5fb8ef2580
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API, let's expose the streamcipher bits via a library API as well, in a way that permits the implementation to be superseded by an architecture specific one if provided.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 <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _CRYPTO_INTERNAL_CHACHA_H
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#define _CRYPTO_INTERNAL_CHACHA_H
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#include <crypto/chacha.h>
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#include <crypto/internal/skcipher.h>
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#include <linux/crypto.h>
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struct chacha_ctx {
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u32 key[8];
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int nrounds;
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};
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void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv);
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static inline int chacha_setkey(struct crypto_skcipher *tfm, const u8 *key,
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unsigned int keysize, int nrounds)
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{
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struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
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int i;
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if (keysize != CHACHA_KEY_SIZE)
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return -EINVAL;
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for (i = 0; i < ARRAY_SIZE(ctx->key); i++)
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ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32));
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ctx->nrounds = nrounds;
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return 0;
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}
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static inline int chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
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unsigned int keysize)
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{
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return chacha_setkey(tfm, key, keysize, 20);
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}
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static int inline chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
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unsigned int keysize)
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{
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return chacha_setkey(tfm, key, keysize, 12);
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}
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int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
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unsigned int keysize);
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int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
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unsigned int keysize);
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int crypto_chacha_crypt(struct skcipher_request *req);
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int crypto_xchacha_crypt(struct skcipher_request *req);
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#endif /* _CRYPTO_CHACHA_H */
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