--- old/jdk/src/jdk.crypto.ec/share/classes/sun/security/ec/ECKeyPairGenerator.java	2017-07-10 10:27:06.325918000 -0400
+++ new/jdk/src/jdk.crypto.ec/share/classes/sun/security/ec/ECKeyPairGenerator.java	2017-07-10 10:27:06.225868000 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2009, 2017, 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
@@ -25,12 +25,14 @@
 
 package sun.security.ec;
 
+import java.io.IOException;
 import java.math.BigInteger;
 import java.security.*;
 import java.security.spec.AlgorithmParameterSpec;
 import java.security.spec.ECGenParameterSpec;
 import java.security.spec.ECParameterSpec;
 import java.security.spec.ECPoint;
+import java.security.spec.InvalidParameterSpecException;
 
 import sun.security.ec.ECPrivateKeyImpl;
 import sun.security.ec.ECPublicKeyImpl;
@@ -85,17 +87,19 @@
     public void initialize(AlgorithmParameterSpec params, SecureRandom random)
             throws InvalidAlgorithmParameterException {
 
+        ECParameterSpec ecSpec = null;
+ 
         if (params instanceof ECParameterSpec) {
-            this.params = ECUtil.getECParameterSpec(null,
+            ecSpec = ECUtil.getECParameterSpec(null,
                                                     (ECParameterSpec)params);
-            if (this.params == null) {
+            if (ecSpec == null) {
                 throw new InvalidAlgorithmParameterException(
                     "Unsupported curve: " + params);
             }
         } else if (params instanceof ECGenParameterSpec) {
             String name = ((ECGenParameterSpec)params).getName();
-            this.params = ECUtil.getECParameterSpec(null, name);
-            if (this.params == null) {
+            ecSpec = ECUtil.getECParameterSpec(null, name);
+            if (ecSpec == null) {
                 throw new InvalidAlgorithmParameterException(
                     "Unknown curve name: " + name);
             }
@@ -103,11 +107,36 @@
             throw new InvalidAlgorithmParameterException(
                 "ECParameterSpec or ECGenParameterSpec required for EC");
         }
+
+        // Not all known curves are supported by the native implementation
+        ensureCurveIsSupported(ecSpec);
+        this.params = ecSpec;
+
         this.keySize =
             ((ECParameterSpec)this.params).getCurve().getField().getFieldSize();
         this.random = random;
     }
 
+    private static void ensureCurveIsSupported(ECParameterSpec ecSpec)
+        throws InvalidAlgorithmParameterException {
+        
+        AlgorithmParameters ecParams = ECUtil.getECParameters(null);
+        byte[] encodedParams;
+        try {
+            ecParams.init(ecSpec);
+            encodedParams = ecParams.getEncoded();
+        } catch (InvalidParameterSpecException ex) {
+            throw new InvalidAlgorithmParameterException(
+                "Unsupported curve: " + ecSpec.toString());
+        } catch (IOException ex) {
+            throw new RuntimeException(ex);
+        }
+        if (!isCurveSupported(encodedParams)) {
+            throw new InvalidAlgorithmParameterException(
+                "Unsupported curve: " + ecParams.toString());
+        }
+    }
+
     // generate the keypair. See JCA doc
     @Override
     public KeyPair generateKeyPair() {
@@ -159,6 +188,17 @@
         this.keySize = keySize;
     }
 
+    /**
+     * Checks whether the curve in the encoded parameters is supported by the
+     * native implementation. 
+     *
+     * @param encodedParams encoded parameters in the same form accepted 
+     *    by generateECKeyPair
+     * @return true if and only if generateECKeyPair will succeed for
+     *    the supplied parameters
+     */
+    private static native boolean isCurveSupported(byte[] encodedParams);
+
     /*
      * Generates the keypair and returns a 2-element array of encoding bytes.
      * The first one is for the private key, the second for the public key.