1 /* Interfaces for obtaining random bytes. 2 Copyright (C) 2016-2022 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #ifndef _SYS_RANDOM_H 20 #define _SYS_RANDOM_H 1 21 22 #include <features.h> 23 #include <sys/types.h> 24 25 /* Flags for use with getrandom. */ 26 #define GRND_NONBLOCK 0x01 27 #define GRND_RANDOM 0x02 28 #define GRND_INSECURE 0x04 29 30 __BEGIN_DECLS 31 32 /* Write LENGTH bytes of randomness starting at BUFFER. Return the 33 number of bytes written, or -1 on error. */ 34 ssize_t getrandom (void *__buffer, size_t __length, 35 unsigned int __flags) __wur 36 __attr_access ((__write_only__, 1, 2)); 37 38 /* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on 39 success or -1 on error. */ 40 int getentropy (void *__buffer, size_t __length) __wur 41 __attr_access ((__write_only__, 1, 2)); 42 43 __END_DECLS 44 45 #endif /* _SYS_RANDOM_H */ 46