/*
* RC4 encryption/decryption/pseudo-random number generator
*
* 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_RC4_H
#define AVUTIL_RC4_H
#include <stdint.h>
/**
* @defgroup lavu_rc4 RC4
* @ingroup lavu_crypto
* @{
*/
typedef struct AVRC4 {
uint8_t state[256];
int x, y;
} AVRC4;
/**
* Allocate an AVRC4 context.
*/
AVRC4 *av_rc4_alloc(void);
/**
* @brief Initializes an AVRC4 context.
*
* @param key_bits must be a multiple of 8
* @param decrypt 0 for encryption, 1 for decryption, currently has no effect
* @return zero on success, negative value otherwise
*/
int av_rc4_init(struct AVRC4 *d, const uint8_t *key, int key_bits, int decrypt);
/**
* @brief Encrypts / decrypts using the RC4 algorithm.
*
* @param count number of bytes
* @param dst destination array, can be equal to src
* @param src source array, can be equal to dst, may be NULL
* @param iv not (yet) used for RC4, should be NULL
* @param decrypt 0 for encryption, 1 for decryption, not (yet) used
*/
void av_rc4_crypt(struct AVRC4 *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt);
/**
* @}
*/
#endif /* AVUTIL_RC4_H */