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| 1 | +/* |
| 2 | + * Copyright (c) 2017 Nordic Semiconductor ASA |
| 3 | + * All rights reserved. |
| 4 | + * |
| 5 | + * Redistribution and use in source and binary forms, with or without modification, |
| 6 | + * are permitted provided that the following conditions are met: |
| 7 | + * |
| 8 | + * 1. Redistributions of source code must retain the above copyright notice, this list |
| 9 | + * of conditions and the following disclaimer. |
| 10 | + * |
| 11 | + * 2. Redistributions in binary form, except as embedded into a Nordic Semiconductor ASA |
| 12 | + * integrated circuit in a product or a software update for such product, must reproduce |
| 13 | + * the above copyright notice, this list of conditions and the following disclaimer in |
| 14 | + * the documentation and/or other materials provided with the distribution. |
| 15 | + * |
| 16 | + * 3. Neither the name of Nordic Semiconductor ASA nor the names of its contributors may be |
| 17 | + * used to endorse or promote products derived from this software without specific prior |
| 18 | + * written permission. |
| 19 | + * |
| 20 | + * 4. This software, with or without modification, must only be used with a |
| 21 | + * Nordic Semiconductor ASA integrated circuit. |
| 22 | + * |
| 23 | + * 5. Any software provided in binary or object form under this license must not be reverse |
| 24 | + * engineered, decompiled, modified and/or disassembled. |
| 25 | + * |
| 26 | + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND |
| 27 | + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| 28 | + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| 29 | + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR |
| 30 | + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 31 | + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 32 | + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
| 33 | + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 34 | + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 35 | + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 36 | + * |
| 37 | + */ |
| 38 | + |
| 39 | +#if defined(DEVICE_TRNG) |
| 40 | +#include "trng_api.h" |
| 41 | +#include "nrf_drv_rng.h" |
| 42 | + |
| 43 | +void trng_init(trng_t *obj) |
| 44 | +{ |
| 45 | + (void) obj; |
| 46 | + |
| 47 | + (void)nrf_drv_rng_init(NULL); |
| 48 | +} |
| 49 | + |
| 50 | +void trng_free(trng_t *obj) |
| 51 | +{ |
| 52 | + (void) obj; |
| 53 | + |
| 54 | + nrf_drv_rng_uninit(); |
| 55 | +} |
| 56 | + |
| 57 | +/* Get random data from NRF5x TRNG peripheral. |
| 58 | + * |
| 59 | + * This implementation returns num of random bytes in range <1, length>. |
| 60 | + * For parameters description see trng_api.h file. |
| 61 | + */ |
| 62 | +int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length) |
| 63 | +{ |
| 64 | + uint8_t bytes_available; |
| 65 | + |
| 66 | + (void) obj; |
| 67 | + |
| 68 | + nrf_drv_rng_bytes_available(&bytes_available); |
| 69 | + |
| 70 | + if (bytes_available == 0) { |
| 71 | + nrf_drv_rng_block_rand(output, 1); |
| 72 | + *output_length = 1; |
| 73 | + } else { |
| 74 | + |
| 75 | + if (bytes_available > length) { |
| 76 | + bytes_available = length; |
| 77 | + } |
| 78 | + |
| 79 | + if (nrf_drv_rng_rand(output, bytes_available) != NRF_SUCCESS) { |
| 80 | + *output_length = 0; |
| 81 | + return -1; |
| 82 | + } else { |
| 83 | + *output_length = bytes_available; |
| 84 | + } |
| 85 | + } |
| 86 | + |
| 87 | + return 0; |
| 88 | +} |
| 89 | + |
| 90 | +#endif |
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