<AWT Dev> Behavior difference when open file dialog from applet

[Artem Ananiev]

Hi, Jonathan,

you're right, GTK and X file dialogs behave differently when 
SecurityManager is installed. However, instead of changing GTK dialogs, 
I propose to correct X dialogs, so they don't throw security exceptions.

Indeed, application may create arbitrary java.io.File objects without 
any permissions. File permissions are only checked when application 
tries to read from, or write into, or just open the file. AWT file 
dialogs are about getting File objects, they don't provide access to 
File content (be it a regular file or a directory), so I don't see any 
reasons to throw exceptions.

What do you think about it?

Thanks,

Artem

On 4/18/2012 11:02 AM, Jonathan Lu wrote:
> Hello, is anybody interested in this problem?
>
> it seems to be a generic question of how to control security access in
> JNI native implementation of JDK.
> And consider the behavior differences, is it neccessary to reimplement
> Gtk file dialog in the same way as X dialog?
>
> Regards
> - Jonathan
>
> On 04/11/2012 08:36 PM, Jonathan Lu wrote:
>>
>> Hi awt-dev,
>>
>> I found a behavior difference when open file dialog from an applet, bug
>> 7160238 has been created for this issue.
>> Here's the tiny test case to helping reproduce the problem,
>>
>> /*
>> * Copyright (c) 2012 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.
>> *
>> * 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.
>> */
>>
>> /*
>> * Portions Copyright (c) 2012 IBM Corporation
>> */
>>
>> import java.applet.Applet;
>> import java.awt.Button;
>> import java.awt.FileDialog;
>> import java.awt.Frame;
>> import java.awt.event.ActionEvent;
>> import java.awt.event.ActionListener;
>>
>> public class FileDialogTest extends Applet {
>> @Override
>> public void init() {
>> Button button = new Button("Open FileDialog");
>> add(button);
>> button.addActionListener(new ActionListener() {
>> @Override
>> public void actionPerformed(ActionEvent event) {
>> Frame f = new Frame();
>> FileDialog dialog = new FileDialog(f, "FileDialog");
>> dialog.show();
>> }
>> });
>> }
>> }
>>
>> Embeded it into an HTML document, test.html, then run appletviewer with
>> following two commands,
>> appletviewer -J-Dsun.awt.disableGtkFileDialogs=true test.html
>> appletviewer -J-Dsun.awt.disableGtkFileDialogs=false test.html
>>
>> The result will be different, -J-Dsun.awt.disableGtkFileDialogs=true
>> will throw AccessControlException, but
>> -J-Dsun.awt.disableGtkFileDialogs=false will continue to open a file
>> dialog.
>>
>> According to the specification:
>> The basic applet security model is an all or nothing proposition. If you
>> get a security certificate, you can give the applet full access to the
>> user's system. Without it, the applet has virtually no access at all.
>>
>> Since file dialog displays the content of user's file system, so it
>> absolutely needs file system read permmission, right? but for Gtk File
>> Dialog, it just works fine without exceptions. I don't think this
>> behavior is following the spec here, right? In OpenJDK's source code,
>> GtkFileDialogPeer will create a native GTK file chooser widget and keep
>> a native pointer, does this leave a breach to Java applet's security
>> model?
>>
>> Cheers!
>> - Jonathan
>>
>>
>