Rhebok - A hierarchical, asynchronous role based access control (RBAC) module
Overview
This module works by defining a hierarchy of roles and capabilities and checking to see if a role possesses a certain capability. This allows you to determine whether a user should have access to a given resource or operation. The module is written in Typescript and compiles to commonjs.
This module is in beta. The API could change prior to 1.0 release.
Changelog
- 0.2.0: Instead of extending the
Cap
class, you should now create a class that implementsICap
. See the example.spec.ts file for implementation details.
Install
npm install rhebok
Sample Code
Code samples demonstrating the usage of this module are available here.
Objects
Role
Accepts name and params.
Important
The Role name must be unique within your role hierarchy. To ensure that you haven't used a role name twice, you can chain the validate()
method to the end of your topmost role. This will run a recursive check and throw an error if a duplicate role name has been found. While you do not have to call this method, keep in mind that accidentally re-using a role name could result in a user gaining elevated access.
const SimpleRoleSchema = new Role(
'logged-out',
{
caps: [
new HasCap('user:create')
],
children: [
new Role(
'logged-in',
{
caps: [
new HasCap('event:create'),
new ConditionalCap(
'event:update',
{
if: async (context: any) => {
return (context.eventOwnerId === context.userId);
}
}
)
]
}
)
]
}
).validate();
Methods
Can
Accepts a role name, capability name and a context object. The context object is passed into any ConditionalCap
to help it decide if the role should pass the capability check. This method returns a promise which resolves to true if the role has the capability.
SimpleRoleSchema.can(
'logged-in',
'event:update',
{
userId: 5,
eventOwnerId: 6
}
);
HasCap
Accepts name. If a role has this capability then the role is deemed to be authorized.
new HasCap('event:create')
ConditionalCap
Accepts a name and params. If a role has this capability, then the function assigned to the if
attribute of params is called. The if
function should return a promise. If that promise resolves with true, then the role is deemed authorized.
new ConditionalCap(
'event:update',
{
if: async (context: any) => {
return (context.eventOwnerId === context.userId);
}
}
)
Extending Roles and Capabilities
Extending Roles
You may wish to extend the Role object in your application with a thin wrapper. This will provide two benefits:
- You can use types for your roles and the context parameter which gives you the benefits of type checking in Typescript.
- You can encapsulate logic for asynchronously retrieving a users role. This is especially helpful when the users role depends on the authorization context (i.e. the users role depends on the particular object they are trying to access).
The examples folder shows how to extend roles and capabilities with custom typings.