1 files changed, 65 insertions, 0 deletions

diff --git a/src/main/java/org/onap/crud/util/HashGenerator.java b/src/main/java/org/onap/crud/util/HashGenerator.java
new file mode 100644
index 0000000..02558fa
--- /dev/null
+++ b/src/main/java/org/onap/crud/util/HashGenerator.java
@@ -0,0 +1,65 @@
+/**
+ * ============LICENSE_START=======================================================
+ * org.onap.aai
+ * ================================================================================
+ * Copyright © 2017-2018 AT&T Intellectual Property. All rights reserved.
+ * Copyright © 2017-2018 Amdocs
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+package org.onap.crud.util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutput;
+import java.io.ObjectOutputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+/**
+ * Generates a sha 256 hash
+ */
+public class HashGenerator {
+
+    private MessageDigest messageDigest;
+
+    public HashGenerator() throws NoSuchAlgorithmException {
+        this.messageDigest = MessageDigest.getInstance("SHA-256");
+    }
+
+    /**
+     * Generates a SHA 256 hash as a hexadecimal string for the inputs.
+     * Calls toString on the input objects to convert into a byte stream.
+     * @param values
+     * @return SHA 256 hash of the inputs as a hexadecimal string.
+     * @throws IOException
+     */
+    public String generateSHA256AsHex(Object... values) throws IOException {
+        byte[] bytes = convertToBytes(values);
+        byte[] digest = messageDigest.digest(bytes);
+        StringBuilder result = new StringBuilder();
+        for (byte byt : digest) result.append(Integer.toString((byt & 0xff) + 0x100, 16).substring(1));
+        return result.toString();
+    }
+
+    private byte[] convertToBytes(Object... values) throws IOException {
+        try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
+             ObjectOutput out = new ObjectOutputStream(bos)) {
+            for (Object object : values) {
+                out.writeObject(object.toString());
+            }
+            return bos.toByteArray();
+        }
+    }
+
+}
\ No newline at end of file