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 66 /* Deprecated functions */ 67 68 /* RAND_pseudo_bytes is a wrapper around |RAND_bytes|. */ 69 OPENSSL_EXPORT int RAND_pseudo_bytes(uint8_t *buf, size_t len); 70 71 /* RAND_seed reads a single byte of random data to ensure that any file 72 * descriptors etc are opened. */ 73 OPENSSL_EXPORT void RAND_seed(const void *buf, int num); 74 75 /* RAND_load_file returns a nonnegative number. */ 76 OPENSSL_EXPORT int RAND_load_file(const char *path, long num); 77 78 /* RAND_add does nothing. */ 79 OPENSSL_EXPORT void RAND_add(const void *buf, int num, double entropy); 80 81 /* RAND_egd returns 255. */ 82 OPENSSL_EXPORT int RAND_egd(const char *); 83 84 /* RAND_poll returns one. */ 85 OPENSSL_EXPORT int RAND_poll(void); 86 87 /* RAND_status returns one. */ 88 OPENSSL_EXPORT int RAND_status(void); 89 90 /* rand_meth_st is typedefed to |RAND_METHOD| in base.h. It isn't used; it 91 * exists only to be the return type of |RAND_SSLeay|. It's 92 * external so that variables of this type can be initialized. */ 93 struct rand_meth_st { 94 void (*seed) (const void *buf, int num); 95 int (*bytes) (uint8_t *buf, size_t num); 96 void (*cleanup) (void); 97 void (*add) (const void *buf, int num, double entropy); 98 int (*pseudorand) (uint8_t *buf, size_t num); 99 int (*status) (void); 100 }; 101 102 /* RAND_SSLeay returns a pointer to a dummy |RAND_METHOD|. */ 103 OPENSSL_EXPORT RAND_METHOD *RAND_SSLeay(void); 104 105 /* RAND_set_rand_method does nothing. */ 106 OPENSSL_EXPORT void RAND_set_rand_method(const RAND_METHOD *); 107 108 109 #if defined(__cplusplus) 110 } /* extern C */ 111 #endif 112 113 #endif /* OPENSSL_HEADER_RAND_H */ 114