mbed-os/targets/TARGET_NORDIC/TARGET_NRF5/trng_api.c

91 lines
3.0 KiB
C

/*
* Copyright (c) 2017 Nordic Semiconductor ASA
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list
* of conditions and the following disclaimer.
*
* 2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA
* integrated circuit in a product or a software update for such product, must reproduce
* the above copyright notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be
* used to endorse or promote products derived from this software without specific prior
* written permission.
*
* 4. This software, with or without modification, must only be used with a
* Nordic Semiconductor ASA integrated circuit.
*
* 5. Any software provided in binary or object form under this license must not be reverse
* engineered, decompiled, modified and/or disassembled.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#if defined(DEVICE_TRNG)
#include "trng_api.h"
#include "nrf_drv_rng.h"
void trng_init(trng_t *obj)
{
(void) obj;
(void)nrf_drv_rng_init(NULL);
}
void trng_free(trng_t *obj)
{
(void) obj;
nrf_drv_rng_uninit();
}
/* Get random data from NRF5x TRNG peripheral.
*
* This implementation returns num of random bytes in range <1, length>.
* For parameters description see trng_api.h file.
*/
int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
{
uint8_t bytes_available;
(void) obj;
nrf_drv_rng_bytes_available(&bytes_available);
if (bytes_available == 0) {
nrf_drv_rng_block_rand(output, 1);
*output_length = 1;
} else {
if (bytes_available > length) {
bytes_available = length;
}
if (nrf_drv_rng_rand(output, bytes_available) != NRF_SUCCESS) {
*output_length = 0;
return -1;
} else {
*output_length = bytes_available;
}
}
return 0;
}
#endif