Working start of an OAuth flow

14 files changed, 392 insertions, 0 deletions

diff --git a/api/__init__.py b/api/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/api/__init__.py
diff --git a/api/admin.py b/api/admin.py
new file mode 100644
index 0000000..072abb0
--- /dev/null
+++ b/api/admin.py
@@ -0,0 +1,13 @@
+from django.contrib import admin
+
+from api.models import Application, Token
+
+
+@admin.register(Application)
+class ApplicationAdmin(admin.ModelAdmin):
+    list_display = ["id", "name", "website", "created"]
+
+
+@admin.register(Token)
+class TokenAdmin(admin.ModelAdmin):
+    list_display = ["id", "user", "application", "created"]
diff --git a/api/apps.py b/api/apps.py
new file mode 100644
index 0000000..878e7d5
--- /dev/null
+++ b/api/apps.py
@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class ApiConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "api"
diff --git a/api/migrations/0001_initial.py b/api/migrations/0001_initial.py
new file mode 100644
index 0000000..e9d37f3
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+++ b/api/migrations/0001_initial.py
@@ -0,0 +1,87 @@
+# Generated by Django 4.1.3 on 2022-12-11 03:39
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ("users", "0003_identity_followers_etc"),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="Application",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("client_id", models.CharField(max_length=500)),
+                ("client_secret", models.CharField(max_length=500)),
+                ("redirect_uris", models.TextField()),
+                ("scopes", models.TextField()),
+                ("name", models.CharField(max_length=500)),
+                ("website", models.CharField(blank=True, max_length=500, null=True)),
+                ("created", models.DateTimeField(auto_now_add=True)),
+                ("updated", models.DateTimeField(auto_now=True)),
+            ],
+        ),
+        migrations.CreateModel(
+            name="Token",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("token", models.CharField(max_length=500)),
+                ("code", models.CharField(blank=True, max_length=100, null=True)),
+                ("scopes", models.JSONField()),
+                ("created", models.DateTimeField(auto_now_add=True)),
+                ("updated", models.DateTimeField(auto_now=True)),
+                (
+                    "application",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="tokens",
+                        to="api.application",
+                    ),
+                ),
+                (
+                    "identity",
+                    models.ForeignKey(
+                        blank=True,
+                        null=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="tokens",
+                        to="users.identity",
+                    ),
+                ),
+                (
+                    "user",
+                    models.ForeignKey(
+                        blank=True,
+                        null=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="tokens",
+                        to=settings.AUTH_USER_MODEL,
+                    ),
+                ),
+            ],
+        ),
+    ]
diff --git a/api/migrations/__init__.py b/api/migrations/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/api/migrations/__init__.py
diff --git a/api/models/__init__.py b/api/models/__init__.py
new file mode 100644
index 0000000..663cd7e
--- /dev/null
+++ b/api/models/__init__.py
@@ -0,0 +1,2 @@
+from .application import Application  # noqa
+from .token import Token  # noqa
diff --git a/api/models/application.py b/api/models/application.py
new file mode 100644
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--- /dev/null
+++ b/api/models/application.py
@@ -0,0 +1,19 @@
+from django.db import models
+
+
+class Application(models.Model):
+    """
+    OAuth applications
+    """
+
+    client_id = models.CharField(max_length=500)
+    client_secret = models.CharField(max_length=500)
+
+    redirect_uris = models.TextField()
+    scopes = models.TextField()
+
+    name = models.CharField(max_length=500)
+    website = models.CharField(max_length=500, blank=True, null=True)
+
+    created = models.DateTimeField(auto_now_add=True)
+    updated = models.DateTimeField(auto_now=True)
diff --git a/api/models/token.py b/api/models/token.py
new file mode 100644
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--- /dev/null
+++ b/api/models/token.py
@@ -0,0 +1,39 @@
+from django.db import models
+
+
+class Token(models.Model):
+    """
+    An (access) token to call the API with.
+
+    Can be either tied to a user, or app-level only.
+    """
+
+    application = models.ForeignKey(
+        "api.Application",
+        on_delete=models.CASCADE,
+        related_name="tokens",
+    )
+
+    user = models.ForeignKey(
+        "users.User",
+        blank=True,
+        null=True,
+        on_delete=models.CASCADE,
+        related_name="tokens",
+    )
+
+    identity = models.ForeignKey(
+        "users.Identity",
+        blank=True,
+        null=True,
+        on_delete=models.CASCADE,
+        related_name="tokens",
+    )
+
+    token = models.CharField(max_length=500)
+    code = models.CharField(max_length=100, blank=True, null=True)
+
+    scopes = models.JSONField()
+
+    created = models.DateTimeField(auto_now_add=True)
+    updated = models.DateTimeField(auto_now=True)
diff --git a/api/parser.py b/api/parser.py
new file mode 100644
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--- /dev/null
+++ b/api/parser.py
@@ -0,0 +1,20 @@
+import json
+
+from ninja.parser import Parser
+
+
+class FormOrJsonParser(Parser):
+    """
+    If there's form data in a request, makes it into a JSON dict.
+    This is needed as the Mastodon API allows form data OR json body as input.
+    """
+
+    def parse_body(self, request):
+        # Did they submit JSON?
+        if request.content_type == "application/json":
+            return json.loads(request.body)
+        # Fall back to form data
+        value = {}
+        for key, item in request.POST.items():
+            value[key] = item
+        return value
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