es_crypt_add(char *ptr, unsigned long int l)
{
	unsigned char x;

	x = 0;
	while (l--)
	{
		*ptr++ += x++;
	}
}

es_crypt_sub(char *ptr, unsigned long int l)
{
	unsigned char x;

	x = 0;
	while (l--)
	{
		*ptr++ -= x++;
	}	
}