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, opaque, 0, (uint8_t *)&luks->header, sizeof(luks->header), 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; }