app.policy file permissions

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

For the list of available policy files that are supported by WebSphere Application Server, see the Java 2 security policy files article The app.policy file is a default policy file that is shared by all of the WAS enterprise applications. The union of the permissions that are contained in the following files is applied to the WebSphere Application Server enterprise application:

• Any policy file that is specified in the policy.url.* properties in the java.security file.

• The app.policy files, which are managed by configuration and file replication services.

• The server.policy file.

• The java.policy file.

• The application was.policy file.

• The permission specification of the ra.xml file.

• The shared library, which is the library.policy file.

Changes made in these files are replicated to other nodes in the Network Deployment cell.

In WebSphere Application Server, applications that manipulate threads 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 creates a java.security.AccessControlException exception. If an administrator adds thread permissions to app.policy, the permission change requires a restart of the WebSphere Application Server. 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"; 
}; 

Important: The Signed By and the JAAS principal keywords are not supported in app.policy. However, the Signed By keyword is supported in the following files: java.policy, server.policy, and the client.policy files. The JAAS principal keyword is supported in a JAAS policy file when it is specified by the java.security.auth.policy Java virtual machine (JVM) system property. We can statically set the authorization policy files in the java.security.auth.policy property with auth.policy.url.n=URL where URL is the location of the authorization policy.

If the default permissions for enterprise applications (the union of the permissions that is defined in the java.policy file, the server.policy file and app.policy) are enough; no action is required. The default app.policy file is used automatically. If a specific change is required to all of the enterprise applications in the cell, update app.policy. Syntax errors in the policy files cause start failures in the application servers. Edit these policy files carefully.

To extract the policy file, use a command prompt to enter the following command on one line using the appropriate variable values for your environment:

wsadmin> set obj [$AdminConfig extract profiles/profile/cells/cell/node/
node/app.policy c:/temp/test/app.policy]

Edit the extracted app.policy file with the Policy Tool. For more information, see Using PolicyTool to edit policy files . Changes to app.policy are local for the node.

To check in the policy file, use a command prompt to enter the following command on one line using the appropriate variable values for your environment:

wsadmin> $AdminConfig checkin profiles/profile/cells/cell/nodes/
node/app.policy c:/temp/test/was.policy $obj

Several product-reserved symbols are defined to associate the permission lists to a specific type of resource.

Symbol	Meaning
file:${application}	Permissions apply to all resources within the application
file:${jars}	Permissions apply to all utility Java archive (JAR) files within the application
file:${ejbComponent}	Permissions apply to enterprise bean resources within the application
file:${webComponent}	Permissions apply to Web resources within the application
file:${connectorComponent}	Permissions apply to connector resources both within the application and within standalone connector resources.

Five embedded symbols are provided to specify the path and name for the java.io.FilePermission permission. These symbols enable flexible permission specifications. The absolute file path is fixed after the installation of the application.

Symbol	Meaning
${app.installed.path}	Path where the application is installed
${was.module.path}	Path where the module is installed
${current.cell.name}	Current cell name
${current.node.name}	Current node name
${current.server.name}	Current server name

Tip: We cannot use the ${was.module.path} in the ${application} entry.

The app.policy file that is supplied by WAS resides at app_server_root/profiles/profile/config/cells/cell/nodes/node/app.policy, which contains the following default permissions: Attention: In the following code sample, the first two lines that are related to java.io.FilePermission permission are split into two lines for illustrative purposes only.

grant codeBase "file:${application}" {
  // The following are required by Java mail
  permission java.io.FilePermission "${was.install.root}${/}lib${/}mail-impl.jar", "read";
  permission java.io.FilePermission "${was.install.root}${/}lib${/}activation-impl.jar", "read";
};

grant codeBase "file:${jars}" {
  permission java.net.SocketPermission "*", "connect";
  permission java.util.PropertyPermission "*", "read";
};

grant codeBase "file:${connectorComponent}" {
  permission java.net.SocketPermission "*", "connect";
  permission java.util.PropertyPermission "*", "read";
};

grant codeBase "file:${webComponent}" {
  permission java.io.FilePermission "${was.module.path}${/}-", "read, write";
  permission java.lang.RuntimePermission "loadLibrary.*";
  permission java.lang.RuntimePermission "queuePrintJob";
  permission java.net.SocketPermission "*", "connect";
  permission java.util.PropertyPermission "*", "read";
};

grant codeBase "file:${ejbComponent}" {
 permission java.lang.RuntimePermission "queuePrintJob";
 permission java.net.SocketPermission "*", "connect";
 permission java.util.PropertyPermission "*", "read";
};

If all of the WebSphere Application Server enterprise applications in a cell require permissions that are not defined as defaults in the java.policy file, the server.policy file and app.policy, then update the app.policy file. The symptom of a missing permission is the java.security.AccessControlException exception. The missing permission is listed in the exception data, for example, java.security.AccessControlException: access denied (java.io.FilePermission C:\WebSphere\AppServer\java\jre\lib\ext\mail.jar read).

When a Java program receives this exception and adding this permission is justified, add a permission to the server.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"; };

To decide whether to add a permission, refer to the AccessControlException topic.

Restart all WAS enterprise applications to ensure that the updated app.policy file takes effect.

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Related tasks
Migrating, coexisting, and interoperating – Security considerations Using PolicyTool to edit policy files Configuring Java 2 security policy files Related reference
server.policy file permissions client.policy file permissions filter.policy file permissions java.policy file permissions

 

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