// Process message into chunks
function chunkMessage( str )
{
	nblk = ((str.length + 8) >> 6) + 1;
	blks = new Array(nblk * 16);

	for(i = 0; i < nblk * 16; i++)
	{
		blks[i] = 0;
	}
	for(i = 0; i < str.length; i++)
	{
		blks[i >> 2] |= str.charCodeAt(i) << ((i % 4) * 8);
	}

	blks[i >> 2] |= 0x80 << ((i % 4) * 8);
	blks[nblk * 16 - 2] = str.length * 8;

	return blks;
}