content: /*
   * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/conn/ssl/AbstractVerifier.java $
   * $Revision: 653041 $
   * $Date: 2008-05-03 03:39:28 -0700 (Sat, 03 May 2008) $
   *
   * ====================================================================
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  
  package org.apache.http.conn.ssl;
  
  import java.util.regex.Pattern;
  
  import java.io.IOException;
  import java.security.cert.Certificate;
  import java.security.cert.CertificateParsingException;
  import java.security.cert.X509Certificate;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Locale;
  import java.util.logging.Logger;
  import java.util.logging.Level;
  
  import android.annotation.UnsupportedAppUsage;
  import javax.net.ssl.SSLException;
  import javax.net.ssl.SSLSession;
  import javax.net.ssl.SSLSocket;
  
  /**
   * Abstract base class for all standard {@link X509HostnameVerifier} 
   * implementations.
   * 
   * @author Julius Davies
   *
   * @deprecated Please use {@link java.net.URL#openConnection} instead.
   *     Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
   *     for further details.
   */
  @Deprecated
  public abstract class AbstractVerifier implements X509HostnameVerifier {
  
      private static final Pattern IPV4_PATTERN = Pattern.compile(
              "^(25[0-5]|2[0-4]\\d|[0-1]?\\d?\\d)(\\.(25[0-5]|2[0-4]\\d|[0-1]?\\d?\\d)){3}$");
  
      /**
       * This contains a list of 2nd-level domains that aren't allowed to
       * have wildcards when combined with country-codes.
       * For example: [*.co.uk].
       * <p/>
       * The [*.co.uk] problem is an interesting one.  Should we just hope
       * that CA's would never foolishly allow such a certificate to happen?
       * Looks like we're the only implementation guarding against this.
       * Firefox, Curl, Sun Java 1.4, 5, 6 don't bother with this check.
       */
      @UnsupportedAppUsage
      private final static String[] BAD_COUNTRY_2LDS =
            { "ac", "co", "com", "ed", "edu", "go", "gouv", "gov", "info",
              "lg", "ne", "net", "or", "org" };
  
      static {
          // Just in case developer forgot to manually sort the array.  :-)
          Arrays.sort(BAD_COUNTRY_2LDS);
      }
  
      public AbstractVerifier() {
          super();
      }
  
      public final void verify(String host, SSLSocket ssl)
            throws IOException {
          if(host == null) {
              throw new NullPointerException("host to verify is null");
          }
  
          SSLSession session = ssl.getSession();
          Certificate[] certs = session.getPeerCertificates();
          X509Certificate x509 = (X509Certificate) certs[0];
          verify(host, x509);
      }
  
      public final boolean verify(String host, SSLSession session) {
          try {
              Certificate[] certs = session.getPeerCertificates();
              X509Certificate x509 = (X509Certificate) certs[0];
              verify(host, x509);
              return true;
          }
          catch(SSLException e) {
              return false;
          }
      }
  
      public final void verify(String host, X509Certificate cert)
            throws SSLException {
          String[] cns = getCNs(cert);
          String[] subjectAlts = getDNSSubjectAlts(cert);
          verify(host, cns, subjectAlts);
      }
  
      public final void verify(final String host, final String[] cns,
                               final String[] subjectAlts,
                               final boolean strictWithSubDomains)
            throws SSLException {
  
          // Build the list of names we're going to check.  Our DEFAULT and
          // STRICT implementations of the HostnameVerifier only use the
          // first CN provided.  All other CNs are ignored.
          // (Firefox, wget, curl, Sun Java 1.4, 5, 6 all work this way).
          LinkedList<String> names = new LinkedList<String>();
          if(cns != null && cns.length > 0 && cns[0] != null) {
              names.add(cns[0]);
          }
          if(subjectAlts != null) {
              for (String subjectAlt : subjectAlts) {
                  if (subjectAlt != null) {
                      names.add(subjectAlt);
                  }
              }
          }
  
          if(names.isEmpty()) {
              String msg = "Certificate for <" + host + "> doesn't contain CN or DNS subjectAlt";
              throw new SSLException(msg);
          }
  
          // StringBuffer for building the error message.
          StringBuffer buf = new StringBuffer();
  
          // We're can be case-insensitive when comparing the host we used to
          // establish the socket to the hostname in the certificate.
          String hostName = host.trim().toLowerCase(Locale.ENGLISH);
          boolean match = false;
          for(Iterator<String> it = names.iterator(); it.hasNext();) {
              // Don't trim the CN, though!
              String cn = it.next();
              cn = cn.toLowerCase(Locale.ENGLISH);
              // Store CN in StringBuffer in case we need to report an error.
              buf.append(" <");
              buf.append(cn);
              buf.append('>');
              if(it.hasNext()) {
                  buf.append(" OR");
              }
  
              // The CN better have at least two dots if it wants wildcard
              // action.  It also can't be [*.co.uk] or [*.co.jp] or
              // [*.org.uk], etc...
              boolean doWildcard = cn.startsWith("*.") &&
                                   cn.indexOf('.', 2) != -1 &&
                                   acceptableCountryWildcard(cn) &&
                                   !isIPv4Address(host);
  
              if(doWildcard) {
                  match = hostName.endsWith(cn.substring(1));
                  if(match && strictWithSubDomains) {
                      // If we're in strict mode, then [*.foo.com] is not
                      // allowed to match [a.b.foo.com]
                      match = countDots(hostName) == countDots(cn);
                  }
              } else {
                  match = hostName.equals(cn);
              }
              if(match) {
                  break;
              }
          }
          if(!match) {
              throw new SSLException("hostname in certificate didn't match: <" + host + "> !=" + buf);
          }
      }
  
      public static boolean acceptableCountryWildcard(String cn) {
          int cnLen = cn.length();
          if(cnLen >= 7 && cnLen <= 9) {
              // Look for the '.' in the 3rd-last position:
              if(cn.charAt(cnLen - 3) == '.') {
                  // Trim off the [*.] and the [.XX].
                  String s = cn.substring(2, cnLen - 3);
                  // And test against the sorted array of bad 2lds:
                  int x = Arrays.binarySearch(BAD_COUNTRY_2LDS, s);
                  return x < 0;
              }
          }
          return true;
      }
  
      public static String[] getCNs(X509Certificate cert) {
          AndroidDistinguishedNameParser dnParser =
                  new AndroidDistinguishedNameParser(cert.getSubjectX500Principal());
          List<String> cnList = dnParser.getAllMostSpecificFirst("cn");
  
          if(!cnList.isEmpty()) {
              String[] cns = new String[cnList.size()];
              cnList.toArray(cns);
              return cns;
          } else {
              return null;
          }
      }
  
  
      /**
       * Extracts the array of SubjectAlt DNS names from an X509Certificate.
       * Returns null if there aren't any.
       * <p/>
       * Note:  Java doesn't appear able to extract international characters
       * from the SubjectAlts.  It can only extract international characters
       * from the CN field.
       * <p/>
       * (Or maybe the version of OpenSSL I'm using to test isn't storing the
       * international characters correctly in the SubjectAlts?).
       *
       * @param cert X509Certificate
       * @return Array of SubjectALT DNS names stored in the certificate.
       */
      public static String[] getDNSSubjectAlts(X509Certificate cert) {
          LinkedList<String> subjectAltList = new LinkedList<String>();
          Collection<List<?>> c = null;
          try {
              c = cert.getSubjectAlternativeNames();
          }
          catch(CertificateParsingException cpe) {
              Logger.getLogger(AbstractVerifier.class.getName())
                      .log(Level.FINE, "Error parsing certificate.", cpe);
          }
          if(c != null) {
              for (List<?> aC : c) {
                  List<?> list = aC;
                  int type = ((Integer) list.get(0)).intValue();
                  // If type is 2, then we've got a dNSName
                  if (type == 2) {
                      String s = (String) list.get(1);
                      subjectAltList.add(s);
                  }
              }
          }
          if(!subjectAltList.isEmpty()) {
              String[] subjectAlts = new String[subjectAltList.size()];
              subjectAltList.toArray(subjectAlts);
              return subjectAlts;
          } else {
              return null;
          }
      }
  
      /**
       * Counts the number of dots "." in a string.
       * @param s  string to count dots from
       * @return  number of dots
       */
      public static int countDots(final String s) {
          int count = 0;
          for(int i = 0; i < s.length(); i++) {
              if(s.charAt(i) == '.') {
                  count++;
              }
          }
          return count;
      }
  
      private static boolean isIPv4Address(final String input) {
          return IPV4_PATTERN.matcher(input).matches();
      }
  }
  