jCasbin

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

jCasbin is a powerful and efficient open-source access control library for Java projects. It provides support for enforcing authorization based on various access control models.

All the languages supported by Casbin:


Casbin	jCasbin	node-Casbin	PHP-Casbin
production-ready	production-ready	production-ready	production-ready


PyCasbin	Casbin.NET	Casbin4D	Casbin-RS
production-ready	production-ready	experimental	WIP

Supported models
How it works?
Features
Installation
Documentation
Online editor
Tutorials
Get started
Policy management
Policy persistence
Role manager
Examples
Middlewares
Our adopters
Spring Boot support

Supported models

ACL (Access Control List)
ACL with superuser
ACL without users: especially useful for systems that don't have authentication or user log-ins.
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.
RBAC (Role-Based Access Control)
RBAC with resource roles: both users and resources can have roles (or groups) at the same time.
RBAC with domains/tenants: users can have different role sets for different domains/tenants.
ABAC (Attribute-Based Access Control): syntax sugar like resource.Owner can be used to get the attribute for a resource.
RESTful: supports paths like /res/*, /res/:id and HTTP methods like GET, POST, PUT, DELETE.
Deny-override: both allow and deny authorizations are supported, deny overrides the allow.
Priority: the policy rules can be prioritized like firewall rules.

How it works?

In jCasbin, 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 jCasbin 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 jCasbin does:

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

What jCasbin does NOT do:

authentication (aka verify username and password when a user logs in)
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 jCasbin is not designed as a password container. However, jCasbin stores the user-role mapping for the RBAC scenario.

Installation

For Maven:

<dependency>
  <groupId>org.casbin</groupId>
  <artifactId>jcasbin</artifactId>
  <version>1.4.0</version>
</dependency>

Documentation

https://casbin.org/docs/en/overview

Online editor

You can also use the online editor (http://casbin.org/editor/) to write your jCasbin 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

https://casbin.org/docs/en/tutorials

Get started

New a jCasbin enforcer with a model file and a policy file:

Enforcer enforcer = new Enforcer("path/to/model.conf", "path/to/policy.csv");

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

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

String sub = "alice"; // the user that wants to access a resource.
String obj = "data1"; // the resource that is going to be accessed.
String 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
}

Besides the static policy file, jCasbin also provides API for permission management at run-time. For example, You can get all the roles assigned to a user as below:
```
Roles roles = enforcer.getRoles("alice");
```

See Policy management APIs for more usage.

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

Policy management

jCasbin provides two sets of APIs to manage permissions:

Management API: the primitive API that provides full support for jCasbin 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

https://casbin.org/docs/en/adapters

Role manager

https://casbin.org/docs/en/role-managers

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