diff options
Diffstat (limited to 'qemu/crypto/block-luks.c')
| -rw-r--r-- | qemu/crypto/block-luks.c | 1329 |
1 files changed, 0 insertions, 1329 deletions
diff --git a/qemu/crypto/block-luks.c b/qemu/crypto/block-luks.c deleted file mode 100644 index 439f89230..000000000 --- a/qemu/crypto/block-luks.c +++ /dev/null @@ -1,1329 +0,0 @@ -/* - * 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 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 "crypto/block-luks.h" - -#include "crypto/hash.h" -#include "crypto/afsplit.h" -#include "crypto/pbkdf.h" -#include "crypto/secret.h" -#include "crypto/random.h" - -#ifdef CONFIG_UUID -#include <uuid/uuid.h> -#endif - -#include "qemu/coroutine.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 QCryptoBlockLUKS QCryptoBlockLUKS; -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 - -static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = { - 'L', 'U', 'K', 'S', 0xBA, 0xBE -}; - -typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap; -struct QCryptoBlockLUKSNameMap { - const char *name; - int id; -}; - -typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap; -struct QCryptoBlockLUKSCipherSizeMap { - uint32_t key_bytes; - int id; -}; -typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap; -struct QCryptoBlockLUKSCipherNameMap { - const char *name; - const QCryptoBlockLUKSCipherSizeMap *sizes; -}; - - -static const QCryptoBlockLUKSCipherSizeMap -qcrypto_block_luks_cipher_size_map_aes[] = { - { 16, QCRYPTO_CIPHER_ALG_AES_128 }, - { 24, QCRYPTO_CIPHER_ALG_AES_192 }, - { 32, QCRYPTO_CIPHER_ALG_AES_256 }, - { 0, 0 }, -}; - -static const QCryptoBlockLUKSCipherSizeMap -qcrypto_block_luks_cipher_size_map_cast5[] = { - { 16, QCRYPTO_CIPHER_ALG_CAST5_128 }, - { 0, 0 }, -}; - -static const QCryptoBlockLUKSCipherSizeMap -qcrypto_block_luks_cipher_size_map_serpent[] = { - { 16, QCRYPTO_CIPHER_ALG_SERPENT_128 }, - { 24, QCRYPTO_CIPHER_ALG_SERPENT_192 }, - { 32, QCRYPTO_CIPHER_ALG_SERPENT_256 }, - { 0, 0 }, -}; - -static const QCryptoBlockLUKSCipherSizeMap -qcrypto_block_luks_cipher_size_map_twofish[] = { - { 16, QCRYPTO_CIPHER_ALG_TWOFISH_128 }, - { 24, QCRYPTO_CIPHER_ALG_TWOFISH_192 }, - { 32, QCRYPTO_CIPHER_ALG_TWOFISH_256 }, - { 0, 0 }, -}; - -static const QCryptoBlockLUKSCipherNameMap -qcrypto_block_luks_cipher_name_map[] = { - { "aes", qcrypto_block_luks_cipher_size_map_aes }, - { "cast5", qcrypto_block_luks_cipher_size_map_cast5 }, - { "serpent", qcrypto_block_luks_cipher_size_map_serpent }, - { "twofish", qcrypto_block_luks_cipher_size_map_twofish }, -}; - - -/* - * 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; - /* number of anti-forensic stripes */ - uint32_t stripes; -} QEMU_PACKED; - -QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48); - - -/* - * 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; - - /* Number of key bytes */ - uint32_t key_bytes; - - /* 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]; -} QEMU_PACKED; - -QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592); - - -struct QCryptoBlockLUKS { - QCryptoBlockLUKSHeader header; -}; - - -static int qcrypto_block_luks_cipher_name_lookup(const char *name, - QCryptoCipherMode mode, - uint32_t key_bytes, - Error **errp) -{ - const QCryptoBlockLUKSCipherNameMap *map = - qcrypto_block_luks_cipher_name_map; - size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map); - size_t i, j; - - if (mode == QCRYPTO_CIPHER_MODE_XTS) { - key_bytes /= 2; - } - - for (i = 0; i < maplen; i++) { - if (!g_str_equal(map[i].name, name)) { - continue; - } - for (j = 0; j < map[i].sizes[j].key_bytes; j++) { - if (map[i].sizes[j].key_bytes == key_bytes) { - return map[i].sizes[j].id; - } - } - } - - error_setg(errp, "Algorithm %s with key size %d bytes not supported", - name, key_bytes); - return 0; -} - -static const char * -qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgorithm alg, - Error **errp) -{ - const QCryptoBlockLUKSCipherNameMap *map = - qcrypto_block_luks_cipher_name_map; - size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map); - size_t i, j; - for (i = 0; i < maplen; i++) { - for (j = 0; j < map[i].sizes[j].key_bytes; j++) { - if (map[i].sizes[j].id == alg) { - return map[i].name; - } - } - } - - error_setg(errp, "Algorithm '%s' not supported", - QCryptoCipherAlgorithm_lookup[alg]); - return NULL; -} - -/* XXX replace with qapi_enum_parse() in future, when we can - * make that function emit a more friendly error message */ -static int qcrypto_block_luks_name_lookup(const char *name, - const char *const *map, - size_t maplen, - const char *type, - Error **errp) -{ - size_t i; - for (i = 0; i < maplen; i++) { - if (g_str_equal(map[i], name)) { - return i; - } - } - - error_setg(errp, "%s %s not supported", type, name); - return 0; -} - -#define qcrypto_block_luks_cipher_mode_lookup(name, errp) \ - qcrypto_block_luks_name_lookup(name, \ - QCryptoCipherMode_lookup, \ - QCRYPTO_CIPHER_MODE__MAX, \ - "Cipher mode", \ - errp) - -#define qcrypto_block_luks_hash_name_lookup(name, errp) \ - qcrypto_block_luks_name_lookup(name, \ - QCryptoHashAlgorithm_lookup, \ - QCRYPTO_HASH_ALG__MAX, \ - "Hash algorithm", \ - errp) - -#define qcrypto_block_luks_ivgen_name_lookup(name, errp) \ - qcrypto_block_luks_name_lookup(name, \ - QCryptoIVGenAlgorithm_lookup, \ - QCRYPTO_IVGEN_ALG__MAX, \ - "IV generator", \ - errp) - - -static bool -qcrypto_block_luks_has_format(const uint8_t *buf, - size_t buf_size) -{ - const QCryptoBlockLUKSHeader *luks_header = (const void *)buf; - - if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) && - memcmp(luks_header->magic, qcrypto_block_luks_magic, - QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 && - be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) { - return true; - } else { - return false; - } -} - - -/** - * Deal with a quirk of dm-crypt usage of ESSIV. - * - * When calculating ESSIV IVs, the cipher length used by ESSIV - * may be different from the cipher length used for the block - * encryption, becauses dm-crypt uses the hash digest length - * as the key size. ie, if you have AES 128 as the block cipher - * and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as - * the cipher since that gets a key length matching the digest - * size, not AES 128 with truncated digest as might be imagined - */ -static QCryptoCipherAlgorithm -qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm cipher, - QCryptoHashAlgorithm hash, - Error **errp) -{ - size_t digestlen = qcrypto_hash_digest_len(hash); - size_t keylen = qcrypto_cipher_get_key_len(cipher); - if (digestlen == keylen) { - return cipher; - } - - switch (cipher) { - case QCRYPTO_CIPHER_ALG_AES_128: - case QCRYPTO_CIPHER_ALG_AES_192: - case QCRYPTO_CIPHER_ALG_AES_256: - if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_AES_128)) { - return QCRYPTO_CIPHER_ALG_AES_128; - } else if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_AES_192)) { - return QCRYPTO_CIPHER_ALG_AES_192; - } else if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_AES_256)) { - return QCRYPTO_CIPHER_ALG_AES_256; - } else { - error_setg(errp, "No AES cipher with key size %zu available", - digestlen); - return 0; - } - break; - case QCRYPTO_CIPHER_ALG_SERPENT_128: - case QCRYPTO_CIPHER_ALG_SERPENT_192: - case QCRYPTO_CIPHER_ALG_SERPENT_256: - if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_SERPENT_128)) { - return QCRYPTO_CIPHER_ALG_SERPENT_128; - } else if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_SERPENT_192)) { - return QCRYPTO_CIPHER_ALG_SERPENT_192; - } else if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_SERPENT_256)) { - return QCRYPTO_CIPHER_ALG_SERPENT_256; - } else { - error_setg(errp, "No Serpent cipher with key size %zu available", - digestlen); - return 0; - } - break; - case QCRYPTO_CIPHER_ALG_TWOFISH_128: - case QCRYPTO_CIPHER_ALG_TWOFISH_192: - case QCRYPTO_CIPHER_ALG_TWOFISH_256: - if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_TWOFISH_128)) { - return QCRYPTO_CIPHER_ALG_TWOFISH_128; - } else if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_TWOFISH_192)) { - return QCRYPTO_CIPHER_ALG_TWOFISH_192; - } else if (digestlen == qcrypto_cipher_get_key_len( - QCRYPTO_CIPHER_ALG_TWOFISH_256)) { - return QCRYPTO_CIPHER_ALG_TWOFISH_256; - } else { - error_setg(errp, "No Twofish cipher with key size %zu available", - digestlen); - return 0; - } - break; - default: - error_setg(errp, "Cipher %s not supported with essiv", - QCryptoCipherAlgorithm_lookup[cipher]); - return 0; - } -} - -/* - * Given a key slot, and user password, this will attempt to unlock - * the master encryption key from the key slot. - * - * Returns: - * 0 if the key slot is disabled, or key could not be decrypted - * with the provided password - * 1 if the key slot is enabled, and key decrypted successfully - * with the provided password - * -1 if a fatal error occurred loading the key - */ -static int -qcrypto_block_luks_load_key(QCryptoBlock *block, - QCryptoBlockLUKSKeySlot *slot, - 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; - uint8_t *splitkey; - size_t splitkeylen; - uint8_t *possiblekey; - int ret = -1; - ssize_t rv; - QCryptoCipher *cipher = NULL; - uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; - QCryptoIVGen *ivgen = NULL; - size_t niv; - - if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) { - return 0; - } - - splitkeylen = masterkeylen * slot->stripes; - splitkey = g_new0(uint8_t, splitkeylen); - possiblekey = g_new0(uint8_t, masterkeylen); - - /* - * 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, - errp, - opaque); - 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, - 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 'key-secret' is required for cipher"); - 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), - errp, - opaque); - 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) { - ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg, - ivhash, - &local_err); - if (local_err) { - ret = -ENOTSUP; - error_propagate(errp, local_err); - goto fail; - } - } else { - 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; - - 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 int -qcrypto_block_luks_uuid_gen(uint8_t *uuidstr, Error **errp) -{ -#ifdef CONFIG_UUID - uuid_t uuid; - uuid_generate(uuid); - uuid_unparse(uuid, (char *)uuidstr); - return 0; -#else - error_setg(errp, "Unable to generate uuids on this platform"); - return -1; -#endif -} - -static int -qcrypto_block_luks_create(QCryptoBlock *block, - QCryptoBlockCreateOptions *options, - 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; - - memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts)); - 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 (!options->u.luks.key_secret) { - error_setg(errp, "Parameter 'key-secret' is required for cipher"); - 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; - if (qcrypto_block_luks_uuid_gen(luks->header.uuid, - errp) < 0) { - goto error; - } - - 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 - */ - luks->header.master_key_iterations = - qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, - masterkey, luks->header.key_bytes, - luks->header.master_key_salt, - QCRYPTO_BLOCK_LUKS_SALT_LEN, - &local_err); - if (local_err) { - error_propagate(errp, local_err); - goto error; - } - - /* 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 */ - luks->header.master_key_iterations /= 8; - luks->header.master_key_iterations = MAX( - luks->header.master_key_iterations, - QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_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(((splitkeylen + (QCRYPTO_BLOCK_LUKS_SECTOR_SIZE - 1)) / - 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 */ - luks->header.key_slots[0].iterations = - qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, - (uint8_t *)password, strlen(password), - luks->header.key_slots[0].salt, - QCRYPTO_BLOCK_LUKS_SALT_LEN, - &local_err); - if (local_err) { - error_propagate(errp, local_err); - goto error; - } - /* Why /= 2 ? That matches cryptsetup, but there's no - * explanation why they chose /= 2... */ - luks->header.key_slots[0].iterations /= 2; - luks->header.key_slots[0].iterations = MAX( - luks->header.key_slots[0].iterations, - 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(((splitkeylen + (QCRYPTO_BLOCK_LUKS_SECTOR_SIZE - 1)) / - 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, &local_err, opaque); - 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), - &local_err, - opaque); - - /* 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, - errp, - opaque) != splitkeylen) { - goto error; - } - - 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 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, - .cleanup = qcrypto_block_luks_cleanup, - .decrypt = qcrypto_block_luks_decrypt, - .encrypt = qcrypto_block_luks_encrypt, - .has_format = qcrypto_block_luks_has_format, -}; |