
->closes
) {
2500 if (ssh_version
== 1) {
2501 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
,
2504 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2505 ssh2_pkt_adduint32(c
->remoteid
);
2509 if (c
->type
== CHAN_X11
) {
2511 logevent("Forwarded X11 connection terminated");
2512 } else if (c
->type
== CHAN_SOCKDATA
) {
2514 logevent("Forwarded port closed");
2519 int sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
)
2521 if (ssh_version
== 1) {
2522 send_packet(SSH1_MSG_CHANNEL_DATA
,
2523 PKT_INT
, c
->remoteid
,
2524 PKT_INT
, len
, PKT_DATA
, buf
, len
, PKT_END
);
2526 * In SSH1 we can return 0 here - implying that forwarded
2527 * connections are never individually throttled - because
2528 * the only circumstance that can cause throttling will be
2529 * the whole SSH connection backing up, in which case
2530 * _everything_ will be throttled as a whole.
2534 ssh2_add_channel_data(c
, buf
, len
);
2535 return ssh2_try_send(c
);
2539 void sshfwd_unthrottle(struct ssh_channel
*c
, int bufsize
)
2541 if (ssh_version
== 1) {
2542 if (c
->v
.v1
.throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
2543 c
->v
.v1
.throttling
= 0;
2547 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
2551 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
)
2557 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2560 if (ssh_state
== SSH_STATE_CLOSED
)
2563 if (cfg
.agentfwd
&& agent_exists()) {
2564 logevent("Requesting agent forwarding");
2565 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2569 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2570 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2571 bombout(("Protocol confusion"));
2573 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2574 logevent("Agent forwarding refused");
2576 logevent("Agent forwarding enabled");
2577 ssh_agentfwd_enabled
= TRUE
;
2581 if (cfg
.x11_forward
) {
2582 char proto
[20], data
[64];
2583 logevent("Requesting X11 forwarding");
2584 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2585 if (ssh1_local_protoflags
& SSH1_PROTOFLAG_SCREEN_NUMBER
) {
2586 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2587 PKT_STR
, proto
, PKT_STR
, data
,
2588 PKT_INT
, 0, PKT_END
);
2590 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2591 PKT_STR
, proto
, PKT_STR
, data
, PKT_END
);
2596 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2597 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2598 bombout(("Protocol confusion"));
2600 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2601 logevent("X11 forwarding refused");
2603 logevent("X11 forwarding enabled");
2604 ssh_X11_fwd_enabled
= TRUE
;
2612 char sports
[256], dports
[256], host
[256];
2615 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh1
);
2616 /* Add port forwardings. */
2621 while (*e
&& *e
!= '\t')
2627 while (*e
&& *e
!= ':')
2637 dport
= atoi(dports
);
2638 sport
= atoi(sports
);
2639 if (sport
&& dport
) {
2641 pfd_addforward(host
, dport
, sport
);
2642 sprintf(buf
, "Local port %d forwarding to %s:%d",
2643 sport
, host
, dport
);
2646 struct ssh_rportfwd
*pf
;
2647 pf
= smalloc(sizeof(*pf
));
2648 strcpy(pf
->dhost
, host
);
2650 if (add234(ssh_rportfwds
, pf
) != pf
) {
2652 "Duplicate remote port forwarding to %s:%d",
2657 sprintf(buf
, "Requesting remote port %d forward to %s:%d",
2658 sport
, host
, dport
);
2660 send_packet(SSH1_CMSG_PORT_FORWARD_REQUEST
,
2672 send_packet(SSH1_CMSG_REQUEST_PTY
,
2673 PKT_STR
, cfg
.termtype
,
2674 PKT_INT
, rows
, PKT_INT
, cols
,
2675 PKT_INT
, 0, PKT_INT
, 0, PKT_CHAR
, 0, PKT_END
);
2676 ssh_state
= SSH_STATE_INTERMED
;
2680 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2681 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2682 bombout(("Protocol confusion"));
2684 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2685 c_write_str("Server refused to allocate pty\r\n");
2686 ssh_editing
= ssh_echoing
= 1;
2688 logevent("Allocated pty");
2690 ssh_editing
= ssh_echoing
= 1;
2693 if (cfg
.compression
) {
2694 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2698 if (pktin
.type
!= SSH1_SMSG_SUCCESS
2699 && pktin
.type
!= SSH1_SMSG_FAILURE
) {
2700 bombout(("Protocol confusion"));
2702 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2703 c_write_str("Server refused to compress\r\n");
2705 logevent("Started compression");
2706 ssh1_compressing
= TRUE
;
2707 zlib_compress_init();
2708 zlib_decompress_init();
2712 * Start the shell or command.
2714 * Special case: if the first-choice command is an SSH2
2715 * subsystem (hence not usable here) and the second choice
2716 * exists, we fall straight back to that.
2719 char *cmd
= cfg
.remote_cmd_ptr
;
2721 if (cfg
.ssh_subsys
&& cfg
.remote_cmd_ptr2
) {
2722 cmd
= cfg
.remote_cmd_ptr2
;
2723 ssh_fallback_cmd
= TRUE
;
2726 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cmd
, PKT_END
);
2728 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2729 logevent("Started session");
2732 ssh_state
= SSH_STATE_SESSION
;
2736 ssh_special(TS_EOF
);
2738 ldisc_send(NULL
, 0); /* cause ldisc to notice changes */
2740 ssh_channels
= newtree234(ssh_channelcmp
);
2744 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2745 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2746 long len
= GET_32BIT(pktin
.body
);
2748 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2749 pktin
.body
+ 4, len
);
2750 if (!ssh1_stdout_throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2751 ssh1_stdout_throttling
= 1;
2754 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2755 ssh_state
= SSH_STATE_CLOSED
;
2756 logevent("Received disconnect request");
2758 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2759 /* Remote side is trying to open a channel to talk to our
2760 * X-Server. Give them back a local channel number. */
2761 struct ssh_channel
*c
;
2763 logevent("Received X11 connect request");
2764 /* Refuse if X11 forwarding is disabled. */
2765 if (!ssh_X11_fwd_enabled
) {
2766 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2767 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2768 logevent("Rejected X11 connect request");
2770 c
= smalloc(sizeof(struct ssh_channel
));
2772 if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2773 logevent("opening X11 forward connection failed");
2775 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2776 PKT_INT
, GET_32BIT(pktin
.body
),
2780 ("opening X11 forward connection succeeded");
2781 c
->remoteid
= GET_32BIT(pktin
.body
);
2782 c
->localid
= alloc_channel_id();
2784 c
->v
.v1
.throttling
= 0;
2785 c
->type
= CHAN_X11
; /* identify channel type */
2786 add234(ssh_channels
, c
);
2787 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2788 PKT_INT
, c
->remoteid
, PKT_INT
,
2789 c
->localid
, PKT_END
);
2790 logevent("Opened X11 forward channel");
2793 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2794 /* Remote side is trying to open a channel to talk to our
2795 * agent. Give them back a local channel number. */
2796 struct ssh_channel
*c
;
2798 /* Refuse if agent forwarding is disabled. */
2799 if (!ssh_agentfwd_enabled
) {
2800 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2801 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2803 c
= smalloc(sizeof(struct ssh_channel
));
2804 c
->remoteid
= GET_32BIT(pktin
.body
);
2805 c
->localid
= alloc_channel_id();
2807 c
->v
.v1
.throttling
= 0;
2808 c
->type
= CHAN_AGENT
; /* identify channel type */
2809 c
->u
.a
.lensofar
= 0;
2810 add234(ssh_channels
, c
);
2811 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2812 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2815 } else if (pktin
.type
== SSH1_MSG_PORT_OPEN
) {
2816 /* Remote side is trying to open a channel to talk to a
2817 * forwarded port. Give them back a local channel number. */
2818 struct ssh_channel
*c
;
2819 struct ssh_rportfwd pf
;
2821 char host
[256], buf
[1024];
2823 c
= smalloc(sizeof(struct ssh_channel
));
2825 hostsize
= GET_32BIT(pktin
.body
+4);
2826 for(h
= host
, p
= pktin
.body
+8; hostsize
!= 0; hostsize
--) {
2827 if (h
+1 < host
+sizeof(host
))
2832 port
= GET_32BIT(p
);
2834 strcpy(pf
.dhost
, host
);
2837 if (find234(ssh_rportfwds
, &pf
, NULL
) == NULL
) {
2838 sprintf(buf
, "Rejected remote port open request for %s:%d",
2841 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2842 PKT_INT
, GET_32BIT(pktin
.body
), PKT_END
);
2844 sprintf(buf
, "Received remote port open request for %s:%d",
2847 e
= pfd_newconnect(&c
->u
.pfd
.s
, host
, port
, c
);
2850 sprintf(buf
, "Port open failed: %s", e
);
2853 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2854 PKT_INT
, GET_32BIT(pktin
.body
),
2857 c
->remoteid
= GET_32BIT(pktin
.body
);
2858 c
->localid
= alloc_channel_id();
2860 c
->v
.v1
.throttling
= 0;
2861 c
->type
= CHAN_SOCKDATA
; /* identify channel type */
2862 add234(ssh_channels
, c
);
2863 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2864 PKT_INT
, c
->remoteid
, PKT_INT
,
2865 c
->localid
, PKT_END
);
2866 logevent("Forwarded port opened successfully");
2870 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2871 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2872 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2873 struct ssh_channel
*c
;
2875 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2876 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2877 c
->remoteid
= localid
;
2878 c
->type
= CHAN_SOCKDATA
;
2879 pfd_confirm(c
->u
.pfd
.s
);
2882 } else if (pktin
.type
== SSH1_MSG_CHANNEL_OPEN_FAILURE
) {
2883 unsigned int remoteid
= GET_32BIT(pktin
.body
);
2884 unsigned int localid
= GET_32BIT(pktin
.body
+4);
2885 struct ssh_channel
*c
;
2887 c
= find234(ssh_channels
, &remoteid
, ssh_channelfind
);
2888 if (c
&& c
->type
== CHAN_SOCKDATA_DORMANT
) {
2889 logevent("Forwarded connection refused by server");
2890 pfd_close(c
->u
.pfd
.s
);
2891 del234(ssh_channels
, c
);
2895 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
2896 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
2897 /* Remote side closes a channel. */
2898 unsigned i
= GET_32BIT(pktin
.body
);
2899 struct ssh_channel
*c
;
2900 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2904 (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
2905 if (!(c
->closes
& closetype
))
2906 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
,
2908 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
2909 logevent("Forwarded X11 connection terminated");
2910 assert(c
->u
.x11
.s
!= NULL
);
2911 x11_close(c
->u
.x11
.s
);
2914 if ((c
->closes
== 0) && (c
->type
== CHAN_SOCKDATA
)) {
2915 logevent("Forwarded port closed");
2916 assert(c
->u
.pfd
.s
!= NULL
);
2917 pfd_close(c
->u
.pfd
.s
);
2920 c
->closes
|= closetype
;
2921 if (c
->closes
== 3) {
2922 del234(ssh_channels
, c
);
2926 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
2927 /* Data sent down one of our channels. */
2928 int i
= GET_32BIT(pktin
.body
);
2929 int len
= GET_32BIT(pktin
.body
+ 4);
2930 unsigned char *p
= pktin
.body
+ 8;
2931 struct ssh_channel
*c
;
2932 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2937 bufsize
= x11_send(c
->u
.x11
.s
, p
, len
);
2940 bufsize
= pfd_send(c
->u
.pfd
.s
, p
, len
);
2943 /* Data for an agent message. Buffer it. */
2945 if (c
->u
.a
.lensofar
< 4) {
2946 int l
= min(4 - c
->u
.a
.lensofar
, len
);
2947 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
,
2951 c
->u
.a
.lensofar
+= l
;
2953 if (c
->u
.a
.lensofar
== 4) {
2955 4 + GET_32BIT(c
->u
.a
.msglen
);
2956 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
2957 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
2959 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
2961 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
2963 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
,
2967 c
->u
.a
.lensofar
+= l
;
2969 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
2970 void *reply
, *sentreply
;
2972 agent_query(c
->u
.a
.message
,
2973 c
->u
.a
.totallen
, &reply
,
2978 /* Fake SSH_AGENT_FAILURE. */
2979 sentreply
= "\0\0\0\1\5";
2982 send_packet(SSH1_MSG_CHANNEL_DATA
,
2983 PKT_INT
, c
->remoteid
,
2985 PKT_DATA
, sentreply
, replylen
,
2989 sfree(c
->u
.a
.message
);
2990 c
->u
.a
.lensofar
= 0;
2993 bufsize
= 0; /* agent channels never back up */
2996 if (!c
->v
.v1
.throttling
&& bufsize
> SSH1_BUFFER_LIMIT
) {
2997 c
->v
.v1
.throttling
= 1;
3001 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
3002 /* may be from EXEC_SHELL on some servers */
3003 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
3004 /* may be from EXEC_SHELL on some servers
3005 * if no pty is available or in other odd cases. Ignore */
3006 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
3007 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
3009 bombout(("Strange packet received: type %d", pktin
.type
));
3014 int len
= min(inlen
, 512);
3015 send_packet(SSH1_CMSG_STDIN_DATA
,
3016 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
3027 * Utility routine for decoding comma-separated strings in KEXINIT.
3029 static int in_commasep_string(char *needle
, char *haystack
, int haylen
)
3031 int needlen
= strlen(needle
);
3034 * Is it at the start of the string?
3036 if (haylen
>= needlen
&& /* haystack is long enough */
3037 !memcmp(needle
, haystack
, needlen
) && /* initial match */
3038 (haylen
== needlen
|| haystack
[needlen
] == ',')
3039 /* either , or EOS follows */
3043 * If not, search for the next comma and resume after that.
3044 * If no comma found, terminate.
3046 while (haylen
> 0 && *haystack
!= ',')
3047 haylen
--, haystack
++;
3050 haylen
--, haystack
++; /* skip over comma itself */
3055 * SSH2 key creation method.
3057 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
,
3061 /* First 20 bytes. */
3064 SHA_Bytes(&s
, H
, 20);
3065 SHA_Bytes(&s
, &chr
, 1);
3066 SHA_Bytes(&s
, sessid
, 20);
3067 SHA_Final(&s
, keyspace
);
3068 /* Next 20 bytes. */
3071 SHA_Bytes(&s
, H
, 20);
3072 SHA_Bytes(&s
, keyspace
, 20);
3073 SHA_Final(&s
, keyspace
+ 20);
3077 * Handle the SSH2 transport layer.
3079 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
3081 static int i
, j
, len
, nbits
, pbits
, warn
;
3083 static Bignum p
, g
, e
, f
, K
;
3084 static int kex_init_value
, kex_reply_value
;
3085 static const struct ssh_mac
**maclist
;
3087 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
3088 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
3089 static const struct ssh_mac
*csmac_tobe
= NULL
;
3090 static const struct ssh_mac
*scmac_tobe
= NULL
;
3091 static const struct ssh_compress
*cscomp_tobe
= NULL
;
3092 static const struct ssh_compress
*sccomp_tobe
= NULL
;
3093 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
3094 static int hostkeylen
, siglen
;
3095 static void *hkey
; /* actual host key */
3096 static unsigned char exchange_hash
[20];
3097 static unsigned char keyspace
[40];
3098 static int n_preferred_ciphers
;
3099 static const struct ssh2_ciphers
*preferred_ciphers
[CIPHER_MAX
];
3100 static const struct ssh_compress
*preferred_comp
;
3101 static int first_kex
;
3108 * Set up the preferred ciphers. (NULL => warn below here)
3110 n_preferred_ciphers
= 0;
3111 for (i
= 0; i
< CIPHER_MAX
; i
++) {
3112 switch (cfg
.ssh_cipherlist
[i
]) {
3113 case CIPHER_BLOWFISH
:
3114 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_blowfish
;
3115 n_preferred_ciphers
++;
3118 /* Not supported in SSH2; silently drop */
3121 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_3des
;
3122 n_preferred_ciphers
++;
3125 preferred_ciphers
[n_preferred_ciphers
] = &ssh2_aes
;
3126 n_preferred_ciphers
++;
3129 /* Flag for later. Don't bother if it's the last in
3131 if (i
< CIPHER_MAX
- 1) {
3132 preferred_ciphers
[n_preferred_ciphers
] = NULL
;
3133 n_preferred_ciphers
++;
3140 * Set up preferred compression.
3142 if (cfg
.compression
)
3143 preferred_comp
= &ssh_zlib
;
3145 preferred_comp
= &ssh_comp_none
;
3148 * Be prepared to work around the buggy MAC problem.
3150 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
3151 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
3153 maclist
= macs
, nmacs
= lenof(macs
);
3157 * Construct and send our key exchange packet.
3159 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
3160 for (i
= 0; i
< 16; i
++)
3161 ssh2_pkt_addbyte((unsigned char) random_byte());
3162 /* List key exchange algorithms. */
3163 ssh2_pkt_addstring_start();
3164 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3165 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
3166 if (i
< lenof(kex_algs
) - 1)
3167 ssh2_pkt_addstring_str(",");
3169 /* List server host key algorithms. */
3170 ssh2_pkt_addstring_start();
3171 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3172 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
3173 if (i
< lenof(hostkey_algs
) - 1)
3174 ssh2_pkt_addstring_str(",");
3176 /* List client->server encryption algorithms. */
3177 ssh2_pkt_addstring_start();
3178 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3179 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3180 if (!c
) continue; /* warning flag */
3181 for (j
= 0; j
< c
->nciphers
; j
++) {
3182 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3183 if (i
< n_preferred_ciphers
|| j
< c
->nciphers
- 1)
3184 ssh2_pkt_addstring_str(",");
3187 /* List server->client encryption algorithms. */
3188 ssh2_pkt_addstring_start();
3189 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3190 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3191 if (!c
) continue; /* warning flag */
3192 for (j
= 0; j
< c
->nciphers
; j
++) {
3193 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
3194 if (i
< n_preferred_ciphers
|| j
< c
->nciphers
- 1)
3195 ssh2_pkt_addstring_str(",");
3198 /* List client->server MAC algorithms. */
3199 ssh2_pkt_addstring_start();
3200 for (i
= 0; i
< nmacs
; i
++) {
3201 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3203 ssh2_pkt_addstring_str(",");
3205 /* List server->client MAC algorithms. */
3206 ssh2_pkt_addstring_start();
3207 for (i
= 0; i
< nmacs
; i
++) {
3208 ssh2_pkt_addstring_str(maclist
[i
]->name
);
3210 ssh2_pkt_addstring_str(",");
3212 /* List client->server compression algorithms. */
3213 ssh2_pkt_addstring_start();
3214 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3215 const struct ssh_compress
*c
=
3216 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3217 ssh2_pkt_addstring_str(c
->name
);
3218 if (i
< lenof(compressions
))
3219 ssh2_pkt_addstring_str(",");
3221 /* List server->client compression algorithms. */
3222 ssh2_pkt_addstring_start();
3223 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3224 const struct ssh_compress
*c
=
3225 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3226 ssh2_pkt_addstring_str(c
->name
);
3227 if (i
< lenof(compressions
))
3228 ssh2_pkt_addstring_str(",");
3230 /* List client->server languages. Empty list. */
3231 ssh2_pkt_addstring_start();
3232 /* List server->client languages. Empty list. */
3233 ssh2_pkt_addstring_start();
3234 /* First KEX packet does _not_ follow, because we're not that brave. */
3235 ssh2_pkt_addbool(FALSE
);
3237 ssh2_pkt_adduint32(0);
3239 exhash
= exhashbase
;
3240 sha_string(&exhash
, pktout
.data
+ 5, pktout
.length
- 5);
3246 sha_string(&exhash
, pktin
.data
+ 5, pktin
.length
- 5);
3249 * Now examine the other side's KEXINIT to see what we're up
3252 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
3253 bombout(("expected key exchange packet from server"));
3258 cscipher_tobe
= NULL
;
3259 sccipher_tobe
= NULL
;
3264 pktin
.savedpos
+= 16; /* skip garbage cookie */
3265 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
3266 for (i
= 0; i
< lenof(kex_algs
); i
++) {
3267 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
3272 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
3273 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
3274 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
3275 hostkey
= hostkey_algs
[i
];
3279 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
3281 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3282 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3286 for (j
= 0; j
< c
->nciphers
; j
++) {
3287 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3288 cscipher_tobe
= c
->list
[j
];
3293 if (cscipher_tobe
) {
3295 askcipher(cscipher_tobe
->name
, 1);
3299 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
3301 for (i
= 0; i
< n_preferred_ciphers
; i
++) {
3302 const struct ssh2_ciphers
*c
= preferred_ciphers
[i
];
3306 for (j
= 0; j
< c
->nciphers
; j
++) {
3307 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
3308 sccipher_tobe
= c
->list
[j
];
3313 if (sccipher_tobe
) {
3315 askcipher(sccipher_tobe
->name
, 2);
3319 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
3320 for (i
= 0; i
< nmacs
; i
++) {
3321 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3322 csmac_tobe
= maclist
[i
];
3326 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
3327 for (i
= 0; i
< nmacs
; i
++) {
3328 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
3329 scmac_tobe
= maclist
[i
];
3333 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
3334 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3335 const struct ssh_compress
*c
=
3336 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3337 if (in_commasep_string(c
->name
, str
, len
)) {
3342 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
3343 for (i
= 0; i
< lenof(compressions
) + 1; i
++) {
3344 const struct ssh_compress
*c
=
3345 i
== 0 ? preferred_comp
: compressions
[i
- 1];
3346 if (in_commasep_string(c
->name
, str
, len
)) {
3353 * Work out the number of bits of key we will need from the key
3354 * exchange. We start with the maximum key length of either
3360 csbits
= cscipher_tobe
->keylen
;
3361 scbits
= sccipher_tobe
->keylen
;
3362 nbits
= (csbits
> scbits ? csbits
: scbits
);
3364 /* The keys only have 160-bit entropy, since they're based on
3365 * a SHA-1 hash. So cap the key size at 160 bits. */
3370 * If we're doing Diffie-Hellman group exchange, start by
3371 * requesting a group.
3373 if (kex
== &ssh_diffiehellman_gex
) {
3374 logevent("Doing Diffie-Hellman group exchange");
3376 * Work out how big a DH group we will need to allow that
3379 pbits
= 512 << ((nbits
- 1) / 64);
3380 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
3381 ssh2_pkt_adduint32(pbits
);
3385 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
3386 bombout(("expected key exchange group packet from server"));
3389 p
= ssh2_pkt_getmp();
3390 g
= ssh2_pkt_getmp();
3391 dh_setup_group(p
, g
);
3392 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
3393 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
3396 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
3397 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
3400 logevent("Doing Diffie-Hellman key exchange");
3402 * Now generate and send e for Diffie-Hellman.
3404 e
= dh_create_e(nbits
* 2);
3405 ssh2_pkt_init(kex_init_value
);
3410 if (pktin
.type
!= kex_reply_value
) {
3411 bombout(("expected key exchange reply packet from server"));
3414 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
3415 f
= ssh2_pkt_getmp();
3416 ssh2_pkt_getstring(&sigdata
, &siglen
);
3420 sha_string(&exhash
, hostkeydata
, hostkeylen
);
3421 if (kex
== &ssh_diffiehellman_gex
) {
3422 sha_uint32(&exhash
, pbits
);
3423 sha_mpint(&exhash
, p
);
3424 sha_mpint(&exhash
, g
);
3426 sha_mpint(&exhash
, e
);
3427 sha_mpint(&exhash
, f
);
3428 sha_mpint(&exhash
, K
);
3429 SHA_Final(&exhash
, exchange_hash
);
3434 debug(("Exchange hash is:\n"));
3435 dmemdump(exchange_hash
, 20);
3438 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
3440 !hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
3441 bombout(("Server's host key did not match the signature supplied"));
3446 * Expect SSH2_MSG_NEWKEYS from server.
3449 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
3450 bombout(("expected new-keys packet from server"));
3455 * Authenticate remote host: verify host key. (We've already
3456 * checked the signature of the exchange hash.)
3458 keystr
= hostkey
->fmtkey(hkey
);
3459 fingerprint
= hostkey
->fingerprint(hkey
);
3460 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
3461 keystr
, fingerprint
);
3462 if (first_kex
) { /* don't bother logging this in rekeys */
3463 logevent("Host key fingerprint is:");
3464 logevent(fingerprint
);
3468 hostkey
->freekey(hkey
);
3471 * Send SSH2_MSG_NEWKEYS.
3473 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
3477 * Create and initialise session keys.
3479 cscipher
= cscipher_tobe
;
3480 sccipher
= sccipher_tobe
;
3483 cscomp
= cscomp_tobe
;
3484 sccomp
= sccomp_tobe
;
3485 cscomp
->compress_init();
3486 sccomp
->decompress_init();
3488 * Set IVs after keys. Here we use the exchange hash from the
3489 * _first_ key exchange.
3492 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
3493 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
3494 cscipher
->setcskey(keyspace
);
3495 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
3496 sccipher
->setsckey(keyspace
);
3497 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
3498 cscipher
->setcsiv(keyspace
);
3499 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
3500 sccipher
->setsciv(keyspace
);
3501 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
3502 csmac
->setcskey(keyspace
);
3503 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
3504 scmac
->setsckey(keyspace
);
3507 * If this is the first key exchange phase, we must pass the
3508 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
3509 * wants to see it but because it will need time to initialise
3510 * itself before it sees an actual packet. In subsequent key
3511 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
3512 * it would only confuse the layer above.
3520 * Now we're encrypting. Begin returning 1 to the protocol main
3521 * function so that other things can run on top of the
3522 * transport. If we ever see a KEXINIT, we must go back to the
3525 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
3528 logevent("Server initiated key re-exchange");
3529 goto begin_key_exchange
;
3535 * Add data to an SSH2 channel output buffer.
3537 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
,
3540 bufchain_add(&c
->v
.v2
.outbuffer
, buf
, len
);
3544 * Attempt to send data on an SSH2 channel.
3546 static int ssh2_try_send(struct ssh_channel
*c
)
3548 while (c
->v
.v2
.remwindow
> 0 && bufchain_size(&c
->v
.v2
.outbuffer
) > 0) {
3551 bufchain_prefix(&c
->v
.v2
.outbuffer
, &data
, &len
);
3552 if ((unsigned)len
> c
->v
.v2
.remwindow
)
3553 len
= c
->v
.v2
.remwindow
;
3554 if ((unsigned)len
> c
->v
.v2
.remmaxpkt
)
3555 len
= c
->v
.v2
.remmaxpkt
;
3556 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
3557 ssh2_pkt_adduint32(c
->remoteid
);
3558 ssh2_pkt_addstring_start();
3559 ssh2_pkt_addstring_data(data
, len
);
3561 bufchain_consume(&c
->v
.v2
.outbuffer
, len
);
3562 c
->v
.v2
.remwindow
-= len
;
3566 * After having sent as much data as we can, return the amount
3569 return bufchain_size(&c
->v
.v2
.outbuffer
);
3573 * Potentially enlarge the window on an SSH2 channel.
3575 static void ssh2_set_window(struct ssh_channel
*c
, unsigned newwin
)
3577 if (newwin
> c
->v
.v2
.locwindow
) {
3578 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3579 ssh2_pkt_adduint32(c
->remoteid
);
3580 ssh2_pkt_adduint32(newwin
- c
->v
.v2
.locwindow
);
3582 c
->v
.v2
.locwindow
= newwin
;
3587 * Handle the SSH2 userauth and connection layers.
3589 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
3592 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
,
3594 AUTH_KEYBOARD_INTERACTIVE
3598 AUTH_TYPE_PUBLICKEY
,
3599 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
3600 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
3602 AUTH_TYPE_KEYBOARD_INTERACTIVE
,
3603 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
3605 static int gotit
, need_pw
, can_pubkey
, can_passwd
, can_keyb_inter
;
3606 static int tried_pubkey_config
, tried_agent
, tried_keyb_inter
;
3607 static int kbd_inter_running
;
3608 static int we_are_in
;
3609 static int num_prompts
, echo
;
3610 static char username
[100];
3611 static char pwprompt
[200];
3612 static char password
[100];
3617 * Request userauth protocol, and await a response to it.
3619 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
3620 ssh2_pkt_addstring("ssh-userauth");
3622 crWaitUntilV(ispkt
);
3623 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
3624 bombout(("Server refused user authentication protocol"));
3629 * We repeat this whole loop, including the username prompt,
3630 * until we manage a successful authentication. If the user
3631 * types the wrong _password_, they are sent back to the
3632 * beginning to try another username. (If they specify a
3633 * username in the config, they are never asked, even if they
3634 * do give a wrong password.)
3636 * I think this best serves the needs of
3638 * - the people who have no configuration, no keys, and just
3639 * want to try repeated (username,password) pairs until they
3640 * type both correctly
3642 * - people who have keys and configuration but occasionally
3643 * need to fall back to passwords
3645 * - people with a key held in Pageant, who might not have
3646 * logged in to a particular machine before; so they want to
3647 * type a username, and then _either_ their key will be
3648 * accepted, _or_ they will type a password. If they mistype
3649 * the username they will want to be able to get back and
3660 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
3662 if (!ssh_get_line("login as: ",
3663 username
, sizeof(username
), FALSE
)) {
3665 * get_line failed to get a username.
3668 logevent("No username provided. Abandoning session.");
3669 ssh_state
= SSH_STATE_CLOSED
;
3673 c_write_str("login as: ");
3676 crWaitUntilV(!ispkt
);
3678 switch (c
= *in
++) {
3687 c_write_str("\b \b");
3694 c_write_str("\b \b");
3704 if (((c
>= ' ' && c
<= '~') ||
3705 ((unsigned char) c
>= 160))
3706 && pos
< sizeof(username
)-1) {
3707 username
[pos
++] = c
;
3714 c_write_str("\r\n");
3715 username
[strcspn(username
, "\n\r")] = '\0';
3718 strncpy(username
, cfg
.username
, 99);
3719 username
[99] = '\0';
3720 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
3721 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
3727 * Send an authentication request using method "none": (a)
3728 * just in case it succeeds, and (b) so that we know what
3729 * authentication methods we can usefully try next.
3731 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3732 ssh2_pkt_addstring(username
);
3733 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3734 ssh2_pkt_addstring("none"); /* method */
3736 type
= AUTH_TYPE_NONE
;
3740 tried_pubkey_config
= FALSE
;
3741 tried_agent
= FALSE
;
3742 tried_keyb_inter
= FALSE
;
3743 kbd_inter_running
= FALSE
;
3747 * Wait for the result of the last authentication request.
3750 crWaitUntilV(ispkt
);
3751 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
3755 * Don't show the banner if we're operating in
3756 * non-verbose non-interactive mode. (It's probably
3757 * a script, which means nobody will read the
3758 * banner _anyway_, and moreover the printing of
3759 * the banner will screw up processing on the
3760 * output of (say) plink.)
3762 if (flags
& (FLAG_VERBOSE
| FLAG_INTERACTIVE
)) {
3763 ssh2_pkt_getstring(&banner
, &size
);
3765 c_write_untrusted(banner
, size
);
3767 crWaitUntilV(ispkt
);
3769 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
3770 logevent("Access granted");
3775 if (kbd_inter_running
&&
3776 pktin
.type
== SSH2_MSG_USERAUTH_INFO_REQUEST
) {
3778 * This is a further prompt in keyboard-interactive
3779 * authentication. Do nothing.
3781 } else if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
3782 bombout(("Strange packet received during authentication: type %d",
3790 * OK, we're now sitting on a USERAUTH_FAILURE message, so
3791 * we can look at the string in it and know what we can
3792 * helpfully try next.
3794 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
) {
3797 ssh2_pkt_getstring(&methods
, &methlen
);
3798 kbd_inter_running
= FALSE
;
3799 if (!ssh2_pkt_getbool()) {
3801 * We have received an unequivocal Access
3802 * Denied. This can translate to a variety of
3805 * - if we'd just tried "none" authentication,
3806 * it's not worth printing anything at all
3808 * - if we'd just tried a public key _offer_,
3809 * the message should be "Server refused our
3810 * key" (or no message at all if the key
3811 * came from Pageant)
3813 * - if we'd just tried anything else, the
3814 * message really should be "Access denied".
3816 * Additionally, if we'd just tried password
3817 * authentication, we should break out of this
3818 * whole loop so as to go back to the username
3821 if (type
== AUTH_TYPE_NONE
) {
3823 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
3824 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
3825 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
3826 c_write_str("Server refused our key\r\n");
3827 logevent("Server refused public key");
3828 } else if (type
== AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
) {
3829 /* server declined keyboard-interactive; ignore */
3831 c_write_str("Access denied\r\n");
3832 logevent("Access denied");
3833 if (type
== AUTH_TYPE_PASSWORD
) {
3839 c_write_str("Further authentication required\r\n");
3840 logevent("Further authentication required");
3844 in_commasep_string("publickey", methods
, methlen
);
3846 in_commasep_string("password", methods
, methlen
);
3848 in_commasep_string("keyboard-interactive", methods
, methlen
);
3853 if (!method
&& can_pubkey
&& agent_exists() && !tried_agent
) {
3855 * Attempt public-key authentication using Pageant.
3857 static unsigned char request
[5], *response
, *p
;
3858 static int responselen
;
3859 static int i
, nkeys
;
3860 static int authed
= FALSE
;
3865 logevent("Pageant is running. Requesting keys.");
3867 /* Request the keys held by the agent. */
3868 PUT_32BIT(request
, 1);
3869 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
3870 agent_query(request
, 5, &r
, &responselen
);
3871 response
= (unsigned char *) r
;
3872 if (response
&& responselen
>= 5 &&
3873 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
3875 nkeys
= GET_32BIT(p
);
3879 sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
3882 for (i
= 0; i
< nkeys
; i
++) {
3883 static char *pkblob
, *alg
, *commentp
;
3884 static int pklen
, alglen
, commentlen
;
3885 static int siglen
, retlen
, len
;
3886 static char *q
, *agentreq
, *ret
;
3891 sprintf(buf
, "Trying Pageant key #%d", i
);
3894 pklen
= GET_32BIT(p
);
3898 alglen
= GET_32BIT(pkblob
);
3900 commentlen
= GET_32BIT(p
);
3904 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3905 ssh2_pkt_addstring(username
);
3906 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3907 ssh2_pkt_addstring("publickey"); /* method */
3908 ssh2_pkt_addbool(FALSE
); /* no signature included */
3909 ssh2_pkt_addstring_start();
3910 ssh2_pkt_addstring_data(alg
, alglen
);
3911 ssh2_pkt_addstring_start();
3912 ssh2_pkt_addstring_data(pkblob
, pklen
);
3915 crWaitUntilV(ispkt
);
3916 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
3917 logevent("Key refused");
3921 if (flags
& FLAG_VERBOSE
) {
3923 ("Authenticating with public key \"");
3924 c_write(commentp
, commentlen
);
3925 c_write_str("\" from agent\r\n");
3929 * Server is willing to accept the key.
3930 * Construct a SIGN_REQUEST.
3932 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3933 ssh2_pkt_addstring(username
);
3934 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3935 ssh2_pkt_addstring("publickey"); /* method */
3936 ssh2_pkt_addbool(TRUE
);
3937 ssh2_pkt_addstring_start();
3938 ssh2_pkt_addstring_data(alg
, alglen
);
3939 ssh2_pkt_addstring_start();
3940 ssh2_pkt_addstring_data(pkblob
, pklen
);
3942 siglen
= pktout
.length
- 5 + 4 + 20;
3943 len
= 1; /* message type */
3944 len
+= 4 + pklen
; /* key blob */
3945 len
+= 4 + siglen
; /* data to sign */
3946 len
+= 4; /* flags */
3947 agentreq
= smalloc(4 + len
);
3948 PUT_32BIT(agentreq
, len
);
3950 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
3951 PUT_32BIT(q
, pklen
);
3953 memcpy(q
, pkblob
, pklen
);
3955 PUT_32BIT(q
, siglen
);
3957 /* Now the data to be signed... */
3960 memcpy(q
, ssh2_session_id
, 20);
3962 memcpy(q
, pktout
.data
+ 5, pktout
.length
- 5);
3963 q
+= pktout
.length
- 5;
3964 /* And finally the (zero) flags word. */
3966 agent_query(agentreq
, len
+ 4, &vret
, &retlen
);
3970 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
3971 logevent("Sending Pageant's response");
3972 ssh2_pkt_addstring_start();
3973 ssh2_pkt_addstring_data(ret
+ 9,
3981 ("Pageant failed to answer challenge");
3991 if (!method
&& can_pubkey
&& *cfg
.keyfile
3992 && !tried_pubkey_config
) {
3993 unsigned char *pub_blob
;
3994 char *algorithm
, *comment
;
3997 tried_pubkey_config
= TRUE
;
4000 * Try the public key supplied in the configuration.
4002 * First, offer the public blob to see if the server is
4003 * willing to accept it.
4005 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
4008 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4009 ssh2_pkt_addstring(username
);
4010 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4011 ssh2_pkt_addstring("publickey"); /* method */
4012 ssh2_pkt_addbool(FALSE
); /* no signature included */
4013 ssh2_pkt_addstring(algorithm
);
4014 ssh2_pkt_addstring_start();
4015 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
4017 logevent("Offered public key"); /* FIXME */
4019 crWaitUntilV(ispkt
);
4020 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
4022 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
4023 continue; /* key refused; give up on it */
4026 logevent("Offer of public key accepted");
4028 * Actually attempt a serious authentication using
4031 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
4033 "Passphrase for key \"%.100s\": ",
4039 c_write_str("Authenticating with public key \"");
4040 c_write_str(comment
);
4041 c_write_str("\"\r\n");
4042 method
= AUTH_PUBLICKEY_FILE
;
4046 if (!method
&& can_keyb_inter
&& !tried_keyb_inter
) {
4047 method
= AUTH_KEYBOARD_INTERACTIVE
;
4048 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4049 tried_keyb_inter
= TRUE
;
4051 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4052 ssh2_pkt_addstring(username
);
4053 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4054 ssh2_pkt_addstring("keyboard-interactive"); /* method */
4055 ssh2_pkt_addstring(""); /* lang */
4056 ssh2_pkt_addstring("");
4059 crWaitUntilV(ispkt
);
4060 if (pktin
.type
!= SSH2_MSG_USERAUTH_INFO_REQUEST
) {
4061 if (pktin
.type
== SSH2_MSG_USERAUTH_FAILURE
)
4063 logevent("Keyboard-interactive authentication refused");
4064 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
;
4068 kbd_inter_running
= TRUE
;
4071 if (kbd_inter_running
) {
4072 method
= AUTH_KEYBOARD_INTERACTIVE
;
4073 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4074 tried_keyb_inter
= TRUE
;
4076 /* We've got packet with that "interactive" info
4077 dump banners, and set its prompt as ours */
4079 char *name
, *inst
, *lang
, *prompt
;
4080 int name_len
, inst_len
, lang_len
, prompt_len
;
4081 ssh2_pkt_getstring(&name
, &name_len
);
4082 ssh2_pkt_getstring(&inst
, &inst_len
);
4083 ssh2_pkt_getstring(&lang
, &lang_len
);
4085 c_write_untrusted(name
, name_len
);
4087 c_write_untrusted(inst
, inst_len
);
4088 num_prompts
= ssh2_pkt_getuint32();
4090 ssh2_pkt_getstring(&prompt
, &prompt_len
);
4091 strncpy(pwprompt
, prompt
, sizeof(pwprompt
));
4094 echo
= ssh2_pkt_getbool();
4098 if (!method
&& can_passwd
) {
4099 method
= AUTH_PASSWORD
;
4100 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
,
4107 if (!ssh_get_line(pwprompt
, password
,
4108 sizeof(password
), TRUE
)) {
4110 * get_line failed to get a password (for
4111 * example because one was supplied on the
4112 * command line which has already failed to
4115 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4116 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4118 ("No more passwords available to try");
4119 ssh2_pkt_addstring("en"); /* language tag */
4121 connection_fatal("Unable to authenticate");
4122 ssh_state
= SSH_STATE_CLOSED
;
4129 c_write_untrusted(pwprompt
, strlen(pwprompt
));
4134 crWaitUntilV(!ispkt
);
4136 switch (c
= *in
++) {
4157 if (pos
< sizeof(password
)-1)
4158 password
[pos
++] = c
;
4162 c_write_str("\r\n");
4166 if (method
== AUTH_PUBLICKEY_FILE
) {
4168 * We have our passphrase. Now try the actual authentication.
4170 struct ssh2_userkey
*key
;
4172 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
4173 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
4174 if (key
== SSH2_WRONG_PASSPHRASE
) {
4175 c_write_str("Wrong passphrase\r\n");
4176 tried_pubkey_config
= FALSE
;
4178 c_write_str("Unable to load private key\r\n");
4179 tried_pubkey_config
= TRUE
;
4181 /* Send a spurious AUTH_NONE to return to the top. */
4182 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4183 ssh2_pkt_addstring(username
);
4184 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4185 ssh2_pkt_addstring("none"); /* method */
4187 type
= AUTH_TYPE_NONE
;
4189 unsigned char *blob
, *sigdata
;
4190 int blob_len
, sigdata_len
;
4193 * We have loaded the private key and the server
4194 * has announced that it's willing to accept it.
4195 * Hallelujah. Generate a signature and send it.
4197 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4198 ssh2_pkt_addstring(username
);
4199 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4200 ssh2_pkt_addstring("publickey"); /* method */
4201 ssh2_pkt_addbool(TRUE
);
4202 ssh2_pkt_addstring(key
->alg
->name
);
4203 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
4204 ssh2_pkt_addstring_start();
4205 ssh2_pkt_addstring_data(blob
, blob_len
);
4209 * The data to be signed is:
4213 * followed by everything so far placed in the
4216 sigdata_len
= pktout
.length
- 5 + 4 + 20;
4217 sigdata
= smalloc(sigdata_len
);
4218 PUT_32BIT(sigdata
, 20);
4219 memcpy(sigdata
+ 4, ssh2_session_id
, 20);
4220 memcpy(sigdata
+ 24, pktout
.data
+ 5,
4223 key
->alg
->sign(key
->data
, sigdata
, sigdata_len
,
4225 ssh2_pkt_addstring_start();
4226 ssh2_pkt_addstring_data(blob
, blob_len
);
4231 type
= AUTH_TYPE_PUBLICKEY
;
4233 } else if (method
== AUTH_PASSWORD
) {
4235 * We send the password packet lumped tightly together with
4236 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4237 * string long enough to make the total length of the two
4238 * packets constant. This should ensure that a passive
4239 * listener doing traffic analyis can't work out the length
4242 * For this to work, we need an assumption about the
4243 * maximum length of the password packet. I think 256 is
4244 * pretty conservative. Anyone using a password longer than
4245 * that probably doesn't have much to worry about from
4246 * people who find out how long their password is!
4248 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
4249 ssh2_pkt_addstring(username
);
4250 ssh2_pkt_addstring("ssh-connection"); /* service requested */
4251 ssh2_pkt_addstring("password");
4252 ssh2_pkt_addbool(FALSE
);
4253 ssh2_pkt_addstring(password
);
4256 * We'll include a string that's an exact multiple of the
4257 * cipher block size. If the cipher is NULL for some
4258 * reason, we don't do this trick at all because we gain
4264 stringlen
= (256 - deferred_len
);
4265 stringlen
+= cscipher
->blksize
- 1;
4266 stringlen
-= (stringlen
% cscipher
->blksize
);
4269 * Temporarily disable actual compression,
4270 * so we can guarantee to get this string
4271 * exactly the length we want it. The
4272 * compression-disabling routine should
4273 * return an integer indicating how many
4274 * bytes we should adjust our string length
4277 stringlen
-= cscomp
->disable_compression();
4279 ssh2_pkt_init(SSH2_MSG_IGNORE
);
4280 ssh2_pkt_addstring_start();
4281 for (i
= 0; i
< stringlen
; i
++) {
4282 char c
= (char) random_byte();
4283 ssh2_pkt_addstring_data(&c
, 1);
4287 ssh_pkt_defersend();
4288 logevent("Sent password");
4289 type
= AUTH_TYPE_PASSWORD
;
4290 } else if (method
== AUTH_KEYBOARD_INTERACTIVE
) {
4291 ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE
);
4292 ssh2_pkt_adduint32(num_prompts
);
4293 ssh2_pkt_addstring(password
);
4294 memset(password
, 0, sizeof(password
));
4296 type
= AUTH_TYPE_KEYBOARD_INTERACTIVE
;
4299 ("No supported authentication methods left to try!\r\n");
4301 ("No supported authentications offered. Disconnecting");
4302 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4303 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4305 ("No supported authentication methods available");
4306 ssh2_pkt_addstring("en"); /* language tag */
4308 ssh_state
= SSH_STATE_CLOSED
;
4312 } while (!we_are_in
);
4315 * Now we're authenticated for the connection protocol. The
4316 * connection protocol will automatically have started at this
4317 * point; there's no need to send SERVICE_REQUEST.
4321 * So now create a channel with a session in it.
4323 ssh_channels
= newtree234(ssh_channelcmp
);
4324 mainchan
= smalloc(sizeof(struct ssh_channel
));
4325 mainchan
->localid
= alloc_channel_id();
4326 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
4327 ssh2_pkt_addstring("session");
4328 ssh2_pkt_adduint32(mainchan
->localid
);
4329 mainchan
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4330 ssh2_pkt_adduint32(mainchan
->v
.v2
.locwindow
); /* our window size */
4331 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4333 crWaitUntilV(ispkt
);
4334 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4335 bombout(("Server refused to open a session"));
4337 /* FIXME: error data comes back in FAILURE packet */
4339 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
4340 bombout(("Server's channel confirmation cited wrong channel"));
4343 mainchan
->remoteid
= ssh2_pkt_getuint32();
4344 mainchan
->type
= CHAN_MAINSESSION
;
4345 mainchan
->closes
= 0;
4346 mainchan
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4347 mainchan
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4348 bufchain_init(&mainchan
->v
.v2
.outbuffer
);
4349 add234(ssh_channels
, mainchan
);
4350 logevent("Opened channel for session");
4353 * Potentially enable X11 forwarding.
4355 if (cfg
.x11_forward
) {
4356 char proto
[20], data
[64];
4357 logevent("Requesting X11 forwarding");
4358 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
4359 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4360 ssh2_pkt_adduint32(mainchan
->remoteid
);
4361 ssh2_pkt_addstring("x11-req");
4362 ssh2_pkt_addbool(1); /* want reply */
4363 ssh2_pkt_addbool(0); /* many connections */
4364 ssh2_pkt_addstring(proto
);
4365 ssh2_pkt_addstring(data
);
4366 ssh2_pkt_adduint32(0); /* screen number */
4370 crWaitUntilV(ispkt
);
4371 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4372 unsigned i
= ssh2_pkt_getuint32();
4373 struct ssh_channel
*c
;
4374 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4376 continue; /* nonexistent channel */
4377 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4379 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4381 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4382 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4383 bombout(("Server got confused by X11 forwarding request"));
4386 logevent("X11 forwarding refused");
4388 logevent("X11 forwarding enabled");
4389 ssh_X11_fwd_enabled
= TRUE
;
4394 * Enable port forwardings.
4397 static char *e
; /* preserve across crReturn */
4401 char sports
[256], dports
[256], host
[256];
4404 ssh_rportfwds
= newtree234(ssh_rportcmp_ssh2
);
4405 /* Add port forwardings. */
4410 while (*e
&& *e
!= '\t')
4416 while (*e
&& *e
!= ':')
4426 dport
= atoi(dports
);
4427 sport
= atoi(sports
);
4428 if (sport
&& dport
) {
4430 pfd_addforward(host
, dport
, sport
);
4431 sprintf(buf
, "Local port %d forwarding to %s:%d",
4432 sport
, host
, dport
);
4435 struct ssh_rportfwd
*pf
;
4436 pf
= smalloc(sizeof(*pf
));
4437 strcpy(pf
->dhost
, host
);
4440 if (add234(ssh_rportfwds
, pf
) != pf
) {
4442 "Duplicate remote port forwarding to %s:%d",
4447 sprintf(buf
, "Requesting remote port %d (forwarded to %s:%d)",
4448 sport
, host
, dport
);
4450 ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST
);
4451 ssh2_pkt_addstring("tcpip-forward");
4452 ssh2_pkt_addbool(1);/* want reply */
4453 ssh2_pkt_addstring("127.0.0.1");
4454 ssh2_pkt_adduint32(sport
);
4458 crWaitUntilV(ispkt
);
4459 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4460 unsigned i
= ssh2_pkt_getuint32();
4461 struct ssh_channel
*c
;
4462 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4464 continue;/* nonexistent channel */
4465 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4467 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4469 if (pktin
.type
!= SSH2_MSG_REQUEST_SUCCESS
) {
4470 if (pktin
.type
!= SSH2_MSG_REQUEST_FAILURE
) {
4471 bombout(("Server got confused by port forwarding request"));
4474 logevent("Server refused this port forwarding");
4476 logevent("Remote port forwarding enabled");
4485 * Potentially enable agent forwarding.
4487 if (cfg
.agentfwd
&& agent_exists()) {
4488 logevent("Requesting OpenSSH-style agent forwarding");
4489 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4490 ssh2_pkt_adduint32(mainchan
->remoteid
);
4491 ssh2_pkt_addstring("auth-agent-req@openssh.com");
4492 ssh2_pkt_addbool(1); /* want reply */
4496 crWaitUntilV(ispkt
);
4497 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4498 unsigned i
= ssh2_pkt_getuint32();
4499 struct ssh_channel
*c
;
4500 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4502 continue; /* nonexistent channel */
4503 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4505 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4507 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4508 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4510 ("Server got confused by agent forwarding request"));
4513 logevent("Agent forwarding refused");
4515 logevent("Agent forwarding enabled");
4516 ssh_agentfwd_enabled
= TRUE
;
4521 * Now allocate a pty for the session.
4524 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4525 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4526 ssh2_pkt_addstring("pty-req");
4527 ssh2_pkt_addbool(1); /* want reply */
4528 ssh2_pkt_addstring(cfg
.termtype
);
4529 ssh2_pkt_adduint32(cols
);
4530 ssh2_pkt_adduint32(rows
);
4531 ssh2_pkt_adduint32(0); /* pixel width */
4532 ssh2_pkt_adduint32(0); /* pixel height */
4533 ssh2_pkt_addstring_start();
4534 ssh2_pkt_addstring_data("\0", 1); /* TTY_OP_END, no special options */
4536 ssh_state
= SSH_STATE_INTERMED
;
4539 crWaitUntilV(ispkt
);
4540 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4541 unsigned i
= ssh2_pkt_getuint32();
4542 struct ssh_channel
*c
;
4543 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4545 continue; /* nonexistent channel */
4546 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4548 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4550 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4551 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4552 bombout(("Server got confused by pty request"));
4555 c_write_str("Server refused to allocate pty\r\n");
4556 ssh_editing
= ssh_echoing
= 1;
4558 logevent("Allocated pty");
4561 ssh_editing
= ssh_echoing
= 1;
4565 * Start a shell or a remote command. We may have to attempt
4566 * this twice if the config data has provided a second choice
4573 if (ssh_fallback_cmd
) {
4574 subsys
= cfg
.ssh_subsys2
;
4575 cmd
= cfg
.remote_cmd_ptr2
;
4577 subsys
= cfg
.ssh_subsys
;
4578 cmd
= cfg
.remote_cmd_ptr
;
4581 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
4582 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
4584 ssh2_pkt_addstring("subsystem");
4585 ssh2_pkt_addbool(1); /* want reply */
4586 ssh2_pkt_addstring(cmd
);
4588 ssh2_pkt_addstring("exec");
4589 ssh2_pkt_addbool(1); /* want reply */
4590 ssh2_pkt_addstring(cmd
);
4592 ssh2_pkt_addstring("shell");
4593 ssh2_pkt_addbool(1); /* want reply */
4597 crWaitUntilV(ispkt
);
4598 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4599 unsigned i
= ssh2_pkt_getuint32();
4600 struct ssh_channel
*c
;
4601 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4603 continue; /* nonexistent channel */
4604 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4606 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
4607 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
4608 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
4609 bombout(("Server got confused by shell/command request"));
4613 * We failed to start the command. If this is the
4614 * fallback command, we really are finished; if it's
4615 * not, and if the fallback command exists, try falling
4616 * back to it before complaining.
4618 if (!ssh_fallback_cmd
&& cfg
.remote_cmd_ptr2
!= NULL
) {
4619 logevent("Primary command failed; attempting fallback");
4620 ssh_fallback_cmd
= TRUE
;
4623 bombout(("Server refused to start a shell/command"));
4626 logevent("Started a shell/command");
4631 ssh_state
= SSH_STATE_SESSION
;
4635 ssh_special(TS_EOF
);
4640 ldisc_send(NULL
, 0); /* cause ldisc to notice changes */
4643 static int try_send
;
4647 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
4648 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
4651 unsigned i
= ssh2_pkt_getuint32();
4652 struct ssh_channel
*c
;
4653 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4655 continue; /* nonexistent channel */
4656 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
4657 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
4658 continue; /* extended but not stderr */
4659 ssh2_pkt_getstring(&data
, &length
);
4662 c
->v
.v2
.locwindow
-= length
;
4664 case CHAN_MAINSESSION
:
4666 from_backend(pktin
.type
==
4667 SSH2_MSG_CHANNEL_EXTENDED_DATA
,
4671 bufsize
= x11_send(c
->u
.x11
.s
, data
, length
);
4674 bufsize
= pfd_send(c
->u
.pfd
.s
, data
, length
);
4677 while (length
> 0) {
4678 if (c
->u
.a
.lensofar
< 4) {
4679 int l
= min(4 - c
->u
.a
.lensofar
, length
);
4680 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
,
4684 c
->u
.a
.lensofar
+= l
;
4686 if (c
->u
.a
.lensofar
== 4) {
4688 4 + GET_32BIT(c
->u
.a
.msglen
);
4689 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
4690 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
4692 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
4694 min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
4696 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
,
4700 c
->u
.a
.lensofar
+= l
;
4702 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
4703 void *reply
, *sentreply
;
4705 agent_query(c
->u
.a
.message
,
4706 c
->u
.a
.totallen
, &reply
,
4711 /* Fake SSH_AGENT_FAILURE. */
4712 sentreply
= "\0\0\0\1\5";
4715 ssh2_add_channel_data(c
, sentreply
,
4720 sfree(c
->u
.a
.message
);
4721 c
->u
.a
.lensofar
= 0;
4728 * If we are not buffering too much data,
4729 * enlarge the window again at the remote side.
4731 if (bufsize
< OUR_V2_WINSIZE
)
4732 ssh2_set_window(c
, OUR_V2_WINSIZE
- bufsize
);
4734 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
4735 ssh_state
= SSH_STATE_CLOSED
;
4736 logevent("Received disconnect message");
4738 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
4739 continue; /* exit status et al; ignore (FIXME?) */
4740 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
4741 unsigned i
= ssh2_pkt_getuint32();
4742 struct ssh_channel
*c
;
4744 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4746 continue; /* nonexistent channel */
4748 if (c
->type
== CHAN_X11
) {
4750 * Remote EOF on an X11 channel means we should
4751 * wrap up and close the channel ourselves.
4753 x11_close(c
->u
.x11
.s
);
4755 } else if (c
->type
== CHAN_AGENT
) {
4757 } else if (c
->type
== CHAN_SOCKDATA
) {
4758 pfd_close(c
->u
.pfd
.s
);
4761 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
4762 unsigned i
= ssh2_pkt_getuint32();
4763 struct ssh_channel
*c
;
4765 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4767 continue; /* nonexistent channel */
4768 /* Do pre-close processing on the channel. */
4770 case CHAN_MAINSESSION
:
4771 break; /* nothing to see here, move along */
4773 if (c
->u
.x11
.s
!= NULL
)
4774 x11_close(c
->u
.x11
.s
);
4781 if (c
->u
.pfd
.s
!= NULL
)
4782 pfd_close(c
->u
.pfd
.s
);
4786 if (c
->closes
== 0) {
4787 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
4788 ssh2_pkt_adduint32(c
->remoteid
);
4791 del234(ssh_channels
, c
);
4792 bufchain_clear(&c
->v
.v2
.outbuffer
);
4796 * See if that was the last channel left open.
4798 if (count234(ssh_channels
) == 0) {
4799 logevent("All channels closed. Disconnecting");
4800 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
4801 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
4802 ssh2_pkt_addstring("All open channels closed");
4803 ssh2_pkt_addstring("en"); /* language tag */
4805 ssh_state
= SSH_STATE_CLOSED
;
4808 continue; /* remote sends close; ignore (FIXME) */
4809 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
4810 unsigned i
= ssh2_pkt_getuint32();
4811 struct ssh_channel
*c
;
4812 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4814 continue; /* nonexistent channel */
4815 c
->v
.v2
.remwindow
+= ssh2_pkt_getuint32();
4817 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
4818 unsigned i
= ssh2_pkt_getuint32();
4819 struct ssh_channel
*c
;
4820 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4822 continue; /* nonexistent channel */
4823 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4824 continue; /* dunno why they're confirming this */
4825 c
->remoteid
= ssh2_pkt_getuint32();
4826 c
->type
= CHAN_SOCKDATA
;
4828 c
->v
.v2
.remwindow
= ssh2_pkt_getuint32();
4829 c
->v
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
4830 bufchain_init(&c
->v
.v2
.outbuffer
);
4831 pfd_confirm(c
->u
.pfd
.s
);
4832 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN_FAILURE
) {
4833 unsigned i
= ssh2_pkt_getuint32();
4834 struct ssh_channel
*c
;
4835 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
4837 continue; /* nonexistent channel */
4838 if (c
->type
!= CHAN_SOCKDATA_DORMANT
)
4839 continue; /* dunno why they're failing this */
4841 logevent("Forwarded connection refused by server");
4843 pfd_close(c
->u
.pfd
.s
);
4845 del234(ssh_channels
, c
);
4847 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
4851 struct ssh_channel
*c
;
4852 unsigned remid
, winsize
, pktsize
;
4853 ssh2_pkt_getstring(&type
, &typelen
);
4854 c
= smalloc(sizeof(struct ssh_channel
));
4856 remid
= ssh2_pkt_getuint32();
4857 winsize
= ssh2_pkt_getuint32();
4858 pktsize
= ssh2_pkt_getuint32();
4860 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
4861 if (!ssh_X11_fwd_enabled
)
4862 error
= "X11 forwarding is not enabled";
4863 else if (x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) !=
4865 error
= "Unable to open an X11 connection";
4869 } else if (typelen
== 15 &&
4870 !memcmp(type
, "forwarded-tcpip", 15)) {
4871 struct ssh_rportfwd pf
, *realpf
;
4874 ssh2_pkt_getstring(&dummy
, &dummylen
);/* skip address */
4875 pf
.sport
= ssh2_pkt_getuint32();
4876 realpf
= find234(ssh_rportfwds
, &pf
, NULL
);
4877 if (realpf
== NULL
) {
4878 error
= "Remote port is not recognised";
4880 char *e
= pfd_newconnect(&c
->u
.pfd
.s
, realpf
->dhost
,
4883 sprintf(buf
, "Received remote port open request for %s:%d",
4884 realpf
->dhost
, realpf
->dport
);
4887 sprintf(buf
, "Port open failed: %s", e
);
4889 error
= "Port open failed";
4891 logevent("Forwarded port opened successfully");
4892 c
->type
= CHAN_SOCKDATA
;
4895 } else if (typelen
== 22 &&
4896 !memcmp(type
, "auth-agent@openssh.com", 3)) {
4897 if (!ssh_agentfwd_enabled
)
4898 error
= "Agent forwarding is not enabled";
4900 c
->type
= CHAN_AGENT
; /* identify channel type */
4901 c
->u
.a
.lensofar
= 0;
4904 error
= "Unsupported channel type requested";
4907 c
->remoteid
= remid
;
4909 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
4910 ssh2_pkt_adduint32(c
->remoteid
);
4911 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
4912 ssh2_pkt_addstring(error
);
4913 ssh2_pkt_addstring("en"); /* language tag */
4917 c
->localid
= alloc_channel_id();
4919 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
4920 c
->v
.v2
.remwindow
= winsize
;
4921 c
->v
.v2
.remmaxpkt
= pktsize
;
4922 bufchain_init(&c
->v
.v2
.outbuffer
);
4923 add234(ssh_channels
, c
);
4924 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
4925 ssh2_pkt_adduint32(c
->remoteid
);
4926 ssh2_pkt_adduint32(c
->localid
);
4927 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);
4928 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
4932 bombout(("Strange packet received: type %d", pktin
.type
));
4937 * We have spare data. Add it to the channel buffer.
4939 ssh2_add_channel_data(mainchan
, in
, inlen
);
4944 struct ssh_channel
*c
;
4946 * Try to send data on all channels if we can.
4948 for (i
= 0; NULL
!= (c
= index234(ssh_channels
, i
)); i
++) {
4949 int bufsize
= ssh2_try_send(c
);
4952 case CHAN_MAINSESSION
:
4953 /* stdin need not receive an unthrottle
4954 * notification since it will be polled */
4957 x11_unthrottle(c
->u
.x11
.s
);
4960 /* agent sockets are request/response and need no
4961 * buffer management */
4964 pfd_unthrottle(c
->u
.pfd
.s
);
4976 * Handle the top-level SSH2 protocol.
4978 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
4980 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
4982 do_ssh2_authconn(in
, inlen
, ispkt
);
4986 * Called to set up the connection.
4988 * Returns an error message, or NULL on success.
4990 static char *ssh_init(char *host
, int port
, char **realhost
)
4995 if (crypto_startup() == 0)
4996 return "Microsoft high encryption pack not installed!";
5002 ssh1_throttle_count
= 0;
5003 ssh_overall_bufsize
= 0;
5004 ssh_fallback_cmd
= 0;
5006 p
= connect_to_host(host
, port
, realhost
);
5014 * Called to send data down the Telnet connection.
5016 static int ssh_send(char *buf
, int len
)
5018 if (s
== NULL
|| ssh_protocol
== NULL
)
5021 ssh_protocol(buf
, len
, 0);
5023 return ssh_sendbuffer();
5027 * Called to query the current amount of buffered stdin data.
5029 static int ssh_sendbuffer(void)
5033 if (s
== NULL
|| ssh_protocol
== NULL
)
5037 * If the SSH socket itself has backed up, add the total backup
5038 * size on that to any individual buffer on the stdin channel.
5041 if (ssh_throttled_all
)
5042 override_value
= ssh_overall_bufsize
;
5044 if (ssh_version
== 1) {
5045 return override_value
;
5046 } else if (ssh_version
== 2) {
5047 if (!mainchan
|| mainchan
->closes
> 0)
5048 return override_value
;
5050 return override_value
+ bufchain_size(&mainchan
->v
.v2
.outbuffer
);
5057 * Called to set the size of the window from SSH's POV.
5059 static void ssh_size(void)
5061 switch (ssh_state
) {
5062 case SSH_STATE_BEFORE_SIZE
:
5063 case SSH_STATE_PREPACKET
:
5064 case SSH_STATE_CLOSED
:
5065 break; /* do nothing */
5066 case SSH_STATE_INTERMED
:
5067 size_needed
= TRUE
; /* buffer for later */
5069 case SSH_STATE_SESSION
:
5071 if (ssh_version
== 1) {
5072 send_packet(SSH1_CMSG_WINDOW_SIZE
,
5073 PKT_INT
, rows
, PKT_INT
, cols
,
5074 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
5076 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
5077 ssh2_pkt_adduint32(mainchan
->remoteid
);
5078 ssh2_pkt_addstring("window-change");
5079 ssh2_pkt_addbool(0);
5080 ssh2_pkt_adduint32(cols
);
5081 ssh2_pkt_adduint32(rows
);
5082 ssh2_pkt_adduint32(0);
5083 ssh2_pkt_adduint32(0);
5092 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5093 * can send an EOF and collect resulting output (e.g. `plink
5096 static void ssh_special(Telnet_Special code
)
5098 if (code
== TS_EOF
) {
5099 if (ssh_state
!= SSH_STATE_SESSION
) {
5101 * Buffer the EOF in case we are pre-SESSION, so we can
5102 * send it as soon as we reach SESSION.
5108 if (ssh_version
== 1) {
5109 send_packet(SSH1_CMSG_EOF
, PKT_END
);
5111 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
5112 ssh2_pkt_adduint32(mainchan
->remoteid
);
5115 logevent("Sent EOF message");
5116 } else if (code
== TS_PING
) {
5117 if (ssh_state
== SSH_STATE_CLOSED
5118 || ssh_state
== SSH_STATE_PREPACKET
) return;
5119 if (ssh_version
== 1) {
5120 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
5122 ssh2_pkt_init(SSH2_MSG_IGNORE
);
5123 ssh2_pkt_addstring_start();
5131 void *new_sock_channel(Socket s
)
5133 struct ssh_channel
*c
;
5134 c
= smalloc(sizeof(struct ssh_channel
));
5137 c
->remoteid
= -1; /* to be set when open confirmed */
5138 c
->localid
= alloc_channel_id();
5140 c
->type
= CHAN_SOCKDATA_DORMANT
;/* identify channel type */
5142 add234(ssh_channels
, c
);
5148 * This is called when stdout/stderr (the entity to which
5149 * from_backend sends data) manages to clear some backlog.
5151 void ssh_unthrottle(int bufsize
)
5153 if (ssh_version
== 1) {
5154 if (ssh1_stdout_throttling
&& bufsize
< SSH1_BUFFER_LIMIT
) {
5155 ssh1_stdout_throttling
= 0;
5159 if (mainchan
&& mainchan
->closes
== 0)
5160 ssh2_set_window(mainchan
, OUR_V2_WINSIZE
- bufsize
);
5164 void ssh_send_port_open(void *channel
, char *hostname
, int port
, char *org
)
5166 struct ssh_channel
*c
= (struct ssh_channel
*)channel
;
5169 sprintf(buf
, "Opening forwarded connection to %.512s:%d", hostname
, port
);
5172 if (ssh_version
== 1) {
5173 send_packet(SSH1_MSG_PORT_OPEN
,
5174 PKT_INT
, c
->localid
,
5177 //PKT_STR, <org:orgport>,
5180 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
5181 ssh2_pkt_addstring("direct-tcpip");
5182 ssh2_pkt_adduint32(c
->localid
);
5183 c
->v
.v2
.locwindow
= OUR_V2_WINSIZE
;
5184 ssh2_pkt_adduint32(c
->v
.v2
.locwindow
);/* our window size */
5185 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
5186 ssh2_pkt_addstring(hostname
);
5187 ssh2_pkt_adduint32(port
);
5189 * We make up values for the originator data; partly it's
5190 * too much hassle to keep track, and partly I'm not
5191 * convinced the server should be told details like that
5192 * about my local network configuration.
5194 ssh2_pkt_addstring("client-side-connection");
5195 ssh2_pkt_adduint32(0);
5201 static Socket
ssh_socket(void)
5206 static int ssh_sendok(void)
5211 static int ssh_ldisc(int option
)
5213 if (option
== LD_ECHO
)
5215 if (option
== LD_EDIT
)
5220 Backend ssh_backend
= {