aes_ctr.h (2443B)
1 /* 2 * AES-CTR cipher 3 * Copyright (c) 2015 Eran Kornblau <erankor at gmail dot com> 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_AES_CTR_H 23 #define AVUTIL_AES_CTR_H 24 25 /** 26 * @defgroup lavu_aes_ctr AES-CTR 27 * @ingroup lavu_crypto 28 * @{ 29 */ 30 31 #include <stdint.h> 32 33 #include "attributes.h" 34 35 #define AES_CTR_KEY_SIZE (16) 36 #define AES_CTR_IV_SIZE (8) 37 38 struct AVAESCTR; 39 40 /** 41 * Allocate an AVAESCTR context. 42 */ 43 struct AVAESCTR *av_aes_ctr_alloc(void); 44 45 /** 46 * Initialize an AVAESCTR context. 47 * 48 * @param a The AVAESCTR context to initialize 49 * @param key encryption key, must have a length of AES_CTR_KEY_SIZE 50 */ 51 int av_aes_ctr_init(struct AVAESCTR *a, const uint8_t *key); 52 53 /** 54 * Release an AVAESCTR context. 55 * 56 * @param a The AVAESCTR context 57 */ 58 void av_aes_ctr_free(struct AVAESCTR *a); 59 60 /** 61 * Process a buffer using a previously initialized context. 62 * 63 * @param a The AVAESCTR context 64 * @param dst destination array, can be equal to src 65 * @param src source array, can be equal to dst 66 * @param size the size of src and dst 67 */ 68 void av_aes_ctr_crypt(struct AVAESCTR *a, uint8_t *dst, const uint8_t *src, int size); 69 70 /** 71 * Get the current iv 72 */ 73 const uint8_t* av_aes_ctr_get_iv(struct AVAESCTR *a); 74 75 /** 76 * Generate a random iv 77 */ 78 void av_aes_ctr_set_random_iv(struct AVAESCTR *a); 79 80 /** 81 * Forcefully change the 8-byte iv 82 */ 83 void av_aes_ctr_set_iv(struct AVAESCTR *a, const uint8_t* iv); 84 85 /** 86 * Forcefully change the "full" 16-byte iv, including the counter 87 */ 88 void av_aes_ctr_set_full_iv(struct AVAESCTR *a, const uint8_t* iv); 89 90 /** 91 * Increment the top 64 bit of the iv (performed after each frame) 92 */ 93 void av_aes_ctr_increment_iv(struct AVAESCTR *a); 94 95 /** 96 * @} 97 */ 98 99 #endif /* AVUTIL_AES_CTR_H */