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) 21 extern "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. 29 OPENSSL_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|. 33 OPENSSL_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|. 48 OPENSSL_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. 62 OPENSSL_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. 68 OPENSSL_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|. 75 OPENSSL_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. 79 OPENSSL_EXPORT void RAND_seed(const void *buf, int num); 80 81 // RAND_load_file returns a nonnegative number. 82 OPENSSL_EXPORT int RAND_load_file(const char *path, long num); 83 84 // RAND_file_name returns NULL. 85 OPENSSL_EXPORT const char *RAND_file_name(char *buf, size_t num); 86 87 // RAND_add does nothing. 88 OPENSSL_EXPORT void RAND_add(const void *buf, int num, double entropy); 89 90 // RAND_egd returns 255. 91 OPENSSL_EXPORT int RAND_egd(const char *); 92 93 // RAND_poll returns one. 94 OPENSSL_EXPORT int RAND_poll(void); 95 96 // RAND_status returns one. 97 OPENSSL_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. 102 struct 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|. 112 OPENSSL_EXPORT RAND_METHOD *RAND_SSLeay(void); 113 114 // RAND_get_rand_method returns |RAND_SSLeay()|. 115 OPENSSL_EXPORT const RAND_METHOD *RAND_get_rand_method(void); 116 117 // RAND_set_rand_method does nothing. 118 OPENSSL_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
