xref: /linux/include/crypto/nhpoly1305.h (revision 8dd06ef34b6e2f41b29fbf5fc1663780f2524285)
126609a21SEric Biggers /* SPDX-License-Identifier: GPL-2.0 */
226609a21SEric Biggers /*
326609a21SEric Biggers  * Common values and helper functions for the NHPoly1305 hash function.
426609a21SEric Biggers  */
526609a21SEric Biggers 
626609a21SEric Biggers #ifndef _NHPOLY1305_H
726609a21SEric Biggers #define _NHPOLY1305_H
826609a21SEric Biggers 
926609a21SEric Biggers #include <crypto/hash.h>
10*1c08a104SJason A. Donenfeld #include <crypto/internal/poly1305.h>
1126609a21SEric Biggers 
1226609a21SEric Biggers /* NH parameterization: */
1326609a21SEric Biggers 
1426609a21SEric Biggers /* Endianness: little */
1526609a21SEric Biggers /* Word size: 32 bits (works well on NEON, SSE2, AVX2) */
1626609a21SEric Biggers 
1726609a21SEric Biggers /* Stride: 2 words (optimal on ARM32 NEON; works okay on other CPUs too) */
1826609a21SEric Biggers #define NH_PAIR_STRIDE		2
1926609a21SEric Biggers #define NH_MESSAGE_UNIT		(NH_PAIR_STRIDE * 2 * sizeof(u32))
2026609a21SEric Biggers 
2126609a21SEric Biggers /* Num passes (Toeplitz iteration count): 4, to give ε = 2^{-128} */
2226609a21SEric Biggers #define NH_NUM_PASSES		4
2326609a21SEric Biggers #define NH_HASH_BYTES		(NH_NUM_PASSES * sizeof(u64))
2426609a21SEric Biggers 
2526609a21SEric Biggers /* Max message size: 1024 bytes (32x compression factor) */
2626609a21SEric Biggers #define NH_NUM_STRIDES		64
2726609a21SEric Biggers #define NH_MESSAGE_WORDS	(NH_PAIR_STRIDE * 2 * NH_NUM_STRIDES)
2826609a21SEric Biggers #define NH_MESSAGE_BYTES	(NH_MESSAGE_WORDS * sizeof(u32))
2926609a21SEric Biggers #define NH_KEY_WORDS		(NH_MESSAGE_WORDS + \
3026609a21SEric Biggers 				 NH_PAIR_STRIDE * 2 * (NH_NUM_PASSES - 1))
3126609a21SEric Biggers #define NH_KEY_BYTES		(NH_KEY_WORDS * sizeof(u32))
3226609a21SEric Biggers 
3326609a21SEric Biggers #define NHPOLY1305_KEY_SIZE	(POLY1305_BLOCK_SIZE + NH_KEY_BYTES)
3426609a21SEric Biggers 
3526609a21SEric Biggers struct nhpoly1305_key {
36*1c08a104SJason A. Donenfeld 	struct poly1305_core_key poly_key;
3726609a21SEric Biggers 	u32 nh_key[NH_KEY_WORDS];
3826609a21SEric Biggers };
3926609a21SEric Biggers 
4026609a21SEric Biggers struct nhpoly1305_state {
4126609a21SEric Biggers 
4226609a21SEric Biggers 	/* Running total of polynomial evaluation */
4326609a21SEric Biggers 	struct poly1305_state poly_state;
4426609a21SEric Biggers 
4526609a21SEric Biggers 	/* Partial block buffer */
4626609a21SEric Biggers 	u8 buffer[NH_MESSAGE_UNIT];
4726609a21SEric Biggers 	unsigned int buflen;
4826609a21SEric Biggers 
4926609a21SEric Biggers 	/*
5026609a21SEric Biggers 	 * Number of bytes remaining until the current NH message reaches
5126609a21SEric Biggers 	 * NH_MESSAGE_BYTES.  When nonzero, 'nh_hash' holds the partial NH hash.
5226609a21SEric Biggers 	 */
5326609a21SEric Biggers 	unsigned int nh_remaining;
5426609a21SEric Biggers 
5526609a21SEric Biggers 	__le64 nh_hash[NH_NUM_PASSES];
5626609a21SEric Biggers };
5726609a21SEric Biggers 
5826609a21SEric Biggers typedef void (*nh_t)(const u32 *key, const u8 *message, size_t message_len,
5926609a21SEric Biggers 		     __le64 hash[NH_NUM_PASSES]);
6026609a21SEric Biggers 
6126609a21SEric Biggers int crypto_nhpoly1305_setkey(struct crypto_shash *tfm,
6226609a21SEric Biggers 			     const u8 *key, unsigned int keylen);
6326609a21SEric Biggers 
6426609a21SEric Biggers int crypto_nhpoly1305_init(struct shash_desc *desc);
6526609a21SEric Biggers int crypto_nhpoly1305_update(struct shash_desc *desc,
6626609a21SEric Biggers 			     const u8 *src, unsigned int srclen);
6726609a21SEric Biggers int crypto_nhpoly1305_update_helper(struct shash_desc *desc,
6826609a21SEric Biggers 				    const u8 *src, unsigned int srclen,
6926609a21SEric Biggers 				    nh_t nh_fn);
7026609a21SEric Biggers int crypto_nhpoly1305_final(struct shash_desc *desc, u8 *dst);
7126609a21SEric Biggers int crypto_nhpoly1305_final_helper(struct shash_desc *desc, u8 *dst,
7226609a21SEric Biggers 				   nh_t nh_fn);
7326609a21SEric Biggers 
7426609a21SEric Biggers #endif /* _NHPOLY1305_H */
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