Java example source code file (ClientFactoryImpl.java)

This example Java source code file (ClientFactoryImpl.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

callbackhandler, cannot, clientfactoryimpl, cram\-md5, crammd5, external, ioexception, namecallback, object, passwordcallback, plain, saslclient, saslexception, string, util

The ClientFactoryImpl.java Java example source code

/*
 * 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 com.sun.security.sasl;

import javax.security.sasl.*;
import com.sun.security.sasl.util.PolicyUtils;

import java.util.Map;
import java.io.IOException;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.UnsupportedCallbackException;

/**
  * Client factory for EXTERNAL, CRAM-MD5, PLAIN.
  *
  * Requires the following callbacks to be satisfied by callback handler
  * when using CRAM-MD5 or PLAIN.
  * - NameCallback (to get username)
  * - PasswordCallback (to get password)
  *
  * @author Rosanna Lee
  */
final public class ClientFactoryImpl implements SaslClientFactory {
    private static final String myMechs[] = {
        "EXTERNAL",
        "CRAM-MD5",
        "PLAIN",
    };

    private static final int mechPolicies[] = {
        // %%% RL: Policies should actually depend on the external channel
        PolicyUtils.NOPLAINTEXT|PolicyUtils.NOACTIVE|PolicyUtils.NODICTIONARY,
        PolicyUtils.NOPLAINTEXT|PolicyUtils.NOANONYMOUS,    // CRAM-MD5
        PolicyUtils.NOANONYMOUS,                            // PLAIN
    };

    private static final int EXTERNAL = 0;
    private static final int CRAMMD5 = 1;
    private static final int PLAIN = 2;

    public ClientFactoryImpl() {
    }

    public SaslClient createSaslClient(String[] mechs,
        String authorizationId,
        String protocol,
        String serverName,
        Map<String,?> props,
        CallbackHandler cbh) throws SaslException {

            for (int i = 0; i < mechs.length; i++) {
                if (mechs[i].equals(myMechs[EXTERNAL])
                    && PolicyUtils.checkPolicy(mechPolicies[EXTERNAL], props)) {
                    return new ExternalClient(authorizationId);

                } else if (mechs[i].equals(myMechs[CRAMMD5])
                    && PolicyUtils.checkPolicy(mechPolicies[CRAMMD5], props)) {

                    Object[] uinfo = getUserInfo("CRAM-MD5", authorizationId, cbh);

                    // Callee responsible for clearing bytepw
                    return new CramMD5Client((String) uinfo[0],
                        (byte []) uinfo[1]);

                } else if (mechs[i].equals(myMechs[PLAIN])
                    && PolicyUtils.checkPolicy(mechPolicies[PLAIN], props)) {

                    Object[] uinfo = getUserInfo("PLAIN", authorizationId, cbh);

                    // Callee responsible for clearing bytepw
                    return new PlainClient(authorizationId,
                        (String) uinfo[0], (byte []) uinfo[1]);
                }
            }
            return null;
    };

    public String[] getMechanismNames(Map<String,?> props) {
        return PolicyUtils.filterMechs(myMechs, mechPolicies, props);
    }

    /**
     * Gets the authentication id and password. The
     * password is converted to bytes using UTF-8 and stored in bytepw.
     * The authentication id is stored in authId.
     *
     * @param prefix The non-null prefix to use for the prompt (e.g., mechanism
     *  name)
     * @param authorizationId The possibly null authorization id. This is used
     * as a default for the NameCallback. If null, it is not used in prompt.
     * @param cbh The non-null callback handler to use.
     * @return an {authid, passwd} pair
     */
    private Object[] getUserInfo(String prefix, String authorizationId,
        CallbackHandler cbh) throws SaslException {
        if (cbh == null) {
            throw new SaslException(
                "Callback handler to get username/password required");
        }
        try {
            String userPrompt = prefix + " authentication id: ";
            String passwdPrompt = prefix + " password: ";

            NameCallback ncb = authorizationId == null?
                new NameCallback(userPrompt) :
                new NameCallback(userPrompt, authorizationId);

            PasswordCallback pcb = new PasswordCallback(passwdPrompt, false);

            cbh.handle(new Callback[]{ncb,pcb});

            char[] pw = pcb.getPassword();

            byte[] bytepw;
            String authId;

            if (pw != null) {
                bytepw = new String(pw).getBytes("UTF8");
                pcb.clearPassword();
            } else {
                bytepw = null;
            }

            authId = ncb.getName();

            return new Object[]{authId, bytepw};

        } catch (IOException e) {
            throw new SaslException("Cannot get password", e);
        } catch (UnsupportedCallbackException e) {
            throw new SaslException("Cannot get userid/password", e);
        }
    }
}