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 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 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 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 204 crc_byte(uint32_t thecrc, unsigned int byte_val) 205 { 206 COMPUTE(thecrc, byte_val & 0xff); 207 return thecrc; 208 } 209
Indexes created Sat Sep 20 22:09:52 GMT 2025