--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/math/BigInteger/ModPow.java	Mon Jan 26 19:49:26 2009 -0800
@@ -0,0 +1,52 @@
+/*
+ * Copyright 1998 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/* @test
+ * @bug 4181191
+ * @summary test BigInteger modPow method
+ */
+import java.math.BigInteger;
+import java.util.Random;
+
+public class ModPow {
+    public static void main(String[] args) {
+        Random rnd = new Random(1234);
+
+        for (int i=0; i<2000; i++) {
+            BigInteger m = new BigInteger(800, rnd);
+            BigInteger base = new BigInteger(16, rnd);
+            if (rnd.nextInt() % 1 == 0)
+                base = base.negate();
+            BigInteger exp = new BigInteger(8, rnd);
+
+            BigInteger z = base.modPow(exp, m);
+            BigInteger w = base.pow(exp.intValue()).mod(m);
+            if (!z.equals(w)){
+                System.err.println(base +" ** " + exp + " mod "+ m);
+                System.err.println("modPow : " + z);
+                System.err.println("pow.mod: " + w);
+                throw new RuntimeException("BigInteger modPow failure.");
+            }
+        }
+    }
+}