jdk/src/share/classes/javax/security/sasl/Sasl.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/security/sasl/Sasl.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,606 @@
+/*
+ * Copyright 1999-2006 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.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.
+ *<p>
+ * This class defines the policy of how to locate, load, and instantiate
+ * SASL clients and servers.
+ *<p>
+ * For example, an application or library gets a SASL client by doing
+ * something like:
+ *<blockquote><pre>
+ * SaslClient sc = Sasl.createSaslClient(mechanisms,
+ *     authorizationId, protocol, serverName, props, callbackHandler);
+ *</pre></blockquote>
+ * It can then proceed to use the instance to create an authentication connection.
+ *<p>
+ * Similarly, a server gets a SASL server by using code that looks as follows:
+ *<blockquote><pre>
+ * SaslServer ss = Sasl.createSaslServer(mechanism,
+ *     protocol, serverName, props, callbackHandler);
+ *</pre></blockquote>
+ *
+ * @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
+     * <ul>
+     * <li><tt>"auth"</tt> - authentication only</li>
+     * <li><tt>"auth-int"</tt> - authentication plus integrity protection</li>
+     * <li><tt>"auth-conf"</tt> - authentication plus integrity and confidentiality
+     * protection</li>
+     * </ul>
+     *
+     * The order of the list specifies the preference order of the client or
+     * server. If this property is absent, the default qop is <tt>"auth"</tt>.
+     * The value of this constant is <tt>"javax.security.sasl.qop"</tt>.
+     */
+    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
+     * <ul>
+     * <li><tt>"low"</tt></li>
+     * <li><tt>"medium"</tt></li>
+     * <li><tt>"high"</tt></li>
+     * </ul>
+     * 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.
+     * <BR>
+     * If this property is absent, the default strength is
+     * <tt>"high,medium,low"</tt>.
+     * The value of this constant is <tt>"javax.security.sasl.strength"</tt>.
+     */
+    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
+     * <tt>"true"</tt> if the server must
+     * authenticate the to client; <tt>"false"</tt> otherwise.
+     * The default is <tt>"false"</tt>.
+     * <br>The value of this constant is
+     * <tt>"javax.security.sasl.server.authentication"</tt>.
+     */
+    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 <tt>SaslClient</tt>/<tt>SaslServer</tt>.
+     * The property contains the string representation of an integer.
+     * <br>If this property is absent, the default size
+     * is defined by the mechanism.
+     * <br>The value of this constant is <tt>"javax.security.sasl.maxbuffer"</tt>.
+     */
+    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 <tt>SaslClient</tt>/<tt>SaslServer</tt>.
+     * 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.
+     * <br>The value of this constant is <tt>"javax.security.sasl.rawsendsize"</tt>.
+     */
+    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 <tt>"true"</tt> if such mechanisms are not permitted;
+     * <tt>"false"</tt> if such mechanisms are permitted.
+     * The default is <tt>"false"</tt>.
+     * <br>The value of this constant is
+     * <tt>"javax.security.sasl.policy.noplaintext"</tt>.
+     */
+    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 <tt>"true"</tt>
+     * if mechanisms susceptible to active attacks
+     * are not permitted; <tt>"false"</tt> if such mechanisms are permitted.
+     * The default is <tt>"false"</tt>.
+     * <br>The value of this constant is
+     * <tt>"javax.security.sasl.policy.noactive"</tt>.
+     */
+    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 <tt>"true"</tt>
+     * if mechanisms susceptible to dictionary attacks are not permitted;
+     * <tt>"false"</tt> if such mechanisms are permitted.
+     * The default is <tt>"false"</tt>.
+     *<br>
+     * The value of this constant is
+     * <tt>"javax.security.sasl.policy.nodictionary"</tt>.
+     */
+    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 <tt>"true"</tt>
+     * if mechanisms that accept anonymous login are not permitted;
+     * <tt>"false"</tt>
+     * if such mechanisms are permitted. The default is <tt>"false"</tt>.
+     *<br>
+     * The value of this constant is
+     * <tt>"javax.security.sasl.policy.noanonymous"</tt>.
+     */
+    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 <tt>"true"</tt> if mechanisms that implement forward secrecy
+      * between sessions are required; <tt>"false"</tt> if such mechanisms
+      * are not required. The default is <tt>"false"</tt>.
+      *<br>
+      * The value of this constant is
+      * <tt>"javax.security.sasl.policy.forward"</tt>.
+      */
+    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 <tt>"true"</tt> if mechanisms that pass
+     * client credentials are required; <tt>"false"</tt>
+     * if such mechanisms are not required. The default is <tt>"false"</tt>.
+     *<br>
+     * The value of this constant is
+     * <tt>"javax.security.sasl.policy.credentials"</tt>.
+     */
+    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.
+     *<br>
+     * The value of this constant is
+     * <tt>"javax.security.sasl.credentials"</tt>.
+     */
+    public static final String CREDENTIALS = "javax.security.sasl.credentials";
+
+    /**
+     * Creates a <tt>SaslClient</tt> using the parameters supplied.
+     *
+     * This method uses the
+<a href="{@docRoot}/../technotes/guides/security/crypto/CryptoSpec.html#Provider">JCA Security Provider Framework</a>, described in the
+     * "Java Cryptography Architecture API Specification & Reference", for
+     * locating and selecting a <tt>SaslClient</tt> implementation.
+     *
+     * First, it
+     * obtains an ordered list of <tt>SaslClientFactory</tt> instances from
+     * the registered security providers for the "SaslClientFactory" service
+     * and the specified SASL mechanism(s). It then invokes
+     * <tt>createSaslClient()</tt> on each factory instance on the list
+     * until one produces a non-null <tt>SaslClient</tt> instance. It returns
+     * the non-null <tt>SaslClient</tt> instance, or null if the search fails
+     * to produce a non-null <tt>SaslClient</tt> instance.
+     *<p>
+     * A security provider for SaslClientFactory registers with the
+     * JCA Security Provider Framework keys of the form <br>
+     * <tt>SaslClientFactory.<em>mechanism_name</em></tt>
+     * <br>
+     * and values that are class names of implementations of
+     * <tt>javax.security.sasl.SaslClientFactory</tt>.
+     *
+     * For example, a provider that contains a factory class,
+     * <tt>com.wiz.sasl.digest.ClientFactory</tt>, that supports the
+     * "DIGEST-MD5" mechanism would register the following entry with the JCA:
+     * <tt>SaslClientFactory.DIGEST-MD5 com.wiz.sasl.digest.ClientFactory</tt>
+     *<p>
+     * 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 <tt>props</tt> contains the
+     * <code>Sasl.POLICY_NOPLAINTEXT</code> property with the value
+     * <tt>"true"</tt>, 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 <tt>NameCallback</tt>.
+     * The password is requested by using a <tt>PasswordCallback</tt>.
+     * The realm is requested by using a <tt>RealmChoiceCallback</tt> if there is a list
+     * of realms to choose from, and by using a <tt>RealmCallback</tt> if
+     * the realm must be entered.
+     *
+     *@return A possibly null <tt>SaslClient</tt> created using the parameters
+     * supplied. If null, cannot find a <tt>SaslClientFactory</tt>
+     * that will produce one.
+     *@exception SaslException If cannot create a <tt>SaslClient</tt> because
+     * of an error.
+     */
+    public static SaslClient createSaslClient(
+        String[] mechanisms,
+        String authorizationId,
+        String protocol,
+        String serverName,
+        Map<String,?> 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 <tt>SaslServer</tt> for the specified mechanism.
+     *
+     * This method uses the
+<a href="{@docRoot}/../technotes/guides/security/crypto/CryptoSpec.html#Provider">JCA Security Provider Framework</a>,
+     * described in the
+     * "Java Cryptography Architecture API Specification & Reference", for
+     * locating and selecting a <tt>SaslServer</tt> implementation.
+     *
+     * First, it
+     * obtains an ordered list of <tt>SaslServerFactory</tt> instances from
+     * the registered security providers for the "SaslServerFactory" service
+     * and the specified mechanism. It then invokes
+     * <tt>createSaslServer()</tt> on each factory instance on the list
+     * until one produces a non-null <tt>SaslServer</tt> instance. It returns
+     * the non-null <tt>SaslServer</tt> instance, or null if the search fails
+     * to produce a non-null <tt>SaslServer</tt> instance.
+     *<p>
+     * A security provider for SaslServerFactory registers with the
+     * JCA Security Provider Framework keys of the form <br>
+     * <tt>SaslServerFactory.<em>mechanism_name</em></tt>
+     * <br>
+     * and values that are class names of implementations of
+     * <tt>javax.security.sasl.SaslServerFactory</tt>.
+     *
+     * For example, a provider that contains a factory class,
+     * <tt>com.wiz.sasl.digest.ServerFactory</tt>, that supports the
+     * "DIGEST-MD5" mechanism would register the following entry with the JCA:
+     * <tt>SaslServerFactory.DIGEST-MD5  com.wiz.sasl.digest.ServerFactory</tt>
+     *<p>
+     * 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 <tt>props</tt> contains the
+     * <code>Sasl.POLICY_NOPLAINTEXT</code> property with the value
+     * <tt>"true"</tt>, 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 <tt>NameCallback</tt>.
+     * The password is requested by using a <tt>PasswordCallback</tt>.
+     * The realm is requested by using a <tt>RealmChoiceCallback</tt> if there is a list
+     * of realms to choose from, and by using a <tt>RealmCallback</tt> if
+     * the realm must be entered.
+     *
+     *@return A possibly null <tt>SaslServer</tt> created using the parameters
+     * supplied. If null, cannot find a <tt>SaslServerFactory</tt>
+     * that will produce one.
+     *@exception SaslException If cannot create a <tt>SaslServer</tt> because
+     * of an error.
+     **/
+    public static SaslServer
+        createSaslServer(String mechanism,
+                    String protocol,
+                    String serverName,
+                    Map<String,?> 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 <tt>SaslClient</tt>.
+     * This method uses the same algorithm for locating factories as
+     * <tt>createSaslClient()</tt>.
+     * @return A non-null enumeration of known factories for producing
+     * <tt>SaslClient</tt>.
+     * @see #createSaslClient
+     */
+    public static Enumeration<SaslClientFactory> getSaslClientFactories() {
+        Set<Object> facs = getFactories("SaslClientFactory");
+        final Iterator<Object> iter = facs.iterator();
+        return new Enumeration<SaslClientFactory>() {
+            public boolean hasMoreElements() {
+                return iter.hasNext();
+            }
+            public SaslClientFactory nextElement() {
+                return (SaslClientFactory)iter.next();
+            }
+        };
+    }
+
+    /**
+     * Gets an enumeration of known factories for producing <tt>SaslServer</tt>.
+     * This method uses the same algorithm for locating factories as
+     * <tt>createSaslServer()</tt>.
+     * @return A non-null enumeration of known factories for producing
+     * <tt>SaslServer</tt>.
+     * @see #createSaslServer
+     */
+    public static Enumeration<SaslServerFactory> getSaslServerFactories() {
+        Set<Object> facs = getFactories("SaslServerFactory");
+        final Iterator<Object> iter = facs.iterator();
+        return new Enumeration<SaslServerFactory>() {
+            public boolean hasMoreElements() {
+                return iter.hasNext();
+            }
+            public SaslServerFactory nextElement() {
+                return (SaslServerFactory)iter.next();
+            }
+        };
+    }
+
+    private static Set<Object> getFactories(String serviceName) {
+        HashSet<Object> result = new HashSet<Object>();
+
+        if ((serviceName == null) || (serviceName.length() == 0) ||
+            (serviceName.endsWith("."))) {
+            return result;
+        }
+
+
+        Provider[] providers = Security.getProviders();
+        HashSet<String> classes = new HashSet<String>();
+        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);
+    }
+}