| /* |
| * 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 a pseudo-random number generator. |
| * |
| * @warning |
| * This implementation is not a true random number generator and does @em satisfy the Thread requirements. |
| */ |
| |
| #include <string.h> |
| |
| #include <openthread/platform/random.h> |
| |
| #include "platform-da15000.h" |
| #include "hw_trng.h" |
| #include "sdk_defs.h" |
| |
| #define HW_TRNG_RAM (0x40040000) |
| |
| static uint32_t sState = 1; |
| static uint32_t sSeed; |
| |
| int zhal_get_entropy(uint8_t *outEntropy, size_t inSize) |
| { |
| uint32_t randword; |
| unsigned char *pbuf = outEntropy; |
| const size_t req_words = inSize >> 2; |
| const unsigned char *pbuf_end = outEntropy + inSize; |
| const unsigned char *preq_words_end = (unsigned char *)(((uint32_t *)outEntropy) + req_words); |
| ptrdiff_t remainder_bytes = pbuf_end - preq_words_end; |
| |
| hw_trng_enable(NULL); |
| |
| for (pbuf = outEntropy; pbuf < preq_words_end; pbuf += 4) |
| { |
| /* Wait for a random word to become available in the TRNG FIFO. */ |
| while ((TRNG->TRNG_FIFOLVL_REG & TRNG_TRNG_FIFOLVL_REG_TRNG_FIFOLVL_Msk) == 0); |
| |
| randword = *((volatile uint32_t *)HW_TRNG_RAM); |
| memcpy(pbuf, &randword, 4); |
| } |
| |
| if (remainder_bytes) |
| { |
| while ((TRNG->TRNG_FIFOLVL_REG & TRNG_TRNG_FIFOLVL_REG_TRNG_FIFOLVL_Msk) == 0); |
| |
| randword = *((volatile uint32_t *)HW_TRNG_RAM); |
| memcpy(pbuf, &randword, remainder_bytes); |
| } |
| |
| hw_trng_disable(); |
| |
| return 0; |
| } |
| |
| void da15000RandomInit(void) |
| { |
| zhal_get_entropy((uint8_t *)&sSeed, sizeof(sSeed)); |
| sState = sSeed; |
| } |
| |
| uint32_t otPlatRandomGet(void) |
| { |
| uint32_t mlcg; |
| zhal_get_entropy((uint8_t *)&mlcg, sizeof(mlcg)); |
| return mlcg; |
| } |
| |
| otError otPlatRandomGetTrue(uint8_t *aOutput, uint16_t aOutputLength) |
| { |
| |
| for (uint16_t length = 0; length < aOutputLength; length++) |
| { |
| aOutput[length] = (uint8_t)otPlatRandomGet(); |
| } |
| |
| return OT_ERROR_NONE; |
| } |