我有一个为VxWorks派生的PowerPC平台编写的C ++运行时编译运行时脚本，它为嵌入式操作系统上的文件计算校验和。它使用一对查找表来计算校验和（请参阅下面的代码）。
我正在尝试移植此脚本以在Windows上使用，因为该平台规定我必须为每个我希望计算校验和的文件硬编码新脚本，并且我正在努力做到这一点需要很多时间。我需要更改平台文件系统上的一堆文件，并将它们的校验和提供给系统，否则它将拒绝加载它们。
我已经运行了代码，已经更改了所有的UI /输出和文件输入内容以使用Windows，但是我得到了错误的校验和。在我的测试文件中，我应该得到404f而我实际上得到5fb4。
做了一些研究后，我相信我可能需要转换或重新生成查找表，但我不知道如何解决这个问题，并且对任何输入都会感激不尽。
谢谢！
// rt6_crc_checker.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#define TRUE 1
#define FALSE 0
#define SKIP 1
#include <windows.h>
#include <iostream>
#include <cstdlib>
#include <sys/stat.h>
using namespace std;
int PL_FileExists( char *p_pPath );
void PL_itoa10( int i , char* s );
void PL_itoa16( int i , char* s );
int change_endian(int num){
int byte0, byte1, byte2, byte3;
byte0 = (num & 0x000000FF) >> 0 ;
byte1 = (num & 0x0000FF00) >> 8 ;
byte2 = (num & 0x00FF0000) >> 16 ;
byte3 = (num & 0xFF000000) >> 24 ;
return((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | (byte3 << 0));
}
/*** MAIN ***/
int main ( int argc, char **argv )
{
char carlu;
char s_nb[16];
char s_i[16];
char CRC_FIC[16];
char CRC_INF[16];
char MessPL[256];
int nb;
int size_FIC;
int size_INF;
int answ;
int CRC;
int c1;
int c2;
int rg;
int i;
int j;
FILE *l_fileIN;
FILE *l_fileOUT;
char l_line[20];
int table_h[]=
{
0x00, 0xdf, 0xbe, 0x61, 0x7c, 0xa3, 0xc2, 0x1d, 0xd3, 0x0c, 0x6d, 0xb2, 0xaf, 0x70, 0x11, 0xce,
0x8d, 0x52, 0x33, 0xec, 0xf1, 0x2e, 0x4f, 0x90, 0x5e, 0x81, 0xe0, 0x3f, 0x22, 0xfd, 0x9c, 0x43,
0x1a, 0xc5, 0xa4, 0x7b, 0x66, 0xb9, 0xd8, 0x07, 0xc9, 0x16, 0x77, 0xa8, 0xb5, 0x6a, 0x0b, 0xd4,
0x97, 0x48, 0x29, 0xf6, 0xeb, 0x34, 0x55, 0x8a, 0x44, 0x9b, 0xfa, 0x25, 0x38, 0xe7, 0x86, 0x59,
0x1f, 0xc0, 0xa1, 0x7e, 0x63, 0xbc, 0xdd, 0x02, 0xcc, 0x13, 0x72, 0xad, 0xb0, 0x6f, 0x0e, 0xd1,
0x92, 0x4d, 0x2c, 0xf3, 0xee, 0x31, 0x50, 0x8f, 0x41, 0x9e, 0xff, 0x20, 0x3d, 0xe2, 0x83, 0x5c,
0x05, 0xda, 0xbb, 0x64, 0x79, 0xa6, 0xc7, 0x18, 0xd6, 0x09, 0x68, 0xb7, 0xaa, 0x75, 0x14, 0xcb,
0x88, 0x57, 0x36, 0xe9, 0xf4, 0x2b, 0x4a, 0x95, 0x5b, 0x84, 0xe5, 0x3a, 0x27, 0xf8, 0x99, 0x46,
0x15, 0xca, 0xab, 0x74, 0x69, 0xb6, 0xd7, 0x08, 0xc6, 0x19, 0x78, 0xa7, 0xba, 0x65, 0x04, 0xdb,
0x98, 0x47, 0x26, 0xf9, 0xe4, 0x3b, 0x5a, 0x85, 0x4b, 0x94, 0xf5, 0x2a, 0x37, 0xe8, 0x89, 0x56,
0x0f, 0xd0, 0xb1, 0x6e, 0x73, 0xac, 0xcd, 0x12, 0xdc, 0x03, 0x62, 0xbd, 0xa0, 0x7f, 0x1e, 0xc1,
0x82, 0x5d, 0x3c, 0xe3, 0xfe, 0x21, 0x40, 0x9f, 0x51, 0x8e, 0xef, 0x30, 0x2d, 0xf2, 0x93, 0x4c,
0x0a, 0xd5, 0xb4, 0x6b, 0x76, 0xa9, 0xc8, 0x17, 0xd9, 0x06, 0x67, 0xb8, 0xa5, 0x7a, 0x1b, 0xc4,
0x87, 0x58, 0x39, 0xe6, 0xfb, 0x24, 0x45, 0x9a, 0x54, 0x8b, 0xea, 0x35, 0x28, 0xf7, 0x96, 0x49,
0x10, 0xcf, 0xae, 0x71, 0x6c, 0xb3, 0xd2, 0x0d, 0xc3, 0x1c, 0x7d, 0xa2, 0xbf, 0x60, 0x01, 0xde,
0x9d, 0x42, 0x23, 0xfc, 0xe1, 0x3e, 0x5f, 0x80, 0x4e, 0x91, 0xf0, 0x2f, 0x32, 0xed, 0x8c, 0x53
};
int table_l[]=
{
0x00, 0x2b, 0x57, 0x7c, 0xaf, 0x84, 0xf8, 0xd3, 0xf6, 0xdd, 0xa1, 0x8a, 0x59, 0x72, 0x0e, 0x25,
0x45, 0x6e, 0x12, 0x39, 0xea, 0xc1, 0xbd, 0x96, 0xb3, 0x98, 0xe4, 0xcf, 0x1c, 0x37, 0x4b, 0x60,
0x8b, 0xa0, 0xdc, 0xf7, 0x24, 0x0f, 0x73, 0x58, 0x7d, 0x56, 0x2a, 0x01, 0xd2, 0xf9, 0x85, 0xae,
0xce, 0xe5, 0x99, 0xb2, 0x61, 0x4a, 0x36, 0x1d, 0x38, 0x13, 0x6f, 0x44, 0x97, 0xbc, 0xc0, 0xeb,
0xbe, 0x95, 0xe9, 0xc2, 0x11, 0x3a, 0x46, 0x6d, 0x48, 0x63, 0x1f, 0x34, 0xe7, 0xcc, 0xb0, 0x9b,
0xfb, 0xd0, 0xac, 0x87, 0x54, 0x7f, 0x03, 0x28, 0x0d, 0x26, 0x5a, 0x71, 0xa2, 0x89, 0xf5, 0xde,
0x35, 0x1e, 0x62, 0x49, 0x9a, 0xb1, 0xcd, 0xe6, 0xc3, 0xe8, 0x94, 0xbf, 0x6c, 0x47, 0x3b, 0x10,
0x70, 0x5b, 0x27, 0x0c, 0xdf, 0xf4, 0x88, 0xa3, 0x86, 0xad, 0xd1, 0xfa, 0x29, 0x02, 0x7e, 0x55,
0xd4, 0xff, 0x83, 0xa8, 0x7b, 0x50, 0x2c, 0x07, 0x22, 0x09, 0x75, 0x5e, 0x8d, 0xa6, 0xda, 0xf1,
0x91, 0xba, 0xc6, 0xed, 0x3e, 0x15, 0x69, 0x42, 0x67, 0x4c, 0x30, 0x1b, 0xc8, 0xe3, 0x9f, 0xb4,
0x5f, 0x74, 0x08, 0x23, 0xf0, 0xdb, 0xa7, 0x8c, 0xa9, 0x82, 0xfe, 0xd5, 0x06, 0x2d, 0x51, 0x7a,
0x1a, 0x31, 0x4d, 0x66, 0xb5, 0x9e, 0xe2, 0xc9, 0xec, 0xc7, 0xbb, 0x90, 0x43, 0x68, 0x14, 0x3f,
0x6a, 0x41, 0x3d, 0x16, 0xc5, 0xee, 0x92, 0xb9, 0x9c, 0xb7, 0xcb, 0xe0, 0x33, 0x18, 0x64, 0x4f,
0x2f, 0x04, 0x78, 0x53, 0x80, 0xab, 0xd7, 0xfc, 0xd9, 0xf2, 0x8e, 0xa5, 0x76, 0x5d, 0x21, 0x0a,
0xe1, 0xca, 0xb6, 0x9d, 0x4e, 0x65, 0x19, 0x32, 0x17, 0x3c, 0x40, 0x6b, 0xb8, 0x93, 0xef, 0xc4,
0xa4, 0x8f, 0xf3, 0xd8, 0x0b, 0x20, 0x5c, 0x77, 0x52, 0x79, 0x05, 0x2e, 0xfd, 0xd6, 0xaa, 0x81
};
i = 0;
j = 0;
size_FIC = 0;
size_INF = 0;
c1 = 0;
c2 = 0;
rg = 0;
CRC = 0;
if ( PL_FileExists( "crc_check.ext" ) != TRUE )
{
cout << "input MISSING !";
return 0;
}
struct stat stat_buf;
int rc = stat("crc_check.ext", &stat_buf);
size_FIC = rc == 0 ? stat_buf.st_size : -1;
cout << "input found " << size_FIC << endl;
PL_itoa10 ( size_FIC , s_nb );
strcpy ( MessPL , "Size : " );
strcat ( MessPL , s_nb );
strcat ( MessPL , " K..." );
cout << MessPL << endl;
// Calculate CRC...
l_fileIN = fopen ( "crc_check.ext", "r");
if ( NULL == l_fileIN )
{
cout << "Error opening" << endl;
}
else
{
cout << "Ok will calculate CRC bear with" << endl;
c1 = 0;
c2 = 0;
rg = 0;
for ( i = 0 ; i < size_FIC ; i++ )
{
fseek ( l_fileIN , i , 0 );
if ( i % 4000 == 0 )
{
j = ( 100 * i ) / size_FIC ;
}
if ( NULL == fgets ( l_line , 2 , l_fileIN ) )
{
PL_itoa10 ( i , s_i );
strcpy ( MessPL , "READ Error ! " );
strcat ( MessPL , s_i );
cout << MessPL << endl;
i = size_FIC;
}
else
{
nb = (int) l_line[0];
if ( nb < 0 )
nb += 256;
rg = c1 ^ nb;
c1 = c2 ^ table_h[rg];
c2 = table_l[rg];
}
}
fclose(l_fileIN);
}
PL_itoa16 ( c1 , s_nb );
if ( c1 < 16 )
{
strcpy ( CRC_FIC , "0" );
strcat ( CRC_FIC , s_nb );
}
else
strcpy ( CRC_FIC , s_nb );
PL_itoa16 ( c2 , s_nb );
if ( c2 < 16 )
{
strcat ( CRC_FIC , "0" );
strcat ( CRC_FIC , s_nb );
}
else
strcat ( CRC_FIC , s_nb );
cout << CRC_FIC << endl;
}
void PL_itoa10 (int i , char* s)
{
char l_s[16];
int n = 0 , m = 0;
if ( i < 0 )
{
s[m++] = '-';
i=-i;
}
do
{
l_s[n++] = (char)('0'+(i%10));
i /= 10;
}
while ( i );
for ( --n ; n>=0 ; n--,m++ )
s[m] = l_s[n];
s[m]=0;
}
void PL_itoa16 (int i , char* s)
{
char l_s[16];
int n = 0 , m = 0;
if ( i < 0 )
{
s[m++] = '-';
i=-i;
}
do
{
if ( i%16 < 10 )
l_s[n++] = (char)('0'+(i%16));
else
l_s[n++] = (char)('a'+(i%16)-10);
i /= 16;
}
while ( i );
for ( --n ; n>=0 ; n--,m++ )
s[m] = l_s[n];
s[m]=0;
}
int PL_FileExists ( char *p_pPath )
{
FILE* l_pFich = NULL;
if (NULL == (l_pFich = fopen (p_pPath, "r")))
{
return (FALSE);
}
else
{
fclose (l_pFich);
return (TRUE);
}
}
答案 0 :(得分：1)
该代码使用多项式0x1021标记为CCITT标准CRC16非反射CRC。会产生那种类型的表。 试试这个：
static unsigned short crctable[256];
void make_crc_table( void )
{
int i, j;
unsigned long poly, c;
static const byte p[] = {0,5,12};
poly = 0L;
for ( i = 0; i < sizeof( p ) / sizeof( byte ); i++ )
{
poly |= 1L << p[i];
}
for ( i = 0; i < 256; i++ )
{
c = i << 8;
for ( j = 0; j < 8; j++ )
{
c = ( c & 0x8000 ) ? poly ^ ( c << 1 ) : ( c << 1 );
}
crctable[i] = (unsigned short) c;
}
}