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68 lines
1.1 KiB
C
68 lines
1.1 KiB
C
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/* $OpenLDAP$ */
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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 <ac/string.h>
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/* include socket.h to get sys/types.h and/or winsock2.h */
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#include <ac/socket.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 0x811c9dc5
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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( struct lutil_HASHContext *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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struct lutil_HASHContext *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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{
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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, struct lutil_HASHContext *ctx )
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{
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ber_uint_t h = ctx->hash;
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digest[0] = h & 0xff;
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digest[1] = (h>>8) & 0xff;
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digest[2] = (h>>16) & 0xff;
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digest[3] = (h>>24) & 0xff;
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}
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