Cache actors

lib/activitypub/activity.ts

@@ -41,8 +41,13 @@ export interface Delete extends Activity {
 
 export interface Actor {
 	id: string;
+	name: string;
 	inbox: string;
+	endpoints?: {
+		sharedInbox?: string;
+	}
 	publicKey: {
 		publicKeyPem: string;
 	};
+	icon: string | object | (string | object)[];
 }

lib/activitypub/actor.ts

@@ -12,7 +12,7 @@ export default async function actor(router: Router) {
 		],
 		"type": "Person",
 		"id": `https://${domain}/ap/actor`,
-		"preferredUsername": "shadowfacts",
+		"preferredUsername": "blog",
 		"name": "shadowfacts' blog",
 		"icon": {
 			"type": "Image",

lib/activitypub/federate.ts

@@ -24,7 +24,59 @@ function createActivity(article: Article): Create {
 	return createObject;
 }
 
-export async function fetchActor(url: string): Promise<Actor> {
+export async function getActor(url: string, db: Database, forceUpdate: boolean = false): Promise<Actor> {
+	if (forceUpdate) {
+		try {
+			const cached = await getCachedActor(url, db);
+			if (cached) return cached;
+		} catch (err) {
+			console.error(`Encountered error getting cached actor ${url}`, err);
+		}
+	}
+	const remote = await fetchActor(url);
+	cacheActor(remote, db);
+	return remote;
+}
+
+export async function getCachedActor(url: string, db: Database): Promise<Actor> {
+	return new Promise((resolve, reject) => {
+		db.get("SELECT * FROM actors WHERE id = $id", {
+			$id: url
+		}, (err, result) => {
+			if (err) {
+				reject(err);
+			} else {
+				resolve({
+					id: result.id,
+					name: result.display_name,
+					inbox: result.inbox,
+					icon: result.icon_url,
+					publicKey: {
+						publicKeyPem: result.public_key_pem
+					}
+				} as Actor);
+			}
+		});
+	});
+}
+
+async function cacheActor(actor: Actor, db: Database) {
+	function getIconUrl(icon: string | object): string {
+		return icon instanceof String ? icon : (icon as any).url;
+	}
+	const iconUrl: string = actor.icon instanceof Array ? getIconUrl(actor.icon[0]) : getIconUrl(actor.icon);
+	db.run("INSERT OR REPLACE INTO actors(id, display_name, inbox, icon_url, public_key_pem) VALUES($id, $display_name, $inbox, $icon_url, $public_key_pem)", {
+		$id: actor.id,
+		$display_name: actor.name,
+		$inbox: actor.inbox,
+		$icon_url: iconUrl,
+		$public_key_pem: actor.publicKey.publicKeyPem
+	}, (err) => {
+		if (err) console.error(`Encountered error caching actor ${actor.id}`, err);
+	});
+}
+
+async function fetchActor(url: string): Promise<Actor> {
 	return new Promise((resolve, reject) => {
 		request({
 			url,
@@ -35,7 +87,7 @@ export async function fetchActor(url: string): Promise<Actor> {
 			json: true
 		}, (err, res) => {
 			if (err) reject(err);
-			else resolve(<Actor>res.body);
+			else resolve(res.body as Actor);
 		});
 	});
 }
@@ -74,6 +126,7 @@ export async function signAndSend(activity: Activity, inbox: string) {
 }
 
 async function sendToFollowers(activity: Create, db: Database) {
+	// TODO: only send to unique inboxes
 	db.each("SELECT inbox FROM followers", (err, result) => {
 		if (err) {
 			console.log("Error getting followers: ", err);

lib/activitypub/inbox.ts

@@ -1,6 +1,6 @@
 import { Router, Request, Response } from "express";
 import uuidv4 from "uuid/v4";
-import { fetchActor, signAndSend } from "./federate";
+import { getActor, signAndSend } from "./federate";
 import { Activity, Follow, Accept, Undo, Create, Note, Delete } from "./activity";
 import { Database } from "sqlite3";
 import { URL } from "url";
@@ -39,7 +39,8 @@ async function handleFollow(activity: Activity, req: Request, res: Response) {
 		res.end();
 		return;
 	}
-	const actor = await fetchActor(follow.actor);
+	const db = req.app.get("db") as Database;
+	const actor = await getActor(follow.actor, db, true); // always force re-fetch the actor on follow
 	const acceptObject = <Accept>{
 		"@context": [
 			"https://www.w3.org/ns/activitystreams",
@@ -51,8 +52,8 @@ async function handleFollow(activity: Activity, req: Request, res: Response) {
 		"object": follow
 	};
 	signAndSend(acceptObject, actor.inbox);
-	const db = req.app.get("db") as Database;
-	const serverInbox = new URL("/inbox", actor.inbox).toString();
+	// prefer shared server inbox
+	const serverInbox = actor.endpoints && actor.endpoints.sharedInbox ? actor.endpoints.sharedInbox : actor.inbox;
 	db.run("INSERT OR IGNORE INTO followers(id, inbox) VALUES($id, $inbox)", {
 		$id: actor.id,
 		$inbox: serverInbox
@@ -87,6 +88,7 @@ function sanitizeStatus(content: string): string {
 async function handleCreateNote(create: Create, req: Request, res: Response) {
 	const note = create.object as Note;
 	const db = req.app.get("db") as Database;
+	getActor(note.attributedTo, db); // get and cache the actor if it's not already cached
 	const sanitizedContent = sanitizeStatus(note.content);
 	db.run("INSERT OR IGNORE INTO notes(id, content, attributed_to, in_reply_to, conversation, published) VALUES($id, $content, $attributed_to, $in_reply_to, $conversation, $published)", {
 		$id: note.id,

lib/activitypub/middleware/http-signature.ts

@@ -1,20 +1,28 @@
 import crypto, { createVerify } from "crypto";
 import { Request, Response, NextFunction } from "express";
-import { fetchActor } from "../federate";
+import { getActor } from "../federate";
 import { IncomingHttpHeaders } from "http";
+import { Database } from "sqlite3";
 
 export = async (req: Request, res: Response, next: NextFunction) => {
 	if (req.method !== "POST") {
 		next();
 		return;
 	}
-	const actor = await fetchActor(req.body.actor as string);
+	const db = req.app.get("db") as Database;
+	const actor = await getActor(req.body.actor as string, db);
+	if (validate(req, actor.publicKey.publicKeyPem)) {
+		next();
+	} else {
+		// if the first check fails, force re-fetch the actor and try again
+		const actor = await getActor(req.body.actor as string, db, true);
 		if (validate(req, actor.publicKey.publicKeyPem)) {
 			next();
 		} else {
 			console.log(`Could not validate HTTP signature for ${req.body.actor}`);
 			res.status(401).end("Could not validate HTTP signature");
 		}
+	}
 };
 
 function validate(req: Request, publicKeyPem: string): boolean {

lib/index.ts

@@ -14,6 +14,7 @@ const db = new (sqlite3.verbose().Database)(process.env.DB_PATH!);
 db.run("CREATE TABLE IF NOT EXISTS followers (id TEXT PRIMARY KEY, inbox TEXT)");
 db.run("CREATE TABLE IF NOT EXISTS articles (id TEXT PRIMARY KEY, article_doc TEXT, conversation TEXT, has_federated INT)");
 db.run("CREATE TABLE IF NOT EXISTS notes (id TEXT PRIMARY KEY, content TEXT, attributed_to TEXT, in_reply_to TEXT, conversation TEXT, published TEXT)");
+db.run("CREATE TABLE IF NOT EXISTS actors (id TEXT PRIMARY KEY, display_name TEXT, inbox TEXT, icon_url TEXT, public_key_pem TEXT)")
 
 async function generate(): Promise<Page[]> {
 	generators.copy();