mbed-os/targets/TARGET_ARM_FM/TARGET_FVP_MPS2/trng_api.c

57 lines
1.4 KiB
C

/*
* Copyright (c) 2017-2019 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing software
* distributed under the License is distributed on an "AS IS" BASIS
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "trng_api.h"
#include "device.h"
#include <stdlib.h>
/** NOTE: FastModel are software models not contain any TRNG peripheral
* So C library srand() and rand() are used to simulate TRNG device
*/
void trng_init(trng_t *obj)
{
srand(0);
(void)obj;
}
void trng_free(trng_t *obj)
{
(void)obj;
}
/** Get random data from TRNG peripheral
*
* @param obj The TRNG object
* @param output The pointer to an output array
* @param length The size of output data, to avoid buffer overwrite
* @param output_length The length of generated data
* @return 0 success, -1 fail
*/
int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
{
(void)obj;
for (int i = 0; i < length; ++i) {
output[i] = rand() % 256;
}
*output_length = length;
return 0;
}