diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/java.base/share/classes/sun/security/ssl/ProtocolVersion.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/sun/security/ssl/ProtocolVersion.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,315 @@
+/*
+ * Copyright (c) 2002, 2015, 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.util.*;
+import java.security.CryptoPrimitive;
+import sun.security.ssl.CipherSuite.*;
+
+/**
+ * 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:
+ *
+ * <pre>{@code
+ * if (protocolVersion.v >= ProtocolVersion.TLS10) {
+ *   // TLS 1.0 code goes here
+ * } else {
+ *   // SSL 3.0 code here
+ * }
+ * }</pre>
+ *
+ * @author  Andreas Sterbenz
+ * @since   1.4.1
+ */
+public final class ProtocolVersion implements Comparable<ProtocolVersion> {
+
+    // The limit of maximum protocol version
+    static final int LIMIT_MAX_VALUE = 0xFFFF;
+
+    // The limit of minimum protocol version
+    static final int LIMIT_MIN_VALUE = 0x0000;
+
+    // Dummy protocol version value for invalid SSLSession
+    static final ProtocolVersion NONE = new ProtocolVersion(-1, "NONE");
+
+    // If enabled, send/accept SSLv2 hello messages
+    static final ProtocolVersion SSL20Hello =
+                                new ProtocolVersion(0x0002, "SSLv2Hello");
+
+    // SSL 3.0
+    static final ProtocolVersion SSL30 = new ProtocolVersion(0x0300, "SSLv3");
+
+    // TLS 1.0
+    static final ProtocolVersion TLS10 = new ProtocolVersion(0x0301, "TLSv1");
+
+    // TLS 1.1
+    static final ProtocolVersion TLS11 = new ProtocolVersion(0x0302, "TLSv1.1");
+
+    // TLS 1.2
+    static final ProtocolVersion TLS12 = new ProtocolVersion(0x0303, "TLSv1.2");
+
+    // DTLS 1.0
+    // {254, 255}, the version value of DTLS 1.0.
+    static final ProtocolVersion DTLS10 =
+                                new ProtocolVersion(0xFEFF, "DTLSv1.0");
+
+    // No DTLS 1.1, that version number was skipped in order to harmonize
+    // version numbers with TLS.
+
+    // DTLS 1.2
+    // {254, 253}, the version value of DTLS 1.2.
+    static final ProtocolVersion DTLS12 =
+                                new ProtocolVersion(0xFEFD, "DTLSv1.2");
+
+    private static final boolean FIPS = SunJSSE.isFIPS();
+
+    // minimum version we implement (SSL 3.0)
+    static final ProtocolVersion MIN = FIPS ? TLS10 : SSL30;
+
+    // maximum version we implement (TLS 1.2)
+    static final ProtocolVersion MAX = TLS12;
+
+    // SSL/TLS ProtocolVersion to use by default (TLS 1.2)
+    static final ProtocolVersion DEFAULT_TLS = TLS12;
+
+    // DTLS ProtocolVersion to use by default (TLS 1.2)
+    static final ProtocolVersion DEFAULT_DTLS = DTLS12;
+
+    // Default version for hello messages (SSLv2Hello)
+    static final ProtocolVersion DEFAULT_HELLO = FIPS ? TLS10 : SSL30;
+
+    // Available protocols
+    //
+    // Including all supported protocols except the disabled ones.
+    static final Set<ProtocolVersion> availableProtocols;
+
+    // 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;
+
+    // Initialize the available protocols.
+    static {
+        Set<ProtocolVersion> protocols = new HashSet<>(7);
+
+        ProtocolVersion[] pvs = new ProtocolVersion[] {
+                SSL20Hello, SSL30, TLS10, TLS11, TLS12, DTLS10, DTLS12};
+        EnumSet<CryptoPrimitive> cryptoPrimitives =
+            EnumSet.<CryptoPrimitive>of(CryptoPrimitive.KEY_AGREEMENT);
+        for (ProtocolVersion p : pvs) {
+            if (SSLAlgorithmConstraints.DEFAULT_SSL_ONLY.permits(
+                    cryptoPrimitives, p.name, null)) {
+                protocols.add(p);
+            }
+        }
+
+        availableProtocols =
+                Collections.<ProtocolVersion>unmodifiableSet(protocols);
+    }
+
+    // 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 if (v == DTLS10.v) {
+            return DTLS10;
+        } else if (v == DTLS12.v) {
+            return DTLS12;
+        } 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) {
+        return valueOf(((major & 0xFF) << 8) | (minor & 0xFF));
+    }
+
+    /**
+     * 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 if (name.equals(DTLS10.name)) {
+            return DTLS10;
+        } else if (name.equals(DTLS12.name)) {
+            return DTLS12;
+        } else {
+            throw new IllegalArgumentException(name);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+
+    /**
+     * Compares this object with the specified object for order.
+     */
+    @Override
+    public int compareTo(ProtocolVersion protocolVersion) {
+        if (maybeDTLSProtocol()) {
+            if (!protocolVersion.maybeDTLSProtocol()) {
+                throw new IllegalArgumentException("Not DTLS protocol");
+            }
+
+            return protocolVersion.v - this.v;
+        } else {
+            if (protocolVersion.maybeDTLSProtocol()) {
+                throw new IllegalArgumentException("Not TLS protocol");
+            }
+
+            return this.v - protocolVersion.v;
+        }
+    }
+
+    /**
+     * Returns true if a ProtocolVersion represents a DTLS protocol.
+     */
+    boolean isDTLSProtocol() {
+        return this.v == DTLS12.v || this.v == DTLS10.v;
+    }
+
+    /**
+     * Returns true if a ProtocolVersion may represent a DTLS protocol.
+     */
+    boolean maybeDTLSProtocol() {
+        return (this.major & 0x80) != 0;
+    }
+
+    boolean useTLS12PlusSpec() {
+        return maybeDTLSProtocol() ? (this.v <= DTLS12.v) : (this.v >= TLS12.v);
+    }
+
+    boolean useTLS11PlusSpec() {
+        return maybeDTLSProtocol() ? true : (this.v >= TLS11.v);
+    }
+
+    boolean useTLS10PlusSpec() {
+        return maybeDTLSProtocol() ? true : (this.v >= TLS10.v);
+    }
+
+    boolean obsoletes(CipherSuite suite) {
+        ProtocolVersion proto = this;
+        if (proto.isDTLSProtocol()) {
+            // DTLS bans stream ciphers.
+            if (suite.cipher.cipherType == CipherType.STREAM_CIPHER) {
+                return true;
+            }
+
+            proto = mapToTLSProtocol(this);
+        }
+
+        return (proto.v >= suite.obsoleted);
+    }
+
+    boolean supports(CipherSuite suite) {
+        ProtocolVersion proto = this;
+        if (proto.isDTLSProtocol()) {
+            // DTLS bans stream ciphers.
+            if (suite.cipher.cipherType == CipherType.STREAM_CIPHER) {
+                return false;
+            }
+
+            proto = mapToTLSProtocol(this);
+        }
+
+        return (proto.v >= suite.supported);
+    }
+
+    // Map a specified protocol to the corresponding TLS version.
+    //
+    // DTLS 1.2 -> TLS 1.2
+    // DTLS 1.0 -> TLS 1.1
+    private static ProtocolVersion mapToTLSProtocol(
+            ProtocolVersion protocolVersion) {
+
+        if (protocolVersion.isDTLSProtocol()) {
+            if (protocolVersion.v == DTLS10.v) {
+                protocolVersion = TLS11;
+            } else {    // DTLS12
+                protocolVersion = TLS12;
+            }
+        }
+
+        return protocolVersion;
+    }
+}