1 /*
2  * Blowfish algorithm
3  * Copyright (c) 2012 Samuel Pitoiset
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_BLOWFISH_H
23 #define AVUTIL_BLOWFISH_H
24 
25 #include <stdint.h>
26 
27 /**
28  * @defgroup lavu_blowfish Blowfish
29  * @ingroup lavu_crypto
30  * @{
31  */
32 
33 #define AV_BF_ROUNDS 16
34 
35 typedef struct AVBlowfish {
36     uint32_t p[AV_BF_ROUNDS + 2];
37     uint32_t s[4][256];
38 } AVBlowfish;
39 
40 /**
41  * Allocate an AVBlowfish context.
42  */
43 AVBlowfish *av_blowfish_alloc(void);
44 
45 /**
46  * Initialize an AVBlowfish context.
47  *
48  * @param ctx an AVBlowfish context
49  * @param key a key
50  * @param key_len length of the key
51  */
52 void av_blowfish_init(struct AVBlowfish *ctx, const uint8_t *key, int key_len);
53 
54 /**
55  * Encrypt or decrypt a buffer using a previously initialized context.
56  *
57  * @param ctx an AVBlowfish context
58  * @param xl left four bytes halves of input to be encrypted
59  * @param xr right four bytes halves of input to be encrypted
60  * @param decrypt 0 for encryption, 1 for decryption
61  */
62 void av_blowfish_crypt_ecb(struct AVBlowfish *ctx, uint32_t *xl, uint32_t *xr,
63                            int decrypt);
64 
65 /**
66  * Encrypt or decrypt a buffer using a previously initialized context.
67  *
68  * @param ctx an AVBlowfish context
69  * @param dst destination array, can be equal to src
70  * @param src source array, can be equal to dst
71  * @param count number of 8 byte blocks
72  * @param iv initialization vector for CBC mode, if NULL ECB will be used
73  * @param decrypt 0 for encryption, 1 for decryption
74  */
75 void av_blowfish_crypt(struct AVBlowfish *ctx, uint8_t *dst, const uint8_t *src,
76                        int count, uint8_t *iv, int decrypt);
77 
78 /**
79  * @}
80  */
81 
82 #endif /* AVUTIL_BLOWFISH_H */
83