1*ebfedea0SLionel Sambuc /* $NetBSD: crc.c,v 1.1.1.1 2011/04/13 18:15:32 elric Exp $ */
2*ebfedea0SLionel Sambuc
3*ebfedea0SLionel Sambuc /*
4*ebfedea0SLionel Sambuc * Copyright (c) 1997 - 2000 Kungliga Tekniska Högskolan
5*ebfedea0SLionel Sambuc * (Royal Institute of Technology, Stockholm, Sweden).
6*ebfedea0SLionel Sambuc * All rights reserved.
7*ebfedea0SLionel Sambuc *
8*ebfedea0SLionel Sambuc * Redistribution and use in source and binary forms, with or without
9*ebfedea0SLionel Sambuc * modification, are permitted provided that the following conditions
10*ebfedea0SLionel Sambuc * are met:
11*ebfedea0SLionel Sambuc *
12*ebfedea0SLionel Sambuc * 1. Redistributions of source code must retain the above copyright
13*ebfedea0SLionel Sambuc * notice, this list of conditions and the following disclaimer.
14*ebfedea0SLionel Sambuc *
15*ebfedea0SLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright
16*ebfedea0SLionel Sambuc * notice, this list of conditions and the following disclaimer in the
17*ebfedea0SLionel Sambuc * documentation and/or other materials provided with the distribution.
18*ebfedea0SLionel Sambuc *
19*ebfedea0SLionel Sambuc * 3. Neither the name of the Institute nor the names of its contributors
20*ebfedea0SLionel Sambuc * may be used to endorse or promote products derived from this software
21*ebfedea0SLionel Sambuc * without specific prior written permission.
22*ebfedea0SLionel Sambuc *
23*ebfedea0SLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24*ebfedea0SLionel Sambuc * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25*ebfedea0SLionel Sambuc * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26*ebfedea0SLionel Sambuc * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27*ebfedea0SLionel Sambuc * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28*ebfedea0SLionel Sambuc * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29*ebfedea0SLionel Sambuc * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30*ebfedea0SLionel Sambuc * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31*ebfedea0SLionel Sambuc * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32*ebfedea0SLionel Sambuc * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33*ebfedea0SLionel Sambuc * SUCH DAMAGE.
34*ebfedea0SLionel Sambuc */
35*ebfedea0SLionel Sambuc
36*ebfedea0SLionel Sambuc #include "krb5_locl.h"
37*ebfedea0SLionel Sambuc
38*ebfedea0SLionel Sambuc static u_long table[256];
39*ebfedea0SLionel Sambuc
40*ebfedea0SLionel Sambuc #define CRC_GEN 0xEDB88320L
41*ebfedea0SLionel Sambuc
42*ebfedea0SLionel Sambuc void
_krb5_crc_init_table(void)43*ebfedea0SLionel Sambuc _krb5_crc_init_table(void)
44*ebfedea0SLionel Sambuc {
45*ebfedea0SLionel Sambuc static int flag = 0;
46*ebfedea0SLionel Sambuc unsigned long crc, poly;
47*ebfedea0SLionel Sambuc unsigned int i, j;
48*ebfedea0SLionel Sambuc
49*ebfedea0SLionel Sambuc if(flag) return;
50*ebfedea0SLionel Sambuc poly = CRC_GEN;
51*ebfedea0SLionel Sambuc for (i = 0; i < 256; i++) {
52*ebfedea0SLionel Sambuc crc = i;
53*ebfedea0SLionel Sambuc for (j = 8; j > 0; j--) {
54*ebfedea0SLionel Sambuc if (crc & 1) {
55*ebfedea0SLionel Sambuc crc = (crc >> 1) ^ poly;
56*ebfedea0SLionel Sambuc } else {
57*ebfedea0SLionel Sambuc crc >>= 1;
58*ebfedea0SLionel Sambuc }
59*ebfedea0SLionel Sambuc }
60*ebfedea0SLionel Sambuc table[i] = crc;
61*ebfedea0SLionel Sambuc }
62*ebfedea0SLionel Sambuc flag = 1;
63*ebfedea0SLionel Sambuc }
64*ebfedea0SLionel Sambuc
65*ebfedea0SLionel Sambuc uint32_t
_krb5_crc_update(const char * p,size_t len,uint32_t res)66*ebfedea0SLionel Sambuc _krb5_crc_update (const char *p, size_t len, uint32_t res)
67*ebfedea0SLionel Sambuc {
68*ebfedea0SLionel Sambuc while (len--)
69*ebfedea0SLionel Sambuc res = table[(res ^ *p++) & 0xFF] ^ (res >> 8);
70*ebfedea0SLionel Sambuc return res & 0xFFFFFFFF;
71*ebfedea0SLionel Sambuc }
72