ffmpeg/libavutil/random_seed.h

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/*
* Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_RANDOM_SEED_H
#define AVUTIL_RANDOM_SEED_H
#include <stddef.h>
#include <stdint.h>
/**
* @addtogroup lavu_crypto
* @{
*/
/**
* Get a seed to use in conjunction with random functions.
* This function tries to provide a good seed at a best effort bases.
* Its possible to call this function multiple times if more bits are needed.
* It can be quite slow, which is why it should only be used as seed for a faster
* PRNG. The quality of the seed depends on the platform.
*/
uint32_t av_get_random_seed(void);
/**
* Generate cryptographically secure random data, i.e. suitable for use as
* encryption keys and similar.
*
* @param buf buffer into which the random data will be written
* @param len size of buf in bytes
*
* @retval 0 success, len bytes of random data was written
* into buf
* @retval "a negative AVERROR code" random data could not be generated
*/
int av_random_bytes(uint8_t *buf, size_t len);
/**
* @}
*/
#endif /* AVUTIL_RANDOM_SEED_H */