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base64.js
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base64.js
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/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/* Base64 class: Base 64 encoding / decoding (c) Chris Veness 2002-2010 */
/* note: depends on Utf8 class */
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
var Base64 = {}; // Base64 namespace
Base64.code = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
/**
* Encode string into Base64, as defined by RFC 4648 [http://tools.ietf.org/html/rfc4648]
* (instance method extending String object). As per RFC 4648, no newlines are added.
*
* @param {String} str The string to be encoded as base-64
* @param {Boolean} [utf8encode=false] Flag to indicate whether str is Unicode string to be encoded
* to UTF8 before conversion to base64; otherwise string is assumed to be 8-bit characters
* @returns {String} Base64-encoded string
*/
Base64.encode = function(str, utf8encode) { // http://tools.ietf.org/html/rfc4648
utf8encode = (typeof utf8encode == 'undefined') ? false : utf8encode;
var o1, o2, o3, bits, h1, h2, h3, h4, e=[], pad = '', c, plain, coded;
var b64 = Base64.code;
plain = utf8encode ? str.encodeUTF8() : str;
c = plain.length % 3; // pad string to length of multiple of 3
if (c > 0) { while (c++ < 3) { pad += '='; plain += '\0'; } }
// note: doing padding here saves us doing special-case packing for trailing 1 or 2 chars
for (c=0; c<plain.length; c+=3) { // pack three octets into four hexets
o1 = plain.charCodeAt(c);
o2 = plain.charCodeAt(c+1);
o3 = plain.charCodeAt(c+2);
bits = o1<<16 | o2<<8 | o3;
h1 = bits>>18 & 0x3f;
h2 = bits>>12 & 0x3f;
h3 = bits>>6 & 0x3f;
h4 = bits & 0x3f;
// use hextets to index into code string
e[c/3] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
}
coded = e.join(''); // join() is far faster than repeated string concatenation in IE
// replace 'A's from padded nulls with '='s
coded = coded.slice(0, coded.length-pad.length) + pad;
return coded;
}
/**
* Decode string from Base64, as defined by RFC 4648 [http://tools.ietf.org/html/rfc4648]
* (instance method extending String object). As per RFC 4648, newlines are not catered for.
*
* @param {String} str The string to be decoded from base-64
* @param {Boolean} [utf8decode=false] Flag to indicate whether str is Unicode string to be decoded
* from UTF8 after conversion from base64
* @returns {String} decoded string
*/
Base64.decode = function(str, utf8decode) {
utf8decode = (typeof utf8decode == 'undefined') ? false : utf8decode;
var o1, o2, o3, h1, h2, h3, h4, bits, d=[], plain, coded;
var b64 = Base64.code;
coded = utf8decode ? str.decodeUTF8() : str;
for (var c=0; c<coded.length; c+=4) { // unpack four hexets into three octets
h1 = b64.indexOf(coded.charAt(c));
h2 = b64.indexOf(coded.charAt(c+1));
h3 = b64.indexOf(coded.charAt(c+2));
h4 = b64.indexOf(coded.charAt(c+3));
bits = h1<<18 | h2<<12 | h3<<6 | h4;
o1 = bits>>>16 & 0xff;
o2 = bits>>>8 & 0xff;
o3 = bits & 0xff;
d[c/4] = String.fromCharCode(o1, o2, o3);
// check for padding
if (h4 == 0x40) d[c/4] = String.fromCharCode(o1, o2);
if (h3 == 0x40) d[c/4] = String.fromCharCode(o1);
}
plain = d.join(''); // join() is far faster than repeated string concatenation in IE
return utf8decode ? plain.decodeUTF8() : plain;
}