    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.net.smtp;
    019
    020import java.io.BufferedWriter;
    021import java.io.IOException;
    022import java.io.InputStreamReader;
    023import java.io.OutputStreamWriter;
    024
    025import javax.net.ssl.HostnameVerifier;
    026import javax.net.ssl.KeyManager;
    027import javax.net.ssl.SSLContext;
    028import javax.net.ssl.SSLHandshakeException;
    029import javax.net.ssl.SSLSocket;
    030import javax.net.ssl.SSLSocketFactory;
    031import javax.net.ssl.TrustManager;
    032
    033import org.apache.commons.net.io.CRLFLineReader;
    034import org.apache.commons.net.util.SSLContextUtils;
    035import org.apache.commons.net.util.SSLSocketUtils;
    036
    037/**
    038 * SMTP over SSL processing. Copied from FTPSClient.java and modified to suit SMTP.
    039 * If implicit mode is selected (NOT the default), SSL/TLS negotiation starts right
    040 * after the connection has been established. In explicit mode (the default), SSL/TLS
    041 * negotiation starts when the user calls execTLS() and the server accepts the command.
    042 * Implicit usage:
    043 * <pre>
    044 *               SMTPSClient c = new SMTPSClient(true);
    045 *               c.connect("127.0.0.1", 465);
    046 * </pre>
    047 * Explicit usage:
    048 * <pre>
    049 *               SMTPSClient c = new SMTPSClient();
    050 *               c.connect("127.0.0.1", 25);
    051 *               if (c.execTLS()) {
    052 *                 // Rest of the commands here
    053 *               }
    054 * </pre>
    055 * <em>Warning</em>: the hostname is not verified against the certificate by default, use
    056 * {@link #setHostnameVerifier(HostnameVerifier)} or {@link #setEndpointCheckingEnabled(boolean)}
    057 * (on Java 1.7+) to enable verification.
    058 * @since 3.0
    059 */
    060public class SMTPSClient extends SMTPClient
    061{
    062    /** Default secure socket protocol name, like TLS */
    063    private static final String DEFAULT_PROTOCOL = "TLS";
    064
    065    /** The security mode. True - Implicit Mode / False - Explicit Mode. */
    066
    067    private final boolean isImplicit;
    068    /** The secure socket protocol to be used, like SSL/TLS. */
    069
    070    private final String protocol;
    071    /** The context object. */
    072
    073    private SSLContext context;
    074    /** The cipher suites. SSLSockets have a default set of these anyway,
    075        so no initialization required. */
    076
    077    private String[] suites;
    078    /** The protocol versions. */
    079
    080    private String[] protocols;
    081
    082    /** The {@link TrustManager} implementation, default null (i.e. use system managers). */
    083    private TrustManager trustManager;
    084
    085    /** The {@link KeyManager}, default null (i.e. use system managers). */
    086    private KeyManager keyManager; // seems not to be required
    087
    088    /** The {@link HostnameVerifier} to use post-TLS, default null (i.e. no verification). */
    089    private HostnameVerifier hostnameVerifier;
    090
    091    /** Use Java 1.7+ HTTPS Endpoint Identification Algorithim. */
    092    private boolean tlsEndpointChecking;
    093
    094    /**
    095     * Constructor for SMTPSClient, using {@link #DEFAULT_PROTOCOL} i.e. TLS
    096     * Sets security mode to explicit (isImplicit = false).
    097     */
    098    public SMTPSClient()
    099    {
    100        this(DEFAULT_PROTOCOL, false);
    101    }
    102
    103    /**
    104     * Constructor for SMTPSClient, using {@link #DEFAULT_PROTOCOL} i.e. TLS
    105     * @param implicit The security mode, {@code true} for implicit, {@code false} for explicit
    106     */
    107    public SMTPSClient(final boolean implicit)
    108    {
    109        this(DEFAULT_PROTOCOL, implicit);
    110    }
    111
    112    /**
    113     * Constructor for SMTPSClient, using explicit security mode.
    114     * @param proto the protocol.
    115     */
    116    public SMTPSClient(final String proto)
    117    {
    118        this(proto, false);
    119    }
    120
    121    /**
    122     * Constructor for SMTPSClient.
    123     * @param proto the protocol.
    124     * @param implicit The security mode, {@code true} for implicit, {@code false} for explicit
    125     */
    126    public SMTPSClient(final String proto, final boolean implicit)
    127    {
    128        protocol = proto;
    129        isImplicit = implicit;
    130    }
    131
    132    /**
    133     * Constructor for SMTPSClient.
    134     * @param proto the protocol.
    135     * @param implicit The security mode, {@code true} for implicit, {@code false} for explicit
    136     * @param encoding the encoding
    137     * @since 3.3
    138     */
    139    public SMTPSClient(final String proto, final boolean implicit, final String encoding)
    140    {
    141        super(encoding);
    142        protocol = proto;
    143        isImplicit = implicit;
    144    }
    145
    146    /**
    147     * Constructor for SMTPSClient, using {@link #DEFAULT_PROTOCOL} i.e. TLS
    148     * @param implicit The security mode, {@code true} for implicit, {@code false} for explicit
    149     * @param ctx A pre-configured SSL Context.
    150     */
    151    public SMTPSClient(final boolean implicit, final SSLContext ctx)
    152    {
    153        isImplicit = implicit;
    154        context = ctx;
    155        protocol = DEFAULT_PROTOCOL;
    156    }
    157
    158    /**
    159     * Constructor for SMTPSClient.
    160     * @param context A pre-configured SSL Context.
    161     * @see #SMTPSClient(boolean, SSLContext)
    162     */
    163    public SMTPSClient(final SSLContext context)
    164    {
    165        this(false, context);
    166    }
    167
    168    /**
    169     * Because there are so many connect() methods,
    170     * the _connectAction_() method is provided as a means of performing
    171     * some action immediately after establishing a connection,
    172     * rather than reimplementing all of the connect() methods.
    173     * @throws IOException If it is thrown by _connectAction_().
    174     * @see org.apache.commons.net.SocketClient#_connectAction_()
    175     */
    176    @Override
    177    protected void _connectAction_() throws IOException
    178    {
    179        // Implicit mode.
    180        if (isImplicit) {
    181            applySocketAttributes();
    182            performSSLNegotiation();
    183        }
    184        super._connectAction_();
    185        // Explicit mode - don't do anything. The user calls execTLS()
    186    }
    187
    188    /**
    189     * Performs a lazy init of the SSL context.
    190     * @throws IOException When could not initialize the SSL context.
    191     */
    192    private void initSSLContext() throws IOException
    193    {
    194        if (context == null)
    195        {
    196            context = SSLContextUtils.createSSLContext(protocol, getKeyManager(), getTrustManager());
    197        }
    198    }
    199
    200    /**
    201     * SSL/TLS negotiation. Acquires an SSL socket of a
    202     * connection and carries out handshake processing.
    203     * @throws IOException If server negotiation fails.
    204     */
    205    private void performSSLNegotiation() throws IOException
    206    {
    207        initSSLContext();
    208
    209        final SSLSocketFactory ssf = context.getSocketFactory();
    210        final String host = _hostname_ != null ? _hostname_ : getRemoteAddress().getHostAddress();
    211        final int port = getRemotePort();
    212        final SSLSocket socket =
    213            (SSLSocket) ssf.createSocket(_socket_, host, port, true);
    214        socket.setEnableSessionCreation(true);
    215        socket.setUseClientMode(true);
    216
    217        if (tlsEndpointChecking) {
    218            SSLSocketUtils.enableEndpointNameVerification(socket);
    219        }
    220        if (protocols != null) {
    221            socket.setEnabledProtocols(protocols);
    222        }
    223        if (suites != null) {
    224            socket.setEnabledCipherSuites(suites);
    225        }
    226        socket.startHandshake();
    227
    228        // TODO the following setup appears to duplicate that in the super class methods
    229        _socket_ = socket;
    230        _input_ = socket.getInputStream();
    231        _output_ = socket.getOutputStream();
    232        reader = new CRLFLineReader(
    233                        new InputStreamReader(_input_, encoding));
    234        writer = new BufferedWriter(
    235                        new OutputStreamWriter(_output_, encoding));
    236
    237        if (hostnameVerifier != null && !hostnameVerifier.verify(host, socket.getSession())) {
    238            throw new SSLHandshakeException("Hostname doesn't match certificate");
    239        }
    240    }
    241
    242    /**
    243     * Get the {@link KeyManager} instance.
    244     * @return The current {@link KeyManager} instance.
    245     */
    246    public KeyManager getKeyManager()
    247    {
    248        return keyManager;
    249    }
    250
    251    /**
    252     * Set a {@link KeyManager} to use.
    253     * @param newKeyManager The KeyManager implementation to set.
    254     * @see org.apache.commons.net.util.KeyManagerUtils
    255     */
    256    public void setKeyManager(final KeyManager newKeyManager)
    257    {
    258        keyManager = newKeyManager;
    259    }
    260
    261    /**
    262     * Controls which particular cipher suites are enabled for use on this
    263     * connection. Called before server negotiation.
    264     * @param cipherSuites The cipher suites.
    265     */
    266    public void setEnabledCipherSuites(final String[] cipherSuites)
    267    {
    268        suites = cipherSuites.clone();
    269    }
    270
    271    /**
    272     * Returns the names of the cipher suites which could be enabled
    273     * for use on this connection.
    274     * When the underlying {@link java.net.Socket Socket} is not an {@link SSLSocket} instance, returns null.
    275     * @return An array of cipher suite names, or <code>null</code>.
    276     */
    277    public String[] getEnabledCipherSuites()
    278    {
    279        if (_socket_ instanceof SSLSocket)
    280        {
    281            return ((SSLSocket)_socket_).getEnabledCipherSuites();
    282        }
    283        return null;
    284    }
    285
    286    /**
    287     * Controls which particular protocol versions are enabled for use on this
    288     * connection. I perform setting before a server negotiation.
    289     * @param protocolVersions The protocol versions.
    290     */
    291    public void setEnabledProtocols(final String[] protocolVersions)
    292    {
    293        protocols = protocolVersions.clone();
    294    }
    295
    296    /**
    297     * Returns the names of the protocol versions which are currently
    298     * enabled for use on this connection.
    299     * When the underlying {@link java.net.Socket Socket} is not an {@link SSLSocket} instance, returns null.
    300     * @return An array of protocols, or <code>null</code>.
    301     */
    302    public String[] getEnabledProtocols()
    303    {
    304        if (_socket_ instanceof SSLSocket)
    305        {
    306            return ((SSLSocket)_socket_).getEnabledProtocols();
    307        }
    308        return null;
    309    }
    310
    311    /**
    312     * The TLS command execution.
    313     * @throws IOException If an I/O error occurs while sending
    314     * the command or performing the negotiation.
    315     * @return TRUE if the command and negotiation succeeded.
    316     */
    317    public boolean execTLS() throws IOException
    318    {
    319        if (!SMTPReply.isPositiveCompletion(sendCommand("STARTTLS")))
    320        {
    321            return false;
    322            //throw new SSLException(getReplyString());
    323        }
    324        performSSLNegotiation();
    325        return true;
    326    }
    327
    328    /**
    329     * Get the currently configured {@link TrustManager}.
    330     * @return A TrustManager instance.
    331     */
    332    public TrustManager getTrustManager()
    333    {
    334        return trustManager;
    335    }
    336
    337    /**
    338     * Override the default {@link TrustManager} to use.
    339     * @param newTrustManager The TrustManager implementation to set.
    340     * @see org.apache.commons.net.util.TrustManagerUtils
    341     */
    342    public void setTrustManager(final TrustManager newTrustManager)
    343    {
    344        trustManager = newTrustManager;
    345    }
    346
    347    /**
    348     * Get the currently configured {@link HostnameVerifier}.
    349     * @return A HostnameVerifier instance.
    350     * @since 3.4
    351     */
    352    public HostnameVerifier getHostnameVerifier()
    353    {
    354        return hostnameVerifier;
    355    }
    356
    357    /**
    358     * Override the default {@link HostnameVerifier} to use.
    359     * @param newHostnameVerifier The HostnameVerifier implementation to set or <code>null</code> to disable.
    360     * @since 3.4
    361     */
    362    public void setHostnameVerifier(final HostnameVerifier newHostnameVerifier)
    363    {
    364        hostnameVerifier = newHostnameVerifier;
    365    }
    366
    367    /**
    368     * Return whether or not endpoint identification using the HTTPS algorithm
    369     * on Java 1.7+ is enabled. The default behavior is for this to be disabled.
    370     *
    371     * @return True if enabled, false if not.
    372     * @since 3.4
    373     */
    374    public boolean isEndpointCheckingEnabled()
    375    {
    376        return tlsEndpointChecking;
    377    }
    378
    379    /**
    380     * Automatic endpoint identification checking using the HTTPS algorithm
    381     * is supported on Java 1.7+. The default behavior is for this to be disabled.
    382     *
    383     * @param enable Enable automatic endpoint identification checking using the HTTPS algorithm on Java 1.7+.
    384     * @since 3.4
    385     */
    386    public void setEndpointCheckingEnabled(final boolean enable)
    387    {
    388        tlsEndpointChecking = enable;
    389    }
    390}
    391
    392/* kate: indent-width 4; replace-tabs on; */