node-casbin

News: still worry about how to write the correct node-casbin policy? Casbin online editor is coming to help! Try it at: http://casbin.org/editor/

node-casbin is a powerful and efficient open-source access control library for Node.JS projects. It provides support for enforcing authorization based on various access control models.

Installation

npm install casbin --save

Get started

1. New a node-casbin enforcer with a model file and a policy file:

   const enforcer = await Enforcer.newEnforcer('path/to/model.conf', 'path/to/policy.csv');

Note: you can also initialize an enforcer with policy in DB instead of file, see Persistence section for details.

2. Add an enforcement hook into your code right before the access happens:

   const sub = 'alice'; // the user that wants to access a resource.
   const obj = 'data1'; // the resource that is going to be accessed.
   const act = 'read'; // the operation that the user performs on the resource.
   
   if (enforcer.enforce(sub, obj, act) == true) {
       // permit alice to read data1
   } else {
       // deny the request, show an error
   }

3. Besides the static policy file, node-casbin also provides API for permission management at run-time. For example, You can get all the roles assigned to a user as below:

   const roles = enforcer.getRoles('alice');

See Policy management APIs for more usage.

4. Please refer to the src/test package for more usage.

All the languages supported by node-casbin:

• Golang: Casbin (production-ready)
• Java: jCasbin (production-ready)
• Node.js: node-casbin (production-ready)
• PHP: PHP-Casbin (experimental)
• C++: xCasbin (WIP)

Table of contents

• Supported models
• How it works?
• Features
• Documentation
• Online editor
• Tutorials
• Policy management
• Policy persistence
• Role manager
• Examples
• Our adopters

Supported models

1. ACL (Access Control List)
2. ACL with superuser
3. ACL without users: especially useful for systems that don't have authentication or user log-ins.
4. ACL without resources: some scenarios may target for a type of resources instead of an individual resource by using permissions like write-article, read-log. It doesn't control the access to a specific article or log.
5. RBAC (Role-Based Access Control)
6. RBAC with resource roles: both users and resources can have roles (or groups) at the same time.
7. RBAC with domains/tenants: users can have different role sets for different domains/tenants.
8. ABAC (Attribute-Based Access Control): syntax sugar like resource.Owner can be used to get the attribute for a resource.
9. RESTful: supports paths like /res/*, /res/:id and HTTP methods like GET, POST, PUT, DELETE.
10. Deny-override: both allow and deny authorizations are supported, deny overrides the allow.
11. Priority: the policy rules can be prioritized like firewall rules.

How it works?

In node-casbin, an access control model is abstracted into a CONF file based on the PERM metamodel (Policy, Effect, Request, Matchers). So switching or upgrading the authorization mechanism for a project is just as simple as modifying a configuration. You can customize your own access control model by combining the available models. For example, you can get RBAC roles and ABAC attributes together inside one model and share one set of policy rules.

The most basic and simplest model in node-casbin is ACL. ACL's model CONF is:

# Request definition
[request_definition]
r = sub, obj, act

# Policy definition
[policy_definition]
p = sub, obj, act

# Policy effect
[policy_effect]
e = some(where (p.eft == allow))

# Matchers
[matchers]
m = r.sub == p.sub && r.obj == p.obj && r.act == p.act

An example policy for ACL model is like:

p, alice, data1, read
p, bob, data2, write

It means:

• alice can read data1
• bob can write data2

Features

What node-casbin does:

1. enforce the policy in the classic {subject, object, action} form or a customized form as you defined, both allow and deny authorizations are supported.
2. handle the storage of the access control model and its policy.
3. manage the role-user mappings and role-role mappings (aka role hierarchy in RBAC).
4. support built-in superuser like root or administrator. A superuser can do anything without explict permissions.
5. multiple built-in operators to support the rule matching. For example, keyMatch can map a resource key /foo/bar to the pattern /foo*.

What node-casbin does NOT do:

1. authentication (aka verify username and password when a user logs in)
2. manage the list of users or roles. I believe it's more convenient for the project itself to manage these entities. Users usually have their passwords, and node-casbin is not designed as a password container. However, node-casbin stores the user-role mapping for the RBAC scenario.

Documentation

For documentation, please see: Our Wiki

Online editor

You can also use the online editor (http://casbin.org/editor/) to write your node-casbin model and policy in your web browser. It provides functionality such as syntax highlighting and code completion, just like an IDE for a programming language.

Tutorials

• Basic Role-Based HTTP Authorization in Go with Casbin (or Chinese translation)
• Using Casbin with Beego: 1. Get started and test (in Chinese)
• Using Casbin with Beego: 2. Policy storage (in Chinese)
• Using Casbin with Beego: 3. Policy query (in Chinese)

Policy management

node-casbin provides two sets of APIs to manage permissions:

• Management API: the primitive API that provides full support for node-casbin policy management. See here for examples.
• RBAC API: a more friendly API for RBAC. This API is a subset of Management API. The RBAC users could use this API to simplify the code. See here for examples.

We also provide a web-based UI for model management and policy management:

Policy persistence

In node-casbin, the policy storage is implemented as an adapter (aka middleware for node-casbin). To keep light-weight, we don't put adapter code in the main library (except the default file adapter). A complete list of node-casbin adapters is provided as below. Any 3rd-party contribution on a new adapter is welcomed, please inform us and I will put it in this list:)

Adapter	Type	Author	Description
File Adapter (built-in)	File	node-casbin	Persistence for .CSV (Comma-Separated Values) files
Sequelize Adapter	ORM	Casbin	MySQL, PostgreSQL, SQLite, Microsoft SQL Server are supported by Sequelize

For details of adapters, please refer to the documentation: https://github.com/casbin/casbin/wiki/Policy-persistence

Role manager

The role manager is used to manage the RBAC role hierarchy (user-role mapping) in node-casbin. A role manager can retrieve the role data from node-casbin policy rules or external sources such as LDAP, Okta, Auth0, Azure AD, etc. We support different implementations of a role manager. To keep light-weight, we don't put role manager code in the main library (except the default role manager). A complete list of node-casbin role managers is provided as below. Any 3rd-party contribution on a new role manager is welcomed, please inform us and I will put it in this list:)

Role manager	Author	Description
Default Role Manager (built-in)	node-casbin	Supports role hierarchy stored in node-casbin policy

For developers: all role managers must implement the RoleManager interface. Default Role Manager can be used as a reference implementation.

Examples

Model	Model file	Policy file
ACL	basic_model.conf	basic_policy.csv
ACL with superuser	basic_model_with_root.conf	basic_policy.csv
ACL without users	basic_model_without_users.conf	basic_policy_without_users.csv
ACL without resources	basic_model_without_resources.conf	basic_policy_without_resources.csv
RBAC	rbac_model.conf	rbac_policy.csv
RBAC with resource roles	rbac_model_with_resource_roles.conf	rbac_policy_with_resource_roles.csv
RBAC with domains/tenants	rbac_model_with_domains.conf	rbac_policy_with_domains.csv
ABAC	abac_model.conf	N/A
RESTful	keymatch_model.conf	keymatch_policy.csv
Deny-override	rbac_model_with_deny.conf	rbac_policy_with_deny.csv
Priority	priority_model.conf	priority_policy.csv

Our adopters

Web frameworks

• Express: Fast, unopinionated, minimalist web framework for node, via plugin: express-authz
• Koa: Expressive middleware for node.js using ES2017 async functions, via plugin: koa-authz
• Egg: Born to build better enterprise frameworks and apps with Node.js & Koa , via plugin: egg-authz

License

This project is licensed under the Apache 2.0 license.

Contact

If you have any issues or feature requests, please contact us. PR is welcomed.

• https://github.com/casbin/node-casbin/issues
• [email protected]
• Tencent QQ group: 546057381