Merge pull request #505 from shocknet/ecc-as-subprocess

Ecc as subprocess

.eslintrc.json

@@ -95,10 +95,7 @@
     "no-warning-comments": "off",
 
     // broken
-    "sort-imports": "off",
-
-    // Would require to needlessly split code into too many files.
-    "mocha/max-top-level-suites": "off"
+    "sort-imports": "off"
   },
   "parser": "babel-eslint",
   "env": {

utils/ECC/ECC.js

@@ -1,6 +1,7 @@
 /** @format */
-const ECCrypto = require('eccrypto')
 const Storage = require('node-persist')
+const { fork } = require('child_process')
+
 const FieldError = require('../fieldError')
 const logger = require('../../config/log')
 const {
@@ -12,6 +13,9 @@ const {
   convertToEncryptedMessage,
   convertBase64ToBuffer
 } = require('./crypto')
+const { invoke } = require('./subprocess')
+
+const cryptoSubprocess = fork('utils/ECC/subprocess')
 
 const nodeKeyPairs = new Map()
 const devicePublicKeys = new Map()
@@ -47,9 +51,9 @@ const isEncryptedMessage = message =>
  * Generates a new encryption key pair that will be used
  * when communicating with the deviceId specified
  * @param {string} deviceId
- * @returns {Pair}
+ * @returns {Promise<Pair>}
  */
-const generateKeyPair = deviceId => {
+const generateKeyPair = async deviceId => {
   try {
     const existingKey = nodeKeyPairs.get(deviceId)
 
@@ -62,8 +66,8 @@ const generateKeyPair = deviceId => {
       }
     }
 
-    const privateKey = ECCrypto.generatePrivate()
-    const publicKey = ECCrypto.getPublic(privateKey)
+    const privateKey = await invoke('generatePrivate', [], cryptoSubprocess)
+    const publicKey = await invoke('getPublic', [privateKey], cryptoSubprocess)
     const privateKeyBase64 = convertBufferToBase64(privateKey)
     const publicKeyBase64 = convertBufferToBase64(publicKey)
 
@@ -107,7 +111,7 @@ const isAuthorizedDevice = ({ deviceId }) => devicePublicKeys.has(deviceId)
 const authorizeDevice = async ({ deviceId, publicKey }) => {
   const hostId = await Storage.get('encryption/hostId')
   devicePublicKeys.set(deviceId, convertBase64ToBuffer(publicKey))
-  const keyPair = generateKeyPair(deviceId)
+  const keyPair = await generateKeyPair(deviceId)
 
   return {
     success: true,
@@ -137,10 +141,12 @@ const encryptMessage = async ({ message = '', deviceId }) => {
 
   const processedPublicKey = processKey(publicKey)
   const messageBuffer = convertUTF8ToBuffer(parsedMessage)
-  const encryptedMessage = await ECCrypto.encrypt(
-    processedPublicKey,
-    messageBuffer
+  const encryptedMessage = await invoke(
+    'encrypt',
+    [processedPublicKey, messageBuffer],
+    cryptoSubprocess
   )
+
   const encryptedMessageResponse = {
     ciphertext: encryptedMessage.ciphertext,
     iv: encryptedMessage.iv,
@@ -173,9 +179,10 @@ const decryptMessage = async ({ encryptedMessage, deviceId }) => {
     }
 
     const processedPrivateKey = processKey(keyPair.privateKey)
-    const decryptedMessage = await ECCrypto.decrypt(
-      processedPrivateKey,
-      convertToEncryptedMessage(encryptedMessage)
+    const decryptedMessage = await invoke(
+      'decrypt',
+      [processedPrivateKey, convertToEncryptedMessage(encryptedMessage)],
+      cryptoSubprocess
     )
     const parsedMessage = decryptedMessage.toString('utf8')
 
@@ -203,5 +210,11 @@ module.exports = {
   authorizeDevice,
   generateRandomString,
   nodeKeyPairs,
-  devicePublicKeys
+  devicePublicKeys,
+  /**
+   * Used for tests.
+   */
+  killECCCryptoSubprocess() {
+    cryptoSubprocess.kill()
+  }
 }

utils/ECC/ECC.spec.js

@@ -12,47 +12,54 @@ const {
   decryptMessage,
   encryptMessage,
   generateKeyPair,
-  isAuthorizedDevice
+  isAuthorizedDevice,
+  killECCCryptoSubprocess
 } = require('./ECC')
 
-const uuid = () => words({ exactly: 24 }).join('-')
+const uuid = () => {
+  const arr = /** @type {string[]} */ (words({ exactly: 24 }))
+  return arr.join('-')
+}
 
 const storageDirectory = Path.resolve(__dirname, `./.test-storage`)
 
 console.log(`Storage directory: ${storageDirectory}`)
 
-describe('generateKeyPair()', () => {
-  it('generates a keypair', () => {
-    const pair = generateKeyPair(uuid())
+describe('ECC', () => {
+  describe('generateKeyPair()', () => {
+    it('generates a keypair', async () => {
+      expect.hasAssertions()
+      const pair = await generateKeyPair(uuid())
 
       expect(pair.privateKey).toBeInstanceOf(Buffer)
       expect(typeof pair.privateKeyBase64 === 'string').toBeTruthy()
       expect(pair.publicKey).toBeInstanceOf(Buffer)
       expect(typeof pair.publicKeyBase64 === 'string').toBeTruthy()
     })
-  it('returns the same pair for the same device', () => {
+    it('returns the same pair for the same device', async () => {
+      expect.hasAssertions()
       const id = uuid()
-    const pair = generateKeyPair(id)
-    const pairAgain = generateKeyPair(id)
+      const pair = await generateKeyPair(id)
+      const pairAgain = await generateKeyPair(id)
 
       expect(pairAgain).toStrictEqual(pair)
     })
-})
+  })
 
-describe('authorizeDevice()/isAuthorizedDevice()', () => {
+  describe('authorizeDevice()/isAuthorizedDevice()', () => {
     it('authorizes a device given its ID', async () => {
       expect.hasAssertions()
       await Storage.init({
         dir: storageDirectory
       })
       const deviceId = uuid()
-    const pair = generateKeyPair(deviceId)
+      const pair = await generateKeyPair(deviceId)
       await authorizeDevice({ deviceId, publicKey: pair.publicKeyBase64 })
       expect(isAuthorizedDevice({ deviceId })).toBeTruthy()
     })
-})
+  })
 
-describe('encryptMessage()/decryptMessage()', () => {
+  describe('encryptMessage()/decryptMessage()', () => {
     before(() =>
       Storage.init({
         dir: storageDirectory
@@ -96,7 +103,7 @@ describe('encryptMessage()/decryptMessage()', () => {
       expect.hasAssertions()
       const deviceId = uuid()
 
-    const pair = generateKeyPair(deviceId)
+      const pair = await generateKeyPair(deviceId)
 
       await authorizeDevice({ deviceId, publicKey: pair.publicKeyBase64 })
 
@@ -111,4 +118,7 @@ describe('encryptMessage()/decryptMessage()', () => {
 
       expect(decrypted).toEqual(message)
     })
+  })
+
+  after(killECCCryptoSubprocess)
 })

utils/ECC/crypto.js

@@ -2,9 +2,14 @@
  * @format
  */
 const { Buffer } = require('buffer')
-const Crypto = require('crypto')
+const { fork } = require('child_process')
+
 const FieldError = require('../fieldError')
 
+const { invoke } = require('./subprocess')
+
+const cryptoSubprocess = fork('utils/ECC/subprocess')
+
 /**
  * @typedef {object} EncryptedMessageBuffer
  * @prop {Buffer} ciphertext
@@ -23,19 +28,15 @@ const FieldError = require('../fieldError')
  * @prop {any?} metadata
  */
 
-const generateRandomString = (length = 16) =>
-  new Promise((resolve, reject) => {
-    // Gotta halve because randomBytes returns a sequence twice the size
-    Crypto.randomBytes(length / 2, (err, buffer) => {
-      if (err) {
-        reject(err)
-        return
+const generateRandomString = async (length = 16) => {
+  if (length % 2 !== 0 || length < 2) {
+    throw new Error('Random string length must be an even number.')
   }
 
-      const token = buffer.toString('hex')
-      resolve(token)
-    })
-  })
+  const res = await invoke('generateRandomString', [length], cryptoSubprocess)
+
+  return res
+}
 
 /**
  * @param {string} value
@@ -135,5 +136,11 @@ module.exports = {
   convertBufferToBase64,
   convertToEncryptedMessage,
   convertToEncryptedMessageResponse,
-  processKey
+  processKey,
+  /**
+   * Used for tests.
+   */
+  killCryptoCryptoSubprocess() {
+    cryptoSubprocess.kill()
+  }
 }

utils/ECC/crypto.spec.js

@@ -7,20 +7,23 @@ const expect = require('expect')
 const {
   generateRandomString,
   convertBase64ToBuffer,
-  convertBufferToBase64
+  convertBufferToBase64,
+  killCryptoCryptoSubprocess
 } = require('./crypto')
 
-describe('generateRandomString()', () => {
+describe('crypto', () => {
+  describe('generateRandomString()', () => {
     it('creates a random string of the specified length', async () => {
       expect.hasAssertions()
-    const len = Math.ceil(Math.random() * 100)
+      const base = Math.ceil(Math.random() * 100)
+      const len = base % 2 !== 0 ? base + 1 : base
       const result = await generateRandomString(len)
 
       expect(result.length).toEqual(len)
     })
-})
+  })
 
-describe('Buffer <> String <> Buffer', () => {
+  describe('Buffer <> String <> Buffer', () => {
     it('preserves values', async () => {
       const rnd = await generateRandomString(24)
 
@@ -30,4 +33,7 @@ describe('Buffer <> String <> Buffer', () => {
 
       expect(asStringAgain).toEqual(rnd)
     })
+  })
+
+  after(killCryptoCryptoSubprocess)
 })

utils/ECC/subprocess.js

@@ -0,0 +1,183 @@
+/**
+ * @format
+ */
+const Crypto = require('crypto')
+const ECCrypto = require('eccrypto')
+const uuid = require('uuid/v1')
+const { Buffer } = require('buffer')
+const mapValues = require('lodash/mapValues')
+
+const logger = require('../../config/log')
+
+logger.info('crypto subprocess invoked')
+
+process.on('uncaughtException', e => {
+  logger.error('Uncaught exception inside crypto subprocess:')
+  logger.error(e)
+})
+
+process.on('unhandledRejection', e => {
+  logger.error('Unhandled rejection inside crypto subprocess:')
+  logger.error(e)
+})
+
+/**
+ * @typedef {'generateRandomString' | 'convertUTF8ToBuffer'
+ * | 'convertBase64ToBuffer' | 'convertBufferToBase64' | 'generatePrivate'
+ * | 'getPublic' | 'encrypt' | 'decrypt'
+ * } Method
+ */
+
+/**
+ * @param {any} obj
+ * @returns {any}
+ */
+const processBufferAfterSerialization = obj => {
+  if (typeof obj === 'object' && obj !== null) {
+    if (obj.type === 'Buffer') {
+      return Buffer.from(obj.data)
+    }
+    return mapValues(obj, processBufferAfterSerialization)
+  }
+  return obj
+}
+
+/**
+ * @typedef {object} Msg
+ * @prop {any[]} args
+ * @prop {string} id
+ * @prop {Method} method
+ */
+
+/**
+ * @param {Msg} msg
+ */
+const handleMsg = async msg => {
+  if (typeof msg !== 'object' || msg === null) {
+    logger.error('Msg in crypto subprocess not an object')
+  }
+
+  const { id, method } = msg
+  const args = msg.args.map(processBufferAfterSerialization)
+
+  try {
+    if (method === 'generateRandomString') {
+      const [length] = args
+
+      Crypto.randomBytes(length / 2, (err, buffer) => {
+        if (err) {
+          // @ts-expect-error
+          process.send({
+            id,
+            err: err.message
+          })
+          return
+        }
+
+        const token = buffer.toString('hex')
+        // @ts-expect-error
+        process.send({
+          id,
+          payload: token
+        })
+      })
+    }
+    if (method === 'convertUTF8ToBuffer') {
+      const [value] = args
+
+      // @ts-expect-error
+      process.send({
+        id,
+        payload: Buffer.from(value, 'utf8')
+      })
+    }
+    if (method === 'convertBase64ToBuffer') {
+      const [value] = args
+
+      // @ts-expect-error
+      process.send({
+        id,
+        payload: Buffer.from(value, 'base64')
+      })
+    }
+    if (method === 'convertBufferToBase64') {
+      const [buffer] = args
+
+      // @ts-expect-error
+      process.send({
+        id,
+        payload: buffer.toString('base64')
+      })
+    }
+    if (method === 'generatePrivate') {
+      // @ts-expect-error
+      process.send({
+        id,
+        payload: ECCrypto.generatePrivate()
+      })
+    }
+    if (method === 'getPublic') {
+      const [privateKey] = args
+      // @ts-expect-error
+      process.send({
+        id,
+        payload: ECCrypto.getPublic(privateKey)
+      })
+    }
+    if (method === 'encrypt') {
+      const [processedPublicKey, messageBuffer] = args
+      // @ts-expect-error
+      process.send({
+        id,
+        payload: await ECCrypto.encrypt(processedPublicKey, messageBuffer)
+      })
+    }
+    if (method === 'decrypt') {
+      const [processedPrivateKey, encryptedMessage] = args
+      // @ts-expect-error
+      process.send({
+        id,
+        payload: await ECCrypto.decrypt(processedPrivateKey, encryptedMessage)
+      })
+    }
+  } catch (e) {
+    // @ts-expect-error
+    process.send({
+      err: e.message
+    })
+  }
+}
+
+process.on('message', handleMsg)
+
+/**
+ * @param {Method} method
+ * @param {any[]} args
+ * @param {import('child_process').ChildProcess} cryptoSubprocess
+ * @returns {Promise<any>}
+ */
+const invoke = (method, args, cryptoSubprocess) =>
+  new Promise((res, rej) => {
+    const id = uuid()
+    /** @param {any} msg */
+    const listener = msg => {
+      if (msg.id === id) {
+        cryptoSubprocess.off('message', listener)
+        if (msg.err) {
+          rej(new Error(msg.err))
+        } else {
+          res(processBufferAfterSerialization(msg.payload))
+        }
+      }
+    }
+    cryptoSubprocess.on('message', listener)
+    cryptoSubprocess.send({
+      args,
+      id,
+      method
+    })
+  })
+
+module.exports = {
+  invoke
+}