obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.

1 files changed, 985 insertions, 0 deletions

diff --git a/libjava/classpath/gnu/javax/crypto/prng/CSPRNG.java b/libjava/classpath/gnu/javax/crypto/prng/CSPRNG.java
new file mode 100644
index 000000000..ecea2f469
--- /dev/null
+++ b/libjava/classpath/gnu/javax/crypto/prng/CSPRNG.java
@@ -0,0 +1,985 @@
+/* CSPRNG.java -- continuously-seeded pseudo-random number generator.
+   Copyright (C) 2004, 2006 Free Software Foundation, Inc.
+
+This file is a part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or (at
+your option) any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
+USA
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version.  */
+
+
+package gnu.javax.crypto.prng;
+
+import gnu.java.security.Configuration;
+import gnu.java.security.Properties;
+import gnu.java.security.Registry;
+import gnu.java.security.hash.HashFactory;
+import gnu.java.security.hash.IMessageDigest;
+import gnu.java.security.prng.BasePRNG;
+import gnu.java.security.prng.EntropySource;
+import gnu.java.security.prng.IRandom;
+import gnu.java.security.prng.LimitReachedException;
+import gnu.java.security.util.SimpleList;
+import gnu.java.security.util.Util;
+import gnu.javax.crypto.cipher.CipherFactory;
+import gnu.javax.crypto.cipher.IBlockCipher;
+
+import java.io.ByteArrayOutputStream;
+import java.io.FileInputStream;
+import java.io.InputStream;
+import java.io.PrintStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.security.AccessController;
+import java.security.InvalidKeyException;
+import java.security.PrivilegedAction;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.StringTokenizer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * An entropy pool-based pseudo-random number generator based on the PRNG in
+ * Peter Gutmann's cryptlib (<a
+ * href="http://www.cs.auckland.ac.nz/~pgut001/cryptlib/">http://www.cs.auckland.ac.nz/~pgut001/cryptlib/</a>).
+ * <p>
+ * The basic properties of this generator are:
+ * <ol>
+ * <li>The internal state cannot be determined by knowledge of the input.</li>
+ * <li>It is resistant to bias introduced by specific inputs.</li>
+ * <li>The output does not reveal the state of the generator.</li>
+ * </ol>
+ */
+public class CSPRNG
+    extends BasePRNG
+{
+  private static final Logger log = Logger.getLogger(CSPRNG.class.getName());
+  /**
+   * Property name for the list of files to read for random values. The mapped
+   * value is a list with the following values:
+   * <ol>
+   * <li>A {@link Double}, indicating the suggested <i>quality</i> of this
+   * source. This value must be between 0 and 100.</li>
+   * <li>An {@link Integer}, indicating the number of bytes to skip in the
+   * file before reading bytes. This can be any nonnegative value.</li>
+   * <li>An {@link Integer}, indicating the number of bytes to read.</li>
+   * <li>A {@link String}, indicating the path to the file.</li>
+   * </ol>
+   *
+   * @see gnu.java.security.util.SimpleList
+   */
+  public static final String FILE_SOURCES = "gnu.crypto.prng.pool.files";
+  /**
+   * Property name for the list of URLs to poll for random values. The mapped
+   * value is a list formatted similarly as in {@link #FILE_SOURCES}, but the
+   * fourth member is a {@link URL}.
+   */
+  public static final String URL_SOURCES = "gnu.crypto.prng.pool.urls";
+  /**
+   * Property name for the list of programs to execute, and use the output as
+   * new random bytes. The mapped property is formatted similarly an in
+   * {@link #FILE_SOURCES} and {@link #URL_SOURCES}, except the fourth member
+   * is a {@link String} of the program to execute.
+   */
+  public static final String PROGRAM_SOURCES = "gnu.crypto.prng.pool.programs";
+  /**
+   * Property name for a list of other sources of entropy. The mapped value must
+   * be a list of {@link EntropySource} objects.
+   */
+  public static final String OTHER_SOURCES = "gnu.crypto.prng.pool.other";
+  /**
+   * Property name for whether or not to wait for the slow poll to complete,
+   * passed as a {@link Boolean}. The default value is true.
+   */
+  public static final String BLOCKING = "gnu.crypto.prng.pool.blocking";
+  private static final String FILES = "gnu.crypto.csprng.file.";
+  private static final String URLS = "gnu.crypto.csprng.url.";
+  private static final String PROGS = "gnu.crypto.csprng.program.";
+  private static final String OTHER = "gnu.crypto.csprng.other.";
+  private static final String BLOCK = "gnu.crypto.csprng.blocking";
+  private static final int POOL_SIZE = 256;
+  private static final int ALLOC_SIZE = 260;
+  private static final int OUTPUT_SIZE = POOL_SIZE / 2;
+  private static final int X917_POOL_SIZE = 16;
+  private static final String HASH_FUNCTION = Registry.SHA160_HASH;
+  private static final String CIPHER = Registry.AES_CIPHER;
+  private static final int MIX_COUNT = 10;
+  private static final int X917_LIFETIME = 8192;
+  // FIXME this should be configurable.
+  private static final int SPINNER_COUNT = 8;
+  /**
+   * The spinner group singleton. We use this to add a small amount of
+   * randomness (in addition to the current time and the amount of free memory)
+   * based on the randomness (if any) present due to system load and thread
+   * scheduling.
+   */
+  private static final Spinner[] SPINNERS = new Spinner[SPINNER_COUNT];
+  private static final Thread[] SPINNER_THREADS = new Thread[SPINNER_COUNT];
+  static
+    {
+      for (int i = 0; i < SPINNER_COUNT; i++)
+        {
+          SPINNER_THREADS[i] = new Thread(SPINNERS[i] = new Spinner(),
+                                          "spinner-" + i);
+          SPINNER_THREADS[i].setDaemon(true);
+          SPINNER_THREADS[i].setPriority(Thread.MIN_PRIORITY);
+          SPINNER_THREADS[i].start();
+        }
+    }
+  /** The message digest (SHA-1) used in the mixing function. */
+  private final IMessageDigest hash;
+  /** The cipher (AES) used in the output masking function. */
+  private final IBlockCipher cipher;
+  /** The number of times the pool has been mixed. */
+  private int mixCount;
+  /** The entropy pool. */
+  private final byte[] pool;
+  /** The quality of the random pool (percentage). */
+  private double quality;
+  /** The index of the next byte in the entropy pool. */
+  private int index;
+  /** The pool for the X9.17-like generator. */
+  private byte[] x917pool;
+  /** The number of iterations of the X9.17-like generators. */
+  private int x917count;
+  /** Whether or not the X9.17-like generator is initialized. */
+  private boolean x917init;
+  /** The list of file soures. */
+  private final List files;
+  /** The list of URL sources. */
+  private final List urls;
+  /** The list of program sources. */
+  private final List progs;
+  /** The list of other sources. */
+  private final List other;
+  /** Whether or not to wait for the slow poll to complete. */
+  private boolean blocking;
+  /** The thread that polls for random data. */
+  private Poller poller;
+  private Thread pollerThread;
+
+  public CSPRNG()
+  {
+    super("CSPRNG");
+    pool = new byte[ALLOC_SIZE];
+    x917pool = new byte[X917_POOL_SIZE];
+    x917count = 0;
+    x917init = false;
+    quality = 0.0;
+    hash = HashFactory.getInstance(HASH_FUNCTION);
+    cipher = CipherFactory.getInstance(CIPHER);
+    buffer = new byte[OUTPUT_SIZE];
+    ndx = 0;
+    initialised = false;
+    files = new LinkedList();
+    urls = new LinkedList();
+    progs = new LinkedList();
+    other = new LinkedList();
+  }
+
+  /**
+   * Create and initialize a CSPRNG instance with the "system" parameters; the
+   * files, URLs, programs, and {@link EntropySource} sources used by the
+   * instance are derived from properties set in the system {@link Properties}.
+   * <p>
+   * All properties are of the from <i>name</i>.</i>N</i>, where <i>name</i>
+   * is the name of the source, and <i>N</i> is an integer (staring at 1) that
+   * indicates the preference number for that source.
+   * <p>
+   * The following vales for <i>name</i> are used here:
+   * <dl>
+   * <dt>gnu.crypto.csprng.file</dt>
+   * <dd>
+   * <p>
+   * These properties are file sources, passed as the {@link #FILE_SOURCES}
+   * parameter of the instance. The property value is a 4-tuple formatted as:
+   * </p>
+   * <blockquote><i>quality</i> ; <i>offset</i> ; <i>count</i> ; <i>path</i></blockquote>
+   * <p>
+   * The parameters are mapped to the parameters defined for {@link
+   * #FILE_SOURCES}. Leading or trailing spaces on any item are trimmed off.
+   * </p>
+   * </dd>
+   * <dt>gnu.crypto.csprng.url</dt>
+   * <dd>
+   * <p>
+   * These properties are URL sources, passed as the {@link #URL_SOURCES}
+   * parameter of the instance. The property is formatted the same way as file
+   * sources, but the <i>path</i> argument must be a valid URL.
+   * </p>
+   * </dd>
+   * <dt>gnu.crypto.csprng.program</dt>
+   * <dd>
+   * <p>
+   * These properties are program sources, passed as the {@link
+   * #PROGRAM_SOURCES} parameter of the instance. This property is formatted the
+   * same way as file and URL sources, but the last argument is a program and
+   * its arguments.
+   * </p>
+   * </dd>
+   * <dt>gnu.crypto.cspring.other</dt>
+   * <dd>
+   * <p>
+   * These properties are other sources, passed as the {@link #OTHER_SOURCES}
+   * parameter of the instance. The property value must be the full name of a
+   * class that implements the {@link EntropySource} interface and has a public
+   * no-argument constructor.
+   * </p>
+   * </dd>
+   * </dl>
+   * <p>
+   * Finally, a boolean property "gnu.crypto.csprng.blocking" can be set to the
+   * desired value of {@link #BLOCKING}.
+   * <p>
+   * An example of valid properties would be:
+   * <pre>
+   *  gnu.crypto.csprng.blocking=true
+   *
+   *  gnu.crypto.csprng.file.1=75.0;0;256;/dev/random
+   *  gnu.crypto.csprng.file.2=10.0;0;100;/home/user/file
+   *
+   *  gnu.crypto.csprng.url.1=5.0;0;256;http://www.random.org/cgi-bin/randbyte?nbytes=256
+   *  gnu.crypto.csprng.url.2=0;256;256;http://slashdot.org/
+   *
+   *  gnu.crypto.csprng.program.1=0.5;0;10;last -n 50
+   *  gnu.crypto.csprng.program.2=0.5;0;10;tcpdump -c 5
+   *
+   *  gnu.crypto.csprng.other.1=foo.bar.MyEntropySource
+   *  gnu.crypto.csprng.other.2=com.company.OtherEntropySource
+   * </pre>
+   */
+  public static IRandom getSystemInstance() throws ClassNotFoundException,
+      MalformedURLException, NumberFormatException
+  {
+    CSPRNG instance = new CSPRNG();
+    HashMap attrib = new HashMap();
+    attrib.put(BLOCKING, Boolean.valueOf(getProperty(BLOCK)));
+    String s = null;
+    // Get each file source "gnu.crypto.csprng.file.N".
+    List l = new LinkedList();
+    for (int i = 0; (s = getProperty(FILES + i)) != null; i++)
+      try
+        {
+          l.add(parseString(s.trim()));
+        }
+      catch (NumberFormatException nfe)
+        {
+        }
+    attrib.put(FILE_SOURCES, l);
+    l = new LinkedList();
+    for (int i = 0; (s = getProperty(URLS + i)) != null; i++)
+      try
+        {
+          l.add(parseURL(s.trim()));
+        }
+      catch (NumberFormatException nfe)
+        {
+        }
+      catch (MalformedURLException mue)
+        {
+        }
+    attrib.put(URL_SOURCES, l);
+    l = new LinkedList();
+    for (int i = 0; (s = getProperty(PROGS + i)) != null; i++)
+      try
+        {
+          l.add(parseString(s.trim()));
+        }
+      catch (NumberFormatException nfe)
+        {
+        }
+    attrib.put(PROGRAM_SOURCES, l);
+    l = new LinkedList();
+    for (int i = 0; (s = getProperty(OTHER + i)) != null; i++)
+      try
+        {
+          Class c = Class.forName(s.trim());
+          l.add(c.newInstance());
+        }
+      catch (ClassNotFoundException cnfe)
+        {
+        }
+      catch (InstantiationException ie)
+        {
+        }
+      catch (IllegalAccessException iae)
+        {
+        }
+    attrib.put(OTHER_SOURCES, l);
+    instance.init(attrib);
+    return instance;
+  }
+
+  private static String getProperty(final String name)
+  {
+    return (String) AccessController.doPrivileged(new PrivilegedAction()
+    {
+      public Object run()
+      {
+        return Properties.getProperty(name);
+      }
+    });
+  }
+
+  private static List parseString(String s) throws NumberFormatException
+  {
+    StringTokenizer tok = new StringTokenizer(s, ";");
+    if (tok.countTokens() != 4)
+      throw new IllegalArgumentException("malformed property");
+    Double quality = new Double(tok.nextToken());
+    Integer offset = new Integer(tok.nextToken());
+    Integer length = new Integer(tok.nextToken());
+    String str = tok.nextToken();
+    return new SimpleList(quality, offset, length, str);
+  }
+
+  private static List parseURL(String s) throws MalformedURLException,
+      NumberFormatException
+  {
+    StringTokenizer tok = new StringTokenizer(s, ";");
+    if (tok.countTokens() != 4)
+      throw new IllegalArgumentException("malformed property");
+    Double quality = new Double(tok.nextToken());
+    Integer offset = new Integer(tok.nextToken());
+    Integer length = new Integer(tok.nextToken());
+    URL url = new URL(tok.nextToken());
+    return new SimpleList(quality, offset, length, url);
+  }
+
+  public Object clone()
+  {
+    return new CSPRNG();
+  }
+
+  public void setup(Map attrib)
+  {
+    List list = null;
+    if (Configuration.DEBUG)
+      log.fine("attrib=" + String.valueOf(attrib));
+    try
+      {
+        list = (List) attrib.get(FILE_SOURCES);
+        if (Configuration.DEBUG)
+          log.fine("list=" + String.valueOf(list));
+        if (list != null)
+          {
+            files.clear();
+            for (Iterator it = list.iterator(); it.hasNext();)
+              {
+                List l = (List) it.next();
+                if (Configuration.DEBUG)
+                  log.fine("l=" + l);
+                if (l.size() != 4)
+                  {
+                    if (Configuration.DEBUG)
+                      log.fine("file list too small: " + l.size());
+                    throw new IllegalArgumentException("invalid file list");
+                  }
+                Double quality = (Double) l.get(0);
+                Integer offset = (Integer) l.get(1);
+                Integer length = (Integer) l.get(2);
+                String source = (String) l.get(3);
+                files.add(new SimpleList(quality, offset, length, source));
+              }
+          }
+      }
+    catch (ClassCastException cce)
+      {
+        if (Configuration.DEBUG)
+          log.log(Level.FINE, "bad file list", cce);
+        throw new IllegalArgumentException("invalid file list");
+      }
+    try
+      {
+        list = (List) attrib.get(URL_SOURCES);
+        if (Configuration.DEBUG)
+          log.fine("list=" + String.valueOf(list));
+        if (list != null)
+          {
+            urls.clear();
+            for (Iterator it = list.iterator(); it.hasNext();)
+              {
+                List l = (List) it.next();
+                if (Configuration.DEBUG)
+                  log.fine("l=" + l);
+                if (l.size() != 4)
+                  {
+                    if (Configuration.DEBUG)
+                      log.fine("URL list too small: " + l.size());
+                    throw new IllegalArgumentException("invalid URL list");
+                  }
+                Double quality = (Double) l.get(0);
+                Integer offset = (Integer) l.get(1);
+                Integer length = (Integer) l.get(2);
+                URL source = (URL) l.get(3);
+                urls.add(new SimpleList(quality, offset, length, source));
+              }
+          }
+      }
+    catch (ClassCastException cce)
+      {
+        if (Configuration.DEBUG)
+          log.log(Level.FINE, "bad URL list", cce);
+        throw new IllegalArgumentException("invalid URL list");
+      }
+    try
+      {
+        list = (List) attrib.get(PROGRAM_SOURCES);
+        if (Configuration.DEBUG)
+          log.fine("list=" + String.valueOf(list));
+        if (list != null)
+          {
+            progs.clear();
+            for (Iterator it = list.iterator(); it.hasNext();)
+              {
+                List l = (List) it.next();
+                if (Configuration.DEBUG)
+                  log.fine("l=" + l);
+                if (l.size() != 4)
+                  {
+                    if (Configuration.DEBUG)
+                      log.fine("program list too small: " + l.size());
+                    throw new IllegalArgumentException("invalid program list");
+                  }
+                Double quality = (Double) l.get(0);
+                Integer offset = (Integer) l.get(1);
+                Integer length = (Integer) l.get(2);
+                String source = (String) l.get(3);
+                progs.add(new SimpleList(quality, offset, length, source));
+              }
+          }
+      }
+    catch (ClassCastException cce)
+      {
+        if (Configuration.DEBUG)
+          log.log(Level.FINE, "bad program list", cce);
+        throw new IllegalArgumentException("invalid program list");
+      }
+    try
+      {
+        list = (List) attrib.get(OTHER_SOURCES);
+        if (Configuration.DEBUG)
+          log.fine("list=" + String.valueOf(list));
+        if (list != null)
+          {
+            other.clear();
+            for (Iterator it = list.iterator(); it.hasNext();)
+              {
+                EntropySource src = (EntropySource) it.next();
+                if (Configuration.DEBUG)
+                  log.fine("src=" + src);
+                if (src == null)
+                  throw new NullPointerException("null source in source list");
+                other.add(src);
+              }
+          }
+      }
+    catch (ClassCastException cce)
+      {
+        throw new IllegalArgumentException("invalid source list");
+      }
+
+    try
+      {
+        Boolean block = (Boolean) attrib.get(BLOCKING);
+        if (block != null)
+          blocking = block.booleanValue();
+        else
+          blocking = true;
+      }
+    catch (ClassCastException cce)
+      {
+        throw new IllegalArgumentException("invalid blocking parameter");
+      }
+    poller = new Poller(files, urls, progs, other, this);
+    try
+      {
+        fillBlock();
+      }
+    catch (LimitReachedException lre)
+      {
+        throw new RuntimeException("bootstrapping CSPRNG failed");
+      }
+  }
+
+  public void fillBlock() throws LimitReachedException
+  {
+    if (Configuration.DEBUG)
+      log.fine("fillBlock");
+    if (getQuality() < 100.0)
+      {
+        if (Configuration.DEBUG)
+          log.fine("doing slow poll");
+        slowPoll();
+      }
+    do
+      {
+        fastPoll();
+        mixRandomPool();
+      }
+    while (mixCount < MIX_COUNT);
+    if (! x917init || x917count >= X917_LIFETIME)
+      {
+        mixRandomPool(pool);
+        Map attr = new HashMap();
+        byte[] key = new byte[32];
+        System.arraycopy(pool, 0, key, 0, 32);
+        cipher.reset();
+        attr.put(IBlockCipher.KEY_MATERIAL, key);
+        try
+          {
+            cipher.init(attr);
+          }
+        catch (InvalidKeyException ike)
+          {
+            throw new Error(ike.toString());
+          }
+        mixRandomPool(pool);
+        generateX917(pool);
+        mixRandomPool(pool);
+        generateX917(pool);
+        if (x917init)
+          quality = 0.0;
+        x917init = true;
+        x917count = 0;
+      }
+    byte[] export = new byte[ALLOC_SIZE];
+    for (int i = 0; i < ALLOC_SIZE; i++)
+      export[i] = (byte)(pool[i] ^ 0xFF);
+    mixRandomPool();
+    mixRandomPool(export);
+    generateX917(export);
+    for (int i = 0; i < OUTPUT_SIZE; i++)
+      buffer[i] = (byte)(export[i] ^ export[i + OUTPUT_SIZE]);
+    Arrays.fill(export, (byte) 0);
+  }
+
+  /**
+   * Add an array of bytes into the randomness pool. Note that this method will
+   * <i>not</i> increment the pool's quality counter (this can only be done via
+   * a source provided to the setup method).
+   *
+   * @param buf The byte array.
+   * @param off The offset from whence to start reading bytes.
+   * @param len The number of bytes to add.
+   * @throws ArrayIndexOutOfBoundsException If <i>off</i> or <i>len</i> are
+   *           out of the range of <i>buf</i>.
+   */
+  public synchronized void addRandomBytes(byte[] buf, int off, int len)
+  {
+    if (off < 0 || len < 0 || off + len > buf.length)
+      throw new ArrayIndexOutOfBoundsException();
+    if (Configuration.DEBUG)
+      {
+        log.fine("adding random bytes:");
+        log.fine(Util.toString(buf, off, len));
+      }
+    final int count = off + len;
+    for (int i = off; i < count; i++)
+      {
+        pool[index++] ^= buf[i];
+        if (index == pool.length)
+          {
+            mixRandomPool();
+            index = 0;
+          }
+      }
+  }
+
+  /**
+   * Add a single random byte to the randomness pool. Note that this method will
+   * <i>not</i> increment the pool's quality counter (this can only be done via
+   * a source provided to the setup method).
+   *
+   * @param b The byte to add.
+   */
+  public synchronized void addRandomByte(byte b)
+  {
+    if (Configuration.DEBUG)
+      log.fine("adding byte " + Integer.toHexString(b));
+    pool[index++] ^= b;
+    if (index >= pool.length)
+      {
+        mixRandomPool();
+        index = 0;
+      }
+  }
+
+  synchronized void addQuality(double quality)
+  {
+    if (Configuration.DEBUG)
+      log.fine("adding quality " + quality);
+    if (this.quality < 100)
+      this.quality += quality;
+    if (Configuration.DEBUG)
+      log.fine("quality now " + this.quality);
+  }
+
+  synchronized double getQuality()
+  {
+    return quality;
+  }
+
+  /**
+   * The mix operation. This method will, for every 20-byte block in the random
+   * pool, hash that block, the previous 20 bytes, and the next 44 bytes with
+   * SHA-1, writing the result back into that block.
+   */
+  private void mixRandomPool(byte[] buf)
+  {
+    int hashSize = hash.hashSize();
+    for (int i = 0; i < buf.length; i += hashSize)
+      {
+        // First update the bytes [p-19..p-1].
+        if (i == 0)
+          hash.update(buf, buf.length - hashSize, hashSize);
+        else
+          hash.update(buf, i - hashSize, hashSize);
+        // Now the next 64 bytes.
+        if (i + 64 < buf.length)
+          hash.update(buf, i, 64);
+        else
+          {
+            hash.update(buf, i, buf.length - i);
+            hash.update(buf, 0, 64 - (buf.length - i));
+          }
+        byte[] digest = hash.digest();
+        System.arraycopy(digest, 0, buf, i, hashSize);
+      }
+  }
+
+  private void mixRandomPool()
+  {
+    mixRandomPool(pool);
+    mixCount++;
+  }
+
+  private void generateX917(byte[] buf)
+  {
+    int off = 0;
+    for (int i = 0; i < buf.length; i += X917_POOL_SIZE)
+      {
+        int copy = Math.min(buf.length - i, X917_POOL_SIZE);
+        for (int j = 0; j < copy; j++)
+          x917pool[j] ^= pool[off + j];
+        cipher.encryptBlock(x917pool, 0, x917pool, 0);
+        System.arraycopy(x917pool, 0, buf, off, copy);
+        cipher.encryptBlock(x917pool, 0, x917pool, 0);
+        off += copy;
+        x917count++;
+      }
+  }
+
+  /**
+   * Add random data always immediately available into the random pool, such as
+   * the values of the eight asynchronous counters, the current time, the
+   * current memory usage, the calling thread name, and the current stack trace.
+   * <p>
+   * This method does not alter the quality counter, and is provided more to
+   * maintain randomness, not to seriously improve the current random state.
+   */
+  private void fastPoll()
+  {
+    byte b = 0;
+    for (int i = 0; i < SPINNER_COUNT; i++)
+      b ^= SPINNERS[i].counter;
+    addRandomByte(b);
+    addRandomByte((byte) System.currentTimeMillis());
+    addRandomByte((byte) Runtime.getRuntime().freeMemory());
+    String s = Thread.currentThread().getName();
+    if (s != null)
+      {
+        byte[] buf = s.getBytes();
+        addRandomBytes(buf, 0, buf.length);
+      }
+    ByteArrayOutputStream bout = new ByteArrayOutputStream(1024);
+    PrintStream pout = new PrintStream(bout);
+    Throwable t = new Throwable();
+    t.printStackTrace(pout);
+    pout.flush();
+    byte[] buf = bout.toByteArray();
+    addRandomBytes(buf, 0, buf.length);
+  }
+
+  private void slowPoll() throws LimitReachedException
+  {
+    if (Configuration.DEBUG)
+      log.fine("poller is alive? "
+               + (pollerThread == null ? false : pollerThread.isAlive()));
+    if (pollerThread == null || ! pollerThread.isAlive())
+      {
+        boolean interrupted = false;
+        pollerThread = new Thread(poller);
+        pollerThread.setDaemon(true);
+        pollerThread.setPriority(Thread.NORM_PRIORITY - 1);
+        pollerThread.start();
+        if (blocking)
+          try
+            {
+              pollerThread.join();
+            }
+          catch (InterruptedException ie)
+            {
+              interrupted = true;
+            }
+        // If the full slow poll has completed after we waited for it,
+        // and there in insufficient randomness, throw an exception.
+        if (! interrupted && blocking && quality < 100.0)
+          {
+            if (Configuration.DEBUG)
+              log.fine("insufficient quality: " + quality);
+            throw new LimitReachedException("insufficient randomness was polled");
+          }
+      }
+  }
+
+  protected void finalize() throws Throwable
+  {
+    if (poller != null && pollerThread != null && pollerThread.isAlive())
+      {
+        pollerThread.interrupt();
+        poller.stopUpdating();
+        pollerThread.interrupt();
+      }
+    Arrays.fill(pool, (byte) 0);
+    Arrays.fill(x917pool, (byte) 0);
+    Arrays.fill(buffer, (byte) 0);
+  }
+
+  /**
+   * A simple thread that constantly updates a byte counter. This class is used
+   * in a group of lowest-priority threads and the values of their counters
+   * (updated in competition with all other threads) is used as a source of
+   * entropy bits.
+   */
+  private static class Spinner
+      implements Runnable
+  {
+    protected byte counter;
+
+    private Spinner()
+    {
+    }
+
+    public void run()
+    {
+      while (true)
+        {
+          counter++;
+          try
+            {
+              Thread.sleep(100);
+            }
+          catch (InterruptedException ie)
+            {
+            }
+        }
+    }
+  }
+
+  private final class Poller
+      implements Runnable
+  {
+    private final List files;
+    private final List urls;
+    private final List progs;
+    private final List other;
+    private final CSPRNG pool;
+    private boolean running;
+
+    Poller(List files, List urls, List progs, List other, CSPRNG pool)
+    {
+      super();
+      this.files = Collections.unmodifiableList(files);
+      this.urls = Collections.unmodifiableList(urls);
+      this.progs = Collections.unmodifiableList(progs);
+      this.other = Collections.unmodifiableList(other);
+      this.pool = pool;
+    }
+
+    public void run()
+    {
+      running = true;
+      if (Configuration.DEBUG)
+        {
+          log.fine("files: " + files);
+          log.fine("URLs: " + urls);
+          log.fine("progs: " + progs);
+        }
+      Iterator files_it = files.iterator();
+      Iterator urls_it = urls.iterator();
+      Iterator prog_it = progs.iterator();
+      Iterator other_it = other.iterator();
+
+      while (files_it.hasNext() || urls_it.hasNext() || prog_it.hasNext()
+             || other_it.hasNext())
+        {
+          // There is enough random data. Go away.
+          if (pool.getQuality() >= 100.0 || ! running)
+            return;
+          if (files_it.hasNext())
+            try
+              {
+                List l = (List) files_it.next();
+                if (Configuration.DEBUG)
+                  log.fine(l.toString());
+                double qual = ((Double) l.get(0)).doubleValue();
+                int offset = ((Integer) l.get(1)).intValue();
+                int count = ((Integer) l.get(2)).intValue();
+                String src = (String) l.get(3);
+                InputStream in = new FileInputStream(src);
+                byte[] buf = new byte[count];
+                if (offset > 0)
+                  in.skip(offset);
+                int len = in.read(buf);
+                if (len >= 0)
+                  {
+                    pool.addRandomBytes(buf, 0, len);
+                    pool.addQuality(qual * ((double) len / (double) count));
+                  }
+                if (Configuration.DEBUG)
+                  log.fine("got " + len + " bytes from " + src);
+              }
+            catch (Exception x)
+              {
+                if (Configuration.DEBUG)
+                  log.throwing(this.getClass().getName(), "run", x);
+              }
+          if (pool.getQuality() >= 100.0 || ! running)
+            return;
+          if (urls_it.hasNext())
+            try
+              {
+                List l = (List) urls_it.next();
+                if (Configuration.DEBUG)
+                  log.fine(l.toString());
+                double qual = ((Double) l.get(0)).doubleValue();
+                int offset = ((Integer) l.get(1)).intValue();
+                int count = ((Integer) l.get(2)).intValue();
+                URL src = (URL) l.get(3);
+                InputStream in = src.openStream();
+                byte[] buf = new byte[count];
+                if (offset > 0)
+                  in.skip(offset);
+                int len = in.read(buf);
+                if (len >= 0)
+                  {
+                    pool.addRandomBytes(buf, 0, len);
+                    pool.addQuality(qual * ((double) len / (double) count));
+                  }
+                if (Configuration.DEBUG)
+                  log.fine("got " + len + " bytes from " + src);
+              }
+            catch (Exception x)
+              {
+                if (Configuration.DEBUG)
+                  log.throwing(this.getClass().getName(), "run", x);
+              }
+          if (pool.getQuality() >= 100.0 || ! running)
+            return;
+          Process proc = null;
+          if (prog_it.hasNext())
+            try
+              {
+                List l = (List) prog_it.next();
+                if (Configuration.DEBUG)
+                  log.finer(l.toString());
+                double qual = ((Double) l.get(0)).doubleValue();
+                int offset = ((Integer) l.get(1)).intValue();
+                int count = ((Integer) l.get(2)).intValue();
+                String src = (String) l.get(3);
+                proc = null;
+                proc = Runtime.getRuntime().exec(src);
+                InputStream in = proc.getInputStream();
+                byte[] buf = new byte[count];
+                if (offset > 0)
+                  in.skip(offset);
+                int len = in.read(buf);
+                if (len >= 0)
+                  {
+                    pool.addRandomBytes(buf, 0, len);
+                    pool.addQuality(qual * ((double) len / (double) count));
+                  }
+                proc.destroy();
+                proc.waitFor();
+                if (Configuration.DEBUG)
+                  log.fine("got " + len + " bytes from " + src);
+              }
+            catch (Exception x)
+              {
+                if (Configuration.DEBUG)
+                  log.throwing(this.getClass().getName(), "run", x);
+                try
+                  {
+                    if (proc != null)
+                      {
+                        proc.destroy();
+                        proc.waitFor();
+                      }
+                  }
+                catch (Exception ignored)
+                  {
+                  }
+              }
+          if (pool.getQuality() >= 100.0 || ! running)
+            return;
+          if (other_it.hasNext())
+            try
+              {
+                EntropySource src = (EntropySource) other_it.next();
+                byte[] buf = src.nextBytes();
+                if (pool == null)
+                  return;
+                pool.addRandomBytes(buf, 0, buf.length);
+                pool.addQuality(src.quality());
+                if (Configuration.DEBUG)
+                  log.fine("got " + buf.length + " bytes from " + src);
+              }
+            catch (Exception x)
+              {
+                if (Configuration.DEBUG)
+                  log.throwing(this.getClass().getName(), "run", x);
+              }
+        }
+    }
+
+    public void stopUpdating()
+    {
+      running = false;
+    }
+  }
+}