Metadata-Version: 2.1
Name: starlette-auth-toolkit
Version: 0.4.0
Summary: Authentication backends and helpers for Starlette-based apps and frameworks
Home-page: https://github.com/florimondmanca/starlette-auth-toolkit.git
Author: Florimond Manca
Author-email: florimond.manca@gmail.com
License: License :: OSI Approved :: MIT License
Description: # starlette-auth-toolkit
        
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        Authentication backends and helpers for Starlette-based apps and frameworks.
        
        > **Note**: documentation is in progress. In the meantime, feel free to [read the source code](https://github.com/florimondmanca/starlette-auth-toolkit/tree/master/starlette_auth_toolkit).
        
        **Features**
        
        - Database-agnostic.
        - User model-agnostic.
        - Built-in password hashing powered by [PassLib].
        - Hash migration support.
        - Built-in support for common authentication flows, including Basic and Bearer authentication.
        - Support for multiple authentication backends.
        - Easy integration with [`orm`].
        
        [passlib]: https://passlib.readthedocs.io/en/stable/index.html
        [`orm`]: https://github.com/encode/orm
        
        **Contents**
        
        - [Installation](#installation)
        - [Quickstart](#quickstart)
        - [Base backends](#base-backends)
        - [Password hashers](#password-hashers)
        - [Authentication helpers](#authentication-helpers)
        
        ## Installation
        
        ```bash
        pip install starlette-auth-toolkit
        ```
        
        ## Quickstart
        
        ```python
        import typing
        
        from starlette.applications import Starlette
        from starlette.authentication import requires
        from starlette.middleware.authentication import AuthenticationMiddleware
        from starlette.responses import JSONResponse
        
        from starlette_auth_toolkit.base.backends import BasicAuthBackend
        from starlette_auth_toolkit.base.helpers import BaseAuthenticate
        from starlette_auth_toolkit.cryptography import PBKDF2Hasher
        
        
        # User model
        
        class User(typing.NamedTuple):
            username: str
            password: str
        
        
        # Password hasher
        
        hasher = PBKDF2Hasher()
        
        
        # Fake storage
        
        USERS = {
            "alice": User(username="alice", password=hasher.make_sync("alicepwd")),
            "bob": User(username="bob", password=hasher.make_sync("bobpwd")),
        }
        
        
        # Authentication helper
        
        class Authenticate(BaseAuthenticate):
            async def find_user(self, username: str):
                return USERS.get(username)
        
            async def verify_password(self, user: User, password: str):
                return await hasher.verify(password, user.password)
        
        
        authenticate = Authenticate()
        
        
        # Authentication backend
        
        class BasicAuth(BasicAuthBackend):
            async def verify(
                self, username: str, password: str
            ) -> typing.Optional[User]:
                return await authenticate(username, password)
        
        
        # Application
        
        app = Starlette()
        app.add_middleware(AuthenticationMiddleware, backend=BasicAuth())
        
        
        @app.route("/")
        @requires("authenticated")
        async def home(request):
            """Example protected route."""
            return JSONResponse({"message": f"Hello, {request.user.username}!"})
        
        ```
        
        Save this file as `app.py`. Then, assuming you have [uvicorn](https://www.uvicorn.org/) installed, run `$ uvicorn app:app` and make requests:
        
        - Anonymous request:
        
        ```bash
        curl http://localhost:8000 -i
        ```
        
        ```http
        HTTP/1.1 401 Unauthorized
        date: Sun, 21 Jul 2019 17:54:00 GMT
        server: uvicorn
        content-length: 52
        content-type: text/plain; charset=utf-8
        
        Could not authenticate with the provided credentials
        ```
        
        - Authenticated request:
        
        ```bash
        curl -u alice:alicepwd http://localhost:8000
        ```
        
        ```http
        HTTP/1.1 200 OK
        date: Sun, 21 Jul 2019 17:54:28 GMT
        server: uvicorn
        content-length: 27
        content-type: application/json
        
        {"message":"Hello, alice!"}
        ```
        
        For a real-world example, [see here](https://github.com/florimondmanca/starlette-auth-toolkit/blob/master/tests/apps/example.py).
        
        ## Base backends
        
        Base backends implement an **authentication flow**, but the exact implementation of credentials verification is left up to you. This means you can choose to perform a database query, use environment variables or private files, etc.
        
        These backends grant a set of [scopes](https://www.starlette.io/authentication/#authcredentials) when authentication succeeds.
        
        Although base backends are **user model agnostic**, we recommend you implement the interface specified by `starlette.authentication.BaseUser` (see also [Starlette authentication](https://www.starlette.io/authentication/)).
        
        They are available at `starlette_auth_toolkit.base.backends`.
        
        ### `BasicAuthBackend`
        
        Implementation of the [Basic authentication scheme](https://tools.ietf.org/html/rfc7617).
        
        **Request header format**
        
        ```http
        Authorization: Basic {credentials}
        ```
        
        where `{credentials}` refers to the base64 encoding of `{username}:{password}`.
        
        **Example**
        
        ```python
        # myapp/auth.py
        from starlette.authentication import SimpleUser  # or a custom user model
        from starlette_auth_toolkit.base import backends
        
        class BasicAuthBackend(backends.BasicAuthBackend):
            async def verify(self, username: str, password: str):
                # In practice, request the database to find the user associated
                # to `username`, and validate that its password hash matches the
                # given password.
                if (username, password) != ("bob", "s3kr3t"):
                    return None
                return SimpleUser(username)
        ```
        
        **Abstract methods**
        
        - _async_ `.verify(self, username: str, password: str) -> Optional[BaseUser]`
        
          If `username` and `password` are valid, return the corresponding user. Otherwise, return `None`.
        
        **Scopes**
        
        - `authenticated`
        
        ### `BearerAuthBackend`
        
        Implementation of the [Bearer authentication scheme](https://tools.ietf.org/html/rfc6750), also known as _Token authentication_.
        
        **Request header format**
        
        ```http
        Authorization: Bearer {token}
        ```
        
        **Example**
        
        ```python
        # myapp/auth.py
        from starlette.authentication import SimpleUser  # or a custom user model
        from starlette_auth_toolkit.base import backends
        
        class BearerAuthBackend(backends.BearerAuthBackend):
            async def verify(self, token: str):
                # In practice, request the database to find the token object
                # associated to `token`, and return its associated user.
                if token != "abcd":
                    return None
                return SimpleUser("bob")
        ```
        
        **Abstract methods**
        
        - _async_ `.verify(self, token: str) -> Optional[BaseUser]`
        
          If `token` refers to a valid token, return the corresponding user. Otherwise, return `None`.
        
        **Scopes**
        
        - `authenticated`
        
        ## Password hashers
        
        This package provides password hashing utilities built on top of [PassLib].
        
        ### Usage
        
        - Asynchronous: `await .make()` / `await .verify()` (hashing and verification occurs in the threadpool)
        
        ```python
        import asyncio
        from starlette_auth_toolkit.cryptography import PBKDF2Hasher
        
        async def main():
            # Instanciate a hasher:
            hasher = PBKDF2Hasher()
        
            # Hash a password:
            pwd = await hasher.make("hello")
        
            # Verify a password against a known hash:
            assert await hasher.verify("hello", pwd)
        
        # Python 3.7+
        asyncio.run(main())
        ```
        
        - Blocking: `.make_sync()` / `.verify_sync()`
        
        ```python
        from starlette_auth_toolkit.cryptography import PBKDF2Hasher
        
        # Instanciate a hasher:
        hasher = PBKDF2Hasher()
        
        # Hash a password
        pwd = hasher.make_sync("hello")
        
        # Verify a password against a known hash:
        assert hasher.verify_sync("hello", pwd)
        ```
        
        ### Hash migration (Advanced)
        
        If you need to change the hash algorithm (say from PBKDF2 to Argon2), you will typically want to keep support for existing hashes, but rehash them with the new algorithm as soon as possible.
        
        `MultiHasher` was designed to solve this problem:
        
        ```python
        from starlette_auth_toolkit.cryptography import Argon2Hasher, PBKDF2Hasher, MultiHasher
        
        hasher = MultiHasher([Argon2Hasher(), PBKDF2Hasher()])
        ```
        
        The above `hasher` will use Argon2 when hashing new passwords, but will be able to verify hashes created using either Argon2 or PBKDF2.
        
        To detect whether a hash needs rehashing, use `.needs_update()`:
        
        ```python
        valid = await hasher.verify(pwd, pwd_hash)
        
        if hasher.needs_update(pwd_hash):
            new_hash = await hasher.make(pwd)
            # TODO: store new hash
        
        # ...
        ```
        
        > **Note**: calling `.needs_update()` at anytime other than just after calling `.verify()` will raise a `RuntimeError`.
        
        ### Available hashers
        
        | Name           | Requires      | PassLib algorithm |
        | -------------- | ------------- | ----------------- |
        | `PBKDF2Hasher` |               | `pbkdf2_sha256`   |
        | `CryptHasher`  |               | `sha256_crypt`    |
        | `BCryptHasher` | `bcrypt`      | `bcrypt`          |
        | `Argon2Hasher` | `argon2-cffi` | `argon2`          |
        | `MultiHasher`  |               | N/A               |
        
        For advanced use cases, use `Hasher` and pass one of the algorithms listed in [passlib.hash](https://passlib.readthedocs.io/en/stable/lib/passlib.hash.html):
        
        ```python
        from starlette_auth_toolkit.cryptography import Hasher
        
        hasher = Hasher(algorithm="pbkdf2_sha512")
        ```
        
        ## Authentication helpers
        
        Web applications often need to exchange user credentials (username and password) against the actual user.
        
        Such an exchange is typically implemented as an `authenticate` utility function:
        
        ```python
        user = await authenticate(username, password)
        ```
        
        Helpers listed here make it easier to build a secure `authenticate` utility function, which you can then reuse when building your authentication backends.
        
        ### `base.helpers.BaseAuthenticate`
        
        Base class for authentication helpers.
        
        **Abstract methods**
        
        - _async_ `.find_user(self, username: str) -> Optional[BaseUser]`
        
          Return the user associated to `username`, or `None` if none exist.
        
        - _async_ `.verify_password(self, user: BaseUser, password: str) -> bool`
        
          Given a user, check that the given `password` is valid.
          For example, compare the given `password` against the user's password hash.
        
        **Methods**
        
        - _async_ `.__call__(self, username: str, password: str) -> Optional[BaseUser]`
        
          Authenticate a user using the following algorithm:
        
          1. Find a `user` using `.find_user()`
          2. Verify the password using `.verify_password()`
          3. Return `user` if it exists and the password is valid, and `None` otherwise.
        
        ### `contrib.orm.ModelAuthenticate`
        
        A ready-to-use implementation of `BaseAuthenticate` using an `orm` user model.
        
        **Note**: [`orm`] must be installed to use this helper.
        
        **Example**
        
        ```python
        from starlette.applications import Starlette
        from starlette_auth_toolkit.contrib.orm import ModelAuthenticate
        from starlette_auth_toolkit.cryptography import PBKDF2Hasher
        
        from myproject.models import User  # DIY
        
        hasher = PBKDF2Hasher()
        authenticate = ModelAuthenticate(User, hasher=hasher)
        
        app = Starlette()
        
        @app.route("/")
        async def home(request):
            data = await request.json()
            username, password = data["username"], data["password"]
            user: User = await authenticate(username, password)
            # ...
        ```
        
        **Parameters**
        
        - `model` (`orm.Model` or `() -> orm.Model`): the user model (or a callable for lazy loading).
        - `hasher` (`BaseHasher`): a [password hasher](#password-hashers) — the same one used to hash user passwords.
        - `password_field` (`str`, optional): field where password hashes are stored on user objects. Defaults to `"password"`.
        
        ## Contributing
        
        Want to contribute? Awesome! Be sure to read our [Contributing guidelines](https://github.com/florimondmanca/starlette-auth-toolkit/tree/master/CONTRIBUTING.md).
        
        ## Changelog
        
        See [CHANGELOG.md](https://github.com/florimondmanca/starlette-auth-toolkit/tree/master/CHANGELOG.md).
        
        ## License
        
        MIT
        
Platform: UNKNOWN
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Operating System :: OS Independent
Requires-Python: >=3.6
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Provides-Extra: dev
