private static bool Authenticate(NntpClient client, string username, string password) { // try to authenticate with username and password from options if (!string.IsNullOrWhiteSpace(username) && !string.IsNullOrWhiteSpace(password) && client.Authenticate(username, password)) { return true; } // get password and username if not provided in options for (var tries = 3; tries > 0; tries--) { // get username string defaultUsername = string.IsNullOrWhiteSpace(username) ? null : $"[default = {username}]"; Console.Write($"Username{defaultUsername}: "); string userName = Console.ReadLine(); if (!string.IsNullOrWhiteSpace(userName)) { username = userName; } if (string.IsNullOrWhiteSpace(username)) { return false; } // get password Console.Write("Password: "******"Invalid credentials."); } return false; }