exports.encode = function(input) {
var output = [];
var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
var i = 0, len = input.length, remainingBytes = len;

var isArray = utils.getTypeOf(input) !== "string";
while (i < input.length) {
remainingBytes = len - i;

if (!isArray) {
chr1 = input.charCodeAt(i++);
chr2 = i < len ? input.charCodeAt(i++) : 0;
chr3 = i < len ? input.charCodeAt(i++) : 0;
} else {
chr1 = input[i++];
chr2 = i < len ? input[i++] : 0;
chr3 = i < len ? input[i++] : 0;
}

enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = remainingBytes > 1 ? (((chr2 & 15) << 2) | (chr3 >> 6)) : 64;
enc4 = remainingBytes > 2 ? (chr3 & 63) : 64;

output.push(_keyStr.charAt(enc1) + _keyStr.charAt(enc2) + _keyStr.charAt(enc3) + _keyStr.charAt(enc4));

}

return output.join("");
};