From 5fb8ef25803ef33e2eb60b626435828b937bed75 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 8 Nov 2019 13:22:08 +0100 Subject: crypto: chacha - move existing library code into lib/crypto Currently, our generic ChaCha implementation consists of a permute function in lib/chacha.c that operates on the 64-byte ChaCha state directly [and which is always included into the core kernel since it is used by the /dev/random driver], and the crypto API plumbing to expose it as a skcipher. In order to support in-kernel users that need the ChaCha streamcipher but have no need [or tolerance] for going through the abstractions of the crypto API, let's expose the streamcipher bits via a library API as well, in a way that permits the implementation to be superseded by an architecture specific one if provided. So move the streamcipher code into a separate module in lib/crypto, and expose the init() and crypt() routines to users of the library. Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- include/crypto/internal/chacha.h | 53 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 include/crypto/internal/chacha.h (limited to 'include/crypto/internal/chacha.h') diff --git a/include/crypto/internal/chacha.h b/include/crypto/internal/chacha.h new file mode 100644 index 000000000000..c0e40b245431 --- /dev/null +++ b/include/crypto/internal/chacha.h @@ -0,0 +1,53 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _CRYPTO_INTERNAL_CHACHA_H +#define _CRYPTO_INTERNAL_CHACHA_H + +#include +#include +#include + +struct chacha_ctx { + u32 key[8]; + int nrounds; +}; + +void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv); + +static inline int chacha_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keysize, int nrounds) +{ + struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm); + int i; + + if (keysize != CHACHA_KEY_SIZE) + return -EINVAL; + + for (i = 0; i < ARRAY_SIZE(ctx->key); i++) + ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32)); + + ctx->nrounds = nrounds; + return 0; +} + +static inline int chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keysize) +{ + return chacha_setkey(tfm, key, keysize, 20); +} + +static int inline chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key, + unsigned int keysize) +{ + return chacha_setkey(tfm, key, keysize, 12); +} + +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 */ -- cgit