chacha.h
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1 /*
2  * Copyright (C) 2008 D. J. Bernstein (dedicated to the public domain)
3  * Copyright (C) 2015 René Kijewski <rene.kijewski@fu-berlin.de>
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a copy
6  * of this software and associated documentation files (the "Software"), to deal
7  * in the Software without restriction, including without limitation the rights
8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9  * copies of the Software, and to permit persons to whom the Software is
10  * furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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21  * THE SOFTWARE.
22  */
23 
34 #ifndef CRYPTO_CHACHA_H
35 #define CRYPTO_CHACHA_H
36 
37 #include <stdint.h>
38 #include <stddef.h>
39 
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43 
48 typedef struct {
49  uint32_t state[16];
50  uint8_t rounds;
51 } chacha_ctx;
52 
65 int chacha_init(chacha_ctx *ctx,
66  unsigned rounds,
67  const uint8_t *key, uint32_t keylen,
68  const uint8_t nonce[8]);
69 
82 void chacha_keystream_bytes(chacha_ctx *ctx, void *x);
83 
97 void chacha_encrypt_bytes(chacha_ctx *ctx, const uint8_t *m, uint8_t *c);
98 
102 static inline void chacha_decrypt_bytes(chacha_ctx *ctx, const uint8_t *m,
103  uint8_t *c)
104 {
105  chacha_encrypt_bytes(ctx, m, c);
106 }
107 
126 void chacha_prng_seed(const void *data, size_t bytes);
127 
136 uint32_t chacha_prng_next(void);
137 
138 #ifdef __cplusplus
139 }
140 #endif
141 
142 #endif /* CRYPTO_CHACHA_H */
143 
chacha_encrypt_bytes
void chacha_encrypt_bytes(chacha_ctx *ctx, const uint8_t *m, uint8_t *c)
Encode or decode a block of data.
chacha_decrypt_bytes
static void chacha_decrypt_bytes(chacha_ctx *ctx, const uint8_t *m, uint8_t *c)
Encode or decode a block of data.
Definition: chacha.h:102
chacha_init
int chacha_init(chacha_ctx *ctx, unsigned rounds, const uint8_t *key, uint32_t keylen, const uint8_t nonce[8])
Initialize a ChaCha context.
chacha_ctx::rounds
uint8_t rounds
Number of iterations.
Definition: chacha.h:50
chacha_prng_seed
void chacha_prng_seed(const void *data, size_t bytes)
Seed the pseudo-random number generator.
chacha_ctx
A ChaCha cipher stream context.
Definition: chacha.h:48
chacha_prng_next
uint32_t chacha_prng_next(void)
Extract a number from the pseudo-random number generator.
chacha_keystream_bytes
void chacha_keystream_bytes(chacha_ctx *ctx, void *x)
Generate next block in the keystream.