blizzard.c

几种c语言的hash算法

#include <stdio.h>


/*crytTable[]里面保存的是HashString函数里面将会用到的一些数据，在prepareCryptTable
*函数里面初始化*/
unsigned long cryptTable[0x500];


/***********************************************************
*以下的函数生成一个长度为0x500（合10进制数：1280）的cryptTable[0x500]
*
*
***********************************************************/
void prepareCryptTable()
{
    unsigned long seed = 0x00100001, index1 = 0, index2 = 0, i;

    for( index1 = 0; index1 < 0x100; index1++ )
    {
        for( index2 = index1, i = 0; i < 5; i++, index2 += 0x100 )
        {
            unsigned long temp1, temp2;

            seed = (seed * 125 + 3) % 0x2AAAAB;
            temp1 = (seed & 0xFFFF) << 0x10;

            seed = (seed * 125 + 3) % 0x2AAAAB;
            temp2 = (seed & 0xFFFF);

            cryptTable[index2] = ( temp1 | temp2 );
       }
   }
}


/***********************************************************
*以下函数计算lpszFileName 字符串的hash值，其中dwHashType 为hash的类型，
*在下面GetHashTablePos函数里面调用本函数，其可以取的值为0、1、2；该函数
*返回lpszFileName 字符串的hash值；
***********************************************************/
unsigned long HashString( char *lpszFileName, unsigned long dwHashType )
{
    unsigned char *key = (unsigned char *)lpszFileName;
unsigned long seed1 = 0x7FED7FED;
unsigned long seed2 = 0xEEEEEEEE;
    int ch;

    while( *key != 0 )
    {
        ch = toupper(*key++);

        seed1 = cryptTable[(dwHashType << 8) + ch] ^ (seed1 + seed2);
        seed2 = ch + seed1 + seed2 + (seed2 << 5) + 3;
    }
    return seed1;
}

/***********************************************************
*在main中测试argv[1]的三个hash值：
* ./hash "arr\units.dat"
* ./hash "unit\neutral\acritter.grp"
***********************************************************/
int main( int argc, char **argv )
{
    unsigned long ulHashValue;
    int i = 0;

    if ( argc != 2 )
    {
        printf("please input two arguments\n");
        return -1;
    }

     /*初始化数组：crytTable[0x500]*/
     prepareCryptTable();

     /*打印数组crytTable[0x500]里面的值*/
     for ( ; i < 0x500; i++ )
     {
         if ( i % 10 == 0 )
         {
             printf("\n");
         }

         printf("%-12X", cryptTable[i] );
     }

     ulHashValue = HashString( argv[1], 0 );
     printf("\n----%X ----\n", ulHashValue );

     ulHashValue = HashString( argv[1], 1 );
     printf("----%X ----\n", ulHashValue );

     ulHashValue = HashString( argv[1], 2 );
     printf("----%X ----\n", ulHashValue );

     return 0;
}