/*

 * Copyright (c) 1996, 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

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

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 */

package sun.security.ssl;

/**

 * SSL/TLS records, as pulled off (and put onto) a TCP stream.  This is

 * the base interface, which defines common information and interfaces

 * used by both Input and Output records.

 *

 * @author David Brownell

 */

interface Record {

    /*

     * There are four SSL record types, which are part of the interface

     * to this level (along with the maximum record size)

     *

     * enum { change_cipher_spec(20), alert(21), handshake(22),

     *      application_data(23), (255) } ContentType;

     */

    static final byte   ct_change_cipher_spec = 20;

    static final byte   ct_alert = 21;

    static final byte   ct_handshake = 22;

    static final byte   ct_application_data = 23;

    static final int    headerSize = 5;         // SSLv3 record header

    static final int    maxExpansion = 1024;    // for bad compression

    static final int    trailerSize = 20;       // SHA1 hash size

    static final int    maxDataSize = 16384;    // 2^14 bytes of data

    static final int    maxPadding = 256;       // block cipher padding

    static final int    maxIVLength = 256;      // block length

    /*

     * SSL has a maximum record size.  It's header, (compressed) data,

     * padding, and a trailer for the MAC.

     * Some compression algorithms have rare cases where they expand the data.

     * As we don't support compression at this time, leave that out.

     */

    static final int    maxRecordSize =

                                      headerSize        // header

                                    + maxIVLength       // iv

                                    + maxDataSize       // data

                                    + maxPadding        // padding

                                    + trailerSize;      // MAC

    /*

     * The maximum large record size.

     *

     * Some SSL/TLS implementations support large fragment upto 2^15 bytes,

     * such as Microsoft. We support large incoming fragments.

     *

     * The maximum large record size is defined as maxRecordSize plus 2^14,

     * this is the amount OpenSSL is using.

     */

    static final int    maxLargeRecordSize =

                maxRecordSize   // Max size with a conforming implemenation

              + maxDataSize;    // extra 2^14 bytes for large data packets.

    /*

     * Maximum record size for alert and change cipher spec records.

     * They only contain 2 and 1 bytes of data, respectively.

     * Allocate a smaller array.

     */

    static final int    maxAlertRecordSize =

                                      headerSize        // header

                                    + maxIVLength       // iv

                                    + 2                 // alert

                                    + maxPadding        // padding

                                    + trailerSize;      // MAC

}