Back to index...

	/*
	* Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.jndi.ldap.ext;

	import java.io.InputStream;
	import java.io.OutputStream;
	import java.io.IOException;

	import java.security.Principal;
	import java.security.cert.X509Certificate;
	import java.security.cert.CertificateException;

	import javax.net.ssl.SSLSession;
	import javax.net.ssl.SSLSocket;
	import javax.net.ssl.SSLSocketFactory;
	import javax.net.ssl.SSLPeerUnverifiedException;
	import javax.net.ssl.HostnameVerifier;
	import sun.security.util.HostnameChecker;

	import javax.naming.ldap.*;
	import com.sun.jndi.ldap.Connection;

	/**
	* This class implements the LDAPv3 Extended Response for StartTLS as
	* defined in
	* <a href="http://www.ietf.org/rfc/rfc2830.txt">Lightweight Directory
	* Access Protocol (v3): Extension for Transport Layer Security</a>
	*
	* The object identifier for StartTLS is 1.3.6.1.4.1.1466.20037
	* and no extended response value is defined.
	*
	*<p>
	* The Start TLS extended request and response are used to establish
	* a TLS connection over the existing LDAP connection associated with
	* the JNDI context on which <tt>extendedOperation()</tt> is invoked.
	*
	* @see StartTlsRequest
	* @author Vincent Ryan
	*/
	final public class StartTlsResponseImpl extends StartTlsResponse {

	private static final boolean debug = false;

	/*
	* The dNSName type in a subjectAltName extension of an X.509 certificate
	*/
	private static final int DNSNAME_TYPE = 2;

	/*
	* The server's hostname.
	*/
	private transient String hostname = null;

	/*
	* The LDAP socket.
	*/
	private transient Connection ldapConnection = null;

	/*
	* The original input stream.
	*/
	private transient InputStream originalInputStream = null;

	/*
	* The original output stream.
	*/
	private transient OutputStream originalOutputStream = null;

	/*
	* The SSL socket.
	*/
	private transient SSLSocket sslSocket = null;

	/*
	* The SSL socket factories.
	*/
	private transient SSLSocketFactory defaultFactory = null;
	private transient SSLSocketFactory currentFactory = null;

	/*
	* The list of cipher suites to be enabled.
	*/
	private transient String[] suites = null;

	/*
	* The hostname verifier callback.
	*/
	private transient HostnameVerifier verifier = null;

	/*
	* The flag to indicate that the TLS connection is closed.
	*/
	private transient boolean isClosed = true;

	private static final long serialVersionUID = -1126624615143411328L;

	// public no-arg constructor required by JDK's Service Provider API.

	public StartTlsResponseImpl() {}

	/**
	* Overrides the default list of cipher suites enabled for use on the
	* TLS connection. The cipher suites must have already been listed by
	* <tt>SSLSocketFactory.getSupportedCipherSuites()</tt> as being supported.
	* Even if a suite has been enabled, it still might not be used because
	* the peer does not support it, or because the requisite certificates
	* (and private keys) are not available.
	*
	* @param suites The non-null list of names of all the cipher suites to
	* enable.
	* @see #negotiate
	*/
	public void setEnabledCipherSuites(String[] suites) {
	// The impl does accept null suites, although the spec requires
	// a non-null list.
	this.suites = suites == null ? null : suites.clone();
	}

	/**
	* Overrides the default hostname verifier used by <tt>negotiate()</tt>
	* after the TLS handshake has completed. If
	* <tt>setHostnameVerifier()</tt> has not been called before
	* <tt>negotiate()</tt> is invoked, <tt>negotiate()</tt>
	* will perform a simple case ignore match. If called after
	* <tt>negotiate()</tt>, this method does not do anything.
	*
	* @param verifier The non-null hostname verifier callback.
	* @see #negotiate
	*/
	public void setHostnameVerifier(HostnameVerifier verifier) {
	this.verifier = verifier;
	}

	/**
	* Negotiates a TLS session using the default SSL socket factory.
	* <p>
	* This method is equivalent to <tt>negotiate(null)</tt>.
	*
	* @return The negotiated SSL session
	* @throw IOException If an IO error was encountered while establishing
	* the TLS session.
	* @see #setEnabledCipherSuites
	* @see #setHostnameVerifier
	*/
	public SSLSession negotiate() throws IOException {

	return negotiate(null);
	}

	/**
	* Negotiates a TLS session using an SSL socket factory.
	* <p>
	* Creates an SSL socket using the supplied SSL socket factory and
	* attaches it to the existing connection. Performs the TLS handshake
	* and returns the negotiated session information.
	* <p>
	* If cipher suites have been set via <tt>setEnabledCipherSuites</tt>
	* then they are enabled before the TLS handshake begins.
	* <p>
	* Hostname verification is performed after the TLS handshake completes.
	* The default check performs a case insensitive match of the server's
	* hostname against that in the server's certificate. The server's
	* hostname is extracted from the subjectAltName in the server's
	* certificate (if present). Otherwise the value of the common name
	* attribute of the subject name is used. If a callback has
	* been set via <tt>setHostnameVerifier</tt> then that verifier is used if
	* the default check fails.
	* <p>
	* If an error occurs then the SSL socket is closed and an IOException
	* is thrown. The underlying connection remains intact.
	*
	* @param factory The possibly null SSL socket factory to use.
	* If null, the default SSL socket factory is used.
	* @return The negotiated SSL session
	* @throw IOException If an IO error was encountered while establishing
	* the TLS session.
	* @see #setEnabledCipherSuites
	* @see #setHostnameVerifier
	*/
	public SSLSession negotiate(SSLSocketFactory factory) throws IOException {

	if (isClosed && sslSocket != null) {
	throw new IOException("TLS connection is closed.");
	}

	if (factory == null) {
	factory = getDefaultFactory();
	}

	if (debug) {
	System.out.println("StartTLS: About to start handshake");
	}

	SSLSession sslSession = startHandshake(factory).getSession();

	if (debug) {
	System.out.println("StartTLS: Completed handshake");
	}

	SSLPeerUnverifiedException verifExcep = null;
	try {
	if (verify(hostname, sslSession)) {
	isClosed = false;
	return sslSession;
	}
	} catch (SSLPeerUnverifiedException e) {
	// Save to return the cause
	verifExcep = e;
	}
	if ((verifier != null) &&
	verifier.verify(hostname, sslSession)) {
	isClosed = false;
	return sslSession;
	}

	// Verification failed
	close();
	sslSession.invalidate();
	if (verifExcep == null) {
	verifExcep = new SSLPeerUnverifiedException(
	"hostname of the server '" + hostname +
	"' does not match the hostname in the " +
	"server's certificate.");
	}
	throw verifExcep;
	}

	/**
	* Closes the TLS connection gracefully and reverts back to the underlying
	* connection.
	*
	* @throw IOException If an IO error was encountered while closing the
	* TLS connection
	*/
	public void close() throws IOException {

	if (isClosed) {
	return;
	}

	if (debug) {
	System.out.println("StartTLS: replacing SSL " +
	"streams with originals");
	}

	// Replace SSL streams with the original streams
	ldapConnection.replaceStreams(
	originalInputStream, originalOutputStream, false);

	if (debug) {
	System.out.println("StartTLS: closing SSL Socket");
	}
	sslSocket.close();

	isClosed = true;
	}

	/**
	* Sets the connection for TLS to use. The TLS connection will be attached
	* to this connection.
	*
	* @param ldapConnection The non-null connection to use.
	* @param hostname The server's hostname. If null, the hostname used to
	* open the connection will be used instead.
	*/
	public void setConnection(Connection ldapConnection, String hostname) {
	this.ldapConnection = ldapConnection;
	this.hostname = (hostname == null \|\| hostname.isEmpty())
	? ldapConnection.host : hostname;
	originalInputStream = ldapConnection.inStream;
	originalOutputStream = ldapConnection.outStream;
	}

	/*
	* Returns the default SSL socket factory.
	*
	* @return The default SSL socket factory.
	* @throw IOException If TLS is not supported.
	*/
	private SSLSocketFactory getDefaultFactory() throws IOException {

	if (defaultFactory != null) {
	return defaultFactory;
	}

	return (defaultFactory =
	(SSLSocketFactory) SSLSocketFactory.getDefault());
	}

	/*
	* Start the TLS handshake and manipulate the input and output streams.
	*
	* @param factory The SSL socket factory to use.
	* @return The SSL socket.
	* @throw IOException If an exception occurred while performing the
	* TLS handshake.
	*/
	private SSLSocket startHandshake(SSLSocketFactory factory)
	throws IOException {

	if (ldapConnection == null) {
	throw new IllegalStateException("LDAP connection has not been set."
	+ " TLS requires an existing LDAP connection.");
	}

	if (factory != currentFactory) {
	// Create SSL socket layered over the existing connection
	sslSocket = (SSLSocket) factory.createSocket(ldapConnection.sock,
	ldapConnection.host, ldapConnection.port, false);
	currentFactory = factory;

	if (debug) {
	System.out.println("StartTLS: Created socket : " + sslSocket);
	}
	}

	if (suites != null) {
	sslSocket.setEnabledCipherSuites(suites);
	if (debug) {
	System.out.println("StartTLS: Enabled cipher suites");
	}
	}

	// Connection must be quite for handshake to proceed

	try {
	if (debug) {
	System.out.println(
	"StartTLS: Calling sslSocket.startHandshake");
	}
	sslSocket.startHandshake();
	if (debug) {
	System.out.println(
	"StartTLS: + Finished sslSocket.startHandshake");
	}

	// Replace original streams with the new SSL streams
	ldapConnection.replaceStreams(sslSocket.getInputStream(),
	sslSocket.getOutputStream(), true);
	if (debug) {
	System.out.println("StartTLS: Replaced IO Streams");
	}

	} catch (IOException e) {
	if (debug) {
	System.out.println("StartTLS: Got IO error during handshake");
	e.printStackTrace();
	}

	sslSocket.close();
	isClosed = true;
	throw e; // pass up exception
	}

	return sslSocket;
	}

	/*
	* Verifies that the hostname in the server's certificate matches the
	* hostname of the server.
	* The server's first certificate is examined. If it has a subjectAltName
	* that contains a dNSName then that is used as the server's hostname.
	* The server's hostname may contain a wildcard for its left-most name part.
	* Otherwise, if the certificate has no subjectAltName then the value of
	* the common name attribute of the subject name is used.
	*
	* @param hostname The hostname of the server.
	* @param session the SSLSession used on the connection to host.
	* @return true if the hostname is verified, false otherwise.
	*/

	private boolean verify(String hostname, SSLSession session)
	throws SSLPeerUnverifiedException {

	java.security.cert.Certificate[] certs = null;

	// if IPv6 strip off the "[]"
	if (hostname != null && hostname.startsWith("[") &&
	hostname.endsWith("]")) {
	hostname = hostname.substring(1, hostname.length() - 1);
	}
	try {
	HostnameChecker checker = HostnameChecker.getInstance(
	HostnameChecker.TYPE_LDAP);
	// Use ciphersuite to determine whether Kerberos is active.
	if (session.getCipherSuite().startsWith("TLS_KRB5")) {
	Principal principal = getPeerPrincipal(session);
	if (!HostnameChecker.match(hostname, principal)) {
	throw new SSLPeerUnverifiedException(
	"hostname of the kerberos principal:" + principal +
	" does not match the hostname:" + hostname);
	}
	} else { // X.509

	// get the subject's certificate
	certs = session.getPeerCertificates();
	X509Certificate peerCert;
	if (certs[0] instanceof java.security.cert.X509Certificate) {
	peerCert = (java.security.cert.X509Certificate) certs[0];
	} else {
	throw new SSLPeerUnverifiedException(
	"Received a non X509Certificate from the server");
	}
	checker.match(hostname, peerCert);
	}

	// no exception means verification passed
	return true;
	} catch (SSLPeerUnverifiedException e) {

	/*
	* The application may enable an anonymous SSL cipher suite, and
	* hostname verification is not done for anonymous ciphers
	*/
	String cipher = session.getCipherSuite();
	if (cipher != null && (cipher.indexOf("_anon_") != -1)) {
	return true;
	}
	throw e;
	} catch (CertificateException e) {

	/*
	* Pass up the cause of the failure
	*/
	throw(SSLPeerUnverifiedException)
	new SSLPeerUnverifiedException("hostname of the server '" +
	hostname +
	"' does not match the hostname in the " +
	"server's certificate.").initCause(e);
	}
	}

	/*
	* Get the peer principal from the session
	*/
	private static Principal getPeerPrincipal(SSLSession session)
	throws SSLPeerUnverifiedException {
	Principal principal;
	try {
	principal = session.getPeerPrincipal();
	} catch (AbstractMethodError e) {
	// if the JSSE provider does not support it, return null, since
	// we need it only for Kerberos.
	principal = null;
	}
	return principal;
	}
	}

Back to index...