Configure Java 2 security policy files

 

Before you begin

Java 2 security uses several policy files to determine the granted permissions for each Java program.

There are two types of policy files supported by WAS (WAS):

  • dynamic policy files
  • static policy files

Static policy files provide the default permissions. Dynamic policy files provide application permissions. There are six dynamic policy files:

Policy file name Description
app.policy Contains default permissions for all of the enterprise applications in the cell.
was.policy Contains application-specific permissions for an WAS enterprise application. This file is packaged in an EAR file.
ra.xml Contains connector application specific permissions for a WAS enterprise application. This file is packaged in a resource adapter archive (RAR) file.
spi.policy Contains permissions for Service Provider Interface (SPI) or third-party resources embedded in WAS. The default contents grant everything. Update this file carefully when the cell requires more protection against SPI in the cell. This file is applied to all of the SPIs defined in the resources.xml file.
library.policy Contains permissions for the shared library of enterprise applications.
filter.policy Contains the list of permissions that require filtering from the was.policy file and the app.policy file in the cell. This filtering mechanism only applies to the was.policy and app.policy files.

In WAS, applications must have the appropriate thread permissions specified in the was.policy or app.policy file. Without the thread permissions specified, the application cannot manipulate threads and WAS throws a java.security.AccessControlException. The app.policy file applies to a specified node. If you change the permissions in one app.policy file, incorporate the new thread policy in the same file on the remaining nodes. Also, if you add the thread permissions to the app.policy file, restart WAS to enforce the new permissions. However, if you add the permissions to the was.policy file for a specific application, you do not need to restart WAS. An administrator must add the following code to a was.policy or app.policy file for an application to manipulate threads: 

grant codeBase "file:${application}" {
permission java.lang.RuntimePermission "stopThread";
permission java.lang.RuntimePermission "modifyThread";
permission java.lang.RuntimePermission "modifyThreadGroup";
};

The Signed By keyword is not supported in the following policy files:

However, the Signed By keyword is supported in the following policy files:

The Java Authentication and Authorization Service (JAAS) is not supported in...

However, the JAAS principal keyword is supported in a JAAS policy file when it is specified by the JVM system property, java.security.auth.policy. We can statically set the authorization policy files in java.security.auth.policy with auth.policy.url.n=URL where URL is the location of the authorization policy.

 

Procedure

  1. Identify the policy file to update.

    Note: It is recommended to pick up the policy file with the smallest scope. We can avoid giving an extra permission to the Java programs and protect the resources. We can update the ra.xml file or the was.policy file rather than the app.policy file. Use specific component symbols ($(ejbcomponent), ${webComponent},${connectorComponent} and ${jars}) than ${application} symbols. Update dynamic policy files than static policy files.

    Add any permission that should never be granted to the WAS enterprise application in the cell to the filter.policy file. Refer to Configuring filter.policy files.

  2. Restart the WAS enterprise application.

 

Result

The required permission is granted for the specified WAS enterprise application.

 

Example

java.security.AccessControlException: access denied (java.io.FilePermission 
C:\WebSphere\AppServer\java\jre\lib\ext\mail.jar read)

The previous two lines were split onto two lines because of the width of the page. However, the permission should be on one line.

When a Java program receives this exception and adding this permission is justified, add a permission to an adequate dynamic policy file, for example, 

grant codeBase "file:<user client installed location>" { 
permission java.io.FilePermission 
"C:\WebSphere\AppServer\java\jre\lib\ext\mail.jar", "read";
};

The previous two lines were split onto two lines because of the width of the page. However, the permission should be on one line.

To decide whether to add a permission, refer to the article Access control exception.

 

See also

Configuring app.policy files
Configuring filter.policy files
Configuring the was.policy file
Configuring spi.policy files
Configuring library.policy files
Adding the was.policy file to applications

 

See Also

Java 2 security policy files
Access control exception

 

Related Tasks

Migrating security configurations from previous releases
Configuring static policy files

 

See Also


Java 2 security