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" |
34 |
#endif |
#endif |
35 |
|
|
36 |
extern char hostname[16]; |
extern char hostname[16]; |
37 |
extern int width; |
extern int g_width; |
38 |
extern int height; |
extern int g_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 BOOL g_console_session; |
44 |
|
extern int g_server_bpp; |
45 |
|
extern uint16 mcs_userid; |
46 |
|
extern VCHANNEL g_channels[]; |
47 |
|
extern unsigned int g_num_channels; |
48 |
|
|
49 |
static int rc4_key_len; |
static int rc4_key_len; |
50 |
static RC4_KEY rc4_decrypt_key; |
static RC4_KEY rc4_decrypt_key; |
51 |
static RC4_KEY rc4_encrypt_key; |
static RC4_KEY rc4_encrypt_key; |
52 |
|
static RSA *server_public_key; |
53 |
|
|
54 |
static uint8 sec_sign_key[16]; |
static uint8 sec_sign_key[16]; |
55 |
static uint8 sec_decrypt_key[16]; |
static uint8 sec_decrypt_key[16]; |
58 |
static uint8 sec_encrypt_update_key[16]; |
static uint8 sec_encrypt_update_key[16]; |
59 |
static uint8 sec_crypted_random[SEC_MODULUS_SIZE]; |
static uint8 sec_crypted_random[SEC_MODULUS_SIZE]; |
60 |
|
|
61 |
|
uint16 g_server_rdp_version = 0; |
62 |
|
|
63 |
/* |
/* |
64 |
* General purpose 48-byte transformation, using two 32-byte salts (generally, |
* General purpose 48-byte transformation, using two 32-byte salts (generally, |
65 |
* 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. |
150 |
} |
} |
151 |
else |
else |
152 |
{ |
{ |
153 |
DEBUG(("128-bit encryption enabled\n")); |
DEBUG(("rc_4_key_size == %d, 128-bit encryption enabled\n", rc4_key_size)); |
154 |
rc4_key_len = 16; |
rc4_key_len = 16; |
155 |
} |
} |
156 |
|
|
261 |
} |
} |
262 |
|
|
263 |
/* Decrypt data using RC4 */ |
/* Decrypt data using RC4 */ |
264 |
static void |
void |
265 |
sec_decrypt(uint8 * data, int length) |
sec_decrypt(uint8 * data, int length) |
266 |
{ |
{ |
267 |
static int use_count; |
static int use_count; |
295 |
static void |
static void |
296 |
sec_rsa_encrypt(uint8 * out, uint8 * in, int len, uint8 * modulus, uint8 * exponent) |
sec_rsa_encrypt(uint8 * out, uint8 * in, int len, uint8 * modulus, uint8 * exponent) |
297 |
{ |
{ |
298 |
BN_CTX ctx; |
BN_CTX *ctx; |
299 |
BIGNUM mod, exp, x, y; |
BIGNUM mod, exp, x, y; |
300 |
uint8 inr[SEC_MODULUS_SIZE]; |
uint8 inr[SEC_MODULUS_SIZE]; |
301 |
int outlen; |
int outlen; |
305 |
memcpy(inr, in, len); |
memcpy(inr, in, len); |
306 |
reverse(inr, len); |
reverse(inr, len); |
307 |
|
|
308 |
BN_CTX_init(&ctx); |
ctx = BN_CTX_new(); |
309 |
BN_init(&mod); |
BN_init(&mod); |
310 |
BN_init(&exp); |
BN_init(&exp); |
311 |
BN_init(&x); |
BN_init(&x); |
314 |
BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod); |
BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod); |
315 |
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp); |
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp); |
316 |
BN_bin2bn(inr, len, &x); |
BN_bin2bn(inr, len, &x); |
317 |
BN_mod_exp(&y, &x, &exp, &mod, &ctx); |
BN_mod_exp(&y, &x, &exp, &mod, ctx); |
318 |
outlen = BN_bn2bin(&y, out); |
outlen = BN_bn2bin(&y, out); |
319 |
reverse(out, outlen); |
reverse(out, outlen); |
320 |
if (outlen < SEC_MODULUS_SIZE) |
if (outlen < SEC_MODULUS_SIZE) |
324 |
BN_clear_free(&x); |
BN_clear_free(&x); |
325 |
BN_free(&exp); |
BN_free(&exp); |
326 |
BN_free(&mod); |
BN_free(&mod); |
327 |
BN_CTX_free(&ctx); |
BN_CTX_free(ctx); |
328 |
} |
} |
329 |
|
|
330 |
/* Initialise secure transport packet */ |
/* Initialise secure transport packet */ |
334 |
int hdrlen; |
int hdrlen; |
335 |
STREAM s; |
STREAM s; |
336 |
|
|
337 |
if (!licence_issued) |
if (!g_licence_issued) |
338 |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 4; |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 4; |
339 |
else |
else |
340 |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 0; |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 0; |
344 |
return s; |
return s; |
345 |
} |
} |
346 |
|
|
347 |
/* Transmit secure transport packet */ |
/* Transmit secure transport packet over specified channel */ |
348 |
void |
void |
349 |
sec_send(STREAM s, uint32 flags) |
sec_send_to_channel(STREAM s, uint32 flags, uint16 channel) |
350 |
{ |
{ |
351 |
int datalen; |
int datalen; |
352 |
|
|
353 |
s_pop_layer(s, sec_hdr); |
s_pop_layer(s, sec_hdr); |
354 |
if (!licence_issued || (flags & SEC_ENCRYPT)) |
if (!g_licence_issued || (flags & SEC_ENCRYPT)) |
355 |
out_uint32_le(s, flags); |
out_uint32_le(s, flags); |
356 |
|
|
357 |
if (flags & SEC_ENCRYPT) |
if (flags & SEC_ENCRYPT) |
368 |
sec_encrypt(s->p + 8, datalen); |
sec_encrypt(s->p + 8, datalen); |
369 |
} |
} |
370 |
|
|
371 |
mcs_send(s); |
mcs_send_to_channel(s, channel); |
372 |
|
} |
373 |
|
|
374 |
|
/* Transmit secure transport packet */ |
375 |
|
|
376 |
|
void |
377 |
|
sec_send(STREAM s, uint32 flags) |
378 |
|
{ |
379 |
|
sec_send_to_channel(s, flags, MCS_GLOBAL_CHANNEL); |
380 |
} |
} |
381 |
|
|
382 |
|
|
383 |
/* Transfer the client random to the server */ |
/* Transfer the client random to the server */ |
384 |
static void |
static void |
385 |
sec_establish_key() |
sec_establish_key(void) |
386 |
{ |
{ |
387 |
uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE; |
uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE; |
388 |
uint32 flags = SEC_CLIENT_RANDOM; |
uint32 flags = SEC_CLIENT_RANDOM; |
403 |
sec_out_mcs_data(STREAM s) |
sec_out_mcs_data(STREAM s) |
404 |
{ |
{ |
405 |
int hostlen = 2 * strlen(hostname); |
int hostlen = 2 * strlen(hostname); |
406 |
|
int length = 158 + 76 + 12 + 4; |
407 |
|
unsigned int i; |
408 |
|
|
409 |
|
if (g_num_channels > 0) |
410 |
|
length += g_num_channels * 12 + 8; |
411 |
|
|
412 |
if (hostlen > 30) |
if (hostlen > 30) |
413 |
hostlen = 30; |
hostlen = 30; |
417 |
out_uint8(s, 0x7c); |
out_uint8(s, 0x7c); |
418 |
out_uint16_be(s, 1); |
out_uint16_be(s, 1); |
419 |
|
|
420 |
out_uint16_be(s, (158 | 0x8000)); /* remaining length */ |
out_uint16_be(s, (length | 0x8000)); /* remaining length */ |
421 |
|
|
422 |
out_uint16_be(s, 8); /* length? */ |
out_uint16_be(s, 8); /* length? */ |
423 |
out_uint16_be(s, 16); |
out_uint16_be(s, 16); |
426 |
out_uint8(s, 0); |
out_uint8(s, 0); |
427 |
|
|
428 |
out_uint32_le(s, 0x61637544); /* "Duca" ?! */ |
out_uint32_le(s, 0x61637544); /* "Duca" ?! */ |
429 |
out_uint16_be(s, (144 | 0x8000)); /* remaining length */ |
out_uint16_be(s, ((length - 14) | 0x8000)); /* remaining length */ |
430 |
|
|
431 |
/* Client information */ |
/* Client information */ |
432 |
out_uint16_le(s, SEC_TAG_CLI_INFO); |
out_uint16_le(s, SEC_TAG_CLI_INFO); |
433 |
out_uint16_le(s, 136); /* length */ |
out_uint16_le(s, 212); /* length */ |
434 |
out_uint16_le(s, 1); |
out_uint16_le(s, g_use_rdp5 ? 4 : 1); /* RDP version. 1 == RDP4, 4 == RDP5. */ |
435 |
out_uint16_le(s, 8); |
out_uint16_le(s, 8); |
436 |
out_uint16_le(s, width); |
out_uint16_le(s, g_width); |
437 |
out_uint16_le(s, height); |
out_uint16_le(s, g_height); |
438 |
out_uint16_le(s, 0xca01); |
out_uint16_le(s, 0xca01); |
439 |
out_uint16_le(s, 0xaa03); |
out_uint16_le(s, 0xaa03); |
440 |
out_uint32_le(s, keylayout); |
out_uint32_le(s, keylayout); |
441 |
out_uint32_le(s, 419); /* client build? we are 419 compatible :-) */ |
out_uint32_le(s, 2600); /* Client build. We are now 2600 compatible :-) */ |
442 |
|
|
443 |
/* Unicode name of client, padded to 32 bytes */ |
/* Unicode name of client, padded to 32 bytes */ |
444 |
rdp_out_unistr(s, hostname, hostlen); |
rdp_out_unistr(s, hostname, hostlen); |
449 |
out_uint32_le(s, 12); |
out_uint32_le(s, 12); |
450 |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
451 |
|
|
452 |
out_uint16_le(s, 0xca01); |
switch (g_server_bpp) |
453 |
out_uint16(s, 0); |
{ |
454 |
|
case 8: |
455 |
|
out_uint16_le(s, 0xca01); |
456 |
|
break; |
457 |
|
case 15: |
458 |
|
out_uint16_le(s, 0xca02); |
459 |
|
break; |
460 |
|
case 16: |
461 |
|
out_uint16_le(s, 0xca03); |
462 |
|
break; |
463 |
|
case 24: |
464 |
|
out_uint16_le(s, 0xca04); |
465 |
|
break; |
466 |
|
} |
467 |
|
out_uint16_le(s, 1); |
468 |
|
|
469 |
|
out_uint32(s, 0); |
470 |
|
out_uint8(s, g_server_bpp); |
471 |
|
out_uint16_le(s, 0x0700); |
472 |
|
out_uint8(s, 0); |
473 |
|
out_uint32_le(s, 1); |
474 |
|
out_uint8s(s, 64); /* End of client info */ |
475 |
|
|
476 |
|
out_uint16_le(s, SEC_TAG_CLI_4); |
477 |
|
out_uint16_le(s, 12); |
478 |
|
out_uint32_le(s, g_console_session ? 0xb : 9); |
479 |
|
out_uint32(s, 0); |
480 |
|
|
481 |
/* Client encryption settings */ |
/* Client encryption settings */ |
482 |
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
483 |
out_uint16_le(s, 8); /* length */ |
out_uint16_le(s, 12); /* length */ |
484 |
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 */ |
485 |
|
out_uint32(s, 0); /* Unknown */ |
486 |
|
|
487 |
|
DEBUG_RDP5(("g_num_channels is %d\n", g_num_channels)); |
488 |
|
if (g_num_channels > 0) |
489 |
|
{ |
490 |
|
out_uint16_le(s, SEC_TAG_CLI_CHANNELS); |
491 |
|
out_uint16_le(s, g_num_channels * 12 + 8); /* length */ |
492 |
|
out_uint32_le(s, g_num_channels); /* number of virtual channels */ |
493 |
|
for (i = 0; i < g_num_channels; i++) |
494 |
|
{ |
495 |
|
DEBUG_RDP5(("Requesting channel %s\n", g_channels[i].name)); |
496 |
|
out_uint8a(s, g_channels[i].name, 8); |
497 |
|
out_uint32_be(s, g_channels[i].flags); |
498 |
|
} |
499 |
|
} |
500 |
|
|
501 |
s_mark_end(s); |
s_mark_end(s); |
502 |
} |
} |
503 |
|
|
529 |
return s_check(s); |
return s_check(s); |
530 |
} |
} |
531 |
|
|
532 |
|
static BOOL |
533 |
|
sec_parse_x509_key(X509 * cert) |
534 |
|
{ |
535 |
|
EVP_PKEY *epk = NULL; |
536 |
|
/* By some reason, Microsoft sets the OID of the Public RSA key to |
537 |
|
the oid for "MD5 with RSA Encryption" instead of "RSA Encryption" |
538 |
|
|
539 |
|
Kudos to Richard Levitte for the following (. intiutive .) |
540 |
|
lines of code that resets the OID and let's us extract the key. */ |
541 |
|
if (OBJ_obj2nid(cert->cert_info->key->algor->algorithm) == NID_md5WithRSAEncryption) |
542 |
|
{ |
543 |
|
DEBUG_RDP5(("Re-setting algorithm type to RSA in server certificate\n")); |
544 |
|
cert->cert_info->key->algor->algorithm = OBJ_nid2obj(NID_rsaEncryption); |
545 |
|
} |
546 |
|
epk = X509_get_pubkey(cert); |
547 |
|
if (NULL == epk) |
548 |
|
{ |
549 |
|
error("Failed to extract public key from certificate\n"); |
550 |
|
return False; |
551 |
|
} |
552 |
|
|
553 |
|
server_public_key = (RSA *) epk->pkey.ptr; |
554 |
|
|
555 |
|
return True; |
556 |
|
} |
557 |
|
|
558 |
|
|
559 |
/* Parse a crypto information structure */ |
/* Parse a crypto information structure */ |
560 |
static BOOL |
static BOOL |
561 |
sec_parse_crypt_info(STREAM s, uint32 * rc4_key_size, |
sec_parse_crypt_info(STREAM s, uint32 * rc4_key_size, |
562 |
uint8 ** server_random, uint8 ** modulus, uint8 ** exponent) |
uint8 ** server_random, uint8 ** modulus, uint8 ** exponent) |
563 |
{ |
{ |
564 |
uint32 crypt_level, random_len, rsa_info_len; |
uint32 crypt_level, random_len, rsa_info_len; |
565 |
|
uint32 cacert_len, cert_len, flags; |
566 |
|
X509 *cacert, *server_cert; |
567 |
uint16 tag, length; |
uint16 tag, length; |
568 |
uint8 *next_tag, *end; |
uint8 *next_tag, *end; |
569 |
|
|
570 |
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 */ |
571 |
in_uint32_le(s, crypt_level); /* 1 = low, 2 = medium, 3 = high */ |
in_uint32_le(s, crypt_level); /* 1 = low, 2 = medium, 3 = high */ |
572 |
if (crypt_level == 0) /* no encryptation */ |
if (crypt_level == 0) /* no encryption */ |
573 |
return False; |
return False; |
574 |
in_uint32_le(s, random_len); |
in_uint32_le(s, random_len); |
575 |
in_uint32_le(s, rsa_info_len); |
in_uint32_le(s, rsa_info_len); |
576 |
|
|
577 |
if (random_len != SEC_RANDOM_SIZE) |
if (random_len != SEC_RANDOM_SIZE) |
578 |
{ |
{ |
579 |
error("random len %d\n", random_len); |
error("random len %d, expected %d\n", random_len, SEC_RANDOM_SIZE); |
580 |
return False; |
return False; |
581 |
} |
} |
582 |
|
|
587 |
if (end > s->end) |
if (end > s->end) |
588 |
return False; |
return False; |
589 |
|
|
590 |
in_uint8s(s, 12); /* unknown */ |
in_uint32_le(s, flags); /* 1 = RDP4-style, 0x80000002 = X.509 */ |
591 |
|
if (flags & 1) |
592 |
|
{ |
593 |
|
DEBUG_RDP5(("We're going for the RDP4-style encryption\n")); |
594 |
|
in_uint8s(s, 8); /* unknown */ |
595 |
|
|
596 |
|
while (s->p < end) |
597 |
|
{ |
598 |
|
in_uint16_le(s, tag); |
599 |
|
in_uint16_le(s, length); |
600 |
|
|
601 |
|
next_tag = s->p + length; |
602 |
|
|
603 |
|
switch (tag) |
604 |
|
{ |
605 |
|
case SEC_TAG_PUBKEY: |
606 |
|
if (!sec_parse_public_key(s, modulus, exponent)) |
607 |
|
return False; |
608 |
|
DEBUG_RDP5(("Got Public key, RDP4-style\n")); |
609 |
|
|
610 |
|
break; |
611 |
|
|
612 |
|
case SEC_TAG_KEYSIG: |
613 |
|
/* Is this a Microsoft key that we just got? */ |
614 |
|
/* Care factor: zero! */ |
615 |
|
/* Actually, it would probably be a good idea to check if the public key is signed with this key, and then store this |
616 |
|
key as a known key of the hostname. This would prevent some MITM-attacks. */ |
617 |
|
break; |
618 |
|
|
619 |
while (s->p < end) |
default: |
620 |
|
unimpl("crypt tag 0x%x\n", tag); |
621 |
|
} |
622 |
|
|
623 |
|
s->p = next_tag; |
624 |
|
} |
625 |
|
} |
626 |
|
else |
627 |
{ |
{ |
628 |
in_uint16_le(s, tag); |
uint32 certcount; |
|
in_uint16_le(s, length); |
|
629 |
|
|
630 |
next_tag = s->p + length; |
DEBUG_RDP5(("We're going for the RDP5-style encryption\n")); |
631 |
|
in_uint32_le(s, certcount); /* Number of certificates */ |
632 |
|
|
633 |
switch (tag) |
if (certcount < 2) |
634 |
{ |
{ |
635 |
case SEC_TAG_PUBKEY: |
error("Server didn't send enough X509 certificates\n"); |
636 |
if (!sec_parse_public_key(s, modulus, exponent)) |
return False; |
637 |
return False; |
} |
638 |
|
|
639 |
break; |
for (; certcount > 2; certcount--) |
640 |
|
{ /* ignore all the certificates between the root and the signing CA */ |
641 |
|
uint32 ignorelen; |
642 |
|
X509 *ignorecert; |
643 |
|
|
644 |
|
DEBUG_RDP5(("Ignored certs left: %d\n", certcount)); |
645 |
|
|
646 |
|
in_uint32_le(s, ignorelen); |
647 |
|
DEBUG_RDP5(("Ignored Certificate length is %d\n", ignorelen)); |
648 |
|
ignorecert = d2i_X509(NULL, &(s->p), ignorelen); |
649 |
|
|
650 |
|
if (ignorecert == NULL) |
651 |
|
{ /* XXX: error out? */ |
652 |
|
DEBUG_RDP5(("got a bad cert: this will probably screw up the rest of the communication\n")); |
653 |
|
} |
654 |
|
|
655 |
case SEC_TAG_KEYSIG: |
#ifdef WITH_DEBUG_RDP5 |
656 |
/* Is this a Microsoft key that we just got? */ |
DEBUG_RDP5(("cert #%d (ignored):\n", certcount)); |
657 |
/* Care factor: zero! */ |
X509_print_fp(stdout, ignorecert); |
658 |
break; |
#endif |
659 |
|
} |
660 |
|
|
661 |
default: |
/* Do da funky X.509 stuffy |
662 |
unimpl("crypt tag 0x%x\n", tag); |
|
663 |
|
"How did I find out about this? I looked up and saw a |
664 |
|
bright light and when I came to I had a scar on my forehead |
665 |
|
and knew about X.500" |
666 |
|
- Peter Gutman in a early version of |
667 |
|
http://www.cs.auckland.ac.nz/~pgut001/pubs/x509guide.txt |
668 |
|
*/ |
669 |
|
|
670 |
|
in_uint32_le(s, cacert_len); |
671 |
|
DEBUG_RDP5(("CA Certificate length is %d\n", cacert_len)); |
672 |
|
cacert = d2i_X509(NULL, &(s->p), cacert_len); |
673 |
|
/* Note: We don't need to move s->p here - d2i_X509 is |
674 |
|
"kind" enough to do it for us */ |
675 |
|
if (NULL == cacert) |
676 |
|
{ |
677 |
|
error("Couldn't load CA Certificate from server\n"); |
678 |
|
return False; |
679 |
} |
} |
680 |
|
|
681 |
s->p = next_tag; |
/* Currently, we don't use the CA Certificate. |
682 |
} |
FIXME: |
683 |
|
*) Verify the server certificate (server_cert) with the |
684 |
|
CA certificate. |
685 |
|
*) Store the CA Certificate with the hostname of the |
686 |
|
server we are connecting to as key, and compare it |
687 |
|
when we connect the next time, in order to prevent |
688 |
|
MITM-attacks. |
689 |
|
*/ |
690 |
|
|
691 |
|
in_uint32_le(s, cert_len); |
692 |
|
DEBUG_RDP5(("Certificate length is %d\n", cert_len)); |
693 |
|
server_cert = d2i_X509(NULL, &(s->p), cert_len); |
694 |
|
if (NULL == server_cert) |
695 |
|
{ |
696 |
|
error("Couldn't load Certificate from server\n"); |
697 |
|
return False; |
698 |
|
} |
699 |
|
|
700 |
|
in_uint8s(s, 16); /* Padding */ |
701 |
|
|
702 |
|
/* Note: Verifying the server certificate must be done here, |
703 |
|
before sec_parse_public_key since we'll have to apply |
704 |
|
serious violence to the key after this */ |
705 |
|
|
706 |
|
if (!sec_parse_x509_key(server_cert)) |
707 |
|
{ |
708 |
|
DEBUG_RDP5(("Didn't parse X509 correctly\n")); |
709 |
|
return False; |
710 |
|
} |
711 |
|
return True; /* There's some garbage here we don't care about */ |
712 |
|
} |
713 |
return s_check_end(s); |
return s_check_end(s); |
714 |
} |
} |
715 |
|
|
720 |
uint8 *server_random, *modulus, *exponent; |
uint8 *server_random, *modulus, *exponent; |
721 |
uint8 client_random[SEC_RANDOM_SIZE]; |
uint8 client_random[SEC_RANDOM_SIZE]; |
722 |
uint32 rc4_key_size; |
uint32 rc4_key_size; |
723 |
|
uint8 inr[SEC_MODULUS_SIZE]; |
724 |
|
|
725 |
if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, &modulus, &exponent)) |
if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, &modulus, &exponent)) |
726 |
|
{ |
727 |
|
DEBUG(("Failed to parse crypt info\n")); |
728 |
return; |
return; |
729 |
|
} |
730 |
|
|
731 |
|
DEBUG(("Generating client random\n")); |
732 |
/* Generate a client random, and hence determine encryption keys */ |
/* Generate a client random, and hence determine encryption keys */ |
733 |
|
/* This is what the MS client do: */ |
734 |
|
memset(inr, 0, SEC_RANDOM_SIZE); |
735 |
|
/* *ARIGL!* Plaintext attack, anyone? |
736 |
|
I tried doing: |
737 |
|
generate_random(inr); |
738 |
|
..but that generates connection errors now and then (yes, |
739 |
|
"now and then". Something like 0 to 3 attempts needed before a |
740 |
|
successful connection. Nice. Not! |
741 |
|
*/ |
742 |
|
|
743 |
generate_random(client_random); |
generate_random(client_random); |
744 |
sec_rsa_encrypt(sec_crypted_random, client_random, SEC_RANDOM_SIZE, modulus, exponent); |
if (NULL != server_public_key) |
745 |
|
{ /* Which means we should use |
746 |
|
RDP5-style encryption */ |
747 |
|
|
748 |
|
memcpy(inr + SEC_RANDOM_SIZE, client_random, SEC_RANDOM_SIZE); |
749 |
|
reverse(inr + SEC_RANDOM_SIZE, SEC_RANDOM_SIZE); |
750 |
|
|
751 |
|
RSA_public_encrypt(SEC_MODULUS_SIZE, |
752 |
|
inr, sec_crypted_random, server_public_key, RSA_NO_PADDING); |
753 |
|
|
754 |
|
reverse(sec_crypted_random, SEC_MODULUS_SIZE); |
755 |
|
|
756 |
|
} |
757 |
|
else |
758 |
|
{ /* RDP4-style encryption */ |
759 |
|
sec_rsa_encrypt(sec_crypted_random, |
760 |
|
client_random, SEC_RANDOM_SIZE, modulus, exponent); |
761 |
|
} |
762 |
sec_generate_keys(client_random, server_random, rc4_key_size); |
sec_generate_keys(client_random, server_random, rc4_key_size); |
763 |
} |
} |
764 |
|
|
765 |
/* Process connect response data blob */ |
|
766 |
|
/* Process SRV_INFO, find RDP version supported by server */ |
767 |
static void |
static void |
768 |
|
sec_process_srv_info(STREAM s) |
769 |
|
{ |
770 |
|
in_uint16_le(s, g_server_rdp_version); |
771 |
|
DEBUG_RDP5(("Server RDP version is %d\n", g_server_rdp_version)); |
772 |
|
if (1 == g_server_rdp_version) |
773 |
|
g_use_rdp5 = 0; |
774 |
|
} |
775 |
|
|
776 |
|
|
777 |
|
/* Process connect response data blob */ |
778 |
|
void |
779 |
sec_process_mcs_data(STREAM s) |
sec_process_mcs_data(STREAM s) |
780 |
{ |
{ |
781 |
uint16 tag, length; |
uint16 tag, length; |
782 |
uint8 *next_tag; |
uint8 *next_tag; |
783 |
uint8 len; |
uint8 len; |
784 |
|
|
785 |
in_uint8s(s, 21); /* header */ |
in_uint8s(s, 21); /* header (T.124 stuff, probably) */ |
786 |
in_uint8(s, len); |
in_uint8(s, len); |
787 |
if (len & 0x80) |
if (len & 0x80) |
788 |
in_uint8(s, len); |
in_uint8(s, len); |
800 |
switch (tag) |
switch (tag) |
801 |
{ |
{ |
802 |
case SEC_TAG_SRV_INFO: |
case SEC_TAG_SRV_INFO: |
803 |
case SEC_TAG_SRV_3: |
sec_process_srv_info(s); |
804 |
break; |
break; |
805 |
|
|
806 |
case SEC_TAG_SRV_CRYPT: |
case SEC_TAG_SRV_CRYPT: |
807 |
sec_process_crypt_info(s); |
sec_process_crypt_info(s); |
808 |
break; |
break; |
809 |
|
|
810 |
|
case SEC_TAG_SRV_CHANNELS: |
811 |
|
/* FIXME: We should parse this information and |
812 |
|
use it to map RDP5 channels to MCS |
813 |
|
channels */ |
814 |
|
break; |
815 |
|
|
816 |
default: |
default: |
817 |
unimpl("response tag 0x%x\n", tag); |
unimpl("response tag 0x%x\n", tag); |
818 |
} |
} |
823 |
|
|
824 |
/* Receive secure transport packet */ |
/* Receive secure transport packet */ |
825 |
STREAM |
STREAM |
826 |
sec_recv() |
sec_recv(void) |
827 |
{ |
{ |
828 |
uint32 sec_flags; |
uint32 sec_flags; |
829 |
|
uint16 channel; |
830 |
STREAM s; |
STREAM s; |
831 |
|
|
832 |
while ((s = mcs_recv()) != NULL) |
while ((s = mcs_recv(&channel)) != NULL) |
833 |
{ |
{ |
834 |
if (encryption || !licence_issued) |
if (g_encryption || !g_licence_issued) |
835 |
{ |
{ |
836 |
in_uint32_le(s, sec_flags); |
in_uint32_le(s, sec_flags); |
837 |
|
|
838 |
|
if (sec_flags & SEC_ENCRYPT) |
839 |
|
{ |
840 |
|
in_uint8s(s, 8); /* signature */ |
841 |
|
sec_decrypt(s->p, s->end - s->p); |
842 |
|
} |
843 |
|
|
844 |
if (sec_flags & SEC_LICENCE_NEG) |
if (sec_flags & SEC_LICENCE_NEG) |
845 |
{ |
{ |
846 |
licence_process(s); |
licence_process(s); |
847 |
continue; |
continue; |
848 |
} |
} |
849 |
|
} |
850 |
|
|
851 |
if (sec_flags & SEC_ENCRYPT) |
if (channel != MCS_GLOBAL_CHANNEL) |
852 |
{ |
{ |
853 |
in_uint8s(s, 8); /* signature */ |
channel_process(s, channel); |
854 |
sec_decrypt(s->p, s->end - s->p); |
continue; |
|
} |
|
855 |
} |
} |
856 |
|
|
857 |
return s; |
return s; |
862 |
|
|
863 |
/* Establish a secure connection */ |
/* Establish a secure connection */ |
864 |
BOOL |
BOOL |
865 |
sec_connect(char *server) |
sec_connect(char *server, char *username) |
866 |
{ |
{ |
867 |
struct stream mcs_data; |
struct stream mcs_data; |
868 |
|
|
869 |
/* We exchange some RDP data during the MCS-Connect */ |
/* We exchange some RDP data during the MCS-Connect */ |
870 |
mcs_data.size = 512; |
mcs_data.size = 512; |
871 |
mcs_data.p = mcs_data.data = xmalloc(mcs_data.size); |
mcs_data.p = mcs_data.data = (uint8 *) xmalloc(mcs_data.size); |
872 |
sec_out_mcs_data(&mcs_data); |
sec_out_mcs_data(&mcs_data); |
873 |
|
|
874 |
if (!mcs_connect(server, &mcs_data)) |
if (!mcs_connect(server, &mcs_data, username)) |
875 |
return False; |
return False; |
876 |
|
|
877 |
sec_process_mcs_data(&mcs_data); |
/* sec_process_mcs_data(&mcs_data); */ |
878 |
if (encryption) |
if (g_encryption) |
879 |
sec_establish_key(); |
sec_establish_key(); |
880 |
|
xfree(mcs_data.data); |
881 |
return True; |
return True; |
882 |
} |
} |
883 |
|
|
884 |
/* Disconnect a connection */ |
/* Disconnect a connection */ |
885 |
void |
void |
886 |
sec_disconnect() |
sec_disconnect(void) |
887 |
{ |
{ |
888 |
mcs_disconnect(); |
mcs_disconnect(); |
889 |
} |
} |