| src/flask_digest_auth | ||
| tests | ||
| .gitignore | ||
| LICENSE | ||
| MANIFEST.in | ||
| pyproject.toml | ||
| README.rst | ||
| setup.cfg | ||
Flask HTTP Digest Authentication
Description
Flask-Digest-Auth is an HTTP Digest Authentication implementation for Flask applications. It authenticates the user for the protected views.
HTTP Digest Authentication is specified in RFC 2617.
Why HTTP Digest Authentication?
HTTP Digest Authentication has the advantage that it does not send the actual password to the server, which greatly enhances the security. It uses the challenge-response authentication scheme. The client returns the response calculated from the challenge and the password, but not the original password.
Log in forms has the advantage of freedom, in the senses of both the visual design and the actual implementation. You may implement your own challenge-response log in form, but then you are reinventing the wheels. If a pretty log in form is not critical to your project, HTTP Digest Authentication should be a good choice.
Flask-Digest-Auth works with Flask-Login. Log in protection can be separated with the authentication mechanism. You can create protected Flask modules without knowing the actual authentication mechanisms.
Features
There are a couple of Flask HTTP digest authentication implementations. Flask-Digest-Auth has the following features:
Flask-Login Integration
Flask-Digest-Auth features Flask-Login integration. The views can be totally independent with the actual authentication mechanism. You can write a Flask module that requires log in, without specify the actual authentication mechanism. The application can specify either HTTP Digest Authentication, or the log in forms, as needed.
Session Integration
Flask-Digest-Auth features session integration. The user log in is remembered in the session. The authentication information is not requested again. This is different to the practice of the HTTP Digest Authentication, but is convenient for the log in accounting.
Log Out Support
Flask-Digest-Auth supports log out. The user will be prompted for new username and password.
Log In Bookkeeping
You can register a callback to run when the user logs in.
Installation
You can install Flask-Digest-Auth with pip:
pip install Flask-Digest-Auth
You may also install the latest source from the Flask-Digest-Auth GitHub repository.
git clone git@github.com:imacat/flask-digest-auth.git cd flask-digest-auth pip install .
Flask-Digest-Auth Alone
Flask-Digest-Auth can authenticate the users alone.
The currently logged-in user can be retrieved at g.user, if any.
Example for Simple Applications with Flask-Digest-Auth Alone
In your my_app.py:
from flask import Flask, request, redirect
from flask_digest_auth import DigestAuth
app: flask = Flask(__name__)
... (Configure the Flask application) ...
auth: DigestAuth = DigestAuth(realm="Admin")
auth.init_app(app)
@auth.register_get_password
def get_password_hash(username: str) -> t.Optional[str]:
... (Load the password hash) ...
@auth.register_get_user
def get_user(username: str) -> t.Optional[t.Any]:
... (Load the user) ...
@app.get("/admin")
@auth.login_required
def admin():
return f"Hello, {g.user.username}!"
@app.post("/logout")
@auth.login_required
def logout():
auth.logout()
return redirect(request.form.get("next"))
Example for Larger Applications with create_app() with Flask-Digest-Auth Alone
In your my_app/__init__.py:
from flask import Flask
from flask_digest_auth import DigestAuth
auth: DigestAuth = DigestAuth()
def create_app(test_config = None) -> Flask:
app: flask = Flask(__name__)
... (Configure the Flask application) ...
auth.realm = app.config["REALM"]
auth.init_app(app)
@auth.register_get_password
def get_password_hash(username: str) -> t.Optional[str]:
... (Load the password hash) ...
@auth.register_get_user
def get_user(username: str) -> t.Optional[t.Any]:
... (Load the user) ...
return app
In your my_app/views.py:
from my_app import auth
from flask import Flask, Blueprint, request, redirect
bp = Blueprint("admin", __name__, url_prefix="/admin")
@bp.get("/admin")
@auth.login_required
def admin():
return f"Hello, {g.user.username}!"
@app.post("/logout")
@auth.login_required
def logout():
auth.logout()
return redirect(request.form.get("next"))
def init_app(app: Flask) -> None:
app.register_blueprint(bp)
Flask-Login Integration
Flask-Digest-Auth can work with Flask-Login. You can write a Flask module that requires log in, without specifying the authentication mechanism. The Flask application can specify the actual authentication mechanism as it sees fit.
login_manager.init_app(app) must be called before auth.init_app(app).
The currently logged-in user can be retrieved at flask_login.current_user, if any.
Example for Simple Applications with Flask-Login Integration
In your my_app.py:
import flask_login
from flask import Flask, request, redirect
from flask_digest_auth import DigestAuth
app: flask = Flask(__name__)
... (Configure the Flask application) ...
login_manager: flask_login.LoginManager = flask_login.LoginManager()
login_manager.init_app(app)
@login_manager.user_loader
def load_user(user_id: str) -> t.Optional[User]:
... (Load the user with the username) ...
auth: DigestAuth = DigestAuth(realm="Admin")
auth.init_app(app)
@auth.register_get_password
def get_password_hash(username: str) -> t.Optional[str]:
... (Load the password hash) ...
@app.get("/admin")
@flask_login.login_required
def admin():
return f"Hello, {flask_login.current_user.get_id()}!"
@app.post("/logout")
@flask_login.login_required
def logout():
auth.logout()
# Do not call flask_login.logout_user()
return redirect(request.form.get("next"))
Example for Larger Applications with create_app() with Flask-Login Integration
In your my_app/__init__.py:
from flask import Flask
from flask_digest_auth import DigestAuth
from flask_login import LoginManager
auth: DigestAuth = DigestAuth()
def create_app(test_config = None) -> Flask:
app: flask = Flask(__name__)
... (Configure the Flask application) ...
login_manager: LoginManager = LoginManager()
login_manager.init_app(app)
@login_manager.user_loader
def load_user(user_id: str) -> t.Optional[User]:
... (Load the user with the username) ...
auth.realm = app.config["REALM"]
auth.init_app(app)
@auth.register_get_password
def get_password_hash(username: str) -> t.Optional[str]:
... (Load the password hash) ...
return app
In your my_app/views.py:
import flask_login
from flask import Flask, Blueprint, request, redirect
from my_app import auth
bp = Blueprint("admin", __name__, url_prefix="/admin")
@bp.get("/admin")
@flask_login.login_required
def admin():
return f"Hello, {flask_login.current_user.get_id()}!"
@app.post("/logout")
@flask_login.login_required
def logout():
auth.logout()
# Do not call flask_login.logout_user()
return redirect(request.form.get("next"))
def init_app(app: Flask) -> None:
app.register_blueprint(bp)
The views only depend on Flask-Login, but not the actual authentication mechanism. You can change the actual authentication mechanism without changing the views.
Setting the Password Hash
The password hash of the HTTP Digest Authentication is composed of the realm, the username, and the password. Example for setting the password:
from flask_digest_auth import make_password_hash user.password = make_password_hash(realm, username, password)
The username is part of the hash. If the user changes their username, you need to ask their password, to generate and store the new password hash.
Log Out
Call auth.logout() when the user wants to log out. Besides the usual log out routine, auth.logout() actually causes the next browser automatic authentication to fail, forcing the browser to ask the user for the username and password again.
Log In Bookkeeping
You can register a callback to run when the user logs in, for ex., logging the log in event, adding the log in counter, etc.
@auth.register_on_login
def on_login(user: User) -> None:
user.visits = user.visits + 1
Writing Tests
You can write tests with our test client that handles HTTP Digest Authentication. Example for a unittest testcase:
from flask_digest_auth import Client
from flask_testing import TestCase
from my_app import create_app
class MyTestCase(TestCase):
def create_app(self):
app: Flask = create_app({
"SECRET_KEY": token_urlsafe(32),
"TESTING": True
})
app.test_client_class = Client
return app
def test_admin(self):
response = self.client.get("/admin")
self.assertEqual(response.status_code, 401)
response = self.client.get(
"/admin", digest_auth=("my_name", "my_pass"))
self.assertEqual(response.status_code, 200)
Copyright
Copyright (c) 2022 imacat.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.