Add fake db, properly deal with roles, improve types, etc

src/oidc-test/auth_utils.py

@@ -1,16 +1,16 @@
 from typing import Union
 from functools import wraps
 
-from fastapi import HTTPException, Request
+from fastapi import HTTPException, Request, status
 
 from .models import User
+from .database import db
 
 
 def get_current_user(request: Request) -> User:
-    auth_data = request.session.get("user")
-    if auth_data is None:
-        raise HTTPException(401, "Not authorized")
-    return User(**auth_data)
+    if (user_sub := request.session.get("user_sub")) is None:
+        raise HTTPException(status.HTTP_401_UNAUTHORIZED)
+    return db.get_user(user_sub)
 
 
 def get_current_user_or_none(request: Request) -> User | None:
@@ -20,11 +20,7 @@ def get_current_user_or_none(request: Request) -> User | None:
         return None
 
 
-def hasrole(
-    required_roles: Union[str, list[str]] = [],
-    roles_key: str = "roles",
-    realm: str | None = "realm_access",  # Keycloak standard for realm defined roles
-):
+def hasrole(required_roles: Union[str, list[str]] = []):
     required_roles_set: set[str]
     if isinstance(required_roles, str):
         required_roles_set = set([required_roles])
@@ -39,18 +35,9 @@ def hasrole(
                     500,
                     "Functions decorated with hasrole must have a request:Request argument",
                 )
-            if "user" not in request.session:
-                raise HTTPException(401, "Not authorized")
-            user = request.session["user"]
-            try:
-                if realm in user:
-                    roles = user[realm][roles_key]
-                else:
-                    roles = user[roles_key]
-            except KeyError:
-                raise HTTPException(401, "Not authorized")
-            if not any(required_roles_set.intersection(roles)):
-                raise HTTPException(401, "Not authorized")
+            user: User = get_current_user(request)
+            if not any(required_roles_set.intersection(user.roles_as_set)):
+                raise HTTPException(status.HTTP_401_UNAUTHORIZED)
             return await func(request, *args, **kwargs)
 
         return wrapper

src/oidc-test/database.py

@@ -0,0 +1,24 @@
+# Implement a fake in-memory database interface for demo purpose
+
+from authlib.integrations.starlette_client.apps import StarletteOAuth2App
+
+from .models import User
+
+
+class Database:
+    users: dict[str, User] = {}
+
+    # Last sessions for the user (key: users's subject id (sub))
+
+    async def add_user(
+        self, sub: str, user_info: dict, oidc_provider: StarletteOAuth2App
+    ) -> User:
+        user = User.from_auth(userinfo=user_info, oidc_provider=oidc_provider)
+        self.users[sub] = user
+        return user
+
+    def get_user(self, sub: str) -> User:
+        return self.users[sub]
+
+
+db = Database()

src/oidc-test/main.py

@@ -11,6 +11,7 @@ from authlib.integrations.starlette_client import OAuth, OAuthError
 from .settings import settings
 from .models import User
 from .auth_utils import hasrole, get_current_user_or_none, get_current_user
+from .database import db
 
 templates = Jinja2Templates("src/templates")
 
@@ -25,13 +26,15 @@ app.add_middleware(
     secret_key=settings.secret_key,
 )
 
-# Add oidc providers from the settings
+# Add oidc providers to authlib from the settings
 authlib_oauth = OAuth()
 for provider in settings.oidc.providers:
     authlib_oauth.register(
         name=provider.name,
         server_metadata_url=provider.provider_url,
-        client_kwargs={"scope": "openid email offline_access profile roles"},
+        client_kwargs={
+            "scope": "openid email offline_access profile roles",
+        },
         client_id=provider.client_id,
         client_secret=provider.client_secret,
         # client_id="some-client-id", # if enabled, authlib will also check that the access token belongs to this client id (audience)
@@ -40,38 +43,54 @@ for provider in settings.oidc.providers:
 
 @app.get("/login")
 async def login(request: Request, provider: str) -> RedirectResponse:
-    redirect_uri = request.url_for("auth", provider=provider)
+    redirect_uri = request.url_for("auth", oidc_provider_id=provider)
     try:
         provider_: StarletteOAuth2App = getattr(authlib_oauth, provider)
     except AttributeError:
-        raise HTTPException(500, "No such provider")
+        raise HTTPException(status.HTTP_401_UNAUTHORIZED, "No such provider")
     try:
         return await provider_.authorize_redirect(request, redirect_uri)
     except HTTPError:
         raise HTTPException(status.HTTP_401_UNAUTHORIZED, "Cannot reach provider")
 
 
-@app.get("/auth/{provider}")
-async def auth(request: Request, provider: str) -> RedirectResponse:
+@app.get("/auth/{oidc_provider_id}")
+async def auth(request: Request, oidc_provider_id: str) -> RedirectResponse:
     try:
-        provider_: StarletteOAuth2App = getattr(authlib_oauth, provider)
+        oidc_provider: StarletteOAuth2App = getattr(authlib_oauth, oidc_provider_id)
     except AttributeError:
-        raise HTTPException(500, "No such provider")
+        raise HTTPException(status.HTTP_401_UNAUTHORIZED, "No such provider")
     try:
-        token = await provider_.authorize_access_token(request)
+        token = await oidc_provider.authorize_access_token(request)
     except OAuthError as error:
-        raise HTTPException(status_code=401, detail=error.error)
-    user = token.get("userinfo")
-    if user:
-        request.session["user"] = dict(user)
+        raise HTTPException(status.HTTP_401_UNAUTHORIZED, detail=error.error)
+    # Remember the oidc_provider in the session
+    request.session["oidc_provider_id"] = oidc_provider_id
+    #
+    # One could process the full decoded token which contains extra information
+    # eg for updates. Here we are only interested in roles
+    #
+    if userinfo := token.get("userinfo"):
+        # sub given by oidc provider
+        sub = userinfo["sub"]
+        # Build and remember the user in the session
+        request.session["user_sub"] = sub
+        # Store the user in the database
+        await db.add_user(sub, user_info=userinfo, oidc_provider=oidc_provider)
         return RedirectResponse(url="/")
     else:
+        # Not sure if it's correct to redirect to plain login (which is not implemented anyway)
+        # if no userinfo is provided
         return RedirectResponse(url="/login")
 
 
 @app.get("/logout")
-async def logout(request: Request) -> RedirectResponse:
-    request.session.pop("user", None)
+async def logout(
+    request: Request, user: Annotated[User, Depends(get_current_user_or_none)]
+) -> RedirectResponse:
+    # TODO: logout from oidc_provider
+    # await user.oidc_provider.logout_redirect()
+    request.session.pop("user_sub", None)
     return RedirectResponse(url="/")
 
 
@@ -84,7 +103,6 @@ async def home(
         context={
             "settings": settings.model_dump(),
             "user": user,
-            "auth_data": request.session.get("user"),
         },
         name="index.html",
     )

src/oidc-test/models.py

@@ -1,11 +1,48 @@
-from pydantic import BaseModel, EmailStr, AnyHttpUrl
+from functools import cached_property
+from typing import Self
+
+from pydantic import BaseModel, EmailStr, AnyHttpUrl, Field, computed_field
+from authlib.integrations.starlette_client.apps import StarletteOAuth2App
 
 # from app.models import User
 
 
-class User(BaseModel, extra="ignore"):
+class Role(BaseModel, extra="ignore"):
+    name: str
+
+
+class UserBase(BaseModel, extra="ignore"):
 
     id: str | None = None
     name: str
     email: EmailStr | None = None
     picture: AnyHttpUrl | None = None
+    roles: list[Role] = []
+
+
+class User(UserBase):
+    class Config:
+        arbitrary_types_allowed = True
+
+    sub: str = Field(
+        description="""subject id of the user given by the oidc provider,
+                            also the key for the database 'table'""",
+    )
+    userinfo: dict = {}
+    oidc_provider: StarletteOAuth2App | None = None
+
+    @classmethod
+    def from_auth(cls, userinfo: dict, oidc_provider: StarletteOAuth2App) -> Self:
+        user = cls(**userinfo)
+        user.userinfo = userinfo
+        user.oidc_provider = oidc_provider
+        # Add roles if they are provided in the token
+        if raw_ra := userinfo.get("realm_access"):
+            if raw_roles := raw_ra.get("roles"):
+                user.roles = [Role(name=raw_role) for raw_role in raw_roles]
+        return user
+
+    @computed_field
+    @cached_property
+    def roles_as_set(self) -> set[str]:
+        return set([role.name for role in self.roles])

src/oidc-test/settings.py

@@ -15,7 +15,6 @@ class OIDCProvider(BaseModel):
     url: str = ""
     client_id: str = ""
     client_secret: str = ""
-    is_swagger: bool = False
 
     @computed_field
     @property
@@ -33,13 +32,6 @@ class OIDCSettings(BaseModel):
     providers: list[OIDCProvider] = []
     swagger_provider: str = ""
 
-    def get_swagger_provider(self) -> OIDCProvider:
-        for provider in self.providers:
-            if provider.is_swagger:
-                return provider
-        else:
-            raise UserWarning("Please define a provider for Swagger with id_swagger")
-
 
 class Settings(BaseSettings):
     """Settings wil be read from an .env file"""

src/templates/index.html

@@ -119,6 +119,10 @@
       .hasResponseStatus.status-401 {
         background-color: #ff000040;
       }
+      .role {
+        padding: 3px 6px;
+        background-color: #44228840;
+      }
     </style>
     <script>
     function checkHref(elem) {
@@ -143,10 +147,10 @@
     <h1>FastAPI test app for OIDC</h1>
     {% if not user %} 
     <div class="login-box">
-      <p>Not logged in</p>
+      <p>Log in with one of these authentication providers:</p>
       <div class="login-toolbox">
           {% for provider in settings.oidc.providers %}
-            <a href="login?provider={{ provider.name }}">Login with: {{ provider.name }}</a>
+            <a href="login?provider={{ provider.name }}">{{ provider.name }}</a>
           {% else %}
             <span class="error">Cannot login: no oidc prodiver in settings.yaml</span>
           {% endfor %}
@@ -159,7 +163,19 @@
         {% if user.picture %}
           <img src="{{ user.picture }}" class="picture"></img>
         {% endif %}
-        <p>{{ user.email }}</p>
+        <div>{{ user.email }}</div>
+        {% if user.roles %}
+          <div>
+          <span>Roles:</span>
+          {% for role in user.roles %}
+            <span class="role">{{ role.name }}</span>
+          {% endfor %}
+          </div>
+        {% endif %}
+        <div>
+          <span>Provider:</span>
+          {{ user.oidc_provider.name }} 
+        </div>
         <a href="logout" class="logout">Logout</a>
       </div>
     {% endif %}
@@ -180,7 +196,7 @@
       <div class="debug-auth">
         <p>Session details</p>
         <ul>
-          {% for key, value in auth_data.items() %}
+          {% for key, value in user.userinfo.items() %}
           <li>
             <span class="key">{{ key }}</span>: {{ value }}
           </li>