xref: /linux/include/crypto/internal/chacha.h (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef _CRYPTO_INTERNAL_CHACHA_H
4 #define _CRYPTO_INTERNAL_CHACHA_H
5 
6 #include <crypto/chacha.h>
7 #include <crypto/internal/skcipher.h>
8 #include <linux/crypto.h>
9 
10 struct chacha_ctx {
11 	u32 key[8];
12 	int nrounds;
13 };
14 
15 static inline int chacha_setkey(struct crypto_skcipher *tfm, const u8 *key,
16 				unsigned int keysize, int nrounds)
17 {
18 	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
19 	int i;
20 
21 	if (keysize != CHACHA_KEY_SIZE)
22 		return -EINVAL;
23 
24 	for (i = 0; i < ARRAY_SIZE(ctx->key); i++)
25 		ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32));
26 
27 	ctx->nrounds = nrounds;
28 	return 0;
29 }
30 
31 static inline int chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
32 				  unsigned int keysize)
33 {
34 	return chacha_setkey(tfm, key, keysize, 20);
35 }
36 
37 static inline int chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
38 				  unsigned int keysize)
39 {
40 	return chacha_setkey(tfm, key, keysize, 12);
41 }
42 
43 #endif /* _CRYPTO_CHACHA_H */
44