[fix] avoid PKey::EC.new failing with specific DER (#318)

Author: kares

src/main/java/org/jruby/ext/openssl/PKeyEC.java

@@ -171,7 +171,10 @@ public static RubyArray builtin_curves(ThreadContext context, IRubyObject self)
         return curves;
     }
 
-    private static Optional<ASN1ObjectIdentifier> getCurveOID(final String curveName) {
+    private static Optional<ASN1ObjectIdentifier> getCurveOID(String curveName) {
+        if (curveName == null) return Optional.empty();
+        // work-around getNamedCurveOid not being able to handle "... " (assuming spacePos + 1 is valid index)
+        if (curveName.indexOf(' ') == curveName.length() - 1) return Optional.empty();
         return Optional.ofNullable(ECUtil.getNamedCurveOid(curveName));
     }