| /* |
| * Copyright (c) 2019, 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 includes definitions for OpenThread random number generation manager class. |
| */ |
| |
| #ifndef RANDOM_MANAGER_HPP_ |
| #define RANDOM_MANAGER_HPP_ |
| |
| #include "openthread-core-config.h" |
| |
| #include <stdint.h> |
| #include <openthread/error.h> |
| |
| #if !OPENTHREAD_RADIO |
| #include <mbedtls/ctr_drbg.h> |
| #include <mbedtls/entropy.h> |
| #endif |
| |
| #include "common/non_copyable.hpp" |
| |
| #if (!defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES) && \ |
| (!defined(MBEDTLS_NO_PLATFORM_ENTROPY) || defined(MBEDTLS_HAVEGE_C) || defined(MBEDTLS_ENTROPY_HARDWARE_ALT))) |
| #define OT_MBEDTLS_STRONG_DEFAULT_ENTROPY_PRESENT |
| #endif |
| |
| namespace ot { |
| |
| /** |
| * This class manages random number generator initialization/deinitialization. |
| * |
| */ |
| class RandomManager : private NonCopyable |
| { |
| public: |
| /** |
| * This constructor initializes the object. |
| * |
| */ |
| RandomManager(void); |
| |
| /** |
| * This destructor deinitializes the object. |
| * |
| */ |
| ~RandomManager(void); |
| |
| /** |
| * This static method generates and returns a random value using a non-crypto Pseudo Random Number Generator. |
| * |
| * @returns A random `uint32_t` value. |
| * |
| */ |
| static uint32_t NonCryptoGetUint32(void); |
| |
| #if !OPENTHREAD_RADIO |
| /** |
| * This static method returns the initialized mbedtls_entropy_context. |
| * |
| * @returns A pointer to initialized mbedtls_entropy_context. |
| */ |
| static mbedtls_entropy_context *GetMbedTlsEntropyContext(void) { return sEntropy.GetContext(); } |
| |
| /** |
| * This static method fills a given buffer with cryptographically secure random bytes. |
| * |
| * @param[out] aBuffer A pointer to a buffer to fill with the random bytes. |
| * @param[in] aSize Size of buffer (number of bytes to fill). |
| * |
| * @retval OT_ERROR_NONE Successfully filled buffer with random values. |
| * |
| */ |
| static otError CryptoFillBuffer(uint8_t *aBuffer, uint16_t aSize) { return sCtrDrbg.FillBuffer(aBuffer, aSize); } |
| |
| /** |
| * This static method returns the initialized mbedtls_ctr_drbg_context. |
| * |
| * @returns A pointer to the initialized mbedtls_ctr_drbg_context. |
| * |
| */ |
| static mbedtls_ctr_drbg_context *GetMbedTlsCtrDrbgContext(void) { return sCtrDrbg.GetContext(); } |
| #endif |
| |
| private: |
| class NonCryptoPrng // A non-crypto Pseudo Random Number Generator (PRNG) |
| { |
| public: |
| void Init(uint32_t aSeed); |
| uint32_t GetNext(void); |
| |
| private: |
| uint32_t mState; |
| }; |
| |
| #if !OPENTHREAD_RADIO |
| class Entropy |
| { |
| public: |
| void Init(void); |
| void Deinit(void); |
| |
| mbedtls_entropy_context *GetContext(void) { return &mEntropyContext; } |
| |
| private: |
| #ifndef OT_MBEDTLS_STRONG_DEFAULT_ENTROPY_PRESENT |
| static int HandleMbedtlsEntropyPoll(void *aData, unsigned char *aOutput, size_t aInLen, size_t *aOutLen); |
| #endif // OT_MBEDTLS_STRONG_DEFAULT_ENTROPY_PRESENT |
| |
| mbedtls_entropy_context mEntropyContext; |
| }; |
| |
| class CryptoCtrDrbg |
| { |
| public: |
| void Init(void); |
| void Deinit(void); |
| otError FillBuffer(uint8_t *aBuffer, uint16_t aSize); |
| |
| mbedtls_ctr_drbg_context *GetContext(void) { return &mCtrDrbg; } |
| |
| private: |
| mbedtls_ctr_drbg_context mCtrDrbg; |
| }; |
| #endif |
| |
| static uint16_t sInitCount; |
| static NonCryptoPrng sPrng; |
| #if !OPENTHREAD_RADIO |
| static Entropy sEntropy; |
| static CryptoCtrDrbg sCtrDrbg; |
| #endif |
| }; |
| |
| } // namespace ot |
| |
| #endif // RANDOM_MANAGER_HPP_ |