/*
* 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 "qemu/osdep.h"
#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/coroutine.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);
