8075833: Straighter Elliptic Curves

Reviewed-by: mullan

src/share/native/sun/security/ec/impl/ec.c

 /*
- * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
  * This library is free software; you can redistribute it and/or
@@ -585,6 +585,10 @@ ECDH_Derive(SECItem  *publicValue,
         return SECFailure;
     }
 
+    if (EC_ValidatePublicKey(ecParams, publicValue, kmflag) != SECSuccess) {
+        return SECFailure;
+    }
+
     memset(derivedSecret, 0, sizeof *derivedSecret);
     len = (ecParams->fieldID.size + 7) >> 3;
     pointQ.len = 2*len + 1;