Steam Login C # with HttpClient-

I am a beginner, faced with a problem when trying to login to Steam.

public Steam(string password, string login) { Password = password; Login = login; _client.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"); _rsa = new RSACryptoServiceProvider(); _rsaParameters = new RSAParameters(); _params = new Dictionary<string, string>(); } public async Task GetRsa() { var request = await _client.GetAsync($"https://steamcommunity.com/login/getrsakey?username=" + Login); var content = await request.Content.ReadAsStringAsync(); Timestamp = content.Between("timestamp\":\"", "\"", StringComparison.InvariantCulture); TokenGid = content.Between("token_gid\":\"", "\"", StringComparison.InvariantCulture); Mod = content.Between("publickey_mod\":\"", "\"", StringComparison.InvariantCulture); Exp = content.Between("publickey_exp\":\"", "\"", StringComparison.InvariantCulture); _rsaParameters.Modulus = HexToByte(Mod); _rsaParameters.Exponent = HexToByte(Exp); _rsa.ImportParameters(_rsaParameters); var bytePassword = Encoding.ASCII.GetBytes(Password); var encodedPassword = _rsa.Encrypt(bytePassword, false); EncryptedBase64Password = Convert.ToBase64String(encodedPassword); } public async Task TryLogin() { var unixTimestamp = (int)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds; //_params["donotcache"] = unixTimestamp + "000"; _params["username"] = Login; _params["password"] = EncryptedBase64Password; _params["twofactorcode"] = ""; _params["emailauth"] = ""; _params["loginfriendlyname"] = ""; _params["captchagid"] = "-1"; _params["captcha_text"] = ""; _params["emailsteamid"] = ""; _params["rsatimestamp"] = Timestamp; _params["remember_login"] = "false"; var responce2 = await _client.PostAsync($"https://steamcommunity.com/login/dologin/", new FormUrlEncodedContent(_params)); var content2 = await responce2.Content.ReadAsStringAsync(); } 

In response to the request comes:

 {"success":false,"requires_twofactor":false,"message":"The account name or password that you have entered is incorrect.","clear_password_field":true,"captcha_needed":false,"captcha_gid":-1} 

Perhaps there is an error somewhere in RSA encryption, or something is not ok with cookies.