1 files changed, 55 insertions, 0 deletions
diff --git a/certService/src/main/java/org/onap/oom/certservice/certification/conversion/StringBase64ToPrivateKeyConverter.java b/certService/src/main/java/org/onap/oom/certservice/certification/conversion/StringBase64ToPrivateKeyConverter.java
new file mode 100644
index 00000000..1ea752b1
--- /dev/null
+++ b/certService/src/main/java/org/onap/oom/certservice/certification/conversion/StringBase64ToPrivateKeyConverter.java
@@ -0,0 +1,55 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nokia.
+ * ================================================================================
+ * 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
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.certification.conversion;
+
+import org.bouncycastle.util.io.pem.PemObject;
+import org.onap.oom.certservice.certification.exception.KeyDecryptionException;
+
+import java.security.KeyFactory;
+import java.security.NoSuchAlgorithmException;
+import java.security.PrivateKey;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.PKCS8EncodedKeySpec;
+
+public class StringBase64ToPrivateKeyConverter {
+
+    private final PemObjectFactory pemObjectFactory = new PemObjectFactory();
+
+    public PrivateKey convert(StringBase64 privateKey) throws KeyDecryptionException {
+        PemObject decodedPrivateKey = createDecodedPrivateKey(privateKey);
+        try {
+            KeyFactory factory = KeyFactory.getInstance("RSA");
+            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(decodedPrivateKey.getContent());
+            return factory.generatePrivate(keySpec);
+        } catch (NoSuchAlgorithmException | InvalidKeySpecException e) {
+            throw new KeyDecryptionException("Converting Private Key failed", e.getCause());
+        }
+    }
+
+    private PemObject createDecodedPrivateKey(StringBase64 privateKey) throws KeyDecryptionException {
+        return privateKey.asString()
+                .flatMap(pemObjectFactory::createPemObject)
+                .orElseThrow(
+                        () -> new KeyDecryptionException("Incorrect Key, decryption failed")
+                );
+    }
+
+}