MatrixSynapse/contrib/jitsimeetbridge/unjingle/strophe/base64.js

84 lines
2.5 KiB
JavaScript

// This code was written by Tyler Akins and has been placed in the
// public domain. It would be nice if you left this header intact.
// Base64 code from Tyler Akins -- http://rumkin.com
var Base64 = (function () {
var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
var obj = {
/**
* Encodes a string in base64
* @param {String} input The string to encode in base64.
*/
encode: function (input) {
var output = "";
var chr1, chr2, chr3;
var enc1, enc2, enc3, enc4;
var i = 0;
do {
chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++);
enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63;
if (isNaN(chr2)) {
enc3 = enc4 = 64;
} else if (isNaN(chr3)) {
enc4 = 64;
}
output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2) +
keyStr.charAt(enc3) + keyStr.charAt(enc4);
} while (i < input.length);
return output;
},
/**
* Decodes a base64 string.
* @param {String} input The string to decode.
*/
decode: function (input) {
var output = "";
var chr1, chr2, chr3;
var enc1, enc2, enc3, enc4;
var i = 0;
// remove all characters that are not A-Z, a-z, 0-9, +, /, or =
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, '');
do {
enc1 = keyStr.indexOf(input.charAt(i++));
enc2 = keyStr.indexOf(input.charAt(i++));
enc3 = keyStr.indexOf(input.charAt(i++));
enc4 = keyStr.indexOf(input.charAt(i++));
chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4;
output = output + String.fromCharCode(chr1);
if (enc3 != 64) {
output = output + String.fromCharCode(chr2);
}
if (enc4 != 64) {
output = output + String.fromCharCode(chr3);
}
} while (i < input.length);
return output;
}
};
return obj;
})();
// Nodify
exports.Base64 = Base64;