1 /* 2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/auth/AuthSchemeBase.java $ 3 * $Revision: 653867 $ 4 * $Date: 2008-05-06 11:17:29 -0700 (Tue, 06 May 2008) $ 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.http.impl.auth; 32 33 import org.apache.http.FormattedHeader; 34 import org.apache.http.Header; 35 import org.apache.http.auth.AUTH; 36 import org.apache.http.auth.AuthScheme; 37 import org.apache.http.auth.MalformedChallengeException; 38 import org.apache.http.protocol.HTTP; 39 import org.apache.http.util.CharArrayBuffer; 40 41 /** 42 * Abstract authentication scheme class that serves as a basis 43 * for all authentication schemes supported by HttpClient. This class 44 * defines the generic way of parsing an authentication challenge. It 45 * does not make any assumptions regarding the format of the challenge 46 * nor does it impose any specific way of responding to that challenge. 47 * 48 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a> 49 */ 50 public abstract class AuthSchemeBase implements AuthScheme { 51 52 /** 53 * Flag whether authenticating against a proxy. 54 */ 55 private boolean proxy; 56 AuthSchemeBase()57 public AuthSchemeBase() { 58 super(); 59 } 60 61 /** 62 * Processes the given challenge token. Some authentication schemes 63 * may involve multiple challenge-response exchanges. Such schemes must be able 64 * to maintain the state information when dealing with sequential challenges 65 * 66 * @param header the challenge header 67 * 68 * @throws MalformedChallengeException is thrown if the authentication challenge 69 * is malformed 70 */ processChallenge(final Header header)71 public void processChallenge(final Header header) throws MalformedChallengeException { 72 if (header == null) { 73 throw new IllegalArgumentException("Header may not be null"); 74 } 75 String authheader = header.getName(); 76 if (authheader.equalsIgnoreCase(AUTH.WWW_AUTH)) { 77 this.proxy = false; 78 } else if (authheader.equalsIgnoreCase(AUTH.PROXY_AUTH)) { 79 this.proxy = true; 80 } else { 81 throw new MalformedChallengeException("Unexpected header name: " + authheader); 82 } 83 84 CharArrayBuffer buffer; 85 int pos; 86 if (header instanceof FormattedHeader) { 87 buffer = ((FormattedHeader) header).getBuffer(); 88 pos = ((FormattedHeader) header).getValuePos(); 89 } else { 90 String s = header.getValue(); 91 if (s == null) { 92 throw new MalformedChallengeException("Header value is null"); 93 } 94 buffer = new CharArrayBuffer(s.length()); 95 buffer.append(s); 96 pos = 0; 97 } 98 while (pos < buffer.length() && HTTP.isWhitespace(buffer.charAt(pos))) { 99 pos++; 100 } 101 int beginIndex = pos; 102 while (pos < buffer.length() && !HTTP.isWhitespace(buffer.charAt(pos))) { 103 pos++; 104 } 105 int endIndex = pos; 106 String s = buffer.substring(beginIndex, endIndex); 107 if (!s.equalsIgnoreCase(getSchemeName())) { 108 throw new MalformedChallengeException("Invalid scheme identifier: " + s); 109 } 110 111 parseChallenge(buffer, pos, buffer.length()); 112 } 113 parseChallenge( CharArrayBuffer buffer, int pos, int len)114 protected abstract void parseChallenge( 115 CharArrayBuffer buffer, int pos, int len) throws MalformedChallengeException; 116 117 /** 118 * Returns <code>true</code> if authenticating against a proxy, <code>false</code> 119 * otherwise. 120 * 121 * @return <code>true</code> if authenticating against a proxy, <code>false</code> 122 * otherwise 123 */ isProxy()124 public boolean isProxy() { 125 return this.proxy; 126 } 127 128 } 129