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Posted to dev@commons.apache.org by ol...@apache.org on 2003/05/17 17:40:00 UTC

cvs commit: jakarta-commons/httpclient/src/contrib/org/apache/commons/httpclient/contrib/ssl StrictSSLProtocolSocketFactory.java EasyX509TrustManager.java

olegk       2003/05/17 08:40:00

  Modified:    httpclient/src/contrib/org/apache/commons/httpclient/contrib/ssl
                        EasyX509TrustManager.java
  Added:       httpclient/src/contrib/org/apache/commons/httpclient/contrib/ssl
                        StrictSSLProtocolSocketFactory.java
  Log:
  Changelog:
  
  - StrictSSLProtocolSocketFactory class added to the 'httpclient.contrib.ssl' package. StrictSSLProtocolSocketFactory is a stricter version of SSLProtocolSocketFactory which will do host name verification in addition to the regular certificate validation. This mimics the behavior of Sun's HttpsConnection and should help preventing man-in-the-middle attacks.
  
  Contributed by Sebastian Hauer <ha...@psicode.com>
  Reviewed by Oleg Kalnichevski
  
  Revision  Changes    Path
  1.2       +2 -2      jakarta-commons/httpclient/src/contrib/org/apache/commons/httpclient/contrib/ssl/EasyX509TrustManager.java
  
  Index: EasyX509TrustManager.java
  ===================================================================
  RCS file: /home/cvs/jakarta-commons/httpclient/src/contrib/org/apache/commons/httpclient/contrib/ssl/EasyX509TrustManager.java,v
  retrieving revision 1.1
  retrieving revision 1.2
  diff -u -r1.1 -r1.2
  --- EasyX509TrustManager.java	16 Mar 2003 12:39:34 -0000	1.1
  +++ EasyX509TrustManager.java	17 May 2003 15:40:00 -0000	1.2
  @@ -124,9 +124,9 @@
        */
       public boolean isServerTrusted(X509Certificate[] certificates) {
           if ((certificates != null) && LOG.isDebugEnabled()) {
  -            LOG.debug("Number of server certificates: " + certificates.length);
  +            LOG.debug("Server certificate chain:");
               for (int i = 0; i < certificates.length; i++) {
  -                LOG.debug(certificates[i].toString());
  +                LOG.debug("X509Certificate[" + i + "]=" + certificates[i]);
               }
           }
           if ((certificates != null) && (certificates.length == 1)) {
  
  
  
  1.1                  jakarta-commons/httpclient/src/contrib/org/apache/commons/httpclient/contrib/ssl/StrictSSLProtocolSocketFactory.java
  
  Index: StrictSSLProtocolSocketFactory.java
  ===================================================================
  /*
   * $Header: /home/cvs/jakarta-commons/httpclient/src/contrib/org/apache/commons/httpclient/contrib/ssl/StrictSSLProtocolSocketFactory.java,v 1.1 2003/05/17 15:40:00 olegk Exp $
   * $Revision: 1.1 $
   * $Date: 2003/05/17 15:40:00 $
   *
   * ====================================================================
   *
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 1999-2003 The Apache Software Foundation.  All rights
   * reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "The Jakarta Project", "Commons", and "Apache Software
   *    Foundation" must not be used to endorse or promote products derived
   *    from this software without prior written permission. For written
   *    permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache"
   *    nor may "Apache" appear in their names without prior written
   *    permission of the Apache Group.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   * [Additional notices, if required by prior licensing conditions]
   *
   * Alternatively, the contents of this file may be used under the
   * terms of the GNU Lesser General Public License Version 2 or later
   * (the "LGPL"), in which case the provisions of the LGPL are 
   * applicable instead of those above.  See terms of LGPL at
   * <http://www.gnu.org/copyleft/lesser.txt>.
   * If you wish to allow use of your version of this file only under 
   * the terms of the LGPL and not to allow others to use your version
   * of this file under the Apache Software License, indicate your 
   * decision by deleting the provisions above and replace them with 
   * the notice and other provisions required by the LGPL.  If you do 
   * not delete the provisions above, a recipient may use your version 
   * of this file under either the Apache Software License or the LGPL.
   */
  
  package org.apache.commons.httpclient.contrib.ssl;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.Socket;
  import java.net.UnknownHostException;
  
  import javax.net.ssl.SSLPeerUnverifiedException;
  import javax.net.ssl.SSLSession;
  import javax.net.ssl.SSLSocket;
  import javax.net.ssl.SSLSocketFactory;
  import javax.security.cert.X509Certificate;
  
  import org.apache.commons.httpclient.protocol.SecureProtocolSocketFactory;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  
  /**
   * A <code>SecureProtocolSocketFactory</code> that uses JSSE to create
   * SSL sockets.  It will also support host name verification to help preventing
   * man-in-the-middle attacks.  Host name verification is turned <b>on</b> by
   * default but one will be able to turn it off, which might be a useful feature
   * during development.  Host name verification will make sure the SSL sessions
   * server host name matches with the the host name returned in the 
   * server certificates "Common Name" field of the "SubjectDN" entry.
   *
   * @author <a href="mailto:hauer@psicode.com">Sebastian Hauer</a>
   * @version 1.0
   * 
   * DISCLAIMER: HttpClient developers DO NOT actively support this component.
   * The component is provided as a reference material, which may be inappropriate
   * to be used without additional customization.
   */
  public class StrictSSLProtocolSocketFactory 
      implements SecureProtocolSocketFactory {
  
      /** Log object for this class. */
      private static final Log LOG = LogFactory.getLog(StrictSSLProtocolSocketFactory.class);
  
      /** Host name verify flag. */
      private boolean verifyHostname = true;
  
  
      /**
       * Constructor for StrictSSLProtocolSocketFactory.
       * @param verifyHostname  The host name verification flag. If set to 
       * <code>true</code> the SSL sessions server host name will be compared
       * to the host name returned in the server certificates "Common Name" 
       * field of the "SubjectDN" entry.  If these names do not match a
       * Exception is thrown to indicate this.  Enabling host name verification 
       * will help to prevent from man-in-the-middle attacks.  If set to 
       * <code>false</code> host name verification is turned off.
       * 
       * Code sample:
       *  
       *     <blockquote>
       *     Protocol stricthttps = new Protocol( 
       *         "https", new StrictSSLProtocolSocketFactory(true), 443);
       *
       *     HttpClient client = new HttpClient();
       *     client.getHostConfiguration().setHost("localhost", 443, stricthttps);
       *     </blockquote>
       *
       */
      public StrictSSLProtocolSocketFactory(boolean verifyHostname) {
          super();
          this.verifyHostname = verifyHostname;
      }
  
      /**
       * Constructor for StrictSSLProtocolSocketFactory.
       * Host name verification will be enabled by default.
       */
      public StrictSSLProtocolSocketFactory() {
          super();
      }
  
      /**
       * Set the host name verification flag.
       *
       * @param verifyHostname  The host name verification flag. If set to 
       * <code>true</code> the SSL sessions server host name will be compared
       * to the host name returned in the server certificates "Common Name" 
       * field of the "SubjectDN" entry.  If these names do not match a
       * Exception is thrown to indicate this.  Enabling host name verification 
       * will help to prevent from man-in-the-middle attacks.  If set to 
       * <code>false</code> host name verification is turned off.
       */
      public void setHostnameVerification(boolean verifyHostname) {
          this.verifyHostname = verifyHostname;
      }
  
      /**
       * Gets the status of the host name verification flag.
       *
       * @return  Host name verification flag.  Either <code>true</code> if host
       * name verification is turned on, or <code>false</code> if host name
       * verification is turned off.
       */
      public boolean getHostnameVerification() {
          return verifyHostname;
      }
  
      
      /**
       * @see SecureProtocolSocketFactory#createSocket(java.lang.String,int,java.net.InetAddress,int)
       */
      public Socket createSocket(String host, int port, 
                                 InetAddress clientHost, int clientPort)
          throws IOException, UnknownHostException {
          SSLSocketFactory sf = (SSLSocketFactory) SSLSocketFactory.getDefault();
          SSLSocket sslSocket = (SSLSocket) sf.createSocket(host, port, 
                                                            clientHost, 
                                                            clientPort);
          verifyHostname(sslSocket);
  
          return sslSocket;
      }
  
      /**
       * @see SecureProtocolSocketFactory#createSocket(java.lang.String,int)
       */
      public Socket createSocket(String host, int port)
          throws IOException, UnknownHostException {
          SSLSocketFactory sf = (SSLSocketFactory) SSLSocketFactory.getDefault();
          SSLSocket sslSocket = (SSLSocket) sf.createSocket(host, port);
          verifyHostname(sslSocket);
  
          return sslSocket;
      }
  
      /**
       * @see SecureProtocolSocketFactory#createSocket(java.net.Socket,java.lang.String,int,boolean)
       */
      public Socket createSocket(Socket socket, String host, int port, 
                                 boolean autoClose)
          throws IOException, UnknownHostException {
          SSLSocketFactory sf = (SSLSocketFactory) SSLSocketFactory.getDefault();
          SSLSocket sslSocket = (SSLSocket) sf.createSocket(socket, host, 
                                                            port, autoClose);
          verifyHostname(sslSocket);
  
          return sslSocket;
      }
  
  
      /**
       * Describe <code>verifyHostname</code> method here.
       *
       * @param socket a <code>SSLSocket</code> value
       * @exception SSLPeerUnverifiedException  If there are problems obtaining
       * the server certificates from the SSL session, or the server host name 
       * does not match with the "Common Name" in the server certificates 
       * SubjectDN.
       * @exception UnknownHostException  If we are not able to resolve
       * the SSL sessions returned server host name. 
       */
      private void verifyHostname(SSLSocket socket) 
          throws SSLPeerUnverifiedException, UnknownHostException {
          if (! verifyHostname) 
              return;
  
          SSLSession session = socket.getSession();
          String hostname = session.getPeerHost();
          try {
              InetAddress addr = InetAddress.getByName(hostname);
          } catch (UnknownHostException uhe) {
              throw new UnknownHostException("Could not resolve SSL sessions "
                                             + "server hostname: " + hostname);
          }
          
          X509Certificate[] certs = session.getPeerCertificateChain();
          if (certs == null || certs.length == 0) 
              throw new SSLPeerUnverifiedException("No server certificates found!");
          
          //get the servers DN in its string representation
          String dn = certs[0].getSubjectDN().getName();
  
          //might be useful to print out all certificates we receive from the
          //server, in case one has to debug a problem with the installed certs.
          if (LOG.isDebugEnabled()) {
              LOG.debug("Server certificate chain:");
              for (int i = 0; i < certs.length; i++) {
                  LOG.debug("X509Certificate[" + i + "]=" + certs[i]);
              }
          }
          //get the common name from the first cert
          String cn = getCN(dn);
          if (hostname.equalsIgnoreCase(cn)) {
              if (LOG.isDebugEnabled()) {
                  LOG.debug("Target hostname valid: " + cn);
              }
          } else {
              throw new SSLPeerUnverifiedException(
                  "HTTPS hostname invalid: expected '" + hostname + "', received '" + cn + "'");
          }
      }
  
  
      /**
       * Parses a X.500 distinguished name for the value of the 
       * "Common Name" field.
       * This is done a bit sloppy right now and should probably be done a bit
       * more according to <code>RFC 2253</code>.
       *
       * @param dn  a X.500 distinguished name.
       * @return the value of the "Common Name" field.
       */
      private String getCN(String dn) {
          int i = 0;
          i = dn.indexOf("CN=");
          if (i == -1) {
              return null;
          }
          //get the remaining DN without CN=
          dn = dn.substring(i + 3);  
          // System.out.println("dn=" + dn);
          char[] dncs = dn.toCharArray();
          for (i = 0; i < dncs.length; i++) {
              if (dncs[i] == ','  && i > 0 && dncs[i - 1] != '\\') {
                  break;
              }
          }
          return dn.substring(0, i);
      }
  }
  
  
  

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