Use a constant for the algorithm

Author: simonratner

lib/encrypted-attr.js

@@ -1,15 +1,18 @@
 'use strict'
 
+const alg = 'aes-256-gcm'
 const crypto = require('crypto')
 const { get, set } = require('lodash')
 
 function EncryptedAttributes (attributes, options) {
   options = options || {}
 
+  let prefix = Buffer.from(`${alg}$`).toString('base64')
+
   function encryptAttribute (obj, val) {
     // Encrypted attributes are prefixed with "aes-256-gcm$", the base64
-    // encoding of which is "YWVzLTI1Ni1nY20k". Nulls are not encrypted.
-    if (val == null || (typeof val === 'string' && val.startsWith('YWVzLTI1Ni1nY20k'))) {
+    // encoding of which is in `prefix`. Nulls are not encrypted.
+    if (val == null || (typeof val === 'string' && val.startsWith(prefix))) {
       return val
     }
     if (typeof val !== 'string') {
@@ -44,8 +47,8 @@ function EncryptedAttributes (attributes, options) {
 
   function decryptAttribute (obj, val) {
     // Encrypted attributes are prefixed with "aes-256-gcm$", the base64
-    // encoding of which is "YWVzLTI1Ni1nY20k". Nulls are not encrypted.
-    if (typeof val !== 'string' || !val.startsWith('YWVzLTI1Ni1nY20k')) {
+    // encoding of which is in `prefix`. Nulls are not encrypted.
+    if (typeof val !== 'string' || !val.startsWith(prefix)) {
       return val
     }
     if (options.verifyId && !obj.id) {