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 #include <stddef.h> 28 29 #define MBEDTLS_HAVEGE_COLLECT_SIZE 1024 30 31 #ifdef __cplusplus 32 extern "C" { 33 #endif 34 35 /** 36 * \brief HAVEGE state structure 37 */ 38 typedef struct mbedtls_havege_state 39 { 40 int PT1, PT2, offset[2]; 41 int pool[MBEDTLS_HAVEGE_COLLECT_SIZE]; 42 int WALK[8192]; 43 } 44 mbedtls_havege_state; 45 46 /** 47 * \brief HAVEGE initialization 48 * 49 * \param hs HAVEGE state to be initialized 50 */ 51 void mbedtls_havege_init( mbedtls_havege_state *hs ); 52 53 /** 54 * \brief Clear HAVEGE state 55 * 56 * \param hs HAVEGE state to be cleared 57 */ 58 void mbedtls_havege_free( mbedtls_havege_state *hs ); 59 60 /** 61 * \brief HAVEGE rand function 62 * 63 * \param p_rng A HAVEGE state 64 * \param output Buffer to fill 65 * \param len Length of buffer 66 * 67 * \return 0 68 */ 69 int mbedtls_havege_random( void *p_rng, unsigned char *output, size_t len ); 70 71 #ifdef __cplusplus 72 } 73 #endif 74 75 #endif /* havege.h */ 76