1 |
/* -*- c-basic-offset: 8 -*- |
/* -*- c-basic-offset: 8 -*- |
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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 1999-2002 |
Copyright (C) Matthew Chapman 1999-2005 |
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This program is free software; you can redistribute it and/or modify |
This program is free software; you can redistribute it and/or modify |
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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 |
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#include "rdesktop.h" |
#include "rdesktop.h" |
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#ifdef WITH_OPENSSL |
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23 |
#include <openssl/rc4.h> |
#include <openssl/rc4.h> |
24 |
#include <openssl/md5.h> |
#include <openssl/md5.h> |
25 |
#include <openssl/sha.h> |
#include <openssl/sha.h> |
26 |
#include <openssl/bn.h> |
#include <openssl/bn.h> |
27 |
#include <openssl/x509v3.h> |
#include <openssl/x509v3.h> |
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#else |
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#include "crypto/rc4.h" |
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#include "crypto/md5.h" |
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#include "crypto/sha.h" |
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#include "crypto/bn.h" |
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#endif |
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28 |
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29 |
extern char hostname[16]; |
extern char g_hostname[16]; |
30 |
extern int width; |
extern int g_width; |
31 |
extern int height; |
extern int g_height; |
32 |
extern int keylayout; |
extern int g_keylayout; |
33 |
extern BOOL encryption; |
extern int g_keyboard_type; |
34 |
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extern int g_keyboard_subtype; |
35 |
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extern int g_keyboard_functionkeys; |
36 |
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extern BOOL g_encryption; |
37 |
extern BOOL g_licence_issued; |
extern BOOL g_licence_issued; |
38 |
extern BOOL use_rdp5; |
extern BOOL g_use_rdp5; |
39 |
extern int server_bpp; |
extern BOOL g_console_session; |
40 |
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extern int g_server_bpp; |
41 |
extern uint16 mcs_userid; |
extern uint16 mcs_userid; |
42 |
extern VCHANNEL g_channels[]; |
extern VCHANNEL g_channels[]; |
43 |
extern unsigned int g_num_channels; |
extern unsigned int g_num_channels; |
54 |
static uint8 sec_encrypt_update_key[16]; |
static uint8 sec_encrypt_update_key[16]; |
55 |
static uint8 sec_crypted_random[SEC_MODULUS_SIZE]; |
static uint8 sec_crypted_random[SEC_MODULUS_SIZE]; |
56 |
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57 |
uint16 server_rdp_version = 0; |
uint16 g_server_rdp_version = 0; |
58 |
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59 |
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/* |
60 |
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* I believe this is based on SSLv3 with the following differences: |
61 |
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* MAC algorithm (5.2.3.1) uses only 32-bit length in place of seq_num/type/length fields |
62 |
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* MAC algorithm uses SHA1 and MD5 for the two hash functions instead of one or other |
63 |
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* key_block algorithm (6.2.2) uses 'X', 'YY', 'ZZZ' instead of 'A', 'BB', 'CCC' |
64 |
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* key_block partitioning is different (16 bytes each: MAC secret, decrypt key, encrypt key) |
65 |
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* encryption/decryption keys updated every 4096 packets |
66 |
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* See http://wp.netscape.com/eng/ssl3/draft302.txt |
67 |
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*/ |
68 |
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69 |
/* |
/* |
70 |
* General purpose 48-byte transformation, using two 32-byte salts (generally, |
* 48-byte transformation used to generate master secret (6.1) and key material (6.2.2). |
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* a client and server salt) and a global salt value used for padding. |
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* Both SHA1 and MD5 algorithms are used. |
* Both SHA1 and MD5 algorithms are used. |
72 |
*/ |
*/ |
73 |
void |
void |
98 |
} |
} |
99 |
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100 |
/* |
/* |
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* Weaker 16-byte transformation, also using two 32-byte salts, but |
* 16-byte transformation used to generate export keys (6.2.2). |
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* only using a single round of MD5. |
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102 |
*/ |
*/ |
103 |
void |
void |
104 |
sec_hash_16(uint8 * out, uint8 * in, uint8 * salt1, uint8 * salt2) |
sec_hash_16(uint8 * out, uint8 * in, uint8 * salt1, uint8 * salt2) |
121 |
key[2] = 0x9e; |
key[2] = 0x9e; |
122 |
} |
} |
123 |
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124 |
/* Generate a session key and RC4 keys, given client and server randoms */ |
/* Generate encryption keys given client and server randoms */ |
125 |
static void |
static void |
126 |
sec_generate_keys(uint8 * client_key, uint8 * server_key, int rc4_key_size) |
sec_generate_keys(uint8 * client_random, uint8 * server_random, int rc4_key_size) |
127 |
{ |
{ |
128 |
uint8 session_key[48]; |
uint8 pre_master_secret[48]; |
129 |
uint8 temp_hash[48]; |
uint8 master_secret[48]; |
130 |
uint8 input[48]; |
uint8 key_block[48]; |
131 |
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132 |
/* Construct input data to hash */ |
/* Construct pre-master secret */ |
133 |
memcpy(input, client_key, 24); |
memcpy(pre_master_secret, client_random, 24); |
134 |
memcpy(input + 24, server_key, 24); |
memcpy(pre_master_secret + 24, server_random, 24); |
135 |
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136 |
/* Generate session key - two rounds of sec_hash_48 */ |
/* Generate master secret and then key material */ |
137 |
sec_hash_48(temp_hash, input, client_key, server_key, 65); |
sec_hash_48(master_secret, pre_master_secret, client_random, server_random, 'A'); |
138 |
sec_hash_48(session_key, temp_hash, client_key, server_key, 88); |
sec_hash_48(key_block, master_secret, client_random, server_random, 'X'); |
139 |
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|
140 |
/* Store first 16 bytes of session key, for generating signatures */ |
/* First 16 bytes of key material is MAC secret */ |
141 |
memcpy(sec_sign_key, session_key, 16); |
memcpy(sec_sign_key, key_block, 16); |
142 |
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/* Generate RC4 keys */ |
/* Generate export keys from next two blocks of 16 bytes */ |
144 |
sec_hash_16(sec_decrypt_key, &session_key[16], client_key, server_key); |
sec_hash_16(sec_decrypt_key, &key_block[16], client_random, server_random); |
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sec_hash_16(sec_encrypt_key, &session_key[32], client_key, server_key); |
sec_hash_16(sec_encrypt_key, &key_block[32], client_random, server_random); |
146 |
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|
147 |
if (rc4_key_size == 1) |
if (rc4_key_size == 1) |
148 |
{ |
{ |
191 |
buffer[3] = (value >> 24) & 0xff; |
buffer[3] = (value >> 24) & 0xff; |
192 |
} |
} |
193 |
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194 |
/* Generate a signature hash, using a combination of SHA1 and MD5 */ |
/* Generate a MAC hash (5.2.3.1), using a combination of SHA1 and MD5 */ |
195 |
void |
void |
196 |
sec_sign(uint8 * signature, int siglen, uint8 * session_key, int keylen, uint8 * data, int datalen) |
sec_sign(uint8 * signature, int siglen, uint8 * session_key, int keylen, uint8 * data, int datalen) |
197 |
{ |
{ |
219 |
memcpy(signature, md5sig, siglen); |
memcpy(signature, md5sig, siglen); |
220 |
} |
} |
221 |
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222 |
/* Update an encryption key - similar to the signing process */ |
/* Update an encryption key */ |
223 |
static void |
static void |
224 |
sec_update(uint8 * key, uint8 * update_key) |
sec_update(uint8 * key, uint8 * update_key) |
225 |
{ |
{ |
406 |
static void |
static void |
407 |
sec_out_mcs_data(STREAM s) |
sec_out_mcs_data(STREAM s) |
408 |
{ |
{ |
409 |
int hostlen = 2 * strlen(hostname); |
int hostlen = 2 * strlen(g_hostname); |
410 |
int length = 158 + 76 + 12 + 4; |
int length = 158 + 76 + 12 + 4; |
411 |
unsigned int i; |
unsigned int i; |
412 |
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413 |
if (g_num_channels > 0) |
if (g_num_channels > 0) |
414 |
length += g_num_channels*12 + 8; |
length += g_num_channels * 12 + 8; |
415 |
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416 |
if (hostlen > 30) |
if (hostlen > 30) |
417 |
hostlen = 30; |
hostlen = 30; |
418 |
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419 |
out_uint16_be(s, 5); /* unknown */ |
/* Generic Conference Control (T.124) ConferenceCreateRequest */ |
420 |
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out_uint16_be(s, 5); |
421 |
out_uint16_be(s, 0x14); |
out_uint16_be(s, 0x14); |
422 |
out_uint8(s, 0x7c); |
out_uint8(s, 0x7c); |
423 |
out_uint16_be(s, 1); |
out_uint16_be(s, 1); |
430 |
out_uint16_le(s, 0xc001); |
out_uint16_le(s, 0xc001); |
431 |
out_uint8(s, 0); |
out_uint8(s, 0); |
432 |
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out_uint32_le(s, 0x61637544); /* "Duca" ?! */ |
out_uint32_le(s, 0x61637544); /* OEM ID: "Duca", as in Ducati. */ |
434 |
out_uint16_be(s, ((length - 14) | 0x8000)); /* remaining length */ |
out_uint16_be(s, ((length - 14) | 0x8000)); /* remaining length */ |
435 |
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436 |
/* Client information */ |
/* Client information */ |
437 |
out_uint16_le(s, SEC_TAG_CLI_INFO); |
out_uint16_le(s, SEC_TAG_CLI_INFO); |
438 |
out_uint16_le(s, 212); /* length */ |
out_uint16_le(s, 212); /* length */ |
439 |
out_uint16_le(s, use_rdp5 ? 4 : 1); /* RDP version. 1 == RDP4, 4 == RDP5. */ |
out_uint16_le(s, g_use_rdp5 ? 4 : 1); /* RDP version. 1 == RDP4, 4 == RDP5. */ |
440 |
out_uint16_le(s, 8); |
out_uint16_le(s, 8); |
441 |
out_uint16_le(s, width); |
out_uint16_le(s, g_width); |
442 |
out_uint16_le(s, height); |
out_uint16_le(s, g_height); |
443 |
out_uint16_le(s, 0xca01); |
out_uint16_le(s, 0xca01); |
444 |
out_uint16_le(s, 0xaa03); |
out_uint16_le(s, 0xaa03); |
445 |
out_uint32_le(s, keylayout); |
out_uint32_le(s, g_keylayout); |
446 |
out_uint32_le(s, 2600); /* Client build. We are now 2600 compatible :-) */ |
out_uint32_le(s, 2600); /* Client build. We are now 2600 compatible :-) */ |
447 |
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448 |
/* Unicode name of client, padded to 32 bytes */ |
/* Unicode name of client, padded to 32 bytes */ |
449 |
rdp_out_unistr(s, hostname, hostlen); |
rdp_out_unistr(s, g_hostname, hostlen); |
450 |
out_uint8s(s, 30 - hostlen); |
out_uint8s(s, 30 - hostlen); |
451 |
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452 |
out_uint32_le(s, 4); |
/* See |
453 |
out_uint32(s, 0); |
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wceddk40/html/cxtsksupportingremotedesktopprotocol.asp */ |
454 |
out_uint32_le(s, 12); |
out_uint32_le(s, g_keyboard_type); |
455 |
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out_uint32_le(s, g_keyboard_subtype); |
456 |
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out_uint32_le(s, g_keyboard_functionkeys); |
457 |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
458 |
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out_uint16_le(s, 0xca01); /* colour depth? */ |
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switch (server_bpp) |
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{ |
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case 8: |
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out_uint16_le(s, 0xca01); |
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break; |
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case 15: |
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out_uint16_le(s, 0xca02); |
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break; |
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case 16: |
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out_uint16_le(s, 0xca03); |
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break; |
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case 24: |
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out_uint16_le(s, 0xca04); |
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break; |
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} |
|
459 |
out_uint16_le(s, 1); |
out_uint16_le(s, 1); |
460 |
|
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461 |
out_uint32(s, 0); |
out_uint32(s, 0); |
462 |
out_uint8(s, server_bpp); |
out_uint8(s, g_server_bpp); |
463 |
out_uint16_le(s, 0x0700); |
out_uint16_le(s, 0x0700); |
464 |
out_uint8(s, 0); |
out_uint8(s, 0); |
465 |
out_uint32_le(s, 1); |
out_uint32_le(s, 1); |
467 |
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468 |
out_uint16_le(s, SEC_TAG_CLI_4); |
out_uint16_le(s, SEC_TAG_CLI_4); |
469 |
out_uint16_le(s, 12); |
out_uint16_le(s, 12); |
470 |
out_uint32_le(s, 9); |
out_uint32_le(s, g_console_session ? 0xb : 9); |
471 |
out_uint32(s, 0); |
out_uint32(s, 0); |
472 |
|
|
473 |
/* Client encryption settings */ |
/* Client encryption settings */ |
474 |
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
475 |
out_uint16_le(s, 12); /* length */ |
out_uint16_le(s, 12); /* length */ |
476 |
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 */ |
477 |
out_uint32(s, 0); /* Unknown */ |
out_uint32(s, 0); /* Unknown */ |
478 |
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|
479 |
DEBUG_RDP5(("g_num_channels is %d\n", g_num_channels)); |
DEBUG_RDP5(("g_num_channels is %d\n", g_num_channels)); |
617 |
} |
} |
618 |
else |
else |
619 |
{ |
{ |
620 |
|
uint32 certcount; |
621 |
|
|
622 |
DEBUG_RDP5(("We're going for the RDP5-style encryption\n")); |
DEBUG_RDP5(("We're going for the RDP5-style encryption\n")); |
623 |
in_uint8s(s, 4); /* Number of certificates */ |
in_uint32_le(s, certcount); /* Number of certificates */ |
624 |
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|
625 |
|
if (certcount < 2) |
626 |
|
{ |
627 |
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error("Server didn't send enough X509 certificates\n"); |
628 |
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return False; |
629 |
|
} |
630 |
|
|
631 |
|
for (; certcount > 2; certcount--) |
632 |
|
{ /* ignore all the certificates between the root and the signing CA */ |
633 |
|
uint32 ignorelen; |
634 |
|
X509 *ignorecert; |
635 |
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|
636 |
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DEBUG_RDP5(("Ignored certs left: %d\n", certcount)); |
637 |
|
|
638 |
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in_uint32_le(s, ignorelen); |
639 |
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DEBUG_RDP5(("Ignored Certificate length is %d\n", ignorelen)); |
640 |
|
ignorecert = d2i_X509(NULL, &(s->p), ignorelen); |
641 |
|
|
642 |
|
if (ignorecert == NULL) |
643 |
|
{ /* XXX: error out? */ |
644 |
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DEBUG_RDP5(("got a bad cert: this will probably screw up the rest of the communication\n")); |
645 |
|
} |
646 |
|
|
647 |
|
#ifdef WITH_DEBUG_RDP5 |
648 |
|
DEBUG_RDP5(("cert #%d (ignored):\n", certcount)); |
649 |
|
X509_print_fp(stdout, ignorecert); |
650 |
|
#endif |
651 |
|
} |
652 |
|
|
653 |
/* Do da funky X.509 stuffy |
/* Do da funky X.509 stuffy |
654 |
|
|
722 |
|
|
723 |
DEBUG(("Generating client random\n")); |
DEBUG(("Generating client random\n")); |
724 |
/* Generate a client random, and hence determine encryption keys */ |
/* Generate a client random, and hence determine encryption keys */ |
725 |
// This is what the MS client do: |
/* This is what the MS client do: */ |
726 |
memset(inr, 0, SEC_RANDOM_SIZE); |
memset(inr, 0, SEC_RANDOM_SIZE); |
727 |
/* *ARIGL!* Plaintext attack, anyone? |
/* *ARIGL!* Plaintext attack, anyone? |
728 |
I tried doing: |
I tried doing: |
759 |
static void |
static void |
760 |
sec_process_srv_info(STREAM s) |
sec_process_srv_info(STREAM s) |
761 |
{ |
{ |
762 |
in_uint16_le(s, server_rdp_version); |
in_uint16_le(s, g_server_rdp_version); |
763 |
DEBUG_RDP5(("Server RDP version is %d\n", server_rdp_version)); |
DEBUG_RDP5(("Server RDP version is %d\n", g_server_rdp_version)); |
764 |
if (1 == server_rdp_version) |
if (1 == g_server_rdp_version) |
765 |
use_rdp5 = 0; |
{ |
766 |
|
g_use_rdp5 = 0; |
767 |
|
g_server_bpp = 8; |
768 |
|
} |
769 |
} |
} |
770 |
|
|
771 |
|
|
777 |
uint8 *next_tag; |
uint8 *next_tag; |
778 |
uint8 len; |
uint8 len; |
779 |
|
|
780 |
in_uint8s(s, 21); /* header (T.124 stuff, probably) */ |
in_uint8s(s, 21); /* header (T.124 ConferenceCreateResponse) */ |
781 |
in_uint8(s, len); |
in_uint8(s, len); |
782 |
if (len & 0x80) |
if (len & 0x80) |
783 |
in_uint8(s, len); |
in_uint8(s, len); |
805 |
case SEC_TAG_SRV_CHANNELS: |
case SEC_TAG_SRV_CHANNELS: |
806 |
/* FIXME: We should parse this information and |
/* FIXME: We should parse this information and |
807 |
use it to map RDP5 channels to MCS |
use it to map RDP5 channels to MCS |
808 |
channels */ |
channels */ |
809 |
break; |
break; |
810 |
|
|
811 |
default: |
default: |
818 |
|
|
819 |
/* Receive secure transport packet */ |
/* Receive secure transport packet */ |
820 |
STREAM |
STREAM |
821 |
sec_recv(void) |
sec_recv(uint8 * rdpver) |
822 |
{ |
{ |
823 |
uint32 sec_flags; |
uint32 sec_flags; |
824 |
uint16 channel; |
uint16 channel; |
825 |
STREAM s; |
STREAM s; |
826 |
|
|
827 |
while ((s = mcs_recv(&channel)) != NULL) |
while ((s = mcs_recv(&channel, rdpver)) != NULL) |
828 |
{ |
{ |
829 |
if (encryption || !g_licence_issued) |
if (rdpver != NULL) |
830 |
|
{ |
831 |
|
if (*rdpver != 3) |
832 |
|
{ |
833 |
|
if (*rdpver & 0x80) |
834 |
|
{ |
835 |
|
in_uint8s(s, 8); /* signature */ |
836 |
|
sec_decrypt(s->p, s->end - s->p); |
837 |
|
} |
838 |
|
return s; |
839 |
|
} |
840 |
|
} |
841 |
|
if (g_encryption || !g_licence_issued) |
842 |
{ |
{ |
843 |
in_uint32_le(s, sec_flags); |
in_uint32_le(s, sec_flags); |
844 |
|
|
858 |
if (channel != MCS_GLOBAL_CHANNEL) |
if (channel != MCS_GLOBAL_CHANNEL) |
859 |
{ |
{ |
860 |
channel_process(s, channel); |
channel_process(s, channel); |
861 |
continue; |
*rdpver = 0xff; |
862 |
|
return s; |
863 |
} |
} |
864 |
|
|
865 |
return s; |
return s; |
882 |
if (!mcs_connect(server, &mcs_data, username)) |
if (!mcs_connect(server, &mcs_data, username)) |
883 |
return False; |
return False; |
884 |
|
|
885 |
// sec_process_mcs_data(&mcs_data); |
/* sec_process_mcs_data(&mcs_data); */ |
886 |
if (encryption) |
if (g_encryption) |
887 |
sec_establish_key(); |
sec_establish_key(); |
888 |
xfree(mcs_data.data); |
xfree(mcs_data.data); |
889 |
return True; |
return True; |