/* * Copyright (c) 2000, 2004, 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; /** * Performs SASL authentication as a server. *<p> * A server such an LDAP server gets an instance of this * class in order to perform authentication defined by a specific SASL * mechanism. Invoking methods on the <tt>SaslServer</tt> instance * generates challenges according to the SASL * mechanism implemented by the <tt>SaslServer</tt>. * As the authentication proceeds, the instance * encapsulates the state of a SASL server's authentication exchange. *<p> * Here's an example of how an LDAP server might use a <tt>SaslServer</tt>. * It first gets an instance of a <tt>SaslServer</tt> for the SASL mechanism * requested by the client: *<blockquote><pre> * SaslServer ss = Sasl.createSaslServer(mechanism, *     "ldap", myFQDN, props, callbackHandler); *</pre></blockquote> * It can then proceed to use the server for authentication. * For example, suppose the LDAP server received an LDAP BIND request * containing the name of the SASL mechanism and an (optional) initial * response. It then might use the server as follows: *<blockquote><pre> * while (!ss.isComplete()) { *     try { *         byte[] challenge = ss.evaluateResponse(response); *         if (ss.isComplete()) { *             status = ldap.sendBindResponse(mechanism, challenge, SUCCESS); *         } else { *             status = ldap.sendBindResponse(mechanism, challenge,                   SASL_BIND_IN_PROGRESS); *             response = ldap.readBindRequest(); *         } *     } catch (SaslException e) { *          status = ldap.sendErrorResponse(e); *          break; *     } * } * if (ss.isComplete() && status == SUCCESS) { *    String qop = (String) sc.getNegotiatedProperty(Sasl.QOP); *    if (qop != null *        && (qop.equalsIgnoreCase("auth-int") *            || qop.equalsIgnoreCase("auth-conf"))) { * *      // Use SaslServer.wrap() and SaslServer.unwrap() for future *      // communication with client *      ldap.in = new SecureInputStream(ss, ldap.in); *      ldap.out = new SecureOutputStream(ss, ldap.out); *    } * } *</pre></blockquote> * * @since 1.5 * * @see Sasl * @see SaslServerFactory * * @author Rosanna Lee * @author Rob Weltman */public abstract interface SaslServer {     /**     * Returns the IANA-registered mechanism name of this SASL server.     * (e.g. "CRAM-MD5", "GSSAPI").     * @return A non-null string representing the IANA-registered mechanism name.     */    public abstract String getMechanismName();     /**     * Evaluates the response data and generates a challenge.     *     * If a response is received from the client during the authentication     * process, this method is called to prepare an appropriate next     * challenge to submit to the client. The challenge is null if the     * authentication has succeeded and no more challenge data is to be sent     * to the client. It is non-null if the authentication must be continued     * by sending a challenge to the client, or if the authentication has     * succeeded but challenge data needs to be processed by the client.     * <tt>isComplete()</tt> should be called     * after each call to <tt>evaluateResponse()</tt>,to determine if any further     * response is needed from the client.     *     * @param response The non-null (but possibly empty) response sent     * by the client.     *     * @return The possibly null challenge to send to the client.     * It is null if the authentication has succeeded and there is     * no more challenge data to be sent to the client.     * @exception SaslException If an error occurred while processing     * the response or generating a challenge.     */    public abstract byte[] evaluateResponse(byte[] response)        throws SaslException;     /**      * Determines whether the authentication exchange has completed.      * This method is typically called after each invocation of      * <tt>evaluateResponse()</tt> to determine whether the      * authentication has completed successfully or should be continued.      * @return true if the authentication exchange has completed; false otherwise.      */    public abstract boolean isComplete();     /**     * Reports the authorization ID in effect for the client of this     * session.     * This method can only be called if isComplete() returns true.     * @return The authorization ID of the client.     * @exception IllegalStateException if this authentication session has not completed     */    public String getAuthorizationID();     /**     * Unwraps a byte array received from the client.     * This method can be called only after the authentication exchange has     * completed (i.e., when <tt>isComplete()</tt> returns true) and only if     * the authentication exchange has negotiated integrity and/or privacy     * as the quality of protection; otherwise,     * an <tt>IllegalStateException</tt> is thrown.     *<p>     * <tt>incoming</tt> is the contents of the SASL buffer as defined in RFC 2222     * without the leading four octet field that represents the length.     * <tt>offset</tt> and <tt>len</tt> specify the portion of <tt>incoming</tt>     * to use.     *     * @param incoming A non-null byte array containing the encoded bytes     *                from the client.     * @param offset The starting position at <tt>incoming</tt> of the bytes to use.     * @param len The number of bytes from <tt>incoming</tt> to use.     * @return A non-null byte array containing the decoded bytes.     * @exception SaslException if <tt>incoming</tt> cannot be successfully     * unwrapped.     * @exception IllegalStateException if the authentication exchange has     * not completed, or if the negotiated quality of protection     * has neither integrity nor privacy     */    public abstract byte[] unwrap(byte[] incoming, int offset, int len)        throws SaslException;     /**     * Wraps a byte array to be sent to the client.     * This method can be called only after the authentication exchange has     * completed (i.e., when <tt>isComplete()</tt> returns true) and only if     * the authentication exchange has negotiated integrity and/or privacy     * as the quality of protection; otherwise, a <tt>SaslException</tt> is thrown.     *<p>     * The result of this method     * will make up the contents of the SASL buffer as defined in RFC 2222     * without the leading four octet field that represents the length.     * <tt>offset</tt> and <tt>len</tt> specify the portion of <tt>outgoing</tt>     * to use.     *     * @param outgoing A non-null byte array containing the bytes to encode.     * @param offset The starting position at <tt>outgoing</tt> of the bytes to use.     * @param len The number of bytes from <tt>outgoing</tt> to use.     * @return A non-null byte array containing the encoded bytes.     * @exception SaslException if <tt>outgoing</tt> cannot be successfully     * wrapped.     * @exception IllegalStateException if the authentication exchange has     * not completed, or if the negotiated quality of protection has     * neither integrity nor privacy.     */    public abstract byte[] wrap(byte[] outgoing, int offset, int len)        throws SaslException;     /**     * Retrieves the negotiated property.     * This method can be called only after the authentication exchange has     * completed (i.e., when <tt>isComplete()</tt> returns true); otherwise, an     * <tt>IllegalStateException</tt> is thrown.     *     * @param propName the property     * @return The value of the negotiated property. If null, the property was     * not negotiated or is not applicable to this mechanism.     * @exception IllegalStateException if this authentication exchange has not completed     */     public abstract Object getNegotiatedProperty(String propName);      /**      * Disposes of any system resources or security-sensitive information      * the SaslServer might be using. Invoking this method invalidates      * the SaslServer instance. This method is idempotent.      * @throws SaslException If a problem was encountered while disposing      * the resources.      */    public abstract void dispose() throws SaslException;}