How Do I Attach an Authorization Scheme to an Application in Oracle APEX

Introduction

Attaching an authorization scheme to an application in Oracle APEX is a key step in securing your application, ensuring that only authorized users can access specific pages, regions, buttons, or other components. Authorization schemes define the access rules for authenticated users, allowing developers to enforce role-based or condition-based permissions. By attaching these schemes to various application components, you can create a robust and flexible security model. This blog post will guide you through the process of attaching an authorization scheme to an Oracle APEX application, provide detailed steps, share best practices, and link to the official Oracle APEX documentation for further reference.

Steps to Attach an Authorization Scheme to an Application in Oracle APEX

1. Understanding Authorization Schemes
   Authorization schemes in Oracle APEX are reusable rules defined in Shared Components that determine whether a user has permission to access specific application components. These schemes use SQL queries, PL/SQL functions, or other conditions to evaluate access rights and can be applied to pages, regions, buttons, or items.

2. Creating an Authorization Scheme
   Before attaching a scheme, you must create one:

   • Navigate to Shared Components > Authorization Schemes in your Oracle APEX application.
   • Click Create to define a new scheme. Provide a name (e.g., "Admin_Access" or "Viewer_Role") and select a scheme type, such as:
     • Exists SQL Query: Grants access if the query returns at least one row. Example:

       SELECT 1
       FROM user_roles
       WHERE username = :APP_USER
       AND role_name = 'ADMIN';
       

     • PL/SQL Function Returning Boolean: Returns TRUE if the user is authorized. Example:

       FUNCTION is_editor (p_username IN VARCHAR2) RETURN BOOLEAN IS
         l_count NUMBER;
       BEGIN
         SELECT COUNT(*) INTO l_count
         FROM user_roles
         WHERE username = p_username
         AND role_name = 'EDITOR';
         RETURN l_count > 0;
       END;
       

   • Set the evaluation frequency (e.g., "Once per Session" for static roles or "Once per Page View" for dynamic checks).
   • Specify an error message (e.g., "Access Denied: Insufficient Privileges") to display when access is denied.

3. Attaching Authorization Schemes to Application Components
   Once created, attach the authorization scheme to specific components:

   • Pages:
     • Open the page in Page Designer.
     • In the Security tab of the page properties, locate the Authorization Scheme field.
     • Select the desired scheme (e.g., "Admin_Access") from the dropdown.
     • Save the changes. This restricts the entire page to users who satisfy the scheme.
   • Regions:
     • In Page Designer, select the region.
     • Under the Security tab, set the Authorization Scheme to the appropriate scheme.
     • This controls visibility or interactivity of the region based on user permissions.
   • Buttons:
     • Select the button in Page Designer.
     • In the Security tab, assign the authorization scheme to restrict actions like submitting a form.
   • Items:
     • For form items or other page items, set the Authorization Scheme in the item’s Security tab to control access or editing rights.
   • Application-Level Settings:
     • To apply a scheme globally (e.g., to restrict the entire application), go to Shared Components > Security Attributes and set an authorization scheme under Application Authorization Scheme. This ensures all pages require the specified permission unless overridden.

4. Using Application Access Control for Role-Based Authorization
   Oracle APEX’s Application Access Control simplifies attaching role-based schemes:

   • Navigate to Shared Components > Application Access Control.
   • Define roles (e.g., Administrator, Editor, Viewer) and map them to users via a table like:

     CREATE TABLE apex_access_control (
       username VARCHAR2(100),
       access_level VARCHAR2(50)
     );
     

   • Create an authorization scheme to check roles:

     SELECT 1
     FROM apex_access_control
     WHERE username = :APP_USER
     AND access_level = 'ADMIN';
     

   • Attach this scheme to relevant components as described above.

5. Combining Multiple Authorization Schemes
   For complex requirements, combine schemes:

   • In the component’s Security tab, use the Combine with Other Schemes option to enforce multiple conditions (e.g., "User is Admin AND in Department X").
   • Example PL/SQL expression for combined logic:

     RETURN :APP_USER IN (SELECT username FROM department_users WHERE dept_id = :P1_DEPT_ID)
       AND is_admin(:APP_USER);
     

6. Testing and Validating

   • Test the authorization scheme by logging in as users with different roles to confirm access restrictions work as expected.
   • Use APEX Debug Mode or query the APEX_ACTIVITY_LOG view to troubleshoot issues with scheme evaluations.
   • Verify that error messages are user-friendly and appear when access is denied.

Attaching an authorization scheme to an application helps enforce security by restricting user access based on defined conditions. By associating an authorization scheme with an application, you can control overall access and determine how security rules are applied throughout the application.

Steps to Attach an Authorization Scheme to an Application

1. Open Oracle APEX and navigate to the Workspace home page.

2. Click on App Builder to view the list of available applications.

3. Select the application where you want to apply the authorization scheme.

4. Click on Shared Components to access application-wide settings.

5. Locate the Security section and click on Security Attributes.

6. Scroll down to the Authorization section and choose an authorization scheme from the Authorization Scheme dropdown list.

7. Configure the Run on Public Pages setting: 

• On: The authorization scheme will be checked on public pages (pages that do not require authentication).

• Off: The authorization scheme will not be checked on public pages.

8. If you need to create a new authorization scheme, click Define Authorization Schemes and follow the setup process.

By completing these steps, the selected authorization scheme will be applied at the application level, ensuring that security rules are consistently enforced throughout the application.

Best Practices for Attaching Authorization Schemes in Oracle APEX

• Apply Least Privilege: Attach schemes that grant only the necessary permissions for each user role to minimize security risks.
• Use Descriptive Names: Name schemes clearly (e.g., "Manager_Only" or "Edit_Access") to reflect their purpose and simplify maintenance.
• Optimize Evaluation Frequency: Use "Once per Session" for static permissions to reduce database queries, or "Once per Page View" for dynamic conditions.
• Leverage Application Access Control: Centralize role management for consistent and scalable authorization across the application.
• Test Thoroughly: Validate schemes in a development environment with various user scenarios to ensure correct behavior before production deployment.
• Document Configurations: Maintain detailed documentation of each scheme, its logic, and the components it’s attached to for easier troubleshooting.
• Monitor Access Attempts: Enable Application Activity Logging in Shared Components > Security Attributes to track access attempts and review logs for suspicious activity.
• Combine with Database Security: Use database-level security (e.g., Virtual Private Database) alongside authorization schemes for comprehensive protection.

Oracle APEX Documentation
For detailed guidance on attaching and managing authorization schemes in Oracle APEX, refer to the official documentation:
Oracle APEX Authorization Schemes Documentation

Conclusion
Attaching authorization schemes to an Oracle APEX application enables developers to enforce precise access controls, ensuring that users can only interact with components they are authorized to access. By creating schemes in Shared Components, applying them to pages, regions, or buttons, and leveraging features like Application Access Control, you can build a secure and scalable application. Following best practices and consulting the Oracle APEX documentation will help you maintain a robust security framework and adapt to evolving requirements.