001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hdfs.web;
019
020import java.io.IOException;
021import java.util.ArrayList;
022import java.util.Enumeration;
023import java.util.HashMap;
024import java.util.Iterator;
025import java.util.List;
026import java.util.Map;
027import java.util.Properties;
028
029import javax.servlet.FilterChain;
030import javax.servlet.FilterConfig;
031import javax.servlet.ServletException;
032import javax.servlet.ServletRequest;
033import javax.servlet.ServletResponse;
034import javax.servlet.http.HttpServletRequest;
035import javax.servlet.http.HttpServletRequestWrapper;
036
037import org.apache.hadoop.hdfs.web.resources.DelegationParam;
038import org.apache.hadoop.security.UserGroupInformation;
039import org.apache.hadoop.security.authentication.server.AuthenticationFilter;
040import org.apache.hadoop.security.authentication.server.KerberosAuthenticationHandler;
041import org.apache.hadoop.security.authentication.server.PseudoAuthenticationHandler;
042
043/**
044 * Subclass of {@link AuthenticationFilter} that
045 * obtains Hadoop-Auth configuration for webhdfs.
046 */
047public class AuthFilter extends AuthenticationFilter {
048  private static final String CONF_PREFIX = "dfs.web.authentication.";
049
050  /**
051   * Returns the filter configuration properties,
052   * including the ones prefixed with {@link #CONF_PREFIX}.
053   * The prefix is removed from the returned property names.
054   *
055   * @param prefix parameter not used.
056   * @param config parameter contains the initialization values.
057   * @return Hadoop-Auth configuration properties.
058   * @throws ServletException 
059   */
060  @Override
061  protected Properties getConfiguration(String prefix, FilterConfig config)
062      throws ServletException {
063    final Properties p = super.getConfiguration(CONF_PREFIX, config);
064    // set authentication type
065    p.setProperty(AUTH_TYPE, UserGroupInformation.isSecurityEnabled()?
066        KerberosAuthenticationHandler.TYPE: PseudoAuthenticationHandler.TYPE);
067    // if not set, enable anonymous for pseudo authentication
068    if (p.getProperty(PseudoAuthenticationHandler.ANONYMOUS_ALLOWED) == null) {
069      p.setProperty(PseudoAuthenticationHandler.ANONYMOUS_ALLOWED, "true");
070    }
071    //set cookie path
072    p.setProperty(COOKIE_PATH, "/");
073    return p;
074  }
075
076  @Override
077  public void doFilter(ServletRequest request, ServletResponse response,
078      FilterChain filterChain) throws IOException, ServletException {
079    final HttpServletRequest httpRequest = toLowerCase((HttpServletRequest)request);
080    final String tokenString = httpRequest.getParameter(DelegationParam.NAME);
081    if (tokenString != null) {
082      //Token is present in the url, therefore token will be used for
083      //authentication, bypass kerberos authentication.
084      filterChain.doFilter(httpRequest, response);
085      return;
086    }
087    super.doFilter(httpRequest, response, filterChain);
088  }
089
090  private static HttpServletRequest toLowerCase(final HttpServletRequest request) {
091    @SuppressWarnings("unchecked")
092    final Map<String, String[]> original = (Map<String, String[]>)request.getParameterMap();
093    if (!ParamFilter.containsUpperCase(original.keySet())) {
094      return request;
095    }
096
097    final Map<String, List<String>> m = new HashMap<String, List<String>>();
098    for(Map.Entry<String, String[]> entry : original.entrySet()) {
099      final String key = entry.getKey().toLowerCase();
100      List<String> strings = m.get(key);
101      if (strings == null) {
102        strings = new ArrayList<String>();
103        m.put(key, strings);
104      }
105      for(String v : entry.getValue()) {
106        strings.add(v);
107      }
108    }
109
110    return new HttpServletRequestWrapper(request) {
111      private Map<String, String[]> parameters = null;
112
113      @Override
114      public Map<String, String[]> getParameterMap() {
115        if (parameters == null) {
116          parameters = new HashMap<String, String[]>();
117          for(Map.Entry<String, List<String>> entry : m.entrySet()) {
118            final List<String> a = entry.getValue();
119            parameters.put(entry.getKey(), a.toArray(new String[a.size()]));
120          }
121        }
122       return parameters;
123      }
124
125      @Override
126      public String getParameter(String name) {
127        final List<String> a = m.get(name);
128        return a == null? null: a.get(0);
129      }
130      
131      @Override
132      public String[] getParameterValues(String name) {
133        return getParameterMap().get(name);
134      }
135
136      @Override
137      public Enumeration<String> getParameterNames() {
138        final Iterator<String> i = m.keySet().iterator();
139        return new Enumeration<String>() {
140          @Override
141          public boolean hasMoreElements() {
142            return i.hasNext();
143          }
144          @Override
145          public String nextElement() {
146            return i.next();
147          }
148        };
149      }
150    };
151  }
152}