/** * FreeRDP: A Remote Desktop Protocol Implementation * RDP Security * * Copyright 2011 Marc-Andre Moreau * Copyright 2014 Norbert Federa * * 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 #include "settings.h" #include "security.h" #include #include #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)) goto fail; rdp->decrypt_use_count += 1; rdp->decrypt_checksum_use_count++; rc = TRUE; fail: if (!rc) WLog_WARN(TAG, "Failed to decrypt security"); return rc; } BOOL security_hmac_signature(const BYTE* data, size_t length, BYTE* output, size_t out_len, rdpRdp* rdp) { BYTE buf[WINPR_SHA1_DIGEST_LENGTH] = { 0 }; BYTE use_count_le[4] = { 0 }; WINPR_HMAC_CTX* hmac = NULL; BOOL result = FALSE; WINPR_ASSERT(rdp); WINPR_ASSERT(output); if (out_len < 8) return FALSE; security_UINT32_le(use_count_le, sizeof(use_count_le), rdp->encrypt_use_count); 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 = 0; if (!winpr_Cipher_Update(rdp->fips_encrypt, data, length, data, &olen)) goto fail; rdp->encrypt_use_count++; rc = TRUE; fail: return rc; } BOOL security_fips_decrypt(BYTE* data, size_t length, rdpRdp* rdp) { size_t olen = 0; if (!rdp || !rdp->fips_decrypt) { WLog_ERR(TAG, "rdp=%p, rdp->fips_decrypt=%p", rdp, rdp ? rdp->fips_decrypt : NULL); 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, size_t sig_len, rdpRdp* rdp) { BYTE buf[WINPR_SHA1_DIGEST_LENGTH] = { 0 }; BYTE use_count_le[4] = { 0 }; WINPR_HMAC_CTX* hmac = NULL; BOOL result = FALSE; security_UINT32_le(use_count_le, sizeof(use_count_le), rdp->decrypt_use_count++); if (!(hmac = winpr_HMAC_New())) goto out; 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 ((sig_len >= 8) && (memcmp(sig, buf, 8) == 0)) result = TRUE; out: if (!result) WLog_WARN(TAG, "signature check failed"); winpr_HMAC_Free(hmac); return result; } BOOL security_lock(rdpRdp* rdp) { WINPR_ASSERT(rdp); EnterCriticalSection(&rdp->critical); return TRUE; } BOOL security_unlock(rdpRdp* rdp) { WINPR_ASSERT(rdp); LeaveCriticalSection(&rdp->critical); return TRUE; }