LXR qemu/crypto/block-luks-priv.h

   1/*
   2 * QEMU Crypto block device encryption LUKS format
   3 *
   4 * Copyright (c) 2015-2016 Red Hat, Inc.
   5 *
   6 * This library is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU Lesser General Public
   8 * License as published by the Free Software Foundation; either
   9 * version 2.1 of the License, or (at your option) any later version.
  10 *
  11 * This library is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * Lesser General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU Lesser General Public
  17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18 *
  19 */
  20
  21#include "qemu/osdep.h"
  22#include "qapi/error.h"
  23#include "qemu/bswap.h"
  24
  25#include "block-luks.h"
  26
  27#include "crypto/hash.h"
  28#include "crypto/afsplit.h"
  29#include "crypto/pbkdf.h"
  30#include "crypto/secret.h"
  31#include "crypto/random.h"
  32#include "qemu/uuid.h"
  33
  34#include "qemu/coroutine.h"
  35#include "qemu/bitmap.h"
  36
  37/*
  38 * Reference for the LUKS format implemented here is
  39 *
  40 *   docs/on-disk-format.pdf
  41 *
  42 * in 'cryptsetup' package source code
  43 *
  44 * This file implements the 1.2.1 specification, dated
  45 * Oct 16, 2011.
  46 */
  47
  48typedef struct QCryptoBlockLUKSHeader QCryptoBlockLUKSHeader;
  49typedef struct QCryptoBlockLUKSKeySlot QCryptoBlockLUKSKeySlot;
  50
  51
  52/* The following constants are all defined by the LUKS spec */
  53#define QCRYPTO_BLOCK_LUKS_VERSION 1
  54
  55#define QCRYPTO_BLOCK_LUKS_MAGIC_LEN 6
  56#define QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN 32
  57#define QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN 32
  58#define QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN 32
  59#define QCRYPTO_BLOCK_LUKS_DIGEST_LEN 20
  60#define QCRYPTO_BLOCK_LUKS_SALT_LEN 32
  61#define QCRYPTO_BLOCK_LUKS_UUID_LEN 40
  62#define QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS 8
  63#define QCRYPTO_BLOCK_LUKS_STRIPES 4000
  64#define QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS 1000
  65#define QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS 1000
  66#define QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET 4096
  67
  68#define QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED 0x0000DEAD
  69#define QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED 0x00AC71F3
  70
  71#define QCRYPTO_BLOCK_LUKS_SECTOR_SIZE 512LL
  72
  73#define QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS 2000
  74#define QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS 40
  75
  76static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = {
  77    'L', 'U', 'K', 'S', 0xBA, 0xBE
  78};
  79
  80/*
  81 * This struct is written to disk in big-endian format,
  82 * but operated upon in native-endian format.
  83 */
  84struct QCryptoBlockLUKSKeySlot {
  85    /* state of keyslot, enabled/disable */
  86    uint32_t active;
  87    /* iterations for PBKDF2 */
  88    uint32_t iterations;
  89    /* salt for PBKDF2 */
  90    uint8_t salt[QCRYPTO_BLOCK_LUKS_SALT_LEN];
  91    /* start sector of key material */
  92    uint32_t key_offset_sector;
  93    /* number of anti-forensic stripes */
  94    uint32_t stripes;
  95};
  96
  97/*
  98 * This struct is written to disk in big-endian format,
  99 * but operated upon in native-endian format.
 100 */
 101struct QCryptoBlockLUKSHeader {
 102    /* 'L', 'U', 'K', 'S', '0xBA', '0xBE' */
 103    char magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN];
 104
 105    /* LUKS version, currently 1 */
 106    uint16_t version;
 107
 108    /* cipher name specification (aes, etc) */
 109    char cipher_name[QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN];
 110
 111    /* cipher mode specification (cbc-plain, xts-essiv:sha256, etc) */
 112    char cipher_mode[QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN];
 113
 114    /* hash specification (sha256, etc) */
 115    char hash_spec[QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN];
 116
 117    /* start offset of the volume data (in 512 byte sectors) */
 118    uint32_t payload_offset_sector;
 119
 120    /* Number of key bytes */
 121    uint32_t master_key_len;
 122
 123    /* master key checksum after PBKDF2 */
 124    uint8_t master_key_digest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN];
 125
 126    /* salt for master key PBKDF2 */
 127    uint8_t master_key_salt[QCRYPTO_BLOCK_LUKS_SALT_LEN];
 128
 129    /* iterations for master key PBKDF2 */
 130    uint32_t master_key_iterations;
 131
 132    /* UUID of the partition in standard ASCII representation */
 133    uint8_t uuid[QCRYPTO_BLOCK_LUKS_UUID_LEN];
 134
 135    /* key slots */
 136    QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS];
 137};
 138
 139
 140void
 141qcrypto_block_luks_to_disk_endian(QCryptoBlockLUKSHeader *hdr);
 142void
 143qcrypto_block_luks_from_disk_endian(QCryptoBlockLUKSHeader *hdr);
 144