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author | Eric Biggers <ebiggers@google.com> | 2018-11-16 17:26:29 -0800 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-11-20 14:26:56 +0800 |
commit | 26609a21a9460145e37d90947ad957b358a05288 (patch) | |
tree | 9f45456ea58fde4464ea71910acf0faf55214555 /include/crypto | |
parent | 1b6fd3d5d18bbc1b1abf3b0cbc4b95a9a63d407b (diff) | |
download | linux-26609a21a9460145e37d90947ad957b358a05288.tar.bz2 |
crypto: nhpoly1305 - add NHPoly1305 support
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>
Diffstat (limited to 'include/crypto')
-rw-r--r-- | include/crypto/nhpoly1305.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/include/crypto/nhpoly1305.h b/include/crypto/nhpoly1305.h new file mode 100644 index 000000000000..53c04423c582 --- /dev/null +++ b/include/crypto/nhpoly1305.h @@ -0,0 +1,74 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common values and helper functions for the NHPoly1305 hash function. + */ + +#ifndef _NHPOLY1305_H +#define _NHPOLY1305_H + +#include <crypto/hash.h> +#include <crypto/poly1305.h> + +/* NH parameterization: */ + +/* Endianness: little */ +/* Word size: 32 bits (works well on NEON, SSE2, AVX2) */ + +/* Stride: 2 words (optimal on ARM32 NEON; works okay on other CPUs too) */ +#define NH_PAIR_STRIDE 2 +#define NH_MESSAGE_UNIT (NH_PAIR_STRIDE * 2 * sizeof(u32)) + +/* Num passes (Toeplitz iteration count): 4, to give ε = 2^{-128} */ +#define NH_NUM_PASSES 4 +#define NH_HASH_BYTES (NH_NUM_PASSES * sizeof(u64)) + +/* Max message size: 1024 bytes (32x compression factor) */ +#define NH_NUM_STRIDES 64 +#define NH_MESSAGE_WORDS (NH_PAIR_STRIDE * 2 * NH_NUM_STRIDES) +#define NH_MESSAGE_BYTES (NH_MESSAGE_WORDS * sizeof(u32)) +#define NH_KEY_WORDS (NH_MESSAGE_WORDS + \ + NH_PAIR_STRIDE * 2 * (NH_NUM_PASSES - 1)) +#define NH_KEY_BYTES (NH_KEY_WORDS * sizeof(u32)) + +#define NHPOLY1305_KEY_SIZE (POLY1305_BLOCK_SIZE + NH_KEY_BYTES) + +struct nhpoly1305_key { + struct poly1305_key poly_key; + u32 nh_key[NH_KEY_WORDS]; +}; + +struct nhpoly1305_state { + + /* Running total of polynomial evaluation */ + struct poly1305_state poly_state; + + /* Partial block buffer */ + u8 buffer[NH_MESSAGE_UNIT]; + unsigned int buflen; + + /* + * Number of bytes remaining until the current NH message reaches + * NH_MESSAGE_BYTES. When nonzero, 'nh_hash' holds the partial NH hash. + */ + unsigned int nh_remaining; + + __le64 nh_hash[NH_NUM_PASSES]; +}; + +typedef void (*nh_t)(const u32 *key, const u8 *message, size_t message_len, + __le64 hash[NH_NUM_PASSES]); + +int crypto_nhpoly1305_setkey(struct crypto_shash *tfm, + const u8 *key, unsigned int keylen); + +int crypto_nhpoly1305_init(struct shash_desc *desc); +int crypto_nhpoly1305_update(struct shash_desc *desc, + const u8 *src, unsigned int srclen); +int crypto_nhpoly1305_update_helper(struct shash_desc *desc, + const u8 *src, unsigned int srclen, + nh_t nh_fn); +int crypto_nhpoly1305_final(struct shash_desc *desc, u8 *dst); +int crypto_nhpoly1305_final_helper(struct shash_desc *desc, u8 *dst, + nh_t nh_fn); + +#endif /* _NHPOLY1305_H */ |