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/* SPDX-License-Identifier: GPL-2.0 */
/*
* NH hash function for Adiantum
*/
#ifndef _CRYPTO_NH_H
#define _CRYPTO_NH_H
#include <linux/types.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))
/**
* nh() - NH hash function for Adiantum
* @key: The key. @message_len + 48 bytes of it are used. This is NH_KEY_BYTES
* if @message_len has its maximum length of NH_MESSAGE_BYTES.
* @message: The message
* @message_len: The message length in bytes. Must be a multiple of 16
* (NH_MESSAGE_UNIT) and at most 1024 (NH_MESSAGE_BYTES).
* @hash: (output) The resulting hash value
*
* Note: the pseudocode for NH in the Adiantum paper iterates over 1024-byte
* segments of the message, computes a 32-byte hash for each, and returns all
* the hashes concatenated together. In contrast, this function just hashes one
* segment and returns one hash. It's the caller's responsibility to call this
* function for each 1024-byte segment and collect all the hashes.
*
* Context: Any context.
*/
void nh(const u32 *key, const u8 *message, size_t message_len,
__le64 hash[NH_NUM_PASSES]);
#endif /* _CRYPTO_NH_H */
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