1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * NH hash function for Adiantum 4 */ 5 6 #ifndef _CRYPTO_NH_H 7 #define _CRYPTO_NH_H 8 9 #include <linux/types.h> 10 11 /* NH parameterization: */ 12 13 /* Endianness: little */ 14 /* Word size: 32 bits (works well on NEON, SSE2, AVX2) */ 15 16 /* Stride: 2 words (optimal on ARM32 NEON; works okay on other CPUs too) */ 17 #define NH_PAIR_STRIDE 2 18 #define NH_MESSAGE_UNIT (NH_PAIR_STRIDE * 2 * sizeof(u32)) 19 20 /* Num passes (Toeplitz iteration count): 4, to give ε = 2^{-128} */ 21 #define NH_NUM_PASSES 4 22 #define NH_HASH_BYTES (NH_NUM_PASSES * sizeof(u64)) 23 24 /* Max message size: 1024 bytes (32x compression factor) */ 25 #define NH_NUM_STRIDES 64 26 #define NH_MESSAGE_WORDS (NH_PAIR_STRIDE * 2 * NH_NUM_STRIDES) 27 #define NH_MESSAGE_BYTES (NH_MESSAGE_WORDS * sizeof(u32)) 28 #define NH_KEY_WORDS (NH_MESSAGE_WORDS + \ 29 NH_PAIR_STRIDE * 2 * (NH_NUM_PASSES - 1)) 30 #define NH_KEY_BYTES (NH_KEY_WORDS * sizeof(u32)) 31 32 /** 33 * nh() - NH hash function for Adiantum 34 * @key: The key. @message_len + 48 bytes of it are used. This is NH_KEY_BYTES 35 * if @message_len has its maximum length of NH_MESSAGE_BYTES. 36 * @message: The message 37 * @message_len: The message length in bytes. Must be a multiple of 16 38 * (NH_MESSAGE_UNIT) and at most 1024 (NH_MESSAGE_BYTES). 39 * @hash: (output) The resulting hash value 40 * 41 * Note: the pseudocode for NH in the Adiantum paper iterates over 1024-byte 42 * segments of the message, computes a 32-byte hash for each, and returns all 43 * the hashes concatenated together. In contrast, this function just hashes one 44 * segment and returns one hash. It's the caller's responsibility to call this 45 * function for each 1024-byte segment and collect all the hashes. 46 * 47 * Context: Any context. 48 */ 49 void nh(const u32 *key, const u8 *message, size_t message_len, 50 __le64 hash[NH_NUM_PASSES]); 51 52 #endif /* _CRYPTO_NH_H */ 53