HttpWebRequest response produces HTTP 422. Why?
- by Simon
Hi there.
I'm trying to programmatically send a POST-request to a web-server in order to login an then perform other requests that require a login.
This is my code:
Encoding.UTF8.GetBytes(
String.Format(
"login={0}&password={1}&authenticity_token={2}",
username, password, token));
//Create HTTP-request for login
HttpWebRequest request =
(HttpWebRequest)HttpWebRequest.Create("http://www.xxx.xx/xx/xx");
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
request.CookieContainer = new CookieContainer();
request.Accept = "application/xml,application/xhtml+xml,text/html;
+"q=0.9,text/plain ;q=0.8,image/png,*/*;q=0.5";
request.Referer = "http://www.garzantilinguistica.it/it/session";
request.Headers.Add("Accept-Language", "de-DE");
request.Headers.Add("Origin", "http://www.xxx.xx");
request.UserAgent = "C#";
request.Headers.Add("Accept-Encoding", "gzip, deflate");
After sending the request
//Send post request
var requestStream = request.GetRequestStream();
requestStream.Write(data, 0, data.Length);
requestStream.Flush();
requestStream.Close();
... I want to get the servers response:
//Get Response
StreamReader responseStreamReader = new
StreamReader(
request.GetResponse().GetResponseStream()); //WebException: HTTP 422!
string content = responseStreamReader.ReadToEnd();
This piece of code fires the WebException, that tells me the server responded with HTTP 422 (unprocessable entity due to semantic errors)
Then I compared (using a TCP/IP sniffers) the requests of my program and the browser (which of course produces a valid POST-request and gets the right response).
(1) My program's request:
POST /it/session HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Accept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;
q=0.8,image/png,*/*;q=0.5
Referer: http://www.garzantilinguistica.it/it/session
Accept-Language: de-DE
Origin: http://www.garzantilinguistica.it
User-Agent: C#
Accept-Encoding: gzip, deflate
Host: www.garzantilinguistica.it
Content-Length: 111
Expect: 100-continue
Connection: Keep-Alive
HTTP/1.1 100 Continue
[email protected]&password=machivui&authenticity_token=4vLgtwP3nFNg4NeuG4MbUnU7sy4z91Wi8WJXH0POFmg=
HTTP/1.1 422 Unprocessable Entity
(2) The browser's request:
POST /it/session HTTP/1.1
Host: www.garzantilinguistica.it
Referer: http://www.garzantilinguistica.it/it/session
Accept: application/xml,application/xhtml+xml,text/html;q=0.9,
text/plain;q=0.8,image/png,*/*;q=0.5
Accept-Language: de-DE
Origin: http://www.garzantilinguistica.it
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de-DE) AppleWebKit/531.22.7 (KHTML, like Gecko) Version/4.0.5 Safari/531.22.7
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Cookie: __utma=244184339.652523587.1275208707.1275208707.1275211298.2; __utmb=244184339.20.10.1275211298; __utmc=244184339; __utmz=244184339.1275208707.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); _garzanti2009_session=BAh7CDoPc2Vzc2lvbl9pZCIlZDg4MWZjNjg2YTRhZWE0NDQ0ZTJmMTU2YWY4ZTQ1NGU6EF9jc3JmX3Rva2VuIjFqRWdLdll3dTYwOTVVTEpNZkt6dG9jUCtaZ0o4V0FnV2V5ZnpuREx6QUlZPSIKZmxhc2hJQzonQWN0aW9uQ29udHJvbGxlcjo6Rmxhc2g6OkZsYXNoSGFzaHsGOgplcnJvciIVbG9naW4gbm9uIHZhbGlkbwY6CkB1c2VkewY7CFQ%3D--4200fa769898dd156faa49e457baf660cf068d08
Content-Length: 144
Connection: keep-alive
authenticity_token=jEgKvYwu6095ULJMfKztocP%2BZgJ8WAgWeyfznDLzAIY%3D&login=thespider14%40hotmail.com&password=machivui&remember_me=1&commit=Entra
HTTP/1.1 302 Found
Can someone help to understand which part of the request I am missing or what the main
difference between the browser's and my request is? Why am I getting that 422?
