/* * Copyright (c) 1999, 2006, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.security.sasl; import javax.security.auth.callback.CallbackHandler; import java.util.Enumeration; import java.util.Iterator; import java.util.Map; import java.util.Set; import java.util.HashSet; import java.util.Collections; import java.security.Provider; import java.security.Security; /** * A static class for creating SASL clients and servers. *

* This class defines the policy of how to locate, load, and instantiate * SASL clients and servers. *

* For example, an application or library gets a SASL client by doing * something like: *

 * SaslClient sc = Sasl.createSaslClient(mechanisms,
 *     authorizationId, protocol, serverName, props, callbackHandler);
 *
* It can then proceed to use the instance to create an authentication connection. *

* Similarly, a server gets a SASL server by using code that looks as follows: *

 * SaslServer ss = Sasl.createSaslServer(mechanism,
 *     protocol, serverName, props, callbackHandler);
 *
* * @since 1.5 * * @author Rosanna Lee * @author Rob Weltman */ public class Sasl { // Cannot create one of these private Sasl() { } /** * The name of a property that specifies the quality-of-protection to use. * The property contains a comma-separated, ordered list * of quality-of-protection values that the * client or server is willing to support. A qop value is one of * * * The order of the list specifies the preference order of the client or * server. If this property is absent, the default qop is "auth". * The value of this constant is "javax.security.sasl.qop". */ public static final String QOP = "javax.security.sasl.qop"; /** * The name of a property that specifies the cipher strength to use. * The property contains a comma-separated, ordered list * of cipher strength values that * the client or server is willing to support. A strength value is one of * * The order of the list specifies the preference order of the client or * server. An implementation should allow configuration of the meaning * of these values. An application may use the Java Cryptography * Extension (JCE) with JCE-aware mechanisms to control the selection of * cipher suites that match the strength values. *
* If this property is absent, the default strength is * "high,medium,low". * The value of this constant is "javax.security.sasl.strength". */ public static final String STRENGTH = "javax.security.sasl.strength"; /** * The name of a property that specifies whether the * server must authenticate to the client. The property contains * "true" if the server must * authenticate the to client; "false" otherwise. * The default is "false". *
The value of this constant is * "javax.security.sasl.server.authentication". */ public static final String SERVER_AUTH = "javax.security.sasl.server.authentication"; /** * The name of a property that specifies the maximum size of the receive * buffer in bytes of SaslClient/SaslServer. * The property contains the string representation of an integer. *
If this property is absent, the default size * is defined by the mechanism. *
The value of this constant is "javax.security.sasl.maxbuffer". */ public static final String MAX_BUFFER = "javax.security.sasl.maxbuffer"; /** * The name of a property that specifies the maximum size of the raw send * buffer in bytes of SaslClient/SaslServer. * The property contains the string representation of an integer. * The value of this property is negotiated between the client and server * during the authentication exchange. *
The value of this constant is "javax.security.sasl.rawsendsize". */ public static final String RAW_SEND_SIZE = "javax.security.sasl.rawsendsize"; /** * The name of a property that specifies whether to reuse previously * authenticated session information. The property contains "true" if the * mechanism implementation may attempt to reuse previously authenticated * session information; it contains "false" if the implementation must * not reuse previously authenticated session information. A setting of * "true" serves only as a hint: it does not necessarily entail actual * reuse because reuse might not be possible due to a number of reasons, * including, but not limited to, lack of mechanism support for reuse, * expiration of reusable information, and the peer's refusal to support * reuse. * * The property's default value is "false". The value of this constant * is "javax.security.sasl.reuse". * * Note that all other parameters and properties required to create a * SASL client/server instance must be provided regardless of whether * this property has been supplied. That is, you cannot supply any less * information in anticipation of reuse. * * Mechanism implementations that support reuse might allow customization * of its implementation, for factors such as cache size, timeouts, and * criteria for reuseability. Such customizations are * implementation-dependent. */ public static final String REUSE = "javax.security.sasl.reuse"; /** * The name of a property that specifies * whether mechanisms susceptible to simple plain passive attacks (e.g., * "PLAIN") are not permitted. The property * contains "true" if such mechanisms are not permitted; * "false" if such mechanisms are permitted. * The default is "false". *
The value of this constant is * "javax.security.sasl.policy.noplaintext". */ public static final String POLICY_NOPLAINTEXT = "javax.security.sasl.policy.noplaintext"; /** * The name of a property that specifies whether * mechanisms susceptible to active (non-dictionary) attacks * are not permitted. * The property contains "true" * if mechanisms susceptible to active attacks * are not permitted; "false" if such mechanisms are permitted. * The default is "false". *
The value of this constant is * "javax.security.sasl.policy.noactive". */ public static final String POLICY_NOACTIVE = "javax.security.sasl.policy.noactive"; /** * The name of a property that specifies whether * mechanisms susceptible to passive dictionary attacks are not permitted. * The property contains "true" * if mechanisms susceptible to dictionary attacks are not permitted; * "false" if such mechanisms are permitted. * The default is "false". *
* The value of this constant is * "javax.security.sasl.policy.nodictionary". */ public static final String POLICY_NODICTIONARY = "javax.security.sasl.policy.nodictionary"; /** * The name of a property that specifies whether mechanisms that accept * anonymous login are not permitted. The property contains "true" * if mechanisms that accept anonymous login are not permitted; * "false" * if such mechanisms are permitted. The default is "false". *
* The value of this constant is * "javax.security.sasl.policy.noanonymous". */ public static final String POLICY_NOANONYMOUS = "javax.security.sasl.policy.noanonymous"; /** * The name of a property that specifies whether mechanisms that implement * forward secrecy between sessions are required. Forward secrecy * means that breaking into one session will not automatically * provide information for breaking into future sessions. * The property * contains "true" if mechanisms that implement forward secrecy * between sessions are required; "false" if such mechanisms * are not required. The default is "false". *
* The value of this constant is * "javax.security.sasl.policy.forward". */ public static final String POLICY_FORWARD_SECRECY = "javax.security.sasl.policy.forward"; /** * The name of a property that specifies whether * mechanisms that pass client credentials are required. The property * contains "true" if mechanisms that pass * client credentials are required; "false" * if such mechanisms are not required. The default is "false". *
* The value of this constant is * "javax.security.sasl.policy.credentials". */ public static final String POLICY_PASS_CREDENTIALS = "javax.security.sasl.policy.credentials"; /** * The name of a property that specifies the credentials to use. * The property contains a mechanism-specific Java credential object. * Mechanism implementations may examine the value of this property * to determine whether it is a class that they support. * The property may be used to supply credentials to a mechanism that * supports delegated authentication. *
* The value of this constant is * "javax.security.sasl.credentials". */ public static final String CREDENTIALS = "javax.security.sasl.credentials"; /** * Creates a SaslClient using the parameters supplied. * * This method uses the JCA Security Provider Framework, described in the * "Java Cryptography Architecture API Specification & Reference", for * locating and selecting a SaslClient implementation. * * First, it * obtains an ordered list of SaslClientFactory instances from * the registered security providers for the "SaslClientFactory" service * and the specified SASL mechanism(s). It then invokes * createSaslClient() on each factory instance on the list * until one produces a non-null SaslClient instance. It returns * the non-null SaslClient instance, or null if the search fails * to produce a non-null SaslClient instance. *

* A security provider for SaslClientFactory registers with the * JCA Security Provider Framework keys of the form
* SaslClientFactory.mechanism_name *
* and values that are class names of implementations of * javax.security.sasl.SaslClientFactory. * * For example, a provider that contains a factory class, * com.wiz.sasl.digest.ClientFactory, that supports the * "DIGEST-MD5" mechanism would register the following entry with the JCA: * SaslClientFactory.DIGEST-MD5 com.wiz.sasl.digest.ClientFactory *

* See the * "Java Cryptography Architecture API Specification & Reference" * for information about how to install and configure security service * providers. * * @param mechanisms The non-null list of mechanism names to try. Each is the * IANA-registered name of a SASL mechanism. (e.g. "GSSAPI", "CRAM-MD5"). * @param authorizationId The possibly null protocol-dependent * identification to be used for authorization. * If null or empty, the server derives an authorization * ID from the client's authentication credentials. * When the SASL authentication completes successfully, * the specified entity is granted access. * * @param protocol The non-null string name of the protocol for which * the authentication is being performed (e.g., "ldap"). * * @param serverName The non-null fully-qualified host name of the server * to authenticate to. * * @param props The possibly null set of properties used to * select the SASL mechanism and to configure the authentication * exchange of the selected mechanism. * For example, if props contains the * Sasl.POLICY_NOPLAINTEXT property with the value * "true", then the selected * SASL mechanism must not be susceptible to simple plain passive attacks. * In addition to the standard properties declared in this class, * other, possibly mechanism-specific, properties can be included. * Properties not relevant to the selected mechanism are ignored, * including any map entries with non-String keys. * * @param cbh The possibly null callback handler to used by the SASL * mechanisms to get further information from the application/library * to complete the authentication. For example, a SASL mechanism might * require the authentication ID, password and realm from the caller. * The authentication ID is requested by using a NameCallback. * The password is requested by using a PasswordCallback. * The realm is requested by using a RealmChoiceCallback if there is a list * of realms to choose from, and by using a RealmCallback if * the realm must be entered. * *@return A possibly null SaslClient created using the parameters * supplied. If null, cannot find a SaslClientFactory * that will produce one. *@exception SaslException If cannot create a SaslClient because * of an error. */ public static SaslClient createSaslClient( String[] mechanisms, String authorizationId, String protocol, String serverName, Map props, CallbackHandler cbh) throws SaslException { SaslClient mech = null; SaslClientFactory fac; String className; String mechName; for (int i = 0; i < mechanisms.length; i++) { if ((mechName=mechanisms[i]) == null) { throw new NullPointerException( "Mechanism name cannot be null"); } else if (mechName.length() == 0) { continue; } String mechFilter = "SaslClientFactory." + mechName; Provider[] provs = Security.getProviders(mechFilter); for (int j = 0; provs != null && j < provs.length; j++) { className = provs[j].getProperty(mechFilter); if (className == null) { // Case is ignored continue; } fac = (SaslClientFactory) loadFactory(provs[j], className); if (fac != null) { mech = fac.createSaslClient( new String[]{mechanisms[i]}, authorizationId, protocol, serverName, props, cbh); if (mech != null) { return mech; } } } } return null; } private static Object loadFactory(Provider p, String className) throws SaslException { try { /* * Load the implementation class with the same class loader * that was used to load the provider. * In order to get the class loader of a class, the * caller's class loader must be the same as or an ancestor of * the class loader being returned. Otherwise, the caller must * have "getClassLoader" permission, or a SecurityException * will be thrown. */ ClassLoader cl = p.getClass().getClassLoader(); Class implClass; implClass = Class.forName(className, true, cl); return implClass.newInstance(); } catch (ClassNotFoundException e) { throw new SaslException("Cannot load class " + className, e); } catch (InstantiationException e) { throw new SaslException("Cannot instantiate class " + className, e); } catch (IllegalAccessException e) { throw new SaslException("Cannot access class " + className, e); } catch (SecurityException e) { throw new SaslException("Cannot access class " + className, e); } } /** * Creates a SaslServer for the specified mechanism. * * This method uses the JCA Security Provider Framework, * described in the * "Java Cryptography Architecture API Specification & Reference", for * locating and selecting a SaslServer implementation. * * First, it * obtains an ordered list of SaslServerFactory instances from * the registered security providers for the "SaslServerFactory" service * and the specified mechanism. It then invokes * createSaslServer() on each factory instance on the list * until one produces a non-null SaslServer instance. It returns * the non-null SaslServer instance, or null if the search fails * to produce a non-null SaslServer instance. *

* A security provider for SaslServerFactory registers with the * JCA Security Provider Framework keys of the form
* SaslServerFactory.mechanism_name *
* and values that are class names of implementations of * javax.security.sasl.SaslServerFactory. * * For example, a provider that contains a factory class, * com.wiz.sasl.digest.ServerFactory, that supports the * "DIGEST-MD5" mechanism would register the following entry with the JCA: * SaslServerFactory.DIGEST-MD5 com.wiz.sasl.digest.ServerFactory *

* See the * "Java Cryptography Architecture API Specification & Reference" * for information about how to install and configure security * service providers. * * @param mechanism The non-null mechanism name. It must be an * IANA-registered name of a SASL mechanism. (e.g. "GSSAPI", "CRAM-MD5"). * @param protocol The non-null string name of the protocol for which * the authentication is being performed (e.g., "ldap"). * @param serverName The non-null fully qualified host name of the server. * @param props The possibly null set of properties used to * select the SASL mechanism and to configure the authentication * exchange of the selected mechanism. * For example, if props contains the * Sasl.POLICY_NOPLAINTEXT property with the value * "true", then the selected * SASL mechanism must not be susceptible to simple plain passive attacks. * In addition to the standard properties declared in this class, * other, possibly mechanism-specific, properties can be included. * Properties not relevant to the selected mechanism are ignored, * including any map entries with non-String keys. * * @param cbh The possibly null callback handler to used by the SASL * mechanisms to get further information from the application/library * to complete the authentication. For example, a SASL mechanism might * require the authentication ID, password and realm from the caller. * The authentication ID is requested by using a NameCallback. * The password is requested by using a PasswordCallback. * The realm is requested by using a RealmChoiceCallback if there is a list * of realms to choose from, and by using a RealmCallback if * the realm must be entered. * *@return A possibly null SaslServer created using the parameters * supplied. If null, cannot find a SaslServerFactory * that will produce one. *@exception SaslException If cannot create a SaslServer because * of an error. **/ public static SaslServer createSaslServer(String mechanism, String protocol, String serverName, Map props, javax.security.auth.callback.CallbackHandler cbh) throws SaslException { SaslServer mech = null; SaslServerFactory fac; String className; if (mechanism == null) { throw new NullPointerException("Mechanism name cannot be null"); } else if (mechanism.length() == 0) { return null; } String mechFilter = "SaslServerFactory." + mechanism; Provider[] provs = Security.getProviders(mechFilter); for (int j = 0; provs != null && j < provs.length; j++) { className = provs[j].getProperty(mechFilter); if (className == null) { throw new SaslException("Provider does not support " + mechFilter); } fac = (SaslServerFactory) loadFactory(provs[j], className); if (fac != null) { mech = fac.createSaslServer( mechanism, protocol, serverName, props, cbh); if (mech != null) { return mech; } } } return null; } /** * Gets an enumeration of known factories for producing SaslClient. * This method uses the same algorithm for locating factories as * createSaslClient(). * @return A non-null enumeration of known factories for producing * SaslClient. * @see #createSaslClient */ public static Enumeration getSaslClientFactories() { Set facs = getFactories("SaslClientFactory"); final Iterator iter = facs.iterator(); return new Enumeration() { public boolean hasMoreElements() { return iter.hasNext(); } public SaslClientFactory nextElement() { return (SaslClientFactory)iter.next(); } }; } /** * Gets an enumeration of known factories for producing SaslServer. * This method uses the same algorithm for locating factories as * createSaslServer(). * @return A non-null enumeration of known factories for producing * SaslServer. * @see #createSaslServer */ public static Enumeration getSaslServerFactories() { Set facs = getFactories("SaslServerFactory"); final Iterator iter = facs.iterator(); return new Enumeration() { public boolean hasMoreElements() { return iter.hasNext(); } public SaslServerFactory nextElement() { return (SaslServerFactory)iter.next(); } }; } private static Set getFactories(String serviceName) { HashSet result = new HashSet(); if ((serviceName == null) || (serviceName.length() == 0) || (serviceName.endsWith("."))) { return result; } Provider[] providers = Security.getProviders(); HashSet classes = new HashSet(); Object fac; for (int i = 0; i < providers.length; i++) { classes.clear(); // Check the keys for each provider. for (Enumeration e = providers[i].keys(); e.hasMoreElements(); ) { String currentKey = (String)e.nextElement(); if (currentKey.startsWith(serviceName)) { // We should skip the currentKey if it contains a // whitespace. The reason is: such an entry in the // provider property contains attributes for the // implementation of an algorithm. We are only interested // in entries which lead to the implementation // classes. if (currentKey.indexOf(" ") < 0) { String className = providers[i].getProperty(currentKey); if (!classes.contains(className)) { classes.add(className); try { fac = loadFactory(providers[i], className); if (fac != null) { result.add(fac); } }catch (Exception ignore) { } } } } } } return Collections.unmodifiableSet(result); } }