qemu/crypto/block.c

283 lines
7.5 KiB
C

/*
* 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/>.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "crypto/blockpriv.h"
#include "crypto/block-qcow.h"
#include "crypto/block-luks.h"
static const QCryptoBlockDriver *qcrypto_block_drivers[] = {
[Q_CRYPTO_BLOCK_FORMAT_QCOW] = &qcrypto_block_driver_qcow,
[Q_CRYPTO_BLOCK_FORMAT_LUKS] = &qcrypto_block_driver_luks,
};
bool qcrypto_block_has_format(QCryptoBlockFormat format,
const uint8_t *buf,
size_t len)
{
const QCryptoBlockDriver *driver;
if (format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
!qcrypto_block_drivers[format]) {
return false;
}
driver = qcrypto_block_drivers[format];
return driver->has_format(buf, len);
}
QCryptoBlock *qcrypto_block_open(QCryptoBlockOpenOptions *options,
const char *optprefix,
QCryptoBlockReadFunc readfunc,
void *opaque,
unsigned int flags,
Error **errp)
{
QCryptoBlock *block = g_new0(QCryptoBlock, 1);
block->format = options->format;
if (options->format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
!qcrypto_block_drivers[options->format]) {
error_setg(errp, "Unsupported block driver %s",
QCryptoBlockFormat_str(options->format));
g_free(block);
return NULL;
}
block->driver = qcrypto_block_drivers[options->format];
if (block->driver->open(block, options, optprefix,
readfunc, opaque, flags, errp) < 0) {
g_free(block);
return NULL;
}
return block;
}
QCryptoBlock *qcrypto_block_create(QCryptoBlockCreateOptions *options,
const char *optprefix,
QCryptoBlockInitFunc initfunc,
QCryptoBlockWriteFunc writefunc,
void *opaque,
Error **errp)
{
QCryptoBlock *block = g_new0(QCryptoBlock, 1);
block->format = options->format;
if (options->format >= G_N_ELEMENTS(qcrypto_block_drivers) ||
!qcrypto_block_drivers[options->format]) {
error_setg(errp, "Unsupported block driver %s",
QCryptoBlockFormat_str(options->format));
g_free(block);
return NULL;
}
block->driver = qcrypto_block_drivers[options->format];
if (block->driver->create(block, options, optprefix, initfunc,
writefunc, opaque, errp) < 0) {
g_free(block);
return NULL;
}
return block;
}
QCryptoBlockInfo *qcrypto_block_get_info(QCryptoBlock *block,
Error **errp)
{
QCryptoBlockInfo *info = g_new0(QCryptoBlockInfo, 1);
info->format = block->format;
if (block->driver->get_info &&
block->driver->get_info(block, info, errp) < 0) {
g_free(info);
return NULL;
}
return info;
}
int qcrypto_block_decrypt(QCryptoBlock *block,
uint64_t startsector,
uint8_t *buf,
size_t len,
Error **errp)
{
return block->driver->decrypt(block, startsector, buf, len, errp);
}
int qcrypto_block_encrypt(QCryptoBlock *block,
uint64_t startsector,
uint8_t *buf,
size_t len,
Error **errp)
{
return block->driver->encrypt(block, startsector, buf, len, errp);
}
QCryptoCipher *qcrypto_block_get_cipher(QCryptoBlock *block)
{
return block->cipher;
}
QCryptoIVGen *qcrypto_block_get_ivgen(QCryptoBlock *block)
{
return block->ivgen;
}
QCryptoHashAlgorithm qcrypto_block_get_kdf_hash(QCryptoBlock *block)
{
return block->kdfhash;
}
uint64_t qcrypto_block_get_payload_offset(QCryptoBlock *block)
{
return block->payload_offset;
}
void qcrypto_block_free(QCryptoBlock *block)
{
if (!block) {
return;
}
block->driver->cleanup(block);
qcrypto_cipher_free(block->cipher);
qcrypto_ivgen_free(block->ivgen);
g_free(block);
}
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)
{
uint8_t *iv;
int ret = -1;
iv = niv ? g_new0(uint8_t, niv) : NULL;
while (len > 0) {
size_t nbytes;
if (niv) {
if (qcrypto_ivgen_calculate(ivgen,
startsector,
iv, niv,
errp) < 0) {
goto cleanup;
}
if (qcrypto_cipher_setiv(cipher,
iv, niv,
errp) < 0) {
goto cleanup;
}
}
nbytes = len > sectorsize ? sectorsize : len;
if (qcrypto_cipher_decrypt(cipher, buf, buf,
nbytes, errp) < 0) {
goto cleanup;
}
startsector++;
buf += nbytes;
len -= nbytes;
}
ret = 0;
cleanup:
g_free(iv);
return ret;
}
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)
{
uint8_t *iv;
int ret = -1;
iv = niv ? g_new0(uint8_t, niv) : NULL;
while (len > 0) {
size_t nbytes;
if (niv) {
if (qcrypto_ivgen_calculate(ivgen,
startsector,
iv, niv,
errp) < 0) {
goto cleanup;
}
if (qcrypto_cipher_setiv(cipher,
iv, niv,
errp) < 0) {
goto cleanup;
}
}
nbytes = len > sectorsize ? sectorsize : len;
if (qcrypto_cipher_encrypt(cipher, buf, buf,
nbytes, errp) < 0) {
goto cleanup;
}
startsector++;
buf += nbytes;
len -= nbytes;
}
ret = 0;
cleanup:
g_free(iv);
return ret;
}