diff options
Diffstat (limited to 'crypto/block-qcow.c')
| -rw-r--r-- | crypto/block-qcow.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/crypto/block-qcow.c b/crypto/block-qcow.c new file mode 100644 index 0000000000..9f378e8635 --- /dev/null +++ b/crypto/block-qcow.c @@ -0,0 +1,173 @@ +/* + * QEMU Crypto block device encryption QCow/QCow2 AES-CBC 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/>. + * + */ + +/* + * Note that the block encryption implemented in this file is broken + * by design. This exists only to allow data to be liberated from + * existing qcow[2] images and should not be used in any new areas. + */ + +#include "qemu/osdep.h" + +#include "crypto/block-qcow.h" +#include "crypto/secret.h" + +#define QCRYPTO_BLOCK_QCOW_SECTOR_SIZE 512 + + +static bool +qcrypto_block_qcow_has_format(const uint8_t *buf G_GNUC_UNUSED, + size_t buf_size G_GNUC_UNUSED) +{ + return false; +} + + +static int +qcrypto_block_qcow_init(QCryptoBlock *block, + const char *keysecret, + Error **errp) +{ + char *password; + int ret; + uint8_t keybuf[16]; + int len; + + memset(keybuf, 0, 16); + + password = qcrypto_secret_lookup_as_utf8(keysecret, errp); + if (!password) { + return -1; + } + + len = strlen(password); + memcpy(keybuf, password, MIN(len, sizeof(keybuf))); + g_free(password); + + block->niv = qcrypto_cipher_get_iv_len(QCRYPTO_CIPHER_ALG_AES_128, + QCRYPTO_CIPHER_MODE_CBC); + block->ivgen = qcrypto_ivgen_new(QCRYPTO_IVGEN_ALG_PLAIN64, + 0, 0, NULL, 0, errp); + if (!block->ivgen) { + ret = -ENOTSUP; + goto fail; + } + + block->cipher = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_128, + QCRYPTO_CIPHER_MODE_CBC, + keybuf, G_N_ELEMENTS(keybuf), + errp); + if (!block->cipher) { + ret = -ENOTSUP; + goto fail; + } + + block->payload_offset = 0; + + return 0; + + fail: + qcrypto_cipher_free(block->cipher); + qcrypto_ivgen_free(block->ivgen); + return ret; +} + + +static int +qcrypto_block_qcow_open(QCryptoBlock *block, + QCryptoBlockOpenOptions *options, + QCryptoBlockReadFunc readfunc G_GNUC_UNUSED, + void *opaque G_GNUC_UNUSED, + unsigned int flags, + Error **errp) +{ + if (flags & QCRYPTO_BLOCK_OPEN_NO_IO) { + return 0; + } else { + if (!options->u.qcow.key_secret) { + error_setg(errp, + "Parameter 'key-secret' is required for cipher"); + return -1; + } + return qcrypto_block_qcow_init(block, + options->u.qcow.key_secret, errp); + } +} + + +static int +qcrypto_block_qcow_create(QCryptoBlock *block, + QCryptoBlockCreateOptions *options, + QCryptoBlockInitFunc initfunc G_GNUC_UNUSED, + QCryptoBlockWriteFunc writefunc G_GNUC_UNUSED, + void *opaque G_GNUC_UNUSED, + Error **errp) +{ + if (!options->u.qcow.key_secret) { + error_setg(errp, "Parameter 'key-secret' is required for cipher"); + return -1; + } + /* QCow2 has no special header, since everything is hardwired */ + return qcrypto_block_qcow_init(block, options->u.qcow.key_secret, errp); +} + + +static void +qcrypto_block_qcow_cleanup(QCryptoBlock *block) +{ +} + + +static int +qcrypto_block_qcow_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_QCOW_SECTOR_SIZE, + startsector, buf, len, errp); +} + + +static int +qcrypto_block_qcow_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_QCOW_SECTOR_SIZE, + startsector, buf, len, errp); +} + + +const QCryptoBlockDriver qcrypto_block_driver_qcow = { + .open = qcrypto_block_qcow_open, + .create = qcrypto_block_qcow_create, + .cleanup = qcrypto_block_qcow_cleanup, + .decrypt = qcrypto_block_qcow_decrypt, + .encrypt = qcrypto_block_qcow_encrypt, + .has_format = qcrypto_block_qcow_has_format, +}; |