qemu

FORK: QEMU emulator
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block-luks-priv.h (4326B)

      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 
     48 typedef struct QCryptoBlockLUKSHeader QCryptoBlockLUKSHeader;
     49 typedef 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 
     76 static 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  */
     84 struct 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  */
    101 struct 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 
    140 void
    141 qcrypto_block_luks_to_disk_endian(QCryptoBlockLUKSHeader *hdr);
    142 void
    143 qcrypto_block_luks_from_disk_endian(QCryptoBlockLUKSHeader *hdr);