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     */
018    package org.apache.hadoop.hdfs.web;
019    
020    import java.io.IOException;
021    import java.util.ArrayList;
022    import java.util.Enumeration;
023    import java.util.HashMap;
024    import java.util.Iterator;
025    import java.util.List;
026    import java.util.Map;
027    import java.util.Properties;
028    
029    import javax.servlet.FilterChain;
030    import javax.servlet.FilterConfig;
031    import javax.servlet.ServletException;
032    import javax.servlet.ServletRequest;
033    import javax.servlet.ServletResponse;
034    import javax.servlet.http.HttpServletRequest;
035    import javax.servlet.http.HttpServletRequestWrapper;
036    
037    import org.apache.hadoop.hdfs.web.resources.DelegationParam;
038    import org.apache.hadoop.security.UserGroupInformation;
039    import org.apache.hadoop.security.authentication.server.AuthenticationFilter;
040    import org.apache.hadoop.security.authentication.server.KerberosAuthenticationHandler;
041    import org.apache.hadoop.security.authentication.server.PseudoAuthenticationHandler;
042    
043    /**
044     * Subclass of {@link AuthenticationFilter} that
045     * obtains Hadoop-Auth configuration for webhdfs.
046     */
047    public 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        //For Pseudo Authentication, allow anonymous.
068        p.setProperty(PseudoAuthenticationHandler.ANONYMOUS_ALLOWED, "true");
069        //set cookie path
070        p.setProperty(COOKIE_PATH, "/");
071        return p;
072      }
073    
074      @Override
075      public void doFilter(ServletRequest request, ServletResponse response,
076          FilterChain filterChain) throws IOException, ServletException {
077        final HttpServletRequest httpRequest = toLowerCase((HttpServletRequest)request);
078        final String tokenString = httpRequest.getParameter(DelegationParam.NAME);
079        if (tokenString != null) {
080          //Token is present in the url, therefore token will be used for
081          //authentication, bypass kerberos authentication.
082          filterChain.doFilter(httpRequest, response);
083          return;
084        }
085        super.doFilter(httpRequest, response, filterChain);
086      }
087    
088      private static HttpServletRequest toLowerCase(final HttpServletRequest request) {
089        @SuppressWarnings("unchecked")
090        final Map<String, String[]> original = (Map<String, String[]>)request.getParameterMap();
091        if (!ParamFilter.containsUpperCase(original.keySet())) {
092          return request;
093        }
094    
095        final Map<String, List<String>> m = new HashMap<String, List<String>>();
096        for(Map.Entry<String, String[]> entry : original.entrySet()) {
097          final String key = entry.getKey().toLowerCase();
098          List<String> strings = m.get(key);
099          if (strings == null) {
100            strings = new ArrayList<String>();
101            m.put(key, strings);
102          }
103          for(String v : entry.getValue()) {
104            strings.add(v);
105          }
106        }
107    
108        return new HttpServletRequestWrapper(request) {
109          private Map<String, String[]> parameters = null;
110    
111          @Override
112          public Map<String, String[]> getParameterMap() {
113            if (parameters == null) {
114              parameters = new HashMap<String, String[]>();
115              for(Map.Entry<String, List<String>> entry : m.entrySet()) {
116                final List<String> a = entry.getValue();
117                parameters.put(entry.getKey(), a.toArray(new String[a.size()]));
118              }
119            }
120           return parameters;
121          }
122    
123          @Override
124          public String getParameter(String name) {
125            final List<String> a = m.get(name);
126            return a == null? null: a.get(0);
127          }
128          
129          @Override
130          public String[] getParameterValues(String name) {
131            return getParameterMap().get(name);
132          }
133    
134          @Override
135          public Enumeration<String> getParameterNames() {
136            final Iterator<String> i = m.keySet().iterator();
137            return new Enumeration<String>() {
138              @Override
139              public boolean hasMoreElements() {
140                return i.hasNext();
141              }
142              @Override
143              public String nextElement() {
144                return i.next();
145              }
146            };
147          }
148        };
149      }
150    }