crypto.pbkdf2 fails silently with NaN bitlength

[coolaj86]

Here's an example:

 'use strict';

 function sha256(buf) {
 return crypto.createHash('sha256').update(buf).digest('hex');
 }

 var crypto = require('crypto');
 var secret = 'my special secret';
 var appPbkdf2Salt = sha256(new Buffer("MY_SALT"));
 var iterations = 1000;
 var bitLength; // oops, forgot to define bit length
 var keyByteLength = bitLength / 8;
 var hashname = 'sha256';

 crypto.pbkdf2(secret, appPbkdf2Salt, iterations, keyByteLength, hashname, function (err, bytes) {
 if (err) {
 throw err;
 }

 console.log('bytes', bytes.toString('hex'));
 });

I'm assuming that NaN is coerced to 0. I would think that 0 should also throw an error.

[coolaj86]

Thank you @johannhof, @brendanashworth!