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RIOT/pkg/mbedtls/include/entropy_mbedtls_riot.h
2022-01-17 23:22:14 +01:00

82 lines
2.3 KiB
C

/*
* Copyright (C) 2020 HAW Hamburg
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @defgroup pkg_mbedtls_entropy Access API to Mbed TLS entropy module
* @ingroup pkg_mbedtls
*
* @{
* @file
* @brief Convenience functions to retrieve entropy from Mbed TLS. Direct
* use of the Mbed TLS API is also possible without this API.
*
* @author Peter Kietzmann <peter.kietzmann@haw-hamburg.de>
*
*/
#ifndef ENTROPY_MBEDTLS_RIOT_H
#define ENTROPY_MBEDTLS_RIOT_H
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Initialize the Mbed TLS entropy module.
*
* A context structure is allocated and managed internally.
* Connect all available entropy sources to the poll.
*
* @retval 0 if successful
* @retval MBEDTLS_ERR_ENTROPY_MAX_SOURCES on failure
*/
int entropy_mbedtls_riot_init(void);
/**
* @brief Retrieve entropy values after initialization.
*
* @pre Module is initialized already (i.e. @ref entropy_mbedtls_riot_init has been called).
*
* @param[out] output Pointer to the output buffer to fill with entropy values.
* @param[in] len Length of requested entropy in bytes.
*
* @retval 0 if successful
* @retval MBEDTLS_ERR_ENTROPY_SOURCE_FAILED if source failed
*/
int entropy_mbedtls_riot_retrieve(unsigned char *output, size_t len);
/**
* @brief Uninitialize the Mbed TLS entropy module.
*
* Frees the internally allocated context. Mbed TLS zeroizes the memory.
*/
void entropy_mbedtls_riot_uninit(void);
/**
* @brief Get entropy values.
*
* Convenience function. A context structure is allocated and managed
* internally. Requested entropy values are gathered and the context is
* uninitialized afterwards.
*
* @param[out] output Pointer to the output buffer to fill with entropy values.
* @param[in] len Length of requested entropy in bytes.
*
* @retval 0 if successful
* @retval MBEDTLS_ERR_ENTROPY_MAX_SOURCES on failure
* @retval MBEDTLS_ERR_ENTROPY_SOURCE_FAILED if source failed
*/
int entropy_mbedtls_riot_get(unsigned char *output, size_t len);
#ifdef __cplusplus
}
#endif
/** @} */
#endif /* ENTROPY_MBEDTLS_RIOT_H */