Refactor Needles Interfaces and Rename "process" to "backend"

Reason:
- Interfaces with a single method can be replaced with
  interfaces from java.util.function.
- Less interfaces = less code = less maintenance!
- Spring can inject beans by name so we name dependencies correctly
  to prevent ambiguity.

Others:
- Rename process to backend since backend gives a better description
  of its components.

4 files changed, 392 insertions, 0 deletions

diff --git a/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java b/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java
new file mode 100644
index 0000000..06eba80
--- /dev/null
+++ b/src/main/java/at/gv/egiz/moazs/backend/DeliveryRequestBackend.java
@@ -0,0 +1,112 @@
+package at.gv.egiz.moazs.backend;
+
+
+import at.gv.egiz.moazs.MoaZSException;
+import at.gv.egiz.moazs.client.ClientFactory;
+import at.gv.egiz.moazs.client.TnvzHelper;
+import at.gv.egiz.moazs.repository.DeliveryRepository;
+import at.gv.egiz.moazs.scheme.Mzs2MsgConverter;
+import at.gv.egiz.moazs.scheme.RequestStatusResponse;
+import at.gv.zustellung.app2mzs.xsd.DeliveryRequestType;
+import at.gv.zustellung.msg.xsd.App2ZusePort;
+import at.gv.zustellung.tnvz.xsd.TNVZServicePort;
+import org.apache.log4j.Logger;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Profile;
+import org.springframework.stereotype.Component;
+
+import java.util.function.Consumer;
+
+import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
+import static at.gv.egiz.moazs.scheme.RequestStatusResponse.generateErrorFromException;
+import static java.lang.String.format;
+
+@Component
+@Profile("!cluster")
+public class DeliveryRequestBackend implements Consumer<String> {
+
+    private static final Logger log = Logger.getLogger(DeliveryRequestBackend.class);
+    private static final String MZS_PIPELINE_ERROR_MSG =
+            "An error occured while processing the DeliveryRequest with AppDeliveryID=%s. ";
+
+    private final DeliveryRepository repository;
+    private final TnvzHelper tnvzHelper;
+    private final Mzs2MsgConverter converter;
+    private final ClientFactory clientFactory;
+    private final Consumer<byte[]> signatureVerifier;
+
+    @Autowired
+    public DeliveryRequestBackend(DeliveryRepository repository,
+                                  TnvzHelper tnvzHelper,
+                                  Mzs2MsgConverter converter,
+                                  ClientFactory clientFactory,
+                                  Consumer<byte[]> signatureVerifier) {
+        this.repository = repository;
+        this.tnvzHelper = tnvzHelper;
+        this.converter = converter;
+        this.clientFactory = clientFactory;
+        this.signatureVerifier = signatureVerifier;
+    }
+
+    /**
+     * Performs all {@code DeliveryRequest}'s Back-End Tasks.
+     *
+     * Fetches {@code DeliveryRequest} referred by appDeliveryID from
+     * {@code DeliveryRepository}, makes sure that all necessary
+     * tasks (query tnvz, query msg, accept status) are executed and
+     * stores the response back to {@code DeliveryRepository}.
+     * @param appDeliveryID
+     */
+    @Override
+    public void accept(String appDeliveryID) {
+
+        var exceptionBuilder = moaZSExceptionBuilder();
+
+        try {
+            var mzsRequest = repository.retrieveDeliveryRequest(appDeliveryID).orElseThrow();
+            exceptionBuilder.withDeliverySystem(mzsRequest);
+
+            at.gv.zustellung.msg.xsd.DeliveryRequestType msgRequest = buildMsgRequest(mzsRequest, exceptionBuilder);
+
+            var msgClientParams = mzsRequest.getConfig().getMSGClient();
+            App2ZusePort client = clientFactory.create(msgClientParams, App2ZusePort.class);
+            var status = client.delivery(msgRequest);
+
+            var response = new RequestStatusResponse(status);
+            exceptionBuilder.withAllParametersInAnswer(response.getAnswer());
+
+            verifySignedStatus(response.getResponseID(), appDeliveryID, exceptionBuilder);
+            repository.store(response);
+
+        } catch (MoaZSException exception) {
+            log.error(format(MZS_PIPELINE_ERROR_MSG, appDeliveryID), exception);
+            var errorResponse = generateErrorFromException(exception);
+            repository.store(errorResponse);
+        }
+    }
+
+    private void verifySignedStatus(String responseID, String appDeliveryID, MoaZSException.Builder exceptionBuilder) throws MoaZSException {
+        try {
+            var signedStatus = repository.retrieveBinaryResponse(responseID).get();
+            signatureVerifier.accept(signedStatus);
+        } catch (MoaZSException ex) {
+            throw exceptionBuilder.withMessage(format(MsgResponseBackend.MOASP_SIGNATURE_INVALID_ERROR_MSG, appDeliveryID))
+                    .withErrorCode(MoaZSException.ERROR_MOASP_SIGNATURE_INVALID)
+                    .withCause(ex)
+                    .build();
+        }
+    }
+
+    private at.gv.zustellung.msg.xsd.DeliveryRequestType buildMsgRequest(DeliveryRequestType mzsRequest,
+                                                                         MoaZSException.Builder exceptionBuilder) throws MoaZSException {
+        if (mzsRequest.getConfig().isPerformQueryPersonRequest()) {
+            var tnvzClientParams = mzsRequest.getConfig().getTNVZClient();
+            TNVZServicePort tvnzPort = clientFactory.create(tnvzClientParams, TNVZServicePort.class);
+            var identification = tnvzHelper.performQueryPersonRequest(mzsRequest, tvnzPort, exceptionBuilder);
+            return converter.convert(mzsRequest, identification);
+        } else {
+            return converter.convert(mzsRequest);
+        }
+    }
+
+}
diff --git a/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java b/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
new file mode 100644
index 0000000..414c2dc
--- /dev/null
+++ b/src/main/java/at/gv/egiz/moazs/backend/MsgResponseBackend.java
@@ -0,0 +1,75 @@
+package at.gv.egiz.moazs.backend;
+
+import at.gv.egiz.moazs.MoaZSException;
+import at.gv.egiz.moazs.repository.DeliveryRepository;
+import at.gv.egiz.moazs.scheme.MsgResponse;
+import at.gv.egiz.moazs.service.MsgService;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
+import static java.lang.String.format;
+import static java.util.concurrent.CompletableFuture.supplyAsync;
+
+@Component
+public class MsgResponseBackend implements Consumer<String> {
+
+    private static final Logger log = LoggerFactory.getLogger(MsgService.class);
+
+    public static final String MOASP_SIGNATURE_INVALID_ERROR_MSG = "Signature of Msg Response " +
+            "with AppDeliveryID=%s is not valid.";
+
+    private final DeliveryRepository repository;
+    private final Consumer<byte[]> signatureVerifier;
+    private final Function<MsgResponse, CompletableFuture<Void>> sink;
+
+    @Autowired
+    public MsgResponseBackend(DeliveryRepository repository,
+                              Consumer<byte[]> signatureVerifier,
+                              Function<MsgResponse, CompletableFuture<Void>> sink) {
+        this.repository = repository;
+        this.signatureVerifier = signatureVerifier;
+        this.sink = sink;
+    }
+
+    /**
+     * Performs all {@code MsgResponse}'s Back-End Tasks, such as verifying
+     * its signature and archiving the response.
+     *
+     * @param responseID refers to MsgResponse Object.
+     */
+    @Override
+    public void accept(String responseID) {
+        supplyAsync(() -> verify(responseID)).thenAcceptAsync(sink::apply);
+    }
+
+    public MsgResponse verify(String responseID) {
+
+        var response = repository.retrieveResponse(responseID).get();
+        var builder = moaZSExceptionBuilder().withAllParametersInAnswer(response.getAnswer());
+
+        var binaryResponse = repository.retrieveBinaryResponse(responseID).get();
+
+        try {
+            signatureVerifier.accept(binaryResponse);
+            return response;
+        } catch (MoaZSException ex) {
+            log.error(ex.getMessage(), ex);
+            var wrappingEx = builder
+                    .withMessage(format(MOASP_SIGNATURE_INVALID_ERROR_MSG, response.getAppDeliveryID()))
+                    .withErrorCode(MoaZSException.ERROR_MOASP_SIGNATURE_INVALID)
+                    .withCause(ex)
+                    .build();
+
+            return response.generateError(wrappingEx);
+        }
+
+    }
+
+}
diff --git a/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java b/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java
new file mode 100644
index 0000000..02771a9
--- /dev/null
+++ b/src/main/java/at/gv/egiz/moazs/backend/SaveResponseToFileSink.java
@@ -0,0 +1,89 @@
+package at.gv.egiz.moazs.backend;
+
+import at.gv.egiz.moazs.repository.DeliveryRepository;
+import at.gv.egiz.moazs.scheme.Marshaller;
+import at.gv.egiz.moazs.scheme.MsgResponse;
+import org.apache.commons.io.FileUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Function;
+
+import static at.gv.egiz.moazs.MoaZSException.moaZSException;
+import static java.lang.String.format;
+import static java.util.concurrent.CompletableFuture.allOf;
+import static java.util.concurrent.CompletableFuture.supplyAsync;
+
+@Component
+public class SaveResponseToFileSink implements Function<MsgResponse, CompletableFuture<Void>> {
+
+    private static final Logger log = LoggerFactory.getLogger(SaveResponseToFileSink.class);
+    private static final String SAVING_FAILED_MSG = "Could not save response with AppDeliveryId=%s.";
+
+    private final SimpleDateFormat isoFormatter;
+    private final Marshaller msgMarshaller;
+    private final DeliveryRepository repository;
+    private final String root;
+
+    @Autowired
+    public SaveResponseToFileSink(Marshaller msgMarshaller, DeliveryRepository repository, String root) {
+        this.msgMarshaller = msgMarshaller;
+        this.repository = repository;
+        this.root = root;
+        this.isoFormatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
+    }
+
+    @Override
+    public CompletableFuture<Void> apply(MsgResponse response) {
+
+        var responseID = response.getResponseID();
+
+        var responsePath = generatePath(responseID, "xml");
+        var storeResponseToFileSystemFuture = supplyAsync(() -> msgMarshaller.marshallXml(response.getResponse()))
+                .thenApply(responseString -> responseString.getBytes(StandardCharsets.UTF_8))
+                .thenAccept(responseByteArray -> storeToFile(responsePath, responseByteArray))
+                .exceptionally(ex -> logException(ex, responseID));
+
+        var binaryResponsePath = generatePath(responseID, "binary.xml");
+        var storeBinaryResponseToFileSystemFuture = supplyAsync(() -> repository.retrieveBinaryResponse(responseID).get())
+                .thenAccept(binaryResponseByteArray -> storeToFile(binaryResponsePath, binaryResponseByteArray))
+                .exceptionally(ex -> logException(ex, responseID));
+
+        return allOf(storeResponseToFileSystemFuture, storeBinaryResponseToFileSystemFuture);
+
+    }
+
+    private String generatePath(String id, String suffix) {
+        var folder = sanitizeFileString(id);
+        var nowInIso8601 = isoFormatter.format(new Date());
+        return format("%s/%s/%s.%s", root, folder, nowInIso8601,  suffix);
+    }
+
+    private String sanitizeFileString(String fileString) {
+        return fileString.replaceAll("[^a-zA-Z0-9\\._\\-]", "");
+    }
+
+    private Void logException(Throwable ex, String appDeliveryID) {
+        if(log.isErrorEnabled()) {
+            log.error(format(SAVING_FAILED_MSG, appDeliveryID), ex);
+        }
+        return null;
+    }
+
+    private void storeToFile(String path, byte[] content) {
+        try {
+            FileUtils.writeByteArrayToFile(new File(path), content);
+        } catch (IOException e) {
+            throw moaZSException(e.getMessage(), e);
+        }
+    }
+
+}
diff --git a/src/main/java/at/gv/egiz/moazs/backend/SignatureVerifier.java b/src/main/java/at/gv/egiz/moazs/backend/SignatureVerifier.java
new file mode 100644
index 0000000..e9c5387
--- /dev/null
+++ b/src/main/java/at/gv/egiz/moazs/backend/SignatureVerifier.java
@@ -0,0 +1,116 @@
+package at.gv.egiz.moazs.backend;
+
+import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.api.ISignatureVerificationService;
+import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.api.data.IXMLSignatureVerificationResponse;
+import at.gv.egiz.eid.authhandler.modules.sigverify.moasig.exceptions.MOASigServiceException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.function.Consumer;
+
+import static at.gv.egiz.moazs.MoaZSException.moaZSException;
+import static at.gv.egiz.moazs.MoaZSException.moaZSExceptionBuilder;
+import static java.lang.String.format;
+
+public class SignatureVerifier implements Consumer<byte[]> {
+
+    private static final Logger log = LoggerFactory.getLogger(SignatureVerifier.class);
+    private static final int OK_CODE = 0;
+
+    private final ISignatureVerificationService service;
+    private final String trustProfile;
+    private final boolean isManifestCheckActive;
+
+    public SignatureVerifier(ISignatureVerificationService service,
+                                    String trustProfile, boolean isManifestCheckActive) {
+        this.service = service;
+        this.trustProfile = trustProfile;
+        this.isManifestCheckActive = isManifestCheckActive;
+    }
+
+    /**
+     * Verifies the signature of a signed XML document. Throws a at.gv.egiz.moazs.MoaZSException exception
+     * if the validation fails.
+     * @param signedXMLdocument
+     * @throws at.gv.egiz.moazs.MoaZSException
+     */
+    @Override
+    public void accept(byte[] signedXMLdocument) {
+
+        try {
+            var response = service.verifyXMLSignature(signedXMLdocument, trustProfile);
+
+            if (log.isDebugEnabled()) {
+                print(response);
+            }
+
+            if (response == null) {
+                throw moaZSException("MOA SPSS could not find the signature. ");
+            }
+
+            var builder = new StringBuilder();
+
+            if (response.getSignatureCheckCode() != OK_CODE) {
+                builder.append(format("Signature is not valid; SignatureCheckCode was %d. ",
+                        response.getSignatureCheckCode()));
+            }
+
+            if (response.getCertificateCheckCode() != OK_CODE) {
+                builder.append(format("Certificate chain is not valid; CertificateCheckCode was %d. ",
+                        response.getCertificateCheckCode()));
+            }
+
+            if (response.getSignatureManifestCheckCode() != OK_CODE) {
+                var signatureManifestErrorMsg = format("Signature Manifest is not valid; " +
+                        "SignatureManifestCheckCode was %d. ", response.getSignatureManifestCheckCode());
+                if (isManifestCheckActive) {
+                    builder.append(signatureManifestErrorMsg);
+                } else {
+                    log.warn(signatureManifestErrorMsg);
+                }
+            }
+
+            if (response.isXmlDSIGManigest() && response.getXmlDSIGManifestCheckCode() != OK_CODE) {
+                var xmlDSIGManifestErrorMsg = format("XmlDSIGManifest Manifest is not valid; " +
+                        "XmlDSIGManifest was %d. ", response.getXmlDSIGManifestCheckCode());
+                if (isManifestCheckActive) {
+                    builder.append(xmlDSIGManifestErrorMsg);
+                } else {
+                    log.warn(xmlDSIGManifestErrorMsg);
+                }
+            }
+
+            var msg = builder.toString();
+
+            if(msg.length() > 0) {
+                throw moaZSException(msg);
+            }
+
+        } catch (MOASigServiceException e) {
+            throw moaZSExceptionBuilder("Could not accept the XML signature.")
+                    .withCause(e)
+                    .build();
+        }
+
+    }
+
+    private void print(IXMLSignatureVerificationResponse response) {
+        log.debug("Response:");
+
+        if (response == null) {
+            log.debug("null");
+            return;
+        }
+
+        log.debug("  XmlDsigSubjectName: {}", response.getXmlDsigSubjectName());
+        log.debug("  SignatureManifestCheckCode: {}", response.getSignatureManifestCheckCode());
+        log.debug("  XmlDSIGManifestCheckCode: {}", response.getXmlDSIGManifestCheckCode());
+        log.debug("  CertificateCheckCode: {}", response.getCertificateCheckCode());
+        log.debug("  SignatureCheckCode: {}", response.getSignatureCheckCode());
+        log.debug("  SigningDateTime: {}", response.getSigningDateTime());
+        log.debug("  isXmlDSIGManigest: {}", response.isXmlDSIGManigest());
+        log.debug("  isPublicAuthority: {}", response.isPublicAuthority());
+        log.debug("  isQualifiedCertificate: {}", response.isQualifiedCertificate());
+        log.debug("  getPublicAuthorityCode: {}", response.getPublicAuthorityCode());
+    }
+}