restructure

src/activity.ts

@@ -1,79 +1,52 @@
-import { Sha256Signer } from "activitypub-http-signatures";
+import { readFileSync } from "node:fs";
-import { createHash } from "node:crypto";
 import { Article } from "./article.js";
-import { User } from "./user.js";
+import { User, getByActor } from "./user.js";
-import { readFileSync } from "fs";
 import { fillRoute } from "./router.js";
+import { streamToString, hashDigest } from "./util.js";
+import { signedFetch } from "./net.js";
 
 export const CONTEXT = "https://www.w3.org/ns/activitystreams";
 export const PUBLIC = CONTEXT + "#Public";
+export const TYPE = "application/activity+json";
 
-const hasher = createHash("sha256");
+export const handleInboxPost = async (req: Request) => {
+    try {
+        if (!req.body) {
+            console.warn("no body");
+            return;
+        }
 
-const hashDigest =(payload: string | Buffer) =>
+        const body = await streamToString(req.body);
-    "sha-256="
+        let activity: Record<string, any>;
-    + hasher
+        try {
-        .update((Buffer.isBuffer(payload) ? payload : Buffer.from(payload)).toString("hex"))
+            activity = JSON.parse(body);
-        .digest("base64");
+        }
+        catch (e) {
+            console.warn("body json parse failed");
+            return;
+        }
 
-const flattenHeaders = (headers: Record<string, string>) =>
+        if (activity.type === "Follow") {
-    Object.entries(headers).map(([key, value]) => `${key}: ${value}`);
+            const actor = await getByActor(activity.object);
 
-interface SignedInit {
+            if (actor) {
-    keyId: string;
+                const follower = activity.actor;
-    privateKey: string;
+            }
-    digest?: string;
+            else {
-};
+                console.warn("follow attempt on unknown user");
-
+            }
-export const signedFetch = async (url: string, init: RequestInit, signedInit: SignedInit) => {
+        }
-    const signedHeaders: HeadersInit = [
+        else if (activity.type === "Undo") {
-        ["Date", new Date().toUTCString()],
+
-        ["Host", new URL(url).host],
+        }
-        ["Content-Type",  `application/ld+json; profile="${CONTEXT}"`]
+        else {
-    ];
+            console.warn("unsupported activity type");
-
+        }
-    if (signedInit.digest) {
+    }
-        signedHeaders.push(["Digest", signedInit.digest]);
+    finally { }
-    }
-    else if (init.body) {
-        if (Buffer.isBuffer(init.body) || typeof init.body === "string") {
-            signedHeaders.push(["Digest", hashDigest(init.body)]);
-        }
-        else throw "unsupported body type";
-    }
-
-    const signer = new Sha256Signer({
-        privateKey: signedInit.privateKey,
-        publicKeyId: signedInit.keyId
-    });
-
-    const signature = signer.sign({
-        url,
-        method: init.method as string,
-        headers: signedHeaders
-    });
-
-    signedHeaders.push(["Signature", signature]);
-
-    const newHeaders = new Headers();
-    if (Array.isArray(init.headers)) {
-        for (const header of init.headers) {
-            if (Array.isArray(header))
-                newHeaders.set(header[0], header[1]);
-            else throw "unsupported headers type"; // Lazy.
-        }
-
-        for (const [key, value] of signedHeaders) {
-            newHeaders.set(key, value);
-        }
-
-        init.headers = newHeaders;
-    }
-    else throw "unsupported headers type"; // Lazy.
-
-    return fetch(url, init);
 };
 
+/*
 export const sendActivity = async (publicKeyId: string, privateKey: string, activity: string, hash: string, inbox: string) => {
     const headers: Record<string, string> = {
         date: new Date().toUTCString(),
@@ -97,6 +70,7 @@ export const sendActivity = async (publicKeyId: string, privateKey: string, acti
         body: activity
     });
 };
+*/
 
 export const deleteArticleActivity = (article: Article, user: User) => {
     const actor = fillRoute("actor", user.nickname);
@@ -182,3 +156,25 @@ export const orderedCollection = (id: string, orderedItems: (string | Record<str
     id,
     orderedItems
 });
+
+export const userToPerson = (user: User) => {
+    const id = fillRoute("actor", user.nickname);
+
+    return {
+        id,
+        type: "Person",
+        "@context": CONTEXT,
+        discoverable: true,
+        preferredUsername: user.nickname,
+        name: user.name,
+        summary: user.bio,
+        url: id,
+        inbox: fillRoute("inbox", user.nickname),
+        outbox: fillRoute("outbox", user.nickname),
+        publicKey: {
+            id: + "#main-key",
+            owner: id,
+            publicKeyPem: user.public_key
+        }
+    };
+};

src/index.ts

@@ -1,10 +1,10 @@
-import { readFileSync } from "fs";
 import express from "express";
 import ActivitypubExpress from "activitypub-express";
 import { get as getOutbox } from "./outbox.js";
 import { get as getUserByNickname, getId as getUserId } from "./user.js";
-import { Routes, fillRoute } from "./router.js";
+import { Routes } from "./router.js";
-import { getBySlug } from "./article.js";
+import { getBySlug as getArticleBySlug } from "./article.js";
+import { userToPerson, TYPE as ACTIVITYPUB_TYPE } from "./activity.js";
 
 const port = parseInt(process.env.port || "8080");
 const app = express();
@@ -42,7 +42,7 @@ app.get(Routes.outbox, async (req, res) => {
   const userId = await getUserId(req.params.actor);
   if (userId) {
     const body = await getOutbox(userId).then((out) => JSON.stringify(out, null, 4));
-    res.append("Content-Type", "application/activity+json");
+    res.append("Content-Type", ACTIVITYPUB_TYPE);
     res.send(body);
   }
   else {
@@ -56,28 +56,11 @@ app.get(Routes.actor, async (req, res) => {
 
   if (actor) {
     const accept = req.headers["accept"] || "";
-    if (accept.startsWith("application/activity+json")) {
+    if (accept.includes(ACTIVITYPUB_TYPE)) {
-      const id = fillRoute("actor", nickname);
+      const obj = userToPerson(actor);
-      const obj = {
-        id,
-        type: "Person",
-        "@context": "https://www.w3.org/ns/activitystreams",
-        discoverable: true,
-        preferredUsername: actor.nickname,
-        name: actor.name,
-        summary: actor.bio,
-        url: id,
-        inbox: fillRoute("inbox", actor.nickname),
-        outbox: fillRoute("outbox", actor.nickname),
-        publicKey: {
-          id: id + "#main-key",
-          owner: id,
-          publicKeyPem: actor.public_key
-        }
-      };
       const body = JSON.stringify(obj, null, 4);
 
-      res.append("Content-Type", "application/activity+json");
+      res.set("Content-Type", ACTIVITYPUB_TYPE);
       res.send(body);
     }
     else {
@@ -91,7 +74,7 @@ app.get(Routes.actor, async (req, res) => {
 });
 
 app.get("/:slug.html", async (req, res) => {
-  const article = await getBySlug(req.params.slug);
+  const article = await getArticleBySlug(req.params.slug);
 
   if (!article || article.deleted) {
     res.status(404).send("not found");
@@ -103,7 +86,7 @@ app.get("/:slug.html", async (req, res) => {
 });
 
 app.get("/:slug.md", async (req, res) => {
-  const article = await getBySlug(req.params.slug);
+  const article = await getArticleBySlug(req.params.slug);
 
   if (!article || article.deleted) {
     res.status(404).send("not found");

src/net.ts

@@ -0,0 +1,61 @@
+import { CONTEXT } from "./activity.js";
+import { hashDigest } from "./util.js";
+import { Sha256Signer } from "activitypub-http-signatures";
+
+export const flattenHeaders = (headers: Record<string, string>) =>
+    Object.entries(headers).map(([key, value]) => `${key}: ${value}`);
+
+export interface SignedInit {
+    keyId: string;
+    privateKey: string;
+    digest?: string;
+};
+
+export const signedFetch = async (url: string, init: RequestInit, signedInit: SignedInit) => {
+    const signedHeaders: HeadersInit = [
+        ["Date", new Date().toUTCString()],
+        ["Host", new URL(url).host],
+        ["Content-Type", `application/ld+json; profile="${CONTEXT}"`]
+    ];
+
+    if (signedInit.digest) {
+        signedHeaders.push(["Digest", signedInit.digest]);
+    }
+    else if (init.body) {
+        if (Buffer.isBuffer(init.body) || typeof init.body === "string") {
+            signedHeaders.push(["Digest", hashDigest(init.body)]);
+        }
+        else throw "unsupported body type";
+    }
+
+    const signer = new Sha256Signer({
+        privateKey: signedInit.privateKey,
+        publicKeyId: signedInit.keyId
+    });
+
+    const signature = signer.sign({
+        url,
+        method: init.method as string,
+        headers: signedHeaders
+    });
+
+    signedHeaders.push(["Signature", signature]);
+
+    const newHeaders = new Headers();
+    if (Array.isArray(init.headers)) {
+        for (const header of init.headers) {
+            if (Array.isArray(header))
+                newHeaders.set(header[0], header[1]);
+            else throw "unsupported headers type"; // Lazy.
+        }
+
+        for (const [key, value] of signedHeaders) {
+            newHeaders.set(key, value);
+        }
+
+        init.headers = newHeaders;
+    }
+    else throw "unsupported headers type"; // Lazy.
+
+    return fetch(url, init);
+};

src/user.ts

@@ -2,6 +2,7 @@ import { generateKeyPair } from "node:crypto";
 import { z } from "zod";
 import db from "./db.js";
 import { getFollowers } from "./collection.js";
+import { fillRoute } from "./router.js";
 
 export const nicknameRegex = /^[a-zA-Z0-9_]+$/;
 
@@ -25,6 +26,17 @@ export const get = async (nickname: string) =>
         .first()
     ;
 
+const EXTRACT_NICKNAME = new RegExp("/" + fillRoute("actor", "(.+)").replaceAll("/", "\\/") + "/");
+
+export const getByActor = async (actor: string) => {
+    const matchArray = actor.match(EXTRACT_NICKNAME);
+    if (matchArray) {
+        const nickname = matchArray[1];
+        return get(nickname);
+    }
+    else return null;
+};
+
 export const getNickname = async (userId: number): Promise<string | null> =>
     db("users")
         .select("nickname")

src/util.ts

@@ -0,0 +1,14 @@
+import { createHash } from "node:crypto";
+
+const hasher = createHash("sha256");
+
+export const hashDigest = (payload: string | Buffer) =>
+    "sha-256="
+    + hasher
+        .update((Buffer.isBuffer(payload) ? payload : Buffer.from(payload)).toString("hex"))
+        .digest("base64");
+
+export const streamToString = async (stream: ReadableStream<Uint8Array>) => {
+    const arr = new Uint8Array(await new Response(stream).arrayBuffer());
+    return new TextDecoder("utf-8").decode(arr);
+};