twofish.h

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/*
 * An implementation of the TwoFish algorithm
 * Copyright (c) 2015 Supraja Meedinti
 *
 * 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_TWOFISH_H
#define AVUTIL_TWOFISH_H

#include <stdint.h>


/**
  * @file
  * @brief Public header for libavutil TWOFISH algorithm
  * @defgroup lavu_twofish TWOFISH
  * @ingroup lavu_crypto
  * @{
  */

extern const int av_twofish_size;

struct AVTWOFISH;

/**
  * Allocate an AVTWOFISH context
  * To free the struct: av_free(ptr)
  */
struct AVTWOFISH *av_twofish_alloc(void);

/**
  * Initialize an AVTWOFISH context.
  *
  * @param ctx an AVTWOFISH context
  * @param key a key of size ranging from 1 to 32 bytes used for encryption/decryption
  * @param key_bits number of keybits: 128, 192, 256 If less than the required, padded with zeroes to nearest valid value; return value is 0 if key_bits is 128/192/256, -1 if less than 0, 1 otherwise
 */
int av_twofish_init(struct AVTWOFISH *ctx, const uint8_t *key, int key_bits);

/**
  * Encrypt or decrypt a buffer using a previously initialized context
  *
  * @param ctx an AVTWOFISH context
  * @param dst destination array, can be equal to src
  * @param src source array, can be equal to dst
  * @param count number of 16 byte blocks
  * @paran iv initialization vector for CBC mode, NULL for ECB mode
  * @param decrypt 0 for encryption, 1 for decryption
 */
void av_twofish_crypt(struct AVTWOFISH *ctx, uint8_t *dst, const uint8_t *src, int count, uint8_t* iv, int decrypt);

/**
 * @}
 */
#endif /* AVUTIL_TWOFISH_H */