public static (byte[] pw, byte[] mk, byte[] ak, string reqpw) CreateAuthData003(StandardNoteAPI.APIResultAuthParams apiparams, string mail, string uip)
{
if (apiparams.pw_cost < 100000)
{
throw new StandardNoteAPIException($"Account pw_cost is too small ({apiparams.pw_cost})");
}
var salt = StandardNoteCrypt.SHA256Hex(string.Join(":", mail, "SF", "003", apiparams.pw_cost.ToString(), apiparams.pw_nonce));
byte[] bytes = PBKDF2.GenerateDerivedKey(768 / 8, Encoding.UTF8.GetBytes(uip), Encoding.UTF8.GetBytes(salt), apiparams.pw_cost, PBKDF2.HMACType.SHA512);
var pw = bytes.Skip(0 * (bytes.Length / 3)).Take(bytes.Length / 3).ToArray();
var mk = bytes.Skip(1 * (bytes.Length / 3)).Take(bytes.Length / 3).ToArray();
var ak = bytes.Skip(2 * (bytes.Length / 3)).Take(bytes.Length / 3).ToArray();
var reqpw = EncodingConverter.ByteToHexBitFiddleUppercase(pw).ToLower();
return(pw, mk, ak, reqpw);
}
