From 6103d96e8334e382b2b1c13b32c17e948a23bc60 Mon Sep 17 00:00:00 2001
From: Jason Tedor <jason@tedor.me>
Date: Sun, 4 Oct 2015 16:25:15 -0400
Subject: [PATCH] Use abstraction from core

Original commit: elastic/x-pack-elasticsearch@01b66264e0248277f0eb07194c0b4665833c4cb6
---
 .../renderer/cluster/ClusterInfoRenderer.java | 36 ++-----------------
 1 file changed, 3 insertions(+), 33 deletions(-)

diff --git a/marvel/src/main/java/org/elasticsearch/marvel/agent/renderer/cluster/ClusterInfoRenderer.java b/marvel/src/main/java/org/elasticsearch/marvel/agent/renderer/cluster/ClusterInfoRenderer.java
index d723f7b3093..be559aea3a5 100644
--- a/marvel/src/main/java/org/elasticsearch/marvel/agent/renderer/cluster/ClusterInfoRenderer.java
+++ b/marvel/src/main/java/org/elasticsearch/marvel/agent/renderer/cluster/ClusterInfoRenderer.java
@@ -7,6 +7,7 @@ package org.elasticsearch.marvel.agent.renderer.cluster;
 
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.action.admin.cluster.stats.ClusterStatsResponse;
+import org.elasticsearch.common.hash.MessageDigests;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentBuilderString;
@@ -16,34 +17,12 @@ import org.elasticsearch.marvel.agent.renderer.AbstractRenderer;
 
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.List;
 
 public class ClusterInfoRenderer extends AbstractRenderer<ClusterInfoMarvelDoc> {
-
-    static final class MessageDigestSHA256Provider {
-        private static final MessageDigest digest;
-
-        static {
-            try {
-                digest = MessageDigest.getInstance("SHA-256");
-            } catch (NoSuchAlgorithmException e) {
-                throw new ElasticsearchException("Unexpected exception creating MessageDigest instance", e);
-            }
-        }
-
-        private static MessageDigest sha256() {
-            try {
-                MessageDigest sha = (MessageDigest) digest.clone();
-                sha.reset();
-                return sha;
-            } catch (CloneNotSupportedException e) {
-                throw new ElasticsearchException("Unexpected exception creating MessageDigest instance", e);
-            }
-        }
-    }
-
     public ClusterInfoRenderer() {
         super(null, false);
     }
@@ -88,16 +67,7 @@ public class ClusterInfoRenderer extends AbstractRenderer<ClusterInfoMarvelDoc>
 
     public static String hash(String licenseStatus, String licenseUid, String licenseType, String licenseExpiryDate, String clusterUUID) {
         String toHash = licenseStatus + licenseUid + licenseType + licenseExpiryDate + clusterUUID;
-        try {
-            byte[] sha256Bytes = MessageDigestSHA256Provider.sha256().digest(toHash.getBytes("UTF-8"));
-            StringBuffer hash = new StringBuffer();
-            for (int i = 0; i < sha256Bytes.length; i++) {
-                hash.append(Integer.toHexString(0xff & sha256Bytes[i]));
-            }
-            return hash.toString();
-        } catch (UnsupportedEncodingException e) {
-            throw new ElasticsearchException("Unexpected error calculating SHA-256 MessageDigest", e);
-        }
+        return MessageDigests.toHexString(MessageDigests.sha256().digest(toHash.getBytes(StandardCharsets.UTF_8)));
     }
 
     static final class Fields {