1 |
/* |
/* -*- c-basic-offset: 8 -*- |
2 |
rdesktop: A Remote Desktop Protocol client. |
rdesktop: A Remote Desktop Protocol client. |
3 |
Protocol services - RDP encryption and licensing |
Protocol services - RDP encryption and licensing |
4 |
Copyright (C) Matthew Chapman 1999-2001 |
Copyright (C) Matthew Chapman 1999-2002 |
5 |
|
|
6 |
This program is free software; you can redistribute it and/or modify |
This program is free software; you can redistribute it and/or modify |
7 |
it under the terms of the GNU General Public License as published by |
it under the terms of the GNU General Public License as published by |
25 |
#include <openssl/md5.h> |
#include <openssl/md5.h> |
26 |
#include <openssl/sha.h> |
#include <openssl/sha.h> |
27 |
#include <openssl/bn.h> |
#include <openssl/bn.h> |
28 |
|
#include <openssl/x509v3.h> |
29 |
#else |
#else |
30 |
#include "crypto/rc4.h" |
#include "crypto/rc4.h" |
31 |
#include "crypto/md5.h" |
#include "crypto/md5.h" |
37 |
extern int width; |
extern int width; |
38 |
extern int height; |
extern int height; |
39 |
extern int keylayout; |
extern int keylayout; |
40 |
extern BOOL encryption; |
extern BOOL g_encryption; |
41 |
extern BOOL licence_issued; |
extern BOOL g_licence_issued; |
42 |
|
extern BOOL g_use_rdp5; |
43 |
|
extern int g_server_bpp; |
44 |
|
extern uint16 mcs_userid; |
45 |
|
extern VCHANNEL g_channels[]; |
46 |
|
extern unsigned int g_num_channels; |
47 |
|
|
48 |
static int rc4_key_len; |
static int rc4_key_len; |
49 |
static RC4_KEY rc4_decrypt_key; |
static RC4_KEY rc4_decrypt_key; |
50 |
static RC4_KEY rc4_encrypt_key; |
static RC4_KEY rc4_encrypt_key; |
51 |
|
static RSA *server_public_key; |
52 |
|
|
53 |
static uint8 sec_sign_key[16]; |
static uint8 sec_sign_key[16]; |
54 |
static uint8 sec_decrypt_key[16]; |
static uint8 sec_decrypt_key[16]; |
57 |
static uint8 sec_encrypt_update_key[16]; |
static uint8 sec_encrypt_update_key[16]; |
58 |
static uint8 sec_crypted_random[SEC_MODULUS_SIZE]; |
static uint8 sec_crypted_random[SEC_MODULUS_SIZE]; |
59 |
|
|
60 |
|
uint16 g_server_rdp_version = 0; |
61 |
|
|
62 |
/* |
/* |
63 |
* General purpose 48-byte transformation, using two 32-byte salts (generally, |
* General purpose 48-byte transformation, using two 32-byte salts (generally, |
64 |
* a client and server salt) and a global salt value used for padding. |
* a client and server salt) and a global salt value used for padding. |
136 |
memcpy(sec_sign_key, session_key, 16); |
memcpy(sec_sign_key, session_key, 16); |
137 |
|
|
138 |
/* Generate RC4 keys */ |
/* Generate RC4 keys */ |
139 |
sec_hash_16(sec_decrypt_key, &session_key[16], client_key, |
sec_hash_16(sec_decrypt_key, &session_key[16], client_key, server_key); |
140 |
server_key); |
sec_hash_16(sec_encrypt_key, &session_key[32], client_key, server_key); |
|
sec_hash_16(sec_encrypt_key, &session_key[32], client_key, |
|
|
server_key); |
|
141 |
|
|
142 |
if (rc4_key_size == 1) |
if (rc4_key_size == 1) |
143 |
{ |
{ |
149 |
} |
} |
150 |
else |
else |
151 |
{ |
{ |
152 |
DEBUG(("128-bit encryption enabled\n")); |
DEBUG(("rc_4_key_size == %d, 128-bit encryption enabled\n", rc4_key_size)); |
153 |
rc4_key_len = 16; |
rc4_key_len = 16; |
154 |
} |
} |
155 |
|
|
188 |
|
|
189 |
/* Generate a signature hash, using a combination of SHA1 and MD5 */ |
/* Generate a signature hash, using a combination of SHA1 and MD5 */ |
190 |
void |
void |
191 |
sec_sign(uint8 * signature, int siglen, uint8 * session_key, int keylen, |
sec_sign(uint8 * signature, int siglen, uint8 * session_key, int keylen, uint8 * data, int datalen) |
|
uint8 * data, int datalen) |
|
192 |
{ |
{ |
193 |
uint8 shasig[20]; |
uint8 shasig[20]; |
194 |
uint8 md5sig[16]; |
uint8 md5sig[16]; |
260 |
} |
} |
261 |
|
|
262 |
/* Decrypt data using RC4 */ |
/* Decrypt data using RC4 */ |
263 |
static void |
void |
264 |
sec_decrypt(uint8 * data, int length) |
sec_decrypt(uint8 * data, int length) |
265 |
{ |
{ |
266 |
static int use_count; |
static int use_count; |
292 |
|
|
293 |
/* Perform an RSA public key encryption operation */ |
/* Perform an RSA public key encryption operation */ |
294 |
static void |
static void |
295 |
sec_rsa_encrypt(uint8 * out, uint8 * in, int len, |
sec_rsa_encrypt(uint8 * out, uint8 * in, int len, uint8 * modulus, uint8 * exponent) |
|
uint8 * modulus, uint8 * exponent) |
|
296 |
{ |
{ |
297 |
BN_CTX ctx; |
BN_CTX *ctx; |
298 |
BIGNUM mod, exp, x, y; |
BIGNUM mod, exp, x, y; |
299 |
uint8 inr[SEC_MODULUS_SIZE]; |
uint8 inr[SEC_MODULUS_SIZE]; |
300 |
int outlen; |
int outlen; |
304 |
memcpy(inr, in, len); |
memcpy(inr, in, len); |
305 |
reverse(inr, len); |
reverse(inr, len); |
306 |
|
|
307 |
BN_CTX_init(&ctx); |
ctx = BN_CTX_new(); |
308 |
BN_init(&mod); |
BN_init(&mod); |
309 |
BN_init(&exp); |
BN_init(&exp); |
310 |
BN_init(&x); |
BN_init(&x); |
313 |
BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod); |
BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod); |
314 |
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp); |
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp); |
315 |
BN_bin2bn(inr, len, &x); |
BN_bin2bn(inr, len, &x); |
316 |
BN_mod_exp(&y, &x, &exp, &mod, &ctx); |
BN_mod_exp(&y, &x, &exp, &mod, ctx); |
317 |
outlen = BN_bn2bin(&y, out); |
outlen = BN_bn2bin(&y, out); |
318 |
reverse(out, outlen); |
reverse(out, outlen); |
319 |
if (outlen < SEC_MODULUS_SIZE) |
if (outlen < SEC_MODULUS_SIZE) |
323 |
BN_clear_free(&x); |
BN_clear_free(&x); |
324 |
BN_free(&exp); |
BN_free(&exp); |
325 |
BN_free(&mod); |
BN_free(&mod); |
326 |
BN_CTX_free(&ctx); |
BN_CTX_free(ctx); |
327 |
} |
} |
328 |
|
|
329 |
/* Initialise secure transport packet */ |
/* Initialise secure transport packet */ |
333 |
int hdrlen; |
int hdrlen; |
334 |
STREAM s; |
STREAM s; |
335 |
|
|
336 |
if (!licence_issued) |
if (!g_licence_issued) |
337 |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 4; |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 4; |
338 |
else |
else |
339 |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 0; |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 0; |
343 |
return s; |
return s; |
344 |
} |
} |
345 |
|
|
346 |
/* Transmit secure transport packet */ |
/* Transmit secure transport packet over specified channel */ |
347 |
void |
void |
348 |
sec_send(STREAM s, uint32 flags) |
sec_send_to_channel(STREAM s, uint32 flags, uint16 channel) |
349 |
{ |
{ |
350 |
int datalen; |
int datalen; |
351 |
|
|
352 |
s_pop_layer(s, sec_hdr); |
s_pop_layer(s, sec_hdr); |
353 |
if (!licence_issued || (flags & SEC_ENCRYPT)) |
if (!g_licence_issued || (flags & SEC_ENCRYPT)) |
354 |
out_uint32_le(s, flags); |
out_uint32_le(s, flags); |
355 |
|
|
356 |
if (flags & SEC_ENCRYPT) |
if (flags & SEC_ENCRYPT) |
363 |
hexdump(s->p + 8, datalen); |
hexdump(s->p + 8, datalen); |
364 |
#endif |
#endif |
365 |
|
|
366 |
sec_sign(s->p, 8, sec_sign_key, rc4_key_len, s->p + 8, |
sec_sign(s->p, 8, sec_sign_key, rc4_key_len, s->p + 8, datalen); |
|
datalen); |
|
367 |
sec_encrypt(s->p + 8, datalen); |
sec_encrypt(s->p + 8, datalen); |
368 |
} |
} |
369 |
|
|
370 |
mcs_send(s); |
mcs_send_to_channel(s, channel); |
371 |
|
} |
372 |
|
|
373 |
|
/* Transmit secure transport packet */ |
374 |
|
|
375 |
|
void |
376 |
|
sec_send(STREAM s, uint32 flags) |
377 |
|
{ |
378 |
|
sec_send_to_channel(s, flags, MCS_GLOBAL_CHANNEL); |
379 |
} |
} |
380 |
|
|
381 |
|
|
382 |
/* Transfer the client random to the server */ |
/* Transfer the client random to the server */ |
383 |
static void |
static void |
384 |
sec_establish_key() |
sec_establish_key(void) |
385 |
{ |
{ |
386 |
uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE; |
uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE; |
387 |
uint32 flags = SEC_CLIENT_RANDOM; |
uint32 flags = SEC_CLIENT_RANDOM; |
402 |
sec_out_mcs_data(STREAM s) |
sec_out_mcs_data(STREAM s) |
403 |
{ |
{ |
404 |
int hostlen = 2 * strlen(hostname); |
int hostlen = 2 * strlen(hostname); |
405 |
|
int length = 158 + 76 + 12 + 4; |
406 |
|
unsigned int i; |
407 |
|
|
408 |
|
if (g_num_channels > 0) |
409 |
|
length += g_num_channels * 12 + 8; |
410 |
|
|
411 |
|
if (hostlen > 30) |
412 |
|
hostlen = 30; |
413 |
|
|
414 |
out_uint16_be(s, 5); /* unknown */ |
out_uint16_be(s, 5); /* unknown */ |
415 |
out_uint16_be(s, 0x14); |
out_uint16_be(s, 0x14); |
416 |
out_uint8(s, 0x7c); |
out_uint8(s, 0x7c); |
417 |
out_uint16_be(s, 1); |
out_uint16_be(s, 1); |
418 |
|
|
419 |
out_uint16_be(s, (158 | 0x8000)); /* remaining length */ |
out_uint16_be(s, (length | 0x8000)); /* remaining length */ |
420 |
|
|
421 |
out_uint16_be(s, 8); /* length? */ |
out_uint16_be(s, 8); /* length? */ |
422 |
out_uint16_be(s, 16); |
out_uint16_be(s, 16); |
425 |
out_uint8(s, 0); |
out_uint8(s, 0); |
426 |
|
|
427 |
out_uint32_le(s, 0x61637544); /* "Duca" ?! */ |
out_uint32_le(s, 0x61637544); /* "Duca" ?! */ |
428 |
out_uint16_be(s, (144 | 0x8000)); /* remaining length */ |
out_uint16_be(s, ((length - 14) | 0x8000)); /* remaining length */ |
429 |
|
|
430 |
/* Client information */ |
/* Client information */ |
431 |
out_uint16_le(s, SEC_TAG_CLI_INFO); |
out_uint16_le(s, SEC_TAG_CLI_INFO); |
432 |
out_uint16_le(s, 136); /* length */ |
out_uint16_le(s, 212); /* length */ |
433 |
out_uint16_le(s, 1); |
out_uint16_le(s, g_use_rdp5 ? 4 : 1); /* RDP version. 1 == RDP4, 4 == RDP5. */ |
434 |
out_uint16_le(s, 8); |
out_uint16_le(s, 8); |
435 |
out_uint16_le(s, width); |
out_uint16_le(s, width); |
436 |
out_uint16_le(s, height); |
out_uint16_le(s, height); |
437 |
out_uint16_le(s, 0xca01); |
out_uint16_le(s, 0xca01); |
438 |
out_uint16_le(s, 0xaa03); |
out_uint16_le(s, 0xaa03); |
439 |
out_uint32_le(s, keylayout); |
out_uint32_le(s, keylayout); |
440 |
out_uint32_le(s, 419); /* client build? we are 419 compatible :-) */ |
out_uint32_le(s, 2600); /* Client build. We are now 2600 compatible :-) */ |
441 |
|
|
442 |
/* Unicode name of client, padded to 32 bytes */ |
/* Unicode name of client, padded to 32 bytes */ |
443 |
rdp_out_unistr(s, hostname, hostlen); |
rdp_out_unistr(s, hostname, hostlen); |
448 |
out_uint32_le(s, 12); |
out_uint32_le(s, 12); |
449 |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
450 |
|
|
451 |
out_uint16(s, 0xca01); |
switch (g_server_bpp) |
452 |
out_uint16(s, 0); |
{ |
453 |
|
case 8: |
454 |
|
out_uint16_le(s, 0xca01); |
455 |
|
break; |
456 |
|
case 15: |
457 |
|
out_uint16_le(s, 0xca02); |
458 |
|
break; |
459 |
|
case 16: |
460 |
|
out_uint16_le(s, 0xca03); |
461 |
|
break; |
462 |
|
case 24: |
463 |
|
out_uint16_le(s, 0xca04); |
464 |
|
break; |
465 |
|
} |
466 |
|
out_uint16_le(s, 1); |
467 |
|
|
468 |
|
out_uint32(s, 0); |
469 |
|
out_uint8(s, g_server_bpp); |
470 |
|
out_uint16_le(s, 0x0700); |
471 |
|
out_uint8(s, 0); |
472 |
|
out_uint32_le(s, 1); |
473 |
|
out_uint8s(s, 64); /* End of client info */ |
474 |
|
|
475 |
|
out_uint16_le(s, SEC_TAG_CLI_4); |
476 |
|
out_uint16_le(s, 12); |
477 |
|
out_uint32_le(s, 9); |
478 |
|
out_uint32(s, 0); |
479 |
|
|
480 |
/* Client encryption settings */ |
/* Client encryption settings */ |
481 |
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
482 |
out_uint16(s, 8); /* length */ |
out_uint16_le(s, 12); /* length */ |
483 |
out_uint32_le(s, encryption ? 0x3 : 0); /* encryption supported, 128-bit supported */ |
out_uint32_le(s, g_encryption ? 0x3 : 0); /* encryption supported, 128-bit supported */ |
484 |
|
out_uint32(s, 0); /* Unknown */ |
485 |
|
|
486 |
|
DEBUG_RDP5(("g_num_channels is %d\n", g_num_channels)); |
487 |
|
if (g_num_channels > 0) |
488 |
|
{ |
489 |
|
out_uint16_le(s, SEC_TAG_CLI_CHANNELS); |
490 |
|
out_uint16_le(s, g_num_channels * 12 + 8); /* length */ |
491 |
|
out_uint32_le(s, g_num_channels); /* number of virtual channels */ |
492 |
|
for (i = 0; i < g_num_channels; i++) |
493 |
|
{ |
494 |
|
DEBUG_RDP5(("Requesting channel %s\n", g_channels[i].name)); |
495 |
|
out_uint8a(s, g_channels[i].name, 8); |
496 |
|
out_uint32_be(s, g_channels[i].flags); |
497 |
|
} |
498 |
|
} |
499 |
|
|
500 |
s_mark_end(s); |
s_mark_end(s); |
501 |
} |
} |
502 |
|
|
528 |
return s_check(s); |
return s_check(s); |
529 |
} |
} |
530 |
|
|
531 |
|
static BOOL |
532 |
|
sec_parse_x509_key(X509 * cert) |
533 |
|
{ |
534 |
|
EVP_PKEY *epk = NULL; |
535 |
|
/* By some reason, Microsoft sets the OID of the Public RSA key to |
536 |
|
the oid for "MD5 with RSA Encryption" instead of "RSA Encryption" |
537 |
|
|
538 |
|
Kudos to Richard Levitte for the following (. intiutive .) |
539 |
|
lines of code that resets the OID and let's us extract the key. */ |
540 |
|
if (OBJ_obj2nid(cert->cert_info->key->algor->algorithm) == NID_md5WithRSAEncryption) |
541 |
|
{ |
542 |
|
DEBUG_RDP5(("Re-setting algorithm type to RSA in server certificate\n")); |
543 |
|
cert->cert_info->key->algor->algorithm = OBJ_nid2obj(NID_rsaEncryption); |
544 |
|
} |
545 |
|
epk = X509_get_pubkey(cert); |
546 |
|
if (NULL == epk) |
547 |
|
{ |
548 |
|
error("Failed to extract public key from certificate\n"); |
549 |
|
return False; |
550 |
|
} |
551 |
|
|
552 |
|
server_public_key = (RSA *) epk->pkey.ptr; |
553 |
|
|
554 |
|
return True; |
555 |
|
} |
556 |
|
|
557 |
|
|
558 |
/* Parse a crypto information structure */ |
/* Parse a crypto information structure */ |
559 |
static BOOL |
static BOOL |
560 |
sec_parse_crypt_info(STREAM s, uint32 * rc4_key_size, |
sec_parse_crypt_info(STREAM s, uint32 * rc4_key_size, |
561 |
uint8 ** server_random, uint8 ** modulus, |
uint8 ** server_random, uint8 ** modulus, uint8 ** exponent) |
|
uint8 ** exponent) |
|
562 |
{ |
{ |
563 |
uint32 crypt_level, random_len, rsa_info_len; |
uint32 crypt_level, random_len, rsa_info_len; |
564 |
|
uint32 cacert_len, cert_len, flags; |
565 |
|
X509 *cacert, *server_cert; |
566 |
uint16 tag, length; |
uint16 tag, length; |
567 |
uint8 *next_tag, *end; |
uint8 *next_tag, *end; |
568 |
|
|
569 |
in_uint32_le(s, *rc4_key_size); /* 1 = 40-bit, 2 = 128-bit */ |
in_uint32_le(s, *rc4_key_size); /* 1 = 40-bit, 2 = 128-bit */ |
570 |
in_uint32_le(s, crypt_level); /* 1 = low, 2 = medium, 3 = high */ |
in_uint32_le(s, crypt_level); /* 1 = low, 2 = medium, 3 = high */ |
571 |
|
if (crypt_level == 0) /* no encryption */ |
572 |
|
return False; |
573 |
in_uint32_le(s, random_len); |
in_uint32_le(s, random_len); |
574 |
in_uint32_le(s, rsa_info_len); |
in_uint32_le(s, rsa_info_len); |
575 |
|
|
576 |
if (random_len != SEC_RANDOM_SIZE) |
if (random_len != SEC_RANDOM_SIZE) |
577 |
{ |
{ |
578 |
error("random len %d\n", random_len); |
error("random len %d, expected %d\n", random_len, SEC_RANDOM_SIZE); |
579 |
return False; |
return False; |
580 |
} |
} |
581 |
|
|
586 |
if (end > s->end) |
if (end > s->end) |
587 |
return False; |
return False; |
588 |
|
|
589 |
in_uint8s(s, 12); /* unknown */ |
in_uint32_le(s, flags); /* 1 = RDP4-style, 0x80000002 = X.509 */ |
590 |
|
if (flags & 1) |
591 |
|
{ |
592 |
|
DEBUG_RDP5(("We're going for the RDP4-style encryption\n")); |
593 |
|
in_uint8s(s, 8); /* unknown */ |
594 |
|
|
595 |
|
while (s->p < end) |
596 |
|
{ |
597 |
|
in_uint16_le(s, tag); |
598 |
|
in_uint16_le(s, length); |
599 |
|
|
600 |
|
next_tag = s->p + length; |
601 |
|
|
602 |
|
switch (tag) |
603 |
|
{ |
604 |
|
case SEC_TAG_PUBKEY: |
605 |
|
if (!sec_parse_public_key(s, modulus, exponent)) |
606 |
|
return False; |
607 |
|
DEBUG_RDP5(("Got Public key, RDP4-style\n")); |
608 |
|
|
609 |
|
break; |
610 |
|
|
611 |
|
case SEC_TAG_KEYSIG: |
612 |
|
/* Is this a Microsoft key that we just got? */ |
613 |
|
/* Care factor: zero! */ |
614 |
|
/* Actually, it would probably be a good idea to check if the public key is signed with this key, and then store this |
615 |
|
key as a known key of the hostname. This would prevent some MITM-attacks. */ |
616 |
|
break; |
617 |
|
|
618 |
|
default: |
619 |
|
unimpl("crypt tag 0x%x\n", tag); |
620 |
|
} |
621 |
|
|
622 |
while (s->p < end) |
s->p = next_tag; |
623 |
|
} |
624 |
|
} |
625 |
|
else |
626 |
{ |
{ |
627 |
in_uint16_le(s, tag); |
DEBUG_RDP5(("We're going for the RDP5-style encryption\n")); |
628 |
in_uint16_le(s, length); |
in_uint8s(s, 4); /* Number of certificates */ |
629 |
|
|
630 |
next_tag = s->p + length; |
/* Do da funky X.509 stuffy |
631 |
|
|
632 |
switch (tag) |
"How did I find out about this? I looked up and saw a |
633 |
|
bright light and when I came to I had a scar on my forehead |
634 |
|
and knew about X.500" |
635 |
|
- Peter Gutman in a early version of |
636 |
|
http://www.cs.auckland.ac.nz/~pgut001/pubs/x509guide.txt |
637 |
|
*/ |
638 |
|
|
639 |
|
in_uint32_le(s, cacert_len); |
640 |
|
DEBUG_RDP5(("CA Certificate length is %d\n", cacert_len)); |
641 |
|
cacert = d2i_X509(NULL, &(s->p), cacert_len); |
642 |
|
/* Note: We don't need to move s->p here - d2i_X509 is |
643 |
|
"kind" enough to do it for us */ |
644 |
|
if (NULL == cacert) |
645 |
{ |
{ |
646 |
case SEC_TAG_PUBKEY: |
error("Couldn't load CA Certificate from server\n"); |
647 |
if (!sec_parse_public_key |
return False; |
648 |
(s, modulus, exponent)) |
} |
|
return False; |
|
649 |
|
|
650 |
break; |
/* Currently, we don't use the CA Certificate. |
651 |
|
FIXME: |
652 |
|
*) Verify the server certificate (server_cert) with the |
653 |
|
CA certificate. |
654 |
|
*) Store the CA Certificate with the hostname of the |
655 |
|
server we are connecting to as key, and compare it |
656 |
|
when we connect the next time, in order to prevent |
657 |
|
MITM-attacks. |
658 |
|
*/ |
659 |
|
|
660 |
|
in_uint32_le(s, cert_len); |
661 |
|
DEBUG_RDP5(("Certificate length is %d\n", cert_len)); |
662 |
|
server_cert = d2i_X509(NULL, &(s->p), cert_len); |
663 |
|
if (NULL == server_cert) |
664 |
|
{ |
665 |
|
error("Couldn't load Certificate from server\n"); |
666 |
|
return False; |
667 |
|
} |
668 |
|
|
669 |
case SEC_TAG_KEYSIG: |
in_uint8s(s, 16); /* Padding */ |
|
/* Is this a Microsoft key that we just got? */ |
|
|
/* Care factor: zero! */ |
|
|
break; |
|
670 |
|
|
671 |
default: |
/* Note: Verifying the server certificate must be done here, |
672 |
unimpl("crypt tag 0x%x\n", tag); |
before sec_parse_public_key since we'll have to apply |
673 |
} |
serious violence to the key after this */ |
674 |
|
|
675 |
s->p = next_tag; |
if (!sec_parse_x509_key(server_cert)) |
676 |
|
{ |
677 |
|
DEBUG_RDP5(("Didn't parse X509 correctly\n")); |
678 |
|
return False; |
679 |
|
} |
680 |
|
return True; /* There's some garbage here we don't care about */ |
681 |
} |
} |
|
|
|
682 |
return s_check_end(s); |
return s_check_end(s); |
683 |
} |
} |
684 |
|
|
689 |
uint8 *server_random, *modulus, *exponent; |
uint8 *server_random, *modulus, *exponent; |
690 |
uint8 client_random[SEC_RANDOM_SIZE]; |
uint8 client_random[SEC_RANDOM_SIZE]; |
691 |
uint32 rc4_key_size; |
uint32 rc4_key_size; |
692 |
|
uint8 inr[SEC_MODULUS_SIZE]; |
693 |
|
|
694 |
if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, |
if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, &modulus, &exponent)) |
695 |
&modulus, &exponent)) |
{ |
696 |
|
DEBUG(("Failed to parse crypt info\n")); |
697 |
return; |
return; |
698 |
|
} |
699 |
|
|
700 |
|
DEBUG(("Generating client random\n")); |
701 |
/* Generate a client random, and hence determine encryption keys */ |
/* Generate a client random, and hence determine encryption keys */ |
702 |
|
// This is what the MS client do: |
703 |
|
memset(inr, 0, SEC_RANDOM_SIZE); |
704 |
|
/* *ARIGL!* Plaintext attack, anyone? |
705 |
|
I tried doing: |
706 |
|
generate_random(inr); |
707 |
|
..but that generates connection errors now and then (yes, |
708 |
|
"now and then". Something like 0 to 3 attempts needed before a |
709 |
|
successful connection. Nice. Not! |
710 |
|
*/ |
711 |
|
|
712 |
generate_random(client_random); |
generate_random(client_random); |
713 |
sec_rsa_encrypt(sec_crypted_random, client_random, |
if (NULL != server_public_key) |
714 |
SEC_RANDOM_SIZE, modulus, exponent); |
{ /* Which means we should use |
715 |
|
RDP5-style encryption */ |
716 |
|
|
717 |
|
memcpy(inr + SEC_RANDOM_SIZE, client_random, SEC_RANDOM_SIZE); |
718 |
|
reverse(inr + SEC_RANDOM_SIZE, SEC_RANDOM_SIZE); |
719 |
|
|
720 |
|
RSA_public_encrypt(SEC_MODULUS_SIZE, |
721 |
|
inr, sec_crypted_random, server_public_key, RSA_NO_PADDING); |
722 |
|
|
723 |
|
reverse(sec_crypted_random, SEC_MODULUS_SIZE); |
724 |
|
|
725 |
|
} |
726 |
|
else |
727 |
|
{ /* RDP4-style encryption */ |
728 |
|
sec_rsa_encrypt(sec_crypted_random, |
729 |
|
client_random, SEC_RANDOM_SIZE, modulus, exponent); |
730 |
|
} |
731 |
sec_generate_keys(client_random, server_random, rc4_key_size); |
sec_generate_keys(client_random, server_random, rc4_key_size); |
732 |
} |
} |
733 |
|
|
734 |
/* Process connect response data blob */ |
|
735 |
|
/* Process SRV_INFO, find RDP version supported by server */ |
736 |
static void |
static void |
737 |
|
sec_process_srv_info(STREAM s) |
738 |
|
{ |
739 |
|
in_uint16_le(s, g_server_rdp_version); |
740 |
|
DEBUG_RDP5(("Server RDP version is %d\n", g_server_rdp_version)); |
741 |
|
if (1 == g_server_rdp_version) |
742 |
|
g_use_rdp5 = 0; |
743 |
|
} |
744 |
|
|
745 |
|
|
746 |
|
/* Process connect response data blob */ |
747 |
|
void |
748 |
sec_process_mcs_data(STREAM s) |
sec_process_mcs_data(STREAM s) |
749 |
{ |
{ |
750 |
uint16 tag, length; |
uint16 tag, length; |
751 |
uint8 *next_tag; |
uint8 *next_tag; |
752 |
|
uint8 len; |
753 |
|
|
754 |
in_uint8s(s, 23); /* header */ |
in_uint8s(s, 21); /* header (T.124 stuff, probably) */ |
755 |
|
in_uint8(s, len); |
756 |
|
if (len & 0x80) |
757 |
|
in_uint8(s, len); |
758 |
|
|
759 |
while (s->p < s->end) |
while (s->p < s->end) |
760 |
{ |
{ |
769 |
switch (tag) |
switch (tag) |
770 |
{ |
{ |
771 |
case SEC_TAG_SRV_INFO: |
case SEC_TAG_SRV_INFO: |
772 |
case SEC_TAG_SRV_3: |
sec_process_srv_info(s); |
773 |
break; |
break; |
774 |
|
|
775 |
case SEC_TAG_SRV_CRYPT: |
case SEC_TAG_SRV_CRYPT: |
776 |
sec_process_crypt_info(s); |
sec_process_crypt_info(s); |
777 |
break; |
break; |
778 |
|
|
779 |
|
case SEC_TAG_SRV_CHANNELS: |
780 |
|
/* FIXME: We should parse this information and |
781 |
|
use it to map RDP5 channels to MCS |
782 |
|
channels */ |
783 |
|
break; |
784 |
|
|
785 |
default: |
default: |
786 |
unimpl("response tag 0x%x\n", tag); |
unimpl("response tag 0x%x\n", tag); |
787 |
} |
} |
792 |
|
|
793 |
/* Receive secure transport packet */ |
/* Receive secure transport packet */ |
794 |
STREAM |
STREAM |
795 |
sec_recv() |
sec_recv(void) |
796 |
{ |
{ |
797 |
uint32 sec_flags; |
uint32 sec_flags; |
798 |
|
uint16 channel; |
799 |
STREAM s; |
STREAM s; |
800 |
|
|
801 |
while ((s = mcs_recv()) != NULL) |
while ((s = mcs_recv(&channel)) != NULL) |
802 |
{ |
{ |
803 |
if (encryption || !licence_issued) |
if (g_encryption || !g_licence_issued) |
804 |
{ |
{ |
805 |
in_uint32_le(s, sec_flags); |
in_uint32_le(s, sec_flags); |
806 |
|
|
807 |
|
if (sec_flags & SEC_ENCRYPT) |
808 |
|
{ |
809 |
|
in_uint8s(s, 8); /* signature */ |
810 |
|
sec_decrypt(s->p, s->end - s->p); |
811 |
|
} |
812 |
|
|
813 |
if (sec_flags & SEC_LICENCE_NEG) |
if (sec_flags & SEC_LICENCE_NEG) |
814 |
{ |
{ |
815 |
licence_process(s); |
licence_process(s); |
816 |
continue; |
continue; |
817 |
} |
} |
818 |
|
} |
819 |
|
|
820 |
if (sec_flags & SEC_ENCRYPT) |
if (channel != MCS_GLOBAL_CHANNEL) |
821 |
{ |
{ |
822 |
in_uint8s(s, 8); /* signature */ |
channel_process(s, channel); |
823 |
sec_decrypt(s->p, s->end - s->p); |
continue; |
|
} |
|
824 |
} |
} |
825 |
|
|
826 |
return s; |
return s; |
831 |
|
|
832 |
/* Establish a secure connection */ |
/* Establish a secure connection */ |
833 |
BOOL |
BOOL |
834 |
sec_connect(char *server) |
sec_connect(char *server, char *username) |
835 |
{ |
{ |
836 |
struct stream mcs_data; |
struct stream mcs_data; |
837 |
|
|
838 |
/* We exchange some RDP data during the MCS-Connect */ |
/* We exchange some RDP data during the MCS-Connect */ |
839 |
mcs_data.size = 512; |
mcs_data.size = 512; |
840 |
mcs_data.p = mcs_data.data = xmalloc(mcs_data.size); |
mcs_data.p = mcs_data.data = (uint8 *) xmalloc(mcs_data.size); |
841 |
sec_out_mcs_data(&mcs_data); |
sec_out_mcs_data(&mcs_data); |
842 |
|
|
843 |
if (!mcs_connect(server, &mcs_data)) |
if (!mcs_connect(server, &mcs_data, username)) |
844 |
return False; |
return False; |
845 |
|
|
846 |
sec_process_mcs_data(&mcs_data); |
// sec_process_mcs_data(&mcs_data); |
847 |
if (encryption) |
if (g_encryption) |
848 |
sec_establish_key(); |
sec_establish_key(); |
849 |
|
xfree(mcs_data.data); |
850 |
return True; |
return True; |
851 |
} |
} |
852 |
|
|
853 |
/* Disconnect a connection */ |
/* Disconnect a connection */ |
854 |
void |
void |
855 |
sec_disconnect() |
sec_disconnect(void) |
856 |
{ |
{ |
857 |
mcs_disconnect(); |
mcs_disconnect(); |
858 |
} |
} |