Basic Node.js crypto cipher/decipher example.

encrypt-decrypt.js

var crypto = require('crypto')
  , key = 'salt_from_the_user_document'
  , plaintext = 'password'
  , cipher = crypto.createCipher('aes-256-cbc', key)
  , decipher = crypto.createDecipher('aes-256-cbc', key);
  
cipher.update(plaintext, 'utf8', 'base64');
var encryptedPassword = cipher.final('base64')

decipher.update(encryptedPassword, 'base64', 'utf8');
var decryptedPassword = decipher.final('utf8');

console.log('encrypted :', encryptedPassword);
console.log('decrypted :', decryptedPassword);

I would not copy this code if I were you. CBC mode requires an IV (Initialization Vector) to initialize the first block of plaintext. This example is extremely broken and insecure. Look for an example that uses an IV and make sure that IV is unique for each time you encrypt something.

http://www.levigross.com/2014/03/30/how-to-write-an-encrypt-and-decrypt-api-for-data-at-rest-in-nodejs/

TypeError: error:0606506D:digital envelope routines:EVP_DecryptFinal_ex:wrong final block length

Note: This error appears when the Decrypt function receives other string different to the encrypted string 😄 👊
Source: It just occurred to me

@dkhonig Agree.