31 lines
776 B
C
31 lines
776 B
C
|
/* Copyright 2015 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 "dcrypto.h"
|
||
|
|
|
||
|
|
#include "cryptoc/p256.h"
|
||
|
|
#include "cryptoc/util.h"
|
||
|
|
|
||
|
|
static const p256_int p256_one = P256_ONE;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Key selection based on FIPS-186-4, section B.4.2 (Key Pair
|
||
|
|
* Generation by Testing Candidates).
|
||
|
|
*/
|
||
|
|
int DCRYPTO_p256_key_from_bytes(p256_int *x, p256_int *y, p256_int *d,
|
||
|
|
const uint8_t key_bytes[P256_NBYTES])
|
||
|
|
{
|
||
|
|
p256_int key;
|
||
|
|
|
||
|
|
p256_from_bin(key_bytes, &key);
|
||
|
|
if (p256_cmp(&SECP256r1_nMin2, &key) < 0)
|
||
|
|
return 0;
|
||
|
|
p256_add(&key, &p256_one, d);
|
||
|
|
always_memset(&key, 0, sizeof(key));
|
||
|
|
if (x == NULL || y == NULL)
|
||
|
|
return 1;
|
||
|
|
return dcrypto_p256_base_point_mul(d, x, y);
|
||
|
|
}
|