Implement ACLs

pyproject.toml

@@ -19,6 +19,7 @@ pyyaml = "^6.0.2"
 nanoid = "^2.0.0"
 # grung-db = {git = "https://git.evilchi.li/evilchili/grung-db.git"}
 grung-db = {git = "file:///home/greg/dev/grung-db/"}
+flask-session = "^0.8.0"
 
 [tool.poetry.group.dev.dependencies]
 pytest = "*"

src/ttfrog/app.py

@@ -5,8 +5,8 @@ from types import SimpleNamespace
 
 from dotenv import dotenv_values
 from flask import Flask
+from flask_session import Session
 from grung.db import GrungDB
-from grung.exceptions import UniqueConstraintError
 from tinydb.storages import MemoryStorage
 
 from ttfrog import schema
@@ -78,6 +78,7 @@ VIEW_URI=/
             config=config_file,
             data_root=data_root,
             database=data_root / f"{self.config.NAME}.json",
+            sessions=data_root / "session_cache",
         )
 
     def initialize(self, db: GrungDB = None, force: bool = False) -> None:
@@ -85,7 +86,9 @@ VIEW_URI=/
         Instantiate both the database and the flask application.
         """
         if force or not self._initialized:
-            if self.config.IN_MEMORY_DB:
+            if db:
+                self.db = db
+            elif self.config.IN_MEMORY_DB:
                 self.db = GrungDB.with_schema(schema, storage=MemoryStorage)
             else:
                 self.db = GrungDB.with_schema(
@@ -98,6 +101,10 @@ VIEW_URI=/
             self.web.config["SECRET_KEY"] = self.config.SECRET_KEY
             self.web.config["SEND_FILE_MAX_AGE_DEFAULT"] = 0
             self.web.config["DEBUG"] = True
+            self.web.config["SESSION_TYPE"] = "filesystem"
+            self.web.config["SESSION_REFRESH_EACH_REQUEST"] = True
+            self.web.config["SESSION_FILE_DIR"] = self.path.sessions
+            Session(self.web)
 
             self._initialized = True
 
@@ -128,11 +135,28 @@ VIEW_URI=/
         self.add_member(npcs, sabetha)
         self.add_member(npcs, johns)
 
+        guest = self.add_member(users, schema.User(name="guest"))
+
         # create the admin user and admins group
-        admin = self.add_member(users, schema.User(name=self.config.ADMIN_USERNAME, email=self.config.ADMIN_EMAIL))
+        admin = self.add_member(
+            users, schema.User(name=self.config.ADMIN_USERNAME, password="fnord", email=self.config.ADMIN_EMAIL)
+        )
         admins = self.db.save(schema.Group(name="administrators"))
         admins = self.add_member(groups, admins)
-        self.add_member(admins, admin)
+        admin = self.add_member(admins, admin)
+
+        groups.set_permissions(admins, permissions=[
+            schema.Permissions.READ,
+            schema.Permissions.WRITE,
+            schema.Permissions.DELETE
+        ], db=self.db)
+
+        users.set_permissions(admins, permissions=[
+            schema.Permissions.READ,
+            schema.Permissions.WRITE,
+            schema.Permissions.DELETE
+        ], db=self.db)
+
 
 
 sys.modules[__name__] = ApplicationContext()

src/ttfrog/forms.py

@@ -1,6 +1,7 @@
 from dataclasses import dataclass, field
 from functools import cached_property
 
+from flask import g
 from grung.types import BackReference, Collection, Pointer, Record
 
 from ttfrog import schema
@@ -13,6 +14,7 @@ class Form:
     """
     The base Form controller for the web UI.
     """
+
     record: Record
     data: field(default_factory=dict)
 
@@ -24,12 +26,12 @@ class Form:
 
     def prepare(self):
         for key, value in self.data.items():
-
             # filter out fields that cannot be set by the user
             if key in self.read_only:
                 continue
 
             self.record[key] = value
+        self.record.author = g.user
         return self.record
 
 
@@ -38,6 +40,7 @@ class Page(Form):
     """
     A form for creating and updating Page records.
     """
+
     record: schema.Page
 
     @cached_property
@@ -50,6 +53,7 @@ class NPC(Page):
     """
     A form for creating and updating Page records.
     """
+
     record: schema.NPC
 
 
@@ -58,6 +62,7 @@ class User(Page):
     """
     A form for creating and updating Page records.
     """
+
     record: schema.NPC
 
 
@@ -66,4 +71,5 @@ class Group(Page):
     """
     A form for creating and updating Page records.
     """
+
     record: schema.NPC

src/ttfrog/schema.py

@@ -1,5 +1,10 @@
+from __future__ import annotations
 
-from grung.types import BackReference, Collection, Field, Record, Pointer
+from datetime import datetime
+from typing import List
+
+from grung.types import BackReference, Collection, DateTime, Field, Password, Pointer, Record, Timestamp
+from tinydb import Query
 
 
 class Page(Record):
@@ -18,7 +23,9 @@ class Page(Record):
             Collection("members", Page),  # The pages that exist below this page's URI
             BackReference("parent", value_type=Page),  # The page that exists above this page's URI
             Pointer("author", value_type=User),  # The last user to touch the page.
-            # DateTime("last_modified"),                 # The last time the page was modified.
+            DateTime("created"),  # When the page was created
+            Timestamp("last_modified"),  # The last time the page was modified.
+            Collection("acl", Permissions),
         ]
 
     def before_insert(self, db):
@@ -29,6 +36,10 @@ class Page(Record):
         """
         super().before_insert(db)
 
+        now = datetime.utcnow()
+        if not self.doc_id and self.created < now:
+            self.created = now
+
         if not self.name and not self.title:
             raise Exception("Must provide either a name or a title!")
         if not self.name:
@@ -44,7 +55,7 @@ class Page(Record):
         correct URI. This ensures that if a page is moved from one collection to another, the URI is updated.
         """
         super().after_insert(db)
-        if not hasattr(self, 'members'):
+        if not hasattr(self, "members"):
             return
         for child in self.members:
             obj = BackReference.dereference(child, db)
@@ -57,24 +68,62 @@ class Page(Record):
                 return page
         return None
 
+    def set_permissions(self, entity: Entity, permissions: List, db) -> Record:
+        perms = db.save(Permissions(entity=entity, grants="".join(permissions)))
+        self.acl = [entry for entry in self.acl if entry.entity != entity] + [perms]
+        self = db.save(self)
+        return perms
 
-class User(Page):
+
+class Entity(Page):
+    def has_permission(self, record: Record, requested: str, db) -> bool:
+
+        # if there's no ACL at all, the record is world-readable.
+        if not getattr(record, "acl", None):
+            return requested == Permissions.READ
+
+        # Use the grant specific to this entity, if there is one
+        for entry in record.acl:
+            if entry.entity.uid == self.uid:
+                return requested in entry.grants
+
+        for group in db.Group.search(Query()["members"].any([self.reference])):
+            if group.has_permission(record, requested, db):
+                return True
+        return False
+
+    def can_read(self, record: Record, db):
+        return self.has_permission(record, Permissions.READ, db)
+
+    def can_write(self, record: Record, db):
+        return self.has_permission(record, Permissions.WRITE, db)
+
+    def can_delete(self, record: Record, db):
+        return self.has_permission(record, Permissions.DELETE, db)
+
+
+class User(Entity):
     """
     A website user, editable as a wiki page.
     """
 
+    def check_credentials(self, username: str, password: str) -> bool:
+        return username == self.name and self._metadata.fields["password"].compare(password, self.password)
+
     @classmethod
     def fields(cls):
         return [
             field
             for field in [
                 *super().fields(),
-                Field("email", unique=True)
-            ] if field.name != "members"
+                Field("email", unique=True),
+                Password("password"),
+            ]
+            if field.name != "members"
         ]
 
 
-class Group(Page):
+class Group(Entity):
     """
     A set of users, editable as a wiki page.
     """
@@ -84,3 +133,13 @@ class NPC(Page):
     """
     An NPC, editable as a wiki page.
     """
+
+
+class Permissions(Record):
+    READ = "r"
+    WRITE = "w"
+    DELETE = "d"
+
+    @classmethod
+    def fields(cls):
+        return [*super().fields(), Pointer("entity", Entity), Field("grants")]

src/ttfrog/themes/default/base.html

@@ -16,15 +16,22 @@
         <span>&nbsp; / <a href="{{ app.config.VIEW_URI }}{{ uri }}">{{ name }}</a></span>
         {% endfor %}
     </nav>
+    {% if session['user_id'] == 1 %}
+    Welcome, {{ user['name'] }}. [ <a href="{{ url_for('login') }}">LOGIN</a> ]
+    {% else %}
+    Welcome, <a href="{{ url_for('User/' + user['name']) }}">{{ user['name'] }}</a>.
+    {% endif %}
     <nav>
         Menu: 
         <ul>
             {% block menu %}{% endblock %}
         </ul>
     </nav>
+    Last Edited By: {{ page.author.name }}
+    <br>
 
     <main>
-        {% for message in get_flashed_messages() %}
+        {% for message in g.messages %}
         <div class="alert">
             {{ message }}
         </div>

src/ttfrog/web.py

@@ -1,7 +1,7 @@
-from flask import Response, render_template, request
+from flask import Response, g, redirect, render_template, request, session, url_for
 from tinydb import where
 
-from ttfrog import app, schema, forms
+from ttfrog import app, forms, schema
 
 STATIC = ["static"]
 
@@ -16,11 +16,11 @@ def relative_uri(path: str = ""):
 
 def get_parent(table: str, uri: str):
     try:
-        parent_uri = uri.strip("/").split("/", -1)[0]
+        parent_uri = uri.strip("/").rsplit("/", 1)[0]
     except IndexError:
         return None
 
-    return get_page(parent_uri, table=table if '/' in parent_uri else 'Page', create_okay=False)
+    return get_page(parent_uri, table=table if "/" in parent_uri else "Page", create_okay=False)
 
 
 def get_page(path: str = "", table: str = "Page", create_okay: bool = False):
@@ -32,20 +32,28 @@ def get_page(path: str = "", table: str = "Page", create_okay: bool = False):
     if table not in app.db.tables():
         return None
 
-    matches = app.db.table(table).search(where("uri") == uri, recurse=False)
-    if not matches:
+    page = app.db.table(table).get(where("uri") == uri, recurse=False)
+    if hasattr(page, "acl"):
+        acl = []
+        for pointer in page.acl:
+            table, uid = pointer.split("::")
+            acl += app.db.table(table).search(where("uid") == uid, recurse=False)
+        page.acl = acl
+
+    if not page:
         if not create_okay:
             return None
-        return getattr(schema, table)(
-            name=uri.split("/")[-1],
-            body="This page does not exist",
         parent = get_parent(table, uri)
-        )
-    page = matches[0]
+        if not g.user.can_read(parent, app.db):
+            return None
+        return getattr(schema, table)(name=uri.split("/")[-1], body="This page does not exist", parent=parent)
 
-    if hasattr(page, 'members'):
+    if not g.user.can_read(page, app.db):
+        return None
+
+    if hasattr(page, "members"):
         subpages = []
-        for pointer in matches[0].members:
+        for pointer in page.members:
             table, uid = pointer.split("::")
             subpages += app.db.table(table).search(where("uid") == uid, recurse=False)
         page.members = subpages
@@ -56,7 +64,7 @@ def get_page(path: str = "", table: str = "Page", create_okay: bool = False):
 def rendered(page: schema.Record, template: str = "page.html"):
     if not page:
         return Response("Page not found", status=404)
-    return render_template(template, page=page, app=app, breadcrumbs=breadcrumbs())
+    return render_template(template, page=page, app=app, breadcrumbs=breadcrumbs(), user=session['user'], g=g)
 
 
 def get_static(path):
@@ -81,19 +89,62 @@ def index():
     return rendered(get_page(create_okay=False))
 
 
+def do_login(username: str, password: str) -> bool:
+    """
+    Update the session with the user record if the credenteials are valid.
+    """
+    if not (username and password):
+        return False
+
+    user = app.db.User.get(where("name") == "username")
+    if not user:
+        return False
+
+    if not user.check_credentials(username, password):
+        return False
+
+    app.web.logger.debug(f"Session for {user.name} ({user.doc_id}) started.")
+    g.user = user
+    session["user_id"] = g.user.doc_id
+    session["user"] = dict(g.user.serialize())
+    return True
+
+
+@app.web.route("/login", methods=["GET", "POST"])
+def login():
+    app.web.session_interface.regenerate(session)
+
+    if request.method == "POST":
+        username = request.form.get("username")
+        password = request.form.get("password")
+        if do_login(username, password):
+            return redirect(url_for("index"))
+        g.messages.append(f"Invalid login for {username}")
+    return rendered(schema.Page(name="Login", title="Please enter your login details"), "login.html")
+
+
+@app.web.route("/logout")
+def logout():
+    if "user_id" in session:
+        del session["user_id"]
+    del g.user
+
+
 @app.web.route(f"{app.config.VIEW_URI}/<path:table>/<path:path>", methods=["GET"])
-@app.web.route(f"{app.config.VIEW_URI}/<path:path>", methods=["GET"], defaults={'table': 'Page'})
+@app.web.route(f"{app.config.VIEW_URI}/<path:path>", methods=["GET"], defaults={"table": "Page"})
 def view(table, path):
-    return rendered(get_page(request.path, table=table, create_okay=True))
+    parent = get_parent(table, relative_uri())
+    print(parent)
+    return rendered(get_page(request.path, table=table, create_okay=(parent and parent.doc_id is not None)))
 
 
 @app.web.route(f"{app.config.VIEW_URI}/<path:table>/<path:path>", methods=["POST"])
-@app.web.route(f"{app.config.VIEW_URI}/<path:path>", methods=["POST"], defaults={'table': 'Page'})
+@app.web.route(f"{app.config.VIEW_URI}/<path:path>", methods=["POST"], defaults={"table": "Page"})
 def edit(table, path):
     uri = relative_uri()
     parent = get_parent(table, uri)
     if not parent:
-        return Response(f"Parent for {uri} does not exist.", status=403)
+        return Response("You cannot create a page at this location.", status=403)
 
     # get or create the docoument at this uri
     page = get_page(uri, table=table, create_okay=True)
@@ -109,6 +160,15 @@ def edit(table, path):
     return rendered(app.add_member(parent, save_data))
 
 
+@app.web.before_request
+def before_request():
+    g.messages = []
+    user_id = session.get("user_id", 1)
+    g.user = app.db.User.get(doc_id=user_id)
+    session["user_id"] = user_id
+    session["user"] = dict(g.user.serialize())
+
+
 @app.web.after_request
 def add_header(r):
     r.headers["Cache-Control"] = "no-cache, no-store, must-revalidate, public, max-age=0"

test/test_db.py

@@ -2,18 +2,21 @@ import pytest
 
 import ttfrog.app
 from ttfrog import schema
+from grung.db import GrungDB
+from tinydb.storages import MemoryStorage
 
 
 @pytest.fixture
 def app():
+    fixture_db = GrungDB.with_schema(schema, storage=MemoryStorage)
     ttfrog.app.load_config(defaults=None, IN_MEMORY_DB=1)
-    ttfrog.app.initialize()
+    ttfrog.app.initialize(db=fixture_db, force=True)
     yield ttfrog.app
-    ttfrog.app.db.close()
+    ttfrog.app.db.truncate()
 
 
 def test_create(app):
-    user = schema.User(name="john", email="john@foo")
+    user = schema.User(name="john", email="john@foo", password="powerfulCat")
     assert user.uid
     assert user._metadata.fields["uid"].unique
 
@@ -34,7 +37,29 @@ def test_create(app):
     assert after_update == john_something
     assert before_update != after_update
 
-    players = schema.Group(name="players", users=[john_something])
-    players = app.db.save(players)
-    players.users[0]["name"] = "fnord"
-    app.db.save(players)
+
+def test_permissions(app):
+    john = app.db.save(schema.User(name="john", email="john@foo", password="powerfulCat"))
+    players = app.db.save(schema.Group(name="players", members=[john]))
+    notes = app.db.save(schema.Page(name="notes"))
+
+    # default read-only
+    assert players.can_read(notes, app.db)
+    assert not players.can_write(notes, app.db)
+    assert not players.can_delete(notes, app.db)
+
+    # set to rw, no delete
+    notes.set_permissions(players, [schema.Permissions.READ, schema.Permissions.WRITE], app.db)
+    assert players.can_read(notes, app.db)
+    assert players.can_write(notes, app.db)
+    assert not players.can_delete(notes, app.db)
+
+    # members of the group inherit group permissions
+    assert john.can_read(notes, app.db)
+    assert john.can_write(notes, app.db)
+    assert not john.can_delete(notes, app.db)
+
+    # permissions are the union of user + group permissions
+    notes.set_permissions(john, [schema.Permissions.DELETE], app.db)
+    assert not players.can_delete(notes, app.db)
+    assert john.can_delete(notes, app.db)