61 lines
1.4 KiB
C
61 lines
1.4 KiB
C
|
/* Copyright 2016 The Chromium OS Authors. All rights reserved.
|
||
|
|
* Use of this source code is governed by a BSD-style license that can be
|
||
|
|
* found in the LICENSE file.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "2hmac.h"
|
||
|
|
#include "2sha.h"
|
||
|
|
#include "2sysincludes.h"
|
||
|
|
|
||
|
|
int hmac(enum vb2_hash_algorithm alg,
|
||
|
|
const void *key, uint32_t key_size,
|
||
|
|
const void *msg, uint32_t msg_size,
|
||
|
|
uint8_t *mac, uint32_t mac_size)
|
||
|
|
{
|
||
|
|
uint32_t block_size;
|
||
|
|
uint32_t digest_size;
|
||
|
|
uint8_t k[VB2_MAX_BLOCK_SIZE];
|
||
|
|
uint8_t o_pad[VB2_MAX_BLOCK_SIZE];
|
||
|
|
uint8_t i_pad[VB2_MAX_BLOCK_SIZE];
|
||
|
|
uint8_t b[VB2_MAX_DIGEST_SIZE];
|
||
|
|
struct vb2_digest_context dc;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
if (!key | !msg | !mac)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
digest_size = vb2_digest_size(alg);
|
||
|
|
block_size = vb2_hash_block_size(alg);
|
||
|
|
if (!digest_size || !block_size)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
if (mac_size < digest_size)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
if (key_size > block_size) {
|
||
|
|
vb2_digest_buffer((uint8_t *)key, key_size, alg, k, block_size);
|
||
|
|
key_size = digest_size;
|
||
|
|
} else {
|
||
|
|
memcpy(k, key, key_size);
|
||
|
|
}
|
||
|
|
if (key_size < block_size)
|
||
|
|
memset(k + key_size, 0, block_size - key_size);
|
||
|
|
|
||
|
|
for (i = 0; i < block_size; i++) {
|
||
|
|
o_pad[i] = 0x5c ^ k[i];
|
||
|
|
i_pad[i] = 0x36 ^ k[i];
|
||
|
|
}
|
||
|
|
|
||
|
|
vb2_digest_init(&dc, alg);
|
||
|
|
vb2_digest_extend(&dc, i_pad, block_size);
|
||
|
|
vb2_digest_extend(&dc, msg, msg_size);
|
||
|
|
vb2_digest_finalize(&dc, b, digest_size);
|
||
|
|
|
||
|
|
vb2_digest_init(&dc, alg);
|
||
|
|
vb2_digest_extend(&dc, o_pad, block_size);
|
||
|
|
vb2_digest_extend(&dc, b, digest_size);
|
||
|
|
vb2_digest_finalize(&dc, mac, mac_size);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|