1/* Copyright (c) 2014, Google Inc. 2 * 3 * Permission to use, copy, modify, and/or distribute this software for any 4 * purpose with or without fee is hereby granted, provided that the above 5 * copyright notice and this permission notice appear in all copies. 6 * 7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ 14 15#ifndef OPENSSL_HEADER_RAND_H 16#define OPENSSL_HEADER_RAND_H 17 18#include <openssl/base.h> 19 20#if defined(__cplusplus) 21extern "C" { 22#endif 23 24 25// Random number generation. 26 27 28// RAND_bytes writes |len| bytes of random data to |buf| and returns one. 29OPENSSL_EXPORT int RAND_bytes(uint8_t *buf, size_t len); 30 31// RAND_cleanup frees any resources used by the RNG. This is not safe if other 32// threads might still be calling |RAND_bytes|. 33OPENSSL_EXPORT void RAND_cleanup(void); 34 35 36// Obscure functions. 37 38#if !defined(OPENSSL_WINDOWS) 39// RAND_set_urandom_fd causes the module to use a copy of |fd| for system 40// randomness rather opening /dev/urandom internally. The caller retains 41// ownership of |fd| and is at liberty to close it at any time. This is useful 42// if, due to a sandbox, /dev/urandom isn't available. If used, it must be 43// called before the first call to |RAND_bytes|, and it is mutually exclusive 44// with |RAND_enable_fork_unsafe_buffering|. 45// 46// |RAND_set_urandom_fd| does not buffer any entropy, so it is safe to call 47// |fork| at any time after calling |RAND_set_urandom_fd|. 48OPENSSL_EXPORT void RAND_set_urandom_fd(int fd); 49 50// RAND_enable_fork_unsafe_buffering enables efficient buffered reading of 51// /dev/urandom. It adds an overhead of a few KB of memory per thread. It must 52// be called before the first call to |RAND_bytes| and it is mutually exclusive 53// with calls to |RAND_set_urandom_fd|. 54// 55// If |fd| is non-negative then a copy of |fd| will be used rather than opening 56// /dev/urandom internally. Like |RAND_set_urandom_fd|, the caller retains 57// ownership of |fd|. If |fd| is negative then /dev/urandom will be opened and 58// any error from open(2) crashes the address space. 59// 60// It has an unusual name because the buffer is unsafe across calls to |fork|. 61// Hence, this function should never be called by libraries. 62OPENSSL_EXPORT void RAND_enable_fork_unsafe_buffering(int fd); 63#endif 64 65#if defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE) 66// RAND_reset_for_fuzzing resets the fuzzer-only deterministic RNG. This 67// function is only defined in the fuzzer-only build configuration. 68OPENSSL_EXPORT void RAND_reset_for_fuzzing(void); 69#endif 70 71 72// Deprecated functions 73 74// RAND_pseudo_bytes is a wrapper around |RAND_bytes|. 75OPENSSL_EXPORT int RAND_pseudo_bytes(uint8_t *buf, size_t len); 76 77// RAND_seed reads a single byte of random data to ensure that any file 78// descriptors etc are opened. 79OPENSSL_EXPORT void RAND_seed(const void *buf, int num); 80 81// RAND_load_file returns a nonnegative number. 82OPENSSL_EXPORT int RAND_load_file(const char *path, long num); 83 84// RAND_file_name returns NULL. 85OPENSSL_EXPORT const char *RAND_file_name(char *buf, size_t num); 86 87// RAND_add does nothing. 88OPENSSL_EXPORT void RAND_add(const void *buf, int num, double entropy); 89 90// RAND_egd returns 255. 91OPENSSL_EXPORT int RAND_egd(const char *); 92 93// RAND_poll returns one. 94OPENSSL_EXPORT int RAND_poll(void); 95 96// RAND_status returns one. 97OPENSSL_EXPORT int RAND_status(void); 98 99// rand_meth_st is typedefed to |RAND_METHOD| in base.h. It isn't used; it 100// exists only to be the return type of |RAND_SSLeay|. It's 101// external so that variables of this type can be initialized. 102struct rand_meth_st { 103 void (*seed) (const void *buf, int num); 104 int (*bytes) (uint8_t *buf, size_t num); 105 void (*cleanup) (void); 106 void (*add) (const void *buf, int num, double entropy); 107 int (*pseudorand) (uint8_t *buf, size_t num); 108 int (*status) (void); 109}; 110 111// RAND_SSLeay returns a pointer to a dummy |RAND_METHOD|. 112OPENSSL_EXPORT RAND_METHOD *RAND_SSLeay(void); 113 114// RAND_get_rand_method returns |RAND_SSLeay()|. 115OPENSSL_EXPORT const RAND_METHOD *RAND_get_rand_method(void); 116 117// RAND_set_rand_method does nothing. 118OPENSSL_EXPORT void RAND_set_rand_method(const RAND_METHOD *); 119 120 121#if defined(__cplusplus) 122} // extern C 123#endif 124 125#endif // OPENSSL_HEADER_RAND_H 126