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142 lines
2.5 KiB
C
142 lines
2.5 KiB
C
/* $OpenLDAP$ */
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/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
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*
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* Copyright 2000-2014 The OpenLDAP Foundation.
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* Portions Copyright 2000-2003 Kurt D. Zeilenga.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted only as authorized by the OpenLDAP
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* Public License.
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*
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* A copy of this license is available in the file LICENSE in the
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* top-level directory of the distribution or, alternatively, at
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* <http://www.OpenLDAP.org/license.html>.
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*/
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/* This implements the Fowler / Noll / Vo (FNV-1) hash algorithm.
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* A summary of the algorithm can be found at:
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* http://www.isthe.com/chongo/tech/comp/fnv/index.html
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*/
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#include "portable.h"
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#include <lutil_hash.h>
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/* offset and prime for 32-bit FNV-1 */
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#define HASH_OFFSET 0x811c9dc5U
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#define HASH_PRIME 16777619
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/*
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* Initialize context
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*/
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void
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lutil_HASHInit( lutil_HASH_CTX *ctx )
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{
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ctx->hash = HASH_OFFSET;
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}
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/*
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* Update hash
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*/
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void
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lutil_HASHUpdate(
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lutil_HASH_CTX *ctx,
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const unsigned char *buf,
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ber_len_t len )
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{
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const unsigned char *p, *e;
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ber_uint_t h;
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p = buf;
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e = &buf[len];
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h = ctx->hash;
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while( p < e ) {
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h *= HASH_PRIME;
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h ^= *p++;
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}
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ctx->hash = h;
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}
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/*
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* Save hash
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*/
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void
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lutil_HASHFinal( unsigned char *digest, lutil_HASH_CTX *ctx )
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{
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ber_uint_t h = ctx->hash;
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digest[0] = h & 0xffU;
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digest[1] = (h>>8) & 0xffU;
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digest[2] = (h>>16) & 0xffU;
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digest[3] = (h>>24) & 0xffU;
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}
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#ifdef HAVE_LONG_LONG
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/* 64 bit Fowler/Noll/Vo-O FNV-1a hash code */
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#define HASH64_OFFSET 0xcbf29ce484222325ULL
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/*
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* Initialize context
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*/
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void
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lutil_HASH64Init( lutil_HASH_CTX *ctx )
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{
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ctx->hash64 = HASH64_OFFSET;
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}
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/*
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* Update hash
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*/
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void
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lutil_HASH64Update(
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lutil_HASH_CTX *ctx,
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const unsigned char *buf,
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ber_len_t len )
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{
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const unsigned char *p, *e;
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unsigned long long h;
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p = buf;
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e = &buf[len];
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h = ctx->hash64;
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while( p < e ) {
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/* xor the bottom with the current octet */
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h ^= *p++;
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/* multiply by the 64 bit FNV magic prime mod 2^64 */
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h += (h << 1) + (h << 4) + (h << 5) +
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(h << 7) + (h << 8) + (h << 40);
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}
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ctx->hash64 = h;
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}
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/*
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* Save hash
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*/
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void
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lutil_HASH64Final( unsigned char *digest, lutil_HASH_CTX *ctx )
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{
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unsigned long long h = ctx->hash;
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digest[0] = h & 0xffU;
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digest[1] = (h>>8) & 0xffU;
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digest[2] = (h>>16) & 0xffU;
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digest[3] = (h>>24) & 0xffU;
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digest[4] = (h>>32) & 0xffU;
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digest[5] = (h>>40) & 0xffU;
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digest[6] = (h>>48) & 0xffU;
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digest[7] = (h>>56) & 0xffU;
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}
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#endif /* HAVE_LONG_LONG */
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