1 /** 2 * \file havege.h 3 * 4 * \brief HAVEGE: HArdware Volatile Entropy Gathering and Expansion 5 */ 6 /* 7 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 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 * This file is part of mbed TLS (https://tls.mbed.org) 23 */ 24 #ifndef MBEDTLS_HAVEGE_H 25 #define MBEDTLS_HAVEGE_H 26 27 #if !defined(MBEDTLS_CONFIG_FILE) 28 #include "config.h" 29 #else 30 #include MBEDTLS_CONFIG_FILE 31 #endif 32 33 #include <stddef.h> 34 35 #define MBEDTLS_HAVEGE_COLLECT_SIZE 1024 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 /** 42 * \brief HAVEGE state structure 43 */ 44 typedef struct mbedtls_havege_state 45 { 46 int PT1, PT2, offset[2]; 47 int pool[MBEDTLS_HAVEGE_COLLECT_SIZE]; 48 int WALK[8192]; 49 } 50 mbedtls_havege_state; 51 52 /** 53 * \brief HAVEGE initialization 54 * 55 * \param hs HAVEGE state to be initialized 56 */ 57 void mbedtls_havege_init( mbedtls_havege_state *hs ); 58 59 /** 60 * \brief Clear HAVEGE state 61 * 62 * \param hs HAVEGE state to be cleared 63 */ 64 void mbedtls_havege_free( mbedtls_havege_state *hs ); 65 66 /** 67 * \brief HAVEGE rand function 68 * 69 * \param p_rng A HAVEGE state 70 * \param output Buffer to fill 71 * \param len Length of buffer 72 * 73 * \return 0 74 */ 75 int mbedtls_havege_random( void *p_rng, unsigned char *output, size_t len ); 76 77 #ifdef __cplusplus 78 } 79 #endif 80 81 #endif /* havege.h */ 82