diff -r 0f93a75b9213 -r 3810c9a2efa1 src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/keys/keyresolver/KeyResolverSpi.java
--- a/src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/keys/keyresolver/KeyResolverSpi.java	Mon Jun 18 15:24:48 2018 -0700
+++ b/src/java.xml.crypto/share/classes/com/sun/org/apache/xml/internal/security/keys/keyresolver/KeyResolverSpi.java	Tue Jun 19 08:06:35 2018 +0800
@@ -22,15 +22,23 @@
  */
 package com.sun.org.apache.xml.internal.security.keys.keyresolver;
 
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
 import java.security.PrivateKey;
 import java.security.PublicKey;
 import java.security.cert.X509Certificate;
 import java.util.HashMap;
 
 import javax.crypto.SecretKey;
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.ParserConfigurationException;
 
 import com.sun.org.apache.xml.internal.security.keys.storage.StorageResolver;
+import com.sun.org.apache.xml.internal.security.utils.XMLUtils;
+import org.w3c.dom.Document;
 import org.w3c.dom.Element;
+import org.xml.sax.SAXException;
 
 /**
  * This class is an abstract class for a child KeyInfo Element.
@@ -45,7 +53,7 @@
 public abstract class KeyResolverSpi {
 
     /** Field properties */
-    protected java.util.Map<String, String> properties = null;
+    protected java.util.Map<String, String> properties;
 
     protected boolean globalResolver = false;
 
@@ -84,7 +92,7 @@
         Element element, String baseURI, StorageResolver storage
     ) throws KeyResolverException {
         throw new UnsupportedOperationException();
-    };
+    }
 
     /**
      * Method engineLookupAndResolvePublicKey
@@ -107,19 +115,18 @@
     }
 
     private KeyResolverSpi cloneIfNeeded() throws KeyResolverException {
-        KeyResolverSpi tmp = this;
         if (globalResolver) {
             try {
                 @SuppressWarnings("deprecation")
-                KeyResolverSpi krs = getClass().newInstance();
-                tmp = krs;
+                KeyResolverSpi tmp = getClass().newInstance();
+                return tmp;
             } catch (InstantiationException e) {
-                throw new KeyResolverException("", e);
+                throw new KeyResolverException(e, "");
             } catch (IllegalAccessException e) {
-                throw new KeyResolverException("", e);
+                throw new KeyResolverException(e, "");
             }
         }
-        return tmp;
+        return this;
     }
 
     /**
@@ -136,7 +143,7 @@
         Element element, String baseURI, StorageResolver storage
     ) throws KeyResolverException{
         throw new UnsupportedOperationException();
-    };
+    }
 
     /**
      * Method engineLookupResolveX509Certificate
@@ -172,7 +179,7 @@
         Element element, String baseURI, StorageResolver storage
     ) throws KeyResolverException{
         throw new UnsupportedOperationException();
-    };
+    }
 
     /**
      * Method engineLookupAndResolveSecretKey
@@ -223,7 +230,7 @@
      */
     public void engineSetProperty(String key, String value) {
         if (properties == null) {
-            properties = new HashMap<String, String>();
+            properties = new HashMap<>();
         }
         properties.put(key, value);
     }
@@ -260,4 +267,27 @@
         this.globalResolver = globalResolver;
     }
 
+
+    /**
+     * Parses a byte array and returns the parsed Element.
+     *
+     * @param bytes
+     * @return the Document Element after parsing bytes
+     * @throws KeyResolverException if something goes wrong
+     */
+    protected static Element getDocFromBytes(byte[] bytes, boolean secureValidation) throws KeyResolverException {
+        DocumentBuilder db = null;
+        try (InputStream is = new ByteArrayInputStream(bytes)) {
+            db = XMLUtils.createDocumentBuilder(false, secureValidation);
+            Document doc = db.parse(is);
+            return doc.getDocumentElement();
+        } catch (SAXException ex) {
+            throw new KeyResolverException(ex);
+        } catch (IOException ex) {
+            throw new KeyResolverException(ex);
+        } catch (ParserConfigurationException ex) {
+            throw new KeyResolverException(ex);
+        }
+    }
+
 }