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 1999-2002 |
Copyright (C) Matthew Chapman 1999-2002 |
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 |
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extern BOOL g_console_session; |
44 |
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extern int g_server_bpp; |
45 |
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extern uint16 mcs_userid; |
46 |
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extern VCHANNEL g_channels[]; |
47 |
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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 |
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uint16 g_server_rdp_version = 0; |
62 |
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|
63 |
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/* |
64 |
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* I believe this is based on SSLv3 with the following differences: |
65 |
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* MAC algorithm (5.2.3.1) uses only 32-bit length in place of seq_num/type/length fields |
66 |
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* MAC algorithm uses SHA1 and MD5 for the two hash functions instead of one or other |
67 |
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* key_block algorithm (6.2.2) uses 'X', 'YY', 'ZZZ' instead of 'A', 'BB', 'CCC' |
68 |
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* key_block partitioning is different (16 bytes each: MAC secret, decrypt key, encrypt key) |
69 |
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* encryption/decryption keys updated every 4096 packets |
70 |
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* See http://wp.netscape.com/eng/ssl3/draft302.txt |
71 |
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*/ |
72 |
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|
73 |
/* |
/* |
74 |
* 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). |
|
* a client and server salt) and a global salt value used for padding. |
|
75 |
* Both SHA1 and MD5 algorithms are used. |
* Both SHA1 and MD5 algorithms are used. |
76 |
*/ |
*/ |
77 |
void |
void |
102 |
} |
} |
103 |
|
|
104 |
/* |
/* |
105 |
* Weaker 16-byte transformation, also using two 32-byte salts, but |
* 16-byte transformation used to generate export keys (6.2.2). |
|
* only using a single round of MD5. |
|
106 |
*/ |
*/ |
107 |
void |
void |
108 |
sec_hash_16(uint8 * out, uint8 * in, uint8 * salt1, uint8 * salt2) |
sec_hash_16(uint8 * out, uint8 * in, uint8 * salt1, uint8 * salt2) |
125 |
key[2] = 0x9e; |
key[2] = 0x9e; |
126 |
} |
} |
127 |
|
|
128 |
/* Generate a session key and RC4 keys, given client and server randoms */ |
/* Generate encryption keys given client and server randoms */ |
129 |
static void |
static void |
130 |
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) |
131 |
{ |
{ |
132 |
uint8 session_key[48]; |
uint8 pre_master_secret[48]; |
133 |
uint8 temp_hash[48]; |
uint8 master_secret[48]; |
134 |
uint8 input[48]; |
uint8 key_block[48]; |
135 |
|
|
136 |
/* Construct input data to hash */ |
/* Construct pre-master secret */ |
137 |
memcpy(input, client_key, 24); |
memcpy(pre_master_secret, client_random, 24); |
138 |
memcpy(input + 24, server_key, 24); |
memcpy(pre_master_secret + 24, server_random, 24); |
139 |
|
|
140 |
/* Generate session key - two rounds of sec_hash_48 */ |
/* Generate master secret and then key material */ |
141 |
sec_hash_48(temp_hash, input, client_key, server_key, 65); |
sec_hash_48(master_secret, pre_master_secret, client_random, server_random, 'A'); |
142 |
sec_hash_48(session_key, temp_hash, client_key, server_key, 88); |
sec_hash_48(key_block, master_secret, client_random, server_random, 'X'); |
143 |
|
|
144 |
/* Store first 16 bytes of session key, for generating signatures */ |
/* First 16 bytes of key material is MAC secret */ |
145 |
memcpy(sec_sign_key, session_key, 16); |
memcpy(sec_sign_key, key_block, 16); |
146 |
|
|
147 |
/* Generate RC4 keys */ |
/* Generate export keys from next two blocks of 16 bytes */ |
148 |
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); |
149 |
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); |
150 |
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|
151 |
if (rc4_key_size == 1) |
if (rc4_key_size == 1) |
152 |
{ |
{ |
158 |
} |
} |
159 |
else |
else |
160 |
{ |
{ |
161 |
DEBUG(("128-bit encryption enabled\n")); |
DEBUG(("rc_4_key_size == %d, 128-bit encryption enabled\n", rc4_key_size)); |
162 |
rc4_key_len = 16; |
rc4_key_len = 16; |
163 |
} |
} |
164 |
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|
195 |
buffer[3] = (value >> 24) & 0xff; |
buffer[3] = (value >> 24) & 0xff; |
196 |
} |
} |
197 |
|
|
198 |
/* 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 */ |
199 |
void |
void |
200 |
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) |
201 |
{ |
{ |
223 |
memcpy(signature, md5sig, siglen); |
memcpy(signature, md5sig, siglen); |
224 |
} |
} |
225 |
|
|
226 |
/* Update an encryption key - similar to the signing process */ |
/* Update an encryption key */ |
227 |
static void |
static void |
228 |
sec_update(uint8 * key, uint8 * update_key) |
sec_update(uint8 * key, uint8 * update_key) |
229 |
{ |
{ |
269 |
} |
} |
270 |
|
|
271 |
/* Decrypt data using RC4 */ |
/* Decrypt data using RC4 */ |
272 |
static void |
void |
273 |
sec_decrypt(uint8 * data, int length) |
sec_decrypt(uint8 * data, int length) |
274 |
{ |
{ |
275 |
static int use_count; |
static int use_count; |
303 |
static void |
static void |
304 |
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) |
305 |
{ |
{ |
306 |
BN_CTX ctx; |
BN_CTX *ctx; |
307 |
BIGNUM mod, exp, x, y; |
BIGNUM mod, exp, x, y; |
308 |
uint8 inr[SEC_MODULUS_SIZE]; |
uint8 inr[SEC_MODULUS_SIZE]; |
309 |
int outlen; |
int outlen; |
313 |
memcpy(inr, in, len); |
memcpy(inr, in, len); |
314 |
reverse(inr, len); |
reverse(inr, len); |
315 |
|
|
316 |
BN_CTX_init(&ctx); |
ctx = BN_CTX_new(); |
317 |
BN_init(&mod); |
BN_init(&mod); |
318 |
BN_init(&exp); |
BN_init(&exp); |
319 |
BN_init(&x); |
BN_init(&x); |
322 |
BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod); |
BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod); |
323 |
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp); |
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp); |
324 |
BN_bin2bn(inr, len, &x); |
BN_bin2bn(inr, len, &x); |
325 |
BN_mod_exp(&y, &x, &exp, &mod, &ctx); |
BN_mod_exp(&y, &x, &exp, &mod, ctx); |
326 |
outlen = BN_bn2bin(&y, out); |
outlen = BN_bn2bin(&y, out); |
327 |
reverse(out, outlen); |
reverse(out, outlen); |
328 |
if (outlen < SEC_MODULUS_SIZE) |
if (outlen < SEC_MODULUS_SIZE) |
332 |
BN_clear_free(&x); |
BN_clear_free(&x); |
333 |
BN_free(&exp); |
BN_free(&exp); |
334 |
BN_free(&mod); |
BN_free(&mod); |
335 |
BN_CTX_free(&ctx); |
BN_CTX_free(ctx); |
336 |
} |
} |
337 |
|
|
338 |
/* Initialise secure transport packet */ |
/* Initialise secure transport packet */ |
342 |
int hdrlen; |
int hdrlen; |
343 |
STREAM s; |
STREAM s; |
344 |
|
|
345 |
if (!licence_issued) |
if (!g_licence_issued) |
346 |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 4; |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 4; |
347 |
else |
else |
348 |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 0; |
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 0; |
352 |
return s; |
return s; |
353 |
} |
} |
354 |
|
|
355 |
/* Transmit secure transport packet */ |
/* Transmit secure transport packet over specified channel */ |
356 |
void |
void |
357 |
sec_send(STREAM s, uint32 flags) |
sec_send_to_channel(STREAM s, uint32 flags, uint16 channel) |
358 |
{ |
{ |
359 |
int datalen; |
int datalen; |
360 |
|
|
361 |
s_pop_layer(s, sec_hdr); |
s_pop_layer(s, sec_hdr); |
362 |
if (!licence_issued || (flags & SEC_ENCRYPT)) |
if (!g_licence_issued || (flags & SEC_ENCRYPT)) |
363 |
out_uint32_le(s, flags); |
out_uint32_le(s, flags); |
364 |
|
|
365 |
if (flags & SEC_ENCRYPT) |
if (flags & SEC_ENCRYPT) |
376 |
sec_encrypt(s->p + 8, datalen); |
sec_encrypt(s->p + 8, datalen); |
377 |
} |
} |
378 |
|
|
379 |
mcs_send(s); |
mcs_send_to_channel(s, channel); |
380 |
} |
} |
381 |
|
|
382 |
|
/* Transmit secure transport packet */ |
383 |
|
|
384 |
|
void |
385 |
|
sec_send(STREAM s, uint32 flags) |
386 |
|
{ |
387 |
|
sec_send_to_channel(s, flags, MCS_GLOBAL_CHANNEL); |
388 |
|
} |
389 |
|
|
390 |
|
|
391 |
/* Transfer the client random to the server */ |
/* Transfer the client random to the server */ |
392 |
static void |
static void |
393 |
sec_establish_key(void) |
sec_establish_key(void) |
411 |
sec_out_mcs_data(STREAM s) |
sec_out_mcs_data(STREAM s) |
412 |
{ |
{ |
413 |
int hostlen = 2 * strlen(hostname); |
int hostlen = 2 * strlen(hostname); |
414 |
|
int length = 158 + 76 + 12 + 4; |
415 |
|
unsigned int i; |
416 |
|
|
417 |
|
if (g_num_channels > 0) |
418 |
|
length += g_num_channels * 12 + 8; |
419 |
|
|
420 |
if (hostlen > 30) |
if (hostlen > 30) |
421 |
hostlen = 30; |
hostlen = 30; |
422 |
|
|
423 |
out_uint16_be(s, 5); /* unknown */ |
/* Generic Conference Control (T.124) ConferenceCreateRequest */ |
424 |
|
out_uint16_be(s, 5); |
425 |
out_uint16_be(s, 0x14); |
out_uint16_be(s, 0x14); |
426 |
out_uint8(s, 0x7c); |
out_uint8(s, 0x7c); |
427 |
out_uint16_be(s, 1); |
out_uint16_be(s, 1); |
428 |
|
|
429 |
out_uint16_be(s, (158 | 0x8000)); /* remaining length */ |
out_uint16_be(s, (length | 0x8000)); /* remaining length */ |
430 |
|
|
431 |
out_uint16_be(s, 8); /* length? */ |
out_uint16_be(s, 8); /* length? */ |
432 |
out_uint16_be(s, 16); |
out_uint16_be(s, 16); |
434 |
out_uint16_le(s, 0xc001); |
out_uint16_le(s, 0xc001); |
435 |
out_uint8(s, 0); |
out_uint8(s, 0); |
436 |
|
|
437 |
out_uint32_le(s, 0x61637544); /* "Duca" ?! */ |
out_uint32_le(s, 0x61637544); /* OEM ID: "Duca", as in Ducati. */ |
438 |
out_uint16_be(s, (144 | 0x8000)); /* remaining length */ |
out_uint16_be(s, ((length - 14) | 0x8000)); /* remaining length */ |
439 |
|
|
440 |
/* Client information */ |
/* Client information */ |
441 |
out_uint16_le(s, SEC_TAG_CLI_INFO); |
out_uint16_le(s, SEC_TAG_CLI_INFO); |
442 |
out_uint16_le(s, 136); /* length */ |
out_uint16_le(s, 212); /* length */ |
443 |
out_uint16_le(s, 1); |
out_uint16_le(s, g_use_rdp5 ? 4 : 1); /* RDP version. 1 == RDP4, 4 == RDP5. */ |
444 |
out_uint16_le(s, 8); |
out_uint16_le(s, 8); |
445 |
out_uint16_le(s, width); |
out_uint16_le(s, g_width); |
446 |
out_uint16_le(s, height); |
out_uint16_le(s, g_height); |
447 |
out_uint16_le(s, 0xca01); |
out_uint16_le(s, 0xca01); |
448 |
out_uint16_le(s, 0xaa03); |
out_uint16_le(s, 0xaa03); |
449 |
out_uint32_le(s, keylayout); |
out_uint32_le(s, keylayout); |
450 |
out_uint32_le(s, 419); /* client build? we are 419 compatible :-) */ |
out_uint32_le(s, 2600); /* Client build. We are now 2600 compatible :-) */ |
451 |
|
|
452 |
/* Unicode name of client, padded to 32 bytes */ |
/* Unicode name of client, padded to 32 bytes */ |
453 |
rdp_out_unistr(s, hostname, hostlen); |
rdp_out_unistr(s, hostname, hostlen); |
457 |
out_uint32(s, 0); |
out_uint32(s, 0); |
458 |
out_uint32_le(s, 12); |
out_uint32_le(s, 12); |
459 |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
460 |
|
out_uint16_le(s, 0xca01); /* colour depth? */ |
461 |
|
out_uint16_le(s, 1); |
462 |
|
|
463 |
out_uint16_le(s, 0xca01); |
out_uint32(s, 0); |
464 |
out_uint16(s, 0); |
out_uint8(s, g_server_bpp); |
465 |
|
out_uint16_le(s, 0x0700); |
466 |
|
out_uint8(s, 0); |
467 |
|
out_uint32_le(s, 1); |
468 |
|
out_uint8s(s, 64); /* End of client info */ |
469 |
|
|
470 |
|
out_uint16_le(s, SEC_TAG_CLI_4); |
471 |
|
out_uint16_le(s, 12); |
472 |
|
out_uint32_le(s, g_console_session ? 0xb : 9); |
473 |
|
out_uint32(s, 0); |
474 |
|
|
475 |
/* Client encryption settings */ |
/* Client encryption settings */ |
476 |
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
477 |
out_uint16_le(s, 8); /* length */ |
out_uint16_le(s, 12); /* length */ |
478 |
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 */ |
479 |
|
out_uint32(s, 0); /* Unknown */ |
480 |
|
|
481 |
|
DEBUG_RDP5(("g_num_channels is %d\n", g_num_channels)); |
482 |
|
if (g_num_channels > 0) |
483 |
|
{ |
484 |
|
out_uint16_le(s, SEC_TAG_CLI_CHANNELS); |
485 |
|
out_uint16_le(s, g_num_channels * 12 + 8); /* length */ |
486 |
|
out_uint32_le(s, g_num_channels); /* number of virtual channels */ |
487 |
|
for (i = 0; i < g_num_channels; i++) |
488 |
|
{ |
489 |
|
DEBUG_RDP5(("Requesting channel %s\n", g_channels[i].name)); |
490 |
|
out_uint8a(s, g_channels[i].name, 8); |
491 |
|
out_uint32_be(s, g_channels[i].flags); |
492 |
|
} |
493 |
|
} |
494 |
|
|
495 |
s_mark_end(s); |
s_mark_end(s); |
496 |
} |
} |
497 |
|
|
523 |
return s_check(s); |
return s_check(s); |
524 |
} |
} |
525 |
|
|
526 |
|
static BOOL |
527 |
|
sec_parse_x509_key(X509 * cert) |
528 |
|
{ |
529 |
|
EVP_PKEY *epk = NULL; |
530 |
|
/* By some reason, Microsoft sets the OID of the Public RSA key to |
531 |
|
the oid for "MD5 with RSA Encryption" instead of "RSA Encryption" |
532 |
|
|
533 |
|
Kudos to Richard Levitte for the following (. intiutive .) |
534 |
|
lines of code that resets the OID and let's us extract the key. */ |
535 |
|
if (OBJ_obj2nid(cert->cert_info->key->algor->algorithm) == NID_md5WithRSAEncryption) |
536 |
|
{ |
537 |
|
DEBUG_RDP5(("Re-setting algorithm type to RSA in server certificate\n")); |
538 |
|
cert->cert_info->key->algor->algorithm = OBJ_nid2obj(NID_rsaEncryption); |
539 |
|
} |
540 |
|
epk = X509_get_pubkey(cert); |
541 |
|
if (NULL == epk) |
542 |
|
{ |
543 |
|
error("Failed to extract public key from certificate\n"); |
544 |
|
return False; |
545 |
|
} |
546 |
|
|
547 |
|
server_public_key = (RSA *) epk->pkey.ptr; |
548 |
|
|
549 |
|
return True; |
550 |
|
} |
551 |
|
|
552 |
|
|
553 |
/* Parse a crypto information structure */ |
/* Parse a crypto information structure */ |
554 |
static BOOL |
static BOOL |
555 |
sec_parse_crypt_info(STREAM s, uint32 * rc4_key_size, |
sec_parse_crypt_info(STREAM s, uint32 * rc4_key_size, |
556 |
uint8 ** server_random, uint8 ** modulus, uint8 ** exponent) |
uint8 ** server_random, uint8 ** modulus, uint8 ** exponent) |
557 |
{ |
{ |
558 |
uint32 crypt_level, random_len, rsa_info_len; |
uint32 crypt_level, random_len, rsa_info_len; |
559 |
|
uint32 cacert_len, cert_len, flags; |
560 |
|
X509 *cacert, *server_cert; |
561 |
uint16 tag, length; |
uint16 tag, length; |
562 |
uint8 *next_tag, *end; |
uint8 *next_tag, *end; |
563 |
|
|
564 |
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 */ |
565 |
in_uint32_le(s, crypt_level); /* 1 = low, 2 = medium, 3 = high */ |
in_uint32_le(s, crypt_level); /* 1 = low, 2 = medium, 3 = high */ |
566 |
if (crypt_level == 0) /* no encryptation */ |
if (crypt_level == 0) /* no encryption */ |
567 |
return False; |
return False; |
568 |
in_uint32_le(s, random_len); |
in_uint32_le(s, random_len); |
569 |
in_uint32_le(s, rsa_info_len); |
in_uint32_le(s, rsa_info_len); |
570 |
|
|
571 |
if (random_len != SEC_RANDOM_SIZE) |
if (random_len != SEC_RANDOM_SIZE) |
572 |
{ |
{ |
573 |
error("random len %d\n", random_len); |
error("random len %d, expected %d\n", random_len, SEC_RANDOM_SIZE); |
574 |
return False; |
return False; |
575 |
} |
} |
576 |
|
|
581 |
if (end > s->end) |
if (end > s->end) |
582 |
return False; |
return False; |
583 |
|
|
584 |
in_uint8s(s, 12); /* unknown */ |
in_uint32_le(s, flags); /* 1 = RDP4-style, 0x80000002 = X.509 */ |
585 |
|
if (flags & 1) |
586 |
|
{ |
587 |
|
DEBUG_RDP5(("We're going for the RDP4-style encryption\n")); |
588 |
|
in_uint8s(s, 8); /* unknown */ |
589 |
|
|
590 |
|
while (s->p < end) |
591 |
|
{ |
592 |
|
in_uint16_le(s, tag); |
593 |
|
in_uint16_le(s, length); |
594 |
|
|
595 |
|
next_tag = s->p + length; |
596 |
|
|
597 |
while (s->p < end) |
switch (tag) |
598 |
|
{ |
599 |
|
case SEC_TAG_PUBKEY: |
600 |
|
if (!sec_parse_public_key(s, modulus, exponent)) |
601 |
|
return False; |
602 |
|
DEBUG_RDP5(("Got Public key, RDP4-style\n")); |
603 |
|
|
604 |
|
break; |
605 |
|
|
606 |
|
case SEC_TAG_KEYSIG: |
607 |
|
/* Is this a Microsoft key that we just got? */ |
608 |
|
/* Care factor: zero! */ |
609 |
|
/* Actually, it would probably be a good idea to check if the public key is signed with this key, and then store this |
610 |
|
key as a known key of the hostname. This would prevent some MITM-attacks. */ |
611 |
|
break; |
612 |
|
|
613 |
|
default: |
614 |
|
unimpl("crypt tag 0x%x\n", tag); |
615 |
|
} |
616 |
|
|
617 |
|
s->p = next_tag; |
618 |
|
} |
619 |
|
} |
620 |
|
else |
621 |
{ |
{ |
622 |
in_uint16_le(s, tag); |
uint32 certcount; |
|
in_uint16_le(s, length); |
|
623 |
|
|
624 |
next_tag = s->p + length; |
DEBUG_RDP5(("We're going for the RDP5-style encryption\n")); |
625 |
|
in_uint32_le(s, certcount); /* Number of certificates */ |
626 |
|
|
627 |
switch (tag) |
if (certcount < 2) |
628 |
{ |
{ |
629 |
case SEC_TAG_PUBKEY: |
error("Server didn't send enough X509 certificates\n"); |
630 |
if (!sec_parse_public_key(s, modulus, exponent)) |
return False; |
631 |
return False; |
} |
632 |
|
|
633 |
break; |
for (; certcount > 2; certcount--) |
634 |
|
{ /* ignore all the certificates between the root and the signing CA */ |
635 |
|
uint32 ignorelen; |
636 |
|
X509 *ignorecert; |
637 |
|
|
638 |
|
DEBUG_RDP5(("Ignored certs left: %d\n", certcount)); |
639 |
|
|
640 |
|
in_uint32_le(s, ignorelen); |
641 |
|
DEBUG_RDP5(("Ignored Certificate length is %d\n", ignorelen)); |
642 |
|
ignorecert = d2i_X509(NULL, &(s->p), ignorelen); |
643 |
|
|
644 |
|
if (ignorecert == NULL) |
645 |
|
{ /* XXX: error out? */ |
646 |
|
DEBUG_RDP5(("got a bad cert: this will probably screw up the rest of the communication\n")); |
647 |
|
} |
648 |
|
|
649 |
case SEC_TAG_KEYSIG: |
#ifdef WITH_DEBUG_RDP5 |
650 |
/* Is this a Microsoft key that we just got? */ |
DEBUG_RDP5(("cert #%d (ignored):\n", certcount)); |
651 |
/* Care factor: zero! */ |
X509_print_fp(stdout, ignorecert); |
652 |
break; |
#endif |
653 |
|
} |
654 |
|
|
655 |
default: |
/* Do da funky X.509 stuffy |
656 |
unimpl("crypt tag 0x%x\n", tag); |
|
657 |
|
"How did I find out about this? I looked up and saw a |
658 |
|
bright light and when I came to I had a scar on my forehead |
659 |
|
and knew about X.500" |
660 |
|
- Peter Gutman in a early version of |
661 |
|
http://www.cs.auckland.ac.nz/~pgut001/pubs/x509guide.txt |
662 |
|
*/ |
663 |
|
|
664 |
|
in_uint32_le(s, cacert_len); |
665 |
|
DEBUG_RDP5(("CA Certificate length is %d\n", cacert_len)); |
666 |
|
cacert = d2i_X509(NULL, &(s->p), cacert_len); |
667 |
|
/* Note: We don't need to move s->p here - d2i_X509 is |
668 |
|
"kind" enough to do it for us */ |
669 |
|
if (NULL == cacert) |
670 |
|
{ |
671 |
|
error("Couldn't load CA Certificate from server\n"); |
672 |
|
return False; |
673 |
} |
} |
674 |
|
|
675 |
s->p = next_tag; |
/* Currently, we don't use the CA Certificate. |
676 |
} |
FIXME: |
677 |
|
*) Verify the server certificate (server_cert) with the |
678 |
|
CA certificate. |
679 |
|
*) Store the CA Certificate with the hostname of the |
680 |
|
server we are connecting to as key, and compare it |
681 |
|
when we connect the next time, in order to prevent |
682 |
|
MITM-attacks. |
683 |
|
*/ |
684 |
|
|
685 |
|
in_uint32_le(s, cert_len); |
686 |
|
DEBUG_RDP5(("Certificate length is %d\n", cert_len)); |
687 |
|
server_cert = d2i_X509(NULL, &(s->p), cert_len); |
688 |
|
if (NULL == server_cert) |
689 |
|
{ |
690 |
|
error("Couldn't load Certificate from server\n"); |
691 |
|
return False; |
692 |
|
} |
693 |
|
|
694 |
|
in_uint8s(s, 16); /* Padding */ |
695 |
|
|
696 |
|
/* Note: Verifying the server certificate must be done here, |
697 |
|
before sec_parse_public_key since we'll have to apply |
698 |
|
serious violence to the key after this */ |
699 |
|
|
700 |
|
if (!sec_parse_x509_key(server_cert)) |
701 |
|
{ |
702 |
|
DEBUG_RDP5(("Didn't parse X509 correctly\n")); |
703 |
|
return False; |
704 |
|
} |
705 |
|
return True; /* There's some garbage here we don't care about */ |
706 |
|
} |
707 |
return s_check_end(s); |
return s_check_end(s); |
708 |
} |
} |
709 |
|
|
714 |
uint8 *server_random, *modulus, *exponent; |
uint8 *server_random, *modulus, *exponent; |
715 |
uint8 client_random[SEC_RANDOM_SIZE]; |
uint8 client_random[SEC_RANDOM_SIZE]; |
716 |
uint32 rc4_key_size; |
uint32 rc4_key_size; |
717 |
|
uint8 inr[SEC_MODULUS_SIZE]; |
718 |
|
|
719 |
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)) |
720 |
|
{ |
721 |
|
DEBUG(("Failed to parse crypt info\n")); |
722 |
return; |
return; |
723 |
|
} |
724 |
|
|
725 |
|
DEBUG(("Generating client random\n")); |
726 |
/* Generate a client random, and hence determine encryption keys */ |
/* Generate a client random, and hence determine encryption keys */ |
727 |
|
/* This is what the MS client do: */ |
728 |
|
memset(inr, 0, SEC_RANDOM_SIZE); |
729 |
|
/* *ARIGL!* Plaintext attack, anyone? |
730 |
|
I tried doing: |
731 |
|
generate_random(inr); |
732 |
|
..but that generates connection errors now and then (yes, |
733 |
|
"now and then". Something like 0 to 3 attempts needed before a |
734 |
|
successful connection. Nice. Not! |
735 |
|
*/ |
736 |
|
|
737 |
generate_random(client_random); |
generate_random(client_random); |
738 |
sec_rsa_encrypt(sec_crypted_random, client_random, SEC_RANDOM_SIZE, modulus, exponent); |
if (NULL != server_public_key) |
739 |
|
{ /* Which means we should use |
740 |
|
RDP5-style encryption */ |
741 |
|
|
742 |
|
memcpy(inr + SEC_RANDOM_SIZE, client_random, SEC_RANDOM_SIZE); |
743 |
|
reverse(inr + SEC_RANDOM_SIZE, SEC_RANDOM_SIZE); |
744 |
|
|
745 |
|
RSA_public_encrypt(SEC_MODULUS_SIZE, |
746 |
|
inr, sec_crypted_random, server_public_key, RSA_NO_PADDING); |
747 |
|
|
748 |
|
reverse(sec_crypted_random, SEC_MODULUS_SIZE); |
749 |
|
|
750 |
|
} |
751 |
|
else |
752 |
|
{ /* RDP4-style encryption */ |
753 |
|
sec_rsa_encrypt(sec_crypted_random, |
754 |
|
client_random, SEC_RANDOM_SIZE, modulus, exponent); |
755 |
|
} |
756 |
sec_generate_keys(client_random, server_random, rc4_key_size); |
sec_generate_keys(client_random, server_random, rc4_key_size); |
757 |
} |
} |
758 |
|
|
759 |
/* Process connect response data blob */ |
|
760 |
|
/* Process SRV_INFO, find RDP version supported by server */ |
761 |
static void |
static void |
762 |
|
sec_process_srv_info(STREAM s) |
763 |
|
{ |
764 |
|
in_uint16_le(s, g_server_rdp_version); |
765 |
|
DEBUG_RDP5(("Server RDP version is %d\n", g_server_rdp_version)); |
766 |
|
if (1 == g_server_rdp_version) |
767 |
|
{ |
768 |
|
g_use_rdp5 = 0; |
769 |
|
g_server_bpp = 8; |
770 |
|
} |
771 |
|
} |
772 |
|
|
773 |
|
|
774 |
|
/* Process connect response data blob */ |
775 |
|
void |
776 |
sec_process_mcs_data(STREAM s) |
sec_process_mcs_data(STREAM s) |
777 |
{ |
{ |
778 |
uint16 tag, length; |
uint16 tag, length; |
779 |
uint8 *next_tag; |
uint8 *next_tag; |
780 |
uint8 len; |
uint8 len; |
781 |
|
|
782 |
in_uint8s(s, 21); /* header */ |
in_uint8s(s, 21); /* header (T.124 ConferenceCreateResponse) */ |
783 |
in_uint8(s, len); |
in_uint8(s, len); |
784 |
if (len & 0x80) |
if (len & 0x80) |
785 |
in_uint8(s, len); |
in_uint8(s, len); |
797 |
switch (tag) |
switch (tag) |
798 |
{ |
{ |
799 |
case SEC_TAG_SRV_INFO: |
case SEC_TAG_SRV_INFO: |
800 |
case SEC_TAG_SRV_3: |
sec_process_srv_info(s); |
801 |
break; |
break; |
802 |
|
|
803 |
case SEC_TAG_SRV_CRYPT: |
case SEC_TAG_SRV_CRYPT: |
804 |
sec_process_crypt_info(s); |
sec_process_crypt_info(s); |
805 |
break; |
break; |
806 |
|
|
807 |
|
case SEC_TAG_SRV_CHANNELS: |
808 |
|
/* FIXME: We should parse this information and |
809 |
|
use it to map RDP5 channels to MCS |
810 |
|
channels */ |
811 |
|
break; |
812 |
|
|
813 |
default: |
default: |
814 |
unimpl("response tag 0x%x\n", tag); |
unimpl("response tag 0x%x\n", tag); |
815 |
} |
} |
823 |
sec_recv(void) |
sec_recv(void) |
824 |
{ |
{ |
825 |
uint32 sec_flags; |
uint32 sec_flags; |
826 |
|
uint16 channel; |
827 |
STREAM s; |
STREAM s; |
828 |
|
|
829 |
while ((s = mcs_recv()) != NULL) |
while ((s = mcs_recv(&channel)) != NULL) |
830 |
{ |
{ |
831 |
if (encryption || !licence_issued) |
if (g_encryption || !g_licence_issued) |
832 |
{ |
{ |
833 |
in_uint32_le(s, sec_flags); |
in_uint32_le(s, sec_flags); |
834 |
|
|
835 |
|
if (sec_flags & SEC_ENCRYPT) |
836 |
|
{ |
837 |
|
in_uint8s(s, 8); /* signature */ |
838 |
|
sec_decrypt(s->p, s->end - s->p); |
839 |
|
} |
840 |
|
|
841 |
if (sec_flags & SEC_LICENCE_NEG) |
if (sec_flags & SEC_LICENCE_NEG) |
842 |
{ |
{ |
843 |
licence_process(s); |
licence_process(s); |
844 |
continue; |
continue; |
845 |
} |
} |
846 |
|
} |
847 |
|
|
848 |
if (sec_flags & SEC_ENCRYPT) |
if (channel != MCS_GLOBAL_CHANNEL) |
849 |
{ |
{ |
850 |
in_uint8s(s, 8); /* signature */ |
channel_process(s, channel); |
851 |
sec_decrypt(s->p, s->end - s->p); |
continue; |
|
} |
|
852 |
} |
} |
853 |
|
|
854 |
return s; |
return s; |
859 |
|
|
860 |
/* Establish a secure connection */ |
/* Establish a secure connection */ |
861 |
BOOL |
BOOL |
862 |
sec_connect(char *server) |
sec_connect(char *server, char *username) |
863 |
{ |
{ |
864 |
struct stream mcs_data; |
struct stream mcs_data; |
865 |
|
|
866 |
/* We exchange some RDP data during the MCS-Connect */ |
/* We exchange some RDP data during the MCS-Connect */ |
867 |
mcs_data.size = 512; |
mcs_data.size = 512; |
868 |
mcs_data.p = mcs_data.data = xmalloc(mcs_data.size); |
mcs_data.p = mcs_data.data = (uint8 *) xmalloc(mcs_data.size); |
869 |
sec_out_mcs_data(&mcs_data); |
sec_out_mcs_data(&mcs_data); |
870 |
|
|
871 |
if (!mcs_connect(server, &mcs_data)) |
if (!mcs_connect(server, &mcs_data, username)) |
872 |
return False; |
return False; |
873 |
|
|
874 |
sec_process_mcs_data(&mcs_data); |
/* sec_process_mcs_data(&mcs_data); */ |
875 |
if (encryption) |
if (g_encryption) |
876 |
sec_establish_key(); |
sec_establish_key(); |
877 |
|
xfree(mcs_data.data); |
878 |
return True; |
return True; |
879 |
} |
} |
880 |
|
|