basic functionality, untested.

.gitignore

@@ -1 +1,2 @@
 node_modules
+*.build.js

README.md

@@ -9,7 +9,7 @@ It provides a `window.nostr` object which has the following methods:
 
 ```
 async window.nostr.getPublicKey(): string // returns your public key as hex
-async window.nostr.signEvent(event) // signs the given event in place
+async window.nostr.signEvent(event): string // returns the signature as hex
 ```
 
 ---

build.js

@@ -0,0 +1,26 @@
+#!/usr/bin/env node
+
+const esbuild = require('esbuild')
+const alias = require('esbuild-plugin-alias')
+
+esbuild.build({
+  bundle: true,
+  entryPoints: ['./extension/options.js'],
+  outfile: './extension/options.build.js',
+  plugins: [
+    alias({
+      stream: require.resolve('readable-stream')
+    })
+  ]
+})
+
+esbuild.build({
+  bundle: true,
+  entryPoints: ['./extension/background.js'],
+  outfile: './extension/background.build.js',
+  plugins: [
+    alias({
+      stream: require.resolve('readable-stream')
+    })
+  ]
+})

extension/background.js

@@ -1,9 +1,34 @@
-browser.runtime.onMessage.addListener((req, sender, reply) => {
-  switch (req.type) {
-    case 'getPublicKey':
-      reply({})
-      break
-    case 'signEvent':
+import browser from 'webextension-polyfill'
+import {validateEvent, signEvent, getPublicKey} from 'nostr-tools'
+
+browser.runtime.onMessage.addListener(async (req, sender, reply) => {
+  let {type, params, host} = req
+
+  try {
+    switch (type) {
+      case 'getPublicKey': {
+        let results = browser.storage.local.get('private_key')
+        if (results && results.private_key) {
+          reply(getPublicKey(results.private_key))
+        } else {
+          reply({error: 'no private key found'})
+        }
         break
       }
+      case 'signEvent': {
+        let {event} = params
+        if (!validateEvent(event)) return reply({error: 'invalid event'})
+
+        let results = browser.storage.local.get('private_key')
+        if (results && results.private_key) {
+          reply(signEvent(event, results.private_key))
+        } else {
+          reply({error: 'no private key found'})
+        }
+        break
+      }
+    }
+  } catch (error) {
+    reply({error})
+  }
 })

extension/content-script.js

@@ -6,19 +6,20 @@ document.head.appendChild(script)
 // listen for messages from that script
 window.addEventListener('message', async ev => {
   if (ev.source !== window) return
-  if (!ev.data || ev.data.ext !== 'nostr') {
+  if (!ev.data || ev.data.ext !== 'nos2x') {
     // pass on to background
-    var reply
+    var response
     try {
-      reply = browser.runtime.sendMessage({
-        ...ev.data,
+      response = browser.runtime.sendMessage({
+        type: ev.data.type,
+        params: ev.data.params,
         host: window.location.host
       })
     } catch (error) {
-      reply = {error}
+      response = {error}
     }
 
     // return response
-    window.postMessage({id: ev.data.id, reply})
+    window.postMessage({id: ev.data.id, ext: 'nos2x', response})
   }
 })

extension/manifest.json

@@ -3,15 +3,10 @@
   "description": "Nostr Signer Extension",
   "version": "0.0.1",
   "manifest_version": 2,
-  "icons": {
-    "16": "icons/icon-16x16.png",
-    "48": "icons/icon-48x48.png",
-    "128": "icons/icon-128x128.png"
-  },
   "options_page": "options.html",
   "background": {
     "scripts": [
-      "background.js"
+      "background.build.js"
     ],
     "persistent": false
   },

extension/nostr-provider.js

@@ -1,4 +1,45 @@
 window.nostr = {
-  getPublicKey() {},
-  signEvent(event) {}
+  _requests: {},
+  _pubkey: null,
+
+  async getPublicKey() {
+    if (this._pubkey) return this._pubkey
+    this._pubkey = await this._call('getPublicKey')
+    return this._pubkey
+  },
+
+  async signEvent(event) {
+    return this._call('signEvent', {event})
+  },
+
+  _call(type, params) {
+    return new Promise((resolve, reject) => {
+      let id = Math.random().toString().slice(4)
+      this._requests[id] = {resolve, reject}
+      window.postMessage(
+        {
+          id,
+          ext: 'nos2x',
+          type,
+          params
+        },
+        '*'
+      )
+    })
   }
+}
+
+window.addEventListener('message', message => {
+  if (
+    !message.data ||
+    message.data.ext !== 'nos2x' ||
+    !window.nostr._requests[message.data.id]
+  )
+    return
+
+  if (message.data.response.error) {
+    window.nostr._requests[message.data.id].reject(message.data.response.error)
+  } else {
+    window.nostr._requests[message.data.id].resolve(message.data.response)
+  }
+})

extension/options.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+
+<meta charset="utf-8" />
+<title>nos2x</title>
+
+<label>
+  Private Key:
+  <input id="privateKeyInput" />
+</label>
+
+<script src="options.build.js"></script>

extension/options.js

@@ -0,0 +1,15 @@
+/* global document */
+
+import browser from 'webextension-polyfill'
+
+document.getElementById('privateKeyInput').addEventListener('input', ev => {
+  browser.storage.local
+    .set({private_key: document.getElementById('privateKeyInput').value})
+    .then(() => {
+      console.log('success')
+    })
+})
+
+browser.storage.local.get('private_key').then(results => {
+  document.getElementById('privateKeyInput').value = results.private_key
+})

package.json

@@ -1,8 +1,11 @@
 {
   "dependencies": {
     "esbuild": "^0.14.11",
+    "esbuild-plugin-alias": "^0.2.1",
     "eslint": "^8.6.0",
+    "events": "^3.3.0",
     "nostr-tools": "^0.17.0",
-    "prettier": "^2.5.1"
+    "prettier": "^2.5.1",
+    "webextension-polyfill": "^0.8.0"
   }
 }

yarn.lock

@@ -367,6 +367,11 @@ esbuild-openbsd-64@0.14.11:
   resolved "https://registry.yarnpkg.com/esbuild-openbsd-64/-/esbuild-openbsd-64-0.14.11.tgz#caeff5f946f79a60ce7bcf88871ca4c71d3476e8"
   integrity sha512-l18TZDjmvwW6cDeR4fmizNoxndyDHamGOOAenwI4SOJbzlJmwfr0jUgjbaXCUuYVOA964siw+Ix+A+bhALWg8Q==
 
+esbuild-plugin-alias@^0.2.1:
+  version "0.2.1"
+  resolved "https://registry.yarnpkg.com/esbuild-plugin-alias/-/esbuild-plugin-alias-0.2.1.tgz#45a86cb941e20e7c2bc68a2bea53562172494fcb"
+  integrity sha512-jyfL/pwPqaFXyKnj8lP8iLk6Z0m099uXR45aSN8Av1XD4vhvQutxxPzgA2bTcAwQpa1zCXDcWOlhFgyP3GKqhQ==
+
 esbuild-sunos-64@0.14.11:
   version "0.14.11"
   resolved "https://registry.yarnpkg.com/esbuild-sunos-64/-/esbuild-sunos-64-0.14.11.tgz#90ce7e1749c2958a53509b4bae7b8f7d98f276d6"
@@ -518,6 +523,11 @@ esutils@^2.0.2:
   resolved "https://registry.yarnpkg.com/esutils/-/esutils-2.0.3.tgz#74d2eb4de0b8da1293711910d50775b9b710ef64"
   integrity sha512-kVscqXk4OCp68SZ0dkgEKVi6/8ij300KBWTJq32P/dYeWTSwK41WyTxalN1eRmA5Z9UU/LX9D7FWSmV9SAYx6g==
 
+events@^3.3.0:
+  version "3.3.0"
+  resolved "https://registry.yarnpkg.com/events/-/events-3.3.0.tgz#31a95ad0a924e2d2c419a813aeb2c4e878ea7400"
+  integrity sha512-mQw+2fkQbALzQ7V0MY0IqdnXNOeTtP4r0lN9z7AAawCXgqea7bDii20AYrIBrFd/Hx0M2Ocz6S111CaFkUcb0Q==
+
 evp_bytestokey@^1.0.0, evp_bytestokey@^1.0.3:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/evp_bytestokey/-/evp_bytestokey-1.0.3.tgz#7fcbdb198dc71959432efe13842684e0525acb02"
@@ -1007,6 +1017,11 @@ v8-compile-cache@^2.0.3:
   resolved "https://registry.yarnpkg.com/v8-compile-cache/-/v8-compile-cache-2.3.0.tgz#2de19618c66dc247dcfb6f99338035d8245a2cee"
   integrity sha512-l8lCEmLcLYZh4nbunNZvQCJc5pv7+RCwa8q/LdUx8u7lsWvPDKmpodJAJNwkAhJC//dFY48KuIEmjtd4RViDrA==
 
+webextension-polyfill@^0.8.0:
+  version "0.8.0"
+  resolved "https://registry.yarnpkg.com/webextension-polyfill/-/webextension-polyfill-0.8.0.tgz#f80e9f4b7f81820c420abd6ffbebfa838c60e041"
+  integrity sha512-a19+DzlT6Kp9/UI+mF9XQopeZ+n2ussjhxHJ4/pmIGge9ijCDz7Gn93mNnjpZAk95T4Tae8iHZ6sSf869txqiQ==
+
 websocket-polyfill@^0.0.3:
   version "0.0.3"
   resolved "https://registry.yarnpkg.com/websocket-polyfill/-/websocket-polyfill-0.0.3.tgz#7321ada0f5f17516290ba1cb587ac111b74ce6a5"