1 /*
2  * DES encryption/decryption
3  * Copyright (c) 2007 Reimar Doeffinger
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_DES_H
23 #define AVUTIL_DES_H
24 
25 #include <stdint.h>
26 
27 /**
28  * @defgroup lavu_des DES
29  * @ingroup lavu_crypto
30  * @{
31  */
32 
33 typedef struct AVDES {
34     uint64_t round_keys[3][16];
35     int triple_des;
36 } AVDES;
37 
38 /**
39  * Allocate an AVDES context.
40  */
41 AVDES *av_des_alloc(void);
42 
43 /**
44  * @brief Initializes an AVDES context.
45  *
46  * @param key_bits must be 64 or 192
47  * @param decrypt 0 for encryption/CBC-MAC, 1 for decryption
48  * @return zero on success, negative value otherwise
49  */
50 int av_des_init(struct AVDES *d, const uint8_t *key, int key_bits, int decrypt);
51 
52 /**
53  * @brief Encrypts / decrypts using the DES algorithm.
54  *
55  * @param count number of 8 byte blocks
56  * @param dst destination array, can be equal to src, must be 8-byte aligned
57  * @param src source array, can be equal to dst, must be 8-byte aligned, may be NULL
58  * @param iv initialization vector for CBC mode, if NULL then ECB will be used,
59  *           must be 8-byte aligned
60  * @param decrypt 0 for encryption, 1 for decryption
61  */
62 void av_des_crypt(struct AVDES *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt);
63 
64 /**
65  * @brief Calculates CBC-MAC using the DES algorithm.
66  *
67  * @param count number of 8 byte blocks
68  * @param dst destination array, can be equal to src, must be 8-byte aligned
69  * @param src source array, can be equal to dst, must be 8-byte aligned, may be NULL
70  */
71 void av_des_mac(struct AVDES *d, uint8_t *dst, const uint8_t *src, int count);
72 
73 /**
74  * @}
75  */
76 
77 #endif /* AVUTIL_DES_H */
78