Advanced to version 0.2.3.

.gitignore

@@ -23,10 +23,13 @@ dist
 .pytest_cache
 venv
 
-flask_session
-instance
-
 .DS_Store
 .idea
 
+instance
+flask_session
+
+.scannerwork
+sonar-project.properties
+
 excludes

MANIFEST.in

@@ -15,4 +15,8 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
+include docs/*
+include docs/source/*
+include docs/source/_static/*
+include docs/source/_templates/*
 include tests/*

README.rst

@@ -6,35 +6,68 @@ Flask HTTP Digest Authentication
 Description
 ===========
 
-*Flask-Digest-Auth* is an HTTP Digest Authentication implementation
+*Flask-Digest-Auth* is an `HTTP Digest Authentication`_ implementation
 for Flask_ applications.  It authenticates the user for the protected
-views.  It works with Flask-Login_, so that log in protection can be
-separated with the authentication mechanism.  You can write Flask
-modules that work with different authentication mechanisms.
+views.
 
-.. _Flask: https://flask.palletsprojects.com
-.. _Flask-Login: https://flask-login.readthedocs.io
+HTTP Digest Authentication is specified in `RFC 2617`_.
+
+Refer to the full `Flask-Digest-Auth readthedocs documentation`_.
+
+
+Why HTTP Digest Authentication?
+-------------------------------
+
+*HTTP Digest Authentication* has the advantage that it does not send
+thee 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.
 
 
 Installation
 ============
 
-It's suggested that you install with ``pip``:
+You can install Flask-Digest-Auth with ``pip``:
 
 ::
 
-    pip install flask-digest-auth
+    pip install Flask-Digest-Auth
 
 You may also install the latest source from the
-`flask-digest-auth Github repository`_.
+`Flask-Digest-Auth GitHub repository`_.
 
 ::
 
-    git clone git@github.com:imacat/flask-digest-auth.git
-    cd flask-digest-auth
-    pip install .
+    pip install git+https://github.com/imacat/flask-digest-auth.git
 
-.. _flask-digest-auth Github repository: https://github.com/imacat/flask-digest-auth
+
+Setting the Password
+====================
+
+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.
 
 
 Flask-Digest-Auth Alone
@@ -43,20 +76,21 @@ Flask-Digest-Auth Alone
 Flask-Digest-Auth can authenticate the users alone.
 
 
-Example for Simple Applications with Flask-Digest-Auth Alone
-------------------------------------------------------------
+Simple Applications with Flask-Digest-Auth Alone
+------------------------------------------------
 
 In your ``my_app.py``:
 
 ::
 
-    from flask import Flask
+    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]:
@@ -69,15 +103,21 @@ In your ``my_app.py``:
     @app.get("/admin")
     @auth.login_required
     def admin():
-        ... (Process the view) ...
+        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
-----------------------------------------------------------------------------------
+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
@@ -89,6 +129,7 @@ In your ``my_app/__init__.py``:
         ... (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]:
@@ -105,43 +146,61 @@ In your ``my_app/views.py``:
 ::
 
     from my_app import auth
-    from flask import Flask, Blueprint
+    from flask import Flask, Blueprint, request, redirect
 
     bp = Blueprint("admin", __name__, url_prefix="/admin")
 
-    @bp.get("/")
+    @bp.get("/admin")
     @auth.login_required
     def admin():
-        ... (Process the view) ...
+        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.
+Flask-Digest-Auth works with Flask-Login_.  You can write a Flask
+module that requires log in, without specifying how to log in.  The
+application can use either HTTP Digest Authentication, or the log in
+forms, as needed.
+
+To use Flask-Login with Flask-Digest-Auth,
+``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.
+
+The views only depend on Flask-Login, but not the Flask-Digest-Auth.
+You can change the actual authentication mechanism without changing
+the views.
 
 
-Example for Simple Applications with Flask-Login Integration
-------------------------------------------------------------
+Simple Applications with Flask-Login Integration
+------------------------------------------------
 
 In your ``my_app.py``:
 
 ::
 
-    from flask import Flask
+    import flask_login
+    from flask import Flask, request, redirect
     from flask_digest_auth import DigestAuth
-    from flask_login import LoginManager
 
     app: flask = Flask(__name__)
     ... (Configure the Flask application) ...
 
-    login_manager: LoginManager = LoginManager()
+    login_manager: flask_login.LoginManager = flask_login.LoginManager()
     login_manager.init_app(app)
 
     @login_manager.user_loader
@@ -156,22 +215,31 @@ In your ``my_app.py``:
         ... (Load the password hash) ...
 
     @app.get("/admin")
-    @login_manager.login_required
+    @flask_login.login_required
     def admin():
-        ... (Process the view) ...
+        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
-----------------------------------------------------------------------------------
+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) ...
@@ -183,7 +251,7 @@ In your ``my_app/__init__.py``:
         def load_user(user_id: str) -> t.Optional[User]:
             ... (Load the user with the username) ...
 
-        auth: DigestAuth = DigestAuth(realm=app.config["REALM"])
+        auth.realm = app.config["REALM"]
         auth.init_app(app)
 
         @auth.register_get_password
@@ -197,33 +265,73 @@ In your ``my_app/views.py``:
 ::
 
     import flask_login
-    from flask import Flask, Blueprint
+    from flask import Flask, Blueprint, request, redirect
+    from my_app import auth
 
     bp = Blueprint("admin", __name__, url_prefix="/admin")
 
-    @bp.get("/")
+    @bp.get("/admin")
     @flask_login.login_required
     def admin():
-        ... (Process the view) ...
+        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 its underlying
-authentication mechanism.  You can always change the
-authentication mechanism without changing the views, or release a
-protected Flask module without specifying the authentication
-mechanism.
+The views only depend on Flask-Login, but not the actual
+authentication mechanism.  You can change the actual authentication
+mechanism without changing the views.
 
 
-Writing Tests
-=============
+Session Integration
+===================
 
-You can write tests with our test client that handles HTTP Digest
-Authentication.  Example for a unittest testcase:
+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 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
+
+
+Log Out
+=======
+
+Flask-Digest-Auth supports log out.  The user will be prompted for the
+new username and password.
+
+
+Test Client
+===========
+
+Flask-Digest-Auth comes with a test client that supports HTTP digest
+authentication.
+
+
+A unittest Test Case
+--------------------
+
+::
+
+    from flask import Flask
     from flask_digest_auth import Client
     from flask_testing import TestCase
     from my_app import create_app
@@ -246,6 +354,38 @@ Authentication.  Example for a unittest testcase:
             self.assertEqual(response.status_code, 200)
 
 
+A pytest Test
+-------------
+
+::
+
+    import pytest
+    from flask import Flask
+    from flask_digest_auth import Client
+    from my_app import create_app
+
+    @pytest.fixture()
+    def app():
+        app: Flask = create_app({
+            "SECRET_KEY": token_urlsafe(32),
+            "TESTING": True
+        })
+        app.test_client_class = Client
+        yield app
+
+    @pytest.fixture()
+    def client(app):
+        return app.test_client()
+
+    def test_admin(app: Flask, client: Client):
+        with app.app_context():
+            response = self.client.get("/admin")
+            assert response.status_code == 401
+            response = self.client.get(
+                "/admin", digest_auth=("my_name", "my_pass"))
+            assert response.status_code == 200
+
+
 Copyright
 =========
 
@@ -263,9 +403,17 @@ Copyright
  See the License for the specific language governing permissions and
  limitations under the License.
 
+
 Authors
 =======
 
 | imacat
 | imacat@mail.imacat.idv.tw
 | 2022/11/23
+
+.. _HTTP Digest Authentication: https://en.wikipedia.org/wiki/Digest_access_authentication
+.. _RFC 2617: https://www.rfc-editor.org/rfc/rfc2617
+.. _Flask: https://flask.palletsprojects.com
+.. _Flask-Digest-Auth GitHub repository: https://github.com/imacat/flask-digest-auth
+.. _Flask-Digest-Auth readthedocs documentation: https://flask-digest-auth.readthedocs.io
+.. _Flask-Login: https://flask-login.readthedocs.io

docs/Makefile

@@ -0,0 +1,20 @@
+# Minimal makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line, and also
+# from the environment for the first two.
+SPHINXOPTS    ?=
+SPHINXBUILD   ?= sphinx-build
+SOURCEDIR     = source
+BUILDDIR      = build
+
+# Put it first so that "make" without argument is like "make help".
+help:
+	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+.PHONY: help Makefile
+
+# Catch-all target: route all unknown targets to Sphinx using the new
+# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
+%: Makefile
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

docs/make.bat

@@ -0,0 +1,35 @@
+@ECHO OFF
+
+pushd %~dp0
+
+REM Command file for Sphinx documentation
+
+if "%SPHINXBUILD%" == "" (
+	set SPHINXBUILD=sphinx-build
+)
+set SOURCEDIR=source
+set BUILDDIR=build
+
+if "%1" == "" goto help
+
+%SPHINXBUILD% >NUL 2>NUL
+if errorlevel 9009 (
+	echo.
+	echo.The 'sphinx-build' command was not found. Make sure you have Sphinx
+	echo.installed, then set the SPHINXBUILD environment variable to point
+	echo.to the full path of the 'sphinx-build' executable. Alternatively you
+	echo.may add the Sphinx directory to PATH.
+	echo.
+	echo.If you don't have Sphinx installed, grab it from
+	echo.http://sphinx-doc.org/
+	exit /b 1
+)
+
+%SPHINXBUILD% -M %1 %SOURCEDIR% %BUILDDIR% %SPHINXOPTS% %O%
+goto end
+
+:help
+%SPHINXBUILD% -M help %SOURCEDIR% %BUILDDIR% %SPHINXOPTS% %O%
+
+:end
+popd

docs/requirements.txt

@@ -0,0 +1 @@
+flask

docs/source/conf.py

@@ -0,0 +1,59 @@
+# Configuration file for the Sphinx documentation builder.
+#
+# This file only contains a selection of the most common options. For a full
+# list see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+import os
+# -- Path setup --------------------------------------------------------------
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+import sys
+
+sys.path.insert(0, os.path.abspath('../../src/'))
+
+
+# -- Project information -----------------------------------------------------
+
+project = 'Flask-Digest-Auth'
+copyright = '2022, imacat'
+author = 'imacat'
+
+# The full version, including alpha/beta/rc tags
+release = '0.2.3'
+
+
+# -- General configuration ---------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    "sphinx.ext.autodoc"
+]
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This pattern also affects html_static_path and html_extra_path.
+exclude_patterns = []
+
+
+# -- Options for HTML output -------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = 'sphinx_rtd_theme'
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# For readthedocs.io to work properly.
+master_doc = 'index'

docs/source/examples.rst

@@ -0,0 +1,268 @@
+Examples
+========
+
+
+.. _example-alone-simple:
+
+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-alone-large:
+
+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)
+
+
+.. _example-flask-login-simple:
+
+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-flask-login-large:
+
+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.
+
+
+.. _example-unittest:
+
+A unittest Test Case
+--------------------
+
+::
+
+    from flask import Flask
+    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)
+
+
+
+.. _example-pytest:
+
+A pytest Test
+-------------
+
+::
+
+    import pytest
+    from flask import Flask
+    from flask_digest_auth import Client
+    from my_app import create_app
+
+    @pytest.fixture()
+    def app():
+        app: Flask = create_app({
+            "SECRET_KEY": token_urlsafe(32),
+            "TESTING": True
+        })
+        app.test_client_class = Client
+        yield app
+
+    @pytest.fixture()
+    def client(app):
+        return app.test_client()
+
+    def test_admin(app: Flask, client: Client):
+        with app.app_context():
+            response = self.client.get("/admin")
+            assert response.status_code == 401
+            response = self.client.get(
+                "/admin", digest_auth=("my_name", "my_pass"))
+            assert response.status_code == 200

docs/source/flask_digest_auth.rst

@@ -0,0 +1,24 @@
+flask\_digest\_auth package
+===========================
+
+The ``DigestAuth`` Class
+------------------------
+.. autoclass:: flask_digest_auth.DigestAuth
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
+The ``make_password_hash`` Function
+-----------------------------------
+.. autofunction:: flask_digest_auth.make_password_hash
+
+The ``calc_response`` Function
+------------------------------
+.. autofunction:: flask_digest_auth.calc_response
+
+The ``Client`` Test Class
+-------------------------
+.. autoclass:: flask_digest_auth.Client
+    :members:
+    :undoc-members:
+    :show-inheritance:

docs/source/index.rst

@@ -0,0 +1,34 @@
+.. flask-digest-auth documentation master file, created by
+   sphinx-quickstart on Tue Dec  6 15:15:08 2022.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Welcome to Flask-Digest-Auth's documentation!
+=============================================
+
+*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`_.
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contents:
+
+   intro
+   flask_digest_auth
+   examples
+
+
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`
+
+.. _HTTP Digest Authentication: https://en.wikipedia.org/wiki/Digest_access_authentication
+.. _RFC 2617: https://www.rfc-editor.org/rfc/rfc2617
+.. _Flask: https://flask.palletsprojects.com

docs/source/intro.rst

@@ -0,0 +1,148 @@
+Introduction
+============
+
+
+*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.
+
+
+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`_.
+
+::
+
+    pip install git+https://github.com/imacat/flask-digest-auth.git
+
+
+Setting the Password
+--------------------
+
+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.
+
+See :meth:`flask_digest_auth.make_password_hash`.
+
+
+Flask-Digest-Auth Alone
+-----------------------
+
+Flask-Digest-Auth can authenticate the users alone.
+
+See :ref:`example-alone-simple` and :ref:`example-alone-large`.
+
+
+Flask-Login Integration
+-----------------------
+
+Flask-Digest-Auth works with Flask-Login_.  You can write a Flask
+module that requires log in, without specifying how to log in.  The
+application can use either HTTP Digest Authentication, or the log in
+forms, as needed.
+
+To use Flask-Login with Flask-Digest-Auth,
+``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.
+
+See :ref:`example-flask-login-simple` and
+:ref:`example-flask-login-large`.
+
+The views only depend on Flask-Login, but not the Flask-Digest-Auth.
+You can change the actual authentication mechanism without changing
+the views.
+
+
+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 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
+
+See :meth:`flask_digest_auth.DigestAuth.register_on_login`.
+
+
+Log Out
+-------
+
+Flask-Digest-Auth supports log out.  The user will be prompted for the
+new username and password.
+
+See :meth:`flask_digest_auth.DigestAuth.logout`.
+
+
+Test Client
+-----------
+
+Flask-Digest-Auth comes with a test client that supports HTTP digest
+authentication.
+
+See :class:`flask_digest_auth.Client`.
+
+Also see :ref:`example-unittest` and :ref:`example-pytest`.
+
+
+.. _HTTP Digest Authentication: https://en.wikipedia.org/wiki/Digest_access_authentication
+.. _RFC 2617: https://www.rfc-editor.org/rfc/rfc2617
+.. _Flask: https://flask.palletsprojects.com
+.. _Flask-Login: https://flask-login.readthedocs.io
+.. _Flask-Digest-Auth GitHub repository: https://github.com/imacat/flask-digest-auth

setup.cfg

@@ -17,7 +17,7 @@
 
 [metadata]
 name = flask-digest-auth
-version = 0.1.1
+version = 0.2.3
 author = imacat
 author_email = imacat@mail.imacat.idv.tw
 description = The Flask HTTP Digest Authentication project.

src/flask_digest_auth/algo.py

@@ -23,11 +23,16 @@ from __future__ import annotations
 import typing as t
 from hashlib import md5
 
-from flask_digest_auth.exception import UnauthorizedException
-
 
 def make_password_hash(realm: str, username: str, password: str) -> str:
     """Calculates the password hash for the HTTP digest authentication.
+    Use this function to set the password for the user.
+
+    For example:
+
+    ::
+
+        user.password = make_password_hash(realm, username, password)
 
     :param realm: The realm.
     :param username: The username.
@@ -49,67 +54,53 @@ def calc_response(
     :param uri: The request URI.
     :param password_hash: The password hash for the HTTP digest authentication.
     :param nonce: The nonce.
-    :param qop: the quality of protection.
-    :param algorithm: The algorithm, either "MD5" or "MD5-sess".
+    :param qop: the quality of protection, either ``auth`` or ``auth-int``.
+    :param algorithm: The algorithm, either ``MD5`` or ``MD5-sess``.
     :param cnonce: The client nonce, which must exists when qop exists or
-        algorithm="MD5-sess".
+        algorithm is ``MD5-sess``.
     :param nc: The request counter, which must exists when qop exists.
-    :param body: The request body, which must exists when qop="auth-int".
+    :param body: The request body, which must exists when qop is ``auth-int``.
     :return: The response value.
-    :raise UnauthorizedException: When the cnonce is missing with the MD5-sess
-        algorithm, when the body is missing with the auth-int qop, or when the
-        cnonce or nc is missing with the auth or auth-int qop.
+    :raise AssertionError: When cnonce is missing with algorithm is
+        ``MD5-sess``, when body is missing with qop is ``auth-int``, or when
+        cnonce or nc is missing with qop exits.
     """
 
     def calc_ha1() -> str:
         """Calculates and returns the first hash.
 
         :return: The first hash.
-        :raise UnauthorizedException: When the cnonce is missing with the MD5-sess
-            algorithm.
+        :raise AssertionError: When cnonce is missing with
+            algorithm is ``MD5-sess``.
         """
-        if algorithm is None or algorithm == "MD5":
-            return password_hash
         if algorithm == "MD5-sess":
-            if cnonce is None:
-                raise UnauthorizedException(
-                    f"Missing \"cnonce\" with algorithm=\"{algorithm}\"")
+            assert cnonce is not None,\
+                f"Missing \"cnonce\" with algorithm=\"{algorithm}\""
             return md5(f"{password_hash}:{nonce}:{cnonce}".encode("utf8")) \
                 .hexdigest()
-        raise UnauthorizedException(
-            f"Unsupported algorithm=\"{algorithm}\"")
+        # algorithm is None or algorithm == "MD5"
+        return password_hash
 
     def calc_ha2() -> str:
         """Calculates the second hash.
 
         :return: The second hash.
-        :raise UnauthorizedException: When the body is missing with
-            qop="auth-int".
+        :raise AssertionError: When body is missing with qop is ``auth-int``.
         """
-        if qop is None or qop == "auth":
-            return md5(f"{method}:{uri}".encode("utf8")).hexdigest()
         if qop == "auth-int":
-            if body is None:
-                raise UnauthorizedException(
-                    f"Missing \"body\" with qop=\"{qop}\"")
+            assert body is not None, f"Missing \"body\" with qop=\"{qop}\""
             return md5(
                 f"{method}:{uri}:{md5(body).hexdigest()}".encode("utf8")) \
                 .hexdigest()
-        raise UnauthorizedException(f"Unsupported qop=\"{qop}\"")
+        # qop is None or qop == "auth"
+        return md5(f"{method}:{uri}".encode("utf8")).hexdigest()
 
     ha1: str = calc_ha1()
     ha2: str = calc_ha2()
-    if qop is None:
-        return md5(f"{ha1}:{nonce}:{ha2}".encode("utf8")).hexdigest()
     if qop == "auth" or qop == "auth-int":
-        if cnonce is None:
-            raise UnauthorizedException(
-                f"Missing \"cnonce\" with the qop=\"{qop}\"")
-        if nc is None:
-            raise UnauthorizedException(
-                f"Missing \"nc\" with the qop=\"{qop}\"")
+        assert cnonce is not None, f"Missing \"cnonce\" with the qop=\"{qop}\""
+        assert nc is not None, f"Missing \"nc\" with the qop=\"{qop}\""
         return md5(f"{ha1}:{nonce}:{nc}:{cnonce}:{qop}:{ha2}".encode("utf8"))\
             .hexdigest()
-    if cnonce is None:
-        raise UnauthorizedException(
-            f"Unsupported qop=\"{qop}\"")
+    # qop is None
+    return md5(f"{ha1}:{nonce}:{ha2}".encode("utf8")).hexdigest()

src/flask_digest_auth/auth.py

@@ -24,15 +24,13 @@ from __future__ import annotations
 import sys
 import typing as t
 from functools import wraps
-from random import random
-from secrets import token_urlsafe
+from secrets import token_urlsafe, randbits
 
 from flask import g, request, Response, session, abort, Flask, Request
 from itsdangerous import URLSafeTimedSerializer, BadData
 from werkzeug.datastructures import Authorization
 
 from flask_digest_auth.algo import calc_response
-from flask_digest_auth.exception import UnauthorizedException
 
 
 class DigestAuth:
@@ -51,20 +49,63 @@ class DigestAuth:
         self.use_opaque: bool = True
         self.domain: t.List[str] = []
         self.qop: t.List[str] = ["auth", "auth-int"]
-        self.__get_password_hash: t.Callable[[str], t.Optional[str]] \
-            = lambda x: None
-        self.__get_user: t.Callable[[str], t.Optional] = lambda x: None
+        self.app: t.Optional[Flask] = None
+        self.__get_password_hash: BasePasswordHashGetter \
+            = BasePasswordHashGetter()
+        self.__get_user: BaseUserGetter = BaseUserGetter()
+        self.__on_login: BaseOnLogInCallback = BaseOnLogInCallback()
 
     def login_required(self, view) -> t.Callable:
         """The view decorator for HTTP digest authentication.
 
-        :param view:
+        For example:
+
+        ::
+
+            @auth.login_required
+            def admin():
+                return f"Hello, {g.user.username}!"
+
+        The logged-in user can be retrieved at ``g.user``.
+
+        :param view: The view.
         :return: The login-protected view.
         """
 
         class NoLogInException(Exception):
             """The exception thrown when the user is not authorized."""
 
+        def get_logged_in_user() -> t.Any:
+            """Returns the currently logged-in user.
+
+            :return: The currently logged-in user.
+            :raise NoLogInException: When the user is not logged in.
+            """
+            if "user" not in session:
+                raise NoLogInException
+            user: t.Optional[t.Any] = self.__get_user(session["user"])
+            if user is None:
+                del session["user"]
+                raise NoLogInException
+            return user
+
+        def auth_user(state: AuthState) -> t.Any:
+            """Authenticates a user.
+
+            :param state: The authentication state.
+            :return: The user.
+            :raise UnauthorizedException: When the authentication fails.
+            """
+            authorization: Authorization = request.authorization
+            if authorization is None:
+                raise UnauthorizedException
+            if authorization.type != "digest":
+                raise UnauthorizedException(
+                    "Not an HTTP digest authorization")
+            self.__authenticate(state)
+            session["user"] = authorization.username
+            return self.__get_user(authorization.username)
+
         @wraps(view)
         def login_required_view(*args, **kwargs) -> t.Any:
             """The login-protected view.
@@ -74,44 +115,37 @@ class DigestAuth:
             :return: The response.
             """
             try:
-                if "user" not in session:
-                    raise NoLogInException
-                user: t.Optional[t.Any] = self.__get_user(session["user"])
-                if user is None:
-                    raise NoLogInException
-                g.user = user
+                g.user = get_logged_in_user()
                 return view(*args, **kwargs)
             except NoLogInException:
-                state: AuthState = AuthState()
-                authorization: Authorization = request.authorization
-                try:
-                    if authorization is None:
-                        raise UnauthorizedException
-                    if authorization.type != "digest":
-                        raise UnauthorizedException(
-                            "Not an HTTP digest authorization")
-                    self.authenticate(state)
-                    session["user"] = authorization.username
-                    g.user = self.__get_user(authorization.username)
-                    return view(*args, **kwargs)
-                except UnauthorizedException as e:
-                    if len(e.args) > 0:
-                        sys.stderr.write(e.args[0] + "\n")
-                    response: Response = Response()
-                    response.status = 401
-                    response.headers["WWW-Authenticate"] \
-                        = self.make_response_header(state)
-                    abort(response)
+                pass
+
+            state: AuthState = AuthState()
+            try:
+                g.user = auth_user(state)
+                self.__on_login(g.user)
+                return view(*args, **kwargs)
+            except UnauthorizedException as e:
+                if len(e.args) > 0:
+                    sys.stderr.write(e.args[0] + "\n")
+                response: Response = Response()
+                response.status = 401
+                response.headers["WWW-Authenticate"] \
+                    = self.__make_response_header(state)
+                abort(response)
 
         return login_required_view
 
-    def authenticate(self, state: AuthState) -> None:
+    def __authenticate(self, state: AuthState) -> None:
         """Authenticate a user.
 
         :param state: The authorization state.
         :return: None.
         :raise UnauthorizedException: When the authentication failed.
         """
+        if "digest_auth_logout" in session:
+            del session["digest_auth_logout"]
+            raise UnauthorizedException("Logging out")
         authorization: Authorization = request.authorization
         if self.use_opaque:
             if authorization.opaque is None:
@@ -123,8 +157,8 @@ class DigestAuth:
             except BadData:
                 raise UnauthorizedException("Invalid opaque")
             state.opaque = authorization.opaque
-        password_hash: t.Optional[str] = self.__get_password_hash(
-            authorization.username)
+        password_hash: t.Optional[str] \
+            = self.__get_password_hash(authorization.username)
         if password_hash is None:
             raise UnauthorizedException(
                 f"No such user \"{authorization.username}\"")
@@ -147,17 +181,28 @@ class DigestAuth:
             state.stale = True
             raise UnauthorizedException("Invalid nonce")
 
-    def make_response_header(self, state: AuthState) -> str:
-        """Composes and returns the WWW-Authenticate response header.
+    def __make_response_header(self, state: AuthState) -> str:
+        """Composes and returns the ``WWW-Authenticate`` response header.
 
         :param state: The authorization state.
-        :return: The WWW-Authenticate response header.
+        :return: The ``WWW-Authenticate`` response header.
         """
-        opaque: t.Optional[str] = None if not self.use_opaque else \
-            (state.opaque if state.opaque is not None
-             else self.serializer.dumps(random(), salt="opaque"))
+
+        def get_opaque() -> t.Optional[str]:
+            """Returns the opaque value.
+
+            :return: The opaque value.
+            """
+            if not self.use_opaque:
+                return None
+            if state.opaque is not None:
+                return state.opaque
+            return self.serializer.dumps(randbits(32), salt="opaque")
+
+        opaque: t.Optional[str] = get_opaque()
         nonce: str = self.serializer.dumps(
-            random(), salt="nonce" if opaque is None else f"nonce-{opaque}")
+            randbits(32),
+            salt="nonce" if opaque is None else f"nonce-{opaque}")
 
         header: str = f"Digest realm=\"{self.realm}\""
         if len(self.domain) > 0:
@@ -177,37 +222,117 @@ class DigestAuth:
 
     def register_get_password(self, func: t.Callable[[str], t.Optional[str]])\
             -> None:
-        """Registers the callback to obtain the password hash.
+        """The decorator to register the callback to obtain the password hash.
+
+        For example:
+
+        ::
+
+            @auth.register_get_password
+            def get_password_hash(username: str) -> Optional[str]:
+                user = User.query.filter(User.username == username).first()
+                return None if user is None else user.password
 
         :param func: The callback that given the username, returns the password
             hash, or None if the user does not exist.
         :return: None.
         """
-        self.__get_password_hash = func
+
+        class PasswordHashGetter(BasePasswordHashGetter):
+            """The base password hash getter."""
+
+            @staticmethod
+            def __call__(username: str) -> t.Optional[str]:
+                """Returns the password hash of a user.
+
+                :param username: The username.
+                :return: The password hash, or None if the user does not exist.
+                """
+                return func(username)
+
+        self.__get_password_hash = PasswordHashGetter()
 
     def register_get_user(self, func: t.Callable[[str], t.Optional[t.Any]])\
             -> None:
-        """Registers the callback to obtain the user.
+        """The decorator to register the callback to obtain the user.
+
+        For example:
+
+        ::
+
+            @auth.register_get_user
+            def get_user(username: str) -> Optional[User]:
+                return User.query.filter(User.username == username).first()
 
         :param func: The callback that given the username, returns the user,
             or None if the user does not exist.
         :return: None.
         """
-        self.__get_user = func
+
+        class UserGetter(BaseUserGetter):
+            """The user getter."""
+
+            @staticmethod
+            def __call__(username: str) -> t.Optional[t.Any]:
+                """Returns a user.
+
+                :param username: The username.
+                :return: The user, or None if the user does not exist.
+                """
+                return func(username)
+
+        self.__get_user = UserGetter()
+
+    def register_on_login(self, func: t.Callable[[t.Any], None]) -> None:
+        """The decorator to register the callback to run when the user logs in.
+
+        For example:
+
+        ::
+
+            @auth.register_on_login
+            def on_login(user: User) -> None:
+                user.visits = user.visits + 1
+
+        :param func: The callback given the logged-in user.
+        :return: None.
+        """
+
+        class OnLogInCallback:
+            """The callback when the user logs in."""
+
+            @staticmethod
+            def __call__(user: t.Any) -> None:
+                """Runs the callback when the user logs in.
+
+                :param user: The logged-in user.
+                :return: None.
+                """
+                func(user)
+
+        self.__on_login = OnLogInCallback()
 
     def init_app(self, app: Flask) -> None:
         """Initializes the Flask application.
 
+        For example:
+
+        ::
+
+            app: flask = Flask(__name__)
+            auth: DigestAuth = DigestAuth()
+            auth.realm = "My Admin"
+            auth.init_app(app)
+
         :param app: The Flask application.
         :return: None.
         """
+        app.digest_auth = self
+        self.app = app
 
-        try:
+        if hasattr(app, "login_manager"):
             from flask_login import LoginManager, login_user
 
-            if not hasattr(app, "login_manager"):
-                raise AttributeError(
-                    "Please run the Flask-Login init-app() first")
             login_manager: LoginManager = getattr(app, "login_manager")
 
             @login_manager.unauthorized_handler
@@ -219,7 +344,7 @@ class DigestAuth:
                 response: Response = Response()
                 response.status = 401
                 response.headers["WWW-Authenticate"] \
-                    = self.make_response_header(g.digest_auth_state)
+                    = self.__make_response_header(g.digest_auth_state)
                 abort(response)
 
             @login_manager.request_loader
@@ -238,19 +363,43 @@ class DigestAuth:
                     if authorization.type != "digest":
                         raise UnauthorizedException(
                             "Not an HTTP digest authorization")
-                    self.authenticate(g.digest_auth_state)
+                    self.__authenticate(g.digest_auth_state)
                     user = login_manager.user_callback(
                         authorization.username)
                     login_user(user)
+                    self.__on_login(user)
                     return user
                 except UnauthorizedException as e:
                     if str(e) != "":
                         app.logger.warning(str(e))
                     return None
 
+    def logout(self) -> None:
+        """Logs out the user.
+        This actually causes the next authentication to fail, which forces
+        the browser to ask the user for the username and password again.
+
+        For example:
+
+        ::
+
+            @app.post("/logout")
+            @auth.login_required
+            def logout():
+                auth.logout()
+                return redirect(request.form.get("next"))
+
+        :return: None.
+        """
+        if "user" in session:
+            del session["user"]
+        try:
+            if hasattr(self.app, "login_manager"):
+                from flask_login import logout_user
+                logout_user()
         except ModuleNotFoundError:
-            raise ModuleNotFoundError(
-                "init_app() is only for Flask-Login integration")
+            pass
+        session["digest_auth_logout"] = True
 
 
 class AuthState:
@@ -260,3 +409,52 @@ class AuthState:
         """Constructs the authorization state."""
         self.opaque: t.Optional[str] = None
         self.stale: t.Optional[bool] = None
+
+
+class UnauthorizedException(Exception):
+    """The exception thrown when the authentication is failed."""
+    pass
+
+
+class BasePasswordHashGetter:
+    """The base password hash getter."""
+
+    @staticmethod
+    def __call__(username: str) -> t.Optional[str]:
+        """Returns the password hash of a user.
+
+        :param username: The username.
+        :return: The password hash, or None if the user does not exist.
+        :raise UnboundLocalError: When the password hash getter function is
+            not registered yet.
+        """
+        raise UnboundLocalError("The function to return the password hash"
+                                " was not registered yet.")
+
+
+class BaseUserGetter:
+    """The base user getter."""
+
+    @staticmethod
+    def __call__(username: str) -> t.Optional[t.Any]:
+        """Returns a user.
+
+        :param username: The username.
+        :return: The user, or None if the user does not exist.
+        :raise UnboundLocalError: When the user getter function is not
+            registered yet.
+        """
+        raise UnboundLocalError("The function to return the user"
+                                " was not registered yet.")
+
+
+class BaseOnLogInCallback:
+    """The base callback when the user logs in."""
+
+    @staticmethod
+    def __call__(user: t.Any) -> None:
+        """Runs the callback when the user logs in.
+
+        :param user: The logged-in user.
+        :return: None.
+        """

src/flask_digest_auth/exception.py

@@ -1,25 +0,0 @@
-# The Flask HTTP Digest Authentication Project.
-# Author: imacat@mail.imacat.idv.tw (imacat), 2022/11/3
-
-#  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-2.0
-#
-#  Unless 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.
-
-"""The exception.
-
-"""
-
-
-class UnauthorizedException(Exception):
-    """The exception thrown when the authentication is failed."""
-    pass

src/flask_digest_auth/test.py

@@ -29,15 +29,62 @@ from flask_digest_auth.algo import calc_response, make_password_hash
 
 
 class Client(WerkzeugClient):
-    """The test client with HTTP digest authentication enabled."""
+    """The test client with HTTP digest authentication enabled.
+
+    For unittest example:
+
+    ::
+
+        class MyTestCase(flask_testing.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)
+
+    For pytest example:
+
+    ::
+
+        @pytest.fixture()
+        def app():
+            app: Flask = create_app({
+                "SECRET_KEY": token_urlsafe(32),
+                "TESTING": True
+            })
+            app.test_client_class = Client
+            yield app
+
+        @pytest.fixture()
+        def client(app):
+            return app.test_client()
+
+        def test_admin(app: Flask, client: Client):
+            with app.app_context():
+                response = self.client.get("/admin")
+                assert response.status_code == 401
+                response = self.client.get(
+                    "/admin", digest_auth=("my_name", "my_pass"))
+                assert response.status_code == 200
+    """
 
     def open(self, *args, digest_auth: t.Optional[t.Tuple[str, str]] = None,
              **kwargs) -> TestResponse:
         """Opens a request.
 
         :param args: The arguments.
-        :param digest_auth: The username and password for the HTTP digest
-            authentication.
+        :param digest_auth: A tuple of the username and password for the HTTP
+            digest authentication.
         :param kwargs: The keyword arguments.
         :return: The response.
         """
@@ -49,26 +96,25 @@ class Client(WerkzeugClient):
             return response
         if hasattr(g, "_login_user"):
             delattr(g, "_login_user")
-        auth_data: Authorization = self.__class__.__make_authorization(
+        auth_data: Authorization = self.__class__.make_authorization(
             www_authenticate, args[0], digest_auth[0], digest_auth[1])
         response = super(Client, self).open(*args, auth=auth_data, **kwargs)
         return response
 
     @staticmethod
-    def __make_authorization(www_authenticate: WWWAuthenticate, uri: str,
-                             username: str, password: str) -> Authorization:
+    def make_authorization(www_authenticate: WWWAuthenticate, uri: str,
+                           username: str, password: str) -> Authorization:
         """Composes and returns the request authorization.
 
-        :param www_authenticate: The WWW-Authenticate response.
+        :param www_authenticate: The ``WWW-Authenticate`` response.
         :param uri: The request URI.
         :param username: The username.
         :param password: The password.
         :return: The request authorization.
         """
         qop: t.Optional[t.Literal["auth", "auth-int"]] = None
-        if www_authenticate.qop is not None:
-            if "auth" in www_authenticate.qop:
-                qop = "auth"
+        if www_authenticate.qop is not None and "auth" in www_authenticate.qop:
+            qop = "auth"
 
         cnonce: t.Optional[str] = None
         if qop is not None or www_authenticate.algorithm == "MD5-sess":

tests/test_auth.py

@@ -20,10 +20,10 @@
 """
 import typing as t
 from secrets import token_urlsafe
-from types import SimpleNamespace
 
-from flask import Response, Flask, g
+from flask import Response, Flask, g, redirect, request
 from flask_testing import TestCase
+from werkzeug.datastructures import WWWAuthenticate, Authorization
 
 from flask_digest_auth import DigestAuth, make_password_hash, Client
 
@@ -32,6 +32,21 @@ _USERNAME: str = "Mufasa"
 _PASSWORD: str = "Circle Of Life"
 
 
+class User:
+    """A dummy user"""
+
+    def __init__(self, username: str, password: str):
+        """Constructs a dummy user.
+
+        :param username: The username.
+        :param password: The clear-text password.
+        """
+        self.username: str = username
+        self.password_hash: str = make_password_hash(
+            _REALM, username, password)
+        self.visits: int = 0
+
+
 class AuthenticationTestCase(TestCase):
     """The test case for the HTTP digest authentication."""
 
@@ -48,8 +63,9 @@ class AuthenticationTestCase(TestCase):
         app.test_client_class = Client
 
         auth: DigestAuth = DigestAuth(realm=_REALM)
-        user_db: t.Dict[str, str] \
-            = {_USERNAME: make_password_hash(_REALM, _USERNAME, _PASSWORD)}
+        auth.init_app(app)
+        self.user: User = User(_USERNAME, _PASSWORD)
+        user_db: t.Dict[str, User] = {_USERNAME: self.user}
 
         @auth.register_get_password
         def get_password_hash(username: str) -> t.Optional[str]:
@@ -58,7 +74,8 @@ class AuthenticationTestCase(TestCase):
             :param username: The username.
             :return: The password hash, or None if the user does not exist.
             """
-            return user_db[username] if username in user_db else None
+            return user_db[username].password_hash if username in user_db \
+                else None
 
         @auth.register_get_user
         def get_user(username: str) -> t.Optional[t.Any]:
@@ -67,27 +84,45 @@ class AuthenticationTestCase(TestCase):
             :param username: The username.
             :return: The user, or None if the user does not exist.
             """
-            return SimpleNamespace(username=username) if username in user_db \
-                else None
+            return user_db[username] if username in user_db else None
 
-        @app.get("/login-required-1/auth", endpoint="auth-1")
+        @auth.register_on_login
+        def on_login(user: User):
+            """The callback when the user logs in.
+
+            :param user: The logged-in user.
+            :return: None.
+            """
+            user.visits = user.visits + 1
+
+        @app.get("/admin-1/auth", endpoint="admin-1")
         @auth.login_required
-        def login_required_1() -> str:
-            """The first dummy view.
+        def admin_1() -> str:
+            """The first administration section.
 
             :return: The response.
             """
             return f"Hello, {g.user.username}! #1"
 
-        @app.get("/login-required-2/auth", endpoint="auth-2")
+        @app.get("/admin-2/auth", endpoint="admin-2")
         @auth.login_required
-        def login_required_2() -> str:
-            """The second dummy view.
+        def admin_2() -> str:
+            """The second administration section.
 
             :return: The response.
             """
             return f"Hello, {g.user.username}! #2"
 
+        @app.post("/logout", endpoint="logout")
+        @auth.login_required
+        def logout() -> redirect:
+            """Logs out the user.
+
+            :return: The response.
+            """
+            auth.logout()
+            return redirect(request.form.get("next"))
+
         return app
 
     def test_auth(self) -> None:
@@ -95,14 +130,92 @@ class AuthenticationTestCase(TestCase):
 
         :return: None.
         """
-        response: Response = self.client.get(self.app.url_for("auth-1"))
+        response: Response = self.client.get(self.app.url_for("admin-1"))
         self.assertEqual(response.status_code, 401)
         response = self.client.get(
-            self.app.url_for("auth-1"), digest_auth=(_USERNAME, _PASSWORD))
+            self.app.url_for("admin-1"), digest_auth=(_USERNAME, _PASSWORD))
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.data.decode("UTF-8"),
                          f"Hello, {_USERNAME}! #1")
-        response: Response = self.client.get(self.app.url_for("auth-2"))
+        response: Response = self.client.get(self.app.url_for("admin-2"))
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.data.decode("UTF-8"),
                          f"Hello, {_USERNAME}! #2")
+        self.assertEqual(self.user.visits, 1)
+
+    def test_stale_opaque(self) -> None:
+        """Tests the stale and opaque value.
+
+        :return: None.
+        """
+        admin_uri: str = self.app.url_for("admin-1")
+        response: Response
+        www_authenticate: WWWAuthenticate
+        auth_data: Authorization
+
+        response = super(Client, self.client).get(admin_uri)
+        self.assertEqual(response.status_code, 401)
+        www_authenticate = response.www_authenticate
+        self.assertEqual(www_authenticate.type, "digest")
+        self.assertEqual(www_authenticate.stale, None)
+        opaque: str = www_authenticate.opaque
+
+        www_authenticate.nonce = "bad"
+        auth_data = Client.make_authorization(
+            www_authenticate, admin_uri, _USERNAME, _PASSWORD)
+        response = super(Client, self.client).get(admin_uri, auth=auth_data)
+        self.assertEqual(response.status_code, 401)
+        www_authenticate = response.www_authenticate
+        self.assertEqual(www_authenticate.stale, True)
+        self.assertEqual(www_authenticate.opaque, opaque)
+
+        auth_data = Client.make_authorization(
+            www_authenticate, admin_uri, _USERNAME, _PASSWORD + "2")
+        response = super(Client, self.client).get(admin_uri, auth=auth_data)
+        self.assertEqual(response.status_code, 401)
+        www_authenticate = response.www_authenticate
+        self.assertEqual(www_authenticate.stale, False)
+        self.assertEqual(www_authenticate.opaque, opaque)
+
+        auth_data = Client.make_authorization(
+            www_authenticate, admin_uri, _USERNAME, _PASSWORD)
+        response = super(Client, self.client).get(admin_uri, auth=auth_data)
+        self.assertEqual(response.status_code, 200)
+
+    def test_logout(self) -> None:
+        """Tests the logging out.
+
+        :return: None.
+        """
+        admin_uri: str = self.app.url_for("admin-1")
+        logout_uri: str = self.app.url_for("logout")
+        response: Response
+
+        response = self.client.get(admin_uri)
+        self.assertEqual(response.status_code, 401)
+
+        response = self.client.get(admin_uri,
+                                   digest_auth=(_USERNAME, _PASSWORD))
+        self.assertEqual(response.status_code, 200)
+
+        response = self.client.get(admin_uri)
+        self.assertEqual(response.status_code, 200)
+
+        response = self.client.post(logout_uri, data={"next": admin_uri})
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.location, admin_uri)
+
+        response = self.client.get(admin_uri)
+        self.assertEqual(response.status_code, 401)
+
+        response = self.client.get(admin_uri,
+                                   digest_auth=(_USERNAME, _PASSWORD))
+        self.assertEqual(response.status_code, 401)
+
+        response = self.client.get(admin_uri,
+                                   digest_auth=(_USERNAME, _PASSWORD))
+        self.assertEqual(response.status_code, 200)
+
+        response = self.client.get(admin_uri)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(self.user.visits, 2)

tests/test_flask_login.py

@@ -21,8 +21,9 @@
 import typing as t
 from secrets import token_urlsafe
 
-from flask import Response, Flask
+from flask import Response, Flask, g, redirect, request
 from flask_testing import TestCase
+from werkzeug.datastructures import WWWAuthenticate, Authorization
 
 from flask_digest_auth import DigestAuth, make_password_hash, Client
 
@@ -32,8 +33,18 @@ _PASSWORD: str = "Circle Of Life"
 
 
 class User:
-    def __init__(self, username: str):
+    """A dummy user."""
+
+    def __init__(self, username: str, password: str):
+        """Constructs a dummy user.
+
+        :param username: The username.
+        :param password: The clear-text password.
+        """
         self.username: str = username
+        self.password_hash: str = make_password_hash(
+            _REALM, username, password)
+        self.visits: int = 0
         self.is_authenticated: bool = True
         self.is_active: bool = True
         self.is_anonymous: bool = False
@@ -75,8 +86,8 @@ class FlaskLoginTestCase(TestCase):
         auth: DigestAuth = DigestAuth(realm=_REALM)
         auth.init_app(app)
 
-        user_db: t.Dict[str, str] \
-            = {_USERNAME: make_password_hash(_REALM, _USERNAME, _PASSWORD)}
+        self.user: User = User(_USERNAME, _PASSWORD)
+        user_db: t.Dict[str, User] = {_USERNAME: self.user}
 
         @auth.register_get_password
         def get_password_hash(username: str) -> t.Optional[str]:
@@ -85,7 +96,17 @@ class FlaskLoginTestCase(TestCase):
             :param username: The username.
             :return: The password hash, or None if the user does not exist.
             """
-            return user_db[username] if username in user_db else None
+            return user_db[username].password_hash if username in user_db \
+                else None
+
+        @auth.register_on_login
+        def on_login(user: User):
+            """The callback when the user logs in.
+
+            :param user: The logged-in user.
+            :return: None.
+            """
+            user.visits = user.visits + 1
 
         @login_manager.user_loader
         def load_user(user_id: str) -> t.Optional[User]:
@@ -94,25 +115,35 @@ class FlaskLoginTestCase(TestCase):
             :param user_id: The username.
             :return: The user, or None if the user does not exist.
             """
-            return User(user_id) if user_id in user_db else None
+            return user_db[user_id] if user_id in user_db else None
 
-        @app.get("/login-required-1/auth", endpoint="auth-1")
+        @app.get("/admin-1/auth", endpoint="admin-1")
         @flask_login.login_required
-        def login_required_1() -> str:
-            """The first dummy view.
+        def admin_1() -> str:
+            """The first administration section.
 
             :return: The response.
             """
-            return f"Hello, {flask_login.current_user.username}! #1"
+            return f"Hello, {flask_login.current_user.get_id()}! #1"
 
-        @app.get("/login-required-2/auth", endpoint="auth-2")
+        @app.get("/admin-2/auth", endpoint="admin-2")
         @flask_login.login_required
-        def login_required_2() -> str:
-            """The second dummy view.
+        def admin_2() -> str:
+            """The second administration section.
 
             :return: The response.
             """
-            return f"Hello, {flask_login.current_user.username}! #2"
+            return f"Hello, {flask_login.current_user.get_id()}! #2"
+
+        @app.post("/logout", endpoint="logout")
+        @flask_login.login_required
+        def logout() -> redirect:
+            """Logs out the user.
+
+            :return: The response.
+            """
+            auth.logout()
+            return redirect(request.form.get("next"))
 
         return app
 
@@ -122,16 +153,106 @@ class FlaskLoginTestCase(TestCase):
         :return: None.
         """
         if not self.has_flask_login:
-            self.skipTest("Skipped testing Flask-Login integration without it.")
+            self.skipTest("Skipped without Flask-Login.")
 
-        response: Response = self.client.get(self.app.url_for("auth-1"))
+        response: Response = self.client.get(self.app.url_for("admin-1"))
         self.assertEqual(response.status_code, 401)
         response = self.client.get(
-            self.app.url_for("auth-1"), digest_auth=(_USERNAME, _PASSWORD))
+            self.app.url_for("admin-1"), digest_auth=(_USERNAME, _PASSWORD))
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.data.decode("UTF-8"),
                          f"Hello, {_USERNAME}! #1")
-        response: Response = self.client.get(self.app.url_for("auth-2"))
+        response: Response = self.client.get(self.app.url_for("admin-2"))
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.data.decode("UTF-8"),
                          f"Hello, {_USERNAME}! #2")
+        self.assertEqual(self.user.visits, 1)
+
+    def test_stale_opaque(self) -> None:
+        """Tests the stale and opaque value.
+
+        :return: None.
+        """
+        if not self.has_flask_login:
+            self.skipTest("Skipped without Flask-Login.")
+
+        admin_uri: str = self.app.url_for("admin-1")
+        response: Response
+        www_authenticate: WWWAuthenticate
+        auth_data: Authorization
+
+        response = super(Client, self.client).get(admin_uri)
+        self.assertEqual(response.status_code, 401)
+        www_authenticate = response.www_authenticate
+        self.assertEqual(www_authenticate.type, "digest")
+        self.assertEqual(www_authenticate.stale, None)
+        opaque: str = www_authenticate.opaque
+
+        if hasattr(g, "_login_user"):
+            delattr(g, "_login_user")
+        www_authenticate.nonce = "bad"
+        auth_data = Client.make_authorization(
+            www_authenticate, admin_uri, _USERNAME, _PASSWORD)
+        response = super(Client, self.client).get(admin_uri, auth=auth_data)
+        self.assertEqual(response.status_code, 401)
+        www_authenticate = response.www_authenticate
+        self.assertEqual(www_authenticate.stale, True)
+        self.assertEqual(www_authenticate.opaque, opaque)
+
+        if hasattr(g, "_login_user"):
+            delattr(g, "_login_user")
+        auth_data = Client.make_authorization(
+            www_authenticate, admin_uri, _USERNAME, _PASSWORD + "2")
+        response = super(Client, self.client).get(admin_uri, auth=auth_data)
+        self.assertEqual(response.status_code, 401)
+        www_authenticate = response.www_authenticate
+        self.assertEqual(www_authenticate.stale, False)
+        self.assertEqual(www_authenticate.opaque, opaque)
+
+        if hasattr(g, "_login_user"):
+            delattr(g, "_login_user")
+        auth_data = Client.make_authorization(
+            www_authenticate, admin_uri, _USERNAME, _PASSWORD)
+        response = super(Client, self.client).get(admin_uri, auth=auth_data)
+        self.assertEqual(response.status_code, 200)
+
+    def test_logout(self) -> None:
+        """Tests the logging out.
+
+        :return: None.
+        """
+        if not self.has_flask_login:
+            self.skipTest("Skipped without Flask-Login.")
+
+        admin_uri: str = self.app.url_for("admin-1")
+        logout_uri: str = self.app.url_for("logout")
+        response: Response
+
+        response = self.client.get(admin_uri)
+        self.assertEqual(response.status_code, 401)
+
+        response = self.client.get(admin_uri,
+                                   digest_auth=(_USERNAME, _PASSWORD))
+        self.assertEqual(response.status_code, 200)
+
+        response = self.client.get(admin_uri)
+        self.assertEqual(response.status_code, 200)
+
+        response = self.client.post(logout_uri, data={"next": admin_uri})
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.location, admin_uri)
+
+        response = self.client.get(admin_uri)
+        self.assertEqual(response.status_code, 401)
+
+        response = self.client.get(admin_uri,
+                                   digest_auth=(_USERNAME, _PASSWORD))
+        self.assertEqual(response.status_code, 401)
+
+        response = self.client.get(admin_uri,
+                                   digest_auth=(_USERNAME, _PASSWORD))
+        self.assertEqual(response.status_code, 200)
+
+        response = self.client.get(admin_uri)
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(self.user.visits, 2)