/* $NetBSD: siphash.c,v 1.8 2023/01/25 21:43:31 christos Exp $ */
/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#include <inttypes.h>
#include <string.h>
#include <unistd.h>
#include <isc/endian.h>
#include <isc/siphash.h>
#include <isc/util.h>
/*
* The implementation is based on SipHash reference C implementation by
*
* Copyright (c) 2012-2016 Jean-Philippe Aumasson
* <jeanphilippe.aumasson@gmail.com> Copyright (c) 2012-2014 Daniel J. Bernstein
* <djb@cr.yp.to>
*
* To the extent possible under law, the author(s) have dedicated all copyright
* and related and neighboring rights to this software to the public domain
* worldwide. This software is distributed without any warranty. You should
* have received a copy of the CC0 Public Domain Dedication along with this
* software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
#define cROUNDS 2
#define dROUNDS 4
#define ROTATE64(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
#define HALF_ROUND64(a, b, c, d, s, t) \
a += b; \
c += d; \
b = ROTATE64(b, s) ^ a; \
d = ROTATE64(d, t) ^ c; \
a = ROTATE64(a, 32);
#define FULL_ROUND64(v0, v1, v2, v3) \
HALF_ROUND64(v0, v1, v2, v3, 13, 16); \
HALF_ROUND64(v2, v1, v0, v3, 17, 21);
#define SIPROUND FULL_ROUND64
#define ROTATE32(x, b) (uint32_t)(((x) << (b)) | ((x) >> (32 - (b))))
#define HALF_ROUND32(a, b, c, d, s, t) \
a += b; \
c += d; \
b = ROTATE32(b, s) ^ a; \
d = ROTATE32(d, t) ^ c; \
a = ROTATE32(a, 16);
#define FULL_ROUND32(v0, v1, v2, v3) \
HALF_ROUND32(v0, v1, v2, v3, 5, 8); \
HALF_ROUND32(v2, v1, v0, v3, 13, 7);
#define HALFSIPROUND FULL_ROUND32
#define U32TO8_LE(p, v) \
(p)[0] = (uint8_t)((v)); \
(p)[1] = (uint8_t)((v) >> 8); \
(p)[2] = (uint8_t)((v) >> 16); \
(p)[3] = (uint8_t)((v) >> 24);
#define U8TO32_LE(p) \
(((uint32_t)((p)[0])) | ((uint32_t)((p)[1]) << 8) | \
((uint32_t)((p)[2]) << 16) | ((uint32_t)((p)[3]) << 24))
#define U64TO8_LE(p, v) \
U32TO8_LE((p), (uint32_t)((v))); \
U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
#define U8TO64_LE(p) \
(((uint64_t)((p)[0])) | ((uint64_t)((p)[1]) << 8) | \
((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) | \
((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) | \
((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56))
void
isc_siphash24(const uint8_t *k, const uint8_t *in, const size_t inlen,
uint8_t *out) {
REQUIRE(k != NULL);
REQUIRE(out != NULL);
REQUIRE(inlen == 0 || in != NULL);
uint64_t k0;
uint64_t k1;
memcpy(&k0, k, sizeof(k0));
memcpy(&k1, k + sizeof(k0), sizeof(k1));
k0 = le64toh(k0);
k1 = le64toh(k1);
uint64_t v0 = UINT64_C(0x736f6d6570736575) ^ k0;
uint64_t v1 = UINT64_C(0x646f72616e646f6d) ^ k1;
uint64_t v2 = UINT64_C(0x6c7967656e657261) ^ k0;
uint64_t v3 = UINT64_C(0x7465646279746573) ^ k1;
uint64_t b = ((uint64_t)inlen) << 56;
const uint8_t *end = (in == NULL)
? NULL
: in + inlen - (inlen % sizeof(uint64_t));
const size_t left = inlen & 7;
for (; in != end; in += 8) {
uint64_t m = U8TO64_LE(in);
v3 ^= m;
for (size_t i = 0; i < cROUNDS; ++i) {
SIPROUND(v0, v1, v2, v3);
}
v0 ^= m;
}
switch (left) {
case 7:
b |= ((uint64_t)in[6]) << 48;
FALLTHROUGH;
case 6:
b |= ((uint64_t)in[5]) << 40;
FALLTHROUGH;
case 5:
b |= ((uint64_t)in[4]) << 32;
FALLTHROUGH;
case 4:
b |= ((uint64_t)in[3]) << 24;
FALLTHROUGH;
case 3:
b |= ((uint64_t)in[2]) << 16;
FALLTHROUGH;
case 2:
b |= ((uint64_t)in[1]) << 8;
FALLTHROUGH;
case 1:
b |= ((uint64_t)in[0]);
FALLTHROUGH;
case 0:
break;
default:
UNREACHABLE();
}
v3 ^= b;
for (size_t i = 0; i < cROUNDS; ++i) {
SIPROUND(v0, v1, v2, v3);
}
v0 ^= b;
v2 ^= 0xff;
for (size_t i = 0; i < dROUNDS; ++i) {
SIPROUND(v0, v1, v2, v3);
}
b = v0 ^ v1 ^ v2 ^ v3;
U64TO8_LE(out, b);
}
void
isc_halfsiphash24(const uint8_t *k, const uint8_t *in, const size_t inlen,
uint8_t *out) {
REQUIRE(k != NULL);
REQUIRE(out != NULL);
REQUIRE(inlen == 0 || in != NULL);
uint32_t k0 = U8TO32_LE(k);
uint32_t k1 = U8TO32_LE(k + 4);
uint32_t v0 = UINT32_C(0x00000000) ^ k0;
uint32_t v1 = UINT32_C(0x00000000) ^ k1;
uint32_t v2 = UINT32_C(0x6c796765) ^ k0;
uint32_t v3 = UINT32_C(0x74656462) ^ k1;
uint32_t b = ((uint32_t)inlen) << 24;
const uint8_t *end = (in == NULL)
? NULL
: in + inlen - (inlen % sizeof(uint32_t));
const int left = inlen & 3;
for (; in != end; in += 4) {
uint32_t m = U8TO32_LE(in);
v3 ^= m;
for (size_t i = 0; i < cROUNDS; ++i) {
HALFSIPROUND(v0, v1, v2, v3);
}
v0 ^= m;
}
switch (left) {
case 3:
b |= ((uint32_t)in[2]) << 16;
FALLTHROUGH;
case 2:
b |= ((uint32_t)in[1]) << 8;
FALLTHROUGH;
case 1:
b |= ((uint32_t)in[0]);
FALLTHROUGH;
case 0:
break;
default:
UNREACHABLE();
}
v3 ^= b;
for (size_t i = 0; i < cROUNDS; ++i) {
HALFSIPROUND(v0, v1, v2, v3);
}
v0 ^= b;
v2 ^= 0xff;
for (size_t i = 0; i < dROUNDS; ++i) {
HALFSIPROUND(v0, v1, v2, v3);
}
b = v1 ^ v3;
U32TO8_LE(out, b);
}