From 401efee7cb54c0ac9d9b5fbe16d8962cbf05a345 Mon Sep 17 00:00:00 2001
From: Andrew Pietila <a.pietila@protonmail.com>
Date: Tue, 28 Mar 2023 23:32:02 -0500
Subject: [PATCH] Add basic instance actor, along with rudimentary http
 signature key generation support.

---
 lib/keys.js                        | 49 ++++++++++++++++++++++++++++++
 migrations/20230324060224_inbox.js |  2 ++
 migrations/20230329035124_keys.js  | 25 +++++++++++++++
 routes/actor.js                    | 41 +++++++++++++++++++++++++
 4 files changed, 117 insertions(+)
 create mode 100644 lib/keys.js
 create mode 100644 migrations/20230329035124_keys.js
 create mode 100644 routes/actor.js

diff --git a/lib/keys.js b/lib/keys.js
new file mode 100644
index 0000000..5edb6f5
--- /dev/null
+++ b/lib/keys.js
@@ -0,0 +1,49 @@
+'use strict';
+
+const crypto = require('crypto');
+const db = require('./db');
+
+var generateKeyPair = (type, options) => {
+    return new Promise((res, rej) => {
+        crypto.generateKeyPair(type, options, (err, pubkey, privkey) => {
+            if ( err != null ) {
+                rej(err);
+            } else {
+                res({publicKey: pubkey, privateKey: privkey});
+            }
+        });
+    });
+};
+
+var getKeyPair = async (actor) => {
+    var result = await db('keys').where({actor}).andWhere('expiry', '>', (new Date()).getTime()/1000);
+    if ( result.length != 0 ) {
+        return {
+            publicKey: result[0].public,
+            privateKey: result[0].private
+        };
+    } else {
+        var {publicKey, privateKey} = await generateKeyPair('rsa', {
+            modulusLength: 4096,
+            publicKeyEncoding: {
+                format: 'pem'
+            },
+            privateKeyEncoding: {
+                format: 'pem'
+            }
+        });
+        await db('keys').insert({
+            expiry: (new Date().setDate(new Date().getDate()+7).getTime()/1000),
+            public: publicKey,
+            private: privateKey,
+            actor: actor
+        });
+        return {
+            publicKey, privateKey
+        };
+    }
+};
+
+module.exports = {
+    getKeyPair
+};
diff --git a/migrations/20230324060224_inbox.js b/migrations/20230324060224_inbox.js
index 48e1c5d..bc912cb 100644
--- a/migrations/20230324060224_inbox.js
+++ b/migrations/20230324060224_inbox.js
@@ -1,3 +1,5 @@
+/* eslint-disable jsdoc/valid-types */
+// eslint doesn't seem to understand, but vscode does.
 'use strict';
 
 /**
diff --git a/migrations/20230329035124_keys.js b/migrations/20230329035124_keys.js
new file mode 100644
index 0000000..0f63fdf
--- /dev/null
+++ b/migrations/20230329035124_keys.js
@@ -0,0 +1,25 @@
+/* eslint-disable jsdoc/valid-types */
+// eslint doesn't seem to understand, but vscode does.
+'use strict';
+
+/**
+ * @param { import("knex").Knex } knex
+ * @returns { Promise<void> }
+ */
+exports.up = function(knex) {
+    return knex.schema.createTable('keys', (table) => {
+        table.increments('id');
+        table.integer('expiry');
+        table.string('private');
+        table.string('public');
+        table.text('actor');
+    });
+};
+
+/**
+ * @param { import("knex").Knex } knex
+ * @returns { Promise<void> }
+ */
+exports.down = function(knex) {
+    return knex.schema.dropTable('keys');
+};
diff --git a/routes/actor.js b/routes/actor.js
new file mode 100644
index 0000000..7813bf3
--- /dev/null
+++ b/routes/actor.js
@@ -0,0 +1,41 @@
+'use strict';
+
+const express = require('express');
+const { getKeyPair } = require('../lib/keys');
+
+module.exports = {
+    /**
+     * @param {express.IRoute} routeObj
+     */
+    route: (routeObj) => {
+        routeObj.get((req, res, _next) => {
+            res.setHeader('content-type', 'application/activity+json');
+            res.json({
+                '@context': [
+                    'https://www.w3.org/ns/activitystreams',
+                    {
+                        security: 'https://w3id.org/security#'
+                    }
+                ],
+                'id': `https://${req.hostname}/actor`,
+                'type': 'Application',
+                'inbox': `https://${req.hostname}/actor/inbox`,
+                'security:publicKey': {
+                    'id': `https://${req.hostname}/actor#main-key`,
+                    'security:owner': {
+                        id: `https://${req.hostname}/actor`
+                    },
+                    'security:publicKeyPem': getKeyPair(`https://${req.hostname}/actor`)
+                },
+                'endpoints': {
+                    sharedInbox: `https://${req.hostname}/inbox`
+                },
+                'as:manuallyApprovesFollowers': true,
+                'outbox': `https://${req.hostname}/actor/outbox`,
+                'preferredUsername': '${req.hostname}',
+                'url': `https://${req.hostname}/about/more?instance_actor=true`
+            });
+            return res.end();
+        });
+    }
+};