/*

 * Copyright (c) 2001, 2016, 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,

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 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package sun.net.www.protocol.https;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.io.PrintStream;

import java.io.BufferedOutputStream;

import java.net.InetAddress;

import java.net.Socket;

import java.net.SocketException;

import java.net.URL;

import java.net.UnknownHostException;

import java.net.InetSocketAddress;

import java.net.Proxy;

import java.security.Principal;

import java.security.cert.*;

import java.util.Objects;

import java.util.StringTokenizer;

import java.util.Vector;

import javax.security.auth.x500.X500Principal;

import javax.net.ssl.*;

import sun.net.www.http.HttpClient;

import sun.net.www.protocol.http.AuthenticatorKeys;

import sun.net.www.protocol.http.HttpURLConnection;

import sun.security.action.*;

import sun.security.util.HostnameChecker;

import sun.security.ssl.SSLSocketImpl;

import sun.util.logging.PlatformLogger;

import static sun.net.www.protocol.http.HttpURLConnection.TunnelState.*;

/**

 * This class provides HTTPS client URL support, building on the standard

 * "sun.net.www" HTTP protocol handler.  HTTPS is the same protocol as HTTP,

 * but differs in the transport layer which it uses:  <UL>

 *

 *      <LI>There's a <em>Secure Sockets Layer</em> between TCP

 *      and the HTTP protocol code.

 *

 *      <LI>It uses a different default TCP port.

 *

 *      <LI>It doesn't use application level proxies, which can see and

 *      manipulate HTTP user level data, compromising privacy.  It uses

 *      low level tunneling instead, which hides HTTP protocol and data

 *      from all third parties.  (Traffic analysis is still possible).

 *

 *      <LI>It does basic server authentication, to protect

 *      against "URL spoofing" attacks.  This involves deciding

 *      whether the X.509 certificate chain identifying the server

 *      is trusted, and verifying that the name of the server is

 *      found in the certificate.  (The application may enable an

 *      anonymous SSL cipher suite, and such checks are not done

 *      for anonymous ciphers.)

 *

 *      <LI>It exposes key SSL session attributes, specifically the

 *      cipher suite in use and the server's X509 certificates, to

 *      application software which knows about this protocol handler.

 *

 *      </UL>

 *

 * <P> System properties used include:  <UL>

 *

 *      <LI><em>https.proxyHost</em> ... the host supporting SSL

 *      tunneling using the conventional CONNECT syntax

 *

 *      <LI><em>https.proxyPort</em> ... port to use on proxyHost

 *

 *      <LI><em>https.cipherSuites</em> ... comma separated list of

 *      SSL cipher suite names to enable.

 *

 *      <LI><em>http.nonProxyHosts</em> ...

 *

 *      </UL>

 *

 * @author David Brownell

 * @author Bill Foote

 */

// final for export control reasons (access to APIs); remove with care

final class HttpsClient extends HttpClient

    implements HandshakeCompletedListener

{

    // STATIC STATE and ACCESSORS THERETO

    // HTTPS uses a different default port number than HTTP.

    private static final int    httpsPortNumber = 443;

    // default HostnameVerifier class canonical name

    private static final String defaultHVCanonicalName =

            "javax.net.ssl.HttpsURLConnection.DefaultHostnameVerifier";

    /** Returns the default HTTPS port (443) */

    @Override

    protected int getDefaultPort() { return httpsPortNumber; }

    private HostnameVerifier hv;

    private SSLSocketFactory sslSocketFactory;

    // HttpClient.proxyDisabled will always be false, because we don't

    // use an application-level HTTP proxy.  We might tunnel through

    // our http proxy, though.

    // INSTANCE DATA

    // last negotiated SSL session

    private SSLSession  session;

    private String [] getCipherSuites() {

        //

        // If ciphers are assigned, sort them into an array.

        //

        String ciphers [];

        String cipherString =

                GetPropertyAction.privilegedGetProperty("https.cipherSuites");

        if (cipherString == null || "".equals(cipherString)) {

            ciphers = null;

        } else {

            StringTokenizer     tokenizer;

            Vector<String>      v = new Vector<String>();

            tokenizer = new StringTokenizer(cipherString, ",");

            while (tokenizer.hasMoreTokens())

                v.addElement(tokenizer.nextToken());

            ciphers = new String [v.size()];

            for (int i = 0; i < ciphers.length; i++)

                ciphers [i] = v.elementAt(i);

        }

        return ciphers;

    }

    private String [] getProtocols() {

        //

        // If protocols are assigned, sort them into an array.

        //

        String protocols [];

        String protocolString =

                GetPropertyAction.privilegedGetProperty("https.protocols");

        if (protocolString == null || "".equals(protocolString)) {

            protocols = null;

        } else {

            StringTokenizer     tokenizer;

            Vector<String>      v = new Vector<String>();

            tokenizer = new StringTokenizer(protocolString, ",");

            while (tokenizer.hasMoreTokens())

                v.addElement(tokenizer.nextToken());

            protocols = new String [v.size()];

            for (int i = 0; i < protocols.length; i++) {

                protocols [i] = v.elementAt(i);

            }

        }

        return protocols;

    }

    private String getUserAgent() {

        String userAgent =

                GetPropertyAction.privilegedGetProperty("https.agent");

        if (userAgent == null || userAgent.length() == 0) {

            userAgent = "JSSE";

        }

        return userAgent;

    }

    // CONSTRUCTOR, FACTORY

    /**

     * Create an HTTPS client URL.  Traffic will be tunneled through any

     * intermediate nodes rather than proxied, so that confidentiality

     * of data exchanged can be preserved.  However, note that all the

     * anonymous SSL flavors are subject to "person-in-the-middle"

     * attacks against confidentiality.  If you enable use of those

     * flavors, you may be giving up the protection you get through

     * SSL tunneling.

     *

     * Use New to get new HttpsClient. This constructor is meant to be

     * used only by New method. New properly checks for URL spoofing.

     *

     * @param URL https URL with which a connection must be established

     */

    private HttpsClient(SSLSocketFactory sf, URL url)

    throws IOException

    {

        // HttpClient-level proxying is always disabled,

        // because we override doConnect to do tunneling instead.

        this(sf, url, (String)null, -1);

    }

    /**

     *  Create an HTTPS client URL.  Traffic will be tunneled through

     * the specified proxy server.

     */

    HttpsClient(SSLSocketFactory sf, URL url, String proxyHost, int proxyPort)

        throws IOException {

        this(sf, url, proxyHost, proxyPort, -1);

    }

    /**

     *  Create an HTTPS client URL.  Traffic will be tunneled through

     * the specified proxy server, with a connect timeout

     */

    HttpsClient(SSLSocketFactory sf, URL url, String proxyHost, int proxyPort,

                int connectTimeout)

        throws IOException {

        this(sf, url,

             (proxyHost == null? null:

                HttpClient.newHttpProxy(proxyHost, proxyPort, "https")),

                connectTimeout);

    }

    /**

     *  Same as previous constructor except using a Proxy

     */

    HttpsClient(SSLSocketFactory sf, URL url, Proxy proxy,

                int connectTimeout)

        throws IOException {

        PlatformLogger logger = HttpURLConnection.getHttpLogger();

        if (logger.isLoggable(PlatformLogger.Level.FINEST)) {

             logger.finest("Creating new HttpsClient with url:" + url + " and proxy:" + proxy +

             " with connect timeout:" + connectTimeout);

        }

        this.proxy = proxy;

        setSSLSocketFactory(sf);

        this.proxyDisabled = true;

        this.host = url.getHost();

        this.url = url;

        port = url.getPort();

        if (port == -1) {

            port = getDefaultPort();

        }

        setConnectTimeout(connectTimeout);

        openServer();

    }

    // This code largely ripped off from HttpClient.New, and

    // it uses the same keepalive cache.

    static HttpClient New(SSLSocketFactory sf, URL url, HostnameVerifier hv,

                          HttpURLConnection httpuc)

            throws IOException {

        return HttpsClient.New(sf, url, hv, true, httpuc);

    }

    /** See HttpClient for the model for this method. */

    static HttpClient New(SSLSocketFactory sf, URL url,

            HostnameVerifier hv, boolean useCache,

            HttpURLConnection httpuc) throws IOException {

        return HttpsClient.New(sf, url, hv, (String)null, -1, useCache, httpuc);

    }

    /**

     * Get a HTTPS client to the URL.  Traffic will be tunneled through

     * the specified proxy server.

     */

    static HttpClient New(SSLSocketFactory sf, URL url, HostnameVerifier hv,

                           String proxyHost, int proxyPort,

                           HttpURLConnection httpuc) throws IOException {

        return HttpsClient.New(sf, url, hv, proxyHost, proxyPort, true, httpuc);

    }

    static HttpClient New(SSLSocketFactory sf, URL url, HostnameVerifier hv,

                           String proxyHost, int proxyPort, boolean useCache,

                           HttpURLConnection httpuc)

        throws IOException {

        return HttpsClient.New(sf, url, hv, proxyHost, proxyPort, useCache, -1,

                               httpuc);

    }

    static HttpClient New(SSLSocketFactory sf, URL url, HostnameVerifier hv,

                          String proxyHost, int proxyPort, boolean useCache,

                          int connectTimeout, HttpURLConnection httpuc)

        throws IOException {

        return HttpsClient.New(sf, url, hv,

                               (proxyHost == null? null :

                                HttpClient.newHttpProxy(proxyHost, proxyPort, "https")),

                               useCache, connectTimeout, httpuc);

    }

    static HttpClient New(SSLSocketFactory sf, URL url, HostnameVerifier hv,

                          Proxy p, boolean useCache,

                          int connectTimeout, HttpURLConnection httpuc)

        throws IOException

    {

        if (p == null) {

            p = Proxy.NO_PROXY;

        }

        PlatformLogger logger = HttpURLConnection.getHttpLogger();

        if (logger.isLoggable(PlatformLogger.Level.FINEST)) {

            logger.finest("Looking for HttpClient for URL " + url +

                " and proxy value of " + p);

        }

        HttpsClient ret = null;

        if (useCache) {

            /* see if one's already around */

            ret = (HttpsClient) kac.get(url, sf);

            if (ret != null && httpuc != null &&

                httpuc.streaming() &&

                httpuc.getRequestMethod() == "POST") {

                if (!ret.available())

                    ret = null;

            }

            if (ret != null) {

                String ak = httpuc == null ? AuthenticatorKeys.DEFAULT

                     : httpuc.getAuthenticatorKey();

                boolean compatible = ((ret.proxy != null && ret.proxy.equals(p)) ||

                    (ret.proxy == null && p == Proxy.NO_PROXY))

                     && Objects.equals(ret.getAuthenticatorKey(), ak);

                if (compatible) {

                    synchronized (ret) {

                        ret.cachedHttpClient = true;

                        assert ret.inCache;

                        ret.inCache = false;

                        if (httpuc != null && ret.needsTunneling())

                            httpuc.setTunnelState(TUNNELING);

                        if (logger.isLoggable(PlatformLogger.Level.FINEST)) {

                            logger.finest("KeepAlive stream retrieved from the cache, " + ret);

                        }

                    }

                } else {

                    // We cannot return this connection to the cache as it's

                    // KeepAliveTimeout will get reset. We simply close the connection.

                    // This should be fine as it is very rare that a connection

                    // to the same host will not use the same proxy.

                    synchronized(ret) {

                        if (logger.isLoggable(PlatformLogger.Level.FINEST)) {

                            logger.finest("Not returning this connection to cache: " + ret);

                        }

                        ret.inCache = false;

                        ret.closeServer();

                    }

                    ret = null;

                }

            }

        }

        if (ret == null) {

            ret = new HttpsClient(sf, url, p, connectTimeout);

            if (httpuc != null) {

                ret.authenticatorKey = httpuc.getAuthenticatorKey();

            }

        } else {

            SecurityManager security = System.getSecurityManager();

            if (security != null) {

                if (ret.proxy == Proxy.NO_PROXY || ret.proxy == null) {

                    security.checkConnect(InetAddress.getByName(url.getHost()).getHostAddress(), url.getPort());

                } else {

                    security.checkConnect(url.getHost(), url.getPort());

                }

            }

            ret.url = url;

        }

        ret.setHostnameVerifier(hv);

        return ret;

    }

    // METHODS

    void setHostnameVerifier(HostnameVerifier hv) {

        this.hv = hv;

    }

    void setSSLSocketFactory(SSLSocketFactory sf) {

        sslSocketFactory = sf;

    }

    SSLSocketFactory getSSLSocketFactory() {

        return sslSocketFactory;

    }

    /**

     * The following method, createSocket, is defined in NetworkClient

     * and overridden here so that the socket facroty is used to create

     * new sockets.

     */

    @Override

    protected Socket createSocket() throws IOException {

        try {

            return sslSocketFactory.createSocket();

        } catch (SocketException se) {

            //

            // bug 6771432

            // javax.net.SocketFactory throws a SocketException with an

            // UnsupportedOperationException as its cause to indicate that

            // unconnected sockets have not been implemented.

            //

            Throwable t = se.getCause();

            if (t != null && t instanceof UnsupportedOperationException) {

                return super.createSocket();

            } else {

                throw se;

            }

        }

    }

    @Override

    public boolean needsTunneling() {

        return (proxy != null && proxy.type() != Proxy.Type.DIRECT

                && proxy.type() != Proxy.Type.SOCKS);

    }

    @Override

    public void afterConnect() throws IOException, UnknownHostException {

        if (!isCachedConnection()) {

            SSLSocket s = null;

            SSLSocketFactory factory = sslSocketFactory;

            try {

                if (!(serverSocket instanceof SSLSocket)) {

                    s = (SSLSocket)factory.createSocket(serverSocket,

                                                        host, port, true);

                } else {

                    s = (SSLSocket)serverSocket;

                    if (s instanceof SSLSocketImpl) {

                        ((SSLSocketImpl)s).setHost(host);

                    }

                }

            } catch (IOException ex) {

                // If we fail to connect through the tunnel, try it

                // locally, as a last resort.  If this doesn't work,

                // throw the original exception.

                try {

                    s = (SSLSocket)factory.createSocket(host, port);

                } catch (IOException ignored) {

                    throw ex;

                }

            }

            //

            // Force handshaking, so that we get any authentication.

            // Register a handshake callback so our session state tracks any

            // later session renegotiations.

            //

            String [] protocols = getProtocols();

            String [] ciphers = getCipherSuites();

            if (protocols != null) {

                s.setEnabledProtocols(protocols);

            }

            if (ciphers != null) {

                s.setEnabledCipherSuites(ciphers);

            }

            s.addHandshakeCompletedListener(this);

            // We have two hostname verification approaches. One is in

            // SSL/TLS socket layer, where the algorithm is configured with

            // SSLParameters.setEndpointIdentificationAlgorithm(), and the

            // hostname verification is done by X509ExtendedTrustManager when

            // the algorithm is "HTTPS". The other one is in HTTPS layer,

            // where the algorithm is customized by

            // HttpsURLConnection.setHostnameVerifier(), and the hostname

            // verification is done by HostnameVerifier when the default

            // rules for hostname verification fail.

            //

            // The relationship between two hostname verification approaches

            // likes the following:

            //

            //               |             EIA algorithm

            //               +----------------------------------------------

            //               |     null      |   HTTPS    |   LDAP/other   |

            // -------------------------------------------------------------

            //     |         |1              |2           |3               |

            // HNV | default | Set HTTPS EIA | use EIA    | HTTPS          |

            //     |--------------------------------------------------------

            //     | non -   |4              |5           |6               |

            //     | default | HTTPS/HNV     | use EIA    | HTTPS/HNV      |

            // -------------------------------------------------------------

            //

            // Abbreviation:

            //     EIA: the endpoint identification algorithm in SSL/TLS

            //           socket layer

            //     HNV: the hostname verification object in HTTPS layer

            // Notes:

            //     case 1. default HNV and EIA is null

            //           Set EIA as HTTPS, hostname check done in SSL/TLS

            //           layer.

            //     case 2. default HNV and EIA is HTTPS

            //           Use existing EIA, hostname check done in SSL/TLS

            //           layer.