Help with generating serial

[raduga_fb]

Actually, "#" and "*" to be removed to create Activation Code.

string pass_1 = "?????";
byte[] pass_1_b = Encoding.ASCII.GetBytes(pass_1);

string pass_2 = "??????";
byte[] pass_2_b = Encoding.ASCII.GetBytes(pass_2);


byte[] hexData = Convert.FromBase64String(Registratin_Code);

byte[] z1 = RC4.Decrypt(pass_1_b, hexData);

byte[] pass_3_b = new byte[16];
Buffer.BlockCopy(z1, 0, pass_3_b, 0, 16);

byte[] z5 = new byte[z1.Length - 16];
Buffer.BlockCopy(z1, 16, z5, 0, z1.Length - 16);

byte[] z3 = RC4.Decrypt(pass_3_b, z5);

string z3_str = BitConverter.ToString(z3).Replace("-", "");

string z4 = Encoding.ASCII.GetString(z3);

//************************************************************

string girdi = z4.Replace("#", "").Replace("*", "");

byte[] girdi_b = Encoding.ASCII.GetBytes(girdi);

byte[] x1 = RC4.Encrypt(pass_3_b, girdi_b);

byte[] x2 = new byte[x1.Length + 16];
Buffer.BlockCopy(pass_3_b, 0, x2, 0, 16);

Buffer.BlockCopy(x1, 0, x2, 16, x1.Length);

byte[] x3 = RC4.Encrypt(pass_2_b, x2);


//************************************************************

string Activation_Code = Convert.ToBase64String(x3);