Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

targets/TARGET_NUVOTON/TARGET_NUC472/crypto/crypto-misc.c@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library
elessair 0:f269e3021894 2 * Copyright (c) 2015-2016 Nuvoton
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Licensed under the Apache License, Version 2.0 (the "License");
elessair 0:f269e3021894 5 * you may not use this file except in compliance with the License.
elessair 0:f269e3021894 6 * You may obtain a copy of the License at
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 9 *
elessair 0:f269e3021894 10 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 11 * distributed under the License is distributed on an "AS IS" BASIS,
elessair 0:f269e3021894 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 13 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 14 * limitations under the License.
elessair 0:f269e3021894 15 */
elessair 0:f269e3021894 16
elessair 0:f269e3021894 17
elessair 0:f269e3021894 18 #include "cmsis.h"
elessair 0:f269e3021894 19 #include "mbed_assert.h"
elessair 0:f269e3021894 20 #include "nu_modutil.h"
elessair 0:f269e3021894 21 #include "nu_bitutil.h"
elessair 0:f269e3021894 22 #include "crypto-misc.h"
elessair 0:f269e3021894 23
elessair 0:f269e3021894 24 static int crypto_inited = 0;
elessair 0:f269e3021894 25 static int crypto_sha_avail = 1;
elessair 0:f269e3021894 26
elessair 0:f269e3021894 27 void crypto_init(void)
elessair 0:f269e3021894 28 {
elessair 0:f269e3021894 29 if (crypto_inited) {
elessair 0:f269e3021894 30 return;
elessair 0:f269e3021894 31 }
elessair 0:f269e3021894 32 crypto_inited = 1;
elessair 0:f269e3021894 33
elessair 0:f269e3021894 34 CLK_EnableModuleClock(CRPT_MODULE);
elessair 0:f269e3021894 35 }
elessair 0:f269e3021894 36
elessair 0:f269e3021894 37 /* Implementation that should never be optimized out by the compiler */
elessair 0:f269e3021894 38 void crypto_zeroize(void *v, size_t n)
elessair 0:f269e3021894 39 {
elessair 0:f269e3021894 40 volatile unsigned char *p = (unsigned char*) v;
elessair 0:f269e3021894 41 while (n--) {
elessair 0:f269e3021894 42 *p++ = 0;
elessair 0:f269e3021894 43 }
elessair 0:f269e3021894 44 }
elessair 0:f269e3021894 45
elessair 0:f269e3021894 46 int crypto_sha_acquire(void)
elessair 0:f269e3021894 47 {
elessair 0:f269e3021894 48 if (crypto_sha_avail) {
elessair 0:f269e3021894 49 crypto_sha_avail = 0;
elessair 0:f269e3021894 50 return 1;
elessair 0:f269e3021894 51 }
elessair 0:f269e3021894 52 else {
elessair 0:f269e3021894 53 return 0;
elessair 0:f269e3021894 54 }
elessair 0:f269e3021894 55
elessair 0:f269e3021894 56 }
elessair 0:f269e3021894 57
elessair 0:f269e3021894 58 void crypto_sha_release(void)
elessair 0:f269e3021894 59 {
elessair 0:f269e3021894 60 if (! crypto_sha_avail) {
elessair 0:f269e3021894 61 crypto_sha_avail = 1;
elessair 0:f269e3021894 62 }
elessair 0:f269e3021894 63 }