1 /* hashkey.c -- definition of hash key type and helper functions
2 *
3 * Copyright (C) 2010,2011 Olaf Bergmann <bergmann@tzi.org>
4 *
5 * This file is part of the CoAP library libcoap. Please see
6 * README for terms of use.
7 */
8
9 #include "hashkey.h"
10
11 /* Caution: When changing this, update COAP_DEFAULT_WKC_HASHKEY
12 * accordingly (see int coap_hash_path());
13 */
14 void
coap_hash_impl(const unsigned char * s,unsigned int len,coap_key_t h)15 coap_hash_impl(const unsigned char *s, unsigned int len, coap_key_t h) {
16 size_t j;
17
18 while (len--) {
19 j = sizeof(coap_key_t)-1;
20
21 while (j) {
22 h[j] = ((h[j] << 7) | (h[j-1] >> 1)) + h[j];
23 --j;
24 }
25
26 h[0] = (h[0] << 7) + h[0] + *s++;
27 }
28 }
29
30
