/*

 * Copyright (c) 2004, 2010, 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 sun.security.jgss.krb5;

import org.ietf.jgss.*;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.IOException;

import java.io.ByteArrayOutputStream;

/**

 * This class represents the new format of GSS MIC tokens, as specified

 * in RFC 4121

 *

 * MIC tokens = { 16-byte token-header |  HMAC }

 * where HMAC is on { plaintext | 16-byte token-header }

 *

 * @author Seema Malkani

 */

class MicToken_v2 extends MessageToken_v2 {

    public MicToken_v2(Krb5Context context,

                  byte[] tokenBytes, int tokenOffset, int tokenLen,

                  MessageProp prop)  throws GSSException {

        super(Krb5Token.MIC_ID_v2, context,

                tokenBytes, tokenOffset, tokenLen, prop);

    }

    public MicToken_v2(Krb5Context context, InputStream is, MessageProp prop)

            throws GSSException {

        super(Krb5Token.MIC_ID_v2, context, is, prop);

    }

    public void verify(byte[] data, int offset, int len) throws GSSException {

        if (!verifySign(data, offset, len))

            throw new GSSException(GSSException.BAD_MIC, -1,

                         "Corrupt checksum or sequence number in MIC token");

    }

    public void verify(InputStream data) throws GSSException {

        byte[] dataBytes = null;

        try {

            dataBytes = new byte[data.available()];

            data.read(dataBytes);

        } catch (IOException e) {

            // Error reading application data

            throw new GSSException(GSSException.BAD_MIC, -1,

                "Corrupt checksum or sequence number in MIC token");

        }

        verify(dataBytes, 0, dataBytes.length);

    }

    public MicToken_v2(Krb5Context context, MessageProp prop,

                  byte[] data, int pos, int len)

            throws GSSException {

        super(Krb5Token.MIC_ID_v2, context);

        //      debug("Application data to MicToken verify is [" +

        //            getHexBytes(data, pos, len) + "]\n");

        if (prop == null) prop = new MessageProp(0, false);

        genSignAndSeqNumber(prop, data, pos, len);

    }

    public MicToken_v2(Krb5Context context, MessageProp prop, InputStream data)

            throws GSSException, IOException {

        super(Krb5Token.MIC_ID_v2, context);

        byte[] dataBytes = new byte[data.available()];

        data.read(dataBytes);

        // debug("Application data to MicToken cons is [" +

        //     getHexBytes(dataBytes) + "]\n");

        if (prop == null) prop = new MessageProp(0, false);

        genSignAndSeqNumber(prop, dataBytes, 0, dataBytes.length);

    }

    public byte[] encode() throws IOException {

        // XXX Fine tune this initial size

        ByteArrayOutputStream bos = new ByteArrayOutputStream(50);

        encode(bos);

        return bos.toByteArray();

    }

    public int encode(byte[] outToken, int offset) throws IOException {

        byte[] token = encode();

        System.arraycopy(token, 0, outToken, offset, token.length);

        return token.length;

    }

    public void encode(OutputStream os) throws IOException {

        encodeHeader(os);

        os.write(checksum);

    }

}