1 /* AuthInfo.java -- 2 Copyright (C) 2003, 2006 Free Software Foundation, Inc. 3 4 This file is a part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or (at 9 your option) any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19 USA 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package gnu.javax.crypto.sasl; 40 41 import gnu.java.security.Registry; 42 43 import java.util.ArrayList; 44 import java.util.Iterator; 45 import java.util.StringTokenizer; 46 47 /** 48 * A static class for creating {@link IAuthInfoProvider} providers. It 49 * transparently locates and uses any provider instances, based on the value 50 * assigned to the System property with the key 51 * <code>gnu.crypto.sasl.auth.info.provider.pkgs</code>. If more than one is 52 * specified they SHOULD be separated with a vertical bar character. Please note 53 * that the GNU provider is always added last to the list, disregarding whether 54 * it was mentioned or not in the value of that property, or if it that property 55 * was not defined. 56 */ 57 public class AuthInfo 58 { 59 private static final ArrayList factories = new ArrayList(); 60 static 61 { 62 IAuthInfoProviderFactory ours = new AuthInfoProviderFactory(); 63 // if SASL_AUTH_INFO_PROVIDER_PKGS is defined then parse it 64 String clazz; 65 String pkgs = System.getProperty(Registry.SASL_AUTH_INFO_PROVIDER_PKGS, 66 null); 67 if (pkgs != null) 68 { 69 for (StringTokenizer st = new StringTokenizer(pkgs, "|"); st.hasMoreTokens();) 70 { 71 clazz = st.nextToken().trim(); 72 if (! "gnu.javax.crypto.sasl".equals(clazz)) 73 { 74 clazz += ".AuthInfoProviderFactory"; 75 try 76 { 77 IAuthInfoProviderFactory factory = 78 (IAuthInfoProviderFactory) Class.forName(clazz).newInstance(); 79 factories.add(factory); 80 } 81 catch (ClassCastException ignored) 82 { 83 } 84 catch (ClassNotFoundException ignored) 85 { 86 } 87 catch (InstantiationException ignored) 88 { 89 } 90 catch (IllegalAccessException ignored) 91 { 92 } 93 } 94 } 95 } 96 // always add ours last; unless it's already there 97 if (!factories.contains(ours)) 98 factories.add(ours); 99 } 100 101 /** Trivial constructor to enforce Singleton pattern. */ AuthInfo()102 private AuthInfo() 103 { 104 super(); 105 } 106 107 /** 108 * A convenience method to return the authentication information provider for 109 * a designated SASL mechnanism. It goes through all the installed provider 110 * factories, one at a time, and attempts to return a new instance of the 111 * provider for the designated mechanism. It stops at the first factory 112 * returning a non-null provider. 113 * 114 * @param mechanism the name of a SASL mechanism. 115 * @return an implementation that provides {@link IAuthInfoProvider} for that 116 * mechanism; or <code>null</code> if none found. 117 */ getProvider(String mechanism)118 public static IAuthInfoProvider getProvider(String mechanism) 119 { 120 for (Iterator it = factories.iterator(); it.hasNext();) 121 { 122 IAuthInfoProviderFactory factory = (IAuthInfoProviderFactory) it.next(); 123 IAuthInfoProvider result = factory.getInstance(mechanism); 124 if (result != null) 125 return result; 126 } 127 return null; 128 } 129 } 130