1 /** 2 * \file havege.h 3 * 4 * \brief HAVEGE: HArdware Volatile Entropy Gathering and Expansion 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_HAVEGE_H 23 #define MBEDTLS_HAVEGE_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 #include <stdint.h> 33 34 #define MBEDTLS_HAVEGE_COLLECT_SIZE 1024 35 36 #ifdef __cplusplus 37 extern "C" { 38 #endif 39 40 /** 41 * \brief HAVEGE state structure 42 */ 43 typedef struct mbedtls_havege_state 44 { 45 uint32_t PT1, PT2, offset[2]; 46 uint32_t pool[MBEDTLS_HAVEGE_COLLECT_SIZE]; 47 uint32_t WALK[8192]; 48 } 49 mbedtls_havege_state; 50 51 /** 52 * \brief HAVEGE initialization 53 * 54 * \param hs HAVEGE state to be initialized 55 */ 56 void mbedtls_havege_init( mbedtls_havege_state *hs ); 57 58 /** 59 * \brief Clear HAVEGE state 60 * 61 * \param hs HAVEGE state to be cleared 62 */ 63 void mbedtls_havege_free( mbedtls_havege_state *hs ); 64 65 /** 66 * \brief HAVEGE rand function 67 * 68 * \param p_rng A HAVEGE state 69 * \param output Buffer to fill 70 * \param len Length of buffer 71 * 72 * \return 0 73 */ 74 int mbedtls_havege_random( void *p_rng, unsigned char *output, size_t len ); 75 76 #ifdef __cplusplus 77 } 78 #endif 79 80 #endif /* havege.h */ 81