1 /* $NetBSD: crc.c,v 1.22 2021/03/18 18:12:35 cheusov Exp $ */
2
3 /*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * James W. Williams of NASA Goddard Space Flight Center.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #if HAVE_NBTOOL_CONFIG_H
36 #include "nbtool_config.h"
37 #endif
38
39 #include <sys/cdefs.h>
40 #if defined(__RCSID) && !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)crc.c 8.1 (Berkeley) 6/17/93";
43 #else
44 __RCSID("$NetBSD: crc.c,v 1.22 2021/03/18 18:12:35 cheusov Exp $");
45 #endif
46 #endif /* not lint */
47
48 #include <sys/types.h>
49 #include <sys/endian.h>
50
51 #include <unistd.h>
52
53 #include "extern.h"
54
55 static const uint32_t crctab[] = {
56 0x0,
57 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
58 0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6,
59 0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
60 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac,
61 0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f,
62 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a,
63 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
64 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58,
65 0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033,
66 0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe,
67 0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
68 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4,
69 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
70 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5,
71 0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
72 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07,
73 0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c,
74 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1,
75 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
76 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b,
77 0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698,
78 0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d,
79 0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
80 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f,
81 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
82 0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80,
83 0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
84 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a,
85 0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629,
86 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c,
87 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
88 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e,
89 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65,
90 0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8,
91 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
92 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2,
93 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
94 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74,
95 0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
96 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21,
97 0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a,
98 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087,
99 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
100 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d,
101 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce,
102 0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb,
103 0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
104 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09,
105 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
106 0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf,
107 0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
108 };
109
110 /*
111 * Compute a POSIX 1003.2 checksum. This routine has been broken out so that
112 * other programs can use it. It takes a file descriptor to read from and
113 * locations to store the crc and the number of bytes read. It returns 0 on
114 * success and 1 on failure. Errno is set on failure.
115 */
116 int
crc(int fd,uint32_t * cval,off_t * clen)117 crc(int fd, uint32_t *cval, off_t *clen)
118 {
119 ssize_t nr;
120 uint32_t thecrc;
121 off_t len;
122 u_char buf[16 * 1024];
123
124 thecrc = 0;
125 len = 0;
126 while ((nr = read(fd, buf, sizeof(buf))) > 0) {
127 thecrc = crc_buf(thecrc, buf, (size_t)nr);
128 len += nr;
129 }
130 if (nr < 0)
131 return 1;
132
133 *clen = len;
134
135 /* Include the length of the file. */
136 for (; len != 0; len >>= 8) {
137 thecrc = crc_byte(thecrc, len & 0xff);
138 }
139
140 *cval = ~thecrc;
141 return 0;
142 }
143
144 #define COMPUTE(var, ch) (var) = (var) << 8 ^ crctab[(var) >> 24 ^ (ch)]
145
146 static uint32_t crcslice[15][256];
147
148 static void
tables(void)149 tables(void)
150 {
151 int a, b;
152
153 for (a = 0; a < 256; a++) {
154 uint32_t crc = crctab[a];
155 for (b = 0; b < 15; b++) {
156 COMPUTE(crc, 0);
157 crcslice[b][a] = crc;
158 }
159 }
160 }
161
162 /* These two are rather more useful to the outside world */
163
164 uint32_t
crc_buf(uint32_t thecrc,const void * buf,size_t len)165 crc_buf(uint32_t thecrc, const void *buf, size_t len)
166 {
167 const uint8_t *p = buf;
168
169 /* Compute the tables once. */
170 if (crcslice[14][255] == 0)
171 tables();
172
173 for (; len >= 16; p += 16, len -= 16) {
174 uint32_t a = be32dec(p + 0) ^ thecrc;
175 uint32_t b = be32dec(p + 4);
176 uint32_t c = be32dec(p + 8);
177 uint32_t d = be32dec(p + 12);
178 thecrc =
179 crcslice[14][a >> 24 & 0xff] ^
180 crcslice[13][a >> 16 & 0xff] ^
181 crcslice[12][a >> 8 & 0xff] ^
182 crcslice[11][a >> 0 & 0xff] ^
183 crcslice[10][b >> 24 & 0xff] ^
184 crcslice[9][b >> 16 & 0xff] ^
185 crcslice[8][b >> 8 & 0xff] ^
186 crcslice[7][b >> 0 & 0xff] ^
187 crcslice[6][c >> 24 & 0xff] ^
188 crcslice[5][c >> 16 & 0xff] ^
189 crcslice[4][c >> 8 & 0xff] ^
190 crcslice[3][c >> 0 & 0xff] ^
191 crcslice[2][d >> 24 & 0xff] ^
192 crcslice[1][d >> 16 & 0xff] ^
193 crcslice[0][d >> 8 & 0xff] ^
194 crctab[d >> 0 & 0xff];
195 }
196
197 for (; len; p++, len--)
198 COMPUTE(thecrc, *p);
199
200 return thecrc;
201 }
202
203 uint32_t
crc_byte(uint32_t thecrc,unsigned int byte_val)204 crc_byte(uint32_t thecrc, unsigned int byte_val)
205 {
206 COMPUTE(thecrc, byte_val & 0xff);
207 return thecrc;
208 }
209