qemu/crypto/block.c
Daniel P. Berrange 90d6f60d07 crypto: report enum strings instead of values in errors
Several error messages print out the raw enum value, which
is less than helpful to users, as these values are not
documented, nor stable across QEMU releases. Switch to use
the enum string instead.

The nettle impl also had two typos where it mistakenly
said "algorithm" instead of "mode", and actually reported
the algorithm value too.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2016-09-12 12:00:52 +01:00

281 lines
7.4 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,
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_lookup[options->format]);
g_free(block);
return NULL;
}
block->driver = qcrypto_block_drivers[options->format];
if (block->driver->open(block, options,
readfunc, opaque, flags, errp) < 0) {
g_free(block);
return NULL;
}
return block;
}
QCryptoBlock *qcrypto_block_create(QCryptoBlockCreateOptions *options,
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_lookup[options->format]);
g_free(block);
return NULL;
}
block->driver = qcrypto_block_drivers[options->format];
if (block->driver->create(block, options, 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;
}