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 * 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

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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);

        }

    }

}