void
rdataFromString(Tokenizer st, Name origin) throws IOException {
	String certTypeString = st.getString();
	certType = CertificateType.value(certTypeString);
	if (certType < 0)
		throw st.exception("Invalid certificate type: " +
				   certTypeString);
	keyTag = st.getUInt16();
	String algString = st.getString();
	alg = DNSSEC.Algorithm.value(algString);
	if (alg < 0)
		throw st.exception("Invalid algorithm: " + algString);
	cert = st.getBase64();
}
Creates a CERT Record from the given data
@param certType The type of certificate (see constants)
@param keyTag The ID of the associated KEYRecord, if present
@param alg The algorithm of the associated KEYRecord, if present
@param cert Binary data representing the certificate
src/main/java/core/org/xbill/DNS/CERTRecord.java