Role Based Access Control

This page outlines the architecture and design principles of the Permit Connect Navigator Service (PCNS) role based access control (RBAC) system.

Table of Contents

• Database schema
• Group
• Role
• Policy
• Resource
• Action
• Attribute
• Database
• Implementation

Database schema

Audit columns removed from image for readability

Group

Users can belong to one or many groups. A group is associated with a specific initiative. A group is defined by its associated roles, which further dictate the exact policies & permission sets a user may have. User are tracked by their SSO identity ID, and user to group associations are kept in the identity_group table.

Role

Roles are defined by a unique name. Roles are a collection of zero to many policies.

Policy

A policy is a unique set of an Action and a Resource. This defines a specific permission that will be granted to a user in the application. Policies may have additional modifiers, called Attributes, which further define how a resource is acted upon.

Resource

A Resource is a collection of data. These are typically defined by existing API routes and database tables, but could be extended to anything, including front end application concerns.

Examples: Submission & Permit

Action

An Action is an allowable action within the application. These are typically defined by existing API methods, but could be extended to anything, including front end application concerns.

Examples: Create & Read

Attribute

An attribute is an optional modifier for a policy. They can apply globally to all groups, or act specifically against a group. These are simply strings that the application will have to take into account accordingly. The primary use of an attribute is defining the scope of a resource a group can access (eg: only access resources created by current user vs access to all resources), but they could be used for just about anything.

Database

New tables

group
PK	group_id: int
FK	initiative_id: uuid
	name : text
	description : text
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	group_id, initiative_id

role
PK	role_id: int
	name: text
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	name

policy
PK	policy_id: int
FK	resource_id: int
FK	action_id: int
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp

resource
PK	resource_id: int
	name: text
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	name

action
PK	action_id: int
	name: text
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	name

attribute
PK	attribute_id: int
	name: text
	description: text
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	name

subject_group
FK	sub: int
FK	group_id: int
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	sub, group_id

group_role
FK	group_id: int
FK	role_id: int
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	group_id, role_id

role_policy
FK	role_id: int
FK	policy_id: int
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	role_id, policy_id

policy_attribute
FK	policy_id: int
FK	attribute_id: int
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	policy_id, attribute_id

attribute_group
FK	attribute_id: int
FK	group_id: int
	created_by: text
	created_at: timestamp
	updated_by: text
	updated_at: timestamp
UNIQUE	attribute_id, group_id

Implementation

Backend

1. Middleware

   1. Three new middlewares will be created: requireSomeGroup, hasAuthorization, and hasAccess.
   2. requireSomeGroup takes zero parameters. It's sole responsibility is to check if a user is currently assigned to any groups. If not, it will attempt to assign the default group.
   3. hasAuthorization will take two parameters, resource and action. The middleware has 2 primary responsibilities
      1. To ensure the requesting user has a policy set matching the requested parameters
      2. Inject the attributes associated to any matching policies into the request
   4. hasAccess will take one parameter, being a route parameter of some kind (eg: submissionId). The middleware has 1 responsibility
      1. To check if the attributes injected in hasAuthorization contain resource access scoping. If so then this middleware will ensure that the requesting user is allowed to access the resource in question.

2. Controller layer

   1. Unfortunately there is no straight forward approach to handling attributes. Developers will have to be cognizant of which routes may or may not require attributes.

3. Service layer

   1. Any service calls that may require resource scoping should be passed the scope from the controller.
   2. This scope should then be used to determine the correct database query to be used on the resource.
   3. Appropriate response will be returned to the controller.

4. New endpoints

   1. /permissions
      • Authenticated endpoint
      • Returns a list of permissions for the authenticated user

Frontend

1. authzStore
   1. A new store to be created. This will store the full list of user permissions obtained from the new /permissions endpoint, as well as front end navigation permission
   2. Provides a computed getter function to check if a user has the requested permission
      • can: computed(() => (initiative: Initiative, resource: Resource, action: Action, group?: GroupName) =>
2. Log in
   1. Upon a user logging in, an api call should be made to the new /permissions endpoint to obtain the appropriate front end permission set
   2. This result will be stored in the new authzStore
3. Checking permissions
   1. Using the authzStore, you can check if a user has the necessary permission via authzStore.can(initiative, resource, action, group?: GroupName)
4. Updating permissions
   1. At this time we are not concerned about real time permission updates
   2. We could potentially query the /permissions endpoint on token refresh and store the new set in the authzStore. Any changes should then propagate automatically via the computed function.

Dealing with the developer role

The developer role will not be included in the database permission table. Instead the front and back end authorization checks will check the users groups for the developer role. If present the action will automatically be allowed.