/**

 * FreeRDP: A Remote Desktop Protocol Implementation

 * RDP Security

 *

 * Copyright 2011 Marc-Andre Moreau <marcandre.moreau@gmail.com>

 * Copyright 2014 Norbert Federa <norbert.federa@thincast.com>

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "security.h"

#include <freerdp/log.h>

#include <winpr/crypto.h>

#define TAG FREERDP_TAG("core")

/* 0x36 repeated 40 times */

static const BYTE pad1[40] = { "\x36\x36\x36\x36\x36\x36\x36\x36"

	                           "\x36\x36\x36\x36\x36\x36\x36\x36"

	                           "\x36\x36\x36\x36\x36\x36\x36\x36"

	                           "\x36\x36\x36\x36\x36\x36\x36\x36"

	                           "\x36\x36\x36\x36\x36\x36\x36\x36" };

/* 0x5C repeated 48 times */

static const BYTE pad2[48] = { "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"

	                           "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"

	                           "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"

	                           "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"

	                           "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C"

	                           "\x5C\x5C\x5C\x5C\x5C\x5C\x5C\x5C" };

static const BYTE fips_reverse_table[256] = {

	0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,

	0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,

	0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,

	0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,

	0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,

	0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,

	0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,

	0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,

	0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,

	0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,

	0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,

	0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,

	0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,

	0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,

	0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,

	0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff

};

static const BYTE fips_oddparity_table[256] = {

	0x01, 0x01, 0x02, 0x02, 0x04, 0x04, 0x07, 0x07, 0x08, 0x08, 0x0b, 0x0b, 0x0d, 0x0d, 0x0e, 0x0e,

	0x10, 0x10, 0x13, 0x13, 0x15, 0x15, 0x16, 0x16, 0x19, 0x19, 0x1a, 0x1a, 0x1c, 0x1c, 0x1f, 0x1f,

	0x20, 0x20, 0x23, 0x23, 0x25, 0x25, 0x26, 0x26, 0x29, 0x29, 0x2a, 0x2a, 0x2c, 0x2c, 0x2f, 0x2f,

	0x31, 0x31, 0x32, 0x32, 0x34, 0x34, 0x37, 0x37, 0x38, 0x38, 0x3b, 0x3b, 0x3d, 0x3d, 0x3e, 0x3e,

	0x40, 0x40, 0x43, 0x43, 0x45, 0x45, 0x46, 0x46, 0x49, 0x49, 0x4a, 0x4a, 0x4c, 0x4c, 0x4f, 0x4f,

	0x51, 0x51, 0x52, 0x52, 0x54, 0x54, 0x57, 0x57, 0x58, 0x58, 0x5b, 0x5b, 0x5d, 0x5d, 0x5e, 0x5e,

	0x61, 0x61, 0x62, 0x62, 0x64, 0x64, 0x67, 0x67, 0x68, 0x68, 0x6b, 0x6b, 0x6d, 0x6d, 0x6e, 0x6e,

	0x70, 0x70, 0x73, 0x73, 0x75, 0x75, 0x76, 0x76, 0x79, 0x79, 0x7a, 0x7a, 0x7c, 0x7c, 0x7f, 0x7f,

	0x80, 0x80, 0x83, 0x83, 0x85, 0x85, 0x86, 0x86, 0x89, 0x89, 0x8a, 0x8a, 0x8c, 0x8c, 0x8f, 0x8f,

	0x91, 0x91, 0x92, 0x92, 0x94, 0x94, 0x97, 0x97, 0x98, 0x98, 0x9b, 0x9b, 0x9d, 0x9d, 0x9e, 0x9e,

	0xa1, 0xa1, 0xa2, 0xa2, 0xa4, 0xa4, 0xa7, 0xa7, 0xa8, 0xa8, 0xab, 0xab, 0xad, 0xad, 0xae, 0xae,

	0xb0, 0xb0, 0xb3, 0xb3, 0xb5, 0xb5, 0xb6, 0xb6, 0xb9, 0xb9, 0xba, 0xba, 0xbc, 0xbc, 0xbf, 0xbf,

	0xc1, 0xc1, 0xc2, 0xc2, 0xc4, 0xc4, 0xc7, 0xc7, 0xc8, 0xc8, 0xcb, 0xcb, 0xcd, 0xcd, 0xce, 0xce,

	0xd0, 0xd0, 0xd3, 0xd3, 0xd5, 0xd5, 0xd6, 0xd6, 0xd9, 0xd9, 0xda, 0xda, 0xdc, 0xdc, 0xdf, 0xdf,

	0xe0, 0xe0, 0xe3, 0xe3, 0xe5, 0xe5, 0xe6, 0xe6, 0xe9, 0xe9, 0xea, 0xea, 0xec, 0xec, 0xef, 0xef,

	0xf1, 0xf1, 0xf2, 0xf2, 0xf4, 0xf4, 0xf7, 0xf7, 0xf8, 0xf8, 0xfb, 0xfb, 0xfd, 0xfd, 0xfe, 0xfe

};

static BOOL security_salted_hash(const BYTE* salt, const BYTE* input, int length, const BYTE* salt1,

                                 const BYTE* salt2, BYTE* output)

{

	WINPR_DIGEST_CTX* sha1 = NULL;

	WINPR_DIGEST_CTX* md5 = NULL;

	BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH];

	BOOL result = FALSE;

	/* SaltedHash(Salt, Input, Salt1, Salt2) = MD5(S + SHA1(Input + Salt + Salt1 + Salt2)) */

	/* SHA1_Digest = SHA1(Input + Salt + Salt1 + Salt2) */

	if (!(sha1 = winpr_Digest_New()))

		goto out;

	if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))

		goto out;

	if (!winpr_Digest_Update(sha1, input, length)) /* Input */

		goto out;

	if (!winpr_Digest_Update(sha1, salt, 48)) /* Salt (48 bytes) */

		goto out;

	if (!winpr_Digest_Update(sha1, salt1, 32)) /* Salt1 (32 bytes) */

		goto out;

	if (!winpr_Digest_Update(sha1, salt2, 32)) /* Salt2 (32 bytes) */

		goto out;

	if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))

		goto out;

	/* SaltedHash(Salt, Input, Salt1, Salt2) = MD5(S + SHA1_Digest) */

	if (!(md5 = winpr_Digest_New()))

		goto out;

	/* Allow FIPS override for use of MD5 here, this is used for creating hashes of the

	 * premaster_secret and master_secret */

	/* used for RDP licensing as described in MS-RDPELE. This is for RDP licensing packets */

	/* which will already be encrypted under FIPS, so the use of MD5 here is not for sensitive data

	 * protection. */

	if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))

		goto out;

	if (!winpr_Digest_Update(md5, salt, 48)) /* Salt (48 bytes) */

		goto out;

	if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */

		goto out;

	if (!winpr_Digest_Final(md5, output, WINPR_MD5_DIGEST_LENGTH))

		goto out;

	result = TRUE;

out:

	winpr_Digest_Free(sha1);

	winpr_Digest_Free(md5);

	return result;

}

static BOOL security_premaster_hash(const char* input, int length, const BYTE* premaster_secret,

                                    const BYTE* client_random, const BYTE* server_random,

                                    BYTE* output)

{

	/* PremasterHash(Input) = SaltedHash(PremasterSecret, Input, ClientRandom, ServerRandom) */

	return security_salted_hash(premaster_secret, (BYTE*)input, length, client_random,

	                            server_random, output);

}

BOOL security_master_secret(const BYTE* premaster_secret, const BYTE* client_random,

                            const BYTE* server_random, BYTE* output)

{

	/* MasterSecret = PremasterHash('A') + PremasterHash('BB') + PremasterHash('CCC') */

	return security_premaster_hash("A", 1, premaster_secret, client_random, server_random,

	                               &output[0]) &&

	       security_premaster_hash("BB", 2, premaster_secret, client_random, server_random,

	                               &output[16]) &&

	       security_premaster_hash("CCC", 3, premaster_secret, client_random, server_random,

	                               &output[32]);

}

static BOOL security_master_hash(const char* input, int length, const BYTE* master_secret,

                                 const BYTE* client_random, const BYTE* server_random, BYTE* output)

{

	/* MasterHash(Input) = SaltedHash(MasterSecret, Input, ServerRandom, ClientRandom) */

	return security_salted_hash(master_secret, (const BYTE*)input, length, server_random,

	                            client_random, output);

}

BOOL security_session_key_blob(const BYTE* master_secret, const BYTE* client_random,

                               const BYTE* server_random, BYTE* output)

{

	/* MasterHash = MasterHash('A') + MasterHash('BB') + MasterHash('CCC') */

	return security_master_hash("A", 1, master_secret, client_random, server_random, &output[0]) &&

	       security_master_hash("BB", 2, master_secret, client_random, server_random,

	                            &output[16]) &&

	       security_master_hash("CCC", 3, master_secret, client_random, server_random, &output[32]);

}

void security_mac_salt_key(const BYTE* session_key_blob, const BYTE* client_random,

                           const BYTE* server_random, BYTE* output)

{

	/* MacSaltKey = First128Bits(SessionKeyBlob) */

	memcpy(output, session_key_blob, 16);

}

static BOOL security_md5_16_32_32(const BYTE* in0, const BYTE* in1, const BYTE* in2, BYTE* output)

{

	WINPR_DIGEST_CTX* md5 = NULL;

	BOOL result = FALSE;

	if (!(md5 = winpr_Digest_New()))

		return FALSE;

	if (!winpr_Digest_Init(md5, WINPR_MD_MD5))

		goto out;

	if (!winpr_Digest_Update(md5, in0, 16))

		goto out;

	if (!winpr_Digest_Update(md5, in1, 32))

		goto out;

	if (!winpr_Digest_Update(md5, in2, 32))

		goto out;

	if (!winpr_Digest_Final(md5, output, WINPR_MD5_DIGEST_LENGTH))

		goto out;

	result = TRUE;

out:

	winpr_Digest_Free(md5);

	return result;

}

static BOOL security_md5_16_32_32_Allow_FIPS(const BYTE* in0, const BYTE* in1, const BYTE* in2,

                                             BYTE* output)

{

	WINPR_DIGEST_CTX* md5 = NULL;

	BOOL result = FALSE;

	if (!(md5 = winpr_Digest_New()))

		return FALSE;

	if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))

		goto out;

	if (!winpr_Digest_Update(md5, in0, 16))

		goto out;

	if (!winpr_Digest_Update(md5, in1, 32))

		goto out;

	if (!winpr_Digest_Update(md5, in2, 32))

		goto out;

	if (!winpr_Digest_Final(md5, output, WINPR_MD5_DIGEST_LENGTH))

		goto out;

	result = TRUE;

out:

	winpr_Digest_Free(md5);

	return result;

}

BOOL security_licensing_encryption_key(const BYTE* session_key_blob, const BYTE* client_random,

                                       const BYTE* server_random, BYTE* output)

{

	/* LicensingEncryptionKey = MD5(Second128Bits(SessionKeyBlob) + ClientRandom + ServerRandom))

	 * Allow FIPS use of MD5 here, this is just used for creating the licensing encryption key as

	 * described in MS-RDPELE. This is for RDP licensing packets which will already be encrypted

	 * under FIPS, so the use of MD5 here is not for sensitive data protection. */

	return security_md5_16_32_32_Allow_FIPS(&session_key_blob[16], client_random, server_random,

	                                        output);

}

static void security_UINT32_le(BYTE* output, UINT32 value)

{

	output[0] = (value)&0xFF;

	output[1] = (value >> 8) & 0xFF;

	output[2] = (value >> 16) & 0xFF;

	output[3] = (value >> 24) & 0xFF;

}

BOOL security_mac_data(const BYTE* mac_salt_key, const BYTE* data, UINT32 length, BYTE* output)

{

	WINPR_DIGEST_CTX* sha1 = NULL;

	WINPR_DIGEST_CTX* md5 = NULL;

	BYTE length_le[4];

	BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH];

	BOOL result = FALSE;

	/* MacData = MD5(MacSaltKey + pad2 + SHA1(MacSaltKey + pad1 + length + data)) */

	security_UINT32_le(length_le, length); /* length must be little-endian */

	/* SHA1_Digest = SHA1(MacSaltKey + pad1 + length + data) */

	if (!(sha1 = winpr_Digest_New()))

		goto out;

	if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))

		goto out;

	if (!winpr_Digest_Update(sha1, mac_salt_key, 16)) /* MacSaltKey */

		goto out;

	if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1))) /* pad1 */

		goto out;

	if (!winpr_Digest_Update(sha1, length_le, sizeof(length_le))) /* length */

		goto out;

	if (!winpr_Digest_Update(sha1, data, length)) /* data */

		goto out;

	if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))

		goto out;

	/* MacData = MD5(MacSaltKey + pad2 + SHA1_Digest) */

	if (!(md5 = winpr_Digest_New()))

		goto out;

	/* Allow FIPS override for use of MD5 here, this is only used for creating the MACData field of

	 * the */

	/* Client Platform Challenge Response packet (from MS-RDPELE section 2.2.2.5). This is for RDP

	 * licensing packets */

	/* which will already be encrypted under FIPS, so the use of MD5 here is not for sensitive data

	 * protection. */

	if (!winpr_Digest_Init_Allow_FIPS(md5, WINPR_MD_MD5))

		goto out;

	if (!winpr_Digest_Update(md5, mac_salt_key, 16)) /* MacSaltKey */

		goto out;

	if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */

		goto out;

	if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */

		goto out;

	if (!winpr_Digest_Final(md5, output, WINPR_MD5_DIGEST_LENGTH))

		goto out;

	result = TRUE;

out:

	winpr_Digest_Free(sha1);

	winpr_Digest_Free(md5);

	return result;

}

BOOL security_mac_signature(rdpRdp* rdp, const BYTE* data, UINT32 length, BYTE* output)

{

	WINPR_DIGEST_CTX* sha1 = NULL;

	WINPR_DIGEST_CTX* md5 = NULL;

	BYTE length_le[4];

	BYTE md5_digest[WINPR_MD5_DIGEST_LENGTH];

	BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH];

	BOOL result = FALSE;

	security_UINT32_le(length_le, length); /* length must be little-endian */

	/* SHA1_Digest = SHA1(MACKeyN + pad1 + length + data) */

	if (!(sha1 = winpr_Digest_New()))

		goto out;

	if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))

		goto out;

	if (!winpr_Digest_Update(sha1, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */

		goto out;

	if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1))) /* pad1 */

		goto out;

	if (!winpr_Digest_Update(sha1, length_le, sizeof(length_le))) /* length */

		goto out;

	if (!winpr_Digest_Update(sha1, data, length)) /* data */

		goto out;

	if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))

		goto out;

	/* MACSignature = First64Bits(MD5(MACKeyN + pad2 + SHA1_Digest)) */

	if (!(md5 = winpr_Digest_New()))

		goto out;

	if (!winpr_Digest_Init(md5, WINPR_MD_MD5))

		goto out;

	if (!winpr_Digest_Update(md5, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */

		goto out;

	if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */

		goto out;

	if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */

		goto out;

	if (!winpr_Digest_Final(md5, md5_digest, sizeof(md5_digest)))

		goto out;

	memcpy(output, md5_digest, 8);

	result = TRUE;

out:

	winpr_Digest_Free(sha1);

	winpr_Digest_Free(md5);

	return result;

}

BOOL security_salted_mac_signature(rdpRdp* rdp, const BYTE* data, UINT32 length, BOOL encryption,

                                   BYTE* output)

{

	WINPR_DIGEST_CTX* sha1 = NULL;

	WINPR_DIGEST_CTX* md5 = NULL;

	BYTE length_le[4];

	BYTE use_count_le[4];

	BYTE md5_digest[WINPR_MD5_DIGEST_LENGTH];

	BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH];

	BOOL result = FALSE;

	EnterCriticalSection(&rdp->critical);

	security_UINT32_le(length_le, length); /* length must be little-endian */

	if (encryption)

	{

		security_UINT32_le(use_count_le, rdp->encrypt_checksum_use_count);

	}

	else

	{

		/*

		 * We calculate checksum on plain text, so we must have already

		 * decrypt it, which means decrypt_checksum_use_count is off by one.

		 */

		security_UINT32_le(use_count_le, rdp->decrypt_checksum_use_count - 1);

	}

	/* SHA1_Digest = SHA1(MACKeyN + pad1 + length + data) */

	if (!(sha1 = winpr_Digest_New()))

		goto out;

	if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))

		goto out;

	if (!winpr_Digest_Update(sha1, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */

		goto out;

	if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1))) /* pad1 */

		goto out;

	if (!winpr_Digest_Update(sha1, length_le, sizeof(length_le))) /* length */

		goto out;

	if (!winpr_Digest_Update(sha1, data, length)) /* data */

		goto out;

	if (!winpr_Digest_Update(sha1, use_count_le, sizeof(use_count_le))) /* encryptionCount */

		goto out;

	if (!winpr_Digest_Final(sha1, sha1_digest, sizeof(sha1_digest)))

		goto out;

	/* MACSignature = First64Bits(MD5(MACKeyN + pad2 + SHA1_Digest)) */

	if (!(md5 = winpr_Digest_New()))

		goto out;

	if (!winpr_Digest_Init(md5, WINPR_MD_MD5))

		goto out;

	if (!winpr_Digest_Update(md5, rdp->sign_key, rdp->rc4_key_len)) /* MacKeyN */

		goto out;

	if (!winpr_Digest_Update(md5, pad2, sizeof(pad2))) /* pad2 */

		goto out;

	if (!winpr_Digest_Update(md5, sha1_digest, sizeof(sha1_digest))) /* SHA1_Digest */

		goto out;

	if (!winpr_Digest_Final(md5, md5_digest, sizeof(md5_digest)))

		goto out;

	memcpy(output, md5_digest, 8);

	result = TRUE;

out:

	LeaveCriticalSection(&rdp->critical);

	winpr_Digest_Free(sha1);

	winpr_Digest_Free(md5);

	return result;

}

static BOOL security_A(BYTE* master_secret, const BYTE* client_random, BYTE* server_random,

                       BYTE* output)

{

	return security_premaster_hash("A", 1, master_secret, client_random, server_random,

	                               &output[0]) &&

	       security_premaster_hash("BB", 2, master_secret, client_random, server_random,

	                               &output[16]) &&

	       security_premaster_hash("CCC", 3, master_secret, client_random, server_random,

	                               &output[32]);

}

static BOOL security_X(BYTE* master_secret, const BYTE* client_random, BYTE* server_random,

                       BYTE* output)

{

	return security_premaster_hash("X", 1, master_secret, client_random, server_random,

	                               &output[0]) &&

	       security_premaster_hash("YY", 2, master_secret, client_random, server_random,

	                               &output[16]) &&

	       security_premaster_hash("ZZZ", 3, master_secret, client_random, server_random,

	                               &output[32]);

}

static void fips_expand_key_bits(BYTE* in, BYTE* out)

{

	BYTE buf[21], c;

	int i, b, p, r;

	/* reverse every byte in the key */

	for (i = 0; i < 21; i++)

		buf[i] = fips_reverse_table[in[i]];

	/* insert a zero-bit after every 7th bit */

	for (i = 0, b = 0; i < 24; i++, b += 7)

	{

		p = b / 8;

		r = b % 8;

		if (r <= 1)

		{

			out[i] = (buf[p] << r) & 0xfe;

		}

		else

		{

			/* c is accumulator */

			c = buf[p] << r;

			c |= buf[p + 1] >> (8 - r);

			out[i] = c & 0xfe;

		}

	}

	/* reverse every byte */

	/* alter lsb so the byte has odd parity */

	for (i = 0; i < 24; i++)

		out[i] = fips_oddparity_table[fips_reverse_table[out[i]]];

}

BOOL security_establish_keys(const BYTE* client_random, rdpRdp* rdp)

{

	BYTE pre_master_secret[48];

	BYTE master_secret[48];

	BYTE session_key_blob[48];

	BYTE* server_random;

	BYTE salt[] = { 0xD1, 0x26, 0x9E }; /* 40 bits: 3 bytes, 56 bits: 1 byte */

	rdpSettings* settings;

	BOOL status;

	settings = rdp->settings;

	server_random = settings->ServerRandom;

	if (settings->EncryptionMethods == ENCRYPTION_METHOD_FIPS)

	{

		WINPR_DIGEST_CTX* sha1;

		BYTE client_encrypt_key_t[WINPR_SHA1_DIGEST_LENGTH + 1];

		BYTE client_decrypt_key_t[WINPR_SHA1_DIGEST_LENGTH + 1];

		if (!(sha1 = winpr_Digest_New()))

			return FALSE;

		if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||

		    !winpr_Digest_Update(sha1, client_random + 16, 16) ||

		    !winpr_Digest_Update(sha1, server_random + 16, 16) ||

		    !winpr_Digest_Final(sha1, client_encrypt_key_t, sizeof(client_encrypt_key_t)))

		{

			winpr_Digest_Free(sha1);

			return FALSE;

		}

		client_encrypt_key_t[20] = client_encrypt_key_t[0];

		if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||

		    !winpr_Digest_Update(sha1, client_random, 16) ||

		    !winpr_Digest_Update(sha1, server_random, 16) ||

		    !winpr_Digest_Final(sha1, client_decrypt_key_t, sizeof(client_decrypt_key_t)))

		{

			winpr_Digest_Free(sha1);

			return FALSE;

		}

		client_decrypt_key_t[20] = client_decrypt_key_t[0];

		if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1) ||

		    !winpr_Digest_Update(sha1, client_decrypt_key_t, WINPR_SHA1_DIGEST_LENGTH) ||

		    !winpr_Digest_Update(sha1, client_encrypt_key_t, WINPR_SHA1_DIGEST_LENGTH) ||

		    !winpr_Digest_Final(sha1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))

		{

			winpr_Digest_Free(sha1);

			return FALSE;

		}

		winpr_Digest_Free(sha1);

		if (rdp->settings->ServerMode)

		{

			fips_expand_key_bits(client_encrypt_key_t, rdp->fips_decrypt_key);

			fips_expand_key_bits(client_decrypt_key_t, rdp->fips_encrypt_key);

		}

		else

		{

			fips_expand_key_bits(client_encrypt_key_t, rdp->fips_encrypt_key);

			fips_expand_key_bits(client_decrypt_key_t, rdp->fips_decrypt_key);

		}

	}

	memcpy(pre_master_secret, client_random, 24);

	memcpy(pre_master_secret + 24, server_random, 24);

	if (!security_A(pre_master_secret, client_random, server_random, master_secret) ||

	    !security_X(master_secret, client_random, server_random, session_key_blob))

	{

		return FALSE;

	}

	memcpy(rdp->sign_key, session_key_blob, 16);

	if (rdp->settings->ServerMode)

	{

		status = security_md5_16_32_32(&session_key_blob[16], client_random, server_random,

		                               rdp->encrypt_key);

		status &= security_md5_16_32_32(&session_key_blob[32], client_random, server_random,

		                                rdp->decrypt_key);

	}

	else

	{

		/* Allow FIPS use of MD5 here, this is just used for generation of the SessionKeyBlob as

		 * described in MS-RDPELE. */

		/* This is for RDP licensing packets which will already be encrypted under FIPS, so the use

		 * of MD5 here is not */

		/* for sensitive data protection. */

		status = security_md5_16_32_32_Allow_FIPS(&session_key_blob[16], client_random,

		                                          server_random, rdp->decrypt_key);

		status &= security_md5_16_32_32_Allow_FIPS(&session_key_blob[32], client_random,

		                                           server_random, rdp->encrypt_key);

	}

	if (!status)

		return FALSE;

	if (settings->EncryptionMethods == ENCRYPTION_METHOD_40BIT)

	{

		memcpy(rdp->sign_key, salt, 3);

		memcpy(rdp->decrypt_key, salt, 3);

		memcpy(rdp->encrypt_key, salt, 3);

		rdp->rc4_key_len = 8;

	}

	else if (settings->EncryptionMethods == ENCRYPTION_METHOD_56BIT)

	{

		memcpy(rdp->sign_key, salt, 1);

		memcpy(rdp->decrypt_key, salt, 1);

		memcpy(rdp->encrypt_key, salt, 1);

		rdp->rc4_key_len = 8;

	}

	else if (settings->EncryptionMethods == ENCRYPTION_METHOD_128BIT)

	{

		rdp->rc4_key_len = 16;

	}

	EnterCriticalSection(&rdp->critical);

	memcpy(rdp->decrypt_update_key, rdp->decrypt_key, 16);

	memcpy(rdp->encrypt_update_key, rdp->encrypt_key, 16);

	rdp->decrypt_use_count = 0;

	rdp->decrypt_checksum_use_count = 0;

	rdp->encrypt_use_count = 0;

	rdp->encrypt_checksum_use_count = 0;

	LeaveCriticalSection(&rdp->critical);

	return TRUE;

}

static BOOL security_key_update(BYTE* key, BYTE* update_key, int key_len, rdpRdp* rdp)

{

	BYTE sha1h[WINPR_SHA1_DIGEST_LENGTH];

	WINPR_DIGEST_CTX* sha1 = NULL;

	WINPR_DIGEST_CTX* md5 = NULL;

	WINPR_RC4_CTX* rc4 = NULL;

	BYTE salt[] = { 0xD1, 0x26, 0x9E }; /* 40 bits: 3 bytes, 56 bits: 1 byte */

	BOOL result = FALSE;

	WLog_DBG(TAG, "updating RDP key");

	if (!(sha1 = winpr_Digest_New()))

		goto out;

	if (!winpr_Digest_Init(sha1, WINPR_MD_SHA1))

		goto out;

	if (!winpr_Digest_Update(sha1, update_key, key_len))

		goto out;

	if (!winpr_Digest_Update(sha1, pad1, sizeof(pad1)))

		goto out;

	if (!winpr_Digest_Update(sha1, key, key_len))

		goto out;

	if (!winpr_Digest_Final(sha1, sha1h, sizeof(sha1h)))

		goto out;

	if (!(md5 = winpr_Digest_New()))

		goto out;

	if (!winpr_Digest_Init(md5, WINPR_MD_MD5))

		goto out;

	if (!winpr_Digest_Update(md5, update_key, key_len))

		goto out;

	if (!winpr_Digest_Update(md5, pad2, sizeof(pad2)))

		goto out;

	if (!winpr_Digest_Update(md5, sha1h, sizeof(sha1h)))

		goto out;

	if (!winpr_Digest_Final(md5, key, WINPR_MD5_DIGEST_LENGTH))

		goto out;

	if (!(rc4 = winpr_RC4_New(key, key_len)))

		goto out;

	if (!winpr_RC4_Update(rc4, key_len, key, key))

		goto out;

	if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_40BIT)

		memcpy(key, salt, 3);

	else if (rdp->settings->EncryptionMethods == ENCRYPTION_METHOD_56BIT)

		memcpy(key, salt, 1);

	result = TRUE;

out:

	winpr_Digest_Free(sha1);

	winpr_Digest_Free(md5);

	winpr_RC4_Free(rc4);

	return result;

}

BOOL security_encrypt(BYTE* data, size_t length, rdpRdp* rdp)

{

	BOOL rc = FALSE;

	EnterCriticalSection(&rdp->critical);

	if (rdp->encrypt_use_count >= 4096)

	{

		if (!security_key_update(rdp->encrypt_key, rdp->encrypt_update_key, rdp->rc4_key_len, rdp))

			goto fail;

		winpr_RC4_Free(rdp->rc4_encrypt_key);

		rdp->rc4_encrypt_key = winpr_RC4_New(rdp->encrypt_key, rdp->rc4_key_len);

		if (!rdp->rc4_encrypt_key)

			goto fail;

		rdp->encrypt_use_count = 0;

	}

	if (!winpr_RC4_Update(rdp->rc4_encrypt_key, length, data, data))

		goto fail;

	rdp->encrypt_use_count++;

	rdp->encrypt_checksum_use_count++;

	rc = TRUE;

fail:

	LeaveCriticalSection(&rdp->critical);

	return rc;

}

BOOL security_decrypt(BYTE* data, size_t length, rdpRdp* rdp)

{

	BOOL rc = FALSE;

	EnterCriticalSection(&rdp->critical);

	if (rdp->rc4_decrypt_key == NULL)

		goto fail;

	if (rdp->decrypt_use_count >= 4096)

	{

		if (!security_key_update(rdp->decrypt_key, rdp->decrypt_update_key, rdp->rc4_key_len, rdp))

			goto fail;

		winpr_RC4_Free(rdp->rc4_decrypt_key);

		rdp->rc4_decrypt_key = winpr_RC4_New(rdp->decrypt_key, rdp->rc4_key_len);

		if (!rdp->rc4_decrypt_key)

			goto fail;

		rdp->decrypt_use_count = 0;

	}

	if (!winpr_RC4_Update(rdp->rc4_decrypt_key, length, data, data))

		goto fail;

	rdp->decrypt_use_count += 1;

	rdp->decrypt_checksum_use_count++;

	rc = TRUE;

fail:

	LeaveCriticalSection(&rdp->critical);

	return rc;

}

BOOL security_hmac_signature(const BYTE* data, size_t length, BYTE* output, rdpRdp* rdp)

{

	BYTE buf[WINPR_SHA1_DIGEST_LENGTH];

	BYTE use_count_le[4];

	WINPR_HMAC_CTX* hmac;

	BOOL result = FALSE;

	EnterCriticalSection(&rdp->critical);

	security_UINT32_le(use_count_le, rdp->encrypt_use_count);

	LeaveCriticalSection(&rdp->critical);

	if (!(hmac = winpr_HMAC_New()))

		return FALSE;

	if (!winpr_HMAC_Init(hmac, WINPR_MD_SHA1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))

		goto out;

	if (!winpr_HMAC_Update(hmac, data, length))

		goto out;

	if (!winpr_HMAC_Update(hmac, use_count_le, 4))

		goto out;

	if (!winpr_HMAC_Final(hmac, buf, WINPR_SHA1_DIGEST_LENGTH))

		goto out;

	memmove(output, buf, 8);

	result = TRUE;

out:

	winpr_HMAC_Free(hmac);

	return result;

}

BOOL security_fips_encrypt(BYTE* data, size_t length, rdpRdp* rdp)

{

	BOOL rc = FALSE;

	size_t olen;

	EnterCriticalSection(&rdp->critical);

	if (!winpr_Cipher_Update(rdp->fips_encrypt, data, length, data, &olen))

		goto fail;

	rdp->encrypt_use_count++;

	rc = TRUE;

fail:

	LeaveCriticalSection(&rdp->critical);

	return rc;

}

BOOL security_fips_decrypt(BYTE* data, size_t length, rdpRdp* rdp)

{

	size_t olen;

	if (!rdp || !rdp->fips_decrypt)

		return FALSE;

	if (!winpr_Cipher_Update(rdp->fips_decrypt, data, length, data, &olen))

		return FALSE;

	return TRUE;

}

BOOL security_fips_check_signature(const BYTE* data, size_t length, const BYTE* sig, rdpRdp* rdp)

{

	BYTE buf[WINPR_SHA1_DIGEST_LENGTH];

	BYTE use_count_le[4];

	WINPR_HMAC_CTX* hmac;

	BOOL result = FALSE;

	EnterCriticalSection(&rdp->critical);

	security_UINT32_le(use_count_le, rdp->decrypt_use_count++);

	LeaveCriticalSection(&rdp->critical);

	if (!(hmac = winpr_HMAC_New()))

		return FALSE;

	if (!winpr_HMAC_Init(hmac, WINPR_MD_SHA1, rdp->fips_sign_key, WINPR_SHA1_DIGEST_LENGTH))

		goto out;

	if (!winpr_HMAC_Update(hmac, data, length))

		goto out;

	if (!winpr_HMAC_Update(hmac, use_count_le, 4))

		goto out;

	if (!winpr_HMAC_Final(hmac, buf, WINPR_SHA1_DIGEST_LENGTH))

		goto out;

	if (!memcmp(sig, buf, 8))

		result = TRUE;

out:

	winpr_HMAC_Free(hmac);

	return result;

}