Added master_doc to conf.py.

.gitignore

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

README.rst

@@ -343,7 +343,7 @@ 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.
@@ -359,10 +359,13 @@ Writing Tests
 =============
 
 You can write tests with our test client that handles HTTP Digest
-Authentication.  Example for a unittest testcase:
+Authentication.
+
+Example for 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
@@ -385,6 +388,41 @@ Authentication.  Example for a unittest testcase:
             self.assertEqual(response.status_code, 200)
 
 
+
+Example for 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
+
+.. _unittest: https://docs.python.org/3/library/unittest.html
+.. _pytest: https://pytest.org
+
+
 Copyright
 =========
 
@@ -402,6 +440,7 @@ Copyright
  See the License for the specific language governing permissions and
  limitations under the License.
 
+
 Authors
 =======
 

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/source/conf.py

@@ -0,0 +1,58 @@
+# 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 = '0.2.1'
+
+
+# -- 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']
+
+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 +1,24 @@
+.. 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!
+=============================================
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contents:
+
+   intro
+   flask_digest_auth
+   examples
+
+
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`

docs/source/intro.rst

@@ -0,0 +1,109 @@
+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`_.
+
+See :ref:`example-alone-simple` and :ref:`example-alone-large`.
+
+
+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.
+
+See :ref:`example-flask-login-simple` and
+:ref:`example-flask-login-large`.
+
+
+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.
+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`.
+
+
+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
+
+
+.. _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 = 0.2.0
+version = 0.2.1
 author = imacat
 author_email = imacat@mail.imacat.idv.tw
 description = The Flask HTTP Digest Authentication project.

src/flask_digest_auth/algo.py

@@ -23,8 +23,6 @@ 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.
@@ -49,67 +47,53 @@ 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

@@ -24,59 +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 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.
-        """
 
 
 class DigestAuth:
@@ -104,13 +58,44 @@ class DigestAuth:
     def login_required(self, view) -> t.Callable:
         """The view decorator for HTTP digest authentication.
 
-        :param view:
+        :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.
@@ -120,36 +105,24 @@ 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
-                    user = self.__get_user(authorization.username)
-                    g.user = user
-                    self.__on_login(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)
+                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
 
@@ -199,16 +172,27 @@ class DigestAuth:
             raise UnauthorizedException("Invalid nonce")
 
     def make_response_header(self, state: AuthState) -> str:
-        """Composes and returns the WWW-Authenticate response header.
+        """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:
@@ -371,3 +355,52 @@ 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

@@ -36,8 +36,8 @@ class Client(WerkzeugClient):
         """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.
         """
@@ -59,16 +59,15 @@ class Client(WerkzeugClient):
                            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

@@ -35,14 +35,15 @@ _PASSWORD: str = "Circle Of Life"
 class User:
     """A dummy user"""
 
-    def __init__(self, username: str, password_hash: str):
+    def __init__(self, username: str, password: str):
         """Constructs a dummy user.
 
         :param username: The username.
-        :param password_hash: The password hash.
+        :param password: The clear-text password.
         """
         self.username: str = username
-        self.password_hash: str = password_hash
+        self.password_hash: str = make_password_hash(
+            _REALM, username, password)
         self.visits: int = 0
 
 
@@ -63,9 +64,8 @@ class AuthenticationTestCase(TestCase):
 
         auth: DigestAuth = DigestAuth(realm=_REALM)
         auth.init_app(app)
-        user_db: t.Dict[str, User] \
-            = {_USERNAME: User(
-                   _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]:
@@ -141,7 +141,7 @@ class AuthenticationTestCase(TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.data.decode("UTF-8"),
                          f"Hello, {_USERNAME}! #2")
-        self.assertEqual(g.user.visits, 1)
+        self.assertEqual(self.user.visits, 1)
 
     def test_stale_opaque(self) -> None:
         """Tests the stale and opaque value.
@@ -218,4 +218,4 @@ class AuthenticationTestCase(TestCase):
 
         response = self.client.get(admin_uri)
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(g.user.visits, 2)
+        self.assertEqual(self.user.visits, 2)

tests/test_flask_login.py

@@ -21,7 +21,6 @@
 import typing as t
 from secrets import token_urlsafe
 
-import flask_login
 from flask import Response, Flask, g, redirect, request
 from flask_testing import TestCase
 from werkzeug.datastructures import WWWAuthenticate, Authorization
@@ -36,14 +35,15 @@ _PASSWORD: str = "Circle Of Life"
 class User:
     """A dummy user."""
 
-    def __init__(self, username: str, password_hash: str):
+    def __init__(self, username: str, password: str):
         """Constructs a dummy user.
 
         :param username: The username.
-        :param password_hash: The password hash.
+        :param password: The clear-text password.
         """
         self.username: str = username
-        self.password_hash: str = password_hash
+        self.password_hash: str = make_password_hash(
+            _REALM, username, password)
         self.visits: int = 0
         self.is_authenticated: bool = True
         self.is_active: bool = True
@@ -86,9 +86,8 @@ class FlaskLoginTestCase(TestCase):
         auth: DigestAuth = DigestAuth(realm=_REALM)
         auth.init_app(app)
 
-        user_db: t.Dict[str, User] \
-            = {_USERNAME: User(
-                   _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]:
@@ -154,7 +153,7 @@ 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("admin-1"))
         self.assertEqual(response.status_code, 401)
@@ -167,7 +166,7 @@ class FlaskLoginTestCase(TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(response.data.decode("UTF-8"),
                          f"Hello, {_USERNAME}! #2")
-        self.assertEqual(flask_login.current_user.visits, 1)
+        self.assertEqual(self.user.visits, 1)
 
     def test_stale_opaque(self) -> None:
         """Tests the stale and opaque value.
@@ -175,7 +174,7 @@ 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.")
 
         admin_uri: str = self.app.url_for("admin-1")
         response: Response
@@ -222,6 +221,9 @@ class FlaskLoginTestCase(TestCase):
 
         :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
@@ -253,4 +255,4 @@ class FlaskLoginTestCase(TestCase):
 
         response = self.client.get(admin_uri)
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(flask_login.current_user.visits, 2)
+        self.assertEqual(self.user.visits, 2)