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26609a21a9
Add a generic implementation of NHPoly1305, an ε-almost-∆-universal hash function used in the Adiantum encryption mode. CONFIG_NHPOLY1305 is not selectable by itself since there won't be any real reason to enable it without also enabling Adiantum support. 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>
75 lines
2.2 KiB
C
75 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Common values and helper functions for the NHPoly1305 hash function.
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*/
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#ifndef _NHPOLY1305_H
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#define _NHPOLY1305_H
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#include <crypto/hash.h>
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#include <crypto/poly1305.h>
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/* NH parameterization: */
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/* Endianness: little */
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/* Word size: 32 bits (works well on NEON, SSE2, AVX2) */
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/* Stride: 2 words (optimal on ARM32 NEON; works okay on other CPUs too) */
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#define NH_PAIR_STRIDE 2
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#define NH_MESSAGE_UNIT (NH_PAIR_STRIDE * 2 * sizeof(u32))
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/* Num passes (Toeplitz iteration count): 4, to give ε = 2^{-128} */
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#define NH_NUM_PASSES 4
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#define NH_HASH_BYTES (NH_NUM_PASSES * sizeof(u64))
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/* Max message size: 1024 bytes (32x compression factor) */
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#define NH_NUM_STRIDES 64
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#define NH_MESSAGE_WORDS (NH_PAIR_STRIDE * 2 * NH_NUM_STRIDES)
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#define NH_MESSAGE_BYTES (NH_MESSAGE_WORDS * sizeof(u32))
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#define NH_KEY_WORDS (NH_MESSAGE_WORDS + \
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NH_PAIR_STRIDE * 2 * (NH_NUM_PASSES - 1))
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#define NH_KEY_BYTES (NH_KEY_WORDS * sizeof(u32))
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#define NHPOLY1305_KEY_SIZE (POLY1305_BLOCK_SIZE + NH_KEY_BYTES)
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struct nhpoly1305_key {
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struct poly1305_key poly_key;
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u32 nh_key[NH_KEY_WORDS];
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};
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struct nhpoly1305_state {
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/* Running total of polynomial evaluation */
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struct poly1305_state poly_state;
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/* Partial block buffer */
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u8 buffer[NH_MESSAGE_UNIT];
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unsigned int buflen;
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/*
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* Number of bytes remaining until the current NH message reaches
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* NH_MESSAGE_BYTES. When nonzero, 'nh_hash' holds the partial NH hash.
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*/
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unsigned int nh_remaining;
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__le64 nh_hash[NH_NUM_PASSES];
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};
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typedef void (*nh_t)(const u32 *key, const u8 *message, size_t message_len,
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__le64 hash[NH_NUM_PASSES]);
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int crypto_nhpoly1305_setkey(struct crypto_shash *tfm,
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const u8 *key, unsigned int keylen);
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int crypto_nhpoly1305_init(struct shash_desc *desc);
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int crypto_nhpoly1305_update(struct shash_desc *desc,
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const u8 *src, unsigned int srclen);
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int crypto_nhpoly1305_update_helper(struct shash_desc *desc,
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const u8 *src, unsigned int srclen,
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nh_t nh_fn);
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int crypto_nhpoly1305_final(struct shash_desc *desc, u8 *dst);
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int crypto_nhpoly1305_final_helper(struct shash_desc *desc, u8 *dst,
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nh_t nh_fn);
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#endif /* _NHPOLY1305_H */
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