try {
SignatureAlgorithm signatureAlgorithm =
SignatureAlgorithmFactory.getInstance().getSignatureAlgorithm(
algorithmURI);
signatureAlgorithm.engineInitVerify(verifyKey);
signerOutputStream = new SignerOutputStream(signatureAlgorithm);
bufferedSignerOutputStream = new UnsynchronizedBufferedOutputStream(signerOutputStream);
final CanonicalizationMethodType canonicalizationMethodType =
signatureType.getSignedInfo().getCanonicalizationMethod();