1 files changed, 91 insertions, 0 deletions
diff --git a/csarvalidation/src/main/java/org/onap/cvc/csar/security/CmsSignatureDataFactory.java b/csarvalidation/src/main/java/org/onap/cvc/csar/security/CmsSignatureDataFactory.java
new file mode 100644
index 0000000..2744bc6
--- /dev/null
+++ b/csarvalidation/src/main/java/org/onap/cvc/csar/security/CmsSignatureDataFactory.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2020 Nokia
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.onap.cvc.csar.security;
+
+import org.bouncycastle.asn1.cms.ContentInfo;
+import org.bouncycastle.cert.X509CertificateHolder;
+import org.bouncycastle.cms.CMSException;
+import org.bouncycastle.cms.CMSProcessableByteArray;
+import org.bouncycastle.cms.CMSSignedData;
+import org.bouncycastle.cms.CMSTypedData;
+import org.bouncycastle.cms.SignerInformation;
+import org.bouncycastle.openssl.PEMParser;
+import org.bouncycastle.util.Store;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.Charset;
+import java.util.Collection;
+import java.util.Optional;
+
+public class CmsSignatureDataFactory {
+
+    public CmsSignatureData createForFirstSigner(final byte[] cmsSignature, final byte[] fileContent)
+    throws CmsSignatureLoadingException{
+
+        try (ByteArrayInputStream cmsSignatureStream = new ByteArrayInputStream(cmsSignature)) {
+            CMSSignedData signedData = getCMSSignedData(fileContent, cmsSignatureStream);
+            Collection<SignerInformation> signers = signedData.getSignerInfos().getSigners();
+            Store<X509CertificateHolder> certificates = signedData.getCertificates();
+            SignerInformation firstSigner = getFirstSigner(signers);
+            CmsSignatureData signatureData = new CmsSignatureData(firstSigner);
+            getFirstSignerCertificate(certificates, firstSigner).ifPresent(
+                signatureData::loadCertificate
+            );
+            return signatureData;
+        } catch (CertificateLoadingException | IOException | CMSException e) {
+            throw new CmsSignatureLoadingException("Unexpected error occurred during signature validation!", e);
+        }
+    }
+
+    private SignerInformation getFirstSigner(Collection<SignerInformation> signers) {
+        return signers.iterator().next();
+    }
+
+    private Optional<byte[]> getFirstSignerCertificate(
+        Store<X509CertificateHolder> certificates,
+        SignerInformation firstSigner)
+        throws IOException {
+        Collection<X509CertificateHolder> firstSignerCertificates = certificates.getMatches(firstSigner.getSID());
+        Optional<byte[]> cert;
+        if (!firstSignerCertificates.isEmpty()) {
+            X509CertificateHolder firstSignerFirstCertificate = firstSignerCertificates.iterator().next();
+            cert = Optional.of(firstSignerFirstCertificate.getEncoded());
+        } else {
+            cert = Optional.empty();
+        }
+        return cert;
+    }
+
+
+    private CMSSignedData getCMSSignedData(byte[] innerPackageFileCSAR, ByteArrayInputStream signatureStream) throws IOException, CmsSignatureLoadingException, CMSException {
+        ContentInfo signature = produceSignature(signatureStream);
+        CMSTypedData signedContent = new CMSProcessableByteArray(innerPackageFileCSAR);
+        return new CMSSignedData(signedContent, signature);
+    }
+
+    private ContentInfo produceSignature(ByteArrayInputStream signatureStream) throws IOException, CmsSignatureLoadingException {
+        Object parsedObject = new PEMParser(new InputStreamReader(signatureStream, Charset.defaultCharset())).readObject();
+        if (!(parsedObject instanceof ContentInfo)) {
+            throw new CmsSignatureLoadingException("Signature is not recognized!");
+        }
+        return ContentInfo.getInstance(parsedObject);
+    }
+
+}