Submit a form on external domain (C# or Javascript)

Question

I need a way to automatically fill and submit a form.It has to go from a URL, because i need to call that from my domoticz. I tried submitting with AJAX and injecting javascript, but i get the Same-origin policy. The form i try to submit isn't mine, so i can't make changes on that side.

i tried:

JQUERY

setTimeout(function(){ $("#frame").attr("src", ":javascript:alert('test');"); }, 3000);

C#

frame.Src = "https://URL"; int milliseconds = 10000; Thread.Sleep(milliseconds); frame.Src = "javascript:alert('test');";

C# 2

`

    WebRequest req = WebRequest.Create("URL");
    string postData = "field1=11111&field2=22222&field3=33333";
    byte[] send = Encoding.Default.GetBytes(postData);
    req.Method = "POST";
    req.ContentType = "application/x-www-form-urlencoded";
    req.ContentLength = send.Length;
    Stream sout = req.GetRequestStream();
    sout.Write(send, 0, send.Length);
    sout.Flush();`

Why do i want to use this? With the form you check in your car for an hour. After an hour you have to check it in again. All day long something i forgot all the time.

Answer 1

I propose you to use the following class:

public static class WebRequester
{
    /// <summary>
    /// Sending POST request.
    /// </summary>
    /// <param name="url">Request Url.</param>
    /// <param name="data">Data for request.</param>
    /// <param name="userName">user name for log in</param>
    /// <param name="password">password for log in</param>
    /// <returns>Response body.</returns>
    public static string HttpPost(string url, string data, string userName = "", string password = "", int timeout = 100000)
    {

        string Out = String.Empty;
        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
        try
        {
            req.ContentType = "application/json";
            req.Method = "POST";
            req.ProtocolVersion = HttpVersion.Version11;
            req.Accept = "*/*";

            AddAuthentication(userName, password, req);

            req.Timeout = timeout;
            //req.ContentType = "application/x-www-form-urlencoded";
            byte[] sentData = Encoding.UTF8.GetBytes(data);
            req.ContentLength = sentData.Length;
            using (System.IO.Stream sendStream = req.GetRequestStream())
            {
                sendStream.Write(sentData, 0, sentData.Length);
                sendStream.Flush();
                sendStream.Close();
            }
            HttpWebResponse res = (HttpWebResponse)req.GetResponse();
            System.IO.Stream ReceiveStream = res.GetResponseStream();
            using (System.IO.StreamReader sr = new System.IO.StreamReader(ReceiveStream, Encoding.UTF8))
            {
                Char[] read = new Char[256];
                int count = sr.Read(read, 0, 256);

                while (count > 0)
                {
                    String str = new String(read, 0, count);
                    Out += str;
                    count = sr.Read(read, 0, 256);
                }
            }
        }
        catch (ArgumentException ex)
        {
            Out = string.Format("HTTP_ERROR :: The second HttpWebRequest object has raised an Argument Exception as 'Connection' Property is set to 'Close' :: {0}", ex.Message);
        }
        catch (WebException ex)
        {
            Out = string.Format("HTTP_ERROR :: WebException raised! :: {0}", ex.Message);
        }
        catch (Exception ex)
        {
            Out = string.Format("HTTP_ERROR :: Exception raised! :: {0}", ex.Message);
        }

        return Out;
    }

    /// <summary>
    /// Sending GET request.
    /// </summary>
    /// <param name="url">Request Url.</param>
    /// <param name="data">Data for request.</param>
    /// <param name="userName">user name for log in</param>
    /// <param name="password">password for log in</param>
    /// <returns>Response body.</returns>
    public static string HttpGet(string url, string data, string userName, string password)
    {
        string Out = String.Empty;
        Uri uri = new Uri(url);

        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url + (string.IsNullOrEmpty(data) ? "" : "?" + data));
        req.ContentType = "application/json";
        req.Method = "GET";

        AddAuthentication(userName, password, req);
        try
        {
            System.Net.WebResponse resp = req.GetResponse();
            using (System.IO.Stream stream = resp.GetResponseStream())
            {
                using (System.IO.StreamReader sr = new System.IO.StreamReader(stream))
                {
                    Out = sr.ReadToEnd();
                    sr.Close();
                }
            }
        }
        catch (ArgumentException ex)
        {
            Out = string.Format("HTTP_ERROR :: The second HttpWebRequest object has raised an Argument Exception as 'Connection' Property is set to 'Close' :: {0}", ex.Message);
        }
        catch (WebException ex)
        {
            Out = string.Format("HTTP_ERROR :: WebException raised! :: {0}", ex.Message);
        }
        catch (Exception ex)
        {
            Out = string.Format("HTTP_ERROR :: Exception raised! :: {0}", ex.Message);
        }

        return Out;
    }

    private static void AddAuthentication(string userName, string password, HttpWebRequest req)
    {
        if (userName != null && password != null)
        {
            string base64Credentials = GetEncodedCredentials(userName, password);
            req.Headers.Add("Authorization", "Basic " + base64Credentials);
        }
    }

    /// <summary>
    /// Sending Delete request.
    /// </summary>
    /// <param name="url">Request Url.</param>
    /// <param name="data">Data for delete.</param>
    /// <param name="userName">user name for log in</param>
    /// <param name="password">password for log in</param>
    /// <returns>Response body.</returns>
    public static string HttpDelete(string url, string data, string userName, string password)
    {
        string Out = String.Empty;
        Uri uri = new Uri(url);

        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url + (string.IsNullOrEmpty(data) ? "" : "?" + data));
        req.ContentType = "application/json";
        req.Method = "DELETE";

        AddAuthentication(userName, password, req);

        try
        {
            System.Net.WebResponse resp = req.GetResponse();
            using (System.IO.Stream stream = resp.GetResponseStream())
            {
                using (System.IO.StreamReader sr = new System.IO.StreamReader(stream))
                {
                    Out = sr.ReadToEnd();
                    sr.Close();
                }
            }
        }
        catch (ArgumentException ex)
        {
            Out = string.Format("HTTP_ERROR :: The second HttpWebRequest object has raised an Argument Exception as 'Connection' Property is set to 'Close' :: {0}", ex.Message);
        }
        catch (WebException ex)
        {
            Out = string.Format("HTTP_ERROR :: WebException raised! :: {0}", ex.Message);
        }
        catch (Exception ex)
        {
            Out = string.Format("HTTP_ERROR :: Exception raised! :: {0}", ex.Message);
        }

        return Out;
    }

    private static string GetEncodedCredentials(string userName, string password)
    {
        string mergedCredentials = string.Format("{0}:{1}", userName, password);
        byte[] byteCredentials = UTF8Encoding.UTF8.GetBytes(mergedCredentials);
        return Convert.ToBase64String(byteCredentials);
    }
}

you can use it in the following way for posting data to web server:

var result = WebRequester.HttpPost(url, jsonData, userName, password);

result will contain answer from server.