1 /* Interfaces for obtaining random bytes.
2    Copyright (C) 2016-2021 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 
37 /* Write LENGTH bytes of randomness starting at BUFFER.  Return 0 on
38    success or -1 on error.  */
39 int getentropy (void *__buffer, size_t __length) __wur;
40 
41 __END_DECLS
42 
43 #endif /* _SYS_RANDOM_H */
44