/*

 * Copyright (c) 2003, 2013, 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.gsskerb;

import java.util.Map;

import java.util.logging.Level;

import javax.security.sasl.*;

import com.sun.security.sasl.util.AbstractSaslImpl;

import org.ietf.jgss.*;

abstract class GssKrb5Base extends AbstractSaslImpl {

    private static final String KRB5_OID_STR = "1.2.840.113554.1.2.2";

    protected static Oid KRB5_OID;

    protected static final byte[] EMPTY = new byte[0];

    static {

        try {

            KRB5_OID = new Oid(KRB5_OID_STR);

        } catch (GSSException ignore) {}

    }

    protected GSSContext secCtx = null;

    protected static final int JGSS_QOP = 0;    // unrelated to SASL QOP mask

    protected GssKrb5Base(Map<String, ?> props, String className)

        throws SaslException {

        super(props, className);

    }

    /**

     * Retrieves this mechanism's name.

     *

     * @return  The string "GSSAPI".

     */

    public String getMechanismName() {

        return "GSSAPI";

    }

    public byte[] unwrap(byte[] incoming, int start, int len)

        throws SaslException {

        if (!completed) {

            throw new IllegalStateException("GSSAPI authentication not completed");

        }

        // integrity will be true if either privacy or integrity negotiated

        if (!integrity) {

            throw new IllegalStateException("No security layer negotiated");

        }

        try {

            MessageProp msgProp = new MessageProp(JGSS_QOP, privacy);

            byte[] answer = secCtx.unwrap(incoming, start, len, msgProp);

            if (logger.isLoggable(Level.FINEST)) {

                traceOutput(myClassName, "KRB501:Unwrap", "incoming: ",

                    incoming, start, len);

                traceOutput(myClassName, "KRB502:Unwrap", "unwrapped: ",

                    answer, 0, answer.length);

            }

            return answer;

        } catch (GSSException e) {

            throw new SaslException("Problems unwrapping SASL buffer", e);

        }

    }

    public byte[] wrap(byte[] outgoing, int start, int len) throws SaslException {

        if (!completed) {

            throw new IllegalStateException("GSSAPI authentication not completed");

        }

        // integrity will be true if either privacy or integrity negotiated

        if (!integrity) {

            throw new IllegalStateException("No security layer negotiated");

        }

        // Generate GSS token

        try {

            MessageProp msgProp = new MessageProp(JGSS_QOP, privacy);

            byte[] answer = secCtx.wrap(outgoing, start, len, msgProp);

            if (logger.isLoggable(Level.FINEST)) {

                traceOutput(myClassName, "KRB503:Wrap", "outgoing: ",

                    outgoing, start, len);

                traceOutput(myClassName, "KRB504:Wrap", "wrapped: ",

                    answer, 0, answer.length);

            }

            return answer;

        } catch (GSSException e) {

            throw new SaslException("Problem performing GSS wrap", e);

        }

    }

    public void dispose() throws SaslException {

        if (secCtx != null) {

            try {

                secCtx.dispose();

            } catch (GSSException e) {

                throw new SaslException("Problem disposing GSS context", e);

            }

            secCtx = null;

        }

    }

    protected void finalize() throws Throwable {

        dispose();

    }

}