1 /** 2 * \file entropy_poll.h 3 * 4 * \brief Platform-specific and custom entropy polling functions 5 * 6 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved 7 * SPDX-License-Identifier: Apache-2.0 8 * 9 * Licensed under the Apache License, Version 2.0 (the "License"); you may 10 * not use this file except in compliance with the License. 11 * You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 17 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 * 21 * This file is part of mbed TLS (https://tls.mbed.org) 22 */ 23 #ifndef MBEDTLS_ENTROPY_POLL_H 24 #define MBEDTLS_ENTROPY_POLL_H 25 26 #if !defined(MBEDTLS_CONFIG_FILE) 27 #include "config.h" 28 #else 29 #include MBEDTLS_CONFIG_FILE 30 #endif 31 32 #include <stddef.h> 33 34 #ifdef __cplusplus 35 extern "C" { 36 #endif 37 38 /* 39 * Default thresholds for built-in sources, in bytes 40 */ 41 #define MBEDTLS_ENTROPY_MIN_PLATFORM 32 /**< Minimum for platform source */ 42 #define MBEDTLS_ENTROPY_MIN_HAVEGE 32 /**< Minimum for HAVEGE */ 43 #define MBEDTLS_ENTROPY_MIN_HARDCLOCK 4 /**< Minimum for mbedtls_timing_hardclock() */ 44 #if !defined(MBEDTLS_ENTROPY_MIN_HARDWARE) 45 #define MBEDTLS_ENTROPY_MIN_HARDWARE 32 /**< Minimum for the hardware source */ 46 #endif 47 48 /** 49 * \brief Platform-specific entropy poll callback 50 */ 51 int mbedtls_platform_entropy_poll( void *data, 52 unsigned char *output, size_t len, size_t *olen ); 53 54 #if defined(MBEDTLS_TIMING_C) 55 /** 56 * \brief mbedtls_timing_hardclock-based entropy poll callback 57 */ 58 int mbedtls_hardclock_poll( void *data, 59 unsigned char *output, size_t len, size_t *olen ); 60 #endif 61 62 #if defined(MBEDTLS_ENTROPY_HARDWARE_ALT) 63 /** 64 * \brief Entropy poll callback for a hardware source 65 * 66 * \warning This is not provided by mbed TLS! 67 * See \c MBEDTLS_ENTROPY_HARDWARE_ALT in config.h. 68 * 69 * \note This must accept NULL as its first argument. 70 */ 71 int mbedtls_hardware_poll( void *data, 72 unsigned char *output, size_t len, size_t *olen ); 73 #endif 74 75 #ifdef __cplusplus 76 } 77 #endif 78 79 #endif /* entropy_poll.h */ 80