//
   //  ========================================================================
   //  Copyright (c) 1995-2016 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.util.ssl;
  
  import java.net.Socket;
  import java.security.Principal;
  import java.security.PrivateKey;
  import java.security.cert.X509Certificate;
  import java.util.Arrays;
  import java.util.Collection;
  
  import javax.net.ssl.SNIMatcher;
  import javax.net.ssl.SSLEngine;
  import javax.net.ssl.SSLSession;
  import javax.net.ssl.SSLSocket;
  import javax.net.ssl.X509ExtendedKeyManager;
  
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  
  /**
   * <p>A {@link X509ExtendedKeyManager} that selects a key with an alias
   * retrieved from SNI information, delegating other processing to a nested X509ExtendedKeyManager.</p>
   * <p>Can only be used on server side.</p>
   */
  public class SniX509ExtendedKeyManager extends X509ExtendedKeyManager
  {
      public static final String SNI_X509 = "org.eclipse.jetty.util.ssl.snix509";
      private static final String NO_MATCHERS = "no_matchers";
      private static final Logger LOG = Log.getLogger(SniX509ExtendedKeyManager.class);
  
      private final X509ExtendedKeyManager _delegate;
  
      public SniX509ExtendedKeyManager(X509ExtendedKeyManager keyManager)
      {
          _delegate = keyManager;
      }
  
      @Override
      public String chooseClientAlias(String[] keyType, Principal[] issuers, Socket socket)
      {
          return _delegate.chooseClientAlias(keyType,issuers,socket);
      }
  
      @Override
      public String chooseEngineClientAlias(String[] keyType, Principal[] issuers, SSLEngine engine)
      {
          return _delegate.chooseEngineClientAlias(keyType,issuers,engine);
      }
  
      protected String chooseServerAlias(String keyType, Principal[] issuers, Collection<SNIMatcher> matchers, SSLSession session)
      {
          // Look for the aliases that are suitable for the keytype and issuers
          String[] aliases = _delegate.getServerAliases(keyType,issuers);
          if (aliases==null || aliases.length==0)
              return null;
  
          // Look for the SNI information.
          String host=null;
          X509 x509=null;
          if (matchers!=null)
          {
              for (SNIMatcher m : matchers)
              {
                  if (m instanceof SslContextFactory.AliasSNIMatcher)
                  {
                      SslContextFactory.AliasSNIMatcher matcher = (SslContextFactory.AliasSNIMatcher)m;
                      host=matcher.getHost();
                      x509=matcher.getX509();
                      break;
                  }
              }
          }
  
          if (LOG.isDebugEnabled())
              LOG.debug("Matched {} with {} from {}",host,x509,Arrays.asList(aliases));
  
          // Check if the SNI selected alias is allowable
          if (x509!=null)
          {
              for (String a:aliases)
              {
                  if (a.equals(x509.getAlias()))
                 {
                     session.putValue(SNI_X509,x509);
                     return a;
                 }
             }
             return null;
         }
         return NO_MATCHERS;
     }
 
     @Override
     public String chooseServerAlias(String keyType, Principal[] issuers, Socket socket)
     {
         SSLSocket sslSocket = (SSLSocket)socket;
 
         String alias = chooseServerAlias(keyType,issuers,sslSocket.getSSLParameters().getSNIMatchers(),sslSocket.getHandshakeSession());
         if (alias==NO_MATCHERS)
             alias=_delegate.chooseServerAlias(keyType,issuers,socket);
         if (LOG.isDebugEnabled())
             LOG.debug("Chose alias {}/{} on {}",alias,keyType,socket);
         return alias;
     }
 
     @Override
     public String chooseEngineServerAlias(String keyType, Principal[] issuers, SSLEngine engine)
     {
         String alias = chooseServerAlias(keyType,issuers,engine.getSSLParameters().getSNIMatchers(),engine.getHandshakeSession());
         if (alias==NO_MATCHERS)
             alias=_delegate.chooseEngineServerAlias(keyType,issuers,engine);
         if (LOG.isDebugEnabled())
             LOG.debug("Chose alias {}/{} on {}",alias,keyType,engine);
         return alias;
     }
 
     @Override
     public X509Certificate[] getCertificateChain(String alias)
     {
         return _delegate.getCertificateChain(alias);
     }
 
     @Override
     public String[] getClientAliases(String keyType, Principal[] issuers)
     {
         return _delegate.getClientAliases(keyType,issuers);
     }
 
     @Override
     public PrivateKey getPrivateKey(String alias)
     {
         return _delegate.getPrivateKey(alias);
     }
 
     @Override
     public String[] getServerAliases(String keyType, Principal[] issuers)
     {
         return _delegate.getServerAliases(keyType,issuers);
     }
 }