xtea.h (2834B)
1 /* 2 * A 32-bit implementation of the XTEA algorithm 3 * Copyright (c) 2012 Samuel Pitoiset 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_XTEA_H 23 #define AVUTIL_XTEA_H 24 25 #include <stdint.h> 26 27 /** 28 * @file 29 * @brief Public header for libavutil XTEA algorithm 30 * @defgroup lavu_xtea XTEA 31 * @ingroup lavu_crypto 32 * @{ 33 */ 34 35 typedef struct AVXTEA { 36 uint32_t key[16]; 37 } AVXTEA; 38 39 /** 40 * Allocate an AVXTEA context. 41 */ 42 AVXTEA *av_xtea_alloc(void); 43 44 /** 45 * Initialize an AVXTEA context. 46 * 47 * @param ctx an AVXTEA context 48 * @param key a key of 16 bytes used for encryption/decryption, 49 * interpreted as big endian 32 bit numbers 50 */ 51 void av_xtea_init(struct AVXTEA *ctx, const uint8_t key[16]); 52 53 /** 54 * Initialize an AVXTEA context. 55 * 56 * @param ctx an AVXTEA context 57 * @param key a key of 16 bytes used for encryption/decryption, 58 * interpreted as little endian 32 bit numbers 59 */ 60 void av_xtea_le_init(struct AVXTEA *ctx, const uint8_t key[16]); 61 62 /** 63 * Encrypt or decrypt a buffer using a previously initialized context, 64 * in big endian format. 65 * 66 * @param ctx an AVXTEA context 67 * @param dst destination array, can be equal to src 68 * @param src source array, can be equal to dst 69 * @param count number of 8 byte blocks 70 * @param iv initialization vector for CBC mode, if NULL then ECB will be used 71 * @param decrypt 0 for encryption, 1 for decryption 72 */ 73 void av_xtea_crypt(struct AVXTEA *ctx, uint8_t *dst, const uint8_t *src, 74 int count, uint8_t *iv, int decrypt); 75 76 /** 77 * Encrypt or decrypt a buffer using a previously initialized context, 78 * in little endian format. 79 * 80 * @param ctx an AVXTEA context 81 * @param dst destination array, can be equal to src 82 * @param src source array, can be equal to dst 83 * @param count number of 8 byte blocks 84 * @param iv initialization vector for CBC mode, if NULL then ECB will be used 85 * @param decrypt 0 for encryption, 1 for decryption 86 */ 87 void av_xtea_le_crypt(struct AVXTEA *ctx, uint8_t *dst, const uint8_t *src, 88 int count, uint8_t *iv, int decrypt); 89 90 /** 91 * @} 92 */ 93 94 #endif /* AVUTIL_XTEA_H */