linux/fs/bcachefs/siphash.c

// SPDX-License-Identifier: BSD-3-Clause
/*	$OpenBSD: siphash.c,v 1.3 2015/02/20 11:51:03 tedu Exp $ */

/*-
 * Copyright (c) 2013 Andre Oppermann <[email protected]>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * SipHash is a family of PRFs SipHash-c-d where the integer parameters c and d
 * are the number of compression rounds and the number of finalization rounds.
 * A compression round is identical to a finalization round and this round
 * function is called SipRound.  Given a 128-bit key k and a (possibly empty)
 * byte string m, SipHash-c-d returns a 64-bit value SipHash-c-d(k; m).
 *
 * Implemented from the paper "SipHash: a fast short-input PRF", 2012.09.18,
 * by Jean-Philippe Aumasson and Daniel J. Bernstein,
 * Permanent Document ID b9a943a805fbfc6fde808af9fc0ecdfa
 * https://131002.net/siphash/siphash.pdf
 * https://131002.net/siphash/
 */

#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <linux/bitops.h>
#include <linux/string.h>

#include "siphash.h"

static void SipHash_Rounds(SIPHASH_CTX *ctx, int rounds)
{ … }

static void SipHash_CRounds(SIPHASH_CTX *ctx, const void *ptr, int rounds)
{ … }

void SipHash_Init(SIPHASH_CTX *ctx, const SIPHASH_KEY *key)
{ … }

void SipHash_Update(SIPHASH_CTX *ctx, int rc, int rf,
		    const void *src, size_t len)
{ … }

void SipHash_Final(void *dst, SIPHASH_CTX *ctx, int rc, int rf)
{ … }

u64 SipHash_End(SIPHASH_CTX *ctx, int rc, int rf)
{ … }

u64 SipHash(const SIPHASH_KEY *key, int rc, int rf, const void *src, size_t len)
{ … }