8165751: NPE hit with java.security.debug=provider

Reviewed-by: mullan, weijun

jdk/src/java.base/share/classes/java/security/Signature.java

@@ -452,6 +452,10 @@ public abstract class Signature extends SignatureSpi {
         return this.provider;
     }
 
+    private String getProviderName() {
+        return (provider == null)  ? "(no provider)" : provider.getName();
+    }
+
     void chooseFirstProvider() {
         // empty, overridden in Delegate
     }
@@ -473,7 +477,7 @@ public abstract class Signature extends SignatureSpi {
 
         if (!skipDebug && pdebug != null) {
             pdebug.println("Signature." + algorithm +
-                " verification algorithm from: " + this.provider.getName());
+                " verification algorithm from: " + getProviderName());
         }
     }
 
@@ -522,7 +526,7 @@ public abstract class Signature extends SignatureSpi {
 
         if (!skipDebug && pdebug != null) {
             pdebug.println("Signature." + algorithm +
-                " verification algorithm from: " + this.provider.getName());
+                " verification algorithm from: " + getProviderName());
         }
     }
 
@@ -543,7 +547,7 @@ public abstract class Signature extends SignatureSpi {
 
         if (!skipDebug && pdebug != null) {
             pdebug.println("Signature." + algorithm +
-                " signing algorithm from: " + this.provider.getName());
+                " signing algorithm from: " + getProviderName());
         }
     }
 
@@ -566,7 +570,7 @@ public abstract class Signature extends SignatureSpi {
 
         if (!skipDebug && pdebug != null) {
             pdebug.println("Signature." + algorithm +
-                " signing algorithm from: " + this.provider.getName());
+                " signing algorithm from: " + getProviderName());
         }
     }
 

jdk/test/java/security/Signature/NoProvider.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8165751
+ * @summary Verify that that a subclass of Signature that does not contain a
+ *     provider can be used verify.
+ * @run main/othervm -Djava.security.debug=provider NoProvider
+ */
+
+import java.security.*;
+
+public class NoProvider {
+
+    private static class NoProviderPublicKey implements PublicKey {
+
+        public String getAlgorithm() {
+            return "NoProvider";
+        }
+        public String getFormat() {
+            return "none";
+        }
+        public byte[] getEncoded() {
+            return new byte[1];
+        }
+    }
+
+    private static class NoProviderSignature extends Signature {
+
+        public NoProviderSignature() {
+            super("NoProvider");
+        }
+
+        protected void engineInitVerify(PublicKey publicKey)
+            throws InvalidKeyException {
+            // do nothing
+        }
+
+        protected void engineInitSign(PrivateKey privateKey)
+            throws InvalidKeyException {
+            // do nothing
+        }
+
+        protected void engineUpdate(byte b) throws SignatureException {
+            // do nothing
+        }
+
+        protected void engineUpdate(byte[] b, int off, int len)
+            throws SignatureException {
+            // do nothing
+        }
+
+        protected byte[] engineSign() throws SignatureException {
+            return new byte[1];
+        }
+
+        protected boolean engineVerify(byte[] sigBytes)
+            throws SignatureException {
+            return false;
+        }
+
+        @Deprecated
+        protected void engineSetParameter(String param, Object value)
+            throws InvalidParameterException {
+            // do nothing
+        }
+
+        @Deprecated
+        protected Object engineGetParameter(String param)
+            throws InvalidParameterException {
+            return null;
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        new NoProviderSignature().initVerify(new NoProviderPublicKey());
+    }
+}