How To Configure WebApp Minimal File Access Permissions

WebApp requires access to the following file resources:

READ access to the directory where the WebApp is deployed.
READ and WRITE access to the application's working directory.
READ and WRITE access to JVM's temporary directory.

It is a good security practice to allow a component to access only the information and resources that are necessary for its purpose. In an environment that uses Apache Tomcat, you can enforce these rules following these steps:

Start the Apache Tomcat server using the -security flag.

Edit the catalina.policy file and add the following snippet:

grant codeBase "file:${catalina.base}/webapps/oxygen-webapp/-" {
    // Oxygen uses System properties for various configuration purposes.
    permission java.util.PropertyPermission "*", "read,write";
    // Oxygen custom protocols need access to network.
    permission java.net.NetPermission "*";
    permission java.net.SocketPermission "*", "accept,connect,listen,resolve";
    // The web framework used by Oxygen Webapp uses reflection and classloaders.
    permission java.lang.reflect.ReflectPermission "suppressAccessChecks";
    permission java.lang.RuntimePermission "*";
	
    // Oxygen uses the JVM's java.io.tempdir for various file handling tasks.
    permission java.io.FilePermission "${java.io.tmpdir}/-", "read,write,delete"; 
};

Note: In the previous example, in the first line, replace oxygen-webapp with the name of your deployment of Oxygen XML WebApp.

Configuring File Permissions to Custom Locations

There are cases when Oxygen XML WebApp needs to access files system resources, but, due to security reasons, you want to prevent your users to open them directly in the WebApp's editing page using the file:// protocol.

You can do this by following these steps:

Edit the catalina.policy file and add a line such as:

permission java.io.FilePermission "path/to/yourSecretDir/-", "read,write,delete";

Use the following system property when starting the Tomcat server:
```
-Dfile.protocol.blacklist=/path/to/yourSecretDir
```
Note: Use the value of path.separator system property to separate more directories. For example, under Linux, the value of path.separator property is a colon punctuation character :.