diff options
| -rw-r--r-- | crypto/block-luks.c | 223 |
1 files changed, 125 insertions, 98 deletions
diff --git a/crypto/block-luks.c b/crypto/block-luks.c index 47371edf13..fa799fd21d 100644 --- a/crypto/block-luks.c +++ b/crypto/block-luks.c @@ -501,6 +501,129 @@ qcrypto_block_luks_load_header(QCryptoBlock *block, } /* + * Does basic sanity checks on the LUKS header + */ +static int +qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks, Error **errp) +{ + if (memcmp(luks->header.magic, qcrypto_block_luks_magic, + QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { + error_setg(errp, "Volume is not in LUKS format"); + return -1; + } + + if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { + error_setg(errp, "LUKS version %" PRIu32 " is not supported", + luks->header.version); + return -1; + } + return 0; +} + +/* + * Parses the crypto parameters that are stored in the LUKS header + */ + +static int +qcrypto_block_luks_parse_header(QCryptoBlockLUKS *luks, Error **errp) +{ + g_autofree char *cipher_mode = g_strdup(luks->header.cipher_mode); + char *ivgen_name, *ivhash_name; + Error *local_err = NULL; + + /* + * 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(cipher_mode, '-'); + if (!ivgen_name) { + error_setg(errp, "Unexpected cipher mode string format %s", + luks->header.cipher_mode); + return -1; + } + *ivgen_name = '\0'; + ivgen_name++; + + ivhash_name = strchr(ivgen_name, ':'); + if (!ivhash_name) { + luks->ivgen_hash_alg = 0; + } else { + *ivhash_name = '\0'; + ivhash_name++; + + luks->ivgen_hash_alg = qcrypto_block_luks_hash_name_lookup(ivhash_name, + &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -1; + } + } + + luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode, + &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -1; + } + + luks->cipher_alg = + qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, + luks->cipher_mode, + luks->header.master_key_len, + &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -1; + } + + luks->hash_alg = + qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, + &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -1; + } + + luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, + &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -1; + } + + if (luks->ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { + if (!ivhash_name) { + error_setg(errp, "Missing IV generator hash specification"); + return -1; + } + luks->ivgen_cipher_alg = + qcrypto_block_luks_essiv_cipher(luks->cipher_alg, + luks->ivgen_hash_alg, + &local_err); + if (local_err) { + error_propagate(errp, local_err); + return -1; + } + } 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 + */ + luks->ivgen_cipher_alg = luks->cipher_alg; + } + return 0; +} + +/* * Given a key slot, and user password, this will attempt to unlock * the master encryption key from the key slot. * @@ -712,11 +835,8 @@ qcrypto_block_luks_open(QCryptoBlock *block, Error **errp) { QCryptoBlockLUKS *luks = NULL; - Error *local_err = NULL; g_autofree uint8_t *masterkey = NULL; - char *ivgen_name, *ivhash_name; g_autofree char *password = NULL; - g_autofree char *cipher_mode = NULL; if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { if (!options->u.luks.key_secret) { @@ -738,107 +858,14 @@ qcrypto_block_luks_open(QCryptoBlock *block, goto fail; } - if (memcmp(luks->header.magic, qcrypto_block_luks_magic, - QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { - error_setg(errp, "Volume is not in LUKS format"); - goto fail; - } - if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { - error_setg(errp, "LUKS version %" PRIu32 " is not supported", - luks->header.version); - goto fail; - } - - cipher_mode = g_strdup(luks->header.cipher_mode); - - /* - * 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(cipher_mode, '-'); - if (!ivgen_name) { - error_setg(errp, "Unexpected cipher mode string format %s", - cipher_mode); - goto fail; - } - *ivgen_name = '\0'; - ivgen_name++; - - ivhash_name = strchr(ivgen_name, ':'); - if (!ivhash_name) { - luks->ivgen_hash_alg = 0; - } else { - *ivhash_name = '\0'; - ivhash_name++; - - luks->ivgen_hash_alg = qcrypto_block_luks_hash_name_lookup(ivhash_name, - &local_err); - if (local_err) { - error_propagate(errp, local_err); - goto fail; - } - } - - luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode, - &local_err); - if (local_err) { - error_propagate(errp, local_err); - goto fail; - } - - luks->cipher_alg = - qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, - luks->cipher_mode, - luks->header.master_key_len, - &local_err); - if (local_err) { - error_propagate(errp, local_err); - goto fail; - } - - luks->hash_alg = - qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, - &local_err); - if (local_err) { - error_propagate(errp, local_err); + if (qcrypto_block_luks_check_header(luks, errp) < 0) { goto fail; } - luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, - &local_err); - if (local_err) { - error_propagate(errp, local_err); + if (qcrypto_block_luks_parse_header(luks, errp) < 0) { goto fail; } - if (luks->ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { - if (!ivhash_name) { - error_setg(errp, "Missing IV generator hash specification"); - goto fail; - } - luks->ivgen_cipher_alg = - qcrypto_block_luks_essiv_cipher(luks->cipher_alg, - luks->ivgen_hash_alg, - &local_err); - if (local_err) { - 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 - */ - luks->ivgen_cipher_alg = luks->cipher_alg; - } - 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. |