/* * Copyright (c) 2002, 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 * questions. */ package sun.security.ssl; /** * Type safe enum for an SSL/TLS protocol version. Instances are obtained * using the static factory methods or by referencing the static members * in this class. Member variables are final and can be accessed without * accessor methods. * * There is only ever one instance per supported protocol version, this * means == can be used for comparision instead of equals() if desired. * * Checks for a particular version number should generally take this form: * * if (protocolVersion.v >= ProtocolVersion.TLS10) { *   // TLS 1.0 code goes here * } else { *   // SSL 3.0 code here * } * * @author  Andreas Sterbenz * @since   1.4.1 */public final class ProtocolVersion implements Comparable<ProtocolVersion> {     // The limit of maximum protocol version    final static int LIMIT_MAX_VALUE = 0xFFFF;     // The limit of minimum protocol version    final static int LIMIT_MIN_VALUE = 0x0000;     // Dummy protocol version value for invalid SSLSession    final static ProtocolVersion NONE = new ProtocolVersion(-1, "NONE");     // If enabled, send/ accept SSLv2 hello messages    final static ProtocolVersion SSL20Hello = new ProtocolVersion(0x0002,                                                                "SSLv2Hello");     // SSL 3.0    final static ProtocolVersion SSL30 = new ProtocolVersion(0x0300, "SSLv3");     // TLS 1.0    final static ProtocolVersion TLS10 = new ProtocolVersion(0x0301, "TLSv1");     // TLS 1.1    final static ProtocolVersion TLS11 = new ProtocolVersion(0x0302, "TLSv1.1");     // TLS 1.2    final static ProtocolVersion TLS12 = new ProtocolVersion(0x0303, "TLSv1.2");     private static final boolean FIPS = SunJSSE.isFIPS();     // minimum version we implement (SSL 3.0)    final static ProtocolVersion MIN = FIPS ? TLS10 : SSL30;     // maximum version we implement (TLS 1.2)    final static ProtocolVersion MAX = TLS12;     // ProtocolVersion to use by default (TLS 1.0)    final static ProtocolVersion DEFAULT = TLS10;     // Default version for hello messages (SSLv2Hello)    final static ProtocolVersion DEFAULT_HELLO = FIPS ? TLS10 : SSL30;     // version in 16 bit MSB format as it appears in records and    // messages, i.e. 0x0301 for TLS 1.0    public final int v;     // major and minor version    public final byte major, minor;     // name used in JSSE (e.g. TLSv1 for TLS 1.0)    final String name;     // private    private ProtocolVersion(int v, String name) {        this.v = v;        this.name = name;        major = (byte)(v >>> 8);        minor = (byte)(v & 0xff);    }     // private    private static ProtocolVersion valueOf(int v) {        if (v == SSL30.v) {            return SSL30;        } else if (v == TLS10.v) {            return TLS10;        } else if (v == TLS11.v) {            return TLS11;        } else if (v == TLS12.v) {            return TLS12;        } else if (v == SSL20Hello.v) {            return SSL20Hello;        } else {            int major = (v >>> 8) & 0xff;            int minor = v & 0xff;            return new ProtocolVersion(v, "Unknown-" + major + "." + minor);        }    }     /**     * Return a ProtocolVersion with the specified major and minor version     * numbers. Never throws exceptions.     */    public static ProtocolVersion valueOf(int major, int minor) {        major &= 0xff;        minor &= 0xff;        int v = (major << 8) | minor;        return valueOf(v);    }     /**     * Return a ProtocolVersion for the given name.     *     * @exception IllegalArgumentException if name is null or does not     * identify a supported protocol     */    static ProtocolVersion valueOf(String name) {        if (name == null) {            throw new IllegalArgumentException("Protocol cannot be null");        }         if (FIPS && (name.equals(SSL30.name) || name.equals(SSL20Hello.name))) {            throw new IllegalArgumentException                ("Only TLS 1.0 or later allowed in FIPS mode");        }         if (name.equals(SSL30.name)) {            return SSL30;        } else if (name.equals(TLS10.name)) {            return TLS10;        } else if (name.equals(TLS11.name)) {            return TLS11;        } else if (name.equals(TLS12.name)) {            return TLS12;        } else if (name.equals(SSL20Hello.name)) {            return SSL20Hello;        } else {            throw new IllegalArgumentException(name);        }    }     public String toString() {        return name;    }     /**     * Compares this object with the specified object for order.     */    public int compareTo(ProtocolVersion protocolVersion) {        return this.v - protocolVersion.v;    }}