1 /* 2 * Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 /* 11 * Licensed under the Apache License 2.0 (the "License"); 12 * you may not use this file except in compliance with the License. 13 * You may obtain a copy of the License at 14 * https://www.openssl.org/source/license.html 15 * or in the file LICENSE in the source distribution. 16 */ 17 18 #ifndef OSSL_CRYPTO_RAND_H 19 # define OSSL_CRYPTO_RAND_H 20 # pragma once 21 22 # include <openssl/rand.h> 23 # include "crypto/rand_pool.h" 24 25 # if defined(__APPLE__) && !defined(OPENSSL_NO_APPLE_CRYPTO_RANDOM) 26 # include <Availability.h> 27 # if (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101200) || \ 28 (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED >= 80000) 29 # define OPENSSL_APPLE_CRYPTO_RANDOM 1 30 # include <CommonCrypto/CommonCryptoError.h> 31 # include <CommonCrypto/CommonRandom.h> 32 # endif 33 # endif 34 35 /* 36 * Defines related to seed sources 37 */ 38 #ifndef DEVRANDOM 39 /* 40 * set this to a comma-separated list of 'random' device files to try out. By 41 * default, we will try to read at least one of these files 42 */ 43 # define DEVRANDOM "/dev/urandom", "/dev/random", "/dev/hwrng", "/dev/srandom" 44 # if defined(__linux) && !defined(__ANDROID__) 45 # ifndef DEVRANDOM_WAIT 46 # define DEVRANDOM_WAIT "/dev/random" 47 # endif 48 /* 49 * Linux kernels 4.8 and later changes how their random device works and there 50 * is no reliable way to tell that /dev/urandom has been seeded -- getentropy(2) 51 * should be used instead. 52 */ 53 # ifndef DEVRANDOM_SAFE_KERNEL 54 # define DEVRANDOM_SAFE_KERNEL 4, 8 55 # endif 56 /* 57 * Some operating systems do not permit select(2) on their random devices, 58 * defining this to zero will force the use of read(2) to extract one byte 59 * from /dev/random. 60 */ 61 # ifndef DEVRANDM_WAIT_USE_SELECT 62 # define DEVRANDM_WAIT_USE_SELECT 1 63 # endif 64 /* 65 * Define the shared memory identifier used to indicate if the operating 66 * system has properly seeded the DEVRANDOM source. 67 */ 68 # ifndef OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID 69 # define OPENSSL_RAND_SEED_DEVRANDOM_SHM_ID 114 70 # endif 71 72 # endif 73 #endif 74 75 #if !defined(OPENSSL_NO_EGD) && !defined(DEVRANDOM_EGD) 76 /* 77 * set this to a comma-separated list of 'egd' sockets to try out. These 78 * sockets will be tried in the order listed in case accessing the device 79 * files listed in DEVRANDOM did not return enough randomness. 80 */ 81 # define DEVRANDOM_EGD "/var/run/egd-pool", "/dev/egd-pool", "/etc/egd-pool", "/etc/entropy" 82 #endif 83 84 void ossl_rand_cleanup_int(void); 85 86 /* 87 * Initialise the random pool reseeding sources. 88 * 89 * Returns 1 on success and 0 on failure. 90 */ 91 int ossl_rand_pool_init(void); 92 93 /* 94 * Finalise the random pool reseeding sources. 95 */ 96 void ossl_rand_pool_cleanup(void); 97 98 /* 99 * Control the random pool use of open file descriptors. 100 */ 101 void ossl_rand_pool_keep_random_devices_open(int keep); 102 103 /* 104 * Configuration 105 */ 106 void ossl_random_add_conf_module(void); 107 108 /* 109 * Get and cleanup random seed material. 110 */ 111 size_t ossl_rand_get_entropy(ossl_unused const OSSL_CORE_HANDLE *handle, 112 unsigned char **pout, int entropy, 113 size_t min_len, size_t max_len); 114 void ossl_rand_cleanup_entropy(ossl_unused const OSSL_CORE_HANDLE *handle, 115 unsigned char *buf, size_t len); 116 size_t ossl_rand_get_nonce(ossl_unused const OSSL_CORE_HANDLE *handle, 117 unsigned char **pout, size_t min_len, size_t max_len, 118 const void *salt, size_t salt_len); 119 void ossl_rand_cleanup_nonce(ossl_unused const OSSL_CORE_HANDLE *handle, 120 unsigned char *buf, size_t len); 121 122 /* 123 * Get seeding material from the operating system sources. 124 */ 125 size_t ossl_pool_acquire_entropy(RAND_POOL *pool); 126 int ossl_pool_add_nonce_data(RAND_POOL *pool); 127 128 #endif 129
