| /* |
| * 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 random number generator. |
| * |
| */ |
| |
| #include <openthread-core-config.h> |
| #include <openthread/config.h> |
| |
| #include <stdint.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include <utils/code_utils.h> |
| #include <openthread/platform/random.h> |
| |
| #include "platform-nrf5.h" |
| |
| #if SOFTDEVICE_PRESENT |
| #include "softdevice.h" |
| #else |
| #include <hal/nrf_rng.h> |
| |
| static uint8_t sBuffer[RNG_BUFFER_SIZE]; |
| static volatile uint32_t sReadPosition; |
| static volatile uint32_t sWritePosition; |
| |
| static inline uint32_t bufferCount(void) |
| { |
| uint32_t writePos = sWritePosition; |
| return writePos - sReadPosition; |
| } |
| |
| static inline bool bufferIsEmpty(void) |
| { |
| return (bufferCount() == 0); |
| } |
| |
| static inline bool bufferIsUint32Ready(void) |
| { |
| return (bufferCount() >= 4); |
| } |
| |
| static inline bool bufferIsFull(void) |
| { |
| return (bufferCount() >= RNG_BUFFER_SIZE); |
| } |
| |
| static inline void bufferPut(uint8_t val) |
| { |
| if (!bufferIsFull()) |
| { |
| sBuffer[(sWritePosition++) % RNG_BUFFER_SIZE] = val; |
| } |
| } |
| |
| static inline uint8_t bufferGet() |
| { |
| uint8_t retVal = 0; |
| |
| if (!bufferIsEmpty()) |
| { |
| retVal = sBuffer[sReadPosition++ % RNG_BUFFER_SIZE]; |
| } |
| |
| return retVal; |
| } |
| |
| static inline uint32_t bufferGetUint32() |
| { |
| uint32_t retVal = 0; |
| |
| if (bufferIsUint32Ready()) |
| { |
| for (uint32_t i = 0; i < 4; i++) |
| { |
| retVal <<= 8; |
| retVal |= bufferGet(); |
| } |
| } |
| |
| return retVal; |
| } |
| |
| static void generatorStart(void) |
| { |
| nrf_rng_event_clear(NRF_RNG_EVENT_VALRDY); |
| nrf_rng_int_enable(NRF_RNG_INT_VALRDY_MASK); |
| nrf_rng_task_trigger(NRF_RNG_TASK_START); |
| } |
| |
| static void generatorStop(void) |
| { |
| nrf_rng_int_disable(NRF_RNG_INT_VALRDY_MASK); |
| nrf_rng_task_trigger(NRF_RNG_TASK_STOP); |
| } |
| |
| void RNG_IRQHandler(void) |
| { |
| if (nrf_rng_event_get(NRF_RNG_EVENT_VALRDY) && nrf_rng_int_get(NRF_RNG_INT_VALRDY_MASK)) |
| { |
| nrf_rng_event_clear(NRF_RNG_EVENT_VALRDY); |
| |
| bufferPut(nrf_rng_random_value_get()); |
| |
| if (bufferIsFull()) |
| { |
| generatorStop(); |
| } |
| } |
| } |
| #endif // SOFTDEVICE_PRESENT |
| |
| void nrf5RandomInit(void) |
| { |
| uint32_t seed = 0; |
| |
| #if SOFTDEVICE_PRESENT |
| uint32_t retval; |
| |
| do |
| { |
| // Wait for the first randomized 4 bytes, to randomize software generator seed. |
| retval = sd_rand_application_vector_get((uint8_t *)&seed, sizeof(seed)); |
| } while (retval != NRF_SUCCESS && seed == 0); |
| |
| #else // SOFTDEVICE_PRESENT |
| memset(sBuffer, 0, sizeof(sBuffer)); |
| sReadPosition = 0; |
| sWritePosition = 0; |
| |
| NVIC_SetPriority(RNG_IRQn, RNG_IRQ_PRIORITY); |
| NVIC_ClearPendingIRQ(RNG_IRQn); |
| NVIC_EnableIRQ(RNG_IRQn); |
| |
| nrf_rng_error_correction_enable(); |
| nrf_rng_shorts_disable(NRF_RNG_SHORT_VALRDY_STOP_MASK); |
| generatorStart(); |
| |
| // Wait for the first randomized 4 bytes, to randomize software generator seed. |
| while (!bufferIsUint32Ready()) |
| ; |
| |
| seed = bufferGetUint32(); |
| #endif // SOFTDEVICE_PRESENT |
| |
| srand(seed); |
| } |
| |
| void nrf5RandomDeinit(void) |
| { |
| #ifndef SOFTDEVICE_PRESENT |
| generatorStop(); |
| |
| NVIC_DisableIRQ(RNG_IRQn); |
| NVIC_ClearPendingIRQ(RNG_IRQn); |
| NVIC_SetPriority(RNG_IRQn, 0); |
| #endif // SOFTDEVICE_PRESENT |
| } |
| |
| uint32_t otPlatRandomGet(void) |
| { |
| return (uint32_t)rand(); |
| } |
| |
| otError otPlatRandomGetTrue(uint8_t *aOutput, uint16_t aOutputLength) |
| { |
| otError error = OT_ERROR_NONE; |
| uint8_t copyLength; |
| uint16_t index = 0; |
| |
| otEXPECT_ACTION(aOutput && aOutputLength, error = OT_ERROR_INVALID_ARGS); |
| |
| do |
| { |
| #if SOFTDEVICE_PRESENT |
| sd_rand_application_bytes_available_get(©Length); |
| #else // SOFTDEVICE_PRESENT |
| copyLength = (uint8_t)bufferCount(); |
| #endif // SOFTDEVICE_PRESENT |
| |
| if (copyLength > aOutputLength - index) |
| { |
| copyLength = aOutputLength - index; |
| } |
| |
| if (copyLength > 0) |
| { |
| #if SOFTDEVICE_PRESENT |
| uint32_t retval = sd_rand_application_vector_get(aOutput + index, copyLength); |
| otEXPECT_ACTION(retval == NRF_SUCCESS, error = OT_ERROR_FAILED); |
| #else // SOFTDEVICE_PRESENT |
| |
| for (uint32_t i = 0; i < copyLength; i++) |
| { |
| aOutput[i + index] = bufferGet(); |
| } |
| |
| generatorStart(); |
| #endif // SOFTDEVICE_PRESENT |
| |
| index += copyLength; |
| } |
| } while (index < aOutputLength); |
| |
| exit: |
| return error; |
| } |