/*

  * This file is part of dependency-check-core.

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  *

  * Copyright (c) 2014 Jeremy Long. All Rights Reserved.

  */

 package org.owasp.dependencycheck.utils;

 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;

 import org.apache.commons.lang3.StringUtils;

 import java.io.IOException;

 import java.net.Authenticator;

 import java.net.HttpURLConnection;

 import java.net.InetSocketAddress;

 import java.net.PasswordAuthentication;

 import java.net.Proxy;

 import java.net.SocketAddress;

 import java.net.URL;

 import java.net.URLConnection;

 import java.security.KeyManagementException;

 import java.security.NoSuchAlgorithmException;

 import javax.net.ssl.HttpsURLConnection;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * A URLConnection Factory to create new connections. This encapsulates several

  * configuration checks to ensure that the connection uses the correct proxy

  * settings.

  *

  * @author Jeremy Long

  */

 public final class URLConnectionFactory {

     /**

      * The logger.

      */

     private static final Logger LOGGER = LoggerFactory.getLogger(URLConnectionFactory.class);

     /**

      * Private constructor for this factory.

      */

     private URLConnectionFactory() {

     }

     /**

      * Utility method to create an HttpURLConnection. If the application is

      * configured to use a proxy this method will retrieve the proxy settings

      * and use them when setting up the connection.

      *

      * @param url the url to connect to

      * @return an HttpURLConnection

      * @throws URLConnectionFailureException thrown if there is an exception

      */

     @SuppressFBWarnings(value = "RCN_REDUNDANT_NULLCHECK_OF_NULL_VALUE", justification = "Just being extra safe")

     public static HttpURLConnection createHttpURLConnection(URL url) throws URLConnectionFailureException {

         HttpURLConnection conn = null;

         final String proxyUrl = Settings.getString(Settings.KEYS.PROXY_SERVER);

         try {

             if (proxyUrl != null && !matchNonProxy(url)) {

                 final int proxyPort = Settings.getInt(Settings.KEYS.PROXY_PORT);

                 final SocketAddress address = new InetSocketAddress(proxyUrl, proxyPort);

                 final String username = Settings.getString(Settings.KEYS.PROXY_USERNAME);

                 final String password = Settings.getString(Settings.KEYS.PROXY_PASSWORD);

                 if (username != null && password != null) {

                     final Authenticator auth = new Authenticator() {

                         @Override

                         public PasswordAuthentication getPasswordAuthentication() {

                             if (getRequestorType().equals(Authenticator.RequestorType.PROXY)) {

                                 return new PasswordAuthentication(username, password.toCharArray());

                             }

                             return super.getPasswordAuthentication();

                         }

                     };

                     Authenticator.setDefault(auth);

                 }

                 final Proxy proxy = new Proxy(Proxy.Type.HTTP, address);

                 conn = (HttpURLConnection) url.openConnection(proxy);

             } else {

                 conn = (HttpURLConnection) url.openConnection();

             }

             final int timeout = Settings.getInt(Settings.KEYS.CONNECTION_TIMEOUT, 10000);

             conn.setConnectTimeout(timeout);

             conn.setInstanceFollowRedirects(true);

         } catch (IOException ex) {

             if (conn != null) {

                 try {

                     conn.disconnect();

                 } finally {

                     conn = null;

                 }

             }

             throw new URLConnectionFailureException("Error getting connection.", ex);

         }

         configureTLS(url, conn);

         return conn;

     }

     /**

      * Check if hostname matches nonProxy settings

      *

      * @param url the url to connect to

      * @return matching result. true: match nonProxy

      */

     private static boolean matchNonProxy(final URL url) {

         final String host = url.getHost();

         // code partially from org.apache.maven.plugins.site.AbstractDeployMojo#getProxyInfo

         final String nonProxyHosts = Settings.getString(Settings.KEYS.PROXY_NON_PROXY_HOSTS);

         if (null != nonProxyHosts) {

             final String[] nonProxies = nonProxyHosts.split("(,)|(;)|(\\|)");

             for (final String nonProxyHost : nonProxies) {

                 //if ( StringUtils.contains( nonProxyHost, "*" ) )

                 if (null != nonProxyHost && nonProxyHost.contains("*")) {

                     // Handle wildcard at the end, beginning or middle of the nonProxyHost

                     final int pos = nonProxyHost.indexOf('*');

                     final String nonProxyHostPrefix = nonProxyHost.substring(0, pos);

                     final String nonProxyHostSuffix = nonProxyHost.substring(pos + 1);

                     // prefix*

                     if (!StringUtils.isEmpty(nonProxyHostPrefix) && host.startsWith(nonProxyHostPrefix) && StringUtils.isEmpty(nonProxyHostSuffix)) {

                         return true;

                     }

                     // *suffix

                     if (StringUtils.isEmpty(nonProxyHostPrefix) && !StringUtils.isEmpty(nonProxyHostSuffix) && host.endsWith(nonProxyHostSuffix)) {

                         return true;

                     }

                     // prefix*suffix

                     if (!StringUtils.isEmpty(nonProxyHostPrefix) && host.startsWith(nonProxyHostPrefix) && !StringUtils.isEmpty(nonProxyHostSuffix)

                             && host.endsWith(nonProxyHostSuffix)) {

                         return true;

                     }

                 } else if (host.equals(nonProxyHost)) {

                     return true;

                 }

             }

         }

         return false;

     }

     /**

      * Utility method to create an HttpURLConnection. The use of a proxy here is

      * optional as there may be cases where a proxy is configured but we don't

      * want to use it (for example, if there's an internal repository

      * configured)

      *

      * @param url the URL to connect to

      * @param proxy whether to use the proxy (if configured)

      * @return a newly constructed HttpURLConnection

      * @throws URLConnectionFailureException thrown if there is an exception

      */

     public static HttpURLConnection createHttpURLConnection(URL url, boolean proxy) throws URLConnectionFailureException {

         if (proxy) {

             return createHttpURLConnection(url);

         }

         HttpURLConnection conn = null;

         try {

             conn = (HttpURLConnection) url.openConnection();

             final int timeout = Settings.getInt(Settings.KEYS.CONNECTION_TIMEOUT, 10000);

             conn.setConnectTimeout(timeout);

             conn.setInstanceFollowRedirects(true);

         } catch (IOException ioe) {

             throw new URLConnectionFailureException("Error getting connection.", ioe);

         }

         configureTLS(url, conn);

         return conn;

     }

     /**

      * If the protocol is HTTPS, this will configure the cipher suites so that

      * connections can be made to the NVD, and others, using older versions of

      * Java.

      *

      * @param url the URL

      * @param conn the connection

      */

     private static void configureTLS(URL url, URLConnection conn) {

         if ("https".equals(url.getProtocol())) {

             try {

                 final HttpsURLConnection secCon = (HttpsURLConnection) conn;

                 final SSLSocketFactoryEx factory = new SSLSocketFactoryEx();

                 secCon.setSSLSocketFactory(factory);

             } catch (NoSuchAlgorithmException ex) {

                 LOGGER.debug("Unsupported algorithm in SSLSocketFactoryEx", ex);

             } catch (KeyManagementException ex) {

                 LOGGER.debug("Key management exception in SSLSocketFactoryEx", ex);

             }

         }

     }

 }