/*

 * Copyright (c) 1996, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.security.ssl;

import java.io.OutputStream;

import java.io.IOException;

/**

 * Output stream for handshake data.  This is used only internally

 * to the SSL classes.

 *

 * MT note:  one thread at a time is presumed be writing handshake

 * messages, but (after initial connection setup) it's possible to

 * have other threads reading/writing application data.  It's the

 * SSLSocketImpl class that synchronizes record writes.

 *

 * @author  David Brownell

 */

public class HandshakeOutStream extends OutputStream {

    private SSLSocketImpl socket;

    private SSLEngineImpl engine;

    OutputRecord r;

    HandshakeOutStream(ProtocolVersion protocolVersion,

            ProtocolVersion helloVersion, HandshakeHash handshakeHash,

            SSLSocketImpl socket) {

        this.socket = socket;

        r = new OutputRecord(Record.ct_handshake);

        init(protocolVersion, helloVersion, handshakeHash);

    }

    HandshakeOutStream(ProtocolVersion protocolVersion,

            ProtocolVersion helloVersion, HandshakeHash handshakeHash,

            SSLEngineImpl engine) {

        this.engine = engine;

        r = new EngineOutputRecord(Record.ct_handshake, engine);

        init(protocolVersion, helloVersion, handshakeHash);

    }

    private void init(ProtocolVersion protocolVersion,

            ProtocolVersion helloVersion, HandshakeHash handshakeHash) {

        r.setVersion(protocolVersion);

        r.setHelloVersion(helloVersion);

        r.setHandshakeHash(handshakeHash);

    }

    /*

     * Update the handshake data hashes ... mostly for use after a

     * client cert has been sent, so the cert verify message can be

     * constructed correctly yet without forcing extra I/O.  In all

     * other cases, automatic hash calculation suffices.

     */

    void doHashes() {

        r.doHashes();

    }

    /*

     * Write some data out onto the stream ... buffers as much as possible.

     * Hashes are updated automatically if something gets flushed to the

     * network (e.g. a big cert message etc).

     */

    @Override

    public void write(byte buf[], int off, int len) throws IOException {

        while (len > 0) {

            int howmuch = Math.min(len, r.availableDataBytes());

            if (howmuch == 0) {

                flush();

            } else {

                r.write(buf, off, howmuch);

                off += howmuch;

                len -= howmuch;

            }

        }

    }

    /*

     * write-a-byte

     */

    @Override

    public void write(int i) throws IOException {

        if (r.availableDataBytes() < 1) {

            flush();

        }

        r.write(i);

    }

    @Override

    public void flush() throws IOException {

        if (socket != null) {

            try {

                socket.writeRecord(r);

            } catch (IOException e) {

                // Had problems writing; check if there was an

                // alert from peer. If alert received, waitForClose

                // will throw an exception for the alert

                socket.waitForClose(true);

                // No alert was received, just rethrow exception

                throw e;

            }

        } else {  // engine != null

            /*

             * Even if record might be empty, flush anyway in case

             * there is a finished handshake message that we need

             * to queue.

             */

            engine.writeRecord((EngineOutputRecord)r);

        }

    }

    /*

     * Tell the OutputRecord that a finished message was

     * contained either in this record or the one immeiately

     * preceding it.  We need to reliably pass back notifications

     * that a finish message occurred.

     */

    void setFinishedMsg() {

        assert(socket == null);

        ((EngineOutputRecord)r).setFinishedMsg();

    }

    /*

     * Put integers encoded in standard 8, 16, 24, and 32 bit

     * big endian formats. Note that OutputStream.write(int) only

     * writes the least significant 8 bits and ignores the rest.

     */

    void putInt8(int i) throws IOException {

        checkOverflow(i, Record.OVERFLOW_OF_INT08);

        r.write(i);

    }

    void putInt16(int i) throws IOException {

        checkOverflow(i, Record.OVERFLOW_OF_INT16);

        if (r.availableDataBytes() < 2) {

            flush();

        }

        r.write(i >> 8);

        r.write(i);

    }

    void putInt24(int i) throws IOException {

        checkOverflow(i, Record.OVERFLOW_OF_INT24);

        if (r.availableDataBytes() < 3) {

            flush();

        }

        r.write(i >> 16);

        r.write(i >> 8);

        r.write(i);

    }

    void putInt32(int i) throws IOException {

        if (r.availableDataBytes() < 4) {

            flush();

        }

        r.write(i >> 24);

        r.write(i >> 16);

        r.write(i >> 8);

        r.write(i);

    }

    /*

     * Put byte arrays with length encoded as 8, 16, 24 bit

     * integers in big-endian format.

     */

    void putBytes8(byte b[]) throws IOException {

        if (b == null) {

            putInt8(0);

            return;

        } else {

            checkOverflow(b.length, Record.OVERFLOW_OF_INT08);

        }

        putInt8(b.length);

        write(b, 0, b.length);

    }

    public void putBytes16(byte b[]) throws IOException {

        if (b == null) {

            putInt16(0);

            return;

        } else {

            checkOverflow(b.length, Record.OVERFLOW_OF_INT16);

        }

        putInt16(b.length);

        write(b, 0, b.length);

    }

    void putBytes24(byte b[]) throws IOException {

        if (b == null) {

            putInt24(0);

            return;

        } else {

            checkOverflow(b.length, Record.OVERFLOW_OF_INT24);

        }

        putInt24(b.length);

        write(b, 0, b.length);

    }

    private void checkOverflow(int length, int overflow) {

        if (length >= overflow) {

            // internal_error alert will be triggered

            throw new RuntimeException(

                    "Field length overflow, the field length (" +

                    length + ") should be less than " + overflow);

        }

    }

}