Использование MD5 для проверки хэша пароля с MySQL

{
                const string myConnectionString = "server=localhost;user id=Launcher;password=SFdksfdsjhfds;persistsecurityinfo=True;database=Test";
                bool auth = false;
                using (MySqlConnection myConnection = new MySqlConnection(myConnectionString))
                {
                    MySqlCommand com = new MySqlCommand("SELECT COUNT(*) FROM _users WHERE name=@login AND password=@password");
                    /* !!! */
                    com.Connection = myConnection;
                    com.Parameters.AddWithValue("@login", LoginTXT.Text);
 
                    com.Parameters.AddWithValue("@password", PassTXT.Text);
                    myConnection.Open();
                    auth = (long)com.ExecuteScalar() == 1;
 
                }
 
                if (auth)
                {
                    APanle.Visible = false;
 
                }
                else
                {
                    Error.Visible = true;
                }
            }

const string myConnectionString = "server=localhost;user id=Launcher;password=SFdksfdsjhfds;persistsecurityinfo=True;database=Test";
 
static void HashPasswords()
{
    using (MySqlConnection myConnection = new MySqlConnection(myConnectionString))
    {
        MySqlCommand selectCmd = new MySqlCommand("SELECT name, password FROM _users", myConnection);
        myConnection.Open();
 
        using (MySqlDataReader dataReader = selectCmd.ExecuteReader())
        {
            while (dataReader.Read())
            {
                string name = (string)dataReader["name"];
                string password = (string)dataReader["password"];
                string passwordHash = PBKDF2HashHelper.CreatePasswordHash(password);
 
                MySqlCommand updateCmd = new MySqlCommand("UPDATE _users SET passwordHash=@passwordHash WHERE name=@name AND password=@password", myConnection);
                updateCmd.Parameters.AddWithValue("@name", name);
                updateCmd.Parameters.AddWithValue("@password", password);
                updateCmd.Parameters.AddWithValue("@passwordHash", passwordHash);
                updateCmd.ExecuteNonQuery();
            }
        }
    }
 
    return PBKDF2HashHelper.VerifyPassword(PassTXT.Text, passwordHash);
}

void buttonLogin_Click(object sender, EventArgs e)
{
    APanle.Visible = ValidateLoginPassword(LoginTXT.Text, PassTXT.Text);
}
 
const string myConnectionString = "server=localhost;user id=Launcher;password=SFdksfdsjhfds;persistsecurityinfo=True;database=Test";
 
static bool ValidateLoginPassword(string login, string password)
{
    if (string.IsNullOrWhitespace(login) || string.IsNullOrWhitespace(password)) return false;
 
    string passwordHash;
    using (MySqlConnection myConnection = new MySqlConnection(myConnectionString))
    {
        MySqlCommand com = new MySqlCommand("SELECT passwordHash FROM _users WHERE name=@login", myConnection);
        com.Parameters.AddWithValue("@login", login);
        myConnection.Open();
        passwordHash = (string)com.ExecuteScalar();
    }
 
    return PBKDF2HashHelper.VerifyPassword(password, passwordHash);
}

return PBKDF2HashHelper.VerifyPassword(password, [B]passwordHash[/B]);