linux/include/crypto/chacha20.h
Eric Biggers 9f480faec5 crypto: chacha20 - Fix keystream alignment for chacha20_block()
When chacha20_block() outputs the keystream block, it uses 'u32' stores
directly.  However, the callers (crypto/chacha20_generic.c and
drivers/char/random.c) declare the keystream buffer as a 'u8' array,
which is not guaranteed to have the needed alignment.

Fix it by having both callers declare the keystream as a 'u32' array.
For now this is preferable to switching over to the unaligned access
macros because chacha20_block() is only being used in cases where we can
easily control the alignment (stack buffers).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-11-29 17:33:33 +11:00

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C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Common values for the ChaCha20 algorithm
*/
#ifndef _CRYPTO_CHACHA20_H
#define _CRYPTO_CHACHA20_H
#include <crypto/skcipher.h>
#include <linux/types.h>
#include <linux/crypto.h>
#define CHACHA20_IV_SIZE 16
#define CHACHA20_KEY_SIZE 32
#define CHACHA20_BLOCK_SIZE 64
#define CHACHA20_BLOCK_WORDS (CHACHA20_BLOCK_SIZE / sizeof(u32))
struct chacha20_ctx {
u32 key[8];
};
void chacha20_block(u32 *state, u32 *stream);
void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv);
int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
unsigned int keysize);
int crypto_chacha20_crypt(struct skcipher_request *req);
#endif