--- /dev/null
+// 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 <andre@FreeBSD.org>
+ * 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)
+{
+ while (rounds--) {
+ ctx->v[0] += ctx->v[1];
+ ctx->v[2] += ctx->v[3];
+ ctx->v[1] = rol64(ctx->v[1], 13);
+ ctx->v[3] = rol64(ctx->v[3], 16);
+
+ ctx->v[1] ^= ctx->v[0];
+ ctx->v[3] ^= ctx->v[2];
+ ctx->v[0] = rol64(ctx->v[0], 32);
+
+ ctx->v[2] += ctx->v[1];
+ ctx->v[0] += ctx->v[3];
+ ctx->v[1] = rol64(ctx->v[1], 17);
+ ctx->v[3] = rol64(ctx->v[3], 21);
+
+ ctx->v[1] ^= ctx->v[2];
+ ctx->v[3] ^= ctx->v[0];
+ ctx->v[2] = rol64(ctx->v[2], 32);
+ }
+}
+
+static void SipHash_CRounds(SIPHASH_CTX *ctx, const void *ptr, int rounds)
+{
+ u64 m = get_unaligned_le64(ptr);
+
+ ctx->v[3] ^= m;
+ SipHash_Rounds(ctx, rounds);
+ ctx->v[0] ^= m;
+}
+
+void SipHash_Init(SIPHASH_CTX *ctx, const SIPHASH_KEY *key)
+{
+ u64 k0, k1;
+
+ k0 = le64_to_cpu(key->k0);
+ k1 = le64_to_cpu(key->k1);
+
+ ctx->v[0] = 0x736f6d6570736575ULL ^ k0;
+ ctx->v[1] = 0x646f72616e646f6dULL ^ k1;
+ ctx->v[2] = 0x6c7967656e657261ULL ^ k0;
+ ctx->v[3] = 0x7465646279746573ULL ^ k1;
+
+ memset(ctx->buf, 0, sizeof(ctx->buf));
+ ctx->bytes = 0;
+}
+
+void SipHash_Update(SIPHASH_CTX *ctx, int rc, int rf,
+ const void *src, size_t len)
+{
+ const u8 *ptr = src;
+ size_t left, used;
+
+ if (len == 0)
+ return;
+
+ used = ctx->bytes % sizeof(ctx->buf);
+ ctx->bytes += len;
+
+ if (used > 0) {
+ left = sizeof(ctx->buf) - used;
+
+ if (len >= left) {
+ memcpy(&ctx->buf[used], ptr, left);
+ SipHash_CRounds(ctx, ctx->buf, rc);
+ len -= left;
+ ptr += left;
+ } else {
+ memcpy(&ctx->buf[used], ptr, len);
+ return;
+ }
+ }
+
+ while (len >= sizeof(ctx->buf)) {
+ SipHash_CRounds(ctx, ptr, rc);
+ len -= sizeof(ctx->buf);
+ ptr += sizeof(ctx->buf);
+ }
+
+ if (len > 0)
+ memcpy(&ctx->buf[used], ptr, len);
+}
+
+void SipHash_Final(void *dst, SIPHASH_CTX *ctx, int rc, int rf)
+{
+ u64 r;
+
+ r = SipHash_End(ctx, rc, rf);
+
+ *((__le64 *) dst) = cpu_to_le64(r);
+}
+
+u64 SipHash_End(SIPHASH_CTX *ctx, int rc, int rf)
+{
+ u64 r;
+ size_t left, used;
+
+ used = ctx->bytes % sizeof(ctx->buf);
+ left = sizeof(ctx->buf) - used;
+ memset(&ctx->buf[used], 0, left - 1);
+ ctx->buf[7] = ctx->bytes;
+
+ SipHash_CRounds(ctx, ctx->buf, rc);
+ ctx->v[2] ^= 0xff;
+ SipHash_Rounds(ctx, rf);
+
+ r = (ctx->v[0] ^ ctx->v[1]) ^ (ctx->v[2] ^ ctx->v[3]);
+ memset(ctx, 0, sizeof(*ctx));
+ return r;
+}
+
+u64 SipHash(const SIPHASH_KEY *key, int rc, int rf, const void *src, size_t len)
+{
+ SIPHASH_CTX ctx;
+
+ SipHash_Init(&ctx, key);
+ SipHash_Update(&ctx, rc, rf, src, len);
+ return SipHash_End(&ctx, rc, rf);
+}
projects / bcachefs-tools-debian / blobdiff