1 /* 2 * An implementation of the CAST128 algorithm as mentioned in RFC2144 3 * Copyright (c) 2014 Supraja Meedinti 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22 #ifndef AVUTIL_CAST5_H 23 #define AVUTIL_CAST5_H 24 25 #include <stdint.h> 26 27 28 /** 29 * @file 30 * @brief Public header for libavutil CAST5 algorithm 31 * @defgroup lavu_cast5 CAST5 32 * @ingroup lavu_crypto 33 * @{ 34 */ 35 36 extern const int av_cast5_size; 37 38 struct AVCAST5; 39 40 /** 41 * Allocate an AVCAST5 context 42 * To free the struct: av_free(ptr) 43 */ 44 struct AVCAST5 *av_cast5_alloc(void); 45 /** 46 * Initialize an AVCAST5 context. 47 * 48 * @param ctx an AVCAST5 context 49 * @param key a key of 5,6,...16 bytes used for encryption/decryption 50 * @param key_bits number of keybits: possible are 40,48,...,128 51 * @return 0 on success, less than 0 on failure 52 */ 53 int av_cast5_init(struct AVCAST5 *ctx, const uint8_t *key, int key_bits); 54 55 /** 56 * Encrypt or decrypt a buffer using a previously initialized context, ECB mode only 57 * 58 * @param ctx an AVCAST5 context 59 * @param dst destination array, can be equal to src 60 * @param src source array, can be equal to dst 61 * @param count number of 8 byte blocks 62 * @param decrypt 0 for encryption, 1 for decryption 63 */ 64 void av_cast5_crypt(struct AVCAST5 *ctx, uint8_t *dst, const uint8_t *src, int count, int decrypt); 65 66 /** 67 * Encrypt or decrypt a buffer using a previously initialized context 68 * 69 * @param ctx an AVCAST5 context 70 * @param dst destination array, can be equal to src 71 * @param src source array, can be equal to dst 72 * @param count number of 8 byte blocks 73 * @param iv initialization vector for CBC mode, NULL for ECB mode 74 * @param decrypt 0 for encryption, 1 for decryption 75 */ 76 void av_cast5_crypt2(struct AVCAST5 *ctx, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt); 77 /** 78 * @} 79 */ 80 #endif /* AVUTIL_CAST5_H */ 81