feat: Add dynamic master key by setting Parse Server option masterKey to a function (parse-community#9582)

Author: dblythy

spec/Middlewares.spec.js

@@ -46,32 +46,32 @@ describe('middlewares', () => {
     });
   });
 
-  it('should give invalid response when keys are configured but no key supplied', () => {
+  it('should give invalid response when keys are configured but no key supplied', async () => {
     AppCachePut(fakeReq.body._ApplicationId, {
       masterKey: 'masterKey',
       restAPIKey: 'restAPIKey',
     });
-    middlewares.handleParseHeaders(fakeReq, fakeRes);
+    await middlewares.handleParseHeaders(fakeReq, fakeRes);
     expect(fakeRes.status).toHaveBeenCalledWith(403);
   });
 
-  it('should give invalid response when keys are configured but supplied key is incorrect', () => {
+  it('should give invalid response when keys are configured but supplied key is incorrect', async () => {
     AppCachePut(fakeReq.body._ApplicationId, {
       masterKey: 'masterKey',
       restAPIKey: 'restAPIKey',
     });
     fakeReq.headers['x-parse-rest-api-key'] = 'wrongKey';
-    middlewares.handleParseHeaders(fakeReq, fakeRes);
+    await middlewares.handleParseHeaders(fakeReq, fakeRes);
     expect(fakeRes.status).toHaveBeenCalledWith(403);
   });
 
-  it('should give invalid response when keys are configured but different key is supplied', () => {
+  it('should give invalid response when keys are configured but different key is supplied', async () => {
     AppCachePut(fakeReq.body._ApplicationId, {
       masterKey: 'masterKey',
       restAPIKey: 'restAPIKey',
     });
     fakeReq.headers['x-parse-client-key'] = 'clientKey';
-    middlewares.handleParseHeaders(fakeReq, fakeRes);
+    await middlewares.handleParseHeaders(fakeReq, fakeRes);
     expect(fakeRes.status).toHaveBeenCalledWith(403);
   });
 
@@ -157,13 +157,7 @@ describe('middlewares', () => {
     fakeReq.ip = '127.0.0.1';
     fakeReq.headers['x-parse-master-key'] = 'masterKey';
 
-    let error;
-
-    try {
-      await new Promise(resolve => middlewares.handleParseHeaders(fakeReq, fakeRes, resolve));
-    } catch (err) {
-      error = err;
-    }
+    const error = await middlewares.handleParseHeaders(fakeReq, fakeRes, () => {}).catch(e => e);
 
     expect(error).toBeDefined();
     expect(error.message).toEqual(`unauthorized`);
@@ -182,13 +176,7 @@ describe('middlewares', () => {
     fakeReq.ip = '10.0.0.2';
     fakeReq.headers['x-parse-maintenance-key'] = 'masterKey';
 
-    let error;
-
-    try {
-      await new Promise(resolve => middlewares.handleParseHeaders(fakeReq, fakeRes, resolve));
-    } catch (err) {
-      error = err;
-    }
+    const error = await middlewares.handleParseHeaders(fakeReq, fakeRes, () => {}).catch(e => e);
 
     expect(error).toBeDefined();
     expect(error.message).toEqual(`unauthorized`);

spec/index.spec.js

@@ -601,6 +601,63 @@ describe('server', () => {
     await new Promise(resolve => server.close(resolve));
   });
 
+  it('should load masterKey', async () => {
+    await reconfigureServer({
+      masterKey: () => 'testMasterKey',
+      masterKeyTtl: 1000, // TTL is set
+    });
+
+    await new Parse.Object('TestObject').save();
+
+    const config = Config.get(Parse.applicationId);
+    expect(config.masterKeyCache.masterKey).toEqual('testMasterKey');
+    expect(config.masterKeyCache.expiresAt.getTime()).toBeGreaterThan(Date.now());
+  });
+
+  it('should not reload if ttl is not set', async () => {
+    const masterKeySpy = jasmine.createSpy().and.returnValue(Promise.resolve('initialMasterKey'));
+
+    await reconfigureServer({
+      masterKey: masterKeySpy,
+      masterKeyTtl: null, // No TTL set
+    });
+
+    await new Parse.Object('TestObject').save();
+
+    const config = Config.get(Parse.applicationId);
+    const firstMasterKey = config.masterKeyCache.masterKey;
+
+    // Simulate calling the method again
+    await config.loadMasterKey();
+    const secondMasterKey = config.masterKeyCache.masterKey;
+
+    expect(firstMasterKey).toEqual('initialMasterKey');
+    expect(secondMasterKey).toEqual('initialMasterKey');
+    expect(masterKeySpy).toHaveBeenCalledTimes(1); // Should only be called once
+    expect(config.masterKeyCache.expiresAt).toBeNull(); // TTL is not set, so expiresAt should remain null
+  });
+
+  it('should reload masterKey if ttl is set and expired', async () => {
+    const masterKeySpy = jasmine.createSpy()
+      .and.returnValues(Promise.resolve('firstMasterKey'), Promise.resolve('secondMasterKey'));
+
+    await reconfigureServer({
+      masterKey: masterKeySpy,
+      masterKeyTtl: 1 / 1000, // TTL is set to 1ms
+    });
+
+    await new Parse.Object('TestObject').save();
+
+    await new Promise(resolve => setTimeout(resolve, 10));
+
+    await new Parse.Object('TestObject').save();
+
+    const config = Config.get(Parse.applicationId);
+    expect(masterKeySpy).toHaveBeenCalledTimes(2);
+    expect(config.masterKeyCache.masterKey).toEqual('secondMasterKey');
+  });
+
+
   it('should not fail when Google signin is introduced without the optional clientId', done => {
     const jwt = require('jsonwebtoken');
     const authUtils = require('../lib/Adapters/Auth/utils');

src/Config.js

@@ -724,6 +724,28 @@ export class Config {
     return `${this.publicServerURL}/${this.pagesEndpoint}/${this.applicationId}/verify_email`;
   }
 
+  async loadMasterKey() {
+    if (typeof this.masterKey === 'function') {
+      const ttlIsEmpty = !this.masterKeyTtl;
+      const isExpired = this.masterKeyCache?.expiresAt && this.masterKeyCache.expiresAt < new Date();
+
+      if ((!isExpired || ttlIsEmpty) && this.masterKeyCache?.masterKey) {
+        return this.masterKeyCache.masterKey;
+      }
+
+      const masterKey = await this.masterKey();
+
+      const expiresAt = this.masterKeyTtl ? new Date(Date.now() + 1000 * this.masterKeyTtl) : null
+      this.masterKeyCache = { masterKey, expiresAt };
+      Config.put(this);
+
+      return this.masterKeyCache.masterKey;
+    }
+
+    return this.masterKey;
+  }
+
+
   // TODO: Remove this function once PagesRouter replaces the PublicAPIRouter;
   // the (default) endpoint has to be defined in PagesRouter only.
   get pagesEndpoint() {

src/Options/Definitions.js

@@ -369,6 +369,12 @@ module.exports.ParseServerOptions = {
     action: parsers.arrayParser,
     default: ['127.0.0.1', '::1'],
   },
+  masterKeyTtl: {
+    env: 'PARSE_SERVER_MASTER_KEY_TTL',
+    help:
+      '(Optional) The duration in seconds for which the current `masterKey` is being used before it is requested again if `masterKey` is set to a function. If `masterKey` is not set to a function, this option has no effect. Default is `0`, which means the master key is requested by invoking the  `masterKey` function every time the master key is used internally by Parse Server.',
+    action: parsers.numberParser('masterKeyTtl'),
+  },
   maxLimit: {
     env: 'PARSE_SERVER_MAX_LIMIT',
     help: 'Max value for limit option on queries, defaults to unlimited',

src/Options/docs.js

@@ -46,7 +46,9 @@ export interface ParseServerOptions {
   :ENV: PARSE_SERVER_APPLICATION_ID */
   appId: string;
   /* Your Parse Master Key */
-  masterKey: string;
+  masterKey: (() => void) | string;
+  /* (Optional) The duration in seconds for which the current `masterKey` is being used before it is requested again if `masterKey` is set to a function. If `masterKey` is not set to a function, this option has no effect. Default is `0`, which means the master key is requested by invoking the  `masterKey` function every time the master key is used internally by Parse Server. */
+  masterKeyTtl: ?number;
   /* (Optional) The maintenance key is used for modifying internal and read-only fields of Parse Server.<br><br>⚠️ This key is not intended to be used as part of a regular operation of Parse Server. This key is intended to conduct out-of-band changes such as one-time migrations or data correction tasks. Internal fields are not officially documented and may change at any time without publication in release changelogs. We strongly advice not to rely on internal fields as part of your regular operation and to investigate the implications of any planned changes *directly in the source code* of your current version of Parse Server. */
   maintenanceKey: string;
   /* URL to your parse server with http:// or https://.

src/Options/index.js

@@ -162,7 +162,7 @@ class ParseServer {
       }
       const pushController = await controllers.getPushController(this.config);
       await hooksController.load();
-      const startupPromises = [];
+      const startupPromises = [this.config.loadMasterKey?.()];
       if (schema) {
         startupPromises.push(new DefinedSchemas(schema, this.config).execute());
       }

src/ParseServer.js

@@ -69,7 +69,7 @@ export const checkIp = (ip, ipRangeList, store) => {
 // Adds info to the request:
 // req.config - the Config for this app
 // req.auth - the Auth for this request
-export function handleParseHeaders(req, res, next) {
+export async function handleParseHeaders(req, res, next) {
   var mount = getMountForRequest(req);
 
   let context = {};
@@ -238,7 +238,8 @@ export function handleParseHeaders(req, res, next) {
     );
   }
 
-  let isMaster = info.masterKey === req.config.masterKey;
+  const masterKey = await req.config.loadMasterKey();
+  let isMaster = info.masterKey === masterKey;
 
   if (isMaster && !checkIp(clientIp, req.config.masterKeyIps || [], req.config.masterKeyIpsStore)) {
     const log = req.config?.loggerController || defaultLogger;