| 1 | /* |
| 2 | * RC4 encryption/decryption/pseudo-random number generator |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #ifndef AVUTIL_RC4_H |
| 22 | #define AVUTIL_RC4_H |
| 23 | |
| 24 | #include <stdint.h> |
| 25 | |
| 26 | struct AVRC4 { |
| 27 | uint8_t state[256]; |
| 28 | int x, y; |
| 29 | }; |
| 30 | |
| 31 | /** |
| 32 | * @brief Initializes an AVRC4 context. |
| 33 | * |
| 34 | * @param key_bits must be a multiple of 8 |
| 35 | * @param decrypt 0 for encryption, 1 for decryption, currently has no effect |
| 36 | */ |
| 37 | int av_rc4_init(struct AVRC4 *d, const uint8_t *key, int key_bits, int decrypt); |
| 38 | |
| 39 | /** |
| 40 | * @brief Encrypts / decrypts using the RC4 algorithm. |
| 41 | * |
| 42 | * @param count number of bytes |
| 43 | * @param dst destination array, can be equal to src |
| 44 | * @param src source array, can be equal to dst, may be NULL |
| 45 | * @param iv not (yet) used for RC4, should be NULL |
| 46 | * @param decrypt 0 for encryption, 1 for decryption, not (yet) used |
| 47 | */ |
| 48 | void av_rc4_crypt(struct AVRC4 *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt); |
| 49 | |
| 50 | #endif /* AVUTIL_RC4_H */ |