//
   //  ========================================================================
   //  Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.io.ssl;
  
  import java.io.IOException;
  import java.net.SocketException;
  import java.nio.ByteBuffer;
  import java.nio.channels.ClosedChannelException;
  import java.util.Arrays;
  import java.util.concurrent.Executor;
  import javax.net.ssl.SSLEngine;
  import javax.net.ssl.SSLEngineResult;
  import javax.net.ssl.SSLEngineResult.HandshakeStatus;
  import javax.net.ssl.SSLEngineResult.Status;
  import javax.net.ssl.SSLException;
  
  import org.eclipse.jetty.io.AbstractConnection;
  import org.eclipse.jetty.io.AbstractEndPoint;
  import org.eclipse.jetty.io.ByteBufferPool;
  import org.eclipse.jetty.io.Connection;
  import org.eclipse.jetty.io.EndPoint;
  import org.eclipse.jetty.io.EofException;
  import org.eclipse.jetty.io.FillInterest;
  import org.eclipse.jetty.io.RuntimeIOException;
  import org.eclipse.jetty.io.SelectChannelEndPoint;
  import org.eclipse.jetty.io.SocketBased;
  import org.eclipse.jetty.io.WriteFlusher;
  import org.eclipse.jetty.util.BufferUtil;
  import org.eclipse.jetty.util.Callback;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  /**
   * A Connection that acts as an interceptor between an EndPoint providing SSL encrypted data
   * and another consumer of an EndPoint (typically an {@link Connection} like HttpConnection) that
   * wants unencrypted data.
   * <p>
   * The connector uses an {@link EndPoint} (typically {@link SelectChannelEndPoint}) as
   * it's source/sink of encrypted data.   It then provides an endpoint via {@link #getDecryptedEndPoint()} to
   * expose a source/sink of unencrypted data to another connection (eg HttpConnection).
   * <p>
   * The design of this class is based on a clear separation between the passive methods, which do not block nor schedule any
   * asynchronous callbacks, and active methods that do schedule asynchronous callbacks.
   * <p>
   * The passive methods are {@link DecryptedEndPoint#fill(ByteBuffer)} and {@link DecryptedEndPoint#flush(ByteBuffer...)}. They make best
   * effort attempts to progress the connection using only calls to the encrypted {@link EndPoint#fill(ByteBuffer)} and {@link EndPoint#flush(ByteBuffer...)}
   * methods.  They will never block nor schedule any readInterest or write callbacks.   If a fill/flush cannot progress either because
   * of network congestion or waiting for an SSL handshake message, then the fill/flush will simply return with zero bytes filled/flushed.
   * Specifically, if a flush cannot proceed because it needs to receive a handshake message, then the flush will attempt to fill bytes from the
   * encrypted endpoint, but if insufficient bytes are read it will NOT call {@link EndPoint#fillInterested(Callback)}.
   * <p>
   * It is only the active methods : {@link DecryptedEndPoint#fillInterested(Callback)} and
   * {@link DecryptedEndPoint#write(Callback, ByteBuffer...)} that may schedule callbacks by calling the encrypted
   * {@link EndPoint#fillInterested(Callback)} and {@link EndPoint#write(Callback, ByteBuffer...)}
   * methods.  For normal data handling, the decrypted fillInterest method will result in an encrypted fillInterest and a decrypted
   * write will result in an encrypted write. However, due to SSL handshaking requirements, it is also possible for a decrypted fill
   * to call the encrypted write and for the decrypted flush to call the encrypted fillInterested methods.
   * <p>
   * MOST IMPORTANTLY, the encrypted callbacks from the active methods (#onFillable() and WriteFlusher#completeWrite()) do no filling or flushing
   * themselves.  Instead they simple make the callbacks to the decrypted callbacks, so that the passive encrypted fill/flush will
   * be called again and make another best effort attempt to progress the connection.
   *
   */
  public class SslConnection extends AbstractConnection
  {
      private static final Logger LOG = Log.getLogger(SslConnection.class);
      private static final boolean DEBUG = LOG.isDebugEnabled(); // Easy for the compiler to remove the code if DEBUG==false
      private static final ByteBuffer __FILL_CALLED_FLUSH= BufferUtil.allocate(0);
      private static final ByteBuffer __FLUSH_CALLED_FILL= BufferUtil.allocate(0);
      private final ByteBufferPool _bufferPool;
      private final SSLEngine _sslEngine;
      private final DecryptedEndPoint _decryptedEndPoint;
      private ByteBuffer _decryptedInput;
      private ByteBuffer _encryptedInput;
      private ByteBuffer _encryptedOutput;
      private final boolean _encryptedDirectBuffers = false;
      private final boolean _decryptedDirectBuffers = false;
      private final Runnable _runCompletWrite = new Runnable()
      {
          @Override
          public void run()
          {
              _decryptedEndPoint.getWriteFlusher().completeWrite();
         }
     };
     private boolean _renegotiationAllowed;
 
     public SslConnection(ByteBufferPool byteBufferPool, Executor executor, EndPoint endPoint, SSLEngine sslEngine)
     {
         // This connection does not execute calls to onfillable, so they will be called by the selector thread.
         // onfillable does not block and will only wakeup another thread to do the actual reading and handling.
         super(endPoint, executor, !EXECUTE_ONFILLABLE);
         this._bufferPool = byteBufferPool;
         this._sslEngine = sslEngine;
         this._decryptedEndPoint = newDecryptedEndPoint();
 
         if (endPoint instanceof SocketBased)
         {
             try
             {
                 ((SocketBased)endPoint).getSocket().setSoLinger(true, 30000);
             }
             catch (SocketException e)
             {
                 throw new RuntimeIOException(e);
             }
         }
     }
 
     protected DecryptedEndPoint newDecryptedEndPoint()
     {
         return new DecryptedEndPoint();
     }
 
     public SSLEngine getSSLEngine()
     {
         return _sslEngine;
     }
 
     public DecryptedEndPoint getDecryptedEndPoint()
     {
         return _decryptedEndPoint;
     }
 
     public boolean isRenegotiationAllowed()
     {
         return _renegotiationAllowed;
     }
 
     public void setRenegotiationAllowed(boolean renegotiationAllowed)
     {
         this._renegotiationAllowed = renegotiationAllowed;
     }
 
     @Override
     public void onOpen()
     {
         try
         {
             // Begin the handshake
             _sslEngine.beginHandshake();
             super.onOpen();
             getDecryptedEndPoint().getConnection().onOpen();
         }
         catch (SSLException x)
         {
             getEndPoint().close();
             throw new RuntimeIOException(x);
         }
     }
 
     @Override
     public void onClose()
     {
         _decryptedEndPoint.getConnection().onClose();
         super.onClose();
     }
 
     @Override
     public void close()
     {
         getDecryptedEndPoint().getConnection().close();
     }
 
     @Override
     public void onFillable()
     {
         // onFillable means that there are encrypted bytes ready to be filled.
         // however we do not fill them here on this callback, but instead wakeup
         // the decrypted readInterest and/or writeFlusher so that they will attempt
         // to do the fill and/or flush again and these calls will do the actually
         // filling.
 
         if (DEBUG)
             LOG.debug("onFillable enter {}", getEndPoint());
 
         // We have received a close handshake, close the end point to send FIN.
         if (_decryptedEndPoint.isInputShutdown())
             getEndPoint().close();
             
         // wake up whoever is doing the fill or the flush so they can
         // do all the filling, unwrapping, wrapping and flushing
         _decryptedEndPoint.getFillInterest().fillable();
 
         // If we are handshaking, then wake up any waiting write as well as it may have been blocked on the read
         synchronized(_decryptedEndPoint)
         {
             if (_decryptedEndPoint._flushRequiresFillToProgress)
             {
                 _decryptedEndPoint._flushRequiresFillToProgress = false;
                 getExecutor().execute(_runCompletWrite);
             }
         }
 
         if (DEBUG)
             LOG.debug("onFillable exit {}", getEndPoint());
     }
 
     @Override
     public void onFillInterestedFailed(Throwable cause)
     {
         // this means that the fill interest in encrypted bytes has failed.
         // However we do not handle that here on this callback, but instead wakeup
         // the decrypted readInterest and/or writeFlusher so that they will attempt
         // to do the fill and/or flush again and these calls will do the actually
         // handle the cause.
         _decryptedEndPoint.getFillInterest().onFail(cause);
 
         boolean failFlusher = false;
         synchronized(_decryptedEndPoint)
         {
             if (_decryptedEndPoint._flushRequiresFillToProgress)
             {
                 _decryptedEndPoint._flushRequiresFillToProgress = false;
                 failFlusher = true;
             }
         }
         if (failFlusher)
             _decryptedEndPoint.getWriteFlusher().onFail(cause);
     }
 
     @Override
     public String toString()
     {
         ByteBuffer b = _encryptedInput;
         int ei=b==null?-1:b.remaining();
         b = _encryptedOutput;
         int eo=b==null?-1:b.remaining();
         b = _decryptedInput;
         int di=b==null?-1:b.remaining();
 
         return String.format("SslConnection@%x{%s,eio=%d/%d,di=%d} -> %s",
                 hashCode(),
                 _sslEngine.getHandshakeStatus(),
                 ei,eo,di,
                 _decryptedEndPoint.getConnection());
     }
 
     public class DecryptedEndPoint extends AbstractEndPoint
     {
         private boolean _fillRequiresFlushToProgress;
         private boolean _flushRequiresFillToProgress;
         private boolean _cannotAcceptMoreAppDataToFlush;
         private boolean _handshaken;
         private boolean _underFlown;
 
         private final Callback _writeCallback = new Callback()
         {
             @Override
             public void succeeded()
             {
                 // This means that a write of encrypted data has completed.  Writes are done
                 // only if there is a pending writeflusher or a read needed to write
                 // data.  In either case the appropriate callback is passed on.
                 boolean fillable = false;
                 synchronized (DecryptedEndPoint.this)
                 {
                     if (DEBUG)
                         LOG.debug("write.complete {}", SslConnection.this.getEndPoint());
 
                     releaseEncryptedOutputBuffer();
 
                     _cannotAcceptMoreAppDataToFlush = false;
 
                     if (_fillRequiresFlushToProgress)
                     {
                         _fillRequiresFlushToProgress = false;
                         fillable = true;
                     }
                 }
                 if (fillable)
                     getFillInterest().fillable();
                 getExecutor().execute(_runCompletWrite);
             }
 
             @Override
             public void failed(Throwable x)
             {
                 // This means that a write of data has failed.  Writes are done
                 // only if there is an active writeflusher or a read needed to write
                 // data.  In either case the appropriate callback is passed on.
                 boolean failFiller = false;
                 synchronized (DecryptedEndPoint.this)
                 {
                     if (DEBUG)
                         LOG.debug("{} write.failed", SslConnection.this, x);
                     BufferUtil.clear(_encryptedOutput);
                     releaseEncryptedOutputBuffer();
 
                     _cannotAcceptMoreAppDataToFlush = false;
 
                     if (_fillRequiresFlushToProgress)
                     {
                         _fillRequiresFlushToProgress = false;
                         failFiller = true;
                     }
                 }
                 if (failFiller)
                     getFillInterest().onFail(x);
                 getWriteFlusher().onFail(x);
             }
         };
 
         public DecryptedEndPoint()
         {
             super(null,getEndPoint().getLocalAddress(), getEndPoint().getRemoteAddress());
             setIdleTimeout(getEndPoint().getIdleTimeout());
         }
 
         @Override
         protected FillInterest getFillInterest()
         {
             return super.getFillInterest();
         }
 
         @Override
         public void setIdleTimeout(long idleTimeout)
         {
             super.setIdleTimeout(idleTimeout);
             getEndPoint().setIdleTimeout(idleTimeout);
         }
 
         @Override
         protected WriteFlusher getWriteFlusher()
         {
             return super.getWriteFlusher();
         }
 
         @Override
         protected void onIncompleteFlush()
         {
             // This means that the decrypted endpoint write method was called and not
             // all data could be wrapped. So either we need to write some encrypted data,
             // OR if we are handshaking we need to read some encrypted data OR
             // if neither then we should just try the flush again.
             boolean flush = false;
             synchronized (DecryptedEndPoint.this)
             {
                 if (DEBUG)
                     LOG.debug("onIncompleteFlush {}", getEndPoint());
                 // If we have pending output data,
                 if (BufferUtil.hasContent(_encryptedOutput))
                 {
                     // write it
                     _cannotAcceptMoreAppDataToFlush = true;
                     getEndPoint().write(_writeCallback, _encryptedOutput);
                 }
                 // If we are handshaking and need to read,
                 else if (_sslEngine.getHandshakeStatus() == HandshakeStatus.NEED_UNWRAP)
                 {
                     // check if we are actually read blocked in order to write
                     _flushRequiresFillToProgress = true;
                     SslConnection.this.fillInterested();
                 }
                 else
                 {
                     flush = true;
                 }
             }
             if (flush)
             {
                 // If the output is closed,
                 if (isOutputShutdown())
                 {
                     // don't bother writing, just notify of close
                     getWriteFlusher().onClose();
                 }
                 // Else,
                 else
                 {
                     // try to flush what is pending
                     getWriteFlusher().completeWrite();
                 }
             }
         }
 
         @Override
         protected boolean needsFill() throws IOException
         {
             // This means that the decrypted data consumer has called the fillInterested
             // method on the DecryptedEndPoint, so we have to work out if there is
             // decrypted data to be filled or what callbacks to setup to be told when there
             // might be more encrypted data available to attempt another call to fill
 
             synchronized (DecryptedEndPoint.this)
             {
                 // Do we already have some app data, then app can fill now so return true
                 if (BufferUtil.hasContent(_decryptedInput))
                     return true;
 
                 // If we have no encrypted data to decrypt OR we have some, but it is not enough
                 if (BufferUtil.isEmpty(_encryptedInput) || _underFlown)
                 {
                     // We are not ready to read data
 
                     // Are we actually write blocked?
                     if (_fillRequiresFlushToProgress)
                     {
                         // we must be blocked trying to write before we can read
 
                         // Do we have data to write
                         if (BufferUtil.hasContent(_encryptedOutput))
                         {
                             // write it
                             _cannotAcceptMoreAppDataToFlush = true;
                             getEndPoint().write(_writeCallback, _encryptedOutput);
                         }
                         else
                         {
                             // we have already written the net data
                             // pretend we are readable so the wrap is done by next readable callback
                             _fillRequiresFlushToProgress = false;
                             return true;
                         }
                     }
                     else
                     {
                         // Normal readable callback
                         // Get called back on onfillable when then is more data to fill
                         SslConnection.this.fillInterested();
                     }
 
                     return false;
                 }
                 else
                 {
                     // We are ready to read data
                     return true;
                 }
             }
         }
 
         @Override
         public void setConnection(Connection connection)
         {
             if (connection instanceof AbstractConnection)
             {
                 AbstractConnection a = (AbstractConnection)connection;
                 if (a.getInputBufferSize()<_sslEngine.getSession().getApplicationBufferSize())
                     a.setInputBufferSize(_sslEngine.getSession().getApplicationBufferSize());
             }
             super.setConnection(connection);
         }
 
         public SslConnection getSslConnection()
         {
             return SslConnection.this;
         }
 
         @Override
         public synchronized int fill(ByteBuffer buffer) throws IOException
         {
             if (DEBUG)
                 LOG.debug("{} fill enter", SslConnection.this);
             try
             {
                 // Do we already have some decrypted data?
                 if (BufferUtil.hasContent(_decryptedInput))
                     return BufferUtil.flipPutFlip(_decryptedInput, buffer);
 
                 // We will need a network buffer
                 if (_encryptedInput == null)
                     _encryptedInput = _bufferPool.acquire(_sslEngine.getSession().getPacketBufferSize(), _encryptedDirectBuffers);
                 else
                     BufferUtil.compact(_encryptedInput);
 
                 // We also need an app buffer, but can use the passed buffer if it is big enough
                 ByteBuffer app_in;
                 if (BufferUtil.space(buffer) > _sslEngine.getSession().getApplicationBufferSize())
                     app_in = buffer;
                 else if (_decryptedInput == null)
                     app_in = _decryptedInput = _bufferPool.acquire(_sslEngine.getSession().getApplicationBufferSize(), _decryptedDirectBuffers);
                 else
                     app_in = _decryptedInput;
 
                 // loop filling and unwrapping until we have something
                 while (true)
                 {
                     // Let's try reading some encrypted data... even if we have some already.
                     int net_filled = getEndPoint().fill(_encryptedInput);
                     if (DEBUG)
                         LOG.debug("{} filled {} encrypted bytes", SslConnection.this, net_filled);
                     if (net_filled > 0)
                         _underFlown = false;
 
                     // Let's try the SSL thang even if we have no net data because in that
                     // case we want to fall through to the handshake handling
                     int pos = BufferUtil.flipToFill(app_in);
 
                     SSLEngineResult unwrapResult = _sslEngine.unwrap(_encryptedInput, app_in);
 
                     BufferUtil.flipToFlush(app_in, pos);
                     if (DEBUG)
                         LOG.debug("{} unwrap {}", SslConnection.this, unwrapResult);
 
                     Status unwrapResultStatus = unwrapResult.getStatus();
                     HandshakeStatus unwrapHandshakeStatus = unwrapResult.getHandshakeStatus();
                     HandshakeStatus handshakeStatus = _sslEngine.getHandshakeStatus();
 
                     // and deal with the results
                     switch (unwrapResultStatus)
                     {
                         case BUFFER_OVERFLOW:
                             throw new IllegalStateException();
 
                         case CLOSED:
                             // Dang! we have to care about the handshake state specially for close
                             switch (handshakeStatus)
                             {
                                 case NOT_HANDSHAKING:
                                     // We were not handshaking, so just tell the app we are closed
                                     return -1;
 
                                 case NEED_TASK:
                                     // run the task
                                     _sslEngine.getDelegatedTask().run();
                                     continue;
 
                                 case NEED_WRAP:
                                     // we need to send some handshake data (probably to send a close handshake).
                                     // but that will not enable any extra data to fill, so we just return -1
                                     // The wrapping can be done by any output drivers doing flushing or shutdown output.
                                     return -1;
                             }
                             throw new IllegalStateException();
 
                         default:
                             if (unwrapHandshakeStatus == HandshakeStatus.FINISHED && !_handshaken)
                             {
                                 _handshaken = true;
                                 if (DEBUG)
                                     LOG.debug("{} handshake completed client-side", SslConnection.this);
                             }
 
                             // Check whether renegotiation is allowed
                             if (_handshaken && handshakeStatus != HandshakeStatus.NOT_HANDSHAKING && !isRenegotiationAllowed())
                             {
                                 if (DEBUG)
                                     LOG.debug("{} renegotiation denied", SslConnection.this);
                                 closeInbound();
                                 return -1;
                             }
 
                             if (unwrapResultStatus == Status.BUFFER_UNDERFLOW)
                                 _underFlown = true;
 
                             // If bytes were produced, don't bother with the handshake status;
                             // pass the decrypted data to the application, which will perform
                             // another call to fill() or flush().
                             if (unwrapResult.bytesProduced() > 0)
                             {
                                 if (app_in == buffer)
                                     return unwrapResult.bytesProduced();
                                 return BufferUtil.flipPutFlip(_decryptedInput, buffer);
                             }
 
                             // Dang! we have to care about the handshake state
                             switch (handshakeStatus)
                             {
                                 case NOT_HANDSHAKING:
                                     // we just didn't read anything.
                                     if (net_filled < 0)
                                     {
                                         closeInbound();
                                         return -1;
                                     }
                                     return 0;
 
                                 case NEED_TASK:
                                     // run the task
                                     _sslEngine.getDelegatedTask().run();
                                     continue;
 
                                 case NEED_WRAP:
                                     // we need to send some handshake data
 
                                     // if we are called from flush
                                     if (buffer == __FLUSH_CALLED_FILL)
                                         return 0; // let it do the wrapping
 
                                     _fillRequiresFlushToProgress = true;
                                     flush(__FILL_CALLED_FLUSH);
                                     if (BufferUtil.isEmpty(_encryptedOutput))
                                     {
                                         // the flush completed so continue
                                         _fillRequiresFlushToProgress = false;
                                         continue;
                                     }
                                     return 0;
 
                                 case NEED_UNWRAP:
                                     // if we just filled some net data
                                     if (net_filled < 0)
                                     {
                                         closeInbound();
                                         return -1;
                                     }
                                     else if (net_filled > 0)
                                     {
                                         // maybe we will fill some more on a retry
                                         continue;
                                     }
                                     else
                                     {
                                         if (_encryptedInput.hasRemaining())
                                         {
                                             // if there are more encrypted bytes,
                                             // then we need to unwrap more, we don't
                                             // care if net_filled is zero
                                             continue;
                                         }
                                         // we need to wait for more net data
                                         return 0;
                                     }
 
                                 case FINISHED:
                                     throw new IllegalStateException();
                             }
                     }
                 }
             }
             catch (SSLException e)
             {
                 getEndPoint().close();
                 throw new EofException(e);
             }
             catch (Exception e)
             {
                 getEndPoint().close();
                 throw e;
             }
             finally
             {
                 // If we are handshaking, then wake up any waiting write as well as it may have been blocked on the read
                 if (_flushRequiresFillToProgress)
                 {
                     _flushRequiresFillToProgress = false;
                     getExecutor().execute(_runCompletWrite);
                 }
 
                 if (_encryptedInput != null && !_encryptedInput.hasRemaining())
                 {
                     _bufferPool.release(_encryptedInput);
                     _encryptedInput = null;
                 }
                 if (_decryptedInput != null && !_decryptedInput.hasRemaining())
                 {
                     _bufferPool.release(_decryptedInput);
                     _decryptedInput = null;
                 }
                 if (DEBUG)
                     LOG.debug("{} fill exit", SslConnection.this);
             }
         }
 
         private void closeInbound()
         {
             try
             {
                 _sslEngine.closeInbound();
             }
             catch (SSLException x)
             {
                 LOG.ignore(x);
             }
         }
 
         @Override
         public synchronized boolean flush(ByteBuffer... appOuts) throws IOException
         {
             // The contract for flush does not require that all appOuts bytes are written
             // or even that any appOut bytes are written!  If the connection is write block
             // or busy handshaking, then zero bytes may be taken from appOuts and this method
             // will return 0 (even if some handshake bytes were flushed and filled).
             // it is the applications responsibility to call flush again - either in a busy loop
             // or better yet by using EndPoint#write to do the flushing.
 
             if (DEBUG)
                 LOG.debug("{} flush enter {}", SslConnection.this, Arrays.toString(appOuts));
             int consumed=0;
             try
             {
                 if (_cannotAcceptMoreAppDataToFlush)
                 {
                     if (_sslEngine.isOutboundDone())
                         throw new EofException(new ClosedChannelException());
                     return false;
                 }
 
                 // We will need a network buffer
                 if (_encryptedOutput == null)
                     _encryptedOutput = _bufferPool.acquire(_sslEngine.getSession().getPacketBufferSize(), _encryptedDirectBuffers);
 
                 while (true)
                 {
                     // We call sslEngine.wrap to try to take bytes from appOut buffers and encrypt them into the _netOut buffer
                     BufferUtil.compact(_encryptedOutput);
                     int pos = BufferUtil.flipToFill(_encryptedOutput);
                     SSLEngineResult wrapResult = _sslEngine.wrap(appOuts, _encryptedOutput);
                     if (DEBUG)
                         LOG.debug("{} wrap {}", SslConnection.this, wrapResult);
                     BufferUtil.flipToFlush(_encryptedOutput, pos);
                     if (wrapResult.bytesConsumed()>0)
                         consumed+=wrapResult.bytesConsumed();
 
                     boolean allConsumed=true;
                     // clear empty buffers to prevent position creeping up the buffer
                     for (ByteBuffer b : appOuts)
                     {
                         if (BufferUtil.isEmpty(b))
                             BufferUtil.clear(b);
                         else
                             allConsumed=false;
                     }
 
                     Status wrapResultStatus = wrapResult.getStatus();
 
                     // and deal with the results returned from the sslEngineWrap
                     switch (wrapResultStatus)
                     {
                         case CLOSED:
                             // The SSL engine has close, but there may be close handshake that needs to be written
                             if (BufferUtil.hasContent(_encryptedOutput))
                             {
                                 _cannotAcceptMoreAppDataToFlush = true;
                                 getEndPoint().flush(_encryptedOutput);
                                 getEndPoint().shutdownOutput();
                                 // If we failed to flush the close handshake then we will just pretend that
                                 // the write has progressed normally and let a subsequent call to flush
                                 // (or WriteFlusher#onIncompleteFlushed) to finish writing the close handshake.
                                 // The caller will find out about the close on a subsequent flush or fill.
                                 if (BufferUtil.hasContent(_encryptedOutput))
                                     return false;
                             }
                             // otherwise we have written, and the caller will close the underlying connection
                             else
                             {
                                 getEndPoint().shutdownOutput();
                             }
                             return allConsumed;
 
                         case BUFFER_UNDERFLOW:
                             throw new IllegalStateException();
 
                         default:
                             if (DEBUG)
                                 LOG.debug("{} {} {}", this, wrapResultStatus, BufferUtil.toDetailString(_encryptedOutput));
 
                             if (wrapResult.getHandshakeStatus() == HandshakeStatus.FINISHED && !_handshaken)
                             {
                                 _handshaken = true;
                                 if (DEBUG)
                                     LOG.debug("{} handshake completed server-side", SslConnection.this);
                             }
 
                             HandshakeStatus handshakeStatus = _sslEngine.getHandshakeStatus();
 
                             // Check whether renegotiation is allowed
                             if (_handshaken && handshakeStatus != HandshakeStatus.NOT_HANDSHAKING && !isRenegotiationAllowed())
                             {
                                 if (DEBUG)
                                     LOG.debug("{} renegotiation denied", SslConnection.this);
                                 shutdownOutput();
                                 return allConsumed;
                             }
 
                             // if we have net bytes, let's try to flush them
                             if (BufferUtil.hasContent(_encryptedOutput))
                                 getEndPoint().flush(_encryptedOutput);
 
                             // But we also might have more to do for the handshaking state.
                             switch (handshakeStatus)
                             {
                                 case NOT_HANDSHAKING:
                                     // Return with the number of bytes consumed (which may be 0)
                                     return allConsumed && BufferUtil.isEmpty(_encryptedOutput);
 
                                 case NEED_TASK:
                                     // run the task and continue
                                     _sslEngine.getDelegatedTask().run();
                                     continue;
 
                                 case NEED_WRAP:
                                     // Hey we just wrapped! Oh well who knows what the sslEngine is thinking, so continue and we will wrap again
                                     continue;
 
                                 case NEED_UNWRAP:
                                     // Ah we need to fill some data so we can write.
                                     // So if we were not called from fill and the app is not reading anyway
                                     if (appOuts[0]!=__FILL_CALLED_FLUSH && !getFillInterest().isInterested())
                                     {
                                         // Tell the onFillable method that there might be a write to complete
                                         _flushRequiresFillToProgress = true;
                                         fill(__FLUSH_CALLED_FILL);
                                         // Check if after the fill() we need to wrap again
                                         if (handshakeStatus == HandshakeStatus.NEED_WRAP)
                                             continue;
                                     }
                                     return allConsumed&&BufferUtil.isEmpty(_encryptedOutput);
 
                                 case FINISHED:
                                     throw new IllegalStateException();
                             }
                     }
                 }
             }
             catch (Exception e)
             {
                 getEndPoint().close();
                 throw e;
             }
             finally
             {
                 if (DEBUG)
                     LOG.debug("{} flush exit, consumed {}", SslConnection.this, consumed);
                 releaseEncryptedOutputBuffer();
             }
         }
 
         private void releaseEncryptedOutputBuffer()
         {
             if (!Thread.holdsLock(DecryptedEndPoint.this))
                 throw new IllegalStateException();
             if (_encryptedOutput != null && !_encryptedOutput.hasRemaining())
             {
                 _bufferPool.release(_encryptedOutput);
                 _encryptedOutput = null;
             }
         }
 
         @Override
         public void shutdownOutput()
         {
             boolean ishut = isInputShutdown();
             if (DEBUG)
                 LOG.debug("{} shutdownOutput: oshut={}, ishut={}", SslConnection.this, isOutputShutdown(), ishut);
             if (ishut)
             {
                 // Aggressively close, since inbound close alert has already been processed
                 // and the TLS specification allows to close the connection directly, which
                 // is what most other implementations expect: a FIN rather than a TLS close
                 // reply. If a TLS close reply is sent, most implementation send a RST.
                 getEndPoint().close();
             }
             else
             {
                 try
                 {
                     _sslEngine.closeOutbound();
                     flush(BufferUtil.EMPTY_BUFFER); // Send close handshake
                     SslConnection.this.fillInterested(); // seek reply FIN or RST or close handshake
                 }
                 catch (Exception e)
                 {
                     LOG.ignore(e);
                     getEndPoint().close();
                 }
             }
         }
 
         @Override
         public boolean isOutputShutdown()
         {
             return _sslEngine.isOutboundDone() || getEndPoint().isOutputShutdown();
         }
 
         @Override
         public void close()
         {
             getEndPoint().close();
         }
 
         @Override
         public boolean isOpen()
         {
             return getEndPoint().isOpen();
         }
 
         @Override
         public Object getTransport()
         {
             return getEndPoint();
         }
 
         @Override
         public boolean isInputShutdown()
         {
             return _sslEngine.isInboundDone();
         }
 
         @Override
         public String toString()
         {
             return super.toString()+"->"+getEndPoint().toString();
         }
     }
 }