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 (C) 2006-2016, ARM Limited, All Rights Reserved
   8  *  SPDX-License-Identifier: GPL-2.0
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  23  *
  24  *  This file is part of mbed TLS (https://tls.mbed.org)
  25  */
  26 #ifndef MBEDTLS_ENTROPY_POLL_H
  27 #define MBEDTLS_ENTROPY_POLL_H
  28
  29 #if !defined(MBEDTLS_CONFIG_FILE)
  30 #include "config.h"
  31 #else
  32 #include MBEDTLS_CONFIG_FILE
  33 #endif
  34
  35 #include <stddef.h>
  36
  37 #ifdef __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 /*
  42  * Default thresholds for built-in sources, in bytes
  43  */
  44 #define MBEDTLS_ENTROPY_MIN_PLATFORM     32     /**< Minimum for platform source    */
  45 #define MBEDTLS_ENTROPY_MIN_HAVEGE       32     /**< Minimum for HAVEGE             */
  46 #define MBEDTLS_ENTROPY_MIN_HARDCLOCK     4     /**< Minimum for mbedtls_timing_hardclock()        */
  47 #if !defined(MBEDTLS_ENTROPY_MIN_HARDWARE)
  48 #define MBEDTLS_ENTROPY_MIN_HARDWARE     32     /**< Minimum for the hardware source */
  49 #endif
  50
  51 /**
  52  * \brief           Entropy poll callback that provides 0 entropy.
  53  */
  54 #if defined(MBEDTLS_TEST_NULL_ENTROPY)
  55     int mbedtls_null_entropy_poll( void *data,
  56                                 unsigned char *output, size_t len, size_t *olen );
  57 #endif
  58
  59 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
  60 /**
  61  * \brief           Platform-specific entropy poll callback
  62  */
  63 int mbedtls_platform_entropy_poll( void *data,
  64                            unsigned char *output, size_t len, size_t *olen );
  65 #endif
  66
  67 #if defined(MBEDTLS_HAVEGE_C)
  68 /**
  69  * \brief           HAVEGE based entropy poll callback
  70  *
  71  * Requires an HAVEGE state as its data pointer.
  72  */
  73 int mbedtls_havege_poll( void *data,
  74                  unsigned char *output, size_t len, size_t *olen );
  75 #endif
  76
  77 #if defined(MBEDTLS_TIMING_C)
  78 /**
  79  * \brief           mbedtls_timing_hardclock-based entropy poll callback
  80  */
  81 int mbedtls_hardclock_poll( void *data,
  82                     unsigned char *output, size_t len, size_t *olen );
  83 #endif
  84
  85 #if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
  86 /**
  87  * \brief           Entropy poll callback for a hardware source
  88  *
  89  * \warning         This is not provided by mbed TLS!
  90  *                  See \c MBEDTLS_ENTROPY_HARDWARE_ALT in config.h.
  91  *
  92  * \note            This must accept NULL as its first argument.
  93  */
  94 int mbedtls_hardware_poll( void *data,
  95                            unsigned char *output, size_t len, size_t *olen );
  96 #endif
  97
  98 #if defined(MBEDTLS_ENTROPY_NV_SEED)
  99 /**
 100  * \brief           Entropy poll callback for a non-volatile seed file
 101  *
 102  * \note            This must accept NULL as its first argument.
 103  */
 104 int mbedtls_nv_seed_poll( void *data,
 105                           unsigned char *output, size_t len, size_t *olen );
 106 #endif
 107
 108 #ifdef __cplusplus
 109 }
 110 #endif
 111
 112 #endif /* entropy_poll.h */