yading@11: /*
yading@11:  * RC4 encryption/decryption/pseudo-random number generator
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #ifndef AVUTIL_RC4_H
yading@11: #define AVUTIL_RC4_H
yading@11: 
yading@11: #include <stdint.h>
yading@11: 
yading@11: struct AVRC4 {
yading@11:     uint8_t state[256];
yading@11:     int x, y;
yading@11: };
yading@11: 
yading@11: /**
yading@11:  * @brief Initializes an AVRC4 context.
yading@11:  *
yading@11:  * @param key_bits must be a multiple of 8
yading@11:  * @param decrypt 0 for encryption, 1 for decryption, currently has no effect
yading@11:  */
yading@11: int av_rc4_init(struct AVRC4 *d, const uint8_t *key, int key_bits, int decrypt);
yading@11: 
yading@11: /**
yading@11:  * @brief Encrypts / decrypts using the RC4 algorithm.
yading@11:  *
yading@11:  * @param count number of bytes
yading@11:  * @param dst destination array, can be equal to src
yading@11:  * @param src source array, can be equal to dst, may be NULL
yading@11:  * @param iv not (yet) used for RC4, should be NULL
yading@11:  * @param decrypt 0 for encryption, 1 for decryption, not (yet) used
yading@11:  */
yading@11: void av_rc4_crypt(struct AVRC4 *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt);
yading@11: 
yading@11: #endif /* AVUTIL_RC4_H */