mirror of
https://git.openldap.org/openldap/openldap.git
synced 2024-12-27 03:20:22 +08:00
142 lines
2.5 KiB
C
142 lines
2.5 KiB
C
/* $OpenLDAP$ */
|
|
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
|
|
*
|
|
* Copyright 2000-2015 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 */
|