1441 lines
48 KiB
C
1441 lines
48 KiB
C
/*
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* QEMU Crypto block device encryption LUKS format
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*
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* Copyright (c) 2015-2016 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "qemu/osdep.h"
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#include "qapi/error.h"
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#include "qemu/bswap.h"
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#include "crypto/block-luks.h"
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#include "crypto/hash.h"
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#include "crypto/afsplit.h"
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#include "crypto/pbkdf.h"
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#include "crypto/secret.h"
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#include "crypto/random.h"
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#include "qemu/uuid.h"
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#include "qemu/coroutine.h"
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/*
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* Reference for the LUKS format implemented here is
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*
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* docs/on-disk-format.pdf
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*
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* in 'cryptsetup' package source code
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*
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* This file implements the 1.2.1 specification, dated
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* Oct 16, 2011.
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*/
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typedef struct QCryptoBlockLUKS QCryptoBlockLUKS;
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typedef struct QCryptoBlockLUKSHeader QCryptoBlockLUKSHeader;
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typedef struct QCryptoBlockLUKSKeySlot QCryptoBlockLUKSKeySlot;
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/* The following constants are all defined by the LUKS spec */
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#define QCRYPTO_BLOCK_LUKS_VERSION 1
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#define QCRYPTO_BLOCK_LUKS_MAGIC_LEN 6
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#define QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN 32
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#define QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN 32
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#define QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN 32
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#define QCRYPTO_BLOCK_LUKS_DIGEST_LEN 20
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#define QCRYPTO_BLOCK_LUKS_SALT_LEN 32
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#define QCRYPTO_BLOCK_LUKS_UUID_LEN 40
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#define QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS 8
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#define QCRYPTO_BLOCK_LUKS_STRIPES 4000
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#define QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS 1000
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#define QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS 1000
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#define QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET 4096
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#define QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED 0x0000DEAD
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#define QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED 0x00AC71F3
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#define QCRYPTO_BLOCK_LUKS_SECTOR_SIZE 512LL
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static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = {
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'L', 'U', 'K', 'S', 0xBA, 0xBE
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};
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typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap;
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struct QCryptoBlockLUKSNameMap {
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const char *name;
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int id;
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};
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typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap;
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struct QCryptoBlockLUKSCipherSizeMap {
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uint32_t key_bytes;
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int id;
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};
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typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap;
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struct QCryptoBlockLUKSCipherNameMap {
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const char *name;
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const QCryptoBlockLUKSCipherSizeMap *sizes;
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};
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static const QCryptoBlockLUKSCipherSizeMap
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qcrypto_block_luks_cipher_size_map_aes[] = {
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{ 16, QCRYPTO_CIPHER_ALG_AES_128 },
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{ 24, QCRYPTO_CIPHER_ALG_AES_192 },
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{ 32, QCRYPTO_CIPHER_ALG_AES_256 },
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{ 0, 0 },
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};
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static const QCryptoBlockLUKSCipherSizeMap
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qcrypto_block_luks_cipher_size_map_cast5[] = {
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{ 16, QCRYPTO_CIPHER_ALG_CAST5_128 },
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{ 0, 0 },
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};
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static const QCryptoBlockLUKSCipherSizeMap
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qcrypto_block_luks_cipher_size_map_serpent[] = {
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{ 16, QCRYPTO_CIPHER_ALG_SERPENT_128 },
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{ 24, QCRYPTO_CIPHER_ALG_SERPENT_192 },
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{ 32, QCRYPTO_CIPHER_ALG_SERPENT_256 },
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{ 0, 0 },
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};
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static const QCryptoBlockLUKSCipherSizeMap
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qcrypto_block_luks_cipher_size_map_twofish[] = {
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{ 16, QCRYPTO_CIPHER_ALG_TWOFISH_128 },
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{ 24, QCRYPTO_CIPHER_ALG_TWOFISH_192 },
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{ 32, QCRYPTO_CIPHER_ALG_TWOFISH_256 },
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{ 0, 0 },
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};
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static const QCryptoBlockLUKSCipherNameMap
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qcrypto_block_luks_cipher_name_map[] = {
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{ "aes", qcrypto_block_luks_cipher_size_map_aes },
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{ "cast5", qcrypto_block_luks_cipher_size_map_cast5 },
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{ "serpent", qcrypto_block_luks_cipher_size_map_serpent },
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{ "twofish", qcrypto_block_luks_cipher_size_map_twofish },
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};
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/*
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* This struct is written to disk in big-endian format,
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* but operated upon in native-endian format.
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*/
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struct QCryptoBlockLUKSKeySlot {
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/* state of keyslot, enabled/disable */
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uint32_t active;
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/* iterations for PBKDF2 */
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uint32_t iterations;
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/* salt for PBKDF2 */
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uint8_t salt[QCRYPTO_BLOCK_LUKS_SALT_LEN];
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/* start sector of key material */
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uint32_t key_offset;
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/* number of anti-forensic stripes */
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uint32_t stripes;
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} QEMU_PACKED;
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QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48);
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/*
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* This struct is written to disk in big-endian format,
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* but operated upon in native-endian format.
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*/
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struct QCryptoBlockLUKSHeader {
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/* 'L', 'U', 'K', 'S', '0xBA', '0xBE' */
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char magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN];
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/* LUKS version, currently 1 */
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uint16_t version;
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/* cipher name specification (aes, etc) */
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char cipher_name[QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN];
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/* cipher mode specification (cbc-plain, xts-essiv:sha256, etc) */
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char cipher_mode[QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN];
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/* hash specification (sha256, etc) */
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char hash_spec[QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN];
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/* start offset of the volume data (in 512 byte sectors) */
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uint32_t payload_offset;
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/* Number of key bytes */
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uint32_t key_bytes;
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/* master key checksum after PBKDF2 */
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uint8_t master_key_digest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN];
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/* salt for master key PBKDF2 */
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uint8_t master_key_salt[QCRYPTO_BLOCK_LUKS_SALT_LEN];
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/* iterations for master key PBKDF2 */
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uint32_t master_key_iterations;
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/* UUID of the partition in standard ASCII representation */
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uint8_t uuid[QCRYPTO_BLOCK_LUKS_UUID_LEN];
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/* key slots */
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QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS];
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} QEMU_PACKED;
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QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592);
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struct QCryptoBlockLUKS {
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QCryptoBlockLUKSHeader header;
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/* Cache parsed versions of what's in header fields,
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* as we can't rely on QCryptoBlock.cipher being
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* non-NULL */
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QCryptoCipherAlgorithm cipher_alg;
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QCryptoCipherMode cipher_mode;
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QCryptoIVGenAlgorithm ivgen_alg;
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QCryptoHashAlgorithm ivgen_hash_alg;
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QCryptoHashAlgorithm hash_alg;
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};
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static int qcrypto_block_luks_cipher_name_lookup(const char *name,
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QCryptoCipherMode mode,
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uint32_t key_bytes,
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Error **errp)
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{
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const QCryptoBlockLUKSCipherNameMap *map =
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qcrypto_block_luks_cipher_name_map;
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size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
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size_t i, j;
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if (mode == QCRYPTO_CIPHER_MODE_XTS) {
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key_bytes /= 2;
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}
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for (i = 0; i < maplen; i++) {
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if (!g_str_equal(map[i].name, name)) {
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continue;
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}
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for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
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if (map[i].sizes[j].key_bytes == key_bytes) {
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return map[i].sizes[j].id;
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}
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}
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}
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error_setg(errp, "Algorithm %s with key size %d bytes not supported",
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name, key_bytes);
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return 0;
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}
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static const char *
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qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgorithm alg,
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Error **errp)
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{
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const QCryptoBlockLUKSCipherNameMap *map =
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qcrypto_block_luks_cipher_name_map;
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size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
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size_t i, j;
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for (i = 0; i < maplen; i++) {
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for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
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if (map[i].sizes[j].id == alg) {
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return map[i].name;
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}
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}
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}
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error_setg(errp, "Algorithm '%s' not supported",
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QCryptoCipherAlgorithm_lookup[alg]);
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return NULL;
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}
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/* XXX replace with qapi_enum_parse() in future, when we can
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* make that function emit a more friendly error message */
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static int qcrypto_block_luks_name_lookup(const char *name,
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const char *const *map,
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size_t maplen,
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const char *type,
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Error **errp)
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{
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size_t i;
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for (i = 0; i < maplen; i++) {
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if (g_str_equal(map[i], name)) {
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return i;
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}
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}
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error_setg(errp, "%s %s not supported", type, name);
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return 0;
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}
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#define qcrypto_block_luks_cipher_mode_lookup(name, errp) \
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qcrypto_block_luks_name_lookup(name, \
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QCryptoCipherMode_lookup, \
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QCRYPTO_CIPHER_MODE__MAX, \
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"Cipher mode", \
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errp)
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#define qcrypto_block_luks_hash_name_lookup(name, errp) \
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qcrypto_block_luks_name_lookup(name, \
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QCryptoHashAlgorithm_lookup, \
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QCRYPTO_HASH_ALG__MAX, \
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"Hash algorithm", \
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errp)
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#define qcrypto_block_luks_ivgen_name_lookup(name, errp) \
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qcrypto_block_luks_name_lookup(name, \
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QCryptoIVGenAlgorithm_lookup, \
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QCRYPTO_IVGEN_ALG__MAX, \
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"IV generator", \
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errp)
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static bool
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qcrypto_block_luks_has_format(const uint8_t *buf,
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size_t buf_size)
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{
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const QCryptoBlockLUKSHeader *luks_header = (const void *)buf;
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if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) &&
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memcmp(luks_header->magic, qcrypto_block_luks_magic,
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QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 &&
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be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) {
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return true;
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} else {
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return false;
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}
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}
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/**
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* Deal with a quirk of dm-crypt usage of ESSIV.
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*
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* When calculating ESSIV IVs, the cipher length used by ESSIV
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* may be different from the cipher length used for the block
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* encryption, becauses dm-crypt uses the hash digest length
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* as the key size. ie, if you have AES 128 as the block cipher
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* and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as
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* the cipher since that gets a key length matching the digest
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* size, not AES 128 with truncated digest as might be imagined
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*/
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static QCryptoCipherAlgorithm
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qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm cipher,
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QCryptoHashAlgorithm hash,
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Error **errp)
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{
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size_t digestlen = qcrypto_hash_digest_len(hash);
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size_t keylen = qcrypto_cipher_get_key_len(cipher);
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if (digestlen == keylen) {
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return cipher;
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}
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switch (cipher) {
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case QCRYPTO_CIPHER_ALG_AES_128:
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case QCRYPTO_CIPHER_ALG_AES_192:
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case QCRYPTO_CIPHER_ALG_AES_256:
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if (digestlen == qcrypto_cipher_get_key_len(
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QCRYPTO_CIPHER_ALG_AES_128)) {
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return QCRYPTO_CIPHER_ALG_AES_128;
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} else if (digestlen == qcrypto_cipher_get_key_len(
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QCRYPTO_CIPHER_ALG_AES_192)) {
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return QCRYPTO_CIPHER_ALG_AES_192;
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} else if (digestlen == qcrypto_cipher_get_key_len(
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QCRYPTO_CIPHER_ALG_AES_256)) {
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return QCRYPTO_CIPHER_ALG_AES_256;
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} else {
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error_setg(errp, "No AES cipher with key size %zu available",
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digestlen);
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return 0;
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}
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break;
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case QCRYPTO_CIPHER_ALG_SERPENT_128:
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case QCRYPTO_CIPHER_ALG_SERPENT_192:
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case QCRYPTO_CIPHER_ALG_SERPENT_256:
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if (digestlen == qcrypto_cipher_get_key_len(
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QCRYPTO_CIPHER_ALG_SERPENT_128)) {
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return QCRYPTO_CIPHER_ALG_SERPENT_128;
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} else if (digestlen == qcrypto_cipher_get_key_len(
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QCRYPTO_CIPHER_ALG_SERPENT_192)) {
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return QCRYPTO_CIPHER_ALG_SERPENT_192;
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} else if (digestlen == qcrypto_cipher_get_key_len(
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QCRYPTO_CIPHER_ALG_SERPENT_256)) {
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return QCRYPTO_CIPHER_ALG_SERPENT_256;
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} else {
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error_setg(errp, "No Serpent cipher with key size %zu available",
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digestlen);
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return 0;
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}
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break;
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case QCRYPTO_CIPHER_ALG_TWOFISH_128:
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case QCRYPTO_CIPHER_ALG_TWOFISH_192:
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case QCRYPTO_CIPHER_ALG_TWOFISH_256:
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if (digestlen == qcrypto_cipher_get_key_len(
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QCRYPTO_CIPHER_ALG_TWOFISH_128)) {
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return QCRYPTO_CIPHER_ALG_TWOFISH_128;
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} else if (digestlen == qcrypto_cipher_get_key_len(
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QCRYPTO_CIPHER_ALG_TWOFISH_192)) {
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return QCRYPTO_CIPHER_ALG_TWOFISH_192;
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} else if (digestlen == qcrypto_cipher_get_key_len(
|
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QCRYPTO_CIPHER_ALG_TWOFISH_256)) {
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return QCRYPTO_CIPHER_ALG_TWOFISH_256;
|
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} else {
|
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error_setg(errp, "No Twofish cipher with key size %zu available",
|
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digestlen);
|
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return 0;
|
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}
|
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break;
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default:
|
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error_setg(errp, "Cipher %s not supported with essiv",
|
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QCryptoCipherAlgorithm_lookup[cipher]);
|
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return 0;
|
|
}
|
|
}
|
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|
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/*
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* Given a key slot, and user password, this will attempt to unlock
|
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* the master encryption key from the key slot.
|
|
*
|
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* Returns:
|
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* 0 if the key slot is disabled, or key could not be decrypted
|
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* with the provided password
|
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* 1 if the key slot is enabled, and key decrypted successfully
|
|
* with the provided password
|
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* -1 if a fatal error occurred loading the key
|
|
*/
|
|
static int
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qcrypto_block_luks_load_key(QCryptoBlock *block,
|
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QCryptoBlockLUKSKeySlot *slot,
|
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const char *password,
|
|
QCryptoCipherAlgorithm cipheralg,
|
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QCryptoCipherMode ciphermode,
|
|
QCryptoHashAlgorithm hash,
|
|
QCryptoIVGenAlgorithm ivalg,
|
|
QCryptoCipherAlgorithm ivcipheralg,
|
|
QCryptoHashAlgorithm ivhash,
|
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uint8_t *masterkey,
|
|
size_t masterkeylen,
|
|
QCryptoBlockReadFunc readfunc,
|
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void *opaque,
|
|
Error **errp)
|
|
{
|
|
QCryptoBlockLUKS *luks = block->opaque;
|
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uint8_t *splitkey;
|
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size_t splitkeylen;
|
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uint8_t *possiblekey;
|
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int ret = -1;
|
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ssize_t rv;
|
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QCryptoCipher *cipher = NULL;
|
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uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN];
|
|
QCryptoIVGen *ivgen = NULL;
|
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size_t niv;
|
|
|
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if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) {
|
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return 0;
|
|
}
|
|
|
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splitkeylen = masterkeylen * slot->stripes;
|
|
splitkey = g_new0(uint8_t, splitkeylen);
|
|
possiblekey = g_new0(uint8_t, masterkeylen);
|
|
|
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/*
|
|
* The user password is used to generate a (possible)
|
|
* decryption key. This may or may not successfully
|
|
* decrypt the master key - we just blindly assume
|
|
* the key is correct and validate the results of
|
|
* decryption later.
|
|
*/
|
|
if (qcrypto_pbkdf2(hash,
|
|
(const uint8_t *)password, strlen(password),
|
|
slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN,
|
|
slot->iterations,
|
|
possiblekey, masterkeylen,
|
|
errp) < 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
/*
|
|
* We need to read the master key material from the
|
|
* LUKS key material header. What we're reading is
|
|
* not the raw master key, but rather the data after
|
|
* it has been passed through AFSplit and the result
|
|
* then encrypted.
|
|
*/
|
|
rv = readfunc(block,
|
|
slot->key_offset * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
|
|
splitkey, splitkeylen,
|
|
opaque,
|
|
errp);
|
|
if (rv < 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
|
|
/* Setup the cipher/ivgen that we'll use to try to decrypt
|
|
* the split master key material */
|
|
cipher = qcrypto_cipher_new(cipheralg, ciphermode,
|
|
possiblekey, masterkeylen,
|
|
errp);
|
|
if (!cipher) {
|
|
goto cleanup;
|
|
}
|
|
|
|
niv = qcrypto_cipher_get_iv_len(cipheralg,
|
|
ciphermode);
|
|
ivgen = qcrypto_ivgen_new(ivalg,
|
|
ivcipheralg,
|
|
ivhash,
|
|
possiblekey, masterkeylen,
|
|
errp);
|
|
if (!ivgen) {
|
|
goto cleanup;
|
|
}
|
|
|
|
|
|
/*
|
|
* The master key needs to be decrypted in the same
|
|
* way that the block device payload will be decrypted
|
|
* later. In particular we'll be using the IV generator
|
|
* to reset the encryption cipher every time the master
|
|
* key crosses a sector boundary.
|
|
*/
|
|
if (qcrypto_block_decrypt_helper(cipher,
|
|
niv,
|
|
ivgen,
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
|
|
0,
|
|
splitkey,
|
|
splitkeylen,
|
|
errp) < 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
/*
|
|
* Now we've decrypted the split master key, join
|
|
* it back together to get the actual master key.
|
|
*/
|
|
if (qcrypto_afsplit_decode(hash,
|
|
masterkeylen,
|
|
slot->stripes,
|
|
splitkey,
|
|
masterkey,
|
|
errp) < 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
|
|
/*
|
|
* We still don't know that the masterkey we got is valid,
|
|
* because we just blindly assumed the user's password
|
|
* was correct. This is where we now verify it. We are
|
|
* creating a hash of the master key using PBKDF and
|
|
* then comparing that to the hash stored in the key slot
|
|
* header
|
|
*/
|
|
if (qcrypto_pbkdf2(hash,
|
|
masterkey, masterkeylen,
|
|
luks->header.master_key_salt,
|
|
QCRYPTO_BLOCK_LUKS_SALT_LEN,
|
|
luks->header.master_key_iterations,
|
|
keydigest, G_N_ELEMENTS(keydigest),
|
|
errp) < 0) {
|
|
goto cleanup;
|
|
}
|
|
|
|
if (memcmp(keydigest, luks->header.master_key_digest,
|
|
QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) {
|
|
/* Success, we got the right master key */
|
|
ret = 1;
|
|
goto cleanup;
|
|
}
|
|
|
|
/* Fail, user's password was not valid for this key slot,
|
|
* tell caller to try another slot */
|
|
ret = 0;
|
|
|
|
cleanup:
|
|
qcrypto_ivgen_free(ivgen);
|
|
qcrypto_cipher_free(cipher);
|
|
g_free(splitkey);
|
|
g_free(possiblekey);
|
|
return ret;
|
|
}
|
|
|
|
|
|
/*
|
|
* Given a user password, this will iterate over all key
|
|
* slots and try to unlock each active key slot using the
|
|
* password until it successfully obtains a master key.
|
|
*
|
|
* Returns 0 if a key was loaded, -1 if no keys could be loaded
|
|
*/
|
|
static int
|
|
qcrypto_block_luks_find_key(QCryptoBlock *block,
|
|
const char *password,
|
|
QCryptoCipherAlgorithm cipheralg,
|
|
QCryptoCipherMode ciphermode,
|
|
QCryptoHashAlgorithm hash,
|
|
QCryptoIVGenAlgorithm ivalg,
|
|
QCryptoCipherAlgorithm ivcipheralg,
|
|
QCryptoHashAlgorithm ivhash,
|
|
uint8_t **masterkey,
|
|
size_t *masterkeylen,
|
|
QCryptoBlockReadFunc readfunc,
|
|
void *opaque,
|
|
Error **errp)
|
|
{
|
|
QCryptoBlockLUKS *luks = block->opaque;
|
|
size_t i;
|
|
int rv;
|
|
|
|
*masterkey = g_new0(uint8_t, luks->header.key_bytes);
|
|
*masterkeylen = luks->header.key_bytes;
|
|
|
|
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
|
|
rv = qcrypto_block_luks_load_key(block,
|
|
&luks->header.key_slots[i],
|
|
password,
|
|
cipheralg,
|
|
ciphermode,
|
|
hash,
|
|
ivalg,
|
|
ivcipheralg,
|
|
ivhash,
|
|
*masterkey,
|
|
*masterkeylen,
|
|
readfunc,
|
|
opaque,
|
|
errp);
|
|
if (rv < 0) {
|
|
goto error;
|
|
}
|
|
if (rv == 1) {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
error_setg(errp, "Invalid password, cannot unlock any keyslot");
|
|
|
|
error:
|
|
g_free(*masterkey);
|
|
*masterkey = NULL;
|
|
*masterkeylen = 0;
|
|
return -1;
|
|
}
|
|
|
|
|
|
static int
|
|
qcrypto_block_luks_open(QCryptoBlock *block,
|
|
QCryptoBlockOpenOptions *options,
|
|
const char *optprefix,
|
|
QCryptoBlockReadFunc readfunc,
|
|
void *opaque,
|
|
unsigned int flags,
|
|
Error **errp)
|
|
{
|
|
QCryptoBlockLUKS *luks;
|
|
Error *local_err = NULL;
|
|
int ret = 0;
|
|
size_t i;
|
|
ssize_t rv;
|
|
uint8_t *masterkey = NULL;
|
|
size_t masterkeylen;
|
|
char *ivgen_name, *ivhash_name;
|
|
QCryptoCipherMode ciphermode;
|
|
QCryptoCipherAlgorithm cipheralg;
|
|
QCryptoIVGenAlgorithm ivalg;
|
|
QCryptoCipherAlgorithm ivcipheralg;
|
|
QCryptoHashAlgorithm hash;
|
|
QCryptoHashAlgorithm ivhash;
|
|
char *password = NULL;
|
|
|
|
if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
|
|
if (!options->u.luks.key_secret) {
|
|
error_setg(errp, "Parameter '%skey-secret' is required for cipher",
|
|
optprefix ? optprefix : "");
|
|
return -1;
|
|
}
|
|
password = qcrypto_secret_lookup_as_utf8(
|
|
options->u.luks.key_secret, errp);
|
|
if (!password) {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
luks = g_new0(QCryptoBlockLUKS, 1);
|
|
block->opaque = luks;
|
|
|
|
/* Read the entire LUKS header, minus the key material from
|
|
* the underlying device */
|
|
rv = readfunc(block, 0,
|
|
(uint8_t *)&luks->header,
|
|
sizeof(luks->header),
|
|
opaque,
|
|
errp);
|
|
if (rv < 0) {
|
|
ret = rv;
|
|
goto fail;
|
|
}
|
|
|
|
/* The header is always stored in big-endian format, so
|
|
* convert everything to native */
|
|
be16_to_cpus(&luks->header.version);
|
|
be32_to_cpus(&luks->header.payload_offset);
|
|
be32_to_cpus(&luks->header.key_bytes);
|
|
be32_to_cpus(&luks->header.master_key_iterations);
|
|
|
|
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
|
|
be32_to_cpus(&luks->header.key_slots[i].active);
|
|
be32_to_cpus(&luks->header.key_slots[i].iterations);
|
|
be32_to_cpus(&luks->header.key_slots[i].key_offset);
|
|
be32_to_cpus(&luks->header.key_slots[i].stripes);
|
|
}
|
|
|
|
if (memcmp(luks->header.magic, qcrypto_block_luks_magic,
|
|
QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) {
|
|
error_setg(errp, "Volume is not in LUKS format");
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) {
|
|
error_setg(errp, "LUKS version %" PRIu32 " is not supported",
|
|
luks->header.version);
|
|
ret = -ENOTSUP;
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* The cipher_mode header contains a string that we have
|
|
* to further parse, of the format
|
|
*
|
|
* <cipher-mode>-<iv-generator>[:<iv-hash>]
|
|
*
|
|
* eg cbc-essiv:sha256, cbc-plain64
|
|
*/
|
|
ivgen_name = strchr(luks->header.cipher_mode, '-');
|
|
if (!ivgen_name) {
|
|
ret = -EINVAL;
|
|
error_setg(errp, "Unexpected cipher mode string format %s",
|
|
luks->header.cipher_mode);
|
|
goto fail;
|
|
}
|
|
*ivgen_name = '\0';
|
|
ivgen_name++;
|
|
|
|
ivhash_name = strchr(ivgen_name, ':');
|
|
if (!ivhash_name) {
|
|
ivhash = 0;
|
|
} else {
|
|
*ivhash_name = '\0';
|
|
ivhash_name++;
|
|
|
|
ivhash = qcrypto_block_luks_hash_name_lookup(ivhash_name,
|
|
&local_err);
|
|
if (local_err) {
|
|
ret = -ENOTSUP;
|
|
error_propagate(errp, local_err);
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
ciphermode = qcrypto_block_luks_cipher_mode_lookup(luks->header.cipher_mode,
|
|
&local_err);
|
|
if (local_err) {
|
|
ret = -ENOTSUP;
|
|
error_propagate(errp, local_err);
|
|
goto fail;
|
|
}
|
|
|
|
cipheralg = qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name,
|
|
ciphermode,
|
|
luks->header.key_bytes,
|
|
&local_err);
|
|
if (local_err) {
|
|
ret = -ENOTSUP;
|
|
error_propagate(errp, local_err);
|
|
goto fail;
|
|
}
|
|
|
|
hash = qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec,
|
|
&local_err);
|
|
if (local_err) {
|
|
ret = -ENOTSUP;
|
|
error_propagate(errp, local_err);
|
|
goto fail;
|
|
}
|
|
|
|
ivalg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name,
|
|
&local_err);
|
|
if (local_err) {
|
|
ret = -ENOTSUP;
|
|
error_propagate(errp, local_err);
|
|
goto fail;
|
|
}
|
|
|
|
if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) {
|
|
if (!ivhash_name) {
|
|
ret = -EINVAL;
|
|
error_setg(errp, "Missing IV generator hash specification");
|
|
goto fail;
|
|
}
|
|
ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg,
|
|
ivhash,
|
|
&local_err);
|
|
if (local_err) {
|
|
ret = -ENOTSUP;
|
|
error_propagate(errp, local_err);
|
|
goto fail;
|
|
}
|
|
} else {
|
|
/* Note we parsed the ivhash_name earlier in the cipher_mode
|
|
* spec string even with plain/plain64 ivgens, but we
|
|
* will ignore it, since it is irrelevant for these ivgens.
|
|
* This is for compat with dm-crypt which will silently
|
|
* ignore hash names with these ivgens rather than report
|
|
* an error about the invalid usage
|
|
*/
|
|
ivcipheralg = cipheralg;
|
|
}
|
|
|
|
if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
|
|
/* Try to find which key slot our password is valid for
|
|
* and unlock the master key from that slot.
|
|
*/
|
|
if (qcrypto_block_luks_find_key(block,
|
|
password,
|
|
cipheralg, ciphermode,
|
|
hash,
|
|
ivalg,
|
|
ivcipheralg,
|
|
ivhash,
|
|
&masterkey, &masterkeylen,
|
|
readfunc, opaque,
|
|
errp) < 0) {
|
|
ret = -EACCES;
|
|
goto fail;
|
|
}
|
|
|
|
/* We have a valid master key now, so can setup the
|
|
* block device payload decryption objects
|
|
*/
|
|
block->kdfhash = hash;
|
|
block->niv = qcrypto_cipher_get_iv_len(cipheralg,
|
|
ciphermode);
|
|
block->ivgen = qcrypto_ivgen_new(ivalg,
|
|
ivcipheralg,
|
|
ivhash,
|
|
masterkey, masterkeylen,
|
|
errp);
|
|
if (!block->ivgen) {
|
|
ret = -ENOTSUP;
|
|
goto fail;
|
|
}
|
|
|
|
block->cipher = qcrypto_cipher_new(cipheralg,
|
|
ciphermode,
|
|
masterkey, masterkeylen,
|
|
errp);
|
|
if (!block->cipher) {
|
|
ret = -ENOTSUP;
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
block->payload_offset = luks->header.payload_offset *
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
|
|
|
|
luks->cipher_alg = cipheralg;
|
|
luks->cipher_mode = ciphermode;
|
|
luks->ivgen_alg = ivalg;
|
|
luks->ivgen_hash_alg = ivhash;
|
|
luks->hash_alg = hash;
|
|
|
|
g_free(masterkey);
|
|
g_free(password);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
g_free(masterkey);
|
|
qcrypto_cipher_free(block->cipher);
|
|
qcrypto_ivgen_free(block->ivgen);
|
|
g_free(luks);
|
|
g_free(password);
|
|
return ret;
|
|
}
|
|
|
|
|
|
static void
|
|
qcrypto_block_luks_uuid_gen(uint8_t *uuidstr)
|
|
{
|
|
QemuUUID uuid;
|
|
qemu_uuid_generate(&uuid);
|
|
qemu_uuid_unparse(&uuid, (char *)uuidstr);
|
|
}
|
|
|
|
static int
|
|
qcrypto_block_luks_create(QCryptoBlock *block,
|
|
QCryptoBlockCreateOptions *options,
|
|
const char *optprefix,
|
|
QCryptoBlockInitFunc initfunc,
|
|
QCryptoBlockWriteFunc writefunc,
|
|
void *opaque,
|
|
Error **errp)
|
|
{
|
|
QCryptoBlockLUKS *luks;
|
|
QCryptoBlockCreateOptionsLUKS luks_opts;
|
|
Error *local_err = NULL;
|
|
uint8_t *masterkey = NULL;
|
|
uint8_t *slotkey = NULL;
|
|
uint8_t *splitkey = NULL;
|
|
size_t splitkeylen = 0;
|
|
size_t i;
|
|
QCryptoCipher *cipher = NULL;
|
|
QCryptoIVGen *ivgen = NULL;
|
|
char *password;
|
|
const char *cipher_alg;
|
|
const char *cipher_mode;
|
|
const char *ivgen_alg;
|
|
const char *ivgen_hash_alg = NULL;
|
|
const char *hash_alg;
|
|
char *cipher_mode_spec = NULL;
|
|
QCryptoCipherAlgorithm ivcipheralg = 0;
|
|
uint64_t iters;
|
|
|
|
memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts));
|
|
if (!luks_opts.has_iter_time) {
|
|
luks_opts.iter_time = 2000;
|
|
}
|
|
if (!luks_opts.has_cipher_alg) {
|
|
luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256;
|
|
}
|
|
if (!luks_opts.has_cipher_mode) {
|
|
luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS;
|
|
}
|
|
if (!luks_opts.has_ivgen_alg) {
|
|
luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64;
|
|
}
|
|
if (!luks_opts.has_hash_alg) {
|
|
luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256;
|
|
}
|
|
if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
|
|
if (!luks_opts.has_ivgen_hash_alg) {
|
|
luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256;
|
|
luks_opts.has_ivgen_hash_alg = true;
|
|
}
|
|
}
|
|
/* Note we're allowing ivgen_hash_alg to be set even for
|
|
* non-essiv iv generators that don't need a hash. It will
|
|
* be silently ignored, for compatibility with dm-crypt */
|
|
|
|
if (!options->u.luks.key_secret) {
|
|
error_setg(errp, "Parameter '%skey-secret' is required for cipher",
|
|
optprefix ? optprefix : "");
|
|
return -1;
|
|
}
|
|
password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp);
|
|
if (!password) {
|
|
return -1;
|
|
}
|
|
|
|
luks = g_new0(QCryptoBlockLUKS, 1);
|
|
block->opaque = luks;
|
|
|
|
memcpy(luks->header.magic, qcrypto_block_luks_magic,
|
|
QCRYPTO_BLOCK_LUKS_MAGIC_LEN);
|
|
|
|
/* We populate the header in native endianness initially and
|
|
* then convert everything to big endian just before writing
|
|
* it out to disk
|
|
*/
|
|
luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION;
|
|
qcrypto_block_luks_uuid_gen(luks->header.uuid);
|
|
|
|
cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg,
|
|
errp);
|
|
if (!cipher_alg) {
|
|
goto error;
|
|
}
|
|
|
|
cipher_mode = QCryptoCipherMode_lookup[luks_opts.cipher_mode];
|
|
ivgen_alg = QCryptoIVGenAlgorithm_lookup[luks_opts.ivgen_alg];
|
|
if (luks_opts.has_ivgen_hash_alg) {
|
|
ivgen_hash_alg = QCryptoHashAlgorithm_lookup[luks_opts.ivgen_hash_alg];
|
|
cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg,
|
|
ivgen_hash_alg);
|
|
} else {
|
|
cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg);
|
|
}
|
|
hash_alg = QCryptoHashAlgorithm_lookup[luks_opts.hash_alg];
|
|
|
|
|
|
if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) {
|
|
error_setg(errp, "Cipher name '%s' is too long for LUKS header",
|
|
cipher_alg);
|
|
goto error;
|
|
}
|
|
if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) {
|
|
error_setg(errp, "Cipher mode '%s' is too long for LUKS header",
|
|
cipher_mode_spec);
|
|
goto error;
|
|
}
|
|
if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) {
|
|
error_setg(errp, "Hash name '%s' is too long for LUKS header",
|
|
hash_alg);
|
|
goto error;
|
|
}
|
|
|
|
if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
|
|
ivcipheralg = qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg,
|
|
luks_opts.ivgen_hash_alg,
|
|
&local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto error;
|
|
}
|
|
} else {
|
|
ivcipheralg = luks_opts.cipher_alg;
|
|
}
|
|
|
|
strcpy(luks->header.cipher_name, cipher_alg);
|
|
strcpy(luks->header.cipher_mode, cipher_mode_spec);
|
|
strcpy(luks->header.hash_spec, hash_alg);
|
|
|
|
luks->header.key_bytes = qcrypto_cipher_get_key_len(luks_opts.cipher_alg);
|
|
if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) {
|
|
luks->header.key_bytes *= 2;
|
|
}
|
|
|
|
/* Generate the salt used for hashing the master key
|
|
* with PBKDF later
|
|
*/
|
|
if (qcrypto_random_bytes(luks->header.master_key_salt,
|
|
QCRYPTO_BLOCK_LUKS_SALT_LEN,
|
|
errp) < 0) {
|
|
goto error;
|
|
}
|
|
|
|
/* Generate random master key */
|
|
masterkey = g_new0(uint8_t, luks->header.key_bytes);
|
|
if (qcrypto_random_bytes(masterkey,
|
|
luks->header.key_bytes, errp) < 0) {
|
|
goto error;
|
|
}
|
|
|
|
|
|
/* Setup the block device payload encryption objects */
|
|
block->cipher = qcrypto_cipher_new(luks_opts.cipher_alg,
|
|
luks_opts.cipher_mode,
|
|
masterkey, luks->header.key_bytes,
|
|
errp);
|
|
if (!block->cipher) {
|
|
goto error;
|
|
}
|
|
|
|
block->kdfhash = luks_opts.hash_alg;
|
|
block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg,
|
|
luks_opts.cipher_mode);
|
|
block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg,
|
|
ivcipheralg,
|
|
luks_opts.ivgen_hash_alg,
|
|
masterkey, luks->header.key_bytes,
|
|
errp);
|
|
|
|
if (!block->ivgen) {
|
|
goto error;
|
|
}
|
|
|
|
|
|
/* Determine how many iterations we need to hash the master
|
|
* key, in order to have 1 second of compute time used
|
|
*/
|
|
iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg,
|
|
masterkey, luks->header.key_bytes,
|
|
luks->header.master_key_salt,
|
|
QCRYPTO_BLOCK_LUKS_SALT_LEN,
|
|
QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
|
|
&local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto error;
|
|
}
|
|
|
|
if (iters > (ULLONG_MAX / luks_opts.iter_time)) {
|
|
error_setg_errno(errp, ERANGE,
|
|
"PBKDF iterations %llu too large to scale",
|
|
(unsigned long long)iters);
|
|
goto error;
|
|
}
|
|
|
|
/* iter_time was in millis, but count_iters reported for secs */
|
|
iters = iters * luks_opts.iter_time / 1000;
|
|
|
|
/* Why /= 8 ? That matches cryptsetup, but there's no
|
|
* explanation why they chose /= 8... Probably so that
|
|
* if all 8 keyslots are active we only spend 1 second
|
|
* in total time to check all keys */
|
|
iters /= 8;
|
|
if (iters > UINT32_MAX) {
|
|
error_setg_errno(errp, ERANGE,
|
|
"PBKDF iterations %llu larger than %u",
|
|
(unsigned long long)iters, UINT32_MAX);
|
|
goto error;
|
|
}
|
|
iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS);
|
|
luks->header.master_key_iterations = iters;
|
|
|
|
/* Hash the master key, saving the result in the LUKS
|
|
* header. This hash is used when opening the encrypted
|
|
* device to verify that the user password unlocked a
|
|
* valid master key
|
|
*/
|
|
if (qcrypto_pbkdf2(luks_opts.hash_alg,
|
|
masterkey, luks->header.key_bytes,
|
|
luks->header.master_key_salt,
|
|
QCRYPTO_BLOCK_LUKS_SALT_LEN,
|
|
luks->header.master_key_iterations,
|
|
luks->header.master_key_digest,
|
|
QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
|
|
errp) < 0) {
|
|
goto error;
|
|
}
|
|
|
|
|
|
/* Although LUKS has multiple key slots, we're just going
|
|
* to use the first key slot */
|
|
splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES;
|
|
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
|
|
luks->header.key_slots[i].active = i == 0 ?
|
|
QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED :
|
|
QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
|
|
luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
|
|
|
|
/* This calculation doesn't match that shown in the spec,
|
|
* but instead follows the cryptsetup implementation.
|
|
*/
|
|
luks->header.key_slots[i].key_offset =
|
|
(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
|
|
(ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
|
|
(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i);
|
|
}
|
|
|
|
if (qcrypto_random_bytes(luks->header.key_slots[0].salt,
|
|
QCRYPTO_BLOCK_LUKS_SALT_LEN,
|
|
errp) < 0) {
|
|
goto error;
|
|
}
|
|
|
|
/* Again we determine how many iterations are required to
|
|
* hash the user password while consuming 1 second of compute
|
|
* time */
|
|
iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg,
|
|
(uint8_t *)password, strlen(password),
|
|
luks->header.key_slots[0].salt,
|
|
QCRYPTO_BLOCK_LUKS_SALT_LEN,
|
|
luks->header.key_bytes,
|
|
&local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto error;
|
|
}
|
|
|
|
if (iters > (ULLONG_MAX / luks_opts.iter_time)) {
|
|
error_setg_errno(errp, ERANGE,
|
|
"PBKDF iterations %llu too large to scale",
|
|
(unsigned long long)iters);
|
|
goto error;
|
|
}
|
|
|
|
/* iter_time was in millis, but count_iters reported for secs */
|
|
iters = iters * luks_opts.iter_time / 1000;
|
|
|
|
if (iters > UINT32_MAX) {
|
|
error_setg_errno(errp, ERANGE,
|
|
"PBKDF iterations %llu larger than %u",
|
|
(unsigned long long)iters, UINT32_MAX);
|
|
goto error;
|
|
}
|
|
|
|
luks->header.key_slots[0].iterations =
|
|
MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS);
|
|
|
|
|
|
/* Generate a key that we'll use to encrypt the master
|
|
* key, from the user's password
|
|
*/
|
|
slotkey = g_new0(uint8_t, luks->header.key_bytes);
|
|
if (qcrypto_pbkdf2(luks_opts.hash_alg,
|
|
(uint8_t *)password, strlen(password),
|
|
luks->header.key_slots[0].salt,
|
|
QCRYPTO_BLOCK_LUKS_SALT_LEN,
|
|
luks->header.key_slots[0].iterations,
|
|
slotkey, luks->header.key_bytes,
|
|
errp) < 0) {
|
|
goto error;
|
|
}
|
|
|
|
|
|
/* Setup the encryption objects needed to encrypt the
|
|
* master key material
|
|
*/
|
|
cipher = qcrypto_cipher_new(luks_opts.cipher_alg,
|
|
luks_opts.cipher_mode,
|
|
slotkey, luks->header.key_bytes,
|
|
errp);
|
|
if (!cipher) {
|
|
goto error;
|
|
}
|
|
|
|
ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg,
|
|
ivcipheralg,
|
|
luks_opts.ivgen_hash_alg,
|
|
slotkey, luks->header.key_bytes,
|
|
errp);
|
|
if (!ivgen) {
|
|
goto error;
|
|
}
|
|
|
|
/* Before storing the master key, we need to vastly
|
|
* increase its size, as protection against forensic
|
|
* disk data recovery */
|
|
splitkey = g_new0(uint8_t, splitkeylen);
|
|
|
|
if (qcrypto_afsplit_encode(luks_opts.hash_alg,
|
|
luks->header.key_bytes,
|
|
luks->header.key_slots[0].stripes,
|
|
masterkey,
|
|
splitkey,
|
|
errp) < 0) {
|
|
goto error;
|
|
}
|
|
|
|
/* Now we encrypt the split master key with the key generated
|
|
* from the user's password, before storing it */
|
|
if (qcrypto_block_encrypt_helper(cipher, block->niv, ivgen,
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
|
|
0,
|
|
splitkey,
|
|
splitkeylen,
|
|
errp) < 0) {
|
|
goto error;
|
|
}
|
|
|
|
|
|
/* The total size of the LUKS headers is the partition header + key
|
|
* slot headers, rounded up to the nearest sector, combined with
|
|
* the size of each master key material region, also rounded up
|
|
* to the nearest sector */
|
|
luks->header.payload_offset =
|
|
(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
|
|
(ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
|
|
(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) *
|
|
QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
|
|
|
|
block->payload_offset = luks->header.payload_offset *
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
|
|
|
|
/* Reserve header space to match payload offset */
|
|
initfunc(block, block->payload_offset, opaque, &local_err);
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto error;
|
|
}
|
|
|
|
/* Everything on disk uses Big Endian, so flip header fields
|
|
* before writing them */
|
|
cpu_to_be16s(&luks->header.version);
|
|
cpu_to_be32s(&luks->header.payload_offset);
|
|
cpu_to_be32s(&luks->header.key_bytes);
|
|
cpu_to_be32s(&luks->header.master_key_iterations);
|
|
|
|
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
|
|
cpu_to_be32s(&luks->header.key_slots[i].active);
|
|
cpu_to_be32s(&luks->header.key_slots[i].iterations);
|
|
cpu_to_be32s(&luks->header.key_slots[i].key_offset);
|
|
cpu_to_be32s(&luks->header.key_slots[i].stripes);
|
|
}
|
|
|
|
|
|
/* Write out the partition header and key slot headers */
|
|
writefunc(block, 0,
|
|
(const uint8_t *)&luks->header,
|
|
sizeof(luks->header),
|
|
opaque,
|
|
&local_err);
|
|
|
|
/* Delay checking local_err until we've byte-swapped */
|
|
|
|
/* Byte swap the header back to native, in case we need
|
|
* to read it again later */
|
|
be16_to_cpus(&luks->header.version);
|
|
be32_to_cpus(&luks->header.payload_offset);
|
|
be32_to_cpus(&luks->header.key_bytes);
|
|
be32_to_cpus(&luks->header.master_key_iterations);
|
|
|
|
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
|
|
be32_to_cpus(&luks->header.key_slots[i].active);
|
|
be32_to_cpus(&luks->header.key_slots[i].iterations);
|
|
be32_to_cpus(&luks->header.key_slots[i].key_offset);
|
|
be32_to_cpus(&luks->header.key_slots[i].stripes);
|
|
}
|
|
|
|
if (local_err) {
|
|
error_propagate(errp, local_err);
|
|
goto error;
|
|
}
|
|
|
|
/* Write out the master key material, starting at the
|
|
* sector immediately following the partition header. */
|
|
if (writefunc(block,
|
|
luks->header.key_slots[0].key_offset *
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
|
|
splitkey, splitkeylen,
|
|
opaque,
|
|
errp) != splitkeylen) {
|
|
goto error;
|
|
}
|
|
|
|
luks->cipher_alg = luks_opts.cipher_alg;
|
|
luks->cipher_mode = luks_opts.cipher_mode;
|
|
luks->ivgen_alg = luks_opts.ivgen_alg;
|
|
luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg;
|
|
luks->hash_alg = luks_opts.hash_alg;
|
|
|
|
memset(masterkey, 0, luks->header.key_bytes);
|
|
g_free(masterkey);
|
|
memset(slotkey, 0, luks->header.key_bytes);
|
|
g_free(slotkey);
|
|
g_free(splitkey);
|
|
g_free(password);
|
|
g_free(cipher_mode_spec);
|
|
|
|
qcrypto_ivgen_free(ivgen);
|
|
qcrypto_cipher_free(cipher);
|
|
|
|
return 0;
|
|
|
|
error:
|
|
if (masterkey) {
|
|
memset(masterkey, 0, luks->header.key_bytes);
|
|
}
|
|
g_free(masterkey);
|
|
if (slotkey) {
|
|
memset(slotkey, 0, luks->header.key_bytes);
|
|
}
|
|
g_free(slotkey);
|
|
g_free(splitkey);
|
|
g_free(password);
|
|
g_free(cipher_mode_spec);
|
|
|
|
qcrypto_ivgen_free(ivgen);
|
|
qcrypto_cipher_free(cipher);
|
|
|
|
g_free(luks);
|
|
return -1;
|
|
}
|
|
|
|
|
|
static int qcrypto_block_luks_get_info(QCryptoBlock *block,
|
|
QCryptoBlockInfo *info,
|
|
Error **errp)
|
|
{
|
|
QCryptoBlockLUKS *luks = block->opaque;
|
|
QCryptoBlockInfoLUKSSlot *slot;
|
|
QCryptoBlockInfoLUKSSlotList *slots = NULL, **prev = &info->u.luks.slots;
|
|
size_t i;
|
|
|
|
info->u.luks.cipher_alg = luks->cipher_alg;
|
|
info->u.luks.cipher_mode = luks->cipher_mode;
|
|
info->u.luks.ivgen_alg = luks->ivgen_alg;
|
|
if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
|
|
info->u.luks.has_ivgen_hash_alg = true;
|
|
info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg;
|
|
}
|
|
info->u.luks.hash_alg = luks->hash_alg;
|
|
info->u.luks.payload_offset = block->payload_offset;
|
|
info->u.luks.master_key_iters = luks->header.master_key_iterations;
|
|
info->u.luks.uuid = g_strndup((const char *)luks->header.uuid,
|
|
sizeof(luks->header.uuid));
|
|
|
|
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
|
|
slots = g_new0(QCryptoBlockInfoLUKSSlotList, 1);
|
|
*prev = slots;
|
|
|
|
slots->value = slot = g_new0(QCryptoBlockInfoLUKSSlot, 1);
|
|
slot->active = luks->header.key_slots[i].active ==
|
|
QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
|
|
slot->key_offset = luks->header.key_slots[i].key_offset
|
|
* QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
|
|
if (slot->active) {
|
|
slot->has_iters = true;
|
|
slot->iters = luks->header.key_slots[i].iterations;
|
|
slot->has_stripes = true;
|
|
slot->stripes = luks->header.key_slots[i].stripes;
|
|
}
|
|
|
|
prev = &slots->next;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static void qcrypto_block_luks_cleanup(QCryptoBlock *block)
|
|
{
|
|
g_free(block->opaque);
|
|
}
|
|
|
|
|
|
static int
|
|
qcrypto_block_luks_decrypt(QCryptoBlock *block,
|
|
uint64_t startsector,
|
|
uint8_t *buf,
|
|
size_t len,
|
|
Error **errp)
|
|
{
|
|
return qcrypto_block_decrypt_helper(block->cipher,
|
|
block->niv, block->ivgen,
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
|
|
startsector, buf, len, errp);
|
|
}
|
|
|
|
|
|
static int
|
|
qcrypto_block_luks_encrypt(QCryptoBlock *block,
|
|
uint64_t startsector,
|
|
uint8_t *buf,
|
|
size_t len,
|
|
Error **errp)
|
|
{
|
|
return qcrypto_block_encrypt_helper(block->cipher,
|
|
block->niv, block->ivgen,
|
|
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
|
|
startsector, buf, len, errp);
|
|
}
|
|
|
|
|
|
const QCryptoBlockDriver qcrypto_block_driver_luks = {
|
|
.open = qcrypto_block_luks_open,
|
|
.create = qcrypto_block_luks_create,
|
|
.get_info = qcrypto_block_luks_get_info,
|
|
.cleanup = qcrypto_block_luks_cleanup,
|
|
.decrypt = qcrypto_block_luks_decrypt,
|
|
.encrypt = qcrypto_block_luks_encrypt,
|
|
.has_format = qcrypto_block_luks_has_format,
|
|
};
|