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/*
// Copyright (c) 2010-2017 Intel Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
*/
#include <stdio.h>
#include <stdint.h>
#include "toeplitz.h"
/* From XL710 Datasheet, 7.1.10 */
uint8_t toeplitz_init_key[TOEPLITZ_KEY_LEN] =
{0x6d, 0x5a, 0x56, 0xda, 0x25, 0x5b, 0x8f, 0xb0,
0x41, 0x67, 0x25, 0x3d, 0x43, 0xa3, 0x8f, 0xb0,
0xd0, 0xca, 0x2b, 0xcb, 0xae, 0x7b, 0x30, 0xb4,
0x77, 0xcb, 0x2d, 0xa3, 0x80, 0x30, 0xf2, 0x0c,
0x6a, 0x42, 0xb7, 0x3b, 0xbe, 0xac, 0x01, 0xfa
};
uint32_t toeplitz_hash(uint8_t *buf_p, int buflen)
{
uint32_t result = 0;
uint8_t *key_p = toeplitz_init_key;
uint8_t byte, *byte4_p = key_p+4;
int i, pos = 0;
int bit = 0;
uint32_t key_word = __builtin_bswap32(*(uint32_t *)key_p);
for (i = 0; i < buflen; ++i) {
byte = buf_p[i];
for (bit = 0; bit <= 7; ++bit) {
if (byte & (1 << (7 - bit))) {
result ^= key_word;
}
key_word = (key_word << 1) | ((*byte4_p >> (7 - bit)) & 1);
}
if (pos >= TOEPLITZ_KEY_LEN - 4) {
pos = 0;
byte4_p = key_p;
}
else {
pos++;
byte4_p++;
}
}
return result;
}
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