I generated a base64-encoded key using this code in NodeJS v8.11.0:

const secret = 'shezhuansauce';

const key = crypto.createHash('sha256').update(String(secret)).digest('base64');

//output is REtgV24bDB7xQYoMuypiBASMEaJbc59nJWChoXbbmsA=

Using the key, I try to encrypt a string:

var tobeEncrypted = 'some secret string';

const iv = crypto.randomBytes(16).toString('hex').slice(0, 16);

const cipher = crypto.createCipheriv('aes-256-ctr', key, iv);

const encrypted = cipher.update(String(tobeEncrypted), 'utf8', 'hex') + cipher.final('hex');

console.log(encrypted);

However, I received an error:

crypto.js:219

this._handle.initiv(cipher, toBuf(key), toBuf(iv));

           ^

Error: Invalid key length

The key needs to be base64 string as I will store it in a Cloud service and it only receives base64 string.

Any help is appreciated.