dlls/dbghelp/crc32.c

   1 /*
   2  * File crc32.c - calculate CRC32 checksum of a file
   3  *
   4  * Copyright (C) 1996, Eric Youngdale.
   5  *               1999-2007 Eric Pouech
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  */
  21
  22 #include "config.h"
  23 #include "wine/port.h"
  24
  25 #include <stdio.h>
  26
  27 #include "dbghelp_private.h"
  28
  29 /* Copyright (C) 1986 Gary S. Brown
  30  * Modified by Robert Shearman. You may use the following calc_crc32 code or
  31  * tables extracted from it, as desired without restriction. */
  32
  33 /**********************************************************************\
  34 |* Demonstration program to compute the 32-bit CRC used as the frame  *|
  35 |* check sequence in ADCCP (ANSI X3.66, also known as FIPS PUB 71     *|
  36 |* and FED-STD-1003, the U.S. versions of CCITT's X.25 link-level     *|
  37 |* protocol).  The 32-bit FCS was added via the Federal Register,     *|
  38 |* 1 June 1982, p.23798.  I presume but don't know for certain that   *|
  39 |* this polynomial is or will be included in CCITT V.41, which        *|
  40 |* defines the 16-bit CRC (often called CRC-CCITT) polynomial.  FIPS  *|
  41 |* PUB 78 says that the 32-bit FCS reduces otherwise undetected       *|
  42 |* errors by a factor of 10^-5 over 16-bit FCS.                       *|
  43 \**********************************************************************/
  44
  45 /* First, the polynomial itself and its table of feedback terms.  The  */
  46 /* polynomial is                                                       */
  47 /* X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0 */
  48 /* Note that we take it "backwards" and put the highest-order term in  */
  49 /* the lowest-order bit.  The X^32 term is "implied"; the LSB is the   */
  50 /* X^31 term, etc.  The X^0 term (usually shown as "+1") results in    */
  51 /* the MSB being 1.                                                    */
  52
  53 /* Note that the usual hardware shift register implementation, which   */
  54 /* is what we're using (we're merely optimizing it by doing eight-bit  */
  55 /* chunks at a time) shifts bits into the lowest-order term.  In our   */
  56 /* implementation, that means shifting towards the right.  Why do we   */
  57 /* do it this way?  Because the calculated CRC must be transmitted in  */
  58 /* order from highest-order term to lowest-order term.  UARTs transmit */
  59 /* characters in order from LSB to MSB.  By storing the CRC this way,  */
  60 /* we hand it to the UART in the order low-byte to high-byte; the UART */
  61 /* sends each low-bit to hight-bit; and the result is transmission bit */
  62 /* by bit from highest- to lowest-order term without requiring any bit */
  63 /* shuffling on our part.  Reception works similarly.                  */
  64
  65 /* The feedback terms table consists of 256, 32-bit entries.  Notes:   */
  66 /*                                                                     */
  67 /*  1. The table can be generated at runtime if desired; code to do so */
  68 /*     is shown later.  It might not be obvious, but the feedback      */
  69 /*     terms simply represent the results of eight shift/xor opera-    */
  70 /*     tions for all combinations of data and CRC register values.     */
  71 /*                                                                     */
  72 /*  2. The CRC accumulation logic is the same for all CRC polynomials, */
  73 /*     be they sixteen or thirty-two bits wide.  You simply choose the */
  74 /*     appropriate table.  Alternatively, because the table can be     */
  75 /*     generated at runtime, you can start by generating the table for */
  76 /*     the polynomial in question and use exactly the same "updcrc",   */
  77 /*     if your application needn't simultaneously handle two CRC       */
  78 /*     polynomials.  (Note, however, that XMODEM is strange.)          */
  79 /*                                                                     */
  80 /*  3. For 16-bit CRCs, the table entries need be only 16 bits wide;   */
  81 /*     of course, 32-bit entries work OK if the high 16 bits are zero. */
  82 /*                                                                     */
  83 /*  4. The values must be right-shifted by eight bits by the "updcrc"  */
  84 /*     logic; the shift must be unsigned (bring in zeroes).  On some   */
  85 /*     hardware you could probably optimize the shift in assembler by  */
  86 /*     using byte-swap instructions.                                   */
  87
  88
  89 DWORD calc_crc32(int fd)
  90 {
  91 #define UPDC32(octet,crc) (crc_32_tab[((crc) ^ (octet)) & 0xff] ^ ((crc) >> 8))
  92     static const DWORD crc_32_tab[] =
  93     { /* CRC polynomial 0xedb88320 */
  94         0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
  95         0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
  96         0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
  97         0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
  98         0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
  99         0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
 100         0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
 101         0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
 102         0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
 103         0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
 104         0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
 105         0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
 106         0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
 107         0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
 108         0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
 109         0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
 110         0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
 111         0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
 112         0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
 113         0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
 114         0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
 115         0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
 116         0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
 117         0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
 118         0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
 119         0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
 120         0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
 121         0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
 122         0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
 123         0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
 124         0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
 125         0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
 126         0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
 127         0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
 128         0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
 129         0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
 130         0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
 131         0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
 132         0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
 133         0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
 134         0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
 135         0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
 136         0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
 137     };
 138     int                 i, r;
 139     unsigned char       buffer[8192];
 140     DWORD               crc = ~0;
 141
 142     lseek(fd, 0, SEEK_SET);
 143     while ((r = read(fd, buffer, sizeof(buffer))) > 0)
 144     {
 145         for (i = 0; i < r; i++) crc = UPDC32(buffer[i], crc);
 146     }
 147     return ~crc;
 148 #undef UPDC32
 149 }