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 #include <stdint.h> 26 27 #include "attributes.h" 28 #include "version.h" 29 30 #define AES_CTR_KEY_SIZE (16) 31 #define AES_CTR_IV_SIZE (8) 32 33 struct AVAESCTR; 34 35 /** 36 * Allocate an AVAESCTR context. 37 */ 38 struct AVAESCTR *av_aes_ctr_alloc(void); 39 40 /** 41 * Initialize an AVAESCTR context. 42 * @param key encryption key, must have a length of AES_CTR_KEY_SIZE 43 */ 44 int av_aes_ctr_init(struct AVAESCTR *a, const uint8_t *key); 45 46 /** 47 * Release an AVAESCTR context. 48 */ 49 void av_aes_ctr_free(struct AVAESCTR *a); 50 51 /** 52 * Process a buffer using a previously initialized context. 53 * @param dst destination array, can be equal to src 54 * @param src source array, can be equal to dst 55 * @param size the size of src and dst 56 */ 57 void av_aes_ctr_crypt(struct AVAESCTR *a, uint8_t *dst, const uint8_t *src, int size); 58 59 /** 60 * Get the current iv 61 */ 62 const uint8_t* av_aes_ctr_get_iv(struct AVAESCTR *a); 63 64 /** 65 * Generate a random iv 66 */ 67 void av_aes_ctr_set_random_iv(struct AVAESCTR *a); 68 69 /** 70 * Forcefully change the 8-byte iv 71 */ 72 void av_aes_ctr_set_iv(struct AVAESCTR *a, const uint8_t* iv); 73 74 /** 75 * Forcefully change the "full" 16-byte iv, including the counter 76 */ 77 void av_aes_ctr_set_full_iv(struct AVAESCTR *a, const uint8_t* iv); 78 79 /** 80 * Increment the top 64 bit of the iv (performed after each frame) 81 */ 82 void av_aes_ctr_increment_iv(struct AVAESCTR *a); 83 84 /** 85 * @} 86 */ 87 88 #endif /* AVUTIL_AES_CTR_H */ 89