1 /* 2 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/auth/AuthPolicy.java,v 1.6 2004/05/13 04:02:00 mbecke Exp $ 3 * $Revision: 480424 $ 4 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $ 5 * 6 * ==================================================================== 7 * 8 * Licensed to the Apache Software Foundation (ASF) under one or more 9 * contributor license agreements. See the NOTICE file distributed with 10 * this work for additional information regarding copyright ownership. 11 * The ASF licenses this file to You under the Apache License, Version 2.0 12 * (the "License"); you may not use this file except in compliance with 13 * the License. You may obtain a copy of the License at 14 * 15 * http://www.apache.org/licenses/LICENSE-2.0 16 * 17 * Unless required by applicable law or agreed to in writing, software 18 * distributed under the License is distributed on an "AS IS" BASIS, 19 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 20 * See the License for the specific language governing permissions and 21 * limitations under the License. 22 * ==================================================================== 23 * 24 * This software consists of voluntary contributions made by many 25 * individuals on behalf of the Apache Software Foundation. For more 26 * information on the Apache Software Foundation, please see 27 * <http://www.apache.org/>. 28 * 29 */ 30 31 package org.apache.commons.httpclient.auth; 32 33 import java.util.ArrayList; 34 import java.util.HashMap; 35 import java.util.List; 36 37 import org.apache.commons.logging.Log; 38 import org.apache.commons.logging.LogFactory; 39 40 /** 41 * Authentication policy class. The Authentication policy provides corresponding 42 * authentication scheme interfrace for a given type of authorization challenge. 43 * <p>The following specifications are provided: 44 * <ul> 45 * <li><tt>Basic</tt>: Basic authentication scheme as defined in RFC2617 46 * (considered inherently insecure, but most widely supported) 47 * <li><tt>Digest</tt>: Digest authentication scheme as defined in RFC2617 48 * <li><tt>NTLM</tt>: The NTLM scheme is a proprietary Microsoft Windows 49 * Authentication protocol (considered to be the most secure among 50 * currently supported authentication schemes) 51 * </ul> 52 * 53 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a> 54 * 55 * @version $Revision: 480424 $ 56 * @since 3.0 57 */ 58 public abstract class AuthPolicy { 59 60 private static final HashMap SCHEMES = new HashMap(); 61 private static final ArrayList SCHEME_LIST = new ArrayList(); 62 63 /** 64 * The key used to look up the list of IDs of supported {@link AuthScheme 65 * authentication schemes} in their order of preference. The scheme IDs are 66 * stored in a {@link java.util.Collection} as {@link java.lang.String}s. 67 * 68 * <p> 69 * If several schemes are returned in the <tt>WWW-Authenticate</tt> 70 * or <tt>Proxy-Authenticate</tt> header, this parameter defines which 71 * {@link AuthScheme authentication schemes} takes precedence over others. 72 * The first item in the collection represents the most preferred 73 * {@link AuthScheme authentication scheme}, the last item represents the ID 74 * of the least preferred one. 75 * </p> 76 * 77 * @see org.apache.commons.httpclient.params.DefaultHttpParams 78 */ 79 public static final String AUTH_SCHEME_PRIORITY = "http.auth.scheme-priority"; 80 81 /** 82 * The NTLM scheme is a proprietary Microsoft Windows Authentication 83 * protocol (considered to be the most secure among currently supported 84 * authentication schemes). 85 */ 86 public static final String NTLM = "NTLM"; 87 88 /** 89 * Digest authentication scheme as defined in RFC2617. 90 */ 91 public static final String DIGEST = "Digest"; 92 93 /** 94 * Basic authentication scheme as defined in RFC2617 (considered inherently 95 * insecure, but most widely supported) 96 */ 97 public static final String BASIC = "Basic"; 98 99 static { AuthPolicy.registerAuthScheme(NTLM, NTLMScheme.class)100 AuthPolicy.registerAuthScheme(NTLM, NTLMScheme.class); AuthPolicy.registerAuthScheme(DIGEST, DigestScheme.class)101 AuthPolicy.registerAuthScheme(DIGEST, DigestScheme.class); AuthPolicy.registerAuthScheme(BASIC, BasicScheme.class)102 AuthPolicy.registerAuthScheme(BASIC, BasicScheme.class); 103 } 104 105 /** Log object. */ 106 protected static final Log LOG = LogFactory.getLog(AuthPolicy.class); 107 108 /** 109 * Registers a class implementing an {@link AuthScheme authentication scheme} with 110 * the given identifier. If a class with the given ID already exists it will be overridden. 111 * This ID is the same one used to retrieve the {@link AuthScheme authentication scheme} 112 * from {@link #getAuthScheme(String)}. 113 * 114 * <p> 115 * Please note that custom authentication preferences, if used, need to be updated accordingly 116 * for the new {@link AuthScheme authentication scheme} to take effect. 117 * </p> 118 * 119 * @param id the identifier for this scheme 120 * @param clazz the class to register 121 * 122 * @see #getAuthScheme(String) 123 * @see #AUTH_SCHEME_PRIORITY 124 */ registerAuthScheme(final String id, Class clazz)125 public static synchronized void registerAuthScheme(final String id, Class clazz) { 126 if (id == null) { 127 throw new IllegalArgumentException("Id may not be null"); 128 } 129 if (clazz == null) { 130 throw new IllegalArgumentException("Authentication scheme class may not be null"); 131 } 132 SCHEMES.put(id.toLowerCase(), clazz); 133 SCHEME_LIST.add(id.toLowerCase()); 134 } 135 136 /** 137 * Unregisters the class implementing an {@link AuthScheme authentication scheme} with 138 * the given ID. 139 * 140 * @param id the ID of the class to unregister 141 */ unregisterAuthScheme(final String id)142 public static synchronized void unregisterAuthScheme(final String id) { 143 if (id == null) { 144 throw new IllegalArgumentException("Id may not be null"); 145 } 146 SCHEMES.remove(id.toLowerCase()); 147 SCHEME_LIST.remove(id.toLowerCase()); 148 } 149 150 /** 151 * Gets the {@link AuthScheme authentication scheme} with the given ID. 152 * 153 * @param id the {@link AuthScheme authentication scheme} ID 154 * 155 * @return {@link AuthScheme authentication scheme} 156 * 157 * @throws IllegalStateException if a scheme with the ID cannot be found 158 */ getAuthScheme(final String id)159 public static synchronized AuthScheme getAuthScheme(final String id) 160 throws IllegalStateException { 161 162 if (id == null) { 163 throw new IllegalArgumentException("Id may not be null"); 164 } 165 Class clazz = (Class)SCHEMES.get(id.toLowerCase()); 166 if (clazz != null) { 167 try { 168 return (AuthScheme)clazz.newInstance(); 169 } catch (Exception e) { 170 LOG.error("Error initializing authentication scheme: " + id, e); 171 throw new IllegalStateException(id + 172 " authentication scheme implemented by " + 173 clazz.getName() + " could not be initialized"); 174 } 175 } else { 176 throw new IllegalStateException("Unsupported authentication scheme " + id); 177 } 178 } 179 180 /** 181 * Returns a list containing all registered {@link AuthScheme authentication 182 * schemes} in their default order. 183 * 184 * @return {@link AuthScheme authentication scheme} 185 */ getDefaultAuthPrefs()186 public static synchronized List getDefaultAuthPrefs() { 187 return (List)SCHEME_LIST.clone(); 188 } 189 } 190