I have an applet running in jnlp. My single jar file is signed. I accept the permissions prompt each time the JNLP client is launched. I can obtain the BasicService but it still throws a url permission denied exception when I try to follow a URI:
file:///D:\temp\test.txt
The file is present on all the Windows client machines I've tried and there are no security issues with opening it.
The issue happens when using a 32 or 64-bit JRE on the client. The server is 32-bit but I would think this irrelevant. The only clue (or red-herring perhaps) is that I get no security exception when the client and server are on the same host. If I use a remote client then I get the exception.
Whilst I needed to include the jnlp.jar file to compile the code, I assume it is not needed on the client if run using Java WebStart.
What else might you need to know? What else should I try?
Later that day...
Now this may or may not be a bug, it may be something wrong with the parameters in my jnlp file but I suspect that I'm using the wrong approach. Just to reitterate I'm trying to open a file:// url.
Here is what I am now doing:
I assumed that the Desktop facilities were only available in a Desktop Application - not an applet. I was wrong (and the documentation is scant - even on this hallowed site the only reference tells me to use JNLP Services for an Applet and Desktop for an Application) - Wrong (thankfully)
So you can use Desktop (having first checked that Desktop.isDesktopSupported() of course) in an applet - as long as you are running through WebStart not embedded as an applet.
I would propose the following approach to anyone.
See if Desktop is supported and use that.
Desktop.getDesktop().open(file);
If not then see if you can get the Basic JNLP Service.
BasicService bs = (BasicService)ServiceManager.lookup("javax.jnlp.BasicService");
and if that is available the use it with boolean openedOK = bs.showDocument(url);
Finally resort to the applet API.
AppletContext context = applet.getAppletContext();
context.showDocument(url, targetFrame);
Related
I have a server where I work with a database and files using a java app.
When I start my app I give a report regarding file access to the server using:
public static boolean folderExists(String folderPath) {
File folderToCheck = new File(folderPath);
return folderToCheck.exists();
}
Every time I start my app (after a fresh restart of my computer)
I get a false response, even though the server is on.
The reason is because I must give an authentication as another user.
What I do is access the server through Windows
where I am being asked for username/password,
and after that I get a true response regarding file access to the server.
Is there a way to give the authentication username/password through Java,
and not through Windows?
Thank you
On Windows 'native' Java IO (e.g. java.io.File) always inherits the security context of the user running the JVM process. For example, you could run the Java app as a Windows service with the correct credentials.
The JCIFS project implements CIFS (the Windows SMB file server protocol) and allows you to directly specify the username/password.
See the API for examples.
I am pretty sure, that there is no way to grant fileaccess by java, without a Windows-Call.
You can call cacls file.log /e /t /p Everyone:f but this will be language-dependent.
I had a similar problem: How to change the file ACL in windows, if I only know the SID?
With Java7 there may be a way to do this.
I am creating a Java webstart application which will be downloaded as JNLP and will run at the local machine. Purpose is to read some info about local files.
But the issue is I am getting a warning message for security. After adding the site address to Java control panel, the warning message went off.
I have automated this by altering the exception.sites file located in C:\Users\<username>\AppData\LocalLow\Sun\Java\Deployment\security in Windows OS.
Where this file (exception.sites) exists in LINUX and MAC machine?
The location of the exception site list is set in the deployment.user.security.exception.sites property. The default location is {deployment.user.home}/security/exception.sites.
See http://docs.oracle.com/javase/7/docs/technotes/guides/jweb/security/exception_site_list.html
Also good to know: http://docs.oracle.com/javase/7/docs/technotes/guides/jweb/jcp/properties.html
I am working in bigbluebutton 0.8.1. I had setup the development environment in my local(ubuntu 10.04) and desktop sharing is working fine.
Later i created new bbb-desktop-applet jar, using the url https://code.google.com/p/bigbluebutton/wiki/081DevelopingBigBlueButton#Developing_Deskshare. And then moved the newly created jar to this location var/www/bigbluebutton/client in ubuntu machine and then restarted the server. I can able to create and join the room, but not able to share my desktop, getting below error. Already I added the url in exception site list in java control panel but still it is not working.i stuck up with this issue.
I'm one of the developers of BigBlueButton.
You need to sign the modified desktop sharing jar file with a valid code signing certificate (not a self-signed certificate); otherwise, the browser will give you a very strong warning (such as the above) that warns the user they are trying to run an untrusted applet.
This is not a security issue with BigBlueButton; rather, it's the absence of a valid certificate signature with your modified desktop sharing applet.
Regards,... Fred
I have a server where I work with a database and files using a java app.
When I start my app I give a report regarding file access to the server using:
public static boolean folderExists(String folderPath) {
File folderToCheck = new File(folderPath);
return folderToCheck.exists();
}
Every time I start my app (after a fresh restart of my computer)
I get a false response, even though the server is on.
The reason is because I must give an authentication as another user.
What I do is access the server through Windows
where I am being asked for username/password,
and after that I get a true response regarding file access to the server.
Is there a way to give the authentication username/password through Java,
and not through Windows?
Thank you
On Windows 'native' Java IO (e.g. java.io.File) always inherits the security context of the user running the JVM process. For example, you could run the Java app as a Windows service with the correct credentials.
The JCIFS project implements CIFS (the Windows SMB file server protocol) and allows you to directly specify the username/password.
See the API for examples.
I am pretty sure, that there is no way to grant fileaccess by java, without a Windows-Call.
You can call cacls file.log /e /t /p Everyone:f but this will be language-dependent.
I had a similar problem: How to change the file ACL in windows, if I only know the SID?
With Java7 there may be a way to do this.
I have a client-side security policy, with a statement that grants permissions. I want to be able to specify it to grant the set of permissions for an RMI server only. For example this works:
grant{
//my permissions
};
But I cant figure out how to link the set of permissions so that they apply to my codebase on the server. Actually anything, as long as its tied to the server would be fine. I have tried:
grant codeBase "file://hostname/-"{
//my permissions
};
With the hostname being the name or IP of the machine, both with and w/o the port number. But this does not work, neither does using http instead of file. If I understand what I read so far correctly the hyphen at the end should apply the permissions to anything located on the server. Anyone know what I need to do to get this to work?
Thanks.
Heres the codebase specified when running the server:
-Djava.rmi.server.codebase=file://home/me/PageServer/build/classes/ pageserver.LoginService pageserver.PlannerService
Where is the local JVM getting the code that should be granted permissions?
If it's downloading the code from an HTTP codebase on the server, you can use a URL starting with "http:".
If it's local code, you can use a URL starting with "file:" and ending with a local path.
Disclaimer: I've written security files for Jini, which is built atop RMI, and it's been a few years. Apologies for anything I've missed.
Use a JAR for the codebase, and specify exactly the HTTP URL in the .policy file that you specified in -Djava.rmi.server.codebase.