/**

 * 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.

 */

#include <freerdp/config.h>

#include "settings.h"

#include "security.h"

#include <freerdp/log.h>

#include <winpr/crypto.h>

#define TAG FREERDP_TAG("core")

static const BYTE A[] = { 'A' };

static const BYTE BB[] = { 'B', 'B' };

static const BYTE CCC[] = { 'C', 'C', 'C' };

/* 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, size_t salt_len, const BYTE* input,

                                 size_t length, const BYTE* salt1, size_t salt1_len,

                                 const BYTE* salt2, size_t salt2_len, BYTE* output, size_t out_len)

{

  WINPR_DIGEST_CTX* sha1 = NULL;

  WINPR_DIGEST_CTX* md5 = NULL;

  BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = { 0 };

  BOOL result = FALSE;

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

  WINPR_ASSERT(out_len >= WINPR_MD5_DIGEST_LENGTH);

  /* 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;

  WINPR_ASSERT(salt_len == 48);

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

    goto out;

  WINPR_ASSERT(salt1_len == 32);

  if (!winpr_Digest_Update(sha1, salt1, salt1_len)) /* Salt1 (32 bytes) */

    goto out;

  WINPR_ASSERT(salt2_len == 32);

  if (!winpr_Digest_Update(sha1, salt2, salt2_len)) /* 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, out_len))

    goto out;

  result = TRUE;

out:

  winpr_Digest_Free(sha1);

  winpr_Digest_Free(md5);

  return result;

}

static BOOL security_premaster_hash(const BYTE* input, size_t length, const BYTE* premaster_secret,

                                    size_t pre_len, const BYTE* client_random, size_t client_len,

                                    const BYTE* server_random, size_t server_len, BYTE* output,

                                    size_t out_len)

{

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

  return security_salted_hash(premaster_secret, pre_len, input, length, client_random, client_len,

                              server_random, server_len, output, out_len);

}

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

                            size_t client_len, const BYTE* server_random, size_t server_len,

                            BYTE* output, size_t out_len)

{

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

  WINPR_ASSERT(out_len >= 32);

  return security_premaster_hash(A, sizeof(A), premaster_secret, pre_len, client_random,

                                 client_len, server_random, server_len, &output[0], out_len) &&

         security_premaster_hash(BB, sizeof(BB), premaster_secret, pre_len, client_random,

                                 client_len, server_random, server_len, &output[16],

                                 out_len - 16) &&

         security_premaster_hash(CCC, sizeof(CCC), premaster_secret, pre_len, client_random,

                                 client_len, server_random, server_len, &output[32],

                                 out_len - 32);

}

static BOOL security_master_hash(const BYTE* input, size_t length, const BYTE* master_secret,

                                 size_t master_len, const BYTE* client_random, size_t client_len,

                                 const BYTE* server_random, size_t server_len, BYTE* output,

                                 size_t out_len)

{

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

  return security_salted_hash(master_secret, master_len, input, length, server_random, server_len,

                              client_random, client_len, output, out_len);

}

BOOL security_session_key_blob(const BYTE* master_secret, size_t master_len,

                               const BYTE* client_random, size_t client_len,

                               const BYTE* server_random, size_t server_len, BYTE* output,

                               size_t out_len)

{

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

  WINPR_ASSERT(out_len >= 32);

  return security_master_hash(A, sizeof(A), master_secret, master_len, client_random, client_len,

                              server_random, server_len, &output[0], 16) &&

         security_master_hash(BB, sizeof(BB), master_secret, master_len, client_random,

                              client_len, server_random, server_len, &output[16], 16) &&

         security_master_hash(CCC, sizeof(CCC), master_secret, master_len, client_random,

                              client_len, server_random, server_len, &output[32], out_len - 32);

}

void security_mac_salt_key(const BYTE* session_key_blob, WINPR_ATTR_UNUSED size_t session_len,

                           WINPR_ATTR_UNUSED const BYTE* client_random,

                           WINPR_ATTR_UNUSED size_t client_len,

                           WINPR_ATTR_UNUSED const BYTE* server_random,

                           WINPR_ATTR_UNUSED size_t server_len, BYTE* output,

                           WINPR_ATTR_UNUSED size_t out_len)

{

  /* MacSaltKey = First128Bits(SessionKeyBlob) */

  WINPR_ASSERT(out_len >= 16);

  WINPR_ASSERT(session_len >= 16);

  memcpy(output, session_key_blob, 16);

}

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

                                  size_t out_len)

{

  WINPR_DIGEST_CTX* md5 = NULL;

  BOOL result = FALSE;

  WINPR_ASSERT(WINPR_MD5_DIGEST_LENGTH <= out_len);

  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, out_len))

    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, size_t out_len)

{

  WINPR_DIGEST_CTX* md5 = NULL;

  BOOL result = FALSE;

  WINPR_ASSERT(out_len >= WINPR_MD5_DIGEST_LENGTH);

  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, out_len))

    goto out;

  result = TRUE;

out:

  winpr_Digest_Free(md5);

  return result;

}

BOOL security_licensing_encryption_key(const BYTE* session_key_blob, size_t session_len,

                                       const BYTE* client_random, size_t client_len,

                                       const BYTE* server_random, size_t server_len, BYTE* output,

                                       size_t out_len)

{

  if (session_len < 16)

    return FALSE;

  if (client_len < 32)

    return FALSE;

  if (server_len < 32)

    return FALSE;

  /* 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, out_len);

}

static void security_UINT32_le(BYTE* output, WINPR_ATTR_UNUSED size_t out_len, UINT32 value)

{

  WINPR_ASSERT(output);

  WINPR_ASSERT(out_len >= 4);

  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, size_t mac_salt_key_length, const BYTE* data,

                       size_t length, BYTE* output, size_t output_length)

{

  WINPR_DIGEST_CTX* sha1 = NULL;

  WINPR_DIGEST_CTX* md5 = NULL;

  BYTE length_le[4] = { 0 };

  BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = { 0 };

  BOOL result = FALSE;

  WINPR_ASSERT(length <= UINT32_MAX);

  WINPR_ASSERT(mac_salt_key_length == WINPR_MD5_DIGEST_LENGTH);

  WINPR_ASSERT(output_length == WINPR_MD5_DIGEST_LENGTH);

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

  security_UINT32_le(length_le, sizeof(length_le),

                     (UINT32)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, mac_salt_key_length)) /* 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, output_length))

    goto out;

  result = TRUE;

out:

  if (!result)

    WLog_ERR(TAG, "failed to create security mac");

  winpr_Digest_Free(sha1);

  winpr_Digest_Free(md5);

  return result;

}

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

                            size_t out_len)

{

  WINPR_DIGEST_CTX* sha1 = NULL;

  WINPR_DIGEST_CTX* md5 = NULL;

  BYTE length_le[4] = { 0 };

  BYTE md5_digest[WINPR_MD5_DIGEST_LENGTH] = { 0 };

  BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = { 0 };

  BOOL result = FALSE;

  WINPR_ASSERT(rdp);

  WINPR_ASSERT(data || (length == 0));

  WINPR_ASSERT(output);

  WINPR_ASSERT(out_len >= 8);

  if (out_len < 8)

    return FALSE;

  security_UINT32_le(length_le, sizeof(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:

  if (!result)

    WLog_WARN(TAG, "security mac generation failed");

  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, size_t out_len)

{

  WINPR_DIGEST_CTX* sha1 = NULL;

  WINPR_DIGEST_CTX* md5 = NULL;

  BYTE length_le[4] = { 0 };

  BYTE use_count_le[4] = { 0 };

  BYTE md5_digest[WINPR_MD5_DIGEST_LENGTH] = { 0 };

  BYTE sha1_digest[WINPR_SHA1_DIGEST_LENGTH] = { 0 };

  BOOL result = FALSE;

  WINPR_ASSERT(rdp);

  WINPR_ASSERT(data || (length == 0));

  WINPR_ASSERT(output);

  WINPR_ASSERT(out_len >= 8);

  if (out_len < 8)

    return FALSE;

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

  if (encryption)

  {

    security_UINT32_le(use_count_le, sizeof(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, sizeof(use_count_le),

                       rdp->decrypt_checksum_use_count - 1u);

  }

  /* 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:

  if (!result)

    WLog_WARN(TAG, "security mac signature generation failed");

  winpr_Digest_Free(sha1);

  winpr_Digest_Free(md5);

  return result;

}

static BOOL security_A(const BYTE* master_secret, size_t master_len, const BYTE* client_random,

                       size_t client_len, const BYTE* server_random, size_t server_len,

                       BYTE* output, size_t out_len)

{

  WINPR_ASSERT(out_len >= 32);

  return security_premaster_hash(A, sizeof(A), master_secret, master_len, client_random,

                                 client_len, server_random, server_len, &output[0], 16) &&

         security_premaster_hash(BB, sizeof(BB), master_secret, master_len, client_random,

                                 client_len, server_random, server_len, &output[16], 16) &&

         security_premaster_hash(CCC, sizeof(CCC), master_secret, master_len, client_random,

                                 client_len, server_random, server_len, &output[32],

                                 out_len - 32);

}

static BOOL security_X(const BYTE* master_secret, size_t master_len, const BYTE* client_random,

                       size_t client_len, const BYTE* server_random, size_t server_len,

                       BYTE* output, size_t out_len)

{

  const BYTE X[] = { 'X' };

  const BYTE YY[] = { 'Y', 'Y' };

  const BYTE ZZZ[] = { 'Z', 'Z', 'Z' };

  WINPR_ASSERT(out_len >= 32);

  return security_premaster_hash(X, sizeof(X), master_secret, master_len, client_random,

                                 client_len, server_random, server_len, &output[0], 16) &&

         security_premaster_hash(YY, sizeof(YY), master_secret, master_len, client_random,

                                 client_len, server_random, server_len, &output[16], 16) &&

         security_premaster_hash(ZZZ, sizeof(ZZZ), master_secret, master_len, client_random,

                                 client_len, server_random, server_len, &output[32],

                                 out_len - 32);

}

static void fips_expand_key_bits(const BYTE* in, WINPR_ATTR_UNUSED size_t in_len, BYTE* out,

                                 WINPR_ATTR_UNUSED size_t out_len)

{

  BYTE buf[21] = { 0 };

  WINPR_ASSERT(in);

  WINPR_ASSERT(in_len >= sizeof(buf));

  WINPR_ASSERT(out);

  WINPR_ASSERT(out_len >= 24);

  /* reverse every byte in the key */

  for (size_t i = 0; i < sizeof(buf); i++)

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

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

  size_t b = 0;

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

  {

    const size_t p = b / 8;

    const size_t r = b % 8;

    WINPR_ASSERT(p < sizeof(buf));

    if (r <= 1)

    {

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

    }

    else

    {

      WINPR_ASSERT(p + 1 < sizeof(buf));

      /* c is accumulator */

      BYTE c = (BYTE)(buf[p] << r) & 0xFF;

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

      out[i] = c & 0xfe;

    }

  }

  /* reverse every byte */

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

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

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

}

BOOL security_establish_keys(rdpRdp* rdp)

{

  BYTE pre_master_secret[48] = { 0 };

  BYTE master_secret[48] = { 0 };

  BYTE session_key_blob[48] = { 0 };

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

  BOOL status = FALSE;

  WINPR_ASSERT(rdp);

  const rdpSettings* settings = rdp->settings;

  WINPR_ASSERT(settings);

  const BYTE* server_random = freerdp_settings_get_pointer(settings, FreeRDP_ServerRandom);

  const BYTE* client_random = freerdp_settings_get_pointer(settings, FreeRDP_ClientRandom);

  WINPR_ASSERT(client_random);

  WINPR_ASSERT(server_random);

  const UINT32 ClientRandomLength =

      freerdp_settings_get_uint32(settings, FreeRDP_ClientRandomLength);

  const UINT32 ServerRandomLength =

      freerdp_settings_get_uint32(settings, FreeRDP_ServerRandomLength);

  WINPR_ASSERT(ClientRandomLength == 32);

  WINPR_ASSERT(ServerRandomLength == 32);

  if (settings->EncryptionMethods == ENCRYPTION_METHOD_FIPS)

  {

    BYTE client_encrypt_key_t[WINPR_SHA1_DIGEST_LENGTH + 1] = { 0 };

    BYTE client_decrypt_key_t[WINPR_SHA1_DIGEST_LENGTH + 1] = { 0 };

    WINPR_DIGEST_CTX* sha1 = winpr_Digest_New();

    if (!sha1)

      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 (settings->ServerMode)

    {

      fips_expand_key_bits(client_encrypt_key_t, sizeof(client_encrypt_key_t),

                           rdp->fips_decrypt_key, sizeof(rdp->fips_decrypt_key));

      fips_expand_key_bits(client_decrypt_key_t, sizeof(client_decrypt_key_t),

                           rdp->fips_encrypt_key, sizeof(rdp->fips_encrypt_key));

    }

    else

    {

      fips_expand_key_bits(client_encrypt_key_t, sizeof(client_encrypt_key_t),

                           rdp->fips_encrypt_key, sizeof(rdp->fips_encrypt_key));

      fips_expand_key_bits(client_decrypt_key_t, sizeof(client_decrypt_key_t),

                           rdp->fips_decrypt_key, sizeof(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, sizeof(pre_master_secret), client_random, ClientRandomLength,

                  server_random, ServerRandomLength, master_secret, sizeof(master_secret)) ||

      !security_X(master_secret, sizeof(master_secret), client_random, ClientRandomLength,

                  server_random, ServerRandomLength, session_key_blob, sizeof(session_key_blob)))

  {

    return FALSE;

  }

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

  if (settings->ServerMode)

  {

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

                                   rdp->encrypt_key, sizeof(rdp->encrypt_key));

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

                                    rdp->decrypt_key, sizeof(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, sizeof(rdp->decrypt_key));

    status &=

        security_md5_16_32_32_Allow_FIPS(&session_key_blob[32], client_random, server_random,

                                         rdp->encrypt_key, sizeof(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;

  }

  if (!security_lock(rdp))

    return FALSE;

  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;

  return security_unlock(rdp);

}

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

{

  BYTE sha1h[WINPR_SHA1_DIGEST_LENGTH] = { 0 };

  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;

  WINPR_ASSERT(rdp);

  if (!rdp->rc4_encrypt_key)

  {

    WLog_ERR(TAG, "rdp->rc4_encrypt_key=%p", rdp->rc4_encrypt_key);

    goto fail;

  }

  if (rdp->encrypt_use_count >= 4096)

  {

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

      goto fail;

    if (!rdp_reset_rc4_encrypt_keys(rdp))

      goto fail;

  }

  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:

  return rc;

}

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

{

  BOOL rc = FALSE;

  WINPR_ASSERT(data || (length == 0));

  WINPR_ASSERT(rdp);

  if (!rdp->rc4_decrypt_key)

  {

    WLog_ERR(TAG, "rdp->rc4_decrypt_key=%p", rdp->rc4_decrypt_key);

    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;

    if (!rdp_reset_rc4_decrypt_keys(rdp))

      goto fail;

  }

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