NxTIC/public_html/js/lib/crc32.js

var makeCRCTable = function(){
	var c;
	var crcTable = [];
	for(var n =0; n < 256; n++){
		c = n;
		for(var k =0; k < 8; k++){
			c = ((c&1) ? (0xEDB88320 ^ (c >>> 1)) : (c >>> 1));
		}
		crcTable[n] = c;
	}
	return crcTable;
};

var crc32 = function(str) {
	var crcTable = window.crcTable || (window.crcTable = makeCRCTable());
	var crc = 0 ^ (-1);

	for (var i = 0; i < str.length; i++ ) {
		crc = (crc >>> 8) ^ crcTable[(crc ^ str.charCodeAt(i)) & 0xFF];
	}

	return (crc ^ (-1)) >>> 0;
};