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News: 🔥 How to use it withDjango ? TryDjango Authorization, an authorization library forDjango framework.

News: Async is now supported by Pycasbin >= 1.23.0!

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

Casbin is a powerful and efficient open-source access control library for Python projects. It provides support for enforcing authorization based on variousaccess control models.

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

PyCasbin	Casbin.NET	Casbin-CPP	Casbin-RS
production-ready	production-ready	beta-test	production-ready

• Supported models
• How it works?
• Features
• Installation
• Documentation
• Online editor
• Tutorials
• Get started
• Policy management
• Policy persistence
• Role manager
• Async Enforcer
• Benchmarks
• Logging
• Examples
• Middlewares
• Our adopters

1. ACL (Access Control List)
2. ACL withsuperuser
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 likewrite-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 likeresource.Owner can be used to get the attribute for a resource.
9. RESTful: supports paths like/res/*,/res/:id and HTTP methods likeGET,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.

In Casbin, an access control model is abstracted into a CONF file based on thePERM 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 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, readp, bob, data2, write

It means:

• alice can read data1
• bob can write data2

We also support multi-line mode by appending '\' in the end:

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

Further more, if you are using ABAC, you can try operatorin like following in Casbingolang edition (jCasbin and Node-Casbin are not supported yet):

# Matchers[matchers]m =r.obj == p.obj &&r.act == p.act || r.obj in ('data2','data3')

But youSHOULD make sure that the length of the array isMORE than1, otherwise there will cause it to panic.

For more operators, you may take a look atgovaluate

What 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 likeroot oradministrator. 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 Casbin does NOT do:

1. authentication (aka verifyusername andpassword 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 Casbin is not designed as a password container. However, Casbin stores the user-role mapping for the RBAC scenario.

pip install pycasbin

https://casbin.org/docs/overview

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

https://casbin.org/docs/tutorials

1. New a Casbin enforcer with a model file and a policy file:

importcasbine=casbin.Enforcer("path/to/model.conf","path/to/policy.csv")

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

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

sub="alice"# the user that wants to access a resource.obj="data1"# the resource that is going to be accessed.act="read"# the operation that the user performs on the resource.ife.enforce(sub,obj,act):# permit alice to read data1passelse:# deny the request, show an errorpass

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

roles=e.get_roles_for_user("alice")

SeePolicy management APIs for more usage.

4. Please refer to thetests files for more usage.

Casbin provides two sets of APIs to manage permissions:

• Management API: the primitive API that provides full support for Casbin policy management. Seehere 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. Seehere for examples.

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

https://casbin.org/docs/adapters

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

If your code useasync /await and is heavily dependent on I/O operations, you can adopt Async Enforcer!

1. Create an async engine and new a Casbin AsyncEnforcer with a model file and an async Pycasbin adapter (AsyncAdapter subclass):

importasyncioimportosimportcasbinfromsqlalchemy.ext.asyncioimportcreate_async_engine,AsyncSessionfromsqlalchemy.ormimportsessionmakerfromcasbin_async_sqlalchemy_adapterimportAdapter,CasbinRuleasyncdefget_enforcer():engine=create_async_engine("sqlite+aiosqlite://",future=True)adapter=Adapter(engine)awaitadapter.create_table()async_session=sessionmaker(engine,expire_on_commit=False,class_=AsyncSession)asyncwithasync_session()ass:s.add(CasbinRule(ptype="p",v0="alice",v1="data1",v2="read"))s.add(CasbinRule(ptype="p",v0="bob",v1="data2",v2="write"))s.add(CasbinRule(ptype="p",v0="data2_admin",v1="data2",v2="read"))s.add(CasbinRule(ptype="p",v0="data2_admin",v1="data2",v2="write"))s.add(CasbinRule(ptype="g",v0="alice",v1="data2_admin"))awaits.commit()e=casbin.AsyncEnforcer("path/to/model.conf",adapter)awaite.load_policy()returne

Note: you can see all supported adapters inAdapters | Casbin.

Built-in async adapters are available incasbin.persist.adapters.asyncio.

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

asyncdefmain():e=awaitget_enforcer()ife.enforce("alice","data1","read"):print("alice can read data1")else:print("alice can not read data1")

3. Run the code:

asyncio.run(main())

4. Please refer to thetests files for more usage.

https://casbin.org/docs/benchmark

pycasbin leverages the default Python logging mechanism. The pycasbin package makes a call tologging.getLogger() to set the logger. No special logging configuration is needed other than initializing the logger in the parent application. If no logging is initialized within the parent application, you will not see any log messages from pycasbin. At the same time, When you enable log in pycasbin, you can specify the logging configuration through the parameterlogging_config. If no configuration is specified, it will use thedefault log configuration. For other pycasbin extensions, you can refer to theDjango logging docs if you are a Django user. For other Python users, you should refer to thePython logging docs to configure the logger.

Authz middlewares for web frameworks:https://casbin.org/docs/middlewares

https://casbin.org/docs/adopters

This project exists thanks to all the people who contribute.

Thank you to all our backers! 🙏 [Become a backer]

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This project is licensed under theApache 2.0 license.

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

• https://github.com/casbin/pycasbin/issues
• https://discord.gg/S5UjpzGZjN