/*----------------------------------------------------------------------------*\ * CRC-32 version 2.0.0 by Craig Bruce, 2006-04-29. * * This program generates the CRC-32 values for the files named in the * command-line arguments. These are the same CRC-32 values used by GZIP, * PKZIP, and ZMODEM. The Crc32_ComputeBuf() can also be detached and * used independently. * * THIS PROGRAM IS PUBLIC-DOMAIN SOFTWARE. * * Based on the byte-oriented implementation "File Verification Using CRC" * by Mark R. Nelson in Dr. Dobb's Journal, May 1992, pp. 64-67. * * v1.0.0: original release. * v1.0.1: fixed printf formats. * v1.0.2: fixed something else. * v1.0.3: replaced CRC constant table by generator function. * v1.0.4: reformatted code, made ANSI C. 1994-12-05. * v2.0.0: rewrote to use memory buffer & static table, 2006-04-29. \*----------------------------------------------------------------------------*/ #include #include /*----------------------------------------------------------------------------*\ * Local functions \*----------------------------------------------------------------------------*/ static int Crc32_ComputeFile( FILE *file, unsigned long *outCrc32 ); static unsigned long Crc32_ComputeBuf( unsigned long inCrc32, const void *buf, size_t bufLen ); /*----------------------------------------------------------------------------*\ * NAME: * main() - main function for CRC-32 generation * DESCRIPTION: * Computes the CRC-32 value for the set of files named in the command- * line arguments. * ARGUMENTS: * argc - command-line-argument count * argv - command-line-argument strings * RETURNS: * err - 0 on success or executes exit(1) on error * ERRORS: * - file errors \*----------------------------------------------------------------------------*/ int main( int argc, const char *argv[] ) { FILE *file = NULL; const char *filename; unsigned long argIdx; unsigned long crc32; int err; /** compute crcs **/ if (argc < 2) { /** read from 'stdin' if no arguments given **/ err = Crc32_ComputeFile( stdin, &crc32 ); if (err == -1) goto ERR_EXIT; printf("crc32 = 0x%08lX for (stdin)\n", crc32 ); } else { /** report named files in sequence **/ for (argIdx=1; argIdx < argc; argIdx++) { filename = argv[argIdx]; file = fopen( filename, "rb" ); if (file == NULL) { fprintf( stderr, "error opening file \"%s\"!\n", filename ); goto ERR_EXIT; } err = Crc32_ComputeFile( file, &crc32 ); if (err == -1) goto ERR_EXIT; printf("crc32 = 0x%08lX for \"%s\"\n", crc32, filename ); err = fclose( file ); file = NULL; if (err == EOF) { fprintf( stderr, "error closing file \"%s\"!\n", filename ); goto ERR_EXIT; } } } return( 0 ); /** error exit **/ ERR_EXIT: if (file != NULL) fclose( file ); exit( 1 ); } /*----------------------------------------------------------------------------*\ * NAME: * Crc32_ComputeFile() - compute CRC-32 value for a file * DESCRIPTION: * Computes the CRC-32 value for an opened file. * ARGUMENTS: * file - file pointer * outCrc32 - (out) result CRC-32 value * RETURNS: * err - 0 on success or -1 on error * ERRORS: * - file errors \*----------------------------------------------------------------------------*/ static int Crc32_ComputeFile( FILE *file, unsigned long *outCrc32 ) { # define CRC_BUFFER_SIZE 8192 unsigned char buf[CRC_BUFFER_SIZE]; size_t bufLen; /** accumulate crc32 from file **/ *outCrc32 = 0; while (1) { bufLen = fread( buf, 1, CRC_BUFFER_SIZE, file ); if (bufLen == 0) { if (ferror(file)) { fprintf( stderr, "error reading file\n" ); goto ERR_EXIT; } break; } *outCrc32 = Crc32_ComputeBuf( *outCrc32, buf, bufLen ); } return( 0 ); /** error exit **/ ERR_EXIT: return( -1 ); } /*----------------------------------------------------------------------------*\ * NAME: * Crc32_ComputeBuf() - computes the CRC-32 value of a memory buffer * DESCRIPTION: * Computes or accumulates the CRC-32 value for a memory buffer. * The 'inCrc32' gives a previously accumulated CRC-32 value to allow * a CRC to be generated for multiple sequential buffer-fuls of data. * The 'inCrc32' for the first buffer must be zero. * ARGUMENTS: * inCrc32 - accumulated CRC-32 value, must be 0 on first call * buf - buffer to compute CRC-32 value for * bufLen - number of bytes in buffer * RETURNS: * crc32 - computed CRC-32 value * ERRORS: * (no errors are possible) \*----------------------------------------------------------------------------*/ static unsigned long Crc32_ComputeBuf( unsigned long inCrc32, const void *buf, size_t bufLen ) { static const unsigned long crcTable[256] = { 0x00000000,0x77073096,0xEE0E612C,0x990951BA,0x076DC419,0x706AF48F,0xE963A535, 0x9E6495A3,0x0EDB8832,0x79DCB8A4,0xE0D5E91E,0x97D2D988,0x09B64C2B,0x7EB17CBD, 0xE7B82D07,0x90BF1D91,0x1DB71064,0x6AB020F2,0xF3B97148,0x84BE41DE,0x1ADAD47D, 0x6DDDE4EB,0xF4D4B551,0x83D385C7,0x136C9856,0x646BA8C0,0xFD62F97A,0x8A65C9EC, 0x14015C4F,0x63066CD9,0xFA0F3D63,0x8D080DF5,0x3B6E20C8,0x4C69105E,0xD56041E4, 0xA2677172,0x3C03E4D1,0x4B04D447,0xD20D85FD,0xA50AB56B,0x35B5A8FA,0x42B2986C, 0xDBBBC9D6,0xACBCF940,0x32D86CE3,0x45DF5C75,0xDCD60DCF,0xABD13D59,0x26D930AC, 0x51DE003A,0xC8D75180,0xBFD06116,0x21B4F4B5,0x56B3C423,0xCFBA9599,0xB8BDA50F, 0x2802B89E,0x5F058808,0xC60CD9B2,0xB10BE924,0x2F6F7C87,0x58684C11,0xC1611DAB, 0xB6662D3D,0x76DC4190,0x01DB7106,0x98D220BC,0xEFD5102A,0x71B18589,0x06B6B51F, 0x9FBFE4A5,0xE8B8D433,0x7807C9A2,0x0F00F934,0x9609A88E,0xE10E9818,0x7F6A0DBB, 0x086D3D2D,0x91646C97,0xE6635C01,0x6B6B51F4,0x1C6C6162,0x856530D8,0xF262004E, 0x6C0695ED,0x1B01A57B,0x8208F4C1,0xF50FC457,0x65B0D9C6,0x12B7E950,0x8BBEB8EA, 0xFCB9887C,0x62DD1DDF,0x15DA2D49,0x8CD37CF3,0xFBD44C65,0x4DB26158,0x3AB551CE, 0xA3BC0074,0xD4BB30E2,0x4ADFA541,0x3DD895D7,0xA4D1C46D,0xD3D6F4FB,0x4369E96A, 0x346ED9FC,0xAD678846,0xDA60B8D0,0x44042D73,0x33031DE5,0xAA0A4C5F,0xDD0D7CC9, 0x5005713C,0x270241AA,0xBE0B1010,0xC90C2086,0x5768B525,0x206F85B3,0xB966D409, 0xCE61E49F,0x5EDEF90E,0x29D9C998,0xB0D09822,0xC7D7A8B4,0x59B33D17,0x2EB40D81, 0xB7BD5C3B,0xC0BA6CAD,0xEDB88320,0x9ABFB3B6,0x03B6E20C,0x74B1D29A,0xEAD54739, 0x9DD277AF,0x04DB2615,0x73DC1683,0xE3630B12,0x94643B84,0x0D6D6A3E,0x7A6A5AA8, 0xE40ECF0B,0x9309FF9D,0x0A00AE27,0x7D079EB1,0xF00F9344,0x8708A3D2,0x1E01F268, 0x6906C2FE,0xF762575D,0x806567CB,0x196C3671,0x6E6B06E7,0xFED41B76,0x89D32BE0, 0x10DA7A5A,0x67DD4ACC,0xF9B9DF6F,0x8EBEEFF9,0x17B7BE43,0x60B08ED5,0xD6D6A3E8, 0xA1D1937E,0x38D8C2C4,0x4FDFF252,0xD1BB67F1,0xA6BC5767,0x3FB506DD,0x48B2364B, 0xD80D2BDA,0xAF0A1B4C,0x36034AF6,0x41047A60,0xDF60EFC3,0xA867DF55,0x316E8EEF, 0x4669BE79,0xCB61B38C,0xBC66831A,0x256FD2A0,0x5268E236,0xCC0C7795,0xBB0B4703, 0x220216B9,0x5505262F,0xC5BA3BBE,0xB2BD0B28,0x2BB45A92,0x5CB36A04,0xC2D7FFA7, 0xB5D0CF31,0x2CD99E8B,0x5BDEAE1D,0x9B64C2B0,0xEC63F226,0x756AA39C,0x026D930A, 0x9C0906A9,0xEB0E363F,0x72076785,0x05005713,0x95BF4A82,0xE2B87A14,0x7BB12BAE, 0x0CB61B38,0x92D28E9B,0xE5D5BE0D,0x7CDCEFB7,0x0BDBDF21,0x86D3D2D4,0xF1D4E242, 0x68DDB3F8,0x1FDA836E,0x81BE16CD,0xF6B9265B,0x6FB077E1,0x18B74777,0x88085AE6, 0xFF0F6A70,0x66063BCA,0x11010B5C,0x8F659EFF,0xF862AE69,0x616BFFD3,0x166CCF45, 0xA00AE278,0xD70DD2EE,0x4E048354,0x3903B3C2,0xA7672661,0xD06016F7,0x4969474D, 0x3E6E77DB,0xAED16A4A,0xD9D65ADC,0x40DF0B66,0x37D83BF0,0xA9BCAE53,0xDEBB9EC5, 0x47B2CF7F,0x30B5FFE9,0xBDBDF21C,0xCABAC28A,0x53B39330,0x24B4A3A6,0xBAD03605, 0xCDD70693,0x54DE5729,0x23D967BF,0xB3667A2E,0xC4614AB8,0x5D681B02,0x2A6F2B94, 0xB40BBE37,0xC30C8EA1,0x5A05DF1B,0x2D02EF8D }; unsigned long crc32; unsigned char *byteBuf; size_t i; /** accumulate crc32 for buffer **/ crc32 = inCrc32 ^ 0xFFFFFFFF; byteBuf = (unsigned char*) buf; for (i=0; i < bufLen; i++) { crc32 = (crc32 >> 8) ^ crcTable[ (crc32 ^ byteBuf[i]) & 0xFF ]; } return( crc32 ^ 0xFFFFFFFF ); } /*----------------------------------------------------------------------------*\ * END OF MODULE: crc32.c \*----------------------------------------------------------------------------*/