fix: Handle OPTIONS (#8)

Dockerfile

@@ -2,7 +2,7 @@ FROM node:16 as base
 WORKDIR /usr/src/spring83
 COPY package*.json ./
 RUN npm install
-COPY common.js .
+COPY common/*.js common/
 COPY *.tmpl.html .
 COPY serve .
 COPY public-boards.json .

common/constants.js

@@ -0,0 +1,43 @@
+const headerNames = {
+  difficulty: 'spring-difficulty',
+  signature: 'spring-signature',
+  version: 'spring-version'
+};
+
+module.exports = {
+  constants: Object.freeze({
+    maximumContentLength: 2217,
+    maximumNumberOfBoards: 10_000_000,
+    protocolVersion: '83',
+    contentType: 'text/html;charset=utf-8',
+    keyMatchRegex: /83e(0[1-9]|1[0-2])(\d\d)$/,
+    unmodifiedSinceTimeFudgeMs: 6000,
+    boardTTLDays: 22,
+    getKeySecurityPolicies: {
+      none: ['default-src', 'script-src', 'script-src-attr', 'script-src-elem',
+        'child-src', 'frame-src', 'prefetch-src', ' object-src'],
+      self: ['font-src'],
+      'unsafe-inline': ['style-src'],
+      'data:': ['img-src']
+    },
+    headerNames,
+    rootTemplateName: 'root.tmpl.html',
+    notFoundTmplName: '404.tmpl.html',
+    testKeyTmplName: 'testkey.tmpl.html',
+    defaultContentPath: '.content',
+    defaultFQDN: 'example.com',
+    strictVerification: true,
+    difficultyFactorExp: 4,
+    ttlCheckFreqMinutes: 11,
+    keypairFilenamePrefix: 'spring-83-keypair',
+    pubBoardsJsonFileName: 'public-boards.json',
+    pubBoardRefreshFreqMinutes: 3,
+    testPublicKey: 'ab589f4dde9fce4180fcf42c7b05185b0a02a5d682e353fa39177995083e0583',
+    corsOptions: {
+      origin: '*',
+      methods: ['GET', 'PUT'],
+      allowedHeaders: ['Content-Type', 'If-Modified-Since', 'Spring-Signature', 'Spring-Version'],
+      exposedHeaders: ['Content-Type', 'Last-Modified', ...Object.values(headerNames)]
+    }
+  })
+};

common/index.js

@@ -0,0 +1,6 @@
+'use strict';
+
+module.exports = {
+  ...require('./constants'),
+  ...require('./utility')
+};

common.js → common/utility.js

@@ -2,40 +2,7 @@
 
 const fs = require('fs');
 const path = require('path');
-
-const constants = Object.freeze({
-  maximumContentLength: 2217,
-  maximumNumberOfBoards: 10_000_000,
-  protocolVersion: '83',
-  contentType: 'text/html;charset=utf-8',
-  keyMatchRegex: /83e(0[1-9]|1[0-2])(\d\d)$/,
-  unmodifiedSinceTimeFudgeMs: 6000,
-  boardTTLDays: 22,
-  getKeySecurityPolicies: {
-    none: ['default-src', 'script-src', 'script-src-attr', 'script-src-elem',
-      'child-src', 'frame-src', 'prefetch-src', ' object-src'],
-    self: ['font-src'],
-    'unsafe-inline': ['style-src'],
-    'data:': ['img-src']
-  },
-  headerNames: {
-    difficulty: 'spring-difficulty',
-    signature: 'spring-signature',
-    version: 'spring-version'
-  },
-  rootTemplateName: 'root.tmpl.html',
-  notFoundTmplName: '404.tmpl.html',
-  testKeyTmplName: 'testkey.tmpl.html',
-  defaultContentPath: '.content',
-  defaultFQDN: 'example.com',
-  strictVerification: true,
-  difficultyFactorExp: 4,
-  ttlCheckFreqMinutes: 11,
-  keypairFilenamePrefix: 'spring-83-keypair',
-  pubBoardsJsonFileName: 'public-boards.json',
-  pubBoardRefreshFreqMinutes: 3,
-  testPublicKey: 'ab589f4dde9fce4180fcf42c7b05185b0a02a5d682e353fa39177995083e0583'
-});
+const { constants } = require('./constants');
 
 function keyPairFilename (publicKey, root = __dirname) {
   if (typeof publicKey !== 'string') {
@@ -136,7 +103,6 @@ function keyIsUnderDifficultyThreshold (pubKey, knownKeys) {
 }
 
 module.exports = {
-  constants,
   pubKeyIsValid: (pubKeyData, strict = false) => pubKeyHexIsValid(Buffer.from(pubKeyData).toString('hex'), strict),
   pubKeyHexIsValid,
   getCurrentDifficultyFactor,

package.json

@@ -4,12 +4,13 @@
   "description": "An implementation of the Spring 83 protocol 🌸",
   "main": "serve",
   "scripts": {
-    "lint": "semistandard --fix --verbose findkey putnew serve *.js test/*.js",
+    "lint": "semistandard --fix --verbose findkey putnew serve common/*.js test/*.js",
     "test": "tape test/*.js"
   },
   "author": "",
   "license": "ISC",
   "dependencies": {
+    "@fastify/cors": "^8.0.0",
     "@noble/ed25519": "^1.6.0",
     "cheerio": "^1.0.0-rc.11",
     "fastify": "^4.0.1",

serve

@@ -7,7 +7,6 @@ const path = require('path');
 const cheerio = require('cheerio');
 const ed = require('@noble/ed25519');
 const mustache = require('mustache');
-const app = require('fastify')({ logger: true });
 const {
   constants,
   findKnownKeys,
@@ -17,6 +16,9 @@ const {
   boardExistsLocally
 } = require('./common');
 
+const app = require('fastify')({ logger: true });
+app.register(require('@fastify/cors'), constants.corsOptions);
+
 const expectPutHeaders = Object.freeze({
   'content-type': constants.contentType,
   [constants.headerNames.version]: constants.protocolVersion,