HttpWebRequest causes Response does not start with HTTP.Data

Question

I am trying to use craigslist bulk posting by doing the following:

HttpWebRequest request = null;
Uri uri = new Uri("https://post.craigslist.org/bulk-rss/post");
request = (HttpWebRequest)WebRequest.Create(uri);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = FormattedXmlDocument.InnerXml.Length;
using (Stream writeStream = request.GetRequestStream())
{
    UTF8Encoding encoding = new UTF8Encoding();
    byte[] bytes = encoding.GetBytes(FormattedXmlDocument.InnerXml);
    writeStream.Write(bytes, 0, bytes.Length);
}
string result = string.Empty;

request.ProtocolVersion = System.Net.HttpVersion.Version11;
request.KeepAlive = false;
try
{
    using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
    {
        using (Stream responseStream = response.GetResponseStream())
        {
            using (System.IO.StreamReader readStream = new System.IO.StreamReader(responseStream, Encoding.UTF8))
            {
                result = readStream.ReadToEnd();
            }
        }
    }
}
catch (Exception exp)
{
    // MessageBox.Show(exp.Message);
}

When the this line of code is performed

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())

I get the exception:

The remote server returned an error: (500) Internal Server Error.

I used fiddler to check the request and it get the following error there:

Response does not start with HTTP.Data:

and the pacakage looks like this:

POST https://post.craigslist.org/bulk-rss/post HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: post.craigslist.org
Content-Length: 739
Expect: 100-continue
Connection: Keep-Alive

<rdf:RDF xmlns="http://purl.org/rss/1.0/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:cl="http://www.craigslist.org/about/cl-bulk-ns/1.0"><channel><items><rdf:li rdf:resource="TestJobPost1" /></items><cl:auth username="[email protected]" password="2749saturn" accountID="14" /></channel><item rdf:about="TestJobPost1"><cl:category>sof</cl:category><cl:area>nyc</cl:area><cl:subarea>stn</cl:subarea><cl:neighborhood>Grasmere</cl:neighborhood><cl:jobInfo compensation="100000.00" telecommuting="0" partTime="0" contract="0" nonprofit="0" internship="0" disability="0" recruitersOK="0" phoneCallsOK="0" okToContact="0" okToRepost="0" /><title>First Position</title><description><![CDATA[teset]]></description></item></rdf:RDF>

Any help would be much appreciated.

Answer 1

Writing to request.GetRequestStream() will start sending data to the server.

Setting request properties after that will break the protocol.