mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 10:01:43 +00:00
860ab2e502
Constify the ctx and iv arguments to crypto_chacha_init() and the various chacha*_stream_xor() functions. This makes it clear that they are not modified. Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
55 lines
1.7 KiB
C
55 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Common values and helper functions for the ChaCha and XChaCha stream ciphers.
|
|
*
|
|
* XChaCha extends ChaCha's nonce to 192 bits, while provably retaining ChaCha's
|
|
* security. Here they share the same key size, tfm context, and setkey
|
|
* function; only their IV size and encrypt/decrypt function differ.
|
|
*
|
|
* The ChaCha paper specifies 20, 12, and 8-round variants. In general, it is
|
|
* recommended to use the 20-round variant ChaCha20. However, the other
|
|
* variants can be needed in some performance-sensitive scenarios. The generic
|
|
* ChaCha code currently allows only the 20 and 12-round variants.
|
|
*/
|
|
|
|
#ifndef _CRYPTO_CHACHA_H
|
|
#define _CRYPTO_CHACHA_H
|
|
|
|
#include <crypto/skcipher.h>
|
|
#include <linux/types.h>
|
|
#include <linux/crypto.h>
|
|
|
|
/* 32-bit stream position, then 96-bit nonce (RFC7539 convention) */
|
|
#define CHACHA_IV_SIZE 16
|
|
|
|
#define CHACHA_KEY_SIZE 32
|
|
#define CHACHA_BLOCK_SIZE 64
|
|
#define CHACHAPOLY_IV_SIZE 12
|
|
|
|
/* 192-bit nonce, then 64-bit stream position */
|
|
#define XCHACHA_IV_SIZE 32
|
|
|
|
struct chacha_ctx {
|
|
u32 key[8];
|
|
int nrounds;
|
|
};
|
|
|
|
void chacha_block(u32 *state, u8 *stream, int nrounds);
|
|
static inline void chacha20_block(u32 *state, u8 *stream)
|
|
{
|
|
chacha_block(state, stream, 20);
|
|
}
|
|
void hchacha_block(const u32 *in, u32 *out, int nrounds);
|
|
|
|
void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv);
|
|
|
|
int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
|
|
unsigned int keysize);
|
|
int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
|
|
unsigned int keysize);
|
|
|
|
int crypto_chacha_crypt(struct skcipher_request *req);
|
|
int crypto_xchacha_crypt(struct skcipher_request *req);
|
|
|
|
#endif /* _CRYPTO_CHACHA_H */
|