--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/sun/security/ssl/KAKeyDerivation.java	Wed Jun 12 18:58:00 2019 -0700
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2019, 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 javax.crypto.KeyAgreement;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.SecretKeySpec;
+import javax.net.ssl.SSLHandshakeException;
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+import java.security.spec.AlgorithmParameterSpec;
+
+/**
+ * A common class for creating various KeyDerivation types.
+ */
+public class KAKeyDerivation implements SSLKeyDerivation {
+
+    private final String algorithmName;
+    private final HandshakeContext context;
+    private final PrivateKey localPrivateKey;
+    private final PublicKey peerPublicKey;
+
+    KAKeyDerivation(String algorithmName,
+            HandshakeContext context,
+            PrivateKey localPrivateKey,
+            PublicKey peerPublicKey) {
+        this.algorithmName = algorithmName;
+        this.context = context;
+        this.localPrivateKey = localPrivateKey;
+        this.peerPublicKey = peerPublicKey;
+    }
+
+    @Override
+    public SecretKey deriveKey(String algorithm,
+            AlgorithmParameterSpec params) throws IOException {
+        if (!context.negotiatedProtocol.useTLS13PlusSpec()) {
+            return t12DeriveKey(algorithm, params);
+        } else {
+            return t13DeriveKey(algorithm, params);
+        }
+    }
+
+    /**
+     * Handle the TLSv1-1.2 objects, which don't use the HKDF algorithms.
+     */
+    private SecretKey t12DeriveKey(String algorithm,
+            AlgorithmParameterSpec params) throws IOException {
+        try {
+            KeyAgreement ka = KeyAgreement.getInstance(algorithmName);
+            ka.init(localPrivateKey);
+            ka.doPhase(peerPublicKey, true);
+            SecretKey preMasterSecret
+                    = ka.generateSecret("TlsPremasterSecret");
+            SSLMasterKeyDerivation mskd
+                    = SSLMasterKeyDerivation.valueOf(
+                            context.negotiatedProtocol);
+            if (mskd == null) {
+                // unlikely
+                throw new SSLHandshakeException(
+                        "No expected master key derivation for protocol: "
+                        + context.negotiatedProtocol.name);
+            }
+            SSLKeyDerivation kd = mskd.createKeyDerivation(
+                    context, preMasterSecret);
+            return kd.deriveKey("MasterSecret", params);
+        } catch (GeneralSecurityException gse) {
+            throw (SSLHandshakeException) new SSLHandshakeException(
+                    "Could not generate secret").initCause(gse);
+        }
+    }
+
+    /**
+     * Handle the TLSv1.3 objects, which use the HKDF algorithms.
+     */
+    private SecretKey t13DeriveKey(String algorithm,
+            AlgorithmParameterSpec params) throws IOException {
+        try {
+            KeyAgreement ka = KeyAgreement.getInstance(algorithmName);
+            ka.init(localPrivateKey);
+            ka.doPhase(peerPublicKey, true);
+            SecretKey sharedSecret
+                    = ka.generateSecret("TlsPremasterSecret");
+
+            CipherSuite.HashAlg hashAlg = context.negotiatedCipherSuite.hashAlg;
+            SSLKeyDerivation kd = context.handshakeKeyDerivation;
+            HKDF hkdf = new HKDF(hashAlg.name);
+            if (kd == null) {   // No PSK is in use.
+                // If PSK is not in use Early Secret will still be
+                // HKDF-Extract(0, 0).
+                byte[] zeros = new byte[hashAlg.hashLength];
+                SecretKeySpec ikm
+                        = new SecretKeySpec(zeros, "TlsPreSharedSecret");
+                SecretKey earlySecret
+                        = hkdf.extract(zeros, ikm, "TlsEarlySecret");
+                kd = new SSLSecretDerivation(context, earlySecret);
+            }
+
+            // derive salt secret
+            SecretKey saltSecret = kd.deriveKey("TlsSaltSecret", null);
+
+            // derive handshake secret
+            return hkdf.extract(saltSecret, sharedSecret, algorithm);
+        } catch (GeneralSecurityException gse) {
+            throw (SSLHandshakeException) new SSLHandshakeException(
+                    "Could not generate secret").initCause(gse);
+        }
+    }
+}