--- a/src/share/classes/sun/security/provider/SeedGenerator.java	Fri Dec 10 10:47:21 2010 +0000
+++ b/src/share/classes/sun/security/provider/SeedGenerator.java	Fri Dec 10 15:11:47 2010 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2009, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2010, 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
@@ -138,13 +138,7 @@
         instance.getSeedBytes(result);
     }
 
-    void getSeedBytes(byte[] result) {
-        for (int i = 0; i < result.length; i++) {
-          result[i] = getSeedByte();
-        }
-    }
-
-    abstract byte getSeedByte();
+    abstract void getSeedBytes(byte[] result);
 
     /**
      * Retrieve some system information, hashed.
@@ -369,6 +363,13 @@
             }
         }
 
+        @Override
+        void getSeedBytes(byte[] result) {
+            for (int i = 0; i < result.length; i++) {
+                result[i] = getSeedByte();
+            }
+        }
+
         byte getSeedByte() {
             byte b = 0;
 
@@ -455,8 +456,7 @@
     static class URLSeedGenerator extends SeedGenerator {
 
         private String deviceName;
-        private BufferedInputStream devRandom;
-
+        private InputStream devRandom;
 
         /**
          * The constructor is only called once to construct the one
@@ -465,7 +465,7 @@
          */
 
         URLSeedGenerator(String egdurl) throws IOException {
-            if (egdurl == null) {
+        if (egdurl == null) {
                 throw new IOException("No random source specified");
             }
             deviceName = egdurl;
@@ -478,41 +478,78 @@
 
         private void init() throws IOException {
             final URL device = new URL(deviceName);
-            devRandom = java.security.AccessController.doPrivileged
-                (new java.security.PrivilegedAction<BufferedInputStream>() {
-                        public BufferedInputStream run() {
-                            try {
-                                return new BufferedInputStream(device.openStream());
-                            } catch (IOException ioe) {
-                                return null;
+            try {
+                devRandom = java.security.AccessController.doPrivileged
+                    (new java.security.PrivilegedExceptionAction<InputStream>() {
+                        public InputStream run() throws IOException {
+                            /*
+                             * return a FileInputStream for file URLs and
+                             * avoid buffering. The openStream() call wraps
+                             * InputStream in a BufferedInputStream which
+                             * can buffer up to 8K bytes. This read is a
+                             * performance issue for entropy sources which
+                             * can be slow to replenish.
+                             */
+                            if (device.getProtocol().equalsIgnoreCase("file")) {
+                                File deviceFile = getDeviceFile(device);
+                                return new FileInputStream(deviceFile);
+                            } else {
+                                return device.openStream();
                             }
                         }
                     });
-
-            if (devRandom == null) {
-                throw new IOException("failed to open " + device);
+            } catch (Exception e) {
+                throw new IOException("Failed to open " + deviceName, e.getCause());
             }
         }
 
-        byte getSeedByte() {
-            byte b[] = new byte[1];
-            int stat;
+        /*
+         * Use a URI to access this File. Previous code used a URL
+         * which is less strict on syntax. If we encounter a
+         * URISyntaxException we make best efforts for backwards
+         * compatibility. e.g. space character in deviceName string.
+         *
+         * Method called within PrivilegedExceptionAction block.
+         */
+        private File getDeviceFile(URL device) throws IOException {
             try {
-                stat = devRandom.read(b, 0, b.length);
+                URI deviceURI = device.toURI();
+                if(deviceURI.isOpaque()) {
+                    // File constructor does not accept opaque URI
+                    URI localDir = new File(System.getProperty("user.dir")).toURI();
+                    String uriPath = localDir.toString() +
+                                         deviceURI.toString().substring(5);
+                    return new File(URI.create(uriPath));
+                } else {
+                    return new File(deviceURI);
+                }
+            } catch (URISyntaxException use) {
+                /*
+                 * Make best effort to access this File.
+                 * We can try using the URL path.
+                 */
+                return new File(device.getPath());
+            }
+        }
+
+        @Override
+        void getSeedBytes(byte[] result) {
+            int len = result.length;
+            int read = 0;
+            try {
+                while (read < len) {
+                    int count = devRandom.read(result, read, len - read);
+                    // /dev/random blocks - should never have EOF
+                    if (count < 0)
+                        throw new InternalError("URLSeedGenerator " + deviceName +
+                                        " reached end of file");
+                    read += count;
+                }
             } catch (IOException ioe) {
                 throw new InternalError("URLSeedGenerator " + deviceName +
                                         " generated exception: " +
                                         ioe.getMessage());
             }
-            if (stat == b.length) {
-                return b[0];
-            } else if (stat == -1) {
-                throw new InternalError("URLSeedGenerator " + deviceName +
-                                           " reached end of file");
-            } else {
-                throw new InternalError("URLSeedGenerator " + deviceName +
-                                           " failed read");
-            }
         }
 
     }

--- a/src/windows/classes/sun/security/provider/NativeSeedGenerator.java	Fri Dec 10 10:47:21 2010 +0000
+++ b/src/windows/classes/sun/security/provider/NativeSeedGenerator.java	Fri Dec 10 15:11:47 2010 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2010, 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
@@ -53,6 +53,7 @@
      */
     private static native boolean nativeGenerateSeed(byte[] result);
 
+    @Override
     void getSeedBytes(byte[] result) {
         // fill array as a side effect
         if (nativeGenerateSeed(result) == false) {
@@ -62,9 +63,4 @@
         }
     }
 
-    byte getSeedByte() {
-        byte[] b = new byte[1];
-        getSeedBytes(b);
-        return b[0];
-    }
 }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/sun/security/provider/SeedGenerator/SeedGeneratorChoice.java	Fri Dec 10 15:11:47 2010 +0000
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
+ *
+ * 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 6998583
+ * @summary NativeSeedGenerator is making 8192 byte read requests from
+ *             entropy pool on each init.
+ * @run main SeedGeneratorChoice
+ * @run main/othervm -Djava.security.egd=file:/dev/random SeedGeneratorChoice
+ * @run main/othervm -Djava.security.egd=file:filename  SeedGeneratorChoice
+ */
+
+/*
+ * Side testcase introduced to ensure changes for 6998583 will always
+ * succeed in falling back to ThreadedSeedGenerator if issues are found
+ * with the native OS generator request. We should never see an exception
+ * causing exit.
+ * We should always fall back to the ThreadedSeedGenerator if exceptions
+ * are encountered with user defined source of entropy.
+ */
+
+import java.security.SecureRandom;
+
+public class SeedGeneratorChoice {
+
+    public static void main(String... arguments) throws Exception {
+        byte[] bytes;
+        SecureRandom prng = SecureRandom.getInstance("SHA1PRNG");
+        bytes = prng.generateSeed(1);
+    }
+}