mirror of
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crypto: add block encryption framework
Add a generic framework for supporting different block encryption formats. Upon instantiating a QCryptoBlock object, it will read the encryption header and extract the encryption keys. It is then possible to call methods to encrypt/decrypt data buffers. There is also a mode whereby it will create/initialize a new encryption header on a previously unformatted volume. The initial framework comes with support for the legacy QCow AES based encryption. This enables code in the QCow driver to be consolidated later. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This commit is contained in:
Daniel P. Berrange
parent
eaec903c5b
commit
7d9690148a
10 changed files with 1095 additions and 0 deletions
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@ -19,6 +19,8 @@ crypto-obj-y += ivgen-plain.o
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crypto-obj-y += ivgen-plain64.o
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crypto-obj-y += afsplit.o
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crypto-obj-y += xts.o
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crypto-obj-y += block.o
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crypto-obj-y += block-qcow.o
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# Let the userspace emulators avoid linking gnutls/etc
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crypto-aes-obj-y = aes.o
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173
crypto/block-qcow.c
Normal file
173
crypto/block-qcow.c
Normal file
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@ -0,0 +1,173 @@
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/*
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* QEMU Crypto block device encryption QCow/QCow2 AES-CBC format
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*
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* Copyright (c) 2015-2016 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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/*
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* Note that the block encryption implemented in this file is broken
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* by design. This exists only to allow data to be liberated from
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* existing qcow[2] images and should not be used in any new areas.
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*/
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#include "qemu/osdep.h"
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#include "crypto/block-qcow.h"
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#include "crypto/secret.h"
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#define QCRYPTO_BLOCK_QCOW_SECTOR_SIZE 512
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static bool
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qcrypto_block_qcow_has_format(const uint8_t *buf G_GNUC_UNUSED,
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size_t buf_size G_GNUC_UNUSED)
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{
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return false;
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}
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static int
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qcrypto_block_qcow_init(QCryptoBlock *block,
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const char *keysecret,
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Error **errp)
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{
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char *password;
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int ret;
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uint8_t keybuf[16];
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int len;
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memset(keybuf, 0, 16);
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password = qcrypto_secret_lookup_as_utf8(keysecret, errp);
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if (!password) {
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return -1;
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}
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len = strlen(password);
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memcpy(keybuf, password, MIN(len, sizeof(keybuf)));
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g_free(password);
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block->niv = qcrypto_cipher_get_iv_len(QCRYPTO_CIPHER_ALG_AES_128,
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QCRYPTO_CIPHER_MODE_CBC);
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block->ivgen = qcrypto_ivgen_new(QCRYPTO_IVGEN_ALG_PLAIN64,
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0, 0, NULL, 0, errp);
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if (!block->ivgen) {
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ret = -ENOTSUP;
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goto fail;
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}
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block->cipher = qcrypto_cipher_new(QCRYPTO_CIPHER_ALG_AES_128,
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QCRYPTO_CIPHER_MODE_CBC,
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keybuf, G_N_ELEMENTS(keybuf),
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errp);
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if (!block->cipher) {
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ret = -ENOTSUP;
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goto fail;
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}
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block->payload_offset = 0;
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return 0;
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fail:
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qcrypto_cipher_free(block->cipher);
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qcrypto_ivgen_free(block->ivgen);
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return ret;
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}
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static int
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qcrypto_block_qcow_open(QCryptoBlock *block,
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QCryptoBlockOpenOptions *options,
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QCryptoBlockReadFunc readfunc G_GNUC_UNUSED,
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void *opaque G_GNUC_UNUSED,
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unsigned int flags,
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Error **errp)
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{
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if (flags & QCRYPTO_BLOCK_OPEN_NO_IO) {
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return 0;
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} else {
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if (!options->u.qcow.key_secret) {
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error_setg(errp,
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"Parameter 'key-secret' is required for cipher");
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return -1;
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}
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return qcrypto_block_qcow_init(block,
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options->u.qcow.key_secret, errp);
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}
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}
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static int
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qcrypto_block_qcow_create(QCryptoBlock *block,
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QCryptoBlockCreateOptions *options,
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QCryptoBlockInitFunc initfunc G_GNUC_UNUSED,
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QCryptoBlockWriteFunc writefunc G_GNUC_UNUSED,
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void *opaque G_GNUC_UNUSED,
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Error **errp)
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{
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if (!options->u.qcow.key_secret) {
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error_setg(errp, "Parameter 'key-secret' is required for cipher");
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return -1;
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}
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/* QCow2 has no special header, since everything is hardwired */
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return qcrypto_block_qcow_init(block, options->u.qcow.key_secret, errp);
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}
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static void
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qcrypto_block_qcow_cleanup(QCryptoBlock *block)
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{
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}
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static int
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qcrypto_block_qcow_decrypt(QCryptoBlock *block,
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uint64_t startsector,
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uint8_t *buf,
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size_t len,
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Error **errp)
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{
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return qcrypto_block_decrypt_helper(block->cipher,
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block->niv, block->ivgen,
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QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
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startsector, buf, len, errp);
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}
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static int
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qcrypto_block_qcow_encrypt(QCryptoBlock *block,
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uint64_t startsector,
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uint8_t *buf,
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size_t len,
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Error **errp)
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{
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return qcrypto_block_encrypt_helper(block->cipher,
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block->niv, block->ivgen,
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QCRYPTO_BLOCK_QCOW_SECTOR_SIZE,
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startsector, buf, len, errp);
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}
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const QCryptoBlockDriver qcrypto_block_driver_qcow = {
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.open = qcrypto_block_qcow_open,
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.create = qcrypto_block_qcow_create,
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.cleanup = qcrypto_block_qcow_cleanup,
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.decrypt = qcrypto_block_qcow_decrypt,
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.encrypt = qcrypto_block_qcow_encrypt,
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.has_format = qcrypto_block_qcow_has_format,
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};
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28
crypto/block-qcow.h
Normal file
28
crypto/block-qcow.h
Normal file
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@ -0,0 +1,28 @@
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/*
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* QEMU Crypto block device encryption QCow/QCow2 AES-CBC format
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*
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* Copyright (c) 2015-2016 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#ifndef QCRYPTO_BLOCK_QCOW_H__
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#define QCRYPTO_BLOCK_QCOW_H__
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#include "crypto/blockpriv.h"
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extern const QCryptoBlockDriver qcrypto_block_driver_qcow;
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#endif /* QCRYPTO_BLOCK_QCOW_H__ */
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258
crypto/block.c
Normal file
258
crypto/block.c
Normal file
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@ -0,0 +1,258 @@
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/*
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* QEMU Crypto block device encryption
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*
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* Copyright (c) 2015-2016 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "qemu/osdep.h"
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#include "crypto/blockpriv.h"
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#include "crypto/block-qcow.h"
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static const QCryptoBlockDriver *qcrypto_block_drivers[] = {
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[Q_CRYPTO_BLOCK_FORMAT_QCOW] = &qcrypto_block_driver_qcow,
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};
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bool qcrypto_block_has_format(QCryptoBlockFormat format,
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const uint8_t *buf,
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size_t len)
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{
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const QCryptoBlockDriver *driver;
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if (format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
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!qcrypto_block_drivers[format]) {
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return false;
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}
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driver = qcrypto_block_drivers[format];
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return driver->has_format(buf, len);
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}
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QCryptoBlock *qcrypto_block_open(QCryptoBlockOpenOptions *options,
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QCryptoBlockReadFunc readfunc,
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void *opaque,
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unsigned int flags,
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Error **errp)
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{
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QCryptoBlock *block = g_new0(QCryptoBlock, 1);
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block->format = options->format;
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if (options->format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
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!qcrypto_block_drivers[options->format]) {
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error_setg(errp, "Unsupported block driver %d", options->format);
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g_free(block);
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return NULL;
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}
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block->driver = qcrypto_block_drivers[options->format];
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if (block->driver->open(block, options,
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readfunc, opaque, flags, errp) < 0) {
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g_free(block);
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return NULL;
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}
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return block;
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}
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QCryptoBlock *qcrypto_block_create(QCryptoBlockCreateOptions *options,
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QCryptoBlockInitFunc initfunc,
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QCryptoBlockWriteFunc writefunc,
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void *opaque,
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Error **errp)
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{
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QCryptoBlock *block = g_new0(QCryptoBlock, 1);
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block->format = options->format;
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if (options->format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
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!qcrypto_block_drivers[options->format]) {
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error_setg(errp, "Unsupported block driver %d", options->format);
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g_free(block);
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return NULL;
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}
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block->driver = qcrypto_block_drivers[options->format];
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if (block->driver->create(block, options, initfunc,
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writefunc, opaque, errp) < 0) {
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g_free(block);
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return NULL;
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}
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return block;
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}
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int qcrypto_block_decrypt(QCryptoBlock *block,
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uint64_t startsector,
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uint8_t *buf,
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size_t len,
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Error **errp)
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{
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return block->driver->decrypt(block, startsector, buf, len, errp);
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}
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int qcrypto_block_encrypt(QCryptoBlock *block,
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uint64_t startsector,
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uint8_t *buf,
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size_t len,
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Error **errp)
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{
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return block->driver->encrypt(block, startsector, buf, len, errp);
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}
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QCryptoCipher *qcrypto_block_get_cipher(QCryptoBlock *block)
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{
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return block->cipher;
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}
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QCryptoIVGen *qcrypto_block_get_ivgen(QCryptoBlock *block)
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{
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return block->ivgen;
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}
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QCryptoHashAlgorithm qcrypto_block_get_kdf_hash(QCryptoBlock *block)
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{
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return block->kdfhash;
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}
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uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block)
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{
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return block->payload_offset;
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}
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void qcrypto_block_free(QCryptoBlock *block)
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{
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if (!block) {
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return;
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}
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block->driver->cleanup(block);
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qcrypto_cipher_free(block->cipher);
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qcrypto_ivgen_free(block->ivgen);
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g_free(block);
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}
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int qcrypto_block_decrypt_helper(QCryptoCipher *cipher,
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size_t niv,
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QCryptoIVGen *ivgen,
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int sectorsize,
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uint64_t startsector,
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uint8_t *buf,
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size_t len,
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Error **errp)
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{
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uint8_t *iv;
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int ret = -1;
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iv = niv ? g_new0(uint8_t, niv) : NULL;
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while (len > 0) {
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size_t nbytes;
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if (niv) {
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if (qcrypto_ivgen_calculate(ivgen,
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startsector,
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iv, niv,
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errp) < 0) {
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goto cleanup;
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}
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if (qcrypto_cipher_setiv(cipher,
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iv, niv,
|
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errp) < 0) {
|
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goto cleanup;
|
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}
|
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}
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|
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nbytes = len > sectorsize ? sectorsize : len;
|
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if (qcrypto_cipher_decrypt(cipher, buf, buf,
|
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nbytes, errp) < 0) {
|
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goto cleanup;
|
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}
|
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startsector++;
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buf += nbytes;
|
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len -= nbytes;
|
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}
|
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|
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ret = 0;
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cleanup:
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g_free(iv);
|
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return ret;
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}
|
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|
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|
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int qcrypto_block_encrypt_helper(QCryptoCipher *cipher,
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size_t niv,
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QCryptoIVGen *ivgen,
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int sectorsize,
|
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uint64_t startsector,
|
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uint8_t *buf,
|
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size_t len,
|
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Error **errp)
|
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{
|
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uint8_t *iv;
|
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int ret = -1;
|
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|
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iv = niv ? g_new0(uint8_t, niv) : NULL;
|
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|
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while (len > 0) {
|
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size_t nbytes;
|
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if (niv) {
|
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if (qcrypto_ivgen_calculate(ivgen,
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startsector,
|
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iv, niv,
|
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errp) < 0) {
|
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goto cleanup;
|
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}
|
||||
|
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if (qcrypto_cipher_setiv(cipher,
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iv, niv,
|
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errp) < 0) {
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goto cleanup;
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}
|
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}
|
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|
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nbytes = len > sectorsize ? sectorsize : len;
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if (qcrypto_cipher_encrypt(cipher, buf, buf,
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nbytes, errp) < 0) {
|
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goto cleanup;
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}
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startsector++;
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buf += nbytes;
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len -= nbytes;
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}
|
||||
|
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ret = 0;
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cleanup:
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g_free(iv);
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return ret;
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}
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92
crypto/blockpriv.h
Normal file
92
crypto/blockpriv.h
Normal file
|
|
@ -0,0 +1,92 @@
|
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/*
|
||||
* QEMU Crypto block device encryption
|
||||
*
|
||||
* 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/>.
|
||||
*
|
||||
*/
|
||||
|
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#ifndef QCRYPTO_BLOCK_PRIV_H__
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#define QCRYPTO_BLOCK_PRIV_H__
|
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|
||||
#include "crypto/block.h"
|
||||
|
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typedef struct QCryptoBlockDriver QCryptoBlockDriver;
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|
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struct QCryptoBlock {
|
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QCryptoBlockFormat format;
|
||||
|
||||
const QCryptoBlockDriver *driver;
|
||||
void *opaque;
|
||||
|
||||
QCryptoCipher *cipher;
|
||||
QCryptoIVGen *ivgen;
|
||||
QCryptoHashAlgorithm kdfhash;
|
||||
size_t niv;
|
||||
uint64_t payload_offset; /* In bytes */
|
||||
};
|
||||
|
||||
struct QCryptoBlockDriver {
|
||||
int (*open)(QCryptoBlock *block,
|
||||
QCryptoBlockOpenOptions *options,
|
||||
QCryptoBlockReadFunc readfunc,
|
||||
void *opaque,
|
||||
unsigned int flags,
|
||||
Error **errp);
|
||||
|
||||
int (*create)(QCryptoBlock *block,
|
||||
QCryptoBlockCreateOptions *options,
|
||||
QCryptoBlockInitFunc initfunc,
|
||||
QCryptoBlockWriteFunc writefunc,
|
||||
void *opaque,
|
||||
Error **errp);
|
||||
|
||||
void (*cleanup)(QCryptoBlock *block);
|
||||
|
||||
int (*encrypt)(QCryptoBlock *block,
|
||||
uint64_t startsector,
|
||||
uint8_t *buf,
|
||||
size_t len,
|
||||
Error **errp);
|
||||
int (*decrypt)(QCryptoBlock *block,
|
||||
uint64_t startsector,
|
||||
uint8_t *buf,
|
||||
size_t len,
|
||||
Error **errp);
|
||||
|
||||
bool (*has_format)(const uint8_t *buf,
|
||||
size_t buflen);
|
||||
};
|
||||
|
||||
|
||||
int qcrypto_block_decrypt_helper(QCryptoCipher *cipher,
|
||||
size_t niv,
|
||||
QCryptoIVGen *ivgen,
|
||||
int sectorsize,
|
||||
uint64_t startsector,
|
||||
uint8_t *buf,
|
||||
size_t len,
|
||||
Error **errp);
|
||||
|
||||
int qcrypto_block_encrypt_helper(QCryptoCipher *cipher,
|
||||
size_t niv,
|
||||
QCryptoIVGen *ivgen,
|
||||
int sectorsize,
|
||||
uint64_t startsector,
|
||||
uint8_t *buf,
|
||||
size_t len,
|
||||
Error **errp);
|
||||
|
||||
#endif /* QCRYPTO_BLOCK_PRIV_H__ */
|
||||
Loading…
Add table
Add a link
Reference in a new issue