Access Control Lists - TarisMajor/5143-OpSystems GitHub Wiki

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Access Control Lists (ACLs) are a fundamental security feature used to manage and control access to resources in a computing environment. They provide a flexible and granular method of specifying permissions for individual users or groups, allowing or denying access to various system objects such as files, directories, or network resources.

Key Characteristics of ACLs

  1. Entry-Based Control: An ACL consists of multiple entries, each specifying a set of permissions for a user or group. These permissions determine what actions the user or group can perform on the object.
  2. Fine-Grained Permissions: ACLs offer fine-grained control over access rights, allowing specific permissions such as read, write, execute, delete, and modify to be granted or denied.
  3. Multiple Entries: A single ACL can contain multiple entries, each defining access rights for different users or groups. This allows for detailed and comprehensive access control.

Advantages of ACLs

  1. Granular Access Control: ACLs provide detailed control over who can access what resources and what actions they can perform, enhancing security.
  2. Flexibility: The ability to specify permissions for individual users or groups allows for flexible and customized access control policies.
  3. Security: By restricting access to resources based on user roles and permissions, ACLs help protect sensitive data and prevent unauthorized access.

Disadvantages of ACLs

  1. Complexity: Managing ACLs can become complex, especially in environments with a large number of users and resources. Keeping track of permissions and ensuring they are correctly configured can be challenging.
  2. Performance Overhead: Evaluating ACLs for every access request can introduce performance overhead, particularly in systems with many access control entries.
  3. Management Overhead: Regular updates and maintenance of ACLs are required to ensure they reflect the current access control policies and organizational changes.

Use Cases for ACLs

  1. File Systems: ACLs are widely used in file systems to control access to files and directories. They determine which users can read, write, or execute files.
  2. Network Security: ACLs are used in network devices such as routers and firewalls to control traffic and enforce security policies based on IP addresses, protocols, and ports.
  3. Application Security: Many applications use ACLs to manage user permissions and control access to different features or data within the application.
  4. Databases: ACLs are used in database management systems to control access to tables, views, and other database objects.

Sources for Further Reading