align(4);
        int i = index;
        int len = s.length();
        Encdec.enc_uint32le(len + 1, buf, i); i += 4;
        Encdec.enc_uint32le(0, buf, i); i += 4;
        Encdec.enc_uint32le(len + 1, buf, i); i += 4;
        try {
            System.arraycopy(s.getBytes("UTF-16LE"), 0, buf, i, len * 2);
        } catch( UnsupportedEncodingException uee ) {
        }
        i += len * 2;
        buf[i++] = (byte)'\0';

        align(4);
        int i = this.index;
        int len = s.length();
        Encdec.enc_uint32le(len + 1, this.buf, i);
        i += 4;
        Encdec.enc_uint32le(0, this.buf, i);
        i += 4;
        Encdec.enc_uint32le(len + 1, this.buf, i);
        i += 4;
        System.arraycopy(Strings.getUNIBytes(s), 0, this.buf, i, len * 2);
        i += len * 2;

        byte[] temp = new byte[28 + avPairsLength + 4];

        Encdec.enc_uint32le(0x00000101, temp, 0); // Header
        Encdec.enc_uint32le(0x00000000, temp, 4); // Reserved
        Encdec.enc_uint64le(nanos1601, temp, 8);
        System.arraycopy(clientChallenge, 0, temp, 16, 8);
        Encdec.enc_uint32le(0x00000000, temp, 24); // Unknown
        if ( avPairs != null )