Merge pull request #145 from blunomy/feature/oidc

Feature/OIDC

Author: alexcjohnson

Diff for: .circleci/config.yml

@@ -1,7 +1,7 @@
 version: 2.1
 
 orbs:
-  browser-tools: circleci/[email protected].6
+  browser-tools: circleci/[email protected].8
 
 jobs:
   python-38: &test-template

Diff for: CHANGELOG.md

@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+### Added
+- OIDCAuth allows to authenticate via OIDC
+- BasicAuth saves the current user in the session
+- Ability to define user groups in BasicAuth
+- Group-based permission and protection functions
+
 ## [2.2.1] - 2024-03-01
 ### Fixed
 - Fix when looking for callback inputs that are not in the right format when checking for whitelisted routes

Diff for: README.md

@@ -157,4 +157,155 @@ def layout(user_id: str):
         html.H1(f"User {user_id} (authenticated only)"),
         html.Div("Members-only information"),
     ]
-```
+```
+
+### OIDC Authentication
+
+To add authentication with OpenID Connect, you will first need to set up an OpenID Connect provider (IDP).
+This typically requires creating
+* An application in your IDP
+* Defining the redirect URI for your application, for testing locally you can use http://localhost:8050/oidc/callback
+* A client ID and secret for the application
+
+Once you have set up your IDP, you can add it to your Dash app as follows:
+
+```python
+from dash import Dash
+from dash_auth import OIDCAuth
+
+app = Dash(__name__)
+
+auth = OIDCAuth(app, secret_key="aStaticSecretKey!")
+auth.register_provider(
+    "idp",
+    token_endpoint_auth_method="client_secret_post",
+    # Replace the below values with your own
+    # NOTE: Do not hardcode your client secret!
+    client_id="<my-client-id>",
+    client_secret="<my-client-secret>",
+    server_metadata_url="<my-idp-.well-known-configuration>",
+)
+```
+
+Once this is done, connecting to your app will automatically redirect to the IDP login page.
+
+#### Multiple OIDC Providers
+
+For multiple OIDC providers, you can use `register_provider` to add new ones after the OIDCAuth has been instantiated.
+
+```python
+from dash import Dash, html
+from dash_auth import OIDCAuth
+from flask import request, redirect, url_for
+
+app = Dash(__name__)
+
+app.layout = html.Div([
+    html.Div("Hello world!"),
+    html.A("Logout", href="/oidc/logout"),
+])
+
+auth = OIDCAuth(
+    app,
+    secret_key="aStaticSecretKey!",
+    # Set the route at which the user will select the IDP they wish to login with
+    idp_selection_route="/login",
+)
+auth.register_provider(
+    "IDP 1",
+    token_endpoint_auth_method="client_secret_post",
+    client_id="<my-client-id>",
+    client_secret="<my-client-secret>",
+    server_metadata_url="<my-idp-.well-known-configuration>",
+)
+auth.register_provider(
+    "IDP 2",
+    token_endpoint_auth_method="client_secret_post",
+    client_id="<my-client-id2>",
+    client_secret="<my-client-secret2>",
+    server_metadata_url="<my-idp2-.well-known-configuration>",
+)
+
+@app.server.route("/login", methods=["GET", "POST"])
+def login_handler():
+    if request.method == "POST":
+        idp = request.form.get("idp")
+    else:
+        idp = request.args.get("idp")
+
+    if idp is not None:
+        return redirect(url_for("oidc_login", idp=idp))
+
+    return """<div>
+        <form>
+            <div>How do you wish to sign in:</div>
+            <select name="idp">
+                <option value="IDP 1">IDP 1</option>
+                <option value="IDP 2">IDP 2</option>
+            </select>
+            <input type="submit" value="Login">
+        </form>
+    </div>"""
+
+
+if __name__ == "__main__":
+    app.run_server(debug=True)
+```
+
+### User-group-based permissions
+
+`dash_auth` provides a convenient way to secure parts of your app based on user groups.
+
+The following utilities are defined:
+* `list_groups`: Returns the groups of the current user, or None if the user is not authenticated.
+* `check_groups`: Checks the current user groups against the provided list of groups.
+  Available group checks are `one_of`, `all_of` and `none_of`.
+  The function returns None if the user is not authenticated.
+* `protected`: A function decorator that modifies the output if the user is unauthenticated
+  or missing group permission.
+* `protected_callback`: A callback that only runs if the user is authenticated
+  and with the right group permissions.
+
+NOTE: user info is stored in the session so make sure you define a secret_key on the Flask server
+to use this feature.
+
+If you wish to use this feature with BasicAuth, you will need to define the groups for individual
+basicauth users:
+
+```python
+from dash_auth import BasicAuth
+
+app = Dash(__name__)
+USER_PWD = {
+    "username": "password",
+    "user2": "useSomethingMoreSecurePlease",
+}
+BasicAuth(
+    app,
+    USER_PWD,
+    user_groups={"user1": ["group1", "group2"], "user2": ["group2"]},
+    secret_key="Test!",
+)
+
+# You can also use a function to get user groups
+def check_user(username, password):
+    if username == "user1" and password == "password":
+        return True
+    if username == "user2" and password == "useSomethingMoreSecurePlease":
+        return True
+    return False
+
+def get_user_groups(user):
+    if user == "user1":
+        return ["group1", "group2"]
+    elif user == "user2":
+        return ["group2"]
+    return []
+
+BasicAuth(
+    app,
+    auth_func=check_user,
+    user_groups=get_user_groups,
+    secret_key="Test!",
+)
+```

Diff for: dash_auth/__init__.py

@@ -1,6 +1,25 @@
 from .public_routes import add_public_routes, public_callback
 from .basic_auth import BasicAuth
+from .group_protection import (
+    list_groups, check_groups, protected, protected_callback
+)
+# oidc auth requires authlib, install with `pip install dash-auth[oidc]`
+try:
+    from .oidc_auth import OIDCAuth, get_oauth
+except ModuleNotFoundError:
+    pass
 from .version import __version__
 
 
-__all__ = ["add_public_routes", "public_callback", "BasicAuth", "__version__"]
+__all__ = [
+    "add_public_routes",
+    "check_groups",
+    "list_groups",
+    "get_oauth",
+    "protected",
+    "protected_callback",
+    "public_callback",
+    "BasicAuth",
+    "OIDCAuth",
+    "__version__",
+]

Diff for: dash_auth/auth.py

@@ -83,22 +83,10 @@ def before_request_auth():
             # Otherwise, ask the user to log in
             return self.login_request()
 
-    def is_authorized_hook(self, func):
-        self._auth_hooks.append(func)
-        return func
-
     @abstractmethod
     def is_authorized(self):
         pass
 
-    @abstractmethod
-    def auth_wrapper(self, f):
-        pass
-
-    @abstractmethod
-    def index_auth_wrapper(self, f):
-        pass
-
     @abstractmethod
     def login_request(self):
         pass

Diff for: dash_auth/basic_auth.py

@@ -1,10 +1,13 @@
 import base64
-from typing import Optional, Union, Callable
+import logging
+from typing import Dict, List, Optional, Union, Callable
 import flask
 from dash import Dash
 
 from .auth import Auth
 
+UserGroups = Dict[str, List[str]]
+
 
 class BasicAuth(Auth):
     def __init__(
@@ -13,6 +16,10 @@ def __init__(
         username_password_list: Union[list, dict] = None,
         auth_func: Callable = None,
         public_routes: Optional[list] = None,
+        user_groups: Optional[
+            Union[UserGroups, Callable[[str], UserGroups]]
+        ] = None,
+        secret_key: str = None
     ):
         """Add basic authentication to Dash.
 
@@ -24,9 +31,28 @@ def __init__(
             boolean (True if the user has access otherwise False).
         :param public_routes: list of public routes, routes should follow the
             Flask route syntax
+        :param user_groups: a dict or a function returning a dict
+            Optional group for each user, allowing to protect routes and
+            callbacks depending on user groups
+        :param secret_key: Flask secret key
+            A string to protect the Flask session, by default None.
+            It is required if you need to store the current user
+            in the session.
+            Generate a secret key in your Python session
+            with the following commands:
+            >>> import os
+            >>> import base64
+            >>> base64.b64encode(os.urandom(30)).decode('utf-8')
+            Note that you should not do this dynamically:
+            you should create a key and then assign the value of
+            that key in your code.
         """
-        Auth.__init__(self, app, public_routes=public_routes)
+        super().__init__(app, public_routes=public_routes)
         self._auth_func = auth_func
+        self._user_groups = user_groups
+        if secret_key is not None:
+            app.server.secret_key = secret_key
+
         if self._auth_func is not None:
             if username_password_list is not None:
                 raise ValueError(
@@ -54,35 +80,35 @@ def is_authorized(self):
         username_password = base64.b64decode(header.split('Basic ')[1])
         username_password_utf8 = username_password.decode('utf-8')
         username, password = username_password_utf8.split(':', 1)
+        authorized = False
         if self._auth_func is not None:
             try:
-                return self._auth_func(username, password)
-            except Exception as e:
-                print(e)
+                authorized = self._auth_func(username, password)
+            except Exception:
+                logging.exception("Error in authorization function.")
                 return False
         else:
-            return self._users.get(username) == password
+            authorized = self._users.get(username) == password
+        if authorized:
+            try:
+                flask.session["user"] = {"email": username, "groups": []}
+                if callable(self._user_groups):
+                    flask.session["user"]["groups"] = self._user_groups(
+                        username
+                    )
+                elif self._user_groups:
+                    flask.session["user"]["groups"] = self._user_groups.get(
+                        username, []
+                    )
+            except RuntimeError:
+                logging.warning(
+                    "Session is not available. Have you set a secret key?"
+                )
+        return authorized
 
     def login_request(self):
         return flask.Response(
             'Login Required',
             headers={'WWW-Authenticate': 'Basic realm="User Visible Realm"'},
             status=401
         )
-
-    def auth_wrapper(self, f):
-        def wrap(*args, **kwargs):
-            if not self.is_authorized():
-                return flask.Response(status=403)
-
-            response = f(*args, **kwargs)
-            return response
-        return wrap
-
-    def index_auth_wrapper(self, original_index):
-        def wrap(*args, **kwargs):
-            if self.is_authorized():
-                return original_index(*args, **kwargs)
-            else:
-                return self.login_request()
-        return wrap