How to remove the encryption in gunz source or change

void ConvertChar(char* pData,int _size)
{
	if(!pData) return;

	WORD w;
	BYTE b,bh;

	for(int i=0;i<_size;i++) {
  b = *pData ^ 0xFF;
  w = b<<3;
  bh = (w&0xff00)>>8;
  b = w&0xff;
  *pData = BYTE( b | bh );
  pData++;

	}
}

void RecoveryChar(char* pData,int _size)
{
	if(!pData) return;

	BYTE b,bh,d;

	for(int i=0;i<_size;i++) {

  b = *pData;
  bh = b&0x07;
  d = (bh<<5)|(b>>3);
  *pData = d ^ 0xff;
  pData++;
	}
}