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, sk_close(s), \
23 s = NULL, connection_fatal msg )
25 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
26 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
27 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
28 #define SSH1_CMSG_USER 4 /* 0x4 */
29 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
30 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
31 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
32 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
33 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
34 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
35 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
36 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
37 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
38 #define SSH1_SMSG_FAILURE 15 /* 0xf */
39 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
40 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
41 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
42 #define SSH1_CMSG_EOF 19 /* 0x13 */
43 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
44 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
45 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
46 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
47 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
48 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
49 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
50 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
51 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
52 #define SSH1_MSG_IGNORE 32 /* 0x20 */
53 #define SSH1_MSG_DEBUG 36 /* 0x24 */
54 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
55 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
56 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
57 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
58 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
59 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
60 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
62 #define SSH1_AUTH_TIS 5 /* 0x5 */
63 #define SSH1_AUTH_CCARD 16 /* 0x10 */
65 #define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
66 #define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
67 #define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
68 #define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
69 #define SSH_AGENT_FAILURE 5 /* 0x5 */
70 #define SSH_AGENT_SUCCESS 6 /* 0x6 */
71 #define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
72 #define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
74 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
75 #define SSH2_MSG_IGNORE 2 /* 0x2 */
76 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
77 #define SSH2_MSG_DEBUG 4 /* 0x4 */
78 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
79 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
80 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
81 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
82 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
83 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
84 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
85 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
86 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
87 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
88 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
89 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
90 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
91 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
92 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
93 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
94 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
95 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
96 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
97 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
98 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
99 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
100 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
101 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
102 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
103 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
105 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
106 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
107 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
108 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
109 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
110 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
111 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
112 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
113 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
114 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
115 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
117 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
118 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
119 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
120 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
122 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
124 #define GET_32BIT(cp) \
125 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
126 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
127 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
128 ((unsigned long)(unsigned char)(cp)[3]))
130 #define PUT_32BIT(cp, value) { \
131 (cp)[0] = (unsigned char)((value) >> 24); \
132 (cp)[1] = (unsigned char)((value) >> 16); \
133 (cp)[2] = (unsigned char)((value) >> 8); \
134 (cp)[3] = (unsigned char)(value); }
136 enum { PKT_END
, PKT_INT
, PKT_CHAR
, PKT_DATA
, PKT_STR
, PKT_BIGNUM
};
138 /* Coroutine mechanics for the sillier bits of the code */
139 #define crBegin1 static int crLine = 0;
140 #define crBegin2 switch(crLine) { case 0:;
141 #define crBegin crBegin1; crBegin2;
142 #define crFinish(z) } crLine = 0; return (z)
143 #define crFinishV } crLine = 0; return
144 #define crReturn(z) \
146 crLine=__LINE__; return (z); case __LINE__:;\
150 crLine=__LINE__; return; case __LINE__:;\
152 #define crStop(z) do{ crLine = 0; return (z); }while(0)
153 #define crStopV do{ crLine = 0; return; }while(0)
154 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
155 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
157 extern const struct ssh_cipher ssh_3des
;
158 extern const struct ssh_cipher ssh_3des_ssh2
;
159 extern const struct ssh_cipher ssh_des
;
160 extern const struct ssh_cipher ssh_blowfish_ssh1
;
161 extern const struct ssh_cipher ssh_blowfish_ssh2
;
164 * Ciphers for SSH2. We miss out single-DES because it isn't
165 * supported; also 3DES and Blowfish are both done differently from
166 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
167 * endianness and different-sized keys.)
169 const static struct ssh_cipher
*ciphers
[] = { &ssh_blowfish_ssh2
, &ssh_3des_ssh2
};
171 extern const struct ssh_kex ssh_diffiehellman
;
172 const static struct ssh_kex
*kex_algs
[] = { &ssh_diffiehellman
};
174 extern const struct ssh_hostkey ssh_dss
;
175 const static struct ssh_hostkey
*hostkey_algs
[] = { &ssh_dss
};
177 extern const struct ssh_mac ssh_md5
, ssh_sha1
, ssh_sha1_buggy
;
179 static void nullmac_key(unsigned char *key
) { }
180 static void nullmac_generate(unsigned char *blk
, int len
, unsigned long seq
) { }
181 static int nullmac_verify(unsigned char *blk
, int len
, unsigned long seq
) { return 1; }
182 const static struct ssh_mac ssh_mac_none
= {
183 nullmac_key
, nullmac_key
, nullmac_generate
, nullmac_verify
, "none", 0
185 const static struct ssh_mac
*macs
[] = {
186 &ssh_sha1
, &ssh_md5
, &ssh_mac_none
};
187 const static struct ssh_mac
*buggymacs
[] = {
188 &ssh_sha1_buggy
, &ssh_md5
, &ssh_mac_none
};
190 static void ssh_comp_none_init(void) { }
191 static int ssh_comp_none_block(unsigned char *block
, int len
,
192 unsigned char **outblock
, int *outlen
) {
195 const static struct ssh_compress ssh_comp_none
= {
197 ssh_comp_none_init
, ssh_comp_none_block
,
198 ssh_comp_none_init
, ssh_comp_none_block
200 extern const struct ssh_compress ssh_zlib
;
201 const static struct ssh_compress
*compressions
[] = {
202 &ssh_zlib
, &ssh_comp_none
};
205 * 2-3-4 tree storing channels.
208 unsigned remoteid
, localid
;
212 struct ssh_agent_channel
{
213 unsigned char *message
;
214 unsigned char msglen
[4];
215 int lensofar
, totallen
;
217 struct ssh2_data_channel
{
218 unsigned char *outbuffer
;
219 unsigned outbuflen
, outbufsize
;
220 unsigned remwindow
, remmaxpkt
;
234 static SHA_State exhash
;
236 static Socket s
= NULL
;
238 static unsigned char session_key
[32];
239 static int ssh1_compressing
;
240 static const struct ssh_cipher
*cipher
= NULL
;
241 static const struct ssh_cipher
*cscipher
= NULL
;
242 static const struct ssh_cipher
*sccipher
= NULL
;
243 static const struct ssh_mac
*csmac
= NULL
;
244 static const struct ssh_mac
*scmac
= NULL
;
245 static const struct ssh_compress
*cscomp
= NULL
;
246 static const struct ssh_compress
*sccomp
= NULL
;
247 static const struct ssh_kex
*kex
= NULL
;
248 static const struct ssh_hostkey
*hostkey
= NULL
;
249 int (*ssh_get_password
)(const char *prompt
, char *str
, int maxlen
) = NULL
;
251 static char *savedhost
;
252 static int savedport
;
253 static int ssh_send_ok
;
255 static tree234
*ssh_channels
; /* indexed by local id */
256 static struct ssh_channel
*mainchan
; /* primary session channel */
259 SSH_STATE_BEFORE_SIZE
,
263 } ssh_state
= SSH_STATE_BEFORE_SIZE
;
265 static int size_needed
= FALSE
;
267 static struct Packet pktin
= { 0, 0, NULL
, NULL
, 0 };
268 static struct Packet pktout
= { 0, 0, NULL
, NULL
, 0 };
270 static int ssh_version
;
271 static void (*ssh_protocol
)(unsigned char *in
, int inlen
, int ispkt
);
272 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
);
273 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
);
274 static void ssh_size(void);
276 static int (*s_rdpkt
)(unsigned char **data
, int *datalen
);
278 static struct rdpkt1_state_tag
{
279 long len
, pad
, biglen
, to_read
;
280 unsigned long realcrc
, gotcrc
;
286 static struct rdpkt2_state_tag
{
287 long len
, pad
, payload
, packetlen
, maclen
;
290 unsigned long incoming_sequence
;
293 static int ssh_channelcmp(void *av
, void *bv
) {
294 struct ssh_channel
*a
= (struct ssh_channel
*)av
;
295 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
296 if (a
->localid
< b
->localid
) return -1;
297 if (a
->localid
> b
->localid
) return +1;
300 static int ssh_channelfind(void *av
, void *bv
) {
301 unsigned *a
= (unsigned *)av
;
302 struct ssh_channel
*b
= (struct ssh_channel
*)bv
;
303 if (*a
< b
->localid
) return -1;
304 if (*a
> b
->localid
) return +1;
308 static void c_write (char *buf
, int len
) {
309 if ((flags
& FLAG_STDERR
)) {
311 for (i
= 0; i
< len
; i
++)
313 fputc(buf
[i
], stderr
);
316 from_backend(1, buf
, len
);
320 * Collect incoming data in the incoming packet buffer.
321 * Decipher and verify the packet when it is completely read.
322 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
323 * Update the *data and *datalen variables.
324 * Return the additional nr of bytes needed, or 0 when
325 * a complete packet is available.
327 static int ssh1_rdpkt(unsigned char **data
, int *datalen
)
329 struct rdpkt1_state_tag
*st
= &rdpkt1_state
;
338 for (st
->i
= st
->len
= 0; st
->i
< 4; st
->i
++) {
339 while ((*datalen
) == 0)
341 st
->len
= (st
->len
<< 8) + **data
;
342 (*data
)++, (*datalen
)--;
346 if (st
->len
== 0x52656d6f) { /* "Remo"te server has closed ... */
347 st
->len
= 0x300; /* big enough to carry to end */
351 st
->pad
= 8 - (st
->len
% 8);
352 st
->biglen
= st
->len
+ st
->pad
;
353 pktin
.length
= st
->len
- 5;
355 if (pktin
.maxlen
< st
->biglen
) {
356 pktin
.maxlen
= st
->biglen
;
357 pktin
.data
= (pktin
.data
== NULL ?
malloc(st
->biglen
+APIEXTRA
) :
358 realloc(pktin
.data
, st
->biglen
+APIEXTRA
));
360 fatalbox("Out of memory");
363 st
->to_read
= st
->biglen
;
365 while (st
->to_read
> 0) {
366 st
->chunk
= st
->to_read
;
367 while ((*datalen
) == 0)
368 crReturn(st
->to_read
);
369 if (st
->chunk
> (*datalen
))
370 st
->chunk
= (*datalen
);
371 memcpy(st
->p
, *data
, st
->chunk
);
373 *datalen
-= st
->chunk
;
375 st
->to_read
-= st
->chunk
;
379 cipher
->decrypt(pktin
.data
, st
->biglen
);
381 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
382 for (st
->i
= 0; st
->i
< st
->biglen
; st
->i
++)
383 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
387 st
->realcrc
= crc32(pktin
.data
, st
->biglen
-4);
388 st
->gotcrc
= GET_32BIT(pktin
.data
+st
->biglen
-4);
389 if (st
->gotcrc
!= st
->realcrc
) {
390 bombout(("Incorrect CRC received on packet"));
394 pktin
.body
= pktin
.data
+ st
->pad
+ 1;
396 if (ssh1_compressing
) {
397 unsigned char *decompblk
;
401 debug(("Packet payload pre-decompression:\n"));
402 for (i
= -1; i
< pktin
.length
; i
++)
403 debug((" %02x", (unsigned char)pktin
.body
[i
]));
406 zlib_decompress_block(pktin
.body
-1, pktin
.length
+1,
407 &decompblk
, &decomplen
);
409 if (pktin
.maxlen
< st
->pad
+ decomplen
) {
410 pktin
.maxlen
= st
->pad
+ decomplen
;
411 pktin
.data
= realloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
);
413 fatalbox("Out of memory");
416 memcpy(pktin
.body
-1, decompblk
, decomplen
);
418 pktin
.length
= decomplen
-1;
420 debug(("Packet payload post-decompression:\n"));
421 for (i
= -1; i
< pktin
.length
; i
++)
422 debug((" %02x", (unsigned char)pktin
.body
[i
]));
427 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
428 pktin
.type
== SSH1_SMSG_STDERR_DATA
||
429 pktin
.type
== SSH1_MSG_DEBUG
||
430 pktin
.type
== SSH1_SMSG_AUTH_TIS_CHALLENGE
||
431 pktin
.type
== SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
432 long strlen
= GET_32BIT(pktin
.body
);
433 if (strlen
+ 4 != pktin
.length
) {
434 bombout(("Received data packet with bogus string length"));
439 pktin
.type
= pktin
.body
[-1];
441 if (pktin
.type
== SSH1_MSG_DEBUG
) {
442 /* log debug message */
444 int strlen
= GET_32BIT(pktin
.body
);
445 strcpy(buf
, "Remote: ");
446 if (strlen
> 70) strlen
= 70;
447 memcpy(buf
+8, pktin
.body
+4, strlen
);
448 buf
[8+strlen
] = '\0';
451 } else if (pktin
.type
== SSH1_MSG_IGNORE
) {
459 static int ssh2_rdpkt(unsigned char **data
, int *datalen
)
461 struct rdpkt2_state_tag
*st
= &rdpkt2_state
;
469 st
->cipherblk
= sccipher
->blksize
;
472 if (st
->cipherblk
< 8)
475 if (pktin
.maxlen
< st
->cipherblk
) {
476 pktin
.maxlen
= st
->cipherblk
;
477 pktin
.data
= (pktin
.data
== NULL ?
malloc(st
->cipherblk
+APIEXTRA
) :
478 realloc(pktin
.data
, st
->cipherblk
+APIEXTRA
));
480 fatalbox("Out of memory");
484 * Acquire and decrypt the first block of the packet. This will
485 * contain the length and padding details.
487 for (st
->i
= st
->len
= 0; st
->i
< st
->cipherblk
; st
->i
++) {
488 while ((*datalen
) == 0)
489 crReturn(st
->cipherblk
-st
->i
);
490 pktin
.data
[st
->i
] = *(*data
)++;
494 if (!memcmp(pktin
.data
, "Remo", 4)) {/* "Remo"te server has closed ... */
499 sccipher
->decrypt(pktin
.data
, st
->cipherblk
);
502 * Now get the length and padding figures.
504 st
->len
= GET_32BIT(pktin
.data
);
505 st
->pad
= pktin
.data
[4];
508 * This enables us to deduce the payload length.
510 st
->payload
= st
->len
- st
->pad
- 1;
512 pktin
.length
= st
->payload
+ 5;
515 * So now we can work out the total packet length.
517 st
->packetlen
= st
->len
+ 4;
518 st
->maclen
= scmac ? scmac
->len
: 0;
521 * Adjust memory allocation if packet is too big.
523 if (pktin
.maxlen
< st
->packetlen
+st
->maclen
) {
524 pktin
.maxlen
= st
->packetlen
+st
->maclen
;
525 pktin
.data
= (pktin
.data
== NULL ?
malloc(pktin
.maxlen
+APIEXTRA
) :
526 realloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
528 fatalbox("Out of memory");
532 * Read and decrypt the remainder of the packet.
534 for (st
->i
= st
->cipherblk
; st
->i
< st
->packetlen
+ st
->maclen
; st
->i
++) {
535 while ((*datalen
) == 0)
536 crReturn(st
->packetlen
+ st
->maclen
- st
->i
);
537 pktin
.data
[st
->i
] = *(*data
)++;
540 /* Decrypt everything _except_ the MAC. */
542 sccipher
->decrypt(pktin
.data
+ st
->cipherblk
,
543 st
->packetlen
- st
->cipherblk
);
546 debug(("Got packet len=%d pad=%d\r\n", st
->len
, st
->pad
));
547 for (st
->i
= 0; st
->i
< st
->packetlen
; st
->i
++)
548 debug((" %02x", (unsigned char)pktin
.data
[st
->i
]));
555 if (scmac
&& !scmac
->verify(pktin
.data
, st
->len
+4, st
->incoming_sequence
)) {
556 bombout(("Incorrect MAC received on packet"));
559 st
->incoming_sequence
++; /* whether or not we MACed */
562 * Decompress packet payload.
565 unsigned char *newpayload
;
567 if (sccomp
&& sccomp
->decompress(pktin
.data
+5, pktin
.length
-5,
568 &newpayload
, &newlen
)) {
569 if (pktin
.maxlen
< newlen
+5) {
570 pktin
.maxlen
= newlen
+5;
571 pktin
.data
= (pktin
.data
== NULL ?
malloc(pktin
.maxlen
+APIEXTRA
) :
572 realloc(pktin
.data
, pktin
.maxlen
+APIEXTRA
));
574 fatalbox("Out of memory");
576 pktin
.length
= 5 + newlen
;
577 memcpy(pktin
.data
+5, newpayload
, newlen
);
579 debug(("Post-decompression payload:\r\n"));
580 for (st
->i
= 0; st
->i
< newlen
; st
->i
++)
581 debug((" %02x", (unsigned char)pktin
.data
[5+st
->i
]));
590 pktin
.type
= pktin
.data
[5];
592 if (pktin
.type
== SSH2_MSG_IGNORE
|| pktin
.type
== SSH2_MSG_DEBUG
)
593 goto next_packet
; /* FIXME: print DEBUG message */
598 static void ssh1_pktout_size(int len
) {
601 len
+= 5; /* type and CRC */
605 pktout
.length
= len
-5;
606 if (pktout
.maxlen
< biglen
) {
607 pktout
.maxlen
= biglen
;
609 /* Allocate enough buffer space for extra block
610 * for MS CryptEncrypt() */
611 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+12) :
612 realloc(pktout
.data
, biglen
+12));
614 pktout
.data
= (pktout
.data
== NULL ?
malloc(biglen
+4) :
615 realloc(pktout
.data
, biglen
+4));
618 fatalbox("Out of memory");
620 pktout
.body
= pktout
.data
+4+pad
+1;
623 static void s_wrpkt_start(int type
, int len
) {
624 ssh1_pktout_size(len
);
628 static void s_wrpkt(void) {
629 int pad
, len
, biglen
, i
;
632 pktout
.body
[-1] = pktout
.type
;
634 if (ssh1_compressing
) {
635 unsigned char *compblk
;
638 debug(("Packet payload pre-compression:\n"));
639 for (i
= -1; i
< pktout
.length
; i
++)
640 debug((" %02x", (unsigned char)pktout
.body
[i
]));
643 zlib_compress_block(pktout
.body
-1, pktout
.length
+1,
645 ssh1_pktout_size(complen
-1);
646 memcpy(pktout
.body
-1, compblk
, complen
);
649 debug(("Packet payload post-compression:\n"));
650 for (i
= -1; i
< pktout
.length
; i
++)
651 debug((" %02x", (unsigned char)pktout
.body
[i
]));
656 len
= pktout
.length
+ 5; /* type and CRC */
660 for (i
=0; i
<pad
; i
++)
661 pktout
.data
[i
+4] = random_byte();
662 crc
= crc32(pktout
.data
+4, biglen
-4);
663 PUT_32BIT(pktout
.data
+biglen
, crc
);
664 PUT_32BIT(pktout
.data
, len
);
667 debug(("Sending packet len=%d\r\n", biglen
+4));
668 for (i
= 0; i
< biglen
+4; i
++)
669 debug((" %02x", (unsigned char)pktout
.data
[i
]));
673 cipher
->encrypt(pktout
.data
+4, biglen
);
675 sk_write(s
, pktout
.data
, biglen
+4);
679 * Construct a packet with the specified contents and
680 * send it to the server.
682 static void send_packet(int pkttype
, ...)
685 unsigned char *p
, *argp
, argchar
;
686 unsigned long argint
;
687 int pktlen
, argtype
, arglen
;
691 va_start(args
, pkttype
);
692 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
695 (void) va_arg(args
, int);
699 (void) va_arg(args
, char);
703 (void) va_arg(args
, unsigned char *);
704 arglen
= va_arg(args
, int);
708 argp
= va_arg(args
, unsigned char *);
709 arglen
= strlen(argp
);
710 pktlen
+= 4 + arglen
;
713 bn
= va_arg(args
, Bignum
);
714 pktlen
+= ssh1_bignum_length(bn
);
722 s_wrpkt_start(pkttype
, pktlen
);
725 va_start(args
, pkttype
);
726 while ((argtype
= va_arg(args
, int)) != PKT_END
) {
729 argint
= va_arg(args
, int);
730 PUT_32BIT(p
, argint
);
734 argchar
= va_arg(args
, unsigned char);
739 argp
= va_arg(args
, unsigned char *);
740 arglen
= va_arg(args
, int);
741 memcpy(p
, argp
, arglen
);
745 argp
= va_arg(args
, unsigned char *);
746 arglen
= strlen(argp
);
747 PUT_32BIT(p
, arglen
);
748 memcpy(p
+ 4, argp
, arglen
);
752 bn
= va_arg(args
, Bignum
);
753 p
+= ssh1_write_bignum(p
, bn
);
762 static int ssh_versioncmp(char *a
, char *b
) {
764 unsigned long av
, bv
;
766 av
= strtoul(a
, &ae
, 10);
767 bv
= strtoul(b
, &be
, 10);
768 if (av
!= bv
) return (av
< bv ?
-1 : +1);
769 if (*ae
== '.') ae
++;
770 if (*be
== '.') be
++;
771 av
= strtoul(ae
, &ae
, 10);
772 bv
= strtoul(be
, &be
, 10);
773 if (av
!= bv
) return (av
< bv ?
-1 : +1);
779 * Utility routine for putting an SSH-protocol `string' into a SHA
783 static void sha_string(SHA_State
*s
, void *str
, int len
) {
784 unsigned char lenblk
[4];
785 PUT_32BIT(lenblk
, len
);
786 SHA_Bytes(s
, lenblk
, 4);
787 SHA_Bytes(s
, str
, len
);
791 * SSH2 packet construction functions.
793 static void ssh2_pkt_adddata(void *data
, int len
) {
794 pktout
.length
+= len
;
795 if (pktout
.maxlen
< pktout
.length
) {
796 pktout
.maxlen
= pktout
.length
+ 256;
797 pktout
.data
= (pktout
.data
== NULL ?
malloc(pktout
.maxlen
+APIEXTRA
) :
798 realloc(pktout
.data
, pktout
.maxlen
+APIEXTRA
));
800 fatalbox("Out of memory");
802 memcpy(pktout
.data
+pktout
.length
-len
, data
, len
);
804 static void ssh2_pkt_addbyte(unsigned char byte
) {
805 ssh2_pkt_adddata(&byte
, 1);
807 static void ssh2_pkt_init(int pkt_type
) {
809 ssh2_pkt_addbyte((unsigned char)pkt_type
);
811 static void ssh2_pkt_addbool(unsigned char value
) {
812 ssh2_pkt_adddata(&value
, 1);
814 static void ssh2_pkt_adduint32(unsigned long value
) {
817 ssh2_pkt_adddata(x
, 4);
819 static void ssh2_pkt_addstring_start(void) {
820 ssh2_pkt_adduint32(0);
821 pktout
.savedpos
= pktout
.length
;
823 static void ssh2_pkt_addstring_str(char *data
) {
824 ssh2_pkt_adddata(data
, strlen(data
));
825 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
826 pktout
.length
- pktout
.savedpos
);
828 static void ssh2_pkt_addstring_data(char *data
, int len
) {
829 ssh2_pkt_adddata(data
, len
);
830 PUT_32BIT(pktout
.data
+ pktout
.savedpos
- 4,
831 pktout
.length
- pktout
.savedpos
);
833 static void ssh2_pkt_addstring(char *data
) {
834 ssh2_pkt_addstring_start();
835 ssh2_pkt_addstring_str(data
);
837 static char *ssh2_mpint_fmt(Bignum b
, int *len
) {
840 p
= malloc(n
* 2 + 1);
842 fatalbox("out of memory");
844 for (i
= 0; i
< n
; i
++) {
845 p
[i
*2+1] = (b
[n
-i
] >> 8) & 0xFF;
846 p
[i
*2+2] = (b
[n
-i
] ) & 0xFF;
849 while (p
[i
] == 0 && (p
[i
+1] & 0x80) == 0)
851 memmove(p
, p
+i
, n
*2+1-i
);
855 static void ssh2_pkt_addmp(Bignum b
) {
858 p
= ssh2_mpint_fmt(b
, &len
);
859 ssh2_pkt_addstring_start();
860 ssh2_pkt_addstring_data(p
, len
);
863 static void ssh2_pkt_send(void) {
864 int cipherblk
, maclen
, padding
, i
;
865 static unsigned long outgoing_sequence
= 0;
868 * Compress packet payload.
871 debug(("Pre-compression payload:\r\n"));
872 for (i
= 5; i
< pktout
.length
; i
++)
873 debug((" %02x", (unsigned char)pktout
.data
[i
]));
877 unsigned char *newpayload
;
879 if (cscomp
&& cscomp
->compress(pktout
.data
+5, pktout
.length
-5,
880 &newpayload
, &newlen
)) {
882 ssh2_pkt_adddata(newpayload
, newlen
);
888 * Add padding. At least four bytes, and must also bring total
889 * length (minus MAC) up to a multiple of the block size.
891 cipherblk
= cipher ? cipher
->blksize
: 8; /* block size */
892 cipherblk
= cipherblk
< 8 ?
8 : cipherblk
; /* or 8 if blksize < 8 */
894 padding
+= (cipherblk
- (pktout
.length
+ padding
) % cipherblk
) % cipherblk
;
895 pktout
.data
[4] = padding
;
896 for (i
= 0; i
< padding
; i
++)
897 pktout
.data
[pktout
.length
+ i
] = random_byte();
898 PUT_32BIT(pktout
.data
, pktout
.length
+ padding
- 4);
900 csmac
->generate(pktout
.data
, pktout
.length
+ padding
,
902 outgoing_sequence
++; /* whether or not we MACed */
905 debug(("Sending packet len=%d\r\n", pktout
.length
+padding
));
906 for (i
= 0; i
< pktout
.length
+padding
; i
++)
907 debug((" %02x", (unsigned char)pktout
.data
[i
]));
912 cscipher
->encrypt(pktout
.data
, pktout
.length
+ padding
);
913 maclen
= csmac ? csmac
->len
: 0;
915 sk_write(s
, pktout
.data
, pktout
.length
+ padding
+ maclen
);
919 void bndebug(char *string
, Bignum b
) {
922 p
= ssh2_mpint_fmt(b
, &len
);
923 debug(("%s", string
));
924 for (i
= 0; i
< len
; i
++)
925 debug((" %02x", p
[i
]));
931 static void sha_mpint(SHA_State
*s
, Bignum b
) {
934 p
= ssh2_mpint_fmt(b
, &len
);
935 sha_string(s
, p
, len
);
940 * SSH2 packet decode functions.
942 static unsigned long ssh2_pkt_getuint32(void) {
944 if (pktin
.length
- pktin
.savedpos
< 4)
945 return 0; /* arrgh, no way to decline (FIXME?) */
946 value
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
950 static void ssh2_pkt_getstring(char **p
, int *length
) {
952 if (pktin
.length
- pktin
.savedpos
< 4)
954 *length
= GET_32BIT(pktin
.data
+pktin
.savedpos
);
956 if (pktin
.length
- pktin
.savedpos
< *length
)
958 *p
= pktin
.data
+pktin
.savedpos
;
959 pktin
.savedpos
+= *length
;
961 static Bignum
ssh2_pkt_getmp(void) {
966 ssh2_pkt_getstring(&p
, &length
);
970 bombout(("internal error: Can't handle negative mpints"));
973 b
= newbn((length
+1)/2);
974 for (i
= 0; i
< length
; i
++) {
977 b
[j
/2+1] |= ((unsigned char)p
[i
]) << 8;
979 b
[j
/2+1] |= ((unsigned char)p
[i
]);
981 while (b
[0] > 1 && b
[b
[0]] == 0) b
[0]--;
985 static int do_ssh_init(unsigned char c
) {
987 static char version
[10];
988 static char vstring
[80];
989 static char vlog
[sizeof(vstring
)+20];
994 /* Search for the string "SSH-" in the input. */
997 static const int transS
[] = { 1, 2, 2, 1 };
998 static const int transH
[] = { 0, 0, 3, 0 };
999 static const int transminus
[] = { 0, 0, 0, -1 };
1000 if (c
== 'S') i
= transS
[i
];
1001 else if (c
== 'H') i
= transH
[i
];
1002 else if (c
== '-') i
= transminus
[i
];
1006 crReturn(1); /* get another character */
1009 strcpy(vstring
, "SSH-");
1013 crReturn(1); /* get another char */
1014 if (vsp
< vstring
+sizeof(vstring
)-1)
1020 } else if (i
< sizeof(version
)-1)
1027 rdpkt2_state
.incoming_sequence
= 0;
1030 sprintf(vlog
, "Server version: %s", vstring
);
1031 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1035 * Server version "1.99" means we can choose whether we use v1
1036 * or v2 protocol. Choice is based on cfg.sshprot.
1038 if (ssh_versioncmp(version
, cfg
.sshprot
== 1 ?
"2.0" : "1.99") >= 0) {
1040 * This is a v2 server. Begin v2 protocol.
1042 char *verstring
= "SSH-2.0-PuTTY";
1045 * Hash our version string and their version string.
1047 sha_string(&exhash
, verstring
, strlen(verstring
));
1048 sha_string(&exhash
, vstring
, strcspn(vstring
, "\r\n"));
1049 sprintf(vstring
, "%s\n", verstring
);
1050 sprintf(vlog
, "We claim version: %s", verstring
);
1052 logevent("Using SSH protocol version 2");
1053 sk_write(s
, vstring
, strlen(vstring
));
1054 ssh_protocol
= ssh2_protocol
;
1056 s_rdpkt
= ssh2_rdpkt
;
1059 * This is a v1 server. Begin v1 protocol.
1061 sprintf(vstring
, "SSH-%s-PuTTY\n",
1062 (ssh_versioncmp(version
, "1.5") <= 0 ? version
: "1.5"));
1063 sprintf(vlog
, "We claim version: %s", vstring
);
1064 vlog
[strcspn(vlog
, "\r\n")] = '\0';
1066 logevent("Using SSH protocol version 1");
1067 sk_write(s
, vstring
, strlen(vstring
));
1068 ssh_protocol
= ssh1_protocol
;
1070 s_rdpkt
= ssh1_rdpkt
;
1076 static void ssh_gotdata(unsigned char *data
, int datalen
)
1081 * To begin with, feed the characters one by one to the
1082 * protocol initialisation / selection function do_ssh_init().
1083 * When that returns 0, we're done with the initial greeting
1084 * exchange and can move on to packet discipline.
1089 crReturnV
; /* more data please */
1090 ret
= do_ssh_init(*data
);
1097 * We emerge from that loop when the initial negotiation is
1098 * over and we have selected an s_rdpkt function. Now pass
1099 * everything to s_rdpkt, and then pass the resulting packets
1100 * to the proper protocol handler.
1105 while (datalen
> 0) {
1106 if ( s_rdpkt(&data
, &datalen
) == 0 ) {
1107 ssh_protocol(NULL
, 0, 1);
1108 if (ssh_state
== SSH_STATE_CLOSED
) {
1118 static int ssh_receive(Socket skt
, int urgent
, char *data
, int len
) {
1120 /* Connection has closed. */
1125 ssh_gotdata (data
, len
);
1126 if (ssh_state
== SSH_STATE_CLOSED
) {
1137 * Connect to specified host and port.
1138 * Returns an error message, or NULL on success.
1139 * Also places the canonical host name into `realhost'.
1141 static char *connect_to_host(char *host
, int port
, char **realhost
)
1150 savedhost
= malloc(1+strlen(host
));
1152 fatalbox("Out of memory");
1153 strcpy(savedhost
, host
);
1156 port
= 22; /* default ssh port */
1169 addr
= sk_namelookup(host
, realhost
);
1170 if ( (err
= sk_addr_error(addr
)) )
1180 s
= sk_new(addr
, port
, ssh_receive
);
1181 if ( (err
= sk_socket_error(s
)) )
1185 sk_write(s
, "connect ", 8);
1186 sk_write(s
, FWhost
, strlen(FWhost
));
1189 sprintf(buf
, " %d\n", FWport
);
1190 sk_write(s
, buf
, strlen(buf
));
1198 * Handle the key exchange and user authentication phases.
1200 static int do_ssh1_login(unsigned char *in
, int inlen
, int ispkt
)
1203 unsigned char *rsabuf
, *keystr1
, *keystr2
;
1204 unsigned char cookie
[8];
1205 struct RSAKey servkey
, hostkey
;
1206 struct MD5Context md5c
;
1207 static unsigned long supported_ciphers_mask
, supported_auths_mask
;
1208 static int tried_publickey
;
1209 static unsigned char session_id
[16];
1211 static char username
[100];
1215 if (!ispkt
) crWaitUntil(ispkt
);
1217 if (pktin
.type
!= SSH1_SMSG_PUBLIC_KEY
) {
1218 bombout(("Public key packet not received"));
1222 logevent("Received public keys");
1224 memcpy(cookie
, pktin
.body
, 8);
1226 i
= makekey(pktin
.body
+8, &servkey
, &keystr1
, 0);
1227 j
= makekey(pktin
.body
+8+i
, &hostkey
, &keystr2
, 0);
1230 * Log the host key fingerprint.
1234 logevent("Host key fingerprint is:");
1235 strcpy(logmsg
, " ");
1236 hostkey
.comment
= NULL
;
1237 rsa_fingerprint(logmsg
+strlen(logmsg
), sizeof(logmsg
)-strlen(logmsg
),
1242 supported_ciphers_mask
= GET_32BIT(pktin
.body
+12+i
+j
);
1243 supported_auths_mask
= GET_32BIT(pktin
.body
+16+i
+j
);
1246 MD5Update(&md5c
, keystr2
, hostkey
.bytes
);
1247 MD5Update(&md5c
, keystr1
, servkey
.bytes
);
1248 MD5Update(&md5c
, pktin
.body
, 8);
1249 MD5Final(session_id
, &md5c
);
1251 for (i
=0; i
<32; i
++)
1252 session_key
[i
] = random_byte();
1254 len
= (hostkey
.bytes
> servkey
.bytes ? hostkey
.bytes
: servkey
.bytes
);
1256 rsabuf
= malloc(len
);
1258 fatalbox("Out of memory");
1261 * Verify the host key.
1265 * First format the key into a string.
1267 int len
= rsastr_len(&hostkey
);
1268 char fingerprint
[100];
1269 char *keystr
= malloc(len
);
1271 fatalbox("Out of memory");
1272 rsastr_fmt(keystr
, &hostkey
);
1273 rsa_fingerprint(fingerprint
, sizeof(fingerprint
), &hostkey
);
1274 verify_ssh_host_key(savedhost
, savedport
, "rsa", keystr
, fingerprint
);
1278 for (i
=0; i
<32; i
++) {
1279 rsabuf
[i
] = session_key
[i
];
1281 rsabuf
[i
] ^= session_id
[i
];
1284 if (hostkey
.bytes
> servkey
.bytes
) {
1285 rsaencrypt(rsabuf
, 32, &servkey
);
1286 rsaencrypt(rsabuf
, servkey
.bytes
, &hostkey
);
1288 rsaencrypt(rsabuf
, 32, &hostkey
);
1289 rsaencrypt(rsabuf
, hostkey
.bytes
, &servkey
);
1292 logevent("Encrypted session key");
1294 cipher_type
= cfg
.cipher
== CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH
:
1295 cfg
.cipher
== CIPHER_DES ? SSH_CIPHER_DES
:
1297 if ((supported_ciphers_mask
& (1 << cipher_type
)) == 0) {
1298 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1299 cipher_type
= SSH_CIPHER_3DES
;
1301 switch (cipher_type
) {
1302 case SSH_CIPHER_3DES
: logevent("Using 3DES encryption"); break;
1303 case SSH_CIPHER_DES
: logevent("Using single-DES encryption"); break;
1304 case SSH_CIPHER_BLOWFISH
: logevent("Using Blowfish encryption"); break;
1307 send_packet(SSH1_CMSG_SESSION_KEY
,
1308 PKT_CHAR
, cipher_type
,
1309 PKT_DATA
, cookie
, 8,
1310 PKT_CHAR
, (len
*8) >> 8, PKT_CHAR
, (len
*8) & 0xFF,
1311 PKT_DATA
, rsabuf
, len
,
1315 logevent("Trying to enable encryption...");
1319 cipher
= cipher_type
== SSH_CIPHER_BLOWFISH ?
&ssh_blowfish_ssh1
:
1320 cipher_type
== SSH_CIPHER_DES ?
&ssh_des
:
1322 cipher
->sesskey(session_key
);
1326 if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1327 bombout(("Encryption not successfully enabled"));
1331 logevent("Successfully started encryption");
1337 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
1338 c_write("login as: ", 10);
1341 crWaitUntil(!ispkt
);
1342 while (inlen
--) switch (c
= *in
++) {
1349 c_write("\b \b", 3);
1355 c_write("\b \b", 3);
1364 if (((c
>= ' ' && c
<= '~') ||
1365 ((unsigned char)c
>= 160)) && pos
< 40) {
1366 username
[pos
++] = c
;
1373 username
[strcspn(username
, "\n\r")] = '\0';
1375 strncpy(username
, cfg
.username
, 99);
1376 username
[99] = '\0';
1379 send_packet(SSH1_CMSG_USER
, PKT_STR
, username
, PKT_END
);
1381 char userlog
[22+sizeof(username
)];
1382 sprintf(userlog
, "Sent username \"%s\"", username
);
1384 if (flags
& FLAG_INTERACTIVE
&&
1385 (!((flags
& FLAG_STDERR
) && (flags
& FLAG_VERBOSE
)))) {
1386 strcat(userlog
, "\r\n");
1387 c_write(userlog
, strlen(userlog
));
1394 tried_publickey
= 0;
1396 while (pktin
.type
== SSH1_SMSG_FAILURE
) {
1397 static char password
[100];
1398 static char prompt
[200];
1401 static int pwpkt_type
;
1403 * Show password prompt, having first obtained it via a TIS
1404 * or CryptoCard exchange if we're doing TIS or CryptoCard
1407 pwpkt_type
= SSH1_CMSG_AUTH_PASSWORD
;
1408 if (agent_exists()) {
1410 * Attempt RSA authentication using Pageant.
1412 static unsigned char request
[5], *response
, *p
;
1413 static int responselen
;
1414 static int i
, nkeys
;
1415 static int authed
= FALSE
;
1418 logevent("Pageant is running. Requesting keys.");
1420 /* Request the keys held by the agent. */
1421 PUT_32BIT(request
, 1);
1422 request
[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES
;
1423 agent_query(request
, 5, &r
, &responselen
);
1424 response
= (unsigned char *)r
;
1427 nkeys
= GET_32BIT(p
); p
+= 4;
1428 { char buf
[64]; sprintf(buf
, "Pageant has %d keys", nkeys
);
1430 for (i
= 0; i
< nkeys
; i
++) {
1431 static struct RSAKey key
;
1432 static Bignum challenge
;
1433 static char *commentp
;
1434 static int commentlen
;
1436 { char buf
[64]; sprintf(buf
, "Trying Pageant key #%d", i
);
1439 p
+= ssh1_read_bignum(p
, &key
.exponent
);
1440 p
+= ssh1_read_bignum(p
, &key
.modulus
);
1441 commentlen
= GET_32BIT(p
); p
+= 4;
1442 commentp
= p
; p
+= commentlen
;
1443 send_packet(SSH1_CMSG_AUTH_RSA
,
1444 PKT_BIGNUM
, key
.modulus
, PKT_END
);
1446 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1447 logevent("Key refused");
1450 logevent("Received RSA challenge");
1451 ssh1_read_bignum(pktin
.body
, &challenge
);
1453 char *agentreq
, *q
, *ret
;
1455 len
= 1 + 4; /* message type, bit count */
1456 len
+= ssh1_bignum_length(key
.exponent
);
1457 len
+= ssh1_bignum_length(key
.modulus
);
1458 len
+= ssh1_bignum_length(challenge
);
1459 len
+= 16; /* session id */
1460 len
+= 4; /* response format */
1461 agentreq
= malloc(4 + len
);
1462 PUT_32BIT(agentreq
, len
);
1464 *q
++ = SSH_AGENTC_RSA_CHALLENGE
;
1465 PUT_32BIT(q
, ssh1_bignum_bitcount(key
.modulus
));
1467 q
+= ssh1_write_bignum(q
, key
.exponent
);
1468 q
+= ssh1_write_bignum(q
, key
.modulus
);
1469 q
+= ssh1_write_bignum(q
, challenge
);
1470 memcpy(q
, session_id
, 16); q
+= 16;
1471 PUT_32BIT(q
, 1); /* response format */
1472 agent_query(agentreq
, len
+4, &ret
, &retlen
);
1475 if (ret
[4] == SSH_AGENT_RSA_RESPONSE
) {
1476 logevent("Sending Pageant's response");
1477 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1478 PKT_DATA
, ret
+5, 16, PKT_END
);
1481 if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1482 logevent("Pageant's response accepted");
1483 if (flags
& FLAG_VERBOSE
) {
1484 c_write("Authenticated using RSA key \"",
1486 c_write(commentp
, commentlen
);
1487 c_write("\" from agent\r\n", 14);
1491 logevent("Pageant's response not accepted");
1493 logevent("Pageant failed to answer challenge");
1497 logevent("No reply received from Pageant");
1500 freebn(key
.exponent
);
1501 freebn(key
.modulus
);
1510 if (*cfg
.keyfile
&& !tried_publickey
)
1511 pwpkt_type
= SSH1_CMSG_AUTH_RSA
;
1513 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1515 (supported_auths_mask
& (1<<SSH1_AUTH_TIS
))) {
1516 pwpkt_type
= SSH1_CMSG_AUTH_TIS_RESPONSE
;
1517 logevent("Requested TIS authentication");
1518 send_packet(SSH1_CMSG_AUTH_TIS
, PKT_END
);
1520 if (pktin
.type
!= SSH1_SMSG_AUTH_TIS_CHALLENGE
) {
1521 logevent("TIS authentication declined");
1522 if (flags
& FLAG_INTERACTIVE
)
1523 c_write("TIS authentication refused.\r\n", 29);
1525 int challengelen
= ((pktin
.body
[0] << 24) |
1526 (pktin
.body
[1] << 16) |
1527 (pktin
.body
[2] << 8) |
1529 logevent("Received TIS challenge");
1530 if (challengelen
> sizeof(prompt
)-1)
1531 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1532 memcpy(prompt
, pktin
.body
+4, challengelen
);
1533 prompt
[challengelen
] = '\0';
1536 if (pktin
.type
== SSH1_SMSG_FAILURE
&&
1538 (supported_auths_mask
& (1<<SSH1_AUTH_CCARD
))) {
1539 pwpkt_type
= SSH1_CMSG_AUTH_CCARD_RESPONSE
;
1540 logevent("Requested CryptoCard authentication");
1541 send_packet(SSH1_CMSG_AUTH_CCARD
, PKT_END
);
1543 if (pktin
.type
!= SSH1_SMSG_AUTH_CCARD_CHALLENGE
) {
1544 logevent("CryptoCard authentication declined");
1545 c_write("CryptoCard authentication refused.\r\n", 29);
1547 int challengelen
= ((pktin
.body
[0] << 24) |
1548 (pktin
.body
[1] << 16) |
1549 (pktin
.body
[2] << 8) |
1551 logevent("Received CryptoCard challenge");
1552 if (challengelen
> sizeof(prompt
)-1)
1553 challengelen
= sizeof(prompt
)-1; /* prevent overrun */
1554 memcpy(prompt
, pktin
.body
+4, challengelen
);
1555 strncpy(prompt
+ challengelen
, "\r\nResponse : ",
1556 sizeof(prompt
)-challengelen
);
1557 prompt
[sizeof(prompt
)-1] = '\0';
1560 if (pwpkt_type
== SSH1_CMSG_AUTH_PASSWORD
) {
1561 sprintf(prompt
, "%.90s@%.90s's password: ",
1562 username
, savedhost
);
1564 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1565 char *comment
= NULL
;
1566 if (flags
& FLAG_VERBOSE
)
1567 c_write("Trying public key authentication.\r\n", 35);
1568 if (!rsakey_encrypted(cfg
.keyfile
, &comment
)) {
1569 if (flags
& FLAG_VERBOSE
)
1570 c_write("No passphrase required.\r\n", 25);
1573 sprintf(prompt
, "Passphrase for key \"%.100s\": ", comment
);
1577 if (ssh_get_password
) {
1578 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
1580 * get_password failed to get a password (for
1581 * example because one was supplied on the command
1582 * line which has already failed to work).
1585 logevent("No more passwords to try");
1586 ssh_state
= SSH_STATE_CLOSED
;
1590 c_write(prompt
, strlen(prompt
));
1594 crWaitUntil(!ispkt
);
1595 while (inlen
--) switch (c
= *in
++) {
1612 if (((c
>= ' ' && c
<= '~') ||
1613 ((unsigned char)c
>= 160)) && pos
< sizeof(password
))
1614 password
[pos
++] = c
;
1622 if (pwpkt_type
== SSH1_CMSG_AUTH_RSA
) {
1624 * Try public key authentication with the specified
1627 static struct RSAKey pubkey
;
1628 static Bignum challenge
, response
;
1630 static unsigned char buffer
[32];
1632 tried_publickey
= 1;
1633 i
= loadrsakey(cfg
.keyfile
, &pubkey
, NULL
, password
);
1635 c_write("Couldn't load public key from ", 30);
1636 c_write(cfg
.keyfile
, strlen(cfg
.keyfile
));
1637 c_write(".\r\n", 3);
1638 continue; /* go and try password */
1641 c_write("Wrong passphrase.\r\n", 19);
1642 tried_publickey
= 0;
1643 continue; /* try again */
1647 * Send a public key attempt.
1649 send_packet(SSH1_CMSG_AUTH_RSA
,
1650 PKT_BIGNUM
, pubkey
.modulus
, PKT_END
);
1653 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1654 c_write("Server refused our public key.\r\n", 32);
1655 continue; /* go and try password */
1657 if (pktin
.type
!= SSH1_SMSG_AUTH_RSA_CHALLENGE
) {
1658 bombout(("Bizarre response to offer of public key"));
1661 ssh1_read_bignum(pktin
.body
, &challenge
);
1662 response
= rsadecrypt(challenge
, &pubkey
);
1663 freebn(pubkey
.private_exponent
); /* burn the evidence */
1665 for (i
= 0; i
< 32; i
+= 2) {
1666 buffer
[i
] = response
[16-i
/2] >> 8;
1667 buffer
[i
+1] = response
[16-i
/2] & 0xFF;
1671 MD5Update(&md5c
, buffer
, 32);
1672 MD5Update(&md5c
, session_id
, 16);
1673 MD5Final(buffer
, &md5c
);
1675 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE
,
1676 PKT_DATA
, buffer
, 16, PKT_END
);
1679 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1680 if (flags
& FLAG_VERBOSE
)
1681 c_write("Failed to authenticate with our public key.\r\n",
1683 continue; /* go and try password */
1684 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1685 bombout(("Bizarre response to RSA authentication response"));
1689 break; /* we're through! */
1691 send_packet(pwpkt_type
, PKT_STR
, password
, PKT_END
);
1693 logevent("Sent password");
1694 memset(password
, 0, strlen(password
));
1696 if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1697 if (flags
& FLAG_VERBOSE
)
1698 c_write("Access denied\r\n", 15);
1699 logevent("Authentication refused");
1700 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1701 logevent("Received disconnect request");
1702 ssh_state
= SSH_STATE_CLOSED
;
1704 } else if (pktin
.type
!= SSH1_SMSG_SUCCESS
) {
1705 bombout(("Strange packet received, type %d", pktin
.type
));
1710 logevent("Authentication successful");
1715 static void ssh1_protocol(unsigned char *in
, int inlen
, int ispkt
) {
1720 while (!do_ssh1_login(in
, inlen
, ispkt
)) {
1723 if (ssh_state
== SSH_STATE_CLOSED
)
1726 if (cfg
.agentfwd
&& agent_exists()) {
1727 logevent("Requesting agent forwarding");
1728 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING
, PKT_END
);
1729 do { crReturnV
; } while (!ispkt
);
1730 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1731 bombout(("Protocol confusion"));
1733 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1734 logevent("Agent forwarding refused");
1736 logevent("Agent forwarding enabled");
1740 send_packet(SSH1_CMSG_REQUEST_PTY
,
1741 PKT_STR
, cfg
.termtype
,
1742 PKT_INT
, rows
, PKT_INT
, cols
,
1743 PKT_INT
, 0, PKT_INT
, 0,
1746 ssh_state
= SSH_STATE_INTERMED
;
1747 do { crReturnV
; } while (!ispkt
);
1748 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1749 bombout(("Protocol confusion"));
1751 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1752 c_write("Server refused to allocate pty\r\n", 32);
1754 logevent("Allocated pty");
1757 if (cfg
.compression
) {
1758 send_packet(SSH1_CMSG_REQUEST_COMPRESSION
, PKT_INT
, 6, PKT_END
);
1759 do { crReturnV
; } while (!ispkt
);
1760 if (pktin
.type
!= SSH1_SMSG_SUCCESS
&& pktin
.type
!= SSH1_SMSG_FAILURE
) {
1761 bombout(("Protocol confusion"));
1763 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1764 c_write("Server refused to compress\r\n", 32);
1766 logevent("Started compression");
1767 ssh1_compressing
= TRUE
;
1768 zlib_compress_init();
1769 zlib_decompress_init();
1772 if (*cfg
.remote_cmd
)
1773 send_packet(SSH1_CMSG_EXEC_CMD
, PKT_STR
, cfg
.remote_cmd
, PKT_END
);
1775 send_packet(SSH1_CMSG_EXEC_SHELL
, PKT_END
);
1776 logevent("Started session");
1778 ssh_state
= SSH_STATE_SESSION
;
1783 ssh_channels
= newtree234(ssh_channelcmp
);
1788 if (pktin
.type
== SSH1_SMSG_STDOUT_DATA
||
1789 pktin
.type
== SSH1_SMSG_STDERR_DATA
) {
1790 long len
= GET_32BIT(pktin
.body
);
1791 from_backend(pktin
.type
== SSH1_SMSG_STDERR_DATA
,
1793 } else if (pktin
.type
== SSH1_MSG_DISCONNECT
) {
1794 ssh_state
= SSH_STATE_CLOSED
;
1795 logevent("Received disconnect request");
1797 } else if (pktin
.type
== SSH1_SMSG_AGENT_OPEN
) {
1798 /* Remote side is trying to open a channel to talk to our
1799 * agent. Give them back a local channel number. */
1801 struct ssh_channel
*c
;
1803 for (c
= first234(ssh_channels
, &e
); c
; c
= next234(&e
)) {
1805 break; /* found a free number */
1808 c
= malloc(sizeof(struct ssh_channel
));
1809 c
->remoteid
= GET_32BIT(pktin
.body
);
1812 c
->type
= SSH1_SMSG_AGENT_OPEN
; /* identify channel type */
1813 c
->u
.a
.lensofar
= 0;
1814 add234(ssh_channels
, c
);
1815 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION
,
1816 PKT_INT
, c
->remoteid
, PKT_INT
, c
->localid
,
1818 } else if (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE
||
1819 pktin
.type
== SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION
) {
1820 /* Remote side closes a channel. */
1821 unsigned i
= GET_32BIT(pktin
.body
);
1822 struct ssh_channel
*c
;
1823 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1826 closetype
= (pktin
.type
== SSH1_MSG_CHANNEL_CLOSE ?
1 : 2);
1827 send_packet(pktin
.type
, PKT_INT
, c
->remoteid
, PKT_END
);
1828 c
->closes
|= closetype
;
1829 if (c
->closes
== 3) {
1830 del234(ssh_channels
, c
);
1834 } else if (pktin
.type
== SSH1_MSG_CHANNEL_DATA
) {
1835 /* Data sent down one of our channels. */
1836 int i
= GET_32BIT(pktin
.body
);
1837 int len
= GET_32BIT(pktin
.body
+4);
1838 unsigned char *p
= pktin
.body
+8;
1839 struct ssh_channel
*c
;
1840 c
= find234(ssh_channels
, &i
, ssh_channelfind
);
1843 case SSH1_SMSG_AGENT_OPEN
:
1844 /* Data for an agent message. Buffer it. */
1846 if (c
->u
.a
.lensofar
< 4) {
1847 int l
= min(4 - c
->u
.a
.lensofar
, len
);
1848 memcpy(c
->u
.a
.msglen
+ c
->u
.a
.lensofar
, p
, l
);
1849 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1851 if (c
->u
.a
.lensofar
== 4) {
1852 c
->u
.a
.totallen
= 4 + GET_32BIT(c
->u
.a
.msglen
);
1853 c
->u
.a
.message
= malloc(c
->u
.a
.totallen
);
1854 memcpy(c
->u
.a
.message
, c
->u
.a
.msglen
, 4);
1856 if (c
->u
.a
.lensofar
>= 4 && len
> 0) {
1857 int l
= min(c
->u
.a
.totallen
- c
->u
.a
.lensofar
, len
);
1858 memcpy(c
->u
.a
.message
+ c
->u
.a
.lensofar
, p
, l
);
1859 p
+= l
; len
-= l
; c
->u
.a
.lensofar
+= l
;
1861 if (c
->u
.a
.lensofar
== c
->u
.a
.totallen
) {
1862 void *reply
, *sentreply
;
1864 agent_query(c
->u
.a
.message
, c
->u
.a
.totallen
,
1869 /* Fake SSH_AGENT_FAILURE. */
1870 sentreply
= "\0\0\0\1\5";
1873 send_packet(SSH1_MSG_CHANNEL_DATA
,
1874 PKT_INT
, c
->remoteid
,
1876 PKT_DATA
, sentreply
, replylen
,
1880 free(c
->u
.a
.message
);
1881 c
->u
.a
.lensofar
= 0;
1887 } else if (pktin
.type
== SSH1_SMSG_SUCCESS
) {
1888 /* may be from EXEC_SHELL on some servers */
1889 } else if (pktin
.type
== SSH1_SMSG_FAILURE
) {
1890 /* may be from EXEC_SHELL on some servers
1891 * if no pty is available or in other odd cases. Ignore */
1892 } else if (pktin
.type
== SSH1_SMSG_EXIT_STATUS
) {
1893 send_packet(SSH1_CMSG_EXIT_CONFIRMATION
, PKT_END
);
1895 bombout(("Strange packet received: type %d", pktin
.type
));
1900 int len
= min(inlen
, 512);
1901 send_packet(SSH1_CMSG_STDIN_DATA
,
1902 PKT_INT
, len
, PKT_DATA
, in
, len
, PKT_END
);
1913 * Utility routine for decoding comma-separated strings in KEXINIT.
1915 static int in_commasep_string(char *needle
, char *haystack
, int haylen
) {
1916 int needlen
= strlen(needle
);
1919 * Is it at the start of the string?
1921 if (haylen
>= needlen
&& /* haystack is long enough */
1922 !memcmp(needle
, haystack
, needlen
) && /* initial match */
1923 (haylen
== needlen
|| haystack
[needlen
] == ',')
1924 /* either , or EOS follows */
1928 * If not, search for the next comma and resume after that.
1929 * If no comma found, terminate.
1931 while (haylen
> 0 && *haystack
!= ',')
1932 haylen
--, haystack
++;
1935 haylen
--, haystack
++; /* skip over comma itself */
1940 * SSH2 key creation method.
1942 static void ssh2_mkkey(Bignum K
, char *H
, char chr
, char *keyspace
) {
1944 /* First 20 bytes. */
1947 SHA_Bytes(&s
, H
, 20);
1948 SHA_Bytes(&s
, &chr
, 1);
1949 SHA_Bytes(&s
, H
, 20);
1950 SHA_Final(&s
, keyspace
);
1951 /* Next 20 bytes. */
1954 SHA_Bytes(&s
, H
, 20);
1955 SHA_Bytes(&s
, keyspace
, 20);
1956 SHA_Final(&s
, keyspace
+20);
1960 * Handle the SSH2 transport layer.
1962 static int do_ssh2_transport(unsigned char *in
, int inlen
, int ispkt
)
1966 static Bignum e
, f
, K
;
1967 static const struct ssh_mac
**maclist
;
1969 static const struct ssh_cipher
*cscipher_tobe
= NULL
;
1970 static const struct ssh_cipher
*sccipher_tobe
= NULL
;
1971 static const struct ssh_mac
*csmac_tobe
= NULL
;
1972 static const struct ssh_mac
*scmac_tobe
= NULL
;
1973 static const struct ssh_compress
*cscomp_tobe
= NULL
;
1974 static const struct ssh_compress
*sccomp_tobe
= NULL
;
1975 static char *hostkeydata
, *sigdata
, *keystr
, *fingerprint
;
1976 static int hostkeylen
, siglen
;
1977 static unsigned char exchange_hash
[20];
1978 static unsigned char keyspace
[40];
1979 static const struct ssh_cipher
*preferred_cipher
;
1980 static const struct ssh_compress
*preferred_comp
;
1986 * Set up the preferred cipher and compression.
1988 if (cfg
.cipher
== CIPHER_BLOWFISH
) {
1989 preferred_cipher
= &ssh_blowfish_ssh2
;
1990 } else if (cfg
.cipher
== CIPHER_DES
) {
1991 logevent("Single DES not supported in SSH2; using 3DES");
1992 preferred_cipher
= &ssh_3des_ssh2
;
1993 } else if (cfg
.cipher
== CIPHER_3DES
) {
1994 preferred_cipher
= &ssh_3des_ssh2
;
1996 /* Shouldn't happen, but we do want to initialise to _something_. */
1997 preferred_cipher
= &ssh_3des_ssh2
;
1999 if (cfg
.compression
)
2000 preferred_comp
= &ssh_zlib
;
2002 preferred_comp
= &ssh_comp_none
;
2005 * Be prepared to work around the buggy MAC problem.
2008 maclist
= buggymacs
, nmacs
= lenof(buggymacs
);
2010 maclist
= macs
, nmacs
= lenof(macs
);
2014 * Construct and send our key exchange packet.
2016 ssh2_pkt_init(SSH2_MSG_KEXINIT
);
2017 for (i
= 0; i
< 16; i
++)
2018 ssh2_pkt_addbyte((unsigned char)random_byte());
2019 /* List key exchange algorithms. */
2020 ssh2_pkt_addstring_start();
2021 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2022 ssh2_pkt_addstring_str(kex_algs
[i
]->name
);
2023 if (i
< lenof(kex_algs
)-1)
2024 ssh2_pkt_addstring_str(",");
2026 /* List server host key algorithms. */
2027 ssh2_pkt_addstring_start();
2028 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2029 ssh2_pkt_addstring_str(hostkey_algs
[i
]->name
);
2030 if (i
< lenof(hostkey_algs
)-1)
2031 ssh2_pkt_addstring_str(",");
2033 /* List client->server encryption algorithms. */
2034 ssh2_pkt_addstring_start();
2035 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2036 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2037 ssh2_pkt_addstring_str(c
->name
);
2038 if (i
< lenof(ciphers
))
2039 ssh2_pkt_addstring_str(",");
2041 /* List server->client encryption algorithms. */
2042 ssh2_pkt_addstring_start();
2043 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2044 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2045 ssh2_pkt_addstring_str(c
->name
);
2046 if (i
< lenof(ciphers
))
2047 ssh2_pkt_addstring_str(",");
2049 /* List client->server MAC algorithms. */
2050 ssh2_pkt_addstring_start();
2051 for (i
= 0; i
< nmacs
; i
++) {
2052 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2054 ssh2_pkt_addstring_str(",");
2056 /* List server->client MAC algorithms. */
2057 ssh2_pkt_addstring_start();
2058 for (i
= 0; i
< nmacs
; i
++) {
2059 ssh2_pkt_addstring_str(maclist
[i
]->name
);
2061 ssh2_pkt_addstring_str(",");
2063 /* List client->server compression algorithms. */
2064 ssh2_pkt_addstring_start();
2065 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2066 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2067 ssh2_pkt_addstring_str(c
->name
);
2068 if (i
< lenof(compressions
))
2069 ssh2_pkt_addstring_str(",");
2071 /* List server->client compression algorithms. */
2072 ssh2_pkt_addstring_start();
2073 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2074 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2075 ssh2_pkt_addstring_str(c
->name
);
2076 if (i
< lenof(compressions
))
2077 ssh2_pkt_addstring_str(",");
2079 /* List client->server languages. Empty list. */
2080 ssh2_pkt_addstring_start();
2081 /* List server->client languages. Empty list. */
2082 ssh2_pkt_addstring_start();
2083 /* First KEX packet does _not_ follow, because we're not that brave. */
2084 ssh2_pkt_addbool(FALSE
);
2086 ssh2_pkt_adduint32(0);
2087 sha_string(&exhash
, pktout
.data
+5, pktout
.length
-5);
2090 if (!ispkt
) crWaitUntil(ispkt
);
2091 sha_string(&exhash
, pktin
.data
+5, pktin
.length
-5);
2094 * Now examine the other side's KEXINIT to see what we're up
2097 if (pktin
.type
!= SSH2_MSG_KEXINIT
) {
2098 bombout(("expected key exchange packet from server"));
2101 kex
= NULL
; hostkey
= NULL
; cscipher_tobe
= NULL
; sccipher_tobe
= NULL
;
2102 csmac_tobe
= NULL
; scmac_tobe
= NULL
; cscomp_tobe
= NULL
; sccomp_tobe
= NULL
;
2103 pktin
.savedpos
+= 16; /* skip garbage cookie */
2104 ssh2_pkt_getstring(&str
, &len
); /* key exchange algorithms */
2105 for (i
= 0; i
< lenof(kex_algs
); i
++) {
2106 if (in_commasep_string(kex_algs
[i
]->name
, str
, len
)) {
2111 ssh2_pkt_getstring(&str
, &len
); /* host key algorithms */
2112 for (i
= 0; i
< lenof(hostkey_algs
); i
++) {
2113 if (in_commasep_string(hostkey_algs
[i
]->name
, str
, len
)) {
2114 hostkey
= hostkey_algs
[i
];
2118 ssh2_pkt_getstring(&str
, &len
); /* client->server cipher */
2119 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2120 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2121 if (in_commasep_string(c
->name
, str
, len
)) {
2126 ssh2_pkt_getstring(&str
, &len
); /* server->client cipher */
2127 for (i
= 0; i
< lenof(ciphers
)+1; i
++) {
2128 const struct ssh_cipher
*c
= i
==0 ? preferred_cipher
: ciphers
[i
-1];
2129 if (in_commasep_string(c
->name
, str
, len
)) {
2134 ssh2_pkt_getstring(&str
, &len
); /* client->server mac */
2135 for (i
= 0; i
< nmacs
; i
++) {
2136 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2137 csmac_tobe
= maclist
[i
];
2141 ssh2_pkt_getstring(&str
, &len
); /* server->client mac */
2142 for (i
= 0; i
< nmacs
; i
++) {
2143 if (in_commasep_string(maclist
[i
]->name
, str
, len
)) {
2144 scmac_tobe
= maclist
[i
];
2148 ssh2_pkt_getstring(&str
, &len
); /* client->server compression */
2149 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2150 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2151 if (in_commasep_string(c
->name
, str
, len
)) {
2156 ssh2_pkt_getstring(&str
, &len
); /* server->client compression */
2157 for (i
= 0; i
< lenof(compressions
)+1; i
++) {
2158 const struct ssh_compress
*c
= i
==0 ? preferred_comp
: compressions
[i
-1];
2159 if (in_commasep_string(c
->name
, str
, len
)) {
2166 * Currently we only support Diffie-Hellman and DSS, so let's
2167 * bomb out if those aren't selected.
2169 if (kex
!= &ssh_diffiehellman
|| hostkey
!= &ssh_dss
) {
2170 bombout(("internal fault: chaos in SSH 2 transport layer"));
2175 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2178 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT
);
2183 if (pktin
.type
!= SSH2_MSG_KEXDH_REPLY
) {
2184 bombout(("expected key exchange packet from server"));
2187 ssh2_pkt_getstring(&hostkeydata
, &hostkeylen
);
2188 f
= ssh2_pkt_getmp();
2189 ssh2_pkt_getstring(&sigdata
, &siglen
);
2193 sha_string(&exhash
, hostkeydata
, hostkeylen
);
2194 sha_mpint(&exhash
, e
);
2195 sha_mpint(&exhash
, f
);
2196 sha_mpint(&exhash
, K
);
2197 SHA_Final(&exhash
, exchange_hash
);
2200 debug(("Exchange hash is:\r\n"));
2201 for (i
= 0; i
< 20; i
++)
2202 debug((" %02x", exchange_hash
[i
]));
2206 hostkey
->setkey(hostkeydata
, hostkeylen
);
2207 if (!hostkey
->verifysig(sigdata
, siglen
, exchange_hash
, 20)) {
2208 bombout(("Server failed host key check"));
2213 * Expect SSH2_MSG_NEWKEYS from server.
2216 if (pktin
.type
!= SSH2_MSG_NEWKEYS
) {
2217 bombout(("expected new-keys packet from server"));
2222 * Authenticate remote host: verify host key. (We've already
2223 * checked the signature of the exchange hash.)
2225 keystr
= hostkey
->fmtkey();
2226 fingerprint
= hostkey
->fingerprint();
2227 verify_ssh_host_key(savedhost
, savedport
, hostkey
->keytype
,
2228 keystr
, fingerprint
);
2229 logevent("Host key fingerprint is:");
2230 logevent(fingerprint
);
2235 * Send SSH2_MSG_NEWKEYS.
2237 ssh2_pkt_init(SSH2_MSG_NEWKEYS
);
2241 * Create and initialise session keys.
2243 cscipher
= cscipher_tobe
;
2244 sccipher
= sccipher_tobe
;
2247 cscomp
= cscomp_tobe
;
2248 sccomp
= sccomp_tobe
;
2249 cscomp
->compress_init();
2250 sccomp
->decompress_init();
2252 * Set IVs after keys.
2254 ssh2_mkkey(K
, exchange_hash
, 'C', keyspace
); cscipher
->setcskey(keyspace
);
2255 ssh2_mkkey(K
, exchange_hash
, 'D', keyspace
); cscipher
->setsckey(keyspace
);
2256 ssh2_mkkey(K
, exchange_hash
, 'A', keyspace
); cscipher
->setcsiv(keyspace
);
2257 ssh2_mkkey(K
, exchange_hash
, 'B', keyspace
); sccipher
->setsciv(keyspace
);
2258 ssh2_mkkey(K
, exchange_hash
, 'E', keyspace
); csmac
->setcskey(keyspace
);
2259 ssh2_mkkey(K
, exchange_hash
, 'F', keyspace
); scmac
->setsckey(keyspace
);
2262 * Now we're encrypting. Begin returning 1 to the protocol main
2263 * function so that other things can run on top of the
2264 * transport. If we ever see a KEXINIT, we must go back to the
2269 } while (!(ispkt
&& pktin
.type
== SSH2_MSG_KEXINIT
));
2270 goto begin_key_exchange
;
2276 * Handle the SSH2 userauth and connection layers.
2278 static void do_ssh2_authconn(unsigned char *in
, int inlen
, int ispkt
)
2280 static unsigned long remote_winsize
;
2281 static unsigned long remote_maxpkt
;
2286 * Request userauth protocol, and await a response to it.
2288 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST
);
2289 ssh2_pkt_addstring("ssh-userauth");
2291 crWaitUntilV(ispkt
);
2292 if (pktin
.type
!= SSH2_MSG_SERVICE_ACCEPT
) {
2293 bombout(("Server refused user authentication protocol"));
2298 * FIXME: currently we support only password authentication.
2299 * (This places us technically in violation of the SSH2 spec.
2300 * We must fix this.)
2304 * Get a username and a password.
2306 static char username
[100];
2307 static char password
[100];
2311 if ((flags
& FLAG_INTERACTIVE
) && !*cfg
.username
) {
2312 c_write("login as: ", 10);
2315 crWaitUntilV(!ispkt
);
2316 while (inlen
--) switch (c
= *in
++) {
2323 c_write("\b \b", 3);
2329 c_write("\b \b", 3);
2338 if (((c
>= ' ' && c
<= '~') ||
2339 ((unsigned char)c
>= 160)) && pos
< 40) {
2340 username
[pos
++] = c
;
2347 username
[strcspn(username
, "\n\r")] = '\0';
2350 strncpy(username
, cfg
.username
, 99);
2351 username
[99] = '\0';
2352 if ((flags
& FLAG_VERBOSE
) || (flags
& FLAG_INTERACTIVE
)) {
2353 sprintf(stuff
, "Using username \"%s\".\r\n", username
);
2354 c_write(stuff
, strlen(stuff
));
2358 if (ssh_get_password
) {
2360 sprintf(prompt
, "%.90s@%.90s's password: ", username
, savedhost
);
2361 if (!ssh_get_password(prompt
, password
, sizeof(password
))) {
2363 * get_password failed to get a password (for
2364 * example because one was supplied on the command
2365 * line which has already failed to work).
2368 logevent("No more passwords to try");
2369 ssh_state
= SSH_STATE_CLOSED
;
2373 c_write("password: ", 10);
2378 crWaitUntilV(!ispkt
);
2379 while (inlen
--) switch (c
= *in
++) {
2396 if (((c
>= ' ' && c
<= '~') ||
2397 ((unsigned char)c
>= 160)) && pos
< 40)
2398 password
[pos
++] = c
;
2405 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST
);
2406 ssh2_pkt_addstring(username
);
2407 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2408 ssh2_pkt_addstring("password");
2409 ssh2_pkt_addbool(FALSE
);
2410 ssh2_pkt_addstring(password
);
2413 crWaitUntilV(ispkt
);
2414 if (pktin
.type
!= SSH2_MSG_USERAUTH_SUCCESS
) {
2415 c_write("Access denied\r\n", 15);
2416 logevent("Authentication refused");
2422 * Now we're authenticated for the connection protocol. The
2423 * connection protocol will automatically have started at this
2424 * point; there's no need to send SERVICE_REQUEST.
2428 * So now create a channel with a session in it.
2430 mainchan
= malloc(sizeof(struct ssh_channel
));
2431 mainchan
->localid
= 100; /* as good as any */
2432 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN
);
2433 ssh2_pkt_addstring("session");
2434 ssh2_pkt_adduint32(mainchan
->localid
);
2435 ssh2_pkt_adduint32(0x8000UL
); /* our window size */
2436 ssh2_pkt_adduint32(0x4000UL
); /* our max pkt size */
2438 crWaitUntilV(ispkt
);
2439 if (pktin
.type
!= SSH2_MSG_CHANNEL_OPEN_CONFIRMATION
) {
2440 bombout(("Server refused to open a session"));
2442 /* FIXME: error data comes back in FAILURE packet */
2444 if (ssh2_pkt_getuint32() != mainchan
->localid
) {
2445 bombout(("Server's channel confirmation cited wrong channel"));
2448 mainchan
->remoteid
= ssh2_pkt_getuint32();
2449 mainchan
->u
.v2
.remwindow
= ssh2_pkt_getuint32();
2450 mainchan
->u
.v2
.remmaxpkt
= ssh2_pkt_getuint32();
2451 mainchan
->u
.v2
.outbuffer
= NULL
;
2452 mainchan
->u
.v2
.outbuflen
= mainchan
->u
.v2
.outbufsize
= 0;
2453 logevent("Opened channel for session");
2456 * Now allocate a pty for the session.
2459 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2460 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2461 ssh2_pkt_addstring("pty-req");
2462 ssh2_pkt_addbool(1); /* want reply */
2463 ssh2_pkt_addstring(cfg
.termtype
);
2464 ssh2_pkt_adduint32(cols
);
2465 ssh2_pkt_adduint32(rows
);
2466 ssh2_pkt_adduint32(0); /* pixel width */
2467 ssh2_pkt_adduint32(0); /* pixel height */
2468 ssh2_pkt_addstring_start();
2469 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2471 ssh_state
= SSH_STATE_INTERMED
;
2474 crWaitUntilV(ispkt
);
2475 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2476 /* FIXME: be able to handle other channels here */
2477 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2478 continue; /* wrong channel */
2479 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2481 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2483 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2484 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2485 bombout(("Server got confused by pty request"));
2488 c_write("Server refused to allocate pty\r\n", 32);
2490 logevent("Allocated pty");
2495 * Start a shell or a remote command.
2497 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2498 ssh2_pkt_adduint32(mainchan
->remoteid
); /* recipient channel */
2499 if (*cfg
.remote_cmd
) {
2500 ssh2_pkt_addstring("exec");
2501 ssh2_pkt_addbool(1); /* want reply */
2502 ssh2_pkt_addstring(cfg
.remote_cmd
);
2504 ssh2_pkt_addstring("shell");
2505 ssh2_pkt_addbool(1); /* want reply */
2509 crWaitUntilV(ispkt
);
2510 if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2511 /* FIXME: be able to handle other channels here */
2512 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2513 continue; /* wrong channel */
2514 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2516 } while (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2517 if (pktin
.type
!= SSH2_MSG_CHANNEL_SUCCESS
) {
2518 if (pktin
.type
!= SSH2_MSG_CHANNEL_FAILURE
) {
2519 bombout(("Server got confused by shell/command request"));
2522 bombout(("Server refused to start a shell/command"));
2525 logevent("Started a shell/command");
2528 ssh_state
= SSH_STATE_SESSION
;
2538 static int try_send
;
2542 if (pktin
.type
== SSH2_MSG_CHANNEL_DATA
||
2543 pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
) {
2546 /* FIXME: be able to handle other channels here */
2547 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2548 continue; /* wrong channel */
2549 if (pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
&&
2550 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR
)
2551 continue; /* extended but not stderr */
2552 ssh2_pkt_getstring(&data
, &length
);
2554 from_backend(pktin
.type
== SSH2_MSG_CHANNEL_EXTENDED_DATA
,
2557 * Enlarge the window again at the remote side,
2558 * just in case it ever runs down and they fail
2559 * to send us any more data.
2561 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST
);
2562 ssh2_pkt_adduint32(mainchan
->remoteid
);
2563 ssh2_pkt_adduint32(length
);
2566 } else if (pktin
.type
== SSH2_MSG_DISCONNECT
) {
2567 ssh_state
= SSH_STATE_CLOSED
;
2568 logevent("Received disconnect message");
2570 } else if (pktin
.type
== SSH2_MSG_CHANNEL_REQUEST
) {
2571 continue; /* exit status et al; ignore (FIXME?) */
2572 } else if (pktin
.type
== SSH2_MSG_CHANNEL_EOF
) {
2573 continue; /* remote sends EOF; ignore */
2574 } else if (pktin
.type
== SSH2_MSG_CHANNEL_CLOSE
) {
2575 /* FIXME: be able to handle other channels here */
2576 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2577 continue; /* wrong channel */
2578 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE
);
2579 ssh2_pkt_adduint32(mainchan
->remoteid
);
2581 /* FIXME: mark the channel as closed */
2582 if (1 /* FIXME: "all channels are closed" */) {
2583 logevent("All channels closed. Disconnecting");
2584 ssh2_pkt_init(SSH2_MSG_DISCONNECT
);
2585 ssh2_pkt_adduint32(SSH2_DISCONNECT_BY_APPLICATION
);
2586 ssh2_pkt_addstring("All open channels closed");
2587 ssh2_pkt_addstring("en"); /* language tag */
2589 ssh_state
= SSH_STATE_CLOSED
;
2592 continue; /* remote sends close; ignore (FIXME) */
2593 } else if (pktin
.type
== SSH2_MSG_CHANNEL_WINDOW_ADJUST
) {
2594 /* FIXME: be able to handle other channels here */
2595 if (ssh2_pkt_getuint32() != mainchan
->localid
)
2596 continue; /* wrong channel */
2597 mainchan
->u
.v2
.remwindow
+= ssh2_pkt_getuint32();
2600 bombout(("Strange packet received: type %d", pktin
.type
));
2605 * We have spare data. Add it to the channel buffer.
2607 if (mainchan
->u
.v2
.outbufsize
<
2608 mainchan
->u
.v2
.outbuflen
+ inlen
) {
2609 mainchan
->u
.v2
.outbufsize
=
2610 mainchan
->u
.v2
.outbuflen
+ inlen
+ 1024;
2611 mainchan
->u
.v2
.outbuffer
= srealloc(mainchan
->u
.v2
.outbuffer
,
2612 mainchan
->u
.v2
.outbufsize
);
2614 memcpy(mainchan
->u
.v2
.outbuffer
+ mainchan
->u
.v2
.outbuflen
,
2616 mainchan
->u
.v2
.outbuflen
+= inlen
;
2621 * Try to send data on the channel if we can. (FIXME:
2622 * on _all_ channels.)
2624 while (mainchan
->u
.v2
.remwindow
> 0 &&
2625 mainchan
->u
.v2
.outbuflen
> 0) {
2626 unsigned len
= mainchan
->u
.v2
.remwindow
;
2627 if (len
> mainchan
->u
.v2
.outbuflen
)
2628 len
= mainchan
->u
.v2
.outbuflen
;
2629 if (len
> mainchan
->u
.v2
.remmaxpkt
)
2630 len
= mainchan
->u
.v2
.remmaxpkt
;
2631 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA
);
2632 ssh2_pkt_adduint32(mainchan
->remoteid
);
2633 ssh2_pkt_addstring_start();
2634 ssh2_pkt_addstring_data(mainchan
->u
.v2
.outbuffer
, len
);
2636 mainchan
->u
.v2
.outbuflen
-= len
;
2637 memmove(mainchan
->u
.v2
.outbuffer
, mainchan
->u
.v2
.outbuffer
+len
,
2638 mainchan
->u
.v2
.outbuflen
);
2639 mainchan
->u
.v2
.remwindow
-= len
;
2648 * Handle the top-level SSH2 protocol.
2650 static void ssh2_protocol(unsigned char *in
, int inlen
, int ispkt
)
2652 if (do_ssh2_transport(in
, inlen
, ispkt
) == 0)
2654 do_ssh2_authconn(in
, inlen
, ispkt
);
2658 * Called to set up the connection.
2660 * Returns an error message, or NULL on success.
2662 static char *ssh_init (char *host
, int port
, char **realhost
) {
2666 if(crypto_startup() == 0)
2667 return "Microsoft high encryption pack not installed!";
2672 p
= connect_to_host(host
, port
, realhost
);
2680 * Called to send data down the Telnet connection.
2682 static void ssh_send (char *buf
, int len
) {
2686 ssh_protocol(buf
, len
, 0);
2690 * Called to set the size of the window from SSH's POV.
2692 static void ssh_size(void) {
2693 switch (ssh_state
) {
2694 case SSH_STATE_BEFORE_SIZE
:
2695 case SSH_STATE_CLOSED
:
2696 break; /* do nothing */
2697 case SSH_STATE_INTERMED
:
2698 size_needed
= TRUE
; /* buffer for later */
2700 case SSH_STATE_SESSION
:
2702 if (ssh_version
== 1) {
2703 send_packet(SSH1_CMSG_WINDOW_SIZE
,
2704 PKT_INT
, rows
, PKT_INT
, cols
,
2705 PKT_INT
, 0, PKT_INT
, 0, PKT_END
);
2707 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST
);
2708 ssh2_pkt_adduint32(mainchan
->remoteid
);
2709 ssh2_pkt_addstring("window-change");
2710 ssh2_pkt_addbool(0);
2711 ssh2_pkt_adduint32(cols
);
2712 ssh2_pkt_adduint32(rows
);
2713 ssh2_pkt_adduint32(0);
2714 ssh2_pkt_adduint32(0);
2722 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2723 * can send an EOF and collect resulting output (e.g. `plink
2726 static void ssh_special (Telnet_Special code
) {
2727 if (code
== TS_EOF
) {
2728 if (ssh_version
== 1) {
2729 send_packet(SSH1_CMSG_EOF
, PKT_END
);
2731 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF
);
2732 ssh2_pkt_adduint32(mainchan
->remoteid
);
2735 logevent("Sent EOF message");
2736 } else if (code
== TS_PING
) {
2737 if (ssh_version
== 1) {
2738 send_packet(SSH1_MSG_IGNORE
, PKT_STR
, "", PKT_END
);
2740 ssh2_pkt_init(SSH2_MSG_IGNORE
);
2741 ssh2_pkt_addstring_start();
2749 static Socket
ssh_socket(void) { return s
; }
2751 static int ssh_sendok(void) { return ssh_send_ok
; }
2753 Backend ssh_backend
= {