base64.js

base64.js

function base64(data) {
	var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	var o1, o2, o3, h1, h2, h3, h4, bits, i = 0, ac = 0, enc="", tmp_arr = [];

	if (!data) {
		return data;
	}

	data = utf8Encode(data);

	do { // pack three octets into four hexets
		o1 = data.charCodeAt(i++);
		o2 = data.charCodeAt(i++);
		o3 = data.charCodeAt(i++);

		bits = o1<<16 | o2<<8 | o3;

		h1 = bits>>18 & 0x3f;
		h2 = bits>>12 & 0x3f;
		h3 = bits>>6 & 0x3f;
		h4 = bits & 0x3f;

		// use hexets to index into b64, and append result to encoded string
		tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
	} while (i < data.length);

	enc = tmp_arr.join('');

	switch( data.length % 3 ){
		case 1:
			enc = enc.slice(0, -2) + '==';
			break;
		case 2:
			enc = enc.slice(0, -1) + '=';
			break;
	}

	return enc;

	function utf8Encode(string) {
		string = (string+'').replace(/\r\n/g, "\n").replace(/\r/g, "\n");

		var utftext = "",
			start,
			end;
		var stringl = 0,
			n;

		start = end = 0;
		stringl = string.length;

		for (n = 0; n < stringl; n++) {
			var c1 = string.charCodeAt(n);
			var enc = null;

			if (c1 < 128) {
				end++;
			} else if((c1 > 127) && (c1 < 2048)) {
				enc = String.fromCharCode((c1 >> 6) | 192, (c1 & 63) | 128);
			} else {
				enc = String.fromCharCode((c1 >> 12) | 224, ((c1 >> 6) & 63) | 128, (c1 & 63) | 128);
			}
			if (enc !== null) {
				if (end > start) {
					utftext += string.substring(start, end);
				}
				utftext += enc;
				start = end = n+1;
			}
		}

		if (end > start) {
			utftext += string.substring(start, string.length);
		}

		return utftext;
	}
}