How to match Key & IV generated by C# and JS CryptoJS

Question

I need help to find a way how to match IV and KEY from C# and JS,

with a simple C# code:

Rijndael rijndael = Rijndael.Create();
byte[] saltArray = Encoding.ASCII.GetBytes("20190925");
Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes("password", saltArray, 1000);
rijndael.Key = pdb.GetBytes(32);
rijndael.IV = pdb.GetBytes(16);
Console.WriteLine(BitConverter.ToString(rijndael.Key).Replace("-","").ToLower());
//Output rijndael.Key = c1b34ea814586db4a22dad37e11c7256322ab0eee3a14ed1898f93d7a264242f
Console.WriteLine(BitConverter.ToString(rijndael.IV).Replace("-","").ToLower());
//Output rijndael.IV = 063ead20a9d5f35ab83e1156ebe7c099

with a CryptoJS i can get a same KEY as C# but with the IV i don't get it why the value is not match

CryptoJS code:

let key = CryptoJS.PBKDF2('password', '20190925', {keySize:256/32, iterations:1000})
console.log('key', key.toString(CryptoJS.enc.Hex))
//Output key =  'key', 'c1b34ea814586db4a22dad37e11c7256322ab0eee3a14ed1898f93d7a264242f'
let iv = CryptoJS.PBKDF2('password', '20190925', {keySize:128/32, iterations:1000})
console.log('iv', iv.toString(CryptoJS.enc.Hex))
//Output iv =  'iv', 'c1b34ea814586db4a22dad37e11c7256'

I just think if rijndael.IV = pdb.GetBytes(16); will just get half of rijndael.Key = pdb.GetBytes(32); hex, but the value totally different

is there a way to match IV of C# using CryptoJS?

Answer 1

PBKDF2 must be executed for a length equal to the sum of key length and IV length. The result is divided into two parts. The first part corresponds to the key, the second part to the IV:

let keyLen = 256/32
let ivLen = 128/32
let keyiv = CryptoJS.PBKDF2('password', '20190925', {keySize:keyLen + ivLen, iterations:1000})
let key = CryptoJS.lib.WordArray.create(keyiv.words.slice(0, keyLen));
let iv = CryptoJS.lib.WordArray.create(keyiv.words.slice(keyLen, keyLen + ivLen));
console.log('keyiv:', keyiv.toString())
console.log('key  :', key.toString())
console.log('iv   :', iv.toString())

This results in:

keyiv: c1b34ea814586db4a22dad37e11c7256322ab0eee3a14ed1898f93d7a264242f063ead20a9d5f35ab83e1156ebe7c099
key  : c1b34ea814586db4a22dad37e11c7256322ab0eee3a14ed1898f93d7a264242f
iv   : 063ead20a9d5f35ab83e1156ebe7c099

which matches the result of the C# code.