/* * QEMU Crypto block device encryption LUKS format * * Copyright (c) 2015-2016 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see <http://www.gnu.org/licenses/>. * */ #include "qapi/error.h" #include "qemu/bswap.h" #include "block-luks.h" #include "crypto/hash.h" #include "crypto/afsplit.h" #include "crypto/pbkdf.h" #include "crypto/secret.h" #include "crypto/random.h" #include "qemu/uuid.h" #include "qemu/bitmap.h" /* * Reference for the LUKS format implemented here is * * docs/on-disk-format.pdf * * in 'cryptsetup' package source code * * This file implements the 1.2.1 specification, dated * Oct 16, 2011. */ typedef struct QCryptoBlockLUKSHeader QCryptoBlockLUKSHeader; typedef struct QCryptoBlockLUKSKeySlot QCryptoBlockLUKSKeySlot; /* The following constants are all defined by the LUKS spec */ #define QCRYPTO_BLOCK_LUKS_VERSION 1 #define QCRYPTO_BLOCK_LUKS_MAGIC_LEN 6 #define QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN 32 #define QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN 32 #define QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN 32 #define QCRYPTO_BLOCK_LUKS_DIGEST_LEN 20 #define QCRYPTO_BLOCK_LUKS_SALT_LEN 32 #define QCRYPTO_BLOCK_LUKS_UUID_LEN 40 #define QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS 8 #define QCRYPTO_BLOCK_LUKS_STRIPES 4000 #define QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS 1000 #define QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS 1000 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET 4096 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED 0x0000DEAD #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED 0x00AC71F3 #define QCRYPTO_BLOCK_LUKS_SECTOR_SIZE 512LL #define QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS 2000 #define QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS 40 static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = { 'L', 'U', 'K', 'S', 0xBA, 0xBE }; /* * This struct is written to disk in big-endian format, * but operated upon in native-endian format. */ struct QCryptoBlockLUKSKeySlot { /* state of keyslot, enabled/disable */ uint32_t active; /* iterations for PBKDF2 */ uint32_t iterations; /* salt for PBKDF2 */ uint8_t salt[QCRYPTO_BLOCK_LUKS_SALT_LEN]; /* start sector of key material */ uint32_t key_offset_sector; /* number of anti-forensic stripes */ uint32_t stripes; }; /* * This struct is written to disk in big-endian format, * but operated upon in native-endian format. */ struct QCryptoBlockLUKSHeader { /* 'L', 'U', 'K', 'S', '0xBA', '0xBE' */ char magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN]; /* LUKS version, currently 1 */ uint16_t version; /* cipher name specification (aes, etc) */ char cipher_name[QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN]; /* cipher mode specification (cbc-plain, xts-essiv:sha256, etc) */ char cipher_mode[QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN]; /* hash specification (sha256, etc) */ char hash_spec[QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN]; /* start offset of the volume data (in 512 byte sectors) */ uint32_t payload_offset_sector; /* Number of key bytes */ uint32_t master_key_len; /* master key checksum after PBKDF2 */ uint8_t master_key_digest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; /* salt for master key PBKDF2 */ uint8_t master_key_salt[QCRYPTO_BLOCK_LUKS_SALT_LEN]; /* iterations for master key PBKDF2 */ uint32_t master_key_iterations; /* UUID of the partition in standard ASCII representation */ uint8_t uuid[QCRYPTO_BLOCK_LUKS_UUID_LEN]; /* key slots */ QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS]; }; void qcrypto_block_luks_to_disk_endian(QCryptoBlockLUKSHeader *hdr); void qcrypto_block_luks_from_disk_endian(QCryptoBlockLUKSHeader *hdr);