common/mbedtls/entropy_poll.h

   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 */