/*

 * 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 application data. This is the kind of stream

 * that's handed out via SSLSocket.getOutputStream(). It's all the application

 * ever sees.

 *

 * Once the initial handshake has completed, application data may be

 * interleaved with handshake data. That is handled internally and remains

 * transparent to the application.

 *

 * @author  David Brownell

 */

class AppOutputStream extends OutputStream {

    private SSLSocketImpl c;

    OutputRecord r;

    // One element array used to implement the write(byte) method

    private final byte[] oneByte = new byte[1];

    AppOutputStream(SSLSocketImpl conn) {

        r = new OutputRecord(Record.ct_application_data);

        c = conn;

    }

    /**

     * Write the data out, NOW.

     */

    synchronized public void write(byte b[], int off, int len)

            throws IOException {

        if (b == null) {

            throw new NullPointerException();

        } else if (off < 0 || len < 0 || len > b.length - off) {

            throw new IndexOutOfBoundsException();

        } else if (len == 0) {

            return;

        }

        // check if the Socket is invalid (error or closed)

        c.checkWrite();

        /*

         * By default, we counter chosen plaintext issues on CBC mode

         * ciphersuites in SSLv3/TLS1.0 by sending one byte of application

         * data in the first record of every payload, and the rest in

         * subsequent record(s). Note that the issues have been solved in

         * TLS 1.1 or later.

         *

         * It is not necessary to split the very first application record of

         * a freshly negotiated TLS session, as there is no previous

         * application data to guess.  To improve compatibility, we will not

         * split such records.

         *

         * This avoids issues in the outbound direction.  For a full fix,

         * the peer must have similar protections.

         */

        boolean isFirstRecordOfThePayload = true;

        // Always flush at the end of each application level record.

        // This lets application synchronize read and write streams

        // however they like; if we buffered here, they couldn't.

        try {

            do {

                int howmuch;

                if (isFirstRecordOfThePayload && c.needToSplitPayload()) {

                    howmuch = Math.min(0x01, r.availableDataBytes());

                } else {

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

                }

                if (isFirstRecordOfThePayload && howmuch != 0) {

                    isFirstRecordOfThePayload = false;

                }

                // NOTE: *must* call c.writeRecord() even for howmuch == 0

                if (howmuch > 0) {

                    r.write(b, off, howmuch);

                    off += howmuch;

                    len -= howmuch;

                }

                c.checkWrite();

            } while (len > 0);

        } catch (Exception e) {

            // shutdown and rethrow (wrapped) exception as appropriate

            c.handleException(e);

        }

    }

    /**

     * Write one byte now.

     */

    synchronized public void write(int i) throws IOException {

        oneByte[0] = (byte)i;

        write(oneByte, 0, 1);

    }

    /*

     * Socket close is already synchronized, no need to block here.

     */

    public void close() throws IOException {

        c.close();

    }

    // inherit no-op flush()

}