18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 fprintf(stderr, "%s\n", s); }
22 #define bombout(msg) ( ssh_state = SSH_STATE_CLOSED, \
23 (s ? sk_close(s), s = NULL : 0), \
24 connection_fatal msg )
26 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
27 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
28 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
29 #define SSH1_CMSG_USER 4 /* 0x4 */
30 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
31 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
32 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
33 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
34 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
35 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
36 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
37 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
38 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
39 #define SSH1_SMSG_FAILURE 15 /* 0xf */
40 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
41 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
42 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
43 #define SSH1_CMSG_EOF 19 /* 0x13 */
44 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
45 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
46 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
47 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
48 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
49 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
50 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
51 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
52 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
53 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
54 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
55 #define SSH1_MSG_IGNORE 32 /* 0x20 */
56 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
57 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
58 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
59 #define SSH1_MSG_DEBUG 36 /* 0x24 */
60 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
61 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
62 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
63 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
64 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
65 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
66 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
68 #define SSH1_AUTH_TIS 5 /* 0x5 */
69 #define SSH1_AUTH_CCARD 16 /* 0x10 */
71 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
72 #define SSH2_MSG_IGNORE 2 /* 0x2 */
73 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
74 #define SSH2_MSG_DEBUG 4 /* 0x4 */
75 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
76 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
77 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
78 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
79 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
80 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
81 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
82 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
83 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
84 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
85 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
86 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
87 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
88 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
89 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
90 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
91 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
92 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
93 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
94 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
95 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
96 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
97 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
98 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
99 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
100 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
101 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
102 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
103 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
104 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
106 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
107 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
108 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
109 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
110 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
111 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
112 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
113 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
114 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
115 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
116 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
118 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
119 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
120 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
121 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
123 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
126 * Various remote-bug flags.
128 #define BUG_CHOKES_ON_SSH1_IGNORE 1
129 #define BUG_SSH2_HMAC 2
131 #define GET_32BIT(cp) \
132 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
133 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
134 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
135 ((unsigned long)(unsigned char)(cp)[3]))
137 #define PUT_32BIT(cp, value) { \
138 (cp)[0] = (unsigned char)((value) >> 24); \
139 (cp)[1] = (unsigned char)((value) >> 16); \
140 (cp)[2] = (unsigned char)((value) >> 8); \
141 (cp)[3] = (unsigned char)(value); }
143 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
145 /* Coroutine mechanics for the sillier bits of the code */
146 #define crBegin1 static int crLine = 0;
147 #define crBegin2 switch(crLine) { case 0:;
148 #define crBegin crBegin1; crBegin2;
149 #define crFinish(z) } crLine = 0; return (z)
150 #define crFinishV } crLine = 0; return
151 #define crReturn(z) \
153 crLine=__LINE__; return (z); case __LINE__:;\
157 crLine=__LINE__; return; case __LINE__:;\
159 #define crStop(z) do{ crLine = 0; return (z); }while(0)
160 #define crStopV do{ crLine = 0; return; }while(0)
161 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
162 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
164 extern char *x11_init (Socket
*, char *, void *);
165 extern void x11_close (Socket
);
166 extern void x11_send (Socket
, char *, int);
167 extern void x11_invent_auth(char *, int, char *, int);
170 * Ciphers for SSH2. We miss out single-DES because it isn't
171 * supported; also 3DES and Blowfish are both done differently from
172 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
173 * endianness and different-sized keys.)
175 const static struct ssh2_ciphers
*ciphers
[] = {
181 const static struct ssh_kex
*kex_algs
[] = {
182 &ssh_diffiehellman_gex
,
183 &ssh_diffiehellman
};
185 const static struct ssh_signkey
*hostkey_algs
[] = { &ssh_rsa
, &ssh_dss
};
187 static void nullmac_key(unsigned char *key
) { }
188 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
189 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
190 const static struct ssh_mac ssh_mac_none
= {
191 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
193 const static struct ssh_mac
*macs
[] = {
194 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
};
195 const static struct ssh_mac
*buggymacs
[] = {
196 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
};
198 static void ssh_comp_none_init(void) { }
199 static int ssh_comp_none_block(unsigned char *block
, int len
,
200 unsigned char **outblock
, int *outlen
) {
203 static int ssh_comp_none_disable(void) { return 0; }
204 const static struct ssh_compress ssh_comp_none
= {
206 ssh_comp_none_init
, ssh_comp_none_block
,
207 ssh_comp_none_init
, ssh_comp_none_block
,
208 ssh_comp_none_disable
210 extern const struct ssh_compress ssh_zlib
;
211 const static struct ssh_compress
*compressions
[] = {
212 &ssh_zlib
, &ssh_comp_none
};
214 enum { /* channel types */
221 * 2-3-4 tree storing channels.
224 unsigned remoteid
, localid
;
227 struct ssh2_data_channel
{
228 unsigned char *outbuffer
;
229 unsigned outbuflen
, outbufsize
;
230 unsigned remwindow
, remmaxpkt
;
233 struct ssh_agent_channel
{
234 unsigned char *message
;
235 unsigned char msglen
[4];
236 int lensofar
, totallen
;
238 struct ssh_x11_channel
{
253 static SHA_State exhash
, exhashbase
;
255 static Socket s
= NULL
;
257 static unsigned char session_key
[32];
258 static int ssh1_compressing
;
259 static int ssh_agentfwd_enabled
;
260 static int ssh_X11_fwd_enabled
;
261 static int ssh_remote_bugs
;
262 static const struct ssh_cipher
*cipher
= NULL
;
263 static const struct ssh2_cipher
*cscipher
= NULL
;
264 static const struct ssh2_cipher
*sccipher
= NULL
;
265 static const struct ssh_mac
*csmac
= NULL
;
266 static const struct ssh_mac
*scmac
= NULL
;
267 static const struct ssh_compress
*cscomp
= NULL
;
268 static const struct ssh_compress
*sccomp
= NULL
;
269 static const struct ssh_kex
*kex
= NULL
;
270 static const struct ssh_signkey
*hostkey
= NULL
;
271 static unsigned char ssh2_session_id
[20];
272 int (*ssh_get_line
)(const char *prompt
, char *str
, int maxlen
,
275 static char *savedhost
;
276 static int savedport
;
277 static int ssh_send_ok
;
278 static int ssh_echoing
, ssh_editing
;
280 static tree234
*ssh_channels
; /* indexed by local id */
281 static struct ssh_channel
*mainchan
; /* primary session channel */
285 SSH_STATE_BEFORE_SIZE
,
289 } ssh_state
= SSH_STATE_PREPACKET
;
291 static int size_needed
= FALSE
, eof_needed
= FALSE
;
293 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
294 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
295 static unsigned char *deferred_send_data
= NULL
;
296 static int deferred_len
= 0, deferred_size
= 0;
298 static int ssh_version
;
299 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
300 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
301 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
302 static void ssh_size(void);
303 static void ssh_special (Telnet_Special
);
304 static void ssh2_try_send(struct ssh_channel
*c
);
305 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
);
307 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
309 static struct rdpkt1_state_tag
{
310 long len
, pad
, biglen
, to_read
;
311 unsigned long realcrc
, gotcrc
;
317 static struct rdpkt2_state_tag
{
318 long len
, pad
, payload
, packetlen
, maclen
;
321 unsigned long incoming_sequence
;
324 static int ssh_channelcmp(void *av
, void *bv
) {
325 struct ssh_channel
*a
= (struct ssh_channel
*)av
;
326 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
327 if (a
->localid
< b
->localid
) return -1;
328 if (a
->localid
> b
->localid
) return +1;
331 static int ssh_channelfind(void *av
, void *bv
) {
332 unsigned *a
= (unsigned *)av
;
333 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
334 if (*a
< b
->localid
) return -1;
335 if (*a
> b
->localid
) return +1;
339 static void c_write (char *buf
, int len
) {
340 if ((flags
& FLAG_STDERR
)) {
342 for (i
= 0; i
< len
; i
++)
344 fputc(buf
[i
], stderr
);
347 from_backend(1, buf
, len
);
350 static void c_write_str (char *buf
) {
351 c_write(buf
, strlen(buf
));
355 * Collect incoming data in the incoming packet buffer.
356 * Decipher and verify the packet when it is completely read.
357 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
358 * Update the *data and *datalen variables.
359 * Return the additional nr of bytes needed, or 0 when
360 * a complete packet is available.
362 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
364 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
373 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
374 while ((*datalen
) == 0)
376 st
->len
= (st
->len
<< 8) + **data
;
377 (*data
)++, (*datalen
)--;
381 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
382 st
->len
= 0x300; /* big enough to carry to end */
386 st
->pad
= 8 - (st
->len
% 8);
387 st
->biglen
= st
->len
+ st
->pad
;
388 pktin
.length
= st
->len
- 5;
390 if (pktin
.maxlen
< st
->biglen
) {
391 pktin
.maxlen
= st
->biglen
;
392 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->biglen
+APIEXTRA
) :
393 srealloc(pktin
.data
, st
->biglen
+APIEXTRA
));
395 fatalbox("Out of memory");
398 st
->to_read
= st
->biglen
;
400 while (st
->to_read
> 0) {
401 st
->chunk
= st
->to_read
;
402 while ((*datalen
) == 0)
403 crReturn(st
->to_read
);
404 if (st
->chunk
> (*datalen
))
405 st
->chunk
= (*datalen
);
406 memcpy(st
->p
, *data
, st
->chunk
);
408 *datalen
-= st
->chunk
;
410 st
->to_read
-= st
->chunk
;
414 cipher
->decrypt(pktin
.data
, st
->biglen
);
416 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
417 for (st
->i
= 0; st
->i
< st
->biglen
; st
->i
++)
418 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
422 st
->realcrc
= crc32(pktin
.data
, st
->biglen
-4);
423 st
->gotcrc
= GET_32BIT(pktin
.data
+st
->biglen
-4);
424 if (st
->gotcrc
!= st
->realcrc
) {
425 bombout(("Incorrect CRC received on packet"));
429 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
431 if (ssh1_compressing
) {
432 unsigned char *decompblk
;
436 debug(("Packet payload pre-decompression:\n"));
437 for (i
= -1; i
< pktin
.length
; i
++)
438 debug((" %02x", (unsigned char)pktin
.body
[i
]));
441 zlib_decompress_block(pktin
.body
-1, pktin
.length
+1,
442 &decompblk
, &decomplen
);
444 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
445 pktin
.maxlen
= st
->pad
+ decomplen
;
446 pktin
.data
= srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
);
447 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
449 fatalbox("Out of memory");
452 memcpy(pktin
.body
-1, decompblk
, decomplen
);
454 pktin
.length
= decomplen
-1;
456 debug(("Packet payload post-decompression:\n"));
457 for (i
= -1; i
< pktin
.length
; i
++)
458 debug((" %02x", (unsigned char)pktin
.body
[i
]));
463 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
464 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
465 pktin
.type
== SSH1_MSG_DEBUG
||
466 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
467 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
468 long strlen
= GET_32BIT(pktin
.body
);
469 if (strlen
+ 4 != pktin
.length
) {
470 bombout(("Received data packet with bogus string length"));
475 pktin
.type
= pktin
.body
[-1];
477 if (pktin
.type
== SSH1_MSG_DEBUG
) {
478 /* log debug message */
480 int strlen
= GET_32BIT(pktin
.body
);
481 strcpy(buf
, "Remote: ");
482 if (strlen
> 70) strlen
= 70;
483 memcpy(buf
+8, pktin
.body
+4, strlen
);
484 buf
[8+strlen
] = '\0';
487 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
495 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
497 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
505 st
->cipherblk
= sccipher
->blksize
;
508 if (st
->cipherblk
< 8)
511 if (pktin
.maxlen
< st
->cipherblk
) {
512 pktin
.maxlen
= st
->cipherblk
;
513 pktin
.data
= (pktin
.data
== NULL ?
smalloc(st
->cipherblk
+APIEXTRA
) :
514 srealloc(pktin
.data
, st
->cipherblk
+APIEXTRA
));
516 fatalbox("Out of memory");
520 * Acquire and decrypt the first block of the packet. This will
521 * contain the length and padding details.
523 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
524 while ((*datalen
) == 0)
525 crReturn(st
->cipherblk
-st
->i
);
526 pktin
.data
[st
->i
] = *(*data
)++;
530 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
535 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
538 * Now get the length and padding figures.
540 st
->len
= GET_32BIT(pktin
.data
);
541 st
->pad
= pktin
.data
[4];
544 * This enables us to deduce the payload length.
546 st
->payload
= st
->len
- st
->pad
- 1;
548 pktin
.length
= st
->payload
+ 5;
551 * So now we can work out the total packet length.
553 st
->packetlen
= st
->len
+ 4;
554 st
->maclen
= scmac ? scmac
->len
: 0;
557 * Adjust memory allocation if packet is too big.
559 if (pktin
.maxlen
< st
->packetlen
+st
->maclen
) {
560 pktin
.maxlen
= st
->packetlen
+st
->maclen
;
561 pktin
.data
= (pktin
.data
== NULL ?
smalloc(pktin
.maxlen
+APIEXTRA
) :
562 srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
564 fatalbox("Out of memory");
568 * Read and decrypt the remainder of the packet.
570 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
; st
->i
++) {
571 while ((*datalen
) == 0)
572 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
573 pktin
.data
[st
->i
] = *(*data
)++;
576 /* Decrypt everything _except_ the MAC. */
578 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
579 st
->packetlen
- st
->cipherblk
);
582 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
583 for (st
->i
= 0; st
->i
< st
->packetlen
; st
->i
++)
584 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
591 if (scmac
&& !scmac
->verify(pktin
.data
, st
->len
+4, st
->incoming_sequence
)) {
592 bombout(("Incorrect MAC received on packet"));
595 st
->incoming_sequence
++; /* whether or not we MACed */
598 * Decompress packet payload.
601 unsigned char *newpayload
;
603 if (sccomp
&& sccomp
->decompress(pktin
.data
+5, pktin
.length
-5,
604 &newpayload
, &newlen
)) {
605 if (pktin
.maxlen
< newlen
+5) {
606 pktin
.maxlen
= newlen
+5;
607 pktin
.data
= (pktin
.data
== NULL ?
smalloc(pktin
.maxlen
+APIEXTRA
) :
608 srealloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
610 fatalbox("Out of memory");
612 pktin
.length
= 5 + newlen
;
613 memcpy(pktin
.data
+5, newpayload
, newlen
);
615 debug(("Post-decompression payload:\r\n"));
616 for (st
->i
= 0; st
->i
< newlen
; st
->i
++)
617 debug((" %02x", (unsigned char)pktin
.data
[5+st
->i
]));
626 pktin
.type
= pktin
.data
[5];
628 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
629 goto next_packet
; /* FIXME: print DEBUG message */
634 static void ssh1_pktout_size(int len
) {
637 len
+= 5; /* type and CRC */
641 pktout
.length
= len
-5;
642 if (pktout
.maxlen
< biglen
) {
643 pktout
.maxlen
= biglen
;
645 /* Allocate enough buffer space for extra block
646 * for MS CryptEncrypt() */
647 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+12) :
648 srealloc(pktout
.data
, biglen
+12));
650 pktout
.data
= (pktout
.data
== NULL ?
smalloc(biglen
+4) :
651 srealloc(pktout
.data
, biglen
+4));
654 fatalbox("Out of memory");
656 pktout
.body
= pktout
.data
+4+pad
+1;
659 static void s_wrpkt_start(int type
, int len
) {
660 ssh1_pktout_size(len
);
664 static int s_wrpkt_prepare(void) {
665 int pad
, len
, biglen
, i
;
668 pktout
.body
[-1] = pktout
.type
;
671 debug(("Packet payload pre-compression:\n"));
672 for (i
= -1; i
< pktout
.length
; i
++)
673 debug((" %02x", (unsigned char)pktout
.body
[i
]));
677 if (ssh1_compressing
) {
678 unsigned char *compblk
;
680 zlib_compress_block(pktout
.body
-1, pktout
.length
+1,
682 ssh1_pktout_size(complen
-1);
683 memcpy(pktout
.body
-1, compblk
, complen
);
686 debug(("Packet payload post-compression:\n"));
687 for (i
= -1; i
< pktout
.length
; i
++)
688 debug((" %02x", (unsigned char)pktout
.body
[i
]));
693 len
= pktout
.length
+ 5; /* type and CRC */
697 for (i
=0; i
<pad
; i
++)
698 pktout
.data
[i
+4] = random_byte();
699 crc
= crc32(pktout
.data
+4, biglen
-4);
700 PUT_32BIT(pktout
.data
+biglen
, crc
);
701 PUT_32BIT(pktout
.data
, len
);
704 debug(("Sending packet len=%d\r\n", biglen
+4));
705 for (i
= 0; i
< biglen
+4; i
++)
706 debug((" %02x", (unsigned char)pktout
.data
[i
]));
710 cipher
->encrypt(pktout
.data
+4, biglen
);
715 static void s_wrpkt(void) {
717 len
= s_wrpkt_prepare();
718 sk_write(s
, pktout
.data
, len
);
721 static void s_wrpkt_defer(void) {
723 len
= s_wrpkt_prepare();
724 if (deferred_len
+ len
> deferred_size
) {
725 deferred_size
= deferred_len
+ len
+ 128;
726 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
728 memcpy(deferred_send_data
+deferred_len
, pktout
.data
, len
);
733 * Construct a packet with the specified contents.
735 static void construct_packet(int pkttype
, va_list ap1
, va_list ap2
)
737 unsigned char *p
, *argp
, argchar
;
738 unsigned long argint
;
739 int pktlen
, argtype
, arglen
;
743 while ((argtype
= va_arg(ap1
, int)) != PKT_END
) {
746 (void) va_arg(ap1
, int);
750 (void) va_arg(ap1
, char);
754 (void) va_arg(ap1
, unsigned char *);
755 arglen
= va_arg(ap1
, int);
759 argp
= va_arg(ap1
, unsigned char *);
760 arglen
= strlen(argp
);
761 pktlen
+= 4 + arglen
;
764 bn
= va_arg(ap1
, Bignum
);
765 pktlen
+= ssh1_bignum_length(bn
);
772 s_wrpkt_start(pkttype
, pktlen
);
775 while ((argtype
= va_arg(ap2
, int)) != PKT_END
) {
778 argint
= va_arg(ap2
, int);
779 PUT_32BIT(p
, argint
);
783 argchar
= va_arg(ap2
, unsigned char);
788 argp
= va_arg(ap2
, unsigned char *);
789 arglen
= va_arg(ap2
, int);
790 memcpy(p
, argp
, arglen
);
794 argp
= va_arg(ap2
, unsigned char *);
795 arglen
= strlen(argp
);
796 PUT_32BIT(p
, arglen
);
797 memcpy(p
+ 4, argp
, arglen
);
801 bn
= va_arg(ap2
, Bignum
);
802 p
+= ssh1_write_bignum(p
, bn
);
808 static void send_packet(int pkttype
, ...) {
810 va_start(ap1
, pkttype
);
811 va_start(ap2
, pkttype
);
812 construct_packet(pkttype
, ap1
, ap2
);
816 static void defer_packet(int pkttype
, ...) {
818 va_start(ap1
, pkttype
);
819 va_start(ap2
, pkttype
);
820 construct_packet(pkttype
, ap1
, ap2
);
824 static int ssh_versioncmp(char *a
, char *b
) {
826 unsigned long av
, bv
;
828 av
= strtoul(a
, &ae
, 10);
829 bv
= strtoul(b
, &be
, 10);
830 if (av
!= bv
) return (av
< bv ?
-1 : +1);
831 if (*ae
== '.') ae
++;
832 if (*be
== '.') be
++;
833 av
= strtoul(ae
, &ae
, 10);
834 bv
= strtoul(be
, &be
, 10);
835 if (av
!= bv
) return (av
< bv ?
-1 : +1);
841 * Utility routines for putting an SSH-protocol `string' and
842 * `uint32' into a SHA state.
845 static void sha_string(SHA_State
*s
, void *str
, int len
) {
846 unsigned char lenblk
[4];
847 PUT_32BIT(lenblk
, len
);
848 SHA_Bytes(s
, lenblk
, 4);
849 SHA_Bytes(s
, str
, len
);
852 static void sha_uint32(SHA_State
*s
, unsigned i
) {
853 unsigned char intblk
[4];
854 PUT_32BIT(intblk
, i
);
855 SHA_Bytes(s
, intblk
, 4);
859 * SSH2 packet construction functions.
861 static void ssh2_pkt_ensure(int length
) {
862 if (pktout
.maxlen
< length
) {
863 pktout
.maxlen
= length
+ 256;
864 pktout
.data
= (pktout
.data
== NULL ?
smalloc(pktout
.maxlen
+APIEXTRA
) :
865 srealloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
867 fatalbox("Out of memory");
870 static void ssh2_pkt_adddata(void *data
, int len
) {
871 pktout
.length
+= len
;
872 ssh2_pkt_ensure(pktout
.length
);
873 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
875 static void ssh2_pkt_addbyte(unsigned char byte
) {
876 ssh2_pkt_adddata(&byte
, 1);
878 static void ssh2_pkt_init(int pkt_type
) {
880 ssh2_pkt_addbyte((unsigned char)pkt_type
);
882 static void ssh2_pkt_addbool(unsigned char value
) {
883 ssh2_pkt_adddata(&value
, 1);
885 static void ssh2_pkt_adduint32(unsigned long value
) {
888 ssh2_pkt_adddata(x
, 4);
890 static void ssh2_pkt_addstring_start(void) {
891 ssh2_pkt_adduint32(0);
892 pktout
.savedpos
= pktout
.length
;
894 static void ssh2_pkt_addstring_str(char *data
) {
895 ssh2_pkt_adddata(data
, strlen(data
));
896 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
897 pktout
.length
- pktout
.savedpos
);
899 static void ssh2_pkt_addstring_data(char *data
, int len
) {
900 ssh2_pkt_adddata(data
, len
);
901 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
902 pktout
.length
- pktout
.savedpos
);
904 static void ssh2_pkt_addstring(char *data
) {
905 ssh2_pkt_addstring_start();
906 ssh2_pkt_addstring_str(data
);
908 static char *ssh2_mpint_fmt(Bignum b
, int *len
) {
910 int i
, n
= (ssh1_bignum_bitcount(b
)+7)/8;
913 fatalbox("out of memory");
915 for (i
= 1; i
<= n
; i
++)
916 p
[i
] = bignum_byte(b
, n
-i
);
918 while (i
<= n
&& p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
920 memmove(p
, p
+i
, n
+1-i
);
924 static void ssh2_pkt_addmp(Bignum b
) {
927 p
= ssh2_mpint_fmt(b
, &len
);
928 ssh2_pkt_addstring_start();
929 ssh2_pkt_addstring_data(p
, len
);
934 * Construct an SSH2 final-form packet: compress it, encrypt it,
935 * put the MAC on it. Final packet, ready to be sent, is stored in
936 * pktout.data. Total length is returned.
938 static int ssh2_pkt_construct(void) {
939 int cipherblk
, maclen
, padding
, i
;
940 static unsigned long outgoing_sequence
= 0;
943 * Compress packet payload.
946 debug(("Pre-compression payload:\r\n"));
947 for (i
= 5; i
< pktout
.length
; i
++)
948 debug((" %02x", (unsigned char)pktout
.data
[i
]));
952 unsigned char *newpayload
;
954 if (cscomp
&& cscomp
->compress(pktout
.data
+5, pktout
.length
-5,
955 &newpayload
, &newlen
)) {
957 ssh2_pkt_adddata(newpayload
, newlen
);
963 * Add padding. At least four bytes, and must also bring total
964 * length (minus MAC) up to a multiple of the block size.
966 cipherblk
= cscipher ? cscipher
->blksize
: 8; /* block size */
967 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
969 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
970 maclen
= csmac ? csmac
->len
: 0;
971 ssh2_pkt_ensure(pktout
.length
+ padding
+ maclen
);
972 pktout
.data
[4] = padding
;
973 for (i
= 0; i
< padding
; i
++)
974 pktout
.data
[pktout
.length
+ i
] = random_byte();
975 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
977 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
979 outgoing_sequence
++; /* whether or not we MACed */
982 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
983 for (i
= 0; i
< pktout
.length
+padding
; i
++)
984 debug((" %02x", (unsigned char)pktout
.data
[i
]));
989 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
991 /* Ready-to-send packet starts at pktout.data. We return length. */
992 return pktout
.length
+ padding
+ maclen
;
996 * Construct and send an SSH2 packet immediately.
998 static void ssh2_pkt_send(void) {
999 int len
= ssh2_pkt_construct();
1000 sk_write(s
, pktout
.data
, len
);
1004 * Construct an SSH2 packet and add it to a deferred data block.
1005 * Useful for sending multiple packets in a single sk_write() call,
1006 * to prevent a traffic-analysing listener from being able to work
1007 * out the length of any particular packet (such as the password
1010 * Note that because SSH2 sequence-numbers its packets, this can
1011 * NOT be used as an m4-style `defer' allowing packets to be
1012 * constructed in one order and sent in another.
1014 static void ssh2_pkt_defer(void) {
1015 int len
= ssh2_pkt_construct();
1016 if (deferred_len
+ len
> deferred_size
) {
1017 deferred_size
= deferred_len
+ len
+ 128;
1018 deferred_send_data
= srealloc(deferred_send_data
, deferred_size
);
1020 memcpy(deferred_send_data
+deferred_len
, pktout
.data
, len
);
1021 deferred_len
+= len
;
1025 * Send the whole deferred data block constructed by
1026 * ssh2_pkt_defer() or SSH1's defer_packet().
1028 static void ssh_pkt_defersend(void) {
1029 sk_write(s
, deferred_send_data
, deferred_len
);
1030 deferred_len
= deferred_size
= 0;
1031 sfree(deferred_send_data
);
1032 deferred_send_data
= NULL
;
1036 void bndebug(char *string
, Bignum b
) {
1039 p
= ssh2_mpint_fmt(b
, &len
);
1040 debug(("%s", string
));
1041 for (i
= 0; i
< len
; i
++)
1042 debug((" %02x", p
[i
]));
1048 static void sha_mpint(SHA_State
*s
, Bignum b
) {
1051 p
= ssh2_mpint_fmt(b
, &len
);
1052 sha_string(s
, p
, len
);
1057 * SSH2 packet decode functions.
1059 static unsigned long ssh2_pkt_getuint32(void) {
1060 unsigned long value
;
1061 if (pktin
.length
- pktin
.savedpos
< 4)
1062 return 0; /* arrgh, no way to decline (FIXME?) */
1063 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
1064 pktin
.savedpos
+= 4;
1067 static int ssh2_pkt_getbool(void) {
1068 unsigned long value
;
1069 if (pktin
.length
- pktin
.savedpos
< 1)
1070 return 0; /* arrgh, no way to decline (FIXME?) */
1071 value
= pktin
.data
[pktin
.savedpos
] != 0;
1075 static void ssh2_pkt_getstring(char **p
, int *length
) {
1077 if (pktin
.length
- pktin
.savedpos
< 4)
1079 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
1080 pktin
.savedpos
+= 4;
1081 if (pktin
.length
- pktin
.savedpos
< *length
)
1083 *p
= pktin
.data
+pktin
.savedpos
;
1084 pktin
.savedpos
+= *length
;
1086 static Bignum
ssh2_pkt_getmp(void) {
1091 ssh2_pkt_getstring(&p
, &length
);
1095 bombout(("internal error: Can't handle negative mpints"));
1098 b
= bignum_from_bytes(p
, length
);
1103 * Examine the remote side's version string and compare it against
1104 * a list of known buggy implementations.
1106 static void ssh_detect_bugs(char *vstring
) {
1107 char *imp
; /* pointer to implementation part */
1109 imp
+= strcspn(imp
, "-");
1110 imp
+= strcspn(imp
, "-");
1112 ssh_remote_bugs
= 0;
1114 if (!strcmp(imp
, "1.2.18") || !strcmp(imp
, "1.2.19") ||
1115 !strcmp(imp
, "1.2.20") || !strcmp(imp
, "1.2.21") ||
1116 !strcmp(imp
, "1.2.22")) {
1118 * These versions don't support SSH1_MSG_IGNORE, so we have
1119 * to use a different defence against password length
1122 ssh_remote_bugs
|= BUG_CHOKES_ON_SSH1_IGNORE
;
1123 logevent("We believe remote version has SSH1 ignore bug");
1126 if (!strncmp(imp
, "2.1.0", 5) || !strncmp(imp
, "2.0.", 4) ||
1127 !strncmp(imp
, "2.2.0", 5) || !strncmp(imp
, "2.3.0", 5) ||
1128 !strncmp(imp
, "2.1 ", 4)) {
1130 * These versions have the HMAC bug.
1132 ssh_remote_bugs
|= BUG_SSH2_HMAC
;
1133 logevent("We believe remote version has SSH2 HMAC bug");
1137 static int do_ssh_init(unsigned char c
) {
1139 static char version
[10];
1140 static char vstring
[80];
1141 static char vlog
[sizeof(vstring
)+20];
1146 /* Search for the string "SSH-" in the input. */
1149 static const int transS
[] = { 1, 2, 2, 1 };
1150 static const int transH
[] = { 0, 0, 3, 0 };
1151 static const int transminus
[] = { 0, 0, 0, -1 };
1152 if (c
== 'S') i
= transS
[i
];
1153 else if (c
== 'H') i
= transH
[i
];
1154 else if (c
== '-') i
= transminus
[i
];
1158 crReturn(1); /* get another character */
1161 strcpy(vstring
, "SSH-");
1165 crReturn(1); /* get another char */
1166 if (vsp
< vstring
+sizeof(vstring
)-1)
1172 } else if (i
< sizeof(version
)-1)
1179 ssh_agentfwd_enabled
= FALSE
;
1180 rdpkt2_state
.incoming_sequence
= 0;
1183 sprintf(vlog
, "Server version: %s", vstring
);
1184 ssh_detect_bugs(vstring
);
1185 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1189 * Server version "1.99" means we can choose whether we use v1
1190 * or v2 protocol. Choice is based on cfg.sshprot.
1192 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1194 * This is a v2 server. Begin v2 protocol.
1197 sprintf(verstring
, "SSH-2.0-%s", sshver
);
1198 SHA_Init(&exhashbase
);
1200 * Hash our version string and their version string.
1202 sha_string(&exhashbase
, verstring
, strlen(verstring
));
1203 sha_string(&exhashbase
, vstring
, strcspn(vstring
, "\r\n"));
1204 sprintf(vstring
, "%s\n", verstring
);
1205 sprintf(vlog
, "We claim version: %s", verstring
);
1207 logevent("Using SSH protocol version 2");
1208 sk_write(s
, vstring
, strlen(vstring
));
1209 ssh_protocol
= ssh2_protocol
;
1211 s_rdpkt
= ssh2_rdpkt
;
1214 * This is a v1 server. Begin v1 protocol.
1216 sprintf(vstring
, "SSH-%s-%s\n",
1217 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"),
1219 sprintf(vlog
, "We claim version: %s", vstring
);
1220 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1222 logevent("Using SSH protocol version 1");
1223 sk_write(s
, vstring
, strlen(vstring
));
1224 ssh_protocol
= ssh1_protocol
;
1226 s_rdpkt
= ssh1_rdpkt
;
1228 ssh_state
= SSH_STATE_BEFORE_SIZE
;
1233 static void ssh_gotdata(unsigned char *data
, int datalen
)
1238 * To begin with, feed the characters one by one to the
1239 * protocol initialisation / selection function do_ssh_init().
1240 * When that returns 0, we're done with the initial greeting
1241 * exchange and can move on to packet discipline.
1246 crReturnV
; /* more data please */
1247 ret
= do_ssh_init(*data
);
1254 * We emerge from that loop when the initial negotiation is
1255 * over and we have selected an s_rdpkt function. Now pass
1256 * everything to s_rdpkt, and then pass the resulting packets
1257 * to the proper protocol handler.
1262 while (datalen
> 0) {
1263 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
1264 ssh_protocol(NULL
, 0, 1);
1265 if (ssh_state
== SSH_STATE_CLOSED
) {
1275 static int ssh_closing (Plug plug
, char *error_msg
, int error_code
, int calling_back
) {
1276 ssh_state
= SSH_STATE_CLOSED
;
1280 /* A socket error has occurred. */
1281 connection_fatal (error_msg
);
1283 /* Otherwise, the remote side closed the connection normally. */
1288 static int ssh_receive(Plug plug
, int urgent
, char *data
, int len
) {
1289 ssh_gotdata (data
, len
);
1290 if (ssh_state
== SSH_STATE_CLOSED
) {
1301 * Connect to specified host and port.
1302 * Returns an error message, or NULL on success.
1303 * Also places the canonical host name into `realhost'.
1305 static char *connect_to_host(char *host
, int port
, char **realhost
)
1307 static struct plug_function_table fn_table
= {
1310 }, *fn_table_ptr
= &fn_table
;
1319 savedhost
= smalloc(1+strlen(host
));
1321 fatalbox("Out of memory");
1322 strcpy(savedhost
, host
);
1325 port
= 22; /* default ssh port */
1338 addr
= sk_namelookup(host
, realhost
);
1339 if ( (err
= sk_addr_error(addr
)) )
1349 s
= sk_new(addr
, port
, 0, 1, &fn_table_ptr
);
1350 if ( (err
= sk_socket_error(s
)) )
1354 sk_write(s
, "connect ", 8);
1355 sk_write(s
, FWhost
, strlen(FWhost
));
1358 sprintf(buf
, " %d\n", FWport
);
1359 sk_write(s
, buf
, strlen(buf
));
1367 * Handle the key exchange and user authentication phases.
1369 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1372 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1373 unsigned char cookie
[8];
1374 struct RSAKey servkey
, hostkey
;
1375 struct MD5Context md5c
;
1376 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1377 static int tried_publickey
;
1378 static unsigned char session_id
[16];
1380 static char username
[100];
1384 if (!ispkt
) crWaitUntil(ispkt
);
1386 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1387 bombout(("Public key packet not received"));
1391 logevent("Received public keys");
1393 memcpy(cookie
, pktin
.body
, 8);
1395 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1396 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1399 * Log the host key fingerprint.
1403 logevent("Host key fingerprint is:");
1404 strcpy(logmsg
, " ");
1405 hostkey
.comment
= NULL
;
1406 rsa_fingerprint(logmsg
+strlen(logmsg
), sizeof(logmsg
)-strlen(logmsg
),
1411 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1412 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1415 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1416 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1417 MD5Update(&md5c
, pktin
.body
, 8);
1418 MD5Final(session_id
, &md5c
);
1420 for (i
=0; i
<32; i
++)
1421 session_key
[i
] = random_byte();
1423 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1425 rsabuf
= smalloc(len
);
1427 fatalbox("Out of memory");
1430 * Verify the host key.
1434 * First format the key into a string.
1436 int len
= rsastr_len(&hostkey
);
1437 char fingerprint
[100];
1438 char *keystr
= smalloc(len
);
1440 fatalbox("Out of memory");
1441 rsastr_fmt(keystr
, &hostkey
);
1442 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1443 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
, fingerprint
);
1447 for (i
=0; i
<32; i
++) {
1448 rsabuf
[i
] = session_key
[i
];
1450 rsabuf
[i
] ^= session_id
[i
];
1453 if (hostkey
.bytes
> servkey
.bytes
) {
1454 rsaencrypt(rsabuf
, 32, &servkey
);
1455 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1457 rsaencrypt(rsabuf
, 32, &hostkey
);
1458 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1461 logevent("Encrypted session key");
1463 switch (cfg
.cipher
) {
1464 case CIPHER_BLOWFISH
: cipher_type
= SSH_CIPHER_BLOWFISH
; break;
1465 case CIPHER_DES
: cipher_type
= SSH_CIPHER_DES
; break;
1466 case CIPHER_3DES
: cipher_type
= SSH_CIPHER_3DES
; break;
1468 c_write_str("AES not supported in SSH1, falling back to 3DES\r\n");
1469 cipher_type
= SSH_CIPHER_3DES
;
1472 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1473 c_write_str("Selected cipher not supported, falling back to 3DES\r\n");
1474 cipher_type
= SSH_CIPHER_3DES
;
1476 switch (cipher_type
) {
1477 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1478 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1479 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1482 send_packet(SSH1_CMSG_SESSION_KEY
,
1483 PKT_CHAR
, cipher_type
,
1484 PKT_DATA
, cookie
, 8,
1485 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1486 PKT_DATA
, rsabuf
, len
,
1490 logevent("Trying to enable encryption...");
1494 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1495 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1497 cipher
->sesskey(session_key
);
1501 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1502 bombout(("Encryption not successfully enabled"));
1506 logevent("Successfully started encryption");
1512 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1514 if (!ssh_get_line("login as: ",
1515 username
, sizeof(username
), FALSE
)) {
1517 * get_line failed to get a username.
1520 logevent("No username provided. Abandoning session.");
1521 ssh_state
= SSH_STATE_CLOSED
;
1525 c_write_str("login as: ");
1528 crWaitUntil(!ispkt
);
1529 while (inlen
--) switch (c
= *in
++) {
1536 c_write_str("\b \b");
1542 c_write_str("\b \b");
1551 if (((c
>= ' ' && c
<= '~') ||
1552 ((unsigned char)c
>= 160)) && pos
< 40) {
1553 username
[pos
++] = c
;
1559 c_write_str("\r\n");
1560 username
[strcspn(username
, "\n\r")] = '\0';
1563 strncpy(username
, cfg
.username
, 99);
1564 username
[99] = '\0';
1567 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1569 char userlog
[22+sizeof(username
)];
1570 sprintf(userlog
, "Sent username \"%s\"", username
);
1572 if (flags
& FLAG_INTERACTIVE
&&
1573 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
1574 strcat(userlog
, "\r\n");
1575 c_write_str(userlog
);
1582 tried_publickey
= 0;
1584 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1585 static char password
[100];
1586 static char prompt
[200];
1589 static int pwpkt_type
;
1591 * Show password prompt, having first obtained it via a TIS
1592 * or CryptoCard exchange if we're doing TIS or CryptoCard
1595 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1596 if (agent_exists()) {
1598 * Attempt RSA authentication using Pageant.
1600 static unsigned char request
[5], *response
, *p
;
1601 static int responselen
;
1602 static int i
, nkeys
;
1603 static int authed
= FALSE
;
1606 logevent("Pageant is running. Requesting keys.");
1608 /* Request the keys held by the agent. */
1609 PUT_32BIT(request
, 1);
1610 request
[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES
;
1611 agent_query(request
, 5, &r
, &responselen
);
1612 response
= (unsigned char *)r
;
1613 if (response
&& responselen
>= 5 &&
1614 response
[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER
) {
1616 nkeys
= GET_32BIT(p
); p
+= 4;
1617 { char buf
[64]; sprintf(buf
, "Pageant has %d SSH1 keys", nkeys
);
1619 for (i
= 0; i
< nkeys
; i
++) {
1620 static struct RSAKey key
;
1621 static Bignum challenge
;
1622 static char *commentp
;
1623 static int commentlen
;
1625 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
1628 p
+= ssh1_read_bignum(p
, &key
.exponent
);
1629 p
+= ssh1_read_bignum(p
, &key
.modulus
);
1630 commentlen
= GET_32BIT(p
); p
+= 4;
1631 commentp
= p
; p
+= commentlen
;
1632 send_packet(SSH1_CMSG_AUTH_RSA
,
1633 PKT_BIGNUM
, key
.modulus
, PKT_END
);
1635 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1636 logevent("Key refused");
1639 logevent("Received RSA challenge");
1640 ssh1_read_bignum(pktin
.body
, &challenge
);
1642 char *agentreq
, *q
, *ret
;
1644 len
= 1 + 4; /* message type, bit count */
1645 len
+= ssh1_bignum_length(key
.exponent
);
1646 len
+= ssh1_bignum_length(key
.modulus
);
1647 len
+= ssh1_bignum_length(challenge
);
1648 len
+= 16; /* session id */
1649 len
+= 4; /* response format */
1650 agentreq
= smalloc(4 + len
);
1651 PUT_32BIT(agentreq
, len
);
1653 *q
++ = SSH1_AGENTC_RSA_CHALLENGE
;
1654 PUT_32BIT(q
, ssh1_bignum_bitcount(key
.modulus
));
1656 q
+= ssh1_write_bignum(q
, key
.exponent
);
1657 q
+= ssh1_write_bignum(q
, key
.modulus
);
1658 q
+= ssh1_write_bignum(q
, challenge
);
1659 memcpy(q
, session_id
, 16); q
+= 16;
1660 PUT_32BIT(q
, 1); /* response format */
1661 agent_query(agentreq
, len
+4, &ret
, &retlen
);
1664 if (ret
[4] == SSH1_AGENT_RSA_RESPONSE
) {
1665 logevent("Sending Pageant's response");
1666 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1667 PKT_DATA
, ret
+5, 16, PKT_END
);
1670 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1671 logevent("Pageant's response accepted");
1672 if (flags
& FLAG_VERBOSE
) {
1673 c_write_str("Authenticated using RSA key \"");
1674 c_write(commentp
, commentlen
);
1675 c_write_str("\" from agent\r\n");
1679 logevent("Pageant's response not accepted");
1681 logevent("Pageant failed to answer challenge");
1685 logevent("No reply received from Pageant");
1688 freebn(key
.exponent
);
1689 freebn(key
.modulus
);
1698 if (*cfg
.keyfile
&& !tried_publickey
)
1699 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1701 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1703 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1704 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1705 logevent("Requested TIS authentication");
1706 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1708 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1709 logevent("TIS authentication declined");
1710 if (flags
& FLAG_INTERACTIVE
)
1711 c_write_str("TIS authentication refused.\r\n");
1713 int challengelen
= ((pktin
.body
[0] << 24) |
1714 (pktin
.body
[1] << 16) |
1715 (pktin
.body
[2] << 8) |
1717 logevent("Received TIS challenge");
1718 if (challengelen
> sizeof(prompt
)-1)
1719 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1720 memcpy(prompt
, pktin
.body
+4, challengelen
);
1721 prompt
[challengelen
] = '\0';
1724 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1726 (supported_auths_mask
& (1<<SSH1_AUTH_CCARD
))) {
1727 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
1728 logevent("Requested CryptoCard authentication");
1729 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
1731 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
1732 logevent("CryptoCard authentication declined");
1733 c_write_str("CryptoCard authentication refused.\r\n");
1735 int challengelen
= ((pktin
.body
[0] << 24) |
1736 (pktin
.body
[1] << 16) |
1737 (pktin
.body
[2] << 8) |
1739 logevent("Received CryptoCard challenge");
1740 if (challengelen
> sizeof(prompt
)-1)
1741 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1742 memcpy(prompt
, pktin
.body
+4, challengelen
);
1743 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
1744 sizeof(prompt
)-challengelen
);
1745 prompt
[sizeof(prompt
)-1] = '\0';
1748 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1749 sprintf(prompt
, "%.90s@%.90s's password: ",
1750 username
, savedhost
);
1752 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1753 char *comment
= NULL
;
1754 if (flags
& FLAG_VERBOSE
)
1755 c_write_str("Trying public key authentication.\r\n");
1756 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
1757 if (flags
& FLAG_VERBOSE
)
1758 c_write_str("No passphrase required.\r\n");
1761 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
1766 if (!ssh_get_line(prompt
, password
, sizeof(password
), TRUE
)) {
1768 * get_line failed to get a password (for example
1769 * because one was supplied on the command line
1770 * which has already failed to work). Terminate.
1772 logevent("No more passwords to try");
1773 ssh_state
= SSH_STATE_CLOSED
;
1777 c_write_str(prompt
);
1781 crWaitUntil(!ispkt
);
1782 while (inlen
--) switch (c
= *in
++) {
1799 if (((c
>= ' ' && c
<= '~') ||
1800 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1801 password
[pos
++] = c
;
1805 c_write_str("\r\n");
1809 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1811 * Try public key authentication with the specified
1814 static struct RSAKey pubkey
;
1815 static Bignum challenge
, response
;
1817 static unsigned char buffer
[32];
1819 tried_publickey
= 1;
1820 i
= loadrsakey(cfg
.keyfile
, &pubkey
, password
);
1822 c_write_str("Couldn't load public key from ");
1823 c_write_str(cfg
.keyfile
);
1824 c_write_str(".\r\n");
1825 continue; /* go and try password */
1828 c_write_str("Wrong passphrase.\r\n");
1829 tried_publickey
= 0;
1830 continue; /* try again */
1834 * Send a public key attempt.
1836 send_packet(SSH1_CMSG_AUTH_RSA
,
1837 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1840 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1841 c_write_str("Server refused our public key.\r\n");
1842 continue; /* go and try password */
1844 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1845 bombout(("Bizarre response to offer of public key"));
1848 ssh1_read_bignum(pktin
.body
, &challenge
);
1849 response
= rsadecrypt(challenge
, &pubkey
);
1850 freebn(pubkey
.private_exponent
); /* burn the evidence */
1852 for (i
= 0; i
< 32; i
++) {
1853 buffer
[i
] = bignum_byte(response
, 31-i
);
1857 MD5Update(&md5c
, buffer
, 32);
1858 MD5Update(&md5c
, session_id
, 16);
1859 MD5Final(buffer
, &md5c
);
1861 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1862 PKT_DATA
, buffer
, 16, PKT_END
);
1865 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1866 if (flags
& FLAG_VERBOSE
)
1867 c_write_str("Failed to authenticate with our public key.\r\n");
1868 continue; /* go and try password */
1869 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1870 bombout(("Bizarre response to RSA authentication response"));
1874 break; /* we're through! */
1876 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1878 * Defence against traffic analysis: we send a
1879 * whole bunch of packets containing strings of
1880 * different lengths. One of these strings is the
1881 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
1882 * The others are all random data in
1883 * SSH1_MSG_IGNORE packets. This way a passive
1884 * listener can't tell which is the password, and
1885 * hence can't deduce the password length.
1887 * Anybody with a password length greater than 16
1888 * bytes is going to have enough entropy in their
1889 * password that a listener won't find it _that_
1890 * much help to know how long it is. So what we'll
1893 * - if password length < 16, we send 15 packets
1894 * containing string lengths 1 through 15
1896 * - otherwise, we let N be the nearest multiple
1897 * of 8 below the password length, and send 8
1898 * packets containing string lengths N through
1899 * N+7. This won't obscure the order of
1900 * magnitude of the password length, but it will
1901 * introduce a bit of extra uncertainty.
1903 * A few servers (the old 1.2.18 through 1.2.22)
1904 * can't deal with SSH1_MSG_IGNORE. For these
1905 * servers, we need an alternative defence. We make
1906 * use of the fact that the password is interpreted
1907 * as a C string: so we can append a NUL, then some
1910 if (ssh_remote_bugs
& BUG_CHOKES_ON_SSH1_IGNORE
) {
1915 len
= strlen(password
);
1916 if (len
< sizeof(string
)) {
1918 strcpy(string
, password
);
1919 len
++; /* cover the zero byte */
1920 while (len
< sizeof(string
)) {
1921 string
[len
++] = (char)random_byte();
1926 send_packet(pwpkt_type
, PKT_INT
, len
,
1927 PKT_DATA
, s
, len
, PKT_END
);
1929 int bottom
, top
, pwlen
, i
;
1932 pwlen
= strlen(password
);
1934 bottom
= 0; /* zero length passwords are OK! :-) */
1937 bottom
= pwlen
&~ 7;
1941 assert(pwlen
>= bottom
&& pwlen
<= top
);
1943 randomstr
= smalloc(top
+1);
1945 for (i
= bottom
; i
<= top
; i
++) {
1947 defer_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1949 for (j
= 0; j
< i
; j
++) {
1951 randomstr
[j
] = random_byte();
1952 } while (randomstr
[j
] == '\0');
1954 randomstr
[i
] = '\0';
1955 defer_packet(SSH1_MSG_IGNORE
,
1956 PKT_STR
, randomstr
, PKT_END
);
1959 ssh_pkt_defersend();
1962 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1965 logevent("Sent password");
1966 memset(password
, 0, strlen(password
));
1968 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1969 if (flags
& FLAG_VERBOSE
)
1970 c_write_str("Access denied\r\n");
1971 logevent("Authentication refused");
1972 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1973 logevent("Received disconnect request");
1974 ssh_state
= SSH_STATE_CLOSED
;
1976 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1977 bombout(("Strange packet received, type %d", pktin
.type
));
1982 logevent("Authentication successful");
1987 void sshfwd_close(struct ssh_channel
*c
) {
1988 if (c
&& !c
->closes
) {
1989 if (ssh_version
== 1) {
1990 send_packet(SSH1_MSG_CHANNEL_CLOSE
, PKT_INT
, c
->remoteid
, PKT_END
);
1992 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
1993 ssh2_pkt_adduint32(c
->remoteid
);
1997 if (c
->type
== CHAN_X11
) {
1999 logevent("X11 connection terminated");
2004 void sshfwd_write(struct ssh_channel
*c
, char *buf
, int len
) {
2005 if (ssh_version
== 1) {
2006 send_packet(SSH1_MSG_CHANNEL_DATA
,
2007 PKT_INT
, c
->remoteid
,
2012 ssh2_add_channel_data(c
, buf
, len
);
2017 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
2022 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
2025 if (ssh_state
== SSH_STATE_CLOSED
)
2028 if (cfg
.agentfwd
&& agent_exists()) {
2029 logevent("Requesting agent forwarding");
2030 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
2031 do { crReturnV
; } while (!ispkt
);
2032 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
2033 bombout(("Protocol confusion"));
2035 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2036 logevent("Agent forwarding refused");
2038 logevent("Agent forwarding enabled");
2039 ssh_agentfwd_enabled
= TRUE
;
2043 if (cfg
.x11_forward
) {
2044 char proto
[20], data
[64];
2045 logevent("Requesting X11 forwarding");
2046 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
2047 send_packet(SSH1_CMSG_X11_REQUEST_FORWARDING
,
2048 PKT_STR
, proto
, PKT_STR
, data
,
2051 do { crReturnV
; } while (!ispkt
);
2052 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
2053 bombout(("Protocol confusion"));
2055 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2056 logevent("X11 forwarding refused");
2058 logevent("X11 forwarding enabled");
2059 ssh_X11_fwd_enabled
= TRUE
;
2064 send_packet(SSH1_CMSG_REQUEST_PTY
,
2065 PKT_STR
, cfg
.termtype
,
2066 PKT_INT
, rows
, PKT_INT
, cols
,
2067 PKT_INT
, 0, PKT_INT
, 0,
2070 ssh_state
= SSH_STATE_INTERMED
;
2071 do { crReturnV
; } while (!ispkt
);
2072 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
2073 bombout(("Protocol confusion"));
2075 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2076 c_write_str("Server refused to allocate pty\r\n");
2077 ssh_editing
= ssh_echoing
= 1;
2079 logevent("Allocated pty");
2081 ssh_editing
= ssh_echoing
= 1;
2084 if (cfg
.compression
) {
2085 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
2086 do { crReturnV
; } while (!ispkt
);
2087 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
2088 bombout(("Protocol confusion"));
2090 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2091 c_write_str("Server refused to compress\r\n");
2093 logevent("Started compression");
2094 ssh1_compressing
= TRUE
;
2095 zlib_compress_init();
2096 zlib_decompress_init();
2099 if (*cfg
.remote_cmd
)
2100 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
2102 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
2103 logevent("Started session");
2105 ssh_state
= SSH_STATE_SESSION
;
2109 ssh_special(TS_EOF
);
2111 ldisc_send(NULL
, 0); /* cause ldisc to notice changes */
2113 ssh_channels
= newtree234(ssh_channelcmp
);
2117 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
2118 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
2119 long len
= GET_32BIT(pktin
.body
);
2120 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
2122 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
2123 ssh_state
= SSH_STATE_CLOSED
;
2124 logevent("Received disconnect request");
2126 } else if (pktin
.type
== SSH1_SMSG_X11_OPEN
) {
2127 /* Remote side is trying to open a channel to talk to our
2128 * X-Server. Give them back a local channel number. */
2130 struct ssh_channel
*c
, *d
;
2133 logevent("Received X11 connect request");
2134 /* Refuse if X11 forwarding is disabled. */
2135 if (!ssh_X11_fwd_enabled
) {
2136 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2137 PKT_INT
, GET_32BIT(pktin
.body
),
2139 logevent("Rejected X11 connect request");
2141 c
= smalloc(sizeof(struct ssh_channel
));
2143 if ( x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
2144 logevent("opening X11 forward connection failed");
2146 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2147 PKT_INT
, GET_32BIT(pktin
.body
),
2150 logevent("opening X11 forward connection succeeded");
2151 for (i
=1, d
= first234(ssh_channels
, &e
); d
; d
= next234(&e
)) {
2153 break; /* found a free number */
2156 c
->remoteid
= GET_32BIT(pktin
.body
);
2159 c
->type
= CHAN_X11
; /* identify channel type */
2160 add234(ssh_channels
, c
);
2161 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2162 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2164 logevent("Opened X11 forward channel");
2167 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
2168 /* Remote side is trying to open a channel to talk to our
2169 * agent. Give them back a local channel number. */
2171 struct ssh_channel
*c
;
2174 /* Refuse if agent forwarding is disabled. */
2175 if (!ssh_agentfwd_enabled
) {
2176 send_packet(SSH1_MSG_CHANNEL_OPEN_FAILURE
,
2177 PKT_INT
, GET_32BIT(pktin
.body
),
2181 for (c
= first234(ssh_channels
, &e
); c
; c
= next234(&e
)) {
2183 break; /* found a free number */
2186 c
= smalloc(sizeof(struct ssh_channel
));
2187 c
->remoteid
= GET_32BIT(pktin
.body
);
2190 c
->type
= CHAN_AGENT
; /* identify channel type */
2191 c
->u
.a
.lensofar
= 0;
2192 add234(ssh_channels
, c
);
2193 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
2194 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
2197 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
2198 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
2199 /* Remote side closes a channel. */
2200 unsigned i
= GET_32BIT(pktin
.body
);
2201 struct ssh_channel
*c
;
2202 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2205 closetype
= (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
2206 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
, PKT_END
);
2207 if ((c
->closes
== 0) && (c
->type
== CHAN_X11
)) {
2208 logevent("X11 connection closed");
2209 assert(c
->u
.x11
.s
!= NULL
);
2210 x11_close(c
->u
.x11
.s
);
2213 c
->closes
|= closetype
;
2214 if (c
->closes
== 3) {
2215 del234(ssh_channels
, c
);
2219 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
2220 /* Data sent down one of our channels. */
2221 int i
= GET_32BIT(pktin
.body
);
2222 int len
= GET_32BIT(pktin
.body
+4);
2223 unsigned char *p
= pktin
.body
+8;
2224 struct ssh_channel
*c
;
2225 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
2229 x11_send(c
->u
.x11
.s
, p
, len
);
2232 /* Data for an agent message. Buffer it. */
2234 if (c
->u
.a
.lensofar
< 4) {
2235 int l
= min(4 - c
->u
.a
.lensofar
, len
);
2236 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
, l
);
2237 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
2239 if (c
->u
.a
.lensofar
== 4) {
2240 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
2241 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
2242 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
2244 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
2245 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
, len
);
2246 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
, l
);
2247 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
2249 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
2250 void *reply
, *sentreply
;
2252 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
2257 /* Fake SSH_AGENT_FAILURE. */
2258 sentreply
= "\0\0\0\1\5";
2261 send_packet(SSH1_MSG_CHANNEL_DATA
,
2262 PKT_INT
, c
->remoteid
,
2264 PKT_DATA
, sentreply
, replylen
,
2268 sfree(c
->u
.a
.message
);
2269 c
->u
.a
.lensofar
= 0;
2275 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
2276 /* may be from EXEC_SHELL on some servers */
2277 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
2278 /* may be from EXEC_SHELL on some servers
2279 * if no pty is available or in other odd cases. Ignore */
2280 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
2281 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
2283 bombout(("Strange packet received: type %d", pktin
.type
));
2288 int len
= min(inlen
, 512);
2289 send_packet(SSH1_CMSG_STDIN_DATA
,
2290 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
2301 * Utility routine for decoding comma-separated strings in KEXINIT.
2303 static int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
2304 int needlen
= strlen(needle
);
2307 * Is it at the start of the string?
2309 if (haylen
>= needlen
&& /* haystack is long enough */
2310 !memcmp(needle
, haystack
, needlen
) && /* initial match */
2311 (haylen
== needlen
|| haystack
[needlen
] == ',')
2312 /* either , or EOS follows */
2316 * If not, search for the next comma and resume after that.
2317 * If no comma found, terminate.
2319 while (haylen
> 0 && *haystack
!= ',')
2320 haylen
--, haystack
++;
2323 haylen
--, haystack
++; /* skip over comma itself */
2328 * SSH2 key creation method.
2330 static void ssh2_mkkey(Bignum K
, char *H
, char *sessid
, char chr
, char *keyspace
) {
2332 /* First 20 bytes. */
2335 SHA_Bytes(&s
, H
, 20);
2336 SHA_Bytes(&s
, &chr
, 1);
2337 SHA_Bytes(&s
, sessid
, 20);
2338 SHA_Final(&s
, keyspace
);
2339 /* Next 20 bytes. */
2342 SHA_Bytes(&s
, H
, 20);
2343 SHA_Bytes(&s
, keyspace
, 20);
2344 SHA_Final(&s
, keyspace
+20);
2348 * Handle the SSH2 transport layer.
2350 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
2352 static int i
, j
, len
, nbits
, pbits
;
2354 static Bignum p
, g
, e
, f
, K
;
2355 static int kex_init_value
, kex_reply_value
;
2356 static const struct ssh_mac
**maclist
;
2358 static const struct ssh2_cipher
*cscipher_tobe
= NULL
;
2359 static const struct ssh2_cipher
*sccipher_tobe
= NULL
;
2360 static const struct ssh_mac
*csmac_tobe
= NULL
;
2361 static const struct ssh_mac
*scmac_tobe
= NULL
;
2362 static const struct ssh_compress
*cscomp_tobe
= NULL
;
2363 static const struct ssh_compress
*sccomp_tobe
= NULL
;
2364 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
2365 static int hostkeylen
, siglen
;
2366 static void *hkey
; /* actual host key */
2367 static unsigned char exchange_hash
[20];
2368 static unsigned char keyspace
[40];
2369 static const struct ssh2_ciphers
*preferred_cipher
;
2370 static const struct ssh_compress
*preferred_comp
;
2371 static int first_kex
;
2378 * Set up the preferred cipher and compression.
2380 if (cfg
.cipher
== CIPHER_BLOWFISH
) {
2381 preferred_cipher
= &ssh2_blowfish
;
2382 } else if (cfg
.cipher
== CIPHER_DES
) {
2383 logevent("Single DES not supported in SSH2; using 3DES");
2384 preferred_cipher
= &ssh2_3des
;
2385 } else if (cfg
.cipher
== CIPHER_3DES
) {
2386 preferred_cipher
= &ssh2_3des
;
2387 } else if (cfg
.cipher
== CIPHER_AES
) {
2388 preferred_cipher
= &ssh2_aes
;
2390 /* Shouldn't happen, but we do want to initialise to _something_. */
2391 preferred_cipher
= &ssh2_3des
;
2393 if (cfg
.compression
)
2394 preferred_comp
= &ssh_zlib
;
2396 preferred_comp
= &ssh_comp_none
;
2399 * Be prepared to work around the buggy MAC problem.
2401 if (cfg
.buggymac
|| (ssh_remote_bugs
& BUG_SSH2_HMAC
))
2402 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
2404 maclist
= macs
, nmacs
= lenof(macs
);
2408 * Construct and send our key exchange packet.
2410 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
2411 for (i
= 0; i
< 16; i
++)
2412 ssh2_pkt_addbyte((unsigned char)random_byte());
2413 /* List key exchange algorithms. */
2414 ssh2_pkt_addstring_start();
2415 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2416 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
2417 if (i
< lenof(kex_algs
)-1)
2418 ssh2_pkt_addstring_str(",");
2420 /* List server host key algorithms. */
2421 ssh2_pkt_addstring_start();
2422 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2423 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
2424 if (i
< lenof(hostkey_algs
)-1)
2425 ssh2_pkt_addstring_str(",");
2427 /* List client->server encryption algorithms. */
2428 ssh2_pkt_addstring_start();
2429 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2430 const struct ssh2_ciphers
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2431 for (j
= 0; j
< c
->nciphers
; j
++) {
2432 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
2433 if (i
< lenof(ciphers
) || j
< c
->nciphers
-1)
2434 ssh2_pkt_addstring_str(",");
2437 /* List server->client encryption algorithms. */
2438 ssh2_pkt_addstring_start();
2439 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2440 const struct ssh2_ciphers
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2441 for (j
= 0; j
< c
->nciphers
; j
++) {
2442 ssh2_pkt_addstring_str(c
->list
[j
]->name
);
2443 if (i
< lenof(ciphers
) || j
< c
->nciphers
-1)
2444 ssh2_pkt_addstring_str(",");
2447 /* List client->server MAC algorithms. */
2448 ssh2_pkt_addstring_start();
2449 for (i
= 0; i
< nmacs
; i
++) {
2450 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2452 ssh2_pkt_addstring_str(",");
2454 /* List server->client MAC algorithms. */
2455 ssh2_pkt_addstring_start();
2456 for (i
= 0; i
< nmacs
; i
++) {
2457 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2459 ssh2_pkt_addstring_str(",");
2461 /* List client->server compression algorithms. */
2462 ssh2_pkt_addstring_start();
2463 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2464 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2465 ssh2_pkt_addstring_str(c
->name
);
2466 if (i
< lenof(compressions
))
2467 ssh2_pkt_addstring_str(",");
2469 /* List server->client compression algorithms. */
2470 ssh2_pkt_addstring_start();
2471 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2472 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2473 ssh2_pkt_addstring_str(c
->name
);
2474 if (i
< lenof(compressions
))
2475 ssh2_pkt_addstring_str(",");
2477 /* List client->server languages. Empty list. */
2478 ssh2_pkt_addstring_start();
2479 /* List server->client languages. Empty list. */
2480 ssh2_pkt_addstring_start();
2481 /* First KEX packet does _not_ follow, because we're not that brave. */
2482 ssh2_pkt_addbool(FALSE
);
2484 ssh2_pkt_adduint32(0);
2486 exhash
= exhashbase
;
2487 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
2491 if (!ispkt
) crWaitUntil(ispkt
);
2492 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
2495 * Now examine the other side's KEXINIT to see what we're up
2498 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
2499 bombout(("expected key exchange packet from server"));
2502 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
2503 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
2504 pktin
.savedpos
+= 16; /* skip garbage cookie */
2505 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
2506 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2507 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
2512 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
2513 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2514 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
2515 hostkey
= hostkey_algs
[i
];
2519 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
2520 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2521 const struct ssh2_ciphers
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2522 for (j
= 0; j
< c
->nciphers
; j
++) {
2523 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
2524 cscipher_tobe
= c
->list
[j
];
2531 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
2532 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2533 const struct ssh2_ciphers
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2534 for (j
= 0; j
< c
->nciphers
; j
++) {
2535 if (in_commasep_string(c
->list
[j
]->name
, str
, len
)) {
2536 sccipher_tobe
= c
->list
[j
];
2543 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
2544 for (i
= 0; i
< nmacs
; i
++) {
2545 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2546 csmac_tobe
= maclist
[i
];
2550 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
2551 for (i
= 0; i
< nmacs
; i
++) {
2552 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2553 scmac_tobe
= maclist
[i
];
2557 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
2558 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2559 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2560 if (in_commasep_string(c
->name
, str
, len
)) {
2565 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
2566 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2567 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2568 if (in_commasep_string(c
->name
, str
, len
)) {
2575 * Work out the number of bits of key we will need from the key
2576 * exchange. We start with the maximum key length of either
2582 csbits
= cscipher_tobe
->keylen
;
2583 scbits
= sccipher_tobe
->keylen
;
2584 nbits
= (csbits
> scbits ? csbits
: scbits
);
2586 /* The keys only have 160-bit entropy, since they're based on
2587 * a SHA-1 hash. So cap the key size at 160 bits. */
2588 if (nbits
> 160) nbits
= 160;
2591 * If we're doing Diffie-Hellman group exchange, start by
2592 * requesting a group.
2594 if (kex
== &ssh_diffiehellman_gex
) {
2595 logevent("Doing Diffie-Hellman group exchange");
2597 * Work out how big a DH group we will need to allow that
2600 pbits
= 512 << ((nbits
-1) / 64);
2601 ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST
);
2602 ssh2_pkt_adduint32(pbits
);
2606 if (pktin
.type
!= SSH2_MSG_KEX_DH_GEX_GROUP
) {
2607 bombout(("expected key exchange group packet from server"));
2610 p
= ssh2_pkt_getmp();
2611 g
= ssh2_pkt_getmp();
2612 dh_setup_group(p
, g
);
2613 kex_init_value
= SSH2_MSG_KEX_DH_GEX_INIT
;
2614 kex_reply_value
= SSH2_MSG_KEX_DH_GEX_REPLY
;
2617 kex_init_value
= SSH2_MSG_KEXDH_INIT
;
2618 kex_reply_value
= SSH2_MSG_KEXDH_REPLY
;
2621 logevent("Doing Diffie-Hellman key exchange");
2623 * Now generate and send e for Diffie-Hellman.
2625 e
= dh_create_e(nbits
*2);
2626 ssh2_pkt_init(kex_init_value
);
2631 if (pktin
.type
!= kex_reply_value
) {
2632 bombout(("expected key exchange reply packet from server"));
2635 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
2636 f
= ssh2_pkt_getmp();
2637 ssh2_pkt_getstring(&sigdata
, &siglen
);
2641 sha_string(&exhash
, hostkeydata
, hostkeylen
);
2642 if (kex
== &ssh_diffiehellman_gex
) {
2643 sha_uint32(&exhash
, pbits
);
2644 sha_mpint(&exhash
, p
);
2645 sha_mpint(&exhash
, g
);
2647 sha_mpint(&exhash
, e
);
2648 sha_mpint(&exhash
, f
);
2649 sha_mpint(&exhash
, K
);
2650 SHA_Final(&exhash
, exchange_hash
);
2655 debug(("Exchange hash is:\r\n"));
2656 for (i
= 0; i
< 20; i
++)
2657 debug((" %02x", exchange_hash
[i
]));
2661 hkey
= hostkey
->newkey(hostkeydata
, hostkeylen
);
2662 if (!hostkey
->verifysig(hkey
, sigdata
, siglen
, exchange_hash
, 20)) {
2663 bombout(("Server failed host key check"));
2668 * Expect SSH2_MSG_NEWKEYS from server.
2671 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
2672 bombout(("expected new-keys packet from server"));
2677 * Authenticate remote host: verify host key. (We've already
2678 * checked the signature of the exchange hash.)
2680 keystr
= hostkey
->fmtkey(hkey
);
2681 fingerprint
= hostkey
->fingerprint(hkey
);
2682 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
2683 keystr
, fingerprint
);
2684 if (first_kex
) { /* don't bother logging this in rekeys */
2685 logevent("Host key fingerprint is:");
2686 logevent(fingerprint
);
2690 hostkey
->freekey(hkey
);
2693 * Send SSH2_MSG_NEWKEYS.
2695 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
2699 * Create and initialise session keys.
2701 cscipher
= cscipher_tobe
;
2702 sccipher
= sccipher_tobe
;
2705 cscomp
= cscomp_tobe
;
2706 sccomp
= sccomp_tobe
;
2707 cscomp
->compress_init();
2708 sccomp
->decompress_init();
2710 * Set IVs after keys. Here we use the exchange hash from the
2711 * _first_ key exchange.
2714 memcpy(ssh2_session_id
, exchange_hash
, sizeof(exchange_hash
));
2715 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'C', keyspace
);
2716 cscipher
->setcskey(keyspace
);
2717 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'D', keyspace
);
2718 sccipher
->setsckey(keyspace
);
2719 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'A', keyspace
);
2720 cscipher
->setcsiv(keyspace
);
2721 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'B', keyspace
);
2722 sccipher
->setsciv(keyspace
);
2723 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'E', keyspace
);
2724 csmac
->setcskey(keyspace
);
2725 ssh2_mkkey(K
, exchange_hash
, ssh2_session_id
, 'F', keyspace
);
2726 scmac
->setsckey(keyspace
);
2729 * If this is the first key exchange phase, we must pass the
2730 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
2731 * wants to see it but because it will need time to initialise
2732 * itself before it sees an actual packet. In subsequent key
2733 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
2734 * it would only confuse the layer above.
2742 * Now we're encrypting. Begin returning 1 to the protocol main
2743 * function so that other things can run on top of the
2744 * transport. If we ever see a KEXINIT, we must go back to the
2747 while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
)) {
2750 logevent("Server initiated key re-exchange");
2751 goto begin_key_exchange
;
2757 * Add data to an SSH2 channel output buffer.
2759 static void ssh2_add_channel_data(struct ssh_channel
*c
, char *buf
, int len
) {
2760 if (c
->v2
.outbufsize
<
2761 c
->v2
.outbuflen
+ len
) {
2763 c
->v2
.outbuflen
+ len
+ 1024;
2764 c
->v2
.outbuffer
= srealloc(c
->v2
.outbuffer
,
2767 memcpy(c
->v2
.outbuffer
+ c
->v2
.outbuflen
,
2769 c
->v2
.outbuflen
+= len
;
2773 * Attempt to send data on an SSH2 channel.
2775 static void ssh2_try_send(struct ssh_channel
*c
) {
2776 while (c
->v2
.remwindow
> 0 &&
2777 c
->v2
.outbuflen
> 0) {
2778 unsigned len
= c
->v2
.remwindow
;
2779 if (len
> c
->v2
.outbuflen
)
2780 len
= c
->v2
.outbuflen
;
2781 if (len
> c
->v2
.remmaxpkt
)
2782 len
= c
->v2
.remmaxpkt
;
2783 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2784 ssh2_pkt_adduint32(c
->remoteid
);
2785 ssh2_pkt_addstring_start();
2786 ssh2_pkt_addstring_data(c
->v2
.outbuffer
, len
);
2788 c
->v2
.outbuflen
-= len
;
2789 memmove(c
->v2
.outbuffer
, c
->v2
.outbuffer
+len
,
2791 c
->v2
.remwindow
-= len
;
2796 * Handle the SSH2 userauth and connection layers.
2798 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
2800 static unsigned long remote_winsize
;
2801 static unsigned long remote_maxpkt
;
2803 AUTH_INVALID
, AUTH_PUBLICKEY_AGENT
, AUTH_PUBLICKEY_FILE
, AUTH_PASSWORD
2807 AUTH_TYPE_PUBLICKEY
,
2808 AUTH_TYPE_PUBLICKEY_OFFER_LOUD
,
2809 AUTH_TYPE_PUBLICKEY_OFFER_QUIET
,
2812 static int gotit
, need_pw
, can_pubkey
, can_passwd
;
2813 static int tried_pubkey_config
, tried_agent
;
2814 static int we_are_in
;
2815 static char username
[100];
2816 static char pwprompt
[200];
2817 static char password
[100];
2822 * Request userauth protocol, and await a response to it.
2824 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
2825 ssh2_pkt_addstring("ssh-userauth");
2827 crWaitUntilV(ispkt
);
2828 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
2829 bombout(("Server refused user authentication protocol"));
2834 * We repeat this whole loop, including the username prompt,
2835 * until we manage a successful authentication. If the user
2836 * types the wrong _password_, they are sent back to the
2837 * beginning to try another username. (If they specify a
2838 * username in the config, they are never asked, even if they
2839 * do give a wrong password.)
2841 * I think this best serves the needs of
2843 * - the people who have no configuration, no keys, and just
2844 * want to try repeated (username,password) pairs until they
2845 * type both correctly
2847 * - people who have keys and configuration but occasionally
2848 * need to fall back to passwords
2850 * - people with a key held in Pageant, who might not have
2851 * logged in to a particular machine before; so they want to
2852 * type a username, and then _either_ their key will be
2853 * accepted, _or_ they will type a password. If they mistype
2854 * the username they will want to be able to get back and
2865 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2867 if (!ssh_get_line("login as: ",
2868 username
, sizeof(username
), FALSE
)) {
2870 * get_line failed to get a username.
2873 logevent("No username provided. Abandoning session.");
2874 ssh_state
= SSH_STATE_CLOSED
;
2878 c_write_str("login as: ");
2881 crWaitUntilV(!ispkt
);
2882 while (inlen
--) switch (c
= *in
++) {
2889 c_write_str("\b \b");
2895 c_write_str("\b \b");
2904 if (((c
>= ' ' && c
<= '~') ||
2905 ((unsigned char)c
>= 160)) && pos
< 40) {
2906 username
[pos
++] = c
;
2913 c_write_str("\r\n");
2914 username
[strcspn(username
, "\n\r")] = '\0';
2917 strncpy(username
, cfg
.username
, 99);
2918 username
[99] = '\0';
2919 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
2920 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
2926 * Send an authentication request using method "none": (a)
2927 * just in case it succeeds, and (b) so that we know what
2928 * authentication methods we can usefully try next.
2930 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
2931 ssh2_pkt_addstring(username
);
2932 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2933 ssh2_pkt_addstring("none"); /* method */
2935 type
= AUTH_TYPE_NONE
;
2939 tried_pubkey_config
= FALSE
;
2940 tried_agent
= FALSE
;
2944 * Wait for the result of the last authentication request.
2947 crWaitUntilV(ispkt
);
2948 while (pktin
.type
== SSH2_MSG_USERAUTH_BANNER
) {
2949 /* FIXME: should support this */
2950 crWaitUntilV(ispkt
);
2952 if (pktin
.type
== SSH2_MSG_USERAUTH_SUCCESS
) {
2953 logevent("Access granted");
2958 if (pktin
.type
!= SSH2_MSG_USERAUTH_FAILURE
) {
2959 bombout(("Strange packet received during authentication: type %d",
2966 * OK, we're now sitting on a USERAUTH_FAILURE message, so
2967 * we can look at the string in it and know what we can
2968 * helpfully try next.
2973 ssh2_pkt_getstring(&methods
, &methlen
);
2974 if (!ssh2_pkt_getbool()) {
2976 * We have received an unequivocal Access
2977 * Denied. This can translate to a variety of
2980 * - if we'd just tried "none" authentication,
2981 * it's not worth printing anything at all
2983 * - if we'd just tried a public key _offer_,
2984 * the message should be "Server refused our
2985 * key" (or no message at all if the key
2986 * came from Pageant)
2988 * - if we'd just tried anything else, the
2989 * message really should be "Access denied".
2991 * Additionally, if we'd just tried password
2992 * authentication, we should break out of this
2993 * whole loop so as to go back to the username
2996 if (type
== AUTH_TYPE_NONE
) {
2998 } else if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
||
2999 type
== AUTH_TYPE_PUBLICKEY_OFFER_QUIET
) {
3000 if (type
== AUTH_TYPE_PUBLICKEY_OFFER_LOUD
)
3001 c_write_str("Server refused our key\r\n");
3002 logevent("Server refused public key");
3004 c_write_str("Access denied\r\n");
3005 logevent("Access denied");
3006 if (type
== AUTH_TYPE_PASSWORD
) {
3012 c_write_str("Further authentication required\r\n");
3013 logevent("Further authentication required");
3016 can_pubkey
= in_commasep_string("publickey", methods
, methlen
);
3017 can_passwd
= in_commasep_string("password", methods
, methlen
);
3022 if (!method
&& can_pubkey
&& agent_exists
&& !tried_agent
) {
3024 * Attempt public-key authentication using Pageant.
3026 static unsigned char request
[5], *response
, *p
;
3027 static int responselen
;
3028 static int i
, nkeys
;
3029 static int authed
= FALSE
;
3034 logevent("Pageant is running. Requesting keys.");
3036 /* Request the keys held by the agent. */
3037 PUT_32BIT(request
, 1);
3038 request
[4] = SSH2_AGENTC_REQUEST_IDENTITIES
;
3039 agent_query(request
, 5, &r
, &responselen
);
3040 response
= (unsigned char *)r
;
3041 if (response
&& responselen
>= 5 &&
3042 response
[4] == SSH2_AGENT_IDENTITIES_ANSWER
) {
3044 nkeys
= GET_32BIT(p
); p
+= 4;
3045 { char buf
[64]; sprintf(buf
, "Pageant has %d SSH2 keys", nkeys
);
3047 for (i
= 0; i
< nkeys
; i
++) {
3048 static char *pkblob
, *alg
, *commentp
;
3049 static int pklen
, alglen
, commentlen
;
3050 static int siglen
, retlen
, len
;
3051 static char *q
, *agentreq
, *ret
;
3053 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
3055 pklen
= GET_32BIT(p
); p
+= 4;
3056 pkblob
= p
; p
+= pklen
;
3057 alglen
= GET_32BIT(pkblob
);
3059 commentlen
= GET_32BIT(p
); p
+= 4;
3060 commentp
= p
; p
+= commentlen
;
3061 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3062 ssh2_pkt_addstring(username
);
3063 ssh2_pkt_addstring("ssh-connection");/* service requested */
3064 ssh2_pkt_addstring("publickey");/* method */
3065 ssh2_pkt_addbool(FALSE
); /* no signature included */
3066 ssh2_pkt_addstring_start();
3067 ssh2_pkt_addstring_data(alg
, alglen
);
3068 ssh2_pkt_addstring_start();
3069 ssh2_pkt_addstring_data(pkblob
, pklen
);
3072 crWaitUntilV(ispkt
);
3073 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
3074 logevent("Key refused");
3078 c_write_str("Authenticating with public key \"");
3079 c_write(commentp
, commentlen
);
3080 c_write_str("\" from agent\r\n");
3083 * Server is willing to accept the key.
3084 * Construct a SIGN_REQUEST.
3086 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3087 ssh2_pkt_addstring(username
);
3088 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3089 ssh2_pkt_addstring("publickey"); /* method */
3090 ssh2_pkt_addbool(TRUE
);
3091 ssh2_pkt_addstring_start();
3092 ssh2_pkt_addstring_data(alg
, alglen
);
3093 ssh2_pkt_addstring_start();
3094 ssh2_pkt_addstring_data(pkblob
, pklen
);
3096 siglen
= pktout
.length
- 5 + 4 + 20;
3097 len
= 1; /* message type */
3098 len
+= 4 + pklen
; /* key blob */
3099 len
+= 4 + siglen
; /* data to sign */
3100 len
+= 4; /* flags */
3101 agentreq
= smalloc(4 + len
);
3102 PUT_32BIT(agentreq
, len
);
3104 *q
++ = SSH2_AGENTC_SIGN_REQUEST
;
3105 PUT_32BIT(q
, pklen
); q
+= 4;
3106 memcpy(q
, pkblob
, pklen
); q
+= pklen
;
3107 PUT_32BIT(q
, siglen
); q
+= 4;
3108 /* Now the data to be signed... */
3109 PUT_32BIT(q
, 20); q
+= 4;
3110 memcpy(q
, ssh2_session_id
, 20); q
+= 20;
3111 memcpy(q
, pktout
.data
+5, pktout
.length
-5);
3112 q
+= pktout
.length
-5;
3113 /* And finally the (zero) flags word. */
3115 agent_query(agentreq
, len
+4, &ret
, &retlen
);
3118 if (ret
[4] == SSH2_AGENT_SIGN_RESPONSE
) {
3119 logevent("Sending Pageant's response");
3120 ssh2_pkt_addstring_start();
3121 ssh2_pkt_addstring_data(ret
+9, GET_32BIT(ret
+5));
3126 logevent("Pageant failed to answer challenge");
3136 if (!method
&& can_pubkey
&& *cfg
.keyfile
&& !tried_pubkey_config
) {
3137 unsigned char *pub_blob
;
3138 char *algorithm
, *comment
;
3141 tried_pubkey_config
= TRUE
;
3144 * Try the public key supplied in the configuration.
3146 * First, offer the public blob to see if the server is
3147 * willing to accept it.
3149 pub_blob
= ssh2_userkey_loadpub(cfg
.keyfile
, &algorithm
,
3152 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3153 ssh2_pkt_addstring(username
);
3154 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3155 ssh2_pkt_addstring("publickey");/* method */
3156 ssh2_pkt_addbool(FALSE
); /* no signature included */
3157 ssh2_pkt_addstring(algorithm
);
3158 ssh2_pkt_addstring_start();
3159 ssh2_pkt_addstring_data(pub_blob
, pub_blob_len
);
3161 logevent("Offered public key"); /* FIXME */
3163 crWaitUntilV(ispkt
);
3164 if (pktin
.type
!= SSH2_MSG_USERAUTH_PK_OK
) {
3166 type
= AUTH_TYPE_PUBLICKEY_OFFER_LOUD
;
3167 continue; /* key refused; give up on it */
3170 logevent("Offer of public key accepted");
3172 * Actually attempt a serious authentication using
3175 if (ssh2_userkey_encrypted(cfg
.keyfile
, &comment
)) {
3176 sprintf(pwprompt
, "Passphrase for key \"%.100s\": ", comment
);
3181 c_write_str("Authenticating with public key \"");
3182 c_write_str(comment
);
3183 c_write_str("\"\r\n");
3184 method
= AUTH_PUBLICKEY_FILE
;
3188 if (!method
&& can_passwd
) {
3189 method
= AUTH_PASSWORD
;
3190 sprintf(pwprompt
, "%.90s@%.90s's password: ", username
, savedhost
);
3196 if (!ssh_get_line(pwprompt
, password
,
3197 sizeof(password
), TRUE
)) {
3199 * get_line failed to get a password (for
3200 * example because one was supplied on the
3201 * command line which has already failed to
3204 logevent("No more passwords to try");
3205 ssh_state
= SSH_STATE_CLOSED
;
3212 c_write_str(pwprompt
);
3217 crWaitUntilV(!ispkt
);
3218 while (inlen
--) switch (c
= *in
++) {
3235 if (((c
>= ' ' && c
<= '~') ||
3236 ((unsigned char)c
>= 160)) && pos
< 40)
3237 password
[pos
++] = c
;
3241 c_write_str("\r\n");
3245 if (method
== AUTH_PUBLICKEY_FILE
) {
3247 * We have our passphrase. Now try the actual authentication.
3249 struct ssh2_userkey
*key
;
3251 key
= ssh2_load_userkey(cfg
.keyfile
, password
);
3252 if (key
== SSH2_WRONG_PASSPHRASE
|| key
== NULL
) {
3253 if (key
== SSH2_WRONG_PASSPHRASE
) {
3254 c_write_str("Wrong passphrase\r\n");
3255 tried_pubkey_config
= FALSE
;
3257 c_write_str("Unable to load private key\r\n");
3258 tried_pubkey_config
= TRUE
;
3260 /* Send a spurious AUTH_NONE to return to the top. */
3261 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3262 ssh2_pkt_addstring(username
);
3263 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3264 ssh2_pkt_addstring("none"); /* method */
3266 type
= AUTH_TYPE_NONE
;
3268 unsigned char *blob
, *sigdata
;
3269 int blob_len
, sigdata_len
;
3272 * We have loaded the private key and the server
3273 * has announced that it's willing to accept it.
3274 * Hallelujah. Generate a signature and send it.
3276 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3277 ssh2_pkt_addstring(username
);
3278 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3279 ssh2_pkt_addstring("publickey"); /* method */
3280 ssh2_pkt_addbool(TRUE
);
3281 ssh2_pkt_addstring(key
->alg
->name
);
3282 blob
= key
->alg
->public_blob(key
->data
, &blob_len
);
3283 ssh2_pkt_addstring_start();
3284 ssh2_pkt_addstring_data(blob
, blob_len
);
3288 * The data to be signed is:
3292 * followed by everything so far placed in the
3295 sigdata_len
= pktout
.length
- 5 + 4 + 20;
3296 sigdata
= smalloc(sigdata_len
);
3297 PUT_32BIT(sigdata
, 20);
3298 memcpy(sigdata
+4, ssh2_session_id
, 20);
3299 memcpy(sigdata
+24, pktout
.data
+5, pktout
.length
-5);
3300 blob
= key
->alg
->sign(key
->data
, sigdata
, sigdata_len
, &blob_len
);
3301 ssh2_pkt_addstring_start();
3302 ssh2_pkt_addstring_data(blob
, blob_len
);
3307 type
= AUTH_TYPE_PUBLICKEY
;
3309 } else if (method
== AUTH_PASSWORD
) {
3311 * We send the password packet lumped tightly together with
3312 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
3313 * string long enough to make the total length of the two
3314 * packets constant. This should ensure that a passive
3315 * listener doing traffic analyis can't work out the length
3318 * For this to work, we need an assumption about the
3319 * maximum length of the password packet. I think 256 is
3320 * pretty conservative. Anyone using a password longer than
3321 * that probably doesn't have much to worry about from
3322 * people who find out how long their password is!
3324 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
3325 ssh2_pkt_addstring(username
);
3326 ssh2_pkt_addstring("ssh-connection"); /* service requested */
3327 ssh2_pkt_addstring("password");
3328 ssh2_pkt_addbool(FALSE
);
3329 ssh2_pkt_addstring(password
);
3332 * We'll include a string that's an exact multiple of the
3333 * cipher block size. If the cipher is NULL for some
3334 * reason, we don't do this trick at all because we gain
3340 stringlen
= (256 - deferred_len
);
3341 stringlen
+= cscipher
->blksize
- 1;
3342 stringlen
-= (stringlen
% cscipher
->blksize
);
3345 * Temporarily disable actual compression,
3346 * so we can guarantee to get this string
3347 * exactly the length we want it. The
3348 * compression-disabling routine should
3349 * return an integer indicating how many
3350 * bytes we should adjust our string length
3353 stringlen
-= cscomp
->disable_compression();
3355 ssh2_pkt_init(SSH2_MSG_IGNORE
);
3356 ssh2_pkt_addstring_start();
3357 for (i
= 0; i
< stringlen
; i
++) {
3358 char c
= (char)random_byte();
3359 ssh2_pkt_addstring_data(&c
, 1);
3363 ssh_pkt_defersend();
3364 logevent("Sent password");
3365 type
= AUTH_TYPE_PASSWORD
;
3367 c_write_str("No supported authentication methods left to try!\r\n");
3368 logevent("No supported authentications offered. Disconnecting");
3369 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3370 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
3371 ssh2_pkt_addstring("No supported authentication methods available");
3372 ssh2_pkt_addstring("en"); /* language tag */
3374 ssh_state
= SSH_STATE_CLOSED
;
3378 } while (!we_are_in
);
3381 * Now we're authenticated for the connection protocol. The
3382 * connection protocol will automatically have started at this
3383 * point; there's no need to send SERVICE_REQUEST.
3387 * So now create a channel with a session in it.
3389 mainchan
= smalloc(sizeof(struct ssh_channel
));
3390 mainchan
->localid
= 100; /* as good as any */
3391 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
3392 ssh2_pkt_addstring("session");
3393 ssh2_pkt_adduint32(mainchan
->localid
);
3394 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
3395 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
3397 crWaitUntilV(ispkt
);
3398 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
3399 bombout(("Server refused to open a session"));
3401 /* FIXME: error data comes back in FAILURE packet */
3403 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
3404 bombout(("Server's channel confirmation cited wrong channel"));
3407 mainchan
->remoteid
= ssh2_pkt_getuint32();
3408 mainchan
->type
= CHAN_MAINSESSION
;
3409 mainchan
->closes
= 0;
3410 mainchan
->v2
.remwindow
= ssh2_pkt_getuint32();
3411 mainchan
->v2
.remmaxpkt
= ssh2_pkt_getuint32();
3412 mainchan
->v2
.outbuffer
= NULL
;
3413 mainchan
->v2
.outbuflen
= mainchan
->v2
.outbufsize
= 0;
3414 ssh_channels
= newtree234(ssh_channelcmp
);
3415 add234(ssh_channels
, mainchan
);
3416 logevent("Opened channel for session");
3419 * Potentially enable X11 forwarding.
3421 if (cfg
.x11_forward
) {
3422 char proto
[20], data
[64];
3423 logevent("Requesting X11 forwarding");
3424 x11_invent_auth(proto
, sizeof(proto
), data
, sizeof(data
));
3425 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3426 ssh2_pkt_adduint32(mainchan
->remoteid
);
3427 ssh2_pkt_addstring("x11-req");
3428 ssh2_pkt_addbool(1); /* want reply */
3429 ssh2_pkt_addbool(0); /* many connections */
3430 ssh2_pkt_addstring(proto
);
3431 ssh2_pkt_addstring(data
);
3432 ssh2_pkt_adduint32(0); /* screen number */
3436 crWaitUntilV(ispkt
);
3437 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3438 unsigned i
= ssh2_pkt_getuint32();
3439 struct ssh_channel
*c
;
3440 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3442 continue; /* nonexistent channel */
3443 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3445 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3447 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
3448 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
3449 bombout(("Server got confused by X11 forwarding request"));
3452 logevent("X11 forwarding refused");
3454 logevent("X11 forwarding enabled");
3455 ssh_X11_fwd_enabled
= TRUE
;
3460 * Potentially enable agent forwarding.
3462 if (cfg
.agentfwd
&& agent_exists()) {
3463 logevent("Requesting OpenSSH-style agent forwarding");
3464 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3465 ssh2_pkt_adduint32(mainchan
->remoteid
);
3466 ssh2_pkt_addstring("auth-agent-req@openssh.com");
3467 ssh2_pkt_addbool(1); /* want reply */
3471 crWaitUntilV(ispkt
);
3472 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3473 unsigned i
= ssh2_pkt_getuint32();
3474 struct ssh_channel
*c
;
3475 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3477 continue; /* nonexistent channel */
3478 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3480 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3482 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
3483 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
3484 bombout(("Server got confused by agent forwarding request"));
3487 logevent("Agent forwarding refused");
3489 logevent("Agent forwarding enabled");
3490 ssh_agentfwd_enabled
= TRUE
;
3495 * Now allocate a pty for the session.
3498 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3499 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
3500 ssh2_pkt_addstring("pty-req");
3501 ssh2_pkt_addbool(1); /* want reply */
3502 ssh2_pkt_addstring(cfg
.termtype
);
3503 ssh2_pkt_adduint32(cols
);
3504 ssh2_pkt_adduint32(rows
);
3505 ssh2_pkt_adduint32(0); /* pixel width */
3506 ssh2_pkt_adduint32(0); /* pixel height */
3507 ssh2_pkt_addstring_start();
3508 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
3510 ssh_state
= SSH_STATE_INTERMED
;
3513 crWaitUntilV(ispkt
);
3514 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3515 unsigned i
= ssh2_pkt_getuint32();
3516 struct ssh_channel
*c
;
3517 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3519 continue; /* nonexistent channel */
3520 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3522 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3524 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
3525 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
3526 bombout(("Server got confused by pty request"));
3529 c_write_str("Server refused to allocate pty\r\n");
3530 ssh_editing
= ssh_echoing
= 1;
3532 logevent("Allocated pty");
3535 ssh_editing
= ssh_echoing
= 1;
3539 * Start a shell or a remote command.
3541 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3542 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
3543 if (cfg
.ssh_subsys
) {
3544 ssh2_pkt_addstring("subsystem");
3545 ssh2_pkt_addbool(1); /* want reply */
3546 ssh2_pkt_addstring(cfg
.remote_cmd
);
3547 } else if (*cfg
.remote_cmd
) {
3548 ssh2_pkt_addstring("exec");
3549 ssh2_pkt_addbool(1); /* want reply */
3550 ssh2_pkt_addstring(cfg
.remote_cmd
);
3552 ssh2_pkt_addstring("shell");
3553 ssh2_pkt_addbool(1); /* want reply */
3557 crWaitUntilV(ispkt
);
3558 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3559 unsigned i
= ssh2_pkt_getuint32();
3560 struct ssh_channel
*c
;
3561 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3563 continue; /* nonexistent channel */
3564 c
->v2
.remwindow
+= ssh2_pkt_getuint32();
3566 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3567 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
3568 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
3569 bombout(("Server got confused by shell/command request"));
3572 bombout(("Server refused to start a shell/command"));
3575 logevent("Started a shell/command");
3578 ssh_state
= SSH_STATE_SESSION
;
3582 ssh_special(TS_EOF
);
3587 ldisc_send(NULL
, 0); /* cause ldisc to notice changes */
3590 static int try_send
;
3594 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
3595 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
3598 unsigned i
= ssh2_pkt_getuint32();
3599 struct ssh_channel
*c
;
3600 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3602 continue; /* nonexistent channel */
3603 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
3604 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
3605 continue; /* extended but not stderr */
3606 ssh2_pkt_getstring(&data
, &length
);
3609 case CHAN_MAINSESSION
:
3610 from_backend(pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
,
3614 x11_send(c
->u
.x11
.s
, data
, length
);
3617 while (length
> 0) {
3618 if (c
->u
.a
.lensofar
< 4) {
3619 int l
= min(4 - c
->u
.a
.lensofar
, length
);
3620 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, data
, l
);
3621 data
+= l
; length
-= l
; c
->u
.a
.lensofar
+= l
;
3623 if (c
->u
.a
.lensofar
== 4) {
3624 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
3625 c
->u
.a
.message
= smalloc(c
->u
.a
.totallen
);
3626 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
3628 if (c
->u
.a
.lensofar
>= 4 && length
> 0) {
3629 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
,
3631 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, data
, l
);
3632 data
+= l
; length
-= l
; c
->u
.a
.lensofar
+= l
;
3634 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
3635 void *reply
, *sentreply
;
3637 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
3642 /* Fake SSH_AGENT_FAILURE. */
3643 sentreply
= "\0\0\0\1\5";
3646 ssh2_add_channel_data(c
, sentreply
, replylen
);
3650 sfree(c
->u
.a
.message
);
3651 c
->u
.a
.lensofar
= 0;
3657 * Enlarge the window again at the remote
3658 * side, just in case it ever runs down and
3659 * they fail to send us any more data.
3661 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
3662 ssh2_pkt_adduint32(c
->remoteid
);
3663 ssh2_pkt_adduint32(length
);
3666 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
3667 ssh_state
= SSH_STATE_CLOSED
;
3668 logevent("Received disconnect message");
3670 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
3671 continue; /* exit status et al; ignore (FIXME?) */
3672 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
3673 unsigned i
= ssh2_pkt_getuint32();
3674 struct ssh_channel
*c
;
3676 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3678 continue; /* nonexistent channel */
3680 if (c
->type
== CHAN_X11
) {
3682 * Remote EOF on an X11 channel means we should
3683 * wrap up and close the channel ourselves.
3685 x11_close(c
->u
.x11
.s
);
3687 } else if (c
->type
== CHAN_AGENT
) {
3690 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
3691 unsigned i
= ssh2_pkt_getuint32();
3692 struct ssh_channel
*c
;
3695 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3697 continue; /* nonexistent channel */
3698 if (c
->closes
== 0) {
3699 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
3700 ssh2_pkt_adduint32(c
->remoteid
);
3703 /* Do pre-close processing on the channel. */
3705 case CHAN_MAINSESSION
:
3706 break; /* nothing to see here, move along */
3712 del234(ssh_channels
, c
);
3713 sfree(c
->v2
.outbuffer
);
3717 * See if that was the last channel left open.
3719 c
= first234(ssh_channels
, &e
);
3721 logevent("All channels closed. Disconnecting");
3722 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
3723 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
3724 ssh2_pkt_addstring("All open channels closed");
3725 ssh2_pkt_addstring("en"); /* language tag */
3727 ssh_state
= SSH_STATE_CLOSED
;
3730 continue; /* remote sends close; ignore (FIXME) */
3731 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
3732 unsigned i
= ssh2_pkt_getuint32();
3733 struct ssh_channel
*c
;
3734 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
3736 continue; /* nonexistent channel */
3737 mainchan
->v2
.remwindow
+= ssh2_pkt_getuint32();
3739 } else if (pktin
.type
== SSH2_MSG_CHANNEL_OPEN
) {
3743 struct ssh_channel
*c
;
3744 ssh2_pkt_getstring(&type
, &typelen
);
3745 c
= smalloc(sizeof(struct ssh_channel
));
3747 if (typelen
== 3 && !memcmp(type
, "x11", 3)) {
3748 if (!ssh_X11_fwd_enabled
)
3749 error
= "X11 forwarding is not enabled";
3750 else if ( x11_init(&c
->u
.x11
.s
, cfg
.x11_display
, c
) != NULL
) {
3751 error
= "Unable to open an X11 connection";
3755 } else if (typelen
== 22 &&
3756 !memcmp(type
, "auth-agent@openssh.com", 3)) {
3757 if (!ssh_agentfwd_enabled
)
3758 error
= "Agent forwarding is not enabled";
3760 c
->type
= CHAN_AGENT
; /* identify channel type */
3761 c
->u
.a
.lensofar
= 0;
3764 error
= "Unsupported channel type requested";
3767 c
->remoteid
= ssh2_pkt_getuint32();
3769 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE
);
3770 ssh2_pkt_adduint32(c
->remoteid
);
3771 ssh2_pkt_adduint32(SSH2_OPEN_CONNECT_FAILED
);
3772 ssh2_pkt_addstring(error
);
3773 ssh2_pkt_addstring("en"); /* language tag */
3777 struct ssh_channel
*d
;
3781 for (i
=1, d
= first234(ssh_channels
, &e
); d
;
3784 break; /* found a free number */
3789 c
->v2
.remwindow
= ssh2_pkt_getuint32();
3790 c
->v2
.remmaxpkt
= ssh2_pkt_getuint32();
3791 c
->v2
.outbuffer
= NULL
;
3792 c
->v2
.outbuflen
= c
->v2
.outbufsize
= 0;
3793 add234(ssh_channels
, c
);
3794 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
);
3795 ssh2_pkt_adduint32(c
->remoteid
);
3796 ssh2_pkt_adduint32(c
->localid
);
3797 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
3798 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
3802 bombout(("Strange packet received: type %d", pktin
.type
));
3807 * We have spare data. Add it to the channel buffer.
3809 ssh2_add_channel_data(mainchan
, in
, inlen
);
3814 struct ssh_channel
*c
;
3816 * Try to send data on all channels if we can.
3818 for (c
= first234(ssh_channels
, &e
); c
; c
= next234(&e
))
3827 * Handle the top-level SSH2 protocol.
3829 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
3831 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
3833 do_ssh2_authconn(in
, inlen
, ispkt
);
3837 * Called to set up the connection.
3839 * Returns an error message, or NULL on success.
3841 static char *ssh_init (char *host
, int port
, char **realhost
) {
3845 if(crypto_startup() == 0)
3846 return "Microsoft high encryption pack not installed!";
3853 p
= connect_to_host(host
, port
, realhost
);
3861 * Called to send data down the Telnet connection.
3863 static void ssh_send (char *buf
, int len
) {
3864 if (s
== NULL
|| ssh_protocol
== NULL
)
3867 ssh_protocol(buf
, len
, 0);
3871 * Called to set the size of the window from SSH's POV.
3873 static void ssh_size(void) {
3874 switch (ssh_state
) {
3875 case SSH_STATE_BEFORE_SIZE
:
3876 case SSH_STATE_PREPACKET
:
3877 case SSH_STATE_CLOSED
:
3878 break; /* do nothing */
3879 case SSH_STATE_INTERMED
:
3880 size_needed
= TRUE
; /* buffer for later */
3882 case SSH_STATE_SESSION
:
3884 if (ssh_version
== 1) {
3885 send_packet(SSH1_CMSG_WINDOW_SIZE
,
3886 PKT_INT
, rows
, PKT_INT
, cols
,
3887 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
3889 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
3890 ssh2_pkt_adduint32(mainchan
->remoteid
);
3891 ssh2_pkt_addstring("window-change");
3892 ssh2_pkt_addbool(0);
3893 ssh2_pkt_adduint32(cols
);
3894 ssh2_pkt_adduint32(rows
);
3895 ssh2_pkt_adduint32(0);
3896 ssh2_pkt_adduint32(0);
3905 * Send Telnet special codes. TS_EOF is useful for `plink', so you
3906 * can send an EOF and collect resulting output (e.g. `plink
3909 static void ssh_special (Telnet_Special code
) {
3910 if (code
== TS_EOF
) {
3911 if (ssh_state
!= SSH_STATE_SESSION
) {
3913 * Buffer the EOF in case we are pre-SESSION, so we can
3914 * send it as soon as we reach SESSION.
3920 if (ssh_version
== 1) {
3921 send_packet(SSH1_CMSG_EOF
, PKT_END
);
3923 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
3924 ssh2_pkt_adduint32(mainchan
->remoteid
);
3927 logevent("Sent EOF message");
3928 } else if (code
== TS_PING
) {
3929 if (ssh_state
== SSH_STATE_CLOSED
|| ssh_state
== SSH_STATE_PREPACKET
)
3931 if (ssh_version
== 1) {
3932 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
3934 ssh2_pkt_init(SSH2_MSG_IGNORE
);
3935 ssh2_pkt_addstring_start();
3943 static Socket
ssh_socket(void) { return s
; }
3945 static int ssh_sendok(void) { return ssh_send_ok
; }
3947 static int ssh_ldisc(int option
) {
3948 if (option
== LD_ECHO
) return ssh_echoing
;
3949 if (option
== LD_EDIT
) return ssh_editing
;
3953 Backend ssh_backend
= {