qemu/crypto/afsplit.c
Thomas Huth e361a772ff Don't talk about the LGPL if the file is licensed under the GPL
Some files claim that the code is licensed under the GPL, but then
suddenly suggest that the user should have a look at the LGPL.
That's of course non-sense, replace it with the correct GPL wording
instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1548255083-8190-1-git-send-email-thuth@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-01-30 10:51:20 +01:00

159 lines
4.4 KiB
C

/*
* QEMU Crypto anti forensic information splitter
*
* Copyright (c) 2015-2016 Red Hat, Inc.
*
* Derived from cryptsetup package lib/luks1/af.c
*
* Copyright (C) 2004, Clemens Fruhwirth <clemens@endorphin.org>
* Copyright (C) 2009-2012, Red Hat, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/bswap.h"
#include "crypto/afsplit.h"
#include "crypto/random.h"
static void qcrypto_afsplit_xor(size_t blocklen,
const uint8_t *in1,
const uint8_t *in2,
uint8_t *out)
{
size_t i;
for (i = 0; i < blocklen; i++) {
out[i] = in1[i] ^ in2[i];
}
}
static int qcrypto_afsplit_hash(QCryptoHashAlgorithm hash,
size_t blocklen,
uint8_t *block,
Error **errp)
{
size_t digestlen = qcrypto_hash_digest_len(hash);
size_t hashcount = blocklen / digestlen;
size_t finallen = blocklen % digestlen;
uint32_t i;
if (finallen) {
hashcount++;
} else {
finallen = digestlen;
}
for (i = 0; i < hashcount; i++) {
uint8_t *out = NULL;
size_t outlen = 0;
uint32_t iv = cpu_to_be32(i);
struct iovec in[] = {
{ .iov_base = &iv,
.iov_len = sizeof(iv) },
{ .iov_base = block + (i * digestlen),
.iov_len = (i == (hashcount - 1)) ? finallen : digestlen },
};
if (qcrypto_hash_bytesv(hash,
in,
G_N_ELEMENTS(in),
&out, &outlen,
errp) < 0) {
return -1;
}
assert(outlen == digestlen);
memcpy(block + (i * digestlen), out,
(i == (hashcount - 1)) ? finallen : digestlen);
g_free(out);
}
return 0;
}
int qcrypto_afsplit_encode(QCryptoHashAlgorithm hash,
size_t blocklen,
uint32_t stripes,
const uint8_t *in,
uint8_t *out,
Error **errp)
{
uint8_t *block = g_new0(uint8_t, blocklen);
size_t i;
int ret = -1;
for (i = 0; i < (stripes - 1); i++) {
if (qcrypto_random_bytes(out + (i * blocklen), blocklen, errp) < 0) {
goto cleanup;
}
qcrypto_afsplit_xor(blocklen,
out + (i * blocklen),
block,
block);
if (qcrypto_afsplit_hash(hash, blocklen, block,
errp) < 0) {
goto cleanup;
}
}
qcrypto_afsplit_xor(blocklen,
in,
block,
out + (i * blocklen));
ret = 0;
cleanup:
g_free(block);
return ret;
}
int qcrypto_afsplit_decode(QCryptoHashAlgorithm hash,
size_t blocklen,
uint32_t stripes,
const uint8_t *in,
uint8_t *out,
Error **errp)
{
uint8_t *block = g_new0(uint8_t, blocklen);
size_t i;
int ret = -1;
for (i = 0; i < (stripes - 1); i++) {
qcrypto_afsplit_xor(blocklen,
in + (i * blocklen),
block,
block);
if (qcrypto_afsplit_hash(hash, blocklen, block,
errp) < 0) {
goto cleanup;
}
}
qcrypto_afsplit_xor(blocklen,
in + (i * blocklen),
block,
out);
ret = 0;
cleanup:
g_free(block);
return ret;
}