83 lines
2.2 KiB
C
83 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright 2018 Google LLC
|
|
*/
|
|
|
|
/*
|
|
* Implementation of the NH almost-universal hash function, specifically the
|
|
* variant of NH used in Adiantum. This is *not* a cryptographic hash function.
|
|
*
|
|
* Reference: section 6.3 of "Adiantum: length-preserving encryption for
|
|
* entry-level processors" (https://eprint.iacr.org/2018/720.pdf).
|
|
*/
|
|
|
|
#include <crypto/nh.h>
|
|
#include <linux/export.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/unaligned.h>
|
|
|
|
#ifdef CONFIG_CRYPTO_LIB_NH_ARCH
|
|
#include "nh.h" /* $(SRCARCH)/nh.h */
|
|
#else
|
|
static bool nh_arch(const u32 *key, const u8 *message, size_t message_len,
|
|
__le64 hash[NH_NUM_PASSES])
|
|
{
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
void nh(const u32 *key, const u8 *message, size_t message_len,
|
|
__le64 hash[NH_NUM_PASSES])
|
|
{
|
|
u64 sums[4] = { 0, 0, 0, 0 };
|
|
|
|
if (nh_arch(key, message, message_len, hash))
|
|
return;
|
|
|
|
static_assert(NH_PAIR_STRIDE == 2);
|
|
static_assert(NH_NUM_PASSES == 4);
|
|
|
|
while (message_len) {
|
|
u32 m0 = get_unaligned_le32(message + 0);
|
|
u32 m1 = get_unaligned_le32(message + 4);
|
|
u32 m2 = get_unaligned_le32(message + 8);
|
|
u32 m3 = get_unaligned_le32(message + 12);
|
|
|
|
sums[0] += (u64)(u32)(m0 + key[0]) * (u32)(m2 + key[2]);
|
|
sums[1] += (u64)(u32)(m0 + key[4]) * (u32)(m2 + key[6]);
|
|
sums[2] += (u64)(u32)(m0 + key[8]) * (u32)(m2 + key[10]);
|
|
sums[3] += (u64)(u32)(m0 + key[12]) * (u32)(m2 + key[14]);
|
|
sums[0] += (u64)(u32)(m1 + key[1]) * (u32)(m3 + key[3]);
|
|
sums[1] += (u64)(u32)(m1 + key[5]) * (u32)(m3 + key[7]);
|
|
sums[2] += (u64)(u32)(m1 + key[9]) * (u32)(m3 + key[11]);
|
|
sums[3] += (u64)(u32)(m1 + key[13]) * (u32)(m3 + key[15]);
|
|
key += NH_MESSAGE_UNIT / sizeof(key[0]);
|
|
message += NH_MESSAGE_UNIT;
|
|
message_len -= NH_MESSAGE_UNIT;
|
|
}
|
|
|
|
hash[0] = cpu_to_le64(sums[0]);
|
|
hash[1] = cpu_to_le64(sums[1]);
|
|
hash[2] = cpu_to_le64(sums[2]);
|
|
hash[3] = cpu_to_le64(sums[3]);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nh);
|
|
|
|
#ifdef nh_mod_init_arch
|
|
static int __init nh_mod_init(void)
|
|
{
|
|
nh_mod_init_arch();
|
|
return 0;
|
|
}
|
|
subsys_initcall(nh_mod_init);
|
|
|
|
static void __exit nh_mod_exit(void)
|
|
{
|
|
}
|
|
module_exit(nh_mod_exit);
|
|
#endif
|
|
|
|
MODULE_DESCRIPTION("NH almost-universal hash function");
|
|
MODULE_LICENSE("GPL");
|