fs/bcachefs/siphash.h

   1 /* SPDX-License-Identifier: BSD-3-Clause */
   2 /* $OpenBSD: siphash.h,v 1.5 2015/02/20 11:51:03 tedu Exp $ */
   3 /*-
   4  * Copyright (c) 2013 Andre Oppermann <andre@FreeBSD.org>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote
  16  *    products derived from this software without specific prior written
  17  *    permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD$
  32  */
  33
  34 /*
  35  * SipHash is a family of pseudorandom functions (a.k.a. keyed hash functions)
  36  * optimized for speed on short messages returning a 64bit hash/digest value.
  37  *
  38  * The number of rounds is defined during the initialization:
  39  *  SipHash24_Init() for the fast and resonable strong version
  40  *  SipHash48_Init() for the strong version (half as fast)
  41  *
  42  * struct SIPHASH_CTX ctx;
  43  * SipHash24_Init(&ctx);
  44  * SipHash_SetKey(&ctx, "16bytes long key");
  45  * SipHash_Update(&ctx, pointer_to_string, length_of_string);
  46  * SipHash_Final(output, &ctx);
  47  */
  48
  49 #ifndef _SIPHASH_H_
  50 #define _SIPHASH_H_
  51
  52 #include <linux/types.h>
  53
  54 #define SIPHASH_BLOCK_LENGTH     8
  55 #define SIPHASH_KEY_LENGTH      16
  56 #define SIPHASH_DIGEST_LENGTH    8
  57
  58 typedef struct _SIPHASH_CTX {
  59         u64             v[4];
  60         u8              buf[SIPHASH_BLOCK_LENGTH];
  61         u32             bytes;
  62 } SIPHASH_CTX;
  63
  64 typedef struct {
  65         __le64          k0;
  66         __le64          k1;
  67 } SIPHASH_KEY;
  68
  69 void    SipHash_Init(SIPHASH_CTX *, const SIPHASH_KEY *);
  70 void    SipHash_Update(SIPHASH_CTX *, int, int, const void *, size_t);
  71 u64     SipHash_End(SIPHASH_CTX *, int, int);
  72 void    SipHash_Final(void *, SIPHASH_CTX *, int, int);
  73 u64     SipHash(const SIPHASH_KEY *, int, int, const void *, size_t);
  74
  75 #define SipHash24_Init(_c, _k)          SipHash_Init((_c), (_k))
  76 #define SipHash24_Update(_c, _p, _l)    SipHash_Update((_c), 2, 4, (_p), (_l))
  77 #define SipHash24_End(_d)               SipHash_End((_d), 2, 4)
  78 #define SipHash24_Final(_d, _c)         SipHash_Final((_d), (_c), 2, 4)
  79 #define SipHash24(_k, _p, _l)           SipHash((_k), 2, 4, (_p), (_l))
  80
  81 #define SipHash48_Init(_c, _k)          SipHash_Init((_c), (_k))
  82 #define SipHash48_Update(_c, _p, _l)    SipHash_Update((_c), 4, 8, (_p), (_l))
  83 #define SipHash48_End(_d)               SipHash_End((_d), 4, 8)
  84 #define SipHash48_Final(_d, _c)         SipHash_Final((_d), (_c), 4, 8)
  85 #define SipHash48(_k, _p, _l)           SipHash((_k), 4, 8, (_p), (_l))
  86
  87 #endif /* _SIPHASH_H_ */