/*

 * Copyright (c) 1995, 2013, 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 sun.net.www.protocol.http;

import java.util.Arrays;

import java.net.URL;

import java.net.URLConnection;

import java.net.ProtocolException;

import java.net.HttpRetryException;

import java.net.PasswordAuthentication;

import java.net.Authenticator;

import java.net.HttpCookie;

import java.net.InetAddress;

import java.net.UnknownHostException;

import java.net.SocketTimeoutException;

import java.net.SocketPermission;

import java.net.Proxy;

import java.net.ProxySelector;

import java.net.URI;

import java.net.InetSocketAddress;

import java.net.CookieHandler;

import java.net.ResponseCache;

import java.net.CacheResponse;

import java.net.SecureCacheResponse;

import java.net.CacheRequest;

import java.net.HttpURLPermission;

import java.net.Authenticator.RequestorType;

import java.security.AccessController;

import java.security.PrivilegedExceptionAction;

import java.security.PrivilegedActionException;

import java.io.*;

import java.net.*;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Date;

import java.util.Map;

import java.util.List;

import java.util.Locale;

import java.util.StringTokenizer;

import java.util.Iterator;

import java.util.HashSet;

import java.util.HashMap;

import java.util.Set;

import sun.net.*;

import sun.net.www.*;

import sun.net.www.http.HttpClient;

import sun.net.www.http.PosterOutputStream;

import sun.net.www.http.ChunkedInputStream;

import sun.net.www.http.ChunkedOutputStream;

import sun.util.logging.PlatformLogger;

import java.text.SimpleDateFormat;

import java.util.TimeZone;

import java.net.MalformedURLException;

import java.nio.ByteBuffer;

import static sun.net.www.protocol.http.AuthScheme.BASIC;

import static sun.net.www.protocol.http.AuthScheme.DIGEST;

import static sun.net.www.protocol.http.AuthScheme.NTLM;

import static sun.net.www.protocol.http.AuthScheme.NEGOTIATE;

import static sun.net.www.protocol.http.AuthScheme.KERBEROS;

import static sun.net.www.protocol.http.AuthScheme.UNKNOWN;

/**

 * A class to represent an HTTP connection to a remote object.

 */

public class HttpURLConnection extends java.net.HttpURLConnection {

    static String HTTP_CONNECT = "CONNECT";

    static final String version;

    public static final String userAgent;

    /* max # of allowed re-directs */

    static final int defaultmaxRedirects = 20;

    static final int maxRedirects;

    /* Not all servers support the (Proxy)-Authentication-Info headers.

     * By default, we don't require them to be sent

     */

    static final boolean validateProxy;

    static final boolean validateServer;

    private StreamingOutputStream strOutputStream;

    private final static String RETRY_MSG1 =

        "cannot retry due to proxy authentication, in streaming mode";

    private final static String RETRY_MSG2 =

        "cannot retry due to server authentication, in streaming mode";

    private final static String RETRY_MSG3 =

        "cannot retry due to redirection, in streaming mode";

    /*

     * System properties related to error stream handling:

     *

     * sun.net.http.errorstream.enableBuffering = <boolean>

     *

     * With the above system property set to true (default is false),

     * when the response code is >=400, the HTTP handler will try to

     * buffer the response body (up to a certain amount and within a

     * time limit). Thus freeing up the underlying socket connection

     * for reuse. The rationale behind this is that usually when the

     * server responds with a >=400 error (client error or server

     * error, such as 404 file not found), the server will send a

     * small response body to explain who to contact and what to do to

     * recover. With this property set to true, even if the

     * application doesn't call getErrorStream(), read the response

     * body, and then call close(), the underlying socket connection

     * can still be kept-alive and reused. The following two system

     * properties provide further control to the error stream

     * buffering behaviour.

     *

     * sun.net.http.errorstream.timeout = <int>

     *     the timeout (in millisec) waiting the error stream

     *     to be buffered; default is 300 ms

     *

     * sun.net.http.errorstream.bufferSize = <int>

     *     the size (in bytes) to use for the buffering the error stream;

     *     default is 4k

     */

    /* Should we enable buffering of error streams? */

    private static boolean enableESBuffer = false;

    /* timeout waiting for read for buffered error stream;

     */

    private static int timeout4ESBuffer = 0;

    /* buffer size for buffered error stream;

    */

    private static int bufSize4ES = 0;

    /*

     * Restrict setting of request headers through the public api

     * consistent with JavaScript XMLHttpRequest2 with a few

     * exceptions. Disallowed headers are silently ignored for

     * backwards compatibility reasons rather than throwing a

     * SecurityException. For example, some applets set the

     * Host header since old JREs did not implement HTTP 1.1.

     * Additionally, any header starting with Sec- is

     * disallowed.

     *

     * The following headers are allowed for historical reasons:

     *

     * Accept-Charset, Accept-Encoding, Cookie, Cookie2, Date,

     * Referer, TE, User-Agent, headers beginning with Proxy-.

     *

     * The following headers are allowed in a limited form:

     *

     * Connection: close

     *

     * See http://www.w3.org/TR/XMLHttpRequest2.

     */

    private static final boolean allowRestrictedHeaders;

    private static final Set<String> restrictedHeaderSet;

    private static final String[] restrictedHeaders = {

        /* Restricted by XMLHttpRequest2 */

        //"Accept-Charset",

        //"Accept-Encoding",

        "Access-Control-Request-Headers",

        "Access-Control-Request-Method",

        "Connection", /* close is allowed */

        "Content-Length",

        //"Cookie",

        //"Cookie2",

        "Content-Transfer-Encoding",

        //"Date",

        //"Expect",

        "Host",

        "Keep-Alive",

        "Origin",

        // "Referer",

        // "TE",

        "Trailer",

        "Transfer-Encoding",

        "Upgrade",

        //"User-Agent",

        "Via"

    };

    static {

        maxRedirects = java.security.AccessController.doPrivileged(

            new sun.security.action.GetIntegerAction(

                "http.maxRedirects", defaultmaxRedirects)).intValue();

        version = java.security.AccessController.doPrivileged(

                    new sun.security.action.GetPropertyAction("java.version"));

        String agent = java.security.AccessController.doPrivileged(

                    new sun.security.action.GetPropertyAction("http.agent"));

        if (agent == null) {

            agent = "Java/"+version;

        } else {

            agent = agent + " Java/"+version;

        }

        userAgent = agent;

        validateProxy = java.security.AccessController.doPrivileged(

                new sun.security.action.GetBooleanAction(

                    "http.auth.digest.validateProxy")).booleanValue();

        validateServer = java.security.AccessController.doPrivileged(

                new sun.security.action.GetBooleanAction(

                    "http.auth.digest.validateServer")).booleanValue();

        enableESBuffer = java.security.AccessController.doPrivileged(

                new sun.security.action.GetBooleanAction(

                    "sun.net.http.errorstream.enableBuffering")).booleanValue();

        timeout4ESBuffer = java.security.AccessController.doPrivileged(

                new sun.security.action.GetIntegerAction(

                    "sun.net.http.errorstream.timeout", 300)).intValue();

        if (timeout4ESBuffer <= 0) {

            timeout4ESBuffer = 300; // use the default

        }

        bufSize4ES = java.security.AccessController.doPrivileged(

                new sun.security.action.GetIntegerAction(

                    "sun.net.http.errorstream.bufferSize", 4096)).intValue();

        if (bufSize4ES <= 0) {

            bufSize4ES = 4096; // use the default

        }

        allowRestrictedHeaders = java.security.AccessController.doPrivileged(

                new sun.security.action.GetBooleanAction(

                    "sun.net.http.allowRestrictedHeaders")).booleanValue();

        if (!allowRestrictedHeaders) {

            restrictedHeaderSet = new HashSet<String>(restrictedHeaders.length);

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

                restrictedHeaderSet.add(restrictedHeaders[i].toLowerCase());

            }

        } else {

            restrictedHeaderSet = null;

        }

    }

    static final String httpVersion = "HTTP/1.1";

    static final String acceptString =

        "text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2";

    // the following http request headers should NOT have their values

    // returned for security reasons.

    private static final String[] EXCLUDE_HEADERS = {

            "Proxy-Authorization",

            "Authorization"

    };

    // also exclude system cookies when any might be set

    private static final String[] EXCLUDE_HEADERS2= {

            "Proxy-Authorization",

            "Authorization",

            "Cookie",

            "Cookie2"

    };

    protected HttpClient http;

    protected Handler handler;

    protected Proxy instProxy;

    private CookieHandler cookieHandler;

    private final ResponseCache cacheHandler;

    // the cached response, and cached response headers and body

    protected CacheResponse cachedResponse;

    private MessageHeader cachedHeaders;

    private InputStream cachedInputStream;

    /* output stream to server */

    protected PrintStream ps = null;

    /* buffered error stream */

    private InputStream errorStream = null;

    /* User set Cookies */

    private boolean setUserCookies = true;

    private String userCookies = null;

    private String userCookies2 = null;

    /* We only have a single static authenticator for now.

     * REMIND:  backwards compatibility with JDK 1.1.  Should be

     * eliminated for JDK 2.0.

     */

    @Deprecated

    private static HttpAuthenticator defaultAuth;

    /* all the headers we send

     * NOTE: do *NOT* dump out the content of 'requests' in the

     * output or stacktrace since it may contain security-sensitive

     * headers such as those defined in EXCLUDE_HEADERS.

     */

    private MessageHeader requests;

    /* The headers actually set by the user are recorded here also

     */

    private MessageHeader userHeaders;

    /* Headers and request method cannot be changed

     * once this flag is set in :-

     *     - getOutputStream()

     *     - getInputStream())

     *     - connect()

     * Access synchronized on this.

     */

    private boolean connecting = false;

    /* The following two fields are only used with Digest Authentication */

    String domain;      /* The list of authentication domains */

    DigestAuthentication.Parameters digestparams;

    /* Current credentials in use */

    AuthenticationInfo  currentProxyCredentials = null;

    AuthenticationInfo  currentServerCredentials = null;

    boolean             needToCheck = true;

    private boolean doingNTLM2ndStage = false; /* doing the 2nd stage of an NTLM server authentication */

    private boolean doingNTLMp2ndStage = false; /* doing the 2nd stage of an NTLM proxy authentication */

    /* try auth without calling Authenticator. Used for transparent NTLM authentication */

    private boolean tryTransparentNTLMServer = true;

    private boolean tryTransparentNTLMProxy = true;

    /* Used by Windows specific code */

    private Object authObj;

    /* Set if the user is manually setting the Authorization or Proxy-Authorization headers */

    boolean isUserServerAuth;

    boolean isUserProxyAuth;

    String serverAuthKey, proxyAuthKey;

    /* Progress source */

    protected ProgressSource pi;

    /* all the response headers we get back */

    private MessageHeader responses;

    /* the stream _from_ the server */

    private InputStream inputStream = null;

    /* post stream _to_ the server, if any */

    private PosterOutputStream poster = null;

    /* Indicates if the std. request headers have been set in requests. */

    private boolean setRequests=false;

    /* Indicates whether a request has already failed or not */

    private boolean failedOnce=false;

    /* Remembered Exception, we will throw it again if somebody

       calls getInputStream after disconnect */

    private Exception rememberedException = null;

    /* If we decide we want to reuse a client, we put it here */

    private HttpClient reuseClient = null;

    /* Tunnel states */

    public enum TunnelState {

        /* No tunnel */

        NONE,

        /* Setting up a tunnel */

        SETUP,

        /* Tunnel has been successfully setup */

        TUNNELING

    }

    private TunnelState tunnelState = TunnelState.NONE;

    /* Redefine timeouts from java.net.URLConnection as we need -1 to mean

     * not set. This is to ensure backward compatibility.

     */

    private int connectTimeout = NetworkClient.DEFAULT_CONNECT_TIMEOUT;

    private int readTimeout = NetworkClient.DEFAULT_READ_TIMEOUT;

    /* A permission converted from a HttpURLPermission */

    private SocketPermission socketPermission;

    /* Logging support */

    private static final PlatformLogger logger =

            PlatformLogger.getLogger("sun.net.www.protocol.http.HttpURLConnection");

    /*

     * privileged request password authentication

     *

     */

    private static PasswordAuthentication

    privilegedRequestPasswordAuthentication(

                            final String host,

                            final InetAddress addr,

                            final int port,

                            final String protocol,

                            final String prompt,

                            final String scheme,

                            final URL url,

                            final RequestorType authType) {

        return java.security.AccessController.doPrivileged(

            new java.security.PrivilegedAction<PasswordAuthentication>() {

                public PasswordAuthentication run() {

                        logger.finest("Requesting Authentication: host =" + host + " url = " + url);

                    }

                    PasswordAuthentication pass = Authenticator.requestPasswordAuthentication(

                        host, addr, port, protocol,

                        prompt, scheme, url, authType);

                        logger.finest("Authentication returned: " + (pass != null ? pass.toString() : "null"));

                    }

                    return pass;

                }

            });

    }

    private boolean isRestrictedHeader(String key, String value) {

        if (allowRestrictedHeaders) {

            return false;

        }

        key = key.toLowerCase();

        if (restrictedHeaderSet.contains(key)) {

            /*

             * Exceptions to restricted headers:

             *

             * Allow "Connection: close".

             */

            if (key.equals("connection") && value.equalsIgnoreCase("close")) {

                return false;

            }

            return true;

        } else if (key.startsWith("sec-")) {

            return true;

        }

        return false;

    }

    /*

     * Checks the validity of http message header and whether the header

     * is restricted and throws IllegalArgumentException if invalid or

     * restricted.

     */

    private boolean isExternalMessageHeaderAllowed(String key, String value) {

        checkMessageHeader(key, value);

        if (!isRestrictedHeader(key, value)) {

            return true;

        }

        return false;

    }

    /* Logging support */

    public static PlatformLogger getHttpLogger() {

        return logger;

    }

    /* Used for Windows NTLM implementation */

    public Object authObj() {

        return authObj;

    }

    public void authObj(Object authObj) {

        this.authObj = authObj;

    }

    /*

     * checks the validity of http message header and throws

     * IllegalArgumentException if invalid.

     */

    private void checkMessageHeader(String key, String value) {

        char LF = '\n';

        int index = key.indexOf(LF);

        if (index != -1) {

            throw new IllegalArgumentException(

                "Illegal character(s) in message header field: " + key);

        }

        else {

            if (value == null) {

                return;

            }

            index = value.indexOf(LF);

            while (index != -1) {

                index++;

                if (index < value.length()) {

                    char c = value.charAt(index);

                    if ((c==' ') || (c=='\t')) {

                        // ok, check the next occurrence

                        index = value.indexOf(LF, index);

                        continue;

                    }

                }

                throw new IllegalArgumentException(

                    "Illegal character(s) in message header value: " + value);

            }

        }

    }