| /* |
| * Copyright (c) 2016, The OpenThread Authors. |
| * 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 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 the copyright holder nor the |
| * names of its contributors may be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * 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. |
| */ |
| |
| /** |
| * @file |
| * This file implements true random number generator. |
| */ |
| |
| #include <string.h> |
| |
| #include <openthread/platform/random.h> |
| |
| #include "platform-da15000.h" |
| |
| #include "hw_trng.h" |
| #include "sdk_defs.h" |
| |
| #define RANDOM_SIZE_OF_BUFFER 32 |
| |
| static uint32_t sRandomNumbers[RANDOM_SIZE_OF_BUFFER]; |
| static uint8_t sRandomNextNumberIndex = 0; |
| static bool sRandomGeneratorStarted = false; |
| |
| static void RandomCallback(void) |
| { |
| hw_trng_get_numbers(sRandomNumbers, RANDOM_SIZE_OF_BUFFER); |
| sRandomNextNumberIndex = 0; |
| hw_trng_stop(); |
| hw_trng_disable_clk(); |
| hw_trng_disable_interrupt(); |
| sRandomGeneratorStarted = false; |
| } |
| |
| static void StartGenerator(void) |
| { |
| hw_trng_enable(RandomCallback); |
| sRandomGeneratorStarted = true; |
| } |
| |
| void da15000RandomInit(void) |
| { |
| StartGenerator(); |
| } |
| |
| uint32_t otPlatRandomGet(void) |
| { |
| uint32_t randomNumber; |
| bool randomGet = false; |
| |
| do |
| { |
| GLOBAL_INT_DISABLE(); |
| |
| if (sRandomNextNumberIndex < RANDOM_SIZE_OF_BUFFER) |
| { |
| randomNumber = sRandomNumbers[sRandomNextNumberIndex++]; |
| randomGet = true; |
| |
| if (sRandomNextNumberIndex == RANDOM_SIZE_OF_BUFFER) |
| { |
| StartGenerator(); |
| } |
| } |
| else if (hw_trng_get_fifo_level() > 0) |
| { |
| randomNumber = hw_trng_get_number(); |
| randomGet = true; |
| } |
| else if (!sRandomGeneratorStarted) |
| { |
| StartGenerator(); |
| } |
| |
| GLOBAL_INT_RESTORE(); |
| } while (!randomGet); |
| |
| return randomNumber; |
| } |
| |
| otError otPlatRandomGetTrue(uint8_t *aOutput, uint16_t aOutputLength) |
| { |
| uint32_t randomNumber; |
| |
| while (aOutputLength) |
| { |
| randomNumber = otPlatRandomGet(); |
| |
| if (aOutputLength < 4) |
| { |
| memcpy(aOutput, &randomNumber, aOutputLength); |
| aOutputLength = 0; |
| } |
| else |
| { |
| memcpy(aOutput, &randomNumber, 4); |
| aOutputLength -= 4; |
| aOutput += 4; |
| } |
| } |
| |
| return OT_ERROR_NONE; |
| } |