1 /** 2 * \file entropy_poll.h 3 * 4 * \brief Platform-specific and custom entropy polling functions 5 */ 6 /* 7 * Copyright The Mbed TLS Contributors 8 * SPDX-License-Identifier: Apache-2.0 9 * 10 * Licensed under the Apache License, Version 2.0 (the "License"); you may 11 * not use this file except in compliance with the License. 12 * You may obtain a copy of the License at 13 * 14 * http://www.apache.org/licenses/LICENSE-2.0 15 * 16 * Unless required by applicable law or agreed to in writing, software 17 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 18 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 19 * See the License for the specific language governing permissions and 20 * limitations under the License. 21 */ 22 #ifndef MBEDTLS_ENTROPY_POLL_H 23 #define MBEDTLS_ENTROPY_POLL_H 24 25 #if !defined(MBEDTLS_CONFIG_FILE) 26 #include "mbedtls/config.h" 27 #else 28 #include MBEDTLS_CONFIG_FILE 29 #endif 30 31 #include <stddef.h> 32 33 #ifdef __cplusplus 34 extern "C" { 35 #endif 36 37 /* 38 * Default thresholds for built-in sources, in bytes 39 */ 40 #define MBEDTLS_ENTROPY_MIN_PLATFORM 32 /**< Minimum for platform source */ 41 #define MBEDTLS_ENTROPY_MIN_HAVEGE 32 /**< Minimum for HAVEGE */ 42 #define MBEDTLS_ENTROPY_MIN_HARDCLOCK 4 /**< Minimum for mbedtls_timing_hardclock() */ 43 #if !defined(MBEDTLS_ENTROPY_MIN_HARDWARE) 44 #define MBEDTLS_ENTROPY_MIN_HARDWARE 32 /**< Minimum for the hardware source */ 45 #endif 46 47 /** 48 * \brief Entropy poll callback that provides 0 entropy. 49 */ 50 #if defined(MBEDTLS_TEST_NULL_ENTROPY) 51 int mbedtls_null_entropy_poll( void *data, 52 unsigned char *output, size_t len, size_t *olen ); 53 #endif 54 55 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY) 56 /** 57 * \brief Platform-specific entropy poll callback 58 */ 59 int mbedtls_platform_entropy_poll( void *data, 60 unsigned char *output, size_t len, size_t *olen ); 61 #endif 62 63 #if defined(MBEDTLS_HAVEGE_C) 64 /** 65 * \brief HAVEGE based entropy poll callback 66 * 67 * Requires an HAVEGE state as its data pointer. 68 */ 69 int mbedtls_havege_poll( void *data, 70 unsigned char *output, size_t len, size_t *olen ); 71 #endif 72 73 #if defined(MBEDTLS_TIMING_C) 74 /** 75 * \brief mbedtls_timing_hardclock-based entropy poll callback 76 */ 77 int mbedtls_hardclock_poll( void *data, 78 unsigned char *output, size_t len, size_t *olen ); 79 #endif 80 81 #if defined(MBEDTLS_ENTROPY_HARDWARE_ALT) 82 /** 83 * \brief Entropy poll callback for a hardware source 84 * 85 * \warning This is not provided by mbed TLS! 86 * See \c MBEDTLS_ENTROPY_HARDWARE_ALT in config.h. 87 * 88 * \note This must accept NULL as its first argument. 89 */ 90 int mbedtls_hardware_poll( void *data, 91 unsigned char *output, size_t len, size_t *olen ); 92 #endif 93 94 #if defined(MBEDTLS_ENTROPY_NV_SEED) 95 /** 96 * \brief Entropy poll callback for a non-volatile seed file 97 * 98 * \note This must accept NULL as its first argument. 99 */ 100 int mbedtls_nv_seed_poll( void *data, 101 unsigned char *output, size_t len, size_t *olen ); 102 #endif 103 104 #ifdef __cplusplus 105 } 106 #endif 107 108 #endif /* entropy_poll.h */ 109