1b528cefcSMark Murray /*
2*ae771770SStanislav Sedov * Copyright (c) 1997 - 2000 Kungliga Tekniska Högskolan
3b528cefcSMark Murray * (Royal Institute of Technology, Stockholm, Sweden).
4b528cefcSMark Murray * All rights reserved.
5b528cefcSMark Murray *
6b528cefcSMark Murray * Redistribution and use in source and binary forms, with or without
7b528cefcSMark Murray * modification, are permitted provided that the following conditions
8b528cefcSMark Murray * are met:
9b528cefcSMark Murray *
10b528cefcSMark Murray * 1. Redistributions of source code must retain the above copyright
11b528cefcSMark Murray * notice, this list of conditions and the following disclaimer.
12b528cefcSMark Murray *
13b528cefcSMark Murray * 2. Redistributions in binary form must reproduce the above copyright
14b528cefcSMark Murray * notice, this list of conditions and the following disclaimer in the
15b528cefcSMark Murray * documentation and/or other materials provided with the distribution.
16b528cefcSMark Murray *
17b528cefcSMark Murray * 3. Neither the name of the Institute nor the names of its contributors
18b528cefcSMark Murray * may be used to endorse or promote products derived from this software
19b528cefcSMark Murray * without specific prior written permission.
20b528cefcSMark Murray *
21b528cefcSMark Murray * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22b528cefcSMark Murray * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23b528cefcSMark Murray * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24b528cefcSMark Murray * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25b528cefcSMark Murray * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26b528cefcSMark Murray * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27b528cefcSMark Murray * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28b528cefcSMark Murray * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29b528cefcSMark Murray * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30b528cefcSMark Murray * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31b528cefcSMark Murray * SUCH DAMAGE.
32b528cefcSMark Murray */
33b528cefcSMark Murray
34b528cefcSMark Murray #include "krb5_locl.h"
35b528cefcSMark Murray
36b528cefcSMark Murray static u_long table[256];
37b528cefcSMark Murray
38b528cefcSMark Murray #define CRC_GEN 0xEDB88320L
39b528cefcSMark Murray
40b528cefcSMark Murray void
_krb5_crc_init_table(void)41b528cefcSMark Murray _krb5_crc_init_table(void)
42b528cefcSMark Murray {
43b528cefcSMark Murray static int flag = 0;
44b528cefcSMark Murray unsigned long crc, poly;
45*ae771770SStanislav Sedov unsigned int i, j;
46b528cefcSMark Murray
47b528cefcSMark Murray if(flag) return;
48b528cefcSMark Murray poly = CRC_GEN;
49b528cefcSMark Murray for (i = 0; i < 256; i++) {
50b528cefcSMark Murray crc = i;
51b528cefcSMark Murray for (j = 8; j > 0; j--) {
52b528cefcSMark Murray if (crc & 1) {
53b528cefcSMark Murray crc = (crc >> 1) ^ poly;
54b528cefcSMark Murray } else {
55b528cefcSMark Murray crc >>= 1;
56b528cefcSMark Murray }
57b528cefcSMark Murray }
58b528cefcSMark Murray table[i] = crc;
59b528cefcSMark Murray }
60b528cefcSMark Murray flag = 1;
61b528cefcSMark Murray }
62b528cefcSMark Murray
63c19800e8SDoug Rabson uint32_t
_krb5_crc_update(const char * p,size_t len,uint32_t res)64c19800e8SDoug Rabson _krb5_crc_update (const char *p, size_t len, uint32_t res)
65b528cefcSMark Murray {
66b528cefcSMark Murray while (len--)
67b528cefcSMark Murray res = table[(res ^ *p++) & 0xFF] ^ (res >> 8);
68b528cefcSMark Murray return res & 0xFFFFFFFF;
69b528cefcSMark Murray }
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