Working start of an OAuth flow

5 files changed, 206 insertions, 0 deletions

diff --git a/api/views/__init__.py b/api/views/__init__.py
new file mode 100644
index 0000000..d661e7c
--- /dev/null
+++ b/api/views/__init__.py
@@ -0,0 +1,3 @@
+from .apps import *  # noqa
+from .base import api  # noqa
+from .instance import *  # noqa
diff --git a/api/views/apps.py b/api/views/apps.py
new file mode 100644
index 0000000..33ecf0f
--- /dev/null
+++ b/api/views/apps.py
@@ -0,0 +1,37 @@
+import secrets
+
+from ninja import Field, Schema
+
+from ..models import Application
+from .base import api
+
+
+class CreateApplicationSchema(Schema):
+    client_name: str
+    redirect_uris: str
+    scopes: None | str = None
+    website: None | str = None
+
+
+class ApplicationSchema(Schema):
+    id: str
+    name: str
+    website: str | None
+    client_id: str
+    client_secret: str
+    redirect_uri: str = Field(alias="redirect_uris")
+
+
+@api.post("/v1/apps", response=ApplicationSchema)
+def add_app(request, details: CreateApplicationSchema):
+    client_id = "tk-" + secrets.token_urlsafe(16)
+    client_secret = secrets.token_urlsafe(40)
+    application = Application.objects.create(
+        name=details.client_name,
+        website=details.website,
+        client_id=client_id,
+        client_secret=client_secret,
+        redirect_uris=details.redirect_uris,
+        scopes=details.scopes or "read",
+    )
+    return application
diff --git a/api/views/base.py b/api/views/base.py
new file mode 100644
index 0000000..e9a087d
--- /dev/null
+++ b/api/views/base.py
@@ -0,0 +1,5 @@
+from ninja import NinjaAPI
+
+from api.parser import FormOrJsonParser
+
+api = NinjaAPI(parser=FormOrJsonParser())
diff --git a/api/views/instance.py b/api/views/instance.py
new file mode 100644
index 0000000..5923d30
--- /dev/null
+++ b/api/views/instance.py
@@ -0,0 +1,56 @@
+from django.conf import settings
+
+from activities.models import Post
+from core.models import Config
+from takahe import __version__
+from users.models import Domain, Identity
+
+from .base import api
+
+
+@api.get("/v1/instance")
+@api.get("/v1/instance/")
+def instance_info(request):
+    return {
+        "uri": request.headers.get("host", settings.SETUP.MAIN_DOMAIN),
+        "title": Config.system.site_name,
+        "short_description": "",
+        "description": "",
+        "email": "",
+        "version": __version__,
+        "urls": {},
+        "stats": {
+            "user_count": Identity.objects.filter(local=True).count(),
+            "status_count": Post.objects.filter(local=True).count(),
+            "domain_count": Domain.objects.count(),
+        },
+        "thumbnail": Config.system.site_banner,
+        "languages": ["en"],
+        "registrations": (
+            Config.system.signup_allowed and not Config.system.signup_invite_only
+        ),
+        "approval_required": False,
+        "invites_enabled": False,
+        "configuration": {
+            "accounts": {},
+            "statuses": {
+                "max_characters": Config.system.post_length,
+                "max_media_attachments": 4,
+                "characters_reserved_per_url": 23,
+            },
+            "media_attachments": {
+                "supported_mime_types": [
+                    "image/apng",
+                    "image/avif",
+                    "image/gif",
+                    "image/jpeg",
+                    "image/png",
+                    "image/webp",
+                ],
+                "image_size_limit": (1024**2) * 10,
+                "image_matrix_limit": 2000 * 2000,
+            },
+        },
+        "contact_account": None,
+        "rules": [],
+    }
diff --git a/api/views/oauth.py b/api/views/oauth.py
new file mode 100644
index 0000000..6be2778
--- /dev/null
+++ b/api/views/oauth.py
@@ -0,0 +1,105 @@
+import secrets
+from urllib.parse import urlparse
+
+from django.contrib.auth.mixins import LoginRequiredMixin
+from django.http import HttpResponseRedirect, JsonResponse
+from django.utils.decorators import method_decorator
+from django.views.decorators.csrf import csrf_exempt
+from django.views.generic import TemplateView, View
+
+from api.models import Application, Token
+
+
+class OauthRedirect(HttpResponseRedirect):
+    def __init__(self, redirect_uri, key, value):
+        self.allowed_schemes = [urlparse(redirect_uri).scheme]
+        super().__init__(redirect_uri + f"?{key}={value}")
+
+
+class AuthorizationView(LoginRequiredMixin, TemplateView):
+    """
+    Asks the user to authorize access.
+
+    Could maybe be a FormView, but things are weird enough we just handle the
+    POST manually.
+    """
+
+    template_name = "api/oauth_authorize.html"
+
+    def get_context_data(self):
+        redirect_uri = self.request.GET["redirect_uri"]
+        scope = self.request.GET.get("scope", "read")
+        try:
+            application = Application.objects.get(
+                client_id=self.request.GET["client_id"]
+            )
+        except (Application.DoesNotExist, KeyError):
+            return OauthRedirect(redirect_uri, "error", "invalid_application")
+        return {
+            "application": application,
+            "redirect_uri": redirect_uri,
+            "scope": scope,
+            "identities": self.request.user.identities.all(),
+        }
+
+    def post(self, request):
+        # Grab the application and other details again
+        redirect_uri = self.request.POST["redirect_uri"]
+        scope = self.request.POST["scope"]
+        application = Application.objects.get(client_id=self.request.POST["client_id"])
+        # Get the identity
+        identity = self.request.user.identities.get(pk=self.request.POST["identity"])
+        # Make a token
+        token = Token.objects.create(
+            application=application,
+            user=self.request.user,
+            identity=identity,
+            token=secrets.token_urlsafe(32),
+            code=secrets.token_urlsafe(16),
+            scopes=scope.split(),
+        )
+        # Redirect with the token's code
+        return OauthRedirect(redirect_uri, "code", token.code)
+
+
+@method_decorator(csrf_exempt, name="dispatch")
+class TokenView(View):
+    def post(self, request):
+        grant_type = request.POST["grant_type"]
+        scopes = set(self.request.POST.get("scope", "read").split())
+        try:
+            application = Application.objects.get(
+                client_id=self.request.POST["client_id"]
+            )
+        except (Application.DoesNotExist, KeyError):
+            return JsonResponse({"error": "invalid_client_id"}, status=400)
+        # TODO: Implement client credentials flow
+        if grant_type == "client_credentials":
+            return JsonResponse({"error": "invalid_grant_type"}, status=400)
+        elif grant_type == "authorization_code":
+            code = request.POST["code"]
+            # Retrieve the token by code
+            # TODO: Check code expiry based on created date
+            try:
+                token = Token.objects.get(code=code, application=application)
+            except Token.DoesNotExist:
+                return JsonResponse({"error": "invalid_code"}, status=400)
+            # Verify the scopes match the token
+            if scopes != set(token.scopes):
+                return JsonResponse({"error": "invalid_scope"}, status=400)
+            # Update the token to remove its code
+            token.code = None
+            token.save()
+            # Return them the token
+            return JsonResponse(
+                {
+                    "access_token": token.token,
+                    "token_type": "Bearer",
+                    "scope": " ".join(token.scopes),
+                    "created_at": int(token.created.timestamp()),
+                }
+            )
+
+
+class RevokeTokenView(View):
+    pass