protected Transformer buildTransformerChain()

in src/main/java/org/apache/xml/security/stax/impl/processor/input/AbstractSignatureReferenceVerifyInputProcessor.java [326:394]
56 lines of code
9 McCabe index (conditional complexity)

    protected Transformer buildTransformerChain(ReferenceType referenceType, OutputStream outputStream,
                                                InputProcessorChain inputProcessorChain,
                                                InternalSignatureReferenceVerifier internalSignatureReferenceVerifier)
            throws XMLSecurityException {

        // If no Transforms then just default to an Inclusive without comments transform
        if (referenceType.getTransforms() == null || referenceType.getTransforms().getTransform().isEmpty()) {

            AlgorithmSuiteSecurityEvent algorithmSuiteSecurityEvent = new AlgorithmSuiteSecurityEvent();
            algorithmSuiteSecurityEvent.setAlgorithmURI(XMLSecurityConstants.NS_C14N_OMIT_COMMENTS);
            algorithmSuiteSecurityEvent.setAlgorithmUsage(XMLSecurityConstants.SigTransform);
            algorithmSuiteSecurityEvent.setCorrelationID(referenceType.getId());
            inputProcessorChain.getSecurityContext().registerSecurityEvent(algorithmSuiteSecurityEvent);

            Transformer transformer = new Canonicalizer20010315_OmitCommentsTransformer();
            transformer.setOutputStream(outputStream);
            return transformer;
        }

        List<TransformType> transformTypeList = referenceType.getTransforms().getTransform();

        if (transformTypeList.size() == 1 &&
                XMLSecurityConstants.NS_XMLDSIG_ENVELOPED_SIGNATURE.equals(transformTypeList.get(0).getAlgorithm())) {
            TransformType transformType = new TransformType();
            transformType.setAlgorithm(XMLSecurityConstants.NS_C14N_OMIT_COMMENTS);
            transformTypeList.add(transformType);
        }

        if (transformTypeList.size() > maximumAllowedTransformsPerReference) {
            throw new XMLSecurityException(
                    "secureProcessing.MaximumAllowedTransformsPerReference",
                    new Object[] {transformTypeList.size(), maximumAllowedTransformsPerReference});
        }

        Transformer parentTransformer = null;
        for (int i = transformTypeList.size() - 1; i >= 0; i--) {
            TransformType transformType = transformTypeList.get(i);

            String algorithm = transformType.getAlgorithm();

            AlgorithmSuiteSecurityEvent algorithmSuiteSecurityEvent = new AlgorithmSuiteSecurityEvent();
            algorithmSuiteSecurityEvent.setAlgorithmURI(algorithm);
            algorithmSuiteSecurityEvent.setAlgorithmUsage(XMLSecurityConstants.SigTransform);
            algorithmSuiteSecurityEvent.setCorrelationID(referenceType.getId());
            inputProcessorChain.getSecurityContext().registerSecurityEvent(algorithmSuiteSecurityEvent);

            InclusiveNamespaces inclusiveNamespacesType =
                    XMLSecurityUtils.getQNameType(transformType.getContent(),
                            XMLSecurityConstants.TAG_c14nExcl_InclusiveNamespaces);

            Map<String, Object> transformerProperties = null;
            if (inclusiveNamespacesType != null) {
                transformerProperties = new HashMap<>();
                transformerProperties.put(
                        Canonicalizer20010315_Excl.INCLUSIVE_NAMESPACES_PREFIX_LIST,
                        inclusiveNamespacesType.getPrefixList());
            }

            if (parentTransformer != null) {
                parentTransformer = XMLSecurityUtils.getTransformer(
                        parentTransformer, null, transformerProperties, algorithm, XMLSecurityConstants.DIRECTION.IN);
            } else {
                parentTransformer =
                        XMLSecurityUtils.getTransformer(
                                null, outputStream, transformerProperties, algorithm, XMLSecurityConstants.DIRECTION.IN);
            }
        }
        return parentTransformer;
    }