1/* $NetBSD$ */ 2 3/* OpenLDAP: pkg/ldap/libraries/liblutil/hash.c,v 1.8.2.5 2010/04/13 20:23:06 kurt Exp */ 4/* This work is part of OpenLDAP Software <http://www.openldap.org/>. 5 * 6 * Copyright 2000-2010 The OpenLDAP Foundation. 7 * Portions Copyright 2000-2003 Kurt D. Zeilenga. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted only as authorized by the OpenLDAP 12 * Public License. 13 * 14 * A copy of this license is available in the file LICENSE in the 15 * top-level directory of the distribution or, alternatively, at 16 * <http://www.OpenLDAP.org/license.html>. 17 */ 18 19/* This implements the Fowler / Noll / Vo (FNV-1) hash algorithm. 20 * A summary of the algorithm can be found at: 21 * http://www.isthe.com/chongo/tech/comp/fnv/index.html 22 */ 23 24#include "portable.h" 25 26#include <lutil_hash.h> 27 28/* offset and prime for 32-bit FNV-1 */ 29#define HASH_OFFSET 0x811c9dc5U 30#define HASH_PRIME 16777619 31 32 33/* 34 * Initialize context 35 */ 36void 37lutil_HASHInit( struct lutil_HASHContext *ctx ) 38{ 39 ctx->hash = HASH_OFFSET; 40} 41 42/* 43 * Update hash 44 */ 45void 46lutil_HASHUpdate( 47 struct lutil_HASHContext *ctx, 48 const unsigned char *buf, 49 ber_len_t len ) 50{ 51 const unsigned char *p, *e; 52 ber_uint_t h; 53 54 p = buf; 55 e = &buf[len]; 56 57 h = ctx->hash; 58 59 while( p < e ) { 60 h *= HASH_PRIME; 61 h ^= *p++; 62 } 63 64 ctx->hash = h; 65} 66 67/* 68 * Save hash 69 */ 70void 71lutil_HASHFinal( unsigned char *digest, struct lutil_HASHContext *ctx ) 72{ 73 ber_uint_t h = ctx->hash; 74 75 digest[0] = h & 0xffU; 76 digest[1] = (h>>8) & 0xffU; 77 digest[2] = (h>>16) & 0xffU; 78 digest[3] = (h>>24) & 0xffU; 79} 80