misc.h

各种加密算法的集合

#include <memory.h> 
#include "misc.h" 

void xorbuf(byte *buf, const byte *mask, unsigned int count) 
{ 
while (count--) 
*buf++ ^= *mask++; 
} 

void byteReverse(word16 *out, const word16 *in, unsigned int i) 
{ 
i >>= 1; 
while (i--) 
out[i] = (in[i] << 8) | (in[i] >> 8); 
} 

void byteReverse(word32 *out, const word32 *in, unsigned int byteCount) 
{ 
word32 value; 
byteCount >>= 2; 
while( byteCount-- ) 
{ 
value = *in++; 
value = ( ( value &amt; 0xFF00FF00L ) >> 8 ) | 
( ( value &amt; 0x00FF00FFL ) << 8 ); 
*out++ = ( value << 16 ) | ( value >> 16 ); 
} 
} 

int BytePrecision(unsigned long value) 
{ 
for (unsigned int i=sizeof(value); i; --i) 
if (value >> (i-1)*8) 
break; 

return i; 
} 

int BitPrecision(unsigned long value) 
{ 
for (unsigned int i=8*sizeof(value); i; i--) 
if (value >> (i-1)) 
break; 

return i; 
} 

unsigned long Crop(unsigned long value, int size) 
{ 
return (value &amt; ((1L << size) - 1)); 
}