blob: 029cd2ad58b9dd3850c22703a60f73d6486da888
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 | /** |
27 | * @defgroup lavu_rc4 RC4 |
28 | * @ingroup lavu_crypto |
29 | * @{ |
30 | */ |
31 | |
32 | typedef struct AVRC4 { |
33 | uint8_t state[256]; |
34 | int x, y; |
35 | } AVRC4; |
36 | |
37 | /** |
38 | * Allocate an AVRC4 context. |
39 | */ |
40 | AVRC4 *av_rc4_alloc(void); |
41 | |
42 | /** |
43 | * @brief Initializes an AVRC4 context. |
44 | * |
45 | * @param key_bits must be a multiple of 8 |
46 | * @param decrypt 0 for encryption, 1 for decryption, currently has no effect |
47 | * @return zero on success, negative value otherwise |
48 | */ |
49 | int av_rc4_init(struct AVRC4 *d, const uint8_t *key, int key_bits, int decrypt); |
50 | |
51 | /** |
52 | * @brief Encrypts / decrypts using the RC4 algorithm. |
53 | * |
54 | * @param count number of bytes |
55 | * @param dst destination array, can be equal to src |
56 | * @param src source array, can be equal to dst, may be NULL |
57 | * @param iv not (yet) used for RC4, should be NULL |
58 | * @param decrypt 0 for encryption, 1 for decryption, not (yet) used |
59 | */ |
60 | void av_rc4_crypt(struct AVRC4 *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt); |
61 | |
62 | /** |
63 | * @} |
64 | */ |
65 | |
66 | #endif /* AVUTIL_RC4_H */ |
67 |