File content as of revision 177:619788de047e:

/*
 * 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