| /* |

| * RC4 encryption/decryption/pseudo-random number generator |

| * |

| * This file is part of FFmpeg. |

| * |

| * FFmpeg is free software; you can redistribute it and/or |

| * modify it under the terms of the GNU Lesser General Public |

| * License as published by the Free Software Foundation; either |

| * version 2.1 of the License, or (at your option) any later version. |

| * |

| * FFmpeg is distributed in the hope that it will be useful, |

| * but WITHOUT ANY WARRANTY; without even the implied warranty of |

| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |

| * Lesser General Public License for more details. |

| * |

| * You should have received a copy of the GNU Lesser General Public |

| * License along with FFmpeg; if not, write to the Free Software |

| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |

| */ |

| |

| #ifndef AVUTIL_RC4_H |

| #define AVUTIL_RC4_H |

| |

| #include <stdint.h> |

| |

| /** |

| * @defgroup lavu_rc4 RC4 |

| * @ingroup lavu_crypto |

| * @{ |

| */ |

| |

| typedef struct AVRC4 { |

| uint8_t state[256]; |

| int x, y; |

| } AVRC4; |

| |

| /** |

| * Allocate an AVRC4 context. |

| */ |

| AVRC4 *av_rc4_alloc(void); |

| |

| /** |

| * @brief Initializes an AVRC4 context. |

| * |

| * @param key_bits must be a multiple of 8 |

| * @param decrypt 0 for encryption, 1 for decryption, currently has no effect |

| * @return zero on success, negative value otherwise |

| */ |

| int av_rc4_init(struct AVRC4 *d, const uint8_t *key, int key_bits, int decrypt); |

| |

| /** |

| * @brief Encrypts / decrypts using the RC4 algorithm. |

| * |

| * @param count number of bytes |

| * @param dst destination array, can be equal to src |

| * @param src source array, can be equal to dst, may be NULL |

| * @param iv not (yet) used for RC4, should be NULL |

| * @param decrypt 0 for encryption, 1 for decryption, not (yet) used |

| */ |

| void av_rc4_crypt(struct AVRC4 *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt); |

| |

| /** |

| * @} |

| */ |

| |

| #endif /* AVUTIL_RC4_H */ |