public void encodeTBS(OutputStream output, CertificateEntry certEntry)
            throws SerializationException {
        Serialization.writeNumber(output, version.value(), Constants.VERSION_LENGTH);
        Serialization.writeNumber(output, SignatureType.CERTIFICATE_TIMESTAMP.value(),
                Constants.SIGNATURE_TYPE_LENGTH);
        Serialization.writeNumber(output, timestamp, Constants.TIMESTAMP_LENGTH);
        certEntry.encode(output);
        Serialization.writeVariableBytes(output, extensions, Constants.EXTENSIONS_LENGTH_BYTES);
    }
TLS encode the signed part of the SCT, as described by RFC6962 section 3.2.
common/src/main/java/org/conscrypt/ct/SignedCertificateTimestamp.java