src/java.base/share/classes/sun/security/ssl/Handshaker.java

*** 223,232 ****
--- 223,236 ----
      // By default, allow client initiated renegotiations.
      static final boolean rejectClientInitiatedRenego =
              Debug.getBooleanProperty(
                  "jdk.tls.rejectClientInitiatedRenegotiation", false);
  
+     // To switch off the extended_master_secret extension.
+     static final boolean useExtendedMasterSecretExtension =
+             Debug.getBooleanProperty("jsse.useExtendedMasterSecret", true);
+ 
      // need to dispose the object when it is invalidated
      boolean invalidated;
  
      /*
       * Is this an instance for Datagram Transport Layer Security (DTLS)?
*** 1274,1287 ****
  
          String prfHashAlg = prf.getPRFHashAlg();
          int prfHashLength = prf.getPRFHashLength();
          int prfBlockSize = prf.getPRFBlockSize();
  
          @SuppressWarnings("deprecation")
          TlsMasterSecretParameterSpec spec = new TlsMasterSecretParameterSpec(
                  preMasterSecret, (majorVersion & 0xFF), (minorVersion & 0xFF),
!                 clnt_random.random_bytes, svr_random.random_bytes,
                  prfHashAlg, prfHashLength, prfBlockSize);
  
          try {
              KeyGenerator kg = JsseJce.getKeyGenerator(masterAlg);
              kg.init(spec);
--- 1278,1296 ----
  
          String prfHashAlg = prf.getPRFHashAlg();
          int prfHashLength = prf.getPRFHashLength();
          int prfBlockSize = prf.getPRFBlockSize();
  
+         byte[] sessionHash = null;
+         if (session.getUseExtendedMasterSecret()){
+             sessionHash = handshakeHash.getFinishedHash();
+         }
+ 
          @SuppressWarnings("deprecation")
          TlsMasterSecretParameterSpec spec = new TlsMasterSecretParameterSpec(
                  preMasterSecret, (majorVersion & 0xFF), (minorVersion & 0xFF),
!                 clnt_random.random_bytes, svr_random.random_bytes, sessionHash,
                  prfHashAlg, prfHashLength, prfBlockSize);
  
          try {
              KeyGenerator kg = JsseJce.getKeyGenerator(masterAlg);
              kg.init(spec);