ffmpeg/libavutil/aes_ctr.h

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/*
* AES-CTR cipher
* Copyright (c) 2015 Eran Kornblau <erankor at gmail dot 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_AES_CTR_H
#define AVUTIL_AES_CTR_H
/**
* @defgroup lavu_aes_ctr AES-CTR
* @ingroup lavu_crypto
* @{
*/
#include <stdint.h>
#include "attributes.h"
#define AES_CTR_KEY_SIZE (16)
#define AES_CTR_IV_SIZE (8)
struct AVAESCTR;
/**
* Allocate an AVAESCTR context.
*/
struct AVAESCTR *av_aes_ctr_alloc(void);
/**
* Initialize an AVAESCTR context.
*
* @param a The AVAESCTR context to initialize
* @param key encryption key, must have a length of AES_CTR_KEY_SIZE
*/
int av_aes_ctr_init(struct AVAESCTR *a, const uint8_t *key);
/**
* Release an AVAESCTR context.
*
* @param a The AVAESCTR context
*/
void av_aes_ctr_free(struct AVAESCTR *a);
/**
* Process a buffer using a previously initialized context.
*
* @param a The AVAESCTR context
* @param dst destination array, can be equal to src
* @param src source array, can be equal to dst
* @param size the size of src and dst
*/
void av_aes_ctr_crypt(struct AVAESCTR *a, uint8_t *dst, const uint8_t *src, int size);
/**
* Get the current iv
*/
const uint8_t* av_aes_ctr_get_iv(struct AVAESCTR *a);
/**
* Generate a random iv
*/
void av_aes_ctr_set_random_iv(struct AVAESCTR *a);
/**
* Forcefully change the 8-byte iv
*/
void av_aes_ctr_set_iv(struct AVAESCTR *a, const uint8_t* iv);
/**
* Forcefully change the "full" 16-byte iv, including the counter
*/
void av_aes_ctr_set_full_iv(struct AVAESCTR *a, const uint8_t* iv);
/**
* Increment the top 64 bit of the iv (performed after each frame)
*/
void av_aes_ctr_increment_iv(struct AVAESCTR *a);
/**
* @}
*/
#endif /* AVUTIL_AES_CTR_H */