/** * Copyright (c) 2018 - 2019, Nordic Semiconductor ASA * * 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, except as embedded into a Nordic * Semiconductor ASA integrated circuit in a product or a software update for * such product, 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 Nordic Semiconductor ASA nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * 4. This software, with or without modification, must only be used with a * Nordic Semiconductor ASA integrated circuit. * * 5. Any software provided in binary form under this license must not be reverse * engineered, decompiled, modified and/or disassembled. * * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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. * */ #ifndef NRF_CRYPTO_RNG_H__ #define NRF_CRYPTO_RNG_H__ /** @file * * @defgroup nrf_crypto_rng RNG related functions * @{ * @ingroup nrf_crypto * * @brief RNG related functions * * @details There are two available RNG backends: * - ARM CryptoCell CC310 (default for devices with CC310). * - nRF HW RNG peripheral. * * CTR-DRBG mode - nRF HW RNG used for seeding mbed TLS CTR-DRBG (default for * devices without CC310). * * Raw mode - all data is generated by the nRF HW RNG. * * The CC310 backend meets the standards NIST 800-90B3 and AIS-31 (Class “P2 High”), and * should be preferred in most cases on devices that includes the CC310 core. Devices that * do not include CC310 should normally use the nRF HW RNG with mbed TLS CTR-DRBG. The * mbed TLS CTR-DRBG code is standardized by NIST (SP 800-90A Rev. 1). */ #include "sdk_common.h" #include "nrf_crypto_error.h" #include "nrf_crypto_rng_shared.h" #include "nrf_crypto_rng_backend.h" #ifdef __cplusplus extern "C" { #endif /** * @brief Context type for RNG. * * @note The actual type depend on the backend in use. */ typedef nrf_crypto_backend_rng_context_t nrf_crypto_rng_context_t; /** * @brief Temporary work buffer type for RNG. * * @details Only needed during initializing. Can be freed when @ref nrf_crypto_rng_init has * returned. Not needed if @ref NRF_CRYPTO_RNG_STATIC_MEMORY_BUFFERS_ENABLED is enabled * in @ref sdk_config. * * @note The actual type depend on the backend in use. */ typedef nrf_crypto_backend_rng_temp_buffer_t nrf_crypto_rng_temp_buffer_t; /**@brief Initialize the random number generator. * * @details This function has no effect when @ref NRF_CRYPTO_RNG_AUTO_INIT_ENABLED is enabled. * * @warning The p_temp_buffer is 6112 bytes when using the CC310 backend. Ensure that stack size * is sufficient if allocated on stack. Applications that use nRF HW RNG as backend or are * not RAM constrained can use internal static allocation of context and temporary buffers * (@ref NRF_CRYPTO_RNG_STATIC_MEMORY_BUFFERS_ENABLED). * * @note The context object can be reused without the need for a full reinitialization of the * backend in case of for example wakeup from system OFF, provided that the context is * located in a memory block that is retained. This only apply to the CC310 backend, and when * the context is allocated manually (NRF_CRYPTO_RNG_STATIC_MEMORY_BUFFERS_ENABLED disabled). * * @param[in] p_context Pointer to context memory. The context will be managed * internally, and the pointer is not used for subsequent calls to * the nrf_crypto_rng API. The context memory is needed until * @ref nrf_crypto_rng_uninit is called, so it should normally not * be on the stack. Use NULL if * @ref NRF_CRYPTO_RNG_STATIC_MEMORY_BUFFERS_ENABLED is enabled * in @ref sdk_config (recommended for most applications). * * @param[in,out] p_temp_buffer Temporary buffer needed during initialization of the backend. It * is not used after the return of this function, and can be freed * at that point. Buffer is allocated internally if the pointer is * NULL, using the allocated defined by @ref NRF_CRYPTO_ALLOCATOR * in @c sdk_config.h. Use NULL if * @ref NRF_CRYPTO_RNG_STATIC_MEMORY_BUFFERS_ENABLED is enabled * in @ref sdk_config (recommended for most applications). * * @retval NRF_SUCCESS If random number generator was initialized * successfully. * @retval NRF_ERROR_CRYPTO_NOT_INITIALIZED @ref nrf_crypto_init was not called prior to this * function. * @retval NRF_ERROR_CRYPTO_CONTEXT_NULL p_context was NULL. * @retval NRF_ERROR_CRYPTO_INTERNAL If an internal error occurred in the nrf_crypto * backend. * @retval NRF_ERROR_CRYPTO_ALLOC_FAILED Unable to allocate memory for the context or work * buffer. * @retval NRF_ERROR_CRYPTO_STACK_OVERFLOW Stack overflow detected. Typically caused by * allocating an instance of * @ref nrf_crypto_rng_temp_buffer_t * on the stack when using CC310 backend. * @retval NRF_ERROR_CRYPTO_BUSY RNG is busy. Rerun at a later time. */ ret_code_t nrf_crypto_rng_init(nrf_crypto_rng_context_t * p_context, nrf_crypto_rng_temp_buffer_t * p_temp_buffer); /**@brief Uninitialize the random number generator. * * @retval NRF_SUCCESS If RNG was uninitialized successfully. * @retval NRF_ERROR_CRYPTO_CONTEXT_NOT_INITIALIZED RNG has not been initialized. * @retval NRF_ERROR_CRYPTO_INTERNAL If an internal error occurred in the * nrf_crypto backend. * @retval NRF_ERROR_CRYPTO_BUSY RNG is busy. Rerun at a later time. */ ret_code_t nrf_crypto_rng_uninit(void); /**@brief Generate random data of given size. * * @details @ref nrf_crypto_rng_init must be called prior to this function unless * @ref NRF_CRYPTO_RNG_AUTO_INIT_ENABLED is enabled in @ref sdk_config. * * @param[in,out] p_target Buffer to hold the random generated data. * This buffer must be at least as large as the size parameter. * @param[in] size Length (in bytes) to generate random data for. * * @retval NRF_SUCCESS Data was generated successfully. * @retval NRF_ERROR_CRYPTO_NOT_INITIALIZED @ref nrf_crypto_init was not called prior to * this function. * @retval NRF_ERROR_CRYPTO_CONTEXT_NOT_INITIALIZED @ref nrf_crypto_rng_init was not called * prior to this function and * @ref NRF_CRYPTO_RNG_AUTO_INIT_ENABLED is * disabled. * @retval NRF_ERROR_CRYPTO_OUTPUT_NULL p_target was NULL. * @retval NRF_ERROR_CRYPTO_OUTPUT_LENGTH Size was 0 or larger than the backend * supports. * @retval NRF_ERROR_CRYPTO_INTERNAL If an internal error occurred in the * backend. * @retval NRF_ERROR_CRYPTO_STACK_OVERFLOW Stack overflow detected in * @ref nrf_crypto_rng_init when using auto * initialization. Typically caused by * allocating an instance of * @ref nrf_crypto_rng_temp_buffer_t * on the stack when using CC310 backend. * @retval NRF_ERROR_CRYPTO_BUSY RNG is busy. Rerun at a later time. */ ret_code_t nrf_crypto_rng_vector_generate(uint8_t * const p_target, size_t size); /**@brief Generate a vector of constrained random data of given size, between the specified min * and max values. * * @details @ref nrf_crypto_rng_init must be called prior to this function unless * @ref NRF_CRYPTO_RNG_AUTO_INIT_ENABLED is enabled in @ref sdk_config. * * All vectors are in big-endian format, with the most significant byte as the first * element / lowest address. * * @note This function may execute for a long time if the window between p_min and p_max is small. * * @param[in,out] p_target Buffer to hold the random generated data. * This buffer must be at least as large as the size parameter. * @param[in] p_min Byte array defining the lower limit of the random vector. * @param[in] p_max Byte array defining the upper limit of the random vector. * @param[in] size Length (in bytes) to generate random data for. Note that all three * buffers (p_target, p_min and p_max) must be of this size. * * @retval NRF_SUCCESS Data was generated successfully. * @retval NRF_ERROR_CRYPTO_NOT_INITIALIZED @ref nrf_crypto_init was not called prior to * this function. * @retval NRF_ERROR_CRYPTO_CONTEXT_NOT_INITIALIZED @ref nrf_crypto_rng_init was not called * prior to this function and * @ref NRF_CRYPTO_RNG_AUTO_INIT_ENABLED is * disabled. * @retval NRF_ERROR_CRYPTO_OUTPUT_NULL p_target was NULL. * @retval NRF_ERROR_CRYPTO_INPUT_NULL p_min or p_max was NULL. * @retval NRF_ERROR_CRYPTO_OUTPUT_LENGTH Size was 0 or larger than the backend * supports. * @retval NRF_ERROR_CRYPTO_INTERNAL If an internal error occurred in the * backend. * @retval NRF_ERROR_CRYPTO_STACK_OVERFLOW Stack overflow detected in * @ref nrf_crypto_rng_init when using auto * initialization. Typically caused by * allocating an instance of * @ref nrf_crypto_rng_temp_buffer_t * on the stack when using CC310 backend. * @retval NRF_ERROR_CRYPTO_BUSY RNG is busy. Rerun at a later time. */ ret_code_t nrf_crypto_rng_vector_generate_in_range(uint8_t * const p_target, uint8_t const * const p_min, uint8_t const * const p_max, size_t size); /** * @brief This function is used for reseeding the RNG with additional entropy. * * @details The backends will reseed automatically when required. This function can be used to * reseed at specific times and to provide additional data that is used to add personalized * randomness. * * @note Reseeding is not supported if using the nRF HW RNG backend without mbed TLS CTR-DRBG * (NRF_CRYPTO_BACKEND_NRF_HW_RNG_MBEDTLS_CTR_DRBG_ENABLED disabled in sdk_config.h). * * @warning The p_temp_buffer is 6112 bytes when the CC310 backend is used. Ensure that stack size * is sufficient if allocated on stack. * * @param[in,out] p_temp_buffer Temporary buffer needed during reseeding. It * is not used after the return of this function, and can be freed * at that point. Buffer is allocated internally if the pointer is * NULL, using the allocated defined by @ref NRF_CRYPTO_ALLOCATOR * in @c sdk_config.h. Use NULL if * @ref NRF_CRYPTO_RNG_STATIC_MEMORY_BUFFERS_ENABLED is enabled * in @ref sdk_config (recommended for most applications). * @param[in] p_input_data Optional input data used to increase the entropy. * @param[in] size Length of input data. Must be 0, 4, 8 or 12 for CC310. * * @retval NRF_SUCCESS Data was generated successfully. * @retval NRF_ERROR_CRYPTO_NOT_INITIALIZED @ref nrf_crypto_init was not called prior to * this function. * @retval NRF_ERROR_CRYPTO_CONTEXT_NOT_INITIALIZED @ref nrf_crypto_rng_init was not called * prior to this function and * @ref NRF_CRYPTO_RNG_AUTO_INIT_ENABLED is * disabled. * @retval NRF_ERROR_CRYPTO_INPUT_NULL p_temp_buffer was NULL or p_input_data was * NULL and size > 0 . * @retval NRF_ERROR_CRYPTO_INPUT_LENGTH Invalid input data size. * @retval NRF_ERROR_CRYPTO_FEATURE_UNAVAILABLE Reseeding not supported by backend. * @retval NRF_ERROR_CRYPTO_INTERNAL If an internal error occurred in the * backend. * @retval NRF_ERROR_CRYPTO_STACK_OVERFLOW Stack overflow detected. Typically caused by * allocating an instance of * @ref nrf_crypto_rng_temp_buffer_t * on the stack when using CC310 backend. * @retval NRF_ERROR_CRYPTO_BUSY RNG is busy. Rerun at a later time. */ ret_code_t nrf_crypto_rng_reseed(nrf_crypto_rng_temp_buffer_t * p_temp_buffer, uint8_t * p_input_data, size_t size); #ifdef __cplusplus } #endif /**@} */ #endif // NRF_CRYPTO_RNG_H__