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/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 2000-2024 The OpenLDAP Foundation.
* Portions Copyright 2000-2003 Kurt D. Zeilenga.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
/* This implements the Fowler / Noll / Vo (FNV-1) hash algorithm.
* A summary of the algorithm can be found at:
* http://www.isthe.com/chongo/tech/comp/fnv/index.html
*/
#include "portable.h"
#include <lutil_hash.h>
/* offset and prime for 32-bit FNV-1 */
#define HASH_OFFSET 0x811c9dc5U
#define HASH_PRIME 16777619
/*
* Initialize context
*/
void
lutil_HASHInit( lutil_HASH_CTX *ctx )
{
ctx->hash = HASH_OFFSET;
}
/*
* Update hash
*/
void
lutil_HASHUpdate(
lutil_HASH_CTX *ctx,
const unsigned char *buf,
ber_len_t len )
{
const unsigned char *p, *e;
ber_uint_t h;
p = buf;
e = &buf[len];
h = ctx->hash;
while( p < e ) {
h *= HASH_PRIME;
h ^= *p++;
}
ctx->hash = h;
}
/*
* Save hash
*/
void
lutil_HASHFinal( unsigned char *digest, lutil_HASH_CTX *ctx )
{
ber_uint_t h = ctx->hash;
digest[0] = h & 0xffU;
digest[1] = (h>>8) & 0xffU;
digest[2] = (h>>16) & 0xffU;
digest[3] = (h>>24) & 0xffU;
}
#ifdef HAVE_LONG_LONG
/* 64 bit Fowler/Noll/Vo-O FNV-1a hash code */
#define HASH64_OFFSET 0xcbf29ce484222325ULL
/*
* Initialize context
*/
void
lutil_HASH64Init( lutil_HASH_CTX *ctx )
{
ctx->hash64 = HASH64_OFFSET;
}
/*
* Update hash
*/
void
lutil_HASH64Update(
lutil_HASH_CTX *ctx,
const unsigned char *buf,
ber_len_t len )
{
const unsigned char *p, *e;
unsigned long long h;
p = buf;
e = &buf[len];
h = ctx->hash64;
while( p < e ) {
/* xor the bottom with the current octet */
h ^= *p++;
/* multiply by the 64 bit FNV magic prime mod 2^64 */
h += (h << 1) + (h << 4) + (h << 5) +
(h << 7) + (h << 8) + (h << 40);
}
ctx->hash64 = h;
}
/*
* Save hash
*/
void
lutil_HASH64Final( unsigned char *digest, lutil_HASH_CTX *ctx )
{
unsigned long long h = ctx->hash64;
digest[0] = h & 0xffU;
digest[1] = (h>>8) & 0xffU;
digest[2] = (h>>16) & 0xffU;
digest[3] = (h>>24) & 0xffU;
digest[4] = (h>>32) & 0xffU;
digest[5] = (h>>40) & 0xffU;
digest[6] = (h>>48) & 0xffU;
digest[7] = (h>>56) & 0xffU;
}
#endif /* HAVE_LONG_LONG */
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