m.init(key);
m.update(t[1].getBytes());
String part1Expect = BASE64Encoder.encode(m.doFinal());
BASE64Decoder decode = new BASE64Decoder();
String s = new String(decode.decodeBuffer(t[1]));
if (part1.equals(part1Expect)) {
return ts(s);
} else {
return null;
}