146 lines
4.3 KiB
C
146 lines
4.3 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++) {
|
|
g_autofree 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);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
int qcrypto_afsplit_encode(QCryptoHashAlgorithm hash,
|
|
size_t blocklen,
|
|
uint32_t stripes,
|
|
const uint8_t *in,
|
|
uint8_t *out,
|
|
Error **errp)
|
|
{
|
|
g_autofree uint8_t *block = g_new0(uint8_t, blocklen);
|
|
size_t i;
|
|
|
|
for (i = 0; i < (stripes - 1); i++) {
|
|
if (qcrypto_random_bytes(out + (i * blocklen), blocklen, errp) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
qcrypto_afsplit_xor(blocklen,
|
|
out + (i * blocklen),
|
|
block,
|
|
block);
|
|
if (qcrypto_afsplit_hash(hash, blocklen, block,
|
|
errp) < 0) {
|
|
return -1;
|
|
}
|
|
}
|
|
qcrypto_afsplit_xor(blocklen,
|
|
in,
|
|
block,
|
|
out + (i * blocklen));
|
|
return 0;
|
|
}
|
|
|
|
|
|
int qcrypto_afsplit_decode(QCryptoHashAlgorithm hash,
|
|
size_t blocklen,
|
|
uint32_t stripes,
|
|
const uint8_t *in,
|
|
uint8_t *out,
|
|
Error **errp)
|
|
{
|
|
g_autofree uint8_t *block = g_new0(uint8_t, blocklen);
|
|
size_t i;
|
|
|
|
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) {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
qcrypto_afsplit_xor(blocklen,
|
|
in + (i * blocklen),
|
|
block,
|
|
out);
|
|
return 0;
|
|
}
|